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BIOLOGY 3201 CURRICULUM GUIDE 105

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STSE

Science-Technology-Society and the Environment

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106 BIOLOGY 3201 CURRICULUM GUIDE

Important Note

These STSE modules are intended for teacherreference. Each is designed to target specificoutcomes within Biology 3201.

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Outcomes:1. Explain how the nervous system helps maintain homeostasis. (317-1)

2. Describe disorders linked to the nervous system and their effect on the homeostasis of the systemand the organism as a whole. (317-4)

3. Analyse how and why technologies related to the treatment of nervous system disorders weredeveloped and improved over time. (115-5)

4. Describe how the use of prescription and nonprescription drugs can have a role in maintaining ordisrupting homeostasis. (317-7)

5. Distinguish between questions that can be answered by science and those that cannot, andbetween problems that can be solved by technology and those that cannot. (118-8)

- Debate the merits of using drugs for treatments of nervous disorders against the long-termside effects.

6 Propose courses of action on social issues related to science and technology, taking into an array ofperspectives, including that of sustainability. (118-10)

- Debate the legalization of certain drugs such as marijuana for medicinal purposes.

Drugs and Homeostasis

Introduction

Drugs have been considered invaluable to society asan instrument in the treatment of disease. Insulin isa hormone used to control diabetes. Chemotherapyuses drugs to destroy cancer cells. The use ofpainkillers such as Tylenol and antibiotics areprevalent in society. Prozac is a well-known drugused in the treatment of depression. Drugs have alsobeen considered a danger to society in because oftheir inappropriate use and addictive nature. Manyhigh profile actors have admitted to drug andalcohol abuse such as Ben Affleck, Wimona Riderand Robert Downey Jr. and have soughtrehabilitation for their addictions. This module willexamine the medical use of drugs in the treatment ofdisease, as well as, their abuse in society. It will alsoexamine the long-term affects of drugs on the healthof the human body.

Neurotransmitters and the Nervous

Response

Many drugs affect neurotransmitters.Neurotransmitters are chemicals secreted by neuronswhich stimulate motor neurons or neurons of thecentral nervous system. If you recall, a wave ofdepolarization is carried across a presynaptic neuronuntil it reaches the bulb-like ends of the axon. Theend of the axon contains the neurotransmitter in itsvesicles. Depolarization causes the calcium gates toopen and trigger the release of the neurotransmitterthrough exocytosis. The neurotransmitter diffusesbetween the synapse of the terminal end of the axonof the presynaptic neuron and the dendrites of thepostsynaptic neuron. The dendrites of thepostsynaptic neuron have specialized receptor sites towhich the neurotransmitter will attach. Theneurotransmitter will then either excite or inhibit theneuron. Once a neurotransmitter has attached tothe receptor site of the postsynaptic neuron, anenzyme is released from the presynaptic neuron tobreak down the neurotransmitter.

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Some neurotransmitters are excitory and includeacetylcholine, norepinephrine (noradrenaline),serotonin and dopamine. Other neurotransmittersare associated with relaxation such as dopamine andserotonin. Many neurotransmitters can havemultiple functions.

The drugs abused in society are typically stimulantsor depressants thought to block or enhance certainneurotransmitters. Diseases of the nervous systemare often associated with the improper functioningof a neurotransmitter or improper functioning of theenzyme used to break them down once they havebeen released and attached to the receptor site of thepostsynaptic neuron. Drugs can be developed tomimic the effects of the affected neurotransmitter orenzyme to treat these diseases.

Drugs in the Treatment of Disease

As just discussed, imbalances in neurotransmitterscan contribute to certain diseases. Several wellknown examples are Parkinson’s disease andHuntington’s disease. Parkinson’s disease is believedto be caused by a dopamine deficiency due to thegradual death of the neurons that producedopamine. A dopamine deficiency can result intremors and rigidity in the limbs since messages cannot be sent between areas of the brain controllingbody movement.

Huntington’s disease is believed to be caused by amalfunctioning of an inhibitory neurotransmitter. Huntington’s is a genetic disorder characterized by jerkymovements and loss of mental and emotional abilities dueto the destruction of neurons in certain areas of the brain.

Potential treatment is aimed at replacing the damagedneurons in both of these cases through the experimentaluse of stem cell transplants. At present, other treatmentsinvolve targeting the defective neurotransmitters such asincreasing dopamine levels in Parkinson’s patients.

More and more research has shown that mentalillness is also a result of imbalances ofneurotransmitters. Mental illnesses were onceconsidered to have no biological basis but rather bedue to factors in an individual’s environment such asexperiencing stress or forms of mental and physicalabuse. At one time, sufferers of mental illness were

deemed as “weak minded” and lacking the skills tocope with life.

As science has progressed, genetic connections weremade with individuals in the same family sufferingfrom mental illness. This lead to the exploration ofa biological basis for mental disorders and resulted ina greater understanding by society regarding thecauses of mental illness. Mental illness has nowbecome discussed more openly in society andappreciated as a medical condition.

Debate still continues regarding the issue of natureversus nurture in the onset of mental illness but allmust agree that the biological basis of mentaldisorders exists. The effective treatment of mentaldisorders with drugs also adds support to thebiological basis of these disorders. This next sectionwill explore the biological basis of certain mentalillnesses and the use of drugs in their treatment.

Clinical Depression Clinical depression is the most frequentlyencountered mental illness. Clinical depression isnow considered a physical condition in which thereis a fault in the brain chemistry. It may afflict up to5% or more of the population. Symptoms ofdepression include a distinct change in moodaccompanied with an extreme feeling ofhopelessness. Other symptoms include: loss ofappetite; weight loss; headaches; sleeplessness; loss ofenergy; and tiredness. Symptoms of anxiety are alsoquite common. Suicide is common in about 15% ofdepressed patients.

Serotonin, dopamine, and noradrenaline areneurotransmitters linked to clinical depression. Those suffering from depression either secrete toolittle of a particular neurotransmitter or too much ofthe neurotransmitter is broken down by enzymes(monoamine oxidases) when it is reabsorbed intonerve endings.

Three major classes of drugs are used in thetreatment of depression. They are monoamineoxidase inhibitors (MAOI’s) , selective serotonin re-uptake inhibitors (SSRI’s), and tricyclic compounds. Drug treatment is difficult because some drugs mayhave no effect and the patient may spend a period oftime searching for the proper drug and dosage that

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may help to alleviate the depression. It also takesseveral weeks for the drugs to take effect, if they areto work. In this time period, the patient could gointo remission or the condition may worsen. Theresult can be unrelated to the drug. These factorsmay make the treatment with drugs difficult and theprocess of finding a successful drug very lengthy. Itis unknown why the effect of drugs take such alength of time. It is also unknown why some drugtreatments are successful and others are not. Moreresearch into the causes of depression is needed inorder to obtain more successful treatment.

Tricyclic inhibitors appear to slow the re-uptake ofserotonin and noradrenaline. MAOI’s are believedto inhibit monoamine oxidase (MAO). MAO is anenzyme that is believed to break down serotonin andnoradrenaline. It has been shown that enhancementof these neurotransmitter systems leads to theelevation of mood. A danger of MAOI’s and tricycliccompounds is the increased risk of heart failure. MAO inhibitors can not be taken with certain foodssuch as cheese, avocado, and wine because thisinteraction will raise blood pressure that can causeheart failure and death. Usually, doctors will avoidprescribing MAOI’s for these reasons. These drugscan also be lethal at relatively low dosages which is aconcern for suicidal patients. Serotonin re-uptake inhibitors are the most widelyprescribed antidepressant. It appears to have fewerdangerous side-effects. A well known example isProzac. It functions by blocking serotonin uptakeand therefore increasing the levels of serotonin at thesynapse. Side effects include nausea, headache,insomnia and anxiety.

Bipolar DisorderBipolar disorder is also known as manic depression. Itaffects about 5 in 1000 people. It is characterized bysevere mood swings ranging from mania todepression, with normal periods in between. Duringa manic phase, the individual may think that theyare invincible, behave recklessly or believe indelusions such as ones of fame. During thedepressive phase, the individual loses interest in theirusual activities, may sleep excessively or suffer frominsomnia. They may also be at risk of suicide duringthe depressive stage.

At one time, sufferers from manic depression wereunable to function in life normally. Fortunately,manic depression can now be treated with bothmedication and psychotherapy. The most commonmedication is lithium carbonate. It functions bymaintaining the chemical balances in the brain toprevent mood swings. Lithium appears to work inthe treatment of both mania and depression. This isbecause it is believed that the depressive phase is aresult of the preceding manic phase. If the manicphase can be controlled, then the depressive phasecan be controlled indirectly. Other drugs may beused to treat the symptoms of depression.

Unfortunately, the long term use of lithium canaffect the kidney and thyroid gland since lithiuminterferes with water and salt balance. There must beregular check ups to ensure that the lithium levels donot rise to a toxic level. Other side-effects of lithiumtreatment include: diarrhea; nausea; hand tremor;blurred vision; confusion; and swelling in the legsand feet. The side effects of this medication are whysome manic depressives are reluctant to continue useof lithium. Researchers and drug companies areworking to find better medications with less side-effects. In the meantime, patients are left with thedilemma of taking a medication that provides thebenefit of treating their mental disorder but can alsocreate grave concerns over some of its very seriousside-effects.The causes of manic depression are still uncertain. There appears to be a genetic link and episodes canalso be triggered by stress. Chemical changes arealso being studied. Manic behaviour is believed dueto a high level of noradrenergic activity. Thisactivity continues until the neurotransmitter systemsare depleted. It is believed that lithium may preventmania by preventing noradrenaline depletion.

SchizophreniaA greater understanding in society of schizophreniaas a mental illness was created by the award winningmovie, A Beautiful Mind. The movie focuses on thelife of John Forbes Nash Jr. and his struggle to copewith his mental illness. Nash was a mathematicalgenius who later received a Nobel Prize inEconomics. Actor, Russell Crowe, plays Nash andportrays the symptoms of the disorder, as well asNash’s struggle. The primary symptoms ofschizophrenia include disturbance of thought

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patterns, disturbance of affective reactions andautism or withdrawal. Secondary symptoms includehallucinations, delusions and paranoia. Thesesymptoms all represent a loss of contact with reality.This disorder appears at a rate of 1 to 2 percent inthe population.

There is a biological basis that predisposesindividuals to the development of schizophrenia. Aform of dopamine dysfunction, such as excessivedopamine activity, is believed to causeschizophrenia. Schizophrenic patients seem to havean excess number of dopamine receptors.

Chlorpromazine and related drugs have been used inthe treatment of schizophrenia and functions inblocking the dopamine receptors. Unfortunately,the side effects are similar to Parkinson’s disease. Other side-effects include abnormal body and facemovements and extreme pacing. If this occurs, eitherthe dosage is adjusted or a new medication isprescribed. Other side-effects include dry mouth,constipation, blurred vision and low blood pressure. Unfortunately, patients with schizophrenia are facedwith a similar dilemma as those with bipolardisorder. They must rely on a drug to treat theirdisorder and enable normal functioning in life thathas difficult side-effects.

Commonly Abused Drugs

AlcoholAlcohol is probably the most commonly abused drugin society. Of all abused drugs, it is presently theonly one considered legal upon reaching of age. Ithas been a large part of our culture for many yearsand is often associated with social functions andcelebrations. However, alcohol use definitely has itsdark side. It is known to alter personalities andcause people to behave in manner outside theirnormal personalities. A night of abusing alcohol canlead embarrassment and regret once the effects haveworn off. Poor judgment while drinking alcohol canlead to making deadly decisions such as drunkdriving. Also, people have abused alcohol to theextent they vomit in their sleep and choke to death. Groups such as MADD (Mothers Against DrunkDriving) are advocating for the responsible use ofalcohol.

Alcohol is usually considered to be a depressant butcan act as a stimulant in small doses. Alcohol affectsthe nervous system byincreasing the inhibitoryneurotransmitter GABA(Gamma Amici BiotypicAcid). It also modifies theeffects of another excitoryneurotransmitter calledglutamate. A blood alcoholcontent of 0.10 can induceblurred vision, slurredspeech, poor musclecoordination, and lack ofrational judgment. A bloodalcohol content of 0.40 to 0.50 will induce comaand a level of 0.60 will result in death. If a driver isfound to have a Blood Alcohol Concentrate of 0.05,they receive a fine and a 24 hours suspension of thelicence. If the driver is found to have a BAC (?)That 08 there is a fine and a car suspense. Alcoholabuse can lead to short-term memory loss andblackouts. It can irritate the gastrointestinal tractand increase hydrochloric acid production. Its long-term use can also cause liver disorders such ascirrhosis of the liver and heart disease.

Alcoholism is considered to be a genetic andenvironmental disease that can lead to death. Alcoholism is associated with addictive personalitiesand may be a secondary result of depression. Severealcoholics often appear jaundiced due to cirrhosis ofthe liver. Their immune systems are impaired andthey are more prone to disease. There areorganizations such as Alcoholics Anonymous thatenable sufferers of alcoholism and their families tocope with this disease.

MarijuanaA Canadian Senate committee has proposal thelegalization of marijuana for non-medical use, citingthat it is less harmful than alcohol. They believe thatmarijuana should be governed by the same laws asalcohol. They believe legalization would allow forbetter regulation and taxation of the drug. Manyargue that prohibition of drugs like marijuanasupports organized crime. It would also save moneyin law enforcement. This means that it couldpotentially be sold in corner stores. Others raise

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concerns about addiction and health concerns. There also concern that it may be the “gateway” toabuse of more dangerous drugs. It is believed that ifmarijuana is legalized , more teens will abuse thedrugs because access would be easier. As a result ofthis the Court of Canada has drafted legislation thatwould decriminalize marijuana usage. Individualspossessing a small amount of the drug would befined much like the a speeding ticket. It is quitepossible that within the lifetime of this modulemarijuana will be decriminalized.

Marijuana is derived from the Indian hemp plantCannabis sativa. The active compound in marijuanais tetrahydrocannabinol (THC) works by binding toCB1 receptors found on presynaptic membranes inthe brain. These receptorsfunction in blunting pain. THC also causes the releaseof the neurotransmitterdopamine which elevatesmood and controls musclemovements. Thebiochemical pathways canexplain the how the drugaffects its users and how itmay also be used for medicinal purposes.

In low concentrations, THC causes euphoria. It hasthe ability of enabling the user to block out pain,frustration or confusion. There are also some serioushealth concerns regarding the use of marijuana. Inhigh concentrations can cause hallucinations,anxiety, depression, and psychotic symptoms.Smoking marijuana can cause lung cancer, sinusitis,and bronchitis. It increases the level of carbonmonoxide in the blood which, in turn, reduces theamount of oxygen reaching the heart. Repeated usetends to lead to the inability to deal with everydaychallenges. Long term use can result in: impairedspeech; memory loss; difficulty in understandingcomplex ideas; insomnia; impaired visual perception;and infertility. Marijuana use has also been linkedto reducing immunity towards disease.

Marijuana has been demonstrated to have somepositive effects in the treatment of disease. It hasbeen used to treat medical conditions such as nauseain chemotherapy patients and to stimulate appetitein AIDS patients. It may also offer relief from pain

and reduce spasticity due to multiple sclerosis. It hasbeen shown to help sufferers of severe arthritis. Itcan be used as an anti-epileptic and anti-depressant. It is believed to be far less addictive than manyprescribed painkillers. Furthermore, it is believedthat marijuana could be manufactured in otherforms so that it does not have to be smoked andharm the lungs.

Regulations are now in place that permit sufferersfrom terminal illnesses and chronic conditions togrow and smoke their own marijuana. They mayalso designate someone to grow it for them. Atpresent, the Canadian Medical Society opposesmarijuana use for medicinal purposes because of thelack of clinical research. Debate continues amongthe medical community about prescribing the use ofmarijuana. The legal system, however, supports theuse of marijuana for medicinal purposes sincedenying an individual treatment that they believehelps their medical problem would be infringing ontheir human rights.

CocaineCocaine is derived from the plant Erthoxylon cocaand can be inhaled, smoked or injected. It results ina feeling of euphoria followed by depression.Cocaine acts by first stimulating the release ofnorepinephrine and dopamine and in higher dosesthe release of serotonin.Cocaine then interfereswith the re-uptake ofthese neurotransmittersand theseneurotransmitters buildup in the synapse. Prolonged use will causethe body to produce lessdopamine and the userwill need more cocaine. Side effects include mental impairment, convulsions,hallucinations, stroke, heart attack and death.

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HeroinHeroin is a highly addictive derivative of morphineand comes from the opium poppy, Papaversomniferum. Heroin is normally injected but canalso be snorted or smoked. It operates by binding toophioid receptors in the brain in which naturalchemical endorphins are involved in the relief ofpain. Heroin mimics the action of endorphins. After initial exposure users experience a surge ofcuphonia “Rush” followed by a drowsy trance-likeslate. Prolonged use can cause less endorphinproduction. Side effects include: depressedrespiration; impaired coordination; and decreasedtolerance to pain; long term effects can include:collapsed veins; infections of heart valves and liverdisease. Death can result from overdose.

RohypnolRohypnol is a drug associated with rave parties andcomes from the benzodiazepine family. It isconsidered to be the “date rape” drug and hasbecome famous for its use in committing sexualassault. It is often given to an unsuspecting victim bydissolving it in beverage while they are unaware. Itis similar to ValiumTM but has ten times its strength.In combination with alcohol, it can be deadly.Rohypnol is highly addictive and has severewithdrawal symptoms. Its use can cause deepsedation, respiratory distress, blackouts for up 24hours, and amnesia.

EcstasyEcstasy is known as Methylene Dioxy MethAmphetamine (MDMA) and has street names suchas X, Rolls, E, Adam, Beans and Buddies. It is one ofthe designer drugsassociated withrave parties.When Ecstasyfirst becamepopular, it wasbelieved to be a“safe” drug withno side-effects. Itwas soon discovered, like many drugs, to have deadlyconsequences with its abuse.

The initial use of ecstasy results in: increased heartrate; increased blood pressure; dilation of pupils andbronchi; brain stimulation; increased motor activity;

tightening of jaw muscles; grinding of jaws;overheating; sweating; heat stroke; and dehydration. Complications can result in renal failure, depression,liver failure, cardiovascular collapse and respiratoryfailure to name a few. The long-term use of ecstasycan result in irreparable brain damage. Its use isknown to damage the brain cells that produceserotonin. In fact, long after ecstasy use, the nervefibres in the brain that were destroyed by its use havegrown back abnormally or not at all.

Designer Drugs

Designer drugs are associated with undergroundhigh school and college parties called raves. They arecalled designer drugs because they are created byaltering the molecular structure of existing drugs toenhance their effects. They are prepared byunderground chemists known as “cookers”. “Cookers” are untrained and unlicensed chemiststhat work in poorly constructed laboratories. Ofcourse, these conditions offer little quality controland makes abuse of these drugs even moredangerous.

Designer drugs are derived from three different typesof drugs. These drugs are known as PCP, fentanyl,and amphetamine/methamphetamine. The streetdrugs created from these drugs are known as XTC,Ecstasy, Adam, Eve, Lover’s Speed, GHB, Special K,Fantasy and Nature’s Quaalude. Fentanylderivatives are known to be up to 1000 times morepotent than heroin. Ecstasy is derived fromamphetamine/methamphetamine in higher doses canresult in paranoia, depression and violent irrationalbehaviour. In general, designer drugs can create awide range of physical problems such as:hypertension; uncontrolled tremors; total paralysis;seizures; permanent brain damage; and death.

Prescription Drugs

In recent years, concernhas arisen over the abuseof prescription drugs. Some prescription drugsare easily addictive andpatients can experiencedifficulty withwithdrawal along with

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dangerous side effects. Adolescents are becomingfrequent abusers of prescription drugs due to theeffects of euphoria that can be produced by thesedrugs. Crimes of breaking and entering pharmaciesfor the purpose of stealing prescription drugs is onthe rise. There are three main prescription drugsthat are most commonly abused: Opioids, CNSdepressants and stimulants.

OpioidsOpioids are typically used to treat pain. Thesemedications fall into a class of narcotics and includemorphine, codeine and DemerolTM. Opioidsfunction by attaching to specific proteins calledopioid receptors. These receptors are found in thebrain, spinal cord and gastrointestinal tract. Whenopioids attach to the opioid receptors they are ableto block the transmission of pain messages to thebrain. Opioids can produce a feeling of euphoria byaffecting regions of the brain that enable us toperceive pleasure. However, they can result inphysical dependence and addiction. Tolerance ofopioids can result in the need to take higher doses toachieve the same effect. Withdrawal will cause:restlessness; muscle and bone pain; insomnia;diarrhea; vomiting; cold flashes; goose bumps; andinvoluntary leg movements. A large dose can lead torespiratory depression resulting in death.

CNS DepressantsCNS depressants are often used to treat anxiety andsleep disorders by slowing normal brain function. Common CNS depressants include barbiturates andValiumTM. Most CNS depressants act on the brainby affecting the neurotransmitter gamma-aminobutryic acid (GABA). The function of GABAin the human body is to decrease brain activity.Therefore, increased doses will create the drowsyeffect required to treat anxiety and sleep disorders. Individuals can build a tolerance to CNS depressantsover time and require larger doses. Withdrawals cancause the opposite effects of the drug. The mind canrace out of control, possibly resulting in seizures andother problems.

StimulantsStimulants are used to treat narcolepsy, obesity,depression, and attention-deficit hyperactivitydisorder (ADHD). These drugs enhance brainactivity and result in increased alertness, energy,

elevated blood pressure, increased heart rate andrespiration. Examples of stimulants includeRitalinTM and DexandrineTM. The chemicalstructure of stimulants is similar to the chemicalstructure of the neurotransmitters norepinephrineand dopamine. Stimulants work by increasing theamount of these neurotransmitters to the brain. Anincrease in dopamine results in an increase in bloodpressure, increase in heart rate, constriction of bloodvessels, increase in blood glucose and it opens thepathways of the respiratory system. Stimulants donot result in physical dependence or withdrawal. However, they can be used compulsively and highdoses repeatedly can lead to feelings of hostility andparanoia. High doses can cause body temperaturesto rise to a dangerously high level. They can alsocreate an irregular heartbeat leading to the risk ofcardiovascular failure. There is also the potential oflethal seizures.

Conclusion

Drugs can play a role in both maintaining anddisrupting homeostasis. When problems in theneurotransmitter balance occur, such as in the caseof mental illness, drugs can play a role in restoringthe balance. However, further study into the effectsof different neurotransmitters is essential to achieve abetter understanding of diseases caused byneurotransmitter imbalance. This can lead to betterdrug treatments that have less serious side-effects. Drug abuse can also disrupt homeostasis. Understanding the effects of drug abuse on neuralpathways and the overall health of an individual canaid in the education of individuals considering drugabuse. It can also aid in the treatment of thosesuffering from addiction. Understanding theseriousness of drug abuse on long-term health maymake one think twice about engaging in the legaland illegal use of drugs.

Questions

Understanding Concepts1. For each mental illness, (clinical depression,

bipolar disorder and schizophrenia) list theneurotransmitters involved, the nature of theimbalance of the neurotranmitter, the drugsused in their treatment, and side-effects of each

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of these drugs. This may be done in the form ofa chart.

2. For each street drug, (alcohol, marijuana,cocaine, heroin, RohypnolTM and ecstasy) list theeffects on neural pathways, the short-term effectsof the drug and the long-term effects of thedrug.

3. What are the dangers of using designer drugs?

4. For each of the prescription drugs, (opioids, CNSdepressants and stimulants) list the effects onneural pathways, the short-term effects of thedrug and the long-term effects of the drug.

Extensions1. Debate the pros and cons of the use of

marijuana in the treatment of chronic pain.

2. Debate the merits of whether or not to use drugsfor treatments of nervous such as mental illnessdisorders against the side effects of these drugs.

3. Debate the merits of legalizing marijuana. Research the present legislation regarding thelegalization of marijuana.

4. Using the knowledge that you have gainedabout the causes of mental illness, respond tothe following statement; “Mental illness is afigment of one’s imagination and one can chosewhether or not to control their thoughts.”

5. Choose a drug of interest to research. Reportyour findings in the form of a magazine article.

6. Write a letter to a friend who you know isabusing drugs. In this letter, use what you knowabout the dangers of drug use to persuade themquit and seek help.

References

Bullard, Chetty et al. (2003). Biology. McGraw-Hill Ryerson. Toronto

Brown, DeNeen L. (2002). Canadian Panel BackLegalizing Marijuana. WP Foreign Press. Availableat:

http://www.cannibisnews.com/news/thread14010.shtml

Common Drugs and Their Symptoms. Available at:www.cornerdrugstore.org/CommonDrugsPage.htm

Drug Abuse: Chemical Changes in the Brain. Available at:www.epub.org.br/cm/n08/doencas/drugs/abuse06_i.htm

Drugs and the Nervous System. Available at:http://learn.dccc.edu/~saquilan/ppt/nervous/sld056.html

Drugs and the Nervous System. Available at:http://users,rcn.com/jkimball.ma.ultranet/BiologyPages/D/Drugs.html

Facts about Manic Depression. Missouri Councilfor Comprehensive Psychiatric Services. Availableat: www.parquad.org/mdfacts.htm

NIDA- Research Report Series – Marijuana Abuse. Available at:wysiwyg://86http://www.nida.nih.gov/ResearchReports/Marijuana/Marijuana3.html

Research Report Series – Prescription Drugs: Abuseand Addiction. Available at:wysiwyg://143/http://www.nida.nih.gov/Re...hReports/Prescription/prescription2.html

www.nida.nih.gov/Infofax/heroin.htmlSANE. Available at:www.sane.org.uk/About_Mental_Illness/

The Nervous System. Available at:www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBoookNERV.html

Timmons and Hamilton. Drugs,Brain and Behavior– Ch. 6. Available at:www.rci.rutgers.edu/~lwh/drugs/chap06.htm

Timmons and Hamilton. Drugs,Brain and Behavior– Ch. 7. Available at:www.rci.rutgers.edu/~lwh/drugs/chap07.htm.

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Wadler,Gary. Designer drugs. Available at:http://espn.go.com/special/s/drugsandsports/

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Outcomes:1. Identify examples of technologies that were developed based on understanding of cell division. (116-3)

2. Describe disorders linked to the nervous system and their effect on the homeostasis of the system andthe organisms as a whole. (317-4)

3. Analyse why and how technologies related to the treatment of nervous system disorders weredeveloped and improved over time. (115-5)

4. Select and integrate information on the application of technologies based on cell division. (213-7)

5. Construct arguments to support a decision, using examples and evidence and recognizing variousperspectives. (118-6)

6. Debate the merits of funding specific scientific or technological endeavors and not others. (117-4)

Stem Cell Research

Introduction

Imagine that your father has been diagnosed withParkinson’s disease and you begin to watch hiscondition deteriorate. Tremors become moreevident and his movement more rigid. He is unableto enjoy his normal day to day activities. You fearhow the debilitation of this disease will affect hishuman spirit and you know the condition can onlyget worse. You hear of countries in Europe who aretransplanting embryonic stem cells in the brains ofParkinson’s patients. It is a relatively new treatmentthat is considered unethical in North America due tothe lack of research and the use of embryonic stemcells. You begin to ask yourself questions about theethical use of an embryos’ stem cells to treat yourfather. If you pursue this treatment, will you besacrificing the life of an unborn child for yourfather’s quality of life?

When does human life begin? The scientificcommunity, the pro-life movement and the pro-choice movement have debated this question for anumber of years. The onset of stem cell research hasadded another dimension to this debate. Is itmorally acceptable to cultivate cells from a humanembryo to cure a terminal disease? From where doscientists obtain these embryos? Should thetherapeutic cloning of an individual be permitted inorder to cure a disease of this individual? Whathappens to the embryo from which the stem cells

were retrieved? As these questions are being debated,scientists are considering such scientific endeavors ashow stem cells can be used to understand and treatcancer, researching how stem cells can be used totreat spinal cord injuries and how stem cells canprovide a cure for Parkinson’s disease.

What are Stem Cells?

When the human egg is fertilized with sperm, all thegenetic information is in place to begindevelopment. Scientists are beginning to understandhow a single fertilized egg cell can divide into amulticellular organism with cells that havedifferentiated to perform a variety of purposes. Eachof these differentiated cells has been derived from asingle cell and, despite performing differentfunctions, contains identical genetic information.These undifferentiated cells are known as stem cellsand have the ability to form any type of cell in ourbodies. The inner cell mass of the blastocyst containsstem cells that later differentiate into the hundreds ofspecialized cells that make up the human organism. Inadults, stem cells can be found in tissue such as: the bonemarrow; skin; liver; peripheral blood; blood vessels;muscle; and brain. The stem cells in adults are used toreplace cells that need to be replaced through normal wearand tear, cells that have been damaged through injury,and cells that have been damaged through disease.

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Stem cells have three unique properties. First, theyhave the ability to divide and renew themselves for along period of time. Secondly, they areunspecialized. Thirdly, they have the ability todifferentiate into specialized cells.

Types of Stem Cells

There are two main types of stem cells that scientistsare interested in studying: embryonic stem cells andadult stem cells. Embryonic stem cells can beobtained from the inner cell mass of the blastocystfour or five days after fertilization. Embryonic stemcells can be also derived from a five to ten week oldfetus. It is more common to use stem cells from theblastocyst rather than the fetus. Embryonic stemcells are considered to be pluripotent which meansthey may eventually give rise to any type of cell inthe human body. Ethical issues arise from the use ofembryonic stem cells since the embryos are destroyed

and the debate continues to rage about when lifebegins.

Initially, adult stem cells were believed to mainlygive rise to the types of cells of the tissue for whichthey were found. However, recent research hasbeen exploring the possibility that adult stem cellsfrom one tissue may be able to differentiate into cellsof another tissue type. This is known as

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transdifferentiation or plasticity. This is an area ofresearch that is rapidly advancing, especially since itavoids the ethical issue of using stem cells fromembryos. For example, hematopoietic stem cellsnormally give rise to all the types of blood cells. Recently, they have shown the ability to differentiateinto brain cells, skeletal muscle cells, cardiac musclecells and liver cells. Bone marrow stromal cellsnormally give rise to bone cells, cartilage cells, fatcells, and other types of connective tissue cells. However recent research is showing that they maydifferentiate into cardiac muscle cells and skeletalmuscle cells. Brain stem cells can be shown todifferentiate into blood cells and skeletal musclecells.

If adult stem cells are able to demonstrate plasticitythen it is believed that liposuction could potentiallyprovide a source of stem cell since they have beenknown to reside in fat tissues. Discarded humanumbilical cords and human placentas could alsoprovide valuable sources of stem cells. In the future,a person could also be asked to donate their stemcells to be used later in life, if the need arises.

Present Research

Stem cell research began over 20 years ago whenscientists isolated stem cells from mouse embryos. Human stem cells were first isolated from humanembryos in 1998. These human embryos wereobtained through embryos that were produced forthe purpose of in vitro fertilization and were nolonger required by the donor for fertility purposes. In this case, the donor was required to provideinformed consent for their embryos to be used instem cell research. Scientists are presently trying to understand twomain properties of stem cells. First, they would liketo understand how stem cells can remainunspecialized for a period of time and renewthemselves for a period of years. Secondly, scientistswould also like to understand the signals thateventually cause cells to differentiate into specializedcells. Scientists believe that certain genes within acell must be “turned on” and other genes must be“turned off” to become these specialized cells. Thisfundamental knowledge would enable scientists todevelop treatment for diseases in which cells have

been damaged beyond the means of the body tonormally repair themselves.

Scientists have found that embryonic stem cells thatdivide within the laboratory, renew themselveswithout differentiating for a year or more. The samecan not be said for adult stem cells at present.Scientists are hoping to understand the processesthat regulate stem cells division to remainunspecialized and proliferate compared to theprocesses that lead to the differentiation of cells. This knowledge can enable scientists to growembryonic adult stem cells in the laboratory moreeffectively. It has actually taken twenty years forscientists to learn how to grow embryonic stem cellswithout them spontaneously differentiating intospecialized cells. The ability to grow large numbersof unspecialized cells in the laboratory is critical tocontinued research.

Scientists believe that certain genes are found withinstem cells that produce internal signals that guidecell differentiation. They also believe that there areexternal signals that guide cell differentiation. Thesesignals include chemicals secreted by other cells,physical contact with neighbouring cells and thepresence of certain molecules. Understanding thesesignals can better enable scientists to learn how tocontrol the differentiation into the desired cell type.

Scientists are also learning to direct thedifferentiation of stem cells through a variety oftechniques. Such techniques include changing thechemical composition of the medium, altering thesurface of the culture dish or modifying the cells byinserting specific genes. The development andrefinement of techniques that control differentiationwill eventually lead to cells that can be transplantedto cure diseases such as heart disease, musculardystrophy and diabetes.

Finally, scientists are developing methods oftherapeutic cloning. (Also known as somatic celltransfer.). Stem cells are created by transferringgenetic material from a transplant recipient into anegg cell. This egg cell is stimulated to divide andproduce stem cells that contain identical geneticinformation as the patient. However, this processhas resulted in several ethical debates. Does theproduction of these stem cells result in the

APPENDIX C


production of an embryo that is later destroyed? Isthis process essentially the cloning of an individual?

The Technique of Culturing Embryonic

Stem Cells

Millions of stem cells can be cultured fromapproximately 30 cells taken from the inner cell massof the blastocyst in about six months.

When the cells from the inner cell mass are removed,they are transferred to a plastic laboratory culturedish. This culture dish contains a nutrient broth. The inner surface of the culture dish is coated with afeeder layer. This layer contains mouse

embryonic skin cells that are treated so that theywill not divide. The feeder layer is importantbecause it provides the inner cells mass with a stickylayer to which they may adhere. It also releasesnutrients into the culture medium. The feeder layerof mouse embryonic stem cells does pose someproblems in that viruses and other macromoleculescould be transmitted to human cells. Scientists arepresently developing methods of culturing humanstem cells that do not require the mouse feeder cells.

The stem cells will divide very quickly andovercrowd the culture dish. They will then be platedto other culture dishes. This process of replating willcontinue for about six months. Stem cells can befrozen and used later for experimentation.

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The Potential use of Stem Cells in the

Treatment of Disease

As discussed earlier, stem cells are useful in researchbecause they are unspecialized cells that have thepotential to differentiate into specialized cells.

Specialized cells in the human body that have beendamaged through injury or disease could be replacedby stem cells if these stem cells can be induced todifferentiate into the cell type that has beendamaged. This is known as cell-based therapies. Forexample, this means that stem cells can potentiallybe used to replace damaged cells of the pancreas thatno longer produce insulin. Stem cells couldpotentially replace the nervous cells that havedeteriorated in an individual with Parkinson’sdisease. There are a great many other diseases andconditions that may be treated through the successof stem cell research. They include: spinal cordinjury; stroke; Alzheimer’s disease; burns;osteoarthritis; rheumatoid arthritis; cancer; Purkinjecell degeneration; Duchenne’s muscular dystrophy;heart disease; vision loss; and hearing loss. Scientistsare specifically working on the directeddifferentiation of adult stem cells in the treatment ofParkinson’s disease, diabetes and heart disease. These specific cell types include dopamineproducing neurons, insulin-producing cells andcardiac muscle cells.

In Parkinson’s disease, a particular nerve cell orneuron called the dopamine (DA) producing neuronhave been degenerated or destroyed. Loss of the DAneuron leads to the tremor, rigidity and loss ofmobility observed in Parkinson’s patients. Studieson mice with Parkinson’s disease indicate that whendopamine producing neurons were transplanted intothe brains of mice the symptoms of Parkinson’s werealleviated. Scientists are now trying to producedopamine producing neurons from human stemcells for neurotransplantation of Parkinson’s patients. It is quite possible that within the lifetime of thismodule, a cure for Parkinson’s disease could befound.

As the knowledge of how stem cells differentiateunfolds, a better understanding of diseases caused byabnormal cells division and differentiation such ascancer can be obtained and ultimately lead to a cure.Understanding these processes can also lead to theprevention of birth defects.

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The use of stem cells in cancer treatment can have awide range of applications. Cancer cells and stemcells both have the ability to renew themselves. Understanding these processes can help scientistsunderstand why cancer cells resist aggressivetreatments and continue to proliferate. As well,cancer treatments such as chemotherapy can cause ahigh degree of damage to healthy cells and tissues inthe body. Stem cells can be used to restore theimmune system for aggressive cancer treatments. Embryonic stem cells could also be used to restorethe immune system of patients undergoing bonemarrow transplants. Stem cells may eventually be produced that areresistant to chemotherapy and therefore betterenable patients to deal with the effects ofchemotherapy. In addition, stem cells could be usedto create cancer vaccines by providing antibodiesagainst cancer cells.

The Benefits and Risks of

Embryological Stem Cells and Adult

Stem Cells

Most of the debate around stem cell research centersaround the use of embryological stem cells asopposed to adult stem cells. Embryonic stem cells

can differentiate into any type of specialized cells. The plasticity of adult stem cells is only presentlybeing investigated and more research is needed todetermine how adult stem cells can differentiate intoother types of cells. Researchers have learned how toculture embryonic stem cells in large numbers forthe past twenty years. Adult stem cells are difficultto find in mature tissues and researchers have notdeveloped techniques to culture them in largenumbers.

The use of adult stem cells from a patient offers adistinct advantage in that this patient will not rejecttheir own stem cells after transplantation. Not onlyis the risk of rejection eliminated from the patient’simmune system but also immunosuppressant drugswill not be necessary. It has not been determinedwhether a patient would reject stem cells from adonor such as in the case of the use of embryonicstem cells.

There is the potential that stem cells derived from anembryo could contain viruses or diseases that couldbe transmitted to the patient. There is also aconcern that these stem cells lead to the developmentof tumors after transplantation.

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Conclusion

Research on the use of stem cells is advancing fast.Stem cells research has also gained momentumthrough the involvement of such celebrities asMichael J. Fox and Christopher Reeves. Stem cellscould be used to replace the damaged neurons in thebrain of Parkinson’s patients such as Michael J. Fox. They could also be used to repair the damaged spinalcord tissue such as in the case of Christopher Reeves. Some however, will argue that one should notdevalue human life from the moment of conceptionuntil death and that it would be immoral to useembryonic stem cells in the treatment of disease. Atpresent, the Canadian Institute of Health Researchhas developed guidelines that prohibit cloning andthe production of embryos strictly for researchpurposes. Research on embryos is only permitted ifthose embryos were developed for reproductivepurposes and they are obtained with full informedconsent. The debate about the ethical use of stem cells rageson in society. In the meantime, researchers continuetheir work with stem cells from the existing embryosproduced through in vitro fertilization and aredeveloping the possibilities from adult stem cells. They must do this in the hope of finding successfultreatments for disease and damaged tissue whilerespecting the ethical issues surrounding the debateof stem cell research.

References

Cohen, Elizabeth. Actor Christopher Reeve believesthat embryonic stem cell research will allow him towalk again one day. CNN Medical Correspondent

Hedrick, Marc (2001). Life Must Take Priority overResearch. Available at:http://www.prolifeinfo.org/stemcell038.html

NCIC Media Release. Human Embryonic StemCell Research Guidelines Announced TodaySupported by the Canadian Cancer Society and theNational Institute of Canada. Available at:http://www.neic.cancer.ca/pubs/media/02/mar4_e.htm

Text of Bush Speech on Embryonic Stem CellResearch. Available at:http://www.prolifeinfo.org/stemcell033.html

Public Funding of Stem Cell Research EnhancesLikelihood of Attaining MedicalBreakthroughs. Stem Cells and the Future of Regenerative Medicine. The National Academies. Available at:http://www4.nationalacademies.org.news.nsf/ibsn0309076307?OpenDocument

Stem Cells and Regenerative Medicine. TheNational Academies. Available:http://www4.nas.edu/onpi/webextra.nsf/44

Stem Cells: A Primer. Available:http://www.nih.gov/news/stemcell/primer.htm

The Center for Bioethics and Human Dignity. Available:http://cbhd.org/resources/overview/stemcell.html

Questions

Understanding Concepts1. Construct a table that outlines the benefits and

risks of using embryological stem cells comparedto adult stem cells.

2. What are the potential sources of embryologicalstem cells? What are the potential sources ofadult stem cells?

3. What are three properties possessed by stem cellsthat scientists find valuable in their research touse stem cells to treat disease?

4. Describe what scientists know about the factorsthat cause the differentiation of cells.

5. What techniques have scientists begun todevelop that direct the differentiation of stemcells?

6. What is meant by cell-based therapies?

7. Describe the process of therapeutic cloning.

8. Briefly outline the steps used to culture largenumbers of embryonic stem cells.

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Extensions1. Scientific research in the use of stem cells is fast

advancing. This is an opportunity for studentsto update this module in regards to the latestresearch. Research the most current research inany of the following areas:• The use of embryological stem cells. Are

scientists still using embryological stemcells? From where are these stem cellsobtained? What are the present advantagesoffered by the use of these stem cells? Whatare the present disadvantages offered by theuse of these stem cells? If these types ofstem are not being used, why not.

• The use of adult stem cells. Are scientistsstill using adult stem cells? From where arethese stem cells obtained? What are thepresent advantages offered by the use ofthese stem cells? What are the presentdisadvantages offered by the use of thesestem cells? If these types of stem are notbeing used, why not.

• The use of stem cells in cell basedtherapies. What disorders are presentlybeing explored as disorders that may benefitfrom stem cell research? Are there anydisorders that are being successfully treatedthrough the use of stem cells? Are thesetherapies using embryological or adult stemcells? What are some possible/potentialproblems with these treatments?

• The use of stem cells in developing drugs. What type of research is taking place inregard to developing drugs to treat disease? Are stem cells being used successfully in thedevelopment of drugs to treat disease? If so,what types of diseases?

This research may be done individually or bystudent groups. Presentations may be a valuable wayfor students to share what they have learned.

2 Explore the latest stem cell research in regard tothe treatment of a particular disease or disorder. Examples may include Parkinson’s Disease,diabetes, spinal cord injury, stroke, Alzheimer’sDisease, burns, osteoarthritis, rheumatoidarthritis, cancer, Purkinje cell degeneration,Duchenne’s muscular dystrophy, heart disease,vision loss and hearing loss. This may bepresented in the form of a paper or classpresentation.

3. Read each of the following articles. Each articlepresents views on the ethical use of stem cells inresearch. Using the background knowledge thatyou have obtained in this module and thearguments presented in these articles, developyour own arguments for or against the use ofstem cell research.

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Actor Christopher Reeve believes that embryonic stem cell research willallow him to walk again one day.

Stem cells are blank human cells that scientists think might be turned into any type of tissue, specificallytissue that might be used to repair -- in Reeve's case, for example -- damaged spinal cord cells.

Some scientists believe that stem cells from fertilized human eggs, known as embryos, hold the most promisefor success.

"If you had the FDA (Food and Drug Administration) involved and everybody working together, I ampositive in 10 years I'd be on my feet ... I would not be sitting here in a wheelchair," Reeve said.

Reeve, who was paralyzed in a May 1995 horse-riding accident, has joined the debate in the United Statesover whether the federal government should fund research on stem cells from human embryos created by in-vitro fertilization. Many abortion opponents -- including Pope John Paul II -- also oppose using humanembryos for research.

The decision is up to U.S. President George W. Bush, who met Monday with the pontiff in Italy.

There, the pope compared embryo research to euthanasia and infanticide. "A free and virtuous society,which America aspires to be, must reject practices that devalue and violate human life at any stage fromconception until natural dead," the Pope said.

It was only recently that scientists began creating embryos specifically for stem cell research. Before that,most embryos for such experiments were fertilized eggs that parents decided not to use for pregnancy andotherwise would have been discarded.

While not directly responding to John Paul's comments, Reeve said that the issue is not about ethics. "Youreally don't have an ethical problem because you're actually saving lives by using cells that are going to thegarbage," Reeve said. "I just don't see how that's immoral or unethical. I really don't."

In the near future, there is a chance that scientists might be able to obtain stem cells from less-controversialsources, such as umbilical cords. But some researchers say those kinds of cells might never be as medicallyuseful as stem cells from human embryos.

CNN Medical Correspondent Elizabeth Cohen contributed to this report.

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Subject: Text of Bush Speech on Embryonic Stem Cell ResearchSource: Reuters; August 9, 2001

Text of Bush Speech on Embryonic Stem Cell Research

Following is the text of U.S. President George W. Bush's speech on Thursday announcing his decision toprohibit any federal funding for new embryonic stem cell research:

Good evening. I appreciate you giving me a few minutes of your time tonight so I can discuss with you acomplex and difficult issue, an issue that is one of the most profound of our time.

The issue of research involving stem cells derived from human embryos is increasingly the subject of anational debate and dinner table discussions. The issue is confronted every day in laboratories as scientistsponder the ethical ramifications of their work. It is agonized over by parents and many couples as they try tohave children or to save children already born.

The issue is debated within the church, with people of different faiths, even many of the same faith, comingto different conclusions.

Many people are finding that the more they know about stem-cell research, the less certain they are aboutthe right ethical and moral conclusions.

My administration must decide whether to allow federal funds, your tax dollars, to be used for scientificresearch on stem cells derived from human embryos.

A large number of these embryos already exist. They are the product of a process called in vitro fertilizationwhich helps so many couples conceive children. When doctors match sperm and egg to create life outside thewomb, they usually produce more embryos than are implanted in the mother. Once a couple successfullyhas children or if they are unsuccessful, the additional embryos remain frozen in laboratories. Some will notsurvive during long storage, others are destroyed. A number have been donated to science and used to createprivately funded stem-cell lines. And a few have been implanted in an adoptive mother and born and aretoday healthy children.

Based on preliminary work that has been privately funded, scientists believe further research using stem cellsoffers great promise that could help improve the lives of those who suffer from many terrible diseases, fromjuvenile diabetes to Alzheimer, from Parkinsons to spinal cord injuries. And while scientists admit they arenot yet certain, they believe stem cells derived from embryos have unique potential.

You should also know that stem cells can be derived from sources other than embryos: from adult cells, fromumbilical cords that are discarded after babies are born, from human placentas. And many scientists feelresearch on these types of stem cells is also promising. Many patients suffering from a range of diseases arealready being helped with treatments developed from adult stem cells.

However, most scientists, at least today, believe that research on embryonic stem cells offers the mostpromise because these cells have the potential to develop in all of the tissues in the body.

Scientists further believe that rapid progress in this research will come only with federal funds. Federaldollars help attract the best and brightest scientists. They ensure new discoveries are widely shared at thelargest number of research facilities, and that the research is directed toward the greatest public good.

The United States has a long and proud record of leading the world toward advances in science andmedicine that improve human life, and the United States has a long and proud record of upholding thehighest standards of ethics as we expand the limits of science and knowledge.

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Research on embryonic stem cells raises profound ethical questions, because extracting the stem cell destroysthe embryo, and thus destroys its potential for life.

Like a snowflake, each of these embryos is unique, with the unique genetic potential of an individual humanbeing.

As I thought through this issue I kept returning to two fundamental questions. First, are these frozenembryos human life and therefore something precious to be protected? And second, if they're going to bedestroyed anyway, shouldn't they be used for a greater good, for research that has the potential to save andimprove other lives?

I've asked those questions and others of scientists, scholars, bioethicists, religious leaders, doctors,researchers, members of Congress, my Cabinet and my friends. I have read heartfelt letters from manyAmericans. I have given this issue a great deal of thought, prayer, and considerable reflection, and I havefound widespread disagreement.

On the first issue, are these embryos human life? Well, one researcher told me he believes this five-day-oldcluster of cells is not an embryo, not yet an individual but a pre-embryo. He argued that it has the potentialfor life, but it is not a life because it cannot develop on its own.

And while we must devote enormous energy to conquering disease, it is equally important that we payattention to the moral concerns raised by the new frontier of human embryo stem cell research. Even themost noble ends do not justify any means.

My position on these issues is shaped by deeply held beliefs. I'm a strong supporter of science andtechnology, and believe they have the potential for incredible good -- to improve lives, to save life, toconquer disease. Research offers hope that millions of our loved ones may be cured of a disease and rid oftheir suffering. I have friends whose children suffer from juvenile diabetes. Nancy Reagan has written meabout President Reagan's struggle with Alzheimer's. My own family has confronted the tragedy of childhoodleukemia. And like all Americans, I have great hope for cures.

I also believe human life is a sacred gift from our creator. I worry about a culture that devalues life, andbelieve as your president I have an important obligation to foster and encourage respect for life in Americaand throughout the world.

And while we're all hopeful about the potential of this research, no one can be certain that the science willlive up to the hope it has generated.

Eight years ago, scientists believed fetal tissue research offered great hope for cures and treatments, yet theprogress to date has not lived up to its initial expectations. Embryonic stem cell research offers both greatpromise and great peril, so I have decided we must proceed with great care.

As a result of private research, more than 60 genetically diverse stem cell lines already exist. They werecreated from embryos that have already been destroyed, and they have the ability to regenerate themselvesindefinitely, creating ongoing opportunities for research.

I have concluded that we should allow federal funds to be used for research on these existing stem-cell lines,where the life-and- death decision has already been made.

Leading scientists tell me research on these 60 lines has great promise that could lead to breakthroughtherapies and cures. This allows us to explore the promise and potential of stem cell research withoutcrossing a fundamental moral line by providing taxpayer funding that would sanction or encourage furtherdestruction of human embryos that have at least the potential for life.I also believe that great scientific progress can be made through aggressive federal funding of research on

APPENDIX C


umbilical cord, placenta, adult and animal stem cells, which do not involve the same moral dilemma. Thisyear your government will spent $250 million on this important research.

I will also name a president's council to monitor stem-cell research, to recommend appropriate guidelinesand regulations and to consider all of the medical and ethical ramifications of biomedical innovation.

This council will consist of leading scientists, doctors, ethicists, lawyers, theologians and others, and will bechaired by Dr. Leon Cass, a leading biomedical ethicist from the University of Chicago.

This council will keep us apprised of new developments and give our nation a forum to continue to discussand evaluate these important issues.

As we go forward, I hope we will always be guided by both intellect and heart, by both our capabilities andour conscience. I have made this decision with great care, and I pray it is the right one.

Thank you for listening. Good night, and God bless America.

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Outcomes:1. Predict the effects of mutations on protein synthesis, phenotypes, and heredity. (315-7)

2. Describe factors that may lead to mutations in cell’s genetic information. (315-6)

3. Explain the circumstances that lead to genetic disease. (315-8)

4. Demonstrate an understanding of genetic engineering, using knowledge of DNA. (315-9)

5. Describe and evaluate the design of technological solutions and the way they function, using geneticprinciples. (116-6)

6. Construct arguments to support a decision or judgment concerning the use of genetic engineering,using examples and evidence and recognizing various perspectives. (118-6)

7. Analyze and describe examples where genetics based technologies were developed and based onscientific understanding. (116-4)

8. Analyze from a variety of perspectives the risks and benefits to society and the environment of applyingthe scientific knowledge gained through the genetic research. (118-2)

9. Identify and describe science and technology-based careers related to the field of biotechnology. (117-7)

Genetics Research in Newfoundland and

Labrador

Introduction

If you had the opportunity to help scientists cure aparticular disease, would you do so? Most peoplewould likely say, yes. There are many people acrossNewfoundland and Labrador who are doing exactlythat. They are giving consent to a local companycalled Newfound Genomics to use their DNA ingenetic research.

Newfoundland and Labrador has become the focusof some exciting research in the field of genetics inrecent years. Newfound Genomics Incorporated is abiotechnology company that was established inNewfoundland and Labrador in June 2000 to studyhow genes affect human health and disease. Genomics is the study of how genes apply to healthand disease.

Founder Populations

Newfoundland’s current inhabitants arose fromabout 20,000 to 30,000 immigrants from Ireland,Scotland and Southwest England in the late 1600’sto the 1840’s making those early immigrantsNewfoundland’s founding population. Thepopulation grew largely from expansion rather thanthrough immigration, which limited geneticdiversity. Certain genetic traits became moreprevalent in the new population while other traitswere eradicated. This explains why, compared toother populations, there is a higher incidence ofsome diseases in Newfoundland while some otherdiseases are rare or non-existent.

Newfound Genomics and their Research

Scientists at Newfound Genomics are presentlystudying some common diseases in Newfoundland

APPENDIX C


and Labrador. These diseases include obesity, type 2diabetes, inflammatory bowel disease andosteoarthritis. Their research includes clinical,environmental and genetic factors of these diseases. They will also examine relationships betweendifferent diseases. Other diseases are also beingexamined through partnerships with other academicinstitutions. Future studies may includeinflammatory arthritis and, respiratory, infectiousand dermatological diseases.

Genes and Disease

DNA in our cells is used to make proteins. Whengenes in our DNA are altered, the proteins producedby them are altered as well, and we become moresusceptible to disease. Some of these variations in thegenetic code are referred to as Single NucleotidePolymorphisms (SNPs). In the case of SNPs, anucleotide substitution has taken place in thegenome. Other variants in the genome includeinsertions and deletions in the nucleotide sequence.

Some SNPs have already been identified asassociated with some diseases. The Affymetrix® andMassARRAY genotyping systems are two types oftechnology discussed later that scientists are using todetermine if an individual possesses the geneticmake-up (SNP) that contributes to a particulardisease. Imagine that you can now provide a geneticscompany with a swab of your cheek cells and theycan use this technology to determine the presence ofvariation in your genome that can either diagnose aparticular disease or predict the onset of a disease.

Other SNPs have not been identified with anydisease. These SNPs may have no effect on thehealth of the individual or the SNP may have yet tobe connected to a particular disease. This is largelythe work that researchers at Newfound Genomicsare performing. They can examine the genome forSNPs and are hoping to make connections betweenindividuals with a particular SNP and a disease. Researchers can then examine the sequences ofnucleotides in these SNPs in more detail tounderstand their effect on disease.

A better understanding of the sequences of thesegenes can lead to a better understanding of thephysiological effects of their variations. This may, in

turn, lead to the development of drugs that mayrestore the normal functioning of the affectedprotein. This is a more revolutionary way of treatingdisease. Instead of treating the symptoms of adisease, scientists are discovering the exact cause of adisease in regard to the genetic variation. Determining the precise genetic cause and theaffected protein, will likely greater enable scientiststo treat the cause of a disease as opposed to thesymptoms.

Laboratory Technology

Scientists at Newfound Genomics obtain DNAsamples and supporting medical information frompatient donors. The DNA samples taken frompatient volunteers are either in the form of bloodsamples or buccal cells. Buccal cells are epithelialcells taken from the inside of the cheek. DNA isthen extracted from either the blood samples or thebuccal cells.

DNA Extraction

Laboratory technologists extract DNA using bloodcells or buccal cells. The DNA can be extractedusing a kit from a scientific supply company.

In the case of blood samples, DNA extraction beginswith lysing the red blood cells and collecting thewhite blood cells. A solution (enzyme) is then usedto break down the lipid membranes of the cells andthe nuclei of the cells to release DNA. Anothersolution is used to remove protein from the DNAsample. The DNA is precipitated in alcohol. Afterdrying, the DNA is dissolved in a solution used toprotect the DNA from enzymes that cause shearing. In the case of buccal cells, the same procedure isused but does not include the red cell lysis step. After DNA extraction has taken place, freezers areused to store DNA at -86/ C for an indefinite periodof time for analysis and further study.

DNA Genotyping

Scientists will use the DNA samples to carry out aprocess called genotyping. This is considered to beanalysis using genetic markers. Researchers atNewfound Genomics are presently looking at gene

APPENDIX C


markers that could indicate the presence of a genesequence contributing to a particular disease. A genemarker is a specific portion of a chromosome thatlies near a particular gene or is part of a particulargene that is being studied. Once the gene marker isidentified, a probe can be developed to search for thegene marker in other DNA samples. This probeconsists of a DNA sequence that is complementaryto the sequence of the gene marker. Sometimes thisprobe also contains a radioactive or fluorescentchemical tag so it can easily be determined if itbonds to the gene marker.

Newfound Genomics uses three methods ofgenotyping:

Basic Molecular GenotypingThis involves a PCR reaction to amplify DNA. Areview of PCR amplification is found in Figure 1. Specific primers have been developed for the variantto be examined in the genome.

Gel electrophoresis is then used to determine if thevariant is present. In gel electrophoresis, a 2%agarose gel is used with ethidium bromide (EtBr)stain to adhere to the DNA. The EtBr willilluminate with UV light. If the variant is present inthe DNA sample, then the primer would haveenabled the DNA to amplify and the EtBr wouldbind to the DNA and would be evident in UV light.

This is a more time consuming method ofgenotyping and tends to be used with small projects. With the new MassARRAY technology recentlyimplemented at Newfound Genomics, it will likelybe used less often.

Affymetrix® GenotypingThe Affymetrix technology will perform a generalscan of the genome. It contains a gene chip that hasthe capability of scanning for the presence of SNPs. The Affymetrix System at Newfound Genomics hasa gene chip that can search for 1500 SNPs. A chip ispresently being developed that can scan for 10, 000SNPs. As discussed earlier, it can be used todetermine if a SNP known to contribute to disease ispresent or to make connections between thepresence of SNPs and the appearance of a disease.

The Affymetrix technology can also be used in

gene expression studies. In gene expression studies,scientists are examining particular genes that may be“turned on” or “turned off” during the differentstages of a disease.

The Affymetrix technology incorporates PCR intoits technology. It will use probes in its technology tosearch for genetic markers. It also uses fluorescentchemical tags in other aspects of its technology todetect the presence of genetic markers.

MassARRAY Genotyping The MassARRAY technology is more specificthan the Affymetrix and can compare a greaternumber of parameters for experimental work. The MassARRAY will analyse genetic samplesfor a particular SNP or a number of SNPs. It iscapable of examining from either the entiregenome, several areas of the genome or onespecific area of the genome for a SNP. It canexamine the genetic information for oneindividual or many individuals for one or manySNPs. In addition, it can examine and comparea large number of individuals for SNPs. Likethe Affymetrix, it is useful is making theconnection between the presence of a SNP anda disease. It can also examine the genome forthe presence of SNPs that are known to berelated to disease.

The MassARRAY also incorporates PCR into ittechnology in addition to the use of primers. Sequenom Inc, a partner of Newfound Genomics,developed this technology.

Ethics

All studies at Newfound Genomics are approved bythe HIC (Human Investigations Committee) at theFaculty of Medicine. Donor volunteers are requiredto give their full informed consent. This consentallows researchers to use the donor volunteers’ DNAfor one particular study, or it may allow researchersto use a donor volunteers DNA for similar studieslater. All participants must be volunteers since it isconsidered unethical to purchase body fluids inCanada. Newfound Genomics does not provideindividual feedback to participating volunteersregarding their specific genetic makeup. The genetic

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information obtained is pooled with informationfrom all participating volunteers with a similarmedical condition.

The main ethical issue concerning the use of donorvolunteers’ DNA deals with privacy. Newfound Genomics does not provide insurancecompanies nor employers’ access to DNAinformation to protect the privacy of theirvolunteers. It is expected that the type of researchdone by Newfound Genomics can determine thepresence of genes that may contribute to certaindiseases. If insurance companies were able to accessthis kind of information, would it likely influencedecisions regarding the issuing of life insurancepolicies? If employers were aware that an employeeor a potential employee had the genetic make-upthat would likely lead to the development of adebilitating disease, would they make an unfavorabledecision regarding the future or continuedemployment based on this information? Asscientists continue to uncover the connectionbetween genes and disease in the hope of bettermedical treatment, it is conceivable that there areother agencies such as businesses that may use thisknowledge to further their own interests. This iswhy genomics companies are careful to ensure theconfidentiality of those who volunteer the use oftheir DNA to further the interest of science and willdevelop their own codes of ethical conduct toreassure volunteers and the public about the natureof their research.

The Business Community

Newfound Genomics must act as an instrument ofscience but also must operate in the business world. It is important that their research is properlyfinanced. The company is focusing on 3 lines ofbusiness; novel gene discovery, validation studies,and laboratory services. It is also important thatNewfound Genomics does not work in isolationfrom other genetic research companies and academicinstitutions. For example, Newfound Genomics hasdeveloped a partnership with Memorial Universityworking to build research capacity and joint researchinitiatives.

Once Newfound Genomics discovers genes that are

responsible for the development of certain diseasesthey will patent the use of this information for thedevelopment of drugs and diagnostic applications. Itis predicted that drugs developed from genomicsresearch will represent between 30-50% of globaldrug revenues by the year 2020.

Genetic companies are cautious regarding theownership of genetic information. If you arepatenting DNA, is it then the property of theindividual who volunteered the use of their DNAthat is being patented? Do genetic companies havethe right to patent DNA if it can be argued theproperty of the donor? If DNA is patented, then dothose who volunteered their DNA have a right toreap the economic benefits of the research? Imaginehow difficult it could be for genetic companies toexist as business institutions if all those who donatedtheir DNA were provided royalties based on thesuccess of the research. Furthermore, is it ethical forone to sell their DNA for research or for companiesto buy it?

Careers in Biotechnology

At present, Newfound Genomics is located in St.John’s and on the west coast of the provinceemploying about 10 people. Newfound Genomicscollaborates with Memorial University in thetraining of scientists, students and health careprofessionals for research. Their intention is toadvance the academic, intellectual, social andeconomic benefits for this province. It is expectedthat genetics research will be a fast growing industrydue to the unique genetic make-up of this provinceand therefore offer employment opportunities topeople in this province.

Conclusion

Newfound Genomics is an established and well-recognized biotechnology research company with anumber of research projects underway. Although itis too early for major results, any findings at presentare kept within the domain of the company. In fact,the company will not release any findings until it ispublished and undergone a peer review. This isbecause this information is considered “intellectualproperty” and it must remain private so thatNewfound Genomics can reap the academic and

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financial benefits of their work. It will be interestingto see the extent of the development ofbiotechnology and genetics research in our provinceand to anticipate the benefits for Newfoundland andLabrador both economically and medically.

References

Lana Hays. Introduction to DNA Extractions. Available at:http://www.accessexcellence.org/AE/AEC/CC/DNA_extractions.html

Bullard, Chetty et al. (2003). Biology. McGraw-Hill Ryerson. Toronto

Newfound Genomics. Website available at:www.newfound-genomics.com

Government of Canada. Family Genes hold the Keyto Understanding Disease. Follow the Leader.

Sequenom SNP Genotyping Technology. Availableat: www.sequenom.com

To Know Ourselves. US Department of Energy,Office of Health and Environmental Research. Available at:www.ornl.gov/hgmis/publicat/tko/index.htm

Special thanks to Hilary Vavasour, RN, RSCN, SCMwho provided a tour of the facilities at NewfoundGenomics and answered many questions.

Special thanks to Lynette Peddle, BSc who explainedthe technological aspects of Newfound Genomics.

Questions

Understanding Concepts1. Outline the benefits, both medical and

economic, of genetics research in this province.

2. What is a founder population? How does itlend itself to genetics research?

3. Why are researchers looking for genetic markers?

4. What are some of the long term goals ofNewfound Genomics?

5. Why is it important to study genes in relation todisease?

6. What are some of the benefits offered toNewfound Genomics by their partnership withother biotechnology companies?

7. What are the benefits of using Affymetrix andMassARRAY technology ?

8. Give two reasons why Newfound Genomicsdoes not release the results of their research untilit is published.

Extensions1. Go to the website for Newfound Genomics

(www.newfound-genomics.com) and follow thelinks to “about us” and “Our Team”. Examinethe educational background and workexperience of the Newfound Genomics teammembers. Make a list of 15 items that describethe qualifications and work experience requiredto work in the field of biotechnology. Whatconclusions can you make about this list?

2. Why is it important that Newfound Genomicsassure their patient volunteers that access totheir DNA from outside groups will beprotected?

3. Consider the following issues:

1. Do you want to know if you will sufferfrom a genetic condition later in life?

2. Do employers have the right to know yourgenetic status? Insurance companies?

3. Who should have ownership of geneticinformation?

4. Research how you may carry out a DNAextraction using a DNA source such as onioncells, a blender, salt, detergent, meat tenderizerand ethanol. What is the reasoning behind theuse of each of the materials used in this type ofDNA extraction?

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APPENDIX C


Outcomes:1. Outline evidence and arguments pertaining to the origin, development, and diversity of living

organisms on Earth. (316-4)

2. Explain the role of evidence, theories and paradigms in the development of evolutionary knowledge. (114-2)

3. Explain how knowledge of evolution evolves as new evidence comes to light and as laws and theoriesare tested and subsequently restricted, revised or replaced. (115-7)

4. Construct arguments to support a decision or judgment, using examples and evidence and recognizingvarious perspectives. (118-6)

5. Identify new questions that arise from what was learned. (214-17)

6. Use library and electronic research tools to collect information on a given topic. (213-6)

Extraterrestrial Life: Myth or Reality

Introduction

Imagine if somewhere in our galaxy, or beyond,organisms resembling intelligent life existed. Whatif extraterrestrial beings, such as Vulcans andKlingon Warriors of Star Trek, actually roamedaround outer space? Many scientists believe that lifecould possibly exist on other planets. Exobiology, orAstrobiology, is a branch of biology that studies thepossibility of life beyond Earth. Support forExobiology can actually be found using ourknowledge of how life has formed and evolved onEarth. Since the last century, numerous expeditionshave been made and probes have been sent

throughout our solar system in search ofextraterrestrial life. On Earth, radio-communicationis used to send signals into outer space in the hopesof reaching intelligent life. Radio-telescopes are usedto detect signals from extraterrestrials. This moduleuses what is known about the origin and evolutionof life on Earth to examine the possibility ofextraterrestrial life. The Origin of Life on Earth

The Big Bang Theory attempts to explain how thesun and planets in our universe were formed. Itstates that at one time our entire universe wascompressed into one atomic nucleus. Between 10-12 billion years ago an extraordinary explosion,trillions of degrees in temperature, blew apart theuniverse and it has been expanding ever since. Swirling clouds of dust condensed in the center ofour solar system to form the sun and swirling cloudsof dust and ice that orbited the sun came together,through gravity, to form the planets.

Earth probably formed about 4.5 billion years ago. At first, the atmosphere probably containedhydrogen gas. Later, volcanoes likely created anatmosphere that was made up of carbon monoxide,carbon dioxide, nitrogen, water vapour and possiblymethane and ammonia. Oxygen was not present in

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this atmosphere. It is important to consider thisbecause oxygen is considered to be an oxidizingagent that would disrupt chemical bonds. Thiswould prevent the formation of organic moleculesand, therefore, life as we know it.

In the 1920’s Haldane-Oparin hypothesized thatinorganic molecules can be used to make organicmolecules. They predicted that the components ofEarth’s early atmosphere could spontaneouslydevelop into organic compounds in the presence ofan energy source. Gases containing hydrogen,ammonia, methane and water vapour condensed toform pools on Earth’s surface known as primordialsoup. This mixture spontaneously produced organiccompounds when it was exposed to lightning andultraviolet radiation. These organic compoundsevolved over a long period of time to produce earlylife forms.

Further support for the Haldane-Oparin hypothesis,was provided by experiments of Miller and Urey in1953. Miller and Urey designed an apparatus thatcombined methane, ammonia, water vapour andhydrogen. They exposed these gases to an energysource that simulated lightning. They discoveredthat urea, amino acids and other organic compoundswere produced.

As a result of the work done by these scientists, itwas believed that the atmosphere is composed ofgases that could produce organic compounds. Thesegases are carbon dioxide, nitrogen, water vapour,and small amounts of hydrogen and carbonmonoxide. It was also believed that submergedvolcanoes and deep sea vents played a greater role inchemical reactions than lightning and UV radiation.In fact, one of the earliest life forms on earth areArchae bacteria found in hot springs, nourished bythe thermal vents of the Earth’s molten core.

Scientists believe that early life forms originatedfrom small organic molecules called monomers. Organic molecules then advanced to polymers suchas nucleic acids and proteins. It has been found thatclay can be used to polymerize reactions in whichmonomers can be joined into polymers. Scientistssuggest that monomers may have splashed from theoceans onto lava or other hot rocks, bondedelectrically to the rocks and then polymerized

through catalysts such as iron and zinc in the rocks.Monomers and polymers may have formedaggregates and developed forms of heredity andreproduction.

The first organisms probably came into being about4.1 billion years ago when Earth’s crust firstsolidified. Evidence of ancient prokaryotic fossilscalled stromatolites dates back to 3.5 billion yearsago. The stromatolites were likely photosyntheticbut heterotrophic life forms probably existed 4billion years ago. Earth would have required areducing atmosphere as opposed to an oxidizingatmosphere (which would have had existed at thetime of the photosynthetic stromatolites). Areducing atmosphere would add electrons tomolecules, thereby enabling simple molecules toform more complex molecules. Eventually, thesecomplex molecules became enclosed in membranesand the first organisms appeared.

Another theory, the Panspermia theory, explainedthat life originated elsewhere in the universe andsomehow found its way to Earth by intelligentbeings or by chance, such as by meteorites. The factthat rocks have traveled from Mars to Earth lendssupport to this theory. It is also known thatmicroorganisms can remain dormant for a longperiod of time and survive under space conditions.Therefore, it seems possible that microorganismsfrom Mars or from meteors could have reachedEarth and survived.

Based on these theories, scientists have beenexploring space for possible clues to the existence oflife. They have been looking for an atmospheresimilar to Earth’s early atmosphere. They are alsolooking for water, organic molecules, and an energysource such as the sun or volcanoes.

Extreme Environments on Earth

Life was not believed to have existed in extremeenvironments until recent years. These extremeenvironments include temperatures below zero andtemperatures of near boiling. They include milesabove in the atmosphere and miles beneath Earth’ssurface. Spores can hibernate for centuries andflourish when water reenters the environment. Organisms can live in extremes of pressure, salinity,

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acidity and radiation. Organisms that live inextreme environments are known as extremophiles.

The presence of extremophiles on Earth indicatesthat life can exist on the icy planets and hot planets.Extremophiles have been found under thousands ofmeters of ice in Antarctica in conditions believed tothe similar to Jupiter’s moon Europa. Extremophiles are common in hot ocean vents and itis believed that these bacteria may be the first lifeforms on Earth. Scientists believe that planetsundergoing volcanic activity in the presence of watercould foster similar life forms as those found onEarth near the hot ocean vents. Extremophiles havealso been found living in pockets of water severalkilometers below Earth’s surface. They usehydrogen gas to survive, formed by the splitting of water in the presence of uranium. Scientists believethat it is possible to find this kind of life form onMars since water and uranium are present on thisplanet.

Scientists hope to better understand the origin of lifeon Earth and how life might originate on otherplanets. They have been exploring places on Earththat resemble the conditions of Early earth when lifebegan. These environments include the ocean floor,the surface of hot volcanic springs and tidal pools. Ifthese conditions that are believed to have producedlife on earth exist elsewhere in the universe, then lifemay exist elsewhere in the universe. Scientists arelooking for planets and moons that may have moltencores and oceans. Sunlight is not always consideredessential since it is not necessary for chemicalreactions (chemosynthesis) if geologic activity ispresent.

The Search for Life Beyond Earth

Scientists are aware that the elements found onEarth are the same that exist throughout theuniverse. These elements are believed to have beenformed by exploding stars. Therefore, it isreasonable to assume that the carbon in our bodies,the iron in our blood, and the calcium in our bonescame from processes that took place in space.

As mentioned earlier, scientists haven been exploringthe universe for evidence of life by looking for threemain components that could support life: an energy

source, water and organic molecules. Organicmolecules have been found on other planets. Comets have been shown to contain water andorganic matter. Volcanoes on Earth and otherplanets can provide energy for life, as well as, watervapour and organic compounds. The icy surfaces ofmoons and planets also suggests that liquid watercould have existed or presently exists to sustain life.

Life from Earth has been shown to survive under theconditions of the moon. Bacteria that were accidentlytransported to the moon by a spacecraft survived onthe moon. This suggests that if life from Earth couldsurvive on the moon, then perhaps it could haveevolved and survived elsewhere in the universe.

The habitable zone in our solar system is the region inwhich scientists believe life may be supported. It wasonce believed to be between the planets of Venus andMars. This is because they are close enough to the Sunfor the solar energy to drive chemical reactions but notso close that the energy of the Sun would destroyorganic molecules or evaporate water from the surfaceof these planets. Scientists have expanded thehabitable zone since the gravitational pull of largerplanets can create enough energy to heat the cores oforbiting moons. As a result, there are several planetsand moons that could be habitable.

Venus: Numerous space missions have been sentover the years to Venus from the US and the formerSoviet Union. The Venera probes from the Sovietsin 1966 to 1982found that Venuswas dry and hot withvery little oxygen. The heat was sointense that theprobes weredestroyed after a halfhour of collectingdata. It is believedthat Venus was moretemperate at onetime but that somekind of catastrophe created a greenhouse effect thattrapped heat within the atmosphere. Venus’s terrainconsists of gently rolling plains with some broaddepressions and low rising mountains. Much ofVenus is covered by lava flows and some active

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volcanoes still exist. It is believed that Venus oncehad large amounts of water. Now, rain falls ascarbon dioxide and sulfur. The atmosphere is madeup of mainly carbon dioxide and thick layers ofsulfuric acid. Lightning strikes at a rate of more that10 times per second. There are low amounts ofwater vapor and oxygen. Mars: There have been numerous expeditions toMars in search of life. NASA Viking probes in 1976examined soil from the surface of Mars to look forsigns of life. No life was found but some chemicalreactions were evident in the soil. Dry river bedswere also found to indicate that there was once wateron the surface. This means that the atmosphere wasmore dense at one time and may have supported life.Polar ice caps on Mars grow and recede with theseasons. The landscape of Mars consists of plains,canyons, mountains, volcanoes, craters and dry riverbeds. There is presently a thin atmospherecomposed of carbon dioxide, nitrogen, argon andsmall amounts of oxygen and water. It is believedthat a catastrophic event must have occurred about3.5 billion years ago. The atmosphere thinned outand the ozone layer that may have existed collapsed. The planet was exposed to harmful UV rays and theriver beds either evaporated or froze into the ground. Mars meteorites found in Antarctica may containpossible fossils. This has created serious debateamong scientists. Some believe that life once existedon Mars and that we may one day find a rich fossil.

Europa: Europa is one the moons that orbit Jupiter. Scientists are considering the possibility that life mayexist on Europa because they have found evidence tosupport the existence of oceans beneath its icysurface. The Galileo space probe found the icylandscape was fractured and suggests that somethingmust be constantly fracturing and replacing the icesuch as an ocean beneath. The lack of craters alsoindicates that the icy surface must constantly bereplaced. Scientists are speculating that life couldexist in this ocean. The ocean may be warmed byEuropa’s molten core and may contain deep seavents that support life similar to Earth. The surfaceof Europa is relatively smooth with very few craters.The gravitational pull of Jupiter could create enoughheat to maintain liquid water underneath Europa’aicy surface. The atmosphere is composed solely of

oxygen. It is believed that this oxygen is notproduced biologically.

Titan: Titan is Saturn’s largest moon and ischaracterized by an impenetrably disease, thick,clouded atmosphere. Its lower atmosphere iscomposed primarily of nitrogen, with low amountsof argon and methane. Its upper atmospherecontains high amounts of methane formed from thetrace amounts of organic compounds, known asliquid hydrocarbon, in the lower atmosphere. It isbelieved that there are large lakes on the surface ofTitan containing these liquid hydrocarbons and thatthese conditions are similar to those of theprimordial Earth when terrestrial life originated. Pictures from the Hubble telescope indicate thatthere may be land masses similar to continents. Probes should reach Titan in 2004 to determine theaccuracy of these pictures. In 1979, the Pioneer 11spacecraft determined that the temperature was toocold to support life. Since then the discovery ofextremophiles on Earth suggest that this may not bethe case.

In 1998, the European Space Agency's InfraredSpace Observatory (ISO) discovered water vapor inthe atmosphere of Titan. The distance from the sunwould indicate that the surface would be too cold tosupport liquid waterbut scientistsspeculate that it ispossible that cometsor asteroids strikingthe surface couldmaintain water in itsliquid state for up to1000 years.

Tagish LakeMeteorite: Fragments of a meteorite fell to Earth in 1999 inTagish Lake of the Yukon territory. Thesefragments contained organic blobs similar to thosecreated in laboratories attempting to simulate life. Itis possible that Earth was provided with theseorganic globules from meteorites throughout history,including when life first began to form. Thismeteorite originated from the outer asteroid belt andcould have easily landed on Jupiter and Europa.

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This discovery has added to the debate over thePanspermia theory.

Conclusion

Many scientists believe that intelligent life forms donot exist beyond Earth. More scientists are likely toagree that microscopic life is common in our galaxy. However, many feel that our search among the starsfor signs of life is much like the voyage ofColumbus. We will never know whether life existselsewhere unless we continue our exploration of theuniverse. “...Our mission is to explore strange newworlds; to seek out new life and new civilizations; toboldly go where no man has gone before...”

References

Astrobiology101:Exploring the Living Universe. Available at:www.astrobiology.com/adastra/astrobiology101.html.Bullard, Chetty et al. (2003). Biology. McGraw-Hill Ryerson. Toronto

Cambell, Michell and Reece. (2000). Biology:Concepts and Connections, 3rd ed. Addison WesleyLongman, Inc. Don Mills, Ontrario.

Clarke, Tom. (2002). Goldmine yeilds clues forLifeon Mars. Available at:www.nature.com/nsu_pf/021209.021209-1.html.

Life Beyond Earth. A Film by Timothy Ferris. PBSDVD Video. A production of KCTS/SEATTLEwith LARK INTERNATIONAL in association withPBS and DEVILLIER DONEGANENTERPRISES.

Http://science.nasa.gov/newhome/headlines/astO/sep98-1.htm

Life Beyond Earth. Available at:www.pbs.org/lifebeyondearth/

Stenger, Richard (2002). Meteorite ‘ready-madehome’ for life. Available at:http://www.cnn.com/2002/TECH/space/12/24/tagish.meteorite/index.html

Questions

Understanding Concepts1 Discuss the significance of the work done by

Haldane, Oparin, Miller, and Urey regardingthe beginning of life on Earth.

2. What features are scientists exploring on otherplanets that may lead to the formation andexistence of life?

3. What types of evidence have been found byscientists to suggest life can exist beyond Earth?

4. Describe five types of extremophiles found onEarth. Explain why scientists believe they maybe found elsewhere in the universe.

5. What evidence suggests that life could exist onVenus, Mars, Europa, and Titan?

Extensions:1. Enter the following website:

www.pbs.org/lifebeyondearth/resources/teacher.html. Do the activity entiltled AlienCreatures: Extra terrestrial and TerrestrialOddities. Use what you know about evolutionand adaptation to create your own alien creaturesuited to live according to the conditions onanother planet.

2. Enter the following website:www.pbs.org/lifebeyondearth/resources/teacher.html. Do the activity entiltled TheHabitable Zone: A Europa Probe. Design a probeto travel to Europa that would have to considerthe conditions of the planet. This probe wouldsearch for signs of life which means that youwould have to consider how to identify lifeoutside of Earth.

3. Determine the signs of life that researchersshould be exploring when looking for lifebeyond Earth. Consider if these signs of lifeshould be the same as organisms on Earth.

4. Enter the following website:www.pbs.org/lifebeyondearth/listening/drake.html. Use the Drake Equation to calculatethe possibility that life exists beyond Earth. Discuss how you feel about the accuracy of thisformula.

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5. Cassini Saturn Orbiter and Huygens Titan Probewill reach Titan in the summer of 2004. Research their findings and explore if theseresults could support the existence of life onTitan.

6. Debate whether or not you feel life could existbeyond Earth.

APPENDIX C


Drugs and HomeostasisAnswers

1. Understanding Concepts

Clinical Depression Bipolar Disorder Schizophrenia

Neurotransmitters SerotoninDopamineNoradrenaline

- Not yet known- Possibly noradrenaline- Research on web

Dopamine

Imbalance Too much of the above ortoo much neurotransmitterbroken down by enzymes

High levels of neuradrenicactivity

- excessive dopamine activity

- excess in dopamine receptors

Treatments MAOI’sSSRI’sTricyclic compounds

Lithium carbonate Chlorpromozine

Side Effects MAOI’s - Heat failure(high blood pressure)

SSRI’s - Nausca(headache, insomnia,anxiety)

Tricyclics - Heat failure(lethal at low dosage)

Toxic at high levels:diarrhea, nausea, handtremors, blurred vision,confusion, swelling in thelower extremities

- Parkinson’s like symptoms

- abnormal movements- extreme pacing- dry mouth, constipation,

low blood pressure

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2.

Effect onNeural Pathways

Short Term Effects Long Term Effects

Alcohol Increasing GABAmodifies effects ofglutamine

- stomach and intestinalproblems

- blurred vision- slurred speech- poor muscle

coordination- lack of rational

judgment

- short term memoryloss

- liver disease- heat disease- ulcers

Marijuana Binds to CBI receptors - euphoria- blocking of pain- frustration- confusion- hallucination- anxiety- depression, etc.

- lung cancer, etc.- impaired speech- memory loss- insomnia

Cocaine Release ofnorepinephrinedopamine and serotonininterferes with the re-uptake of these as well

Euphoria thendepression

- dopamine reductioncausing cocainecravings

- mental impairment- convulsions- hallucinations- stroke, heart attack- death

Heroin Binds to ophioidreceptors in the brain

- euphoria- trance-like state- depressed, respiration

- collapsed veins- infections in heat

values- liver disease

RohypnolTM Enhances the action ofGABA

- sedation- blackouts- respiratory distress

- amnesia- highly addictive- death- severe withdraw

Ecstasy - damages serotoninmodern cells

- inhibits serotoninproductions andincreasesnorepinephrine

- increased heat rate- increased blood

pressure- dilation of pupils, etc.

- brain damage- respiratory failure- cardiovascular collapse

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3. Designer Drugs are produce in non-certified labs with little “qualify” control. No way to exactlydetermine what is in drug.

4.

Neural Pathway Short Term Long Term

Opioids Attach to opioidreceptors

- euphoria - physical dependaddiction

CNS Depressants Affect GABA - drowsy - build tolerance- require large doses

Stimulants Increase amounts ofneurotransmitters

- increase blood pressure- heart rate

vasoconstriction- increase blood glucose- open respiration

pathways

- create irregular heartbeat

- high body temperature- risk of cardiovascular- risk of lethal seizures

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Drugs and HomeostasisAnswers

1. Extensions

Pros

- block pain- reduce nausea- stimulate appetite

Cons

- gateway to more serious drugs- memory loss- harms lungs

2. Some patients would rather use drug treatments to help alleviate the problems of the mental illness andlead “normal live”. Some would rather not use these drugs because they have concerns over their side-effects.

MMAD inhibitors and tricyclic compounds have an increased risk of heart disease. SSRI’s can causeinsomnia and anxiety

Lithium can affect thyroid and kidney function. Other side effects include hand tremor and confusion. Chlorpromazine has a side effect similar to Parkinson’s. Other side effects include abnormal body andface movements and extreme pacing.

3. For Legalization Against

- use harmful than alcohol - addiction and health concerns- better regulation and taxation - could be the gateway to more dangerous drugs- prohibition supports organized crime - if legalized, more teens would abuse drugs- save money in law enforcement

4. Students should recognize that there is a biochemical basis of mental disorder. If chemical imbalancescause mental illness, it is not possible to control the production or action of these neurotransmitters. Thus, mental illness is not a figment of ones imagination nor can a person with mental illness controltheir thoughts.

APPENDIX C


Stem Cell ResearchAnswers

1. Embryological Stem Cells

Benefits

- have been show to differentiate into any typeof specialized cells.

- can be cultured in large numbers

Risks

- possible rejection- stem cells could contain viruses or diseases

that are transmitted to the patient- can lead to the

Adult Stem Cells

Benefits

- will not reject own stem cells- no need for immunosuppressants- avoid the ethical issues associated with

embryo logical tem cells

Risks

- more research is necessary to determine howadult stem cells can differentiate

- difficult to final in mature issues- techniques not developed to culture then in

large numbers

2. Sources of Embryological Stem Cells

- inner cell mass of the blastocyst 4 to 5 days after fertilization- 5 to 10 week old fetus

Source of Adult Stem Cells

- bone marrow, skin, liver, peripheral blood, blood vessels, muscle, brain

3. 1) ability to divide and renew themselves for a long period of time

2) unspecialized

3) ability to differentiate into specialized cells

4. - in specialized cells, certain genes are “turned on” and other genes are “burned off”- certain genes found within stem cells produce internal signals that guide cell differentiation- chemical secreted by other cells, externally guide cell differentiation

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5. - changing chemical composition of medium- altering surface of culture dish- modifying cells by inserting genes

6. Cell-based Therapies

- specialized cells in the human body that have been damaged through injury or disease could bereplaced by stem cells that can be induced to differentiate into the damaged cell

7. Therapeutic Cloning

- genetic material from transplant recipient is transferred to an egg cell- egg cell is stimulated to divide to produce stem cells

8. - transfer stem cells from inner cell mass to plastic laboratory culture dish- culture dish contains a nutrient broth and the inner surface is coated with an feeder layer. Feeder

layer provides cells with a sticky layer for them to adhere and also releases nutrients- cells will divide. When they overcrowd, they are plated to other dishes

APPENDIX C


Genetics Research in Newfoundland and LabradorAnswers

1. Benefits of Genetics Research

Economic ! develop patents! provision of royalties! career training

Medical ! improved pharmaceuticals! better family “planning”! determination of cause: better treatment options

2. Founder Population

- original inhabitants of area. Source of genetic material for future generations

Lends itself to genetic research as you have a “pure” line with which to trace trait inheritance. Creates abetter research environment with fewer complications.

3. Researchers are looking for genetic markers so as to establish a genotype. This could allow for linking ofgenotypes to traits.

4. Long term goals of Newfound Genomics are:

1) identify SNP’s related to disease

2) work in concept with pharmaceutical companies to design better treatments

5. To map the gene sequence that contribute to disease so that better treatments can be designed anddeveloped.

6. Benefits ! outside revenue sources! shared expertise

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7. Benefits Include

Affymetrix ! general scan of genome! gene expression studies

MassARRAY ! more specific! compare a greater number of parameters for experimental work

8. 2 Reasons

1) need peer review

2) information is “intellectual property” with academic and financial benefit

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Extraterrestrial Life: Myth or RealityAnswers

1. Haldane-Oparin ! inorganic molecules to organic molecules i.e. early atmosphere of H2, NH3,CH4, and H20 + energy = organic compounds

Miller-Urey ! used Haldane-Oparin ideas to perform experiments to replicate early organiccompound production

2. Three Main Components

1) energy source

2) water

3) organic molecules

3. - extremophiles on earth- bacteria back from the moon- volcanic areas of earth- icy surfaces of moons and meteorites- tagish lake meteorites

4. Extremophiles: temppressuresalinityradiationacidity

- Extremophiles capable of living in extremes of temperature could life on extremely hot or cold planets(comets)

- those capable of living near radiation could live on radioactive meteorites and planets

5. Venus - 02 in atmosphere- more temperate at one time- once may have had large amounts of H20- greenhouse effect

Mars - chemical reactions evident on soil- dry river beds indicate life- seasons / ice caps- thin atmosphere- mars meteorites may contain fossils

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Europa - oceans beneath ice- may contain deep sea vents like those on earth- 02 atmosphere

Titan - thick atmosphere- believed to have large lakes- water vapour in atmosphere

6. Extensions

YES

Similar conditions exists elsewhere that aresimilar to primitive earth

NO

- may defer to divine intervention- odds not in favour