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Chapter 8 Pregnancy Test

Bence-Jones Proteins17-Keto-Sterods

Professor A. S. Alhomida

Chapter 8 Pregnancy Test

Bence-Jones Proteins17-Keto-Sterods

Professor A. S. Alhomida

DisclaimerDisclaimer• The texts, tables, figures and images contained in this course

presentation (BCH 376) are not my own, they can be found on: • References supplied• Atlases or• The web

King Saud University

College of Science

Department of Biochemistry

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Relative Size of Human ConceptusRelative Size of Human Conceptus

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Maternal Fetal SystemMaternal Fetal System

PlacentaPlacenta1. Connects Fetus and

Mother2. Transports:

Nutrients & O2

Waste products & CO2 away from fetus.

3. Early Nutrition of Fetus Due to: Trophoblastic

digestion Absorption of

nutrients from endometrial deciduas

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Gestational HormonesGestational Hormones

1. Human chorionicgonadotropin (hCG)

2. Human chorionicsomatomammotropin (hCS; hPL)

3. Estrogens4. Progesterone

Ovulation Parturition

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Gestational Hormones, Cont’dGestational Hormones, Cont’d

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Human Chorionic Gonadotrophin (hCG)Human Chorionic Gonadotrophin (hCG)

• SecretionSecretion1. It is a glycoprotein hormone produced by the developing placenta

shortly after fertilization and the embryo attaches to the uterine lining and

2. It builds up rapidly in pregnant body in the first few days of pregnancy

• FunctionFunction1. Prevent involution2. Stimulate progesterone and estrogen secretion3. Prevent menstruation4. Promote endometrium growth5. Stimulate testosterone

• Production development of fetus male sex organs

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Placental EstrogenPlacental Estrogen

• SecretionSecretion1. Secreted by placental trophoblast

2. Androgen precursors from maternal and fetal adrenal glands

• FunctionFunction1. Uterus enlargement

2. Relaxation of pelvic ligaments – more limber for passage of fetus through birth canal

3. Breast enlargement

4. Growth of breast ductal tissue

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ProgesteroneProgesterone

• SecretionSecretion1. Secreted by corpus luteum and placenta2. Essential for pregnancy

• FunctionFunction1. Development of decidual cells in endometrium for fetal

nutrition2. Decrease contractility of uterus3. Prevent spontaneous abortions4. Ovum development prior to implantation5. Breast preparation for lactation

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• FunctionFunction1. It is a general metabolic hormone2. Partial development of maternal breasts3. Effect on metabolism

• Decreases maternal glucose usage for fetal usage• Promotes FFA release from maternal stores energy for fetus• Weak action on protein deposition; similar to GH

4. It is important for the nutrition of mother and fetus

Human Chorionic Human Chorionic Somatomammotropin (hCS)Somatomammotropin (hCS)

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Clinical and Biochemical Clinical and Biochemical Significance of hCGSignificance of hCG

1. Increased urinary excretion of hCG which occurs in early pregnancy (early as 10th day of gestation)

2. There are two different pregnancy tests:

• Biological Test (Aschein-Zondek test) has been replaced completely by:

• Immunological Test (home pregnancy test)

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Home Pregnancy TestHome Pregnancy Test

1. It is a colloidal gold/antibody complex based rapid chromatographic immunoassay for the detection of hCG in urine

2. hCG can be detected in urine as early as 7 days after conception

3. hCG concentrations peak at about 9-12 weeks into pregnancy4. The amount of hCG will vary greatly with gestational age and

between individuals 5. It detects the presences of hCG in urine specimen at the

sensitivity of low concentration

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1. The hCG Urine dipstick Test consists of a chromatographic absorbent device and an unique combination of monoclonal antibodies that selectively detect hCG in test samples with a high degree of sensitivity

2. Urine migrates through the absorbent area and along the test membrane

3. hCG present in the specimen is bound by antibody-gold conjugate forming an antibody-antigen complex

4. The complex is captured by anti-hCG antibody immobilized in the test zone (T) of the membrane forming a pink-rose band

Principle of Home Pregnancy TestPrinciple of Home Pregnancy Test

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5. In the absence of hCG, no line will form in the test zone (T)6. While the test line indicates the level of hCG present in the

sample7. Another gold conjugate is captured by the antibody

immobilized in the control zone (C) of the membrane producing pink-rose color band, regardless of the presence or absence of hCG in the sample

Principle of Home Pregnancy Test, Principle of Home Pregnancy Test, Cont’dCont’d

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Principle of Home Pregnancy TestPrinciple of Home Pregnancy Test

• CC: Control zone containing anti-hCG antibody to give pick-rose band

• TT: Test zone containing antibody-gold conjugate forming an antibody-antigen complex with urine hCG to form pick-rose band

• Negative ResultNegative Result: only one pick-rose band in C zone will appear

• Positive result: two pick-rose bands will form, one on C and other is on T zone

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Home Pregnancy Tests, Cont’dHome Pregnancy Tests, Cont’d

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Home Pregnancy Tests, Cont’dHome Pregnancy Tests, Cont’d

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Bence-Jones ProteinsBence-Jones Proteins

1. They represent either the kappa or lambda immunoglobulin light chains

2. They are most often associated with multiple myeloma (plasma cell cancer)

3. L chains are over produced by proliferating plasma cells and released into the blood without combining with H chains

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Bence-Jones Proteins, Cont’dBence-Jones Proteins, Cont’d

4. They excreted in urine because of their relatively small size

5. They are precipitated at 60 C and used for diagnosing multiple myeloma

6. Excretion of BJ proteins in large amounts causes the tubular cells to become degenerated because of high levels of BJ reabsorbed

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They comprise a group of steroid compounds which have a ketone at position 17

17-Ketosteroids

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17-Ketosteroids, Cont’d

• Assay for detection of 17-ketosteroid compounds

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17-Ketosteroids, Cont’d17-Ketosteroids, Cont’d

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THE ENDTHE END

Any questions?