P-H5-25 P-HS-26 THE CwAT]IoN OF BENIGN AND MALIam PW3S’I’A’i’E TB$UE BY MUL’-lW~~ATE ANALY’SIS OF ‘H MAGNE’i’IC RESONANCE SPECTRA SMI’H ICP,’ LEBOLDUS~2 BABNP,) LIlTMAN C,’ SOMORJAI RL.’ BBZABEHT’ ‘Institute fa Bicdiagnosties. National Research Council of Canada, %nnipeg Clinic,‘Manitoba Cancer Foundation, ‘University of Manitoba (Canada)

MFLDENCE OF .LQCAh4NESTHETIC ON DEFOHMAB~ITY oFBEiWBtiQoD~cI&LLs Ramstgsrhnm S’,Grebe It, K&IS Vi&, Fkger R, Rosi vglta Siigh$ebmid-ScMnbein H Biomedkai Bngg. Dvn., ID, Ma&a@NDIA)’ Inst. of Physio. Klinikum der RWTH, Aachen (GER)

I!tqwe~ To explore the use of ‘H magnetic resonance spectroscopy (MRS), combined with multivariate analysis methods, in differentiating benign (BPH) from malignant prostate tissue. Methods: Prostate tissue (n = 82) from transmethml resection of the prostate and radical pmstatectomy were subjected to MRS and later to histopathological assessment. The spectra were partitioned Into a truining sef (33 BPH, 11 mmour) and a rest ser (31 BPH, 7 tumour) and were subjected to linear discriminant analysis. Results: An optimal set of 8 spectral regions was selected by our algorithm as being discriminatory. Classilkation accuracies were 98% for the training set and 95% for the test set. Conclusion: ‘H MRS combined with multivariate snaly~is can be used reliably to distinguish between BPH and cancer of the prostate. We are now extending the method to in vivo studies.

Purpose:It is known that the medication used to induce anesthesia alters resting shape of red blood cells but their ability to deform to carry nutrients to microvessels is not well established. Aim of this study is to analyse the effect of local anesthetic on the deformability of human red blood cells in vitro.

Methods:Red blood cells suspended in desired concentrations of local anesthetic (Procaine) were made to pass through microfilters and the process was continwsly recorded using Filtrometer (MP4). Index of defbrmability was derived iiom the slopes of the microcomputer generated filtration curve.

Results:The defbrmabilty was found to decrease with incmase in concentration. Maximum decrease was 34% for (lO-*g/l) wherein significant shape changes were observed in microscope.

Conclusion: We conclude that local anesthetic decreases the deformability of red cells in addition to altering the shape and surface charge density. Further investigations are being carried out.

P-H527 P-H5-28

A METHOD TO DETERMINE THE DEFORMABILITY OF HUMAN BED BLOOD CELL MEMBRANES PLIEGER R; GREBE R. Biomedii System Amdysis Dvn.. Institute of Physiology, IGhikum der RWIH, Aachen (GERMANY)

PARELEcIllfC sPi!x2RDScOPY REICHLE C., KLGSGEN B., KOHLSMANN S., KRAMER K.

Purpose: A new method to measure the deformability of red cell membranes under well defined reproducible mechanical forces without the influence of undesirable chemical interactions is developed.

Methods: Red cell suspensions in physiological solutions, (e.g. plasma, buffer, but also drugs are possible) are filled in a specially designed centrilkge chamber. The cell membranes are deformed by centri&gaI force that can be varied by varying the rotational speed of the chamber. ‘Ibe comspondiig changes in the cell shape are observed indirectly by laser light diffiction.

Physics Dept., Free Uniwsity Bedin (GERMANY) Ialmddm The dielectric properties in biological materials are accessible by a low cost and easily transportable small device. Metbods: High resohttion parelectric spectroscopy is achieved by a newly developed microprobe in combination with a commercial network analyzer and an adequate software for measuring and analyzing. A low amp&ode rf wave is swept in a range (I-1OQQ)MHx and stapled fully hydrated lip Results: Relaxation curves are obtained for. both abso tion and dispersion. Inmtpmm&m modi! $ ed Debye’s,e uations revealed cont?tions of the headarotm an bound water molecules with

Results: Well defined, force dependant diEaction patterns are observed and are highly sensitive for small changes in the membrane shapes.

Conclusions: We conclude that this technique could be used as a precise and a supplementery tool for investigating the biophysical behavior of red cell membranes.

either one &t&t relaxation &quency or a weiahed distriintion accordim to the shell-like hydktion water structure. Di&nct activation energies could be attributed to both relaxation processes. Conclusion: In a complex system like biological membranes parelectricspectroscopy may be a&edasatoo!toaccesstheeffe+of~e

erently relaxmg drpoles. In m+aI dragnosis of even more comnlieated systems like whole ceils and cell aggregami ’ l&ionintermsof

7 ..normal” and ..abnonn “ behavior has aheadv been proved to be helpful.

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