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Biomedical subjects

K Wenzelides

Publications and source records attributed to K Wenzelides.

33 records · Page 2Linked to original sources
PubMed1985

[Regeneration of liver parenchyma and sinusoidal cells following partial hepatectomy].

Partial hepatectomy (30 percent of the liver weight) was performed in 225 female Wistar rats, ages 6 weeks, 6 and 9 months. The animals were sacrificed in intervals between 4 hours and 21 d after the operation. The automated microscopic image analysis after Simon et al. (1984) and histoautoradiography were utilized for evaluation of liver cell regeneration. Despite measurement of more than 1,000 cells per animal we were not able to confirm enlargement of hepatocytes as the first reaction to partial hepatectomy The number of liver cells per unit area increased whereas sinusoidal size remained rather constant, corresponding to a decrease in average cell size and in the standard deviation of cell area. The importance of binucleated hepatocytes in the process is emphasized. Measurement of the nucleoli and of the mean extinction values of liver cell nuclei as a measure of the DNA content did not provide any essentially new perspectives. The investigation did however emphasize the importance of the extent of the hepatic resection and the age of the experimental animals on the intensity and subsequent course of liver cell regeneration. Proliferation of the sinusoidal cells themselves after partial hepatectomy could not definitively be demonstrated to be age-dependent.

Age Factors↗
PubMed1981

[Determination of the relative RNA-content of liver cell nuclei with gallocyanin-chromealum-staining (author's transl)].

The relative RNA-content of liver cell nuclei from histological slides of rat liver was determined by automatical microscope picture analysis. The slides were stained with Gallocyanin-Chromealum. Extinction measurements are made before and after perchloracid extraction of RNA for the same slide. The changes of extinction measurements caused by the changes of slide thickness and of tissue inhomogeneity could be lowered using this method.

Animals↗
PubMed1981

Logical classifiers for image analysis in medicine.

A simple, intuitive procedure for the stepwise classification of objects in n-dimensional feature spaces is presented. Each classification step is based on a single feature decision and provides an optimal separation of the objects of only one class from the objects of all other classes. The algorithm of this procedure is implemented on a minicomputer of an image-analysis system. Testing of the classifiers on biomedical data (213 slides of diseased and normal liver tissue) yielded good results requiring few decisions and threshold parameters: 152 correct classifications, 16 incorrect classifications and 45 rejections.

Cell Nucleus↗
PubMed1980

[Quantitative morphological investigations in livers and liver tumors after taking contraceptives (author's transl)].

Since the introduction of the orally applicable contraceptive steroids repeated reports have been published on the occurrence of side effects largely manifesting in the liver. By means of morphometrical and densitometrical evaluation of histological slide preparations of livers damaged by contraceptives (biopsies, operation material), qualitative and quantitative transitions between the individual degrees of the lesion up to malign cell transformation were registered by automated microscope picture analysis. It appeared that this cell transformation, like similar as in experimental hepatocarcinogenesis, is gradual process. Among the most remarkable cytopathological features are changes of nuclear and nucleolar size and of the sinusoid area and of the number of Kupffer's cells. The latter are clearly increased in hepatosis caused by contraceptives as compared with normal livers, they are reduced in the hepatocellular adenoma, and reach a value near zero in the carcinoma.

Adult↗
PubMed1979

[Comparative, quantitative and morphological investigations (automatic image analysis--micromorphometric analysis) of myocardium of rat isoprenalin treatment (author's transl)].

The alterations of areas of myocardium of male rats (2, 4, and 6 months) are investigated after isoprenalin treatment (0.05 mg/kg body weight and day i.p. for 30 days). The investigations are carried out using automatic microscope picture analysis, morphometric point counting and resp. Both methods yield the same qualitative results: The effect of isoprenalin is dependent on age and yields for old rats (6 months) only very little morphometric alterations in the myocardium. The automatic microscope picture analysis is a very effective method of investigation (45 seconds/cross section).

Age Factors↗
PubMed1978

Determination of infarct size in rats with 86rubidium.

A quick method is presented which allows the determination of infarct sizes within hearts of experimental animals like rats. The method is based on the drop of 86Rb uptake in infarcted hearts, and has been compared with infarct sizes determined morphometrically. The standard deviation of this method is low (6.5%) because an internal standard in used (noninfarcted myocard - usually right ventricle tissue - has been used).

Animals↗
PubMed1976

[Learning and chronobiological regulation following experimental damage to the coronary-artery wall of albino rats].

Forty male albino rats were used to study the relationship between experimentally (concentrated hydrochloric acid) produced local structural changes of the coronary artery wall and central nervous information processing and chronobiological events, respectively. The alterations of the coronary arteries caused by this treatment did not produce infarction but initiated on the whole length of the arterial branch proliferative processes that are complete within 12 weeks following the intervention. Central nervous information processing and chronoregulatory processes showed, immediately after exposure to hydrochloric acid, pronounced malfunctions followed by a stage of hyperreactivity (4 weeks following the damage). At 8 weeks from the intervention, the parameters of information processing and chronobiological events of the CNS again equalled the control values. Since the central nervous functions were back to normal earlier than the structural alterations, the results are interpreted as reflecting CNS-controlled interactions between the complex of visceral afference and efference, the regulation of which is determined by the CNS after coronary damage in such a way as to restore the adaptational capacity of the organism by a predominance of sanogenetic processes.

Animals↗