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Biomedical subjects

H Guski

Publications and source records attributed to H Guski.

At least 91 records · Page 5Linked to original sources
PubMed1986

[Clinical significance of histologic mastopathy diagnosis using quantitative procedures].

Examinations were applied to 101 patients with simple fibrocystic mastopathy (15 cases), proliferative mastopathy (52 cases), invasive ductal carcinoma in concomitance with mastopathy (21 cases), and normal mammary glands (13 probands) in a prospective clinico-morphological pilot study. The use of Robotron A 6471/AMBA-R, a system for automated microscopic image analysis, together with improved methods, has opened up new possibilities for early detection of precancerous changes of the mammary gland. Significant differences were identified between the two clinically relevant groups, II and III, of proliferative mastopathy by quantitative analysis of ductal epithelial proliferations through reproducible measuring data were obtained together with highly distinctive karyometric and histometric parameters. Multiparametrical analysis also provided suggestions to the effect that cases of proliferative mastopathy III, probably, break down into two groups with presumedly differentiated carcinoma risks. Hence, it may well be possible that the biological importance of atypical ductal epithelial proliferations differs from case to case.

Adult↗
PubMed1986

[Morphometric studies of the vegetative nervous system in sudden cardiac death].

Histochemical investigation of the adrenergic cardiac nerves was undertaken for 101 victims of sudden cardiac death. In addition, the cervicothoracic ganglia of 12 persons between ages 40 and 60 who had died a sudden death were studied electron microscopically. Use of morphometric methods demonstrated that there was a significant reduction in the volume density of adrenergic nerve plexuses with focal depletion in the right and left ventricular walls and degenerative changes in the autonomic ganglia. In the sympathetic neurons, along with dilatation of the endoplasmic reticulum, damage to the mitochondrial inner membranes and the emergence of osmiophilic, dense bodies in the mitochondria were recorded. Morphometric analysis revealed a significant increase of the volume density of the mitochondria, which reflected predominantly the enlargement of these cell organelles. It is concluded that these degenerative changes in the vegetative nervous system have a possibly causal relevance to the occurrence of sudden cardiac death.

Adult↗
PubMed1986

[Grading of urinary bladder tumors by automated microscopic image analysis].

Studies were undertaken on biopsies from urinary bladder papillomas and urothelial carcinomas of different grades (G1-G3) along with normal urinary bladder mucosa from a total of 145 patients. They were performed by use of automated microscopic image analysis (system Robotron A 6471; software AMBA/R) and resulted in making objective the tumor grading and lead to the detection of both papillomas and G1-carcinomas with high proliferating activity. In addition, we were able to separate the G2-carcinomas into two groups which probably show different biological behaviour. They cannot be discriminated by conventional morphological methods but their existence is consistent with clinical observations.

Aged↗
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↗
PubMed1984

[Karyometric studies of meningiomas].

Of a total of 195 bioptically diagnosed meningiomas of the Pathological Institute of the Humboldt University Berlin of the period of 1963 to 1976, 21 meningiomas (5 endotheliomatous, fibromatous and angiomatous meningiomas, 6 malignant meningiomas) were selected and 10 parameters evaluated for a comparative morphometric analysis. The evaluated parameters describe quantitatively the numerical density of the nucleus, the size of the nucleus, the size of the nucleoli and the nucleus/plasma relation. Malignant meningiomas are distinguished from benign meningiomas by a significant enlargement of their nuclei, of the nucleoli and the nucleus/plasma relation. On the other hand, the numerical density of the nuclei can only be used conditionally for the discrimination of malignant and benign meningiomas; the numerical density of the nuclei of the malignant meningiomas is lower than that of the endotheliomatous meningiomas and larger than that of the fibromatous and angiomatous meningiomas. The article demonstrates the possibility to obtain a differentiation of groups of typical cases of malignant and benign meningiomas on the basis of morphometrical data. Conventional morphometry is a time consuming process and thus not suitable for routine work. In connection with automatic image evaluation procedures (automated microscopic image analysis, cytophotometry) ways are opened up for a wider application of morphometry and densitometry and a classification of individual tumour preparations.

Brain↗
PubMed1982

The effect of exercise on cell proliferation in the non-ischemic heart after myocardial infarction.

The influence of physical training (180 hours, 3 hours per day) on the 3H-thymidine incorporation into the connective tissue cell nuclei and into the myocardial cell nuclei of the non-ischemic heart after myocardial infarction was studied in 38 untrained and trained male Wistar rats. In the connective tissue cells physical training caused a clearly reduced proliferative activity which could be demonstrated until the seventh day after infarction. Besides, in trained animals there was a decreased DNA turnover of the heart muscle cells during the first few days following myocardial infarction. Probably, the observed changes are an expression of the different adaptability of the untrained and trained non-ischemic myocardium.

Animals↗
PubMed1981

[Contribution to problems of the adaptation concept in pathology using the heart as an example (author's transl)].

The paper represents a contribution to the problems associated with the adaptation concept used in biology and medicine for which there does not yet exist an exact and generally accepted definition. Several aspects of the adaptation concept as it is applied in pathology (adaptation and disease, adaptation on the cellular level, adaptation and and optimation, systemic and local adaptation) are illustrated by means of the adaption of the heart to physiological and pathological condition, with particular attention being paid to questions of cellular adaptation. Finally, it is emphasized that knowledge of the structural and functional changes underlying the adaptation of the organism is of great importance to the prevention of diseases.

Adaptation, Physiological↗
PubMed1980

[Ultrastructural-morphometric characterization of adaptive and compensatory myocardial changes using heart enlargement as an example].

A morphometric analysis of the heart muscle cell shows significant differences in the reaction of different cellular structures in different experimental stress models of the myocardium (swimming exercise and ligature infarction) in the rat. For instance, the number of mitochondria is 44% higher only 2 days after infarction than after 45 h of swimming exercise over a period of 4 weeks. The mitochondria/myofibrils ratio is higher than in the case of training. But later on in the course of the experiment the number of mitochondria and their membrane surface density diminishes compared with training. The differences in the rate of formation and in the kind and intensity of the changes are probably attributable to different adaptive mechanisms by means of which the heart reacts to acute and chronic loads.

Adaptation, Physiological↗
PubMed1980

Morphometric analysis of myocardial mitochondria in rats during adaptation to exercise.

Comparative morphometric studies of the mitochondria of muscle cells and of interstitial cells of rat hearts were carried out in order to obtain more information about changes in mitochondrial parameters during adaptation of the myocardium to physical training of different durations (45, 180, 360 hours of swimming) and intensities. On the basis of the results the authors conclude that the mitochondrial biogenesis of heart muscle cells occurs in dependence on the intensity of training at two morphometrically different stages. Some parameters of the mitochondria of the interstitial cells reacted in a manner similar to that of the muscle cells, but opposite reactions were also observed. The biogenesis of mitochondria and the absence of a decrease in the mitochondria/myofibrils ratio in muscle cells may be regarded as an improvement in cell metabolism in the training-induced hypertrophy of the rat heart.

Adaptation, Physiological↗
PubMed1980

[Comparative quantitative-cytochemical and ultrastructura-morphometric studies for the characterization of the rat heart in experimental myocardial infarct].

Some oxidative enzymes of undamaged sites of the left ventricle were examined with the aid of ultrastructural morphometric and quantified cytochemical methods 1, 2, 7 and 14 days after the ligature of the descending branch of the left coronary artery. A comparison of the ultrastrastructural morphometric data with the densitometric data showed that increases in the activities of some oxidative enzymes are accompanied by enlargements of the mitochondria.

Animals↗
PubMed1980

[Multivariable EDV-program for light and electron microscopic morphometry].

A computer program for morphometry and stereology in which conventional morphometric and stereological data acquisition (direct linear measurement, point counting technique) is used and which is designed for variable application of conventional and electron microscopy is presented. There are several program variants and magnification stages each designed for a different structural level. There is fixed number of essential subcellular, cellular and extracellular structures for different kinds of tissue (myocardial, liver and connective tissue), but this number can be enlarged with each stage of magnification and for each measured parameter by reserving free places for evaluating additional structures. Thanks to the extended program and to the fact that these free places are interchangeable, the program can be used independently of the kind of tissue examined and of the kind of morphological information sought. The program structure is realized by means of a master control and 4 external subprograms. The statistical analysis of the morphometric stereological parameters is calculated by image, case by case or group by group. The mean values of the calculated primary and secondary parameters, the standard errors and the standard error/mean value ratio are printed out. All common stereological parameters and the essential cellular and extracellular structures of different kinds of tissue are described in quantitative terms with the aid of the program.

Computers↗
PubMed1980

[Experimental coronary atherosclerosis and ischemic heart disease (author's transl)].

Experimental coronary atherosclerosis was produced by application of 2 g cholesterol per day per animal to 20 rabbits for different periods (12, 16 and 20 weeks); 5 animals were used as controls. Histological sections of the basal part of the left heart ventricle were investigated morphometrically. The frequency of the atheromatosis, their distribution, and the extension of the average narrowing of the vessels were determined separately for subepicardial and intramural coronary arteries. Contrasting to the subepicardial arteries, the intramural coronary arteries showed severe lesions of the vessel wall with narrowing and obturating processes. Thereby, a time-dependent progression of the frequency and severity of atheromatosis was noted. The narrowing of the lumen as regards to the subepicardial coronary arteries did not differ significantly from controls. The intramural coronary arteries, on the other hand, showed a progressive and of the lumen at all periods of investigation significant narrowing.

Animals↗