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Biomedical subjects

H Krug

Publications and source records attributed to H Krug.

At least 19 recordsLinked to original sources
PubMed1992

A new simulation approach for the determination of the error of parameters of biological importance describing the growth of the Ehrlich ascites tumor of the mouse.

Some aspects of the growth of the Ehrlich ascites tumor of the mouse can be described by the logistic function. The parameters used are fitted to the experimental data in a nonlinear way. It is important to determine the error of these parameters of biological importance in order to discriminate between different consequences induced by various experimental situations by means of statistics. But often there is a gap between the data that are available and the stronger assumptions necessary for statistics. We propose a simulation approach which also works in a much larger range of similar situations to close this gap.

Animals↗
PubMed1991

[Degree of DNA ploidy and steroid hormone receptors as prognostic factors in endometrial carcinoma].

In a prospective investigation the concentration of DNA (ploidy) and of steroid hormone receptors (ER and PgR, resp.) were studied in endometrial carcinoma and related to each other, to established morphological prognostic criteria (stage, typing, grading, relative invasion of myometrium), and to the clinical progress of disease, respectively. The microscopic spectrophotometric analysis of DNA showed diploid main lines in 2/3 of investigated endometrial carcinoma. It could be demonstrated a relationship between heteroploidy, decreased mean concentrations of ER and PgR, unfavourable prognostic factors (stage II-IV, G3, myometrial invasion of greater than 2/3) and clinical progress of disease. The mean value of ER and PgR was higher in diploid carcinoma than in heteroploid ones. Significant differences were found both in the relation of the PgR concentration to different tumor stages (stage I vs. II-IV) and of the concentration to the different types of ploidy. Exceeding the histological differentiation, the determination of DNA and ER/PgR receptors can results in additional prognostic informations for a scientific proved, adjuvant or curative strategy of therapy after the operation.

Carcinoma↗
PubMed1991

[Cytophotometric studies for evaluating the prognosis in endometrial cancer].

This paper deals with a prospective cytophotometric study of specimens from 48 cases of primary endometrial carcinoma. The tumor material was obtained from the region of tumor invasion immediately after an operation and in 8 cases by fractional curettage after ultrasonographic localisation of the tumor. The specimens were air-dried and Feulgen stained. The cytophotometric examinations were performed with a scanning cytophotometer. A computer-assisted data registration and processing was carried out. The histological diagnosis of the tissue specimen and curettage specimen was established according to standardized criteria. 32 out of the 48 investigated cases of endometrial carcinoma were diploid. Observations conducted over a period of 12 months showed a partially significant correlation (u-test according to Mann and Whitney) between DNA-content and stage of the tumor (FIGO), histological grade of the tumor, relative depth of myometrial invasion as well as the clinical course. A differentiation based on the ploidy and the average relative DNA content (AE) in relation with typing is not possible. It was not possible to state the difference between average nuclear surface (F) and individual morphological variables. The average extinction, as a measure of the chromatin density, was determined for each specimen. A significant increase of the average extinction was established for carcinomas which infiltrated more than 2/3 of the uterine wall. Ploidy, average relative DNA content and average extinction provide an invaluable additional parameter in the assessment of the prognosis, post-operative therapy and aftercare of patients with endometrial carcinoma.

Adenocarcinoma↗
PubMed1979

[Interference microscopic determinations of dry mass of cell nuclei of normal and dysplastic epithelium, carcinoma in situ and cervical carcinoma cultivated in vitro (author's transl)].

Dry mass of cell nuclei was studied in 34 explant cultures of normal epithelium (8), persisting dysplasias (7), Ca in situ (9) and cervical carcinomas (10) by interference microscopic determination. Dysplasias, Ca in situ and carcinomas can be distinguished from normal epithelium by a significantly higher dry mass value. Such a difference does not exist between dysplasia and Ca in situ. The percentage of dispersion of the dry mass is significantly higher in carcinomas than in all other examined tissues. The biological meaning of these results is discussed. The interference microscopic determination of dry mass of the cell nuclei is a suitable parameter for the characterization of properties of cervical carcinomas and their intraepithelial prestages cultivated in vitro.

Carcinoma, Squamous Cell↗
PubMed1978

[Progression and regression of diet-induced arterial changes in the domestic pig].

Under atherogenic diet in the pig changes of the intima developed in predisposed places of the arteries which have close relations to the atherogenesis in man. 4 months after the end of a 4-month atherogenic diet no decisive regression of lipid infiltrates could be established in spontaneous thickenings of the intima, however, signs of a lipid mobilisation.

Animals↗
PubMed1978

[Pathways of intracellular cholesterol metabolism in a model study].

We had concluded from former own investigations that the cells in the arteriosclerotic plaque effect a change of the ester proportion of cholesterol. One of the possible mechanisms ible bond and from double unsaturated (linoleic acid) to higher unsaturated acids. Therefore we investigated by radioactive labelling of the fatty acid moity of cholesterol esters whether such desaturation reactions take place in the model experiment. For this purpose we implanted cholesterol stearate which was 14C-labelled in the proportion of fatty acid subcutaneously into the skin of a rat. We demonstrated radiohistochromatographically that after 7 to 14 days the fraction of the cholesterol esters with 1 double bond was additionally labelled. Other fractions were not labelled. From this results that the proportion of the saturated fatty acid of the cholesterol ester is actually desaturated, in which case the desaturation as we expect only goes to the fraction with one double bond, because the double unsaturated linoleic acid is not synthetized in vivo in the mamal.

Animals↗
PubMed1978

Histophysical and histochemical investigations on muscle arterioles in hypertensive arteriolosclerosis; an interference microscopical, polarization optical and histophotometrical study.

In 50 formol fixed biopsies from the m. quadriceps femoris normal and hypertensive arteriolosclerotic arterioles were characterized by quantitative histophysical and histochemical methods. The interference microscopical measurements showed a real increase of dry mass concentration in the pathologically changed vessels. Additional histophotometrical results are interpreted as an increase of proteins with higher isoelectric point (globulins, actomyosin). An augmentation of actomyosin is compatible with the medial hyperplasia demonstrated histologically. Likewise a positive correlation was found between the fibrin incorporation proved histochemically and the quantitatively evaluated protein reaction with Fast green; Glycosaminglycans do not carry weight quantitatively. The polarization optical measurements yielded an alteration of the submicroscopical structure in arteriolosclerosis. It consists in a diminution of the submicroscopical volum of gaps and in a diminished orientated dye binding of Congo red. Thereby the pathogenesis of hypertensive arteriolosclerosis of skeleton muscle is above all characterized by an increase of heterogeneous proteins (blood plasma proteins, actomyosin) in the arteriolar wall, leading to a diminution of the submicroscopical volume of gaps and to an elevation of the dry mass concentration.

Arteries↗
PubMed1978

[Pulse cytophotometrical investigations about the resistance of DNA against acid hydrolysis influenced by ageing and cortisol (author's transl)].

The resistance of nuclear chromatin against acid hydrolysis with hydrochloric acid was studied in cell nuclei of different organs from young and old rats and after application of cortisol. Suspensions of cell nuclei from liver, spleen, kidney, heart muscle and mucosa from small intestine were stained with ethidium bromide without and after hydrolysis. The relative fluorescence intensity (FI) of every pair was measured by flow through cytophotometry. Always the FI of the diploid peaks of the hydrolysed samples was diminished. The resistance against hydrolysis was greater in old animals than in young. After application of cortisol in vivo in all organs, except in the liver, the resistance against hydrolysis was increased. Only the nuclei of liver from old animals showed a diminution of resistance after cortisol. It is assumed, that the greater resistance in age is due to the diminished functional ability of the nuclear chromatin. In the most organs, the inhibitory activity of cortisol to the cell metabolism is known, only in the liver cell it stimulates the synthesis of RNA and protein. This is in agreement with our findings.

Aging↗
PubMed1978

[Morphology and DNA content of cultures from normal and dysplastic epithelium, carcinoma in situ and carcinomas of the cervix uteri (author's transl)].

Morphology and DNA content were studied in explantate cultures of normal epithelium, persisting intraepithelial atypias (dysplasias and carcinomas in situ) and carcinomas of the cervix uteri. Intraepithelial atypias and carcinomas can be distinguished from the normal epithelium, growing strictly as a monolayer, chiefly by the primary and secondary loosening of the cellular lawn with increased tendency towards overlapping of cells. DNA determinations provide the possibility of demonstrating, also in vitro, deviations of the DNA content of dysplasias, carcinomas in situ and pavement epithelial carcinomas from the normal epithelium. The findings are in accord with the results which we obtained by in vivo studies and underlinions.

Biopsy↗
PubMed1978

Pulse cytophotometric measurements on tumor cell suspensions and exfoliative material.

By impulse cytophotometry (ICP) it is possible to get a DNA-distribution curve of nuclei in cell suspensions. The ICP curve directly represents the ploidy pattern of the investigated cell population and, more indirectly the proliferation intensity. For practical tumor diagnosis in cytology by ICP as a first step we must know, wether the ICP is able to detect differences between normal and tumor cells by simple criteria. Together with our clinical coworkers we had investigated cell suspensions from carcinomas of the cervix, ovary, breast, larynx, stomach and malignant melanomas. Approximately one half of these tumors were poly- or aneuploid. In the remaining diploid tumors some did not show signs of strong proliferation in the form of high 4c-peaks in the ICP; for these the chances of detecting by ICP in exfoliative material are low. This is in agreement with our results on vaginal smears. Here we had a good correlation between the mean 4c-height of the ICP curves and the Papanicolaou grading. But mass screening is not the main application of ICP because the security of Pa-grading is more sufficient. In individual problematic cytological cases with repeated investigation ICP is a very valuable diagnostic aid.

Cell Division↗
PubMed1977

Pulse cytophotometric investigations concerning ploidy and proliferation pattern of invasive squamous cell carcinomas of the cervix uteri.

Tumor cell suspensions from 100 biopsies of squamous cell carcinomas of the cervix uteri were investigated by impulse cytophotometry (ICP) after staining with pepsin-ethidium bromide. We estimated the ploidy pattern by comparing the ICP curves with normal diploid material. The originally linearly classified curves were transformed in a logarithmical manner. We found 48 diploid populations and 42 polyploid populations, among them 19 tetraploid tumors. In these the 4c-peak was the highest. In 10 cases there were aneuploid stem lines, mainly lying between 2c and 4c; 2 curves had a hypertetraploid pattern. Helpful for interpretation of the whole curve is the introduction of an index: the "relative mean DNA-content" (DNA). In 15 diploid tumors we found a low proliferating rate, characterized by low 4c-peaks. For interpretation of polyploid cell cycles a completed nomenclature of cell cycle phases was introduced. Comparing our material with chromosome analyses in laterature we found more polyploid, e.g. tetraploid tumors. It can be assumed that the estimation of ploidy pattern solely by DNA measurements has another meaning than by chromosome analyses. The higher ploid peaks in DNA distribution curves (e.g. ICP-karyograms) represent not only true polyploid nuclei but also nuclei which are in a blocked premitotic resting phase (G2 for 4c; G'2 for 8c and so on). The ICP is a valuable method for estimating biological pecularities of tumor cell suspensions.

Biopsy↗
PubMed1977

[On some aspects of modern research of arteriosclerosis (author's transl)].

Atherogenesis is the result of interactions of factors originating from blood stream and the reaction of the arterial wall. Basing on this we have a pathogenetic trias: blood--lining membrane--arterial wall. Under these aspects some modern trends of experimental research are discussed. An example of blood-plasmatic injury is the hyperlipidaemia. The permeability of the lining endothelium regulates the infiltration and is influenced by several factors. The reactions of the modified smooth muscle cells in the arterial wall are the most important events in early atherogenesis. The metabolic decompensation of these cells is a main factor in the transition to advanced lesions. The efficiency of the cells is the preliminary condition for the reversibility of atherosclerotic lesions. Only early stages have some chances of regression; one must bear in mind this together with all therapeutical treatments.

Animals↗
PubMed1977

A study of the catabolism of fibrinogen after myocardial infarction.

The catabolism of fibrinogen was studied during the first week of acute myocardial infarction in twenty-three patients and in ten control patients. A trial was carried out using 125I-labelled fibrinogen. After myocardial infarction, the mean biological half-life of fibrinogen was 62.5 +/- 10.0 h and the mean plasma loss of fibrinogen per 24 hours was 34.1 +/- 6.9% of the intravascular fibrinogen pool. In the control group, respective values of 89.6 +/- 9.9 and 23.4 +/- 3.9% were obtained, which were in close agreement with published values for the normal catabolism of fibrinogen. The fractional catabolic rate of the intravascular fibrinogen pool was significantly increased in patients with myocardial infarction in contrast to the absolute plasma loss of fibrinogen which appeared to be the same as in subjects with normal plasma fibrinogen concentration. Possible explanations of the accelerated catabolism of fibrinogen after myocardial infarction are discussed.

Acute Disease↗