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Biomedical subjects

D Kranz

Publications and source records attributed to D Kranz.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Causes of death in the aged and their significance for surgery].

Based on an analysis of the most frequent causes of death in old age, i.e. cardiovascular diseases, pulmonary diseases and neoplasia, a number of consequences can be drawn from the surgical point of view. It is undoubtedly difficult still to find ways and means of prolonging the life of an elderly person suffering from an acute illness in the presence of degenerative cardiac and vascular diseases. Yet we feel, that interdisciplinary cooperation with a high degree of responsibility between surgeons, internal specialists and anesthetists still offers possibilities to achieve this aim. All efforts should be focused on relieving cardiovascular and respiratory insufficiency. Furthermore, we regard surgery at the time of choice as an opportunity to reduce mortality rates which are greatly influenced by complications of diseases requiring an operation. The success of an operation depends on precise surgical work and swift acting. It should be a moral duty not only of the medical profession, but also of young people to treat the elderly with esteem, respect, love and care.

Age Factors↗
PubMed1981

[Autoradiographic investigations on postnatal proliferative activity of the matrix-zones of the brain in the trout (Salmo irideus) (author's transl)].

The localization and proliferative activity of the matrix-zones has been investigated in the brains of 60 teleosts (Salmo irideus) by means of autoradiographs, after injection of tritiated thymidine at different stages of the postnatal life. There are no previous detailed autoradiographical reports on postnatal brain development in the trout. Matrix-zones (i.e. ventricular and subventricular zone) exist postnatally in all parts of the teleost brain: we have found these in the forebrain, in many diencephalic recessus, in the optic tectum, in cerebellar valvula and corpus, and in the medulla. The quantitative part of this study indicates high values of the labeling-index at the first days after birth. Then, the labeling-index decreases rapidly up to the 25th day. But also in 2 years old specimen labeled cells were observed in the matrix-zones of the central nervous systems; therefore a few of proliferative capacity remains in adult fishes.

Animals↗
PubMed1981

[Autoradiographic investigations on the age dependent regeneration of parenchymal liver cells (author's transl)].

It is possible to represent the age dependent change of the ability of reproduction on the model of liver regeneration. Because of the reduced growth fraction with increasing age there is a delay of the beginning and a decrease of the maximum ascent of regeneration. In old rats the proliferating activity decreases to consistently low levels earlier than in young and adult rats. There are no age dependent differences in the total amount of regeneration 21 days after 1/3 hepatectomy. In contrast to the literature we are able to show, that already by means of 1/3 hepatectomy highest values of liver regeneration are achievable.

Age Factors↗
PubMed1981

[Autoradiographic investigations on postnatal proliferative activity of the telencephalic and diencephalic matrix-zones in the axolotl (Ambystoma mexicanum), with special references to the olfactory organ (author's transl)].

The localization and proliferative activity of the matrix-zones has been investigated in the telencephalon and in the diencephalon of 21 axolotls (Ambystoma mexicanum) by means of autoradiographs, after injection of tritiated thymidine at different stages of the postnatal life. There are no previous detailed autoradiographical reports on postnatal brain development in the axolotl. Matrix-zones (i.e. ventricular and subventricular zone) exist in the dorsal part and in the ventral part of the telencephalon, we have found these also in the diencephalon in the wall of the preoptic recessus and ventrally of the habenula. The quantitative part of this study indicates high values of the labeling-index in the early postnatal stages. Then, the labeling-index decreases, but also in 3 years old specimens labeled cells were observed in the matrix-zones of the telencephalon; therefore a few of proliferative capacity remains in the central nervous system of adult axolotls. Labeled cells were also found in the olfactory organ of early postnatal and adult axolotls; these are neuroblasts which have relevance for the regeneration of the forebrain.

Ambystoma↗
PubMed1981

[Experimental autoradiographic study on the proliferation kinetics of the ischemically injured rat small intestine].

The kinetics of proliferation of the ischemically injured small intestine in rats were tested after recovery of the circulation in dependence on the age by means of the autoradiography. The marking index and the middle density of silver grain were applied. The time of the anoxia amounted to 3 hours, since in that case a regeneration can hardly be expected after this time. With a complete regeneration both the number of the synthesizing cells and the synthesized DNA quantity can be calculated after the recovery of circulation. Differences dependent on the age become clear, in a similar way to the physiological kinetics of proliferation. The values of comparison with the control group are reached in rats at an age of 6 weeks already after nearly 18 to 20 hours. On the other hand the time of the regeneration amounted to nearly 36 to 48 hours in the rats at the age of 12 months. The demand of an early diagnosis and recovery of the circulation within 3 hours is emphasized.

Age Factors↗
PubMed1980

[The aging of intermitotic cells (author's transl)].

The aging of the cells depends on their mitotic activity, which is particularly evident in multicellular organisms. By way of histoautoradiography we studied the cell kinetics on a total of 244 Wistar rats aged 6 days, 6 weeks, 6, 12, 23 and 28 months respectively, with these studies being centred on the mucosa of the small intestine since this mucosa is one of those tissues with the highest cell metabolism. We succeeded in demonstrating that the regeneration rate of cells per hour in the crypts of the small intestine and the migration speed of the enterocytes differ in young and old individuals and that the intermitotic cells have age-dependent properties as well. In addition, we could prove that intermitotic cells too have a non-growth fraction which, at an advanced age, decreases only a little, although significantly in terms of statistics. For the easily vulnerable crypt epithelium it is a reserve capacity and can be included in the proliferating pool, if necessary.

Animals↗
PubMed1980

[On the effect of biologically active substances (experimental studies) (author's transl)].

The influence of prolonged Procaine and Turigeran therapy on the cellular kinetics of the mucous membrane of the liver and small intestine has been studied by means of 3H-thymidine histo-autoradiography of a total of 240 12-month-old male Wistar rats. The following observations have been made: 1. The pool of DNA-synthesizing liver parenchyma cells and Kupffer's cells in the treated animals is clearly increased compared with that of the untreated controls. There is no difference between the rats treated with Procaine and those treated with Turigeran. 2. Nor does the cellular kinetics of the mucosa of the small intestine exhibit any differences between the animals treated with Procaine and those treated with Turigeran. Since, on the other hand, significant differences appear between the treated animals and the untreated controls regarding all characteristics of cellular kinetics, this effect is solely attributable to Procaine. 3. The various phases of the cellular cycle are prolonged in the treated animals, resulting in an overall delay in the generative cycle. 4. A reduced speed of migration of the cells in the region of crypts and villi finally results in the fact that in spite of the reduced rates of proliferation a greater number of labelled cells can be observed in the crypts of the treated animals (labelling index). 5. The unmitigated effect of Procaine is discernible for at least two weeks after the discontinuation of the treatment.

Animals↗
PubMed1980

[Autoradiography of neurogenesis and morphogenesis of the regio cingularis of the rat. V. Quantitative examinations of the course of cell migration].

The course of migration has been investigated; the migration begins at the 3rd day after injection of tritiated thymidine, at the 7th day the distribution of labeled cells is stable. The fate of cortical plate indicates 2 subdivisions: an inner zone and an outer zone with cells determinated for the cortical layers respectively following the day of origin. It was also explored the lamination, the speed of migration and the transitory localization of labeled cells.

Age Factors↗
PubMed1980

[Autoradiographic investigations of age-dependent proliferation kinetics in the small intestine mucosa of rate (author's transl)].

Aging of cells depends on mitotic activity which is particularly evident in multicellular organisms. By means of histoautoradiography we studied the cell kinetics of the mucosa of the small intestine in a total of 244 Wistar rats aged 6 days, 6 weeks, 6, 12, 23 and 28 months, resp. We could demonstrate that the regeneration rate of cells per hour in the crypts of the small intestine and the migration velocity of the enterocytes differ in young and old individuals, and that the intermitotic cells have age-dependent properties as well. In addition, we could prove that intermitotic cells have a nongrowth fraction, too, which at an advanced age, decreases only slightly although significantly in terms of statistics. For the easily vulnerable crypt epithelium it is a reserve capacity and can b included in the proliferating pool if necessary.

Age Factors↗
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

[Autoradiography of the neurogenesis and morphogenesis of the regio cingularis in the rat. II. Proliferation kinetics in the area praecentralis agranularis].

The proliferation of the matrix-cells in the Area praecentralis agranularis of 219 embryonic rats has been investigated by means of autoradiographs, after injection of tritiated thymidine at different stages of foetal life. The course of the labeling index indicates that matrix-cells represent a cell population in which cell multiplication is both rapid and continuous. Moreover the number of labeled cells decreases following the migration of labeled neuroblasts to another site. Because the beginning of migration retards after a division a proliferative compartment and a differentiating compartment were found in the subventricular and ventricular zone. The migration appears in waves not before 24 hours after division of cells. We have found that, between the second and the third day and betw-en the third and the fourth day after injection, migrating cells arise with 1/2 or 1/4 of the number of silver grains respectively. A comparison with the values of the Regio cingularis mesoneocorticalis (RICHTER and KRANZ 1978) indicates that no differences exist between the both regions. Cell division and migration both indicate in the brain a sequential nature; after each mitosis only one of the daughtercells retains their proliferative capacity, the other becomes differentiated into neuroblast and leaves the proliferative compartment.

Age Factors↗
PubMed1979

[Autoradiography of neurogenesis and morphogenesis in the regio cingularis of the rat. III. Migration and lamination in the regions of the cingulate cortex and the area postcentralis].

The migration has been investigated in 171 embryonic and neonatal rats by means of autoradiographs, after injection of tritiated thymidine from E 18 to P 12 in 4 regions of the brain (Mesoarchicortex, Regio cingularis mesoneocorticalis, Area praecentralis angranularis, Area postcentralis). The migration begins at the third day after the injection. The localization of labeled cells was found in the cortical plate after injection in the early embryonic period and in the L II after injection in the late phasis always at the third day, the speed of migration increases in the course of embryonic development. The migration indicates in all regions an inside-out sequence. Cells from the last division migrates to the surface of the cortical plate. The cortical plate is a transitory element of the brain development. The lamination is possible earlier by means of the distribution pattern of labeled cells than with cytoarchitectonics and also the observation of areas.

Age Factors↗