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Biomedical subjects

H Franke

Publications and source records attributed to H Franke.

At least 145 records · Page 8Linked to original sources
PubMed1977

[Electron microscopic investigations on the influence of lymphocytes of sensitized and non-sensitized guinea pigs on the visceral yolk sac epithelium of the rat (author's transl)].

Rats on day 19 of pregnancy were intrauterinely injected lymphocytes from guinea-pigs, sensitized or not sensitized to trophoblast antigens of the rat placenta. In the first case locally severe cytolytic effects were observed on the yolk-sac surface, in the second case--the controls--no immune reaction was evident.

Animals↗
PubMed1976

The effect of intrauterinely injected lymphocytes prepared from sensitized or non-sensitized guinea-pigs on the ultrastructure of rat fetal membranes (visceral yolk sac).

The susceptibility of rat fetal membranes (visceral yolk sac) to cell-mediated immunity was studied electron microscopically at day 19 of pregnancy. For this purpose guinea-pigs were sensitized to rat placental antigens and the activated lymphocytes were injected intrauterinely. Simultaneously, the effect of lymphocytes from non-sensitized guinea-pigs was examined on the rat yolk sac. Lymphocytes from sensitized guinea-pigs revealed a clear cytotoxic effect on the visceral yolk sac, but the degree of cell destruction showed marked differences from one epithelial cell to the other. Furthermore, the yolk sac regionally displayed great differences in the intensity of immune cytolysis...

Animals↗
PubMed1976

Oxygen delivery in perfused rat kidney: NADH fluorescence and renal functional state.

Changes in steady-state levels of reduced pyridine nucleotide (PN) recorded by continuous monitoring of surface fluorescence were correlated with changes in physiological function of perfused rat kidneys when subjected to anoxia, ischemia, hypothermia, variations in perfusion pressure, inhibition of Na-K ATPase, and uncoupling of oxidative phosphorylation. Biphasic responses of PN reduction and oxidation during ischemic cycles at varying temperatures and anoxic cycles at different perfusion pressures demonstrated the presence of two different cell populations in the kidney cortex, those with sufficient oxygen and those without. The magnitude of PN fluorescence change during ischemia increased with decreasing temperature demonstrating better tissue oxygenation during hypothermia. The measurement of mitochondrial NADH oxidation in the perfused kidney during transitions from CO anoxia to normoxia was made possible by flash photolytic activation of mitochondrial electron transport. The half time for NADH oxidation (125 ms) was independent of the rate of oxygen delivery while the initial rate and extent of reaction was faster and steeper, respectively, at higher perfusion pressure, due to a better tissue oxygenation and faster CO washout.

Adenosine Triphosphatases↗
PubMed1976

[The so-called aging heart in 50- to 100-year-old subjects].

The cardiovascular system of aging people exhibits a number of morphological, functional and clinical special features. Alterations in shape, size and weight of the heart, alterations of coronary arteries, valves and aorta are accompanied by typical changes in several hemodynamics variables. The result is a diminution of the adaptation capacity to physical exertion and increased incidence of failure. However, heart failure cannot be regarded as a physiological process; it is caused by a coincidence of an increasing polypathy of the aging heart (coronary artery disease, arteriosclerosis, hypertrophy, valve-changes,disseminated degenerative changes) and the polypathy or multimorbidity of the whole aging organism. In advanced age the various forms of ischaemic heart disease (angina pectoris, infarction, failure, arrhythmias) show increasingly atypical courses, complications and a higher degree of mortality. Modern therapeutic measures like demand pacemakers or bypass operations are principally applicable. Our study of now 326 patients of very high age shows that the good state of their cardiovascular system (probably genetically determined) is mainly responsible for reaching high age.

Age Factors↗
PubMed1975

[The occurrence of eclampsia in the last six decades in the University Gynecological Hospital, Greifswald )author's transl)].

Epricrisis evaluation of 308 eclampsias which were observed from 1910-1974 in a total of 62,910 birth (0,5%) showed a reduction of incidence from 3.1% to 0%. The etiology of eclampsia is still unknown even today. Primiparae are most frequently affected. Preexisting renal diseases and the pathological complications of a gestosis play a role. During the 64 years, therapy has alternated between the conservative and active. Accouchement force, if at all possible within the first hour after the first attack and simultaneous drug therapy (hypotensives, sedatives, diuretics) gave the best results. The regression of the frequency of eclampsia is due to the intensive antenatal consultation.

Age Factors↗
PubMed1975

Acute changes of the Na-K-ATPase-activity in plasmamembranes of the isolated, cell-free perfused rat kidney.

The Na-K-ATPase-activity of the isolated, cell-free perfused rat kidney was investigated. Na-load and perfusion rate could be varied independently. The ATPase-assay was carried out on plasmamembranes (700-1200 g fraction) isolated and purified after 60 min perfusion. Both the specific Na-K-ATPase-activity and the fractional Na-reabsorption showed an indirect correlation with the Na-load as well as with the perfusion rate. The Na-K-ATPase-activity of plasmamembranes obtained from the isolated kidney at physiological Na-load fits well to control values prepared from unperfused control kidneys. The present data are in accord with the results of earlier micropuncture experiments, where acute saline loading diminished the rate of Na-absorption.

Absorption↗
PubMed1975

Fine structure and pinocytic activity of the visceral epithelium of the rat yolk sac incubated in a culture medium with or without goat antirat-placenta-IgG.

The fine structure and pinocytic activity of the rat visceral yolk sac epithelium were examined electron microscopically after incubation in Krebs-Ringer-Phosphate solution containing either 125-I-labeled albumin or goat antirat-placenta-IgG or both compounds simultaneously. Addition of 125-I-albumin to the incubation medium stimulates the pinocytosis, whereas the addition of goat antirat-placenta-IgG, cross-reacting with the yolk sac tissue, causes a diminution of the pinocytic activity of the yolk sac epithelium. Fine structural alterations and lesions are generally noticed. Preincubation of yolk sacs in Krebs-Ringer-Phosphate solution containing goat antirat-placent-IgG and the subsequent postincubation in a new Krebs-Ringer-Phosphate medium with 125-I-albumin does not restore the original pinocytic activity of the visceral epithelial cells.

Animals↗
PubMed1975

[Function and morphology of isolated rat kidney following cellfree perfusion with various plasmaexpanders (author's transl)].

Isolated arteficially perfused rat kidneys prepared as described by Franke et al. (1971) were perfused for 60 min with solutions of Haemaccel, Dextran 40, Pluronic-F-108, or hydroxy-aethyl starch in a single pass system. The glomerular filtration rate (GFR) of the Haemaccel or Dextran 40 perfused organs amounted during the first 30 min to 0.58 ml X g-1 X min-1 and 0.47 ml X g-1 X min-1 respectively. Using Pluronic-F-108 or hydroxy-aethyl starch GFR rose to 0.94 ml X g-1 X min-1 and to 0.85 ml X G-1 X min-1. With Haemaccel or Dextran 40 solutions a mean tubular Na-reabsorption of 75.4 mumol X g-1 X min-1 and of 59 mumol X g-1 X min-1 respectively was determined. Employing Pluronic-F-108 or hydroxy-aethyl starch a mean sodium net transport of 92.6 mumol X g-1 X min-1 in both experimental groups was obtained. The differences described in the functional capabilities of Haemaccel or Dextran 40 and of Pluronic-F-108 or Hydroxyethyl starch perfused kidneys are in good accordance with morphological changes in the ultrastructure. The most striking morphological deviations were found in proximal tubules of those kidneys perfused with Haemaccel solutions. On the other hand after perfusion with hydroxyethyl starch only very few morphological alterations could be detected.

Animals↗
PubMed1975

Substrate oxidation and inhibition of sodium transport in the isolated perfused rat kidney.

The relationship between the oxidative substrate-turnover-rate and the active Na+-transport was investigated. Our special interest was directed to the possible dependence of the oxidative turnover-rate of one selected substrate from the mode of reduction of the Na+-transport. The following methods were used: 1. Blocking the active Na+-transport by the addition of ouabain to the perfusion medium (0, 5 mg/ml); 2. Reduction of the sodium concentration in the perfusion medium to 100mM substituting NaCl by Tris/HCl; 3. Reduction of the perfusion pressure resulting in a low GFR and a low tubular Na+-load. The perfusion medium contained the following substrates in normal plasma concentrations: Na-palmitate, Na-oleate, Na-propionate, Na-acetate, D-glucose, Na-pyruvate, Na-L-lactate and Na-glutamate. The substrate in question was uniformly 14C-labelled; its amount oxidized per unit time was calculated on the basis of the 14CO2 formed. The following substrates were studied; Na-acetate, Na-pyruvate and Na-L-lactate. There were no significant differences between the results of the three methods described.

Acetates↗