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Biomedical subjects

H Fischer

Publications and source records attributed to H Fischer.

At least 415 records · Page 23Linked to original sources
PubMed1982

Thrombin-like snake venom proteinases.

Proteinases affecting one or several physiological thrombin substrates are current components of Crotalidae and Viperidae venoms. Enzymes causing in vitro coagulation of fibrinogen without affecting other thrombin-susceptible blood constituents as well as enzymes affecting platelets, F. V. VIII and XIII with only minor action on fibrinogen have been isolated. Fibrinogen affecting proteinases may catalyze the release of either fibrinopeptide (Fp) A (e.g. ancrod, batroxobin) or Fp B (Agk, contortrix proteinase) or of both Fp A and B (B. gabonica proteinase). Some of these enzymes are inhibited by AT III-heparin complex (e.g. Agk. contortrix proteinase) some are not inhibited by either AT III-heparin or hirudin (e. g. batroxobin). The application of Fp A releasing venom proteinases into animals causes transformation of fibrinogen into fibrin I monomer which is rapidly degraded by fibrinolysis and thereby leads to a state of afibrinogenaemia. The administered enzyme is gradually bound to serum proteinase-inhibitors and inactivated. A species dependent interaction between venom enzyme, fibrinogen and serum proteinase inhibitors creates specific differences in dose response relationship. Thus, batroxobin isolated from B. moojeni (HOGE) proved to be a superior defibrinogenating agent in man, as compared to the closely related enzyme isolated from B. atrox (L.). LD50 of B. atrox venom in previously batroxobin defibrinogenated mice is not significantly different as compared to normal animals, indicating an only minor role of batroxobin in Bothrops venom poisoning.

Aging↗
PubMed1982

Characterization of an ATPase on the inside of rat-liver nuclear envelopes by affinity labeling.

Nuclear envelope membranes from rat liver cells contain ATPases, one of which can be inhibited and irreversibly labeled by (S-dinitrophenyl)-6-mercaptopurine riboside triphosphate. Inhibition and covalent substitution of the ATPase are achieved only after disruption of the nuclei, the ATP analogue is inactive on the ATPase activity of whole nuclei or on vesicles of the membrane prepared after a modified heparin method of Bornens and Courvalin. Electron micrographs and scanning micrographs helped to establish the characterization of closed vesicles and intact nuclei. With the aid of (alpha-32P)-labeled, and of the (beta, gamma-32P)-labeled analogue, it was possible to demonstrate the incorporation of the nucleotide into a few protein regions of the nuclear membrane disc electrophoresis pattern.

Adenosine Triphosphatases↗
PubMed1982

Chemiluminescence response of peritoneal macrophages to parasitized erythrocytes and lysed erythrocytes from Plasmodium berghei-infected mice.

The chemiluminescence response of normal mouse peritoneal macrophages to parasitized erythrocytes isolated from mice 3 weeks after infection with Plasmodium berghei was examined. Only 4 of 12 animals showed positive responses, whereas 8 showed negative responses. Photomicrographs revealed that only in chemiluminescence-positive animals were parasitized erythrocytes attached to or phagocytized by macrophages. When lysed parasitized-erythrocyte cell suspensions were added to the peritoneal macrophages, chemiluminescence could be induced in all cases. The response was enhanced remarkably by the addition of very small amounts of immune serum. Normal macrophages activated in vitro by supernatant from antigen-stimulated spleen cells from immune mice showed much higher parasite-induced chemiluminescence responses than did nonactivated macrophages, especially in the presence of immune serum.

Animals↗
PubMed1982

[Effect of selective and non-selective adrenoceptor blockade during physical work on energy metabolism and sympatho-adrenergic system (author's transl)].

The influence of an acute beta-adrenoceptor blockade on work capacity, oxygen intake, plasma catecholamines, and on energy metabolism was investigated in 9 healthy subjects during graduated ergometric exercise. The examinations were carried out after p.o. administration of 10 mg bunitrolol (BU), methypranol (ME) and placebo in random sequence. The exercise capacity shows a 15% decrease after both beta-blockers; heart rate shows a maximum 20% (BU) and 25% (ME) reduction, respectively. On account of the greater sympathetic intrinsic activity BU does not influence the resting heart rate, in contrast to ME (-8%; p greater than 0.05). BU leads to a decrease of the catecholamine levels (with low sympathetic tone), which is assumed to be caused by an effect on presynaptic receptors. At the same submaximum exercise levels plasma catecholamines are higher after BU and ME than after placebo; however, the maximum levels are not reached with placebo. In relation to the relative oxygen intake, which is inhibited by 4-6% by BU and ME (p greater than 0.05), the differences of the catecholamines decrease in performance caused by beta-blockade. BU does not show an influence on lactate, glucose, free fatty acids, and glycerin and thus represents a more selective blockade. ME inhibits lipolysis (measured by the glycerin level) by a maximum of approx. 50%. Lactate level increase is approx. 30% lower with ME. Glucose level decrease is approx. 20% higher with ME than with placebo.

Adrenergic beta-Antagonists↗
PubMed1982

Studies on the hypertriglyceridemia in pregnant rats.

The study has been performed in order to obtain information on the mechanism responsible for the hypertriglyceridemia found in pregnant rats. The results show that the whole plasma triglyceride flux is increased by 65% in late gestation. It has been found that labeled VLDL triglyceride originating from pregnant rats shows no delay in plasma disappearance when injected into the circulation of non pregnant female rats. Contrariwise, labeled VLDL triglyceride originating from non pregnant rats when injected into pregnant rats shows a delay in disappearance from the circulation. From these results the conclusion can be drawn that the delay in labeled plasma triglyceride disappearance in late gestation is not caused by a possibly abnormal VLDL showing a decrease in affinity of lipoprotein substrate for lipoprotein lipase. Therefore, we interpret the delay in labeled plasma triglyceride disappearance in late gestation in terms of a lowered removal capacity of plasma triglyceride by extrahepatic tissue.

Animals↗
PubMed1982

Immunological reactivity to soluble tumour extracts (STE) in gastrointestinal tumours and related risk groups.

One of the mose important demands on tumour diagnosis is the detection of early and recurring cancer. Recently, immunological tests have revealed possibilities of meeting these expectations. By means of the leukocyte adherence inhibition test (LAI) as tube test we investigated the immunoreactivity of leukocytes of leukocytes to STE in patients with colonic and gastric carcinoma, and the risk groups of Biermer's disease and colonic polyps. As control groups we used 30 blood donors and 37 patients with non malignant colonic diseases. The detection of autoantibodies with the indirect immunofluorescence technique and immune complexes supplemented the immunological investigations. The LAI and STE used are suitable for the diagnosis of gastric and colonic cancer with a rate of accuracy of more than 90 per cent. In the risk groups of colonic polyps the LAI offers a good possibility of detecting early carcinomas, and of monitoring the successful removal of polyps. Problems of autoimmunity in Biermer's disease and colitis ulcerosa do not allow a definite decision regarding a malignant stage in LAI positive patients.

Adult↗
PubMed1981

[Plasma catecholamines, metabolic substrates, aerobic and anaerobic capacity during exercise in supine and sitting position (author's transl)].

The influence of a graduated bicycle ergometric test in supine and sitting position on the work capacity, the plasma catecholamines, the carbohydrate (glucose and lactate) and lipid metabolism (free fatty acids and glycerol) and the heart rate and oxygen intake was examined in six healthy subjects. The work capacity is approx. 30% higher in sitting position. In supine position, adrenaline and nor-adrenaline are lower at rest, at all submaximum levels and during maximum ergometric exercise. Glucose, free fatty acids and glycerol show no differences dependent on the body position at the same submaximum levels, only the lactate level is approx. 30% higher (200 Watt) in supine position. During maximum graduated exercise in sitting position the glucose level is 10% higher than in supine position, the free fatty acids show no difference; the lactate level is approx. 37% higher, the glycerol level approx. 40% than in supine position. The heart rate and the oxygen intake don't show any position dependent differences at rest and at the same submaximum levels. During maximum ergometric exercise they are 15% (heart rate) and about 30% (oxygen intake) higher than in supine position, corresponding to a higher exercise level.

Adult↗
PubMed1981

Concanavalin A-induced chemiluminescence in rat thymus lymphocytes. Its origin and role in mitogenesis.

1. The luminol-dependent chemiluminescence of rat thymocytes responding to concanavalin A can be resolved into glucose-dependent and glucose-independent portions. 2. The glucose-dependent portion, supported by D-glucose and D-mannose oxidation, is inhibited by catalase (200 microgram/ml), amobarbital (1 mM) and hexose analogues that block D-glucose uptake. Thus concanavalin A may activate, transiently, an NAD(P)H oxidase that utilizes reducing equivalents derived from the oxidation of exogenous glucose to give dismutation products of O2- (including H2O2) as its major products. 3. The glucose-independent portion is inhibited by eicosa-5,8,11,14-tetraynoic acid but not by indomethacin. It may therefore be associated with the conversion of hydroperoxy intermediates of arachidonic acid metabolism to hydroxy products by the lipoxygenase pathway. 4. Preincubation of thymocytes for 18 h in serum-free medium enhances the subsequent chemiluminescent response to concanavalin A severalfold and evokes the response at a lower threshold concentration. The incorporation of [3H]thymidine by preincubated cells is similarly enhanced at low doses of concanavalin A, whereas the response to optimal doses is unaltered. 5. Catalase does not inhibit the enhanced incorporation of [3H]thymidine obtained in response to concanavalin A, but instead amplifies the response to low doses in the same manner as preincubation.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1981

[Prevention of hypertension of the city borough of Schwedt/Oder--results to date of a regional intervention program].

More than 1,100 women and about 1,400 men, detected as being hypertensives in population screenings for cardiovascular diseases and coronary risk factors on 30-59 year-old females and 30-64-year-old males 1975 and 1976, respectively, in Schwedt - participation rate in both screenings 78 per cent (6,514 females and 7,137 males, respectively) - underwent an intervention programme carried out by all the general practitioners, physicians for industrial medicine and internists, working in the out-patient clinics of the territory. But in 1979 only 500 of these women and approximately 800 of these men were under continuous control. These registration rates after both the screenings as well as after the first follow-up in women 1977, therefore, have to be considered as unsatisfying. That lack in registration is mainly up to the enormous fluctuation of patients - and inhabitants at all-, being a characteristic feature of the population of the newly built town of Schwedt. In order to overcome these effects of migration within the territory and to improve supervision in hypertensives, a new control system regarding the peculiarities of Schwedt was established. In contrary to the failing registration an efficient lowering of blood pressure levels was achieved in those patients cooperating well, revealing normotensive diastolic mean values and systolic mean values, ranging from normotension to the lower borderline pressures. In women who showed a more impressive effect of treatment than men, the effective lowering could be maintained over a 4-year-follow-up period up to now.

Adult↗
PubMed1981

Control of arachidonic acid accumulation in bone marrow-derived macrophages by acyltransferases.

The turnover of phospholipid fatty acid moieties of bone marrow-derived macrophages was analyzed by separate determination of degrading and acylating activities. Acylating activities were followed in intact cells by incubation with excess arachidonic acid and degradation of phospholipids was followed in cells prelabeled with fatty acids. Significant phospholipase A2 activity was detectable only if the reutilization of liberated fatty acid was inhibited , e.g. by p-chloromercuribenzoate. It was of interest that the divalent cation ionophore A 23187 and various antiphlogistic drugs like indomethacin, diclofenac, and acetylsalicylic acid were found to inhibit the acylation reaction. These compounds led to increased levels of free arachidonic acid in stimulated, as well as in unstimulated cells. Increased activities of phospholipase A2 were achieved by treatment with the bivalent cation ionophore A 23187 and with zymosan. The effect of zymosan obtained from various sources was found to be exclusively due to contamination of tee zymosan particles with phospholipase A2 activity. Even when the cellular phospholipase activity was increased by the addition of exogenous phospholipase activity contained in the zymosan particles, degradation of cellular phospholipids was not measurable unless the reacylation was inhibited. These results suggest that in the cells studied, the level of free arachidonic acid is mainly controlled by the activity of the lysophosphatide acyltransferase.

Acyltransferases↗
PubMed1981

[Hyperthyroidism and anemia].

In a random test of 100 patients with hyperthyroidism with clinical and paraclinical ascertainment of the diagnosis in 38 cases normo-hypochromic, normocytary anaemias of different expression were found. In the patients with anaemia the serum hormone values were statistically significantly higher than in the 62 patients without anaemia. Also cardiotoxic and hepatotoxic findings were more frequently to be proved in patients with anaemia. A causal iron deficiency, deficit of vitamin B12 or folic acid as well as a haemolytic component of the induction of anaemia could vastly be excluded. By means of the treatment of the basic disease and metabolic balance a normalisation of hemoglobin was achieved without additional medication. From the results of the examinations is concluded that above all a thyreotoxic damage is responsible for the development of the anaemia. In cases of oligo-symptomatic hyperthyroidism part from hepatotoxicity and cardiotoxicity also anaemias may become a leading symptom.

Adolescent↗
PubMed1981

[Differential diagnosis of peripheral lymph node enlargement].

The diagnostics of swelling of lymph nodes is in the first place directed to the exclusion of malignant lymphomas and metastases. In these cases, however, the histological investigation is the method with the highest value, but only then, when it is performed by an experienced morphologist including clinical findings. Therefore, it may be only the final point of thorough clinical, biochemical and serological findings. Already by cytological investigation in the majority of the swellings of lymphatic nodes a definitive diagnosis can be made. Among our own patients the proportion of the histologically examined swellings of the lymph nodes was about 21.3%. Punctures of the lymphatic nodes were performed in 41.6%. In the majority of the patients, a lymphotropic infection could be proved by blood picture, serum enzymes and serological findings. The proportion of malignant lymphomas was 14.3%.

Diagnosis, Differential↗