Search PubMed⌕ Search

Biomedical subjects

M Fischer

Publications and source records attributed to M Fischer.

At least 721 records · Page 40Linked to original sources
PubMed1979

The oncogenic effect of immunosuppressive (cytotoxic) agents in (NZB x NZW) mice. II. Emergence of tumors in young animals treated with azathioprine and ifosfamide, including a histologic assessment of the neoplasms.

The age of (NZB x NZW) mice treated with immunosuppressive agents has been associated with an increased incidence of neoplastic disease in certain experimental situations. In this study, azathioprine administered daily over a period of 7 to 8 months significantly increased the occurrence of malignancies in animals aged 6 to 12 weeks at the start of treatment. No such increase was observed for ifosfamide. The resulting lesions observed in azathioprine and ifosfamide treated hybrids were predominantly lymphomas (60 to 80%) and could be classified according to two histologic types: Type I and II. The lymphomas in the ifosfamide groups could not be distinguished histologically from those in the azathioprine groups.

Animals↗
PubMed1979

[Successes, failures and complications in thrombolytic therapy in peripheral, arterial and venous occlusions].

Thrombocytic therapy in peripheral arterial and venous vessel occlusion represents a clearly described alternative towards the surgery of vessels. A success rate of 36.5% can be found in subacute peripheral arterial thrombosis and 46.3% in subacute thrombotic occlusion of a bypass-graft. Contrary to that, a rate of 29.8% can be found in complications or side-effects respectively. In cases of peripheral deep venous thrombosis, a partial or full success can be found in 72%. However, the rate of complication amounting to 44.2% is comparatively high. The longer thrombolytic therapy with streptokinase or urokinase will last, the more frequently and more serious will be the complications, such as bleedings of different kind as well as increase of temperature to mention the most frequent ones. The application of urokinase is absolutely possible today, however, the use of urokinase seems to be only justified, if a thrombolytic therapy with streptokinase was carried out successfully and a subsequent surgical therapy was not possible. The present costs of this preparation are far too high for urokinase to be applied routinely. A thrombolytic therapy with SK as well as with UK has to be followed by an anticoagulant treatment.

Arterial Occlusive Diseases↗
PubMed1978

Fixation-sensitive areas in the eyes of the walking fly, Calliphora erythrocephala.

In Calliphora erythrocephala the visual fixation behaviour in one-eyed flies and partial blinded flies has been investigated. One-eyed flies show approximately the same stripe and edge fixation response as intact flies. Elimination of the frontal eye parts including the binocular field of vision does not effect the visual stripe fixation. On the other hand, if only the frontal areas of both eyes including the binocular field of vision are left open, no preferential direction can be observed (Fig. 1--3). The results imply the existence of a fixation-sensitive area of the eye located outside the binocular field of vision.

Animals↗
PubMed1978

Conversion of polycythemia vera to refractory anemia with hyperplastic bone marrow.

Clinical and morphologic findings in the conversion of treated polycythemia vera to pancytopenia with hyperplastic bone marrow (refractory anemia or pancytopenia with hyperplastic bone marrow) are described in light of our own observation. The nomenclature associated with this condition (pancytopenia, chronic erythroleukemia, preleukemia) is not uniform, whereas the morphologic findings are virtually identical. Some patients subsequently develop acute leukemia. The prognosis in cases of refractory anemia with hyperplastic bone marrow following polycythemia vera is, independent of the subsequent acute leukemia, invariably terminal.

Anemia, Aplastic↗
PubMed1978

Regulation of isopropylmalate isomerase synthesis in Neurospora crassa.

The capacity to synthetize isopropylmalate isomerase (EC 4.2.1.33) by Neurospora crassa increased during induction in the presence of cycloheximide but was inhibited by proflavine and other inhibitors of RNA synthesis. Turnover of the enzyme once formed appeared negligible, but the message (measured as enzyme-forming capacity) had a half-life of 4 to 8 min. A comparison of the kinetics of induction in the wild type and a newly isolated alpha-isopropylmalate-permeable strain suggested strongly that feedback control by leucine of alpha-isopropylmalate production can adequately serve as the primary physiological regulator of endogenous inducer concentration. Genetic data are presented which implicate the involvement of two unlinked genes, ipm-1 and ipm-2, in determining permeation of alpha-isopropylmalate.

Cycloheximide↗
PubMed1978

[Manometric studies of the anal canal in chronic primary fissure before and after management using dilatation or sphincterotomy].

Manometric investigations in patients with primary chronic fissure in ano were performed before and after stretching or sphincterotomy in a randomized clinical trial. Length of the functional anal canal was not influenced by the procedures. At a six-month follow-up, the maximum resting anal pressure was significantly lower in both groups. After stretching and sphincterotomy, the site of maximum pressure in the anal canal had moved orally. This demonstrates that an elevated resting anal pressure is one of the pathogenetic mechanisms for the development of a primary chronic fissure. It is successfully cut off by either stretching or sphincterotomy.

Adult↗
PubMed1978

[Dilatation or sphincterotomy as the treatment of primary-chronic fissure in ano. Results of a random, clinical study after 2-3 years].

In a randomized clinical trial, 66 patients were treated for primary chronic fissure-in-ano by anal dilatation or sphincterotomy. Of the 64 patients still living, 57 (89.0%) could be submitted to a follow-up examination 26.7 +/- 4.6 months after the operation; 63 of them were surveyed on the basis of a questionnaire. Six patients who had reported functional lesions after operation at a six-month follow-up were reexamined: in two cases improvements were recorded, in the case of three patients the symptoms remained unchanged, and in one case a complete reduction was achieved. Though no significant difference (p less than 0.1) was noted with a recurrence rate of 20.5% (n = 7) after the dilatation versus 3.1% (n = 1) after the sphincterotomy, a definite trend was obvious. These findings support the sphincterotomy as being a definitive therapy for primary chronic fissure-in-ano.

Adult↗
PubMed1978

[Clinic and therapy of anal fissure (author's transl)].

A distinction has to be made between primary and secondary anal fissure. If a secondary fissure is present, the underlying disease has to be treated in the first place. Surgery is the therapy of choice of chronic primary fissure; digital dilatation and sphincterotomy are used in most of these cases. Both methods were applied in a controlled, randomized study; results indicate that subcutaneous lateral sphincterotomy is to be preferred, since rates of postoperative incontinenece and of relapses are lower.

Colitis↗
PubMed1977

[Suppressive effect of somatostatin on secretin-CCK-PZ-stimulated endocrine and exocrine pancreatic function in man (author's transl)].

With a view toward the therapeutic use of somatostatin in the treatment of acute pancreatitis, a preliminary investigation was conducted with 6 healthy volunteers, in which the suppressive effect of somatostatin on endocrine and exocrine pancreatic function was observed. A 30-minute baseline measurement period was followed by the administration of cyclic somatostatin (100 microgram by i.v. injection plus a 90-minute infusion at a rate of 200 microgram/hr). After the first 45 minutes of this infusion secretion was submaximally stimulated by the infusion of secretin-cholecystokinin-pancreozymin (CCK-PZ) (75 U each), over two hours. No decrease was observed in basal bicarbonate or enzyme concentration under somatostatin administration alone. However, secretion did not show the usual steep rise after the commencement of stimulation. After the somatostatin infusion was stopped, i.e. under secretin-CCK-PZ alone, a significant increase occurred in the values of secretin-induced volume, bicarbonate concentration and total bicarbonate contents of the duodenal aspirate, as well as in CCK-PZ-induced enzyme secretion. The release of insulin, both basal and stimulated, was also significantly decreased by somatostatin.

Adult↗
PubMed1977

[Extracorporeal liver perfusion in the treatment of liver failure].

An evaluation of therapeutic approaches in acute liver failure needs essentially experimental studies. Devascularization of the liver seems to be the superior form of liver damage induced by a variety of toxins. A perfusion circuit for extracorporeal pig liver perfusion was investigated. Oxygen utilization of the livers under experimental conditions proved to be the fastest and most reliable test of organ viability. In therapeutic use in devascularized pigs the survival time could be prolonged. Biochemical parameters were normalized or improved during a 2 hour perfusion. The method was of value in a 59 year old patient perfused for 9 1/2 hours with an isolated baboon liver. Controlled trials, however, seem to be necessary to evaluate each therapeutic method in acute liver failure in man.

Animals↗
PubMed1977

[Macroscopic and micro-morphologic evaluation of viability in extracorporeal perfused pig livers (author's transl)].

Several biochemical reactions are used in evaluating viability of extracorporeal perfused livers. Simple and quick tests of organ function, however, are needed in therapeutic application in man. In 33 homologous porcine liver perfusions we found that accurate observation of the macroscopic aspect gave a good criterion of organ function. The combination with micro-morphologic findings, especially after perfusion with Indian ink, proved to be a reliable base for evaluating the functional state of the livers used.

Animals↗
PubMed1977

Histamine and acute haemorrhagic lesions in rat gastric mucosa: prevention of stress ulcer formation by (+)-catechin, an inhibitor of specific histidine decarboxylase in vitro.

Acute haemorrhagic lesions in the oesophagus, stomach and duodenum ('stress ulcers') occur relatively often under clinical conditions and are always dangerous to the patient (lethality rate about 70%). Since conservative and surgical treatment are without significant success up to now, prevention by adaptation to stressors or by administration of drugs seems mandatory. An improved technique for producing acute gastric lesions in rats by immobilization and a new method for assessing this disease in the animals is presented in this communication. High precision is obtained within a single experimental series especially from day to day. Since histamine was suggested to be involved in the pathogenesis of stress ulcer disease, (+)-catechin, a rather specific inhibitor of specific histidine decarboxylase from rat stomach, was tested in immobilized rats. It prevented the formation of acute gastric lesions by 80% in seven series of experiments lasting for half a year. Since the drug has low toxicity in man, it is recommended for clinical trials.

Analysis of Variance↗