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Biomedical subjects

F Koch

Publications and source records attributed to F Koch.

At least 127 records · Page 7Linked to original sources
PubMed1985

Two 14q+ chromosomes in malignant lymphoma: crucial cytogenetic changes on 14q.

We encountered a 36-year-old white male patient with poorly differentiated lymphocytic lymphoma, whose lymph node cells showed a clonal cytogenetic change involving chromosome #14, i.e., 47,XY, + 2,der(14),t(14;14)(14pter----14q32;14q24----14q32++ +). In addition to this change, cells with a translocation between chromosomes #2 and another #14 [t(2;14)(q21;q24)], as well as a missing chromosome #8 were found. We have reviewed the literature dealing with two or more changes affecting chromosome #14 and discussed the importance of the cytogenetic change at band 14q32 in malignant lymphoma.

Adult↗
PubMed1985

Ultrasonically guided fine needle aspiration biopsy of renal masses.

A consecutive series of 301 ultrasonically guided fine needle aspiration biopsies of renal masses was reviewed. The retrieval rate was 95 per cent and a correct cytological diagnosis was established in 82 per cent of the cases. There were 14 false positive aspirates, for a predictive value of a malignant aspirate of only 93 per cent. All false positive results were misinterpreted as relatively well differentiated adenocarcinoma. We conclude that renal fine needle aspiration biopsy may add information but the risk of a false positive finding must always be considered.

Biopsy, Needle↗
PubMed1980

Amplification of translational control by membrane-mediated events: a pleiotropic effect on cellular and viral gene expression.

This review deals with the events which are triggered in tissue culture cells upon exposure to medium hyperosmolarity, to virus infection and to inducers of terminal differentiation. Increased medium osmolarity mimics, in several ways, events which follow infection of cells by cytopathogenic viruses. These are: inhibition of uptake of amino acids, glucose and uridine, the release or activation of a low molecular weight substance which mediates an immediate and specific inhibition of polypeptide chain initiation, and alteration in the phosphorylation state of ribosomal proteins. All these effects appear to be related to or be a consequence of membrane alterations. Similar alterations in transport and protein synthesis are initiated in Friend erythroleukemic cells upon induction of terminal differentiation.

Amino Acids↗
PubMed1980

[Effect of immunization on the quantitative behavior of gamma globulins in the blood serum of cattle following whole-body x-ray irradiation].

Five experiment series were applied to 38 calves, aged between two-and-a-half and four months, using whole-body exposure to X-ray treatment based on median lethal doses (MLD) between 1.2 Gy and 1.7 Gy. Various methods of immunisation were simultaneously applied, and their effects on irradiation-caused response of gamma globulin concentrations in blood serum were studied. Gamma globulin levels were determined by Kunkel's zinc sulphate turbidity test. Immunisation applied between 14 and 21 days prior to irradiation resulted on obvious stimulation of gamma globulin production. In two experiments with parenteral antigen application, gamma globulin levels increased through about 14 days in apparently irradiated animals declined, after that period of time, but they continued to rise in really irradiated probands. A high lethal dose of 1.7 Gy, however, was followed by significant drop, three weeks after irradiation, that is in concomitance with the climax of the radiation syndrome. When 1.5 Gy were used, rise in gamma globulin concentration was recordable also following oral administration of antigen. Response of irradiated animals was even more clearly pronounced by secondary reaction of antibody formation, following booster action due to experimental infection with homologous germs. The stimulating effect of irradiation upon gamma globulin levels in blood serum, when oral or parenteral immunisation had taken place, prior to irradiation, has been attributed to reaction of the immune-globulin producing system to the release of tissue proteins or tissue antigens. Immunisation, prior to irradiation, stimulated the immunological system which underwent stronger regeneration, after irradiation, or had obviously acquired higher resistance to radiation.

Animals↗
PubMed1978

The use of cytochalasins in studies on the molecular biology of virus--host cell interactions.

In conclusion, one can say that the cytochalasins--in their brief history of application in virology--have proven to be valuable tools in studies on the molecular biology of virus--host cell interactions. On the other hand, viral systems can be useful in defining the primary sites of action of cytochalasins in certain cells. In interpreting the effects of cytochalasins on virus replication, however, one must take into consideration that the cytochalasins exert a wide variety of alterations in cellular functions. Infections by viruses interfere primarily with the synthesis of host DNA, RNA, and proteins. The experiments reviewed here were carried out with different viruses, different cell lines, and--more important--under very different experimental conditions. Nevertheless, a number of informative observations emerge which provide insight into specific aspects of the interaction of viruses with their host cells, and help us to understand the mode of action of cytochalasins on specific cellular functions: Cytochalasins may decrease or increase the competence of cells for infection by viruses. For the DNA viruses, vaccinia virus and adenovirus, cytochalasin treatment of host cells resulted in a reduced virus yield; whereas for the RNA viruses, poliovirus, parainfluenza virus, and VSV, cytochalasin treatment results in an increased virus yield. The precise mechanism by which cytochalasins exert these effects remain unclear. It is proposed that the cytochalasin-mediated enhancement of cell infectibility for poliovirus--the only system for which this effect has been studied in more detail--is primarily due to a reduction of polypeptide chain initiation. This reduction dramatically amplifies the inherent translational advantage of virus mRNAs over host cell mRNAs, resulting in a relative stimulation of viral mRNA translation. The cytochalasin-mediated sensitization of cells for infection by isolated poliovirus RNA is explainable by a comparable effect on protein synthesis. In this case, cytochalasin may act in part by substituting for the function of a viral protein(s). When cytochalasin B is added to cells which have previously been infected by intact HSV, formation of infectious virus particles is severely inhibited...

Cell Line↗
PubMed1978

[Pathomorphology of radiation sickness in sheep following whole body roentgen irradiation].

Whole-body X-ray treatment was experimentally applied (380 median-line dosage) to eight Merino mutton sheep aged approximately one year. Five of the test animals were lost between 16 and 25 days after irradiation. A great diversity of pathomorphological changes was recorded from organs and tissues, and the most important pathological processes which occurred concomitantly with acute to subacute radiation syndrome of sheep were defective haematopoiesis, septico-toxic processes, haemorrhagic diathesis, and partial epilation. Severe damage to the organs involved in haematopoiesis was one of the primary pathological processes and reflected mainly in lymphopenia, agranulocytosis, and thrombocytopenia, in other words, with lymphopoieses, granulopoiesis, and thrombocytopoiesis particularly involved. Insufficiency of cellular (and humoral) defence would obviously cause germ flooding of the organism, starting from the intestine, and eventually lead to septic intoxication. Haemorrhagic diathesis was found to occur only short of death and is thought to result from thrombocytopenia due to damage to thrombopoiesis as well as from septico-toxic effects upon the blood coagulation and partitioning vascular system. Loss of wool (epilation) was recordable only from neck and shoulder regions, and even there it was on the decline.

Alopecia↗
PubMed1978

[Pathomorphology and pathogenesis of radiation sickness in calves and young cattle following whole body roentgen irradiation].

Here are the most important pathomorphological findings recorded from 14 calves or heads of young cattle following whole-body X-ray treatment (170 R and u50 R median-line dosage): 1. Damage was caused to the haematopoietic system, with the most severe effects on granulopoiesis, thrombocytopoiesis, and lymphopoiesis, but less conspicuous lesion of erythropoiesis. 2. Haemorrhagic diathesis developed together with pneumonia in 86 per cent of all cases, manifested in most of them as severe fibrinous pneumonia and pleuropneumonia (in 75 per cent of the cases) and progressing pericarditis. 3. Liver degeneration occurred to all animals, usually in the form of centrobular liver cell necrobiosis (86 per cent), with most of the cases accompanied by diffuse degenerative hepatoparenchymal damage (80 per cent) as well as by granular degeneration of the myocardium and acute fubulonephrosis, the latter two processes obviously developing only short time before death. 4. Catarrhal as well as fibrinous and circumscribed diphtheroid enteritis developed in 43 per cent of all animals, those which had received a median-line dosage of 170 R. 5. Deficiency in supply was recorded, too, with severe damage to the haematopoietic organs being in the focus of the pathological process. That damage actually was the cause of the haematologically established granulocytopenia or agranulocytosis, thrombocytopenia, and lymphopenia. That was the background against which radiation syndrome of calf could be accompanied by activation of latent or subclinical infection of respiratory organs and the development of severe pneumonia as well as by changes in the intestinal flora leading to the outbreak of enteritis. The collapse of cellular defence mechanisms obviously caused intestinal induction of resorption of bacterial toxins and decomposed tissue products, with the pneumonia-damaged lungs being involved. The results eventually were intoxication with haemodynamic disorders, increase in vascular permeability, and degenerative damage to the parenchyma. Haemorrhagic diathesis was the result of thrombocytopenia and, possibly, endotoxic or toxic damage to the coagulation and blood vessel system. Further pathogenetic aspects relating to the radiation syndrome in calf and young cattle are discussed.

Age Factors↗