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Biomedical subjects

G Klein

Publications and source records attributed to G Klein.

At least 1,189 records · Page 66Linked to original sources
PubMed1975

[Effect of naproxen on the semiconservative DNA synthesis and DNA repair of various cell systems].

d-2-(6'Methoxy-2'-naphthyl)-propionic acid (naproxen) in different concentrations was investigated as to its influence on the semiconservative DNA synthesis and DNA repair of human lymphocytes and mouse speen cells. As could be shown, there was a slight diminuation of the DNA synthesis. In view of a desired antiproliferating effect in the treatment of rheumatic diseases this fact could certainly prove useful. Additionally, with a naproxen concentration of 30 ppm, a diminuation of the endonuclease activity in mouse spleen cells could be shown. With naproxen concentrations higher than 60 ppm a slight lowering of the exonuclease and polymerase activities in mouse spleen cells as well as in human lymphocytes were observed. With naproxen in a concentration of 120 ppm, all three enzymes of the excision repair investigated showed a distinct loss of activity. Results of investigations on ligase activity will be presented separately. Under the administration of naproxen, late effects on the genetic material are rather improbable, as long as the substance is not admininstered concomitantly with agents which have a direct effect on the DNA.

Animals↗
PubMed1975

[The effect of so-called basic therapeutics and symptomatically effective antirheumatic drugs on the enzymes of DNA synthesis and DNA repair].

Investigation of DNA-synthesis and DNA-repair are important for evaluating mutagenic effects of drugs. Among the tested non steroidal antirheumatic drugs metiacinic acid, ketoprofene, and azapropazone do not show any effect on these mechanisms. Tolmetin and indometacine, however, inhibit DNA-synthesis only, whereas naproxene, oxyphenylbutazone, and flufenamic acid inhibit both DNA synthesis and repair. Gold does not influence DNA synthesis or repair, D-penicillamine inhibits DNA-synthesis only. However, Chloroquine and metabolised cyclophosphamide respecitvely impair both DNA-synthesis and repair. This effect may be also caused by azathioprine in high dosage. Application of two repair- inhibitors or of one DNA-repair-inhibitor and one directly mutagenic acting drug, e.g. cyclophosphamide, should therefore be avoided.

Apazone↗
PubMed1975

Establishment and characterization of an Epstein-Barr virus (EBC)-negative lymphoblastoid B cell line (BJA-B) from an exceptional, EBV-genome-negative African Burkitt's lymphoma.

An Epstein-Barr virus (EBV)-negative lymphoblastoid cell line (LCL), BJA-B, was established from an African Burkitt's lymphoma (BL) which contained no detectable EBV DNA and did not express the EBV specified antigen EBNA, BJA-B cells grow in typically large, flat clumps. All carry surface-bound immunoglobulins, a B lymphocyte marker, and do not form rosettes with sheep erythrocytes. After infection of BJA-B cells by EBV the infected cells may produce either EBV-determined nuclear antigen (EBNA) or both EBNA and early antigen (EA), depending on the strain of EBV. The homogeneity of the BJA-B cell population with respect to immunological and isoenzyme markers and size suggests a clonal origin of the line. BJA-B is the first EBV-negative LCL established from an African Burkitt's lymphoma and demonstrates that an EBV-independent continuous B cell line can be established "in vitro" from other than leukemia or myeloma cells.

Antigens, Viral↗
PubMed1975

Epstein-Barr virus (EBV)-associated antibody patterns in relation to the deficiency of cell-mediated immunity in patients with Hodgkin's disease.

Sera from unselected and untreated patients with Hodgkin's disease (HD) were examined for antibodies to Epstein-Barr viral (EBV) capsid antigens (VCA). Delayed cutaneous hypersensitivity reactions were carried out with purified tuberculoprotein (PPD). Highly purified blood lymphocytes of the same patients were studied morphologically and classified for cell surface markers. Incorporation of 14C-thymidine was used as a measure of spontaneous DNA synthesis and DNA synthesis after exposure to different concentrations of three mitogens (PHA, Conconavalin A and pokeweed mitogen) and PPD. The distribution of EBV titres was in good agreement with previous reports. Most patients were lymphopenic, due to subnormal levels of T lymphocytes. The lymphocyte stimulation and skin tests showed different degrees of impairment in a considerable number of the patients. The results in 43 patients indicated that a relation exists between the immune defect and the anti-VCA titres. High serological anti-VCA reactivity was related to a poor cutaneous response to PPD, a decreased level of T lymphocytes in the blood and a depression of mitogen-induced DNA synthesis.

Antibodies, Viral↗
PubMed1975

A summing-up.

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Animals↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix III. evaluation of viscera and other tissues.

Histopathological findings in the lungs, livers, bone marrows, small intestines, gonads, kidneys, and other tissues of the four pocket mice (Perognathus longimembris) that survived the Apollo XVII flight were evaluated in the light of their immediate environment and as targest of HZE cosmic ray particles. Results of this study failed to disclose changes that could be ascribed to the HZE particle radiation. Decreased numbers of erythropoietic cells in the bone marrow of the flight mice were probably related to the increased oxygen pressure. The small intestine showed no changes. Ovaries and tests appeared normal. Two of the three surviving male flight mice displayed early stages of spermatogenesis, just as ground-based controls did at the same season. Abnormalities were also not found in the thyroid, parathyroids, adrenals, or kidneys. The status of the juxtaglomerular apparatus could not be evaluated. The lungs exhibited nonspecific slight rections. A variety of incidental lesions were noted in the livers of both the flight mice and their controls. The heart muscle showed nothing that could be regarded as pathological. Sections of skeletal muscle examined were free from significant change.

Adrenal Cortex↗