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Biomedical subjects

C Hartmann

Publications and source records attributed to C Hartmann.

At least 199 records · Page 11Linked to original sources
PubMed1984

Study of pp60v-src protein kinase activity in synchronized chicken embryo fibroblasts infected with Rous sarcoma virus.

Chicken embryo fibroblast (CEF) cultures, synchronized by the addition of serum to stationary cells, were exposed to Schmidt-Ruppin strain of Rous Sarcoma Virus (SR-RSV) and the appearance of pp60v-src protein kinase activity was examined through the cell cycle. In cells infected either at the beginning or at the end of G1, the onset of pp60v-src protein kinase activity was coincidental, closely following mitosis, with a delay between the infection of cells with SR-RSV and the appearance of protein kinase activity of about 20 and 16 h, respectively. In cells infected during the S phase this delay was 16 h, as observed for late G1 cells. These experiments show that the activity of pp60v-src protein kinase, which cannot be detected before the first mitosis following infection does not depend on G1. The aphidicolin prevented protein kinase activity if added before or at the beginning of S phase, but not if added later, which is presumably related to the inhibition of S phase, required for provirus integration. The use of colcemid, which suppresses cell division, did not inhibit but delayed the appearance of protein kinase activity. These results show that the synthesis of an active oncogene product, such as pp60v-src protein kinase, depends on both S phase and mitosis.

Animals↗
PubMed1984

Aging of cylinders excised from pulp tissues of the ;golden delicious' apple.

Aging cylinders excised from ;Golden Delicious' apple (Pyrus malus L.) pulp, like the intact fruit, exhibit some characteristic phenomena such as rise in respiration (climacteric), ethylene synthesis, enzymic changes, and increase in ribosomes and mRNA. Aging of cylinders of pulp tissues may offer a useful physiological tool for the study of maturation and senescence.

Journal Article↗
PubMed1983

Polyribosomes from aging apple and cherry fruit.

The sequence of events which occurs during the ripening of the Passe-Crassane pear fruit have been previously studied. In this work, we have investigated the ripening of another climacteric fruit (Pyrus malus L. cv Golden Delicious) and of a nonclimacteric fruit (Prunus avium L. cv Bigarreau Napoléon). We show that both climacteric fruits exhibit the same preclimacteric sequence of events. Differences exist, however, between the Golden Delicious apple and the Passe-Crassane pear in that the protein synthesis capacity of the two fruits is not the same during the over-ripening period. On the other hand, a nonclimacteric fruit, the Bigarreau Napoléon cherry, does not show an increase in its protein synthesis capacity during the over-ripening period.

Journal Article↗
PubMed1983

An atypical Aspergillus flavus from a case of bronchopulmonary aspergilloma. A contribution to the cultural and serological diagnosis of A. flavus infections.

A slow-growing, non-pigmented hyphomycete was isolated from sputum and a fungus ball removed at autopsy from the lung. The patient, an alcoholic, also suffered from cirrhosis and primary carcinoma of the liver. The atypical and otherwise non-recognizable isolate showed a growth typical of Aspergillus flavus when cultured on sterilized peanuts. This observation indicates the diagnostic significance of such strains which have become atypical, as etiologic agents and sources of antigen. Serologically, the antigen of the atypical strain proved to be stronger than that of a typical A. flavus strain. In view of the simultaneous presence of the liver carcinoma and the absence of aflatoxin production by the atypical strain, the possible role of chronic colonization of the lung by A. flavus is discussed.

Aflatoxins↗
PubMed1982

[Changes, during a synchronous cell cycle, of the level of incorporation of 5-bromodeoxyuridine into DNA of chick embryo fibroblasts].

The determination of the buoyant density of synchronously dividing Chick embryo fibroblast DNA, substituted at various times during the cell cycle by 5-bromodeoxyuridine (BrdU), has been carried out by means of analytical neutral CsCl banding. It has been shown that the buoyant density of BrdU-substituted DNA, duplicated during the first half of S phase, was 0.010 g/ml higher than that of BrdU-substituted DNA duplicated during the second half of S phase. That may reflect a preferential incorporation of the analogue at the beginning of S phase. This peculiar pattern of incorporation would be responsible for the observed inhibition of cell transformation occurring when fibroblasts, infected by Rous sarcoma virus, are grown in the presence of the analogue.

Animals↗
PubMed1982

Studies on the development of extra-endothelial and intra-endothelial pigment deposits by means of direct and indirect contact specular microscopy of the cornea.

Retro-corneal pigmentation as a result of primary (degenerative) or secondary (inflammatory, traumatic) pigment dispersion represents one of the most frequent findings in specular microscopy. The analysis of the pigment distribution patterns of dense deposits like those in Krukenberg spindle (KS) permits the postulation of a hypothesis concerning the development of such typical corneal pigmentations and the pigmentation of the posterior surface of the cornea in general, such as diffuse pigment dispersion (Vogt 1930), which is seen frequently. In a particular case of double KS with extreme myopia and cataract, endothelial morphological findings were documented over a period of 1 year, both before and after cataract extraction. This was done by means of contact and non-contact specular microscopy in various spindle areas. The morpho-metric studies (cell density/mm2; cell perimeter; largest smallest and average cell diameter; specific surface; horizontal and vertical cell orientation) were carried out automatically using a computerised video image analyser. The changes in the area of densest pigmentation in the KS centre confirm the histologically proven capacity of pigment phagocytosis by human corneal endothelium. These findings indicate that in specular microscopy, both endothelial cellular surface modifications and intra-cellular changes are documentable. The extracellular pigment deposits can also be shown by means of 'indirect' specular microscopy, the optical principle of which is described.

Aged↗
PubMed1982

Polyribosomes from Pear Fruit: II. CHANGES OCCURRING IN PULP TISSUES DURING RIPENING AND SENESCENCE.

Detailed analyses of polysome profiles from lyophilized pulp tissues of pear fruits (Pyrus communis L. cv. Passe-Crassane) at different stages of ripening and senescence, and estimates of the amount of polysomal-associated mRNA, lead to the conclusions that during senescence (ripening), the ripening and the over-ripening processes can clearly be separated and respectively linked to the first and the second increase in the large mRNA species. Ethylene synthesis which occurs at the beginning of a normal ripening at 15 degrees C after a cold storage or an ethephon treatment is related to an increase in mRNA and ribosomal material found only in pulp tissues. Finally, we suggest that in the pear fruit, the sequence of events which occurs during senescence (ripening) is initiated by two systems which regulate ethylene biogenesis, and that the first system is efficient only at low temperatures (from 0 to 4 degrees C).

Journal Article↗