Biomedical subjects

C Khatchadourian

Publications and source records attributed to C Khatchadourian.

22 records · Page 2Linked to original sources

PubMed1981

["In vitro" culture of the oviduct of women, rats and rabbits. Preliminary results (author's transl)].

A continuous flow perfusion system which has been improved for the culture of large pieces of tissue, e.g. epididymis and ovarian follicles was tested for the entire oviduct in women, rabbits and rats. The histological properties of the organ were maintained after a day or two of culture; but only in the presence of oestrogens. Progesterone seems to induce a weakness of epithelial cell attachment and these become scattered in the lumen. In women the cultures seemed to be more or less permanently contamined, probably due to commensals, because this problem did not occur with rat or rabbit oviducts.

Animals↗

PubMed1979

Cholinesterases isoenzymes: a comparative study in the skin and plasma.

Acetylcholinesterase (Ache) and pseudocholinesterase (BUche) activities were studied quantitatively in healthy skin by spectrophotometric methods and qualitatively by polyacrylamide gel electrophoresis. The results were compared to those obtained in plasma. The substrates used to reveal enzyme activities were acetylthiocholine (ATC) iodide and butyrylthiocholine (BTC) iodide, respectively. A linear relationship exists between the values of BUche and Ache activities in plasma and those in skin. Six isoenzymes of different electrophoretic mobility were observed in the skin. One of them, which is never found in plasma extracts, appears to be specific to the skin. On gradient gel electrophoresis, with both substrates (ATC and BTC), a single band of enzyme activity, corresponding to a molecular weight of 600,000 was observed. These results suggest that in the skin there is only one enzyme, most probably butyryl cholinesterase, which cleaves BTC somewhat faster than ATC. This methodology, when applied to the study of dermatoses in which abnormalities of cutaneous nerve terminals are suspected, should furnish precise functional pathophysiological details.

Acetylcholinesterase↗

PubMed1978

A rapid quantitative analysis of tyrosine and its oxidation products by tyrosinase.

A new technique based on liquid phase ion exchange chromatography on short column is proposed for quantitative determination of tyrosine and Dopa. alpha-Amino,beta-guanidinopropionic acid is used as an internal standard of coloration. The role of H2O2 and ascorbic acid on tyrosine and Dopa was checked. Ascorbic acid prevents the auto-oxidation of Dopa, H2O2 has no effect on tyrosine but oxidizes Dopa even in the presence of excess ascorbic acid. This method was tested in mushroom tyrosinase, with and without ascorbic acid. Assays performed with tyrosinase from rabbit ocular extracts clearly showed that they do oxidize tyrosine. Reliability of the method is comparable to radioassay.

Alanine↗

PubMedDate not supplied

Catecholamine levels in relation to number of spermatozoa inseminated "in vitro" in the human being.

We tried to understand and to explain why such a high number of sperm cells is necessary for human in vitro fertilization in relation to the possible role of catecholamines. Sperm cells, even washed several times, bring catecholamines (epinephrine, nor-epinephrine and dopamine). When incubated in a suitable medium, with Taurine and reducing agents, the catecholamine level remains constant for 5 hours. The origin of these amines and the positive vs negative effect of "in vitro" insemination with a high number of spermatozoa are discussed.

Catecholamines↗