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Biomedical subjects

P Mulsant

Publications and source records attributed to P Mulsant.

23 records · Page 2Linked to original sources

Long-term multiplication of the Chinese hamster ovary (CHO) cell line in a serum-free medium.

A new synthetic medium (referred to as GC3) that supports the growth of the Chinese hamster ovary cell line has been developed. It is composed of a 1:1 mixture of Ham's F12 and modified Eagle's minimum essential (MEM.S) mediums supplemented with transferrin (10 micrograms/ml), insulin (80 mU/ml), and selenium (1 X 10(-7) M). Other more simple supplementations of our basal medium MEM.S/F12 (transferrin + insulin, transferrin + selenium, ferrous iron + selenium) also give good cell growth responses. Fibronectin or serum pretreatment is not needed for cellular attachment and spreading. Our culture system is characterized by a continuous serum-free cultivation (more than 200 doublings), a clonal growth, a high density proliferation, and a rapid growth rate near that of cells in serum-supplemented medium.

Animals↗

Selection and preliminary characterization of cycloleucine-resistant CHO cells affected in methionine metabolism.

Cycloleucine is in vivo a potent inhibitor of S-adenosylmethionine (SAM) biosynthesis and subsequent methylation reactions in somatic mammalian cells. Cycloleucine-resistant (CLr) clones were isolated from CHO cells by single-step selection. Their phenotype was stable when they were grown in the absence of drug. These clones appeared randomly in cultures at the frequency of 5 x 10(-6)/cell/generation, as determined by a fluctuation test. EMS mutagenesis did not significantly increase this frequency. The cycloleucine-resistant phenotype was codominant in intraspecific hybrids. Cycloleucine-resistant clones showed increased SAM pools; on the contrary, methionine pools were not significantly affected in these clones when compared to the wild-type cells. This increased SAM production was correlated with an increase of methionine adenosyltransferase (MAT) SPECIFIC ACTIVITY IN RESISTANT CLONES UNDER VARIOUS GROWm. The mechanism of posttranscriptional control of MAT biosynthesis was not affected in the cycloleucine-resistant clones nor were the kinetic properties of the enzyme modified. The genetic or epigenetic origin of this resistance mechanism is discussed.

Amino Acids↗

Different levels of human intervention in domestic rabbits: effects on genetic diversity.

The effects of human interaction on domestic rabbits were evaluated through the analysis of animals (up to 267) belonging to fancy breeds (22), a commercial breed (1), and selected strains (2). Microsatellite loci and mtDNA polymorphism revealed that the genetic pool of domestic rabbits studied only originated from that available in France. The good conservation of the original diversity was probably ensured through the multiplicity of samplings from wild populations. Selected strains, because of the breeding strategy, keep a fairly high level of diversity compared to other breeds.

Animal Husbandry↗

A new device for the treatment of pleural malignancies: intrapleural chemohyperthermia preliminary report.

The prognosis of malignant pleural tumors remains extremely unfavorable. The aim of this study is to evaluate the combination of intrathoracic intrapleural chemotherapy and intrapleural hyperthermia (ITCH) in these diseases. Under anesthesia, 5 men were studied. After pleurectomy for mesothelioma (3/5) or adenocarcinoma (2/5), ITCH is carried out for over 60 min, either with mitomycin C (4/5) or cisplatin (1/5). No pre- or postoperative death occurred. The maximal pleural temperature is 42.6 degrees C. The blood level of mitomycin C never reached the systemic toxic level. All the patients were discharged from the surgical ward, 3 are still alive 15 months later. Therefore, ITCH appears to be a safe and reliable therapy.

Adenocarcinoma↗