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Biomedical subjects

Y Lou

Publications and source records attributed to Y Lou.

79 records · Page 5Linked to original sources
PubMed1990

Induction of micronuclei and toxic effects in embryos of pregnant rats treated before implantation with anticancer drugs: cyclophosphamide, cis-platinum, adriamycin.

To evaluate a possible relationship of maternal exposure to anticancer drugs during the preimplantation period to blastopathies and postimplantation embryotoxicity, CD female rats were injected intraperitoneally on day 3 of pregnancy with 15 and 30 mg/kg of cyclophosphamide (CPA), 2 and 4 mg/kg of Adriamycin (ADR), 3 and 6 mg/kg of cis-platinum (Cis-Pt), or with 5 ml/kg of saline. Blastocysts were collected on day 5 of gestation and evaluated for gross morphology, cell number, and micronuclei. Some females were sacrificed on day 21 of pregnancy in order to evaluate postimplantation embryotoxicity. A reduction in cell number/blastocyst was observed only in animals exposed to Cis-Pt 6 mg/kg; vice versa, a dose-related increase of micronuclei and of blastocysts with micronuclei was found in all groups treated with the anticancer agents. A significant increase of postimplantation loss was recorded in the groups treated with high doses of Cis-Pt and ADR, but no clear signs of teratogenicity were observed.

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PubMedDate not supplied

Autoimmune ovarian disease: mechanism of induction and prevention.

Research on murine autoimmune ovarian disease (AOD) models suggests that the following sequence of events operate in prevention and induction of AOD. Potentially pathogenic T cells for oocyte antigens that exist in normal mice are kept in check by regulatory CD25(+) T cells. Oocyte-specific pathogenic T cells are activated when the regulation is lost, as after day 3 thymectomy, or when T cells are stimulated through molecular mimicry. Activated, proinflammatory T cells induce interstitial ovarian inflammation without disruption in ovarian function. Activated T cells also help B cells that respond to endogenous oocyte antigens, to produce oocyte autoantibodies of diversified specificities. Autoantibodies, nonpathogenic in themselves, retarget T cell-mediated inflammation to ovarian follicles resulting in ovarian atrophy and ovarian failure. Future studies should determine the applicability of these findings to human ovarian autoimmunity.

Animals↗
PubMedDate not supplied

No difference in the proportion of insulin receptor exon 11 +/- isoform mRNA in the liver of rats after development of hypertension.

1. There are two functionally different isoforms of the insulin receptor in humans and rats. We hypothesized that a change in their relative proportion could be of relevance to insulin resistance in hypertension. 2. A reverse-transcriptase polymerase chain reaction technique was established for the detection of mRNA for the exon 11+ and exon 11- isoforms and the proportion of each was determined in 3, 6, 9 and 12 week old spontaneously hypertensive rats and Wistar-Kyoto rats, as well as adrenocorticotrophin (ACTH)-induced hypertensive rats and controls. 3. The proportion of the exon 11+ form (approximately 95%) and exon 11- form (approximately 5%) was similar in the liver of all rats studied. 4. We conclude that there is no change in insulin receptor isoform expression in the liver in the models of hypertension studied.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Relative tumor inhibitory and stimulatory activities of BCG vaccine preparations, lots and substrains in a quantitative mouse sarcoma bioassay.

A quantitative in vivo assay for BCG anticancer efficacy was developed to maximize detection of tumor-antagonistic mechanisms. Cultured S180 sarcoma cells admixed with various quantities of Mycobacterium bovis-BCG organisms were injected subcutaneously into CFW Swiss-Webster mice and response was measured as tumor incidence 14 days after injection. Assay of various BCG substrains, lots and killed preparations revealed characteristic patterns of BCG dose-dependent tumor inhibition and enhancement that suggest the existence in the vaccine of multiple active components, the relative concentrations of which vary among cultures. Inhibition of tumor growth by high doses of BCG (greater than 10 micrograms dry weight) was found to be a function of total cell mass and not of the bacterial viability, suggesting that this activity is dependent upon one or more heat-stable components.

Animals↗
PubMedDate not supplied

Initial characterization of an antineoplastic, polysaccharide-rich extract of Mycobacterium bovis BCG, Tice substrain.

A purified hot-water extract from Mycobacterium bovis (BCG vaccine) has been found to have significant antitumor activity against a murine sarcoma in vivo, but not in vitro, suggesting that the active compound is behaving as an immunostimulant. The material, termed PS1, has an average molecular weight of 22.4 kDa, is freely soluble in water, but has low solubility in acetone or ethanol, and is remarkably heat-stable, as is the parent BCG vaccine in terms of high-dose antitumor activity. PS1 contains at least 50% carbohydrate, consisting mainly of glucose, galactose and mannose, and about 10% lipid that may correspond to phosphatidylinositol. It shares chemical and biological properties with an arabinomannan isolated from M. tuberculosis, but it contains only trace quantities of lipoarabinomannan (LAM). Crossed immunoelectrophoresis indicated that PS1 contains the mycobacterial antigen 89, but only a single, non-migrating precipitin arc appeared on immunoelectrophoresis against a standard anti-BCG serum. PS1 appears to be non-toxic in mice up to a dose of 5 mg/kg, while as little as 70 micrograms/kg is sufficient to inhibit tumor formation significantly.

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