Evidence for heat shock proteins increased levels in psoriatic patients and in PUVA-treated psoriatic patients preliminary report
International Journal of Medicine, Biology and the Environment 28:1 (2000) 71-74
Abstract:
Heat shock proteins (HSP) are a family of proteins whose synthesis is induced after environmental stresses such as heat, oxidizing agents, and exogenous factors, such as ethanol, smoke, drugs. Also inflammation is characterized by production of HSPs. Though their functions are not fully understood, they act as molecular chaperones facilitating the assembly of multi-protein complexes, and promoting the translocation of polypeptides across cell membranes. Since psoriasis is a frequently observed cutaneous inflammatory disorder, it has been considered a useful inflammatory model to investigate HSPs in this work. In particular HSP 70 and HSP 27 have been studied by Western blotting assay on fibroblast cultures. Biopsies were taken from psoriatic plaques before, during and after PUVA treatment; from non sun-exposed unaffected skin of four psoriatic patients before PUVA-therapy and from non sun-exposed skin of four controls. An increase of expression of HSPs in fibroblast cultures was demonstrated both in psoriatic skin and in particular after PUVA-treatment. The highest levels of HSPs coincided, after PUVA-therapy, in all the patients with the resolution of the lesions. Only slight levels of both HSP 70 and HSP 27 were found in fibroblast cultures derived from uninvolved skin before PUVA-therapy in psoriatic patients. The controls failed to present levels of HPS70, or had unremarkable levels of HSP27. Albeit preliminary, these results suggest that increased levels of HSPs, known to be pro-inflammatory molecules, may characterize the healing phase of an inflammatory disease such as psoriasis.Modulation of proto-oncogene expression by polychlorinated biphenyls in 3T3-L1 cell line.
Journal of toxicology and environmental health. Part A 55:2 (1998) 121-131
Abstract:
The effects of two substituted polychlorinated biphenyls, the 3,4,5,3',4,5' (PCB-169) and the 2,3,4,2',4',5' (PCB-138) forms, were examined on the expression of c-myc, c-jun, c-ras, and jun-b in 3T3-L1 cells. Northern blot analysis demonstrated that the two PCBs, which exhibit a coplanar and di-ortho-substituted configuration, activated these oncogenes differently. PCB-138 markedly induced overexpression of ras, jun, and myc, whereas PCB-169 led to the overexpression of jun-b. High-performance liquid chromatography analysis of the cell samples treated in medium without serum revealed a higher intracellular concentration of the 2,3,4,2',4',5'-hexachlorobiphenyl (hexaCB), whereas the 3,4,5,3',4'5'-hexaCB reached the same concentration in the sonicated samples of cells with or without serum. These results indicated that there was a relationship between PCB structure, bioavailability, and the capacity to stimulate oncogene expression.In Vitro Studies on the Metabolism and Toxicity of Aflatoxin B1 in Primary Cultures of Black Catfish (Ictalurus melas) Hepatocytes.
Alternatives to laboratory animals : ATLA 26:2 (1998) 225-239
Isolation and characterization of RAD51C, a new human member of the RAD51 family of related genes.
Nucleic acids research 26:5 (1998) 1179-1184
Abstract:
The yeast and human RAD51 genes encode strand-transfer proteins that are thought to be involved in both recombinational repair of DNA damage and meiotic recombination. In yeast, the Rad51 family of related proteins also includes Rad55, Rad57 and Dmc1. In mammalian cells, five genes in this family have been identified (HsRAD51, XRCC2, XRCC3, RAD51B/hREC2 and HsDMC1), and here we report the isolation of the sixth member, RAD51C. RAD51C was originally identified by a computer screen of the EST database. A full-length approximately 1.3 kb cDNA clone has been isolated that encodes a protein of 376 aa, having a 18-26% aa identity with other human Rad51 family members. RAD51C includes a previously mapped sequenced-tagged site location near the end of chromosome 17q. The RAD51C transcript is expressed in various human tissues, with highest level of expression in testis, followed by heart muscle, spleen and prostate. Yeast two-hybrid experiments indicate that the Rad51C protein binds to two other members of the Rad51 protein family (Xrcc3 and Rad51B) but not to itself. These findings suggest that Rad51C may function similarly to the yeast Rad55 or Rad57 proteins, rather than as a Rad51 functional homolog.Cryopreservation of isolated trout hepatocytes: Viability and function in primary culture
Cryo-Letters 19:1 (1998) 55-64