Effect of TEX-OE(®) treatment on the development of heat shock proteins in commercial broiler chicks and the impact on performance indicators in the grow-out period.

Heat shock proteins (HSPs) are highly conserved proteins, shown to protect organisms against physical and physiological stress. TEX-OE(®) is a patented total extract of the fruit of Opuntia ficus indica, which has been demonstrated to accelerate the development of HSPs in several animal species. One-day-old commercial broiler chicks were treated with TEX-OE(®); HSP was measured by enzyme-linked immunosorbent assay (ELISA), and a large commercial field trial investigated key performance indicators (KPIs) in treated versus untreated controls chicks. TEX-OE(®) significantly increased HSP concentrations in treated chicks versus controls. Final cumulative mortality, liveweight and percentage factory-rejects were better than in controls. The accelerated HSP response may enable chicks to cope with early stressors, which is reflected in improved KPIs.

Transient expression of lysyl oxidase by liver myofibroblasts in murine schistosomiasis.

BACKGROUND: Murine schistosomiasis provides an experimental model of reversible fibrosis. The lysyl oxidase catalyzes the first step of collagen and elastin enzymatic cross-linking and appears to be a crucial factor in stabilizing the neosynthesized extracellular matrix in the liver. EXPERIMENTAL DESIGN: A cDNA probe encoding a portion of the murine lysyl oxidase was cloned, and antibodies were raised against the corresponding recombinant peptide expressed as a fusion protein. Both tools were used to examine the expression of the lysyl oxidase mRNAs and peptides, all within granulomas and cells extracted from infected liver. RESULTS: Transient up-regulation of two dominant 4.5 kb and 5.5 kb transcripts was observed among four mRNAs hybridizing with the lysyl oxidase cDNA probe during the development of granulomas. An identical time course was obtained for alpha 1(I) procollagen messenger expression. The lysyl oxidase expression was observed in type I collagen producing cells mainly localized at the periphery of fibroinflammatory granulomas and it disappeared in late granulomas. The lysyl oxidase and type I collagen expressing cells, located within granulomas, exhibited the characteristics of myofibroblasts, as judged by their expression of alpha-smooth muscle actin and desmin and by their ultrastructural morphology. Four antigenically related peptides were immunopurified from an enriched preparation of myofibroblast-like cells extracted from infected mouse liver. Two of these peptides had the molecular weight of prolysyl oxidase (50,000) and activated lysyl oxidase (32,000). The two others (28,000 and 66,000) might correspond to cleavage product or dimeric form respectively. CONCLUSIONS: This study demonstrates that the lysyl oxidase was transiently up-regulated at the transcriptional level parallely to alpha(1)I procollagen within developing granulomas. Myofibroblasts are involved in the expression of the lysyl oxidase which may be secreted as a proenzyme and an activated enzyme.

New specific markers of human and mouse fibroblasts.

The expression of different lineage-specific markers was examined on tissue-derived fibroblast cultures in three species (mouse, rat and human), using indirect immunofluorescence or labelled streptavidin-biotin techniques. Smooth muscle cells and a human monocyte-like cell line (U 937) were used as controls. Five monoclonal antibodies against human fibroblast epitopes et two against mouse fibroblasts were selected during this screening on cell cultures. Three surface markers (Thy-1, 6-19 and 1B10) and, particularly, one (5B5) cytoplasmic marker of human fibroblasts were suitable for labeling frozen, but not paraffin-embedded, tissue sections. Unfortunately, the two mouse fibroblast markers appeared of difficult and limited interest for this histopathologic strategy.

[Effects of 3,5,3'-triiodo-L-thyronine on the enzymes responsible for the metabolism of xenobiotics in the rat after increase in the dietary supply of cholesterol]. / Effets de la 3,5,3'-triiodo-L-thyronine sur les enzymes responsables du métabolisme des xénobiotiques chez le Rat aprés augmentation de l'apport alimentaire en cholestérol.

A cholesterol rich diet fed to rats was found to increase the cytochrome P 450 content in hepatic microsomes. Furthermore, the variations of the same parameters promoted by 3,5,3'-triiodo-L-thyronine were strongly reduced in cholesterol supplemented rats. Cholesterol prevented the inducing effects of phenobarbital but did not oppose its decreasing effect on maximal fluorescence of ANS and PNA introduced into the microsome suspensions.