Pneumococcal Bacteremia Associated With An Infected Central Venous Catheter
complications; cultures; devices; General & Internal Medicine; infected central venous catheter; pneumococcal bacteremia; pneumoniae; Respiratory System; risk-factors; sepsis; Streptococcus; streptococcus-pneumoniae; total parenteral-nutrition; triple-lumen
Dhillon S S; Watanakunakorn C
Chest
2000
2000-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1378/chest.117.5.1515" target="_blank" rel="noreferrer noopener">10.1378/chest.117.5.1515</a>
Regulation of the hamster cholesterol 7 alpha-hydroxylase gene (CYP7A): Prevalence of negative over positive transcriptional control
Biophysics; down-regulation; Biochemistry & Molecular Biology; hmg-coa reductase; messenger-rna levels; Bile acids; protein-kinase-c; cultures; primary; thyroid-hormone; rat hepatocytes; hormonal-regulation; hypophysectomized rats
Cholesterol 7 alpha-hydroxylase plays a crucial role in cholesterol homeostasis. We investigated the regulation of this enzyme in the hamster, a suitable animal model for studying cholesterol metabolism. DNase I hypersensitivity assay revealed the presence of a hypersensitive region in the proximal promoter. Both negative (bile acids, phorbol esters and insulin) and positive (glucocorticoid hormones) effects were mediated through sequences in the region 318 bp upstream of the ATG codon. All-trans-retinoic acid, cAMP, and LDL did not affect transcriptional activity. These findings show that the hamster cholesterol 7 alpha-hydroxylase gene undergoes a predominant negative regulation, as opposed to the rat CYP7A homologous gene. (C) 1996 Academic Press, Inc.
DeFabiani E; Crestani M; Marrapodi M; Pinelli A; Chiang J Y L; Galli G
Biochemical and Biophysical Research Communications
1996
1996-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1006/bbrc.1996.1412" target="_blank" rel="noreferrer noopener">10.1006/bbrc.1996.1412</a>
Hormonal regulation of cholesterol 7 alpha-hydroxylase specific activity, mRNA levels, and transcriptional activity in vivo in the rat
bile-acid biosynthesis; Biochemistry & Molecular Biology; cholesterol; cholesterol 7 alpha-hydroxylase; cultures; gene; gene cyp7; glucocorticoid; hepatic cholesterol; hepatocyte cultures; liver; messenger-rna levels; monolayer-cultures; primary; protein-kinase-c; regulation; sterol 27-hydroxylase; thyroid; thyroid-hormone
In primary cultures of rat hepatocytes, transcription of the cholesterol 7 alpha-hydroxylase gene is induced synergistically by glucocorticoid and thyroid hormones. The objective of the present study was to evaluate the role of glucocorticoid and thyroid hormones in the maintenance of cholesterol 7 alpha-hydroxylase gene expression in vivo. Male Sprague-Dawley rats underwent adrenalectomy (A), thyroidectomy (T), adrenalectomy + thyroidectomy (A + T), hypophysectomy (H), or sham surgery (paired controls). Ten days post surgery, livers were harvested and cholesterol 7 alpha-hydroxylase specific activity, steady-state mRNA levels, and transcriptional activity were determined. Serum corticosterone levels were <2% of paired controls in A, A + T and H rats. Free thyroxine index was <32% of paired controls in rats with T and H. When compared to sham-operated controls, A + T and H led to decreases in cholesterol 7 alpha-hydroxylase specific activities of 44 +/- 8% and 57 +/- 3%, respectively (P < 0.03 and < 0.05). Similar changes were observed in cholesterol 7 alpha-hyroxylase steady-state mRNA levels, which decreased by 43 +/- 10% (P < 0.001) and 56 +/- 19% (P < 0.05), respectively. Cholesterol 7 alpha-hydroxylase transcriptional activity in A + T and H rats decreased by 34 +/- 11% (P < 0.01) and 61 +/- 4% (P < 0.001), respectively. The observed decreases were greater after H than after A + T, suggesting the possibility that another pituitary hormone plays a role in regulation of cholesterol 7 alpha-hydroxylase. Thyroidectomy alone led to a decrease in cholesterol 7 alpha-hydroxylase specific activity of 37 +/- 7% (P < 0.05) and a trend toward decreased steady-state mRNA levels (21 +/- 12%; P = ns). Adrenalectomy did not significantly decrease cholesterol 7 alpha-hydroxylase specific activity or mRNA levels. Neither thyroidectomy nor adrenalectomy alone affected transcriptional activity. We conclude that under physiologic circumstances, full expression of the cholesterol 7 alpha-hydroxylase gene requires synergistic action of glucocorticoids and thyroid hormone.
Pandak W M; Heuman D M; Redford K; Stravitz R T; Chiang J Y L; Hylemon P B; Vlahcevic Z R
Journal of Lipid Research
1997
1997-12
Journal Article
n/a