61 results match your criteria: "Centre Hospitalier de l'Universite Laval Research Center[Affiliation]"

Effects of TNF-alpha and IFN-gamma on nitric oxide-induced neurotoxicity in the mouse brain.

J Immunol

June 2004

Laboratory of Molecular Endocrinology, Centre Hospitalier de l'Université Laval Research Center, and Department of Anatomy and Physiology, Laval University, Québec City, Québec, Canada.

The present study investigated the interaction between highly reactive gaseous-free radical NO and cytokines that are produced by activated Th-1 cells on the cerebral immune response and neuronal integrity. CD-1 mice received an intrastriatal infusion of different solutions containing the NO synthase inhibitor N(G)-nitro-L-arginine methylester, NO-releasing substance sodium nitroprusside (SNP), IFN-gamma, and/or TNF-alpha. The solution containing both cytokines caused a profound and transient transcriptional activation of numerous genes encoding proinflammatory proteins in microglial/monocytic cells ipsilateral to infusion site.

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Parasitic infections such as leishmaniasis can modulate the life cycle of HIV-1 and disease progression. Coinfection with HIV-1 and Leishmania has emerged as a serious threat in countries where both pathogenic agents are widespread. Although there are numerous clinical reports illustrating the cofactor role played by Leishmania in HIV-1-infected patients, there is still no information on the contribution of Leishmania to the biology of HIV-1 in human lymphoid tissue that is considered a major in vivo site of virus production.

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Glucocorticoids play a fundamental role in protecting the brain during innate immune response.

J Neurosci

July 2003

Laboratory of Molecular Endocrinology, Centre Hospitalier de l'Université Laval Research Center and Department of Anatomy and Physiology, Laval University, Québec, Canada G1V 4G2.

The innate immune system plays a crucial role in protecting the host against infectious microorganisms. An inappropriate control of this system may have profound consequences, because of the maintained production of specific proinflammatory molecules. Glucocorticoids are the most efficient endogenous molecules that provide negative feedback on proinflammatory signaling and gene expression.

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In altering the release of glucocorticoids, ketorolac exacerbates the effects of systemic immune stimuli on expression of proinflammatory genes in the brain.

Endocrinology

December 2002

Laboratory of Molecular Endocrinology, Centre Hospitalier de l'Université Laval Research Center and Department of Anatomy and Physiology, Laval University, Québec, Canada G1V 4G2.

Nonsteroidal antiinflammatory drugs (NSAIDs) are widely used for their antiinflammatory, antipyretic, and analgesic properties. The molecular basis for the therapeutic action of NSAIDs is believed to be in their ability to inhibit cyclooxygenase (COX) activity and thereby blocking the production of prostaglandins. Emerging evidence now suggests that NSAIDs can exert their pharmacological effects through other mechanisms.

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Endotoxemia prevents the cerebral inflammatory wave induced by intraparenchymal lipopolysaccharide injection: role of glucocorticoids and CD14.

J Immunol

September 2002

Laboratory of Molecular Endocrinology, Centre Hospitalier de l'Université Laval Research Center, and Department of Anatomy and Physiology, Laval University, Québec City, Québec, Canada.

There is a robust and transient innate immune response in the brain during endotoxemia, which is associated with a cascade of NF-kappaB signaling events and transcriptional activation of genes that encode TNF-alpha and the LPS receptor CD14. The present study investigated whether circulating LPS has the ability to modulate the cerebral innate immune response caused by an intrastriatal (IS) injection of the endotoxin. We also tested the possibility that CD14 plays a role in these effects and male rats received an intracerebroventricular injection with an anti-CD14 before the IS LPS administration.

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Regulation of the human cyclin-dependent kinase inhibitor p18INK4c by the transcription factors E2F1 and Sp1.

J Biol Chem

August 2002

Molecular Endocrinology and Oncology Research Center, Centre Hospitalier de l'Université Laval Research Center, Centre Hospitalier Universitaire de Quebec, Sainte-Foy, G1V 4G2 Quebec, Canada.

The p18(INK4c) cyclin-dependent kinase inhibitor is an important regulator of cell cycle progression and cellular differentiation. We and others found that overexpressed E2F proteins up-regulate p18 expression. To better understand this phenomenon, we performed a functional analysis of the human p18 promoter.

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The molecular mechanisms underlying the effect of thyroid hormone (T(3)) on neurite outgrowth are unknown. We recently identified the small GC-box binding protein BTEB (basic transcription element-binding protein) as a T(3)-regulated gene in the developing rat brain. BTEB mRNAs are rapidly (by 1 h) up-regulated by T(3) in primary rat embryonic neuronal cultures.

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Perspective: how to make microarray, serial analysis of gene expression, and proteomic relevant to day-to-day endocrine problems and physiological systems.

Endocrinology

June 2002

Laboratory of Molecular Endocrinology, Centre Hospitalier de l'Université Laval Research Center and Department of Anatomy and Physiology, Laval University, Québec, Canada G1V 4G2.

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Human Herpesvirus 6 immediate-early 1 protein is a sumoylated nuclear phosphoprotein colocalizing with promyelocytic leukemia protein-associated nuclear bodies.

J Biol Chem

May 2002

Laboratory of Virology, Laboratory of Viral Immunology, Rheumatology and Immunology Research Center, Centre Hospitalier de l'Université Laval Research Center and Faculty of Medicine, Laval University, Sainte-Foy, Quebec G1V 4G2, Canada.

Immediate-early (IE) proteins are the first proteins expressed following viral entry and play a crucial role in the initiation of infection. We report the cloning and characterization of a full-length IE1 transcript and protein (IE1B) from human herpesvirus 6 (HHV-6) variant B. The IE1B transcript consists of five exons (3720 nucleotides), three of which are coding for the IE1 protein.

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Proinflammatory cytokines released by cells of myeloid lineage have the ability to stimulate different populations of neurons through intermediate molecules released by cells of the blood-brain barrier. The aim of the present study was to verify the hypothesis that prostaglandins (PGs) play a site-specific role in activating selective groups of neurons via a privileged interaction between PG of the E2 type and its EP4 receptor. In a first set of experiments, animals were treated with the inhibitor of PG synthesis ketorolac to determine the endogenous contribution of PG in mediating the neuronal activation and EP4 expression in response to circulating interleukin-1beta(IL-1beta).

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Role of microglial-derived tumor necrosis factor in mediating CD14 transcription and nuclear factor kappa B activity in the brain during endotoxemia.

J Neurosci

May 2000

Laboratory of Molecular Endocrinology, Centre Hospitalier de l' Université Laval Research Center, Department of Anatomy, Laval University, Québec, Canada G1V 4G2.

Systemic injection of the endotoxin lipopolysaccharide (LPS) upregulates the gene encoding CD14 early in the circumventricular organs (CVOs) and later in the brain parenchyma. The present study tested the hypothesis that the parenchymal production of the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) by microglial cells is responsible for triggering CD14 transcription in an autocrine/paracrine loop-like manner. In a first set of experiments, Sprague Dawley rats were killed 1, 3, 6, and 12 hr after an intracerebroventricular administration of recombinant rat TNF-alpha or vehicle solution.

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UGT2B23, a novel uridine diphosphate-glucuronosyltransferase enzyme expressed in steroid target tissues that conjugates androgen and estrogen metabolites.

Endocrinology

December 1999

Laboratory of Molecular Endocrinology, Centre Hospitalier de L'Université Laval Research Center, Laval University, Québec, Canada.

Glucuronidation is widely accepted as a mechanism involved in the catabolism and elimination of steroid hormones from the body. However, relatively little is known about the enzymes involved, their specificity for the different steroids, and their site of expression and action. To characterize the pathway of steroid glucuronidation, a novel uridine diphosphate glucuronosyltransferase (UGT) enzyme was cloned and characterized.

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Visceral adipose tissue and low-density lipoprotein particle size in middle-aged versus young men.

Metabolism

October 1999

Centre Hospitalier de l'Université Laval Research Center, Laval University, Ste-Foy, Quebec, Canada.

Age is associated with increased deposition of visceral adipose tissue. We examined whether this age-related change in regional adipose tissue distribution had an impact on low-density lipoprotein (LDL) particle size. For this purpose, the plasma lipoprotein-lipid profile, including LDL peak particle diameter as determined by gradient gel electrophoresis, was assessed in 38 young men (aged 26.

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Carbonic anhydrase (CA) III is very abundant in type I skeletal muscle, but its function is still debated. Our aims were to examine CA III expression during growth and determine whether the effects of CA inhibition previously observed in adult muscles could be seen in younger rats in which CA III levels are lower. CA III content and activity were measured in soleus muscles from 10- to 100-day-old rats, and the influence of CA inhibitor on fatigue and hexosemonophosphate content was quantified in vitro.

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Sex steroids play a crucial role in the development and differentiation of normal mammary gland as well as in the regulation of breast cancer growth. Local intracrine formation of sex steroids from inactive precursors secreted by the adrenals, namely, dehydroepiandrosterone and its sulfate, may regulate growth and function of peripheral target tissues, including the breast. Both endocrine and paracrine influences on the proliferation of human breast cancer cells are well recognized.

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Although a large proportion of primary human breast cancers express the androgen receptor, and treatment with androgens exerts beneficial effects in women with breast cancer, the role and especially the mechanism of action of androgens in breast cancer development and growth are not well understood. The potential effect of androgens on bcl-2 protooncogene expression was investigated in a human breast cancer cell line whose proliferation is known to be inhibited by androgens. The estrogen-responsive ZR-75-1 cells were grown in the presence or absence of 5alpha-dihydrotestosterone (DHT), alone or in combination with 17beta-estradiol.

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Human and some other primates are unique since their adrenals secrete large amounts of dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S), which are converted into androstenedione (4-dione) and then into potent androgens and estrogens in peripheral tissues, therefore providing autonomous intracrine control to target tissues that can adjust the formation and metabolism of active sex steroids according to local requirements. Knowledge in this area has recently made rapid progress with the elucidation of the structure of most of the tissue-specific cDNAs and genes that encode the steroidogenic enzymes responsible for the transformation of these inactive precursor steroids into androgens and/or estrogens. It is estimated that 30 to 50% of total androgens in men are synthesized in peripheral intracrine tissues from inactive adrenal precursors while, in women, peripheral estrogen formation is even more important, the best estimate being 75% before menopause and 100% after menopause.

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Treatment with the antiestrogen EM-800, at the daily oral dose of 3 microg, 10 microg, 30 microg, or 100 microg for 24 weeks, caused a marked inhibition of uterine and vaginal weight in both intact and ovariectomized mice. Maximal 64% and 41% inhibitions of uterine weight were achieved in intact and ovariectomized animals, respectively. Similar inhibitory effects of EM-800 were observed on vaginal weight with maximal inhibitions of 71% and 35%, in intact and ovariectomized animals, respectively.

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To determine the relative role of the androgenic and/or estrogenic components of the action of dehydroepiandrosterone (DHEA) on the histomorphology and structure of the rat mammary gland, ovariectomized (OVX) female animals received DHEA administered alone or in combination with the pure antiandrogen flutamide or the pure antiestrogen EM-800 for 12 months. We have also evaluated the effect of estradiol (E2) and dihydrotestosterone constantly released from SILASTIC brand silicon implants as well as medroxyprogesterone acetate released from poly(lactide-co-glycolide) microspheres. While 1-yr OVX resulted in a severe atrophy of the mammary gland, treatment of OVX animals with DHEA stimulated lobuloalveolar and ductal growth, as well as the secretory activity of the acinar cells, thus resulting in a lobuloalveolar type of development of the mammary gland.

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The present study compares the effects of tamoxifen and EM-800, both administered at the oral daily dose of 100 microg for 6 months, on the uterus, vagina, and mammary gland in the mouse at histopathological examination. Treatment of intact animals with EM-800 resulted in uterine and vaginal atrophy even greater than that achieved after ovariectomy, while the developmental growth of the mammary gland was completely blocked and serum LH was increased. In ovariectomized animals, treatment with EM-800 decreased uterine and vaginal wt below the values observed in control ovariectomized mice while no significant change was observed on serum LH, thus indicating the lack of estrogenic activity of EM-800.

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Physiological changes in dehydroepiandrosterone are not reflected by serum levels of active androgens and estrogens but of their metabolites: intracrinology.

J Clin Endocrinol Metab

August 1997

Medical Research Council Group in Molecular Endocrinology, Centre Hospitalier de l'Universite Laval Research Center, Le Centre Hospitalier Universitaire de Québec, Canada.

This study analyzes in detail the serum concentration of the active androgens and estrogens, as well as a series of free and conjugated forms of their precursors and metabolites, after daily application for 2 weeks of 10 mL 20% dehydroepiandrosterone (DHEA) solution on the skin to avoid first passage through the liver. In men, DHEA administration caused 175%, 90%, 200% and 120% increases in the circulating levels of DHEA and its sulfate (DHEA-S), DHEA-fatty acid esters, and androst-5-ene-3 beta,17 beta-diol, respectively, with a return to basal values 7 days after cessation of the 14-day treatment. Serum androstenedione increased by approximately 80%, whereas serum testosterone and dihydrotestosterone (DHT) remained unchanged.

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Insulin sensitivity and hemodynamic responses to insulin in Wistar-Kyoto and spontaneously hypertensive rats.

Am J Physiol

October 1996

Hypertension Research and Diabetes Research Unit, Centre Hospitalier de l'Université Laval Research Center, Laval University, Ste-Foy, Quebec, Canada.

The insulin-mediated vasodilator effect has been proposed as an important physiological determinant of insulin action on glucose disposal in normotensive humans. The present study was designed to further examine the acute regional hemodynamic effects of insulin in different vascular beds and to explore the relationships between insulin vascular effects and insulin sensitivity during euglycemic hyperinsulinemic clamps in conscious normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The rats were instrumented with intravascular catheters and pulsed Doppler flow probes to measure blood pressure, heart rate, and regional blood flows.

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OBJECTIVE: The present study was designed to investigate whether a non-pharmacologic intervention program (NPIP) consisting of a weight-lowering diet, a reduction in alcohol consumption and physical training at 50% peak aerobic capacity could enhance the blood-pressure-lowering effect of calcium antagonists in obese sedentary, hypertensive patients. METHODS: Fifty-nine subjects were treatred with 5-10 mg isradipine once daily for 8 weeks and were then randomly allocated to either isradipine monotherapy or isradipine plus NPIP for 20 weeks. Clinic and ambulatory blood pressure were used for assessing the antihypertensive effect obtained in both treatment groups.

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Despite the widely accepted use of prostate specific antigen (PSA) as a marker of prostate cancer, this molecule has not yet been completely characterized. Past studies have well established, however, using both amino acid and cDNA sequencing techniques, that PSA contains 237 amino acids, with a molecular mass of 26,079 Da for the peptide moiety of the molecule. The present study reports analysis of this protein by ion spray mass spectrometry (ISMS) and analysis of its carbohydrate moiety by NMR spectroscopy.

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We compared the antihypertensive activity of DL- and D-nebivolol in patients with essential hypertension on clinic and 24-h ambulatory blood pressure (BP) and during dynamic exercise as well. After a 4-week placebo run-in period, 30 patients (mean age 48 years) were randomly allocated to double-blind treatment with either DL-nebivolol 5 mg or D-nebivolol 2.5 mg once daily for 4 weeks.

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