Cholesterol homeostasis in the rat with a portacaval anastomosis.

Studies were undertaken to determine the effect of portacaval anastomosis on cholesterol homeostasis in rats fed sucrose/lard under conditions of normal body growth. Four to 6 weeks after portacaval shunt surgery, we found decreases in plasma cholesterol and triglyceride concentrations, total liver weight, and hepatic microsomal protein concentration. Measurements oof hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (EC 1.1.1.34) activity showed decreases in specific activity and total liver activity in portacaval shunt rats, but the enzyme diurnal rhythm remained. Decreased reductase activity in shunted rats was not due to an altered Km for D-HMG-COA, nor was an enzyme inhibitor found in the livers of the portacaval shunt animals. Sterol balance measurements in rats with shunts showed a 22% decrease in whole body cholesterol synthesis rate compared to controls. These metabolic studies, coupled with postmortem data, showed diminished bile acid synthesis, unchanged fecal neutral steroid excretion, and decreased net tissue accumulation of cholesterol during growth. The decreased whole body cholesterol synthesis rate ultimately led to a diminished total carcass cholesterol concentration in the rats with shunts.     

Circulating T-Cell Subsets,Monocytes, and Natural Killer Cells in Peripartum Cardiomyopathy: Results From the Multicenter IPAC Study

Objective

The aim of this work was to evaluate the hypothesis that the distribution of circulating immune cell subsets, or their activation state, is significantly different between peripartum cardiomyopathy (PPCM) and healthy postpartum (HP) women.

Use of DNA probes to identify Trypanosoma congolense and T. simiae in tsetse flies from The Gambia

Species- and strain-specific DNA probes were used to identify patent midgut infections in Glossina morsitans submorsitans and G. palpalis gambiensis captured at four sites in The Gambia. 52% of mature Nannomonas infections and 12% of immature infections were identified. Trypanosoma (Nannomonas) simiae accounted for the majority of identified infections in G.m. submorsitans, indicating the importance of distinguishing this species from the closely related T.(N) congolense when assessing the trypanosomiasis challenge to cattle. Both the savannah and riverine-forest groups of T. congolense were present, although the riverine-forest form was found only in G.p. gambiensis at Pirang, an isolated area of forest. Two-thirds of the samples remain unidentified by probes specific for: Trypanozoon; T. congolense savannah, riverine-forest and Kenya coast forms; T. simiae; and T. vivax, probably owing in part to low numbers of trypanosomes. However, the failure to identify several heavy Nannomonas infections, strongly suggests the presence of a further, as yet unknown, kind of Nannomonas.     

Dynamic tracking of human hematopoietic stem cell engraftment using in vivo bioluminescence imaging

The standard approach to assess hematopoietic stem cell (HSC) engraftment in experimental bone marrow transplantation models relies on detection of donor hematopoietic cells in host bone marrow following death; this approach provides data from only a single time point after transplantation for each animal. In vivo bioluminescence imaging was therefore explored as a method to gain a dynamic, longitudinal profile of human HSC engraftment in a living xenogeneic model. Luciferase expression using a lentiviral vector allowed detection of distinctly different patterns of engraftment kinetics from human CD34+ and CD34+CD38- populations in the marrow NOD/SCID/beta 2mnull mice. Imaging showed an early peak (day 13) of engraftment from CD34+ cells followed by a rapid decline in signal. Engraftment from the more primitive CD34+CD38- population was relatively delayed but by day 36 increased to significantly higher levels than those from CD34+ cells (P <.05). Signal intensity from CD34+CD38-engrafted mice continued to increase during more than 100 days of analysis. Flow cytometry analysis of bone marrow from mice after death demonstrated that levels of 1% donor cell engraftment could be readily detected by bioluminescence imaging; higher engraftment levels corresponded to higher image signal intensity. In vivo bioluminescence imaging provides a novel method to track the dynamics of engraftment of human HSC and progenitors in vivo.     

Early pulmonary infection, inflammation, and clinical outcomes in infants with cystic fibrosis

A thorough understanding of the early natural history of cystic fibrosis (CF) lung disease is critical for the development of effective interventions in the youngest patients. We assessed the evolution of pulmonary infection, inflammation, and clinical course among 40 infants over a 2-year period through annual bronchoalveolar lavage (BAL) for culture and measurements of pro- and anti-inflammatory cytokines, semiannual infant pulmonary function testing, and quarterly clinical evaluations. Both the prevalence of CF pathogens and their density in BAL fluid increased with age. Infants had neutrophilic lower airway inflammation and elevated IL-8 concentrations independent of whether CF pathogens were recovered. Total leukocyte and neutrophil densities and IL-8 concentrations increased with density of CF pathogens in BAL fluid, whether the isolated organism was P. aeruginosa or another pathogen. IL-10 concentrations were similar in CF subjects and non-CF historical controls. Infants generally had suboptimal growth (low weight and height percentiles) and obstructive lung disease (decreased expiratory flows and air trapping). Subjects from whom CF pathogens were isolated at > 10(5) cfu/mL had the worst air trapping and lowest Brasfield chest X-ray scores. Our findings provide a foundation for future studies of early intervention in CF lung disease, including antimicrobial and anti-inflammatory therapy.     

Safety and immunogenicity of a canarypox-vectored human immunodeficiency virus Type 1 vaccine with or without gp120: a phase 2 study in higher- and lower-risk volunteers

Live attenuated viral vectors that express human immunodeficiency virus (HIV) antigens are being developed as potential vaccines to prevent HIV infection. The first phase 2 trial with a canarypox vector (vCP205, which expresses gp120, p55, and protease) was conducted in 435 volunteers with and without gp120 boosting, to expand the safety database and to compare the immunogenicity of the vector in volunteers who were at higher risk with that in volunteers at lower risk for HIV infection. Neutralizing antibodies to the MN strain were stimulated in 94% of volunteers given vCP205 plus gp120 and in 56% of volunteers given vCP205 alone. CD8(+) cytotoxic T lymphocyte cells developed at some time point in 33% of volunteers given vCP205, with or without gp120. Phase 3 field trials with these or similar vaccines are needed, to determine whether efficacy in preventing HIV infection or in slowing disease progression among vaccinees who become infected is associated with the level and types of immune responses that were induced by the vaccines in this study.     

Body weight, plasma insulin, and coronary events with gemfibrozil in the Veterans Affairs High-Density Lipoprotein Intervention Trial (VA-HIT)

BackgroundThe Veterans Affairs High-Density Lipoprotein Intervention Trial (VA-HIT) showed that gemfibrozil significantly reduced major coronary events in men with known coronary heart disease (CHD). To better understand why therapy was especially effective with obesity, diabetes, and hyperinsulinemia, changes in body weight and plasma insulin were determined after 1 year of gemfibrozil or placebo therapy and related to changes in lipids and CHD events.ResultsWith gemfibrozil significantly more subjects lost weight (51.7% versus 38.6%, P < 0.0001) and significantly fewer subjects gained weight (42.5% versus 54.0%, P < 0.0001) than with placebo. Both a greater loss and smaller gain in weight with gemfibrozil were age-related and significant in subjects ≥66 years (median age), but not in younger subjects. Weight change was paralleled by changes in insulin. With gemfibrozil, CHD events were significantly reduced with weight loss (hazard ratio [HR], 0.61; 95% CI, 0.44–0.84; P = 0.002) and, particularly, with diabetes or hyperinsulinemia (HR, 0.53; 95% CI, 0.34–0.83; P = 0.006). In contrast, CHD events were not significantly reduced without weight loss (HR, 0.83; 95% CI, 0.62–1.12; P = 0.22).ConclusionsIn VA-HIT, gemfibrozil resulted in weight loss associated with reductions in insulin. With weight loss gemfibrozil produced a significant reduction in CHD events that did not occur in the absence of weight loss.     

Glutamate receptors and the regulation of steroidogenesis in the human adrenal gland: The metabotropic pathway

Background

l-glutamate is a major excitatory neurotransmitter in the mammalian brain. Glutamate receptors have been reported in the rat adrenal cortex and in human aldosterone-producing adenomas (APA). However, details regarding the expression levels and functions of these receptors in human adrenocortical tissues remain unknown.

Methods

The mRNA levels of glutamate receptors were evaluated by qPCR in: 12 normal adrenal cortex (NAC), 11 APA, and 12 cortisol-producing adenoma (CPA) tissues. Protein localization was evaluated by immunohistochemistry for 15 NAC, 5 idiopathic hyperaldosteronism cases, 15 APA and 15 CPA. H295R cells were treated with angiotensin-II or forskolin alone or combined with the GRM2/3 agonist LY354740.

Results

The level of GRM3 mRNA was higher in APA than in CPA (P = 0.0086) or NAC (P = 0.0022). GRM1, IGLUR2, and IGLUR3 were also detected in adrenocortical tissues. When added to angiotensin-II/forskolin treatments, LY354740 decreased aldosterone and cortisol production in H295R cells.

Conclusions

GRM3 is considered to regulate steroidogenesis in adrenocortical tissues.