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The CCR5 coreceptor may be a therapeutic target to block HIV infection. HIV-1–infected patients who had received previous antiretroviral treatment were enrolled in one of two phase 3, placebo-controlled, double-blind international studies of treatment with maraviroc (a CCR5 antagonist). Maraviroc significantly lowered the HIV-1 viral load and increased the CD4 cell count at 48 weeks. The CCR5 coreceptor may be a therapeutic target to block HIV infection. In two studies, maraviroc (a CCR5 antagonist) significantly lowered the HIV-1 viral load and increased the CD4 cell count at 48 weeks. For the past decade, treatment of human immunodeficiency virus type 1 (HIV-1) has consisted of a multiple-drug regimen targeting one or more of three HIV-1 proteins: reverse transcriptase, protease, and the glycoprotein envelope subunit gp41. 1 Although these antiretroviral combinations are successful in suppressing viral replication and delaying disease progression, drug resistance and toxic effects may occur. 2 – 4 There is therefore a need for better-tolerated, convenient antiretroviral agents with reduced toxicity and activity against multidrug-resistant viruses. Agents with novel mechanisms of action provide options for patients with drug-resistant virus. 4 CC chemokine receptor 5 (CCR5) is an attractive therapeutic target, since people . . .

Background. There is a need to prevent or minimize bone loss associated with antiretroviral treatment (ART) initiation. We compared maraviroc (MVC)- to tenofovir disoproxil fumarate (TDF)–containing ART. Methods. This was a double-blind, placebo-controlled trial. ART-naive subjects with human immunodeficiency virus type 1 RNA load (viral load [VL]) >1000 copies/mL and R5 tropism were randomized to MVC 150 mg or TDF 300 mg once daily (1:1), stratified by VL <100 000 or ≥100 000 copies/mL and age <30 or ≥30 years. All subjects received darunavir 800 mg, ritonavir 100 mg, and emtricitabine 200 mg daily. Dual-energy X-ray absorptiometry scanning was done at baseline and week 48. The primary endpoint was percentage change in total hip bone mineral density (BMD) from baseline to week 48 in the as-treated population. Results. We enrolled 262 subjects. A total of 259 subjects (130 MVC, 129 TDF) contributed to the analyses (91% male; median age, 33 years; 45% white, 30% black, 22% Hispanic). Baseline median VL was 4.5 log10 copies/mL and CD4 count was 390 cells/μL. The decline in hip BMD (n = 115 for MVC, n = 109 for TDF) at week 48 was less with MVC (median [Q1, Q3] of −1.51% [−2.93%, −0.11%] vs −2.40% [−4.30%, −1.32%] for TDF (P<.001). Lumbar spine BMD decline was also less with MVC (median −0.88% vs −2.35%; P<.001). Similar proportions of subjects in both arms achieved VL ≤50 copies/mL in as-treated and ITT analyses. Conclusions. MVC was associated with less bone loss at the hip and lumbar spine compared with TDF. MVC may be an option to attenuate ART-associated bone loss. Clinical Trials Registration. NCT01400412.

In this large clinical trial, the angiotensin-receptor blocker valsartan reduced the risk of diabetes in patients with impaired glucose tolerance. However, the effect was small, and there was no reduction in the rate of cardiovascular events. Thus, impaired glucose tolerance is probably best managed with lifestyle intervention. In this large clinical trial, the angiotensin-receptor blocker valsartan reduced the risk of diabetes in patients with impaired glucose tolerance. However, the effect was small, and there was no reduction in the rate of cardiovascular events. Patients with impaired glucose tolerance have an increased risk of type 2 diabetes mellitus and cardiovascular disease. 1 – 3 Interventions that might reduce the incidence of diabetes and associated rates of death and complications from cardiovascular causes in such patients are therefore of importance. 3 Several trials have shown that lifestyle modification, including increased physical activity and weight loss, reduces the risk of diabetes, although these trials did not evaluate cardiovascular outcomes. 3 – 8 Certain drugs, including metformin, acarbose, and rosiglitazone, also reduce the incidence of diabetes, although their effect on cardiovascular events is uncertain. 6 , 9 , 10 Another pharmacologic approach to reducing the . . .

The bifunctional catalyst Ru/H was prepared by equal volume impregnation method and applied to the study of the kinetics of benzene hydroalkylation reaction. The reaction order of 1 for benzene and 1.94 for H.sub.2 ( [Formula omitted]) was obtained by fitting the kinetic experimental data first. Then a kinetic model conforming to the Eley-Rideal (E-R) mechanism was developed based on the types of adsorbates on different active centers of the solid catalyst, and the main mechanism was that the benzene in the adsorbed state was partially hydrogenated to produce cyclohexene, which was not desorbed from the active centers. Some of it was further hydrogenated to produce cyclohexane, and some was alkylated with benzene in the bulk phase to produce cyclohexylbenzene. The reaction rate control step was the alkylation of benzene and cyclohexene. The model parameters were calculated using a genetic algorithm. The model was tested to be able to describe the reaction mechanism of benzene hydroalkylation well and to provide guidance for process optimization.

Transmembrane anion transporters (anionophores) have potential for new modes of biological activity, including therapeutic applications. In particular they might replace the activity of defective anion channels in conditions such as cystic fibrosis. However, data on the biological effects of anionophores are scarce, and it remains uncertain whether such molecules are fundamentally toxic. Here, we report a biological study of an extensive series of powerful anion carriers. Fifteen anionophores were assayed in single cells by monitoring anion transport in real time through fluorescence emission from halide-sensitive yellow fluorescent protein. A bis-( p -nitrophenyl)ureidodecalin shows especially promising activity, including deliverability, potency and persistence. Electrophysiological tests show strong effects in epithelia, close to those of natural anion channels. Toxicity assays yield negative results in three cell lines, suggesting that promotion of anion transport may not be deleterious to cells. We therefore conclude that synthetic anion carriers are realistic candidates for further investigation as treatments for cystic fibrosis. Synthetic anion transporters that replace the activity of defective anion channels have been proposed as treatments for cystic fibrosis; however, it remains uncertain whether such molecules are fundamentally toxic. A series of bis- and tris-(thio)ureas capable of transporting anions have now been tested in cells expressing halide-sensitive yellow fluorescent protein. One bis-urea compound proved especially effective while showing almost no toxicity.

BackgroundMaraviroc, a CCR5 antagonist, is active against R5 but not X4 or dual- or mixed-tropic strains of human immunodeficiency virus type 1 (HIV-1). A phase 2b study was conducted to determine the safety and efficacy of maraviroc in combination with optimized background therapy in treatment-experienced patients infected with dual- or mixed-tropic HIV-1 MethodsTreatment-experienced patients with an HIV-1 RNA level ⩾5000 copies/mL who had received ⩾3 classes of drugs and/or were infected with virus resistant to 2 drug classes and were infected with non-R5 HIV-1 were randomized to receive optimized background therapy plus maraviroc (once or twice daily) or placebo. The primary end point was change in HIV-1 RNA level from baseline to 24 weeks ResultsAmong 167 patients infected with dual- or mixed-tropic HIV-1, baseline mean HIV-1 RNA levels were >5 log10 copies/mL and median CD4+ cell counts were <50 cells/μL. From baseline to 24 weeks, patients who received placebo demonstrated a mean decrease in HIV-1 RNA levels of 0.97 log10 copies/mL, compared with mean decreases of 0.91 and 1.20 log10 copies/mL for those who received maraviroc once (P=.83) or twice (P=.38) daily, respectively. Mean increases in CD4+ cell counts from baseline were 36 cells/μL for patients who received placebo, 60 cells/μL among patients who received maraviroc once daily, and 62 cells/μL among patients who received maraviroc twice daily. The incidences of serious adverse events were similar among groups ConclusionsIn this exploratory study involving extensively treatment-experienced patients with advanced, non-R5 HIV-1 infection, neither superiority nor noninferiority was statistically demonstrated for either maraviroc dosage compared with placebo at 24 weeks of treatment Trial registrationClinicaltrials.gov identifier NCT00098748

Blocking lymphocyte chemotaxis with an oral inhibitor of the CCR5 receptor was associated with reduced incidence of visceral graft-versus-host disease (GVHD) in patients undergoing reduced-intensity conditioned allogeneic hematopoietic stem-cell transplantation. Acute graft-versus-host disease (GVHD) is a major cause of death and complications after allogeneic hematopoietic stem-cell transplantation (HSCT). The condition occurs in 30 to 50% of patients receiving HLA-matched transplants from a related donor and in 50 to 70% of those receiving transplants from an unrelated donor. 1 The pathogenesis of GVHD is multifactorial, but ultimately, donor-derived T cells recognize recipient antigens as foreign, resulting in activation, expansion, and cytokine release and leading to destruction of host tissues. 2 Current therapies for GVHD target T cells and cytokines, often antagonize T-cell–mediated graft-versus-tumor responses, and delay immune reconstitution. 3 Preventing GVHD without intensive immune . . .

The ability of short-acting insulin secretagogues to reduce the risk of diabetes or cardiovascular events in people with impaired glucose tolerance is unknown. In a double-blind, randomized clinical trial, we assigned 9306 participants with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors to receive nateglinide (up to 60 mg three times daily) or placebo, in a 2-by-2 factorial design with valsartan or placebo, in addition to participation in a lifestyle modification program. We followed the participants for a median of 5.0 years for incident diabetes (and a median of 6.5 years for vital status). We evaluated the effect of nateglinide on the occurrence of three coprimary outcomes: the development of diabetes; a core cardiovascular outcome that was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure; and an extended cardiovascular outcome that was a composite of the individual components of the core composite cardiovascular outcome, hospitalization for unstable angina, or arterial revascularization. After adjustment for multiple testing, nateglinide, as compared with placebo, did not significantly reduce the cumulative incidence of diabetes (36% and 34%, respectively; hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15; P=0.05), the core composite cardiovascular outcome (7.9% and 8.3%, respectively; hazard ratio, 0.94, 95% CI, 0.82 to 1.09; P=0.43), or the extended composite cardiovascular outcome (14.2% and 15.2%, respectively; hazard ratio, 0.93, 95% CI, 0.83 to 1.03; P=0.16). Nateglinide did, however, increase the risk of hypoglycemia. Among persons with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors, assignment to nateglinide for 5 years did not reduce the incidence of diabetes or the coprimary composite cardiovascular outcomes. (ClinicalTrials.gov number, NCT00097786.)

The CCR5 chemokine receptor acts as a co-receptor for HIV-1 viral entry. Here we report the 2.7 angstrom-resolution crystal structure of human CCR5 bound to the marketed HIV drug maraviroc. The structure reveals a ligand-binding site that is distinct from the proposed major recognition sites for chemokines and the viral glycoprotein gp120, providing insights into the mechanism of allosteric inhibition of chemokine signaling and viral entry. A comparison between CCR5 and CXCR4 crystal structures, along with models of co-receptor—gp120-V3 complexes, suggests that different charge distributions and steric hindrances caused by residue substitutions may be major determinants of HIV-1 co-receptor selectivity. These high-resolution insights into CCR5 can enable structure-based drug discovery for the treatment of HIV-1 infection.

In this work the distribution coefficients (D) of polonium between 0.1 mol dm.sup.-3 TOPO/toluene; TOPO/cyclohexane; TBP/toluene and TBP/cyclohexane and aqueous solutions of inorganic acids (HCl, HNO.sub.3, H.sub.2SO.sub.4 and H.sub.3PO.sub.4) were determinated. The molarities of inorganic acids were between 0.5 and 12.0 mol dm.sup.-3.sub.. The activity of extracted Po-209 was measured by means of liquid scintillation counting. The best result was obtained for TOPO/toluene and 2 mol dm.sup.-3 H.sub.2SO.sub.4 system (D = 62 ± 9). The most stable conditions of extraction were found for TOPO/toluene-HCl system.