by
Mohamed Ali Ibrahim;
MinKyun Na;
Joonseok Oh;
Raymond Schinazi;
Tami R. McBrayer;
Tony Whitaker;
Robert J. Doerksen;
David J. Newman;
Louis G. Zachos;
Mark T. Hamann
One in five of the world's plant species is threatened with extinction according to the 2010 first global analysis of extinction risk. Tilman et al. predicted a massive ecological change to terrestrial plants within the next 50-100 y, accompanied by an increase in the number of global plant species facing extinction [Tilman D, et al. (2001) Proc Natl Acad Sci USA 98(10):5433-5440]. Most of the drugproducing plant families contain endangered species never previously studied for their utility to human health, which strongly validates the need to prioritize protection and assessment of these fragile and endangered groups [Zhu F, et al. (2011) Proc Natl Acad Sci USA 108(31):12943-12948] . With little prior attention given to endangered and rare plant species, this report provides strong justification for conservation of the rare plant Diplostephium rhododendroides Hieron., as well as other potential drug-producing endangered species in this and other groups.
by
Marilyn Ader;
W. Timothy Garvey;
Lawrence S Phillips;
Charles B. Nemeroff;
Georges Gharabawi;
Ramy Mahmoud;
Andrew Greenspan;
Sally A. Berry;
Dominique L. Musselman;
Jacqueline Morein;
Young Zhu;
Lian Mao;
Richard N. Bergman
Objective: Atypical antipsychotics induce weight gain and are linked to increased diabetes risk, but their relative impact on factors that elevate disease risk are unknown.
Methods: We performed a 6-month, randomized, double-blind study to evaluate the effects of risperidone and olanzapine in patients with schizophrenia. At baseline and weeks 6 and 24, we quantified: (1) total adiposity by DEXA, (2) visceral adiposity by abdominal CT, and (3) insulin sensitivity (SI) and (4) pancreatic function ("disposition index", DI) by intravenous glucose tolerance test.
Results: At baseline, groups (risperidone: n = 28; olanzapine: n = 31) were overweight or obese by body mass index (risperidone: 28.4 ± 5.4, olanzapine: 30.6 ± 7.0 kg/m2). Both drugs induced weight gain (p < 0.004). Total adiposity was increased by olanzapine at 6 weeks (p = 0.0006) and by both treatments at 24 weeks (p < 0.003). Visceral adiposity was increased by olanzapine and risperidone by 24 weeks (p < 0.003). SI did not deteriorate appreciably, although a downward trend was observed with risperidone. Given known ethnic differences in adiposity and SI, we performed secondary analysis in African American and Hispanic subjects. In this subset, olanzapine expanded both total and visceral adiposity (p < 0.02); no increase was observed with risperidone. There were modest downward trends for SI with both treatments. By week 24, olanzapine-treated subjects exhibited diminished DI (p = 0.033), indicating inadequate pancreatic compensation for insulin resistance.
Conclusions: This is the first prospective study in psychiatric patients that quantified antipsychotic effects on the multiple metabolic processes that increase diabetes risk. Results indicate that ethnic minorities may have greater susceptibility to antipsychotic-induced glucoregulatory complications.
by
Andrew W. Bergen;
Martha Michel;
Denise Nishita;
Ruth Krasnow;
Harold S. Javitz;
Karen Conneely;
Christina N. Lessov-Schlaggar;
Hyman Hops;
Andy Z. X. Zhu;
James W. Baurley;
Jennifer B. McClure;
Sharon M. Hall;
Timothy B. Baker;
David V. Conti;
Neal L. Benowitz;
Caryn Lerman;
Rachel F. Tyndale;
Gary E. Swan
The Nicotine Metabolite Ratio (NMR, ratio of trans-3'-hydroxycotinine and cotinine), has previously been associated with CYP2A6 activity, response to smoking cessation treatments, and cigarette consumption. We searched for drug metabolizing enzyme and transporter (DMET) gene variation associated with the NMR and prospective abstinence in 2,946 participants of laboratory studies of nicotine metabolism and of clinical trials of smoking cessation therapies. Stage I was a meta-analysis of the association of 507 common single nucleotide polymorphisms (SNPs) at 173 DMET genes with the NMR in 449 participants of two laboratory studies. Nominally significant associations were identified in ten genes after adjustment for intragenic SNPs; CYP2A6 and two CYP2A6 SNPs attained experiment-wide significance adjusted for correlated SNPs (CYP2A6 P<inf>ACT</inf>=4.1E-7, rs4803381 P<inf>ACT</inf>=4.5E-5, rs1137115, P<inf>ACT</inf>=1.2E-3). Stage II was mega-regression analyses of 10 DMET SNPs with pretreatment NMR and prospective abstinence in up to 2,497 participants from eight trials. rs4803381 and rs1137115 SNPs were associated with pretreatment NMR at genome-wide significance. In post-hoc analyses of CYP2A6 SNPs, we observed nominally significant association with: abstinence in one pharmacotherapy arm; cigarette consumption among all trial participants; and lung cancer in four case:control studies. CYP2A6 minor alleles were associated with reduced NMR, CPD, and lung cancer risk. We confirmed the major role that CYP2A6 plays in nicotine metabolism, and made novel findings with respect to genome-wide significance and associations with CPD, abstinence and lung cancer risk. Additional multivariate analyses with patient variables and genetic modeling will improve prediction of nicotine metabolism, disease risk and smoking cessation treatment prognosis.
SUMMARY
Hepatitis C virus (HCV) causes significant morbidity and mortality worldwide with nearly 3% of the world population infected by this virus. Fortunately, this virus does not establish latency, and hence it may be possible to eradicate it. HCV is strongly associated with liver cirrhosis and hepatocellular carcinoma and is currently treated with pegylated interferon-α (peg-IFN-α) and ribavirin. Unfortunately, these limited treatment options often produce significant side effects, and currently, complete eradication of virus with combined drug modalities has not yet been achieved for the majority of chronically HCV-infected individuals. Restricted treatment options, lack of a universal cure for HCV and the link between chronic infection, liver cirrhosis and hepatocellular carcinoma necessitate design of novel drugs and treatment options. Understanding the relationship between the immune response, viral clearance and inhibition of viral replication with pharmacology-based design can ultimately allow for complete eradication of HCV. This review focuses upon significant novel preclinical and clinical specifically targeted antiviral therapy (STAT-C) drugs under development, highlights their mechanism of action, and discusses their impact on systemic viral loads and permanent clearance of infection.
Judicious modifications to the structure of the previously reported HCV NS5A inhibitor 1, resulted in more potent anti-HCV compounds with similar and in some cases improved toxicity profiles. The synthesis of 19 new NS5A inhibitors is reported along with their ability to block HCV replication in an HCV 1b replicon system. For the most potent compounds chemical stability, stability in liver microsomes and inhibition of relevant CYP450 enzymes is also presented.
by
Stephen T. Turner;
Eric Boerwinkle;
Jeffrey R. O'Connell;
Kent R. Bailey;
Yan Gong;
Arlene B Chapman;
Caitrin W. McDonough;
Amber L. Beitelshees;
Gary L. Schwartz;
John G. Gums;
Sandosh Padmanabhan;
Timo P. Hiltunen;
Lorena Citterio;
Kati M. Donner;
Thomas Hedner;
Chiara Lanzani;
Olle Melander;
Janna Saarela;
Samuli Ripatti;
Bjorn Wahlstrand;
Paolo Manunta;
Kimmo Kontula;
Anna F. Dominiczak;
Rhonda M. Cooper-DeHoff;
Julie A. Johnson
To identify novel genes influencing blood pressure response to thiazide diuretic therapy for hypertension, we conducted genome-wide association meta-analyses of ≈1.1 million single-nucleotide polymorphisms in a combined sample of 424 European Americans with primary hypertension treated with hydrochlorothiazide from the Pharmacogenomic Evaluation of Antihypertensive Responses study (n=228) and the Genetic Epidemiology of Responses to Antihypertensive study (n=196). Polymorphisms associated with blood pressure response at P<10-5 were tested for replication of the associations in independent samples of hydrochlorothiazide-treated European hypertensives. The rs16960228 polymorphism in protein kinase C, α replicated for same-direction association with diastolic blood pressure response in the Nordic Diltiazem study (n=420) and the Genetics of Drug Responsiveness in Essential Hypertension study (n=206), and the combined 4-study meta-analysis P value achieved genome-wide significance (P=3.3×10-8). Systolic or diastolic blood pressure responses were consistently greater in carriers of the rs16960228 A allele than in GG homozygotes (>4/4 mm Hg) across study samples. The rs2273359 polymorphism in the GNAS-EDN3 region also replicated for same-direction association with systolic blood pressure response in the Nordic Diltiazem study, and the combined 3-study meta-analysis P value approached genome-wide significance (P=5.5×10-8). The findings document clinically important effects of genetic variation at novel loci on blood pressure response to a thiazide diuretic, which may be a basis for individualization of antihypertensive drug therapy and identification of new drug targets.
Inhibitors that target the retroviral enzyme reverse transcriptase (RT) have played an indispensable role in the treatment and prevention of HIV-1 infection. They can be grouped into two distinct therapeutic groups, namely the nucleoside and nucleotide RT inhibitors (NRTIs), and the non-nucleoside RT inhibitors (NNRTIs). NRTIs form the backbones of most first-and second-line antiretroviral therapy (ART) regimens formulated for the treatment of HIV-1 infection. They are also used to prevent mother-to-child transmission, and as pre-exposure prophylaxis in individuals at risk of HIV-1 infection. The NNRTIs nevirapine (NVP), efavirenz and rilpivirine also used to form part of first-line ART regimens, although this is no longer recommended, while etravirine can be used in salvage ART regimens. A single-dose of NVP administered to both mother and child has routinely been used in resource-limited settings to reduce the rate of HIV-1 transmission. Unfortunately, the development of HIV-1 resistance to RT inhibitors can compromise the efficacy of these antiviral drugs in both the treatment and prevention arenas. Here, we provide an up-to-date review on drug-resistance mutations in HIV-1 RT, and discuss their cross-resistance profiles, molecular mechanisms and clinical significance.