Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry.

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5 × 10-8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Use of a novel oleaginous microorganism as a potential source of lipids for weanling pigs.

Weanling pigs are at risk of succumbing to illness due to an immature immune system and insufficient supply of available energy at the time of weaning. This study was aimed at determining whether oleaginous bacteria could serve as a source of lipids to weanling pigs. Weanling pigs were provided a daily dose of 1×109 colony fomring unit (CFU) = kg-1 of the novel oleaginous Enterobacter cloacae strain JD6301 or JD8715 (which is a variant form of JD6301 capable of producing extracellular triglycerides) via oral gavage for 5 d. Serum was collected every 6 h and intestinal samples were collected at 6 d. Providing pigs with JD6301 or JD8715 significantly increased serum concentrations of triglycerides and non-esterified fatty acids (NEFA) within 72 h. Additionally, the JD6301 and JD8715 strains were able to survive within the gastrointestinal tract throughout the duration of the study. These results suggest that providing Enterobacter cloacae can increase the serum lipids in the pigs, thus potentially providing an additional source of energy to animals during times of stress. This could potentially help improve the metabolic response of animals during times of stress.

Declines in TBT contamination in Irish coastal waters 1987-2011, using the dogwhelk (Nucella lapillus) as a biological indicator.

Using the vas deferens sequence index (VDSI) and relative penis size index (RPSI) in dogwhelks (Nucella lapillus), imposex levels were assessed at 63 sites within 11 sea inlets during 2010/2011 and compared these with levels gathered since 1987. Sterile females (VDS>5.0) were found at 14 of the 63 sites and 47 sites (75%) met the EcoQO (VDSI<2.0). The absence of imposex in 'control' areas on the west coast is due to the lack of vessel paint applications or net dips with TBT being used as an active anti-fouling ingredient. A significant decline was observed following 2005 when comparing VDSI levels which is consistent with the decline of TBT usage. Current levels are consistent with an overall improvement towards achieving Good Environmental Status according to the requirements under the Marine Strategy Framework Directive.

Biomarkers: are realism and control mutually exclusive in integrated pollution assessment?

The conventional view of pollution monitoring is that any choice is a trade-off between realism and precision, as the control over confounding variables decreases with the increasing degree of organization of the test system. Dublin Bay is subject to considerable anthropogenic pressures and there have been many attempts to quantify the status of the system at organizational levels from DNA strand breaks (Comet) to the system itself (Ecological Network analysis, ENA). Using Dublin Bay as an example, the data show there was considerable variability at all levels of organization. At intracellular level, Lysosome Membrane Stability (LMS, assessed by Neutral Red Retention, NRR) varied almost 4-fold with season and individual condition, while the community level AZTI Marine biotic Index (AMBI) had a similar range within a single, supposedly homogeneous, site. Overall, there was no evidence that biomarkers of the lower levels of organisation reduced the variability of the measure, despite the extra control over influencing variables, nor was there any evidence that variability was additive at higher levels of organisation. This poses problems for management, especially given the fixed limits of Ecological Quality Standards (EQSs). Clearly while the integrated approach to pollution monitoring does offer the potential to link effects across the organizational range, it should also be possible to improve their capability by widening the database for reference values, particularly at the higher level of organization, and by process models, including the confounding variables found in the field, for those at lower level.

Assessment of biomarkers in Mytilus edulis to determine good environmental status for implementation of MSFD in Ireland.

Candidate OSPAR/ICES recommended biomarkers at the level of the individual in Mytilus edulis for determination of good environmental status for MSFD were evaluated against contaminant levels at sites around Ireland. The sites chosen ranged from moderate to low pollution levels, but the actual ranking of the sites varied according to the contaminant levels present. At the most contaminated site, Cork, 4 out of 16 contaminants exceeded the EAC, while at Shannon, no EACs were exceeded. The SOS assay suggested that Cork was the healthiest site with a LT50 of 17.6 days, while SOS for Shannon was 15.6 days. Likewise, condition factors varied among sites and did not always correspond to contaminant-based status. There may be uncertainty in assigning status around the not good:good boundary. This raises potential difficulties not only in the biomarker/contaminant load relationship but also in the reliability of the biomarkers themselves and hence barriers meeting compliance levels.

Gametogenic development and spawning of the freshwater clam, Galatea paradoxa (Born 1778) from the Volta River Estuary, Ghana.

The study focused on the reproductive cycle of Galatea paradoxa (Born 1778), a major species for artisanal fishery in the Volta River estuary, Ghana. Condition indices and histological observation of the gonads revealed that G. paradoxa has a single spawning event between July and October. Gametogenesis started in December progressing steadily to a peak in June-July when spawning began until November when individuals were spent. Condition and gonadal indices showed a clear relationship with the gametogenic stages.

Transferability and fine-mapping of glucose and insulin quantitative trait loci across populations: CARe, the Candidate Gene Association Resource.

AIMS/HYPOTHESIS: Hyperglycaemia disproportionately affects African-Americans (AfAs). We tested the transferability of 18 single-nucleotide polymorphisms (SNPs) associated with glycaemic traits identified in European ancestry (EuA) populations in 5,984 non-diabetic AfAs. METHODS: We meta-analysed SNP associations with fasting glucose (FG) or insulin (FI) in AfAs from five cohorts in the Candidate Gene Association Resource. We: (1) calculated allele frequency differences, variations in linkage disequilibrium (LD), fixation indices (F(st)s) and integrated haplotype scores (iHSs); (2) tested EuA SNPs in AfAs; and (3) interrogated within ± 250 kb around each EuA SNP in AfAs. RESULTS: Allele frequency differences ranged from 0.6% to 54%. F(st) exceeded 0.15 at 6/16 loci, indicating modest population differentiation. All iHSs were <2, suggesting no recent positive selection. For 18 SNPs, all directions of effect were the same and 95% CIs of association overlapped when comparing EuA with AfA. For 17 of 18 loci, at least one SNP was nominally associated with FG in AfAs. Four loci were significantly associated with FG (GCK, p = 5.8 × 10(-8); MTNR1B, p = 8.5 × 10(-9); and FADS1, p = 2.2 × 10(-4)) or FI (GCKR, p = 5.9 × 10(-4)). At GCK and MTNR1B the EuA and AfA SNPs represented the same signal, while at FADS1, and GCKR, the EuA and best AfA SNPs were weakly correlated (r(2) <0.2), suggesting allelic heterogeneity for association with FG at these loci. CONCLUSIONS/INTERPRETATION: Few glycaemic SNPs showed strict evidence of transferability from EuA to AfAs. Four loci were significantly associated in both AfAs and those with EuA after accounting for varying LD across ancestral groups, with new signals emerging to aid fine-mapping.

Common genetic variants differentially influence the transition from clinically defined states of fasting glucose metabolism.

AIMS/HYPOTHESIS: Common genetic variants have been associated with type 2 diabetes. We hypothesised that a subset of these variants may have different effects on the transition from normal fasting glucose (NFG) to impaired fasting glucose (IFG) than on that from IFG to diabetes. METHODS: We identified 16 type 2 diabetes risk variants from the Illumina Broad Candidate-gene Association Resource (CARe) array genotyped in 26,576 CARe participants. Participants were categorised at baseline as NFG, IFG or type 2 diabetic (n = 16,465, 8,017 or 2,291, respectively). Using Cox proportional hazards and likelihood ratio tests (LRTs), we compared rates of progression by genotype for 4,909 (NFG to IFG) and 1,518 (IFG to type 2 diabetes) individuals, respectively. We then performed multinomial regression analyses at baseline, comparing the risk of assignment to the NFG, IFG or diabetes groups by genotype. RESULTS: The rate of progression from NFG to IFG was significantly greater in participants carrying the risk allele at MTNR1B (p = 1 × 10(-4)), nominally greater at GCK and SLC30A8 (p < 0.05) and nominally smaller at IGF2BP2 (p = 0.01) than the rate of progression from IFG to diabetes by the LRT. Results of the baseline, multinomial regression model were consistent with these findings. CONCLUSIONS/INTERPRETATION: Common genetic risk variants at GCK, SLC30A8, IGF2BP2 and MTNR1B influence to different extents the development of IFG and the transition from IFG to type 2 diabetes. Our findings may have implications for understanding the genetic contribution of these variants to the development of IFG and type 2 diabetes.

Challenges encountered in measuring outcome for a rural psychiatric residential program.

Evaluation of outcome measures can provide policymakers with valuable information on the effectiveness of psychiatric rehabilitation. Two specific challenges in collecting outcome measures for psychiatric rehabilitation programs are heterogeneity of outcomes and difficulty with follow-up. These two challenges were illustrated in the process of evaluating Rose Hill Center, a rural residential psychiatric rehabilitation program. The original design was to conduct interviews with former residents and family members and verify healthcare utilization. The difficulty of locating people and their reluctance to participate conspired to lower the follow-up rates. The design was modified to improve the follow-up rate but decrease the details of specific outcomes. The results showed a high but biased follow-up rate, with more information obtained for people who graduated from the program. The residents with planned discharge showed excellent outcomes in terms of living situation, working situation, healthcare utilization, and low severity of current symptoms. High compliance with medication spoke to the program's philosophy of including the residents in the decision-making process. The dual challenges of heterogeneity of outcomes and difficulty in follow-up that limit efforts to document the value of psychiatric rehabilitation are discussed.

Liver X receptor (LXR) regulation of the LXRalpha gene in human macrophages.

The nuclear oxysterol receptors LXRalpha (NR1H3) and LXRbeta (NR1H2) coordinately regulate the expression of genes involved in the transport and catabolism of cholesterol. In macrophages, LXR stimulates the transcription of genes encoding transporters involved in cholesterol efflux, which may limit the transformation of these cells into foam cells in response to lipid loading. Here, we report that natural and synthetic LXR ligands induce the expression of the LXRalpha gene in primary human macrophages and differentiated THP-1 macrophages. This regulation was not observed in primary human adipocytes or hepatocytes, a human intestinal cell line, or in any mouse tissue or cell line examined. The human LXRalpha gene was isolated, and the transcription initiation site delineated. Analysis of the LXRalpha promoter revealed a functional LXR/RXR binding site approximately 2.9 kb upstream of the transcription initiation site. We conclude that LXRalpha regulates its own expression in human macrophages and that this response is likely to amplify the effects of oxysterols on reverse cholesterol transport. These findings underscore the importance of LXR as a potential therapeutic target for the treatment of atherosclerosis.

Retrospective review of selective serotonin reuptake inhibitors and falling in older nursing home residents.

We compared the rate of falling in older nursing home residents who had been prescribed selective serotonin reuptake inhibitors (SSRIs), other classes of antidepressants, and no antidepressants. Data were obtained from pharmacy records, medical records, fall logs, and incidence reports for one nursing home (1995 data). Older adults on SSRIs were more likely to fall than older adults not on antidepressants (p = .003) and were more likely to have an injurious fall (p = .03). The association with falling remained significant even when including potential confounders (p = .007). Older nursing home residents should be treated for depression. However, SSRIs may also carry an increased risk for falling.

Identification of a subtype selective human PPARalpha agonist through parallel-array synthesis.

Using solid-phase, parallel-array synthesis, a series of urea-substituted thioisobutyric acids was synthesized and assayed for activity on the human PPAR subtypes. GW7647 (3) was identified as a potent human PPARalpha agonist with approximately 200-fold selectivity over PPARgamma and PPARdelta, and potent lipid-lowering activity in animal models of dyslipidemia. GW7647 (3) will be a valuable chemical tool for studying the biology of PPARalpha in human cells and animal models of disease.

Progesterone inhibits glucocorticoid-induced murine thymocyte apoptosis.

Sex and sex hormones modulate immune development and responses. A primary target of their effects is the structure and cellularity of the thymus; therefore, we examined the effects of sex and sex steroids on thymocyte apoptosis. We demonstrate initially that male DBA mice have a significantly higher percentage of glucocorticoid-induced apoptotic thymocytes (46.1+/-3.8%) than their female counterparts (31.6+/-3.1%; P=0.012). We postulated that this gender difference was due to differential modulation of glucocorticoid-induced apoptosis by sex hormones such as estrogen, testosterone or progesterone. Both estrogen and testosterone increased in vitro thymocyte apoptosis. In contrast, progesterone not only inhibited spontaneous in vitro thymocyte apoptosis, but also prevented in vitro glucocorticoid-induced apoptosis. Progesterone administration also suppressed glucocorticoid-induced in vivo thymocyte apoptosis. These results suggest that anti-apoptotic effects of progesterone may influence T cell development and subsequent immune responses.

A regulatory cascade of the nuclear receptors FXR, SHP-1, and LRH-1 represses bile acid biosynthesis.

Bile acids repress the transcription of cytochrome P450 7A1 (CYP7A1), which catalyzes the rate-limiting step in bile acid biosynthesis. Although bile acids activate the farnesoid X receptor (FXR), the mechanism underlying bile acid-mediated repression of CYP7A1 remained unclear. We have used a potent, nonsteroidal FXR ligand to show that FXR induces expression of small heterodimer partner 1 (SHP-1), an atypical member of the nuclear receptor family that lacks a DNA-binding domain. SHP-1 represses expression of CYP7A1 by inhibiting the activity of liver receptor homolog 1 (LRH-1), an orphan nuclear receptor that is known to regulate CYP7A1 expression positively. This bile acid-activated regulatory cascade provides a molecular basis for the coordinate suppression of CYP7A1 and other genes involved in bile acid biosynthesis.

Effect of buprenorphine on CYP3A activity in rat and human liver microsomes.

Buprenorphine is a partial opioid agonist available in France as an alternative to methadone in the treatment of opiate-dependent individuals. Twenty deaths have been reported in patients who have ingested buprenorphine in combination with benzodiazepines. Since buprenorphine and many benzodiazepines are CYP3A substrates, the effect of buprenorphine on CYP3A activity was examined in order to assess the likelihood of a pharmacokinetic interaction. The formation of 6beta-hydroxytestosterone was measured in dexamethasone-induced rat liver microsomes and in human liver microsomes under control conditions and in the presence of buprenorphine. Buprenorphine was found to be a weak inhibitor of CYP3A with a 50% decrease in enzyme activity occurring at a concentration of 118 microM (IC50) in human liver microsomes. IC50 was 0.3 microM for ketoconazole in the same system. Since the IC50 for buprenorphine is roughly 2000 times higher than typical plasma concentrations, this drug is unlikely to cause clinically significant inhibition of CYP3A in patients. Excessive CNS depression due to the combination of buprenorphine and benzodiazepines is most likely due to additive or synergistic pharmacologic effect unrelated to a pharmacokinetic interaction between the drugs.

Quantitative alleles of CR1: coding sequence analysis and comparison of haplotypes in two ethnic groups.

The quantitative expression of complement receptor type 1 (CR1) on erythrocytes is regulated by two CR1 alleles that differ in having genomic HindIII fragments of either 7.4 or 6.9 kb and that determine high (H allele) or low (L allele) CR1 expression, respectively, across a 10-fold range. To investigate whether the product of the L allele may contain amino acid substitutions that make it more susceptible to proteolysis, cDNA sequence spanning the CR1 coding region was analyzed in two donors who were homozygous for the H and L alleles and differed by 7-fold in their mean numbers of CR1 per erythrocyte. Sequence differences were detected at 10 nucleotide positions, including 6 that would cause amino acid substitutions. The HindIII RFLP and 3 of the latter 6 sites were analyzed in genomic DNA of 85 Caucasians and 75 African Americans; sites encoding the other amino acid substitutions were analyzed less extensively. Two major haplotypes defined prototypic H and L alleles in both ethnic groups, suggesting that these alleles existed before the African and European populations diverged. Decreased erythrocyte CR1 expression is associated with impaired clearance of immune complexes from blood. Persistence of the L allele in all populations that have been analyzed may suggest a compensatory survival advantage, perhaps related to malaria or another infectious disease.