A goal of the Tox21 program is to transit toxicity testing from traditional in vivo models to in vitro assays that assess how chemicals affect cellular responses and toxicity pathways. A critical contribution of the NIH Chemical Genomics center (NCGC) to the Tox21 program is the implementation of a quantitative high throughput screening (qHTS) approach, using cell- and biochemical-based assays to generate toxicological profiles for thousands of environmental compounds. Here, we evaluated the effect of chemical compounds on mitochondrial membrane potential in HepG2 cells by screening a library of 1,408 compounds provided by the National Toxicology Program (NTP) in a qHTS platform. Compounds were screened over 14 concentrations, and results showed that 91 and 88 compounds disrupted mitochondrial membrane potential after treatment for 1 or 5 h, respectively. Seventy-six compounds active at both time points were clustered by structural similarity, producing 11 clusters and 23 singletons. Thirty-eight compounds covering most of the active chemical space were more extensively evaluated. Thirty-six of the 38 compounds were confirmed to disrupt mitochondrial membrane potential using a fluorescence plate reader, and 35 were confirmed using a high content imaging approach. Among the 38 compounds, 4 and 6 induced LDH release, a measure of cytotoxicity, at 1 or 5 h, respectively. Compounds were further assessed for mechanism of action (MOA) by measuring changes in oxygen consumption rate, which enabled the identification of 20 compounds as uncouplers. This comprehensive approach allows for the evaluation of thousands of environmental chemicals for mitochondrial toxicity and identification of possible MOAs.

Uterine fibroids (UFs) affect 77 % of women by menopause and account for $9.4 billion in yearly healthcare costs. We recently replicated findings from the first UF genome-wide association study (GWAS), conducted in the Japanese. Here we tested these GWAS-discovered SNPs for association with UF characteristics to further assess whether risk varies by sub-phenotypes of UFs. Women were enrolled in Right from the Start (RFTS) and the BioVU DNA repository (BioVU). UF status was determined by pelvic imaging. We tested the top GWAS-associated SNPs for association with UF characteristics (RFTS: type, number, volume; BioVU: type) using covariate adjusted logistic and linear regression. We also combined association results of UF type using meta-analysis. 456 European American (EA) cases and 1,549 controls were examined. Trinucleotide repeat containing 6B (TNRC6B) rs12484776 associated with volume in RFTS (β = 0.40, 95 % CI 0.05-0.75, p = 0.024). RFTS analyses evaluating stratified quartiles of volume showed the strongest OR at rs12484776 for the largest volume (16.6-179.1 cc, odds ratio (OR) = 2.19, 95 % confidence interval (CI) 1.07-4.46, p = 0.031). Meta-analysis showed a strong association at blocked early in transport 1 homolog (BET1L) rs2280543 for intramural UFs (meta-OR = 0.51, standard error (SE) = 0.14, Q = 0.590, I = 0, p = 2.48 × 10(-6)), which is stronger than the overall association with UF risk. This study is the first to evaluate these SNPs for association with UF characteristics and suggests these genes associate with increasing UF volume and protection from intramural UF in EAs.

The idea that the conceptual system draws on sensory and motor systems has received considerable experimental support in recent years. Whether the tight coupling between sensory-motor and conceptual systems is modulated by factors such as context or task demands is a matter of controversy. Here, we tested the context sensitivity of this coupling by using action verbs in three different types of sentences in an fMRI study: literal action, apt but non-idiomatic action metaphors, and action idioms. Abstract sentences served as a baseline. The result showed involvement of sensory-motor areas for literal and metaphoric action sentences, but not for idiomatic ones. A trend of increasing sensory-motor activation from abstract to idiomatic to metaphoric to literal sentences was seen. These results support a gradual abstraction process whereby the reliance on sensory-motor systems is reduced as the abstractness of meaning as well as conventionalization is increased, highlighting the context sensitive nature of semantic processing.

Hookworms are parasitic nematodes that have a devastating impact on global health, particularly in developing countries. We report a biochemical and structural analysis of a peroxiredoxin from the hookworm Ancylostoma ceylanicum, AcePrx-1. Peroxiredoxins provide antioxidant protection and act as signaling molecules and chaperones. AcePrx-1 is expressed in adult hookworms and can be inactivated by 2,3-bis(bromomethyl)quinoxaline-1,4-dioxide (conoidin A). Conoidin A inactivates AcePrx-1 by alkylating or crosslinking the catalytic cysteines, while maintaining the enzyme in the "locally unfolded" conformation. Irreversible oxidation of the resolving cysteine may contribute additional inhibitory activity. A crystal structure of oxidized AcePrx-1 reveals a disulfide-linked decamer. A helix macrodipole near the active site increases the reactivity of the catalytic cysteines to conoidin A. This work demonstrates the promise of conoidin compounds as probes to evaluate peroxiredoxins as drug targets in human parasites.

Severe hypoglycemia in patients with diabetes is associated with increased risk of adverse cardiovascular events and death. Recent large randomized clinical trials in individuals with type 2 diabetes have shown that intensive glycemic control may result in increased mortality, and hypoglycemia has been investigated as a possible cause. Acute hypoglycemia is a proarrhythmic, proinflammatory, and prothrombotic state, and several mechanisms have been proposed to explain how hypoglycemia might increase cardiovascular morbidity and mortality. However, data from large clinical trials do not provide strong evidence to establish hypoglycemia as a cause of increased mortality. Severe hypoglycemia is also a marker of frailty and a predictor of adverse outcomes in patients with diabetes. Individualized therapy should be the goal in patients with diabetes to avoid severe hypoglycemia and any related adverse outcomes.

Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

OBJECTIVES: Patients with rheumatoid arthritis (RA) are at increased risk for cardiovascular disease (CVD), although strategies to detect subclinical CVD are poorly characterised. The purpose of this study was to assess myocardial function by speckle-tracking echocardiography strain imaging in patients with RA without known CVD. METHODS: Eighty-seven patients with RA selected from a population-based sample underwent echocardiography. Left ventricular (LV) and right ventricular (RV) longitudinal peak systolic strain were measured. A subset of 59 patients with RA was compared with 59 age-, gender- and race-matched subjects with normal echocardiography and no CVD or risk factors. RESULTS: The mean ± SD age of the patients with RA and the normal patients was 55.7±12.1 and 54.5±12.2 years (p=0.42), respectively, with 45 (76%) women in each group. Global LV strain (-15.7±3.2% vs -18.1±2.4%, p<0.001) and RV strain (-17.9±4.7% vs -20.7±2.4%, p<0.001) was reduced in patients with RA compared with normal patients. Among all 87 patients with RA the mean disease duration and C-reactive protein at echocardiography were 10.0±6.1 years and 3.5±3.7 mg/L, and 74% were seropositive. Adjusted univariate regression analysis demonstrated a significant correlation between global LV strain and RA Health Assessment Questionnaire disability index (p=0.032), and borderline associations with prior use of oral corticosteroids (p=0.062) and methotrexate (p=0.054) after adjustment for age, gender, blood pressure, body mass index, heart rate and LV mass index. CONCLUSIONS: Global longitudinal LV and RV strain is reduced in patients with RA compared with healthy patients. Strain abnormalities correlate with RA disease severity. Strain imaging by echocardiography may detect early myocardial dysfunction in RA.

We assessed the occurrence of 4 safety concerns among labor and delivery teams: dangerous shortcuts, missing competencies, disrespect, and performance problems. A total of 3282 participants completed surveys, and 92% of physicians (906 of 985), 93% of midwives (385 of 414), and 98% of nurses (1846 of 1884) observed at least 1 concern within the preceding year. A majority of respondents said these concerns undermined patient safety, harmed patients, or led them to seriously consider transferring or leaving their positions. Only 9% of physicians, 13% of midwives, and 13% of nurses shared their full concerns with the person involved. Organizational silence is evident within labor-and-delivery teams. Improvement will require multiple strategies, used at the personal, social, and structural levels.

OBJECTIVE: Our objective was to determine whether a questionnaire can identify individuals with vitamin D insufficiency (VDI). DESIGN: Women completed the Vitamin D & Sun (VIDSUN) questionnaire and we measured their serum 25-hydrocyvitamin D (25(OH)D) levels. We assessed the sensitivity and specificity of the questionnaire to identify VDI (25(OH)D level <50 nmol/l). SETTING: Clinical Research Unit, University of Wisconsin-Madison. SUBJECTS: Postmenopausal women. RESULTS: We recruited 609 postmenopausal women with a mean age of 61 (sd 6 years), of whom 113 (19%) had VDI. Women with VDI were more likely to be black (17% v. 2%, P < 0.001), heavier (BMI 33.0 (sd 7) kg/m2 v. 29.0 (sd 7) kg/m2, P < 0.001) and less likely to tan in the past year (49% v. 72%, P < 0.001), use sunscreen (57% v. 72%, P < 0.001) or report sun exposure in the last 3 months. They consumed less vitamin D from supplements (2.15 (sd 5.24) μg/d (86 (sd 210) IU/d) v. 4.55 (sd 8.48) μg/d (188 (sd 344) IU/d), P = 0.003). In logistic regression models, black race, BMI, suntan within the past year, sun exposure in the past 3 months, sunscreen use and supplemental vitamin D intake were the most useful questions to identify VDI. From these six items, a composite score of ≤ 2.25 demonstrated ≥89% sensitivity but ≤35% specificity for VDI. CONCLUSIONS: The VIDSUN questionnaire provides an initial tool to identify postmenopausal women at high or low risk of VDI. Existing studies suggest that inclusion of physical activity and TAG levels might improve the performance of the VIDSUN questionnaire.

OBJECTIVES: Although age-related brain changes are becoming better understood, midlife patterns of change are still in need of characterization, and longitudinal studies are lacking. The aim of this study was to determine if baseline fractional anisotropy (FA), obtained from diffusion tensor imaging (DTI) predicts volume change over a 4-year interval. EXPERIMENTAL DESIGN: Forty-four cognitively healthy middle-age adults underwent baseline DTI and longitudinal T1-weighted magnetic resonance imaging. Tensor-based morphometry methods were used to evaluate volume change over time. FA values were extracted from regions of interest that included the cingulum, entorhinal white matter, and the genu and splenium of the corpus callosum. Baseline FA was used as a predictor variable, whereas gray and white matter atrophy rates as indexed by Tensor-based morphometry were the dependent variables. PRINCIPAL OBSERVATIONS: Over a 4-year period, participants showed significant contraction of white matter, especially in frontal, temporal, and cerebellar regions (P < 0.05, corrected for multiple comparisons). Baseline FA in entorhinal white matter, genu, and splenium was associated with longitudinal rates of atrophy in regions that included the superior longitudinal fasciculus, anterior corona radiata, temporal stem, and white matter of the inferior temporal gyrus (P < 0.001, uncorrected for multiple comparisons). CONCLUSIONS: Brain change with aging is characterized by extensive shrinkage of white matter. Baseline white matter microstructure as indexed by DTI was associated with some of the observed regional volume loss. The findings suggest that both white matter volume loss and microstructural alterations should be considered more prominently in models of aging and neurodegenerative diseases.