The conus coronary artery has been reported to arise independently from the aorta in approximately 45 per cent of hearts. In this study, 305 necropsy specimens were examined to determine the origin of the conus coronary artery and variations in patterns of origin with respect to age. Three patterns were recognised: 1, in which the conus artery arose from the aorta independently of the right coronary artery; 2, in which the conus artery and the right coronary arose from a common ostium; and 3, in which only the right coronary artery took origin from the right aortic sinus. The relative incidence of the three patterns varied with age. Pattern 1 was recognised in 14 to 24 per cent of specimens from patients under the age of 2 years, whereas in older patients, it occurred in 41 to 63 per cent. These data suggest that aortic origin of the conus arterial ostium may appear in some individuals between 2 and 4 years of age, and they support the concept that some coronary arterial patterns are not fully established at the time of birth.
Genetic epidemiology, the study of genetic contributions to risk for disease, is an innovative area in medicine. While research in this arena has advanced in other disciplines, few genetic epidemiologic studies have been conducted in obstetrics and gynecology. It is crucial that we study the genetic susceptibility for issues in women’s health, as this information will shape the new frontier of “personalized medicine.” To date, preterm birth may be one of the best examples of genetic susceptibility in obstetrics and gynecology, but many areas are being evaluated including endometriosis, fibroids, polycystic ovarian syndrome and pelvic floor disorders. An essential component to genetic epidemiologic studies is to characterize, or “phenotype,” the disorder in order to identify genetic effects. Given the growing importance of genomics and genetic epidemiology, we discuss the importance of accurate phenotyping of clinical disorders and highlight critical considerations and opportunities in phenotyping, using pelvic organ prolapse as a clinical example.
Falls from buildings, including houses, are an important cause of childhood injury in the United States; however, no study has previously examined the impact of this problem in Hawai‘i. The objective of this study is to categorize the demographics and injury circumstances of pediatric falls from buildings in Hawai‘i and compare to other US cities. Patients age 10 and under who were injured in nonfatal accidental falls from buildings in Hawai‘i between 2005 and 2011 were identified retrospectively from a statewide repository of hospital billing data. The Hawai‘i death certificate database was searched separately for deaths in children age 10 and under due to falls from buildings, with data available from 1991 through 2011. Data was reviewed for demographics, circumstances surrounding the injury, and level of hospital treatment. During the 7-year period for nonfatal injuries, 416 fall-related injuries were identified in children age 10 and younger. Of these, 86 required hospitalization. The rate of nonfatal injury in Hawai‘i County was twice that of Honolulu and Maui Counties, and three times that of Kaua‘i County. There were 9 fatal falls over a 21-year period. The population based incidence for nonfatal injuries was three-fold higher than that reported in the city of Dallas. The rate of hospitalizations following building falls was more than twice as high as the national average, and that of New York City, but similar to that of California. Strategies for education and environmental modification are reviewed, which may be helpful in reducing the incidence of pediatric falls from buildings in Hawai‘i.
Increased potassium intake has been shown to lower blood pressure (BP) even in the presence of high sodium consumption however the role of dietary potassium on vascular function has received less attention. The aim of this study was to evaluate the relationship between habitual intake of sodium (Na) and potassium (K) and measures of arterial stiffness and wave reflection.
Thirty-six young healthy adults (21 M, 15 F; 24 ± 0.6 yrs; systolic BP 117 ± 2; diastolic BP 63 ± 1 mmHg) recorded their dietary intake for 3 days and collected their urine for 24 hours on the 3rd day. Carotid-femoral pulse wave velocity (PWV) and the synthesis of a central aortic pressure waveform (by radial artery applanation tonometry and generalized transfer function) were performed. Aortic augmentation index (AI), an index of wave reflection, was calculated from the aortic pressure waveform.
Subjects consumed an average of 2244 kcals, 3763 mg Na, and 2876 mg of K. Average urinary K excretion was 67 ± 5.3 mmol/24 hr, Na excretion was 157 ± 11 mmol/24 hr and the average Na/K excretion ratio was 2.7 ± 0.2. An inverse relationship between AI and K excretion was found (r = -0.323; p < 0.05). A positive relationship between AI and the Na/K excretion ratio was seen (r = 0.318; p < 0.05) while no relationship was noted with Na excretion alone (r = 0.071; p > 0.05). Reflection magnitude, the ratio of reflected and forward waves, was significantly associated with the Na/K excretion ratio (r = 0.365; p <0.05) but not Na or K alone. PWV did not correlate with Na or the Na/K excretion ratio (p > 0.05) but showed an inverse relationship with K excretion (r = -0.308; p < 0.05).
These data suggest that lower potassium intakes are associated with greater wave reflection and stiffer arteries in young healthy adults.
Potassium; Sodium; Wave reflection; Arterial stiffness
Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture.
Scant genomic information from non-avian reptile sex chromosomes is available, and for only a few lizards, several snakes and one turtle species, and it represents only a small fraction of the total sex chromosome sequences in these species.
We report a 352 kb of contiguous sequence from the sex chromosome of a squamate reptile, Pogona vitticeps, with a ZZ/ZW sex microchromosome system. This contig contains five protein coding genes (oprd1, rcc1, znf91, znf131, znf180), and major families of repetitive sequences with a high number of copies of LTR and non-LTR retrotransposons, including the CR1 and Bov-B LINEs. The two genes, oprd1 and rcc1 are part of a homologous syntenic block, which is conserved among amniotes. While oprd1 and rcc1 have no known function in sex determination or differentiation in amniotes, this homologous syntenic block in mammals and chicken also contains R-spondin 1 (rspo1), the ovarian differentiating gene in mammals. In order to explore the probability that rspo1 is sex determining in dragon lizards, genomic BAC and cDNA clones were mapped using fluorescence in situ hybridisation. Their location on an autosomal microchromosome pair, not on the ZW sex microchromosomes, eliminates rspo1 as a candidate sex determining gene in P. vitticeps.
Our study has characterized the largest contiguous stretch of physically mapped sex chromosome sequence (352 kb) from a ZZ/ZW lizard species. Although this region represents only a small fraction of the sex chromosomes of P. vitticeps, it has revealed several features typically associated with sex chromosomes including the accumulation of large blocks of repetitive sequences.
ZW sex chromosomes; Genotypic sex determination (GSD); Temperature dependent sex determination (TSD); RSPO1; Squamata; Reptilia
Genome-wide association studies (GWAS) have identified 36 loci associated with body mass index (BMI), predominantly in populations of European ancestry. We conducted a meta-analysis to examine the association of >3.2 million SNPs with BMI in 39,144 men and women of African ancestry, and followed up the most significant associations in an additional 32,268 individuals of African ancestry. We identified one novel locus at 5q33 (GALNT10, rs7708584, p=3.4×10−11) and another at 7p15 when combined with data from the Giant consortium (MIR148A/NFE2L3, rs10261878, p=1.2×10−10). We also found suggestive evidence of an association at a third locus at 6q16 in the African ancestry sample (KLHL32, rs974417, p=6.9×10−8). Thirty-two of the 36 previously established BMI variants displayed directionally consistent effect estimates in our GWAS (binomial p=9.7×10−7), of which five reached genome-wide significance. These findings provide strong support for shared BMI loci across populations as well as for the utility of studying ancestrally diverse populations.
Histone deacetylase 1 and 2 (HDAC1/2) regulate chromatin structure as the catalytic core of the Sin3A, NuRD and CoREST co-repressor complexes. To better understand the key pathways regulated by HDAC1/2 in the adaptive immune system and inform their exploitation as drug targets, we have generated mice with a T cell specific deletion. Loss of either HDAC1 or HDAC2 alone has little effect, while dual inactivation results in a 5-fold reduction in thymocyte cellularity, accompanied by developmental arrest at the double-negative to double-positive transition. Transcriptome analysis revealed 892 mis-regulated genes in Hdac1/2 knock-out thymocytes, including down-regulation of LAT, Themis and Itk, key components of the T cell receptor (TCR) signalling pathway. Down-regulation of these genes suggests a model in which HDAC1/2 deficiency results in defective propagation of TCR signalling, thus blocking development. Furthermore, mice with a single Hdac2 allele, develop a lethal pathology by 3-months of age, a result of neoplastic transformation of immature T cells in the thymus. Tumor cells become aneuploid, express increased levels of c-Myc and show elevated levels of the DNA damage marker, γH2AX. These data demonstrate a crucial role for HDAC1/2 in T cell development and the maintenance of genomic stability.
Deacetylase; chromatin; T cell; development and cancer
TERT-locus single nucleotide polymorphisms (SNPs) and leucocyte telomere measures are reportedly associated with risks of multiple cancers. Using the iCOGs chip, we analysed ~480 TERT-locus SNPs in breast (n=103,991), ovarian (n=39,774) and BRCA1 mutation carrier (11,705) cancer cases and controls. 53,724 participants have leucocyte telomere measures. Most associations cluster into three independent peaks. Peak 1 SNP rs2736108 minor allele associates with longer telomeres (P=5.8×10−7), reduced estrogen receptor negative (ER-negative) (P=1.0×10−8) and BRCA1 mutation carrier (P=1.1×10−5) breast cancer risks, and altered promoter-assay signal. Peak 2 SNP rs7705526 minor allele associates with longer telomeres (P=2.3×10−14), increased low malignant potential ovarian cancer risk (P=1.3×10−15) and increased promoter activity. Peak 3 SNPs rs10069690 and rs2242652 minor alleles increase ER-negative (P=1.2×10−12) and BRCA1 mutation carrier (P=1.6×10−14) breast and invasive ovarian (P=1.3×10−11) cancer risks, but not via altered telomere length. The cancer-risk alleles of rs2242652 and rs10069690 respectively increase silencing and generate a truncated TERT splice-variant.
Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.
More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer ‘stem’ cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.
The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.
With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.
Exercise is commonly used as an intervention to increase caloric output and positively affect body composition. A major challenge is the low compliance often seen when the prescribed exercise is associated with high levels of exertion. Whole-body vibration (WBV) may allow increased caloric output with reduced effort; however, there is limited information concerning the effect of WBV on oxygen consumption (VO2). Therefore, this study assessed the synergistic effects of resistance training and WBV on VO2. We examined VO2 at different loads (0%, 20%, and 40% body weight (BW)) and vibration intensities (No vibration (NV), 35HZ, 2-3mm (35L), 50Hz, 57mm (50H)) in ten men (26.5 ± 5.1 years). Data were collected during different stages (rest, six 30s sets of squatting, and recovery). Repeated measures ANOVA showed a stage x load x vibration interaction. Post hoc analysis revealed no differences during rest; however, a significant vibration x load interaction occurred during exercise. Both 35L and 50H produced greater VO2 than NV at a moderate load of 20%BW. Although 40%BW produced greater VO2 than 20%BW or 0%BW using NV, no significant difference in VO2 was seen among vibratory conditions at 40%BW. Moreover, no significant differences were seen between 50H and 35L at 20%BW and NV at 40%BW. During recovery there was a main effect for load. Post hoc analyses revealed that VO2 at 40%BW was significantly higher than 20%BW or 0%BW, and 20%BW produced higher VO2 than no load. Minute-by-minute analysis revealed a significant impact on VO2 due to load but not to vibratory condition. We conclude that the synergistic effect of WBV and active squatting with a moderate load is as effective at increasing VO2 as doubling the external load during squatting without WBV.
Key PointsSynchronous whole body vibration in conjunction with moderate external loading (app 20% BW) can increase oxygen consumption to the same extent as heavier loading (40% BW) during performance of the parallel squat.While the application of synchronous whole body vibration had no effect on recovery oxygen, under bot vibratory and non-vibratory conditions, the heavier the external load the greater the recovery oxygen consumption levels.Regardless of vibratory condition, during the squatting exercise bout 40% BW produced higher heart rates than 20%BW or 0% BW, and 20% BW produced higher heart rates than 0% BW.There were strong trends toward higher heart rates in both vibratory conditions (50 Hz, 5-6mm; 35 Hz, 2-3 mm) than in the non-vibratory condition regardless of external loading.
Energy expenditure; weight loss; exercise prescription
Genome-wide association studies of obesity measures have identified associations with single nucleotide polymorphisms (SNPs). However, no large-scale evaluation of gene-environment interactions has been performed. We conducted a search of gene-environment (G×E) interactions in post-menopausal African-American and Hispanic women from the Women’s Health Initiative SNP Health Association Resource GWAS study. Single SNP linear regression on body mass index (BMI) and waist-to-hip circumference ratio (WHR) adjusted for multidimensional-scaling-derived axes of ancestry and age was run in race-stratified data with 871,512 SNPs available from African-Americans (N=8,203) and 786,776 SNPs from Hispanics (N=3,484). Tests of G×E interaction at all SNPs for recreational physical activity (met-hrs/wk), dietary energy intake (kcal/day), alcohol intake (categorical), cigarette smoking years, and cigarette smoking (ever vs. never) were run in African-Americans and Hispanics adjusted for ancestry and age at interview, followed by meta-analysis of G×E interaction terms. The strongest evidence for concordant G×E interactions in African-Americans and Hispanics was for smoking and marker rs10133840 (Q statistic P=0.70, beta=−0.01, P=3.81×10−7) with BMI as the outcome. The strongest evidence for G×E interaction within a cohort was in African-Americans with WHR as outcome for dietary energy intake and rs9557704 (SNP×kcal =−0.04, P=2.17×10−7). No results exceeded the Bonferroni–corrected statistical significance threshold.
BMI; WHR; genetic epidemiology; disparity; obesity; GWAS
Fetal stress is relevant to newborn outcomes. Corticosterone is rarely quantified in human clinical endocrinology and is found at much lower concentrations than cortisol. However, fetal corticosterone is a candidate hormone as a fetal stress signal.
Test the hypothesis that preferential fetal corticosterone synthesis occurs in response to fetal intra-partum stress.
Cross-sectional comparison of paired serum corticosteroid concentrations in umbilical artery and vein from 300 women providing consent at admission to a General Hospital Labor and Delivery unit. Pre-term and multiple births were excluded, leaving 265 healthy deliveries.
Main Outcome Measures
Corticosterone and cortisol concentrations determined by LC-MS/MS for umbilical cord venous (V) and arterial (A) samples and used to calculate fetal synthesis (A−V) and proportional fetal synthesis ([A−V]/V). Chart-derived criteria stratified samples by type of delivery, maternal regional analgesia, augmentation of contractions, and clinical rationale for emergent Caesarian delivery.
Cortisol concentrations were higher than corticosterone concentrations; however, the fetus preferentially secretes corticosterone (148% vs 49% proportional increase for cortisol) and differentially secretes corticosterone as fetal stress increases. Fetal corticosterone synthesis is elevated after passage through the birth canal relative to Caesarian deliveries. For vaginal deliveries, augmentation of contractions does not affect corticosteroid concentrations whereas maternal regional analgesia decreases venous (maternal) concentrations and increases fetal synthesis. Fetal corticosterone synthesis is also elevated after C-section indicated by cephalopelvic disproportion after labor, whereas cortisol is not.
The full-term fetus preferentially secretes corticosterone in response to fetal stress during delivery. Fetal corticosterone could serve as a biomarker of fetal stress.
The encapsulation of proteins in biomimetic silica has recently been shown to successfully maintain enzymes in their active state. Organophosphate (OP) compounds are employed as pesticides as well as potent chemical warfare nerve agents. Because these toxicants are life threatening, we sought to generate biomimetic silicas capable of responding to OPs. Here, we present the silica encapsulation of human drug metabolism enzyme carboxylesterase 1 (hCE1) in the presence of a range of catalysts. hCE1 was successfully encapsulated into silica particles when lysozyme or the peptide R5 were used as catalysts; in contrast, polyethyleneimine (PEI), a catalyst employed to encapuslate other enzymes, did not facilitate hCE1 entrapment. hCE1 silica particles in a column chromatography format respond to the presence of the organophosphate (OP) pesticides paraoxon and dimethyl-p-nitrophenyl phosphate in solution. These results may lead to novel approaches to detect OP pesticides or other weaponized agents that bind hCE1.
drug metabolism; biomimetic silica; enzyme immobilization; organophosphate pesticide
The World Health Organization estimates that the number of obese and overweight adults has increased to 1.6 billion, with concomitant increases in comorbidity. While genetic factors for obesity have been extensively studied in Caucasians, fewer studies have investigated genetic determinants of body mass index (BMI; weight (kg)/height (m)2) in African Americans. A total of 38 genes and 1,086 single nucleotide polymorphisms (SNPs) in African Americans (n = 1,173) and 897 SNPs in Caucasians (n = 1,165) were examined in the Southern Community Cohort Study (2002–2009) for associations with BMI and gene × environment interactions. A statistically significant association with BMI survived correction for multiple testing at rs4140535 (β = −0.04, 95% confidence interval: −0.06, −0.02; P = 5.76 × 10−5) in African Americans but not in Caucasians. Gene-environment interactions were observed with cigarette smoking and a SNP in ADIPOR1 in African Americans, as well as between a different SNP in ADIPOR1 and physical activity in Caucasians. A SNP in PPARGC1A interacted with alcohol consumption in African Americans, and a different SNP in PPARGC1A was nominally associated in Caucasians. A SNP in CYP19A1 interacted with dietary energy intake in African Americans, and another SNP in CYP191A had an independent association with BMI in Caucasians.
African continental ancestry group; body mass index; European continental ancestry group; genetics; molecular epidemiology; obesity
Osteoclasts play a key role in the development of cancer-associated osteolytic lesions. The number and activity of osteoclasts are often enhanced by tumors. However, the origin of osteoclasts is unknown. Myeloid-derived suppressor cells (MDSCs) are one of the pre-metastatic niche components that are induced to expand by tumor cells. Here we show that the MDSCs can differentiate into mature and functional osteoclasts in vitro and in vivo. Inoculation of 5TGM1-GFP myeloma cells into C57BL6/KaLwRij mice led to a significant expansion of MDSCs in blood, spleen, and bone marrow over time. When grown in osteoclastogenic media in vitro, MDSCs from tumor-challenged mice displayed 14 times greater potential to differentiate into mature and functional osteoclasts than those from non-tumor controls. Importantly, MDSCs from tumor-challenged LacZ transgenic mice differentiated into LacZ+osteoclasts in vivo. Furthermore, a significant increase in tumor burden and bone loss accompanied by increased number of osteoclasts was observed in mice co-inoculated with tumor-challenged MDSCs and 5TGM1 cells compared to the control animals received 5TGM1 cells alone. Finally, treatment of MDSCs from myeloma-challenged mice with Zoledronic acid (ZA), a potent inhibitor of bone resorption, inhibited the number of osteoclasts formed in MDSC cultures and the expansion of MDSCs and bone lesions in mice. Collectively, these data provide in vitro and in vivo evidence that tumor-induced MDSCs exacerbate cancer-associated bone destruction by directly serving as osteoclast precursors.
The monocyte chemotactic protein-1 (MCP-1) is a chemokine that plays an important role in the recruitment of monocytes to M. tuberculosis infection sites, and previous studies have reported that genetic variants in MCP1 are associated with differential susceptibility to pulmonary tuberculosis (PTB). We examined eight MCP1 single nucleotide polymorphisms (SNPs) in a multi-ethnic, case-control design that included: 321 cases and 346 controls from Guinea-Bissau, 258 cases and 271 controls from The Gambia, 295 cases and 179 controls from the U.S. (African-Americans), and an additional set of 237 cases and 144 controls of European ancestry from the U.S. and Argentina. Two locus interactions were also examined for polymorphisms in MCP1 and interleukin 12B (IL12B), another gene implicated in PTB risk. Examination of previously associated MCP1 SNPs rs1024611 (−2581A/G), rs2857656 (−362G/C) and rs4586 (+900C/T) did not show evidence for association. One interaction between rs2857656 and IL12B SNP rs2288831 was observed among Africans but the effect was in the opposite direction in Guineans (OR = 1.90, p = 0.001) and Gambians (OR = 0.64, p = 0.024). Our data indicate that the effect of genetic variation within MCP1 is not clear cut and additional studies will be needed to elucidate its role in TB susceptibility.
Inadequate health literacy has been associated with poor management of long-term health conditions and has been identified as a key social determinant of health outcomes. However, little is understood about how health literacy might develop over time or the processes by which people may become more health literate. Our objectives were to describe how patients with a long-term condition practice health literacy in the management of their health and communication with health professionals, how they become more health literate over time and their experience of using health services. We also sought to identify and describe the motivations, facilitators and barriers in the practice of health literacy in healthcare consultations.
We designed a longitudinal qualitative study using serial interviews with 18 participants to explore their experiences of learning to manage their condition and their experiences of health literacy when participating in healthcare processes. Participants were recruited from patient education programmes and were interviewed three times over a period of 9 months. A framework approach was used to analyse data.
A model is presented that illustrates the development of health literacy along a trajectory that includes the development of knowledge, health literacy skills and practices, health literacy actions, abilities in seeking options and informed and shared decision making opportunities. Motivations and barriers to developing and practising health literacy skills partly reflected participants' characteristics but were also influenced by health professionals. Some participants developed their health literacy to a point where they became more involved in healthcare processes (including informed and shared decision-making).
Patients with a long-term condition can develop health literacy skills over time and put their skills into practice in becoming more active in healthcare consultations. Our findings have implications for developing health literacy interventions aimed at patient involvement in healthcare processes and improved self-management of long-term conditions.
Organophosphorus (OP) nerve agents are potent suicide inhibitors of the essential neurotransmitter-regulating enzyme acetylcholinesterase. Due to their acute toxicity, there is significant interest in developing effective countermeasures to OP poisoning. Here we impart nerve agent hydrolysis activity into the human drug metabolism enzyme carboxylesterase 1. Using crystal structures of the target enzyme in complex with nerve agent as a guide, a pair of histidine and glutamic acid residues were designed proximal to the enzyme's native catalytic triad. The resultant variant protein demonstrated significantly increased rates of reactivation following exposure to sarin, soman, and cyclosarin. Importantly, the addition of these residues did not alter the high affinity binding of nerve agents to this protein. Thus, using two amino acid substitutions, a novel enzyme was created that efficiently converted a group of hemisubstrates, compounds that can start but not complete a reaction cycle, into bona fide substrates. Such approaches may lead to novel countermeasures for nerve agent poisoning.
We examined whether polymorphisms in interleukin-12B (IL12B) associate with susceptibility to pulmonary tuberculosis (PTB) in two West African populations (from The Gambia and Guinea-Bissau) and in two independent populations from North and South America. Nine polymorphisms (seven SNPs, one insertion/deletion, one microsatellite) were analyzed in 321 PTB cases and 346 controls from Guinea-Bissau and 280 PTB cases and 286 controls from The Gambia. For replication we studied 281 case and 179 control African-American samples and 221 cases and 144 controls of European ancestry from the US and Argentina. First-stage single locus analyses revealed signals of association at IL12B 3′ UTR SNP rs3212227 (unadjusted allelic p = 0.04; additive genotypic p = 0.05, OR = 0.78, 95% CI [0.61–0.99]) in Guinea-Bissau and rs11574790 (unadjusted allelic p = 0.05; additive genotypic p = 0.05, OR = 0.76, 95% CI [0.58–1.00]) in The Gambia. Association of rs3212227 was then replicated in African-Americans (rs3212227 allelic p = 0.002; additive genotypic p = 0.05, OR = 0.78, 95% CI [0.61–1.00]); most importantly, in the African-American cohort, multiple significant signals of association (seven of the nine polymorphisms tested) were detected throughout the gene. These data suggest that genetic variation in IL12B, a highly relevant candidate gene, is a risk factor for PTB in populations of African ancestry, although further studies will be required to confirm this association and identify the precise mechanism underlying it.