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1.  The role of covariate heterogeneity in meta-analysis of gene-environment interactions with quantitative traits 
Genetic epidemiology  2014;38(5):416-429.
With challenges in data harmonization and covariate heterogeneity across various data sources, meta-analysis of gene-environment interaction studies can often involve subtle statistical issues. In this paper, we study the effect of environmental covariate heterogeneity (within and between cohorts) on two approaches for fixed-effect meta-analysis: the standard inverse-variance weighted meta-analysis and a meta-regression approach. Akin to the results in Simmonds and Higgins (2007), we obtain analytic efficiency results for both methods under the assumption of gene-environment independence. The relative efficiency of the two methods depends on the ratio of within- versus between- cohort variability of the environmental covariate. We propose to use an adaptively weighted estimator (AWE), between meta-analysis and meta-regression, for the interaction parameter. The AWE retains full efficiency of the joint analysis using individual level data under certain natural assumptions. Lin and Zeng (2010a, b) showed that a multivariate inverse-variance weighted estimator also had asymptotically full efficiency as joint analysis using individual level data, if the estimates with full covariance matrices for all the common parameters are pooled across all studies. We show consistency of our work with Lin and Zeng (2010a, b). Without sacrificing much efficiency, the AWE uses only univariate summary statistics from each study, and bypasses issues with sharing individual level data or full covariance matrices across studies. We compare the performance of the methods both analytically and numerically. The methods are illustrated through meta-analysis of interaction between Single Nucleotide Polymorphisms in FTO gene and body mass index on high-density lipoprotein cholesterol data from a set of eight studies of type 2 diabetes.
PMCID: PMC4108593  PMID: 24801060
2.  Persistence of HIV-1 Transmitted Drug Resistance Mutations 
The Journal of Infectious Diseases  2013;208(9):1459-1463.
There are few data on the persistence of individual human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) mutations in the absence of selective drug pressure. We studied 313 patients in whom TDR mutations were detected at their first resistance test and who had a subsequent test performed while ART-naive. The rate at which mutations became undetectable was estimated using exponential regression accounting for interval censoring. Most thymidine analogue mutations (TAMs) and T215 revertants (but not T215F/Y) were found to be highly stable, with NNRTI and PI mutations being relatively less persistent. Our estimates are important for informing HIV transmission models.
PMCID: PMC3789571  PMID: 23904291
persistence; transmitted; HIV-1; resistance; mutations
3.  Low frequency of genotypic resistance in HIV-1-infected patients failing an atazanavir-containing regimen: a clinical cohort study 
Dolling, David I. | Dunn, David T. | Sutherland, Katherine A. | Pillay, Deenan | Mbisa, Jean L. | Parry, Chris M. | Post, Frank A. | Sabin, Caroline A. | Cane, Patricia A. | Aitken, Celia | Asboe, David | Webster, Daniel | Cane, Patricia | Castro, Hannah | Dunn, David | Dolling, David | Chadwick, David | Churchill, Duncan | Clark, Duncan | Collins, Simon | Delpech, Valerie | Geretti, Anna Maria | Goldberg, David | Hale, Antony | Hué, Stéphane | Kaye, Steve | Kellam, Paul | Lazarus, Linda | Leigh-Brown, Andrew | Mackie, Nicola | Orkin, Chloe | Rice, Philip | Pillay, Deenan | Phillips, Andrew | Sabin, Caroline | Smit, Erasmus | Templeton, Kate | Tilston, Peter | Tong, William | Williams, Ian | Zhang, Hongyi | Zuckerman, Mark | Greatorex, Jane | Wildfire, Adrian | O'Shea, Siobhan | Mullen, Jane | Mbisa, Tamyo | Cox, Alison | Tandy, Richard | Hale, Tony | Fawcett, Tracy | Hopkins, Mark | Ashton, Lynn | Booth, Claire | Garcia-Diaz, Ana | Shepherd, Jill | Schmid, Matthias L. | Payne, Brendan | Hay, Phillip | Rice, Phillip | Paynter, Mary | Bibby, David | Kirk, Stuart | MacLean, Alasdair | Gunson, Rory | Coughlin, Kate | Fearnhill, Esther | Fradette, Lorraine | Porter, Kholoud | Ainsworth, Jonathan | Anderson, Jane | Babiker, Abdel | Fisher, Martin | Gazzard, Brian | Gilson, Richard | Gompels, Mark | Hill, Teresa | Johnson, Margaret | Kegg, Stephen | Leen, Clifford | Nelson, Mark | Palfreeman, Adrian | Post, Frank | Sachikonye, Memory | Schwenk, Achim | Walsh, John | Huntington, Susie | Jose, Sophie | Thornton, Alicia | Glabay, Adam | Orkin, C. | Garrett, N. | Lynch, J. | Hand, J. | de Souza, C. | Fisher, M. | Perry, N. | Tilbury, S. | Gazzard, B. | Nelson, M. | Waxman, M. | Asboe, D. | Mandalia, S. | Delpech, V. | Anderson, J. | Munshi, S. | Korat, H. | Welch, J. | Poulton, M. | MacDonald, C. | Gleisner, Z. | Campbell, L. | Gilson, R. | Brima, N. | Williams, I. | Schwenk, A. | Ainsworth, J. | Wood, C. | Miller, S. | Johnson, M. | Youle, M. | Lampe, F. | Smith, C. | Grabowska, H. | Chaloner, C. | Puradiredja, D. | Walsh, J. | Weber, J. | Ramzan, F. | Mackie, N. | Winston, A. | Leen, C. | Wilson, A. | Allan, S. | Palfreeman, A. | Moore, A. | Wakeman, K.
Journal of Antimicrobial Chemotherapy  2013;68(10):2339-2343.
To determine protease mutations that develop at viral failure for protease inhibitor (PI)-naive patients on a regimen containing the PI atazanavir.
Resistance tests on patients failing atazanavir, conducted as part of routine clinical care in a multicentre observational study, were randomly matched by subtype to resistance tests from PI-naive controls to account for natural polymorphisms. Mutations from the consensus B sequence across the protease region were analysed for association and defined using the IAS-USA 2011 classification list.
Four hundred and five of 2528 (16%) patients failed therapy containing atazanavir as a first PI over a median (IQR) follow-up of 1.76 (0.84–3.15) years and 322 resistance tests were available for analysis. Recognized major atazanavir mutations were found in six atazanavir-experienced patients (P < 0.001), including I50L and N88S. The minor mutations most strongly associated with atazanavir experience were M36I, M46I, F53L, A71V, V82T and I85V (P < 0.05). Multiple novel mutations, I15S, L19T, K43T, L63P/V, K70Q, V77I and L89I/T/V, were also associated with atazanavir experience.
Viral failure on atazanavir-containing regimens was not common and major resistance mutations were rare, suggesting that adherence may be a major contributor to viral failure. Novel mutations were described that have not been previously documented.
PMCID: PMC3772741  PMID: 23711895
HIV; drug resistance mutations; naive patients; protease inhibitors; virological failure
4.  Smoking and Genetic Risk Variation across Populations of European, Asian, and African-American Ancestry - A Meta-analysis of Chromosome 15q25 
Genetic epidemiology  2012;36(4):340-351.
Recent meta-analyses of European ancestry subjects show strong evidence for association between smoking quantity and multiple genetic variants on chromosome 15q25. This meta-analysis extends the examination of association between distinct genes in the CHRNA5-CHRNA3-CHRNB4 region and smoking quantity to Asian and African American populations to confirm and refine specific reported associations.
Association results for a dichotomized cigarettes smoked per day (CPD) phenotype in 27 datasets (European ancestry (N=14,786), Asian (N=6,889), and African American (N=10,912) for a total of 32,587 smokers) were meta-analyzed by population and results were compared across all three populations.
We demonstrate association between smoking quantity and markers in the chromosome 15q25 region across all three populations, and narrow the region of association. Of the variants tested, only rs16969968 is associated with smoking (p < 0.01) in each of these three populations (OR=1.33, 95%C.I.=1.25–1.42, p=1.1×10−17 in meta-analysis across all population samples). Additional variants displayed a consistent signal in both European ancestry and Asian datasets, but not in African Americans.
The observed consistent association of rs16969968 with heavy smoking across multiple populations, combined with its known biological significance, suggests rs16969968 is most likely a functional variant that alters risk for heavy smoking. We interpret additional association results that differ across populations as providing evidence for additional functional variants, but we are unable to further localize the source of this association. Using the cross-population study paradigm provides valuable insights to narrow regions of interest and inform future biological experiments.
PMCID: PMC3387741  PMID: 22539395
smoking; genetics; meta-analysis; cross-population
5.  Fluorescent signatures for variable DNA sequences 
Nucleic Acids Research  2012;40(21):e164.
Life abounds with genetic variations writ in sequences that are often only a few hundred nucleotides long. Rapid detection of these variations for identification of genetic diseases, pathogens and organisms has become the mainstay of molecular science and medicine. This report describes a new, highly informative closed-tube polymerase chain reaction (PCR) strategy for analysis of both known and unknown sequence variations. It combines efficient quantitative amplification of single-stranded DNA targets through LATE-PCR with sets of Lights-On/Lights-Off probes that hybridize to their target sequences over a broad temperature range. Contiguous pairs of Lights-On/Lights-Off probes of the same fluorescent color are used to scan hundreds of nucleotides for the presence of mutations. Sets of probes in different colors can be combined in the same tube to analyze even longer single-stranded targets. Each set of hybridized Lights-On/Lights-Off probes generates a composite fluorescent contour, which is mathematically converted to a sequence-specific fluorescent signature. The versatility and broad utility of this new technology is illustrated in this report by characterization of variant sequences in three different DNA targets: the rpoB gene of Mycobacterium tuberculosis, a sequence in the mitochondrial cytochrome C oxidase subunit 1 gene of nematodes and the V3 hypervariable region of the bacterial 16 s ribosomal RNA gene. We anticipate widespread use of these technologies for diagnostics, species identification and basic research.
PMCID: PMC3505974  PMID: 22879378
6.  Trauma Center-Based Surveillance of Nontraffic Pedestrian Injury among California Children 
Every year in the United States, thousands of young children are injured by passenger vehicles in driveways or parking areas. Little is known about risk factors, and incidence rates are difficult to estimate because ascertainment using police collision reports or media sources is incomplete. This study used surveillance at trauma centers to identify incidents and parent interviews to obtain detailed information on incidents, vehicles, and children.
Eight California trauma centers conducted surveillance of nontraffic pedestrian collision injury to children aged 14 years or younger from January 2005 to July 2007. Three of these centers conducted follow-up interviews with family members.
Ninety-four injured children were identified. Nine children (10%) suffered fatal injury. Seventy children (74%) were 4 years old or younger. Family members of 21 victims from this study (23%) completed an interview. Of these 21 interviewed victims, 17 (81%) were male and 13 (62%) were 1 or 2 years old. In 13 cases (62%), the child was backed over, and the driver was the mother or father in 11 cases (52%). Fifteen cases (71%) involved a sport utility vehicle, pickup truck, or van. Most collisions occurred in a residential driveway.
Trauma center surveillance can be used for case ascertainment and for collecting information on circumstances of nontraffic pedestrian injuries. Adoption of a specific external cause-of-injury code would allow passive surveillance of these injuries. Research is needed to understand the contributions of family, vehicular, and environmental characteristics and injury risk to inform prevention efforts.
PMCID: PMC3415800  PMID: 22900102
7.  Gli3Xt−J/Xt−J mice exhibit lambdoid suture craniosynostosis which results from altered osteoprogenitor proliferation and differentiation 
Human Molecular Genetics  2010;19(17):3457-3467.
Gli3 is a zinc-finger transcription factor whose activity is dependent on the level of hedgehog (Hh) ligand. Hh signaling has key roles during endochondral ossification; however, its role in intramembranous ossification is still unclear. In this study, we show that Gli3 performs a dual role in regulating both osteoprogenitor proliferation and osteoblast differentiation during intramembranous ossification. We discovered that Gli3Xt−J/Xt−J mice, which represent a Gli3-null allele, exhibit craniosynostosis of the lambdoid sutures and that this is accompanied by increased osteoprogenitor proliferation and differentiation. These cellular changes are preceded by ectopic expression of the Hh receptor Patched1 and reduced expression of the transcription factor Twist1 in the sutural mesenchyme. Twist1 is known to delay osteogenesis by binding to and inhibiting the transcription factor Runx2. We found that Runx2 expression in the lambdoid suture was altered in a pattern complimentary to that of Twist1. We therefore propose that loss of Gli3 results in a Twist1-, Runx2-dependent expansion of the sutural osteoprogenitor population as well as enhanced osteoblastic differentiation which results in a bony bridge forming between the parietal and interparietal bones. We show that FGF2 will induce Twist1, normalize osteoprogenitor proliferation and differentiation and rescue the lambdoid suture synostosis in Gli3Xt−J/Xt−J mice. Taken together, we define a novel role for Gli3 in osteoblast development; we describe the first mouse model of lambdoid suture craniosynostosis and show how craniosynostosis can be rescued in this model.
PMCID: PMC2916710  PMID: 20570969
8.  Quality control and quality assurance in genotypic data for genome-wide association studies 
Genetic epidemiology  2010;34(6):591-602.
Genome-wide scans of nucleotide variation in human subjects are providing an increasing number of replicated associations with complex disease traits. Most of the variants detected have small effects and, collectively, they account for a small fraction of the total genetic variance. Very large sample sizes are required to identify and validate findings. In this situation, even small sources of systematic or random error can cause spurious results or obscure real effects. The need for careful attention to data quality has been appreciated for some time in this field, and a number of strategies for quality control and quality assurance (QC/QA) have been developed. Here we extend these methods and describe a system of QC/QA for genotypic data in genome-wide association studies. This system includes some new approaches that (1) combine analysis of allelic probe intensities and called genotypes to distinguish gender misidentification from sex chromosome aberrations, (2) detect autosomal chromosome aberrations that may affect genotype calling accuracy, (3) infer DNA sample quality from relatedness and allelic intensities, (4) use duplicate concordance to infer SNP quality, (5) detect genotyping artifacts from dependence of Hardy-Weinberg equilibrium (HWE) test p-values on allelic frequency, and (6) demonstrate sensitivity of principal components analysis (PCA) to SNP selection. The methods are illustrated with examples from the ‘Gene Environment Association Studies’ (GENEVA) program. The results suggest several recommendations for QC/QA in the design and execution of genome-wide association studies.
PMCID: PMC3061487  PMID: 20718045
GWAS; DNA sample quality; genotyping artifact; Hardy-Weinberg equilibrium; chromosome aberration
9.  Inhibition of all-trans retinoic acid-induced granulocytic differentiation of WEHI-3B D+ cells by forced expression of SCL (TAL1) and GATA-1 
Leukemia research  2009;33(9):1249-1254.
All-trans retinoic acid (ATRA) induces granulocytic maturation of WEHI-3B D+ leukemia cells and LiCl enhances this maturation, while WEHI-3B D− cells are non-responsive to ATRA. Transfection of SCL, expressed in D− but absent in D+ cells, into D+ cells, caused resistance to ATRA, while transfection of GATA-1 into D+ cells produced resistance to the combination of ATRA and LiCl. SCL expression in D+ cells did not induce the expression of c-Kit, a putative target gene for SCL. LiCl, known to inhibit some kinases by displacing Mg2+, did not affect tyrosine kinase activity of the cytoplasmic domain of c-Kit.
PMCID: PMC2780339  PMID: 19230972
WEHI-3B D+; WEHI-3B D−; SCL (TAL1); GATA-1; All-trans retinoic acid (ATRA); Lithium chloride (LiCl); c-Kit
10.  Disruption of Fgf10/Fgfr2b-coordinated epithelial-mesenchymal interactions causes cleft palate 
Journal of Clinical Investigation  2004;113(12):1692-1700.
Classical research has suggested that early palate formation develops via epithelial-mesenchymal interactions, and in this study we reveal which signals control this process. Using Fgf10–/–, FGF receptor 2b–/– (Fgfr2b–/–), and Sonic hedgehog (Shh) mutant mice, which all exhibit cleft palate, we show that Shh is a downstream target of Fgf10/Fgfr2b signaling. Our results demonstrate that mesenchymal Fgf10 regulates the epithelial expression of Shh, which in turn signals back to the mesenchyme. This was confirmed by demonstrating that cell proliferation is decreased not only in the palatal epithelium but also in the mesenchyme of Fgfr2b–/– mice. These results reveal a new role for Fgf signaling in mammalian palate development. We show that coordinated epithelial-mesenchymal interactions are essential during the initial stages of palate development and require an Fgf-Shh signaling network.
PMCID: PMC420504  PMID: 15199404
11.  Enhancement by Poly-d-Lysine of Poly I: C-Induced Interferon Production in Mice 
Applied Microbiology  1970;19(5):867-869.
Poly-d-lysine of high molecular weight enhances interferon induction in mice by the double-stranded complex of polyinosinic and polycytidylic acids and is superior to diethylaminoethyl-dextran in this respect.
PMCID: PMC376805  PMID: 4316274
12.  ECD--a totally integrated database of Escherichia coli K12. 
Nucleic Acids Research  1994;22(17):3450-3455.
We have compiled the DNA sequence data for E. coli available from the GENBANK and EMBL data libraries and independently from the literature. Starting with this update of our Escherichia coli database (ECD release 20) we provide major changes compared to previous issues. This update not only represents another substantial increase in sequence information, it also allows now to find the exact physical location of each individual gene or regulatory region, even regarding discrepancies in nomenclature. In order to save space this printed version does not contain the database itself anymore, but we provide several examples. The complete database is publically available in electronic form together with a self explaining application program or as a flat file. The complete compilation including a full set of genetic map data and the E. coli protein index can be obtained in machine readable form from the EMBL data library as a part of the CD-ROM issue of the EMBL sequence database, released and updated every three months. After deletion of all detected overlaps a total of 2,878,364 individual bp is found to be determined till the end of June 1994. This corresponds to a total of 60.98% of the entire E. coli chromosome consisting of about 4,720 kbp. This number may actually be higher by 9161 bp derived from other strains of E. coli.
PMCID: PMC308300  PMID: 7937044
13.  Role of Bed Nucleus of the Stria Terminalis Corticotrophin-Releasing Factor Receptors in Frustration Stress-Induced Binge-Like Palatable Food Consumption in Female Rats with a History of Food Restriction 
The Journal of Neuroscience  2014;34(34):11316-11324.
We developed recently a binge-eating model in which female rats with a history of intermittent food restriction show binge-like palatable food consumption after 15 min exposure to the sight of the palatable food. This “frustration stress” manipulation also activates the hypothalamic–pituitary–adrenal stress axis. Here, we determined the role of the stress neurohormone corticotropin-releasing factor (CRF) in stress-induced binge eating in our model. We also assessed the role of CRF receptors in the bed nucleus of the stria terminalis (BNST), a brain region implicated in stress responses and stress-induced drug seeking, in stress-induced binge eating. We used four groups that were first exposed or not exposed to repeated intermittent cycles of regular chow food restriction during which they were also given intermittent access to high-caloric palatable food. On the test day, we either exposed or did not expose the rats to the sight of the palatable food for 15 min (frustration stress) before assessing food consumption for 2 h. We found that systemic injections of the CRF1 receptor antagonist R121919 (2,5-dimethyl-3-(6-dimethyl-4-methylpyridin-3-yl)-7 dipropylamino pyrazolo[1,5-a]pyrimidine) (10–20 mg/kg) and BNST (25–50 ng/side) or ventricular (1000 ng) injections of the nonselective CRF receptor antagonist d-Phe-CRF(12–41) decreased frustration stress-induced binge eating in rats with a history of food restriction. Frustration stress also increased Fos (a neuronal activity marker) expression in ventral and dorsal BNST. Results demonstrate a critical role of CRF receptors in BNST in stress-induced binge eating in our rat model. CRF1 receptor antagonists may represent a novel pharmacological treatment for bingeing-related eating disorders.
PMCID: PMC4138341  PMID: 25143612
binge eating; BNST; CRF1 receptor antagonist; palatable food; R121919; stress and food restriction
14.  Pediatric injury patterns by year of age 
Journal of pediatric surgery  2013;48(6):1384-1388.
Since trauma is the leading cause of death and disability among children, understanding injury patterns may reduce morbidity and mortality through targeted prevention efforts. The purpose of this study was to identify pediatric injury patterns by year of age using a large national database.
We searched the National Trauma Database (NTDB) Research Data Set 7.0 for patients aged 0–18 years with the following relevant ICD-9 external-cause-of-injury codes (e-codes). We also reviewed our institutional trauma registry data (1999–2009). Data were analyzed using χ2 analysis and ANOVA with significance defined as p < 0.05.
We identified 354,196 pediatric trauma patients. The leading MOI were motor-vehicle collisions (MVC) for ages 10–18 years and falls for ages 0–9 years. Fire was the second leading MOI among 1-year-olds, but not a major MOI in other age groups. Penetrating trauma was the MOI for 21% of injuries among adolescents with public or no insurance (versus 7.5% adolescents with private insurance). Injury severity scores were highest for children < 1 year old and children 14–18 years old. Our review of 1209 patients from our institution yielded additional detail.
MVC and falls remain leading pediatric MOI. In our year-of-age analysis, we found several interesting trends, including a higher-than-expected rate of penetrating trauma. Our findings may support targeted injury prevention efforts.
PMCID: PMC4336172  PMID: 23845634
Trauma; Pediatric; Age distribution; Mechanism of injury; Insurance; E-code
15.  Interferon Lambda Alleles Predict Innate Antiviral Immune Responses and Hepatitis C Virus Permissiveness 
Cell host & microbe  2014;15(2):190-202.
Hepatitis C virus (HCV) infection can result in viral chronicity or clearance. Although host genetics and particularly genetic variation in the interferon lambda (IFNL) locus are associated with spontaneous HCV clearance and treatment success, the mechanisms guiding these clinical outcomes remain unknown. Using a laser capture microdissection-driven unbiased systems virology approach, we isolated and transcriptionally profiled HCV-infected and adjacent primary human hepatocytes (PHH) approaching single cell resolution. An innate antiviral immune signature dominated the transcriptional response, but differed in magnitude and diversity between HCV-infected and adjacent cells. Molecular signatures associated with more effective antiviral control were determined by comparing donors with high and low infection frequencies. Cells from donors with clinically unfavorable IFNL genotypes were infected at a greater frequency and exhibited dampened antiviral and cell death responses. These data suggest that early virus-host interactions, particularly host genetics and induction of innate immunity, critically determine the outcome of HCV infection.
PMCID: PMC4104123  PMID: 24528865
16.  Enhancing the Careers of Under-Represented Junior Faculty in Biomedical Research: The Summer Institute Program to Increase Diversity (SIPID) 
The Summer Institute Program to Increase Diversity (SIPID) in Health-Related Research is a career advancement opportunity sponsored by the National Heart, Lung, and Blood Institute. Three mentored programs address difficulties experienced by junior investigators in establishing independent research careers and academic advancement. Aims are to increase the number of faculty from under-represented minority groups who successfully compete for external research funding.
Data were collected using a centralized data-entry system from three Summer Institutes. Outcomes include mentees’ satisfaction rating about the program, grant and publications productivity and specific comments.
Fifty-eight junior faculty mentees (38% male) noticeably improved their rates of preparing/submitting grant applications and publications, with a 18–23% increase in confidence levels in planning and conducting research. According to survey comments, the training received in grantsmanship skills and one-on-one mentoring were the most valuable program components.
The SIPID mentoring program was highly valued by the junior faculty mentees. The program will continue in 2011–2014 as PRIDE (PRogram to Increase Diversity among individuals Engaged in health-related research). Long-term follow-up of current mentees will be indexed at five years post training (2013). In summary, these mentoring programs hope to continue increasing the diversity of the next generation of scientists in biomedical research.
PMCID: PMC4324679
17.  Synovial fluid pharmacokinetics of tulathromycin, gamithromycin and florfenicol after a single subcutaneous dose in cattle 
Deep digital septic conditions represent some of the most refractory causes of severe lameness in cattle. The objective of this study was to determine the distribution of tulathromycin, gamithromycin and florfenicol into the synovial fluid of the metatarsophalangeal (MTP) joint of cattle after single subcutaneous administration of drug to evaluate the potential usefulness of these single-dose, long-acting antimicrobials for treating bacterial infections of the joints in cattle.
Twelve cross-bred beef cows were randomly assigned to one of the drugs. Following subcutaneous administration, arthrocentesis of the left metatarsophalangeal joint was performed at various time points up to 240 hours post-injection, and samples were analyzed for drug concentration. In synovial fluid, florfenicol pharmacokinetic parameters estimates were: mean Tmax 7 +/− 2 hours, mean t½ 64.9 +/− 20.1 hours and mean AUC0-inf 154.0 +/− 26.2 ug*h/mL. Gamithromycin synovial fluid pharmacokinetic parameters estimates were: mean Tmax 8 hours, mean t½ 77.9 +/− 30.0 hours, and AUC0-inf 6.5 +/− 2.9 ug*h/mL. Tulathromycin pharmacokinetic parameters estimates in synovial fluid were: Tmax 19 +/− 10 hours, t½ 109 +/− 53.9 hours, and AUC0-inf 57.6 +/− 28.2 ug h/mL.
In conclusion, synovial fluid concentrations of all three antimicrobials were higher for a longer duration than that of previously reported plasma values. Although clinical data are needed to confirm microbiological efficacy, florfenicol achieved a synovial fluid concentration greater than the MIC90 for F. necrophorum for at least 6 days.
PMCID: PMC4332912
Synovial fluid; Tulathromycin; Gamithromycin; Florfenicol; Pharmacokinetics; Bovine
18.  Interferon-Stimulated Genes: A Complex Web of Host Defenses 
Annual review of immunology  2014;32:513-545.
Interferon-stimulated gene (ISG) products take on a number of diverse roles. Collectively, they are highly effective at resisting and controlling pathogens. In this review, we begin by introducing interferon (IFN) and the JAK-STAT signaling pathway to highlight features that impact ISG production. Next, we describe ways in which ISGs both enhance innate pathogen-sensing capabilities and negatively regulate signaling through the JAK-STAT pathway. Several ISGs that directly inhibit virus infection are described with an emphasis on those that impact early and late stages of the virus life cycle. Finally, we describe ongoing efforts to identify and characterize antiviral ISGs, and we provide a forward-looking perspective on the ISG landscape.
PMCID: PMC4313732  PMID: 24555472
innate immunity; pathogen recognition; desensitization; antiviral effectors
19.  α-2,3-Sialyltransferase Expression Level Impacts the Kinetics of Lipooligosaccharide Sialylation, Complement Resistance, and the Ability of Neisseria gonorrhoeae to Colonize the Murine Genital Tract 
mBio  2015;6(1):e02465-14.
Neisseria meningitidis and Neisseria gonorrhoeae modify the terminal lacto-N-neotetraose moiety of their lipooligosaccharide (LOS) with sialic acid. N. gonorrhoeae LOS sialylation blocks killing by complement, which is mediated at least in part by enhanced binding of the complement inhibitor factor H (FH). The role of LOS sialylation in resistance of N. meningitidis to serum killing is less well defined. Sialylation in each species is catalyzed by the enzyme LOS α-2,3-sialyltransferase (Lst). Previous studies have shown increased Lst activity in N. gonorrhoeae compared to N. meningitidis due to an ~5-fold increase in lst transcription. Using isogenic N. gonorrhoeae strains engineered to express gonococcal lst from either the N. gonorrhoeae or N. meningitidis lst promoter, we show that decreased expression of lst (driven by the N. meningitidis promoter) reduced LOS sialylation as determined by less incorporation of tritium-labeled cytidine monophospho-N-acetylneuraminic acid (CMP-NANA; the donor molecule for sialic acid). Diminished LOS sialylation resulted in reduced rates of FH binding and increased pathway activation compared to N. gonorrhoeae promoter-driven lst expression. The N. meningitidis lst promoter generated sufficient Lst to sialylate N. gonorrhoeae LOS in vivo, and the level of sialylation after 24 h in the mouse genital tract was sufficient to mediate resistance to human serum ex vivo. Despite demonstrable LOS sialylation in vivo, gonococci harboring the N. meningitidis lst promoter were outcompeted by those with the N. gonorrhoeae lst promoter during coinfection of the vaginal tract of estradiol-treated mice. These data highlight the importance of high lst expression levels for gonococcal pathogenesis.
IMPORTANCE  Neisseria gonorrhoeae has become resistant to nearly every therapeutic antibiotic used and is listed as an “urgent threat” by the Centers for Disease Control and Prevention. Novel therapies are needed to combat drug-resistant N. gonorrhoeae. Gonococci express an α-2,3-sialyltransferase (Lst) that can scavenge sialic acid from the host and use it to modify lipooligosaccharide (LOS). Sialylation of gonococcal LOS converts serum-sensitive strains to serum resistance, decreases antibody binding, and combats killing by neutrophils and antimicrobial peptides. Mutant N. gonorrhoeae that lack Lst (cannot sialylate LOS) are attenuated in a mouse model. Lst expression levels differ among N. gonorrhoeae strains, and N. gonorrhoeae typically expresses more Lst than Neisseria meningitidis. Here we examined the significance of differential lst expression levels and determined that the level of LOS sialylation is critical to the ability of N. gonorrhoeae to combat the immune system and survive in an animal model. LOS sialylation may be an ideal target for novel therapies.
Neisseria gonorrhoeae has become resistant to nearly every therapeutic antibiotic used and is listed as an “urgent threat” by the Centers for Disease Control and Prevention. Novel therapies are needed to combat drug-resistant N. gonorrhoeae. Gonococci express an α-2,3-sialyltransferase (Lst) that can scavenge sialic acid from the host and use it to modify lipooligosaccharide (LOS). Sialylation of gonococcal LOS converts serum-sensitive strains to serum resistance, decreases antibody binding, and combats killing by neutrophils and antimicrobial peptides. Mutant N. gonorrhoeae that lack Lst (cannot sialylate LOS) are attenuated in a mouse model. Lst expression levels differ among N. gonorrhoeae strains, and N. gonorrhoeae typically expresses more Lst than Neisseria meningitidis. Here we examined the significance of differential lst expression levels and determined that the level of LOS sialylation is critical to the ability of N. gonorrhoeae to combat the immune system and survive in an animal model. LOS sialylation may be an ideal target for novel therapies.
PMCID: PMC4324315  PMID: 25650401
20.  Global Epistasis Makes Adaptation Predictable Despite Sequence-Level Stochasticity 
Science (New York, N.Y.)  2014;344(6191):1519-1522.
Epistatic interactions between mutations can make evolutionary trajectories contingent on the chance occurrence of initial mutations. We used experimental evolution in Saccharomyces cerevisiae to quantify this contingency, finding differences in adaptability between 64 closely related genotypes. Despite these differences, sequencing of 104 evolved clones showed that initial genotype did not constrain future mutational trajectories. Instead, reconstructed combinations of mutations revealed a pattern of diminishing returns epistasis: beneficial mutations have consistently smaller effects in fitter backgrounds. Taken together, these results show that beneficial mutations affecting a variety of biological processes are globally coupled: they interact strongly, but only through their combined effect on fitness. As a consequence, fitness evolution follows a predictable trajectory even though sequence-level adaptation is stochastic.
PMCID: PMC4314286  PMID: 24970088
21.  Human intracellular ISG15 prevents interferon-α/β over-amplification and auto-inflammation 
Nature  2014;517(7532):89-93.
Intracellular ISG15 is an interferon (IFN)-α/β-inducible ubiquitin-like modifier which can covalently bind other proteins in a process called ISGylation; it is an effector of IFN-α/β-dependent antiviral immunity in mice1–4. We previously published a study describing humans with inherited ISG15 deficiency but without unusually severe viral diseases5. We showed that these patients were prone to mycobacterial disease and that human ISG15 was non-redundant as an extracellular IFN-γ-inducing molecule. We show here that ISG15-deficient patients also display unanticipated cellular, immunological and clinical signs of enhanced IFN-α/β immunity, reminiscent of the Mendelian autoinflammatory interferonopathies Aicardi–Goutières syndrome and spondyloenchondrodysplasia6–9.We further show that an absence of intracellular ISG15 in the patients’ cells prevents the accumulation of USP1810,11, a potent negative regulator of IFN-α/β signalling, resulting in the enhancement and amplification of IFN-α/β responses. Human ISG15, therefore, is not only redundant for antiviral immunity, but is a key negative regulator of IFN-α/β immunity. In humans, intracellular ISG15 is IFN-α/β-inducible not to serve as a substrate for ISGylation-dependent antiviral immunity, but to ensure USP18-dependent regulation of IFN-α/β and prevention of IFN-α/β-dependent autoinflammation.
PMCID: PMC4303590  PMID: 25307056
22.  Assessment of training and technical assistance needs of Colorectal Cancer Control Program Grantees in the U.S. 
BMC Public Health  2015;15:49.
Practitioners often require training and technical assistance to build their capacity to select, adapt, and implement evidence-based interventions (EBIs). The CDC Colorectal Cancer Control Program (CRCCP) aims to promote CRC screening to increase population-level screening. This study identified the training and technical assistance (TA) needs and preferences for training related to the implementation of EBIs among CRCCP grantees.
Twenty-nine CRCCP grantees completed an online survey about their screening activities, training and technical assistance in 2012. They rated desire for training on various evidence-based strategies to increase cancer screening, evidence-based competencies, and program management topics. They also reported preferences for training formats and facilitators and barriers to trainings.
Many CRCCP grantees expressed the need for training with regards to specific EBIs, especially system-level and provider-directed EBIs to promote CRC screening. Grantees rated these EBIs as more difficult to implement than client-oriented EBIs. Grantees also reported a moderate need for training regarding finding EBIs, assessing organizational capacity, implementing selected EBIs, and conducting process and outcome evaluations. Other desired training topics reported with higher frequency were partnership development and data collection/evaluation. Grantees preferred training formats that were interactive such as on-site trainings, webinars or expert consultants.
Public health organizations need greater supports for adopting evidence-based interventions, working with organizational-level change, partnership development and data management. Future capacity building efforts for the adoption of EBIs should focus on systems or provider level interventions and key processes for health promotion and should be delivered in a variety of ways to assist local organizations in cancer prevention and control.
Electronic supplementary material
The online version of this article (doi:10.1186/s12889-015-1386-1) contains supplementary material, which is available to authorized users.
PMCID: PMC4318175  PMID: 25636329
Colorectal neoplasms; Early detection and screening; Technical assistance; Training; Evidence-based interventions; Cancer screening
23.  Multifaceted Activities of Type I Interferon Are Revealed by a Receptor Antagonist 
Science signaling  2014;7(327):ra50.
Type I interferons (IFNs), including various IFN-α isoforms and IFN-β, are a family of homologous, multifunctional cytokines. IFNs activate different cellular responses by binding to a common receptor that consists of two subunits, IFNAR1 and IFNAR2. In addition to stimulating antiviral responses, they also inhibit cell proliferation and modulate other immune responses. We characterized various IFNs, including a mutant IFN-α2 (IFN-1ant) that bound tightly to IFNAR2 but had markedly reduced binding to IFNAR1. Whereas IFN-1ant stimulated antiviral activity in a range of cell lines, it failed to elicit immunomodulatory and antiproliferative activities. The antiviral activities of the various IFNs tested depended on a set of IFN-sensitive genes (the “robust” genes) that were controlled by canonical IFN response elements and responded at low concentrations of IFNs. Conversely, these elements were not found in the promoters of genes required for the antiproliferative responses of IFNs (the “tunable” genes). The extent of expression of tunable genes was cell type–specific and correlated with the magnitude of the antiproliferative effects of the various IFNs. Although IFN-1ant induced the expression of robust genes similarly in five different cell lines, its antiviral activity was virus- and cell type–specific. Our findings suggest that IFN-1ant may be a therapeutic candidate for the treatment of specific viral infections without inducing the immunomodulatory and antiproliferative functions of wild-type IFN.
PMCID: PMC4311876  PMID: 24866020
24.  Assessing Complexity of Heart Rate Variability in People with Spinal Cord Injury using Local Scale Exponents 
Detrended fluctuation analysis (DFA) has been widely used to study dynamics of heart rate variability (HRV), which provides a quantitative parameter, the scaling exponent α, to represent the correlation properties of RR interval series. However, it has been demonstrated that HRV exhibits complex behavior that cannot be fully described by a single exponent. This study aimed to investigate whether local scale exponent α(t) with t being the time scale can reveal new features of HRV that cannot be reflected by DFA coefficients. To accurately estimate α(t), we developed an approach for correcting α(t) at small scales and verified the approach using simulated signals. We studied HRV in 12 subjects with spinal cord injury and 14 able-bodied controls during sitting and prone postures. The results showed that α(t) provides complementary views of HRV, suggesting that it may be used to evaluate the effects of SCI-induced autonomic damage on HRV.
PMCID: PMC4302051  PMID: 25571456
Heart rate variability; spinal cord injury; local scale exponent
25.  Future Directions Concerning the Impact of Childhood and Adolescent Adversities in the Field of Men’s Mental Health: The New York Declaration 
PMCID: PMC4298168  PMID: 25646158
men’s mental health; testosterone; child development; traumatology; psychotherapy

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