Last data update: Jun 17, 2024. (Total: 47034 publications since 2009)
Records 1-22 (of 22 Records) |
Query Trace: McWilliams L [original query] |
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Outbreak of multidrug-resistant Salmonella infections in people linked to pig ear pet treats, United States, 2015–2019: results of a multistate investigation
Nichols M , Stapleton GS , Rotstein DS , Gollarza L , Adams J , Caidi H , Chen J , Hodges A , Glover M , Peloquin S , Payne L , Norris A , DeLancey S , Donovan D , Dietrich S , Glaspie S , McWilliams K , Burgess E , Holben B , Pietrzen K , Benko S , Feldpausch E , Orel S , Neises D , Kline KE , Tobin B , Caron G , Viveiros B , Miller A , Turner C , Holmes-Talbot K , Mank L , Nishimura C , Nguyen TN , Hale S , Francois Watkins LK . Lancet Reg Health - Am 2024 34 Background: International distribution of contaminated foods can be a source of Salmonella infections in people and can contribute to the spread of antimicrobial-resistant bacteria across countries. We report an investigation led by the United States Centers for Disease Control and Prevention, the Food and Drug Administration (FDA), and state governmental officials into a multistate outbreak of salmonellosis linked to pig ear pet treats. Methods: Pig ear treats and companion dogs were tested for Salmonella by state officials and the FDA. Products were traced back to the country of origin when possible. Cases were defined as outbreak illnesses in people associated with one of seven Salmonella serotypes genetically related to samples from pig ear pet treats, with isolation dates from June 2015 to September 2019. Whole genome sequencing (WGS) of isolates was used to predict antimicrobial resistance. Findings: The outbreak included 154 human cases in 34 states. Of these, 107 of 122 (88%) patients reported dog contact, and 65 of 97 (67%) reported contact with pig ear pet treats. Salmonella was isolated from 137 pig ear treats, including some imported from Argentina, Brazil, and Colombia, and from four dogs. WGS predicted 77% (105/137) of human and 43% (58/135) of pig ear treat isolates were resistant to ≥3 antimicrobial classes. Interpretation: This was the first documented United States multistate outbreak of Salmonella infections linked to pig ear pet treats. This multidrug-resistant outbreak highlights the interconnectedness of human health and companion animal ownership and the need for zoonotic pathogen surveillance to prevent human illness resulting from internationally transported pet food products. Funding: Animal Feed Regulatory Program Standards award. Animal and product testing conducted by FDA Vet-LIRN was funded by Vet-LIRN infrastructure grants ( PAR-22-063). © 2024 |
SARS-CoV-2 Outbreak at a College with High COVID-19 Vaccination Coverage-Connecticut, August-September 2021.
Bart SM , Curtiss CC , Earnest R , Lobe-Costonis R , Peterson H , McWilliams C , Billig K , Hadler JL , Grubaugh ND , Arcelus VJ , Sosa LE . Clin Infect Dis 2022 75 S243-S250 BACKGROUND: During August-September 2021, a Connecticut college experienced a large SARS-CoV-2 Delta outbreak despite high (99%) vaccination coverage, indoor masking policies, and twice weekly reverse transcription-polymerase chain reaction (RT-PCR) testing. The Connecticut Department of Public Health investigated characteristics associated with infection and phylogenetic relationships among cases. METHODS: A case was a SARS-CoV-2 infection diagnosed by RT-PCR or antigen test during August-September 2021 in a student. College staff provided enrollment data, case information, and class rosters. An anonymous online student survey collected demographics, SARS-CoV-2 case and vaccination history, and activities the weekend before the outbreak. Multivariate logistic regression identified characteristics associated with infection. Phylogenetic analyses compared 115 student viral genome sequences with contemporaneous community genomes. RESULTS: Overall, 199/1788 students (11%) had lab-confirmed SARS-CoV-2 infection; most were fully vaccinated (194/199, 97%). Attack rates were highest among sophomores (72/414, 17%) and unvaccinated students (5/18, 28%). Attending in-person classes with an infectious student was not associated with infection (adjusted odds ratio [aOR] 1.0; 95%CI 0.5-2.2). Compared with uninfected students, students reporting an infection were more likely sophomores (aOR 3.3; 95%CI 1.1-10.7), attended parties/gatherings before the outbreak (aOR 2.8; 95%CI 1.3-6.4), and completed a vaccine series ≥180 days prior (aOR 5.5; 95%CI 1.8-16.2). Phylogenetic analyses suggested most cases derived from a common viral source. CONCLUSIONS: This college SARS-CoV-2 outbreak occurred in a highly vaccinated population with prevention strategies in place. Infection was associated with unmasked off-campus parties/gatherings, not in-person classes. Students should stay up-to-date on vaccination to reduce infection. |
Detection and Clinical Implications of Monovalent Rotavirus Vaccine-Derived Virus Strains in Children with Gastroenteritis in Alberta, Canada.
Zhuo R , Tarr G , Xie J , Freedman SB , Payne DC , Lee BE , McWilliams C , Chui L , Ali S , Pang X . J Clin Microbiol 2021 59 (11) Jcm0115421 Background: While rotavirus vaccine programs effectively protect against severe rotavirus gastroenteritis, rotavirus vaccine strains have been identified in the stool of vaccinated children and their close contacts suffering from acute gastroenteritis. The prevalence of vaccine strains, the emergence of vaccine-derived strains and their role in acute gastroenteritis are not well studied. Methods: We developed a Locked Nucleic Acid Reverse Transcription real-time PCR assay (LNA-RTqPCR) to detect the monovalent rotavirus vaccine (RV1) Rotarix non-structural protein 2 in children with acute gastroenteritis and healthy controls and validated it using sequence confirmed RV1 strains. The association between RV1-derived strains and gastroenteritis was determined using logistic regression. Results: The new assay exhibited 100% (95%CI: 91.7%, 100%) diagnostic sensitivity and 99.4% (95%CI: 96.2%, 100%) diagnostic specificity, with a detection limit of 9.86 copies/reaction and qPCR efficiency of 99.7%. Using this assay, we identified the presence of RV1-derived NSP2 sequences in 7.7% of rotavirus gastroenteritis cases and 98.6% of rotavirus positive healthy children (94.4% had previously received the RV1). Among gastroenteritis cases, those whose stool contained RV1-derived strains had milder gastroenteritis symptoms compared to that of natural rotavirus infections. We observed no significant association between RV1-derived strains and gastroenteritis (OR 0.98; 95% CI 0.60, 1.72). Conclusion: Our study demonstrated that the new assay is suitable for monitoring RV1-derived rotavirus strain circulation and that the RV1-derived strains are not associated with development of gastroenteritis symptoms. |
Development and application of a high throughput one-pot extraction protocol for quantitative LC-MS/MS analysis of phospholipids in serum and lipoprotein fractions in normolipidemic and dyslipidemic subjects
Gardner MS , Kuklenyik Z , Lehtikoski A , Carter KA , McWilliams LG , Kusovschi J , Bierbaum K , Jones JI , Rees J , Reis G , Pirkle JL , Barr JR . J Chromatogr B Analyt Technol Biomed Life Sci 2019 1118-1119 137-147 Progress toward better diagnosis and treatment of lipid metabolism-related diseases requires high throughput approaches for multiplexed quantitative analysis of structurally diverse lipids, including phospholipids (PLs). This work demonstrates a simplified "one-pot" phospholipid extraction protocol, as an alternative to conventional liquid-liquid extraction. Performed in a 96-well format, the extraction was coupled with high throughput UPLC and multiplexed tandem mass spectrometry (MS/MS) detection, allowing non-targeted quantification of phosphatidylcholines (PC), sphingomyelins (SM), lysophosphatidylcholines (LPC), phosphatidylethanolamines (PE), and phosphatidylinositols (PI). Using 50muL aliquots of serum samples from 110 individuals, lipoproteins were fractionated by size, and analyzed for phospholipids and non-polar lipids including free cholesterol (FC), cholesteryl esters (CEs) and triglycerides (TGs). Analysis of serum samples with wide range of Total-TG levels showed significant differences in PL composition. The correlations of molar ratios in lipoprotein size fractions, SM/PL with FC/PL, PE/PL with TG/CE, and PE/PL with PI/PL, demonstrate the applicability of the method for quantitative composition analysis of high, low and very-low density lipoproteins (HDL, LDL and VLDL), and characterization of lipid metabolism related disease states. |
Core lipid, surface lipid and apolipoprotein composition analysis of lipoprotein particles as a function of particle size in one workflow integrating asymmetric flow field-flow fractionation and liquid chromatography-tandem mass spectrometry
Kuklenyik Z , Jones JI , Gardner MS , Schieltz DM , Parks BA , Toth CA , Rees JC , Andrews ML , Carter K , Lehtikoski AK , McWilliams LG , Williamson YM , Bierbaum KP , Pirkle JL , Barr JR . PLoS One 2018 13 (4) e0194797 Lipoproteins are complex molecular assemblies that are key participants in the intricate cascade of extracellular lipid metabolism with important consequences in the formation of atherosclerotic lesions and the development of cardiovascular disease. Multiplexed mass spectrometry (MS) techniques have substantially improved the ability to characterize the composition of lipoproteins. However, these advanced MS techniques are limited by traditional pre-analytical fractionation techniques that compromise the structural integrity of lipoprotein particles during separation from serum or plasma. In this work, we applied a highly effective and gentle hydrodynamic size based fractionation technique, asymmetric flow field-flow fractionation (AF4), and integrated it into a comprehensive tandem mass spectrometry based workflow that was used for the measurement of apolipoproteins (apos A-I, A-II, A-IV, B, C-I, C-II, C-III and E), free cholesterol (FC), cholesterol esters (CE), triglycerides (TG), and phospholipids (PL) (phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and lysophosphatidylcholine (LPC)). Hydrodynamic size in each of 40 size fractions separated by AF4 was measured by dynamic light scattering. Measuring all major lipids and apolipoproteins in each size fraction and in the whole serum, using total of 0.1 ml, allowed the volumetric calculation of lipoprotein particle numbers and expression of composition in molar analyte per particle number ratios. Measurements in 110 serum samples showed substantive differences between size fractions of HDL and LDL. Lipoprotein composition within size fractions was expressed in molar ratios of analytes (A-I/A-II, C-II/C-I, C-II/C-III. E/C-III, FC/PL, SM/PL, PE/PL, and PI/PL), showing differences in sample categories with combinations of normal and high levels of Total-C and/or Total-TG. The agreement with previous studies indirectly validates the AF4-LC-MS/MS approach and demonstrates the potential of this workflow for characterization of lipoprotein composition in clinical studies using small volumes of archived frozen samples. |
Simultaneous quantification of free cholesterol, cholesteryl esters, and triglycerides without ester hydrolysis by UHPLC separation and in-source collision induced dissociation coupled MS/MS
Gardner MS , McWilliams LG , Jones JI , Kuklenyik Z , Pirkle JL , Barr JR . J Am Soc Mass Spectrom 2017 28 (11) 2319-2329 We demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 muL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot. Known representative mixtures of EC and TG species were used as calibrators with stable isotope labeled analogs as internal standards. The APCI MS source was operated with nitrogen source gas. Reproducible in-source CID was achieved with the use of optimal cone voltage (declustering potential), generating FC, EC, and TG lipid class-specific precursor fragment ions for multiple reaction monitoring (MRM). Using a representative mixture of purified FC, CE, and TG species as calibrators, the method accuracy was assessed with analysis of five inter-laboratory standardization materials, showing -10% bias for Total-C and -3% for Total-TG. Repeated duplicate analysis of a quality control pool showed intra-day and inter-day variation of 5% and 5.8% for FC, 5.2% and 8.5% for Total-C, and 4.1% and 7.7% for Total-TG. The applicability of the method was demonstrated on 32 serum samples and corresponding lipoprotein sub-fractions collected from normolipidemic, hypercholesterolemic, hypertriglyceridemic, and hyperlipidemic donors. The results show that in-source CID coupled with isotope dilution UHPLC-MS/MS is a viable high precision approach for translational research studies where samples are substantially diluted or the amounts of archived samples are limited. |
High throughput quantification of apolipoproteins A-I and B-100 by isotope dilution mass spectrometry targeting fast trypsin releasable peptides without reduction and alkylation
Parks BA , Schieltz DM , Andrews ML , Gardner MS , Rees JC , Toth CA , Jones JI , McWilliams LG , Kuklenyik Z , Pirkle JL , Barr JR . Proteomics Clin Appl 2017 11 PURPOSE: Apolipoprotein A-I (ApoA-I) and Apolipoprotein B-100 (ApoB-100) are amphipathic proteins that are strong predictors of cardiovascular disease risk. The traceable calibration of apolipoprotein assays is a persistent challenge, especially for ApoB-100, which cannot be solubilized in purified form. EXPERIMENTAL DESIGN: Simultaneous quantitation method for ApoA-I and ApoB-100 was developed using tryptic digestion without pre-digestion reduction and alkylation, followed by liquid chromatography separation coupled with isotope dilution mass spectrometry (IDMS) analysis. The accuracy of the method was assured by selecting structurally exposed signature peptides, optimal choice of detergent, protein:enzyme ratio, and incubation time. Peptide calibrators were value assigned by isobaric-tagging-IDMS amino acid analysis. RESULTS: The method reproducibility was validated in technical repeats of three serum samples, giving 2-3% intra-day CVs (N = 5) and <7% inter-day CVs (N = 21). The repeated analysis of inter-laboratory harmonization standards showed -1% difference for ApoA-I and -12% for ApoB-100 relative to the assigned value. The applicability of the method was demonstrated by repeated analysis of 24 patient samples with a wide range of total cholesterol and triglyceride levels. CONCLUSIONS AND CLINICAL RELEVANCE: The method is applicable for simultaneous analysis of ApoA-I and ApoB-100 in patient samples, and for characterization of serum pool calibrators for other analytical platforms. |
Differential activation of RAW 264.7 macrophages by size-segregated crystalline silica
Mischler SE , Cauda EG , Di Giuseppe M , McWilliams LJ , St Croix C , Sun M , Franks J , Ortiz LA . J Occup Med Toxicol 2016 11 57 BACKGROUND: Occupational exposure to crystalline silica is a well-established occupational hazard. Once in the lung, crystalline silica particles can result in the activation of alveolar macrophages (AM), potentially leading to silicosis, a fibrotic lung disease. Because the activation of alveolar macrophages is the beginning step in a complicated inflammatory cascade, it is necessary to define the particle characteristics resulting in this activation. The aim of this research was to determine the effect of the size of crystalline silica particles on the activation of macrophages. METHODS: RAW 264.7 macrophages were exposed to four different sizes of crystalline silica and their activation was measured using electron microscopy, reactive oxygen species (ROS) generation by mitochondria, and cytokine expression. RESULTS: These data identified differences in particle uptake and formation of subcellular organelles based on particle size. In addition, these data show that the smallest particles, with a geometric mean of 0.3 mum, significantly increase the generation of mitochondrial ROS and the expression of cytokines when compared to larger crystalline silica particles, with a geometric mean of 4.1 mum. CONCLUSION: In summary, this study presents novel data showing that crystalline silica particles with a geometric mean of 0.3 mum enhance the activation of AM when compared to larger silica particles usually represented in in vitro and in vivo research. |
Physiologic Effects from Using Tight- and Loose-Fitting Powered Air-Purifying Respirators on Inhaled Gases, Peak Pressures, and Inhalation Temperatures During Rest and Exercise
Sinkule EJ , Powell JB , Rubinstein EN , McWilliams L , Quinn T , Pugliese M . J Int Soc Respir Prot 2016 33 (2) 36-52 The goal of this investigation was to evaluate the physiologic stresses of powered air-purifying respirators (PAPRs) used by workers in many industries (e.g., health care, automobile repair, public safety, building trades, etc.) during rest and three levels of energy expenditure. Twelve men and twelve women wore one tight-fitting and three loose-fitting PAPRs at rest (REST) and while walking for four minutes at oxygen consumption (V̇O(2)) rates of 1.0 l·min(-1)(LOW), 2.0 l·min(-1) (MODERATE), and 3.0 l·min(-1) or maximum (HIGH). Minimum inhaled carbon dioxide concentration (F(I)CO(2)), maximum inhaled oxygen concentration (F(I)O(2)), peak inhalation pressure, and end inhalation temperature were measured continuously breath-by-breath. Repeated measures analysis of variance found that neither the main effect of gender, nor any interactions involving gender were significant. The highest minimum F(I)CO(2) among PAPRs occurred for MODERATE and HIGH energy expenditures while wearing the loose-fitting PAPR with the largest dead space. The lowest maximum F(I)O(2) was observed during HIGH intensity energy expenditure also for the loose-fitting PAPR with the largest dead space. Among all PAPR models, peak inhalation pressures were negative at V̇O(2) > LOW, suggesting that peak inhalation flow was greater than blower flow. Results using the variables reported here suggest that PAPRs used at various levels of energy expenditure may be tolerated among healthy workers. Further research is needed to determine the source of supplemented air when inhalation flow exceeds blower flow. |
On-column trypsin digestion coupled with LC-MS/MS for quantification of apolipoproteins
Toth CA , Kuklenyik Z , Jones JI , Parks BA , Gardner MS , Schieltz DM , Rees JC , Andrews ML , McWilliams LG , Pirkle JL , Barr JR . J Proteomics 2016 150 258-267 Apolipoproteins measured in plasma or serum are potential biomarkers for assessing metabolic irregularities that are associated with the development of cardiovascular disease (CVD). LC-MS/MS allows quantitative measurement of multiple apolipoproteins in the same sample run.However, the accuracy and precision of the LC-MS/MS measurement depends on the reproducibility of the enzymatic protein digestion step. With the application of an immobilized enzyme reactor (IMER), the reproducibility of the trypsin digestion can be controlled with high precision via flow rate, column volume and temperature. In this report, we demonstrate the application of an integrated IMER-LC-MS/MS platform for the simultaneous quantitative analysis of eight apolipoproteins. Using a dilution series of a characterized serum pool as calibrator, the method was validated by repeated analysis of pooled sera and individual serum samples with a wide range of lipid profiles, all showing intra-assay CV<4.4% and inter-assay CV<8%. In addition, the method was compared with traditional homogeneous digestion coupled LC-MS/MS for the quantification of apoA-I and apoB-100. Applied in large scale human population studies, this method can serve the translation of a wider panel of apolipoprotein biomarkers from research to clinical application. SIGNIFICANCE: Currently, the translation of apolipoprotein biomarkers to clinical application is impaired because of the high cost of large cohort studies using traditional single-analyte immunoassays. The application of on-line tryptic digestion coupled with LC-MS/MS analysis is an effective way to address this problem. In this work we demonstrate a high throughput, multiplexed, automated proteomics workflow for the simultaneous analysis of multiple proteins. |
Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome.
Machiela MJ , Zhou W , Karlins E , Sampson JN , Freedman ND , Yang Q , Hicks B , Dagnall C , Hautman C , Jacobs KB , Abnet CC , Aldrich MC , Amos C , Amundadottir LT , Arslan AA , Beane-Freeman LE , Berndt SI , Black A , Blot WJ , Bock CH , Bracci PM , Brinton LA , Bueno-de-Mesquita HB , Burdett L , Buring JE , Butler MA , Canzian F , Carreon T , Chaffee KG , Chang IS , Chatterjee N , Chen C , Chen C , Chen K , Chung CC , Cook LS , Crous Bou M , Cullen M , Davis FG , De Vivo I , Ding T , Doherty J , Duell EJ , Epstein CG , Fan JH , Figueroa JD , Fraumeni JF , Friedenreich CM , Fuchs CS , Gallinger S , Gao YT , Gapstur SM , Garcia-Closas M , Gaudet MM , Gaziano JM , Giles GG , Gillanders EM , Giovannucci EL , Goldin L , Goldstein AM , Haiman CA , Hallmans G , Hankinson SE , Harris CC , Henriksson R , Holly EA , Hong YC , Hoover RN , Hsiung CA , Hu N , Hu W , Hunter DJ , Hutchinson A , Jenab M , Johansen C , Khaw KT , Kim HN , Kim YH , Kim YT , Klein AP , Klein R , Koh WP , Kolonel LN , Kooperberg C , Kraft P , Krogh V , Kurtz RC , LaCroix A , Lan Q , Landi MT , Marchand LL , Li D , Liang X , Liao LM , Lin D , Liu J , Lissowska J , Lu L , Magliocco AM , Malats N , Matsuo K , McNeill LH , McWilliams RR , Melin BS , Mirabello L , Moore L , Olson SH , Orlow I , Park JY , Patino-Garcia A , Peplonska B , Peters U , Petersen GM , Pooler L , Prescott J , Prokunina-Olsson L , Purdue MP , Qiao YL , Rajaraman P , Real FX , Riboli E , Risch HA , Rodriguez-Santiago B , Ruder AM , Savage SA , Schumacher F , Schwartz AG , Schwartz KL , Seow A , Wendy Setiawan V , Severi G , Shen H , Sheng X , Shin MH , Shu XO , Silverman DT , Spitz MR , Stevens VL , Stolzenberg-Solomon R , Stram D , Tang ZZ , Taylor PR , Teras LR , Tobias GS , Van Den Berg D , Visvanathan K , Wacholder S , Wang JC , Wang Z , Wentzensen N , Wheeler W , White E , Wiencke JK , Wolpin BM , Wong MP , Wu C , Wu T , Wu X , Wu YL , Wunder JS , Xia L , Yang HP , Yang PC , Yu K , Zanetti KA , Zeleniuch-Jacquotte A , Zheng W , Zhou B , Ziegler RG , Perez-Jurado LA , Caporaso NE , Rothman N , Tucker M , Dean MC , Yeager M , Chanock SJ . Nat Commun 2016 7 11843 To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases. |
Technical assistance needs for successful implementation of couples HIV testing and counseling (CHTC) intervention for male couples at US HIV testing sites
Stephenson R , Grabbe KL , Sidibe T , McWilliams A , Sullivan PS . AIDS Behav 2015 20 (4) 841-7 The African couples HIV testing and counseling (CHTC) model, which focuses on heterosexual couples, was adapted for same-sex male couples in the US. This paper presents the results of a follow-up survey conducted with representatives of the agencies that received CHTC training. The paper aims to understand the post-training implementation and identify critical technical assistance gaps. There are clear needs for continual learning opportunities, focused on the key skills required for CHTC, and for resources aimed at tackling agency-level concerns about service provision and integration. Central to this is the need for implementation science research that can identify the messages that are effective in encouraging couples to utilize CHTC and test models of service integration. |
Characterization of large structural genetic mosaicism in human autosomes.
Machiela MJ , Zhou W , Sampson JN , Dean MC , Jacobs KB , Black A , Brinton LA , Chang IS , Chen C , Chen C , Chen K , Cook LS , Crous Bou M , De Vivo I , Doherty J , Friedenreich CM , Gaudet MM , Haiman CA , Hankinson SE , Hartge P , Henderson BE , Hong YC , Hosgood HD 3rd , Hsiung CA , Hu W , Hunter DJ , Jessop L , Kim HN , Kim YH , Kim YT , Klein R , Kraft P , Lan Q , Lin D , Liu J , Le Marchand L , Liang X , Lissowska J , Lu L , Magliocco AM , Matsuo K , Olson SH , Orlow I , Park JY , Pooler L , Prescott J , Rastogi R , Risch HA , Schumacher F , Seow A , Setiawan VW , Shen H , Sheng X , Shin MH , Shu XO , VanDen Berg D , Wang JC , Wentzensen N , Wong MP , Wu C , Wu T , Wu YL , Xia L , Yang HP , Yang PC , Zheng W , Zhou B , Abnet CC , Albanes D , Aldrich MC , Amos C , Amundadottir LT , Berndt SI , Blot WJ , Bock CH , Bracci PM , Burdett L , Buring JE , Butler MA , Carreon T , Chatterjee N , Chung CC , Cook MB , Cullen M , Davis FG , Ding T , Duell EJ , Epstein CG , Fan JH , Figueroa JD , Fraumeni JF Jr , Freedman ND , Fuchs CS , Gao YT , Gapstur SM , Patino-Garcia A , Garcia-Closas M , Gaziano JM , Giles GG , Gillanders EM , Giovannucci EL , Goldin L , Goldstein AM , Greene MH , Hallmans G , Harris CC , Henriksson R , Holly EA , Hoover RN , Hu N , Hutchinson A , Jenab M , Johansen C , Khaw KT , Koh WP , Kolonel LN , Kooperberg C , Krogh V , Kurtz RC , LaCroix A , Landgren A , Landi MT , Li D , Liao LM , Malats N , McGlynn KA , McNeill LH , McWilliams RR , Melin BS , Mirabello L , Peplonska B , Peters U , Petersen GM , Prokunina-Olsson L , Purdue M , Qiao YL , Rabe KG , Rajaraman P , Real FX , Riboli E , Rodriguez-Santiago B , Rothman N , Ruder AM , Savage SA , Schwartz AG , Schwartz KL , Sesso HD , Severi G , Silverman DT , Spitz MR , Stevens VL , Stolzenberg-Solomon R , Stram D , Tang ZZ , Taylor PR , Teras LR , Tobias GS , Viswanathan K , Wacholder S , Wang Z , Weinstein SJ , Wheeler W , White E , Wiencke JK , Wolpin BM , Wu X , Wunder JS , Yu K , Zanetti KA , Zeleniuch-Jacquotte A , Ziegler RG , de Andrade M , Barnes KC , Beaty TH , Bierut LJ , Desch KC , Doheny KF , Feenstra B , Ginsburg D , Heit JA , Kang JH , Laurie CA , Li JZ , Lowe WL , Marazita ML , Melbye M , Mirel DB , Murray JC , Nelson SC , Pasquale LR , Rice K , Wiggs JL , Wise A , Tucker M , Perez-Jurado LA , Laurie CC , Caporaso NE , Yeager M , Chanock SJ . Am J Hum Genet 2015 96 (3) 487-97 Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 x 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population. |
Quantification of ricin, RCA and comparison of enzymatic activity in 18 Ricinus communis cultivars by isotope dilution mass spectrometry
Schieltz DM , McWilliams LG , Kuklenyik Z , Prezioso SM , Carter AJ , Williamson YM , McGrath SC , Morse SA , Barr JR . Toxicon 2015 95 72-83 The seeds of the Ricinus communis (Castor bean) plant are the source of the economically important commodity castor oil. Castor seeds also contain the proteins ricin and R. communis agglutinin (RCA), two toxic lectins that are hazardous to human health. Radial immunodiffusion (RID) and the enzyme linked immunosorbent assay (ELISA) are two antibody-based methods commonly used to quantify ricin and RCA; however, antibodies currently used in these methods cannot distinguish between ricin and RCA due to the high sequence homology of the respective proteins. In this study, a technique combining antibody-based affinity capture with liquid chromatography and multiple reaction monitoring (MRM) mass spectrometry (MS) was used to quantify the amounts of ricin and RCA independently in extracts prepared from the seeds of eighteen representative cultivars of R. communis which were propagated under identical conditions. Additionally, liquid chromatography and MRM-MS was used to determine rRNA N-glycosidase activity for each cultivar and the overall activity in these cultivars was compared to a purified ricin standard. Of the cultivars studied, the average ricin content was 9.3 mg/g, the average RCA content was 9.9 mg/g, and the enzymatic activity agreed with the activity of a purified ricin reference within 35% relative activity. |
Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33.
Wang Z , Zhu B , Zhang M , Parikh H , Jia J , Chung CC , Sampson JN , Hoskins JW , Hutchinson A , Burdette L , Ibrahim A , Hautman C , Raj PS , Abnet CC , Adjei AA , Ahlbom A , Albanes D , Allen NE , Ambrosone CB , Aldrich M , Amiano P , Amos C , Andersson U , Andriole G Jr , Andrulis IL , Arici C , Arslan AA , Austin MA , Baris D , Barkauskas DA , Bassig BA , Beane Freeman LE , Berg CD , Berndt SI , Bertazzi PA , Biritwum RB , Black A , Blot W , Boeing H , Boffetta P , Bolton K , Boutron-Ruault MC , Bracci PM , Brennan P , Brinton LA , Brotzman M , Bueno-de-Mesquita HB , Buring JE , Butler MA , Cai Q , Cancel-Tassin G , Canzian F , Cao G , Caporaso NE , Carrato A , Carreon T , Carta A , Chang GC , Chang IS , Chang-Claude J , Che X , Chen CJ , Chen CY , Chen CH , Chen C , Chen KY , Chen YM , Chokkalingam AP , Chu LW , Clavel-Chapelon F , Colditz GA , Colt JS , Conti D , Cook MB , Cortessis VK , Crawford ED , Cussenot O , Davis FG , De Vivo I , Deng X , Ding T , Dinney CP , Di Stefano AL , Diver WR , Duell EJ , Elena JW , Fan JH , Feigelson HS , Feychting M , Figueroa JD , Flanagan AM , Fraumeni JF Jr , Freedman ND , Fridley BL , Fuchs CS , Gago-Dominguez M , Gallinger S , Gao YT , Gapstur SM , Garcia-Closas M , Garcia-Closas R , Gastier-Foster JM , Gaziano JM , Gerhard DS , Giffen CA , Giles GG , Gillanders EM , Giovannucci EL , Goggins M , Gokgoz N , Goldstein AM , Gonzalez C , Gorlick R , Greene MH , Gross M , Grossman HB , Grubb R 3rd , Gu J , Guan P , Haiman CA , Hallmans G , Hankinson SE , Harris CC , Hartge P , Hattinger C , Hayes RB , He Q , Helman L , Henderson BE , Henriksson R , Hoffman-Bolton J , Hohensee C , Holly EA , Hong YC , Hoover RN , Hosgood HD 3rd , Hsiao CF , Hsing AW , Hsiung CA , Hu N , Hu W , Hu Z , Huang MS , Hunter DJ , Inskip PD , Ito H , Jacobs EJ , Jacobs KB , Jenab M , Ji BT , Johansen C , Johansson M , Johnson A , Kaaks R , Kamat AM , Kamineni A , Karagas M , Khanna C , Khaw KT , Kim C , Kim IS , Kim YH , Kim YC , Kim YT , Kang CH , Jung YJ , Kitahara CM , Klein AP , Klein R , Kogevinas M , Koh WP , Kohno T , Kolonel LN , Kooperberg C , Kratz CP , Krogh V , Kunitoh H , Kurtz RC , Kurucu N , Lan Q , Lathrop M , Lau CC , Lecanda F , Lee KM , Lee MP , Le Marchand L , Lerner SP , Li D , Liao LM , Lim WY , Lin D , Lin J , Lindstrom S , Linet MS , Lissowska J , Liu J , Ljungberg B , Lloreta J , Lu D , Ma J , Malats N , Mannisto S , Marina N , Mastrangelo G , Matsuo K , McGlynn KA , McKean-Cowdin R , McNeill LH , McWilliams RR , Melin BS , Meltzer PS , Mensah JE , Miao X , Michaud DS , Mondul AM , Moore LE , Muir K , Niwa S , Olson SH , Orr N , Panico S , Park JY , Patel AV , Patino-Garcia A , Pavanello S , Peeters PH , Peplonska B , Peters U , Petersen GM , Picci P , Pike MC , Porru S , Prescott J , Pu X , Purdue MP , Qiao YL , Rajaraman P , Riboli E , Risch HA , Rodabough RJ , Rothman N , Ruder AM , Ryu JS , Sanson M , Schned A , Schumacher FR , Schwartz AG , Schwartz KL , Schwenn M , Scotlandi K , Seow A , Serra C , Serra M , Sesso HD , Severi G , Shen H , Shen M , Shete S , Shiraishi K , Shu XO , Siddiq A , Sierrasesumaga L , Sierri S , Sihoe AD , Silverman DT , Simon M , Southey MC , Spector L , Spitz M , Stampfer M , Stattin P , Stern MC , Stevens VL , Stolzenberg-Solomon RZ , Stram DO , Strom SS , Su WC , Sund M , Sung SW , Swerdlow A , Tan W , Tanaka H , Tang W , Tang ZZ , Tardon A , Tay E , Taylor PR , Tettey Y , Thomas DM , Tirabosco R , Tjonneland A , Tobias GS , Toro JR , Travis RC , Trichopoulos D , Troisi R , Truelove A , Tsai YH , Tucker MA , Tumino R , Van Den Berg D , Van Den Eeden SK , Vermeulen R , Vineis P , Visvanathan K , Vogel U , Wang C , Wang C , Wang J , Wang SS , Weiderpass E , Weinstein SJ , Wentzensen N , Wheeler W , White E , Wiencke JK , Wolk A , Wolpin BM , Wong MP , Wrensch M , Wu C , Wu T , Wu X , Wu YL , Wunder JS , Xiang YB , Xu J , Yang HP , Yang PC , Yatabe Y , Ye Y , Yeboah ED , Yin Z , Ying C , Yu CJ , Yu K , Yuan JM , Zanetti KA , Zeleniuch-Jacquotte A , Zheng W , Zhou B , Mirabello L , Savage SA , Kraft P , Chanock SJ , Yeager M , Landi MT , Shi J , Chatterjee N , Amundadottir LT . Hum Mol Genet 2014 23 (24) 6616-33 Genome-wide association studies (GWAS) have mapped risk alleles for at least ten distinct cancers to a small region of 63,000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (ASSET) across six distinct cancers in 34,248 cases and 45,036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single nucleotide polymorphisms (SNPs): five in the TERT gene (region 1: rs7726159, P=2.10x10-39; region 3: rs2853677, P=3.30x10-36 and PConditional=2.36x10-8; region 4: rs2736098, P=3.87x10-12 and PConditional=5.19x10-6, region 5: rs13172201, P=0.041 and PConditional=2.04x10-6; and region 6: rs10069690, P=7.49x10-15 and PConditional=5.35x10-7) and one in the neighboring CLPTM1L gene (region 2: rs451360; P=1.90x10-18 and PConditional=7.06x10-16). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele specific effects on DNA methylation were seen for a subset of risk loci indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci. |
Detectable clonal mosaicism and its relationship to aging and cancer.
Jacobs KB , Yeager M , Zhou W , Wacholder S , Wang Z , Rodriguez-Santiago B , Hutchinson A , Deng X , Liu C , Horner MJ , Cullen M , Epstein CG , Burdett L , Dean MC , Chatterjee N , Sampson J , Chung CC , Kovaks J , Gapstur SM , Stevens VL , Teras LT , Gaudet MM , Albanes D , Weinstein SJ , Virtamo J , Taylor PR , Freedman ND , Abnet CC , Goldstein AM , Hu N , Yu K , Yuan JM , Liao L , Ding T , Qiao YL , Gao YT , Koh WP , Xiang YB , Tang ZZ , Fan JH , Aldrich MC , Amos C , Blot WJ , Bock CH , Gillanders EM , Harris CC , Haiman CA , Henderson BE , Kolonel LN , Le Marchand L , McNeill LH , Rybicki BA , Schwartz AG , Signorello LB , Spitz MR , Wiencke JK , Wrensch M , Wu X , Zanetti KA , Ziegler RG , Figueroa JD , Garcia-Closas M , Malats N , Marenne G , Prokunina-Olsson L , Baris D , Schwenn M , Johnson A , Landi MT , Goldin L , Consonni D , Bertazzi PA , Rotunno M , Rajaraman P , Andersson U , Freeman LE , Berg CD , Buring JE , Butler MA , Carreon T , Feychting M , Ahlbom A , Gaziano JM , Giles GG , Hallmans G , Hankinson SE , Hartge P , Henriksson R , Inskip PD , Johansen C , Landgren A , McKean-Cowdin R , Michaud DS , Melin BS , Peters U , Ruder AM , Sesso HD , Severi G , Shu XO , Visvanathan K , White E , Wolk A , Zeleniuch-Jacquotte A , Zheng W , Silverman DT , Kogevinas M , Gonzalez JR , Villa O , Li D , Duell EJ , Risch HA , Olson SH , Kooperberg C , Wolpin BM , Jiao L , Hassan M , Wheeler W , Arslan AA , Bueno-de-Mesquita HB , Fuchs CS , Gallinger S , Gross MD , Holly EA , Klein AP , LaCroix A , Mandelson MT , Petersen G , Boutron-Ruault MC , Bracci PM , Canzian F , Chang K , Cotterchio M , Giovannucci EL , Goggins M , Hoffman Bolton JA , Jenab M , Khaw KT , Krogh V , Kurtz RC , McWilliams RR , Mendelsohn JB , Rabe KG , Riboli E , Tjønneland A , Tobias GS , Trichopoulos D , Elena JW , Yu H , Amundadottir L , Stolzenberg-Solomon RZ , Kraft P , Schumacher F , Stram D , Savage SA , Mirabello L , Andrulis IL , Wunder JS , Patiño García A , Sierrasesúmaga L , Barkauskas DA , Gorlick RG , Purdue M , Chow WH , Moore LE , Schwartz KL , Davis FG , Hsing AW , Berndt SI , Black A , Wentzensen N , Brinton LA , Lissowska J , Peplonska B , McGlynn KA , Cook MB , Graubard BI , Kratz CP , Greene MH , Erickson RL , Hunter DJ , Thomas G , Hoover RN , Real FX , Fraumeni JF Jr , Caporaso NE , Tucker M , Rothman N , Pérez-Jurado LA , Chanock SJ . Nat Genet 2012 44 (6) 651-8 In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 x 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 x 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases. |
Coal dust exposure and mortality from ischemic heart disease among a cohort of U.S. coal miners
Landen DD , Wassell JT , McWilliams L , Patel A . Am J Ind Med 2011 54 (10) 727-33 BACKGROUND: Particulate exposure from air pollution increases the risk of ischemic heart disease (IHD) mortality. Although coal miners are highly exposed to coal dust particulate, studies of IHD mortality risk among coal miners have had inconsistent results. Previous studies may have been biased by the healthy worker effect. METHODS: We examined the dose-response relationship between cumulative coal dust exposure, coal rank, and IHD mortality among a cohort of underground coal miners who participated in the National Study of Coal Workers' Pneumoconiosis. RESULTS: After adjusting for age, smoking, and body mass index, risk of IHD mortality increased at higher levels of coal dust exposure. Mortality risk was also associated with coal rank region. CONCLUSION: There was an increased risk of mortality from IHD associated with cumulative exposure to coal dust, and with coal rank. The effect of coal rank may be due differences in the composition of coal mine dust particulate. The association of risk of IHD mortality with cumulative particulate exposure is consistent with air pollution studies. Am. J. Ind. Med. (c) 2011 Wiley-Liss, Inc. |
Detection and quantification of ricin in beverages using isotope dilution tandem mass spectrometry
McGrath SC , Schieltz DM , McWilliams LG , Pirkle JL , Barr JR . Anal Chem 2011 83 (8) 2897-905 The toxic plant protein ricin has gained notoriety due to wide availability and potential use as a bioterrorism agent, with particular concern for food supply contamination. We have developed a sensitive and selective mass spectrometry-based method to detect ricin in tap water, 2% milk, apple juice, and orange juice. Ricin added to beverage matrices was extracted using antibody-bound magnetic beads and digested with trypsin. Absolute quantification was performed using isotope dilution mass spectrometry with a linear ion trap operating in product-ion-monitoring mode. The method allows for identification of ricin A chain and B chain and for distinction of ricin from ricin agglutinin within a single analytical run. Ricin-bound beads were also tested for deadenylase activity by incubation with a synthetic ssDNA oligomer. Depurination of the substrate by ricin was confirmed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). This method was used successfully to extract ricin from each beverage matrix. The activity of recovered ricin was assessed, and quantification was achieved, with a limit of detection of 10 fmol/mL (0.64 ng/mL). |
Analysis of active ricin and castor bean proteins in a ricin preparation, castor bean extract, and surface swabs from a public health investigation
Schieltz DM , McGrath SC , McWilliams LG , Rees J , Bowen MD , Kools JJ , Dauphin LA , Gomez-Saladin E , Newton BN , Stang HL , Vick MJ , Thomas J , Pirkle JL , Barr JR . Forensic Sci Int 2011 209 70-9 In late February 2008, law enforcement officials in Las Vegas, Nevada, discovered in a hotel room, a copy of The Anarchist Cookbook, suspected castor beans and a "white powder" thought to be a preparation of ricin. Ricin is a deadly toxin from the seed of the castor bean plant (Ricinus communis). The United States regulates the possession, use, and transfer of ricin and it is the only substance considered a warfare agent in both the Chemical and the Biological Weapons Conventions. Six samples obtained from the hotel room were analyzed by laboratories at the Centers for Disease Control and Prevention using a panel of biological and mass spectrometric assays. The biological assays (real time-PCR, time resolved fluorescence and cytotoxicity) provided presumptive evidence of active ricin in each of the samples. This initial screen was followed by an in-depth analysis using a novel, state-of-the-art mass spectrometry-based ricin functional assay and high sensitivity tandem mass spectrometry for protein identification. Mass spectrometric analysis positively identified ricin and confirmed that in each of the samples it was enzymatically active. The tandem mass spectrometry analysis used here is the most selective method available to detect ricin toxin. In each sample, ricin was unequivocally identified along with other R. communis plant proteins, including the highly homologous protein RCA120. Although database searches using tandem mass spectra acquired from the samples indicated that additional controlled substances were not present in these samples, the mass spectrometric results did provide extensive detail about the sample contents. To the best of our knowledge following a review of the available literature, this report describes the most detailed analysis of a white powder for a public health or forensic investigation involving ricin. |
Studies on botulinum neurotoxins type/C1 and mosaic/DC using endopep-MS and proteomics
Moura H , Terilli RR , Woolfitt AR , Gallegos-Candela M , McWilliams LG , Solano MI , Pirkle JL , Barr JR . FEMS Immunol Med Microbiol 2010 61 (3) 288-300 Botulinum neurotoxins (BoNTs) are very potent toxins and category A biological threat agents. BoNT serotypes/C1 and/D affect birds and mammals and can be potentially lethal to humans. We have previously described the usefulness of the Endopep-MS method to detect the activity of BoNT A through G. This report was followed by the application of the method to clinical samples. The activity of the BoNT serotypes associated with human disease (/A,/B,/E, and/F) was successfully detected. However, BoNT/C and/D require different conditions for fast substrate cleavage and a comprehensive description of a method to study BoNT/C and/D has not yet been reported. This work describes a new, optimized version of the Endopep-MS method to detect BoNTs/C1 and/DC either spiked directly in 20 muL of reaction buffer or spiked in a larger volume of buffer and further extracted using antibody-coated magnetic beads. It was found that the incubation temperature at 42 degrees C was more effective for both toxin serotypes, but each toxin serotype has an optimum cleavage pH. Additionally, we describe for the first time a proteomics study using a fast trypsin digestion method and label-free quantification of these toxin serotypes. |
Noise exposure and hearing loss among sand and gravel miners
Landen D , Wilkins S , Stephenson M , McWilliams L . J Occup Environ Hyg 2004 1 (8) 532-41 The objectives of this study were to describe workplace noise exposures, risk factors for hearing loss, and hearing levels among sand and gravel miners, and to determine whether full shift noise exposures resulted in changes in hearing thresholds from baseline values. Sand and gravel miners (n = 317) were interviewed regarding medical history, leisure-time and occupational noise exposure, other occupational exposures, and use of hearing protection. Audiometric tests were performed both before the work shift (following a 12-hour noise-free interval) and immediately following the work shift. Full shift noise dosimetry was conducted. Miners' noise exposures exceeded the Recommended Exposure Limit (REL) of the National Institute for Occupational Safety and Health (NIOSH) for 69% of workers, and exceeded the Mine Safety and Health Administration's action level for enrollment in a hearing conservation program for 41% of workers. Significantly higher noise exposures occurred among employees of small companies, among workers with a job classification of truck driver, among males, and among black workers. Hearing protection usage was low, with 48% of subjects reporting that they never used hearing protection. Hearing impairment, as defined by NIOSH, was present among 37% of 275 subjects with valid audiograms. Black male workers and white male workers had higher hearing thresholds than males from a comparison North Carolina population unexposed to industrial noise. Small but statistically significant changes in hearing thresholds occurred following full shift noise exposure among subjects who had good hearing sensitivity at baseline. In a logistic regression model, age and history of a past noisy job were significant predictors of hearing impairment. Overall, sand and gravel workers have excessive noise exposures and significant hearing loss, and demonstrate inadequate use of hearing protection. Well-designed hearing conservation programs, with reduction of noise exposure, are clearly needed. |
Kinetics of lethal factor and poly-D-glutamic acid antigenemia during inhalation anthrax in rhesus macaques
Boyer AE , Quinn CP , Hoffmaster AR , Kozel TR , Saile E , Marston CK , Percival A , Plikaytis BD , Woolfitt AR , Gallegos M , Sabourin P , McWilliams LG , Pirkle JL , Barr JR . Infect Immun 2009 77 (8) 3432-41 Systemic anthrax manifests as toxemia, rapidly disseminating septicemia, immune collapse, and death. Virulence factors include the anti-phagocytic gamma-linked poly-d-glutamic acid (PGA) capsule and two binary toxins, complexes of protective antigen (PA) with lethal factor (LF) and edema factor. We report the characterization of LF, PA, and PGA levels during the course of inhalation anthrax in five rhesus macaques. We describe bacteremia, blood differentials, and detection of the PA gene (pagA) by PCR analysis of the blood as confirmation of infection. For four of five animals tested, LF exhibited a triphasic kinetic profile. LF levels (mean +/- standard error [SE] between animals) were low at 24 h postchallenge (0.03 +/- 1.82 ng/ml), increased at 48 h to 39.53 +/- 0.12 ng/ml (phase 1), declined at 72 h to 13.31 +/- 0.24 ng/ml (phase 2), and increased at 96 h (82.78 +/- 2.01 ng/ml) and 120 h (185.12 +/- 5.68 ng/ml; phase 3). The fifth animal had an extended phase 2. PGA levels were triphasic; they were nondetectable at 24 h, increased at 48 h (2,037 +/- 2 ng/ml), declined at 72 h (14 +/- 0.2 ng/ml), and then increased at 96 h (3,401 +/- 8 ng/ml) and 120 h (6,004 +/- 187 ng/ml). Bacteremia was also triphasic: positive at 48 h, negative at 72 h, and positive at euthanasia. Blood neutrophils increased from preexposure (34.4% +/- 0.13%) to 48 h (75.6% +/- 0.08%) and declined at 72 h (62.4% +/- 0.05%). The 72-h declines may establish a "go/no go" turning point in infection, after which systemic bacteremia ensues and the host's condition deteriorates. This study emphasizes the value of LF detection as a tool for early diagnosis of inhalation anthrax before the onset of fulminant systemic infection. |
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