Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-30 (of 39 Records) |
Query Trace: Bond K[original query] |
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The ETS domain-containing hematopoietic transcription factor PU.1 mediates the induction of arachidonate 5-lipoxygenase by multi-walled carbon nanotubes in macrophages in vitro
Lim CS , Gu JK , Ma Q . Arch Toxicol 2024 Exposure to fibrogenic multi-walled carbon nanotubes (MWCNTs) induces the production of proinflammatory lipid mediators (LMs) in myeloid cells to instigate inflammation. The molecular underpinnings of LM production in nanotoxicity remain unclear. Here we report that PU.1, an ETS domain-containing master regulator of hematopoiesis, critically regulates the induction of arachidonate 5-lypoxygenase (Alox5) and the production of LMs. MWCNTs (Mitsui-7) at 2.5 or 10 µg/mL induced the expression of Alox5 in murine and human macrophages at both mRNA and protein levels, accompanied by marked elevation of chemotactic LM leukotriene B4 (LTB4). Induction is comparable to those by potent M1 inducers. Carbon black, an amorphous carbon material control, did not increase Alox5 expression or LTB4 production at equivalent doses. MWCNTs induced the expression of a heterologous luciferase reporter under the control of the murine Alox5 promoter. Deletional analysis of the 2 kb promoter uncovered multiple inhibitory and activating activities. The proximal 250 bp region had the largest activation that was further increased by MWCNTs. The Alox5 promoter contains four PU box-like enhancers. PU.1 bond to each of the enhancers constitutively, which was further increased by MWCNTs. Knockdown of PU.1 using specific small hairpin-RNA blocked the basal and induced expression of Alox5 and the production of LTB4 as well as prostaglandin E2. The results demonstrate a critical role of PU.1 in mediating MWCNTs-induced expression of Alox5 and production of proinflammatory LMs, revealing a molecular framework where the hematopoietic transcription factor PU.1 is activated to orchestrate multiple proinflammatory responses to sterile particulates. |
Associations between per- and polyfluoroalkyl substances (PFAS) and female sexual function in a preconception cohort
Schildroth S , Bond JC , Wesselink AK , Abrams J , Calafat AM , Cook Botelho J , White KO , Wegienka G , Hatch EE , Wise LA . Environ Res 2024 266 120556 BACKGROUND: Female sexual function is important for sexual well-being, general health, fertility, and relationship satisfaction. Distressing impairments in sexual function, clinically recognized as female sexual dysfunction (FSD), can manifest as issues with interest/desire, arousal, orgasm, and pain during vaginal penetration. Some evidence suggests that exposure to endocrine-disrupting chemicals may adversely affect female sexual function, but associations for per- and polyfluoroalkyl substances (PFAS) have not been previously evaluated. OBJECTIVE: We investigated associations between serum PFAS concentrations and female sexual function among U.S. pregnancy planners. METHODS: We used cross-sectional data from participants from Pregnancy Study Online (PRESTO), a prospective preconception cohort study. Participants reported sexual function and distress at baseline on two validated measures: a modified version of the Female Sexual Function Index-6 (FSFI-6) and the Female Sexual Distress Scale (FSDS). We quantified PFAS serum concentrations in samples collected in the preconception period (i.e., at baseline) using solid phase extraction-high performance liquid chromatography-isotope-dilution-mass spectrometry. Participants reported sociodemographic information on structured baseline questionnaires. We included 78 participants with complete PFAS and sexual function data and fit multivariable linear regression models to estimate mean differences in FSFI-6 scores (β) or percent differences (%) in FSDS scores per interquartile range (IQR) increase in PFAS concentrations, adjusting for age, annual household income, years of education, parity, and body mass index. We further investigated effect measure modification by parity (parous vs. nulliparous) in stratified models. RESULTS: An IQR increase in perfluorohexanesulfonic acid was associated with a 1.0-point decrease (95% CI = -1.8, -0.1) in reported FSFI-6 scores, reflecting poorer sexual function. PFAS were consistently associated with lower FSFI-6 scores among parous participants. PFAS were also associated, though imprecisely, with greater sexual distress. CONCLUSION: Some PFAS were associated with poorer sexual function among U.S. pregnancy planners, but future studies are needed to clarify the extent to which PFAS influences female sexual health. |
A bi-national sample-initiated retrospective outbreak investigation of Listeria monocytogenes infections in the United States and Canada linked to enoki mushrooms imported from China 2022-2023
Kirchner M , Palacios A , Cataldo N , Allen KL , Wellman A , Madad A , Jemaneh T , Jackson T , Ingram DT , Wagoner V , Hatch R , Baugher J , Burall L , Nieves K , Low M , Pederson G , DiPrete L , Sepcic V , Thomas D , Lozinak K , Urban S , Shannon K , Kafka E , Lackey A , Edwards L , Rosen HE , Bond C , Needham M , Locas A , Markell A , Chau K , Kong A , Hamel M , Kearney A , Salter M , Gieraltowski L , Bazaco MC , Viazis S , Conrad A . J Food Prot 2024 100413 ![]() ![]() In 2022, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), U.S. state and local partners, the Public Health Agency of Canada (PHAC), and the Canadian Food Inspection Agency (CFIA), conducted a bi-national sample-initiated retrospective outbreak investigation (SIROI) of Listeria monocytogenes illnesses linked to enoki mushrooms. The FDA and CDC investigated the first known L. monocytogenes outbreak linked to enoki mushrooms from 2016-2020, making the 2022 outbreak the second time this pathogen-commodity pair was investigated by FDA and CDC. The 2022 outbreak included six ill people, all of whom were hospitalized. Epidemiologic, laboratory, and traceback evidence led to multiple public health actions, including voluntary recalls by firms, public communications about the outbreak, and FDA's country-wide Import Alert for enoki mushrooms from China. This SIROI illustrates the importance of surveillance sampling, national and international coordination of efforts, and rapid information sharing to identify and stop foodborne outbreaks on a global scale. To reduce the risk of listeriosis illnesses linked to contaminated enoki mushrooms, public health and regulatory agencies in the United States and Canada remain committed to conducting comprehensive surveillance for Listeria in foods and in people, efficiently investigating identified outbreaks, and implementing control measures to potentially minimize the impact of future outbreaks. |
Enhanced surface accessibility of SARS-CoV-2 Omicron spike protein due to an altered glycosylation profile
Wang D , Zhang Z , Baudys J , Haynes C , Osman SH , Zhou B , Barr JR , Gumbart JC . ACS Infect Dis 2024 ![]() SARS-CoV-2 spike (S) proteins undergo extensive glycosylation, aiding in proper folding, enhancing stability, and evading host immune surveillance. In this study, we used mass spectrometric analysis to elucidate the N-glycosylation characteristics and disulfide bonding of recombinant spike proteins derived from the SARS-CoV-2 Omicron variant (B.1.1.529) in comparison with the D614G spike variant. Furthermore, we conducted microsecond-long molecular dynamics simulations on spike proteins to resolve how the different N-glycans impact spike conformational sampling in the two variants. Our findings reveal that the Omicron spike protein maintains an overall resemblance to the D614G spike variant in terms of site-specific glycan processing and disulfide bond formation. Nonetheless, alterations in glycans were observed at certain N-glycosylation sites. These changes, in synergy with mutations within the Omicron spike protein, result in increased surface accessibility of the macromolecule, including the ectodomain, receptor-binding domain, and N-terminal domain. Additionally, mutagenesis and pull-down assays reveal the role of glycosylation of a specific sequon (N149); furthermore, the correlation of MD simulation and HDX-MS identified several high-dynamic areas of the spike proteins. These insights contribute to our understanding of the interplay between structure and function, thereby advancing effective vaccination and therapeutic strategies. |
Comparative neurotranscriptomics reveal widespread species differences associated with bonding (preprint)
Tripp JA , Berrio A , McGraw LA , Matz MV , Davis JK , Inoue K , Thomas JW , Young LJ , Phelps SM . bioRxiv 2020 2020.12.07.415463 Background Pair bonding with a reproductive partner is rare among mammals but is an important feature of human social behavior. Decades of research on monogamous prairie voles (Microtus ochrogaster), along with comparative studies using the related non-bonding meadow vole (M. pennsylvanicus), have revealed many of the neural and molecular mechanisms necessary for pair-bond formation in that species. However, these studies have largely focused on just a few neuromodulatory systems. To test the hypothesis that neural gene expression differences underlie differential capacities to bond, we performed RNA-sequencing on tissue from three brain regions important for bonding and other social behaviors across bond-forming prairie voles and non-bonding meadow voles. We examined gene expression in the amygdala, hypothalamus, and combined ventral pallidum/nucleus accumbens in virgins and at three time points after mating to understand species differences in gene expression at baseline, in response to mating, and during bond formation.Results We first identified species and brain region as the factors most strongly associated with gene expression in our samples. Next, we found gene categories related to cell structure, translation and metabolism that differed in expression across species in virgins, as well as categories associated with cell structure, synaptic and neuroendocrine signaling, and transcription and translation that varied among the focal regions in our study. Additionally, we identified genes that were differentially expressed across species after mating in each of our regions of interest. These include genes involved in regulating transcription, neuron structure, and synaptic plasticity. Finally, we identified modules of co-regulated genes that were strongly correlated with brain region in both species, and modules that were correlated with post-mating time points in prairie voles but not meadow voles.Conclusions These results reinforce the importance of pre-mating differences that confer the ability to form pair bonds in prairie voles but not promiscuous species such as meadow voles. Gene ontology analysis supports the hypothesis that pair-bond formation involves transcriptional regulation, and changes in neuronal structure. Together, our results expand knowledge of the genes involved in the pair bonding process and open new avenues of research in the molecular mechanisms of bond formation.Competing Interest StatementThe authors have declared no competing interest.AMYAmygdalaAVPArginine-vasopressinFDRFalse discovery rateHTHypothalamusLFCLog (base 2) fold changeMEModule eigengeneMWUMann-Whitney U testOTOxytocinVP/NAcVentral pallidum/nucleus accumbens |
Discovery and Characterization of Pneumococcal Serogroup 36 Capsule Subtypes, Serotypes 36A and 36B.
Ganaie FA , Saad JS , Lo SW , McGee L , Bentley SD , van Tonder AJ , Hawkins P , Keenan JD , Calix JJ , Nahm MH . J Clin Microbiol 2023 61 (4) e0002423 ![]() Streptococcus pneumoniae can produce a wide breadth of antigenically diverse capsule types, a fact that poses a looming threat to the success of vaccines that target pneumococcal polysaccharide (PS) capsule. Yet, many pneumococcal capsule types remain undiscovered and/or uncharacterized. Prior sequence analysis of pneumococcal capsule synthesis (cps) loci suggested the existence of capsule subtypes among isolates identified as "serotype 36" according to conventional capsule typing methods. We discovered these subtypes represent two antigenically similar but distinguishable pneumococcal capsule serotypes, 36A and 36B. Biochemical analysis of their capsule PS structure reveals that both have the shared repeat unit backbone [→5)-α-d-Galf-(1→1)-d-Rib-ol-(5→P→6)-β-d-ManpNAc-(1→4)-β-d-Glcp-(1→] with two branching structures. Both serotypes have a β-d-Galp branch to Ribitol. Serotypes 36A and 36B differ by the presence of a α-d-Glcp-(1→3)-β-d-ManpNAc or α-d-Galp-(1→3)-β-d-ManpNAc branch, respectively. Comparison of the phylogenetically distant serogroup 9 and 36 cps loci, which all encode this distinguishing glycosidic bond, revealed that the incorporation of Glcp (in types 9N and 36A) versus Galp (in types 9A, 9V, 9L, and 36B) is associated with the identity of four amino acids in the cps-encoded glycosyltransferase WcjA. Identifying functional determinants of cps-encoded enzymes and their impact on capsule PS structure is key to improving the resolution and reliability of sequencing-based capsule typing methods and discovering novel capsule variants indistinguishable by conventional serotyping methods. |
Bi-national Outbreak of Salmonella Newport Infections Linked to Onions: the United States Experience.
McCormic ZD , Patel K , Higa J , Bancroft J , Donovan D , Edwards L , Cheng J , Adcock B , Bond C , Pereira E , Doyle M , Wise ME , Gieraltowski L . Epidemiol Infect 2022 150 1-23 ![]() ![]() From 2016-2019, dry bulb onions were the suspected cause of three multistate outbreaks in the United States. We investigated a large multistate outbreak of Salmonella Newport infections that caused illnesses in both the United States and Canada in 2020. Epidemiologic, laboratory and traceback investigations were conducted to determine the source of the infections, and data were shared among U.S. and Canadian public health officials. We identified 1127 U.S. illnesses from 48 states with illness onset dates ranging from 19 June to 11 September 2020. Sixty-six per cent of ill people reported consuming red onions in the week before illness onset. Thirty-five illness sub-clusters were identified during the investigation and seventy-four per cent of sub-clusters served red onions to customers during the exposure period. Traceback for the source of onions in illness sub-clusters identified a common onion grower in Bakersfield, CA as the source of red onions, and onions were recalled at this time. Although other strains of Salmonella Newport were identified in environmental samples collected at the Bakersfield, CA grower, extensive environmental and product testing did not yield the outbreak strain. This was the third largest U.S. foodborne Salmonella outbreak in the last 30 years. It is the first U.S. multistate outbreak with a confirmed link to dry bulb onions, and it was nearly 10-fold larger than prior outbreaks with a suspected link to onions. This outbreak is notable for its size and scope, as well as the international data sharing that led to implication of red onions as the primary cause of the outbreak. Although an environmental assessment at the grower identified several factors that likely contributed to the outbreak, no main reason was identified. The expedient identification of the outbreak vehicle and response of multiple public health agencies allowed for recall and removal of product from the marketplace, and rapid messaging to both the public and industry on actions to protect consumers; these features contributed to a decrease in cases and expeditious conclusion of the outbreak. |
SARS-CoV-2 testing and detection during peripartum hospitalizations among a multi-center cohort of pregnant persons, March 2020-February 2021.
Delahoy MJ , Munoz F , Li K , Arriola CS , Bond NL , Daugherty M , Ferber J , Ferguson N , Hadden L , Henderson JT , Irving SA , Juergens M , Kancharla V , Greenberg M , Odouli R , Newes-Adeyi G , Nicholson EG , Reichle L , Sanyang M , Snead M , Dawood FS , Naleway AL . Clin Infect Dis 2022 76 (3) e51-e59 BACKGROUND: Identifying SARS-CoV-2 infections during peripartum hospitalizations is important to guide care, implement prevention measures, and understand infection burden. METHODS: This cross-sectional analysis used electronic health record data from hospitalizations during which pregnancies ended (peripartum hospitalizations) among a cohort of pregnant persons at 3 U.S. integrated healthcare networks (Sites 1-3). Maternal demographic, medical encounter, SARS-CoV-2 testing, and pregnancy and neonatal outcome information was extracted for persons with estimated delivery and pregnancy end dates during March 2020-February 2021 and ≥1 prenatal care record. Site-stratified multivariable logistic regression was used to identify factors associated with testing and compare pregnancy and neonatal outcomes among persons tested. RESULTS: Among 17,858 pregnant persons, 10,863 (60.8%) had peripartum SARS-CoV-2 testing; 222/10,683 (2.0%) had positive results. Testing prevalence varied by site and was lower during March-May 2020. Factors associated with higher peripartum SARS-CoV-2 testing odds were Asian race (adjusted odds ratio [aOR]: 1.36; 95% CI: 1.03-1.79; referent: White) (Site 1), Hispanic or Latina ethnicity (aOR: 1.33; 95% CI: 1.08-1.64) (Site 2), peripartum Medicaid coverage (aOR: 1.33; 95% CI: 1.06-1.66) (Site 1), and preterm hospitalization (aOR: 1.69; 95% CI: 1.19-2.39 [Site 1]; aOR: 1.39; 95% CI: 1.03-1.88 [Site 2]). CONCLUSIONS: Findings highlight potential disparities in SARS-CoV-2 peripartum testing by demographic and pregnancy characteristics. Testing practice variations should be considered when interpreting studies relying on convenience samples of pregnant persons testing positive for SARS-CoV-2. Efforts to address testing differences between groups could improve equitable testing practices and care for pregnant persons with SARS-CoV-2 infections. |
Comparative neurotranscriptomics reveal widespread species differences associated with bonding.
Tripp JA , Berrio A , McGraw LA , Matz MV , Davis JK , Inoue K , Thomas JW , Young LJ , Phelps SM . BMC Genomics 2021 22 (1) 399 ![]() BACKGROUND: Pair bonding with a reproductive partner is rare among mammals but is an important feature of human social behavior. Decades of research on monogamous prairie voles (Microtus ochrogaster), along with comparative studies using the related non-bonding meadow vole (M. pennsylvanicus), have revealed many of the neural and molecular mechanisms necessary for pair-bond formation in that species. However, these studies have largely focused on just a few neuromodulatory systems. To test the hypothesis that neural gene expression differences underlie differential capacities to bond, we performed RNA-sequencing on tissue from three brain regions important for bonding and other social behaviors across bond-forming prairie voles and non-bonding meadow voles. We examined gene expression in the amygdala, hypothalamus, and combined ventral pallidum/nucleus accumbens in virgins and at three time points after mating to understand species differences in gene expression at baseline, in response to mating, and during bond formation. RESULTS: We first identified species and brain region as the factors most strongly associated with gene expression in our samples. Next, we found gene categories related to cell structure, translation, and metabolism that differed in expression across species in virgins, as well as categories associated with cell structure, synaptic and neuroendocrine signaling, and transcription and translation that varied among the focal regions in our study. Additionally, we identified genes that were differentially expressed across species after mating in each of our regions of interest. These include genes involved in regulating transcription, neuron structure, and synaptic plasticity. Finally, we identified modules of co-regulated genes that were strongly correlated with brain region in both species, and modules that were correlated with post-mating time points in prairie voles but not meadow voles. CONCLUSIONS: These results reinforce the importance of pre-mating differences that confer the ability to form pair bonds in prairie voles but not promiscuous species such as meadow voles. Gene ontology analysis supports the hypothesis that pair-bond formation involves transcriptional regulation, and changes in neuronal structure. Together, our results expand knowledge of the genes involved in the pair bonding process and open new avenues of research in the molecular mechanisms of bond formation. |
Respiratory Viral Infections and Infection Prevention Practices among Women with Acute Respiratory Illness during Delivery Hospitalizations during the 2019-2020 Influenza Season
Dawood FS , Varner M , Munoz F , Stockwell MS , Suyama J , Li DK , Tita A , Mathias L , Shakib JH , Piedra PA , Gyamfi-Bannerman C , Weissman A , Ferber J , Battarbee AN , Wesley MG , Vorwaller K , Powers E , Gibson M , Bond N , Santarcangelo P , Avadhanula V , Newes-Adeyi G , Hunt DR , Subramaniam A , Sanusi A , Boone A , Ogokeh C , Macio I , Odouli R , Thind P , Vargas CY , Almonte C , Galang R , Shapiro-Mendoza C , Campbell AP . J Infect Dis 2021 225 (1) 50-54 We conducted a cross-sectional study of pregnant women with acute respiratory illness during delivery hospitalizations in influenza season to describe clinical testing for respiratory viruses and infection prevention practices. Women had nasal swabs tested for influenza and other respiratory viruses. Among 91 enrolled women, 22 (24%) had clinical testing for influenza. Based on clinical and study testing combined, 41/91 (45%) women had samples positive for respiratory viruses. The most common virus was influenza (17/91, 19%); 53% (9/17) of influenza virus infections were identified through study testing alone. Only 16% of women were on droplet precautions. Peripartum respiratory infections may be underrecognized. |
Characteristics and health status of informal unpaid caregivers - 44 states, District of Columbia, and Puerto Rico, 2015-2017
Edwards VJ , Bouldin ED , Taylor CA , Olivari BS , McGuire LC . MMWR Morb Mortal Wkly Rep 2020 69 (7) 183-188 In 2015, an estimated 17.7 million U.S. persons were informal caregivers who provided substantial services through in-home, unpaid assistance to their family members and friends (1). Caregiving can have many benefits, such as enhancing the bond between caregiver and recipient, but it can also place an emotional and physical strain on caregivers, leading to higher rates of depression, lower quality of life, and poorer overall health (2). As the U.S. population continues to age (3), the need for informal caregivers will likely increase. However, little nationally representative information on prevalence of caregivers is available. This study examined demographic characteristics and health status of informal caregivers from 44 states,* the District of Columbia (DC), and Puerto Rico, based on data from the Behavioral Risk Factor Surveillance System (BRFSS) collected during 2015-2017. Overall, approximately one in five adults reported that they had provided care to a family member or friend in the preceding 30 days. Fifty-eight percent of caregivers were women, and a majority were non-Hispanic white, with at least some college education, and married or living with a partner. Across all states, 19.2% of caregivers reported being in fair or poor health, although significant state-to-state variation occurred. Caregivers provide important support to family members, friends, and the health care system and might compromise their own health to provide this support (1,2). Better understanding of caregivers and the challenges they face could inform implementation of improvements in support systems that could enhance not only the health of the caregiver, but that of the care recipient as well. For example, additional data regarding demographics at the state level might aid in more effective planning and support of caregivers with evidence-based programs and assistance (https://www.cdc.gov/aging/publications/features/caring-for-yourself.html). |
Strengthening quality of tuberculosis laboratories toward accreditation in Viet Nam
Gumma V , Bennett DL , Nguyen Thi Phong L , Duong Ngoc C , Bond KB , Nguyen Thi Hoang Y , Erni D , Nguyen Van N , Nguyen Van H , Albert H . Am J Clin Pathol 2019 152 (6) 808-817 OBJECTIVES: Early diagnosis of tuberculosis (TB) and multidrug-resistant TB (MDR-TB) is a priority for Viet Nam's National TB Control Programme. In many laboratories, quality systems are weak; few have attained accreditation. We implemented a structured training and mentoring program for TB laboratories and measured impact on quality. METHODS: Six TB culture laboratories implemented the Strengthening TB Laboratory Management Towards Accreditation (TB SLMTA) program, consisting of three training workshops and on-site mentoring between workshops to support improvement projects. Periodic audits, using standardized checklists, monitored laboratories' progress toward accreditation readiness. RESULTS: At baseline, all six laboratories achieved a zero-star level. At exit, five laboratories attained three stars and another one star. Overall checklist scores increased by 44.2% on average, from 29.8% to 74.0%; improvements occurred across all quality system essentials. CONCLUSIONS: The program led to improved quality systems. Sites should be monitored to ensure sustainability of improvements and country capacity expanded for national scaleup. |
HIV diagnoses and the HIV care continuum among women and girls aged 13 years - 39 states and the District of Columbia, 2015-2016
Hoover KW , Hu X , Porter SE , Buchacz K , Bond MD , Siddiqi AE , Haynes SG . J Acquir Immune Defic Syndr 2019 81 (3) 251-256 BACKGROUND: In 2017, 19% of new HIV diagnoses in the United States were in women. HIV acquisition can be prevented with preexposure prophylaxis (PrEP), and HIV transmission with viral suppression. HIV viral suppression is achieved by linking women to care and supporting adherence to antiretroviral (ARV) medications. The national HIV prevention goal for viral suppression is 80%. SETTING: United States METHODS: We analyzed data reported by 40 U.S. jurisdictions to the Centers for Disease Control and Prevention's National HIV Surveillance System to determine the number and rate of HIV diagnoses per 100,000 women in 2016. We also determined the percentages of women with diagnosed HIV who were linked to care within 1 and 3 months, received HIV care, were retained in HIV care, and were virally suppressed in 2015. Findings were stratified by demographic characteristics and HIV transmission category. RESULTS: In 2016, 6,407 women were diagnosed with HIV. Black women had a rate of 783.7 per 100,000, Hispanic/Latino women 182.7, and white women 43.6. In 2015, 190,735 women were living with diagnosed HIV. Viral suppression increased with age, ranging from 46.5% among women aged 13-24 years to 62.3% among women aged >/=45 years. Black women had the lowest rate of viral suppression (55.5%). No age group of women achieved 80% viral suppression. CONCLUSION: PrEP implementation for women at high risk for HIV infection can help to decrease new infections. Women living with HIV would benefit from interventions that support linkage to HIV care and ARV medication adherence to increase viral suppression. |
Impact of external quality assurance on the quality of Xpert MTB/RIF testing in Viet Nam
Gumma V , DeGruy K , Bennett D , Kim Thanh N , Albert H , Bond KB , Gutreuter S , Alexander H , Lan Thi Phong N , Rush TH , Viet Nhung N , Hung NV . J Clin Microbiol 2018 57 (3) Following the World Health Organization's (WHO) endorsement of the Xpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) assay in 2010, Viet Nam's National TB Control Programme (NTP) began implementing GeneXpert instruments in NTP laboratories. In 2013, Viet Nam's National Tuberculosis (TB) Programme implemented an Xpert MTB/RIF External Quality Assurance (EQA) programme in collaboration with the United States Centers for Disease Control and Prevention (CDC) and the Foundation for Innovative New Diagnostics (FIND). Proficiency testing (PT) panels comprising five dried tube specimens (DTS) were sent to participating sites approximately twice per annum from October 2013 to July 2016. The number of enrolled laboratories increased from 22 to 39 during the study period. Testing accuracy was assessed by comparing reported and expected results, percentage scores were assigned, and feedback reports were provided to sites. On-site evaluation (OSE) was conducted for under-performing laboratories. Results from the first five rounds demonstrate the positive impact of PT and targeted OSE visits on testing quality. On average, for every additional round of feedback, the odds of achieving PT scores of >/=80% increased 2.04-fold (95% CI 1.39-3.00). Future work will include scale up of PT to all sites and maintaining performance of participating laboratories, while developing local panel production capacity. |
Biomarkers of Nutrition for Development (BOND) - Iron review
Lynch S , Pfeiffer CM , Georgieff MK , Brittenham G , Fairweather-Tait S , Hurrell RF , McArdle HJ , Raiten DJ . J Nutr 2018 148 1001s-1067s This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation. |
Impact of enzymatic hydrolysis on the quantification of total urinary concentrations of chemical biomarkers
Dwivedi P , Zhou X , Powell TG , Calafat AM , Ye X . Chemosphere 2018 199 256-262 Human exposure to consumer and personal care products chemicals such as phenols, including parabens and other antimicrobial agents, can be assessed through biomonitoring by quantifying urinary concentrations of the parent chemical or its metabolites, often after hydrolysis of phase II conjugates. Developing suitable analytical methods for the concurrent quantification of multiple exposure biomarkers is challenging because optimal conditions for the hydrolysis of such conjugates (e.g., O-glucuronides, N-glucuronides, sulfates) may differ depending on the biomarker. We evaluated the effectiveness of seven commercial hydrolytic enzymes to simultaneously hydrolyze N-glucuronides (using the antibacterial triclocarban as example compound) and other conjugates (using select phenols and parabens as examples) by using on-line solid phase extraction-high performance liquid chromatography-isotope dilution-tandem mass spectrometry. Incubation (30min, 55 degrees C) with a genetically engineered beta-glucuronidase (IMCS, >/=15 units/muL urine) hydrolyzed N-glucuronide triclocarban, but did not fully hydrolyze the conjugates of phenols and parabens. By contrast, incubation (4h, 37 degrees C) with solid beta-glucuronidase (Helix pomatia, Type H-1, >/=30 units/muL urine) or liquid beta-glucuronidase/arylsulfatase (Helix pomatia, 30 units/muL urine [i.e., 30 muL/100muL urine]) in the presence of 100muL methanol for 100muL urine completely hydrolyzed N-glucuronide triclocarban and the conjugates of several phenols and parabens, without cleaving the ester bond of the parabens to form p-hydroxybenzoic acid. These results highlight the relevance of method validation procedures that include optimizing the hydrolysis of phase II urinary conjugates (e.g., enzyme type and amount used, reaction time, temperature) to quantify accurately and concurrently multiple exposure biomarkers for biomonitoring purposes. |
Monoclonal antibody that recognizes diethoxyphosphotyrosine-modified proteins and peptides independent of surrounding amino acids
Onder S , Dafferner AJ , Schopfer LM , Xiao G , Yerramalla U , Tacal O , Blake TA , Johnson RC , Lockridge O . Chem Res Toxicol 2017 30 (12) 2218-2228 Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are irreversibly inhibited by organophosphorus pesticides through formation of a covalent bond with the active site serine. Proteins that have no active site serine, for example albumin, are covalently modified on tyrosine and lysine. Chronic illness from pesticide exposure is not explained by inhibition of AChE and BChE. Our goal was to produce a monoclonal antibody that recognizes proteins diethoxyphosphorylated on tyrosine. Diethoxyphosphate-tyrosine adducts for 13 peptides were synthesized. The diethoxyphosphorylated (OP) peptides cross-linked to four different carrier proteins were used to immunize, boost, and screen mice. Monoclonal antibodies were produced with hybridoma technology. Monoclonal antibody depY was purified and characterized by ELISA, western blotting, Biacore, and Octet technology to determine binding affinity and binding specificity. DepY recognized diethoxyphosphotyrosine independent of the amino acid sequence around the modified tyrosine and independent of the identity of the carrier protein or peptide. It had an IC50 of 3 x 10(-9) M in a competition assay with OP tubulin. Kd values measured by Biacore and OctetRED96 were 10(-8) M for OP-peptides and 1 x 10(-12) M for OP-proteins. The limit of detection measured on western blots hybridized with 0.14 mug/mL of depY was 0.025 mug of human albumin conjugated to YGGFL-OP. DepY was specific for diethoxyphosphotyrosine (chlorpyrifos oxon adduct) as it failed to recognize diethoxyphospholysine, phosphoserine, phosphotyrosine, phosphothreonine, dimethoxyphosphotyrosine (dichlorvos adduct), dimethoxyphosphoserine, monomethoxyphosphotyrosine (aged dichlorvos adduct), and cresylphosphoserine. In conclusion, a monoclonal antibody that specifically recognizes diethoxyphosphotyrosine adducts has been developed. The depY monoclonal antibody could be useful for identifying new biomarkers of OP exposure. |
Immunopurification of acetylcholinesterase from red blood cells for detection of nerve agent exposure
Dafferner AJ , Schopfer LM , Xiao G , Cashman JR , Yerramalla U , Johnson RC , Blake TA , Lockridge O . Chem Res Toxicol 2017 30 (10) 1897-1910 Nerve agents and organophosphorus pesticides make a covalent bond with the active site serine of acetylcholinesterase (AChE), resulting in inhibition of AChE activity and toxic symptoms. AChE in red blood cells (RBCs) serves as a surrogate for AChE in the nervous system. Mass spectrometry analysis of adducts on RBC AChE could provide evidence of exposure. Our goal was to develop a method of immunopurifying human RBC AChE in quantities adequate for detecting exposure by mass spectrometry. For this purpose, we immobilized 3 commercially available anti-human acetylcholinesterase monoclonal antibodies (AE-1, AE-2, and HR2) plus 3 new monoclonal antibodies. The monoclonal antibodies were characterized for binding affinity, epitope mapping by pairing analysis, and nucleotide and amino acid sequences. AChE was solubilized from frozen RBCs with 1% (v/v) Triton X-100. A 16 mL sample containing 5.8 mug of RBC AChE was treated with a quantity of soman model compound that inhibited 50% of the AChE activity. Native and soman-inhibited RBC AChE samples were immunopurified on antibody-Sepharose beads. The immunopurified RBC AChE was digested with pepsin and analyzed by liquid chromatography tandem mass spectrometry on a 6600 Triple-TOF mass spectrometer. The aged soman-modified PheGlyGluSerAlaGlyAlaAlaSer (FGESAGAAS) peptide was detected using a targeted analysis method. It was concluded that all 6 monoclonal antibodies could be used to immunopurify RBC AChE and that exposure to nerve agents could be detected as adducts on the active site serine of RBC AChE. |
Further optimization of peptide substrate enhanced assay performance for BoNT/A detection by MALDI-TOF mass spectrometry
Wang D , Baudys J , Hoyt KM , Barr JR , Kalb SR . Anal Bioanal Chem 2017 409 (20) 4779-4786 Rapid and sensitive detection of botulinum neurotoxins (BoNTs), which cause botulism, is essential in a public health emergency or bioterrorism event. We have previously developed a mass spectrometry (MS)-based functional method, Endopep-MS assay, for the fast detection and differentiation of all BoNT serotypes by affinity enriching the toxin and detecting the serotype-specific cleavage products of peptide substrates derived from the in vivo targets. To improve the performance of the Endopep-MS assay, we report here the further optimization of the peptide substrate for the detection of serotype A botulinum neurotoxins. An increased substrate cleavage was achieved by extending the original peptide N-terminus with optimized amino acid sequence, increasing the detection sensitivity of the method. In addition, the resistance of the substrate to nonspecific hydrolysis was dramatically improved by selectively substituting amino acids at the scissile bond and various other positions of the extended peptide. Moreover, incorporating the N-terminal hydrophobic residues dramatically improved the relative intensity of the cleavage products in the mass spectra. This allowed easy detection of the cleavage products, further enhancing the performance of the assay. The limit of detection for spiked serum sample was enhanced from 0.5 to 0.1 mouseLD50 and from 0.5 to 0.2 mouseLD50 for spiked stool. Graphical abstract Mass spectra of optimized and old peptide substrates with BoNT/A. |
Rapid ascent from zero quality to international organization for standardization accreditation : A case study of Hai Duong Preventive Medicine Center in Vietnam, 2012-2013
Duong CN , Bond KB , Carvalho H , Thi Thu HB , Nguyen T , Rush T . Am J Clin Pathol 2017 147 (4) 427-431 Objectives: In 2012, the Vietnam Ministry of Health sought to improve the quality of health laboratories by introducing international quality standards. Methods: Strengthening Laboratory Management Toward Accreditation (SLMTA), a year-long, structured, quality improvement curriculum (including projects and mentorship) was piloted in 12 laboratories. Progress was measured using a standardized audit tool (Stepwise Laboratory Quality Improvement Process Towards Accreditation). Results: All 12 pilot laboratories (a mix of hospital and public health) demonstrated improvement; median scores rose from 44% to 78% compliance. The public health laboratory in Hai Duong Province entered the program with the lowest score of the group (28%) yet concluded with the highest score (86%). Five months after the completion of the program, without any additional external support, they were accredited. Laboratory management/staff describe factors key to their success: support from the facility senior management, how-to guidance provided by SLMTA, support from the site mentor, and strong commitment of laboratory staff. Conclusions: Hai Duong preventive medical center is one of only a handful of laboratories to reach accreditation after participation in SLMTA and the only laboratory to do so without additional support. Due to the success seen in Hai Duong and other pilot laboratories, Vietnam has expanded the use of SLMTA. |
Incorporating One Health into medical education
Rabinowitz PM , Natterson-Horowitz BJ , Kahn LH , Kock R , Pappaioanou M . BMC Med Educ 2017 17 (1) 45 One Health is an emerging concept that stresses the linkages between human, animal, and environmental health, as well as the need for interdisciplinary communication and collaboration to address health issues including emerging zoonotic diseases, climate change impacts, and the human-animal bond. It promotes complex problem solving using a systems framework that considers interactions between humans, animals, and their shared environment. While many medical educators may not yet be familiar with the concept, the One Health approach has been endorsed by a number of major medical and public health organizations and is beginning to be implemented in a number of medical schools. In the research setting, One Health opens up new avenues to understand, detect, and prevent emerging infectious diseases, and also to conduct translational studies across species. In the clinical setting, One Health provides practical ways to incorporate environmental and animal contact considerations into patient care. This paper reviews clinical and research aspects of the One Health approach through an illustrative case updating the biopsychosocial model and proposes a basic set of One Health competencies for training and education of human health care providers. |
A high-throughput UHPLC-MS/MS method for the quantification of five aged butyrylcholinesterase biomarkers from human exposure to organophosphorus nerve agents
Graham LA , Johnson D , Carter MD , Stout EG , Erol HA , Isenberg SL , Mathews TP , Thomas JD , Johnson RC . Biomed Chromatogr 2016 31 (4) Organophosphorus nerve agents (OPNAs) are toxic compounds that are classified as prohibited Schedule 1 chemical weapons. In the body, OPNAs bind to butyrylcholinesterase (BChE) to form nerve agent adducts (OPNA-BChE). OPNA-BChE adducts can provide a reliable, long-term protein biomarker for assessing human exposure. A major challenge facing OPNA-BChE detection is hydrolysis (aging), which can continue to occur after a clinical specimen has been collected. During aging, the o-alkyl phosphoester bond hydrolyzes, and the specific identity of the nerve agent is lost. To better identify OPNA exposure events, a high throughput method for the detection of five aged OPNA-BChE adducts was developed. This is the first diagnostic panel to allow for the simultaneous quantification of any Chemical Weapons Convention Schedule 1 OPNA by measuring the aged adducts methyl phosphonate (MeP-BChE), ethyl phosphonate (EtP-BChE), propyl phosphonate (PrP-BChE), ethyl phosphoryl (ExP-BChE), phosphoryl (P-BChE), and unadducted BChE. The calibration range for all analytes is 2.00 - 250. ng/mL, which is consistent with similar methodologies used to detect unaged OPNA-BChE adducts. Each analytical run is three minutes making the time to first unknown results, including calibration curve and quality controls, less than one hour. Analysis of commercially purchased individual serum samples demonstrated no potential interferences with detection of aged OPNA-BChE adducts, and quantitative measurements of endogenous levels of BChE were similar to those previously reported in other OPNA-BChE adduct assays. |
Open-source LIMS in Vietnam: the path toward sustainability and host country ownership
Landgraf KM , Kakkar R , Meigs M , Jankauskas PT , Phan TT , Nguyen VN , Nguyen DT , Duong TT , Nguyen TH , Bond KB . Int J Med Inform 2016 93 92-102 OBJECTIVE: The objectives of this case report are as follows: to describe the process of establishing a national laboratory information management system (LIMS) program for clinical and public health laboratories in Vietnam; to evaluate the outcomes and lessons learned; and to present a model for sustainability based on the program outcomes that could be applied to diverse laboratory programs. METHODS: This case report comprises a review of program documentation and records, including planning and budgetary records of the donor, monthly reports from the implementer, direct observation, and ad-hoc field reports from technical advisors and governmental agencies. Additional data on program efficacy and user acceptance were collected from routine monitoring of laboratory policies and operational practices. RESULTS: LIMS software was implemented at 38 hospital, public health and HIV testing laboratories in Vietnam. This LIMS was accepted by users and program managers as a useful tool to support laboratory processes. Implementation cost per laboratory and average duration of deployment decreased over time, and project stakeholders initiated transition of financing (from the donor to local institutions) and of system maintenance functions (from the implementer to governmental and site-level staff). Collaboration between the implementer in Vietnam and the global LIMS user community was strongly established, and knowledge was successfully transferred to staff within Vietnam. CONCLUSION: Implementing open-sourced LIMS with local development and support was a feasible approach towards establishing a sustainable laboratory informatics program that met the needs of health laboratories in Vietnam. Further effort to institutionalize IT support capacity within key government agencies is ongoing. |
Biomarkers of nutrition for development - folate review
Bailey LB , Stover PJ , McNulty H , Fenech MF , Gregory JF 3rd , Mills JL , Pfeiffer CM , Fazili Z , Zhang M , Ueland PM , Molloy AM , Caudill MA , Shane B , Berry RJ , Bailey RL , Hausman DB , Raghavan R , Raiten DJ . J Nutr 2015 145 (7) 1636S-80S The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-based advice to anyone with an interest in the role of nutrition in health. Specifically, the BOND program provides state-of-the-art information and service with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutrients in body tissues at the individual and population level. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, iron, zinc, folate, vitamin A, and vitamin B-12. This review represents the second in the series of reviews and covers all relevant aspects of folate biology and biomarkers. The article is organized to provide the reader with a full appreciation of folate's history as a public health issue, its biology, and an overview of available biomarkers (serum folate, RBC folate, and plasma homocysteine concentrations) and their interpretation across a range of clinical and population-based uses. The article also includes a list of priority research needs for advancing the area of folate biomarkers related to nutritional health status and development. |
Evaluation of nine HIV rapid test kits to develop a national HIV testing algorithm in Nigeria
Bassey O , Bond K , Adedeji A , Oke O , Abubakar A , Yakubu K , Jelpe T , Akintunde E , Ikani P , Ogundiran A , Onoja A , Kawu I , Ikwulono G , Saliu I , Nwanyawu O , Deyde V . Afr J Lab Med 2015 4 (1) BACKGROUND: Non-cold chain-dependent HIV rapid testing has been adopted in many resource-constrained nations as a strategy for reaching out to populations. HIV rapid test kits (RTKs) have the advantage of ease of use, low operational cost and short turnaround times. Before 2005, different RTKs had been used in Nigeria without formal evaluation. Between 2005 and 2007, a study was conducted to formally evaluate a number of RTKs and construct HIV testing algorithms. OBJECTIVES: The objectives of this study were to assess and select HIV RTKs and develop national testing algorithms. METHOD: Nine RTKs were evaluated using 528 well-characterised plasma samples. These comprised 198 HIV-positive specimens (37.5%) and 330 HIV-negative specimens (62.5%), collected nationally. Sensitivity and specificity were calculated with 95% confidence intervals for all nine RTKs singly and for serial and parallel combinations of six RTKs; and relative costs were estimated. RESULTS: Six of the nine RTKs met the selection criteria, including minimum sensitivity and specificity (both > 99.0%) requirements. There were no significant differences in sensitivities or specificities of RTKs in the serial and parallel algorithms, but the cost of RTKs in parallel algorithms was twice that in serial algorithms. Consequently, three serial algorithms, comprising four test kits (BundiTM, DetermineTM, Stat-Pak and Uni-GoldTM) with 100.0% sensitivity and 99.1% - 100.0% specificity, were recommended and adopted as national interim testing algorithms in 2007. CONCLUSION: This evaluation provides the first evidence for reliable combinations of RTKs for HIV testing in Nigeria. However, these RTKs need further evaluation in the field (Phase II) to re-validate their performance. |
Assessing the sources of Asian versus non-Asian disparities in delinquency
Feldmeyer B , Cui W . J Ethn Crim Justice 2015 13 (1) 30-58 Research on race/ethnicity and crime has often overlooked the patterns and predictors of Asian American offending, particularly compared to those of other racial/ethnic groups. The current study addresses this gap in the research using data from the National Longitudinal Study of Adolescent Health to assess the degree to which social factors drawn from criminological theories are able to account for Asian versus non-Asian (White, Black, Latino, and Native American) levels of delinquency. This analysis also extends prior work by exploring the sources of these disparities in delinquency using (a) multiple offense types (violent, property, and drug offending), (b) multiple theoretical approaches (social bond, anomie/strain, and social learning perspectives), and (c) measures that capture the frequency and intensity of serious delinquency for a nationally representative sample of youth. Findings indicate that Asian American youth report lower levels of violence and drug use than other racial/ethnic groups, which are explained by a combination of protective factors, including lower levels of strain, strong bonds to school, and less exposure to delinquent peers. |
SLIPTA e-tool improves laboratory audit process in Vietnam and Cambodia
Nguyen TT , McKinney B , Pierson A , Luong KN , Hoang QT , Meharwal S , Carvalho HM , Nguyen CQ , Nguyen KT , Bond KB . Afr J Lab Med 2014 3 (2) 219 BACKGROUND: The Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) checklist is used worldwide to drive quality improvement in laboratories in developing countries and to assess the effectiveness of interventions such as the Strengthening Laboratory Management Toward Accreditation (SLMTA) programme. However, the paperbased format of the checklist makes administration cumbersome and limits timely analysis and communication of results. Development of e-Tool: In early 2012, the SLMTA team in Vietnam developed an electronic SLIPTA checklist tool. The e-Tool was pilot tested in Vietnam in mid-2012 and revised. It was used during SLMTA implementation in Vietnam and Cambodia in 2012 and 2013 and further revised based on auditors' feedback about usability. OUTCOMES: The SLIPTA e-Tool enabled rapid turn-around of audit results, reduced workload and language barriers and facilitated analysis of national results. Benefits of the e-Tool will be magnified with in-country scale-up of laboratory quality improvement efforts and potential expansion to other countries. |
Biomarkers of nutrition for development - iodine review
Rohner F , Zimmermann M , Jooste P , Pandav C , Caldwell K , Raghavan R , Raiten DJ . J Nutr 2014 144 (8) 1322S-1342S The objective of the Biomarkers of Nutrition for Development (BOND) project is to provide state-of-the-art information and service with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect. Specifically, the BOND project seeks to develop consensus on accurate assessment methodologies that are applicable to researchers (laboratory/clinical/surveillance), clinicians, programmers, and policy makers (data consumers). The BOND project is also intended to develop targeted research agendas to support the discovery and development of biomarkers through improved understanding of nutrient biology within relevant biologic systems. In phase I of the BOND project, 6 nutrients (iodine, vitamin A, iron, zinc, folate, and vitamin B-12) were selected for their high public health importance because they typify the challenges faced by users in the selection, use, and interpretation of biomarkers. For each nutrient, an expert panel was constituted and charged with the development of a comprehensive review covering the respective nutrient's biology, existing biomarkers, and specific issues of use with particular reference to the needs of the individual user groups. In addition to the publication of these reviews, materials from each will be extracted to support the BOND interactive Web site (http://www.nichd.nih.gov/global_nutrition/programs/bond/pages/index.aspx). This review represents the first in the series of reviews and covers all relevant aspects of iodine biology and biomarkers. The article is organized to provide the reader with a full appreciation of iodine's background history as a public health issue, its biology, and an overview of available biomarkers and specific considerations for the use and interpretation of iodine biomarkers across a range of clinical and population-based uses. The review also includes a detailed research agenda to address priority gaps in our understanding of iodine biology and assessment. |
Strengthening global health security capacity - Vietnam demonstration project, 2013
Tran PD , Vu LN , Nguyen HT , Phan LT , Lowe W , McConnell MS , Iademarco MF , Partridge JM , Kile JC , Do T , Nadol PJ , Bui H , Vu D , Bond K , Nelson DB , Anderson L , Hunt KV , Smith N , Giannone P , Klena J , Beauvais D , Becknell K , Tappero JW , Dowell SF , Rzeszotarski P , Chu M , Kinkade C . MMWR Morb Mortal Wkly Rep 2014 63 (4) 77-80 Over the past decade, Vietnam has successfully responded to global health security (GHS) challenges, including domestic elimination of severe acute respiratory syndrome (SARS) and rapid public health responses to human infections with influenza A(H5N1) virus. However, new threats such as Middle East respiratory syndrome coronavirus (MERS-CoV) and influenza A(H7N9) present continued challenges, reinforcing the need to improve the global capacity to prevent, detect, and respond to public health threats. In June 2012, Vietnam, along with many other nations, obtained a 2-year extension for meeting core surveillance and response requirements of the 2005 International Health Regulations (IHR). During March-September 2013, CDC and the Vietnamese Ministry of Health (MoH) collaborated on a GHS demonstration project to improve public health emergency detection and response capacity. The project aimed to demonstrate, in a short period, that enhancements to Vietnam's health system in surveillance and early detection of and response to diseases and outbreaks could contribute to meeting the IHR core capacities, consistent with the Asia Pacific Strategy for Emerging Diseases. Work focused on enhancements to three interrelated priority areas and included achievements in 1) establishing an emergency operations center (EOC) at the General Department of Preventive Medicine with training of personnel for public health emergency management; 2) improving the nationwide laboratory system, including enhanced testing capability for several priority pathogens (i.e., those in Vietnam most likely to contribute to public health emergencies of international concern); and 3) creating an emergency response information systems platform, including a demonstration of real-time reporting capability. Lessons learned included awareness that integrated functions within the health system for GHS require careful planning, stakeholder buy-in, and intradepartmental and interdepartmental coordination and communication. |
Direct quantitation of methyl phosphonate adducts to human serum butyrylcholinesterase by immunomagnetic-UHPLC-MS/MS
Carter MD , Crow BS , Pantazides BG , Watson CM , Thomas JD , Blake TA , Johnson RC . Anal Chem 2013 85 (22) 11106-11 Hydrolysis of G- and V-series organophosphorus nerve agents (OPNAs) containing a phosphorus-methyl bond yields a methylphosphonic acid (MeP) product when adducted to human butyrylcholinesterase (BChE). The MeP adduct is considered a sign of "aging" and results in loss of the o-alkyl identifier specific to each nerve agent. After aging has occurred, common therapeutics such as oximes cannot reactivate the cholinesterase enzyme and relieve cholinergic inhibition. Until now, a direct, quantitative method for determination of the MeP adduct to BChE was unavailable. Aged adducts in serum samples were processed by immunomagnetic separation of BChE by antibody conjugated bead, isotope-dilution, pepsin digestion, followed by UHPLC separation and detection by conventional electrospray ionization-tandem mass spectrometry (ESI-MS/MS). Ions were detected in selected reaction monitoring (SRM) mode, and transition m/z 874.3 → 778.3 was used for quantitation. The analytical response ratio was linearly proportional to the serum concentration of MeP-adducted peptide (MeP-P) over the nominal concentration range of 2.0-250 ng/mL, with a coefficient of determination of R(2) ≥ 0.997. Intrarun accuracy, expressed as %Relative Error (%RE), was ≤13.5%, 16.3%, and 3.20% at 2.0, 16, and 250 ng/mL, respectively; the corresponding precision expressed as %RSD was ≤11.9%, 6.15%, and 3.39%. Interday %RSD was ≤7.13%, 5.69%, and 1.91%. Recovery of MeP-P from serum was ≥68% across the validated concentration range, and contributions from matrix effects were minimal. The method provides a direct, quantitative measurement of MeP-P found in clinical samples suspected of nerve agent exposure and subjected to such post-sampling stresses as elevated temperature and extended shipping. |
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