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Behavioural mental health interventions delivered in the emergency department for suicide, overdose and psychosis: a scoping review. BMJ Open 2024; 14:e080023. [PMID: 38531581 DOI: 10.1136/bmjopen-2023-080023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/28/2024] Open
Abstract
OBJECTIVE To identify and describe evidence on brief emergency department (ED)-delivered behavioural and care process interventions among patients presenting with suicide attempt or acute ideation, substance overdose or psychosis. DESIGN We employed a scoping review design and searched multiple data sources, clinical trial registries and references lists through March 2023. We included English-language trials and rigorously designed observational studies. In alignment with scoping review guidelines, we did not assess the quality of included studies or rate the strength of evidence of intervention effectiveness. POPULATION Our population of interest was adults presenting to the ED with suicidality (eg, attempt or acute ideation), any substance overdose or acute psychosis from a primary mental health condition. INTERVENTION We included studies of brief behavioural or care process interventions delivered in the ED. OUTCOME MEASURES Health outcomes (eg, symptom reduction), healthcare utilisation and harms. RESULTS Our search identified 2034 potentially relevant articles. We included 40 studies: 3 systematic reviews and 39 primary studies. Most studies (n=34) examined ED interventions in patients with suicide attempt or suicidal ideation, while eight studies examined interventions in patients with opioid overdose. No studies examined ED interventions in patients with acute psychosis. Most suicide prevention studies reported that brief psychological, psychosocial or screening and triage interventions reduce suicide and suicide attempt following an ED visit. Most clinical trial interventions were multicomponent and included at least one follow-up. All substance overdose studies focused on opioids. These studies often contained medication and referral or consultation components. Multiple studies reported increases in substance use disorder treatment utilisation; evidence on repeat overdose events was limited. CONCLUSIONS A wide range of multicomponent ED-delivered behavioural health interventions for suicidality and opioid use disorder show short-term improvement on primary outcomes such as suicide reattempt. Few studies on non-opioid substances and psychosis are available.
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A scoping review of the structuring of questions about sexual orientation and gender identity. JOURNAL OF COMMUNITY PSYCHOLOGY 2023; 51:2592-2617. [PMID: 37088990 DOI: 10.1002/jcop.23048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 05/03/2023]
Abstract
The purpose of this scoping review is to map the extent of the current research on how to best structure questions asking respondents to self-identify their sexual orientation and gender identity and to ascertain what further issues about measurement need to be explored. Using the Arksey and O'Malley framework for scoping reviews, 52 articles describing primary research about how to structure sexual orientation and gender identity (SOGI) questions, published in the years 2000-2021, were identified and analyzed. The domain of sexuality being asked about (e.g., self-label vs. behavior) needs to be clarified, and gender identity should be asked through a multipart item differentiating current identity from the sex assigned at birth. The terms used in the response options should be defined and may vary based on the study population or context. Contrary to expectations given the wide range of question formats currently being used in the field, there is considerable consensus around the basic tenets for structuring questions designed to assess SOGI dimensions.
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Inter-species geographic signatures for tracing horizontal gene transfer and long-term persistence of carbapenem resistance. Genome Med 2022; 14:37. [PMID: 35379360 PMCID: PMC8981930 DOI: 10.1186/s13073-022-01040-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/22/2022] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Carbapenem-resistant Enterobacterales (CRE) are an urgent global health threat. Inferring the dynamics of local CRE dissemination is currently limited by our inability to confidently trace the spread of resistance determinants to unrelated bacterial hosts. Whole-genome sequence comparison is useful for identifying CRE clonal transmission and outbreaks, but high-frequency horizontal gene transfer (HGT) of carbapenem resistance genes and subsequent genome rearrangement complicate tracing the local persistence and mobilization of these genes across organisms. METHODS To overcome this limitation, we developed a new approach to identify recent HGT of large, near-identical plasmid segments across species boundaries, which also allowed us to overcome technical challenges with genome assembly. We applied this to complete and near-complete genome assemblies to examine the local spread of CRE in a systematic, prospective collection of all CRE, as well as time- and species-matched carbapenem-susceptible Enterobacterales, isolated from patients from four US hospitals over nearly 5 years. RESULTS Our CRE collection comprised a diverse range of species, lineages, and carbapenem resistance mechanisms, many of which were encoded on a variety of promiscuous plasmid types. We found and quantified rearrangement, persistence, and repeated transfer of plasmid segments, including those harboring carbapenemases, between organisms over multiple years. Some plasmid segments were found to be strongly associated with specific locales, thus representing geographic signatures that make it possible to trace recent and localized HGT events. Functional analysis of these signatures revealed genes commonly found in plasmids of nosocomial pathogens, such as functions required for plasmid retention and spread, as well survival against a variety of antibiotic and antiseptics common to the hospital environment. CONCLUSIONS Collectively, the framework we developed provides a clearer, high-resolution picture of the epidemiology of antibiotic resistance importation, spread, and persistence in patients and healthcare networks.
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Clinical outcomes and cost analysis of one- versus two-stage bilateral hip arthroplasty. A retrospective study of a single surgeon experience. JOURNAL OF ORTHOPAEDICS, TRAUMA AND REHABILITATION 2020. [DOI: 10.1177/2210491720971837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Purpose: One in 10 patients presenting for total hip arthroplasty (THA) will have significant osteoarthritis in both hips. In appropriately selected individuals, one-stage bilateral THA is a treatment option. This study aims to compare outcomes of one-stage bilateral THA with two-stage procedure. Methods: A retrospective review of a single surgeon series was conducted comparing One-stage bilateral THA (n = 59) with two-stage bilateral THA (n = 50). The primary outcomes were post-operative complication and the Oxford Hip Score. The secondary outcome was a financial analysis. Results: Complications were infrequent and comparable between both groups. Oxford hip scores were slightly higher in the one-stage group. One-staged bilateral THA had a lower cost but hospital tariff is higher for two-stage bilateral THA. Conclusion: In appropriately selected patients with bilateral hip arthritis, one-stage bilateral THA gives good clinical outcomes. However, the current payment system in the NHS makes two-stage bilateral THA more financially viable to the hospital.
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COVID-19 and telepsychiatry: Early outpatient experiences and implications for the future. Gen Hosp Psychiatry 2020; 66:89-95. [PMID: 32750604 PMCID: PMC7347331 DOI: 10.1016/j.genhosppsych.2020.07.002] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/30/2020] [Accepted: 07/05/2020] [Indexed: 02/04/2023]
Abstract
The COVID-19 pandemic has dramatically transformed the U.S. healthcare landscape. Within psychiatry, a sudden relaxing of insurance and regulatory barriers during the month of March 2020 enabled clinicians practicing in a wide range of settings to quickly adopt virtual care in order to provide critical ongoing mental health supports to both existing and new patients struggling with the pandemic's impact. In this article, we briefly review the extensive literature supporting the effectiveness of telepsychiatry relative to in-person mental health care, and describe how payment and regulatory challenges were the primary barriers preventing more widespread adoption of this treatment modality prior to COVID-19. We then review key changes that were implemented at the federal, state, professional, and insurance levels over a one-month period that helped usher in an unprecedented transformation in psychiatric care delivery, from mostly in-person to mostly virtual. Early quality improvement data regarding virtual visit volumes and clinical insights from our outpatient psychiatry department located within a large, urban, tertiary care academic medical center reflect both the opportunities and challenges of virtual care for patients and providers. Notable benefits have included robust clinical volumes despite social distancing mandates, reduced logistical barrieres to care for many patients, and decreased no-show rates. Finally, we provide clinical suggestions for optimizing telepsychiatry based on our experience, make a call for advocacy to continue the reduced insurance and regulatory restrictions affecting telepsychiatry even once this public health crisis has passed, and pose research questions that can help guide optimal utilization of telepsychiatry as mainstay or adjunct of outpatient psychiatric treatment now and in the future.
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Transmission of human-associated microbiota along family and social networks. Nat Microbiol 2019; 4:964-971. [PMID: 30911128 DOI: 10.1038/s41564-019-0409-6] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 02/14/2019] [Indexed: 01/01/2023]
Abstract
The human microbiome, described as an accessory organ because of the crucial functions it provides, is composed of species that are uniquely found in humans1,2. Yet, surprisingly little is known about the impact of routine interpersonal contacts in shaping microbiome composition. In a relatively 'closed' cohort of 287 people from the Fiji Islands, where common barriers to bacterial transmission are absent, we examine putative bacterial transmission in individuals' gut and oral microbiomes using strain-level data from both core single-nucleotide polymorphisms and flexible genomic regions. We find a weak signal of transmission, defined by the inferred sharing of genotypes, across many organisms that, in aggregate, reveals strong transmission patterns, most notably within households and between spouses. We were unable to determine the directionality of transmission nor whether it was direct. We further find that women harbour strains more closely related to those harboured by their familial and social contacts than men, and that transmission patterns of oral-associated and gut-associated microbiota need not be the same. Using strain-level data alone, we are able to confidently predict a subset of spouses, highlighting the role of shared susceptibilities, behaviours or social interactions that distinguish specific links in the social network.
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The clinical relevance of sound changes produced during cementless hip arthroplasty: a correctly sized femoral broach creates a distinctive pattern of audio frequencies directly related to bone geometry. Bone Joint J 2018; 100-B:1559-1564. [PMID: 30499313 DOI: 10.1302/0301-620x.100b12.bjj-2018-0368.r2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AIMS Cementless femoral stems must be correctly sized and well-seated to obtain satisfactory biological fixation. The change in sound that occurs during impaction of the femoral broach is said to indicate good fit, but this has not been widely studied. We set out to find whether the presence or absence of these sound changes could predict correct sizing. PATIENTS AND METHODS We recorded the sound generated during femoral broaching for 105 cementless total hip arthroplasties using the Corail stem. Four cases were excluded, leaving 101 recordings for analysis. There were 36 male patients and 65 female patients, with a mean age of 69.9 years (sd 12.3) and median body mass index (BMI) of 29 kg/m 2 (interquartile range (IQR) 26 to 32). The recordings were analyzed to identify the frequencies of the sounds produced during impaction of the femoral broach. RESULTS The emergence of a low-frequency band of sound in the 1 kHz range, during the final femoral broaching, was a strong predictor of a well-sized implant stem. The frequency was related to femoral length, supporting our hypothesis that the sound arose from the bone itself. CONCLUSION The low-frequency sound generated during femoral broaching can be monitored spectrographically, its frequency can be predicted from femoral length, and it is a good predictor of appropriate stem sizing.
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First Searches for Axions and Axionlike Particles with the LUX Experiment. PHYSICAL REVIEW LETTERS 2017; 118:261301. [PMID: 28707937 DOI: 10.1103/physrevlett.118.261301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Indexed: 06/07/2023]
Abstract
The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons g_{Ae} is tested using data collected in 2013 with an exposure totaling 95 live days ×118 kg. A double-sided, profile likelihood ratio statistic test excludes g_{Ae} larger than 3.5×10^{-12} (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV/c^{2}, while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6 eV/c^{2} are excluded. For galactic axionlike particles, values of g_{Ae} larger than 4.2×10^{-13} are excluded for particle masses in the range 1-16 keV/c^{2}. These are the most stringent constraints to date for these interactions.
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Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure. PHYSICAL REVIEW LETTERS 2017; 118:251302. [PMID: 28696768 DOI: 10.1103/physrevlett.118.251302] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 06/07/2023]
Abstract
We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=1.6×10^{-41} cm^{2} (σ_{p}=5×10^{-40} cm^{2}) at 35 GeV c^{-2}, almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.
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Results from a Search for Dark Matter in the Complete LUX Exposure. PHYSICAL REVIEW LETTERS 2017; 118:021303. [PMID: 28128598 DOI: 10.1103/physrevlett.118.021303] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Indexed: 06/06/2023]
Abstract
We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4} kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46} cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46} cm^{2} at 50 GeV c^{-2}.
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Structure of the germline genome of Tetrahymena thermophila and relationship to the massively rearranged somatic genome. eLife 2016; 5. [PMID: 27892853 PMCID: PMC5182062 DOI: 10.7554/elife.19090] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 11/14/2016] [Indexed: 12/30/2022] Open
Abstract
The germline genome of the binucleated ciliate Tetrahymena thermophila undergoes programmed chromosome breakage and massive DNA elimination to generate the somatic genome. Here, we present a complete sequence assembly of the germline genome and analyze multiple features of its structure and its relationship to the somatic genome, shedding light on the mechanisms of genome rearrangement as well as the evolutionary history of this remarkable germline/soma differentiation. Our results strengthen the notion that a complex, dynamic, and ongoing interplay between mobile DNA elements and the host genome have shaped Tetrahymena chromosome structure, locally and globally. Non-standard outcomes of rearrangement events, including the generation of short-lived somatic chromosomes and excision of DNA interrupting protein-coding regions, may represent novel forms of developmental gene regulation. We also compare Tetrahymena's germline/soma differentiation to that of other characterized ciliates, illustrating the wide diversity of adaptations that have occurred within this phylum.
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Erratum to: Comparative genomics and transcriptomics of Pichia pastoris. BMC Genomics 2016; 17:762. [PMID: 27681084 PMCID: PMC5039785 DOI: 10.1186/s12864-016-3109-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 09/21/2016] [Indexed: 11/29/2022] Open
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Abstract
Background Pichia pastoris has emerged as an important alternative host for producing recombinant biopharmaceuticals, owing to its high cultivation density, low host cell protein burden, and the development of strains with humanized glycosylation. Despite its demonstrated utility, relatively little strain engineering has been performed to improve Pichia, due in part to the limited number and inconsistent frameworks of reported genomes and transcriptomes. Furthermore, the co-mingling of genomic, transcriptomic and fermentation data collected about Komagataella pastoris and Komagataella phaffii, the two strains co-branded as Pichia, has generated confusion about host performance for these genetically distinct species. Generation of comparative high-quality genomes and transcriptomes will enable meaningful comparisons between the organisms, and potentially inform distinct biotechnological utilies for each species. Results Here, we present a comprehensive and standardized comparative analysis of the genomic features of the three most commonly used strains comprising the tradename Pichia: K. pastoris wild-type, K. phaffii wild-type, and K. phaffii GS115. We used a combination of long-read (PacBio) and short-read (Illumina) sequencing technologies to achieve over 1000X coverage of each genome. Construction of individual genomes was then performed using as few as seven individual contigs to create gap-free assemblies. We found substantial syntenic rearrangements between the species and characterized a linear plasmid present in K. phaffii. Comparative analyses between K. phaffii genomes enabled the characterization of the mutational landscape of the GS115 strain. We identified and examined 35 non-synonomous coding mutations present in GS115, many of which are likely to impact strain performance. Additionally, we investigated transcriptomic profiles of gene expression for both species during cultivation on various carbon sources. We observed that the most highly transcribed genes in both organisms were consistently highly expressed in all three carbon sources examined. We also observed selective expression of certain genes in each carbon source, including many sequences not previously reported as promoters for expression of heterologous proteins in yeasts. Conclusions Our studies establish a foundation for understanding critical relationships between genome structure, cultivation conditions and gene expression. The resources we report here will inform and facilitate rational, organism-wide strain engineering for improved utility as a host for protein production. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2876-y) contains supplementary material, which is available to authorized users.
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Trends in health care utilization and costs attributable to hepatocellular carcinoma, 2002-2009: a population-based cohort study. ACTA ACUST UNITED AC 2016; 23:e196-220. [PMID: 27330357 DOI: 10.3747/co.23.2956] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND The incidence of hepatocellular carcinoma (hcc) and the complexity of its diagnosis and treatment are increasing. We estimated trends in net health care utilization, costs of care attributable to hcc in Ontario, and rate ratios of resource use at various stages of care. METHODS This population-based retrospective cohort study identified hcc patients and non-cancer control subjects, and health care resource utilization between 2002 and 2009. Generalized estimating equations were then used to estimate net health care utilization (hcc patients vs. the matched control subjects) and net costs of care attributable to hcc. Generalized linear models were used to analyze rate ratios of resource use. RESULTS We identified 2832 hcc patients and 2808 matched control subjects. In comparison with the control subjects, hcc patients generally used a greater number of health care services. Overall, the mean net cost of care per 30 patient-days (2013 Canadian dollars) attributable to outpatient visits and hospitalizations was highest in the pre-diagnosis (1 year before diagnosis), initial (1st year after diagnosis), and end-of-life (last 6 months before death, short-term survivors) phases. Mean net homecare costs were highest in the end-of-life phase (long-term survivors). In the end-of-life phase (short-term survivors), mean net costs attributable to outpatient visits and total services significantly increased to $14,220 from $1,547 and to $33,121 from $14,450 (2008-2009 and 2002-2003 respectively). CONCLUSIONS In hcc, our study found increasing resource use and net costs of care, particularly in the end-of-life phase among short-term survivors. Our findings offer a basis for resource allocation decisions in the area of cancer prevention and control.
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Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment. PHYSICAL REVIEW LETTERS 2016; 116:161302. [PMID: 27152786 DOI: 10.1103/physrevlett.116.161302] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Indexed: 06/05/2023]
Abstract
We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4×10^{4} kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=9.4×10^{-41} cm^{2} (σ_{p}=2.9×10^{-39} cm^{2}) at 33 GeV/c^{2}. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.
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Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data. PHYSICAL REVIEW LETTERS 2016; 116:161301. [PMID: 27152785 DOI: 10.1103/physrevlett.116.161301] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Indexed: 06/05/2023]
Abstract
We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4} kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c^{-2} WIMP mass.
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Evolution of Extensively Drug-Resistant Tuberculosis over Four Decades: Whole Genome Sequencing and Dating Analysis of Mycobacterium tuberculosis Isolates from KwaZulu-Natal. PLoS Med 2015; 12:e1001880. [PMID: 26418737 PMCID: PMC4587932 DOI: 10.1371/journal.pmed.1001880] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 08/20/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The continued advance of antibiotic resistance threatens the treatment and control of many infectious diseases. This is exemplified by the largest global outbreak of extensively drug-resistant (XDR) tuberculosis (TB) identified in Tugela Ferry, KwaZulu-Natal, South Africa, in 2005 that continues today. It is unclear whether the emergence of XDR-TB in KwaZulu-Natal was due to recent inadequacies in TB control in conjunction with HIV or other factors. Understanding the origins of drug resistance in this fatal outbreak of XDR will inform the control and prevention of drug-resistant TB in other settings. In this study, we used whole genome sequencing and dating analysis to determine if XDR-TB had emerged recently or had ancient antecedents. METHODS AND FINDINGS We performed whole genome sequencing and drug susceptibility testing on 337 clinical isolates of Mycobacterium tuberculosis collected in KwaZulu-Natal from 2008 to 2013, in addition to three historical isolates, collected from patients in the same province and including an isolate from the 2005 Tugela Ferry XDR outbreak, a multidrug-resistant (MDR) isolate from 1994, and a pansusceptible isolate from 1995. We utilized an array of whole genome comparative techniques to assess the relatedness among strains, to establish the order of acquisition of drug resistance mutations, including the timing of acquisitions leading to XDR-TB in the LAM4 spoligotype, and to calculate the number of independent evolutionary emergences of MDR and XDR. Our sequencing and analysis revealed a 50-member clone of XDR M. tuberculosis that was highly related to the Tugela Ferry XDR outbreak strain. We estimated that mutations conferring isoniazid and streptomycin resistance in this clone were acquired 50 y prior to the Tugela Ferry outbreak (katG S315T [isoniazid]; gidB 130 bp deletion [streptomycin]; 1957 [95% highest posterior density (HPD): 1937-1971]), with the subsequent emergence of MDR and XDR occurring 20 y (rpoB L452P [rifampicin]; pncA 1 bp insertion [pyrazinamide]; 1984 [95% HPD: 1974-1992]) and 10 y (rpoB D435G [rifampicin]; rrs 1400 [kanamycin]; gyrA A90V [ofloxacin]; 1995 [95% HPD: 1988-1999]) prior to the outbreak, respectively. We observed frequent de novo evolution of MDR and XDR, with 56 and nine independent evolutionary events, respectively. Isoniazid resistance evolved before rifampicin resistance 46 times, whereas rifampicin resistance evolved prior to isoniazid only twice. We identified additional putative compensatory mutations to rifampicin in this dataset. One major limitation of this study is that the conclusions with respect to ordering and timing of acquisition of mutations may not represent universal patterns of drug resistance emergence in other areas of the globe. CONCLUSIONS In the first whole genome-based analysis of the emergence of drug resistance among clinical isolates of M. tuberculosis, we show that the ancestral precursor of the LAM4 XDR outbreak strain in Tugela Ferry gained mutations to first-line drugs at the beginning of the antibiotic era. Subsequent accumulation of stepwise resistance mutations, occurring over decades and prior to the explosion of HIV in this region, yielded MDR and XDR, permitting the emergence of compensatory mutations. Our results suggest that drug-resistant strains circulating today reflect not only vulnerabilities of current TB control efforts but also those that date back 50 y. In drug-resistant TB, isoniazid resistance was overwhelmingly the initial resistance mutation to be acquired, which would not be detected by current rapid molecular diagnostics employed in South Africa that assess only rifampicin resistance.
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Evolution of extensively drug-resistant tuberculosis over four decades revealed by whole genome sequencing of Mycobacterium tuberculosis from KwaZulu-Natal, South Africa. Int J Mycobacteriol 2015. [DOI: 10.1016/j.ijmyco.2014.11.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Pilon: an integrated tool for comprehensive microbial variant detection and genome assembly improvement. PLoS One 2014; 9:e112963. [PMID: 25409509 PMCID: PMC4237348 DOI: 10.1371/journal.pone.0112963] [Citation(s) in RCA: 5091] [Impact Index Per Article: 509.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023] Open
Abstract
Advances in modern sequencing technologies allow us to generate sufficient data to analyze hundreds of bacterial genomes from a single machine in a single day. This potential for sequencing massive numbers of genomes calls for fully automated methods to produce high-quality assemblies and variant calls. We introduce Pilon, a fully automated, all-in-one tool for correcting draft assemblies and calling sequence variants of multiple sizes, including very large insertions and deletions. Pilon works with many types of sequence data, but is particularly strong when supplied with paired end data from two Illumina libraries with small e.g., 180 bp and large e.g., 3–5 Kb inserts. Pilon significantly improves draft genome assemblies by correcting bases, fixing mis-assemblies and filling gaps. For both haploid and diploid genomes, Pilon produces more contiguous genomes with fewer errors, enabling identification of more biologically relevant genes. Furthermore, Pilon identifies small variants with high accuracy as compared to state-of-the-art tools and is unique in its ability to accurately identify large sequence variants including duplications and resolve large insertions. Pilon is being used to improve the assemblies of thousands of new genomes and to identify variants from thousands of clinically relevant bacterial strains. Pilon is freely available as open source software.
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A method for the placement of the ceramic liner in an uncemented cup. Ann R Coll Surg Engl 2014; 96:250. [PMID: 24780810 DOI: 10.1308/rcsann.2014.96.3.250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
Listeria monocytogenes, a foodborne bacterial pathogen, is comprised of four phylogenetic lineages that vary with regard to their serotypes and distribution among sources. In order to characterize lineage-specific genomic diversity within L. monocytogenes, we sequenced the genomes of eight strains from several lineages and serotypes, and characterized the accessory genome, which was hypothesized to contribute to phenotypic differences across lineages. The eight L. monocytogenes genomes sequenced range in size from 2.85-3.14 Mb, encode 2,822-3,187 genes, and include the first publicly available sequenced representatives of serotypes 1/2c, 3a and 4c. Mapping of the distribution of accessory genes revealed two distinct regions of the L. monocytogenes chromosome: an accessory-rich region in the first 65° adjacent to the origin of replication and a more stable region in the remaining 295°. This pattern of genome organization is distinct from that of related bacteria Staphylococcus aureus and Bacillus cereus. The accessory genome of all lineages is enriched for cell surface-related genes and phosphotransferase systems, and transcriptional regulators, highlighting the selective pressures faced by contemporary strains from their hosts, other microbes, and their environment. Phylogenetic analysis of O-antigen genes and gene clusters predicts that serotype 4 was ancestral in L. monocytogenes and serotype 1/2 associated gene clusters were putatively introduced through horizontal gene transfer in the ancestral population of L. monocytogenes lineage I and II.
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Distinctive expansion of potential virulence genes in the genome of the oomycete fish pathogen Saprolegnia parasitica. PLoS Genet 2013; 9:e1003272. [PMID: 23785293 PMCID: PMC3681718 DOI: 10.1371/journal.pgen.1003272] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 12/10/2012] [Indexed: 01/31/2023] Open
Abstract
Oomycetes in the class Saprolegniomycetidae of the Eukaryotic kingdom Stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. We have sequenced the 63 Mb genome of the fresh water fish pathogen, Saprolegnia parasitica. Approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. Comparison of S. parasitica with plant pathogenic oomycetes suggests that during evolution the host cellular environment has driven distinct patterns of gene expansion and loss in the genomes of plant and animal pathogens. S. parasitica possesses one of the largest repertoires of proteases (270) among eukaryotes that are deployed in waves at different points during infection as determined from RNA-Seq data. In contrast, despite being capable of living saprotrophically, parasitism has led to loss of inorganic nitrogen and sulfur assimilation pathways, strikingly similar to losses in obligate plant pathogenic oomycetes and fungi. The large gene families that are hallmarks of plant pathogenic oomycetes such as Phytophthora appear to be lacking in S. parasitica, including those encoding RXLR effectors, Crinkler's, and Necrosis Inducing-Like Proteins (NLP). S. parasitica also has a very large kinome of 543 kinases, 10% of which is induced upon infection. Moreover, S. parasitica encodes several genes typical of animals or animal-pathogens and lacking from other oomycetes, including disintegrins and galactose-binding lectins, whose expression and evolutionary origins implicate horizontal gene transfer in the evolution of animal pathogenesis in S. parasitica. Fish are an increasingly important source of animal protein globally, with aquaculture production rising dramatically over the past decade. Saprolegnia is a fungal-like oomycete and one of the most destructive fish pathogens, causing millions of dollars in losses to the aquaculture industry annually. Saprolegnia has also been linked to a worldwide decline in wild fish and amphibian populations. Here we describe the genome sequence of the first animal pathogenic oomycete and compare the genome content with the available plant pathogenic oomycetes. We found that Saprolegnia lacks the large effector families that are hallmarks of plant pathogenic oomycetes, showing evolutionary adaptation to the host. Moreover, Saprolegnia harbors pathogenesis-related genes that were derived by lateral gene transfer from the host and other animal pathogens. The retrotransposon LINE family also appears to be acquired from animal lineages. By transcriptome analysis we show a high rate of allelic variation, which reveals rapidly evolving genes and potentially adaptive evolutionary mechanisms coupled to selective pressures exerted by the animal host. The genome and transcriptome data, as well as subsequent biochemical analyses, provided us with insight in the disease process of Saprolegnia at a molecular and cellular level, providing us with targets for sustainable control of Saprolegnia.
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Abstract
Exceptionally accurate genome reference sequences have proven to be of great value to microbial researchers. Thus, to date, about 1800 bacterial genome assemblies have been “finished” at great expense with the aid of manual laboratory and computational processes that typically iterate over a period of months or even years. By applying a new laboratory design and new assembly algorithm to 16 samples, we demonstrate that assemblies exceeding finished quality can be obtained from whole-genome shotgun data and automated computation. Cost and time requirements are thus dramatically reduced.
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Abstract
Eliminating the bacterial cloning step has been a major factor in the vastly improved efficiency of massively parallel sequencing approaches. However, this also has made it a technical challenge to produce the modern equivalent of the Fosmid- or BAC-end sequences that were crucial for assembling and analyzing complex genomes during the Sanger-based sequencing era. To close this technology gap, we developed Fosill, a method for converting Fosmids to Illumina-compatible jumping libraries. We constructed Fosmid libraries in vectors with Illumina primer sequences and specific nicking sites flanking the cloning site. Our family of pFosill vectors allows multiplex Fosmid cloning of end-tagged genomic fragments without physical size selection and is compatible with standard and multiplex paired-end Illumina sequencing. To excise the bulk of each cloned insert, we introduced two nicks in the vector, translated them into the inserts, and cleaved them. Recircularization of the vector via coligation of insert termini followed by inverse PCR generates a jumping library for paired-end sequencing with 101-base reads. The yield of unique Fosmid-sized jumps is sufficiently high, and the background of short, incorrectly spaced and chimeric artifacts sufficiently low, to enable applications such as mapping of structural variation and scaffolding of de novo assemblies. We demonstrate the power of Fosill to map genome rearrangements in a cancer cell line and identified three fusion genes that were corroborated by RNA-seq data. Our Fosill-powered assembly of the mouse genome has an N50 scaffold length of 17.0 Mb, rivaling the connectivity (16.9 Mb) of the Sanger-sequencing based draft assembly.
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Linkage to the mating-type locus across the genus Microbotryum: insights into nonrecombining chromosomes. Evolution 2012; 66:3519-33. [PMID: 23106715 DOI: 10.1111/j.1558-5646.2012.01703.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Parallels have been drawn between the evolution of nonrecombining regions in fungal mating-type chromosomes and animal and plant sex chromosomes, particularly regarding the stages of recombination cessation forming evolutionary strata of allelic divergence. Currently, evidence and explanations for recombination cessation in fungi are sparse, and the presence of evolutionary strata has been examined in a minimal number of fungal taxa. Here, the basidiomycete genus Microbotryum was used to determine the history of recombination cessation for loci on the mating-type chromosomes. Ancestry of linkage with mating type for 13 loci was assessed across 20 species by a phylogenetic method. No locus was found to exhibit trans-specific polymorphism for alternate alleles as old as the mating pheromone receptor, indicating that ages of linkage to mating type varied among the loci. The ordering of loci in the ancestry of linkage to mating type does not agree with their previously proposed assignments to evolutionary strata. This study suggests that processes capable of influencing divergence between alternate alleles may act at loci in the nonrecombining regions (e.g., gene conversion) and encourages further work to dissect the evolutionary processes acting upon genomic regions that determine mating compatibility.
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Whole genome deep sequencing of HIV-1 reveals the impact of early minor variants upon immune recognition during acute infection. PLoS Pathog 2012; 8:e1002529. [PMID: 22412369 PMCID: PMC3297584 DOI: 10.1371/journal.ppat.1002529] [Citation(s) in RCA: 287] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Accepted: 12/27/2011] [Indexed: 12/20/2022] Open
Abstract
Deep sequencing technologies have the potential to transform the study of highly variable viral pathogens by providing a rapid and cost-effective approach to sensitively characterize rapidly evolving viral quasispecies. Here, we report on a high-throughput whole HIV-1 genome deep sequencing platform that combines 454 pyrosequencing with novel assembly and variant detection algorithms. In one subject we combined these genetic data with detailed immunological analyses to comprehensively evaluate viral evolution and immune escape during the acute phase of HIV-1 infection. The majority of early, low frequency mutations represented viral adaptation to host CD8+ T cell responses, evidence of strong immune selection pressure occurring during the early decline from peak viremia. CD8+ T cell responses capable of recognizing these low frequency escape variants coincided with the selection and evolution of more effective secondary HLA-anchor escape mutations. Frequent, and in some cases rapid, reversion of transmitted mutations was also observed across the viral genome. When located within restricted CD8 epitopes these low frequency reverting mutations were sufficient to prime de novo responses to these epitopes, again illustrating the capacity of the immune response to recognize and respond to low frequency variants. More importantly, rapid viral escape from the most immunodominant CD8+ T cell responses coincided with plateauing of the initial viral load decline in this subject, suggestive of a potential link between maintenance of effective, dominant CD8 responses and the degree of early viremia reduction. We conclude that the early control of HIV-1 replication by immunodominant CD8+ T cell responses may be substantially influenced by rapid, low frequency viral adaptations not detected by conventional sequencing approaches, which warrants further investigation. These data support the critical need for vaccine-induced CD8+ T cell responses to target more highly constrained regions of the virus in order to ensure the maintenance of immunodominant CD8 responses and the sustained decline of early viremia. The ability of HIV-1 and other highly variable pathogens to rapidly mutate to escape vaccine-induced immune responses represents a major hurdle to the development of effective vaccines to these highly persistent pathogens. Application of next-generation or deep sequencing technologies to the study of host pathogens could significantly improve our understanding of the mechanisms by which these pathogens subvert host immunity, and aid in the development of novel vaccines and therapeutics. Here, we developed a 454 deep sequencing approach to enable the sensitive detection of low-frequency viral variants across the entire HIV-1 genome. When applied to the acute phase of HIV-1 infection we observed that the majority of early, low frequency mutations represented viral adaptations to host cellular immune responses, evidence of strong host immunity developing during the early decline of peak viral load. Rapid viral escape from the most dominant immune responses however correlated with loss of this initial viral control, suggestive of the importance of mounting immune responses against more conserved regions of the virus. These data provide a greater understanding of the early evolutionary events subverting the ability of host immune responses to control early HIV-1 replication, yielding important insight into the design of more effective vaccine strategies.
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Spiteful interactions between sympatric natural isolates of Xenorhabdus bovienii benefit kin and reduce virulence. J Evol Biol 2012; 25:431-7. [PMID: 22221661 DOI: 10.1111/j.1420-9101.2011.02441.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Spite occurs when an individual harms itself in the act of harming others. Spiteful behaviour may be more pervasive in nature than commonly thought. One of the clearest examples of spite is the costly production and release of bacteriocins, antimicrobial toxins noted for their ability to kill conspecifics. A key question is to what extent these toxins provide a fitness advantage to kin of the producer cell, especially in natural communities. Additionally, when bacteria are involved in parasitic relationships, spiteful interactions are predicted to lower bacterial densities within a host, causing a reduction in parasite-induced virulence. Using five sympatric, field-collected genotypes of the insect pathogen Xenorhabdus bovienii, we experimentally demonstrate that bacteriocin production benefits kin within the host, and that it slows the mortality rate of the host. These results confirm that spite among naturally coexisting bacterial clones can be a successful kin-selected strategy that has emergent effects on virulence.
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Abstract
The fission yeast clade--comprising Schizosaccharomyces pombe, S. octosporus, S. cryophilus, and S. japonicus--occupies the basal branch of Ascomycete fungi and is an important model of eukaryote biology. A comparative annotation of these genomes identified a near extinction of transposons and the associated innovation of transposon-free centromeres. Expression analysis established that meiotic genes are subject to antisense transcription during vegetative growth, which suggests a mechanism for their tight regulation. In addition, trans-acting regulators control new genes within the context of expanded functional modules for meiosis and stress response. Differences in gene content and regulation also explain why, unlike the budding yeast of Saccharomycotina, fission yeasts cannot use ethanol as a primary carbon source. These analyses elucidate the genome structure and gene regulation of fission yeast and provide tools for investigation across the Schizosaccharomyces clade.
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Analysis of high-throughput sequencing and annotation strategies for phage genomes. PLoS One 2010; 5:e9083. [PMID: 20140207 PMCID: PMC2816706 DOI: 10.1371/journal.pone.0009083] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 01/18/2010] [Indexed: 11/18/2022] Open
Abstract
Background Bacterial viruses (phages) play a critical role in shaping microbial populations as they influence both host mortality and horizontal gene transfer. As such, they have a significant impact on local and global ecosystem function and human health. Despite their importance, little is known about the genomic diversity harbored in phages, as methods to capture complete phage genomes have been hampered by the lack of knowledge about the target genomes, and difficulties in generating sufficient quantities of genomic DNA for sequencing. Of the approximately 550 phage genomes currently available in the public domain, fewer than 5% are marine phage. Methodology/Principal Findings To advance the study of phage biology through comparative genomic approaches we used marine cyanophage as a model system. We compared DNA preparation methodologies (DNA extraction directly from either phage lysates or CsCl purified phage particles), and sequencing strategies that utilize either Sanger sequencing of a linker amplification shotgun library (LASL) or of a whole genome shotgun library (WGSL), or 454 pyrosequencing methods. We demonstrate that genomic DNA sample preparation directly from a phage lysate, combined with 454 pyrosequencing, is best suited for phage genome sequencing at scale, as this method is capable of capturing complete continuous genomes with high accuracy. In addition, we describe an automated annotation informatics pipeline that delivers high-quality annotation and yields few false positives and negatives in ORF calling. Conclusions/Significance These DNA preparation, sequencing and annotation strategies enable a high-throughput approach to the burgeoning field of phage genomics.
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Naturally occurring dominant resistance mutations to hepatitis C virus protease and polymerase inhibitors in treatment-naïve patients. Hepatology 2008; 48:1769-78. [PMID: 19026009 PMCID: PMC2645896 DOI: 10.1002/hep.22549] [Citation(s) in RCA: 311] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
UNLABELLED Resistance mutations to hepatitis C virus (HCV) nonstructural protein 3 (NS3) protease inhibitors in <1% of the viral quasispecies may still allow >1000-fold viral load reductions upon treatment, consistent with their reported reduced replicative fitness in vitro. Recently, however, an R155K protease mutation was reported as the dominant quasispecies in a treatment-naïve individual, raising concerns about possible full drug resistance. To investigate the prevalence of dominant resistance mutations against specifically targeted antiviral therapy for HCV (STAT-C) in the population, we analyzed HCV genome sequences from 507 treatment-naïve patients infected with HCV genotype 1 from the United States, Germany, and Switzerland. Phylogenetic sequence analysis and viral load data were used to identify the possible spread of replication-competent, drug-resistant viral strains in the population and to infer the consequences of these mutations upon viral replication in vivo. Mutations described to confer resistance to the protease inhibitors Telaprevir, BILN2061, ITMN-191, SCH6 and Boceprevir; the NS5B polymerase inhibitor AG-021541; and to the NS4A antagonist ACH-806 were observed mostly as sporadic, unrelated cases, at frequencies between 0.3% and 2.8% in the population, including two patients with possible multidrug resistance. Collectively, however, 8.6% of the patients infected with genotype 1a and 1.4% of those infected with genotype 1b carried at least one dominant resistance mutation. Viral loads were high in the majority of these patients, suggesting that drug-resistant viral strains might achieve replication levels comparable to nonresistant viruses in vivo. CONCLUSION Naturally occurring dominant STAT-C resistance mutations are common in treatment-naïve patients infected with HCV genotype 1. Their influence on treatment outcome should further be characterized to evaluate possible benefits of drug resistance testing for individual tailoring of drug combinations when treatment options are limited due to previous nonresponse to peginterferon and ribavirin.
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Short-term genome evolution of Listeria monocytogenes in a non-controlled environment. BMC Genomics 2008; 9:539. [PMID: 19014550 PMCID: PMC2642827 DOI: 10.1186/1471-2164-9-539] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 11/13/2008] [Indexed: 12/23/2022] Open
Abstract
Background While increasing data on bacterial evolution in controlled environments are available, our understanding of bacterial genome evolution in natural environments is limited. We thus performed full genome analyses on four Listeria monocytogenes, including human and food isolates from both a 1988 case of sporadic listeriosis and a 2000 listeriosis outbreak, which had been linked to contaminated food from a single processing facility. All four isolates had been shown to have identical subtypes, suggesting that a specific L. monocytogenes strain persisted in this processing plant over at least 12 years. While a genome sequence for the 1988 food isolate has been reported, we sequenced the genomes of the 1988 human isolate as well as a human and a food isolate from the 2000 outbreak to allow for comparative genome analyses. Results The two L. monocytogenes isolates from 1988 and the two isolates from 2000 had highly similar genome backbone sequences with very few single nucleotide (nt) polymorphisms (1 – 8 SNPs/isolate; confirmed by re-sequencing). While no genome rearrangements were identified in the backbone genome of the four isolates, a 42 kb prophage inserted in the chromosomal comK gene showed evidence for major genome rearrangements. The human-food isolate pair from each 1988 and 2000 had identical prophage sequence; however, there were significant differences in the prophage sequences between the 1988 and 2000 isolates. Diversification of this prophage appears to have been caused by multiple homologous recombination events or possibly prophage replacement. In addition, only the 2000 human isolate contained a plasmid, suggesting plasmid loss or acquisition events. Surprisingly, besides the polymorphisms found in the comK prophage, a single SNP in the tRNA Thr-4 prophage represents the only SNP that differentiates the 1988 isolates from the 2000 isolates. Conclusion Our data support the hypothesis that the 2000 human listeriosis outbreak was caused by a L. monocytogenes strain that persisted in a food processing facility over 12 years and show that genome sequencing is a valuable and feasible tool for retrospective epidemiological analyses. Short-term evolution of L. monocytogenes in non-controlled environments appears to involve limited diversification beyond plasmid gain or loss and prophage diversification, highlighting the importance of phages in bacterial evolution.
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DNA sequence of human chromosome 17 and analysis of rearrangement in the human lineage. Nature 2006; 440:1045-9. [PMID: 16625196 PMCID: PMC2610434 DOI: 10.1038/nature04689] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 03/01/2006] [Indexed: 11/08/2022]
Abstract
Chromosome 17 is unusual among the human chromosomes in many respects. It is the largest human autosome with orthology to only a single mouse chromosome, mapping entirely to the distal half of mouse chromosome 11. Chromosome 17 is rich in protein-coding genes, having the second highest gene density in the genome. It is also enriched in segmental duplications, ranking third in density among the autosomes. Here we report a finished sequence for human chromosome 17, as well as a structural comparison with the finished sequence for mouse chromosome 11, the first finished mouse chromosome. Comparison of the orthologous regions reveals striking differences. In contrast to the typical pattern seen in mammalian evolution, the human sequence has undergone extensive intrachromosomal rearrangement, whereas the mouse sequence has been remarkably stable. Moreover, although the human sequence has a high density of segmental duplication, the mouse sequence has a very low density. Notably, these segmental duplications correspond closely to the sites of structural rearrangement, demonstrating a link between duplication and rearrangement. Examination of the main classes of duplicated segments provides insight into the dynamics underlying expansion of chromosome-specific, low-copy repeats in the human genome.
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Analysis of the DNA sequence and duplication history of human chromosome 15. Nature 2006; 440:671-5. [PMID: 16572171 DOI: 10.1038/nature04601] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Accepted: 01/26/2006] [Indexed: 11/09/2022]
Abstract
Here we present a finished sequence of human chromosome 15, together with a high-quality gene catalogue. As chromosome 15 is one of seven human chromosomes with a high rate of segmental duplication, we have carried out a detailed analysis of the duplication structure of the chromosome. Segmental duplications in chromosome 15 are largely clustered in two regions, on proximal and distal 15q; the proximal region is notable because recombination among the segmental duplications can result in deletions causing Prader-Willi and Angelman syndromes. Sequence analysis shows that the proximal and distal regions of 15q share extensive ancient similarity. Using a simple approach, we have been able to reconstruct many of the events by which the current duplication structure arose. We find that most of the intrachromosomal duplications seem to share a common ancestry. Finally, we demonstrate that some remaining gaps in the genome sequence are probably due to structural polymorphisms between haplotypes; this may explain a significant fraction of the gaps remaining in the human genome.
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DNA sequence and analysis of human chromosome 8. Nature 2006; 439:331-5. [PMID: 16421571 DOI: 10.1038/nature04406] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Accepted: 10/06/2005] [Indexed: 11/09/2022]
Abstract
The International Human Genome Sequencing Consortium (IHGSC) recently completed a sequence of the human genome. As part of this project, we have focused on chromosome 8. Although some chromosomes exhibit extreme characteristics in terms of length, gene content, repeat content and fraction segmentally duplicated, chromosome 8 is distinctly typical in character, being very close to the genome median in each of these aspects. This work describes a finished sequence and gene catalogue for the chromosome, which represents just over 5% of the euchromatic human genome. A unique feature of the chromosome is a vast region of approximately 15 megabases on distal 8p that appears to have a strikingly high mutation rate, which has accelerated in the hominids relative to other sequenced mammals. This fast-evolving region contains a number of genes related to innate immunity and the nervous system, including loci that appear to be under positive selection--these include the major defensin (DEF) gene cluster and MCPH1, a gene that may have contributed to the evolution of expanded brain size in the great apes. The data from chromosome 8 should allow a better understanding of both normal and disease biology and genome evolution.
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Abstract
Chromosome 18 appears to have the lowest gene density of any human chromosome and is one of only three chromosomes for which trisomic individuals survive to term. There are also a number of genetic disorders stemming from chromosome 18 trisomy and aneuploidy. Here we report the finished sequence and gene annotation of human chromosome 18, which will allow a better understanding of the normal and disease biology of this chromosome. Despite the low density of protein-coding genes on chromosome 18, we find that the proportion of non-protein-coding sequences evolutionarily conserved among mammals is close to the genome-wide average. Extending this analysis to the entire human genome, we find that the density of conserved non-protein-coding sequences is largely uncorrelated with gene density. This has important implications for the nature and roles of non-protein-coding sequence elements.
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Neutrophil maturation and activation determine anatomic site of clearance from circulation. Am J Physiol Lung Cell Mol Physiol 2001; 281:L913-21. [PMID: 11557595 DOI: 10.1152/ajplung.2001.281.4.l913] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The long-term disposition of circulating neutrophils and the site of disappearance from circulation remain unclear. We investigated neutrophil localization in mice using (111)In-labeled murine peripheral blood neutrophils, mature bone marrow neutrophils, and peritoneal exudate neutrophils to track in vivo localization of these different cell populations. Infused peripheral neutrophils were found to localize equally between liver and marrow sites by 4 h (31.2 +/- 1.9 vs. 31.9 +/- 1.8%), whereas exudate neutrophils predominantly localized to liver (42.0 +/- 1.1%) and marrow-derived neutrophils to the marrow (65.9 +/- 6.6%) where they were found to localize predominantly in the hematopoietic cords. Stimulation of marrow neutrophils before infusion caused a shift in localization from marrow to liver, and subsequent induction of an inflammatory site after infusion and marrow sequestration led to remobilization of infused marrow neutrophils but not of peripheral neutrophils. These results indicate that the marrow participates in removing neutrophils from circulation, with evidence supporting both storage and perhaps disposal functions. Furthermore, models for circulating neutrophil homeostasis should consider that the site of retention is governed by the maturation and activation states of the cell.
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Conceptual database modeling: a method for enabling end users (radiologists) to understand and develop their information management applications. J Digit Imaging 2001; 14:195-6. [PMID: 11442094 PMCID: PMC3452691 DOI: 10.1007/bf03190336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
As medical technology advances at a rapid pace, clinicians become further and further removed from the design of their own technological tools. This is particularly evident with information management. For radiologists, clinical histories, patient reports, and other pertinent information require sophisticated tools for data handling. However, as databases grow more powerful and sophisticated, systems require the expertise of programmers and information technology personnel. The radiologist, the clinician end-user, must maintain involvement in the development of system tools to insure effective information management. Conceptual database modeling is a design method that serves to bridge the gap between the technological aspects of information management and its clinical applications. Conceptual database modeling involves developing information systems in simple language so that anyone can have input into the overall design. This presentation describes conceptual database modeling, using object role modeling, as a means by which end-users (clinicians) may participate in database development.
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The future: building on the past. JOURNAL - OKLAHOMA DENTAL ASSOCIATION 2001; 90:32-6. [PMID: 11314310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Abstract
In response to rising health care costs and changing expectations concerning the quality of health care, information management is becoming increasingly important in the practice of medicine; more specifically, it is beginning to effect significant changes in radiology practice and patient care. Radiologic applications of information management include reporting diagnostic information generated from film interpretation as well as tracking utilization patterns of different imaging modalities and the variability of clinical outcomes, documenting the type of information sought by and provided to clinicians, and evaluating departmental quality standards and performance goals. Conceptual database modeling enables radiologists to understand and participate in the development of information systems, thereby improving the likelihood of successful results. In object-role modeling, groups of relevant objects and roles are identified and used to create elementary facts that form the "building blocks" for information models. The resultant models can easily be communicated, reviewed, and revised, allowing decreased development time and optimizing inclusion of relevant features in the target relational database. Increasing the amount of clinical and management input in the development process may help information systems better meet user needs, become accepted and more often used, and ultimately succeed.
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Role of p38 mitogen-activated protein kinase in a murine model of pulmonary inflammation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:2151-9. [PMID: 10657669 DOI: 10.4049/jimmunol.164.4.2151] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Early inflammatory events include cytokine release, activation, and rapid accumulation of neutrophils, with subsequent recruitment of mononuclear cells. The p38 mitogen-activated protein kinase (MAPK) intracellular signaling pathway plays a central role in regulating a wide range of inflammatory responses in many different cells. A murine model of mild LPS-induced lung inflammation was developed to investigate the role of the p38 MAPK pathway in the initiation of pulmonary inflammation. A novel p38 MAPK inhibitor, M39, was used to determine the functional consequences of p38 MAPK activation. In vitro exposure to M39 inhibited p38 MAPK activity in LPS-stimulated murine and human neutrophils and macrophages, blocked TNF-alpha and macrophage inflammatory protein-2 (MIP-2) release, and eliminated migration of murine neutrophils toward the chemokines MIP-2 and KC. In contrast, alveolar macrophages required a 1000-fold greater concentration of M39 to block release of TNF-alpha and MIP-2. Systemic inhibition of p38 MAPK resulted in significant decreases in the release of TNF-alpha and neutrophil accumulation in the airspaces following intratracheal administration of LPS. Recovery of MIP-2 and KC from the airspaces was not affected by inhibition of p38 MAPK, and accumulation of mononuclear cells was not significantly reduced. When KC was instilled as a proinflammatory stimulus, neutrophil accumulation was significantly decreased by p38 MAPK inhibition independent of TNF-alpha or LPS. Together, these results demonstrate a much greater dependence on the p38 MAPK cascade in the neutrophil when compared with other leukocytes, and suggest a means of selectively studying and potentially modulating early inflammation in the lung.
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Malignant accessions 1974-1996. JOURNAL - OKLAHOMA DENTAL ASSOCIATION 1999; 89:18-21. [PMID: 10596629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Abstract
The role of infant and toddler temperament in the prediction of empathy in 2-year-old children was examined. Assessments of temperament included reactivity and affect observed at 4 months of age, as well as inhibition at Age 2. Empathy was measured in 2-year-old children's responses to simulations of distress performed by their mothers and by an unfamiliar person. Children showed relatively more concern for the mother's distress, but they were also responsive to unfamiliar victims. Infants who were unreactive and showed little affect also showed less empathy toward the unfamiliar adult almost 2 years later. Inhibition toward an unfamiliar adult (but not toward the mother) at 2 years of age was negatively related to empathy. Inhibited temperament may thus have a major impact on young children's empathy in unfamiliar contexts. Findings also highlight the need to consider early underarousal as another dimension of temperament that may dampen expressions of empathic concern.
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Abstract
Wound healing is a complex process that involves inflammation, apoptosis, growth, and tissue remodeling. The autoimmune-prone inbred mouse strain MRL/+ manifests accelerated and extensive healing to ear punch wounds, suggesting a link between immune defects and wound healing. Prior studies with lupus-prone mice have shown that hematopoietic cells of lupus-prone strains can transfer disease to otherwise non-autoimmune-prone recipients. In this study we performed reciprocal bone marrow transfers between MRL and the control strain B10.BR and found that radioresistant MRL/+ host cells, rather than hematopoietic cells, are required for the healing response. We have also made the novel observations that, compared to normal controls, MRL/+ hematopoietic cells overproduce TGF-beta1 and manifest impaired inflammatory responses to lipopolysaccharide challenge. These features suggest that the aberrant wound healing phenotype of MRL mice is independent of their propensity to develop autoimmunity.
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46
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Abstract
The role of infant and toddler temperament in the prediction of empathy in 2-year-old children was examined. Assessments of temperament included reactivity and affect observed at 4 months of age, as well as inhibition at Age 2. Empathy was measured in 2-year-old children's responses to simulations of distress performed by their mothers and by an unfamiliar person. Children showed relatively more concern for the mother's distress, but they were also responsive to unfamiliar victims. Infants who were unreactive and showed little affect also showed less empathy toward the unfamiliar adult almost 2 years later. Inhibition toward an unfamiliar adult (but not toward the mother) at 2 years of age was negatively related to empathy. Inhibited temperament may thus have a major impact on young children's empathy in unfamiliar contexts. Findings also highlight the need to consider early underarousal as another dimension of temperament that may dampen expressions of empathic concern.
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An intracellular signaling pathway linking lipopolysaccharide stimulation to cellular responses of the human neutrophil: the p38 MAP kinase cascade and its functional significance. Chest 1999; 116:54S-55S. [PMID: 10424591 DOI: 10.1378/chest.116.suppl_1.54s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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48
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Selective activation and functional significance of p38alpha mitogen-activated protein kinase in lipopolysaccharide-stimulated neutrophils. J Clin Invest 1999; 103:851-8. [PMID: 10079106 PMCID: PMC408145 DOI: 10.1172/jci5257] [Citation(s) in RCA: 245] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Activation of leukocytes by proinflammatory stimuli selectively initiates intracellular signal transduction via sequential phosphorylation of kinases. Lipopolysaccharide (LPS) stimulation of human neutrophils is known to result in activation of p38 mitogen-activated protein kinase (MAPk); however, the upstream activator(s) of p38 MAPk is unknown, and consequences of p38 MAPk activation remain largely undefined. We investigated the MAPk kinase (MKK) that activates p38 MAPk in response to LPS, the p38 MAPk isoforms that are activated as part of this pathway, and the functional responses affected by p38 MAPk activation. Although MKK3, MKK4, and MKK6 all activated p38 MAPk in experimental models, only MKK3 was found to activate recombinant p38 MAPk in LPS-treated neutrophils. Of p38 MAPk isoforms studied, only p38alpha and p38delta were detected in neutrophils. LPS stimulation selectively activated p38alpha. Specific inhibitors of p38alpha MAPk blocked LPS-induced adhesion, nuclear factor-kappa B (NF-kappaB) activation, and synthesis of tumor necrosis factor-alpha (TNF-alpha). Inhibition of p38alpha MAPk resulted in a transient decrease in TNF-alpha mRNA accumulation but persistent loss of TNF-alpha synthesis. These findings support a pathway by which LPS stimulation of neutrophils results in activation of MKK3, which in turn activates p38alpha MAPk, ultimately regulating adhesion, NF-kappaB activation, enhanced gene expression of TNF-alpha, and regulation of TNF-alpha synthesis.
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In vivo delivery of recombinant human growth hormone from genetically engineered human fibroblasts implanted within Baxter immunoisolation devices. J Mol Med (Berl) 1999; 77:211-4. [PMID: 9930965 DOI: 10.1007/s001090050338] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Continuous delivery of therapeutic peptide to the systemic circulation would be the optimal treatment for a variety of diseases. The Baxter TheraCyte system is a membrane encapsulation system developed for implantation of tissues, cells such as endocrine cells or cell lines genetically engineered for therapeutic peptide delivery in vivo. To demonstrate the utility of this system, cell lines were developed which expressed human growth hormone (hGH) at levels exceeding 1 microgram per million cells per day. These were loaded into devices which were then implanted into juvenile nude rats. Significant levels of hGH of up to 2.5 ng/ml were detected in plasma throughout the six month duration of the study. In contrast, animals implanted with free cells showed peak plasma levels of 0.5 to 1.2 ng four days after implantation with no detectable hGH beyond 10 days. Histological examination of explanted devices showed they were vascularized and contained cells that were viable and morphologically healthy. After removal of the implants, no hGH could be detected which confirmed that the source of hGH was from cells contained within the device. The long term expression of human growth hormone as a model peptide has implications for the peptide therapies for a variety of human diseases using membrane encapsulated cells.
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50
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Abstract
Fourteen consecutive cases with type 4 fracture of the medial epicondyle were evaluated following open reduction and internal fixation of the displaced medial epicondyle. The mean age was 9.7 years (range 6-16) and the mean follow-up was 17.2 months (range 12-24). Operative treatment yielded excellent results with no loss of functional range of motion, residual deformity or instability. There were three cases with pre-operative symptoms of ulnar nerve injury which made a good recovery following neurolysis of the ulnar nerve. Type 4 fractures are commonly associated with intra-articular entrapment of the ulnar nerve and result from serious damage to the soft tissues on the medial side of the elbow. Assessing instability is therefore of key importance, as is the intra-operative gravity stress-valgus test in assessing instability.
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