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The degree of heterogeneity associated with geographic origin and sebaceous adenitis (SA) status in Standard Poodles from the United States (US) and the United Kingdom (UK) was assessed. Healthy and SA-affected Standard Poodles from the US and the UK shared a major mitochondrial DNA (mtDNA) haplotype and a single Y chromosome haplotype. However, minor mtDNA haplotypes and frequencies were somewhat different between US and UK dogs and were significantly less associated with SA than major haplotypes across both populations. The US and UK populations exhibited recent divergence from a common gene pool, based on allele frequencies of 24 highly polymorphic short tandem repeats and principle coordinates and cluster analyses of genotype frequencies. However, there was no differentiation between SA affected and unaffected dogs. Over 90% of US and UK Poodles shared a common dog leukocyte antigen (DLA) class II haplotype, but showed some differentiation in minor haplotype frequency. No difference was observed in haplotype heterozygosity between SA affected and unaffected dogs from the same country and no disease association for SA was found within the DLA region by a high density single nucleotide polymorphism (SNP) scan. Zygosity mapping in the DLA region of Poodles indicated much lower site-specific diversity than in an outbred population of street dogs from Bali, Indonesia, reflecting the degree that breed associated historical bottlenecks have reduced diversity in a polymorphic region of the genome. This study shows possible pitfalls in more extensive genome-wide association studies, such as case and control numbers, population stratification, the involvement of multiple genes, and/or the possibility that SA susceptibility is fixed or nearly fixed within the breed, which can reduce power to detect genetic associations.  相似文献   

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We have compared molecular, immunochemical, and cytotoxic assays for the detection of diphtheria toxin from 55 isolates of Corynebacterium diphtheriae and Corynebacterium ulcerans originally isolated in five different countries. The suitabilities and accuracies of these assays for the laboratory diagnosis of diphtheria were compared and evaluated against the “gold standard” in vivo methods. The in vivo and Vero cell cytotoxicity assays were accurate in their abilities to detect diphtheria toxin but were time-consuming; however, the cytotoxicity assay is a suitable in vitro alternative to the in vivo virulence test. There was complete concordance between all the phenotypic methods. Genotypic tests based upon PCR were rapid; however, PCR must be used with caution because some isolates of C. diphtheriae possessed toxin genes but failed to express a biologically active toxin. Therefore, phenotypic confirmation of toxigenicity for the microbiological diagnosis of diphtheria is recommended.  相似文献   

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We report here the laboratory investigation of the first known case of botulism in the United States caused by Clostridium butyricum type E. This investigation demonstrates the importance of extensive microbiological examination of specimens, which resulted in the isolation of this organism.  相似文献   

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The cell-based anthrax toxin neutralization assay (TNA) is used to determine functional antibody titers of sera from animals and humans immunized with anthrax vaccines. The anthrax lethal toxin is a critical reagent of the TNA composed of protective antigen (PA) and lethal factor (LF), which are neutralization targets of serum antibodies. Cytotoxic potency of recombinant LF (rLF) lots can vary substantially, causing a challenge in producing a renewable supply of this reagent for validated TNAs. To address this issue, we characterized a more potent rLF variant (rLF-A) with the exact native LF amino acid sequence that lacks the additional N-terminal histidine and methionine residues present on the commonly used form of rLF (rLF-HMA) as a consequence of the expression vector. rLF-A can be used at 4 to 6 ng/ml (in contrast to 40 ng/ml rLF-HMA) with 50 ng/ml recombinant PA (rPA) to achieve 95 to 99% cytotoxicity. In the presence of 50 ng/ml rPA, both rLF-A and rLF-HMA allowed for similar potencies (50% effective dilution) among immune sera in the TNA. rPA, but not rLF, was the dominant factor in determining potency of serum samples containing anti-PA antibodies only or an excess of anti-PA relative to anti-rLF antibodies. Such anti-PA content is reflected in immune sera derived from most anthrax vaccines in development. These results support that 7- to 10-fold less rLF-A can be used in place of rLF-HMA without changing TNA serum dilution curve parameters, thus extending the use of a single rLF lot and a consistent, renewable supply.  相似文献   

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Little data exist on how opioid doses vary with the length of exposure among chronic opioid users.  相似文献   

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Numerous reports have documented that serologic methods are much more sensitive than culture for the diagnosis of pertussis in adolescents and adults. However, a standardized serologic test for pertussis is not routinely available to most clinicians, and the serologic test levels or cutoff points correlated with diseases have not been determined. The goal of the present study was to examine the distribution of immunoglobulin G (IgG) levels against three Bordetella pertussis antigens (pertussis toxin [PT], filamentous hemagglutinin [FHA], and fimbria types 2 and 3 [FIM]) and to determine population-based antibody levels for the purpose of establishing such diagnostic cutoff points. Enzyme-linked immunosorbent assays (ELISAs) were performed with sera from >6,000 U.S. residents aged 6 to 49 years who participated in the Third National Health and Nutrition Examination Survey. Mixture models were developed to identify hypothesized exposure groups and establish diagnostic cutoffs. Quantifiable (>20 ELISA units/ml [EU]) anti-FHA and anti-FIM IgG antibodies were common (65 and 62% of individuals, respectively), but quantifiable anti-PT IgG antibodies were less frequent (16%). Given the distributions of antibody levels, an anti-PT IgG level of ≥94 EU was proposed as the diagnostic cutoff point. Application of this cutoff point to culture-confirmed illness in a prior study investigating cough illness yielded a high diagnostic sensitivity (80%) and specificity (93%). A standardized ELISA for anti-PT IgG with a single serum sample appears to be useful for the identification of recent B. pertussis infection in adolescents and adults with cough illness. The PT cutoff point will be further evaluated in prospective studies of confirmed B. pertussis infection.  相似文献   

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OBJECTIVES: A population-based study was used to describe healthcare seeking behavior for menopausal symptoms and treatment among women 40-65 years old in the United States. METHODS: Participants were recruited into the Menopause Epidemiology Study from the KnowledgePanel(SM), which is selected by random digit dialing and probability sampling from the US population. From this source, 6201 women 40-65 years old were contacted and 4402 women participated. From the 3135 peri- and postmenopausal women, detailed information was obtained on menopausal symptoms, healthcare seeking, medication usage, and symptom relief from the medication. RESULTS: Many women (60%) reported seeking health care for their menopausal symptoms. More than half of these women sought health care in the past 12 months. Vasomotor symptoms were the most frequently reported menopause symptoms across all races/ethnicities, and the most common symptoms discussed with a health care professional. One-third of the women (34%) used only hormone therapies, 12% used complementary and/or alternative medicines, and 16% used both for treatment of menopausal symptoms. CONCLUSIONS: This study has shown that a large number of women consult healthcare providers for menopausal symptoms, indicating these symptoms are bothersome. Yet, in the United States, there is considerable variation in the symptomatology, healthcare seeking, and use of therapies for menopausal symptoms across cultures. To alleviate these symptoms women have tried alternative treatments as well as hormone therapies, yet many women did not get complete relief of specific symptoms.  相似文献   

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