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31.
The adenine nucleotide transporter (ANT) mediates exchange of cytosolic ADP and mitochondrial ATP. Although most species contain more than one ANT family member, it is not known whether their roles in developmental processes are redundant or specific. Here, we show that the Caenorhabditis elegans genome encodes four candidate ant genes (ant-1.1, ant-1.2, ant-1.3, and ant-1.4). We have investigated their spatiotemporal expression patterns and discovered that, whereas ANT-1.1 is a ubiquitously expressed mitochondrial protein, the other three ANT proteins show a restricted range of cell type expression. Moreover, only the disruption of ant-1.1 function, through RNA interference (RNAi), gives a mutant phenotype. Most of the ant-1.1(RNAi) mutant embryos arrest before the morphogenesis stage. Furthermore, ant-1.1 is also required postembryonically because RNAi mutants exhibit small size and life-span extension. Our results suggest that ant-1.1 is the only ant gene strictly required for embryonic and postembryonic development in C. elegans.  相似文献   
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BackgroundSerosurveys for SARS-CoV-2 aim to estimate the proportion of the population that has been infected.AimThis observational study assesses the seroprevalence of SARS-CoV-2 antibodies in Ontario, Canada during the first pandemic wave.MethodsUsing an orthogonal approach, we tested 8,902 residual specimens from the Public Health Ontario laboratory over three time periods during March–June 2020 and stratified results by age group, sex and region. We adjusted for antibody test sensitivity/specificity and compared with reported PCR-confirmed COVID-19 cases.ResultsAdjusted seroprevalence was 0.5% (95% confidence interval (CI): 0.1–1.5) from 27 March–30 April, 1.5% (95% CI: 0.7–2.2) from 26–31 May, and 1.1% (95% CI: 0.8–1.3) from 5–30 June 2020. Adjusted estimates were highest in individuals aged ≥ 60 years in March–April (1.3%; 95% CI: 0.2–4.6), in those aged 20–59 years in May (2.1%; 95% CI: 0.8–3.4) and in those aged ≥ 60 years in June (1.6%; 95% CI: 1.1–2.1). Regional seroprevalence varied, and was highest for Toronto in March–April (0.9%; 95% CI: 0.1–3.1), for Toronto in May (3.2%; 95% CI: 1.0–5.3) and for Toronto (1.5%; 95% CI: 0.9–2.1) and Central East in June (1.5%; 95% CI: 1.0–2.0). We estimate that COVID-19 cases detected by PCR in Ontario underestimated SARS-CoV-2 infections by a factor of 4.9.ConclusionsOur results indicate low population seroprevalence in Ontario, suggesting that public health measures were effective at limiting the spread of SARS-CoV-2 during the first pandemic wave.  相似文献   
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The authors' objective was to determine whether residential proximity to an industrial park (IP) is associated with increased perinatal mortality (PM). This semiecological study included 63,850 delivered births with 840 cases of PM (1995-2000). The authors categorized the study populations by ethnicity (ie, Bedouin and Jewish) and type of locality. Residential distance from the IP served as a surrogate indicator of exposure. Among Bedouin newborns, proximity to the IP was associated with increased PM rates (relative risk = 1.45; 95% confidence interval = 1.22-1.72). The excess in PM was not related to maternal or newborn physical characteristics that the authors observed. The risk of PM and its components in the Jewish localities was not associated with IP proximity. The association between residential proximity to the IP and excess in PM among only Bedouin newborns may be related to vulnerability caused by the nomadic nature of the society.  相似文献   
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Background

Resurgences of pertussis have occurred in several high-income countries, often linked to waning of immunity from acellular pertussis vaccines. The degree of waning observed has varied by study design and setting. In Ontario, pertussis has not shown a substantial resurgence in the past decade. The routine immunization schedule comprises three priming doses in infancy, toddler and pre-school doses, and an adolescent dose at 14–16?years of age.

Methods

We estimated pertussis vaccine effectiveness (VE) through a case-control study of 1335 cases statutorily reported to public health in Ontario and occurring between January 1, 2009 and March 31, 2015, compared with 5340 randomly selected population controls, frequency-matched by age, primary-care provider and year of diagnosis. Pertussis cases met provincial confirmed or probable case definitions. We used multivariable logistic regression to estimate crude and adjusted odds ratios (aOR).

Results

VE against pertussis was sustained between 92% (95% confidence interval (95%CI) 88–95%) in 2–3?year olds and 90% (95%CI: 80–95%) in 8–9?year olds, but fell rapidly to 49% (95%CI: 2–73%) in children 12–13?years of age. VE following the teenage booster given at 14–16?years in Ontario reached 76% (95%CI: 52–88%) in 14–16?year olds and 78% (95%CI: ?31 to 96%) in those 16–22?years old. For children who were up-to-date with the immunization schedule, VE declined from 87% (95%CI: 84–90%) during the first year to 74% (95%CI: 63–82%) after 8 or more years following their last dose of immunization.

Conclusions

VE is high during the first decade of life but then falls rapidly. Protection is not fully restored by the teenage booster. Our findings are consistent with the localized outbreaks we observe in high school children and underline the importance of additional policies to protect infants.  相似文献   
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Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis cases in the Ukraine are increasing. Pyrazinamide (PZA) is critically important for first- and second-line tuberculosis (TB) treatment regimes. However, PZA drug susceptibility testing is time consuming and technically challenging. The present study utilized Next-generation sequencing (NGS) to identify mutations in the pncA gene from clinical isolates and to assess the prevalence of pncA gene mutations in MDR/XDR-TB patients. Clinical isolates were inactivated in molecular transport media and shipped from Kharkiv, Ukraine, to San Antonio, TX. Whole-genome and targeted pncA gene sequencing was carried out using Illumina MiSeq instrumentation. Mutations were noted in 67 of 91 (74%) clinical isolates comprising substitutions, insertions, and deletions in the pncA coding and upstream promoter region. Of 45 mutation types, there were 11 novel, i.e., to date unknown, pncA mutations identified of which 3 were confirmed PZA resistant. Seven isolates contained mixed base mutations, whereas 4 harbored doubled mutations. Data reported here further support use of NGS for pncA gene characterization and may contribute in significant fashion to PZA therapy, especially in MDR- and XDR-TB patients.  相似文献   
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BACKGROUND:

Tuberculosis (TB) is a serious disease that is transmitted primarily by the airborne route. Effective disease control and outbreak management requires the timely diagnosis, isolation and treatment of infected individuals with active disease; contact tracing to identify secondary cases likely to benefit from treatment of latent infection; and laboratory identification or confirmation of epidemiologically linked cases. TB genotyping enables the comparison of Mycobacterium tuberculosis complex (MTBC) strains and the identification of cases that may or may not be linked. The increased availability of molecular methods for genotyping has allowed for greater discrimination of MTBC strains and greatly enhanced understanding of TB transmission patterns.

OBJECTIVE:

To improve TB surveillance and control in Ontario, the Public Health Laboratories of the Ontario Agency for Health Protection and Promotion has introduced the Ontario Universal Typing of Tuberculosis (OUT-TB) Surveillance Program.

METHODS:

The first isolate from every new TB case will be genotyped with two rapid molecular methods: spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem repeat typing. MTBC isolates with nonunique genotypes and, thus, potentially linked to other TB cases, will also be genotyped by IS6110 restriction fragment length polymorphism analysis.

CONCLUSION:

By providing TB control programs using these new genotyping tools, and using traditional and new case investigation methods (eg, social network analysis), this new program will provide a clearer picture of TB in Ontario, and permit more effective use of public health resources and improve disease control.  相似文献   
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