霍乱弧菌溶原性噬菌体CTXΦ的氯霉素抗性基因标记及诱导

目的　对携带霍乱毒素基因的溶原性噬菌体CTXΦ进行遗传标记 ,以深入研究CTXΦ对霍乱弧菌的转染机制。方法　将CTXΦ基因组中ctxAB的上下游同源序列连接到cat基因的两侧 ,然后通过自杀质粒介导的DNA同源重组技术将霍乱菌株N16 96 1染色体上CTXΦ基因组中的ctxAB基因缺失掉 ,替换以氯霉素抗性基因 ,对CTXΦ基因组进行遗传标记 ,然后用丝裂霉素C诱导这种经抗性基因标记的噬菌体 ,再利用它对古典型霍乱弧菌的转染检测活性。结果　获得了ctxAB缺失、带有cat遗传标记的重组菌株N Φc;诱导出的CTXΦc噬菌体颗粒成功感染了霍乱菌株 1119。结论　N Φc中的CTXΦ带有了氯霉素抗性标记 ,诱导出具有感染活性的CTXΦc可用于研究毒力基因的水平转移     

HIV-1 CRF55_01B毒株流行特征的研究进展

CRF55_01B是我国报道的HIV-1主要流行毒株之一,具有较为独特的流行病学和基因进化特征。近几年HIV-1分子流行病学监测发现CRF55_01B已经成为我国第五个主要流行HIV-1毒株。本研究从他的发现起源、流行情况、致病性和耐药性及参与的重组等方面进行综述,并讨论了与其流行密切相关的社会和生物学因素。     

2018—2021年北京市沙门菌血清型及喹诺酮类耐药表型和基因型分析

目的 分析2018—2021年北京市肠道门诊哨点医院分离到的沙门菌血清型及喹诺酮类药物耐药表型和耐药基因的流行情况。方法 采用玻片凝集法鉴定血清型;微量肉汤稀释法测定药物敏感性;全基因组测序数据通过与MLST和ResFinder数据库比对,查询ST型别和耐药基因。结果 228株沙门菌共检出42种血清型,51种ST型。其中肯塔基沙门菌、肠炎沙门菌和黄金海岸沙门菌等9种血清型比较常见。77株沙门菌（33.8%）对萘啶酸耐药;40株（17.5%）对环丙沙星和左氧氟沙星耐药;38株（16.7%）对吉米沙星耐药。不同血清型对喹诺酮类药物的耐药性不同。228株沙门菌共筛选出5种喹诺酮耐药基因:qnrS（23.7%）、aac(6’)-Ib-cr（8.3%）、qnrB（6.6%）、OqxAB（1.3%）和qepA（0.4%）;喹诺酮耐药决定区存在gyrA和parC的7种氨基酸突变:以parC:T57S（70.2%）最常见,其次是gyrA:D87N（14.9%）、parC:S80I（14.5%）、gyrA:S83F（14.5%）、gyrA:D87Y（7.9%）、gyrA:D87G（5.3%）和gyrA:S83Y（1.8%）。在组合突变中,以parC:S80I-gyrA:D87N-gyrA:S83F三突变,并伴随parC:T57S最多。耐药基因和突变位点在9种常见血清型中的检出率存在差异。结论 北京市沙门菌血清型及ST型种类繁多,携带喹诺酮耐药基因以qnrS、aac(6’)-Ib-cr和 qnrB为主,存在gyrA和parC多个位点突变并协同作用。应持续监测血清型和耐药性,以指导临床有针对性合理用药。     

放射性皮肤损伤机制的研究进展

皮肤是人体受到电离辐射时最先接触的器官,因其基底细胞层及毛细血管对射线很敏感,所以放射性皮肤损伤十分常见,急性放射性皮肤损伤常与表皮和真皮中的细胞改变和炎症有关,而皮肤的晚期损伤主要与辐射对血管影响有关。放射性皮肤损伤的临床表现为皮肤黏膜出现红斑、干性脱屑、湿性脱屑、溃疡,严重程度与射线种类、剂量等相关。目前,放射性皮肤损伤的潜在发生机制在很大程度上是未知的,辐射损伤后还未建立治疗的金标准,已知的放射性皮肤损伤的发生机制大致可分为3个途径：活性氧大量增加引发的氧化应激损伤、细胞因子被转录激活后引发的炎症、骨髓源性细胞引起的免疫反应。本文综述了放射性皮肤损伤发生机制的3大途径,为进一步研究放射性皮肤损伤的机制以及预防治疗提供参考。     

新运行实用量研究进展及对场所剂量监测的影响

在辐射防护领域,运行实用量用于估算防护量,是场所剂量监测中的重要量值。随着电离辐射粒子类型和能量范围的扩展,现行运行实用量在估算防护量的过程中出现局限。ICRU第95号报告提出了新的运行实用量体系,在定义方式和模体上与防护量相统一,在更广泛的粒子类型和能量范围中实现了对防护量的更好估算。本文重点关注新运行实用量体系在模体应用、转换系数更新、监测仪器的设计和校准等方面对场所剂量监测的影响。     

Regional Differences in the Prevalence of Anaemia and Associated Risk Factors among Infants Aged 0–23 Months in China: China Nutrition and Health Surveillance

Infantile anaemia has been a severe public health problem in China for decades. However, it is unclear whether there are regional differences in the prevalence of anaemia. In this study, we used data from the China Nutrition and Health Surveillance (CNHS) to assess the prevalence of anaemia and the risk factors associated with its prevalence in different regions. We included 9596 infants aged 0–23 months from the CNHS 2013 database. An infant was diagnosed with anaemia if he/she had a haemoglobin concentration of <110 g/L. We used multivariate logistic regression to investigate the potential risk factors associated with the development of anaemia. We found that anaemia was present in 2126 (22.15%) of the infants assessed. Approximately 95% of these cases were classified as mild anaemia. Based on the guidelines laid out by the World Health Organization, 5.5% and 43.6% of the surveillance sites were categorized as having severe and moderate epidemic levels of anaemia, respectively. The prevalence of infantile anaemia in Eastern, Central and Western China was 16.67%, 22.25% and 27.44%, respectively. Premature birth, low birth weight, breastfeeding and residence in Western China were significantly associated with higher odds of developing anaemia. Female sex and having mothers with high levels of education and maternal birth age >25 years were associated with lower odds of developing anaemia. In conclusion, we observed significant regional disparities in the prevalence of infantile anaemia in China. Western China had the highest prevalence of infantile anaemia, and rural regions showed a higher prevalence of anaemia than urban regions.     

Evaluation of Serum Zinc Status of Pregnant Women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) 2015

Objective: The purpose of this study was to evaluate serum zinc status of pregnant women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) in 2015–2016. Methods: A total of 7147 apparently healthy pregnant women were randomly selected in 302 national monitoring sites. Information on age, race, residence region, education, pregnancy, and family income per annum was collected, and the concentration of serum zinc was determined. The evaluation of serum zinc status was further performed according to the recommendations by the International Zinc Nutrition Consultative Group (IZiNCG). Results: The median concentration of serum zinc was 858.9 μg/L with an interquartile range (IQR) of 712.9 μg/L and 1048.9 μg/L, while the overall prevalence of zinc deficiency was 3.5% with a 95% confidence interval (CI) of 3.0% and 3.9%. Serum zinc status of pregnant women changed greatly in the different categories, particular in pregnancy and family income per annum (p < 0.05), but no significant difference was observed in the prevalence of zinc deficiency (p > 0.05). Conclusions: The lower prevalence of zinc deficiency generally indicated a better zinc status for pregnant women in the CACDNS in 2015–2016. However, a well-designed evaluation system of zinc status for pregnant women should be continually optimized and improved by inducing more parameters such as biochemical, dietary, or functional indicators.     

To What Extent Do Local Nursing Home Prescribing Patterns Relate to Psychotropic Prescribing in Assisted Living?

ObjectiveIn nursing homes (NHs), psychoactive medication use has received notable attention, but less is known about prescribing in assisted living (AL). This study examined how antipsychotic and antianxiety medication prescribing in AL compares with NHs.DesignObservational, cross-sectional AL data linked to publicly reported NH measures.Setting and ParticipantsRandom sample of 250 AL communities and the full sample of 3371 NHs in 7 states.MethodsWe calculated the percentage of residents receiving antipsychotics and antianxiety medications. For each AL community, we calculated the distance to NHs in the state. Linear models estimated the relationship between AL prescribing and that of the closest and farthest 5 NHs, adjusting for AL characteristics and state fixed effects.ResultsThe prescribing rate of potentially inappropriate antipsychotics (i.e., excluding for persons with recorded schizophrenia and Tourette syndrome) and of antianxiety medications (excluding for those on hospice) in AL was 15% and 21%, respectively. Unadjusted mean antipsychotic prescribing rates were nominally higher in AL than NHs (14.8% vs 14.6%; P = .056), whereas mean antianxiety prescribing was nominally lower in AL (21.2% vs 22.6%; P = .032). In adjusted analyses, AL rates of antipsychotic use were not associated with NH rates. However, being affiliated with an NH was associated with a lower rate of antipsychotic use [b = −0.03; 95% confidence interval (CI) −0.50 to −0.001; P = .043], whereas antianxiety rates were associated with neighboring NHs’ prescribing rates (b = 0.43; 95% CI 0.16–0.70; P = .002).Conclusions and ImplicationsThis study suggests reducing antipsychotic medication use in NHs may influence AL practices in a way not accounted for by local NH patterns. And, because antianxiety medications have not been the focus of national campaigns, they may be more subject to local prescribing behaviors. It seems advantageous to consider prescribing in AL when efforts are implemented to change NH prescribing, as there seems to be related influence whether by affiliation or region.     

Defining the Core Skills and Activities of the Attending Physician in Post-Acute and Long-Term Care

The American Board of Post-Acute and Long-Term Care Medicine (ABPLM) contracted with a psychometric firm to perform a 3-phase Job Analysis following best practices. Literature was reviewed, a task force of subject matter experts was convened, a survey was developed and sent via Survey Monkey to attending physicians practicing in post-acute and long-term care settings (PALTC). The task force refined a comprehensive list of the tasks, knowledge, and medical knowledge needed in the role of attending physician in PALTC. These items were written as statements and edited until consensus was reached on their accuracy, conciseness, and lack of overlap. Task statements described distinct, identifiable, and specific practice-related activities relevant across multiple care settings. Knowledge statements described previously acquired information considered necessary to effectively perform such tasks. The survey consisted of 260 items, including 21 demographic questions, 115 task statements, 73 knowledge statements, and 72 medical knowledge statements. The survey was disseminated via e-mail invitations to Society for Post-Acute and Long-Term Care (AMDA) members and through an online link available through ABPLM’s website. A total of 389 respondents participated. Survey data were analyzed with statistical analysis software SPSS. For each task and knowledge statement, an Overall Task Rating and Knowledge Rating were developed by combining the importance rating weighted at 65% and (for task) the frequency rating or (for knowledge) the cognitive level weighted at 35%. One task statement and 1 medical knowledge statement had a mean importance rating lower than 2.5 and were dropped from further review, resulting in a final count of 114 task, 73 knowledge, and 71 medical knowledge statements (258 total). The results of this Job Analysis highlight the unique and specific nature of medical care provided by attending physicians across a range of PALTC settings. These findings lay a foundation for Focused Practice Designation or Subspecialty in PALTC and changes in practice and policy.