藏汉民族线粒体基因组全序列的比较研究

目的 以藏汉民族线粒体基因组全序列为基础,进行Haplogroup构建和系统发生分析,在全序列水平上比较核苷酸的变异,阐释可能的变异机制和蕴含的生物学意义.方法 采用Applied Biosystems 3730DNA自动测序仪分别对40名藏族和50名汉族的标本进行线粒体DNA序列测定,应用phredPhrap 16.0软件进行全序列拼接,并以rCRS(revised Cambridge Reference Sequence)为标准与测定序列进行比对分析;根据MTTO-MAP的标准,通过Network方法进行Haplogroup构建和系统发生的分析,并结合其它方法对产生的数据进行深入解读.结果 数据分析结果显示:在系统发生上,藏汉民族90个线粒体DNA序列归类到13个Haplogroups,除M9以外,其它各Haplogroup出现频率之间比较差异无统计学意义;通过两个民族的线粒体DNA全序列比对,发现21个分布频率有统计学意义的变异位点,其中的5个为新变异位点;另外,对D-Loop区的5个突变位点进行了单倍型构建,90个标本可分为2种Supertype,发现在藏汉民族之间Supertypel和Supertype 2的分布频率均有统计学意义.结论 藏汉民族在种族起源和系统发生上具有较近的母系遗传关系;在全序列有统计学意义的位点究竟是适应性或者中性选择,抑或是一种病理性突变尚需深入的探讨.     

The components of the sodium efflux in frog muscle

1. In normal Ringer solution containing 2.5 mM-K only 37% of the efflux of labelled sodium from a freshly dissected frog muscle is blocked by treatment with ouabain; in sodium-loaded muscles the ouabain-sensitive fraction of the efflux increases to 75%.2. Under all conditions, the ouabain-insensitive component of the sodium efflux is markedly reduced if the sodium in the external medium is replaced by lithium; at least in sodium-loaded muscles, the ouabain-sensitive component is increased in lithium Ringer.3. Only the ouabain-sensitive component of the efflux is affected by the external potassium concentration.4. In the presence of 2.5 mM-K the sodium influx in a freshly dissected muscle is not significantly altered by ouabain, but in a K-free medium the influx and the efflux are both reduced by nearly 20%.5. The sodium efflux can therefore be regarded as consisting of (1) a sodium-potassium coupled component that is blocked by ouabain and involves a sodium-sodium exchange in the absence of external potassium, and (2) a potassium-insensitive component that is unaffected by ouabain and tends to reach saturation at relatively lower internal sodium concentrations.6. The evidence is considered for attributing component (1) to an efflux of sodium from the sarcoplasm proper, and component (2) to an efflux from the sarcoplasmic reticulum. Although such an interpretation is consistent with many of the observations, a definite identification of the possible sodium compartments in frog muscle cannot yet be made.     

Mycoplasmacidal Activity of Peroxidase-H2O2-Halide Systems

A mycoplasmacidal system consisting of myeloperoxidase (MPO)-containing granules, H(2)O(2), and a halide is described. In all parameters measured, it appears to be identical to the MPO-H(2)O(2)-halide bactericidal system previously reported. It has a pH optimum of approximately 5.5 and an optimal MPO:H(2)O(2) ratio of 1:25. The halide requirement can be satisfied by either chloride or iodide. Through the use of taurine or horseradish peroxidase substitution, chloride-mediated killing can be distinguished from iodide-mediated killing. The relationship of this mycoplasmacidal system to other mycoplasmacidal systems and to host surveillance of mycoplasma is discussed.     

Evaluation of Job Strain of Family Physicians in COVID-19 Pandemic Period- An Example from Turkey

Journal of Community Health - The purpose of this study was to evaluate family physicians’ job strain during the Covid-19 pandemic and determine the effective factors. The study was carried...     

血管粘弹性对法推拿作用下血管切应力的影响

目的研究血管粘弹性对脉动血流在(扌衮)法推拿作用下切应力的影响.方法建立具有局部轴向运动狭窄的粘弹性血管中脉动血流模型.设血液为牛顿流体,血管壁为线性粘弹体.在(扌衮)法推拿作用下血管受水平外力作用形成轴向运动缓变狭窄,血流遵循线化Navier-stokes方程.结果粘弹性血管在(扌衮)法作用下,距离血管入口z=31 cm处的平均切应力、最大切应力和瞬时切应力以及最大狭窄下游血管段最大切应力随着血管粘性系数和手法频率的改变而有较大变化.结论(扌衮)法推拿作用下粘弹性血管的血管切应力有显著变化,这与中医推拿的活血化淤相吻合.     

松质骨中两种纵波的传播特性分析

基于松质骨的层状模型，利用Schoenberg理论分析了松质骨中两种纵波(快纵波和慢纵波)的传播特性；并在理论和实验上详细分析了骨小梁方向与传播方向间的夹角对松质骨中快纵波和慢纵波传播特性的影响。分析结果表明，当超声波平行于骨小梁入射时，松质骨中两种纵波都传播，入射角度在60度附近时，松质骨中两种纵波的相速度曲线有一个转折点，入射角度在60度以上，角度越大时，骨髓和骨小梁耦合得越紧，因此阻止了慢纵波的传播，而只有快纵波传播。     

A critical assessment of published guidelines and other decision-support systems for the antibiotic treatment of community-acquired respiratory tract infections

Guidelines are an important means by which professional associations and governments have sought to improve the quality and cost-effectiveness of disease management for infectious diseases. Prescribing of initial antibiotic therapy for community-acquired respiratory tract infections (RTIs) is primarily empiric and physicians may often have a limited appreciation of bacterial resistance. Recent guidelines for managing RTIs have adopted a more evidence-based approach. This process has highlighted important gaps in the existing knowledge base, e.g. concerning the impact of resistance on the effectiveness of oral antibiotics for outpatient community-acquired pneumonia and the level of resistance that should prompt a change in empiric prescribing. In upper RTIs, the challenge is to identify patients in whom antibiotic therapy is warranted. Concentrated, sustained efforts are needed to secure physicians' use of guidelines. The information should be distilled into a simple format available at the point of prescribing and supported by other behavioral change techniques (e.g. educational outreach visits). Advances in information technology offer the promise of more dynamic, computer-assisted forms of guidance. Thus, RTI prescribing guidelines and other prescribing support systems should help control bacterial resistance in the community. However, their effect on resistance patterns is largely unknown and there is an urgent need for collaborative research in this area. Rapid, cost-effective diagnostic techniques are also required and new antibiotics will continue to have a role in disease management.     

THE EFFECT OF PROSTAGLANDIN E1 ON PULMONARYBLOOD FLOW AFTER RETROGRADE FLUSH ANDCOLD STORAGE OF LUNGS

ReSllm6 Objectif Nos studes Precedentes out montrd une panne fonCtion de la greffe pulmonaire traitde Prdalablementper perfusion forcde retrograde et un stockage d froid inns ~. L' etude Prdsente a pour but de determiner l' effet de ~ surlefiot mngUin du poumon trait4 Prdalablement per perfusion retrograde forcde et un stockage d froid. met~. 12poumons donneurs canins out ate trait4s per perfusion r4tFograde de solution UW. Chez 6 animaux du grouch A, 250ng furent injectes dans l' artrdre…     

SOX5: Lamb–Shaffer syndrome—A case series further expanding the phenotypic spectrum

To delineate further the clinical phenotype of Lamb–Shaffer Syndrome (LSS) 16 unpublished patients with heterozygous variation in SOX5 were identified either through the UK Decipher database or the study team was contacted by clinicians directly. Clinical phenotyping tables were completed for each patient by their responsible clinical geneticist. Photos and clinical features were compared to assess key phenotypes and genotype–phenotype correlation. We report 16 SOX5 variants all of which meet American College of Medical Genetics/Association for Clinical Genomic Science ACMG/ACGS criteria class IV or V. 7/16 have intragenic deletions of SOX5 and 9/16 have single nucleotide variants (including both truncating and missense variants). The cohort includes two sets of monozygotic twins and parental gonadal mosaicism is noted in one family. This cohort of 16 patients is compared with the 71 previously reported cases and corroborates previous phenotypic findings. As expected, the most common findings include global developmental delay with prominent speech delay, mild to moderate intellectual disability, behavioral abnormalities and sometimes subtle characteristic facial features. We expand in more detail on the behavioral phenotype and observe that there is a greater tendency toward lower growth parameters and microcephaly in patients with single nucleotide variants. This cohort provides further evidence of gonadal mosaicism in SOX5 variants; this should be considered when providing genetic counseling for couples with one affected child and an apparently de novo variant.