早产儿喂养不耐受肠道菌群多样性研究

目的：采用变性梯度凝胶电泳聚合酶链反应（ PCR－DGGE）技术从微生物生态学的角度分析比较喂养不耐受（ FI）与健康早产儿肠道细菌群落结构的多样性及相似性。方法以2013年11月至2014年9月在第四军医大学附属唐都医院儿科新生儿病房诊断为FI的早产儿为FI组。选择与FI组胎龄、日龄、出生体重相匹配的非FI早产儿作为对照组。采集出现FI时和同时间段对照组的粪便标本,进行16SrDNAV3区扩增和变性梯度凝胶电泳（DGGE）,从而分析比较两组间肠道菌群多样性指数及相似性。结果细菌多样性检测显示FI组的肠道菌群多样性指数香农－维纳指数（H）、丰度（S）、均衡度指数（E）和辛普森多样性指数（D）均低于对照组（均P＜0．05）;相似性矩阵图及聚类分析结果显示组内菌群相似性较组间高（P＜0．05）;PCA结果同聚类分析一致。结论肠道微生物群落多样性的改变及群落结构紊乱可能是引起早产儿FI的重要因素。     

This child can: participation in sport for children with vision impairment

All children benefit from access to sports, exercise and leisure. It is important not just for physical health, but also for emotional wellbeing and social connectivity. Vision impairment refers to a bilateral uncorrectable reduction in vision and is experienced by 1 in 1000 young people under the age of 16 in the UK. Many children with vision impairment experience barriers in their access to sport and exercise, and a traditional medical model of disability would associate these barriers with the pathology of ophthalmological disease. The social model of disability favours consideration of environmental, behavioural, organisational and attitudinal factors in considering barriers to inclusion. Considering clinical, developmental, social and environmental factors, we can explore the opportunities available to maximise participation in sport by children with vision impairment.     

Human mitochondrial DNA variation in Southern Italy

Background: Since prehistoric times Southern Italy has been a cultural crossroads of the Mediterranean basin. Genetic data on the peoples of Basilicata and Calabria are scarce and, particularly, no records on mtDNA variability have been published.

Aim: In this study mtDNA haplotypes of populations from Basilicata, Calabria and Sicily are compared with those of other Italian and Mediterranean populations, so as to investigate their genetic relationships.

Subjects and methods: A total of 341 individuals was analysed for mtDNA in order to provide their classification into haplogroups. Multivariate analysis was used to compare the studied populations with other Mediterranean samples; median-joining network analysis was applied to observe the relationship between the major lineages of the Southern Italians.

Results: The haplogroup distribution in the Southern Italian samples falls within the typical pattern of mtDNA variability of Western Eurasia. The comparison with other Mediterranean countries showed a substantial homogeneity of the area, which is probably related to the historic contact through the Mediterranean Sea.

Conclusion: The mtDNA analysis demonstrated that Southern Italy displays a typical pattern of Mediterranean basin variability, even though it appears plausible that Southern Italy was less affected by the effects of the Late Glacial Maximum, which reduced genetic diversity in Europe.     

Influence of knowledge,training and experience of observers on the reliability of anthropometric measurements in children

Objective : To elucidate the impact of the observer's level of technical knowledge, training and experience with measuring height and triceps skinfold thickness on the reliability of these measurements in children. Despite of instructions and encouraging careful measurements, these factors may significantly affect measurements and lead to interpretation difficulties, especially of short term growth data. Subjects and methods : A cross-sectional study was designed in which 18 children, aged 2-7 years, were measured in duplo by 12 observers with different backgrounds and levels of experience, protocol knowledge and protocol training. The main outcome measures, precision and accuracy, were expressed as technical error of measurement (TEM) and average bias (AB) in comparison with an expert anthropometrist. Results : As expected, the best educated and most experienced observers scored the best precision and accuracy. By ranking analysis and multiple regressions we learned that precision and accuracy in measuring height and triceps skinfold thickness are mainly predicted by allround knowledge of the measurement protocol (p< 0.05) and the years of experience (p< 0.05). A practical training course of only a few hours does not seem to improve reliability significantly. Conclusion : To get a more reliable insight in growth of a child it is important to be aware of the influence on measurement outcome values of protocol knowledge and years of experience. Growth studies should use detailed anthropometric standardization protocols and train people to acquire better insight into these protocols.     

Comparison of Junctional Diversity in the Neonatal and Adult Immunoglobulin Repertoires

Junctional diversity in immunoglobulin (Ig) from an adult mouse contributes significantly to the size of the final Ig repertoire. In adult pre-B cells, N region addition and deletion of nucleotides form coding regions produces very heterogenous CDR3 sequences. In contrast, Ig from fetal and newborn mice show very restricted junctional diversity. The reasons for this are: (a) the lack of N regions; and (b) the predominance of certain junctional sequences. These common junctional sequences all appear to occur by targeted rearrangement to short stretches of sequence homology near the ends of the segments to be joined. Targeted rearrangement may play a role in the over-expression of certain Vh genes early in ontogeny. These non-random junctional sequences in the neonate will reproducibly create certain Ig, for example, the dominant T15 anti-PC antibodies. Thus the immune system first creates a small repertoire of predictable Ig sequences. To the extent that these Ig are expressed in long-lived B cells, these early Ig sequences may persist in the adult. Superimposed upon this early repertoire is an enormously diverse adult Ig repertoire.     

Activity and bacterial diversity of snow around Russian Antarctic stations

The diversity and temporal dynamics of bacterial communities in pristine snow around two Russian Antarctic stations was investigated. Taxonomic analysis of rDNA libraries revealed that snow communities were dominated by bacteria from a small number of operational taxonomic units (OTUs) that underwent dramatic swings in abundance between the 54th (2008–2009) and 55th (2009–2010) Russian Antarctic expeditions. Moreover, analysis of the 55th expedition samples indicated that there was very little, if any, correspondence in abundance of clones belonging to the same OTU present in rDNA and rRNA libraries. The latter result suggests that most rDNA clones originate from bacteria that are not alive and/or active and may have been deposited on the snow surface from the atmosphere. In contrast, clones most abundant in rRNA libraries (mostly belonging to Variovorax, Janthinobacterium, Pseudomonas, and Sphingomonas genera) may be considered as endogenous Antarctic snow inhabitants.     

云南香格里拉山地自然风景区蚤类多样性的研究

蚤类是传播多种自然疫源性疾病的重要媒介昆虫,人类在自然风景区户外活动时存在被其叮咬而感染虫媒传染病的风险。为了解云南香格里拉县主要山地自然风景区蚤类的多样性状况,2005年秋,我们选择了虎跳峡、哈巴雪山、白水台、千湖山和红山5个不同海拔高度的自然风景区为调查研究的空间范围,应用夹线法捕小型兽类并收集其体表寄生蚤类进行调查取样,对蚤类多样性、群落相似性和蚤类与宿主关系进行了测度和比较研究。结果显示：（1）共捕获蚤类633只,隶属4科19属34种,其中发现云南省1新纪录属及种（喜马狭蚤Stenoponiahimalayana）,当地新纪录蚤类10种（亚种）,显示当地山地自然风景区内蚤种丰富;（2）红山和千湖山景区蚤种丰富度较高（各18种）和物种多样性也较高（分别为2．50和2．18）,而虎跳峡景区捕获的蚤类丰富度（8种）和物种多样性指数（1．79）最低,蚤类物种丰富度和Shannon—Wienor指数均随着景区海拔的升高呈递增趋势;（3）综合分析Jaccard指数和聚类分析的结果,5个风景区被划为虎跳峡-哈巴雪山-白水台、千湖山-红山两个类型,相对植被和水湿条件而言,人为干扰或是导致这一结果更重要的原因;（4）5个自然风景区蚤类群落与宿主群落丰富度的Spearman秩相关系数为0．24,Shannon—Wiener指数的Spearman秩相关系数为0．60,显示5个景区的蚤类多样性与宿主多样性无相关。     

The High Diversity of MRSA Clones Detected in a University Hospital in Istanbul

Background: To characterize the methicillin-resistant Staphylococcus aureus (MRSA) clones present in Istanbul, 102 MRSA isolates collected during a 5-year period at the Istanbul Medical Faculty Hospital were characterized using microarray analysis and phenotypic resistance profiles.Methods: Resistance to methicillin was detected with a cefoxitin disk diffusion assay and confirmed with a MRSA-agar and MRSA detection kit. Antimicrobial susceptibility testing was performed by a disk diffusion assay and interpreted according to the 2012 guidelines of the Antibiogram Committee of the French Society for Microbiology. Decreased susceptibility to glycopeptides was confirmed using the population analysis profile-area under the curve (PAP-AUC) method. The presence of the mecA gene was detected by polymerase chain reaction. Bacterial DNA was extracted according to the manufacturer''s recommended protocol using commercial extraction kits. Strains were extensively characterized using the DNA microarray.Results: Isolates were grouped into six clonal complexes. The most frequently detected clone was the Vienna/Hungarian/Brazilian clone (ST239-MRSA-III), which accounted for 53.9% of the isolates. These isolates were resistant to multiple antibiotics, particularly penicillin, tetracycline, rifampicin, kanamycin, tobramycin, gentamicin, levofloxacin, erythromycin, lincomycin and fosfomycin. Furthermore, three isolates were detected by population analysis profile as heterogeneous vancomycin-intermediate S. aureus (hVISA). The UK-EMRSA-15 clone (ST22-MRSA-IV PVL negative) was detected in 9.8% of the isolates and was mainly susceptible to all anti-staphylococcal antibiotics. Seven isolates (6.9%) were positive for PVL genes and were assigned to the CC80-MRSA-IV clone (European CA-MRSA clone, three isolates), ST8-MRSA-IV clone (USA300 clone, two isolates, one ACME-positive) or ST22-MRSA-IV clone (“Regensburg EMRSA” clone, two isolates). All other clones were detected in one to six isolates and corresponded to well-known clones (e.g., Pediatric clone, Dublin EMRSA clone, WA MRSA-54/63, WA MRSA-1/57).Conclusions: This work highlighted both the high prevalence of ST239-MRSA-III clone and the large diversity of the other MRSA clones detected in a university hospital in Istanbul.