不孕症患者的子宫自然杀伤细胞、浆细胞与子宫内膜异位症的相关性

摘要 目的：探究不孕症患者的子宫自然杀伤细胞、浆细胞与子宫内膜异位症的相关性。方法：选择80例患有子宫内膜异位症的不孕症患者做为本研究的不孕症组和80例正常生育的健康女性做为本研究的健康组,对比分析两组患者人口学基本资料、子宫自然杀伤细胞（uNKs）、浆细胞（PC）水平、血清性激素水平、子宫内膜中血管内皮生长因子（VEGF）表达情况、免疫细胞水平。通过Person法分析不孕症患者的子宫自然杀伤细胞、浆细胞与子宫内膜异位症的相关性。结果：两组的BMI指数、流产史、吸烟史、饮酒史比较,差异有统计学意义（P<0.05）;不孕症组患者uNKs、抗苗勒氏管激素（AMH）和黄体生成素（LH）水平均显著高于健康组;PC、卵泡刺激素（FSH）、雌激素（Estrogen）和性激素结合球蛋白（SHBG）、VEGF阳性表达水平、CD4⁺、CD8⁺和CD4⁺/CD8⁺水平均显著低于健康组,差异有统计学意义（P<0.05）。另外,不孕症患者的uNKs与子宫内膜异位症存在显著的正相关关系（r=1.555,P<0.001）;PC与子宫内膜异位症存在显著的负相关关系（r=-3.778,P<0.001）。结论：不孕症患者的uNKs、PC参与不孕症的发生和发展过程,对女性子宫内膜异位症的诊断具有重要的参考意义。     

Turnover and trends in butterfly communities on two British tidal islands: stochastic influences and deterministic factors

Aim Community trends were investigated for two small islands and two local mainland butterfly communities within the UK over a period of 20–30 years. Location Hilbre Island off the Wirral Peninsula at 53.33° N, 3.10° W; Lindisfarne, an island off the Northumberland coast at 56.41° N, 1.48° W; Leighton Moss at 54.08° N, 2.26° W; Wyre Forest at 52.23° N, 2.14° W, UK. Methods Butterfly species data were collected on Hilbre and two mainland sites (Leighton Moss and Wyre Forest) from 1983 to 2006, and on Lindisfarne from 1977 to 2006, as part of the National Habitat Survey, the UK Butterfly Monitoring Scheme and ‘Butterflies for the New Millennium Atlas’ recording. Matrices of associations (Sokal and Michener’s matching coefficient S_SM; resemblance coefficient) were computed between years and subject to non‐metric multidimensional scaling (NMDS) and Mantel tests. The pattern of extinctions and colonizations at sites were examined, their heterogeneity tested by applying a Friedman test to fractional incidences for the same years. Regression analysis (multiple regression and logit regression) was used to relate butterfly numbers and incidences to climate variables, time and previous records. Results Significant community trends based on population counts and species’ incidences were found for all four sites. There was a significant climatic signal for Hilbre; although this was not apparent for the remaining sites, significant associations occurred between records for a number of species and climatic variables at all sites. Substantial turnover of species on the islands was inversely related to numbers of records for species but not to their conspicuousness to recorders. Main conclusions We argue that time trends are widespread in butterfly communities, even for relatively short periods; they are largely generated by stochastic influences rather than by more substantive factors such as climate change. Potential biases in surveying and recording history are shown to be unlikely. A clear climate signal was found only for the small Hilbre Island, for which there was also evidence for the significant influence of colonization capability of individual source species. We conclude that for many species, small islands will be sinks or pseudosinks and their ‘populations’ vulnerable to small changes in source–sink dynamics.     

Meta‐replication,sampling bias,and multi‐scale model selection: A case study on snow leopard (Panthera uncia) in western China

Replicated multiple scale species distribution models (SDMs) have become increasingly important to identify the correct variables determining species distribution and their influences on ecological responses. This study explores multi‐scale habitat relationships of the snow leopard (Panthera uncia) in two study areas on the Qinghai–Tibetan Plateau of western China. Our primary objectives were to evaluate the degree to which snow leopard habitat relationships, expressed by predictors, scales of response, and magnitude of effects, were consistent across study areas or locally landcape‐specific. We coupled univariate scale optimization and the maximum entropy algorithm to produce multivariate SDMs, inferring the relative suitability for the species by ensembling top performing models. We optimized the SDMs based on average omission rate across the top models and ensembles’ overlap with a simulated reference model. Comparison of SDMs in the two study areas highlighted landscape‐specific responses to limiting factors. These were dependent on the effects of the hydrological network, anthropogenic features, topographic complexity, and the heterogeneity of the landcover patch mosaic. Overall, even accounting for specific local differences, we found general landscape attributes associated with snow leopard ecological requirements, consisting of a positive association with uplands and ridges, aggregated low‐contrast landscapes, and large extents of grassy and herbaceous vegetation. As a means to evaluate the performance of two bias correction methods, we explored their effects on three datasets showing a range of bias intensities. The performance of corrections depends on the bias intensity; however, density kernels offered a reliable correction strategy under all circumstances. This study reveals the multi‐scale response of snow leopards to environmental attributes and confirms the role of meta‐replicated study designs for the identification of spatially varying limiting factors. Furthermore, this study makes important contributions to the ongoing discussion about the best approaches for sampling bias correction.     

Uterine Transplantation: Ethical Considerations within Middle Eastern Perspectives

The field of reproductive medicine witnessed a breakthrough in September 2014 with the first successful live birth post uterine transplantation. This success represents the culmination of decades' worth of research on infertility and reproductive medicine. This subject of infertility gathers special attention in the Middle East, as childbearing is given paramount importance in the family unit. And as with any new medical advancement, Middle Eastern people look to their religious authorities for guidance. This paper describes the various ethical quandaries related to uterine transplantation, from a perspective of the religious and societal factors that are unique to the Middle East, and embeds them within the conversation of its alternative solutions.     

Sampling strategy matters to accurately estimate response curves' parameters in species distribution models

Aim

Assessing how different sampling strategies affect the accuracy and precision of species response curves estimated by parametric species distribution models.

Major Taxa Studied

Virtual plant species.

Location

Abruzzo (Italy).

Time Period

Timeless (simulated data).

Methods

We simulated the occurrence of two virtual species with different ecology (generalist vs specialist) and distribution extent. We sampled their occurrence following different sampling strategies: random, stratified, systematic, topographic, uniform within the environmental space (hereafter, uniform) and close to roads. For each sampling design and species, we ran 500 simulations at increasing sampling efforts (total: 42,000 replicates). For each replicate, we fitted a binomial generalised linear model, extracted model coefficients for precipitation and temperature, and compared them with true coefficients from the known species' equation. We evaluated the quality of the estimated response curves by computing bias, variance and root mean squared error (RMSE). Additionally, we (i) assessed the impact of missing covariates on the performance of the sampling approaches and (ii) evaluated the effect of incompletely sampling the environmental space on the uniform approach.

Results

For the generalist species, we found the lowest RMSE when uniformly sampling the environmental space, while sampling occurrence data close to roads provided the worst performance. For the specialist species, all sampling designs showed comparable outcomes. Excluding important predictors similarly affected all sampling strategies. Sampling limited portions of the environmental space reduced the performance of the uniform approach, regardless of the portion surveyed.

Main Conclusions

Our results suggest that a proper estimate of the species response curve can be obtained when the choice of the sampling strategy is guided by the species' ecology. Overall, uniformly sampling the environmental space seems more efficient for species with wide environmental tolerances. The advantage of seeking the most appropriate sampling strategy vanishes when modelling species with narrow realised niches.     

Shrinkage and Pretest Nonparametric Estimation of Regression Parameters from Censored Data with Multiple Observations at Each Level of Covariate

A simple linear regression model is considered where the independent variable assumes only a finite number of values and the response variable is randomly right censored. However, the censoring distribution may depend on the covariate values. A class of noniterative estimators for the slope parameter, namely, the noniterative unrestricted estimator, noniterative restricted estimator and noniterative improved pretest estimator are proposed. The asymptotic bias and mean squared errors of the proposed estimators are derived and compared. The relative dominance picture of the estimators is investigated. A simulation study is also performed to asses the properties of the various estimators for small samples.     

The Effect of Mutation and Selection on Codon Adaptation in Escherichia coli Bacteriophage

Studying phage codon adaptation is important not only for understanding the process of translation elongation, but also for reengineering phages for medical and industrial purposes. To evaluate the effect of mutation and selection on phage codon usage, we developed an index to measure selection imposed by host translation machinery, based on the difference in codon usage between all host genes and highly expressed host genes. We developed linear and nonlinear models to estimate the C→T mutation bias in different phage lineages and to evaluate the relative effect of mutation and host selection on phage codon usage. C→T-biased mutations occur more frequently in single-stranded DNA (ssDNA) phages than in double-stranded DNA (dsDNA) phages and affect not only synonymous codon usage, but also nonsynonymous substitutions at second codon positions, especially in ssDNA phages. The host translation machinery affects codon adaptation in both dsDNA and ssDNA phages, with a stronger effect on dsDNA phages than on ssDNA phages. Strand asymmetry with the associated local variation in mutation bias can significantly interfere with codon adaptation in both dsDNA and ssDNA phages.     

Performance comparison of four exome capture systems for deep sequencing

Background

Recent developments in deep (next-generation) sequencing technologies are significantly impacting medical research. The global analysis of protein coding regions in genomes of interest by whole exome sequencing is a widely used application. Many technologies for exome capture are commercially available; here we compare the performance of four of them: NimbleGen’s SeqCap EZ v3.0, Agilent’s SureSelect v4.0, Illumina’s TruSeq Exome, and Illumina’s Nextera Exome, all applied to the same human tumor DNA sample.

Results

Each capture technology was evaluated for its coverage of different exome databases, target coverage efficiency, GC bias, sensitivity in single nucleotide variant detection, sensitivity in small indel detection, and technical reproducibility. In general, all technologies performed well; however, our data demonstrated small, but consistent differences between the four capture technologies. Illumina technologies cover more bases in coding and untranslated regions. Furthermore, whereas most of the technologies provide reduced coverage in regions with low or high GC content, the Nextera technology tends to bias towards target regions with high GC content.

Conclusions

We show key differences in performance between the four technologies. Our data should help researchers who are planning exome sequencing to select appropriate exome capture technology for their particular application.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-449) contains supplementary material, which is available to authorized users.