Validation of the rat model of cryptogenic infantile spasms

Purpose: To determine whether a new model of cryptogenic infantile spasms consisting of prenatal priming with betamethasone and postnatal trigger of spasms by N‐methyl‐d ‐aspartate (NMDA) responds to chronic adrenocorticotropic hormone (ACTH) treatment, and has electroencephalography (EEG) signature, efficacy of treatments, and behavioral impairments similar to those in human infantile spasms. Methods: Rats prenatally primed with betamethasone on gestational day 15 were used. Spasms were triggered with NMDA between postnatal days (P) 10 and 15 in a single session or in multiple sessions in one subject. The expression of spasms was compared to prenatally saline‐injected controls. Effects of relevant treatments (ACTH, vigabatrin, methylprednisolone, rapamycin) were determined in betamethasone‐primed rats. In the rats after spasms, behavioral evaluation was performed in the open field and elevated plus maze on P20–22. Key Findings: NMDA at P10–15 (the rat “infant” period) triggers the spasms significantly earlier and in greater numbers in the prenatal betamethasone‐exposed brain compared to controls. Similar to human condition, the spasms occur in clusters. Repeated trigger of spasms is associated with ictal EEG electrodecrements and interictal large‐amplitude waves, a possible rat variant of hypsarrhythmia. Chronic ACTH treatment in a randomized experiment, and chronic pretreatment with methylprednisolone significantly suppress the number of spasms similar to the human condition. Pretreatment with vigabatrin, but not rapamycin, suppressed the spasms. Significant behavioral changes occurred following multiple bouts of spasms. Significance: The model of infantile spasms has remarkable similarities with the human condition in semiology, EEG, pharmacologic response, and long‐term outcome. Therefore, the model can be used to search for novel and more effective treatments for infantile spasms.     

Identification of homogeneous genetic architecture of multiple genetically correlated traits by block clustering of genome‐wide associations

Genome‐wide association studies (GWAS) using high‐density genotyping platforms offer an unbiased strategy to identify new candidate genes for osteoporosis. It is imperative to be able to clearly distinguish signal from noise by focusing on the best phenotype in a genetic study. We performed GWAS of multiple phenotypes associated with fractures [bone mineral density (BMD), bone quantitative ultrasound (QUS), bone geometry, and muscle mass] with approximately 433,000 single‐nucleotide polymorphisms (SNPs) and created a database of resulting associations. We performed analysis of GWAS data from 23 phenotypes by a novel modification of a block clustering algorithm followed by gene‐set enrichment analysis. A data matrix of standardized regression coefficients was partitioned along both axes—SNPs and phenotypes. Each partition represents a distinct cluster of SNPs that have similar effects over a particular set of phenotypes. Application of this method to our data shows several SNP‐phenotype connections. We found a strong cluster of association coefficients of high magnitude for 10 traits (BMD at several skeletal sites, ultrasound measures, cross‐sectional bone area, and section modulus of femoral neck and shaft). These clustered traits were highly genetically correlated. Gene‐set enrichment analyses indicated the augmentation of genes that cluster with the 10 osteoporosis‐related traits in pathways such as aldosterone signaling in epithelial cells, role of osteoblasts, osteoclasts, and chondrocytes in rheumatoid arthritis, and Parkinson signaling. In addition to several known candidate genes, we also identified PRKCH and SCNN1B as potential candidate genes for multiple bone traits. In conclusion, our mining of GWAS results revealed the similarity of association results between bone strength phenotypes that may be attributed to pleiotropic effects of genes. This knowledge may prove helpful in identifying novel genes and pathways that underlie several correlated phenotypes, as well as in deciphering genetic and phenotypic modularity underlying osteoporosis risk. © 2011 American Society for Bone and Mineral Research.     

新农村建设背景下青年农民心理和谐现状的聚类分析

目的探讨新农村建设背景下青年农民心理和谐的现状。方法采用目的性取样的方法,以云南省和河南省1275名农民为被试,用心理和谐量表进行测量。结果 1性别、民族、省份和农民类型是影响青年农民心理和谐的重要因素;2通过聚类分析将青年农民的心理和谐状况分为3类,3类农民的数量存在显著的统计学差异(χ2=169.416,P0.001),只有32.47%的青年农民的心理和谐程度较好。结论中国青年农民心理和谐平均得分为3.89分,已接近4分,这是政府、社会及个人多方努力的结果,但状况参差不齐,尚未达到非常和谐的程度,应继续努力提高其心理和谐水平。     

Techniques for clustering gene expression data

Many clustering techniques have been proposed for the analysis of gene expression data obtained from microarray experiments. However, choice of suitable method(s) for a given experimental dataset is not straightforward. Common approaches do not translate well and fail to take account of the data profile. This review paper surveys state of the art applications which recognise these limitations and addresses them. As such, it provides a framework for the evaluation of clustering in gene expression analyses. The nature of microarray data is discussed briefly. Selected examples are presented for clustering methods considered.     

通州市农村人群代谢综合征的因子分析

目的探讨代谢综合征（MS）患病率的性别差异,分析不同性别代谢综合征各组分的聚集特征。方法有效样本20502名,男性6997人,女性13505人,分别对其代谢综合征的组分f血压、体质指数（BMI）、腰围（WC）、血清胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL—C）、空腹血糖（FPG）1进行因子分析。结果代谢综合征患者3434人,粗患病率为16．75％,其中男性为11．52％,女性为19．46％,女性粗患病率显著高于男性（P〈0．001）;标化率为10．74％,其中男性为10．35％,女性为11．16％。男性WC、收缩压（SBP）、舒张压（DBP）高于女性,女性BMI、TC、HDL—C、FPG高于男性,差异均有统计学意义（P〈0．05）,男女性之间TG差异无统计学意义。男、女因子分析分别都提取了4个主要因子,因子方差累计贡献率分别为80．898％,78．347％。男女代谢综合征组分的聚集性基本相同但也存在差异,肥胖因子处于核心地位,血压因子为重要且独立的因子,其次是血脂紊乱因子、血糖因子。结论代谢综合征是多因素综合作用的结果,该调查研究显示肥胖因子、血压因子作用较强,男女代谢综合征的因子构成存在差异。     

Deriving reference values for nerve conduction studies from existing data using mixture model clustering

Objective: to obtain locally valid reference values (RVs) from existing nerve conduction study (NCS) data.Methods: we used age, sex, height and limb temperature-based mixture model clustering (MMC) to identify normal and abnormal measurements on NCS data from two university hospitals. We compared MMC-derived RVs to published data; examined the effect of using different variables; validated MMC-derived RVs using independent data from 26 healthy control subjects and investigated their clinical applicability for the diagnosis of polyneuropathy.Results: MMC-derived RVs were similar to published RVs. Clustering can be achieved using only sex and age as variables. MMC is likely to yield reliable results with fewer abnormal than normal measurements and when the total number of measurements is at least 300. Measurements from healthy controls fell within the 95% MMC-derived prediction interval in 97.4% of cases.Conclusions: MMC can be used to obtain RVs from existing data, providing a locally valid, accurate reflection of the (ab)normality of an NCS result.Significance: MMC can be used to generate locally valid RVs for any test for which sufficient data are available.¹     

1 052例新型冠状病毒肺炎聚集性病例流行病学特征分析

目的 了解新型冠状病毒肺炎聚集性病例的流行病学特征,探讨家庭因素以及集体活动等对本病传播的影响。方法 于2020年1月19日至2月25日每日从中国6个省份公布聚集性病例的36个地市官方平台收集积聚性病例数量、个案信息,采用描述性统计方法、χ²检验以及曲线拟合对聚集性病例的流行病学特征进行分析。结果 共收集聚集性病例366起1 052例,家庭聚集性病例占86.9%（914/1 052）;1 046例有性别信息的聚集性病例中,男性513例（49.0%）,女性533例（51.0%）;病例以18～59岁青壮年为主,占68.5%（711/1 038）。在366起聚集性疫情中,有47.0%（172/366）聚集性疫情的首例确诊病例曾有武汉市或湖北省旅居史。1月19日至2月3日,首例确诊病例有武汉市或湖北省旅居史占66.5%;2月4-25日聚集性病例首例确诊病例有武汉市或湖北省旅居史仅占18.2%。一代病例与二代病例发病时间间隔M为5（2～8）d,首发病例的发病—确诊时间间隔M为6（3～9）d,续发病例的发病—确诊时间间隔M为5（3～8） d。结论 聚集性疫情在武汉市和湖北省以外多地市普遍出现,家庭密切接触是造成家庭内传播的主要原因之一。2月4日后聚集性病例以当地一代或二代以后的病例传播为主,确诊时间缩短。     

Computer aided identification of eugonic gram-negative bacilli: Clustering for bacteriological screening

A system based on pattern recognition in terms of operationally meaningful criteria has been designed for the identification of eugonic gram-negative bacilli. It includes the selection of a battery of tests to be used as a screening. The results of these tests place each isolate in any one of a number of clusters. A second set of tests is used to identify the isolate as one of the species in the cluster. The system can identify most common species economically and can be used in clinical laboratories not equipped with computers.     

一个基于内容检索的医学图像数据库

介绍了一个基于图像内容检索的医学图像数据库系统。分别讨论了用于图像内容检索的颜色、纹理和形状特征以及在此特征集下的图像相似性度量 ;介绍了数据库的组织及该系统的界面