A sea urchin genome project: sequence scan, virtual map, and additional resources

Results of a first-stage Sea Urchin Genome Project are summarized here. The species chosen was Strongylocentrotus purpuratus, a research model of major importance in developmental and molecular biology. A virtual map of the genome was constructed by sequencing the ends of 76,020 bacterial artificial chromosome (BAC) recombinants (average length, 125 kb). The BAC-end sequence tag connectors (STCs) occur an average of 10 kb apart, and, together with restriction digest patterns recorded for the same BAC clones, they provide immediate access to contigs of several hundred kilobases surrounding any gene of interest. The STCs survey >5% of the genome and provide the estimate that this genome contains approximately 27,350 protein-coding genes. The frequency distribution and canonical sequences of all middle and highly repetitive sequence families in the genome were obtained from the STCs as well. The 500-kb Hox gene complex of this species is being sequenced in its entirety. In addition, arrayed cDNA libraries of >10(5) clones each were constructed from every major stage of embryogenesis, several individual cell types, and adult tissues and are available to the community. The accumulated STC data and an expanding expressed sequence tag database (at present including >12, 000 sequences) have been reported to GenBank and are accessible on public web sites.     

FEELING SAFE: INTERGENERATIONAL CONNECTIONS AND NEIGHBORHOOD DISORGANIZATION AMONG URBAN AND RURAL AFRICAN AMERICAN YOUTH

Neighborhood disorganization and the perception of neighborhood disorganization are linked to several adverse outcomes for youth. Disorganized communities often lack the social structures to promote well‐being, maintain social control, and provide an environment in which youth feel safe. Intergenerational connections, similar to cultural attributes of collectiveness and extended family found among people of African ancestry, was expected to be linked to less perceived neighborhood disorganization. Neighborhood type, rural versus urban, was also investigated as a moderator of the relationship between intergenerational connections and perceived neighborhood disorganization. Participants were 564 elementary, middle, and high school students who were recruited from urban and rural schools in a mid‐Atlantic region of the United States. Students completed measures of Intergenerational Connections and Neighborhood Disorganization along with demographic items. The findings indicated that higher levels of intergenerational connections were associated with perceptions of less disorganized neighborhoods. A significant interaction was found between neighborhood type and intergenerational connections. Intergenerational connections lowered perceptions of disorganization in urban neighborhoods such that youth in neighborhoods with high intergenerational connections reported lower disorganization than those in areas of low intergenerational connections. This effect was not found for youth in rural neighborhoods. Benefits and methods for increasing intergenerational connections among African American youth are discussed.     

Corticobasal and ataxia syndromes widen the spectrum of C9ORF72 hexanucleotide expansion disease

Recently, a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 was reported as the cause of chromosome 9p21‐linked frontotemporal dementia‐amyotrophic lateral sclerosis (FTD‐ALS). We here report the prevalence of the expansion in a hospital‐based cohort and associated clinical features indicating a wider clinical spectrum of C9ORF72 disease than previously described. We studied 280 patients previously screened for mutations in genes involved in early onset autosomal dominant inherited dementia disorders. A repeat‐primed polymerase chain reaction amplification assay was used to identify pathogenic GGGGCC expansions. As a potential modifier, confirmed cases were further investigated for abnormal CAG expansions in ATXN2. A pathogenic GGGGCC expansion was identified in a total of 14 probands. Three of these presented with atypical clinical features and were previously diagnosed with clinical olivopontocerebellar degeneration (OPCD), atypical Parkinsonian syndrome (APS) and a corticobasal syndrome (CBS). Further, the pathogenic expansion was identified in six FTD patients, four patients with FTD‐ALS and one ALS patient. All confirmed cases had normal ATXN2 repeat sizes. Our study widens the clinical spectrum of C9ORF72related disease and confirms the hexanucleotide expansion as a prevalent cause of FTD‐ALS disorders. There was no indication of a modifying effect of the ATXN2 gene.     

胃泌素对胃癌细胞SGC7901 Reg Ⅰ基因转录因子的效应

目的 探讨胃泌素对胃癌细胞SGC7901 Reg Ⅰ(Reg Ⅰ)基因转录因子的效应.方法 应用巢式PCR技术从胃癌细胞SGC7901基因组DNA扩增Reg Ⅰ基因启动子1414bp片段,将该片段插入pMD19-T载体,序列分析鉴定.应用随机引物法以地高辛分别标记1414bp及其HindⅢ酶切800bp和614bp片段,经灵敏度检测后,作为探针.应用Genomatix MatInspector在线分析软件分析Reg Ⅰ基因启动子1414bp片段的转录因子结合位点.分别以10-7 mol/L和10-8mol/L胃泌素G-17处理胃癌细胞SGC7901 48h,提取核蛋白.应用DNA-蛋白质印迹法(Southern blotting),分别以地高辛标记的1414bp、800bp和614bp片段为探针检测胃泌素对胃癌细胞SGC7901 Reg Ⅰ基因转录因子的效应.结果 1414bp探针可检测到20条蛋白主带.胃泌素孵育后,带型没有变化,但是一些条带的灰度值改变,带9、12、13、14、15和16的灰度值明显降低(P＜0.05);不同浓度胃泌素处理组之间上述6个条带的灰度值差异不明显(P＞0.05).614bp探针可检测到灰度值变化的6条主带中的带9、12和13,胃泌素处理后,此3条主带的灰度值明显降低(P＜0.05).800bp探针可检测到灰度值变化的6条主带中的带9、12和14,胃泌素处理后,仅带14的灰度值明显降低(P＜0.05).614bp和800bp探针均未检出带15和带16.结论 胃癌细胞SGC7901Reg Ⅰ基因表达由多个转录因子协同调控.降低几个转录因子的结合活性可能是胃泌素上调胃癌细胞SGC7901Reg Ⅰ基因表达的途径之一.     

Prevalence of urinary tract infection in acutely unwell children in general practice: a prospective study with systematic urine sampling

Background

Urinary tract infection (UTI) in children may be associated with long-term complications that could be prevented by prompt treatment.

Aim

To determine the prevalence of UTI in acutely ill children ≤ 5 years presenting in general practice and to explore patterns of presenting symptoms and urine sampling strategies.

Design and setting

Prospective observational study with systematic urine sampling, in general practices in Wales, UK.

Method

In total, 1003 children were recruited from 13 general practices between March 2008 and July 2010. The prevalence of UTI was determined and multivariable analysis performed to determine the probability of UTI.

Result

Out of 597 (60.0%) children who provided urine samples within 2 days, the prevalence of UTI was 5.9% (95% confidence interval [CI] = 4.3% to 8.0%) overall, 7.3% in those < 3 years and 3.2% in 3–5 year olds. Neither a history of fever nor the absence of an alternative source of infection was associated with UTI (P = 0.64; P = 0.69, respectively). The probability of UTI in children aged ≥3 years without increased urinary frequency or dysuria was 2%. The probability of UTI was ≥5% in all other groups. Urine sampling based purely on GP suspicion would have missed 80% of UTIs, while a sampling strategy based on current guidelines would have missed 50%.

Conclusion

Approximately 6% of acutely unwell children presenting to UK general practice met the criteria for a laboratory diagnosis of UTI. This higher than previously recognised prior probability of UTI warrants raised awareness of the condition and suggests clinicians should lower their threshold for urine sampling in young children. The absence of fever or presence of an alternative source of infection, as emphasised in current guidelines, may not rule out UTI in young children with adequate certainty.     

乙型肝炎病毒对肝内TGF-β1/Smads信号通路的作用

 目的：探讨乙型肝炎病毒（HBV）对肝内TGF-β1蛋白表达及Smads信号通路的作用,为制定慢性乙肝肝纤维化临床治疗策略提供理论依据。方法：(1)运用免疫组化PV-6000法检测对照组和慢性乙肝组肝组织中TGF-β1、HBsAg和HBcAg的表达,并采用荧光定量PCR法测定慢性乙肝患者血清HBV DNA含量。(2)应用体外细胞培养技术培养HBV刺激的人肝星状细胞系LX-2细胞,Western blotting方法测定其细胞内TGF-β1、Smad3和Smad7的蛋白表达。结果：(1)慢性乙肝组肝组织内TGF-β1的表达高于对照组（P＜0.01）;肝内TGF-β1表达水平与血清HBV DNA含量呈正相关（P＜0.01）,且HBcAg阳性肝组织水平较高（P＜0.01）。(2)体外细胞学实验中,HBV刺激组LX-2细胞内TGF-β1和Smad3蛋白含量高于对照组和HBV+抗-TGF-β1组（P＜0.01）;Smad7蛋白表达差异无统计学意义（P>0.05）。结论：(1)TGF-β1在慢性乙肝患者肝组织中的表达与血清HBV DNA含量及肝内HBcAg的表达有关。(2)在TGF-β1/Smads信号通路中,HBV致纤维化作用机制以Smad3的正性调控为主,Smad7的作用不明显。     

血清及尿液特定蛋白检测在糖尿病肾病早期诊断中的意义

目的探讨尿微量白蛋白(MA)、尿α1-微球蛋白(α1-MG)、尿β2-微球蛋白(β2-MG)及血清β2-微球蛋白(β2-MG)在糖尿病肾病早期诊断中的意义。方法收集67例2型糖尿病患者和82名正常健康人的血清及尿液,分别利用化学发光法检测血清β2-MG、放射免疫法测定尿β2-MG及散射速率比浊法测定尿MA和尿α1-MG水平。结果与正常对照组相比,糖尿病组4组特定蛋白水平明显升高,结果有显著性差异(P均<0.05);此4组蛋白在正常对照组测得的结果无一例阳性,但在糖尿病组的阳性率分别为32.8%、47.8%、35.8%、34.3%;实验还发现随着病程的延长,糖尿病组4组蛋白的阳性率也相应升高(P<0.05)。结论测定尿液中MA、α1-MG、β2-MG及血清β2-MG水平对糖尿病肾病的早期诊断具有一定意义,能够帮助患者及早发现病情,减少疾病迁延。