口腔常见细菌集聚作用对表面疏水性的影响

目的研究口腔常见细菌集聚作用对细菌表面疏水性的影响,从而进一步探讨细菌表面疏水性与细菌间集聚的关系.方法采用微生物粘着碳氢化合物法,测定5种口腔常细菌相互集聚后的细胞表面疏水率,并与该5种细菌的细胞表面疏水率进行比较.结果将两种细菌混合后,细菌表面疏水率出现四种变化：（1）与混合前两种细菌的细胞表面疏水率无明显差别;（2）介于混合前两种细菌细胞表面疏水率之间;（3）高于混合前两种细菌细胞表面疏水率;（4）低于混合前两种细菌细胞表面疏水率.结论细菌间的相互集聚作用对细胞表面疏水性有影响.     

CAG repeat lengths ≥ 335 attenuate the phenotype in the R6/2 Huntington's disease transgenic mouse

With spontaneous elongation of the CAG repeat in the R6/2 transgene to ≥ 335, resulting in a transgene protein too large for passive entry into nuclei via the nuclear pore, we observed an abrupt increase in lifespan to > 20 weeks, compared to the 12 weeks common in R6/2 mice with 150 repeats. In the ≥ 335 CAG mice, large ubiquitinated aggregates of mutant protein were common in neuronal dendrites and perikaryal cytoplasm, but intranuclear aggregates were small and infrequent. Message and protein for the ≥ 335 CAG transgene were reduced to one-third that in 150 CAG R6/2 mice. Neurological and neurochemical abnormalities were delayed in onset and less severe than in 150 CAG R6/2 mice. These findings suggest that polyQ length and pathogenicity in Huntington's disease may not be linearly related, and pathogenicity may be less severe with extreme repeats. Both diminished mutant protein and reduced nuclear entry may contribute to phenotype attenuation.     

Antiaggregant effects of Arbutus unedo extracts in human platelets

Platelet hyperaggregability plays a pivotal role in the pathogenesis of cardiovascular diseases. Thrombin evokes aggregation through Ca(2+) mobilization, tyrosine phosphorylation and generation of reactive oxygen species (ROS). We have investigated the antiaggregant properties of Arbutus unedo extracts in human platelets. Changes in cytosolic Ca(2+) concentration and intracellular oxidants production were registered by espectrofluorimetry using fura-2 and dichlorodihydrofluorescein, respectively, platelet aggregation was assessed by aggregometry and protein tyrosine phosphorylation was detected by Western blotting. Platelet treatment with increasing concentrations (0.015-1.5mg/mL) of crude aqueous, ethyl acetate or diethyl ether extracts reduced platelet aggregation evoked by thrombin (0.5 U/mL) and show a potent ROS scavenger activity, preventing thrombin-evoked endogenous generation of ROS. Treatment with Arbutus unedo extracts did not alter thrombin-evoked Ca(2+) release from the intracellular stores but reduced store-operated Ca(2+) entry induced by thrombin or by selective depletion of the two Ca(2+) stores in platelets, the dense tubular system and the acidic stores. In addition, platelet treatment with extracts reduced both basal and thrombin-stimulated protein tyrosine phosphorylation. We conclude that Arbutus unedo extracts show antiaggregant actions due to attenuation of Ca(2+) mobilization, ROS production and protein tyrosine phosphorylation and might be used for the treatment and/or prevention of cardiovascular diseases.     

电场对红细胞沉降率的影响Ⅵ——电场方式依赖性

利用自行研制的红细胞流变参数自动测试分析仪及显微形态观测法，研究了三种电场方式对红细胞在生理盐水溶液中及在自体血浆中沉降及聚集特性的影响。结果表明，交流电场能使悬浮于生理盐水溶液中的红细胞产生轻度聚集，沉降过程加快。直流恒流电场不能 于一时卤水中的红细胞发生聚集，其沉降过程加快仅电场力作用所致。直流恒压电场 下红细胞在生理直 的沉降曲线为指数形，但这种指数形曲线与红细胞聚集无在，而是回路中电流随时     

Pathogenic ASXL1 somatic variants in reference databases complicate germline variant interpretation for Bohring–Opitz Syndrome

The clinical interpretation of genetic variants has come to rely heavily on reference population databases such as the Exome Aggregation Consortium (ExAC) database. Pathogenic variants in genes associated with severe, pediatric‐onset, highly penetrant, autosomal dominant conditions are assumed to be absent or rare in these databases. Exome sequencing of a 6‐year‐old female patient with seizures, developmental delay, dysmorphic features, and failure to thrive identified an ASXL1 variant previously reported as causative of Bohring–Opitz syndrome (BOS). Surprisingly, the variant was observed seven times in the ExAC database, presumably in individuals without BOS. Although the BOS phenotype fit, the presence of the variant in reference population databases introduced ambiguity in result interpretation. Review of the literature revealed that acquired somatic mosaicism of ASXL1 variants (including pathogenic variants) during hematopoietic clonal expansion can occur with aging in healthy individuals. We examined all ASXL1 truncating variants in the ExAC database and determined most are likely somatic. Failure to consider somatic mosaicism may lead to the inaccurate assumption that conditions like BOS have reduced penetrance, or the misclassification of potentially pathogenic variants.     

Identification of a novel BICRA variant leading to the newly described Coffin–Siris syndrome 12

BackgroundPathogenic heterozygous variants in BICRA have recently been identified in patients with SWI/SNF-related intellectual disability (SSRIDD) – Coffin-Siris syndrome 12. So far, only one article reported SSRIDD associated with pathogenic variants in BICRA.Case presentationThe patient’s phenotype include low birth weight, microcephaly, neurodevelopment delay, visual, gastrointestinal, urinary tract impairment, and craniofacial dysmorphism. Whole exome sequencing revealed a novel pathogenic heterozygous variant in exon 6 of BICRA gene c.535C > T (p.(Gln179*)). Sanger sequencing confirmed de novo origin.ConclusionThe clinical findings confirm and supplement the previous study which showed that pathogenic variant in BICRA is commonly characterized by neurodevelopmental, gastrointestinal, and ophthalmologic symptoms, growth retardation, as well as craniofacial dysmorphism.