Molecular genetics of Brugada syndrome

Brugada syndrome (BrS) is a life-threatening cardiac rhythm disorder characterized by persistent STsegment elevation in leads V1–V3 and right bundle branch block on electrocardiograms (ECG), and by syncope and sudden death from ventricular tachycardia (VT) and ventricular fibrillation (VF). BrS is responsible for nearly 4% of sudden cardiac deaths and considered to be the most common cause of natural death in males younger than 50 years in some Asian countries. Since the first diseasecausing gene for BrS (the cardiac sodium channel gene SCN5A) was identified in 1998, extensive investigations on both clinical and basic aspects of BrS have occurred rapidly. SCN5A mutations remain the most common cause of BrS; nearly 300 SCN5A mutations have been identified and are responsible for 20%–30% of BrS cases. Commercial genetic testing is available for SCN5A. Recently, seven other disease-causing genes for BrS have been identified and include GPD1L (BrS2), CACNA1C (Cav1.2, BrS3), CACNB2 (Cavβ2, BrS4), SCN1B (Navβ1, BrS5), KCNE3 (MiRP2, BrS6), SCN3B (Navβ3, BrS7), and HCN4 (BrS8). This article will briefly review the progress made over the past decade in our understanding of the clinical, genetic and molecular aspects of BrS.     

Genomic typing of the Echinococcus granulosus isolates from the areas of Southern Urals

Nine larvocysts of Echinococcus granulosus isolated from nine patients and one cyst derived from a naturally infested cattle have been examined. Genomic typing was carried out in order to identify strains of E. granulosus. All DNA samples were shown to have the same genotype, E. granulosus G1.     

Fine mapping and candidate gene analysis of <Emphasis Type="Italic">qFL-chr1</Emphasis>, a fiber length QTL in cotton

Key message

A fiber length QTL, qFL-chr1, was fine mapped to a 0.9 cM interval of cotton chromosome 1. Two positional candidate genes showed positive correlation between gene expression level and fiber length.

Abstract

Prior analysis of a backcross-self mapping population derived from a cross between Gossypium hirsutum L. and G. barbadense L. revealed a QTL on chromosome 1 associated with increased fiber length (qFL-chr1), which was confirmed in three independent populations of near-isogenic introgression lines (NIILs). Here, a single NIIL, R01-40-08, was used to develop a large population segregating for the target region. Twenty-two PCR-based polymorphic markers used to genotype 1672 BC₄F₂ plants identified 432 recombinants containing breakpoints in the target region. Substitution mapping using 141 informative recombinants narrowed the position of qFL-chr1 to a 1.0-cM interval between SSR markers MUSS084 and CIR018. To exclude possible effects of non-target introgressions on fiber length, different heterozygous BC₄F₃ plants introgressed between SSR markers NAU3384 and CGR5144 were selected to develop sub-NILs. The qFL-chr1 was further mapped at 0.9-cM interval between MUSS422 and CIR018 by comparisons of sub-NIL phenotype, and increased fiber length by ~1 mm. The 2.38-Mb region between MUSS422 and CIR018 in G. barbadense contained 19 annotated genes. Expression levels of two of these genes, GOBAR07705 (encoding 1-aminocyclopropane-1-carboxylate synthase) and GOBAR25992 (encoding amino acid permease), were positively correlated with fiber length in a small F₂ population, supporting these genes as candidates for qFL-chr1.

     

Morphology and Phylogenetic Placement of Three New Zoothamnium species (Ciliophora: Peritrichia) from Coastal Waters of Southern China

The morphology, infraciliature, and silverline system of three peritrichous ciliates, Zoothamnium bucciniiformum sp. n., Zoothamnium florens sp. n., and Zoothamnium zhanjiangense sp. n., were investigated based on both living and silver‐stained specimens. Zoothamnium bucciniiformum sp. n., collected from coastal waters (salinity 30‰) off Zhanjiang, southern China, can be distinguished by the following characters: dichotomously branched stalk, peristomial lip with medial circumferential infolding, contractile vacuole apically positioned, 32–49 silverlines between the anterior end and the aboral trochal band, 15–26 between the aboral trochal band and the scopula; two kineties in peniculus 3, not parallel to each other. Zoothamnium florens sp. n., collected from a mangrove wetland (salinity 13‰) off Zhanjiang, is characterized by its large conical zooid, tuberculate peristomial lip, asymmetrical dichotomously branched colony, 59–81 silverlines between the anterior end and the aboral trochal band and 29–36 between the aboral trochal band and the scopula. Zoothamnium zhanjiangense, collected from a mangrove wetland (salinity about 9.5‰) off Zhanjiang, differs from its congeners by the alternately branched stalk, peristomial lip with medial circumferential infolding, 40–63 silverlines from the peristomial area to the aboral trochal band and 13–24 from the aboral trochal band to the scopula. The comparison and analysis of SSU rDNA sequences also support present identifications.     

Ubiquitin-fusion degradation pathway: a new strategy for inducing CD8 cells specific for mycobacterial HSP65

The ubiquitin-proteasome system (UPS) plays an indispensable role in inducing MHC class I-restricted CD8⁺ T cells. In this study, we exploited UPS to induce CD8⁺ T cells specific for mycobacterial HSP65 (mHSP65), one of the leading vaccine candidates against infection with Mycobacterium tuberculosis. A chimeric DNA termed pU-HSP65 encoding a fusion protein between murine ubiquitin and mHSP65 was constructed, and C57BL/6 (B6) mice were immunized with the DNA using gene gun bombardment. Mice immunized with the chimeric DNA acquired potent resistance against challenge with the syngeneic B16F1 melanoma cells transfected with the mHSP65 gene (HSP65/B16F1), compared with those immunized with DNA encoding only mHSP65. Splenocytes from the former group of mice showed a higher grade of cytotoxic activity against HSP65/B16F1 cells and contained a larger number of granzyme B- or IFN-γ-producing CD8⁺ T cells compared with those from the latter group of mice.     

I-STOD: a new standardization method for analysing indirect-ELISA results of a schistosomiasis field study

Variability among samples analysed using the same ELISA protocol generates ambiguity in deciding which assay best quantifies the protein concentration. In this study, we propose a standardization method, called I-STOD (Improved STandardization method for Optical Density), for the transformation of OD values on different plates into relative concentrations of the antibody levels being assessed. We derived an equation relating OD values of different test samples to antibody levels according to the multi-stage reaction dynamics of the indirect-ELISA. Using serum samples from a Schistosomiasis japonica endemic area, we evaluated the fitness of the I-STOD model to experimental data of a standard reference serum in comparison with 5 other models. Calibration curves fitted by the I-STOD method judged to be superior, based on adjusted R2 (adjusted R2>0.99 on 22 out of 26 plates) values. The CV (coefficient of variation) value of the results between multi-well plates and the number of plates with OD values beyond the control range in Shewhart charts also demonstrate that the I-STOD method is a powerful tool which can greatly improve the comparability of results on different multi-well ELISA plates. We conclude that a standardization method is certainly necessary for antibody levels detected in order to properly illustrate clinical differences.     

The PathoChip,a functional gene array for assessing pathogenic properties of diverse microbial communities

Pathogens present in the environment pose a serious threat to human, plant and animal health as evidenced by recent outbreaks. As many pathogens can survive and proliferate in the environment, it is important to understand their population dynamics and pathogenic potential in the environment. To assess pathogenic potential in diverse habitats, we developed a functional gene array, the PathoChip, constructed with key virulence genes related to major virulence factors, such as adherence, colonization, motility, invasion, toxin, immune evasion and iron uptake. A total of 3715 best probes were selected from 13 virulence factors, covering 7417 coding sequences from 1397 microbial species (2336 strains). The specificity of the PathoChip was computationally verified, and approximately 98% of the probes provided specificity at or below the species level, proving its excellent capability for the detection of target sequences with high discrimination power. We applied this array to community samples from soil, seawater and human saliva to assess the occurrence of virulence genes in natural environments. Both the abundance and diversity of virulence genes increased in stressed conditions compared with their corresponding controls, indicating a possible increase in abundance of pathogenic bacteria under environmental perturbations such as warming or oil spills. Statistical analyses showed that microbial communities harboring virulence genes were responsive to environmental perturbations, which drove changes in abundance and distribution of virulence genes. The PathoChip provides a useful tool to identify virulence genes in microbial populations, examine the dynamics of virulence genes in response to environmental perturbations and determine the pathogenic potential of microbial communities.     

The relation of oxidative stress and apoptosis to histopathologic alterations in the lungs as a result of global cerebral ischemia

ABSTRACT

Heart attack and oxygen deficiency may cause necrosis in the brain and other tissues. We investigated the histopathological effects of nitric oxide (NO) on ischemia/reperfusion in lung and hippocampus using a rat brain bilateral occlusion ischemia model. Male rats were assigned to sham (SH), ischemic preconditioning (PC), global ischemia (GI) and ischemic reperfusion (IR) groups. Before ischemia was induced, blood was drawn to induce hypovolemic hypotension and for blood gas testing. After sacrifice, samples of hippocampus were harvested. Sections were examined using hematoxylin and eosin (H & E) staining and immunostaining using primary antibodies for GFAP, S100β, iNOS, eNOS and the TUNEL method. Following ischemia, we found evidence of gliosis induced oxidative stress and apoptosis in the hippocampus. No significant differences were detected between the SH and PC groups. In the GI and IR groups, apoptosis and necrosis were observed in the hippocampus. Lung sections were stained with H & E and Masson’s trichrome (MT) and immunostained for iNOS and eNOS. The TUNEL method was used to detect apoptosis. Interstitial edema, vascular congestion, intra-alveolar hemorrhage, perivascular edema, neutrophil infiltration and disruption of alveoli were observed after global ischemia and ischemic reperfusion. Inflammatory cells were detected in the connective tissue. The IR and GI groups exhibited significantly more apoptotic cells than the SH or PC groups. Free radicals, such as nitric oxide (NO), that appear following ischemia and reperfusion in the brain may also injure the lungs. Increased NO in both lung and brain tissue suggests that apoptosis in these organs can be induced by reactive nitrogen species.     

藏药毛蕊杜鹃挥发油化学成分的GC-MS分析

目的：通过研究毛蕊杜鹃挥发油的化学成分,为毛蕊杜鹃的药用及开发利用提供依据.方法：采用水蒸气蒸馏法提取毛蕊杜鹃挥发油,用GC毛细管柱进行分离,归一化法测其相对含量,并用气相色谱-质谱法对化学成分进行鉴定.结果：共鉴定出38个化合物,鉴定出的化合物含量占总挥发油的92.96％.结论：毛蕊杜鹃挥发油主要成分为δ-杜松烯（相对含量为15.90％）;胡萝卜醇（15.09％）;α-杜松醇（15.02％）;τ-杜松醇（9.66％）;α-衣兰油烯（4.25％）;1,2,3,4,4a,5,6,8a-八氢-7-甲基-4-亚甲基-1-[1-甲基乙基]-萘（4.14％）;1,7-二甲基-4-异丙基-2,7-环癸二烯-1-羟基（3.27％）;石竹烯（2.86％）;5-甲基-9-亚甲基-2-异丙基-二环[4.4.0]癸-1-烯（2.62％）;1,4-二甲基-3-[2-甲基-1-丙烯-1-基]-4-乙烯基-1-环庚烯（2.42％）;γ-衣兰油烯（2.21％）;愈创醇（1.50％）;β-古芸烯（1.34％）.