RyR2 Modulates a Ca2+-Activated K+ Current in Mouse Cardiac Myocytes

In cardiomyocytes, Ca²⁺ entry through voltage-dependent Ca²⁺ channels (VDCCs) binds to and activates RyR2 channels, resulting in subsequent Ca²⁺ release from the sarcoplasmic reticulum (SR) and cardiac contraction. Previous research has documented the molecular coupling of small-conductance Ca²⁺-activated K⁺ channels (SK channels) to VDCCs in mouse cardiac muscle. Little is known regarding the role of RyRs-sensitive Ca²⁺ release in the SK channels in cardiac muscle. In this study, using whole-cell patch clamp techniques, we observed that a Ca²⁺-activated K+ current (I_K,Ca) recorded from isolated adult C57B/L mouse atrial myocytes was significantly decreased by ryanodine, an inhibitor of ryanodine receptor type 2 (RyR2), or by the co-application of ryanodine and thapsigargin, an inhibitor of the sarcoplasmic reticulum calcium ATPase (SERCA) (p<0.05, p<0.01, respectively). The activation of RyR2 by caffeine increased the I_K,Ca in the cardiac cells (p<0.05, p<0.01, respectively). We further analyzed the effect of RyR2 knockdown on I_K,Ca and Ca²⁺ in isolated adult mouse cardiomyocytes using a whole-cell patch clamp technique and confocal imaging. RyR2 knockdown in mouse atrial cells transduced with lentivirus-mediated small hairpin interference RNA (shRNA) exhibited a significant decrease in I_K,Ca (p<0.05) and [Ca²⁺]i fluorescence intensity (p<0.01). An immunoprecipitated complex of SK2 and RyR2 was identified in native cardiac tissue by co-immunoprecipitation assays. Our findings indicate that RyR2-mediated Ca²⁺ release is responsible for the activation and modulation of SK channels in cardiac myocytes.     

白念珠菌SSK1突变株对氟康唑敏感性的初步研究

目的探讨氟康唑作用于白念珠菌双组分信号传导途径SSK1突变株SSK21后药物敏感性的变化。方法采用微量液体稀释法和固醇测定法测定野生株(CAF2-1)和突变株(SSK21)的最小抑菌浓度(MIC);并应用RT-PCR观察氟康唑作用前后,SSK1的表达变化。结果氟康唑对CAF2-1的MIC为16μg/mL,对SSK21为0.032μg/mL。加入氟康唑后,CAF2-1的SSK1表达明显增加,60min时达到最多。结论 SSK21对氟康唑高度敏感,SSK1基因及其相关的重要基因与药物敏感性的关系值得进一步研究,从而为新的抗真菌药物和治疗途径的研发提供参考。     

pH及氧气对白念珠菌菌丝形成的影响

目的探讨pH值和氧气对白念珠菌菌丝形成的影响。方法通过调节Muller—Hinton液体培养基的pH值和去除培养基中的氧气来观察白念珠菌的生长曲线、倍增时间和菌丝形成率的变化。结果在无氧气的液体培养基中,白念珠菌生长缓慢,不能产生菌丝结构,只有酵母细胞形成。生长曲线的延缓期内各组没有明显差异,而在生长的对数期pH3和pH4的条件下念珠菌生长速度明显慢于pH5、pH6、pH7、pH8和pH9。菌丝形成率在pH3、pH4和pH5条件下〈20％,而在pH6、pH7、pH8和pH9条件下可高达70％。结论厌氧条件抑制白念珠菌的菌丝形成,只形成酵母细胞。白念珠菌在pH3—9的范围内均能生长,偏酸性环境有利于白念珠菌酵母形成,偏碱性的环境有助于菌丝的形成。     

医学真菌基因组研究进展（下）

近年来,一系列重要医学致病真菌全基因组数据陆续被公布,使人类对这些致病菌的认识提高到全新水平。本文在回溯医学真菌基因组学和基因组测序技术发展历程、综述其发展现状及应用的基础上,再分别介绍重要医学真菌全基因组测序的进展。     

血红蛋白200g/L以上紫绀型先天性心脏病患者手术效果分析

目的:明确血红蛋白200 g/L以上紫绀型先天性心脏病患者的手术效果。方法:选取2009年3月至2012年3月于我中心就诊手术治疗的紫绀型先天性心脏病患者,按血红蛋白计数≥200 g/L和200 g/L分为A组和B组,完善术前检查后进行手术治疗。记录患者手术效果和随访情况;观察比较两组患者手术中情况包括:手术方式、手术时间、体外循环时间、心脏停搏时间、心脏自动复跳情况;记录并比较两组患者手术后恢复情况,包括机械通气时间、监护室滞留时间、手术后24小时内出血量、二次开胸止血例数和血管活性药物评分,以及监护室内肝肾功能异常和肺部并发症发生例数。结果:A组死亡3例(5.2%),23例术后3个月随访效果良好;B组死亡2例(5.8%),12例术后3个月随访效果良好。两组患者手术方式、手术时间、体外循环时间和心脏停搏时间、自动复跳例数均无明显差异(P0.05)。与B组比较,A组患者术后机械通气和监护室滞留时间长,术后24小时出血量多,血管活性药物使用评分高,肝肾功能异常例数和肺部并发症发生例数较多有统计学意义(P0.05),两组间二次开胸止血例数无统计学差异(P0.05)。结论:血红蛋白200 g/L以上紫绀型先天性心脏病患者与其他紫绀型先天性心脏病患者手术效果相似,但手术后恢复慢,并发症较多。     

南海北部近海头足类优势种及其生态位特征

为了解南海北部近海头足类优势种的种间关系,根据2014—2015年该海域4个季节底拖网渔业资源调查,应用相对重要性指数、生态位宽度和重叠指数从时空维度分析头足类优势种的生态位特征。结果表明: 该海域4个季节的头足类优势种共5种,分别为剑尖枪乌贼、中国枪乌贼、火枪乌贼、金乌贼和杜氏枪乌贼,前两种是4个季节的共同优势种。与历史数据相比,头足类优势种的种类组成已发生改变。头足类资源时空分布格局明显,海南岛南部至粤东海域资源密度高于北部湾,季节变化呈夏季高而冬季低特征。时空生态位分析表明,优势种的时间和空间生态位宽度没有一致位序,剑尖枪乌贼和中国枪乌贼分别占据最大的时间(1.32)和空间生态位宽度(3.90),而时间和空间生态位宽度最小的物种分别是金乌贼(0.98)和杜氏枪乌贼(2.04)。虽然时间生态位重叠在数值上显著高于空间生态位重叠,但二者均是在中国枪乌贼、剑尖枪乌贼、火枪乌贼等种对间有较高重叠,而杜氏枪乌贼与其余4个优势种的重叠较低。相关分析表明,在时空尺度上生态位宽度与丰度的变化均呈极显著负相关。生态位可反映物种资源量时空变化信息,丰富了传统渔业群落研究方法。     

嗜盐古生菌AJ4中BR蛋白基因部分片段和16S rRNA基因序列研究

为了研究分析新疆阿尔金山国家自然保护区阿牙克库木湖嗜盐古生菌物种与细菌视紫红质(bacteriorhodopsin ,BR)蛋白资源 ,对分离纯化到的极端嗜盐古生菌AJ4 ,采用PCR方法扩增出其 16SrRNA基因 (16SrDNA)和编码螺旋C至螺旋G的BR蛋白基因片断 ,并测定了基因的核苷酸序列 .通过BR蛋白部分片段序列分析表明 ,BR蛋白中对于完成质子泵功能以及与视黄醛结合的关键性氨基酸残基均为保守序列 ,位于膜内侧的序列比位于膜外侧的序列更保守 ;基于BR蛋白基因和16SrDNA序列的同源性比较以及 16SrDNA序列的系统发育学研究表明 ,AJ4是Haloarcula属中新成员 .由此建立了一种快速筛选具有新BR蛋白的新嗜盐古生菌的方法 .     

Serum Levels of Interleukin-9 Correlate with Negative Prognostic Factors in Extranodal NK/T-Cell Lymphoma

Interleukin-9 (IL-9) is more functionally diverse than previously expected, especially with regards to lymphomagenesis. However, the relationship between IL-9 and the clinicopathological features of extranodal NK/T-cell lymphoma is less well established. Patients with this lymphoma in Sun Yat-Sen University Cancer Center between January 2003 and March 2013 were systematically reviewed in an intention-to-treat analysis. Baseline serum IL-9 levels were determined using sandwich enzyme-linked immunosorbent assays. A total of seventy-four patients were enrolled in this study. The mean concentration of serum IL-9 for all patients was 6.48 pg/mL (range: 1.38–51.87 pg/mL). Age, B symptoms and local lymph node involvement were found to be related to high serum IL-9 levels. Patients with low IL-9 levels tended to have higher rates of complete remission. Notably, the median progression-free survival (PFS) and overall survival (OS) were longer in the low IL-9 level group than in the high IL-9 level group (PFS: 68.7 months vs. 28.3 months, P<0.001; OS: 86 months vs. 42.8 months, P = 0.001). Multivariate analysis revealed independent prognostic factors for PFS. Similarly, high IL-9 levels (P = 0.003) and old age (P = 0.007) were independently predictive of shorter OS. Serum IL-9 is closely related to several clinical features, such as age, B symptoms and local lymph node involvement. It can also be a significant independent prognostic factor for extranodal NK/T-cell lymphoma, which suggests a role for IL-9 in the pathogenesis of this disease and offers new insight into potential therapeutic strategies.     

申克孢子丝菌菌丝相至酵母相转化的实验研究

目的观察申克孢子丝菌菌丝相向酵母相转化的形态学变化并初步研究连续传代后菌株转化为酵母相的百分率。方法将95株申克孢子丝菌临床株于脑心浸液琼脂培养基上连续传代至酵母相,利用显微镜及血细胞计数板计数菌丝和孢子比例并记录显微镜下形态。结果 95株申克孢子丝菌中,经1次传代即成功转化有23株,经2次传代有14株,经3次传代有10株,经4次传代有6株,4次传代后总计55.8%实验菌株转化为酵母相。结论部分申克孢子丝菌由菌丝相向酵母相转化需经过连续多次传代,连续传代增加了菌丝相至酵母相的转化率。     

Nucleotide Sequence of A High-Molecular-Weight Glutenin Gene in Wheat

Subclones of a wheat (Triticum aestivum L. cv. asarce) genomic recombinant containing high-molecular-weight (HMW) glutenin gene were constructed by using pUCll8/pUCll9 vectors, their successive shorter deletions were also prepared: The nucleotide sequence of about 560 bp upstream of initiation codon and total coding region was analysed by Sanger's dideoxynucleotide chain termination method. It has 3067 bp which includes 830 codons and reveals high homology with a previously reported HMW glutenin gene. This gene contains no intron but a TAA termination codon within the coding region. Whether this is a silent gene or not merits further investigation.