Sphaerospora renicola n.sp., a myxosporean from carp kidney,and its pathogenicity

Sphaerospora renicola n.sp. is a common parasite of carp in Czechoslovakia. Its life cycle involves intracellular stages in the epithelial cells of renal tubuli and trophozoite stages proliferating in the tubular lumen, transforming ultimately into pansporoblasts, each having one pansporoblast nucleus and producing two spores. The spores are almost globular with an average size of 7.3×7.2 , with polar capsules of equal size, and may have two slightly protruding tubercles on their shell valves. Differential diagnosis from otherSphaerospora species infecting carp, as well as fromMitraspora cyprini Fujita, is made. Intracellular stages ofS. renicola cause swelling and hyperplasia of the epithelium in renal tubuli followed by dystrophic changes. Accumulation of developmental stages in the tubular lumen provokes pronounced regressive changes of the epithelium, which may be followed by necrosis.     

Establishment of ionic channels and signalling cascades in the embryonic stem cell-derived primitive endoderm and cardiovascular system

The first organ system to be established in early embryogenesis is the cardiovascular system which develops upon interaction with hypoblastic cells of the primitive endoderm. Here we focus on recent work on embryoid bodies derived from pluripotent embryonic stem (ES) cells. Ca(2+) oscillations and Ca(2+) signalling pathways during the differentiation of primitive endodermal cell layers are reported. Furthermore, the development-dependent expression of ion channels and the buildup of signalling cascades involved in the modulation of voltage-dependent L-type Ca(2+) channels during early cardiomyogenesis and the formation of functional vascular structures in the process of vasculogenesis and angiogenesis are reviewed. We also report on the use of green fluorescent protein reporter gene expression under the control of cardiac-specific promoters, e.g. the human cardiac alpha-actin promoter, which enables the identification and in vivo characterization of cardiomyocytes at very early stages of cardiomyogenesis.     

Monocyte chemotactic protein-3 (MCP3) interacts with multiple leukocyte receptors: binding and signaling of MCP3 through shared as well as unique receptors on monocytes and neutrophils

The diversity of monocyte chemotactic protein (MCP)3 target cell types, as well as the capacity of MCP3 to desensitize leukocyte responses to other CC chemokines, suggested that MCP3 may interact with multiple CC chemokine receptors. The purpose of this study is to establish how MCP3 binds and activates monocytes and neutrophils. We show that human monocytes exhibit high-affinity binding for ¹²⁵I-MCP3 with an estimated Kd of 1–3 nM and about 10000 binding sites/cell. The binding of ¹²⁵I-MCP3 to monocytes was progressively less well competed by CC chemokines macrophage inflammatory protein (MIP)lα (Kd = 5–10 nM), RANTES (Kd = 5–10 nM), MCP1 (monocyte chemoattractant and activating factor, or MCAF) (Kd = 60 nM) and MIP1β (Kd > 100 nM). On the other hand, unlabeled MCP3 displaced the binding of radiolabeled MIP1α, RANTES, MCP1 and MIP1β as effectively as the isologous CC chemokines. In agreement with the binding data, pretreatment of monocytes with MCP3 completely desensitized the calcium flux in response to MIP1α and RANTES. However, MIP1α and RANTES failed to desensitize the response of monocytes to MCP3. MCP3 and MCP1 partially desensitized each other's effects on monocytes. These binding and cross-desensitization results suggest that MCP3 binds and signals through other binding sites in addition to those shared with MIP1α, RANTES and MCP1. The unidirectional competition for MIP1β binding and signaling by MCP3 suggests the existence of an as-yet unidentified site for MCP3 shared with MIP1β. The existence of another unique binding site(s) for MCP3 was further shown by the failure of any of the other CC chemokines to compete effectively for MCP3 binding on neutrophils. MCP3 in our study was also the only human CC chemokine that consistently chemoattracted neutrophils. These results suggest that MCP3 is a ligand that can bind and activate a broad range of target cells through receptors shared by other CC chemokines as well as its own receptor.     

间位结肠综合征的超声诊断及临床意义

目的 探讨间位结肠综合征的超声图像特征及诊断价值；方法 对1万余例需作上腹部检查的患常规进行肝与横膈间结构层次的超声波探测，并对其中21例在肝-横膈间发现有嵌顿结构图像的患进行X线腹部平片或CT检查；结果 21例患均于肝与横膈间测及片状等回声区或增强回声区，主要位于肝左内叶至右前叶前上方，并对肝表面产生弧形压迹，其中15例能清晰显示肠管结构及气体回声，经X线腹部平片或CT检查确诊；另6例显示均匀的等回声区，经大量饮水（600-800ml)后1-1.5h复查或隔日复查，腹部平片检查确诊；结论 间位结肠综合征具有典型的超声波声像图特征，超声检查能准确地作出诊断及鉴别诊断。     

自血光量子疗法治疗病毒性肝炎72例疗效观察

1993年9月以来,用自血光量子治疗各型病毒性肝炎72例,结果所有患者症状均明显好转或消失,SB异常者恢复正常和有效分别占66.7％和90.2％,ALT异常者恢复正常和有效分别为77.4％和100％,血清白蛋白平均上升4.2g/L,球蛋白下降4.6g/L,三项凝血功能(PT、HPT、KPTT)测定结果表明量子血疗不会引起或加重肝炎患者的凝血障碍。61例乙型肝炎患者HBeAg和HBsAg的阴转率分别达59.3％和15％。     

Transition between two forms of heterochromatin at plant subtelomeres

The manner of packing of the terminal DNA loci into nucleosomes and higher order structures may strongly influence their functional interactions. Besides the structural flexibility of telomeric DNA sequences, conserved features of their chromatin including short nucleosome phasing (157 bp) and nucleosome sliding have been described previously. To gain a complementary knowledge of subtelomeres, we have analysed the chromatin structure of two subtelomeric tandem repeats from the plant Silene latifolia: X43.1 and 15Ssp. X43.1 shows two distinct nucleosome periodicities – 157 and 188 bp. Preferred positions of its two nucleosomes have been mapped at both low and high resolution and the experimental results correspond to computer-predicted positions. 15Ssp is a newly-discovered sequence showing a telomere-associated position by PCR and a subtelomeric location by pulsed-field gel electrophoresis and fluorescence in situ hybridisation. Its 159 bp sequence unit shows a tandem arrangement and the presence of micrococcal nuclease-hypersensitive sites when either naked DNA or chromatin is digested. Use of a chemical nuclease results in a regular nucleosome ladder of 157 bp periodicity. Moreover, 15Ssp mononucleosomes show instability and absence of specific positioning, features typical for telomeric chromatin. This revised version was published online in July 2006 with corrections to the Cover Date.     

多发性骨髓瘤患者血清IL-6活性与急性相蛋白浓度的相关性研究

运用敏感的B_9细胞增殖试验检测了81例多发性骨髓瘤(MM)患者血清IL-6活性,同时分析了标本的几种急性相蛋白含量,结果表明,68％MM患者血清中IL-6活性大于5μ/ml(正常对照为5μ/ml以下),几种急性相蛋白中C-反应性蛋白(CRP)在MM时升高(P<0.01),平均达正常对照组的17倍以上,MM患者补体C_4与正常对照组无差异(p>0.05),C_3、白蛋白及转铁蛋白在MM时分别比正常下降24.42％、38.83％和32.80％,且与疾病分期有关,在血清IL-6大于5μ/ml的55例中,IL-6活性与CRP、C_3、白蛋白的相关系数分别为0.46,-0.34和-0.29,IL-6与转铁蛋白浓度相关不明显。本文结果提示:CRP、C_3及白蛋白等含量的变化可作为反映MM病情的简易而敏感的指标。     

镁对在体兔缺血—再灌心脏的电生理效应

本实验通过结扎兔冠状动脉左室支复制动脉缺血－再灌注模型，应用心外膜接触电极记录单相动作电位，观察后除极电位在再灌注性心律失常中及镁离子的拮抗作用。结果表明，再灌性心律失常的５２．６％与早期后去极化有关。硫酸镁可终止及预防ＲＡ，对再灌中出现触发活动有抑制作用。     

HIV－1Protease在大肠杆菌中的高表达

艾滋病的致病因子为人免疫缺陷病毒。该病毒的蛋白酶在病毒复制和成熟中具有决定性的意义。由于目前国内外尚未获得艾滋病病毒蛋白酶高效表达的重组子及简便的活性检测系统，限制了它的研究与应用。本文将用ＰＣＲ技术修饰的ＨＩＶＰｒ基因克隆入原核高效表达载体ｐＴＴＱ１８的ＥｃｏＲⅠ和ＨｉｎｄⅢ酶切位点之间，并用豆芽核酸酶将ＥｃｏＲⅠ的粘端削平，构建了读框正确的表达载体，ＩＰＴＧ诱导表明，该重组子在大肠杆菌中获得了高表达，激光扫描结果表明：重组的ＨＩＶＰｒ占细菌总蛋白８．９％以上。