Accentuated antagonism by angiotensin II on guinea-pig cardiac L-type Ca-currents enhanced by β-adrenergic stimulation

 To examine mechanism(s) underlying the accentuated antagonism by angiotensin II (A-II) on twitch tension, we recorded L-type Ca²⁺ currents (I _Ca,L) using conventional patch-clamp techniques in single, guinea-pig, ventricular myocytes. I _Ca,L was recorded by a step-pulse protocol after eliminating K⁺ conductances (internal Cs⁺ plus tetraethylammonium chloride and K⁺-free extracellular solution). A-II (100 nM) did not affect basal I _Ca,L, but inhibited I _Ca,L that had been enhanced (approximately 200% of control) by (ISO, isoproterenol 100 nM). The inhibitory action of A-II was concentration dependent (concentration eliciting 50% inhibition 88±9 pM, n=41) and the ISO-enhanced component of I _Ca,L was completely blocked by A-II at concentrations above 10 nM. CV-11974 (500 nM), an A-II type-1 receptor (AT₁) antagonist, prevented the inhibitory action of A-II. Pre-incubation with pertussis toxin (PTX) abolished the inhibitory effect of A-II. A-II also inhibited the I _Ca,L enhanced by histamine (500 nM) and forskolin (1 μM), but failed to affect I _Ca,L enhanced by intracellular cyclic adenosine monophosphate (1 mM). The inhibitory action of A-II may therefore involve AT₁ receptors/PTX-sensitive, guanine nucleotide-binding (G) proteins (Gi)/adenylate cyclase and partially explains the A-II-dependent accentuated antagonism of inotropy.     

特殊型前列腺增生症的诊治

收治特殊型前列腺增生症１１０例，分别伴有逼尿肌无力、不稳定性膀胱、前列腺结石、膀胱结石、前列腺炎或糖尿病。认为：治疗前认真检查发现特殊前列腺增生症，是提高治愈率、减少并发症的关键步骤之一。     

bcl-2反义寡核苷酸对膀胱癌BIU87细胞株的影响

目的:探讨bcl-2反义寡核苷酸对培养的膀胱癌BIU87细胞株的影响.方法:采用bcl-2基因第1外显子的反义寡核苷酸,以硫代磷酸修饰(PS-ASON),序列为5′-TCTCCCAGCGTGCGCCAT-3′,与膀胱癌细胞株BIU87共同孵育作为实验组.加入正义的bcl-2寡核苷酸,序列为5′-TACCGCGTGCGACCCTCT-3′(PS-SON)作为对照组,用流式细胞仪检测细胞凋亡和坏死率,电镜观察细胞形态变化.结果:与对照组相比,实验组的细胞坏死率明显上调,电镜下细胞形态呈坏死改变.结论:bcl-2的反义寡核苷酸引起膀胱癌细胞大量坏死,可能成为膀胱癌的治疗方法之一.     

原癌基因蛋白质C-erbB-2在乳腺良恶性病变中表达的意义

目的:检测原癌基因蛋白质C-erbB-2在乳腺良恶性病变中的表达及意义.方法:对111例乳腺良恶性病变的石蜡切片标本进行免疫组织化学染色.结果:乳腺良恶性病变中乳腺导管内乳头状瘤病的C-erbB-2阳性率为31.3%,与乳腺纤维腺病和纤维腺瘤比较差异有显著性(P<0.01),乳腺癌C-erbB-2的阳性率为74.3%,与良性病变比较差异有显著性(P<0.01);乳腺癌C-erbB-2表达与肿瘤大小和组织学分级呈正比(P<0.05),与激素受体(ER、PR)水平及5年生存期呈反比(P<0.05),与淋巴结是否转移无关.结论:C-erbB-2表达的乳腺导管内乳头状瘤病容易癌变,C-erbB-2过度表达的乳腺癌组织分化差、生存期短、预后不好.C-erbB-2 可作为判定乳腺导管内乳头状瘤病早期癌变及乳腺癌预后的有效指标.     

步行量和体成分的中日比较研究

目的 为了解中日儿童及成人的步行和体成分及其相互关系.方法 以中国上海市和日本琦玉县的小学生和成人为对象,采用西铁城 TW02-001电子式步数计测定步行量,FUTREX-5000A体成分测定仪测量体脂百分比.结果 1.中国男女小学生的平均每日步行量分别为12426步和10387步,低于日本小学生(男15 340步,女11 617步),体脂百分比中国男女生分别为21.2%和15.8%,高于日本(男18.9%,女13.1%).中国男女成人的平均每日步行量分别为9826步和8748步,高于日本成人(男:8411步,女7599步);体脂百分比分别为17.5%(男)和25.8%(女),而日本男性为19.8%,女性为26.0%.2.不同活动水平的小学生和成人,其血压和体成分均有差异,步行量高者的血压和体脂百分比都较低.本研究还计算出以肱三头肌皮脂厚度以(X)推测儿童体脂百分比(Y)的回归方程为:Y=10.6646+0.5856X.结论 作为日常生活的步行可促进肥胖发生率的降低.     

薄层扫描法测定食物中胆固醇的含量

本文探讨食物中胆固醇的薄层光密度法的测定。用硅胶Ｇ与０．３％ＣＭＣ－Ｎａ按１：２．２比例制成薄层板，石油醚－乙醚－－冰醋酸（７：３：０．１）为展开剂，５％磷钼酸乙醇溶液显色，日本岛津ＣＳ－９１０型薄层扫描仪定量扫描，测得精神异系数（ＲＤＳ％）为２．９２。稳定性变异系数（ＲＳＤ％）为２．３５，加嘏率在８７．９５－９４．２９％范围内。与气相色谱法（其回收率在９２－１０３％范围）比较，结果相接近，该法简     

腹主动脉与其主支夹角的空间定位

甲醛固定的成人尸体32具(男19,女13),造影拍片和实地解剖对照观察,测量腹主动脉主支的发出高度、起点方位、与主动脉的夹角,以及与矢状面的交角。综合以上四项指标,即能构想腹主动脉与其主支夹角的空间位置和变动范围。     

Development of a Western Blot Assay for Detection of Antibodies against Coronavirus Causing Severe Acute Respiratory Syndrome

To identify a major antigenic determinant for use in the development of a rapid serological diagnostic test for severe acute respiratory syndrome (SARS) coronavirus infection and to study the immune response during SARS coronavirus infection in humans, we cloned the full length and six truncated fragments of the nucleocapsid gene, expressed them, and purified them as glutathione S-transferase-tagged recombinant proteins. The reactivities of the recombinant proteins to a panel of antibodies containing 33 SARS coronavirus-positive sera and 66 negative sera and to antibodies against other animal coronaviruses were screened. A truncated 195-amino-acid fragment from the C terminus of the nucleocapsid protein (N195) was identified that had a strong ability to detect antibodies against SARS coronavirus. No cross-reaction was found between the N195 protein and antibodies against chicken, pig, and canine coronaviruses. The N195 protein was used to develop a Western blot assay to detect antibodies against SARS coronavirus in 274 clinically blinded samples. The specificity and sensitivity of this test were 98.3 and 90.9%, respectively. The correlation between our Western blotting assay and an immunofluorescence assay (IFA) was also analyzed. The results of our Western blot assay and IFA for the detection of SARS coronavirus-positive sera were the same. Thus, the N195 protein was identified as a suitable protein to be used as an antigen in Western blot and other possible assays for the detection of SARS coronavirus infection.     

Novel immunofluorescence assay using recombinant nucleocapsid-spike fusion protein as antigen to detect antibodies against severe acute respiratory syndrome coronavirus

Severe acute respiratory syndrome (SARS) is caused by a novel and highly infectious virus named SARS coronavirus (SARS-CoV). Among the serological tests currently available for the detection of SARS-CoV, a whole-virus-based immunofluorescence assay (IFA) was considered one of the most sensitive assays and served as a "gold standard" during the SARS epidemic in Singapore in 2003. However, the need to manipulate live SARS-CoV in the traditional IFA limits its wide application due to the requirement for a biosafety level 3 laboratory and the risk of laboratory infection. Previously, we have identified two immunodominant epitopes, named N195 and Sc, in the two major structural proteins, the N and S proteins, of SARS-CoV (Q. He, K. H. Chong, H. H. Chng, B. Leung, A. E. Ling, T. Wei, S. W. Chan, E. E. Ooi, and J. Kwang, Clin. Diagn. Lab. Immunol., 11:417-422, 2004; L. Lu, I. Manopo, B. P. Leung, H. H. Chng, A. E. Ling, L. L. Chee, E. E. Ooi, S. W. Chan, and J. Kwang, J. Clin. Microbiol. 42:1570-1576, 2004). In the present study, the N195-Sc fusion protein was highly expressed in insect (Sf9) cells infected with a recombinant baculovirus bearing the hybrid gene under the control of a polyhedrin promoter. An IFA based on Sf9 cells producing the fusion protein was standardized with 23 serum samples from patients with SARS, 20 serum samples from patients with autoimmune diseases, and 43 serum samples from healthy blood donors. The detection rates were comparable to those obtained with a commercial SARS-CoV IFA kit (EUROIMMUN, Gross Groenau, Germany) and a conventional IFA performed at the Singapore General Hospital. Our data showed that the newly developed IFA could detect SARS-CoV in 22 of the 23 SARS-CoV-positive serum samples and gave no false-positive results when the sera from patients with autoimmune diseases and healthy individuals were tested. The detection rate was identical to those of the two whole-virus-based IFAs. Thus, the novel N-S fusion antigen-based IFA could be an attractive alternative to present whole-virus-based IFAs for the diagnosis of SARS-CoV infection.     

高频电刀对家兔活体肌肉组织的作用

目的 :探讨高频电刀对肌肉组织结构的作用。方法 :用高频电极在不同输出功率时测定大白家兔活体肌肉组织的电流强度 ,灼伤中心区汽化深度和汽化表面积 ,光镜和电镜下观察创面下 0～ 6mm深度的组织结构变化。结果 :随着电流输出功率的增强 ,肌肉组织的电流强度 ,中心区汽化深度和汽化表面积也随之增加 ,创面深部组织显微和超微结构发生了热凝固性改变 ,损伤程度随着离中心区距离的延长而减弱 ,但在 6mm深处仍有较明显的损伤性改变。结论 :用高频电刀操作时应注意对深部肌肉组织的损伤性作用 ,为减少损伤应注意操作时的电流强度和电灼时间。