糖尿病性膀胱病逼尿肌中SCFmRNA和SCF蛋白的表达

目的：检测DCP逼尿肌中SCF表达水平,探讨SCF基因表达与DCP关系及其发病机制。方法：按1：2病例对照研究,采用链脲佐菌素（STZ）及尿动力学检测成功建立DCP豚鼠20只为实验组,并以同质豚鼠40为对照组,应用RT-PCR和Western-blotting方法分别检测各组膀胱逼尿肌中SCF mRNA、SCF蛋白的表达。结果：DCP豚鼠组织中SCF mRNA表达与正常对照组比较无明显显著差异（P〉0.05）,DCP豚鼠组织中SCF蛋白表达明显低于正常对照组（P〈0.01）。结论：DCP组织中SCF蛋白表达减少与SCF基因翻译水平异常有关,因此高血糖环境下SCF基因表达异常可能是DCP的发病机制之一。     

豚鼠膀胱内Cajal样间质细胞的分布情况研究

目的:观察Cajal样间质细胞(ICCs)在成年豚鼠膀胱的分布情况.方法:取5只成年豚鼠膀胱,制作全层冰冻切片,行ICCs特异性标志物c-kit免疫荧光染色,按粘膜层、粘膜下层和肌层进行统计分析.结果:豚鼠膀胱内可见c-kit免疫阳性细胞,胞体呈梭形,两端伸出长的突起,其形态与肠壁肌层Cajal细胞相似.且肌层和粘膜下层多于粘膜层.结论:豚鼠膀胱存在Cajal样间质细胞,并在肌层高表达,可能参与膀胱自主节律性运动的调控,调节逼尿肌的运动,为"神经-Cajal样间质细胞-肌肉"单元的形成提供组织学基础.     

膀胱Cajal样细胞的研究现状与展望

Cajal间质细胞(ICCs)是胃肠道的起搏者,在消化系统中具有重要的起搏功能.目前在膀胱中发现了形态学和免疫学上和ICCs相似的细胞,被称为膀胱Cajal样细胞.这类细胞既具有某些起搏细胞的特征,同时又与膀胱逼尿肌细胞紧密相连.这类细胞在膀胱活动中所起的作用就成为广大科研人员关注的问题,本文就膀胱Cajal样细胞的结构、形态、分布特点及其在信号传导中的作用进行了综述.     

糖尿病大鼠膀胱和骶髓背根神经节中NGF的表达与尿流动力学改变的研究

目的：探讨糖尿病大鼠膀胱与骶髓背根神经节（DRG）中神经生长因子（NGF）的表达与尿流动力学改变。方法：建立糖尿病大鼠模型10只,对照组10只,应用酶联免疫吸附试验（ELISA）法,分别检测大鼠膀胱组织及骶髓DRG中NGF的变化情况,结合代谢笼及尿流动力学改变,探讨糖尿病膀胱病变的可能发病机制。结果：造模12周后,糖尿病大鼠膀胱容量较正常对照组明显增大（1.47±0.28vs0.71±0.12,p〈0.05）,残余尿量明显增多（0.52±0.18vs0.07±0.08,p〈0.01）,排尿效率明显下降,膀胱及骶髓DRG中NGF表达水平明显降低。结论：NGF在糖尿病大鼠膀胱和骶髓背根神经节中低表达,在糖尿病膀胱病变中发挥着重要作用。     

糖尿病大鼠膀胱和骶髓背根神经节中NGF 的表达与尿流动力学 改变的研究

目的:探讨糖尿病大鼠膀胱与骶髓背根神经节(DRG)中神经生长因子(NGF)的表达与尿流动力学改变。方法:建立糖尿病大鼠模型10只,对照组10只,应用酶联免疫吸附试验(ELISA)法,分别检测大鼠膀胱组织及骶髓DRG中NGF的变化情况,结合代谢笼及尿流动力学改变,探讨糖尿病膀胱病变的可能发病机制。结果:造模12周后,糖尿病大鼠膀胱容量较正常对照组明显增大(1.47±0.28vs0.71±0.12,p<0.05),残余尿量明显增多(0.52±0.18vs0.07±0.08,p<0.01),排尿效率明显下降,膀胱及骶髓DRG中NGF表达水平明显降低。结论:NGF在糖尿病大鼠膀胱和骶髓背根神经节中低表达,在糖尿病膀胱病变中发挥着重要作用。     

神经生长因子受体Trka在糖尿病大鼠膀胱和腰骶背根神经节的表达

目的研究糖尿病大鼠膀胱组织及背根神经节中神经生长因子受体Trka的表达变化及意义。方法建立糖尿病大鼠模型20只,以15只正常大鼠为对照,应用免疫组化方法,分别检测大鼠膀胱组织及背根神经节中Trka的表达情况。结果无论是在膀胱组织还是在背根神经节中,糖尿病组Trka的表达均低于对照组,差异有统计学意义（P〈0.01）。结论神经生长因子受体Trka的表达降低与糖尿病膀胱病变的发生有关。     

胰岛素受体底物家族与Ⅱ型糖尿病关系性的研究进展

胰岛素受体底物分子(IRS)是调节胰岛素信号通路的关键物质,在维持细胞生长,分裂和代谢中起着重要作用。目前已发现的家族成员有四个(IRS-1、IRS-2、IRS-3、IRS-4)。目前研究表明,糖尿病的发生与之密切相关:胰岛素信号通路与其他信号通路发生交叉发生干扰,从而导致胰岛素抵抗,引发Ⅱ型糖尿病;IRS蛋白的结构、表达水平异常导致胰岛素信号的中断或减弱,并表现为胰岛素抵抗;四种IRS分子表达的不平衡,致使胰岛素分泌调节的稳态被破坏也可能是糖尿病发病的原因之一。Fox蛋白家族是动物细胞内的一类转录因子,与细胞代谢密切相关。Fox蛋白靶点有可能作为研究治疗糖尿病方法的一种新思路。     

β-catenin和WISP-1在糖尿病大鼠心肌中的表达

目的观察Wnt信号通路中β-catenin及其下游靶基因WISP～1在糖尿病大鼠心肌组织中的表达,分析Wnt/β-catenin信号通路在糖尿病大鼠心肌损伤中的作用。方法雄性SD大鼠随机分为正常对照组（Control Group）和糖尿病模型组（DMGroup）,腹腔注射STZ55mg／kg诱导糖尿病大鼠模型,喂养至8周。测定大鼠的空腹血糖、心体比和心肌羟脯氨酸含量;电镜观察心肌超微结构变化,免疫组化法观察心肌组织β-catenin和WISP-1的表达。结果与对照组相比,糖尿病组大鼠空腹血糖水平明显增加,心体比增加,心肌羟脯氨酸含量增高。心肌超微结构显示肌纤维断裂,线粒体呈空泡样改变。心肌β-catenin和WISP-1蛋白表达增加。结论糖尿病大鼠心肌组织β-catenin和其下游靶基因WISP-1表达增加,提示Wnt／β-catenin信号通路的激活参与糖尿病所致的心肌损伤。     

神经节苷脂联合α-硫辛酸治疗糖尿病神经源性膀胱临床观察

目的:观察α-硫辛酸、神经节苷脂联合治疗糖尿病神经源性膀胱的临床疗效。方法:60例2型糖尿病神经源性膀胱患者,随机分为α-硫辛酸治疗对照组、神经节苷脂治疗对照组,联合治疗组,疗程30d,观察症状体征及治疗前后B超膀胱残余尿量症状的变化,比较不同方案的疗效。结果:α-硫辛酸治疗对照组有效率90%,神经节苷脂治疗对照组有效率90%,联合治疗组有效率95%两组间无统计学差异(P>0.05),但3组的治愈率分别为90.0%、50.0%、60.0%,治疗组的治愈率高于两个对照组,有统计学差异(P<0.05)。结论:α-硫辛酸和神经节苷脂联合治疗糖尿病神经源性膀胱有较好的临床疗效,值得临床推广。     

神经节苷脂联合α-硫辛酸治疗糖尿病神经源性膀胱临床观察

目的：观察α-硫辛酸、神经节苷脂联合治疗糖尿病神经源性膀胱的临床疗效。方法：60例2型糖尿病神经源性膀胱患者,随机分为α-硫辛酸治疗对照组、神经节苷脂治疗对照组,联合治疗组,疗程30d,观察症状体征及治疗前后B超膀胱残余尿量症状的变化,比较不同方案的疗效。结果：α-硫辛酸治疗对照组有效率90％,神经节苷脂治疗对照组有效率90％,联合治疗组有效率95％两组间无统计学差异（P〉0．05）,但3组的治愈率分别为90．0％、50．0％、60．0%,治疗组的治愈率高于两个对照组,有统计学差异（P〈0．05）。结论：α-硫辛酸和神经节苷脂联合治疗糖尿病神经源性膀胱有较好的临床疗效,值得临床推广。     

Inhibitors of Ribonucleic Acid Synthesis in Saccharomyces cerevisiae: Decay Rate of Messenger Ribonucleic Acid

Daunomycin and ethidium bromide, two deoxyribonucleic acid-intercalating drugs, inhibit ribonucleic acid (RNA) and protein synthesis in Saccharomyces cerevisiae. Both agents rapidly curtail uptake of radioactive adenine, whereas the kinetics of radioactive leucine uptake after drug addition are consistent with translation of a pool of exponentially decaying messenger RNA. Messenger RNA half-life determinations from these experiments gave identical results over a range of drug concentrations; this value is 21 +/- 4 min at 30 C. In a temperature-sensitive mutant in which RNA synthesis is curtailed at the nonpermissive temperature, a similar half-life for messenger RNA decay is found both in the absence and in the presence of either drug. This indicates that at the concentrations used in this study, neither daunomycin nor ethidium bromide has an appreciable direct effect on translation and do not increase the lability of messenger RNA.     

Continued Expression of the Ribonucleic Acid Control Gene During Inhibition of Escherichia coli Ribonucleic Acid and Protein Synthesis

The effect of the ribonucleic acid (RNA) control (RC) gene on the biosynthesis of viral RNA has been examined in an RC(str) and an RC(rel) host infected with R17 RNA bacteriophage under conditions in which host RNA and protein synthesis were inhibited by the addition of rifampicin. Methionine and isoleucine starvation depressed viral RNA biosynthesis in an RC(str) host but not in an RC(rel) host. However, histidine starvation had little effect on viral RNA and protein synthesis in both RC(str) and RC(rel) cells, although it had a marked effect on host protein and RNA synthesis in an RC(str) host. Chloramphenicol relieved the effect of amino acid starvation on viral RNA synthesis in an RC(str) host. It is concluded that stringent control of viral RNA biosynthesis does not require the continued biosynthesis of the RC gene product (RNA or protein) and that a preformed RC gene product can regulate the biosynthesis of the exogenous RNA. It is suggested that the amino acid dependence of viral RNA biosynthesis is due to its obligatory coupling with the translation of the viral coat protein which lacks histidine. It may be inferred that the amino acid requirement of bacterial RNA is due to its coupling with the translation of a host-specific protein (other than the RC gene product) which requires a full complement of amino acids. Since chloramphenicol is known to permit ribosome movement in the absence of protein synthesis, it is suggested that ribosome movement along the nascent RNA chain is a sufficient condition for the continuation of RNA synthesis.     

Adenylate-Rich Sequences in Vesicular Stomatitis Virus Messenger Ribonucleic Acid

Vesicular stomatitis virus (VSV)-specific messenger ribonucleic acid (mRNA) species contain sequences of adenylate-rich RNA which are more heterogeneous in their migration through sodium dodecyl sulfate-polyacrylamide gels than the corresponding fractions from HeLa cell mRNA. VSV virion RNA contains no adenylaterich sequences. The possible role of such sequences in the mRNA species of a cytoplasmically replicating virus is discussed.     

Heterogeneity of the Stability of Messenger Ribonucleic Acid in Salmonella typhimurium

Cells of Salmonella typhimurium strain SL 282, deflagellated by mechanical shear, regenerated their flagella in the absence of tryptophan, an amino acid required for growth but not found in flagellin. Ribonucleic acid (RNA) synthesis was severely inhibited by tryptophan starvation. These findings suggested that the messenger RNA (mRNA) for flagellin might be stable. Actinomycin D was used to inhibit RNA synthesis in ethylenediaminetetraacetate-treated bacteria. The introduction of an F(lac) episome into strain SL 282 permitted the simultaneous study of the synthesis of flagellin, beta-galactosidase, and total protein. In the actinomycin-treated bacteria protein and beta-galactosidase syntheses were inhibited by 90%, whereas flagellin synthesis was unaffected. We conclude that the mRNA for flagellin synthesis is stable and that species of mRNA vary with respect to metabolic stability in S. typhimurium.     

Stable Messenger Ribonucleic Acid and Germination of Myxococcus xanthus Microcysts

We have examined germination, protein synthesis and ribonucleic acid (RNA) synthesis by microcysts of the fruiting myxobacterium Myxococcus xanthus. The morphological aspects of microcyst formation were completed at about 2 hr after induction had begun. In such microcysts, germination, RNA synthesis, and protein synthesis were inhibited by actinomycin D (Act D). At 6 hr after induction, germination and protein synthesis had become relatively resistant to Act D, whereas RNA synthesis was inhibited by about 95%. Experiments with (3)H-Act D indicated that the deoxyribonucleic acids of both young and old microcysts bind Act D equally. Resistance of germination to Act D was acquired 4 to 5 hr after induction of microcyst formation, and was due to an Act D-sensitive synthesis at that time. Vegetative cells and microcysts were pulsed with uridine-5-(3)H and chased for 60 min; the RNA was extracted and analyzed by means of sucrose density gradient centrifugation and gel electrophoresis. Both microcysts and vegetative cells were found to contain grossly the same types of RNA in the same proportions. RNA pulse-labeled in microcysts was more stable than that in vegetative cells. No particular portions of the microcyst pulse-labeled RNA were selectively stabilized. These data indicate that a stable messenger RNA required for synthesis of germination proteins was synthesized during microcyst formation. This may be the same as the RNA synthesized 4 to 5 hr after initiation of microcyst formation. We suggest that the existence of such stable messenger RNA in microcysts is consistent with the limited biosynthetic activities of such cells.     

Messenger Ribonucleic Acid of Dormant Spores of Bacillus subtilis

Evidence of the presence of messenger ribonucleic acid (mRNA) in dormant spores of Bacillus subtilis has been obtained. The bulk RNA from spores was isolated and labeled in vitro with tritiated dimethyl sulfate. The spore RNA hybridized to 2.4 to 3.2% of the B. subtilis genome. The RNA hybridized to both the complementary heavy and light fractions of deoxyribonucleic acid (DNA). Bulk RNA from log-phase cells competed with virtually all the spore RNA for the heavy DNA fraction and with part of the spore RNA for the light DNA fraction. Bulk RNA from stage IV cells in sporulation also competed with all of the spore RNA for the heavy DNA fraction and with essentially all the spore RNA for the light DNA fraction. These results indicate that dormant spores contain mRNA species present in both log-phase cells and stage IV cells of sporulation. The RNA polymerase in the developing forespore must be able to recognize promotor sites for both log-phase and sporulation genes.     

Isolation and Characterization of Adenovirus Messenger Ribonucleic Acid in Productive Infection

Messenger ribonucleic acid (mRNA) from cells productively infected with adenovirus type 2 was isolated by affinity chromatography on polyuridylic acid [poly (U)] bound to Sepharose. At least 90% of the polyadenylic acid [poly (A)]-containing polysomal mRNA was retained by the poly (U) Sepharose and thus separated from more than 95% of the ribosomal RNA and transfer RNA. In these experiments, 65% of the early (3 to 5 hr postinfection) and 85% of the late (14 to 16 hr postinfection) virus-specific RNA was retained by the poly (U) Sepharose. Early in the infection 18%, and late in the infection more than 95%, of the poly (A)-containing fraction, eluted from the poly (U) Sepharose with 90% formamide, was adenovirus-specific, as shown by exhaustive hybridization. Different patterns, containing several distinct species of viral mRNA, were detected early and late in the infectious cycle. No distinct viral mRNA lacking poly (A) was discovered.     

Isolation of Messenger Ribonucleic Acid for Myosin Heavy Chain

A chicken embryonic polysome fraction that contains 50–60 monoribosomes and synthesizes the heavy chains of myosin is separated from other polysomes of smaller sizes by centrifugation through two cycles of discontinuous and continuous sucrose gradients. The unique properties of the polyadenylic acid segment present at the 3′-end of eukaryotic messenger RNA (mRNA) were used to purify the mRNA for myosin heavy chain from the phenol-extracted total RNA obtained from this polysome fraction. The total RNA was filtered thro ugh millipore filters resulting in partition of the riboscmal RNA (rRNA) and mRNA species. This millipore-bound RNA fraction, which consists of the mRNA and some ribosomal RNAs, was eluted from the filters with sodium dodecyl sulfate (SDS). Subsequent chromatography of this fraction on a cellulose column gave two well-separated peaks: an unadsorbed peak of ribosomal RNAs which was eluted with buffers of high ionic strength and an adsorbed peak of mRNA which was eluted only with a buffer of low ionic strength. Polyacrylamide gel electrophoresis of the mRNA peak fraction showed a single band with no detectable amounts of other RNAs, the mRNA migrating slower than 28S rRNA. The product of in vitro translation of the purified mRNA using a homologous cell-free system was identified as the myosin heavy chain by the following criteria: coprecipitation with carrier myosin at low ionic strength; elution properties on DEAE-cellulose column; and comigration with the heavy chain in polyacrylamide gel electrophoresis. In order to demonstrate the fidelity of translation of the mRNA, ¹⁴C-labeled products of the in vitro translation were copurified with unlabeled myosin heavy chains added as a carrier. The mixture of polypeptides was then cleaved with CNBr and the resulting peptides were separated by molecular sieving. The correlation between the radioactivity and the UV absorbance in the separated peptides indicates that total synthesis of the myosin heavy chain was achieved.     

Ribonucleic Acid Synthesis in Cells Infected with Herpes Simplex Virus VI. Polyadenylic Acid Sequences in Viral Messenger Ribonucleic Acid

Evidence is presented by use of radiolabeling and pancreatic and T1 ribonuclease digestion that some of the ribonucleic acid specified by herpes simplex virus contains polyadenylic acid sequences. The polyadenylic sequences are not transcribed from viral DNA.