3种截短的泡球蚴Em18基因原核表达质粒的构建、表达及鉴定

目的构建3种截短的泡球蚴18(Em18)基因的原核表达质粒,获得高效表达、有生物活性的3种重组蛋白,并对其进行初步鉴定。方法DNAman软件设计引物,PCR法扩增并构建3种截短的pET41a-Em18.1、Em18.2和Em18.3原核表达质粒,测序鉴定插入序列正确性;IPTG诱导、表达和纯化rEm18.1-GST、rEm18.2-GST和rEm18.3-GST重组蛋白,SDS-PAGE电泳及Western blot进行初步鉴定。结果成功构建了3种截短的pET41a-Em18.1、Em18.2和Em18.3重组表达质粒;SDS-PAGE检测表明rEm18.1-GST、rEm18.2-GST、rEm18.3-GST重组蛋白得到成功表达,在分子质量单位为41、45.5和45.5ku处有表达条带;Western blot显示3种重组蛋白均能被AE病人血清识别。结论成功构建了截短的pET41a-Em18.1、pET41a-Em18.2和pET41a-Em18.3原核表达质粒,表达的3种重组蛋白均具有良好的抗原性,为Em18抗原表位分析奠定了基础。     

泡球蚴Em18重组蛋白的表达及其抗原性检测的研究

目的 构建泡球蚴18(Em18)基因的原核表达质粒，获得高效表达、有生物活性的Em18重组蛋白，为包虫病诊断试剂的研制奠定基础。方法 用DNAman软件设计引物，分别在引物5’端和3’端添加EcoRⅠ和XhoⅠ酶切位点，以pMD18-T／Em18原核表达质粒为模板，PCR扩增Em18基因片断，经酶切，克隆人原核表达载体pET-41a( )，构建原核表达质粒pET41a-Em18；转化大肠埃希菌BL21(DE3)，酶切、PCR及测序鉴定其插入序列的正确性。经IPTG诱导表达rEm18-GST重组蛋白和GST重组蛋白，用谷光甘肽-Sepharose 4B亲合层析柱分别进行纯化，通过SDS-PAGE和Western blot试验分析鉴定。结果 测序表明构建的pET41a-Em18原核表达质粒均为正确连接，插入Em18基因片断为486bp。SDS-PAGE检测表明Em18基因以rEm18-GST重组蛋白的方式得到成功表达，在相对分子质量单位50ku处有表达条带；Westernblot分析显示，rEm18-GST重组蛋白能被泡型棘球蚴病人阳性血清识别，具有良好的抗原性。结论 成功构建了pET41a-Em18原核表达质粒，获得的rEm18-GST重组蛋白具有生物活性和抗原性，有望应用于泡型包虫病诊断试剂的研制。     

大鼠Sirt1基因原核表达质粒的构建及融合蛋白表达

目的构建大鼠Sirt1基因重组原核表达质粒pET41-Sirt1,表达其重组蛋白,为进一步研究Sirt1在哺乳动物细胞内的作用奠定基础。方法根据GenBank中大鼠Sirt1基因序列设计引物,用RT-PCR扩增得到含BamHI/XhoI酶切位点的Sirt1片段,克隆至pGEM-Teasy载体后亚克隆至原核表达载体pET41,测序鉴定后,转化宿主菌进行表达、蛋白纯化,SDS-PAGE鉴定。结果从大鼠脑的mRNA中扩增出特异Sirt1基因片段长506bp,经酶切鉴定及DNA序列测定,证实pET41-Sirt1重组质粒构建正确,表达融合蛋白分子量约为48kD。结论成功构建重组原核表达质粒pET41-Sirt1,并能表达融合蛋白,其分子量大小与预期一致。     

弓形虫致密颗粒蛋白GRA8截短型片段在原核中的表达

目的 构建弓形虫GRA8原核重组表达质粒，分析其表达状况。 方法 采用PCR技术扩增GRA8及其截短型片段的基因序列，经克隆后，亚克隆至原核表达载体中，构建GRA8及其截短型片段的重组表达质粒，分析GRA8的表达；将各重组菌进行诱导，将裂解上清用谷胱甘肽-琼脂糖亲合层析法和SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)纯化目的蛋白，免疫印迹法(Western blotting)分析纯化蛋白的活性。 结果 GRA8基因被正确插入原核表达质粒中，原核重组表达质粒在大肠埃希菌JM109中表达GRA8的水平低，几乎无完整GRA8的表达，截短型GRA8经谷胱甘肽-琼脂糖亲合层析法和SDS-PAGE获得纯化。纯化的截短型GRA8能被弓形虫感染兔血清识别。 结论 GRA8的原核重组表达质粒表达GRA8的水平低，纯化的截短型GRA8具一定的抗原反应性。     

GⅡ.2型诺如病毒VP1蛋白原核表达及蛋白纯化

目的利用原核表达系统,表达了GⅡ.2型诺如病毒VP1蛋白,优化诱导条件并进行蛋白的纯化。方法扩增诺如病毒的VP1基因,克隆至pET32a(+)载体,构建重组质粒pET32a-VP1。将pET32a-VP1转化至大肠埃希菌BL21(DE3),加入IPTG进行诱导表达并优化诱导条件。利用His标签镍离子蛋白纯化柱纯化表达蛋白,SDS-PAGE电泳鉴定蛋白纯度。结果成功扩增大小为1 659 bp的诺如病毒VP1基因。PCR检测重组质粒pET32a-VP1构建成功。将重组质粒转化至BL21(DE3),IPTG诱导表达70×10~3的VP1重组蛋白,优化的最佳诱导表达条件为37℃,0.6 mmol/L IPTG诱导5 h。重组蛋白以包涵体的形式表达,并SDS-PAGE鉴定镍柱纯化产物为单一电泳条带的目的蛋白。结论利用原核表达系统成功构建了重组质粒pET32a-VP1,并表达纯化了诺如病毒VP1重组蛋白,为单克隆及多克隆抗体的制备、检测试剂盒以及新型疫苗的研发奠定了基础。     

弓形虫Rhomboid-1蛋白基因的克隆及原核表达

目的克隆并原核表达刚地弓形虫（Toxoplasmagondii）Rhomboid-1（TgROMl）蛋白。方法收集、纯化弓形虫速殖子,用Trizol法提取总RNA,应用RTPCR技术扩增TgROMl基因,回收的PCR产物与pMDl8-T载体连接,构建重组克隆质粒pMDl8-T-TgROMl。将重组克隆质粒亚克隆至原核表达载体pGEX一4T—l中,构建重组表达质粒pGEX-4Tl-TgR（）M1并转化至Rosetta感受态,用IPTG诱导表达,表达产物进行SDS-PAGE和Westernblot分析。结果成功克隆了643bp的TgROMl基因,双酶切鉴定重组表达质粒pGEX-4T-1-TgROMl构建正确。SDS-PAGE检测重组表达质粒表达的TgROMl蛋白分子质量约为48ku,Westernblot检测表明该蛋白能被鼠抗弓形虫血清识别。结论成功克隆了弓形虫ROMl基因并原核表达了具有反应原性的重组TgROMl蛋白,为该蛋白的功能研究奠定了基础。     

EM18-GST原核表达载体的构建及空间结构的生物信息学分析

目的构建GST—EMl8原核表达质粒,优化EM18-GST重组蛋白诱导表达条件,通过生物信息学预测EM18蛋白的空间结构。方法以pMDl8T／Eml8为模板,扩增EMl8基因的CDS区,构建pGEX一3X—EM18,设计不同诱导表达条件表达EM18GST蛋白。通过各种在线网站对EM18蛋门空间结构进行生物信息学预测。结果成功构建GST—EMl8原核表达质粒,以1mmol／LIPTG于37℃诱导4h,蛋白表达较好;生物信息学预测EM18蛋白N端为无规卷曲,之后紧连两个α螺旋,C末端为无规巷曲和较短的片层结构。结论成功构建了GSTEM18原核表达质粒,表达的EM18蛋白含有无规则卷曲,可能是抗原表位所在位置。     

HIV-1 Vif的克隆、表达与活性检测

目的克隆HIV-1Vif基因,构建原核表达质粒,进行蛋白的表达及其生物学活性的检测。方法 PCR扩增Vif基因,并将其克隆到原核表达载体pET28a(+)中,构建原核表达质粒pET28a(+)/Vif,进行双酶切及测序鉴定。获得的阳性质粒转化大肠杆菌BL21(DE3)中进行表达,对表达产物进行SDS-PAGE电泳和Western blot检测分析,利用亲和层析方法纯化Vif蛋白。利用Pull-Down方法检测HIV-1Vif与SH3(HCK)特异性结合活性。结果通过酶切和测序,结果表明重组质粒pET28a(+)/Vif构建正确。SDS-PAGE和Western blot结果鉴定了原核表达的Vif重组蛋白大小正确。纯化了蛋白Vif、SH3和GST。GST pull-down试验说明Vif和SH3蛋白具有体外特异性结合活性。结论成功地克隆、表达和纯化了Vif蛋白,Vif与SH3蛋白具有结合活性,为进一步研究针对Vif与SH3结合的药物筛选提供实验依据。     

柔嫩艾美尔球虫EGF-like结构域基因的克隆及原核表达

目的克隆并原核表达柔嫩艾美尔球虫（Eimeriatenella）微线蛋白4（EtMIc4）的EGF-like结构域。方法收集并纯化柔嫩艾美尔球虫子孢子,用Trizol法提取总RNA,并反转录成cDNA,利用RT-PCR技术扩增EtMIC4EGF-like基因;回收PCR产物,与pMDl8-T载体连接,构建重组克隆质粒pMDl8-T-EGF-like,然后亚克隆至原核表达载体pET-30a中,构建重组表达质粒pET-30a-EGF-like并转化至Transetta感受态,经IPTG诱导后进行SDS-PAGE和Westernblot分析。结果成功克隆了EtMIC4EGF-like（390bp）基因,双酶切鉴定重组表达质粒pET-30a-EGF-like构建正确。SDS-PAGE分析重组EGF-like蛋白的分子质量单位约为30ku,Westernblot显示该蛋白能被鸡抗柔嫩艾美尔球虫血清识别。结论成功构建了pET-30a-EGFlike原核表达质粒,并证明其原核表达产物EGF-like蛋白具有反应原性,为该蛋白的功能研究奠定了基础。     

空肠弯曲菌CadF蛋白的原核表达与产物分析

目的构建空肠弯曲菌cadF基因重组表达质粒pET30a(+)-cadF,分析其在大肠埃希菌中的表达情况及其融合蛋白的抗原性。方法用PCR方法扩增cadF基因,构建重组克隆质粒和表达质粒,经菌落PCR、双酶切和测序鉴定后在E.coli(DE3)原核表达系统中诱导表达,SDS-PAGE和飞行时间质谱鉴定表达蛋白,Western blot分析其抗原性。结果含重组表达载体pET-30a(+)-cadF中的cadF基因序列经测序证实与出发菌株cadF基因序列100%同源,并成功诱导表达CadF蛋白,Westernblot显示该CadF融合蛋白能被抗空肠弯曲菌多克隆兔血清识别。结论成功构建了空肠弯曲菌cadF基因重组表达载体,表达产物具有抗原性。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.