嗜人按蚊雌蚊消减cDNA文库的构建及分析

目的 构建嗜人按蚊雌雄蚊差异表达cDNA文库。为进一步筛选、克隆嗜人按蚊雌雄蚊差异新基因奠定基础。方法 以嗜人按蚊为实验模型．分别将雌蚊和雄蚊作为T组和D组．采用抑制消减杂交方法和T／A克隆技术构建嗜人按蚊差异表达cDNA文库。扩增正向消减cDNA文库获得3000余个阳性克隆．随机挑取100个克隆进行PCR扩增，90％的克隆中均有200～1000bp的插入片段。测序显示．有与冈比亚按蚊未知功能基因同源的克隆，去除重复序列，得到72个EST序列．其中40与已知序列具有相似性．32个为新的EST序列。本项研究成功构建了嗜人按蚊雌蚊差异表达cDNA文库，获得了32个新的EST序列。从而为下一步筛选、克隆嗜人按蚊性别差异新基因打下了基础。     

猪囊尾蚴cDNA文库的筛选与重组蛋白的初步鉴定

目的从猪囊尾蚴cDNA文库中免疫学筛选阳性蛋白的编码基因,以期获得囊尾蚴病新的免疫学诊断候选分子。方法免疫学筛选cDNA文库,用PCR法扩增出猪囊尾蚴候选蛋白基因编码序列,T载体连接,鉴定后将其亚克隆入pET28a(+)载体中,经酶切、测序证实正确后,转化入大肠杆菌BL21并用IPTG对该重组菌诱导表达,SDS-PAGE和Western blot方法观察表达结果。结果通过cDNA文库免疫筛选、测序和EXPASY软件分析,其一个684bp ORF DNA序列为新基因(命名为Ts1),录入号为EU009656;将Ts1基因克隆入pET28a(+)载体中诱导表达,可得到一分子量约28.0kDa融合蛋白,并能被囊尾蚴病人血清识别。结论本试验成功筛选、克隆出一个新囊尾蚴编码基因,并在原核细胞中表达,为进一步验证其免疫诊断价值奠定了基础。     

家蝇几丁质酶基因的序列分析、克隆和诱导表达

摘 要：目的 对EST筛选得到的家蝇几丁质酶Ⅰ（MDC Ⅰ）基因进行序列分析,克隆其cDNA序列并在大肠杆菌中表达。 方法 采用EST测序技术从已构建的家蝇幼虫cDNA质粒文库中筛选到MDC Ⅰ基因,对其进行序列测定和分析。以该基因的cDNA文库质粒为模板,通过PCR方法对MDC Ⅰ基因进行扩增,以pET 28a（+）为载体构建重组质粒,再转化到表达宿主菌大肠杆菌BL21（DE3）中,IPTG诱导表达。表达产物通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）进行鉴定。 结果 MDC Ⅰ 基因全长751bp,编码251个氨基酸,理论分子量28.62 kDa;等电点5.78,有一个chitinase 18家族的活性位点。构建了具有正确基因序列的MDC Ⅰ重组表达质粒,重组蛋白在大肠杆菌BL21（DE3）中表达。 结论 MDC Ⅰ基因可在原核表达系统中表达,为进一步研究该蛋白的生物学、免疫学活性奠定了基础。     

刺毛虫毒刺cDNA文库的构建及初步分析

目的构建刺毛虫毒刺的cDNA文库,克隆其毒素编码的基因。方法提取刺毛虫毒刺中的总RNA;使用clontech公司的cDNA文库构建试剂盒进行反转录,长距离PCR方法合成第二条链,酶切纯化后与载体连接,电转化入感受态细胞XL1-Blue,通过抗性筛选后进行菌落PCR鉴定,挑选插入子在300bp以上的单克隆送至测序公司测序。结果成功构建了刺毛虫毒刺cDNA文库,初步鉴定其插入子长度为250～1 000bp。结论刺毛虫毒刺cDNA文库构建成功,并获得大量的编码刺毛虫毒素的全长基因,为研究其致病机制奠定了基础。     

日本血吸虫未知基因的原核表达载体的构建和表达分析

目的构建日本血吸虫未知基因的原核表达载体,研究基因性质. 方法首先将从日本血吸虫成虫cDNA文库中筛选得到的未知基因cDNA JAYL0230亚克隆入原核表达载体pET28a(+)中,IPTG诱导重组蛋白的表达,免疫印记实验检测其免疫性质. 结果成功构建重组原核表达载体pET28a(+)-JAYL0230,并获得稳定表达的融合蛋白,免疫印记实验证明该融合蛋白具有免疫反应性. 结论本实验为进一步深入研究该基因的性质及功能提供了基础.     

猪囊尾蚴一种蛋白抗原的cDNA分子克隆

目的从猪囊尾蚴cDNA文库中克隆某种编码蛋白抗原的基因.方法用脑囊尾蚴病人血清筛选猪囊尾蚴cDNA文库,获得阳性克隆后,经PCR技术扩增噬菌体载体中插入的cDNA片段,并将其亚克隆入pUC18质粒载体中,用双脱氧核苷酸末端终止法测定插入片段的核苷酸序列.测序后与GenBank中的核苷酸序列进行同源性分析.结果经3次筛选,从cDNA文库中克隆出一个阳性克隆,测序后其长度为546 bp,含有一个开放读码框,编码158个氨基酸.同源序列分析结果表明此基因片段与编码猪囊尾蚴的一种免疫原性蛋白基因(NC-9)同源性高达99%.结论本研究克隆出一种编码猪囊尾蚴蛋白抗原的基因.     

乙型肝炎病毒前S1蛋白反式激活蛋白2结合蛋白1基因的克隆及其反式调节基因的筛选

目的 克隆HBV前S1蛋白反式激活蛋白2结合蛋白1(PS1TP2BP1)基因,并筛选与其相互作用的反式激活基因.方法 应用聚合酶链反应(PCR)扩增PS1TP2BP1基因,鉴定正确后再将其亚克隆到真核表达载体pcDNATM3.1/myc-His A上;以真核表达质粒pcDNATM3.1/mycHis A-PS1TP2BP1转染HepG2细胞,构建cDNA消减文库;进行测序及同源性分析.结果 从HepG2细胞来源的cDNA中扩增出PS1TP2BP1基因,并成功进行TA克隆,酶切、测序均正确后,成功构建真核表达重组体.消减文库扩增后得到35个阳性克隆,经菌落PCR分析,得到15个含200～1000 bp插入片段的菌落.对所得片段测序,并进行间源性分析,显示15种已知基因编码蛋白可能是PS1TP2BP1反式激活靶基因.结论 成功克隆PS1TP2BP1,并构建了PS1TP2BP1反式激活基因差异表达的cDNA消减文库,为今后进一步分析、研究病毒蛋白的致病机制奠定了基础.     

应用抑制性消减杂交技术克隆乙型肝炎病毒全S蛋白反式激活基因

目的应用抑制性消减杂交(SSH)技术构建乙型肝炎病毒(HBV)全S蛋白反式激活基因差异表达的cDNA消减文库,克隆HBV全S蛋白反式激活相关基因.方法以HBV全S表达质粒pcDNA3.1(-)-全S转染HepG2细胞,以空载体pcDNA3.1(-)为对照;制备转染后的细胞裂解液,从中提取mRNA并逆转录为cDNA,经RsaI酶切后将实验组cDNA分成两组,分别与两种不同的接头衔接,再与对照组cDNA进行两次消减杂交及两次抑制性PCR,将产物与T/A载体连接,构建cDNA消减文库,并转染大肠杆菌进行文库扩增,随机挑选克隆PCR扩增后进行测序及同源性分析.结果成功构建人HBV全S蛋白反式激活基因差异表达的cD-NA消减文库.文库扩增后得到86个白色克隆,进行菌落PCR分析,均得到100-1000 bp插入片段.挑取35个含有插入片段的阳性克隆测序分析,获得33个已知基因序列,和2个未知基因,通过生物信息学分析获得其全长序列,其中之一命名为全S蛋白反式激活基因1(CSTP1),已在GenBank中注册,注册号:AY553877.未知基因的功能还正在研究中.结论应用SSH技术成功构建了HBV全S反式激活基因差异表达的cDNA消减文库.该文库的建立为进一步阐明HBV全S反式调节的靶基因及致肝病发生的分子生物学机制提供理论依据.     

人胰腺癌抑制消减cDNA文库的构建

目的应用抑制消减杂交技术(SSH)构建胰腺癌和正常胰腺组织间差异表达的抑制消减cDNA文库.方法分别提取胰腺癌(tester)和癌旁正常胰腺组织(driver)中的总RNA和mRNA,合成双链cDNA,经Rsa Ⅰ酶切后,将胰腺癌双链cDNA分为两组,分别加上不同的接头,再与正常胰腺组织cDNA进行两次消减杂交及两次抑制性PCR,分离出胰腺癌差异表达基因的cDNA片段.将该差异表达片段克隆至T/A载体,并转化大肠杆菌TOP 10F',经蓝白斑筛选后,再用PCR方法筛选阳性克隆,从而构建胰腺癌抑制消减cDNA文库.结果文库扩增后得到257个白色克隆,随机挑取50个阳性克隆进行PCR扩增分析,其中47个克隆有插入片段,克隆阳性率为94%,片段大小主要集中在300～600bp之间.结论成功构建了人胰腺癌抑制消减cDNA文库,为进一步筛选、克隆胰腺癌特异性表达基因奠定了基础.     

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.     

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.     

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.     

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.