编码大鼠血管紧张素转换酶短发夹环RNA质粒的构建与鉴定

目的构建编码大鼠ACE mRNA的shRNA真核表达载体质粒,为利用基因沉默技术从转录后水平进行高血压治疗的研究做准备。方法根据大鼠ACE mRNA序列设计并合成shRNA寡核苷酸片段,退火形成双链并克隆进入载体pGenesil-1,并进行酶切鉴定和测序。结果酶切证明构建的shRNA已插入载体,经测序证明与设计的相同,获得大鼠ACE的shRNA表达载体质粒。结论构建的编码大鼠ACE mRNA的shRNA真核表达载体可进入哺乳动物细胞内表达短发夹RNA,经Dicer酶裂解成si R-NA并降解靶基因mRNA,而达到基因干扰的作用。为利用其进行自发性高血压大鼠的降压治疗研究奠定了基础。     

靶向大鼠Caveolin-1基因的短发夹RNA表达载体的构建

目的构建靶向大鼠caveolin-1基因的shRNA表达载体。方法化学合成靶向caveolin-1的单核苷酸链,经退火成双链。将退火得到的双链DNA克隆至表达载体pLL3.7中得到重组质粒,经限制性内切酶酶切、DNA测序进行鉴定。结果通过限制性内切酶酶切、DNA测序证实,成功构建大鼠pLL3.7-cav-1表达载体。结论成功构建了靶向大鼠caveolin-1的shRNA表达载体,为以后进行caveolin-1与ALI/ARDS的相关研究奠定了基础。     

大鼠源肺孢子菌p55基因片段真核表达质粒的构建及表达

目的构建大鼠源肺孢子菌抗原p55基因片段真核表达质粒,并研究该质粒在真核细胞COS-7中的有效表达。方法以含有p55全长基因的质粒为模板,通过PCR扩增p55基因片段,克隆至pGEM-T载体中,经酶切后再将p55基因重组至真核表达载体pcDNA3.1(+)中,构建重组真核表达质粒pcDNA3.1(+)-582,经限制性内切酶酶切分析及测序鉴定正确后,应用脂质体转染技术转染入COS-7细胞,RT-PCR检测其基因转录情况,SDS-PAGE鉴定其表达相应的目的蛋白质情况。结果成功扩增了p55基因片段,酶切和测序证明正确构建了重组真核表达质粒pcDNA3.1(+)-582,RT-PCR和SDS-PAGE方法证实该片段能在COS-7细胞中有效表达目的蛋白质。结论成功构建了大鼠源肺孢子菌p55基因片段的真核表达质粒载体,并在COS-7细胞中表达,为进一步进行核酸疫苗的研究奠定了基础。     

CTGF靶向RNA干扰重组体的构建及序列分析

目的:利用pEGFP质粒载体构建介导结缔组织生长因子(CTGF)短发夹RNA(shorthairpinRNA,shRNA)表达的质粒.方法:分别设计3对有小发夹结构的两条DNA序列,经退火成互补双链,再克隆至带有U6启动子的质粒载体pEGFP中,构建重组体,转化DH5α菌株,提取质粒行酶切鉴定后,进行测序分析.结果:CTGF的sRNA片段被成功克隆到pEGFP质粒载体中,3个重组质粒shRNA编码序列与设计的片段完全一致,经酶切与测序证实构建成功.结论:成功构建了能表达CTGFshRNA的重组体,为下一步探索肝纤维化基因治疗的新途径打好基础.     

重组结缔组织生长因子shRNA质粒的构建及其对肝星状细胞基因表达的影响

[目的]构建同时干扰大鼠结缔组织生长因子(CTGF)2个不同基因位点的shRNA质粒,并将其转染肝星状细胞(HSC),研究其对CTGF基因表达的影响。[方法]针对大鼠CTGF mRNA靶向序列设计并合成2对DNA模版序列,用PCR的方法将2条CTGF靶向特异性的shRNA分别链接到质粒pGenesil1.2载体的U6启动子和H1启动子。将构建的干扰质粒以阳离子脂质体法转染HSC-T6细胞,应用RT-PCR及Western Blot检测CTGF的表达。[结果]成功构建CTGF shRNA重组质粒;通过RT-PCR和Western Blot分析发现干扰质粒组的CTGF mRNA与蛋白表达水平明显下降(P0.05)。[结论]重组CTGF shRNA能有效抑制HSC中CTGF的表达。     

干扰Fas受体表达的串联shRNA表达载体的构建

目的:利用pEGFP6-1和pGenesil-1质粒构建针对Fas的2个短发夹RNA(short hairpin RNA,shRNA)串联表达的栽体．方法:设计表达2个shRNA结构的互补DNA序列,经退火成双链,分别克隆至带有U6启动子的质粒载体pEGFP6-1和pGenesil-1中,构建重组质粒,转化大肠杆菌DH5α菌株,扩增,提取质粒,酶切鉴定后测序分析．分别用SacI SalI双酶切重组质粒,胶回收酶切pEGFP6- 1-siFas1大片段和酶切pGenesil-1-siFas2小片段,T4 DNA Ligase连接酶切大、小片段,得到pEGFP6-1-siFas1 siFas2重组质粒．转化感受态细胞DH5α,扩增,提取串联重组质粒进行酶切鉴定．结果:成功构建靶向Fas的2个shRNA串联重组质粒载体pEGFP6-1-siFas1 siFas2．酶切鉴定和测序分析重组质粒,shRNA编码序列与设计的片段完全一致,经酶切凝胶电泳证实载体构建成功．结论:表达2个靶向Fas的shRNA表达框成功构建在一个重组质粒载体上．     

靶向表皮生长因子受体shRNA质粒表达载体的构建和鉴定

目的构建靶向表皮生长因子受体（EGFR）的短发卡状RNA（shRNA）质粒表达载体并进行鉴定。方法设计两个小分子干扰RNA（siRNA）序列，体外合成DNA模板引物，与Pgenesil-1质粒构建成编码shRNA的表达载体，进行酶切鉴定和测序，再转染人大肠癌LoVo细胞，进行荧光摄像和G418抗性筛选。结果构建的质粒表达载体完全符合设计要求，转染成功的细胞在荧光显微镜下显示为绿色，G418可以筛选出阳性克隆。结论成功构建了编码EGFR—shRNA的质粒表达载体，并可以进行稳定筛选。     

靶向SET的shRNA真核表达质粒的构建及鉴定

目的:针对PP2A内源性抑制剂SET基因的不同部位,构建靶向SET的shRNA真核表达质粒,鉴定并筛选出最佳抑制效率的表达质粒.方法:针对SET基因的不同部位设计4对短发卡RNA(shRNA)的寡核苷酸片段,克隆到真核表达载体pGPU6中,构建靶向SET的shRNA真核表达质粒pGPU6/GFP/Neo-SET-shR...     

正反义人端粒酶RNA组分(hTR)基因真核表达载体的构建

目的构建正义和反义端粒酶RNA组分((human telomerase RNA components,hTR)基因真核表达载体.方法用MluⅠ和SalⅠ从pGRN83质粒上切下约579bp的hTR cDNA片段,分别定向连入pcl-neo的Mlu Ⅰ/Sal Ⅰ和MluⅠ/Xho Ⅰ酶切位点上,即构建成了hTR的正反义表达载体,并经酶切鉴定和测序确认.结果经酶切鉴定和测序证明,所构建的正反义hTR真核表达载体与设计完全一致.结论成功构建了人端粒酶RNA的正反义真核表达载体,为进一步研究正反义hTR基因转染对胃癌细胞端粒酶及生物学行为的影响奠定了基础.     

构建shRNA真核表达载体抑制人COX-2的表达

目的构建编码人环氧合酶-2(COX-2)mRNA的shRNA真核表达载体质粒,特异性抑制人COX-2的表达。方法以人COX-2mRNA编码区中2条不同序列作为RNA干扰靶点,分别构建2个shRNA真核表达载体质粒,WBH1和WBH2,进行酶切鉴定和测序。用脂质体转染人胃癌细胞系SGC-7901,RT-PCR和Western blot分别从mRNA和蛋白质水平检测抑制效果。结果WBH-1高效特异地抑制了人COX-2的表达,抑制率达70.42%;而WBH-2未产生抑制效果。结论通过构建COX-2的shRNA真核表达载体导入细胞可以有效地抑制人胃癌细胞中COX-2的表达,其抑制效果与靶点的选择高度相关。     

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.