树Qu实验性肝癌发生过程p53基因的变化

目的探讨由人乙型肝炎病毒(HBV)和黄曲霉毒素B1(AFB1)诱发的树鼩肝细胞癌变过程,p53基因的表达及变化.方法将树鼩分为四组A组HBV+AFB1,B组只感染HBV;C组只摄入AFB1;D组作空白对照.定期肝活检,用免疫组织化学、分子生物学等技术对实验树鼩肝及肿瘤组织进行检测.结果 (1)接受HBV及AFB1双因素的A组,肝细胞癌(HCC)发生率(66.7%)明显高于只接受HBV的B组或AFB1的C组(30%),而且HCC的平均发生时间也明显早于C组,(120.0±16.6)周与(153.3±5.8)周,t=3.336,P＜0.01.(2)在第75周前各组动物肝均未检出突变的p53蛋白.(3)105周时,A组p53蛋白表达率为78.6%,B组为60%,C组为71.4%,D组为10%(x2≥5.03,P＜0.05).在A、C组检出p53基因异常带.(4)树鼩肝癌p53基因突变点分别位于2 7 5、7 8及1 3密码子;其野生型p 5 3基因的核苷酸及氨基酸序列与人的p 5 3基因的核苷酸及氨基酸序列的同源性分别为91.7%、93.4%.结论再次证实HBV和AFB1有协同致肝癌作用;突变的p53蛋白出现于肝细胞发生癌变之前,p 5 3基因的突变促进了肝癌的发生和演进.HBV可能协同AFB1致p 5 3基因突变.     

HBV与AFB1诱发树鼩肝癌前病变过程中癌基因异常表达的实验研究

动态观察HBV与AFB1诱发树鼩肝细胞癌(HCC)病变过程肝癌前病变γ-谷氨酰转肽酶阳性肝细胞灶(GGT阳性灶)和胰岛素样生长因子Ⅱ(IGF-Ⅱ)、p21及p53表达情况,探讨HCC发生的可能机制。实验动物分4组:A组血清HBV阳性和摄入AFB1;B组HBV阳性;C组摄入AFB1;D组空白对照。结果:(1)各实验组肝癌前病变GGT阳性灶数量、大小均明显高于空白对照组(P<0.05),A组明显大于B、C组(P<0.05);(2)实验第15周,即有IGF-Ⅱ阳性表达,在第45周阳性率明显高于第75周(P<0.05);(3)A、B两组动物肝组织中HBsAg阳性率高达92.1％,首次在树鼩肝组织中检出HBxAg,且阳性率达86.5％。提示:HBV与AFB1协同致树鼩HCC;HCC发生早期就有癌基因IGF-Ⅱ的异常表达。     

肝细胞癌肿瘤抑制基因p53过度表达及点突变的研究

目的检测重庆地区肝细胞癌 p53突变发生率,并进一步探讨 p53突变与肝细胞癌临床病理及相关危险因素的关系.方法应用一种敏感的 ARF 免疫组化和 PCR、银染 PCR-SSCP 方法检测本地区38例肝细胞癌(HCC)组织中肿瘤抑制基因p53的过度表达及点突变.结果 16例有P53蛋白过度表达(41.2%),7例有 p53基因249位密码子点突变(18.4%),2例249位密码子外第7外显子点突变.9例 p53基因有突变的肝癌中8例 P53蛋白阳性,两者符合率为88.9%.p53基因蛋白过度表达和点突变与 HCC 分化和转移有关.本组 HCC p53基因突变率与该地区黄曲霉素(AFB1)含量及乙型肝炎病毒(HBV)感染分布一致.结论该结果提示 p53基因突变与 AFB1和 HBV 等环境因素的协同作用有关,其中 AFB1主要与 p53基因249位密码子特异型突变有关,而 HBV 可能在散发型突变中发挥重要作用.     

用树鼩cDNA芯片研究树鼩肝癌中参与信号传导的部分基因变化情况

目的利用树鼩cDNA芯片研究黄曲霉毒素B1（AFBl）和（或）乙型肝炎病毒（HBV）引起的树鼩肝细胞癌（HCC）发生过程中参与信号传导的部分基因表达变化情况，从而进一步探讨HCC发生的分子机制。方法实验树鼩分3组：A组（AFB1组）、B组（AFB1＋HBV组）、C组（正常对照组）。所有动物在实验过程中定期接受剖腹手术取肝组织检查，至肝癌形成时处死动物取肝癌和癌旁组织。用树鼩cDNA芯片检测实验第30、60、90周肝活检组织、肝癌组织及其癌旁组织中各基因的表达情况，并用实时逆转录聚合酶链反应（Real time RT-PCR）法验证cDNA芯片结果。结果在A组和B组从癌前到癌变过程中胰岛素样生长因子-Ⅱ（IGF-Ⅱ）、C-rel、核因子-κB2（NF—κB2）均显示有差异表达，同时bcl-2、细胞周期素A（cyclin A）、睫状神经营养因子（CNTF）仅在B组显示有差异表达。而C组这几个基因无差异表达。实验组与对照组比较，在诱癌的早、中期（30、60周）均出现CNTF及cyclin A的差异表达。realtime RT PCR结果与cDNA芯片检测结果基本一致。A组IGF-Ⅱ、C—rel基因及B组IGF-Ⅱ基因，在肝癌组织表达水平明显低于癌旁及实验30、60周组织，而癌旁与实验30、60周相比较则无明显差异；B组CNTF基因在癌旁、肝癌及60周之间比较无明显改变，但均明显高于30周；A组CNTF基因表达水平在癌旁、肝癌组织高于癌前组织，但差异无统计学意义；C组这3个基因不同时期比较亦无明显差异。结论树目自部分信号传导通路相关cDNA芯片应用于检测树目目HCC发生过程中信号传导通路中各基因表达的变化，对进一步了解树鼠甸HCC发生的机制有重要实用价值。IGF-Ⅱ、NF-κB2、C-rel、Bcl-2、cyclin A及CNTF这几个基因与树HCC的发生发展密切相关。     

基于RNA-Seq技术的跨种属跨病因肝癌差异表达基因的筛选

目的:运用全转录组测序(RNA sequencing,RNA-Seq)技术和跨种属、跨病因筛选策略,定位出影响肝癌发生发展的关键因子.方法:运用RNA-Seq技术,对人肝癌、癌旁和正常肝组织,以及乙型肝炎病毒(hepatitis B virus,HBV)和黄曲霉毒素B1(aflatoxins,AFB1)诱发的树鼩肝癌、癌旁和正常肝组织标本进行全转录组测序、基因表达水平分析和比较;分别筛选出人肝癌差异表达分子、HBV和AFB1致癌的树鼩肝癌差异表达因子,最后定位出跨人和树鼩两个物种、跨HBV和AFB1两种致癌因素的肝癌共同差异表达分子.结果:各标本总RNA提取质量合格,RNASeq测序数据质量合格,测序数据与参考基因对比匹配率合格,样品间基因表达相关性合格.人肝癌差异表达基因有68个,其中上调基因14个,下调基因54个;HBV诱发的树鼩肝癌差异表达基因有314个,AFB1诱发的树鼩肝癌差异表达基因有20个,HBV和AFB1诱发的树鼩肝癌共同差异表达基因11个,均为下调基因.人肝癌和树鼩肝癌共同差异表达基因为2个,分别是载脂蛋白F(apolipoprotein F,APOF)和人胰岛素样生长因子酸不稳定亚基(insulin-like growth factor binding protein,acid labile subunit,IGFALS),其mRNA表达水平在肝癌中均下调.结论:运用RNA-Seq技术,跨种属、跨病因筛选肝癌关键基因的研究策略有可能推动肝癌关键基因的定位;APOF和IGFALS有可能是影响肝癌发生发展的重要分子.     

ras、p53基因表达与丙型肝炎病毒感染相关性的免疫组化研究

目的 探讨丙型肝炎病毒(HCV)感染与肝细胞癌(HCC)之间的关系以及HCV可能的致癌机理。方法 采用免疫组织化学方法检测72例肝细胞癌标本癌及癌周组织中的HCVNS3抗原、ras基因的P21及抑癌基因P53蛋白。结果 肝细胞癌及癌周肝组织中有HCVNS3抗原检出，支持HCV与HCC之间有关联。在HCC的癌及癌周组织中P21呈致密的过量表达，提示ras癌基因的激活在HCC的发生过程中起一定作用。P53的阳性率较P21低，但p53的突变似乎也是肝癌发生的协同因素之一。组织中P21的过量表达与HCVNS3抗原阳性检出呈正相关。结论 HCV感染作为HCC的密切相关因素之一，可能通过激活某些癌基因或使某些抑癌基因突变而致肝细胞癌变。     

肝细胞癌p53基因249密码子热点突变的研究

目的 研究肝细胞癌(HCC)中p53基因249密码子(p53 E7 cd249)点突变情况。方法 用PCR法及HAEⅢ限制性片段长度多态性分析(HAEⅢ/RFLP)检测河南豫东地区38例HCC石蜡包埋组织及2例肝细胞癌株中p53 E7cd249点突变情况,DNA测序证实。选取广西桂西南地区的10例HCC作对照。结果 来自河南豫东地区的HCC p53 E7 cd249点突变率为10.5％(4/38),对照组广西桂西南地区的HCC p53 E7 cd249点突变为40％(4/10),二者相比具有显著性差异(P<0.05)。2例肝细胞癌株中均未发现HCC p53 E7 cd249点突变。结论 河南豫东地区HCC中p53基因E7 cd249点突变为非高发事件;p53 E7 cd249点突变可能发生在肝细胞癌变的晚期。     

肝细胞癌和肝硬变组织中突变型P53蛋白的表达及与HBV DNA的关系

应用LSAB免疫组化技术,检测肝内突变型P53蛋白的表达;用地高辛探针原位杂交检测HBV DNA。结果显示,31例肝细胞癌(HCC)及其癌旁组织中突变型P53蛋白阳性率分别为45％和48％,而11例肝硬变中检出4例(36.4％)。HBV DNA阳性率分别为46％和86％。癌旁组织中突变型P53蛋白表达与HBV DNA存在相关关系(P<0.05)。提示P53基因突变与HBV慢性感染有关,可能是诱发肝癌的机制之一。癌旁组织和肝硬变组织中也存在P53蛋白异常表达,表明肝癌形成早期就发生了53基因的突变。     

HBV基因型及A1762T/G1764A双位点变异在肝癌患者中的临床意义

目的:研究肝细胞癌(HCC)患者乙型肝炎病毒(HBV)基因型与基本核心启动子(BCP)基因区A1762T/G1764A双位点变异(BCP区双突变)之间的关系,探讨HCC的发病机制。方法:选择40例HCC患者作为研究组,40例慢性乙型肝炎(CHB)患者作为对照组,采用多对型特异性引物PCR扩增法进行基因分型及HBV基因多态性芯片检测BCP区A1762T/G1764A双位点变异。结果:40例HCC患者中有30例HBV DNA定量阳性,平均对数值为(6·53±1·31)copy/ml,将30例HBV DNA定量阳性的HCC及40例CHB患者的血清进行HBV基因分型及基因变异检测,结果显示30例HCC中HBV B基因型5例(16·7%),C基因型25例(83·3%);BCP区双突变共有20例(67·7%),其中B基因型1例,C基因型19例,BCP双突变率在B基因型和C基因型中分别为20%(1/5)和76%(19/25);40例CHB患者中B基因型32例(80%),C基因型8例(20%);BCP区双突变共有13例,其中B基因型8例,C基因型5例,BCP双突率在B基因型和C基因型中分别是25%(8/32)和62·5%(5/8)。结论:肝细胞癌的发生与BCP区A1762T/G1764A双位点变异有关,多发生在HBV C基因型的患者。     

乙型肝炎病毒X区基因变异与原发性肝癌的关系研究

目的初步研究乙型肝炎病毒(HBV)X区基因变异与原发性肝癌的关系。方法收集39例HBV感染患者的肝(癌)石蜡组织标本,其中慢性乙型肝炎(CHB)14例、肝细胞癌(HCC)25例。采用聚合酶链式反应(PCR)方法扩增组织中HBV X区基因,并对PCR产物进行DNA测序,分析常见变异位点的变异情况。结果 1.HCC组与CHB组相比,在X区发生插入/缺失变异,联合变异的位点及例数增多,并且A1762T与G1764A常发生双突变。2.HBV X区变异频率较高位点依次是C1655T/G、A1605C/G、A1762T、G1764A、A1772B、A1645C、C1687A、G1776T。结论 HBV X区存在点突变、插入/缺失变异及联合变异,可能在HCC的发生和发展过程中起重要作用。     

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.