肝纤维化研究进展

肝纤维化是各种病因所引起的慢性肝脏疾病的共同病理过程,是肝脏中细胞外基质（ECM）增生与降解失衡,进而导致肝脏内纤维结缔组织异常沉积的结果。近年来肝纤维化也是国内外学者研究的热点,但其发生、发展机制尚未完全阐明。各种因素所导致的肝星状细胞激活、趋化和增殖,引起一系列促纤维化细胞因子的分泌,从而导致胶原合成增加被认为是肝纤维化过程中重要的病理过程。因此肝星状细胞的活化被认为是肝纤维化过程中的始动因素。此文对近年来肝纤维化发生、发展的分子生物学研究进展作一综述。     

氧化应激与肝纤维化

肝纤维化的主要病理改变是细胞外基质(ECM)成分的过度合成与异常沉积,肝星状细胞(HSC)活化、增殖是肝纤维化形成的中心环节[1].诸多肝损伤因素在其致病过程中均不同程度地伴有氧化应激(oxidative stress,OS),这些病因不祛除、长期作用于肝脏即可导致肝纤维化乃至肝硬化.近年来,氧化应激与肝纤维化,特别是HSC活化的关系日益受到关注[2,3].本文就氧化应激在不同病因所致肝纤维化中的作用及其机制作一综述.……     

肝星状细胞、机体血浆纤溶系统与活血化瘀法

肝纤维化(hepatic fibrosis)是肝细胞发生坏死及炎症刺激时,肝脏内纤维结缔组织异常增生的病理过程,肝纤维化既是一种代偿修复反应,又是肝损害的促进因素,这种动态演变过程是肝病慢性化重要的病理特征,也是进一步向肝硬化发展的主要中间环节。当前的研究表明,肝星状细胞是肝纤维化的中心细胞环节,是导致胶原代谢异常的重要因素,中医活血化瘀法及其方药确有较好的抗肝纤维化作用。     

免疫细胞在肝纤维化发生发展中的作用

肝纤维化是各种病因导致的慢性肝病的共同病理改变,其发生机制与肝星状细胞(HSC)的活化和增殖有关。免疫细胞与HSC的相互作用可调控肝纤维化基质的形成及过度沉积,导致肝纤维化和肝硬化的发生。综述了近年来肝纤维化形成过程中的免疫细胞的作用及机制,总结了先天性免疫系统及适应性免疫系统对肝纤维化的调控。因此,深入研究肝纤维化发病过程免疫细胞、细胞因子与HSC的相互作用,以及免疫机制的调控作用,有助于为肝纤维化的治疗提供新的契机。     

Wnt/β-catenin通路与肝星状细胞的活化、增殖

肝纤维化是指各种致病因子导致肝细胞炎症、坏死,肝脏中胶原蛋白等细胞外基质(extracellular matrix)降解与沉积失衡,进而导致肝脏内结缔组织异常增生的病理状态.在肝纤维化的形成过程中,肝星状细胞为主要效应细胞.肝星状细胞的激活、分泌细胞外基质、过度的细胞外基质的沉积是形成肝纤维化的中心环节.Wnt/β-catenin通路参与器官纤维化的机制并没有被明确,但已有文献报道Wnt信号通路参与到器官纤维化和肝纤维化的过程中.国内外也均有研究证实Wnt/β-catenin通路与肝星状细胞的活化增殖、肝纤维化存在着一定的关系.     

肝纤维化发病机制研究新进展

<正>肝纤维化是肝脏持续发生组织损伤、修复反应时因细胞外基质(extracellular matrix,ECM)合成降解与沉积不平衡而引起的病理过程,是慢性肝病的病理特征,也是进一步向肝硬化发展的主要环节。肝星状细胞的活化、MMPs/TIMPs平衡失调、转化生长因子(TGF-β)均被证明在导致肝纤维化的发生过程中起重要作用,并且三种因素之间可以相互调节,形成复杂网络系统。现就肝纤维化的发病机制的研究新进展对寻找缓     

靶向肝星状细胞的基因治疗逆转肝纤维化的研究进展

<正>肝纤维化由肝脏受到慢性损伤后细胞外基质的过度沉积引起,激活的肝星状细胞(HSCs)是细胞外基质的主要来源。肝纤维化是许多慢性肝脏疾病的共同病理基础与特征,包括病毒性和自身免疫性肝炎,铁沉积,酒精性肝病和胆汁淤积等。目前认为肝脏细胞外基质的合成与降解失衡,导致其在肝内过度沉积是肝纤维化发展的主要机制。肝损伤导致HSCs活化     

纳米药物治疗肝纤维化的研究进展

肝纤维化是由肝脏慢性损伤和炎症反应引起肝星状细胞(HSC)活化和细胞外基质过度沉积的病理过程。HSC活化是肝纤维化形成的核心机制，抑制HSC激活是促进肝纤维化逆转的关键。近年来，应用靶向HSC的纳米药物来治疗肝纤维化取得了快速发展。本文主要介绍纳米药物、纳米药物在肝纤维化中的作用机制及可能存在的潜在靶点。纳米药物有望成为治疗肝纤维化的新方法。     

中医药治疗肝纤维化研究进展

正肝纤维化是一种病理学概念,以肝组织的细胞外基质异常增生与分布为特征,导致肝脏的结构和功能改变。肝纤维化是多种慢性肝病的共同病理特点和病理发生机制,病毒性肝炎、酒精、药物、脂肪肝、自身免疫性肝病、胆汁淤积和遗传代谢性疾病等原因引起的慢性肝病均存在肝纤维化的病理特点。肝纤维化是一个动态发展过程。随着纤维化程度的加重,慢性肝炎可进一步演变为肝硬化,甚至肝癌。因此,积极防治肝纤维化对于慢性肝病具有     

肝纤维化和肝硬化防治研究进展

肝纤维化(Hepatic fibrosis)是指肝细胞发生坏死及炎症刺激时，肝内纤维结缔组织增生的病理过程。轻者称为肝纤维化，当有假小叶及结节形成，称为肝硬化。慢性肝病的重要病理基础是肝纤维化，通过纤维化的发展走向肝硬化。肝纤维化是各种原因引起的慢性肝损害导致的病理状态过程，是发展为肝硬化形成的基础和必要阶段。现已证实肝纤维化的第一步是炎症反应和肝星状细胞(hepatic stellate cell，HSC)的激活。     

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.