转化生长因子-β1在人类糖尿病肾病的临床意义

转化生长因子-β1(TGF-β1)系统在体内广泛存在。细胞培养、动物实验及人体研究都证实TGF-β1在糖尿病肾病(DN)发生发展中起了重要作用。本文就TGF-β1在DN发病机制中的作用及在DN临床诊断和治疗中的意义作一综述。     

TGF-β在糖尿病肾病发病机制中的作用及意义

糖尿病肾病(DN)是直接威胁糖尿病(DM)患者生命及生活质量的慢性并发症之一,迄今其确切的发病机制尚未完全明了。近年来,越来越多的证据表明转化生长因子-β(transforminggrowthfactor-β,TGF-β)在DN的发病机制中占有重要地位,对TGF-β与DN关系的研究有可能为诊治DN提供新的思路。一、TGF-β及其受体的结构特点TGF-β家族是TGF-β超家族中的一员,它是由两条12.5kD、以二硫键结合的多肽链组成的二聚体[1～3]。在人类中,TGF-β有3种同功异构体:TGF-β1、β2、β3,它们的生物学特性基本是相同的,但每种异构体在靶细胞的作用位点不…     

Smad 2在糖尿病肾病中的作用及临床应用前景

糖尿病肾病(DN)是糖尿病(DM)的常见而严重的慢性并发症之一,是导致终末期肾病的首要病因.DN的发病机制尚不清楚,大量研究表明多种因素参与其发生发展,其中转化生长因子β1(TGF-β1)/Smad信号通路起重要作用.TGF-β1信号系统是细胞生长和分化的重要调节因素,Smads蛋白是TGF-β信号系统细胞内的重要转导因子,在TGF-β的刺激下Smads蛋白在核内积聚调节靶基因的转录,引起细胞外基质沉积,肾小球基底膜增厚,足细胞凋亡,导致DN,临床表现为蛋白尿和进行性肾功能衰竭.Smad 2是Smads蛋白家族中的一员,是TGF-β1在细胞内特有的作用底物,因此Smad 2与TGF-β受体短暂的结合和磷酸化是Smad复合体在细胞核内蓄积所必须,是信号转导的始动因子.本文就Smad 2蛋白分子的结构、生物学作用、细胞内信号转导、在DN发生发展中的作用及其在临床治疗方面的应用前景作一综述.     

TGF-β1与糖尿病肾病

糖尿病肾病 (DN)是直接危害糖尿病患者生命的慢性并发症之一。迄今为止其发病机制尚未完全明了。目前 ,越来越多的研究表明 :转化生长因子 -β1 (TGF-β1 )可能在 DN的发病机制中占有重要地位 ,因此 ,对 TGF- β1 与 DN关系的研究有可能为诊治 DN提供新思路。一、TGF- β1 及其受体的生物学特征TGF- β在哺乳动物体内主要存在着 TGF- β1 、β2 、β3三种同分异构体。TGF- β1 的基因为 10 0 kb。内源性蛋白酶如呋林蛋白酶(furin)调控产生的 12 .5 KDa的 TGF- β单体以二硫键形成有功能的同源二聚体。各异构体的生物学特性基本…     

TGF-β1诱导的上皮-间充质转化与糖尿病肾病

糖尿病肾病(DN)肾间质纤维化的初始环节之一是肾小管上皮-间充质转化(EMT),而转化生长因子-β1(TGF-β1)是EMT发生的重要诱导因子.了解DN中肾小管上皮细胞EMT的发生及过程,探讨Smad7、C-肽、TGF-β1抗体、组蛋白去乙酰化酶抑制剂和血管紧张素受体抑制剂在DN中的作用,将为DN治疗提供新的思路.     

糖尿病肾病患者外周血单个核细胞TGF-β_1基因表达的临床研究

为探讨外周血单个核细胞转化生长因子 (TGF- β1 )在糖尿病肾病 (DN)发生、发展中的作用 ,采用逆转录聚合酶链反应 (RT- PCR)技术半定量方法 ,对糖尿病 (DM)及 DN肾功能衰竭 (DRF)患者外周血单个核细胞(PBMC) TGF-β1 m RNA的表达水平进行测定 ,并与健康人 (对照组 )比较。结果显示 ,DRF组 TGF-β1 的表达最强 ,其次为 DN、DM组 ,对照组表达最弱 ,三者间两两比较 P均 <0 .0 1。认为 TGF- β1 参与了 DN病理变化的全过程 ,测定 PBMC中 TGF- β1 m RNA的表达 ,是判断 DN患者 DRF进展程度的较好方法     

银杏达莫注射液对实验性2型糖尿病大鼠肾脏TGF-β1表达的影响

目的 探讨银杏达莫注射液对2型糖尿病肾病(DN)大鼠肾脏转化生长因子(TGF)-β1表达的影响,从而探讨银杏达莫注射液对DN的治疗作用.方法 选取实验大鼠60只,以高热量饲料加小剂量链脲佐菌素(STZ)建立DN大鼠模型,将大鼠随机分为正常组、DN组和治疗组(每组各10只),观察各组大鼠一般情况及24 h蛋白尿、血糖、肾脏病理改变;采用免疫组化法检测TGF-β1的表达.结果 糖尿病组表现为大量蛋白尿、肾组织病理损害、TGF-β1高表达,与正常组有显著差异;治疗组24 h尿蛋白与正常组相比显著增高,与DN组相比有显著降低,肾组织病理损害明显减轻,TGF-β1表达高于正常组,低于ND组,差异显著.结论 银杏达莫注射液可以通过降低TGF-β1表达对2型糖尿病DN大鼠肾脏起到保护作用,延缓DN发展.     

雷米普利降低糖尿病肾病大鼠转化生长因子及其信号转导分子表达

目的 探讨雷米普利对糖尿病肾病(DN)大鼠肾保护的分子机制.方法 20周雄性自发性2型糖尿病大鼠随机分为糖尿病肾病(DN)对照组与治疗组;非DN大鼠分为非DN组与治疗组.治疗组大鼠给予雷米普利(3mg/kg体重)9周.检测各组大鼠的体重、血压、24小时尿蛋白(UPro/24h)、肌酐清除率(CCr);PAS染色和三色染色观察肾小球及肾小管问质病变;Northern杂交、免疫印迹法分别检测转化生长因子(TGF-β1)、Shred-2、Smad-4的表达.结果 与对照组相比,DN组血压、UPro/24h增加,CCr显著下降,TGF-β1、Smad-2、Smad-4的表达明显上调,伴有肾小球硬化和肾小管间质纤维化.雷米普利治疗后使上述指标均逆转.结论 雷米普利对DN大鼠具有肾治疗作用,其机制与干预TGF-β-Smnd信号转导通路有关.     

尿TGF-β1、层粘连蛋白、Ⅳ型胶原与2型糖尿病肾病的关系

在182例2型糖尿病患者测定尿液转化生长因子β1(TGF-β1)、层粘连蛋白(LN)和Ⅳ型型胶原排泄量，糖尿病患者的尿液TGF-β1、LN和Ⅳ型胶原排泄量增加，并与糖尿病肾病(DN)的严重程度有较好的相关性。尿TGF-β1可能为早期DN的指标、尿LN、Ⅳ型胶原可能为DN严重程度的指标。     

血清脂联素、转化生长因子β1在糖尿病肾病中的水平分析

目的探讨2型糖尿病肾病（DN）患者血清脂联素（APN）和转化生长因子β1（TGF-β1）的水平及二者的相关性。方法选择糖尿病患者120例,根据尿微量白蛋白排泄率（UAER）分为正常白蛋白尿组、微量白蛋白尿组、大量自蛋白尿组,用ELISA方法检测其血清APN和转化生长因子β1（TGF-β1）浓度,同时测定各组的UAER、血糖、血肌酐、糖化血红蛋白等的水平,取正常人34例为对照组。结果（1）血清APN、TGF-β1水平随病程进展逐渐升高,各组间比较差异均有显著性（P〈0．05）。（2）在DN阶段血清APN与TGF-β1水平呈显著正相关,相关系数r=0．449（P〈0．01）。（3）在DN阶段血清APN、TGF-β1水平与UAER、血糖、血肌酐、糖化血红蛋白水平呈正相关。结论APN和TGF-β1可能在DN的发病过程中起重要作用;TGF-β1可作为早期发现DN的一种新的敏感指标;APN、TGF-β1有望成为治疗DN的新靶点。     

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.