肾素-血管紧张素系统与肾脏疾病

肾素－血管紧张素系统（ＲＡＳ）由肾素、血管紧张素原、血管紧张素Ⅰ（ＡｎｇⅠ）、血管紧张素转换酶（ＡＣＥ）、血管紧张素Ⅱ（ＡｎｇⅡ）以及血管紧张素受体（ＡＴＲ）等六大成分组成，其中ＡｎｇⅡ为主要的生物活性肽。本系统在肾脏疾病中的作用几乎涉及到肾脏疾病过...     

血管紧张素II受体拮抗剂治疗充血性心力衰竭的研究进展

血管紧张素ＩＩ受体拮抗剂是近年来国际上研究的热点之一[1,2 ] ,目前此类药物已在我国上市 ,下面对其特点及其治疗充血性心力衰竭 (ＣｏｎｇｅｓｉｔｖｅＨｅａｒｔＦａｉｌ ｕｒｅ ,ＣＨＦ)予以总结。肾素 血管紧张素系统肾素 血管紧张素系统 (Ｒｅｎｉｎ Ａｎ ｇｉｏｔｅｎｓｉｎＳｙｓｔｅｍ ,ＲＡＳ)在血压调节过程中起着重要的作用 ,肝脏合成血管紧张素原 ,在肾素作用下 ,转化为血管紧张素Ⅰ(ＡｎｇⅠ ) ,再在肺脏产生的转换酶作用下 ,变成血管紧张素Ⅱ (ＡｎｇⅡ )。除循环中的ＡｎｇⅡ起作用外 ,通过自分泌 /旁分泌的局部ＡｎｇⅡ…     

血管紧张素Ⅱ受体亚型Ⅰ拮抗剂应用的进展

血管紧张素Ⅱ受体亚型Ⅰ拮抗剂应用的进展麦炜颐马虹综述（中山医科大学附属第一医院心内科广州５１００８０）关键词受体，血管紧张素拮抗剂，血管紧张素受体肾素－血管紧张素系统（ＲＡＳ）是机体调节血压，维持体液平衡的重要系统。其中，血管紧张素Ⅱ（ＡｎｇⅡ），对...     

血管紧张素Ⅱ及其受体和拮抗剂

血管紧张素Ⅱ及其受体和拮抗剂第一军医大学南方医院心内科袁勇综述刘伊丽审校肾素－血管紧张素系统（ＲＡＳ）在血压调节和电解质体液平衡中的重要作用，已被人们认识几十年了，血管紧张素Ⅱ（ＡｎｇⅡ）是ＲＡＳ中的主要介质，人们一直在寻找阻断ＡｎｇⅡ产生的药物，临...     

AT1受体的研究进展

肾素 血管紧张素系统 (ＲＡＳ)通过影响血管紧张性 ,体液和电解质平衡及交感神经的活性 ,在血压及心血管稳态调节中占有极其重要的地位。其生物效应主要是通过高活性的八肽ＡｎｇⅡ来实现的。经典观点认为ＲＡＳ是一循环内分泌系统 ,肝脏产生的血管紧张素原被肾素分解 ,产生无活性的十肽ＡｎｇⅠ ,再在肺循环中被血管紧张素转化酶 (ＡＣＥ)酶解为有活性的八肽ＡｎｇⅡ。除了循环系统中的ＲＡＳ ,现已发现许多组织如血管、心脏、肾脏和脑都能合成ＡｎｇⅡ ,通过旁分泌 ,自分泌和细胞内分泌等形式作用于组织。在这些组织中存在完整的ＲＡＳ。…     

血管紧张素(1-7)的生成及其生理意义

简述血管紧张素（１－７）的研究进展。Ａｎｇ（１－７）是由血管紧张素原经过酶促级联反应生成的产物，近年发现它具有调节血压及舒张血管等生物活性。Ａｎｇ（１－７）可能是ＡｎｇⅡ的内源性抑制因子，反馈调节ＡｎｇⅡ的生物效应     

脑内血管紧张素II受体亚型与高血压研究进展

肾素－血管紧张素系统（ＲＡＳ）不仅作用于外周血管，而且作用于中枢神经系统，使血压升高，脑内ＲＡＳ的发现对于了解局部生成肽激素及其与全身激素系统的相互作用，提供了新的概念。研究结果表明，血管紧张素Ⅱ（ＡｎｇⅡ）不仅具有一种循环激素的功能，而且也作为中枢神经系统的一种多肽在血压调压等方面发挥着重要的作用。目前认为，ＡｎｇⅡ在脑内的信息传递。本文就脑内ＡｎｇⅡ受体的研究新进展作一综述，着重讨论ＡｎｇⅡ受     

血管紧张素Ⅱ的综合效应

血管紧张素Ⅱ的综合效应［ＣｏｄｙＲＪ．ＡｍＪＣａｒｄｉｏｌ，１９９７，７９（５Ａ）：９（英文）］血管紧张素Ⅱ的作用：（１）血管作用——ＡｎｇⅡ是重要而强烈的内源性血管收缩因子之一，它可通过许多器官系统影响血压。血浆ＡｎｇⅡ升高时，可阻碍血流的流畅、减...     

血管紧张素（1—7）的生成及其生理意义

简述血管紧张素（１－７）的研究进展，Ａｎｇ（１－７）是由血管紧张素原经过酶促级联反应生成的产物，近年发现它具有调节血压及舒张血管等生物活性，Ａｎｇ（１－７）可能是ＡｎｇⅡ的内源性抑制因子，反馈调节ＡｎｇⅡ的生物效应。     

血管紧张素Ⅱ对血管平滑肌细胞增殖的调节作用

肾素－血管紧张素系统在调节血压、维持水电解质平衡等方面起重要作用，近来研究表明血管紧张素Ⅱ（ＡｎｇⅡ）对心肌细胞、成纤维细胞及血管平滑肌细胞（ＶＳＭＣ）具有生长激素样作用，可能参与了阻塞性血管疾病如冠心病、血管成形术后再狭窄的发生。随着ＡｎｇⅡ受体分...     

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.     

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.     

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.     

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.