血管紧张素转换酶2与高血压

血管紧张素转换酶2与血管紧张素转换酶一样参与肾素-血管紧张素系统中血管紧张素的代谢。它通过将血管紧张素Ⅱ水解成血管紧张素1-7对抗血管紧张素转换酶-血管紧张素Ⅱ代谢轴,是平衡肾素-血管紧张素系统内部调节的另一血管紧张素代谢通路。这种系统的内部调节在调节心血管系统活动中起重要作用,其平衡的破坏与高血压等相关疾病的发生发展密切相关,通过调节血管紧张素2来治疗高血压及其并发症可能是本世纪高血压治疗学上的新靶点。     

肾素-血管紧张素系统:新成员,新效应

肾素-血管紧张素系统（RAS）通过作用于心血管、肾脏、肾上腺，控制体液、电解质平衡以及动脉压，是机体重要的调控系统。经典的RAS主要成分有肾素、血管紧张素原（AGT）、血管紧张素Ⅰ（AngⅠ）、血管紧张素Ⅱ（AngⅡ）、血管紧张素转换酶（ACE）、血管紧张素受体1（AT1）、血管紧张素受体2（AT2R）。     

血管紧张素转换酶2研究进展

血管紧张素转换酶2是一种金属钛酶,它将血管紧张素I、血管紧张素Ⅱ分别水解为血管紧张素（1～9）及具有血管舒张、抗增殖的血管紧张素（1～7）。血管紧张素转换酶2参与了肾素-血管紧张素-醛固酮系统中多种肽的代谢过程,与高血压、肾脏疾病、糖尿病等发生相关,对心脏、肾脏有一定保护作用,进一步研究其参与保护的机制,有可能为心血管病治疗提供新的靶点。     

心血管紧张素-（1-7）在心血管系统中的作用

血管紧张素-（1-7）是肾素-血管紧张素系统中具有重要生物学作用的终末活性产物,可通过直接作用于心血管中枢调节心血管活动以及与心脏和血管上特异性受体结合而发挥改善心功能、降低血压、抑制心脏和血管重构作用。现就血管紧张素-（1—7）对心血管系统中的作用综述如下。     

血管紧张素受体拮抗剂治疗高血压

肾素-血管紧张素-醛固酮系统（RAAS）是调节血压的主要机制,也是治疗高血压病的重要靶点。血管紧张素受体拮抗剂（ARBs）,通过阻滞特异性血管紧张素受体,干扰RAAS的活性,成为治疗高血压的一线药物。临床结果显示ARBs作为单用药或联合其他降压药物治疗高血压有其特殊的优势。在降压方面,与血管紧张素转换酶抑制剂和其他类型的降压药物相比,ARBs具有良好的耐受性而适合用于治疗更广泛的患者。最近研究结果显示在12个月期间使用ARBs治疗高血压依从性明显高于其他降压药物,而且副作用少。具备临床有效性和良好耐受性的ARBs药物,可以作为治疗高血压的主要药物。     

血管紧张素转换酶2基因多态性与肾脏损害

肾素血管紧张素系统（RAS）是体内调节神经体液和心血管功能的主要系统。新发现的多肽酶血管紧张素转换酶2（ACE2）通过产生血管紧张素（Ang）1-7和水解部分AngⅡ,拮抗由ACE水解产物AngⅡ介导的缩血管作用，并抑制血管平滑肌细胞增殖。研究表明糖尿病大鼠肾脏ACE2表达下降，糖尿病、高血压和代谢综合征均可损害肾脏，本研究旨在探讨这三种疾病患者ACE2基因A/C多态分布情况及其与肾脏损害的关系。     

血管紧张素转换酶2的研究进展

血管紧张素转换酶2是肾素-血管紧张素系统的一个新成员,是迄今为止发现的第一个人类血管紧张素转换酶同族物。它能水解血管紧张素Ⅰ,生成血管紧张素(1-9),水解血管紧张素Ⅱ,生成血管紧张素(1-7),不仅能调节心血管功能和肾功能,而且在一系列炎症和免疫机制发挥作用的疾病发展过程中起一定作用。现就血管紧张素转换酶2的研究现状进行综述。     

血管紧张素转换酶2在心血管系统中的意义

血管紧张素转换酶2（ACE2）是2000年才发现的肾素-血管紧张素系统的新成员,主要表达于心脏、肾脏和睾丸。ACE2的主要生物学效应是降解血管紧张素II（AngII）产生Ang1-7,Ang1-7具有舒张血管、抗增生、抗炎症的作用,对衰竭心脏有保护作用。研究发现ACE2基因敲除小鼠心功能受损,AngII水平升高。本文综述了ACE2的生物学效应以及在心血管系统中的意义。     

血管紧张素-(1-7)在心血管系统中的作用

血管紧张素-(1-7)是肾素-血管紧张素系统中具有重要生物学作用的终末活性产物,可通过直接作用于心血管中枢调节心血管活动以及与心脏和血管上特异性受体结合而发挥改善心功能、降低血压、抑制心脏和血管重构作用.现就血管紧张素-(1-7)对心血管系统中的作用综述如下.     

应激性高血压大鼠血浆与组织血管紧张素Ⅱ含量的变化

为了探讨血管紧张素Ⅱ在应激性高血压发病中的作用，采用电击大鼠足底加同步噪音作应激源，建立急性和慢性应激性高血压模型。用放射免疫测定法检测应激性高血压大鼠血浆和组织中血管紧张素Ⅱ的含量。结果发现，血管紧张素Ⅱ在急性应激性高血压大鼠的血浆和肾上腺中的含量急骤升高（P＜0．001和P＜0．01），在主动脉和下丘脑内电有所增加（P＜0．05）；在慢性应激性高血压大鼠的心血管和中枢神经组织内血管紧张素Ⅱ的含量也明显增加。结果提示血浆和肾上腺中血管紧张素Ⅱ可能与急性应激性高血压有关；心血管和中枢神经等组织内血管紧张素Ⅱ可能与慢性应激性高血压有关。     

Advances in Retinal Tissue Engineering

Retinal degenerations cause permanent visual loss and affect millions world-wide. Current treatment strategies, such as gene therapy and anti-angiogenic drugs, merely delay disease progression. Research is underway which aims to regenerate the diseased retina by transplanting a variety of cell types, including embryonic stem cells, fetal cells, progenitor cells and induced pluripotent stem cells. Initial retinal transplantation studies injected stem and progenitor cells into the vitreous or subretinal space with the hope that these donor cells would migrate to the site of retinal degeneration, integrate within the host retina and restore functional vision. Despite promising outcomes, these studies showed that the bolus injection technique gave rise to poorly localized tissue grafts. Subsequently, retinal tissue engineers have drawn upon the success of bone, cartilage and vasculature tissue engineering by employing a polymeric tissue engineering approach. This review will describe the evolution of retinal tissue engineering to date, with particular emphasis on the types of polymers that have routinely been used in recent investigations. Further, this review will show that the field of retinal tissue engineering will require new types of materials and fabrication techniques that optimize the survival, differentiation and delivery of retinal transplant cells.     

同型半胱氨酸对血管内皮细胞合成蛋白聚糖的影响

为探讨同型半胱氨酸对血管内皮细胞合成蛋白聚糖的影响，采用400umol／L同型半胱氨酸作用于培养的人脐静脉内皮细胞，以^35S-Na2SO4为示踪物标记细胞合成的蛋白聚糖，通过离子交换层析，凝胶过滤层析分离蛋白聚糖。结果发现，实验组培养液中总蛋白聚糖降低，硫酸乙酰肝素蛋白聚糖及硫酸软骨素-硫酸皮肤素蛋白聚糖含量也降低，但其百分含量未见改变。细胞层中蛋白聚糖未见明显变化。     

International Hemoglobin Information Center Policies - Ihic

Abstract

The levels of the inactive hemoglobin (Hb) pigments [such as methemoglobin (metHb), carboxyhemoglobin (HbCO) and sulfohemoglobin (SHb)] and the active Hb [in the oxyhemoglobin (oxyHb) form] as well as the blood Hb concentration in healthy non pregnant female volunteers were determined using a newly developed multi-component spectrophotometric method. The results of this method revealed values of SHb% in the range (0.0727–0.370%), metHb% (0.43–1.0%), HbCO% (0.4–1.52%) and oxyHb% (97.06–98.62%). Furthermore, the results of this method revealed values of blood Hb concentration in the range (12.608–15.777?g/dL). The method is highly sensitive, accurate and reproducible.     

Efficacy of combination treatment with cyclosporin A and corticosteroids for acute interstitial pneumonitis associated with dermatomyositis

Interstitial pneumonitis (IP) associated with polymyositis and dermatomyositis (PM/DM) is a serious complication that affects prognosis. We therefore undertook a retrospective multicenter study to examine the efficacy of a combination treatment with cyclosporin A (CsA) and corticosteroids. Fifty-three IP patients with PM/DM (9 PM, 44 DM) were analyzed. Thirty-two patients treated with CsA plus corticosteroids (9 PM, 23 DM) were included in the study. Four parameters, i.e., subjective symptoms, ausculatory sound, chest radiographs, and respiratory index, were serially evaluated. A general evaluation was performed 4 weeks after the start of the combination treatment. All patients with PM and chronic IP with DM, and 52% of those with acute IP with DM were graded as better than partially effective in the general evaluation. In contrast, all patients graded as progressive in the general evaluation had acute IP with DM. It is of note that in acute IP with DM, the survival rate of the group primarily treated with CsA and corticosteroids from the early stage of their disease was significantly higher than that of the group initially treated with corticosteroids alone (P = 0.049). In conclusion, a combination treatment of CsA and corticosteroids from the early stage of disease may be advantageous for patients with IP with PM/DM, especially acute IP with DM.     

Efficacy of combination treatment with cyclosporin A and corticosteroids for acute interstitial pneumonitis associated with dermatomyositis

Abstract

Interstitial pneumonitis (IP) associated with polymyositis and dermatomyositis (PM/DM) is a serious complication that affects prognosis. We therefore undertook a retrospective multicenter study to examine the efficacy of a combination treatment with cyclosporin A (CsA) and corticosteroids. Fifty-three IP patients with PM/DM (9 PM, 44 DM) were analyzed. Thirty-two patients treated with CsA plus corticosteroids (9 PM, 23 DM) were included in the study. Four parameters, i.e., subjective symptoms, ausculatory sound, chest radiographs, and respiratory index, were serially evaluated. A general evaluation was performed 4 weeks after the start of the combination treatment. All patients with PM and chronic IP with DM, and 52% of those with acute IP with DM were graded as better than “partially effective” in the general evaluation. In contrast, all patients graded as “progressive” in the general evaluation had acute IP with DM. It is of note that in acute IP with DM, the survival rate of the group primarily treated with CsA and corticosteroids from the early stage of their disease was significantly higher than that of the group initially treated with corticosteroids alone (P = 0.049). In conclusion, a combination treatment of CsA and corticosteroids from the early stage of disease may be advantageous for patients with IP with PM/DM, especially acute IP with DM.     

Methemoglobin Forming Effect of Dimethyl Trisulfide in Mice

Abstract

Dimethyl trisulfide (DMTS) is a natural organic trisulfide that has been patented as a promising antidotal candidate against cyanide (CN). The primary mode of action of DMTS is as a sulfur donor that enables the conversion of CN to thiocyanate. Recently, it was discovered that DMTS is capable of oxidizing hemoglobin (Hb) to methemoglobin (MetHb) in vitro. The goal of these experiments was to measure the extent of DMTS-induced MetHb formation in vivo. In these experiments, intramuscular (IM) injections of formulated DMTS were administered to mice. Following the IM injection, blood was drawn and analyzed for MetHb using a rapid spectrophotometric method. Methemoglobin levels peaked in a dose-dependent manner between 20 and 30?min., and then began dropping. The highest MetHb levels measured for the 50, 100, 200 and 250?mg/kg doses of DMTS were respectively 3.28, 6.12, 9.69, and 10.76% MetHb. These experiments provide the first experimental evidence that IM administered DMTS generates MetHb in vivo and provide additional evidence for the presence of a secondary therapeutic pathway for DMTS - CN scavenging by DMTS-generated MetHb.     

Golimumab for moderate to severe ulcerative colitis

Introduction: Golimumab (GLM) is a subcutaneously administered human anti-tumor necrosis factor (TNF) agent that has been approved by the regulatory authorities for the treatment of moderate to severe ulcerative colitis (UC) in 2013.

Areas covered: Maintained clinical remission rates up to 50% have been shown in UC patients receiving GLM, and higher GLM serum concentrations have been associated with improved clinical outcomes. Approximately 50% of UC patients do not respond to induction therapy with GLM, and up to 40% of GLM responders will lose response over time. In most patients, loss of response is associated with low serum GLM concentrations, which suggests insufficient exposure to GLM. Low GLM serum concentrations may be avoided by therapeutic drug monitoring.

Expert commentary: So far, the therapeutic window for GLM has not yet been defined, but options to dose increase GLM based on therapeutic drug monitoring might result in improved clinical outcome and higher success rates.     

The Mitochondrial Permeability Transition: Role in Ischemia/Reperfusion Injury

The mitochondrial permeability transition (MPT) occurs when a non-specific pore opens in the inner mitochondrial membrane and converts the mitochondrion from an organelle whose ATP production sustains the normal function of the cell to an instrument of death. Conditions favouring the MPT including high [Ca2+], oxidative stress and adenine nucleotide depletion, all of which occur when a tissue is reperfused following a period of ischemia. Cyclosporin A (CsA) and low pH (<7.0) are potent inhibitors of the MPT. Methods have been devised to demonstrate directly that the MPT pores open upon reperfusion but not during ischemia. The mechanism of the MPT appears to involve binding of mitochondrial cyclophilin (CyP) to the adenine nucleotide translocase (ANT) followed by a calcium-mediated conformational change that converts the ANT into a non-specific pore. Understanding the molecular mechanism has assisted in devising strategies that can be used to protect tissues from damage caused by reperfusion injury. These might also be of benefit in the prevention of multiple organ failure for which reperfusion injury of the gut is thought to be the initial trigger. Protective regimes include the pretreatment of tissues prior to ischemia/reperfusion with CsA (binds to CyP), free radical scavengers that reduce oxidative stress (e.g., pyruvate and propofol) and agents that decrease pHi (e.g., pyruvate or amelioride derivatives). Reperfusion injury can produce both immediate cell death by necrosis or delayed apoptotic cell death and it appears that the mitochondria determine which route is taken. Prolonged opening leads to rapid cell death by necrosis, whilst transient opening leads to cytochrome c release and subsequent apoptosis hours or days later.     

Papillomavirus Infectious Pathways: A Comparison of Systems

The HPV viral lifecycle is tightly linked to the host cell differentiation, causing difficulty in growing virions in culture. A system that bypasses the need for differentiating epithelium has allowed for generation of recombinant particles, such as virus-like particles (VLPs), pseudovirions (PsV), and quasivirions (QV). Much of the research looking at the HPV life cycle, infectivity, and structure has been generated utilizing recombinant particles. While recombinant particles have proven to be invaluable, allowing for a rapid progression of the HPV field, there are some significant differences between recombinant particles and native virions and very few comparative studies using native virions to confirm results are done. This review serves to address the conflicting data in the HPV field regarding native virions and recombinant particles.     

Efficacy and safety of bucillamine, a d-penicillamine analogue, in patients with active rheumatoid arthritis

Japanese rheumatologists consider bucillamine (Buc) to be a useful disease-modifying antirheumatic drug (DMARD) and often give Buc to patients with rheumatoid arthritis (RA) prior to administering methotrexate (MTX). However, no large studies on the efficacy and safety of Buc in RA patients have been published in English to date. We therefore investigated the clinical course of RA patients treated with Buc and compared the results with those for patients treated with MTX to evaluate and confirm the place of Buc in therapeutic strategies for RA in Japan. Our results suggested that Buc should be given to patients with moderately active RA either before or after the administration of MTX because its efficacy can be judged within 3 months and because serious adverse events are rare. Issues like the ability of Buc to prevent joint destruction and its efficacy and safety when combined with agents like etanercept require future study.