NADPH氧化酶在缺血性卒中后氧化应激中的作用

氧化应激在脑缺血再灌注损伤中起着十分重要的作用.NADPH氧化酶(NADPH oxi-dase,NOX)在缺血性卒中氧化应激中的作用日益受到关注,有可能会成为一个新的治疗靶点.文章归纳了NOX与脑缺血再灌注损伤的主要研究进展,讨论了各种同工酶的特点及其与卒中的关系,从NOX角度进一步探讨卒中的发病机制,为缺血性卒中的防治提供了新的思路.     

NADPH氧化酶亚基在心脏重构中作用的比较

早期研究证实,烟酰胺腺嘌呤二核苷酸(还原型辅酶Ⅱ,NADPH)氧化酶在血管紧张素Ⅱ(AngⅡ)介导的心室重构中发挥重要作用,随着对NADPH氧化酶的深入研究,发现其共有5种亚基和两种相关的亚基,其中在心脏组织中表达的主要为Nox2与Nox4。Nox2在AngⅡ、心肌梗死及阿霉素介导的心室重构中具有重要的促进作用,而在压力负荷过大时引起的左心室肥大中Nox4 mRNA表达上调明显,由此可得出NADPH氧化酶亚基Nox2与Nox4在心室重构中的作用不同。因此,深入研究NADPH氧化酶亚基及其在心室重构中的作用,将成为改善心室重构新的治疗靶点。     

尼克酰胺腺嘌呤二核苷酸磷酸氧化酶与心血管疾病关系的研究进展

活性氧的增加与心血管疾病密切相关,而产生活性氧的主要酶体是尼克酰胺腺嘌呤二核苷酸氧化酶(NADPH氧化酶)。NADPH氧化酶对动脉粥样硬化、高血压、心力衰竭的发生发展起着重要的作用;而心房颤动又可引起NADPH氧化酶的增加。     

心肌AngⅡ和NADPH氧化酶源性的ROS在心肌肥厚中的作用

目的探讨心肌组织NADPH氧化酶源性的活性氧（ROS）在血管紧张素II（AngⅡ）调控心肌肥厚发生发展中的作用。方法采用腹主动脉缩窄术（AC）构建大鼠压力超负荷心肌肥厚模型,给予血管紧张素转换酶抑制剂（ACEI）卡托普利和NADPH氧化酶抑制剂Apocynin（Apo）干预8周,测定左心室重/体重比（LV/Bwt）;放免法检测心肌AngⅡ含量;激光共聚焦显微镜检测心肌组织O2.-水平;免疫组化检测心肌NADPH氧化酶的表达。结果⑴AC术后大鼠心肌组织AngⅡ含量、NADPH氧化酶表达及O2.-水平均升高;（2）卡托普利干预可显著降低心肌中AngⅡ含量、NADPH氧化酶表达及O2.-水平,并使心室肥厚程度显著降低;（3）Apo干预对肥厚心肌中AngⅡ含量、NAD-PH氧化酶表达无明显影响,但可部分降低心肌O2.-水平并抑制心室肥厚。结论持续压力超负荷致心肌AngⅡ含量升高可调控NADPH氧化酶表达上调,进而引起O2.-水平升高,这可能是压力超负荷致心室肥厚的重要调控路径。     

硫辛酸对db/db小鼠胰岛内NADPH氧化酶表达的影响

目的 探讨硫辛酸对db/db小鼠胰岛内NADPH氧化酶表达水平的影响.方法 将20只8周龄db/db小鼠随机分为硫辛酸组和db/db对照组,每组10只,分别给予硫辛酸60 mg/(kg·d)和安慰剂灌胃.另设10只同周龄db/m小鼠,给予安慰剂灌胃作为非糖尿病对照组(db/m对照组).每周监测体重、血糖,6周后取胰腺行免疫组化,分析NADPH氧化酶表达情况.结果 与db/db组相比,硫辛酸组小鼠的血糖降低,胰岛内NADPH氧化酶gp91phox、p22phox亚基的表达水平亦显著降低,差异有统计学意义(P<0.05).结论 硫辛酸降低胰岛内NADPH氧化酶的表达,减少氧化应激,从而保护胰岛β细胞.     

阻塞性睡眠呼吸暂停低通气综合征患者诱导痰中烟酰胺腺嘌呤二核苷酸磷酸氧化酶p22phox水平与病情的关系

目的 观察OSAHS患者诱导痰中烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶p22phox的水平,探讨OSAHS患者气道局部氧化应激与病情严重程度的关系.方法 对2007年9月至2008年6月华中科技大学附属同济医院呼吸科就诊并进行睡眠监测的30例OSAHS患者和23名健康体检者分别行痰诱导,睡前和晨起各1次.其中OSAHS组男27例,女3例,平均年龄(43±9)岁;健康对照组男21名,女2名,平均年龄(45±10)岁.痰细胞涂片并行细胞分类计数,以逆转录PCR法检测诱导痰细胞中NADPH氧化酶p22phox mRNA水平,以免疫细胞化学法检测诱导痰细胞中NADPH氧化酶p22phox蛋白的表达水平.结果 OSAHS组诱导痰细胞中巨噬细胞百分比为(34±10)%,低于对照组的(66±5)%;而中性粒细胞百分比为(65±10)%,高于对照组的(33±5)%,两组比较,差异均有统计学意义(t=15.051、14.359,P<0.05).诱导痰细胞中NADPH氧化酶p22phox阳性细胞主要为中性粒细胞和巨噬细胞.OSAHS组2次诱导痰细胞中NADPH氧化酶p22phox mRNA水平及中性粒细胞和巨噬细胞阳性率均明显高于对照组.OSAHS组晨起时NADPH氧化酶p22phoxmRNA的表达水平及中性粒细胞和巨噬细胞阳性率高于睡前,并与最低脉搏氧饱和度呈负相关,与呼吸暂停低通气指数呈正相关.结论 OSAHS患者存在气道局部NADPH氧化酶p22phox表达水平的变化,并与病情严重程度相关.     

NADPH氧化酶、氧化应激和糖尿病

NADPH氧化酶是一种过氧化物酶,广泛存在于吞噬细胞外的其他组织细胞。NADPH氧化酶过度激活所介导的氧化应激损伤参与了糖尿病及其并发症的发生发展。     

NADPH氧化酶与动脉粥样硬化和缺血性脑血管病

活性氧(reactive oxygen species,ROS)导致的氧化应激在动脉粥样硬化发生和发展过程中起着重要作用,并与缺血性脑血管病发生相关.文章对NADPH氧化酶在动脉粥样硬化和缺血性脑血管病中的作用机制以及NADPH氧化酶抑制剂的神经保护作用进行了综述.     

NADPH氧化酶与动脉粥样硬化

近年研究表明,烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶是血管活性氧的主要来源。当活性氧的生成与清除平衡失调时,过多的活性氧可通过多种途径造成血管壁的损伤,成为致动脉粥样硬化（AS）的危险因素。在人和实验动物的AS病变部位,也发现NADPH氧化酶的活性与表达异常,NADPH氧化酶特异性抑制剂作为防治AS新的治疗靶标成为研究者们感兴趣的课题。     

烟酰胺腺嘌呤二核苷酸磷酸氧化酶与心房颤动的研究

心房颤动是最常见的心律失常,其发生和维持的分子机制尚未明确。近年来发现心房颤动存在氧化应激,并已从动物实验、临床试验等多方面证实其主要来源为烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶,推测NADPH 氧化酶可能在心房颤动发生发展过程中起重要作用。以NADPH 氧化酶为靶点的心房颤动干预措施如肾素-血管紧张素系统抑制剂和他汀类等也愈受关注。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.     

A single injection of adrenergic agonists enhances pineal melatonin production in Turkish hamsters

Abstract: The purpose of this study was to determine whether the pineal gland of Turkish hamsters (Mesocricetus brandti) responds to adrenergic agonists with an increase in melatonin production, and, if it does, whether the sensitivity of the pineal gland to agonists would differ throughout the dark phase. Adult Turkish hamsters weighing 110–210 g received a subcutaneous injection of isoproterenol (ISO, 1 mg/kg B.W.) or norepinephrine (NE, 1 mg/kg B.W.) at different times of night. Animals exposed to LD 16:8 responded to ISO or NE with increased pineal melatonin content only when injected at dawn, when endogenous melatonin is at basal or near-basal levels. When the 8 hr scotophase was entirely replaced with light, the responsiveness to ISO injections at dawn disappeared. In animals exposed to light from 30 min prior to injection to the time of sacrifice, ISO injections increased pineal melatonin content (P < 0.005, three-way ANOVA), which varied, depending on the specific time of injection (effect of time of night, P < 0.05, three-way ANOVA). These results demonstrate that (1) adrenergic agonists enhance the production of pineal melatonin in Turkish hamsters, (2) this stimulatory effect takes place late, but not early in the 8 hr scotophase, and (3) the adrenergic induction of pineal melatonin production in Turkish hamsters requires priming by darkness during the appropriate circadian phase.     

Immune effector mechanisms in malaria: An update focusing on human immunity

The past decade has witnessed dramatic decreases in malaria‐associated mortality and morbidity around the world. This progress has largely been due to intensified malaria control measures, implementation of rapid diagnostics and establishing a network to anticipate and mitigate antimalarial drug resistance. However, the ultimate tool for malaria prevention is the development and implementation of an effective vaccine. To date, malaria vaccine efforts have focused on determining which of the thousands of antigens expressed by Plasmodium falciparum are instrumental targets of protective immunity. The antigenic variation and antigenic polymorphisms arising in parasite genes under immune selection present a daunting challenge for target antigen selection and prioritization, and is a given caveat when interpreting immune recall responses or results from monovalent vaccine trials. Other immune evasion strategies executed by the parasite highlight the myriad of ways in which it can become a recurrent infection. This review provides an update on immune effector mechanisms in malaria and focuses on our improved ability to interrogate the complexity of human immune system, accelerated by recent methodological advances. Appreciating how the human immune landscape influences the effectiveness and longevity of antimalarial immunity will help explain which conditions are necessary for immune effector mechanisms to prevail.     

Secondary aortoduodenal fistula

Aorto-duodenal fistulae （ADF） are the most frequent aorto-enteric fistulae （80%）, presenting with upper gastrointestinal bleeding. We report the first case of a man with a secondary aorto-duodenal fistula presenting with a history of persistent occlusive syndrome. A 59-year old man who underwent an aortic-bi-femoral bypass 5 years ago, presented with dyspepsia and biliary vomiting. Computed tomography scan showed in the third duodenal segment the presence of inflammatory tissue with air bubbles between the duodenum and prosthesis, adherent to the duodenum. The patient was submitted to surgery, during which the prosthesis was detached from the duodenum, the intestine failed to close and a gastro-jejunal anastomosis was performed. The post-operative course was simple, secondary ADF was a complication （0.3%-2%） of aortic surgery. Mechanical erosion of the prosthetic material into the bowel was due to the lack of interposed retroperitoneal tissue or the excessive pulsation of redundantly placed grafts or septic procedures. The third or fourth duodenal segment was most frequently involved. Diagnosis of ADF was difficult. Surgical treatment is always recommended by explorative laparotomy. ADF must be suspected whenever a patient with aortic prosthesis has digestive bleeding or unexplained obstructive syndrome. Rarely the clinical picture of ADF is subtle presenting as an obstructive syndrome and in these cases the principal goal is to effectively relieve the mechanical bowel obstruction.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Married to M. tuberculosis: risk of infection and disease in spouses of smear-positive tuberculosis patients

Objectives To quantify the risk of infection and disease in spouses of tuberculosis patients and the extent to which intervention could reduce the risk in this highly exposed group. Methods We compared HIV prevalence, TB prevalence and incidence and tuberculin skin test (TST) results in spouses of TB patients and community controls. HIV‐positive spouses were offered isoniazid preventive therapy (IPT), and TST was repeated at 6, 12 and 24 months. Results We recruited 148 spouses of smear‐positive patients ascertained prospectively and 3% had active TB. We identified 203 spouses of previously diagnosed smear‐positive patients, 11 had already had TB, and the rate of TB was 2.4 per 100 person years(py) over 2 years (95% CI 1.15–5.09). 116 were found alive and recruited. HIV prevalence was 37% and 39% in the prospective and retrospective spouse groups and 17% in controls. TST was ≥10 mm in 80% of HIV negative and in 57% of HIV‐positive spouses ascertained retrospectively; 74% HIV negative and 62% HIV‐positive spouses ascertained prospectively, and 48% HIV negative and 26% HIV‐positive community controls. Of 54 HIV‐positive spouses, 18 completed 6‐month IPT. At 2 year follow‐up, 87% of surviving spouses had TST ≥10 mm and the rate of TB was 1.1 per 100 py (95% CI 0.34–3.29). Conclusions Spouses are a high‐risk group who should be screened for HIV and active TB. TST prevalence was already high by the time the spouses were approached but further infections were seen to occur. Uptake and adherence to IPT was disappointing, lessening the impact of short‐duration therapy.