Reactive oxygen species and anti-oxidant defences in swine follicular fluids

A growing body of evidence indicates that the pro-oxidant/anti-oxidant balance inside the ovarian follicle plays an important role in folliculogenesis. Therefore, the aim of the present study was to assess the redox status of follicular fluids collected from different-sized swine follicles. We quantified the most important reactive oxygen species (ROS), namely superoxide anion (O(2)(-)), hydrogen peroxide and hydroperoxides (ROOH); in addition, we examined the activity of the detoxifying enzymes superoxide dismutase, catalase (CAT) and glutathione peroxidase and the total non-enzymatic antioxidant capacity as determined by the ferric-reducing anti-oxidant power assay. Our data demonstrate that oxidative stress does not affect follicle growth because O(2)(-) levels do not change during follicle development, whereas concentrations of H2O2 and ROOH are reduced (P < 0.05). Surprisingly, all non-enzymatic and enzymatic scavengers examined in the present study, except for CAT, demonstrated reduced activity during follicle development (P < 0.05). Taken together, these results suggest that other factors could be involved in ROS detoxification during follicle development.     

Reactive oxygen metabolites produced by the carcinogenic fibrous mineral erionite

Erionite, a fibrous mineral and the causative agent of the endemic outbreak of mesothelioma in Turkey, has been shown to generate reactive oxygen metabolites (ROM) from polymorphonuclear leukocytes (PMN). In order to investigate the mechanism of the production of ROM by erionite from PMN, a luminol-dependent chemiluminescence (CL) method was utilized. Human peripheral blood PMN were incubated with 50-800 micrograms/ml of erionite. PMN CL was produced immediately after the addition of erionite; the maximal CL production was reached within 2 to 6 min and the CL response increased with the dose of erionite. Superoxide dismutase, catalase, and dimethyl sulfoxide were utilized as scavengers of O2-, H2O2, and OH., respectively. These scavengers inhibited the production of erionite-stimulated PMN CL dose dependently, thus indicating the production of O2-, H2O2, and OH. by erionite-stimulated PMN. The less phagocytically active cells, namely, mononuclear cells and erythrocytes, produced CL immediately after the addition of erionite or phorbol myristate acetate and displayed a significant delay period after the addition of zymosan. Therefore, the direct interaction between the cell surface membrane and erionite would appear to be more important than phagocytosis, per se, for the production of ROM by erionite.     

Reactive oxygen metabolites as an index of chronic obstructive pulmonary disease severity

AIM: The purpose of this study was to determine whether reactive oxygen metabolite species (ROMs) correlated with lung function in patients with chronic obstructive pulmonary disease (COPD) and to investigate whether ROMs could be used as an index of COPD severity. METHODS: ROMs were evaluated in plasma by a colorimetric method (d-ROM-test) in 94 patients with COPD and in 31 healthy nonsmokers subjects. Spirometry, exhaled carbon monoxide and pulse oxymetry was performed in all patients. RESULTS: Mean plasma ROMs were significantly increased (330.38 Carratelli units) in patients with COPD. There was a negative correlation of ROMs with forced expiratory volume in the first second (r= -0.275, P<0.007), with forced vital capacity (r= -0.278, P<0.007), with forced expiratory flow (r= -0.226, P<0.029) and with oxygen saturation (r= -0.315, P<0.010). In addition a positive correlation was found between the age of the patients and the oxidative stress (r= 0.366, P<0.000). CONCLUSIONS: These data indicate the presence of systemic oxidative stress in patients with COPD. The increased oxidative stress in COPD patients was concomitant with the impairment of lung function.     

Reactive oxygen species in male infertility. Review of literature and personal observations

Reactive oxygen species, highly reactive molecules derived from the metabolism of oxygen, play an important role in the metabolism of spermatozoa, related to the hyperactivated motility and acrosome reaction. Various studies have demonstrated that these molecules, because of their reactivity, can induce peroxidative damage on the cell, especially on the lipid membranes. The spermatozoa, owing to their structure, appear to be very sensitive to the oxidative insult. Various experimental data sustain the hypothesis that, when produced in high amounts, reactive oxygen species can induce sperm damage and become potentially responsible for some forms of unexplained infertility. The cells possess various mechanisms of defense against the oxidative insult, mainly due to antioxidant molecules. An antioxidant treatment can produce an improvement in seminal parameters and sperm function in vitro, and represents a possible form of care for selected forms of infertility.     

Reactive oxygen species production is involved in quercetin-induced apoptosis in human hepatoma cells

Hepatocellular carcinoma (HCC) is the leading cause of cancer mortality in Asia. The aim of this study was to examine whether reactive oxygen species production is involved in quercetin-induced apoptosis in human HCC cell lines. Quercetin inhibited the growth of hepatoma cells in dose and time dependent manners. Quercetin treatment of hepatoma cells resulted in changes of cell cycle progression. The G0/G1phase was decreased and S phase was increased in HA22T/VGH cells after treatment with quercetin. The levels of apoptotic sub-G0/G1, reactive oxygen species and annexin V were increased prior to cell death and concurrent with lipid peroxidation in two human hepatoma cells after treatment with quercetin. Quercetin also enhanced the apoptotic effect of the chemotherapeutic agent, paclitaxel, in HA22T/VGH cells. Quercetin has therapeutic potential as an anti-cancer drug. These results provide basis for further study into the potential use of quercetin in combination with paclitaxel for treatment of hepatoma.     

Reactive oxygen intermediates and reactive nitrogen intermediates in copper intrauterine device users.

The mechanism of action of copper in copper intrauterine devices (Cu IUD) as an antimicrobial agent is not well understood. Copper and iron are supposed to be responsible for release of reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI), which are very active in the presence of infection. The copper in a copper IUD could be responsible for limiting pelvic inflammatory disease. The present study was composed of 20 IUD seekers in whom ROI and RNI were studied before insertion of Cu IUD and then at 1, 4, and 12 weeks afterward. ROI showed a rise after insertion, whereas RNI showed a steady decline. Hence, it is presumed that the rise in ROI could be responsible for both the bactericidal effect of Cu IUD and also for the fall in RNI.     

Reactive oxygen metabolite production induced by asbestos and glass fibers: effect of fiber milling

Particle stimulated chemiluminescence (CL) production by human polymorphonuclear leucocytes (PMN) has been utilized to evaluate the pathogenicity of mineral and glass fibers with the understanding that reactive oxygen metabolites (ROM) production as measured by CL is etiopathogenically related to fiber toxicity. In the present study to investigate the specific pathogenic role of fiber number and dimensions, CL production from PMN exposed to anthophyllite asbestos mineral and glass fiber samples milled for different time periods was measured. Almost all the fibrous particles in the glass fiber sample were destroyed after milling for 30 minutes. With anthophyllite, the total number of fibrous particles remained almost constant for up to 240 minutes of milling, although the size of fibrous particles was reduced. CL produced by the same mass of glass fiber was elevated after milling for 15 minutes, but then declined when the milling time was further increased. Similarly, with anthophyllite, the production of CL was elevated at the first period of milling for 30 minutes, but then declined at the longer milling times. The level of CL produced was not correlated to the total number of fibrous particles, for both the glass fiber and the anthophyllite samples. Likewise for the glass fiber and anthophyllite samples, no specific range of fiber dimension was correlated to the peak hight CL production. These findings indicate that neither the total number, nor the specific range of fiber dimension solely determines CL production. As a consequence, it may be concluded that other physiochemical factors, such as the surface reactive characteristics of milled fibers, may be more closely related to CL production by PMN.     

亚砷酸钠诱导的活性氧增加人皮肤细胞N6 -甲基腺苷水平

目的 探究亚砷酸钠诱导的活性氧是否影响N6 -甲基腺苷（m6A）水平,从RNA表观遗传学角度探讨亚砷酸钠的毒性机制。方法 以亚砷酸钠作为活性氧诱导剂,以N -乙酰半胱氨酸作为活性氧清除剂,检测细胞在亚砷酸钠单独处理和亚砷酸钠联合N -乙酰半胱氨酸处理情况下皮肤细胞活性氧积累情况,同时测定m6A及其甲基化酶的mRNA和蛋白水平的改变。结果 在5、10和15 μM的亚砷酸钠处理下,活性氧含量随砷浓度升高而增加;在亚砷酸钠染毒浓度为15 μM时,细胞内总m6A水平水平相比于对照组升高了1.49倍（P＜0.05）,m6A甲基化酶（METTL3、METTL14和WTAP）mRNA表达水平相应升高（P＜0.05）,METTL14和WTAP蛋白表达水平分别为对照组的1.47倍和1.85倍（P＜0.05）。N -乙酰半胱氨酸可以降低异常升高的活性氧、m6A以及其甲基化酶水平。结论 亚砷酸钠诱导的活性氧能增加人皮肤细胞m6A的修饰水平,其机制可能与上调m6A甲基化酶表达水平有关。     

Reactive oxygen species induced by diamide inhibit insulin-induced ATP-sensitive potassium channel activation in cultured vascular smooth muscle cells

Both insulin resistance and reactive oxygen species (ROS) have been reported to play essential pathophysiological roles in cardiovascular diseases. However, the mechanistic link between ROS and insulin resistance in the vasculature remains unclear. Recently we have shown that insulin causes KATP channel activation mediated by PI3K in cultured vascular smooth muscle cells (VSMCs). KATP channel in VSMCs is critical in the regulation of vascular tonus. Here we examined the effects of ROS induced by a thol-oxidizing agent, diamide, on the insulin signalling pathway and KATP channel activities in cultured VSMCs (A10 cells). Diamide (100 microM) increased intercellular ROS and extracellular signal-regulated kinases (ERK) activity. Treatment with 100 M diamide suppressed significantly insulin-induced IRS and Akt phosphorylation. In addition to IRS and Akt, diamide inhibited insulin receptor auto-phosphorylation. Patch-clamp study showed that diamide suppressed insulin-induced but did not pinacidil-induced KATP channel activities in A10 cells. From these data, we conclude that ROS inhibit critical insulin signal transduction components including IRS and Akt, and these effects cause down-regulation of insulin's action in the vasculature including KATP channel activation. This study may contribute to our understanding of mechanisms of insulin resistance-associated cardiovascular disease.     

Reactive arthritis

Reactive arthritis are definied as steriles arthropathies using classic bacteriological techniques. They are due to extra articular infection and are often associated with HLA B27. The outcome of these arthritis is characterised by the recurrence of flares with sometimes appearition of ankylosing spondylitis. The pathogenesis of reactive arthritis is modified when bacterial antigens or alive micro-organisms are discovered in involved joints. Several current works have underlined the interest of antibiotic therapy in the chlamydial reactive arthritis. Chronic forms can justify the use of anti-rheumatic drugs such as salazopyrine.     

Reactive airways dysfunction syndrome

Reactive airways dysfunction syndrome, better known as RADS, was described as a clinical entity consisting in the appearance of bronchial asthma due to massive toxic inhalation. The term was coined and recognised for the first time in 1985. Since then different publications have verified new cases as well as different causal agents. It usually arises from an accident at the work place and in closed or poorly ventilated spaces, where high concentrations of irritant products are inhaled in the form of gas, smoke or vapour. In the following minutes or hours symptoms of bronchial obstruction appear in an acute form, with bronchial hyperresponsiveness persisting for months or years. The affected patients do not show a recurrence of symptoms following exposure to non-toxic doses of the same agent that started the symptoms. This is why diagnosis is based on clinical manifestations as it is not reproducible through a provocation test.     

反应性气道功能障碍综合征

1　一般情况反应性气道功能障碍综合征 (ＲＡＤＳ) ,1985年首先由Ｂｒｏｏｋｓ提出并命名[1～ 3] ,是由于接触高浓度腐蚀性气体、蒸气、烟雾后突然出现的一种哮喘 ,而且反复发作持续较长时间。本病与以往典型的职业性哮喘 (ＯＡ)不同 ,其发病迅速 ,与环境中接触高浓度刺激性气体有关 ,缺少免疫或过敏的特征 ,但具有哮喘的共同特征即气道高反应性 ,因此认为是一种特殊类型的由刺激性气体所致哮喘 ,也是职业性哮喘的一种特殊形式。有人认为从严格意义上说ＲＡＤＳ不属于ＯＡ。这主要取决于对ＯＡ的不同定义 ,在原有的定义中认为只有工作环境中…     

Reactive macrophage activation syndrome

Reactive macrophage activation syndrome or haemophagocytic lymphohistiocytosis is a life-threatening immunoregulatory disorder characterized by the activation of the mononuclear phagocytic system with prominent haemophagocytosis particularly involving the bone marrow, reticuloendothelial system and central nervous system. It frequently occurs in children as a familial autosomal recessive disorder and it has been reportedly associated with infections, underlying hematopoetic malignancies or autoimmune disorders. It has been suggested that central to the pathogenesis of this disorder is uncontrolled T-cell activation which results in the excessive secretion of cytokines. The clinical and laboratory findings are dramatic, at presentation with persistent fever, hepatosplenomegaly, profound depression of three blood cell lines, elevated serum liver enzyme values, coagulopathy and abundant haemophagocytosis can be visualized in bone marrow. Most of the described clinical findings could be explained by the oversecretion of proinflammatory cytokines and the presence of histiocytic infiltrates. In general, immunosuppressive therapy, cytotoxic chemotherapy with immunomodulatory agents will induce remissions in a substantial percentage of patients, whereas others require allogenic bone marrow transplantation.     

脉冲吸氧与脉冲吸氧仪

本文介绍了“脉冲吸氧”的机理和脉冲吸氧仪的电原理及优越性。增加吸氧效果，减少感染，大大地降低氧损耗量。该仪器的广泛应用将使病人更加安全舒适。     

Reactive Arthritis: A Review

This review article summarizes the available literature on adolescent reactive arthritis. A review of the pathophysiology, diagnosis, and treatment guidelines will be helpful to better diagnose and treat reactive arthritis.     

Reactive arthritis following Chlamydia infection

The authors report on the clinical observation of 23 patients (5 women, 18 men) who suffered from seronegative spondylarthritis following chlamydia infection diagnosed clinically and serologically. Nine patients (2 women, 7 men) carried HLA B27 histocompatibility antigen. Sacroileitis confirmed by radiology was found in 16 cases. Genicular synovitis was the most frequent peripheral articular syndrome as well as Achilles tendinitis, "sausage-like" swelling of the finger and toes were observed and the ankle-, wrist-, elbow- and in a few cases the sternoclavicular and temporomandibular joint showed also involvement. Urological inflammation occurred in 9 cases, ophthalmological inflammation in 3 cases and pleuritis, pericarditis was observed in 1 patient. During the observation period 15 patients recovered upon Doxycyclin (Chinoin), Eryc (Biogal) non-steroid and occasional steroid therapy given 3 weeks long.     

Reactive arthritis due to Clostridium difficile

Extracolonic manifestations of Clostridium difficile infections have rarely been reported as a cause of reactive arthritis. We report the case of a monoarticular arthritis following pseudomembranous colitis. A 45 year-old man was admitted for fever and monoarthritis of the left knee, 8 days after the onset of a C. difficile enterocolitis associated with urethritis. Samples obtained from the knee, urine, and blood cultures remained sterile. Bone scintigraphy revealed a left knee and forefoot hyperfixations. The association of arthritis and urethritis led us to the diagnosis of Fiessinger-Leroy-Reiter syndrome. Antibiotics for arthritis were ineffective and stopped, but they were continued for colitis. NSAIDs were prescribed and clinical manifestations disappeared within 24 hours, the patient resumed walking after 48 hours. Four months later there was no relapse and no sequela.