洋虫对清除体内外亚硝酸钠和阻断二甲基亚硝胺合成的影响

洋虫对亚硝酸钠具有清除作用，其量与清除率之间存在显著的相关关系（ｒ＝０．９９）．体外阻断二甲基亚硝胺合成实验中，洋虫量与阻断率之间也存在相关关系．体内阻断二甲基亚硝胺合成实验中，洋虫组血清谷丙转氨酶显著低于对照组（Ｐ＜０．０１），提示洋虫具有明显的清除亚硝酸盐和阻断亚硝胺合成并保护肝组织的作用．     

间歇性饥饿对亚硝酸钠所致大鼠海马神经细丝过度磷酸化及空间学习记忆损伤的改善作用

目的探讨间歇性饥饿对亚硝酸钠诱导的大鼠海马神经细丝(NF)过度磷酸化及空间学习记忆的影响。方法 36只大鼠随机分为对照组、亚硝酸钠组、饥饿+亚硝酸钠组,每组12只。亚硝酸钠组大鼠饮亚硝酸钠水[水中溶入亚硝酸钠粉剂100 mg/(kg·d)],正常喂食;饥饿+亚硝酸钠组大鼠饮亚硝酸钠水,采取饥饿2d,恢复喂食3d的喂食方法,喂养60 d后通过Morris水迷宫实验检测各组大鼠的空间学习记忆能力,免疫印迹和免疫组织化学方法检测大鼠海马NF磷酸化水平与分布。结果与对照组相比,亚硝酸钠组大鼠第2天至第7天的潜伏期[(53.34±5.28)s,(35.15±10.29)s,(23.52±9.50)s,(14.49±8.70)s,(16.87±8.77)s,(12.31±7.12)s]明显大于对照组[(31.24±8.53)s,(12.41±6.54)s,(10.49±6.43)s,(8.61±2.56)s,(7.25±2.12)s,(6.03±1.92)s](P0.01或P0.05),跨越平台的次数(1.18±0.82)明显小于对照组(3.96±0.54,P0.05);饥饿+亚硝酸钠组只有大鼠第2天至第3天的潜伏期[(43.61±1.76)s,(25.25±7.49)s]大于对照组(P0.05),第4天至第7天的潜伏期[(19.47±8.30)s,(10.77±6.28)s,(12.05±7.49)s,(10.29±7.52)s]与对照组相比差异无统计学意义(P0.05)。免疫印迹和免疫组织化学结果显示,亚硝酸钠导致海马NF的磷酸化水平升高,而饥饿+亚硝酸钠组与对照组相比无明显变化。结论饥饿处理可改善亚硝酸钠导致的大鼠海马神经细丝过度磷酸化及空间学习记忆损伤。     

Effects of Oral Supplementation With Nitrate-Rich Beetroot Juice in Patients With Pulmonary Arterial Hypertension—Results From BEET-PAH,an Exploratory Randomized,Double-Blind,Placebo-Controlled,Crossover Study

Background

The nitrate–nitrite–nitric oxide (NO) pathway may represent a potential therapeutic target in patients with pulmonary arterial hypertension (PAH). We explored the effects of dietary nitrate supplementation, with the use of nitrate-rich beetroot juice (BRJ), in patients with PAH.

Adverse ophthalmic reaction in poppers users: case series of ‘poppers maculopathy'

Background

Poppers are a recreational substance of abuse belonging to the alkyl nitrite family of compounds. In the United Kingdom, where they are legal to purchase but illegal to sell for human consumption, 10% of the general population have tried them. They are considered low risk to physical and mental health. Two recent case series from France demonstrated foveal pathology in individuals associated with poppers use.

Method

A case series of seven patients presenting to four hospitals in the United Kingdom with visual impairment and maculopathy associated with inhalation of poppers.

Results

All patients experienced visual symptoms associated with poppers use. The majority had impaired visual acuity, central scotomata, distortion, or phosphenes. Clinical signs on fundoscopy ranged from normal foveal appearance to yellow, dome-shaped lesions at the foveola. Spectral domain optical coherence tomography (SD-OCT) showed varying degrees of disruption of the presumed inner segment/outer segment (IS/OS) junction.

Discussion

Although poppers have been in use for several decades, in 2007, following legislative changes, there was a change in the most commonly used compound from isobutyl nitrite to isopropyl nitrite. There were no reports of ‘poppers maculopathy'' before this. Poppers maculopathy may be missed if patients are not directly questioned about their use. The disruption or loss of the presumed IS/OS junction on SD-OCT are a characteristic feature. Further study of maculopathy in poppers users is now needed. Raising public awareness of the ocular risks associated with their use may be necessary.     

一起农村家庭误食亚硝酸盐引起的食物中毒

该文报道一起误食亚硝酸盐引起的食物中毒案例。食物中毒者为某农村居民家庭成员,其临床表现以呕吐、恶心、乏力、手麻、面色青紫、脱水、呼吸困难、昏迷为主,其中一位中毒者食用中毒食品的量较大,在某医院死亡;另一位中毒者经解毒剂亚甲蓝（美蓝）、维生素C、催吐、补液及其它对症治疗,治疗后中毒症状明显好转,4天后痊愈出院。该次食物中毒警示,亚硝酸盐是一种有毒产品,误食可导致急性中毒或死亡,建议各级有关部门要加大《食品安全法》宣传力度,在农村广泛开展食品安全相关健康知识宣传活动,不断增强农村居民自我保护意识,防止类似食物中毒事件不再发生。     

Increased exhaled nitrite in children with allergic asthma is not related to nitric oxide formation

Introduction: Nitrite sampled from the upper airways could originate from inflammation‐induced nitric oxide (NO), as reports of elevated nitrite in exhaled breath condensate (EBC) from asthmatics suggest, but also through bacterial action in the pharyngo‐oral tract. Objectives: To correlate EBC nitrite and nitrate to exhaled NO (FENO, fraction of expired NO) and other markers of disease activity in children with allergic asthma and thereby further investigate their role and origin. Materials and methods: EBC was collected from 27 asthmatic subjects (ages 6–17 years, all immunoglobulin E‐positive for aeroallergens) and 21 age‐matched non‐atopic healthy controls for fluorometric analysis of nitrite and nitrate. These markers were compared with measurements of FENO, blood eosinophil count (EOS), methacholine reactivity (PD₂₀) and baseline spirometry. Results: EBC nitrite, in contrast to nitrate, was significantly increased (P < 0.01) in the asthmatic children. They also had increased levels of FENO (P < 0.001) and EOS (P < 0.001) along with decreased PD₂₀ (P < 0.001) and FEV1/FVC (P < 0.01). However, there was no correlation between EBC nitrite and FENO (r = 0.05) or any other marker of disease activity in the asthmatic children, whereas between the other markers correlations could be established. Conclusion: EBC nitrite is elevated in childhood asthma but the lack of correlation to FENO and other markers, together with simultaneously normal levels of nitrate, make its origin as a metabolite of inflammation‐induced NO questionable. Please cite this paper as: Zetterquist W, Marteus H, Hedlin G and Alving G. Increased exhaled nitrite in children with allergic asthma is not related to nitric oxide formation. The Clinical Respiratory Journal 2008; 2: 166–174.     

Detection of coronary artery disease by vasodilator thallium imaging of the heart with amyl nitrite inhalation: a pilot study.

Thallium imaging of the heart using dipyridamole-induced coronary arteriolar vasodilation has proven to be an effective means of detecting significant coronary stenosis. However, intravenous dipyridamole has not yet been made available for general use. We therefore examined the feasibility of substituting amyl nitrite inhalation as an arteriolar vasodilator prior to thallium imaging. Seventeen patients, all of whom had catheterization-proven coronary stenosis, inhaled amyl nitrite for 2-5 min. Thallium was injected after 45-60 s of inhalation. Completion of inhalation was followed immediately by planar imaging. Of 6 patients who inhaled amyl nitrite for at least 4 min, 5 had moderate or severe image defects on immediate scans which completely resolved on delayed scans. Only 3 of 11 who inhaled amyl nitrite for 2 min or less prior to scanning had similarly positive tests. Overall sensitivity for significant stenosis was 8 of 17 (47%). Inhalation was well tolerated with only one episode of angina and hypotension. We conclude that amyl nitrite inhalation for at least 4 min may offer an effective and readily available alternative to intravenous dipyridamole for vasodilator imaging of the heart.     

亚硝酸盐对培养心肌细胞的直接作用

应用亚硝酸钠作用于培养的心肌细胞，观察到心肌细胞发生了超微形态结构改变；细胞内α－羟丁酸脱氢酶漏出增加（Ｐ＜０．０５～０．０１），３Ｈ—ＴｄＲ掺入变化呈双向性：小剂量组（０．００１～０．１×１０－６ｍｏｌ／Ｌ）呈现促进作用（Ｐ＜０．０５～０．０１）；大剂量组（１．０×１０－６ｍｏｌ／Ｌ）则表现为抑制效应（Ｐ＜０．０５）。细胞周期分析结果：小剂量组（０．０１×１０－６ｍｏｌ／Ｌ）Ｇ０Ｇ１期细胞减少４．１３％，Ｓ期增长３．９５％，Ｇ２＋Ｍ期增长０．３３％，与对照组比较，无显著性差异（Ｐ＞０．０５）。大剂量组（１、０×１０－６ｍｏｌ／Ｌ）Ｇ０Ｇ１期细胞增加９．１４％，Ｓ期减少１２．４６％，Ｇ２＋Ｍ期增加４．０６％，其中Ｓ期的改变达到显著差异（Ｐ＜０．０５）；细胞及培养液中脂质过氧化物含量增加（Ｐ＜０．０１）。表明亚硝酸盐能引起培养心肌细胞的直接损伤，其机理与脂质过氧化作用有关。     

NO pathway in CF and non-CF children

Controversy exists concerning abnormalities of the nitric oxide (NO) pathway in cystic fibrosis (CF) lung disease. Although some studies suggested that NO activity is impaired in CF, changes in NO production in young children have not been studied. We hypothesized that nitric oxide synthase (NOS II) expression is decreased in young children with CF, leading to decreased production of lower airway NO, and that decreased NOS II expression is related to airway inflammation. Accordingly, we measured lower airway exhaled NO, nitrate, and NOS II expression in airway epithelium and macrophages by bronchoscopy, bronchoalveolar lavage (BAL), and bronchial brushing in 13 children with CF, 4 adolescent patients with CF, and 14 disease control children. Lower airway NO and nitrate were not different between CF and disease controls. Immunostaining studies of NOS II expression in airway epithelial cells and macrophages were similar in CF and control patients. Within the CF group, however, expression of NOS II was inversely related to BAL neutrophil counts and IL-8, two markers of airway inflammation. We conclude that lower airway NO, nitrate levels, and NOS II expression are not different in young children with CF and disease control patients, but that NOS II expression decreases in CF as airway inflammation increases.     

亚硝酸钠对心肌谷胱甘肽过氧化物酶的影响及维生素E和硒的保护作用

大白鼠喂饲克山病病区粮,并分别向病区粮加维生素 E 和硒,观察在亚硝酸钠急性中毒情况下各组大鼠心肌谷胱甘肽过氧化物酶的变化。结果表明,亚硝酸钠可使病区粮所饲大鼠心肌谷胱甘肽过氧化物酶活性明显下降,补充维生素 E 或硒则可保护此酶活性防止其下降。提出除低硒外,亚硝酸盐过多及维生素 E 缺乏可能参与了克山病发病环节。