荷包牡丹碱对抗γ-氨基丁酸对伏核痛反应神经元电活动的影响

目的:探讨γ-氨基丁酸、荷包牡丹碱对正常大鼠伏核内痛反应神经元电活动的影响。方法:实验于2004-05/2005-05在哈尔滨医科大学神经痛觉电生理研究室完成。选用健康、成年Wistar系大鼠50只。随机分γ-氨基丁酸组(20只)和生理盐水对照组(5只);γ-氨基丁酸 荷包牡丹碱组(20只)和生理盐水对照组(5只)。大鼠麻醉后,实施常规手术。将不锈钢套管插入侧脑室供注药用。①γ-氨基丁酸组内匀速注入γ-氨基丁酸(50g/L,10μL);②γ-氨基丁酸 荷包牡丹碱组在注入γ-氨基丁酸后2min,向侧脑室内再注入荷包牡丹碱(1g/L,10μL),用等体积生理盐水作为对照实验。实验采用电生理学的方法,以电脉冲刺激坐骨神经作为伤害性痛刺激。用玻璃微电极记录痛反应神经元放电的变化,并连续观察和记录痛反应神经元的电变化30min。结果:Wistar大鼠50只在实验过程中无脱失值,全部进入结果分析。侧脑室注入γ-氨基丁酸能使正常大鼠伏核中痛兴奋神经元痛诱发放电频率的净增值由注药前的(8.59±1.17)Hz减少至(-1.38±0.51)Hz、潜伏期由(0.17±0.04)s延长至(0.69±0.08)s,而痛抑制神经元的净增值由注药前的(-4.34±0.37)Hz增加至(5.12±1.58)Hz、完全抑制时程由(0.72±0.08)s缩短至(0.27±0.03)s。②侧脑室注入γ-氨基丁酸A受体拮抗剂荷包牡丹碱可对抗γ-氨基丁酸的作用,即痛兴奋神经元的净增值增加到(6.61±1.23)Hz,潜伏期缩短至(0.18±0.08)s;痛抑制神经元的净增值减少为(-1.33±0.21)Hz,抑制时程延长至(0.69±0.06)s。痛兴奋神经元和痛抑制神经元两者相互配合活动。结论:①外源性γ-氨基丁酸可使正常大鼠伏核中痛兴奋神经元和痛抑制神经元对伤害性刺激的反应均减弱,表现出镇痛效应。②γ-氨基丁酸的镇痛作用主要是通过γ-氨基丁酸A受体介导的。γ-氨基丁酸和伏核在痛觉调制中具有重要的作用。③荷包牡丹碱可对抗γ-氨基丁酸的作用。     

Identification of Shiga-Toxin-Producing Shigella Infections in Travel and Non-Travel Related Cases in Alberta,Canada

It has long been accepted that Shiga toxin (Stx) only exists in Shigella dysenteriae serotype 1. However, in recent decades, the presence of Shiga toxin genes (stx) in other Shigella spp. have been reported. We screened 366 Shigella flexneri strains from Alberta, Canada (2003 to 2016) for stx and 26 positive strains were identified. These isolates are highly related with the majority originating from the Dominican Republic and three isolates with Haiti origin. Both phylogenetic and spanning tree analysis of the 26 Alberta and 29 stx positive S. flexneri originating from the U.S., France, Canada (Quebec) and Haiti suggests that there are geographic specific distribution patterns (Haiti and Dominican Republic clades). This study provides the first comprehensive whole genome based phylogenetic analysis of stx positive S. flexneri strains as well as their global transmission, which signify the public health risks of global spreading of these strains.     

Effectiveness of skin cleanser and protectant regimen on incontinence‐associated dermatitis outcomes in acute care patients: A cluster randomised trial

Skin cleansers and protectants protect skin from incontinent matter to reduce the risk of incontinence‐associated dermatitis (IAD), but their effectiveness treating established IAD in the tropics is unknown. We conducted an open‐label cluster randomised trial to compare the effectiveness of a combined regimen of (1) specialised skin cleansers with disposable body wipes and (2) either an acrylic terpolymer (T1) or zinc oxide (T2) skin protectant against disposable body wipes and zinc oxide protectant (control) in promoting IAD healing and reducing the risk of deterioration. Eighty‐four patients were recruited in a tertiary hospital in Singapore between April 2019 and January 2020 (T1: n = 23; T2: n = 37; Control: n = 24). Although not statistically significant, patients treated with T1 and T2 were 1.5 times as likely to experience IAD healing within seven days compared with the control (P = .66). Healing was more pronounced in participants with skin loss treated with T1 or T2. No treatment was superior in preventing IAD deterioration, the prevalence of which remained small (8%‐14%). While skin cleaning and protectants reduced the overall risk of skin deterioration, the addition of skin cleansers enhanced IAD healing within a short period, an important consideration for future research examining IAD treatment in acute care.     

主诊医师负责制下医院感染管理模式探讨

针对主诊医师负责制医疗改革的举措,医院探索了一套医院感染管理模式和控制方法。通过成立医院感染控制中心,建立绩效考核机制,注重信息化建设和继续教育管理。使医院感染管理得到了持续的改进,降低了医院感染发生率,提高了医疗工作质量和效率。     

某医院非计划二次手术临床分析

目的为提高手术质量,确保诊疗安全提供管理依据。方法提取某医院2009年医疗统计系统资料,对19个手术相关科室发生非计划二次手术情况进行分析。结果 2009年全院19个手术科室共开展手术32 508例,发生非计划二次手术124例,发生率为0.38%;占比最高的为胸心外科,术后出血、感染、切口问题、吻合口瘘是发生非计划二次手术的主要原因。结论非计划二次手术的发生与手术者专业水平、操作技术、患者病情因素及手术病种因素有关,应强调加强围手术期重点科室、重点环节、重点病例和重点人群的安全监控。     

Severity of β-thalassemia due to genotypes involving the IVS-I-6 (T→C) mutation

Among individuals of Mediterranean or Middle Eastern descent, the IVS-I-6 (T→C) mutation is one of the most common causes of β-thalassemia. In this report, we describe the clinical phenotypes of a group of β-thalassemia patients who are compound heterozygotes for the relatively mild IVS-I-6 (T→C) β-thalassemia mutation and more severe β⁺- or β°-thalassemia mutations. Although most of these patients are transfusion-dependent, the requirement for regular transfusions generally occurred late in childhood. A correlation between concomitant α-thalassemia and a mild transfusion-independent phenotype is not apparent, indicating the involvement of other ameliorating determinants.     

Cultured human ocular surface epithelium on therapeutic contact lenses

BACKGROUND: This study was initiated after observation of some intriguing epithelial growth properties of contact lenses used as a bandage for patients after pterygium surgery. AIM: To determine the efficacy of culturing human ocular surface epithelial cells on therapeutic contact lenses in autologous serum with a view of using this system to transfer epithelial cells to patients with persistent corneal or limbal defects. METHODS: Excess graft tissue resected from patients undergoing pterygium surgery (n = 3) consisting of limbal epithelium was placed on siloxane-hydrogel contact lenses (lotrafilcon A and balafilcon A). Limbal explants were cultured in media with 10% autologous serum. Morphology, proliferative capacity and cytokeratin profile were determined by phase contrast, light and electron microscopy, and immunohistochemical analysis. RESULTS: Lotrafilcon A contact lenses sustained proliferation and migration from limbal tissue. Cells became confluent after 10-14 days and consisted of 2-3 layers with a corneal phenotype (CK3(+)/CK12(+)/CK19(-)) and a propensity to proliferate (p63(+)). Electron microscopy showed microvilli on the apical surface with adhesive projections, indicating that these cells were stable and likely to survive for a long term. Growth was not observed from limbal explants cultured on balafilcon A contact lenses. CONCLUSION: A method for culturing human ocular surface epithelium on contact lenses that may facilitate expansion and transfer of autologous limbal epithelial cells while avoiding the risks associated with transplanting allogeneic tissue has been developed. This technique may be potentially useful for the treatment of patients with limbal stem cell deficiency.     

Transgenic cyclooxygenase-2 expression and high salt enhanced susceptibility to chemical-induced gastric cancer development in mice

Cyclooxoygenase (COX)-2 overexpression is involved in gastric carcinogenesis. While high-salt intake is a known risk factor for gastric cancer development, we determined the effects of high salt on gastric chemical carcinogenesis in COX-2 transgenic (TG) mice. COX-2 TG mice were developed in C57/BL6 strain using the full-length human cox-2 complementary DNA construct. Six-week-old COX-2 TG and wild-type (WT) littermates were randomly allocated to receive alternate week of N-methyl-N-nitrosourea (MNU, 240 p.p.m.) in drinking water or control for 10 weeks. Two groups of mice were further treated with 10% NaCl during the initial 10 weeks. All mice were killed at the end of week 50. Both forced COX-2 overexpression and high-salt intake significantly increased the frequency of gastric cancer development in mice as compared with WT littermates treated with MNU alone. However, no additive effect was observed on the combination of high salt and COX-2 expression. We further showed that MNU and high-salt treatment increased chronic inflammatory infiltrates and induced prostaglandin E(2) (PGE(2)) production in the non-cancerous stomach. Whereas high-salt treatment markedly increased the expression of inflammatory cytokines (tumor necrosis factor-alpha, interferon-gamma, interleukin (IL)-1 beta and IL-6) in the gastric mucosa, COX-2 overexpression significantly altered the cell kinetics in the MNU-induced gastric cancer model. In conclusion, both high salt and COX-2 overexpression promote chemical-induced gastric carcinogenesis, possibly related to chronic inflammation, induction of PGE(2), disruption of cell kinetics and induction of inflammatory cytokines.     

The use of mini-dose suxamethonium to facilitate the insertion of a laryngeal mask airway

The use of mini-dose suxamethonium to facilitate the insertion of a laryngeal mask airway was investigated. Sixty patients were assigned randomly in a double-blind manner to receive 0.9% sodium chloride or suxamethonium 0.1 mg.kg-1 intravenously, following intravenous induction with propofol 2.5 mg.kg-1. The laryngeal mask was inserted after the first attempt in 87% of patients. Mini-dose suxamethonium improved the correct positioning of the laryngeal mask during the first attempt (93 vs. 67%, p < 0.02), decreased the incidence of swallowing (p < 0.001), gagging (p < 0.001) and head or limb movement (p < 0.05). Laryngeal mask insertion was graded as easy in 93% of patients who had mini-dose suxamethonium, compared with 60% in the placebo group (p < 0.01). The duration of apnoea between the two groups was not significantly different (0.54 vs. 0.61 min, p = 0. 46). The total dose of propofol needed to insert the laryngeal mask was lower in the suxamethonium group (2.57 vs. 3.25 mg.kg-1, p < 0. 01) and was associated with less hypotension (p < 0.05). Fasciculation (17%) and mild myalgia (23%) were common despite the small dose of suxamethonium used. In conclusion, mini-dose suxamethonium facilitates laryngeal mask insertion. Myalgia is common and the technique is not recommended for patients who are prone to suxamethonium myalgia.