Chronic effects of cannabis on sensory gating

Chronic cannabis use has been associated with neurocognitive deficits, alterations in brain structure and function, and with psychosis. This study investigated the effects of chronic cannabis use on P50 sensory-gating in regular users, and explored the association between sensory gating, cannabis use history and the development of psychotic-like symptoms. Twenty controls and 21 regular cannabis users completed a P50 paired-click (S1 and S2) paradigm with an inter-pair interval of 9 s. The groups were compared on P50 amplitude to S1 and S2, P50 ratio (S2/S1) and P50 difference score (S1–S2). While cannabis users overall did not differ from controls on P50 measures, prolonged duration of regular use was associated with greater impairment in sensory gating as indexed by both P50 ratio and difference scores (including after controlling for tobacco use). Long-term cannabis users were found to have worse sensory gating ratios and difference scores compared to short-term users and controls. P50 metrics did not correlate significantly with any measure of psychotic-like symptoms in cannabis users. These results suggest that prolonged exposure to cannabis results in impaired P50 sensory-gating in long-term cannabis users. While it is possible that these deficits may have pre-dated cannabis use and reflect a vulnerability to cannabis use, their association with increasing years of cannabis use suggests that this is not the case. Impaired P50 sensory-gating ratios have also been reported in patients with schizophrenia and may indicate a similar underlying pathology.     

Influence of MRE11, RAD50 and NIBRIN protein expression on survival in pancreatic carcinoma after curative resection

The MRE11/RAD50/NIBRIN complex, a protein complex that repairs DNA double-strand breaks, could serve as an early marker for new lesions in pancreatic cancer. We determined the expression of MRE11, RAD50 and NIBRIN, and their possible prognostic value regarding survival.     

Blunted muscle responsiveness to insulin in the neonatal rat

Peripheral muscle responsiveness to insulin was studied in neonatal rats in vivo by measuring net incorporation of radiolabeled glucose to glycogen in diaphragm. D(U-¹⁴C) glucose, 0.03 μCi/g rat pup weight, was injected i.p. with or without (control) insulin 5000 μU/g rat pup weight into pups from 86 litters of Sprague-Dawley rats as well as into 16 adult rats by the technique of Rafaelson. Diaphragms were excised after a 30-min in vivo exposure at birth, 24, 48, 72, or 168 hr of age and in the adult rats. Insulin increased net incorporation of radiolabeled glucose into diaphragm glycogen in comparison to age-matched controls (p < 0.025). The percent stimulation by insulin of labeled glucose into diaphragm glycogen was low at birth (250%) and at 24 hr (200%), but increased with advancing age and approached adult levels by 168 hr (1270%). At birth and at 24 hr, a 5-log insulin dose-response curve showed significant net incorporation only at 5000 μU insulin/g rat pup weight; by 72 hr a significant increase was noted at 50 μU insulin/g rat pup weight. Muscle glycogen concentration was high at birth ($\text{1.22 mg}\text{100 mg tissue}$), fell to 50% of the birth value from 24 through 168 hr, and could not account for the decreased insulin response noted. Decreased uptake of deoxyglucose into diaphragm in vivo paralleled the reduced net incorporation of radiolabeled glucose into diaphragm glycogen during the time period studied. The data are interpreted to indicate a blunted responsiveness of skeletal muscle to insulin during the first 48 hr in rats, which is related to decreased sensitivity of hexose transport to insulin.     

Integration of intraoral digital scans with a 3D facial scan for anterior tooth rehabilitation

This article describes a digital technique that combines intraoral digital scans with a 3-dimensional facial scan to predict the outcome of prosthodontic treatment of anterior teeth at the treatment planning phase. This approach may increase patient acceptance of the definitive treatment, as the altered facial appearance is visualized with definitive prosthodontic restorations, thereby improving communication before treatment begins.     

Advancing infection control in dental care settings: Factors associated with dentists' implementation of guidelines from the Centers for Disease Control and Prevention

Background and OverviewThe authors set out to identify factors associated with implementation by U.S. dentists of four practices first recommended in the Centers for Disease Control and Prevention's Guidelines for Infection Control in Dental Health-Care Settings—2003.MethodsIn 2008, the authors surveyed a stratified random sample of 6,825 U.S. dentists. The response rate was 49 percent. The authors gathered data regarding dentists' demographic and practice characteristics, attitudes toward infection control, sources of instruction regarding the guidelines and knowledge about the need to use sterile water for surgical procedures. Then they assessed the impact of those factors on the implementation of four recommendations: having an infection control coordinator, maintaining dental unit water quality, documenting percutaneous injuries and using safer medical devices, such as safer syringes and scalpels. The authors conducted bivariate analyses and proportional odds modeling.ResultsResponding dentists in 34 percent of practices had implemented none or one of the four recommendations, 40 percent had implemented two of the recommendations and 26 percent had implemented three or four of the recommendations. The likelihood of implementation was higher among dentists who acknowledged the importance of infection control, had practiced dentistry for less than 30 years, had received more continuing dental education credits in infection control, correctly identified more surgical procedures that require the use of sterile water, worked in larger practices and had at least three sources of instruction regarding the guidelines. Dentists with practices in the South Atlantic, Middle Atlantic or East South Central U.S. Census divisions were less likely to have complied.ConclusionsImplementation of the four recommendations varied among U.S. dentists. Strategies targeted at raising awareness of the importance of infection control, increasing continuing education requirements and developing multiple modes of instruction may increase implementation of current and future Centers for Disease Control and Prevention guidelines.The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention, Atlanta.The authors thank Jon Ruesch, who when this study was conducted was the director, Survey Center, American Dental Association, Chicago, for his effort in the collection of the data for this research project. Mr. Ruesch is now retired.     

七元瓜环对小鼠的初步安全性评价

目的:评价七元瓜环对小鼠安全药理学,为后续研究瓜环类化合物对人体的影响以及作为新型药物辅料的开发提供基础资料数据。方法:依据中药、天然药物急性毒性研究技术指导原则的有关要求和OECD新发布急性径口毒性实验方法的有关记载,采用改良寇式法,计算出七元瓜环LD_(50)值。结果:七元瓜环LD_(50)值为49.1g/Kg。结论:七元瓜环属于无毒安全级,可作为一种新型安全、低毒的超分子药物载体,应用于超分子化学领域中。     

牛鼻子引流术在严重糖尿病足感染创面中的临床应用

目的探讨牛鼻子引流术（nose ring drain，NRD）治疗严重糖尿病足感染创面的临床效果。方法回顾分析 2017 年 6 月—2019 年 6 月采用 NRD 治疗的 35 例严重糖尿病足感染创面患者临床资料。男 24 例，女 11 例；年龄 28～82 岁，平均 54.5 岁。均为 2 型糖尿病患者，糖尿病病程 3～20 年，平均 9.4 年。糖尿病足病程 4 个月～2 年，平均 1.16 年。左足 16 例，右足 19 例。根据 Wagner 分级：2 级 11 例，3 级 20 例，4 级 4 例；均为糖尿病足创面中重度感染。术后创面采用“蚕食样”持续清创至表皮再生愈合。治疗过程中分析并总结创面分泌物细菌培养类型、临床抗生素使用时间，创面愈合方式、愈合时间、截肢比例等指标。结果35 例患者均随访，随访时间 3～6 个月，平均 4.5 个月。术后创面细菌培养结果显示，金黄色葡萄球菌 5 例、铜绿假单胞菌 4 例、大肠埃希菌 5 例、阴沟肠杆菌 3 例、凝固酶阴性葡萄球菌 3 例，其他类型 15 例。临床抗生素使用时间 3～15 d，平均 9.1 d。创面自溶性愈合，无需植皮，创面愈合时间 62～82 d，平均 72.3 d；随访过程中 3 例（8.6%）患者因血糖控制不佳，感染大面积扩散导致截肢 。创面愈合患者原创面处未出现感染复发及新生溃疡。结论应用 NRD 治疗严重糖尿病足感染创面，能有效控制创面感染，促进创面再生愈合，无需植皮且操作简便。