广州市大学生尝试自杀现况及其影响因素分析

目的了解广州市大学生尝试自杀现状及其影响因素，为高校健康教育提供理论依据。方法采用整群随机抽样方法，用自编调查表对大学生进行问卷调查，在此基础上结合专题小组讨论的定性研究方法进行分析。结果大学生近1a内尝试自杀报告率为6．0％，不同性别、学校、专业的学生尝试自杀报告率差异无统计学意义（P〉0．05）；城镇学生尝试自杀报告率为6．6％，高于农村学生的4．2％（x^2=4．71，P=0．032）。对自杀行为的态度、朋友和家人有过自杀行为、消极应对、负性生活事件等是尝试自杀的危险因素，获得社会支持是尝试自杀的保护因素。定性访谈发现，学校几乎没有开展过自杀行为的健康教育活动，绝大部分学生对自杀行为持中立态度。结论加强健康教育、消除危险因素、提高保护因素可以最大限度地预防自杀.     

Physical inactivity, excess adiposity and premature mortality

The purpose of this report is to review the evidence that physical inactivity and excess adiposity are related to an increased risk of all‐cause mortality, and to better identify the independent contributions of each to all‐cause mortality rates. A variance‐based method of meta‐analysis was used to summarize the relationships from available studies. The summary relative risk of all‐cause mortality for physical activity from the 55 analyses (31 studies) that included an index of adiposity as a covariate was 0.80 [95% confidence interval (CI) 0.78–0.82], whereas it was 0.82 [95% CI 0.80–0.84] for the 44 analyses (26 studies) that did not include an index of adiposity. Thus, physically active individuals have a lower risk of mortality by comparison to physically inactive peers, independent of level of adiposity. The summary relative risk of all‐cause mortality for an elevated body mass index (BMI) from the 25 analyses (13 studies) that included physical activity as a covariate was 1.23 [95% CI 1.18–1.29], and it was 1.24 [95% CI 1.21–1.28] for the 81 analyses (36 studies) that did not include physical activity as a covariate. Studies that used a measure of adiposity other than the BMI show similar relationships with mortality, and stratified analyses indicate that both physical inactivity and adiposity are important determinants of mortality risk.     

老年人前瞻性记忆损害的研究

目的 了解健康老年人前瞻性记忆改变的情况,初步探讨老年人基于事件的前瞻性记忆(EBPM)和基于时间的前瞻性记忆(TBPM)损害程度的区别.方法 建立前瞻性记忆的神经心理学测验方法,测试教育程度相匹配的40名健康老年人和40名健康成年人的EBPM和TBPM.结果 与成年组[EBPM(6.25±1.60)分;TBPM(5.38±0.87)分]相比,老年组的EBPM[(2.50±0.85)分和TBPM(4.93±1.07)分]均较成年组差(P＜0.01,P＜0.05),而EBPM损伤指数的差异亦有统计学意义(P＜0.01).老年组前瞻性记忆的EBPM和TBPM存在双分离.结论 老年人存在前瞻性记忆的损害,EBPM损害较TBPM损害更为显著.EBPM和TBPM的双分离表明其可能有不同的神经机制,推测额叶可能特异性地参与了EBPM.     

Signal-to-noise ratio effects in quantitative cerebral perfusion using dynamic susceptibility contrast agents.

Theoretical and simulation evidence is presented in support of the idea that the optimal manner of determining blood flow from MR perfusion studies is not necessarily obtained by setting experimental conditions to maximize either the arterial input or the measured tissue concentration level for a particular echo time (TE). The noise power in the contrast concentration curve is associated with its peak because of the nonlinear relationship between the contrast concentration and MR signal intensity curves. The optimum signal-to-noise ratio (SNR), SNR(C), for a particular contrast concentration curve can be obtained when the experimental concentration level and TE are adjusted to produce an MR intensity curve whose signal loss is 63% of the precontrast MR signal intensity. It is demonstrated that the stability of the singular valued decomposition (SVD) deconvolution approach to determine blood flow parameters is increased when the tissue curve maximum signal loss is in the range of 40-80%. The accuracy and stability of the SVD-determined blood flow parameters are affected by deviations from these optimum conditions in a manner that depends on the mean transit time (MTT) associated with the residue function. It is recommended that the experimental TE value be set so that neither the tissue nor the arterial curves are placed a region of rapidly deteriorating SNR(C).     

心理干预对错[牙合]畸形治疗中合作行为及结果的影响

目的：观察心理干预对错[牙合]畸形患者正畸治疗中合作行为及结果的影响。方法：对门诊口腔科60例青少年[牙合]畸形患者随机分为干预组和对照组各30例。两组均由从事正畸工作5年以上的主治医师采用标准方丝弓技术进行矫正治疗，干预组同时实施心理干预等心理治疗。将两组治疗中的合作行为和结果进行比较分析。结果：心理干预组自律性、主动性、自觉性、矫治时间、满意度等均明显优于对照组，差异有显著性（P〈0．01）。结论：心理干预对青少年正畸患者治疗中合作行为和结果有明显影响，通过心理干预能提高矫治的效果，保证治疗的顺利完成。     

Diet and premenopausal bilateral breast cancer: A case-control study

We investigated associations between diet and premenopausal bilateral breast cancer in a familial matched case-control study. We studied 140 cases from population-based registries in Los Angeles County (California) and Connecticut, and from the major hospitals in the southern parts of the Province of Quebec. Unaffected sisters of the cases served as matched controls (222 total). Dietary intake were assessed with a food frequency questionnaire. Total fat, monounsaturated fat, polyunsaturated fat, oleic acid, and linoleic acid intake was inversely associated with premenopausal bilateral breast cancer risk. Consumption of carbohydrates (and sweetened beverages) was associated with an increased risk. We observed no associations for dietary fiber, antioxidants, or major food groupings, but we did observe inverse associations for intake of low fat dairy products and tofu. These findings suggest that monounsaturated and polyunsaturated fats, as well as soy foods, might reduce the risk of premenopausal bilateral breast cancer.     

Designed polyanionic coiled-coil proteins: acceleration of heparin cofactor II inhibition of thrombin

Novel polyanionic proteins were designed to increase the rate of heparin cofactor II (HC) inhibition of α-thrombin, an essential protease in the coagulation cascade. Two α-helical coiled-coil proteins, a 62-residue dimer containing 8 Glu residues (E8C) and a 104-residue dimer containing 14 Glu residues (E14C), plus two 31-residue control peptides containing 8 Glu residues each (E8A and E8B), were chemically synthesized, structurally characterized and enzymatically assayed. Circular dichroic spectrophotometry indicated that both E8C and E14C formed stable two-chain α-helical coiled coils at pH 7 and 25 °C. The control peptides were only partially α-helical. E14C remained folded at 90 °C but E8C was half unfolded at 49 °C. Coiled-coil proteins E8C and E14C maximally accelerated by 35- and 33-fold, respectively, the rate of HC inhibition of α-thrombin. None of these compounds accelerated antithrombin inhibition of α-thrombin, and neither control peptide accelerated HC inhibition of α-thrombin. Acceleration of the HC inhibition of α-thrombin showed bimodal dependence on the concentration of the polyanionic protein, which is consistent with formation of a HC-coiled-coil-thrombin ternary complex. The results suggest that antithrombotic polyanionic α-helical coiled-coil proteins can be designed and synthesized and that the occurrence of secondary structure can be correlated with biologcal activity. © Munksgaard 1995.     

173例支气管哮喘特异性脱敏治疗的进一步评价

对173例支气管哮喘特异性脱敏治疗的疗效及影响疗效的因素进行了分析。结果表明:显效为30.6%(53/173).有效为56.1%(97/173),无效为13.3%(23/173)。影响疗效的因素与病情的程度有关,而与年龄、病程、皮试阳性反应强弱及脱敏治疗前4个疗程内是否应用曲安缩松等无关。并对特异性脱敏治疗支气管哮喘的优缺点进行讨论。     

先天性心脏病与柯萨奇病毒B3,B4感染的关系

采用配对病例对照研究，探讨先心病与柯萨奇病毒B3、B4感染的关系，结果显示：病例组与对照组患儿CVB3、CVB4．IgG抗体阳性率分别为59．3％、54．3％和53．6％、45．7％，差异天显著性（P值均＞0．05）；经单因素和多因素回归分析均未发现CVB3、CVB4感染与先心病有病因学联系（P＞0．05）