VitC/Fe2+对细胞生长状态的影响

0 引言 正常生物体内的自由基产生和清除是处在平衡状态的,外界环境中的自由基易与体内多种物质发生化学反应,并与内源性自由基一起影响着细胞的生长、分化及死亡过程[1～4],但不同实验的结果存在一些差别,甚至矛盾的现象,如过氧化氢可刺激细胞生长或引起细胞凋亡,这提示我们对自由基作用于细胞的剂量-反应关系进行研究.     

Atypical distribution of Pneumocystis carinii infiltrates during radiation therapy

Bilateral peripheral pulmonary infiltrates caused by Pneumocystis carinii developed in a patient undergoing mediastinal irradiation after chemotherapy for Hodgkin disease. The paramediastinal part of the lung included within the treatment port remained clear during the 2 1/2 weeks of radiation therapy. The distribution of the pneumocystis infiltrates was altered by the radiation, producing a pattern that is the "radiographic negative" of typical post-radiation therapy paramediastinal fibrosis.     

An improved method of densitometry of red-free retinal nerve fibre layer photographs

The red-free negatives of 53 right eyes (30 normal eyes and 23 glaucomatous eyes) and 51 left eyes (32 normal eyes and 19 glaucomatous eyes) were analysed using two different image densitometry techniques. The first technique measured the density from rectangular sample areas, while the second measured density from sector-shaped sample areas which more closely follow the course of the nerve fibres in the retina.
Indices which measured the deviation of the data from a clinically determined normal 'gold standard' were calculated, and were used to determine the optimum sensitivity and specificity in separating normal from glaucomatous eyes.
There is a significant difference between the data from the normal and glaucomatous groups of eyes, when measured from the sector sample areas. The relative efficacy of this technique is also shown by the improved values of sensitivity (from 42%-70% to 70%-91%), although specificity remained fairly constant (from 66%-83% to 62%-88%).     

绞股蓝总苷对老龄大鼠的抗氧化作用观察

目的：观察口服绞股蓝总苷对老龄大鼠的抗氧化作用。方法：测定药后大鼠红细胞超氧化物歧化酶（ＳＯＤ）和全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）等抗氧化酶含量及肾上腺内维生素Ｃ（ＶｉｔＣ）含量。结果：绞股蓝总苷４０和２０ｍｇ／ｋｇ连续用药２０ｄ能升高大鼠红细胞ＳＯＤ和全血ＧＳＨ－Ｐｘ酶活力,且能降低大鼠肾上腺皮质中ＶｉｔＣ含量。结论：绞股蓝总苷能增强老龄大鼠机体抗氧化能力及提高肾上腺皮质的功能。     

Use of the Internet for Sexual Health Among Sexually Experienced Persons Aged 16 to 44 Years: Evidence from a Nationally Representative Survey of the British Population

BackgroundThose who go online regarding their sexual health are potential users of new Internet-based sexual health interventions. Understanding the size and characteristics of this population is important in informing intervention design and delivery.ObjectiveWe aimed to estimate the prevalence in Britain of recent use of the Internet for key sexual health reasons (for chlamydia testing, human immunodeficiency virus [HIV] testing, sexually transmitted infection [STI] treatment, condoms/contraceptives, and help/advice with one’s sex life) and to identify associated sociodemographic and behavioral factors.MethodsComplex survey analysis of data from 8926 sexually experienced persons aged 16-44 years in a 2010-2012 probability survey of Britain’s resident population. Prevalence of recent (past year) use of Internet sources for key sexual health reasons was estimated. Factors associated with use of information/support websites were identified using logistic regression to calculate age-adjusted odds ratios (AORs).ResultsRecent Internet use for chlamydia/HIV testing or STI treatment (combined) was very low (men: 0.31%; women: 0.16%), whereas 2.35% of men and 0.51% of women reported obtaining condoms/contraceptives online. Additionally, 4.49% of men and 4.57% of women reported recent use of information/support websites for advice/help with their sex lives. Prevalence declined with age (men 16-24 years: 7.7%; 35-44 years: 1.84%, P<.001; women 16-24 years: 7.8%; 35-44 years: 1.84%, P<.001). Use of information/support websites was strongly associated with men’s higher socioeconomic status (managerial/professional vs semiroutine/routine: AOR 1.93, 95% CI 1.27-2.93, P<.001). Despite no overall association with area-level deprivation, those in densely populated urban areas were more likely to report use of information/support websites than those living in rural areas (men: AOR 3.38, 95% CI 1.68-6.77, P<.001; women: AOR 2.51, 95% CI 1.34-4.70, P<.001). No statistically significant association was observed with number of sex partners reported after age adjustment, but use was more common among men reporting same-sex partners (last 5 years: AOR 2.44, 95% CI 1.27-4.70), women reporting sex with multiple partners without condoms (last year: AOR 1.90, 95% CI 1.11-3.26), and, among both sexes, reporting seeking sex online (last year, men: AOR 1.80, 95% CI 1.16-2.79; women: AOR 3.00, 95% CI 1.76-5.13). No association was observed with reporting STI diagnosis/es (last 5 years) or (after age adjustment) recent use of any STI service or non-Internet sexual health seeking.ConclusionsA minority in Britain used the Internet for the sexual health reasons examined. Use of information/support websites was reported by those at greater STI risk, including younger people, indicating that demand for online STI services, and Internet-based sexual health interventions in general, may increase over time in this and subsequent cohorts. However, the impact on health inequalities needs addressing during design and evaluation of online sexual health interventions so that they maximize public health benefit.     

HPLC法测定冬凌草萜含片中冬凌草甲素的含量

目的：对冬凌草萜含片中的冬凌草甲素进行含量测定。方法：采用ＨＰＬＣ法,以Ｃ１８－ＯＤＳ为色谱柱,甲醇－水（５５：４５）为流动相,检测波长为２４２ｍｍ。结果：回收率为９８．２３％,ＲＳＤ为２．１２％。结论：该方法简便、可靠,适合冬凌草及其制剂的质量控制。     

Pulmonary angiography with iopamidol: patient comfort, image quality, and hemodynamics

The choice of a contrast agent for pulmonary angiography has important implications for patient comfort, image quality, and perhaps the safety of the procedure, particularly for "high-risk" patients. In a prospective study the nonionic, low-osmolality agent iopamidol eliminated the problem of image degradation due to coughing, and patients showed excellent tolerance for it. However, pressure measurements obtained within 3-5 minutes of injection of iopamidol and diatrizoate sodium meglumine 76% showed no significant difference in the hemodynamic effects of the two contrast agents, either for normotensive or for pulmonary hypertensive patients. Contrary to a common presumption, pulmonary hypertension by itself did not appear to increase the risk of pulmonary angiography. The theoretic presumption of greater hemodynamic stability with low-osmolality contrast agents was not clinically evident in this trial with iopamidol. At present, enhanced patient comfort and improved image quality remain the only confirmed bases for choosing this contrast agent for pulmonary angiography.     

Telementoringineducationoflaparoscopicsurgeons:Anemergingtechnology

Laparoscopy, minimally invasive and minimal access surgery with more surgeons performing these ad-vanced procedures. We highlight in the review several key emerging technologies such as the telementor-ing and virtual reality simulators, that provide a solid ground for delivering surgical education to rural area and allow young surgeons a safety net and confidence while operating on a newly learned technique.     

Peptide-induced stabilization and intracellular localization of empty HLA class I complexes.

The human cell line T2 has been reported to be class I assembly deficient, and accordingly expresses reduced amounts of HLA-A2 and no HLA-B5 at the cell surface. By immunoblotting we observe the steady-state class I heavy chain levels of T2 to be near normal when compared with the identical class I alleles of the wild-type cell line T1. In pulse chase experiments, formation of heavy chain beta 2-microglobulin complexes is observed for both HLA-A2 and HLA-B5. Culture at reduced temperatures (26 or 20 degrees C) does not increase the amount of class I molecules transported, unlike what has been reported for the class I assembly-deficient mouse mutant cell line RMA-S. The HLA-B5 and the HLA-A2 complexes formed by T2 are thermolabile in cell lysates, albeit to different degrees. The thermolability of HLA-B5 can be overcome by addition of HLA-B5-presentable peptides, obtained by trifluoroacetic acid extraction from an HLA-B5-positive cell line, underlining the necessity of peptide for class I stability and indicating that T2-derived class I complexes are devoid of peptide. Cytoplast fusion of T2 cells with RMA-S cells shows the defect in class I assembly of RMA-S to be similar to that of T2. Localization of class I molecules observed by immuno-electron microscopy reveals the accumulation in the T2 cell line of both HLA-B5 and HLA-A2 in the endoplasmic reticulum (ER). Class I molecules are present in all the cisternae of the Golgi complex of T2, but the ratio of HLA-A and -B locus products in the Golgi area differs significantly from that at the cell surface. We conclude that the requirement for peptide in transport of class I molecules manifests itself at a stage beyond the ER, most likely the Golgi area.