一氧化氮对人肝癌细胞SMMC-7721辐射敏感性的增强效应

目的:观察一氧化氮对肿瘤细胞SMMC-7721辐射敏感性的作用效果。方法:实验于2005-06/09在兰州大学生命科学学院和中科院近代物理研究辐射医学实验室进行。处于对数生长期的肝癌细胞SMMC-7721,在用X射线照射前4h,换入含有0.1mmol/L硝普钠(一氧化氮的前体)的培养液,与对照组(不加硝普钠)一起,在200cGy/min的剂量率下,分别照射0,1,2,4,6,8Gy,换为正常培养液培养。用集落形成法计算细胞的存活率,用吖啶橙/溴乙啶双染法检测细胞的死亡情况,用流式细胞仪检测细胞周期。结果:①存活曲线细胞存活率随照射剂量增加而减少,硝普钠组细胞的克隆形成率低于对照组(2Gy时,P<0.01)。②细胞死亡百分率(坏死细胞与凋亡细胞总数/总细胞数):与照射剂量呈正相关,硝普钠组高于对照组(P<0.05)。对照组从(9.95±3.53)%(0Gy)逐渐升至(58.74±3.46)%(6Gy),而硝普钠组则从(18.53±12.02)%(0Gy)迅速升至(61.57±9.53)%(2Gy)。③细胞周期检测结果:对照组细胞经过X射线照射后,出现了G2/M期阻滞[从0Gy时(12.50±5.76)%逐渐增加到8Gy(40.36±2.74)%],而硝普钠组细胞在低剂量时主要表现为G0/G1期阻滞[0Gy:(16.06±7.19)%;2Gy:(17.93±0.92)%],而G2/M期阻滞仅在高剂量时明显[8Gy时为(50.10±3.93)%,P<0.05]。结论:经硝普钠产生的一氧化氮,通过与X射线协同作用,减少了肝癌细胞SMMC-7721的细胞存活率,促进细胞死亡,阻止细胞被阻滞至G2/M期,是一种有效的辐射增敏剂。     

针刺足三里和悬钟治疗缺血性脑卒中

目的:观察针刺足三里、悬钟2穴对缺血性脑卒中脑血管功能的影响,分析其可能的作用机制,并对临床疗效做出评价。方法:选择2004-11/2006-05湖北中医药高等专科学校附属古城医院针灸科、荆州市第五人民医院中医康复科、荆州市第三人民医院中医科3单位缺血性脑卒中患者合适病例160例,采用查随机数字表的方法,将其随机分为对照组和针刺组,各80例。对照组采用现代医学常规干预方法进行治疗:卧床,保持呼吸道通畅,预防感染,控制颅内压、血压,维持水电解质平衡。针刺组在此基础上加针刺足三里、悬钟2穴,采用慢速捻转进针法针刺,留针20～30min,每隔5min行针1次。1次/d。两组患者治疗30d。并以经颅多普勒检测观察缺血性脑卒中患者治疗前后脑血管舒缩反应能力、脑血流自动调节功能、大脑半球侧枝循环代偿功能的变化,同时以治疗前后神经功能缺损程度为指标评价其临床疗效。结果:160例病例全部进入结果分析。①针刺组与治疗前相比,脑血管舒缩反应能力明显加强,差异有显著性意义(t=2.97,P<0.05),且优于对照组(t=2.45,P<0.05)。②针刺组与治疗前相比,脑血流自动调节能力明显改善,差异有非常显著性意义(t=8.01,P<0.01),且优于对照组(t=7.67,P<0.05)。③针刺组与治疗前相比,大脑半球侧枝循环代偿功能得到加强,差异有显著性意义(t=3.15,P<0.05),且优于对照组(t=5.16,P<0.05)。④针刺组与治疗前相比,神经功能缺损积分明显降低,差异有非常显著性意义(t=4.83,P<0.01),且优于对照组(t=5.43,P<0.05)。结论:针刺足三里、悬钟2穴对缺血性脑卒中患者脑血管舒缩反应能力、脑血流自动调节功能、大脑半球侧枝循环代偿功能有明显改善作用,并能促进神经功能的恢复。     

藻酸钠复合自体软骨细胞修复猪关节软骨缺损的近期效果

目的:采用藻酸钠自体软骨细胞混合物修复猪的关节软骨缺损,观察近期成骨效应。方法:实验于2004-03/2005-04在中山大学附属第二医院实验中心完成。3个月龄的小型猪8只,取其关节软骨进行细胞原代培养,获取原代细胞后,分别进行免疫组织化学法检测细胞Ⅱ型胶原表达。然后对8只小型猪的32个关节进行动物关节缺损的模型建立,每个关节共造3个人工缺损,选择关节左右随机对照。将已经培养好的软骨细胞与已经配制好并消毒的藻酸钠混合,移植到猪的关节软骨缺损处。每只猪关节内注射3个实验点,1个用藻酸钠/细胞混合液为实验组,1个单纯支架材料为单纯材料对照组,1个缺损做空白对照组,模型中缺损区均为关节负重区,胶原纤维绿色(亮绿复染)。修复所用细胞为自体软骨体外培养后,进行移植修复,采用3代体外培养软骨细胞,均匀混和藻酸钠后,行自体移植。8周后取实验关节进行大体观察、苏木精-伊红染色、Masson染色、免疫组织化学法染色观察及O’driscoll组织学评分。结果:纳入小型猪8只,除其中1例因手术切断伸直肌腱而使猪关节活动障碍,其余均未见手术后关节活动障碍,所有手术无术后感染,无关节内感染,无动物死亡。移植的软骨细胞在藻酸钠载体中生长良好,形成透明软骨。根据O’driscoll组织学评分标准,实验组32个猪关节缺损修复的组织学评分为(20.25±1.64)分,高于单纯材料对照组的(7.46±1.29)分及空白对照组的(6.00±2.09)分。免疫组织化学染色可见修复软骨以表达Ⅱ型胶原为主,无Ⅰ型胶原。结论:藻酸钠复合自体软骨细胞作为软骨移植的替代物是可行的,远期效果还有待进一步研究。     

Comparison of structured observation and pictorial 24 h recall of household activities to measure the prevalence of handwashing with soap in the community

This study compared structured observation with a 24 h pictorial recall of household activities (‘sticker diary’) to measure the prevalence of handwashing with soap (HWWS) in the community. The study was done within a cluster-randomised trial evaluating a handwashing promotion programme in Bihar, India. HWWS at key occasions in mothers and school children was measured by structured observation in 299 households from 32 villages. Sticker diaries recalling common activities, including personal hygiene, were used to measure HWWS in 299 households from a further 20 villages. Sticker diary HWWS prevalence estimates were about 13% points higher than structured observation estimates, but the differences varied by the type of handwashing occasion. This study confirms structured observation as the method of choice for the study of handwashing behaviours. The sticker diary method may be useful in large-scale surveys. Sticker diaries may overestimate HWWS at important occasions, but probably less so than conventional questionnaire tools.     

Deficiency of platelet membrane glycoprotein Ia associated with a decreased platelet adhesion to subendothelium: a defect in platelet spreading

A bleeding disorder with absent collagen-induced platelet aggregation and adhesion has been described in a patient whose platelets failed to express surface glycoprotein Ia. We studied the interaction of her platelets with subendothelium in an annular perfusion chamber and the interaction with purified human collagen type III in a rectangular perfusion system under flow conditions. Platelet adherence was almost completely absent both at low and high shear rates. The few platelets which adhered remained in the contact stage without subsequent spreading and aggregate formation. Addition of a monoclonal antibody, which was directed against the von Willebrand moiety of FVIII-VWF, to the blood, completely abolished platelet adherence at high shear rates and had a partial effect at low shear rates. These data indicate that von Willebrand factor plays a role in the initial attachment (contact stage) of platelets to subendothelium. We conclude that the bleeding disorder and excessively prolonged bleeding time in our patient are caused by a new specific defect of the platelet-vessel wall interaction.     

When to image neurologically normal children with headaches: development of a decision rule

Aims: The aim of this study was to develop and refine a decision rule on when to undertake brain imaging (BI) in neurologically normal children with headaches. Methods: From the literature and a questionnaire study, a list of red flags (RFs) was drawn‐up. During the prospective 4‐year period, consecutive children with headache were classified according to RFs and the headache diagnosis. Result: Three of 709 (0.4%) neurologically normal children had significant brain abnormalities. BI was carried out in 389 of 498 (78%) children with RFs. Significant abnormalities were found in three of 389 children (0.8%), all had unclassified headache (UH). BI was not arranged for the 211 children with no RFs. None of these developed RFs or abnormal signs on follow‐up for a mean of 13 months. Conclusion: In addition to BI for those with neurological signs, we think BI should be considered for neurologically normal patients with UH and RFs. This would have saved imaging children needlessly: only 101 of 709 (14%) would have had scans arranged, instead of 389 of 709.     

Sex differences in the relative contribution of social and clinical factors to the Health Utilities Index Mark 2 measure of health-related quality of life in older home care clients

Background  

The heterogeneity evident among home care clients highlights the need for greater understanding of the clinical and social determinants of multi-dimensional health-related quality of life (HRQL) indices and of potential sex-differences in these determinants. We examined the relative contribution of social and clinical factors to HRQL among older home care clients and explored whether any of the observed associations varied by sex.