偏心圆剥离法在隆乳术中的应用

以往以乳头为圆心的同心圆剥离法常形成假体的移位，使假体的体表轮廓与前方的自然乳房分离，产生“双重乳房”现象。在研究了女性不同体位下不同的乳房形态及总结了以前的经验后，提出了偏心圆剥离的概念。偏心圆手术设计方法：以乳头为圆心，按其内侧、下侧为直径３／５的比例，以外侧、上侧为直径２／５的比例，形成一偏心圆的剥离范围。偏心圆的直径因考虑到假体的不同形态、大小及底面直径，以经中心假体纵截面的周长的１／２再放大２ｃｍ，作为剥离范围的直径。自１９９１年１０月以来已应用了１７６例，无一术后移位现象，也没有固较多地剥离胸大肌内、下侧止点纤维而影响上肢活动。自然乳房并不是静态的圆锥形或半球形，它具有伸缩的组织学特点，又有随体位变动而变化的特点。用偏心圆法剥离，可使置入的假体与前方的自然乳房融为一体，消除“双重乳房”现象，而成为“真实”的乳房。同时也应积极寻找一种与身体组织相容性好的，弹性、比重与女性乳腺较为一致的，假体容量相对恒定的生物性材料。这样隆乳术才可以更广泛地开展。     

血脂测定结果的临床可接受性分析

目的:通过对不同检测系统血脂测定结果的偏倚评估,分析各系统间结果的可比性和临床可接受性。方法:参照CLSI文件相关要求,以可溯源的检测系统为目标检测系统,测定总胆固醇(TCH)、甘油三酯(TG)、载脂蛋白A1(APOA1)、载脂蛋白B(APOB)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C),对本院3个不同检测系统进行朗道质控物(水平2和水平3)各测定21次和测定新鲜血清标本40份。结果:朗道质控物和新鲜血清标本TCH、TG、APOA1、APOB、HDL-C、LDL-C浓度在系统间的差异均有显著性(P<0.05)。除LDL-C在各检测系统间的相关系数为0.7859~0.9259之间外,其他项目各系统间的相关系数均大于0.975。各检测系统测定TCH、TG的不精密度CV均小于5%,其他项目的不精密度CV均小于10%;以可溯源检测系统1为目标检测系统,临床可接受性能评价:TCH、LDL-C在检测系统2和检测系统3超出临床接受范围,HDL-C在检测系统2超出临床接受范围,其他项目临床均可接受。结论:3个不同检测系统测定TG、APOA1、APOB结果具有可比性;测定HDL-C结果具有部分可比性,TCH、LDL-C结果不具有可比性,需采取整改措施。     

遗传因素在乳头状甲状腺癌发生中的作用

目的探讨遗传因素在乳头状甲状腺癌(PTC)发生中的作用.方法采用以医院为基础的病例对照家系研究设计,采用Greenwood-Yule法和Haldane-Smith法,对172例PTC先证者及18例患PTC的亲属进行出生顺序分析.比较先证者一、二级亲属和一般人群的患病率,并进行零截尾负二项分布拟合检验,分析PTC是否具有家族聚集性.结果Greenwood-Yule法的分析结果显示,PTC出生顺序的实际分布与期望分布相近,各出生顺序的实际数与期望数的比值在1范围波动,表明PTC与出生顺序无关.Haldane-Smith法计算得C=|∑6A实际值-∑6A理伦值|/√∑V6A=0.567,P＞0.05,实际值与期望值的差异无统计学意义,亦表明PTC与出生顺序无关.PTC患者的一、二级亲属和人群患病率分别为1.08%、0.42%和0.09%,其中,一、二级亲属患病率的差异有统计学意义(x2=4.07,P=0.044),二级亲属与人群患病率的差异亦有统计学意义(Fisher P=0.046),PTC患病率存在一级亲属＞二级亲属＞一般人群的规律.零截尾负二项分布拟合检验结果表明,PTC在家系中的分布符合零截尾负二项分布(x2=0.13,P＞0.05),PTC的发生存在家族聚集性.结论遗传因素可能是PTC的主要危险因素,PTC可能是一种多因子遗传病.     

Caregiver recall in childhood vaccination surveys: Systematic review of recall quality and use in low- and middle-income settings

IntroductionHigh population coverage is key to the impact of vaccines. However, vaccine coverage estimates in low- and middle-income countries (LMICs) have repeatedly been shown to be of poor quality. LMICs often rely on ‘caregiver recall’ of vaccination, the validity and collection method of which remains uncertain. We aimed to critique the quality of caregiver recall and make recommendations for its collection and use.MethodsWe performed a systematic review for methods assessing childhood vaccination coverage in LMICs. We searched Medline using variations of the key terms: (child) AND (vaccinat¹) AND (survey OR recall OR coverage) AND (reliab¹ OR valid¹). We selected articles assessing the quality of recall in LMICs and extracted reported validity, reliability and completeness. We synthesised recommendations on collecting, analysing and presenting caregiver recall for varying resource availabilities.ResultsOf 1268 articles, 134 full texts were screened and eight were included for review. There was heterogeneity in study designs, ways of incorporating recall data and outcomes measured. Sensitivity of recall was 41–98%; specificity was 12–80%. There was a dearth of reliability measures and no consistent method for dealing with data incompleteness.ConclusionThere are quality concerns with caregiver recall and difficulty in assessing it given the lack of a ‘gold standard’ for vaccine status. To improve coverage estimates and the impact of vaccines, caregiver recall should be used. Other recommendations include: recall is included for those presenting vaccine records; missing data is imputed; recall and record quality are assessed in a sub-sample; and sensitivity analyses are performed.     

Alcances de la aleatorización mendeliana para el control de confusores no observables en epidemiología

The Mendelian randomization is an epidemiologic method proposed to control for spurious associations in observational studies. These associations are commonly caused by confusion derived from social, environmental, and behavioral factors, which can be difficult to measure. Mendelian randomization is based on the selection of genetic variants that are used as instrumental variables that influence exposure patterns or are associated with an intermediate phenotype of the disease. The present work aims to discuss how to select the appropriate genetic variants as instrumental variables and to present methodological tools to deal with the limitations of this epidemiological method. The use of instrumental variables for modifiable exposures has the potential to mitigate the effects of common limitations, such as confusion, when robust genetic variants are chosen as instrumental variables.