Infant and Neonatal Mortality for Primary Cesarean and Vaginal Births to Women with “No Indicated Risk,” United States, 1998–2001 Birth Cohorts

ABSTRACT: Background: The percentage of United States’ births delivered by cesarean section has increased rapidly in recent years, even for women considered to be at low risk for a cesarean section. The purpose of this paper is to examine infant and neonatal mortality risks associated with primary cesarean section compared with vaginal delivery for singleton full‐term (37–41 weeks’ gestation) women with no indicated medical risks or complications. Methods: National linked birth and infant death data for the 1998–2001 birth cohorts (5,762,037 live births and 11,897 infant deaths) were analyzed to assess the risk of infant and neonatal mortality for women with no indicated risk by method of delivery and cause of death. Multivariable logistic regression was used to model neonatal survival probabilities as a function of delivery method, and sociodemographic and medical risk factors. Results: Neonatal mortality rates were higher among infants delivered by cesarean section (1.77 per 1,000 live births) than for those delivered vaginally (0.62). The magnitude of this difference was reduced only moderately on statistical adjustment for demographic and medical factors, and when deaths due to congenital malformations and events with Apgar scores less than 4 were excluded. The cesarean/vaginal mortality differential was widespread, and not confined to a few causes of death. Conclusions: Understanding the causes of these differentials is important, given the rapid growth in the number of primary cesareans without a reported medical indication. (BIRTH 33:3 September 2006)     

常温与低温体外循环心脏直视手术对细胞因子及补体的影响

目的探讨常温及低温体外循环心脏直视手术对细胞因子及补体的影响。方法选择先天性和风湿性心脏病患者40例,随机分为常温组及低温组各20例,分别于术晨、体外循环结束时及术后1、4、7、14 d抽取患者静脉血标本,测定血浆TNF、IL-2、C3、C4值。结果两组术前各项检查指标无显著差异。(1)两组术后1~4 d的IL-2水平较术前显著下降,至术后7 d恢复正常。体外循环结束至术后4 d,低温组IL-2显著低于常温组。(2)体外循环结束时以及术后1、4、7 d,常温组TNF水平显著低于低温组。两组体外循环结束时及术后1、4 d均高于术前,常温组至术后7 d、低温组术后14 d恢复正常。(3)体外循环结束时及术后1、7 d,常温组C3水平高于低温组,术后4 d两组无差别;常温组及低温组于体外循环结束时、术后1、4 d均低于术前,至术后7 d常温组恢复正常,低温组至术后14 d恢复至术前水平。(4)两组体外循环结束时及术后1、4 d C4水平均低于术前。体外循环结束时、术后1 d,常温组C4水平高于低温组。结论常温体外循环心脏直视手术对细胞因子及补体的影响显著轻于低温组,因而对术后机体的恢复优于低温方法。     

3种常用低温灭菌方法研究现状

阐述了环氧乙烷低温灭菌法、低温蒸汽甲醛灭菌法、过氧化氢等离子体灭菌法的灭菌机制、主要特点及应用范围。     

Primary cemented total hip arthroplasty—an Indian experience

We report outcome of 9-year follow-up of 50 Charnley cemented primary arthroplasties in 47 patients performed between 1996 and 1999. The minimum follow-up period was 5 years with a mean of 7 years. All hip joints were thoroughly assessed preoperatively to document patients’ functional level and Harris hip score was calculated. All the patients were disabled because of pain in hip and 45 (90%) had used walking aids. At follow-up all patients were living. The radiographs of all patients were available for the entire follow-up period. Of the 50 operated hips, only 2 patients (4%) complained of pain while all the rest were free of pain. Postoperatively only 10 (20%) patients used support for walking. At follow-up none of the hips were revised. Two patients (4%) had dislocation in postoperative period in which reduction was done under anesthesia. In one patient (2%) prosthesis and cement was removed because of deep infection. In two patients (4%) radiolucent clear zone was seen at bone cement interface on acetabular side and three (6%) patients had it on femoral component. None of the patients developed deep vein thrombosis or heterotopic bone. In postoperative period the Harris hip score was calculated in each case and compared with the preoperative score to evaluate the outcome. Significant improvement was found in Harris hip score after surgery.     

长链核酸扩增技术评价病毒灭活效果的研究

目的:探讨用长链核酸扩增技术评价病毒灭活效果的可行性.方法:针对伪狂犬病毒(pseudorabies virus,PRV)糖蛋白gD基因前后的保守区设计预计产物长短不一的5对引物,用半巢式PCR技术扩增经低pH法(4.0±0.1)、巴氏消毒法[(60±1.0)℃]和s/D法(有机溶剂/洗涤荆)处理后的PRV核酸,同时以细胞感染法做平行对照.结果:低pH对PRV核酸有破坏作用,处理时间越长,核酸损伤程度越明显,处理60 min时,6.62 lgTCID50的PRV完全被灭活.5条不同长度PCR扩增产物中,只有3.9 kb的长片段检出与细胞培养结果一致.7.25 lgTCID50的PRV经(60±1.0)℃处理20 min后即被完全灭活,7.13 lgTCID50的PRV经s/D法处理1 h后被完全灭活,但各长度核酸片段扩增均为阳性,与细胞感染试验结果不符.结论:低pH对PRV核酸的损伤程度随处理时间的延长而增加;用长链PCR(3.9 kb)技术来评价经低pH法灭活病毒的效果是可行的,而该法不适合评价巴氏消毒法和S/D法灭活病毒的效果.     

高脂血症对血浆t-PA和PAI-1活性的影响

目的 探讨高脂血症患者的纤溶系统的变化。方法 选取正常人及高脂血症者，测定其血脂、血浆t—PA和PAI-1活性。结果 高脂血症组比正常人血浆t—PA活性下降，而PAI-1的活性有升高；在TG及LDL-C升高者，其血浆t—PA活性比正常人血浆t—PA活性降低，而血浆PAI-1活性比正常人升高；单纯TC升高者血浆PAI-1活性接近正常人组，而血浆t—PA活性比正常人组明显降低。结论 高脂血症对纤溶系统有一定的影响，其中甘油三酯和LDL-C对纤溶系统的影响更明显，而胆固醇对纤溶系统也有一定的影响。     

低氧分压对大鼠勃起功能的影响

目的探讨低氧分压对大鼠勃起功能障碍（ED）的影响。方法48只成年白色雄性SD大鼠随机分为对照组和实验组，每组按照实验时间（2周、6周、10周）分为3个亚组，每个亚组8只。实验组置于密闭低氧舱中饲养，对照组在正常环境中饲养，其他条件相同。分别观察其勃起功能，采用免疫组化SP法检测神经源性一氧化氮合成酶（nNOS）阳性神经纤维的数量、内皮源性一氧化氮合成酶（eNOS）的表达。结果实验组与对照组比较：（1）大鼠勃起次数明显降低（P〈0．001）；（2）nNOS阳性神经纤维数量、eNOS蛋白的表达均有显著性差异（P〈0．01）。实验组间比较：勃起次数6周组明显低于2周组，10周组稍高于6周组；nNOS阳性神经纤维数量有显著性差异（P〈0．01）；eNOS的表达6周组最低，10周组有所回升。结论低氧分压致大鼠勃起功能受损和nNOS、eNOS的表达下降。nNOS染色阳性神经纤维数量的减少、eNOS表达的下降，可能是低氧分压环境中大鼠ED发生的原因之一。     

Users' subjective evaluation of electronic vision enhancement systems

The aims of this study were (1) to elicit the users' responses to four electronic head-mounted devices (Jordy, Flipperport, Maxport and NuVision) and (2) to correlate users' opinion with performance. Ten patients with early onset macular disease (EOMD) and 10 with age-related macular disease (AMD) used these electronic vision enhancement systems (EVESs) for a variety of visual tasks. A questionnaire designed in-house and a modified VF-14 were used to evaluate the responses. Following initial experience of the devices in the laboratory, every patient took home two of the four devices for 1 week each. Responses were re-evaluated after this period of home loan. No single EVES stood out as the strong preference for all aspects evaluated. In the laboratory-based appraisal, Flipperport typically received the best overall ratings and highest score for image quality and ability to magnify, but after home loan there was no significant difference between devices. Comfort of device, although important, was not predictive of rating once magnification had been taken into account. For actual performance, a threshold effect was seen whereby ratings increased as reading speed improved up to 60 words per minute. Newly diagnosed patients responded most positively to EVESs, but otherwise users' opinion could not be predicted by age, gender, diagnosis or previous CCTV experience. User feedback is essential in our quest to understand the benefits and shortcoming of EVESs. Such information should help guide both prescribing and future development of low vision devices.