青少年和成年人无症状阻生智齿干预措施的疗效评价

目的评价在青少年和成人中拔除与保留无症状阻生智齿的效果.方法计算机检索Cochrane口腔健康组资料库(至2004年8月4日),Cochrane中心临床对照试验资料库(CENTRAL),Ovid-MEDLINE(1966～2004年8月4日),PubMed(1966～2004年8月4日)和EMBASE(1974～2004年8月4日).检索无语种限制.同时对主要相关杂志进行手检,并尽力获取正在进行和未发表的研究.纳入比较预防性拔除与保留阻生智齿效果的全部随机对照或临床对照研究.由3位作者分别独立评价所检出文献的相关性、真实性并提取数据,如有不确定性,联系作者以获取关于随机和失访的更多信息.对所有试验均进行了质量评价.结果共纳入3个研究,其中2个已完成的随机对照试验评价了青少年预防性拔除智齿对切牙拥挤的影响,另1个随机对照试验正在进行,但研究者不能提供任何资料,他们准备近期发表文章,如是,其资料将被纳入本评价的更新中.已完成的2个研究结局判断指标不同,不能进行数据合并.结论没有证据支持或反对常规预防性拔除成年人无症状阻生智齿,有一些可靠的证据表明在青少年预防性拔除阻生智齿既不能减少也不能预防切牙拥挤.     

Thrombin generation during cardiopulmonary bypass: the possible role of retransfusion of blood aspirated from the surgical field

BACKGROUND: In spite of using heparin-coated extracorporeal circuits, cardiopulmonary bypass (CPB) is still associated with an extensive thrombin generation, which is only partially suppressed by the use of high dosages of heparin. Recent studies have focused on the origins of this thrombotic stimulus and the possible role of retransfused suctioned blood from the thoracic cavities on the activation of the extrinsic coagulation pathway. The present study was designed to find during CPB an association between retransfusion of suctioned blood from the pericardium and pleural space, containing activated factor VIIa and systemic thrombin generation. METHODS: Blood samples taken from 12 consenting patients who had elective cardiac surgery were assayed for plasma factor VIIa, prothrombin fragment 1+2 (F1+2), and thrombin-antithrombin (TAT) concentrations. Blood aspirated from the pericardium and pleural space was collected separately, assayed for F1+2, TAT, and factor VIIa and retransfused to the patient after the aorta occlusion. RESULTS: After systemic heparinization and during CPB thrombin generation was minimal, as indicated by the lower than base line plasma levels of F1+2, and TAT after correction for hemodilution. In contrast, blood aspirated from the thoracic cavities had significantly higher levels of factor VIIa, F1+2, and TAT compared to the simultaneous samples from the blood circulation (P < 0.05). Furthermore, after retransfusion of the suctioned blood (range, 200-1600 mL) circulating levels of F1+2, and TAT rose significantly from 1.6 to 2.9 nmol/L (P = 0.002) and from 5.1 to 37.5 μg/L (P = 0.01), respectively. The increase in both F1+2, and TAT levels correlated significantly with the amount of retransfused suctioned blood (r = 0.68, P = 0.021 and r = 0.90, P = 0.001, respectively). However, the circulating factor VIIa levels did not correlate with TAT and F1+2 levels. CONCLUSIONS: These data suggest that blood aspirated from the thoracic cavities during CPB is highly thrombogenic. Retransfusion of this blood may, therefore, promote further systemic thrombin generation during CPB.     

Self-perceived natural history of pelvic organ prolapse described by women presenting for treatment

Introduction and hypothesis  This study aimed to describe the self-perceived natural history of pelvic organ prolapse (POP) in women seeking care. Methods  Women presenting to a university-based urogynecology clinic for POP (n = 107) completed a questionnaire including questions about how and when their prolapse was discovered. A urogynecologic examination including the pelvic organ prolapse quantification (POP-Q) was also performed. Results  Forty-eight percent of these women sought medical attention “immediately” after discovering a bulge. The median time to seek care was 4 months (range from 1 month to 45 years). Twenty-six percent associated their prolapse with a specific event (e.g., moving furniture or pushing a car). POP was self-discovered by 76% (81/107) of women. Self-discovered prolapses were larger than those diagnosed by physicians (Ba +1.3 vs 0.1 cm, P = .03, respectively). Conclusions  Women seek medical advice within months of discovering their prolapse. Self-discovery is associated with higher stage prolapse than prolapse diagnosed by health care providers.     

Impaired contractile reserve in severe mitral valve regurgitation with a preserved ejection fraction

BACKGROUND: Impaired contractile reserve in chronic MR results from load-independent, myocyte contractile abnormalities. AIMS: Investigate the mechanisms of contractile dysfunction in chronic mitral valve regurgitation (MR). METHODS: Mild MR was produced in eight dogs followed by pacing induced left ventricular (LV) dilatation over eight months. In-vivo LV dP/dt was measured at several pacing rates. Contractile function was measured in isolated LV trabeculae and myocytes at several stimulation rates and during changes in extracellular [Ca2+]. Identical studies were performed with six control dogs. RESULTS: Chronic MR resulted in a preserved ejection fraction with decreased dP/dt (p<0.01). LV trabeculae demonstrated significantly lower developed force and a negative force-frequency relation with chronic MR (p<0.05). Myocytes exhibited a negative shortening-frequency relationship in both groups with a greater decline with chronic MR (p<0.001) paralleled by decreases in peak [Ca2+](i) transients. Increases in extracellular [Ca2+] abrogated the defects in force generation in trabeculae from animals with chronic MR. CONCLUSION: Even with a preserved EF, chronic severe MR results in a significant reduction in intrinsic contractile function and reserve. Functional impairment was load-independent reflecting a predominant defect in calcium cycling rather than impaired peak force generating capacity due to myofibrillar attenuation.     

Structure and function of murine cytomegalovirus MHC-I-like molecules: how the virus turned the host defense to its advantage

Immunologic Research - The mouse cytomegalovirus (CMV), a β-herpesvirus, exploits its large (~230&nbsp;kb) double-stranded DNA genome for both essential and non-essential functions. Among...