上肢骨肿瘤切除后的自体骨移植重建

目的探讨应用自体骨移植对上肢骨肿瘤切除后的骨缺损修复重建的效果。方法1998年8月～2004年3月，收治上肢骨肿瘤切除后的骨缺损16例。男8例，女8例。年龄7～45岁。经病理确诊，肱骨近端尤文肉瘤和骨肉瘤各1例；肱骨远端尤文肉瘤2例；桡骨远端骨巨细胞瘤8例，高分化软骨肉瘤2例，恶性纤维组织细胞瘤和骨肉瘤各1例。2例肱骨近端肿瘤行自体锁骨代肱骨；2例肱骨远端肿瘤行自体腓骨代肱骨；12例桡骨远端肿瘤中，1例行自体髂骨移植，11例行自体腓骨代桡骨进行重建。采用MSTS系统进行术后功能评价。结果2例肱骨近端自体锁骨移植患者分别随访36个月和12个月，术后保持部分肩关节前屈和后伸功能，但外展功能丧失；MSTS评分分别为23分和22分。2例肱骨远端自体腓骨移植患者分别随访4个月和6个月，肘关节功能良好，移植骨连接处已经出现骨愈合；MSTS功能评分分别为24分和19分。12例桡骨远端自体骨移植患者中11例随访6～75个月，功能良好，无明显并发症；1例髂骨植骨的桡骨远端骨巨细胞瘤术后3个月移植骨完全愈合，至今随访75个月，肿瘤无复发。MSTS功能评分18~27分，平均22．6分。结论自体骨移植在上肢骨肿瘤切除后骨缺损的重建，尤其是儿童的骨缺损重建中，是一种较好的方法。     

Estimation of policy effects using parametric nonlinear models: a contextual critique of the generalized method of moments

The typical empirical study in health services and outcomes research is aimed at estimating the causal effect that an exogenously imposed condition (e.g. a policy mandate) will have (or has had) on a specified outcome of interest. Controlling for unobservable confounding influences is of primary importance in such analyses. The instrumental variables (IV) method has been widely used for this purpose in the linear regression context. The present paper examines the pros and cons of alternative versions of the generalized method of moments (GMM) [of which the IV estimator is a special case] for the estimation of policy effects when endogeneity is present in a nonlinear regression setting. We show that conventional GMM is difficult to implement for policy analysis because it does not typically accommodate symmetry—similar treatment of both observable and unobservable confounders in the regression specification. Although, simple additive (nonsymmetric) regression specifications afford practical GMM estimators, they are difficult to defend from both intuitive and conceptual standpoints. Moreover, as we show via simulation, if symmetry is ignored and conventional GMM is applied based on an incorrectly specified non-symmetric model, then policy analytic estimates can be seriously biased. As a result, prospects for the development and application of intuitive consistent GMM-based policy effect estimators are dim. The problem stems from the reasonable desire on the part of the researcher to derive GMM estimators in the nonlinear framework that are based solely upon the conventional minimalist linear IV assumptions. We show, in the context of our formulation of a simple but consistent alternative to GMM in the probit case, that intuitively appealing additional assumptions about the data generating process of the policy variable will often be sufficient for the development of desirable alternatives to the GMM.     

hs-CRP、TAS联合血脂检测在早老性痴呆症诊断中的应用研究

[目的]研究超敏C反应蛋白（hs-CRP）、总抗氧化状态（TAS）联合血脂检测在早老性痴呆症诊断中的应用价值：[方法]选择浦东新区精神卫生中心早老性痴呆专科门诊患者54例，作超敏C反应蛋白、总抗氧化状态与血脂检测。[结果]与对照组比较，实验组hs-CRP、TAS差异非常显著，t1=4．55，t2=2．79，P1〈0．001，P2〈0．01；血脂中甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B、Lp（a）差异显著；t1=3.01，P1〈0．01，t2=2．21，P2〈0．05，t3=2．64，P3〈0．01，t4=1．91，P4〈0．05。[结论]超敏C反应蛋白、总抗氧化状态联合血脂（甘油三酯、低密度脂蛋白胆固醇、载脂蛋白B、Lp（a））检测对实验室诊断早老性痴呆症具有较好敏感性和特异性，临床应用前景乐观。     

Treatment of Acquired Bilateral Nevus of Ota-Like Macules (Hori''s Nevus) with a Combination of the 532 nm Q-Switched Nd:YAG Laser Followed by the 1,064 nm Q-Switched Nd:YAG Is More Effective: Prospective Study

BACKGROUND: Acquired bilateral nevus of Ota-like macules (Hori's nevus) is a common dyschromatosis among Asian women. Q-switched lasers have been used successfully as a treatment modality. OBJECTIVE: The purpose of this study was to compare the efficacy of using the Q-switched 532 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser followed by the 1,064 nm laser versus the Q-switched 1,064 nm Nd:YAG laser alone in the treatment of Hori's nevus. METHODS: This is a prospective left-right comparative study. Ten women with bilateral Hori's nevus were recruited and treated with a combination of the Q-switched 532 and 1,064 nm Nd:YAG lasers on the right cheek and the Q-switched 1,064 nm Nd:YAG laser alone on the left cheek. Only one laser treatment session was performed. The degree of pigmentation was objectively recorded with a mexameter. Subjective assessment was made by both patients and two blinded, nontreating dermatologists. RESULTS: At 6 months, there was a statistically significant difference (p = .009) of 35.10 points using objective mexameter measurements between the two sides, favoring the side treated with a combination of 532 and 1,064 nm laser treatment. Subjective grading by the patients and blinded dermatologists also confirmed that combination therapy was more successful after one treatment. Although combination treatment had a higher incidence of mild postinflammatory changes, this disappeared within 2 months. CONCLUSIONS: Concurrent use of the Q-switched 532 nm Nd:YAG laser in combination with the 1,064 nm laser is more effective in pigment clearance than the Q-switched 1,064 nm Nd:YAG laser alone for Hori's nevi.     

Ultrasound Examination and Localization of the Sciatic Nerve: A Volunteer Study

Background: Few studies have examined the use of ultrasound for sciatic nerve localization. The authors evaluated the usefulness of low-frequency ultrasound in identifying the sciatic nerve at three locations in the lower extremity and in guiding needle advancement to target before nerve stimulation.

Methods: In this prospective observational study, 15 volunteers underwent sciatic nerve examination using a curved ultrasound probe in the range of 2-5 MHz and a Philips-ATL 5000 unit (ATL Ultrasound, Bothell, WA) in the gluteal, infragluteal, and proximal thigh regions. Thereafter, an insulated block needle was advanced inline with the ultrasound beam to reach the nerve target, which was further confirmed by electrical stimulation. The quality of sciatic nerve images, ease of needle to nerve contact, threshold stimulating current, and resultant motor response were recorded.

Results: The sciatic nerve was successfully identified in the transverse view as a solitary predominantly hyperechoic structure on ultrasound in all of the three regions examined. The target nerve was visualized easily in 87% and localized within two needle attempts in all patients. Nerve stimulation was successful in 100% after two attempts with a threshold current of 0.42 +/- 0.12 (mean +/- SD) eliciting foot plantarflexion or dorsiflexion.