计算机X射线摄影新旧成像板的比较

目的 通过体模检测和病例检查的对照研究,比较计算机X射线摄影(computed radiography,CR)新旧两种不同成像板(IP)对影像质量和病人辐射的影响,探讨新旧IP的使用原则。方法 对新旧IP进行常规暗噪声、均匀性和一致性、擦除完全性检测;根据阈值对比度-细节检测能力(TCDD)技术,75 kV时新旧IP对体模TO.16进行摄影,请3位观察者采用双盲法对所得影像进行观察评分,计算阈值检测指数H_T(A);结合临床用相同曝光条件,不同的IP分别对膝关节、胸部、腰椎进行投照,请3位放射专家进行双盲阅片,评价影像质量。结果 新旧IP在物理指标上基本相同,在相同曝光条件下,新IP的检测能力高于旧IP,当旧IP提高20%的辐射剂量后,旧IP检测能力接近新IP。结论 随着IP使用次数的增加,需逐步提高曝光剂量才能保证影像质量;若保持原有剂量不变,IP的检测能力就会下降,将影响疾病的诊断。     

Smoothing the mosaic subclinical melanoderma by calcipotriol

BACKGROUND: The observation of photo-exposed skin under ultraviolet light reveals a mosaic pattern of varying intensity in epidermal melanization. Several patterns of mosaic subclinical melanoderma (MSM) have been described using a specially designed CCD camera and the ultraviolet light-enhanced visualization (ULEV) method. Vitamin D(3) and its analogues influence the biology of keratinocytes and melanocytes. OBJECTIVE: To assess the effect of calcipotriol on MSM. METHODS: This randomized split-face study was conducted in 27 men to compare the effect of once daily applications of 5% calcipotriol cream or a moisturizing cream on the heterogeneity of facial MSM. Computerized image analysis of video images was used at 1-month intervals before and during a 2-month treatment, as well as during a 3-month follow-up. RESULTS: At both sites, the average melanin content of the epidermis showed no significant change over time. However, the mottled appearance was smoothened at the calcipotriol site, whereas it was increased at the site receiving the moisturizer. CONCLUSION: The decreased heterogeneity in MSM after calcipotriol applications suggests a control of the epidermal melanocyte unit by the vitamin D(3) derivative.     

经皮微创锁定加压钢板内固定术的临床应用

目的探讨经皮微创锁定加压钢板内固定术的临床应用及其疗效。方法应用间接复位技术，通过建立骨折两端皮下隧道，采用锁定加压钢板内固定治疗胫腓骨干骨折15例，锁骨骨折12例，肱骨骨折4例。结果所有患随访4～18个月，平均10个月。骨折愈合时间：胫骨10～20周(平均12周)，1例骨折延迟愈合(20周)，无骨不愈合；锁骨6～10周(平均8周)，肱骨8～13周(平均11周)，均无骨折延迟愈合及不愈合。所有病例无感染及内固定失败等并发症。结论经皮微创锁定加压钢板内固定符合生物学固定(BO)原则，有利于骨折的愈合及软组织的修复。     

Detailed Analysis of Mucosal Restoration of the Small Intestine After the Cavitary Two-Layer Cold Storage Method

Small bowel transplantation (SBT) is associated with a high incidence of infectious complications because of ischemia/reperfusion (I/R) mucosal injury concomitant with potent immunosuppression. In this study, we evaluated whether the cavitary two-layer method (cTLM) could reduce I/R injury and allow early mucosal restoration, particularly after prolonged preservation and transplantation. Canine heterotopic segmental SBT was performed immediately without preservation (group 1), after 24-h preservation in UW solution (group 2) or by the cTLM (group 3). The graft samples were taken 1 h after reperfusion and on days 1, 4 and 7. We assessed graft mucosa with detailed microscopic and electromicroscopic analyses. In Group 3, histological injury and cell apoptosis after transplantation were significantly alleviated and rapidly recovered to a similar level of group 1. The mucosal restoration was morphologically completed within 4 days. In contrast, in group 2, more pronounced mucosal injury and delayed recovery were noted. Crypt cell proliferation activity was well maintained in groups 1 and 3 throughout the experimental period. Our ultrastructural analysis suggested that mitochondrial integrity achieved by the cTLM was a basal mechanism under the prompt mucosal restoration. The cTLM could reduce I/R injury, facilitate mucosal regeneration and restore the nearly normal structure early after SBT.     

用Alabama分析法比较安氏Ⅰ类错中国人与美国白人颅颌面结构差异

目的:研究中国安氏Ⅰ类错成人与美国安氏Ⅰ类错白人牙颌颅面形态结构的差异。方法:从西安市11所大学2098名新生中选取符合标准的101名(男53名、女48名)安氏Ⅰ类错样本。拍摄头颅定位X线片,用第四军医大学口腔医学院头影测量软件测量,用Alabama分析法与美国安氏Ⅰ类错白人颅颌面测量结果进行比较分析。结果:中国西安地区安氏Ⅰ类错成人上下颌突度大,面型较突;平面倾斜度、上下中切牙倾斜度及下中切牙至NB线距均较大;Y轴相对SN平面夹角增大,生长方向为后下。结论:与美国安氏Ⅰ类错白人比较,中国西安地区安氏Ⅰ类错成人颅面结构呈现颌骨突度大、下切牙唇倾及下颌趋向后下等特征。     

生长板软骨细胞促进骨髓基质干细胞血管内皮生长因子的表达

目的观察骨髓基质干细胞(BMSCs)在生长板软骨细胞旁分泌作用下血管内皮生长因子(VEGF)的表达规律及其与成骨分化的相关性。方法大鼠BMSCs与生长板软骨细胞进行间接共培养,培养终末期做细胞化学染色,定量测定碱性磷酸酶(ALP)活性,用RT-PCR方法半定量检测VEGFmRNA的表达。结果生长板软骨细胞持续高表达VEGF。BMSCs随共培养时间的延长,ALP活性升高,BMSCs的VEGF的表达也逐渐增强。培养液加入两种分泌型VEGF中和抗体后,VEGF表达趋势不变,ALP活性仍为升高趋势,也不影响培养终末期钙化结节的形成。培养终末期BMSCs的CD31和CD34均阴性。结论BMSCs成骨分化过程中VEGF的表达符合成骨细胞分化基因的表达规律,与成骨细胞特征性基因的表达趋势一致,体外条件共培养条件下,中和VEGF后并不能阻碍BMSCs的成骨分化。     

额、枕部直接冲击导致中脑损伤的力学机制研究

目的分析额、枕部直接冲击造成中脑应力响应,探讨颅脑直接冲击导致脑干损伤的力学机制。方法构建头颅三维有限元模型,模拟计算额、枕部直接冲击损伤,分析中脑上、下交界面节点应力分布,总结中脑应力响应。结果中脑-间脑界面在冲击初始阶段,2ms即出现应力增高,中脑-桥脑界面应力升高开始于冲击后期(10ms),两交界面节点应力在冲击时程中均持续升高,额部冲击比枕部冲击在中-间脑界面造成的应力峰值高。结论中脑在颅脑直接冲击伤的致伤机制中占有突出地位,中脑的应力改变可解释脑震荡的意识障碍及部分原发脑干伤的临床表现。     

内眦赘皮与重睑成形同期手术的一种新方法

目的 探索适合同时行重睑成形术和内眦赘皮矫正术的新方法。方法 根据内眦赘皮深部眼轮匝肌结构上的异常特点，遵循内眦赘皮的上睑（倒向性内眦赘皮除外）内侧睑缘处皮肤短缺和尽量减少局部皮肤瘢痕的原则，设计适合同时行重睑成形术的新内眦赘皮矫正术（反Stallard法）。结果 临床应用86例，进行了为期6个月以上的随访，结果所有患者的重睑为稳定性平行型重睑，内眦已完全或大部分开大，手术效果满意。结论 此内眦赘皮矫正术能够充分矫正内眦部结构上的异常，而且适合与重睑成形术同期施行，是一种效果稳定，结果满意的术式。     

颈椎后路螺钉-钛棒(板)内固定技术:初步临床报告

目的 报告利用螺钉-钛棒（板）固定技术治疗各种原因引起的颈椎不稳的初步临床结果。方法 作者1年来行颈椎后路螺钉-钛棒（板）技术内固定9例，其中齿突样骨引起的C1～C2不稳2例，手术后进行性颈椎后凸2例，颈椎管狭窄2例，C3-C4滑脱1例，C6～C7外伤滑脱2例。分别采用C1侧块、C2椎弓根螺钉、C3～C5侧块螺钉、C2-T2椎弓根螺钉植入技术，然后连接钛棒或钛板完成固定。9例病人共植入螺钉59枚。结果 所有病人在1周内带外支架进行活动，除1例因拒绝治疗死亡外，其余病人在1个月及1年后复查均未见内固定物移位。结论 颈椎后路螺钉-钛棒（板）固定为安全可靠的技术，可以术后即刻获得牢固内固定，为下一步治疗创造有利条件。     

胫骨平台解剖型钢板的结构特点及临床运用

目的探讨解剖型钢板治疗胫骨平台骨折的结构特点。方法2001年1月-2003年12月,应用解剖型钢板治疗胫骨平台骨折34例,其中男20例,女14例;年龄23~54岁,平均38.7岁。结果34例均获得随访,随访时间8~28个月,平均19个月。术后1个月膝关节屈曲70°~120°,平均90.2°;术后3个月膝关节屈曲90°~135°,平均110.3°;术后半年膝关节屈曲100°~135°,平均125.0°。按Merchant评分,终末随访时优18例,良12例,可4例。术后无切口皮肤坏死、感染和钢板松动及断裂。结论解剖钢板治疗胫骨平台骨折效果满意,其三维结构符合胫骨平台解剖特点,可以提供持续坚强的固定,有利术后膝关节早期活动,骨折愈合率高,并发症少。