Path analysis and sib-pair linkage

When the distance between linked loci is expressed in terms of the correlation between the identity-by-descent (idb) values of the loci, then a path model may be used to order loci with data on sib-pairs and their parents. The relationship between the recombination fraction and the correlation coefficient is developed and a method for fitting a covariance matrix predicted by a specific ordering of loci to an observed covariance matrix is proposed. © 1993 Wiley-Liss. Inc.     

福建产舟山眼镜蛇毒细胞毒素的快速分离纯化及鉴定

目的 从舟山眼镜蛇毒中分离纯化细胞毒素(CTX)，并鉴定其理化性质。方法 采用SP—Sephadex C-25阳离子交换色谱及Sephasil Peptide C18反相高效液相色谱法从舟山眼镜蛇毒中分离纯化CTX，SDS—PAGE(Tris—Tricine系统)鉴定纯度，Edman降解法测定N端氨基酸序列。结果 粗毒经阳离子交换色谱，得到14个蛋白峰，其中第X～XⅢ峰具CTX活性；再分别经反相色谱纯化，得到4个CTX．总得率为32.48％；SDS—PAGE显示为均一蛋白，分子量依次为：7．28，7．33，7．24和7．38kD；测定它们N端20个氨基酸序列。结论 采用阳离子交换和反相高效液相色谱可快速、高效地从眼镜蛇毒中获得4个CTX纯品。     

Mouthguards: difference in longitudinal dimensional stability between single- and double-laminated fabrication techniques

Abstract –  Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single-layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37°C water bath for 60 h, equivalent to the time period of 3-months inter-oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J-12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite-element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single-layer MGs in the anterior area ( P  < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single-layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process.     

鹅去氧胆酸连接氨基酸的合成

胆石症是一种常见病,鹅去氧胆酸(CDCA)可用于胆固醇胆石症的治疗。它能改变胆汁组成,降低胆汁内胆固醇饱和度,增加胆固醇溶解性,使胆石逐渐溶解。但CDCA易被肠道内细菌7-脱羟酶作用生成石胆酸(LC),引起腹泄、腹部痉挛、高转     

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.     

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。     

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。     

组织工程心肌补片对黑山羊陈旧性心肌梗死心功能和建立侧支循环的影响

目的探讨自体骨髓间充质干细胞(m arrow m esenchym a l stem ce lls,M SC s)-小肠黏膜下层(sm a llin testina l subm ucosa,S IS)构建的组织工程心肌补片,移植于陈旧性心肌梗死区后对心功能及缺血区建立侧支循环的影响。方法将已建立急性心肌梗死模型后6周的黑山羊16只,随机分为实验组和对照组,实验组抽取自体骨髓,经体外分离M SC s,进行培养、传代,以第3代细胞行5-B rdU标记并与S IS支架材料复合培养5 d,制备M SC s-S IS组织工程心肌补片。将其缝合至陈旧性心肌梗死区;对照组仅行假手术处理。于植入后6周,采用超声心动图观察两组动物心功能变化,数字减影血管造影选择性左冠状动脉造影观察缺血心肌侧支循环的建立。结果术后6周实验组及对照组:心博出量、左心室射血分数分别为42.81±4.91、37.06±4.75 m l和59.20%±5.41%和44.56%±4.23%,组间差异均有统计学意义(P<0.05);左心室舒张末期容积、左室收缩末期容积分别为72.55±8.13、83.31±8.61 m l和29.75±5.98、46.25±6.68 m l,组间差异均有统计学意义(P<0.05);左心室舒张功能各项指标分别为:E峰最大速度分别为54.85±6.35 cm/s和43.14±4.81cm/s(P<0.01);A峰最大速度分别为52.33±6.65 cm/s和56.91±6.34 cm/s(P>0.05)。超声心动图显示对照组左室腔扩张明显,室壁运动明显减弱,梗死区呈瘤样扩张,局部室壁反常运动;实验组左室腔明显小于对照组,室壁运动较对照组强,心尖梗死区扩张不明显。选择性左冠状动脉造影见实验组左冠状动脉前降支远端与回旋支间明显侧支循环建立。结论M SC s-S IS构建的组织工程心肌补片移植于黑山羊陈旧性心肌梗死区后侧支循环建立,心功能有明显改善作用。