胃癌D17S261和D17S799位点二核苷酸重复序列不稳定性的意义

目的研究二核苷酸重复序列不稳定性〔ＤＲＳＩ〕在胃癌发生中的作用及其临床意义．方法采用ＰＣＲ方法检测了Ｄ１７Ｓ２６１和Ｄ１７Ｓ７９９位点二核苷酸重复序列不稳定性．结果胃癌总ＤＲＳＩ发生率为３４％（１７／５０），其中高中分化腺癌ＤＲＳＩ阳性率（６６７％，１０／１５）显著高于低分化癌（１９４％，６／３１，Ｐ＜００１）；肠型胃癌ＤＲＳＩ阳性率（５５６％，１０／１８）显著高于胃型胃癌（２０％，６／３０，Ｐ＜００５），ＤＲＳＩ与胃癌部位、大小、浸润、分期、淋巴结转移无显著相关．结论ＤＲＳＩ在胃癌的发生中可能起重要作用．     

含辛伐他汀药物血清对兔血管平滑肌细胞增殖的直接作用及意义

目的 :探讨辛伐他汀对体外培养兔血管平滑肌细胞增殖的影响及意义。方法 :16只雄性新西兰兔随机分为血清对照组和三个不同剂量的辛伐他汀亚组 (每日分别给予辛伐他汀 5mg/kg、10mg/kg、15mg/kg) ,7天后采血并混合每组 4只兔血 ,无菌分离制备三亚组的辛伐他汀含药血清。采用内皮素 1(ET 1)刺激正常喂饲原代培养兔主动脉血管平滑肌细胞的方法 ,建立血管平滑肌细胞增殖模型。采用MTT及3H TdR法检测各组辛伐他汀含药血清对血管平滑肌细胞增殖的作用。结果 :与不含药的正常对照组相比 ,不同亚组辛伐他汀含药血清呈剂量依赖性抑制血管平滑肌细胞增殖 (P <0 .0 1～0 .0 5 )。结论 :兔口服辛伐他汀后的血清具有抑制血管平滑肌细胞增殖的作用     

TIMP-2拮抗胃癌SGC-7901细胞侵袭能力实验研究

目的 探讨基质金属蛋白酶抑制剂－２（ＴＩＭＰ－２）对ＳＧＣ－７９０１胃癌细胞体外侵袭能力的影响。方法 将人全长ＴＩＭＰ－２基因经脂质包裹转染ＰＡ３１７细胞系,Ｇ４１８筛选,感染人ＳＣＧ－７９０１胃癌细胞系,经体外细胞和电泳率、软琼脂形成和侵袭能力均明显低于对照组,而与对照组相比细胞增殖曲线没有明显的变化。结论 ＴＩＭＰ－２基因转染可以肿瘤细胞的表面电荷发生变化,使细胞的电泳能力、细胞的移动性和侵袭     

移动心电信号QRS波形相似度指标的选择方法

目的：对移动心电信号QRS波形相似度指标进行评价和筛选，以便快速、准确地对心电图信号进行分类。 方法：实验于2005-06／12在解放军第三军医大学野战外科研究所，创伤、烧伤与复合伤国家重点实验室完成。①利用心电图信号建立带有个性化的正常QRS波群模板。②用待测波形与模板的绝对误差和相对近似值作为QRS波群的评价指标。③通过各指标与QRS波群关键参数、QRS波群类别的对照关系，以及评价指标相互比较的方法进行评价。 结果：①能量相似度评价指标在整个QRS宽度的分布上没有明显的特征，数值都集中在0．95-1．0之间，对QRS波群不具有区分性。②利用波形相关分析计算的相对评价指标对窦性和室上性QRS波群的分辨准确率高达99、99％，但对室性波和噪声的分辨率仅为21．57％和16．92％。③绝对误差相似度评价指标对QRS波群的分辨总体上可达到97．84％．对异位波形与噪声的区分准确率为100％和95．38％，对窦性和室上性QRS波群的分辨率为98．13％。④相关评价指标和绝对误差指标联合应用对QRS波群分辨率高达99.48％。 结论：所设计的绝对相似度和相对相似度评价指标，在一定程度上都能反映移动心电信号的QRS波群的特征信息。由于二者各具优缺点，将两种评价指标结合使用，可以提高QRS波群评判的准确性，在信号分类中可做到快速性与准确性的统一。     

Comparison of acute pneumonia caused by SARS-CoV-2 and other respiratory viruses in children:a retrospective multi-center cohort study during COVID-19 outbreak

Background:Until January 18,2021,coronavirus disease-2019 (COVID-19) has infected more than 93 million individuals and has caused a certain degree of panic.Vira...     

Binocular form deprivation influences the visual cortex

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors are considered to play a crucial role in synaptic plasticity in the developing visual cortex. In this study, we established a rat model of binocular form deprivation by suturing the rat binocular eyelids before eye-opening at postnatal day 14. During development, the decay time of excitatory postsynaptic currents mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors of normal rats became longer after eye-opening; however, the decay time did not change significantly in binocular form deprivation rats. The peak value in the normal group became gradually larger with age, but there was no significant change in the binocular form deprivation group. These findings indicate that binocular form deprivation influences the properties of excitatory postsynaptic currents mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the rat visual cortex around the end of the critical period, indicating that form stimulation is associated with the experience-dependent modification of neuronal synapses in the visual cortex.     

Racial variations in knee joint laxity: A comparative study of the Jordanian Arab and Malay populations

BackgroundA high incidence of joint laxity has been reported among Asians compared with Western populations, but clear differences between more specific ethnic populations have not been established. This study aimed to determine the average knee laxity in the Malaysian and Jordanian populations.MethodsJordanian and Malaysian medical students from our institution were invited to participate in the study. General demographic data and factors affecting joint laxity were obtained from each participant using a printed questionnaire. Both knees were examined using the anterior drawer test while in 90° of flexion. Knee laxity was measured by three separate independent investigators through a knee laxity tester.ResultsOne hundred and eighty-six participants (95 females) were enrolled in the study. Among them, 108 Malaysians participated. The Jordanians had significantly higher knee laxity in both knees compared with the Malaysians. The mean average right knee laxity for Jordanians was 2.98 mm vs. 2.72 mm for Malaysians (P = 0.005). Similarly, the mean average left knee laxity for Jordanians was 2.95 mm, while for Malaysians, it was 2.62 mm (P = 0.0001). Furthermore, smokers had significantly more laxity in both knees. After performing a multivariate linear regression analysis for all factors, race was the only independent factor that affected knee laxity in both knees.ConclusionsRace is directly associated with knee laxity. Jordanians tend to have more laxity in knee joints compared with Malaysians. Larger multi-center and genetic studies are recommended to establish the racial differences between different ethnic groups.     

The relation between aortic arch branching types and the location of large vessel occlusion in cardioembolic stroke

Cardiac embolism is the leading etiology of ischemic strokes. There are arguments about the left–right propensity of cardioembolic strokes. This study aimed to reveal the relationship between the different aortic arch types and the location of large vessel occlusion (LVO) in cardioembolic stroke. We retrospectively identified all patients with acute ischemic stroke admitted to our comprehensive stroke center who had medium- to high-risk cardioembolic sources according to the TOAST classification. Only those with LVO and available images of the aortic arch were included. Patients were classified into 3 groups according to the aortic arch types: Type I (n = 44), Type II (n = 105), Type III (n = 36). The thrombus was divided into large thrombus or small thrombus based on the location of LVO. Overall, left-sided strokes (50.8%) were almost equal to right-sided (49.2%). There was a growing tendency for the percentage of left-sided infarcts with advancement of the aortic arch types either in the total cases or in the atrial fibrillation cases, with no statistical difference between the 3 aortic arch types. In type III aortic arch, left-sided strokes (69.0%) were twice than right-sided (31%) in large thrombus (P < 0.05), while right-sided strokes (85.7%) were more common than left-sided (14.3%) in small thrombus (P < 0.05). Conversely, in type Ⅰ and II aortic arches, left-sided strokes were more common than right-sided in small thrombus, while right-sided strokes were more common than left-sided in large thrombus (P < 0.05). The left–right propensity of cardioembolic stroke is related to the proximity of clot lodging in different aortic arch types.