GEE‐Based SNP Set Association Test for Continuous and Discrete Traits in Family‐Based Association Studies

Family‐based genetic association studies of related individuals provide opportunities to detect genetic variants that complement studies of unrelated individuals. Most statistical methods for family association studies for common variants are single marker based, which test one SNP a time. In this paper, we consider testing the effect of an SNP set, e.g., SNPs in a gene, in family studies, for both continuous and discrete traits. Specifically, we propose a generalized estimating equations (GEEs) based kernel association test, a variance component based testing method, to test for the association between a phenotype and multiple variants in an SNP set jointly using family samples. The proposed approach allows for both continuous and discrete traits, where the correlation among family members is taken into account through the use of an empirical covariance estimator. We derive the theoretical distribution of the proposed statistic under the null and develop analytical methods to calculate the P‐values. We also propose an efficient resampling method for correcting for small sample size bias in family studies. The proposed method allows for easily incorporating covariates and SNP‐SNP interactions. Simulation studies show that the proposed method properly controls for type I error rates under both random and ascertained sampling schemes in family studies. We demonstrate through simulation studies that our approach has superior performance for association mapping compared to the single marker based minimum P‐value GEE test for an SNP‐set effect over a range of scenarios. We illustrate the application of the proposed method using data from the Cleveland Family GWAS Study.     

Coconut kernel-derived proteins enhance hypolipidemic and antioxidant activity in alloxan-induced diabetic rats

Impaired lipid levels and oxidative stress are indicative of malfunction of endogenous antioxidant capacity. The aim of this study was to determine the effect of coconut kernel protein (CKP) on the lipid peroxides and antioxidant enzyme activities in diabetic rats. Diabetes was induced prior to feeding by injecting a single dose of alloxan (150 mg/kg body weight) intraperitoneally. CKP (8% w/w) was administered to these rats along with a semi-synthetic diet for 45 days. After the experimental period, peroxide products and antioxidant enzyme activities were determined. Results show that CKP maintained the antioxidant enzyme activities and levels of peroxides to the normal levels in treated group compared to diabetic rats. This study clearly show that CKP has potential effect in lowering oxidative stress associated with diabetes. This beneficial effect of CKP may be due to the high amount of biologically potent arginine present in it.     

Estimating treatment effects in a two‐arm parallel trial of a continuous outcome

For a continuous outcome in a two‐arm trial that satisfies normal distribution assumptions, we can transform the standardized mean difference with the use of the cumulative distribution function to be the effect size measure P(X < Y ). This measure is already established within engineering as the reliability parameter in stress–strength models, where Y represents the strength of a component and X represents the stress the component undergoes. If X is greater than Y, then the component will fail. In this paper, we consider the closely related effect size measure, This measure is also known as Somer's d, which was introduced by Somers in 1962 as an ordinal measure of association. In this paper, we explore this measure as a treatment effect size for a continuous outcome. Although the point estimates for λ are easily calculated, the interval is not so readily obtained. We compare kernel density estimation and use of bootstrap and jackknife methods to estimate confidence intervals against two further methods for estimating P(X < Y ) and their respective intervals, one of which makes no assumption about the underlying distribution and the other assumes a normal distribution. Simulations show that the choice of the best estimator depends on the value of λ, the variability within the data, and the underlying distribution of the data. Copyright © 2012 John Wiley & Sons, Ltd.     

HPLC法测酸枣仁合剂中阿魏酸的含量

目的建立酸枣仁合剂中阿魏酸的含量测定方法。方法采用HPLC法Hypersil-C18色谱柱，流动相分别为：乙腈-水（30：70）和甲醇．1％冰醋酸（28：72），检测波长分别为：204nm和322nm。结果HPLC法测定阿魏酸的含量，阿魏酸在0．2-0．6mg／ml范围内线形良好（r=0．9999），平均加样回收率为99．95％，RSD％为2．35％。结论方法简便，准确。     

杏仁提取条件的探讨

目的：研究苦杏仁中有效成分苦杏仁苷的最佳提取条件。方法：采用2次重复的正交实验法，以加水倍量，提取时间，提取次数3个因素，每个因素选取3个水平进行实验。结果：因素A（加水倍量）有显著影响，因素B（提取时间）和因素C（提取次数）对苦杏仁苷的含量有极显著影响。结论：最佳提取工艺A2B2C2，即用10倍量提取2次，每次1h。     

鸦胆子联合角膜缘干细胞移植治疗翼状胬肉

目的 :探讨鸦胆子在翼状胬肉联合手术中的安全性和有效性。方法 :在 41只眼的角膜缘干细胞移植联合翼状胬肉切除术中 ,用鸦胆子仁糊状粉末剂搽抹在巩膜创面的表面上 ,过五分钟后 ,使用注射用水将鸦胆子仁粉末从抹过的巩膜创面上冲洗掉。结果 :41例 (41只眼 )随访期间无复发 ,未见副作用及并发症。结论 :以鸦胆子仁技术行翼状胬肉切除角膜缘干细胞移植联合手术安全有效 ;术中应用鸦胆子可防止术后复发。     

Age-related changes in the first order Weiner kernel visual evoked potential

Visual evoked potentials were obtained from 112 subjects (215 eyes) aged 5 to 79 years with fast random stimuli. The stimulus (the presence or absence of the initiation of a reversal) and response (voltage measurements) were used in calculating the first order Wiener kernels to obtain the visual evoked potentials. Five check sizes were used to stimulate each eye. The implicit time of the major negative wave showed a significant increase with age for each check size used. Regression lines for the implicit time vs age data for male subjects were significantly different from those of females. The y-intercepts were lower and the slope of the regression lines were consistently steeper for males. Thus the rate of increase in implicit time was higher in males. The relationship of the amplitude of the major wave to age did not appear to be linear. The data suggested that a second-order polynomial curve might be an appropriate representation of the relationship.     

苦杏仁水煎剂对佐剂性关节炎大鼠抗炎作用研究

目的研究苦杏仁水煎剂对佐剂性关节炎(AA)大鼠的抗炎作用。方法建立AA大鼠模型,观察苦杏仁水煎剂对AA大鼠足肿胀、踝关节组织病理变化的影响。结果苦杏仁水煎剂能有效抑制AA大鼠关节肿胀及减缓组织炎症的发展。结论苦杏仁水煎剂对AA大鼠具有良好的抗类风湿关节炎作用,机制还需进一步探讨。     

火麻仁品种与药用部位本草考证

目的:通过对火麻仁的本草考证,明确火麻仁药材品种及入药部位,为临床用药提供文献依据。方法:考证历代本草著作,结合现代研究资料进行分析。结果:火麻仁的基原植物古今一致,均为桑科大麻属植物大麻Cannabis sativa。而入药部位,早期文献中对本品的药用部位并未作严格区分,麻賁(雌花序或未成熟的果实)、麻子(果实)、麻子仁(种仁)三者相互混用;自陶弘景开始,逐渐认识到其果皮的毒性,其后历代本草、方书大都特别指出大麻入药须去除果皮,使用种仁。现代药学文献对火麻仁药用部位的记载,或果实,或种仁,较混乱。结论:火麻仁品种古今一致;种仁比果实更安全,其药用部位应为种仁。     

基于小波支持向量回归的遥感多光谱图像分辨率增强算法

利用小波支持向量回归,实现了遥感多光谱图像分辨率的增强。首先采用非下采样Contourlet变换对低分辨率的多光谱图像和高分辨率的全色图像进行多分辨率分解,再利用小波支持向量回归对分解系数进行学习和预测,获得分辨率初步提高的多光谱图像,最后再与传统的插值方法得到的结果进行融合来实现多光谱图像分辨率增强。实验结果表明:此方法借遥感全色图像的辅助获得丰富的高频细节信息,使得分辨率增强结果无论是最小均方误差还是峰值信噪比都要优于仅依靠原图像本身放大的传统方法以及其他的分辨率增强方法。