Bayesian consensus clustering for multivariate longitudinal data

In clinical and epidemiological studies, there is a growing interest in studying the heterogeneity among patients based on longitudinal characteristics to identify subtypes of the study population. Compared to clustering a single longitudinal marker, simultaneously clustering multiple longitudinal markers allow additional information to be incorporated into the clustering process, which reveals co-existing longitudinal patterns and generates deeper biological insight. In the current study, we propose a Bayesian consensus clustering (BCC) model for multivariate longitudinal data. Instead of arriving at a single overall clustering, the proposed model allows each marker to follow marker-specific local clustering and these local clusterings are aggregated to find a global (consensus) clustering. To estimate the posterior distribution of model parameters, a Gibbs sampling algorithm is proposed. We apply our proposed model to the primary biliary cirrhosis study to identify patient subtypes that may be associated with their prognosis. We also perform simulation studies to compare the clustering performance between the proposed model and existing models under several scenarios. The results demonstrate that the proposed BCC model serves as a useful tool for clustering multivariate longitudinal data.     

Multivariate modelling of responses to conditional items: New possibilities for latent class analysis

Questionnaire data may contain missing values because certain questions do not apply to all respondents. For instance, questions addressing particular attributes of a symptom, such as frequency, triggers or seasonality, are only applicable to those who have experienced the symptom, while for those who have not, responses to these items will be missing. This missing information does not fall into the category ‘missing by design’, rather the features of interest do not exist and cannot be measured regardless of survey design. Analysis of responses to such conditional items is therefore typically restricted to the subpopulation in which they apply. This article is concerned with joint multivariate modelling of responses to both unconditional and conditional items without restricting the analysis to this subpopulation. Such an approach is of interest when the distributions of both types of responses are thought to be determined by common parameters affecting the whole population. By integrating the conditional item structure into the model, inference can be based both on unconditional data from the entire population and on conditional data from subjects for whom they exist. This approach opens new possibilities for multivariate analysis of such data. We apply this approach to latent class modelling and provide an example using data on respiratory symptoms (wheeze and cough) in children. Conditional data structures such as that considered here are common in medical research settings and, although our focus is on latent class models, the approach can be applied to other multivariate models. Copyright © 2009 John Wiley & Sons, Ltd.     

Seasonal variation in the content of a febrifugine and isofebrifugine alkaloid mixture in aerial parts of <Emphasis Type="Italic">Hydrangea macrophylla</Emphasis> var. <Emphasis Type="Italic">Otaksa</Emphasis>, with special reference to its antimalarial activity

Febrifugine and isofebrifugine alkaloid mixtures extracted from the leaves and buds of Hydrangea macrophylla var. Otaksa, collected during different months, in Japan, were quantified using high-performance liquid chromatography. Leaves collected during the flowering season, namely from June to August, contained 0.16–0.31 mg/g of the alkaloid mixture, whereas those collected from September to December had less than 0.03 mg/g of the mixture. However, extracts of buds harvested from October to February contained a consistently larger amount (more than 0.49 mg/g) of the alkaloids. Hot-water extracts from the leaves and buds collected during different seasons were evaluated for antimalarial activity against Plasmodium yoelii 17XL in mice. The extract of leaves collected in August demonstrated high antimalarial activity, and all mice that received the extract survived the infection. In contrast, the extract of leaves collected in December showed little activity. The extract of buds collected in December cleared parasites, but with subsequent mortality to mouse. The present results show that the amount of antimalarial agent—febrifugine and isofebrifugine mixture—in H. macrophylla var. Otaksa is both part- and season-dependent, suggesting that the choice of plant parts and their harvesting season are important factors worth considering in the pharmacological use of medicinal plants.     

大黄(庶虫)虫丸治疗囊肿性痤疮的临床疗效评价

目的　观察大黄虫丸治疗囊肿性痤疮的临床疗效。　方法　选择囊肿性痤疮患者 33 例做为治疗组,给予口服大黄虫丸治疗,观察并记录结果。　结果　治疗的总有效率为 90 9%,对照组(P<0 05)。　结论　大黄虫丸对囊肿性痤疮有较好的临床疗效。     

地黄合剂降血糖作用的实验性研究

本文通过用四氧嘧啶复制小白鼠糖尿病模型,以血清中血糖及胰岛素水平为指标,研究了地黄合剂对高糖动物的降血糖作用。结果表明,注射四氧嘧啶前小白鼠血糖为173.47±5.23mg/100ml注射后血糖升高至419.78±22.70mg/100ml(P<0.01),差异有高度显著性。实验组服用地黄合剂后,血糖值从410.25±2739mg/100ml下降至313.51±29.39mg/100ml(P<0.05)差异有显著性。因而认为地黄合剂对于四氧嘧啶性糖尿病有显著的降血糖作用。     

温经化瘀合剂临床疗效观察与研究

目的:验证"温经化瘀舍剂"对妇女寒凝血瘀型痛经的治疗效果;方法:将符合中医诊断标准寒凝血瘀型痛经患者,随机分为2组,分别给予"温经化瘀合剂"和"痛经宁冲剂"进行治疗;结果:治疗组总有效率达95%,对照组总有效率80.5%,治疗组优于对照组,治疗组痊愈率48.3%,对照组痊愈率14.6%,治疗组明显优于对照组.实验动物无明显急性毒性反应,能减轻二甲苯引起的小鼠耳肿胀度,减少缩宫素所致大鼠扭体反应次数,和前列腺素E1所致小鼠扭体反应次数,对大鼠离体子宫有双向调节作用,证明"温经化瘀舍剂"具有镇痛、抗炎作用.     

舒肤特治疗痤疮疗效观察

目的　探讨舒肤特对座疮的治疗作用。　方法　病人随机分为治疗组和对照组。治疗组 45例 ,男 2 8例 ,女 17例 ;对照组 45例 ,男 2 5例 ,女 2 0例。年龄 14～ 42岁 ,平均 2 4岁。病程 2周～ 6年。治疗组用舒肤特 ,对照组用2 5 %氯霉素酊 ,每日 2次 ,4～ 8周为 1疗程。每周复诊 1次。　结果　治疗组痊愈率 3 7 8% ,总有效率 84 5 % ,对照组痊愈率 17 8% ,总有效率 62 2 % ,治疗组痊愈率优于对照组 ( χ2 =10 0 2 ,P <0 0 1) ,两组总有效率差异有显著性 ( χ2=11 42 8,P <0 0 1) ,　结论　舒肤特是中西药复方制剂 ,其用于治疗痤疮效果较好 ,无明显副作用。     

Surgical treatment of acne scarring by using skin grating knife

Summary A method of dermaplaning for acne scarring using a skin graft knife is described. This surgical technique cannot be considered as a form of dermabrasion. Its advantages are reported.     

Continuous flow synthesis of peptides using a polyacrylamide gel resin (Expansin™)

The continuous flow syntheses of endothelin 1, proendothelin 2. ATP binding site of the CDC2 kinase 3, and fragment 18-30 of an actin 4, have been performed by using a polyacrylamide gel resin Expansin? (about 0.6 mmol NH₂/g) with the glycolamidic ester handle as labile anchorage. In addition, we report here a method of air oxidation which reduces the formation of side-products related to the formation of intermolecular disulfide bridges.