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1.
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.  相似文献   
2.
目的 优选清热除湿止痛液的提取工艺。方法 在单因素考察的基础上,以信息熵理论结合星点设计-效应面法,对浸泡时间、提取时间、加水量及提取次数进行考察,以绿原酸、龙胆苦苷、络石苷的含量及干膏得率为评价指标,采用信息熵理论对各评价指标赋予权重系数,并计算综合评分。通过Design-Expert 8.0.6.1软件分析各因素间的交互作用,得出优化的水提取工艺,并对该工艺进行验证实验。结果 依据信息熵理论,将绿原酸、龙胆苦苷、络石苷及干膏得率的权重系数分别确定为0.16、0.76、0.05、0.03;交互作用分析结果显示,浸泡时间对综合评分影响较大。清热除湿止痛液的最佳提取工艺确定为浸泡53 min,加9倍量水,提取3次,每次105 min;验证结果显示,各指标成分含量及综合评分RSD均小于3%。结论 优化的水提取工艺稳定、可行,可为清热除湿止痛液的进一步开发利用提供参考。  相似文献   
3.
目的:探讨清热祛瘀汤对慢性盆腔炎性疾病模型大鼠的炎性反应细胞因子及粘连相关免疫分子的影响。方法:选取100只Wistar雌性大鼠为研究对象,以随机分组方式将其分为5组,分别为模型对照组、假手术组、清热祛瘀汤组(包括低、中、高3种不同剂量),每组20只;除假手术组外,其余5组均建立盆腔炎性疾病大鼠模型;于清热祛瘀方作用下对其炎性反应细胞因子、血液流变学、粘连相关免疫分子变化情况进行分析。结果:与假手术组比较,模型对照组大鼠血液流变学各指标均明显升高变(P<0.05);而经治疗后,各指标均明显下降,且与模型对照组比较差异均有统计学意义(P<0.05);模型对照组与假手术组比较,大鼠血清IL-4、IL-10、TNF-α、IgA、IgG差异均有统计学意义(P<0.05);经治疗后,清热祛瘀方各剂量组各指标水平均发生明显改变(P<0.05)。结论:清热祛瘀汤对慢性盆腔炎性疾病模型大鼠的炎性反应细胞因子及粘连相关免疫分子、血液流变学均有较大影响,可推广应用。  相似文献   
4.
目的观察芪莲化积合剂对肝癌H22荷瘤小鼠的抗肿瘤作用。方法建立肝癌H22荷瘤小鼠实体瘤模型,将24只小鼠分为3组,对照组(生理盐水组)、芪莲化积合剂组和5-氟脲嘧啶(5-Fu)组各8只。通过测定荷瘤小鼠的瘤重、抑瘤率观察芪莲化积合剂剂对肿瘤生长的影响,采用RT-PCR技术检测miRNA122的表达情况。结果芪莲化积合剂能使肝癌H22荷瘤小鼠的瘤重减少,显著低于对照组(P<0.05);胸腺指数、脾指数的比较,芪莲化积合剂较对照组明显升高(P<0.05);在miRNA122的表达上,芪莲化积合剂较对照组明显升高(P<0.05)。结论芪莲化积合剂具有明显的抗肿瘤作用,其作用机制可能与miRNA122的表达有关。  相似文献   
5.
目的:观察清热化湿通腑汤联合奥曲肽治疗急性胰腺炎(AP)患者的效果。方法:选取86例AP患者为研究对象,按照随机数字表法分为对照组与研究组各43例。对照组经静脉注射奥曲肽治疗,研究组在对照组基础上联合清热化湿通腑汤治疗。比较两组疗效、症状缓解时间、炎性因子[白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、超敏C反应蛋白(hs-CRP)]水平。结果:研究组治疗总有效率高于对照组,差异有统计学意义(P<0.05);研究组治疗后胃肠功能恢复时间、血淀粉酶恢复时间、尿淀粉酶恢复时间、体温恢复时间均短于对照组,IL-6、TNF-α、CRP水平均低于对照组,差异有统计学意义(P<0.05)。结论:清热化湿通腑汤联合奥曲肽治疗AP患者,可提高治疗总有效率,缩短症状缓解时间,以及降低炎性因子水平,效果优于单纯奥曲肽治疗。  相似文献   
6.
<正>咳喘合剂是杭州市红十字会医院的临床经验方,由蜜麻黄、蜜款冬花、蜜紫菀、浙贝、黄芩、前胡、甘草等12味中药组成,具有宣肺平喘,止咳化痰的功效,临床用于小儿急慢性支气管炎、哮喘、过敏性咳嗽及上呼吸道感染、感冒后痒咳等症。为了规范咳喘合剂的提取工艺,确保制剂的疗效,根据处方中药物各组分的理化性质及药理特点,结合中医临床用药经验,采用正交实验法对咳喘合剂进行了提取工  相似文献   
7.
Diagnosis of motor neurone disease (MND) includes detection of small, involuntary muscle excitations, termed fasciculations. There is need to improve diagnosis and monitoring of MND through provision of objective markers of change. Fasciculations are visible in ultrasound image sequences. However, few approaches that objectively measure their occurrence have been proposed; their performance has been evaluated in only a few muscles; and their agreement with the clinical gold standard for fasciculation detection, intramuscular electromyography, has not been tested. We present a new application of adaptive foreground detection using a Gaussian mixture model (GMM), evaluating its accuracy across five skeletal muscles in healthy and MND-affected participants. The GMM provided good to excellent accuracy with the electromyography ground truth (80.17%–92.01%) and was robust to different ultrasound probe orientations. The GMM provides objective measurement of fasciculations in each of the body segments necessary for MND diagnosis and hence could provide a new, clinically relevant disease marker.  相似文献   
8.
A mixture model is described, which accommodates different Markov processes governing disease progression in a finite set of latent classes. We give special attention to the setting in which individuals are examined intermittently and transition times are consequently interval censored. A score test is developed to identify genetic markers associated with class membership. Simulation studies are conducted to validate the algorithm, assess the finite sample properties of the estimators, and assess the frequency properties of the score tests. A permutation test is recommended for settings when there is concern that the asymptotic approximation to the score test is poor. An application involving progression in joint damage in psoriatic arthritis (PsA) provides illustration and identifies human leukocyte antigen markers associated with unilateral and bilateral sacroiliac damage in individuals with PsA.  相似文献   
9.
This paper introduces a test of superiority of new anti-infective drug B over comparator drug A based on a randomized clinical trial. This test can be used to demonstrate assay (trial) sensitivity for noninferiority trials and rigorously tailor drug choice for individual patients. Our approach uses specialized baseline covariates XA,XB, which should predict the benefits of drug A and drug B, respectively. Using a response surface model for the treatment effect, we test for superiority at the (XA,XB) point that is most likely to show superiority. We identify this point based on estimates from a novel half-blind pseudo likelihood, where we augment a blinded likelihood (mixed over the treatment indicator) with likelihoods for the overall success rates for drug A and drug B (mixed over XA,XB). The augmentation results in much better estimates than those based on the mixed blinded likelihood alone but, interestingly, the estimates almost behave as if they were based on fully blinded data. We also develop an analogous univariate method using XA for settings where XB has little variation. Permutation methods are used for testing. If the “half-blind” test rejects, pointwise confidence interval can be used to identify patients who would benefit from drug B. We compare the new tests to other methods with an example and via simulations.  相似文献   
10.
Background: Maltreated children experience a variety of adverse outcomes including substance use problems. Although previous research indicated that there may be distinct trajectories of substance use among these youth, studies have examined them as if they were a single homogeneous group. Objectives: The goals of this study were to explore substance use trajectories among child welfare-involved youth and to identify characteristics that distinguish substance use trajectories. Methods: Data from the National Survey of Child and Adolescent Well-Being (NSCAW II) were used. Multilevel latent growth mixture modeling (MLGMM) was performed using a subsample of 625 youth from ages 11–17 years investigated for maltreatment in 2008–2009. Measures included self-reported use of substance use during the previous 30 days, demographic characteristics, maltreatment history, placement in out-of-home care, and behavioral health problems. Results: MLGMM identified two distinct substance use trajectory classes including High Stable Substance Use and Rapid Progression Use. Findings suggest that the experience of physical abuse is the key factor that distinguishes the two groups. When the effects of class-specific covariates were examined, results suggest that involvement in substance use behavior and its escalation vary between groups and are affected by youth’s different previous experiences. Conclusions/Importance: The results have important implications for understanding individual differences in substance use behavior over time and how these differences were shaped by youth’s experiences of family adversity. Study findings may be helpful for developing and enhancing the effectiveness of interventions targeted at decreasing substance use behaviors in child welfare-involved youth.  相似文献   
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