Sufficient dimension reduction on the mean and rate functions of recurrent events

The counting process with a Cox‐type intensity function has been extensively applied to analyze recurrent event data, which assume that the underlying counting process is a time‐transformed Poisson process and that the covariates have multiplicative or additive effects on the mean and rate functions of the counting process. The existing statistical inference, however, often encounters difficulties due to high‐dimensional covariates, such as in gene expression and single nucleotide polymorphism data that have revolutionized our understanding of cancer recurrence and other diseases. In this paper, a technique of sufficient dimension reduction is applied to the mean and rate function for the number of occurrences of events over time. A two‐step procedure is proposed to estimate the model components: first, a nonparametric estimator is proposed for the baseline, and then the basis of the central subspace and its dimension are estimated through a modified slicing inverse regression. On the basis of the estimated structural dimension and on the basis of the central subspace, we can estimate the regression function by using the local linear regression. A simulation is performed to confirm and assess the theoretical findings, and an application is demonstrated on a set of chronic granulomatous disease data. Copyright © 2014 John Wiley & Sons, Ltd.     

Mechanisms and possible controls of the in utero Zika virus infection: Where is the Holy Grail?

Zika virus infection (ZVI) is a great concern for human health because it frequently causes fetal anomalies. Little is known about pathophysiology of ZVI because it has been regarded as a mild, no life‐threatening infection. However, the latest endemic in South and Central America took attention of perinatologists, microbiologists, and pathologists. Both in vivo and in vitro studies suggest neurotropic nature of Zika virus but do not clarify viral kinetics during vertical transmissions. In this review, we focus on the clinical and microbiological natures ZVI for pregnant women especially how placental barriers are broken down.     

Promoting safe infant feeding practices – the importance of structural,social and contextual factors in Southern Africa

There has been significant progress towards the goal of eliminating vertical transmission of HIV by 2015. However, a question that remains is how we can most effectively prevent late postnatal transmission of HIV through infant feeding. Guidelines published by the World Health Organization in 2010 have been widely adopted. These guidelines place strong emphasis on exclusive breastfeeding, in some countries over‐turning a prior emphasis on formula feeding. Where available, provision of antiretroviral treatment for HIV‐positive mothers or prophylaxis for infants offers additional protection against vertical transmission through infant feeding. However, merely changing guidelines is not sufficient to change practice, particularly with regard to culturally sanctioned forms of feeding, such as mixed feeding. This commentary highlights structural, social and contextual barriers to effective implementation of the guidelines and suggests ways to address some of these barriers.     

Sífilis y embarazo

Cases of syphilis during pregnancy and congenital syphilis have markedly decreased in developed countries. However, the same is not true of developing countries, especially in those with high HIV rates.We present a case of secondary syphilis in a woman with an 18-week pregnancy without prenatal care until diagnosis. Due to current migratory phenomena, cases such as this will probably increase in developed countries. We provide a review of the epidemiology, clinical features, diagnosis and treatment of syphilis during pregnancy.     

The Affective Dimension of Dyspnea Improves in a Dyspnea Self-Management Program With Exercise Training

ContextThe perception of dyspnea includes both sensory and affective dimensions that are shaped by emotions and psychological, social, and environmental experiences. Previous investigators have studied either measurement or strategies to decrease the affective dimension with laboratory-induced dyspnea. Few have reported the effect of a therapeutic clinical intervention on the affective dimension of dyspnea.Objectives1) To evaluate the effects of three different versions of a dyspnea self-management program (DM) on the affective dimension of dyspnea, measured by dyspnea-related anxiety (DA) and dyspnea-related distress (DD); and 2) to determine the stability of DA and DD over two baseline incremental treadmill tests (ITTs).MethodsParticipants with chronic obstructive pulmonary disease were randomly assigned to three 12 month DMs with varying doses of supervised exercise (DM, DM-Exposure, and DM-Training). The measurements of the affective dimension, DA and DD, were rated during ITTs on two baseline days and at two, six, and 12 months. Changes over time in DA and DD were analyzed using linear mixed-effects models.ResultsParticipants in the DM-Training group who received 24 nurse-coached exercise sessions had significantly greater reductions in DA and DD compared with those who had four exercise sessions (DM-Exposure) or only received a home-walking program (DM). Reductions in DA and DD in the DM-Training group were only maintained through six months. There were no significant differences in ratings of DA and DD at end between the two baseline ITTs.ConclusionThese findings provide initial support for the positive impact of a self-management program with nurse-coached exercise on the affective dimension of dyspnea. Further investigation of interventions that target the affective dimension in addition to the sensory dimension of dyspnea should be encouraged.     

Comparison of osseous healing after sagittal split ramus osteotomy and intraoral vertical ramus osteotomy

The sagittal split ramus osteotomy (SSRO) is generally associated with greater postoperative stability than the intraoral vertical ramus osteotomy (IVRO); however, it entails a risk of inferior alveolar nerve damage. In contrast, IVRO has the disadvantages of slow postoperative osseous healing and projection of the antegonial notch, but inferior alveolar nerve damage is believed to be less likely. The purposes of this study were to compare the osseous healing processes associated with SSRO and IVRO and to investigate changes in mandibular width after IVRO in 29 patients undergoing mandibular setback. On computed tomography images, osseous healing was similar in patients undergoing SSRO and IVRO at 1 year after surgery. Projection of the antegonial notch occurred after IVRO, but returned to the preoperative state within 1 year. The results of the study indicate that IVRO is equivalent to SSRO with regard to both bone healing and morphological recovery of the mandible.     

The influence of vertical dimension of occlusion changes on the electroencephalograms of complete denture wearers

PurposeThe present study was conducted to identify how changes in the vertical dimension of occlusion (VDO) affect the sensory perception and activity of the brain in complete denture wearers using an electroencephalogram (EEG).MethodsSubjects were 21 individuals wearing complete dentures who regularly visited the Division of Prosthodontics at Tsurumi University Dental Hospital for checkups (12 males and 9 females, average age: 76.6). Based on their original dentures, two duplicate dentures with different VDO (−3 mm and +5 mm) were fabricated. EEG activity and occlusal force were measured before and after gum chewing with each denture in all subjects. Negative indicator scores for psychological conditions and stable neuronal activity (Dα) were calculated using EEG data. Statistical analysis was performed using the Wilcoxon test to compare changes in the sensory perception, activity of the brain, and occlusal force (α = 0.05).ResultsAfter gum chewing with the +5-mm denture, a significant increase was observed in the negative indicator score (p < 0.05). No significant difference was found in the Dα values before and after gum chewing with any of the dentures (p > 0.05). A significant decrease was observed in the occlusal force between the original denture and the −3-mm denture (p < 0.05).ConclusionPsychological condition and occlusal force were influenced by immediate changes in the VDO of the complete denture.     

肝硬化患者的视网膜血管特征及其可能的诊断价值

目的 分析肝硬化患者的视网膜血管特征,并探讨视网膜血管参数在肝硬化中的诊断价值和眼底检查作为肝硬化筛查手段的可行性。方法 将90例确诊为肝硬化的患者和93名同期体检健康人员分别设为肝硬化组与对照组。使用眼底照相机和自动化图像分析系统对入组个体进行眼底图像采集和视网膜血管参数测量,包括视网膜血管管径、血管弯曲度、血管分支夹角和血管分形维数。比较2组各视网膜血管参数,采用受试者工作特征(ROC)曲线分析各视网膜参数单独和联合诊断肝硬化的效能。结果 与对照组相比,肝硬化组具有更宽的视网膜血管管径、更大的血管分支夹角和更小的血管分形维数(P均< 0.05)。视网膜血管管径、视网膜血管分形维数及两者联合诊断肝硬化的ROC曲线下面积分别为0.869(95%CI 0.820 ~ 0.919)、0.780(95%CI 0.713 ~ 0.847)和0.901(95%CI 0.860 ~ 0.942)。结论 肝硬化患者的视网膜血管系统发生了明显改变。视网膜血管管径和血管分形维数对肝硬化具有一定的诊断价值,诊断效能较佳,两者联合具有更高的诊断价值。眼底检查或可为肝硬化的便捷筛查和无创诊断带来更多的可能性。     

Short‐term changes in chewing efficiency and subjective evaluation in normal dentate subjects after insertion of oral appliances with an occlusal flat table

Oral appliances with an occlusal flat table are used as treatment dentures. However, the short‐term effect of insertion of such oral appliances on chewing has not been reported. This study aimed to determine whether experimental and continuous insertion of oral appliances with an occlusal flat table has an effect on chewing efficiency and Oral Health Impact Profile (OHIP) in healthy participants. Ten participants each in the oral‐appliance and control (no oral‐appliance insertion) groups attended six data collection sessions for 5 consecutive days. Participants answered the OHIP questionnaire and underwent the chewing efficiency test. For each parameter, intergroup differences were investigated in terms of change from baseline to immediately after oral‐appliance insertion (0 hour; P < .05) and from 0 hour to 24, 48, 72 and 96 hours after oral‐appliance insertion (P < .05). There were significant differences between groups in the degree of change in chewing efficiency and OHIP scores for functional limitation, physical pain, physical disability and handicap from baseline to 0 hour (all, P < .001); among these, only OHIP scores for functional limitation and physical pain demonstrated significant differences in degree of change between the two groups at 96 hours after appliance insertion (P = .477 and .275, respectively). Differences between the two groups in the degree of change in other parameters were not significant. Insertion of oral appliances caused a decrease in chewing efficiency and an increase in OHIP scores. Continuous insertion improved functional limitation and physical pain within 96 hours.     

Attentional Bias in specific symmetry and cleaning dimensions of obsessive-compulsive disorder

Attentional bias (AB) refers to increased allocation of attention on threat stimuli when compared to neutral stimuli. It is not clear if AB occurs in subjects with obsessive-compulsive disorder (OCD). We tested AB for symmetry and cleaning symptoms of OCD. Sixty-two patients with OCD and 40 healthy controls matched by gender, age and IQ, completed a computerized dot-probe task where two pictures (with symmetry or cleaning related content) were shown. The probe appeared in the location previously occupied by one of the pictures. Within-subjects linear mixed-effect models were used to investigate the effects of the factors: group (patients vs controls), OCD dimension (cleaning vs symmetry), task condition (neutral, congruent and incongruent), and the interaction among them. We also correlated AB scores with the clinical and demographic variables. No positive interaction resulted among the factors, but positive results were observed in group and condition, separately. Patients were significantly slower than controls (p-value = 0.014) (an effect that was accounted for by depression and anxiety symptoms and comorbidity) and the neutral condition was significantly faster when compared the other two conditions (congruent and incongruent, p-value = 0.013). No association was found between AB scores and clinical symptoms. There was no AB toward specific, content-related, stimuli in this sample of OCD patients.