Engineering Analysis of Tricuspid Annular Dynamics in the Beating Ovine Heart

Functional tricuspid regurgitation is a significant source of morbidity and mortality in the US. Furthermore, treatment of functional tricuspid regurgitation is suboptimal with significant recurrence rates, which may, at least in part, be due to our limited knowledge of the relationship between valvular shape and function. Here we study the dynamics of the healthy in vivo ovine tricuspid annulus to improve our understanding of normal annular deformations throughout the cardiac cycle. To this end, we determine both clinical as well as engineering metrics of in vivo annular dynamics based on sonomicrometry crystals surgically attached to the annulus. We confirm that the tricuspid annulus undergoes large dynamic changes in area, perimeter, height, and eccentricity throughout the cardiac cycle. This deformation may be described as asymmetric in-plane motion of the annulus with minor out-of-plane motion. In addition, we employ strain and curvature to provide mechanistic insight into the origin of this deformation. Specifically, we find that strain and curvature vary considerable across the annulus with highly localized minima and maxima resulting in aforementioned configurational changes throughout the cardiac cycle. It is our hope that these data provide valuable information for clinicians and engineers alike and ultimately help us improve treatment of functional tricuspid regurgitation.     

认知矫正治疗对慢性精神分裂症患者临床症状和社会功能的影响

目的:观察认知矫正治疗对慢性精神分裂症患者临床症状和社会功能的改善作用。方法:选择2003-01/08在北京回龙观医院住院的慢性精神分裂症患者104例。均符合CCMD-Ⅲ及DSM-Ⅳ关于精神分裂症诊断标准;年龄25～55岁;病程≥2年;病情稳定,处于迁延、残留或部分缓解状态;药物治疗状况稳定,近期无换药打算;纳入对象或家属同意入组并签署知情同意书。应用随机数字表法将患者分认知矫正治疗组和对照组,每组52例。在相近药物治疗的基础上,认知矫正治疗组以Ann Delahunty和Rodney Morice等制定的神经认知矫正手册(汉化)为治疗工具,在治疗师的指导下进行认知作业练习,内容包括认知灵活性、工作记忆、计划执行功能3大功能模块。对照组予以相同时间的工娱治疗,主要包括有治疗师指导的操作性音乐治疗和舞蹈治疗。治疗前后两组患者分别进行PANSS、住院精神患者社会功能缺陷量表和护士观察量表的评定。结果:实验共纳入慢性精神分裂症患者104例,认知矫正治疗组44例,对照组46例进入结果分析,14例脱落。①治疗前后两组患者PANSS量表总分以及阴性症状量表、复合量表、一般精神病理量表、反应缺乏量表4个分量表的评分均有下降,组内比较差异有显著性意义(t=2.12～4.59,P<0.05);减分情况在两组间差异不明显(P>0.05)。②两组患者的社会功能缺陷量表总分在治疗后均有下降,与治疗前比较,差异有显著性意义(t=3.89,2.04,P<0.05);两组间比较,差异无显著性意义(P>0.05)。认知矫正治疗组治疗后护士观察量表的总病情以及总消极、迟滞2个分量表评分下降,与治疗前比较差异有显著性意义(t=1.49,1.19,2.81,P<0.05);其中迟滞项的减分在两组间比较,差异具有显著性意义(F=4.97,P<0.05)。③社会功能量表的改善与词语流畅性的改善呈正相关(R2=0.36,P<0.05),护士观察量表中总病情与积极两项评分的改善也与言语流畅性测验的改善正相关(R2=0.37,0.34,P<0.05)。结论:认知矫正治疗能在一定程度上改善精神分裂症患者的社会功能,并与部分认知功能的改善相关,但对临床症状无明显改善作用。     

Baroreflexsensitivität und chronischer Schmerz

The interaction of cardiovascular dynamics and pain perception is an important component of intrinsic pain regulation. In healthy subjects acute pain stimuli cause increased sympathetic arousal and increased mean arterial pressure. Arterial baroreceptors sense phasic blood pressure changes and relay the information to the lower brainstem via the dorsomedial nucleus tractus solitarius (dmNTS). Projections in the brainstem and also higher cortical areas result in elevation of blood pressure as part of the autonomic nervous system as well as modulation of sleep, anxiety and pain. In healthy subjects there is an inverse relationship between blood pressure and pain sensitivity but this relationship is impaired in chronic pain patients. Persistent stress, pain behavior and classical and operant conditioning mechanisms reduce baroreflex sensitivity (BRS) and dmNTS activity in a subgroup of patients. This leads to a decrease of autonomic regulatory function as well as reduced pain inhibition. Importantly, baroreflex function can be modulated by cognitive and affective processes. This article reviews the role of the baroreflex arc as a possible crucial factor in the development and maintenance of chronic pain. The importance of learning mechanisms is described. Mechanism-based individualized treatment approaches for patients with hypertensive stress reactivity are also critically discussed.     

Retreatment of hepatitis C patients with pegylated interferon combined with ribavirin in non-responders to interferon plus ribavirin. Is it different in real life?

Background  

More than 50% of hepatitis C viruses (HCV)-infected patients do not respond to the classical Interferon (IFN)/Ribavirin (RBV) combination therapy. The aim of this study was to evaluate the efficacy of retreatment with Peg-Interferon alpha-2b (PEG-IFN alpha-2b) plus RBV, in patients with HCV, genotypes 1 or 3, who were non-responders to the previous standard treatment with IFN/RBV.     

Preterm neonatal cardiovascular instability: Does understanding the fetus help evaluate the newborn?

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