功能性矫治器在正畸矫治中运用的伦理思考

功能性矫治器是正畸临床中常用的一种矫治器，作者从口腔正畸学理论基础出发，探讨了功能性矫治器在正畸矫治作用中存在的伦理道德问题，主要有（1）不能正确的诊断、制定周密的矫治计划。（2）操作不规范、不细致、缺乏敬业精神。（3）态度简单，粗曝，缺乏与患者良好的交流。并提出解决方法（1）刻苦学习专业知识，不断提高诊疗水平及个人修养。（2）建立高度的道德责任感，以严谨的作风，规范的操作为病人服务。（3）尊重、善待青少年，建立良好的医患关系。     

Effects of different perfusates on functional parameters of isolated perfused dog kidneys.

BACKGROUND: The isolated perfused canine kidney has been established as a valid model for conducting both renal physiology and transplantation research. This model is of particular importance for developing new strategies to improve graft function after renal transplantation. In the present study, a newly developed method using isolated haemoperfused porcine kidneys was adapted for use in canine kidneys. In contrast to haemoperfusion, synthetic perfusion media can be standardized and can prevent the initiation of blood-mediated reperfusion reactions. Thus, an additional aim was to determine whether blood could be replaced by synthetic cell-free perfusion solutions. METHODS: Canine kidneys (n = 30) were harvested from donors euthanized in veterinary practices for causes unrelated to the present study. The kidneys were isolated and perfused with autologous blood or cell-free synthetic electrolyte buffer (Tyrode solution). During perfusion, we monitored renal perfusate flow (RPF), glomerular filtration rate (GFR), electrolyte and glucose reabsorption, oxygen consumption and urine concentration. RESULTS: Changes in perfusion medium did not affect the RPF. In contrast, GFR, urine concentration and oxygen consumption were significantly higher, whereas fractional excretion of sodium and glucose were significantly lower in blood- than in Tyrode-perfused kidneys. CONCLUSIONS: This system offers a simple model for studying whole-organ functional alterations after acute renal ischaemia. Renal function indicators were below values reported during in vivo physiological conditions. These functions were better conserved when kidneys were perfused with autologous blood than with Tyrode.     

130例二尖瓣置换术同期行三尖瓣成形术的方法及意义

目的 探讨二尖瓣置换术(MVR)同期行三尖瓣成形术(TVP)的手术方法和意义。方法 191例二尖瓣病变同时伴有功能性三尖瓣关闭不全(T1)的患者，其中130例于MVR手术同期行TVP。70例轻度TI中，有7例行Kay氏法二瓣化成形术，2例行DeVega瓣环成形术；中度和重度TI均同期行TVP：其中中度TI 92例，行DeVega瓣环成形术57例，Kay氏法二瓣化成形术33例，人工瓣环固定术2例；重度TI 29例，行DeVega瓣环成形术6例，人工瓣环固定术23例。结果 130例中死亡3例，127例康复出院。122例随访29～112月，发现32例有轻度或极轻度三尖瓣返流(TR)，7例中度TR，3例重度TR。结论二尖瓣病变同时伴有功能性TI的患者，在施行MVR同时，应行TVP，尤其是中重度TI更要积极处理。选择适当的手术方式，能有效纠正TI，阻止轻度TR加重，减少严重TR的发生率。     

现代医院手术室建设中的问题及动态研究

手术室是医学技术与工程技术结合的产物。随着医疗技术和新的手术工具的不断涌现,带动了手术量的迅猛上升。旧的手术室空间布局、实施标准、功能配置等方面已经无法满足新技术的应用要求,同时人们对手术环境和手术质量也提出了更高的标准。而今第四代手术室已开始步入我们的时代。洁净化、数字化和人性化则是其主要代表特征。本文分别从洁净手术室、数字化手术室和人性化手术室三个方面来探讨现代医院手术室建设中应注意的问题及动态研究。层流手术室已经是手术室建设不可逆转的发展趋势,除了按照《医院洁净手术部建筑技术规范》来建造外,其布局、人流、物流、质量监控等等都要进行合理的安排才能达到最优的手术环境。数字化手术室是将温度、湿度、压力、通风量、新风量等一切参数系统的由计算机来分配统筹,从而实现精确高效的手术管理。人性化手术室则是手术室建设的软件部分,是一种“以病人为中心”的服务理念,它打破了传统的生物医学模式,转变为生物—心理—社会模式,这是病人需求与市场竞争的必然选择。     

The intravascular contribution to fmri signal change: monte carlo modeling and diffusion-weighted studies in vivo

Understanding the relationship between fMRI signal changes and activated cortex is paramount to successful mapping of neuronal activity. To this end, the relative extravascular and intravascular contribution to fMRI signal change from capillaries (localized), venules (less localized) and macrovessels (remote, draining veins) must be determined. In this work, the authors assessed both the extravascular and intravascular contribution to blood oxygenation level-dependent gradient echo signal change at 1.5 T by using a Monte Carlo model for susceptibility-based contrast in conjunction with a physiological model for neuronal activation-induced changes in oxygenation and vascular volume fraction. The authors compared our Model results with experimental fMRI signal changes with and without velocity sensitization via bipolar gradients to null the intravascular signal. The model and experimental results are in agreement and suggest that the intravascular spins account for the majority of fMRI signal change on T₂^*-weighted images at 1.5 T.     

Functional mri of human brain activation combining high spatial and temporal resolution by a cine flash technique

Functional mapping of human brain activation has been accomplished at high spatial and temporal resolution (voxel size 4.9 μl, temporal increment 100 ms). The approach was based on oxygenation-sensitive long-echo time FLASH MRI sequences synchronized to multiply repeated cycles of visual stimulation in a CINE acquisition mode. This high temporal resolution revealed that stimulus-related signal intensity changes in human visual cortex display an initial latency followed by increases extending over several seconds. Furthermore, the temporal characteristics of the complete CINE MRI signal time course depended on the absolute and relative durations of activation and control periods and, for example, caused an apparent absence of a poststimulation “undershoot” phenomenon. Complementing hyperoxygenation due to rapid hemodynamic adjustments, these results suggest signal intensity modulation by enhanced oxygen consumption and concomitant deoxygenation during prolonged and/or repetitive stimulation.     

Functional dyspepsia: New insights into the pathophysiology

Abstract The pathogenesis of functional dyspepsia remains poorly understood. There is increasing evidence pointing to a predominant role of gastroduodenal visceral hypersensitivity in the pathogenesis, where patients have abnormally reduced gastric and small intestinal sensory thresholds. Motor abnormalities observed in subgroups of patients include delayed gastric emptying, antral hypomotility, gastric dysrhythmias, abnormal gastrointestinal reflexes and small intestinal dysmotility, but these may be secondary pheno nena. The central nervous system modifies peripheral visceral afferent pathways and, hente, psychological factors may possibly alter symptom status. Other putative mechanisms include Helicobacter pylori gastritis and gastric acid hypersecretion or sensitivity, but the role of these remain controversial.     

Responses of human primary sensorimotor and supplementary motor areas to internally triggered unilateral and simultaneous bilateral one‐digit movements. A high‐resolution EEG study

We modelled the responses of human primary sensorimotor areas and supplementary motor area to simple, self-initiated unilateral and simultaneous bilateral middle finger movements using a novel high-resolution electroencephalography technology. The results support the view that these cortical motor areas are involved in parallel and present similar activity in the preparation, initiation, and execution of the contralateral and bilateral movements. Furthermore, the left primary sensorimotor area (dominant hemisphere) appears to be activated more than the right primary sensorimotor area during the preparation and performance of the ipsilateral movements.     

In vivo 31P NMR studies of paraplegics' muscles activated by functional electrical stimulation

The bioenergetics of paralyzed muscles of spastic paraplegic patients under functional electrical stimulation (FES) was studied in vivo using ³¹P NMR. The protocol included rest, 3 min of induced tetanic isometric contraction through surface electrodes and 40 min of recovery. The continuous stimulation, the force recording and the ³¹P NMR measurements were sampled simultaneously inside the whole body imager. Normal values were found for the phosphorous metabolite ratios at rest. During contraction, prominent changes were detected including: a) accumulation of inorganic phosphate (P) accompanied by an unusually strong signal in the phosphomonoester (PME) region, b) phosphocreatine (PCr) decline, and c) a decrease in the intracellular pH. In the following recovery period the physiological state of the muscle was monitored and quantitated by ³¹P NMR. No metabolic and mechanical irreversible damage was detected in the paraplegics' muscles activated by FES under our experimental conditions.