Modelling rhythmic function in a musician post-stroke

The aim of this study was to model the components of rhythmic function in a case (H.J.) of acquired rhythmic disturbance. H.J. is a right-handed, amateur male musician who acquired arrhythmia in the context of a global amusia after sustaining a right temporoparietal infarct. His rhythmic disturbance was analysed in relation to three independent components using an autoregressive extension of Wing and Kristofferson's model of rhythmic timing. This revealed preserved error-correction and motor implementation capacities, but a gross disturbance of H.J.'s central timing system ("cognitive clock"). It rendered him unable to generate a steady pulse, prevented adequate discrimination and reproduction of novel metrical rhythms, and partly contributed to bi-manual co-ordination difficulties in his instrumental performance. The findings are considered in relation to the essential components of the cognitive architecture of rhythmic function, and their respective cerebral lateralisation and localisation. Overall, the data suggested that the functioning of the right temporal auditory cortex is fundamental to 'keeping the beat' in music. The approach is presented as a new paradigm for future neuropsychological research examining rhythmic disturbances.     

Spike-timing-dependent synaptic plasticity - the long road towards understanding neuronal mechanisms of learning and memory

Depending on the precise temporal relationship between their spiking activities, connections between neurons could be modified in opposite directions. Although the functional implications of this spike-timing-dependent plasticity are not clear, several theoretical studies have indicated that it could underlie important effects such as sequence learning, predictive learning and balancing excitation and inhibition. To explore fully this novel form of synaptic plasticity, it is crucial to understand how the modification builds up over the consecutive spikes of presynaptic and postsynaptic neurons. In the absence of solid data, many theorists assumed a linear summation model. However, recent experiments specifically devised to study this issue have demonstrated that the effects of the consecutive spikes on the overall modification steadily decline, indicating strong non-linearities in the corresponding learning rules.     

手术治疗老年急性胆囊炎64例临床分析

目的：探讨老年急性胆囊炎手术时机的选择及手术特点。方法：回顾性分析64例老年急性胆囊炎（其中急性结石性胆囊炎59例，非结石性胆囊炎5例）的临床资料，行单纯性胆囊切除术55例，胆囊切除＋胆总管探查T管引流术5例，胆囊造瘘1例，胆囊大部切除3例。结果：术后发生并发症17例（26．6％），其中并发切口感染8例，肺部感染5例，切口裂开2例，切口疝1例，胆道损伤1例。64例患者中，63例痊愈，1例死亡。结论：老年急性胆囊炎无手术禁忌时应及早行手术治疗。     

增生性糖尿病视网膜病变的手术治疗观察

目的探讨玻璃体视网膜手术对增生性糖尿病视网膜病变的治疗效果。方法回顾性分析增生性糖尿病视网膜病变（PDR）12眼。经标准的玻璃体视网膜手术治疗后的临床观察，对术前术后视力、于术并发症等进行重点观察分析。结果术后视力提高至0．1及以上者9眼（75．00％），数指～0．1者2眼（16．67％），未提高1眼（8．33％）。结论玻璃体视网膜手术可以部分改善PDR的视功能，建议玻璃体积血后应早期进行手术治疗。     

外伤性白内障人工晶状体植入术探讨

目的探讨外伤性白内障联合人工晶状体植入术手术时机的选择。方法58例(59眼)外伤性白内障,根据其致伤情况、角膜及眼内组织的损伤程度不同,选择不同的手术方法植入前房型或后房型人工晶状体。结果术后均无严重并发症,术后视力0.3~1.0者36眼,占61%。结论正确把握外伤性白内障手术时机和术式选择,可使外伤性白内障恢复较理想的视力。     

大鼠弥漫性轴索损伤后一氧化氮合酶表达的时间规律性研究

目的观察大鼠弥漫性轴索损伤（DAI）后不同时间一氧化氮合酶（NOS）在脑皮质、海马及脑干的表达规律，进一步阐明脑损伤后继发性轴索损伤的发生机制。方法参照Marmarou的方法复制大鼠DAI模型，经Gless染色对脑白质、胼胝体、脑干轴索损伤进行形态学观察，应用免疫组织化学方法对不同时间脑皮质、海马、脑干NOS表达规律进行定量观察。结果经Gless染色在伤后0．5h可见轴索损伤的形态学变化．12h见明显的轴索收缩球，1～3d收缩球明显增多，3d后出现恢复期变化，NOS表达在伤后1h开始增加，12h～1d达到高峰，以后逐渐下降，至10d仍较基础表达水平为高。结论轴索损伤的形态学变化与伤后不同时间NOS表达的强度有明显的相关关系，表明DAI后NOS参与了继发性DAI的形成过程．为法医学对DAI损伤时间的推断提供新的参考指标。     

外伤性白内障手术时机及手术方式的探讨

目的:探讨外伤性白内障人工晶状体(IOL)植入术的效果及术式选择.方法:65例(65眼)外伤性白内障,一期植入后房型IOL 39例,手术距外伤时间3～24h;二期植入后房型IOL 26例,手术距外伤时间2个月～10年.结果:一期植入者脱盲率94.87%,脱残率66.67%;二期植入者脱盲率96.15%,脱残率69.23%,两者间无显著性差异(P＞0.05).术后并发症IOL前膜、后囊混浊,两者间存在显著性差异(P＜0.05).两种手术均无严重并发症.结论:对于外伤性白内障患者,只要掌握好适应证,应努力争取行一期植入术.     

Long-term results of pre-emptive liver transplantation in primary hyperoxaluria type 1

In primary hyperoxaluria type 1 (PH 1), deficiency or mistargeting of hepatic alanine glyoxylate aminotransferase (AGT) results in over-production of oxalate and hyperoxaluria, leading to nephrocalcinosis and development of end-stage renal disease (ESRD) in the majority of patients. Renal transplantation (Tx) alone carries a high risk of disease recurrence as the metabolic defect is not cured. Therefore, combined liver/kidney Tx is recommended for patients with ESRD. An alternative approach is to cure PH 1 by pre-emptive isolated liver Tx (PLTx) before ESRD has occurred, but this approach has been carried out only occasionally and there are no uniformly accepted recommendations concerning the timing of this procedure. We report follow-up 3-5.7 yr after performing successful PLTx in four children (at the age of 3-9 yrs) with PH 1 prior to the occurrence of ESRD (glomerular filtration rate [GFR] range 27-98 mL/min/1.73 m2). There was no mortality or long-term morbidity associated with the Tx procedure. Plasma and urinary oxalate levels normalized rapidly within 4 weeks, and renal function did not deteriorate under immunosuppression, even in one patient with advanced chronic renal failure (GFR 27 mL/min/1.73 m2) who showed a stable course for more than 5.7 yrs. Although treatment must be individualized in this severe metabolic disorder, and PLTx has to be regarded as an invasive procedure, we consider that PLTx should be offered and considered early in the course of PH 1. PLTx cures the metabolic defect in PH 1 and can help to prevent, or at least delay, the progression to ESRD and systemic oxalosis.     

The growth-restricted fetus: risk of mortality by each additional week of expectant management

Objective: To compare fetal/infant mortality risk associated with each additional week of expectant management with the infant mortality risk of immediate delivery in growth-restricted pregnancies.

Methods: A retrospective cohort study was conducted of singleton, nonanomalous pregnancies from the 2005–2008 California Birth Registry comparing pregnancies affected and unaffected by growth restriction, defined using birth weights as a proxy for fetal growth restriction (FGR). Birth weights were subdivided as greater than the 90th percentile, between the 10th percentile and 90th percentile, and less than the 10th percentile. Cases greater than the 90th percentile were excluded from analysis. Cases less than the 10th percentile were considered to have FGR and were further subcategorized into <10th percentile, <5th percentile, and <3rd percentile. We compared the risk of infant death at each gestational age week against a composite risk representing the mortality risk of one additional week of expectant management.

Results: We identified 1,641,000 births, of which 110,748 (6.7%) were less than 10th percentile. The risk of stillbirth increased with gestational age with the risk of stillbirth at each week of gestation inversely proportional to growth percentile. The risks of fetal and infant mortality with expectant management outweighed the risk of infant death for all FGR categories analyzed beginning at 38 weeks. However, the absolute risks differed by growth percentiles, with the highest risks of infant death and stillbirth in the <3rd percentile cohort. At 39 weeks, absolute risks were low, although the number needed to deliver to prevent 1 death ranged from 413 for <3rd percentile to 2667 in unaffected pregnancies.

Conclusion: At 38 weeks, the mortality risk of expectant management for one additional week exceeds the risk of delivery across all growth-restricted cohorts, despite variation in absolute risk by degree of growth restriction.