下肢骨肿瘤带骨水泥的定制假体置换的无菌性松动

我们对１００１例骨肿瘤术后使用定制的假体置换，做了回顾性研究。股骨远侧假体４９３例，股骨近侧２６３例，胫骨近侧２４５例。无菌性松动是所见到的内植物失败的主要形式，７１个病人因带骨水泥髓内柄的无菌性松动而做了翻修术。一个病人其假体未发生无菌性松动达１２０个月的概率，在股骨近侧置换是９３．８％，股骨远侧是６７．４％，胫骨近侧是５８％。股骨远侧置换的病人中，手术时的年龄和骨切除的百分率，与无菌性松动的危险有关。有股骨远侧假体，股骨替换的百分率高的年轻病人，以后未发生无菌性松动的最少。在胫骨近侧置换组，骨去除的百分率有重要作用，但病人的年龄不重要。反之，股骨近侧置换后，年龄和骨去除的百分率都不是起作用的因素。这些发现的意义在有关机械因素方面做了讨论。     

白血病红细胞G6PD,PK和P5‘—N的观察

对白血病患者进行了红细胞Ｇ６ＰＤ、ＰＫ和Ｐ５’－Ｎ活性测定。治疗前急白患者红细胞Ｇ６ＰＤ、ＰＫ和Ｐ５’－Ｎ均低于正常对照组。缓解期急白患者红细胞Ｇ６ＰＤ、ＰＫ和Ｐ５’－Ｎ高于治疗前患者。慢粒患者红细胞Ｇ６ＰＤ和Ｐ５’－Ｎ与正常对照组无显著差异，而ＰＫ低于正常对照组。     

Perspectives on the Mechanism of Action of Electroconvulsive Therapy: Anticonvulsant, Peptidergic, c-fos Proto-oncogene Effects

Although the mechanism of action of electroconvulsive therapy (ECT) in affective illness has remained elusive, it is hoped that the consideration of mechanisms underlying the anticonvulsant efficacy of ECT will provide new insights into its biochemical and neuroanatomical substrates. In the amygdala-kindling model, electroconvulsive seizures (ECS) inhibit both the development and completed phases of kindled seizure evolution, and therefore, ECS is a more potent anticonvulsant modality than carbamazepine, which inhibits only completed kindled seizures. Carbamazepine is increasingly recognized for its acute and prophylactic efficacy in bipolar affective illness. Thus, comparing and contrasting effects of ECS and carbamazepine may provide insights into overlapping mechanisms of anticonvulsant and psychotropic action. Anticonvulsant effects of ECS have been most closely linked to endogenous opiate substances, perhaps acting on delta-opiate receptors, but a wide variety of other neurotransmitter and peptidergic effects are also potential candidates. Electroconvulsive seizures in mice activate the proto-oncogene c-fos in many discrete areas of brain, including a variety of limbic sites, the ventromedial nucleus of the hypothalamus, and the cerebellum. As such, c-fos induction may provide both an anatomical map of areas potentially activated by ECS and a potential mechanism for initiating a sequence of events that may be important to the mechanism of action of ECT. Although the anticonvulsant effects of ECT may ultimately prove to be separable from those mediating its therapeutic effects in affective illness, seizures and anticonvulsant effects provide easily measurable endpoints for preclinical and clinical studies. Given this clarity of effect, potential anticonvulsant mechanisms can rapidly be identified, enabling direct testing of whether or not these same mechanisms are also critical to the therapeutic effects of ECT in affective illness.     

Band-pass response properties of rat SI neurons

Rats typically employ 4- to 12-Hz "whisking" movements of their vibrissae during tactile exploration. The intentional sampling of signals in this frequency range suggests that neural processing of tactile information may be differentially engaged in this bandwidth. We examined action potential responses in rat primary somatosensory cortex (SI) to a range of frequencies of vibrissa motion. Single vibrissae were mechanically deflected with 5-s pulse trains at rates /=3 Hz. In contrast with this low-pass feature of the response, several other characteristics of the response revealed bandpass response properties. While average evoked response amplitudes measured 0-35 ms after stimulus onset typically decreased with increasing frequency, the later components of the response (>15 ms post stimulus) were augmented at frequencies between 3 and 10 Hz. Further, during the steady state, both rate and temporal measures of neural activity, measured as total spike rate or vector strength (a measure of temporal fidelity of spike timing across cycles), showed peak signal values at 5-10 Hz. A minimal biophysical network model of SI layer IV, consisting of an excitatory and inhibitory neuron and thalamocortical input, captured the spike rate and vector strength band-pass characteristics. Further analyses in which specific elements were selectively removed from the model suggest that slow inhibitory influences give rise to the band-pass peak in temporal precision, while thalamocortical adaptation can account for the band-pass peak in spike rate. The presence of these band-pass characteristics may be a general property of thalamocortical circuits that lead rodents to target this frequency range with their whisking behavior.