Singularities explained: Response to Klein.

Klein [Klein, A. S. (2006). Separating transducer nonlinearities and multiplicative noise in contrast discrimination. Vision Research, 46, 4279-4293] questions the existence of intrinsic singularities in two-alternative force-choice (2AFC) Signal Detection Theory (SDT) models, suggesting that the singularities found in Katkov et al. [Katkov, M., Tsodyks, M., & Sagi, D. (2006a). Singularities in the inverse modeling of 2AFC contrast discrimination data. Vision Research, 46, 259-266; Katkov, M., Tsodyks, M., & Sagi, D. (2006b). Analysis of two-alternative force-choice Signal Detection Theory model. Journal of Mathematical Psychology, 50, 411-420] are due to discarding higher order terms in the Taylor expansion of d' and/or limited to steep psychometric functions. Here we provide some simple intuitive examples that illustrate the results described in Katkov et al. (2006a, 2006b). We show, for the constant noise model, that singularities exist when exact values of d' are computed and that the singularities are not limited to steep psychometric functions. In these cases the disambiguation of the different models requires millions of trials.     

不同分级肝硬化患者血清甲状腺素水平的意义

目的探讨肝硬化患者血清中甲状腺素水平的变化与肝硬化病变程度及其临床实验室检查之间的相关性。方法用放免法测定肝硬化患者血清FT3、FT4、PC-Ⅲ、Ⅳ-C、LN及HA，并按Child—Pugh方法将肝功能分为A、B、C三级。结果随着肝硬化病变程度的加重，血清肝纤维化指标逐渐增高，甲状腺素呈下降趋势，同时血清甲状腺素水平与肝硬化的低蛋白血症、腹水及凝血酶原时间密切相关。结论肝硬化患者体内存在不同程度的甲状腺素水平紊乱，紊乱程度与肝功能受损程度有明显相关性，联合检测血清FT3、FT4、PC-Ⅲ、Ⅳ—C、LN及HA对估计肝硬化病变程度及判断预后有十分重要的临床价值。     

基于临床流程功能需求的生理监测仪配置评估

病人生理监测仪是临床医学的主要仪器之一，由于所涉及的技术流程定位不同，功能需求也就不同，其功能配置也应有所不同。本文从分解分析生理监测仪相关应用领域的技术定位功能需求出发，讨论卫生技术装备管理的功能配置评估。     

XD—1型微电脑程序刺激器在心血管病中的临床应用

本文应用XD—Ⅰ型微电脑程序刺激器检查26例患者,在窦房结功能检查中测定了窦房结恢复时间、窦房传导时间及固有心率;在房室传导功能的估计中测定了文氏点,2∶1阻滞点及房室结的有效不应期;在室上性心动过速中测定了旁路不应期,房室结双通道,折返区及折返性心动过速区;还进行了心脏负荷试验及右束支不应期等方面的测定。并就其方法,判断标准及临床意义等分别作了讨论。     

Behavioral and biochemical evidence for a long-lasting decrease in GABAergic function elicited by chronic administration of FG 7142

Chronic treatment with the beta-carboline derivative FG 7142 (15 mg/kg i.p. twice a day for 10 consecutive days) produced a long-lasting enhancement of shock-induced suppression of drinking in rats, without affecting unpunished behaviour. This proconflict effect was observed up to 15 days after withdrawal from FG 7142. A significant sensitization to seizures induced by isoniazid, a drug known to inhibit GABAergic transmission, was also found to occur after long-term (25 days) withdrawal. Moreover, the density of low-affinity GABA receptors was decreased by 30% in the cerebral cortex of rats repeatedly injected with FG 7142 at 5 and 15 days after withdrawal. The capacity of high-affinity GABA receptors, as well as the apparent dissociation constants for both high- and low-affinity GABA receptors were unchanged. Similar modifications in [3H]GABA binding were also observed in the cerebellum. The enhancement of punishment suppressed behaviour, the sensitization to isoniazid-induced convulsions and the decrease in the density of low-affinity GABA receptors suggest that chronic administration of FG 7142 induces a persistent down-regulation of GABAergic transmission in the central nervous system.     

复方金荞麦颗粒治疗肺癌1000例临床疗效观察

目的 总结复方金荞麦颗粒治疗肺癌的疗效。方法 对1000例各种类型的肺癌患者采用复方金荞麦颗粒5g，3次·d^-1 口服，同时辅以中药汤剂治疗，3mo为1疗程，病情稳定后逐渐减量维持。结果本组1000例患者经3mo～15a以上治疗，基本治愈181例（18．1％），显效518例（51．8％），有效204例（20．4％），无效97例（9．7％），总有效率为90．3％。结论 复方金荞麦颗粒为抗肿瘤的纯中药制剂，具有明显抑制肿瘤细胞生长、增强免疫功能、提高患者生存质量等功效，尤其是对失去手术治疗机会、不能接受化疗和放疗的肺癌患者具有较好疗效。     

Heart rate response to breathing: dependency upon breathing pattern

Summary. Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1·6 ± 0·5 s and in 3·6 ± 1·4 s in response to inspiration and expiration, respectively (P < 0·01). The slowest heart rate was reached in 4·8± 1·0 s and in 7·6± 1·9 s in response to inspiration and expiration, respectively (P < 0·01). Following this biphasic change the heart rate returned to a steady level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21·7 ± 7·3 beats per minute) than in response to expiration (12·0±7·3 beats per minute; P < 0·01). Periodic changes in lung volume were performed with frequencies from 3·0 to 12·0 respirations per minute (r.p.m.). The changes in heart rate showed a constant amplitude in the frequency range below 5·5 r.p.m. Maximal heart rate changes were found at frequencies of 5·5 to 7·0 r.p.m. Changes in heart rate decreased in a linear manner on a log-log scale in the frequency range above 7·0 r.p.m. The relation between frequency and changes in heart rate is explained by interference between the transient changes in heart rate induced both by inspiration and by expiration. It is concluded that if heart rate changes in response to periodic changes in lung volume are to be used as a measure of vagal function a number of factors have to be taken into consideration and to simplify the analysis of heart rate responses to breathing we recommend, instead, the use of the transient changes in heart rate induced by stepwise changes in lung volume.     

Adrenocortical responsiveness in neonates weaned from the ventilator with dexamethasone

Adrenocortical responsiveness was assessed in eight very low birthweight neonates who had bronchopulmonary dysplasia and had been weaned from mechanical ventilation using dexamethasone. Three of the eight infants did not respond to ACTH stimulation during the first week after cessation of dexamethasone, but all three responded normally when retested at least 1 month later. The present authors have thus demonstrated that some infants have at least temporary adrenocortical unresponsiveness after prolonged courses of glucocorticoid therapy, and suggest that adrenocortical function should be assessed in all infants who are weaned from mechanical ventilation using dexamethasone.     

经皮椎体成形术中骨水泥对老年骨质疏松症患者凝血功能的影响

目的 观察经皮椎体成形术(PVP)中骨水泥对老年骨质疏松症患者凝血功能的影响.方法 于椎弓根穿刺前10 min、注入骨水泥后1、20 min、2 h分别抽血检测11例患者的凝血功能相关指标,包括血浆凝血酶原时间(PT)、活化的部分凝血酶原时间(APTT)、血浆纤维蛋白原(FIB)和鱼精蛋白副凝固实验(3P实验),并汇总数据进行统计学分析.结果 PVP中骨水泥注入后20 min,PT缩短、FIB增高、3P实验阳性率升高(P<0.05),骨水泥注入2 h后基本恢复至注入前水平.除1例患者PTA术后2 h稍高于正常值(126%),其余患者各个时间点的各项指标均在正常参考值范围内.结论 PVP术中注入骨水泥对于凝血功能正常的患者基本安全,但在注入后会产生一过性轻微的高凝倾向.