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91.
The brains of pathogen-free autoimmune MRL/lpr, NZBWF1 and NZB mice were examined for central nervous system (CNS) inflammation in premoribund 8-week-old animals and at ages when active systemic lupus erythematosus (SLE) was present. CNS inflammation was observed only in MRL/lpr mice. Immunohistochemical studies of brains from young MRL/lpr mice found that infiltrates were composed primarily of CD4+ cells. Older MRL/lpr mice (22 and 26 weeks of age) had CD4+ cells predominantly, but CD8+ and B220+ cells were also present. Perivascular leakage of IgG was a prominent and unexpected finding in the MRL/lpr model. Congenic MRL/+ mice with late-onset autoimmunity had no inflammatory cells in brain tissue, and there was no perivascular staining with IgG or albumin. Our findings suggest that MRL/lpr mice are a useful model for studies of lupus-associated CNS inflammatory disease, and perivascular leakage may be a primary mechanism for entry of IgG into the brain.  相似文献   
92.
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.  相似文献   
93.
基于临床流程功能需求的生理监测仪配置评估   总被引:1,自引:0,他引:1  
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。  相似文献   
94.
The firing rate of locus coeruleus (LC) neurons in rat brain slices was increased reversibly by agents that either elevate intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or mimic its actions (e.g., forskolin, and activator of adenylate cyclase, 8-Br-cAMP, a membrane permeable analog of cAMP, and Ro20-1724, a preferential inhibitor of cAMP-phosphodiesterase). Intracellular recordings showed that 8-Br-cAMP and forskolin induce a depolarization of LC neurons, accompanied by a decrease in input resistance. The 8-Br-cAMP- and forskolin-elicited depolarization persisted in the presence of cobalt, a calcium channel blocker. Steady-state current-voltage curves revealed that in the voltage range of -50 to -120 mV, 8-Br-cAMP and forskolin induced an inward current, which did not reverse at the potassium equilibrium potential and could not be blocked by tetrodotoxin. Partial replacement of sodium with Tris or choline markedly reduced the depolarization elicited by 8-Br-cAMP. We conclude that 8-Br-cAMP and forskolin act through a common mechanism to increase the firing rate of locus coeruleus neurons by inducing a cAMP-activated inward current, carried out at least in part by sodium ions.  相似文献   
95.
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。  相似文献   
96.
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.  相似文献   
97.
耳源性脑疝25例,抢救成功者19例。采用单纯脑脓肿穿刺抽脓抢救脑疝6例,仅1例成功;开颅减压术抢救脑疝20例,18例抢救成功。本组临床实践和文献报道都说明耳源性脑疝一旦发生应即刻行开颅减压术,能卓有成效地抢救生命  相似文献   
98.
99.
Introduction Hypothalamic hamartomas are congenital malformations. Clinically, they can be asymptomatic, but they cause seizures, mental retardation and precocious puberty in many cases. Case report A 20-day-old boy with hypothalamic hamartoma and bilateral anophthalmia was presented. Except those, no other congenital anomaly was detected. Conclusion This is a rare case of hypothalamic hamartoma with bilateral anophthalmia. The mutations at SOX2 has an important role in the developing brain and eyes.  相似文献   
100.
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.  相似文献   
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