Kinetic modeling of PET-FDG in the brain without blood sampling

The aim in this work is to report a new method to calculate parametric images from a single scan acquisition with positron emission tomography (PET) and fluorodeoxyglucose (FDG) in the human brain without blood sampling. It is usually practical for research or clinical purposes to inject the patient in an isolated room and to start the PET acquisition only for some 10–20 min, about 30 min after FDG injection. In order to calculate the cerebral metabolic rates for glucose (CMRG), usually several blood samples are required. The proposed method considers the relation between the uptake of the tracer in the cerebellum as a reference tissue and the population based input curve. Similar results were obtained for CMRG values with the present method in comparison to the usual autoradiographic and the non-linear least squares fitting of regions of interest.     

脂蛋白脂酶Hind Ⅲ基因多态性与动脉硬化性脑梗死的关系

目的研究脂蛋白脂酶HindⅢ基因多态性与动脉硬化性脑梗死发病的关系及其对血脂、颈动脉斑块的影响。方法选择166例动脉硬化性脑梗死患者，采用聚合酶链反应-限制性片段长度多态性分析检测脂蛋白脂酶的HindⅢ基因多态性，颈动脉超声多普勒检查颈总动脉内膜中层厚度和颈动脉斑块，并与72名健康对照比较。结果在脑梗死组中H＋H＋基因型频率和H＋等位基因频率明显高于对照组（OR=2．267，P=0．004；OR=1．903，P=0．004），而血脂水平、颈总动脉内膜中层厚度、颈动脉斑块分级与对照组比较差异无统计学意义。结论脂蛋白脂酶的HindⅢ基因多态性与脑梗死的关系密切，H＋H＋基因型可能是脑梗死的危险因素。     

丹参对持续癫痫幼鼠脑损伤保护作用的实验研究

目的 探讨丹参对持续癫痫发作诱发幼鼠脑神经元损伤是否具有保护作用。方法 皮下及腹腔注射贝美格针诱发健康幼龄鼠癫痫持续状态发作。光镜下观察神经元病变情况；电镜观察海马神经元超微结构的改变。结果 持续癫痴组幼鼠脑组织光镜下可见明显的神经元病变。电镜下可见海马区神经元的超微结构病变。丹参治疗组神经元病变均轻于持续癫痴组；而正常对照组未见类似病变。结论 丹参在组织、细胞和亚细胞水平对持续癫病幼鼠脑神经元损伤具有一定的保护作用，为临床有效防治小儿惊厥性脑损伤提供了可靠的实验依据。     

Observations on the efficacy of combined acupuncture and medicine in Treating 50 cases of pseudobulbar paralysis

目的：观察针药结合治疗假性延髓麻痹的疗效。方法：采用完全随机抽样法分为针刺组50例，对照组48例。针刺组在西医治疗的同时，应用针刺进行综合治疗；对照组单纯接受西医药物治疗。结果：针刺组有效率为92．0％，对照组为62．5％。两组疗效差异具有非常显著性意义（P〈0．01）。结论：针药结合治疗假性延髓麻痹效果明显优于单纯西药治疗。     

多层螺旋CT灌注成像在颅脑系统疾病中的应用研究

随着多层螺旋CT的推广使用,使以脑血流动力学研究为目的的多层螺旋CT脑灌注成像(MSCT perfusion imaging)逐渐变为现实,为综合应用CT扫描技术提供了条件,为临床提供了一种全新的、极具潜力的、适用面广的影像检查新技术。一、CT脑灌注成像理论基础1.脑灌注成像理论的形成:在198     

Nestin expression persists in astrocytes of organotypic slice cultures from rat cortex

Nestin is an intermediate filament protein typical for neural precursor cells that is down-regulated in the post-natal rodent brain. Re-expression of nestin has been observed in reactive astrocytes after injury. In this study, organotypic slice cultures from rat cortex were examined for expression of nestin and glial fibrillary acidic protein between 2 and 8 weeks in culture. Immunoreactivity for nestin and glial fibrillary acidic protein was seen in astrocytes which persisted throughout the observation period. Immunofluorescence double labeling showed widespread co-localization of nestin and glial fibrillary acidic protein. Image analysis revealed that levels of nestin-immunoreactivity plateaued after 5 weeks in culture. By comparison nestin immunoreactivity was absent from glial cells of the cortex in mature rats. These immunohistochemical findings of a persistent expression of nestin in glial cells of organotypic slice culture of the rat cortex indicate a different time course of glial maturation in vitro. This difference could be related to the altered trophic stimulation in vitro; differences in neuronal maturation, activity or survival; slow degeneration of the vasculature; or intrinsic properties of astrocytes.     

Localized proton magnetic resonance spectroscopy of a cerebellar tumor in a two-year-old child

Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year-old girl. The clinical signs were a mild head tilt and neck pain. Magnetic resonance imaging (MRI) revealed a lesion in the right hemisphere of the cerebellum, but its nature remained obscure. In this lesion quantitative determinations of cerebral metabolites by fully relaxed, short-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, together with the MRI morphology, suggested a brain tumor. The diagnosis was established by neurosurgical exploration and total extirpation of the tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs.     

胚胎NA能神经元移植对鼠点燃癫痫发作程度的影响

目的：明确胚胎NA能神经元移植对点燃癫痫发作严重程度的影响。方法：以Wistar大鼠为研究对象，按移植物的性质分为NA移植组、移植对照组和还对照组。首先定期电刺激杏仁核制备电点燃癫痫模型，再用立体定向技术向各组动物的海马移植相应的移植物，移植后观察癫痫的电生理和行为学指标（杏仁核后放电阈值、持续时间、癫痫行为级别、癫痫持续时间）变化情况，TH免疫组织化学染色了解移植物存活情况。结果：经统计学处理，移植前后各指标无显著性差异（P＞0．05）。结论：胚胎NA能神经元移植对点燃癫痫的发作严重程度无抑制作用。     

Tumor induction by ras and myc oncogenes in fetal and neonatal brain: modulating effects of developmental stage and retroviral dose

Introduction into fetal rat brain cells of a replication-defective retroviral vector harboring v-Ha-ras and v-gag-myc rapidly causes the induction of highly malignant undifferentiated neuroectodermal tumors following transplantation into the brains of syngeneic hosts [Wiestler, et al. (1992) Cancer Res. 52: 3760–3767]. In the present study, we have investigated the modulating effect of the developmental stage of neural target cells and of the dose of the retroviral vector used in the grafting experiments. Exposure of fetal cells from embryonic day (E)12 or E14 produced a 100% incidence of malignant neuroectodermal tumors which led to the death of recipient animals after a median latency period of 32 days. A 100-fold reduction of the virus dose from 2.062×10⁶ to 2.062×10⁴ focus-forming units/ml resulted in a lower tumor incidence of 25%. Of six neural grafts exposed to v-Ha-ras and v-myc at E16, only one showed evidence of tumorigenesis (low-grade astrocytoma and hemangioma). All other transplants were morphologically normal for observation periods of 26 weeks, indicating a marked loss of transforming activity of ras and myc in more advanced stages of brain development. In retrovirus-exposed donor cells which caused the development of neural tumors in recipient rats, malignant transformation was also evident during culture in vitro, usually after 9–12 days. Oncogene complementation was also studied in the newborn rat brain. After microinjection of the retroviral vector into the brain at postnatal day (P)0, P1 and P3, 5 out of 20 animals (25%) developed a total of seven brain tumors. Histopathologically, three of these neoplasms were malignant neuroectodermal tumors which, in contrast to those induced in fetal brain transplants showed evidence of focal glial and/or neuronal differentiation. In addition, we observed one oligodendroglioma, two hemangiomas and a malignant hemangioendothelioma. These data indicate that neural precursor cells and endothelia of the rat brain represent the major target cells for the complementary action of ras and myc and that the use of target cells from later developmental stages (E16 and postnatal) leads to the induction of both primitive and more differentiated neoplasms.These studies were supported by the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich (Erwin Schrödinger fellowship, JO501-MED), by the Swiss National Science Foundation and by the Cancer League of the Kanton of Zürich