Continuously moving table 3D MRI with lateral frequency-encoding direction.

A method is presented for 3D MRI in an extended field of view (FOV) based on continuous motion of the patient table and an efficient acquisition scheme. A gradient-echo MR pulse sequence is applied with lateral (left-right (L/R)) frequency-encoding direction and slab selection along the direction of motion. Compensation for the table motion is achieved by a combination of slab tracking and data alignment in hybrid space. The method allows fast k-space coverage to be achieved, especially when a short sampling FOV is chosen along the direction of table motion, as is desirable for good image quality. The method can be incorporated into different acquisitions schemes, including segmented k-space scanning, which allows for contrast variation with the use of magnetization preparation. Head-to-toe images of volunteers were obtained with good quality using 3D spoiled gradient-echo sequences. As an example of magnetization-prepared imaging, fat/water separated images were acquired using chemical shift selective (CHESS) presaturation pulses.     

皮质发育障碍模型的建立及其致痫敏感性的研究

目的:建立皮质发育障碍模型,探讨皮质发育障碍模型的敏感性。方法:在SD大鼠孕17d腹腔注入1,3-二氯乙烯-亚硝基脲(BCNU)制作皮质发育障碍模型;Nissl染色观察P60d仔鼠病理变化;选取P60d雄性仔鼠,腹腔注射氯化锂-毛果芸香碱,分别比较两组大鼠癫发生的潜伏期、持续状态时间和死亡率。结果:同龄仔鼠脑组织湿重实验组比对照组显著减轻(P<0.01);Nissl染色显示皮质变薄、皮质层次紊乱、海马区域异位细胞异常聚集;有皮质发育障碍的仔鼠注射氯化锂-毛果芸香碱后,癫发生的潜伏期显著缩短(P<0.01),癫持续状态时间延长(P<0.01),死亡率显著升高(P<0.05)。结论:BCNU致皮质发育障碍模型具有癫易感性。     

直肠癌切除前后腹腔冲洗液脱落细胞学对比研究

目的研究直肠癌术中腹腔多次冲洗，对于降低患者腹腔内脱落癌细胞阳性率的临床意义。方法对63例直肠癌患者术中腹腔冲洗分6次进行，肿瘤切除前3次，切除后3次；将6次腹腔冲洗液行常规病理学涂片细胞学检查结果进行对比。结果肿瘤切除前，全组患者腹腔冲洗液脱落癌细胞均呈阳性表达。肿瘤切除后第1次腹腔冲洗液脱落癌细胞阳性40例，第2次阳性33例，第3次阳性13例。肿瘤切除后第1次冲洗液的脱落癌细胞阳性结果与切除后第2次冲洗液阳性结果比较，P〉0.05，差异无统计学意义；但第3次冲洗液的脱落癌细胞阳性结果与第2次比较，P〈0.01，差异有统计学意义。结论对直肠癌患者进行术中多次腹腔冲洗可降低腹腔内脱落癌细胞的阳性率。     

Inherited focal, episodic neuropathies

Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or “sausage-like” formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found.     

三磷酸腺苷结合盒运转体A1与颈动脉粥样硬化斑块的关系

目的 探讨三磷酸腺苷结合盒运转体A1(ATP binding cassette transporter A1,ABCA1)在人颈动脉粥样硬化斑块中的表达变化及作用机制.方法 收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本(对照组),采用RT-PCR测定ABCA1 mRNA和视黄酸X受体α(RXRα)mRNA表达水平,并采用Western Blot检测ABCA1及RXRα的蛋白表达水平.24例人颈动脉粥样硬化斑块标本按病理分级,比较病理组织为Ⅲ级和Ⅰ级动脉粥样硬化组织间ABCA1 mRNA、RXRαmRNA表达水平及蛋白表达水平.结果 颈动脉粥样硬化斑块组的ABCA1 mRNA(0.79±0.04)和RXRα mRNA(0.73±0.04)表达与对照组相比上调,差异有统计学意义(P＜0.05);ABCA1 mRNA与RXRα mRNA增加水平相关(P＜0.05);颈动脉粥样硬化斑块的ABCA1蛋白表达(0.22±0.03)下调水平与对照组(0.53±0.03)相比差异有统计学意义(P＜0.05);Ⅲ级和Ⅰ级动脉硬化斑块ABCA1mRNA、RXRα mRNA及蛋白表达水平差异有统计学意义(P＜0.05).结论 ABCA1及RXRα蛋白表达水平下调可能是进展性动脉粥样硬化损害的关键因素.     

Spinocerebellar ataxia types 2 and 3 segregating simultaneously in a single family.

Spinocerebellar ataxia (SCA) types 2 and 3 are autosomal-dominant neurodegenerative disorders caused by mutations in two different genes. We identified mutations for SCA2 and SCA3 segregating simultaneously in a single Brazilian family. The index patient had SCA2, whereas her two second-degree cousins had SCA3. Disease was more rapidly progressive in the SCA2 patient, who presented severe brainstem and pancerebellar atrophy, as opposed to the two SCA3 patients, who had only mild cerebellar vermian atrophy. In such situations, molecular confirmation of all patients may avoid misdiagnosis of SCA subtypes and eventual errors in predictive testing of unaffected family members.     

大鼠静脉窦高压致硬膜血管变化的研究

目的探讨大鼠静脉窦高压后硬膜血管变化及其静脉窦高压在硬脑膜动静脉瘘形成中的作用。方法体重200～250g的SD雄性大鼠110只,随机分为静脉窦高压组(85只)和假手术组(25只),将静脉窦高压组85只大鼠闭塞左侧横窦和上矢状窦前1／3,并吻合右侧颈总动脉和颈外静脉,制成静脉窦高压模型。假手术组大鼠单纯解剖相应的颈部血管和硬脑膜窦,但不行吻合或闭塞。术后90d,随机取7只静脉窦高压组大鼠和5只假手术组大鼠,行硬脑膜血管明胶墨汁灌注,观察硬膜血管的状况。结果术后90d静脉窦高压组和假手术组大鼠的硬膜血管数分别为(10.7±1.5)条／mm,(10.3±0.6)条／mm,差异无显著性。在静脉窦高压组中1只大鼠有硬脑膜动静脉瘘,其形态和结构与生理性动静脉短路类似。结论大鼠静脉窦高压一段时间后,颅内硬膜血管无明显增生。颅内硬脑膜动静脉瘘的形成很可能是由动静脉间的短路发展而来。