Use of cerebrospinal fluid gating to improve T2-weighted images. Part I. The spinal cord

Ungated and gated magnetic resonance images of the spinal cord acquired with the use of long repetition times (TRs) and long echo-delay times (TEs) were compared in 21 studies performed on a 1.5-T system. Both normal and abnormal spinal cord conditions were compared. All images were acquired in an identical fashion except that ungated studies had TRs of 2,000 or 2,500 msec, whereas in gated studies, TR was determined by the patient's heart rate. The effective TR of images gated to the cerebrospinal fluid (CSF) fell primarily in the range of 1,500-1,800 msec. Gating was accomplished using a peripheral pulse. Three image parameters were assessed: signal-to-noise ratio, object contrast, and resolving power. For each parameter, in both normal and abnormal spinal cords, the CSF-gated studies proved superior by eliminating spatially mismapped signal intensity from pulsatile CSF.     

Multi-section multi-echo pulse magnetic resonance techniques: optimization in a clinical setting

The user-selectable magnetic resonance imaging parameters involved in a multi-section multi-echo pulse sequence are described and their interrelationships explained. These parameters include repetition time (TR), echo delay time (TE), the number of sections (S), the number of echoes (E'), the time from the center of the last echo to the end of data acquisition (15 msec on the authors' system), and the time for T1 recovery. A simple mathematical relationship among these quantities, permitting easy calculation of the remaining parameters once a sufficient number have been specified, is given. In addition, a nomogram that permits rapid visual estimation of these parameters is presented. The effects of these choices and others is explained with respect to imaging time, region covered, and image contrast. Finally, the inherent trade-offs are illustrated in a clinical example involving the pelvis.     

Imaging of tumoral calcinosis: new observations

Five patients with tumoral calcinosis were evaluated with radiography, bone scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging. The arthropathy of calcium pyrophosphate dihydrate deposition disease was seen in two of the patients and pseudoxanthoma elasticum-like syndrome in three. Identification of calcific particular masses on radiographs is characteristic of tumoral calcinosis. Marrow lesions could be identified as patchy areas of calcification (calcific myelitis) in long bones and the calvarium. Bone scintigraphy appears to be the best modality for detection of the masses and marrow lesions and for monitoring therapy. At CT the masses demonstrated a varied appearance, from small and solid to large and cystic. The marrow abnormality appears as an area of increased attenuation and spotty calcification that in the skull may be associated with dural and vascular calcifications. MR imaging of the particular masses was remarkable in that the masses displayed high signal intensity on T2-weighted images despite a large calcific component. Marrow lesions also showed increased signal intensity on T2-weighted images. When calcified particular masses are present the diagnosis is rarely in question. The diagnosis may be overlooked, however, when calcific myelitis is the only manifestation.     

(-)棉酚和(+)棉酚对蛋白激酶C及蛋白激酶A活力影响的比较

部分纯化的大鼠肝脏蛋白激酶C和蛋白激酶A,在体外与棉酚的旋光异构体分别温育,结果(--)棉酚和(+)棉酚对蛋白激酶C活力均有剂量依赖性的抑制作用;(-)棉酚对Ⅰ型蛋白激酶A活力的抑制作用明显比(+)棉酚强,而(-)棉酚和(+)棉酚在高浓度时对Ⅱ型蛋白激酶A才显示抑制作用。结果提示棉酚在体内可能干扰细胞信息的传递过程。     

CN3OP: an active regimen in patients with relapsed/refractory Hodgkin's lymphoma

Patients with recurrent or refractory Hodgkin's and non-Hodgkin's lymphoma are increasingly being treated with high-dose therapy and hematopoietic cell transplantation. As minimal disease status at the time of transplant has been a repeatedly proven significant prognostic factor for long-term survival, effective initial cytoreduction is an important step in the process. Modern chemotherapy programs for Hodgkin's lymphoma include virtually all active agents and little is left for effective salvage. Mitoxantrone is an active agent in lymphoma that is not generally used in first-line treatment. The aim of this study was to determine toxicity and response rate to CN3OP (fractionated mitoxantrone 6 mg/m² on days 1,2 and 3, combined with standard dose cyclophosphamide, vincristine, and prednisone) in 44 patients with relapsed or refractory lymphoma., Most of patients had advanced disease and one or more extranodal sites at relapse. Median response duration to immediate past therapy was four months, and one third of patients had not responded to prior treatment. A median of 4 cycles of CN3OP were given per patient for a total of 173 cycles. Grade III–IV neutropenia occured in 53% of cycles, Grade I–III mucositis in 24%, and Grade I–III infection in 17% of cycles. of 34 evaluable patients with Hodgkin's lymphoma 12 (35%) achieved complete remission (CR) and 15 (44%) partial remission (PR) for an overall response rate of 79%. Two of five evaluable non-Hodgkin's lymphoma patients responded with PR. Median overall survival and event free survival in the entire group was 29 months and 11 months respectively. At this time 16 patients have died; 12 of lymphoma, two of unknown cause and two of other causes. Complete response to CN3OP correlated with survival. CN3OP is an effective and safe regimen for cytoreduction in Hodgkin's lymphoma patients pretreated with doxorubicin/alkylator/etoposide-containing primary therapies.     

Severe combined immunodeficiency and adenosine deaminase deficiency: failure of enzyme replacement therapy

A first-born baby boy presented at age 3 months with persistent diarrhoea, failure to thrive, and recurrent bacterial and fungal infections. Severe combined immunodeficiency was demonstrated. A deficiency of adenosine deaminase (ADA) activity was suggested by the presence of extensive skeletal abnormalities, and the ADA activity in erythrocyte and leucocyte lysates was < 0.005 nmol/h per mg protein. Culture of ADA-negative peripheral blood mononuclear cells, together with purified calf ADA, did not alter the absent phytohaemagglutinin response. Treatment with immunoglobulin, pentamidine, and co-trimoxazole was started and a programme of ADA enzyme replacement, with infusions of plasma and frozen irradiated erythrocytes, was begun at age 4 months and achieved blood ADA levels in excess of 30 nmol/h per mg haemoglobin. Although resolution of the interstitial pneumonitis and skeletal abnormalities was observed, there was no evidence of immunological reconstitution. The patient died at age 17 months after a parainfluenza pneumonitis. Features of importance in predicting lack of benefit from enzyme replacement by erythrocyte infusion in ADA-negative severe combined immunodeficiency appear to be early clinical presentation with associated severe skeletal abnormalities, a very low level of residual ADA activity in peripheral blood mononuclear cells, and lack of effect of exogenous ADA on the absent in vitro mitogen response of ADA-negative blood mononuclear cells.     

重庆市两所大学学生营养知识、态度及行为的基线调查

目的:了解重庆市某两所大学学生的营养知识、态度和行为现况,为开展营养教育效果评价提供基线数据。方法:选取重庆渝中区某学院为干预学校,文理科各一个系,整群抽取一年级9个班的学生,共289人;选取九龙坡区某学院为对照学校,选择与干预学校相匹配的文理科各一个系,整群抽取9个班的学生,共344人。于2005-03采用自编调查问卷,对以上633名在校学生进行营养知识、态度和行为的调查。问卷内容包括一般人口统计学资料、营养知识、态度、行为情况,营养知识获取途径等,其中知识问题满分16分,有关态度问题满分9分,行为问题满分40分,得分越高越好。结果:发放问卷650份,回收有效问卷633份,有效率97.4%。①两组学生一般人口学特征和家庭背景均有可比性(P>0.05)。②干预学校学生营养知识、态度和行为得分分别为(9.04±2.43),(7.13±1.20),(16.27±3.53)分,对照学校得分分别为(9.23±2.22),(6.96±1.28),(16.38±3.39)分,两组比较无差异。③只有30.33%的同学每天吃早餐,只有37.91%的学生在选择食物时考虑了营养价值或自己的营养需要,不常吃水果,常吃零食现象严重。大部分学生都有良好的求知欲望,希望通过多种途径获得营养知识。结论:①大学生对营养知识缺乏全面深入的了解,大部分学生营养态度端正,行为良好,但部分学生也存在一些问题。②两所学校营养知识、态度与行为无显著差异。     

壳聚糖导管复合自体骨髓间充质干细胞修复大鼠13mm坐骨神经缺损

目的:观察壳聚糖神经导管复合自体骨髓间充质干细胞,构建组织工程化人工神经,修复大鼠13mm坐骨神经缺损的效果。方法:实验于2002-10/2004-08在北京军事医学科学院基础医学研究所九室及河北大学附属医院中心实验室完成。实验分组:Wistar大鼠30只按随机数字表法分成3组,实验组、细胞外基质凝胶组和生理盐水对照组,每组10只。壳聚糖神经导管桥接大鼠右侧13mm坐骨神经缺损。实验组无菌条件下抽取股骨髓腔内骨髓组织,贴壁分离法纯化、增殖骨髓间充质干细胞,按1×109L-1细胞浓度与细胞外基质凝胶混合,植入自体神经再生室内;细胞外基质凝胶组神经再生室内植入细胞外基质凝胶,生理盐水对照组神经再生室内植入生理盐水。实验评估:术后12周观察以下指标:①大体观察:观察再生神经。②坐骨神经功能指数测定:选择印迹清晰的足印分别测量正常足(N)和伤侧足(E)的3个指标:足印长度(PL):足尖到足跟的最大距离;足趾宽度(TS):第1～5趾的距离;中间足趾宽度(IT):第2～4趾的距离。结果精确到0.1mm。坐骨神经指数=-38.3[(EPL-NPL)/NPL] 109.5[(ETS-NTS)/NTS]] 13.3[(EIT-NIT)/NIT]-8.8。坐骨神经指数值为0～-11%表示神经功能完全正常,-100%表示神经功能完全丧失,-11%～-100%表示部分神经功能恢复。③电生理检测:检测患侧小腿三头肌肌电图,检测再生神经的运动传导速度和波幅。④腓肠肌湿质量恢复率:腓肠肌湿质量恢复率(%)=手术侧腓肠肌湿质量/对侧正常腓肠肌湿质量×100%。⑤神经组织学检查:苏木精-伊红及Loyez苏木精髓鞘染色,光镜下观察再生神经横断面再生神经髓鞘的形成;Loyez苏木精髓鞘染色及Bielschowsky改良镀银染色,观察纵向切片再生神经神经纤维;神经细丝蛋白免疫组化染色,观察再生的神经轴突染色。随机选取部分正常坐骨神经作为正常对照。⑥透射电镜观察:再生神经的超微结构。⑦再生神经纤维图像分析:观察再生神经有效神经截面积、有髓神经纤维数目、有髓神经纤维密度、有髓神经纤维直径、髓鞘厚度。结果:30只大鼠全部进入结果分析。①大体观察:术后12周,实验组及细胞外基质凝胶组导管内均有再生神经生成,外形似正常神经,直径较正常神经细,生理盐水对照组导管内无再生神经通过间隙。②坐骨神经指数:术后8,12周实验组坐骨神经指数高于细胞外基质凝胶组[分别为(-72.18±3.11)%,(-76.85±2.76)%;(-62.91±2.87)%,(-69.63±2.52)%],差异有显著性意义(F=7.85,P<0.01)。③电生理检查:术后12周实验组运动神经传导速度及波幅明显高于细胞外基质凝胶组[分别为(41.29±3.83),(32.64±3.52)m/s;(3.21±0.34),(2.85±0.22)mV],差异有显著性意义(F=6.39,P<0.01)。实验组、细胞外基质凝胶组腓肠肌肌电图呈部分失神经电位表现,生理盐水对照组则为完全失神经电位。④腓肠肌湿质量恢复率:实验组、细胞外基质凝胶组腓肠肌湿质量恢复率明显高于生理盐水对照组[分别为(69.32±2.65)%,(66.72±1.75)%,(53.41±1.97)%],差异有非常显著性意义(F=9.32,P<0.01),实验组与细胞外基质凝胶组比较差异有显著性意义(F=6.25,P<0.05)。⑤组织学检查:术后12周实验组、细胞外基质凝胶组再生神经纤维排列整齐、密集,神经导管交界处无瘢痕,实验组再生神经纤维多且直径较粗大,排列更为规则。⑥透射电镜观察:实验组和细胞外基质凝胶组均见再生的有髓神经纤维。⑦再生神经纤维图像分析:术后12周实验组有髓神经纤维密度、神经纤维有效面积、有髓神经纤维数量、直径及髓鞘厚度均优于细胞外基质凝胶组。结论:壳聚糖神经导管复合自体骨髓间充质干细胞能够促进周围神经的再生并可以作为种子细胞构建人工神经应用于周围神经缺损的修复。