骨髓间质干细胞修复大鼠脊髓损伤的效果的实验研究

目的研究骨髓间质干细胞（Bone marrow stromal cells，BMSCs）用于修复大鼠脊髓损伤（spinal cord injury，SCI）的效果。方法30只成年SD大鼠按改良Tuszynsl法建立大鼠脊髓完全横断伤模型，损伤水平位于T9，损伤24h后随机分为对照组、实验组，实验组经尾静脉注射BMSCs，对照组经静脉注射PBS。利用BBB（Basso-Beetle-Bresnahan）评分法进行后肢运动功能评价，并进行斜板实验。结果实验组运动功能改善，实验组与对照组的BBB评分比较差异有统计学意义（P〈0．05），实验组的神经功能恢复较快。其中实验组大鼠在注射BMSCs后35d时后肢能支撑身体站立行走。斜板实验结果2组相比有显著性差异（P〈0．05）。结论骨髓间质干细胞移植组大鼠脊髓功能恢复优于对照组，说明骨髓间质干细胞用于修复大鼠SCI作用显著。     

骨髓基质干细胞移植治疗大鼠脊髓挫伤中碱性成纤维生长因子的变化

探讨骨髓基质干细胞(BMSCs)对脊髓损伤修复的可能作用及其对bFGF表达的影响,为BMSCs修复脊髓损伤提供实验依据。采用改良的Allen的WD法建立脊髓(T12节段)损伤模型,将66只SD大鼠随机分为正常组(A组)、损伤后未移植的对照组(B组)和BMSCs移植治疗组(C组)。通过BBB行为学评分记录两组动物后肢恢复功能,免疫组织化学方法检测bFGF的表达。结果显示:BMSCs移植组BBB评分高于对照组;bFGF在各组大鼠脊髓中均呈阳性表达,损伤后对照组与BMSCs移植组各个时点的表达量仍高于正常组(P<0.05),7d最高,后渐下降,但21d表达仍高于正常。其中BMSCs移植组与对照组各个时点的bFGF表达量均有显著差异(P<0.05)。结果提示:BMSCs移植治疗大鼠脊髓损伤模型有助于其功能的恢复。     

体外转染绿色荧光蛋白基因的肌源性干细胞移植修复大鼠脊髓损伤

背景:肌源性干细胞易于提取、分离及扩增,在特定条件下可分化为骨、软骨、肌肉等中胚层组织细胞,还可以跨胚层分化为神经细胞等,是组织工程临床用于脊髓损伤修复的理想种子细胞。目的:观察肌源性干细胞移植对脊髓半切损伤大鼠运动功能的修复作用。方法:40只成年SD大鼠随机数字表法分为移植组和对照组,每组20只。均进行脊髓半切损伤,伤后9d,移植组于伤处移植体外转染绿色荧光蛋白基因的大鼠肌源性干细胞,而对照组仅注射等量PBS,于移植后1,2,3,4周用斜板实验和BBB评分测大鼠的运动功能,同时进行损伤脊髓取材、快速冰冻切片进行荧光显微镜观察。结果与结论:所有大鼠脊髓半切损伤手术均成功,术后无动物死亡。肌源性干细胞移植后1周,移植组与对照组均有所恢复,斜板实验和BBB评分差异无显著性意义(P0.05);2~4周移植组恢复明显较好,斜板实验和BBB评分显著高于对照组(P0.05),移植组后肢活动与前后肢活动的协调性明显优于对照组。荧光显微镜观察经诱导分化和基因标记的肌源性干细胞在损伤脊髓组织局部生长良好,并且有沿着脊髓神经束向头尾两侧迁移的趋势。提示脊髓半切损伤大鼠经肌源性干细胞移植后能在损伤脊髓组织局部长期存活并明显改善其运动功能,肌源性干细胞移植对脊髓半切损伤大鼠有修复作用。     

存储条件对骨髓间充质干细胞的生物学特性和修复脊髓损伤效能的影响

目的探讨0.9%生理盐水(Saline)、0.01M磷酸盐缓冲液(phosphate buffered saline,PBS)对骨髓间充质干细胞(bone marrow stem cells,BMSCs)存活、增殖等生物学特性以及对修复脊髓损伤(spinal cord injury,SCI)模型大鼠损伤效能的影响。方法体外,分离培养C57BL/6小鼠BMSCs,进行生理盐水、PBS及增殖培养基(PCM)处理不同时间,通过台盼蓝染色法检测各组细胞的活力,通过Brd U法检查各组细胞增殖情况。体内,通过LFB染色法检测各移植组SCI大鼠脊髓组织髓鞘再生情况;通过BBB运动功能评分检测大鼠运动功能恢复情况。结果存储液处理的BMSCs呈现出时间依赖的存活与增殖能力下降,PBS-BMSCs组存活率下降程度小于Saline-BMSCs组。移植组大鼠运动功能和损伤脊髓横断面髓鞘化程度显著恢复,并且PBS-BMSCs治疗组优于Saline-BMSCs治疗组。结论存储液处理BMSCs对SCI有治疗作用。     

miR-186-5p修饰骨髓间充质干细胞通过下调FZD3对脊髓损伤大鼠具有神经保护作用

目的 探讨miR-186-5p修饰的骨髓间充质干细胞对脊髓损伤大鼠的神经保护作用及可能机制.方法 40只SD大鼠随机分为假手术组(Sham组)、脊髓损伤模型组(SCI组)、骨髓间充质干细胞移植组(BMSCs组)和miR-186-5p修饰的骨髓间充质干细胞移植组(miR+BMSCs组),每组10只;除了Sham组,其余三组通过Allen's法建立SCI大鼠模型,移植后第1、7、14、21天对各组大鼠进行运动功能(BBB)评分;HE染色观察各组大鼠脊髓损伤病理学变化;IF检测NeuN表达情况;ELISA检测NT-3含量变化;利用qRT-PCR检测各组大鼠miR-186-5p的表达;荧光素酶实验验证miR-186-5p与FZD3的关系;Western blot方法检测损伤脊髓组织中的FZD3、β-catenin、c-Myc、cyclinD1的表达水平变化.结果 与SCI组相比,BMSCs组和miR+BMSCs组的BBB评分、损伤脊髓组织中NeuN的表达、NT-3的表达以及β-catenin、c-Myc、cyclinD1的蛋白表达均明显升高(P＜0.05),FZD3的蛋白表达明显下降(P＜0.05).FZD3被预测并确认为miR-186-5p的靶基因.与BMSCs组相比,miR+BMSCs组的BBB评分、损伤脊髓组织中NeuN的表达、NT-3的表达以及β-catenin、c-Myc、cyclinD1的蛋白表达显著升高(P＜0.05),FZD3的蛋白表达呈下降趋势(P＜0.05).结论 miR-186-5p修饰的骨髓间充质干细胞移植可通过下调FZD3对SCI大鼠的神经提供保护作用.     

骨髓间充质干细胞静脉移植治疗大鼠脊髓损伤

背景：干细胞移植可以重建中枢神经系统的结构和功能,近年来引起了广泛的关注。 目的：尾静脉移植骨髓间充质干细胞观察其对大鼠脊髓损伤修复的影响并探讨其机制。 方法：密度梯度离心法结合贴壁筛选法分离骨髓间充质干细胞。将成年雌性Wistar大鼠以动脉瘤夹钳夹法制备大鼠脊髓损伤模型后随机分为细胞移植组和对照组,分别干预。 结果与结论：细胞移植组大鼠BBB后肢功能评分恢复优于对照组(P < 0.05)。自损伤后第30天开始,细胞移植组大鼠运动诱发电位潜伏期及体感诱发电位P1波潜伏期的恢复均优于对照组(P < 0.05),并持续至实验结束。细胞移植组大鼠脊髓内在损伤中心及头、尾端距离脊髓损伤中心1 cm处均可见阳性细胞。说明尾静脉注射移植骨髓间充质干细胞可以促进脊髓损伤大鼠神经功能恢复,其机制可能与移植细胞迁移到损伤部位,分化为神经元样和神经胶质细胞样细胞,并分泌或促进宿主分泌神经营养因子有关。     

电针刺激经Wnt / β-catenin 信号通路促进脊髓损伤大鼠移植骨髓间充质干细胞的存活及分化

目的:探讨电针(EA)刺激对移植骨髓间充质干细胞(BMSCs)在脊髓损伤(SCI)大鼠局部存活和分化的影响,及其与Wnt/β-catenin信号通路的关系。方法:体外分离和培养大鼠BMSCs,5-溴脱氧尿嘧啶核苷(BrdU)进行标记用于移植。将60只雄性SD大鼠随机分为假手术组(sham)、模型组(SCI)、BMSCs移植组(BMSCs)、BMSCs移植+EA组(BMSCs+EA)和抑制剂IGC-001干预组(BMSCs+EA+IGC-001),每组12只。除sham组外,各组采用改良Allen′s打击法建立SCI模型,尾静脉注射被BrdU标记的BMSCs,并给予EA和IGC-001干预4周。移植后第1、7、14、21、28天采用BBB运动评定量表评估各组大鼠后肢运动功能;4周后,采用ELISA法检测损伤脊髓组织匀浆中神经营养素3(NT-3)的含量;免疫荧光实验检测损伤脊髓组织局部BrdU和神经元特异性核蛋白(NeuN)表达,评估BMSCs移植后的存活及分化情况;Western blot检测损伤脊髓组织β-catenin、c-Myc和cyclin D1等蛋白表达水平。结果:BMSCs组大鼠BBB评分、损伤脊髓组织中NT-3含量及β-catenin、c-Myc、cyclin D1等蛋白表达水平均较SCI组显著升高(P0.05);BMSCs+EA组大鼠BBB评分,损伤脊髓组织中NT-3含量和β-catenin、c-Myc、cyclin D1等蛋白表达水平及移植后BMSCs存活数量和BMSCs分化的神经元样细胞数量均较BMSCs组显著增加(P0.05)。IGC-001干预可显著逆转EA刺激作用。结论:EA刺激可促进SCI大鼠移植BMSCs存活及向神经元样细胞分化,其机制可能与激活Wnt/β-catenin通路介导的NT-3表达有关。     

人骨髓间质干细胞和嗅鞘细胞移植对大鼠急性脊髓损伤功能修复的比较研究

目的对比人骨髓基质细胞(BMSCs)与人胚嗅鞘细胞(OECs)移植对大鼠脊髓损伤功能修复的影响。方法将45只SD大鼠分成脊髓损伤后BMSCs移植组(BMSCs组)、OECs移植组(OECs组)和PBS对照组(PBS组),通过BBB评分、运动诱发电位(MEP)评估脊髓传导功能的改善状况,免疫组织化学方法检测移植细胞存活和分化情况,病理形态学方法观察组织结构修复情况。结果BMSCs组BBB评分高于OECs组(P<0.05);两细胞治疗组MEP潜伏期明显缩短(P<0.05);BMSCs组嗜银染色可见脊髓损伤近端有较多再生纤维向远端延伸,形成神经纤维束,而OECs组再生纤维较少;两种移植细胞均可在损伤处部分存活,BMSCs组可见BMSCs来源的细胞Nestin、NF、GFAP的阳性表达。结论BMSCs移植比OECs移植能更有效促进大鼠急性脊髓损伤修复。     

骨髓间充质干细胞移植脊髓全横断模型大鼠运动和体感诱发电位的评价

背景：临床常用皮质运动诱发电位和皮质体感诱发电位来分别评价脊髓损伤后运动传导路和感觉传导路的损伤或修复情况。 目的：以脊髓诱导电位监测骨髓间充质干细胞移植后急性脊髓完全性损伤大鼠下肢神经功能的变化。 方法：选取健康Wistar大鼠50只,分成5组,即生理盐水组、骨髓间充质干细胞移植组、脑源性神经营养因子修饰组、神经营养素3+骨髓间充质干细胞移植组和假手术组。除假手术组外,其余各组均制作Allen’s脊髓完全性损伤动物模型,造模后各组均行相应治疗。治疗后4,8和12周行大鼠后肢运动功能评分,并于造模后24 h,3,7,14 d行运动和体感诱发电位检测。 结果与结论：运动诱发电位检测结果提示,各治疗组的运动功能均有不同程度的恢复,与生理盐水组间差异均有显著性意义(P < 0.05),大鼠后肢BBB评分也证实了各治疗组后肢运动功能明显优于生理盐水组(P < 0.05)。提示经脑源性神经营养因子修饰的骨髓间充质干细胞可移植到脊髓损伤处,可改善大鼠的后肢运动,神经营养素3蛋白有可能提高骨髓间充质干细胞在体内的生存率,促进受损脊髓的轴突再生。     

低频电磁场促进骨髓间充质干细胞移植修复大鼠脊髓损伤的实验研究

背景：骨髓间充质干细胞移植治疗脊髓损伤被视为一种有前途的治疗方法,如何更有效地促进骨髓间充质干细胞在脊髓损伤区存活,加速脊髓损伤肢体运动功能的恢复是目前研究的重点。前期研究发现,低频电磁场能够促进骨髓间充质干细胞的增殖分化,低频电磁场是否可应用于骨髓间充质干细胞移植治疗脊髓损伤还需进一步研究。 目的：探讨低频电磁场对移植骨髓间充质干细胞脊髓损伤大鼠后肢运动功能恢复的影响。 方法：采用脊髓压迫法制备64只T10不完全性脊髓损伤大鼠模型,随机等分为对照组、骨髓间充质干细胞组、电磁场组和电磁场+骨髓间充质干细胞组。造模成功后,骨髓间充质干细胞组和电磁场+骨髓间充质干细胞组大鼠脊髓损伤原部位注射大鼠全贴壁法分离培养BrdU标记的骨髓间充质干细胞,对照组和电磁场组注射a-MEM培养液。造模术后24 h,电磁场组和电磁场+骨髓间充质干细胞组予60 min/d的低频电磁场刺激(频率50 Hz、强度5 mT)。 结果与结论：骨髓间充质干细胞移植后第21天,电磁场+骨髓间充质干细胞组BBB评分与其他组相比,差异有显著性意义(P < 0.05),与其他各组比较,电磁场+骨髓间充质干细胞组移植细胞后,大鼠BrdU阳性细胞在脊髓损伤区域生长并与脊髓组织融合,存活细胞数量较其他组多;空洞面积小;损伤区胶质纤维酸性蛋白表达更少,而基质金属蛋白2表达更多;脊髓损伤大鼠下肢运动功能恢复最快(P < 0.05)。提示低频电磁场促进了移植骨髓间充质干细胞脊髓损伤大鼠后肢运动功能的恢复,可能与低频电磁场有利于损伤区移植骨髓间充质干细胞的存活,上调基质金属蛋白2的表达并减少胶质瘢痕的形成有关。     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Intestinal helminthiasis in school children in Haiti in 2002

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.     

Experience in adult population in dengue outbreak in Delhi

A dengue outbreak has recently hit the Indian capital. We studied the clinical profile of adult patients. Five hundred and sixty patients of dengue infection were admitted in a specially created ward according to the criteria laid down by WHO. Haematemesis (28.28%), epistaxis (26.78%) and malena (14.28%) were some of the common presentations. Similarly lymphadenopathy, especially cervical (30.89%), palatal rashes (26.96%) and hepatomegaly (23.75%) were the most commonly encountered findings on physical examination. Most of the cases were of dengue fever with haemorrhage and only 2.5% cases were classified under dengue haemorrhagic fever or dengue shock syndrome. The average hospital stay was 3.4 days but only 9.8 hours in the eleven patients who died, suggesting their late arrival in preterminal situation giving little time for resuscitation. Thrombocytopenia was not a feature and only 12.85% patients had platelet count less than 70,000/cmm. Most of the patients who were admitted with thrombocytopenia, showed normalization in their platelet counts in next few days. Serological examination demonstrated evidence of recent dengue infection in 41.17% patients. Few patients required blood or platelet concentrate transfusion. Eleven patients died, three due to DIC, one of intracranial haemorrhage and seven due to massive gastric haemorrhage. Rest of the patients recovered completely. Thus we can conclude that recent outbreak in Delhi was of dengue fever with haemorrhage and mortality was very low in patients who came early to the hospital.     

Changes in the hypothalamic nuclei in in experimental allergy

Summary In rabbits subjected to prolonged sensitization and in which the Arthus phenomenon was induced there was a marked reaction of the hypothalamic nuclei. Staining by Gomori's method indicated a cellular swelling, loss of granules, and protoplasmic vacuolization in the supraoptic nucleus. There was a considerable increase in the size of the cross-sectional area of the cells. The same effects were much less well shown in the paraventricular nucleus. These results show that marked signs of increased neurosecretion developed in the animals at the height of the Arthus phenomenon.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten Éksperimental'noi biologii i Meditsiny, Vol. 55, No. 4, pp. 110–113, April, 1963.     

Development in in vitro toxicology

There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93.