不同结合状态硫酸软骨素多糖链对体外二维三维培养背根节神经突起生长影响研究

目的构建鸡胚背根节细胞3D生长模型,观察CSPG对不同浓度的琼脂糖水溶胶培养基对鸡胚背根节神经突起生长的影响。方法①利用多肽缩合剂1’1羰基二咪唑介导CS-B长链与琼脂糖凝胶共价结合。②分别配制0.5%、0.75%、1%、1.25%、1.5%的SeaPrep琼脂糖凝胶溶液和共价结合了CS-B多糖长链的琼脂糖凝胶溶液。取孵育9~10天后鸡胚背根节加入上述凝胶溶液加培养液培养。③培养24小时之后在24 h、48 h7、2 h、96 h进行观察拍照。观察各时间点神经突起生长情况。结果①鸡胚背根节神经突起在1.25%的琼脂糖凝胶溶液中开始呈3D生长,在小于1%的琼脂糖溶液中只能2D生长。②在同一时间点,呈2D生长的背根节突起和呈3D生长的背根节突起在突起长度方面没有统计学差异(P>0.05)。③3D生长的DRG神经突起在共价结合了CS-B的琼脂糖凝胶中生长长度明显短于普通琼脂糖水凝胶(P<0.05),并且可观察到部分突起长出短而直的成束突起。但是对于呈2D生长的DRG突起长度在两种培养基中却未见差异(P>0.05)。结论鸡胚背根节神经元周围突起生长长度在3D培养中与在2D培养中有没有明显的差异。硫酸软骨素能够有效抑制呈3D生长的神经节突起生长,并且影响到神经突起的生长方式。但是在2D培养基中,未能看到上述的抑制作用。     

激活素A与NGF协同刺激鸡胚背根神经节神经突起生长

目的:探讨激活素A(Activin A)与神经生长因子(Nerve growth factor,NGF)共同刺激鸡胚背根神经节(DRG)神经突起生长作用。方法:采用8 d的鸡胚DRG原代培养法,通过Activin A与NGF联合刺激,观察DRG神经突起生长和DRG神经元存活情况。采用RT-PCR检测钙基因相关肽(CGRP)。结果:Activin A与NGF体外联合培养3 d时DRG神经突起生长比单纯NGF组更明显,DRG神经元存活数量也明显增加,Activin A与NGF联合作用可以明显促进CGRP mRNA表达。结论:Activin A对NGF诱导的鸡胚DRG神经突起生长和维持DRG神经元存活具有增强作用,提示二者的联合应用可能为治疗神经元损伤及变性疾病的应用提供了新的数据和实验依据。     

神经生长颗粒含药血清对大鼠背根神经节生长的影响

目的: 研究神经生长颗粒(NGG)含药血清对体外培养新生大鼠背根神经节生长及高分子量神经丝蛋白(NF-H)和生长相关蛋白43(GAP43)表达的影响.方法: 采用体外大鼠背根神经节(DRG)植块培养,通过免疫荧光细胞化学法,观察不同剂量的含药血清对DRG神经突起生长的影响;采用DRG单细胞分离培养,通过实时荧光定量PCR和免疫印迹法分别观察不同剂量的含药血清对DRG细胞NF-H和GAP43基因及蛋白表达的影响.结果: 免疫荧光细胞化学法提示NGG含药血清能促进DRG神经突起的生长;实时荧光定量PCR和免疫印迹法结果提示NGG含药血清能增加体外培养的DRG细胞NF-H、 GAP43 mRNA和蛋白的表达.结论: NGG含药血清能促进体外培养DRG神经突起的生长并促进NF-H和GAP43的表达,表明NGG对发育期感觉神经元具有一定的神经营养作用.     

食管鳞癌组织中的肽能神经支配研究

目的　探讨食管鳞癌组织中的肽能神经支配情况。　方法　采用免疫组织化学ABC法 ,检查外科手术取得的食管鳞癌标本中 10种神经肽免疫反应性神经纤维的分布及其与肿瘤细胞的关系 ;采用食管鳞癌组织块和鸡胚背根神经节共培养的方法 ,初步探讨肿瘤组织对神经元的影响 ,以推测肿瘤中神经纤维的来源。　结果　食管鳞癌组织中存在相当数量的GAL、SP、NPY等多种神经肽免疫反应神经纤维 ,神经纤维与肿瘤细胞紧密接触。共培养组有约 6 3%的神经节长出突起 ,其中有 49%的神经节突起在靠近肿瘤组织块的一侧较浓密 ,对侧则较稀少。对照组鸡胚神经节则无突起生长。　结论　食管鳞癌组织中可能存在肽能神经支配 ;食管鳞癌组织块对神经节突起具有促生长作用。     

神经再生素促大鼠背根神经节生长作用的研究

目的研究神经再生素（NRF）对体外培养新生大鼠背根神经节生长及NF—H表达的影响。方法体外大鼠背根神经节（DRG）培养;免疫荧光细胞化学、实时荧光定量PCR和Western blot等方法。结果免疫荧光细胞化学结果提示,NRF能促进背根神经节神经突起的生长,浓度为2．0mg／L时生长状况最佳;实时荧光定量PCR和Western blot结果提示,NRF能增加体外培养的背根神经节NF-H mRNA和蛋白的表达,在浓度为2．0mg／L时表达最高。结论NRF能促进体外培养背根神经节神经突起的生长和NF—H的表达,表明NRF对发育期感觉神经元具有神经营养作用。     

组织外植块对培养的鸡胚背根节神经突起生长的影响

为了解神经元的发育和周围组织的关系,本文分别用了:(1)10天鸡胚背根节与10天鸡胚心脏、皮肤、角膜、骨骼肌、肠、大脑、脊髓外植块联合培养;(2)不同时期的鸡角膜与不同胚龄的鸡胚背根节联合培养;(3)10天鸡胚背根节与雏鸡角膜内、外层联合培养。实验结果表明鸡胚心脏、皮肤和角膜外植块对背根节神经突起生长具较强的促进作用且对生长方向有明显诱导作用;骨骼肌、肠和大脑对神经突起生长也有不同程度促进作用,但脊髓却无明显作用。14、16、18天鸡胚角膜对8、10、12、14天鸡胚背根节神经突起生长有明显促进作用;12、14天鸡胚背根节在各时期角膜作用下神经突起生长都较丰富。含上皮层的雏鸡角膜外植块促进背根节神经突起生长的作用比含内皮层的角膜外植块强。     

PKAc促进成年大鼠背根神经节神经元突起生长及其机制的研究

观察慢病毒载体介导PKA催化亚单位PKAc转染促进成年大鼠原代培养的背根神经节(DRG)神经元突起生长及其机制的研究。我们运用三质粒系统共转染293T细胞合成慢病毒载体LV/PKAc-IRES-GFP和对照病毒LV/GFP,原代分离培养成年大鼠DRG神经元,应用免疫组织化学染色和Western blot等方法检测cAMP/PKA信号通路下游关键转录因子cAMP反应元件连接蛋白(CREB)磷酸化水平,图像分析经组织化学染色后的神经元突起长度和有突起神经元的百分比。结果观察到,慢病毒能介导外源基因在哺乳动物原代培养的神经元中表达,转染LV/PKAc-IRES-GFP的PC12细胞和DRG神经元均能表达外源基因并激活CREB,克服CNS髓鞘蛋白的抑制,促进突起生长。以上实验结果表明拯救成年大鼠神经元cAMP/PKA水平可有效改变神经元内在生长能力,从而改变它们对抑制环境的敏感性,进而促进突起生长。     

备用根大鼠脊髓后角组织神经营养活性物质的分离纯化和生物活性鉴定

<正> 本实验采用凝胶过滤层析法和高效液相色谱技术,分离纯化备用根大鼠部分去传入侧的脊髓后角组织中的神经营养活性物质.1.生物活性检测方法的建立:切除大鼠一侧背根和背根节(DRG),仅保留L-4背根为备用根.术后动物存活5天.分别切取L1-L6节段手术侧和非手术侧脊髓后角组织,制备含手术侧和非手术侧提取液的培养液.用此液分别培养鸡胚DRG,48小时后手术侧组DRG神经突起密度明显大于对照组和非手术侧组,提示去传入纤维支配的脊髓后角组织存在着促神经突起生长的神经营养活性物质.又采用改良的悬滴培养法,发现手术侧脊髓后角组织能支持鸡胚DRG神经元的存活,而且具有促进神经突起生长的作用.2.备用根大鼠脊髓后角组织神经营养活性物质的分离与纯化,部分背根切除术后5天处死动物,切取手术侧脊髓L1-L6节段后角组织,匀浆、离心后,取上清液经Superdex prep grade G-75凝胶过滤层析,呈现Ⅰ、Ⅱ二个洗脱峰,将各洗脱峰浪加入培养基,Ⅰ峰洗脱液表现有神经营养作用.将Ⅰ洗脱峰进行SDS-聚丙烯酰胺凝胶电泳分析,银染后呈现多条明显的蛋白区带,去传入脊髓后角组织呈现神经营养活性的物质是在40-78KD之间.将Ⅰ峰洗脱液浓缩,进行高效液相色谱(HPLC)分析,得到4个不同的洗脱峰(a、b、c、d峰).将各洗脱峰液配制成不同浓度的     

神经节苷脂对损伤胎鼠背根神经节的保护作用

目的观察神经节苷脂(GM1)对受损伤胎鼠背根神经节(DRG)神经元形态改变的影响,探讨其可能的保护作用。方法选择胎龄为15d的SD大鼠为研究对象,获取DRG神经元并进行体外分散培养,培养48h后,随机分为对照组、谷氨酸损伤组和谷氨酸损伤+GM1保护组,继续培养12h。终止培养后,观察各组神经元的形态结构改变,用MTT法鉴定细胞的存活率。结果对照组DRG神经元细胞贴壁呈单层散在分布,少部分出现细胞聚集现象,突起较长且互相交织形成网状。谷氨酸损伤组DRG神经元细胞聚集现象明显,神经元突起变短、断裂甚至消失。谷氨酸损伤+GM1保护组DRG神经元细胞部分呈簇状聚集,部分呈单个散在分布,突起仍然相互交织。MTT结果显示谷氨酸损伤+GM1保护组细胞存活率高于谷氨酸损伤组。结论神经节苷脂可以影响损伤胎鼠DRG神经元的形态改变,对胎鼠背根神经节神经元具有一定的保护作用。     

胶质细胞源性神经营养因子对培养的背根神经节的影响

目的 探讨胶质细胞源性神经营养因子(GDNF)在体外促进正常胚胎大鼠背根神经节(DRGn)的存活及突起生长情况。方法 用原代分离培养法建立体外胚胎大鼠背根神经节单细胞培养体系，通过活体观察、MTT微量比色法、NSE免疫组织化学染色观察不同浓度GDNF对体外培养的正常感觉神经元的影响。结果 GDNF组培养的DRG神经元存活数量增加，神经元突起的长度比对照组明显增长。结论 GDNF能明显促进体外培养的正常大鼠胚胎背根神经节感觉神经元的存活及突起生长，表明GDNF对正常大鼠胚胎发育期感觉神经元具有神经营养作用。     

Rates of oxygen consumption and of anaerobic glycolysis in renal cortex and medulla of adult and new-born rats and guinea-pigs

1. Rates of oxygen uptake and of anaerobic glycolysis were estimated in slices from the renal cortex and medulla (a) of adult rats and guinea-pigs, (b) of new-born (1-, 5- and 21-day-old) rats and of guinea-pigs of 1, 12, 21, 24 and 120 hr age.2. In the adult rat, Q(O2) values for the cortex were 12.55 +/- 0.20 (22) and for the medulla: 8.56 +/- 0.17 (22) mul./hr.mg dry weight, while in the new-born rat (24 hr old) they were 10.99 +/- 0.46 (12) and 9.33 +/- 0.18 (9) mul./hr.mg dry weight respectively.3. Values for Q(CO2) (N2) (anaerobic glycolysis) in the 14 hr old new-born rat were in the renal cortex 9.65 +/- 0.35 (5) and in the medulla 7.39 +/- 0.43 (5) mul./hr.mg dry weight; while in the adult they were 2.25 +/- 0.08 (16) and 5.76 +/- 0.14 (16) mul./hr.mg dry weight, respectively.4. In the adult guinea-pig values for Q(CO2) (N2) were of the same order as in the adult rat, though the rate of O(2) uptake was for the cortex 8.12 +/- 0.22 (12) and for the medulla 5.02 +/- 0.23 (11) mul./hr.mg dry weight.5. Though the Q(O2) values in the renal cortex and medulla were smaller in the 1 hr old new-born guinea-pig, they were already increasing in the 12 hr old neonate.6. The results are discussed in the light of enzyme changes occurring during the process of maturation of the nephron as indicated by histochemical observations.     

Timing and intensity of early fevers and the development of allergies and asthma

BACKGROUND: Early childhood fevers appear to protect against later allergies and asthma. What is not known is the time in which fevers exert this effect and whether the degree of temperature increase is important. OBJECTIVE: We sought to examine the relationship between the time and degree of early fevers and later allergies and asthma. METHODS: Eight hundred thirty-five children from southeast Michigan were enrolled at birth. Clinic records from their first 2 years were abstracted for episodes of fever. At age 6 to 7 years, children underwent allergy testing. We examined fevers occurring within 6-month intervals in the first 2 years of life and outcomes at age 6 to 7 years. The primary outcome measures were allergic sensitization, asthma, asthma with allergic sensitization, and asthma without allergic sensitization. RESULTS: In the unadjusted analysis each episode of fever between 7 and 12 months of age was associated with a lower odds of allergic sensitization (odds ratio [OR], 0.71; 95% CI, 0.54-0.93) and asthma with allergic sensitization (OR, 0.43; 95% CI, 0.21-0.90) at age 6 to 7 years. Likewise, every 1 degrees C increase in the maximum temperature between 7 and 12 months was associated with a lower odds of allergic sensitization (OR, 0.77; 95% CI, 0.61-0.96) and asthma with allergic sensitization (OR, 0.62; 95% CI, 0.40-0.94). After adjusting for potential confounders, each episode of fever between 7 and 12 months was associated with a lower likelihood of asthma with allergic sensitization (adjusted OR, 0.33; 95% CI, 0.11-0.94) at age 6 to 7 years. CONCLUSIONS: Both the timing and intensity of childhood fevers appear to be important factors in the development of allergies and asthma.     

Modes of reinforcement and gender and culture of experimenter and subject: effects of "alien" and external reinforcement for Japanese and American men and women

In this study, we examined external and "alien" reinforcement (ER and AR. respectively) as a factor in social learning, and studied the combined effects of culture and reinforcement mode. A female (Experiment 1) and a male (Experiment 2) experimenters conducted experimental sessions. Both men and women, who grew up in the same culture as the experimenter, participated and performed the experimental task. A three-way interaction effect of experimenter gender, culture, and reinforcement mode was found on task performance. And the effect was more pronounced for a Japanese experimenter. A female and a male experimenters conducted Experiments 3 and 4, respectively; however participants this time were men and women who grew up in different cultures than the experimenter. Results indicated that the pattern of the subject gender and reinforcement mode interaction effect, when the experimenter was Japanese with American subjects, was exactly opposite to that when the experimenter was American. These experiments showed that AR was as effective for social learning as ER, and that the cultural backgrounds of experimenter and subject influenced AR and ER effectiveness.     

纳米水平分子成像与诊疗一体化研究进展与挑战

分子成像能以非侵入性的方式重现活体细胞的生理功能和生物学过程,提高疾病的早期和特异性诊断水平。纳米颗粒/材料具有物理性质可控性高、易于表面修饰、血液循环时间长和可功能化等优点,在疾病诊断与治疗中显示出巨大潜力。但如何阐明纳米材料多功能间的内在联系、解决其代谢及安全性等关键机制难题、实现纳米颗粒/材料多功能性到临床多功能...