Effects of MPP+ on catecholamine levels in adrenal glands and heart of rats

The effects of MPP⁺ (2.5–20 mg/kg) on the adrenal glands and heart were investigated in rats. At various periods after s.c. drug administration the rats were decapitated and tissue catecholamine levels were determined by means of HPLC with electrochemical detection. Adrenal dopamine (DA) levels were reduced at 2–8 h after MPP⁺ administration, but this decrease was followed by an elevation after 16 h and return to the control values after one week. Three successive injections of MPP⁺ caused a statistically significant elevation in adrenal DA, one day, with a tendency to elevation four and seven days after the last injection, whereas a severe (up to 96%) decrease in heart noradrenaline (NA) was found one day after the last injection. Seven days after the last injection a 50% depletion of NA in the heart was still observed. Pretreatment with GBR 12909 (30 mg/kg, 4 h) blocked the MPP⁺ (10 mg/kg, 2 h) induced reduction of adrenal DA levels, but at the same time GBR 12909 failed to block the effects of MPP⁺ in the heart. One day after three successive daily injections of MPP⁺ (10 mg/kg each), the DA-uptake inhibitor GBR 12909 (30 mg/kg, 6 h) could still induce an increase in adrenal DA.MPP⁺ appears to lack persistent cytotoxic action in the adrenal medulla but rather to cause a transient inhibition of DA synthesis followed by a compensatory stimulation. The inhibition can be blocked by specific inhibitor of the DA-uptake mechanism, suggesting a direct effect of MPP⁺ taken up by adrenomedullary cells. The data obtained so far do not suggest any involvement of peripheral dopaminergic nerves in the action of MPP⁺ on the adrenal medulla. The long-lasting depletion of the heart NA, however, suggests a lesion of peripheral noradrenergic nerves.Part of this work was presented at 6th International Symposium on Chromaffin Cell Biology, Marburg, Germany, 18–23 August 1991 Correspondence to: M. Kujacic at the above address     

Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

Although relatively high CO2 laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO2 laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm2, much less than that shown to sterilize in a previous study.     

Galanin gene expression declines with adulthood in the cholinergic fields of the horizontal diagonal band of male rats

The neuropeptide galanin (GAL) influences leaming and memory processes, perhaps by inhibiting cholinergic function. We recently reported that, in the rat, the nucleus of the horizontal limb of the diagonal band (HDB) exhibits the highest level of GAL mRNA coexpression by basal forebrain (BF) cholinergic neurons and, in the HDB, virtually all GAL mRNA-expressing neurons correspond to the cholinergic cell type. Since GAL gene expression is induced across puberty in many brain regions, we used in situ hybridization histochemistry and quantitative autoradiography to assess GAL gene expression across the rostro-caudal extent of the HDB in prepubertal and adult male rats and to determine whether GAL gene expression is also regulated during maturation in this BF region. Our results show that the number of GAL mRNA-expressing cells per section is significantly reduced in the HDB with adulthood. Post-hoc analysis indicated that these age-associated differences in the number of GAL mRNA-expressing cells per section could be ascribed to the rostral and central subregions of the HDB. Age-related differences in the labeling intensity of GAL mRNA-expressing neurons were also detected in the rostral and central subregions of the HDB. No age-associated differences in GAL gene expression were found in the caudal HDB subregion. These results suggest that: (1) in contrast to other brain regions, GAL gene expression in the cholinergic BF may be negatively regulated by factors concomitant with puberty; and (2) the inhibition of cholinergic function by cosecreted GAL may be enhanced prior to puberty within cholinergic neurons of the rostral and central aspects of the HDB.     

还原型谷胱甘肽和L-NAME对体外培养的脊髓运动神经元的影响

目的 :探讨还原型谷胱甘肽 (GSH)和L NAME对体外培养的脊髓运动神经元的保护作用。方法 :不同浓度的GSH和L NAME作用于脊髓运动神经元 ,3d后计算存活率。并测量存活率高的两组和对照组的免疫细胞化学标本的神经元形态学指标。结果 :GSH 10mmol·L-1和L NAME 1× 10 -3 mol·L-1组存活率最高。两实验组轴突长度、树突总长度、树突分叉点数目和胞体面积高于对照组。结论 :抗氧化剂和NOS抑制剂可以提高脊髓运动神经元的存活率 ,促进神经元生长     

正常成人脑海马区多潜能神经前体细胞的体外分离鉴定

目的 从正常成人脑海马分离鉴定多潜能神经前体细胞并探讨体外培养条件.方法 材料取自8例非神经系统疾病的死亡者.分离正常成人脑海马细胞,在培养基中添加生长因子体外培养.通过细胞培养成球和BrdU染色鉴定培养细胞的增殖能力.利用免疫细胞化学三标染色来鉴定分化神经细胞的表型.结果 从正常人海马分离的细胞培养2周时,开始增殖成簇,致一个月时,形成细胞球,这些细胞能与BrdU结合,并能在体外分化成神经系统不同谱系的细胞.结论 与在啮齿类动物和猴的研究中结果一致,从正常成人脑海马区分离的细胞是多潜能神经前体细胞.     

腹腔镜卵巢子宫内膜异位囊肿剔除术对卵巢控制性超促排卵的影响

目的探讨腹腔镜卵巢子宫内膜异位囊肿剔除术对卵巢控制性超促排卵(controlled ovarian hyperstimulation, COH)的影响.方法对161例(172周期)既往开腹或腹腔镜确诊的子宫内膜异位症合并不育患者行体外受精-胚胎移植术COH和助孕结局进行回顾性分析.其中42例(43周期)未行卵巢子宫内膜异位囊肿剔除术,为非囊肿剔除组;55例(59周期)曾行开腹卵巢子宫内膜异位囊肿剔除术,为开腹组;64例(70周期)曾行腹腔镜卵巢子宫内膜异位囊肿剔除术,为腹腔镜组.结果 3组间年龄、卵泡数、获卵数、受精率、优质胚胎数、移植胚胎数无显著性差异(P>0.05).非囊肿剔除组临床妊娠率41.5%(17/41),腹腔镜组33.3%(23/69),开腹组25.5%(14/55),差异无显著性(χ2=2.754,P=0.252).86例(90周期)行单侧卵巢子宫内膜异位囊肿剔除术,其中开腹组(37周期)手术侧卵巢的主导卵泡数(4.41±4.02)低于对侧卵巢(6.14±4.37)(t=-2.364,P=0.024).腹腔镜组(53周期)手术侧卵巢主导卵泡数(3.33±3.50)明显低于对侧卵巢(6.40±3.61)(t=-5.358,P=0.000).结论腹腔镜和开腹卵巢子宫内膜异位囊肿剔除术均可影响卵巢COH.     

c-myc mRNA在成釉细胞瘤中的表达

目的:研究成釉细胞瘤(AB)和牙源性角化囊肿(OKC)中c-mycmRNA的表达,探讨c-myc在AB和OKC中的发生、发展及其生物学意义。方法:使用原位杂交法检测54例AB、16例OKC和7例口腔正常黏膜(NOM)组织中c-mycmRNA的表达,并将AB按原发、复发、恶变分组,结果使用χ2检验进行统计分析。结果:AB、OKC及NOM组织中c-mycmRNA的阳性表达率分别为81.5%(44/54)、75.0%(12/16)和14.3%(1/7),3组比较有显著性差异(χ2=15.488,P<0.05)。原发组AB中c-mycmRNA的阳性表达率为71.0%,复发组为94.7%,恶变组为100.0%,伴随原发、复发、恶变,差异有显著性(χ2=16.912,P﹤0.05)。结论:c-myc表达在AB的发生、发展中有重要作用;c-mycmRNA的表达与AB的临床生物学行为有关,伴随其生物学行为变化,c-mycmRNA表达增强;提示c-myc有可能成为评价预后的有效指标。     

氧化苦参碱对人胃癌SGC-7901细胞株生长的影响

目的观察氧化苦参碱对人胃癌SGC-7901细胞株体外增殖率的影响情况。方法噻唑蓝（MTT）比色测定法确定氧化苦参碱对胃癌SGC-7901细胞存活抑制作用。结果试验浓度下氧化苦参碱对SGC-7901细胞增殖抑制作用呈剂量依赖性，当浓度为12mg／ml时，对SGC-7901增殖的抑制率最大，达到87．63％。结论氧化苦参碱对人胃癌SGC-7901细胞的增殖具有明显的抑制作用。     

LRIG1下调原代星形细胞瘤细胞增殖的机制

目的观察LRIGl蛋白表达对表皮生长因子（EGF）促肿瘤细胞增殖作用的影响，探讨LRIGl抑制肿瘤细胞增殖的机制。方法原代培养19例星形细胞瘤细胞，用原位杂交检测LRIGl的表达，用噻唑蓝（MTT）法观察EGF对培养细胞的促增殖作用，并分析培养细胞LRIGl表达和EGF干预后的细胞生长率的关系。结果（75．3±11．6）％的培养细胞表达LRIGl蛋白；EGF促进培养细胞增殖（38．0±14．8）％，EGF促细胞增殖的细胞生长率与LRIGl表达程度呈负相关。结论LRIGl蛋白可能通过抑制EGF—EGFR信号抑制肿瘤细胞的增殖。