胃癌CD44V6的表达与浸润转移的关系

目的：研究胃癌ＣＤ４４Ｖ６的表达与肿瘤浸润、淋巴结转移的关系。方法：应用ＣＤ４４Ｖ６单克隆抗体,用Ｓ－Ｐ法免疫组织化学技术进行观察。结果：７０例胃癌中２４例（３４．３％）ＣＤ４４Ｖ６阳性。淋巴结转移组ＣＤ４４Ｖ６阳性率４５．７％明显高于无转移组的１２．５％（Ｘ＾２＝１１．２４,Ｐ〈０．０１）;结论：提示ＣＤ４４Ｖ６的表达可作为预测胃癌转移的较好指标。     

急性白血病患者MGMT基因突变的研究

目的研究甲基鸟嘌呤－脱氧核糖核酸－甲基转移酶（ＭＧＭＴ）基因突变与急性白血病发病的关系。方法应用聚合酶链反应－单链构象多态性（ＰＣＲ－ＳＳＣＰ）技术对６２例急性白血病中ＭＧＭＴ基因进行了突变分析。结果ＭＧＭＴ基因突变在急性白血病中为１４．５％。结论急性白血病中存在ＭＧＭＴ基因突变,其在急性白血病的发生与发展中起到一定作用。     

类风湿性关节炎患者血清IL-6、TNF水平变化及其意义探讨

采用细胞生物学方法测定类风湿性关节炎（ Ｒ Ａ）１４ 例血清 Ｉ Ｌ－ ６ 、 Ｔ Ｎ Ｆ 水平,均显著高于正常对照组（ Ｐ＜ ０ ．００１） 。相关分析显示 Ｉ Ｌ－ ６ 与 Ｔ Ｎ Ｆ 水平变化呈正相关（ Ｐ＜ ０ ．０１） , Ｉ Ｌ－ ６ 、 Ｔ Ｎ Ｆ 与血沉亦呈正相关（ Ｐ＜０ ．０５） 。认为, Ｉ Ｌ－ ６ 、 Ｔ Ｎ Ｆ 参与 Ｒ Ａ 的发病,两者在致病中有协同相同;其水平变化与 Ｒ Ａ 的活动性及血沉相关。     

Unilateral dopamine depletion paradoxically enhances amphetamine-induced Fos expression in basal ganglia output structures

The ability of amphetamine to induce expression of the immediate early gene protein, Fos, was examined by immunocytochemistry in animals with unilateral 6-hydroxydopamine lesions of the nigrostriatal bundle. Amphetamine induced Fos expression in the globus pallidus (GP) on the intact side of the brain, but this response was greatly attenuated on the dopamine-depleted side. In contrast, amphetamine induced little Fos expression in the entopeduncular nucleus (EPN) and the substantia nigra pars reticulata (SNpr) on the intact side of the brain, but resulted in pronounced expression in these structures on the lesioned side. These findings demonstrate that unilateral dopamine depletion results in a pathophysiological state in which some responses to amphetamine are attenuated while others are paradoxically potentiated. One explanation of these effects is that amphetamine may indirectly activate excitatory inputs to the SNpr and the EPN on both sides of the brain. On the intact side, these effects would be opposed by the simultaneous activation of inhibitory pathways arising in the striatum and the GP, with the result that little Fos expression would be seen. On the dopamine-depleted side, however, engagement of these inhibitory pathways would be attenuated and the unopposed effects of the excitatory inputs mobilized by amphetamine would result in exaggerated Fos synthesis.     

Effect of dopamine denervation and dopamine agonist administration on serine phosphorylation of striatal NMDA receptor subunits

Sensitization of striatal N-methyl-d-aspartate (NMDA) receptors has been implicated in the pathogenesis of the response alterations associated with dopaminomimetic treatment of parkinsonian animals and patients. To determine whether serine phosphorylation of NMDA receptor subunits by activation of Ca2+/calmodulin-dependent protein-kinase II (CaMKII) contributes to this process, we examined the effects of unilateral nigrostriatal ablation with 6-hydroxydopamine and subsequent treatment with levodopa, SKF 38393 (D1-preferring dopamine agonist), or quinpirole (D2-preferring agonist) on motor responses and phosphorylation states. Three weeks of twice-daily levodopa administration to rats shortened the duration of their rotational response to levodopa or SKF 38393 challenge, but prolonged the duration of quinpirole-induced rotation. At the same time, levodopa treatment elevated serine phosphorylation of striatal NR2A (p<0.02), but not that of NR2B subunits, without associated changes in subunit protein levels. Chronic treatment with SKF 38393 increased NR2A (p<0.0001) but decreased NR2B (p<0.004) serine phosphorylation. In contrast, chronic quinpirole treatment had no effect on NR2A but increased NR2B phosphorylation (p<0.0001). The acute intrastriatal injection of the CaMKII inhibitor KN93 (1.0 micrograms) not only normalized the levodopa-induced motor response alterations but also attenuated the D1 and D2 receptor-mediated serine phosphorylation of NR2A and NR2B subunits, respectively (p<0.02). These results suggest that a CaMKII-mediated rise in serine phosphorylation of NMDA receptor subunits induced by intermittent stimulation of D1 or D2 dopaminergic receptors contributes to the apparent enhancement in striatal NMDA receptor sensitivity and thus to the dopaminergic response plasticity in levodopa-treated parkinsonian rats.     

Acute interactions between -DOPA and the neurotoxic effects of 1-methyl-4-phenylpyridinium or 6-hydroxydopamine in mice

We have compared the effects of an i.p. pretreatment with L-DOPA (200 mg/kg) associated with benserazide (25 mg/kg) on neurotoxic effects of either 6-hydroxydopamine (6-OHDA) (50 microg, 10 microl per mouse) or 1-methyl-4-phenylpyridinium (MPP+) (17.5 microg, 10 microl per mouse). The striatal dopamine (DA) content, the vesicular monoamine transporter (VMAT2) density, as well as the hypothalamic norepinephrine (NE) content were measured 8 days after treatments. The L-DOPA-benserazide pretreatment worsened by 65% the 6-OHDA-induced depletion in striatal DA. On the contrary, it reduced by 42% the MPP+-induced depletion in striatal DA and by 54% the MPP+-induced decrease in VMAT2 density. It was noticed that the L-DOPA-benserazide pretreatment did not modify the marked decrease in hypothalamic NE content induced by 6-OHDA.     

Ultrastructural confirmation of neuronal protection by melatonin against the neurotoxin 6-hydroxydopamine cell damage

6-Hydroxydopamine (6-OHDA) is a neurotoxin used in the induction of experimental Parkinson's disease in both animals and cultured neuronal cells. Biochemical and molecular approaches showed previously that low doses of 6-OHDA induced apoptosis in PC12 cells, while high doses of this neurotoxin induced necrosis. Melatonin has been shown to protect against the neuronal programmed cell death induced by 6-OHDA, although it was not able to prevent the massive necrotic cellular death occurring after the addition of high doses of the neurotoxin. In the present work, we demonstrate by ultrastructural analysis that although low doses of 6-OHDA induced apoptosis in PC12 cells, it also damaged the non-apoptotic cells, morphologically corresponding this damage to incipient and reversible necrotic lesions. When the doses of the neurotoxin increase, there are still apoptotic cells, although most of the cells show necrotic irreversible lesions. We also found that melatonin partially prevents the incipient necrotic lesions caused by low doses of 6-OHDA. The fact that melatonin was shown in previous work to prevent apoptosis caused by low doses of 6-OHDA, but not necrosis induced by high doses of the neurotoxin, seemed to indicate that this agent is only able to protect against apoptosis. However, our present results, melatonin preventing also the incipient necrotic neuronal lesions, suggest that this hormone may provide a general protection against cell death, suggesting that higher doses should be tried in order to prevent the necrotic cell death induced by high doses of the neurotoxin.     

Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: effects on hippocampal type II corticosteroid receptors

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive -amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [³H]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of -amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.     

Cellular distribution of the NMDA receptor subunit NMDAR1 in fetal ventral mesencephalon transplants in the dopamine-depleted striatum of a rat

Immunohistochemistry was performed to demonstrate the cellular distribution of N-methyl-D-aspartate (NMDA) receptor subunit NMDAR1 in the intrastriatal grafts of a rat model of Parkinson's disease. Unilateral 6-hydroxydopamine (6-OHDA) lesions of the mesostriatal pathway were produced in young adult female rats. Neural transplantation was performed with fetal ventral mesencephalon (VM) tissue (at embryonic day 15) 3 weeks after the 6-OHDA lesions. In the fetal VM in which the tyrosine hydroxylase (TH) immunoreactivity was intensely observed, no NMDAR1 subunit immunoreactivity was detected. Immunopositive cells of NMDAR1 were densely distributed in the intact SNc contralateral to the lesions, in which intense immunoreactivity for TH was observed. In contrast, the cells positive for NMDAR1 in the SNr were scattered. The immunoreactivity for NMDAR1 was markedly decreased in the SNc, but not in the SNr on the lesioned side. Double immunostaining revealed that most TH-positive cells in the SNc showed moderate NMDAR1 immunoreactivity. Within the intrastriatal fetal VM grafts containing TH-positive cells, NMDAR1-positive cells tended to locate homogeneously within the grafts. These were composed of various cell sizes and shapes, but they were mainly medium-sized and aspiny cells. Double immunostaining revealed that a part of the TH-positive cells in the grafts was also immunopositive for NMDAR1. Taken together with our previous studies, it is suggested that both dopaminergic neurons and nondopaminergic neurons in the VM transplants appear to be modified functionally by glutamatergic afferents via various glutamate receptors, including NMDAR1.     

Pergolide potentiates L-DOPA-induced dopamine release in rat striatum after lesioning with 6-hydroxydopamine

Summary. We used intrastriatal microdialysis to study the effect of pergolide, a D₁/D₂ dopamine (DA) receptor agonist on biotransformation of exogenous L-DOPA in hemi-Parkinsonian rats. DA and metabolites were assayed by microbore liquid chromatography. Pergolide (50 μg/kg, i.p) caused a 67% and 87% decrease in striatal EC levels of DA in intact and denervated striatum respectively. In intact striatum but not in denervated striatum, pergolide decreased EC levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) (53% and 42% decrease, respectively). L-DOPA (100 mg/kg, i.p.) produced significant increase in EC levels of DA, DOPAC and HVA in intact and denervated striatum with and without local perfusion of 10⁻⁴ M pergolide. In denervated striatum, L-DOPA-induced DA increase was significantly higher in rats with pergolide. Our results suggest that, in an animal model of Parkinson's disease, pergolide in association with L-DOPA favors the restoration of striatal EC DA levels. Received April 24, 1998; accepted July 23, 1998