ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

SMatrix metalloproteinase-9 (MMP-9) and its specific inhibitor, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), were analysed by enzyme-linked immunosorbent assay (ELISA) and by zymography in serum and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In contrast to patients with inflammatory diseases, MMP-9 levels were not elevated in CSF of ALS patients. In serum, however, compared to healthy donors, MMP-9 was significantly (p= 0.0003) increased up to levels as high as those of viral meningoence-phalitis (VM) or bacterial meningitis (BM) patients. MMP-9 levels remained elevated during long-term observation of ALS patients. In the absence of an inflammatory response, the results indicate that the increase of MMP-9 in serum of ALS patients might be caused by upregulation of MMP-9 in denervated muscles or in degenerating peripheral nerves following motor neurone loss.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Deficiency of orexin, a newly discovered hypothalamic peptide, is thought to lead to abnormal sleepiness and cataplexy in both human narcolepsy and animal models of the disease. As the POA contains extensive orexin terminals and is established as a sleep/arousal regulatory site, we evaluated a hypothesis that this site is a target for the arousal-inducing effects of orexin. Orexin-A was microinjected into lateral preoptic area (IPOA) and the effects on sleep–wakefulness and brain temperature were studied. Compared to saline vehicle control, orexin-A induced an increase in wakefulness for 70 min and suppressed all sleep stages, especially SWS2 and REM for 80 and 90 min, respectively. Brain temperature was not differentially affected by orexin-A compared to saline control. The orexin-induced arousal and REM suppression are consistent with the orexin-deficiency model of narcolepsy. Our results suggest that the IPOA orexin terminal field or adjacent structures may be a locus of arousal regulation by this peptide and a substrate of sleep-wake regulatory deficits in narcolepsy.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

We examined spinal cord sections from Guamanian Chamorros with or without amyotrophic lateral sclerosis or parkinsonism–dementia complex using immunohistochemistry and antibodies to epitopes that span the length of tau to characterize the tau epitope profile of neurofibrillary tangles in these spinal cords. Most (16/20) spinal cords, including some from Chamorros without documented clinical disease, contained tangles with a tau epitope profile similar to the tangles found in the forebrain and brain stem of these patients.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Two GABABreceptor subunits have been cloned: GABAB1and GABAB2. In this study we investigate the coupling of recombinant GABABreceptors to calcium channels in differentiated NG108–15 cells, which exhibit many similarities to neurones but in which functional GABABreceptors are normally absent. Transfection of GABAB1and GABAB2subunit cDNAs enables baclofen-mediated inhibition of different calcium channel subtypes and a component of this modulation is voltage-dependent. When transfected individually, GABAB2, but not GABAB1, is able to enhance calcium current inhibition over background levels. Further, an antisense oligodeoxynucleotide to GABAB1reduces the average functional response in cells transfected with GABAB2alone. Assuming that the functional receptor is heteromeric, this suggests that GABAB1, but not GABAB2, is expressed endogenously in NG108–15 cells.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Ischemia/reperfusion (I/R) results in a robust induction of cyclooxygenase (COX)-2 in the newborn brain via unknown mechanisms, but glutamate release and activation of KA receptors may be involved. We examined effects of local KA (3–300 umol/l for 10 min) treatment on cortical COX-2 expression in anesthetized piglets using a closed cranial window. Treated and corresponding control tissue samples were collected 0.5–10 h after treatment. COX-2 mRNA and protein levels were assessed using RNase protection assay and immunohistochemistry, respectively. KA elicited reproducible dose-dependent increases in cortical COX-2 mRNA unaffected by indomethacin or NG-nitro-L-arginine methyl ester pretreatment. COX-2 mRNA levels were elevated at 30 min, peaked at 2 h, but remained enhanced for up to 10 h after KA. Neuronal COX-2 immunoreactivity was also enhanced compared with the control side in all cortical layers 8 h after KA. In summary, activation of KA receptors may be involved in the neuronal induction of COX-2 after I/R in the newborn.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Ciliary neurotrophic factor (CNTF) acts through the JAK/STAT signal transduction pathway. However, the rapid action of CNTF cannot readily be explained by reference to this pathway. Using the fluorophore, Fura 2-AM, and fluorescence imaging, the effect of CNTF on glutamate-induced increases in hippocampal intraneuronal free Ca2+([Ca2+]i) was investigated. Glutamate induces a rapid increase in [Ca2+]i. Incubation of hippocampal neurons with CNTF for 5 min inhibited the glutamate-induced increase in [Ca2+]i. In the absence of glutamate, CNTF had no effect on [Ca2+]i. Pertussis toxin (PTX), a G-protein antagonist, partially blocked the effect of CNTF. This suggests that CNTF may act via an alternative signal transduction pathway besides the generic JAK/STAT pathway.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Biochemical studies have shown that prohormone convertases PC1, PC2 and PC5A all have the capacity to process, with different specificities, the neurotensin/neuromedin N precursor, pro-NT/NN. A previous study from our laboratory has demonstrated that in rat brain, both PC2 and PC5A may be co-expressed with NT, lending support to a physiological implication of these two enzymes in the endoproteolytic maturation of pro-NT/NN. In the present study, we sought to determine whether PC1 might also be involved in this process by comparing the immunohistochemical distribution of the enzyme with that of NT in both singly labeled and dually labeled serial brain sections. PC1 was found to co-localize extensively with NT throughout the rat neuraxis. However, there were important regional variations in the proportion of NT neurons co-expressing PC1. Furthermore, this proportion was negatively correlated with that of NT neurons expressing PC5, suggesting that PC1 may serve as an alternative to PC5A for processing pro-NT/NN in mammalian brain.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Calcium channel α2δ subunit is a glycosylated structural subunit consistent of the α2subunit and the δ peptide. Previous studies have indicated distinctive α2subunit expression in rat spinal cord and dorsal root ganglia (DRG). This study examined whether differential glycosylation underlies the molecular basis of distinct α2δ subunits. The migration patterns of deglycosylated α2subunits from rat spinal cord, DRG, brain and skeletal muscle were compared in Western blots. The data reported indicate that there are two forms of the α2subunit in DRG that are different from the α2subunit in other tissues examined, at least at the glycosylation level. Thus, post-translational modification may be important in tissue specific and functional expression of the α2δ subunit.

ISSN:0959-4965    

出版商:OVID    

年代:2000

数据来源: OVID