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761.
762.
As superoxide (·O2) and hydroxyl radical (·OH) have been implicated in pathogenesis of Parkinsons disease, free radical scavenging, antioxidant, and neuroprotective agents have attracted attention as ways to prevent progression. We examined effects of zingerone, an alkaloid extracted from ginger root, on 6-hydroxydopamine (6-OHDA)-induced dopamine (DA) reduction in mouse striatum. Zingerone administration 1 h before and for 6 more days following one intracerebroventricular 6-OHDA injection prevented reductions of striatal DA and its metabolites, and increased serum ·O2 scavenging activity. Zingerone did not change activities of catalase or glutathione peroxidase in striatum or serum, or ·O2 scavenging activity in striatum. Treatment with diethyldithiocarbamate, SOD inhibitor, abolished the protective effect of zingerone against 6-OHDA-induced DA reduction. In vitro, zingerone scavenged ·O2 and ·OH and suppressed lipid peroxidation only weakly. Thus, direct antioxidant effects may be a minor component of its putative neuroprotective effect; instead, zingerone acted mainly by increasing systemic superoxide dismutase activity. Effects of zingerone treatment in this model suggest possible value in treatment of Parkinsons disease.  相似文献   
763.
Wheat omega-5 gliadin and a high m.w. glutenin subunit (HMW-glutenin) have been reported as major allergens in wheat-dependent exercise-induced anaphylaxis. A simultaneous detection of specific IgE to epitope sequences of both proteins is considered to be a reliable method for diagnosis of wheat-dependent exercise-induced anaphylaxis. However, the IgE-binding epitope of HMW-glutenin remains unknown. The aim of this study was to determine the IgE-binding epitopes of HMW-glutenin to establish a useful system of identifying patients with wheat-dependent exercise-induced anaphylaxis. For determination of IgE-binding epitopes of HMW-glutenin overlapping peptides were synthesized and reactivities of IgE Abs in the sera of patients to those peptides were analyzed. Three IgE-binding epitopes, QQPGQ, QQPGQGQQ, and QQSGQGQ, were identified within primary sequence of HMW-glutenin. Epitope peptides, which include IgE-binding sequences of omega-5 gliadin and a HMW-glutenin, were synthesized and peptide-specific IgE Abs were measured by CAP-System fluorescent enzyme immunoassay. Twenty-nine of 30 patients with wheat-dependent exercise-induced anaphylaxis had specific IgE Abs to these epitope peptides. None of the 25 sera from healthy subjects reacted to both epitope peptides. Twenty-five patients with atopic dermatitis who had specific IgE to wheat and/or gluten had very low or nonexistent levels of epitope peptide-specific IgE Abs. These results indicated that measurement of IgE levels specific to epitope peptides of omega-5 gliadin and HMW-glutenin is useful as an in vitro diagnostic method for the assessment of patients with wheat-dependent exercise-induced anaphylaxis.  相似文献   
764.
Many cases of autosomal dominant early onset familial Alzheimer's disease result from mutations in presenilin-1 (PS1). In this study, we examined the role of the PS1 homologue gene sel-12 of Caenorhabditis elegans under oxidative stress and clarified the sel-12-induced apoptosis. A genetic null allele mutant, sel-12(ar171), showed resistance to oxidative stress and prevented mitochondrial dysfunction-induced apoptosis. On the other hand, another allele mutant, sel-12(ar131), that carries a missense mutation showed a proapoptotic activity, which may be the result of a gain of function property. Also, sel-12(ar131)-induced apoptosis was ced-3- and ced-4-dependent. Dantrolene, which specifically inhibits Ca(2+) release from endoplasmic reticulum stores, prevents sel-12(ar131)-induced apoptosis. SEL-12, which is localized in the endoplasmic reticulum, may induce apoptosis through abnormal calcium release from the endoplasmic reticulum. Together, with the previous finding that human PS1 could substitute for SEL-12, these results suggest the similar involvement of PS1-inducing apoptosis under oxidative stress and mitochondrial dysfunction in the Alzheimer's Disease brain.  相似文献   
765.
Repression of bleomycin-induced pneumopathy by TNF   总被引:5,自引:0,他引:5  
Idiopathic pulmonary fibrosis is a chronic inflammatory lung disease with interstitial fibrosis. As a potent proinflammatory cytokine, TNF has been suggested to play critical roles in the pathogenesis of the human disease and its animal model, bleomycin-induced pneumopathy. However, studies using TNF-deficient mice have demonstrated that TNF also has an anti-inflammatory function. To determine the role of TNF in pulmonary inflammation induced by bleomycin, we injected bleomycin intratracheally into TNF-deficient mice. In this study, we demonstrated persistent and intense inflammation in TNF-deficient mice due to reduced apoptosis of inflammatory cells. We also showed that in TNF-deficient mice, challenge via airways with murine, but not human rTNF, efficiently eliminated inflammatory cells from the bronchoalveolar space by apoptosis, and thus promoted tissue repair of damaged lungs. Contrary to previous reports that showed that TNF was a central mediator of pulmonary inflammation, we have demonstrated that TNF is essential for repressing pulmonary inflammation in bleomycin-induced pneumopathy.  相似文献   
766.
767.
To understand molecular pathways underlying 9p21 deletions, which lead to inactivation of the p16/CDKN2A, p14/ARF, and/or p15/CDKN2B genes, in lymphoid leukemia, 30 breakpoints were cloned from 15 lymphoid leukemia cell lines. Seventeen (57%) breakpoints were mapped at five breakpoint cluster sites, BCS-LL1 to LL5, each of <15 bp. Two breakpoint cluster sites were located within the ARF and CDKN2B loci, respectively, whereas the remaining three were located >100 kb distal to the CDKN2A, ARF, and CDKN2B loci. The sequences of breakpoint junctions indicated that deletions in the 11 (73%) cell lines were mediated by illegitimate V(D)J recombination targeted at the five BCS-LL and six other sites, which contain sequences similar to recombination signal sequences for V(D)J recombination. An extrachromosomal V(D)J recombination assay indicated that BCS-LL3, at which the largest number of breakpoints (i.e. five breakpoints) was clustered, has a V(D)J recombination potential 150-fold less than the consensus recombination signal sequence. Three other BCS-LLs tested also showed V(D)J recombination potential, although it was lower than that of BCS-LL3. These results indicated that illegitimate V(D)J recombination, which was targeted at several ectopic recombination signal sequences widely distributed in 9p21, caused a large fraction of 9p21 deletions in lymphoid leukemia.  相似文献   
768.
769.
770.
Behaviour of microbial populations responsible for degrading n-alkanes, a major component of crude oil, was monitored during crude oil degradation in a sea-water microcosm by both traditional colony culturing and molecular techniques. A DNA extraction method applicable to crude oil-amended sea-water samples was developed to obtain DNA applicable to most probable number (MPN) polymerase chain reaction (PCR). The population of alkane-degrading bacteria responsible for degradation of n-alkanes in a crude oil-amended microcosm altered, so that shorter alkanes were degraded first by alkane-degrading bacteria possessing alkane hydroxylase genes from group I (Kohno et al., 2002, Microb Environ 17: 114-121) and longer ones afterwards by those possessing alkane hydroxylase genes from group II. Thus, the degradation mechanism of the n-alkanes can be clarified during crude oil degradation. Application of the method of detecting different types of alkane-catabolic genes, as shown in the present study, enabled bacterial groups preferring alkanes of either shorter or longer chain lengths to be enumerated selectively.  相似文献   
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