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121.
Phage display technology represents a powerful tool for the identification of peptides reacting with disease-related antibodies present in human sera. The application of this technology to type 1 diabetes could provide a set of novel reagents for diabetes prediction and could also lead to the identification of novel autoantigens or even of environmental factors possibly causing the disease. In the present study, sera of prediabetic and high risk individuals were used to select candidate peptides from phage-displayed random peptide libraries. Diabetes specific phage clones were then identified from these through screening and counter screening, using sera from diabetic and non-diabetic individuals. The results presented in this paper demonstrate the feasibility of this methodology to identify peptides reacting preferentially with antibodies present in the serum of diabetic patients. 相似文献
122.
1. The review summarizes the most important data known so far on chemistry, pharmacodynamics, toxicology and clinics of the investigational agent, pyridoindole stobadine. 2. Stobadine was shown to be able to scavenge hydroxyl, peroxyl and alkoxyl radicals, to quench singlet oxygen, to repair oxidized amino acids and to preserve oxidation of SH groups by one-electron donation. These effects originated from its ability to form a stable nitrogen-centered radical on indole nitrogen. Consequently, it was able to diminish lipid peroxidation and protein impairment under oxidative stress. 3. In various in vitro and in vivo animal models, stobadine was shown to diminish the impairment of the myocardium induced by mechanisms involving reactive oxygen species (e.g., myocardial infarction, hypoxia/ reoxygenation, catecholamine overexposure). 4. The neuroprotective effect of stobadine was demonstrated in a series of in vivo and in vitro models (brain in situ, brain slices, spinal cord, autonomic ganglia, etc.) during ischemia/reperfusion and hypoxia/ reoxygenation or in the presence of chemical systems generating free oxygen radicals, and so forth. Stobadine improved animal survival rate and synaptic transmission recovery, maintained SH tissue level and diminished lipid peroxidation as well as impairment of Ca-sequestering intracellular systems. 5. Oxidation of low-density lipoproteins (LDLs), which plays a major role in the development of atherosclerosis, was decreased by stobadine in vitro. Both lipid and protein (apo B) components of LDL were protected against Cu(2+)-induced oxidation by this agent. 6. Stobadine proved to be an effective protectant in models of free radical pathology in vivo, such as cyclophosphamide-, MNNG- or 60Co-induced mutagenesis and alloxan-induced hyperglycemia. 7. Besides other remarkable pharmacodynamic effects, stobadine exerts antidysrhythmic, local anesthetic, alpha-adrenolytic, antihistaminic, myorelaxant and antiulcerogenic actions. 8. Pharmacokinetic analyses demonstrated that stobadine was readily absorbed from the gastrointestinal tract. Thanks to its balanced lipo-hydrophilic properties, it was distributed over both water and lipid phases in biological tissues. It was shown to easily penetrate the blood-brain barrier. 9. Acute, subchronic and chronic toxicity studies in several animal species, as well as numerous analyses of embryotoxicity, teratogenicity, mutagenicity and genotoxicity, revealed only a negligible toxic potential of this agent. 10. Phase-one clinical study demonstrated safety of the compound. Only slight side effects--namely, a slight hypotension and a slight sedative effect--were observed subsequent to the highest dose used. In phase-two clinical study, the patients with angina pectoris treated for 4 weeks with stobadine showed a significant decrease in the frequency of anginal attacks, in the number of self-administrations of sublingual nitroglycerine and in plasma lipoprotein, cholesterol and triglyceride levels. A slight decrease in systolic and diastolic blood pressure also was observed. 11. It is suggested that stobadine may be considered a contribution to the search for new effective cardio- and neuroprotectants based on antioxidant or free radical scavenging mechanisms of action. 相似文献
123.
Exposure of cardiac myocytes from adult rat ventricles to the highly selective, high affinity sigma receptor ligands 1S,2 R-cis-N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)-cycloh exylamine (BD-737) (0.1-100 nM) and N-[2-(3,4-dichlorophenyl)ethyl]-N,N',N'-trimethylethylenediamine (BD-1047) (0.01-10 nM), caused potentiation of electrically-evoked amplitudes of contraction and Ca2+ transients, while exposure to 100 nM BD-1047 caused attenuation of these amplitudes. In addition, BD-737 (1-100 nM) and BD-1047 (10-100 nM) caused an increase in the incidence of spontaneous twitches. These effects were inhibited when the incubation with BD-737 was done in the presence of the phospholipase C inhibitor, neomycin, or after pre-incubation with thapsigargin or caffeine which deplete the sarcoplasmic reticulum Ca2+ stores. Inositol 1,4,5-trisphosphate (IP3) production in cardiac myocytes was determined by the IP3 binding protein assay. Both substances caused an increase in the intracellular concentration of IP3. BD-737 caused a rapid transient increase to 3.2-fold in 1 min and stabilization at 2.1-fold of control thereafter. BD-1047 caused a gradual increase reaching 4.4-fold after 5 min. The results suggest that the effects of these sigma receptor ligands on contractility and spontaneous contractions are mediated by activation of phospholipase C and elevation of intracellular IP3 level. 相似文献
124.
Several hypotheses have been advanced in recent years to understand difficulties in agrammatic patients. Some of them are of a structural kind, as the deficiency is said to lie in some of the linguistic system components. Others are of a functional type, as it is stated that the problem of these patients lies in the loss of processing capacity. Using the existence of a syntactic type of structure in Spanish, that active sentences do not follow the canonical S-V-O order, we will try to prove in this article whether agrammatic patients' problems are due to memory span loss or to one of the syntactic process mechanisms. To this end, the performances of three groups of patients are contrasted. Agrammatic, anomic, and normal Spanish speakers are given several tasks of sentence-picture matching and tests of memory span. Results show that agrammatic patients have specific difficulties processing certain syntactical structures; however, their memory deficiencies are not more pronounced than in other patients. It can be concluded, therefore, that the deficiencies of agrammatic patients are of a structural character rather than due to memory span loss. 相似文献
125.
The synthesis of the murein precursor lipid I is performed by MraY. We have shown that mraY is an essential gene for cell growth. Cells depleted of MraY first swell and then lyse. The expression of mraY DNA in vitro produces a 40-kDa polypeptide detectable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 相似文献
126.
R Caplan S Arbelle W Magharious D Guthrie S Komo WD Shields S Chayasirisobhon R Hansen 《Canadian Metallurgical Quarterly》1998,40(12):805-811
Structured psychiatric interviews were administered to 60 children with complex partial seizure disorder (CPS), 40 children with primary generalized epilepsy with absences (PGE), and 48 control children, aged 5 to 16 years. Significantly more patients with epilepsy had psychiatric diagnoses compared with the control children. There were no statistically significant differences, however, in the number of patients with CPS and PGE with psychiatric diagnoses. Other than a schizophrenia-like psychosis found only in the patients with CPS, the two groups of patients had similar psychiatric diagnoses. The presence of psychopathology was related to significantly lower IQ scores and socioeconomic status, but not to seizure-related factors. These findings suggest that the psychopathology of children with CPS and PGE reflects different subtle neuropsychological deficits. 相似文献
127.
The role of androgens and the androgen receptor (AR) in the development and progression of breast cancer is poorly understood. To further define a potential model for androgen action in breast cancer, MDA-MB-453 cells, which express AR in the absence of oestrogen receptors and progesterone receptors, were further characterised in terms of AR expression and androgen responsiveness. High level expression of AR was confirmed by northern blot analysis, radioligand binding and immunocytochemistry, and could not be accounted for by AR gene amplification. Three endogenous androgen-responsive genes (fatty acid synthetase, gross cystic disease fluid protein of 15 kDa and prolactin receptor) and a transfected reporter gene, containing an androgen-responsive element, were induced following androgen administration. A synthetic androgen, mibolerone, induced moderate (27% above control) stimulation of MDA-MB-453 cell proliferation, which was abrogated by the simultaneous administration of the synthetic androgen antagonist, anandron, demonstrating that the effect was AR-mediated. In summary, MDA-MB-453 cells express high levels of functional AR, and thus provide a valuable in vitro model for further studies on androgen regulation of gene expression, and perhaps cell proliferation in breast cancer. 相似文献
128.
129.
130.
WD Fraser 《Canadian Metallurgical Quarterly》1997,57(5):212-214