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The aim of the current study was to demonstrate glycation of beta L-, beta S- and gamma-crystallins in the young bovine lens. To establish which of the crystallins are glycated and where they are located in the lens, we carried out microsectioning of the lens, followed by isoelectric focusing (IEF). Four bovine lenses of 1.183 +/- 0.070 years were frozen-sectioned into equator and 11 layers. Water-soluble crystallins were separated by IEF and stained: (1) with Coomassie brilliant blue for proteins; (2) with the lectin concanavalin A, followed by horseradish peroxidase and diaminobenzidine, for glycated proteins. Experiments were performed with crystallins and proteins in native form, in the absence of denaturants. The crystallins were separated by IEF into alpha-crystallins of high molecular weight (HM), alpha L-, beta H-, beta L-, beta S- and gamma-crystallins. In the lectin staining experiments, only HM, beta L-, beta S- and gamma-crystallins were positive, whereas the alpha L- and beta H-crystallins were negative. Contrary to the glycated gamma-crystallins in the lens nucleus, the beta S- and beta L-crystallins were predominantly glycated in the anterior cortex and to a somewhat lower extent also in the posterior cortical regions. The degree of glycation (total densitometric readings of lectin-stained bands/Coomassie-blue-stained bands) is as follows: total gamma-crystallins 2.44, beta S-crystallins 0.77 and beta L-crystallins 0.28. Though glycation in the bovine lens is very low, lectin staining is sufficiently sensitive to detect the various glycated crystallins. The degree of glycation of gamma-crystallins was 3 times higher than that of beta S-crystallins and 9 times higher than that of beta L-crystallins. 相似文献
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CP Tensen KJ Cox JF Burke R Leurs RC van der Schors WP Geraerts E Vreugdenhil H Heerikhuizen 《Canadian Metallurgical Quarterly》1998,10(11):3409-3416
Neuropeptide Y is an abundant and physiologically important peptide in vertebrates having effects on food intake, sexual behaviour, blood pressure and circadian rhythms. Neuropeptide Y homologues have been found in invertebrates, where they are very likely to play similar, important roles. Although five neuropeptide Y-receptor subtypes have been identified in mammals, none has been reported from invertebrates. Here we describe the cloning of a neuropeptide Y-receptor from the brain of the snail Lymnaea stagnalis. The identity of the receptor was deduced by expressing the neuropeptide Y-receptor-encoding cDNA in Chinese Hamster Ovary cells, which were subsequently challenged with size-fractionated Lymnaea brain extracts. An active peptide, selected on the basis of its ability to induce changes in cAMP levels, was purified to homogeneity, analysed by mass spectrometry and amino acid sequence determination, and turned out to be a Lymnaea homologue of neuropeptide Y. 相似文献
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KH Yeh MT Lin DT Lin JL Tang LT Lui JF Lin YS Chang AL Cheng SC Yu KJ Chang YC Chen 《Canadian Metallurgical Quarterly》1998,49(3):237-244
BACKGROUND: Epidemiologic studies are necessary to determine the prevalence of allergic diseases. This varies widely depending on allergen preparations and patients studied. OBJECTIVE: To investigate the prevalence of atopic disease, skin test reactivity, total and specific IgE to common allergens, and other variables in a sample of students from Málaga, southern Spain. METHODS: Three hundred sixty-five students (age 17.9 +/- 1.18) were interviewed by an allergist. Skin prick tests were performed with Dermatophagoides pteronyssinus, Artemisia vulgaris, Plantago lanceolata, Chenopodium album, Olea europaea, Phleum pratense, Parietaria judaica, Cynodon dactylon, Alternaria tenuis, and cat dander. Total and specific IgE to D. pteronyssinus, Olea, and Parietaria were determined. RESULTS: Of all subjects studied, 19.9% suffered from rhinoconjunctivitis, 4.1% rhinoconjunctivitis plus asthma, 3.1% asthma alone, and 0.8% atopic dermatitis; 46.4% had a positive skin test to at least one allergen (28.2% to D. pteronyssinus, 20.4% to Olea, 13.8% to Phleum); and 43% had total IgE > 100 kU/L and 44.7% a family history of atopy. Allergic symptoms were strongly associated with skin test positivities and family allergic history. Patients with asthma or skin prick test positive had higher total IgE values than others (P < .01). There was a significant correlation between specific IgE values and wheal size in skin test. CONCLUSIONS: Our findings confirm the high prevalence of atopic diseases, and the close relationship of skin tests reactivity (or presence of specific IgE) to allergens with symptoms of asthma and rhinitis. The presence of a family history of allergic diseases influences the development of positive skin tests and atopic illness. Dermatophagoides pteronyssinus and pollen of Olea europaea were found to be the most common allergens. 相似文献
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DS Karanewsky X Bai SD Linton JF Krebs J Wu B Pham KJ Tomaselli 《Canadian Metallurgical Quarterly》1998,8(19):2757-2762
A systematic study of interleukin-1 beta converting enzyme (ICE, caspase-1) and caspase-3 (CPP32, apopain) inhibitors incorporating a P2-P3 conformationally constrained dipeptide mimetic is reported. Depending on the nature of the P4 substituent, highly selective inhibitors of both Csp-1 or Csp-3 were obtained. 相似文献
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JW Jones SE Schmidt BW Richman KM Itani KJ Sapire MJ Reardon 《Canadian Metallurgical Quarterly》1998,78(5):705-727
In conclusion, surgical myocardial revascularization has utilized diverse methods to increase blood flow to the starving myocardium. These methods initially used the microcirculation as the portal to reach myocytes until angiography showed that the obstructions were macrovascular. This resulted in a 30-year era of direct attack on the coronary blockages by coronary bypass. Surgical conduits unfortunately have longevity considerably less than that of native arteries and are limited in number. Alternative conduits, both biologic and prosthetic, have not yet proved to have the same clinical results as the ITA. More patients are living long enough to have the extensiveness of their disease exhaust conventional therapies. Newer therapy, restricted thus far to untreatables, revisits the microcirculation by making laser channels. These many innovative procedures have benefited hundreds of thousands of patients. They emerged from the probity and innovation of many individual surgeons. 相似文献
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The degradation pattern of the synthetic absorbable polyester is thought to occur from the center of the material outward, and the bulk degradation is therefore attributed largely to the chemical composition of the material. It was hypothesized that this pattern might be altered by changing the morphology of the material, i.e., by introducing molecular orientation into the system. A new solid state uniaxial orientation (SS-UO) process was used to orient two types of lactide polymer films. The films were exposed to a phosphate buffered solution, then chemically, mechanically, and visually analyzed after predetermined times. This paper explores the results of flexural testing which will be later correlated with microscopic degradation events, as part of the larger degradation study. The results show that, while orientation does not have an overall significant effect on the flexural modulus, there is a significant material/orientation interaction. 相似文献