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101.
A novel class of major histocompatibility complex class I (MHC-I) ligands containing an N-hydroxy-amide bond was designed on the basis of the natural epitope SIINFEKL, and synthesized on solid phase. The capacity of these compounds to bind to the MHC-I molecule H-2Kb and to induce T cell responses was analysed in comparison with the corresponding glycine containing variant of SIINFEKL. Binding to the MHC molecule was diminished by the N-hydroxy group at positions 2 and 3 of the oligomer and improved in the case of positions 4, 5, 6 and 7. No change was seen for position 1. The efficacy of T cell stimulation was strongly reduced by the modification of all positions except for position 1. A complete loss of activity was found for the N-hydroxy variant in positions 4 and 6. N-Hydroxy amide-containing peptides displayed an enhanced stability to enzymatic degradation. This new class of MHC ligand can become instrumental as immunomodulatory reagent in various disease situations. © 1998 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
102.
Lucas R Lopes Vitor AR Miranda Rodrigo A Goes Gabriel GA Souza Giuliana R Souza Jessica CS Rocha Victor RA Cossich Jamila A Perini 《Biology of sport / Institute of Sport》2021,38(4):703
The COVID-19 pandemic has presented significant challenges and implications for the sports community. Thus, this study aimed to describe the prevalence of COVID-19 in Brazilian athletes and identify the epidemiological, clinical, athletic, life and health factors associated with the disease in these individuals. A cross-sectional study was performed involving 414 athletes from 22 different sports using an online questionnaire from August to November 2020. The association between the athletes’ characteristics and COVID-19 was evaluated using a logistic regression model. The prevalence of COVID-19 was 8.5%, although only 40% of athletes reported having been tested. Being under 27 years of age (3-fold), having children (~5-fold), having a teammate test positive for COVID-19 (2.5-fold), and smoking (14-fold) were associated with a possible higher risk of disease. Almost 20% of athletes self-reported musculoskeletal injuries during the period of the pandemic that was studied. Athletes with a university education (P = 0.02), a profession other than sports (P < 0.001), those from a low-income family (P = 0.01), and public health system users (P = 0.04) were significantly less frequently tested for COVID-19, whereas international competitors, athletes who received a wage, and athletes who had a teammate who tested positive for COVID-19 were 2-, 3-, and 15-fold more likely to be tested for COVID-19, respectively. Approximately 26% of the athletes who tested negative or were untested reported more than three characteristic COVID-19 symptoms, and 11% of athletes who tested positive for COVID-19 were asymptomatic. The identification of modifiable (have children, smoking, and teammates positively tested) and non-modifiable (age under 27 years) factors related to COVID-19 in athletes can contribute to implementing surveillance programmes to decrease the incidence of COVID-19 in athletes and its negative impacts in sports. 相似文献
103.
Alessandro Venditti Claudio Frezza Fabio Sciubba Sebastiano Foddai Mauro Serafini Armandodoriano Bianco 《化学与生物多样性》2017,14(3)
The analysis of metabolites contained in the male cones of Wollemia nobilis was investigated for the first time in this study. Several diterpenoids of chemosystematic relevance were recognized for the first time from the genus and/or from the Araucariaceae family, namely isocupressic acid ( 1 ), acetyl‐isocupressic acid ( 2 ), methyl (E )‐communate ( 3 ) and sandaracopimaric acid ( 4 ). All these terpenoids are also endowed with interesting biological activities and may play a primary role in the self defence toward herbivores. The presence of a new norlabdane (norlabda‐8(16)‐12‐dien‐14,17‐diol) trivially named as wollemol ( 5 ) was also recognized. Norditerpenes are scarcely distributed in Plant Kingdom and in particular in Gymnosperms and this aspect was discussed. The structure of 5 was determined by extensive NMR analysis employing mono‐ and bidimensional experiments. The 7‐4?‐dimethoxyagathisflavone ( 6 ), a biflavonoid already recognized in Araucariaceae and W. nobilis , was also isolated from male cones together with shikimic acid ( 7 ), a biogenetic precursor of polyphenolic compounds, besides carbohydrates such as glucose ( 8 ) and saccharose ( 9 ), and arginine ( 10 ) a quite common amino acid. 相似文献
104.
Along with sucrose, sorbitol represents the main photosynthetic product and form of translocated carbon in peach. This study aimed at determining whether peach fruit carbohydrate metabolism is affected by changes in source–sink balance , and specifically whether sorbitol or sucrose availability regulates fruit enzyme activities and growth. In various trials, different levels of assimilate availability to growing fruits were induced in vivo by varying crop load of entire trees, leaf : fruit ratio (L:F) of fruiting shoots, or by interrupting the phloem stream (girdling) to individual fruits. In vitro, fruit tissue was incubated in presence/absence of sorbitol and sucrose. Relative growth rate (RGR), enzyme activities and carbohydrates were measured at different fruit growth stages of various peach cultivars in different years. At stage III, high crop load induced higher acid invertase (AI, EC 3.2.1.26) activities and hexose : sucrose ratios. Both sorbitol and sucrose contents were proportional to L:F, while sorbitol dehydrogenase (SDH, EC 1.1.1.14) activity was the only enzyme activity directly related to L:F in both fruit growth stages. Girdling reduced fruit RGR and all major carbohydrates after 4 days and SDH activity already after 48 h, but it did not affect sucrose synthase (SS, EC 2.4.1.13), AI and neutral invertase (NI, EC 3.2.1.27). Fruit incubation in sorbitol for 24 h induced higher SDH activities than in buffer alone. In general, assimilate availability affected both sorbitol and sucrose metabolism in peach fruit, and sorbitol may function as a signal for modulating SDH activity. Under highly competitive conditions, AI activity may be enhanced by assimilate depletion, providing a mechanism to increase fruit sink strength by increasing hexose concentrations. 相似文献
105.
106.
马鹿茸血酶解肽体内免疫功能及抗氧化功能关系的研究 总被引:1,自引:0,他引:1
本文分别选用由木瓜蛋白酶水解天山马鹿茸血获得的肽Ⅰ、肽Ⅱ以及原血为受试样品,研究天山马鹿茸血及其酶解肽对小鼠免疫功能和抗氧化功能的影响,其中肽Ⅰ、肽ⅡDH分别为18.1%、12.2%时,清除OH·能力最强,清除率为50.8%。分别测定了脏器指数,脾细胞增殖实验,血清中溶血素和抗体生成细胞的含量以及小鼠血清总抗氧化能力、SOD活力和MDA含量。结果表明:与对照组相比较,肽Ⅱ组能极显著提高小鼠体液和细胞免疫功能,加强小鼠的抗氧化功能(P〈0.01或P〈0.05)。此外,具有较强抗氧化活性的肽显示出了很强的免疫活性(P〈0.05)。 相似文献
107.
Damiano G. Mita Nadia Diano Valentina Grano Marianna Portaccio Sergio Rossi Umberto Bencivenga Immacolata Manco Carla Nicolucci Mariangela Bianco Tiziana Grimaldi Luigi Mita Svetla Georgieva Tzonka Godjevargova 《Journal of Molecular Catalysis .B, Enzymatic》2009,58(1-4):199-207
Endocrine disruptors are chemicals able to induce adverse effects into wildlife and humans owing to their ability of interfering with the endocrine system. Bisphenol A (BPA) has been chosen as model of endocrine disruptors. To reduce the BPA pollution in waters we proposed the employment of the process of thermodialysis. Two different catalytic membranes have been prepared by covalently immobilizing laccase (from Trametes versicolor) by means of a diazotation process or tyrosinase (from mushroom) by condensation. The support was a nylon membrane. The bioremediation power of both catalytic membranes has been analysed under isothermal and non-isothermal conditions.The advantages in using non-isothermal bioreactors were discussed in terms of reduction of the bioremediation times. 相似文献
108.
JESSICA E. SNODDY MARIAN LANDON GAËLLE BLANVILLAIN AMANDA SOUTHWOOD 《The Journal of wildlife management》2009,73(8):1394-1401
ABSTRACT Mortality due to fisheries interactions has been implicated as a contributor to population decline for several species of sea turtle. The incidental capture of sea turtles in the coastal gillnet fisheries of North Carolina, USA, has received much attention in recent years, and mitigation measures to reduce sea turtle mortality due to gillnet entanglement are a high priority for managers and conservationists. Efforts to evaluate effects of gillnet entanglement on sea turtle populations are complicated by the lack of information on health status of turtles released alive from nets and postrelease mortality. We obtained blood samples from green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) sea turtles captured in gillnets for 20–240 minutes to assess the impacts of gillnet entanglement on blood biochemistry and physiological status. We measured concentrations of lactate, corticosterone, ions (Na+, K+, Cl-, P, Ca2+), enzymes (lactate dehydrogenase [LDH], creatine phosphokinase [CPK], aspartate aminotransferase [AST]), protein, and glucose in the blood and also performed physical examinations of turtles to document external indicators of health status (injuries, lethargy, muted reflexes). We evaluated the effects of entanglement time on blood biochemistry and to look for correlations between blood biochemistry and results of the physical examinations. We observed a significant increase in blood lactate, LDH, CPK, phosphorus, and glucose with increased entanglement time. Alterations in blood biochemistry were generally associated with a decline in health status as indicated by results of the physical examination. Although entanglement time plays an important role in determining the health status of sea turtles upon release from a gillnet, our results suggest that factors such as the depth and severity of entanglement may also have an effect on health status of turtles and the probability of postrelease survival. We were unable to set a maximum unattended gillnet soak time to minimize impacts on captured sea turtles, and therefore recommend that fisheries managers continue to enforce the net attendance regulations currently in place in the lower Cape Fear River, North Carolina, during the summer months. 相似文献
109.
Laura I Klepp Marcelo Soria Federico C Blanco María V Bianco María P Santangelo Angel A Cataldi Fabiana Bigi 《BMC molecular biology》2009,10(1):3
Background
The exported repetitive protein (erp) gene encodes a secreted 36-kDa protein with a central domain containing several proline-glycine-leucine-threonine-serine (PGLTS) repeats. It has been demonstrated that erp is a virulence-associated factor since the disruption of this gene impairs the growth of Mycobacterium bovis and Mycobacterium tuberculosis in mice. 相似文献110.
Raffaele Lombardi Patrizia Circelli Maria Elena Villani Giampaolo Buriani Luca Nardi Valentina Coppola Linda Bianco Eugenio Benvenuto Marcello Donini Carla Marusic 《BMC biotechnology》2009,9(1):96