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111.
Calegario FF Cosso RG Fagian MM Almeida FV Jardim WF Jezek P Arruda P Vercesi AE 《Journal of bioenergetics and biomembranes》2003,35(3):211-220
The CO2 evolution of intact potato tubers (Solanum tuberosum, L., var. Bintje) was analyzed during a 10-day period of their warm (25 ± 2°C) or cold (5 ± 1°C) storage, to evaluate cold-stress effects on expression and activities of plant uncoupling mitochondrial protein (PUMP) and alternative oxidase (AOX). CO2 evolution rates were analyzed at 20°C, to reflect their possible capacities. The 20°C CO2 production declined from 13 to 8 mg kg–1 h–1 after 2 days of warm storage and then (after 3 to 7 days) decreased from 8 to 6.5 mg kg–1 h–1. In contrast, 20°C CO2 evolution did not change after the first day of cold storage, increased up to 14.5 mg kg–1 h–1 after 2 days, and decreased to about 12 mg kg–1 h–1 after 3 to 7 days of cold storage. Cold storage increased PUMP expression as detected by Western blots and led to elevated capacities of both PUMP (44%) and CN-resistant AOX (10 times), but not the cytochrome pathway. Since we found that cold storage led to about the same mitochondrial respiration of 40 nmol O2 min–1 mg–1 attributable to each of the respective proteins, we conclude that both AOX and PUMP equally contribute to adaptation of potato tubers to cold. 相似文献
112.
A. A. Bernardo F. T. Kear O. S. Ruiz J. A. L. Arruda 《The Journal of membrane biology》1994,140(1):31-37
The renal basolateral Na+/HCO
3
–
cotransporter is the main system responsible for HCO
3
–
transport from proximal tubule cells into the blood. The present study was aimed at purifying and functionally reconstituting the Na+/HCO
3
–
cotransporter protein from rabbit renal cortex. Highly purified rabbit renal cortical basolateral membrane vesicles (hereafter designated as original basolateral membrane), enriched 12-fold in Na-K-ATPase, were solubilized in 2% octylglucoside, and then reconstituted in l--phosphatidylcholine (proteoliposomes). Na+/HCO
3
–
cotransporter activity was assessed as the difference in 22Na uptake in the presence of HCO
3
–
and gluconate. The activity of the Na+/HCO
3
–
cotransporter was enhanced 18-fold in the solubilized protein reconstituted into proteoliposomes compared to the original basolateral membranes. The reconstituted solubilized purified protein exhibited kinetic properties similar to the cotransporter from original basolateral membranes. In addition, it was like the original cotransporter, inhibited by disulfonic stilbene SITS, and was eleetrogenic. The catalytic subunit of protein kinase A significantly inhibited Na+/HCO
3
–
cotransporter activity in proteoliposomes. The octylglucoside-solubilized protein was further purified by hydroxylapatite column chromatography, and this resulted in an additional enhancement of Na+/HCO
3
–
cotransporter activity of 80-fold over the original basolateral membranes. The fractions containing the highest activity were further processed by glycerol gradient centrifugation, resulting in a 124- to 300-fold increase in Na+/HCO
3
–
cotransporter activity compared to the original basolateral membranes. SDS-PAGE analysis showed an enhancement of a protein doublet of 56 kD MW in the glycerol gradient fraction. Our results demonstrate that we have partially purified and reconstituted the renal Na+/HCO
3
–
cotransporter and suggest that the 56 kD doublet protein may represent the Na+/HCO
3
–
cotransporter.This work was supported by the Merit Review Program from the Veterans Administration Central Office (J.A.L.A.), and the National Kidney Foundation of Illinois (A.A.B.). 相似文献
113.
Sporotrichosis and histoplasmosis are deep mycosis with a high incidence in human beings in Brazil. In domestic animals histoplasmosis has been described only in dogs, but the occurence of sporotrichosis among domestic animals in Brazil has been described in dogs, cats, mules and asses. There is also a case of this disease reported in a chimpanzee (Pan troglodites). The purpose of this research was to perform an epidomiological study of these mycoses using delayed hypersensitivity tests (histoplasmin and sporotrichin) in Latin American wild mammals. This research was assayed using 96 healthy animals at Parque Zoológico de São Paulo, Brazil: Primates: 33Cebus apella — weeping-capuchin and 16Callithrix jacchus — marmoset; Procyonidae: 37Nasua nasua — coatimundi and 10 Felidae (Panthera onca — jaguar;Felis pardalis — ocelotFelis wiedii — margay;Felis tigrina — wild cat). For intradermic tests, the following antigens were used:Sporothrix schenkii cell suspension (sporotrichin, histoplasmin-filtrate),Histoplasma capsulatum cell suspension (histoplasmin), andHistoplasma capsulatum (polysaccharide). The positivity to histoplasmin was 44.79% (Cebidae 15.15%; Callithricidae 6.25%; Procyonidae 86.49% and Felidae 50.00%, respectively). With respect to sporotrichin, 30.21% (Cebidae 6.06%, Callithricidae 0.0%; Procyonidae 64.86% and Felidae 30.00% respectively). The pattern of infection is similar to that shown by human beings and this may suggest that these animals could be involved in the epidemiologic chain of sporotrichosis and histoplasmosis, the second most prevalent human deep mycoses in Brazil. It is important to point out the absence of similar studies in Latin American wild animals. 相似文献
114.
Jose A. L. Arruda Sandra Sabatini Christof Westenfelder 《The Journal of membrane biology》1982,70(2):135-146
Summary A Na/Ca exchange system has been described in the plasma membrane of several tissues and seems to regulate the concentration of calcium in cytosol. Replacement of extracellular Na by sucrose increases calcium uptake into and decreases calcium efflux from the cell, leading to an increase in cytosolic calcium. The effect of an increase in cytosolic calcium mediated by the Na/Ca exchange system on H+ and Na transport in the turtle and toad bladder was investigated by replacing serosal Na isosmotically by sucrose or choline. Replacement of serosal by sucrose was associated with a significant inhibition of H+ secretion or Na transport which was reversible by addition of NaCl. Replacement of mucosal Na by sucrose failed to alter H+ secretion. Removal of serosal Na was associated with a significant increase in45Ca uptake which could be blocked by pretreatment with lanthanum chloride. Pretreatment with lanthanum chloride blunted the inhibitory effect of replacement of serosal Na by sucrose on H+ and Na transport, thus suggesting that the increase in calcium uptake and the inhibition of transport are causally related. Under anaerobic conditions the rate of H+ or Na transport are linked to the rate of lactate production. The inhibition of Na or H+ transport by removal of serosal Na was accompanied by a proportional decrease in lactate production, thus suggesting that an increase in cytosolic calcium does not inhibit transport by uncoupling glycolysis from transport. Replacement of serosal Na by sucrose did not alter the force of the H+ or Na pump but led to an increase in resistance of the active pathway of H+ and Na transport. The inhibition of Na transport by replacement of serosal Na with sucrose could be reversed by addition of amphotericin B, an agent which increases luminal permeability to Na, thus suggesting that decreased Na entry across the apical membrane is the mechanism responsible for the inhibition of Na transport. The results of the present studies strongly suggest that an increase in cytosolic calcium through the serosal Na/Ca exchange system inhibits H+ and Na transport in the turtle and toad bladder probably by increasing the resistance of the luminal membrane. 相似文献
115.
Alice Sarno Julia Bitencourt Adriano Queiroz Sergio Arruda 《Genetics and molecular biology》2021,44(4)
Despite highly variable efficacy, BCG (Bacillus Calmette-Guérin) is the only vaccine available to prevent the tuberculosis (TB). Genomic heterogeneity between attenuated BCG strains and virulent Mycobacterium tuberculosis might help to explain this vaccine’s impaired capacity to induce long-term protection. Here, we investigate the lipid-related genes absent in attenuated BCG strains in order to correlate changes in both lipid metabolism and cell-wall lipid content to vaccine impairment. Whole genome sequences of M. tuberculosis H37Rv and the six most used BCG strains worldwide were aligned and the absent regions functionally categorized. Genomes of the BCG strains showed a total of 14 non-homologous lipid-related genes, including those belonging to mce3 operon, as well as the gene echaA1, which encodes an enoyl-CoA hydratase, and the genes encoding phospholipases PlcA, PlcB and PlcC. Taken together, the depletion of these M. tuberculosis H37Rv genomic regions were associated with marked alterations in lipid-related genes of BCG strains. Such alterations may indicate a dormant-like state and can be determining factors to the vaccine’s inability to induce long-term protection. These lipids can be further evaluated as an adjuvant to boost the current BCG-based vaccine. 相似文献
116.
Alan de Albuquerque Melo Victor Jos Bastos-Silva Felipe Arruda Moura Rodrigo Rico Bini Adriano Eduardo Lima-Silva Gustavo Gomes de Araujo 《Biology of sport / Institute of Sport》2021,38(4):517
We investigated the effects of caffeine mouth rinse on endurance performance, muscle recruitment (i.e., electromyographic activity of the vastus lateralis and rectus femoris), rating of perceived effort and heart rate. Twelve physically-active healthy men cycled at 80% of their respiratory compensation point until task failure. The participants rinsed their mouths for 10 seconds with placebo (PLA, 25 mL of a solution composed of non-caloric mint essence) or caffeine (CAF, 25 mL of 1.2% of anhydrous caffeine concentration with non-caloric mint essence) every 15 minutes of exercise. Time until exhaustion increased 17% (effect size = 0.70) in CAF compared to PLA (p = 0.04). The wavebands of low-frequency electromyographic activity (EMG) of the vastus lateralis and rectus femoris was lower in CAF group than PLA at 50% of the time until exhaustion (p = 0.04). The global EMG signal was lower in CAF group than PLA at 100% of the time until exhaustion (p = 0.001). The rating of perceived effort pooled was higher in CAF mouth rinse (p = 0.001) than PLA group. No effect was found on the heart rate between the groups (p > 0.05). Caffeine mouth rinse increases endurance performance, rating of perceived effort and decreases muscle activity during a moderate-intensity exercise. 相似文献
117.
Priscila Farias Tempaku Juliana Ramirez Arruda Diego Robles Mazzotti Bruno S. B. Gonçalves Mário Pedrazzoli Lia Bittencourt 《Chronobiology international》2017,34(4):504-510
The circadian system coordinates internal events in a daily schedule to make sure that the body systems are synchronized to environmental time and internal cues. One important behavioral aspect of the circadian system is the chronotype. It is usually assessed through subjective questionnaires, being the Horne-Ostberg Morningness–Eveningness Questionnaire (MEQ) one of the most used. It classifies individuals into three major categories: morning, evening, and intermediate types. Recently, it has been hypothesized the existence of a fourth chronotype, the bimodal type, through an algorithm derived from the MEQ responses. Bimodals answer as morning-types in some questions, and as evening-types in others, resulting in an intermediate total score. To better characterize this phenotype, the present study aimed to detect and characterize the frequency of the bimodal chronotype in the EPISONO, a large population-based cohort, as well as to verify the association between bimodality and sleep parameters and genetic variation in the PER3 gene. Of the 1,042 individuals who participated of the EPISONO, 857 had MEQ filled correctly. We found that 16% of our sample were bimodal types. We observed that bimodal individuals were significantly younger and had lower body mass index. The association between PER3 VNTR genotype and gender with bimodal chronotype was not significant. However, we found an association between bimodality and Epworth Sleepiness Scale (EES) and apnea-hypopnea index (AHI). We did not find a statistically significant difference between bimodals and intermediate non-bimodals for the studied variables. Lastly, it was observed that the most significant predictors for bimodal chronotype were female gender, AHI, and EES. In conclusion, the present work provides more evidence that the bimodal type might have to be considered when classifying chronotype and its association with young age and sleepiness may be due to the influence of social and environmental factors. 相似文献
118.
A. Moreira R.F.P. Bacurau M.H. Napimoga A.F.S. Arruda C.G. Freitas G. Drago M.S. Aoki 《Biology of sport / Institute of Sport》2013,30(4):243-247
Athletes engaged in strenuous training might experience transient immune suppression that could lead to greater incidence of upper respiratory tract infections (URTI). Since interleukin 21 (IL-21) stimulates immunoglobulin A (IgA) secreting cells and a low level of this immunoglobulin is associated with increased incidence of URTI, the aim of the present study was to investigate the effect of a basketball match on salivary cortisol (sC), salivary IL-21 (sIL-21) and salivary IgA (sIgA) levels. Twenty male basketball players participated in an official game in two teams (10 players in each team). The saliva samples were collected before the warm-up and approximately 10-15 min after the end of the match and were analysed by ELISA methods. sC concentration increased significantly after the match while sIL-21 level was reduced (p < 0.05). In opposition to the study''s hypothesis, sIgA level did not change in response to the match. The present findings suggest that a basketball match is sufficiently stressful to elevate sC concentration and attenuates the sIL-21 output without compromising the sIgA level. It is reasonable to speculate that the stability of sIgA acute responses to the match, despite the decrement in sIL-21, indicates that other mechanisms rather than IL-21 stimulating B cell proliferation/differentiation might modulate IgA concentration and secretion rate. 相似文献
119.
Finite element modeling of human skin using an isotropic, nonlinear elastic constitutive model 总被引:8,自引:0,他引:8
The collagen network in skin is largely responsible for the nonlinear mechanical stress-strain response of skin. We hypothesize that the force-stretch response of collagen is governed by the entropics of long-chain molecules. We show that a constitutive model derived from the statistical mechanics of long-chain molecules, corresponding to the fibrous collagen network in skin, captures the mechanical response of skin. A connection between the physiologically meaningful parameters of network molecular chain density and free length of collagen fibers and the constitutively significant parameters of initial modulus and limiting stretch is thus established. The relevant constitutive law is shown to have predictive capabilities related to skin histology by replicating in vivo and in vitro experimental results. From finite element simulations, this modeling approach predicts that the collagen network in hypertrophic scars is more dense and the constituent collagen fibers have shorter free lengths than in healthy skin. Additionally, the model is shown to predict that as rat skin ages, collagen network density increases and fiber free length decreases. The importance of knowledge of the in situ stress state for analyzing skin response and validating constitutive laws is also demonstrated. 相似文献
120.