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1.
Mar Drugs ; 21(9)2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37755084

RESUMO

In the present study, the recovery of valuable molecules of proven anti-inflammatory and antimicrobial activity of the acidophilic microalga Coccomyxa onubensis (C. onubensis) were evaluated using green technologies based on ultrasound-assisted extraction (UAE). Using a factorial design (3 × 2) based on response surface methodology and Pareto charts, two types of ultrasonic equipment (bath and probe) were evaluated to recover valuable compounds, including the major terpenoid of C. onubensis, lutein, and the antimicrobial activity of the microalgal extracts obtained under optimal ultrasound conditions (desirability function) was evaluated versus conventional extraction. Significant differences in lutein recovery were observed between ultrasonic bath and ultrasonic probe and conventional extraction. Furthermore, the antimicrobial activity displayed by C. onubensis UAE-based extracts was greater than that obtained in solvent-based extracts, highlighting the effects of the extracts against pathogens such as Enterococcus hirae and Bacillus subtilis, followed by Staphylococcus aureus and Escherichia coli. In addition, gas chromatography-mass spectrometry was performed to detect valuable anti-inflammatory and antimicrobial biomolecules present in the optimal C. onubensis extracts, which revealed that phytol, sterol-like, terpenoid, and even fatty acid structures could also be responsible for the antibacterial activities of the extracts. Moreover, UAE displayed a positive effect on the recovery of valuable molecules, improving biocidal effects. Our study results facilitate the use of green technology as a good tool in algal bioprocess engineering, improving energy consumption and minimizing environmental impacts and process costs, as well as provide a valuable product for applications in the field of biotechnology.


Assuntos
Anti-Infecciosos , Clorófitas , Microalgas , Luteína , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Extratos Vegetais/farmacologia
2.
Environ Geochem Health ; 45(1): 151-170, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34677729

RESUMO

Mining affects the environment, particularly through the persistence of accumulation of tailings materials; this is aggravated under tropical climatic conditions, which favours the release of potentially toxic elements (PTEs) bioavailable to the local flora and fauna and supposing a risk to human health. The Remance gold mine (Panamá), exploited intermittently for more than 100 years, and has remained derelict for over 20 years. Within the area live farmers who carry out subsistence agriculture and livestock activities. The objective of this study has been to study the transference of PTEs in the local agricultural soil-plants system, with the goal of identifying their bioavailability to perform a human risk assessment. The results obtained of the Bioaccumulation coefficient in local plants show very weak to strong absorption of As (< 0.001-1.50), Hg (< 0.001-2.38), Sb (0.01-7.83), Cu (0.02-2.89), and Zn (0.06-5.32). In the case of Cu in grass (18.3 mg kg-1) and plants (16.9 mg kg-1) the concentrations exceed the maximum authorised value in animal nutrition for ruminants (10 mg kg-1). The risk to human health for edible plants exceeds the non-carcinogenic risk for rice, corn, cassava, and tea leaves for Sb (HQ 19.450, 18.304, 6.075, 1.830, respectively), the carcinogenic risk for Cu (CR = 2.3 × 10-3, 7.7 × 10 -4, 1.1 × 10-3, 1.0 × 10-3, respectively), and the carcinogenic risk for As in rice, corn and tea leaves (CR = 8 × 10-5, 3 × 10-5, 3 × 10-5, respectively). Urgent measures are needed to alleviate these effects.


Assuntos
Metais Pesados , Poluentes do Solo , Humanos , Metais Pesados/análise , Disponibilidade Biológica , Monitoramento Ambiental/métodos , Plantas , Solo , Medição de Risco/métodos , Chá , Poluentes do Solo/toxicidade , Poluentes do Solo/análise
3.
Clin Exp Rheumatol ; 39(1): 105-114, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33124565

RESUMO

OBJECTIVES: Clinicians often face the challenge of providing effective and safe therapy for pregnant women with uveitis. Certolizumab pegol (CZP) differs from other anti-TNFα agents due to its limited placental transfer. In this study we assessed the efficacy of CZP in pregnant women with uveitis. We also provided information on outcomes of pregnant women and neonates exposed to CZP. METHODS: We carried out a multicentre study of women with uveitis who received CZP during pregnancy and their neonates. The main visual outcomes were visual acuity (VA), intraocular inflammation and corticosteroid-sparing effect. Pregnancy outcomes, maternal and neonatal infections and congenital malformations were also assessed. RESULTS: We studied 14 women (23 affected eyes); mean age of 34.3±5.5 years. The underlying diseases were spondyloarthritis (n=7), idiopathic (n=2), and Vogt-Koyanagi-Harada, rheumatoid arthritis, juvenile idiopathic arthritis, punctate inner choroidopathy and Behçet's disease (1 each). The patterns of ocular involvement were anterior (n=10), posterior (n=2), intermediate (n=1), panuveitis (n=1). Cystoid macular oedema was present in one patient (1 eye). Uveitis was bilateral in nine cases and chronic in seven patients. CZP was started before getting pregnant in ten patients and after conceiving in four. All patients achieved or maintained ocular remission throughout pregnancy. Fifteen healthy infants were born. Only one woman presented a mild infection during pregnancy. Neither infections nor malformations were observed in neonates after a follow-up of 6 months. Six infants were breastfed and all of them received scheduled vaccinations without complications. CONCLUSIONS: Certolizumab pegol is effective and safe in women with uveitis during pregnancy.


Assuntos
Gestantes , Uveíte , Adulto , Terapia Biológica , Certolizumab Pegol/efeitos adversos , Feminino , Humanos , Imunossupressores/efeitos adversos , Lactente , Recém-Nascido , Gravidez , Resultado do Tratamento , Uveíte/diagnóstico , Uveíte/tratamento farmacológico
4.
J Sci Food Agric ; 98(14): 5534-5540, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29691879

RESUMO

BACKGROUND: In the last decade, diseases of bacterial origin in onions have increased and this has led to significant losses in production. These diseases are currently observed in both the Old and New Worlds. The present study aimed to evaluate whether the irrigation method influences the incidence of diseases of bacterial origin. RESULTS: In cases where the inoculum was natural, the initial incidence of soft bacterial rot did not manifest in any treatment in the first year, whereas, at the end of the conservation period, all treatments had increased incidences of infection. Sprinkler irrigation (8%) was statistically differentiated from the other treatments, for which the final incidence was similar (4.5%). For all irrigation treatments, the final incidence of bacterial soft rot decreased or remained stable towards the end of the cycle, with the exception of sprinkler irrigation in 2015, which increased. CONCLUSION: From the results of the present study, it can be inferred that the irrigation method does have an influence on the incidence of diseases of bacterial origin in the post-harvest stage for onions. © 2018 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Água Doce/microbiologia , Cebolas/microbiologia , Doenças das Plantas/microbiologia , Cebolas/crescimento & desenvolvimento
5.
Rev. senol. patol. mamar. (Ed. impr.) ; 28(4): 148-153, oct.-dic. 2015. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-142021

RESUMO

Objetivo. El hallazgo en una biopsia de mama de lesiones proliferativas atípicas, implica la necesidad de cirugía y extirpación de dicha lesión. El objetivo del estudio fue determinar la tasa de escisiones completas mediante el uso del dispositivo IntactR-BLES de lesiones categorizadas B3 en biopsia asistida por vacío (BAV). Pacientes y métodos. Realizamos un estudio descriptivo observacional de la utilidad de este sistema que consigue, con anestesia local y ambulatoriamente, la obtención percutánea de una muestra de tejido de 20 × 20 mm, permitiendo la valoración de los márgenes de resección, llevado a cabo entre febrero de 2012 y septiembre de 2014. Resultados. Se analizaron 25 procedimientos. La biopsia inicial demostraba principalmente la presencia de atipia epitelial plana (56%) e hiperplasia ductal atípica (32%). El tamaño medio de la pieza extirpada fue de 20 × 10 × 8 mm, en un espécimen único, permitiendo la valoración de márgenes en todas ellas (100%). En el estudio anatomopatológico definitivo no se encontró lesión residual en el 68% de los casos, así como 2 casos (8%) de carcinoma intraductal (CDIS), infradiagnosticados con la biopsia inicial. El estudio de márgenes demostró estar libres en el 85% de los casos. No ha habido ningún efecto adverso importante, solo un caso de hematoma y un caso de dolor superior al normal. Conclusiones. El sistema de escisión percutánea (Intact®-BLES) permite mediante un procedimiento con anestesia local, de forma ambulatoria y sin complicaciones importantes evitar la cirugía en un 88% de los casos de lesiones premalignas en la biopsia inicial. Así mismo, permite demostrar la presencia de CDIS en un 8% de los casos (infradiagnosticados) (AU)


Objective. The finding of an atypical proliferative lesion in a breast biopsy implies the need for surgical removal of the lesion. The aim of this study was to determine the complete excision rate with the IntactR-BLES device of B3 lesions diagnosed in vacuum-assisted biopsy. Patients and methods. A descriptive study was carried out to appraise the usefulness of this system, which obtains a percutaneous 20×20 mm tissue sample under local anaesthesia and on an outpatient basis, allowing assessment of the resection margins performed between February 2012 and September 2014. Results. We analysed 25 procedures. The initial biopsy showed mostly the presence of flat epithelial atypia (56%) and atypical ductal hyperplasia (32%). The mean size of the resected specimen was 20×10×8 mm, in a single specimen, allowing assessment of margins in all of them (100%). The definitive pathological analysis reported no residual lesion in 68% of the patients and intraductal carcinoma in situ (DCIS) in 2 patients (8%), which had been underdiagnosed with the initial biopsy. Study of margins also demonstrated free margins in 85% of the patients. There were no major adverse effects, and only 1 case of haematoma and 1 case of higher-than-normal pain. Conclusions. The percutaneous excision system (Intact®-BLES) can be performed under local anaesthesia on an outpatient basis without major complications, thus avoiding surgery in 88% of cases of premalignant lesions in the initial biopsy. In addition, this procedure revealed the presence of DCIS in 8% of the patients (underdiagnosed) (AU)


Assuntos
Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Mamárias/epidemiologia , Doenças Mamárias/cirurgia , Procedimentos Cirúrgicos Ambulatórios/métodos , Procedimentos Cirúrgicos Ambulatórios , Hiperplasia/cirurgia , Programas de Rastreamento/métodos , Biópsia com Agulha de Grande Calibre/instrumentação , Biópsia com Agulha de Grande Calibre/métodos , Biópsia com Agulha de Grande Calibre , Anestesia Local/métodos , Anestesia Local , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma Intraductal não Infiltrante
6.
Mol Nutr Food Res ; 58(9): 1897-906, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24995559

RESUMO

SCOPE: Dietary fat influences systemic inflammatory status, which determines the progression of age-associated diseases. Since somatostatin (SST), cortistatin (CORT), and ghrelin systems modulate inflammatory response, we aim to comprehensively characterize the presence and regulation of the components of these systems in the peripheral blood mononuclear cells (PMBCs), a subset of white blood cells placed at the crossroad between diet and inflammation, in response to diets with different fat composition, and during the postprandial phase in elderly subjects. METHODS AND RESULTS: The applied nutrigenomic, inflammation-related PBMC-based approach revealed that the majority of components of SST/CORT and ghrelin systems are present in the human PBMCs. Particularly, CORT, SST/CORT receptors (sst2, sst3, sst5, and sst5TMD4), ghrelin, its acylating enzyme (GOAT), In1-ghrelin variant, and GHSR1b were detected in PBMCs. Their expression was altered in the long-term by diet composition, and in the short-term, during the postprandial phase. Of particular relevance is the postprandial elevation of CORT, sst2, and sst5 expression in PBMCs of subjects under n-3 PUFAs-enriched diet. CONCLUSION: Our results suggest a potential relevant role of CORT/ssts and ghrelin systems in regulating PBMCs response to nutrient intake, which could help to explain the positive effects of n-3 PUFAs-enriched diets in reducing the inflammatory response.


Assuntos
Gorduras na Dieta/farmacologia , Grelina/sangue , Leucócitos Mononucleares/efeitos dos fármacos , Neuropeptídeos/sangue , Período Pós-Prandial/efeitos dos fármacos , Idoso , Dieta Mediterrânea , Dieta Ocidental , Ácidos Graxos Ômega-3/farmacologia , Feminino , Grelina/metabolismo , Humanos , Inflamação/metabolismo , Inflamação/prevenção & controle , Leucócitos Mononucleares/fisiologia , Masculino , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Nutrigenômica/métodos , Receptores de Somatostatina/genética , Somatostatina/genética
7.
Reumatol. clín. (Barc.) ; 10(2): 94-100, mar.-abr. 2014. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-119833

RESUMO

Objetivos: Analizar la experiencia española en un estudio internacional para evaluar tocilizumab en pacientes con artritis reumatoide (AR) con respuesta insuficiente al tratamiento con fármacos antirreumáticos modificadores de la enfermedad convencionales (FAME) o anti-TNF en condiciones cercanas a la práctica clínica habitual. Material y métodos: Subanálisis de 170 pacientes con AR que participaron en España en un ensayo clínico, internacional abierto de fase iiib, que presentaban una respuesta inadecuada al tratamiento con FAME o anti-TNF. Los pacientes recibieron 8 mg/kg de tocilizumab cada 4 semanas en combinación con FAME o en monoterapia durante un periodo de 20 semanas. Se evaluaron la seguridad y la eficacia de tocilizumab distinguiendo entre pacientes con fallo a FAME o anti-TNF y, dentro de estos, entre los que habían hecho o no periodo de lavado del anti-TNF. Resultados: Los acontecimientos adversos más frecuentes fueron infecciones (25%) y elevación de colesterol total (38%) y transaminasas (15%). Cinco pacientes abandonaron el estudio por un acontecimiento adverso. El 71/50/30% de los pacientes cumplía criterios de respuesta ACR 20/50/70 a los 6 meses del inicio del tratamiento con tocilizumab. Los pacientes naïve para anti-TNF presentaron una mayor respuesta ACR20: el 76% frente a un 64% en el grupo anti-TNF con lavado previo y el 66% en el grupo anti-TNF sin lavado previo. Conclusiones: Se confirma el perfil de seguridad de tocilizumab en pacientes con AR y fallo a FAME o anti-TNF. Tocilizumab es más eficaz en pacientes que no responden de forma satisfactoria al tratamiento con FAME convencionales que con anti-TNF (AU)


Objectives: To analyze the Spanish experience in an international study which evaluated tocilizumab in patients with rheumatoid arthritis (RA) and an inadequate response to conventional disease-modifying antirheumatic drugs (DMARDs) or tumor necrosis factor inhibitors (TNFis) in a clinical practice setting. Material and methods: Subanalysis of 170 patients with RA from Spain who participated in a phase IIIb, open-label, international clinical trial. Patients presented inadequate response to DMARDs or TNFis. They received 8 mg/kg of tocilizumab every 4 weeks in combination with a DMARD or as monotherapy during 20 weeks. Safety and efficacy of tocilizumab were analyzed. Special emphasis was placed on differences between failure to a DMARD or to a TNFi and the need to switch to tocilizumab with or without a washout period in patients who had previously received TNFi. Results: The most common adverse events were infections (25%), increased total cholesterol (38%) and transaminases (15%). Five patients discontinued the study due to an adverse event. After six months of tocilizumab treatment, 71/50/30% of patients had ACR 20/50/70 responses, respectively. A higher proportion of TNFi-naive patients presented an ACR20 response: 76% compared to 64% in the TNFi group with previous washout and 66% in the TNFi group without previous washout. Conclusions: Safety results were consistent with previous results in patients with RA and an inadequate response to DMARDs or TNFis. Tocilizumab is more effective in patients who did not respond to conventional DMARDs than in patients who did not respond to TNFis (AU)


Assuntos
Humanos , Artrite Reumatoide/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , Terapia Biológica , Antirreumáticos/uso terapêutico , Fatores de Necrose Tumoral/antagonistas & inibidores
8.
Cell Biochem Funct ; 28(4): 266-73, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20517889

RESUMO

Active lymphocytes (LY) and macrophages (MPhi) are involved in the pathophysiology of rheumatoid arthritis (RA). Due to its anti-inflammatory effect, physical exercise may be beneficial in RA by acting on the immune system (IS). Thus, female Wistar rats with type II collagen-induced arthritis (CIA) were submitted to swimming training (6 weeks, 5 days/week, 60 min/day) and some biochemical and immune parameters, such as the metabolism of glucose and glutamine and function of LY and MPhi, were evaluated. In addition, plasma levels of some hormones and of interleukin-2 (IL-2) were also determined. Results demonstrate that CIA increased lymphocyte proliferation (1.9- and 1.7-fold, respectively, in response to concanavalin A (ConA) and lipopolysaccharide (LPS)), as well as macrophage H(2)O(2) production (1.6-fold), in comparison to control. Exercise training prevented the activation of immune cells, induced by CIA, and established a pattern of substrate utilization similar to that described as normal for these cells. Exercise also promoted an elevation of plasma levels of corticosterone (22.2%), progesterone (1.7-fold) and IL-2 (2.6-fold). Our data suggest that chronic exercise is able to counterbalance the effects of CIA on cells of the IS, reinforcing the proposal that the benefits of exercise may not be restricted to aerobic capacity and/or strength improvement.


Assuntos
Artrite Experimental/metabolismo , Linfócitos/metabolismo , Macrófagos/metabolismo , Condicionamento Físico Animal , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/prevenção & controle , Bovinos , Colágeno Tipo II/toxicidade , Corticosterona/sangue , Feminino , Glucose/metabolismo , Glutamina/metabolismo , Interleucina-2/sangue , Linfócitos/imunologia , Linfócitos/fisiologia , Macrófagos/imunologia , Macrófagos/fisiologia , Progesterona/sangue , Ratos , Ratos Wistar
9.
Rev. derecho genoma hum ; (25): 15-17, jul.-dic. 2006.
Artigo em Es | IBECS | ID: ibc-71999

RESUMO

Este artículo está basado en el proyecto de Ley de Investigación Biomédica y analiza sus novedades, tales como: la creación del Comité de Bioética de España, la nueva regulación de la transferencia nuclear, los biobancos, y finalmente analiza como se asientan las bases para el fomento de la carrera profesional del investigador en el Sistema Nacional de Salud. Este borrador de ley supone una gran oportunidad para la comunidad científica


This article looks at the draft bill of the la won Biomedical Research. It analyses its novelties, such as: the creation of a Spanish Bioethics Committee, the new regulation on nuclear transfer, biobanks and finally the setting of the groundwork for the fostering of the professional degree of researcher in the National health System. This draft bill is agreat opportunity for the scientific community


Assuntos
Humanos , Bioética , Pesquisa Biomédica/legislação & jurisprudência , Bancos de Espécimes Biológicos , Programas Nacionais de Saúde , Espanha , Doadores de Tecidos
10.
Rev Derecho Genoma Hum ; (25): 15-7, 2006.
Artigo em Espanhol | MEDLINE | ID: mdl-17393794

RESUMO

This article looks at the draft bill of the law on Biomedical Research. It analyses its novelties, such as: the creation of a Spanish Bioethics Committee, the new regulation on nuclear transfer, biobanks and finally the setting of the groundwork for the fostering of the professional degree of researcher in the National Health System. This draft bill is a great opportunity for the scientific community.


Assuntos
Bioética , Pesquisa Biomédica/legislação & jurisprudência , Bancos de Espécimes Biológicos , Humanos , Programas Nacionais de Saúde , Técnicas de Transferência Nuclear , Espanha , Doadores de Tecidos
11.
Virology ; 333(2): 374-86, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15721369

RESUMO

The HIV-1 viral accessory protein Vif prevents the encapsidation of the antiviral cellular cytidine deaminases APOBEC3F and APOBEC3G by inducing their proteasomal degradation. In the absence of Vif, APOBEC3G is encapsidated and blocks virus replication by deaminating cytosines of the viral cDNA. APOBEC3G encapsidation has been recently shown to depend on the viral nucleocapsid protein; however, the role of RNA remains unclear. Using APOBEC3G deletion and point mutants, we mapped the encapsidation determinant to the Zn(2+) coordination residues of the N-terminal catalytic domain (CD1). Notably, these residues were also required for RNA binding. Mutations in the two aromatic residues of CD1 but not CD2, which are conserved in cytidine deaminase core domains and are required for RNA binding, prevented encapsidation into HIV-1, HTLV-I and MLV. The Zn(2+) coordination residues of the C-terminal catalytic domain (CD2) were not required for encapsidation but were essential for cytidine deaminase activity and the antiviral effect. These findings suggest a model in which CD1 mediates encapsidation and RNA binding while CD2 mediates cytidine deaminase activity. Interestingly, HTLV-I was relatively resistant to the antiviral effects of encapsidated APOBEC3G.


Assuntos
HIV-1/fisiologia , Proteínas/química , Proteínas/fisiologia , Desaminase APOBEC-3G , Animais , Sequência de Bases , Domínio Catalítico , Citidina Desaminase , DNA/genética , Deleção de Genes , Produtos do Gene vif/fisiologia , Genes Virais , Genes vif , Teste de Complementação Genética , Infecções por HIV/enzimologia , Infecções por HIV/virologia , HIV-1/genética , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Humanos , Vírus da Leucemia Murina/genética , Vírus da Leucemia Murina/fisiologia , Camundongos , Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/fisiologia , Nucleosídeo Desaminases , Estrutura Terciária de Proteína , Proteínas Repressoras , Montagem de Vírus , Replicação Viral/genética , Replicação Viral/fisiologia , Zinco/química , Produtos do Gene vif do Vírus da Imunodeficiência Humana
12.
Ann Nutr Metab ; 48(2): 90-4, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14988638

RESUMO

BACKGROUND/AIMS: Carnitine is a co-factor of the enzymatic system involved in long chain fatty acid transport across the mitochondrial membrane. This physiological role of carnitine raised the hypothesis that this compound could act as a 'fat burner' by optimizing fat oxidation and consequently reducing its availability for storage. Our aim was to verify whether carnitine supplementation could maximize fat mass loss in trained rats. METHODS: Male Wistar rats (200 g) were divided into four groups: control (C), sedentary supplemented (S), trained (T) and trained supplemented (TS). The training protocol consisted of bouts of swimming exercise (60 min x day(-1)) for 6 weeks. During the last 14 days, before sacrifice, the supplemented groups received a daily dose of 28 mg x kg(-1) of L-carnitine. Carcass fat content, weight and fat content of adipose tissues were evaluated in all experimental groups. RESULTS: Our results indicate that carnitine feeding, per se, failed to promote fat mass loss. Endurance training successfully induced a decrease in the fat content in the carcass (28%) and the weight of adipose tissues (retroperitoneal and mesenteric depots by 41 and 20%, respectively) in comparison to C. Despite the augmented carnitine content in the soleus mitochondria (2-fold) observed in TS, the higher content did not maximize the fat loss induced by endurance training. CONCLUSIONS: Our data strongly suggest that endurance training, rather than carnitine content, is the major factor involved in fat mass loss.


Assuntos
Tecido Adiposo/metabolismo , Carnitina/farmacologia , Resistência Física/fisiologia , Redução de Peso/efeitos dos fármacos , Animais , Carnitina/metabolismo , Suplementos Nutricionais , Masculino , Condicionamento Físico Animal/fisiologia , Distribuição Aleatória , Ratos , Ratos Wistar
13.
Rev. bras. med. esporte ; 9(5): 282-287, set.-out. 2003. tab
Artigo em Português | LILACS | ID: lil-354296

RESUMO

Estudos disponíveis na literatura demonstram que a realizaçäo prévia de um exercício de endurance afeta de modo adverso o desempenho no exercício de força subseqüente. Tal ocorrência pode estar relacionada a mudanças metabólicas induzidas pelo exercício de endurance. O objetivo deste trabalho foi verificar se a ingestäo de carboidrato (CHO) pode atenuar os efeitos de uma sessäo aguda de exercício de endurance sobre o desempenho de força. A fim de testar essa hipótese, seis estudantes universitárias (164 ± 5,9cm; 64,9 ± 7,2kg), com experiência em treinamento de força, foram submetidas a um teste para a determinaçäo do VO2pico (44 ± 4,3ml.min-1) e um teste de 1-RM para o leg press (186 ± 22,5kg) seguido de um teste de repetições máximas (duas séries de leg press realizado a 70 por cento de 1-RM até exaustäo 1ª série 21 ± 2,6 e 2ª série 11 ± 1,9 repetições) em dias diferentes. Seguindo um protocolo duplo-cego, os sujeitos foram submetidos a duas condições experimentais, recebendo uma bebida placebo (P) ou outra contendo carboidrato (6 por cento - maltodextrina), antes (500ml) e durante (500ml) a realizaçäo de uma sessäo de exercício de endurance (corrida em esteira 70 por cento do VO2pico por 45 minutos). Em seguida ao exercício de endurance, os indivíduos realizaram um teste de 1-RM seguido pelo teste de repetições máximas. Näo foram observadas mudanças no teste de 1-RM e na concentraçäo plasmática de glicose entre as condições experimentais (P x CHO). O número de repetições máximas a 70 por cento-1RM apresentou decréscimo nas duas situações (P 1ª série 13 ± 2,9 repetições e 2ª série 6 ± 2,1 repetições; CHO 1ª série 15 ± 2,5 repetições e 2ª série 7 ± 1,7 repetições, p < 0,05), näo havendo diferença entre ambas. Uma sessäo de exercício de endurance (intensidade moderada e longa duraçäo) realizada previamente afeta de modo negativo a capacidade de realizar repetições máximas. Independente do mecanismo envolvido na reduçäo do número de repetições máximas, o consumo de carboidrato foi incapaz de reverter esse efeito prejudicial


Assuntos
Humanos , Aptidão Física/fisiologia , Carboidratos da Dieta , Suplementos Nutricionais , Exercício Físico/fisiologia , Teste de Esforço , Educação Física e Treinamento , Resistência Física/fisiologia
14.
Am J Physiol Endocrinol Metab ; 285(5): E1039-46, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12876074

RESUMO

Previously, it has been shown that background color conditions regulate the overall activity of the frog intermediate lobe by varying the proportions of the two subtypes of melanotropes existing in the gland, the highly active or secretory melanotropes and hormone storage melanotropes, depending on melanocyte-stimulating hormone requirements. However, the factors and mechanisms underlying these background-induced changes are still unknown. In the present study, we investigated whether hypothalamic factors known to regulate melanotrope cell function can induce changes in vitro similar to those caused by background adaptation in vivo. We found that the inhibitors apomorphine (a dopamine receptor agonist) and neuropeptide Y decreased the number of active melanotropes and increased simultaneously that of storage melanotropes. On the other hand, the stimulator TRH increased the number of active cells and concomitantly reduced that of storage cells. Inasmuch as none of these treatments modified the apoptotic and proliferation rates in melanotrope cells, it appears that these hypothalamic factors caused actual interconversions of cells from a subpopulation to its counterpart. Taken together, these findings suggest that the hypothalamus would control melanotrope activity not only through short-term regulation of hormone synthesis and release, but also through a long-term regulation of the secretory phenotype of these cells whereby the activity of the intermediate lobe would be adjusted to fulfill the hormonal requirements imposed by background conditions.


Assuntos
Hipotálamo/fisiologia , Hipófise/metabolismo , alfa-MSH/metabolismo , Adaptação Fisiológica , Animais , Apomorfina/farmacologia , Apoptose , Divisão Celular , Células Cultivadas , Masculino , Neuropeptídeo Y/farmacologia , Hipófise/citologia , Hipófise/efeitos dos fármacos , Rana ridibunda , Pigmentação da Pele/fisiologia , Hormônio Liberador de Tireotropina/farmacologia
15.
Nutrition ; 19(4): 337-41, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12679168

RESUMO

OBJECTIVE: We investigated the effect of L-carnitine supplementation on carnitine content in muscle fiber, glucose, and fatty acid metabolism and on performance in trained rats. METHODS: Male Wistar rats received a daily dose of 28 mg/kg, intragastrically, during the last 4 wk of a 6-wk moderate-intensity training program. The contents of carnitine and coenzyme A were evaluated in muscle fiber and its capacity to metabolize labeled glucose, oleate, and pyruvate. The ergogenic effect of the amine was assessed by the evaluation of time until exhaustion in an exercise session. The results were analyzed by analysis of variance and Tukey's post hoc test, and significance was set at P < 0.05. RESULTS: In our model, carnitine supplementation increased time until exhaustion (14.0%), similar to that observed for trained rats, but the effect was even greater (30.3% increase) in the supplemented and trained rats. Carnitine supplementation increased oleate decarboxylation (17% for sedentary rats and 119% for trained rats) and decreased glucose (29.7% and 45% for sedentary and trained rats, respectively) and [2-(14)C ]-pyruvate (45.9% and 61% for sedentary and trained rats, respectively) decarboxylation. The flux of [1-(14)C]-pyruvate through the Krebs cycle increased by 32% and 70% for supplemented sedentary and trained rats, respectively. The training protocol also increased [1-(14)C]-pyruvate decarboxylation by 32%. The cytosolic content of free, long-chain, and short-chain acyl-carnitine increased in the soleus muscle obtained from supplemented sedentary rats by 28%, 117%, and 16%, respectively, and 99%, 205%, and 32% for the muscle from supplemented trained rats. CONCLUSIONS: This study showed that carnitine supplementation increases fatty acid oxidation in skeletal muscle by a mechanism that includes increasing total carnitine content in soleus muscle mitochondria and the total content of acyl-carnitine. The most interesting finding was that the effect of supplementation was even greater in trained rats that had received 3-wk supplementation of carnitine.


Assuntos
Carnitina/metabolismo , Ácidos Graxos/metabolismo , Glucose/metabolismo , Músculos/metabolismo , Condicionamento Físico Animal/fisiologia , Esforço Físico/fisiologia , Animais , Carnitina/administração & dosagem , Ciclo do Ácido Cítrico/efeitos dos fármacos , Coenzima A/análise , Suplementos Nutricionais , Masculino , Músculos/enzimologia , Ácido Oleico/metabolismo , Esforço Físico/efeitos dos fármacos , Ácido Pirúvico/metabolismo , Ratos , Ratos Wistar , Fatores de Tempo
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