RESUMO
PURPOSE: To examine the influence of post-exercise protein feeding upon the adaptive response to endurance exercise training. METHODS: In a randomised parallel group design, 25 healthy men and women completed 6 weeks of endurance exercise training by running on a treadmill for 30-60 min at 70-75% maximal oxygen uptake (VO2max) 4 times/week. Participants ingested 1.6 g per kilogram of body mass (g kg BM-1) of carbohydrate (CHO) or an isocaloric carbohydrate-protein solution (CHO-P; 0.8 g carbohydrate kg BM-1 + 0.8 g protein kg BM-1) immediately and 1 h post-exercise. Expired gas, blood and muscle biopsy samples were taken at baseline and follow-up. RESULTS: Exercise training improved VO2max in both groups (p ≤ 0.001), but this increment was not different between groups either in absolute terms or relative to body mass (0.2 ± 0.2 L min-1 and 3.0 ± 2 mL kg-1 min-1, respectively). No change occurred in plasma albumin concentration from baseline to follow-up with CHO-P (4.18 ± 0.18 to 4.23 ± 0.17 g dL-1) or CHO (4.17 ± 0.17 to 4.12 ± 0.22 g dL-1; interaction: p > 0.05). Mechanistic target of rapamycin (mTOR) gene expression was up-regulated in CHO-P (+ 46%; p = 0.025) relative to CHO (+ 4%) following exercise training. CONCLUSION: Post-exercise protein supplementation up-regulated the expression of mTOR in skeletal muscle over 6 weeks of endurance exercise training. However, the magnitude of improvement in VO2max was similar between groups.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Carboidratos da Dieta/farmacologia , Proteínas Alimentares/farmacologia , Treino Aeróbico/métodos , Adolescente , Adulto , Carboidratos da Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Feminino , Humanos , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Consumo de Oxigênio , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
Acanthamoeba is a free-living protozoan genus found in a wide variety of natural habitats, including water, soil, and air. Pathogenic isolates of Acanthamoeba are medically relevant as the causative agent of sight- threatening Acanthamoeba keratitis (AK), serious infections of other organs, and fatal granulomatous amebic encephalitis. Previous work employing DNA sequences of nuclear and mitochondrial small-subunit rRNA genes (SSU rRNA genes) determined the genotypic diversity of Acanthamoeba and found that many named species of Acanthamoeba are associated with particular genotypes. These studies also concluded that nearly all AK infections result from a single molecular genotype: T4. Here, we asked whether Acanthamoeba clinical isolates from non-AK infections are also associated with particular genotypes. DNA sequence determination of nuclear SSU rRNA genes was employed for genotypic identification of 29 isolates of Acanthamoeba from non-AK infections. Sequence analysis demonstrates that T4 is the predominant genotype in non-AK infections, including those in brain, cerebrospinal fluid, nasal passages, skin, and lung. Rare genotypes (T1, T10, and T12) have been isolated from brain infections. We conclude that genotype T4 is the primary genotype in non-AK Acanthamoeba infections, as was the case in AK infections. However, the genotypes that were isolated from brains have not been observed in environmental isolates of Acanthamoeba, and their natural ecological niche is unknown.
Assuntos
Acanthamoeba/classificação , Amebíase/parasitologia , Encefalite/parasitologia , Acanthamoeba/genética , Acanthamoeba/isolamento & purificação , Acanthamoeba/patogenicidade , Ceratite por Acanthamoeba/parasitologia , Animais , DNA de Protozoário/análise , Genótipo , Humanos , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Ribossômico/genética , Análise de Sequência de DNARESUMO
Balamuthia mandrillaris is an opportunistic pathogen that causes granulomatous amebic meningoencephalitis in animals, including humans. Based on sequence analysis of mitochondrial small-subunit-rRNA genes, we developed primers that amplify a Balamuthia-specific PCR product. These primers will be useful for retrospective analyses of fixed tissues and possible identification of Balamuthia in vivo.
Assuntos
DNA Mitocondrial/análise , DNA de Protozoário/análise , Lobosea/isolamento & purificação , RNA Ribossômico 16S/análise , Animais , Lobosea/genética , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genéticaRESUMO
Balamuthia mandrillaris is an opportunistically pathogenic ameba that causes fatal granulomatous amebic encephalitis (GAE) in vertebrates. Previous phylogenetic analyses that included the sequence of a single nuclear small subunit ribosomal RNA gene (18S or ssu rDNA) from this ameba suggested that Balamuthia is closely related to Acanthamoeba, another opportunistically pathogenic amebic genus, which includes multiple ssu rDNA genotypes. We tested whether this also is true for Balamuthia. The nuclear ssu rDNA from 4 isolates and the mitochondrial ssu rDNA from 7 isolates of B. mandrillaris have been sequenced. No variation in the nuclear rDNA sequences and low levels of variation in the mitochondrial rDNA were found. Both gene sequences were consistent with a single genotype for B. mandrillaris. The mitochondrial sequences of B. mandrillaris are unique and should be useful for development of genus-specific diagnostic probes for use with clinical, environmental, and archived specimens.