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1.
Nat Aging ; 3(2): 162-172, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-37118113

RESUMO

Diminished insulin and insulin-like growth factor-1 signaling extends the lifespan of invertebrates1-4; however, whether it is a feasible longevity target in mammals is less clear5-12. Clinically utilized therapeutics that target this pathway, such as small-molecule inhibitors of phosphoinositide 3-kinase p110α (PI3Ki), provide a translatable approach to studying the impact of these pathways on aging. Here, we provide evidence that dietary supplementation with the PI3Ki alpelisib from middle age extends the median and maximal lifespan of mice, an effect that was more pronounced in females. While long-term PI3Ki treatment was well tolerated and led to greater strength and balance, negative impacts on common human aging markers, including reductions in bone mass and mild hyperglycemia, were also evident. These results suggest that while pharmacological suppression of insulin receptor (IR)/insulin-like growth factor receptor (IGFR) targets could represent a promising approach to delaying some aspects of aging, caution should be taken in translation to humans.


Assuntos
Longevidade , Fosfatidilinositol 3-Quinases , Camundongos , Animais , Masculino , Humanos , Feminino , Envelhecimento , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Mamíferos/metabolismo , Suplementos Nutricionais
2.
Redox Biol ; 53: 102341, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35623315

RESUMO

The role of mitochondrial ROS in signalling muscle adaptations to exercise training has not been explored in detail. We investigated the effect of supplementation with the mitochondria-targeted antioxidant MitoQ on a) the skeletal muscle mitochondrial and antioxidant gene transcriptional response to acute high-intensity exercise and b) skeletal muscle mitochondrial content and function following exercise training. In a randomised, double-blind, placebo-controlled, parallel design study, 23 untrained men (age: 44 ± 7 years, VO2peak: 39.6 ± 7.9 ml/kg/min) were randomised to receive either MitoQ (20 mg/d) or a placebo for 10 days before completing a bout of high-intensity interval exercise (cycle ergometer, 10 × 60 s at VO2peak workload with 75 s rest). Blood samples and vastus lateralis muscle biopsies were collected before exercise and immediately and 3 h after exercise. Participants then completed high-intensity interval training (HIIT; 3 sessions per week for 3 weeks) and another blood sample and muscle biopsy were collected. There was no effect of acute exercise or MitoQ on systemic (plasma protein carbonyls and reduced glutathione) or skeletal muscle (mtDNA damage and 4-HNE) oxidative stress biomarkers. Acute exercise-induced increases in skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) mRNA expression were augmented in the MitoQ group. Despite this, training-induced increases in skeletal muscle mitochondrial content were similar between groups. HIIT-induced increases in VO2peak and 20 km time trial performance were also similar between groups while training-induced increases in peak power achieved during the VO2peak test were augmented in the MitoQ group. These data suggest that training-induced increases in peak power are enhanced following MitoQ supplementation, which may be related to the augmentation of skeletal muscle PGC1α expression following acute exercise. However, these effects do not appear to be related to an effect of MitoQ supplementation on exercise-induced oxidative stress or training-induced mitochondrial biogenesis in skeletal muscle.


Assuntos
Antioxidantes , Exercício Físico , Compostos Organofosforados/farmacologia , Ubiquinona/análogos & derivados , Adulto , Antioxidantes/metabolismo , Suplementos Nutricionais , Exercício Físico/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ubiquinona/farmacologia
3.
Appl Physiol Nutr Metab ; 47(7): 762-774, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35201920

RESUMO

Unaccustomed exercise causes muscle damage resulting in loss of muscle function, which may be attributable to exercise-induced increases in skeletal muscle reactive oxygen species. This study examined the effect of mitochondria-targeted antioxidant supplementation on recovery of muscle function following exercise. Thirty-two untrained men received MitoQ (20 mg/day) or a placebo for 14 days before performing  300 maximal eccentric contractions of the knee extensor muscles of 1 leg. Muscle function was assessed using isokinetic dynamometry before, immediately after, and 24, 48, 72, and 168 hours after exercise. Muscle soreness was assessed using a visual analogue scale 24, 48, 72, and 168 hours after exercise. Blood samples were collected before, immediately after, and 2, 24, 48, 72, and 168 hours after exercise and urine samples were collected before and during the 48 hours after exercise. The reduction in maximal voluntary isometric contraction force and peak concentric torque following exercise was unaffected by MitoQ while recovery of peak eccentric torque was delayed in the MitoQ group. Exercise-induced increases in urine F2-isoprostanes were unaffected by MitoQ. MitoQ augmented exercise-induced increases in plasma creatine kinase levels, while plasma IL-6 was similar between groups. Muscle soreness was not affected by MitoQ. These results indicate that MitoQ does not attenuate post-exercise muscle soreness and may delay recovery of muscle function following eccentric exercise. Trial registration number: ACTRN12620001089921. Novelty: Post-exercise recovery of maximal voluntary isometric contraction force and peak concentric torque were unaffected by MitoQ. MitoQ delayed post-exercise recovery of peak eccentric torque. Post-exercise muscle soreness was unaffected by MitoQ.


Assuntos
Contração Isométrica , Doenças Musculares , Antioxidantes/farmacologia , Creatina Quinase , Suplementos Nutricionais , F2-Isoprostanos , Humanos , Masculino , Mitocôndrias , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Mialgia/prevenção & controle , Torque
4.
J Int Soc Sports Nutr ; 18(1): 58, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419082

RESUMO

BACKGROUND: Exercise increases skeletal muscle reactive oxygen species (ROS) production, which may contribute to the onset of muscular fatigue and impair athletic performance. Mitochondria-targeted antioxidants such as MitoQ, which contains a ubiquinone moiety and is targeted to mitochondria through the addition of a lipophilic triphenylphosphonium cation, are becoming popular amongst active individuals as they are designed to accumulate within mitochondria and may provide targeted protection against exercise-induced oxidative stress. However, the effect of MitoQ supplementation on cycling performance is currently unknown. Here, we investigate whether MitoQ supplementation can improve cycling performance measured as time to complete an 8 km time trial. METHOD: In a randomized, double-blind, placebo-controlled crossover study, 19 middle-aged (age: 44 ± 4 years) recreationally trained (VO2peak: 58.5 ± 6.2 ml·kg- 1·min- 1, distance cycled per week during 6 months prior to study enrollment: 158.3 ± 58.4 km) male cyclists completed 45 min cycling at 70% VO2peak followed by an 8 km time trial after 28 days of supplementation with MitoQ (20 mg·day- 1) and a placebo. Free F2-isoprostanes were measured in plasma samples collected at rest, after 45 min cycling at 70% VO2peak and after completion of the time trial. Respiratory gases and measures of rating of perceived exertion (RPE) were also collected. RESULTS: Mean completion time for the time trial was 1.3% faster with MitoQ (12.91 ± 0.94 min) compared to placebo (13.09 ± 0.95 min, p = 0.04, 95% CI [0.05, 2.64], d = 0.2). There was no difference in RPE during the time trial between conditions (p = 0.82) despite there being a 4.4% increase in average power output during the time trial following MitoQ supplementation compared to placebo (placebo; 270 ± 51 W, MitoQ; 280 ± 53 W, p = 0.04, 95% CI [0.49, 8.22], d = 0.2). Plasma F2-isoprostanes were lower on completion of the time trial following MitoQ supplementation (35.89 ± 13.6 pg·ml- 1) compared to placebo (44.7 ± 16.9 pg·ml- 1 p = 0.03). CONCLUSION: These data suggest that MitoQ supplementation may be an effective nutritional strategy to attenuate exercise-induced increases in oxidative damage to lipids and improve cycling performance.


Assuntos
Antioxidantes/farmacologia , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Mitocôndrias Musculares/efeitos dos fármacos , Compostos Organofosforados/farmacologia , Substâncias para Melhoria do Desempenho/farmacologia , Ubiquinona/análogos & derivados , Adulto , Antioxidantes/metabolismo , Estudos Cross-Over , Método Duplo-Cego , F2-Isoprostanos/sangue , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Compostos Organofosforados/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio , Substâncias para Melhoria do Desempenho/metabolismo , Esforço Físico/efeitos dos fármacos , Esforço Físico/fisiologia , Placebos/metabolismo , Placebos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fenômenos Fisiológicos da Nutrição Esportiva/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/fisiologia , Fatores de Tempo , Ubiquinona/metabolismo , Ubiquinona/farmacologia
6.
Sci Rep ; 10(1): 17785, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082367

RESUMO

For centuries humans have been fascinated by the natural beauty of horses in motion and their different gaits. Gait classification (GC) is commonly performed through visual assessment and reliable, automated methods for real-time objective GC in horses are warranted. In this study, we used a full body network of wireless, high sampling-rate sensors combined with machine learning to fully automatically classify gait. Using data from 120 horses of four different domestic breeds, equipped with seven motion sensors, we included 7576 strides from eight different gaits. GC was trained using several machine-learning approaches, both from feature-extracted data and from raw sensor data. Our best GC model achieved 97% accuracy. Our technique facilitated accurate, GC that enables in-depth biomechanical studies and allows for highly accurate phenotyping of gait for genetic research and breeding. Our approach lends itself for potential use in other quadrupedal species without the need for developing gait/animal specific algorithms.


Assuntos
Automação/métodos , Simulação por Computador , Marcha , Cavalos , Processamento de Imagem Assistida por Computador/métodos , Coxeadura Animal/diagnóstico , Aprendizado de Máquina , Algoritmos , Animais , Fenômenos Biomecânicos , Movimento (Física) , Fenótipo
8.
J Environ Qual ; 43(2): 723-31, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25602673

RESUMO

Previous work has estimated the hydroperiod requirements (saturation duration and frequency) of wetland plant communities by modeling their hydrologic regimes in natural (never drained) wetlands for a 40-yr period. This study tested the modeled predictions in a controlled greenhouse study using tree species representing three of the plant communities plus an additional species from another community. Bald cypress ( L. Rich.), sweet bay ( L.), pond pine ( Michx.), and swamp chestnut oak ( Nutt.) were grown under three hydroperiods (continuously ponded for 100 d, intermittently ponded for 14 d, and unsaturated) in loamy sand and sapric (organic) materials. Bald cypress (representing a Nonriverine Swamp Forest community) adapted well to 100 d of ponding by producing lateral roots near the soil surface and aerenchyma tissue in roots and stem. Sweet bay (Bay Forest community) also adapted well to 100 d of ponding by producing adventitious roots on the submerged portion of the stem. Pond pine (Pond Pine Woodland) and swamp chestnut oak (Nonriverine Wet Hardwood Forest) were intolerant of 100 d of ponded conditions. Seventy-five percent of the pond pine seedlings and 87% of the swamp chestnut oak seedlings died in the continuously ponded treatment level, whereas 100% of the bald cypress and 88% of the sweet bay seedlings survived. Results from this study suggest that modeled long-term hydroperiods of natural wetland plant communities can be used for restoration of these communities.

9.
Anaesth Intensive Care ; 35(1): 94-8, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17323674

RESUMO

Omphalocele is one of the most common fetal abdominal wall defects. When this defect is of giant size, significant respiratory compromise may occur and impact on prognosis. We present three infants with giant omphalocele, highlighting the potential need for ongoing ventilatory support after the neonatal period in children born with this condition. The three cases had very different outcomes but all had significant ventilatory insufficiency and required substantial respiratory support at least into the second year of life. The possibility of a requirement for long-term ventilatory support should be discussed with families at antenatal diagnosis. A conservative surgical approach, together with early monitoring for hypoventilation and screening for the development of pulmonary hypertension is indicated for these children to limit morbidity. We suggest early tertiary respiratory input and advocate for a specific case manager to oversee the regional care of these children.


Assuntos
Hérnia Umbilical/complicações , Respiração com Pressão Positiva , Insuficiência Respiratória/terapia , Feminino , Hérnia Umbilical/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido de Baixo Peso , Recém-Nascido , Masculino , Prognóstico , Radiografia , Insuficiência Respiratória/etiologia
10.
Pediatr Pulmonol ; 39(3): 238-46, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15635620

RESUMO

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.


Assuntos
Depuração Mucociliar/fisiologia , Óxido Nítrico/metabolismo , Grupos Populacionais/estatística & dados numéricos , Doenças Respiratórias/etnologia , Doenças Respiratórias/fisiopatologia , Adolescente , Asma/etnologia , Asma/fisiopatologia , Testes Respiratórios , Bronquite/etnologia , Bronquite/fisiopatologia , Criança , Pré-Escolar , Cílios/patologia , Cílios/fisiologia , Europa (Continente)/etnologia , Predisposição Genética para Doença/epidemiologia , Humanos , Mucosa Nasal/fisiologia , Mucosa Nasal/fisiopatologia , Havaiano Nativo ou Outro Ilhéu do Pacífico/estatística & dados numéricos , Nova Zelândia/epidemiologia , Estudos Prospectivos , Valores de Referência , Testes de Função Respiratória , Hipersensibilidade Respiratória/etnologia , Hipersensibilidade Respiratória/fisiopatologia , Doenças Respiratórias/diagnóstico , Doenças Respiratórias/genética , Testes Cutâneos , População Branca/estatística & dados numéricos
11.
Vaccine ; 17(22): 2826-9, 1999 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-10438052

RESUMO

This study was designed to determine the safety and immunogenicity in volunteers of a DNA vaccine consisting of a plasmid encoding hepatitis B surface antigen delivered by the PowderJect XR1 gene delivery system into human skin. Seven healthy adult volunteers received two immunizations at one of three forces of delivery on day 0 and 56. The vaccine was well tolerated. One of six seronegative volunteers developed high titers of persistent HBsAb after a single immunization. In retrospect, this volunteer may have had previous exposure to hepatitis B. Our study suggests that the hepatitis B DNA vaccine given by this gene delivery system may induce a booster response, but the vaccine at the extremely low DNA dose used (0.25 microg) did not induce primary immune responses.


Assuntos
Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/uso terapêutico , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Vacinas de DNA/uso terapêutico , Adolescente , Adulto , Anticorpos Antivirais/sangue , DNA Viral/efeitos adversos , DNA Viral/uso terapêutico , Sistemas de Liberação de Medicamentos/efeitos adversos , Vacinas contra Hepatite B/efeitos adversos , Humanos , Imunidade nas Mucosas/imunologia , Injeções Intradérmicas/efeitos adversos , Pessoa de Meia-Idade , Vacinas de DNA/efeitos adversos
17.
Biotechniques ; 8(4): 370-1, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1692715

RESUMO

We describe a simplified Northern blot hybridization procedure. This procedure eliminates the need for many reagents commonly used in RNA hybridization and replaces them with two buffers containing 5% sodium dodecyl sulfate for pre-hybridization, hybridization and all post-hybridization washes.


Assuntos
Dodecilsulfato de Sódio , Animais , Northern Blotting/métodos , Sondas de DNA , Camundongos , Hibridização de Ácido Nucleico , RNA/análise
18.
Development ; 104(1): 137-45, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3075542

RESUMO

Homologous serum, when repeatedly used for the culture of postimplantation rat embryos, rapidly loses its capacity to support growth and development. Replenishment of the 'exhausted' serum with glucose and vitamins (MEM vitamin concentrate--Flow Laboratories) together with gentle dialysis to remove small molecular weight toxic metabolites (lactate etc) fails to restore the growth-promoting properties of the serum. This suggests that 'recycled' serum has been depleted of specific growth-promoting factors. Such serum that has been subjected to dialysis can be completely replenished by addition of 30% normal rat serum. It is therefore probable that the growth promoters are originally present at very low concentrations and become rate limiting when serum is recycled. Many growth factors and hormones fall into this category and it is likely that a considerable number are involved when serum is 'exhausted' by repeated use. When insulin, epidermal growth factor or rat transferrin are added to dialysed 'exhausted' serum each effects a partial restoration of growth of rat embryos.


Assuntos
Meios de Cultura , Embrião de Mamíferos/fisiologia , Fator de Crescimento Epidérmico/farmacologia , Insulina/farmacologia , Transferrina/farmacologia , Animais , Sangue , Células Cultivadas , Feminino , Gravidez , Ratos , Ratos Endogâmicos
19.
Cell ; 40(3): 537-46, 1985 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2982497

RESUMO

Rous sarcoma virus expresses a transcriptional activator that affects the LTR as well as other promoters. We discern this activity as a stimulation of the transient expression of an LTR-promoted hybrid transcriptional unit and also of the rat preproinsulin II gene in transfected NIH 3T3 cells. We map the activity to an alternate reading frame in the p19-p10 region of the gag gene and identify a mRNA whose spliced structure would direct translation of this reading frame from the Pr76gag initiation codon. This mRNA probably differs from genomic RNA only by the 282 nucleotide splice. The predicted translation product is a 124 residue polypeptide; the first six amino acids arise from gag. The target for the action of this transcriptional modulator at the LTR lies between 111 and 620 nucleotides upstream of the cap site.


Assuntos
Vírus do Sarcoma Aviário/genética , Fatores de Transcrição/genética , Animais , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Genes Virais , Insulina , Camundongos , Hibridização de Ácido Nucleico , Plasmídeos , Proinsulina/genética , Regiões Promotoras Genéticas , Biossíntese de Proteínas , Precursores de Proteínas/genética , RNA Mensageiro/genética , RNA Viral/genética , Ratos , Sequências Repetitivas de Ácido Nucleico , Transcrição Gênica , Transfecção
20.
Methods Find Exp Clin Pharmacol ; 7(2): 65-8, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2985893

RESUMO

This study was designed to determine the mechanism of action of 2'-, 3'- and 5'-substituted adenine nucleotides on cholinergic transmission in guinea-pig ileum. Segments of ileum were continuously stimulated at 0.2 Hz and IC50 values of nucleotides for inhibition of twitch responses determined. All the nucleotides studied inhibited transmission, the effect being antagonised by 30 X 10(-6) M theophylline. The inhibitors of nucleoside transport, HNBTGR and dipyridamole, potentiated responses to all the nucleotides. Addition of adenosine deaminase reduced responses only to adenosine and 5'-AMP, while inhibition of adenosine deaminase with deoxycoformycin potentiated responses only to 5'-AMP and 5'-ADP. It was concluded that all the nucleotides studied inhibit cholinergic transmission through an action at P1-purinoceptors. However, it was not possible from this study to conclude whether these actions were direct or indirect following their hydrolysis to adenosine.


Assuntos
Nucleotídeos de Adenina/farmacologia , Íleo/efeitos dos fármacos , Parassimpatolíticos , Transmissão Sináptica/efeitos dos fármacos , Animais , Fibras Colinérgicas/efeitos dos fármacos , Depressão Química , Cobaias , Íleo/inervação , Técnicas In Vitro
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