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1.
J Endocrinol Invest ; 47(9): 2249-2260, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38460092

RESUMO

BACKGROUND: The organ-specific effects of gender-affirming sex hormone treatment (GAHT) in transgender women (TW) and transgender men (TM) are insufficiently explored. This study investigated the effects of GAHT on adipose tissue function. METHODS: In a single-center interventional prospective study, 32 adults undergoing GAHT, 15 TW and 17 TM, were examined with anthropometry and abdominal subcutaneous adipose tissue biopsies obtained before initiation of treatment, 1 month after endogenous sex hormone inhibition and three and 11 months after initiated GAHT. Fat cell size, basal/stimulated lipolysis and cytokine secretion in adipose tissue were analyzed. RESULTS: TW displayed an increase in complement component 3a and retinol-binding protein 4 (RBP4) secretion after sex hormone inhibition, which returned to baseline following estradiol treatment. No changes in lipolysis were seen in TW. TM showed downregulation of RBP4 after treatment, but no changes in basal lipolysis. In TM, the estrogen suppression led to higher noradrenaline stimulated (NA) lipolysis that was normalized following testosterone treatment. At 11 months, the ratio of NA/basal lipolysis was lower compared to baseline. There were no significant changes in fat cell size in either TW or TM. CONCLUSION: In TW, gonadal hormone suppression results in transient changes in cytokines and in TM there are some changes in NA-stimulated lipolysis following testosterone treatment. However, despite the known metabolic effects of sex hormones, the overall effects of GAHT on adipose tissue function are small and likely have limited clinical relevance, but larger studies with longer follow-up are needed to confirm these findings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02518009, Retrospectively registered 7 August 2015.


Assuntos
Adipocinas , Lipólise , Pessoas Transgênero , Humanos , Lipólise/efeitos dos fármacos , Feminino , Masculino , Adulto , Estudos Prospectivos , Adipocinas/metabolismo , Procedimentos de Readequação Sexual/métodos , Testosterona , Hormônios Esteroides Gonadais , Pessoa de Meia-Idade , Adulto Jovem , Seguimentos
2.
Lupus ; 25(14): 1602-1609, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27334936

RESUMO

OBJECTIVE: The aim of this study was to investigate the role of dietary micronutrient intake in systemic lupus erythematosus (SLE). METHODS: This study included 111 SLE patients and 118 age and gender-matched controls. Data on diet (food frequency questionnaires) were linked with data on Systemic Lupus Activity Measure, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and carotid atherosclerotic/echolucent plaque (B-mode ultrasound). Dietary micronutrient intake were compared between SLE patients and controls and in relation to lupus activity and atherosclerosis in SLE. Associations between micronutrient intake and plaque were analyzed through logistic regression, adjusted for potential confounders. RESULTS: Micronutrient intake did not differ between patients and controls, and between lower and higher lupus activity, apart from the fact that phosphorus was associated with SLEDAI > 6. In SLE patients, some micronutrients were associated with atherosclerotic plaque, left side. Lower intake of riboflavin and phosphorus was associated with atherosclerotic plaque, left side (odds ratio (OR) 3.06, 95% confidence interval (CI) 1.12-8.40 and OR 4.36, 95% CI 1.53-12.39, respectively). Higher intake of selenium and thiamin was inversely associated with atherosclerotic plaque, left side (OR 0.28, 95% CI 0.09-0.89 and OR 0.26, 95% CI 0.08-0.80, respectively). In addition, higher intake of thiamin was inversely associated with echolucent plaque, left side (OR 0.22, 95% CI 0.06-0.84). Lower intake of folate was inversely associated with bilateral echolucent plaque (OR 0.36, 95% CI 0.13-0.99). CONCLUSIONS: SLE patients did not have different dietary micronutrient intake compared to controls. Phosphorus was associated with lupus activity. Riboflavin, phosphorus, selenium and thiamin were inversely associated with atherosclerotic plaque, left side in SLE patients, but not in controls. Dietary micronutrients may play a role in atherosclerosis in SLE.


Assuntos
Aterosclerose/epidemiologia , Dieta , Lúpus Eritematoso Sistêmico/complicações , Micronutrientes/análise , Adulto , Aterosclerose/etiologia , Artérias Carótidas/diagnóstico por imagem , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fósforo/análise , Placa Aterosclerótica/diagnóstico por imagem , Riboflavina/análise , Fatores de Risco , Selênio/análise , Índice de Gravidade de Doença , Suécia , Tiamina/análise , Ultrassonografia
3.
Am J Physiol Regul Integr Comp Physiol ; 307(3): R248-55, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24898836

RESUMO

The transcription factor hypoxia-inducible factor (HIF) has been suggested as a candidate for mediating training adaptation in skeletal muscle. However, recent evidence rather associates HIF attenuation with a trained phenotype. For example, a muscle-specific HIF deletion increases endurance performance, partly through decreased levels of pyruvate dehydrogenase kinase 1 (PDK-1). HIF activity is regulated on multiple levels: modulation of protein stability, transactivation capacity, and target gene availability. Prolyl hydroxylases (PHD1-3) induces HIF degradation, whereas factor-inhibiting HIF (FIH) and the histone deacetylase sirtuin-6 (SIRT6) repress its transcriptional activity. Together, these negative regulators introduce a mechanism for moderating HIF activity in vivo. We hypothesized that long-term training induces their expression. Negative regulators of HIF were explored by comparing skeletal muscle tissue from moderately active individuals (MA) with elite athletes (EA). In elite athletes, expression of the negative regulators PHD2 (MA 73.54 ± 9.54, EA 98.03 ± 6.58), FIH (MA 4.31 ± 0.25, EA 30.96 ± 7.99) and SIRT6 (MA 0.24 ± 0.07, EA 11.42 ± 2.22) were all significantly higher, whereas the response gene, PDK-1 was lower (MA 0.12 ± 0.03, EA 0.04 ± 0.01). Similar results were observed in a separate 6-wk training study. In vitro, activation of HIF in human primary muscle cell culture by PHD inactivation strongly induced PDK-1 (0.84 ± 0.12 vs 4.70 ± 0.63), providing evidence of a regulatory link between PHD activity and PDK-1 levels in a relevant model system. Citrate synthase activity, closely associated with aerobic exercise adaptation, increased upon PDK-1 silencing. We suggest that training-induced negative regulation of HIF mediates the attenuation of PDK-1 and contributes to skeletal muscle adaptation to exercise.


Assuntos
Atletas , Metabolismo Energético/fisiologia , Regulação da Expressão Gênica/fisiologia , Fator 1 Induzível por Hipóxia/genética , Fator 1 Induzível por Hipóxia/metabolismo , Músculo Esquelético/metabolismo , Resistência Física/fisiologia , Adaptação Fisiológica/fisiologia , Biópsia , Células Cultivadas , Estudos Transversais , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Técnicas In Vitro , Estudos Longitudinais , Masculino , Músculo Esquelético/patologia , Oxirredução , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil , Transdução de Sinais/fisiologia , Sirtuínas/metabolismo , Adulto Jovem
4.
Phys Chem Chem Phys ; 16(8): 3846-52, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24434789

RESUMO

We employ soft X-ray absorption spectroscopy and resonant inelastic X-ray scattering spectroscopy to study the redox behavior in the first lithiation/delithiation cycle of Li(2-x)MnSiO4 (4.0-4.6 V). For extraction of lithium ions up to an end potential of 4.1 V, we do not detect any change in the oxidation state for the expected redox-active Mn atom, instead the electronic structure of the Si-O network is affected. Above 4.1 V, there is an abrupt change in the oxidation state of the Mn-ions, from 2+ to 4+, which is accompanied by a complete loss of long range order in the material, as detected by X-ray diffraction. Further lithium extraction leads to progressive loss of crystallinity of Li(2-x)MnSiO4, rather than formation of a new structure, explaining the measured first-cycle capacity loss of this material. Our results suggest that future improvement of the crystalline stability of the material, particularly with respect to the SiO4 network, is required to harness the full charge capacity of Li(2-x)MnSiO4.

5.
Eur J Appl Physiol ; 113(5): 1249-55, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23160657

RESUMO

Matrix metalloproteinase 9 (MMP-9) is a member of a family of zinc-dependent endopeptidases capable of degrading extracellular matrix (ECM) proteins. A single bout of exercise increases levels of activated MMP-9 in skeletal muscle and in the circulation. However, whether the exercise-induced activation of MMP-9 is associated with ECM remodeling and the cellular source behind MMP-9 in the circulation is not known. In the present study ten healthy male subjects performed a single cycle exercise bout and arterial and venous femoral blood was collected. To test if exercise induces basal lamina degradation and if circulating levels of MMP-9 is related to a release from the exercising muscle, arteriovenous differences of collagen IV and MMP-9 were measured by ELISA and zymography, respectively. Furthermore, markers of neutrophil degranulation elastase and neutrophil gelatinase-associated lipocalin (NGAL) were measured by ELISA. Plasma levels of collagen IV increased during the exercise bout and an increased arteriovenous difference of collagen IV was noted at 27 min of exercise. Plasma levels of MMP-9 were increased at both 27 and 57 min of exercise but no arteriovenous difference was noted. No changes over time were detected for elastase and NGAL. The observed release of collagen IV from the exercising muscle indicate basal lamina turnover following a single bout of exercise. No detectable release of MMP-9 was observed, suggesting that the increase in plasma MMP-9 could come from a source other than the skeletal muscle.


Assuntos
Exercício Físico , Metaloproteinase 9 da Matriz/sangue , Proteínas de Fase Aguda , Adolescente , Adulto , Membrana Basal/enzimologia , Membrana Basal/metabolismo , Colágeno Tipo IV/sangue , Endotélio Vascular/enzimologia , Endotélio Vascular/metabolismo , Matriz Extracelular/metabolismo , Humanos , Elastase de Leucócito/sangue , Lipocalina-2 , Lipocalinas/sangue , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Neutrófilos/enzimologia , Proteínas Proto-Oncogênicas/sangue
6.
Lupus ; 21(8): 815-20, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22415927

RESUMO

BACKGROUND: The risk of cardiovascular disease (CVD), microangiopathy and prevalence of atherosclerotic plaques are increased in Systemic Lupus Erythematosus (SLE). As systemic endothelial dysfunction is one of the earliest signs of these vascular outcomes in the general population we assessed skin microvascular endothelial function in SLE patients. METHODS: Endothelial function in skin was tested with local application of acetylcholine (inducing endothelium-dependent vasodilatation) and any concomitant increase in skin perfusion was measured with Laser Doppler Fluxmetry (LDF) in 84 SLE-patients (83% women, mean age 47 years) and 81 age and sex matched controls. Common carotid intima-media thickness (cIMT) and plaque occurrence were also determined using B-mode ultrasound. RESULTS: There were no significant differences in skin microvascular endothelial function between SLE-patients and controls. In the SLE group, endothelial function did not vary in relation to skin manifestations, Raynaud's phenomenon, nephritis or plaque occurrence. In SLE patients with CVD, however, endothelial function was impaired. CONCLUSION: Skin microvascular endothelial function is associated with CVD but not with early signs of atherosclerosis in SLE-patients. The endothelial function is not different in SLE-patients as compared to controls.


Assuntos
Aterosclerose/fisiopatologia , Endotélio Vascular/fisiopatologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Microcirculação , Pele/irrigação sanguínea , Acetilcolina/administração & dosagem , Adulto , Aterosclerose/complicações , Espessura Intima-Media Carotídea , Estenose das Carótidas/complicações , Estenose das Carótidas/fisiopatologia , Feminino , Humanos , Iontoforese , Lasers , Lúpus Eritematoso Sistêmico/complicações , Masculino , Pessoa de Meia-Idade , Nefrite/fisiopatologia , Doença de Raynaud/fisiopatologia , Estatísticas não Paramétricas , Vasodilatadores/administração & dosagem
7.
Lupus ; 21(13): 1405-11, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22930204

RESUMO

OBJECTIVE: As atherosclerosis is increased in systemic lupus erythematosus (SLE) we compared dietary habits in patients with SLE with controls, and in the patients studied associations of diet components, especially fatty acids (FAs), with disease activity, serum lipids and carotid plaque presence. METHODS: In all 114 patients with SLE and 122 age- and sex-matched population-based controls answered a food frequency questionnaire (FFQ). Subcutaneous abdominal fat cell aspiration was analysed as to FA content and plaque occurrence was determined by B-mode ultrasound. RESULTS: The total diet energy intake did not differ between patients and controls. However, the patients with SLE reported a higher intake of carbohydrate, lower fibre intake and lower intake of omega-3 and omega-6, than controls (p < 0.05). In the patients, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in adipose tissue (AT) correlated negatively with disease activity (SLEDAI), r = -0.36, p = < 0.001 and r = -0.33, p = < 0.001, respectively. AT omega-3 was further positively associated with serum apoA1, r = 0.29, p = 0.004, whereas AT omega-6 showed a negative association, r = -0.21, p = 0.040. These FAs also had opposite associations with plaque presence, EPA and were DHA negative, r = -0.32, p = 0.002 and r = -0.33, p = 0.001, respectively, and omega-6 positive, r = 0.22, p = 0.027. The carbohydrate intake was positively correlated to AT omega-6, r = 0.38, p < 0.001, and negatively with serum apoA1, r = -0.27, p = 0.005. CONCLUSION: The macronutrient dietary pattern is different in SLE as compared with controls. The low intake of omega-3 and high intake of carbohydrate among patients with SLE appear to be associated with worse disease activity, adverse serum lipids and plaque presence.


Assuntos
Artérias Carótidas/patologia , Doenças das Artérias Carótidas/sangue , Gorduras na Dieta/sangue , Ácidos Graxos/sangue , Comportamento Alimentar , Lúpus Eritematoso Sistêmico/sangue , Gordura Abdominal/metabolismo , Apolipoproteína A-I/sangue , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Estudos Transversais , Carboidratos da Dieta/metabolismo , Fibras na Dieta/metabolismo , Ingestão de Energia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica , Índice de Gravidade de Doença , Inquéritos e Questionários , Ultrassonografia Doppler Dupla
8.
Am J Physiol Endocrinol Metab ; 301(6): E1092-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21862727

RESUMO

The present study investigated whether exercise induces the expression of PGC-1α splice variants in human skeletal muscle and the possible influence of metabolic perturbation on this response. The subjects exercised one leg for 45 min with restricted blood flow (R-leg), followed by 45 min of exercise using the other leg at the same absolute workload but with normal blood flow (NR-leg). This ischemic model (R-leg) has been shown previously to induce a greater metabolic perturbation and enhance the expression of PGC-1α beyond that observed in the NR-leg. Cultured human myotubes were used to test suggested exercise-induced regulatory stimuli of PGC-1α. We showed, for the first time, that transcripts from both the canonical promoter (PGC-1α-a) and the proposed upstream-located promoter (PGC-1α-b) are present in human skeletal muscle. Both transcripts were upregulated after exercise in the R-leg, but the fold change increase of PGC-1α-b was much greater than that of PGC-1α-a. No differences were observed between the two conditions regarding the marker for calcineurin activation, MCIP1, or p38 phosphorylation. AMPK phosphorylation increased to a greater extent in the R-leg, and AICAR stimulation of cultured human myotubes induced the expression of PGC-1α-a and PGC-1α-b. AICAR combined with norepinephrine yielded an additive effect on the PGC-1α-b expression only. Our results indicate clearly that exercise can activate an upstream promoter in humans and support AMPK as a major regulator of transcripts from the canonical PGC-1α promoter and the involvement of ß-adrenergic stimulation in combination with AMPK in the regulation of PGC-1α-b.


Assuntos
Processamento Alternativo , Proteínas de Transporte/genética , Exercício Físico/fisiologia , Proteínas de Choque Térmico/genética , Músculo Esquelético/metabolismo , Fatores de Transcrição/genética , Adenilato Quinase/metabolismo , Adenilato Quinase/fisiologia , Adulto , Processamento Alternativo/efeitos dos fármacos , Processamento Alternativo/genética , Processamento Alternativo/fisiologia , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Biópsia , Proteínas de Transporte/metabolismo , Células Cultivadas , Proteínas de Choque Térmico/metabolismo , Humanos , Masculino , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Cultura Primária de Células , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA , Ribonucleotídeos/farmacologia , Fatores de Transcrição/metabolismo , Regulação para Cima/fisiologia , Adulto Jovem
9.
Phys Chem Chem Phys ; 13(45): 20215-22, 2011 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-21984023

RESUMO

We present a study of the charge-state behavior of the Li-ion battery cathode materials Li(x)MnPO(4) and Li(x)Mn(0.9)Fe(0.1)PO(4) using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). A set of six identical battery cathodes for each material have been cycled and left in different charge states in the range of x = 0.2…1.0 before disassembly in an Ar glove box. Unexpectedly, we find that the Mn 3d-bands are almost inert to the delithiation process, suggesting that Mn ions participate to a very small extent in the charge compensation process. In Li(x)Mn(0.9)Fe(0.1)PO(4) the Fe 3d-band shows much more response to delithiation than the Mn 3d-band. The O 2p-band hybridizes with the bands of the other ions in Li(x)MnPO(4) and Li(x)Mn(0.9)Fe(0.1)PO(4) and thus, indirectly, carries useful information about the effects of delithiation at all ion sites. We conclude that the redox reactions during lithiation/delithiation of these materials are complex and involve repopulation of charges for all constituent elements.

10.
Phys Chem Chem Phys ; 13(14): 6544-51, 2011 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-21390362

RESUMO

We have studied the first lithiation/delithiation cycle of the Li-ion battery electrode material Li(x)Ni(0.25)TiOPO(4) applying X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). A set of ten identical Li(x)Ni(0.25)TiOPO(4) battery electrodes have been cycled and left in different states of charge in the range of x = 0.5 … 2.5, before disassembly in an Ar filled glove box. We find that Ni-, Ti-, and O-ions are affected simultaneously, rather than sequentially, upon lithiation of the material. In particular, Ni is reduced from Ni(2+) to Ni(0) but only partially re-oxidized to Ni(1+), again, by delithiation. Overall, there is considerable "crosstalk" between the different atomic species and non-linearity in the response of the electronic structure during the lithiation/delithiation process. Fortuitously, the background variation in Ni L-XAS shows to contain valuable information about solid-electrolyte interface (SEI) creation, showing that the SEI is a function of the degree of lithiation.

11.
Int J Pharm ; 595: 120197, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33486041

RESUMO

Oral films (OFs) continue to attract attention as drug delivery systems, particularly for pedatric and geriatric needs. However, immiscibility between different polymers limits the full potential of OFs from being explored. One example is pullulan (PUL), a novel biopolymer which often has to be blended with other polymers to reduce cost and alter its mechanical properties. In this study, the state-of-the-art in fabrication techniques, three-dimensional (3D) printing was used to produce hybrid film structures of PUL and hydroxypropyl methylcellulose (HPMC), which were loaded with caffeine as a model drug. 3D printing was used to control the spatial deposition of films. HPMC was found to increase the mean mechanical properties of PUL films, where the tensile strength, elastic modulus and elongation break increased from 8.9 to 14.5 MPa, 1.17 to 1.56 GPa and from 1.48% to 1.77%, respectively. In addition, the spatial orientation of the hybrid films was also explored to determine which orientation could maximize the mechanical properties of the hybrid films. The results revealed that 3D printing could modify the mechanical properties of PUL whilst circumventing the issues associated with immiscibility.


Assuntos
Glucanos/química , Derivados da Hipromelose/química , Impressão Tridimensional , Tecnologia Farmacêutica/métodos , Administração Oral , Formas de Dosagem , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Elasticidade , Pressão , Reologia/métodos , Resistência à Tração , Viscosidade
12.
J Intern Med ; 268(2): 194-205, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20528971

RESUMO

OBJECTIVE: The importance of adiponectin in coronary heart disease remains to be elucidated. Therefore, the associations between plasma adiponectin levels and i) myocardial infarction and ii) genetic variation within the adiponectin gene were investigated. METHODS: The study included young survivors (age <60 years) of a first myocardial infarction and gender- and age-matched controls (244 pairs). Adiponectin concentrations were analysed by radioimmunoassay. Two polymorphisms, rs266729 and rs1501299, of the adiponectin gene ADIPOQ were genotyped. RESULTS: Adiponectin levels were inversely associated with myocardial infarction [odds ratio (OR) 9.3, 95% confidence interval (CI) 4.7-18.2, for the lowest quartile compared to the highest quartile]. This persisted after adjustment for history of hypertension, HDL cholesterol, smoking and body mass index (BMI) (OR 3.1, 95% CI 1.3-7.6). The rs266729 polymorphism was associated with adiponectin levels. Plasma adiponectin concentrations were lower in individuals with the rare G/G genotype [median 4.3 mg/L, [corrected] interquartile range (IQR) 2.8-6.2] compared to the C/G (median 5.8 mg/L), [corrected] IQR 3.9-8.0; P = 0.035) and C/C genotypes (median 5.5 mg/L, [corrected] IQR 4.0-7.5; P = 0.083). CONCLUSION: Low plasma adiponectin concentrations are associated with myocardial infarction in individuals below the age of 60, and this remains significant after adjustment for history of hypertension, HDL cholesterol, smoking and BMI. In addition, adiponectin levels differ according to rs266729 genotype.


Assuntos
Adiponectina/sangue , Infarto do Miocárdio/sangue , Adiponectina/genética , Biomarcadores/sangue , Proteína C-Reativa/análise , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Fatores de Risco
13.
J Frailty Aging ; 9(1): 57-63, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32150215

RESUMO

BACKGROUND: Human aging is characterized by a chronic, low-grade inflammation suspected to contribute to reductions in skeletal muscle size, strength, and function. Inflammatory cytokines, such as interleukin-6 (IL-6), may play a role in the reduced skeletal muscle adaptive response seen in older individuals. OBJECTIVES: To investigate relationships between circulating IL-6, skeletal muscle health and exercise adaptation in mobility-limited older adults. DESIGN: Randomized controlled trial. SETTING: Exercise laboratory on the Health Sciences campus of an urban university. PARTICIPANTS: 99 mobility-limited (Short Physical Performance Battery (SPPB) ≤9) older adults. INTERVENTION: 6-month structured physical activity with or without a protein and vitamin D nutritional supplement. MEASUREMENTS: Circulating IL-6, skeletal muscle size, composition (percent normal density muscle tissue), strength, power, and specific force (strength/CSA) as well as physical function (gait speed, stair climb time, SPPB-score) were measured pre- and post-intervention. RESULTS: At baseline, Spearman's correlations demonstrated an inverse relationship (P<0.05) between circulating IL-6 and thigh muscle composition (r = -0.201), strength (r = -0.311), power (r = -0.210), and specific force (r = -0.248), and positive association between IL-6 and stair climb time (r = 0.256; P<0.05). Although the training program did not affect circulating IL-6 levels (P=0.69), reductions in IL-6 were associated with gait speed improvements (r = -0.487; P<0.05) in "higher" IL-6 individuals (>1.36 pg/ml). Moreover, baseline IL-6 was inversely associated (P<0.05) with gains in appendicular lean mass and improvements in SPPB score (r = -0.211 and -0.237, respectively). CONCLUSIONS: These findings implicate age-related increases in circulating IL-6 as an important contributor to declines in skeletal muscle strength, quality, function, and training-mediated adaptation. Given the pervasive nature of inflammation among older adults, novel therapeutic strategies to reduce IL-6 as a means of preserving skeletal muscle health are enticing.


Assuntos
Exercício Físico/fisiologia , Interleucina-6/sangue , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Idoso , Humanos , Limitação da Mobilidade
14.
Science ; 246(4926): 99-100, 1989 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-17837766

RESUMO

The scanning tunneling microscope has been used to image and modify the surface of a conducting oxide (Rb(0.3)MoO(3))in ambient atmosphere. Individual octahedral MoO(6) units of the oxide can be imaged, and under certain conditions defects can be created in the surface that are stable in air. The ability to produce nanometer-sized structures on the surface of an oxide is demonstrated and discussed with reference to nanolithographic applications.

15.
Obes Sci Pract ; 5(2): 130-140, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31019730

RESUMO

AIM: Use of the glucagon-like peptide 1 receptor agonist liraglutide has been shown to reduce weight. Different types of anthropometric measurements can be used to measure adiposity. This study evaluated the effect of liraglutide on sagittal abdominal diameter, waist circumference, waist-to-hip ratio and adiponectin levels in people with type 2 diabetes (T2D) treated with multiple daily insulin injections (MDI). MATERIALS AND METHODS: In the multicentre, double-blind, placebo-controlled MDI-liraglutide trial, 124 individuals with T2D treated with MDI were randomized to either liraglutide or placebo. Basal values of weight, waist circumference, waist-to-hip ratio, sagittal abdominal diameter and adiponectin were compared with measurements at 12 and 24 weeks after randomization. RESULTS: Baseline-adjusted mean weight loss was 3.8 ± 2.9 kg greater in liraglutide than placebo-treated individuals (p < 0.0001). Waist circumference was reduced by 2.9 ± 4.3 cm and 0.2 ± 3.6 cm in the liraglutide and placebo groups, respectively, after 24 weeks (baseline-adjusted mean difference: 2.6 ± 4.0 cm, p = 0.0005). Corresponding reductions in sagittal abdominal diameter were 1.1 ± 1.7 cm and 0.0 ± 1.8 cm (baseline-adjusted mean difference: 1.1 ± 1.7 cm, p = 0.0008). Hip circumference was reduced in patients randomized to liraglutide (baseline-adjusted mean difference between treatment groups: 2.8 ± 3.8 cm, p = 0.0001), but there was no significant difference between the groups in either waist-to-hip ratio (baseline-adjusted mean difference: 0.0 ± 0.04 cm, p = 0.51) or adiponectin levels (baseline-adjusted mean difference: 0.8 ± 3.3 mg L-1, p = 0.17). Lower HbA1c and mean glucose levels measured by masked continuous glucose monitoring at baseline were associated with greater effects of liraglutide on reductions in waist circumference and sagittal abdominal diameter. CONCLUSIONS: In patients with T2D, adding liraglutide to MDI may reduce abdominal and hip obesity to a similar extent, suggesting an effect on both visceral and subcutaneous fat. Liraglutide had greater effects on reducing abdominal obesity in patients with less pronounced long-term hyperglycaemia but did not affect adiponectin levels.

16.
Regul Pept ; 149(1-3): 32-8, 2008 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-18534696

RESUMO

Physiological control of feeding is mediated by tonic and episodic signalling systems. These are sometimes thought of as long-term and short-term control. Tonic signals arise from tissue stores whereas episodic signals oscillate periodically with the consumption of food. These physiological controls are paralleled in the motivation to eat by long-acting enduring traits (such as disinhibition) and by short-acting states (such as hunger). Peptides are usually envisaged to exert an action on appetite control through the modulation of states such as hunger and satiety (fullness). Here we provide evidence that peptides involved in tonic regulation--such as leptin--may express a control over appetite motivation through an effect on traits that confer a constant readiness to eat, whereas episodic peptides such as GLP-1 influence appetite motivation through a state such as hunger. The distinction between tonic and episodic regulation, and between traits and states has implications for understanding overconsumption and the susceptibility to weight gain.


Assuntos
Obesidade , Peptídeos/fisiologia , Aumento de Peso/fisiologia , Apetite/fisiologia , Feminino , Humanos , Modelos Biológicos
17.
Acta Physiol (Oxf) ; 222(2)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28834248

RESUMO

AIMS: This study tested the hypothesis that high doses of anti-inflammatory drugs would attenuate the adaptive response to resistance training compared with low doses. METHODS: Healthy men and women (aged 18-35 years) were randomly assigned to daily consumption of ibuprofen (IBU; 1200 mg; n = 15) or acetylsalicylic acid (ASA; 75 mg; n = 16) for 8 weeks. During this period, subjects completed supervised knee-extensor resistance training where one leg was subjected to training with maximal volitional effort in each repetition using a flywheel ergometer (FW), while the other leg performed conventional (work-matched across groups) weight-stack training (WS). Before and after training, muscle volume (MRI) and strength were assessed, and muscle biopsies were analysed for gene and protein expression of muscle growth regulators. RESULTS: The increase in m. quadriceps volume was similar between FW and WS, yet was (averaged across legs) greater in ASA (7.5%) compared with IBU (3.7%, group difference 34 cm3 ; P = 0.029). In the WS leg, muscle strength improved similarly (11-20%) across groups. In the FW leg, increases (10-23%) in muscle strength were evident in both groups yet they were generally greater (interaction effects P < 0.05) for ASA compared with IBU. While our molecular analysis revealed several training effects, the only group interaction (P < 0.0001) arose from a downregulated mRNA expression of IL-6 in IBU. CONCLUSION: Maximal over-the-counter doses of ibuprofen attenuate strength and muscle hypertrophic adaptations to 8 weeks of resistance training in young adults. Thus, young individuals using resistance training to maximize muscle growth or strength should avoid excessive intake of anti-inflammatory drugs.


Assuntos
Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Treinamento Resistido , Adaptação Fisiológica/efeitos dos fármacos , Adolescente , Adulto , Aspirina/administração & dosagem , Aspirina/efeitos adversos , Feminino , Humanos , Ibuprofeno/administração & dosagem , Ibuprofeno/efeitos adversos , Masculino , Adulto Jovem
18.
J Nutr Health Aging ; 22(4): 541-548, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29582895

RESUMO

OBJECTIVES: Studies show that regular exercise in combination with nutritional support can be effective in managing sarcopenia, which is age-related involuntary loss of skeletal muscle mass and strength. Qualitative investigations of participants' experiences from interventions in this domain are scarce. In this study, we explored older persons' experiences from an intervention designed to prevent sarcopenia, with the aim of capturing the participants' thoughts and opinions. DESIGN: A qualitative study embedded in the multicenter randomized clinical trial The Vitality and Vigor in the Elderly study, VIVE2. Focus group interviews were conducted. Manifest and latent content analyses were performed. PARTICIPANTS: Community dwelling older adults (n=20) 71-86 years of age with minor limitations in mobility. RESULTS: The experiences from the intervention were categorized and interpreted in one overall theme "Feeling more self-confident, cheerful and safe". The theme encompasses the categories psychological effects of participating in the intervention, physical effects of participating in the intervention, the importance of social support and the importance of a tailored set-up. The participants described their motives for participating in the intervention as being based on concerns regarding the negative health effects of continuing a sedentary lifestyle, difficulties of getting started on their own and lack of confidence in accomplishing change on their own. Participants also expressed that one main objective for participating was to lose weight. CONCLUSION: In this study we have captured the experiences of older adults with minor mobility limitations who participated in a lifestyle intervention. The experiences are interpreted in one overall theme "Feeling more self-confident, cheerful and safe". The central understanding of the participants' experiences was that the intervention affected them in several ways, both psychologically and physically, and that supporting factors included the social support, which became a prerequisite for success. A noticeable finding was the discrepancy between the motive of the participants, to lose weight, and the aim of the study, to improve muscle function. The expectation to lose weight seems to reflect what is commonly known as to be healthy. To our knowledge, at least in Sweden, there are no campaigns or public information highlighting the risks of sarcopenia and the complex issue of if, and when weight loss is desirable for older individuals. This finding highlights the importance of providing such information to this target group. The findings in this study provide valuable knowledge for research teams, practitioners and decision makers when designing and setting objectives for health-promoting interventions for older individuals.


Assuntos
Terapia por Exercício/métodos , Promoção da Saúde/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pesquisa Qualitativa
19.
J Nutr Health Aging ; 22(1): 1-7, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29300415

RESUMO

OBJECTIVES: To examine the potential association between serum 25(OH) vitamin D and the performance on the Short Physical Performance Battery (SPPB) including the sub-components; five repeated chair stands test, 4 meters walk test and balance in older mobility-limited community-dwelling men and women. DESIGN: A cross sectional study was performed in American and Swedish subjects who were examined for potential participation in a combined exercise and nutrition intervention trial. Logistic regression analysis and linear regression analyses were performed to evaluate the association for 25(OH)D with the overall score on the SBBP, chair stand, gait speed and balance. PARTICIPANTS: Community-dwelling (mean age 77.6 ± 5.3 years) mobility limited American (n=494) and Swedish (n=116) females (59%) and males. MEASUREMENTS: The SPPB (0-12 points) includes chair stand (s), gait speed (m/s) and a balance test. Mobility limitation i.e., SPPB score ≤ 9 was an inclusion criterion. A blood sample was obtained to measure serum 25(OH)vitamin D concentrations. RESULTS: No clear association of 25(OH)D with SPPB scores was detected either when 25(OH)D was assessed as a continuous variable or when categorized according to serum concentrations of <50, 50-75 or <75 nmol/L. However, when analyzing the relationship between 25(OH)D and seconds to perform the chair stands, a significant quadratic relationship was observed. Thus, at serum levels of 25(OH)D above 74 nmol/L, higher concentrations appeared to be advantageous for the chair stand test, whereas for serum levels below 74 nmol/L this association was not observed. CONCLUSION: This cross- sectional study lacked clear association between serum 25(OH)D and physical performance in mobility limited adults. A potentially interesting observation was that at higher serum levels of 25(OH)D a better performance on the chair stand test was indicated.


Assuntos
Desempenho Físico Funcional , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos Transversais , Suplementos Nutricionais , Exercício Físico , Feminino , Humanos , Vida Independente , Masculino , Limitação da Mobilidade , Estado Nutricional , Equilíbrio Postural , Suécia , Estados Unidos , Vitamina D/sangue , Vitaminas , Velocidade de Caminhada
20.
J Clin Invest ; 101(1): 79-85, 1998 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9421469

RESUMO

We have demonstrated previously that dichloroacetate can attenuate skeletal muscle fatigue by up to 35% in a canine model of peripheral ischemia (Timmons, J.A., S.M. Poucher, D. Constantin-Teodosiu, V. Worrall, I.A. Macdonald, and P.L. Greenhaff. 1996. J. Clin. Invest. 97:879-883). This was thought to be a consequence of dichloroacetate increasing acetyl group availability early during contraction. In this study we characterized the metabolic effects of dichloroacetate in a human model of peripheral muscle ischemia. On two separate occasions (control-saline or dichloroacetate infusion), nine subjects performed 8 min of single-leg knee extension exercise at an intensity aimed at achieving volitional exhaustion in approximately 8 min. During exercise each subject's lower limbs were exposed to 50 mmHg of positive pressure, which reduces blood flow by approximately 20%. Dichloroacetate increased resting muscle pyruvate dehydrogenase complex activation status by threefold and elevated acetylcarnitine concentration by fivefold. After 3 min of exercise, phosphocreatine degradation and lactate accumulation were both reduced by approximately 50% after dichloroacetate pretreatment, when compared with control conditions. However, after 8 min of exercise no differences existed between treatments. Therefore, it would appear that dichloroacetate can delay the accumulation of metabolites which lead to the development of skeletal muscle fatigue during ischemia but does not alter the metabolic profile when a maximal effort is approached.


Assuntos
Ácido Dicloroacético/farmacologia , Exercício Físico/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Acetilcarnitina/metabolismo , Trifosfato de Adenosina/metabolismo , Adulto , Glicemia/metabolismo , Fenômenos Fisiológicos Cardiovasculares , Glicogênio/metabolismo , Humanos , Ácido Láctico/metabolismo , Masculino , Músculo Esquelético/irrigação sanguínea , Fosfocreatina/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Fatores de Tempo
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