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1.
Eur J Nutr ; 62(2): 1041-1050, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36385314

RESUMO

PURPOSE: This study investigated the influence of the different genotypes of ADORA2A (1976 C > T, rs 5751876), alone or pooled with CYP1A2 (163 C > A rs 762551) genotypes, on the ergogenic effects of caffeine (CAF) on various aspects of physical performance in male adolescent athletes. METHODS: Ninety male adolescent athletes (age = 15.5 ± 2 years) were classified according to their genotypes for 1976 C > T ADORA2A (TT homozygous or CADORA2A allele carriers) and 163 C > A CYP1A2 (AA homozygous or CCYP1A2 allele carriers). Participants were further divided in four groups (1-TTADORA2A + AACYP1A2; 2-TTADORA2A + AC/CCCYP1A2; 3-AACYP1A2 + CT/CCADORA2A;4-AC/CCCYP1A2 + CT/CCADORA2A). Using a randomized, crossover, counterbalanced, and double-blind design, participants ingested CAF (6 mg kg-1) or a placebo (PLA, 300 mg of cellulose) one hour before performing a sequence of physical tests: handgrip strength, agility test, countermovement jump (CMJ), Spike Jump (SJ), sit-ups, push-ups, and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). RESULTS: CAF enhanced handgrip strength (CAF: 35.0 ± 9.2 kg force; PLA: 33.5 ± 8.9 kg force; p = 0.050), CMJ height (CAF: 49.6 ± 12.3 cm; PLA: 48.3 ± 13.6 cm; p = 0.013), SJ height (CAF: 54.7 ± 13.3 cm; PLA: 53.1 ± 14.8 cm; p = 0.013), number of sit-ups (CAF: 37 ± 8; PLA: 35 ± 8; p = 0.001), and distance covered on the Yoyo IR1 test (CAF: 991.6 ± 371.0 m; PLA: 896.0 ± 311.0 m; p = 0.001), This CAF-induced improvement on exercise performance was, however, independent of genotypes groups (all p > 0.05). CAF had no effect on agility (CAF: 15.8 ± 1.2 s; PLA: 15.9 ± 1.3 s; p = 0.070) and push-up (CAF: 26.6 ± 12.0; PLA: 25.0 ± 11.0; p = 0.280) tests. CONCLUSION: The acute caffeine intake of 6.0 mg.kg-1 improves several aspects of physical performance, which seems to be independent of ADORA2A genotypes, alone or in combination with CYP1A2 genotypes.


Assuntos
Desempenho Atlético , Cafeína , Humanos , Masculino , Adolescente , Citocromo P-450 CYP1A2 , Força da Mão , Genótipo , Atletas , Método Duplo-Cego , Estudos Cross-Over , Poliésteres
2.
Oral Dis ; 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37811600

RESUMO

OBJECTIVE: To investigate the bidirectional association between oral diseases and cognitive function comprehensively. SUBJECTS AND METHODS: This cross sectional study utilized data from the National Health and Nutrition Examination Survey. Oral diseases include periodontitis, dental caries, and tooth loss (end point of oral disease resulting in tooth extraction). Cognitive function included three domains: memory, processing speed, and executive function. A global cognitive score was then derived from sum of the three cognitive domains. Oral cognition associations were examined using various statistical models: (1) Regress oral disease on cognitive function; (2) Regress cognitive function on oral disease; and (3) Structural equation modelling treating cognition and oral disease as latent variables. RESULTS: There were 2508 participants aged 60+ who had both oral and cognitive information. Associations between various oral disease and global cognitive score were observed (Odds ratio ORcog->periodontitis 0.95, 95% Confidence Interval [0.92, 0.99]; ßcog->caries -0.13, [-0.23, -0.04]; ßcog->tooth loss -0.03 [-0.04, -0.01]; ßtooth loss->cog -0.04 [-0.06, -0.02]; ßcaries->cog -0.03 [-0.06, -0.01]; ßperiodontitis->cog -0.39 [-0.69, -0.10]). Significant correlation was also found between these oral disease and cognitive function using structural equation model (r -0.22, [-0.34, -0.10]). CONCLUSIONS: This study found robust bidirectional associations between oral disease and cognitive function using various modelling approaches among the aging population.

3.
Nature ; 498(7453): 216-9, 2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-23698370

RESUMO

Early-life dietary transitions reflect fundamental aspects of primate evolution and are important determinants of health in contemporary human populations. Weaning is critical to developmental and reproductive rates; early weaning can have detrimental health effects but enables shorter inter-birth intervals, which influences population growth. Uncovering early-life dietary history in fossils is hampered by the absence of prospectively validated biomarkers that are not modified during fossilization. Here we show that large dietary shifts in early life manifest as compositional variations in dental tissues. Teeth from human children and captive macaques, with prospectively recorded diet histories, demonstrate that barium (Ba) distributions accurately reflect dietary transitions from the introduction of mother's milk through the weaning process. We also document dietary transitions in a Middle Palaeolithic juvenile Neanderthal, which shows a pattern of exclusive breastfeeding for seven months, followed by seven months of supplementation. After this point, Ba levels in enamel returned to baseline prenatal levels, indicating an abrupt cessation of breastfeeding at 1.2 years of age. Integration of Ba spatial distributions and histological mapping of tooth formation enables novel studies of the evolution of human life history, dietary ontogeny in wild primates, and human health investigations through accurate reconstructions of breastfeeding history.


Assuntos
Bário/análise , Dieta , Fósseis , Macaca/fisiologia , Homem de Neandertal/fisiologia , Dente/química , Desmame , Adulto , Animais , Aleitamento Materno/história , Cálcio/análise , Pré-Escolar , Dieta/veterinária , Feminino , História Antiga , Humanos , Lactente , Reprodutibilidade dos Testes
4.
PLoS One ; 19(9): e0306983, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39240858

RESUMO

OBJECTIVES: This study aims to systematically review the existing literature and critically appraise the evidence of genome-wide association studies (GWAS) on periodontitis. This study also aims to synthesise the findings of genetic risk variants of periodontitis from included GWAS. METHODS: A systematic search was conducted on PubMed, GWAS Catalog, MEDLINE, GLOBAL HEALTH and EMBASE via Ovid for GWAS on periodontitis. Only studies exploring single-nucleotide polymorphisms(SNPs) associated with periodontitis were eligible for inclusion. The quality of the GWAS was assessed using the Q-genie tool. Information such as study population, ethnicity, genomic data source, phenotypic characteristics(definition of periodontitis), and GWAS methods(quality control, analysis stages) were extracted. SNPs that reached conventional or suggestive GWAS significance level(5e-8 or 5e-06) were extracted and synthesized. RESULTS: A total of 15 good-quality GWAS on periodontitis were included (Q-genie scores ranged from 38-50). There were huge heterogeneities among studies. There were 11 identified risk SNPs (rs242016, rs242014, rs10491972, rs242002, rs2978951, rs2738058, rs4284742, rs729876, rs149133391, rs1537415, rs12461706) at conventional GWAS significant level (p<5x10-8), and 41 at suggestive level (p<5x10-6), but no common SNPs were found between studies. Three SNPs (rs4284742 [G], rs11084095 [A], rs12461706 [T]) from three large studies were from the same gene region-SIGLEC5. CONCLUSION: GWAS of periodontitis showed high heterogeneity of methodology used and provided limited SNPs statistics, making identifying reliable risk SNPs challenging. A clear guidance in dental research with requirement of expectation to make GWAS statistics available to other investigators are needed.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Periodontite , Polimorfismo de Nucleotídeo Único , Humanos , Periodontite/genética
5.
Mar Drugs ; 11(12): 5148-58, 2013 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-24351911

RESUMO

Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Foraminíferos/química , Tíbia/efeitos dos fármacos , Zinco/química , Zinco/farmacologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Densidade Óssea/efeitos dos fármacos , Carbonatos/química , Masculino , Porosidade , Ratos , Ratos Wistar
6.
Br J Sports Med ; 47 Suppl 1: i8-16, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24282213

RESUMO

Despite the limited research on the effects of altitude (or hypoxic) training interventions on team-sport performance, players from all around the world engaged in these sports are now using altitude training more than ever before. In March 2013, an Altitude Training and Team Sports conference was held in Doha, Qatar, to establish a forum of research and practical insights into this rapidly growing field. A round-table meeting in which the panellists engaged in focused discussions concluded this conference. This has resulted in the present position statement, designed to highlight some key issues raised during the debates and to integrate the ideas into a shared conceptual framework. The present signposting document has been developed for use by support teams (coaches, performance scientists, physicians, strength and conditioning staff) and other professionals who have an interest in the practical application of altitude training for team sports. After more than four decades of research, there is still no consensus on the optimal strategies to elicit the best results from altitude training in a team-sport population. However, there are some recommended strategies discussed in this position statement to adopt for improving the acclimatisation process when training/competing at altitude and for potentially enhancing sea-level performance. It is our hope that this information will be intriguing, balanced and, more importantly, stimulating to the point that it promotes constructive discussion and serves as a guide for future research aimed at advancing the bourgeoning body of knowledge in the area of altitude training for team sports.


Assuntos
Aclimatação/fisiologia , Altitude , Desempenho Atlético/fisiologia , Pressão Atmosférica , Comportamento Competitivo/fisiologia , Exercício Físico/fisiologia , Tolerância ao Exercício/fisiologia , Previsões , Processos Grupais , Humanos , Hipóxia/fisiopatologia , Prática Profissional/tendências , Sono/fisiologia , Medicina Esportiva/métodos , Medicina Esportiva/tendências
7.
Anal Methods ; 15(6): 797-806, 2023 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-36722471

RESUMO

Mineralised tissue such as teeth can serve as a retrospective, chronological bioindicator of past exposure to toxic metals. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) can be used to determine the presence and spatial distribution of toxic metals in teeth, giving a record of when an exposure occurred. Concentrations of these metals are often determined by a one-point calibration against NIST glass using an equation that requires an internal standard factor that accounts for differences in ablation behaviour between the glass and the tooth. However, an ideal external calibration would contain multiple matrix-matched standards to obtain a calibration curve. Here, we investigated optimal procedures for preparing synthetic hydroxyapatite (HA) doped with elements of interest as a calibration material. The materials were examined for homogeneity of metal incorporation, matrix-matched ablation characteristics, linearity, and limits of detection. A homogenised and pelleted HA was the most suitable material, providing improved ablation characteristics over previous HA materials and NIST glass for the analysis of teeth. An ablation yield of 1.1 showed its suitability to analyse teeth, the metals were homogeneously incorporated, and it produced excellent linearity with limits of detection ranging from 0.1-2 µg kg-1 for magnesium, aluminium, nickel, copper, zinc, cadmium, barium and lead. A juvenile incisor from a remote indigenous community in Australia and an adult molar from Sri Lanka were assessed for toxic metal exposure. The molar showed evidence of exposure to cadmium and lead. The synthetic HA material was straightforward to prepare, and will improve confidence in the analysis of teeth and other biomineralised material when assessing toxic metal exposure.


Assuntos
Cádmio , Terapia a Laser , Cádmio/análise , Estudos Retrospectivos , Espectrometria de Massas/métodos , Cobre/análise , Metais
8.
Hum Mol Genet ; 19(4): 584-96, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19934113

RESUMO

Human acute intermittent porphyria (AIP), the most common acute hepatic porphyria, is an autosomal dominant inborn error of heme biosynthesis due to the half-normal activity of hydroxymethylbilane synthase (HMB-synthase). Here, we describe the first naturally occurring animal model of AIP in four unrelated cat lines who presented phenotypically as congenital erythropoietic porphyria (CEP). Affected cats had erythrodontia, brownish urine, fluorescent bones, and markedly elevated urinary uroporphyrin (URO) and coproporphyrin (COPRO) consistent with CEP. However, their uroporphyrinogen-III-synthase (URO-synthase) activities (deficient in CEP) were normal. Notably, affected cats had half-normal HMB-synthase activities and elevated urinary 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), the deficient enzyme and accumulated metabolites in human AIP. Sequencing the feline HMB-synthase gene revealed different mutations in each line: a duplication (c.189dupT), an in-frame 3 bp deletion (c.842_844delGAG) identical to that causing human AIP and two missense mutations, c.250G>A (p.A84T) and c.445C>T (p.R149W). Prokaryotic expression of mutations c.842_844delGAG and c.445C>T resulted in mutant enzymes with <1% wild-type activity, whereas c.250G>A expressed a stable enzyme with approximately 35% of wild-type activity. The discolored teeth from the affected cats contained markedly elevated URO I and III, accounting for the CEP-like phenocopy. In three lines, the phenotype was an autosomal dominant trait, while affected cats with the c.250G>A (p.A84T) mutation were homozygous, a unique recessive form of AIP. These animal models may permit further investigation of the pathogenesis of the acute, life-threatening neurological attacks in human AIP and the evaluation of therapeutic strategies. GenBank Accession Numbers: GQ850461-GQ850464.


Assuntos
Doenças do Gato/enzimologia , Gatos/genética , Modelos Animais de Doenças , Hidroximetilbilano Sintase/genética , Mutação , Porfiria Aguda Intermitente/enzimologia , Porfiria Eritropoética/enzimologia , Animais , Osso e Ossos/metabolismo , Doenças do Gato/genética , Doenças do Gato/metabolismo , Gatos/metabolismo , Coproporfirinas/urina , Feminino , Humanos , Hidroximetilbilano Sintase/química , Hidroximetilbilano Sintase/metabolismo , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Porfiria Aguda Intermitente/genética , Porfiria Aguda Intermitente/metabolismo , Porfiria Eritropoética/genética , Porfiria Eritropoética/metabolismo , Porfirinas/metabolismo , Dente/metabolismo , Uroporfirinas/urina
9.
Sci Rep ; 12(1): 16762, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36202885

RESUMO

The aim of this study was to investigate the physiological effects of compression tights on blood flow following exercise and to assess if the placebo effect is responsible for any acute performance or psychological benefits. Twenty-two resistance-trained participants completed a lower-body resistance exercise session followed by a 4 h recovery period. Participants were assigned a post-exercise recovery intervention of either compression tights applied for 4 h (COMP), placebo tablet consumed every hour for 4 h (PLA) or control (CON). Physiological (markers of venous return, muscle blood flow, blood metabolites, thigh girth), performance (countermovement jump, isometric mid-thigh pull), and psychological measures (perceived muscle soreness, total quality of recovery) were collected pre-exercise, immediately post-exercise, at 30 (markers of venous return and muscle blood flow) and 60 min (blood metabolites, thigh girth and psychological measures) intervals during 4 h of recovery, and at 4 h, 24 h and 48 h post-exercise. No significant (P > 0.05) differences were observed between interventions. However, effect size analysis revealed COMP enhanced markers of venous return, muscle blood flow, recovery of performance measures, psychological measures and reduced thigh girth compared to PLA and CON. There were no group differences in blood metabolites. These findings suggest compression tights worn after resistance exercise enhance blood flow and indices of exercise recovery, and that these benefits were not due to a placebo effect.


Assuntos
Mialgia , Efeito Placebo , Exercício Físico/fisiologia , Humanos , Músculo Esquelético/fisiologia , Poliésteres , Coxa da Perna
10.
Mol Med ; 16(9-10): 381-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20485863

RESUMO

The first feline model of human congenital erythropoietic porphyria (CEP) due to deficient uroporphyrinogen III synthase (URO-synthase) activity was identified by its characteristic clinical phenotype, and confirmed by biochemical and molecular genetic studies. The proband, an adult domestic shorthair cat, had dark-red urine and brownish discolored teeth with red fluorescence under ultraviolet light. Biochemical studies demonstrated markedly increased uroporphyrinogen I in urine and plasma (2,650- and 10,700-fold greater than wild type, respectively), whereas urinary 5-aminolevulinic acid and porphobilinogen were lower than normal. Erythrocytic URO-synthase activity was <1% of mean wild-type activity, confirming the diagnosis and distinguishing it from feline phenocopies having acute intermittent porphyria. Sequencing of the affected cat's UROS gene revealed two missense mutations, c.140C>T (p.S47F) in exon 3 and c.331G>A (p.G111S) in exon 6, both of which were homozygous, presumably owing to parental consanguinity. Neither was present in 100 normal cat alleles. Prokaryotic expression and thermostability studies of the purified monomeric wild-type, p.S47F, p.G111S, and p.S47F/G111S enzymes showed that the p.S47F enzyme had 100% of wild-type specific activity but ~50% decreased thermostability, whereas the p.G111S and p.S47F/G111S enzymes had about 60% and 20% of wild-type specific activity, respectively, and both were markedly thermolabile. Molecular modeling results indicated that the less active/less stable p.G111S enzyme was further functionally impaired by a structural interaction induced by the presence of the S47F substitution. Thus, the synergistic interaction of two rare amino acid substitutions in the URO-synthase polypeptide caused the feline model of human CEP.


Assuntos
Doenças do Gato/enzimologia , Doenças do Gato/genética , Homozigoto , Mutação de Sentido Incorreto/genética , Porfiria Eritropoética/veterinária , Porfirinas/metabolismo , Uroporfirinogênio III Sintetase/genética , Animais , Doenças do Gato/sangue , Doenças do Gato/urina , Gatos , Eritrócitos/metabolismo , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Porfiria Eritropoética/sangue , Porfiria Eritropoética/enzimologia , Porfiria Eritropoética/urina , Porfirinas/sangue , Porfirinas/urina , Uroporfirinogênio III Sintetase/química , Uroporfirinogênio III Sintetase/metabolismo
11.
Sports Med ; 49(1): 17-30, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30298476

RESUMO

This paper aims to critically evaluate and thoroughly discuss the evidence on the topic of caffeine supplementation when performing resistance exercise, as well as provide practical guidelines for the ingestion of caffeine prior to resistance exercise. Based on the current evidence, it seems that caffeine increases both maximal strength and muscular endurance. Furthermore, power appears to be enhanced with caffeine supplementation, although this effect might, to a certain extent, be caffeine dose- and external load-dependent. A reduction in rating of perceived exertion (RPE) might contribute to the performance-enhancing effects of caffeine supplementation as some studies have observed decreases in RPE coupled with increases in performance following caffeine ingestion. However, the same does not seem to be the case for pain perception as there is evidence showing acute increases in resistance exercise performance without any significant effects of caffeine ingestion on pain perception. Some studies have reported that caffeine ingestion did not affect exercise-induced muscle damage, but that it might reduce perceived resistance exercise-induced delayed-onset muscle soreness; however, this needs to be explored further. There is some evidence that caffeine ingestion, compared with a placebo, may lead to greater increases in the production of testosterone and cortisol following resistance exercise. However, given that the acute changes in hormone levels seem to be weakly correlated with hallmark adaptations to resistance exercise, such as hypertrophy and increased muscular strength, these findings are likely of questionable practical significance. Although not without contrasting findings, the available evidence suggests that caffeine ingestion can lead to acute increases in blood pressure (primarily systolic), and thus caution is needed regarding caffeine supplementation among individuals with high blood pressure. In the vast majority of studies, caffeine was administered in capsule or powder forms, and therefore the effects of alternative forms of caffeine, such as chewing gums or mouth rinses, on resistance exercise performance remain unclear. The emerging evidence suggests that coffee might be at least equally ergogenic as caffeine alone when the caffeine dose is matched. Doses in the range of 3-9 mg·kg-1 seem to be adequate for eliciting an ergogenic effect when administered 60 min pre-exercise. In general, caffeine seems to be safe when taken in the recommended doses. However, at doses as high as 9 mg·kg-1 or higher, side effects such as insomnia might be more pronounced. It remains unclear whether habituation reduces the ergogenic benefits of caffeine on resistance exercise as no evidence exists for this type of exercise. Caution is needed when extrapolating these conclusions to females as the vast majority of studies involved only male participants.


Assuntos
Desempenho Atlético , Cafeína/farmacologia , Substâncias para Melhoria do Desempenho/farmacologia , Treinamento Resistido , Pressão Sanguínea , Cafeína/administração & dosagem , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Humanos , Força Muscular , Mialgia , Percepção da Dor , Substâncias para Melhoria do Desempenho/administração & dosagem , Resistência Física
12.
Sports Med ; 38(3): 253-63, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18278985

RESUMO

Sport science can be thought of as a scientific process used to guide the practice of sport with the ultimate aim of improving sporting performance. However, despite this goal, the general consensus is that the translation of sport-science research to practice is poor. Furthermore, researchers have been criticised for failing to study problems relevant to practitioners and for disseminating findings that are difficult to implement within a practical setting. This paper proposes that the situation may be improved by the adoption of a model that guides the direction of research required to build our evidence base about how to improve performance. Central to the Applied Research Model for the Sport Sciences (ARMSS) described in this report is the idea that only research leading to practices that can and will be adopted can improve sporting performance. The eight stages of the proposed model are (i) defining the problem; (ii) descriptive research; (iii) predictors of performance; (iv) experimental testing of predictors; (v) determinants of key performance predictors; (vi) efficacy studies; (vii) examination of barriers to uptake; and (viii) implementation studies in a real sporting setting. It is suggested that, from the very inception, researchers need to consider how their research findings might ultimately be adapted to the intended population, in the actual sporting setting, delivered by persons with diverse training and skills, and using the available resources. It is further argued in the model that a greater understanding of the literature and more mechanistic studies are essential to inform subsequent research conducted in real sporting settings. The proposed ARMSS model therefore calls for a fundamental change in the way in which many sport scientists think about the research process. While there is no guarantee that application of this proposed research model will improve actual sports performance, anecdotal evidence suggests that sport-science research is not currently informing sport-science practice as we would hope and that sport-science researchers need to consider a new approach.


Assuntos
Pesquisa Biomédica/métodos , Modelos Teóricos , Medicina Esportiva/métodos , Esportes , Humanos
13.
Sci Rep ; 5: 11878, 2015 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-26234773

RESUMO

The benefits of using silk fibroin, a major protein in silk, are widely established in many biomedical applications including tissue regeneration, bioactive coating and in vitro tissue models. The properties of silk such as biocompatibility and controlled degradation are utilized in this study to formulate for the first time as carriers for pulmonary drug delivery. Silk fibroin particles are spray dried or spray-freeze-dried to enable the delivery to the airways via dry powder inhalers. The addition of excipients such as mannitol is optimized for both the stabilization of protein during the spray-freezing process as well as for efficient dispersion using an in vitro aerosolisation impactor. Cisplatin is incorporated into the silk-based formulations with or without cross-linking, which show different release profiles. The particles show high aerosolisation performance through the measurement of in vitro lung deposition, which is at the level of commercially available dry powder inhalers. The silk-based particles are shown to be cytocompatible with A549 human lung epithelial cell line. The cytotoxicity of cisplatin is demonstrated to be enhanced when delivered using the cross-linked silk-based particles. These novel inhalable silk-based drug carriers have the potential to be used as anti-cancer drug delivery systems targeted for the lungs.


Assuntos
Antineoplásicos Alquilantes/química , Materiais Biocompatíveis/química , Cisplatino/química , Portadores de Fármacos/química , Fibroínas/química , Animais , Antineoplásicos Alquilantes/toxicidade , Bombyx/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/toxicidade , Dano ao DNA/efeitos dos fármacos , Inaladores de Pó Seco/métodos , Fibroínas/isolamento & purificação , Liofilização , Humanos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula
14.
Appl Biochem Biotechnol ; 101(1): 77-91, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12008868

RESUMO

The adsorption and activity of a total cellulase (Trichoderma reesei) was measured and compared on undyed and dyed cotton fabrics. Recovery of enzymes from the reaction mixture and by desorption from the cotton substrate was evaluated. About 80% of the initial protein could be recovered. The removal of released products (soluble reducing sugars and dyes) from the treatment liquor and subsequent concentration of cellulase proteins was performed using an ultrafiltration membrane. Strong protein-dye interactions made it impossible to separate efficiently the dyes from the enzyme-containing treatment liquors. The use of surfactants did not enhance cellulase desorption from cotton fabric. Although anionic surfactants have a deactivating effect on cellulases, this effect seems to be reversible, since after ultrafiltration the cellulase activity was similar to that of enzymes desorbed with buffer only. Humicola insolens cellulases were shown to be much more sensitive to anionic surfactant than T. reesei cellulases. The use of cellulases that bind reversibly to cellulose is suggested for achieving more efficient cellulase recycling and for reducing backstaining by dye-cellulase complexes.


Assuntos
Celulase/química , Celulase/metabolismo , Fibra de Algodão , Adsorção , Antraquinonas/química , Ascomicetos/enzimologia , Carboximetilcelulose Sódica/análise , Celulase/antagonistas & inibidores , Celulase/efeitos dos fármacos , Celulose/análise , Celulose/metabolismo , Corantes/química , Glucose/análise , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Indóis/química , Indóis/metabolismo , Especificidade por Substrato , Tensoativos/química , Têxteis , Trichoderma/enzimologia , Ultrafiltração
16.
Vet J ; 198(3): 720-2, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24239138

RESUMO

Erythrodontia is the hallmark of human congenital erythropoietic porphyria (CEP), but is also a major phenotypic feature of acute intermittent porphyria (AIP) in cats. In this study, detailed biochemical and molecular analyses were performed on two unrelated cats with autosomal dominant AIP that presented with erythrodontia, yellow-brown urine and mild changes in erythrocytes. The cats had elevated concentrations of urinary 5-aminolevulinic acid and porphobilinogen, and half normal erythrocytic hydroxymethylbilane synthase (HMBS) activity. Two novel HMBS mutations were detected; one cat had a deletion (c.107_110delACAG) and one cat had a splicing alteration (c.826-1G>A), both leading to premature stop codons and truncated proteins (p.D36Vfs 6 and p.L276Efs 6, respectively). These studies highlight the importance of appropriate biochemical and molecular genetic analyses for the accurate diagnoses of porphyrias in cats and extend the molecular genetic heterogeneity of feline AIP. Thus, although erythrodontia is a classic sign of congenital erythropoietic porphyria in human beings, cats with erythrodontia may have acute intermittent porphyria, a hepatic porphyria.


Assuntos
Doenças do Gato/diagnóstico , Hidroximetilbilano Sintase/genética , Porfiria Aguda Intermitente/veterinária , Descoloração de Dente/veterinária , Animais , Gatos , Feminino , Florida , Hidroximetilbilano Sintase/metabolismo , Dados de Sequência Molecular , Mutação , Porfiria Aguda Intermitente/diagnóstico , Análise de Sequência de DNA/veterinária , Tennessee , Descoloração de Dente/diagnóstico
17.
Sports Med ; 40(12): 995-1017, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21058748

RESUMO

A well designed diet is the foundation upon which optimal training and performance can be developed. However, as long as competitive sports have existed, athletes have attempted to improve their performance by ingesting a variety of substances. This practice has given rise to a multi-billion-dollar industry that aggressively markets its products as performance enhancing, often without objective, scientific evidence to support such claims. While a number of excellent reviews have evaluated the performance-enhancing effects of most dietary supplements, less attention has been paid to the performance-enhancing claims of dietary supplements in the context of team-sport performance. Dietary supplements that enhance some types of athletic performance may not necessarily enhance team-sport performance (and vice versa). Thus, the first aim of this review is to critically evaluate the ergogenic value of the most common dietary supplements used by team-sport athletes. The term dietary supplements will be used in this review and is defined as any product taken by the mouth, in addition to common foods, that has been proposed to have a performance-enhancing effect; this review will only discuss substances that are not currently banned by the World Anti-Doping Agency. Evidence is emerging to support the performance-enhancing claims of some, but not all, dietary supplements that have been proposed to improve team-sport-related performance. For example, there is good evidence that caffeine can improve single-sprint performance, while caffeine, creatine and sodium bicarbonate ingestion have all been demonstrated to improve multiple-sprint performance. The evidence is not so strong for the performance-enhancing benefits of ß-alanine or colostrum. Current evidence does not support the ingestion of ribose, branched-chain amino acids or ß-hydroxy-ß-methylbutyrate, especially in well trained athletes. More research on the performance-enhancing effects of the dietary supplements highlighted in this review needs to be conducted using team-sport athletes and using team-sport-relevant testing (e.g. single- and multiple-sprint performance). It should also be considered that there is no guarantee that dietary supplements that improve isolated performance (i.e. single-sprint or jump performance) will remain effective in the context of a team-sport match. Thus, more research is also required to investigate the effects of dietary supplements on simulated or actual team-sport performance. A second aim of this review was to investigate any health issues associated with the ingestion of the more commonly promoted dietary supplements. While most of the supplements described in the review appear safe when using the recommended dose, the effects of higher doses (as often taken by athletes) on indices of health remain unknown, and further research is warranted. Finally, anecdotal reports suggest that team-sport athletes often ingest more than one dietary supplement and very little is known about the potential adverse effects of ingesting multiple supplements. Supplements that have been demonstrated to be safe and efficacious when ingested on their own may have adverse effects when combined with other supplements. More research is required to investigate the effects of ingesting multiple supplements (both on performance and health).


Assuntos
Desempenho Atlético , Suplementos Nutricionais , Suplementos Nutricionais/efeitos adversos , Suplementos Nutricionais/classificação , Suplementos Nutricionais/estatística & dados numéricos , Feminino , Humanos , Masculino
18.
Int J Sports Physiol Perform ; 1(2): 161-8, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19114748

RESUMO

As sports scientists, we claim to make a significant contribution to the body of knowledge that influences athletic practice and performance. Is this the reality? At the inaugural congress of the Australian Association for Exercise and Sports Science, a panel of well-credentialed academic experts with experience in the applied environment debated the question, Does sports-science research influence practice? The first task was to define "sports-science research," and it was generally agreed that it is concerned with providing evidence that improves sports performance. When practices are equally effective, sports scientists also have a role in identifying practices that are safer, more time efficient, and more enjoyable. There were varying views on the need for sports-science research to be immediately relevant to coaches or athletes. Most agreed on the importance of communicating the results of sports-science research, not only to the academic community but also to coaches and athletes, and the need to encourage both short- and long-term research. The panelists then listed examples of sports-science research that they believe have influenced practice, as well as strategies to ensure that sports-science research better influences practice.


Assuntos
Pesquisa Biomédica , Medicina Baseada em Evidências , Medicina Esportiva , Esportes/fisiologia , Humanos , Análise e Desempenho de Tarefas
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