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1.
Sci Total Environ ; 691: 572-583, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325857

RESUMO

Since the 1956 completion of nuclear testing at the Montebello Islands, Western Australia, this remote uninhabited island group has been relatively undisturbed (no major remediations) and currently functions as high-value marine and terrestrial habitat within the Montebello/Barrow Islands Marine Conservation Reserves. The former weapons testing sites, therefore, provide a unique opportunity for assessing the fate and behaviour of Anthropocene radionuclides subjected to natural processes across a range of shallow-marine to island-terrestrial ecological units (ecotopes). We collected soil, sediment and biota samples and analysed their radionuclide content using gamma and alpha spectrometry, photostimulated luminescence autoradiography and accelerator mass spectrometry. We found the activity levels of the fission and neutron-activation products have decreased by ~hundred-fold near the ground zero locations. However, Pu concentrations remain elevated, some of which are high relative to most other Australian and international sites (up to 25,050 Bq kg-1 of 239+240+241Pu). Across ecotopes, Pu ranked from highest to lowest in the following order: island soils > dunes > foredunes > marine sediments > and beach intertidal zone. Low values of Pu and other radionuclides were detected in all local wildlife tested including endangered species. Activity concentrations ranked (highest to lowest) terrestrial arthropods > terrestrial mammal and reptile bones > algae > oyster flesh > whole crab > sea turtle bone > stingray and teleost fish livers > sea cucumber flesh > sea turtle skin > teleost fish muscle. The three detonations (one from within a ship and two from 30 m towers) resulted in differing contaminant forms, with the ship detonation producing the highest activity concentrations and finer more inhalable particulate forms. The three sites are distinct in their 240/239Pu and 241/239Pu atom ratios, including the Pu transported by natural process or within migratory living organisms.


Assuntos
Plutônio/análise , Monitoramento de Radiação , Cinza Radioativa/análise , Poluentes Radioativos/análise , Armas Nucleares , Austrália Ocidental
2.
Osteoporos Int ; 28(2): 609-619, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27699440

RESUMO

We investigated the impact of food group intake during adolescence on bone structure and strength during adulthood. In females, we found a beneficial effect of adolescent milk and alternatives and fruit and vegetable intake on adult radius shaft and distal tibia bone structure, respectively. No association was observed in males. INTRODUCTION: The purpose of this study was to investigate whether adolescents with high intake of milk and alternatives (M&A) or fruit and vegetables (F&V) had better adult bone structure and strength compared to those with low intake levels. METHODS: We analyzed data from 47 males and 69 females enrolled in the Pediatric Bone Mineral Accrual Study (PBMAS 1991-2011), who had one peripheral quantitative computed tomography scan at age 29 ± 2 years. We measured radius and tibia shaft total area (ToA), cortical area (CoA), cortical content (CoC), cortical density, bone strength (SSIp), and muscle area, as well as distal radius and tibia ToA, total density, trabecular area, trabecular content, trabecular density, and bone strength (BSIc). Sequential 24-h recalls were used to assess M&A and F&V intake; participants were grouped for their mean intake during adolescence (low = bottom quartile, moderate = middle quartiles, high = top quartile) and were compared using multivariate analysis of covariance while adjusting for adult height, muscle area, physical activity, energy and calcium intake and adolescent energy intake, and physical activity. RESULTS: Females with high M&A intake compared to low M&A intake group (mean 3.8 vs. 1.3 servings/day, respectively) had greater adult ToA (14 %, p < 0.05), CoA (15 %, p < 0.01), and CoC (16 %, p < 0.01) at radius shaft. Females with moderate F&V intake compared to low F&V intake group (mean 3.7 vs. 2.1 servings/day, respectively) had greater adult ToA (8.5 %, p < 0.05) at distal tibia. CONCLUSION: Higher intake of M&A or F&V during adolescence had a long-term beneficial effect on bone structure in females, an association not observed in males.


Assuntos
Fenômenos Fisiológicos da Nutrição do Adolescente/fisiologia , Densidade Óssea/fisiologia , Comportamento Alimentar/fisiologia , Frutas , Leite , Verduras , Adolescente , Animais , Antropometria/métodos , Pré-Escolar , Dieta , Exercício Físico/fisiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Rádio (Anatomia)/diagnóstico por imagem , Rádio (Anatomia)/fisiologia , Caracteres Sexuais , Tíbia/diagnóstico por imagem , Tíbia/fisiologia , Tomografia Computadorizada por Raios X/métodos
3.
Biochem Pharmacol ; 121: 78-96, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27659810

RESUMO

The need to protect human spermatozoa from oxidative stress during assisted reproductive technology, has prompted a detailed analysis of the impacts of phenolic compounds on the functional integrity of these cells. Investigation of 16 individual compounds revealed a surprising variety of negative effects including: (i) a loss of mitochondrial membrane potential (Δψm) via mechanisms that were not related to opening of the permeability transition pore but associated with a reduction in thiol expression, (ii) a decline in intracellular reduced glutathione, (iii) the stimulation of pro-oxidant activity including the induction of ROS generation from mitochondrial and non-mitochondrial sources, (iv) stimulation of lipid peroxidation, (v) the generation of oxidative DNA damage, and (vi) impaired sperm motility. For most of the polyphenolic compounds examined, the loss of motility was gradual and highly correlated with the induction of lipid peroxidation (r=0.889). The exception was gossypol, which induced a rapid loss of motility due to its inherent alkylating activity; one consequence of which was a marked reduction in carboxymethyl lysine expression on the sperm tail; a post-translational modification that is known to play a key role in the regulation of sperm movement. The only polyphenols that did not appear to have adverse effects on spermatozoa were resveratrol, genistein and THP at doses below 100µM. These compounds could, therefore, have some therapeutic potential in a clinical setting.


Assuntos
Dano ao DNA , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/efeitos adversos , Espermatozoides/efeitos dos fármacos , Relação Dose-Resposta a Droga , Citometria de Fluxo , Humanos , Processamento de Imagem Assistida por Computador , Técnicas In Vitro , Masculino , Potencial da Membrana Mitocondrial/genética , Estresse Oxidativo/genética , Polifenóis/administração & dosagem , Polifenóis/química , Técnicas de Reprodução Assistida , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Espermatozoides/patologia
4.
Eur J Clin Nutr ; 70(10): 1099-1105, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27026430

RESUMO

Food fortification can deliver essential micronutrients to large population segments without modifications in consumption pattern, suggesting that fortified foods may be formulated for populations at risk for fragility fractures. This scoping review determined the extent to which randomized controlled studies have been carried out to test the impact of fortified foods on bone outcomes, searching PubMed for all studies using the terms 'fortified AND bone', and 'fortification AND bone'. Studies were restricted to English language, published between 1996 and June 2015. From 360 articles, 24 studies met the following criteria: human study in adults ⩾18 years (excluding pregnancy or lactation); original study of a fortified food over time, with specific bone outcomes measured pre- and post intervention. Six studies involved adults <50 years; 18 involved adults ⩾50 years. Singly or in combination, 17 studies included calcium and 16 included vitamin D. There were 1 or 2 studies involving either vitamin K, magnesium, iron, zinc, B-vitamins, inulin or isoflavones. For adults <50 years, the four studies involving calcium or vitamin D showed a beneficial effect on bone remodeling. For adults ⩾50 years, n=14 provided calcium and/or vitamin D, and there was a significant bone turnover reduction. No consistent effects were reported in studies in which addition of vitamin K, folic acid or isoflavone was assessed. Results from this scoping review indicate that up to now most studies of fortification with bone health have evaluated calcium and/or vitamin D and that these nutrients show beneficial effects on bone remodeling.


Assuntos
Osso e Ossos/efeitos dos fármacos , Cálcio da Dieta/administração & dosagem , Alimentos Fortificados , Vitamina D/administração & dosagem , Adulto , Cálcio da Dieta/farmacologia , Ensaios Clínicos como Assunto , Feminino , Fraturas Ósseas/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , Vitamina D/farmacologia
5.
Andrology ; 4(2): 345-60, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26825875

RESUMO

This study reports, for the first time, the significant (p ≤ 0.01) accumulation of homocysteine residues in low density, defective sperm suspensions isolated from patients attending an infertility clinic. This overabundance of homocysteine was not related to a deficiency in folate availability but may have been a reflection of the oxidative stress that characterizes such defective sperm populations. Direct addition of the homocysteine cyclic congener, homocysteine thiolactone, to human spermatozoa resulted in the rapid induction of mitochondrial reactive oxygen species (ROS) generation (p < 0.001), the stimulation of lipid peroxidation (p < 0.01), the promotion of tyrosine phosphorylation (p < 0.001), and the suppression of sperm motility (p < 0.001) in the absence of any significant impact on DNA integrity. The parent homocysteine molecule was less active and took 24 h to stimulate mitochondrial ROS production possibly because of the need to convert this compound to the corresponding thiolactone before it could exert a measureable biological effect. Thiolactone was also effective in suppressing the carboxymethylation of key proteins in the sperm tail, which are thought to be involved in the regulation of sperm movement. The major enzyme responsible for removing thiolactone from proteins, paraoxonase (PON-1), was shown to be a major target for alkylation by lipid aldehydes, such as 4-hydroxynonenal, generated as a consequence of oxidative stress. Exposure of human spermatozoa to such aldehydes resulted in a dose-dependent accumulation of homocysteine in spermatozoa (p < 0.03). These results suggest that one of the consequences of oxidative stress in mammalian spermatozoa is the inhibition of PON-1, which then enhances the availability of homocysteine thiolactone to interact with the epsilon-amino group of lysine residues on sperm proteins, triggering a raft of significant biological changes in these cells that ultimately compromise sperm function.


Assuntos
Arildialquilfosfatase/metabolismo , Homocisteína/análogos & derivados , Homocisteína/metabolismo , Espermatozoides/metabolismo , Humanos , Infertilidade Masculina/etiologia , Masculino , Motilidade dos Espermatozoides
6.
Proc Biol Sci ; 283(1822)2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26763709

RESUMO

The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle (Caretta caretta) as a model, we used quantitative PCR to characterise variation in the expression response of heat-shock genes (hsp60, hsp70 and hsp90; molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat-shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments.


Assuntos
Adaptação Biológica , Embrião não Mamífero/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico , Tartarugas/embriologia , Animais , Mudança Climática , Geografia , Proteínas de Choque Térmico/metabolismo , Modelos Biológicos , Tartarugas/fisiologia
7.
Br J Cancer ; 113(1): 20-9, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26035702

RESUMO

BACKGROUND: This analysis compared the quality-adjusted survival and clinical outcomes of albumin-bound paclitaxel+carboplatin (nab-PC) vs solvent-based paclitaxel+carboplatin (sb-PC) as first-line therapy in advanced non-small-cell lung cancer (NSCLC) in older patients. METHODS: Using age-based subgroup data from a randomised Phase-3 clinical trial, nab-PC and sb-PC were compared with respect to overall response rate (ORR), overall survival (OS), progression-free survival (PFS), quality of life (QoL), safety/toxicity, and quality-adjusted time without symptoms or toxicity (Q-TWiST) with ages ⩾60 and ⩾70 years as cut points. RESULTS: Among patients aged ⩾60 years (N=546), nab-PC (N=265) significantly increased ORR and prolonged OS, despite a non-significant improvement in PFS, vs sb-PC (N=281). Nab-PC improved QoL and was associated with less neuropathy, arthralgia, and myalgia but resulted in more anaemia and thrombocytopenia. Nab-PC yielded significant Q-TWiST benefits (11.1 vs 9.8 months; 95% CI of gain: 0.2-2.6), with a relative Q-TWiST gain of 10.8% (ranging from 6.4% to 15.1% in threshold analysis). In the ⩾70 years age group, nab-PC showed similar, but non-significant, ORR, PFS, and Q-TWiST benefits and significantly improved OS and QoL. CONCLUSION: Nab-PC as first-line therapy in older patients with advanced NSCLC increased ORR, OS, and QoL and resulted in quality-adjusted survival gains compared with standard sb-PC.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/uso terapêutico , Análise de Sobrevida , Idoso , Idoso de 80 Anos ou mais , Paclitaxel Ligado a Albumina , Albuminas/efeitos adversos , Albuminas/uso terapêutico , Antineoplásicos Fitogênicos/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Feminino , Humanos , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Paclitaxel/efeitos adversos , Qualidade de Vida , Resultado do Tratamento
8.
J Therm Biol ; 47: 42-50, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25526653

RESUMO

The survival and viability of sea turtle embryos is dependent upon favourable nest temperatures throughout the incubation period. Consequently, future generations of sea turtles may be at risk from increasing nest temperatures due to climate change, but little is known about how embryos respond to heat stress. Heat shock genes are likely to be important in this process because they code for proteins that prevent cellular damage in response to environmental stressors. This study provides the first evidence of an expression response in the heat shock genes of embryos of loggerhead sea turtles (Caretta caretta) exposed to realistic and near-lethal temperatures (34°C and 36°C) for 1 or 3 hours. We investigated changes in Heat shock protein 60 (Hsp60), Hsp70, and Hsp90 mRNA in heart (n=24) and brain tissue (n=29) in response to heat stress. Under the most extreme treatment (36°C, 3h), Hsp70 increased mRNA expression by a factor of 38.8 in heart tissue and 15.7 in brain tissue, while Hsp90 mRNA expression increased by a factor of 98.3 in heart tissue and 14.7 in brain tissue. Hence, both Hsp70 and Hsp90 are useful biomarkers for assessing heat stress in the late-stage embryos of sea turtles. The method we developed can be used as a platform for future studies on variation in the thermotolerance response from the clutch to population scale, and can help us anticipate the resilience of reptile embryos to extreme heating events.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Resposta ao Choque Térmico , Tartarugas/embriologia , Tartarugas/metabolismo , Animais , Biomarcadores , Encéfalo/metabolismo , Chaperonina 60/genética , Chaperonina 60/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP90/genética , Miocárdio/metabolismo , RNA Mensageiro/metabolismo , Tartarugas/genética
9.
Hum Reprod ; 29(10): 2136-47, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25141857

RESUMO

STUDY QUESTION: What are the mechanisms by which the preparation of spermatozoa on discontinuous density gradients leads to an increase in oxidative DNA damage? SUMMARY ANSWER: The colloidal silicon solutions that are commonly used to prepare human spermatozoa for assisted reproduction technology (ART) purposes contain metals in concentrations that promote free radical-mediated DNA damage. WHAT IS KNOWN ALREADY: Sporadic reports have already appeared indicating that the use of colloidal silicon-based discontinuous density gradients for sperm preparation is occasionally associated with the induction of oxidative DNA damage. The cause of this damage is however unknown. STUDY DESIGN, SIZE, DURATION: This study comprised a series of experiments designed to: (i) confirm the induction of oxidative DNA damage in spermatozoa prepared on commercially available colloidal silicon gradients, (ii) compare the levels of damage observed with alterative sperm preparation techniques including an electrophoretic approach and (iii) determine the cause of the oxidative DNA damage and develop strategies for its prevention. The semen samples employed for this analysis involved a cohort of >50 unselected donors and at least three independent samples were used for each component of the analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The setting was a University biomedical science laboratory. The major techniques employed were: (i) flow cytometry to study reactive oxygen species generation, lipid peroxidation and DNA damage, (ii) computer-aided sperm analysis to measure sperm movement and (iii) inductively coupled mass spectrometry to determine the elemental composition of sperm preparation media. MAIN RESULTS AND THE ROLE OF CHANCE: Oxidative DNA damage is induced in spermatozoa prepared on PureSperm(®) discontinuous colloidal silicon gradients (P < 0.001 versus repeated centrifugation) because this medium contains metals, particularly Fe, Al and Cu, which are known to promote free radical generation in the immediate vicinity of DNA. This damage can be significantly accentuated by reducing agents, such as ascorbate (P < 0.001) and inhibited by selective chelation (P < 0.001). This problem is not confined to PureSperm(®); analysis of additional commercial sperm preparation media revealed that metal contamination is a relatively constant feature of such products. LIMITATIONS, REASONS FOR CAUTION: While the presence of metals, particularly transition metals, may exacerbate the levels of oxidative DNA damage seen in human spermatozoa, the significance of such damage has not yet been tested in suitably powered clinical trials. WIDER IMPLICATIONS OF THE FINDINGS: The results explain why the preparation of spermatozoa on discontinuous colloidal silicon gradients can result in oxidative DNA damage. The results are of immediate relevance to the development of safe, effective protocols for the preparation of spermatozoa for ART purposes. STUDY FUNDING/COMPETING INTERESTS: The study was funded by the Australian Health and Medical Research Council. One of the authors (R.J.A.) has had a consultantship with a biotechnology company, NuSep, interested in the development of electrophoretic methods of sperm preparation. He has no current financial interest in this area. None of the other authors have a conflict of interest to declare.


Assuntos
Dano ao DNA , Silício/farmacologia , Espermatozoides/efeitos dos fármacos , Centrifugação/efeitos adversos , Estudos de Coortes , Coloides/química , Citometria de Fluxo , Humanos , Peroxidação de Lipídeos , Masculino , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Manejo de Espécimes/efeitos adversos , Espermatozoides/citologia , Elementos de Transição/análise , Elementos de Transição/farmacologia
10.
Vet Rec ; 174(24): 608, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24675772

RESUMO

In recent years, the use of blood chemistry as a diagnostic tool for sea turtles has been demonstrated, but much of its effectiveness relies on reference intervals. The first comprehensive blood chemistry values for healthy wild hawksbill (Eretmochelys imbricata) sea turtles are presented. Nineteen blood chemistry analytes and packed cell volume were analysed for 40 clinically healthy juvenile hawksbill sea turtles captured from a rocky reef habitat in northern Australia. We used four statistical approaches to calculate reference intervals and to investigate their use with non-normal distributions and small sample sizes, and to compare upper and lower limits between methods. Eleven analytes were correlated with curved carapace length indicating that body size should be considered when designing future studies and interpreting analyte values.


Assuntos
Animais Selvagens/sangue , Análise Química do Sangue/veterinária , Hematócrito/veterinária , Tartarugas/sangue , Animais , Valores de Referência
11.
Appetite ; 73: 183-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24246368

RESUMO

OBJECTIVE: Capsaicinoids are a group of chemicals naturally occurring in chilli peppers with bioactive properties that may help to support weight management. The aim of the present study was to conduct a meta-analysis investigating the potential effects of capsaicinoids on energy intake, to clarify previous observations and form evidence-based conclusions about possible weight management roles. METHODS: Medical databases (Medline, Web of Knowledge and Scopus) were systematically searched for papers. Search terms were: 'capsaicin(*)' or 'red pepper' or 'chilli(*)' or 'chili(*)' with 'satiety' or 'energy intake'. Of the seventy-four clinical trials identified, 10 were included, 8 of which provided results suitable to be combined in analysis (191 participants). From the studies, 19 effect sizes were extracted and analysed using MIX meta-analysis software. RESULTS: Data analysis showed that capsaicinoid ingestion prior to a meal reduced ad libitum energy intake by 309.9kJ (74.0kcal) p<0.001 during the meal. Results, however, should be viewed with some caution as heterogeneity was high (I(2)=75.7%). Study findings suggest a minimum dose of 2mg of capsaicinoids is needed to contribute to reductions in ad libitum energy intake, which appears to be attributed to an altered preference for carbohydrate-rich foods over foods with a higher fat content. CONCLUSIONS: Meta-anlysis findings suggest that daily consumption of capsaicinoids may contribute to weight management through reductions in energy intake. Subsequently, there may be potential for capsaicinoids to be used as long-term, natural weight-loss aids. Further long-term randomised trials are now needed to investigate these effects.


Assuntos
Capsaicina/uso terapêutico , Capsicum/química , Ingestão de Energia/efeitos dos fármacos , Obesidade/prevenção & controle , Fitoterapia , Extratos Vegetais/farmacologia , Redução de Peso/efeitos dos fármacos , Capsaicina/farmacologia , Preferências Alimentares/efeitos dos fármacos , Humanos , Extratos Vegetais/uso terapêutico
12.
Eur J Nutr ; 52(2): 429-41, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22886046

RESUMO

BACKGROUND: Vitamin D is a nutrient long considered as essential for skeletal health but is now attracting interest from medical and nutritional communities as knowledge emerges of its biological function and its association with decreased risk of many chronic diseases. RESULTS: A question emerges: How much more vitamin D do we need for these new functions of vitamin D? This review discusses vitamin D physiology and hypovitaminosis D and presents two vitamin D dietary policies: that according to regulatory authorities and that of nutrition scientists. Scientific evidence suggests that 25(OH)D serum levels should be over 75 nmol/L; otherwise, there is no beneficial effect of vitamin D on long-latency diseases. Current regulatory authority recommendations are insufficient to reach this level of adequacy. Observational and some prospective data show that vitamin D has a role in the prevention of cancer as well as immunity, diabetes and cardiovascular and muscle disorders, which supports the actions of 1α,25(OH)2D at cellular and molecular levels. The recent assessments done by the European Food Safety Authority should lead to new health claims. CONCLUSIONS: Vitamin D, through food fortification and supplementation, is a promising new health strategy and thus provides opportunities for food industry and nutrition researchers to work together towards determining how to achieve this potential health benefit.


Assuntos
Suplementos Nutricionais , Vitamina D/administração & dosagem , Vitamina D/metabolismo , Vitamina D/fisiologia , Humanos , Política Nutricional , Deficiência de Vitamina D/fisiopatologia , Deficiência de Vitamina D/prevenção & controle
13.
Biometals ; 24(1): 143-51, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20957409

RESUMO

Trace elements are involved in many key pathways involving cell cycle control. The influence of zinc and zinc chelator (TPEN) on transcription levels of the main zinc transporters (ZnT1 and ZIP1) in the HT-29 colorectal cell line has not been reported. Proliferation of HT-29 cells was measured using the methylene blue assay after exposure to zinc (two concentrations), TPEN (two concentrations), or a combination of zinc and TPEN (simultaneously and sequentially) for 4 h, 8 h, and 24 h. The transcription levels of ZnT1, ZIP1, vascular endothelial growth factor (VEGF), and caspase-3 were determined using reverse transcriptase real-time polymerase chain reaction (RT-PCR) after exposure of cells to zinc and TPEN. The zinc content in the substrate (medium used for culture) was determined using atomic absorption spectrometry. TPEN decreased cellular proliferation causing complete cell death by 8 h. Zinc had a protective effect against short periods of exposure to TPEN. There was no correlation between the transcripts of main zinc transporters and the zinc content in the substrate. The zinc content in the substrate remained constant after varying periods of cell culture. TPEN decreased the transcript levels of caspase-3 and VEGF, which are surrogate markers for apoptosis and angiogenesis. Zinc chelation of HT-29 cells causes cell death. Zinc appears to be protective for short periods of exposure to TPEN but has no protective effect on prolonged exposure. HT-29 cells are not able to counteract the effect of intracellular chelation of zinc by altering zinc transport. Further research into the mechanisms of these findings is necessary and may lead to novel therapeutic options.


Assuntos
Quelantes/farmacologia , Etilenodiaminas/farmacologia , Zinco/farmacologia , Caspase 3/genética , Caspase 3/metabolismo , Proliferação de Células/efeitos dos fármacos , Quelantes/química , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Etilenodiaminas/química , Células HT29 , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Zinco/química
14.
J Food Sci ; 74(1): S36-43, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19200119

RESUMO

USDA Select striploins (IMPS 180; n= 24) were cut into thirds (anterior, medial, and posterior) and assigned to 1 of 8 treatments utilizing a randomized incomplete block design. Treatments included (1) control (C); (2) 1.5% conjugated linoleic acid (conjugated linoleic acid = CLA) (CGA); (3) 0.4% sodium tripolyphosphate (PHO); (4) 0.5% salt (SAL); (5) 0.4% sodium tripolyphosphate, 0.5% salt (SPH); (6) 0.4% sodium tripolyphosphate, 1.5% CLA (PCL); (7) 0.5% salt, 1.5% CLA (SCL); and (8) 0.4% sodium tripolyphosphate, 0.5% salt, 1.5% CLA (SPC). Treatments were injected with solutions to 110% (10% pump) of their original weight. Treatments with CLA had higher (P < 0.05) marbling scores than treatments that did not. Not including SAL, treatments with salt, or phosphate or a combination of the two had higher tenderness values when sampled by panelists. Fresh steaks with inclusion of CLA had greater amounts (P < 0.05) of the CLA isomers than steaks not having CLA. Cooked steaks having CLA also had greater amounts (P < 0.05) of CLA, except for SCL, which were not different (P > 0.05) from the non-CLA treatments. Day was a significant source of variability for a*, b*, and saturation index. Treatment x day interactions were significant (P < 0.05) for hue angle and L* values. These data suggest that inclusion of CLA can increase amounts of CLA isomers without major deleterious effects to instrumental, physical, and quality characteristics of beef striploin steaks.


Assuntos
Conservação de Alimentos/métodos , Ácidos Linoleicos Conjugados/farmacologia , Carne/normas , Pigmentação/efeitos dos fármacos , Polifosfatos/farmacologia , Cloreto de Sódio/farmacologia , Animais , Bovinos , Estudos Cross-Over , Sinergismo Farmacológico , Conservantes de Alimentos/farmacologia , Humanos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
15.
Neurology ; 72(3): 232-9, 2009 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-19153370

RESUMO

BACKGROUND: The incidence of acquired demyelination of the CNS (acquired demyelinating syndromes [ADS]) in children is unknown. It is important that physicians recognize the features of ADS to facilitate care and to appreciate the future risk of multiple sclerosis (MS). OBJECTIVE: To determine the incidence, clinical features, familial autoimmune history, and acute management of Canadian children with ADS. METHODS: Incidence and case-specific data were obtained through the Canadian Pediatric Surveillance Program from April 1, 2004, to March 31, 2007. Before study initiation, a survey was sent to all pediatric health care providers to determine awareness of MS as a potential outcome of ADS in children. RESULTS: Two hundred nineteen children with ADS (mean age 10.5 years, range 0.66-18.0 years; female to male ratio 1.09:1) were reported. The most common presentations were optic neuritis (ON; n = 51, 23%), acute disseminated encephalomyelitis (ADEM; n = 49, 22%), and transverse myelitis (TM; n = 48, 22%). Children with ADEM were more likely to be younger than 10 years, whereas children with monolesional ADS (ON, TM, other) were more likely to be older than 10 years (p < 0.001). There were 73 incident cases per year, leading to an annual incidence of 0.9 per 100,000 Canadian children. A family history of MS was reported in 8%. Before study initiation, 65% of physicians indicated that they considered MS as a possible outcome of ADS in children. This increased to 74% in year 1, 81% in year 2, and 87% in year 3. CONCLUSION: The incidence of pediatric acquired demyelinating syndromes (ADS) is 0.9 per 100,000 Canadian children. ADS presentations are influenced by age.


Assuntos
Doenças do Sistema Nervoso Central/epidemiologia , Doenças Desmielinizantes/epidemiologia , Adolescente , Distribuição por Idade , Canadá/epidemiologia , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/tratamento farmacológico , Criança , Pré-Escolar , Demografia , Doenças Desmielinizantes/diagnóstico , Doenças Desmielinizantes/tratamento farmacológico , Encefalomielite Aguda Disseminada/epidemiologia , Feminino , Glucocorticoides/administração & dosagem , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Incidência , Lactente , Injeções Intravenosas , Imageamento por Ressonância Magnética , Masculino , Metilprednisolona/administração & dosagem , Mielite Transversa/epidemiologia , Neurite Óptica/epidemiologia , Distribuição por Sexo
17.
Open AIDS J ; 2: 39-42, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18923701

RESUMO

The use of nucleoside reverse transcriptase inhibitors in the treatment of HIV infection is associated with antiretroviral toxic polyneuropathy (ATN). Previous studies suggest that long term treatment with Acetyl-L-carnitine (ALCAR) 1.5 gram twice daily improves symptoms and promotes nerve regeneration. It is unknown whether the drug's pharmacokinetic profile would allow for a once daily administration. Twenty three HIV-1 infected subjects taking ALCAR for ATN were enrolled in a cross over trial and switched from twice to once daily dosing. Their regimen was changed from 1.5 g twice daily to 1g (4 patients), 2g (7), and 3g (12) once daily, respectively. Twelve healthy volunteers served as control. Plasma levels of ALCAR and its metabolite L-carnitine were measured. Patients receiving ALCAR had higher pre-dose levels than control subjects. Post dose levels were not significantly higher than pre dose levels in any treatment group. The pre / post dose ALCAR concentrations were 7.6 / 7.7, 7.1 / 6.8, 7.7 / 6.8, and 7.1 / 7.5 micromol/l for 1.5 g twice daily, 1g once daily, 2g once daily, and 3g once daily, respectively. All values were significantly higher than the mean concentration in the control group (4.3 micromol/l). For ALCAR and L-carnitine, measurements for once daily regimens did not differ from the twice daily regimen. Once daily dosing of ALCAR can achieve similar plasma levels as twice daily dosing but intra-mitochondrial levels remain unknown. The pharmacokinetic profile of orally administered ALCAR is complex and likely to be highly affected by endogenous concentrations.

18.
Eur J Clin Nutr ; 62(3): 373-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17342165

RESUMO

OBJECTIVE: To describe the vitamin D status of women living in two Asian cities,--Jakarta (6 degrees S) and Kuala-Lumpur (2 degrees N), to examine the association between plasma 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations, and to determine a threshold for plasma 25-hydroxyvitamin D above which there is no further suppression of PTH. Also, to determine whether dietary calcium intake influences the relationship between PTH and 25-hydroxyvitamin D. DESIGN: Cross-sectional. SETTING: Jakarta, Indonesia and Kuala Lumpur, Malaysia. PARTICIPANTS: A convenience sample of 504 non-pregnant women 18-40 years. MAIN MEASURES: Plasma 25-hydroxyvitamin D and PTH. RESULTS: The mean 25-hydroxyvitamin D concentration was 48 nmol/l. Less than 1% of women had a 25-hydroxyvitamin D concentration indicative of vitamin D deficiency (<17.5 nmol/l); whereas, over 60% of women had a 25-hydroxyvitamin D concentration indicative of insufficiency (<50 nmol/l). We estimate that 52 nmol/l was the threshold concentration for plasma 25-hydroxyvitamin D above which no further suppression of PTH occurred. Below and above this concentration the slopes of the regression lines were -0.18 (different from 0; P=0.003) and -0.01 (P=0.775), respectively. The relation between vitamin D status and parathyroid hormone concentration did not differ between women with low, medium or high calcium intakes (P=0.611); however, even in the highest tertile of calcium intake, mean calcium intake was only 657 mg/d. CONCLUSION: On the basis of maximal suppression of PTH we estimate an optimal 25-hydroxyvitamin D concentration of approximately 50 nmol/l. Many women had a 25-hydroxyvitamin D below this concentration and may benefit from improved vitamin D status.


Assuntos
Estado Nutricional , Hormônio Paratireóideo/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/fisiopatologia , Vitamina D/sangue , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Indonésia , Malásia , Vitamina D/análogos & derivados , Saúde da Mulher
19.
J Nutr Health Aging ; 7(5): 296-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12917743

RESUMO

BACKGROUND: The optimal intake of calcium and vitamin D for postmenopausal women not taking estrogen is not known. Further, there are indications that excess vitamin A as retinol might be detrimental to bone. OBJECTIVE: We determined whether dietary intakes of calcium and vitamin D were important for maintaining cortical and trabecular bone mineral density (BMD). We also determined whether nutrient supplements increased retinol intake to a level that would reduce BMD. DESIGN: This was a cross-sectional study of 58 women, age 45-75 years. Dietary intakes and lifestyle factors were assessed by retrospective questionnaires. BMD at the whole body, lumbar spine, and proximal femur (including neck, trochanter, and Wards) was measured using dual energy x-ray absorptiometry (DXA) bone densitometry. RESULTS: There were significant (p < 0.05) positive correlations between total calcium intake and BMD at all sites except spine. At the trochanter, the correlation between total vitamin D and BMD was significant while that between total retinol and BMD showed a trend (p < 0.10). In a stepwise multiple regression, a significant proportion of variance of BMD was accounted for by years since menopause (8.0 to 36.2 %) and body weight (14.5 to 27.1%) at most bone sites. Adding total calcium intake (food + supplements) into the model further accounted for a significant proportion of variance of BMD at cortical bone sites such as hip, femoral neck, Wards, and total body ( 5.2 - 8.4 %). There was no dietary calcium effect on BMD at the spine. CONCLUSION: The positive effect of total calcium intake on cortical BMD of postmenopausal women not taking estrogen suggests that supplemental calcium use is critical for maintaining bone mass. Increased retinol intake from nutrient supplements had no adverse effect on BMD.


Assuntos
Densidade Óssea/efeitos dos fármacos , Cálcio da Dieta/administração & dosagem , Osteoporose Pós-Menopausa/etiologia , Vitamina A/administração & dosagem , Vitamina D/administração & dosagem , Idoso , Peso Corporal/fisiologia , Densidade Óssea/fisiologia , Estudos de Coortes , Estudos Transversais , Suplementos Nutricionais , Estrogênios/administração & dosagem , Feminino , Humanos , Estilo de Vida , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , Pós-Menopausa , Inquéritos e Questionários , Fatores de Tempo , Vitamina A/efeitos adversos
20.
Chemosphere ; 52(9): 1571-9, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12867190

RESUMO

Wetland microcosms were used to evaluate the ability of constructed wetlands to remove extremely high concentrations of selenocyanate (SeCN-), arsenic (As), and boron (B) from wastewater generated by a coal gasification plant in Indiana. The wetland microcosms significantly reduced the concentrations of selenium (Se), As, B, and cyanide (CN) in the wastewater by 64%, 47%, 31%, and 30%, respectively. In terms of the mass of each contaminant, 79%, 67%, 57%, and 54% of the Se, As, B, and CN, respectively, loaded into the microcosms were removed from the wastewater. The primary sink for the retention of contaminants within the microcosms was the sediment, which accounted for 63%, 51%, and 36% of the Se, As, and B, respectively. Accumulation in plant tissues accounted for only 2-4%, while 3% of the Se was removed by biological volatilization to the atmosphere. Of the 14 plant species tested, cattail, Thalia, and rabbitfoot grass were highly tolerant of the contaminants and exhibited no growth retardation. Environmental toxicity testing with fathead minnow (Pimephales promelas) larvae confirmed that the water treated by the wetland microcosms was less toxic than untreated water. The data from the wetland microcosms support the view that constructed wetlands could be used to successfully reduce the toxicity of aqueous effluent contaminated with extremely high concentrations of SeCN-, As, and B, and that a pilot-scale wetland should therefore be constructed to test this in the field. Cattail, Thalia, and rabbitfoot grass would be suitable plant species to establish in such wetlands.


Assuntos
Arsênio/isolamento & purificação , Boro/isolamento & purificação , Cianatos/isolamento & purificação , Ecossistema , Compostos de Selênio/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Microbiologia da Água , Purificação da Água/métodos , Animais , Arsênio/análise , Arsênio/farmacocinética , Intoxicação por Arsênico/prevenção & controle , Biomassa , Boro/análise , Boro/farmacocinética , Boro/intoxicação , Cianatos/análise , Cianatos/farmacocinética , Cianatos/intoxicação , Cyprinidae , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Raízes de Plantas/química , Brotos de Planta/química , Plantas/metabolismo , Compostos de Selênio/análise , Compostos de Selênio/farmacocinética , Compostos de Selênio/intoxicação , Distribuição Tecidual , Volatilização , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/farmacocinética
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