RESUMO
Diluted bitumen (dilbit) is an unconventional oil produced by the oil sands industry in Canada. Despite the knowledge available on hydrocarbon toxicity, the effects of diluted bitumen on benthic organisms are still largely unknown. Moreover, in Quebec there are only provisional threshold values of 164 mg/kg C10-C50 for chronic effects and 832 mg/kg for acute effects. The protectiveness of these values for benthic invertebrates has not been tested for heavy unconventional oils such as dilbit. Two benthic organisms, the larvae of Chironomus riparius and Hyalella azteca, were exposed to these two concentrations and to an intermediate concentration (416 mg/kg) of two dilbits (DB1 and DB2) and a heavy conventional oil (CO). The aim of the study was to assess the sublethal and lethal effects of spiked sediment by dilbit. The oil was rapidly degraded in the sediment, especially in the presence of C. riparius. Amphipods were much more sensitive to oil than chironomids. LC50-14d values for H. azteca were 199 mg/kg C10-C50 for DB1, 299 mg/kg for DB2 and 8.42 mg/kg for CO compared to LC50-7d values for C. riparius of 492 mg/kg for DB1, 563 mg/kg for DB2 and 514 mg/kg for CO. The size of the organisms was reduced compared to controls for both species. The defense enzymes (GST, GPx, SOD and CAT) were not good biomarkers in these two organisms for this type of contamination. The current provisional sediment quality criteria seem too permissive for heavy oils and should be lowered.
Assuntos
Anfípodes , Poluentes Químicos da Água , Animais , Campos de Petróleo e Gás , Invertebrados , Água Doce , Hidrocarbonetos/toxicidade , Gestão de Riscos , Óleos , Poluentes Químicos da Água/toxicidade , Sedimentos GeológicosRESUMO
BACKGROUND: The objective of this study was to develop and validate a short, self-administered questionnaire to assess diet quality in clinical settings, using the Alternative Healthy Eating Index (AHEI) as reference. METHODS: A total of 1040 men and women (aged 44.6 ± 14.4 y) completed a validated web-based food frequency questionnaire (webFFQ) and had their height and weight measured (development sample). Participants were categorized arbitrarily according to diet quality (high: AHEI score ≥ 65/110, low: AHEI score < 65/110) based on dietary intake data from the webFFQ. The Brief Diet Quality Assessment Tool was developed using a classification and regression tree (CART) approach and individual answers to the webFFQ among participants considered to have a plausible energy intake (ratio of reported energy intake to basal metabolic rate ≥ 1.2 and < 2.4; n = 1040). A second sample of 3344 older adults (aged 66.5 ± 6.4 y) was used to test the external validity of the Brief Diet Quality Assessment Tool (external validation sample). RESULTS: The decision tree included sequences of 3 to 6 binary questions, yielding 21 different pathways classifying diet quality as being high or low. In the development sample, the area under the receiver operating characteristic (ROC) curve of the predictive model was 0.92, with sensitivity, specificity and agreement values of 89.5, 83.9 and 87.2%. Compared with individuals having a low-quality diet according to the Brief Diet Quality Assessment Tool (mean AHEI 56.7 ± 11.4), individuals classified as having a high-quality diet (mean AHEI 71.3 ± 11.0) were significantly older, and had lower BMI, percent body fat and waist circumference, and had lower blood pressure, triglycerides, cholesterol/HDL ratio and fasting insulin as well as higher HDL-cholesterol concentrations (all P < 0.05). Similar results were observed in the external validation sample, although overall performance of the Brief Diet Quality Assessment Tool was slightly lower than in the development sample, with an area under the ROC curve of 0.79 and sensitivity, specificity and agreement values of 73.0, 69.0 and 71.3%, respectively. CONCLUSION: The CART approach yielded a simple and rapid Brief Diet Quality Assessment Tool that identifies individuals at risk of having a low-quality diet. Further studies are needed to test the performance of this tool in primary care settings.
Assuntos
Inquéritos sobre Dietas/normas , Dieta/estatística & dados numéricos , Valor Nutritivo/fisiologia , Inquéritos e Questionários/normas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , QuebequeRESUMO
BACKGROUND AND PURPOSE: The purpose of the study is to characterize diffusion tensor imaging indices in the developing spinal cord, evaluating differences based on age and cord region. Describing the progression of DTI indices in the pediatric cord increases our understanding of spinal cord development. MATERIALS AND METHODS: A retrospective analysis was performed on DTI acquired in 121 pediatric patients (mean, 8.6 years; range, 0.3-18.0 years) at Monroe Carell Jr. Children's Hospital at Vanderbilt from 2017 to 2018. Diffusion-weighted images (15 directions; b = 750 s/mm2; slice thickness, 5 mm; in-plane resolution, 1.0 × 1.0 mm2) were acquired on a 3T scanner in the cervicothoracic and/or thoracolumbar cord. Manual whole-cord segmentation was performed. Images were masked and further segmented into cervical, upper thoracic, thoracolumbar, and conus regions. Analyses of covariance were performed for each DTI-derived index to investigate how age affects diffusion across cord regions, and 95% confidence intervals were calculated across age for each derived index and region. Post hoc testing was performed to analyze regional differences. RESULTS: Analyses of covariance revealed significant correlations of age with axial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001). There were also significant differences among cord regions for axial diffusivity, radial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001). CONCLUSIONS: This research demonstrates that diffusion evolves in the pediatric spinal cord during development, dependent on both cord region and the diffusion index of interest. Future research could investigate how diffusion may be affected by common pediatric spinal pathologies.
Assuntos
Imagem de Tensor de Difusão/métodos , Processamento de Imagem Assistida por Computador/métodos , Neurogênese , Neuroimagem/métodos , Medula Espinal/crescimento & desenvolvimento , Adolescente , Algoritmos , Anisotropia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos RetrospectivosRESUMO
BACKGROUND: Chilblains are inflammatory dermal lesions associated with hypersensitivity to cold, and they occur on the extremities bilaterally and symmetrically. Their onset during the course of pro-thermogenic and autoimmune diseases has been widely reported, but the association with predisposing locoregional causes is not well known. PATIENTS AND METHODS: Case 1: a 57-year-old man, who smoked 80 packets per year, presenting a deficit of the levator muscles in his right foot following lumbar sciatica with paralysis of L5, consulted for unilateral necrotic lesions of the toes recurring each winter in the paralysed limb only. Case 2: a 60-year-old man had a previous history of liposarcoma of the right side treated with radiotherapy and surgery, resulting in sequelae of monoparesis and radiation-induced arteritis. Each winter, he presented recurring unilateral purpuric macules of the toes on his right foot, with no necrotic progression. In both cases, clinical examination, disease progression over time, histology and laboratory tests confirmed the diagnosis of idiopathic chilblains. CONCLUSION: The physiopathological hypotheses posited to account for the unilateral appearance of chilblains in the event of paralysis include decreased blood flow to the paralysed limb, imbalance in neuromodulators, dysfunction of the autonomous nervous system, cutaneous atrophy with hypertrophy of underlying soft tissues, and finally, hypoesthesia aggravating the trophic disorders.
Assuntos
Pérnio/etiologia , Paresia/complicações , Pérnio/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Measuring the effects of selection on the genome imposed by human-altered environment is currently a major goal in ecological genomics. Given the polygenic basis of most phenotypic traits, quantitative genetic theory predicts that selection is expected to cause subtle allelic changes among covarying loci rather than pronounced changes at few loci of large effects. The goal of this study was to test for the occurrence of polygenic selection in both North Atlantic eels (European Eel, Anguilla anguilla and American Eel, A. rostrata), using a method that searches for covariation among loci that would discriminate eels from 'control' vs. 'polluted' environments and be associated with specific contaminants acting as putative selective agents. RAD-seq libraries resulted in 23 659 and 14 755 filtered loci for the European and American Eels, respectively. A total of 142 and 141 covarying markers discriminating European and American Eels from 'control' vs. 'polluted' sampling localities were obtained using the Random Forest algorithm. Distance-based redundancy analyses (db-RDAs) were used to assess the relationships between these covarying markers and concentration of 34 contaminants measured for each individual eel. PCB153, 4'4'DDE and selenium were associated with covarying markers for both species, thus pointing to these contaminants as major selective agents in contaminated sites. Gene enrichment analyses suggested that sterol regulation plays an important role in the differential survival of eels in 'polluted' environment. This study illustrates the power of combining methods for detecting signals of polygenic selection and for associating variation of markers with putative selective agents in studies aiming at documenting the dynamics of selection at the genomic level and particularly so in human-altered environments.
Assuntos
Anguilla/genética , Genética Populacional , Metais/efeitos adversos , Seleção Genética , Poluentes Químicos da Água/efeitos adversos , Anguilla/classificação , Animais , Meio Ambiente , Genótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
This clinical trial investigated the impact of a six-week supplementation with fish oil and single nucleotide polymorphisms (SNPs) in PLA2G4A and PLA2G6 genes on total omega-6 fatty acid (n-6 FA) levels in plasma phospholipids (PL) and plasma C-reactive protein (CRP) levels in 191 subjects. Interaction effects between SNPs and supplementation modulated total n-6 FAs and CRP levels in both men and women. Associations between SNPs and total n-6 FA levels and between SNPs and CRP levels were identified in men, independently of supplementation. Supplementation decreased total n-6 FAs without affecting plasma CRP levels. Changes in CRP levels correlated positively with changes in total n-6 FAs in men (r=0.25 p=0.01), but not in women. In conclusion, total n-6 FA levels in plasma PL and plasma CRP levels are modulated by SNPs within PLA2G4A and PLA2G6 genes alone or in combination with fish oil supplementation.
Assuntos
Proteína C-Reativa/análise , Suplementos Nutricionais , Ácidos Graxos Ômega-6/sangue , Óleos de Peixe/administração & dosagem , Fosfolipases A2 do Grupo IV/genética , Fosfolipases A2 do Grupo VI/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/metabolismo , Índice de Massa Corporal , Ácidos Graxos Ômega-6/administração & dosagem , Ácidos Graxos Ômega-6/análise , Ácidos Graxos Ômega-6/antagonistas & inibidores , Feminino , Óleos de Peixe/metabolismo , Estudos de Associação Genética , Fosfolipases A2 do Grupo IV/metabolismo , Fosfolipases A2 do Grupo VI/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Nutrigenômica/métodos , Sobrepeso/sangue , Sobrepeso/genética , Sobrepeso/metabolismo , Fosfolipídeos/sangue , Fosfolipídeos/química , Quebeque , Caracteres Sexuais , Adulto JovemRESUMO
BACKGROUND AND AIM: Compared to a DASH-type diet, an intensively applied dietary portfolio reduced diastolic blood pressure at 24 weeks as a secondary outcome in a previous study. Due to the importance of strategies to reduce blood pressure, we performed an exploratory analysis pooling data from intensively and routinely applied portfolio treatments from the same study to assess the effect over time on systolic, diastolic and mean arterial pressure (MAP), and the relation to sodium (Na(+)), potassium (K(+)), and portfolio components. METHODS AND RESULTS: 241 participants with hyperlipidemia, from four academic centers across Canada were randomized and completed either a DASH-type diet (control n = 82) or a dietary portfolio that included, soy protein, viscous fibers and nuts (n = 159) for 24 weeks. Fasting measures and 7-day food records were obtained at weeks 0, 12 and 24, with 24-h urines at weeks 0 and 24. The dietary portfolio reduced systolic, diastolic and mean arterial blood pressure compared to the control by 2.1 mm Hg (95% CI, 4.2 to -0.1 mm Hg) (p = 0.056), 1.8 mm Hg (CI, 3.2 to 0.4 mm Hg) (p = 0.013) and 1.9 mm Hg (CI, 3.4 to 0.4 mm Hg) (p = 0.015), respectively. Blood pressure reductions were small at 12 weeks and only reached significance at 24 weeks. Nuts, soy and viscous fiber all related negatively to change in mean arterial pressure (ρ = -0.15 to -0.17, p ≤ 0.016) as did urinary potassium (ρ = -0.25, p = 0.001), while the Na(+)/K(+) ratio was positively associated (ρ = 0.20, p = 0.010). CONCLUSIONS: Consumption of a cholesterol-lowering dietary portfolio also decreased blood pressure by comparison with a healthy DASH-type diet. CLINICAL TRIAL REG. NO.: NCT00438425, clinicaltrials.gov.
Assuntos
Doenças Cardiovasculares/dietoterapia , Registros de Dieta , Dieta com Restrição de Gorduras/métodos , Dieta Hipossódica/métodos , Hiperlipidemias/dietoterapia , Hipertensão/dietoterapia , Adulto , Idoso , Determinação da Pressão Arterial/métodos , Canadá , Doenças Cardiovasculares/prevenção & controle , Dieta Mediterrânea , Ingestão de Energia , Feminino , Seguimentos , Humanos , Hiperlipidemias/prevenção & controle , Hipertensão/prevenção & controle , Masculino , Pessoa de Meia-Idade , Medição de Risco , Resultado do TratamentoRESUMO
AIM: To compare the impact of covered stent-graft transjugular intrahepatic portosystemic shunt (TIPS) versus serial paracentesis on survival of patients with medically refractory ascites. MATERIALS AND METHODS: In this retrospective study, cirrhotic patients who underwent covered stent-graft TIPS for refractory ascites from 2003-2013 were compared with similar patients who underwent serial paracentesis during 2009-2013. Demographic and liver disease data, Model for End-Stage Liver Disease (MELD) scores, and survival outcomes were obtained from hospital electronic medical records and the social security death index. After propensity score weighting to match study group characteristics, survival outcomes were compared using Kaplan-Meier statistics with log-rank analysis. RESULTS: Seventy TIPS (70% men, mean age 55.7 years, mean MELD 15.1) and 80 paracentesis (58% men, mean age 53.5 years, mean MELD 22.5) patients were compared. The TIPS haemodynamic success rate was 100% (mean portosystemic pressure gradient reduction 13 mmHg). Paracentesis patients underwent a mean of 7.9 procedures. After propensity score weighting to balance group features, TIPS patients showed a trend toward enhanced survival compared with paracentesis patients (median survival 1037 versus 262 days, p = 0.074). TIPS conferred a significant increase or trend toward improved survival compared with paracentesis at 1 (66% versus 44%, p = 0.018), 2 (56% versus 38%, p = 0.057), and 3 year (49% versus 32%, p = 0.077) time points. Thirty and 90 day mortality rates were not statistically increased by TIPS. CONCLUSION: Covered stent-graft TIPS improves intermediate- to long-term survival without significantly increasing short-term mortality of ascites patients, and suggests a greater potential role for TIPS in properly selected ascitic patients when medical management fails.
Assuntos
Ascite/etiologia , Ascite/cirurgia , Cirrose Hepática/complicações , Paracentese/métodos , Derivação Portossistêmica Transjugular Intra-Hepática , Ascite/diagnóstico por imagem , Estudos de Casos e Controles , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento , Ultrassonografia DopplerRESUMO
BACKGROUND AND AIMS: Little is known about the effect of various dietary fatty acids on pro- and anti-inflammatory processes. We investigated the effect of 5 oils containing various amounts of alpha-linolenic acid (ALA), linoleic acid (LA), oleic acid (OA) and docosahexaenoic acid (DHA) on plasma inflammatory biomarkers and expression levels of key inflammatory genes and transcription factors in whole blood cells. METHODS AND RESULTS: In a randomized, crossover controlled nutrition intervention, 114 adult men and women with abdominal obesity and at least one other criterion for the metabolic syndrome consumed 5 experimental isoenergetic diets for 4 weeks each, separated by 4-week washout periods. Each diet provided 60 g/3000 kcal of different oils: 1) control corn/safflower oil blend (CornSaff; LA-rich), 2) flax/safflower oil blend (FlaxSaff; ALA-rich), 3) conventional canola oil (Canola; OA-rich), 4) high oleic canola oil (CanolaOleic; highest OA content), 5) DHA-enriched high oleic canola oil (CanolaDHA; OA- and DHA-rich). Gene expression in whole blood cells was assessed in a subset of 62 subjects. CanolaDHA increased plasma adiponectin concentrations compared with the control CornSaff oil treatment (+4.5%, P = 0.04) and FlaxSaff (+6.9%, P = 0.0008). CanolaDHA also reduced relative expression levels of interleukin (IL)1B compared with CornSaff and Canola (-11% and -13%, respectively, both P = 0.03). High-sensitivity C-reactive protein concentrations were lower after Canola than after FlaxSaff (-17.8%, P = 0.047). CONCLUSION: DHA-enriched canola oil exerts anti-inflammatory effects compared with polyunsaturated fatty acids from plant sources.
Assuntos
Adiponectina/agonistas , Anti-Inflamatórios não Esteroides/uso terapêutico , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácidos Graxos Monoinsaturados/uso terapêutico , Mediadores da Inflamação/antagonistas & inibidores , Síndrome Metabólica/prevenção & controle , Obesidade Abdominal/dietoterapia , Adiponectina/sangue , Adulto , Idoso , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/química , Biomarcadores/sangue , Biomarcadores/metabolismo , Células Sanguíneas/imunologia , Células Sanguíneas/metabolismo , Índice de Massa Corporal , Canadá/epidemiologia , Estudos Cross-Over , Ácidos Docosa-Hexaenoicos/análise , Método Duplo-Cego , Ácidos Graxos Monoinsaturados/química , Feminino , Alimentos Fortificados , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , Obesidade Abdominal/imunologia , Obesidade Abdominal/metabolismo , Obesidade Abdominal/fisiopatologia , Pennsylvania/epidemiologia , Óleo de Brassica napus , Risco , Adulto JovemRESUMO
The accumulation of metals in tissue compartments of bivalve biomonitors is expected to reflect the phases in which metals are most bioavailable. In concurrent field and laboratory experiments we measured Zn, Cd and Pb concentrations in the gills and digestive glands of mussels exposed to sediments from Lake Macquarie in NSW, Australia. Mussels in the laboratory were also exposed to the bioturbating gastropod Batillaria australis. Zn, Cd and Pb concentrations in gills and digestive glands of mussels from both experiments were accumulated in proportion with levels of metal contamination in the sediments. An interaction in the field between site and tissue type was found for Cd and Pb suggesting variation in the phases in which metals are most bioavailable. No effect of bioturbation on metal accumulation in the bivalve was detected and we conclude that it is unlikely to be a significant factor in metal uptake when these species interact.
Assuntos
Sedimentos Geológicos/química , Metais/toxicidade , Mytilidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Austrália , Disponibilidade Biológica , Trato Gastrointestinal/química , Trato Gastrointestinal/efeitos dos fármacos , Brânquias/química , Brânquias/efeitos dos fármacos , Lagos , Metais/análise , Metais/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinéticaRESUMO
BACKGROUND/OBJECTIVES: We examined the prevalence of elevated plasma high-sensitivity C-reactive protein (hs-CRP) concentrations and associations with red blood cell (RBC) long-chain n-3 polyunsaturated fatty acids (LCn-3PUFA) in the James Bay Cree population from the province of Quebec (Canada). SUBJECTS/METHODS: A total of 744 Cree adults (18-91 years) from seven communities of Eastern James Bay were included in these cross-sectional analyses. Associations between RBC LCn-3PUFA and proinflammatory markers (hs-CRP, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)) were assessed by using multivariate general linear models with adjustment for sex, age and waist circumference. An arbitrary inflammation score was defined based on the sum of the quartiles of hs-CRP, IL-6 and TNF-α concentrations (range=3-12). RESULTS: Elevated hs-CRP concentrations (>3 mg/l) were present in 46.9% (95% confidence interval (CI) 43.3-50.5) of the James Bay Cree population. RBC docosapentaenoic acid (DPAn-3; C22:5n-3) was inversely associated with hs-CRP, TNF-α and the inflammation score (all P trend<0.02), whereas eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) in RBC were not associated with inflammation (all P trend>0.18). Among participants with RBC DPAn-3 levels above the median of the population, odds ratio of having an elevated inflammation score (≥9) was 0.67 (95% CI, 0.48-0.93) compared with participants below the median. CONCLUSIONS: RESULTS indicate that low-grade systemic inflammation is highly prevalent and that higher RBC DPAn-3 levels are associated with a lower risk of systemic inflammation in the James Bay Cree population.
Assuntos
Proteína C-Reativa/metabolismo , Eritrócitos/metabolismo , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Insaturados/sangue , Indígenas Norte-Americanos , Inflamação/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto , Biomarcadores/sangue , Estudos Transversais , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Feminino , Humanos , Inflamação/epidemiologia , Interleucina-6/sangue , Masculino , Prevalência , Quebeque/epidemiologiaRESUMO
AIM: To investigate the effects of sitagliptin therapy on the kinetics of triglyceride-rich lipoprotein (TRL) apolipoprotein (apo)B-48, VLDL apoB-100, apoE and apoC-III in patients with type 2 diabetes. METHODS: Twenty-two subjects with type 2 diabetes were recruited in this double-blind crossover study, during which the subjects received sitagliptin (100 mg/day) or placebo for a 6-week period each. At the end of each phase of treatment, the in vivo kinetics of the different apolipoproteins were assessed using a primed-constant infusion of l-[5,5,5-D3]leucine for 12 h, with the participants in a constantly fed state. RESULTS: Sitagliptin therapy significantly reduced fasting plasma triglyceride (-15.4%, p = 0.03), apoB-48 (-16.3%, p = 0.03) and free fatty acid concentrations (-9.5%, p = 0.04), as well as plasma HbA1c (placebo: 7.0% ± 0.8 vs. sitagliptin: 6.6% ± 0.7, p < 0.0001) and plasma glucose levels (-13.5%, p = 0.001), without any significant effect on insulin levels. Kinetic results showed that treatment with sitagliptin significantly reduced the pool size of TRL apoB-48 by -20.8% (p = 0.03), paralleled by a reduction in the production rate of these particles (-16.0%, p = 0.03). The VLDL apoB-100 pool size was also significantly decreased by sitagliptin therapy (-9.3%, p = 0.03), mainly because of a reduction in the hepatic secretion of these lipoproteins, although this difference did not reach statistical significance (-9.2%, p = 0.06). CONCLUSIONS: Treatment with sitagliptin for 6 weeks reduced triglyceride-rich apoB-containing lipoprotein levels by reducing the synthesis of these particles.
Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/farmacologia , Dislipidemias/sangue , Hemoglobinas Glicadas/efeitos dos fármacos , Pirazinas/farmacologia , Triazóis/farmacologia , Apolipoproteína B-48/sangue , Apolipoproteína B-48/efeitos dos fármacos , Apolipoproteínas/sangue , Apolipoproteínas/efeitos dos fármacos , Glicemia/metabolismo , Estudos Cross-Over , Diabetes Mellitus Tipo 2/sangue , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Método Duplo-Cego , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Pirazinas/administração & dosagem , Fosfato de Sitagliptina , Resultado do Tratamento , Triazóis/administração & dosagem , Triglicerídeos/sangueRESUMO
What we generally refer to as 'vitamin A' is a group of naturally-occurring molecules structurally similar to retinol that are capable of exerting biological activity. These retinoids are essential to diverse physiological functions including vision, immune response, bone mineralization, reproduction, cell differentiation, and growth. As well, some retinoids have antioxidant properties. Independent studies published over the last few decades have revealed that many fish and wildlife populations living in highly polluted environments have altered retinoid status possibly associated with retinoid metabolic or homeostatic mechanisms. Substantial evidence links organic contaminant exposure with changes in retinoid status in animal populations, but only a few detailed studies have been published implicating inorganic contaminants such as metals. This mini-review selectively deals with field and laboratory studies reporting associations between environmental contaminants, especially trace metals, and alterations in retinoid status. Both essential and non-essential trace metals have been reported to affect retinoid status. This review focuses on metabolic imbalances of retinoids in relation to metal contamination and illustrates possible modes of action. The role of retinoids as antioxidants and their potential as biomarkers of metal contamination are discussed.
Assuntos
Antioxidantes/metabolismo , Poluentes Ambientais/efeitos adversos , Metais/efeitos adversos , Retinoides/metabolismo , Animais , Antioxidantes/efeitos adversos , Biomarcadores/metabolismo , Aves , Ecossistema , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental/métodos , Peixes , Hipervitaminose A/metabolismo , Mamíferos , Retinoides/efeitos adversos , Medição de RiscoRESUMO
BACKGROUND AND AIMS: Sphingolipids (SL) are important components of the milk fat globule membrane (MFGM) found in buttermilk. While studies in animal models suggest that dietary SL may have cholesterol-lowering properties, data in human are lacking. The aim of this study was to investigate the impact of buttermilk consumption on plasma lipids and surrogate markers of cholesterol (C) homeostasis in humans. METHODS AND RESULTS: Men and women (n = 34) with serum LDL-C <5.0 mmol/L at screening (mean LDL-C = 3.8 mmol/L) were recruited in this double-blinded randomized crossover placebo controlled study. Their diets were supplemented with 45 g/d of buttermilk and with 45 g/d of a macro/micronutrient matched placebo (4 weeks each in random order). Serum lipid concentrations and surrogate markers of cholesterol homeostasis were measured post diet and compared using mixed models for repeated measures. Consumption of buttermilk led to reduction in serum cholesterol (-3.1%, P = 0.019), LDL-C (-3.1%, P = 0.057) and triacylglycerol (-10.7%, P = 0.007). Buttermilk consumption increased plasma lathosterol concentrations (+12.1%, P = 0.001), but multiple regression analysis indicated that variations in ß-sitosterol concentrations (P = 0.002) were the only significant predictor of the LDL-C response to buttermilk consumption. CONCLUSION: Buttermilk consumption may be associated with reduced cholesterol concentrations in men and women, primarily through inhibition of intestinal absorption of cholesterol. REGISTRATION NUMBER: This trial is registered at clinicaltrials.gov as NCT01248026.
Assuntos
Biomarcadores/sangue , LDL-Colesterol/sangue , Produtos Fermentados do Leite , Homeostase/fisiologia , Adolescente , Adulto , Idoso , Colesterol/sangue , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Absorção Intestinal/fisiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Medição de Risco , Fatores de Risco , Adulto JovemRESUMO
AIM: Recent studies indicate that type 2 diabetes is associated with an increased secretion of both hepatic and intestinal lipoproteins, leading to the accumulation of atherogenic triglyceride (TG)-rich lipoproteins. Sitagliptin is a selective inhibitor of dipeptidyl peptidase-4 that has been shown to reduce fasting and postprandial glucose levels in patients with type 2 diabetes presumably through incretin hormone-mediated improvements in islet function. The objective of the present study is to examine the effects of treatment with sitagliptin on postprandial lipid and incretin hormone levels as well as glucose homeostasis in patients with type 2 diabetes. METHODS: Thirty-six subjects with type 2 diabetes (30 men/6 postmenopausal women with a mean age of 58.1 ± 6.4 years and a body mass index of 30.7 ± 4.9 kg/m(2) ) were recruited in this double-blind cross-over study using sitagliptin 100 mg/day or placebo for a 6-week period each, with a 4-week washout period between the two phases. At the end of each phase of treatment, patients underwent an oral lipid tolerance test providing 35 g of fat per m(2) of body surface area and blood samples were taken over an 8-h period. RESULTS: Sitagliptin therapy significantly decreased the postprandial area under the curves (AUCs) for plasma apolipoprotein (apo)B (-5.1%, p = 0.002), apoB-48 (-7.8%, p = 0.03), TG (-9.4%, p = 0.006), very low-density lipoprotein (VLDL)-cholesterol (-9.3%, p = 0.001), free fatty acids (FFAs) (-7.6%, p = 0.005) and glucose (-9.7%, p < 0.0001). Furthermore, the postprandial AUCs for plasma intact glucagon-like peptide-1 (+67.8%, p < 0.0001) and glucose-dependent insulinotropic polypeptide (+67.3%, p < 0.0001) were significantly increased following treatment with sitagliptin, whereas the AUC for plasma glucagon was reduced by -9.7% (p = 0.001) with no significant changes in the AUCs for plasma insulin and C-peptide. Sitagliptin therapy also improved homeostasis model assessment (HOMA) index for insulin resistance (-14.6%, p = 0.01) and ß-cell function (+32.3%, p = 0.007). CONCLUSIONS: Treatment with sitagliptin for 6 weeks reduced postprandial plasma levels of TG-rich lipoproteins of both intestinal and hepatic origin, most likely by increasing incretin hormone levels, reducing circulating plasma FFA concentrations and improving insulin sensitivity and ß-cell function.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Hipoglicemiantes/uso terapêutico , Lipoproteínas/metabolismo , Período Pós-Prandial/efeitos dos fármacos , Pirazinas/uso terapêutico , Triazóis/uso terapêutico , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial/fisiologia , Fosfato de Sitagliptina , Resultado do TratamentoRESUMO
BACKGROUND AND AIMS: No study has yet examined how weight loss modifies the impact of the Mediterranean diet (MedDiet) on cardiovascular risk factors in men with the metabolic syndrome (MetS). The objective of the study was to assess the efficacy of MedDiet, with and without weight loss, to modify the cardiometabolic risk profile of male patients with MetS. METHODS AND RESULTS: Twenty-six men aged between 24 and 62 years with the MetS consumed a North American control diet for 5 weeks followed by a 5-week MedDiet, both under weight-maintaining conditions. Participants then underwent a 20-week weight loss period, after which they consumed the MedDiet for five weeks under weight stable conditions. Body weight was reduced by 10.2% ± 2.9% after the weight loss period (p < 0.001). All foods were provided to participants during the weight stable phases of the study. The MedDiet in the absence of weight loss decreased total plasma cholesterol (C) (-7.1%), LDL-C (-9.3%) and the total/HDL-C ratio (-6.5%) compared to the control diet (all p < 0.04). The MedDiet combined with weight loss led to reductions in systolic blood pressure (-4.7%), diastolic blood pressure (-7.7%), triglycerides (-18.2%), ApoB (-10.7%), fasting glucose (-4.2%) and insulin (-29.9%) compared to the control diet (all p < 0.001). CONCLUSION: The MedDiet in the absence of weight loss leads to significant changes in plasma cholesterol concentrations but has little effects on other cardiometabolic risk factors associated with the MetS in men.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Dieta Mediterrânea , Redução de Peso/efeitos dos fármacos , Adulto , Antropometria , Apolipoproteínas B/sangue , Glicemia/análise , Pressão Sanguínea/efeitos dos fármacos , Restrição Calórica , Doenças Cardiovasculares/etiologia , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Humanos , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Cooperação do Paciente , Medição de Risco , Fatores de Risco , Triglicerídeos , Adulto JovemRESUMO
Physiological correlates of seasonal growth patterns were measured in lake trout Salvelinus namaycush from two populations with contrasting diets (zooplankton-dominated diet in Louisa Lake; fish-dominated diet in Opeongo Lake). Fish in Opeongo Lake grew faster and were in better condition than fish in Louisa Lake. The most prominent biochemical difference between populations was higher citrate synthase (CS) and cytochrome c oxidase activity in the white muscle of fish from Opeongo Lake, indicating greater sustained swimming activity in this lake. In contrast, lactate dehydrogenase (LDH) activity in white muscle, an indicator of capacity for burst swimming, was similar between lakes. Nucleoside diphosphate kinase (NDPK) activity in white muscle, an indicator of protein synthesis, was higher in Opeongo Lake than in Louisa Lake but only in the autumn. In both lakes, protein concentration and therefore nutritional status increased as the growing season progressed from spring to summer to autumn. Biochemical indicators of growth and activity showed similar seasonal patterns in the two lakes with the spring characterized by high NDPK, high CS and high LDH activities (i.e. high levels of protein synthesis in association with high aerobic and anaerobic activities). These results suggest high foraging effort and allocation to growth early in the growing season in both lakes.
Assuntos
Cadeia Alimentar , Fibras Musculares de Contração Rápida/enzimologia , Plâncton , Estações do Ano , Truta/crescimento & desenvolvimento , Animais , Biomarcadores/metabolismo , Dieta , Feminino , Água Doce , Modelos Lineares , Masculino , Ontário , Truta/metabolismoRESUMO
The energetic and physiological status of parental smallmouth bass Micropterus dolomieu was investigated across the majority of their latitudinal range at the onset and near the end of care. Variables such as tissue lipid stores, plasma indicators of nutritional status and chronic stress and white muscle were used to define energetic and physiological status. Results showed that northern males (48 degrees N) were larger and heavier than mid-northern (44 degrees N) and southern (36 degrees N) latitude males. For a given body size, northern males had greater whole-body lipid across the parental care period and tended to feed more (based on gut contents) than mid-northern and southern latitude conspecifics. Indicators of nutritional status were also highest in northern males. Conversely, the southern males exhibited the greatest capacity for biosynthesis across the entire parental care period as indicated by the highest level of nucleoside diphosphate kinase activities. Collectively, these finding suggest that the energetic costs and physiological consequences of care vary across latitudes, providing some of the first mechanistic evidence of how environmental conditions can influence both the ecological and physiological costs of reproduction for wild animals during parental care. The data also suggest that lake-specific processes that can vary independently of latitude may be important, necessitating additional research on fish reproductive physiology across landscapes.
Assuntos
Bass/fisiologia , Comportamento Animal/fisiologia , Metabolismo Energético/fisiologia , Animais , Proteínas Sanguíneas/análise , Colesterol/sangue , Enzimas/metabolismo , Conteúdo Gastrointestinal/química , Masculino , Sódio/sangue , Triglicerídeos/sangueRESUMO
BACKGROUND: The issue of mild to moderate ischemic mitral regurgitation (IMR) is controversial after conventional surgery, and has not been specifically studied after off-pump coronary artery bypass graft (OPCAB) surgery. OBJECTIVE: To review the influence of mild or moderate IMR on longterm survival and recurrent cardiac events after OPCAB surgery. METHODS: A total of 1000 consecutive and systematic OPCAB patients who underwent operations between September 1996 and March 2004 were prospectively followed. Sixty-seven patients (6.7%) had mild to moderate IMR at the time of surgery. Operative mortality, actuarial survival and major adverse cardiac event-free survival were studied to assess the effect of IMR. RESULTS: The mean (+/- SD) follow-up period was 66+/-22 months and was completed in 97% of the cohort. IMR patients were older (P<0.001), and had lower ejection fractions (P<0.001) and more comorbidities. More female patients presented with IMR (P=0.002). Operative mortality (P=0.25) and prevalence of perioperative myocardial infarction (P=0.25) were comparable for both groups. Eight-year survival was decreased in IMR patients (P<0.001), but after adjusting for risk factors in the Cox regression model, mild to moderate IMR was not found to be a significant risk factor of long-term mortality (P=0.42). Major adverse cardiac event-free survival at eight years was significantly lower in IMR patients (P<0.001) and, more specifically, in patients with 2+ IMR. After adjusting for risk factors, IMR remained a significant cause of poor outcome (hazard ratio 2.09), especially for recurrent congestive heart failure and myocardial infarction. CONCLUSIONS: OPCAB patients with preoperative mild or moderate IMR had a higher prevalence of preoperative risk factors than those without IMR. They had comparable perioperative mortality and morbidity but, over the long term, were found to be at risk for recurrent cardiac events.