RESUMO
Peracarida (e.g. woodlice and side-swimmers) are, together with their sister-group Eucarida (e.g. krill and decapods), the most speciose group of modern crustaceans, suggested to have appeared as early as the Ordovician. While eucarids' incursion onto land consists of mainly freshwater and littoral grounds, some peracarids have evolved fully terrestrial ground-crawling ecologies, inhabiting even our gardens in temperate regions (e.g. pillbugs and sowbugs). Their fossil record extends back to the Carboniferous and consists mainly of marine occurrences. Here, we provide a complete re-analysis of a fossil arthropod-Oxyuropoda-reported in 1908 from the Late Devonian floodplains of Ireland, and left with unresolved systematic affinities despite a century of attempts at identification. Known from a single specimen preserved in two dimensions, we analysed its anatomy using digital microscopy and multispectral macroimaging to enhance the contrast of morphological structures. The new anatomical characters and completeness of Oxyuropoda, together with a phylogenetic analysis with representatives of all major Eumalacostraca groups, indicate that Oxyuropoda is a crown peracarid, part of a clade including amphipods and isopods. As such, Oxyuropoda is the oldest known species Peracarida, and provides evidence that derived peracarids had an incursion into freshwater and terrestrial environments as early as the Famennian, more than 360 Ma.
Assuntos
Isópodes , Animais , Fósseis , Água Doce , Irlanda , FilogeniaRESUMO
In some Scandinavian countries, the United Kingdom and the United States, there is evidence of a dramatic decline in adolescent emotional wellbeing, particularly among girls. It is not clear to what extent this decline can be generalised to other high-income countries. This study examines trends over time (2005-2009-2013-2017) in adolescent wellbeing in the Netherlands, a country where young people have consistently reported one of the highest levels of wellbeing across Europe. It also assesses parallel changes over time in perceived schoolwork pressure, parent-adolescent communication, and bullying victimization. Data were derived from four waves of the nationally representative, cross-sectional Dutch Health Behaviour in School-aged Children study (N = 21,901; 49% girls; Mage = 13.78, SD = 1.25). Trends in emotional wellbeing (i.e., emotional symptoms, psychosomatic complaints, life satisfaction) were assessed by means of multiple regression analyses with survey year as a predictor, controlling for background variables. Emotional wellbeing slightly declined among adolescent boys and girls between 2009 and 2013. A substantial increase in perceived schoolwork pressure was associated with this decline in emotional wellbeing. Improved parent-adolescent communication and a decline in bullying victimization may explain why emotional wellbeing remained stable between 2013 and 2017, in spite of a further increase in schoolwork pressure. Associations between emotional wellbeing on the one hand and perceived schoolwork pressure, parent-adolescent communication, and bullying victimization on the other were stronger for girls than for boys. Overall, although increasing schoolwork pressure may be one of the drivers of declining emotional wellbeing in adolescents, in the Netherlands this negative trend was buffered by increasing support by parents and peers. Cross-national research into this topic is warranted to examine the extent to which these findings can be generalised to other high-income countries.
Assuntos
Bullying , Vítimas de Crime , Adolescente , Criança , Estudos Transversais , Europa (Continente) , Feminino , Humanos , Masculino , Países Baixos , Pais , Países Escandinavos e Nórdicos , Reino Unido , Estados UnidosRESUMO
BACKGROUND/OBJECTIVES: Mutations in the Tubby gene (TUB) cause late-onset obesity and insulin resistance in mice and syndromic obesity in humans. Although TUB gene function has not yet been fully elucidated, studies in rodents indicate that TUB is involved in the hypothalamic pathways regulating food intake and adiposity. Aside from the function in central nervous system, TUB has also been implicated in energy metabolism in adipose tissue in rodents. We aimed to determine the expression and distribution patterns of TUB in man as well as its potential association with obesity. SUBJECTS/METHODS: In situ hybridization was used to localize the hypothalamic regions and cells expressing TUB mRNA. Using RT-PCR, we determined the mRNA expression level of the two TUB gene alternative splicing isoforms, the short and the long transcript variants, in the hypothalami of 12 obese and 12 normal-weight subjects, and in biopsies from visceral (VAT) and subcutaneous (SAT) adipose tissues from 53 severely obese and 24 non-obese control subjects, and correlated TUB expression with parameters of obesity and metabolic health. RESULTS: Expression of both TUB transcripts was detected in the hypothalamus, whereas only the short TUB isoform was found in both VAT and SAT. TUB mRNA was detected in several hypothalamic regions involved in body weight regulation, including the nucleus basalis of Meynert and the paraventricular, supraoptic and tuberomammillary nuclei. We found no difference in the hypothalamic TUB expression between obese and control groups, whereas the level of TUB mRNA was significantly lower in adipose tissue of obese subjects as compared to controls. Also, TUB expression was negatively correlated with indices of body weight and obesity in a fat-depot-specific manner. CONCLUSIONS: Our results indicate high expression of TUB in the hypothalamus, especially in areas involved in body weight regulation, and the correlation between TUB expression in adipose tissue and obesity. These findings suggest a role for TUB in human obesity.
Assuntos
Tecido Adiposo/metabolismo , Hipotálamo/metabolismo , Obesidade , Proteínas , Proteínas Adaptadoras de Transdução de Sinal , Frequência do Gene/genética , Humanos , Metaboloma/genética , Metaboloma/fisiologia , Metabolômica , Obesidade/epidemiologia , Obesidade/genética , Obesidade/metabolismo , Proteínas/análise , Proteínas/genética , Proteínas/metabolismoRESUMO
This paper provides an overview of "Improving Design, Evaluation and Analysis of early drug development Studies" (IDEAS), a European Commission-funded network bringing together leading academic institutions and small- to large-sized pharmaceutical companies to train a cohort of graduate-level medical statisticians. The network is composed of a diverse mix of public and private sector partners spread across Europe, which will host 14 early-stage researchers for 36 months. IDEAS training activities are composed of a well-rounded mixture of specialist methodological components and generic transferable skills. Particular attention is paid to fostering collaborations between researchers and supervisors, which span academia and the private sector. Within this paper, we review existing medical statistics programmes (MSc and PhD) and highlight the training they provide on skills relevant to drug development. Motivated by this review and our experiences with the IDEAS project, we propose a concept for a joint, harmonised European PhD programme to train statisticians in quantitative methods for drug development.
Assuntos
Desenvolvimento de Medicamentos/educação , Educação de Pós-Graduação/métodos , Estatística como Assunto/educação , Comportamento Cooperativo , Currículo , Desenvolvimento de Medicamentos/estatística & dados numéricos , Indústria Farmacêutica/organização & administração , Europa (Continente) , Humanos , Setor Privado , Setor Público , Pesquisa/organização & administraçãoRESUMO
Heavy veal calves (4-6 mo old) often develop problems with insulin sensitivity. This could lead to metabolic disorders and impaired animal growth performance. Studies in various animal species have shown that the supplementation of short-chain fructo-oligosaccharides (scFOS) can improve insulin sensitivity. We therefore studied the effects of scFOS supplementation on insulin sensitivity in heavy veal calves. Forty male Holstein-Friesian calves (BW = 190 ± 2.9 kg; age = 162 ± 1.4 d at the start of the trial) were fed either a control milk replacer (MR) diet or a diet in which one-third of the lactose was replaced by glucose, fructose, or glycerol for 10 wk prior to the start of the trial. At the start of the trial, calves were subjected to a frequently sampled intravenous glucose tolerance test to assess whole-body insulin sensitivity (muscle and hepatic insulin sensitivity). Calves within each dietary treatment group were ranked based on their insulin sensitivity value. Half of the calves received scFOS (12 mg/kg of BW) with the MR for 6 wk (supplementation was equally distributed over the insulin sensitivity range). Subsequently, a second frequently sampled intravenous glucose tolerance test was conducted to assess the effect of scFOS. In addition, fasting plasma levels of glucose, insulin, triglycerides, and cholesterol were determined to calculate the quantitative insulin sensitivity check index and triglyceride:high-density lipoprotein cholesterol ratio (fasting indicators of insulin sensitivity). Whole-body insulin sensitivity was low at the start of the trial and remained low in all groups [1.0 ± 0.1 and 0.8 ± 0.1 (mU/L)-1 · min-1 on average, respectively]. Supplementation of scFOS did not improve insulin sensitivity in any of the treatment groups. The quantitative insulin sensitivity check index and the triglyceride:high-density lipoprotein cholesterol ratio also did not differ between scFOS and non-scFOS calves and averaged 0.326 ± 0.003 and 0.088 ± 0.004, respectively, at the end of the trial. We conclude that scFOS supplementation does not improve insulin sensitivity in heavy veal calves regardless of the carbohydrate composition of the MR. This is in contrast to other animals (e.g., dogs and horses), where scFOS supplementation did improve insulin sensitivity. The absence of an effect of scFOS might be related to the dosage or to metabolic differences between ruminants and nonruminants. Increasing evidence indicates that dietary interventions in veal calves have little or no effect on insulin sensitivity, possibly because of low levels of insulin sensitivity.
Assuntos
Bovinos/crescimento & desenvolvimento , Carboidratos da Dieta/administração & dosagem , Resistência à Insulina/fisiologia , Oligossacarídeos/farmacologia , Envelhecimento , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/metabolismo , Dieta/veterinária , Carboidratos da Dieta/classificação , Frutose/metabolismo , Glucose/metabolismo , Teste de Tolerância a Glucose , Insulina/sangue , Lactose/metabolismo , Masculino , Oligossacarídeos/administração & dosagem , Oligossacarídeos/metabolismo , Triglicerídeos/metabolismoRESUMO
BACKGROUND: Schizophrenia is associated with lower intelligence and poor educational performance relative to the general population. This is, to a lesser degree, also found in first-degree relatives of schizophrenia patients. It is unclear whether bipolar disorder I (BD-I) patients and their relatives have similar lower intellectual and educational performance as that observed in schizophrenia. METHOD: This cross-sectional study investigated intelligence and educational performance in two outpatient samples [494 BD-I patients, 952 schizophrenia spectrum (SCZ) patients], 2231 relatives of BD-I and SCZ patients, 1104 healthy controls and 100 control siblings. Mixed-effects and regression models were used to compare groups on intelligence and educational performance. RESULTS: BD-I patients were more likely to have completed the highest level of education (odds ratio 1.88, 95% confidence interval 1.66-2.70) despite having a lower IQ compared to controls (ß = -9.09, S.E. = 1.27, p < 0.001). In contrast, SCZ patients showed both a lower IQ (ß = -15.31, S.E. = 0.86, p < 0.001) and lower educational levels compared to controls. Siblings of both patient groups had significantly lower IQ than control siblings, but did not differ on educational performance. IQ scores did not differ between BD-I parents and SCZ parents, but BD-I parents had completed higher educational levels. CONCLUSIONS: Although BD-I patients had a lower IQ than controls, they were more likely to have completed the highest level of education. This contrasts with SCZ patients, who showed both intellectual and educational deficits compared to healthy controls. Since relatives of BD-I patients did not demonstrate superior educational performance, our data suggest that high educational performance may be a distinctive feature of bipolar disorder patients.
Assuntos
Logro , Transtorno Bipolar/psicologia , Cognição , Família/psicologia , Inteligência , Esquizofrenia , Psicologia do Esquizofrênico , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Escolaridade , Feminino , Humanos , Testes de Inteligência , Masculino , Pessoa de Meia-Idade , Razão de Chances , Adulto JovemRESUMO
In veal calves, the major portion of digestible energy intake originates from milk replacer (MR), with lactose and fat contributing approximately 45 and 35%, respectively. In veal calves older than 4 mo, prolonged high intakes of MR may lead to problems with glucose homeostasis and insulin sensitivity, ultimately resulting in sustained insulin resistance, hepatic steatosis, and impaired animal performance. The contribution of each of the dietary energy sources (lactose and fat) to deteriorated glucose homeostasis and insulin resistance is currently unknown. Therefore, an experiment was designed to compare the effects of a high-lactose and a high-fat MR on glucose homeostasis and insulin sensitivity in veal calves. Sixteen male Holstein-Friesian calves (120±2.8kg of BW) were assigned to either a high-lactose (HL) or a high-fat (HF) MR for 13 consecutive weeks. After at least 7 wk of adaptation, whole-body insulin sensitivity and insulin secretion were assessed by euglycemic-hyperinsulinemic and hyperglycemic clamps, respectively. Postprandial blood samples were collected to assess glucose, insulin, and triglyceride responses to feeding, and 24-h urine was collected to quantify urinary glucose excretion. At the end of the trial, liver and muscle biopsies were taken to assess triglyceride contents in these tissues. Long-term exposure of calves to HF or HL MR did not affect whole-body insulin sensitivity (averaging 4.2±0.5×10-2 [(mg/kgâmin)/(µU/mL)]) and insulin secretion. Responses to feeding were greater for plasma glucose and tended to be greater for plasma insulin in HL calves than in HF calves. Urinary glucose excretion was substantially higher in HL calves (75±13g/d) than in HF calves (21±6g/d). Muscle triglyceride content was not affected by treatment and averaged 4.5±0.6g/kg, but liver triglyceride content was higher in HF calves (16.4±0.9g/kg) than in HL calves (11.2±0.7g/kg), indicating increased hepatic fat accumulation. We conclude that increasing the contribution of fat to the digestible energy intake from the MR from 20 to 50%, at the expense of lactose does not affect whole-body insulin sensitivity and insulin secretion in calves. However, a high-lactose MR increases postprandial glucose and insulin responses, whereas a high-fat MR increases fat accumulation in liver but not muscle.
Assuntos
Bovinos/fisiologia , Gorduras na Dieta/metabolismo , Resistência à Insulina , Lactose/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Fígado/metabolismo , MasculinoRESUMO
Calf milk replacer (MR) contains 40 to 50% lactose. Lactose strongly fluctuates in price and alternatives are desired. Also, problems with glucose homeostasis and insulin sensitivity (i.e., high incidence of hyperglycemia and hyperinsulinemia) have been described for heavy veal calves (body weight >100 kg). Replacement of lactose by other dietary substrates can be economically attractive, and may also positively (or negatively) affect the risk of developing problems with glucose metabolism. An experiment was designed to study the effects of replacing one third of the dietary lactose by glucose, fructose, or glycerol on glucose homeostasis and insulin sensitivity in veal calves. Forty male Holstein-Friesian (body weight=114 ± 2.4 kg; age=97 ± 1.4 d) calves were fed an MR containing 462 g of lactose/kg (CON), or an MR in which 150 g of lactose/kg of MR was replaced by glucose (GLU), fructose (FRU), or glycerol (GLY). During the first 10d of the trial, all calves received CON. The CON group remained on this diet and the other groups received their experimental diets for a period of 8 wk. Measurements were conducted during the first (baseline) and last week of the trial. A frequently sampled intravenous glucose tolerance test was performed to assess insulin sensitivity and 24 h of urine was collected to measure glucose excretion. During the last week of the trial, a bolus of 1.5 g of [U-(13)C] substrates was added to their respective meals and plasma glucose, insulin, and (13)C-glucose responses were measured. Insulin sensitivity was low at the start of the trial and remained low [1.2 ± 0.1 and 1.0 ± 0.1 (mU/L)(-1) × min(-1)], and no treatment effect was noted. Glucose excretion was low at the start of the trial (3.4 ± 1.0 g/d), but increased in CON and GLU calves (26.9 ± 3.9 and 43.0 ± 10.6g/d) but not in FRU and GLY calves. Postprandial glucose was higher in GLU, lower in FRU, and similar in GLY compared with CON calves. Postprandial insulin was lower in FRU and GLY and similar in GLU compared with CON calves. Postprandial (13)C-glucose increased substantially in FRU and GLY calves, indicating that calves are able to partially convert these substrates to glucose. We concluded that replacing one third of lactose in MR by glucose, fructose, or glycerol in MR differentially influences postprandial glucose homeostasis but does not affect insulin sensitivity in veal calves.
Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Bovinos/metabolismo , Dieta/veterinária , Leite/química , Ração Animal/normas , Animais , Peso Corporal/fisiologia , Frutose/metabolismo , Glucose/metabolismo , Teste de Tolerância a Glucose , Glicerol/metabolismo , Insulina/sangue , Resistência à Insulina/fisiologia , Lactose/metabolismo , Masculino , Leite/metabolismo , Período Pós-PrandialRESUMO
Veal calves at the age of 4 to 6 mo often experience problems with glucose homeostasis, as indicated by postprandial hyperglycemia, hyperinsulinemia, and insulin resistance. It is not clear to what extent the ontogenetic development of calves or the feeding strategy [e.g., prolonged milk replacer (MR) feeding] contribute to this pathology. The objective of this study was therefore to analyze effects of MR feeding, weaning, and supplementation of short-chain fructo-oligosaccharides (FOS) on the development of glucose homeostasis and insulin sensitivity in calves during the first 3 mo of life. Thirty male Holstein-Friesian calves (18±0.7 d of age) were assigned to 1 of 3 dietary treatments: the control (CON) group received MR only, the FOS group received MR with the addition of short-chain FOS, and the solid feed (SF) group was progressively weaned to SF. The CON and FOS calves received an amount of MR, which gradually increased (from 400 to 1,400 g/d) during the 71-d trial period. For the SF calves, the amount of MR increased from 400 to 850 g/d at d 30, and then gradually decreased, until completely weaned to only SF at d 63. The change in whole body insulin sensitivity was assessed by intravenous glucose tolerance tests. Milk tolerance tests were performed twice to assess changes in postprandial blood glucose, insulin, and nonesterified fatty acid responses. Whole-body insulin sensitivity was high at the start (16.7±1.6×10(-4) [µU/mL](-1)), but decreased with age to 4.2±0.6×10(-4) [µU/mL](-1) at the end of the trial. The decrease in insulin sensitivity was most pronounced (~70%) between d 8 and 29 of the trial. Dietary treatments did not affect the decrease in insulin sensitivity. For CON and FOS calves, the postprandial insulin response was 3-fold higher at the end of the trial than at the start, whereas the glucose response remained similar. The SF calves, however, showed pronounced hyperglycemia and hyperinsulinemia at the end of the trial, although weaning did not affect insulin sensitivity. We conclude that whole body insulin sensitivity decreases by 75% in calves during the first 3 mo of life. Weaning or supplementation of short-chain FOS does not affect this age-related decline in insulin sensitivity. Glucose homeostasis is not affected by supplementation of short-chain FOS in young calves, whereas postprandial responses of glucose and insulin to a MR meal strongly increase after weaning.
Assuntos
Glicemia/metabolismo , Bovinos/fisiologia , Dieta/veterinária , Resistência à Insulina , Oligossacarídeos/metabolismo , Desmame , Fatores Etários , Ração Animal/análise , Animais , Suplementos Nutricionais/análise , Homeostase , Masculino , Oligossacarídeos/administração & dosagemRESUMO
BACKGROUND: The risk of developing bipolar disorder (BD) has been linked to structural brain abnormalities. The degree to which genes and environment influence the association of BD with cortical surface area remains to be elucidated. In this twin study, genetic and environmental contributions to the association between liability to develop BD and surface area, thickness and volume of the cortex were examined. METHOD: The study cohort included 44 affected monozygotic (nine concordant, 12 discordant) and dizygotic (four concordant, 19 discordant) twin pairs, and seven twins from incomplete discordant monozygotic and dizygotic discordant twin pairs. In addition, 37 monozygotic and 24 dizygotic healthy control twin pairs, and six twins from incomplete monozygotic and dizygotic control pairs were included. RESULTS: Genetic liability to develop BD was associated with a larger cortical surface in limbic and parietal regions, and a thicker cortex in central and parietal regions. Environmental factors related to BD were associated with larger medial frontal, parietal and limbic, and smaller orbitofrontal surfaces. Furthermore, thinner frontal, limbic and occipital cortex, and larger frontal and parietal, and smaller orbitofrontal volumes were also associated with environmental factors related to BD. CONCLUSIONS: Our results suggest that unique environmental factors play a prominent role in driving the associations between liability to develop BD and cortical measures, particularly those involving cortical thickness. Further evaluation of their influence on the surface and thickness of the cortical mantle is recommended. In addition, cortical volume appeared to be primarily dependent on surface and not thickness.
Assuntos
Transtorno Bipolar/genética , Transtorno Bipolar/fisiopatologia , Córtex Cerebelar/fisiopatologia , Interação Gene-Ambiente , Adolescente , Adulto , Algoritmos , Estudos de Coortes , Feminino , Predisposição Genética para Doença/genética , Humanos , Entrevistas como Assunto , Sistema Límbico/fisiopatologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Neuroimagem , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Adulto JovemRESUMO
CONTEXT: History helps us to better understand the particulars of the form and functions of institutions. In this paper we present the case study of the evolution of health care financing in the Netherlands over the past 150 years, through the lens of incremental institutional change. METHODS: Our historical and political analysis is based on a review of secondary literature as well as relevant policy documents, parliamentary debates and archival material. We use the conceptual framework of incremental institutional change (i.e. layering, conversion, drift and displacement) for our analysis. FINDINGS: The constitutional program of the mid-nineteenth century laid down the foundations of a 'private initiative first, government last'-approach to health care financing in the Netherlands. Over the course of 150 years this led to the evolution of a complex layered system of financial arrangements consisting of direct public funding, national, social and private health insurance with complex interdependencies. This was not a conscious strategy, but a result of the fact that the central government in the Netherlands preferred to tackle specific problems in health care financing with very specific measures, so as not to intrude on the trade of civil society and commercial business in health care. CONCLUSIONS: Regulatory authority and statist power in and over health care financing is not something that was created through dramatic reform in the Netherlands, but came about through many decades of small, incremental, yet accumulating changes. This provides a case study for further analysis of incremental versus rapid change in health care systems internationally.
Assuntos
Atenção à Saúde , Seguro Saúde , Governo , Reforma dos Serviços de Saúde , Política de Saúde , Financiamento da Assistência à Saúde , Humanos , Países BaixosRESUMO
PURPOSE: To explore the combined effect of trends in older people on their future healthcare utilisation. METHODS: A Delphi study consisting of two rounds was conducted. The heterogeneous expert panel (nâ¯=â¯16) in the field of elderly care rated the effect of combinations of trends in the Netherlands on the use of seven healthcare services: i.e. informal, home, general practitioner, acute, specialist, nursing home and mental health care. The percentage and direction of the overall consensus, for the different health services, and for three main trends were analysed. RESULTS: Experts reached consensus in 57 of 92 ratings (62%). Taking into account the interaction between trends, they expected an extra increase for informal, home, and general practitioner care, but no additional effect of interaction for specialist and acute care. Combinations that included trends leading to less support were expected to lead to an extra increase in utilisation. CONCLUSIONS: Experts expect that interaction between trends will lead to an extra increase in the use of general practitioner, home, and informal care. This increase is mainly the result of interaction with trends leading to less support for older persons. The present results show the need to take the effect of interaction into account when designing new health policy and in research on future healthcare utilisation.
Assuntos
Envelhecimento , Serviços de Saúde/tendências , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Técnica Delphi , Feminino , Humanos , Vida Independente/tendências , Masculino , Pessoa de Meia-Idade , Países Baixos , Dinâmica PopulacionalRESUMO
Disease-related malnutrition (DRM) is a frequent clinical problem, characterized by loss of lean body mass and decreased function, including muscle function and immunocompetence. In DRM, nutritional intervention is necessary, but it has not consistently been shown to be sufficient. Other factors, for example, physical activity and hormonal or metabolic influencers of the internal milieu, are also important in the treatment of DRM. A prerequisite for successful treatment of DRM is the positive balance between anabolism and catabolism. The aim of this review was to approach DRM using this paradigm of anabolic competence, for conceptual and practical reasons. Anabolic competence is defined as "that state which optimally supports protein synthesis and lean body mass, global aspects of muscle and organ function, and immune response." Anabolic competence and interdisciplinary, multimodality interventions create a practical foundation to approach DRM in a proactive comprehensive way. Here, we describe the paradigm of anabolic competence, and its operationalization by measuring factors related to anabolic competence and suited for clinical management of patients with DRM.
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Desnutrição/metabolismo , Desnutrição/terapia , Terapia Nutricional/métodos , Anabolizantes/uso terapêutico , Índice de Massa Corporal , Terapia Combinada , Exercício Físico , Humanos , Desnutrição/etiologiaRESUMO
Lactose maldigestion and intolerance affect a large part of the world population. The underlying factors of lactose intolerance are not fully understood. In this review, the role of colonic metabolism is discussed, i.e. fermentation of lactose by the colonic microbiota, colonic processing of the fermentation metabolites and how these processes would play a role in the pathophysiology of lactose intolerance. We suggest that the balance between the removal and production rate of osmotic-active components (lactose, and intermediate metabolites, e.g. lactate, succinate, etc.) in the colon is a key factor in the development of symptoms. The involvement of the colon may provide the basis for designing new targeted strategies for dietary and clinical management of lactose intolerance.
Assuntos
Colo/metabolismo , Intolerância à Lactose/metabolismo , Lactose/metabolismo , Bifidobacterium/metabolismo , Colo/microbiologia , Fermentação , Humanos , Lactatos/metabolismo , Intolerância à Lactose/etiologia , Intolerância à Lactose/terapiaRESUMO
BACKGROUND: Information about the extent of carbohydrate digestion and fermentation is critical to our ability to explore the metabolic effects of carbohydrate fermentation in vivo. We used cooked (13)C-labelled barley kernels, which are rich in indigestible carbohydrates, to develop a method which makes it possible to distinguish between and to assess carbohydrate digestion and fermentation. MATERIALS AND METHODS: Seventeen volunteers ingested 86 g (dry weight) of cooked naturally (13)C enriched barley kernels after an overnight fast. (13)CO(2) and H(2) in breath samples were measured every half hour for 12 h. The data of (13)CO(2) in breath before the start of the fermentation were used to fit the curve representing the digestion phase. The difference between the area under curve (AUC) of the fitted digestion curve and the AUC of the observed curve was regarded to represent the fermentation part. Different approaches were applied to determine the proportion of the (13)C-dose available for digestion and fermentation. RESULTS: Four hours after intake of barley, H(2)-excretion in breath started to rise. Within 12 h, 24-48% of the (13)C-dose was recovered as (13)CO(2), of which 18-19% was derived from colonic fermentation and the rest from digestion. By extrapolating the curve to baseline, it was estimated that eventually 24-25% of the total available (13)C in barley would be derived from colon fermentation. CONCLUSION: Curve fitting, using (13)CO(2)- and H(2)-breath data, is a feasible and non-invasive method to assess carbohydrate digestion and fermentation after consumption of (13)C enriched starchy food.
Assuntos
Dióxido de Carbono/análise , Carboidratos da Dieta/metabolismo , Hidrogênio/análise , Amido/metabolismo , Adulto , Área Sob a Curva , Testes Respiratórios , Isótopos de Carbono , Carboidratos da Dieta/administração & dosagem , Digestão , Feminino , Fermentação , Hordeum , Humanos , MasculinoRESUMO
AIMS: Colonic metabolism of lactose may play a role in lactose intolerance. We investigated whether a 2-week supplementation of Bifidobacterium longum (in capsules) and a yogurt enriched with Bifidobacterium animalis could modify the composition and metabolic activities of the colonic microbiota in 11 Chinese lactose-intolerant subjects. METHODS AND RESULTS: The numbers of total cells, total bacteria and the Eubacterium rectale/Clostridium coccoides group in faeces as measured with fluorescent in situ hybridization and the faecal beta-galactosidase activity increased significantly during supplementation. The number of Bifidobacterium showed a tendency to increase during and after supplementation. With PCR-denaturing gradient gel electrophoresis, in subjects in which B. animalis and B. longum were not detected before supplementation, both strains were present in faeces during supplementation, but disappeared after supplementation. The degree of lactose digestion in the small intestine and the oro-caecal transit time were not different before and after supplementation, whereas symptom scores after lactose challenge decreased after supplementation. CONCLUSIONS: The results suggest that supplementation modifies the amount and metabolic activities of the colonic microbiota and alleviates symptoms in lactose-intolerant subjects. The changes in the colonic microbiota might be among the factors modified by the supplementation which lead to the alleviation of lactose intolerance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides evidence for the possibility of managing lactose intolerance with dietary lactose (yogurt) and probiotics via modulating the colonic microbiota.
Assuntos
Bifidobacterium , Colo/microbiologia , Intolerância à Lactose/dietoterapia , Probióticos , Iogurte , Adulto , Biomarcadores/análise , China , Clostridium/fisiologia , Contagem de Colônia Microbiana , Suplementos Nutricionais , Eletroforese em Gel de Poliacrilamida/métodos , Eubacterium/fisiologia , Fezes/química , Fezes/microbiologia , Feminino , Seguimentos , Humanos , Hibridização in Situ Fluorescente , Lactobacillus , Lactose , Intolerância à Lactose/microbiologia , Teste de Tolerância a Lactose , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Streptococcus thermophilus , beta-Galactosidase/análiseRESUMO
BACKGROUND: Diet as one aspect of lifestyle is thought to be one of the modifiable risk factors for the development of type 2 diabetes mellitus (T2DM). Information is needed as to which components of the diet could be protective for this disease. OBJECTIVES: To asses the effects of whole-grain foods for the prevention of T2DM. SEARCH STRATEGY: We searched CENTRAL, MEDLINE, EMBASE, CINAHL and AMED. SELECTION CRITERIA: We selected cohort studies with a minimum duration of five years that assessed the association between intake of whole-grain foods or cereal fibre and incidence of T2DM. Randomised controlled trials lasting at least six weeks were selected that assessed the effect of a diet rich in whole-grain foods compared to a diet rich in refined grain foods on T2DM and its major risk factors. DATA COLLECTION AND ANALYSIS: Two authors independently selected the studies, assessed study quality and extracted data. Data of studies were not pooled because of methodological diversity. MAIN RESULTS: One randomised controlled trial and eleven prospective cohort studies were identified. The randomised controlled trial, which was of low methodological quality, reported the change in insulin sensitivity in 12 obese hyperinsulinemic participants after six-week long interventions. Intake of whole grain foods resulted in a slight improvement of insulin sensitivity and no adverse effects. Patient satisfaction, health related quality of life, total mortality and morbidity was not reported. Four of the eleven cohort studies measured cereal fibre intake, three studies whole grain intake and two studies both. Two studies measured the change in whole grain food intake and one of them also change in cereal fibre intake. The incidence of T2DM was assessed in nine studies and changes in weight gain in two studies. The prospective studies consistently showed a reduced risk for high intake of whole grain foods (27% to 30%) or cereal fibre (28% to 37%) on the development of T2DM. AUTHORS' CONCLUSIONS: The evidence from only prospective cohort trials is considered to be too weak to be able to draw a definite conclusion about the preventive effect of whole grain foods on the development of T2DM. Properly designed long-term randomised controlled trials are needed. To facilitate this, further mechanistic research should focus on finding a set of relevant intermediate endpoints for T2DM and on identifying genetic subgroups of the population at risk that are most susceptible to dietary intervention.
Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Grão Comestível , Fibras na Dieta/administração & dosagem , Grão Comestível/efeitos adversos , Humanos , Resistência à InsulinaRESUMO
Transport systems involved in uptake and biliary secretion of bile salts have been extensively studied in rat liver; however, little is known about these systems in the human liver. In this study, we investigated taurocholate (TC) transport in canalicular and basolateral plasma membrane vesicles isolated from 15 human livers (donor age 6-64 yr). ATP stimulated the uptake of TC into both canalicular and basolateral human liver plasma membrane vesicles (cLPM and blLPM, respectively). Considerable interindividual variations in the transport velocity were observed in the different membrane preparations used: 9.0 +/- 1.3 (mean +/- SEM, n = 17; range 1.6-18.0) and 9.3 +/- 2.0 (range 1.1-29.8) pmol TC.mg protein-1.min-1 at 1.0 microM TC for cLPM and blLPM, respectively. TC transport was temperature sensitive and showed saturation kinetics with a high affinity for TC (Km 4.2 +/- 0.7 microM and 3.7 +/- 0.5 microM for cLPM and blLPM, respectively). Transport was dependent on the ATP concentration and saturable (Km 0.25 +/- 0.03 mM, n = 3). Neither nitrate, which reduces membrane potential, nor the protonophore FCCP strongly inhibited ATP-dependent TC transport, indicating that membrane potential and proton gradient are not involved in this process. TC transport was significantly inhibited by the classical anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonate (250 microM) and the glutathione conjugate S-(2,4-dinitrophenyl)glutathione (100 microM). In conclusion, high affinity ATP-dependent TC transport is present in human liver at both the canalicular and the basolateral sides of the hepatocyte.
Assuntos
Trifosfato de Adenosina/metabolismo , Fígado/metabolismo , Ácido Taurocólico/metabolismo , Adulto , Fatores Etários , Transporte Biológico Ativo/efeitos dos fármacos , Membrana Celular/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Técnicas In Vitro , Cinética , Masculino , Pessoa de Meia-IdadeRESUMO
Biliary secretion of 3 alpha-sulfated bile acids has been studied in Wistar rats with an autosomal recessive defect in the hepatic transport of bilirubin. Liver function, established by measurement of various enzymes in plasma, by enzyme histochemical methods, and by electron microscopy, appeared to be normal in these rats. Serum levels of unconjugated, monoglucuronidated, and diglucuronidated bilirubin were 0.62, 1.62, and 6.16 mumol/liter, respectively, compared with 0.17, 0.08, and 0.02 mumol/liter in control rats. Biliary bilirubin secretion was strongly reduced in the mutant animals: 0.21 +/- 0.03 vs. 0.39 +/- 0.03 nmol/min per 100 g body wt in control rats. Despite normal biliary bile acid output, bile flow was markedly impaired in the mutant animals, due to a 53% reduction of the bile acid-independent fraction of bile flow. The transport maximum for biliary secretion of dibromosulphthalein (DBSP) was also drastically reduced (-53%). Biliary secretion of intravenously administered trace amounts of the 3 alpha-sulfate esters of 14C-labeled taurocholic acid (-14%), taurochenodeoxycholic acid (-39%), taurolithocholic acid (-73%), and glycolithocholic acid (-91%) was impaired in the jaundiced rats compared with controls, in contrast to the biliary secretion of the unsulfated parent compounds. Hepatic uptake of sulfated glycolithocholic acid was not affected in the jaundiced animals. Preadministration of DBSP (15 mumol/100 g body wt) to normal Wistar rats significantly impaired the biliary secretion of sulfated glycolithocholic acid, but did not affect taurocholic acid secretion. We conclude that separate transport systems in the rat liver exist for biliary secretion of sulfated and unsulfated bile acids; the sulfates probably share secretory pathways with the organic anions bilirubin and DBSP. The described genetic defect in hepatic transport function is associated with a reduced capacity to secrete sulfated bile acids into bile; this becomes more pronounced with a decreasing number of hydroxyl groups on the sulfated bile acid's molecule.