ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThis review introduces physiologists and clinical investigators to an ever-widening array of nuclear magnetic resonance applications. In particular, it highlights a multiple tracer technique that provides a comprehensive picture of metabolic processes within human liver.Recent findingsMagnetic resonance spectroscopy is an important technique for studying metabolism in the brain, liver, heart and skeletal muscle. One fundamental advantage is that the studies are inherently noninvasive, so time-dependent information can be obtained. For example,31P nuclear magnetic resonance investigations indicate that greater maximal oxygen uptake and oxidative capacity in trained athletes can be partially attributed to adaptations enhancing the rates at which phosphocreatine and inorganic phosphate recover during stress. In-vivo measurements of lipids and glycogen by1H and13C spectroscopy demonstrate that accumulation of intracellular lipids and impaired rates of glycogen synthesis contribute to insulin resistance and type 2 diabetes mellitus. Similar techniques can be used to analyze blood and urine samples obtained during administration of2H or13C tracers to yield information that cannot be easily obtained by mass spectrometry. Additional information available from nuclear magnetic resonance yields a comprehensive picture of liver metabolic pathways from a single clinical study.SummaryA variety of magnetic resonance spectroscopy protocols have been validated and exploited for clinical studies, but relatively few investigators are comfortable with technical aspects of these protocols and utilize them for clinical research. Increased interaction between spectroscopists and other investigators is needed if the potential of nuclear magnetic resonance for studying in-vivo metabolism is to be fully realized.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewOur goal is to explain how2H2O, a stable isotope of water, can be used to quantify metabolic fluxin vivo. Although2H2O was originally used more than 65 years ago, recent reports have described new applications. Investigators have also refined the original work. We discuss those points, emphasizing factors that should be considered when interpreting data. As our goal is to discuss why2H2O is a novel tracer for studying metabolism, we do not comment on the interpretation(s) of physiological data.Recent findingsIt is clear that2H2O can now be used to address questions related to carbohydrate, lipid, protein and DNA synthesis. A particular advantage of using2H2O is that investigators can study metabolism in free-living individuals. Using this novel tracer method, it is thus possible to elucidate new, highly relevant, knowledge regarding health and disease.SummaryAs the use of2H2O requires few assumptions, the application of this tracer should yield sound information regarding the regulation of biochemical reactionsin vivo.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of the reviewThis is a review on recent studies regarding methodological aspects of assessment of energy expenditure in children and adolescents.Recent findingsA variety of methods used for assessment of different components of energy expenditure has been validated and used in children and adolescents. Reference values derived from representative groups of healthy children and adolescents are now available. Variations in the different components of energy expenditure and physical activity have been proposed to be associated with weight gain, and the prevalence of overweight and obesity. However, recent cross-sectional and longitudinal data in children and adolescents do not provide strong evidence for this idea. In contrast, hypermetabolism, which is frequently seen in critically ill children, may contribute to their tissue catabolism. In this case beta blockade seems to be a way to increase ‘metabolic economy’ and thus to reduce tissue catabolism. In chronically ill children and adolescents (e.g. patients with cystic fibrosis and sickle cell anemia) energy expenditure is also frequently increased and group specific algorithms are needed for predicting energy expenditure when measurement facilities are not available.SummaryMethods for assessment of the different components of energy expenditure have been validated in children and adolescents. The combined use of these methods together with detailed analyses of body composition is recommended for future studies. In patients with acute or chronic illness measurements of energy expenditure are necessary if disease-specific algorithms are not available.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewMalnutrition is highly prevalent in hospitalized patients. Despite this, it is not routinely assessed in most hospitals worldwide. One of the reasons that might explain this fact is that there is no gold-standard nutritional assessment tool, and much has been written advocating this or that technique. The main topic of this review is discussion of the advantages and disadvantages of each of the available tools.Recent findingsSeveral studies have recently reinforced the relationship between poor nutritional status and higher incidences of complications, mortality, length of hospital stay and costs. Therefore, it is of the utmost importance to be able to diagnose malnutrition early.SummaryThe evaluation of nutritional status is a broad topic that encompasses several clinical variables. In order to be ideal, the method should be able to predict patient outcome, should be able to be performed by most care-givers, should be inexpensive, and should not be time-consuming. Unfortunately, most nutritional assessment instruments were published with insufficient details regarding their intended use and method of derivation, and with an inadequate assessment of their effectiveness. Therefore, health professionals should be critical when defining which instrument should be adopted by an institution, and several factors should be taken into consideration.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewEvaluation of an athlete's diet is important in both clinical practice and research. The main purpose of this review is to provide health professionals with guidance regarding the special issues that are likely to be encountered when assessing the dietary intake of sportspersons.Recent findingsA number of methods may be used for the dietary assessment of individuals and/or groups of athletes, including retrospective (diet recall, food-frequency questionnaire, and diet history) and prospective (diet record, duplicate portion) techniques. A 3-4-day estimated diet record is the most widely used approach, but collection of single or multiple diet recalls is also common. Care must be taken, however, to ensure that days of diet monitoring accurately reflect usual food consumption during the period of interest. Under-reporting of habitual energy intake is widespread among athletes, and its magnitude should be carefully addressed when interpreting the results of dietary assessment. Other issues, specifically related to sportspersons, that are often neglected include adequacy of standard portion sizes, frequency of snacking, fluid intake, supplement use, weight-control practices, and seasonality of sport activities and food consumption.SummaryThere are subtle methodological differences in the dietary assessment of athletes and non-athletes, which, when taken into consideration, may substantially increase the quality of intake data and optimise the outcome of dietary intervention.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThe bioelectrical impedance analysis method is a non-invasive, rapid accurate and practical method for assessing body composition. During last decade evidence has been gathered that supports the use of this method to monitor hydration status. This review critically examines different approaches and applications of segmental bioelectrical impedance analysis in the healthy and clinical situations.Recent findingsSegmental bioelectrical impedance analysis may be useful to assess appendicular lean body mass, to estimate muscle volume and to investigate possible relationships between muscle size and strength in a limited segment of the limb. The method may become a tool for the bedside detection of fluid accumulation in critical care.SummaryThis is a review of segmental bioelectrical impedance. The preponderance of the published applications of bioelectrical impedance analysis focused on applications in a healthy population and in the field indicate the validity of the methods. A short description of the set-up of the segmental method is also given. This review discusses the application of segmental bioelectrical impedance analysis in children in different ethnic populations, in clinical situations. We also examine the application of the method to assessing body composition, and monitoring rapid changes in internal fluid balance in the field of haemodialysis and during surgery.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThe obesity epidemic, the increasing occurrence of adult diseases in childhood, and the growing awareness of a connection between adult diseases and the diet of children and adolescents have led to increased interest in what our youth are eating. Designing an instrument to evaluate adolescents' eating habits requires addressing not only the typical requirements for a diet assessment tool but also the unique concerns of the adolescent population. We reviewed current dietary instruments for adolescents.Recent findingsNew nutrient assessment methods fall into one of two groups: instruments limited to a specific nutrient/food or those designed for a specific population. The new tools range from Food Intake Recording Software System, a computer program to assist individuals under 10 years of age in reporting their diets, to short food-frequency questionnaires specifically designed to assess fruits and vegetables or fat. Another new instrument uses picture cards to evaluate the entire diet of low-income, overweight African-Americans. The Youth Adolescent Questionnaire, although not a new tool, has been evaluated in new populations (multi-ethnic, multi-income, and multi-education) and with doubly labeled water.SummaryA limited number of dietary assessment instruments that are specifically designed for adolescents have been found to be reproducible and validated. There is a demand for a short, easily administered, inexpensive, accurate instrument that can be used in a broad range of adolescent subpopulations. Future tools will need to meet these criteria and evaluate the ‘new’ nutrients, foods, and other factors that lead our youth to eat the foods they do.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewDiarrhoea is a common and worldwide problem, accounting for significant morbidity and mortality, especially in children. This paper reviews recent advances in the field of nutritional intervention for the prevention and treatment of diarrhoeal diseases.Recent findingsIn the developing countries, the incidence of diarrhoeal diseases remains unchanged, whereas in industrialized areas a decrease has been reported. In acute diarrhoea, oral rehydration therapy is the treatment of first choice. Newer oral rehydration solutions with amylase-resistant starch or partially hydrolysed guar gum have been tested and found to be useful. Promising new data on supplementation with zinc in acute diarrhoea were published last year. The use of prebiotics and probiotics in the prevention and the treatment of diarrhoea is still controversial. However, new data and meta-analyses with probiotics are available, showing benefits in the treatment of acute diarrhoea as a co-treatment with oral rehydration. The same benefits were found to apply to antibiotic-associated diarrhoea syndromes. The co-administration of probiotics to patients receiving antibiotics seems to be a promising approach for reducing the incidence of antibiotic-associated diarrhoea. New evidence suggests that fibre reduces diarrhoea associated with enteral tube feeding. Furthermore, a new probiotic mixture (VSL-3, viable lyophilized bacteria of 4 strains ofLactobacillus, 3 strains ofBifidobacteriumand 1 strain ofStreptococcus thermophilus(VSL Pharmaceuticals, Inc,. Ft. Lauderdale, FL. USA)) was of benefit in the treatment of bacterial overgrowth and in the prevention of diarrhoea after pelvic radiation treatment.SummaryOral rehydration is still the first line of treatment for acute diarrhoea. Zinc supplements have been shown to have a beneficial effect on acute diarrhoea in children. Probiotics and fibre have proved to be useful in the prevention and treatment of several diarrhoea syndromes. Because of the small numbers of patients and shortcomings in design and analysis, additional large placebo-controlled trials of the effects of fibre and probiotics, or a combination of both, in diarrhoea syndromes are needed.

ISSN:1363-1950    

出版商:OVID    

年代:2003

数据来源: OVID