ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718588

出版商:Routledge    

年代:1996

数据来源: Taylor

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718589

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

Glutamine is a nonessential amino acid which can be synthesized from glutamate and glutamic acid by glutamine synthetase. It is the preferred fuel for the rat small intestine. Animal studies have suggested both glutamine-supplemented parenteral nutrition and enteral diets may prevent bacterial translocation. This effect is thought to be modulated via the preservation and augmentation of small bowel villus morphology, intestinal permeability and intestinal immune function. The existing data are less compelling in humans. It remains unclear what, if any, intestinal deficits actually occur in humans during provision of exclusive parental nutrition. Furthermore, the clinical significance of these changes is largely undefined in humans. The existing data on the use of parenteral and enteral glutamine for the purpose of preserving intestinal morphology and function, and the prevention of bacterial translocation in humans are reviewed. Pertinent animal data are also described.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718590

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

The placenta plays a key role in the nutrition of the fetus. It mediates the active transport of nutrients and metabolic wastes across the barrier separating maternal and fetal compartments, as well as modifying the composition of some nutrients through its own metabolic activity. The function of the placenta is essential to the growth of a healthy fetus; it is becoming apparent that the activities of the placenta are in turn modulated by signals originating from the fetus. Communication between placenta and fetus is especially critical in intrauterine growth retardation. The importance of the interaction of factors like insulin-like growth factor and epidermal growth factor with their receptors is becoming increasingly clear.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718591

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

This review examines possible relationships between anorexia, dietary intake and central nervous system histaminergic activity. The hypothesis being reviewed is that one component of normal or pathophysiological neuroregulation of food intake involves histaminergic activity in the central nervous system, as influenced by concentrations and bioperiodicities of histamine and/or histamine receptors. Changes in concentrations of receptors are gender specific. Low protein quality or quantity diets elevate both central histamine and histamine receptors (H1) in rats while significantly decreasing their food intake. When injected with histaminergic antagonists, rats fed low protein diets increase food intake and have improved efficiency of weight gain. This review supports a dual hypotheses: central histaminergic activity is involved in the regulation of food intake, but food intake patterns (including dietary composition or energy content) can modify central histaminergic activity. This review also suggests that modified histamine and/or H1 receptor concentrations are potential mechanisms for elevated central histaminergic activity in food intake-related pathophysiological states. Thus, dietary interventions (clinically- or self-imposed) which modify food intake or diet composition have the potential of affecting the histaminergic system. Also, drugs with antihistaminergic properties have the potential of affecting food intake/weight gain patterns by interfering with normal neurochemical signals.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718592

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

The objective of this study was a) to determine the plasma and red cell thiamin levels in geriatric outpatients and b) to evaluate, using the rat model, the sensitivity of plasma thiamin concentration as an indicator of nutritional status for this vitamin.Thirty geriatric outpatients were evaluated for their plasma and erythrocyte thiamin levels.Plasma and red cell thiamin levels were determined by a microbiologic assay using kloeckera apiculata. Sprague-Dawley rats were fed a thiamin deficient diet. Blood samples were obtained on specified days and the plasma and erythrocyte thiamin levels determined.Forty-three percent of the subjects studied had plasma thiamin levels below 2 SD of the mean of the younger-age group (20-60 yr) while 57% had a plasma thiamin below 10 ng/ml (the lower reference range of the younger age group). Twenty-seven percent were found to have red cell thiamin levels below 2 SD of the mean of the younger-age group, while 33% had red cell thiamin levels below 138 ng/ml (the lower reference range of the younger-age group). The rat study indicated that plasma thiamin concentration is a sensitive indicator of the nutritional status for this vitamin.About 50% of geriatric outpatients in this study had low plasma thiamin levels. The long-term effect of a low plasma thiamin level on cognitive functions remains to be investigated.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718593

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

Describe plasma amino acid concentrations and total urinary amino acid excretion in subjects from an elderly female population.Fasting plasma samples, complete 24-hour urine samples, and 3-day diet records were obtained from 96 healthy postmenopausal women in one study and fasting plasma samples were obtained from an additional 44 subjects in 3 separate studies. In one study, nonfasting plasma samples were also collected. The subjects ranged in age from 49 to 80 years of age. Samples were obtained to allow the evaluation of the effects of fasting vs. nonfasting, normal vs. Alzheimers subjects, and level of protein intake effects.Heparinized plasma samples were deproteinized with a 5-sulfosalicylic acid solution and centrifuged at 14,900×g. Deproteinized plasma and urine samples were analyzed for free amino acids on a Beckman System 6300 analyzer using a postcolumn reaction with ninhydrin to quantitate the amino acids.It is concluded that: 1) From fasting plasma samples, 1 or 2 sampling days are sufficient to establish a characteristic concentration for most plasma amino acids. 2) Fasting amino acid concentrations do not reflect levels of dietary protein intake when dietary amino acid composition is similar. Shifts in fasting amino acid concentrations would be more indicative of changes in relative amounts of amino acids absorbed rather than level of dietary protein per se. 3) Totals of fasting plasma concentrations of arginine, citrulline and ornithine were relatively constant, but fluctuations occurred in the ratio of ornithine to arginine in the different populations; and 4) Patients with Alzheimers disease exhibited altered plasma ornithine and arginine concentrations relative to active or sedentary controls.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718594

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

This study was designed to compare the metabolizable energy of two starch sources, standard cornstarch and high amylose cornstarch.Diets containing 70% amylose (AM) or 70% amylopectin (AP) cornstarches were fed to 10 control and 14 hyperinsulinemic men for 14 weeks. During the last 4 weeks of each period, subjects were fed a controlled diet containing 34% of total energy from fat, 15% from protein and 51% from carbohydrate (55% of carbohydrate provided AM or AP). Duplicate food and all urine and feces were collected during the second week of the controlled diets for energy, nitrogen, fiber and starch determinations. Metabolizable energy (ME) was calculated as [energy intake minus (fecal plus urinary energy excretion)].Total fiber uncorrected for resistant starch was 35.2 g and 48.8 g in the AP and AM diets, respectively. The AM diet contained an average of 29.7 g resistant starch (16% of total starch) while the AP diet averaged 0.8 g (less than 0.01%). ME was not significantly different between the AM and AP diets nor between the control and hyperinsulinemic subjects. Fecal energy and nitrogen was significantly higher after the AM compared to AP diet. Based on energy intake and fecal excretion from all subjects, the partial digestible energy value for the resistant starch averaged 11.7 kJ/g resistant starch which was 67.3% of the energy of standard cornstarch. Control and hyperinsulinemic subjects differed in their ability to digest resistant starch, averaging 81.8% and 53.2, respectively. The hyperinsulinemic, but not control, subjects had significantly higher breath hydrogen expirations (LS means, p>0.05) in the fasting, 1-5 hours and 7 hour collections after consuming the AM when compared to the AP tolerance meal.The type of starch consumed in the diet did not statistically affect metabolizable energy. Based on ME and breath hydrogen expiration, amylose and the resistant starch from amylose appears to be utilized as an energy source. Resistant starch averaged 2.8 kcal/g for all 24 subjects but only 2.2 kcal/g in the hyperinsulinemic subjects.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718595

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

A survey was carried out in 1988-89 among French Canadians in Montreal, to provide data on food habits, dietary intakes and sociodemographic factors.Interviewer-administered questionnaires and 7-day food records (7D-FR) were used to gather data.Some 1,450 individuals (in 845 families) were studied. Complete 7D-FR and sociodemographic data were obtained from 182 children aged 5-18 (44.8% males), and 614 adults aged 19 and over (40.1% males). Most adult respondents greatly surpassed their age-sex specific Canadian Recommended Nutrient Intakes (RNIs), except for low mean energy intakes in women aged 75 years and over (on average, 1477 kcal), and marginally lower than recommended mean calcium consumption, again in the oldest age group (particularly men). Protein furnished 16 to 17% of energy, relative fat intake varied from 34% of energy among the oldest subjects to 38% in 25 to 49 year old women (overall average, 36%). Only 15.3% of respondents consumed

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718596

出版商:Routledge    

年代:1996

数据来源: Taylor

摘要:

A representative sample of French Canadian Montrealers was surveyed to compile data on food habits, nutrient intakes and sociodemographic characteristics, using interviewer-administered questionnaires and 7-day food records (7D-FR).Complete 7D-FR and sociodemographic data were obtained from 614 adults aged 19 and over (40.1% males), and 182 children aged 5 to 18 (44.8% males). Average heights and weights of children were at the 50th percentile for both sexes and all age groups. Nutrient intakes surpassed most of the age- and sex-specific 1990 Canadian Recommended Nutrient Intakes (RNIs). Energy intakes were 83% to 98% of the RNIs, with 16-18 year old adolescent girls having systematically lower energy consumption. Calcium was most frequently found below the 66% age-sex specific RNI cut-off. On average, protein comprised 16% of energy, fat 36-37%, and carbohydrates 48-49%, for males and females, respectively. Simple sugars comprised 16-19% of energy among boys, and 16-20% among girls, fluctuating with age. Only a small proportion of respondents (15.4%) had low relative total fat and saturated fat intakes (ranging from 30-34%, and 10-12% of energy, respectively); no differences in mean nutrient levels were found between low, medium or higher fat consumers. Among those with inadequate intakes, 26% lived in one lower middle income sector of Montreal; however, no clear pattern emerged linking dietary adequacy and socioeconomic factors.While Montreal youngsters consume generally adequate diets, sufficient quantities of calcium-furnishing foods must be eaten, particularly by adolescent girls. Surveillance of children's food and nutrient intakes will contribute to the reduction of chronic disease by providing data for effective health care planning.

ISSN:0731-5724    

DOI:10.1080/07315724.1996.10718597

出版商:Routledge    

年代:1996

数据来源: Taylor