Identification of pro- and mature brain-derived neurotrophic factor in human saliva.

OBJECTIVE: Growth factors, including brain-derived neurotrophic factor (BDNF), are polypeptides that are involved in the maintenance, survival, and death of central and peripheral cells. Numerous growth factors have been identified in saliva and are thought to promote wound healing and maintenance of the oral epithelium. The aim of this study was to determine if BDNF is also found in human saliva. METHODS: Whole, unstimulated saliva samples (n = 30) were analyzed by SDS-PAGE and Western blot using an anti-human BDNF antibody. Proteolytic cleavage products were similarly assessed following the incubation of pooled saliva with N-glycanase F and plasmin. Subjects were also genotyped for the BDNF Val66Met single nucleotide polymorphism (SNP). RESULTS: These experiments revealed the presence of immunoreactive bands at 14, 32 and 34 kDa, corresponding to mature (mBDNF) and proBDNF, as well as a truncated pro-form at 24 kDa. Not every sample contained all forms of BDNF. Treatment with N-glycanase and plasmin reduced the size of the higher molecular weight bands, confirming the glycosylated pro-form of BDNF. mBDNF was detected significantly less often in subjects with the Val66Met SNP, compared to those without the polymorphism (chi(2) = 4.05; P < 0.05). CONCLUSIONS: While the function of salivary BDNF still requires elucidation, these findings suggest that it may be possible to use saliva in lieu of blood in future studies of BDNF and the Val66Met polymorphism.

Healthy eating in Ukraine: attitudes, barriers and information sources.

OBJECTIVE: To identify the major perceived influences on food choice, to examine the use of and trust in information sources concerning healthy eating, and to assess attitudes towards and barriers to adopting healthy eating practices in a post-USSR country (Ukraine). DESIGN: A survey of an urban adult population. The questions were adopted from the Pan-European Union (EU) Survey of Consumer Attitudes to Food, Nutrition and Health (1995-1996). SETTING: Lviv city, Ukraine. SUBJECTS: The survey included 296 adults (84 males, 212 females) aged 18-55 years; they were primarily college students and subjects with tertiary education--the groups most likely to be both interested in healthy eating and affected by current socioeconomic downturns. RESULTS: The major factors in food choice were: 'quality/freshness' (cited by 80%), 'price' (58%) and 'taste' (47%); only 34% cited 'trying to eat healthily'. More older people cited 'price' than 'quality/freshness', and men were more likely than women to cite 'taste'. Sources of healthy eating information included: 'relatives/friends' (cited by 65%, trusted by 85%) and health professionals (trusted by 92%, but used by only 35%); while advertising was the least trusted source (cited by 28%). Fifty-three per cent of respondents considered their diet to be healthy enough without further changes; 50% thought of the nutritional aspects of the food they ate; fewer women than men considered their diet healthy, and more women than men thought about nutrition. Barriers to healthy eating included: 'cost' (cited by 65%), 'lack of time' (55%), 'self-control' (54%), 'selection influences' (41%), 'lack of knowledge' (32%), 'unpleasant foods' and 'resistance to change' (both 30%). CONCLUSIONS: Strategies to encourage healthy eating in this population should involve word-of-mouth nutrition education concerning low-cost healthy alternatives.

A multivariate analysis of psychological factors related to body mass index and eating preoccupation in female college students.

Using a composite questionnaire, we measured the degree to which preoccupation with eating and body mass index (BMI) are related to a series of psychological measures in a sample of female college students. Eating preoccupation was measured using a set of questions designed to be free of affective content. Thirty volunteers filled out the questionnaire; their height and weight were measured under standard conditions. Correlations showed that BMI was positively related to the variables Depression and Emotional Response to Environmental Stimuli, while Eating Preoccupation was most closely related to Anxiety. Principal components analysis revealed two factors, one containing measures of positive emotionality, and one containing Eating Preoccupation and measures of negative emotionality, with BMI loaded on both components. These factors reflect the relationship of BMI to measures of both positive and negative emotionality. Positive emotionality may be a reflection of activation of a neurobehavioral system, the behavioral facilitation system, while negative emotionality may be a reflection of activation of the behavioral inhibition system. The overweight women in this study appeared to have high levels of activation of one or both systems, while the underweight women appeared to have low activation of both systems. Approaches to the study of obesity in women should take into account the fact that positive emotionality, as well as negative emotions such as depression and anxiety, may be related to BMI, and that eating preoccupation appears to be a subset of overall anxiety.

Nutritional support for the patient with renal failure.

Renal failure presents patients and caregivers alike with numerous dilemmas in nutritional management. Too much protein, phosphate, or electrolytes, and the patient's renal failure becomes more symptomatic; too little of these nutrients and the patient is at great risk of developing fluid and electrolyte imbalances and of becoming protein-calorie malnourished. Dietary manipulation and often vigorous nutritional intervention (i.e., parenteral nutrition) are a must for these patients' survival. The nurse needs to understand the rationales behind nutritional care choices made by the physician and dietitian, and to be able to convey these rationales to the patient. The nurse also needs to be aware that the patient will use food, eating, and diet as a focus for acting out anxiety, fear, hopelessness, and anger. The nurse should also realize that these emotions are due, in part, to the metabolic derangements induced by the renal disease itself.

Impact of asymptomatic congenital cytomegalovirus infection on size at birth and gestational duration.

Cytomegalovirus (CMV) is the most common viral agent causing congenital infection in humans, affecting 0.2 to 2.4% of all live births. Symptomatic congenital CMV infection has previously been shown to cause low birth weight and prematurity. Whether or not asymptomatic congenital CMV infection, which represents the majority of cases (90 to 95%), affects intrauterine growth or gestational duration is unknown. Using a population of 146 infants with asymptomatic congenital CMV infection and 1419 controls from two socioeconomically diverse populations (biracial low income and white mid- to upper income), determinants of body size (birth weight and crown-heel length) were investigated using multiple regression techniques. We found that congenital infection following the transmission of maternal primary and "unknown" CMV infection resulted in a significant mean birth weight deficit of 163 g (P less than 0.04) for the low income term infants (blacks and whites), but not in the mid- to upper income white infants. Newborns with congenital infection following the transmission of maternal reactivated (recurrent) CMV infection were significantly shorter by a mean of 1 cm (P less than 0.03) than controls, a finding that was consistent regardless of socioeconomic status or race.

Nutritional support of bone marrow transplant recipients: a prospective, randomized clinical trial comparing total parenteral nutrition to an enteral feeding program.

Although standard supportive care for bone marrow transplant (BMT) recipients includes total parenteral nutrition (TPN), it has not been shown that this is the most appropriate method of nutritional support. To determine whether current BMT recipients require TPN during the early recovery period, we conducted a prospective, randomized clinical trial comparing TPN and an individualized enteral feeding program (counseling, high protein snacks and/or tube feeding). Nutritional assessment included measurement of serum proteins, anthropometry, and body composition analysis. For the latter, total body water and extracellular fluid were measured by standard radioisotope dilution techniques and used to quantitate body cell mass and body fat plus extracellular solids (FAT + ECS). In 27 TPN patients, body composition 28 days after BMT, expressed as a percentage of baseline, was body cell mass, 100%, extracellular fluid, 108%, FAT + ECS, 108%, and in 30 enteral feeding program patients, was body cell mass, 93%, extracellular fluid, 104%, and FAT + ECS, 94%. Only the difference in FAT + ECS was statistically significant (p less than 0.01). Compared to the enteral feeding program, TPN was associated with more days of diuretic use, more frequent hyperglycemia, and more frequent catheter removal (prompted by catheter-related complications), but less frequent hypomagnesemia. There were no significant differences in the rate of hematopoietic recovery, length of hospitalization, or survival, but nutrition-related costs were 2.3 times greater in the TPN group. We conclude that TPN is not clearly superior to individualized enteral feeding and recommend that TPN be reserved for BMT patients who demonstrate intolerance to enteral feeding.

Response of mildly to moderately malnourished children to measles vaccination

Nutritional aspects of measles vaccination were examined in 51 Trinidadian children from one to three years of age with no prior history of measles. The subjects were divided into two weight-for-length groups derived from the Havard Standards and included 22 children with a weight-for-length of 90 percent or greater and 29 children with a weight-for-length of less than 90 percent. There were no significant differences in the two groups in general immune function, as assessed by white blood cell counts, immunoglobulin and C3 levels, nor in immune response, as assessed by measles antibody titres and direct migration inhibition of leukocytes to measles antigen following vaccination. All of the subjects seroconverted following vaccination, with titres of 1:40 or above. There were no significant changes in nutritional status in either group following vaccination, other than a small but significant rise in total serum protein levels in the normal group. (AU)

Energy requirements of parenterally fed bone marrow transplant recipients.

To determine the energy intake (kcal/kg/day) necessary to maintain zero nitrogen balance (assuming adequate protein intake) during the first 30 days after transplant, we studied 91 bone marrow transplant recipients. Serial nitrogen balance and concomitant energy and protein intakes were determined prospectively on each patient. Eight-four (92%) of the patients (ages 4-49 yr) had sufficient data for evaluation. For each patient, a simple linear model (nitrogen balance vs energy intake) was used to determine the patient's predicted individual energy requirement during the first 30 posttransplant days (EReq30). Weighted least squares multiple regression was used to determine the effect on EReq30 of such variables as age and sex. Energy requirements were significantly (p less than 0.001) greater for children, males, and patients with acute graft-vs-host disease, and when the percent of the total energy intake given by the intravenous route was high. An equation that incorporated these variables was developed to predict the energy requirements for bone marrow transplant recipients during their first 30 posttransplant days. Although individual energy requirements vary, this equation is a useful guide for initial energy prescriptions.

Nutritional assessment by isotope dilution analysis of body composition.

The three components of body mass, body cell mass (BCM), extracellular fluid (ECF), and fat + extracellular solids (ECS: bone, tendon, etc) can be quantified using established isotope dilution techniques. With these techniques, total body water (TBW) and ECF are measured using 3H2O and 82Bromine, respectively, as tracers. BCM is calculated from intracellular fluid (ICF) where ICF = TBW - ECF. Fat + ECS is estimated as: body weight - (BCM + ECF). TBW and ECF can be determined by either of two calculation methods, one requiring several timed plasma samples (extrapolation method) and one requiring a single plasma sample and a 4-h urine collection (urine-corrected method). The comparability of the two calculation methods was evaluated in 20 studies in 12 bone marrow transplant recipients. We found that for determination of TBW and ECF there was a very strong linear relationship (r2 greater than 0.98) between the calculation methods. Further comparisons (by t test, 2-sided) indicated that for the determination of ECF, the methods were not significantly (p greater than 0.90) different; however, TBW determined by the urine-corrected method was slightly (0.1 to 6%), but significantly (p less than 0.01) greater than that determined by the extrapolation method. Therefore, relative to the extrapolation method, the urine-corrected method "over-estimates" BCM and "under-estimates" fat + ECS since determination of these compartment sizes depends on measurement of TBW. We currently use serial isotope dilution studies to monitor the body composition changes of patients receiving therapeutic nutritional support.

The effect of a human plasma thymic factor on human peripheral blood mononuclear cell subpopulations.

Human plasma thymic factor in vitro (human "facteur thymique sérique," or FTS) (at concentrations between 0.25 and 0.25 X 10(5) pg/ml) significantly increased "avid" E-rosette formation by human peripheral blood mononuclear cells (PBMC). It also increased the percentage of OKT8+ cells but did not affect the percentages of OKT3+, OKT4+, OKT11+, OKIa1+, or OKM+ cells. In the low-density immature PBMC, FTS increased both total and avid E-rosette formation, while increasing the percentages of OKT3+ and OKT8+ cells and decreasing the percentage of OKT4+ cells. Theophylline decreased E-rosette formation and the percentages of OKT3+ and OKT4+ among PBMC, and increased the percentages of OKT3+ and OKT4+ among the low-density cells. Human FTS may be capable of inducing maturation of immature PBMC into E-rosette-forming OKT3+8+ cells, while increasing the percentage of mature cells which may be doubly labeled OKT4+8+. The function of such doubly labeled cells remains to be determined. Human FTS may act by increasing intracellular cAMP in immature cells, but probably has a different mode of action in mature cells.

Isolation and assay of a human plasma factor affecting human thymus-derived lymphocytes.

An amino acid-containing factor has been isolated from a dialysate of defibrinated human plasma using Sephadex G-25 and Sephadex CM-25 column chromatography. This factor is capable of enhancing "avid" E-rosette formation by normal human lymphocytes, where avid E-rosettes are defined as lymphocytes binding 10 or more sheep red cells. This factor is effective at concentrations as low as 10(-12) g/ml. It resembles the porcine and murine "facteur thymique sérique" (e.g. J.-F. Bach, M. Dardenne, J.-M. Pleau, and J. Rosa, Nature (London) 266, 55, 1977) in its elution characteristics, its capacity to enhance avid E-rosette formation and, tentatively, its amino acid composition.

Direct migration inhibition with measles antigen effect of measles vaccination

The direct migration inhibition (DMI) assay with measles antigen was performed on leukocytes from 24 Trinidadian children both before and after measles vaccination. The children had no clinical history or serological evidence of measles before vaccination. After vaccination, the measles (HI) antibody titer (geometric mean titer) rose to 1:128. Despite the lack of prior measles exposure, migration inhibition to the antigen was high before vaccination and did not significantly differ from migration inhibition after vaccination. This finding suggests that reactivity to measles in the DMI assay is probably nonspecific and does not depend on prior exposure to measles. (AU)