Importance of zinc in the elderly: the ZENITH study.

The elderly are at nutritional risk as a result of multiple physiological, social, psychological, and economic factors. Physiological functions naturally decline with age, which may influence absorption and metabolism. Social and economic conditions can adversely affect dietary choices and eating patterns. However, at the same time, the nutrient needs of the elderly for certain nutrient (such as vitamins, minerals, proteins) is higher than for younger adults. This article reviews the importance of zinc (Zn) in elderly people, particularly for behavioural and mental function, micronutrient status, immune and antioxidant system, and bone metabolism.

Cognitive function in healthy older European adults: the ZENITH study.

OBJECTIVE: Baseline data are reported from a study of the effects of zinc supplementation on cognitive function in older adults as assessed by the CANTAB computerised test battery. DESIGN: This is a multicentre prospective intervention study employing a randomised double-blind design. SETTING: European community-based study. PARTICIPANTS: There are 387 healthy adults aged 55-87 y from centres in France, Italy and Northern Ireland. INTERVENTIONS: Measures of visual memory, working memory and attention were obtained at baseline (prior to supplementation). RESULTS: Younger adults (<70 y) performed significantly better than older adults (>70 y) on all tests, with minimal differences between centres. In addition, men outperformed women on tests of spatial span, pattern recognition memory and reaction times, although these gender differences varied somewhat between centres. CONCLUSIONS: The results are generally consistent with previous age- and gender-related effects on cognitive functioning.

Introduction to the ZENITH study and summary of baseline results.

Zinc is known to be essential for a great number of biochemical activities and physiological and cognitive functions. The objective of Zenith study was to investigate the effects of Zn, as a nutritional supplement, on psychological and behavioural factors and on surrogate markers that are indicative of trends towards better health in order to evaluate the need for dietary recommendations specific to the studied population. We report in this paper the summary of baseline results obtained before Zn supplementation.

Cognitive behavioural therapy (CBT) for carers of patients with Parkinson's disease: a preliminary randomised controlled trial.

OBJECTIVE: Most individuals with Parkinson's disease live in their own homes cared for by a family member. Providing such long term care can be a source of significant stress, with many carers experiencing sleep difficulty, depression, anxiety, loneliness, and other symptoms of psychological strain. Cognitive behavioural therapy (CBT) is one of the most widely used psychological treatments in clinical use today, with applications across the full range of clinical conditions. It has been previously used in the management of other carer groups. The present study sought to evaluate the efficacy of CBT in treating psychological distress in a group of Parkinson's disease carers. METHOD: A total of 30 carers scoring at caseness level on the 28 item General Health Questionnaire (GHQ-28) were randomised to receive either a course of 12-14 sessions of CBT or to a no-treatment control group. RESULTS: Although some change was observed in both groups, significantly greater improvement on the GHQ-28 was observed after three months in the CBT treated group. Similar findings were observed in measures of caregiver strain and subjective burden, with the benefits being maintained over a subsequent three month follow up period. CONCLUSIONS: These results offer preliminary support to the value of a CBT approach in the management of psychological morbidity in Parkinson's disease carers. Further larger scale research is needed in the future to examine the generalisability of the findings to a broader range of carers, assess the longer term impact on outcome in carers and those with Parkinson's disease, and explore how CBT can be best delivered in the most cost effective manner.

Children with hypoalbuminemia on continuous peritoneal dialysis are at risk for technique failure.

BACKGROUND: Few data are available on the clinical significance of hypoalbuminemia [serum albumin (SA) <35 g/L] in children with end-stage renal disease (ESRD) on continuous peritoneal dialysis (CPD). This study was conducted to analyze the prevalence of hypoalbuminemia, its predictive factors, and its clinical impact in these children. METHODS: A retrospective analysis was done of 180 patients on CPD over the last 22 years. Patients were excluded from the study if they were on CPD for less than four months or had nephrotic syndrome. Demographic, clinical, and biochemical variables were studied. Children continued on CPD until they received a transplant or were transferred to an adult unit or to hemodialysis as a result of technique failure. The subjects were divided into two groups based on SA levels at last follow-up. RESULTS: A total of 135 children was included. After a mean duration of CPD of 573 +/- 437 (120 to 2960) days, 54 children (40%) were observed to have hypoalbuminemia. Four patients (2.9%) died, 7 (5.2%) continued on continuous cyclic peritoneal dialysis, and 13 (9.6%) were transferred to an adult unit for continuation of CPD. Ninety-five (70.3%) were transplanted, and 16 (11.8%) were transferred to hemodialysis because of technique failure. Children in group I (N = 54, SA <35 g/L), compared with group II (N = 81, SA > or =35 g/L), were younger at initiation of PD, more likely to have hypoalbuminemia at one month and six months after initiation of PD, and have more episodes of peritonitis. No differences were seen between the groups in gender, modality of CPD, body surface area, initial body mass index, and presence of hypertension or acidosis. The only factors predictive of hypoalbuminemia on follow-up were low SA at one month after PD and recurrent peritonitis using multiple logistic regression analysis. Evaluating the clinical impact of hypoalbuminemia, we observed a higher incidence of failed PD in children who had hypoalbuminemia. CONCLUSION: Low SA at one month after PD and recurrent peritonitis are predictive of hypoalbuminemia in children on CPD, which is associated with an increased incidence of CPD failure.

Introduction.

The scattering of light from spherically shaped particles has been well characterized: it has been derived analytically, modeled computationally and measured experimentally. However, many natural and man-made particle systems are not spherical and these have formed the basis of many recent investigative programs. Modeling the light scattered by non-spherical particle systems using numerical algorithms often is limited by the computational power required to attain a mathematical solution, although increasing capacity and enhanced algorithm sophistication continually extend our capabilities. Experimental measurements can require expensive apparatus and can seldom simultaneously and accurately record all the scattering characteristics. Therefore, computational and experimental approaches often complement one another and enhance our knowledge of the light scattering and the particle systems. Theoreticians and modelers often seek experimental data for verification and to find regions of applicability of their models, and experimentalists may use theoretical results for calibration and performing inversions. Research collaborations between the camps inevitably develop.

Real-time observation of the change in light scattering from droplets with increasing deformity.

Commercial aerodynamic particle sizing instruments generally achieve the desired particle size measurement by accelerating a sample airstream in which the particles are suspended and measuring the velocity acquired by individual particles. The accelerating flow regime can cause liquid droplets to deform and this subsequently introduces errors. In this paper, we present an apparatus that enables droplet deformation to be observed by recording the spatial light scatter intensity. The paper presents experimental data in video format showing the changes that occur in the light scattering from droplets as a function of increasing flow rate/deformation.

Light scattering from deformed droplets and droplets with inclusions. I. Experimental results.

We provide experimental results from the scattering of light by deformed liquid droplets and droplets with inclusions. The characterization of droplet deformation could lead to improved measurement of droplet size as measured by commercial aerodynamic particle-sizing instruments. The characterization of droplets with inclusions can be of importance in some industrial, occupational, and military aerosol monitoring situations. The nozzle assembly from a TSI Aerodynamic Particle Sizer was used to provide the accelerating flow conditions in which experimental data were recorded. A helium-neon laser was employed to generate the light-scattering data, and an externally triggered, pulsed copper vapor laser provided illumination for a droplet imaging system arranged orthogonal to the He-Ne scattering axis. The observed droplet deformation correlates well over a limited acceleration range with theoretical predictions derived from an analytical solution of the Navier-Stokes equation.

Light Scattering from Deformed Droplets and Droplets with Inclusions. II. Theoretical Treatment.

We provide theoretical results from the scattering of light by deformed liquid droplets and droplets with inclusions. With improved instrumentation and computer technologies available, researchers are able to employ two-dimensional angular optical scattering as a tool for analyzing such particle systems and which then could be applied in industrial, occupational, and military aerosol measurement. We present numerically calculated spatial light-scattering data from various droplet morphologies. We describe characteristic features of the theoretical data and compare these with the experimental results.

Efficacy of gastrostomy feeding in infants and older children receiving chronic peritoneal dialysis.

OBJECTIVE: To assess the efficacy of supplemental gastrostomy tube (g-tube) feeding in infants and children receiving chronic peritoneal dialysis (CPD). DESIGN: Retrospective observational study. SETTING: Pediatric nephrology division of tertiary care center. PATIENTS: Fifteen patients undergoing g-tube insertion while receiving CPD were included in the study, and were subdivided, on the basis of age, into the following groups: infants (< or = 2.5 years, n = 8); older children (> 2.5 years, n = 7). MAIN OUTCOME MEASURES: Assessment of the effect of CPD and g-tube feeding on statural growth assessed by height standard deviation score (SDS) and percentage weight-for-height, and measured anthropometric variables including triceps skinfold thickness (TSF), midarm muscle circumference (MAMC), and midarm mean circumference (MAC). Assessment of the effects of CPD and g-tube feeding on measured biochemical variables including total protein, albumin, cholesterol, triglycerides, and high density lipoprotein. RESULTS: No significant change in height SDS was observed; however, the reported continuing decline in height SDS in infants was arrested. Percentage weight-for-height increased significantly in infants at 6 months (p = 0.008) and 12 months (p = 0.006) following initiation of g-tube feeding. An increase was also observed in the older child group, being significant at 12 months (p = 0.031) following g-tube insertion. Increases in all anthropometric variables occurred in the infant group during CPD and post g-tube insertion, significant only for MAMC at 12 months (p = 0.037) post g-tube insertion. In older children little change occurred during CPD, with all variables increasing post g-tube insertion, significant only for MAMC at 6 months (p = 0.02) and 12 months (p = 0.02). An increase in total protein and albumin was noted; however, no significant changes in any biochemical parameters were observed. CONCLUSIONS: Supplemental g-tube feeding facilitates weight gain in infants and older children receiving CPD and arrests the decline in height SDS traditionally observed in infants with end-stage renal disease. No significant alteration was observed in measured biochemical variables, although an increase in total protein and albumin was noted.

Effects of amino acid dialysis compared to dextrose dialysis in children on continuous cycling peritoneal dialysis.

OBJECTIVE: To compare the biochemical and nutritional effects of amino acid dialysis with dextrose dialysis in children receiving continuous cycling peritoneal dialysis (CCPD). DESIGN: A prospective randomized cross-over study. SETTING: Nonhospitalized patients. PATIENTS: Seven children aged 1.8 to 16.0 years (mean 8.1 years) with end-stage renal disease who were receiving CCPD. INTERVENTIONS: Each patient received nighttime automated CCPD of dextrose, plus a single daytime dwell of either amino acid dialysate or dextrose dialysate. After 3 months, subjects crossed over to the alternative regimen for a subsequent 3 months. MAIN OUTCOME MEASURES: Creatinine clearance, ultrafiltration, urea, creatinine, electrolytes, total protein, albumin, fasting plasma amino acids, anthropometrics, total body nitrogen. RESULTS: Amino acid dialysis was comparable to dextrose dialysis for creatinine clearance and ultrafiltration. Plasma urea concentrations were higher during amino acid dialysis. No clinical side effects or worsening of metabolic acidosis was observed. Caloric intake increased and protein intake improved. Appetite and total body nitrogen increased in at least half the children during amino acid dialysis. Total plasma protein and albumin concentrations did not change significantly. Fasting plasma concentrations of amino acids after 3 months of amino acid dialysis were comparable to baseline values. For several amino acids, the dose-response curve was blunted after a single amino acid exchange following 3 months of amino acid dialysis, which may, in part, be due to the induction of hepatic enzyme synthesis. CONCLUSIONS: Amino acid dialysis is an efficient form of peritoneal dialysis that should be considered for children with poor nutritional status for whom enteral nutrition supplementation has been unsuccessful. Further study is needed to determine the optimal amount of amino acids to deliver, the best time to administer the amino acid dialysis fluid, and the benefits of adding dextrose to the amino acid solution.

Hemodialysis for end-stage renal disease in children weighing less than 10 kg.

Hemodialysis (HD) of infants with end-stage renal disease (ESRD) is technically difficult and labor intensive, although there are few data in the literature to document the outcomes of this treatment. We retrospectively reviewed all patients with ESRD who received HD between 1983 and 1997 who weighed <10 kg at the beginning of HD. A total of ten patients aged 2-27 months, weighing 3.5-9.5 kg, were identified. All patients were dialyzed through a central venous line; three had a failed sapheno-femoral loop and one a failed brachial shunt. Line clot was observed in nine and line sepsis in six patients. Subclavian vein stenosis was documented in one patient following removal of a clotted subclavian line. The mean urea reduction ratios calculated during the 1st and 3rd month of HD were only 54% and 49%, respectively. Anemia was a frequent problem, despite the use of erythropoietin in seven of the infants. Outcomes included: successful renal transplant in four, switch back to peritoneal dialysis in two, improved renal function and dialysis discontinuation in one, and death after withdrawal of treatment in three patients. All three patients who died were <5 months of age, weighed <5 kg, and were anuric; two of the three had congenital nephrotic syndrome. In conclusion, successful HD is possible in small children with ESRD, but morbidity is substantial and mortality is high.

The team approach to the management of children on chronic peritoneal dialysis.

The diagnosis of chronic renal failure has a profound and lasting impact on a child and family, with the potential for impairment of the child's physical, mental, and social development. To achieve an ideal outcome, the peritoneal dialysis (PD) team must focus on preparing the child and family to perform home dialysis, prescribe the dialysis regimen most compatible with the patient's lifestyle and clearance requirements, ensure optimal nutrition, and facilitate psychosocial adaptation to PD. Close follow-up is essential for early detection, prevention, and treatment of potential complications of dialysis. A multidisciplinary team approach encompassing nursing, medicine, nutrition, and social work best suits the needs of the child and family.

Effects of 3-month amino acid dialysis compared to dextrose dialysis in children on continuous ambulatory peritoneal dialysis.

OBJECTIVES: To compare the nutritional and biochemical effects of amino acid dialysis to dextrose dialysis in children receiving continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Prospective randomized crossover study. SETTING: Pediatric Nephrology Unit in a tertiary care, teaching hospital of the University of Toronto. PATIENTS: Seven children aged 0.7-16.5 years receiving CAPD. All patients had poor linear growth, with 5 patients showing evidence of energy deficit. INTERVENTIONS: Each patient received either amino acid or dextrose dialysate for 3 months, then crossed over to the alternate regimen for a subsequent 3 months. MAIN OUTCOME MEASURES: Nutritional and biochemical data were obtained on each patient during each dialysis regimen. RESULTS: Analysis of the patients' nutritional data showed comparable weight gain with both regimens but no significant improvement in lean body mass with either regimen. Appetite improved in most patients during amino acid dialysis. Biochemical data during amino acid dialysis showed a tendency to higher plasma potassium and urea levels with no clinical side effects or worsening of acidosis; however, there was a reduced anion gap and increased total plasma protein, due mostly to a rise in plasma albumin and a smaller increase in immunoglobulins. With the exception of tryptophan, fasting amino acid levels at the start and end of amino acid dialysis did not show any significant change. An interesting phenomenon of early blunting of the rise in amino acid levels, following a single amino acid dialysate exchange, was noticed at the end of the amino acid dialysis period. This newly described phenomenon could have been due to tolerance or hepatic enzyme induction. CONCLUSIONS: Overall amino acid dialysis was comparable to dextrose dialysis with no additional proven nutritional benefit, was equally effective in ultrafiltration and creatinine clearance, and produced no adverse clinical or biochemical effects.

Decrease in gastric emptying time and episodes of regurgitation in children with spastic quadriplegia fed a whey-based formula.

The gastric emptying times associated with three whey-based formulas were significantly shorter than that associated with a casein-based formula in nine gastrostomy-fed patients with spastic quadriplegia (p less than 0.001). Patients fed whey-based formulas had significantly fewer episodes of emesis than when they were fed casein-based formula (p less than 0.001). We conclude that whey-based formulas reduce the frequency of emesis by improving the rate of gastric emptying.

Gas-permeable lifecell tissue culture flasks give improved growth of Helicobacter pylori in a liquid medium.

Experiments were conducted to investigate the microaerobic culture of Helicobacter pylori in a liquid medium by using gas-permeable Lifecell tissue culture flasks. Growth in Lifecell tissue culture flasks was 1.2 to 1.6 log units greater than that in glass control bottles. These results were comparable to those reported by the use of gyrated media.

Tube feeding in children on chronic peritoneal dialysis.

We feel that tube feeding children on CPD is an important and useful therapy to optimize their growth. Strategies to accelerate growth in such children by using human growth hormone are interesting and await scientific confirmation with controlled trials.