The provision of recipes and single-use herb/spice packets to increase egg and protein intake in community-dwelling older adults: a randomised controlled trial.

OBJECTIVE: This study investigated the impact of recipe and single-use herb/spice packet provision on egg intake and protein intake in community-dwelling individuals aged over 55 years. DESIGN: Using a randomised-controlled intervention design, 100 older adults were randomised to receive (n 53) or not receive (n 47) high-protein egg-based recipes and herb/spice packets through the post for 12 weeks, from June to December 2016. Egg intake, protein intake, adverse events, lean body mass and functional measures of lean body mass were measured at baseline, after the 12 weeks and after a further 12 weeks. SETTING: Bournemouth, UK. PARTICIPANTS: Community-dwelling older adults. RESULTS: Intention-to-treat data were analysed using regression, controlling for various demographic and lifestyle characteristics. Ninety-three individuals (intervention, n 50; control, n 43) completed assessments at all three time points. Egg intakes increased by end of intervention in both groups (mean: 4-5 eggs/month). After a further 12 weeks, higher egg intakes were sustained in the intervention group, while egg intakes in the control group returned to baseline levels (between-group difference: ß = -0·124, P = 0·047). No differences were found in other measures (largest ß = -0·106, P = 0·12). CONCLUSIONS: The provision of high-protein egg-based recipes and single-use herb/spice packets over 12 weeks increased egg intakes up to 12 weeks after end of intervention. Other factors may explain increased egg intakes during the intervention, but the sustained effects most plausibly result directly from recipe provision. Limited effects in other measures suggest that the recipes may have replaced as opposed to added to existing protein intakes.

Identifying older people at risk of malnutrition and treatment in the community: prevalence and concurrent validation of the Patients Association Nutrition Checklist with 'MUST'.

BACKGROUND: Despite policy guidance and quality standards, the majority of older adults with or at risk of malnutrition living in the community still remain under-detected and under-treated by health and social care professionals. The present study aimed to evaluate the concurrent validity of the Patients Association Nutrition Checklist against the 'Malnutrition Universal Screening Tool' ('MUST'). METHODS: This cross-sectional study involved 312 older adults recruited from 21 lunch and social groups. All participants were screened as per standard methodology for 'MUST'. For the Patients Association Nutrition Checklist, they provided information about signs of unintentional weight loss in the past 3-6 months, experiencing loss of appetite or interest in eating. Chance-corrected agreement (κ) was assessed. RESULTS: Mean (SD) age of participants was 79.6 (8.3) years and body mass index was 27.8 (5.6) kg m-2 . The majority (n = 197; 63%) were living alone. Using 'MUST', the overall prevalence of malnutrition was 9.9% (n = 31) comprising 6.7% at medium risk and 3.2% at high risk. There were 21.8% of participants (n = 68) rated at risk of overall malnutrition by the Patients Association Nutrition Checklist. Moderate agreement was observed between the two tools (κ = 0.47, P < 0.001). CONCLUSIONS: The Patients Association Nutrition Checklist has potential for early identification of malnutrition risk, attributed to unintentional weight loss and appetite changes with signposting to basic dietary advice and appropriate support. Further work is required to understand how this tool could be effectively used by stakeholders including volunteers, community workers and home care staff.

Efficacy of a solar concentrator to Inactivate E. coli and C. perfringens spores in latrine waste in Kenya.

Alternative sanitation options are needed for effective waste management in low-income countries where centralized, large-scale waste treatment is not easily achievable. A newly designed solar concentrator technology utilizes solar thermal energy to treat feces contained in drums. This pilot study assessed the efficacy of the new design to inactivate microbes in 13 treatment drums under field conditions in Kenya. Three-quarters of the drums contained <1000 E. coli/g of total solids following 6 h of solar thermal treatment and inactivation of thermotolerant C. perfringens spores ranged from <1.8 to >5.0 log10. Nearly all (94%) samples collected from treatment drums achieved thermophilic temperatures (>50 °C) during the treatment period, however this alone did not ensure samples met the WHO E. coli guideline; higher, sustained thermophilic temperatures tended to be more effective in reaching this guideline. The newly designed solar concentrator was capable of inactivating thermotolerant, environmentally-stable microorganisms as, or possibly more, efficiently than a previous design. Additional data are needed to better characterize how temperature, time, and other parameters affect the ability of the solar concentrator to inactivate microbes in feces.

Environmental Survey of Drinking Water Sources in Kampala, Uganda, during a Typhoid Fever Outbreak.

In 2015, a typhoid fever outbreak began in downtown Kampala, Uganda, and spread into adjacent districts. In response, an environmental survey of drinking water source types was conducted in areas of the city with high case numbers. A total of 122 samples was collected from 12 source types and tested for Escherichia coli, free chlorine, and conductivity. An additional 37 grab samples from seven source types and 16 paired large volume (20 liter) samples from wells and springs were also collected and tested for the presence of Salmonella enterica serovar Typhi. Escherichia coli was detected in 60% of kaveras (drinking water sold in plastic bags) and 80% of refilled water bottles; free chlorine was not detected in either source type. Most jerry cans (68%) contained E. coli and had free chlorine residuals below the WHO-recommended level of 0.5 mg/liter during outbreaks. Elevated conductivity readings for kaveras, refilled water bottles, and jerry cans (compared to treated surface water supplied by the water utility) suggested that they likely contained untreated groundwater. All unprotected springs and wells and more than 60% of protected springs contained E. coli Water samples collected from the water utility were found to have acceptable free chlorine levels and no detectable E. coli While S Typhi was not detected in water samples, Salmonella spp. were detected in samples from two unprotected springs, one protected spring, and one refilled water bottle. These data provided clear evidence that unregulated vended water and groundwater represented a risk for typhoid transmission.IMPORTANCE Despite the high incidence of typhoid fever globally, relatively few outbreak investigations incorporate drinking water testing. During waterborne disease outbreaks, measurement of physical-chemical parameters, such as free chlorine residual and electrical conductivity, and of microbiological parameters, such as the presence of E. coli or the implicated etiologic agent, in drinking water samples can identify contaminated sources. This investigation indicated that unregulated vended water and groundwater sources were contaminated and were therefore a risk to consumers during the 2015 typhoid fever outbreak in Kampala. Identification of contaminated drinking water sources and sources that do not contain adequate disinfectant levels can lead to rapid targeted interventions.

Therapeutic Application of Monoclonal Antibodies in Multiple Sclerosis.

Multiple sclerosis (MS) is a heterogeneous inflammatory demyelinating disorder of the central nervous system (CNS). People with MS typically have a relapsing remitting disease course, with episodic neurological dysfunction corresponding to inflammation in the brain or spinal cord. Some relapsing patients develop a secondary progressive disease course, with accumulation of disability over time, yet other people with MS only experience a primary progressive course. Over the past 20 years, 14 immunomodulatory therapies have been approved in MS in order to reduce the frequency of inflammatory relapses and prevent CNS damage. Of the available types of therapies, the monoclonal antibodies are generally the most effective at dampening MS disease activity. In this review we will discuss the development of effective monoclonal antibody therapies coinciding with a better understanding of the complex immunopathogenesis of MS, both successes and failures, as well as targets for future development that address the mechanisms underlying progressive disease.

Development of a noninvasive system for monitoring dairy cattle sleep.

Limited research has been conducted to assess sleep in production livestock primarily because of limitations with monitoring capabilities. Consequently, biological understanding of production circumstances and facility options that affect sleep is limited. The objective of this study was to assess if data collected from a proof-of-concept, noninvasive 3-axis accelerometer device are correlated with sleep and wake-like behaviors in dairy cattle. Four Holstein dairy cows housed at the University of Kentucky Coldstream Dairy in September 2013 were visually observed for 2 consecutive 24-h periods. The accelerometer device was attached to a harness positioned on the right side of each cow's neck. Times of classified behaviors of wake (standing, head up, alert, eyes open) or sleep-like behaviors (lying, still, head resting on ground, eyes closed) were recorded continuously by 2 observers who each watched 2 cows at a time. The radial signal was extracted from 3 different axes of the accelerometer to obtain a motion signal independent of direction of movement. Radial signal features were examined for maximizing the performance of detecting sleep-like behaviors using a Fisher's linear discriminant analysis classifier. The study included 652min of high-activity wake behaviors and 107min of sleep-like behavior among 4 cows. Results from a bootstrapping analysis showed an agreement between human observation and the linear discriminant analysis classifier, with an accuracy of 93.7±0.7% for wake behavior and 92.2±0.8% for sleep-like behavior (±95% confidence interval).This prototype shows promise in measuring sleep-like behaviors. Improvements to both hardware and software should allow more accurate determinations of subtle head movements and respiratory movements that will further improve the assessment of these sleep-like behaviors, including estimates of deep, light, and rapid eye movement sleep. These future studies will require simultaneous electroencephalography and electromyography measures and perhaps additional measures of arousal thresholds to validate this system for measuring true sleep.

Free-space optical communications research and demonstrations at the U.S. Naval Research Laboratory.

Free-space optical communication can allow high-bandwidth data links that are hard to detect, intercept, or jam. This makes them attractive for many applications. However, these links also require very accurate pointing, and their availability is affected by weather. These challenges have limited the deployment of free-space optical systems. The U.S. Naval Research Laboratory has, for the last 15 years, engaged in research into atmospheric propagation and photonic components with a goal of characterizing and overcoming these limitations. In addition several demonstrations of free-space optical links in real-world Navy applications have been conducted. This paper reviews this work and the principles guiding it.

Reduction of scintillation in optical modulating retro-reflector links.

Optical modulating retro-reflectors enable free-space optical links that have greatly reduced pointing requirements and do not require a laser at one end of the link. However, these types of links can exhibit very high optical scintillation due to the double passage of the beam through the atmosphere. This high scintillation causes fades and surges that can lead to packet errors in the link. It is shown that scintillation can be greatly reduced through a combination of techniques including retro-reflector diversity, aperture averaging and bistatic optical interrogation. Improvements of 20 dB in link performance are demonstrated.

Ambient-temperature incubation for the field detection of Escherichia coli in drinking water.

AIMS: Escherichia coli is the pre-eminent microbiological indicator used to assess safety of drinking water globally. The cost and equipment requirements for processing samples by standard methods may limit the scale of water quality testing in technologically less developed countries and other resource-limited settings, however. We evaluate here the use of ambient-temperature incubation in detection of E. coli in drinking water samples as a potential cost-saving and convenience measure with applications in regions with high (>25°C) mean ambient temperatures. METHODS AND RESULTS: This study includes data from three separate water quality assessments: two in Cambodia and one in the Dominican Republic. Field samples of household drinking water were processed in duplicate by membrane filtration (Cambodia), Petrifilm™ (Cambodia) or Colilert® (Dominican Republic) on selective media at both standard incubation temperature (35­37°C) and ambient temperature, using up to three dilutions and three replicates at each dilution. Matched sample sets were well correlated with 80% of samples (n = 1037) within risk-based microbial count strata (E. coli CFU 100 ml−1 counts of <1, 1­10, 11­100, 101­1000, >1000), and a pooled coefficient of variation of 17% (95% CI 15­20%) for paired sample sets across all methods. CONCLUSIONS: These results suggest that ambient-temperature incubation of E. coli in at least some settings may yield sufficiently robust data for water safety monitoring where laboratory or incubator access is limited.

Detection of cytochrome c oxidase activity and mitochondrial proteins in single cells.

Cytochrome c oxidase or mitochondrial respiratory chain complex IV is where over 90% of oxygen is consumed. The relationship between complex IV activity and mitochondrial proteins, which provides a guide to understanding the mechanisms in primary mitochondrial disorders, has been determined by histochemistry (activity) and immunohistochemistry in serial sections. In the central nervous system (CNS), mitochondrial activity and immunoreactivity have been determined in populations of cells in serial sections as capturing cells in more than one section is difficult. In this report we describe a method to determine complex IV activity in relation to mitochondrial proteins at a single cell level in the CNS. We performed complex IV histochemistry and immunohistochemistry consecutively in snap frozen sections. Although the product of complex IV histochemistry reduces the sensitivity of standard immunohistochemistry (secondary antibody and ABC method) the biotin-free Menapath polymer detection system (A. Menarini Diagnostics, Wokingham, UK) enables mitochondrial proteins to be detected following complex IV histochemistry. The co-occurring chromogens may then be separately visualised and analysed using multi-spectral imaging (Nuance system CRi, Woburn, MA). Our technique is applicable for exploring mitochondrial defects within single cells in a variety of CNS disorders and animal models of those diseases.

Maldigestion and malabsorption of dietary lipid during severe childhood malnutrition.

BACKGROUND: Diets rich in lipid are used to provide energy density in treating children with severe malnutrition, but the extent to which their digestion and absorption can cope with the load effectively is uncertain. AIM: To determine the extent of impaired digestion or absorption, in three groups of eight malnourished children (aged 5-23 months) using isotopic probes of the predominant fatty acids in coconut and corn oil used to fortify the diet. METHODS: Each child received oral doses of one of three (13)C labelled triglycerides (trilaurin, triolein, or trilinolein). The recovery of (13)C label in stool either as triglyceride (TAG) or fatty acid (FA), was used to assess digestion and absorption. In a separate test, the recovery of label in stool following an oral dose of [(13)C]-glycocholate was measured to assess bile salt malabsorption. RESULTS: The median recovery of label in stool was 9% (range 1-29%) of administered dose. Following treatment there was a reduction in stool (13)C excretion for the labelled TAG (<1%). In half the subjects, label was recovered as TAG in stool (median 0.6%, range 0-44%). Most label in stool was recovered as FA (median 30%, range 0-100%). Following [(13)C]-glycocholate, label was recovered in excess in about one third of studies. CONCLUSION: Abnormalities in the gastrointestinal handling of lipid were observed in over 50% of children with severe malnutrition, reflecting problems in absorption, although impaired solubilisation or hydrolysis could also be contributory factors. The underlying lesion improves as treatment progresses, leading to concomitant improvement in function.

Influence of glucose ingestion by humans during recovery from exercise on substrate utilisation during subsequent exercise in a warm environment.

Carbohydrate (CHO) ingestion during short-term recovery from prolonged running has been shown to increase the capacity for subsequent exercise in a warm environment. The aim of this study was to examine the effects of the amount of glucose given during recovery on substrate storage and utilisation during recovery and subsequent exercise in a warm environment. A group of 11 healthy male volunteers took part in two experiments in a controlled warm environment (35 degrees C, 40% relative humidity), 1 week apart. On each occasion the subjects completed two treadmill runs (T1 and T2) at a speed equivalent to 60% of maximal oxygen uptake, for 90 min, until they were fatigued, or until aural temperature (T(aur)) reached 39 degrees C. The two runs were separated by a 4 h recovery period (REC), during which subjects consumed 55 g of naturally enriched [U-(13)C]-glucose in the form of a 7.5% carbohydrate-electrolyte solution (CES, mass of solution 667 g) immediately after T1. The subjects then consumed either: the same quantity of CES, or an equivalent volume of an electrolyte placebo, at 60, 120 and 180 min during REC, providing a total of 220 g (C220) or 55 g (C55) of [U-(13)C]-glucose, respectively. Expired gases were collected at 15 min intervals during exercise and 60 min intervals during REC, for determination of total CHO and fat oxidation by indirect respiratory calorimetry, and orally ingested [U-(13)C]-glucose oxidation, estimated from the (13)C:(12)C ratio of expired CO(2). Substrate metabolism did not differ between conditions during T1. Despite the fact that total CHO (P < 0.05) and ingested glucose oxidation (P < 0.01) were greater during REC of the C220 condition, glycogen synthesis was estimated to be approximately fivefold greater (P < 0.01) than in the C55 condition. During T2 the rate of total CHO oxidation was higher (P < 0.01) and total fat oxidation lower (P < 0.01) at all times during the C220 compared to the C55 condition. The greater CHO oxidation during C220 appeared to be met from ingested sources, as the rate of [U-(13)C]-glucose oxidation was greater (P < 0.01) at all times during T2, compared to C55. Whilst more of the ingested substrate remained unoxidised on completion of T2 during C220, exercise duration was similar in the two experimental conditions, and was limited by thermoregulatory incapacity (T(aur) > 39 degrees C) rather than substrate availability per se.

Exogenous carbohydrate oxidation from drinks ingested during prolonged exercise in a cold environment in humans.

Six healthy male volunteers performed four rides to exhaustion on a cycle ergometer at approximately 80% of maximal oxygen consumption. Subjects ingested a bolus volume of fluid (7.14 ml/kg) immediately before exercise and additional fluid volumes (1.43 ml/kg) every 10 min during exercise. The fluids ingested were either a flavored water control or glucose-electrolyte beverages with glucose concentrations of 2, 6, or 12%. The beverages were labeled with [U-(13)C]glucose (99.2%: 0.05 g/l). Exercise capacity was not different (P = 0.13) between trials; median (range) exercise time was 83.52 (79.85--89.68), 103.19 (78.82--108.22), 100.37 (80.60--124.07), and 94.76 (76.78--114.25) min in the 0, 2, 6, and 12% trials, respectively. The oxidation of exogenous glucose in each 15-min period was significantly lower in the 2% trial (P = 0.02) than in the 6 and 12% trials where oxidation rates were between 0.5 and 0.7 g/min. No difference in endogenous glucose oxidation was observed between trials (P = 0.71). These findings indicate that the oxidation of exogenous glucose during exercise of this intensity and duration in a cold environment is similar to that observed in warmer conditions. Thus a low oxidation of exogenous substrate is unlikely to be a factor limiting the effectiveness of carbohydrate-electrolyte drink ingestion on exercise capacity in a cold environment.

Gastrointestinal handling and metabolic disposal of 13C-labelled tripalmitin during rehabilitation from childhood malnutrition.

We investigated the gastrointestinal handling and post-absorptive metabolic handling of [1,1,1-13C]tripalmitin and [1-13C]glycocholate during recovery from severe childhood malnutrition. Eight children were studied on three occasions: at admission (phase 1), during rapid catch-up growth (phase 2) and when weight-for-height had reached 90 % of the reference (phase 3). Breath samples were obtained over a 24 h period and stools were collected over 3 d following the administration of each tracer. At admission, the lipid content of stool expressed as a percentage of ingested lipid was 6 (range 0.7-28.9) but less variation was shown between children at phase 2 (3.3 (range 0.9-4.1)) and phase 3 (1.4 (range 0.4-2.5)). The excretion of 13C in stool varied markedly between children at admission (11.1 (sd 5.4) % administered dose) and during rehabilitation (phase 2, 15.4 (sd 16.5) % administered dose; phase 3, 6.2 (sd 10.2) % administered dose). About 5 % of the absorbed label was recovered on breath at each stage (% absorbed dose; phase 1, 5.1 (sd 6.0); phase 2, 5.2 (sd 3.1); phase 3, 6.4 (sd 6.6)). None of the children exhibited significant bile salt malabsorption as a consequence of small intestinal overgrowth. Of the 13C measured in stool, more label was recovered in fatty acids than triacylglycerols during each of the three phases and this was interpreted to reflect a failure to absorb the products of digestion. The results show that not all the children had problems associated with the digestion and absorption of 13C-labelled tripalmitin in severe malnutrition and during recovery, which was not reflected in gross lipid balance across the gastrointestinal tract. Absorbed lipid was more likely to be deposited as adipose tissue than to satisfy the immediate needs for energy.

Metabolic handling of different fatty acids during rehabilitation from childhood malnutrition

The gastrointestinal handling and post absorptive metabolism of [1, 1, 1-13 C] triolein (TO) and [1, 1, 13 C] tripalmitin (TP) were studied in two groups of eight severely malnourished children (5-0 months): on admission (Phase 1), during rapid-catch up growth (Phase 2) and when weight for height had reached 90 percent of the reference (Phase 3). Total excretion of 13 C label in stool (over 3 days) and breath as 13 CO 2 (over 24 hours) were analysed by isotope radio mass spectrometry. Stool 13 C excretion at admission was approximately 10 percent of the administered dose for both trials but varied markedly between subjects, was significantly reduced during rehabilitation in the TO trial (Phase 2:0.5 +or- 1.0; Phase 3: 1.3 +or- 0.9; p<0.05) and tended to decline on the P trial. ANOVA analysis of the magnitude and time course of 13 C excretion in breath (from area under the curve), excretion tended to decrease during rehabilitation in the TO trial but remained unchanged on the TP trial. These results suggest that the efficiency with which dietary triacylglycerol is handled within the gastrointestinal tract is generally impaired in severely malnourished children at admission but improves during rehabilitation.(Au)

Metabolism of lactose-[13C]ureide and lactose-[15N,15N]ureide in normal adults consuming a diet marginally adequate in protein.

Oral lactose-ureide is resistant to human digestive enzymes, but is fermented by the colonic microflora. Nine normal adults consuming a diet which provided 36 g of protein/day were given oral doses of lactose-[(13)C]ureide and lactose-[(15)N,(15)N]ureide. The appearance on breath of (13)CO(2) derived from lactose-[(13)C]ureide was followed for 48 h. The fate of (15)N derived from lactose-[(15)N, (15)N]ureide was determined by measuring the recovery of (15)N in stools and urine in various forms. About 80% of the label given as lactose-[(13)C]ureide was recovered on the breath, and about 80% of label given as lactose-[(15)N,(15)N]ureide was not recovered in stool, indicating that 80% of the dose was completely fermented. At least 5% of the labelled urea was absorbed and excreted as the intact molecule. Of the (15)N derived from lactose-[(15)N, (15)N]ureide and available for further metabolic interaction, 67% was retained and 33% was excreted in urine. The time taken for [(15)N,(15)N]urea to appear in urine was similar for all subjects, but the appearance of either (13)CO(2) on the breath or [(15)N, (14)N]urea in urine varied. It is concluded that the hydrolysis of the sugar-urea bond may reflect oro-caecal transit time, but that other factors related to colonic bacterial metabolism determine the duration and extent of hydrolysis of urea by urease enzymes. Lactose-ureide can be used to probe the metabolic activity of the colonic microflora in normal individuals.

Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women.

The gastrointestinal handling and metabolic disposal of [1-13C]palmitic acid, [1-13C]stearic acid and [1-13C]oleic acid administered within a lipid-casein-glucose-sucrose emulsion were examined in normal healthy women by determining both the amount and nature of the 13C label in stool and label excreted on breath as 13CO2. The greatest excretion of 13C label in stool was in the stearic acid trial (9.2% of administered dose) whilst comparatively little label was observed in stool in either the palmitic acid (1.2% of administered dose) or oleic acid (1.9% of administered dose) trials. In both the palmitic acid and oleic acid trials, all of the label in stool was identified as being present in the form in which it was administered (i.e. [13C]palmitic acid in the palmitic acid trial and [13C]oleic acid in the oleic acid trial). In contrast, only 87% of the label in the stool in the stearic acid trial was identified as [13C]stearic acid, the remainder was identified as [13C]palmitic acid which may reflect chain shortening of [1-13C]stearic acid within the gastrointestinal tract. Small, but statistically significant, differences were observed in the time course of recovery of 13C label on breath over the initial 9 h of the study period (oleic acid = palmitic acid > stearic acid). However, when calculated over the 24 h study period, the recovery of the label as 13CO2 was similar in all three trials (approximately 25% of absorbed dose). These results support the view that chain length and degree of unsaturation may influence the gastrointestinal handling and immediate metabolic disposal of these fatty acids even when presented within an emulsion.

Metabolic handling of 13C labelled tripalmitin in healthy controls and patients with cystic fibrosis.

AIM: To examine the gastrointestinal handling and metabolic disposal of emulsified [1-13C]palmitic acid esterified into a triglyceride in nine healthy children and seven patients with cystic fibrosis on enzyme replacement treatment. METHODS: After an overnight fast, each child was given 10 mg/kg body weight [1,1,1-13C]tripalmitin with a standardised test meal of low natural 13C abundance. The total enrichment of 13C was measured using isotope ratio mass spectrometry in stool collected for a period of up to five days and in breath samples collected over a 24 hour period. RESULTS: The mean proportion of administered 13C label excreted in stool was 6% (range, 1-12.7%) in healthy children and 24.6% (range, 0-64%) in patients with cystic fibrosis. Healthy children excreted 31.3% of the administered label on their breath (range, 14.2-42.9%). Correcting the excretion of administered 13C label on the breath for differences in digestion and absorption in patients with cystic fibrosis increased the difference between individuals from 0-31.3% of administered dose (mean, 17.9%) to 0-49.1% of absorbed dose (mean, 23.2%) and was poorly related to the amount of 13C label in stool. CONCLUSION: Measurements of breath 13CO2 do not consistently reflect the gastrointestinal handling of emulsified 13C labelled tripalmitin because of differences in digestion and absorption in cystic fibrosis. Further studies need to examine whether "breath tests" alone can predict with confidence the gastrointestinal handling of other 13C labelled triglycerides and fatty acids.

Nutritional management in cystic fibrosis--an alternative perspective in gastrointestinal function.

The gastrointestinal problems in cystic fibrosis (CF) may limit energy and nutrient availability and also cause symptoms such as abdominal pain and disturbed bowel habit which may further suppress appetite or alter the diet. Taken together this may lead to an inadequate supply of energy and nutrients to meet the nutritional requirements of the individual resulting in restricted growth or weight loss. A failure to optimize the digestive and absorptive capacity of the gastrointestinal tract places greater emphasis upon nutritional management by food intake alone. Practitioners need to focus more on gastrointestinal dysfunction in CF and its impact upon food intake in order to improve the efficacy of nutritional management. Refined stable isotopic tracers allow further exploration of the pathophysiology of the gastrointestinal tract in terms of nutrient availability. In clinical practice, a closer assessment of gastrointestinal function is supported by the use of simple, noninvasive tools which, both objectively and systematically, characterize those patients who have problems.

The effect of age and gender on the metabolic disposal of [1-13C] palmitic acid.

OBJECTIVE: To examine the effect of age and gender on the metabolic disposal of [1-13C]palmitic acid. DESIGN: Cross-sectional. SETTING: Clinical Nutrition and Metabolism Unit at Southampton General Hospital, Institute of Human Nutrition, University of Southampton. SUBJECTS AND MEASUREMENTS: Twelve children (5 boys and 7 girls; aged 5-10 y) and six men (BMI 23.3 +/- 2.6 kg/m2; aged 20-30 y) were recruited. Following oral administration of a bolus dose of [1-13C]palmitic acid (10 mg/kg body weight) consumed with a test meal (1667 kJ) the excretion of 13C-label was measured on breath as 13CO2 over 24 h and in stool over 5 d to account for differences in absorption of [1-13C]palmitic acid. The 13C-enrichment of samples was determined by continuous flow-isotope ratio mass spectrometry. Net substrate oxidation was estimated from gaseous exchange measurements in the postabsorptive state and over 6 h postprandially. RESULTS: The excretion of 13CO2 on breath varied between subjects both in the pattern and amount excreted over 24 h. Breath 13CO2 was not different between boys (61.0 +/- 22.4% of absorbed dose) and girls (54.2 +/- 17.9% of absorbed dose). The excretion of breath 13CO2 was less in the men (35.1 +/- 9.3% of absorbed dose; P = 0.005) and that observed previously by our group in women (30.7 +/- 6.7% of absorbed dose; P = 0.005) than in the children. Net fat oxidation was greater in the children in both the postabsorptive (2.43 +/- 0.78 g/h) and postprandial (11.89 +/- 3.13 g/6 h) states than in the men (0.93 g/h +/- 1.50; P = 0.016; 9.86 +/- 10.53 g/6 h; NS) and women studied previously (0.53 +/- 0.68 g/h; P = 0.003; 0.03 +/- 3.21 g/6 h; P = 0.001). CONCLUSIONS: Our observations that children oxidised nearly twice the amount of [1-13C]palmitic acid than adults in conjunction with greater net fat oxidation in children than adults in both the postabsorptive and postprandial states should be considered before current UK dietary recommendations for fat and saturated fats, developed for adults, are applied to growing children. For dietary recommendations to be developed further more information is required, particularly in groups of infants and the elderly, about the factors that influence the postprandial handling of dietary fat.