Reproducibility of 'COST reference microplasma jets'.

Atmospheric pressure plasmas have been ground-breaking for plasma science and technologies, due to their significant application potential in many fields, including medicinal, biological, and environmental applications. This is predominantly due to their efficient production and delivery of chemically reactive species under ambient conditions. One of the challenges in progressing the field is comparing plasma sources and results across the community and the literature. To address this a reference plasma source was established during the 'biomedical applications of atmospheric pressure plasmas' EU COST Action MP1101. It is crucial that reference sources are reproducible. Here, we present the reproducibility and variance across multiple sources through examining various characteristics, including: absolute atomic oxygen densities, absolute ozone densities, electrical characteristics, optical emission spectroscopy, temperature measurements, and bactericidal activity. The measurements demonstrate that the tested COST jets are mainly reproducible within the intrinsic uncertainty of each measurement technique.

Longitudinal assessment of energy expenditure in pregnancy by the doubly labeled water method.

Twelve women were studied before pregnancy and at 6-wk intervals from 6 to 36 wk gestation. Total energy expenditure (TEE) by the doubly labeled water method, basal metabolic rate (BMR), energy intake, and body composition were assessed on each occasion. There was substantial interindividual variation in the response to pregnancy. Mean total energy costs were as follows: delta BMR 112 +/- 104 MJ (range -53 to 273), delta TEE 243 +/- 279 MJ (range -61 to 869 MJ), and fat deposition 132 +/- 127 MJ (range -99 to 280 MJ). The mean total cost of pregnancy (cumulative TEE above baseline+energy deposited as fat and as products of conception) was 418 +/- 348 MJ (range 34-1192 MJ). This was much higher than current recommendations for incremental energy intakes. Self-recorded incremental intakes (208 +/- 272 MJ) seriously underestimated the additional costs. The variability in response emphasizes the problems in making prescriptive recommendations for individual women, because there is no way of predicting metabolic or behavioral responses to pregnancy.

Longitudinal assessment of the components of energy balance in well-nourished lactating women.

The mechanisms by which well-nourished women meet the additional energy costs of lactation were studied by measuring energy intake (EI), basal metabolic rate (BMR), total energy expenditure by doubly labeled water (TEE), physical activity plus thermogenesis (TEE-BMR), changes in body fat stores, and milk energy transfer. Ten women were studied at 36 wk gestation; 4, 8, and 12 wk lactation (L4, L8, L12); and when nonpregnant and nonlactating (NPNL) after weaning. At L4, L8, and L12 the energy transferred in milk averaged 2245, 2225, and 2217 kJ/d with an additional 445 kj/d (106 kcal/d) estimated as being necessary for synthesis. EI was 1360, 1740, and 1275 kJ/d higher than the NPNL values, representing 56% of the costs of lactation. The remaining 44% was met by a reduction in TEE (-945, -688, and -826 kJ/d vs NPNL) caused largely by a reduction in physical activity because BMR was essentially unchanged (+29, -12, and -218 kJ/d). The energy-balancing strategies adopted by different women varied markedly.

Residual effect of graded levels of exercise on metabolic rate.

The hypothesis that exercise induces a residual effect on metabolic rate only when the intensity exceeds a certain threshold was tested by studying 10 healthy, untrained adults performing graded levels of bicycle ergometry on five separate occasions. The exercise consisted of four 30-min periods at intensities ranging from 0 to 100 Watts. Energy expenditure was measured by continuous indirect whole-body calorimetry. The highest level of exercise increased 24-h energy expenditure by 34 per cent. Food intake was modified for each measurement in order to maintain energy balance. Sleeping and basal metabolic rates on the night following exercise were raised even at low intensities of exercise. There was an almost linear dose-response relationship and no evidence of a threshold. However, the effect was small, amounting to only 5.8 per cent overnight and 3.9 per cent in the morning following 2 h exercise at over 60 per cent VO2 max during the preceding day. This suggests that the residual energy expenditure incurred after moderate levels of exercise is unlikely to be a very useful adjunct to slimming regimes.

Energy-sparing adaptations in human pregnancy assessed by whole-body calorimetry.

The hypothesis that the energy cost of human pregnancy can be minimized by energy-sparing metabolic adaptations was tested using serial 24 h whole-body calorimetry. Eight healthy, well-nourished women were studied prepregnant and at 6, 12, 18, 24, 30 and 36 weeks gestation. Basal metabolic rate (BMR) showed highly characteristic changes within each subject and large inter-individual differences (F 3.5, P less than 0.01). Some subjects showed a highly significant depression of metabolism up to 24 weeks gestation in support of the initial hypothesis. At 36 weeks BMR ranged from +8.6 to +35.4% relative to the prepregnant baseline. This wide variability was not explained by differences in the amount of lean tissue gained. Women displaying the energy-sparing suppression of BMR tended to be thin, suggesting that changes in metabolism may be responsive to initial energy status (delta BMR v. prepregnant body fat: r 0.84, P less than 0.005). Changes in 24 h energy expenditure closely paralleled changes in BMR (r 0.98, P less than 0.001), since the energy cost of minor voluntary activity and thermogenesis remained very constant within each individual. Pregnancy decreased the net cost of weight-dependent and weight-independent standard exercises when expressed per kg body-weight: stepping -10 (SD 2)%, P less than 0.001 at 18-36 weeks, cycling -26 (SD 7)%, P less than 0.01 at 12-36 weeks. The average integrated maintenance costs of pregnancy matched previous group estimates from well-nourished women, but individual estimates ranged from -16 to +276 MJ (coefficient of variation 93%). This high level of variability has important implications for the prescription of incremental energy intakes during pregnancy. It may also have had evolutionary significance.

Approaches to estimating physical activity in the community: calorimetric validation of actometers and heart rate monitoring.

The relationship between actometer measurements, heart rate monitoring and energy expenditure during exercise and resting periods was assessed in a whole-body indirect calorimeter on 12 young male volunteers. Equations derived from these studies were applied to actometer measurements taken during a further 7 d recording in free-living conditions to predict daily energy expenditure over 1 week on an individual basis. Actometers proved to be a satisfactory means of estimating energy expenditure and heart rate monitoring improved the estimates in a few selected subjects. Indirect measures of energy expenditure could be developed by this approach but individual calibration is essential.

Overnight and basal metabolic rates in men and women.

The FAO/WHO/UNU recommendations for energy requirements assume that the energy cost of sleep is equal to the basal metabolic rate (BMR). We have tested the validity of this assumption by analysing overnight and BMR measurements made by whole-body indirect calorimetry. Data from 80 healthy subjects measured on a total of 246 occasions have been used. In a subgroup of 40 normal lean subjects the mean ratio of overnight metabolic rate (Overnight MR): BMR was 0.95 (range 0.85 - 1.02, s.d. 0.04). The mean ratio of lowest sleeping metabolic rate (Lowest SMR): BMR was 0.88 (range 0.83 - 0.96, s.d. 0.04). Ratios of Overnight MR: BMR were not significantly affected by different levels of exercise on the preceding day. This ratio was significantly higher for subjects who were obese, late pregnant or attached to ECG electrodes. With the exception of the late pregnant subjects these groups had the same Lowest SMR:BMR ratios as the normal lean subjects, indicating that the higher Overnight MR was caused by disturbed sleep. The data suggest that the use of BMR to estimate overnight energy expenditure would introduce an average overestimate of approximately 5 per cent during the actual hours of sleep, but that when applied over 24 h the error becomes negligible.

Intra-individual variability and measurement noise in estimates of energy expenditure by whole body indirect calorimetry.

1. Four men were each studied continuously over 12 d in a whole-body calorimeter. Dietary intake and daily activities were kept constant throughout the study. 2. Day-to-day coefficients of variation in energy expenditure within subjects were found to be 1.97% over 24 h, 5.93% during basal metabolic rate measurement, 2.40% overnight and 3.22% in exercise. 3. The contribution of measurement system noise to the observed variability was analysed and shown to be generally small. The source of this noise was considered. 4. The results reinforce and extend other comparable reports and show that within-subject variability forms a small part of reported observations of between-subject variability.

High levels of energy expenditure in obese women.

Total free living energy expenditure was compared in lean and obese women by the new doubly labelled water method and partitioned into basal metabolism and thermogenesis plus activity by whole body calorimetry. Average energy expenditure was significantly higher in the obese group (10.22 versus 7.99 MJ/day (2445 versus 1911 kcal/day); p less than 0.001) resulting from an increase in the energy cost of both basal metabolism and physical activity. Self recorded energy intakes were accurate in the lean subjects but underestimated expenditure by 3.5 MJ/day (837 kcal/day) in the obese group. Basal metabolic rate and energy expenditure on thermogenesis plus activity were identical in the two groups when corrected for differences in fat free mass and total body mass. In the obese women in this series there was no evidence that their obesity was caused by a metabolic or behavioural defect resulting in reduced energy expenditure.

Unexpectedly low levels of energy expenditure in healthy women.

A new method for measuring total energy expenditure (TEE) with stable isotopically labelled water (2H218O) was used to measure average daily energy expenditure over 14-21 day periods in 12 healthy women following their normal activity patterns. TEE expressed as a multiple of basal metabolic rate (TEE/BMR) averaged only 1 X 38 +/- 0 X 04. This result is at variance with the widely held assumption that minimum maintenance requirements are 1 X 5 times BMR.

An assessment of ciclazindol in stimulating thermo-genesis in human volunteers: a detailed metabolic study.

Seven normal-weight young men lived for seven weeks in a metabolic unit on a diet (12 per cent protein, 30 per cent fat) equivalent in energy content to that calculated from a previous seven-day weighted intake. Three different doses of ciclazindol and a placebo were given for a week each on a Latin Square double-blind cross-over basis. At the end of each experimental week the subject occupied a whole-body indirect calorimeter at 26 degrees C for 36 h. Heart rate was monitored and a strict time-table of activity defined. Appetite and mood were assessed throughout the study period. Faecal and urinary energy excretion were used to define metabolisable energy intake. Multiple regression analysis showed a small but dose-dependent increase in energy output with the drug. This effect was present during the daytime when the subject was active and fed but not at night when he was lying still in bed. Heart rate rose significantly in both the day and night, and sleep was shortened. Appetite was suppressed; however, all but one subject maintained the diet. In conclusion, ciclazindol in man affects appetite, has a general arousal and a small thermogenic effect.

A model for zinc metabolism in sheep given a diet of hay.

1. Four pairs of Scottish Blackface ewes were given a basal diet of hay, providing 8 mg zinc/d, and one of four levels of supplementary Zn (0,75, 150 or 225 mg/d) continuously by intraruminal infusion. 2. 65Zn (59 microCi) was given intravenously after stabilization for 14 d and the changes in specific radioactivity (SR) of plasma and faeces were monitored for a further 10 and 13 d respectively. The faecal endogenous losses and absorption of Zn were estimated, using the principle of isotope dilution, by two methods using the whole or latter parts of SR:time curves. 3. Faecal endogenous losses were estimated by the part area method to be 4.9, 6.4, 5.1 and 6.3 +/- 0.35 mg/d at 0, 75, 150 and 225 mg supplemental Zn/d i.e. largely unaffected by Zn intake and averaging 0.11 mg/kg live weight (LW). The whole area method gave similar results. 4. Urinary excretion was negligible (probably less than 0.2 mg/d) for all sheep. 5. The amount of Zn absorbed was assumed to equal the irreversible loss of Zn under steady-state conditions and found to remain constant at 7.6 +/- 0.39 and 10.3 +/- 0.6 mg/d when calculated by "whole' and "part area' methods. Zn retention did not increase with Zn intake and homoeostasis was achieved primarily by control of Zn absorption which fell from 0.75 to 0.03 or from 0.96 to 0.05 of intake, depending on method of calculation, as intakes increased.

Elevated metabolic rates in obesity.

The resting metabolic rates (R.M.R.s) of 69 obese patients were measured during a period of weight stability. All except 4 women had a rate, in megajoules per 24 hours, in excess of that for subjects of normal weight. This increased R.M.R. is obscured by the traditional method of expressing R.M.R. per unit surface area. The high R.M.R. in the obese state was related not to the excess fat but to a 36% and 32% increase in the lean body mass of the men and women respectively. The R.M.R.s of 30 patients measured during weight-loss fell. The increase in R.M.R. in obesity is an important mechanism for achieving energy balance, whereas the progressive fall in R.M.R. during slimming demonstrates the need for a permanent reduction in food intake if energy balance is to be maintained on reaching normal weight. Measuring only the R.M.R. in the obese state is unlikely to help in understanding the pathogenesis of obesity.

Cimetidine in the management of the Zollinger-Ellison syndrome.

The first case of the Zollinger-Ellison syndrome treated from the outset continuously for more than a year with the histamine H2-receptor antagonist cimetidine is reported. Symptomatic response has been dramatic and sustained, marked endoscopic improvement has been observed with healing of oesophageal, gastric and stomal ulcers.

Letter: Oestrous cycles in swes grazing different cultivars of subterranean clover.

PIP: A brief account of an experiment concerning conception rates for Merino ewes grazing on high-estrogen and on low-estrogen cultivars is given. The ewes were mated to Merino rams for 8 weeks annually during March and April. Cycle lengths were measured over 5 mating periods on 87 Merino ewes and 62 crossbred ewes on high-estrogen cultivars and on 46 Merino ewes and 36 crossbred ewes on low-estrogen cultivars. There was a lack of significant interaction over time and of significant differences for mean cycle lengths between Merinos and crossbreds and between ewes grazing the 5 cultivars. The results support the conclusions of Underwood that the infertility of ewes grazing high-estrogen clover is unrelated to a disturbance of the estrous cycle. The results of Loghtfoot who found no significant difference in incidence of estrous and ovarian activity in 16 crossbred ewes and 16 control ewes grazing Dwalganup pastures are supported.^ieng