Determinants of fat mass in prepubertal children.

The aim of the present study was to compare variables of metabolism, physical activity and fitness to body composition in normal and overweight children in a cross-sectional study design. Body composition was assessed by anthropometric measurements and bioelectrical impedance analysis in forty-eight prepubertal children (age 5-11 years, thirteen normal-weight, thirty-five overweight). Total energy expenditure (EE) was measured by combination of indirect calorimetry (for measurement of resting EE) and individually calibrated 24 h heart-rate (HR) monitoring. Activity-related EE and physical activity level (PAL) were calculated. Time spent with min-by-min HR>FLEX HR was also used as a marker of moderate habitual and vigorous activities. Aerobic fitness (O2 pulse (O2 consumption:HR at submaximal steady-state heart rate), submaximal O2 consumption (VO2submaximal), RER at a HR of 170 beats per min) was determined by bicycle ergometry. Muscle strength of the legs (maximal isometric strength of musculus quadriceps and of musculus ischiocruralis (Fa max and Fb max respectively)) was measured by computer tensiometry. When compared with normal children, overweight children had higher skinfold thicknesses (sum of skinfold thicknesses at four sites +160 %), fat mass (+142 %), waist (+24 %) and hip circumferences (+14 %), resting EE (+13 %) and RER (+5 %). No significant group differences were found for fat-free mass, muscle mass, total EE, activity-related EE, PAL, HR>FLEX HR, VO2submaximal, O2 pulse, Fa max and Fb max as well as the fat-free mass- or muscle mass-adjusted values for resting EE, aerobic fitness and muscle strength. When compared with normal children, overweight children had a lower measured v. estimated resting EE (Delta resting EE) and spent more time watching television. There were positive relationships between fat-free mass(x) and resting EE(x), total EE(y), aerobic fitness(y) and muscle strength(y), but only Delta resting EE(x) and HR>FLEX HR(x) correlated with fat mass(y). In a stepwise multivariate regression analysis resting EE adjusted for fat-free mass and Delta resting EE were significant determinants of % fat mass and explained 29.7 % of its variance. Thus, in the present cross-sectional study, resting EE was the most important determinant of fat mass.

A case of idiopathic nodular glomerulosclerosis mimicking diabetic glomerulosclerosis (Kimmelstiel-Wilson type).

A case of idiopathic nodular glomerulosclerosis mimicking diabetic Kimmelstiel-Wilson glomerulopathy is reported. The patient was a 45-year-old man suffering from nephrotic syndrome. Light and electron microscopy revealed diffuse and nodular glomerulosclerosis indistinguishable from diabetic nodular glomerulosclerosis. Diabetes mellitus, however, had been excluded both by extensive clinical and by laboratory investigation. The differential diagnosis also included amyloidotic and non-amyloidotic fibrillary glomerulopathy, light chain glomerulopathy, collagen type III disease, immunotactoid glomerulopathy, and the sclerosing variant of membranoproliferative glomerulonephritis. Immunohistochemistry and ultrastructural investigations, however, excluded these entities, and the diagnosis of idiopathic nodular glomerulosclerosis was made. This variant has to be included in the differential diagnosis of nodular glomerulopathy associated with nephrotic syndrome.

Prevention of obesity--more than an intention. Concept and first results of the Kiel Obesity Prevention Study (KOPS).

OBJECTIVE: Obesity prevention is necessary to address the steady rise in the prevalence of obesity. Although all experts agree that obesity prevention has high priority there is almost no research in this area. The effectiveness of different intervention strategies is not well documented. There is also no structured framework for obesity prevention. DESIGN: Based on (i) our current and limited knowledge and (ii) the idea that prevention of childhood obesity is an effective treatment of adult obesity, the Kiel Obesity Prevention Study (KOPS) was started in 1996. Concept, intervention strategies and first results of KOPS are reported in this paper. KOPS is an ongoing 8 y follow-up study. We first enrolled a large scale cohort of 5 to 7-y-old children, providing sufficient baseline data. KOPS allows further analyses of the role of individual risk factors as well as of long-term effectiveness of different intervention strategies. RESULTS: From 1996 to 1999 a representative group of 2440 5 to 7-y-old children was recruited (ie 30.2% of the total population of 5 to 7-y-old children examined by the school physicians) and a full data set was obtained from 1640 children. Of the children, 340 (20.7%) were considered as overweight and obese, 1108 children (67.6%) were normal weight, and underweight was found in 192 children (11.7%). Of the normal-weight children, 31% or 346 (21.1% of the total population) were considered to have a risk of becoming obese. Cross-sectional data provided evidence that (i) there is an inverse social gradient in childhood overweight as well as health-related behaviours and (ii) parental fatness had a strong influence on childhood overweight. We observed considerable changes in health-related behaviours within 1 y after combined "school-" and "family-based" interventions. Interventions aimed to improve health-related behaviours had significant effects on the age-dependent increases in median triceps skinfolds of the whole group (from 10.9 to 11.3 mm in "intervention schools" vs from 10.7 to 13.0 mm in "control schools", P<0.01) as well as in percentage fat mass of overweight children (increase by 3.6 vs 0.4% per year without and with intervention, respectively; P<0.05). CONCLUSION: First results of KOPS are promising. Besides health promotion, a better school education and social support seem to be promising strategies for future interventions.

Association between different attributes of physical activity and fat mass in untrained, endurance- and resistance-trained men.

The objective of this cross-sectional study was to assess different attributes of physical activity and fitness and their relationship to nutritional state in endurance- and resistance-trained, compared to untrained men. The subjects were 42 men matched for age, of which 13 were untrained [UT, mean age 30.2 years, mean height 180.7 cm, mean body mass 83.6 kg, mean body mass index (BMI) 25.6 kg.m-2], 14 were endurance-trained athletes (ET, mean age 29.6 years, mean height 178.4 cm, mean body mass 74.0 kg, mean BMI 23.2 kg.m-2) and 15 were resistance-trained athletes (RT, mean age 28.4 years, mean height 183.4 cm, mean body mass 94.1 kg, mean BMI 27.4 kg.m-2). Fat mass (FM), fat free mass (FFM), muscle mass (MM) and total body water (TBW) were assessed using anthropometry and bioelectrical impedance analysis. Resting energy expenditure was measured by indirect calorimetry (IC) and total energy expenditure (TEE) by a combination of IC and individually calibrated 24-h heart-rate monitoring. The activity related energy expenditure (AEE) and the physical activity level were calculated. Movements were assessed using pedometry. Aerobic fitness was determined using ergometry, muscle strength [quadriceps muscle (Famax), ischiocruralis muscle (Fbmax), biceps muscle (Fcmax), triceps muscle (Fdmax)] by computer tensiometry. Different time domain indexes of heart rate variability (HRV) were examined during sleep, rest and the whole day as an index of sympathetic nervous system (SNS) activity. When compared with UT and RT, ET had reduced body masses and FM, but increased percentage TBW (P < 0.05 and P < 0.01, respectively). FFM and MM were increased in RT, when compared with UT and ET (P < 0.01). ET had higher TEE, AEE, pedometry derived activities, oxygen consumption and power during vigorous exercise than RT and UT (P < 0.05 and P < 0.01, respectively). Respiratory exchange ratio at moderate exercise intensities was increased in RT (P < 0.05). In the 12 time domain indexes of HRV 6 and 10 were higher in ET than in RT and UT respectively (P < 0.05 or P < 0.01, respectively) suggesting an increased SNS activity in ET. By contrast, Famax, Fcmax and Fdmax were elevated in RT (P < 0.01). FM was negatively associated with aerobic fitness, but not with muscle strength. We concluded that the physiological and metabolic adaptations to exercise and nutritional state differ between ET and RT subjects. Participation in RT results predominantly in changes in body composition and strength but not in energy expenditure, movements and SNS activity. The opposite was the case for ET. Aerobic fitness, physical activity, movements and activity of SNS were all increased but body mass and FM were decreased. The latter finding may support the idea that, with regard to possible health benefits, ET is more effective than RT.

Prevention of obesity--is it possible?

Obesity prevention is necessary to address the steady rise in the prevalence of obesity. Although all experts agree that obesity prevention has high priority there is almost no research in this area. There is also no structured framework for obesity prevention. The effectiveness of different intervention strategies is not well documented. Regarding universal prevention little rigorous evaluation has been carried out in larger populations. Obesity prevention has been integrated into community-wide programmes preventing coronary heart disease. Although effective with respect to reduction in cardiovascular risk factors these programmes did not affect mean body mass index (BMI) of the target populations. Selective prevention directed at high risk individuals (e.g. at children with obese parents) exhibited various degrees of effectiveness. However, at present, definitive statements cannot be made because of the limited number of studies as well as limits in study design. Finally, targeted prevention produced promising results in obese children when compared to no treatment. However, there are only very few longterm follow-up data. There is no clear idea about comprehensive interventions studying combinations of different strategies. It is tempting to speculate that predictors of treatment outcome (e.g. psychological and sociodemographic factors) may also serve as barriers to preventive strategies, but this has not yet been investigated. Taken together, obesity prevention should become a high priority research goal. First results of obesity prevention programmes are promising. As well as health promotion and counselling, better school education and social support appear to be promising strategies for future interventions.

Is TV viewing an index of physical activity and fitness in overweight and normal weight children?

OBJECTIVE: To assess relationships between TV viewing and body composition, energy expenditure, physical activity, fitness and nutrition habits in prepubertal children. DESIGN: Cross-sectional study. SUBJECTS: Sixty prepubertal children (mean body mass index: 20.8 kg m(-2), age: 5-11 years, overweight: n = 52, normal weight: n = 8). METHODS: TV consumption, socio-economic status (SES) and nutrition habits were estimated by questionnaires. Fat mass and fat-free mass were assessed by anthropometrics and bioelectrical impedance analysis, and resting energy expenditure by indirect calorimetry. Total energy expenditure was measured by a combination of indirect calorimetry and individually calibrated 24-hour heart rate (HR) monitoring. Activity-related energy expenditure and physical activity level were calculated. Aerobic fitness (VO2 submax) was determined by ergometry, muscle strength (musculus quadriceps, musculus ischiocruralis) was measured by computer tensiometry. Children were stratified according to their daily TV consumption: 1 h of TV per day (group II). RESULTS: When compared with children of group I, children of group II had increased body weight, body mass index, skinfolds, fat mass and prevalence of overweight (P < 0.05 and <0.01, respectively). By contrast, fat-free mass, energy expenditure, measures of physical activity and muscle strength were similar. Children of group II had normal absolute VO2 submax but reduced adjusted VO2 submax (P < 0.05). They also had parents with a lower educational level (P < 0.05). Similar nutritional habits were observed in both groups. There were no significant differences in the observed parameters between children with high (1-3 h day(-1)) and very high (>3 h day(-1)) TV viewing. CONCLUSIONS: There is a positive relationship between TV viewing and fatness. Increased TV viewing does not reflect reduced 24-hour energy expenditure as assessed by 24-hour HR monitoring, submaximal VO2, muscle strength or poor dietary intake. Increased TV consumption is associated with a low SES.

Relationships between physical activity, physical fitness, muscle strength and nutritional state in 5- to 11-year-old children.

The purpose of the present study was to assess different aspects of physical activity and fitness in order to develop a basis for sport programmes for overweight and obese children. Eighty-eight prepubertal children (49 boys, 39 girls, 4.8-11.4 years old, 61% obese, 14% overweight and 25% normal weight) were examined. Body composition was assessed by combined use of anthropometrics and bioelectrical impedance analysis. Resting energy expenditure (REE) and total energy expenditure (TEE) were measured by indirect calorimetry (IC) and individually calibrated 24-h heart rate (HR) monitoring, respectively. Activity-related energy expenditure (AEE) and physical activity level (PAL) were calculated from TEE and REE. Fitness [assessed by O2-pulse, respiratory exchange ratio (RER) at submaximal work intensities] was determined by ergometry. The maximal isometric muscle strength of the legs (m. quadriceps, Fa max, m. ischiocruralis, Fb max) was measured by computer tensiometry. Children were grouped according to their nutritional state, AEE, O2-pulse and muscle strength. When compared with normal weight children, obese and overweight children had increased fat mass (FM), fat-free mass (FFM), waist-to-hip ratio and REE, but no group differences were observed for TEE, AEE, and PAL. Obese and overweight children spent more hours per day watching TV. After correction for body weight and FFM, no group differences in REE were observed, but normal weight children had a higher O2-pulse than overweight and obese children. By contrast, RER was increased in the latter group. The fittest group had the lowest body weight, BMI, FM and FFM. Children with a low O2-pulse spent more hours per day watching TV. Grouping children according to their degree of muscle strength, younger children (4-7.5 years) did not show group differences in nutritional state, energy expenditure, physical activity and fitness. However, in the group of 7.6- to 11-year-old children, those with the greatest muscle strength and FFM had reduced BMI, skin folds, FM and FFM. FM correlated inversely with O2-pulse, but was not associated with TEE, AEE, PAL or muscle strength. By contrast TV consumption was positively associated with FM. To summarize, overweight and obese children were less fit and watched more TV than their normal weight counterparts. FM did not correspond to TEE, AEE or PAL. Muscle strength was not associated with FM in young children, but was inversely associated with FM in older children. Our cross-sectional data are consistent with the idea that increased fitness and reduced physical inactivity may prevent children from being overweight.

No effect of gender on different components of daily energy expenditure in free living prepubertal children.

BACKGROUND: There are limited and controversial data on the influence of gender on metabolic rate in prepubertal children. OBJECTIVE: To assess the effect of gender on resting energy expenditure (REE), activity-related energy expenditure (AEE), total energy expenditure (TEE) and physical activity level (PAL) in free-living prepubertal children. DESIGN: Cross-sectional study. SUBJECTS: 40 prepubertal children (24 boys, 16 girls, 4-11 y old (mean age: 7.0 +/- 1.2 y), BMI 13.1-32.0 kg/m2). MEASUREMENTS: Energy expenditure was measured by the combination of indirect calorimetry and individually calibrated 24 h heart rate monitoring. Body composition was assessed by anthropometrics and bioelectrical impedance analysis. Socio-cultural and socio-economic factors, as well as activities of daily living, were estimated by questionnaire for the parents. Boys and girls were matched for fat-free mass (FFM, boys: 25.9 +/- 8.5 kg; and girls: 24.4 +/- 4.5 kg, n.s.) and fat mass (FM, boys: 11.6-5.9 kg; and girls: 10.8 +/- 3.3 kg, n.s.). RESULTS: We found no sex difference in REE, AEE and TEE. PAL was 1.4 +/- 0.3 for boys and 1.2 +/- 0.4 for girls. REE and TEE were significantly related to FFM (r=0.62, r=0.81, r=0.60). FFM was found to be the most significant determinant of REE (r2=0.70). REE accounted for the largest part of the variance in TEE (r2=0.46). Gender had no significant effect. CONCLUSIONS: There is no effect of gender on energy expenditure in prepubertal children.

Physical activity and diet in 5 to 7 years old children.

OBJECTIVE: To assess the possible associations between physical activity, diet, social state and overweight in children. DESIGN: Cross-sectional study on 1468 children aged between 5 and 7 years old in Kiel, northwest Germany. METHODS: Assessment of physical activity and social factors by a questionnaire, food frequency record, body composition analysis by anthropometrics and bioelectrical impedance analysis. RESULTS: 23% of our children were overweight or obese. Low levels of physical activity (as assessed by TV viewing time) were associated with increased body mass index and a higher prevalence of overweight. TV-viewing of more than 1 h per day was associated with a high consumption fast food, sweets, chips and pizza whereas fruits and vegetables were less frequently consumed. Overweight, inactivity and unhealthy eating habits were seen more frequently in families with a low social status. CONCLUSIONS: In 5 to 7 years old children, overweight is associated with physical inactivity, unhealthy eating habits and a low social status. Primary prevention efforts should be directed to low income families.

Picosecond degenerate four-wave mixing in colloidal solutions of gold nanoparticles at high repetition rates.

Time-resolved degenerate four-wave mixing experiments on a colloidal solution of 50-nm gold particles in acetone, using a high-repetition-rate laser source, are presented. The signal is found to depend strongly on the repetition rate of the incident radiation and above a frequency of 300 kHz is impossible to measure.

Bacteriophages of Saccharopolyspora erythraea.

Five bacteriophages infecting only Saccharopolyspora erythraea (formerly Streptomyces erythreus) among 43 Streptomyces spp. tested were classified into two groups by phage-host relationships, restriction enzyme mapping, cohesive-end determinations, and Southern hybridizations. phi SE6, the most frequently isolated phage, produced clear plaques on all hosts tested, while phi SE45, phi SE57, phi SE60, and phi SE69 produced turbid plaques. phi SE6 DNA was linear, had a molecular weight of (27.6 +/- 1) X 10(6) and, like the DNAs of phi SE45, phi SE57, and phi SE69, lacked cohesive ends. The characteristic patterns of of ClaI and HindIII restriction digests of phi SE6 DNA and the results of Southern hybridizations with three different ClaI fragments of phi SE6 DNA as probes indicated that phi SE6 DNA was partially circularly permuted and terminally redundant, suggesting that it was packaged by a headful packaging mechanism. Southern hybridization data also showed that phi SE45, phi SE57, and phi SE69 were closely related to phi SE6. phi SE60 DNA, in contrast, had cohesive ends, and restriction mapping plus Southern hybridization data showed that phi SE60 was unrelated to the other four phages.

Properties of the germination inhibitor of Streptomyces viridochromogenes spores.

Germinating spores of Streptomyces viridochromogenes excreted a substance into the surrounding medium which inhibited germination of another sample of the spores. The germination inhibitor (GI) was produced during submerged culture after exponential growth had ceased. The GI was purified 51-fold following extraction from growth liquor with chloroform. It was soluble in alcohol and water and had a molecular weight of less than 1000. The GI blocked growth and respiration of some Gram-positive bacteria and was an inhibitor of the membrane bound, but not solubilized, calcium-dependent ATPase of germinated spores and mycelia of the producing organism. Several sodium-potassium activated ATPases were also inhibited. All four activities (respiration, growth, germination inhibition, ATPase) co-purified during column and thin-layer chromatography. The GI activities released during germination and produced during growth were identical. A role for the GI antibiotic in regulation of dormancy of spores of the producing organism is discussed.

Cloning of genes for naphthalene metabolism in Pseudomonas putida.

Plasmid pIG7 DNA cloned in Pseudomonas putida with the broad-host-range vectors pRK290 and pKT240 expresses the genes encoding nephthalene oxidation in the presence of the intermediate substrate, salicylate, or the gratuitous inducer, anthranilate. Two operons, nahAF and nahGK, cloned from the EcoRI fragment A (25 kilobases) are under wild-type regulation by the nahR locus. Deletion plasmids provide a restriction map of both operons. Double transformants containing structural and regulatory cistron nahR in trans are used to demonstrate positive control of expression.

Role of carbon dioxide in germination of spores of Streptomyces viridochromogenes.

CO2 is required continuously during germination of Streptomyces viridochromogenes spores. Spores incubated in a defined germination medium in the absence of CO2 remain phase bright and do not release spore carbon. In the presence of CO2, the spores initiate germination accompanied by loss of refractility and spore carbon. The CO2 requirement is replaced by oxaloacetate or a mixture of tricarboxylic acid cycle (TCA) intermediates. Labeled CO2 is taken up by germinating spores, and is incorporated into protein and RNA. TCA cycle intermediates and related amino acids contain most of the acid-soluble label following short term exposures of germinating spores to 14CO2. TCA cycle inhibitors repress germination and 14CO2 uptake whereas folic acid antagonists do not. The results indicate that CO2 is incorporated into oxaloacetate which is converted to biosynthetic intermediates required for germination. Operation of the TCA cycle appears to be essential for spore germination. The conclusion is reached that CO2 is required during germination in order to maintain the cycle by an anaplerotic reaction.

Regulation of alkane oxidation in Pseudomonas putida.

We have studied the appearance of whole-cell oxidizing activity for n-alkanes and their oxidation products in strains of Pseudomonas putida carrying the OCT plasmid. Our results indicate that the OCT plasmid codes for inducible alkane-hydroxylating and primary alcohol-dehydrogenating activities and that the chromosome codes for constitutive oxidizing activities for primary alcohols, aliphatic aldehydes, and fatty acids. Mutant isolation confirms the presence of an alcohol dehydrogenase locus on the OCT plasmid and indicated the presence of multiple alcohol and aldehyde dehydrogenase loci on the P. putida chromosome. Induction tests with various compounds indicate that inducer recognition has specificity for chain length and can be affected by the degree of oxidation of the carbon chain. Some inducers are neither growth nor respiration substrates. Growth tests with and without a gratuitous inducer indicate that undecane is not a growth substrate because it does not induce alkane hydroxylase activity. Using a growth test for determining induction of the plasmid alcohol dehydrogenase it is possible to show that heptane induces this activity in hydroxylase-negative mutants. This suggests that unoxidized alkane molecules are the physiological inducers of both plasmid activities.