John E. Christian

RELATIONSHIPS BETWEEN PHYSICAL PERFORMANCE ITEMS AND BODY COMPOSITION.

Abstract The purpose of the study is: (a) to determine the relationships between body composition and physical peformance and related items; and (b) to determine whether or not certain physical performance and related items might be useful in estimating body composition in terms of total lean body mass and percent lean body mass as measured by potassium-40 determinations in adult men. Data on 19 physical performance items were obtained from 40 subjects between 21 and 57 years of age. The results are of value to researchers in general and researchers in physical education in particular for estimating gross body composition using certain physical performance items.

Body composition: relative in vivo determinations from potassium-40 measurements.

Measurements of body composition from serial, in vivo determinations of potassium-40 were made on 51 obese human subjects who were placed on a low calorie diet. Weight losses in the group averaged from 12 to 36 pounds. There was no change in potassium content or in lean body weight. Weight loss resulted from the loss of excess body fat.

A 2π liquid scintillation counter for determining the radioactivity of large samples including man and animals

Abstract The design and operating characteristics of a 2 π large-volume liquid scintillation counter are described. The counter is used for measuring natural and tracer amounts of added radioactivity in people, animals and large samples. The detector tank, containing more than 90 gal of scintillator solution, is mounted in a horizontal position and is shielded by 6 in. of steel. The tank has a semicircular center well in which the samples are placed. This well is 72 in. long and has a 20-in. diameter. Six 16-in. dia. photomultiplier tubes provide good light collection efficiency. A conveyor system permits rapid and convenient loading and unloading of samples. The counter is currently being used to count Cs 137 and K 40 simultaneously. The counting efficiency for a Cs 137 point-source is 30.5 per cent with an average background of 13,300 counts/ min, and the counting efficiency for a 3.32 kg potassium chloride standard is 18.6 per cent with an average background of 8600 counts/min. The natural K 40 level in humans can be determined with an error of less than 2.5 per cent in a counting time of 4 min.

A large-volume 4π liquid scintillation detector

Abstract This detector has a scintillator volume of 1 ft. 3 and a sample chamber 4 1 4 in. in diameter and 8 in. long. Four 5 in. photomultiplier tubes give a photocathode coverage of about 10 per cent of the detectors wall area. Good light collection efficiency results in the counter being relatively insensitive to source position in the sample chamber. The detector is housed in an iron shield providing 5 in. of shielding. Such detectors as the one described should find wide application, particularly in biological studies and clinical diagnosis.

The hepatotoxic potential of combined toluene-chronic ethanol exposure

The hepatotoxic properties of concurrent chronic oral ethanol ingestion and acute toluene inhalation were evaluated. Male rats were maintained on ethanol-containing or control liquid diets for 29 days. Animals of each group were subjected to five 20-min exposures to 10 000 ppm toluene with 30 min of room air inhalation between exposures on days 22, 24, 26, and 28 of liquid diet feeding. Some of the ethanol-fed animals were withdrawn from ethanol 14 h before exposure. Ethanol-withdrawn animals displayed an increased sensitivity to the narcotic action of toluene. Animals were sacrificed and assays performed on day 29. Stress markers (plasma corticosterone, free fatty acid, and glucose) were not affected by treatments. A modest elevation in plasma aspartate aminotransferase occurred in non-withdrawn animals receiving both ethanol and toluene. Ethanol-toluene exposure increased both relative liver weight and liver triglycerides. Toluene antagonized the hypertriglyceridemia associated with chronic ethanol ingestion. This study indicates that combined ethanol and toluene exposure has minor potential to induce acute liver injury, but results in altered deposition of hepatic triglycerides.

Thin-layer chromatography of DDT and some related compounds on aluminum oxide chromatoplates

Abstract The chromatographic behavior of DDT and fourteen related compounds, metabolites, analogs, and degradation products on commercially available pre-coated aluminum oxide thin-layer chromatoplates was investigated using thirty-three solvent systems. The color and/or fluorescence response of the DDT-type compounds and their sensitivity to a chromogenic reagent consisting of ammoniacal silver nitrate and 2-phenoxyethanol in acetone is discussed. A total of eleven compounds of the mixture were separated by two-dimensional thin-layer chromatography on aluminum oxide plates.

BODY COMPOSITION OF CALVES AND PIGS MEASURED BY LARGE VOLUME LIQUID SCINTILLATION COUNTING AND CONVENTIONAL CHEMICAL ANALYSES

Measurement of body composition in the live animal by nondestructive means has been the objective of animal scientists and human physiologists for many years. Use of the large volume liquid scintillation counter to determine lean or fat content of swine was reported (S . E. Zobrisky et al., 1959) as promising. Scintillation counting of calves up to 200 lb. has been recently reported (E. G. Stant, Jr. et al., 1962). More detailed studies have been completed on lambs. Correlations of -0.73 to -0.79 between grams potassium per kilogram live lamb and per cent separable fat (A. H. Kirton et al., 1961) and -0.72 to --0.89 between K40 count per minute per pound and per cent excess fat (M. D. Judge et al., 1962) have been reported. Correlations between K40 determinations of the live lamb and per cent lean or per cent edible portion by the two groups cited above yielded positive correlations ranging from 0.01 to 0.75. The former group found a lower relationship between carcass potassium and per cent carcass fat while the latter group found a slightly higher relationship between carcass potassium and per cent carcass fat. Chemical analyses of swine carcasses (A. H. Kirton et al., 1962) for potassium and sodium have confirmed the greater predictive value of potassium in that 0.21 per cent of the carcass was potassium and the potassium concentration was correlated 0.82, -0.83, and 0.71 with per cent water, per cent ether extract, and per cent protein respectively. Body compartment contributions to composition of swine ( R. H. Gnaedinger et d., 1962) have shown that the whole animal contains 49.03 per cent water, 33.00 per cent fat, 13.69 per cent protein, and 2.27 per cent ash at approximately 200 lb. weight. Ninety per cent of the fat was found in the carcass. Correlations of potassium content with lean content, protein content, and fat content of pork hams and beef rounds have been reported (R. Kulwich et al., 1961a and 1961b) to have an absolute value ranging from 0.69 to 0.98. All relationships found between potassium concentration and fat were negative, while those found between potassium concentration and lean or protein were positive.

A 4π liquid-scintillation whole-body counter—I. Design, operating characteristics, and calibration☆

Abstract A 4π large volume liquid-scintillation counter composed of two 2π detector tanks is described. This counter is used primarily for measuring 40 K activity in human beings and large animals.

SURFACE PHENOMENA RELATED TO ODOR MEASUREMENTS

The importance of an objective niethod of odor measurement is well recognized. Such a technique would eliminate physiological and psychological factors present, very prominently, in subjective test methods. An objective method of measurenient which would permit quantitative and qualitative measurements would be of great value, particularly if it permitted measurements below the threshold level of the human nose. In-

In vivo determinations of lean body mass from K40 measurements and the relationship of these values to motor aptitude in preadolescent boys

Abstract The in vivo determination of lean body mass from measurements of K40 in a 2π liquid scintillation counter is described. Measurements were made on 81 boys, between 9 and 13 years of age, who were participating in a youth fitness program. The results, expressed in terms of lean body mass in kilograms and percentage of total body weight, were compared with 38 test items selected to measure motor aptitude. The factor—analysis technique was utilized to identify the factors which could explain the items measuring body composition and motor aptitude. Factor I, in which the percentage lean body mass is the most important item, was designated as the “Body Fitness Factor” and Factor II in which lean body mass is a very significant factor was designated as the “Growth and Maturity Factor”. The technique described for the determination of body composition is applicable to studies of the effect of physical fitness states, age, different levels of nutrition, drugs, disease, and other factors on potassium levels, lean body mass and body fat of large animals and human subjects.