In vivo determination of body fat by measuring total body carbon

Total body carbon (TBC) is measured in vivo by neutron inelastic scattering. The fast neutrons needed for the irradiation are produced by a miniature deuterium-tritium (D-T) neutron generator. Body fat and protein are the main contributors to TBC. Bone ash and carbohydrates contribute less than 3%. Fat is calculated from TBC after the subtraction of the carbon contributions from protein, bone, and glycogen. The technique was applied to 14 normal volunteers (8 females, 6 males) aged 24-94 y who underwent neutron inelastic scattering and neutron activation measurements for body carbon, nitrogen, and calcium. The initial results agree with other techniques. Unlike models that evaluate body fat by subtracting lean body mass from body weight, the TBC technique is not sensitive to assumptions on the composition of lean body; therefore, it is appropriate for studies of adults of any age and health condition.     

Physical-activity-assessment measures compared in a biethnic rural population: the San Luis Valley Diabetes Study

We evaluated the consistency of three questionnaire methods of assessing work and leisure activity in the rural biethnic population of the San Luis Valley Diabetes Study. A 7-d physical activity recall (PAR), a ranking of usual activity, and a history of usual participation in vigorous activity were used. Energy expenditure (kJ.kg-1.wk-1) (EE) was estimated from PAR. Subjects were 503 adults [49% non-Hispanic white (NHW), 51% Hispanic]. Physical activity at work rather than leisure-time activity largely determined total energy expenditure. Average EE at work increased with work rank for all subjects combined [mean EE (SEE) for rank 1 (low) = 324.2 (24.4), rank 4 (high) = 874.0 (102.1)] and within sex, ethnic, and occupational subgroups. Leisure EE increased with leisure rank only for NHW men and employed women. Similar patterns were observed in comparisons of PAR data with history of vigorous activity. Further development and validation of instruments appropriate for use across population subgroups are needed.     

Basal and metoclopramide-stimulated prolactin (PRL) serum levels in users and non-users of a copper intrauterine device (TCu-380 IUD).

The study was undertaken to analyze the basal and metoclopramide-stimulated serum PRL levels in healthy parous women users (group 1, n = 12) and non-users (group 2, n = 12) of a TCu-380 IUD. All women had regular menses and were studied between days 18 to 22 of their cycle; none had lactated nor regularly ingested any type of medication during the last six months. After a 10-12 hour overnight fast, peripheral venous blood samples were obtained through an indwelling catheter at -30, -15 and 0 minutes and at 60, 90 and 120 minutes after oral metoclopramide (10 mg). There were no significant differences in serum PRL between both groups, in basal levels nor throughout the test, whether analyzing the mean values at each sampling time, the sum of PRL levels from 60-120 minutes, or the peak levels. No correlation was observed between PRL levels and any of the clinical or obstetric characteristics of the women in both groups. Serum progesterone was greater than or equal to 4.0 ng/ml in all women. Thus, the use of alpha TCu-380 IUD did not induce any significant changes in basal nor in stimulated serum PRL levels.     

Patient-controlled analgesia. Does a concurrent opioid infusion improve pain management after surgery?

OBJECTIVE.--To assess the influence of a continuous (basal) morphine infusion as part of a patient-controlled analgesia (PCA) system on the postoperative analgesic requirement and on recovery parameters following abdominal hysterectomy. DESIGN.--Single-center, randomized, controlled protocol. SETTING.--University medical center. PARTICIPANTS.--A total of 230 adult women were randomly assigned to receive no morphine infusion (control group) or a continuous 0.5-, 1.0-, or 2.0-mg/h morphine infusion. Each patient was able to self-administer supplemental intravenous bolus doses of morphine (1 to 2 mg) using a PCA infuser. MAIN OUTCOME MEASURES.--Use of the PCA device, opioid-related side effects, recovery times, and the patients' assessment of pain and sedation on linear visual analog scales were recorded during the 72-hour study period. Follow-up questionnaires were completed by the patients and their health care professionals to assess the overall adequacy of PCA therapy. RESULTS.--Patients who received the 2-mg/h morphine infusions received significantly more opioid medication 9 to 72 hours after their operation than those who received no infusion (control group). The presence of a continuous morphine infusion of 0.5 to 2 mg/h did not significantly decrease the number of patient demands or supplemental bolus doses administered compared with the control group. Overall, 168 (84%) of the 199 patients who completed the 72-hour study were able to achieve adequate analgesia without requiring changes in the PCA regimen or experiencing major side effects. Recovery times and outcome variables were similar in all four groups. CONCLUSION.--The routine use of a continuous opioid infusion in combination with a standard PCA regimen does not improve pain management compared with PCA alone after abdominal hysterectomy.     

The effect of diaper type and overclothing on fecal contamination in day-care centers

Fecal coliform contamination of environmental surfaces and hands in the day-care center is common. This study evaluated the effect of two diaper types on fecal contamination. Ten rooms in four day-care centers containing 141 children were studied in a prospective, randomized, crossover study. A total of 2946 samples were cultured during the 9-week study. Fecal coliforms were isolated from 307 inanimate objects (15%), 73 toy balls (46%), and 131 hands (17%). The number of contaminated inanimate objects was significantly less in rooms where paper diapers were worn when compared with that in rooms where double cloth diapers with plastic overpants were worn and in rooms where clothes were worn over diapers. Inanimate object cultures had more contamination in rooms in which diarrhea had occurred. Containment of feces by overclothes and diaper type may be important in decreasing transmission of enteric pathogens in day-care environments.     

Obesity: determinants and therapeutic initiatives.

There are several possible determinants of obesity, including impaired thermogenesis and the differential utilization of fuels in different tissues. Whereas hypometabolism may initiate obesity in some people, once obese, individuals tend to manifest a higher resting metabolic rate because of their greater fat-free mass, exhibit an impaired thermic response to food, and expend more calories than lean individuals for equivalent amounts of activity. As a result, over a 24-h period, obese people generally expend more energy than lean people. A second determinant of obesity is related to fuel utilization and suggests that those predisposed to be obese may have an innate insulin resistance in muscle, leading to decreased uptake, oxidation, and storage of glucose in this tissue. As a result, the glucose is shunted to adipose tissue, where it is stored. With regard to treatment of obesity, emphasis on increased energy expenditure through the inclusion of reasonable amounts of activity is essential. However, this must always be combined with restraint in caloric intake.