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.     

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.     

Idiopathic retroperitoneal fibrosis. A retrospective analysis of 60 cases

Sixty patients with idiopathic retroperitoneal fibrosis presenting between 1965 and 1984 are reviewed. Their mean age at presentation was 56 years and the male:female ratio was 3:1. The commonest presenting symptoms were flank and abdominal pain, weight loss, nausea and polyuria. Physical examination was usually normal, expect for the presence of hypertension. Anaemia and elevation of erythrocyte sedimentation rate were usually present. Proteinuria was found in less than a third of patients at presentation and significant bacteriuria was uncommon. The correct diagnosis was made or suspected in very few patients before referral. The cumulative actuarial survival rate was 86% at 1 year and 78% at 2 years. Seventeen patients died; they were significantly older and more uraemic at the time of referral than those who survived. A few patients did well with either corticosteroid therapy or ureterolysis alone. In the majority, both operation and steroid treatment were necessary. In bilateral obstruction with residual function in both kidneys, bilateral ureterolysis proved superior to unilateral operation (each followed by steroid therapy) in conserving renal function. Operation alone or steroid therapy alone should be considered in cases where steroids or surgery respectively present particular hazards. The less traumatic unilateral operation should be considered in poor risk patients and in those whose renal function is absent on one side. In many survivors, disease activity has persisted for many years. Life-long follow-up is recommended.