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Biomedical subjects

E Elam

Publications and source records attributed to E Elam.

4 recordsLinked to original sources

Visceral adipose tissue is not increased in Pima Indians compared with equally obese Caucasians and is not related to insulin action or secretion.

Pima Indians are insulin resistant and hyperinsulinaemic compared with Caucasians. We investigated whether abdominal fat distribution was different between Pimas and Caucasians and whether differences in the amount of visceral fat explained metabolic differences between the groups. Total body fat (absorptiometry) and abdominal fat distribution at L4-L5 (magnetic resonance imaging) were compared in 20 Pima Indians (10 men/10 women) and 20 age-, sex- and BMI-matched Caucasians. Insulin action was measured as glucose disposal during a two-step hyperinsulinaemic-euglycaemic glucose clamp and insulin secretion was assessed in response to oral and intravenous glucose tolerance tests. By design, percent body fat was similar in Pimas and Caucasians. Abdominal visceral and subcutaneous adipose tissue areas were also similar in the two groups (151+/-16 vs 139+/-15 cm2 and 489+/-61 vs 441+/-7 cm2 respectively). Plasma insulin concentrations were higher in Pimas than Caucasians in the fasting state (27+/-6 vs 11+/-2 mU/ml; p < 0.01) and after a 75-g oral glucose load (area under the curve 19975+/-2626 vs 9293+/-1847 mU x l(-1) x 180 min(-1); p < 0.005). Glucose disposal was lower in Pimas than Caucasians during both steps of the clamp and negatively correlated (after adjustment for percent body fat and sex) with visceral adipose tissue in Caucasians (partial r = -0.51, p = 0.03), but not in Pima Indians (r = -0.03, p = 0.92). Insulin secretion was not related to visceral fat independently of percent body fat in either group. We conclude that a relative increase in visceral fat does not explain insulin resistance and hyperinsulinaemia in Pima Indians.

Adipose Tissue↗

MR lymphography with iron oxide compound AMI-227: studies in ferrets with filariasis.

OBJECTIVE: The purpose of this study was to assess the MR lymphographic potential of AMI-227 to reduce the signal intensity of hyperplastic inflammatory lymph nodes by using ferrets with filariasis as the animal model. Both interstitial and IV modes of administration were studied. MATERIALS AND METHODS: Twelve ferrets were infected with the filaria Brugia malayi and six control ferrets were injected with super-paramagnetic iron oxide AMI-227, either interstitially or IV. Signal intensities of the left popliteal lymph node, left hamstring muscle, and left inguinal fat were measured before, 48 hr after, and up to 138 days after contrast injection with the use of both spin-echo and gradient-echo techniques. The signal intensity data were statistically analyzed. The lymph nodes, liver, spleen, and lungs were studied with light and electron microscopy. RESULTS: Forty-eight hours after the interstitial injection of AMI-227, the signal intensities of the ipsilateral popliteal nodes of the infected and control ferrets were significantly reduced (p less than .0005) without significant changes in the signal intensities of the surrounding tissues on both spin-echo and gradient-echo MR images. No nodal signal reduction occurred with the IV route of injection in ferrets. Light microscopy revealed iron to be localized within nodal marginal zones exclusively. Lymphatic trunks were visualized after interstitial injection. Signal reduction persisted to our end point at 138 days. CONCLUSION: AMI-227 shows regional specificity with significant enhancement of nodal structures and demonstrates potential as an interstitial MR lymphographic agent.

Animals↗

Quantification of anterior translation of the humeral head in the throwing shoulder. Manual assessment versus stress radiography.

Clinical evaluation of humeral head translation relies mainly on manual tests to measure laxity in the human shoulder. The purposes of this study were to determine whether side-to-side differences exist in anterior humeral head translation in professional baseball pitchers, to compare manual laxity testing with stress radiography for quantifying humeral head translation, and to test intrarater reliability of the manual humeral head translation and stress radiography tests. Twenty professional baseball pitchers underwent bilateral manual anterior humeral head translation and stress radiographic tests. Stress radiography was performed by imparting a 15-daN anterior load to the shoulder in 90 degrees of abduction with both neutral and 60 degrees of external rotation and recording the glenohumeral joint translation at rest and under stress in each position. Eight subjects were retested to assess the reliability of these methods. Results showed no significant difference between the dominant and nondominant extremity in the amount of anterior humeral head translation measured manually and with stress radiography, nor significant correlation between anterior humeral head translation measured manually and by stress radiography. Test-retest reliability was moderate-to-poor for the manual humeral head translation test and moderate for stress radiography.

Adolescent↗