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Biomedical subjects

K Harmon

Publications and source records attributed to K Harmon.

6 recordsLinked to original sources
PubMed1996

Changes in bone mineral content in male athletes. Mechanisms of action and intervention effects.

OBJECTIVES: To determine changes in bone mineral content (BMC) in male athletes, to examine the mechanisms of changes, and to evaluate the effects of intervention. DESIGN: Dual-energy x-ray absorptiometry (DEXA) tests were administered over a 2-year period, and calcium loss during training was determined by analysis of sweat and urine. Calcium supplementation was administered during year 2. SETTING--A midsouth university. PARTICIPANTS: Eleven members of a college Division I-A basketball team. INTERVENTION: Based on observed calcium loss, athletes received differential levels of calcium supplementation. Intervention commenced the week prior to the fall training season and continued through postseason play. MAIN OUTCOME MEASURE--Changes in BMC. RESULTS: Total body BMC decreased 3.8% from preseason to midseason of year 1 (mean decrease, 133.4 g, P = .02), increased nonsignificantly by 1.1% (mean increase, 35.3 g, P = .22) during the offseason, but decreased an additional 3.3% during summer months when practices resumed (mean decrease, 113.1 g, P = .01). Dermal calcium loss averaged 247 mg [corrected] per training session. From preseason to late summer, there was an overall decrease of 6.1% in total BMC and a 10.5% decrease in BMC of the legs. Calcium supplementation was associated with significant increases in BMC and lean body mass. CONCLUSIONS: Bone loss is calcium related and exercise is positively related to BMC provided that calcium intake is sufficient to offset dermal loss.

Absorptiometry, Photon↗
PubMed1996

Effects of ingesting supplements designed to promote lean tissue accretion on body composition during resistance training.

This study examined the effects of ingesting nutritional supplements designed to promote lean tissue accretion on body composition alterations during resistance training. Twenty-eight resistance-trained males blindly supplemented their diets with maltodextrin (M), Gainers Fuel 1000 (GF), or Phosphagain (P). No significant differences were observed in absolute or relative total body water among groups. Energy intake and body weight significantly increased in all groups combined throughout the study with no group or interaction differences observed. Dual energy x-ray absorptiometry-determined body mass significantly increased in each group throughout the study with significantly greater gains observed in the GF and P groups. Lean tissue mass (excluding bone) gain was significantly greater in the P group, while fat mass and percent body fat were significantly increased in the GF group. Results indicate that total body weight significantly increased in each group and that P supplementation resulted in significantly greater gains in lean tissue mass during resistance training.

Absorptiometry, Photon↗
PubMed1989

The role of ceroid in lung and gastrointestinal disease in Hermansky-Pudlak syndrome.

Studies of ceroid associated lesions in Hermansky-Pudlak syndrome (HPS) indicate that restrictive lung disease and granulomatous gastrointestinal lesions are among the most frequent and account for 60% of the deaths of the patients. No defects in the immune system in HPS were found. Histological, ultrastructural and chemical studies show accumulation of non-biodegradable ceroid in tissue cells and associated macrophages of HPS patients. There is no known degradative pathway for ceroid. Ceroid is eliminated from cells by exocytosis. Wild type and pale eared mice treated with leupeptin, which inhibits exocytosis, accumulate ceroid in organ cells in the same sequence seen in HPS. Young HPS patients without significant pulmonary function deficits were lavaged, the macrophages examined by TEM and tested for platelet derived growth factor. Macrophages contained ceroid and 7/12 patients had 27 +/- 42 units of PDGF bioactivity compared to zero activity in controls. Purified ceroid was fed to macrophages lavaged from the lungs of non-smoking control subjects. Prior to feeding, less than 5% of cells contained one or two small yellow-orange autofluorescent granules resembling ceroid. After feeding, approximately 20% of control cells had ingested ceroid, but PDGF was not increased. The immunologic and histologic studies and the production of PDGF by macrophages which precedes lung fibrosis all point to a central role of the macrophage in these lesions. These studies did not distinguish whether the macrophages ingested ceroid from other cells, or whether ceroid is produced intrinsically by the HPS macrophage.

Adolescent↗