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Biomedical subjects

L Greenwood

Publications and source records attributed to L Greenwood.

14 recordsLinked to original sources
PubMed2000

Seasonal variations and maturity stages in relation to differences in serum levels of gonadal steroids, vitellogenin, and thyroid hormones in the common dentex (Dentex dentex).

Seasonal variations in serum concentrations of 17beta-estradiol (E(2)), vitellogenin (Vg), testosterone (T), 11 ketotestosterone (11-KT), and thyroid hormones (T(4), l-thyroxine; and T(3), 3,5, 3'-triiodo-l-thyronine) were investigated during the first, second, and third reproductive cycles in intensively reared populations of common dentex, Dentex dentex, and correlated with gonadal development and spawning. In females, there were baseline E(2) values (<0.10 ng/ml) and negligible Vg concentrations during the postspawning and pregametogenesis period (June to December), and these increased thereafter to peak during the spawning period. Maximum T(3) and T(4) serum concentrations were found around spawning. There was a positive correlation during vitellogenesis and final maturation between Vg and T(3) (r(2) = 0.366). In addition, Vg and T(3) concentrations were statistically higher in the stages of vitellogenesis and final maturation than at the other stages (P<0.001). Minimum T(3) and T(4) concentrations (October) coincided with the decrease in water temperature and the associated decrease in the daily feeding rate and the specific growth rate. In males, as in females, seasonal changes in serum levels of T and 11-KT were well correlated with gonadal development. The presence of males in the stage of completed spermiogenesis in December coincided with the surge in both androgens and this increase lasted until the end of the spawning period. There were no significant differences in serum T(3) and T(4) levels among the maturity stages. The observed seasonal changes in serum gonadal steroids and Vg reflected the pattern of oocyte development and the spawning behavior of common dentex and were typical of the patterns described in most multiple spawners studied to date. Thyroid hormones may enhance early ovarian development and stimulate vitellogenesis in female dentex.

Aging↗
PubMed2000

Creatine supplementation patterns and perceived effects in select division I collegiate athletes.

OBJECTIVE: To describe patterns of creatine use in select Division I collegiate athletes based on recommended dosages according to body weight. Further, to report the perceived effects noted with creatine supplementation. DESIGN: Anonymous open-ended self-report descriptive questionnaire. SETTING: National Collegiate Athletic Association Division I institution. PARTICIPANTS: Two-hundred and nineteen male and female collegiate athletes representing eight varsity sports. MAIN OUTCOME MEASURE(S): An open-ended questionnaire was administered to determine patterns of creatine use during the loading and maintenance phases of this nutritional supplement. In addition, perceived positive, negative, and no effects associated with creatine usage patterns were determined from athlete responses on this self-report measure. RESULTS: Considering this select group of collegiate athletes, highly variable patterns of creatine supplementation were noted for loading/maintenance phases based on recommended dosages/days and body weight. Of the 219 athletes surveyed, 90 (41%) reported using creatine, while creatine supplementation was more prevalent among men than women. Creatine users (80 athletes, 89%) reporting perceived positive effects were primarily at or below recommended dosages for the loading phase but above recommended dosages in the maintenance phase. Creatine users (34 athletes, 38%) reporting perceived negative effects were primarily at or below recommended dosages in the loading phase but noticeably above recommended dosages in the maintenance phase. Ironically, all creatine users who reported negative side effects also reported positive effects. Creatine users (10 athletes, 11%) reporting no effects were below recommended loading dosages but above recommended maintenance dosages. CONCLUSIONS: The perceived positive effects noted support current research (strength/weight gains), while the perceived negative effects (cramping/gastrointestinal distress) were consistent with anecdotal reports surrounding creatine supplementation. Apparently, collegiate athletes in this study are in need of education regarding the proper use of creatine supplementation. Additional studies are needed to ascertain creatine supplementation patterns of collegiate athletes in various settings.

Adolescent↗
PubMed1999

The effect of photoperiod on diel rhythms in serum melatonin, cortisol, glucose, and electrolytes in the common dentex, Dentex dentex.

Diel rhythms in serum concentrations of melatonin, cortisol, glucose, sodium, chloride, and potassium were studied in the common dentex, Dentex dentex, under different photoperiods (DD, 8L:16D, 12L:12D, 16L:8D). Photoperiod affected both the diel rhythms and the absolute values of the estimated blood components. Regardless of the photoperiod, melatonin titers were elevated during the scotophase (384.3 +/- 13.9 pg/ml) compared with a mean baseline level of 54.4 +/- 2.7 pg/ml during the photophase. Serum melatonin concentrations reflected the prevailing photoperiod and constantly elevated melatonin levels with no diel rhythmicity were evident in fish held in the DD protocol. A circadian-like pattern in serum cortisol was observed in fish that were kept at the DD and 8L:16D protocols with cortisol peak at 18:00 h in the night. Fish exposed to the 16L:8D regime showed highest cortisol levels at 10:00 h, while no rhythmicity was evident under the 12L:12D protocol. A phase shift of 4 h between the peaks of cortisol and glucose was evident in fish exposed to the DD, 8L:16D, and 12L:12D regimes. Diel patterns of changes in serum Na+ and Cl- were observed only in the fish held in the DD protocol. Serum K+ values were lowest during the first part of the scotophase under all regimes, except the 16L:8D where no diel rhythmicity was detected. During the photophase, cortisol was positively correlated with glucose, Na+, and Cl- and negatively with K+. During the scotophase, melatonin was positively correlated with glucose and electrolytes. Results indicated that cortisol may be responsible for the observed rhythmicity of glucose and that melatonin may play a role in glucose and ion regulation in common dentex.

Animals↗
PubMed1990

The effects of topical fluticasone propionate on allergen-induced immediate nasal airways response and eosinophil activation: preliminary results.

Nasal application of grass pollen allergen in atopic individuals with seasonal rhinitis leads to an early rise in nasal airways resistance. The effects of fluticasone propionate, a powerful, topically active glucocorticosteroid, on nasal airways resistance and cellular infiltration of the nasal mucous membrane were investigated. Fluticasone propionate blunted the rise in nasal airway resistance following allergen challenge (P = 0.089). Although this glucocorticosteroid did not affect the total number of eosinophils in biopsies of nasal mucous membrane, the number of activated eosinophils was significantly reduced (P less than 0.05).

Administration, Topical↗
PubMed1978

Effect of selenium-vitamin E on adriamycin-induced cardiomyopathy in rabbits.

Administration of selenium-vitamin E (Se-E) to weanling rabbits chronically treated with adriamycin (ADR) resulted in decreased incidence and severity of cardiomyopathy and decreased cumulative mortality during a 10-week experiment. However, Se-E did not protect against extracardiac lesions or against a number of clinicopathologic alterations induced by chronic ADR toxicosis. Histopathologic alterations of ADR-induced cardiomyopathy were concentrated periarterially in the free and septal walls of the left ventricle. Initial vacuolar degeneration of injured cardiac muscle cells was followed by myofibrillar lysis and eventual cell death with subsequent interstitial fibrosis. Ultrastructurally, degenerated cardiac muscle cells had 3 prominent alterations: (1) sarcoplasmic vacuolization caused by distention of elements of sarcoplasmic reticulum and T-tubules, (2) degeneration of mitochondria forming large myelin figures from disrupted membranes, and (3) lysis of myofibrils producing granular sarcoplasmic masses. Severely injured fibers were necrotic and macrophages invaded to remove cellular debris. The interstitium was distended by edema and increased amounts of collagen. Extracardiac lesions in rabbits with chronic ADR toxicosis included the usually recognized alterations involving cell-renewal systems in kidney, testis, bone marrow, skin, and alimentary tract, as well as vacuolar degeneration of skeletal muscle and focal loss of pancreatic tissue, with ensuing pancreatic fibrosis and fat necrosis. Deaths in ADR-treated rabbits usually were precipitated by terminal septic embolism. The partial protection afforded by Se-E against ADR-induced cardiomyopathy may be associated with stabilization of the membranes of injured muscle cells or with prevention of ADR-induced inhibition of coenzyme Q10-dependent mitochondrial enzymes.

Alopecia↗
PubMedDate not supplied

Public outbreak.

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Aged↗
PubMedDate not supplied

Radiographic evaluation of the soap man mummy.

This article describes how mobile radiography was used to examine a mummified cadaver exhumed in 1875 and stored in the Smithsonian Museum. Radiographs revealed artifacts imbedded in the cadaver, indicating 1824 as the earliest possible interment. Through radiographic assessment of the skeleton, researchers were able to approximate the individual's age at death. In addition, evidence of pathology, possibly ideopathic skeletal hyperostosis, suggested the individual may have been employed in manual labor. The radiographs, when compared to x-rays of another cadaver exhumed at the same time and place, refuted information in museum records.

Adipose Tissue↗