Search PubMed⌕ Search

Biomedical subjects

M W Sharp

Publications and source records attributed to M W Sharp.

At least 19 recordsLinked to original sources
PubMed1998

Does erythrocyte infusion improve 3.2-km run performance at high altitude?

The effects of autologous erythrocyte infusion on improving exercise performance at high altitude have not previously been studied. The effects of erythrocyte infusion on 3.2-km (2-mile) run performance were evaluated during 3 days (HA3) and 14 days (HA14) exposure to high altitude (4300 m) in erythrocyte-infused (ER) and control (CON) subjects that were initially matched (P>0.05; n = 8 in each group) for age, body size and aerobic fitness. After sea-level runs (SL; 50 m), unacclimated-male subjects received either 700 ml of saline and autologous erythrocytes (42% hematocrit; ER) or saline alone (CON). The 3.2-km run times (min:s) did not differ (P>0.05) between groups at SL [mean (SEM) ER, 13:14 (00:19); CON, 13:39 (00:32)] or during HA3 [ER, 19:02 (00:18); CON, 19:44 (00:43)] and HA14 [ER, 17:44 (00:27); CON, 18:45 (00:55)] but times were slower (P<0.05) when comparing HA3 or HA14 to SL. Heart rates (HR) did not differ between groups at SL [ER, 188 (3) beats x min(-1); CON, 191 (3) beats x min(-1)], or during HA3 [ER, 170 (4) beats x min(-1); CON, 178 (4) beats x min(-1)] and HA14 [ER, 162 (6) beats x min(-1); CON, 169 (5) beats x min(-1)], but HR were lower (P<0.05) when comparing HA3 or HA14 to SL. Ratings of perceived exertion (local, central, and overall ratings) did not differ between groups at SL, HA3 or HA14, but local ratings were higher (P<0.05) at HA3 and HA14 compared to SL, and overall ratings were higher for HA3 than SL. Analysis of covariance (adjusted for SL group run times) revealed (min:s) 00:14 (HA3) and 00:28 (HA14) mean improvement tendencies (P>0.05) for ER compared to CON. Thus, no significant improvements in 3.2-km run performance were associated with erythrocyte infusion, although the ER group showed a tendency to run slightly faster at high altitude.

Acclimatization↗
PubMed1990

Infrared thermographic measurement of circulatory compromise in trenchfoot-injured Argentine soldiers.

Passive rewarming of a cold-water stressed foot was evaluated in 33 recovered trenchfoot (TF) patients and 15 uninjured men. Infrared images were recorded prior to immersion, immediately following, and at 1-min intervals for 20 min. Individual baseline temperature (IBT) recovery was used to separate subjects into three groups designated Good and Poor Rewarming Controls (GRC and PRC) and Injured Subjects (Inj Sub). IBTs were significantly less (p less than 0.01) for Inj Sub compared to both GRC and PRC while no difference existed between GRC and PRC. This relationship changed when slopes of and areas under the mean rewarming curves were compared. Both these criteria were significantly greater (p less than 0.01) for GRC than for PRC and Inj Sub, while no difference was noted between PRC and Inj Sub. It could not be determined if the poor response of Inj Sub was inherent or a result of injury. We conclude that previously injured subjects and nearly 60% of a normal population may be at significant risk for cold injury.

Argentina↗
PubMed1988

Digital dermatitis in dairy cattle.

A condition of digital dermatitis causing lameness in a dairy herd is described. The lesion was a small circumscribed area of epidermal inflammation in the skin immediately above the coronet between the bulbs of the heel. Topical treatment, consisting of excoriation and application of a gentian violet and tetracycline aerosol spray, was effective. Although the high incidence and rapid onset of the condition suggested an infectious cause, no organism was isolated consistently.

Animals↗
PubMed1986

The cost of Border disease infection in a commercial flock.

The performance of a flock of 203 crossbred ewes on a lowland farm was examined. Before lambing the ewes were run in two groups (A and B). Group A (124 ewes) produced significantly fewer marketable lambs as a consequence of neonatal and later losses. The associated clinical features were consistent with Border disease infection and the presence of the virus was demonstrated. These features were not evident in the progeny of group B (79 ewes). The market sale returns of both groups of sheep were compared and the flock performance was contrasted with that of the two previous years. The outbreak of Border disease resulted in a potential reduction of income in excess of 20 per cent. Such a loss supports the necessity for an effective control strategy for Border disease.

Animals↗
PubMed1984

Bovine virus diarrhoea-mucosal disease virus-induced fetopathy in cattle: Efficacy of prophylactic maternal pre-exposure.

Maternal immunity was produced in Jersey heifers by exposing them to bovine virus diarrhoea-mucosal disease virus before conception. In the following pregnancy this immunity protected the fetuses from transplacental infection arising from challenge of the dams at 100 days gestation with homologous virus. Unprotected Jersey heifers showed a high incidence of death and fetal intrauterine growth retardation associated with transplacental viral infection. Functional normality of the locomotor system was assessed retrospectively from ciné films of each calf after birth, and scored for each of an overlapping series of clinical signs. The progeny of non-immune dams scored significantly lower than calves from the vaccinated heifers.

Animals↗