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Biomedical subjects

J O'Shea

Publications and source records attributed to J O'Shea.

15 recordsLinked to original sources
PubMed1992

Fitness profiles and activity patterns of entering college students.

Fitness levels of American youth have shown a marked decline in the last decade, according to recent studies. To determine whether such a tendency persists for entering college students, the authors evaluated 115 male and 143 female students for performance on the following fitness-related variables: (1) maximal oxygen consumption (estimated from Astrand cycling protocol), (2) body composition (skin-fold techniques), (3) muscle endurance (sit-up protocol), (4) muscle strength (bench-press protocol), and (5) joint flexibility (upper and lower body protocols). Although neither men nor women exhibited high levels of cardiorespiratory fitness, the women in the study showed higher relative levels than their male counterparts. Both groups showed excellent levels of muscle strength (compared with normative standards), but they achieved only an average standard for muscle endurance. Findings of relatively low levels of cardiovascular fitness compared with levels of muscle strength, particularly in men, seem to be a reflection of an inappropriate concentration of physical activity.

Adolescent↗
PubMed1992

Role of basal release of nitric oxide on coronary flow and mechanical performance of the isolated rat heart.

1. The role of nitric oxide (NO) in the regulation of coronary flow and mechanical function was studied in isolated working rat hearts. 2. The inhibition of basal release of NO by L-Ng-monomethylarginine (L-NMMA; 500 microM), a specific inhibitor of its synthesis, induced a reduction of coronary flow to 39.1% (+/- 3.4) of its basal level. 3. Associated with this was a drop of cardiac output to 58.10% (+/- 5.42) of control values. 4. This mechanical dysfunction, which was more pronounced in hypertrophied hearts, appears to be related to ischaemia, as it was prevented by simultaneously administered glyceryl trinitrate. Furthermore, L-NMMA did not alter the contractile activity of isolated cardiac myocytes, thereby excluding a direct toxic effect. 5. These findings provide evidence that NO plays a crucial role in the maintenance of basal coronary flow and appears to be essential for sustaining mechanical activity.

Animals↗
PubMed1987

Prophylaxis of trichostrongylid infection afforded by low-dose phenothiazine given in two successive years to first-season calves on a common area of pasture.

Reduced trichostrongylid infection on herbage and in calves was obtained when first-season calves, grazing a common area of pasture, received low-dosage phenothiazine (PTZ) in two successive years. The average daily dose of PTZ was 7.0 or 10.3 mg kg-1 in the first year and, in the second, between 5.0 and 7.0 mg kg-1. The effect on herbage infection was attributed mainly to ovicidal action. Treatment increased weight gain by 22 and 50 to 60 per cent in the respective seasons. The results suggested a cumulative effect produced by treating calves of successive years. Two calves developed PTZ-induced photosensitivity (corneal opacity) in the first season, and two calves in the second season but in the latter, severe bronchopneumonia was believed to be a predisposing factor. To avoid photosensitivity and still maintain adequate drug activity, the daily intake of PTZ should probably be restricted to around 6 mg kg-1.

Administration, Oral↗
PubMed1986

Extragenital donovanosis: three cases from Western Australia.

Three unusual cases of extragenital donovanosis are described. The presenting features were ulceration of the anterior abdominal wall, discharging sinuses of the neck, and an abscess of bone, respectively. Two cases were diagnosed recently and were the only instances of extragenital infection in a series of 47 patients with confirmed donovanosis diagnosed at a public health laboratory in Perth, Western Australia, between 1979 and the beginning of 1985. The third case, which occurred in 1977, was found in the records of a major teaching hospital.

Abdominal Muscles↗
PubMed1985

Efficacy of low doses of fenbendazole and its administration via drinking water in the prophylaxis of nematodiasis in grazing calves.

Under experimental conditions, fenbendazole given at doses of 0.4 and 1.0 mg/kg body weight suppressed calves' faecal output of Ostertagia and Cooperia species eggs and Dictyocaulus viviparus larvae. Both dose levels were given in the form of small daily drenches and the higher level showed greater efficacy. In a grazing experiment, medication with fenbendazole at 1.0 mg/kg/day administered intermittently to calves using an automatic dose dispenser almost completely suppressed the output of trichostrongylid eggs. As a result, infection on the pasture and in the calves remained at a low level throughout the grazing season. By contrast, control pasture and control calves showed rather heavy infection from mid-August onwards with significantly lower weight gains and widespread signs of parasitic gastroenteritis. At post mortem examination of representative calves from each group in November, the medicated animals had 99 per cent less Ostertagia species, whether adults or larvae arrested at the early fourth stage, and 95 per cent less Cooperia species compared with controls. Medication in the drinking water suppressed the faecal output of D viviparus larvae for most of the grazing season by comparison with the controls but the medicated calves became infected with this parasite towards the end of the season. Until this problem is overcome, precautions against parasitic bronchitis are advised when this system of medication is adopted.

Administration, Oral↗
PubMed1985

Human C5a modulates monocyte Fc and C3 receptor expression.

FcIgG and C3 (CR1 and CR3) receptors are responsible for binding opsonized particles, phagocytosis, and immune adherence reactions by circulating and tissue-fixed mononuclear phagocytes. Alterations in the expression of these receptors may thus significantly influence the function of these cells. Because chemoattractants have been shown to both recruit and modulate the function of monocytes, this study specifically examines the effects of human C5a and N-formyl-methionyl-leucyl-phenyl-alanine (FMLP) on human peripheral blood monocyte FcIgG and C3 receptor expression in vitro. Adherent, elutriator-purified monocytes were incubated with C5a (10(-7) to 10(-10) M) or FMLP (10(-5) to 10(-10) M) for 30 min at 37 degrees C, and FcIgG receptor expression was assessed by rosetting with sheep erythrocytes sensitized with limiting dilutions of IgG. Human C5a caused dose-related increases in Fc rosettes of 28% at 10(-9) M, 63% at 10(-8) M, and 167% at 10(-7) M (p less than 0.01). In contrast, no significant increases in monocyte Fc receptor expression were induced by FMLP. Similar rosetting experiments were performed with sheep erythrocytes opsonized with limiting amounts of human C3b to assess C3b receptor expression on adherent human monocytes stimulated with C5a (10(-7) to 10(-10) M) or FMLP (10(-6) to 10(-9) M) for 30 min at 37 degrees C. Again, human C5a caused dose-related increases in monocyte C3b rosette formation; at 10(-8) M and 10(-7) M concentrations of C5a, these increases equaled 119% and 196%, respectively (p less than 0.05). In these experiments, 10(-6) M FMLP also caused a significant increase of 110% in monocyte C3b rosette formation (p less than 0.05). Modulation of monocyte cell surface receptors by human C5a or FMLP was also examined by measuring cell fluorescence and side scatter by dual channel flow cytometry after staining normal leukocytes in citrated venous blood with receptor-specific monoclonal antibodies. These flow cytometric studies demonstrated that both C5a and FMLP induce dose-related increases in CR1 (C3b receptor) and CR3 (iC3b receptor) expression in both monocytes and neutrophils.(ABSTRACT TRUNCATED AT 400 WORDS)

Complement C5↗
PubMedDate not supplied

Effects of prenatal cocaine exposure on behavior during the early postnatal period.

Offspring of Sprague-Dawley dams injected SC with 40 mg/kg/3 cc cocaine HCl daily from gestational days 8-20, pair-fed dams injected with the vehicle alone and nontreated control dams were examined behaviorally during the early postnatal period. No significant differences were observed among the treatment conditions in maternal weight gain during pregnancy, duration of pregnancy, or number of live male and female pups/litter. Offspring body weights at birth and weaning, physical maturation and reflex development were not significantly affected by prenatal cocaine exposure. In contrast, neonates exposed prenatally to cocaine were observed to exhibit significant deficits in learning of an odor/milk association that nontreated offspring learned and retained for a 24 hr period. On postnatal day 12, cocaine offspring exhibited an increase in locomotor activity and attenuated wall climbing precipitated by footshock, in the absence of any alteration in sensitivity to footshock. Given that wall climbing has been previously shown to be strongly related to levels of catecholamine activity at this age, these data suggest the possibility that there may be some attenuation in catecholaminergic function in pups exposed gestationally to cocaine. The results of this study provide evidence that prenatal cocaine exposure may have an impact upon behavioral and cognitive function even during the early postnatal period. More work is needed to fully characterize the range of alterations observed and the neural mechanisms underlying these early exposure effects.

Animals↗