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Biomedical subjects

S R Adams

Publications and source records attributed to S R Adams.

43 records · Page 3Linked to original sources
PubMed1977

Evidence of onchocerciasis in Georgia cattle: prevalence at slaughter.

In the study for an animal model of onchocerciasis, particularly one dependent on a Simulium vector, the prevalence of Onchocerca lienalis in Georgia cattle was assessed. In 7 collections of cervical and umbilical skin samples and nuchal ligaments made between April and December, 1975, adult parasites were found in fascia of the ligamentum nuchae of 62 of 124 animals (50.0%), and microfilariae were present in 1 or more of the skin samples from 85 to 124 cattle (68.6%). Infections occurred in cattle of all ages examined (from 2 to more than 10 years). Microfilariae were found more frequently and abundantly in umbilical than in cervical skin. They were present in 47 of 62 cattle in which adult nematodes occurred, but also present in 38 of 62 cattle in which no adult nematodes were discovered. The adult nematodes caused considerable inflammation in the fascial sheath of the ligamentum muchae.

Animals↗
PubMed1977

Evidence of onchocerciasis in Georgia cattle: longitudinal survey of a small herd.

Between November, 1974, and March, 1976, skin biopsies were taken at 12 different times from a small herd of 8 to 10 cattle near Lawrenceville, Ga. Samples were incubated for 4 to 6 hours in Hanks' balanced salt solution and centrifuged, and the sediment was examined microscopically for microfilariae. Microfilariae were consistently found in 4 of 10 animals over a 12-month period; numbers of microfilariae ranged from 1 to 211, with a mean of 3.42, 12.89, 17.31, and 27.53 per 4-mm-diameter biopsy from the 4 individual animals. The parasite was evidently being transmitted on the farm, as evidenced by the presence of microfilariae in an animal born on the farm.

Animals↗
PubMedDate not supplied

Cytosolic Ca2+ oscillations in REF52 fibroblasts: Ca(2+)-stimulated IP3 production or voltage-dependent Ca2+ channels as key positive feedback elements.

Oscillations in cytosolic free calcium concentrations ([Ca2+]i) can be elicited in REF52 fibroblasts by three different modes of stimulation. We have previously demonstrated that [Ca2+]i oscillations result when these cells are simultaneously depolarized and stimulated with a hormone linked to phosphoinositide breakdown. Further evidence is now presented that such oscillations are linked to fluctuations in the concentration of IP3 and the Ca2+ content of an IP3-sensitive Ca2+ store. [Ca2+]i oscillations can also be generated in REF52 cells either by direct stimulation of G-proteins with GTP gamma S or AlF4- or by destabilizing the membrane potential and opening voltage-dependent calcium channels. This report compares the different types of oscillations and their mechanisms.

Aniline Compounds↗
PubMedDate not supplied

Laboratory-based measurements of swimming performance and related metabolic rates of field-sampled smallmouth buffalo (Ictiobus bubalus): a study of seasonal changes.

Numerous studies have demonstrated how the performance physiology of fish may change when they are acclimated to designated laboratory temperatures, but few researchers have examined naturally occurring seasonal effects on several physiological parameters associated with swimming performance. Using field-acclimatized smallmouth buffalo (Ictiobus bubalus) collected each season, we report significant seasonal effects in the following variables: critical swimming speed (modified), metabolic rate (standard, active, and scope for activity), and swimming efficiency (total and net cost of transport). Underlying seasonal changes in performance was the reproductive cycle of buffalo, particularly the period of fall gonadal recrudescence. Compared with spring, fall buffalo had a significantly lower mean critical swimming speed (72%) and lower active metabolic rate (53%), even when tested at similar temperatures. During spring, buffalo had a high mean critical swimming speed and low net cost of transport in comparison with other seasons. Buffalo are known to participate in a spring migration and spawning that may require the increased performance and efficiency observed during that season. In addition, significant sex effects were detected in winter measurements of standard metabolic rate and net cost of transport, with females the more efficient swimmers.

Animals↗