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Biomedical subjects

R J Hamilton

Publications and source records attributed to R J Hamilton.

52 records · Page 3Linked to original sources
PubMed1987

Effects of fluoride emissions from a modern primary aluminum smelter on a local population of white-tailed deer (Odocoileus virginianus).

The influence of fluoride emissions from a modern aluminum smelter on concentrations of skeletal fluoride and dental fluorosis in a resident population of white-tailed deer was studied. The smelter was located on Mount Holly Plantation in South Carolina, and concentrations of skeletal fluoride in the deer collected at Mount Holly increased approximately five-fold 3 yr after the operation began. Increases in skeletal fluoride of less than two-fold were observed in deer obtained from Medway Plantation which has its nearest boundary 1.6 km from the smelter site. No dental fluorosis was observed in deer collected at Medway Plantation, but mild dental fluorosis was observed in a significant number of deer collected at Mount Holly Plantation. The dental fluorosis that was observed was not associated with incisor wear or with fluoride-induced molar wear. Osteofluorosis of mandibles or metacarpals was not observed in any of the deer obtained from either plantation. The data obtained from this study indicated that the presence of a modern aluminum smelter caused a detectable increase in concentration of skeletal fluoride in the resident population of white-tailed deer, but that no adverse health effects were seen.

Air Pollutants↗
PubMed1985

Effects of fluoride ingestion on white-tailed deer (Odocoileus virginianus).

The effects of the addition of 25 or 50 ppm fluoride (F), as sodium fluoride (NaF), to the rations of 5-mo-old male white-tailed deer were similar to those observed in domestic cattle fed similar amounts of fluoride. The ingestion of 50 ppm F for 2 yr resulted in the accumulation of over 7,000 ppm F in bone ash. Accumulation of fluoride in antlers was extensive and occurred more rapidly than in skeletal tissue. Fluoride ingestion resulted in lesions on the developing incisors that were similar, but not identical to those seen in other species. Increased molar wear in the deer fed 50 ppm F was minimal, and no gross pathology of the mandible was observed. Only mild hyperostosis of the long bones was evident.

Animal Feed↗
PubMed1983

Value of cuticular and internal hydrocarbons for the identification of larvae of Anopheles gambiae Giles, Anopheles arabiensis Patton and Anopheles melas Theobald.

Gas chromatographic profiles of the cuticular and internal lipids extracted from 4th-instar larvae of the Anopheles gambiae complex have shown quantitative differences in their chain length distributions. For example, hydrocarbons extracted with 95% ethanol showed relative differences in peak heights eluting at Kovat indices (KI's) 2840 (An. gambiae 1.21, An. arabiensis 1.39 and An. melas 1.14) and 3150 (An. gambiae 6.73, An. arabiensis 13.40 and An. melas 13.50). However, while using the non-hydrocarbon fractions, differences were obtained at a KI of 2160 (An. gambiae 0.45, An. arabiensis 0.45 and An. melas 1.16) and at a KI of 2430 (An. gambiae 2.90, An. arabiensis 1.81 and An. melas 3.50). Utilizing the total ethanol extract and omitting the TLC (thin layer chromatography) step, thus saving four hours of analysis time, good separation was achieved at a KI of 2060 (An. gambiae 0.60, An. arabiensis and An. melas 0.0) and at a KI of 2430 (An. gambiae 1.13, An. arabiensis 0.69 and An. melas 1.59). Other differences were also noted in the profiles which could identify one or more of the three species. Good separation could be made on single larvae as well as on small batches of specimens. It was concluded that analysis of cuticular and internal lipids provides a useful biochemical method of distinguishing larvae of these species, but further studies are needed on these and other species of the An. gambiae complex collected from many localities in Africa.

Animals↗
PubMed1967

Leaf epicuticular waxes.

The external surface of the higher plants comprises a cuticular layer covered by a waxy deposit. This deposit is believed to play a major part in such phenomena as the water balance of plants and the behavior of agricultural sprays. The wax contains a wide range of organic compounds. These complex mixtures are amenable to modern microchromatographic and microspectrometric analytical procedures. The few surveys which have been made of the species distribution of certain classes of constituents indicate that such distribution may be of limited taxonomic value; however, the wax composition of a species may differ for different parts of the same plant and may vary with season, locale, and the age of the plant. This fascinating subject, in which the disciplines of botany, biochemistry, chemistry, and physics overlap and interact, is still in a very active state. Much remains to be learned about the composition and fine structure of the wax deposits, and, for this, experimental study of wax crystallization and permeation through artificial membranes will be required. Enzymic studies, radiolabeling, and electron microscopy will be needed to reveal the mode of biogenesis of the wax constituents and their site of formation and subsequent pathway through the cuticle to the leaf surface.

Aldehydes↗
PubMedDate not supplied

Facility report. Department of Medical Imaging and Radiological Sciences at Vanderbilt University.

This department is presented as an academic prototype to meet the health care and research challenges of the next decade. Composed of four separate divisions (diagnostic radiology, radiation oncology, nuclear medicine, radiologic sciences) with appropriate sections, it is organized according to the concept of an integrated basic science-service facility.

Hospital Bed Capacity, 500 and over↗