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Biomedical subjects

J T Bray

Publications and source records attributed to J T Bray.

8 recordsLinked to original sources

Shell disease and metal content of blue crabs, Callinectes sapidus, from the Albemarle-Pamlico Estuarine System, North Carolina.

Concentrations of 13 elements were determined for three tissues (gill, hepatopancreas, muscle) in diseased crabs from a contaminated estuary (Pamlico River, NC), and in non-diseased crabs from both the contaminated estuary and a relatively uncontaminated area (Albemarle Sound, NC) during the fall 1989 and summer 1990. The diseased crabs had lesions which completely penetrated their dorsal integument, while the non-diseased crabs lacked lesions. Sediments within the contaminated area showed enrichment of arsenic, cadmium, manganese, titanium and vanadium relative to the uncontaminated area. Levels of aluminum, arsenic, cobalt, manganese, nickel, titanium, vanadium and zinc were significantly higher in both gill and hepatopancreas in crabs from the contaminated area. Manganese was always highest in the diseased crabs in all tissues measured. The concentrations of the remaining elements were greater in the gills of diseased crabs, while highest values of these elements in the hepatopancreas varied among the diseased and non-diseased crabs from the polluted area. Conversely, copper levels were always highest in all tissues in crabs from the uncontaminated area, and typically lowest in the diseased crabs. Concentrations of aluminum and arsenic were also significantly greater in the muscle tissue of crabs from the contaminated area, but no distinct trend was evident with regard to diseased versus non-diseased crabs. Arsenic was the only element accumulated by crabs in the contaminated area which has a known toxic affect on the tissue responsible for cuticle synthesis and repair (hypodermis) in crustaceans. Metals also accumulated could possibly act synergetically to compromise normal metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Increase in renal magnesium overflow following aortotomy-induced hemorrhage in pigs.

Hemorrhage causes an increase in plasma Mg++ levels. This article identifies some of the tissues contributing to the hemorrhage induced increase in plasma Mg++. Anesthetized, splenectomized pigs were subjected to a 5 mm aortotomy. Blood samples from the abdominal aorta, inferior vena cava, pulmonary artery, hepatic portal vein, and renal vein were sampled for Mg++ changes caused by this uncontrolled hemorrhage. Aortotomy produced a rapid drop in arterial pressure and cardiac output, both of which remained depressed for the following 120 minutes (P less than 0.05). By 120 minutes, 6 of the 8 pigs survived, but three of the six survivors showed signs of cardiovascular decompensation. A significant increase in arterial plasma Mg++ was indicated by a paired t-test (P less than 0.05). Analysis of the venous samples also revealed a significant increase during the post-aortotomy period. Renal venous and hepatic portal venous plasmas both showed increases greater than that in the arterial plasma. The renal and splanchnic tissues, then, were partly responsible for the increase in the arterial Mg++ which follows hemorrhage.

Animals↗

Trace element status of some commercial smokeless tobaccos.

Baseline conditions for sample handling, processing, chemical extraction, and chemical analysis of chewing tobacco were established. The chemical solubility patterns for cadmium, copper, nickel, selenium, and zinc in several commercial brands of chewing tobacco were determined. Five extractants were used: water with pH value of 3.0, pH value of 5.4, and pH value of 6.5; amylase (0.1%); and methanol (99.9%). The bulk of the total cadmium, copper, nickel, and zinc in the tobacco samples was in a tightly bound form not extracted to any appreciable degree by the solvents used. Selenium was below detectable limits for each of the extractants. It has been reported that copper and zinc may counter the carcinogenic effects of cadmium and nickel. The extractants solubilized a greater amount of copper and zinc than cadmium and nickel from the total metal present in the chewing tobacco.

Adolescent↗

Development of a validation test for self-reported abstinence from smokeless tobacco products: preliminary results.

Using X-ray fluorescence spectrometry, 11 heavy elements at concentrations that are easily detectable have been identified in smokeless tobacco products. These concentrations were found to increase in cheek epithelium samples of the user after exposure to smokeless tobacco. This feasibility study suggests that the level of strontium in the cheek epithelium could be a valid measure of recent smokeless tobacco use. It also demonstrates that strontium levels become undetectable within several days of smokeless tobacco cessation. This absence of strontium could validate a self-report of abstinence from smokeless tobacco. Finally, the X-ray spectrum of heavy metal content of cheek epithelium from smokeless tobacco users could itself provide a visual stimulus to further motivate the user to terminate the use of smokeless tobacco products.

Cheek↗

Multielement analysis of metal-binding proteins in cytosol fractions.

The distribution of 24 elements among the cytosol protein fractions was determined for specimens of the bivalve mollusc Macoma balthica obtained from three estuarine locations subject to varying levels of metal pollution and on specimens of Rangia cuneata from three areas subject to varying degrees of thermal pollution. Of the 24 elements examined 15 occurred at levels above detection limits and in association with one or more of four distinct protein fractions. Levels of Ag and Cu associated with high molecular weight proteins and with "metallothionein-like" proteins permitted identification of those Macoma balthica specimens exposed to the greatest degree of metal stress.

Animals↗

Zinc as an integral component of the metabolic response to trauma.

Following injury, there is a major redistribution of zinc, as demonstrated by 65Zn tracer studies in rats receiving 20 per cent burns. This injury resulted in a rapid uptake of 65Zn into spleen, lung, wound, kidney and, particularly, liver, while the uptake of 65Zn was decreased in the brain, some muscle groups and, particularly, in bone. Simultaneously, plasma 65Zn occurred predominantly as the albumin bound fraction decreased. The total amount of tracer appearing in the wound was considerably less than that in the liver, where the induction of zinc binding protein was demonstrated in the cytosol. The synthesis of this protein may have an important regulatory role in zinc homeostasis following injury. These widespread changes in 65Zn distribution are consistent with the essential role of zinc in numerous metabolic processes and the increased metabolic activity of such tissues as the liver and the wound that follows injury. It is apparent that the liver has a central role in the early postinjury changes in zinc metabolism and that bone as well as muscle provides an available source of zinc in these circumstances.

Animals↗

Screening for selected trace elements in single cell populations by energy dispersive X-ray fluorescence spectrometry.

An adaptation of the thin film approach to energy dispersive X-ray fluorescence spectrometry (EDXRF) is described, which provides for a screening analysis for Fe, Ni, Cu, Zn, Se, and Cd in K-562 leukemic cells incubated in various metal-enhanced cultures. Valuable quantitative and semiquantitative data can be obtained on as few as 400,000 cells.

Cells, Cultured↗