Clifton Blincoe

Dietary chromium — forms and availabilities

The chromium naturally occurring in plants eluted from Sephadex G-25 at approximately 2600 D. Total chromium was quantitated with flameless atomic absorption spectrophotometry. A plant ligand tagged with radioactive chromium both in vivo and in vitro migrated on Sephadex G-25 identically to the naturally occurring chromium compound. The molecular weight of the radioactively tagged chromium compound was 2600 daltons on Sephadex G-25. Similar complexes isolated from plant species were found attached to an organic ligand. The ligand appears to have 2 components, differing in composition by an amine group. This extremely stable (KD = 9 X 10(-5)anionic complex does not contain peptide or deoxyribose units. When alfalfa was exposed to either Cr(III) or Cr(VI), only Cr(III) was isolated in this organic chromium compound. The alfalfa bioreduction system can be saturated, as evidenced by Cr(VI) isolation of ionic in those plant extracts incubated with high levels of Cr(VI) in vitro. The gastrointestinal chromium physiology studies show that the radioactively labelled plant chromium compounds remained intact through the gastrointestinal tract up to the large intestine. Some degradation products were identified in the rat cecum. Approximately 30% of the plant chromium available to the rat was absorbed across the gastrointestinal tract.

The simultaneous separation and washing of erythrocytes

Abstract Erythrocytes may be prepared by centrifugation of a layer of diluted whole blood through isoosmotic sucrose of slightly less specific gravity than erythrocytes. Erythrocytes so prepared were compared with those prepared by repeated washing with isoosmotic saline. No statistically significant differences were found in acetylcholinesterase, fluoride or creatinine concentrations in erythrocytes prepared in this manner. The active transport mechanisms excluding sodium and transporting selenate were unchanged by the procedure. A considerable savings in time is achieved using the proposed procedure for the routine preparation of erythrocytes.

Sample oxidation procedures for the determination of chromium and nickel in biological material

Abstract Sample preparation methods for atomic absorption spectrophotometric analysis of chromium and nickel in biological materials were examined. Radiotracer recovery, precision of analysis and analysis of NBS reference samples were the criteria used. Chromium and nickel in biological materials can be successfully prepared for atomic absorption spectrophotometry by dry ashing with nitric acid treatment of the partially oxidized sample. It was necessary to use at least 5% nitric acid to extract the chromium and nickel from the ash. Vet digestion with nitric acid alone was satisfactory for nickel but not for chromium. Wet digestion gave greater variance and required considerably more time. We found no evidence of loss of chromium by either volatilization or insolubility. Since this method is satisfactory for nickel determination it may be implied that it is also satisfactory for other nonvolatile first transition series elements.

Simulation of copper metabolism by mammals

Copper is both an essential and a toxic element for man and other animals. A deterministic compartment transfer model was developed that can be executed on a personal computer. This model appears to be equally applicable to rats and cows which exhibit grossly different copper metabolism patterns. This model incorporates compartment limits analogous to those found in normal animals. Simulations gave good agreement with published data. This model should be useful for planning experimental investigations into the differences in copper metabolism between species.

In vitro formation of chromium complex from higher plants

Abstract Chromium as either chromate or chromic ion reacts with expressed alfalfa liquid to form two complexes. The larger complex may be assembled from the smaller complex and the formation of the larger complex requires a heat labile factor.

Bovine Thyroid Iodine-131 Concentrations Subsequent to Soviet Nuclear Weapon Tests

The iodine-131 concentration in thyroids of cattle slaughtered in Reno, Nevada, was measured during and following recent atmospheric nuclear weapon tests by the U.S.S.R. The iodine-131 concentration rose rapidly to a maximum and then declined with an apparent half-life of 7 days after conclusion of the test series. The average dose to bovine thyroids from this test series was estimated to be 17 rads.

Chemical state of magnesium in plasma

Abstract All the magnesium in ovine and bovine plasma behaves as a low molecular weight cationic complex. No plasma magnesium is associated with protein.

Biochemical form of nickel in alfalfa

Abstract The essential trace element, nickel, is readily taken up by plants Alfalfa (Medicago sativia, L.) synthesizes a molecule that binds nickel. The majority of the complex is water soluble. The Nickel complex(es) are not ionic nickel but exist as a larger moiety with a cationic or anionic charge. The polydispersed complex is about 2000 daltons in size. When the nickel complex is mechanically extracted from the alfalfa, the radiolabeled complex is released slowly, indicating that the bound nickel complex is in equilibrium with a free complex in solution. This complex will form in vitro when expressed fluid from alfalfa is combined with nickel-63

Cesium-137 from environmental sources in desert range cattle from 1962 through 1968

Abstract Following the cessation of atmospheric nuclear weapons testing in late 1962, cesium-137 concentrations in desert range cattle continued to increase for a year and then decreased following the trend in world-wide fallout. On the Nevada Test Site of the U. S. Atomic Energy Commission, range cattle soft-tissue concentrations of 147Cs reached a maximum earlier, indicating response to local contamination. Tissue 137Cs concentrations did not respond to small, isolated releases of fission products from underground testing. The levels of 137Cs observed were comparable with those found in meat elsewhere in the northern hemisphere.

Computer simulation of copper pharmaceuticals in cattle

Abstract Treatment and prevention of copper deficiency in cattle by injection of copper pharmaceuticals is often the preferred palliative. Controlled release pharmaceuticals have often been used. These treatments were simulated using a personal computer. Simulation of copper glycinate and copper edetate injections agrees well with published studies. The copper status and copper intake of cattle are important in the metabolism of injected copper. Deficient animals metabolize injected copper more rapidly than copper sufficient animals. Simulations indicate that normal copper metabolism probably requires the induction of copper reactive proteins in the liver. With rapidly absorbed pharmaceuticals, the blood copper concentration rises dramatically especially in copper deficient animals. This may be involved in the pathologies and deaths reported reported using these preparations. Liver copper is the only available copper storage. Apparent liver turnover of copper is independent of the speed with which a dose is absorbed except for extremely slowly absorbed materials. Sustained release pharmaceuticals prolong the duration of effective liver concentrations of copper.