PubMed Health⌕ Search

Biomedical subjects

R J Shamberger

Publications and source records attributed to R J Shamberger.

At least 19 recordsLinked to original sources
PubMed1987

Lactate dehydrogenase isoenzyme 1 as determined by inhibition with 1,6-hexanediol and by two other methods in patients with myocardial infarction or cardiac-bypass surgery.

In this assay for lactate dehydrogenase (EC 1.1.1.27) isoenzyme 1 (LD-1), 1,6-hexanediol is added to serum after total LD has been measured. After incubation for 5 min the total LD remaining is determined. Samples from patients who had a myocardial infarction or who had undergone bypass surgery were assayed simultaneously by the 1,6-hexanediol method, the Roche "Isomune LD," and by electrophoresis on agarose gel. For 101 analyses of sera from bypass patients, correlations were high for results by the inhibitor method and electrophoresis (r = 0.96), by Roche Isomune and the inhibitor method (r = 0.96), and by the Roche method and electrophoresis (r = 0.97). In general, values for total LD were quite comparable by the three methods, but results by the inhibitor method seemed slightly higher and showed greater variability (CV) than those by the electrophoretic method. The assay is simple--requiring one reagent addition and a short incubation--and inexpensive: LD-1 can currently be determined for less than 1 over the cost of determining total LD.

Coronary Artery Bypass↗
PubMed1986

Selenium metabolism and function.

Selenium like many other elements has a bimodal effect. At lower concentrations selenium is an essential trace element necessary for the growth of man and animals. However, at higher concentrations, selenium has toxic properties for man and animals. The biochemistry of selenium as a component of glutathione peroxidase and the analytical properties of selenium are also outlined.

Animals↗
PubMed1985

The genotoxicity of selenium.

Selenium at nutritional levels has been shown to have numerous anticarcinogenic or preventative effects against carcinogen-induced breast, colon, liver and skin cancer in animals. Many of these anticarcinogenic effects have been summarized. In addition, numerous mutagenic and antimutagenic effects of selenium compounds have been reported. Some of the selenium compounds frequently tested for mutagenicity are listed in Table 1. Because of the numerous reported anticarcinogenic and preventative effects of selenium, many individuals are supplementing their diets with amounts of selenium that are greater than the recommended daily requirement. Selenium is also used widely in industrial products such as selenium rectifiers, photoelectric batteries, alloys and paints. Because selenium at higher levels is known to be toxic, there should be a greater understanding about its genotoxic as well as its beneficial effect. The object of this review is to summarize experimental evidence both for the antimutagenic and the mutagenic effect of selenium.

Alkylation↗
PubMed1984

Serum sialic acid in normals and in cancer patients.

A simple procedure is described for the detection of sialic acid in serum. After a direct addition of Ehrlich reagent to serum and an incubation at 56 degrees C for eight hours, the resulting mixture is diluted with saline. After centrifugation, the color in the supernatant is determined at 525 nm in a spectrophotometer. Serum sialic acid was significantly greater in cancer patients than in normals. Cancer patients with metastases had significantly greater sialic acid than cancer patients without metastases. In two cancer patients, sialic acid levels returned to normal after surgery. The diagnostic usefulness of 95.6% was similar to that reported with lipid-soluble sialic acid and seemed to be superior to CEA and other tumor antigens associated with a limited spectrum of tumors. However, patients with inflammatory diseases such as arthritis, Crohn's disease and psoriasis also showed elevated sialic acid levels. Ultrafiltration showed that almost all of the sialic acid was retained on an Amicon filter, which suggests that sialic acid was bound to a macromolecule. A quality control serum run 25 times had a coefficient of variation (CV) of 8.4% and the same serum ran on 42 days had a CV of 11.6%.

Benzaldehydes↗
PubMed1983

Effects of blood and urine on lead analyzed by flameless atomic absorption.

About a 10-15% difference was observed by comparing (CDC) bovine blood to a lead standard addition curve using human blood. Results similar to the mean of the CDC survey were obtained by adding lead directly to the bovine blood using standard addition techniques. These results indicate that standard additions of lead should be made to the same matrix and that matrix effects can occur when blood from different species is compared. Analyses of both CDC bovine blood and human blood with added Triton X-100 showed greater sensitivity and reproducibility than similar blood without added Triton X-100. (NH4)2HPO4 greatly enhanced the signal height of lead in urine while nitric acid had a much less effect. The enhancement by (NH4)2HPO4 of the lead signal was at final concentrations greater than 10 g/l. At less than 10 g/l enhancement rapidly decreased. Triton X-100 did not enhance the signal height of lead in urine. Calcium ion and chloride ion did not decrease the lead absorption peak in urine, but magnesium ion did decrease the height of the absorption peak in urine.

Calcium↗
PubMed1979

Antioxidants reduce the mutagenic effect of malonaldehyde and beta-propiolactone. Part IX. Antioxidants and cancer.

Increasing concentrations of malonaldehyde and beta-propiolactone were increasingly mutagenic with 7 mutants of Salmonella typhimurium, 5 of which mutated bya frameshift mechanism and 2 of which mutated through base-pair substitution. The antioxidants vitamin C, vitamin E, selenium and butylated hydroxytoluene (BHT) at 3 logarithmic concentrations markedly reduced mutagenesis in those strains which mutated by frameshift mechanism.

Ascorbic Acid↗
PubMed1979

Effect of protein depletion and repletion on liver structures, nitrogen content and serum proteins.

The data presented in this paper demonstrate that a liver which has been severely damaged by protein malnutrition can be restored to normal composition, anatomy and functional capability by central venous feeding. An atypical serum protein electrophoretic pattern characterizes protein malnutrition. TPN repletion restores all of the protein fractions back to normal except for the gamma globulin levels. Liver nitrogen is a very sensitive index of both protein malnutrition and TPN repletion. The liver is dramatically effected by protein malnutrition and its return toward normal can be achieved by TPN support as demonstrated in this paper.

Animals↗
PubMed1978

Methods compared for determining zinc in serum by flame atomic absorption spectroscopy.

We compared two methods for determination of serum zinc by flame atomic absorption spectroscopy. The first involved 10-fold dilution of serum with water; the second, deproteinization of serum with trichloroacetic acid. Analytical recovery of Zn2+ added to serum averaged 99.3 and 99.9%, respectively, by the two methods, but measured concentrations were consistently greater by the second method [mean difference, 118 +/- 27 (SD) mug/liter]. For the analysis of 55 sera, measured concentrations were also greater by the second method [mean difference, 91 +/- 28 (SD) mug/liter]. We dialyzed serum to remove most of the zinc and measured analytical recovery of increasing amounts of Zn2+ added to this dialyzed serum or, conversely, of zinc in a mixture of increasing volumes of dialyzed serum in a Zn2+ standard. Recovery results for the dilution method showed an interference by an unidentified, but nondialyzable serum component(s). Recovery was not improved by use of (a) a "high-solids" burner, (b) a diluent containing 1-butanol, or (c) a Mn2+ internal standard.

Humans↗
PubMed1977

Malonaldehyde content of food.

Several types of commercially available food both cooked and uncooked were tested for the presence of the carcinogenic initiator and mutagen, malonaldehyde, which is a breakdown product of unsaturated fatty acids. The thiobarbituric acid derivative of malonaldehyde from meat extract was identified either by thin layer chromatography or by gas chromatography after silylation. Malonaldehyde was also identified directly by gas chromatography. Among the meats purchased from supermarkets, beef had the greatest amounts of malonaldehyde. Turkey and cooked chicken had high levels. Most cheeses had only small amounts of malonaldehyde. In contrast, many vegetables and fruits had either minute amounts or no malonaldehyde.

Animals↗
PubMed1973

Carcinogen-induced chromosomal breakage decreased by antioxidants.

Blood leukocyte cultures were incubated with antioxidants and the carcinogens sodium cyclamate and 7,12-dimethylbenz(alpha)anthracene in different combinations. There were 17.4% more chromosomal breaks in the group of cells treated with dimethylbenzanthracene only than in the untreated controls. The reductions in chromosomal breaks by the antioxidants were as follows: ascorbic acid, 31.7%; butylated hydroxytoluene, 63.8%; Na(2)SeO(3), 42.0%; and dl-alpha-tocopherol, 63.2%. Multiple chromosomal breaks were distributed equally throughout the experimental groups. Sodium cyclamate had only slightly more chromosomal breaks than the controls (11.6 compared to 10.9%). In the cyclamate groups treated with Na(2)SeO(3), 11.2% of chromosomes were broken. More acrocentric-type chromosomal breaks (21.7%) were seen in the untreated cells than the cells treated with cyclamate (3.4%) or dimethylbenzanthracene alone (4.8%). The carcinogen-treated groups had a higher percentage of meta breaks than the untreated controls.

Adult↗