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Biomedical subjects

G Moore

Publications and source records attributed to G Moore.

At least 163 records · Page 9Linked to original sources

Theory and practice in the development of a multisorbent passive dosimeter system.

A new family of passive dosimeters has been developed to allow the use of multiple sorbents and analytical techniques suited to a wide range of sampling situations. The dosimeter hardware has been designed to be reusable with interchangeable sorbent capsule refills to provide low cost per test. Capsules have been designed both for conventional solvent desorption and to be used with a newly developed rapid thermal desorber capable of automation for multiple samples. The development of the system is described together with laboratory tests and results and the effects of environmental parameters.

Air Pollutants, Occupational↗

Inhibition of cell division by interferons. The relationship between changes in utilization of thymidine for DNA synthesis and control of proliferation in Daudi cells.

Inhibition of the proliferation of Daudi cells by exposure to human lymphoblastoid interferons is associated with an early and marked decrease in the incorporation into DNA of exogenous [3H]thymidine when cells are incubated with trace amounts of this precursor. In contrast, incorporation of exogenous deoxyadenosine into DNA is unchanged under the same conditions. Interferon treatment results in a lowering of thymidine kinase activity, an effect which may be largely responsible for the inhibition of incorporation of labelled thymidine into DNA. At higher concentrations of exogenous thymidine, which minimize the contribution of intracellular sources to the dTTP pool, the inhibition of thymidine incorporation is abolished. Under conditions in which exogenous thymidine is rigorously excluded from the medium or, conversely, in which cells are entirely dependent on exogenous thymidine for growth, the magnitude of the inhibition of cell proliferation by interferons is the same as under normal culture conditions. We conclude that, even though cell growth is impaired, the rate of DNA synthesis is not grossly inhibited up to 48 h after commencement of interferon treatment. Furthermore, changes in neither the utilization of exogenous thymidine nor the synthesis of nucleotides de novo are responsible for the effect on cell proliferation.

Cell Division↗

Hematologic effects of hemoglobin solutions in animals.

Hb could cause abnormalities in coagulation if stromal lipid contaminated the solution. We prepared Hb by two procedures; it was lipid-free by the assays employed. These solutions were given to three species of animals (dogs, pigs, primates) at the dose of 15 ml/kg and then observations were made for hematologic changes. Only dogs demonstrated significant alterations. A consistent transient thrombocytopenia (60% drop) was seen five minutes after infusion and returned to baseline by one hour. Control dogs, receiving albumin, also showed a transient thrombocytopenia but not as pronounced (15% drop). Two Hb-treated dogs had signs of subclinical DIC (positive FDF, protamine sulfate precipitation, and a 70% drop in Factor VIII). There were no differences in any hematologic parameters between Hb and albumin treated pigs and monkeys. These results show that species-specific hematologic responses to lipid-poor Hb can be demonstrated.

Animals↗

Complete amino acid sequence of urotensin I, a hypotensive and corticotropin-releasing neuropeptide from Catostomus.

Urotensin I, purified from extracts of the urophysis of a teleost fish (Catostomus commersoni), exhibits potent hypotensive activity (mammals and birds) and corticotropin-releasing activity (both fish and mammals). The primary structure of this 41-residue peptide was determined to be H-Asn-Asp-Asp-Pro-Pro-Ile-Ser-Ile-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg-Asn-Met-Ile-Glu- Met-Ala-Arg-Ile-Glu-Asn-Glu-Arg-Glu-Gln-Ala-Gly-Leu-Asn-Arg-Lys-Tyr-Leu-Asp-Glu -Val-NH2. Extraction with 0.1N HCl at 100 degrees C cleaves the amino-terminal tripeptide, yeilding a fully active analog, urotensin I(4-41). The amino acid sequence was confirmed by measuring the biological activity of synthetic urotensin I(4-41). Urotensin I exhibits a striking sequence homology with ovine corticotropin-releasing factor and with frog sauvagine. These three peptides exhibit similar activities in biological test systems.

Amino Acid Sequence↗

Evaluation of coal liquefaction technologies by Salmonella mutagenesis.

Coal liquefaction materials made by two processes were found to be mutagenic in the Salmonella/microsome assay. Data from this type of in vitro assay can be used in the toxicological assessment of these processes. Such evaluations of the health and environmental impacts of technologies would aid in the development of alternate energy sources.

Animals↗

Serum concentrations of calcium and vitamin D metabolites in prosimians.

The concentrations of total calcium, 25-hydroxyvitamin D [25-(OH)D] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were measured in serum obtained from prosimians, the brown lemurs. The mean serum calcium level was 10.6 mg/dl in male and female lemurs. The mean serum mean 25-(OH)D concentration in serum from male and female lemurs was 27.1 and 31.0 ng/ml, respectively. The mean serum level of 1,25-(OH)2D3 in the female and male lemurs was 65.2 and 65.9 pg/ml, respectively. A small segment of the lemurs had hypercalcemia and elevated serum concentrations of 25-(OH)D or 1,25-(OH)2D3, suggesting the idea that the episodic ingestion of a large quantity of the calcium- and vitamin D-enriched diet normally provided ad libitum might cause hypercalcemia.

Animals↗

Mutagenicity of products from coal gasification and liquefaction in the Salmonella/microsome assay.

As a first step in the assessment of their possible bio-effects, coal-related materials were tested for mutagenicity in the Salmonella/microsome assay. Of three coal gasification by-products tested, only a tar was mutagenic for any of four Salmonella strains. The following liquefaction materials were mutagenic for strains TA1538, TA98, and/or TA100: A liquefaction vehicle oil and coal hydrogenation filtered liquid, separated bottoms, vacuum overhead, and vacuum bottoms. Neither powdered coal nor water produced as a by-product of the hydrogenation process was positive in the Salmonella test. No coal-related material was mutagenic for the missense mutant TA1535 or for any strain in the absence of metabolic activation provided by rat hepatic homogenates (S9). In all but one instance Aroclor 1254-induced S9 provided the maximum activation for mutagenesis. Fractionation of all samples was undertaken by serial extraction with organic solvents of increasing polarity (hexane, toluene, methylene chloride, acetonitrile). Highly mutagenic materials were found in fractions of the hydrogenation filtered liquid, vacuum overhead, and vacuum bottoms. Thus far non-mutagenic samples have not yielded mutagenic components upon fractionation.

Animals↗

Sulfite oxidase deficiency: a high risk factor in SO2, sulfite, and bisulfite toxicity?

It has been hypothesized that sulfite oxidase deficient persons may be at increased risk to toxicity from SO2 and dietary sulfites widely used for food preservation. Sulfite oxidase is believed to be responsible for the detoxification of SO2 and/or sulfite to sulfate for excretion. Human and animal studies have shown that S-sulfonates, believed to transport sulfite in the blood, are formed in response to exposure to low levels of SO2. Besides its numerous toxic effects, e.g. respiratory impairment, interference with immunological response and oxygen transport and platelet aggregation inhibition, SO2 has the ability to alter DNA during replication causing T . A transitions, chromosome abnormalities and depression of DNA synthesis.

Animals↗

The treatment of phobic anxiety by zimelidine.

Seven patients who were diagnosed as suffering from phobic anxiety were treated with a new antidepressant which causes relatively selective inhibition of serotonin uptake. This compounds, zimelidine, was given for five weeks in doses of up to 300 mg per day. One patient dropped out of the study. Of the remaining six patients all but one made an improvement, which in most cases is thought to have been a drug effect. One patient relapsed some months following treatment and responded again to treatment with zimelidine having failed to respond to other psychotropic drugs.

Anxiety↗