Biomedical subjects

D M Moran

Publications and source records attributed to D M Moran.

44 records · Page 3Linked to original sources

PubMed1978

Investigation of the reputed inhibition of the Prausnitz-Küstner reaction by the pentapeptide Asp-Ser-Asp-Pro-Arg.

An investigation has been made of the inhibitory activity of the so-called Hamburger pentapeptide, Asp-Ser-Asp-Pro-Arg, in both the human Prausnitz-Küstner and baboon passive cutaneous anaphylaxis systems. With a dose of 6 microgram peptide, administered intradermally 24 h prior to diluted allergic serum from a horse-dandruff-sensitive individual, partial inhibition of wealing was observed in three different normal recipients following the pricking in of specific allergen. In one of the recipients, inhibition of flaring was observed at test sites subsequently challenged with timothy grass pollen allergen. A similar dose of pentapeptide, again injected intradermally 24 h prior to passive sensitisation, was shown to inhibit extravasation in a normal baboon on subsequent challenge with horse dandruff (but not grass pollen) allergen by subcutaneous injection into the upper arm. In vivo tests performed in the forearms of grass-pollen-sensitive individuals failed to provide convincing evidence of displacement of mast-cell-bound IgE antibody by the pentapeptide.

Animals↗

PubMed1977

Effects of streptovaricins and their degradation products on RNA-directed DNA polymerase of Rauscher leukemia virus.

The activities of streptovaricin complexes, streptovaricins, streptovals, and streptovarinic degradation products were elevated against RNA-directed DNA polymerases of Rauscher leukemia virus, DNA-dependent DNA polymerase of bacterial and mammalian cells, and DNA-dependent RNA polymerases of mammalian origin. The activities of streptovaricins were also listed for comparison purposes. The effects of streptovaricin complexes on viral DNA polymerases varied significantly from lot to lot, and streptovaricin complex lot 7 was the most active. All the streptovals and streptovaricin degradation products except varicinal A showed a marked improvement (twofold to tenfold) in activity against the viral enzyme over the parent streptovaricins. None of these compounds, however, displayed any significant effect on either the DNA polymerase of L1210 leukemia cells and Escherichia coli or the RNA polymerase of isolated nuclei of mouse liver. As a result of tests in these systems, some specific inhibitors of RNA-directed DNA polymerases of Rauscher leukemia virus were selected.

Chemical Phenomena↗

PubMed1977

Chemical modification of crude timothy grass pollen extract. III. The effect of glutaraldehyde-induced aggregation on antigenic and immunogenic properties.

Timothy pollen extracts have been reacted with glutaraldehyde under conditions leading to different degrees of aggregation of the product. Aggregation tends to enhance the previously demonstrated effects of glutaraldehyde in that reactivity with human IgE antibody, and ability to induce IgE antibody in the Bordetella pertussis-treated rat, are further reduced. Ability to induce IgG antibody with specificity for unmodified extract is substantially retained in all aggregated products.

Aldehydes↗

PubMed1976

Chemical modification of crude timothy grass pollen extract. I. Antigenicity and immunogenicity changes following amino group modification.

Glutaraldehyde modification was found to reduce the allergenic potency of crude timothy pollen extracts yet even highly substituted materials retained the capability of inducing the formation of allergen-specific antibody in animals. Experiments showed that these antibodies were capable of blocking skin test reactions to native timothy allergens in pollen-sensitive human volunteers. The value of glutaraldehyde-modified allergen extracts for use in desensitization vaccine therapy is discussed.

Aldehydes↗

PubMed1976

Chemical modification of crude timothy grass pollen extract. II. Class and specificity of antibodies induced by chemically modified timothy grass pollen extract.

The effects have been studied of three different chemical modifications of timothy grass pollen extract on various immunological properties. The ability to induce IgG antibody with specificity for native antigen was least affected by glutaraldehyde treatment; IgE antibody production was reduced to a similar extent by all three modifications; there was no increase in IgM production; delayed reactions were reduced. New antigenic determinants were introduced by all the modifications, but the effect was minimal following glutaraldehyde treatment. The significance of these results and the potential application of modified allergen in hyposensitisation therapy are discussed.

Acetoacetates↗

PubMed1975

Inhibitor of Clostridium perfringens formed by heating sodium nitrite in a chemically defined medium.

An inhibitor of Clostridium perfringens formed when low levels of nitrite were autoclaved with a defined chemical medium. A systematic study of the medium revealed that only amino acids and mineral salts were involved in the production of this inhibitor, which was proven to be a toxic compound formed from cysteine, ferrous sulfate, and sodium nitrite. The inhibitor was compared to several known compounds. S-nitrosocysteine inhibited the test organism, but would not form in the test system in amounts large enough to explain the observed inhibition. Roussin red salt was unstable in the test system and therefore was not the inhibitor. Roussin black salt, which was also inhibitory, could form in sufficient amounts to explain the inhibition. A complex of cysteine, iron, and nitric oxide was detected in the autoclaved solution of cysteine, ferrous sulfate, and sodium nitrite; this cysteine complex did not appear to be inhibitory, however, at levels which could form in the autoclaved medium. The observed inhibition may have been due to the combined effects of sublethal concentrations of each compound.

Anti-Bacterial Agents↗

PubMedDate not supplied

Quantitative analysis of emetine and cephaeline by reversed-phase high performance liquid chromatography with fluorescence detection.

A versatile method for the quantitation of emetine and cephaeline in biological samples is described. Two milliliters of samples containing N-propylprocainamide as the internal standard are buffered to pH 9 and extracted with n-butyl chloride. After subsequent back extraction into 0.01 M hydrochloric acid, a portion of the acid layer is analyzed by reversed-phase high performance liquid chromatography with fluorescence detection. Routinely, the minimum level of detection for both drugs is 5 ng/mL and linearity is demonstrated from 5 to 2500 ng/mL.

Body Fluids↗

PubMedDate not supplied

Zinc deficiency dermatitis accompanying parenteral nutrition supplemented with trace elements.

Zinc deficiency dermatitis in a patient on long-term total parenteral nutrition (TPN) with trace-element supplementation is reported, and the therapeutic aspects of zinc deficiency are reviewed. A 36-year-old white man was hospitalized and found to have a small-bowel perforation secondary to internal herniation. Small-bowel resection with end-to-end anastomosis was performed, and TPN supplemented with folic acid, multivitamins, trace elements (including elemental zinc 2 mg/day), and fat was begun. Four months later, the patient developed a moist, erythematous, painful groin rash that did not respond to one month of topical antifungal and topical and intravenous antibacterial treatment. At five months after admission, zinc deficiency was suspected; serum zinc concentration was 85 micrograms/dl (normal = 55-150 micrograms/dl). The total daily zinc dose was increased to 60 mg, and within two days the patient's lesions began to improve. The rash healed within two weeks. Six days after increased zinc therapy was begun, lab tests showed: hair zinc content, 185 micrograms/g (normal = 163 micrograms/g); serum zinc content, 90 micrograms/dl; and erythrocyte zinc content, 1058 micrograms/dl (normal = 1100-1400 micrograms/dl). Signs and symptoms of zinc deficiency, zinc disposition in man, predisposing factors to zinc deficiency, laboratory analysis of zinc nutriture, zinc therapy, and zinc toxicity are discussed. Knowledge of drug use, diet, geographic location, underlying disease, and other patient-specific factors is important in recognizing the patient at risk of developing zinc deficiency. Several tests should be performed to document zinc deficiency. Zinc replacement guidelines are outlined.

Adult↗