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W T BERALDO

Publications and source records attributed to W T BERALDO.

15 recordsLinked to original sources
PubMed1962

Inhibitory effects of carbohydrates on histamine release and mast cell disruption by dextran.

Alloxan diabetic rats failed to show the skin reaction (blue spot) evoked by dextran, whereas the effects produced by histamine and compound 48/80 were not altered. When dextran and glucose were injected simultaneously into the skin the reaction was inhibited. In vitro, mast cell alterations produced by dextran occurred simultaneously with histamine release; both processes were inhibited by glucose, other carbohydrates related to glucose, and inhibitors of anaphylaxis. These experiments suggest that dextran releases histamine by a mechanism similar to that found with 48/80 and anaphylaxis in the rat. The inhibitory effect of carbohydrates may be understood on the basis of a competitive mechanism.

Alloxan↗
PubMed1961

Antigenic properties of purified fractions from Ascaris lumbricoides var. Suum on naturally sensitized guinea-pig.

Purified extract of Ascaris injected intravenously into guinea-pigs produced a reaction very similar to the anaphylactic reaction. As shown by the ratio of deaths to survivals the toxic fraction contained in Ascaris extract was purified 3 to 4 times. After intravenous injection animals presented both anaphylaxis-like shock and mast cell damage similar to that observed in anaphylaxis. Perfusion of the lungs with Ascaris fractions released histamine. Isolated guinea-pig ileum when in contact with Ascaris fractions showed a response followed by desensitization. Heating the ileum to 45 degrees C or previous desensitization to anaphylatoxin excluded the participation of the latter in this contraction. In vitro, sensitization from one guinea-pig could be transferred to another, using spleen extract or a 50% ammonium sulphate precipitate obtained from the spleen extract. On the basis of these results it is concluded that guinea-pigs are naturally sensitized to antigen or antigens present in Ascaris lumbricoides.

Anaphylaxis↗
PubMed1958

The pressor effect of peptone in the rat.

Peptone normally causes a rise of blood pressure in rats. Since the pressor response was not abolished or even diminished by adrenalectomy, it could not have been caused by a release of pressor substances from the adrenal glands. The group of drugs (dibenamine, dihydroergotamine, ergotamine, tolazoline, nicotine and hexamethonium) which antagonize or block the peptone-induced pressor action suggests that the pressor effect may be secondary to a release of sympathin by the stimulation of sympathetic ganglia. Since it was not possible to duplicate the pressor response to peptone by either 48/80 or histamine, the hypothesis that peptone acts by liberating histamine can be ruled out.

Adrenal Glands↗
PubMed1953

[Bradykinin].

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Bradykinin↗