Effect of tannic acid on benzo[a]pyrene-DNA adduct formation in mouse epidermis: comparison with synthetic gallic acid esters.

Tannic acid, a naturally occurring plant phenol, was shown to inhibit the mutagenicity and/or tumorigenicity of several polycyclic aromatic hydrocarbons in mouse skin. In this study the effect of topical application of tannic acid on epidermal aryl hydrocarbon hydroxylase, glutathione S-transferase, and binding of benzo[a]pyrene (B[a]P) to epidermal DNA was compared with the activity of synthetic gallic acid esters. Single topical application of 8 mumol octyl and dodecyl gallate had no effect on the induction of aryl hydrocarbon hydroxylase, whereas propyl gallate and tannic acid increased the enzyme activity by nearly 200%.

The application of a flow cytometric assay for evaluation of phagocytosis of neutrophils.

Phagocytosis and the release of oxidative products generated by the respiratory burst have been studied in vitro under the influence of non-steroidal anti-inflammatory drugs: naproxen and ibuprofen, using phagocytes of peripheral blood from healthy human donors. Phagocytosis was monitored by flow cytometry in order to investigate the uptake of propidium iodide-labelled bacteria (Staphylococcus aureus) by polymorphonuclear leucocytes. In addition, the phagocytic capacity and percentage of killed bacteria was measured in isolated neutrophils using the Pantazis & Kniker method.

Inhibition of the vitamin B12 binding capacity of proteins by the hydrolysis product of cyclophosphamide.

The inhibitory effect of cyclophosphamide hydrolysis product (CPHP) on vitamin B12 binding ability to proteins has been established. The ester N-(2-chloroethyl)-N'-(3-phosphopropyl)-ethylenediamine hydrochloride is probably responsible, in vitro, for blocking the protein binding sites. Preincubation of proteins with vitamin B12 prevents the inhibitory effect of CPHP.

[Sialic acid level in blood platelets after cryopreservation with DMSO].

Plasma platelet concentrates of man were subjected to preparatory procedures with dimethylsulphoxide (DMSO) as a cryoprotective agent. It was demonstrated that DMSO acting directly on the platelets in concentrations used in routine preparation had no effect decreasing the level of sialic acids in the platelets. Cryopreservation of platelets in presence of DMSO caused the loss of 30% of the sialic acids from the platelets.