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R Frade

Publications and source records attributed to R Frade.

62 records · Page 4Linked to original sources
PubMed1976

[Study of the mechanism of the effect of extracellular pH on the synthesis of the oxidative complex (cytochrome a+a3) of Bacillus coagulans: relationship to the "glucose effect" and role of excreted coproporphyrin III (author's transl)].

During the "respiratory adaptation" of Bacillus coagulans, it was possible to dissociate the kinetics of cytochrome a and a3 synthesis with carbon monoxide. The synthesis of cytochrome a3 is preferentially repressed when the pH of the incubation medium is pH 6.5 instead of pH 5.5. However, though the total synthesis of tetrapyrrole compounds is the same at both pH values, the excretion of coproporphyrin III is much increased at pH 6.5. Bacillus coagulans, sensitive to the "glucose effect", shows the "pH effect" only in the presence of high glucose concentrations. The repression of the oxidase complex synthesis by a slight increase of the extracellular pH appears directly related to the increase of the extracellular coproporphyrin III.

Aerobiosis↗
PubMedDate not supplied

[C3 stimulates the proliferation of human pre-B Raji cells].

In a defined medium in which transferrin (3 micrograms/ml) was the only source of exogenous proteins, Raji cells of the human pre-B lymphoblastoid cell line died within 48 h after forming polykaryons. The simple addition of purified C3 at a concentration equal to or higher than 3 micrograms/ml allowed Raji cells to divide. This preliminary report provides a defined system for studying the mitogenic effect of human C3 or C3 fragments upon proliferation of human B-cells lines.

B-Lymphocytes↗
PubMedDate not supplied

Expression of complement receptors (CR1 and CR3) and Fc gamma RIII on polymorphonuclears from patients with spondylarthropathies.

We assessed the expression of complement receptors (CR1 and CR3) and Fc gamma RIII on unstimulated and FMLP activated polymorphonuclears (PMNs) by indirect immunofluorescence and flow cytometry using CD35 (CR1), CD11b (CR3) and CD16 (Fc gamma RIII) monoclonal antibodies in 24 patients with spondylarthropathies (SpA) and in 18 healthy subjects. SpA patients were classified into 3 groups according to the severity of the disease (severe = asymmetrical peripheral joint involvement and permanent limitation of spine motion; moderate = one of the two items, mild = none of the items). CR1 and Fc gamma RIII expression were significantly decreased in patients with mild SpA, whereas CR1 and CR3 expression were significantly increased in patients with severe disease as compared to control subjects. In patients with mild disease, CR1 expression increased after FMLP activation, but remained significantly lower than in control subjects. The results were confirmed by immunoelectroblotting. These findings suggest that membrane and intracellular pools of CR1 and CR3 may contribute to the clinical modulation of the spondylarthropathies.

Adult↗