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D P Ramos

Publications and source records attributed to D P Ramos.

4 recordsLinked to original sources

Biological activity of chronic phase antibodies eluted from sensitized Trypanosoma cruzi trypomastigotes.

Chronic infection with Trypanosoma cruzi induces high levels of antibodies that have lytic and clearance activities on bloodstream trypomastigote forms. These two activities were tested with antibodies eluted from parasites sensitized with serum obtained from mice in the chronic phase of infection. Parasites submitted to treatment for antibody elution were also tested. Our results show that antibodies eluted from the parasites are very efficient to induce lysis but unable to induce clearance. In addition, we observed that after being submitted to treatment for antibody elution the parasites still presented a slower but significant clearance and a high lytic activity. These results allow us to suggest that clearance inducing antibodies are mostly high affinity antibodies that could not be eluted from the parasites in our experimental conditions.

Animals↗

Clearance-inducing antibodies are responsible for protection against the acute phase of Trypanosoma cruzi infection in mice.

A study was conducted on mice infected with strains Y and CL of Trypanosoma cruzi. The ability of anti-Y and anti-CL sera to induce complement-mediated lysis, immune clearance and protection against the acute phase of the infection was studied using homologous anti-Y or anti-CL serum tested with the Y or CL strain, or heterologous anti-Y serum tested with the CL strain or anti-CL serum tested with the Y strain. Complement-mediated lysis was induced by both homologous and heterologous antisera but protection was afforded only by homologous antisera. Immune clearance was induced by homologous but not by heterologous antisera. Antisera with high clearance ability were able to confer protection whereas antisera with high lytic ability were not. These results show a high correlation between the antibody ability to induce clearance and to confer protection and suggest that clearance rather than lysis is responsible for protection against the acute phase of the infection. The mechanism of antibody protection against the acute phase of the infection is discussed.

Animals↗

Omeprazole-induced exfoliative dermatitis.

A 41-year-old man being treated for severe esophageal reflux disease developed red, exfoliative scaling on his back, trunk, and legs after taking omeprazole 20 mg twice/day for 3 months. He also had redness and extreme sloughing of the skin on his hands. Even after he discontinued omeprazole and after several courses of topical and systemic steroids, symptoms continued to occur 18 months after treatment, mostly localized to the hands. Exfoliative dermatitis is associated with many drugs, but omeprazole has been implicated only once before in the literature.

Adult↗