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R Rocha

Publications and source records attributed to R Rocha.

29 records · Page 2Linked to original sources
PubMed1992

[Concepts about AIDS among the adult population of Managua].

Nicaragua has the lowest prevalence of AIDS in Central America. In other countries where AIDS is more prevalent, the first epidemic of asymptomatic infections with human immunodeficiency virus (HIV) and the second of clinical cases of AIDS have been followed by a third epidemic of fear and discrimination. In December 1989 a study was conducted to investigate knowledge and attitudes about AIDS in a sample of 287 adults in Managua. Most of the interviewees had heard of the disease from newspapers and television, and more than 90% understood how HIV was principally transmitted. However, between one-third and one-half the interviewees believed that HIV could be transmitted by causal contact such as kissing (53%) or by mosquito bites (49%). In addition, the majority considered that isolation of HIV-infected persons and control of immigration into the country would be effective measures for preventing the spread of the disease. These results are similar to findings from studies carried out in other countries of Latin America where the HIV and AIDS epidemics started much earlier. This would suggest that the so-called "third epidemic" of discrimination and fear is affecting Nicaragua in advance of the other two.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Granulomatous hypersensitivity to Schistosoma mansoni egg antigens in human schistosomiasis. II. In vitro granuloma modulation induced by polyclonal idiotypic antibodies.

We have previously reported on Id/anti-Id-receptor interactions in clinical human schistosomiasis. These findings support a hypothesis that anti-SEA cross-reactive Id develop in some patients during the course of a chronic infection and participate in regulation of anti-SEA cellular immune responses. We report here on experiments that extend those observations to the regulation of granulomatous hypersensitivity measured by an in vitro granuloma model. T cells from chronic intestinal schistosomiasis patients were stimulated in vitro with anti-SEA Id and assayed in an autologous in vitro granuloma assay for modulation of granuloma formation. These anti-SEA Id-reactive T cells were capable of regulating autologous in vitro granuloma formation. Both CD4 and CD8 T cells could be activated to regulate granuloma formation. This regulatory activity, initiated with stimulatory anti-SEA idiotypic antibodies, was antigenically specific and was dependent on the presence of intact F(ab')2 Ig molecules. The ability to elicit this regulatory activity appears to be dose dependent and is more easily demonstrated in chronically infected intestinal patients or SEA-sensitized individuals. These data support the hypothesis that anti-SEA cross-reactive Id are important in regulating granulomatous hypersensitivity in chronic intestinal schistosomiasis patients and these cross-reactive Id appear to play a major role in cell-cell interactions that result in the regulation of anti-SEA cellular immune responses.

Animals↗
PubMed1991

Danazol therapy for cyclic thrombocytopenia.

Cyclic thrombocytopenia is a rare disease characterized by cyclic oscillations of platelet counts from very low to normal or higher. Severe hemorrhage may occur during the thrombocytopenic phase. To date, treatments for this disorder have been disappointing. Its pathophysiology is unknown. We report a successful outcome using danazol therapy. Prior to danazol treatment, the patient had a 7 year history of cyclic thrombocytopenia, refractory to glucocorticoids, splenectomy, azathioprine, vinca alkaloids, plasma infusions, and hormonal manipulation with Premarin-Provera. Her platelet counts were found to be oscillating in a 21 day cycle between 1 x 10(9)/L and 500 x 10(9)/L. Platelet-associated antibodies were positive and chromium-labeled platelet survival time was shortened. Following 2 months of danazol therapy, her platelet counts at the nadirs were significantly higher than at previous nadirs, and at no time thereafter dropped to the critically low values seen before danazol. Also at 2 months of danazol treatment, the patient reported amelioration of petechiae, and at 9 months it was completely cleared. However, platelet-associated IgG remained positive and platelet counts continued to oscillate, typically between 100 x 10(9)/L and 300 x 10(9)/L in the second year, but stabilized at 3 years, when platelet-associated IgG also disappeared. Danazol was discontinued after 3.5 years. The patient remains in unmaintained remission today, approximately 5 years after discontinuance of danazol. It can be argued that the long-term outcome was due to spontaneous remission. However, significant improvement was noted from the outset of danazol therapy, and further improvement with long-term therapy, as seen in the response of chronic ITP to danazol therapy. Danazol may offer lasting benefit in cyclic thrombocytopenia.

Autoimmune Diseases↗
PubMed1991

Granulomatous hypersensitivity to Schistosoma mansoni egg antigens in human schistosomiasis. III. In vitro granuloma modulation induced by immune complexes.

Granulomatous hypersensitivity to parasite eggs of Schistosoma mansoni is an important factor in the development of morbidity in chronic schistosomiasis. It has been demonstrated previously that the chronic, well-tolerated, intestinal form of schistosomiasis is associated with the establishment and maintenance of a variety of immunoregulatory mechanisms. We have used an in vitro model of granuloma formation for the purpose of studying the regulation of granulomatous hypersensitivity to S. mansoni egg antigens, mediated by immune complexes (IC). Our results show that the peripheral blood mononuclear cells (PBMCs) from patients with active schistosome infections, when treated with sera from chronic schistosomiasis patients, were able to induce an inhibitory activity on in vitro granuloma formation. Significant modulation of the in vitro granuloma reaction remained after treatment of PBMCs with isolated IC or manufactured IC with soluble egg antigen (SEA) and purified IgG from pooled chronic schistosomiasis sera. In contrast to granuloma modulation stimulated with whole molecule IgG-SEA IC, the incubation of PBMCs with F(ab')2 IgG-SEA IC did not induce any suppression of the granulomatous hypersensitivity to SEA. It appears in this model system that IC may inhibit the activity of granuloma formation by stimulating macrophages to release suppressive mediators. We have demonstrated this possibility by inhibition of prostaglandin activity using indomethacin. The addition of indomethacin to the granuloma culture significantly reduced in vitro granulomatous hypersensitivity to S. mansoni eggs in patients with chronic intestinal schistosomiasis and do so by inducing macrophages to secrete prostaglandins.

Alprostadil↗
PubMed1989

Long-term danazol therapy in autoimmune thrombocytopenia: unmaintained remission and age-dependent response in women.

STUDY OBJECTIVE: To assess the long-term benefit and side effects of danazol therapy, and to delineate factors influencing the responses in patients with autoimmune thrombocytopenia. DESIGN: Before and after trial. SETTING: Referral-based hematology clinics and the University of Miami teaching hospitals. PATIENTS: Data were collected on 96 patients (60 women and 36 men, 45 of whom had had splenectomies) receiving danazol therapy for autoimmune thrombocytopenia and analyzed. INTERVENTION: Danazol was added to the previous therapy or begun as an initial therapy. Glucocorticoids were tapered gradually. MEASUREMENTS AND MAIN RESULTS: The overall response rate to danazol was 61.4%. Among responders, the platelet counts (mean +/- SD) before and after danazol treatment were 36 +/- 24 x 10(9)/L and 145 +/- 77 x 10(9)/L, respectively, and the time to response was 2.7 +/- 3 months. Sex, age, and the status of the spleen (absent or present) influenced the responses to danazol. In women, but not in men, response rates improved with advancing age, especially in the nonsplenectomized women. This may be because estrogen levels are high in younger women and low in older women and men. Danazol, when given longer than a year, induced remissions lasting for years even after its discontinuation, but early relapses were frequent when danazol was administered for less than 6 months. Platelet-associated IgG returned to normal range during unmaintained remission. CONCLUSION: Danazol is best suited for long-term medical management of autoimmune thrombocytopenia. It is well tolerated, and lasting, unmaintained remissions often occur after prolonged danazol administration. Age, sex, and the status of the spleen influence the responses. When danazol therapy is used, glucocorticoids can be substantially reduced in dosage or withdrawn. Danazol is a good alternative to splenectomy in elderly persons, especially in women.

Adolescent↗
PubMedDate not supplied

Anti-idiotypic T cells in human schistosomiasis.

We have developed an in vitro model of granuloma formation for the purpose of studying the immunological components of granulomatous hypersensitivity in patients infected with S. mansoni. Our previous studies have shown that 1) granulomatous hypersensitivity can be studied by examining the cellular reactivity manifested as multiple cell layers surrounding antigen-conjugated polyacrylamide beads; and 2) this reactivity is a CD4 T cell dependent, macrophage dependent, B cell independent response which is antigenically specific for parasite egg antigens. We report here on idiotype - anti-idiotype receptor interactions involved in the regulation of granulomatous hypersensitivity in patients and former patients infected with S. mansoni. Five human monoclonal antibodies specific for parasite egg antigens were used to activate CD4 and CD8 T cell subsets. These activated anti-idiotypic T cells were then assayed for regulatory effector functions in an autologous in vitro granuloma model.

Adult↗
PubMedDate not supplied

[Nephropathic cystinosis: report of 2 cases and review of the literature].

We describe two patients with infantile nephropathic cystinosis who presented nephrogenic diabetes insipidus in addition to Fanconi syndrome. After the diagnosis was confirmed by slit-lamp examination that showed crystallization of the cornea and by the presence of cystine crystals in the bone marrow, the patients underwent conservative and supportive treatment including correction of acidosis, replacement of fluid losses and protection from bone demineralization with replacement of phosphorus, calcium and vitamin D. Patient 1 deceased after an episode of bronchopneumonia complicated by profound acidosis. Patient 2 was started on cysteamine which effectively reduce cystine in body tissues and prevents or slows progression of end-organ damage.

Adolescent↗