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Biomedical subjects

A C Martins

Publications and source records attributed to A C Martins.

At least 19 recordsLinked to original sources
PubMed2001

Effects of decrease of extracellular sodium in carbachol-evoked catecholamine secretion in isolated adrenal medullae of rats.

The effect of extracellular Na(+) deprivation on the carbachol-evoked catecholamine secretion was evaluated in chromaffin cells. Isolated adrenal medullae of male Wistar rats were incubated in solutions with different sodium concentrations (144,0; 75,0; 25,0 and psi mM). Catecholamine secretions inversely increased as a response to fall of extracellular concentration of sodium. The magnitude of response to cholinergic stimulus (carbachol 100 microM) was decreased in low extracellular sodium concentration. Atropine (100 microM) inhibited secretion of catecholamine induced by carbachol in the presence and in the absence of extracellular sodium. Results suggest that in isolated adrenal medullae of rats (1) decrease in concentration of extracellular sodium increases secretion of catecholamines, perhaps by a greater influx of calcium from the extracellular environment through reversal of Na(+) /Ca(2+) exchanger; (2) intensity of catecholamine secretion induced by cholinergic stimulus seems to depend on extracellular sodium.

Adrenal Medulla↗
PubMed1999

Safety and efficacy of sildenafil in postmenopausal women with sexual dysfunction.

OBJECTIVES: Sildenafil has been demonstrated to be safe and effective in the treatment of men with erectile dysfunction. The role of sildenafil in treating women with sexual dysfunction has heretofore not been reported. The purpose of this preliminary study was to ascertain the response of postmenopausal women with self-described sexual dysfunction treated with sildenafil for 3 months. METHODS: Thirty-three consecutive postmenopausal women with sexual dysfunction based on history were entered in this open-label, nonrandomized study. All patients received 50 mg of sildenafil. Efficacy was assessed at weeks 4, 8, and 12 using a newly developed 9-item, self-administered Index of Female Sexual Function (IFSF) and a global efficacy question ([GEQ] Did treatment improve your sexual function?). The IFSF quantifies the domains of desire, quality of sexual intercourse, overall satisfaction with sexual function, orgasm, lubrication, and clitoral sensation. RESULTS: Of the group, 30 women (91 %) completed the study and were available for follow-up at 3 months. Mean baseline IFSF score before therapy was 24.8+/-9.8. Mean usage of sildenafil was 3.1+/-1.4 times per week for the duration of the study. The IFSF score improved to 29.5+/-7.6, 30.3+/-8.5, and 31.4+/-10.4 at 4, 8, and 12 weeks, respectively (P = 0.25). Mean scores for questions 2 (lubrication), 8 (orgasm), and 9 (clitoral sensation) improved by 23.2%, 7.4%, and 31.3%, respectively, at 12 weeks. Seven women (21%) noted improvement on the GEQ. Overall, only 6 (18.1%) of 33 patients had a significant (more than 60% improvement in IFSF score) therapeutic response. Clitoral discomfort and "hypersensitivity" occurred in 7 women (21%), 3 of whom withdrew from the study. Other side effects, which did not result in withdrawal from the study, included headache (n = 5), dizziness (n = 4) and dyspepsia (n = 3). CONCLUSIONS: The data suggest that sildenafil is well tolerated in postmenopausal women with sexual dysfunction. Overall sexual function did not improve significantly, although there were changes in vaginal lubrication and clitoral sensitivity. The role of sildenafil in treating sexual dysfunction in various cohorts of women remains to be determined.

Adult↗
PubMed1998

Intermittent alpha-blocker therapy in the treatment of men with lower urinary tract symptoms.

OBJECTIVES: To determine the safety and efficacy of intermittent alpha-blocker therapy in men with lower urinary tract symptoms (LUTS) in a prospective study. Alpha-blockers have been demonstrated to be safe and effective in the treatment of men with LUTS. To date, the role of varying dosing regimens in responding patients has not been well studied. METHODS: Men with LUTS were entered into this prospective open label, parallel, randomized trial. In phase 1, patients were treated with alfuzosin, 2.5 mg three times daily for 3 months. In phase 2, those patients who had a significant therapeutic response were randomized into one of the following three groups: (1) maintenance of alfuzosin; (2) alfuzosin every other day; and (3) discontinuation of alfuzosin (ie, no treatment). Patients were followed up for a total of 6 months. Parameters of evaluation included the International Prostate Symptom Score (IPSS), global satisfaction, peak urinary flow rate (Qmax), and adverse events. RESULTS: At 3 months, there were 79 patients who were categorized as having obtained a therapeutic response: IPSS decreased to 7.6 +/- 3.2 and Qmax increased to 11.3 +/- 2.9 mL/s. After randomization, IPSS was 7.1 +/- 2.9 and 6.5 +/- 2.5 for group 1; 6.5 +/- 3.2 and 6.7 +/- 2.1 for group 2; and 11.4 +/- 4.8 and 12.3 +/- 4.9 for group 3 at 3 and 6 months, respectively. Qmax was 12.7 +/- 4.8 and 11.7 +/- 5.2 mL/s for group 1; 12.2 +/- 3.9 and 11.9 +/- 3.7 mL/s for group 2; and 9.7 +/- 2.5 and 9.3 +/- 2.1 mL/s for group 3 at 3 and 6 months, respectively. Global satisfaction at 6 months was the same for groups 1 and 2. There were no differences in adverse events among the three groups. CONCLUSIONS: In men with LUTS who responded to alfuzosin, changing the dosing regimen from daily to once every other day resulted in similar efficacy and safety at 3 and 6 months. By contrast, complete cessation of alfuzosin resulted in recurrence of both symptoms and impaired urinary flow. These data provide evidence that in responding patients, intermittent alpha-blocker therapy may be a reasonable therapeutic regimen. The role of intermittent alpha-blocker therapy using other agents, as well as in a large cohort of men with LUTS, remains to be determined.

Adrenergic alpha-Antagonists↗
PubMed1992

Program design for adult learners.

The voice of adult learners is often overlooked in the design of programs that are specifically constructed to meet their learning needs. This article portrays the design of a midwifery re-registration program that commenced with a survey of non-practising midwives. The organisation of the course, together with the processes involved in curriculum building are explained. The adult learner, particularly in a situation where previous knowledge, skills and experience are vital inputs to the design of programs, have been highlighted.

Adult↗
PubMed1983

Antibody titers to Toxoplasma gondii in renal transplant patients.

Of 70 renal transplant patients submitted to the indirect immunofluorescence reaction test for toxoplasmosis, 16 (23%) had titers higher than 1/4,000, as compared to 0/41 for chronic hemodialysis patients and 0/50 for blood donors. The indirect immunofluorescence reaction titers in the renal transplant patients correlated with time since initiation of immunosuppressive therapy. Six percent (2/33) of the patients had been on immunosuppressors for less than one year, 30.7% (4/13) for 1 to 2 years, and 41.6% (10/24) for 2 or more years. The frequency of negative titers among the immunosuppressed patients was similar to that observed for blood donors and chronic hemodialysis patients. Fifty percent (8/16) of the patients with higher immunofluorescence reaction titers also had significantly high (greater than or equal to 320) positive titers in the complement fixation test. The results indicate that: 1) the immunosuppressive scheme used for the transplant patients may favor the reactivation of infection from latent Toxoplasma gondii foci, and 2) even though the patients were immunosuppressed, their antitoxoplasma antibody levels were high enough to be detected by the serologic test.

Antibodies↗
PubMed1976

Successful short-term modification of hyperacute renal allograft rejection in the primate. Intrarenal effects of phenoxybenzamine and methylprednisolone combined with heparin.

Inhibition of renal vasoconstriction during hyperacute rejection by phenoxybenzamine or methylprednisolone combined with either the antiplatelet agent pyridinolcarbamate or heparin was evaluted in primates. Phenoxybenzamine plus pyridinolcarbamate did not prolong kidney survival. Phenoxybenzamine plus heparin uniformly prolonged low rates of venous flow to 180 minutes and delayed secondary C3 consumption, sequestration of erythrocytes and platelets, coagulation, and fibrinolysis; neutrophil sequestration and vascular injury and obstruction were more marked than with heparin alone. Host pretreatment with methylprednisolone plus heparin also prolonged the low rates of venous flow to 180 minutes, further reduced secondary alterations, and resulted in the least vascular injury. When intact donor kidneys were also pretreated with methylprednisolone, persistently normal rates of venous flow were achieved. Despite marked consumption of Factor XII, the consumption of C3, other coagulation factors, prekallikrein, and sequestration of formed elements was minimal, and the histology appeared compatible with even more prolonged survival.

Animals↗
PubMed1975

[Cellular immunity in actively conditioned recipients of renal allotransplants (author's transl)].

The presence of circulating "killer" cells was demonstrated in actively "conditioned" rats with permanently accepted renal allotransplants. Immunocompetant cells of these animals were able to develop a normal graft-versus-host reaction 100 and 200 days after the transplantation. The ability of these recipients simultaneously to accept secondary donor-specific skin transplants without demonstrable immunological rejection is compatible with the concept that the cytotoxic potential of these cells in vivo is inhibited by enhancing antibodies.

Animals↗
PubMed1975

[Diffuse immunological lung damage due to heterologous anti-thymocyte serum].

Heterologous anti-rat-thymocyte-serum produces an acute hemorrhagic pulmonary lesion. Pneumotoxicity is dependant upon complement since preparatory C' - depletion protects the experimental animal from its letal properties. Absorption of serum with finely dispersed homologous tissue suspensions of lung and thymus is eliminative of toxicity while prophylactic administration of histamin antagonists seems to be non-influential in the genesis of the pulmonary lesions.

Animals↗