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Biomedical subjects

L M Silva

Publications and source records attributed to L M Silva.

36 records · Page 2Linked to original sources
PubMed1997

[Women's opinion on abortion legalization in a middle size county in southern Brazil].

INTRODUCTION: Induced abortion is the main cause of maternal death in Brazil. Question of its legalization has been the subject of frequent discussion. MATERIAL AND METHOD: In order to assess the influence of the variables affecting the opinion of women of reproductive age, a population-based systematic sample in the county of Rio Grande (Southern Brazil) was examined. RESULTS: Of a total of 1,456 interviews 30% endorsed the legalization, whatever the circumstances; this percentage was directly associated with age, schooling, family income and previous induced abortion (p < 0.01). Adjusted analysis using logistic regression showed a significant effect of schooling and previous induced abortion on favourable opinion. CONCLUSION: Schooling and previous induced abortion were the main determinants of women's favorable opinions regarding abortion legalization.

Abortion, Induced↗
PubMed1997

Comparison of nitrogen mustard, cytarabine and dacarbazine as pleural sclerosing agents in rabbits.

We have previously shown that the intrapleural injection of mitozantrone but not bleomycin resulted in pleural fibrosis. Mechlorethamine hydrochloride (nitrogen mustard) was used extensively in the past to control malignant effusions, with relatively good success. The objective of this study was to determine if the intrapleural injection of nitrogen mustard would produce pleural sclerosis in our experimental model in rabbits. We therefore evaluated sclerosing capabilities of nitrogen mustard as well as those of cytarabine and dacarbazine. Nitrogen mustard (0.4 and 0.8 mg x kg(-1)), cytarabine (3, 6 and 20 mg x kg(-1)) and dacarbazine (4, 8 and 20 mg x kg(-1)) were instilled intrapleurally into anaesthetized rabbits. Twenty eight days after the instillation, the animals were killed, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The intrapleural injection of 0.8 mg x kg(-1) nitrogen mustard was effective in creating pleural fibrosis, either grossly or microscopically. The mean degree (scale 0-4) of gross pleurodesis in the rabbits that received 0.8 mg x kg(-1) nitrogen mustard was 3.2+/-1.0 and the mean degree of microscopic pleural fibrosis was 3.5+/-0.8. The intrapleural injection of 0.4 mg x kg(-1) nitrogen mustard and the different doses of cytarabine (3, 6 and 20 mg x kg(-1)) and dacarbazine (4, 8 and 20 mg x kg(-1)) were ineffective in producing pleurodesis. From this study, we conclude that the intrapleural injection of 0.8 mg x kg(-1) of nitrogen mustard produces clinically significant pleurodesis in rabbits. Consideration should be given to future clinical studies utilizing 0.6-0.8 mg x kg(-1) nitrogen mustard intrapleurally for the treatment of malignant pleural effusion.

Animals↗
PubMed1996

Effectiveness of sodium hydroxide as a pleural sclerosing agent in rabbits: influence of concomitant intrapleural lidocaine.

The two agents that have been used most commonly to produce a pleurodesis are tetracycline and bleomycin. Tetracycline is no longer generally available because of more stringent requirements on the manufacturing process. Bleomycin is very expensive. Therefore, alternative agents are necessary particularly in developing countries. The objective of this project was to determine whether 0.5% sodium hydroxide is an effective sclerosant in an experimental model in rabbits. Sodium hydroxide (NaOH) (2 ml of 0.5%) was instilled intrapleurally in 24 anesthetized male rabbits. Half the rabbits received 1 ml of 2% lidocaine 3-5 min before the NaOH. Twenty-eight days after the instillation, the animals were sacrificed, and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The results indicated that the intrapleural injection of NaOH was effective in creating a pleurodesis only if the animals were not premedicated with lidocaine. The mean (+/- S.D.) degree of gross pleurodesis after NaOH alone 2.8 (1.0) was significantly (p < 0.001) greater than after that following the combination 1.3 (0.5). We conclude that NaOH is an effective pleural sclerosant but that it is ineffective if it is injected concomitantly with lidocaine.

Anesthetics, Local↗
PubMed1996

Is immunogenetic susceptibility to neuropsychiatric systemic lupus erythematosus (SLE) different from non-neuropsychiatric SLE?

OBJECTIVES: To analyse frequency of HLA class II antigens (DR and DQ) and lymphocytotoxic autoantibodies in patients with systemic lupus erythematosus (SLE) and subsets with or without neuropsychiatric involvement. METHODS: Ninety three patients with SLE (42 with neuropsychiatric features) were typed for HLA class II antigens and investigated for the presence of lymphocytotoxic autoantibodies by a complement dependent microlymphocytotoxicity assay. A total of 191 controls of similar ethnic background were also typed for HLA antigens. RESULTS: HLA-DR3 antigen was increased in the total group of patients with SLE (p = 0.003) and in the neuropsychiatric group (p = 0.002). HLA-DR4 antigen frequency was increased in non-neuropsychiatric patients (p = 0.001) and decreased in patients with neuropsychiatric SLE (p = 0.0005). Comparisons of HLA frequencies between subgroups of patients showed decreased HLA-DR4 (p < 0.0001) and increased HLA-DR9 and HLA-DQ2 antigens (p = 0.0008 and 0.005 respectively) in the neuropsychiatric group. The frequency of lymphocytotoxic autoantibodies was increased in neuropsychiatric patients with SLE having HLA-DR9 specificity (p = 0.04). CONCLUSION: HLA-DR4 may have a protective specificity for the development of neuropsychiatric features of SLE and HLA-DR9, in addition to HLA-DR3, and the presence of lymphocytotoxic auto-antibodies may predispose to neuropsychiatric abnormalities.

Adolescent↗
PubMed1995

Corynebacterium parvum versus tetracycline as pleural sclerosing agents in rabbits.

Tetracycline has been one of the most commonly used agents for producing a pleurodesis. However, it is no longer available due to more stringent requirements on the manufacturing process. The objective of this project was to determine whether Corynebacterium parvum is an effective sclerosant in an experimental model in rabbits. The following medications were instilled intrapleurally in anaesthetized male rabbits: tetracycline 35 mg.kg-1 or C. parvum 4 or 8 mg, all diluted with bacteriostatic saline solution. Twenty eight days after the instillation, the animals were sacrificed and the pleural spaces assessed macroscopically for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The intrapleural injection of C. parvum was ineffective in creating pleural fibrosis. The mean degree of pleurodesis in the 10 rabbits who received tetracycline was 3.5 +/- 0.7 (scale 0-4) whilst in the 10 rabbits that received 4 mg C. parvum it was 0.0 +/- 0.0, and in the 10 rabbits that received 8 mg C. parvum it was 0.5 +/- 0.8. Based on this study, we recommend that C. parvum should not be used as a pleural sclerosant in patients with normal pleura.

Animals↗
PubMed1995

Comparison of silver nitrate and tetracycline as pleural sclerosing agents in rabbits.

The ideal agent to produce pleurodesis has not been identified. Tetracycline, the drug used most commonly in the 1980s, is no longer available. Talc either aerosolized or in a slurry is the agent used just most commonly at the present time, but there are concerns about its safety. Another possibility is silver nitrate, which was widely used in the past, but was abandoned on account of side effects. We hypothesized that lower concentrations of silver nitrate than had been used in the past would be effective in creating a pleurodesis in rabbits. The following medications in a total volume of 2 mL were instilled intrapleurally in three groups of ten anesthetized rabbits: 0.25% or 0.50% silver nitrate and 35 mg/kg tetracycline. Twenty-eight days after the injection, the animals were sacrificed and the pleural spaces were assessed grossly for evidence of pleurodesis and microscopically for evidence of fibrosis and inflammation. The intrapleural injection of 0.50% silver nitrate produced an effective pleurodesis. The mean degree of gross pleurodesis in the rabbits that received 0.50% silver nitrate (3.4 +/- 1.2) did not differ significantly from that of the rabbits that received tetracycline (3.5 +/- 0.7) (scale 0 to 4). The mean degree of microscopic pleural fibrosis in the rabbits that received 0.50% silver nitrate (3.4 +/- 0.7) did not differ significantly from that of the rabbits that received tetracycline (3.9 +/- 0.3). However, 0.25% silver nitrate was ineffective in creating pleural fibrosis, either grossly or microscopically. No rabbits died after the intrapleural injection of the drugs. There were no observed side effects after the injection of silver nitrate. The present study demonstrates that 0.50% silver nitrate instilled into the pleural space is an effective agent for producing pleurodesis in the rabbit; its effect is comparable to tetracycline 35 mg/kg. This agent should be compared with tetracycline derivatives and talc in studies in humans.

Analysis of Variance↗
PubMed1994

Unsuspected rheumatic fever carditis ending in heart transplantation.

A 25-year-old female patient with presumed peripartum cardiomyopathy was submitted after two years to orthotopic heart transplantation. Pathological examination of the excised heart revealed acute rheumatic fever. Five days after the transplantation persistent fever developed. The patient's condition deteriorated until death after six weeks, which was attributed to cytomegalovirus disease.

Adult↗
PubMed1994

[Infective endocarditis in patients with permanent pacemaker].

Five patients who had permanent pacemaker and infective endocarditis were analyzed. Diagnose was confirmed by a positive blood cultures in all patients and 2 of them had identifiable vegetation in the echocardiogram too. The etiologic agent was Staphylococcus aureus in 3, Staphylococcus epidermidis in 1 and Staphylococcus viridans in 1. Three patients were treated with antibiotics alone: one had no clinical conditions to be operated, one died before surgery and one had good response to antimicrobial therapy alone. Two patients were submitted to antibiotic therapy and surgical removal of the pacemaker system, without complications. It was concluded that the surgical removal of the pacemaker system, as soon as possible, is the choice's therapy.

Adult↗
PubMed1985

Purification and partial characterization of an arginine ester hydrolase from the venom of the bushmaster snake, Lachesis muta noctivaga.

An arginine esterase was purified from the venom of Lachesis muta noctivaga by gel filtration on Sephadex G-100 and by affinity and DEAE cellulose chromatography. The purified enzyme preparation had an arginyl esterase specific activity of 181 mumoles/min/mg, which was 10.9-fold higher than the esterase activity found in the crude venom. The enzyme is free of kinin-releasing activity (kininogenase) and thrombin-like activity (fibrinogenase). The purified fraction showed a single band on polyacrylamide gel electrophoresis. The Km for Bz-L-Arg-O-Et is 1.14 X 10(-3)M, Vm 181.7 mumoles/min/mg and Kcat 90.9 sec-1. The pH profile indicates that the enzyme has an active region centered at pH 8.1. L. muta noctivaga arginyl esterase is reversibly inhibited by benzamidine (Ki 8.9 X 10(-4)M) and irreversibly inhibited by diisopropyl fluorophosphate.

Animals↗
PubMed1985

Enterotoxin production, presence of colonization factor antigen I, and adherence to HeLa cells by Escherichia coli O128 strains belonging to different O subgroups.

Strains of three subgroups of Escherichia coli O128 were studied. Enterotoxin production was observed in 30 (91%) O128ac strains, whereas strains of subgroups O128ab and O128ad were not toxigenic. CFA/I was only found in two serotypes of subgroup O128ac, all of them producing heat-stable enterotoxin except for one which produced both toxins. None of the strains studied produced CFA/II. In a binding test with HeLa cells, localized adherence was found only in strains of subgroup O128ab; diffuse adherence occurred in strains of subgroup O128ac. As flagellar antigens were specific in subgroups ab and ac and toxin production was observed only in subgroup ac, the present results suggest that subgroup and serotype are useful markers for O128 strains that are enterotoxigenic or enteropathogenic.

Antigens, Bacterial↗
PubMedDate not supplied

Immunostimulation as adjuvant for the chemotherapy of experimental schistosomiasis.

Immunosuppressed animals respond poorly to schistosomal chemotherapy and a proper response can be restored by the administration of immune serum. Present study attempts to search whether immunological stimulation would increase drug effectiveness. Swiss mice infected with 50 S. mansoni cercariae were later treated with complete Freund's adjuvant. Treatment with oxamniquine was made with 100 mg/kg.b.w., 25 mg/kg.b.w. and 50 mg/kg.b.w., the last two doses representing a fourth and a half of the recommended curative dose. Appropriate controls for the drug, the adjuvant and the infection were also studied. The serum-level of anti-S. mansoni antibodies (ELISA) and recovery of worms by perfusion of the portal vein system were the evaluated parameters. Statistical analysis of the results failed to reveal significant differences in worm recovery between adjuvant-stimulated animals treated with oxamniquine and any of the treated controls receiving the same amount of the drug. Although total lack of immunity interferes with curative treatment the usual immune response seems to be sufficient to allow for curative drug action in schistosomiasis and thus apparently does not need to be artificially stimulated.

Animals↗
PubMedDate not supplied

An experimental approach to the pathogenesis of "pipestem" fibrosis (Symmers' fibrosis of the liver).

Pathogenesis of schistosomal hepatic fibrosis ("pipestem" fibrosis of the liver) was investigated by means of the murine model. Although worm load appears as the main pathogenetic factor, alone it is not sufficient to produce that characteristic lesion. By comparing the findings in animals with heavy and prolonged Schistosoma mansoni infection, which developed or not "pipestem" fibrosis, it was observed that the lesion was more frequent in intact animals than in the splenectomized one. However, the size of the spleen, the number of recovered worms, the number of eggs per gram of liver tissue, the level of serum idiotype and anti-idiotype antibodies, the size and volume of periovular granulomas formed in the liver, all that failed to show statistically significant differences between the two groups. After analysing all these data, other factors, that apparently have been hitherto negleted, rested to explain the findings. Among them, the timing and sequence of the egg-induced intrahepatic vascular changes seemed crucial. The sequential development of intrahepatic portal vein obstruction, followed by the opening of periportal collateral veins and the continous arrival of schistosome eggs going to be lodged into the latter, appeared as essential steps in the pathogenesis of "pipestem" fibrosis.

Animals↗
PubMedDate not supplied

Significance of schistosomal granuloma modulation.

Hepatic Schistosoma mansoni periovular granulomas undergo changes in size, cellular composition and appearance with time. This phenomenon, known as "immunological modulation", has been thought to reflect host immunological status. However, as modulation has not been observed outside the liver, participation of local factors, hitherto little considered, seems crucial. Components of the extracellular matrix of periovular granulomas of the mouse were particularly studied in three different organs (liver, lung and intestine) and during three periods of infection time (acute, intermediate and chronic) by means of histological, biochemical and immunofluorescence techniques, while quantitative data were evaluated by computerized morphometry, in order to investigate participation of local factors in granuloma modulation. Results confirmed modulation as a exclusively hepatic phenomenon, since pulmonary and intestinal granulomas, formed around mature eggs, did not change size and appearance with time. The matricial components which were investigated (Type I, III and IV collagens, fibronectin, laminin, proteoglycans and elastin) were found in all granulomas and in all organs examined. However, their presence was much more prominent in the liver. Elastin was only found in hepatic granulomas of chronic infection. The large amount of extracellular matrix components found in hepatic granulomas was the main change responsible for the morphological aspects of modulation. Therefore, the peculiar environment of the liver ultimately determines the changes identified in schistosomal granuloma as "modulation".

Animals↗
PubMedDate not supplied

[A research agenda for health policies and services in northeast Brazil].

The aim of this paper is to gather elements for a discussion on health policies and services in northeast Brazil. The author begins with an analysis of the population's main health problems, the health system's limitations, and current opportunities for implementing health programs. She highlights the following research priorities: people's health situations according to their material living conditions and life styles; the private health sector's characteristics and development; the current decentralization process; and proposed innovations in services, programs, and systems. The author points out further that the policy-making process in science and technology should assure a balance between researchers' freedom and people's health needs, regional focus, and universal issues.

Brazil↗
PubMedDate not supplied

[Decline and social inequalities of infant mortality caused by diarrhea].

This ecological study describes the temporal trend from 1977 to 1998, and spatial patterns of infant mortality from diarrhea in the city of Salvador, Bahia State, Brazil. The annual proportional of infant mortality and specific-cause mortality rate were estimated. Spatial units of geographical zones within the city's urban area were utilized for administrative purposes, which were aggregated according to quartile of living conditions indicators. Over the study period, the diarrhea-induced infant mortality rate decreased 91.9%. The mortality risk from diarrhea in the lowest living condition strata was 90% greater than in the highest conditions. Also, infant mortality due to diarrhea increases proportionally as living conditions worsen, which necessitates a review of the control policies concerning this important public health problem. Although the infant mortality rate declined during the study period, social inequalities related to infant mortality due to diarrhea persist, reflecting a continuing poor social development.

Brazil↗