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Biomedical subjects

A Prata

Publications and source records attributed to A Prata.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

[Hepatosplenic form of schistosomiasis mansoni, in relation to race and socioeconomic level, in Catolândia-Bahia].

Of 1,125 individuals, residents in an area where mansonic schistosomiasis is hyperendemic, were studied regarding the clinical forms correlated to the racial groups (indian mestizo, white, light mullato, medium mullato, dark mullato and negro) and to their socio-economic level according to a set of 16 variables. The white individuals (10.5%) showed a significantly higher incidence of the hepatosplenic forms; in the other racial groups there were similar frequencies, altogether 3.6%. Those with hepatosplenomegaly had a higher socio-economic level and when they also belonged to the white race the relative risk (2.78) was significantly higher.

Adolescent↗
PubMedDate not supplied

Specific treatment of hepatosplenic schistosomiasis can increase T-lymphocyte reactivity.

It has been recognized that Schistosoma mansoni infection causes depression of T-cell responsiveness. In this study we have evaluated whether immunodepression associated to schistosomiasis could be reverted by specific treatment. T-cell immune response was assessed by means of intradermal tests using recall antigens in a group of 22 patients with hepatosplenic schistosomiasis, one year after treatment with oxamniquine and compared with a group of untreated hepatosplenic patients. Only 27% of treated patients presented complete anergy to all tested antigens, in marked contrast to 80% unresponsiveness showed by hepatosplenic patients without treatment. Although most of the treated individuals showed some response to the tested antigens, in some individuals this unresponsiveness still persisted after treatment. Anergy was not found in any normal individual of the control group. It was concluded that Schistosoma mansoni infected patients may recover their normal immune responsiveness after the elimination of the worm by treatment.

Adult↗
PubMedDate not supplied

Fulminant hepatitis with microvesicular steatosis (a histologic comparison of cases occurring in Brazil--Labrea hepatitis--and in central Africa--Bangui hepatitis).

A similar histopathologic picture of fatal hepatitis associated with widespread acute fatty changes in hepatocytes and single-cell necrosis was seen in epidemic cases occurring in two distinct equatorial areas having high prevalences of HBV and HDV infections. The cases were previously considered to be two different entities; Labrea hepatitis in Brazil, and Bangui hepatitis in the Central African Republic. However, the histopathologic findings suggest that they are pathogenetically and etiologically related to HBV and HDV infections, probably modified by some as yet unknown factor(s) present in equatorial forest zones.

Adolescent↗
PubMedDate not supplied

[A longitudinal radiologic study of the esophagus in an endemic area of Chagas' disease over a 6-year period].

A longitudinal study over six years was undertaken of 494 residents of the municipality of Mambaí, Goiás. Two hundred and twelve (43%) were seropositive in 1975/76 and 199 of 464 of the same patients group, positive in 1980/82 (42.8%). At both examination single radiographs of the oesophagus were obtained immediately after ingestion of 75 ml of barium sulphate solution and a second X-ray taken one minute later. Among the 201 seropositive patients without megaesophagus in the first study 4 (2%) evolved megaesophagus during the six years of observation. During this time, using Rezende's classification, patients with established megaesophagus, changed their group in the following manner. Only one Group I patient changed to group II. Only one group II patient progressed to group IV. Progress of megaesophagus in the affected patients occurred in 2.8% of 212 patients. Also four patients with grade I megaesophagus initially had a normal oesophagogram on the follow up examination. Ten patients had doubtful oesophagogram initially and six on follow up, 75% of these patients were seropositive. This study could indicate that a doubtful oesophagogram is an early sign of megaoesophagus.

Adult↗
PubMedDate not supplied

[Mefloquine chemoprophylaxis of malaria in the Brazilian Amazonia].

In a randomised double-blind study 122 volunteers living in an endemic malarious area in Amazonian Rondônia state were divided into 4 groups to study malaria suppression. . The first group received 500 mg of mefloquine every month, group II 250 mg every two weeks, group III a tablet of Fansidar (500 mg sulphadoxine + 25mg pyrimethamine) a week and group IV placebo. Acute attacks of malaria occurred in one individual in group I, 2 subject in group II, and 6 individuals in groups III and IV. Protection with mefloquine was significant compared with the placebo group. Both treatment regimens with mefloquine were effective suppressants in an area of high prevalence of drug multiresistant Plasmodium falciparum transmission.

Adolescent↗
PubMedDate not supplied

[Longitudinal radiologic study of the esophagus, in an endemic area of Chagas disease, in a period of 13 years].

A radiological study of the oesophagus of a cohort of patients was carried during a 13 year period in the municipality of Mambaí Goiás. Barium swallow findings were recorded on 70mm film using a portable machine. Of 731 patients examined 382 (52.3%) were seropositive for T. cruzi. The sexes were equally divided. The incidence of detectable megaoesophagus was 7.9% among the cohort and 14.2% in the seropositive individuals. Progression of the disease was noted during this longitudinal study in 21.7% of males and 16.6% of females.

Adolescent↗
PubMedDate not supplied

[Anisocoria in the chronic phase of Chagas' disease].

To compare the frequency of anisocoria in patients with chronic Chagas' disease a prospective double-blind study was done in 131 patients with positive serology for Chagas' disease and 138 negative, at Mambaí (GO-Brazil), which is an endemic area for Chagas' disease. To detect anisocoria, pupillometry was done with a millimetric ruler. Anisocoria was seen in 10(7.6%) patients with Chagas' disease and in 3(2.1%) normal subjects. The chi-square test showed statistical significance at level of 5%. Chagas' disease must be included among the causes of anisocoria.

Adult↗
PubMedDate not supplied

[The epidemiological aspects of taeniasis-cysticercosis in an endemic area of Lagamar, Minas Gerais].

An epidemiological inquiry of humancysticercosis due to Taenia solium was carried out in Lagamar, Minas Gerais State, Brazil, in 1992. A survey of 1109 houses with 3344 inhabitants was made. The inquiry included 875 (86%) families and the questionnaire was answered by an informer, who was the father in 80% of the cases. One hundred pigsties, sheltering 406 swines in extremely precarious conditions, were found in 100 (11.4%) houses. A history on taeniasis in some member of the family was verified in 300 (34.2%) houses. A history of seizures was referred to by 125 (14.2%) of families. The outset of convulsion in adult age was characterized in 39 (37.8%) families. A history of mental disorder was reported in 53 (6.0%) of houses. Stool examinations were positive for Taenia spp in 24 (1.3%) of samples examined.

Animals↗
PubMedDate not supplied

SPf66 vaccine trial in Brazil: conceptual framework study design and analytical approach.

This paper describes the study population and the study design of the phase III field trail of the SPf66 vaccine in Brazil. Assessment of validity and precision principles necessary for the appropriate evaluation of the protective effect of the vaccine are discussed, as well as the results of the preliminary analyses of the gathered data. The analytical approach for the estimation of the protective effect of the vaccine is presented. This paper provides the conceptual framework for future publications.

Adolescent↗
PubMedDate not supplied

Antibody response to Salmonella typhi in human schistosomiasis mansoni.

Antibody response to Salmonella typhi O and H antigens was evaluated in 24 individuals with either hepatointestinal or hepatosplenic schistosomiasis mansoni before and after typhoid vaccination, and compared with that of non-infected controls. Before vaccination, Schistosoma-infected patients showed a higher frequency of positive antibody to O antigen and the same frequency to H antigen when compared with that of healthy individuals. However, those with hepatosplenic schistosomiasis showed higher titres of antibody to H antigen than those with hepatointestinal disease or healthy individuals. Infected subjects, particularly those with hepatointestinal disease, showed a decreased response after typhoid vaccine. This diminished ability to mount an immune response towards typhoid antigens during schistosomiasis may interfere with the clearance of the bacteria from blood stream and, therefore, play a role in the prolonged survival of salmonella as observed in some patients with chronic salmonellosis associated with schistosomiasis.

Adolescent↗
PubMedDate not supplied

Safety evaluation of SPf66 malaria vaccine in Brazil.

The frequency and description of side effects secondary to the subcutaneous application of SPf66 malaria vaccine and placebo are reported for each dose of application in the participants of the vaccine efficacy trial in Brazil. Side effects evaluated two hours after each application were detected in 8.0%, 30.2% and 8.8%, for the 1st, 2nd and 3rd dose, respectively, in the SPf66 group, and in 7.0%, 8.5% and 2.9% in the placebo group. Local reactions such as mild inflammation, nodule and pain or erythema frequently accompanied by pruritus were the most common reactions detected in both groups (3.8%, 29.1% and 8.5% in the SPf66 group and 4.0%, 7.6% and 2.5% in the placebo group). Among vaccinees, local side effects after the 2nd dose were more frequent in females. Systemic side effects were expressed mainly through general symptoms referred by the participants and were most frequent after the 1st dose in both groups (4.3% in the SPf66 group and 3.0% in the placebo group). Muscle aches and fever were referred by few participants. No severe adverse reactions were detected for either dose of application or group.

Adolescent↗
PubMedDate not supplied

[The pupil in the chronic phase of Chagas disease and the reaction to pilocarpine and phenylephrine].

To develop a method to analyse pupillary disturbances in patients with chronic Chagas disease in an endemic area, ten chagasic and ten normal subjects were matched according to sex, age and race. Pupillary diameter and area were determined using projection and topography techniques and compared between groups. Both pupils were visualised simultaneously. In each case three photographs were taken under standardised illumination. The first photo was obtained without medication, the second, 30 minutes after instillation of 0,1% pilocarpine and the last 30 minutes after instillation of 3% phenylephrine (60 minutes after pilocarpine). Pupils of chagasic patients had a statistically significant greater initial diameter and area, irregularity of the pupil border, greater percentual reduction in diameter and area after pilocarpine 0.1% and greater percentual increase in diameter and area after 3% phenylephrine eyedrops. The method developed for this study was considered satisfactory. The results suggest ocular autonomic nervous system disturbances in chagasic patients.

Chagas Disease↗
PubMedDate not supplied

Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis.

Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.

Animals↗
PubMedDate not supplied

Risk factors associated with taeniasis-cysticercosis in Lagamar, Minas Gerais State, Brazil.

An epidemiological survey was carried out in 3,344 people of an urban town in Lagamar, Minas Gerais, Brazil--during 1992-1993, to evaluate the main risk factors related to taeniasis and cysticercosis. A total number of 875 (78.9%) houses were visited and 1080 (32.3%) subjects were clinically examined. Poor sanitary conditions were positively associated with former history of taeniasis or seizures in households (p < 0.05). It was remarkable the positive relationship between taeniasis and seizures when households were questioned and subjects were clinically evaluated (p < 0.05). The relative risk of seizures was 2.3 between households and 1.7 for individuals clinically examined respectively. The breeding of swine nearby and the chronic carriers of taeniasis are determinant factors in the maintenance of the epidemiological link between taeniasis and cysticercosis in endemic areas.

Adolescent↗