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Biomedical subjects

J B Vieira

Publications and source records attributed to J B Vieira.

At least 19 recordsLinked to original sources
PubMed2005

Unusual micelle and surface adsorption behavior in mixtures of surfactants with an ethylene oxide-propylene oxide triblock copolymer.

Micellization and adsorption at the air-solution interface of binary mixtures of the triblock copolymer of ethylene oxide and propylene oxide, EO23PO52EO23 (EPE), and the surfactants sodium dodecyl sulfate (SDS), dodecyl trimethylammonium chloride (DTAC), and tetraethylene glycol monooctyl ether (C8EO4) have been studied by neutron reflectivity and surface tension. The synergistic attractive interaction between the polymer and the ionic surfactants has been analyzed in the framework of the pseudo phase approximation and gives rise to a stronger interaction for EPE/SDS than EPE/DTAC. In contrast, the interaction of the nonionic surfactant C8EO4 with the copolymer EPE shows an unexpected and rather different behavior, resulting in a strongly repulsive interaction, characterized by a positive interaction parameter. The neutron reflectivity measurements of the surface excess, where the predicted and measured surface excesses are directly compared, provide evidence that challenges the applicability of the pseudo phase approximation for describing the surface mixing behavior. Structural information on the mixed adsorbed layer provides evidence which in part explains the observed discrepancies between the measured surface excesses and the behavior predicted from the pseudo phase approximation. Furthermore the structural evidence can be use to rationalize the differences in behavior observed between the ionic and nonionic surfactants.

Journal Article↗
PubMed2000

[Peridomiciliary changes and implications for Triatoma brasiliensis control].

A total of 9,906 annexes from 1,541 rural dwellings of Boa Viagem County, Ceará, Brazil, infested by Triatoma brasiliensis and Triatoma pseudomaculata were investigated and immediately sprayed with pyrethroid insecticide, followed by revisions at 6, 12, and 18 months. The initial infestation rate of annexes was 4.0%, with predominant infestation in animal shelters (7.0%). Mean insect density was low, regardless of triatomine species or type of annex. A progressive decrease in the number of initial annexes was observed (66% of remaining annexes), mainly those classified as "piles of materials". Only 3% of the annexes were modified by the population. New constructed annexes were important as new foci of infestation. Some 25% were infested at the end of observation period, significantly more than the "old" annexes (4.0%), a difference attributed to insecticide spraying at the beginning of the intervention. Reinfestation occurred slowly and was more frequent in animal shelters No differences were observed between traditional pyrethroid and slow-release organophosphate formulations. Selective spraying of "new" annexes is recommended.

Animals↗
PubMed2000

[Focal and total residual insecticide spraying to control Triatoma brasiliensis and Triatoma pseudomaculata in Northeast Brazil].

To efficiently control the triatomines Triatoma brasiliensis and Triatoma pseudomaculata, a field trial was performed to compare conventional versus focal spraying of deltamethrin 5% SC at 25 mg a. i./m2 and the slow-release organophosphate malathion 8.3% SR at 2g a. i./m2. The assay took place in the county of Boa Viagem, Ceará State, with 1541 households, randomly separated into 4 groups. Two of them received focal spraying: PT, treated with deltamethrin indoors and in the peridomicile, and PL, which received slow-release malathion in the same circumstances. The other groups received conventional, i.e., total application: PT with deltamethrin in the intra- and peridomicile, and PL, which was treated with deltamethrin indoors and slow-release malathion in the peridomicile. Entomological surveys at 6 and 12 months post-treatment showed better results for mixed treatment, the PL group, probably due to good indoor performance for the pyrethroid and better performance of the slow-release formulation under the hostile peridomiciliary conditions. Domestic animal shelters underwent numerous modifications over the course of the year, fostering reduced insecticide performance in the peridomicile.

Animals↗
PubMed1986

Controlled field trials of a vaccine against New World cutaneous leishmaniasis.

Two controlled, double blind field trials of a non-living promastigote vaccine against New World Cutaneous Leishmaniasis (NWCL) were conducted in 1981 and 1983 in Brazil. Brazilian Army conscripts were randomly assigned to the vaccine or placebo groups and tested during their training in the Amazon jungle, a high risk area for NWCL. The results obtained showed: no significant differences between the vaccine and the placebo groups with respect to a number of characteristics (age, race, previous contact with the jungle, etc.); no significant differences between the participants who got and who did not get NWCL during the trial, with respect to length of exposure, contact with the jungle, etc. and a reduction of 67.3 and 85.7% in the annual incidence rate of NWCL, in 1981 and 1983 respectively (although the difference between incidence rates of the disease in vaccinated and control groups in the 1983 trial was not statistically significant), among those vaccinated who had converted to a positive leishmanin skin test as compared with the placebo groups.

Adolescent↗
PubMed1985

[Polymioclonia-opsoclonus: Kinsbourne's syndrome. Report of a case].

Case report of a 9 years old boy with Kinsbourne's syndrome. This condition was characterized by the subacute onset of polymyoclonia, cerebellar ataxia and opsoclonus that set later, following an herpes zoster infection. Steroid therapy resulted in rapid dramatic improvement of neurological symptoms.

Adrenocorticotropic Hormone↗
PubMed1985

[Brucella meningitis: a case report].

The authors report a case of genuine brucellar meningitis etiology. Emphasis was given on endemic and epidemiologic factors in our country as well as on contradictory clinical and complementary immunological tests in lower age groups. The CT scan ruled out possibilities of tissue damage. The case had good clinical evolution. The treatment was based on dimethyl-chlortetracycline associated with trimetropin-sulfametoxazol.

Brucellosis↗
PubMed1984

[Dejerine-Roussy syndrome: report of a case].

The Déjérine-Roussy syndrome was not revised for several years by neurologists, although it has been known since 1906. The authors describe a typical case involving thalamic ischemic and calcarine other side cortex lesions emphasizing its study by computed axial tomography and by using new drugs on a vasodilatation, inhibition of platelet aggregation and tiapride base.

Humans↗
PubMed1981

Plague in Brazil during two years of bacteriological and serological surveillance.

In north-east Brazil, where plague infection is endemic, bacteriological and serological methods were employed during a two-year period to determine accurately the occurrence of human infection and to define certain epidemiological features of both human and rodent infection. There were 67 confirmed cases of plague, predominantly among males and children. Most of these cases occurred in two inland rural plateaux of Ceara State. Clustering of cases in place and time was common, as was a history of contact with rats. Peak occurrence was in November 1978, during the warm, harvest time of year. Rodent surveillance resulted in isolation of Yersinia pestis from 33 animals, most of them from the field rodent, Zygodontomys pixuna, in the States of Pernambuco and Ceara. Our results indicate a decline in the number of human cases from previous years but show that several foci remain active and that serological testing, in addition to routine bacteriological testing, can assist workers in maintaining the surveillance of both human and rodent plague in Brazil.

Adolescent↗
PubMedDate not supplied

[Preliminary activities of the program for the control and treatment of onchocerciasis in the Yanomâmi territory, Roraima, Brazil].

After to characterize the clinic and epidemiological picture of the onchocerciasis in Yanomâmi region, RR, Brazil, begun in 1993, the National Health Foundation (FNS) implemented a Control and Treatment Pilot Project in Tootobi and Balawaú. Here, it was studied skin biopsies from 426 inhabitants. In the nodules of 86.7% from patients was encountered Onchocerca volvulus. The over-all prevalence in the examined population was 66.2%. The treatment with ivermectin covered 80.1% of total population. Adverse reactions, light and moderate, of the medicament were reported in 12.3% of the patients. These results agreeing with the medical literature and suggesting the viability of to increase of the programme for all Yanomâmi area in the next phase.

Antiprotozoal Agents↗