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Biomedical subjects

A R Silva

Publications and source records attributed to A R Silva.

32 records · Page 2Linked to original sources
PubMed1992

Interference of azelastine with anaphylaxis induced by ovalbumin challenge in actively sensitized rats.

The inhibition of the haematological alterations and prevention of death due to systemic anaphylaxis after antigen challenge were investigated in rats after various drug treatments. The i.v. injection of ovalbumin (250 micrograms/kg) into actively sensitized rats induced marked thrombocytopenia and haemoconcentration within 5 min and significant leukocytosis within 30 min, lasting for 2 h after the challenge. Pretreatment with meclizine or terfenadine (15-30 mg/kg i.p.) inhibited antigen-induced haemoconcentration, whereas WEB 2086 (2-10 mg/kg i.p.) and PCA 4248 (5-10 mg/kg p.o.), two platelet-activating factor (PAF) antagonists, interfered with thrombocytopenia only. Azelastine (1-20 mg/kg p.o.) dose dependently inhibited antigen-induced haemoconcentration and thrombocytopenia but failed to block leukocytosis. Azelastine also inhibited the thrombocytopenia observed after the i.v. administration of PAF (4 micrograms/kg). Administration of ovalbumin at a dose of 1.5 mg/kg resulted in a lethal anaphylactic reaction in about 85% of the rats. Pretreatment with WEB 2086 (10 mg/kg i.p.), meclizine (30 mg/kg i.p.) or both increased the survival rate from 15 to 57, 68 and 87%, respectively. Azelastine alone (20 mg/kg p.o.) completely blocked the lethal reaction. It was concluded that the ability of azelastine to antagonize histamine and PAF is important for its effectiveness against anaphylactic shock.

Anaphylaxis↗
PubMed1991

Toxicological and toxicogenetic effects of plants used in popular medicine and in cattle food.

Toxicological and toxicogenetic effects of aqueous (tea) and hexanic fruit extract of Indigofera suffruticosa Mill. and hydroalcoholic root extract of Solanum agrarium Stendt. were evaluated in Balb C male mice intraperitoneally exposed. A hepatotoxic effect was observed just for animals treated with aqueous fruit extract of I. suffruticosa. In relation to the toxicogenetic effect, just the group treated with 12.5% of toxic dose of aqueous fruit extract of I. suffruticosa showed a statistically significant increase in the frequency of cells with chromosome aberrations (cytogenetic effect), although a slight increase was also observed for the highest dose (25% of LD50) of hydroalcoholic root extract of S. agrarium. The results obtained show that before S. agrarium is used as medicine and before the wide use of I. suffruticosa in cattle food, careful evaluation must be done.

Animal Feed↗
PubMedDate not supplied

Changes in Saccharomyces cerevisiae development induced by magnetic fields.

Saccharomyces cerevisiae cultures exposed to 110 mT and 220 mT steady magnetic fields (SMF) were studied to observe eventual induced growth alterations and changes in metabolic activity. Cell mass (biomass) growth was evaluated by light spectrometry, and metabolic alterations were estimated on the basis of the CO2 pressure produced and by the culture media pH changes, measured at the beginning and the end of the observation. The yeast strain DAUFPE-1012, cultivated in a nonaerated liquid agar Sabouraud glucose medium, was exposed to SMF generated by NdFeBr magnets. Results showed alterations induced by 220 mT SMF as an increment in cell proliferation (1.84%) and an increased CO2 production (36.1%) as compared to control groups. Furthermore, the initial-to-final pH difference in 220 mT SMF exposed cultures was higher than the 110 mT SMF and the control values. The whole acidification and the rise in CO2 production observed after 220 mT SMF exposure did not correspond to the biomass growth values, as compared to the other cultures, and was apparently provoked by a enhancement in the cellular metabolic rate. This technique becomes very promising for future biotechnological applications in fermentative processes.

Biomass↗
PubMedDate not supplied

[Prevalence of prenatal exposure to cocaine in a sample of newborns from a university teaching hospital]

OBJECTIVE: To assess the prevalence of prenatal exposure to cocaine in a sample of newborns using two methods: fluorescence polarization immunoassay and interview with the mother. METHODS: This cross-sectional study was carried out in a university teaching hospital. The population included all live births between March 23, 1999 and June 01, 1999 (n=847). Exposure was determined by a benzoylecgonine-positive meconium specimen and/or by a positive interview with the mother. RESULTS: The prevalence of prenatal exposure to cocaine in this sample was 2.4% (16 cases) according to the interviews, and 3.4% (25 cases) according to the meconium analysis. A rate of 4.6% (34 cases) was found when both methods were associated. CONCLUSIONS: We observed that the meconium test was more effective than the maternal interview for the diagnosis of prenatal exposure to cocaine. The meconium analysis enhanced diagnostic chances by 53.4%, compared to 26% in the case of maternal interview.

Journal Article↗
PubMedDate not supplied

[Devic disease: a case report]

OBJECTIVE: To report a case of Devic disease, emphasizing its diagnosis, in addition to reviewing the medical literature. DESCRIPTION: Male, six-year-old patient suddenly developed weakness in lower limbs, with resolution during hospital stay. However, as the weakness disappeared, loss of vision occurred. The symptoms were reverted after the use of prednisone. COMMENTS: The diagnostic and therapeutic approach was similar to that used in other cases reported by different reference centers. In other words, clinical diagnosis and prednisone therapy were used, with the complete improvement of symptoms. However, there is still some controversy surrounding its etiology and relationship with other demyelinating diseases, such as multiple sclerosis.

Journal Article↗
PubMedDate not supplied

Emerging Chagas disease: trophic network and cycle of transmission of Trypanosoma cruzi from palm trees in the Amazon.

A trophic network involving molds, invertebrates, and vertebrates, ancestrally adapted to the palm tree (Attalaea phalerata) microhabitat, maintains enzootic Trypanosoma cruzi infections in the Amazonian county Paço do Lumiar, state of Maranhão, Brazil. We assessed seropositivity for T. cruzi infections in the human population of the county, searched in palm trees for the triatomines that harbor these infections, and gathered demographic, environmental, and socioeconomic data. Rhodnius pictipes and R. neglectus in palm-tree frond clefts or in houses were infected with T. cruzi (57% and 41%, respectively). Human blood was found in 6.8% of R. pictipes in houses, and 9 of 10 wild Didelphis marsupialis had virulent T. cruzi infections. Increasing human population density, rain forest deforestation, and human predation of local fauna are risk factors for human T. cruzi infections.

Adolescent↗
PubMedDate not supplied

[A study of psychomotor development in premature patients during their first year].

INTRODUCTION: It is necessary to differentiate neurological evaluation in the different stages of development, which include the premature newborn infant (PNI), the full term newborn, the unweaned baby, the child and the teenager. Several studies have shown the importance of using the corrected age when exploring the psychomotor development of premature babies. CASUISTICS AND METHOD: The population we studied was made up of a cohort of PNI who were born in the Hospital de Cl nicas de Porto Alegre and were monitored until they reached the age of 12 months. Motricity, sociability and speech were all considered. RESULTS AND CONCLUSIONS: It was possible to establish the frameworks of neurological development at the corrected ages of 3, 6, 9 and 12 months. The development of static balance was the only item among the motor aspects that did not agree with what was to be expected for the corrected age. The PNIs development was uniform, with regard to the perceptive and language functions for each corrected age. Such results reinforce the importance of studies like the one we present in this paper, since it is a period that can provide us with information that is useful for the early diagnosis of development disorders. It is also the best time to indicate psychomotor and affective stimulation, if we bear in mind the importance of the brain s plasticity during the first year of life.

Child Development↗
PubMedDate not supplied

[Cerebrovascular disease as an initial finding in childhood tuberculosis meningoencephalitis].

INTRODUCTION: The prevalence of tuberculosis in developing countries, such as Brazil, remains high with important morbidity and mortality rates among children. Neurological complications are frequent and tuberculous meningo-encephalitis (TBM) is the most dreaded of them in infancy. CASE REPORT: Our case involves a 7-year-old white female patient who was previously in good health. Over a period of two weeks she suffered from high temperatures and vomiting and was given amoxicillin. She later suffered an attack of focal seizures. Electroencephalogram studies showed a temporary double focus and lesions in the left hemisphere. A cranial computerised tomography (CT) scan revealed a periventricular haemorrhage on the left side. The control CT (carried out 20 days later) showed a reduction in the haemorrhage and localised hypodensity. Owing to the suspected existence of an abscess, the patient was administered vancomycin. A new cranial CT scan (40 days after the first) showed gliosis alongside the basal nuclei with impregnation in the carotid trifurcation, which led us to suspect that we were dealing with a case of vasculitis or a granuloma. All the microbacterial cultures were negative and there was no history of contact with tuberculosis. The adenosine deaminase (ADA) value in the sample of cerebrospinal fluid (taken seven weeks after the first) was found to be 21.2 UI. Treatment was started with tuberculostatic compounds. Two weeks later the fever disappeared. The control CT scan showed decreased hypodensity and impregnation. The patient was discharged from hospital, with a slight monoparesis in the upper right limb. DISCUSSION: The presentation of a cerebrovascular disease within a context of TBM, like the case reported here, is relatively rare in the literature. We concluded that the uncommon initial symptoms of TBM, associated with the negative cultures, contributed to the delay in reaching a diagnosis. A cerebrovascular accident must be included in the clinical picture of TBM and this disease has to be taken into account when dealing with a case of cerebrovascular accident.

Cerebrospinal Fluid↗
PubMedDate not supplied

[Villous adenoma of the Vater's ampulla].

Benign tumors of the ampulla of Vater are rare. The villous adenoma, the most common benign tumor of this region, has a high tendency to malignant transformation. Postmortem studies showed an incidence of 0.04-0.12% adenomatous lesions of the papilla of Vater. The authors present a case of villous adenoma of the ampulla of Vater and make a review of the literature.

Adenoma, Villous↗