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A M Almeida

Publications and source records attributed to A M Almeida.

At least 37 records · Page 2Linked to original sources
PubMed1998

The kinetic profile of vancomycin in neonates.

The pharmacokinetic parameters of vancomycin in a neonatal population have been characterized to enable development of optimum dosage guidelines for neonatal intensive-care units and to examine the relationship between these pharmacokinetic parameters and various demographic, developmental and clinical factors which might be associated with changes in the kinetic profile of vancomycin. Forty-four infants (twenty-five males and nineteen females) with suspected or proven Gram-positive infection and who received intravenous vancomycin between October 1993 and December 1996 were included in this retrospective analysis. Gestational age ranged from 25 to 40 weeks and postconceptional age at the time of the study ranged from 28 to 45 weeks. Sixty case-studies were obtained from the forty-four patients, with one period of study corresponding to one week or one cycle of therapy. Vancomycin pharmacokinetic parameters were determined by use of a one-compartment model. By regression analysis the current weight (g) was shown to be the stronger covariate, and both vancomycin clearance (L h(-1)) and volume of distribution (L) had to be normalized. The vancomycin volume of distribution depended on the postconceptional age with a cut-off at 32 weeks, whereas vancomycin clearance depended on the presence or absence of concomitant treatment with indomethacin or of mechanical ventilation, or both. On the basis of the pharmacokinetic parameters obtained we suggest initial dosage guidelines for vancomycin ranging from 10 mg kg(-1) every 8 h to 10 mg kg(-1) every 12 h, depending on the demographic and clinical characteristics of the patients. The results obtained enabled application of better a priori and a posteriori dosage schedules to infants in neonatal intensive-care units by use of the Bayesian approach, although further prospective study is recommended before direct extrapolation to patients in other settings.

Body Weight↗
PubMed1996

Chemical and pharmacological characterization of halitoxin from Amphimedon viridis (Porifera) from the southeastern Brazilian coast.

The halitoxin complex from the marine sponge Amphimedon viridis, collected in the São Sebastião channel (southeastern Brazilian coast), was isolated by gel-filtration chromatography on Sephadex LH-20. Spectroscopic data (1H, 13C and 2D-NMR) of halitoxin from A. viridis indicated that it has the same two alkylpyridine monomers composition of the previously isolated halitoxin from Amphimedon compressa (as Haliclona rubens). Nevertheless, analysis by High Performance Gel Permeation Chromatography indicated that the halitoxin complex of A. viridis has a lower molecular weight (500, 2000 and 5000 Da; the major component corresponding to the fraction of 2000 Da MW) when compared to the previously isolated halitoxin complex from A. compressa. Some pharmacological properties of the halitoxin complex from A. viridis were evaluated in terms of lethality, antimitosis, hemolysis and neurotoxicity. The possible chemotaxonomic value of alkyl pyridine alkaloids is discussed.

Action Potentials↗
PubMed1996

Clinical-epidemiologic study of alopecia areata.

BACKGROUND: Alopecia areata is a common disease and may be associated with autoimmune disease, atopy, Down syndrome, emotional stress, and foci of sepsis. METHODS: Seven cases of alopecia areata were diagnosed among workers in the Water and Effluent Treatment Sector (WETS) of a paper factory, representing a 0.6% incidence, when the value for the population at large is 0.1%. Three of these workers are assigned to the WETS on a permanent basis and four provide maintenance services. One of the latter patients had alopecia areata that fully regressed. Because biologic treatment of water and effluents involves saprophytic bacteria and fungi as well as chemical substances such as acrylamide, a clinical examination and laboratory tests were performed on all workers assigned permanently to the WETS (N = 9) and on 25% of the workers, selected at random providing services to the sector (N = 14). RESULTS: There was no association between alopecia areata and atopy, dermatophytosis, or bacteria isolated. Toxicologic evaluation revealed an acrylamide-like substance in 7 workers with alopecia areata, with a statistically significant correlation. Measures were taken at the workplace to decrease worker contact with the mists (probably containing acrylamide) in the pulp-pressing room; no other cases of alopecia areata had been detected 1 year after the study. CONCLUSIONS: A survey of the literature did not show reports of alopecia areata as an occupational dermatosis, but our conclusion is, that this dermatosis could be due to the professional activities of the workers at the paper factory studied.

Adult↗
PubMed1994

Oxidative damage of mitochondria induced by Fe(II)citrate is potentiated by Ca2+ and includes lipid peroxidation and alterations in membrane proteins.

Isolated rat liver mitochondria exposed to Fe(II)citrate undergo lipid peroxidation and alterations in membrane proteins. These processes were associated with irreversible decrease in membrane potential and mitochondrial swelling. Lipid peroxidation was evidenced by the production of thiobarbituric acid-reactive substances and also by the reaction of these products with membrane proteins, through the formation of Schiff bases. Alterations in membrane proteins were also characterized by the loss of specific proteins that could be recovered from the mitochondrial supernatant as shown by SDS-polyacrylamide gel electrophoresis. The degree of both lipid peroxidation and alterations in membrane proteins were diminished by EGTA, ruthenium red, or dibucaine. This strongly indicates that Ca2+ potentiates the oxidative damage of mitochondria exposed to Fe(II)citrate.

Animals↗
PubMed1992

Identification of surface-exposed Yersinia pestis proteins by radio-iodination and biotinylation.

When whole cells (stationary phase) of Yersinia pestis strain EV76 were radiolabelled with Iodogen and 131I, 16 major and 10 minor surface-exposed outer membrane proteins (OMPs) were identified. Labelling with N-hydroxysuccinimidyl 6-biotinylamino-hexanoate (biotin X-NHS) resulted in a complex protein profile detectable after blotting and developing with peroxidase-conjugated avidin. Y. pestis cell fractionation revealed that biotin X-NHS labelled not only OMPs but also proteins of inner cell compartments. Therefore, radiolabelling was the more reliable technique for identifying the OMPs of Y. pestis.

Bacterial Outer Membrane Proteins↗
PubMed1991

Surface-exposed antigenic determinants in outer membranes of wild Yersinia pestis isolates.

Immunogenic surface exposed envelope proteins of Yersinia pestis strains were investigated with SDS-PAGE and immunoblots with antisera of immunized guinea pigs and convalescent patients. The sarkosyl-insoluble outer membrane proteins (OMPs) of three human isolates and one laboratory strain of Y. pestis grown in different rich media to exponential or stationary phase, and cultivated at 28 degrees C or 37 degrees C, were assayed for the presence of immunogenic peptides. Seven guinea-pig sera immunized with one of the four Y. pestis strains and four human sera from plague-infected patients indicated that at least four outer membrane proteins with molecular weights of 45 KDal, 42 KDal, 21 KDal and 16.5 KDal were strongly recognized by at least one of them. All but one of the guinea-pig serum and one human serum recognized the 45 KDal protein. The 42 KDal was identified only in outer membrane isolated from Y. pestis cells grown at 28 degrees C. All immunogenic OMPs were found in the four strains investigated. Labelling of intact Y. pestis cells with Iodogen and 131I further demonstrated the surface-exposed location of the immunogenic OMPs.

Animals↗
PubMed1990

Interaction of lectins with Yersinia pestis strains.

The ability of lectins to interact with Yersinia pestis strains isolated from rodent fleas and human biological fluids, obtained from different geographic areas, was examined. Lectins of Canavalia ensiformis, Ulex europaeus, Phaseolus vulgaris, and Triticum vulgaris, as well as a new autochthonous lectin of Swartzia pickellii of undefined specificity, were used. Most of the Y. pestis strains did not agglutinate with U. europaeus or C. ensiformis lectin. However, P. vulgaris lectin agglutinated suspensions of all the bacillus strains used. Fifteen of the 19 strains tested positive for assays using S. pickellii lectin. It is believed this is the first report of Y. pestis strain agglutination by lectins. A similar agglutination pattern was obtained for lectins with specificity for oligosaccharides containing N-acetylglucosamine and S. pickellii lectin, which did bind to the affinity matrix chitin, a polysaccharide of N-acetylglucosamine. The use of bacterial strains and commercial lectins of defined specificity may be an approach to providing evidence about the lectin binding sites of undefined monosaccharide specificity.

Agglutination↗
PubMed1990

Immunochemical localization of the fraction-1 antigen, a virulence determinant of Yersinia pestis.

The distribution of Yersinia pestis Fraction-1 (F1) antigen was analyzed in cells grown at 28 degrees C and 37 degrees C. Fractionation of Y. pestis cells followed by analysis in SDS-polyacrylamide gel electrophoresis indicated that the mature form of the F1 antigen is localized in the extracellular matrix and in the cytoplasm. Localization of the F1 antigen was confirmed by immunoblots and a single peptide with a molecular weight of 17,000 daltons was recognized. Electron microscopy of Y. pestis cells labeled with colloidal gold-conjugated antibodies corroborated the extracellular matrix and cytoplasm dual location of the F1 antigen.

Antigens, Bacterial↗
PubMed1989

Electrophoretic characterisation of the outer membrane proteins of Yersinia pestis isolated in north-east Brazil.

The outer membrane proteins of 38 Yersinia pestis isolates from all known plague foci of north-east Brazil were analysed by SDS-PAGE. Approximately 20 bands were consistently found in all strains analysed and 11 were selected for comparative studies. Although qualitative differences among the electrophoretic profiles of outer membrane proteins of wild Y. pestis isolates were not observed, quantitative alterations were clearly noted for most of these proteins. No particular quantitative alteration of the electrophoretic profile of outer membrane proteins could be associated with the period of isolation and geographic origin of the isolates. The 64 kDa outer membrane protein was significantly expressed in higher amounts among Y. pestis strains isolated from a recent plague outbreak. The possible use of electrophoretic profiles of outer membrane proteins of wild Y. pestis isolates as a tool for epidemiological studies and for the analysis of virulence determinants is discussed.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

Diagnosis of plague and identification of virulence markers in Yersinia pestis by multiplex-PCR.

We have developed a procedure for the rapid diagnosis of plague that also allows the identification of prominent virulence markers of Y. pestis strains. This procedure is based upon the use of a single polymerase chain reaction with multiple pairs of primers directed at genes present in the three virulence plasmids as well as in the chromosomal pathogenicity island of the bacterium. The technique allowed the discrimination of strains which lacked one or more of the known pathogenic loci, using as template total DNA obtained from bacterial cultures and from simulated blood cultures containing diluted concentration of bacteria. It also proved effective in confirming the disease in a blood culture from a plague suspected patient. As the results are obtained in a few hours this technique will be useful in the methodology of the Plague Control Program.

Biomarkers↗
PubMedDate not supplied

[Isolation of pathogenic bacteria in pasteurized type C milk sold in Recife City, Pernambuco, Brazil].

In order to improve information about the microbiological quality of the milk commercially available in the city of Recife, 250 samples of pasteurized type-C milk and 50 samples of raw milk were analyzed for Yersinia enterocolitica and Listeria monocytogenes and verify the possible occurrence of Yersinia enterocolitica and Listeria monocytogenes. These bacteria can develop in refrigeration temperatures and are responsible for food-born diseases. Neither Y. enterocolitica nor L. monocytogenes were found in the samples analyzed. However, the presence of Y. intermedia and Y. frederiksenii was detected, these environmental species behave as opportunist pathogens. Through the methodology used for Listeria isolation, one isolate of Salmonella Montevideo was obtained from a sample of pasteurized milk and another isolated from one sample of raw milk. Besides these, several other bacteria species were found. It is likely that the large microbiota present in the samples and the procedures employed to destroy it could have hindered the isolation of Y. enterocolitica and L. monocytogenes.

Animals↗
PubMedDate not supplied

Cellulose acetate as solid phase in ELISA for plague.

Antigen from Yersinia pestis was adsorbed on cellulose acetate discs (0.5 cm of diameter) which were obtained from dialysis membrane by using a paper punch. ELISA for human plague diagnosis was carried out employing this matrix and was capable to detect amount of 1.3 microg of antigen, 3,200 times diluted positive serum using human anti-IgG conjugate diluted 1:4,000. No relevant antigen lixiviation from the cellulose acetate was observed even after washing the discs 15 times. The discs were impregnated by the coloured products from the ELISA development allowing its use in dot-ELISA. Furthermore, cellulose acetate showed a better performance than the conventional PVC plates.

Antigens, Bacterial↗
PubMedDate not supplied

[Spiritual surgery: an investigation].

BACKGROUND: A very popular modality with the media is psychic surgery which has received little scientific evaluation though. Such phenomena always raise the issues of fakery and deceit. Research has been scarce. METHODS: We report an investigation on one of the most famous psychic surgeons in Brazil, João Teixeira de Farias. 30 surgical interventions with cutting were studied, 6 patients undergoing history-taking, physical examination and analysis of the materials supposedly extracted from them. RESULTS: We were struck by the fact that the surgeon really incisions skin or ocular epithelium in addition to scraping the cornea without identified anaesthetics or antiseptics being used. Just one woman complained of pain as she had her breast incised. Longer follow up of patients failed to notice any infection in the surgical sites. Histopathology found the specimens to be compatible with their site of origin and, apart from a 210g. lipoma, were healthy tissues without discernible pathology. CONCLUSIONS: The surgerical procedures are real but we couldn't evaluate the efficacy. It didn't appear to have any specific effect. Our findings are undoubtedly more of an exploratory kind than conclusive ones. Further studies are clearly necessary to cast light on this unorthodox treatment.

Adult↗
PubMedDate not supplied

[Aids neurologic manifestations in childhood].

INTRODUCTION: Children with AIDS get infected mainly by vertical transmission. DEVELOPMENT: That was what happened in 90% of the cases in a series of 340 HIV+ children followed at Hospital de Clínicas de Porto Alegre, Brazil. Currently, after the use of prophylactic treatment during pregnancy and the six first weeks of life, our transmission rate is 3% to 4%. The incidence of neurologic complications in the vertical transmission group was 49% in our prospective series, and due either to immunosuppression or primary neurological disease. Neurologic changes secondary to HIV constitute a complex syndrome, manifested by various degrees of cognitive, motor and behavioral delay. Encephalopathy can be either progressive or static. In our series, encephalopathy occurred in 32.5% of cases, developmental delay in 42.5%, seizures in 6%, speech delay in 5%, headaches in 2.5% and behavioral disorders in 2%. Central nervous system infections happened in 33.8% of our cases: acute bacterial infections in 11%, cytomegalovirus in 6.8%, toxoplasmosis in 5.9%, cryptococcal in 5%, tuberculous in 3.8% and syphilis in 1.3%. Hemorrhagic cerebrovascular accidents were seen in 2.5% of our cases, and peripheral neuropathy in 5%. Seventy percent of our cases had abnormalities in the CSF, 75% in brain CT scans and 45% in EEGs. CONCLUSIONS: Treatment of children with AIDS and neurologic manifestations was based on specific drugs aimed at controlling viral replication. Best response was obtained with combined use of AZT and other anti-retroviral neuro-protective.

AIDS Dementia Complex↗