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C Pedrosa

Publications and source records attributed to C Pedrosa.

14 recordsLinked to original sources
PubMed2005

Anaphylaxis to povidone in a child.

Povidone is an allergic agent present in numerous substances, food and medicines. The authors present the clinical case of a 9-yr-old male child admitted in the emergency room with anaphylaxis, in two occasions separated by a 6-month period. The first episode occurred 5 min after the first oral administration of Fluvermal (flubendazole) and the second occurred 10 min after cutaneous application of Betadine (povidone iodine solution). Previous cutaneous application of this solution and ingestion of mebendazole occurred without apparent adverse reactions. The allergy study revealed eosinophilia, an elevated total IgE level and positive prick-by-prick test for both drugs. A cutaneous prick-by-prick test with povidone (the sole common constituent) was also positive. This is probably the first case described in the literature of anaphylaxis induced by povidone in a child.

Anaphylaxis↗
PubMed2001

[Mechanisms underlying endothelin-1 effects on myocardial function].

INTRODUCTION: Endothelin-1 (ET-1) has potent vasoconstrictor, growth promoting and positive inotropic properties. Its effects on the intrinsic properties of the myocardium were recently described. The present study investigated the mechanisms underlying those effects. METHODS: The myocardial effects of 1 and 10 nM of ET-1 were evaluated in isolated rabbit papillary muscles (n = 9) and human atrial trabecula from CABG patients (Krebs-Ringer; 1.8 mM CaCl2; 35 degrees C). In papillary muscles the effects of 1 nM ET-1 were also studied in the presence of: (i) a selective ETA receptor antagonist, BQ-123 (0.1 microM; n = 9); (ii) a selective ETB receptor antagonist, BQ-788 (0.1 microM; n = 6); and (iii) an Na+/H+ exchanger inhibitor, methyl-isobutyl-amiloride (MIA; 1 microM; n = 6). Only significant results (mean +/- SE, p < 0.05) are given, expressed as delta % baseline. RESULTS: In AT by papillary muscles, 1 nM of ET-1 increased 64 +/- 16%, dT/dtmin 39 +/- 13% and decreased PT by 11 +/- 2%. The analysis of atrial strip contractions yielded similar results. In papillary muscles the effects of ET-1 were not affected by BQ-788, yet they were abolished by BQ-123, and reduced by 44% by MIA. CONCLUSIONS: The action of ET-1 on myocardial function is similar in human and non-human myocardium. The myocardial effects observed in the present study are mediated by the binding to ETA receptors, and partially dependent on Na+/H+ exchanger activation.

Animals↗
PubMed2000

Selective neoglycosylation increases the structural stability of vicilin, the 7S storage globulin from pea seeds.

The effects of glycosylation on the stability and subunit interactions of vicilin, the major storage protein in pea seeds, were investigated. Glycosylated vicilin derivatives were prepared by alkylation of lysine epsilon-amino groups with various carbohydrates. Average modification levels of 13.4 +/- 3.0, 11.1 +/- 3.6, 7.5 +/- 4.2, and 4.7 +/- 0.3 moles of carbohydrate/mol of vicilin were obtained with glucose, galactose, galacturonic acid, and lactose, respectively. Nondenaturing polyacrylamide gel electrophoresis and size-exclusion chromatography indicated that the quaternary structure and hydrodynamic radius of vicilin were not affected by glycosylation at the levels used. We have previously shown that application of hydrostatic pressure causes dissociation of vicilin subunits [C. Pedrosa and S. T. Ferreira (1994) Biochemistry 33, 4046-4055]. Analysis of pressure dissociation data allowed determination of the Gibbs free energy change (deltaG(diss)) and molar volume change (deltaV(diss)) of dissociation of vicilin subunits. For unmodified vicilin, deltaG(diss) = 18.2 kcal/mol and deltaV(diss) = -102 ml/mol. Glycosylated vicilin derivatives were significantly stabilized against subunit dissociation, with deltaG(diss) of 19.4, 19.2, 20.6, and 22.1 kcal/mol for glucose, galactose, lactose, and galacturonic acid derivatives, respectively. No changes in deltaV(diss) were found for the glucose and galactose derivatives, whereas deltaV(diss) of -128 and -135 ml/mol, respectively, were found for the lactose and galacturonic acid derivatives. The glycosylated derivatives also appeared more resistant to unfolding by guanidine hydrochloride than unmodified vicilin. Intrinsic fluorescence lifetime measurements showed that glycosylation caused a significant increase in heterogeneity of the fluorescence decay, possibly reflecting increased conformational heterogeneity of glycosylated derivatives relative to unmodified vicilin. These results indicate that the stability and subunit interactions of vicilin may be modulated by mild, selective glycosylation at low modification levels, an effect that may be of interest in the study of other oligomeric proteins.

Chromatography, Liquid↗
PubMed1999

Adult T-cell leukemia/lymphoma in northeastern Brazil: a clinical, histopathologic, and molecular study.

The state of Bahia in the northeastern coast of Brazil is a region in which HTLV-I infection is endemic. This study investigated the characteristics of 28 HTLV-I-associated lymphomas/leukemias in this region. HTLV-I-infection diagnosis was based on serologic study, Southern blot analysis, and polymerase chain reaction (PCR) in neoplastic tissue. The main clinical differences between these lymphomas and adult T-cell leukemia (ATL) cases from other endemic areas were as follows. The mean age was 47 years; 20% of the cases occurred in young adults; and a predominance was found among male subjects (2:1), blacks, and of those of mixed race (96%). Histologically, 20 cases were T-cell pleomorphic leukemia/lymphoma, 5 were Mycosis fungoides-like cutaneous lymphoma, and 3 were CD30+ large-cell anaplastic lymphoma. Immunohistochemistry demonstrated 4 cases of CD8+ lymphoma. Proviral genomic sequences were demonstrated by PCR in 9 lymph node biopsy specimens and in 3 skin biopsy specimens. Southern blot was performed and was positive in 8 cases.

Adolescent↗
PubMed1997

Co-Infection of Tuberculosis and HIV/HTLV Retroviruses: Frequency and Prognosis Among Patients Admitted in a Brazilian Hospital.

During 2 1/2 year period,378 patients diagnosed with tuberculosis and admitted to a general hospital for care of the poor in Salvador, Bahia, were tested serologically for HIV-1, HTLV-I, and HTLV-II. The patients' mean age was 41.8 (range 14-89); they were hospitalized for a mean of 62 +/- 43 days; 70% were being treated for the first time; most of the remainder were being retreated after non-compliance with previously recommended anti-tuberculosis medication and a few required second-line therapy for relapsed disease. None had had previous serologic testing for retroviruses. Among the study population, 59 (16%) were found to be positive for retroviral infection. The distribution was as follows: 18 (4.8%) had HIV-1, 32 (8.5%) had HTLV-I, 2 of these had both HTLV-l and HTLV-II, 9 (2.4%) had both HIV-1 and HTLV-I. The rates of positive serologic tests for retroviral infection in this Salvador is 0.2% for HIV-1 and 1.0% for HTLV-I. Thus, there is a higher than expected frequency of retroviral infections among patients hospitalized for treatment of tuberculosis. The prognosis for treated patients was determined by recording the cause of death and the mortality rate. In the 319 patients with negative serologic testing for retroviruses there were 25 deaths (8%). In 32 patients with HTLV-I infection there were 8 deaths (25%), and in 18 patients with HIV-1 infection there were 6 deaths (33%). In 9 patients with both HIV-1 and HTLV-I there were 5 deaths (56%). The causes of death in each serological group were primarily related to progression of tuberculosis rather than complications of rapid progression of the retroviral infection. We conclude that co-infection and disease due to either HIV-1 or HTLV-I/II infection and tuberculosis is common, that the occurrence of HTLV-I in this population is higher than previously recognized, and that prognosis associated with the management of tuberculosis is adversely affected by the presence of either retroviral infection. In a few patients with both retroviral infections, mortality was very high. All patients with tuberculosis should be tested for retroviral infection because of the prognostic and therapeutic implications.

Journal Article↗
PubMed1994

Deterministic pressure-induced dissociation of vicilin, the 7S storage globulin from pea seeds: effects of pH and cosolvents on oligomer stability.

A thermodynamic characterization of subunit association of vicilin, a storage protein from pea seeds, was performed using a combination of hydrostatic pressure and fluorescence spectroscopy. Application of pressure up to 2.4 kbar caused dissociation of vicilin subunits, as revealed by (1) size-exclusion PPLC of pressurized samples, (2) fluorescence anisotropy measurements of a dansyl-vicilin conjugate under pressure, and (3) quenching of the intrinsic fluorescence of vicilin. Pressure dissociation data were well described by a model for dissociation of a trimer. This enabled calculation of the standard molar volume change of association (delta Vo) and the equilibrium dissociation constant at atmospheric pressure (Ko); at pH 10 these were found to be delta Vo = 146 mL/mol and Ko = 2.2 x 10(-15) M2, respectively, corresponding to C1/2 (the concentration of protein at 50% dissociation at atmospheric pressure) = 18 nM and a stabilization free energy of -19.6 kcal/mol for the oligomer. Vicilin exhibited an anomalously low dependence on protein concentration for pressure dissociation. This appeared related to conformational changes in the dissociated subunits, which caused a loss of ca. 5 kcal/mol in the free energy of association and to structural/energetic heterogeneity in the population of oligomers. Pressure dissociation was markedly pH-dependent, with a stabilization free energy loss of 3.4 kcal/mol upon raising pH from 9 to 10. Circular dichroism and intrinsic fluorescence lifetime measurements at atmospheric pressure showed that the structure of vicilin was largely unaffected by pH in the range investigated. These results suggest that the effect of pH may involve deprotonation of lysine residues participating in salt bridges between vicilin subunits. Pressure dissociation of vicilin was significantly inhibited by addition of salts (NaCl, KCl, LiCl) or glycerol. Dissociation curves obtained in the presence of salts enabled calculation of the free energies of stabilization (ranging from ca. -1.2 to -2.4 kcal/mol) of the vicilin oligomers by these cosolvents. The similar effects of salts or glycerol suggest a common mechanism of stabilization of the oligomer involving exclusion of the cosolvents from the protein interface and preferential hydration of the protein.

Fabaceae↗
PubMed1993

Extensive heterogeneity of proteoglycans bearing fucose-branched chondroitin sulfate extracted from the connective tissue of sea cucumber.

The major sulfated polysaccharide in the sea cucumber body wall is a fucose-branched chondroitin sulfate. This glycosaminoglycan has side-chain disaccharide units of sulfated fucopyranosyl or sulfate esters linked to the O-3 position of the beta-D-glucuronic acid residues. These unusual fucose branches and sulfate esters block the access of chondroitinases to the chondroitin sulfate core [Vieira & Mourão (1988) J. Biol. Chem. 263, 18176-18183; Vieira et al. (1991) J. Biol. Chem. 266, 13530-13536]. We now report the isolation and preliminary characterization of the proteoglycans bearing this unique fucose-branched chondroitin sulfate. They were extracted using guanidine hydrochloride solutions containing protease inhibitors and were purified by anion-exchange and gel-filtration columns. Interestingly, the sea cucumber proteoglycans were cleaved by chondroitinase AC or ABC, indicating that the beta-D-glucuronic acid residues close to the reducing end of the polysaccharide chain are neither fucosylated nor sulfated. SDS-polyacrylamide gel electrophoresis revealed several fractions of proteoglycans of different molecular sizes but containing a similar hexuronic acid/protein ratio and a similar type of glycan chain. Possibly, the low-molecular-size fractions arise from a protease cleavage of a larger molecule. In contrast with the results observed for most vertebrate proteoglycans, which contain a single core protein for each type of proteoglycan, chondroitinase AC or ABC releases from the sea cucumber proteoglycans a wide variety of core proteins. These observations are the first detailed study of a proteoglycan from invertebrate tissue and reveal extensive heterogeneity when compared with proteoglycans from vertebrate connective tissue.

Animals↗
PubMed1993

Immunochemotherapy of visceral leishmaniasis: a pilot trial of sequential treatment with recombinant interferon-gamma and pentavalent antimony.

The clinical, parasitological, hematological, and serological evolution of visceral leishmaniasis in Brazilian patients was assessed during treatment with human recombinant interferon-gamma (rIFN-gamma; 0.1 mg/m2 i.m. days 1-14) followed by pentavalent antimony (Sbv; 10 mg/kg days 22-28). At day 30, 6 patients had improved, 2 had slightly improved, and 1 patient had deteriorated. IFN-gamma was well tolerated in the dose tested and may be very effective as an adjunct to conventional therapy with antimony.

Adolescent↗
PubMed1991

Generation of cytokines in human visceral leishmaniasis: dissociation of endogenous TNF-alpha and IL-1 beta production.

The role of TNF-alpha in visceral leishmaniasis is ambivalent, the eventual outcome of this infection, cure or generalization, being determined by the relative amounts of cytokines produced in vivo. Since release, by monocytes/macrophages, of TNF-alpha and interleukins 1 beta (IL-1 beta) and IL-6 is important in both the induction and effector phases of the immune responses, these mediators were determined in sera and cell culture supernatants of seventeen L. donovani infected patients in Brazil. The results are compared to those of a local control group. Circulating immunoreactive TNF-alpha in patients (median, 140 pg ml-1) was increased ten-fold over controls (median 16 pg ml-1, p less than or equal to 0.0001). In contrast, serum IL-1 beta was less than 20 pg ml-1 in all patients, although detectable in sera of 3/16 Brazilian controls (chi 2 = 3.5, p less than 0.1). Mitogen induced in vitro release of IL-1 beta and IL-6 by patients' circulating mononuclear cells was significantly reduced, and the capacity of patients' peripheral monocytes for H2O2 generation in response to opsonized zymosan was significantly diminished. In the patients, serum TNF-alpha levels were inversely related to IL-1 beta release in vitro (rho = -0.57, p less than or equal to 0.01).

Adolescent↗
PubMed1990

Determinants of the immune response in visceral leishmaniasis: evidence for predominance of endogenous interleukin 4 over interferon-gamma production.

Accumulating evidence points toward an antagonism between TH1 and TH2 focused immune responses decisive for the outcome of parasitic infections with leishmaniae. Interferon-gamma (IFN-gamma) and interleukin 4 (IL4), the principal cytokines involved in these pathways, as well as IgE and the IgG subclasses differentially modulated by these cytokines, were therefore assessed in 18 Brazilian patients with visceral leishmaniasis. The results are compared to those of a local control group. IL4 was detected in all patient sera but in only one control. Low concentrations of IFN-gamma where detectable in 50% of the Brazilian controls but in only two patients. While group medians of mitogen-induced in vitro synthesis of IL4 and IFN-gamma were similar, release of these lymphokines correlated inversely in patients (Spearman's rho = -0.84). Elevations of serum IgE complement the lymphokine data to indicate prominent TH2 type responses in clinical infections with Leishmania donovani.

Adolescent↗
PubMed1983

Anatomy of the upper abdomen: computarized tomography.

The possibilities of computed axial tomography in displaying normal anatomy are shown. The fact scanners are able to show important anatomical details including vascular anatomy. The upper abdomen is shown in consecutive slices to demonstrate the most important anatomical landmarks. The possibility of reconstructed coronal and sagittal planes from the axial slices offers good correlation with classical topographical anatomy. Axial anatomy from cadaver and computed tomography should be included in our teaching to medical students as part of the background needed for their future clinical practice.

Abdomen↗
PubMed1979

Improved visualization of radiographic cadaver sections using xerotomography.

A new technique using xerotomography for axial images obtained from slices of abdominal cadavers is described. Radiographs were also made in sagittal planes for a complete study of visceral relationships. Xerotomography allows a wider range of visualization in the same plane of anatomical structures, from retroperitoneal fascial planes and vessels to abdominal viscera.

Cadaver↗