Morphometry of submucous and myenteric esophagic plexus of dogs experimentally reinfected with Trypanosoma cruzi.

We carried out a morphometric study of the esophagus of cross-bred dogs experimentally infected or consecutively reinfected with Trypanosoma cruzi 147 and SC-1 strains, in order to verify denervation and/or neuronal hypertrophy in the intramural plexus. The animals were sacrificed in the chronic stage, 38 months after the initial infection. Neither nests of amastigotes, nor myositis or ganglionitis, were observed in all third inferior portions of esophageal rings analyzed.

Neuron count reevaluation in the myenteric plexus of chagasic megacolon after morphometric neuron analysis.

This study was made with the objective of reevaluating the colon denervation in chronic Chagas' disease. The diameters of neuron perikaryons of the myenteric plexus were measured on paraffin sections in a ring from the sigmoid in Chagas' disease patients, 17 with and 10 without megacolon and in 10 non-chagasic controls. All neurons were counted in ten en-echelon sections.

Gold complexes with dithiothiophene ligands: a metal based on a neutral molecule.

The gold complexes n-Bu4N[Au(alpha-tpdt)2] (5), n-Bu4N[Au(dtpdt)2] (4) and n-Bu4N[Au(tpdt)2] (6) based on new dithiothiophene ligands (alpha-tpdt= 2,3-thiophenedithiolate, dtpdt=2,3-dihydro-5,6-thiophenedithiolate and tpdt = 3,4-thiophenedithiolate) have been prepared and characterised. These gold(III) complexes are diamagnetic, but they can be oxidised with iodine to the paramagnetic compounds [Au(alpha-tpdt)2] (8), [Au(dtpdt)2] (7) and n-Bu4N[[Au(tpdt)2]n-2] (9), which were isolated as fine powders and which exhibit paramagnetic susceptibilities that are almost temperature independent with room temperature values of 2.5 x 10(-4), 2.

Induction of apoptosis in murine lymphoma cells by cyclosporin A.

The aim of this study was to investigate if CsA could induce apoptosis in the murine T-lymphoma cell line LBC, whose growth is inhibited by this immunosuppressive drug. CsA induced programmed cell death in LBC cells with typical features of apoptosis demonstrated by exposure of phosphatidyl serine residues on the cell membrane, the decrease of cell DNA content, chromatin condensation, and nuclear fragmentation. Apoptosis was evident within 12 h after CsA incubation, with a maximal effect at 48 h, in a time and dose-dependent fashion.

Modulator activity of PSC 833 and cyclosporin-A in vincristine and doxorubicin-selected multidrug resistant murine leukemic cells.

Multidrug resistance (MDR) lines from a murine T-cell leukemia were selected in increasing vincristine (VCR) or doxorubicin (DOX) concentrations. Daunorubicin (DNR) efflux was evidenced after 25 additional passages with constant 160 ng ml(-1) of either VCR or DOX, an effect that was inhibited by verapamil, cyclosporin-A (CsA) and PSC 833. The expression of Pgp was not evidenced in the resistant cell lines using anti-human Pgp antibodies.

[The pampiniform plexus in the chronic phase of human Chagas disease: histologic assessment].

The occurrence of Trypanosoma cruzi intracellular clusters and phlebitis was searched for on pampiniform plexus vein walls of chronic chagasic patients. For this purpose, 23 pairs of spermatic cords, epididymides and testes (17 from chagasic patients and 6 from non-chagasic controls) were obtained, at autopsy. Trypanosoma cruzi was investigated by immuno-histochemistry on slides obtained from several sections of the gonads and vessels of each case.

A prospective and randomized study using ribavirin as monotherapy for the treatment of naïve patients with chronic hepatitis C.

In order to evaluate the response to ribavirin in previously untreated patients with chronic hepatitic C, 39 patients were selected for a double-blind prospective and randomized trial, and divided into two groups: ribavirin-group (19 patients) and placebo-group (20 patients). Ribavirin was administered orally for 24 weeks (600 mg/day, followed by 1,000 mg/day and 1,200 mg/day each one for 8 weeks). After 3 months of drug administration, the patients were evaluated by measuring biochemical, virologic and histologic responses.

Evaluation of an enzyme immunoassay for hepatitis C virus antibody detection using a recombinant protein derived from the core region of hepatitis C virus genome.

This study was undertaken to evaluate an enzyme immunoassay (EIA) for hepatitis C virus antibody detection (anti-HCV), using just one antigen. Anti-HCV EIA was designed to detect anti-HCV IgG using on the solid-phase a recombinant C22 antigen localized at the N-terminal end of the core region of HCV genome, produced by BioMérieux. The serum samples diluted in phosphate buffer saline were added to wells coated with the C22, and incubated.

Polymeric colloidal systems containing ethionamide: preparation and physico-chemical characterization.

The association of ethionamide with different colloidal systems was evaluated. Nanocapsules (NC), nanospheres (NS), and nanoemulsions (NE) were prepared by interfacial deposition and spontaneous emulsification techniques. Ethionamide was incorporated before (B) and after (A) preparation of nanoparticles.

Stimulus segmentation in the visual search task.

Four experiments were conducted in order to study the segmentation process in a visual search task with relevant stimuli (target and distractors) randomly distributed among textural elements. The basic idea was that a parallel segmentation process of the relevant stimuli would contribute to the overall reaction time independently of the contribution of the number of relevant stimuli. In the first experiment, with relevant stimuli and textural elements that differed in the orientation of their component lines, texture presence interacted with number of relevant stimuli and with target presence.

[Taste preference for sweets and caries prevalence in preschool children].

Objective: To assess the preference for sweetness among preschool children and differences between less and more deprived groups. In addition, to assess whether sweet taste preference was associated with presence of caries.

Methods: The sample was composed by 572 preschool children aged between 4 and 6, distributed in three day nurseries of varied socioeconomic background.

Potential definition of the time of death from autolytic myocardial cells: a morphometric study.

Morphometric methods and transmission electron microscopy were used to quantify modifications occurring in the mitochondria of dog myocardium during the first four hours of autolysis. Myocardial fragments were obtained from the outer free wall of the left ventricle, during anesthesia (control-zero) and at 15, 45, 120, and 240 min after cardiac arrest, maintaining the heart "in situ" at 22 degrees C. During the 240 min of autolysis, the main parameters evaluated showed: (a) a decrease in the number of mitochondria from 0.

Imaging Trypanosoma cruzi within tissues from chagasic patients using confocal microscopy with monoclonal antibodies.

Confocal fluorescence microscopy combined with differential interference contrast imaging of tissues from chagasic patients enabled the unequivocal identification of the parasite Trypanosoma cruzi. Using different monoclonal antibodies that indicate the parasite form and replication stage in conjunction with DNA labelling, specimens derived from distinct clinical forms of the disease were examined. Intracellular amastigote forms of the parasite were clearly detected in heart, brain, skin, lung, and kidney.

The rat prostatic epithelial cell line NRP-152 can differentiate in vivo in response to its stromal environment.

Background: The clonally derived rat prostatic epithelial cell line NRP-152 was examined to determine its ability to differentiate in a tissue recombination model.

Methods: NRP-152 cells alone, or combined with urogenital mesenchyme (UGM) or 10T1/2 fibroblasts, were grafted beneath the renal capsule of athymic rodent hosts. After 1 and 3 months, grafts were examined grossly and immunohistochemically.

Larva migrans within scalp sebaceous gland.

A case of larva migrans or serpiginous linear dermatitis on the scalp of a teenager is reported. An ancylostomid larva was found within a sebaceous gland acinus. The unusual skin site for larva migrans as well as the penetration through the sebaceous gland are highlighted.

[Glomerulonephritis associated with hepatitis c virus infection].

We report 4 patients with glomerulonephritis (GN) associated with hepatitis C virus (HCV) infection seen between August 1993 and July 1996. Two of them were male and median age was 41 years. Anti-HCV was detected by enzyme-immunoassay and HCV-RNA by PCR.

Distribution of hyaluronan and dermatan/chondroitin sulfate proteoglycans in human aortic dissection.

Aortic dissections (AD) are characterized by the separation of the artery into two sheets, possibly due to fragility of the vessel wall. A mucoid histological pattern, imparted to the tissues mainly by hyaluronan and proteoglycans, can be seen in "cysts" and, in chronic cases, in a band of repair tissue. We studied the localization of hyaluronan, versican, decorin and biglycan in situ in aortas of 21 patients with recent AD, 8 with chronic AD and in 15 control cases.

Prevalence of hepatitis C virus antibodies in primary glomerulonephritis in Brazil.

The association between hepatitis B virus and membranous glomerulonephritis and membranoproliferative glomerulonephritis (MPGN) was first described in 1971. Recently, a similar association between hepatitis C virus (HCV) and glomerulonephritis (GN) has been reported. We investigated the prevalence of hepatitis C serum antibodies (anti-HCV) in patients with primary GN followed up at our Nephrology Outpatient Clinic between March 1993 and November 1995.

Chagasic meningoencephalitis in the immunodeficient.

Based on their own experience and on the literature, the authors compare the brain pathology due to HIV+ associated Trypanosoma cruzi reactivated infection to that described for the natural history of the Chagas' disease (CD). The peculiar focal necrotizing chagasic meningoencephalitis (MECNF) which appears only in immunedeficient chagasics, especially when the deficiency is due HIV is a safe criterion for reactivation of CD. MECNF morphologic findings are unlike to those found either for some cases of acute phase CD or for chronic nervous form of CD.

[Toxoplasmic and chagasic meningoencephalitis in patients with human immunodeficiency virus infection: anatomopathologic and tomographic differential diagnosis].

Twenty-two HIV+ patients with encephalitis were studied. Of these, 7 had meningoencephalitis due to Toxoplasma gondii (MT) and 15 due to Trypanosoma cruzi (MC). Pathologic and computerized axial tomography (CAT) changes were compared.

[Pancreatic neuronal loss in chronic Chagas' disease patients].

We have not found any anatomical studies about the intrapancreatic ganglia in the chronic Chagas' disease. The lesions in these structures could explain at least in part the functional disturbances in the exocrine and endocrine pancreas described in this form of the disease. Thus we decided to morphologically analyze these ganglia.

Distribution of tonin- and kallikrein-like activities in rat brain.

Tonin- and kallikrein-like activities were investigated in different regions of the rat brain. The highest values of specific tonin activity, expressed as picomoles of angiotensin II liberated per minute per milligram of protein, were found in the neurohypophysis (359 +/- 190) and in the archicerebellum (200 +/- 68). The highest level of total tonin activity (picomoles of angiotensin II liberated per minute) was observed in the archicerebellum (902 +/- 308) which retained 97% of total tonin activity of whole cerebellum.