Biomedical subjects

I Gomes

Publications and source records attributed to I Gomes.

At least 55 records · Page 3Linked to original sources

PubMed1996

[Clinical and laboratory characteristics of bacterial meningitis in children].

Data from the records of 528 children under 15 years old with diagnosis of acute bacterial meningitis, admitted at the Hospital Couto Maia between 1990 and 1992 were analyzed. Bacterial meningitis was more frequent in children under the age of 1 year (37.8%). The most common etiologic agent was H. influenzae (42.2%). The global lethality was 20.9%. Individual predictors of poor outcome were: absence of the "classic triad", CSF cell count under 1000/mm3, age under 2 years, presence of seizures, depressed sensorium, and S. pneumoniae as causal agent.

Adolescent↗

PubMed1996

Detection of foot-and-mouth disease viral sequences in various fluids and tissues during persistence of the virus in cattle.

OBJECTIVE: To assess whether foot-and-mouth disease virus (FMDV)-specific sequences could be identified in tissues from persistently virus-infected animals. DESIGN: Cattle with experimentally induced persistent FMDV infections were slaughtered at 750 days after viral exposure. Experimentally infected pigs were slaughtered at 28 days after FMDV inoculation. Postmortem specimens were asceptically removed. ANIMALS: Three bovids and 3 pigs were studied, as well as 1 control animal for each species. PROCEDURE: Various tissues were examined for the presence of FMDV-specific sequences by dot-blot hybridization assay, using a molecularly cloned FMDV cDNA corresponding to the polymerase coding region. RESULTS: The FMDV-specific genomic sequences were only detected in RNA from spleen, lung, larynx, tonsils, pancreas, liver, esophagus, and WBC of bovids. CONCLUSIONS: It was established that, at late stages of the persistent infection, when virus isolation was not possible, cattle may carry FMDV-specific sequences in different tissues. Retention of viral sequences could not be demonstrated in specimens from experimentally infected swine, 28 days after viral inoculation.

Animals↗

PubMed1995

Histamine antagonizes serotonin and growth factor-induced mitogen-activated protein kinase activation in bovine tracheal smooth muscle cells.

We examined the effects of the bronchoconstrictor agonists serotonin (5-hydroxytryptamine; 5-HT) and histamine on mitogen-activated protein (MAP) kinase activation in cultured bovine tracheal myocytes. Kinase renaturation assays demonstrated activation of the 42- and 44-kDa MAP kinases within 2 min of 5-HT exposure. MAP kinase activation was mimicked by alpha-methyl-5-HT and reduced by pretreatment with either phorbol 12,13-dibutyrate or forskolin, suggesting activation of the 5-HT2 receptor, protein kinase C, and Raf-1, respectively. Raf-1 activation was confirmed by measurement of Raf-1 activity, and the requirement of Raf-1 for 5-HT-induced MAP kinase activation was demonstrated by transient transfection of cells with a dominant-negative allele of Raf-1. Histamine pretreatment significantly inhibited 5-HT and insulin-derived growth factor-1-induced MAP kinase activation. Attenuation of MAP kinase activation was reversed by cimetidine, mimicked by forskolin, and accompanied by cAMP accumulation and inhibition of Raf-1, suggesting activation of the H2 receptor and cAMP-dependent protein kinase A. However, histamine treatment inhibited Raf-1 but not MAP kinase activation following treatment with either platelet-derived growth factor or epidermal growth factor, implying a Raf-1-independent MAP kinase activation pathway. In summary, our data suggest a model whereby 5-HT activates MAP kinase via a protein kinase C/Raf-1 pathway, and histamine attenuates MAP kinase activation by serotonin via activation of cAMP-dependent protein kinase A and inhibition of Raf-1.

Animals↗

PubMed1995

Lymphomatous meningoencephalitis in a patient with HAM/TSP.

A case of lymphomatous meningoencephalitis in a 23 year old Brazilian patient with HTLV-I/II associated myelopathy is reported. The patient was admitted to the hospital with a clinical picture of decreased consciousness level, stiffness of the neck and previous diagnosis of myeloneuropathy. CSF examination showed lymphocytosis with blastic cells and antibodies against HTLV-I/II.

Adult↗

PubMed1995

Pulmonary involvement in patients with HTLV-I associated myelopathy.

Pulmonary involvement in HTLV-I patients has been identified by several authors in Africa, Japan and Brazil. The objective of this controlled study is to establish an association between HAM and lymphocytosis in the bronchoalveolar fluid (BAL). Thirty-five adult patients with non-traumatic and non-tumoral myelopathy filled out a detailed historical survey and underwent a neurological examination, a thoracic radiological evaluation and a CSF examination. Of the patients in this sample, 22 were diagnosed with HTLV-I associated myelopathy and 13 had myelopathies with other etiologies. Lymphocytosis in the BAL fluid was detected in 18 (82%) of the HAM patients and in 2 (15%) of non-HAM patients. We concluded that the lung represents an important organ in the pathogenesis of HAM.

Adult↗

PubMed1994

Genetic variation of foot-and-mouth disease virus during persistent infection in cattle.

Genetic variation of foot-and-mouth disease virus O1 Campos has been analyzed in consecutive isolates recovered over a one- or two-year period from four cattle with experimental persistent infection. Comparisons of RNase T1 two-dimensional maps and nucleotide sequences of the VP1-coding region revealed a continual, although irregular, increase in the fixation of mutations as the infection progressed. Most changes were not conserved in consecutive isolates. These results, together with the substantial rates of genomic variation observed between some pairs of strains recovered at close time periods, suggested the coexistence of heterogeneous populations in which variants evolve independently from each other, and predominate at irregular time intervals. Furthermore, non-related patterns of variation were observed in the four animals. Similarly, genetic diversity of representative strains from major serotype O outbreaks in endemic disease regions of southeastern Brazil and central eastern Argentina which occurred between 1958 and 1983, suggested that outbreak strains are also likely to represent fluctuations of heterogeneous populations which evolve independently from each other. The possible role of persistent infections in the introduction of variant populations in the field is discussed.

Amino Acid Sequence↗

PubMed1994

[HTLV-1 associated myelopathies in the city of Salvador, Bahia].

Chronic myelopathy associated with human T-lymphotropic virus type I (HTLV-I) has been described in several endemic areas in Brazil. In Salvador, 102 patients with myelopathy were screened for HTLV-I/II by ELISA and Western blot assays. We found 36 patients with HTLV-I/II associated myelopathy confirming the high prevalence of HAM in Salvador. The initial complaint of our patients were urinary urgency, back pain and progressive unsteadiness on walking. On examination all of them had a spastic paraparesis, variable degrees of lower motor neuron syndrome, deep and superficial sensitive syndrome. MRI analysis revealed lesions in the periventricular white matter in addition to atrophy of the thoracic spinal cord. Clinical and magnetic resonance findings reveal that the inflammatory lesions of HAM involve not only the spinal cord but also the brain and peripheral nervous system.

Adolescent↗

PubMed1994

[HTLV-I-associated myelopathy: a systemic disease].

Chronic myelopathy associated with T-lymphotropic virus type I (HAM) has been described as an endemic disease in several areas of the world mainly in Asia, Africa and Latin America. The involvement of the central and the peripheral nervous system by HTLV-I observed in South America and Africa points out that this disease is a leukoencephalomyeloneuropathy. Several authors reported involvement outside the nervous system (as uveitis, lymphocytic alveolitis and arthritis, among others) in patients with HAM. In this paper we emphasize that HAM is a systemic disease whose cofactors determine the clinical picture in each patient.

Humans↗

PubMed1993

Potency control of foot-and-mouth disease vaccine in cattle. Comparison of the 50% protective dose and the protection against generalization.

Potency tests of a total of 658 foot-and-mouth disease (FMD) vaccine batches by bovine protective dose (PD50) showed that 22% of the tests did not follow the expected theoretical model and the results could not be interpreted because of the lack of a dose-response relationship. The protection against generalization (PG) method, using undiluted vaccine, proved to be highly reliable from the analysis of the results of 65 replicate potency tests of three hydroxide-saponin (HS) vaccines and two oil-adjuvanted (OL) vaccines. The PG results were consistent in 64 out of the total of 65 tests. The data obtained indicated that, with regard to direct tests in cattle, the PG test is the preferred method for FMD vaccine potency control. This study also showed that the incorporation of a reference vaccine in routine potency tests is essential to ensure normality of the test system and that good quality HS and OL FMD vaccines may maintain immunogenic stability for at least 27 and 36 months, respectively, when stored at 2-8 degrees C.

Animals↗

PubMed1993

Diagnosis of persistent aphthovirus infection and its differentiation from vaccination response in cattle by use of enzyme-linked immunoelectrotransfer blot analysis with bioengineered nonstructural viral antigens.

A highly sensitive enzyme-linked immunoelectrotransfer blot (EITB) assay, capable of detecting aphthovirus-specific antibodies to replicating virus in sera from cattle with persistent infection, was developed. The assay uses a set of purified recombinant DNA-derived nonstructural viral antigens as serologic probes in lieu of the traditionally used virus infection-associated antigen(s) partially purified from baby hamster kidney-infected cells. Sera from cattle with experimentally induced aphthovirus infection were analyzed sequentially by EITB at various postinoculation days, and the results were compared with those obtained by currently used techniques. It was established that, in all cases, EITB results remained positive at late stages of infection. At these times, results of virus infection-associated antigen-antibody determinations were negative by use of the conventional immunodiffusion in agarose gel test, and virus was recovered only occasionally from esophageal-pharyngeal fluid. Specificity of the EITB test was indicated by negative results for sera from cattle in aphthovirus-free areas, including samples from cattle infected with a variety of bovine viruses. Moreover, the test eliminated a substantial number of false-positive results (on the basis of the immunodiffusion in agarose gel assay) caused by reactivity of sera from vaccinated cattle. Use of additional nonstructural viral antigens, other than RNA polymerase, is proposed to differentiate between seropositivity resulting from vaccination or infection. This procedure may be considered to have potential applications as a sensitive, safe, rapid, and economic field test for specific diagnosis of persistent aphthovirus infection in affected animals.

Animals↗

PubMed1991

Diagnosis of sputum smear-negative forms of pulmonary tuberculosis by transthoracic fine-needle aspiration.

We reviewed 25 patients submitted to transthoracic fine-needle aspiration (TFNA) who had a final diagnosis of pulmonary tuberculosis. In all cases, bacteriological stains and cultures of sputum and bronchial washing had been performed before admission and were negative. According to the material obtained from the procedure, the aspirates were divided in three groups: diagnostic (Ziehl-Neelsen and/or culture positive, n = 8, 32%), suggestive (granulomatous inflammatory changes, n = 10, 40%) and inconclusive (nonspecific inflammatory changes, isolated giant cells and/or blood, n = 7, 28%). On chest X-ray, 12 patients had opacities with the greatest diameter not exceeding 4 cm. All aspirates in the diagnostic group were from patients with this type of lesion, while all the inconclusive aspirates belonged to patients with larger lesions. As complications, 1 patient needed thoracic drainage for pneumothorax and 3 patients had haemoptyses. Thus TFNA has a place in the diagnosis of suspected pulmonary tuberculosis when more simple methods have failed, and its effectiveness seems to be increased when the lesions do not exceed 4 cm in diameter.

Adolescent↗

PubMed1991

Expression of the aphthovirus RNA polymerase gene in Escherichia coli and its use together with other bioengineered nonstructural antigens in detection of late persistent infections.

A plasmid has been constructed containing the DNA sequences that direct the expression of the aphthovirus RNA-dependent RNA polymerase (virus infection-associated antigen, VIAA) in its native form. The aphthovirus polypeptide was designed to contain only a single additional amino acid, the N-terminal methionine. The recombinant protein has been purified and used in enzyme-linked immunoelectrotransfer blots to detect aphthovirus-specific antibodies in the sera of persistently infected animals. Furthermore, studies were carried out to test the hypothesis that antibodies against other nonstructural antigens appear in the sera of these animals. It was established that antibodies against polypeptides 3A and 3B can serve as complementary markers for late aphthovirus-carrier state detection. The considerable potential of this approach to detect aphthovirus-specific antibodies, when the isolation of infectious virus is not possible, was demonstrated. Negative results were obtained in animals from virus-free areas and in vaccinated cattle. This assay has the added advantage that no infectious or noninfectious virus is involved during antigen production.

Animals↗

PubMed1988

Heterogeneity of the polyribocytidilic acid tract in aphthovirus: changes in the size of the poly(C) of viruses recovered from persistently infected cattle.

A sample of aphthovirus type C3 strain Resende carrying two polyribocytidilic acid [poly(C)] tracts was cloned in tissue culture. One clone with a poly(C)-rich tract of about 145 nucleotides long (clone 3B) and another with a poly(C)-rich tract of about 230 nucleotides long (clone 12) and a mixture of both were injected intralingually into three steers. Samples from all three animals were recovered during the acute phase of the disease, from the blood and from the feet, and at various days after inoculation from the oesophageal-pharyngeal (OP) fluids. Analysis of the viral RNAs of the positive samples by means of RNase T1 maps on one- and two-dimensional gels showed (1) changes in the electrophoretic mobility of the poly(C)-rich tracts of viruses recovered from the OP fluids at various times after infection; (2) selection of virus populations with poly(C)-rich tracts of increased size; (3) later on, changes in the patterns of oligonucleotides of persistent viruses. These variations may lead to the production of new strains with altered biological properties that may contribute to the maintenance and spread of these viruses in the field.

Animals↗

PubMed1988

Behavior of intertypic recombinants between virulent and attenuated aphthovirus strains in tissue culture and cattle.

Two aphthovirus intertypic recombinants between the virulent strain A Venceslau and guanidine-resistant attenuated mutants of either strain C3 Resende or O1 Campos were obtained in an attempt to establish the region(s) of the viral genome responsible for attenuation in cattle. Recombinants that inherited the 3' half of the genome from either attenuated parent and the 5' half from the virulent strain were selected and analyzed with respect to their ability to grow in cells of bovine origin and for their virulence in cattle. The results obtained support our previous conclusion, derived from studies with homotypic recombinants between attenuated aphthovirus type O1 and its original virulent strain, that the host range restriction phenotype for fetal bovine kidney cells of the attenuated strain is inherited from the 3' half of the genome. For the intertypic recombinants, however, this restriction is enhanced, presumably by the presence of a heterologous 5' half of the genomic region. In addition, we demonstrate that the results in vitro correlate with those of virulence tests in cattle.

Animals↗

PubMed1988

Rapid selection of genetic and antigenic variants of foot-and-mouth disease virus during persistence in cattle.

Rapid evolution of foot-and-mouth disease virus (FMDV) is documented during persistent infections of cattle. The carrier state was established experimentally with plaque-purified FMDV of serotype C3. Virus was recovered from the esophageal pharyngeal area of the animals up to 539 days postinfection. Analysis of capsid proteins by electrofocusing and by electrophoretic mobility of the genomic poly(C)-rich tract suggested heterogeneity in several isolates and sequential dominance of viral subpopulations. Nucleotide sequences of the VP1-coding region of the parental FMDV C3 clones and of seven isolates from the carrier cattle showed point mutations that represented rates of fixation of mutations of 0.9 X 10(-2) to 7.4 X 10(-2) substitutions per nucleotide per year; 59% of the base changes led to amino acid substitutions, some of which were located within residues 135 to 151, a region involved in neutralization of FMDV. In the esophageal pharyngeal fluid samples, FMDV C3-neutralizing activity was present. Antigenic variation was demonstrated with monoclonal antibodies raised against FMDV C3. Two isolates from carrier cattle differed from the parental virus by 10(2)- or 10(3)-fold decreased reactivity with neutralizing monoclonal antibodies. We suggest that persistent, inapparent infections of ruminants, in addition to being a reservoir of virus, may promote the rapid selection of antigenically variant FMDVs.

Amino Acid Sequence↗

PubMed1988

The natural family planning programme in Bangladesh.

A 12-month evaluation of the Ovulation Method of Natural Family Planning programme in Bangladesh is presented. Four hundred and forty-eight women entered the programme, 232 for spacing, 184 for limiting, and 32 to achieve pregnancy. Of the participating couples, 79% lived in rural areas and 20.3% were illiterate. The 416 who learned the ovulation method for avoiding pregnancy completed 2,358 months of use, with 14 unplanned pregnancies during the study period, which represents a pregnancy rate of 7.2 according to the Pearl Index. The discontinuation rate in the 12-month period was 2.4%.

Adolescent↗

PubMed1978

Susceptibility of various FMDV strains to urea.

Resistance to urea in vitro at 37 degrees C varied for each FMDV strain analysed. The urea marker did not correlate with other markers such as resistance to acid, resistance to acidity or size of plaques under agar on BHK21/13 cells. The resistance to urea of subtypes A24 Cruzeiro, O1 Caseros and C3 Resende varied in accordance with their antigenic potency when administered to swine as a trivalent water-in-oil emulsion type vaccine.

Antigens, Viral↗

PubMed1977

Potentiation of FMD vaccines with polycationic-nucleic acid complexes.

The effect of various polycations on the immune response potentiated with poly I:C was studied. It was found that low molecular weight polycations had no potentiating effect. Polylysine was ineffective whereas protamine was superior to lysozyme, poly-arginine, poly-histidine, DEAE-Dextran and histone. A foot-and-mouth disease trivalent vaccine composed of strains A24 Cruzeiro, O1 Caseros and C2 Resende elicited no immune response in swine when adjuvanted with aluminium hydroxide but was effective when emulsified in oil. In general, the immune response was potentiated ten-fold when the emulsion contained poly I:C. The antibody production was in most cases further potentiated by a factor of ten when the nucleic acid double-strand was complexed with 1 : 10 (w/w) DEAE-Dextran. Protamine was as effective, or perhaps even more, than DEAE-Dextran to this effect. Guinea pigs vaccinated with a water-in-oil emulsion type monovalent C3 vaccine showed an increase in antibody production when the vaccine contained poly I:C or poly I:C complexed with 1 : 10 (w/w) protamine.

Adjuvants, Immunologic↗