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O Fernandes

Publications and source records attributed to O Fernandes.

At least 55 records · Page 3Linked to original sources
PubMed1998

American cutaneous leishmaniasis associated with HIV infection: report of four cases.

OBJECTIVE: A report of four cases of American cutaneous leishmaniasis associated with HIV infection is presented. BACKGROUND: The association of mucocutaneous leishmaniasis and HIV infection is rare. Only 15 cases have been reported in the literature thus far. SUBJECTS: Four new cases are described and the differences between the clinical presentation in immunocompromised and immunocompetent patients are emphasized. CONCLUSIONS: Multiple cutaneous lesions plus mucosal involvement characterize the clinical presentation of American cutaneous leishmaniasis in association with HIV infection in the majority of the cases. A serological investigation for HIV infection is recommended for patients presenting with this type of clinical picture, especially if the patient is a young male.

AIDS-Related Opportunistic Infections↗
PubMed1998

[The use of endoprosthesis in superior vena cava syndrome caused by lung neoplasms].

We present six cases of superior vena cava syndrome caused by a malignant tumor that were treated by percutaneous endoprostheses. The technique is described and the results evaluated. In one case there was acute thrombosis of the endoprosthesis that was treated by urokinase. No other complications were observed. A patient died one month later due to progression of the tumor. The remaining cases were asymptomatic for longer than 6 months. It was concluded that endoprostheses for superior vena cava syndrome are efficient, with quick improvement of the symptomatology.

Adult↗
PubMed1996

DNA markers define two major phylogenetic lineages of Trypanosoma cruzi.

Parasitic protozoa within the taxon Trypanosoma cruzi are considered to be derived from multiple clonal lineages, and show broad genetic diversity as a result of propagation with little or no genetic exchange. We have analyzed a wide sample of T. cruzi isolates from vertebrate and invertebrate hosts by PCR amplification of a ribosomal RNA gene sequence, a mini-exon gene sequence and random amplified polymorphic DNA (RAPD). Amplification of the distinct rDNA and mini-exon gene sequences indicated a dimorphism within both of the tandemly-repeated genes: 125 or 110 bp products for rDNA and 300 or 350 bp products for the mini-exon. Within individual isolates, one of three associations was observed: the 125 bp rDNA product with the 300 bp mini-exon product (defined as group 1), the 110 bp rDNA product with the 350 bp mini-exon product (defined as group 2) and the presence of both rDNA amplification products with the mini-exon group 1 product (group 1/2). The RAPD analysis showed variability between individual isolates, however, tree analysis clearly indicated the presence of two major branches. Interestingly, the rDNA/mini-exon group 2 isolates correlated precisely with one branch of the RAPD-derived tree; group 1 and group 1/2 isolates correlated with the other branch. Our studies show a clear division of T. cruzi into two major lineages presenting a high phylogenetic divergence. Hypotheses are discussed to explain the origin of the two lineages as well as isolates that are hybrid for group 1 and 2 rDNA markers.

Animals↗
PubMed1996

Detection and identification of human pathogenic Leishmania and Trypanosoma species by hybridization of PCR-amplified mini-exon repeats.

A single pair of PCR primers within a conserved region of the mini-exon repeat was used to amplify the repeats from 10 species of pathogenic Leishmania belonging to four major clinical groups and also from three species of Trypanosoma. Oligonucleotide hybridization probes for the detection and identification of the PCR-amplified repeats were constructed from alignments of mini-exon intron and intergenic sequences. The probes generated from mini-exon intergenic regions of the L. (V.) braziliensis, L. (L.) donovani, and L. (L.) mexicana species hybridized specifically to their cognate groups without discriminating between the species within the groups. The probes for L. (L.) major and L. (L.) aethiopica were species-specific, while the L. (L.) tropica probe also hybridized with the L. (L.) aethiopica mini-exon repeat. The mini-exon intron-derived probes for T. cruzi, T. rangeli, and T. brucei were species-specific. This method involving the detection of specific PCR-amplified products produced using a single primer set represents a novel sensitive and specific assay for multiple trypanosomatid species and groups.

Animals↗
PubMed1995

The mini-exon genes of three Phytomonas isolates that differ in plant tissue tropism.

The tandem mini-exon gene repeat is an ideal diagnostic target for trypanosomatids because it includes sequences that are conserved absolutely coupled with regions of extreme variability. We have exploited these features and the polymerase chain reaction to differentiate Phytomonas strains isolated from phloem, fruit or latex of various host plants. While the transcribed regions are nearly identical, the intergenic sequences are variable in size and content (130-332 base pairs). The mini-exon genes of these phytomonads can therefore be distinguished from each other and from the corresponding genes in insect trypanosomes, with which they are oft confused.

Animals↗
PubMed1995

Comparison of the polymerase chain reaction and serology for the detection of canine visceral leishmaniasis.

The polymerase chain reaction (PCR) and serology was evaluated for the diagnosis of canine visceral leishmaniasis in Bahia, Brazil in a study of 125 dogs. The PCR was 100% sensitive in 25 dogs that had Leishmania demonstrated by either culture or hamster inoculation. It was 100% specific for 35 dogs from the northeastern United States, all were PCR negative. However, 22 of 54 Brazilian dogs that were culture-hamster inoculation-negative were positive by PCR. The nature of the PCR product was identified by hybridization with specific Leishmania probes. Whereas the sensitivity of serology in relationship to infection, as determined by hamster or culture assay was more than 80%, sensitivity of serology was only 63% when compared with PCR. These results raise questions about the use of serology to detect Leishmania infection in dogs, and suggest that the PCR might serve as a better gold standard to define Leishmania infection than culture or hamster inoculation.

Animals↗
PubMed1995

[Hemangiopericytoma].

A case of hemangiopericytoma located in the left upper thigh is presented. The literature is reviewed, particularly the clinical aspects and reference is made to arteriography and preoperative embolization.

Female↗
PubMed1994

Mini-exon gene variation in human pathogenic Leishmania species.

We have used polymerase chain reaction to amplify the mini-exon gene repeat from 18 Leishmania strains. DNA sequence analysis of the cloned products reveals high conservation of both the exon and intron (i.e. transcribed region). In contrast, variation is evident in both the length and primary sequence of the non-transcribed spacers. Dermotropic species of the New World subgenus Leishmania possess a 0.3-kb gene that differs from the 0.25-kb gene of New World dermotropic species of the subgenus Viannia. The Old/New World viscerotropic species and Old World dermotropic species possess a 0.4-kb mini-exon gene. However, the genes from the viscerotropic and dermotropic groups may be distinguished on the basis of sequence differences in the non-transcribed spacer. Comparative analysis of the -86 to -1 region from all species has been used to measure relatedness within the genus. In general, all the observed differences correlate with the four major groups of Leishmania (New World dermotropic Leishmania, New World dermotropic Viannia, Old World dermotropic Leishmania and viscerotropic Leishmania). Two of the three repeats cloned from L. donovani show short deletions. The missing sequence is flanked by direct, 7-bp repeats suggesting that the sequences may have been deleted by homologous recombination. Such rearrangements could account for the diversity detected in the non-transcribed spacers of the mini-exon genes.

Animals↗
PubMed1993

The mini-exon gene: a molecular marker for Endotrypanum schaudinni.

The mini-exon gene repeats from three different strains of Endotrypanum schaudinni have been amplified by the polymerase chain reaction (PCR). Sequence analysis of the cloned products shows the gene and intergenic region to be identical in two of the strains (LV86 and M6159); the intergenic region from the mini-exon gene of the third strain (LV59) is significantly different. The LV86 gene and an intergenic probe from the LV59 mini-exon gene do not cross-hybridize with the mini-exon gene from New World Leishmania species. These data provide the basis of a PCR assay to detect E. schaudinni and distinguish it from New World Leishmania species, and which should be applicable to epidemiological studies in insect vectors and mammalian reservoirs. The identification of two different mini-exon gene repeats in E. schaudinni isolates is indicative of further strain variation within this species.

Animals↗
PubMedDate not supplied

Trypanosoma cruzi in the sylvatic environment: distinct transmission cycles involving two sympatric marsupials.

Thirty-five specimens of Philander frenata and 36 Didelphis marsupialis were captured in the same Atlantic forest area of Brazil between 1992 and 1994. Haemocultures showed that 50% of P. frenata and 60% of D. marsupialis were infected with Trypansoma cruzi. Biological, biochemical and molecular characterization of the isolates suggested 2 distinct transmission cycles of T. cruzi occurred between these 2 sympatric didelphids. The T. cruzi isolates could be distinguished according to their association with each marsupial species. Biochemical characterization (multilocus enzyme electrophoresis) revealed 15 zymodemes; more variability was observed among the P. frenata isolates than among the isolates from D. marsupialis. The course of natural and experimental infection in D. marsupialis and P. frenata was different and suggested that D. marsupialis was more resistant to infection than P. frenata. In the studied area, P. frenata seems to be a more important reservoir of T. cruzi than D. marsupialis, since 40% of the characterized isolates from P. frenata belonged to the T. cruzi II group, which is associated with human infections.

Animals↗
PubMedDate not supplied

Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: a meta-analysis.

The objective was to determine the association of moderate to heavy caffeine consumption during pregnancy on spontaneous abortion and birth weight in humans. Data sources used included a computerized literature search of MEDLINE (1966-July 1996); EMBASE (1988-November 1996); Psychlit I (1974-1986); Psychlit II (1987-1996); CINAHL (1982-May 1996) and manual search of bibliographies of pertinent articles. Inclusion criteria were: English language research articles; pregnant human females; case control or cohort design; documented quantity of caffeine consumption during pregnancy; control group with minimal or no caffeine consumption (0 to 150 mg caffeine/d); documented data regarding spontaneous abortion and/or fetal growth. The exclusion criteria were: case reports; editorials; review papers. The methods section of each study was examined independently by two blinded investigators with a third investigator adjudicating disagreements. Two independent investigators extracted data onto a standardized form. A third investigator adjudicated discrepancies. We compared a caffeine-exposed group (>150 mg/d) and controls (0 to 150 mg/d), using Mantel-Haenszel pooling. Of the 32 studies meeting inclusion criteria, 12 had extractable data (6 for spontaneous abortion, 7 for low birth weight, 1 common study). Mantel-Haenszel odds ratio (CI95%) was 1.36 (1.29-1.45) for spontaneous abortion in 42,988 pregnancies. The overall risk ratio was 1.51 (1.39-1.63) for low birthweight (<2500 g) in 64,268 pregnancies. Control for confounders such as maternal age, smoking, and ethanol use was not possible. We concluded that there is a small but statistically significant increase in the risks for spontaneous abortion and low birthweight babies in pregnant women consuming >150 mg caffeine per d. A possible contribution to these results of maternal age, smoking, ethanol use, or other confounders could not be excluded.

Abortion, Spontaneous↗
PubMedDate not supplied

Mini-exon gene sequences define six groups within the genus Crithidia.

To develop molecular markers for lower trypanosmatids, we have examined the mini-exon gene repeats of 17 isolates that were classified as Crithidia by traditional methods. Representative repeats were amplified by polymerase chain reaction and the amplification products were cloned and used as hybridization probes against genomic DNA. Six hybridization groups of Crithidia were defined on the basis of the DNA blotting experiments. The three endosymbiont-bearing species (C. deanei, C. desouzai and C. oncopelti) and C. acanthocephali each belonged to single-member hybridization groups, while the C. fasciculata group contained additional named and undesignated species. The Crithidia lucilae thermophila probe hybridized to multiple undesignated isolates. The DNA sequence of the cloned products revealed that the specificity of the hybridization probes was due to substantial differences in the intron and the nontranscribed spacer regions. These data indicate substantial heterogeneity within the mini-exon gene locus of the taxon Crithidia.

Animals↗
PubMedDate not supplied

Chagas' disease in the Brazilian Amazon. III. A cross-sectional study (1).

Two serological surveys for Chagas' infection were carried out, in 1991 and 1993, respectively, using a conglomerate family samples from the residents in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 Km up-river from Manaus), using indirect immunofluorescent tests for anti-T. cruzi antibodies. In the first survey (1991), 628 blood samples from the residents of 142 dwellings were tested, showing positive in 12.7% for anti-T. cruzi antibodies and in 1993 an other 658 samples from residents of 171 dwellings showed positive in 13.7% of the tests, thus confirming the previous results. From 170 individuals with positive serology for T. cruzi antibodies, 112 (66%) were interviewed and submitted to electrocardiographic and clinical examinations; 82 (73.2%) of them gave consent for xenodiagnosis. From the 112 interviewed 52 (46.4%) recognized the triatomines as "piaçavas' lice", 48 (42.8%) knew the bugs from their work places being gatherers of piaçava fibers in rural areas and 19 (16.9%) said that have been bitten by bugs in their huts. Only 2 (2.4%) of 82 xenodiagnosis applied were positive for T. cruzi and 9 (8%) of the ECG had alterations compatible with Chagas' disease.

Adolescent↗