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A S Fonseca

Publications and source records attributed to A S Fonseca.

23 records · Page 2Linked to original sources

Molecular characterization of Brazilian infectious bursal disease viruses.

A reverse transcriptase-polymerase chain reaction (RT-PCR) procedure was used to amplify a VP2 gene fragment (248 bp) from infectious bursal disease virus (IBDV). The procedure allowed the detection of known IBDV strains from the United States, along with field isolates and commercial vaccines produced in Brazil. Amplified VP2 fragments were further characterized by restriction fragment length polymorphism (RFLP) analysis. From 55 Brazilian commercial flocks, 48 field samples were IBDV positive by RT-TCR. Vaccine RFLP patterns were found in 12 flocks, a pattern compatible with classic IBDV in one flock, four new patterns in 31 flocks, and a pattern compatible with very virulent (vv) IBDV in four flocks. Sequence analysis showed that the vvIBDV RFLP patterns were closely related to the vvIBDVs described in Europe and Asia. Phylogenetic analysis of the four new RFLP patterns showed that they were closely related to but distinct from other classic, variant, and vvIBDVs, suggesting a high prevalence of different IBDV strains in Brazilian commercial flocks.

Amino Acid Sequence↗

[Rheumatic fever: atypical joint manifestations].

The diagnosis of rheumatic fever (RF) continues to be a difficult one in Pediatrics, mainly because of the polymorphism of its clinical presentation and the lack of specific laboratory test. Among the Jones' major criteria, arthritis is the most frequent and the least specific. Ninety three children with RF who presented 117 flares of the disease were studied in the Department of Pediatrics, Escola Paulista de Medicina, between Dec. 1989 and Dec. 1991. The presence of arthritis was defined as an inclusion criterion. The diagnosis was based on history, physical and laboratory examinations (Modified Jones' Criteria). The mean age was 10 years and the sex ratio was 1 male: 1.4 female. In 45% of the flares, arthritis was the only major criterion. In 44% there were arthritis and carditis, in 7% arthritis and chorea and in 4% arthritis, carditis and chorea. In 64% of the flares the pattern of articular involvement was migratory and in 36% addictive. Polyarthritis and oligoarthritis were observed respectively in 64% and 36%. Monoarthritis was reported in 3%. The definitive diagnosis of RF with atypical articular involvement only was possible in the presence of carditis or chorea. The authors conclude that physicians should be aware of the atypical involvement observed in some cases of RF, specially when arthritis is the only major criterion.

Adolescent↗

Sydenham chorea: clinical and laboratory findings. Analysis of 187 cases.

Sydenham's chorea (chorea minor, St. Vitus dance, rheumatic encephalitis), described by Thomas Sydenham in 1686, is considered one of the major manifestations of rheumatic fever (1, 2, 3, 4). Clinically it is characterized by involuntary movements, hypotonia, dysarthria, emotional disorders, and less frequently, by other neurological manifestations such as weakness, headache, seizures and sensory abnormalities (1,4). The motor disorders may be generalized or unilateral, in this case constituting a hemichorea (3). Chorea may present associated to other rheumatic fever manifestations during an acute episode, or in isolated form, characterizing the so-called "pure" chorea (5, 6, 7). Its etiology and pathophysiological mechanisms are still unclear, although its relation with a previous pathophysiological group A Beta-hemolytic streptococcus infection is well established (8). There is also evidence of the participation of immunological mechanisms in its pathogenesis, such as the finding of serum anti-nucleus caudatus and anti-subthalamic antibodies (9) and increase in IgG levels in cerebrospinal fluid of patients with chorea (10). In developed countries due to the reduction in rheumatic fever incidence and decrease in frequency of chorea as its manifestation (3, 11), the latter has become rare. However, in developing countries rheumatic fever remains a public health problem. In Brazil, in the last years an increase in the incidence of chorea has been observed as part of the clinical picture of rheumatic fever (12). The present study reports the clinical and laboratory findings of 187 cases of Sydenham's chorea followed-up during the period of January 1980 to December 1990 in two university centers in the city of Sao Paulo, Brazil.

Adolescent↗