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Biomedical subjects

J A Candeias

Publications and source records attributed to J A Candeias.

At least 19 recordsLinked to original sources

Adenovirus genome types isolated from stools of children with gastroenteritis in São Paulo, Brazil.

In a prospective one-year study of acute gastroenteritis in hospitalized children less than 2 years of age, in São Paulo (Brazil), adenoviruses were detected by specific enzyme immunoassay (El-ARA) in 7 of 67 (10%) ill children and in 9 of 79 (11.4%) controls. They were the sole recognizable agent of diarrhea in 6 ill children. In another child these viruses were detected in a dual infection with astrovirus. Enteric adenoviruses (Ad40/41) were the most common serotypes detected in children with diarrhea (3/7) and Ad7 the serotype most detected in the controls (5/9), associated with lower respiratory tract infection. Thirteen adenovirus strains, isolated in HEp2 or HEK-293 cells, were characterized by seroneutralization and restriction enzyme analysis. The established adenoviruses were typed as AV-7-D5 (five associated to lower respiratory tract infection and one to diarrhea), AV-1-D10 (one diarrhea case), AV-31-D2 (two controls with respiratory infection), and two isolates as AV-12-D7, a new genome type. One subgenus D isolate, serotype 28, with restriction patterns different from those of the prototype, remained untyped. Only one enteric adenovirus could be typed. The restriction patterns of this isolated were similar to those of the prototype AV-41-D1. The genome type of the other three enteric adenoviruses could not be determined.

Acute Disease↗

A combined staphylococcal coagglutination assay for rapid identification of rotavirus and adenovirus (COARA).

An improved staphylococcal coagglutination test was developed for rapid detection, in a single assay, of rotavirus and adenovirus in stool samples (COARA). Suspensions of Staphylococcus aureus coated respectively with anti-rotavirus and anti-adenovirus sera were used to identify these viruses in 327 stool samples of children. The samples were also tested by an enzyme immunoassay. The data analysis has demonstrated a high degree of correlation between the two assays.

Adenoviridae↗

National laboratory surveillance of viral agents of gastroenteritis in Brazil.

In 1984 an enzyme immunoassay for rotavirus and adenovirus developed in the Virology Department of the Oswaldo Cruz Foundation was distributed to laboratories in 14 Brazilian states as part of a project to survey viral agents in fecal specimens from children with diarrhea. The ensuing surveillance continued for 3 to 5 years, and in 1991 the results obtained by all laboratories that tested 300 or more fecal specimens were reviewed at a workshop held in Belém. These results showed that rotavirus had been detected in 13% to 20% of the specimens tested, with positive specimens appearing to peak in the May to September "winter" or dry season in Brazil's central and southern states but not in the more tropical northern areas. Adenovirus, detected in 0.7% to 5.5% of the specimens tested for it, showed no seasonal variations. Many other viral agents known to cause gastroenteritis (e.g., astrovirus, small round-structured viruses, calcivirus, and group C rotavirus) were detected at centers that used electron microscopy. Picobirnavirus, a novel agent not yet associated with gastroenteritis in humans, was found by polyacrylamide gel electrophoresis in specimens from a number of centers using this technique. Vaccines to prevent rotavirus that are currently under development would be of great use in Brazil, where rotavirus is the most common cause of childhood diarrhea. Improved diagnostics will be required to assess the importance of the other viral agents.

Acute Disease↗

Comparison of staphylococcal co-agglutination with other assays for rapid diagnosis of rotavirus infection in humans, calves and piglets.

Co-agglutination was used for rapid diagnosis of rotavirus infection. Staphylococcus aureus Cowan I sensitized with rabbit antiserum to rotavirus demonstrated the presence of this virus in stools of children, calves and piglets with clinical signs of diarrhea. A total of 415 fecal samples were examined by the co-agglutination test and the results were compared with those of ELISA, electrophoresis in polyacrylamide gel and latex agglutination. The co-agglutination test, when compared to these three methods, presented a correlation which varied between 87.2 and 94.2%.

Adenoviridae↗

Enteropathogens associated with acute diarrheal disease in urban infants in São Paulo, Brazil.

To determine the prevalence and epidemiology of enteropathogens in acute infantile diarrhea, 500 infants less than or equal to 12 months of age with diarrhea and 500 age-matched control subjects coming to a São Paulo emergency room were studied. Enteropathogens were identified in 55% of case infants and 10% of controls; enteropathogenic Escherichia coli (EPEC) of classic EPEC serotypes producing EPEC adherence factor (EAF) (26% of case infants), rotavirus (14%), Salmonella species (8%), enterotoxigenic E. coli (7%), and Shigella species (5%) were associated with diarrhea. Isolation of EAF+ classic EPEC decreased with increasing age of cases and peaked in spring, whereas rotavirus was least common in early infancy and peaked in fall and winter. Bloody stool had a 36% positive predictive value for Shigella infection, EAF+ classic EPEC were highly resistant to antimicrobial drugs. Among poor São Paulo infants, EAF+ classic EPEC equaled or exceeded rotavirus throughout the year as a cause of diarrhea bringing children to medical attention.

Acute Disease↗

[Genetic engineering].

This paper deals with the progress made in genetic engineering techniques, capable of altering the genetic potential of an organism, either by the introduction or the suppression of new structural genes. Some of the general applications are described as are also, more particularly, their uses in the field of medicine. A critical analysis of the benefits and risks involved is also undertaken.

Antibodies, Monoclonal↗

[Electropherotypes of rotavirus in children with and without gastroenteritis].

It was defined the electropherotypes of rotavirus identified in stools of a groups (named "case") of 500 children with diarrhea, ranging in age from 0 to 12 months. A group (named "control") of 500 children of the same age group, without diarrhea or respiratory infections, were evaluated. Human rotavirus was detected in 14.8% of the children with diarrhea. Of the positive samples 5 had the "short" and 11 the "long" electropherotype. In the control group rotavirus was detected in 0.8% of children and all the three positive samples had "long" electropherotype.

Electrophoresis, Polyacrylamide Gel↗

New genome types of adenovirus types 1, 3, and 5 isolated from stools of children in Brazil.

During an epidemiological survey made in São Paulo (Brazil), fecal specimens were periodically collected from 100 randomly chosen babies from birth to the age of 18 months. The stools, routinely collected each month and also collected each time a child presented any sign of disease, were screened for the presence of adenoviruses. Sixteen adenovirus strains, isolated from the stools of healthy and ill children, were characterized by restriction enzyme analysis. Five isolates were from subgenus A, five were from subgenus B, four were from subgenus C, and two were from subgenus D. All but two showed some restriction patterns different from those of the 42 human adenovirus prototypes and all the genome types described up to now. No fastidious adenovirus (subgenus F, serotypes 40 and 41) was encountered in the stools examined. We report here the restriction enzyme analysis of isolates of subgenera B and C. The following new designation genome types are proposed: Ad3e1 (subgenus B) and Ad1d, Ad5a1, and Ad5a2 (subgenus C).

Adenoviridae Infections↗

Rotavirus identification in jejunal juice and stools of acute and chronic forms of infantile gastroenteritis.

1. The present study investigates, by means of a combined enzyme immunoassay for rotaviruses and adenoviruses (EIARA), the occurrence of rotaviruses in stools and jejunal juices from 31 children with acute diarrhea and 18 with chronic diarrhea. 2. Stools from 8 acute cases contained rotaviruses (26%). In two of these cases rotaviruses were also detected in the jejunal juice. 3. In the chronic diarrhea group we identified rotaviruses in the stools of one patient and in the jejunal juice of another. 4. Some of the electropherotypes of the rotaviruses identified showed different patterns of RNA migration. 5. Abnormalities of the jejunal mucosa were characterized in 6 acute rotavirus-positive cases. No morphological or functional abnormalities of the intestinal mucosa were observed in the chronic diarrhea rotavirus-positive cases.

Diarrhea, Infantile↗

Diarrheal diseases in Brazil: clinical features of rotavirus-associated gastroenteritis in children.

This study was undertaken to detect the presence of rotavirus in the stools of children with gastroenteritis, using the enzyme-linked-immunosorbent assay (ELISA), and to compare the signs and symptoms of rotavirus-positive and -negative children. Over a period of fifteen months, 367 children ranging in age from less than 1 month to 5 years or more with diarrhea and 86 children, in the same age group, without diarrhea and respiratory infections, used as controls, were evaluated. Human rotavirus was detected in 15.8% of children with diarrhea attending out-patient clinics and in 28.9% of patients seen by general practitioners. In the control groups, the percentages of identification of rotavirus were 1.4% and 5.5% respectively. Frequency of other enteropathogens was determined. The hydration state of diarrheal cases, different clinical symptoms and the type of medical attendance distinguished the rotavirus positive from the rotavirus negative patients.

Brazil↗

A virus with a bisegmented double-stranded RNA genome in rat (Oryzomys nigripes) intestines.

Examination of the intestinal contents of free-living Oryzomys nigripes rats by PAGE revealed two sharply defined bands that could be stained by ethidium bromide or by silver nitrate with comparable intensities. The molecules forming these bands were susceptible to digestion by pancreatic RNase A but not by RNase T1 or by DNase I. Their lengths were estimated to be about 2.6 and 1.5 kbp, respectively, by comparison with rotavirus SA11 genome segments. They cosedimented in CsCl gradients at a density of 1.39 to 1.40 g/ml, together with uniform particles approximately 35 nm in diameter with indistinct surface structure. It is suggested that these particles represent an as yet undescribed virus with a bisegmented double-stranded RNA genome, for which the name 'picobirnavirus' is proposed.

Animals↗