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H G Pereira

Publications and source records attributed to H G Pereira.

At least 19 recordsLinked to original sources
PubMed1990

A novel avian virus with trisegmented double-stranded RNA and further observations on previously described similar viruses with bisegmented genome.

The occurrence in chickens of small viruses with bisegmented double-stranded RNA (dsRNA) genome is confirmed and a new virus with similar properties but with three genome segments is described. Both differ from birnaviruses (Intervirology 25, 141-143, 1986) in having indistinct surface structure, smaller diameters (35 nm), and higher buoyant density (1.4 g/ml) in CsCl but are similar in these respects to viruses previously described in several mammals (Lancet 2, 103-104, 1988; J. Gen. Virol. 69, 2749-2754, 1988; Res. Vet. Sci, in press) under the tentative name of picobirnaviruses (PBV). Genome segment length estimations gave values of 2.6 and 1.9 kbp for the avian PBV and 2.9, 2.4 and 0.9 kbp for the trisegmented viruses. The source and pathogenic potential of these viruses remain to be established.

Animals↗
PubMed1989

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↗
PubMed1989

Viruses with bisegmented double-stranded RNA in pig faeces.

Viruses similar to the bisegmented double-stranded (ds) RNA picobirnaviruses described in human faeces and the intestinal contents of Oryzomys nigripes rats and guinea pigs were isolated from the faeces of pigs taken from several areas in the state of Sao Paulo, Brazil. Samples were collected from 912 pigs of several breeds, aged nine to 61 days, and assayed by polyacrylamide gel electrophoresis with silver staining and a combined enzyme immunoassay for rotavirus and adenovirus, using the simian rotavirus SA11 as control. Electrophoretic profiles resembling the bisegmented dsRNA viruses were detected in 106 pigs with 15.3 per cent occurring in animals with diarrhoea compared to 9.6 per cent in animals without diarrhoea.

Animals↗
PubMed1988

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↗
PubMed1987

A combined dot nitrocellulose-enzyme immunoassay for rotavirus and adenovirus.

A combined enzyme immunoassay using nitrocellulose membrane as solid support is described for the detection of rotavirus and adenovirus in faeces from children with gastroenteritis. Its sensitivity and specificity are comparable to those of a previously described assay performed on plastic microplates (Pereira et al. (1985) J. Virol. Methods 10, 21-28). The introduction of nitrocellulose membrane as support for the immune reactions greatly simplifies the multiple washing steps and precludes the need for disposable plastic plates.

Adenovirus Infections, Human↗
PubMed1986

Diarrhoea in mice infected with a human rotavirus.

Oral inoculation of newborn mice with the MET strain of human rotavirus produced transient diarrhoeal disease. Light and scanning electron microscopy showed typical rotavirus-induced morphological lesions in the villous epithelium of the small intestine consisting of extensive cytoplasmic vacuolation, villous necrosis and atrophy. Virus recovered from intestinal suspensions of infected mice showed the typical electrophoretic profile of the genome of the inoculated strain. Rotavirus antibody appeared in infected mice 10 to 20 days after inoculation but not in controls or nursing dams. The availability of a small animal model for experimental infection with human rotaviruses should prove useful for virulence and protection studies.

Animals↗
PubMed1986

Electrophoretic study of the genome of human rotavirus from Maceió, Brazil.

Rotaviruses were detected by enzyme immunoassay (EIA) in 53 (13.3%) of 397 fecal samples from children with acute gastroenteritis in the city of Maceió, Alagoas, Brazil. Polyacrylamide gel electrophoretic (PAGE) patterns characteristic of rotavirus double-stranded RNA were detected in 51 (96.2%) of the 53 EIA-positive samples. Of the RNA-positive samples, 1 (2%) was classified as subgroup 1 (short profile), 49 (96%) as subgroup 2 (long profile) and 1 (2%) could not be classified because of the absence of bands 10 and 11. The strains of subgroup 2 showed a great degree of electrophoretic heterogeneity and could be divided into several subcategories. Two samples showed splitting of one of the genome segments. PAGE, a very sensitive method capable of identifying rotavirus RNA genomes, has demonstrated that human rotaviruses detected in Maceió present many differences in RNA electrophoretic patterns.

Acute Disease↗
PubMed1985

In situ hybridization with biotinylated DNA probes: a rapid diagnostic test for adenovirus upper respiratory infections.

Adenovirus DNA was detected in cells from nasopharyngeal secretions of children with acute respiratory infections by in situ hybridization with biotinylated probes. The technique was easy to perform, giving rapid results which were well correlated with those of immunofluorescence assays of the same samples. Adenoviruses of subgroups B, C and E were detected equally well by probes prepared either from purified adenovirus type 5 or from a plasmid (A1) carrying a cloned insertion of BamH1 fragments C and D of adenovirus type 2 in pAT 153. The use of stable non-radioactive probes makes in situ hybridization a feasible assay for use in clinical laboratories with moderate resources.

Adenoviridae Infections↗
PubMed1985

A combined enzyme immunoassay for rotavirus and adenovirus (EIARA).

A combined enzyme immunoassay for rotavirus and adenovirus (EIARA) was developed as a double-antibody sandwich assay in which test samples are added to plastic wells coated with rotavirus or adenovirus goat antibody. The presence of antigens is detected by mixed-guinea pig antisera to the same viruses followed by rabbit anti-guinea pig IgG conjugated with peroxidase and subsequently by ortho-phenylenediamine substrate. Titrations of rotavirus (SA11) and adenovirus type 2 tissue culture grown viruses in the presence of separate capture sera and mixed detector sera revealed that the two virus-antibody reactions occurred independently and were not affected by each other. Comparison with another enzyme immunoassay for rotavirus, with immunoelectron microscopy and with polyacrylamide gel electrophoresis showed that EIARA is a sensitive and specific method for detecting rotaviruses and adenoviruses in faeces from children with gastroenteritis.

Adenoviruses, Human↗
PubMed1979

Classification of porcine enteroviruses by antigenic analysis and cytopathic effects in tissue culture: description of 3 new serotypes.

Porcine enteroviruses isolated in the United Kingdom between 1972 and 1976 were compared with the 8 serotypes previously described and with human coxsackie B virus types 1 to 6 for ability to grow in different cell lines. This allowed the classification of all strains into 3 broad groups according to type of cytopathic effect in IBRS-2 cells and further subdivision on the basis of production of cytopathic effect in BHK 21, HeLa and VERO cells. None of the porcine enterovirus strains was neutralized by antisera to human enteroviruses (Lim Benyesh-Melnick Pools) with the exception of swine vesicular disease virus, which was neutralised by coxsackie B5 antiserum. Antisera prepared either in gnotobiotic pigs or in guinea pigs against the 8 porcine enterovirus serotypes failed to neutralize 9 isolates which could be classified into 3 new serotypes, for which Nos. 9, 10 and 11 are proposed. Guinea pig sera could be used as an alternative to gnotobiotic pig sera for type differentiation.

Animals↗
PubMed1976

Data on a FMD virus of type "A" isolated in Italy in 1975.

A strain of FMD virus type A was isolated in a disease outbreak in Alessandria, Italy, in December 1975. Affected animals were young unvaccinated bovines and pigs of a very restricted region. No further spread has been observed. The strain was compared with some subtype strains of type A, including the Italian vaccinal strain. This Italy 1975 strain differs from all the other viruses included in the performed tests.

Animals↗
PubMed1975

Parvoviridae.

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Parvoviridae↗
PubMed1975

Adenoviruses of man and animals.

Adenoviruses are capable of causing natural infections in a wide variety of vertebrates, including amphibia, birds and mammals. Although frequently causing inapparent infections, they may be associated with diseases of varying severity and localizations. The clinico-pathological manifestations most commonly associated with adenovirus infections involve the respiratory tract and the ocular conjunctiva. Involvement of the digestive, renal and nervous systems may also be observed. A state of latency with persistence of infection for prolonged periods has been described in many hosts. Many adenovirus types are oncogemic under experimental conditions but none have been associated with naturally occurring tumours. Although the diseases caused by adenoviruses tend to be mild, this is not invariably the case and these viruses may give rise to serious epidemiological situations and represent a threat to life under certain circumstances in which the use of prophylactic vaccination may be indicated.

Adenoviridae↗
PubMedDate not supplied

A serological investigation of rotavirus infections in a shanty town population in Rio de Janeiro.

The presence of antibodies against rotavirus was investigated by enzyme immunosorbent assay (ELISA) in two distinct groups of children living in a shanty town in Rio de Janeiro. One hundred and thirty six plasma samples were randomly collected from children of 0 to 33 months (first group) and 255 serum samples were collected from other 85 children at ages of 2, 6 and 9 months (second group). A high percentage of antibodies were found in the newborn children and this rate decreased progressively until the age of 11 months, after which it increased again. At the age of 7 months, geometric mean antibody titers increased indicating that infection had occurred.

Antibodies, Viral↗