RESUMO

Two experiments were conducted to assess a hormonal strategy developed to reduce animal handling for timed artificial insemination (TAI) with sex-sorted semen. Four-hundred ninety-one (491) suckled beef cows received a progesterone (P4) intravaginal device and 2 mg intramuscular (im) injection of estradiol benzoate (EB) on a randomly chosen day of the estrus cycle (Day 0) in Experiment 1. Cows were treated with 500 µg of sodic cloprostenol (PGF2α) and with 300 IU of eCG at P4 device removal (Day 8); these cows were also randomly assigned to receive 1 mg of estradiol cypionate (EC) administered at P4 device removal (treatment EC-0h) or 1 mg of EB 24 h after P4 device removal (treatment EB-24h). Both treatments were timed inseminated (TAI) with sex-sorted semen 60 h after P4 device removal. Cows treated with EC-0h presented higher pregnancy rate per AI (P/AI) [45.0% (113/251)] than the ones treated with EB-24h [35.4% (85/240); P = 0.03)]. A subset of cows (n = 26) were subjected to ultrasound examination every 12 h after P4 device removal for 96 h in the row in order to determine the time of ovulation. Similar interval between device removal and ovulation was recorded for EB-24h = 70.0 ±â€¯2.9 h vs. EC-0h = 66.0 ±â€¯2.8 h (P = 0.52). Five-hundred ninety-one (591) cows were subjected to the same synchronization protocols and treatments (EC-0h or EB-24h). In addition, they were randomly assigned to a 2 × 2 factorial arrangement aiming at determining the effects of treatment with estradiol (EC-0h vs. EB-24h) and of semen type (Sex-sorted vs. Non-sex-sorted semen). All animals were timed inseminated 60 h after P4 device removal. There was no interaction (P = 0.07) between the ovulation inducer and semen type. The EC protocol led to greater P/AI than EB (P = 0.03). Greater (P = 0.01) P/AI was achieved through treatments with non-sex-sorted semen rather than with sex-sorted semen [sex-sorted (EB-24h = 49.0%; EC-0h = 51.0%) vs. non-sex-sorted semen (EB-24h = 52.4%; EC-0h = 68.2%)]. Therefore, EC administered at P4 device removal resulted in greater P/AI. Furthermore, the EC-0h protocol allowed reducing suckled beef cow handing for timed artificial insemination with sex-sorted semen.

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RESUMO

En 1984 se distribuyó a los laboratorios de 14 estados brasileños un estuche de inmunoensayo enzimático para la detección de rotavirus y adenovirus. El estuche fue preparado por el Departamento de Virología de la Fundación Oswaldo Cruz como parte de un proyecto para la detección de agentes virales en muestras fecales de niños con diarrea. La vigilancia ulterior duró de 3 a 5 años, y en un taller celebrado en Belém en 1991 se examinaron los resultados obtenidos por todos los laboratorios que analizaron mas de 300 muestras fecales. Los resultados revelaron la presencia de rotavirus en 13 por ciento a 20 por ciento de los especímenes investigados y una frecuencia máxima de resultados positivos de mayo a septiembre, que es la estación "invernal" o seca en los estados de las zonas central y meridional del Brasil pero no en las zonas tropicales situadas más al norte. Se detectaron adenovirus en 0,7 por ciento a 5,5 por ciento de las muestras analizadas, sin ninguna variación estacional. También se detectaron muchos otros agentes virales productores de gastroenteritis (entre ellos astrovirus, pequeños virus de estructura esférica, calicivirus y ratavirus del grupo C) en los centros donde se usó el microscopio electrónico. El picobirnavirus, microorganismo que hasta el momento no se había asociado con la gastroenteritis en el ser humano, se descubrió por medio de la electroforesis en gel de poliacrilamida en especímenes enviados a diversos centros que usaban esta técnica. Las vacunas contra los rotavirus, actualmente en fase de experimentación, serían de gran utilidad en el Brasil, donde tales virus son la causa más frecuente de diarrea infantil. Se necesitarán mejores técnicas de diagnóstico para determinar la importancia de los demás agentes virales

Se publica en inglés en Bull. PAHO. Vol. 27(3), 1993

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RESUMO

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.

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RESUMO

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 proyect 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 o more fecal specimens were reviewed at a workshop held in Belém. These results showed that rotavirus had been detected in 13 percent to 20 percent of the specimens tested, with positive specimens appearing to peak in the May to September "winter" or dray season in Brazil's central and southern states but not in the more tropical northern areas. Adenovirus, detected in 0.7 percent to 5.5 percent of the specimens tested for it, showed no seasonal variations. Many other viral agent know 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 no 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

This article will also be published in Spanish in the Bol. Oficina Sanit. Panam. Vol. 116(5):27-36, 1994

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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.

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A total of 138 patients with the age of 4 months to 57 years were attended in different hospitals of São Paulo State with aseptic meningitis. A probable new agent was isolated from the cerebrospinal fluid of 35 of 53 specimens examined. Replication of the agent with similar characteristics was detected by CPE produced in the MDCK cell line. Virus-like particles measuring about 40 nm in diameter were observed by negative staining electron microscopy. No hemagglutinating activity was detected at pH 7.2 by using either human, guinea pig, chicken and at pH ranged 6.0-7.2 with goose red blood cells. The agent was not pathogenic to newborn or adult mice. Virus infectivity as measured by CPE was sensitive to chloroform and not inhibited by BuDR, suggesting that agent is an enveloped virus with RNA genome.

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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.

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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.

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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).

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