Ronaldo Pereira Dias

Medium-term cryopreservation of rabies virus samples

INTRODUCTION The cryopreservation of rabies virus has been described in detail in the literature. To date, little information is available on the use of cryoprotective agents for cold preservation of this virus, and the available data focus only on short-term virus preservation. In this study, we investigated the medium-term cryopreservation of samples of rabies virus using different cryopreservation protocols. METHODS The cryopreservation protocols for the rabies virus samples were performed at -20°C and were divided according to the variables of time and cryoprotectant type used. The laboratory tests (intracerebral inoculation of mice, viral titration and direct immunofluorescence) were performed at regular intervals (360 and 720 days) to assess the viability of the viral samples according to the different preservation techniques used. RESULTS After 1 year of cryopreservation, the fluorescence intensity of intracellular corpuscles of the rabies virus and the median survival time of the mice differed between the positive controls and the treatments with the cryoprotectants. After 2 years, most of the samples subjected to the cryopreservation protocols (including the controls) did not produce fluorescence. However, the virus samples exposed to the cryoprotectant sucrose (68% solution) responded positively in the direct immunofluorescence assay and in the intracerebral inoculation of the mice. CONCLUSIONS Medium-term cryopreservation of the rabies virus inactivates the viral sample. However, the cryoprotectant agent sucrose (68%) produces a preservative effect in cryopreserved rabies virus samples.

Influência da soropositividade ao vírus da artrite encefalite caprina no hemograma de cabras em lactação

The objective was to study the influence of caprine arthritis encephalitis in the blood count of goats during lactation. To this end, 38 F1 Anglo-Nubian x Saanen reproductive female goats, aged 14 to 38 months and body condition score between 2 and 3, were first tested by AGID and Western Blot, and divided into either a seropositive group (n = 19) or a seronegative group (n = 19). The groups were kept in separate paddocks, without physical contact, receiving the same nutritional and health management. The blood of these animals was collected by jugular venipuncture, monthly, from the partum period until the end of lactation, and their erythrogram and leukogram values were determined. At given moments, the seropositive animals showed morphological changes in red blood cells, with significant decrease in MCV, coupled with a significant increase of MCH and MCHC. There was no significant difference between the groups in the values of red blood cells and packed cell volume. The absolute values of monocytes and eosinophils of the seropositive animals, at certain moments, were significantly higher than the seronegative ones and above the normal range for goats.

Zoonotic importance of coming from dogs rotaviroses (Canis familiaris)

The rotaviroses are diseases caused by viruses, the genus Rotavirus, which are considered worldwide as one of the major enteric viruses that affect both humans and animals. Enteric disorders as a result of Rotavirus are observed more often in newborns and Revista Brasileira de Higiene e Sanidade Animal Brazilian Journal of Hygiene and Animal Sanity ISSN: 1981-2965

Potencial de diferenciação in vitro de células provenientes da geleia de Wharton de cordões umbilicais ovinos isolados em diferentes meios de cultivo

The mammalian Whartons jelly of umbilical cord (WJUC) is a promising source of multipotent cells, providing advantages due to ethical implications, ease of collection and the absence of teratomas in pre-clinical trials. Ovine multipotent cells have already been isolated from various tissues, however there are no reports using umbilical cords in this species. This study aimed to investigate the best medium to transport the umbilical cord, to isolate and maintain ovine WJUC cells and to compare in vitro growth and mesodermal differentiation potential. Eight ovine umbilical cords were obtained during parturition, sectioned and transported in six different media: MEM, low glucose DMEM, M199, RPMI 1640, PBS and saline. For each transportation medium, four culture media were used and the tissue was explanted in 24-well plates and cultured in MEM, low glucose DMEM, M199 and RPMI 1640, all with 10% FBS. Every experiment was conducted with low-passage (P2), investigating MTT viability during four days and adipogenic, chondrogenic and osteogenesis differentiation was induced in vitro. The most effective transport medium (p<0.1) was low glucose DMEM. There was no bacterial or fungal contamination from collection. Cells from Whartons jelly of ovine umbilical cords collected at natural birth possess fibroblastic morphology and the capacity for in vitro differentiation into adipogenic, chondrogenic and osteogenic cell lines. MTT tests and in vitro differentiation experiments revealed that cell culture medium modulates the behavior of cells and is an important factor for proliferation and maintenance of multipotency. Low glucose DMEM was the most suitable medium for the isolation of cells from Whartons jelly of ovine umbilical cord.