Evaluation of different cryoprotectant solutions for the cryopreservation of somatic tissues of Dasyprocta leporina (Linnaeus, 1758).

BACKGROUND: Somatic tissue banks represent important tools for the conservation of wild mammals, aiming at the immediate maintenance and safeguarding of biological samples. For agouti, Dasyprocta leporina, studies on the formation of these banks are still scarce, especially regarding protocols of the best cryoprotectant solution employed. OBJECTIVE: To optimize the cryoprotectant solution [ethylene glycol (EG), dimethyl sulfoxide (DMSO), sucrose (SUC)] used for the cryopreservation of agouti somatic tissues. MATERIALS AND METHODS: We treated ear tissues with various cryoprotectant solutions: 3.0 M EG (EG group), 3.0 M EG and 0.25 M SUC (EG-SUC group), 3.0 M DMSO (DMSO group), 3.0 M DMSO and 0.25 M SUC (DMSO-SUC group), 1.5 M EG and 1.5 M DMSO (EG-DMSO group) and 1.5 M EG, 1.5 M DMSO and 0.25 M SUC (EG-DMSO-SUC group). Non-cryopreserved tissues were used as controls. All tissues were analyzed for their ultrastructural and morphometric characteristics by scanning electron microscopy and conventional histology. RESULTS: EG-DMSO-SUC was found to be the optimal cryoprotectant solution in terms of the evaluated parameters, such as thickness of the dermis and skin, number of perinuclear halos, proliferative potential, number of empty lacunas and degenerated chondrocytes. CONCLUSION: Agouti somatic tissue cryopreservation may serve for its conservation and as an experimental model for the development of preservation methods for species of the same genus that are either vulnerable or critically endangered.

Antibiofilm effect of cleaning agents for ocular prostheses.

Introduction: This study aimed to evaluate the antibiofilm effect of different agents (neutral soap, 4% chlorhexidine, Efferdent effervescent tablets, 1% triclosan, and citronella essential oil) used for ocular prosthesis cleaning. Material and Methods: Biofilms of S. aureus and S. epidermidis were formed on 60 ocular prosthesis acrylic resin specimens. The specimens were cleaned with the studied agents with different techniques. Microorganism counting was performed. Data were submitted to ANOVA and HSD Tukey-Kramer (p<.01). Results: When compared to the control group, all cleaning protocols promoted a reduction in growth of microorganisms. The 4% chlorhexidine, effervescent tablets, and 1% triclosan cleaning agents eliminated biofilm in all groups. Conclusion: Therefore, immersion in 4% chlorhexidine, effervescent tablets, and 1% triclosan could be the best protocols indicated for ocular prosthesis cleaning due to their ability to eliminate biofilm.

Transplacental Transmission of Ovine Herpesvirus 2 in Cattle with Sheep-associated Malignant Catarrhal Fever.

Sheep-associated malignant catarrhal fever (SA-MCF) is an important infectious disease of ruminants worldwide that is caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is transmitted predominantly by contact between infected and susceptible hosts, while the documentation of vertical transmission is rare. This report presents the pathological and molecular findings associated with transplacental transmission of OvHV-2 in cattle. Two Girolanda cows with corneal oedema, lethargy, mucopurulent nasal discharge and ulcerative stomatitis died spontaneously; one of these was pregnant with a 4-month-old fetus. Significant pathological findings included widespread lymphoplasmacytic necrotizing vasculitis and lymphoplasmacytic accumulations in several organs of both cows and the fetus. A polymerase chain reaction that targeted the tegument protein gene of OvHV-2 amplified viral DNA from the brain of the pregnant cow and her fetus, as well as from the kidney of the pregnant cow. The pathological findings observed in the cow and her fetus, together with the presence of OvHV-2 DNA in tissues of these animals, are suggestive of transplacental transmission of OvHV-2 in SA-MCF in cattle.

Metabolic effects and distribution space of flufenamic acid in the isolated perfused rat liver.

The following aspects were investigated in the present work: (a) the action of flufenamic acid on hepatic metabolism (oxygen uptake, glycolysis, gluconeogenesis, uricogenesis and glycogenolysis), (b) the action of flufenamic acid on the cellular adenine nucleotide levels, and (c) the transport and distribution space of flufenamic acid in the liver parenchyma. The experimental system was the isolated perfused rat liver. Perfusion was accomplished in an open, non-recirculating system. The perfusion fluid was Krebs/Henseleit-bicarbonate buffer (pH 7.4), saturated with a mixture of oxygen and carbon dioxide (95:5) by means of a membrane oxygenator and heated to 37 degrees C. The distribution space of flufenamic acid was measured by means of the multiple-indicator dilution technique with constant infusion (step input) of [3H]water plus flufenamic acid. The results of the present work indicate that the metabolic effects of flufenamic acid are the consequence of an uncoupling of oxidative phosphorylation, a conclusion based on the following observations: (a) flufenamic acid increased oxygen uptake, a common property of all uncouplers; (b) the drug also increased glycolysis and glycogenolysis in livers from fed rats (these are expected compensatory phenomena for the decreased mitochondrial ATP formation); (c) flufenamic acid inhibited glucose production from fructose, an energy-dependent process; (d) the cellular ATP levels were decreased by flufenamic acid whereas the AMP levels were increased; and (e) the total adenine nucleotide content was decreased by flufenamic acid and uric acid production was stimulated. Indicator-dilution experiments with flufenamic acid revealed that this substance undergoes flow-limited distribution in the liver and that its apparent distribution space greatly exceeds the aqueous space of the liver. Flufenamic acid changed its behaviour when the portal concentration was increased from 25 to 50 microM. At 25 microM the initial upslope of the outflow profile clearly preceded that of all other concentrations. From the trend of the curves obtained with 50, 100 and 250 microM, one would expect an initial upslope situated at the right of the 50-microM curve. Furthermore, the time of appearance of flufenamic acid in the outflowing perfusate was practically the same irrespective of the portal concentration. For theoretical reasons one would expect progressively longer appearance times when the portal concentration was decreased. It is possible that the amount of flufenamic acid bound to the cell membranes during the early stages of the infusion produced changes that enabled these structures to bind a larger quantity of the drug than originally possible.