Translocated dogs from Nunavut and the spread of rabies.

BACKGROUND: Investigations of rabid animals that cross provincial/territorial boundaries are resource intensive and complex because of their multi-jurisdictional and multi-sectoral nature. OBJECTIVE: To describe the multi-jurisdictional responses to two unrelated rabid puppies originating from Nunavut. METHODS: A descriptive summary of the investigations following the identification of a rabid puppy in Alberta (August 2013) and another in Saskatchewan (December 2014). RESULTS: These investigations involved public health and agriculture authorities in five provinces/territories, as well as the Canadian Food Inspection Agency (CFIA). In Alberta, a puppy who became ill after being transported by air from Nunavut was euthanized and diagnosed with rabies (Arctic fox variant). Eighteen individuals were assessed for exposure to rabies; nine received rabies post-exposure prophylaxis (RPEP). An exposed household dog that tested negative was electively euthanized. In Nunavut, the rabid puppy's mother and litter mates were placed under quarantine. In Saskatchewan, another puppy became ill during transit by air from Nunavut. It was subsequently euthanized and diagnosed with rabies (Arctic fox variant). Two of three Saskatchewan individuals, including a veterinary technician, received RPEP. Two Nova Scotia residents were exposed to the puppy while in Nunavut and received RPEP. One household dog received booster vaccination, was quarantined for 45 days and remained asymptomatic. In Nunavut, the rabid puppy's mother and litter mates were not identified. In both cases, exposure to an Arctic fox was the probable source of rabies in the puppies. CONCLUSION: Translocation of dogs from the north where Arctic fox rabies is endemic poses a risk to human and animal health and may negatively impact control of rabies in Canada. There is currently no national framework to prevent inter-jurisdictional movement of potentially rabid animals in Canada.

Equine eosinophilic enterocolitis.

A 4-year-old Morgan stallion was presented with a 9-week history of diarrhea. Biopsy of nodules in the rectal mucosa yielded a diagnosis of eosinophilic enterocolitis. Treatment with steroids was instituted and the feces firmed within 2 days. Continued treatment with oral prednisone kept the feces at a normal consistency for 4 months.

[Functional studies of mutant forms of bacteriophage T7 RNA polymerases containing point substitutions in the motif at the active site of the enzyme]. / Funktsional'nye issledovaniia mutantnykh form RNK-polimerazy bakteriofaga T7, soderzhashchikh tochechnye zameny v motive v aktivnogo tsentra fermenta.

Monomeric DNA and RNA polymerases contain a number of conserved motifs. By means of random and oligonucleotide-directed mutagenesis the point mutants of bacteriophage T7 RNA polymerase containing the amino acid substitutions in motif B which is the part of the active site were obtained. The kinetic properties of the mutants were studied. The results obtained suggest that amino acid residues 636, 639 and 646 are involved in the binding of the initiating GTP, the selection of correct nucleoside triphosphate and interaction with the promoter, respectively.

[Genetic system of selecting point mutations of bacteriophage T7 RNA polymerase]. / Geneticheskaia sistema otbora tochechnykh mutantov RNK-polimerazy bakteriofaga T7.

Random mutagenesis of the bacteriophage T7 gene 1 was used to delineate the functionally important amino acids residues of its product--T7 RNA polymerase. A two-plasmid system has been constructed for the phenotypic selection of the mutants. Nine mutants were isolated; the RNA polymerase with Tyr-639----Asp substitution has been shown to be completely inactive. Methods were developed for the rapid purification of plasmid-encoded mutant proteins, facilitating their future biochemical analysis.

[Reverse transcriptase of the human immunodeficiency virus: cloning, expression in Escherichia coli, purification of the enzyme, and production of monoclonal antibodies]. / Obratnaia transkriptaza virusa immunodefitsita cheloveka: klonirovanie, ékspressiia v Escherichia coli, ochistka fermenta i poluchenie monoklonal'nykh antitel.

To express HIV-1 reverse transcriptase in E. coli a number of genetic constructions containing reverse transcriptase and virus protease nucleotide sequences was obtained. The products of expression were characterized; monoclonal antibodies to reverse transcriptase were produced. The purification of reverse transcriptase was carried out. The substantial proteolysis of reverse transcriptase during purification was shown. The purified preparation is predominantly, an active protein with Mr 57 kDa. Some properties of this protein differed from the reverse transcriptase isolated from HIV.

[Preparation and characteristics of monoclonal antibodies to DNA-dependent RNA-polymerase of bacteriophage T7]. / Poluchenie i kharakteristiki monoklonal'nykh antitel k DNK- zavisimoi RNK-polimeraze bakteriofaga T7.

The monoclonal antibodies to DNA-dependent RNA-polymerase of bacteriophage T7 have been obtained. Twenty of the obtained 500 clones have inhibited the enzyme activity. Three specificity groups were identified for seven of the clones supporting their affinity for different antigenic determinants.

Controls of ventricular contractility assessed by pressure-volume ration, Emax.

The present study on canine left ventricles showed that Emax which we previously proposed as a good index of both ventricular contractility and its pumping capability, decreased from 2.06 to 1.38 kPa/ml (15.5 to 10.4 mmHg/ml) via the sino-aortic baroreceptor reflex. Cerebral ischaemic response increased Emax to 3.83 kPa/ml (28.8 mmHg/ml). Emax decreased to 1.17 kPa/ml (8.8 mmHg/ml) after cardiac denervation.

Modification of the flow-generating capability of the canine heart-lung compartment by the carotid sinus baroreceptor reflex.

To quantitatively understand how the carotid sinus baroreceptor reflex modifies the Starling curve (i.e., the aortic flow (AF)-mean right atrial pressure (MRAP) relationship), experiments were performed in closed-chest, naturally breathing, and anesthetized dogs before and after vagotomy. Mean aortic pressure (MAP) was fixed at approximately 100 mm Hg and the pressure in the isolated carotid sinus (ISP) was varied from 75 to 150 mm Hg in steps of 25 mm Hg. At each ISP, MRAP was slowly increased and decreased while measuring AF by a previously implanted electromagnetic flow probe. A family of AF-MRAP relation curves specified at the different ISP's were thus obtained. Third-order polynomials in MRAP and ISP adequately fit these curves. Whether the vagi were intact or cut, there was no significant difference between the AF-MRAP relation curves obtained at an ISP of 75 or 100 mm Hg. However, decreasing ISP from 125 to 100 mm Hg caused a 24% increase in AF, and increasing ISP to 150 mm Hg caused a 15% decrease in AF in the dogs with intact vagus nerves. For the vagotomized dogs, the same decrease or increase in ISP caused a 17% increase or a 21% decrease in AF, respectively. When MAP was allowed to change by the reflex, only insignificant changes in AF occurred. We conclude that the carotid sinus reflex significantly alters the flow-generating ability of the heart-lung compartment by as much as 40% but this becomes clearly observable only if the reflex change in aortic pressure is prevented.