Objective-To assess the effects of oxygen insufflation rate, respiratory rate, and tidal volume on fraction of inspired oxygen (Fio2) in cadaveric canine heads attached to a lung model. Sample-16 heads of canine cadavers. Procedures-Each cadaver head was instrumented with a nasal insufflation catheter through which oxygen was delivered. The trachea was attached to a sample collection port connected by means of corrugated tubing to a lung model. Eight treatment combinations that varied in respiratory rate (10 or 20 breaths/min), tidal volume (10 or 15 mL/kg), and oxygen insufflation rate (50 or 100 mL/kg/min) were applied to each head in a replicated Latin square design. Gas samples were manually collected, and inspired oxygen concentrations were analyzed. The Fio2 and end-tidal CO2 concentration were determined and compared among sample groups. Results-Estimated least squares mean Fio2 for various treatment combinations ranged from 32.2% to 60.6%. The Fio2 was significantly increased at the higher insufflation rate (estimated marginal least squares mean, 48.7% vs 38.6% for 100 and 50 mL/kg/min, respectively), lower respiratory rate (48.9% vs 38.3% for 10 and 20 breaths/min, respectively), and smaller tidal volume (46.8% vs 40.0% for 10 and 15 mL/kg, respectively). Conclusions and Clinical Relevance-Fio2 in the model was affected by oxygen insufflation rate, respiratory rate, and tidal volume. This information may potentially help clinicians interpret results of blood gas analysis and manage canine patients receiving oxygen insufflation via a nasal catheter.

Objective: To determine the effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers. Animals: 20 heifers (mean body weight, 217.8 kg). Procedures: Ten heifers were transported 518 km when the maximum ambient temperature was ≥ 32.2°C while the other 10 heifers served as untransported controls. Blood samples were collected from transported heifers at predetermined intervals during the transportation period. For all heifers, body weights, nasal and rectal temperatures, and behavioral indices were measured at predetermined intervals for 3 days after transportation. A week later, the entire process was repeated such that each group was transported twice and served as the control twice. Results: Transported heifers spent more time near the hay feeder on the day of transportation, had lower nasal and rectal temperatures for 24 hours after transportation, and spent more time lying down for 2 days after transportation, compared with those indices for control heifers. Eight hours after transportation, the weight of transported heifers decreased 6%, whereas that of control heifers increased 0.6%. At 48 hours after initiation of transportation, weight, rectal temperature, and time spent at various pen locations did not differ between transported and control heifers. Cortisol concentrations were higher 4 hours after initiation of transportation, compared with those determined just prior to transportation. Conclusions and Clinical Relevance: Results indicated transportation during periods of high ambient temperatures caused transient changes in physiologic and behavioral indices of beef heifers.

Objective: To develop an orthotopic model of canine osteosarcoma in athymic rats as a model for evaluating the effects of stereotactic radiotherapy (SRT) on osteosarcoma cells. Animals: 26 athymic nude rats. Procedures: 3 experiments were performed. In the first 2 experiments, rats were injected with 1 × 10(6) Abrams canine osteosarcoma cells into the proximal aspect of the tibia (n = 12) or distal aspect of the femur (6). Tumor engraftment and progression were monitored weekly via radiography, luciferase imaging, and measurement of urine pyridinoline concentration for 5 weeks and histologic evaluation after euthanasia. In the third experiment, 8 rats underwent canine osteosarcoma cell injection into the distal aspect of the femur and SRT was administered to the affected area in three 12-Gy fractions delivered on consecutive days (total radiation dose, 36 Gy). Percentage tumor necrosis and urinary pyridinoline concentrations were used to assess local tumor control. The short-term effect of SRT on skin was also evaluated. Results: Tumors developed in 10 of 12 tibial sites and all 14 femoral sites. Administration of SRT to rats with femoral osteosarcoma was feasible and successful. Mean tumor necrosis of 95% was achieved histologically, and minimal adverse skin effects were observed. Conclusions and Clinical Relevance: The orthotopic model of canine osteosarcoma in rats developed in this study was suitable for evaluating the effects of local tumor control and can be used in future studies to evaluate optimization of SRT duration, dose, and fractionation schemes. The model could also allow evaluation of other treatments in combination with SRT, such as chemotherapy or bisphosphonate, radioprotectant, or parathyroid hormone treatment.

Objective—To characterize the dynamics of calcitonin secretion in response to experimentally induced hypercalcemia in cats. Animals—13 healthy adult European Shorthair cats.Procedures—For each cat, the calcitonin response to hypercalcemia (defined as an increase in ionized calcium concentration > 0.3mM) was investigated by infusing calcium chloride solution and measuring circulating calcitonin concentrations before infusion (baseline) and at various ionized calcium concentrations. Calcitonin expression in the thyroid glands of 10 of the cats was investigated by immunohistochemical analysis. Results—Preinfusion baseline plasma calcitonin concentrations were very low in many cats, sometimes less than the limit of detection of the assay. Cats had a heterogeneous calcitonin response to hypercalcemia. Calcitonin concentrations only increased in response to hypercalcemia in 6 of 13 cats; in those cats, the increase in calcitonin concentration was quite variable. In cats that responded to hypercalcemia, calcitonin concentration increased from 1.3 ± 0.3 pg/mL at baseline ionized calcium concentration to a maximum of 21.2 ± 8.4 pg/mL at an ionized calcium concentration of 1.60mM. Cats that did not respond to hypercalcemia had a flat calcitonin-to-ionized calcium concentration curve that was not modified by changes in ionized calcium concentration. A significant strong correlation (r = 0.813) was found between the number of calcitonin-positive cells in the thyroid gland and plasma calcitonin concentrations during hypercalcemia. Conclusions and Clinical Relevance—Healthy cats had very low baseline plasma calcitonin concentrations. A heterogeneous increase in plasma calcitonin concentration in response to hypercalcemia, which correlated with the expression of calcitonin-producing cells in the thyroid, was identified in cats.

The attenuated Salmonella typhimurium χ4550 strain was used to harbour a reconstructed bicistronic DNA vaccine against porcine rotavirus, which carried the rotavirus nonstructural protein 4 (NSP4) and VP7 genes simultaneously. Using a balanced lethal system, the kanamycin resistance gene of expressing eukaryotic plasmids pVAX1 and pVAXD were replaced by the aspartate β-semialdehyde dehydrogenase (asd) gene. The NSP4 cleavage product (259-525) of rotavirus OSU strain and VP7 full-length genes were amplified by reverse transcription polymerase chain reaction and then inserted into the eukaryotic single-expression plasmid, pVAX1-asd, and the eukaryotic dual-expression plasmid, pVAXD-asd, respectively. The recombinant plasmids pVAX1-asd-NSP4, pVAX1-asd-VP7 and pVAXD-asd-NSP4-VP7 were transformed into the attenuated S. typhimurium χ4550 strain by electrotransformation. An indirect immunofluorescence assay of the expressed COS-7 cell suggested that the recombinant S. typhimurium χ4550 strain was constructed successfully. The recombinant S. typhimurium χ4550 strain was orally administered to BALB/c mice. The group immunised with dual-expression plasmids produced a significantly higher level of serum Immunoglobulin G (IgG) and intestinal Immunoglobulin A (IgA) than the group immunised with single-expression plasmids. These results indicated that eukaryotic bicistronic plasmid DNA vaccines could be successfully constructed to enhance humoural, mucosal and cellular immune response against rotavirus infection.

The apxIC genes of the Actinobacillus pleuropneumoniae serovar 5 (SC-1), encoding the ApxI-activating proteins, was deleted by a method involving sucrose counter-selection. In this study, a mutant strain of A. pleuropneumoniae (SC-1) was constructed and named AapxIC/ ompP2. The mutant strain contained foreign DNA in the deletion site of ompP2 gene of Haemophilus parasuis. It showed no haemolytic activity and lower virulence of cytotoxicity in mice compared with the parent strain, and its safety and immunogenicity were also evaluated in mice. The LD50 data shown that the mutant strain was attenuated 30-fold, compared with the parent strain (LD50 of the mutant strain and parent strain in mice were determined to be 1.0 x 10(7) CFU and 3.5 x 10(5) CFU respectively). The mutant strain that was attenuated could secrete inactivated ApxIA RTX toxins with complete antigenicity and could be used as a candidate live vaccine strain against infections of A. pleuropneumoniae and H. parasuis.

The study aimed to determine the prevalence of peste des petits ruminants in the arid zone (Niamey, Tillabéry and Tahoua) of the Republic of Niger. A serological survey was conducted and 519 serum samples were collected from 253 unvaccinated sheep and 266 unvaccinated goats. The sample included 340 female animals (168 sheep and 172 goats) and 160 kids and lambs (78 lambs and 82 kids). A competitive enzyme-linked immunosorbent assay yielded an overall seroprevalence of 45.0%. The prevalence in sheep was 42.0% compared with 47.9% in goats. The seroprevalence observed amongst small ruminants in Tahoua (49.8%) and Tillabéry (46.6%) was significantly higher (p = 0.001) than that observed in animals from Niamey (25.1%). It was also higher (p = 0.04) in sheep younger than two years (51.8%) than in adults (37.6%). Conversely, the seroprevalence showed no significant difference between male animals (35.8% in sheep; 50.1% in goats) and female animals (45.1% in sheep; 46.4% in goats). The prevalence of the disease observed amongst the sheep and goat populations confirms the continued danger of this disease in the areas studied. It is therefore necessary to develop strategies such as improving livestock services, providing effective vaccines and implementing a vaccination programme for an effective control of the disease in sub-Saharan Africa.

A molecular study was undertaken to detect Theileria ovis, Theileria lestoquardi and Theileria annulata in sheep and tick vectors. Investigation was conducted from 2010 to 2011 in the south of Khorasan Razavi Province, Iran. A total of 150 blood samples were collected from 30 different sheep flocks. In addition, ixodid ticks were sampled from the same flocks. The stained blood smears were microscopically examined for the presence of piroplasms and a semi-nested polymerase chain reaction-restriction (PCR) was used for subsequent molecular speciation. Salivary glands were isolated from the ticks and subsequently analysed by semi-nested PCR. polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to differentiate between T. lestoquardi and T. annulata from PCR-positive samples. Theileria species infection was microscopically detected in 18.6% of blood smears. The presence of T. ovis and T. lestoquardi or T. annulata was detected by semi-nested PCR in 58.6% and 6.6% of blood samples respectively. In total, 169 ixodid ticks were collected from different areas of the province. The most prevalent ticks were Rhipicephalus turanicus (n = 155; 91.7% of the total), followed by Hyalomma anatolicum anatolicum (n = 8; 4.7%) and Hyalomma marginatum turanicum (n = 6; 3.5%). From an organ pooling of 33 ticks, three pools of salivary glands from R. turanicus were positive for Theileria species by semi-nested PCR. Of the three R. turanicus samples testing positive for Theileria species, two (6.1%) were positive for T. ovis and one (3.0%) for T. lestoquardi or T.annulata. Amongst the 11 PCR-positive samples for T. lestoquardi or T. annulata, 10 were positive for T. lestoquardi and one sample was positive for both T. lestoquardi and T. annulata using PCR-RFLP. The results also demonstrated that PCR-RFLP could be used for the detection of T. ovis. Based on the results, it can be concluded that T. ovis has a higher prevalence than T. lestoquardi, and that R. turanicus could be a possible vector for T. ovis and T. lestoquardi. Finally, the PCR-RFLP based on Msp1 restriction enzyme is a simple method for differentiation of Theileria species in sheep and ixodid ticks.

Peste des petits ruminants virus, which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Tanzania. An epidemiological study was carried out between September 2008 and October 2010 to investigate the incursion, persistence and spread of the virus in Tanzania. The investigation involved serosurveillance, outbreak investigation and computation of epidemiological indices such as the effective reproductive number, persistence and the threshold level for vaccination. Field and molecular epidemiological techniques were applied to isolate, characterise and trace the origin of the virus in Tanzania. A total of 2182 serum samples from goats and 1296 from sheep from 79 villages across 12 districts were investigated. Village-level prevalence of infection was variable (0.00% - 88.00%) and was higher in pastoral than in agro-pastoral villages. The overall antibody response to the virus was 22.10% (CI95% = 20.72% - 23.48%). About 68.00% and 73.00% of seropositive goats and sheep, respectively, did not show clinical signs. The proportion of seropositive animals differed significantly (p < 0.001) between age groups, sex and farming practices. Real-time polymerase chain reaction results showed that the isolated strains belong to lineage III, whose origin is in East Africa and the Middle East. This indicates that one of the northern neighbouring countries is most likely the source of infection. The computed overall effective reproductive number, the threshold level of vaccination necessary to eradicate the disease and persistence were 4.75% and 98.00%, respectively. These estimates indicate that achieving elimination of the peste des petits ruminants virus from pastoral flocks will require significant effort and development of highly effective intervention tools.

The distribution of interstitial cells of Cajal (ICC), the probable pacemakers in gastrointestinal motility, was investigated using an antigenic marker of gastric ICC known as C-Kit. Antiserum raised against the general neuronal marker protein gene peptide 9.5 (PGP) as well as the nitrergic neuronal marker neuronal nitric oxide synthase (nNOS) were used to investigate the distribution of gastric nerves. Polyclonal goat anti-human C-Kit was reliable in labelling ICC in the stomach. Two classes of ICC were identified according to their distribution: ICC-MY distributed around the periphery of myenteric ganglia and ICC-IM in the circular and longitudinal muscle layers. The neuronal marker PGP was reliably consistent in revealing the density and distribution of the enteric nervous system. Density of nerve fibres was higher in circular smooth muscle than in longitudinal smooth muscle. From nNOS immunohistochemistry, it is evident that inhibitory (nitrergic) nerves constitute a substantial fraction of the enteric nervous system.