Field comparison of the interferon-gamma assay and the intradermal tuberculin test for the diagnosis of bovine tuberculosis

An extensive field comparison of the gamma interferon (IFN-gamma) assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis was conducted in Australia. The specificity of the IFN-gamma assay was determined by testing more than 6000 cattle from tuberculosis-free herds and varied from 96.2% to 98.1%, depending on the cut-off point chosen to define a positive reactor. For the sensitivity trial, cattle from herds being de-populated because of bovine tuberculosis were examined with both assays. The sensitivity of the IFN-gamma assay was shown to be significantly higher than the single intradermal tuberculin test and varied from 76.8% to 93.6% depending on the method of interpretation. A maximum overall sensitivity of 95.2% was obtained by testing with the IFN-gamma and the tuberculin test in parallel. The superior sensitivity of the IFN-gamma assay and the ability to adjust the sensitivity of the system depending on the task involved, will provide the Australian Tuberculosis Eradication Campaign with a valuable additional test to enable it to accomplish its goals.     

The Effect of Plate Luting on Reduction Accuracy and Biomechanics of Acetabular Osteotomies Stabilized With 2.7-mm Reconstruction Plates

OBJECTIVE: To compare the accuracy of reduction and biomechanical characteristics of acetabular osteotomies repaired with luted and nonluted reconstruction plates. STUDY DESIGN: In vitro study. ANIMALS: Pelves removed from 12 adult greyhounds. METHODS: Acetabular osteotomies were created and repaired with a 6-hole, 2.7-mm reconstruction plates in 24 cadaver hemipelves. Ten hemipelves each were assigned to group I and group II. An impression cast of each acetabulum in group I was made before luting (preluting cast). Group I plates were then elevated, luted, and replaced. A second cast of each acetabulum in group I was then made (postluting cast). Step, gap, and total areas of articular osteotomy incongruence were determined from the casts. Group I (luted plate repairs) and group II (nonluted plate repairs) hemipelves were loaded ventral-to-dorsal using a materials-testing machine. Stiffness, yield load, and maximal load sustained were determined. RESULTS: Mean gap and total area of articular osteotomy incongruence for group I preluted plate repairs (7.1 mm(2) and 8.6 mm(2), respectively) were significantly greater than for group I postluted plate repairs (4.1 mm(2) and 5.1 mm(2), respectively). Mean stiffness and maximal load for group I (681 N/mm and 2,555 N, respectively) were significantly greater than for group II (360 N/mm and 1,730 N, respectively). Mean step area and mean load at yield values were not significantly different between groups. CONCLUSIONS: Luted plate repairs of osteotomized acetabulae result in improved reduction and are stiffer and stronger than nonluted plate repairs. CLINICAL SIGNIFICANCE: Plate luting may improve the accuracy of reduction of acetabular fractures where anatomic reduction is required. Plate luting may also increase the stiffness and strength of fracture repairs and arthrodeses.     

Survey of the seroprevalence of brucellosis in ruminants in Tajikistan

A cross-sectional serological survey of the prevalence of brucellosis in ruminants in the Region of Republican Subordination and Khatlon oblasts (provinces) in Tajikistan was conducted in May 2003. Sera from 13,625 ruminants involving 3513 households in 172 kishlaks (villages) were collected and screened by the rose bengal test. Doubtful and positive results were further tested with competitive and indirect elisas. The overall serological prevalences (95 per cent confidence intervals [cis]) were 5.8 per cent (5.2 to 6.4 per cent) for sheep, 5.5 per cent (5.0 to 6.0 per cent) for goats and 2.1 per cent (1.0 to 3.2 per cent) for cattle. The results show that brucellosis was a common disease of ruminants that was widely but unevenly distributed throughout the two oblasts. Seropositive animals were found in 119 of the 172 kishlaks (69.2 per cent [95 per cent ci 61.9 to 75.6 per cent]) and 14.4 per cent (95 per cent ci 13.3 to 15.6 per cent) of the 3513 households. Evidence of infection was also found in cattle kept for milk production in urban kishlaks in two major cities and in state-owned dairy farms.     

Effect of 9 mm tibial tuberosity advancement on cranial tibial translation in the canine cranial cruciate ligament-deficient stifle

Objective— To assess the effect of 9 mm tibial tuberosity advancement (TTA) on cranial tibial translation (CTT) in a cranial cruciate ligament (CCL)-deficient canine stifle model.
Study Design— In vitro cadaveric study.
Animals— Canine pelvic limbs (n=12).
Methods— Each stifle was placed in a jig at 135° with a simulated quadriceps force and tibial axial force. CTT distance was measured with the CCL intact (iCCL), transected (tCCL), and after performing TTA using a 9 mm cage.
Results— Mean CTT for iCCL was 0.42 mm, 1.58 mm after severing the CCL, and 1.06 mm post-TTA. The tCCL CTT measured without any quadriceps force was 2.59 mm. Differences between the intact and tCCL ( P <.0001) and tCCL and TTA ( P =.0003) were significant. The difference between the tCCL with and without the quadriceps force was not significant ( P =.0597).
Conclusions— These data confirm that TTA does reduce CTT in tCCL stifles in this model. The CTT noted was less than that noted clinically. The addition of a simulated quadriceps force to a CCL-deficient stifle before a TTA, by itself, may not significantly lessen CTT.
Clinical Relevance— Whereas this in vitro model demonstrated that TTA reduced CTT in canine stifles with CCL transected, the model limitations preclude extrapolation to the effect of TTA in a live dog.     

Changes in platelet function, hemostasis, and prostaglandin expression after treatment with nonsteroidal anti-inflammatory drugs with various cyclooxygenase selectivities in dogs

OBJECTIVE: To determine the effects of nonsteroidal anti-inflammatory drugs of various cyclooxygenase selectivities on hemostasis and prostaglandin expression in dogs. ANIMALS: 8 client-owned dogs with clinical signs of osteoarthritis. PROCEDURES: Dogs received aspirin (5 mg/kg, PO, q 12 h), carprofen (4 mg/kg, PO, q 24 h), deracoxib (2 mg/kg, PO, q 24 h), and meloxicam (0.1 mg/kg, PO, q 24 h) for 10 days each, with an interval of at least 14 days between treatments. On days 0 and 10, blood was collected for platelet aggregation assays, thrombelastography, and measurement of lipopolysaccharide-stimulated prostaglandin E(2), platelet thromboxane B(2) (TXB(2)), and free serum TXB(2) and 6-keto-prostaglandin F (PGF)-1alpha concentrations. RESULTS: Platelet aggregation decreased after treatment with aspirin and carprofen, whereas significant changes from baseline were not detected for the other drugs tested. Thrombelastograms obtained after treatment with carprofen revealed decreased maximum amplitude and alpha-angle, suggesting hypocoagulability. Maximum amplitude and coagulation index increased after treatment with deracoxib. Plasma concentrations of prostaglandin E(2) decreased after treatment with carprofen or deracoxib, and platelet TXB(2) production increased after treatment with aspirin. Serum concentrations of the prostacyclin metabolite 6-keto-PGF-1alpha did not change significantly after treatment with any of the drugs, although the ratio of free TXB(2) to 6-keto-PGF-1alpha decreased slightly after treatment with carprofen and increased slightly after treatment with deracoxib. CONCLUSIONS AND CLINICAL RELEVANCE: At the dosages tested, treatment with meloxicam affected platelet function minimally in dogs with osteoarthritis. Treatment with carprofen decreased clot strength and platelet aggregation. Clot strength was increased after treatment with deracoxib.     

The use of vacuum-assisted closure therapy for the treatment of distal extremity wounds in 15 dogs

Objective— To evaluate clinical outcome after vacuum-assisted closure (VAC) therapy in dogs with traumatic wounds located in the distal extremities and report our early experience with VAC.
Study Design— Retrospective study.
Animals— Dogs (n=15) with traumatic distal extremity wounds.
Methods— Medical records (1999–2003) of dogs with traumatic injuries to the distal extremities managed by VAC were evaluated. Data included signalment, location of wound, time until surgical intervention, wound reconstruction methods, orthopedic procedures, outcome, complications associated with VAC, and length of hospitalization.
Results— The mean number of days until reconstruction was 4.6 days (range, 2–7 days). Reconstructive surgery was successful in all cases. Mean hospitalization was 9.7 days (range, 6–16 days). Complications included dermatitis at the wound margin and loss of vacuum causing wound desiccation.
Conclusion— VAC therapy can be used to achieve adequate management of traumatic distal extremity wounds. VAC provides an effective method of securing skin grafts over the wound bed.
Clinical Relevance— VAC therapy can be used as an ancillary treatment for distal extremity wounds in dogs before surgical repair as well as a method for securing skin grafts to the wound bed.     

Floral acoustics: conspicuous echoes of a dish-shaped leaf attract bat pollinators

The visual splendor of many diurnal flowers serves to attract visually guided pollinators such as bees and birds, but it remains to be seen whether bat-pollinated flowers have evolved analogous echo-acoustic signals to lure their echolocating pollinators. Here, we demonstrate how an unusual dish-shaped leaf displayed above the inflorescences of the vine Marcgravia evenia attracts bat pollinators. Specifically, this leaf's echoes fulfilled requirements for an effective beacon, that is, they were strong, multidirectional, and had a recognizable invariant echo signature. In behavioral experiments, presence of the leaves halved foraging time for flower-visiting bats.