Transthoracic echocardiographic guidance of patent ductus arteriosus occlusion with an Amplatz® canine duct occluder.

Placement of an Amplatz canine duct occluder (ACDO) is usually performed by fluoroscopy (Nguyenba and Tobias, 2007). The latter technical approach presents limitations, mostly due to radiation exposure, making this practice dangerous for the patient and operators. In this study, we describe the successful placement of an Amplatz Canine Duct Occluder device by using transthoracic echocardiographic (TTE) guidance, performed on an 11-month-old female mongrel dog with a grade VI/VI continuous heart murmur diagnosed with patent ductus arteriosus (PDA). The TTE is useful in eliminating exposure to radiation and is more versatile than fluoroscopy in conveying real-time detailed information concerning the position of the ACDO.

Experimental posterolateral spinal fusion with porous ceramics and mesenchymal stem cells.

Alternatives to autogenous bone graft for spinal fusion have been investigated for many years. It has been shown that osteoconductive materials alone do not give a rate of fusion which is comparable to that of autogenous bone graft. We analysed the effectiveness of porous ceramic loaded with cultured mesenchymal stem cells as a new graft material for spinal fusion in an animal model. Posterolateral fusion was carried out at the L4/L5 level in 40 White New Zealand rabbits using one of the following graft materials: porous ceramic granules plus cultured mesenchymal stem cells (group I); ceramic granules plus fresh autogenous bone marrow (group II); ceramic granules alone (group II); and autogenous bone graft (group IV). The animals were killed eight weeks after surgery and the spines were evaluated radiographically, by a manual palpation test and by histological analysis. The rate of fusion was significantly higher in group I compared with group III and higher, but not significantly, in group I compared with groups II and IV. In group I histological analysis showed newly formed bone in contact with the implanted granules and highly cellular bone marrow between the newly formed trabecular bone. In group II, thin trabeculae of newly formed bone were present in the peripheral portion of the fusion mass. In group III, there was a reduced amount of newly formed bone and abundant fibrous tissue. In group IV, there were thin trabeculae of newly formed bone close to the decorticated transverse processes and dead trabecular bone in the central portion of the fusion mass. In vitro cultured mesenchymal stem cells may be loaded into porous ceramic to make a graft material for spinal fusion which appears to be more effective than porous ceramic alone. Further studies are needed to investigate the medium- to long-term results of this procedure, its feasibility in the clinical setting and the most appropriate carrier for mesenchymal stem cells.

[Experimental infection with Salmonella abortus ovis in rams]. / Infection expérimentale du bélier par Salmonella abortus ovis.

The susceptibility of rams to experimental challenge with Salmonella abortus ovis was investigated by subcutaneous, conjunctival or preputial administration of 1 X 10(10) viable salmonella to 3 groups of 6 adult Préalpes rams. Slaughter and autopsy of 15 rams were made 83 days after challenge. Each of the 3 remaining rams was introduced in 3 groups of 6 salmonellosis-free ewes. The subcutaneous injection caused a significant hyperthermia, a rapid increase in antibody titers without detectable genital excretion of salmonella. The conjunctival or preputial challenge caused a significant serological response without fever; S. abortus ovis was isolated from samples taken 1 to 13 days after challenge only in rams challenged by the preputial route. No salmonella was isolated from organs of the 15 slaughtered rams. Ewes made pregnant by the 3 remaining rams showed no signs of infection. In our experimental conditions, a genital colonization was not observed; a passive genital carriage of S. abortus ovis was shown to be possible; its hypothetical epidemiological role was discussed.