The effect of low level laser therapy (LLLT) on wound healing in horses.

Laser therapy is used in many countries, including South Africa, for the treatment of skin wounds. Low level galium aluminium arsenide (GaAlAs) laser was administered to full thickness skin wounds (3 x 3 cm) induced surgically on the dorsal aspect of the metacarpophalangeal joints of 6 crossbred horses in a randomised, blind, controlled study. Treated wounds that received a daily laser dosage of 2 J/cm2 were compared with nontreated control wounds on the opposite leg. There were no wound complications. Both groups of wounds were cleaned daily using tap water. Wound contraction and epithelialisation were evaluated using photoplanimetry. There were no significant differences in wound contraction or epithelialisation between the laser treated and the control wounds. It was therefore concluded that laser therapy had no clinically significant effect on second intention wound healing in this study.     

Simultaneous evaluation of spatial working memory and motivation by the allocentric place discrimination task in the water maze in rats.

In order to evaluate learning and memory deficits separately from and simultaneously with motivational, motor and sensory impairments in identical animals, we developed the allocentric place discrimination task test using a water maze in rats. For this assessment task, two similar, visible platforms, one was fixed and the other was floating, were simultaneously present in a pool, and the working memory of the allocentric place discrimination task was evaluated. After training, the task accuracy was high about 85% correct and animals were used repeatedly. The accuracy decreased significantly when the pool was surrounded with a black curtain. Muscarinic receptor antagonist scopolamine 0.5 mg/kg selectively impaired the accuracy. Muscle relaxant dantrolene 10 mg/kg selectively decreased swimming speed. Under low motivational condition (warm water), still time increased and swimming speed decreased, but the accuracy was not affected. Similar to warm water, opioid receptor agonist morphine 15 mg/kg increased still time and decreased swimming speed. These results suggest that the allocentric place discrimination task is useful in evaluating spatial working memory ability independently of and concurrently with also visual, motor ability and motivation in identical animals.     

Cloning and mapping of three pig acyl-CoA dehydrogenase genes.

To investigate the structure of porcine genes involved in the beta-oxidation of fatty acid, we isolated the short-chain acyl-CoA dehydrogenase (SCAD), medium-chain acyl-CoA dehydrogenase (MCAD), and long-chain acyl-CoA dehydrogenase (LCAD) genes from the pig. The cDNA of SCAD, MCAD and LCAD genes were 1899 bp, 1835 bp 1835 bp and 1704 bp long and coded for 413-aa, 422-aa and 430-aa precursor proteins, respectively. Three genes, SCAD, MCAD and LCAD were mapped to 14p16.2-23.2, 6q32.4-33, and 15q24.2-26.3, respectively.     

Effect of more stringent convergence criterion of estimated breeding values on response to selection

In the analysis of large amounts of data to obtain BLUP, large sets of mixed model equations must be solved iteratively, which can involve considerable computing time. In real life, solutions are required only periodically for breeders to choose the best individuals, so that computing time is not usually a limiting factor. In simulation studies involving evaluation of individuals by BLUP, many rounds of evaluation are required for each simulated population. Since several or many replicates are usually required to obtain an accurate result from stochastic simulations, computing time can become a limiting factor. One of the factors that can drastically affect computing time in iterative methods is the criterion for ceasing iteration, or convergence criterion (CC). With iterative methods, a disadvantage can be that the rate of convergence can be slow, or under certain circumstances not converge at all. Nevertheless, when the system converges, the more stringent the CC, the more accurate the solutions. The more stringent the CC the more iterations and hence more computing time is required. The objectives of this study were to investigate how much response to selection is affected by the stringency of the CC and how much reranking occurs among selected individuals at different levels of the convergence criteria. These explorations provided a profile analysis of the computing time spent for each of the major subroutines in the BBSIM program.     

Bone grafts.

Bone grafting provides a method of enhancing bone healing in veterinary orthopedic patients. Specifically, autogenous cancellous bone graft provides the cellular components and matrix proteins that can accelerate bone healing, dramatically. Allografts provide immediate mechanical support for fracture repair and patient function, but these grafts do not create the osteogenic environment seen with the use of autogenous cancellous bone graft. Xenograft bone implants may also hold a place for use in fracture management. With the advent of recombinant bone-derived tissue growth factor technology, bone grafting may some day become a practiced technique of the past. For now, however, bone grafting still holds a strong place in orthopedic surgery when dealing with bone defects in animals.     

Tilapia (Oreochromis niloticus) dosed with azathioprine display immune effects similar to those seen in mammals, including apoptosis.

Azathioprine, an anti-neoplastic drug and therapeutic immunosuppressant, was administered intraperitoneally at 10.0 and 50.0 mg/kg to 3-6-month-old tilapia (Oreochromis niloticus). Consistent alterations in immune cellular parameters of the blood, pronephros (hematopoietic kidney) and spleen were observed. Peripheral blood total cellularity decreased as the azathioprine dose increased, to approximately half that of the control. Differential analysis of white blood cells indicated a decline in lymphocyte number, in particular, with increased dosage of azathioprine. Pronephric total cellularity was depressed in fish receiving the 10.0 or 50.0 mg/kg dose. In contrast, both splenic weight and splenic total cellularity increased proportionately with the increase in the drug dosage. Histopathologic examination of the spleens showed normal patterns for both control and 10.0 mg/kg dose groups. At 50.0 mg/kg, spleens were characterized by marked expansion of the white pulp, although lymphocytes were rare. Melanomacrophage centers at the higher dose were also larger and more numerous than in the control group. Evaluation of splenic and pronephric leukocytes with apoptotic markers showed an increase in apoptotic cells in the pronephros with increasing drug dose. These changes in fish are consistent with those seen in humans and laboratory rodents dosed with azathioprine, suggesting that fish may be potentially useful as preliminary models for detecting immunosuppressive compounds.     

Evaluation in Rabbits of the Fetal Effects of Maternal Ingestion of Solanum malacoxylon

A study was performed to determine the possible toxic effects on the young of does that had been fed during the gestational period on a ration containing Solanum malacoxylon (Sm), a calcinogenic plant that contains a vitamin D₃-glycoside conjugate. Experimental animals received a ration containing 0.03% or 0.04% of Sm leaves on days 6 to 30 of gestation. The levels of calcium, phosphorus and alkaline phosphatase in their sera, as well as their feed intake and body weight, were evaluated weekly. The does were euthanized 3 days after parturition and paraffin sections stained with haematoxylin and eosin were prepared from their heart, lungs, kidneys and aorta for histopathological examination. The young from does in the Sm 0.03% group were euthanized 3 days after birth and biochemical and histopathological determinations were performed, as described for the does. The does in both experimental groups showed decreased feed consumption and those in the Sm 0.04% group showed lower body weights throughout their gestation. Animals treated with Sm 0.04% presented a high incidence of abortion and stillbirth. There were biochemical and histopathological alterations in both experimental groups, which were more prominent in the does in the Sm 0.04% group. Litters from does treated with Sm 0.03% showed mineralization of soft tissue and an increase in phosphorus and calcium levels. These findings indicate that the vitamin D₃-glycoside passes through the placental barrier to the fetus.     

Behavior of a Virulent Strain Derived from Agrobacterium radiobacter Strain K84 After Spontaneous Ti Plasmid Acquisition

ABSTRACT The behavior of the virulent transconjugant K84N6 derived from Agrobacterium radiobacter strain K84 after spontaneous Ti plasmid transfer in crown gall tissue in a biocontrol experiment was studied and compared with the behavior of the wild-type A. tumefaciens donor of the Ti plasmid. The main difference between the strains was a greatly reduced ability of the transconjugant to catabolize nopaline. Host range, ability to induce tumors in several fruit trees, and stability of the pathogenic determinants in isolates from tumors did not differ between the strains. Nevertheless, in a biocontrol experiment, the transconjugant was not controlled by strain K84 or K1026 in peach x almond hybrids and survived in the plant rhizo-sphere for 9 months with larger population densities than the wild strain. The appearance and persistence in soil of strains harboring a Ti plasmid in the K84 chromosomal background could represent a risk in the medium term, if they show good competitive ability.