Radiographic and functional evaluation of dogs at least 1 year after tibial plateau leveling osteotomy

The progression of osteoarthritis and clinical function in 29 dogs at least 1 year after tibial plateau leveling osteotomy was evaluated. A previously reported radiographic scoring system was used by 3 investigators to evaluate preoperative and postoperative radiographs for evidence of stifle osteoarthritis. The combined scores were then used to evaluate the progression of osteoarthritis. The difference between the preoperative scores, derived from radiographs taken at the time of surgery, and the postoperative scores based on radiographs taken at least 1 year later was modest but statistically significant. Despite this finding, client satisfaction was very good. Clinical function was assessed by using a previously reported client questionnaire. According to owner assessment at least 1 year after surgery, there was a significant improvement in function after tibial plateau leveling osteotomy when compared with the preoperative status. Improvement in function as measured by the client questionnaire did not significantly predict the radiographic osteoarthritis score.     

Fragment size is associated with post-operative complications following elective arthroscopy of the tibiotarsal joint of horses

The objective of this retrospective study was to determine the occurrence of joint-related complications after elective arthroscopy of the tibiotarsal joint (TTJ) in 329 horses, and the association with specific clinical parameters. Data were collected from medical records of horses undergoing elective tibiotarsal joint arthroscopy for fragment removal. Exact conditional univariate regression was used to determine significant risk factors for joint-related post-operative complications.Of 485 joints, 2 (0.4%) developed surgical site infection, 4 (0.8%) developed septic arthritis, 1 (0.2%) developed synovial fistula. There was a significantly increased odds of having septic arthritis as height and length of the distal intermediate ridge of the tibia (DIRT) lesion increased. The median height and length of the DIRT fragments in affected cases was 13.5 mm and 18.0 mm, respectively. For each unit (1 mm) increase in height, there was a 42% increase in the risk of septic arthritis occurrence (P = 0.0042), and a 15% increase for each unit increase in length (P = 0.035). Horses were significantly less likely to develop septic arthritis when suture smaller than USP 0 was used.Horses with larger osteochondritis dissecans lesions of the DIRT region have an increased risk of developing septic arthritis following fragment removal.     

Genetic analysis of the maximum germination distance of Striga under Fusarium oxysporum f. sp. strigae biocontrol in sorghum

Maximum germination distance(MGD) is an important component of Striga resistance in sorghum. The objective of this study was to determine gene action influencing MGD of Striga hermonthica and Striga asiatica among selected sorghum lines treated with a biocontrol agent, Fusarium oxysporum f. sp. strigae(FOS) for effective breeding with Striga resistance, and FOS compatibility. Twelve sorghum genotypes were selected based on their Striga resistance, FOS compatibility, and superior agronomic performance. Selected genotypes were crossed using a bi-parental mating design to generate six families for genetic analysis. Agar-gel assays were used to determine low haustorium initiation factor(LHF) using the 12 parental lines, their F_1 progenies, backcross derivatives, and F_2 segregants in two sets. One set had S. hermonthica seed and the other one had S. asiatica seed. Both were treated with and without FOS. Genotypes were evaluated using a split-plot design with three replications and MGD data were recorded followed by generation mean analysis. FOS reduced MGD by 1cm under both S. hermonthica and S. asiatica infestations. Additive, dominance, and epistatic gene actions were involved in the control of MGD of the two Striga species in the evaluated populations. On average, the relative contribution of additive, additive×additive and dominance×dominance genetic effects on the MGD of S. hermonthica and S. asiatica, with FOS, were 20, 33, and 36%; and 21, 32, and 35%, respectively. Breeding methods exploiting these genetic effects may provide enhanced response to selection for Striga resistance and FOS compatibility in integrated Striga management(ISM) programmes.     

TGF-beta3 exists in bony fish

A partial nucleotide sequence of transforming growth factor-beta3 (TGF-beta3) has been isolated from the Siberian sturgeon (Acipenser baeri), rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla), confirming a ubiquitous presence in the ray-finned (Actinopterygian) bony fish. The bony fish TGF-beta3 is highly conserved, with some 83-84% nucleotide identity (coding region) and 90-95% predicted amino acid identity to known homeotherm TGF-beta3's. Far lower homologies are apparent with other known TGF-beta isoforms in fish (e.g. 64-66% and 81-82% amino acid identity to trout TGF-beta 1/5 and carp TGF-beta2 respectively). Phylogenetic tree analysis showed that the fish TGF-beta3's clustered with the known homeotherm TGF-beta3's. The relatively tight clustering of TGF-beta1, TGF-beta2 and TGF-beta3 was in contrast to the TGF-beta5's, which are clearly a more heterogenous group.     

Effect of Quil A,a saponin derivative,on the response of sheep to alum precipitatedBacteroides nodosus vaccines

Alum precipitatedBacteroides nodosus vaccines prepared from two antigens with and without the saponin derivative, Quil A, did not induce adverse tissue reactions in sheep injected subcutaneously. Vaccinated, non-infected Merino sheep had higher agglutinin antibody titres when the vaccines included Quil A. Moreover, the recovery rates in vaccinated sheep affected with foot-rot were higher when the vaccines included Quil A.     

The occurrence, prevalence and transmission of Bacteroides nodosus infection in cattle

Following reports of findings of ovine foot-rot flora in the feet of cattle, a study was undertaken to determine the prevalence of Bacteroides nodosus infection in the apparently normal cattle population. We found that 34.5 to 74.2 per cent of the animals examined on different farms had B nodosus present in one or more feet. B nodosus was not the most prevalent bacterium observed in smears from cattle. Other Gram negative species including Fusiformis necrophorus and many Gram positive cocci and coccobacilli were also present. Macroscopic lesions in the interdigital skin characterised by erosion and hyperkeratosis were usually associated with the occurrence of B nodosus. B nodosus isolated from cattle induced mild interdigital dermatitis in experimental cattle and sheep and the infection was transmitted to recipient cattle and sheep under field conditions. Virulent foot-rot of sheep was not transmitted to recipient cattle in conditions where the disease spread to susceptible sheep.     

Resistance to amitraz in the parasitic honey bee mite Varroa destructor is associated with mutations in the β-adrenergic-like octopamine receptor

Varroa destructor is considered a major reason for high loss rate of Western honey bee (Apis mellifera) colonies. To prevent colony losses caused by V. destructor, it is necessary to actively manage the mite population. Beekeepers, particularly commercial beekeepers, have few alternative treatments other than synthetic acaricides to control the parasite, resulting in intensive treatment regimens that led to the evolution of resistance in mite populations. To investigate the mechanism of the resistance to amitraz detected in V. destructor mites from French and U.S. apiaries, we identified and characterized octopamine and tyramine receptors (the known targets of amitraz) in this species. The comparison of sequences obtained from mites collected from different apiaries with different treatment regimens, showed that the amino acid substitutions N87S or Y215H in the OctβR were associated with treatment failures reported in French or U.S. apiaries, respectively. Based on our findings, we have developed and tested two high throughput diagnostic assays based on TaqMan technology able to accurately detect mites carrying the mutations in this receptor. This valuable information may be of help for beekeepers when selecting the most suitable acaricide to manage V. destructor.

     

Large-scale turbidostat culture of marine microalgae

A simple and inexpensive device is described which maintains cultures of marine microalgae at predetermined cell densities by the automatic control of harvesting and replenishment of the culture volume with fresh medium. Cultures were maintained at a range of cell densities in 80-litre internally illuminated vessels and the daily cell production yield was evaluated.Maximum yields of 0·8–1·0×10¹² cells day^?1 of Isochrysis aff. galbana Green and 0·8–1·2×10¹¹ cells day^?1 of Tetraselmis suecica (Kylin) Butch. were obtained at culture densities of 15–17×10³ cells μlitre^?1 and 19–21×10² cells μlitre^?1, respectively. Turbidostat cultures of Skeletonema costatum (Grev.) Cleve could not consistently be maintained above 5–7×10³ cells μlitre^?1.