Finite element analysis of a novel pin-sleeve system for external fixation of distal limb fractures in horses

The transfixation pin cast (TPC) is an external skeletal fixation technique used to treat horses with distal limb fractures, but its use is often associated with pin-loosening and an increased risk of treatment failure. To address implant loosening, the pin sleeve cast system (PSC) was recently designed and consists of a pin-sleeve unit inserted into the bone. Each pin runs through a sleeve placed in the bone, making contact at two fixed points only within the sleeve. Each pin is attached to a ring embedded in a resin cast. In this report, the mechanical performance of a traditional TPC pin arrangement was compared with that of the PSC using validated finite element models of bone substitutes previously tested in vitro. The PSC resulted in a marked reduction in peak strain magnitude around the pins and a more even distribution of strain across the bone cortex. The two systems resulted in comparable proximal fragment displacement and had a similar stress concentration around bone defects during implant removal. The findings suggest that the PSC load transfer mechanism is effective even in geometrically complex structures like equine bones.     

Clinical pharmacokinetics of a dexmedetomidine–methadone combination in dogs undergoing routine anaesthesia after buccal or intramuscular administration

This study aimed to define the pharmacokinetic profiles of dexmedetomidine and methadone administered simultaneously in dogs by either an oral transmucosal route or intramuscular route and to determine the bioavailability of the oral transmucosal administration relative to the intramuscular one of both drugs, so as the applicability of this administration route in dogs. Twelve client‐owned dogs, scheduled for diagnostic procedures, were treated with a combination of dexmedetomidine hydrochloride (10 μg/kg) and methadone hydrochloride (0.4 mg/kg) through an oral transmucosal route or intramuscularly. Oral transmucosal administration caused ptyalism in most subjects, and intramuscular administration caused transient peripheral vasoconstriction. The results showed reduced and delayed absorption of both dexmedetomidine and methadone when administered through an oral transmucosal route, with median (range) C_max values of 0.82 (0.42–1.49) ng/ml and 13.22 (2.80–52.30) ng/ml, respectively. The relative bioavailability was low: 16.34% (dexmedetomidine) and 15.5% (methadone). Intramuscular administration resulted in a more efficient absorption profile, with AUC and C_max values for both drugs approximately 10 times higher. Dexmedetomidine and methadone administered simultaneously by an oral transmucosal route using injectable formulations were not well absorbed through the oral mucosa. Nevertheless, additional studies on these drugs combination using alternative administration routes are recommended.     

Prolongation of survival of dogs with oral malignant melanoma treated by en bloc surgical resection and adjuvant CSPG4‐antigen electrovaccination

Reported post‐surgery 1‐year survival rate for oral canine malignant melanoma (cMM) is around 30%; novel treatments are needed as the role of adjuvant chemotherapy is unclear. This prospective study regards adjuvant electrovaccination with human chondroitin sulfate proteoglycan‐4 (hCSPG4)‐encoded plasmid in 23 dogs with resected II/III‐staged CSPG4‐positive oral cMM compared with 19 dogs with resected only II/III‐staged CSPG4‐positive oral cMM. Vaccination resulted in 6‐, 12‐, 18‐ and 24‐month survival rate of 95.6, 73.9, 47.8 and 30.4%, respectively [median survival time (MST) 684 days, range 78–1694, 8 of 23 dogs alive] and 6‐, 12‐, 18‐ and 24‐month disease‐free interval (DFI) rate of 82.6, 47.8, 26.1 and 17.4%, respectively (DFI 477 days, range 50–1694). Non‐vaccinated dogs showed 6‐, 12‐, 18‐ and 24‐month survival rate of 63.2, 26.3, 15.8 and 5.3%, respectively (MST 200 days, range 75–1507, 1 of 19 dogs alive) and 6‐, 12‐, 18‐ and 24‐month DFI rate of 52.6, 26.3, 10.5 and 5.3%, respectively (DFI 180 days, range 38–1250). Overall survival and DFI of vaccinated dogs was longer in those <20 kg. In vaccinated and non‐vaccinated dogs local recurrence rate was 34.8 and 42%, respectively while lung metastatic rate was 39 and 79%, respectively.     

Priority knowledge needs for management of migratory fish species in Cambodia

Despite their economic and ecological importance, migratory fishes of the Lower Mekong Basin (LMB) remain understudied, which hampers effective management to sustain valuable fisheries and address serious threats such as habitat degradation, development and overharvest. From a list of potential knowledge needs, a group of fisheries professionals most frequently identified six top priorities for managing migratory fishes in Cambodia: (1) population abundances and trends, (2) life cycles and life history, (3) migration timing and triggers, (4) migration routes and distances, (5) locations of key habitats and spawning areas, and (6) environmental and habitat requirements. These needs are discussed along with nine relevant methodologies for addressing them, including fisheries-dependent and fisheries-independent sampling, reproductive techniques and captive studies, otolith and genetic analysis tools, and tagging and imaging techniques. A suggested research framework is also presented to inform adaptive management of migratory fishes. While emphasis is given to Cambodia, the analysis is also applicable to other LMB countries, given that migratory fishes occur throughout the basin and migrate across borders. It is suggested that a robust research and monitoring agenda is required to prioritise knowledge needs and select appropriate methodologies to answer questions vital to inform sustainable migratory fish management in Cambodia.     

Identification of artichoke SSR markers: molecular variation and patterns of diversity in genetically cohesive taxa and wild allies

A set of 24 microsatellite markers was identified in the artichoke genome, using various approaches. A genomic library allowed the development of 14 SSR markers, whereas the other 10 were obtained from gene intron/UTR regions or from other species. Allelic variation was scored in C. cardunculus (artichoke, cultivated cardoon, and wild cardoon) samples, and in other wild Cynara allies. For the 23 polymorphic loci, a total of 165 alleles were scored, 135 of which in the artichoke primary genepool, and the remaining ones in the other Cynara species. Some allele combinations were able to identify artichoke varietal types, and some alleles were unique to specific groups. This makes these markers potentially useful in product traceability and in contributing to the saturation of genetic maps. The percentage of shared alleles between C. cardunculus taxonomic groups, and Nei’s genetic distances indicated that wild cardoons from the Eastern Mediterranean were more closely related to artichoke and less to cultivated cardoon in comparison to wild cardoons from the Western Mediterranean, and the genetic distance between the two wild cardoon genepools was rather high. The UPGMA dendrogram based on Nei’s genetic distances revealed that artichokes formed a fairly defined cluster, whereas Eastern wild cardoons occupied another branch, and Western wild cardoons were clustered together with cultivated cardoons. The transferability of microsatellite markers to other Cynara wild species was quite good. Sequencing alleles at three loci showed that, apart from microsatellite length variation, point mutations and insertion/deletions were quite abundant especially when comparing C. cardunculus to the other Cynara species. In the sequenced regions, some SNPs were identified which distinguished artichoke on one side, and cultivated and wild cardoon on the other, while other SNPs were apportioned according to the geographic distribution of Cynara wild species.