Thermal Approaches to Interpret Laser Damage Experiments

International audienc

Efficacy of an autogenous vaccine against highly virulent "Staphylococcus aureus" infection in rabbits

[EN] The efficacy of an autogenous vaccine consisting of a whole cell suspension of formalin killed bacteria in sterile buffered saline against Staphylococcus aureus infections was determined, using a well-established rabbit skin infection model. Thirteen eight-week-old rabbits were vaccinated twice subcutaneously with a two-week interval while ten rabbits were injected twice with sterile buffered saline. Two weeks after the last injection, ten vaccinated and all PBS-injected rabbits were inoculated intradermally with 108 cfu of a S. aureus strain which had been shown to be highly virulent for rabbits. Three vaccinated animals served as negative controls and were intradermally injected with sterile buffered saline. All rabbits were examined daily for the development of skin lesions until fourteen days after the experimental infection when all rabbits were euthanised. All animals experimentally infected with S. aureus developed skin abscesses within 24 hours post-inoculation, but in the vaccinated group the maximum abscess diameter was significantly lower than in the non-vaccinated group (P=0.048). The difference between the autovaccinated and non-vaccinated group increased over time (P<0.001). These results indicate that vaccination with an inactivated whole cell bacterin may be useful for control of staphylococcosis in rabbits but does not prevent abscess formation in animals inoculated with a high dose of a highly virulent S. aureus strain.Meulemans, G.; Haesebrouck, F.; Lipinska, U.; Duchateau, L.; Hermans, K. (2011). Efficacy of an autogenous vaccine against highly virulent "Staphylococcus aureus" infection in rabbits. World Rabbit Science. 19(1):1-9. https://doi.org/10.4995/wrs.2011.8121919

The use of equine chondrogenic‐induced mesenchymal stem cells as a treatment for osteoarthritis : a randomised, double‐blinded, placebo‐controlled proof‐of‐concept study

Background: There is a need to improve therapies for osteoarthritis in horses. Objectives To assess the efficacy of equine allogeneic chondrogenic-induced mesenchymal stem cells combined with equine allogeneic plasma as a novel therapy for osteoarthritis in horses. Study design: Randomised, double-blinded, placebo-controlled experiment. Methods: In 12 healthy horses, osteoarthritis was induced in the metacarpophalangeal joint using an osteochondral fragment-groove model. Five weeks after surgery, horses were randomly assigned to either an intra-articular injection with chondrogenic-induced mesenchymal stem cells + equine allogeneic plasma (= intervention) or with 0.9% saline solution (= control). From surgery until the study end, horses underwent a weekly joint and lameness assessment. Synovial fluid was collected for cytology and biomarker analysis before surgery and at Weeks 5, 5 + 1d, 7, 9 and 11. At Week 11, horses were subjected to euthanasia, and the metacarpophalangeal joints were evaluated macroscopically and histologically. Results: No serious adverse events or suspected adverse drug reactions occurred during the study. A significant improvement in visual and objective lameness was seen with the intervention compared with the control. Synovial fluid displayed a significantly higher viscosity and a significantly lower glycosaminoglycan concentration in the intervention group. Other biomarkers or cytology parameters were not significantly different between the treatment groups. Significantly less wear lines and synovial hyperaemia were present in the intervention group. The amount of cartilage oligomeric matrix protein, collagen type II and glycosaminoglycans were significantly higher in the articular cartilage of the intervention group. Main limitations: This study assessed the short-term effect of the intervention on a limited number of horses, using an osteoarthritis model. This study also included multiple statistical tests, increasing the risk of type 1 error. Conclusions: Equine allogeneic chondrogenic-induced mesenchymal stem cells combined with equine allogeneic plasma may be a promising treatment for osteoarthritis in horses

Differential atrial performance at rest and exercise in athletes: Potential trigger for developing atrial dysfunction?

International audienc

Evaluation of acute kidney injury in dogs with complicated or uncomplicated Babesia rossi infection

Dogs with babesiosis can present with multiple complications, including acute kidney injury (AKI). The objective of this study was to characterize AKI in dogs with babesiosis caused by Babesia rossi at presentation and after treatment. Thirty-five client-owned dogs with B. rossi infection and 10 control dogs were included in this prospective observational study. Blood and urine were collected in Babesia-infected dogs at presentation (T-0, n = 35), after 24 h (T-24h, n = 11), and after 1 month (T-1m, n = 9). The following urinary kidney injury biomarkers were assessed: urinary protein to creatinine ratio (UPC), urinary glomerular injury biomarkers (immunoglobulin G (uIgG) and C-reactive protein (uCRP)), and urinary tubular injury biomarkers (retinol-binding protein (uRBP) and neutrophil gelatinase-associated lipocalin (uNGAL)). Serum functional renal biomarkers were creatinine (sCr) and symmetric dimethylarginine (sSDMA). Post-mortem kidney biopsies were analyzed by light and transmission electron microscopy. At T-0, all kidney injury biomarkers were significantly higher in Babesia-infected dogs compared to healthy controls (P 0.05). At T-24h, all urinary tubular injury biomarkers and UPC decreased significantly (P 0.5). Significant changes in functional renal biomarkers were not seen after treatment (P > 0.05). Dogs with complicated babesiosis had significantly higher glomerular injury biomarkers, UPC, and sSDMA compared to uncomplicated cases (P 0.1). Dogs with babesiosis caused by B. rossi showed transient kidney injury, which was detected by all kidney injury biomarkers, but remained undetected by functional biomarkers. All infected dogs, irrespective of disease severity, suffered comparable kidney injury based on tubular injury biomarker concentrations, while loss of function was seen more often in dogs with complicated babesiosis based on sSDMA results

Disentangled UHMWPE@silica powders for potential use in power bed fusion based additive manufacturing

Disentangled ultrahigh molecular weight polyethylene dUHMWPE (Mw ∼ 2.106 Da) particles in a reactor blend with HDPE are catalytically prepared from ethylene, mediated by a new catalyst from N,N'-(2,6-pyridinediyl diethylidyne) bis[2,6-di-3-propenyl-benzenamine] iron dichloride and triethyl aluminum. These particles could be laser sintered, but not automatically processed in an SLS machine. The same catalyst supported on microsilica particles gives access to composite dUHMWPE@silica particle powder with particle sizes below 200 µm. Testing bars prepared by heat pressing have an Emod of 150 MPa, an elongation at break at 450 % and an ultimate strength of 39 ± 11 MPa. A SEM image indicates a silica induced crystallization into pseudo spherulites of 500 µm size. The dUHMWPE@silica composite particles have an fcc flowability value of 3.4 in a ring shear tester, and a low density of 150 kg.m−3. Additivation with nanosilica powder (1 wt%) and carbon black (0.25 wt%) allowed to process the composite in an SLS machine. The printed parts showed severe caking, but also a complete welding of the powder, albeit with voids on account of the low particle density