A novel acrylic orthodontic device for treatment of linguoverted mandibular canine teeth in small dogs.

Linguoverted mandibular canine teeth (LMC) is a common malocclusion in dogs. Several inclined bite-plane techniques using acrylic resin have been introduced to correct LMC in dogs. Although these techniques have suggested modifications to overcome shortcomings, there are still limitations; e.g., high technical sensitivity, as the viscous acrylic resin must still be fabricated in the oral cavity. The authors developed a novel method for small-breed dogs that uses a doughy acrylic resin form to achieve an easy intraoral design and extraoral fabrication. Eight small-breed dogs were presented to evaluate and treat malocclusion causing palatal trauma. First, a Class-1 malocclusion with linguoversion of the mandibular canine teeth (6 dogs with unilateral LMC and 2 dogs with bilateral) was diagnosed based on oral examination. Dogs were treated with the new method using a doughy acrylic resin form for 6 to 7 wk and had posttreatment follow-up 1 y after the procedure. All treated canine teeth were in correct positions 1 y after the appliances were removed. Key clinical message: The authors believe that the new method using a doughy acrylic resin form could be a good alternative for veterinarians to use when treating LMC.

Un nouveau dispositif orthodontique en acrylique pour le traitement des canines mandibulaires linguoverties chez les petits chiens. Les canines mandibulaires linguoverties (LMC) sont une malocclusion courante chez le chien. Plusieurs techniques de plan de morsure incliné utilisant de la résine acrylique ont été introduites pour corriger la LMC chez le chien. Bien que ces techniques aient suggéré des modifications pour surmonter les lacunes, elles présentent encore des limites; par exemple, une sensibilité technique élevée, car la résine acrylique visqueuse doit encore être fabriquée dans la cavité buccale. Les auteurs ont développé une nouvelle méthode pour les chiens de petite race qui utilise une forme pâteuse de résine acrylique pour obtenir une conception intra-orale et une fabrication extra-orale faciles. Huit chiens de petite race ont été présentés pour évaluer et traiter une malocclusion provoquant un traumatisme palatin. Tout d'abord, une malocclusion de classe 1 avec linguoversion des canines mandibulaires (6 chiens avec LMC unilatérale et 2 chiens avec bilatérale) a été diagnostiquée sur la base d'un examen oral. Les chiens ont été traités avec la nouvelle méthode en utilisant une forme pâteuse de résine acrylique pendant 6 à 7 semaines et ont fait l'objet d'un suivi post-traitement 1 an après la procédure. Toutes les canines traitées étaient dans la bonne position un an après le retrait des appareils.Message clinique clé:Les auteurs estiment que la nouvelle méthode utilisant une forme pâteuse de résine acrylique pourrait être une bonne alternative que les vétérinaires pourraient utiliser lors du traitement du LMC.(Traduit par Dr Serge Messier).

Application of modified porcine xenograft by collagen coating in the veterinary field: pre-clinical and clinical evaluations.

Introduction: This study aimed to identify a collagen-coating method that does not affect the physicochemical properties of bone graft material. Based on this, we developed a collagen-coated porcine xenograft and applied it to dogs to validate its effectiveness. Methods: Xenografts and collagen were derived from porcine, and the collagen coating was performed through N-ethyl-N'-(3- (dimethylamino)propyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) activation. The physicochemical characteristics of the developed bone graft material were verified through field emission scanning electron microscope (FE-SEM), brunauer emmett teller (BET), attenuated total reflectance-fourier transform infrared (ATR-FTIR), and water absorption test. Subsequently, the biocompatibility and bone healing effects were assessed using a rat calvarial defect model. Results: The physicochemical test results confirmed that collagen coating increased bone graft materials' surface roughness and fluid absorption but did not affect their porous structure. In vivo evaluations revealed that collagen coating had no adverse impact on the bone healing effect of bone graft materials. After confirming the biocompatibility and effectiveness, we applied the bone graft materials in two orthopedic cases and one dental case. Notably, successful fracture healing was observed in both orthopedic cases. In the dental case, successful bone regeneration was achieved without any loss of alveolar bone. Discussion: This study demonstrated that porcine bone graft material promotes bone healing in dogs with its hemostatic and cohesive effects resulting from the collagen coating. Bone graft materials with enhanced biocompatibility through collagen coating are expected to be widely used in veterinary clinical practice.

Evaluation of Biocompatibility and Healing Properties of Dural Substitutes Produced by Electrospinning Technology.

BACKGROUND/AIM: Dural reconstruction is a critical process after neurosurgical procedures. Improper dural repair leads to serious side-effects, such as cerebrospinal fluid leakage or infection. This is why it is important to properly repair the dura using a dural substitute, and research into dural substitutes is ongoing. The ideal dural substitute should be non-toxic, biocompatible, and capable of maintaining adequate tension and preventing cerebrospinal fluid leakage for extended periods in vivo. This study evaluated the biocompatibility and healing properties of Safe-Seal, poly-L-lactic acid synthetic bioabsorbable dural substitute produced by electrospinning technology. MATERIALS AND METHODS: Safe-Seal, was created by electrospinning, which is a technique for nanofiberizing polymers into three-dimensional structures, and its cytotoxicity was evaluated. The animal study used 30 rats, divided into three groups assessed at two time points (4 and 12 weeks). The study groups were a negative control group with no treatment, an experimental group with Safe-Seal (TDM Co. Ltd., Gwangju, Republic of Korea) implantation, and a positive control group with a commercial product, Redura® (Medprin Biotech, Frankfurt, Germany) implantation. RESULTS: Safe-Seal exhibited no cytotoxic or adverse effects in the in vivo animal study. Histologically, Safe-Seal displayed less inflammatory cell infiltration, less adhesion to brain tissue, and connectivity with the surrounding dura mater as compared to the negative control group and without any significant differences from Redura® in all evaluation criteria. CONCLUSION: Safe-Seal presented adequate biocompatibility in vivo and contributed to the healing of the dura mater at a similar level to that of Redura® when applied to dural defects.

Synergistic Effect, Improved Cell Selectivity, and Elucidating the Action Mechanism of Antimicrobial Peptide YS12.

Antimicrobial peptides (AMPs) have attracted considerable attention as potential substitutes for traditional antibiotics. In our previous research, a novel antimicrobial peptide YS12 derived from the Bacillus velezensis strain showed broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria. In this study, the fractional inhibitory concentration index (FICI) indicated that combining YS12 with commercial antibiotics produced a synergistic effect. Following these findings, the combination of YS12 with an antibiotic resulted in a faster killing effect against bacterial strains compared to the treatment with the peptide YS12 or antibiotic alone. The peptide YS12 maintained its antimicrobial activity under different physiological salts (Na+, Mg2+, and Fe3+). Most importantly, YS12 exhibited no cytotoxicity towards Raw 264.7 cells and showed low hemolytic activity, whereas positive control melittin indicated extremely high toxicity. In terms of mode of action, we found that peptide YS12 was able to bind with LPS through electrostatic interaction. The results from fluorescent measurement revealed that peptide YS12 damaged the integrity of the bacterial membrane. Confocal laser microscopy further confirmed that the localization of peptide YS12 was almost in the cytoplasm of the cells. Peptide YS12 also exhibited anti-inflammatory activity by reducing the release of LPS-induced pro-inflammatory mediators such as TNF-α, IL-1ß, and NO. Collectively, these properties strongly suggest that the antimicrobial peptide YS12 may be a promising candidate for treating microbial infections and inflammation.

Successful Surgical Outcome of Feline Inductive Odontogenic Tumor in Three Cats.

BACKGROUND/AIM: A feline inductive odontogenic tumor (FIOT) is a rare type of tumor that is unique to young cats. CASE REPORT: Herein, we report on three cats (aged 6 months to 2.5 years) that had a bulging mass on the maxilla. On diagnostic imaging, cases 1 and 3 had bone expansion in the affected area, and all three cats were diagnosed with FIOT by histological examination. Maxillectomy and/or incisivectomy techniques were performed according to the tumor site with an intended surgical margin of 5 mm. To increase both precision and safety, a piezoelectric surgical instrument was used. The local advancement flaps were used to repair the surgical sites. The surgical outcomes were excellent, and there were no major complications related to the surgery or tumor recurrences during long-term follow-up (3-5 years) for any of the cats. CONCLUSION: The results from this study were excellent, which may have been due in part to the choice of the surgical instrument that allowed for the implementation of precise and accurate surgical excision and the tension-free flap method for preventing dehiscence of the surgical site.

Multifunctional microrobot with real-time visualization and magnetic resonance imaging for chemoembolization therapy of liver cancer.

Microrobots that can be precisely guided to target lesions have been studied for in vivo medical applications. However, existing microrobots have challenges in vivo such as biocompatibility, biodegradability, actuation module, and intra- and postoperative imaging. This study reports microrobots visualized with real-time x-ray and magnetic resonance imaging (MRI) that can be magnetically guided to tumor feeding vessels for transcatheter liver chemoembolization in vivo. The microrobots, composed of a hydrogel-enveloped porous structure and magnetic nanoparticles, enable targeted delivery of therapeutic and imaging agents via magnetic guidance from the actuation module under real-time x-ray imaging. In addition, the microrobots can be tracked using MRI as postoperative imaging and then slowly degrade over time. The in vivo validation of microrobot system-mediated chemoembolization was demonstrated in a rat liver with a tumor model. The proposed microrobot provides an advanced medical robotic platform that can overcome the limitations of existing microrobots and current liver chemoembolization.

Effects of a Topically Applied Oral Wound Dressing Film on Intra-oral Wound Healing in Rabbits.

BACKGROUND/AIM: Oral lesions are a common clinical symptom that can impair the quality of life of patients. Several treatments have been developed; however, therapies for wounds on the oral mucosa are symptomatic and unsatisfactory. This study aimed to evaluate the efficacy of an oral wound dressing (OWD) film in healing excision and chemical burns using a rabbit oral wound model and to demonstrate the effect of physical barriers during wound healing. MATERIALS AND METHODS: Excision and chemical burn wounds were induced on the oral hard palate of animals. Four experimental groups were established. The OWD film was applied immediately after surgery and replaced every 24 h over the following 3 days. The animals were sacrificed at 3, 7, and 14 days after surgery. The hard palate tissues were analyzed by histological and immunohistochemical evaluation. The degree of epithelialization, number of proliferating cells, and collagen deposition were evaluated. Statistical significance was analyzed using the Student's t-test. RESULTS: Following application of the OWD film to the excision and chemical burn wounds, the OWD treatment group's epithelial gap and proliferation showed a significant difference compared to those of the untreated group during the proliferative stage of wound healing. However, there was no difference in the epithelial gap in the chemical burn wound model, whereas the OWD treatment group showed a significantly reduced ulcerated area. Collagen deposition in the OWD treatment group was significantly increased during the remodeling stage of wound healing. CONCLUSION: The OWD film treatment promoted wound healing in the oral mucosa by accelerating wound closure and reconstruction.

In Vivo Evaluation of Gamma-Irradiated and Heparin-Immobilized Small-Diameter Polycaprolactone Vascular Grafts with VEGF in Aged Rats.

The effectiveness of small-diameter vascular grafts depends on their antithrombogenic properties and ability to undergo accelerated endothelialization. The extreme hydrophobic nature of poly(ε-caprolactone) (PCL) hinders vascular tissue integration, limiting its use in medical implants. To enhance the antithrombogenicity of PCL as a biomaterial, we grafted 2-aminoethyl methacrylate (AEMA) hydrochloride onto the PCL surface using gamma irradiation; developed a biodegradable heparin-immobilized PCL nanofibrous scaffold using gamma irradiation and N-(3-dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide reaction chemistry; and incorporated vascular endothelial growth factor (VEGF) into the scaffold to promote vascular endothelial cell proliferation and prevent thrombosis on the vascular grafts. We assessed the physicochemical properties of PCL, heparin-AEMA-PCL (H-PCL), and VEGF-loaded heparin-AEMA-PCL (VH-PCL) vascular grafts using scanning electron microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, toluidine blue O staining, and fibrinogen adsorption and surface wettability measurement. In addition, we implanted the vascular grafts into 24-month-old Sprague Dawley rats and evaluated them for 3 months. The H-PCL and VH-PCL vascular grafts improved the recovery of blood vessel function by promoting the proliferation of endothelial cells and preventing thrombosis in clinical and histological evaluation, indicating their potential to serve as functional vascular grafts in vascular tissue engineering.

A Safety Test for Ocular Phototoxicity in the Rabbit After Short-term Exposure to Strong Light.

BACKGROUND/AIM: Self-defense products that use high-intensity light are being developed. The intense light generated by the high-power light-emitting diodes (LEDs) of such self-defense products causes temporary blindness. However, few studies have been conducted on the visual safety of their devices. We, therefore, evaluated the effects of strong light of a short duration on the eyes of rabbits in this study. MATERIALS AND METHODS: The right eyes of 15 rabbits were irradiated for 5 s with a lighting device (25 W, 150 lm/W at 700 mA LED) and four eyes of two rabbits were non-irradiated as controls. Changes in the eye structure and function were evaluated before, and immediately, 30 min, 1 h, 24 h, 7 days and 14 days after light irradiation by full-field electroretinogram (ERG), slit-lamp biomicroscopy, and retinal camera. The thickness of the outer nuclear layer of the retina tissue was measured, and histopathological signs of retinal damage were analyzed. RESULTS: The ERG results showed that night vision was not affected. In day vision, the ERG waveform was temporarily affected immediately after light irradiation; however, it recovered within 24 h. No histopathological signs of damage were observed. CONCLUSION: Application of high-power LED light with short duration as used for self-defense was found to cause temporary phototoxicity, but safety was confirmed as vision recovered within 24 h.

Enhanced Immunomodulation, Anti-Apoptosis, and Improved Tear Dynamics of (PEG)-BHD1028, a Novel Adiponectin Receptor Agonist Peptide, for Treating Dry Eye Disease.

Dry eye disease (DED) is characterized by impaired tear dynamics, leading to complex pathophysiological conditions. (PEG)-BHD1028, a peptide agonist to AdipoRs, was evaluated as a potential therapeutic agent for DED based on the reported physiological function of adiponectin, including anti-inflammation and epithelial protection. Therapeutic effects of (PEG)-BHD1028 were evaluated in experimentally induced EDE with 0.001%, 0.01%, and 0.1% (PEG)-BHD1028 in mice and 0.1%, 0.2%, and 0.4% in rabbits for 10 days. In the rabbit study, 0.05% cyclosporine was also tested as a comparator. The results from the mouse study revealed significant improvement in tear volumes, tear breakup time (TBUT), inflammation, and corneal severity score (CSS) within 10 days at all (PEG)-BHD1028 concentrations. In the rabbit study, the tear volume and TBUT significantly increased in (PEG)-BHD1028 groups compared with vehicle and 0.05% cyclosporine groups. The CSS, apoptosis rate, and corneal thickness of all (PEG)-BHD1028 and 0.05% cyclosporine groups were significantly improved relative to the vehicle group. The immune cell counts of 0.2% and 0.4% (PEG)-BHD1028 treated groups were significantly lower than those of the vehicle group. These results represent the potential of (PEG)-BHD1028 as an effective therapeutic agent for DED.

Therapeutic Efficacy of Artificial Skin Produced by 3D Bioprinting.

The skin protects the body from external barriers. Certain limitations exist in the development of technologies to rapidly prepare skin substitutes that are therapeutically effective in surgeries involving extensive burns and skin transplantation. Herein, we fabricated a structure similar to the skin layer by using skin-derived decellularized extracellular matrix (dECM) with bioink, keratinocytes, and fibroblasts using 3D-printing technology. The therapeutic effects of the produced skin were analyzed using a chimney model that mimicked the human wound-healing process. The 3D-printed skin substitutes exhibited rapid re-epithelialization and superior tissue regeneration effects compared to the control group. These results are expected to aid the development of technologies that can provide customized skin-replacement tissues produced easily and quickly via 3D-printing technology to patients.

Multiple Porous Synthetic Bone Graft Comprising EngineeredMicro-Channel for Drug Carrier and Bone Regeneration.

Due to high demand but limited supply, there has been an increase in the need to replace autologous bone grafts with alternatives that fulfill osteogenic requirements. In this study, two different types of bone grafts were tested for their drug carrying abilities along with their osteogenic properties. Two different types of alendronate-loaded bone grafts, Bio-Oss (bovine bone graft) and InRoad (biphasic synthetic bone graft) were observed to see how different concentrations of alendronate would affect the sustained release to enhance osteogenesis. In this study, defected ovariectomize-induced osteoporotic rat calvarias were observed for 28 days with three different concentrations of alendronate (0 mg, 1 mg, 5 mg) for both Bio-Oss and InRoad. A higher concentration (5 mg) allowed for a more controlled and sustained release throughout the 28-day comparison to those of lower concentrations (0 mg, 1 mg). When comparing Bio-Oss and InRoad through histology and Micro-CT, InRoad showed higher enhancement in osteogenesis. Through this study, it was observed that alendronate not only brings out robust osteogenesis with InRoad bone grafts, but also enhances bone regeneration in an alendronate-concentration-dependent manner. The combination of higher concentration of alendronate and multiple porous bone graft containing internal micro-channel structure of InRoad resulted in higher osteogenesis with a sustained release of alendronate.

Effects of Gamma Radiation-Induced Crosslinking of Collagen Type I Coated Dental Titanium Implants on Osseointegration and Bone Regeneration.

This study aimed to compare two methods of crosslinking collagen type I on implanted titanium surfaces, that is, using glutaraldehyde (GA) or gamma-rays (GRs), in a beagle dog model. For in vivo experiments, implants were allocated to three groups and applied to mandibular bone defects in beagle dogs; Group SLA; non-treated Sandblasted, large grit, acid-etched (SLA) implants, Group GA; SLA implants coated with GA crosslinked collagen type I, Group GR; SLA surface implants coated with collagen type I and crosslinked using 25 kGy of 60Co gamma radiation. New bone µCT volumes were obtained, and histologic and histometric analyses were performed in regions of interest. The GR group had significantly better new bone areas (NBAs) and bone to implant contact (BIC) results than the SLA group (p < 0.05), but the GA and GR groups were similar in this respect. New bone volumes and inter-thread bone densities (ITBD) were non-significantly different in the three groups (p > 0.05). Within the limits of this study, gamma-ray collagen crosslinking on titanium implants can be considered a substitute for glutaraldehyde crosslinking.

Osteogenesis of 3D-Printed PCL/TCP/bdECM Scaffold Using Adipose-Derived Stem Cells Aggregates; An Experimental Study in the Canine Mandible.

Three-dimensional (3D) printing is perceived as an innovative tool for change in tissue engineering and regenerative medicine based on research outcomes on the development of artificial organs and tissues. With advances in such technology, research is underway into 3D-printed artificial scaffolds for tissue recovery and regeneration. In this study, we fabricated artificial scaffolds by coating bone demineralized and decellularized extracellular matrix (bdECM) onto existing 3D-printed polycaprolactone/tricalcium phosphate (PCL/TCP) to enhance osteoconductivity and osteoinductivity. After injecting adipose-derived stem cells (ADSCs) in an aggregate form found to be effective in previous studies, we examined the effects of the scaffold on ossification during mandibular reconstruction in beagle dogs. Ten beagles were divided into two groups: group A (PCL/TCP/bdECM + ADSC injection; n = 5) and group B (PCL/TCP/bdECM; n = 5). The results were analyzed four and eight weeks after intervention. Computed tomography (CT) findings showed that group A had more diffuse osteoblast tissue than group B. Evidence of infection or immune rejection was not detected following histological examination. Goldner trichrome (G/T) staining revealed rich ossification in scaffold pores. ColI, Osteocalcin, and Runx2 gene expressions were determined using real-time polymerase chain reaction. Group A showed greater expression of these genes. Through Western blotting, group A showed a greater expression of genes that encode ColI, Osteocalcin, and Runx2 proteins. In conclusion, intervention group A, in which the beagles received the additional ADSC injection together with the 3D-printed PCL/TCP coated with bdECM, showed improved mandibular ossification in and around the pores of the scaffold.

Treatment of two Asiatic black bears (Ursus thibetanus) with severe injuries and their subsequent release into the wild: a case report.

BACKGROUND: The rehabilitation of injured wildlife and their subsequent release into the wild is a humane act as well as important in wildlife conservation. However, little is known about the animals' fate after release. Therefore, to address these uncertainties, it is essential to adequately describe how the injured animals were treated and managed before releasing into the wild; moreover, post-release monitoring should also be performed. Herein, we document for the first time the process of rescue, surgery, and rehabilitation of severely injured Asiatic black bears (Ursus thibetanus; endangered species in South Korea) and their fate after returning to the wild. CASE PRESENTATION: A six-year-old female (bear-01) and a three-year-old male (bear-02) bears were injured by an illegal snare and collision with a bus, respectively. Bear-01 had broad muscle necrosis and ruptures from the snared ankle on the right thoracic limb, with myiasis, and elbow disarticulation was performed. In bear-02, a non-reducible comminuted fracture of the left humerus was confirmed radiologically, and the operation was performed by using dual plate fixation with hydroxyapatite and recombinant human bone morphogenetic protein-2. The bear-01 and -02 were completely healed approximately 30 and 60 days after surgery, respectively. After that, they underwent rehabilitation for 8 and 25 days, respectively, in an outdoor enclosure similar to their natural habitat. Bear-01 and -02 were released into the wild after 45 and 99 days after surgery, respectively, and their mean daily movement distance during the first 30 days after releasing was 2.9 ± 2.1 and 1.3 ± 1.6 km, respectively. The annual mean 95% Kernel home-range size of bear-01 and bear-02 was 265.8 and 486.9 km2, respectively. They hibernated every winter, gained weight, gave birth to cubs (bear-01), were not found to have any abnormalities in the veterinary tests, and were not involved in any conflicts with humans after returning to the wild. CONCLUSIONS: Bears without one leg or those with dual plates could adapt well in their natural habitat, which shows that our surgical and post-operative treatments were effective. Additionally, minimizing human contact and observing/evaluating behavior during the rehabilitation is essential in reducing human-bear conflicts after release.

Different types of agricultural land use drive distinct soil bacterial communities.

Biogeographic patterns in soil bacterial communities and their responses to environmental variables are well established, yet little is known about how different types of agricultural land use affect bacterial communities at large spatial scales. We report the variation in bacterial community structures in greenhouse, orchard, paddy, and upland soils collected from 853 sites across the Republic of Korea using 16S rRNA gene pyrosequencing analysis. Bacterial diversities and community structures were significantly differentiated by agricultural land-use types. Paddy soils, which are intentionally flooded for several months during rice cultivation, had the highest bacterial richness and diversity, with low community variation. Soil chemical properties were dependent on agricultural management practices and correlated with variation in bacterial communities in different types of agricultural land use, while the effects of spatial components were little. Firmicutes, Chloroflexi, and Acidobacteria were enriched in greenhouse, paddy, and orchard soils, respectively. Members of these bacterial phyla are indicator taxa that are relatively abundant in specific agricultural land-use types. A relatively large number of taxa were associated with the microbial network of paddy soils with multiple modules, while the microbial network of orchard and upland soils had fewer taxa with close mutual interactions. These results suggest that anthropogenic agricultural management can create soil disturbances that determine bacterial community structures, specific bacterial taxa, and their relationships with soil chemical parameters. These quantitative changes can be used as potential biological indicators for monitoring the impact of agricultural management on the soil environment.

Successful Clinical Application of Cancellous Allografts With Structural Support for Failed Bone Fracture Healing in Dogs.

BACKGROUND/AIM: In Korea, small breed dogs including Maltese, Pomeranians, and Yorkshire Terriers are most common. These small dogs are at increased risk for the development of delayed union or nonunion fractures, particularly when the fracture occurs at a site with insufficient surrounded soft tissue such as the ulna and radius. To treat failed bone fracture healing, stable fixation of the fracture and implantation of bone grafts are needed. Among the various types of bone grafts, autograft is considered to be the gold standard. However, the amount of autograft available for harvesting in small dogs is limited. In this study, we report on a novel canine cancellous allograft (C350C) that was prepared using chemicals and low heat treatment (350°C). PATIENTS AND METHODS: We applied C350C in two cases with failed bone fracture healing. Due to the poor osteoinductive capabilities of C350C, we also used recombinant human bone morphogenetic protein-2 (rhBMP-2) and Matrigel as osteoinductive and delivery agents, respectively. RESULTS: In both cases, the fractures healed successfully. CONCLUSION: C350C can be used as a bone graft material that could replace autografts in cases with failed bone fracture healing.

Effects of three-dimensionally printed polycaprolactone/ß-tricalcium phosphate scaffold on osteogenic differentiation of adipose tissue- and bone marrow-derived stem cells.

BACKGROUND: Autogenous bone grafts have several limitations including donor-site problems and insufficient bone volume. To address these limitations, research on bone regeneration is being conducted actively. In this study, we investigate the effects of a three-dimensionally (3D) printed polycaprolactone (PCL)/tricalcium phosphate (TCP) scaffold on the osteogenic differentiation potential of adipose tissue-derived stem cells (ADSCs) and bone marrow-derived stem cells (BMSCs). METHODS: We investigated the extent of osteogenic differentiation on the first and tenth day and fourth week after cell culture. Cytotoxicity of the 3D printed PCL/ß-TCP scaffold was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, prior to osteogenic differentiation analysis. ADSCs and BMSCs were divided into three groups: C, only cultured cells; M, cells cultured in the 3D printed PCL/ß-TCP scaffold; D, cells cultured in the 3D printed PCL/ß-TCP scaffold with a bone differentiation medium. Alkaline phosphatase (ALP) activity assay, von Kossa staining, reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting were performed for comparative analysis. RESULTS: ALP assay and von Kossa staining revealed that group M had higher levels of osteogenic differentiation compared to group C. RT-PCR showed that gene expression was higher in group M than in group C, indicating that, compared to group C, osteogenic differentiation was more extensive in group M. Expression levels of proteins involved in ossification were higher in group M, as per the Western blotting results. CONCLUSION: Osteogenic differentiation was increased in mesenchymal stromal cells (MSCs) cultured in the 3D printed PCL/TCP scaffold compared to the control group. Osteogenic differentiation activity of MSCs cultured in the 3D printed PCL/TCP scaffold was lower than that of cells cultured on the scaffold in bone differentiation medium. Collectively, these results indicate that the 3D printed PCL/TCP scaffold promoted osteogenic differentiation of MSCs and may be widely used for bone tissue engineering.

Evaluation of Porcine Hybrid Bone Block for Bone Grafting in Dentistry.

BACKGROUND/AIM: The purpose of this study was to develop hybrid bone blocks using porcine-derived collagen and low crystalline porcine-derived hydroxyapatite to overcome the disadvantages of commonly used bone grafts in dentistry. MATERIALS AND METHODS: Collagen was added to hydroxyapatite particles to increase the spatial integration of particulate bone grafts. Physicochemical examination and in vivo tests were performed to analyze scaffold's characteristics and evaluate bone regeneration. RESULTS: Porcine hybrid bone block had an irregular and interconnecting macroporous structure that was adequate for bone regeneration and bone ingrowth, and showed a good space-occupying ability to become well positioned. In addition, it showed higher angiogenesis and biodegradability than Bio-Oss Collagen®, a commercialized bone graft used in dental clinics. CONCLUSION: Our results suggest that improved collagen hybrid bone block can be generated when porcine cancellous bone particles and collagen were reasonably mixed. This hybrid bone block was easy in handling had flexibility, good biodegradability and provided bone regeneration.

Successful management of proteinuria and systemic hypertension in a dog with renal cell carcinoma with surgery, telmisartan, and amlodipine.

An 11-year-old neutered male Yorkshire terrier dog was presented with a 3-week history of hematuria and anorexia. A unilateral renal mass was detected and surgically removed. The renal mass was diagnosed on histopathologic examination as a renal carcinoma. Supportive medical therapy was carried out and persistent systemic hypertension was managed using telmisartan.

Gestion réussie de la protéinurie et de l'hypertension systémique chez un chien atteint d'un carcinome rénal à l'aide d'une chirurgie, de telmisartan et d'amlodipine. Un chien Yorkshire terrier mâle stérilisé âgé de 11 ans a été présenté avec une anamnèse de 3 semaines d'hématurie et d'anorexie. Une masse rénale unilatérale a été détectée et excisée par chirurgie. La masse rénale a été diagnostiquée à l'examen histopathologique comme étant un carcinome rénal. Une thérapie médicale de soutien a été réalisée et l'hypertension systémique persistante a été gérée à l'aide de telmisartan.(Traduit par Isabelle Vallières).