A forecasting model for suitable dental implantation in canine mandibular premolar region based on finite element analysis.

In recent years, dental implants have become a trend in the treatment of human patients with missing teeth, which may also be an acceptable method for companion animal dentistry. However, there is a gap challenge in determining appropriate implant sizes for different dog breeds and human. In this study, we utilized skull computed tomography data to create three-dimensional models of the mandibles of dogs in different sizes. Subsequently, implants of various sizes were designed and subjected to biomechanical finite element analysis to determine the optimal implant size. Regression models were developed, exploring the relationship between the average weight of dogs and the size of premolar implants. Our results illustrated that the regression equations for mean body weight (x, kg) and second premolar (PM2), third premolar (PM3), and fourth premolar (PM4) implant length (y, mm) in dogs were: y = 0.2785x + 7.8209, y = 0.2544x + 8.9285, and y = 0.2668x + 10.652, respectively; the premolar implant diameter (mm) y = 0.0454x + 3.3506, which may provide a reference for determine suitable clinical implant sizes for dogs.

Parthenolide inhibits polyethylene particle-induced mouse calvarial osteolysis in vivo.

BACKGROUND: Periprosthetic osteolysis and aseptic loosening (AL) after joint arthroplasty are serious problems encountered after an implant surgery. AL is possibly caused by osteolysis or local bone resorption induced by implant-derived wear particles. However, effective treatments for osteoclastic bone resorption and AL mediated by wear particles have not been developed except surgical revision. Therefore, a new strategy should be developed to improve osteolysis associated with AL via pharmacologic intervention. MATERIALS AND METHODS: The effects of parthenolide (PTN), a nuclear factor-kappa B inhibitor and sesquiterpene lactone, on polyethylene particle-induced osteolysis in vivo were investigated using a mouse calvarial model. Bone volume/tissue volume (BV/TV, %), bone surface/bone volume (BS/BV, 1/mm), osteoclast number per bone perimeter (N.Oc/B.Pm, /mm), and eroded surface per bone surface (ES/BS, %) were determined by micro-computed tomography and histologic analyses. RESULTS: Severe bone resorption and rapid osteoclast formation were found in the cranium of the subjects after polyethylene particles were implanted. ES/BS (P < 0.001), N.Oc/B.Pm (group III, P < 0.05; group IV, P < 0.001), and BS/BV (P < 0.001) increased compared with those in group II; BS/BV (P < 0.001) decreased in group II but was improved in groups III and IV, which were treated with PTN. No significant difference in these parameters was observed among groups I, III, and IV. CONCLUSIONS: PTN possibly elicited therapeutic effects on osteolysis induced by wear particles, indicating that PTN could be used as a therapeutic agent of AL induced by wear particles.

Biomechanics of Dental Implantation in the Giant Panda (Ailuropoda melanoleuca): A Comparative Study Using Finite Element Analysis.

Giant pandas have a high incidence of tooth wear, loss, and fracture since their diet is specifically bamboo. Dental implantation is a common treatment for tooth loss in humans while rarely reported in wild animals. To explore the applicability of dental implantation in giant pandas, this study measured mandible parameters of the giant panda, from an adult skeletal specimen. The mandible bone block model was developed using computer-aided design 3D mechanical drawing software. Implants of different radius and thread types of the third premolar tooth (PM3) were assembled and imported into an analysis software system for finite element analysis. As a result, the reverse buttress implant with a radius of 7.5 mm and 8.3 mm, and a length of 15 mm was found to be the most suitable implant for use in the giant panda PM3. This study provides a reference for appropriate clinical giant panda dental implantation, although, the feasibility of giant panda dental implantation needs to be studied further.

Berberine inhibits lipopolysaccharide- and polyethylene particle-induced mouse calvarial osteolysis in vivo.

BACKGROUND: Wear particle-induced osteolysis could lead to the aseptic loosening of implants. Studies have suggested that endotoxins, such as lipopolysaccharides (LPS), may be the primary causes of wear particle-mediated osteolysis, and that osteolysis may originate from subclinical levels of bacterial infection. However, effective therapies against wear particles and gram-negative bacterial or LPS-induced bone resorption are limited. MATERIALS AND METHODS: In the current study, the effect of berberine on LPS- and polyethylene (PE) particle-induced osteolysis in vivo was investigated using a mouse calvarial model. Osteoclast number per bone perimeter and eroded surface per bone surface were measured. RESULTS: Berberine (10 mg/kg), injected either simultaneously with LPS or 3 d after LPS (25 mg/kg) treatment, blocked LPS-induced osteoclast recruitment and bone resorption in the mouse calvarial model. A daily single-dose of berberine (10 mg/kg), injected either simultaneously with PE particles or 4 d after treatment with PE particles, blocked PE particle-induced osteoclast recruitment and bone resorption. Berberine treatment markedly decreased LPS and PE particle-induced osteoclast recruitment and bone resorption in the murine calvarial model. CONCLUSION: These results suggest that berberine may have therapeutic effect for osteolysis induced by wear particles and LPS in gram-negative bacteria.

Berberine prevents lethal EV71 neurological infection in newborn mice.

Enterovirus 71 (EV71) is the major pathogen causing fatal neurological complications of hand, foot, and mouth disease (HFMD) in young children. Currently no effective antiviral therapy is available. In the present study, we found that natural compound Berberine (BBR) displayed potent inhibitory effects on EV71 replication in various neural cells (IC50 of 2.79-4.03 µM). In a newborn mouse model of lethal EV71 infection, Berberine at 2-5 mg/kg markedly reduced mortality and clinical scores. Consistently, the replication of EV71 and pathological changes were attenuated in various infected organs including brain and lung with BBR treatment. Interestingly, EV71 infection in the brain mainly localized in the peripheral zone of brainstem and largely in astrocytes. Primary culture of astrocytes from newborn mouse brain confirmed the efficient EV71 replication that was mostly inhibited by BBR treatment at 5 µM. Further investigations revealed remarkably elevated cellular reactive oxygen species (ROS) levels that coincided with EV71 replication in primary cultured astrocytes and various cell lines. BBR largely abolished the virus-elevated ROS production and greatly diminished EV71 replication by up-regulating NFE2 like bZIP transcription factor 2 (Nrf2) via the kelch like ECH associated protein 1 (Keap)-Nrf2 axis. The nuclear localization of Nrf2 and expression of downstream antioxidant enzymes heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1) were increased significantly by BBR treatment. Collectively, our findings revealed that BBR prevents lethal EV71 neurological infection via inhibiting virus replication through regulating Keap-Nrf2 axis and ROS generation in astrocytes of brainstem, thus providing a potential antiviral treatment for severe EV71 infection associated with neurological complications.

Cellulose-dependent expression and antibacterial characteristics of surfactin from Bacillus subtilis HH2 isolated from the giant panda.

Surfactin secreted by Bacillus subtilis can confer strong, diverse antipathogenic effects, thereby benefitting the host. Carbon source is an important factor for surfactin production. However, the mechanism that bacteria utilize cellulose, the most abundant substance in the intestines of herbivores, to produce surfactin remains unclear. Here, we used B. subtilis HH2, isolated from the feces of a giant panda, as a model to determine changes in surfactin expression in the presence of different concentrations of cellulose by quantitative polymerase chain reaction and high-performance liquid chromatography. We further investigated the antimicrobial effects of surfactin against three common intestinal pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella enterica) and its resistance to high temperature (60-121°C), pH (1-12), trypsin (100-300 µg/mL, pH 8), and pepsin (100-300 µg/mL, pH 2). The results showed that the surfactin expressed lowest in bacteria cultured in the presence of 1% glucose medium as the carbon source, whereas increased in an appropriate cellulose concentration (0.67% glucose and 0.33% cellulose). The surfactin could inhibit E. coli and Staphylococcus aureus, but did not affect efficiently for Salmonella enterica. The antibacterial ability of surfactin did not differ according to temperature (60-100°C), pH (2-11), trypsin (100-300 µg/mL), and pepsin (100-300 µg/mL; P > 0.05), but decreased significantly at extreme environments (121°C, pH 1 or 12; P < 0.05) compared with that in the control group (37°C, pH = 7, without any protease). In conclusion, our findings indicated that B. subtilis HH2 could increase surfactin expression in an appropriate cellulose environment and thus provide benefits to improve the intestinal health of herbivores.

Transcriptional regulation and adaptation to a high-fiber environment in Bacillus subtilis HH2 isolated from feces of the giant panda.

In the giant panda, adaptation to a high-fiber environment is a first step for the adequate functioning of intestinal bacteria, as the high cellulose content of the gut due to the panda's vegetarian appetite results in a harsh environment. As an excellent producer of several enzymes and vitamins, Bacillus subtilis imparts various advantages to animals. In our previous study, we determined that several strains of B. subtilis isolated from pandas exhibited good cellulose decomposition ability, and we hypothesized that this bacterial species can survive in and adapt well to a high-fiber environment. To evaluate this hypothesis, we employed RNA-Seq technology to analyze the differentially expressed genes of the selected strain B. subtilis HH2, which demonstrates significant cellulose hydrolysis of different carbon sources (cellulose and glucose). In addition, we used bioinformatics software and resources to analyze the functions and pathways of differentially expressed genes. Interestingly, comparison of the cellulose and glucose groups revealed that the up-regulated genes were involved in amino acid and lipid metabolism or transmembrane transport, both of which are involved in cellulose utilization. Conversely, the down-regulated genes were involved in non-essential functions for bacterial life, such as toxin and bacteriocin secretion, possibly to conserve energy for environmental adaptation. The results indicate that B. subtilis HH2 triggered a series of adaptive mechanisms at the transcriptional level, which suggests that this bacterium could act as a probiotic for pandas fed a high-fiber diet, despite the fact that cellulose is not a very suitable carbon source for this bacterial species. In this study, we present a model to understand the dynamic organization of and interactions between various functional and regulatory networks for unicellular organisms in a high-fiber environment.

Promotion of bone formation by naringin in a titanium particle-induced diabetic murine calvarial osteolysis model.

Diabetic patients have an increased risk of prosthesis failure requiring revision surgery. Furthermore, skeletal defects are observed in conjunction with type 1 diabetes. Using a titanium particle-induced calvarial osteolysis model in diabetic mice, we investigated the effect of diabetes on the osteolytic process and the role of naringin in its prevention. Three groups each of nondiabetic or diabetic mice were treated with vehicle only, with particles only, or with particles then naringin for 10 days. Alteration of bone indices near the midline suture were then analyzed by microcomputed tomography scanning and histology. Serum levels of osteocalcin (OCN) and cross-linked N-telopeptide of type I collagen (NTx) were measured by enzyme-linked immunosorbent assay. The decreases in new bone formation (p < 0.05), calvaria thickness (p < 0.05), bone volume (p < 0.05), midline suture area (p < 0.05), and OCN concentration (p < 0.05) found in diabetic mice were normalized with naringin treatment. Diabetic state promoted particle-induced osteolysis. Naringin, an osteoanabolic agent, improved bone indices apparently by stimulating bone formation. Therefore, naringin may be beneficial in preventing and treating debris-mediated periprosthetic osteolysis after total joint replacement, especially in diabetics.