Analysis of Maxillofacial Fractures Based on the Etiology in Southeast China: A 10-Year, Multi-Center Study.

BACKGROUND: The aim of this study was to explore the characteristics and correlation of maxillofacial fractures and concurrent injuries with different injury causes. METHODS: In this retrospective study, data were collected from patients treated for maxillofacial fractures in 3 oral and maxillofacial surgery departments in Southeast China, from January 2010 to December 2019. The information was obtained from clinical notes and surgical records using a standardized data collection form, and some causes of injuries were confirmed by telephone follow-ups and police records. These patients were divided into 7 groups according to the etiology: bicycle accident, electric bicycle accident, motorcycle accident, automobile accident, fall at ground level, fall from a height, and assault-related accident. Statistical tests were performed using R software (version 3.1.1), and all P-values were computed based on Chi-square tests and set at 0.05. RESULTS: During this 10-year retrospective study, a total of 1772 patients with definite causes were analyzed. The average age was approximately 35.04 years (9 months-94 years). All patients were treated with open reduction and rigidly internal fixation, and the average duration was approximately 6.51 days (range 0 day-50 days), that from the time of the injury to the time of treatment. Traffic accidents were identified as the main cause of maxillofacial fracture (57.62%; n = 1021 of 1772 cases). In different etiology groups, there were statistically significant differences in the distribution of age, sex, maxillofacial fracture type, and concurrent injuries (all P < 0.001). However, the main cause of maxillofacial injuries was falls (fall at ground level and fall from a height) in children, and the highest incidence of the cause of maxillofacial injuries was bicycle accident in adolescents. Compared with the other groups, zygomatic complex fracture was more common in the electric bicycle accident group, panfacial fracture was more common in the automobile accident group, and mandible fracture was more common in the other groups. CONCLUSION: The results of this study suggest that patients with maxillofacial fractures caused by different injuries had their own unique characteristics. These findings may assist us in avoiding misdiagnosis and treatment delays, and may make treatment plans faster.

Inhibition of ferric ion to oxalate oxidase shed light on the substrate binding site.

Oxalate oxidase (OxOx), a well known enzyme catalyzes the cleavage of oxalate to carbon dioxide with reduction of dioxygen to hydrogen peroxide, however its catalytic process is not well understood. To define the substrate binding site, interaction of Fe(3+) ions with OxOx was systemically investigated using biochemical method, circular dichrosim spectroscopy, microscale thermophoresis, and computer modeling. We demonstrated that Fe(3+) is a non-competitive inhibitor with a milder binding affinity to OxOx, and the secondary structure of the OxOx was slightly altered upon its binding. On the basis of the structural properties of the OxOx and its interaction with Fe(3+) ions, two residue clusters of OxOx were assigned as potential Fe(3+) binding sites, the mechanism of the inhibition of Fe(3+) was delineated. Importantly, the residues that interact with Fe(3+) ions are involved in the substrate orienting based on computer docking. Consequently, the interaction of OxOx with Fe(3+) highlights insight into substrate binding site in OxOx.

Implantation of radioactive particles into the cranial base and orbital apex with the use of a magnetic resonance imaging-based surgical navigation system.

OBJECTIVE: The aim of this study was try to find a new way with high precision to implant (125)I-radioactive particles for safe and effective control of tumors that have invaded into the cranial base and orbital regions. STUDY DESIGN: Eight patients with invasive adenoid cystic carcinoma of the cranial base and orbital apex and a history of multiple surgeries were selected. A preoperative magnetic resonance scan was performed and the Brainlab surgical navigation system was used to aid the surgery. RESULTS: The radioactive particles were distributed evenly within the tissue and accurately positioned. No intracranial injury or visual impairment occurred, and the treatment was effective. CONCLUSIONS: The implantation of radioactive particles with the use of magnetic resonance imaging guidance is an effective and safe method for treating invasive malignancies of the skull base and orbital apex, and it should be considered for conditional use.

Assembly of graphene oxide-enzyme conjugates through hydrophobic interaction.

Biochemical and biomedical applications of graphene oxide (GO) critically rely on the interaction of biomolecules with it. It has been previously reported that the biological activity of the GO-enzyme conjugate decreases due to electrostatic interaction between the enzymes and GO. Herein, the immobilization of horseradish peroxidase (HRP) and oxalate oxidase (OxOx) on chemically reduced graphene oxide (CRGO) are reported. The enzymes can be adsorbed onto CRGO directly with a tenfold higher enzyme loading than that on GO, and maximum enzyme loadings reach 1.3 and 12 mg mg(-1) for HRP and OxOx, respectively. Significantly, the more CRGO is reduced, the higher the enzyme loading. The CRGO-HRP conjugates also exhibit higher enzyme activity and stability than GO-HRP. Excellent properties of the CRGO-enzyme conjugates are attributed to hydrophobic interaction between the enzymes and the CRGO. The hydrophobic interaction mode of the CRGO-enzyme conjugates can be applied to other hydrophobic proteins, and thus could dramatically improve the performance of immobilized proteins. The results indicate that CRGO is a potential substrate for efficient enzyme immobilization, and is an ideal candidate as a macromolecule carrier and biosensor.

Effect of substrate (ZnO) morphology on enzyme immobilization and its catalytic activity.

In this study, zinc oxide (ZnO) nanocrystals with different morphologies were synthesized and used as substrates for enzyme immobilization. The effects of morphology of ZnO nanocrystals on enzyme immobilization and their catalytic activities were investigated. The ZnO nanocrystals were prepared through a hydrothermal procedure using tetramethylammonium hydroxide as a mineralizing agent. The control on the morphology of ZnO nanocrystals was achieved by varying the ratio of CH3OH to H2O, which were used as solvents in the hydrothermal reaction system. The surface of as-prepared ZnO nanoparticles was functionalized with amino groups using 3-aminopropyltriethoxysilane and tetraethyl orthosilicate, and the amino groups on the surface were identified and calculated by FT-IR and the Kaiser assay. Horseradish peroxidase was immobilized on as-modified ZnO nanostructures with glutaraldehyde as a crosslinker. The results showed that three-dimensional nanomultipod is more appropriate for the immobilization of enzyme used further in catalytic reaction.

Graphene oxide as a matrix for enzyme immobilization.

Graphene oxide (GO), having a large specific surface area and abundant functional groups, provides an ideal substrate for study enzyme immobilization. We demonstrated that the enzyme immobilization on the GO sheets could take place readily without using any cross-linking reagents and additional surface modification. The atomically flat surface enabled us to observe the immobilized enzyme in the native state directly using atomic force microscopy (AFM). Combining the AFM imaging results of the immobilized enzyme molecules and their catalytic activity, we illustrated that the conformation of the immobilized enzyme is mainly determined by interactions of enzyme molecules with the functional groups of GO.