Protein S-Glyco-Modification through an Elimination-Addition Mechanism.

Per-O-acetylated unnatural monosaccharides containing a bioorthogonal group have been widely used for metabolic glycan labeling (MGL) in live cells for two decades, but it is only recently that we discovered the existence of an artificial "S-glycosylation" between protein cysteines and per-O-acetylated sugars. While efforts are being made to avoid this nonspecific reaction in MGL, the reaction mechanism remains unknown. Here, we present a detailed mechanistic investigation, which unveils the "S-glycosylation" being an atypical glycosylation termed S-glyco-modification. In alkaline protein microenvironments, per-O-acetylated monosaccharides undergo base-promoted ß-elimination to form thiol-reactive α,ß-unsaturated aldehydes, which then react with cysteine residues via Michael addition. This S-glyco-modification produces 3-thiolated sugars in hemiacetal form, rather than typical glycosides. The elimination-addition mechanism guides us to develop 1,6-di-O-propionyl-N-azidoacetylgalactosamine (1,6-Pr2GalNAz) as an improved unnatural monosaccharide for MGL.

Different Management Approaches in Impacted Maxillary Canines: An Overview on Current Trends and Literature.

AIM: This study aimed to overview and collect the current trends and techniques in managing maxillary impacted canines by retrieving recent literature, in a chronological manner from the prevention to the very late stages of treatment in adults. BACKGROUND: We performed a review on the recent literature regarding the current trends on the management of impacted canines. We have researched various types of available articles such as clinical trials and case presentations, meta- and systematic analyses, and literature reviews focusing on clinical management of impacted canines and their outcome evaluations. We adhered to those articles published within the last decade with a focus on treatment planning for impacted and displaced canines. REVIEW RESULTS: Depending on the diagnosis and its timing of it, a maxillary impacted canine can be managed by either prevention or interception, surgical opening followed by autonomous eruption or orthodontically traction, autotransplantation, and at last by removal and space closure. These techniques are elaborated one by one according to the age and severity of the diagnosis. CONCLUSION: Impaction of the canines is a manageable abnormality which is highly dependent on the timing and localization of the displaced tooth. Early detection will give the upper hand to orthodontists to engage by either prevention through extraction of deciduous canines or intercepting via assistant devices to create more space. According to the clinical situation, open or closed surgical uncovering might be required to bond an attachment. However, generally, those techniques did not show any significant clinical distinction in the outcome assessments. CLINICAL SIGNIFICANCE: These approaches are highly technique sensitive and require collaborations with other specialties. Proper diagnosis and prognosis assessment are necessary before making any decision to bring an impacted canine in alignment.

Accessing Medium-Sized Rings via Vinyl Carbocation Intermediates.

Medium-sized rings (8-11-membered cycles) are often more challenging to synthesize than smaller rings (5-7-membered cycles) due to ring strain. Herein, we report a catalytic method for forming 8- and 9-membered rings that proceeds via the intramolecular Friedel-Crafts reactions of vinyl carbocation intermediates. These reactive species are generated catalytically through the ionization of vinyl toluenesulfonates by a Lewis acidic lithium cation-weakly coordinating anion salt.

Visualizing the distribution of flavonoids in litchi (Litchi chinenis) seeds through matrix-assisted laser desorption/ionization mass spectrometry imaging.

Flavonoids are one of the most important bioactive components in litchi (Litchi chinensis Sonn.) seeds and have broad-spectrum antiviral and antitumor activities. Litchi seeds have been shown to inhibit the proliferation of cancer cells and induce apoptosis, particularly effective against breast and liver cancers. Elucidating the distribution of flavonoids is important for understanding their physiological and biochemical functions and facilitating their efficient extraction and utilization. However, the spatial distribution patterns and expression states of flavonoids in litchi seeds remain unclear. Herein, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used for in situ detection and imaging of the distribution of flavonoids in litchi seed tissue sections for the first time. Fifteen flavonoid ion signals, including liquiritigenin, apigenin, naringenin, luteolin, dihydrokaempferol, daidzein, quercetin, taxifolin, kaempferol, isorhamnetin, myricetin, catechin, quercetin 3-ß-d-glucoside, baicalin, and rutin, were successfully detected and imaged in situ through MALDI-MSI in the positive ion mode using 2-mercaptobenzothiazole as a matrix. The results clearly showed the heterogeneous distribution of flavonoids, indicating the potential of litchi seeds for flavonoid compound extraction. MALDI-MS-based multi-imaging enhanced the visualization of spatial distribution and expression states of flavonoids. Thus, apart from improving our understanding of the spatial distribution of flavonoids in litchi seeds, our findings also facilitate the development of MALDI-MSI-based metabolomics as a novel effective molecular imaging tool for evaluating the spatial distribution of endogenous compounds.

Development of a multi-stage model for intelligent and quantitative appraising of skeletal maturity using cervical vertebras cone-beam CT images of Chinese girls.

PURPOSE: Nowadays, the integration of Artificial intelligence algorithms and quantified radiographic imaging-based diagnostic procedures is hailing amplified deliberation particularly in assessment of skeletal maturity. So we intend to formulate a logistic regression model for intelligent and quantitative estimation of Fishman skeletal maturation index (SMI) based on the parameters attained from the cervical vertebrae CBCT images of Chinese girls. METHODS: From 709 hand wrist radiographs and CBCT images, 447 samples were randomly selected (called as G1) to build a logistic regression model. The reliability and reproducibility were assessed by the intraclass correlation coefficient (ICC) and weighted Cohen's kappa, followed by Spearman's rank correlation coefficient to identify the parameters significantly associated with the SMI. Two hundred and sixty-two other subjects (named G2) were recruited for external examination of the models by direct visual comparison and the receiver operating characteristic (ROC) curve. In cases of confusion and mispredictions, the model was modified to improve the consistency. RESULTS: Five significant parameters (Chronological age, C3 height (H3)[Formula: see text], C4 upper width (UW4), C4 lower width (LW4), and the ratio of posterior height to lower width of C4 ([Formula: see text]) were administered into logistic regression model. Despite total agreement percentage which was 84% (total AUC = 0.92), unsatisfactory performance was noticed for the 6th and 8th stages which were confused with their neighboring stages. After adjustments of the models, the total agreement percentage and AUC were upgraded to 88% and 0.96, respectively. CONCLUSION: Consistency and fitness evaluation of our models demonstrated adequate prediction percentage and reliability for automated classification of skeletal maturation. The presented constructed logistic regression model has the potential to serve as a maturity evaluation index in clinical craniofacial orthopedics in Chinese girls. The proposed model in this study showed promising strength for being expended in the event of other clinical multi-stage conditions.

Intelligent quantitative assessment of skeletal maturation based on multi-stage model: a retrospective cone-beam CT study of cervical vertebrae.

OBJECTIVE: To develop new logistic regression estimative models of the cervical vertebral maturation index (CVMI) based on cone-beam CT (CBCT)-derived parameters for intelligent evaluating skeletal maturation. METHODS: From 231 CBCT volumes (age range 7-17, mean age 11.09 years), 154 were randomly selected to produce 2D sagittal projections of the second to fourth cervical vertebrae (C2-C4). From 19 quantitative parameters, significant predictors were deduced to formulate logistic models. Using the CVMI and significant predictors of 77 other subjects, performance of the models was externally examined by direct comparison and the area under the receiver operating characteristic curve (AUC). Models were modified if required, to improve their accuracy. RESULTS: Chronological age, C3 height ([Formula: see text], and ratio of posterior height to lower width of C4 [Formula: see text] were entered as significant predictors. Accuracy of the models was acceptable (total AUC = 0.91) except for 4th and 5th stage (AUC of 0.82 and 0.83, respectively), which were mis-predicted inversely. Adjusted models were generated by bivariate logistic regression analysis and adding significant parameters ([Formula: see text] and [Formula: see text], with odds ratios of 3.308 and 3.38, respectively) from 58 subjects in 4th and 5th stages of CVMI in the model establishment group. The total AUC increased to 0.94, along with an increase in the accuracy of the latter optimized models to 77.9 and 87%, respectively. CONCLUSION: The new intelligent models reliably estimated skeletal maturation and can be utilized in the clinical field or machine learning-based skeletal maturation assessment.

Accuracy of three-dimensional photogrammetry and cone beam computed tomography based on linear measurements in patients with facial deformities.

OBJECTIVES: This study was aimed to investigate the accuracy of soft-tissue measurements obtained by two imaging modalities, three-dimensional (3D) photogrammetry and cone beam CT (CBCT) when confounded by influence factors (facial deformities and partitions). METHODS: 60 wax facial models from facially deformed patients were captured by 3D photogrammetry and CBCT. 19 linear distances on each image were measured and juxtaposed to reference values attained via a coordinate-measuring machine (CMM) as the gold-standard. Paired t-tests were used to compare linear accuracy of the test and reference systems. The influence of deformities and partitions (created by dividing the face with three vertical and five horizontal lines) on the measurement errors were analyzed by independent sample t-test and one-way ANOVA. RESULTS: Statistically significant differences were found between linear accuracy of the test and reference systems. The test values obtained by 3D photogrammetry were closer to the reference values than CBCT's. 3D photogrammetry's measurement errors were significantly higher in deformed areas, unlike CBCT's. Both systems reported significantly lower errors within partitions 8 and 13 compared to other partitions; for CBCT, aside from partitions 8 and 13, the differences in the errors for partitions 6 and 10 were significant compared to partitions 8, 12, 13, 14. CONCLUSION: 3D photogrammetry showed a higher linear accuracy than CBCT in patients with facial deformities due to protuberances. Facial reconstruction by both test modalities was significantly influenced in different facial partitions, but facial deformities extensively affected the results from 3D photogrammetry.

[Accuracy of three-dimensional camera system based on stereophotography on photographic acquisition of deformity facial images].

OBJECTIVE: To evaluate and analyze the accuracy of three-dimensional camera system acquisition based on stereophotography for the photographic acquisition of images of facial deformities. METHODS: 3D digital models of 45 waxen facial models of patients with facial deformities were obtained via a 3D camera system based on stereophotography. A total of 19 feature lines were measured on each 3D model by using the software. The measurements taken by the coordinate-measuring machine were accepted as standard values. Statistical analysis was performed to evaluate the accuracy of the system and the corresponding factors. RESULTS: Statistical analysis results showed that the measured values of the characteristic distance obtained by 3D camera system were statistically different from the standard values (P<0.001). Convex deformities had significant influence on the measuring error of 3D camera system (P<0.05), while cleft deformities had no significant influence on the measuring error (P>0.05). The facial regions significantly influenced measuring error (P<0.05). The deformities had no significant influence on the percentage of measurement values (P>0.05). The middle facial regions had significant difference with bilateral facial regions on the percentage of measurement values (P<0.05), while the left and right facial regions had no significant difference (P>0.05). CONCLUSIONS: The accuracy of 3D camera system based on stereophotography for the photographic acquisition of facial deformities are influenced by the morphology of the facial deformities and facial regions. Moreover, the measuring error is acceptable in clinical settings.

Surgical treatment for bacterial meningitis after spinal surgery: A case report.

RATIONALE: Bacterial meningitis (BM) has been recognized as a rare complication of spinal surgery. However, there are few reports on the management of postoperative BM in patients who have undergone spinal surgery. The initial approach to the treatment of patients suspected with acute BM depends on the stage at which the syndrome is recognized, the speed of the diagnostic evaluation, and the need for antimicrobial and adjunctive therapy. PATIENT CONCERNS: Here, we report the case of a patient with lumbar spinal stenosis and underwent a transforaminal lumbar interbody fusion at L4-L5. The dura mater was damaged intraoperatively. After the surgery, the patient displayed dizziness and vomiting. A CSF culture revealed Pseudomonas aeruginosa infection. DIAGNOSES: The patient was diagnosed with postoperative BM. INTERVENTIONS: Antibiotic was administered intravenously depends on the organism isolated. Nevertheless, the patient's clinical condition continued to deteriorate. The patient underwent 2 open revision surgeries for dural lacerations and cyst debridement repair. OUTCOMES: The patient's mental status returned to normal and her headaches diminished. The patient did not have fever and the infection healed. LESSONS: Surgical intervention is an effective method to treat BM after spinal operation in cases where conservative treatments have failed. Further, early surgical repair of dural lacerations and cyst debridement can be a treatment option for selected BM patients with complications including pseudomeningocele, wound infection, or cerebrospinal fluid leakage.