Mechanical Comparison of a Novel Hybrid and Commercial Dorsal Double Plating for Distal Radius Fracture: In Vitro Fatigue Four-Point Bending and Biomechanical Testing.

This study compares the absolute and relative stabilities of a novel hybrid dorsal double plating (HDDP) to the often-used dorsal double plating (DDP) under distal radius fracture. The "Y" shape profile with 1.6 mm HDDP thickness was obtained by combining weighted topology optimization and finite element (FE) analysis and fabricated using Ti6Al4V alloy to perform the experimental tests. Static and fatigue four-point bending testing for HDDP and straight L-plate DDP was carried out to obtain the corresponding proof load, strength, and stiffness and the endurance limit (passed at 1 × 106 load cycles) based on the ASTM F382 testing protocol. Biomechanical fatigue tests were performed for HDDP and commercial DDP systems fixed on the composite Sawbone under physiological loads with axial loading, bending, and torsion to understand the relative stability in a standardized AO OTA 2R3A3.1 fracture model. The static four-point bending results showed that the corresponding average proof load values for HDDP and DDPs were 109.22 N and 47.36 N, that the bending strengths were 1911.29 N/mm and 1183.93 N/mm, and that the bending stiffnesses were 42.85 N/mm and 4.85 N/mm, respectively. The proof load, bending strength and bending stiffness of the HDDPs were all significantly higher than those of DDPs. The HDDP failure patterns were found around the fourth locking screw hole from the proximal site, while slight plate bending deformations without breaks were found for DDP. The endurance limit was 76.50 N (equal to torque 1338.75 N/mm) for HDDP and 37.89 N (equal to torque 947.20 N/mm) for DDP. The biomechanical fatigue test indicated that displacements under axial load, bending, and torsion showed no significant differences between the HDDP and DDP groups. This study concluded that the mechanical strength and endurance limit of the HDDP was superior to a commercial DDP straight plate in the four-point bending test. The stabilities on the artificial radius fractured system were equivalent for novel HDDP and commercial DDP under physiological loads in biomechanical fatigue tests.

Chlorotrimethylsilane promoted one-flask heterocyclic synthesis of 1,2,4-triazoles from nitrilimines: Modeling studies and bioactivity evaluation of LH-21 and Rimonabant analogues.

An efficient one-flask cascade method for synthesis of the multi-substituted 1,2,4-triazoles via chlorotrimethylsilane as a promoter was developed. Firstly, nitrilimines were transformed to hydrazonamides as intermediate in high yield by treatment with commercially available hexamethyldisilazane. Subsequently, the mixture was added with corresponding acyl chloride and heated in the presence of pyridine to give the corresponding multi-substituted 1,2,4-triazoles via chlorotrimethylsilane promoted heterocyclization reaction. The utility of method was demonstrated to synthesize CB1 ligands including Rimonabant analogue 4c and LH-21 3 for modeling study. All synthesized compounds were subjected to the cAMP functional assay of CB1/CB2 receptor. Especially, compound 4g enhanced the reversal of cAMP reduction by CP59440 than LH-21 and Rimonabant analogue in CHO-hCB1 cells. In addition, the docking results showed compound 4g fits the best position with CB1 receptor. However, the ability to penetrate brain-blood barrier of compound 4g is similar with Rimonabant in MDCK-mdr1 permeability assay, which might cause CNS side effect. This study still provides the basis for further development of a potent and specific CB1 antagonist.

Lack of associations between the FTO polymorphisms and gestational diabetes: A meta-analysis and trial sequential analysis.

BACKGROUND: Molecular epidemiological studies have sought associations between Fat mass and obesity associated (FTO) gene polymorphisms and gestational diabetes mellitus (GDM) risk, but findings are inconsistent. Hence, we performed a meta-analysis to clarify this problem. METHODS: Case-control studies reporting the relationship of three FTO polymorphisms (rs9939609, rs8050136, and rs1421085) and GDM published before June 2018 were searched in 6 electronic databases such as PubMed and Embase. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Trial sequential analysis (TSA) was performed to evaluate the type 1 and type 2 errors. RESULTS: A total of 5 studies involving 703 GDM cases and 2700 controls for rs9939609, 3 studies involving 1144 GDM cases and 909 controls for rs8050136, and 2 studies involving 207 GDM cases and 205 controls for rs1421085, were included in the meta-analysis. No association was observed between the three polymorphisms with the GDM risk under all genetic models. For example, the ORs and its 95% CIs under dominant genetic model were 0.88 (0.59, 1.33) for rs9939609, 1.11 (0.91, 1.35) for rs8050136, and 0.91 (0.58, 1.41) for rs1421085, respectively. Under TSA, there are insufficient levels of evidence for all of these three polymorphisms. CONCLUSION: The present meta-analysis provides statistical evidence indicating a lack of association between FTO polymorphismsand GDM risk. More studies with larger sample size are needed to confirm these null associations.

Narrow-band imaging: a novel screening tool for early nasopharyngeal carcinoma.

OBJECTIVE: To compare the real-time diagnostic accuracy of conventional white-light imaging (WLI) endoscopy with that of narrow-band imaging (NBI) endoscopy in patients at high risk for nasopharyngeal carcinoma (NPC). DESIGN: Prospective study. SETTING: A university tertiary care center. PATIENTS: From July 28 through October 27, 2009, a total of 211 consecutive patients at high risk for NPC were enrolled. A high-performance endoscopic system equipped with WLI and NBI modes was used for a detailed examination of the nasopharynx during the same endoscopy. MAIN OUTCOME MEASURES: Diagnostic efficacies of WLI and NBI were compared with pathologic findings. Lesions were classified according to the detailed morphologic epithelial microvessel observations during NBI. RESULTS: A total of 285 lesions were detected, including 66 cancerous lesions. The sensitivity and negative predictive values of NBI in NPC screening were significantly higher than those of WLI (93.9% vs 71.2%, P = .001; and 98.1% vs 91.7%, P = .003; respectively); specificity and positive predictive value were not significantly different. During NBI, the presence of superficial, distorted, irregularly shaped microvessels indicated malignant lesions; 53 of 55 lesions (96.4%) with type IV intrapapillary capillary loops were confirmed on histologic testing as malignant. The false-negative and false-positive rates for NBI were 4.5% and 3.6%, respectively. CONCLUSIONS: Narrow-band imaging endoscopy is a promising tool to differentiate nonmalignant from malignant nasopharyngeal lesions on the basis of the morphologic findings of mucosal capillary vessels in vivo. In addition, NBI may increase the diagnostic value of endoscopy in populations at high risk for NPC.

Endoscopic nasopharyngectomy for salvage in nasopharyngeal carcinoma: a novel anatomic orientation.

OBJECTIVES/HYPOTHESIS: Nasopharyngectomy for residual/recurrent nasopharyngeal carcinoma (NPC) using an endoscopic technique is less invasive than traditional methods. Our objective was to identify the important anatomic landmarks so that the endoscopic surgeon can avoid injury to the internal carotid artery and perform a nasopharyngectomy safely. STUDY DESIGN: Anatomical study. METHODS: Transnasal endoscopic dissection was carried out on three fresh adult cadaver specimens (six sides) after arterial latex injection. Measurements were made in 50 adult skulls (100 sides), detailing the distances between orienting critical landmarks and the internal carotid canal (external aperture). RESULTS: Adequate exposure for endoscopic nasopharyngectomy is available by removing portions of the inferior turbinate, nasal septum, and medial pterygoid plate. Anatomy of the operative field (endoscopic view) is described. Orientating topical landmarks include: posterior portions of the inferior turbinate and nasal septum, fossa of Rosenmuller, and the torus tubarius. The deep landmarks include: medial pterygoid plate-posterior margin at the skull base, eustachian tube isthmus, foramen lacerum, and the longus capitis. All topical and deep landmarks were identified from the endoscopic point of view and their distances to the internal carotid canal (external aperture) were measured. CONCLUSIONS: This anatomic study provides novel orienting landmarks for endoscopic nasopharyngectomy. Surgeons can efficiently and safely deal with residual and/or recurrent NPC endoscopically.

[Rapid eye movement-related and none rapid eye movement-related classification in obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To study the value of a new measurement that divided obstructive sleep apnea-hypopnea syndrome (OSAHS) into rapid-eye-movement (REM) related and non-rapid-eye-movement (NREM) related subgroups. METHODS: According to Siddiqui classification, 137 adult patients with OSHAS were diagnosed as REM-related OSAHS [REM apnea hypopnea index (AHI)/NREM AHI > 1] or NREM-related OSAHS (REM AHI/NREM AHI < 1). Polysomnographic data were compared and discussed. RESULTS: (1) There were 72 cases defined as REM-related OSAHS (52.6%) and 65 cases defined as NREM-related OSAHS (47.4%). (2) In all cases, total AHI and NREM AHI in REM-related OSAHS were significantly lower than those in NREM-related OSAHS, while lowest arterial oxygen saturation (LSaO2), REM LSaO2 and NREM LSaO2 were significantly higher than those in NREM-related OSAHS (t were -6.466, -7.638, 3.426, 2.472, 4.873 respectively, P < 0.05). No significance was found in sleep structure, REM AHI and REM LSaO2 between REM-related and NREM-related OSAHS (P > 0.05). (3) Given the severity of OSHAS, the constituent ratio of REM-related OSAHS decreased (77.8%, 61.5%, 37.3%) from mild to severe OSAHS, while that of NREM-related OSAHS rose (22.7%, 38.5%, 62.7%; chi² = 16.996, P < 0.01). In mild and moderate groups, REM LSaO2 of REM-related OSAHS was significantly lower than those in NREM-related OSAHS (t were -4.273 and -2.136, P < 0.05), while the differences of total AHI and LSaO2, NREM LSaO2 between these two types were not significant. In severe group, AHI in NREM-related OSAHS was significantly higher than that in REM-related OSAHS, while LSaO2, REM LSaO2 and NREM LSaO2 was significantly lower than those in REM-related OASHS (t were -4.943, 2.574, 1.996, 3.571, P ≤ 0.05). (4) There was no significance in sleeping latency and efficiency between REM-related and NREM-related OSHAS. CONCLUSIONS: REM-related OSHAS mainly exists in mild and moderate OSHAS, while NREM-related one mainly exists in severe OSHAS. NREM-related OSAHS may be more severe in AHI and hypoxia than REM-related one. Whenever obstructive apnea happened in REM or NREM period, its impacts on sleep structure, efficiency and latency have no difference.