New Monomer Capable of Dual Chemical Binding with Dentin to Improve Bonding Durability.

The water-rich nature of the dentin bonding microenvironment, coupled with the stresses on the bonding interface, contributes to the hydrolytic degradation of the hybrid layer, resulting in a decline in bonding durability and, ultimately, restoration failure. Currently, the 3-step etch-and-rinse technique remains the gold standard for dentin bonding, and the bonding mechanism mainly involves a physical interaction with little chemical bonding. In this study, we have developed a siloxane-modified polyurethane monomer (SPU) with acrylate and siloxane modifications that chemically binds to both collagen and hydroxyapatite in dentin. Formulated as a bisphenol A-glycidyl methacrylate alternative, the SPU monomer-based adhesive was designed to improve dentin bonding quality and durability. Attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscope, and hydroxyproline release assays were performed on SPU-treated collagen, hydroxyapatite, and acid-etched dentin slices to dentin. The physicochemical properties of the configured SPU adhesives were profiled for polymerization behavior, water contact angle, and tensile strain and strength. The bonding effectiveness was assessed through micro-tensile strength, nano-leakage tests conducted on the bonded samples before and after thermal cycle aging. Finally, we further conducted in vivo and in vitro experiments to assess the biocompatibility of adhesives. The results showed that the siloxane groups of SPU monomer could covalently bind to dentin collagen and hydroxyapatite. The incorporation of SPU in the adhesive led to a significant increase in adhesive polymerization (P < 0.05) and tensile strain at break up to 134.11%. Furthermore, the SPU adhesive significantly improved dentin bond strength (P < 0.05), reduced interfacial nano-leakage (P < 0.05), and displayed good biocompatibility. In conclusion, the application of SPU, which achieves dual chemical bonding with dentin, can improve the quality of the hybrid layer, buffer the interfacial stresses, enhance the interfacial resistance to hydrolysis, and provide a feasible strategy to extend the service life of adhesive restorations.

Effect of Collagen-Reactive Functional Monomer on Etch-and-Rinse Adhesives.

In this study, we evaluated a novel functional monomer (4-formylphenyl acrylate [FA]) that can specifically and covalently bind to the dentin collagen matrix as a potential alternative hydrophobic diluent-like monomer for improving the durability of dentin bonding. Experimental adhesives with different FA contents (0%, 10%, 20%, and 30%) were evaluated as partial substituents for the hydrophilic monomer 2-hydroxyethyl methacrylate, with the commercial adhesive One-Step (Bisco, Inc.) employed as the positive control. Their degree of conversion, viscosity, hydrophobicity, mechanical properties, and water absorption/solubility were measured as the comprehensive characterization. In situ zymographic assays were performed to determine the extent to which FA inhibits the endogenous hydrolytic activity of dentin. Finally, the bonding performances of the novel adhesives were evaluated with microtensile strength tests and scanning electron microscopy. The results showed that the incorporation of FA significantly improved the mobility of experimental adhesives attributable to the dilution property of FA. In contrast to the possible compromised rate of polymerization by hydroxyethyl methacrylate, FA exhibited typical characteristics of favorable copolymerization with polymerizable monomers in adhesives and improved the degree of conversion of experimental adhesives. The rigidity and hydrophobic properties of the phenyl framework of the FA molecule conferred superior mechanical properties and hydrolysis resistance to the novel experimental adhesives. An inhibitory effect on gelatinolytic activities within the hybrid layer was also observed in the in situ zymographic assays, even at a low FA concentration (10%). In conjunction with the significantly improved infiltration found via scanning electron microscopy, the experimental adhesives containing FA possessed significantly better-maintained microtensile strength, even after aging. Thus, the incorporation of this novel monomer endowed the experimental adhesives with multiple enhanced functionalities. These remarkable advantages highlight the suitability of the monomer for further applications in clinical practice.

[Electronic cigarette use-associated lung injury: a case report and literature review].

Objective: To improve the clinical recognition of electronic cigarette or vaping product use-associated lung injury. Methods: A 67 year old patient with lung injury induced by e-cigarette was reported. The concentrations of vitamin E acetate (VEA) and tetrahydrocannabinol (Δ9-THC) in BALF were measured by UHPLC-MS/MS. A literature review was performed with"Vaping-Associated Lung Injury""vape","e-cigarette","electronic cigarette","EVALI","electronic nicotine device","lung","injury","case"as Mesh terms in PubMed. Results: There were 208 cases reported in the literature, 71.6% of whom were male, and 28.4% were female, with a median age of 27 years (17-67 years), while 2 patients (1%) were over 60 years old. The median time of using e-cigarette was 90 days (2 weeks-3 years). Of the 208 patients, the most common symptoms were dyspnea, fever, chest pain, hemoptysis, and gastrointestinal symptoms such as nausea, abdominal pain or diarrhea. The most common manifestation of chest CT was bilateral ground glass opacity (n=119, 57.2%). A total of 70 patients received bronchoscopy and BALF, which showed that the ratio of macrophages was (49.5±29.8)%, neutrophil (34.7±28.7)%, lymphocytes (10.1±7.4)%, and eosinophils (2.4±3.6)%. The "foamy" alveolar macrophages were positive in 65 cases (92.9%).A total of 132 patients (63.5%) were treated with antibiotics, and 162 patients (77.9%) were treated with glucocorticoids. The initial dose of methylprednisolone was 40 mg and the maximum was 500 mg. 48 patients (23.1%) were mechanically ventilated and 10 patients (4.8%) were treated with extracorporeal membrane oxygenation (ECMO). Of the 208 patients, 202(97.1%) patients improved and 6 (2.9%) died. Conclusion: Our case and reported cases should alert physicians to the clinical presentation of vaping-associated lung injury for early diagnosis and prompt management. It is suggested that the standardized management of e-cigarette should be strengthened to avoid similar situation of e-cigarette-related lung injury in China. Additional work is needed to characterize the pathophysiology of this disease.

[Research Status of Postmortem MSCT Angiography in Forensic Science].

ABSTRACT: Virtual autopsy is a new technique for investigating the morphological changes of cadaveric tissues and organs by medical imaging technology. It has been widely used in the identification of causes of death. Multislice spiral computed tomography （MSCT） has become a routine inspection method in some identification institutions, although it cannot completely replace traditional autopsy, it plays a key auxiliary or substitute role in the identification of certain abnormal causes of death. Plain MSCT scan cannot visualize cadaveric vessels, but can perform cadaveric angiography to determine vascular injury or disease. This technology has entered a rapid development period in recent years, and has made a considerable progress in contrast agent, perfusion methods and imaging methods. This article summarizes several common cadaveric MSCT angiography methods, such as systemic angiography, angiography through cardiopulmonary resuscitation, targeted angiography, and angiography by cardiac puncture, and analyzes and compares the application prospects.

[Application of biological factor in cementum regeneration].

At the present day, curettage and periodontal surgery comprise the main strategy for the treatment of periodontitis, however, these methods are limited in regenerating cementum. It has been found that some biological factors such asenamel matrix derivative (EMD), transforming growth factor-ß (TGF-ß) and insulin-like growth factor (IGF) could promote cementum regeneration. In the cementum regenerationstudies, there has been a lack of criteria to distinguish cementum from alveolar bone and other types of cementum. Therefore, this article will briefly review the biological factors that affect the cementum regeneration and the molecular markers used to judge the regenerating cementum.

Relationship between Changes of Pericyte Number and Wound Age during Repair of Skeletal Muscle Contusion in Mice.

ABSTRACT: Objective To observe the change pattern of pericyte number at different time periods after mice skeletal muscle contusion and discuss its role in wound age estimation. Methods A mice gastrocnemius muscle contusion model was established. The form and number changes of pericytes at 1, 3, 5, 7, 9, 14, and 28 d post-injury were detected by multiple immunofluorescence staining. Results Compared with the slender shape of pericytes in normal skeletal muscles, pericytes in the contusion area had increased volume, rounder form and a round nuclei. Part of pericytes were found to express satellite cell markers paired-box transcription factor （Pax7） or myoblast determination 1 （MyoD1）. The changes of pericyte number in skeletal muscles after contusion were time-dependant, and showed unimodal distribution with the extension of wound age. In the central contusion area, the number of pericytes peaked at 5 d post-injury while in the peripheral contusion area, the number of pericytes peaked at 5 d and 7 d post-injury. Conclusion The number of pericytes in contusion area varies time-dependently after skeletal muscle contusion in mice and might be a reference index for muscle wound age estimation, and is involved in the repair and regeneration of skeletal muscle injury.

Clinicopathological and prognostic significance of miR-4317 expression in gastric cancer patients.

OBJECTIVE: Previous studies have revealed that miR-4317 was abnormally expressed and functioned as a tumor suppressor in several tumors, including gastric cancer (GC). However, the clinical significance of miR-4317 in GC remains largely unclear. Our present study aimed at investigating the possibility of miR-4317 as a novel prognostic biomarker for GC patients. PATIENTS AND METHODS: RT-PCR was performed to determine the levels of miR-4317 in GC tissues and matched normal gastric tissues. Association between miR-4317 levels and clinicopathological factors was also analyzed using Chi-square test. Kaplan-Meier survival analysis and univariate and multivariate assays were further conducted to investigate the correlation between miR-4317 expression and GC patients prognosis. RESULTS: We showed that miR-4317 expression levels were significantly lower in GC cell lines compared to matched normal tissues (p< 0.01). Down-regulation of miR-4317 was observed to be associated with lymph node metastasis (p = 0.019), distant metastasis (p = 0.011) and TNM stage (p = 0.007). In addition, Kaplan-Meier analysis showed that patients with low miR-4317 expression had a shorter overall survival compared with the high miR-4317 expression group (p = 0.0009). Furthermore, multivariate analysis revealed that miR-4317 expression was an independent prognostic marker of overall survival of GC patients. CONCLUSIONS: miR-4317 expression may be a novel and valuable prognostic factor in GC.

MicroRNA-791 is an independent prognostic factor of papillary thyroid carcinoma and inhibits the proliferation of PTC cells.

OBJECTIVE: To investigate the significance and possible mechanism of miR-791 in the pathogenesis of papillary thyroid carcinoma (PTC). PATIENTS AND METHODS: The expression of miR-791 in 80 cases of thyroid carcinoma tissues and 80 cases of paracancerous tissues was detected by quantitative Real-time-polymerase chain reaction (qRT-PCR). After miR-791 mimics were transfected into thyroid cancer cells by liposome method, the cell proliferation was detected by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EDU), respectively. Cell cycle was detected by flow cytometry. RESULTS: The expression of miR-791 in thyroid cancer tissue was significantly lower than that of normal thyroid. The mir-719 expression is positively correlated with the prognosis of thyroid carcinoma. After transfection of miR-791 mimics, the proliferation ability of TPC-1 and HTH83 cells was weakened, and the cell cycle was blocked in the G0/G1 phase. Further study on the underlying mechanism found that after overexpression of miR-791, the expressions of Cyclin D1, CKD6 and CDK4 decreased significantly, while the expression of cyclin inhibitor P21 increased significantly. CONCLUSIONS: MiR-791 is lowly expressed in thyroid cancer. MiR-791 may inhibit thyroid cancer cell proliferation by blocking thyroid cancer cells in G0/G1 phase, thus participating in the impediment of thyroid cancer development.

Selective retention of the great saphenous vein to prevent saphenous nerve injury during varicose vein surgery.

OBJECTIVE: To explore the selective retention of the great saphenous vein trunk below the knee to prevent saphenous nerve injury during varicose vein surgery. PATIENTS AND METHODS: This research was a single-center prospective randomized trial. From January 2009 to January 2012, 280 patients of varicose veins in the great saphenous vein were treated and divided into two groups of 140 cases each. In the observation group, the vascular trunk of the great saphenous vein was stripped to below the knee level whilst that in the control group, it was stripped to the ankle level. Patients in both groups were treated with a transilluminated powered phlebectomy (TIPP) and foam sclerotherapy. Primary end points were postoperative pain, saphenous nerve injury, quality of life and recurrence rate. RESULTS: After one month follow-up: 5.71% of patients in the observation group had neurological symptoms, while 14.29% of patients had neurological symptoms in the control group. The saphenous nerve injury between the two groups was statistically significant. Postoperative follow-up of one year, 1.47% patients had symptoms of neurological disorders in the observation group, while 7.14% patients had symptoms of neurological disorders in the control group. The saphenous nerve injury between the two groups was statistically significant. Therefore,  selective retention of great saphenous vein below-knee can prevent saphenous nerve injury. The main outcome measures were postoperative pain, missing saphenous nerve, improvement of symptoms and the incidence of recurrence. The follow-up after one month showed that the percentage of neurological symptoms in the observation group and the control group was 5.71% and 14.29% respectively, and the saphenous nerve injury showed a statistical difference. The follow-up after one year showed 1.47% of abnormal sensation in the observation group and 7.14% of dysesthesia or paresthesia in the control group in surgical limb according to subjects' claims, and there existed a statistical difference in the saphenous nerve injury. CONCLUSIONS: The selective retention of the great saphenous vein trunk below the knee can prevent the saphenous nerve injury.