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-β (TGF-β) 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.