Periodontitis is associated with stroke.

BACKGROUND: Periodontitis is considered as a risk factor for cardiovascular diseases and atherosclerosis. However, the relationship between periodontitis and stroke is rarely studied. Therefore, we aimed to explore the relationship between periodontitis and stroke. METHODS: Statistical analysis was performed using the complex sampling design. We analyzed data on 6,460 participants, representing 92,856,028 American citizens aged 30 years or older, who had valid data on periodontitis and stroke from the National Health and Nutrition Examination Survey 2009-2014. We used clinical attachment level and probing pocket depth precisely to determine periodontitis and it is the first time to use such a precise method for exploring the relationship between periodontitis and stroke. RESULTS: 39.9% of participants had periodontitis and 2.1% of participants had a record of stroke diagnosis. Stroke was associated with severity levels of periodontitis (p for trend = 0.018). The odds ratio for stroke was significantly elevated in the severe periodontitis and moderate periodontitis participants compared to participants without periodontitis (OR for severe periodontitis: 2.55, 95% CI 1.25-5.21; OR for moderate periodontitis: 1.71, 95% CI 1.17-2.50). After adjusting for race/ethnicity and sex, the association remained significant (p for trend = 0.009). After further adjusting for BMI, hypercholesterolemia, diabetes, alcohol consumption and physical activity, the association still existed (p for trend = 0.027). The association was significant consistently after further adjusting for age (p for trend = 0.033). CONCLUSIONS: In this nationally representative study, we found an association between periodontitis and stroke. The risk of stroke in participants with severe periodontitis and moderate periodontitis was 2.55 times and 1.71times as high as those without periodontitis. Dental health management may be of benefit to stroke prevention.

A keratin/chitosan sponge with excellent hemostatic performance for uncontrolled bleeding.

Uncontrolled bleeding leads to a higher fatality rate in the situation of surgery, traffic accidents and warfare. Traditional hemostatic materials such as bandages are not ideal for uncontrolled or incompressible bleeding. Therefore, it is of great significance to develop a new medical biomaterial with excellent rapid hemostatic effect. Keratin is a natural, biocompatible and biodegradable protein which contains amino acid sequences that induce cell adhesion. As a potential biomedical material, keratin has been developed and paid attention in tissue engineering fields such as promoting wound healing and nerve repair. Herein, a keratin/chitosan (K/C) sponge was prepared to achieve rapid hemostasis. The characterizations of K/C sponge were investigated, including SEM, TGA, liquid absorption and porosity, showing that the high porosity up to 90.12 ± 2.17 % resulted in an excellent blood absorption. The cytotoxicity test and implantation experiment proved that the K/C sponge was biocompatible and biodegradable. Moreover, the prepared K/C sponge showed better hemostatic performance than chitosan sponge (CS) and the commercially available gelatin sponge in both rat tail amputation and liver trauma bleeding models. Further experiments showed that K/C sponge plays a hemostatic role through the endogenous coagulation pathway, thus shortening the activated partial thromboplastin time (APTT) effectively. Therefore, this study provided a K/C sponge which can be served as a promising biomedical hemostatic material.

Digital Light Processing-Based 3D Printing of Cell-Seeding Hydrogel Scaffolds with Regionally Varied Stiffness.

Cell-seeding heterogeneous scaffolds with regionally varied stiffness play an important role in tissue engineering, e.g., bone and cartilage regeneration, that require the recapitulation of geometric complexity through biocompatible material to mimic the natural cell microenvironment in vivo. Here, we report the digital light processing (DLP)-based 3D printing of cell-seeding hydrogel scaffold with regionally varied stiffness by tuning the exposure time without changing the geometric architecture. Mechanical tests on printed poly(ethylene glycol) diacrylate (PEGDA) hydrogels homogeneous scaffold revealed that a 60% increase in the elastic modulus can be achieved by setting the optimal exposure time. Furthermore, regulating the stiffness by varying the exposure time was demonstrated in the printed three-sectional heterogeneous scaffolds. Uniaxial compression tests showed that no fracture was observed even when the compression strain reached up to 25%, indicating that by adjusting the exposure time, the undesired influence of the scaffold on mechanical integrity could be avoided. 3T3 fibroblasts were then seeded onto the scaffold, and the biocompatibility together with the physical support of the scaffolds were confirmed by observation and cell population assessment.

Simvastatin increases cell viability and suppresses the expression of cytokines and vascular endothelial growth factor in inflamed human dental pulp stem cells in vitro.

BACKGROUND: In recent years, simvastatin has been demonstrated to be capable of inducing odontogenic differentiation in human dental pulp stem cells (DPSCs), which makes it a promising source for endodontic treatment in pulpitis. However, a comprehensive understanding of how simvastatin affects the behavior of DPSCs and its potential in pulpitis is still lacking. OBJECTIVES: In this study, we investigated the effects of simvastatin on the viability of inflamed DPSCs. The expression of cytokines and vascular endothelial growth factor (VEGF) was also studied in response to simvastatin treatment. MATERIAL AND METHODS: We characterized the cell viability, inflammatory reactions and the production of VEGF in inflamed DPSCs, induced by lipopolysaccharides (LPS). The methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, cell cycle, apoptosis analysis, quantitative reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and western blot analyses were performed. RESULTS: We observed that a low dosage of simvastatin accelerated cell proliferation , whereas its high dosage (>15 µg/mL) suppressed propagation. A simvastatin dose of 8 µg/mL was sufficient to promote cell growth and cell cycle progression in DPSCs treated with LPS. Meanwhile, simvastatin induced apoptosis. The expression of multiple cytokines, including interleukins (IL)-1, IL-4 and IL-1ß, and especially interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), was significantly suppressed. Moreover, the protein secretion and mRNA transcription of VEGF was observed to be markedly inhibited by simvastatin by inactivating mitogen-activated protein kinase (MAPK) signaling. CONCLUSIONS: Taken together, these results suggested that simvastatin might be a potent ingredient to enhance cell proliferation, alleviate inflammation response and attune vasculogenesis in pulpitis.

Projection-Based 3D Printing of Cell Patterning Scaffolds with Multiscale Channels.

To fully actualize artificial, cell-laden biological models in tissue engineering, such as 3D organoids and organs-on-a-chip systems, cells need to be patterned such that they can precisely mimic natural microenvironments in vitro. Despite increasing interest in this area, patterning cells at multiscale (∼10 µm to 10 mm) remains a significant challenge in bioengineering. Here, we report a projection-based 3D printing system that achieves rapid and high-resolution fabrication of hydrogel scaffolds featuring intricate channels for multiscale cell patterning. Using this system, we were able to use biocompatible poly(ethylene glycol)diacrylate in fabricating a variety of scaffold architectures, ranging from regular geometries such as serpentine, spiral, and fractal-like to more irregular/intricate geometries, such as biomimetic arborescent and capillary networks. A red food dye solution was able to freely fill all channels in the scaffolds, from the trunk (>1100 µm in width) to the small branch (∼17 µm in width) without an external pump. The dimensions of the printed scaffolds remained stable over 3 days while being immersed in Dulbecco's phosphate-buffered saline at 37 °C, and a penetration analysis revealed that these scaffolds are suitable for metabolic and nutrient transport. Cell patterning experiments showed that red fluorescent protein-transfected A549 human nonsmall lung cancer cells adhered well in the scaffolds' channels, and showed further attachment and penetration during cell culture proliferation.

Combined Orthodontic-surgical Treatment for Skeletal Class III Malocclusion with Multiple Impacted Permanent and Supernumerary Teeth: Case Report.

In this report we describe a combined orthodontic and surgical treatment for a 14-year-old boy with severe skeletal class III deformity and dental problem. His upper posterior primary teeth in the left side were over-retained and 6 maxillary teeth (bilateral central incisors and canines, left first and second premolars) were impacted, together with 5 supernumerary teeth in both arches. The treatment protocol involved extraction of all the supernumerary and deciduous teeth, surgical exposure and orthodontic traction of the impacted teeth, a bimaxillary orthognathic approach including Lefort I osteotomy. Bilateral sagittal split ramus osteotomy (BSSRO) and genioplasty was performed to correct skeletal problem. After treatment, all of the impacted teeth were brought to proper alignment in the maxillary arch. A satisfied profile and good posterior occlusion was achieved. Treatment mechanics and consideration during different stages are discussed.

Expression of SET Protein in the Ovaries of Patients with Polycystic Ovary Syndrome.

Background. We previously found that expression of SET gene was up-regulated in polycystic ovaries by using microarray. It suggested that SET may be an attractive candidate regulator involved in the pathophysiology of polycystic ovary syndrome (PCOS). In this study, expression and cellular localization of SET protein were investigated in human polycystic and normal ovaries. Method. Ovarian tissues, six normal ovaries and six polycystic ovaries, were collected during transsexual operation and surgical treatment with the signed consent form. The cellular localization of SET protein was observed by immunohistochemistry. The expression levels of SET protein were analyzed by Western Blot. Result. SET protein was expressed predominantly in the theca cells and oocytes of human ovarian follicles in both PCOS ovarian tissues and normal ovarian tissues. The level of SET protein expression in polycystic ovaries was triple higher than that in normal ovaries (P < 0.05). Conclusion. SET was overexpressed in polycystic ovaries more than that in normal ovaries. Combined with its localization in theca cells, SET may participate in regulating ovarian androgen biosynthesis and the pathophysiology of hyperandrogenism in PCOS.