DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis.

BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options. METHODS: A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy. RESULTS: A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk. CONCLUSIONS: Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

Thermal response of a dental tissue induced by femtosecond laser pulses.

This paper reports a theoretical and experimental study for thermal transport in a thin slice of human tooth induced by a 120 fs, 800 nm pulse laser at a repetition rate of 1 kHz. The surface reflectivity of enamel and the convection heat transfer coefficient were determined using an inverse heat transfer analysis. Instead of a fully three-dimensional modeling, two simplified two-dimensional (2D) planar and axisymmetric heat conduction models were proposed to simulate the temperature fields. The temperature responses obtained from the 2D planar and axisymmetric model agree well with the experimental measurements. On the other hand, the one-dimensional (1D) result significantly differs from the 2D axisymmetric one, suggesting that care should be taken when a 1D thermal model is considered for estimating temperature response.

[Risk analysis and preventive strategies of implant placement in patients with hypertension].

Recently, among the edentulous patients who undergo dental implants, the proportion of hypertensive patients remains high, which poses a greater challenge for clinicians to operate and to maintain the therapeutic effect. The present review comprehensively summarized clinical researches about the adverse effects on dental implants, outlined molecular mechanisms of the positive effects of various antihypertensive drugs on bone metabolism, and proposed that clinicians should select preventive strategies during preoperative and intraoperative procedures according to the blood pressure of patients with hypertension.

Crystal and molecular structure of a thymine phototrimer.

Thymine trimer was isolated from a frozen aqueous solution of thymine which was irradiated with ultraviolet light and was presumably formed through the rearrangement of an initial oxetane photoproduct. X-ray diffraction analysis of a single crystal has confirmed the trimeric diol structure and has established the stereoconfiguration of the molecule. The possible importance of the diol structure in photobiology is pointed out.

Maxillary sinus floor elevation using a tissue-engineered bone complex with beta-TCP and BMP-2 gene-modified bMSCs in rabbits.

OBJECTIVES: To study the effects of maxillary sinus floor elevation by a tissue-engineered bone complex with beta tricalcium phosphate (beta-TCP) and bone morphogenetic protein-2 (BMP-2) gene-modified bone marrow stromal cells (bMSCs) in rabbits. MATERIAL AND METHODS: bMSCs derived from New Zealand rabbit bone marrow were cultured and transduced with the adenovirus with BMP-2 (AdBMP-2), adenovirus with enhanced green fluorescent protein gene (AdEGFP) in vitro. Gene transfer efficiency was detected by EGFP expression. These gene-modified autologous bMSCs were then combined with a beta-TCP granule scaffold at a concentration of 2 x 10(7) cells/ml and used to elevate the maxillary sinus floor in rabbits. Twenty rabbits were randomly allocated into groups and sacrificed at weeks 2 and 8. For each time point, 20 maxillary sinus floor elevation surgeries were made bilaterally in 10 rabbits for the following groups (n=5 per group): group A (beta-TCP alone), group B (untransduced bMSCs/beta-TCP), group C (AdEGFP-bMSCs/beta-TCP), and group D (AdBMP-2-bMSCs/beta-TCP). All samples were evaluated by histology and histomorphometric analysis. The fate of implanted bMSCs was traced initially by a confocol fluorescent microscope in the AdEGFP group. RESULTS: Gene transfer efficiency reached up to 60-80% with 50 PFU/cell transduction as demonstrated by fluorescent microscopic analysis in the AdEGFP group. The augmented maxillary sinus height was maintained for the four groups till 8 weeks post-surgery, while new bone area increased over the time. At week 2, bone areas in groups B-D were significantly larger than those in group A, while at week 8, in group D, the BMP-2 gene-enhanced tissue-engineered bone had the largest bone area among the groups (P<0.05, ANOVA). In that group, a mature bone structure was detected in the center of the elevated space. Under a confocal microscope, green fluorescence in newly formed bone was observed for the EGFP group, which suggested that those implanted bMSCs might have contributed to the new bone formation. CONCLUSION: bMSCs modified with the AdBMP-2 gene can promote new bone formation and maturation in the rabbit maxillary sinus. BMP-2 regional gene therapy and a tissue engineering technique could be effectively used in maxillary sinus elevation and bone regeneration.

Change in symptom clusters in head and neck cancer patients undergoing postoperative radiotherapy: A longitudinal study.

PURPOSE: Research on symptom clusters is a newly emerging field in oncology; however, little evidence regarding symptom clusters in head and neck cancer (HNC) is currently available. To clarify this under-researched area, we investigated symptom clusters among patients with HNC treated with surgery and postoperative radiotherapy. We also examined the pattern of symptom clusters throughout the treatment course. METHOD: A convenience sample of 100 patients with HNC was recruited in the Ear, Nose, and Throat unit of a medical center in Taiwan. Before undergoing postoperative radiotherapy, patients were asked to complete the MD Anderson Symptom Inventory and a demographic sheet. Patients completed the same inventory questionnaire at week 1, 2, 3, 4, 5, and 6 of radiotherapy. RESULT: Two symptom clusters were observed, and they were stable throughout the course of radiotherapy. Cluster 1, the HNC-specific cluster, comprised the symptoms of pain, dry mouth, lack of appetite, sleep disturbance, fatigue, drowsiness, distress, and sadness. Cluster 2, the gastrointestinal cluster, included nausea, vomiting, numbness, shortness of breath, and difficulty remembering. CONCLUSION: This study advanced our knowledge of symptom clusters in patients with HNC. The results are expected to contribute to the development of appropriate assessment and nursing interventions targeting multiple symptoms that may coexist in postoperative radiotherapy.

Aortic valve stenosis causing a left-to-right shunt in persistent left superior vena cava communicating with the left atrium.

This study demonstrated a rare anomaly of a persistent left superior vena cava draining into the left atrium in a patient with developing left-to-right shunt caused by bicuspid aortic stenosis. The venous system, including the coronary sinus, was otherwise normal. We believe that, in this anatomic situation, a marked increase in left ventricular impedance caused a moderate left-to-right shunt from the left atrium into the left innominate vein. At operation, the aortic valve was replaced with a mechanical prosthesis and the anomalous vein was ligated. The convalescence was uneventful.

[Dental anxiety among college students].

In an epidemiological survey comprising 920 college students in 1988, dental anxiety was measured among 525 students, using Corah's questionnaire (CDAS). The data were analyzed with the view to evaluate the level of dental anxiety and analyse the cause. The results indicated that the level of dental anxiety in Chinese college students was significantly higher than that in foreign college students, women student's average score is significantly higher than men's (P less than 0.001). The immediate antecedent of painful dental experience, the influence of dental environment, the indirect experiences gained from the attitude of family or peer group, and the lack of knowledge of oral health were multifactorial risk factors of dental anxiety.

Preparation and properties of antibacterial polyvinyl chloride.

BACKGROUND: Plastic products improve people's daily life, but microorganisms attaching to plastic product surfaces present health hazards. AIM: Our study aimed to design a new kind of antibacterial plastic products to promote a higher quality of life. MATERIALS AND METHODS: Antibacterial polyvinyl chloride (PVC) composites were prepared using melt-blending. The antibacterial properties, mechanical properties, and optical transparencies of the PVC composites containing either silver-doped glass or silver-doped zirconium phosphate were studied, and the dispersal of these antibacterial agents throughout the PVC was also observed using scanning electron microscopy. RESULTS: The results showed that the antibacterial agents were well-dispersed throughout the PVC matrix and that the antibacterial ratio of PVC-G against Escherichia coli and Staphylococcus aureus was over 99.0%, which was better than that of PVC-P. The antibacterial agents had little effect on the mechanical properties of the PVC; however, they decreased the optical transparency of PVC, and the transmittance of PVC-P was decreased by 28.3%. CONCLUSIONS: Our results indicate that such kinds of antibacterial PVC composites have great potential in a wide variety of safer plastic applications.

Preparation and characterization of whey protein film incorporated with TiO2 nanoparticles.

Biodegradable titanium dioxide (TiO(2))/whey protein isolate (WPI) blend films were made by casting denatured WPI film solutions incorporated with TiO(2) nanoparticles. X-ray diffraction, UV-vis spectra, and fluorescence spectra of the films showed the successful incorporation of TiO(2) nanoparticles into the WPI matrix and indicated the interactions between TiO(2) and WPI. Mechanical tests revealed the antiplasticizing effect of TiO(2) nanoparticles on the WPI/TiO(2) film. Small amounts (<1 wt%) of added TiO(2) nanoparticles significantly increase the tensile properties of WPI film, but also decrease the moisture barrier properties. The addition of higher amounts (>1 wt%) of TiO(2) improves moisture barrier properties but lowers the tensile properties of the film. Microstructural evaluation confirmed the aggregation and distribution of TiO(2) nanoparticles within the WPI matrix and validated the results of functional properties of the WPI/TiO(2) film.

[Study of three-dimensional changes in the permanent bases of complete dentures after secondary heat treatment].

Points on tissue surfaces of 15 pairs of complete denture have been measured before and after second time processing by using three coordinate measuring machine (contactable style). 49 points on the upper dentures and 55 points on the lowers are selected to be measured. The findings are as follows: (1) Existence of the trend of shape distortion. The difference of the changes between dentures are quite large. In the upper dentures, the palatal areas bend upward while the bilateral flanges rotate inward and downward. In the lower dentures, the lingual parts distort downward and the buccal parts distort upward. (2) The distributing pattern of the dimensional changes. In the upper dentures the changes are obviously in front, central palatal areas and the flanges. In the lower dentures, the rear parts change most. Therefore this dimensional changes are in three different axes. The result shows that it is hardly to compare with that of the studies on discrepancy.

Adrenergic regulation of coronary microcirculation after extracorporeal circulation and crystalloid cardioplegia.

The purpose of the present study was to examine whether adrenoceptor-mediated responses of porcine coronary resistance arteries are affected by cardioplegic arrest under conditions of extracorporeal circulation (cardiopulmonary bypass; CPB). Pigs were placed on CPB. The hearts were arrested with a cold hyperkalemic crystalloid cardioplegic solution for 1 h, then were reperfused for 1 h. In vivo and in vitro beta-adrenoceptor-mediated responses were compared before CPB and 2 min and 1 h after initiation of reperfusion. In vitro responses were studied in a pressurized no-flow state with video microscopy. Isoproterenol (0.02 micrograms.kg-1.min-1, intracoronary) increased coronary blood flow by 100 +/- 32% (P < 0.001) before CPB and cardioplegic arrest, 17 +/- 7% 2 min postcardioplegia (P < 0.01), and 71 +/- 9 (P < 0.001) after 1 h of reperfusion. Relaxation of precontracted microvessels (90-180 micron) to isoproterenol, NaF, forskolin, and adenosine was reduced after cardioplegic arrest (all P < 0.001). After 1 h of postcardiolegia-reperfusion, relaxation responses to forskolin and adenosine were completely restored, whereas the responses to isoproterenol (P < 0.05) and NaF (P < 0.10) were only partially recovered. Cardioplegic arrest and postcardioplegia-reperfusion blunted the alpha 2-adrenoceptor-mediated endothelium-dependent relaxation to clonidine (P < 0.001) but did not affect the minimal (< 4%) contractile response to the alpha 1-adrenoceptor agonist phenylephrine or the relaxation to nitroprusside. These results show that hyperkalemic cardioplegia results in the generalized defect in the beta-adrenoceptor-GS protein-adenylate cyclase pathway, which is significantly restored after reperfusion.