A multiscale modelling approach to understand atherosclerosis formation: A patient-specific case study in the aortic bifurcation

Atherogenesis, the formation of plaques in the wall of blood vessels, starts as a result of lipid accumulation (low-density lipoprotein cholesterol) in the vessel wall. Such accumulation is related to the site of endothelial mechanotransduction, the endothelial response to mechanical stimuli and haemodynamics, which determines biochemical processes regulating the vessel wall permeability. This interaction between biomechanical and biochemical phenomena is complex, spanning different biological scales and is patient-specific, requiring tools able to capture such mathematical and biological complexity in a unified framework. Mathematical models offer an elegant and efficient way of doing this, by taking into account multifactorial and multiscale processes and mechanisms, in order to capture the fundamentals of plaque formation in individual patients. In this study, a mathematical model to understand plaque and calcification locations is presented: this model provides a strong interpretability and physical meaning through a multiscale, complex index or metric (the penetration site of low-density lipoprotein cholesterol, expressed as volumetric flux). Computed tomography scans of the aortic bifurcation and iliac arteries are analysed and compared with the results of the multifactorial model. The results indicate that the model shows potential to predict the majority of the plaque locations, also not predicting regions where plaques are absent. The promising results from this case study provide a proof of concept that can be applied to a larger patient population

Association between clinical and cone-beam computed tomography findings in patients with temporomandibular disorders

BACKGROUND AND AIM: The aim of this study was to assess the association between the clinical and cone-beam computed tomography (CBCT) findings in relation to bony changes in patients with temporomandibular disorders (TMD). METHODS: According to the research diagnostic criteria for temporomandibular disorder (RDC/TMD), forty-one patients with type II TMD (42 TM joints) and type III TMD (40 TM joints) were recruited for this study. Condylar position and bony changes including flattening, sclerosis, osteophytes, resorption, and erosion of joint were evaluated by CBCT and compared with clinical findings. Data were analyzed by SPSS software. RESULTS: Condylar flattening, sclerosis, resorption, and erosion were not significantly associated with joint/masticatory muscles pain or crepitus sound. The vertical or horizontal position of the condyle showed no significant relationship with the clinical findings. Condylar osteophyte was significantly associated with pain in masticatory muscles and crepitus (P = 0.030 and P = 0.010, respectively). There was no association between the condylar range of motion and pain in joint or masticatory muscles. CONCLUSION: Condylar osteophyte was significantly associated with both masticatory muscles pain and crepitus sound. No significant relationship was found between the other temporomandibular joint (TMJ) radiographic and clinical findings in patients with TMD. KEYWORDS: Cone-Beam Computed Tomography; Mandibular Condyle; Temporomandibular Joint Disorder

Comparative evaluation of microleakage of composite restorations using fifth and seventh generations of adhesive systems

Introduction: Simultaneous etching of enamel and dentin using the novel generation of adhesive systems with contracted operational steps, has shown a good clinical efficacy. The aim of this study was to evaluate the microleakage of composite restorations using the V and VII generations of adhesive systems on primary teeth. Methods: This study was performed on 45 human intact extracted primary teeth. Following class V cavity preparation, the samples were randomly divided into three groups included 15 teeth based on the type of bonding agent; Single Bond 2, Clearfil S3 Bond or G Bond. After applying the bonding agents, the teeth filled with composite Z250. The microleakage values of incisal and gingival margins were separately scored by 2% basic fuchsine staining based on a 0-3 ordinal ranking system. The data were analyzed by using Kruskal Wallis and Mann_whitney U tests. Results: In overall, the score of microleakage at incisal (0.58±0.94) and gingival (1.06±0.19) edges did not have significant difference. Also, there was no significant difference between incisal and gingival microleakage considering the different types of bonding. Conclusion: Regarding to less operational steps and lower risk of salivary contamination, the VII generation of dentin bonding agents can be applied for filling the class V cavities of primary teeth

A gene-centric approach to biomarker discovery identifies transglutaminase 1 as an epidermal autoantigen

Publisher Copyright: © 2021 National Academy of Sciences. All rights reserved.Autoantigen discovery is a critical challenge for the understanding and diagnosis of autoimmune diseases. While autoantibody markers in current clinical use have been identified through studies focused on individual disorders, we postulated that a reverse approach starting with a putative autoantigen to explore multiple disorders might hold promise. We here targeted the epidermal protein transglutaminase 1 (TGM1) as a member of a protein family prone to autoimmune attack. By screening sera from patients with various acquired skin disorders, we identified seropositive subjects with the blistering mucocutaneous disease paraneoplastic pemphigus. Validation in further subjects confirmed TGM1 autoantibodies as a 55% sensitive and 100% specific marker for paraneoplastic pemphigus. This gene-centric approach leverages the wealth of data available for human genes and may prove generally applicable for biomarker discovery in autoimmune diseases.Peer reviewe

The effect of coarctation degrees on wall shear stress indices

Abstract Coarctation of the aorta (CoA) is a congenital tightening of the proximal descending aorta. Flow quantification can be immensely valuable for an early and accurate diagnosis. However, there is a lack of appropriate diagnostic approaches for a variety of cardiovascular diseases, such as CoA. An accurate understanding of the disease depends on measurements of the global haemodynamics (criteria for heart function) and also the local haemodynamics (detailed data on the dynamics of blood flow). Playing a significant role in clinical processes, wall shear stress (WSS) cannot be measured clinically; thus, computation tools are needed to give an insight into this crucial haemodynamic parameter. In the present study, in order to enable the progress of non-invasive approaches that quantify global and local haemodynamics for different CoA severities, innovative computational blueprint simulations that include fluid–solid interaction models are developed. Since there is no clear approach for managing the CoA regarding its severity, this study proposes the use of WSS indices and pressure gradient to better establish a framework for treatment procedures in CoA patients with different severities. This provides a platform for improving CoA therapy on a patient-specific level, in which physicians can perform treatment methods based on WSS indices on top of using a mere experience. Results show how severe CoA affects the aorta in comparison to the milder cases, which can give the medical community valuable information before and after any intervention

The effect of xerostomia and hyposalivation on the quality of life of patients with type II diabetes mellitus

Background: Diabetes mellitus is a chronic metabolic disease which can have numerous physical effects for patient. Xerostomia is one of these complications. Compared to healthy people, patients with diabetes mellitus, have a worse quality of life, and complications of diabetes are the main determinants of quality of life in these patients. Objective: The aim of this study was to determine the effects of xerostomia and hyposalivation on quality of life of patients with type 2 diabetes mellitus. Methods: This descriptive-analytical epidemiological study was conducted on 200 patients with type 2 diabetes mellitus referred to the diabetes clinic of Shahid Mostafavi in Sari city from October 2015 to January in 2016. A questionnaire containing personal characteristics and medical situation was completed by each person. Then, the Persian Oral Health Impact Profile-14 (OHIP-14-PER) questionnaire was completed by the patients. Eventually, with the use of chewable paraffin for 1.5 min by the patient, stimulated salivary flow rate (SSFR) test was performed, and in order to determine hyposalivation, their saliva amount underwent a gravimetric test. Finally, using statistical software SPSS16, the information was statistically analyzed by independent-samples t-test, Mann-Whitney U, Chi-squared and fisher exact tests. Results: The average age of patient was 56.41 years old (43% male and 57% female). Mean SSFR was 0.7 ml/min in patients and xerostomia were confirmed in 112 patients. Difference between age, gender, drug use, years affecting to diabetes and FBS amount in patient with hyposalivation were not statistically meaningful in proportion to patients without it. But difference between HbA1C and SSFR in patients with hyposalivation were statistically meaningful than to patients without it (p=0.03, p=0.001 respectively). The mean patient score to OHIP-14 were obtained as 38.17. The questionnaire score difference in patients with hyposalivation in proportion to patients without it were not statistically meaningful. Conclusion: Hyposalivation possibility increases in diabetic patients with low metabolic control which can cause more severe side effects in relation to oral health. Xerostomia in diabetic patients has negative effects on oral health related quality of life. Diabetic control and patients’ oral problem improvement is effective in their quality of life promotio

The Relationship between Osseous Changes of the Temporomandibular Joint and RDC/TMD Groups in CBCT Images

Abstract Introduction: Temporomandibular joint disorders (TMD) are the most common disorders of the jaw, and despite their clinical importance, they are not completely understood. This study was aimed to evaluate the changes of temporomandibular joint (TMJ) on cone beam computed tomography (CBCT) images in disc displacement vs. osteoarthritis of the TMJ. Methods: In this study, 45 patients, including 37 women and 8 men (13-89 years of age), were examined. The patients were selected based on RDC/TMD criteria and group I disorders were excluded from the study. Accordingly, group II consisted of 43 joints with jaw clicking or displaced discs, and group III comprised 46 joints with crepitus. CBCT images in sagittal, coronal, and axial sections were examined to assess osseous changes in terms of flattening, sclerosis, erosion, resorption, and osteophyte formation. Data were analyzed using statistical tests including the chi-square, Mann-Whitney, and Kolmogorov-Smirnov tests with the confidence interval of 95%. Results: Mann-Whitney test for the comparison of mean age between groups II and III was not statistically significant (p value=0.06). A significant differences was found between two (RDC/TMD) groups according to the prevalence of condylar erosion, resorption, and osteophyte (

Association between clinical and cone-beam computed tomography findings in patients with temporomandibular disorders

BACKGROUND AND AIM: The aim of this study was to assess the association between the clinical and cone-beam computed tomography (CBCT) findings in relation to bony changes in patients with temporomandibular disorders (TMD). METHODS: According to the research diagnostic criteria for temporomandibular disorder (RDC/TMD), forty-one patients with type II TMD (42 TM joints) and type III TMD (40 TM joints) were recruited for this study. Condylar position and bony changes including flattening, sclerosis, osteophytes, resorption, and erosion of joint were evaluated by CBCT and compared with clinical findings. Data were analyzed by SPSS software. RESULTS: Condylar flattening, sclerosis, resorption, and erosion were not significantly associated with joint/masticatory muscles pain or crepitus sound. The vertical or horizontal position of the condyle showed no significant relationship with the clinical findings. Condylar osteophyte was significantly associated with pain in masticatory muscles and crepitus (P = 0.030 and P = 0.010, respectively). There was no association between the condylar range of motion and pain in joint or masticatory muscles. CONCLUSION: Condylar osteophyte was significantly associated with both masticatory muscles pain and crepitus sound. No significant relationship was found between the other temporomandibular joint (TMJ) radiographic and clinical findings in patients with TMD

A simplified method to account for wall motion in patient-specific blood flow simulations of aortic dissection : comparison with fluid-structure interaction

Aortic dissection (AD) is a complex and highly patient-specific vascular condition difficult to treat. Computational fluid dynamics (CFD) can aid the medical management of this pathology, yet its modelling and simulation are challenging. One aspect usually disregarded when modelling AD is the motion of the vessel wall, which has been shown to significantly impact simulation results. Fluid-structure interaction (FSI) methods are difficult to implement and are subject to assumptions regarding the mechanical properties of the vessel wall, which cannot be retrieved non-invasively. This paper presents a simplified 'moving-boundary method' (MBM) to account for the motion of the vessel wall in type-B AD CFD simulations, which can be tuned with non-invasive clinical images (e.g. 2D cine-MRI). The method is firstly validated against the 1D solution of flow through an elastic straight tube; it is then applied to a type-B AD case study and the results are compared to a state-of-the-art, full FSI simulation. Results show that the proposed method can capture the main effects due to the wall motion on the flow field: the average relative difference between flow and pressure waves obtained with the FSI and MBM simulations was less than 1.8% and 1.3%, respectively and the wall shear stress indices were found to have a similar distribution. Moreover, compared to FSI, MBM has the advantage to be less computationally expensive (requiring half of the time of an FSI simulation) and easier to implement, which are important requirements for clinical translatio

Microleakage of Composite Resin Restorations Using a Type of Fifth and Two Types of Seventh Generations of Adhesive Systems: A Comparative Study

Introduction: In recent dentin adhesive systems etching of enamel/dentin are achieved simultaneously. The objective was to evaluate the microleakage of composite restorations using Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). Methods: Class V cavities were prepared on  45 extracted intact premolars with gingival margins at the cementoenamel junction and they were randomly divided into 3 groups (n=15) based on the type of adhesives: Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). After applying the adhesives, the cavities were filled with Z250 composite resin. The occlusal and gingival microleakage was evaluated using 2% basic fuchsin staining technique. Data were analyzed using Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. Results: The mean rank of occlusal microleakage exhibited significant differences by comparison of G Bond, Clearfil S3 Bond and Single Bond2 (21.07, 30.67) and 17.27, respectively) (P=0.005). There was a significant difference in gingival microleakage of different bonding agents (34.40, 17.83 and 16.77 for G Bond, Clearfil S3 Bond and Single Bond2, respectively) (