Amyloid β-protein (Aβ) deposition is an important prevention and treatment target for Alzheimer’s disease (AD), and early detection of Aβ deposition in the brain is the key to early diagnosis of AD. Magnetic resonance imaging (MRI) is the perfect imaging technology for the clinical diagnosis of AD, but it cannot display the plaque deposition directly. In this paper, based on two feature selection modes-filter and wrapper, chain-like agent genetic algorithm (CAGA), principal component analysis (PCA), support vector machine (SVM) and random forest (RF), we designed six kinds of feature learning classification algorithms to detect the information (distribution) of Aβ deposition through magnetic resonance image pixels selection. Firstly, we segmented the brain region from brain MR images. Secondly, we extracted the pixels in the segmented brain region as a feature vector (features) according to rows. Thirdly, we conducted feature learning on the extracted features, and obtained the final optimal feature subset by voting mechanism. Finally, using the final optimal selected features, we could find and mark the corresponding pixels on the MR images to show the information about Aβ plaque deposition by elastic mapping. According to the experimental results, the proposed pixel features learning methods in this paper could extract and reflect Aβ plaque deposition, and the best classification accuracy could be as high as 80%, thereby showing the effectiveness of the methods. The proposed methods can precisely detect the information of the Aβ plaque deposition, thereby being helpful for improving classification accuracy of diagnosis of AD.
Research on the deposition of inhalable particles in the alveoli of the lungs is important to the causes, development for common respiratory diseases such as emphysema, and even the optimization of clinical treatment and prevention programs of them. In this paper, an in vitro experimental model was established to simulate the deposition of terminal bronchioles and pulmonary acinus particles. The deposition rate of inhalable particles with different particle sizes in the pulmonary acinus was studied under different functional residual capacity. The results showed that the particle diameter was an important factor affecting the deposition of particles in the lung alveoli. Particles with 1 μm diameter had the highest deposition rate. With the functional residual capacity increasing, particulate deposition rate significantly reduced. The results of this study may provide data support and optimization strategy for target inhalation therapy of respiratory diseases such as emphysema and pneumoconiosis. The established model may also provide a feasible in vitro experimental model for studying the deposition of inhalable particles in the pulmonary alveoli.
Objective To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility. Methods The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats. Results The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded. Conclusion The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.
Objective To investigate the influence of airflow limitation upon lung deposition of inhaled corticosteroids in patients with chronic obstructive pulmonary disease ( COPD) . Methods The radionuclide 99mTc was used to lable budesonide which was inhaled through compressor nebulizer. Lung deposition was evaluated by nuclear medicine pulmonary ventilation scintigraphy. Peripheral to central ratio of lung deposition ( P/C% ) was calculated by region of interest ( ROI) metod. Results Forty-threepatients with stable COPD were enrolled in the study, of whom 41 patients completed the trial. The median age was 68 years ( range, 48 to 79 years) and the median FEV1 was 44. 9% predicted. The P/C% was ( 47. 96 ±6. 08) % . The patients with P/C% more than 50% had a higher FEV1% pred and FEV1 /FVC than those with P/C% less than 50% [ FEV1% pred: ( 51. 85 ±18. 20) % vs. ( 40. 52 ±12. 99) % .FEV1 /FVC: ( 59. 95 ±11. 87) % vs. ( 51. 73 ±9. 28) % ] . There was a positive correlation between P/C% and FEV1% pred ( r = 0. 391, P = 0. 024) and FEV1 /FVC ratio ( r = 0. 517, P = 0. 002) . Conclusion Lung peripheral airway deposition of inhaled corticosteroids was limited by airflow obstruction.
The rutile structure titanium oxide (Ti-O) film was prepared on the pure titanium material TA2 (99.999%) surface by the magnetic filter high vacuum arc deposition sputtering source. The method can not only maintain the material mechanical properties, but also improve the surface properties for better biocompatibility to accommodate the physiological environment. The preparation process of the Ti-O film was as follows. Firstly, argon ions sputtered to the TA2 substrate surface to remove the excess impurities. Secondly, a metal ion source generated Ti ions and oxygen ions by the RF discharge. Meanwhile a certain negative bias was imposed on the sample. There a certain composition of Ti-O film was obtained under a certain pressure of oxygen in the vacuum chamber. Finally, X-ray diffraction was used to research the structure and composition of the film. The results showed that the Ti-O film of the rutile crystal structure was formed under the 0.18 Pa oxygen partial pressure. A Nano scratch experiment was used to test the coating adhesion property, which demonstrated that the film was stable and durable. The contact angle experiment and the platelet clotting experiment proved that the modified surface method had improved platelet adhesion performance, and, therefore, the material possessed better biocompatibility. On the whole, the evaluations proved the modified material had excellent performance.
Research on the deposition of inhaled particles in human pulmonary acinus region is important to the pathogenesis investigation, prevention and treatment of lung diseases. Most of the current research focus on the final deposition fraction of inhaled particles in human acinar region, but little is involved in their dynamic deposition characteristics. In this paper, five multi-alveolar models, G3?G7, were built. The evaluation parameter 1/4 deposition time was introduced to study the particle deposition speed. The deposition characteristics of particles in the diameter ranging 0.1?5 μm were numerically simulated and summarized under the influence of factors such as the generation and structure of model, particle diameter and respiratory mode, shedding some new light on the further research of transport of inhaled particles. The results showed that the generation and structure of model had a significance effect on the deposition of particles. 0.1 μm particles were dominated by Brownian diffusion, which experienced a high deposition fraction, a fast deposition speed and a logarithmic deposition curve, while 5 μm particles were dominated by gravitational sedimentation, with a high deposition fraction, a fast deposition speed and an S-shaped deposition curve. The deposition of 0.3?1 μm particles were influenced greatly by convention and varied with the change of respiratory mode. The research methods and results in this paper can provide theoretical basis and data support for the further exploration of the mechanism, prevention and treatment of lung diseases.
The inhalation and deposition of particles in human pulmonary acinus region can cause lung diseases. Numerical simulation of the deposition of inhaled particles in the pulmonary acinus region has offered an effective gateway to the prevention and clinical treatment of these diseases. Based on some important affecting factors such as pulmonary acinar models, model motion, breathing patterns, particulate characteristics, lung diseases and ages, the present research results of numerical simulation in human pulmonary acinus region were summarized and analyzed, and the future development directions were put forward in this paper, providing new insights into the further research and application of the numerical simulation in the pulmonary acinus region.
Objective To investigate the role of micro RNA-451 (miRNA-451) in promoting the osteogenesis of mesenchymal stem cells (MSCs) by targeting regulatory calcium binding protein 39 (CAB39). Methods pMIR-report and pRL-TK vectors were selected to identify the relationship between miRNA-451 and CAB39 by using dual-luciferase reporter assay. pre-miRNA-451 (group A), anti-miRNA-451 (group C), pre-miRNA negative control (group B), and anti-miRNA negative control (group D) were transfected into the C3H10T1/2 cells, respectively. Then, the cells were collected after osteogenic induction for 7 and 14 days. At 7 and 14 days, the real-time fluorescent quantitative PCR and Western blot assays were performed to detect the related osteogenetic biomarkers [Runx2 and alkaline phosphatase (ALP) mRNA] and expressions of CAB39 protein. At 14 days, the extracellular calcium deposition during the osteogenesis of MSCs was tested by Alizarin red staining method. Results CAB39 was the target gene of miRNA-451. At 7 and 14 days after osteogenic induction, the mRNA expressions of Runx2 and ALP in group A were significantly higher than those in group B (P lt; 0.05), and the expressions in group C was significantly lower than those in group D (P lt; 0.05). Furthermore, at 14 days after osteogenic induction, the protein expression of CAB39 in group A (0.55 ± 0.05) was significantly lower than that in group B (1.00 ± 0.07), and the protein expression in group C (1.21 ± 0.05) was significantly higher than that in group D (1.00 ± 0.04), all showing significant difference (P lt; 0.05). Finally, at 14 days after osteogenic induction, the extracellular calcium deposition in group A was obviously more than that in group B, and group C was downregulated when compared with group D. Conclusion miRNA-451 can promote the osteogenesis process of MSCs by downregulating the CAB39.
Waardenburg syndrome is a rare genetic disease of auditory pigmentation. The main symptom is sensorineural hearing loss. Pigment disorders and other developmental defects in skin, hair, iris, fundus and other parts are specifically divided into four different subtypes, each of which corresponds to different pathogenic genes, which encode transcription factors and signaling molecules that play a key role in the development process of neural crest cells into melanocytes. Because there are multiple subtypes of Waardenburg syndrome, different subtypes exhibit different symptoms, signs and ocular manifestations. Patients with Waardenburg syndrome are often first treated in ENT head and neck surgery due to hearing loss. Lack of theoretical knowledge related to Waardenburg syndrome by ophthalmologists may lead to misdiagnosis or missed diagnosis. Although there are currently limited treatments for the disease, with the continuous development of gene therapy and hearing management methods, the future treatment prospects will be broader.
Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.