ObjectiveTo summarize the clinical application and future application prospects of organoid model in pancreatic cancer. MethodThe domestic and foreign literature related on the application of organoid model in pancreatic cancer was reviewed. ResultsIn recent years, the organoid model of pancreatic cancer was constructed mainly using patient-derived tissues, fine-needle aspiration samples, and human pluripotent stem cells. The biomarkers of pancreatic cancer were screened according to the histological and structural heterogeneities of the primary tumor retained in organoid model, such as microRNA, glypican-1, annexin A6 and protein biomarkers cytokeratin 7 and 20, cell tumor antigen p53, Claudin-4, carbohydrate antigen 19-9, etc.in the extracellular vesicles. The results of organoid model could maintain the original tumor characteristics and the higher correlation between the organoid model drug sensitivity data and the clinical results of pancreatic cancer patients suggested that, the drug sensitivity data of organoid model could be used to avoid ineffective chemotherapy, so as to improve the treatment response rate and reduce the toxicity of chemical drug treatment, and reasonably select individualized treatment plans for pancreatic cancer patients in future. ConclusionsOrganoid model has many research in screening biomarkers of pancreatic cancer, individualized drug screening, and drug sensitivity test. It can simulate the complex pathophysiological characteristics of pancreatic cancer in vitro, and retain the physiological characteristics and gene phenotype of original tumor cells. It is expected to become a new platform for selecting biomarkers of pancreatic cancer, testing drug sensitivity, and formulating individualized treatment methods for pancreatic cancer, which might further accelerate the research progress of pancreatic cancer.
Diabetic macular edema is the major cause of vision impairment in patients with non-proliferative diabetic retinopathy. Thickness and pathological alterations in each retina layer of diabetic macular edema (DME) patients can be performed by optical coherence tomography (OCT) device. And retinal light sensitivity at specific retinal point and fixation state can be detected by microperimetry qualitatively and quantitatively. Moreover, OCT can discover pathological anatomical changes in the retina of DME patients, thus facilitating the interpretation of the structure-function relationship in DME with combination of microperimetry results. At present, there are various therapies for DME patients, and the primary method in evaluating therapeutic efficacy is to compare the pathological changes in the retina before and after treatment by OCT. Besides, microperimetry can provide information in visual function restoration. The combined application of OCT and microperimetry has broad prospects in the diagnosis and treatment of DME patients.
The heart valve prosthesis must have excellent hydrodynamic performance which is usually tested in vitro, not in vivo. This paper comprehensively introduced the principles and methods of hydrodynamic performance in vitro testing, helping clinicians to understand valve performance parameters, evaluate valve applicability, and reduce clinical risk of the valve prosthesis. In vitro testing not only serves as the "gold standard" for valve prosthesis assessment, but also provides detailed data for design and optimization of the prosthesis. ISO 5840 defines the items and methods for valve in vitro testing, which consists of three parts: (1) pulsatile flow testing, which reproduces the pulsating flow of the valve prosthesis after implantation in the human body; (2) steady flow testing, which assesses valve forward flow resistance; (3) durability testing, which evaluates the durability of the valve prosthesis and determines the expected failure mode. In addition, the paper presented the differences between atrioventricular and aortic valve testing, the method of mitral valve testing, the differences between transcatheter and surgical valve testing, and the method of valve flow visualization.
In an anti-thrombotic pressure circulatory device, relays and solenoid valves serve as core execution units. Thus the therapeutic efficacy and patient safety of the device will directly depend on their performance. A new type of testing system for relays and solenoid valves used in the anti-thrombotic device has been developed, which can test action response time and fatigue performance of relay and solenoid valve. PC, data acquisition card and test platform are used in this testing system based on human-computer interaction testing modules. The testing objectives are realized by using the virtual instrument technology, the high-speed data acquisition technology and reasonable software design. The two sets of the system made by relay and solenoid valve are tested. The results proved the universality and reliability of the testing system so that these relays and solenoid valves could be accurately used in the anti-thrombotic pressure circulatory equipment. The newly-developed testing system has a bright future in the aspects of promotion and application prospect.
In vitro experimental test for mechanical properties of a vascular stent is a main method to evaluate its effectiveness and safety, which is of great significance to the clinical applications. In this study, a comparative study of planar, V-groove and radial compression methods for the radial support property test were performed, and the effects of compression rate and circumferential position on the test results were conducted. Based on the three-point bending method, the influences of compression rate and circumferential position on flexibility were also explored. And then a best test proposal was selected to evaluate the radial support property and flexibility of the three self-designed stents and the comparative biodegradable vascular stent (BVS) (BVS1.1, Abbott Vascular, USA) with different outside diameters of 1.4 mm, 1.7 mm and 2.4 mm. The results show that the developing trends of the compression load with the compression displacement measured by the three radial support property test methods are the same, but normalized radial force values are quite different. The planar compression method is more suitable for comparing the radial support properties of stents with different diameters and structures. Compression rate has no obvious effect on the testing results of both the radial support property and flexibility. Compression circumferential position has a great impact on testing radial support property with the planar or V-groove compression methods and testing flexibility with three-point bending method. The radial support properties of all the three self-designed stents are improved at a certain degree compared to that of the BVS stent. The study has better guide significance and reference value for testing mechanical properties of vascular stents.
For the researches relating to the biomedical fields such as preparation of drug micro-particulates and biomedical materials coating, according to the modular design concept and combing the piezoelectric micro-jetting technology with electromechanical engineering and automatic control technology, the drug micro-jetting multifunctional system was designed, which included the spraying support subsystem, X-Y motion platform, Z-axis subsystem and rapid installation subsystem. The drug micro-jetting multifunctional system was run and adjusted. The versatility, rationality and feasibility of this system were validated by the experiments of amoxicillin microcapsule preparation, titanium alloy drug-loaded coating preparation and balloon electrode coating preparation. It was shown that the system can be used as basic platform in multi-disciplinary cross technology research such as biomedical engineering, pharmaceutical engineering and so on.
Neuromuscular disease (NMD) encompasses a group of disorders that affect motor neurons, peripheral nerves, neuromuscular junctions, and skeletal muscles, potentially leading to respiratory muscle impairment and decline in respiratory function, significantly impacting patients' quality of life. In March 2023, clinical practice guideline titled Respiratory Management of Patients with Neuromuscular Weakness was released by the American College of Chest Physicians. This article summarizes, categorizes, and interprets the contents and key points of the guideline, aiming to provide more targeted guidance for clinical healthcare professionals and ultimately enhance the effectiveness of respiratory management for patients with NMD.
The development of muscle strength evaluating system based on Android system was developed in this research. The system consists of a lower unit and an intelligent mobile terminal. The pressure sensor of the lower unit was used to collect muscle strength parameters. And the parameters were sent to the Android device through the wireless Bluetooth serial port. Then the Android device would send the parameters to the doctor monitored platform through the Internet. The system realized analyzing the muscle strength parameters and real-time displaying them. After it ran on the Android mobile phones, it showed an effective result which proved that the system combined with mobile platform could make more convenient for the patients to assess their own muscle strength. It also provided reliable data references for doctors to know the patients' rehabilitation condition and to make the next rehabilitation plan.
Traditional manual testing of ventilator performance is labor-intensive, time-consuming, and prone to errors in data recording, making it difficult to meet the current demands for testing efficiency in the development and manufacturing of ventilators. Therefore, in this study we designed an automated testing system for essential performance parameters of ventilators. The system mainly comprises a ventilator airflow analyzer, an automated switch module for simulated lungs, and a test control platform. Under the control of testing software, this system can perform automated tests of critical performance parameters of ventilators and generate a final test report. To validate the effectiveness of the designed system, tests were conducted on two different brands of ventilators under four different operating conditions, comparing tidal volume, oxygen concentration, and positive end expiratory pressure accuracy using both the automated testing system and traditional manual methods. Bland-Altman statistical analysis indicated good consistency between the accuracy of automated tests and manual tests for all respiratory parameters. In terms of testing efficiency, the automated testing system required approximately one-third of the time needed for manual testing. These results demonstrate that the designed automated testing system provides a novel approach and means for quality inspection and measurement calibration of ventilators, showing broad application prospects.
Objective To compare the biomechanical stability of Kirschner wire and tension band wiring, reconstruction plate combined with tension band wiring, and olecranon anatomical plate in fixing proximal ulna combined with olecranon fracture, so as to provide the theoretical evidence for clinical selection of internal fixation. Methods Eight specimens of elbow joints and ligaments were taken from eight fresh male adult cadaveric elbows (aged 26-43 years, mean 34.8 years) donated voluntarily. The model of proximal ulna combined with olecranon fracture was made by an osteotomy in each specimen. Fracture end was fixed successively by Kirschner wire and tension band wiring (group A), reconstruction plate combined with tension band wiring (group B), and olecranon anatomical plate (group C), respectively. The biomechanical test was performed for monopodium compression experiments, and load-displacement curves were obtained. The stability of the fixation was evaluated according to the load value when the compression displacement of fracture segment was 2 mm. Results No Kirschner wire withdrawal, broken plate and screw, loosening and specimens destruction were observed. The load-displacement curves of 3 groups showed that the displacement increased gradually with increasing load, while the curve slope of groups B and C was significantly higher than that of group A. When the compression displacement was 2 mm, the load values of groups A, B, and C were (218.6 ± 66.9), (560.3 ± 116.1), and (577.2 ± 137.6) N, respectively; the load values of groups B and C were significantly higher than that of group A (P lt; 0.05), but no significant difference was observed between groups B and C (t=0.305, P=0.763). Conclusion The proximal ulna combined with olecranon fracture is unstable. Reconstruction plate combined with tension band wiring and olecranon anatomical plate can meet the requirement of fracture fixation, so they are favorable options for proximal ulna combined with olecranon fracture. Kirschner wire and tension band wiring is not a stable fixation, therefore, it should not be only used for proximal ulna combined with olecranon fracture.