A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
Objective To study the degradable properties of 3D-SC artificial skin in vitro. Methods The 3D-SC artificial skin materials wererespectively immersed into the solutions of 0.9% normal saline (control group), pancreatic tissue liquid (experimental group 1), physiological buffer (Hanks balanced salt solution，experimental group 2) and 0.2 mol/L phosphate buffer (pH 7.4，experimentalgroup 3), and the degradation was carried out at 37℃. The quality lost ratioswere determined on the 3rd day, the 5th day, the 7th day, the 9th day, 11th dayand 14th day in the experimental group 1, while on the 3rd day, 7th day, 14th day, 15th day, 21st day and 30th day in the other groups. Results The 3D-SC artificial skin was degraded completely in pancreatic tissue liquid about within 14 days in the experimental group 1; in the control group, and in the experimental groups 2 and 3, the degradation ratios were 868%±2.30%,28.51%±10.68% and 7.35%±0.61% on the 14th day; 71.83%±2.58%, 91.32%±1.87% and 75.64%±6.13% on the 15th day, being significant difference between the control group and the experimental group 2(Plt;0.01); and 91.87%±8.15%, 95.62%±1.36% and 92.10%±2.26% on the 30th day, being no significant differences between these 3 groups(Pgt;0.05), respectivelies. Conclusion The 3D-SC artificial skin materials have good degradable properties. The trend of degradation speed is from slow to quick and then to slow without enzyme.
Objective To study the development, investigation, and application of the artificial vertebral body so as to provide an essential reference for the future research and clinical application. Methods The recent articles on materials, types, and clinical applications of the artificial vertebral body were reviewed.Results The materials used for the artificial vertebral body were porcelain, alloy, variant bone, and composite. But each of them had its own advantages and disadvantages. The types of the artificial vertebral body were grouped as expandable and non-expandable ones; however, the expandable type was much better. The artificial vertebral body had been applied to the treatments of spinal tumor, tuberculosis, fracture, and infection, with better effects. Conclusion The artificial vertebral body can beextensively applied. However, the materials and types need to be improved.
At present, artificial intelligence (AI) has been widely used in the diagnosis and treatment of various ophthalmological diseases, but there are still many problems. Due to the lack of standardized test sets, gold standards, and recognized evaluation systems for the accuracy of AI products, it is difficult to compare the results of multiple studies. When it comes to the field of image generation, we hardly have an efficient approach to evaluating research results. In clinical practice, ophthalmological AI research is often out of touch with actual clinical needs. The requirements for the quality and quantity of clinical data put more burden on AI research, limiting the transformation of AI studies. The prediction of systemic diseases based on fundus images is making progressive advancement. However, the lack of interpretability of the research lower the acceptance. Ophthalmology AI research also suffer from ethical controversy due to unconstructed regulations and regulatory mechanisms, concerns on patients’ privacy and data security, and the risk of aggravating the unfairness of medical resources.
Objective To investigate the clinical application of self-settingcalcium phosphate cement (CPC) in bone defect repair of extremities. Methods From May 1998 to January 2000, 32 cases of bone defect, in 36 sites, were repairedand reviewed, aged from 4 to 59 years old (24.7 years old on average), with bone defect 2 to 125 cm2 in size (13.1 cm2 on average). The causes of the bone defect werefracture, bone cyst, iliac bone harvesting, fibrous dysplasia, enchondroma and bone tuberculosis, which involved femur, iliac, tibia, humerus, phalanx, fibula, calcaneus, talus and acetabulum. All of the cases were followed up for 1 to 23 months, 15.3 months on average, before radiographic examination. Results All operations were successful and no general response was observed in all of the cases. X-ray examination showed an integrity interface between CPC and bone. And CT showed no gap existed. There was no increase of serum calcium and phosphate levels. Conclusion CPC is applicable in the low- or non-weight-bearing site of the extremities.
Objective
To construct a new composite artificial trachea and to investigate the feasibility of trachea repair and reconstruction with the new composite artificial trachea transplantation in dogs.
Methods
The basic skeleton of the new composite artificial trachea was polytetrafluoroethylene vascular prosthesis linked with titanium rings at both ends. Dualmesh was sutured on titanium rings. Sixteen dogs, weighing (14.9 ± 2.0) kg, female or male, were selected. The 5 cm cervical trachea was resected to prepare the cervical trachea defect model. The trachea repair and reconstruction was performed with the new composite artificial trachea. Then fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction were conducted at immediate, 1 month, and 6 months after operation. Gross observation and histological examination were conducted at 14 months to evaluate the repair and reconstruction efficacy.
Results
No dog died during operation of trachea reconstruction. One dog died of dyspnea at 37, 41, 55, 66, 140, and 274 days respectively because of anastomotic dehiscence and artificial trachea displacement; the other 10 dogs survived until 14 months. The fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction showed that artificial tracheas were all in good location without twisting at immediate after operation; mild stenosis occurred and anastomoses had slight granulation in 6 dogs at 1 month; severe stenosis developed and anastomosis had more granulation in 1 dog and the other dogs were well alive without anastomotic stenosis at 6 months. At 14 months, gross observation revealed that outer surface of the artificial trachea were encapsulated by fibrous connective tissue in all of 10 dogs. Histological examination showed inflammatory infiltration and hyperplasia of fibrous tissue and no epithelium growth on the inner wall of the artificial trachea.
Conclusion
The new composite artificial trachea can be used to repair and reconstruct defect of the trachea for a short-term. Anastomotic infection and dehiscence are major complications and problems affecting long survival.
Objective To explore the advance in physical materials,chemical matrix, and biological seed cells for fabricating artificial nerve. Methods Recent literature relevant to artificial nerve, especially the achievement in physical material, chemical matrix and biological seed cells for fabricating artificial nerve, were extensively reviewed. Results Polymers of polylactic acid or polyglycolic acid and their polymer, polymer of hyaluronic acid and glut-aldehyde, polymer of polyacrylonitrile and polyvinylchloride were artificial nerve materials with the properties of good biocompatibility and biodegradation. A conduit with multichannel and high percentage of pores was beneficial to the regeneration of nerve. The activated Schwann cells were excellent seeds of artificial nerve. A suitable chemical matrix, such as laminin and alginate, could promote the regeneration of nerve. Conclusion The successful fabrication of artificial nerve lies in the advance in the mechanism of nerve regeneration and physical material, chemical matrix and biological seed cells.
ObjectiveTo evaluate the effectiveness of the artificial intelligence-assisted diagnosis and treatment system in distinguishing benign and malignant lung nodules and the infiltration degree.MethodsClinical data of 87 patients with pulmonary nodules admitted to the First Affiliated Hospital of Xiamen University from January 2019 to August 2020 were retrospectively analyzed, including 33 males aged 55.1±10.4 years, and 54 females aged 54.5±14.1 years. A total of 90 nodules were included, which were divided into a malignant tumor group (n=80) and a benign lesion group (n=10), and the malignant tumor group was subdivided into an invasive adenocarcinoma group (n=60) and a non-invasive adenocarcinoma group (n=20). The malignant probability and doubling time of each group were compared and its ability to predict the benign and malignant nodules and the invasion degree was analyzed.ResultsBetween the malignant tumor group and the benign lesion group, the malignant probability was significantly different, and the malignant probability could better distinguish malignant nodules and benign lesions (87.2%±9.1% vs. 28.8%±29.0%, P=0.000). The area under the curve (AUC) was 0.949. The maximum diameter of nodules in the benign lesion group was significantly longer than that in the malignant tumor group (1.270±0.481 cm vs. 0.990±0.361 cm, P=0.026); the doubling time of benign lesions was significantly longer than that of malignant nodules (1 083.600±258.180 d vs. 527.025±173.176 d, P=0.000), and the AUC was 0.975. The maximum diameter of the nodule in the invasive adenocarcinoma group was longer than that of the non-invasive adenocarcinoma group (1.350±0.355 cm vs. 0.863±0.271 cm, P=0.000), and there was no statistical difference in the probability of malignancy between the invasive adenocarcinoma group and the non-invasive adenocarcinoma group (89.7%±5.7% vs. 86.4%±9.9%, P=0.082). The AUC was 0.630. The doubling time of the invasive adenocarcinoma group was significantly shorter than that of the non-invasive adenocarcinoma group (392.200±138.050 d vs. 571.967±160.633 d, P=0.000), and the AUC was 0.829.ConclusionThe malignant probability and doubling time of lung nodules calculated by the artificial intelligence-assisted diagnosis and treatment system can be used in the assessment of the preoperative benign and malignant lung nodules and the infiltration degree.
OBJECTIVE To compare the permeability and incidence rate of complication of arteriovenous internal fistula made by autogenous, homologous, and artificial Teflon blood vessels. METHODS Two hundred and forty one cases with arteriovenous internal fistula made by autogenous, homologous, and artificial Teflon blood vessels were followed up to compare the permeability and incidence rate of complication at 6 months, 1 year, 3 years, and 5 years. RESULTS The incidence rate of complication of autogenous blood vessels was lowest, it had no statistical differences compared with arteriovenous internal fistula made by homologous blood vessels. The permeability of arteriovenous internal fistula made by homologous blood vessels was highest, and it had no statistical differences compared with autogenous blood vessels. The permeability of arteriovenous internal fistula made by artificial Teflon blood vessels was lowest, but the incidence rate of complication was highest, and it had significantly statistical differences compared with arteriovenous internal fistula made by autogenous blood vessels (P lt; 0.01). CONCLUSION Arteriovenous internal fistulas made by autogenous and homologous blood vessels have high permeability and low incidence rate of complication, they are superior to the arteriovenous internal fistula made by artificial Teflon blood vessels.
Objective To review the recent research and clinical progress of artificial osteoconductive materials. Methods Recent and related literatures were extensively and comprehensively reviewed. Results Many achievements about the clinical application of the artificial osteoconductive materials were made. Ithad become one of the hotspots of bone tissue engineering research. Some were clinically applied and good clinical results were achieved. Conclusion As it provides new clinic method for treating bone defect, artificial osteoconductive material is of great potential in its application. To improve its microstructure, macroshape, mechanism of osteoinductive ability, and to accelerate new bone for mation will be the hotspots of the research on artificial osteoconductive material.
