Objective To analyze the basic case data and laboratory test index characteristics of patients with myasthenia gravis(MG),so as to evaluate the application value of common clinical laboratory indicators in the construction of a diagnostic model for MG.Methods A retrospective analysis was performed on the basic data and laboratory indicators of MG patients and gender and age-matched healthy controls diagnosed at Beijing Tiantan Hospital,Capital Medical University from April 2021 to April 2023.A diagnostic model was constructed,and the receiver operating characteristic(ROC)curve was drawn to analyze the area under the curve(AUC).Results The BMI,heart rate,systolic blood pressure,and diastolic blood pressure in the MG group were significantly higher than those in the control group,with statistical significance(P＜0.05).There were significant differences in total protein,albumin,white blood cell count,proportion of large platelets,abso-lute value of monocyte and triiodothyronine between MG group and control group(P＜0.05).Seven indexes of heart rate,diastolic blood pressure,albumin,creatine kinase,cholinesterase,triglyceride and apolipoprotein B were selected to construct the diagnostic model.The area under the curve of the combined application of multiple indexes could reach 0.995,with a sensitivity and specificity of 97.60％and 96.10％,respectively.Conclusion In this study,the laboratory test indexes that can be used for the diagnosis of MG are successfully selected,and the sensitivity and specificity of the combined application of multiple indexes are high,which can be used for the auxiliary diagnosis of MG.

Cerebrospinal fluid morphology examination is an important method of diagnosing central nervous system diseases, but manual microscopy has shortcomings such as low efficiency, long staff training period, and poor homogeneity of test results. In recent years, the application of artificial intelligence in the medical field has developed rapidly, providing new technical means for cerebrospinal fluid morphology examination. In the future, AI-assisted morphological examination of cerebrospinal fluid will not only realize digitalization and networking, but also improve the level and efficiency of intelligent diagnosis of cerebrospinal fluid morphology, which has a broad application prospect in the intelligent assisted diagnosis of cerebrospinal fluid.

Objective:A microsurgical simulation training device based on real clinical scenes was designed and its effectiveness was tested.Methods:From January 1, 2020 to January 1, 2023, postgraduate students in the Plastic and Reconstructive Surgery Department of the First Medical Center of PLA General Hospital and the Plastic Surgery Hospital of Chinese Academy of Medical Sciences were enrolled in this prospective study. The simulation training device consists of four parts: (1)Blood perfusion system, which is used to simulate living animal blood vessels.(2)The inner baffling rod system, which is used to simulate the operation in deep cavity.(3) The exterior baffling rod system, which is used to simulate the operation in difficult positions.(4) A pulsating platform system is used to simulate microsurgery under the influence of respiratory movement. Preliminary verification of the effect of the simulated training device was as follows: Surgeons with no experience in microsurgery were completely randomized assigned to the control group (traditional microsurgery training group) and the experimental group (training group using the simulated training device). After 4 weeks of microsurgical training, the trainees were assigned to perform two surgical skill assessments, the first using a live animal model for end-to-end anastomosis of rat tail arteries, and the second assessment using end-to-end anastomosis of free latissimus dorsi flap arteries in a real case. The performance of the two groups was compared by using operation time and microsurgical GRS score scale including four items of dexterity, visuospatial ability, operative flow and judgment. Chi-squared test was used to analyze gender between the two groups. GRS scores between the two groups were compared by the Mann-Whitney U test. Participants’ ageand operation time between the two groups was compared by independent t-test. P<0.05 was considered statistically significant. Results:A total of 18 trainees were enrolled, including 10 in the control group, 6 males and 4 females, with an average age of (27.80±1.87) years. There were 8 subjects in the experimental group, 4 males and 4 females, with an average age of (28.10±1.56) years old. There were no significant differences in age, gender and other baseline characteristics between the two groups ( P>0.05). There was no significant difference in GRS score and operation time between the control group and the experimental group ( P> 0.05) in the first assessment. However, in the second assessment of real cases, the GRS score of the experimental group was significantly higher than that of the control group(14.25 vs. 5.70), and the operation duration of the experimental group was also shorter than that of the control group, and the difference was statistically significant[(100.37±24.65 ) min vs. (105.60±22.84) min] ( P<0.05). Conclusion:Compared with traditional microsurgery training methods, using microsurgery training devices based on clinical real scenes can effectively shorten the learning curve and enable trainees to master complex micromanipulation skills more quickly.

Objective:A microsurgical simulation training device based on real clinical scenes was designed and its effectiveness was tested.Methods:From January 1, 2020 to January 1, 2023, postgraduate students in the Plastic and Reconstructive Surgery Department of the First Medical Center of PLA General Hospital and the Plastic Surgery Hospital of Chinese Academy of Medical Sciences were enrolled in this prospective study. The simulation training device consists of four parts: (1)Blood perfusion system, which is used to simulate living animal blood vessels.(2)The inner baffling rod system, which is used to simulate the operation in deep cavity.(3) The exterior baffling rod system, which is used to simulate the operation in difficult positions.(4) A pulsating platform system is used to simulate microsurgery under the influence of respiratory movement. Preliminary verification of the effect of the simulated training device was as follows: Surgeons with no experience in microsurgery were completely randomized assigned to the control group (traditional microsurgery training group) and the experimental group (training group using the simulated training device). After 4 weeks of microsurgical training, the trainees were assigned to perform two surgical skill assessments, the first using a live animal model for end-to-end anastomosis of rat tail arteries, and the second assessment using end-to-end anastomosis of free latissimus dorsi flap arteries in a real case. The performance of the two groups was compared by using operation time and microsurgical GRS score scale including four items of dexterity, visuospatial ability, operative flow and judgment. Chi-squared test was used to analyze gender between the two groups. GRS scores between the two groups were compared by the Mann-Whitney U test. Participants’ ageand operation time between the two groups was compared by independent t-test. P<0.05 was considered statistically significant. Results:A total of 18 trainees were enrolled, including 10 in the control group, 6 males and 4 females, with an average age of (27.80±1.87) years. There were 8 subjects in the experimental group, 4 males and 4 females, with an average age of (28.10±1.56) years old. There were no significant differences in age, gender and other baseline characteristics between the two groups ( P>0.05). There was no significant difference in GRS score and operation time between the control group and the experimental group ( P> 0.05) in the first assessment. However, in the second assessment of real cases, the GRS score of the experimental group was significantly higher than that of the control group(14.25 vs. 5.70), and the operation duration of the experimental group was also shorter than that of the control group, and the difference was statistically significant[(100.37±24.65 ) min vs. (105.60±22.84) min] ( P<0.05). Conclusion:Compared with traditional microsurgery training methods, using microsurgery training devices based on clinical real scenes can effectively shorten the learning curve and enable trainees to master complex micromanipulation skills more quickly.

Endothelial progenitor cells (EPCs) play an important role in diabetic vascular complications. A large number of studies have revealed that some clinical antihyperglycemics can improve the complications of diabetes by regulating the function of EPCs. Metformin can improve EPCs function in diabetic patients by regulating oxidative stress level or downstream signaling pathway of adenosine monophosphate activated protein kinase; Pioglitazone can delay the aging of EPCs by regulating telomerase activity; acarbose, sitagliptin and insulin can promote the proliferation, migration and adhesion of EPCs. In addition to lowering blood glucose, the effects of antihyperglycemics on EPCs may also be one of the mechanisms to improve the complications of diabetes. This article reviews the research progress on the regulation of EPC proliferation and function by antihyperglycemics.
Cell Movement/drug effects* ; Cells, Cultured ; Endothelial Progenitor Cells/drug effects* ; Humans ; Hypoglycemic Agents/pharmacology* ; Signal Transduction/drug effects*

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.
Aged ; Betacoronavirus ; isolation & purification ; Cannula ; Coronavirus Infections ; therapy ; Humans ; Oxygen ; administration & dosage ; Pandemics ; Pneumonia, Viral ; therapy

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 infection. Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial flow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.
Aged ; Betacoronavirus ; Cannula ; Coronavirus Infections ; complications ; therapy ; Humans ; Hypoxia ; etiology ; prevention & control ; therapy ; Masks ; Oxygen ; administration & dosage ; Oxygen Inhalation Therapy ; instrumentation ; standards ; Pandemics ; Pneumonia, Viral ; complications ; therapy

Objective:Real-time cell-based assay (RTCA) technology was used to detect the influence of compound Danshen tablets with different concentrations on cells to screen outthe sensitive, stable and concentration-dependent cell lines to provide reference for the quality evaluation experiment of cell biological effects of compound salvia miltiorrhiza tablets. Methods:The effects of compound Danshen tablets on human umbilical vein endothelial cells (Huvec), rat cardiac myocytes (H9C2) and rat thoracic aortic smooth muscle cells (RA-VSMC) were investigated by RTCA. The cell index (CI) was measured to form time-dose dependent cell response curves (TCRPs) to screen the the optimal cell lines by description analysis and statistical analysis. Results:All of the three cells show obvious response to the effects of compound Danshen tablets. The sensitivity of RA-VSMC was relatively poor, the range of effective concentrationof three cells was different, and the concentration gradient dependence was also different. H9c2 cells had good sensitivity to compound Danshen tablets, which was gradient dependent, and the effective concentration range wass 0.3-1.8 mg/ml, and it can be used as a cell for quality evaluation of compound Danshen tablets. Conclusions:RTCA technology can monitor and record the growth status of cells in real time. It can accurately reflect the effects of compound Danshen tablets on different cell lines. The data are objective and reliable. It provides a new experimental technology and method for the quality evaluation of compound Danshen tablets.

Genetic mutations in triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to a variety of neurodegenerative diseases including Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia and Parkinson’s disease. In the brain, TREM2 is highly expressed on the cell surface of microglia, where it can transduce signals to regulate microglial functions such as phagocytosis. To date, mechanisms underlying intracellular trafficking of TREM2 remain elusive. Mutations in the presenilin 1 (PS1) catalytic subunit of the γ-secretase complex have been associated with increased generation of the amyloidogenic Aβ (amyloid-β) 42 peptide through cleavage of the Aβ precursor amyloid precursor protein. Here we found that TREM2 interacts with PS1 in a manner independent of γ-secretase activity. Mutations in TREM2 alter its subcellular localization and affects its interaction with PS1. Upregulation of PS1 reduces, whereas downregulation of PS1 increases, steady-state levels of cell surface TREM2. Furthermore, PS1 overexpression results in attenuated phagocytic uptake of Aβ by microglia, which is reversed by TREM2 overexpression. Our data indicate a novel role for PS1 in regulating TREM2 intracellular trafficking and pathophysiological function.

BACKGROUND:The meniscus injury is one of the most common sports injuries of knee joint. The treatment after injury is always a difficult problem in the clinic. Researchers have been trying to apply the method of using tissue-engineering to solve the problem of meniscus repair after injury.
OBJECTIVE:To summarize tissue-engineered meniscus-related basic research.
METHODS:The first author retrieved China National Knowledge Infrastructure and Medline for literatures on tissue-engineered meniscus. The key words were“meniscus, tissue engineering, basic research”. Articles with unrelated objective and repeated articles were excluded. Final y, 35 articles were included.
RESULTS AND CONCLUSION:There was some controversy about the classification of the cel of the meniscus. The outer tissue of the meniscus is mainly composed of the fibrous cartilage cel s and the extracel ular matrix. The inner tissue of the meniscus is mainly composed of a smal atypical class of cartilage cel s. The biomechanical properties of the meniscus can be properly adjusted when it is subjected to external pressure. The lateral meniscus is assumed to bear al the pressure of the outer part of the knee joint during knee flexion, but the medial meniscus is assumed to bear 50%of the medial part of the knee joint. The etiology and pathophysiology of meniscus injury are not the same, which is highly dependent on the age of onset of the patient. However, in each age group, right knee meniscus injury was the majority. The way of surgical repair of the meniscus tear can be divided into the technology from inside to outside, and that from outside to inside, total internal repair under arthroscopy and open repair technology.