Coronavirus disease 2019 (COVID-19) is a multi-system disease that can lead to various severe complications. Acute limb ischemia (ALI) has been increasingly recognized as a COVID-19-associated complication that often predicts a poor prognosis. However, the pathophysiology and molecular mechanisms underlying COVID-19-associated ALI remain poorly understood. Hypercoagulability and thrombosis are considered important mechanisms, but we also emphasize the roles of vasospasm, hypoxia, and acidosis in the pathogenesis of the disease. The angiotensin-converting enzyme 2 (ACE2) pathway, inflammation, and platelet activation may be important molecular mechanisms underlying these pathological changes induced by COVID-19. Furthermore, we discuss the hypotheses of risk factors for COVID-19-associated ALI from genetic, age, and gender perspectives based on our analysis of molecular mechanisms. Additionally, we summarize therapeutic approaches such as use of the interleukin-6 (IL-6) blocker tocilizumab, calcium channel blockers, and angiotensin-converting enzyme inhibitors, providing insights for the future treatment of coronavirus-associated limb ischemic diseases.
Humans ; COVID-19/physiopathology* ; Ischemia/etiology* ; SARS-CoV-2 ; Extremities/blood supply* ; Risk Factors ; Interleukin-6/antagonists & inhibitors* ; Acute Disease ; Angiotensin-Converting Enzyme 2

Theory and technology of Medical Immunology are widely used in scientific research.Our teaching and research group uses experimental teaching of Medical Immunology as a platform to carry out practice of scientific research project-based experi-mental system among"5+3"integration students.By completing a mini-project research including experimental design-experimental operation-research article writing,students cultivated scientific research thinking and exercised scientific research practice ability,and generally reported that the course is very difficult,but after completing it,it is very rewarding.

With the rapid development of artificial intelligence(AI),how to digitize the teaching of Medical Immunology is a new challenge posed by the times and education.This study is based on the advanced teaching model of Medical Immunology,which includes lectures-PAD class-flipped classrooms-expert lecture.By introducing knowledge mapping and AI teaching assistant into the entire learning process,the students not only deepen their understanding of the knowledge system of Medical Immunology,but also ex-ercise their ability to apply immunological knowledge to solve practical clinical problems,enhance their self-learning ability,expres-sion ability,communication ability,on-site performance ability,and cultivate a spirit of unity,cooperation,and exploration.The practice of empowering Medical Immunology teaching with digital intelligence achieves the integration of theory and application,the linkage between in class and out of class teaching,the connection between commonalities and individualities,and the union of abili-ties and qualities in Medical Immunology teaching.It also provides practical basis for exploring the implementation path of digital intel-ligence empowerment in Medical Immunology teaching.

Objective To investigate the expression level of centromere protein(CENP)Ⅰin lung adenocarcinoma cells,to study the effects of CENPⅠon the proliferation,invasion,migration,apoptosis,and epithelial-mesenchymal transition(EMT)of lung adenocarci-noma cells,and to explore the possible mechanisms related to its occurrence.Methods The expression of CENPⅠmRNA and protein in four types of lung adenocarcinoma cells and normal alveolar epithelial cells were detected by quantitative real-time polymerase chain reaction(RT-qPCR)and Western blotting.The expression of CENPⅠin H1650 cells was knocked down by the siRNA technique,The transfection efficiency was detected by RT-qPCR and Western blotting.The effects of knock-down CENPⅠon proliferation,cell cycle,apoptosis,invasion and migration of H1650 cells were detected by the cell counting kit-8 assay,the transwell assay,and flow cytometry.Western blotting was used to detect the expression of E-cadherin,N-cadherin,vimentin,Ki-67,cyclin D1,Bcl-2,PI3K,AKT,mTOR,p-PI3K,p-AKT,and p-mTOR.Results After the knock-down of CENPⅠ,the proliferative ability of the H1650 cells significantly decreased,the number of apoptotic cells significantly decreased,and the cell invasion and migration abilities significantly decreased(P<0.01).E-cadherin expression was upregulated and N-cadherin,vimentin,Ki-67,cyclin D1,Bcl-2,p-PI3K,p-AKT,and p-mTOR expres-sion were down-regulated in the CENTI group compared with the control group(P<0.05).The expression of p-PI3K,p-AKT,and p-mTOR in the si-CENPⅠ+IGF-1 group was upregulated compared to that in the si-CENPⅠgroup(P<0.05).Conclusion High expression of CENPⅠin lung adenocarcinoma cells promotes the proliferation,invasion,and migration of lung adenocarcinoma H1650 cells and EMT inhibits apoptosis,which may be related to the activation of the PI3K/AKT/mTOR signaling pathway.

Objective To investigate the expression level of centromere protein(CENP)Ⅰin lung adenocarcinoma cells,to study the effects of CENPⅠon the proliferation,invasion,migration,apoptosis,and epithelial-mesenchymal transition(EMT)of lung adenocarci-noma cells,and to explore the possible mechanisms related to its occurrence.Methods The expression of CENPⅠmRNA and protein in four types of lung adenocarcinoma cells and normal alveolar epithelial cells were detected by quantitative real-time polymerase chain reaction(RT-qPCR)and Western blotting.The expression of CENPⅠin H1650 cells was knocked down by the siRNA technique,The transfection efficiency was detected by RT-qPCR and Western blotting.The effects of knock-down CENPⅠon proliferation,cell cycle,apoptosis,invasion and migration of H1650 cells were detected by the cell counting kit-8 assay,the transwell assay,and flow cytometry.Western blotting was used to detect the expression of E-cadherin,N-cadherin,vimentin,Ki-67,cyclin D1,Bcl-2,PI3K,AKT,mTOR,p-PI3K,p-AKT,and p-mTOR.Results After the knock-down of CENPⅠ,the proliferative ability of the H1650 cells significantly decreased,the number of apoptotic cells significantly decreased,and the cell invasion and migration abilities significantly decreased(P<0.01).E-cadherin expression was upregulated and N-cadherin,vimentin,Ki-67,cyclin D1,Bcl-2,p-PI3K,p-AKT,and p-mTOR expres-sion were down-regulated in the CENTI group compared with the control group(P<0.05).The expression of p-PI3K,p-AKT,and p-mTOR in the si-CENPⅠ+IGF-1 group was upregulated compared to that in the si-CENPⅠgroup(P<0.05).Conclusion High expression of CENPⅠin lung adenocarcinoma cells promotes the proliferation,invasion,and migration of lung adenocarcinoma H1650 cells and EMT inhibits apoptosis,which may be related to the activation of the PI3K/AKT/mTOR signaling pathway.

With the rapid development of artificial intelligence(AI),how to digitize the teaching of Medical Immunology is a new challenge posed by the times and education.This study is based on the advanced teaching model of Medical Immunology,which includes lectures-PAD class-flipped classrooms-expert lecture.By introducing knowledge mapping and AI teaching assistant into the entire learning process,the students not only deepen their understanding of the knowledge system of Medical Immunology,but also ex-ercise their ability to apply immunological knowledge to solve practical clinical problems,enhance their self-learning ability,expres-sion ability,communication ability,on-site performance ability,and cultivate a spirit of unity,cooperation,and exploration.The practice of empowering Medical Immunology teaching with digital intelligence achieves the integration of theory and application,the linkage between in class and out of class teaching,the connection between commonalities and individualities,and the union of abili-ties and qualities in Medical Immunology teaching.It also provides practical basis for exploring the implementation path of digital intel-ligence empowerment in Medical Immunology teaching.

Theory and technology of Medical Immunology are widely used in scientific research.Our teaching and research group uses experimental teaching of Medical Immunology as a platform to carry out practice of scientific research project-based experi-mental system among"5+3"integration students.By completing a mini-project research including experimental design-experimental operation-research article writing,students cultivated scientific research thinking and exercised scientific research practice ability,and generally reported that the course is very difficult,but after completing it,it is very rewarding.

Acral melanoma(AM)is the most common histologic subtype of melanoma in dark-skinned patients and is associated with a worse prognosis and a high mortality rate,largely due to the inconspicuous nature of early-stage lesions,which can lead to late diagnosis.Because of the overlapping clinical and histopathological features of AM with other forms of cutaneous melanomas,early detection of AM requires a multidisciplinary approach that integrates various diagnostic modalities,including clinical examination,dermoscopy,histopathology,molecular testing,radiological imaging,and blood tests.While surgery is the preferred method of treatment for AM,other therapeutic options may be employed based on the stage and underlying etiology of the disease.Immune checkpoint inhibitors,molecular targeted therapy,radiotherapy,chemotherapy,and oncolytic virotherapy represent promising advanced treatment options for AM.In this review,we provide an overview of the latest advancements in diagnostic and therapeutic methods for AM,highlighting the importance of early detection and the prompt,individualized management of this challenging disease.

Objective:To investigate the changes and clinical significance of vascular endothelial growth factor (VEGF) and vascular cell adhesion molecule-1 (VCAM-1) levels in patients undergoing breast cancer resection before and after radiotherapy.Methods:A total of 110 patients who were treated in our hospital from Jun. 2022 to Jun. 2023 for breast cancer and were to receive radiotherapy after surgery were prospectively selected as the observation group. Another 110 healthy volunteers were selected as the control group. The levels of VEGF and VCAM-1 in peripheral blood were compared, and the relationship among general data, tumor pathology and peripheral blood VEGF and VCAM-1 in the observation group was analyzed, and their relationship with disease and prognosis was analyzed.Results:VEGF and VCAM-1 levels in peripheral blood in the observation group were significantly higher ( F=1288.37, 309.32, P<0.05). The levels of VEGF and VCAM-1 in peripheral blood in the observation group were significantly lower than before radiotherapy ( t=23.45, 11.88, P<0.05). Before and after radiotherapy, VEGF and VCAM-1 levels in peripheral blood in the observation group were correlated with tumor stage, tumor differentiation degree and Ki-67 proliferation index ( ttumor stage=7.05, 2.14, 4.52, 4.76, ttumor differentiation degree=7.12, 6.62, 2.81, 3.15, tKi67 proliferation index=7.25, 4.60, 4.24, 2.48, P<0.05) ; Of 110 patients in the observation group, 73 were effective and 34 were ineffective. VEGF and VCAM-1 in effective group were significantly lower ( t=7.27, 9.08, P<0.05). Spearman correlation coefficient analysis showed that VEGF and VCAM-1 levels were significantly positively correlated with tumor stage and Ki67 proliferation index before and after radiotherapy ( rbefore radiotherapy=0.64, 0.54, 0.52, 0.52, rafter radiotherapy=0.32, 0.39, 0.37, 0.24, P<0.05), and negatively correlated with tumor differentiation degree ( rbefore radiotherapy=-0.41, -0.31, rafter radiotherapy=-0.68, -0.41, P<0.05). The prognostic value of combined radiotherapy was 0.801 [95% CI (0.714-0.871) ], which was higher than that of VEGF and VCAM-1 alone 0.690 [95% CI (0.5955-0.775) ] and 0.734 [95% CI (0.641-0.814) ]. Conclusion:The changes of VEGF and VCAM-1 levels in peripheral blood have a certain value in evaluating the short-term prognosis of patients undergoing breast cancer resection by radiotherapy.

Objective To explore the age-related biological properties of bone-derived mesenchymal stem cells(BMSCs)from mice of different age groups and their osteogenic differentiation induced by bone morphogenetic protein 2(BMP2).Methods Eight C57BL/6J mice were divided into a young group(4 weeks old,weighing 10～15 g,n=4)and an old group(12 months old,weighing 20～25 g,n=4),with half male and half female.MSCs were extracted from the whole bones of the 2 groups of mice.After the obtained cells were identified with flow cytometry for the surface markers,β-galactosidase staining was employed to compare the senescence level of BMSCs,MTT and EdU incorporation assays were conducted to compare the proliferation and self-renewal abilities of between the 2 groups.Western blotting was employed to analyze the expression of CyclinD1 and P21 in BMSCs.Then ALP staining,Alizarin Red staining and RT-qPCR were used to evaluate the osteogenic differentiation ability of the cells.RNA sequencing was performed to compare the differential gene expression in BMP2-induced BMSCs.Lastly,the sequencing results were re-confirmed by using flow cytometry.Results Flow cytometry showed that the sorted and cultured mouse BMSCs met the criteria for MSCs.The results of β-galactosidase staining indicated that the senescence level of BMSCs in the old group was significantly higher than that in the young group(P＜0.05).MTT and EdU doping experiments revealed that the cell viability and proliferation ability of BMSCs were significantly lower in the old group than the young group(P＜0.05).Western blotting displayed that the expression level of cell cycle protein CyclinD1 was lower,whereas that of cell cycle inhibitory factor P21 was significantly higher in the BMSCs from the old group than the cells from the young group(P＜0.05).ALP/Alizarin Red staining and RT-qPCR demonstrated that the BMSCs from the young group had stronger osteogenic differentiation capacity after BMP2 treatment when compared the cells of the old group(P＜0.05).RNA sequencing results displayed that the changing profile of CD51 expression was in opposite trends in the young and old BMSCs after BMP2 treatment.Finally,flow cytometry revealed that the percentage of CD51+cells within the CD45-cells was significantly higher in the young group than the old group.Conclusion The decrease in the percentage of CD51+cells among CD45-cells in aged BMSCs is closely associated with their decreased responsiveness to BMP2-induced osteogenic differentiation.