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

ObjectiveTo explore the effects and mechanisms of modified Dahuang Huanglian Xiexintang on hepatic oxidative stress injury in type 2 diabetes mellitus （T2DM） rats based on the nuclear factor erythroid 2 related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） axis. MethodSix ZDF （fa/+） rats were as assigned to the blank group， and 30 ZDF （fa/fa） rats were used to induce the T2DM model by feeding a high-fat diet. After successful modeling， the rats were randomly divided into the model group， metformin group （0.18 g·kg^-1）， and low， medium， and high dose groups of modified Dahuang Huanglian Xiexintang （0.54， 1.08， 2.16 g·kg^-1）， with six rats in each group. After 12 weeks of drug intervention， the body mass， liver mass， fasting blood glucose （FBG）， and oral glucose tolerance test （OGTT） levels were measured. Serum total cholesterol （TC）， triglycerides （TG）， high-density lipoprotein cholesterol （HDL）， low-density lipoprotein cholesterol （LDL）， alanine aminotransferase （ALT）， and aspartate aminotransferase （AST） levels were detected using an automatic biochemical analyzer. The pathological changes of liver tissue were observed by hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was used to detect the activity of superoxide dismutase （SOD）， reactive oxygen species （ROS）， glutathione peroxidase （GSH-Px）， and the level of malondialdehyde （MDA） in liver tissues. Immunohistochemistry was used to detect the expression of Nrf2 in the liver. Real time quantitative polymerase chain reaction （Real-time PCR） and Western blot were used to detect the mRNA and protein expression levels of Nrf2 and HO-1 in liver tissues. ResultCompared with the normal group， the model group showed a significant increase in body mass， liver mass， and liver index （P<0.01）. Compared with the model group， the metformin group and the medium and high dose groups of modified Dahuang Huanglian Xiexintang showed a significant decrease in body weight， liver mass， and liver index （P<0.01）. Compared with the normal group， the model group showed significantly increased TC， TG， and LDL levels （P<0.01）， and significantly decreased HDL levels （P<0.01）. Compared with the model group， the metformin group and all doses of modified Dahuang Huanglian Xiexintang showed significantly reduced TC levels （P<0.01）， and significantly reduced TG levels （P<0.05）. The medium and high dose groups of modified Dahuang Huanglian Xiexintang showed significantly reduced LDL levels （P<0.05）. The metformin group and all doses of modified Dahuang Huanglian Xiexintang showed significantly increased HDL levels （P<0.05）. Compared with the normal group， the model group showed significantly increased ALT and AST activities （P<0.01）. Compared with the model group， all doses of modified Dahuang Huanglian Xiexintang and the metformin group showed significantly reduced ALT activities （P<0.05） and significantly reduced AST activities （P<0.01）. Compared with normal group， the model group showed significantly increased FBG at all time points （P<0.01）. Compared with the model group， the metformin group and all doses of modified Dahuang Huanglian Xiexintang showed significantly reduced FBG at 8， 10， 12 weeks. The OGTT results showed that compared with the normal group， the model group had significantly increased blood glucose at all time points （P<0.01）. Compared with the model group， the metformin group showed significantly reduced blood glucose at all time points （P<0.01）， and the medium and high dose groups of modified Dahuang Huanglian Xiexintang showed significantly reduced blood glucose at 90， 120 min （P<0.01）. HE pathology showed clear and regular liver cell structure in the normal group， while the model group showed disordered liver cell structure with visible fat vacuoles and a large number of deformed necrotic cells. The liver tissue structure improved in the metformin group and all doses of modified Dahuang Huanglian Xiexintang， with fewer necrotic cells. Compared with the normal group， the model group showed significantly reduced SOD and GSH-Px levels （P<0.01）， and significantly increased ROS and MDA levels （P<0.01）. Compared with the model group， the metformin group and all doses of modified Dahuang Huanglian Xiexintang showed significantly increased SOD and GSH-Px levels （P<0.01）， and significantly reduced MDA levels （P<0.01）. The medium and high dose groups of modified Dahuang Huanglian Xiexintang showed significantly reduced ROS levels （P<0.05）. Compared with the normal group， the model group showed significantly reduced Nrf2 and HO-1 mRNA expression levels （P<0.01）. Compared with the model group， the metformin group and the medium and high dose groups of modified Dahuang Huanglian Xiexintang showed significantly increased Nrf2 and HO-1 mRNA expression levels （P<0.05）. Immunohistochemistry showed that compared with the normal group， the model group had significantly reduced positive expression of Nrf2 and HO-1 （P<0.05）. Compared with the model group， the metformin group and all doses of modified Dahuang Huanglian Xiexintang showed increased positive expression of Nrf2 and HO-1， with a significant increase in brown-yellow granules around the cell nucleus （P<0.05）. Western blot results showed that compared with the normal group， the model group had significantly reduced protein expression of Nrf2 and HO-1 （P<0.01）. Compared with the model group， the metformin group and all doses of modified Dahuang Huanglian Xiexintang showed significantly increased protein expression of Nrf2 and HO-1 （P<0.01）. ConclusionModified Dahuang Huanglian Xiexintang can significantly improve the general condition and pathological changes of liver tissues in T2DM model rats. This improvement is likely achieved through ameliorating hepatic oxidative stress injury via regulating the Nrf2/HO-1 axis.

ObjectiveTo observe the effect of modified Dahuang Huanglian Xiexintang on mitochondrial autophagy and browning of visceral adipose tissue in obese type 2 diabetes mellitus （T2DM） model ZDF rats. MethodForty ZDF rats were induced with a high-fat diet to establish an obese T2DM model. The rats were randomly divided into five groups： Model group， metformin group （0.18 g·kg^-1）， and high， medium， and low dose groups of modified Dahuang Huanglian Xiexintang （2.16， 1.08， 0.54 g·kg^-1）， with eight rats in each group. Additionally， eight ZDF （fa/+） rats were assigned to the normal group. All groups received an intragastric volume of 10 mL·kg^-1， with the model and normal groups receiving the same volume of purified water once daily for 12 weeks. Fasting blood glucose （FBG） was regularly measured. After 12 weeks of intervention， the body weight， epididymal fat weight， and serum levels of glucose （GLU）， glycated serum protein （GSP）， triglyceride （TG）， total cholesterol （TC）， high-density lipoprotein cholesterol （HDL-C）， and low-density lipoprotein cholesterol （LDL-C） were measured. Hematoxylin-eosin （HE） staining was used to observe pathological changes in epididymal fat tissue. Transmission electron microscopy （TEM） was employed to observe mitochondrial autophagy in adipocytes. Real-time PCR was used to detect the mRNA expression of hypoxia-inducible factor-1α （HIF-1α）， Bcl-2/adenovirus E1B 19 kDa interacting protein 3 （BNIP3）， microtubule-associated protein 1 light chain 3B （LC3B）， p62/SQSTM1， uncoupling protein 1 （UCP1）， iodothyronine deiodinase 2 （Dio2）， and PR domain containing 16 （Prdm16） in epididymal fat. Western blot was used to detect the protein expression of HIF-1α， BNIP3， LC3B， p62， and UCP1 in epididymal fat. ResultCompared with the normal group， the model group showed pathological changes in epididymal fat， with adipocyte mitochondrial condensation and numerous autophagosomes indicating mitochondrial autophagy. The model group also exhibited significantly increased body weight， epididymal fat weight， FBG， GLU， GSP， TC， TG， and LDL-C levels （P<0.01）， significantly decreased HDL-C levels （P<0.01）， significantly elevated mRNA and protein expression of HIF-1α， BNIP3， and LC3B （P<0.01）， significantly reduced mRNA and protein expression of p62 and UCP1 （P<0.01）， and significantly reduced mRNA expression of Dio2 and Prdm16 （P<0.01）. Compared with the model group， all intervention groups showed varying degrees of improvement in epididymal fat pathology. The metformin group and high-dose modified Dahuang Huanglian Xiexintang group displayed intact mitochondrial morphology， clear cristae， uniform matrix， and few autophagosomes and autophagosomes in the adipocyte cytoplasm. The metformin group and high- and medium-dose groups of modified Dahuang Huanglian Xiexintang showed significantly reduced body weight and epididymal fat weight （P<0.01）. The epididymal fat index was reduced in all intervention groups （P<0.05）， and FBG was lowered in all intervention groups （P<0.01）.Serum GSP， GLU， TG， and LDL-C levels were reduced in the metformin group and the high- and medium-dose groups of modified Dahuang Huanglian Xiexintang （P<0.05， P<0.01）. The serum TC level was significantly reduced in the metformin group and high-dose group of modified Dahuang Huanglian Xiexintang （P<0.01）， and HDL-C levels were significantly increased in all intervention groups （P<0.05， P<0.01）. The mRNA and protein expression of HIF-1α， BNIP3， and LC3B were significantly reduced， and UCP1 protein expression was significantly increased in the metformin group and high- and medium-dose groups of modified Dahuang Huanglian Xiexintang （P<0.05， P<0.01）. The mRNA and protein expression of p62， Dio2， and Prdm16 were significantly increased in the metformin group and high-dose group of modified Dahuang Huanglian Xiexintang （P<0.05， P<0.01）. ConclusionModified Dahuang Huanglian Xiexintang may inhibit mitochondrial autophagy and promote the browning of visceral adipose tissue through the HIF-1α/BNIP3/LC3B pathway， thereby improving glucose and lipid metabolism in obese T2DM rats.

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.

Acute respiratory distress syndrome (ARDS) refers to acute diffuse lung injury caused by a variety of intrapulmonary and/or extrapulmonary factors such as infection and trauma. Uncontrolled inflammatory response is the main pathological feature. Different functional states of alveolar macrophages have different effects on inflammatory response. Transcription activating factor 3 (ATF3) is a fast response gene in the early stage of stress. In recent years, it has been found that ATF3 plays an important role in regulating the inflammatory response of ARDS by regulating the function of macrophages. This paper reviews the regulatory effects of ATF3 on alveolar macrophage polarization, autophagy and endoplasmic reticulum stress and its effects on the inflammatory process of ARDS, aiming to provide a new research direction for the prevention and treatment of ARDS.

Objective:To investigate the status of cognition and clinical management of prolonged mechanical ventilation(PMV) among medical staffs in pediatric intensive care unit(PICU) in China, and in order to improve the awareness of PICU medical staffs on PMV and standardize the management of PMV.Methods:The cross-sectional study was conducted with doctors and nurses in PICUs of the collaborative group as the survey objects from July 12 to September 12, 2020.The questionnaire was issued, collected and checked by the Children′s Hospital of Fudan University.Results:(1) PMV related settings: Nine out of eleven hospitals had established PMV multidisciplinary teams, respiratory techniques such as diaphragm ultrasound and airway peak flow monitoring could be respectively executed in 72.7% and 36.4% of PICU.Pulmonary rehabilitation techniques such as airway clearance techniques, induced spirometer exercise, external diaphragm pacemaker stimulation, transfer bed exercise, balloon blowing, hyperbaric oxygen therapy could be respectively executed in 100.0%, 9.1%, 9.1%, 9.1%, 27.3% and 27.3% of PICU, respectively.(2) The cognitive status quo of children′s PMV: The most medical staffs agreed with the view that PMV referred to the children′s continuous mechanical ventilation for more than two weeks.Sixty percent of medical staffs believed that children with PMV had basic central nervous system diseases, and 62.7% of medical staffs believed that the most common causes of difficulty in PMV weaning was abnormal brain function.(3) The cognitive status quo of the children′s PMV management in PICU: Respondents believed that the most commonly used mechanical ventilation mode was synchronized intermittent mandatory ventilation+ pressure support ventilation in children′s PMV during stable disease.Ninety-two percent of medical staffs performed the spontaneous breathing test when weaning.And 58.7% of the respondents agreed to perform tracheotomy for the children during 3 to 4 weeks of mechanical ventilation.More than half of medical staffs would execute diaphragm function assessment, bedside rehabilitation training, nutritional assessment, analgesia and sedation assessment for children with PMV.(4) The cognitive status quo of the children′s PMV management of transition from hospital to family: 54.5% of PICU provided family care training to the family members before the children were discharged from the hospital.One center established the PMV specialized outpatient clinic.45.5% of PICU would follow up these discharged children one month later.Conclusion:At present, PICU medical staffs have different awareness of children′s PMV related problems in China.And children′s PMV lacks a systematic plan regarding diagnosis, treatment and management.

Objective:To evaluate the clinical value of lymph node dissection (LND) for intrahepatic cholangiocarcinoma (ICC) after surgical resection.Methods:A retrospective study was conducted on the clinical data of 156 patients who underwent surgery for ICC in Eastern Hepatobiliary Surgery Hospital of Naval Military Medical University from November 2010 to December 2017, including 94 males and 62 females, aged (60.0±9.5) years. Curative surgery was performed in 114 cases. Of 64 cases were in stage Ⅰ according to American Joint Committee on Cancer (AJCC), including 38 cases of non-lymph node dissection (NLND) and 26 cases of LND; 21 cases were in AJCC stage Ⅱ, including 11 cases of NLND and 10 cases of LND; 22 cases were in AJCC stage Ⅲb, including 14 cases of LND and 8 cases of lymph node resection (LNR); 5 cases were in AJCC stage Ⅲa, 2 cases were in AJCC stage Ⅳ. Univariate and multivariate Cox regression analysis were used for the risk factors of ICC prognosis. The log-rank test compared the survival rates of the two groups.Results:Cox multivariate analysis indicated that lymph node metastasis was independent risk factors for prognosis in patients with ICC ( HR=1.96, 95% CI: 1.09-3.55, P=0.026). A total of 114 patients were included in the curative surgery group. The 1-, 3-, and 5-year overall survival (OS) rates of the negative lymph node group ( n=91) were 65.9%, 47.3% and 35.6%, respectively, which were significantly better than those of the positive lymph node group ( n=23) who had 1-, 3-, 5-year OS rates of 56.5%, 17.7% and 0, respectively (χ 2=8.11, P=0.004 ). In stage Ⅰ and Ⅱ patients, there were no significant differences in 1-, 3-, 5-year OS rates between the NLND group and the LND group (both P>0.05 ). In stage Ⅲb patients, the LND group had 1-, 3-, 5-year OS rates of 71.4%, 29.8% and 0, respectively, significantly better than those of the LNR group who had 1-, 3-, 5-year OS rates of 37.5%, 0 and 0, respectively (χ 2=6.45, P=0.011). Conclusions:Lymph node metastasis is an independent risk factor affecting the prognosis of ICC. Lymph node dissection should be performed cautiously in ICC with AJCC stage Ⅰ and Ⅱ, while routine lymph node dissection is recommended in ICC with AJCC stage Ⅲb.

The massive accumulation of β-amyloid （Aβ） in the brain is believed to be the first pathological mechanism of Alzheimer's disease （AD）， and the accumulation is mainly resulted from the overproduction and dysfunction in the clearance. Extensive and in-depth research has been carried out on AD. In addition to the drugs which are commonly used in clinical settings to improve cognitive function， Aβ monoclonal antibody aducanumab （Aduhelm） has been successfully marketed in the US， which may delay the progress of AD. Thus， it is a potential method for the treatment of AD to target Aβ， but it is expensive， with many adverse reactions and contraindications， which hinders the clinical promotion. Traditional Chinese medicine， featuring multiple components， multiple targets， multiple pathways， and high safety， can regulate the level of Aβ deposition in the brain， alleviate neurotoxicity， and prevent and treat AD by inhibiting the production and aggregation of Aβ and promoting the clearance in the brain. Berberine， gallic acid， osthole， scutellaria barbata flavonoids， Huannao Yicong decoction and Ditantang can promote α-secretase and inhibit the activity and expression of β- and γ-secretase， thus reducing production of Aβ. Baicalein， aloe-emodin， gallic acid， and curcumin can suppress the aggregation of Aβ， promote its depolymerization， and reduce the toxic effect of Aβ on nerve cells by interacting with the hydrophobic structure of Aβ and the H bond， salt bridge， and β-sheet that mediate the aggregation of Aβ. Curcumin and resveratrol can promote the expression of triggering receptor 2 in bone marrow cells of microglia and the migration and phagocytosis of Aβ in microglia. Bilobalide， Kaixinsan and curcumin can up-regulate the expression of encephalin-degrading enzyme and insulin degrading enzyme to promote Aβ degradation， and geniposide， dihydrotanshinone， dihydroartemisinin， and curcumin can degrade Aβ in cells by activating normal autophagy or inhibiting abnormal autophagy. Cycloastragenol， Danggui Shaoyaosan， Yizhi Fangdai formula and Linggui Zhugan decoction can promote the outflow of Aβ and inhibit the inflow of Aβ by improving the integrity and permeability of the blood-brain barrier （BBB）. Yizhi Fangdai formula and Xueshuantong can promote the polarization of aquaporin 4（AQP4）， allow Aβ to be cleared through the lymphatic system， and reduce the aggregation of Aβ in the brain， thereby relieving or preventing nerve cell damage and improving cognitive function. The above summary aims to provide more sufficient evidence and ideas for the clinical treatment of AD with traditional Chinese medicine.

Objective: To analyze the epidemiological characteristics of acute paraquat(PQ)poisoning in children in southwest Shandong, and the risk factors for pulmonary interstitial fibrosis. Methods: This retrospective study was performed on the clinical data of children with acute PQ poisoning admitted from January 2013 to December 2017 in 12 hospitals in southwest Shandong.All participants were divided into pulmonary interstitial fibrosis group and no pulmonary interstitial fibrosis group on the basis of the chest CT 14 days after poisoning.The epidemiological characteristics and risk factors of pulmonary interstitial fibrosis were analyzed. Results: During the study period, a total of 307 children with acute PQ poisoning were admitted to 12 hospitals, of which 61 (19.87%) were suffering from acute PQ poisoning.Forty-nine cases with complete clinical data were analyzed, including 26 male and 23 female patients poisoned by oral.The age distribution ranged from 8 months to 14 years.Poisoning mainly occured from July to September of each year.The mortality of acute PQ poisoning was 8.2%(4/49), and the incidence of pulmonary interstitial fibrosis in survival patients was 44.4%(20/45). Statistical differences (P<0.05) were found between the pulmonary interstitial fibrosis and no pulmonary interstitial fibrosis, with regard to the times of blood purification, the time from poison exposure to blood purification, the application rate of glucocorticoids, the concentration of PQ in urine, the pediatric critical illness score, the time from poison exposure to gastric lavage, the white blood count at admission, serum creatinine, arterial blood lactate, PaO₂, PaCO₂, and PaO₂/FiO₂; however, there was no significant difference in the proportion of blood purification treatment, the mode of blood purification treatment, alanine aminotransferase, aspartate aminotransferase, urea nitrogen, creatine kinase and troponin.Stepwise logistic regression analysis showed that the time from exposure to poison to gastric lavage(OR=0.683, 95%CI 0.210-2.222)and to blood purification(OR=0.0133, 95%CI 0.004-0.042), the times of blood purification(OR=2.862, 95%CI 1.450-5.648), concentration of PQ in urine(OR=1.435, 95%CI 1.085-1.898), and the use of glucocorticoids(OR=0.190, 95%CI 0.048-0.757) were the risk factors for pulmonary interstitial fibrosis(P<0.05). Conclusion Early gastric lavage and blood purification, increasing the frequence of adminitrating purification appropriately, using low-dose glucocorticoids can reduce the incidence of pulmonary interstitial fibrosis of children with acute PQ poisoning.

Porphyromonas gingivalis (P. gingivalis) is the main pathogen of chronic periodontitis (CP). It has been found in recent years that P. gingivalis is associated with the occurrence and development of Alzheimer's disease (AD). P. gingivalis infection may increase the risk of AD, but the pathogenesis remains unclear. In vitro and animal experiments showed that inhibition of gingipains, the main virulence factor of P. gingivalis, could reduce neurodegeneration, decrease the deposition of beta-amyloid protein and control the progression of AD. This article reviews the research progress between P. gingivalis and AD in recent years, and provides references for exploring new prevention and treatment strategies of AD.