Hepatitis C ; immunology ; Humans ; Killer Cells, Natural ; immunology

Biopsy, Needle ; Genetic Variation ; Hepatitis B, Chronic ; pathology ; Humans ; Liver ; pathology ; Specimen Handling

Objective To explore the mechanism of HIF-1α promoting malignant development of nasopharyngeal carcinoma by upregulating PD-L1 expression under hypoxic conditions. Methods CNE2 cells were divided into normoxia (20%O₂), hypoxia (1%O₂), HIF-1α-siRNA+hypoxia and NC-siRNA+hypoxia groups. Cell proliferation, apoptosis, the mRNA levels of HIF-1α, STAT3 and PD-L1, the protein levels of HIF-1α, PD-L1, STAT3 and STAT3 phosphorylation were detected by MTT assay, flow cytometry, RT-PCR and Western blot, respectively. Results Cell proliferation of hypoxia group was significantly higher than that of normoxia group (P=0.000). The cell proliferation rate of HIF-1α-siRNA+hypoxia group was significantly lower than those in other groups (P=0.000). The apoptosis rate of HIF-1α-siRNA+hypoxia group was remarkably higher than those in other groups (P=0.001). RT-PCR detection showed that the mRNA levels of HIF-1α, PD-L1 and STAT3 in the HIF-1α-siRNA+hypoxia group were significantly lower than those in hypoxia group and NC-siRNA+hypoxia group. The protein expression of HIF-1α, PD-L1 and STAT3 showed similar tendency in Western blot assays compared with the mRNA levels. The pSTAT3 protein expression level in HIF-1α-siRNA+hypoxia group was significantly lower than those in hypoxia group and HIF-1α-siRNA+hypoxia group (P=0.001). Conclusion Under hypoxic microenvironment, HIF-1α may up-regulate the expression of PD-L1 through STAT3, thereby promoting the immune escape of cancer cells, leading to the malignant development of nasopharyngeal carcinoma.

2019-nCoV has spread rapidly around the world, posing a major threat to global public health systems. This is the third time that a highly pathogenic coronavirus has emerged in the human population during the past 20 years. Researchers have conducted a number of studies since the coronavirus epidemic broke out, but there are no specific drugs or vaccines for coronavirus. Therefore, further systematic research on coronavirus is still needed. This review focused on the structure, life cycle and pathogenesis of coronavirus and summarized the current progress in detection approaches, treatment strategies and vaccines for COVID-19 with a view to provide references for further research.

Liver cirrhosis is a liver disease caused by various factors and is characterized by diffuse fibrous hyperplasia, lobular structural damage, and pseudolobule formation. Bile duct proliferation has been observed in a variety of animal models of liver cirrhosis and patients with liver cirrhosis caused by different etiologies, and it is regulated by signaling pathways with the involvement of multiple regulatory factors such as neuropeptides, neurotransmitters, and hormones. Moreover, the proliferated bile ducts promote the formation of liver fibrosis by mediating the proliferation and activation of hepatic stellate cells. This article summarizes the changes of the intrahepatic bile duct system in liver cirrhosis and its influence on the process of liver fibrosis, various signaling pathways associated with cholangiocyte proliferation and liver fibrosis, and the value of the dynamic evolution of bile duct structure in predicting the degree of liver fibrosis. It is pointed out that bile duct proliferation may become a potential target for the intervention of liver fibrosis, which provides new ideas and methods for early treatment and reversal of liver fibrosis.

Hepatic venous pressure gradient (HVPG) is the "gold standard" for diagnosing portal hypertension and determining its severity, but its wide clinical application is limited due to its invasiveness and difficulties in operation. The replacement of HVPG by noninvasive methods has become a research hotspot in recent years; however, the accuracy of the existing serological and imaging methods remains to be discussed, and such methods cannot completely replace HVPG in clinical practice. Liver biopsy has been widely used in clinical practice for many years and is still an indispensable method for the diagnosis of some liver diseases. Recent studies have found that several pathological indicators after liver biopsy, such as collagen area, fibrous septal thickness, nodule size, microvascular density, and density and area of bile ducts and lymphatic vessels, can not only judge the severity of liver fibrosis, but also have a good correlation with portal venous pressure, which provides new ideas for diagnosing cirrhotic portal hypertension and evaluating the severity of portal hypertension.