Utility of Basal Regional Oximetry as an Early Predictor of Graft Failure After Liver Transplant

Introduction

Adequate perfusion and oxygenation to liver graft after transplantation is essential for its viability. Hepatic oximetry (hepatic tissue oxygenation [LSrO₂]) through near infrared spectroscopy (NIRS) can help by showing real time oxygen content of the graft.

Rapid and sensitive HPLC-MS/MS method for quantitative determination of isochlorogenic acid B in rat plasma and its application in pharmacokinetic study

Asensitive LC-ESI-MS/MS method for determination of isochlorogenic acid B in rat plasma was developed and validated in the present study. Plasma samples were prepared by a simple protein precipitation with methanol containing resveratrol as internal standard (IS). The chromatographic separation was performed on a Zorbax SB-C₁₈ column (3.5 μm, 2.1 mm×100 mm, Agilent, USA) at a flow rate of 0.2 mL/min using methanol/water containing 0.1% formic acid (v/v) as mobile phase. The detectionwas performed on a triple quadrupole tandem mass spectrometer equipped with Electronic Spray Ion by selected reaction monitoring (SRM) of the transitions at m/z 515.3→352.9 for isochlorogenic acid B and m/z 227.1→143.1 for IS, respectively. The calibration curve of the method was linear over the range of 5–2500 ng/mL (r² = 0.9982). The intra- and inter-day precisions (R.S.D.%) were less than 12.46%, and the accuracy (R.E.%) was within ±5.80%. Isochlorogenic acid B was sufficiently stable under all relevant analytical conditions. The validated method was successfully applied to the plasma pharmacokinetic studies of isochlorogenic acid B in rats. It was found that isochlorogenic acid B had non-linear pharmacokinetic characteristics in rats within the dosage ranges from 5 to 20 mg/kg.     

CDC25B and CDC25C overexpression in nonmelanoma skin cancer suppresses cell death

Non‐melanoma skin cancer frequently results from chronic exposure to ultraviolet (UV) irradiation. UV‐induced DNA damage activates cell cycle arrest checkpoints through degradation of the cyclin‐dependent kinase activators, the cell division cycle 25 (CDC25) phosphatases. We previously reported increased CDC25A in nonmelanoma skin cancer, but CDC25B and CDC25C had not been previously examined. Consequently, we hypothesized that increased expression of CDC25B and CDC25C increases tumor cell proliferation and skin tumor growth. We found that CDC25B and CDC25C were increased in mouse and human skin cancers. CDC25B was primarily cytoplasmic in skin and skin tumors and was significantly increased in the squamous cell carcinoma (SCC), while CDC25C was mostly nuclear in the skin, with an increased cytoplasmic signal in the premalignant and malignant tumors. Surprisingly, forced expression of CDC25B or CDC25C in cultured SCC cells did not affect proliferation, but instead suppressed apoptosis, while CDC25C silencing increased apoptosis without impacting proliferation. Targeting CDC25C to the nucleus via mutation of its nuclear export sequence, however, increased proliferation in SCC cells. Overexpression of CDC25C in the nuclear compartment did not hinder the ability of CDC25C to suppress apoptosis, neither did mutation of sites necessary for its interaction with 14‐3‐3 proteins. Analysis of apoptotic signaling pathways revealed that CDC25C increased activating phosphorylation of Akt on Ser⁴⁷³, increased inhibitory phosphorylation of proapoptotic BAD on Ser¹³⁶, and increased the survival protein Survivin. Silencing of CDC25C significantly reduced Survivin levels. Taken together, these data suggest that increased expression of CDC25B or CDC25C are mechanisms by which skin cancers evade apoptotic cell death.     

MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.     

藿朴夏苓汤治疗早期新型冠状病毒肺炎（COVID-19）湿邪郁肺证物质基础及功效的网络分析

目的筛选藿朴夏苓汤治疗早期新型冠状病毒肺炎(COVID-19)湿邪郁肺证的物质基础,预测其作用机制。方法查阅文献及临床报道分析藿朴夏苓汤与早期COVID-19湿邪郁肺证的方证关系。运用TCMSP数据库筛选藿朴夏苓汤中潜在活性成分,将活性成分与新型冠状病毒(SARS-CoV-2)3CL水解酶、血管紧张素转化酶Ⅱ(ACE2)进行分子对接,根据结合能筛选与两者均有较好结合作用的核心成分。借助Cytoscape软件构建关键成分靶点蛋白互作网络,筛选出核心靶点;通过STRING数据库进行核心靶点的GO分析,Cytoscape软件Clue GO插件进行Pathway、KEGG富集分析。结果方证关系分析藿朴夏苓汤用于治疗早期COVID-19湿邪郁肺证,筛选出藿朴夏苓汤中潜在作用成分12个,核心靶点67个。其中通草中的通脱木皂苷元Ⅰ,茯苓、猪苓中的过氧麦角甾醇,半夏中的黄芩苷与SARS-CoV-2 3CL水解酶、ACE2均具有较好的结合活性。GO、Pathway、KEGG富集分析结果显示藿朴夏苓汤中12个潜在作用成分参与调节刺激反应、信号转导、细胞死亡等生物过程以及白介素信号通路、癌症EGFR信号通路、酪氨酸激酶信号转导途径、编程性细胞死亡途径、MAPK信号通路等。结论藿朴夏苓汤以化湿解毒、宣肺透邪治疗早期COVID-19湿邪郁肺证患者,菲酮、黄芩苷、酸枣仁皂苷、啤酒甾醇、常春藤皂苷元、过氧麦角甾醇、柠檬二烯醇、麦角甾-7,22-二烯-3-酮、通脱木皂苷元Ⅰ、泽泻醇B-23-醋酸酯、泽泻醇B、新橙皮苷可能为其主要的物质基础,通过阻断SARS-CoV-2病毒蛋白合成,阻止病毒进入宿主细胞,通过调控白介素信号通路、MAPK信号通路、PI3K-Akt信号通路、T细胞受体信号通路、C型凝集素受体信号通路,抑制相关炎症因子的表达发挥作用。     

基于UPLC-Q/TOF-MS分析淫羊藿炮制前后黄酮组分的变化规律

目的基于UPLC-Q/TOF-MS技术建立淫羊藿炮制前后指纹图谱,对其全成分进行分析并找出标志性化学成分,以明确淫羊藿炮制前后黄酮组分的变化规律。方法采用UPLC-Q/TOF-MS技术,在正离子模式下采集淫羊藿生品及炮制品样品数据,并在此基础上根据正交-偏最小二乘判别分析(OPLS-DA)整体探究9个不同产地、批次的淫羊藿炮制前后化学成分的差异。结果从淫羊藿生品及炮制品中寻找并鉴定出9个标志性化学成分,即8-乙烯-山柰酚、淫羊藿素、淫羊藿次苷I、淫羊藿素-3-O-葡萄糖苷、异戊醇基箭藿苷B、1,3-异戊二烯基朝藿定C、1,3-异戊二烯基-箭藿苷B-7-O-葡萄糖醛酸、3-O-(4-乙酰氧基)鼠李糖-2-O-(间二乙酰氧基)葡萄糖-淫羊藿苷及其同分异构体。结论淫羊藿炮制后黄酮组分结构发生变化,次级糖苷增加,多级糖苷减少,淫羊藿黄酮组分总体向低糖苷组分转化,进一步阐明了淫羊藿加热炮制后黄酮组分的变化规律。     

Innate immune recognition and modulation in hepatitis D virus infection

Hepatitis D virus(HDV) is a global health threat with more than 15 million humans affected. Current treatment options are largely unsatisfactory leaving chronically infected humans at high risk to develop liver cirrhosis and hepatocellular carcinoma. HDV is the only human satellite virus known. It encodes only two proteins, and requires Hepatitis B virus(HBV) envelope protein expression for productive virion release and spread of the infection. How HDV could evolve and why HBV was selected as a helper virus remains unknown. Since the discovery of Na+-taurocholate co-transporting polypeptide as the essential uptake receptor for HBV and HDV, we are beginning to understand the interactions of HDV and the immune system. While HBV is mostly regarded a stealth virus, that escapes innate immune recognition, HBV-HDV coinfection is characterized by a strong innate immune response. Cytoplasmic RNA sensor melanoma differentiation antigen 5 has been reported to recognize HDV RNA replication and activate innate immunity. Innate immunity, however, seems not to impair HDV replication while it inhibits HBV. In this review, we describe what is known up-to-date about the interplay between HBV as a helper and HDV's immune evasion strategy and identify where additional research is required.