Patch-clamp is used to study all sorts of ionic channels and their regulations with measuring pA current of cell ionic channel, but the fast capacitance (C-fast) compensation and slow capacitance (C-slow) compensation transient currents are caused by measuring objects and measuring instruments themselves which will change the properties of action potentials. The present paper firstly discusses the C-Fast transient currents affecting membrane capacitance and membrane potential, and then draws a conclusion that the changes of membrane potential affect the properties of action potential through analyzing the changes of membrane potential in H-H model. Based on this conclusion, we discuss the influence mechanisms mainly through the analysis of traditional C-fast compensation errors, and focus discussion on the shape of electrode capacitance affecting C-fast. This method can not only improve the compensation speed greatly, but also improve the compensation precision from the electrode shape as much as possible.
Action Potentials ; Electric Capacitance ; Ion Channels ; physiology ; Membrane Potentials ; Neurons ; cytology ; Patch-Clamp Techniques

It is very important to establish and execute the all -sided experimental animal quality monitoring in order to guarantee human health , animal health and welfare as well as the authenticity , validity, and repeatability of the experimental research results.Setting corresponding sentinel animals in the experiment can effectively monitor the quality of experimental animals.This article gives a general review of the selection of sentinel rats in the microbiological quality monitoring of the experiment animals , contact form and time between the sentinel rats and the rats being monitored , the placement of sentinel rats, and the number of rat cages being monitored by each cage of sentinel rats , as well as the test quantity, test frequency and the project.

Glioblastoma (GBM) is one of the most common tumors of the central nervous system, which is the most lethal brain cancer. GBM treatment is based primarily on surgical resection, combined with radiotherapy and chemotherapy. Despite the positive treatment, progression free survival and overall survival were not significantly prolonged because GBM almost always recurs. We are always looking forward to some new and effective treatments. In recent years, a novel treatment method called tumor treating fields (TTFields) for cancer treatment has been proposed. TTFields devices were approved by the Food and Drug Administration (FDA) for adjuvant treatment of recurrent and newly diagnosed GBMs in 2011 and 2015, respectively. This became the first breakthrough treatment for GBM in the past 10 years after the FDA approved bevacizumab for patients with relapsed GBM in 2009. This paper summarized the research results of TTFields in recent years and elaborated the mechanism of action of TTFields on GBM, including cell and animal experimental research, clinical application and social benefits.

Recently, some global cases of 2019 novel coronavirus (COVID-19) pneumonia have been caused by second- or third-generationtransmission of the viral infection, resulting in no traceable epidemiological history. Owing to the complications of COVID-19pneumonia, the first symptom and imaging features of patients can be very atypical and early diagnosis of COVID-19 infectionsremains a challenge. It would aid radiologists and clinicians to be aware of the early atypical symptom and imaging featuresof the disease and contribute to the prevention of infected patients being missed.

Objective To investigate the differential metabolites of lymph node metastasis in pancreatic ductal carcinoma (PDAC) and provide new ideas for the pathogenesis, early diagnosis and treatment of metastatic pancreatic cancer. Methods Forty serum specimens of patients with pancreatic ductal carcinoma were collected and divided into lymph node metastasis group (18 cases) and non-metastasis group (22 cases). Thirty-one serum specimens were also collected from the healthy control group. Liquid chromatographytandem mass spectrometry was used to analyze the differential metabolites and metabolic pathways between patients with PDAC and healthy controls as well as between lymph node metastasis and non-metastasis groups. Results Principal component analysis and partial least squares-discriminant analysis revealed statistically significant differences in metabolites and metabolic pathways between patients with PDAC and the healthy controls and between lymph node metastasis and non-metastasis groups. The differences in profiles were also statistically significant. Seventy-six different metabolites and 11 metabolic pathways were screened between patients with PDAC and the healthy controls, among which phenylalanine metabolism and histidine metabolism were the two most influential metabolic pathways. Four different metabolites were screened between lymph node metastasis and non-metastasis groups, and the expression of ethopropazine and phenylalanine were upregulated but the expression of tetrahydrodeoxycorticosterone and oxprenolol were downregulated. Conclusion Metabolites are significantly altered in the lymph node metastasis group of patients with PDAC compared with the non-metastasis group. Ethopropazine, phenylalanine, tetrahydrodeoxy corticosterone, and oxprenolol are potential biomarkers of lymph node metastasis in patients with PDAC.

Objective:This study aims to explore the pathogenic roles of protein S-nitrosylation modification in the development of severe acute pancreatitis, and provide new insights into the molecular mechanisms driving acute pancreatitis development.Methods:Thirty two Sprague Dawley (SD) rats were randomly divided into sham operation group, mild acute pancreatitis (MAP) group, severe acute pancreatitis (SAP) group and SAP + N-nitro-L-arginine methyl ester (L-NAME) group (treated with nitric oxide synthase inhibitor), 8 rats in each group. All rats were sacrificed to take blood from heart and pancreatic tissues 24 h after model construction. Total protein S-nitrosylation modification level in pancreatic tissues was quantitated by the biotin-switch method, followed by histological evaluation via hematoxylin and eosin (HE) staining. The serum endotoxin, D-lactic acid, diamine oxidase, interleukin-6 and tumor necrosis factor-ɑ(TNF-ɑ), amylase, alanine aminotransferase, urea nitrogen and calcium ions in rat were detected. Pearson correlation analysis was used to analyze the correlation between each index and protein S-nitrosylation.Results:Compared with the sham operation group, the modification level of protein S-nitrosylation in pancreatic tissue of MAP group increased significantly ( P<0.05); Compared with MAP group, the modification level of protein S-nitrosylation in pancreatic tissue of SAP group increased significantly ( P<0.05); Compared with SAP group, the modification level of protein S-nitrosylation in pancreatic tissue of SAP + L-NAME group decreased significantly ( P<0.05). HE staining showed that the degree of pancreatic necrosis and inflammatory cell infiltration in SAP + L-NAME group were significantly weaker than those in SAP group. The concentrations of serum endotoxin, diamine oxidase, D-lactic acid, IL-6 and TNF-ɑ, amylase, alanine aminotransferase, and urea nitrogen in the MAP group were significantly higher than those in the sham operation group (all P<0.05); The above indexes in SAP group were significantly higher than those in MAP group and sham operation group (all P<0.05); The above indexes in SAP + L-NAME group were significantly lower than those in SAP group (all P<0.05). The serum IL-6 and TNF-ɑ levels in rats with acute pancreatitis were positively correlated with protein S-nitrosylation in pancreatic tissue (all P<0.05). Conclusions:Protein S-nitrosylation modification plays essential roles in the development and progression of severe acute pancreatitis.

Objective To analyze the clinical value of immature granulocytes in peripheral blood for prediction of persistent systemic inflammatory response syndrome (SIRS) in patients with acute pancreatitis (AP). Methods 1 973 patients with AP in Hunan People's Hospital from 2012 to 2017 were retrospectively enrolled and divided by SIRS duration into the persistent SIRS group, temporary SIRS group and non-SIRS group. The independent risk factor for persistent SIRS in AP patients was evaluated by Logistic regression analysis, and predictive value of immature granulocytes for persistent SIRS in AP patients was analyzed by the receiver operating characteristic (ROC) curve. Results These 1 973 AP patients (1 165 males, 59.0%) with an average age of 49 (40, 60) years old, including 288 persistent SIRS, 189 temporary SIRS and 1 496 non-SIRS cases. There was no significant difference in gender, age and etiology among three groups. Compared with non-SIRS group, more severe symptoms were observed in the temporary and persistent SIRS groups. Moreover, The acute physiology and chronic health evaluation Ⅱ(APACHEⅡ), CT severity index (CTSI), multiple organ failure (MOF) and acute respiratory distress syndrome (ARDS) incidence, mortality and C-reactive protein (CRP), white blood cell count (WBC), procalcitonin (PCT) and immature granulocytes in persistent SIRS group were further higher than those in the temporary SIRS group [APACHEⅡ: 9 (6, 12) vs. 5 (3, 7), CTSI: 6 (4, 6) vs. 4 (3, 6), MOF incidence: 92.0% vs. 32.8%, ARDS incidence: 39.9% vs. 10.1%, morbidity: 11.1% vs. 4.2%, CRP (mg/L): 25.00 (0.80, 212.25) vs. 0.80 (0.80, 123.50), WBC (×109/L): 15.17±6.78 vs. 14.84±5.86, PCT (μg/L): 0.23 (0.10, 1.76) vs. 0.10 (0.10, 0.31), immature granulocytes: 1.95 (0.90, 4.95) % vs. 0.80 (0.40, 2.10) %, all P < 0.05]. Logistic regression analysis showed that besides pancreatic necrosis, WBC and CRP, immature granulocyte was an independent risk factor for persistent SIRS associated with AP [odds ratio (OR) = 1.844, 95% confidence interval (95%CI) = 1.372-2.220]. ROC curve showed that immature granulocytes had better predictive value for persistent SIRS, the area under the curve (AUC) was 0.806, which was significantly higher than the APACHEⅡ (AUC = 0.783), CTSI (AUC = 0.752), PCT (AUC = 0.676), CRP (AUC = 0.677), WBC (AUC = 0.644). The cut-off value of immature granulocyte was 0.65%, the sensitivity was 84.0%, the specificity was 66.3%, the positive predictive value was 62.4%, and the negative predictive value was 76.3%. Conclusion Immature granulocyte in peripheral blood is a potential indicator for persistent SIRS in AP patients.

OBJECTIVE: To clarify the effect of glycosylphosphatidylinositol-specific phospholipase D (GPIPLD) on hepatoma cells HepG2 and the possible molecular mechanism. METHODS: MTT, fluorescent staining and Western blot were applied to analyze the effect and molecular mechanism of GPI-PLD on hepatoma cells by transfected high expression GPI-PLD model. We inoculated HepG2 in nude mice models to further clarify the effect of GPI-PLD on hepatoma cells in vivo. RESULTS: Compared with the control groups, PI3K-Akt signaling pathway activity and proliferation of hepatoma cells were significantly inhibited in the GPI-PLD group. Nude mice models showed that the tumor growth and tumor weight [(1.87 ± 0.09) g] of the GPI-PLD group were significantly less than those of the blank control group [(2.20 ± 0.17) g] and the negative control group [(2.15 ± 0.09) g]. AST, ALT and AFP serum concentration in the GPI-PLD group were significantly lower than those of the control groups (P<0.05). CONCLUSION GPI-PLD can inhibit the proliferation of hepatoma cells and growth in vivo, and promote the apoptosis of hepatoma cells by reducing the activity of PI3K-Akt signaling pathway.
Animals ; Apoptosis ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Line ; Down-Regulation ; Hep G2 Cells ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Mice ; Mice, Nude ; Phosphatidylinositol 3-Kinases ; Phospholipase D ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; Transfection

【Objective】 To study the annual financial expenditure in blood stations with different scales, and to establish the regression equation between blood collection units and total expenditure. 【Methods】 The annual total expenditure, the per capita cost of serving population, as well as the collection units of whole blood and apheresis platelet of 24 blood stations were collected. The financial expenditure required for collecting 10 000U blood was calculated.The statistical analysis was carried out with SPSS statistical software. 【Results】 From 2017 to 2020, the total annual financial expenditure of 24 blood stations showed an upward trend. The total expenditure among blood stations was different. The per capita cost of servicing population in the areas where the 24 blood stations were located had been increasing year by year. The 24 blood stations were divided into two grades according to the blood collection volume as 50 000 U, and the relationship equation between the blood collection volume and the annual total expenditure had been established. After testing, each equation was effective(P<0.05); There was no difference in the financial expenditure required for collecting 10 000U blood among blood stations with different scales. 【Conclusion】 From 2017 to 2020, the blood stations with an annual collection volume more than 50 000 U demonstrated a higher financial expenditure and the per capita cost of serving population than those <50 000 U. The blood collection volume of blood stations is significantly correlated with the annual total expenditure and the per capita cost of serving population.