Induction of MET Receptor Tyrosine Kinase Down-Regulation through Antibody-Mediated Receptor Clustering

The proto-oncoprotein MET is a receptor tyrosine kinase that plays a key role in cancer cell growth and invasion. We have used fluorescence-tagged antibodies to activate MET in live serum-starved glioblastoma cells and monitor the fate of antibody-bound MET receptor in single cell-based assays. We found that the antibodies induced rapid and transient formation of highly polarized MET clusters on the plasma membrane and promoted the activation of MET, resembling the initial effects of binding to its ligand, HGF. However, the antibody-induced clustering and activation of MET led to the rapid removal of the receptor from cell surface and altered its intracellular processing, resulted in rapid degradation of the receptor. Consequently, while cells pre-treated with HGF remain competent to respond to further HGF stimulation, cells pre-treated with antibodies are refractory to further HGF stimulation due to antibody-mediated MET depletion. Removal of MET by sustained treatment of antibodies blocked cancer cell migration and invasion. Our studies reveal a novel mechanism to alter the recycling process of MET in glioblastoma cancer cells by promoting the receptor degradation through a proteasome-sensitive and lysosome-dependent pathway through the ligand-independent activation of MET using anti-MET antibodies

ADAPTIVE FAULT DETECTION AND CONDITION MONITORING OF INDUCTION MOTOR

Master'sMASTER OF ENGINEERIN

Experimental study on the isothermal adsorption of methane gas in natural gas hydrate argillaceous silt reservoir

Gas hydrate occurs in hydrate reservoirs in a solid form. At present, the conventional exploitation method is to decompose solid hydrate and then extract the resulting gaseous gas. Therefore, the occurrence law of gas in a reservoir is of great significance for the study of gas hydrate seepage and productivity. Adsorption, as an important occurrence mode, has been widely concerned in the research on shale reservoirs. However, the adsorption problem in hydrate reservoirs has not received enough attention. In this paper, the existence of adsorption in a hydrate reservoir has been experimentally confirmed for the first time. Based on the argillaceous silt of a natural gas hydrate reservoir in the South China Sea, the pore structure and adsorption characteristics of argillaceous silt were experimentally studied, and the results were compared with those of typical shale reservoirs. The modified Langmuir and Dubinin-Radushevich equations were used to fit the adsorption data, and the suitable adsorption model of argillaceous silt was established and optimized. The results showed that the inhomogeneous slit pores are dominant in argillaceous silt, and they are formed by the accumulation of lamellar particles. Compared with shale, the adsorption capacity of argillaceous silt is weak under the same conditions. However, adsorption is a spontaneous exothermic reaction, and the ambient temperature of argillaceous silt is much lower than that of shale. Therefore, it is possible for argillaceous silt to achieve an adsorption capacity comparable to that of shale. The modified Langmuir model can be used to simulate argillaceous silt adsorption at low pressure, while under medium and high pressures, the modified Dubinin-Radushevich model performs better. The adsorption capacity of argillaceous silt is affected by moisture. When the water content is 20%, the Langmuir adsorption capacity and the Dubinin-Radushevich maximum adsorption capacity decreases by 21.88% and 13.67%, respectively, which is far less than the influence of moisture on shale adsorption, as reported in the literature.Cited as: Qi, R., Qin, X., Lu, C., Ma, C., Mao, W., Zhang, W. Experimental study on the isothermal adsorption of methane gas in natural gas hydrate argillaceous silt reservoir. Advances in Geo-Energy Research, 2022, 6(2): 143-156. https://doi.org/10.46690/ager.2022.02.0

Recital: Opera Practicum, November 19, 2009

Kemp Recital HallNovember 19, 2009Friday Evening4:30 p.m

Risk factors for marginal ulcer after gastric bypass surgery for obesity:A population-based cohort study

ObjectiveThis study aimed to assess risk factors for developing marginal ulcer (MU) after gastric bypass (GBP) surgery for obesity.BackgroundMU is a common and potentially serious complication of GBP surgery, little is known about its etiology.MethodsThis population-based cohort study of GBP in 2006-2011 evaluated MU in relation to diabetes, hyperlipidemia, hypertension, chronic obstructive pulmonary disease (COPD), ulcer history, use of proton pump inhibitors (PPIs), aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and selective serotonin reuptake inhibitors (SSRIs). Multivariable Cox proportional hazard regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for confounding.ResultsAmong 20,294 GBP patients, diabetes and peptic ulcer history entailed statistically significantly increased risk of MU (HR = 1.26, 95% CI 1.03-1.55 and HR  =  2.70, 95% CI 1.81-4.03), although hyperlipidemia, hypertension, and COPD did not. PPI users had an increased HR of MU (HR  =  1.37, 95% CI 1.17-1.60). Aspirin and NSAID consumption less than or equal to median entailed decreased HRs of MU (HR  =  0.56, 95% CI 0.37-0.86 and HR  =  0.30, 95% CI 0.24-0.38), although aspirin and NSAID users more than median had an increased risk and no association with MU, respectively (HR  =  1.90, 95% CI 1.41-2.58 and HR  =  0.90, 95% CI 0.76-1.87). The use of SSRI less than or equal to median had a decreased risk of MU (HR  =  0.50, 95% CI 0.37-0.67), although use more than median entailed increased HR (HR  =  1.26, 95% CI 1.01-1.56).ConclusionsDiabetes and peptic ulcer history seem to be risk factors for MU, but not hyperlipidemia, hypertension, or COPD. Limited doses of aspirin, NSAIDs, and SSRIs might not increase the risk, although higher doses of aspirin do. The association with PPI could be due to confounding by indication