Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma tre...Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma treated with rituximab and discuss the incidence, mechanism, influence factors, specific markers, prognosis and treatment of this disease. These results suggested that a post-relapse biopsy after rituximab treatment shguld be performed. CD79a and Pax-5 should be used as the first-line B lineage-specific markers for these patients. Though mechanisms of CD20 decrement are not fully elucidated, the down-regulation of CD20 mRNA is the most probable hypothesis. Recently various new agents are developed, but the prognosis is still poor. Further studies for new treatments are needed.展开更多
In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements（REEs） in gastrointestinal（GI） tract, using La Cl3 and La Cit as representative compounds. Artificia...In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements（REEs） in gastrointestinal（GI） tract, using La Cl3 and La Cit as representative compounds. Artificial gastric and intestinal fluids were used to simulate the environment of the digestive tract in vivo. The inductively coupled plasma mass spectrometry（ICP-MS） result showed that more than 99.9% of La Cl3 and La Cit formed precipitation in artificial intestinal fluid, with the average size distribution of 200 nm（2-h incubation） increasing to 600 nm（24-h incubation） determined by dynamic light scattering（DLS）, indicating the aggregation of the particles. The Fourier transform infrared spectroscopy（FTIR） analysis demonstrated that the constituents of these particles were mainly in the form of lanthanum phosphates. To explore the transport mechanism of REEs in GI tract, the mice Peyer＇s patches（PPs） and intestinal epithelium were separated to evaluate the content of lanthanum by ICP-MS following oral administration with 2 or 100 mg/kg/day of La Cit for 7 d. The results showed that the amount of lanthanum phosphate particles absorbed by PPs was significantly greater than that of intestinal epithelium, indicating that lanthanum particles might be phagocytosed mainly by M cells located in the follicle-associated epithelium（FAE） overlying PPs. Furthermore, Caco-2 cell monoculture and Caco-2/Raji B cell coculture models were established to simulate intestinal epithelial cells and FAE, respectively. The result showed that the transport of lanthanum in Caco-2/Raji B coculture model was significantly higher than that in Caco-2 monoculture model（about 60 times higher）, and the level of lanthanum in the basal compartment of Caco-2 monoculture model was very low, supporting that M cells were the main route for lanthanum phosphate particles to be transported and absorbed. Taken together, these data suggested that La Cl3 and La Cit in GI tract were absorbed mainly via M cells with lanthanum phosphates as transformed species. The obtained results would provide the theoretical basis for the rational application of REEs in agriculture and medicine.展开更多
文摘Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma treated with rituximab and discuss the incidence, mechanism, influence factors, specific markers, prognosis and treatment of this disease. These results suggested that a post-relapse biopsy after rituximab treatment shguld be performed. CD79a and Pax-5 should be used as the first-line B lineage-specific markers for these patients. Though mechanisms of CD20 decrement are not fully elucidated, the down-regulation of CD20 mRNA is the most probable hypothesis. Recently various new agents are developed, but the prognosis is still poor. Further studies for new treatments are needed.
基金National Natural Science Foundation of China(Grant No.21277006 and 21671009)
文摘In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements（REEs） in gastrointestinal（GI） tract, using La Cl3 and La Cit as representative compounds. Artificial gastric and intestinal fluids were used to simulate the environment of the digestive tract in vivo. The inductively coupled plasma mass spectrometry（ICP-MS） result showed that more than 99.9% of La Cl3 and La Cit formed precipitation in artificial intestinal fluid, with the average size distribution of 200 nm（2-h incubation） increasing to 600 nm（24-h incubation） determined by dynamic light scattering（DLS）, indicating the aggregation of the particles. The Fourier transform infrared spectroscopy（FTIR） analysis demonstrated that the constituents of these particles were mainly in the form of lanthanum phosphates. To explore the transport mechanism of REEs in GI tract, the mice Peyer＇s patches（PPs） and intestinal epithelium were separated to evaluate the content of lanthanum by ICP-MS following oral administration with 2 or 100 mg/kg/day of La Cit for 7 d. The results showed that the amount of lanthanum phosphate particles absorbed by PPs was significantly greater than that of intestinal epithelium, indicating that lanthanum particles might be phagocytosed mainly by M cells located in the follicle-associated epithelium（FAE） overlying PPs. Furthermore, Caco-2 cell monoculture and Caco-2/Raji B cell coculture models were established to simulate intestinal epithelial cells and FAE, respectively. The result showed that the transport of lanthanum in Caco-2/Raji B coculture model was significantly higher than that in Caco-2 monoculture model（about 60 times higher）, and the level of lanthanum in the basal compartment of Caco-2 monoculture model was very low, supporting that M cells were the main route for lanthanum phosphate particles to be transported and absorbed. Taken together, these data suggested that La Cl3 and La Cit in GI tract were absorbed mainly via M cells with lanthanum phosphates as transformed species. The obtained results would provide the theoretical basis for the rational application of REEs in agriculture and medicine.
