BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon e...BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.展开更多
The work considers modification of the Best–Worst Scaling(BWS)to the so-called System 1(S1)approach.S1 was described by D.Kahneman as a spontaneous and automatic reaction by an unconsciousway in which human decision-...The work considers modification of the Best–Worst Scaling(BWS)to the so-called System 1(S1)approach.S1 was described by D.Kahneman as a spontaneous and automatic reaction by an unconsciousway in which human decision-makers choose among multiple alternatives.Application of S1 can be seen as a simplified BWS for data eliciting and express analysis of prioritization between many compared items.In S1,a respondent picks the items with which she feels“happy”,and those can be one,several,all,or none items in a task.Estimation of utilities is performed by multinomial-logit modeling with different optimization criteria which produce parameters of the models and choice probabilities of the items.Numerical examples by marketing research data are encouraging and demonstrating that spontaneous choice decisions can make S1 approach very fast,efficient,and convenient for express analysis of items prioritization,especially for big data.展开更多
基金supported in part by a BMBF grant(TOMCAT)given to H.K.the Molecular Imaging North Competence Center(MOIN-CC)
文摘BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.
文摘The work considers modification of the Best–Worst Scaling(BWS)to the so-called System 1(S1)approach.S1 was described by D.Kahneman as a spontaneous and automatic reaction by an unconsciousway in which human decision-makers choose among multiple alternatives.Application of S1 can be seen as a simplified BWS for data eliciting and express analysis of prioritization between many compared items.In S1,a respondent picks the items with which she feels“happy”,and those can be one,several,all,or none items in a task.Estimation of utilities is performed by multinomial-logit modeling with different optimization criteria which produce parameters of the models and choice probabilities of the items.Numerical examples by marketing research data are encouraging and demonstrating that spontaneous choice decisions can make S1 approach very fast,efficient,and convenient for express analysis of items prioritization,especially for big data.
