This article discussed the problems in teaching medical imaging from such aspects as teaching contents,methods,conditions and teacher cultivation on the basis of our teaching practice.

Objective To study the Effect of acute peripancreatitc fluid collection and pancreatic necrosis to the prognosis of acute pancreatitis.Methods Retrospectively analyzing the prognostic effect of acute peripancreatitc fluid collection and pancreatic necrosis according to the early Computed-Tomograghy of 323 consecutive acute pancreatitis patients from Jan 2003 to Dec 2007,the end points are systemic inflammation response syndrome ( SIRS),pancreatic infection,and mortality.Results Within 5d after onset,97 of 323 cases (30%) presented with SIRS and lasted more than 2d,12 cases (3.7%) occurred pancreatic infection during middle or late phase,14 cases died,the mortality is 4.3%.141 of 323 cases (43.7%) who had acute peripancreatic fluid collection presented with SIRS,acute peripancreatic fluid collection correlated significantly with the occurrence of SIRS,P ＜ 0.05.227 cases (277/323,85.8%) had no pancreatic necrosis,no pancreatic infection occurred,46 cases (46/323,14.2% )had pancreatic necrosis,pancreatic necrosis correlated significantly with pancreatic infection,P ＜ 0.05.Conclusions Acute poripancreafic fluid collection and pancreatic necrosis had different prognostic effect to acute pancreatitis.Acute peripancreatic fluid collection correlated well with the occurrence of SIRS during the early phase;Pancreatic necrosis may be infected during middle or late phase of acute pancreatitis,more extent of pancreatic necrosis,more possible that pancreatic infection will occur.

Objective To sudy the changes in mTOR signaling pathway in childhood aplastic anemia(AA) by detecting the expression levels of the molecules of mTOR signaling pathway in T cells,and to explore immunologoical pathogenesis of AA in children from T cell intracellular signal transduction pathway.Methods Peripheral blood samples were collected from 16 newly diagnosed severe AA(SAA) patients and 8 patiens treated with effective immunosuppressive therapy,and the findings were compared with those of 17 healthy children (normal controls) and CEM cells (positive controls).The expressions of p-Akt,p-TSC2,p-mTORC1,p-4EBP1,p-p70S6K in CD3 + T cells in peripheral blood were detected by flow cytometry(FCM).Results 1.The expressions of p-Akt,p-TSC2,p-mTORC1,p-4EBP1,pp70S6K of the newly diagnosed SAA group were higher than those of the normal control group (P ＜ 0.05),but were lower than the postive control group (CEM group) (P ＜ 0.05).The mean fluorescence intensity (MFI) of p-Akt of three groups was 8.04 ± 3.78,2.59 ± 1.01 and 20.23 ± 8.98 respectively ;p-TSC2 was 49.73 ± 19.49,16.10 ± 8.04 and 101.05 ± 29.78 respectively ; p-mTOR was 13.90 ± 9.32,2.92 ± 1.09 and 34.3 ± 19.03 ;p-4EBP1 was 142.69 ± 53.36,26.91 ± 13.70,256.01 ± 53.79 ; p-p70S6 K were 17.67 ± 10.48,3.69 ± 2.22,31.73 ± 12.85 respectively.2.The expressions of p-Akt,p-TSC2,p-mTORC1,p-4EBP1,p-p70S6K of the effective treatment groups were lower than those of the newly diagnosed SAA group (P ＜ 0.05) ; the expressions of p-Akt,p-TSC2,p-mTORC1,p-p70S6K were similar to those of the normal control group(P ＞ 0.05),but the expressions of p-4EBP1 were higher(P ＜ 0.05).The MFI was followed by 3.28 ± 1.27,16.50 ± 10.91,3.54 ± 1.66,74.89 ± 49.69 and 4.21 ± 1.69.Conclusions 1.The expressions of p-Akt,p-TSC2,p-mTORC1,p-4EBP1,p-p70S6K were increased in the newly diagnosed SAA patients,the mTOR signaling pathway was activated in SAA patients.2.The expressions of p-Akt,p-TSC2,p-mTORC1,p4EBP1,p-p70S6K were lower than those of the newly diagnosed SAA patients.The degree of activation of mTOR signaling pathway was associated with disease status.The signaling pathways may be involved in the T cells of AA of the immune abnormalities.

Objective The aim of this study was to investigate the aquaporin-4(AQP4) expression in the ischemic penumbra tissues.Methods Thirty-six Wistar rats were divided into 7 groups randomly, including control group(n=6) and occluded groups(n=30). The occluded groups were studied after the right middle cerebral artery of the rats unilaterally occluded(MCAO) at an interval of 15 min, 30 min, 1 h, 3 h, 6 h and 24 h, respectively(n=5 for each group). The operation process of the control group was the same as the occluded group except occluded MCAO. Then all rats were imaged with T_1WI, T_2WI and diffusion weighted-imaging(DWI). The brain tissue, according to the method by LIU Meili reported, was regarded as the area of the graphic penumbra. The relative apparent diffusion coefficient of the graphic-penumbra (rADC_1) and the center infarction(rADC_2)(ratios between the values of the occluded side and the opposite side) were calculated. The animals were sacrificed and perfused with the mixture solution consisting of TTC at different time intervals. The graphic-penumbra of the biggest layer of the ischemic cerebral tissue which corresponded to the DWI was examined with immunohistochemistry and RT-PCR. Meanwhile, histologic examination was performed at same site of the lesion. Results There were no significant changes on MRI, the relative apparent diffusion coefficient and the expression of the AQP4. The abnormal high intensity was found on DWI at 15 min after MCAO. T_2WI detected the lesion at 1 h after MCAO. The value of the rADC_1 decreased within 24 h after MCAO in ischemic penumbra, especially, it descended quickly within 1 h after MCAO, from(70.4?6.9)% at 15 min to(53.5?10.9)% at 1 h. Whereas, in the infarct tissue, the changes of the rADC_2 had a rule of decrease from(71.5?6.6)% at 15 min to(45.7?10.5)% at 3 h at first time, and then follow an increasing up to(78.7?11.5)% at 24 h after MCAO. The expression of AQP4 increased gradually within 24 h after MCAO, from 0.42?0.05 at 15 min to 1.18?0.12 at 24 h, it showed negative relationship with the rADC_1 in the ischemic penumbra (r= -0.966,P

OBJECTIVETo revalidate the conversion factor（CF）for the conversion of BCR-ABL （P210）transcript levels to the international scale（BCR- ABLIS）in chronic myeloid leukemia（CML） which validated before.

METHODSPeking University People's Hospital（PKUPH）prepared the exchange samples for revalidation of CFs of 15 laboratories which validated nine or eighteen months ago. The fresh BCR-ABL（P210）（+）bone morrow or peripheral blood nucleated cells were diluted with BCR-ABL （P210）（-）cells to achieve different BCR- ABL levels, totally 16 sets and 24 samples per set were prepared. TRIzol reagent was added in each tube. Each laboratory tested BCR-ABL transcript levels of one set of samples. Agreement between BCR-ABLIS of each laboratory and PKUPH was assessed by the Bland- Altman method. For laboratories which did not meet the criteria of revalidation, linear regression equation was derived after the samples with maximum BCR-ABL deviation were removed until R²>0.98, then new CF was calculated.

RESULTS10 laboratories met the revalidation criteria with both bias within ±1.4 fold and 95% limits of agreement within ±6 folds, and their CFs still could be used for accurately conversion of BCR-ABLIS. New CFs were recalculated as of 1.8-6.3 folds of their previous CFs in 5 laboratories not met the criteria.

CONCLUSIONRevalidation of CF by sample exchange among laboratories was necessary for accurate and continuous application of BCR-ABLIS, which not only tested the validity of CF acquired before but also calculated new available CFs for those with invalid CFs.

Bone Marrow Cells ; Fusion Proteins, bcr-abl ; genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; diagnosis ; genetics