Study on magnetic resonance imaging,DWI features of patients with newly diagnosed cervical cancer and the ;correlation with clinical pathological characteristics / 中国基层医药

Objective To analyze the characteristics of magnetic resonance imaging(MRI)and DWI in newly diagnosed patients with cervical cancer,and to investigate the correlation between the clinical pathological features and the clinical pathological characteristics.Methods 100 cases of newly diagnosed cervical cancer were selected as the research subjects.All patients received magnetic resonance plain scan,DWI examination,MRI features of cervical carcinoma were observed,its ADC value and MVD were measured,ADC and MVD in different stages of cervical cancer were compared,its correlation was analyzed.Results The signal features of the lesions were as long as T2 , slightly longer T1 signal.The pressure sequence was obviously high signal.Compared with the surrounding tissue,DWI sequence was high signal.In the diagnosis and staging of Ⅲ and Ⅳstage lesion,the MRI diagnosis was right,MRI of the 9 cases of Ⅱstage lesion was misdiagnosed as Ⅰstage lesion,7 cases of Ⅰstage lesion were misdiagnosed as Ⅱstage lesion,compared with the postoperative pathologic staging,the diagnostic accuracy was 84%.There were signifi-cant differences in ADC value[(0.917 ±0.055)s/mm2 vs.(0.911 ±0.044)s/mm2 vs.(0.887 ±0.047)s/mm2 vs. (0.815 ±0.043)s/mm2 ]and MVD[(27.38 ±5.66)vs.(29.54 ±7.32)vs.(34.46 ±8.92)vs.(35.26 ±8.84)] between different stages of cervical cancer(F =3.024,2.941,all P <0.05),The ADC value of cervical carcinoma inⅢ and Ⅳstage lesion was significantly lower than that of the Ⅰ and Ⅱstage lesion of cervical cancer,MVD was significantly higher than that of the Ⅰ and Ⅱstage lesion of cervical cancer,the differences were statistically signifi-cant(t =2.992,2.976,3.954,3.689,all P <0.05).By Pearson correlation analysis,significantly negative correlation was found between ADC value and MVD value of cervical cancer(r =-0.678,P =0.021).Conclusion The MRI and DWI images of cervical carcinoma are characteristic,there was a significant correlation between clinical stage and MVD.

Clinical value of magnetic resonance diffusion weighted imaging and dynamic enhanced imaging in endome-trial carcinoma staging / 中国基层医药

Objective To study the value of magnetic resonance diffusion weighted imaging (DWI)and dynamic enhanced imaging (DCE)in endometrial carcinoma staging.Methods 200 cases with endometrial carcinoma were selected,DWI and DCE were given before operation.The diagnostic value of two kinds of examination methods for the diagnosis of endometrial carcinoma in general and basic level was compared.Results The overall accuracy of muscle invasion of magnetic resonance DWI was 91.5%(183 /200),which was significantly higher than 77.5%(155 /200)of magnetic resonance DCE,the difference was statistically significant (χ2 =11.231,P <0.05 ).The accuracy,sensitivity and positive predictive value of the magnetic resonance DWI superficial and deep muscular layer were significantly higher than those of the magnetic resonance DCE (χ2 =9.283,8.231,9.021,8.927,8.142, 9.405,all P <0.05).Compared with pathological results,Kappa value of magnetic resonance DWI was 0.807,Kappa value of magnetic resonance DCE was 0.587.Conclusion Magnetic resonance DWI compared with magnetic reso-nance DCE,the accuracy and sensitivity of the infiltration of endometrial carcinoma was higher.

Improving maltodextrin specificity by site-saturation engineering of subsite +1 in cyclodextrin glycosyltransferase from Paenibacillus macerans / 生物工程学报

By engineering the subsite +1 of cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans, we improved its maltodextrin specificity for 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G) synthesis. Specifically, we conducted site-saturation mutagenesis on Leu194, Ala230, and His233 in subsite +1 separately and gained 3 mutants L194N (leucine --> asparagine), A230D (alanine --> aspartic acid), and H233E (histidine --> glutamic acid) produced higher AA-2G yield than the wild-type and the other mutant CGTases. Therefore, the 3 mutants L194N, A230D, and H233E were further used to construct the double and triple mutations. Among the 7 obtained combinational mutants, the triple mutant L194N/A230D/H233E produced the highest AA-2G titer of 1.95 g/L, which was increased by 62.5% compared with that produced by the wild-type CGTase. Then, we modeled the reaction kinetics of all the mutants and found a substrate inhibition by high titer of L-AA for the mutants. The optimal temperature, pH, and reaction time of all the mutants were also determined. The structure modeling indicated that the enhanced maltodextrin specificity may be related with the changes of hydrogen bonding interactions between the side chain of residue at the three positions (194, 230 and 233) and the substrate sugars.

Hypoxic preconditioning effects on the ability of bone marrow mesenchymal stem cells tolerant to ischemia and hypoxia / 中国组织工程研究

BACKGROUND:According to the previous studies, it is known that bone marrow mesenchymal stem cells live in the physiological environment of lower oxygen concentration compared with the common culture concentration (20%-21%). Hypoxia can promote bone marrow mesenchymal stem cells proliferation and maintain the characteristics of differentiation potential. OBJECTIVE:To understand the biological characteristics of bone marrow mesenchymal stem cells after hypoxic preconditioning, and search for in vitro basis for bone marrow mesenchymal stem cells therapy in vivo with hypoxic preconditioning strategy. METHODS:After passage and inoculation, bone marrow mesenchymal stem cells were cultured in the hypoxic incubator (1%O2, 5%CO2). Bone marrow mesenchymal stem cells cultured in the normoxic incubator (20%O2, 5%CO2) served as controls. RESULTS AND CONCLUSION:Compared with bone marrow mesenchymal stem cells cultured under normoxia (20%O2), bone marrow mesenchymal stem cells cultured under hypoxia (1%O2) began to display exponential growth phase after a longer incubation period. Hypoxia (1%O2) was not the lethal condition for bone marrow mesenchymal stem cells. cellsurvival rates of both groups reduced over time, while those of bone marrow mesenchymal stem cells cultured under normoxia reduced faster (P<0.05). Surface markers expression of bone marrow mesenchymal stem cells, including CD29(+), CD90(+), CD31(-), CD45(-), after hypoxic preconditioning did not change greatly when compared with the results before hypoxic preconditioning. The hypoxia preconditioned bone marrow mesenchymal stem cells did not differentiate into vascular endothelial cells. Hypoxia-inducible factor-1αprotein expression was promoted after 24 hours to 48 hours hypoxic preconditioning, and there was significant difference between the two time points (P<0.05). Vascular endothelial growth factor expression increased at both transcriptional and protein levels after 48 hours hypoxic preconditioning (P<0.05). Culture under hypoxia (1%O2) does not produce a lethal effect on bone marrow mesenchymal stem cells and can be used for hypoxic preconditioning. Surface markers of bone marrow mesenchymal stem cells after 48 hours hypoxic preconditioning exhibit no great changes and the hypoxia preconditioned bone marrow mesenchymal stem cells maintain the characteristics of stemness. Hypoxic preconditioning can promote the ability of bone marrow mesenchymal stem cells to survive under hypoxia/ischemic condition. The activation of the hypoxic response signal transduction pathway through hypoxia-inducible factor-1αmay explain this.