Prokaryotic expression, purification, and immunogenicity analysis of Mycobacterium tuberculosis specific excretive proteins / 中国医学科学院学报

<p><b>OBJECTIVE</b>To obtain the recombinant rv1837c and rv3803c of Mycobacterium tuberculosis using gene engineering technology and explore their prokaryotic expression, purification, and immunogenicity.</p><p><b>METHODS</b>The Mycobacterium tuberculosis rv1837c and rv3803c genes were amplified by polymerase chain reaction, and then cloned into the vector pTA2, followed by the subclone into the expression vector pET30a (+). The resulting plasmids, named pET30a (+): rv1837c and pET30a (+): rv3803c, encode recombinant protein containing a hexa-histidine tag on its N-terminus. pET30a (+): rv1837c and pET30a (+): rv3803c were introduced into E. coli BL21 (DE3) by transformation respectively, and the recombinant gene was induced with 0.4 mmol/L isopropyl-D-thiogalactopyranoside. The expressed products were identified by Western blot with hexa-histidine tag antibody and serum from tuberculotic patients. The histidine tagged protein was purified by nickel nitrilotriacetic acid His-Bind resin. Rabbits were immunized with purified recombinant Rv1837c and Rv3803c proteins. Then the purified recombinant Rv1837c and Rv3803c proteins were used to detect antibody in rabbit serum, which had been immunized by Western blot.</p><p><b>RESULTS</b>After transformation of the E. coli and induction with 0.4 mmol/L of isopropyl-D-thiogalactopyranoside, recombinant target proteins Rv1837c (relative molecular mass: 92000) and Rv3803c (relative molecular mass: 38 000) were expressed in pET30a (+): rv1837c and pET30a (+): rv3803c system. The expressed protein existed in cytoplasm in an unsoluble form and amounted to 30% and 50% of the total proteins of E. coli. The purity of the purified protein reached 90%. The immunogenicity of the recombinant proteins Rv1837c and Rv3803c was strong, as identified by Western blot.</p><p><b>CONCLUSION</b>The prokaryotic expression recombinant plasmids pET30a (+): rv1837c and pET30a (+): rv3803c was successfully constructed and the recombinant proteins Rv1837c and Rv3803c were obtained, which laid a basis for the optimized diagnosis of active tuberculosis.</p>

Diagnostic value of full-field digital mammography for breast carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the diagnostic value of full-field digital mammography for breast cancer.</p><p><b>METHODS</b>The clinical data and mammograms of 230 patients with breast diseases between January 2008 and July 2008 were collected and reviewed. Craniocaudal (CC) and mediolateral oblique (MLO) view mammograms were performed in all patients before surgery. Three experienced radiologists in breast imaging assessment analyzed and classified all the mammograms according to breast imaging reporting and data system (BI-RADS). The sensitivity, specificity and accuracy were evaluated according to their pathological diagnosis. The reasons resulting in false-negative and false-positive diagnosis were also analyzed.</p><p><b>RESULTS</b>Of the 238 samples, 130 had a malignant breast tumors and 108 cases of benign breast lesions. One hundred and nine of the 130 malignant breast tumors were invasive ductal carcinoma. Fifty-seven of the 108 benign breast lesions were breast adenosis. Masses or masses with microcalcification were the most frequently seen signs of the malignant tumors, accounting for 40.8% and 20.8%, respectively. The sensitivity, specificity and accuracy of FFDM in detecting breast carcinoma were 90.8%, 87.0% and 89.1%, respectively. The false-negative signs including negative X-ray finding (5 cases) and focal asymmetric densities (4 cases). The false-positive signs were masses with spiculate, indistinctive or lobulated margin leading to misdiagnosing the lesions as malignant tumors.</p><p><b>CONCLUSION</b>Full-field digital mammography (FFDM) is helpful in detection of breast cancers in women, with a higher sensitivity, specificity and accuracy, and has an important clinical application value.</p>

MR imaging evalution of ductal carcinoma in situ and ductal carcinoma in situ with small invasive foci of breast / 中华放射学杂志

Objective To retrospectively assess diagnostic accuracy of magnetic resonance imaging (MRI)in preoperative assessment of local extent of breast ductal carcinoma in situ(DCIS)and DCIS with small invasive foci,compared with the mammography and ultrasonography(US)imagings.Methods Results of MRI,mammography,and US imaging from 17 consecutive women with known breast DCIS and DCIS with invasive foci were analyzed,and then compared with pathologic examination.Results(1) Fourteen lesions showed enhancement on dynamic breast MRI,of which 11 lesions were no-mass-like enhancement.Six of 11 lesions appeared segmental enhancement,and 2 were regional enhancement.Ductal and multiple focal areas enhancement were 1 case respectively.Symmetric diffuse enhancement in bilateral breast was showed in 1 patient.Ductal dilation was visible in ipsilateral breast on pre-contrast MRI in 2 cases,which manifested bloody nipple discharge in clinical examination,and duct enhanced on post- contrast imaging in one of them.Two lesions appeared mass enhancement with irregular shape and homogeneous signal.Linear enhancement surrounding the oval homogeneous mass with smooth margin found in 1 case.(2)Thirteen of 17 patients underwent bilateral mammography.There were various findings in mammograms,including microcalcifications(6 cases),normal mammograms(2 cases),calcifications with other appearance(2 cases),and non-calcification abnormity(3 cases).In 8 lesions with calcifications, 5 were noted higher probability of malignancy calcifications and 3 intermediate concern calcifications. Calcifications distributed clustered(5 cases),regional(2 cases)and diffuse(1 case)shape.(3)Sixteen of 17 patients were performed breast US examination.Eleven lesions,which were correct diagnosed, appeared higher echo spots within irregular lower echo area.One lesion diagnosed benign and 4 were negative on US examination.(4)Regarded the size measured on pathologic examination as golden standard, accordance of lesion extent was 13 of 17 case in MRI,7 of 13 in mammography,and 7 of 16 in US.There were 2 lesions overestimation of extent in MRI,3 in mammography,and 2 in US.Underestimation of extent showed 1 case and 3 cases in mammography and US imaging respectively.The difference was not significant (P = 0.161).Conclusion The MR imaging features of DCIS and DCIS with small invasive loci were characteristic.The combination of MRI and mammography could improve diagnostic accuracy.

The X-ray features of breast ductal carcinoma in situ and its small invasive foci and correlation between mammographic features and prognostic biologic factors / 中华放射学杂志

Objective To retrospectively evaluate the mammographic features of breast ductal carcinoma in situ (DCIS)and DCIS with small invasive foci,and to analyze the correlation between the mammographic findings and the prognostic biologic factors.Methods The mammographic examination was performed in 95 consecutive women with breast DCIS(n = 50)and DCIS with invasive foci(n = 45 ).The prognostic biologic factors including progesterone receptor(PR),C-erbB-2,and p53 were evaluated in 62 of 95 cases.Categorical data were expressed as percentages and analyzed by using the X~2 test,and furthermore the odds ratio was measured.Results(1)Only one abnormality was seen on mammography in 62 patients. Combined two abnormalities on mammography were seen in 26 patients.Mammograms were normal in 7 patients.(2)Calcifications with or without other abnormality were noted in 62 cases.Of them,73% (n =45)had higher probability of malignancy calcifications and the others were intermediate concern calcifications.Clustered calcifications(36 lesions)was the most common distribution,which usually accompanied by another abnormality.And then were segmental(18 lesions)distributed pattern.As far as the shape of mass (n = 22)was concerned,the oval shaped lesion(13 cases)was the most common,and the margin of the mass appeared as ill-defined in 15 eases,microlobulated in 1,circumscribed in 4,and obscured in 2,respectively.Isodensity mass had a higher frequency in this group(12/22,55%).Other non-calcification findings included architecture distortion(7 cases),local asymmetry (15 cases),global asymmetry (5 cases),and solitary dilated duct (3 cases),and most of them accompanied with other signs. (3)For expression profile of the biological factors,significant differences were found among malignant calcification group,intermediate concern calcification group,and non-calcification group. The odds of PR positive for the lesions noted as non-calcification were 11.00 times higher (X~2 =8.571 ,P=0.003 ;95% CI, 1.998—60.572)than the lesions noted as intermediate concern calcifications,and 8.80 times higher (X~2 = 9.748,P=0.002 ;95% CI,2.024—38.253)than the lesions noted as malignant calcifications.The odds of C-erbB-2 positive for the lesions showed as malignant calcifications were 12.35 times higher (X~2=7.353, P=0.007 ;95% CI,1.447—105.443)than the lesions showed as non-calcification,and 5.74 times higher (X~2=4.977,P = 0.026;95% CI,1.110—29.645)than the lesions showed as intermediate concern calcifications.Conclusion The mammographic features of DCIS and DCIS with small invasive foci were characteristic.Mammographic findings could be a prognostic markers,which could provide a possibility for making a treatment plan.