Detection of Mycobacterium tuberculosis complex in paraffin-embedded tissues by real-time fluorescent quantitative polymerase chain reaction / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of real-time fluorescent quantitative (qPCR) assay in detecting mycobacterium tuberculosis complex (MTB) in paraffin embedded tissues for diagnostic purpose.</p><p><b>METHODS</b>Using qPCR assay, 1000 consecutive formalin-fixed and paraffin embedded (FFPE) tissues (from 2011 to 2012) suspected of MTB infection were tested by amplifying the MTB specific insertion sequence 6110 (IS6110). The specificity of the PCR product was confirmed by Sanger sequencing as compared with the MTB genomic DNA of the IS6110 sequence. Tissues with Ziehl-Neelsen acid-fast staining were used as control.</p><p><b>RESULTS</b>In the 1000 samples, 513 were positive for mycobacterium by Ziehl-Neelsen acid-fast staining (detection rate 51.3%); whereas 546 were MTB positive by qPCR assay (detection rate 54.6%). Concordance rate for both assays was 73.1%. The diagnosis rate increased by 14.4% by combinination of Ziehl-Neelsen acid-fast staining and qPCR results. More interestingly, by analyzing the Ziehl-Neelsen acid-fast staining and qPCR results three cases of M.leprae infection and four cases of non-tuberculous Mycobacterium (NTM) infection were identified.</p><p><b>CONCLUSIONS</b>qPCR detection of MTB in FFPE tissue is more sensitive than Ziehl-Neelsen acid-fast staining assay. Combination of these two assays can increase the detection rate and also identify some rare cases of NTM infection.</p>

The expressions of integrin alpha 3 and MMP-9 in pancreatic adenocarcinoma and their association with clinical pathological characteristics / 肿瘤

Objective: To detect the expressions of integrin alpha 3 and matrix metalloproteinase-9 (MMP-9) in pancreatic adenocarcinoma, and investigate their relationahip with clinicopathological parameters, furthermore analyze the correlation between integrin alpha 3 and MMP-9. Methods: We collected 100 cases of paraffin-embedded pancreatic adenocarcinoma tissues. The expressions of integrin alpha3 and MMP-9 were detected by immunohistochemical labelled streptavidin biotin ( LsAB) methods. Results: Ninety eight percent pancreatic adenocarcinomas were integrin alpha3-positive and 75% pancreatic adenocarcinomas highly expressed integrin alpha 3. The expressions of integrin alpha 3 in head, neck and uncinate pancreatic adenocarcinomas were stronger than those in pancreatic adenocarcinomas located at body and tail (P=0.041). Increased expression of integrin alpha3 was associated with local lymph node metastasis (P=0.012). Eighty one percent pancreatic adenocarcinomas expressed MMP-9 and 39% of them showed strongly positive. There was no correlation between the expression of MMP-9 and age, gender, tumor location, tumor grade, duodenum invasion, local lymph node metastasis, perineural invasion or TNM stage. The expression of MMP-9 positively correlated with the expression of integrin alpha 3. Conclusion: Expression of integrin alpha 3 correlates with the location of pancreatic adenocarcinomas and plays a role in local lymph node metastasis. Integrin alpha 3 might up-regulate the expression of MMP-9.