Comparison of culture method, polymerase chain reaction and serological test for the detection of Mycoplasma pneumoniae infection in children with pneumoniae / 中华微生物学和免疫学杂志

Objective To compare the capabilities of culture method, polymerase chain reaction ( PCR) and serological test in identifying Mycoplasma pneumoniae infection in children with confirmed com-munity acquired pneumonia. Methods Bronchoalveolar lavage fluid and serum samples were collected from hospitalized children with community acquired pneumonia in Capital Institute of Pediatrics from March to May in 2016. Three methods, traditional culture method, PCR and serological test, were respectively used to de-tect Mycoplasma pneumoniae infection in those children. Statistical analysis was performed by using SPSS18. 0 software and chi-square test. Results Seventy-nine children with community acquired pneumonia were enrolled in this study. Eight (10. 13%) patients were diagnosed with Mycoplasma pneumoniae infec-tions by the traditional culture method with an average positive culture period of 21 days. Twenty-three (29. 11%) patients showed positive results by using PCR analysis, including the 8 patients identified by the culture method. Forty-one (51. 90%) patients were found to be positive for Mycoplasma pneumoniae infec-tions by the serological test. However, four negative samples identified by the serological test were confirmed to be positive by PCR analysis, including two positive samples confirmed by the culture method. Statistical analysis showed that the differences in positive rates detected by using the three methods were statistically significant. Conclusion It is recommended that both serological test and PCR analysis should be used in combination with clinical symptoms for a comprehensive assessment of Mycoplasma pneumonia infection in children.

Detection of SPM and IMP metallo-β-lactamases in clinical specimens of Pseudomonas aeruginosa from a Brazilian public tertiary hospital

Phenotypic and genotypic SPM and IMP metallo-β-lactamases (MBL) detection and also the determination of minimal inhibitory concentrations (MIC) to imipenem, meropenem and ceftazidime were evaluated in 47 multidrug-resistant Pseudomonas aeruginosa isolates from clinical specimens. Polymerase chain reaction detected 14 positive samples to either blaSPM or blaIMP genes, while the best phenotypic assay (ceftazidime substrate and mercaptopropionic acid inhibitor) detected 13 of these samples. Imipenem, meropenem and ceftazidime MICs were higher for MBL positive compared to MBL negative isolates. We describe here the SPM and IMP MBL findings in clinical specimens of P. aeruginosa from the University Hospital of Botucatu Medical School, São Paulo, Brazil, that reinforce local studies showing the high spreading of blaSPM and blaIMP genes among brazilian clinical isolates.

Expression patterns of bcr-abl measured by real-time quantitative PCR in patients with chronic myeloid leukemia during treatment with imatinib mesylate / 白血病·淋巴瘤

Objective To monitor the expression patterns of bcr-abl in chronic myeloid leukemia (CML) patients during treatment with imatinib mesylate and evaluate the detection of MRD by RQ-PCR method. Methods The ABI Prism 7500 Sequence Detection System using Taqman fluorogenic probes was used to quantify target gene. bcr-abl mRNA was detected by RQ-PCR in 106 CML patients. The normalized quotient (NQ) of bcr-abl mRNA was calculated as followings: NQ=bcr-abl mRNA copy numbers/abl mRNA copy numbers. Results The NQ of BCR-ABL mRNA was well correlated with the progression of disease and the number of Ph+ cell (r =0.9824 and 0.9346, respectively). The NQ was decreased rapidly in 62 patients and kept in low level for a long time, and only 2 of them were relapsed. For 8 patients, after treatment the NQwere decreased initially and increased sharply, 7 of them were relapsed after 5-9 months. After treatment the NQ of 31 patients were still>0.1, 11 patients were relapsed after a short remission and 7 were ineffective or progression. Out of 5 patients whose NQ were fluctuated and had little regularity, but all of them had a continuing remission. Conclusion RQ-PCR is a more sensitive technique in the detection of bcr-abl fusion gene.It is an important method to monitor the tumor cell during the treatment with imatinib mesylate in CML patients.

Significance of CCL20 expression in liver biopsies of chronic hepatitis B patients / 中华检验医学杂志

Objective To observe the correlation of histologicalactivity(HAI) of chronic hepatitis B (CHB) with CCL20 expression, and to investigate the impact of CCL20 expression in CHB infection. Methods On the basis of established competitive quantitative RT-PCR with an internal standard, the expression of the CCL20 in the hepatocytes in different infected patterns of HBV infected cells and liver biopsies were quantified and at the same time its correlation to HAI were explored. Results In the cell levels, the expression quantity of CCL20 in control cells (HepG2), persistent HBV infected hepatocytes( HepG2. 2. 15) are (2. 65 ± 0. 02) pg/106 cells, ( 1.22± 0. 04) pg/106 cells, respectively. There were significantly differences between them ( t = 39. 66, P < 0. 01 ). The expression of CCL20 was enhanced in hepatocytes stimulated by PMA but their expression pauern was not changed. Moreover, CCL20 expression in liver biopsies with CHB was (3.54 ± 0. 65 ) pg/20 mg and CCL20 expression in control groups was ( 8. 74±0. 56) pg/20 mg. The expression of CCL20 between two groups was different (t =30. 09,P <0. 01 ) and correlation lied in between HAI and CCL20 expression in liver biopsies of CHB patients ( r = 0. 675, P =0. 023 ). Conclusion CCL20 expression was down-regulated and it was correlated to HAI of liver biopsies in CHB patients.

Studies on Detection of Human Immunodeficiency Virus Using Double Polymerase Chain Reaction / 대한비뇨기과학회지

BACKGROUND: Serological methods for screening blood and blood products for the presence of antibodies to human immunodeficiency virus( HIV) are efficient and sensitive. In repeatedly reactive cases confirmational tests such as Western blot are available. However, direct viral detection may be needed for a patient in seronegative window period and a newborn from a infected mother. In addition, a direct assay for the virus would provide a means to monitor both latent and actively replicating virus in patients on therapeutic drugs. However, direct detection of HIV in patient samples is difficult and disappointing even with co-cultivation and the successful recovery rate varies from 10 to 75%. Polymerase chain reaction (PCR) may provide the answer because it can do in vitro amplification of viral genome integrated into human genome (provirus). However, actual results of clinical application of conventional PCR do not show favorable sensitivity especially in samples containing very small amounts of HIV molecule copies. PURPOSE: We comparatively analyzed the sensitivity of single ( primary)PCR and double ( secondary) PCR in the detection of HIV to define whether double PCR can overcome the limited sensitivity of single( primary) PCR and if it can be a clinically promising method for detecting HIV. MATERIALS AND METHODS: Ten peripheral blood samples from individuals who had antibodies to human immunodeficiency virus were prepared and centrifuged in Ficoll-Hypaque to isolate lymphocytes and monocytes. After DNA extraction from the cell, 35 cycles of primary PCR was performed and a part of the PCR product of individual specimen was electrophoresed to elucidate the results of primary PCR. Secondary PCR with the other part of the individual primary PCR product was followed to compare the efficacies of single and double PCR. RESULTS: With primary PCR, only one specimen among 10 showed a suspicious corresponding band on polyacrylamide gel electrophoresis using ethidium bromide. The results of double PCR presented a striking contrast to those of primary PCR, elucidating 100O% sensitivity without using radioisotope. CONCLUSIONS: This study suggeststhat double PCR is a very potent method in detection of human immunodeficiency virus genome incorporated in human white blood cells.

A study on antigen receptor gene rearrangements in 13 cases of T-cell non-Hodgkin's lymphoma / 第三军医大学学报

The beta and gamma chain gene rearrangements of the T-cell receptors(TCR)were studied with Southern blot hybridization and polymerase chain reaction in 13 cases of non-Hodgkin's lymphoma with T-cell phenotype.It was found that 11 out of the 13 cases(86%)exhibited TCR beta gene rearragnement and 12 out of the 13(91%)displayed TCR gamma gene rearrangement.The findings suggest that gene rearrangements are more sensitive and specific markers to establish T-cell monoclonality and lineage and helpful to the morphological diagnosis and immunophenotyping for non-Hodgkin's lymphoma.