Non-radioactive measurement of telomerase activity in human bladder cancer,bladder washings,and in urine

Early diagnosis is still the most important prerequisite for successful cancer treatment and this holds true for bladder cancer. Urine cytology is commonly used as a non-invasive screening procedure for the detection of bladder carcinoma, but this method is labour-intensive and often generates false-negative results. The ribonucleoprotein telomerase appears to be a promising new cancer marker, since its activity has been reported to correlate with indefinite growth. The aim of this study was to investigate whether telomerase activity can be detected in bladder cancer and in corresponding bladder washings. For this purpose, a sensitive non-radioactive TRAP (telomeric repeat amplification protocol) detection system was developed. With this technique, telomerase activity was found in 95 per cent of the carcinomas (n=20), in 70 per cent of the corresponding bladder washings, but in none of the urine samples obtained from patients with bladder carcinoma. No telomerase activity was detectable in normal urothelium or in samples from dysplastic urothelium. The data obtained from bladder washings show that superficial carcinoma cells released into the bladder still harbour telomerase activity. The absence of telomerase activity in voided urine is thus most likely due to degradation or inactivation under these conditions. The high rate of telomerase activity in bladder carcinoma indicates that the activation of telomerase is a common step in the tumourigenesis of bladder cancer. © 1998 John Wiley & Sons, Ltd.     

Genome-wide search for loss of heterozygosity in Chinese patients with sporadic colorectal cancer

In an attempt to integrally investigate the loss of tumor suppressor genes and search for putative suppressor loci associated with tumor occurrence and progression, we conducted a genome-wide loss of heterozygosity (LOH) study of 83 tumor samples obtained from Chinese patients with sporadic colorectal cancer. We employed 400 fluorescence-labeled microsatellite marker primers to amplify the corresponding loci of the genomic DNA and then electrophoresed the polymerase chain reaction products and analyzed the fluorescent signals. The LOH frequencies were high (>35%) but were not associated with the tumor stage and progression in 20 loci, including the regions where TP53, E-cadherin, deleted in colorectal carcinoma (DCC), phosphatase and tensin homolog deleted on chromosome 10 (PTEN), mothers against decapentaplegic, Drosophila, homolog of 2 (MADH2) and mothers against decapentaplegic, Drosophila, homolog of 4 (MADH4) reside. Loss of other loci, including two narrow regions on chromosome 2, was found to relate to the tumor stage, suggesting that this genomic instability may contribute to tumor progression.     

Epidemiology and genetic variability of human metapneumovirus during a 4‐year‐long study in Southeastern Brazil

Epidemiological and molecular characteristics of human metapneumovirus (hMPV) were compared with human respiratory syncytial virus (hRSV) in infants and young children admitted for acute lower respiratory tract infections in a prospective study during four consecutive years in subtropical Brazil. GeneScan polymerase chain assays (GeneScan RT‐PCR) were used to detect hMPV and hRSV in nasopharyngeal aspirates of 1,670 children during January 2003 to December 2006. hMPV and hRSV were detected, respectively, in 191 (11.4%) and in 702 (42%) of the children admitted with acute lower respiratory tract infections at the Sao Paulo University Hospital. Sequencing data of the hMPV F gene revealed that two groups of the virus, each divided into two subgroups, co‐circulated during three consecutive years. It was also shown that a clear dominance of genotype B1 occurred during the years 2004 and 2005, followed by genotype A2 during 2006. J. Med. Virol. 81:915–921, 2009. © 2009 Wiley‐Liss, Inc.     

Evaluation of T-Cell Receptor Repertoires in Patients with Long-Term Renal Allograft Survival

The mechanisms underlying long-term acceptance of kidney allografts in humans under minimal or no maintenance immunosuppression are poorly understood. We analyzed the T-cell receptor (TCR) repertoires in circulating T cells of patients with long-term (≥9 years) renal allograft survival with (LTS-IS) and without immunosuppression (LTS-NoIS). T cells of LTS patients exhibited strongly altered TCR Vß usage, including an increased frequency of oligoclonality and a decreased frequency of polyclonality. All 3 LTS-NoIS and 12 of 16 LTS-IS patients demonstrated oligoclonality in at least three or more TCR Vß families, and the frequency of oligoclonality in these patients was significantly higher as compared to patients with well-functioning grafts at 3 years (p < 0.005 both), an uncomplicated course during the first year (p < 0.0001, both), acute rejection (p < 0.0001, both), chronic allograft nephropathy at 7 (p < 0.0001, both) or 13 years (p < 0.0001, both), dialysis patients (p < 0.0001, both) or healthy controls (p < 0.0001, both). In contrast to LTS patients, all other studied patient groups exhibited a polyclonal TCR repertoire. Our data indicate that TCR alteration is a common feature of long-term allograft outcome, which might be explained by clonal deletion, exhaustion of alloreactive T cells or predominant expression of particular T-cell subpopulations, such as regulatory T cells.     

单管PCR扩增鉴定ABO血型基因型

本研究目的是建立单管PCR扩增鉴定ABO血型基因型的方法.采用盐析法抽提DNA,应用单管PCR扩增结合基因扫描技术对ABO血型的基因型进行鉴定.结果表明：用本方法鉴定出的132例样本的ABO基因型结果与其血清学结果完全符合,A、B、O基因频率分别为0.205、0.159、0.636,其中AA基因型8例（6.1%）,AO基因型31例（23.5%）,AB基因型7例（5.3%）,BB基因型6例（4.5%）,BO基因型23例（17.4%）,OO基因型57例（43.2%）.结论：单管PCR扩增结合基因扫描技术能鉴定ABO血型基因型.     

Clonal T-cell receptor γ-chain gene rearrangement by PCR-based GeneScan analysis in advanced cutaneous T-cell lymphoma: a critical evaluation

Detection of clonal T-cell receptor γ (TCRγ)-chain gene rearrangement is a promising approach to distinguish between cutaneous T-cell lymphomas (CTCLs) and reactive T-cell infiltrates. Despite the improved sensitivity by using the polymerase chain reaction (PCR) rather than Southern blot analysis, monoclonality could be demonstrated in only 53–90 per cent of CTCL biopsies in recent studies. In the present study, formalin-fixed, paraffin-embedded specimens of 21 selected patients with clear-cut advanced-stage CTCL were analysed using a semi-nested TCRγ PCR with newly developed consensus primer pairs. Detection of PCR products was done by GeneScan analysis (GSA); this technique is advantageous due to its sensitivity and accuracy in the detection and size determination of PCR products and it is easier to interpret than direct read-outs from TGGE or DGGE gels. In serial dilution experiments, TCRγ-PCR-GSA allowed the detection of clonal, rearranged T-cells with a high in vitro sensitivity against a polyclonal background (1–6 per cent). Despite the selection of clear-cut, advanced-stage CTCL cases, however, dominant clonal TCRγ-chain gene rearrangement was found in only 16 of the 21 patients analysed, indicating an overall clinical sensitivity of 76 per cent. Specificity was evaluated using biopsy specimens from 21 control patients suffering from long-standing psoriasis (n = 13) and eczema (n = 8). Surprisingly, GeneScan profiles showing apparently single dominant peaks were detected in 14 per cent of these skin lesions, but these profiles turned out to be pseudo-monoclonal by repeated determinations. In conclusion, TCRγ-PCR-GSA does not suffice reliably to exclude malignancy, due to its limited clinical sensitivity, but with precautions taken to detect pseudo-monoclonality and to secure specificity, TCRγ-PCR-GSA is a valuable instrument in the diagnosis of CTCL. Copyright © 1999 John Wiley & Sons, Ltd.     

基因扫描技术在ABO血型基因型鉴定中的应用

目的 建立基因扫描（GeneScan）技术鉴定ABO血型基因型的方法。方法根据O1基因在261位G缺失而非O1基因无缺失，B基因第803位核苷酸与A基因不同的特点，设计4对引物，分别在上游引物5’端标记荧光基团，PCR-SSP扩增后，用基因扫描技术鉴定ABO血型基因型。结果129例样本用Genescan技术鉴定的ABO血型结果与血清学结果完全符合，A、B、O基因频率分别为0．198、0．159、0．643。其中AA基因型8例（6．2％），AO基因型29例（22．5％），AB基因型6例（4．7％），BB基因型6例（4．7％），BO基因型23例（17．8％），OO基因型57例（44．2％）。结论Genescan技术鉴定ABO血型基因型具有可行性，提供了一种可选择的方法。