摘要:

The main strategy used for the detection of circulating tumor cells (CTC) and micrometastases in solid tumors is the polymerase chain reaction (PCR) amplification of tissue specific messenger RNA present in the tumor cells. PCR was more sensitive than conventional techniques, allowing the identification of one tumor cell diluted into 1 mL of blood. PCR was shown to be specific in most studies related to the detection of CTC and marrow micrometastases in melanoma and prostate carcinoma (PC). PCR positivity for thyroid markers was reported in the blood of control subjects. Large variations in the PCR positivity rates and the prognostic value of these assays have been encountered in PC and melanoma. There was a correlation between PCR and stage in some but not all the studies. Despite these discrepancies, many investigators have shown PCR to be predictive of outcome in PC and especially in melanoma. PCR in blood and bone marrow was an independent predictor of overall and disease-free survival in melanoma patients rendered surgically free of disease. These tests may help better stratify patients for radical surgeries and adjuvant therapy. Large prospective and interlaboratory studies are needed to confirm the accuracy and prognostic value of these assays.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Diagnosis of primary cutaneous B-cell lymphoma (PCBCL) is supported by the demonstration of a monoclonal B-cell population. Immunoglobulin heavy chain (IgH) gene-rearrangement analysis by polymerase chain reaction (PCR) is a reliable technique to detect B-cell monoclonality in paraffin-embedded tissue, but the presence of numerous reactive B lymphocytes in PCBCL may complicate the interpretation of clonality test results. To test this hypothesis, IgH gene-rearrangement analysis by PCR was performed on paraffin-embedded whole tissue sections of 19 cutaneous B-cell infiltrates diagnosed either as consistent with PCBCL (10 specimens) or unclassified lymphoid infiltrates (ULI) (9 specimens). In specimens that did not show monoclonal bands by IgH gene-rearrangement on DNA extracted from whole tissue sections, clonality assays were repeated on microdissected B-cell subpopulations suspicious for neoplastic cells. In the analysis of whole tissue sections, 4 (40%) of 10 specimens consistent with PCBCL showed one or two monoclonal bands, whereas 9 of 9 ULI specimens showed either a ladder or a smear. Clonality analysis of microdissected B-cell subpopulations showed 3 additional PCBCL specimens (total, 7 of 10) and 1 ULI specimen (total, 1 of 9) with unequivocal and reproducible monoclonal bands. Addition of microdissection increases the sensitivity of PCR-based B-cell clonality assay in PCBCL compared with analysis performed on the whole section (70% versus 40% monoclonal cases) and allows the recognition of a dominant clone in ULI specimens, possibly representing early PCBCL.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Differential diagnosis between lymphomas and reactive lymphoid proliferations often requires ancillary techniques and morphologic evaluation. Flow cytometry (FCM) and polymerase chain reaction (PCR) can aid the detection of monoclonal B-cell populations. In the present study, the sensitivity and specificity of these two methods in the study of cytology specimens were compared. Eighty-six cytologic specimens from 81 patients (lymph nodes, solid organs, and body cavities) were evaluated. These specimens were taken from three groups of patients: those who underwent an initial evaluation for suspected lymphoma; those who were previously diagnosed with B-cell lymphoma and were now evaluated for possible disease recurrence; and those who were diagnosed with a nonhemato-logic malignancy. Histologic diagnosis was available for 51 samples. All samples were tested by FCM for the detection of monoclonality using kappa:lambda ratio and for clonal immunoglobulin heavy chain (IgH) gene rearrangements using a single-round PCR after cytologic evaluation. Tissue morphology, FCM and PCR results, and clinical findings in specimens without histologic diagnosis were correlated. Histologic evaluation (N = 51) revealed 44 specimens with B-cell malignancy. Twenty of the 44 lymphoma specimens (45%) were accurately diagnosed in cytologic smears, 18 (41%) were classified as suspicious of lymphoma, and 6 (14%) were diagnosed as reactive. FCM had superior sensitivity compared with PCR (77% vs. 64%). Fifty-six percent of specimens with B-cell malignancy were FCM+/PCR+, 23% were FCM+/PCR-, 14% were FCM-/PCR+, and 7% were FCM-/PCR-. The combined use of FCM and PCR resulted in a diagnosis of B-cell lymphoma in 41 (93%) of 44 B-cell lymphoma specimens and increased the sensitivity of fine needle aspiration by 48%. Both FCM and PCR aid in the diagnosis of lymphoid lesions in cytology specimens, and both can detect monoclonal B-cell populations that may be interpreted in cytology smears as reactive, even by experienced cytologists. Although FCM had higher sensitivity than PCR test in the present study, their combined use should be considered because of a relatively large number of specimens that were detected as monoclonal only with PCR.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Immunocytochemistry has indicated that, in the liver, the bcl-2 gene is generally expressed in bile duct cells and tumors of biliary origin. Both in situ hybridization and immunocytochemistry were used to analyze the expression of bcl-2 messenger RNA (mRNA) and its protein product (Bcl-2) in the tissue of 50 pure primary liver tumor (PLT) specimens including 40 hepatocellular carcinoma (HCC) specimens and 10 cholangiocellular carcinoma (CC) specimens. The phenotype of the tumors expressing bcl-2 was confirmed by immunocytochemical assessment of the cytokeratin (CK) profile (CK8, CK18, CK7, and CK19). Whereas positive immunoreaction with the anti-Bcl-2 MoAb was revealed in only 8 (20%) of 40 HCC specimens and 1 (10%) of 10 CC specimens, high contents of bcl-2 mRNA were found in 26 (65%) of 40 HCC specimens and 9 (90%) of 10 CC specimens. Regarding the CK profile, only 25 (62%) of 40 HCC specimens showed pure hepatocytic lineage (CKs 8–18), whereas among the remaining 15 HCC specimens, positivity for either CK7 (12 specimens) or CK19 (5 specimens) was observed. All 10 CC specimens stained with CKs 8–18–19, and 8 of 10 stained with CK 7 as well. These results indicate that PLTs display a greater expression of bcl-2 mRNA than of the Bcl-2 protein. Furthermore, CK profile assessment confirmed that bcl-2 expression is not confined to liver tumors of biliary origin. In the absence of a well-demonstrated post-transcriptional control of the gene, the authors propose the detection of bcl-2 mRNA by in situ hybridization as a possible alternative method for assessing the expression of bcl-2 mRNA in PLT.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the combined development of tumors in several endocrine glands and other tissues. The MEN! gene was recently identified and isolated by positional cloning. This gene was screened in two unrelated MEN1 Spanish kindreds (with four affected members and seven asymptomatic members) using single-strand conformation polymorphism, DNA sequencing, and restriction enzyme analysis. Two novel germline mutations were identified: a missense in exon 2 (H139R) and a splice-site in intron 9 (1461–2A>C). These findings allowed us to identify the MEN1 carriers among the seven asymptomatic members analyzed. An updated review of the mutations and polymorphisms found in the analysis of the MEN1 gene is provided. The report of all germline mutations causing MEN1 and easy access to this updated information are both of special diagnostic interest, because this greatly facilitates the task of attributing the disorder to a specific mutation found in a given MEN1 family. This is especially helpful in the critical differentiation of missense mutations from nonsynony-mous polymorphisms that fit the pattern of segregation of the disease, but do not cause it.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The mother and second child from a family, already with one PI ZZ child, were typed PI MZ by isoelectric focusing and unexpectedly as PI ZZ using a commercial alpha-1-antitrypsin genotyping kit. Both methods typed the father and first child as PI MZ and PI ZZ, respectively. DNA sequence analysis identified a 26-base pair (bp) deletion and 2-bp insertion in intron IV of the normal PI*M allele from both the mother and second child. The majority of the binding site for an amplification primer of the genotyping kit was absent in the variant deletion-insertion allele. The apparent PI*Z/PI*Z genotype of the mother and second child therefore arose from amplification of the PI*Z allele alone. Two hundred random DNA samples were subsequently examined and 5 of these were found to be heterozygous for the same deletion-insertion allele. The authors have designated the previously undescribed PI*M allele that harbors this benign polymorphism PI*MWhitstable. The genotyping kit has been redesigned and revalidated, and its performance is not affected by the presence of the PI*MWhitstableallele. The Gen Bank accession number for the nucleotide sequence described is AF159454.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Delay or failure in diagnostic or therapeutic management of Plasmodium falciparum malaria may result in avoidable deaths, often incurring medicolegal procedures. Advanced postmortem autolytic processes and putrefication may thwart malaria diagnosis by traditional microscopic and histologic examinations. The authors describe the usefulness of polymerase chain reaction to confirm postmortem diagnosis of malaria.

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

This study of specimens of human papillomaviruses (HPV) through HPV-specific polymerase chain reaction (PCR), followed by direct sequencing, resulted in 11% (38/354) superimposed HPV sequences, signifying coinfection with more than one HPV type. To address the diagnostic problem that these superimposed (“degenerated,” overlapping) sequences pose, the authors created a papillomavirus database in Microsoft Excel (Microsoft Corporation, Redmond, WA, U.S.A.) and Corel Quattro Pro 9 (Corel Corporation, Ottawa, Ontario, Canada) formats, retrievable fromhttp://www2.crosswinds.net/∼crosswindswatson/index.html. This sequence database is simultaneously a search and comparison tool for quick (several seconds) typing of HPV from regular and “degenerated” sequencing results. Some of the advantages of the method are as follows: (1) superimposed HPV sequences that differ in length could be readily identified from a single input; (2) the search is restricted to the currently known 127 PV types, which speeds up the typing; (3) the most common HPV sequencing artifacts are included for quick detection; (4) there is no proprietary code and the database could be easily improved; (5) HPV sequence identification does not require internet connection; and (6) new HPV types could be easily detected. This method allowed resolution of all but 1 of 354 HPV-positive specimens. From 38 superimposed HPV sequences, this method identified one known HPV type (3 specimens), two HPV types (30 specimens) and three HPV types (4 specimens).

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1052-9551    

出版商:OVID    

年代:1999

数据来源: OVID