Expression of WT1 in Pediatric Small Cell Tumors: Report of Two Cases with a Possible Mesothelial Origin

1999 ◽  
Vol 2 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Paul Thorner ◽  
Jeremy Squire ◽  
Natasha Plavsic ◽  
Roland Jong ◽  
Mark Greenberg ◽  
...  
Keyword(s):  
Wilms Tumor ◽  
Small Cell ◽  
Rhabdoid Tumor ◽  
Round Cell ◽  
Rt Pcr ◽  
Fetal Kidney ◽  
Chain Reaction ◽  
Mesenchymal Phenotype ◽  
Polymerase Chain ◽  
The Right

The WT1 gene is normally expressed in fetal kidney and mesothelium, and its expression has been suggested as a marker for Wilms tumor and mesothelioma. We examined WT1 expression levels by reverse-transcriptase polymerase chain reaction (RT-PCR) in 38 childhood small-cell tumors including Wilms tumor, embryonal and alveolar rhabdomyosarcoma, Ewing sarcoma, lymphoma, desmoplastic small round-cell tumor (DSRCT), synovial sarcoma, extrarenal rhabdoid tumor, and two tumors that were atypical for this group of tumors. WT1 expression was only detected in Wilms tumor, rhabdoid tumor, and in these two cases of uncertain histogenesis. Both arose in the peritoneal cavity and by immunohistochemistry were diffusely positive for vimentin, keratin, and desmin. Tonofilaments were identified by electron microscopy in one of the cases. RT-PCR failed to detect the t(11;22) translocation associated with DSRCT in either case. Our results suggest that WT1 expression is an unusual feature of childhood non-Wilms tumors and, in the right setting, it may indicate a mesothelial origin. The expression of WT1 may play a role in mesodermal cells acquiring epithelial characteristics, a concept supported by the mixed epithelial and mesenchymal phenotype of these two cases.

scholarly journals Comparison of Reverse Transcription-Polymerase Chain Reaction, Immunohistochemistry, and Fluorescence In Situ Hybridization Methodologies for Detection of Echinoderm Microtubule-Associated Proteinlike 4–Anaplastic Lymphoma Kinase Fusion–Positive Non–Small Cell Lung Carcinoma: Implications for Optimal Clinical Testing

2012 ◽  
Vol 136 (7) ◽  
pp. 796-803 ◽  
Author(s):  
Michelle L. Wallander ◽  
Katherine B. Geiersbach ◽  
Sheryl R. Tripp ◽  
Lester J. Layfield
Keyword(s):  
Polymerase Chain Reaction ◽  
Small Cell ◽  
Wild Type ◽  
Rt Pcr ◽  
Small Cell Lung ◽  
Chain Reaction ◽  
Anaplastic Lymphoma ◽  
Pcr Method ◽  
Polymerase Chain

Context.—Echinoderm microtubule–associated proteinlike 4–anaplastic lymphoma kinase (EML4-ALK) gene fusions are detected in 3% to 13% of non–small cell lung carcinomas. Accurate testing for detection of EML4-ALK fusions is essential for appropriate therapy selection. Objective.—To compare reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) methodologies for detection of EML4-ALK fusions. Design.—Forty-six pulmonary adenocarcinomas were selected with enrichment for wild-type epidermal growth factor receptor (EGFR) status (wild type, n  =  42; mutant, n  =  4). Specimens were tested by IHC (Dako; clone ALK1), FISH (Abbott Molecular; LSI ALK break apart), and RT-PCR (variants 1 and 3a/b). Results.—EML4-ALK variant 3a/b was detectable by RT-PCR, FISH, and IHC in 4% (2 of 46) of specimens. Complete agreement among FISH and IHC reviewers was obtained for variant 3a/b. No concordance existed among methodologies for the detection of EML4-ALK variant 1. The RT-PCR method detected variant 1 in 20% (9 of 46) of specimens. Agreement among FISH viewers was poor for variant 1 because only 11% (1/9) of specimens were scored as positive by all 3 viewers. The sensitivity of IHC for detection of variant 1 was also poor because only 1 of 9 samples (11%) was scored as positive. Overall, the frequency of EML4-ALK variants 1 and 3a/b was 24% (11 of 46) in adenocarcinomas enriched for wild-type EGFR status. One EML4-ALK variant 1 fusion was found to coexist with an EGFR exon 21 mutation. Conclusions.—The FISH interpretation demonstrated great variability among observers. The RT-PCR method was the most sensitive and least-subjective methodology for detection of EML4-ALK fusions.

Performance Characteristics of a Reverse Transcriptase–Polymerase Chain Reaction Assay for the Detection of Tumor-specific Fusion Transcripts from Archival Tissue

2003 ◽  
Vol 6 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Michael K. Fritsch ◽  
Julia A. Bridge ◽  
Amy E. Schuster ◽  
Elizabeth J. Perlman ◽  
Pedram Argani
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Round Cell ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Agarose Gels ◽  
Fusion Transcripts ◽  
Small Round Cell ◽  
Polymerase Chain ◽  
Formalin Fixed

Pediatric small round cell tumors still pose tremendous diagnostic problems. In difficult cases, the ability to detect tumor-specific gene fusion transcripts for several of these neoplasms, including Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET), synovial sarcoma (SS), alveolar rhabdomyosarcoma (ARMS), and desmoplastic small round cell tumor (DSRCT) using reverse transcriptase–polymerase chain reaction (RT-PCR), can be extremely helpful. Few studies to date, however, have systematically examined several different tumor types for the presence of multiple different fusion transcripts in order to determine the specificity and sensitivity of the RT-PCR method, and no study has addressed this issue for formalin-fixed material. The objectives of this study were to address the specificity, sensitivity, and practicality of such an assay applied strictly to formalin-fixed tissue blocks. Our results demonstrate that, for these tumors, the overall sensitivity for detecting each fusion transcript is similar to that reported in the literature for RT-PCR on fresh or formalin-fixed tissues. The specificity of the assay is very high, being essentially 100% for each primer pair when interpreting the results from visual inspection of agarose gels. However, when these same agarose gels were examined using Southern blotting, a small number of tumors also yielded reproducibly detectable weak signals for unexpected fusion products, in addition to a strong signal for the expected fusion product. Fluorescence in situ hybridization (FISH) studies in one such case indicated that a rearrangement that would account for the unexpected fusion was not present, while another case was equivocal. The overall specificity for each primer pair used in this assay ranged from 94 to 100%. Therefore, RT-PCR using formalin-fixed paraffin-embedded tissue sections can be used to detect chimeric transcripts as a reliable, highly sensitive, and highly specific diagnostic assay. However, we strongly suggest that the final interpretation of the results from this assay be viewed in light of the other features of the case, including clinical history, histology, and immunohistochemistry, by the diagnostic pathologist. Additional studies such as FISH may be useful in clarifying the nature of equivocal or unexpected results.

scholarly journals Varicella Zoster Virus Induced Acute Retinal Necrosis Following Acute Meningoencephalitis in a Patient with Presumed COVID-19

2020 ◽  
Author(s):  
Kiana Hassanpour ◽  
Faezeh Khorasanizadeh ◽  
Hamid Ahmadieh ◽  
Mahmood Nabavi ◽  
Narsis Daftarian ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Aqueous Humor ◽  
Acute Retinal Necrosis ◽  
Screening Tests ◽  
Fundus Photography ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
The Right

Abstract Background: To report the coincidence of acute retinal necrosis syndrome (ARN) following acute meningoencephalitis and presumed coronavirus disease 2019 (COVID-19) in an immunocompetent patient. Case presentation: A 58-year old female presented to our emergency department complaining of sudden unilateral visual loss following a recent hospitalization for a viral meningoencephalitis. Magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) analysis, polymerase chain reaction (PCR) of the aqueous humor, reverse transcriptase polymerase chain reaction (RT-PCR) of the nasopharyngeal swab specimen, chest computed tomography (CT), and fundus photography were performed for the patient. Ophthalmic examination revealed severe ocular inflammation and yellowish patches of necrotizing retinitis in the right eye compatible with the diagnosis of ARN. The result of PCR on the aqueous humor was positive for VZV. The patient received one intravitreal ganciclovir injection and 10 days intravenous ganciclovir followed by oral acyclovir. The patient underwent COVID-19 screening tests; chest CT-scan showed the features highly suggestive for COVID-19 while the RT-PCR was negative two times. Two months later, BCVA reached 20/70 in the right eye. The anterior chamber reaction and KPs resolved and the vitreous haziness significantly decreased Conclusion: A case of VZV induced ARN following acute meningoencephalitis was observed in association with presumed COVID-19. This could be an incidental finding in the pandemic era of COVID-19; however, it could also suggest that COVID-19 might trigger ARN in cases having latent herpes family viruses.

1504: Molecular Diagnosis and Staging of Prostate Cancer Using Clusterin in Real Time Reverse Transcription Polymerase Chain Reaction (RT-PCR)

2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske
Keyword(s):  
Prostate Cancer ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Molecular Diagnosis ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain

Expression of Platelet Membrane Glycoprotein V in Human Megakaryocytes and Megakaryocytic Cell Lines: A Study Using a Novel Monoclonal Antibody against GPV

1994 ◽  
Vol 72 (05) ◽  
pp. 762-769 ◽  
Author(s):  
Toshiro Takafuta ◽  
Kingo Fujirmura ◽  
Hironori Kawano ◽  
Masaaki Noda ◽  
Tetsuro Fujimoto ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Lines ◽  
Immunohistochemical Analysis ◽  
Specific Protein ◽  
Platelet Membrane ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Flow Cytometric ◽  
Polymerase Chain ◽  
Megakaryocytic Cell

SummaryGlycoprotein V (GPV) is a platelet membrane protein with a molecular weight of 82 kD, and one of the leucine rich glycoproteins (LRG). By reverse transcription-polymerase chain reaction (RT-PCR), GPV cDNA was amplified from mRNA of platelets and megakaryocytic cell lines. However, since there are few reports indicating whether GPV protein is expressed in megakaryocytes as a lineage and maturation specific protein, we studied the GPV expression at the protein level by using a novel monoclonal antibody (1D9) recognizing GPV. Flow cytometric and immunohistochemical analysis indicated that GPV was detected on the surface and in the cytoplasm of only the megakaryocytes in bone marrow aspirates. In a megakaryocytic cell line UT-7, GPV antigen increased after treatment with phorbol-12-myri-state-13-acetate (PMA). These data indicate that only megakaryocytes specifically express the GPV protein among hematopoietic cells and that the expression of GPV increases with differentiation of the megakaryocyte as GPIb-IX complex.

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