Publications by authors named "Stewart M Knoepp"

Lysophosphatidic acid (LPA) is a lipid mediator that binds to G-protein-coupled receptors, eliciting a wide variety of responses in mammalian cells. Lyso-phospholipids generated via phospholipase A (PLA) can be converted to LPA by a lysophospholipase D (lyso-PLD). Secreted lyso-PLDs have been studied in more detail than membrane-localized lyso-PLDs.

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Objective: The Hybrid Capture II high-risk HPV test (HC II hrHPVT) improves early detection of cervical neoplasia in Pap tests. However, weakly positive HC II results may be reported as indeterminate or "equivocal," for which there is little clinical guidance. This study is designed to evaluate the clinical outcome of equivocal HC II hrHPVTs and concurrent atypical squamous cells of undetermined significance (ASC-US) on ThinPrep Pap specimens through correlation with 2-year follow-up cervical biopsies.

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Background: Rearrangements involving the anaplastic lymphoma kinase (ALK) gene are present in approximately 5% of lung adenocarcinomas. Crizotinib is approved for the treatment of lung adenocarcinomas harboring ALK rearrangements. Patients with advanced stage lung cancer are not candidates for surgical resection of their primary tumors.

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Patients with advanced-stage melanoma harboring a BRAF mutation are candidates for BRAF inhibition as a therapeutic strategy. The use of fine-needle aspiration (FNA) to diagnose metastatic melanoma is increasing. Studies examining the predictive value of BRAF mutation analysis on melanoma FNAs via correlation with follow-up excision findings are lacking.

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The diagnosis of metastatic renal cell carcinoma (RCC) in cytology specimens may be difficult to confirm on the basis of cytomorphology alone. Often, immunohistochemistry serves as an important adjunct in confirming this diagnosis. Recently, PAX2 was shown to be useful in this regard.

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Numerous cytologic techniques aimed at effectively acquiring patient material for molecular testing have been proposed. Such techniques are becoming ever more important in an age of personalized medicine. In this commentary, the authors explored some more commonly proposed techniques to aid in the molecular testing of cytologic specimens.

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Metastatic malignancy represents a common cause of effusions. Immunocytochemistry (ICC) is useful in confirming malignancy and gaining insight into the site of origin. Cell blocks are commonly utilized for this purpose; nonetheless, when the malignant cells are sparse, they may not be represented in cell blocks thereby precluding immunophenotypic characterization.

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Background: Calcium-mediated proteolysis plays an important role in cell migration. Lysophosphatidic acid (LPA), a lipid mediator present in serum, enhances migration of carcinoma cells. The effects of LPA on calpain-mediated proteolysis were, therefore, examined in PC-3, a human prostate cancer cell line.

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Merkel cell carcinoma represents a highly aggressive cutaneous malignancy characterized by regional recurrences, lymph node metastases, distant metastases, and high mortality. As the cytomorphology of Merkel cell carcinoma can be mimicked by other malignancies, especially lymphoma and pulmonary small cell carcinoma, immunocytochemistry is often useful in confirming the diagnosis. Cell blocks, which are traditionally utilized for immunocytochemistry, occasionally exhibit insufficient cellularity.

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Familial adenomatous polyposis (FAP) is an autosomal dominant cancer predisposition syndrome that accounts for approximately 0.5-1% of all colorectal cancer cases. It is caused by germline mutations in the gene encoding the adenomatous polyposis coli (APC) tumor suppressor.

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EGFR and KRAS mutation analyses are of increasing importance for guiding the treatment of non-small cell lung carcinomas. Insufficient cellularity of cell blocks can represent an impediment to the performance of these tests. We investigated the usefulness of cytologic direct smears as an alternative specimen source for mutation testing.

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Background: The cytodiagnosis of melanoma in fine-needle aspiration (FNA) specimens can be challenging, often requiring the use of immunocytochemistry. As constitutively activating mutations in the BRAF oncogene are present in at least 40% of melanomas, the use of FNA material to interrogate the BRAF mutational status is likely to increase. Because cell blocks, traditionally used for these studies, can occasionally exhibit insufficient tumor cellularity, the authors investigated the utility of direct smears for immunocytochemistry and BRAF mutational analysis.

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We conducted a group consensus review of thyroid aspirates that were previously interpreted as "atypia of undetermined significance/follicular lesion of undetermined significance" (AUS/FLUS) and followed by surgical interventions. The study aimed to investigate if consensus review would minimize the diagnosis of AUS/FLUS with an optimal interobserver agreement and also promote a better cytohistologic concordance. A group of reviewers who were blinded to the corresponding histologic findings simultaneously evaluated a total of 50 aspirates at a multiheaded light microscope.

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The murine EL4 lymphoma cell line exists in variants that are either sensitive or resistant to phorbol 12-myristate 13-acetate (PMA). In sensitive cells, PMA causes Erk MAPK activation and Erk-mediated growth arrest. In resistant cells, PMA induces a low level of Erk activation, without growth arrest.

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The importance of subclassifying pulmonary nonsmall cell carcinoma (NSCLC) in cytologic material is becoming increasingly paramount. Occasionally, cell blocks traditionally used for ancillary studies are sparsely cellular or acellular. Hence, we investigated the diagnostic utility of immunocytochemistry for Napsin-A, TTF-1, and p63 on direct smears of NSCLC.

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Isolated extragonadal germ cell tumors can be primary in nature or metastatic from a burned out testicular cancer. Accurate diagnosis is critical as appropriate therapy can be highly curative. We present the case of an isolated extragonadal germ cell tumor in the retroperitoneum diagnosed by endoscopic ultrasound-guided fine needle aspiration.

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We used proposed standard morphologic criteria as a guideline to conduct a 10-year retrospective review of thyroid fine-needle aspiration specimens that were originally interpreted as "follicular lesion of undetermined significance" and followed by surgical intervention. We sought to investigate whether the indeterminate diagnosis could be minimized by assessing various cytomorphologic features and identifying the features predictive of neoplasia. Using the standard morphologic criteria, we semi-quantitatively assessed a total of 24 cytomorphologic features in 123 aspirates and recorded an overall interpretation on completion of the review.

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Background: The Hybrid Capture II high-risk human papillomavirus (hrHPV) DNA test is a US Food and Drug Administration-approved nucleic acid hybridization assay using chemiluminescence for the semiquantitative detection of hrHPV in cervical samples. Patient samples and controls are used to calculate results as negative for hrHPV if <1.0, positive for hrHPV if >2.

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Granulomatous inflammation is a relatively common finding in routine aspiration cytology of lymph nodes. However, asteroid bodies are very rarely encountered in cytologic preparations, and most morphologic descriptions result from observations made in histologic tissue sections. This brief report describes the cytologic findings in paratracheal aspirate smears from a 74-year-old Caucasian woman with the history of squamous-cell carcinoma of the right ankle metastatic to a right groin lymph node.

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Peritoneal washing cytology is important in the staging, prognosis, and treatment schema for women diagnosed with gynecologic malignancies. Additionally, peritoneal washings are often performed before the specific diagnosis or even the distinction between benign or malignant lesion is known. Occasionally, the cytology and surgical pathology specimens, although obtained during the same procedure, will show unexpected and/or discordant findings.

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The phosphatidylcholine-using phospholipase D (PLD) isoform PLD2 is widely expressed in mammalian cells and is activated in response to a variety of promitogenic agonists. In this study, active and inactive hemagglutinin-tagged human PLD2 (HA-PLD2) constructs were stably expressed in an EL4 cell line lacking detectable endogenous PLD1 or PLD2. The overall goal of the study was to examine the roles of PLD2 in cellular signal transduction and cell phenotype.

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Pigmented epithelioid melanocytoma (PEM) is a recently described entity comprising most cases previously described as "animal-type melanoma" and epithelioid blue nevus (EBN) occurring in patients with the multiple neoplasia syndrome Carney complex (CNC). Mutations of the protein kinase A regulatory subunit type 1alpha (R1alpha) (coded by the PRKAR1A gene) are found in more than half of CNC patients. In this study, we investigated whether PEM and EBN are related at the molecular level, and whether changes in the PRKAR1A gene status and the expression of the R1alpha protein may be involved in the pathogenesis of PEM and other melanocytic lesions.

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Introduction: The Hybrid Capture II (HC II, Digene) high-risk human papilloma virus (HPV) (hrHPV) DNA test is an in vitro nucleic acid hybridization assay that uses enhanced chemiluminescence for the qualitative and semiquantitative detection of hrHPV in cervical samples. Patient samples are concomitantly tested with positive and negative DNA controls and results reported as positive or negative on the basis of a ratio of relative light units to a cutoff value derived from the positive control (RLU/CO). Samples with a ratio <1.

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Objective: To describe the unusual finding of yellow-green-colored bone during routine orbital surgery, to detail its investigation, and to demonstrate its benign nature.

Methods: When green bone was found, specimens were sent for light and fluorescent microscopy, ultraviolet photography, and spectrophotometry.

Results: Yellow-green bone was encountered in 3 patients during orbital tumor excision or orbital fracture repair procedures.

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