Publications by authors named "Cousar J"

Background: As important mediators of solute transport at the blood-brain and blood-cerebrospinal fluid barriers, ATP-binding cassette (ABC) transporters (including ABCB1, ABCC1, and ABCC2), impact the bioavailability of drugs and endogenous substrates in the brain. While several ABCB1, ABCC1, and ABCC2 single nucleotide polymorphisms (SNPs) have been identified, their impact on outcome after traumatic brain injury (TBI) is unknown.

Hypothesis: ABCB1, ABCC1, and ABCC2 SNPs are associated with Glasgow Outcome Scale (GOS) score after TBI.

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We report the case of a primary nasopharyngeal interdigitating dendritic cell tumor (IDDCT). A 25-year old male presented with bilateral decreased hearing, double vision, and ataxia. Flexible nasopharyngoscopy reviewed a large mass obstructing and filling the entire nasopharynx.

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IgG4-related disease has evolved from originally being recognized as a form of pancreatitis to encompass diseases of numerous organs including the hypophysis and one reported case of dural involvement. A search of the University of Virginia, Division of Neuropathology files for 10 years identified ten cases of unexplained lymphoplasmacytic meningeal inflammation that we then evaluated using immunohistochemical stains for IgG4 and IgG. Ten control cases including sarcoidosis (4), tuberculosis (1), bacterial abscess (2), Langerhans cell histiocytosis (2), and foreign body reaction (1) were also examined.

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Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare neoplasia of interdigitating dendritic cells. Two single case reports documenting IDCS harboring t(14;18) translocation involving immunoglobulin heavy chain (IGH) and BCL2 have been reported recently; however, one of the 2 IDCS has a synchronous follicular lymphoma, the absence or presence of a follicular lymphoma in the remaining case is not mentioned. In this study, by using polymerase chain reaction and fluorescence in situ hybridization techniques, we have showed that there is neither t(14;18)/IGH-BCL2 nor IGH gene rearrangement in 4 de novo IDCS without a concurrent or known history of a B-cell lymphoma, including follicular lymphoma, indicating that BCL2 chromosomal translocation is not a general feature of de novo IDCS.

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Posttransplantation lymphoproliferative disorders (PTLD) are heterogeneous lesions with variable morphology, immunophenotype, and molecular characteristics. Multiple distinct primary lesions can occur in PTLD, rarely with both B-cell and T-cell characteristics. Lesions can involve both grafted organs and other sites; however, PTLD involving the pituitary gland has not been previously reported.

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Two of the most challenging areas in dermatopathology are lymphoproliferative disorders and melanocytic lesions. We present a case of peripheral T-cell lymphoma occurring with an intradermal melanocytic proliferation. A 63-year-old Caucasian man presented with a 12-cm edematous, erythematous to violaceous, scalp ulceration that had enlarged over six months.

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Background: In 1952, Zoon described a series of patients with dense plasma-cell infiltrates in the glans penis. Since then, similar Zoon-like lesions (ZLL) have been described on the external female genitalia and in the airways, for which over 20 designations currently exist.

Methods: Twenty-eight cases of ZLL, twenty-two cases of lichen planus, eight cases of plasmacytoma and two cases of syphilis were evaluated from the surgical pathology archive at the University of Virginia.

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Context: Classic Hodgkin lymphoma (cHL) is regarded as a clonal B-cell neoplasm. The BIOMED-2 group recently validated a set of immunoglobulin heavy chain (IGH) multiplex primers with high sensitivity in B-cell non-Hodgkin lymphomas. We postulated that after using these primers, a higher proportion of the cHLs would have detectable rearrangements without microdissection.

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Infusion of standard-dose rituximab (RTX) in chronic lymphocytic leukemia (CLL) patients promotes rapid complement activation and deposition of C3 fragments on CLL B cells. However, immediately after RTX infusions, there is substantial loss (shaving) of CD20 from circulating malignant cells. Because shaving can compromise efficacies of anticancer immunotherapeutic mAbs, we investigated whether shaving occurs in SCID mouse models.

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Objective: We present an unusual dural-based follicular lymphoma with radiological and macroscopic features similar to a meningioma. The unusual location of this tumor and its distinction from meningioma, mucosa-associated lymphoid tissue-type marginal zone B-cell lymphoma of the dura, and intraparenchymal central nervous system lymphoma, dramatically alters the patient's postoperative treatment. The case illustrates the clinical, radiological, and histological relevance of this rare entity.

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Heme oxygenase 1 (HO-1) is an enzyme important in the catabolism of heme that is induced under conditions of oxidative stress. HO-1 degradation of heme yields biliverdin, bilirubin, carbon monoxide and iron. HO-1 is thought to serve a protective antioxidant function, and upregulation of HO-1 has been demonstrated in experimental models of neurodegeneration, subarachnoid hemorrhage, cerebral ischemia and traumatic brain injury (TBI).

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We reviewed 17 cases of primary anorectal malignant melanoma. Morphologic features evaluated included junctional change, pigmentation, morphology, and mitotic rate. Immunohistochemical stains were performed for/with S-100 protein, HMB-45, MelanA, tyrosinase, vimentin, KIT, and pankeratin.

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The purpose of this study was to better define the clinical features and natural history of peripheral T-cell lymphomas (PTCL) entities included in the Revised European American lymphoma (REAL) classification. Cases of PTCL were retrieved from the records of the Department of Pathology and classified according to the REAL classification. In addition, cases of anaplastic large cell lymphoma (ALCL) were divided into classical, small cell, and primary cutaneous subtypes, and immunostaining for the anaplastic large-cell kinase (ALK) protein was performed on all cases of ALCL.

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The computer and the digital camera offer unprecedented possibilities for improving hematology education, research, and patient service. Peripheral blood smear images of exceptional quality can be acquired rapidly and conveniently from the peripheral blood smear with a modern, high-resolution digital camera and a quality microscope. Digital cameras use CCD or CMOS image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal.

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Hepatosplenic gammadelta T-cell lymphoma is a distinct entity, characterized by occurrence in young adult males with hepatosplenomegaly, B-symptoms, peripheral blood cytopenias, and no lymphadenopathy; lymphomatous infiltrates in the splenic red pulp, hepatic sinusoids, and bone marrow sinuses; T-cell receptor (TCR) gammadelta chains and a cytotoxic T-cell phenotype; isochromosome 7q; and an aggressive clinical course. In comparison, this study describes the clinicopathologic features of 14 hepatosplenic T-cell lymphomas expressing TCR alphabeta chains. They occurred in 11 women and 3 men with a median age of 36 years.

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Mantle cell lymphoma (MCL) is more aggressive when compared with other lymphomas composed of small, mature B lymphocytes. Cyclin D1 is overexpressed in MCL as a result of the translocation t(11;14)(q13;q32). Cyclin D1 immunohistochemistry in fixed, paraffin-embedded tissue contributes to the precise and reproducible diagnosis of MCL without the requirement of fresh tissue.

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Background: Histochemical staining of bone marrow biopsy samples for microorganisms may provide a presumptive diagnosis weeks before culture.

Methods: To identify predictors of histochemical positivity, we reviewed 161 bone marrow biopsies from febrile patients with human immunodeficiency virus (HIV) infection.

Results: By multivariate analysis, both hematocrit value <30% and white blood cell count <4,000/mm3 predicted biopsy positivity by culture or staining, but only anemia predicted histochemical stain positivity.

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The human myeloid cell nuclear differentiation antigen (MNDA) is a nuclear antigen known to be expressed in mature myelomonocytic cell lines. An extensive immunocytochemical evaluation of fixed tissues confirmed MNDA expression in normal maturing granulocytes and monocytes and in acute nonlymphocytic leukemias and chronic myelogenous leukemia. MNDA was not detected in normal tissue histiocytes but was found in activated macrophages and foreign body giant cells associated with inflammation.

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The cell of origin of parafollicular (monocytoid) B cell lymphoma (PBCL), splenic marginal zone lymphoma (SMZL), and hairy cell leukemia (HCL) is controversial. To better understand the relationship between these low-grade B-cell neoplasms, we analyzed the nucleotide sequences of the rearranged immunoglobulin heavy (IgH) chain variable (V) region of the clonal population of cells in five cases of PBCL, four cases of SMZL, and seven cases of HCL to determine whether these neoplasms could be differentiated by the degree of somatic mutation in the IgH V gene or by the IgH V gene family usage. DNA was extracted from diagnostic material and clonality confirmed by PCR.

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The factor(s) responsible for the reduced B cell number and increased T cell infiltrate in T-cell-rich large-B-cell lymphomas (TCRBCLs) have not been well characterized. We studied 18 TCRBCLs and 12 diffuse large-B-cell lymphomas (DLBCLs) to compare the 1) predominant T cell subpopulation(s), 2) expression of cytotoxic granule proteins (TIA-1 and granzyme B), 3) level of tumor cell apoptosis (Apoptag system, Oncor, Gaithersburg, MD), and 4) expression of Ki-67 (Mib-1) and apoptosis-related proteins (fas (CD95), bcl-2, and p53). T cells in TCRBCLs and DLBCLs were predominantly CD8+ T cells expressing alphabeta T-cell receptors and TIA-1 (16 of 18 TCRBCLs with >50% TIA-1+ small lymphocytes) but lacking granzyme B (16 of 18 TCRBCLs with <25% granzyme B+ small lymphocytes).

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Myeloma is a common and well-studied hematopoietic neoplasm with an impressive spectrum of clinical, laboratory, and histological findings. To enhance our understanding of the diversity of myeloma, including its earliest forms, the clinical and pathological findings in 145 cases of myeloma were documented and analyzed. Our analysis indicated that myeloma has at least two distinct subtypes: one presenting with bone lesions and a nodular growth pattern and the other presenting with anemia and an infiltrative growth pattern.

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Histologic features of recurrent Hodgkin's disease (HD) after conventional therapy are well known, but few studies describe HD after bone marrow transplantation (BMT). Histologic material from 63 patients who underwent BMT performed to treat recurrent nodular sclerosing HD (NSHD) between 1985 and 1994 was examined; 13 of the 63 patients had histologically proved recurrent disease after BMT. Histologic material and clinical findings from the original diagnostic biopsy specimen and pre-BMT and post-BMT specimens were available from our study population of eight patients (five male, three female; age range, 16 to 38 years; median age, 27.

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Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) has been detected in various reactive and neoplastic lymphoproliferations and in some epithelial malignancies. However, data are lacking on LMP immunoreactivity in normal and neoplastic hematopoietic cells. Therefore, the authors studied LMP staining in 29 paraffin-embedded tissues containing these cells and correlated the findings with polymerase chain reaction (PCR) analysis for a EBV-BAM HI W genome sequence in 15 of these cases.

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