Publications by authors named "Joseph M Baron"

We reported that PIM1 kinase is expressed in the lymphocytes of patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Quercetin, a naturally occurring flavonoid, is a dietary supplement and inhibits many kinases, including PIM1, in vitro. Under an Institutional Review Board-approved protocol, we performed an open-label, single-arm pilot study to evaluate the antitumor activity of quercetin in patients with CLL/SLL.

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The human BCL6 gene, which is involved in the pathogenesis of certain human lymphomas, encodes a transcriptional repressor that is needed for germinal center B cell development and T follicular helper cell differentiation. Our goal was to identify BCL6 target genes using a cell system in which BCL6 repressive effects are inhibited followed by subtractive hybridization, and we detected the RUVBL1 (Pontin, TIP49) gene as a potential target of BCL6 repression. Here we show that the BCL6 protein significantly represses RUVBL1 transcription (6.

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The human BCL6 gene encodes a transcriptional repressor that is crucial for germinal center B cell development and T follicular helper cell differentiation. It is involved in the pathogenesis of certain human lymphomas. In an effort to identify targets of BCL6 repression, we used a previously described cell system in which BCL6 repressive effects are inhibited, followed by subtractive hybridization, and identified the integral membrane 2B gene (ITM2B, formerly BRI2) as a potential target.

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The BCL6 gene, which is expressed in certain B- and T-cell human lymphomas, is involved with chromosomal rearrangements and mutations in a number of these neoplasms. Lymphomagenesis is believed to evolve through a multi-step accumulation of genetic alterations in these tumors. We used retroviral insertional mutagenesis in transgenic mice expressing the human BCL6 transgene in order to identify genes that cooperate with BCL6 during lymphomatous transformation.

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Ammonia concentration increases in red cell units (RBCs) during storage. We measured absolute amounts of ammonia (AA) per unit serially in stored RBCs and before and after removal of the supernatant by volume reduction (VR) or washing. Ammonia increased 6.

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Diffuse large B-cell lymphomas in humans are associated with chromosomal rearrangements (∼40%) and/or mutations disrupting autoregulation (∼16%) involving the BCL6 gene. Studies of lymphoma development in humans and mouse models have indicated that lymphomagenesis evolves through the accumulation of multiple genetic alterations. Based on our prior studies, which indicated that carcinogen-induced DNA mutations enhance the incidence of lymphomas in our mouse model expressing a human BCL6 transgene, we hypothesized that mutated genes are likely to play an important cooperative role in BCL6-associated lymphoma development.

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In a patient with suspected lymphoma, it is considered desirable to confirm the diagnosis by excisional biopsy of enlarged lymph nodes. However, sometimes the ideal nodes are positioned internally, requiring a deep invasive procedure for access, or the patient may have underlying medical conditions that make it risky to perform such an invasive procedure. Under a protocol approved by our institution's review board (IRB), we reviewed five patients in whom superficial lymph nodes were biopsied which were smaller than usually considered optimal for diagnosis (=2 cm).

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Background: Patients who receive heart transplants may undergo therapeutic plasma exchange to reduce high levels of HLA antibodies which may increase the risk of allograft rejection. Plasma exchange may predispose to hypocalcemia because of chelation of calcium by sodium citrate, used as an anticoagulant both during the procedure and in thawed fresh frozen plasma often used for replacement.

Methods: We report three adults with dilated cardiomyopathy who underwent cardiac transplantation and serial plasma exchange for high levels of HLA antibodies.

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We have previously reported that the human programmed cell death-2 gene (PDCD2), a target of BCL6 repression, is likely to be important in the pathogenesis of certain human lymphomas. We now demonstrate that transfection of a construct expressing PDCD2 induces apoptosis in human cell lines, that this occurs, at least in part, through activation of the caspase cascade, and, furthermore, that caspase inhibitors block this effect. Immunohistochemical studies in human benign lymphoid and lymphoma tissues support these findings.

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We present a case of bilateral otitis externa that did not respond to local treatment. Cutaneous biopsies revealed bilateral amyloid depositions secondary to multiple myeloma. Persistent, identical bilateral canal lesions may be the only manifestation of treatable systemic disease and should be biopsied, even though their bilaterality argues against malignancy.

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Background: Bickerstaff brainstem encephalitis (BBE) is a rare inflammatory, demyelinating disease that generally has a good prognosis.

Objective: To describe the course of a patient with severe BBE and multiple medical complications.

Design: Case report.

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The human BCL6 gene on chromosome 3 band q27, which encodes a transcriptional repressor, is implicated in the pathogenesis of human lymphomas, especially the diffuse large B-cell type. We previously identified the human PDCD2 (programmed cell death-2) gene as a target of BCL6 repression. PDCD2 encodes a protein that is expressed in many human tissues, including lymphocytes, and is known to interact with corepressor complexes.

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The thrombotic thrombocytopenic purpura syndrome (TTP) can be mistaken for a number of other conditions, and it is important to diagnose correctly and treat appropriately. We describe the features of TTP that can help make a positive diagnosis and other conditions in the differential diagnosis with symptoms that can overlap and mimic those of TTR. We discuss TTP and its variants, hemolytic uremic syndrome, disseminated intravascular coagulation, heparin-induced thrombocytopenia, antiphospholipid syndrome, Evans syndrome, preeclampsia/eclampsia, HELLP syndrome, acute fatty liver of pregnancy, and multiorgan failure.

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We report the development of squamous cell carcinomas (SCCs) of the skin at or near the site of ear tags composed of a nickel-copper alloy and used for identification during the course of a long-term study of incipient congenic FVB/N mice containing the human BCL6 transgene (FVB.Cg-Tg[tetO-BCL6]Bbn Tg[EmicroSR-tTa]83Bop), their littermate controls, and wild-type FVB/N. Of a total population of 160 mice, 14 (8.

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BCL6, a gene on chromosome 3, band q27, encodes a zinc finger transcriptional repressor that is needed for germinal center formation and has been implicated in the pathogenesis of some human lymphomas when it is mutated or involved in chromosomal rearrangements. To explore further the mechanisms of action of BCL6 in lymphomagenesis, we developed a transgenic mouse model mimicking a common translocation, the t(3, 14)(q27;q32), in human lymphomas. The transgenic mice develop normally and express the transgenic BCL6 protein constitutively in lymphocytes.

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Background: Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder. The pathogenesis is believed to be mediated by an autoantibody directed against the metalloproteinase responsible for the degradation of the very-high-molecular-weight multimers of the vWF. The syndrome can be precipitated by a variety of conditions, and certain medications also have been implicated.

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Objective: The purpose of this study was to test the hypothesis that the long-term outcome of infrainguinal bypass grafting in patients with congenital or acquired hypercoagulability is inferior to the results in patients without documented clotting disorders.

Methods: The study was a retrospective analysis of consecutive patients from January 1994 to January 2001.

Results: Five hundred eighty-two infrainguinal bypass grafts were created in 456 patients.

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The association of ulcerative colitis (UC) and thrombotic thrombocytopenic purpura (TTP) is rare. Only one prior patient with these two syndromes has been reported in the literature. In that case, splenectomy and proctectomy were performed to control the symptoms of TTP.

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