Publications by authors named "David Heimann"

The coronavirus disease 2019 pandemic has impacted millions of people worldwide. This novel virus has a variety of presentations and complications. Notably, patients with this infection have an associated coagulopathy, presenting with symptoms such as gastrointestinal bleeds, deep vein thrombosis, ischemic cerebrovascular events, and pulmonary embolism.

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BACKGROUND Pheochromocytoma is a rare catecholamine-producing tumor with an estimated incidence of less than 0.1% in the global population. We present a case of cystic pheochromocytoma that was diagnosed as an incidental finding.

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Background: In the United States, approximately 2500 cases of cholangiocarcinoma occur each year. The average incidence is 1 case/100 000 persons each year. Surgical resection is the mainstay for the treatment of cholangiocarcinoma.

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Background: Extraskeletal myxoid chondrosarcoma is a unique and distinct clinicopathological entity in terms of its origin, morphology, and biologic behavior. Despite being a slow-growing tumor, it has a high rate of local recurrences and history of metastases to uncommon sites like the mandible, liver, retroperitoneum, right ventricle, pancreas, and central nervous system. Here, we report a very unique case of extraskeletal myxoid chondrosarcoma that metastasized to the breast, which itself is a very rare site for metastases.

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Background: The term carcinoid (Karzinoide) was coined by German pathologist Oberndorfer in 1907. Primary testicular carcinoid tumors (TCT) are rare, constituting 0.23% of all testicular tumors.

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Monoclonal antibodies have become increasingly used therapeutic agents for the treatment of solid cancer. Many are now being tested as components of adjuvant or first-line therapies to assess their efficacy in improving or prolonging survival. Selected unconjugated antibodies can exert clinically significant antitumor effects in many cancers.

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Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) maintains peripheral tolerance by suppressing T-cell activation and proliferation but its precise role in vivo remains unclear. We sought to elucidate the impact of CTLA-4 expression on self/tumor-reactive CD8(+) T cells by using the glycoprotein (gp) 100-specific T-cell receptor (TCR) transgenic mouse, pmel-1. pmel-1 CLTA-4(-/-) mice developed profound, accelerated autoimmune vitiligo.

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Depletion of immune elements before adoptive cell transfer (ACT) can dramatically improve the antitumor efficacy of transferred CD8+ T cells, but the specific mechanisms that contribute to this enhanced immunity remain poorly defined. Elimination of CD4+CD25+ regulatory T (T reg) cells has been proposed as a key mechanism by which lymphodepletion augments ACT-based immunotherapy. We found that even in the genetic absence of T reg cells, a nonmyeloablative regimen substantially augmented CD8+ T cell reactivity to self-tissue and tumor.

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Immunotherapy using adoptive cell transfer is a promising approach that can result in the regression of bulky, invasive cancer in some patients. However, currently available therapies remain less successful than desired. To study the mechanisms of action and possible improvements in cell-transfer therapies, we use a murine model system with analogous components to the treatment of patients.

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High-dose interleukin-2 (IL-2) results in objective clinical regression in up to 17% of patients with metastatic melanoma and renal cell carcinoma, with about half of these patients experiencing a complete regression of all lesions. Gastrointestinal (GI) perforation is a rare but potentially serious complication of IL-2 administration. A retrospective review of all patients treated with IL-2 in the Surgery Branch of the National Cancer Institute (NCI) between Nov.

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Many tumor-associated antigens are derived from nonmutated "self" proteins. T cells infiltrating tumor deposits recognize self-antigens presented by tumor cells and can be expanded in vivo with vaccination. These T cells exist in a functionally tolerant state, as they rarely result in tumor eradication.

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