Biomedical subjects

Dan-Paul Hartmann

Publications and source records attributed to Dan-Paul Hartmann.

4 recordsLinked to original sources

PubMed2006

Oligodendroglioma with neurocytic differentiation versus atypical extraventricular neurocytoma: a case report of unusual pathologic findings of a spinal cord tumor.

Differentiating oligodendroglioma from extraventricular neurocytoma by conventional light microscopy alone can present a diagnostic challenge. We report pathologic findings of an unusual spinal cord tumor from a 33-year-old male patient which showed hybrid features of oligodendroglioma and extraventricular neurocytoma. Magnetic resonance imaging (MRI) showed an enhancing intramedullary mass in the cervicothoracic region (C7 through T6). Histologic examination revealed a clear cell neoplasm containing ganglion-like cells and calcifications, prompting the differential diagnosis of oligodendroglioma and extraventricular neurocytoma. The immunohistochemical analysis disclosed neural differentiation of the neoplastic cells with strong synaptophysin and neurofilament staining consistent with extraventricular neurocytoma, as well as strong S-100 and glial fibrillary acidic protein (GFAP) expression. Molecular studies with fluorescent in situ hybridization (FISH) revealed chromosome 1p/(partial) 19q deletions, a finding commonly observed in oligodendroglioma. The proliferation index (using antibody MIB1) of the tumor was approximately 30%. The morphologic findings and these results strengthen the hypothesis that these tumors may share a common progenitor cell, which has also been observed by others. Because there are differences in patient management and long-term prognosis, it is important to attempt to distinguish between oligodendroglioma and neurocytoma. This unusual case and similar rare reported cases support the need to reclassify tumors showing pathologic features common to both neurocytoma and oligodendroglioma as a unique entity, while the effort continues to identify the cell of origin.

Adult↗

PubMed2006

Chronic idiopathic myelofibrosis terminating in extramedullary anaplastic plasmacytoma.

Chronic idiopathic myelofibrosis (CIMF) is a chronic myeloproliferative disorder (CMPD) with progressive fibrosis and extramedullary hematopoiesis. Similar to other CMPDs, the stem cell in CIMF has the potential to differentiate into myeloid or lymphoid lineages, and thus CIMF can culminate in acute leukemia of myeloid or, rarely, lymphoid lineage. We describe an unusual case of CIMF terminating in extramedullary anaplastic plasmacytoma. The patient was a 61-year-old male with an 11-year history of CIMF. His course was complicated by rapidly growing abdominal and inguinal lymphadenopathy. Lymph node biopsy revealed a diffuse undifferentiated infiltrate in the background of extramedullary hematopoiesis. Flow cytometric and immunohistochemical analysis demonstrated plasma cell-related antigens (CD138, CD38, cytoplasmic kappa light chain), epithelial membrane antigen and CD43 in the tumor cells. The myeloid, B-cell or T-cell markers were negative. A clonal immunoglobulin heavy chain gene rearrangement was identified by polymerase chain reaction. The plasma cell origin was further confirmed by electron microscopic examination, which revealed stacks of rough endoplasmic reticulum. Monoclonal gammopathy may occur in CIMF, and rare cases of simultaneous plasma cell myeloma and CIMF have been reported in the literature. However, to the best of our knowledge, this is the first report of CIMF terminating in extramedullary anaplastic plasmacytoma.

Biopsy↗

PubMed2004

Multimembrane dot-blotting: a cost-effective tool for proteome analysis.

The molecular profiles of protein expression from hundreds of cell lysates can be determined in a high-throughput manner by using fluorescent bead technologies, enzyme-linked immunosorbent assays (ELISAs), and protein microarrays. Although powerful, these tools are costly and technically challenging and thus have limited accessibility for many research groups. We propose a modification of traditional dot blotting that increases throughput of this approach and provides a simple and cost-effective technique for profiling multiple samples. In contrast to traditional blotting that uses a single membrane, we introduce blotting onto a stack of novel, thin, sieve-like membranes. These membranes have a high affinity for binding proteins, but have a lower capacity of protein binding compared to traditional (nitrocellulose) membranes. We compare the linear binding capacity and variability of these novel membranes with nitrocellulose membranes. Also, we describe the use of these membranes in a multilayer dot blot format for profiling mitogen-mediated signal transduction pathways in T cells.

Blood Proteins↗

PubMed2003

Layered expression scanning: multiplex analysis of RNA and protein gels.

Northern blots and immunoblots are utilized in laboratories worldwide and offer several important features for analyzing mRNA and protein expression, including accuracy, low cost, evaluation of probe specificity, and information on transcript and protein forms based on molecular size. However, standard blotting techniques are hampered by three factors. They require a significant amount of input material, are laborious, and are capable of measuring only one protein or transcript at a time. Here we describe a simple yet effective technique for the multiplex analysis of standard RNA and protein gels using the layered expression scanning platform. The method relies on a novel membrane with high-affinity low-capacity binding characteristics. Using this approach, multiple blots from an RNA or protein electrophoresis gel can be simultaneously produced. We believe this method will be widely applicable to expression studies for a broad range of biological systems.

Blotting, Northern↗