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Volker Wollscheid

Publications and source records attributed to Volker Wollscheid.

4 recordsLinked to original sources

The amyloid-beta (Abeta) peptide pattern in cerebrospinal fluid in Alzheimer's disease: evidence of a novel carboxyterminally elongated Abeta peptide.

The patterns of amyloid beta (Abeta) peptides in human cerebrospinal fluid (CSF) and brain homogenates were studied by surface-enhanced laser desorption/ionization (SELDI) time-of-flight (TOF) mass spectrometry, and the results were compared with those obtained by Abeta-SDS-PAGE/immunoblot. Apart from the peptides known in the literature to occur in the CSF, we postulate the existence of a novel, previously not described peptide, either Abeta1-45 or Abeta2-46. This peptide was observed exclusively in a pool of samples originating from patients with AD, i.e. CSF and postmortem brain homogenates, but not in either the pooled CSF samples nor the pooled brain homogenates of the non-demented controls. Similarly to our previous results, Abeta1-42 was decreased in the CSF in AD. Expectedly, brain homogenates of the control subjects did not show the presence of Abeta peptides. Compared with Abeta-SDS-PAGE/immunoblot, SELDI-TOF enabled more precise analysis of Abeta peptides in the human material. We conclude that SELDI-TOF offers a promising tool for dementia expression pattern profiling using a minute amount of a biological sample.

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Identification of a new proliferation-associated protein NET-1/C4.8 characteristic for a subset of high-grade cervical intraepithelial neoplasia and cervical carcinomas.

A large number of genes are known to be differentially expressed at distinct steps of carcinogenesis. By using a cell culture model system for cervical cancer, we had previously identified several genes that were more strongly expressed when comparing normal cervical epithelium with cervical intraepithelial neoplasia (CIN) and cervical cancer. In our study, we show that one of these genes, C4.8, is identical to NET-1, which is a new member of the tetraspanin family of proteins. By generating a mouse polyclonal antiserum against the major extracellular domain of the protein, we could detect NET-1/C4.8 expression both after ectopic expression of the gene in cell cultures and in cryostat sections of cervical biopsies. Moreover, immunohistochemic analyses of normal cervical epithelium, metaplasia, condyloma and CIN of different severity suggest that NET-1/C4.8 expression is associated with neoplastic cell proliferation. Notably, expression of the protein throughout the entire epithelium is only evident for a subset of CIN3. The potential importance for this gene in cervical carcinogenesis is underlined by an invariably strong expression in all undifferentiated squamous cell cancers examined. This indicates that this gene may be of prognostic value.

Amino Acid Sequence↗

Analysis of microdissected prostate tissue with ProteinChip arrays--a way to new insights into carcinogenesis and to diagnostic tools.

Prostate carcinomas are one of the most common malignancies in western societies. The pathogenesis of this tumor is still poorly understood. These tumors present with two characteristic features: epithelial-mesenchymal interactions, which play a pivotal role for tumor development and most of clinically manifest cancers arise in prostate proper compared to a minority of tumors which develop in the transitional zone. Deciphering the epithelial-mesenchymal cross talk and identification of molecular pecularities of the sub-populations of cells in different zones can therefore help understanding carcinogenesis and development of new, non-invasive tools for the diagnosis and prognosis of prostate carcinomas which has remained a challenge until today. A ProteinChip array technology (SELDI = surface enhanced laser desorption ionization) has been developed recently by Ciphergen Biosystems enabling analysis and profiling of complex protein mixtures from a few cells. This study describes the analysis of approximately 500-1000 freshly obtained prostate cells by SELDI-TOF-MS (surface enhanced laser desorption ionization time-of-flight mass spectrometry). Pure cell populations of stroma, epithelium and tumor cells were selected by laser assisted microdissection. Multiple specific protein patterns were reproducibly detected in the range from 1.5 to 30 kDa in 28 sub-populations of 4 tumorous prostates and 1 control. A specific 4.3 kDa peak was increased in the prostate tumor stroma compared to normal prostate proper and transitional zone stroma and increased in prostate tumor glands compared to normal prostate proper and transitional zone glands. Coupling laser assisted microdissection with SELDI provides tremendous opportunities to identify cell and tumor specific proteins to understand molecular events underlying prostate carcinoma development. It underlines the vast potential of this technology to better understand pathogenesis and identify potential candidates for new specific biomarkers in general which could help to screen for and distinguish disease entities, i.e. between clinically significant and insignificant carcinomas of the prostate.

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