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Biomedical subjects

E Radtke

Publications and source records attributed to E Radtke.

4 recordsLinked to original sources
PubMed2000

Helicity dependence of gammap --> Npi below 450 MeV and contribution to the Gerasimov-Drell-Hearn sum rule.

The helicity dependence of the single pion photoproduction on the proton has been measured in the energy range from 200 to 450 MeV for the first time. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a frozen-spin target. The data obtained provide new information for multipole analyses of pion photoproduction and determine the main contributions to the Gerasimov-Drell-Hearn sum rule and the forward spin polarizability gamma(0).

Journal Article↗
PubMed1998

Polysialylated neural cell adhesion molecule in childhood ganglioneuroma and neuroblastoma of different histological grade and clinical stage.

BACKGROUND AND AIMS: Neuroblastoma cells express the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), which normally becomes restricted to a few neural regions after embryogenesis. The aim of the present study was to evaluate PSA-NCAM as a marker in childhood neuroblastoma. PATIENTS/METHODS: We studied the expression of PSA-NCAM on tumor specimens and in sera of 27 children, altogether, with ganglioneuroma and neuroblastoma of different histological grades and clinical stages. For both methods, immunohistochemistry on 5-microm frozen sections and immunoluminescence serum assay, the polysialic-acid-specific monoclonal antibody 735 was used. RESULTS: PSA-NCAM expression was highest in patients with undifferentiated neuroblastoma and advanced stages of disease, whereas children with differentiated tumor types and low clinical stages had distinctly reduced or no reactivity in immunohistochemistry and, simultaneously, normal serum levels. PSA-NCAM expression correlated with other prognostic and diagnostic markers, such as MYCN gene amplification, and serum concentrations decreased during successful treatment. CONCLUSIONS: We conclude that PSA-NCAM, both immunohistochemically and in the serum, is a promising candidate for another useful diagnostic and prognostic tumor marker in childhood neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Polysialylated neural cell adhesion molecule serum levels in normal children.

Serum concentrations of polysialylated neural cell adhesion molecule (PSA-NCAM), a developmentally regulated form of the NCAM, have been recently described to be elevated in children with rhabdomyosarcoma and neuroblastoma, proving PSA-NCAM to be a tumor marker of diagnostic relevance to these malignancies. The present investigation was undertaken to define age-dependent reference intervals in normal children. Serum concentrations of polysialylated NCAM were determined in 366 children aged newborn to 17 y and in 18 adult patients by an immunoluminescence assay using the polysialic acid-specific MAb 735. Serum levels in newborn children were 51.7 kU/L (mean +/- 12.0 kU/L SD), whereas in adult patients they were 9.9 kU/L (mean +/- 3.5 kU/l SD). Assigning the patients to 14 different age groups, a gradual decay of PSA-NCAM serum concentrations was observed, and therefore, mean levels and empirical interpolated percentiles were determined for every age group. Applying specially fitted logistic functions, two different sigmoid graphs were obtained describing the age-dependent decrease of serum PSA-NCAM during the neonatal period and during childhood. The age at which the levels reach half the initial value was located at 3.1 d (mean +/- 2 d SE) and 14 y (mean +/- 1 y SE), respectively. There was no difference between male and female individuals. Repeated measurements revealed variations below 10%. For the first time, our study describes serum levels of PSA-NCAM in children of different age and their gradual decay until adulthood.

Adolescent↗