Biomedical subjects

Werner Paulus

Publications and source records attributed to Werner Paulus.

57 records · Page 4Linked to original sources

PubMed2002

Prognostic significance of amino acid transport imaging in patients with brain tumors.

OBJECTIVE: To evaluate the prognostic significance of presence, intensity, and extent of amino acid uptake in patients with suspected primary or recurrent brain tumors. METHODS: We retrospectively analyzed 181 consecutive studies of amino acid uptake using single-photon emission computed tomography and the amino acid l-[3-(123)I]iodo-alpha-methyltyrosine (IMT). In a blinded analysis, all studies were evaluated for presence, maximal uptake (IMT(max)), and extent (IMT(ext)) of focal tracer uptake. RESULTS: The most frequent tumors were 53 astrocytomas (World Health Organization Grade I-III), 41 glioblastomas, 16 metastases, 13 oligodendrogliomas (Grade II-III), and 10 medulloblastomas. The other patients exhibited various parenchymal tumors or nonneoplastic lesions. IMT uptake was present in 69% of the patients with IMT(max) ranging from 1.4 to 6.2. IMT(max) and IMT(ext) were significant predictors of survival in the whole group. When the group was divided according to primary versus recurrent tumor, only the primary tumors achieved a high level of significance (P < 0.01). When patients without any IMT uptake were excluded from the analysis, statistical significance for both IMT(max) and IMT(ext) was lost. Multiple regression analysis, including IMT(max), IMT(ext), age, and tumor grade, revealed only extent of IMT uptake as an independent predictor of prognosis. CONCLUSION: Absence of IMT uptake is a significant predictor of long-term survival in patients with suspected primary or recurrent brain tumors. Only the extent of a given lesion provided minor supplementary prognostic information as compared with histopathology and age. These findings suggest caution in relating high amino acid uptake values to poor prognosis, despite the capability of amino acid imaging to help determine the presence and extent of gliomas.

Adolescent↗

PubMed2001

Microglia promote glioma migration.

Diffuse astrocytic gliomas extensively infiltrate brain tissue and contain numerous microglial cells, but it is unknown whether these two characteristic features are pathogenetically related. We therefore studied the effects of murine microglial cells on motility of GL261 mouse glioma cells using Boyden chamber assays. In the presence of microglia, glioma cell migration occurred earlier, and after 48 h it was threefold higher as compared to incubations without microglia. This effect was mediated by substances released from microglia, because similar effects were observed by microglia-conditioned medium, and it was specific to microglia, because oligodendroglia and endothelial cells only weakly stimulated glioma cell migration. Microglia activating substances (GM-CSF, LPS) led to a further increase of motility. These data support the notion that microglia accumulation in diffuse glial tumors does not merely represent a nonspecific reaction to tissue injury, but reflects participation of these cells in supporting and promoting the invasive phenotype of astrocytoma cells.

Animals↗

PubMed2001

Neuropathology of Raine syndrome.

We present three cases of Raine syndrome occurring in siblings of consanguineous parents. Raine syndrome is characterised by generalised osteosclerosis with craniofacial anomalies and intracranial calcifications. So far, only nine cases have been reported, and no evaluation of the distribution and extent of the cerebral mineralisations, as well as their impact on the surrounding tissue, has been undertaken yet. In our cases, calcifications were unevenly distributed throughout the central nervous system, not associated with neuronal loss or dystrophic events and appeared mostly as single calcospherites within the neuropil with occasional confluent deposits at advanced gestational age. There was intense perifocal microgliosis around single immature calcospherites, as well as mild astrogliosis around and within the confluent lesions, in which occasional macrophages could be found. Rarely, mineralisations occurred in blood-vessel walls, mainly affecting basal ganglia. Preferential sites of calcification were parietal and occipital periventricular white matter and corpus callosum, while frontal lobes were mildly affected. The cortex, temporal lobes as well as internal capsule, brain stem, cerebellum, leptomeninges, pituitary gland and choroid plexus were devoid of mineralisations. The subcortical grey matter was moderately involved in the putamen and pallidum, mildly in the caudate nucleus and subependymal germ cell matrix and not at all in the thalamus, Ammon's horn, amygdala and substantia nigra. The distribution of mineral deposits was thus inversely correlated to regional blood circulation and capillary density, with calcifications being concentrated in more sparsely perfused areas but lacking in highly vascularised tissue. This inverse relationship between mineralisation and regional blood flow was reflected in the varying distribution of calcospherites in grey and white matter as well as in the white matter of different lobes.

Brain Diseases↗