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Biomedical subjects

W Paulus

Publications and source records attributed to W Paulus.

At least 253 records · Page 14Linked to original sources
PubMed1991

Increased levels of type VIII collagen in human brain tumours compared to normal brain tissue and non-neoplastic cerebral disorders.

The expression of type VIII collagen was examined in the normal and diseased human brain. Focal immunoreactivity was seen in histologically abnormal vessels of all four angiomas and 40 of 52 brain tumours (gliomas, meningiomas and schwannomas). An extended staining pattern, as well as a punctate distribution, was frequently observed in affected vessels. Staining was not apparent in nine normal brains and in 15 pathologic brains showing various cerebrovascular abnormalities, including Alzheimer's, Leigh's and Wernicke's diseases. Immunoblotting of glioblastomas revealed two bands at 56 kD and 67 kD which were also present at low levels in normal frontal cortex. The extracellular distribution of type VIII collagen was different from that of the other collagen types which have been described in brain and resembles patterns of expression described for certain tissues during mammalian embryogenesis (Kapoor et al., 1988). Our results provide additional evidence for the participation of type VIII collagen in some types of angiogenesis.

Adult↗
PubMed1991

Intraspinal neurothekeoma (nerve sheath myxoma). A report of two cases.

Neurothekeomas (nerve sheath myxomas) are rare benign cutaneous tumors. The authors describe two spinal intradural cases that show histologic, immunohistochemical, and electron microscopic features identical to their cutaneous counterparts. The authors' findings suggest histogenesis from Schwann's cells or undifferentiated nerve sheath precursor cells. Neurothekeomas in unusual locations should be differentiated from myxoid neurofibromas, perineuriomas, and soft tissue myxomas.

Adult↗
PubMed1991

Influence of magnetic resonance imaging on evoked potentials and nerve conduction velocities in humans.

The authors investigated the influence of a 1.0-T magnetic field of a magnetic resonance (MR) imaging device, as well as the possible effects of the changing magnetic field and the RF field, on somatosensory, visual, and auditory evoked potentials and on peripheral nerve conduction velocities. The neural potentials outside and inside the static magnetic field were recorded before and after MR imaging. The measured latencies before and after MR imaging were within the normal range for healthy volunteers. The magnetic field did not significantly alter central or peripheral conduction velocities.

Adult↗
PubMed1991

The neuropathologic basis of different clinical subgroups of Parkinson's disease.

Clinical and neuropathologic data in 45 patients with Parkinson's disease (PD) were compared. Twenty-seven patients suffered from marked akinesia and rigidity (AR-type) and 18 patients from predominant resting tremor (T-type). Dementia, depression, and psychosis occurred in 26, 18, and 18 patients, respectively. Neuronal counts were performed in defined areas of the medial and lateral substantia nigra (SNM, SNL), locus ceruleus (LC), and dorsal raphe nucleus (DRN). The AR-type (compared with the T-type) showed higher neuronal loss of LC, SNL, SNM, and more severe gliosis, extraneuronal melanin deposits, and neuroaxonal dystrophy in substantia nigra. Demented PD patients showed more intense cortical Alzheimer lesions and higher neuronal depletion in the SNM, whereas PD subjects with moderate or marked dementia differed from mildly or not demented ones only in the higher degree of cortical Alzheimer lesions. More severe neuronal cell loss of DRN was observed in PD patients with depression. Occurrence of psychosis was not associated with any pathologic feature. Our findings indicate that some major clinical features of PD are related to distinct neuropathologic lesions.

Aged↗
PubMed1991

Primary intracranial sarcomas: histopathological features of 19 cases.

Nineteen primary intracranial sarcomas out of a total of about 25,000 brain tumour biopsies are reported. Subtypes included malignant fibrous histiocytoma (6 cases), leiomyosarcoma (3), rhabdomyosarcoma (2), angiosarcoma (2), and one case each of fibrosarcoma, low-grade fibromyxoid sarcoma, malignant ectomesenchymoma, mesenchymal chondrosarcoma, differentiated chondrosarcoma and Ewing's sarcoma. Histological and immunohistochemical features corresponded to those of extracranial sarcomas. Nests of pleomorphic astrocytes mimicking glioma were detected in the five storiform-pleomorphic malignant fibrous histiocytomas. Our results indicate that intracranial sarcomas can be classified like their extracranial counterparts. The low incidence compared with earlier series is related to changes in classification and progress in histogenetic clarification.

Adult↗
PubMed1991

Selective increase of iron in substantia nigra zona compacta of parkinsonian brains.

Histochemical and biochemical determinations of total iron, iron (II), and iron (III) contents in brain regions from Parkinson's and Alzheimer's diseases have demonstrated a selective increase of total iron content in parkinsonian substantia nigra zona compacta but not in the zona reticulata. The increase of iron content is mainly in iron (III). The ratio of iron (II):iron (III) in zona compacta changes from almost 2:1 to 1:2. This change is thought to be relevant and may contribute to the selective elevation of basal lipid peroxidation in substantia nigra reported previously. Iron may be available in a free state and thus can participate in autooxidation of dopamine with the resultant generation of H2O2 and oxygen free radicals.

Aged↗
PubMed1991

Mesenchymal, non-meningothelial tumors of the central nervous system.

The spectrum of non-meningothelial mesenchymal tumors that may arise within the central nervous system is presented, based on the current classification of soft tissue tumors. Among malignant types, hemangiopericytoma, rhabdomyosarcoma, mesenchymal chondrosarcoma, and malignant fibrous histiocytoma are the most frequent ones. Rare tumor entities are mentioned. As in soft tissue sarcomas, diagnosis is mainly based on light and electron microscopy, while immunohistochemistry can improve accuracy of diagnosis.

Central Nervous System Neoplasms↗
PubMed1991

The effects of baclofen and cholinergic drugs on upbeat and downbeat nystagmus.

The GABAergic drug baclofen and the cholinergic drug physostigmine were administered to patients with upbeat and downbeat nystagmus. Baclofen (orally, 5 mg three times daily) reduced nystagmus slow phase velocity and distressing oscillopsia by 25-75% in four out of five patients (two upbeat nystagmus; two downbeat nystagmus). Physostigmine (1 mg single intravenous injection) increased nystagmus in five additional patients with downbeat (1) or positional downbeat nystagmus (4) for a duration of 15-20 minutes. The different interactions of baclofen and physostigmine on neurotransmission subserving vertical vestibulo-ocular reflex could account for these effects. The response to baclofen appears to be a GABA-B-ergic effect with augmentation of the physiological inhibitory influence of the vestibulo-cerebellum on the vestibular nuclei. Similarly baclofen has an inhibitory effect on the velocity storage mechanism. Cholinergic action may cause the increment of nystagmus by physostigmine.

Adult↗
PubMed1991

Abolition of photoparoxysmal response in progressive myoclonus epilepsy.

We have investigated the effect of piracetam on photoparoxysmal responses in 3 patients with progressive myoclonus epilepsy. With doses of up to 10 g/day, elimination of photoparoxysmal responses was achieved in all 3 patients. Corresponding to EEG improvement, the clinical performance improved slightly in 2 patients and definitely in 1 patient when piracetam was added to their medication of valproate and clonazepam. According to our data, medical treatment of myoclonus with piracetam is justified particularly in myoclonus of cortical origin.

Adolescent↗
PubMed1991

[Cluster headache and chronic paroxysmal hemicrania: current therapy].

In acute attacks of cluster headache (CH), the mainstays of treatment are inhalation of pure oxygen (due to lack of any side effects), ergotamine aerosol, and intranasal application of local anaesthetics. The following treatments have hitherto been recommended for the prevention of attacks: young patient with first manifestation-methysergide; middle aged patient with episodic or chronic CH-steroids; older patient with history of resistance to therapy-lithium. These guidelines have been superceded as a result of the demonstration of the efficacy of several other drugs which have reduced side effects. This increased variety of treatments also reduces the importance of clinical differentiation between episodic and chronic cluster headache. Today, the drugs of first choice for treatment of episodic cluster headache are steroids or calcium channel blockers like verapamil, replacing methysergide which is now drug of second choice. In chronic CH, verapamil and lithium are normally prescribed, steroids-possibly in combination with one of the other drugs-are regarded as drugs of second choice. Another possibility, used with increasing frequency, is valproate acid, and the experimental drug budipine may be a further alternative in therapy resistant patients. There is no convincing role for invasive surgical procedures, particularly in the light of the increased number of effective drugs. The treatment of choice for chronic paroxysmal hemicrania is indometacin, although individual patients may respond to salicylates, naproxene, prednisone and ergotamine.

Cluster Headache↗
PubMed1990

Influence of visual blur on object-motion detection, self-motion detection and postural balance.

We have compared the influence of visual blurring (either by use of plastic foils or by plus lenses) on detection of object-motion and self-motion, and on visual control of postural balance. Three experiments were performed--in all of which object-motion and self-motion detection latencies (response times) and postural sway (sway path) increased with increasing visual blurring. We conclude that visual blurring either by foils or by glasses affects object- and self-motion perception and postural sway in a similar way.

Attention↗
PubMed1990

Establishment and characterization of a cell line (Wa-2) derived from an extrarenal rhabdoid tumor.

A new human cell line (Wa-2) derived from an extrarenal rhabdoid tumor has been established. The cell line grows as a monolayer consisting of round- and spindle-shaped cells. Injection of cells into nude mice results in the growth of solid tumors within 2 wk of inoculation. These solid tumors have the microscopic appearance similar to that of the original tumor from which the cell line was derived. Moreover, the tumor cells have all the features of rhabdoid tumors, including the intracytoplasmatic hyaline globules, large prominent nucleoli, and inclusion bodies made up of whorls of fibrillary material. Transplanted tumor cells stain positive for vimentin, cytokeratin, actin, and desmin and negative for myoglobin and neuron-specific enolase. Karyotyping of the cell line at different passages and cells derived from the transplant tumors consistently revealed a diploid number of chromosomes with a reciprocal translocation between chromosomes 18 and 22 [t(18;22) (q21;p11.2)]. In fibroblasts derived from the patient, no translocation could be found. Culturing the cells in the presence of 1-beta-D-arabinofuranosylcytosine induces differentiation, characterized by the outgrowth of neuron-like processes and the morphological appearance of cells similar to neuroblasts. Southern blot analysis showed no amplification of the N-myc oncogene. Since no published cell line derived from rhabdoid tumors exists, this cell line should be helpful to further elucidate the biology and histological origin of the malignant rhabdoid tumor.

Animals↗
PubMed1990

Immunohistochemical demonstration of mitochondria in routinely processed tissue using a monoclonal antibody.

We report results obtained using the monoclonal antibody M-II 68, which recognizes inner mitochondrial membrane in routinely processed (formalin-fixed and paraffin-embedded) tissue by light microscopic immunohistochemistry. In ten normal brains, the range of immunoreactivity in various cell types and locations was defined. The most intense staining was observed in Purkinje cells, in neurons of cranial nerve nuclei, pons and substantia nigra, as well as in choroid plexus epithelial cells. By comparison with this control group, one case of primary mitochondrial encephalomyopathy exhibited increased staining of endothelial and vascular smooth muscle cells, choroid plexus epithelial cells, and neurons of various locations. Scattered ragged-red fibres were heavily labelled in one case of mitochondrial myopathy, while ten muscles without mitochondriopathy were left unstained. Our method is able to detect accumulations of mitochondria and increases in mitochondrial cristae density. It could prove useful for differential diagnosis of routine biopsy material and for clarification of cell types involved in mitochondrial cytopathies.

Adolescent↗
PubMed1990

Clinicopathologic correlations in epithelial choroid plexus neoplasms: a study of 52 cases.

Sixty-seven tumor specimens of epithelial choroid plexus neoplasms obtained by 60 biopsies and 7 autopsies from 52 patients were investigated. Diagnoses of the first operations were choroid plexus papilloma (PP; 32 cases), choroid plexus papilloma with histological atypies (atypical PP; 6 cases), and choroid plexus carcinoma (PC; 14 cases). Carcinoembryonic antigen was expressed by 2 of the 3 biopsies autoptically recognized as metastatic carcinomas and by 2 autopsy cases of PC, while it was absent in all biopsies of true choroid plexus tumors. Tumor cells positive for transthyretin (TTR, prealbumin), S-100 protein (S100), and glial fibrillary acidic protein (GFAP) were detected in 39, 46 and 13, respectively, of the 49 cases of true choroid plexus tumors. Fourth ventricle tumors expressed more S100 (number of positive tumor cells) than lateral ventricle tumors, PP more S100 and TTR than atypical PP/PC. Tumors from patients 20 years of age and older expressed more GFAP and TTR than tumors from younger patients. Of the 30 patients with complete follow-up 19 were alive 2 to 11 years after surgery, including 7 recurrencies. Eleven died from the tumor 4 months to 7 years after surgery. The following histopathologic features (in order of decreasing significance) were correlated with poor prognosis (recurrency or fatal outcome): less than 50% of the tumor cells heavily positive for S100, presence of mitoses, absence of TTR-positive cells, brain invasion by cell nests, absence of marked stromal edema, and presence of necrotic areas. Our results indicate that some histologic features correlate significantly with poor prognosis and that immunohistochemical results correlate with tumor localization, age, and malignancy.

Adolescent↗
PubMed1990

Localization of basic fibroblast growth factor, a mitogen and angiogenic factor, in human brain tumors.

Fibroblast growth factor (FGF) is a potent angiogenic factor and a mitogen for a variety of mesoderm- and neuroectoderm-derived cell types (e.g., fibroblasts, endothelial cells, astrocytes, oligodendrocytes). After application of a monospecific polyclonal antiserum, we localized basic FGF on frozen sections of 73 human brain tumors using immunohistochemistry. FGF was present in a variable number of tumor cells (16/16 astrocytomas, 5/5 ependymomas, 0/3 benign and 4/7 anaplastic oligodendrogliomas, 11/12 glioblastomas, 11/11 meningiomas, 6/6 neurilemmomas, 0/3 pituitary adenomas, 2/2 choroid plexus papillomas, 0/1 neurocytoma, 2/2 benign fibrous histiocytomas, 2/5 metastatic carcinomas). FGF was detected in vascular cells of 59 tumors and in fibroblasts of connective tissue stroma from all papillomas and metastases. These results tend to indicate FGF involvement in the malignant progression of gliomas due to an autocrine or paracrine action. Histopathological aspects of malignant gliomas (e.g., pseudopalisading or pathological vessels) could be related to FGF activity.

Astrocytoma↗
PubMed1990

Corticonigral degeneration with neuronal achromasia and basal neurofibrillary tangles.

A man, aged 58 years, suffered from progressive dementia, parkinsonism, and gaze paralysis for 30 months. Autopsy revealed severe degeneration of the substantia nigra, numerous swollen chromatolytic neurons within the cerebral cortex, scattered basal neurofibrillary tangles, and gliosis of the cerebral white matter and basal ganglia. Unusual globular inclusions positive for tau protein were detected within neurons of the upper cortical layers. Although the pathological findings were comparable with corticonigral degeneration with neuronal achromasia, several clinical and pathological features characteristic for progressive supranuclear palsy, progressive subcortical gliosis, and Pick's disease in this and the nine previously reported cases hampered the unequivocal nosological placement.

Basal Ganglia↗