[A rare cause of peranal hemorrhage. Freiburg Gastroenterology Discussion].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
B Volk
Publications and source records attributed to B Volk.
CT and MRI: prognostic tools in patients with AIDS and neurological deficits.
To determine the prognostic value of CT and MRI in AIDS we studied the survival of patients with neurological involvement, in relation to the initial imaging results. Twenty-six initial CT and 15 MRI examinations of 41 patients were reviewed for the presence of cerebral atrophy and/or focal lesions. The mean survival time of patients with initially normal imaging was longer (700 +/- 89 days) than that of patients with isolated cerebral atrophy (326 +/- 65) or isolated focal lesions (202 +/- 97). The shortest survival (78 +/- 44 days) was found in patients with both cerebral atrophy and focal lesions. The risk of death in patients with atrophy alone was 3.6 times higher, that in patients with focal lesions alone 6.4 times higher, and in patients with both changes 19.3 times higher than in patients with initially normal imaging. Cerebral imaging with CT and/or MRI thus allows identification of AIDS-related cerebral changes and may contribute to assessment of prognosis.
AIDS Dementia Complex↗
Primary cerebral malignant non-Hodgkin's lymphomas: a retrospective clinical study.
In this retrospective study a series of 54 patients (seen from 1982 to 1989) with sporadic primary cerebral malignant lymphomas (PCML), which were uniformly classified with the support of immunocytochemical data, is presented. The analysis shows that on CT PCML are shown as cirumscribed, homogeneous, contrast-enhanced multifocal (70%) or solitary (30%) mass lesions within the subcortical white matter; they were found mainly close to the ventricular system or the subarachnoid space. To prove the histological diagnosis and for the purposes of differential diagnosis, low-risk CT-stereotactic biopsy is necessary and is the method of choice. Immunomorphological techniques are valuable adjuncts to confirm the histological diagnosis of PCML. In the series presented these tumours have been predominantly classified as high-grade blastic B-cell lymphomas. For this reason, this type should be regarded as the prevalent variant of malignant brain lymphomas. The evaluation of possible prognostic factors suggests that age at admission and morphological features of regression are relevant determinants of survival time. A correlation between neuroradiological evidence of a decrease in tumour size, morphological signs of regression and glucocorticoid administration has been found. Thus, patients suspected of having PCML require rapid diagnosis prior to corticosteroid administration. PCML have been shown to be radioresponsive, but not curable. Because of the lack of uniformity in management of this rate brain neoplasm, the different treatment protocols are not comparable, and hence the optimum therapy has not been satisfactorily determined.(ABSTRACT TRUNCATED AT 250 WORDS)
Actuarial Analysis↗
Central nervous system lesions in von Hippel-Lindau syndrome.
CNS manifestations were studied in 97 gene carriers of von Hippel-Lindau syndrome (HLS). Haemangioblastomas of the CNS were found in 43 patients (44%), 23 females and 20 males. The mean age at diagnosis was 39 years (12-73 years). A total of 93 haemangioblastomas were detected of which 74% were intracranial and 26% were located in the spinal cord; 75% were predominantly cystic and 25% presented as solid lesions. Multiple lesions were found in 42% of HLS-associated haemangioblastomas, but in none of 51 patients with CNS haemangioblastoma without HLS. Haemangioblastoma was the cause of death in 82% of patients with HLS. Although microsurgery has considerably improved post-operative results, multifocal tumour development and recurrence remain a serious problem in the clinical management of HLS gene carriers.
Adolescent↗
Detection of interleukin-6 and alpha 2-macroglobulin immunoreactivity in cortex and hippocampus of Alzheimer's disease patients.
We examined brains from Alzheimer's disease (AD) patients by immunohistochemistry for the presence of protease inhibitors. Immunoreactivity for alpha 2-macroglobulin (alpha 2-M), the most potent of the known human protease inhibitors, was found in a subgroup of cortical and hippocampal AD senile plaques. In addition, large hippocampal neurons in AD brains displayed intracellular alpha 2-M immunoreactivity which was consistently stronger than in normal aged brains. In cultured human cells of neurogenic origin (SH-SY5Y neuroblastoma cells), alpha 2-M synthesis could be strongly induced by the inflammatory cytokine interleukin-6 (IL-6) indicating that human alpha 2-M behaves as an acute-phase protein in the nervous system. Therefore, we also examined AD brains for the presence of IL-6 and found strong immunostaining in and around a subgroup of senile plaques as well as around large cortical neurons. Only very few senile plaques also stained for C-reactive protein, an acute phase protein known to be inducible by IL-6. We propose that the presence of IL-6 and alpha 2-M immunoreactivity in AD brains is functionally linked and that a sequence of immunological events is part of the pathology of AD.
Aged↗
A clinicopathologic and immunomorphologic study of 13 cases of ganglioglioma.
The authors present the clinical, histopathologic, and immunomorphologic data of 13 intracranial gangliogliomas. Preoperative computed tomography scans showed a commonly cystic tumor of variable density. Six tumors were completely excised and seven were subtotally resected. After a mean follow-up of 4.5 +/- 2.6 years, 11 patients are asymptomatic or only slightly incapacitated. All tumors were examined with a panel of neuronal and neuroendocrine markers. Immunoreactivity (IR) to anti-neurofilament polypeptide (clone 2F11) was observed in neuronal processes in ten cases and in neuronal perikarya in five. With anti-synaptophysin (clone SY38), IR was present along the lining of ganglion cell perikarya and processes in 11 tumors whereas staining of the perinuclear cytoplasm was prominent in two. IR to anti-chromogranin A (clone LK2H10) was observed within the neuronal perikarya in eight cases. Only one ganglioglioma of the brain stem showed IR for tyrosine-hydroxylase (clone 2/40/15) and dopamine-beta-hydroxylase in some neoplastic ganglion cells. In this study, synaptophysin was the most reliable neuronal marker. For immunocytochemical identification of neoplastic neurons in ganglioglioma as well as other tumors with neuronal differentiation the authors propose a panel of well-characterized monoclonal antibodies against neurofilament polypeptides, synaptophysin, and chromogranin A to support the histomorphologic diagnoses.
Adolescent↗
In-vitro matured human macrophages express Alzheimer's beta A4-amyloid precursor protein indicating synthesis in microglial cells.
Microglia which are consistently associated with Alzheimer's disease (AD) senile plaques are part of the mononuclear phagocyte system. In-vitro matured human monocyte-derived macrophages feature many immunological characteristics of microglia. We found strong constitutive expression of Alzheimer's beta A4-amyloid precursor protein (APP) in human mononuclear phagocytes after terminal in-vitro maturation from monocytes to macrophages. Amyloid has previously been found to be associated with microglia in AD brains, however, it remained unclear whether the material was synthesized in or had been phagocytosed by the cells. The findings presented here support the assumption that brain microglia may contribute to APP synthesis in AD brain.
Amyloid beta-Peptides↗
Alpha 2-macroglobulin synthesis in interleukin-6-stimulated human neuronal (SH-SY5Y neuroblastoma) cells. Potential significance for the processing of Alzheimer beta-amyloid precursor protein.
Cultured human neuronal (SH-SY5Y neuroblastoma) cells synthesize and secrete the potent protease inhibitor alpha 2-macroglobulin (a2M) upon stimulation with interleukin-6 (IL-6) indicating that alpha 2-macroglobulin behaves as an acute-phase protein in the human central nervous system. Exogenous addition of a2M to the cultured neuronal cells resulted in only a slight inhibition of Alzheimer beta A4-amyloid precursor protein (APP) synthesis, but markedly inhibited its secretion pointing to the possibility that a2M may affect the proteolytic APP processing. Evidence is provided that IL-6 and a2M are involved in Alzheimer's disease pathogenesis.
Alzheimer Disease↗
Gliomatosis cerebri: bioptical approach and neuropathological verification.
Gliomatosis cerebri is rarely encountered and its intra vitam diagnosis has remained difficult. We present biopsy and autopsy findings in three cases that are representative of diffuse glioma, gliomatosis cerebri and diffuse glioblastosis, a modification of the subclassification proposed by Zülch31. Stereotactic biopsy in conjunction with nuclear magnetic resonance tomography (MRT) is recommended as the diagnostic procedure in suspected cases. Immunohistochemical examination with a panel of neuroectodermal markers is helpful in the differential diagnosis but has to take into account that reactive astrocytes may be closely intermingled with the neoplastic glial cells.
Adult↗
Pancreatic lesions in the von Hippel-Lindau syndrome.
Common manifestations of the von Hippel-Lindau syndrome, an autosomally dominant inherited cancer-prone disorder, include retinal angiomatosis, hemangioblastoma of the central nervous system, renal cysts, renal cancer, pheochromocytoma, and epididymal cystadenoma. Multiple cysts and microcystic (serous) cystadenomas of the pancreas have also been reported occasionally in patients afflicted with this syndrome. In the large Freiburg study of the von Hippel-Lindau syndrome composed of 66 affected individuals, pancreatic lesions were systematically studied. Fifty-five living individuals were examined by abdominal ultrasound imaging. Abnormal findings were confirmed by computed tomographic scan and/or magnetic resonance imaging. For an additional 11 decreased patients autopsy data were available. Cystic lesions of the pancreas were found in 10 patients (15%). One of these patients presented with multiple pancreatic cysts as the only manifestation of the syndrome. In one patient, a malignant islet-cell tumor was found at autopsy. Because multiple pancreatic cysts did not cause major clinical symptoms and because follow-up examinations over an average period of 5 years did not show significant progression of the lesions, it is concluded that these patients usually do not require surgical treatment. Abdominal ultrasound screening is recommended for patients at risk as a tool to identify potential von Hippel-Lindau syndrome gene carriers with pancreatic manifestations. In all patients with multiple pancreatic cysts, the von Hippel-Lindau syndrome should be included in the differential diagnosis.
Adolescent↗
IL-6-mediated events in Alzheimer's disease pathology.
Explore the source record for details and available documents.
Alzheimer Disease↗
Mapping of phenytoin-inducible cytochrome P450 immunoreactivity in the mouse central nervous system.
The distribution of phenytoin-inducible cytochrome P450 in non-treated mouse brain and spinal cord was analysed immunohistochemically using polyclonal antibodies against phenytoin-induced mouse cerebral microsomal P450. This P450 protein was proved in Ouchterlony [Volk B. et al. (1988) Neurosci. Lett. 84, 219-224], Western blot, and immunohistochemical analyses to be reactive to the specific antibodies and an IgG fraction raised against phenobarbital-induced rat liver microsomal P450IIB1. The phenytoin-induced P450 is designated P450IIB1* because immunologically it is comparable with P450IIB1; however, it has not yet been analysed for other characteristics of this enzyme. Immunocytochemistry was performed on acetone-fixed serial cryosections of the whole brain using the avidin-biotin-peroxidase detection system. Negative controls included incubations with preimmune serum of the immunized animal instead of the primary antibody and preabsorption of the antibody with the corresponding immunogen. The pattern of immunoreactive sites indicates that P450IIB1* is not distributed evenly throughout the CNS. It was found to be restricted to only some cellular populations. The most striking aspect of immunostaining was a predominant reactivity in the evolutionary old brain parts. Neuropil and neuronal staining was found in the spinal cord (motor neurons of the ventral horn), medulla oblongata (hypoglossal nuclei, magnocellular part of the lateral reticular nuclei), pons (trigeminal, facial, cochlear and pontine nuclei), cerebellum (granule cells), midbrain (dorsal raphe nucleus) and limbic lobe (hippocampal pyramidal cells). Neuropil reactivity alone appeared in cerebellar nuclei, midbrain, thalamus, basal ganglia, neopallium and olfactory brain. Generally, pia mater/arachnoid, ependyma, choroid plexus, vascular system and some astrocytic populations were found to be strongly P450IIB1* immunoreactive. In comparison with astroglia, which is characterized by glial fibrillary acidic protein-positiveness, the astrocytes, which are also P450IIB1* reactive, occurred only in subpial and subependymal layers, and in large fiber tracts of the spinal cord and brainstem, where they were attached to the vascular system. Otherwise, the glial fibrillary acidic protein-positive astrocytes were not P450IIB1* immunoreactive in the cerebellar molecular layer (fibers of Bergmann glia), in remaining neuropils and in white matter areas.
Animals↗
[Response to comments by Feiden et al. on: Significance of stereotaxic brain biopsy in atypical multiple sclerosis].
Explore the source record for details and available documents.
Biopsy↗
Somatostatin neurotoxicity in animals.
Explore the source record for details and available documents.
Animals↗
Cerebellar injury due to phenytoin. Identification and evolution of Purkinje cell axonal swellings in deep cerebellar nuclei of mice.
The present study describes the identification and the ultrastructural and numerical evolution of Purkinje cell axonal swellings induced by phenytoin. Thirty male C57Bl/6J mice received phenytoin orally in doses up to 100 mg/kg daily and were killed after 3, 6, 10, 14, and 48 days of treatment. Light and electron microscopic investigations as well as morphometric analysis of cut surface area and numerical density of axonal swellings were performed. The swellings appeared as early as 6 days after initiation of treatment and gradually increased in size and frequency. Use of an anti-lymphocyte monoclonal antibody (CD 3), specifically cross-reacting with Purkinje cells, identified the swellings as dystrophic Purkinje cell axons. On grounds of their ultrastructural appearance they were classified into three distinct types occurring at different time intervals after phenytoin exposure. At 6 days, most axonal swellings contained loosely aggregated membranous vesicles and tubules in a finely granulated matrix (type 1). At 14 days, larger axonal swellings appeared characterized by the presence of three-dimensional networks of branched and anastomosing membranous tubules (type 2). At 48 days, even larger axons contained bodies of highly condensed membranous material of sometimes paracrystalline appearance (type 3). It is suggested that phenytoin-induced axonal pathology of Purkinje cells is a dynamic process characterized by the progressive accumulation of proliferating membranous material arranged in an increasingly complex fashion.
Animals↗
Disseminated human neurocysticercosis. A morphologic analysis of two cases.
This study was based on two cases of disseminated human neurocysticercosis from India. The material available was examined grossly, and by light microscopy, histochemistry, immunomorphology and electron microscopy. The results showed that the parasites commonly embolized to the anatomically discernable gray-white matter junction of the brain and were located in cavities, the walls of which were dilated vascular channels. The parasite-nutrition process was through endocytosis and microtrichal activity. To camouflage themselves from the host-defense mechanisms, the parasites apparently covered themselves with host-tissue-like material. Host reactivity to the parasite was heralded morphologically by the physical anchoring of the parasite by activated endothelial cells, loss of the host-tissue-like cover and an acute polymorphonuclear leucocytic response.
Brain Diseases↗
Cell loss in the cerebellum and hippocampal formation of adult rats after long-term low-protein diet.
Whereas quite a number of previous reports have shown that the developing brain is vulnerable to protein deprivation, the mature CNS is usually considered resistant to this condition. To explore this assumption the present experimental model was built on groups of 2-month-old rats fed with a low-protein diet (8% casein) for 6, 12, and 18 months and respective age-matched controls fed for the same periods with a standard laboratory chow (27% casein). The numerical density of cerebellar granule cells was estimated using three different stereological procedures (classical, unfolding, and disector). By all methods a significant cell loss was demonstrated. In the hippocampal region the numerical densities of dentate gyrus granule cells and the CA3 pyramidal cells were estimated using the unbiased disector method. A significative and progressive loss of neurons was likewise found. The occurrence of cell loss after lengthy periods of undernutrition in adulthood is thus an issue of paramount importance if extrapolation can be made to the human brain.
Animals↗
[KI-67 PAP stain for histologic grading of brain tumors by squash preparations].
Using Ki-67 monoclonal antibody to the nuclear antigen of proliferating cells, the squash preparations of 141 brain tumors and the 36 frozen sections from corresponding tumor tissues were stained with peroxidase-antiperoxidase method. The staining indices in squash preparations correlated well to those in the corresponding frozen sections. There were good correlations between the percentage of stained cells and the histologic grade in agreement with known biologic behavior. In order of decreasing malignancy, the averages of Ki-67 staining indices were 26.7% for metastatic carcinomas, 12.6% for glioblastomas, and less than 2.8% for benign mesodermal tumor groups. Ki-67 staining with squash preparations could be applied to small tissues obtained by transsphenoidal surgery and stereotactic surgery as valuable adjuncts to intraoperative histologic diagnosis and the estimation of histologic malignancy.
Adenoma↗