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Biomedical subjects

H Kroh

Publications and source records attributed to H Kroh.

At least 37 records · Page 2Linked to original sources
PubMed1993

Glial differentiation in medulloblastoma. Case report.

A 30-year-old man suffered for a year of a typical syndrome of cerebellar tumor. At suboccipital craniectomy a soft tumor infiltrating both hemispheres and vermis, filling up part of the IV ventricle was found. After subtotal removal of the neoplasm the postoperative course was poor and the patient died 5 weeks later. Biopsy material consisted of three types of tissue: 1. large nests of carrot-shaped, hyperchromatic cells, 2. fields of "halo" cells presenting myelin basic protein (MBP) immunoreactivity and 3. fields and scattered strongly GFAP-positive cells. The histological and immunocytochemical pattern of the neoplasm indicates differentiation of the tumor into oligodendrogliomatous and astrocytomatous line being an uncommon example of dual glial differentiation capability in medulloblastoma.

Adult↗
PubMed1992

Neuropathological changes in resected temporal lobe of patients with cryptogenic epilepsy.

The study was performed on cerebral tissue resected during temporal lobectomy in 16 patients whose long-standing cryptogenic epilepsy did not submit to anticonvulsive drugs. Cases presenting definite etiological factors such as CNS trauma, infection or neoplasm were excluded. Neuropathological investigations disclosed microangiomas and focal vascular malformations in the meninges and tissue in 7 patients. Neuronal heterotopias in the white matter and of the white matter in the cortex were observed in 3 cases. Main cortical changes were: neuronal loss, chronic neuronal degeneration, perineuronal satellitosis, and GFAP-positive submeningeal gliosis, especially at the bottom of sulci, perivascular gliosis and laminar or diffuse gliosis. The changes in the hippocampus were most enhanced in the end-plate and in the sector H3 of the pyramidal layer. Astrocytic gliosis in the white matter presented distinct GFAP and S-100 immunostaining; the latter involved in some cases a wider area than the GFAP reaction. The above named changes are analysed with regard to the presumed epileptogenic factors and to the postepileptic damage.

Adolescent↗
PubMed1992

Immunoreactivity of astroglia in the hippocampus of the Mongolian gerbil during short survival following brief ischemia.

Mongolian gerbils subjected to 5-min cerebral ischemia by common carotid artery ligation were decapitated after 24, 48, 72 and 96 h of survival to investigate the immunoreactivity of astroglia in the hippocampus. The sections from formalin-fixed, paraffin-embedded brains were stained histologically and with ABC method (Hsu et al. 1981). Control animals (normal and shame-operated) presented positive GFAP immunostaining in corpus callosum, in subventricular regions, in temporal subcortical white matter, in fimbria hipocampi and perivascularly in stratum lacunosum-moleculare. Experimental animals, independently of postischemic survival time showed various individual GFAP reactivity. Differences concerning the number and localization of immunoreactive astrocytes in both cerebral hemispheres of the same animal stressed the asymmetry of the reaction. The authors did not observe any accumulation of reactive astrocytes in the area of synaptic terminals of glutaminergic fibers (mossy fibers, Schaffer's collaterals) or in the neighbourhood of CA1 and CA3 sectors. In particular, there was complete lack or only sporadic reactive astrocytes among pyramidal neurons of CA1 and among granular cells of dentate gyrus in all examined animals.

Animals↗
PubMed1992

Anaplastic temporal lobe ganglioglioma. Case report.

Clinical, histological and histochemical features of anaplastic temporal ganglioglioma in a 30-year-old woman are described. Short clinical course (preoperative 2 years, postoperative 6 months), anaplastic features of glial astrocytic component with scarce GFAP and negative vimentin immunostaining indicate aggressive character of the tumor. Ganglionic component is confirmed by the strong Con A affinity and discrete FN and NSE immunostaining.

Adult↗
PubMed1991

Experimental CNS tumors in rats. Testing field for a computerized classification and tumor grading.

The purpose of this study was to verify the efficiency of a previously described method for the computerized histological diagnosis of experimental brain tumors (Kroh et al. 1988). 117 tumors (astrocytomas, glioblastomas, meningosarcomas, neurinomas, oligoastrocytomas and oligodendrogliomas), experimentally induced in rats, were studied. In every case the same 50 histological characteristics used for the elaboration of a computerized system for the diagnosis of experimental brain tumors in mice were analyzed. Our results demonstrate the efficiency of this diagnostic method for experimental brain tumors. Furthermore, the grade of malignancy of these tumors was also determined by using a previously described computer program.

Animals↗
PubMed1991

Ganglion cells and their satellites in experimental trigeminal schwannomas in the rat.

Ten neurinomas of ganglion semilunare nervi trigemini induced in rats with ethylnitrosourea contained numerous neurons entrapped into solid neoplastic tissue. Ganglion cells were mostly well preserved and presented the receptors to the lectin Con A, i.e. the ability for its binding to alpha-glucose and alpha-mannose. Positive GFAP immunoreaction in neuronal satellite cells suggests that the function of satellites corresponds to that of intracerebral astrocytes and that the preservation of ganglion cells depends on their satellites.

Animals↗
PubMed1988

Computer classification of experimental brain tumors in mice.

The purpose of this study was to develop a mathematical model which would be easy to use and which could provide an objective classification of experimental brain tumors. 250 brain tumors (glioblastomas, astrocytomas, astroblastomas, oligodendrogliomas, ependymomas, fibrosarcomas and giant cell sarcomas), induced in mice, were studied. In every case the same 50 histological characteristics were analyzed. For astroblastomas, oligodendrogliomas and ependymomas the diagnosis given by the neuropathologist and that given by the computer corresponded in 100% of the cases. However, some fibrosarcomas and giant cell sarcomas were not grouped in the same diagnostic category by the computer as that assigned by the neuropathologist. Thus an overall efficiency of 94.35% was obtained. This simple and efficient system of classification allows for further statistical analyses and makes it possible to correlate the results presented by different authors, thus providing for unity in all those works concerned with experimental neurooncology.

Animals↗
PubMed1988

Vascular response in experimental spinal cord gliomas of the rat.

Reported is the immunoreactivity of tumoral and peritumoral vessels of 7 spinal cord gliomas induced in rats by means of ethylnitrosourea. Immunostaining for Factor VIII/RAg has been more strongly pronounced in endothelial cells of newly formed vessels at the tumor periphery, in comparison with tumoral vessels, and this is likely to suggest a differentiation process during extensive neovascularization of the tumor periphery. Endothelial distribution of vimentin in the peripheral vessels is more intensive than within the tumors, suggesting its relation to rapid new blood vessel formation. Immunostaining for GFAP and vimentin overlaps in astrocytes trapped within neoplasms, in astrocytes at the tumor periphery, and in the peritumoral zone.

Animals↗
PubMed1987

Periphery of ethylnitrosourea-induced spinal gliomas in rats with special reference to the vascular structure.

The histology and ultrastructure of ten spinal cord gliomas, mainly oligodendrogliomas, induced transplacentally in rat with ethylnitrosourea were studied. The characteristic feature of seven spinal tumours was distinct delineation of neoplastic tissue from the edematous surrounding zone by a ring of irregular, proliferating capillaries, among which immature capillary buds prevailed. The alterations were proliferation of endothelium with endothelial overlapping, elongation of interendothelial junctions and enhancement of pinocytotic vesicles on luminal and abluminal surfaces. The basal membranes, besides other changes, were often replaced by some floccular condensations. In the edematous zone the capillary walls were deprived of contact with glial processes. The lack of contact between astrocytic processes and vascular wall may contribute to the persistent immature state of peripheral capillaries.

Animals↗