M. T. Giordana

GFAP, FVIII/RAg, Laminin, and fibronectin in gliosarcomas: An immunohistochemical study

SummaryGFAP, Factor VIII/RAg, laminin, and fibronectin were immunohistochemically investigated in 15 glioblastomas and 15 gliosarcomas. GFAP was found variably positive in the glial areas. F VIII/RAg characterizes the endothelial cells and in gliosarcomas suggests the origin of the sarcomatous component from the endothelial proliferations. Laminin separates the two components and characterizes the inner and the outer basement membranes in the vessels. It is multiplied and thickened in endothelial proliferations, while it is often fragmented in the larger vessel wall proliferations. Our observations confirm that gliosarcoma represents the last stage of a process which starts with the endothelial hyperplasia of glioblastoma.

Immunohistochemical demonstration of vimentin in human cerebral tumors

SummaryThe distribution of vimentin (VIM) has been histochemically investigated in 53 cerebral tumors and compared in gliomas to that of glial fibrillary acidic protein (GFAP). In gliomas VIM is less positive than GFAP, but shows the same distribution. It cannot be considered as indicating immaturity of glial tumor cells. VIM is also positive in glial processes of cerebellar pilocytic astrocytomas, in Schwann cells of neurinomas and in endothelial cells of all oncotypes. In medulloblastomas, VIM decorates reactive glia cells. A diffuse positive reaction has been observed in meningiomas. In hemangioblastomas, besides intervascular and endothelial cells, groups of polygonal cells are intensely positive for both VIM and GFAP. The interpretatiên of VIM in cerebral tumors is largely based on the distribution patterns of this intermediate filament in the developing CNS of rodents.

The distribution of laminin in human brain tumors: An immunohistochemical study

SummaryThe immunohistochemical distribution of laminin in 70 cases of primary and secondary brain tumors has been studied. The sections were fixed in Carnoy, embedded in paraffin, and treated with collagenase before applying the specific immune serum. In normal neural tissue and in gliomas, the distribution of laminin overlaps with that of basement membrane, as is known from observations on ultrastructure in the literature. The overlapping was observed also in neurinomas, papillomas of the choroid plexus, ependymomas, and meningiomas. Problems arise in the interpretation of the results in the other oncotypes. In hemangiopericytomas and hemangioblastomas, laminin demonstrates a basement membrane around the vessels only; it is absent around stromal cells. In desmoplastic medulloblastomas, laminin forms a network among the tumor celis. In primary lymphomas, concentric rings of laminin are evidenced around some vessels. In discussing the results, the ultrastructural distribution of basement membranes is taken into account.

Collagenase in the immunohistochemical demonstration of laminin, fibronectin and factor VII/RAg in nervous tissue after fixation

SummaryThe effects of collagenase on the immunohistochemical demonstrability of laminin, fibronectin and Factor VIII/RAg in human nervous tissue have been studied. The influence of this, and other proteolytic enzymes such as pepsin and trypsin, has been investigated in relation to different fixatives. Collagenase gave better results with Carnoy fixed material than after formalin fixation; unlike trypsin and pepsin, it did not produce tissue digestion.

The vascular response to tumor infiltration in malignant gliomas

SummaryNeo-vascularization and endothelial hyperplasia have been shown to be very active in malignant gliomas. In this contribution the vascularization of the cortex infiltrated by malignant gliomas is morphometrically studied and the endothelial proliferations are immunohistochemically investigated and reconstructed by a three-dimensional computer-assisted procedure. Vessel density increases after tumor infiltration in some cases only. The diameter of vessels increases and so does the number of nuclei/vessel after the complete invasion of the cortex when vascular glomeruli develop. In completely infiltrated cortex with development of glomeruli and circumscribed necroses, vessel density is very low. No neoformation of vessels takes place before the complete infiltration of the cortex by the tumor. The hyperplastic formations, usually arranged parallel to the deep or outer cortical layers, take origin from the radially penetrating vessels from the meninges and their lateral branching. The hyperplasia deforms the vascular network, making it often inadequate to supply tumor cells. Immunohistochemically, the cells composing the hyperplastic structures are variably positive for factor VIII/RAg and, at a lesser extent, for α-smooth muscle actin. The poorness of the vascular network in many instances of completely infiltrated cortex is responsible for the development of circumscribed necroses.

Histological observations on the regrowth of malignant gliomas after radiotherapy and chemotherapy

SummaryThe reproliferation of glioblastomas after radiation and chemotherapy has been studied in 25 tumors by means of whole mount histological preparations. The tumors have been subdivided into four groups according to the radiation dose and the distance from the end of radiation. After 4,000 rad vessel proliferations and mitoses stop, while vessel degenerations and astrocytes with deformed nuclei appear. Six months after 6,000 rad have been delivered, repopulation phenomena are clearly evident and are mainly represented by mitoses both in parenchyma and in the vessel walls, circumscribed necroses with pseudopalisadings, proliferations of formerly degenerated vessels, etc.The brain adjacent to tumor (BAT) has a great importance since it is one of the reproliferating sites, even though it may be unrecognizable for the occurrence of radiation damages.

1-Naphthol basic dye (1-NBD). An alternative to diaminobenzidine (DAB) in immunoperoxidase techniques.

SummaryThe usefulness of 1-naphthol as substrate for horseradish peroxidase (HRP) in immunohistochemistry was studied using the peroxidase-antiperoxidase (PAP) and avidin-biotin-complex (ABC) methods in the demonstration of glial fibrillary acidic protein (GFAP), vimentin, carbonic anhydrase C (CA.C), and factor VIII-related antigen (FVIII/RAg) in central nervous tissue and cerebral tumors. In the presence of ammonium carbonate, 1-naphthol is oxidized by HRP and hydrogen peroxide, producing a fine gray-violet precipitate. The oxidation product of 1-naphthol proved capable of binding a great number of basic dyes. For each stain the final reaction product had a characteristic color that was different from the spontaneous color of the dye and from the color displayed by nuclei. The final color obtained with this procedure was alcohol resistant and could be mounted in solvent-based mounting media. The results obtained with the 1-nappthol basic dye (1-NBD) method were compared with those obtained using the diaminobenzidine (DAB) reaction in the demonstration of GFAP-positive astrocytes. The DAB reaction produced a more intense staining but also a coarser precipitate than the 1-NBD reaction. The 1-NBD procedure showed more morphological detail of fine structures and did not obscure nuclei and mitosis. The very low toxicity of 1-naphthol compared with DAB (a suspected carcinogen) is an important advantage of the 1-NBD method, as is its high specificity and sensitivity.

Glycosaminoglycans in human cerebral tumors: Part II. Histochemical findings and correlations

SummaryThe occurrence and the distribution of GAGs have been studied histochemically in 224 human cerebral tumors by means of Alcian blue techniques. In the normal peritumoral gray matter the alcianophilia is stronger than in the white matter and demonstrated the presence of HA and CS. In the glioma group the alcianophilia, due to HA and CS, is mainly related to the presence of infiltrated cortex. In the other tumors, GAGs are histochemically disclosed in relation to collagen, reticulin, mesodermic areas, etc. The vessels of every tumor show a positive staining for HA, CS, and HS. The histochemical findings are consistent with the biochemical ones as reported in Part I, even though the significance of GAGs in cerebral tumors remains unknown.

Ultrastructural detection of DNA-incorporated bromodeoxyuridine in resin embedded brain tissue

SummaryWe describe a protocol for the ultrastructural detection of DNA-incorporated bromodeoxyuridine (BUdR) in resin embedded tissue by means of post-embedding immunogold labeling. The paraventricular zone of rat embryos brains was dissected, fixed either in paraformaldehyde or glutaraldehyde, and embedded in LR White. BUdR gold labeling was only found when thin sections were pretreated with 4 N HCl. Other DNA denaturing agents, such as Na ethoxide, formamide, formic acid, heat or HCl at lower concentrations were ineffective. Very little difference in the degree of labeling was found depending on the fixation. This method can be applied to investigate the fine structure of replicating cells in other in vivo conditions, such as human tumors.

Glycosaminoglycans (GASs) in human cerebral tumors - Part 1. Biochemical findings

SummaryGAG electrophoretic pattern and concentration have been studied in 38 human cerebral tumors and in specimens of normal nervous tissue. Gray matter had higher total GAG concentration and higher CA to HA ratio than white matter. In both, DS was present in very small amount whereas HS represented 15% of GAGs. All benign gliomas displayed the same electrophoretic pattern and contained more GAGs than normal nervous tissue. Dermatan sulfate was detected in malignant gliomas, as well as in other oncotypes, due to their mesodermic component. Ependymomas were particularly rich in HS and meningiomas were poor in HA.