Jd Elema

Intracranial malignant lymphomas

SummaryFifteen primary intracranial reticulum cell sarcomas and five cases with an additional solitary extracranial tumor mass have been studied. For comparison, seven extracranial malignant non-Hodgkin lymphomas and normal lymphoid tissue were included. The methods used on formalin-fixed paraffin-embedded tissue sections were an immunoperoxidase technique for the demonstration of intracellular immunoglobulins, microglial staining, Gomoris reticulin, methylgreen-pyronin, Giemsa, diastase resistant PAS, Mallorys PTAH and H&E. Electron microscopy was performed in one primary brain tumor.According to histopathologic criteria all tumors could be classified as malignant non-Hodgkin lymphomas, predominantly of the pleomorphic immunocytic or of the immunoblastic type; follicular lymphomas were notably absent. In all cases intracellular immunoglobulins were demonstrable in tumor cells and in a majority of the tumors these were monoclonal. Thus, all malignant lymphomas proved to be of B cell origin with demonstrable cytoplasmic immunoglobulin production. Based on the microglial staining more than half of the malignant lymphomas could also be classified as microgliomas. As a comparable staining was present in non-Hodgkin lymphomas outside the CNS, microglioma characteristics are not associated with intracranial growth.

SEVERE RENAL-FAILURE FOLLOWING HIGH-DOSE IFOSFAMIDE AND MESNA

SummaryA 62-year-old woman developed subacute renal failure after the repeated administration of ifosfamide (IFX), despite its combination with continuous sodium 2-mercaptoethane sulfonate (mesna) infusion. Biopsy findings, the possible underlying mechanism, and the existing literature are discussed.

GLOMERULAR SCLEROTIC LESIONS IN THE RAT - HISTOCHEMICAL ANALYSIS OF THEIR MACROMOLECULAR AND CELLULAR COMPOSITION

SummaryThe present study provides a histochemical analysis of the macromolecular and cellular composition of focal and segmental glomerular hyalinosis and sclerosis (FSGHS) in the rat with special reference to the different types of lipids present and to the participation of monocytes. FSGHS was induced in male Wistar rats by unilateral nephrectomy (UN) or puromycin aminonucleoside (PAN) injections. Histochemical analysis of glomeruli with FSGHS in both models after 20 weeks of proteinuria revealed massive deposits of lipids. These lipid accumulations were shown to consist mainly of free and esterified cholesterol; triglycerides and phospholipids were present in small amounts. Monocytes, identified by the alpha-naphthyl acetate method for non-specific esterase activity were scanty in glomeruli affected by FSGHS with an average glomerular count of 0.1 in UN- and 0.2 in PAN-treated rats. When present, no preferential localization of monocytes in the lesions was observed. The progressive glomerular damage occurring once the process of hyalinosis and sclerosis has started may be related to the paucity of “scavenging” monocytes. Cholesterol may be one of the substances involved in the development of these glomerular changes.

Infantile histiocytosis X (letterer‐siwe disease). Investigations with enzymehistochemical and sheep‐erythrocyte rosetting techniques

Skin biopsies and a lymphnode of three children with infantile Histiocytosis‐X (Letterer‐Siwe Disease) were studied with enzymehistochemical and sheep‐erythrocyte rosetting techniques. The majority of cells making up the infiltrates of skin and lymphnode showed rather weak acid phosphatase and nonspecific esterase activity but considerable leucyl‐β‐naphtylamidase activity. Sheep‐erythrocyte rosetting techniques performed on frozen sections indicated the presence of receptors for the Fc fragment of IgG, but no receptors for C3 could be demonstrated. Cells with the same enzymehistochemical characteristics could be found in thymus‐dependent areas of normal spleen, of normal and reactive lymphnodes and in thymic medulla but not in B‐cell areas or thymic cortex. It is suggested that Histiocytosis‐X cells belong to the Mononuclear Phagocyte System and that they are related to or identical with cells normally present in the thymus dependent areas of the lymphoid tissue involved with the functioning of cell‐mediated immunity.

LOCALIZATION AND DISTRIBUTION OF ANIONIC CHARGES IN THE GLOMERULAR MESANGIUM OF NORMAL AND NEPHROTIC RATS

SummarySulfated glycosaminoglycans and sialoglycoproteins are thought to play a pivotal role in the glomerular capillary wall barrier to filtration since these anionic charged elements are important in the maintenance of capillary wall integrity and constitute a charge-selective filter. The development of proteinuria in puromycin aminonucleoside (PAN) nephrosis is associated with polyanion loss from the glomerular capillary wall structures. Since in PAN nephrosis the permeability of the mesangial area to plasma proteins and tracer substances has also been shown to be increased, the purpose of this study was to analyse the localization and distribution of anionic charges in the glomerular mesangium in this experimental model.Glycosaminoglycans were labeled by perfusion of the kidneys with ruthenium red solution (RR). Electron microscopic examination revealed the presence of distinct small RR granules (“anionic sites”) in the mesangial intercellular matrix substance and in the laminae rarae of the glomerular basement membrane (GBM). The center-to-center spacing of the granules was measured and a frequency distribution of intervals in different interval classes was constructed. In normal glomeruli the anionic sites in the mesangial matrix showed a distribution pattern identical to the GBM with a maximal interval incidence at the 31–40 nm class. In nephrotic rats anionic site distributions in matrix and GBM did not change significantly. Sialoglycoproteins were labeled with colloidal iron (CI). In PAN nephrosis a decrease of CI binding was observed at the epithelial-basement membrane junction of the glomerular capillary wall. However, CI labeling of the mesangial matrix and mesangial cell membranes did not differ from that of normal glomeruli.In conclusion, the increased mesangial permeability in PAN nephrosis appears not to be associated with significant loss or altered configuration of mesangial anionic charged moieties.

Glomerular mesangial uptake of intravenously injected colloidal carbon in the rat determined by an image analysing method: lack of influence of platelet aggregation or complement activation.

SummaryThe phagocytic capacity of the glomerular mesangium has been studied experimentally with a large number of tracers including colloidal carbon. After intravenous injection of colloidal carbon a marked platelet aggregation has been noted and factors released from the platelets may contribute to the mesangial permeability to carbon particles. Furthermore, pilot experiments revealed a systemic complement activation after intravenous injection of colloidal carbon. Circulating anaphylatoxins produced after complement activation may also influence mesangial permeability. In this paper, we have studied the mesangial uptake of intravenously injected colloidal carbon in platelet and complement depleted rats. Mesangial carbon content was assessed semiquantitatively 24 h after intravenous injection of 50 mg colloidal carbon/100 g body weight by an automatic scanning image analysing method using unstained paraffin sections. This method proved to be highly reproducible and showed a strong correlation with spectrophotometric determinations of the carbon content in isolated glomeruli.No influence of platelet aggregation or complement activation on mesangial carbon uptake was found. It is unlikely, therefore, that platelet factors or anaphylatoxins produced after complement activation are involved in the mesangial uptake of carbon under normal circumstances or in the increased mesangial carbon ingestion seen in aminonucleoside nephrosis and nephrotoxic serum nephritis. As mesangial congestion with macromolecules may result in the development of sclerosis, it is important to analyse further the factors that influence mesangial accessibility, such as the permeability of the overlying endothelium and the composition, and physical and electrochemical properties of the mesangial matrix.

The glomerular mesangium: A comparative study of mesangial handling of iron dextran complex and endogenous IgG in mice and rats

SummaryThe function and channel system of the glomerular mesangium in mice and rats was investigated by studying the uptake and transport of intravenously injected iron-dextran particles, and the localization of endogenous IgG. Animals were killed at 30 min, 8 h, 1 and 3 days and 1 and 2 weeks after intravenous injection of iron dextran complex. It was found that the tracer was present maximally in the mesangium of the mouse at one day after injection whereas a maximum was not reached until the third day in the rat. Maximal levels of tracer particles in the extra-glomerular lacis area were found at three days in the mouse and at 2 weeks in the rat. Disappearance of the tracer from the blood as indicated by the measured serum iron levels did not seem to differ significantly in the two species.Using an ultrastructural immunoperoxidase technique, considerable amounts of endogenous IgG were localized in the mesangial channel system in the stalk region and in the extraglomerular lacis area of mice, whereas in rats only very scanty endogenous IgG was present in these locations. It is suggested that the difference in mesangial handling of macromolecular material in mice and rats is more likely to be due to a different rate of transport through the mesangial channel system than to primary differences in mesangial phagocytotic activity.