Yrjö Collan

Hypomagnesemia due to renal disease of unknown etiology.

A young man, investigated because of tetanic convulsions and arthritic pains, was shown to have hypomagnesemia, hypermagnesuria, hypokalemia, hypercalciuria, progressive nephrocalcinosis and chondrocalcinosis. In this syndrome, renal function was normal except for the abnormal excretion of electrolytes. Renal sodium conservation was normal. Light and electron microscopic studies of renal biopsy specimens showed the presence of several abnormal tubules. Immunofluorescent staining showed deposits of immunoglobulins in the glomeruli and tubules. Magnesium therapy was started under balance study conditions and resulted in decreased calciuria and complete remission of subjective symptoms. The progression of nephrocalcinosis was halted, and there was some decrease in the intra-articular calcium deposits after two years of continuous oral magnesium therapy. The administration of spironolactone decreased urinary magnesium but did not normalize it, whereas triamterene administration was without effect in this respect. The results of the morphologic and electrolyte balance studies are discussed. The patient was found to exhibit several features which have not been described before in connection with hypomagnesemia of unknown origin.

Viral culture and electron microscopy of ganglion cells in Meniere's disease and Bell's palsy.

Specimens of Scarpas ganglion during vestibular neurectomy were obtained in 6 cases of Menieres disease and specimens of geniculate ganglion in 2 cases of total facial nerve decompression and studied by tissue culture methods for detection of possible herpes and cytomegalovirus infection. In electron microscopy inclusions in the form of interwoven yarn-like structures, coarse aggregates of chromatin and light nuclear bodies were found in several vestibular ganglion cells. No typical herpes virus virions could be demonstrated. The culture for viruses all proved finally negative. At present there is no proof that viruses are present in Scarpas or geniculate ganglions but the possibility remains that the inclusion bodies observed might be viruses inactivated inside the ganglion cells.

Selective Vitamin B12 Malabsorption with Proteinuria

Percutaneous renal biopsy was performed on 5 patients with selective vitamin B12 malabsorption of whom 3 had proteinuria. Light microscopy showed slight prominence of the mesangial areas but otherwise the findings were normal. Electron microscopy showed increased mesangial matrix, thickening of the basement membrane at the mesangial areas and dark mesangial deposits. Light flocculent subendothelial material, moon craters, membranous convoluted structures, extracellular round particles and occasional intracellular microtubular inclusions were also seen in the glomeruli. The tubular basement membrane appeared thickened around a few tubules, showing membranous vesicular debris and convoluted structures. The capsular membrane also showed vesicular debris. On immunohistochemical examination the glomerular deposits contained immunoglobulins but not complement – an argument against their immunological nature. Deposits were seen only in patients who had been on inadequate treatment for years before the biopsy. Adequate treatment after correct diagnosis decreased the amount of deposits. Proteinuria did not apparently depend on the presence of glomerular deposits.

Menière’s Disease: Morphological Findings in Eighth Nerve and Vestibular End Organs

37 patients with advanced Menières disease were operated on by translabyrinthine 8th nerve neurectomy or middle fossa vestibular neurectomy. Cochlear and vestibular nerves, epithelia of the utricular macula and ampullar crista of horizontal canal were studied. All specimens were fairly well preserved and the microscopic studies suggested that there is no general deterioration of these structures even in long-standing, advanced Menières disease, but some minor deviations from normal are present in individual cells.

Electron microscopy of Nephropathia epidemica

Electron microscopical changes in the glomeruli in 20 kidney biopsies from 18 patients, who were suffering from or had lately suffered from Nephropathia epidemica were studied. Various kinds of deposits were seen. Under the endothelial cells there were collections of light flocculent material. Small dark deposits were seen in the mesangium at the mesangial cell processes, inside the thickened basement membrane, and occasionally on the epithelial side of the membrane. Large deposits were seen around mesangial cells in the mesangium. Deposits were less numerous than in chronic immune complex diseases. The intramembranous or subepithelial deposits were associated with “moon craters”, membranous convoluted structures or membrane debris. Granular extracellular mesangial material, round extracellular particles and intraendothelial microtubular inclusions were occasionally seen. In two of our cases occasional capsular epithelial cells showed numerous myelin bodies. Typical viruses were not seen in the glomeruli. The findings are in accord with the short period of scanty immune complex deposition in the glomeruli in the clinically active phase of Nephropathia epidemica.

Artifacts in Eighth Cranial Nerve Biopsy

The occurrence of artifactual morphological changes was investigated in human eighth nerve biopsies and corresponding changes were brought about in biopsies from rats by mechanical handling before fixation. At the very site of compression by a pair of forceps the biopsy stained lighter than in its immediate surroundings. Electron microscopy showed denuded and fragmented axons among vesicular debris in the area. Further away the myelin coats were greatly thickened, often to the degree that the axonal canal could no longer be identified. The myelin lamellae showed separation and were occasionally seen in convoluted forms. Also variations in the diameters of the nerve fibres and ruptures of the meylin coats could be produced after mechanical handling.

Ultrastructure of the Kidney in Tourniquet Shock

Light microscopical and ultrastructural changes in the rat kidney in tourniquet shock are described. The animals were killed 2, 4, 8 and 24 h after release of tourniquets and two animals (4 and 24 h)

Neuroglial tissue in human eighth nerve specimens

One hundred eighty nerve biopsy specimens from patients with eighth nerve tumors or other vertiginous diseases requiring vestibular neurectomy were studied. In many specimens light microscopy revealed pale areas among the myelinated nerve fibers in the neurolemmal portion of the eighth nerve. Electron microscopy showed that these were ectopic areas of glial tissue consisting of bundles of numerous cytoplasmic processes of fibrous astrocytes. The abundance of filaments within each process and the occurrence of microtubuli suggest that these processes are reactive astrocytes and accordingly are present as a consequence of the reparative potential of the astroglial tissue after a neuronal lesion. The possible functional significance of the findings is discussed.

Further observations on the eighth nerve in Menire's disease

SummaryForty patients with advanced Menières disease were operated upon by vestibular or eighth nerve neurectomy. The biopsied nerve specimens were studied by light and electron microscopy. Round areas containing no or very few axons and bundles of proliferated processes of fibrous astrocytes were found in six cases. A combination of clinical and histopathologic findings suggests that some patients with symptoms identical to Menières disease might have a primary neuronal disease leading to nonspecific reparative response by fibrous astrocytes.