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Biomedical subjects

J Lähdevirta

Publications and source records attributed to J Lähdevirta.

At least 91 records · Page 5Linked to original sources
PubMed1979

Selective vitamin B12 malabsorption with proteinuria. Renal biopsy study.

Percutaneous renal biopsy were 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 deposit. 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.

Adolescent↗
PubMed1978

Electron Microscopy of Nephropathia Epidemica. Glomerular changes.

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.

Adolescent↗
PubMed1978

Renal sequelae to nephropathia epidemica.

Clinical data and renal biopsy findings were studied in 9 patients 4-5 years after the acute phase of Nephropathia epidemica. Laboratory data suggested slightly depressed tubular function, but glomerular function was normal. Light microscopy of renal biopsy specimens showed slight residual interstitial fibrosis and occasionally atrophic tubuli, tubular casts, increased number of hyalinized glomeruli, and minor changes in other glomeruli. Two specimens showed fibrotic scars in the cortex. Electron microscopy revealed degenerative changes in the glomeruli, arterioles and tubules. The immunohistochemical study showed no fixed immunoglobulins in the kidney. The study shows that practically complete and lasting clinical recovery follows the acute phase of Nephropathia epidemica and that the disease does not leave diagnostic structural changes in the kidneys.

Adult↗
PubMed1978

The role of small rodents and patterns of living in the epidemiology of nephropathia epidemica.

The epidemiological role of small rodents and certain human patterns of living for contraction of nephropathia epidemica (NE) was studied by interviewing 46 NE patients and 52 control subjects. The occurrence of small rodents in dwellings and cupboards was significantly commoner among NE patients than among control subjects. The results suggest a connection between NE and small rodents.

Adolescent↗
PubMed1978

Nephropathia epidemica: immunohistochemical study of pathogenesis.

Renal immunohistochemistry was studied in 21 patients with Nephropathia epidemica, a benign hemorrhagic fever endemic in northern Europe. Between days 4 and 25 after the onset of fever, scanty but distinct deposits containing immunoglobulins and C3 were detected in glomeruli and tubules. The occurrence of deposits was verified with electron microscopy. It is concluded that an immune complex mechanism plays a part in the pathogenesis of this disease. It is also evident that the febrile period coincides with the presence of immune complexes in the circulation.

Adolescent↗
PubMed1978

Electron microscopy of nephropathia epidemica. Renal tubular basement membrane.

Tubular basement membranes in kidney biopsies from 18 patients with nephropathia epidemica were studied by electron microscopy. Both in the cortex and in the medulla there was splitting of the basement membrane. Thickened basement membrane around occasional tubules contained membrane vesicles, usually empty but also with a core and a diameter of approximately 180 nm. Membranous convoluted structures and light finely fibrillar areas in the basement membranes were seen. Splitting of the basement membrane was most prominent in the medulla, and the membrane was filled with round to oval particles 55 to 470 nm in diameter. Of the possible mechanisms of damage at the basement membrane level in this disease, the findings suggest liberation of antigen from the tubular cells and reaction of circulating antibodies with the antigen in the basement membrane.

Adolescent↗
PubMed1977

Heme catabolism in human kidneys. Effect of various nephritides.

The role of the kidneys in heme metabolism was examined by determining heme oxygenase and biliverdin reductase activities in needle biopsy specimens from the kidneys of 11 female and 14 male patients with different renal diseases. The results show that both enzymes are present in human renal tissue. Our results indicate that heme oxygenase and biliverdin reductase increase slightly with age, but that there is no sex difference. A rising serum creatinine concentration is not reflected in the activity of heme degrading enzymes. Neither do the different types of nephritides, without detectable hemolysis, show significant differences in the renal activities of heme oxygenase and biliverdin reductase. This study thus outlines the basal physiological role of the human kidneys in heme degradation.

Adolescent↗
PubMed1977

An emerging zoonosis in Scandinavia -- nephropathia epidemica.

The paper reviews as zoonosis the disease called Nephropathia epidemica in north European countries. The etiology is as yet unsolved but a viral one is highly suspected with small rodents (voles and mice) as the source of infection. Based on the epidemiological peculiarities of the disease, the ecology of the agent and hypothetical ways of transmission of infection from small rodents to man are discussed.

Adult↗
PubMed1975

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.

Adolescent↗