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Biomedical subjects

T Hovig

Publications and source records attributed to T Hovig.

At least 91 records · Page 5Linked to original sources
PubMed1978

Plasma lipoprotein alterations and morphologic changes with lipid deposition in the kidney of patients with hepatorenal syndrome.

Four patients with advanced liver disease and progressive renal failure compatible with the diagnosis of hepatorenal syndrome have been studied. All four patients had low lecithin:cholesterol acyltransferase activity in plasma, and the concentration of cholesteryl esters was markedly reduced. The main lipoprotein classes were abnormal with an increased content of polar lipids. Electron microscopy of negatively stained lipoproteins from two of the patients (H.K. and I.A.) revealed large particles with layered membranes (700 to 2000 A in diameter) corresponding to the large molecular weight fraction of the low density lipoproteins. These structures were not present in the low density lipoproteins from the other two patients. In the renal biopsy from H.K. and in the necropsy specimen from I.A. deposition of osmophilic material was found in the glomeruli (especially located subendothelially), in the basement membrane, and in the mesangial regions. The deposits were similar to those we have previously described in patients with familial lecithin:cholesterol acyltransferase deficiency and most probably represent cholesterol and phospholipids. It is suggested that the renal deposition of lipid may be related to the large molecular weight low density lipoprotein fraction and that the mechanisms involved in this lipid deposition are similar to those occurring in familial lecithin:cholesterol acyltransferase deficiency.

Female↗
PubMed1977

The effects of cholesterol/fat feeding on lipid levels and morphological structures in liver, kidney and spleen in guinea pigs.

Guinea pigs were fed a semisynthetic diet containing 10 per cent (by weight) cottonseed oil with or without 1 per cent cholesterol. In the animals fed fat, the lipid levels and the morphology remained normal in all tissues studied. Concomitantly with a marked accumulation of cholesteryl ester (CE) in the liver, however, many microscopical changes occurred in guinea pigs fed cholesterol/fat. A prominent deposition of lipids in vacuoles, mostly without delimitating membranes, where observed at centrilobular sites. Multivacuolated, secondary lysosomes, membrane bound lipid vacuoles (lipolysosomes) and myelin figures were found both in hepatocytes and Kupffer cells. Myelin figures and crystalline clefts were observed more often in Kupffer cells than in hepatocytes. The granular endoplasmic reticulum in the Kupffer cells was grossly dilated and filled with an amorphous material. Both the biochemical and the morphological findings in hepatocytes and Kupffer cells are very similar to those observed in cholesteryl ester storage disease and in Wolman's disease. These two lipid storage diseases are both related to deficiency of an acid lipase in the liver. Measurement of the acid liver CE hydrolase in guinea pigs fed fat and in those fed cholesterol/fat showed similar activity. A relative deficiency of this enzyme activity could be the reason for the development of the enormous CE storage in guinea pig livers. These findings suggest that guinea pigs fed cholesterol/fat, in some respects, can be used as a model for Wolman's disease and cholesteryl ester storage disease. We did not find any microscopical changes in the kidneys from animals fed cholesterol/fat, thus indicating that the experimental condition it not useful as a model for studies of the kidney changes in lecithin:cholesterol acyltransferase (LCAT) deficiency.

Animals↗
PubMed1977

Renal failure in familial lecithin-cholesterol acyltransferase deficiency.

Familial lecithin-cholesterol acyltransferase deficiency is a hereditary disorder of lipid metabolism. Lipid material is deposited in the kidneys, the glomerular capillary basement membrane is irregularly thickened, detachment and even loss of endothelial cells are seen in the glomeruli. Proteinuria was present in 8 out of 9 cases studied, usually it has not been detected before the age of 15-20. After 15-30 years with symptomless proteinuria, terminal renal failure has developed in 6 of the patients. Possible pathogenetic mechanisms of the renal damage is discussed; a large-molecular-weight low-density lipoprotein is suggested to be an important factor.

Acyltransferases↗
PubMed1977

The ultrastructure of normal digital flexor tendon sheath and of the tissue formed around silicone and polyethylene implants in man.

Three normal digital flexor tendon sheaths and the corresponding tissue formed around five silicone rod tendon implants, two silicone rubber mammary prostheses and one polyethylene tubing implant have been examined by light microscopy and by transmission and scanning electron microscopy. No principal difference in morphology was found. The surface facing tendon or implant was almost invariably covered with an irregular layer of amorphous material and filaments; only occasionally were collagen fibrils or cells exposed. Beneath the surface there were abundant collagen fibrils and some cells; besides fibroblasts, cells rich in filaments and often with numerous glycogen granules, mitochondria and peripherally located vesicles were found. These cells were frequently surrounded by a thick layer of an amorphous matrix. The results indicate that the implants caused remarkably little tissue reaction.

Adult↗
PubMed1976

Functional and ultrastructural studies of the effects of human interferon on cell membranes of in vitro cultured cells.

The effect of human leukocyte interferon on cultured U-amnion cells was examined, and several biological parameters were registered. Multiplication of Vesicular stomatitis virus and the virus-produced cytopathogenic effect was prevented. The growth rate of uninfected cells was reduced, as well as the spontaneous release of 3H-uridine. These effects were observed following treatment with 10 units of interferon per ml. No morphological alterations could be detected by scanning electron microscopy after 24 or 72 hours treatment with up to 2000 units interferon per ml.

Cell Division↗
PubMed1976

Nephrotic syndrome in ulcerative colitis.

Complicating disorders in various organs outside the intestinal tract are common in ulcerative colitis. This report deals with the occurrence of nephrotic syndrome in two patients with long-standing ulcerative colitis. In the patient studied in most detail, 2 episodes have taken place, the first developing into uremia. After colectomy had been performed, rapid improvement of renal function took place. The morphological changes in kidney biopsies were compatible with the presence of focal glomerular sclerosis. Activity in the complement system and a favorable response to steroid treatment indicate that humoral immune mechanisms are of pathogenetic importance with regard to the renal disease in these two patients. To our knowledge nephrotic syndrome has not previously been described as a complication to ulcerative colitis.

Adult↗
PubMed1975

Needle-like crystals in plasma cells in a patient with a plasma cell proliferative disorder.

A patient with a plasma cell proliferative disorder and a monoclonal IgG-kappa protein in the serum was observed over a period of four years. Two unusual features were seen in this patient: (1) An apparently benign course in spite of relatively large and slowly increasing amounts of Bence Jones protein (monoclonal kappa light chains) in the urine, and (2) crystalline structures located outside the cisternae of the endoplasmic reticulum in a large number of bone marrow plasma cells. The crystals, which ultrastructurally appeared to be composed of protein material, were not stained by immunofluorescent antisera to immunoglobulins. They were, however, observed only in cells staining for gamma heavy and kappa light chains. This suggest an association between the crystalline structures and the synthesis of monoclonal immunoglobulin proteins.

Bence Jones Protein↗
PubMed1975

Congenital dyserythropoietic anaemia with features of both type I and TYPE II.

A 13 year old girl with the typical clinical and haematological picture of congenital dyserythropoietic anaemia (CDA) is reported. The bone marrow is highly cellular with 70 per cent erythroid cells, and 28% bi- and multinuclear cells among the orthochromatic and polychromatic erythroblasts. Moderate megaloblastoid changes are present. On light microscopy the findings are in agreement with those described in CDA type II. On electron microscopy both the cytoplasmatic changes described as typical of CDA type II, and the nuclear changes found in type I can be demonstrated. The acidified serum test (Ham test) is negative with normal sera. The patient's red blood cells show increased agglutinability with anti-I and and anti-I antibodies, but no haemolysis. Total serum lipids are about 50% of the normal average. All lipoprotein classes are lowered to about the same extent. The total phospholipid content of the erythrocytes is slightly reduced, with a moderate, relative increase of the lecithin fraction and a decrease of the sphingomyelin fraction. Doubts can be raised about the tenability of the current classification of CDA based on morphological and serological criteria, especially about the distinction between types I and II.

Adolescent↗
PubMed1975

Renin-secreting renal tumour with severe hypertension. case report with tumour renin analysis, histopathological and ultrastructural studies.

A 25-year-old man presented with severe hypertension associated with hypokalemia, elevated plasma renin level and secondary hyperaldosteronism. Malignant phase hypertension and renal artery stenosis were ruled out, and a preoperative diagnosis of renin-secreting renal tumour was made on the basis of higher concentrations of renin in the left than in the right renal venous plasma in spite of normal findings on selective renal arteriography. By removal of the affected kidney the tumour was found and it had a very high content of renin. Following the operation the plasma renin level, serum aldosterone concentration and BP became normal. We present a histopathological description and an ultrastructural study of the tumour.

Adult↗