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Biomedical subjects

S Olsen

Publications and source records attributed to S Olsen.

At least 109 records · Page 6Linked to original sources
PubMed1984

Ultrastructural analysis of human proximal tubules and cortical interstitium in chronic renal disease (hydronephrosis).

A systematic ultrastructural analysis of proximal tubule atrophy and cortical interstitial changes was carried out in human chronic nephropathy. The investigation was based on human hydronephrotic kidneys, which had been surgically removed and subsequently perfusion-fixed for light and electron microscopy. Normal kidney tissue, which was derived from nephrectomy specimens with pathological changes confined to part of the kidney or to the renal pelvis, was used for control material. A slight degree of proximal tubule atrophy was characterized by reduction of mitochondria and basolateral membranes, enlargement of large endocytic vacuoles and increased numbers of lysosomes containing lamellar material. In moderate atrophy these changes were further accentuated, and in addition there was an increasing loss of microvilli and a reduction of endocytic invaginations and small endocytic vacuoles. In severe atrophy all types of organelles were sparse and the architecture of the tubule cells greatly simplified. A distinctive feature of atrophic tubules was the presence in the tubule cells of large bundles of actin-like filaments, which were often associated with outpouchings of basal cell parts and basement membrane. The reduction of mitochondria and basolateral cell membranes and the changes of endocytic vacuoles and lysosomes indicate that proximal tubule atrophy also in early stages may be associated with impairment of tubular transport processes. Comparisons with previous observations in various types of experimentally induced tubule cell degeneration and with the ultrastructure of regenerating proximal tubule cells provide some evidence that degenerative changes as well as imperfect regeneration of tubule cells may contribute to the alterations of ultrastructure in tubular atrophy. It is suggested that changes of the cortical interstitium may be of pathogenic importance for the progression of tubular atrophy by altering the spatial relationships between tubules and capillaries.

Adult↗
PubMed1984

Clinical short term study of marginal integrity of resin restorations.

The marginal adaptation of 649 Durafill and Silux fillings in beveled and acid etched enamel cavities was assessed in a clinical study. The investigation included Class III with and without lingual extension, Class IV and Class V. The frequency of marginal discoloration and marginal gaps after 15 months was markedly reduced in all Classes when a low-viscous resin was used prior to application of the restorative.

Acid Etching, Dental↗
PubMed1984

Lithium induced interstitial nephropathy associated with chronic renal failure. Reversibility and correlation between functional and structural changes.

We have previously shown that administration of lithium to rats in the first weeks after birth results in a severe interstitial nephropathy. The aim of the present work was to study the relationship between functional impairment and structural lesions and to evaluate whether the nephropathy regresses after withdrawal of lithium. Three groups of animals were studied: 16 weeks-old controls (group A), rats treated with lithium for 16 weeks (group B) and rats treated for 8 weeks followed by 8 weeks without lithium (group C). Plasma urea and renal concentrating ability were determined and one kidney fixed by vascular perfusion with glutaraldehyde for light microscope morphometry. The results show a significant reduction in renal function after lithium treatment. There was a highly significant reduction in proximal tubular length and a pronounced increase in interstitial volume due to severe fibrosis. The total mass of glomerular tufts was also reduced, but not when this parameter was divided by the body weight. Sclerotic glomeruli were not observed. The structural and functional lithium-induced lesions are independent of sex and irreversible, since they persist 8 weeks after withdrawal of lithium. It is proposed that lithium-induced interstitial fibrosis is followed by proximal tubular atrophy with a reduction in the amount of functioning proximal tubules. This leads to a decrease in proximal tubular reabsorption of sodium and a disturbance in the glomerulo-tubular balance resulting in a decrease in glomerular filtration rate.

Animals↗
PubMed1984

Renal morphology in experimental vesico-ureteral reflux in pigs.

As part of a study of experimental vesicoureteric reflux 20 pigs were allocated into five groups according to the presence of reflux, infravesical obstruction and urinary tract infection. The pigs were followed for 20 weeks and thereafter the pathology of the kidneys were studied. It was confirmed that reflux and urinary tract infection produce reflux nephropathy and that the most severe lesions were found in case of dilatation of the upper urinary tract due to infravesical obstruction. It was also substantiated that sterile reflux in case of infravesical obstruction with pronounced dilatation of the upper urinary tract can produce reflux nephropathy.

Animals↗
PubMed1984

Hydatidiform mole in a Danish material. Morphology and cytogenetics. A preliminary communication.

Morphologic and cytogenetic analyses were performed on 15 evacuated conceptusses with a tentative diagnosis of hydatidiform mole. Nine of these presented with gross vesicles of which 7 were classified as complete and one as partial mole, the last having the characteristics of both types. Chromosomes from cultured villi were obtained from 7 of the 15 specimens; 3 were diploid and 4 triploid. The diploid cases were complete moles with all chromosomes of paternal origin. The four triploid cases--two partial moles and two abortions--were all paternally derived and caused by dispermy. The observations indicate that some moles share histologic features with both partial and complete moles. Two cases were cytogenetically consistent with but histologically different from partial moles.

Chromosome Aberrations↗
PubMed1984

A survey of nursing care for parents and infants with cleft lip and palate.

This survey of the hospital nurse's role in patient care when a child is born with an orofacial cleft included nursing assistance offered new parents, identification of specialists for habilitation of the child, and inservice nursing education programs. Findings from 52 hospitals indicated that adequate assistance and information concerning special services for parents and child were not available. Some hospitals offered inservice nursing education in care of parents and children with facial clefts. Suggestions are made concerning nursing education programs in cleft lip and palate.

Adult↗
PubMed1983

Characterization of ploidy level in bladder tumors and selected site specimens by flow cytometry.

The histopathological grade of atypia was compared with the ploidy level in biopsy specimens from bladder tumors and six grossly normal areas (selected sites). The study included investigation of 303 specimens from 45 patients. The results demonstrated a high correlation between the grade of atypia and the occurrence of aneuploid cell populations. The selected site specimens were diploid in patients with low grade malignant tumors, while high grade malignant tumors were associated with aneuploid selected site specimens in 20% of the cases. The divergence of ploidy level in the tumor and selected site specimens found in some cases clearly demonstrated that the carcinogenic process in the bladder may lead to clonal heterogeneity. Flow cytometric analysis seems suited for mapping of the ploidy levels in different parts of the bladder. The possible importance of the additional information is discussed.

Aneuploidy↗
PubMed1983

Spontaneous dissecting aneurysm of the renal arteries. A case and a review of the literature.

A case of dissecting aneurysm of the renal arteries is presented. The patient suffered from an intractable subarachnoid bleeding and the kidneys had been selected for transplantation. One kidney was never transplanted, the other was transplanted and rejected after few days. Dissecting aneurysms were present in the main artery and its major ramifications in both kidneys. Many investigators have claimed that dissecting aneurysm and fibromuscular dysplasia of the renal artery are different stages of but one disease. A review of the accumulated literature on dissecting aneurysm of the renal artery reveals, however, that this disorder shows a preponderance of middle-aged men, whereas fibromuscular dysplasia of the renal artery affects adolescent girls. It is concluded that the two disorders of the renal artery most likely represent different vascular diseases.

Aortic Dissection↗
PubMed1983

Ultrastructural lesions in lightmicroscopically defined types of glomerulonephritis. A blind and semiquantitative study.

Current classification of glomerulonephritis (GN) is based primarily on light microscopical (LM) histopathological criteria. The aim of the present study was to investigate the occurrence and severity of a number of electron microscopical (EM) lesions in different LM defined classes of GN in order to determine the degree of homogeneity of these classes and the degree of specificity of various EM lesions seen in GN. The analysis was performed using a blind, systematic and semiquantitative method and applied on 91 consecutive biopsies from patients with GN as well as on 11 reference biopsies. Most of the EM lesions were not restricted to a single or a few light microscopically defined classes of GN. EM lesions having direct LM counterparts used as classification criteria were generally present with high scores in the corresponding LM classes but were also present in other types of GN. When the EM-findings were compared with our original classification of the 91 biopsies it was found that about 13% of all biopsies were classified erroneously using only LM. Thus, the groups obtained with the presently used LM classification system are quite heterogenous with respect to ultrastructure and probably with respect to pathogenesis. On the other hand, it appears that many ultrastructural lesions display a more or less continuous spectrum of changes which therefore are difficult to use for classification purposes.

Biopsy↗
PubMed1983

Arterial hypertension in chronic glomerulonephritis. An analysis of 310 cases.

310 cases of glomerulonephritis classified morphologically according to the criteria of the WHO were analyzed retrospectively in order to determine the frequency of arterial hypertension. The overall prevalence of arterial hypertension was 61%. Hypertension was most frequent and severe in membranoproliferative and sclerotic glomerulonephritis, but often mild and transient in extracapillary glomerulonephritis. Hypertension usually developed during the early stages of the disease when kidney function was well preserved and in only 16% was hypertension first seen during the uremic stage. No correlation was found between hypertension and the presence of the nephrotic syndrome. During dialysis, hypertension was present in 78%; in 90% of these patients hypertension was "controllable" and in 10% it was "uncontrollable".

Adolescent↗
PubMed1982

Negative v positive schizophrenia. Definition and validation.

We developed criteria for dividing the schizophrenic syndrome into three subtypes: positive, negative, and mixed schizophrenia. Positive schizophrenia is characterized by prominent delusions, hallucinations, positive formal thought disorder, and persistently bizarre behavior; negative schizophrenia, by affective flattening, alogia, avolition, anhedonia, and attentional impairment. In mixed schizophrenia either both negative and positive symptoms are prominent, or neither is prominent. We explored the validity of these criteria in a variety of ways. Significant differences between the three types were noted using external validators such as premorbid adjustment, indices of cognitive dysfunction, ventricular brain ratio, and course in hospital. The correlational structure of the symptom complexes also provided further support for our approach to subtyping.

Adult↗
PubMed1982

Severe functional and structural changes caused by lithium in the developing rat kidney.

Lithium (Li) was administered to rats during maternal pregnancy and/or 8 weeks post-natally, to study the effects on renal function and structure in the developing kidney. Plasma Li was 0.5-1.0 mmol/l 3 and 8 weeks post-natally. Functionally, post-natal Li leads to growth retardation, polyuria with lowering of renal concentration ability, and uremia associated with as much as 80% lowering of the normal glomerular filtration rate (GFR). Pre-natal Li alone did not affect the concentrating ability but caused a 20% increase in GFR when evaluated 8 weeks post-natally. Post-natal Li caused very severe structural changes, consisting of up to 3 mm cortical cysts (= dilated distal convoluted tubules), extensive interstitial fibrosis with cell infiltration, and atrophy of the cortical collecting ducts. Morphometric measurements showed a significant reduction in the volume of the proximal tubular cells. Pre-natal Li caused only slight structural changes, and animals treated both pre- and post-natally were less affected than animals treated post-natally only. The structural changes caused by post-natal Li were unrelated to changes in the concentrating ability but showed a significant correlation with the lowering of the GFR. It is concluded that the post-natally developing rat kidney is particularly sensitive to the nephrotoxic effects of Li, which in low concentrations causes impairment of renal function, leading to uremia. Pre-natal Li exposure by maternal lithium treatment had little effect on renal function and structure when evaluated post-natally.

Animals↗
PubMed1982

Pyelorenal backflow in rabbits following clamping of the renal vein and artery: radiologic and microscopic investigation.

Retrograde pyelography was carried out in rabbits during and following temporary clamping of either the renal artery and vein together or the main renal vein alone. Pyelosinous backflow was observed in all kidneys and pyelovenous backflow in 16 of the 18 kidneys, occurring at intrapelvic pressures between 50 and 100 mmHg. During simultaneous complete renal artery and vein occlusion intrarenal backflow occurred in all 3 kidneys examined while it was observed in 3 of 6 kidneys when the pyelography was performed 5 min after removal of the clamp. During complete renal vein occlusion filling with contrast medium of the central intrarenal veins occurred in all 3 kidneys but only in 3 of 6 kidneys examined after the clamp had been removed. Microscopically, pyelosinous backflow was explained by vital tears in the fornix of the pelvic cavity. Tears extending into the kidney parenchyma were only observed in kidneys with intrarenal backflow at pyelography.

Animals↗
PubMed1982

Transabdominal isthmic cerclage for the treatment of incompetent cervix.

During the period from 1973 to 1980 transabdominal isthmic cerclage was performed on 32 patients. Twenty-nine patients experienced 35 pregnancies. In 23 cases (79%) the diagnosis was based on one or several second-trimester abortions. In the remaining 6 cases the diagnosis was based on clinical findings of an abnormal cervix. Both groups had fetal loss in first and third trimester. The operation was performed before pregnancy or during pregnancy up to the 14th week. The fetal salvage rate rose from 12% to 91.4%, and the prematurity rate was 6.7% after operation. Only one pregnancy was terminated prematurely, due to forcible labor.

Abortion, Spontaneous↗
PubMed1982

Early changes in renal distal convoluted tubules and collecting ducts of lithium-treated rats: light microscopy, enzyme histochemistry, and 3H-thymidine autoradiography.

The early effects of lithium on the kidney were studied in rats receiving a moderate daily dose (serum-Li: 0.5 to 0.8 mM per liter) for 3, 7, and 21 days. Enzyme histochemical reactions for acid and alkaline phosphatase, glucose 6-phosphatase, succinate and alpha-glycerophosphate dehydrogenase, and NADH tetrazolium reductase revealed changes confined to distal convoluted tubules and collecting ducts. The distal convoluted were unchanged at 3 days of treatment. At 7 days, a decrease in succinate dehydrogenase and NADH tetrazolium reductase and an increase in alpha-glycerophosphate dehydrogenase were noted. These changes were more conspicuous at 21 days and accompanied by tubular dilation and changes in light microscopic cellular morphology. In the collecting ducts, a cell enlargement and an increase in mitochondrial oxidative enzyme activities began to appear at 3 days, becoming more pronounced at 7 and particularly at 21 days. At 7 and even more at 21 days, a cellular hyperplasia was evident in the collecting ducts, and autoradiography after 3H-thymidine incorporation showed a marked increase in DNA synthesis in the collecting duct cells. The changes observed in the collecting ducts were most pronounced near the limit between the outer and the inner zone of the medulla. In conclusion, the rats developed morphologic changes at 3 to 7 days of treatment. The changes include (1) signs of cellular damage in the distal convoluted tubules and (2) hyperplasia and signs of increased functional activity in the collecting ducts.

Animals↗