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J H Magnus

Publications and source records attributed to J H Magnus.

At least 37 records · Page 2Linked to original sources
PubMed1995

A prospective evaluation of antithyroid antibody prevalence in 100 patients with rheumatoid arthritis.

The prevalence of thyroid antibodies in 100 patients with rheumatoid arthritis in Northern Norway was studied. The serological data were compared with those from a major population survey in the same area. Compared to the prevalence in the normal population, the present study demonstrates that patients with rheumatoid arthritis have a higher prevalence of antibodies to both thyroid microsomal antigen and thyroglobulin.

Adult↗
PubMed1994

Characterization of proteoglycans associated with mouse splenic AA amyloidosis.

We here report for the first time on the chemical characteristics of proteoglycans associated with mouse splenic reactive AA amyloid. Amyloid was induced in CBA/J mice by two different procedures; conventional casein treatment and by employing Freund's complete adjuvant, accelerated by Trypan Blue. Pulse-labelling was employed at distinct stages during amyloid development, followed by [35S]proteoglycan characterization of organ extracts. Repetitive 35S injections were also administered during the phase where amyloid deposition occurred most rapidly. Proteoglycans were extracted with guanidine in the presence of protease inhibitors and purified. The results showed that the production of proteoglycans is dramatically enhanced during amyloidogenesis, the glycosaminoglycan and proteoglycan accumulation being not only dependent on alterations in proteoglycan catabolism, but rather on increased synthesis. The increment could be demonstrated even at the stage before microscopic detection of amyloid deposits, clearly suggesting that the upregulation of proteoglycan expression precedes amyloid fibril formation. Two major proteoglycans were found to accumulate in advanced splenic amyloid; one a heparan sulphate proteoglycan of approx. 200 kDa with a core protein of 70 kDa, the other a chondroitin sulphate proteoglycan of smaller size. Moreover, free dermatan sulphate chains seemed to specifically accumulate in the organs during amyloid fibrillogenesis. We suggest that free glycosaminoglycans may be a specific feature of amyloidosis and that different proteoglycans and glycosaminoglycans play a role in formation and stabilization of amyloid fibrils in vivo.

Amyloidosis↗
PubMed1994

[Rheumatic fever--does it exist in Norway today?].

During the last 30 years, acute rheumatic fever has been a curiosity in Norway, and only five cases have been reported to MSIS (National Notification System for Infectious Diseases, Norway) in the 1990s. Even so, during the period 1990 to 1992 99 patients were discharged from Norwegian hospitals with the diagnosis acute rheumatic fever. Could the increase in the number of group A-streptococci in the last years have led to a corresponding increase in the incidence of acute rheumatic fever? If so, could such an increase have escaped our attention? We present an updated review of acute rheumatic fever and the case of a young soldier.

Acute Disease↗
PubMed1994

[Polymyalgia rheumatica and temporal arteritis. New aspects of diagnosis, treatment, prognosis and risk of cancer].

The incidence of polymyalgia rheumatica and temporal arteritis is increasing, mainly in elderly people. The risk of cancer during a lifetime is high in patients with positive biopsy of the temporal artery, but polymyalgia rheumatica and temporal arteritis are not to be considered as paraneoplastic syndromes. Temporal arteritis can appear in patients under treatment for polymyalgia rheumatica, and polymyalgia rheumatica can be accompanied by arthritis. Various new aspects of diagnoses and treatment are discussed.

Giant Cell Arteritis↗
PubMed1994

[The significance of proteoglycans in several diseases].

A prominent feature in several diseases is the accumulation of connective tissue. The ultimate result of high levels of extracellular matrix is organ failure and death, evident in diseases such as liver fibrosis, diabetes and amyloidosis. Among the extracellular matrix components, proteoglycans play a basic role in several pathological conditions. In the development of atherosclerosis they provide an anchor for lipoprotein lipase on the endothelial wall, sequester lipoproteins in the subendothelial matrix and present lipoproteins to macrophages. In diabetes these proteoglycans have a lower charge, such that the network has a reduced capacity to retain negatively charged proteins. In fibrosis and amyloidosis the synthesis of proteoglycans and matrix is increased and large amounts are deposited at the expense of tissue-specific cells. Some of the conditions mentioned can be ameliorated by changes in the diet.

Amyloidosis↗
PubMed1994

Interaction between circulating amyloid fibril protein precursors and extracellular tissue matrix components in the pathogenesis of systemic amyloidosis.

Amyloidosis is a heterogeneous group of diseases characterized by deposition of a fibrillar, proteinaceous material, amyloid, in various tissues and organs. Increasing knowledge about the different proteins that constitute the amyloid fibrils has made it possible to classify amyloidosis by the fibril protein, which appears more rational than the traditional classification by its clinical expression. A serum protein is the precursor of the amyloid fibril protein in the various systemic forms of amyloidosis. Although the chemical composition of amyloid is presently well known, the pathogenetic processes that convert such proteins into a fibrillar form and lay them down in the tissues are far from clarified. We suggest some pathogenetic mechanisms for amyloid deposition, involving different types of fibril protein, their precursors, the extra-fibrillar amyloid P component, glycosaminoglycans, proteoglycans, and calcium with special reference to experimental work from our research group.

Amino Acid Sequence↗
PubMed1993

[Graduates from Tromsø--do they stay in Northern Norway? Geographic origin determines selection of professional practice location in Northern Norway].

The impact of the Medical School, University of Tromsø on the distribution of physicians in rural areas in North Norway was evaluated by means of a mailed questionnaire. The survey covered eleven graduation classes (417 physicians), and the response rate was 84.2%. The establishment of a new medical school in North Norway has clearly had beneficial effects: A total of 56.1% of the graduates stay on as doctors in these areas. Among those who also grew up in the northern parts of Norway, the proportion is 82.0%, compared with graduates who grew up in the southern parts where the proportion is 37.7%. The results clearly demonstrate that one of the main objectives of the Medical School at the University of Tromsø, to educate physicians who prefer to work in these areas, has been achieved.

Arctic Regions↗
PubMed1993

[Elective periods in the medical curriculum. Madness or academic challenge?].

The medical curriculum at the University of Tromsø reserves 23 weeks, divided into four periods, for elective work, including 12 weeks at the end of the fifth year, when the student carries out an independent study and writes a short thesis. 84.2% of 417 physicians (graduation year 1979-89) answered a mailed questionnaire asking them to evaluate these periods. The postgraduates report high levels of satisfaction with this part of the curriculum, thought they had benefited from it. As many as 86.0% evaluate the gain from the first three periods as good or very good. 26.8% started working on their thesis before the final 12 week period. 88.1% found the fourth, and longest period, assigned for their thesis to be an important part of the curriculum. One third had also published their material, half of these in international journals. 75.6% found the skills acquired during the final elective period to be useful in their present work, independent of specialty.

Attitude of Health Personnel↗
PubMed1993

[Evaluations and examinations at the Tromsø medical school. Evaluation by students after graduation].

The medical curriculum at the University of Tromsø is based on an organ-system model with full integration of the three main disciplines (basic science, clinical and community medicine). There are only three examinations during the six-year course. We present the results of a survey among the first 417 physicians educated at the Medical School in Tromsø. A mailed questionnaire was answered by 84.2%. More than 80% stated that it was of great importance to evaluate the form and contents of the lectures and their supervisors' teaching abilities. More than 96% found that integration of the examinations was achieved in accordance with the intention. Furthermore, the examinations were also relevant for them as physicians.

Attitude of Health Personnel↗
PubMed1993

On the association between amyloid fibrils and glycosaminoglycans; possible interactive role of Ca2+ and amyloid P-component.

We have previously reported the specific association of glycosaminoglycans (GAG) and proteoglycans (PG) with amyloid fibrils and characterized the polysaccharides directly extracted from amyloid-laden tissues. In the present study we further elucidate the association between purified amyloid fibrils and GAG/PG with special reference to those GAG/PG associated with amyloid P-component (AP) and the interactive role of Ca2+ ions. Amyloid fibrils were isolated from human hepatic AA amyloid employing water extraction with and without preceding removal of AP, an extrafibrillar protein component of all amyloids, using sodium citrate. GAG/PG co-isolated with the amyloid extracts, with and without AP, were isolated and characterized. Agarose-affinity chromatography of extracts containing AP was performed, and the GAG associated with this extrafibrillary protein were characterized as well. Several different GAG/PG populations were demonstrated in the various extracts. The abolition of calcium-dependent binding markedly influenced the amount of GAG/PG recovered in the fibril extracts, as well as the total amount of amyloid material obtained. Thus, it seems that calcium plays an important role in the association between the fibrils and the sugar moieties, and that a significant fraction of the GAG found in amyloid exhibits a Ca(2+)-dependent fibril-GAG interaction. No significant difference in the proportion between galactosaminoglycans and glucosamines was, however, disclosed when the two extraction protocols were compared, suggesting that no particular GAG species has a higher affinity for the fibrils themselves. Both dermatan/chondroitin sulphate and heparan sulphate identified in the present study exhibited a Ca(2+)-dependent interaction with AP, supporting previous findings. However, the amyloid-associated galactosaminoglycans found, especially the large PG appearing in small amounts, seemed to have a higher affinity for the extrafibrillar AP than the other GAG.

Amyloid↗
PubMed1993

Rural doctor recruitment: does medical education in rural districts recruit doctors to rural areas?

The impact of the University of Tromsø Medical School on the distribution of doctors in rural areas in northern Norway was evaluated by a postal questionnaire. The survey covered 11 graduation years (417 doctors), and the response rate was 84.2%. The establishment of a new medical school in northern Norway has clearly had beneficial effects: a total of 56.1% of the graduates stay in these remote areas. Of those who also spent their youth in northern Norway the proportion is 82.0%, compared to graduates who lived in the southern parts of the country while growing up (37.7%). The results clearly demonstrate that one of the main goals for the Medical School at the University in Tromsø, to educate doctors who prefer to work in these rural areas, has been accomplished.

Attitude of Health Personnel↗
PubMed1993

Writing a scientific paper as part of the medical curriculum.

The curriculum at the Medical School, University of Tromsø reserves 23 weeks for optional studies, including a period of 12 weeks at the end of the fifth year when the students carry out an independent study and write a short thesis. Of the first 417 doctors (graduation year 1979-89) from Tromsø 84.6% answered a postal questionnaire asking them to evaluate this part of the curriculum. These postgraduates report high levels of satisfaction with and benefit from this part of the curriculum. A total of 26.8% started working on their thesis before the final 12-week period, 32.6% had also published their study, half of these in international journals, and 75.6% found that the skills acquired during the final optional period had been useful in their subsequent work, irrespective of specialty. In conclusion, postgraduates consider their work in preparing a scientific paper as an important and integral part of medical studies.

Curriculum↗
PubMed1993

Purification of amyloid-associated heparan sulphate proteoglycans and galactosaminoglycan free chains from human tissues.

Basement membrane-associated heparan sulphate proteoglycans have been demonstrated immunohistochemically in organs from patients afflicted with various types of amyloidosis. In a recent report, we were able to isolate and partly characterize a basement membrane-associated heparin sulphate proteoglycan from human hepatic amyloid. In the present study proteoglycans were extracted with guanidine from human amyloid-laden kidney, spleen and lymph nodes. All tissues extracted with guanidine contained both heparan sulphate proteoglycan (HSPG) and galactosaminoglycan (CS/DS) free chains. Tissue staining using a monoclonal antibody against basement membrane HSPG revealed the presence of HSPG in amyloid deposits in kidney and spleen. Furthermore, following SDS-PAGE of HSPG from kidney after deaminative cleavage of the HS chains, a 15-kDa and 80-kDa protein appeared, probably representing the core protein(s). In lymph node HSPG, three core proteins of 65, 30 and 25 kDa could be demonstrated on SDS-PAGE, the first reacting with the anti-basement membrane HSPG antibody when subjected to Western blotting subsequent to SDS-PAGE. By immunohistochemistry, we failed to demonstrate any staining of the renal and splenic tissue sections employing an antibody against the decorin core protein.

Adult↗
PubMed1992

Isolation and partial characterization of heparan sulphate proteoglycans from human hepatic amyloid.

Proteoglycans were isolated from human amyloidotic liver by extraction with guanidine, followed by trichloroacetic acid precipitation, DEAE-Sephacel ion-exchange chromatography, and Sepharose CL-6B gel chromatography. A significant portion of the material was found to be free chondroitin/dermatan sulphate chains (30%), whereas the predominant part was heparan sulphate proteoglycan (HSPG) (70%). The approx. molecular mass of the HSPG was 200 kDa, as measured by gel electrophoresis and gel chromatography. The molecular mass of the core protein was shown to be 60 kDa by SDS/PAGE following de-aminative cleavage of the heparan sulphate chains. The heparan sulphate chains were liberated from the core protein by alkali treatment and found to have a molecular mass of approx. 35 kDa by Sepharose CL-6B gel chromatography. The core protein was shown, by immunoblotting, to react with a monoclonal antibody against bovine basement membrane HSPG. The presence of HSPG in amyloid deposits was further confirmed by immunohistochemistry on tissue sections from amyloidotic liver using the same antibody.

Amyloid↗
PubMed1991

Glycosaminoglycans in extracts of cardiac amyloid fibrils from familial amyloid cardiomyopathy of Danish origin related to variant transthyretin Met 111.

We have previously demonstrated an association between secondary AA type amyloid fibrils and glycosaminoglycans (GAGs) in human liver. The present study was aimed at investigating whether a similar association could be demonstrated in isolated cardiac amyloid fibrils from a unique Danish family with amyloid cardiomyopathy related to variant transthyretin (TTR) with a single amino acid substitution of a methionin for leucine at position 111 (TTR Met 111). Using gel filtration and ion exchange chromatography, significant amounts of GAGs were detected in close association with purified myocardial amyloid fibrils, whereas only trace amounts of polysaccharides were present in the corresponding normal preparation. The GAGs were identified as 50% chondroitin sulfate, 33% heparin/heparan sulfate, and 17% hyaluronan. With the methods used the amyloid associated GAGs appeared as high molecular weight free polysaccharide chains, and not as part of intact proteoglycans (PGs) in the fibril extracts. We conclude that the association between purified amyloid fibrils and GAGs may be a general feature of amyloid deposits. Also, we suggest that the proportion of different GAGs in the amyloid deposits may depend both on the organ or tissues affected and the type of proteins making up the fibrils.

Adult↗
PubMed1991

Macromolecular properties of glycosaminoglycans in primary AL amyloid fibril extracts of lymphoid tissue origin.

We have previously demonstrated the presence of glycosaminoglycans (GAGs) in water extracts of secondary AA amyloid fibrils. In the present study we isolated significant quantities of GAGs from fibril extracts of immunoglobulin light chain (AL) type derived from the spleens from two patients afflicted with primary amyloidosis. Employing ion-exchange chromatography and gel filtration subsequent to various specific chemical and enzymatic treatments, different types of high molecular weight GAGs were found in both preparations, but not in the corresponding normal splenic extracts. The amyloid-associated GAGs of the extracts derived from one patient consisted of 60% dermatan sulphate and 40% heparan sulphate whereas those obtained from the second spleen were 25% dermatan sulphate and 75% heparan sulphate. The heparan sulphate fraction occurred in the form of proteoglycans, whereas the dermatan sulphate apparently occurred as free GAG chains, resembling the data recently obtained from AA amyloid fibril extracts.

Amyloid↗