Biomedical subjects

J H Magnus

Publications and source records attributed to J H Magnus.

At least 19 recordsLinked to original sources

PubMed2000

Hormone replacement therapy: knowledge, attitudes, self-reported use - and sales figures in Nordic women.

OBJECTIVES: To evaluate knowledge about, attitudes towards and use of hormone replacement therapy (HRT) in Norwegian women - and to compare self-reported use with sales statistics of HRT in the Nordic countries during recent years. MATERIAL AND METHODS: Random samples of Norwegian women age 16-79 were interviewed by the Central Bureau of Statistics in 1994 (n=737), in 1996 (n=665) and in 1998 (n=680). Statistics on the sale of estrogen were provided by the Norwegian Medical Depot and Nordic Council on Medicines. RESULTS: One in three women had received information about HRT during the last 2 years (1994), mainly through weekly magazines and physicians. The proportion answering in accordance with the prevailing view of HRT's effects ('correct knowledge') varied from 36.4 to 47.2%. Those informed by a physician possessed correct knowledge, had positive attitudes towards HRT and were willing to use HRT more often than women informed through other channels. Women with a high level of education had received information and had correct knowledge more often than others, but they were still less willing to use HRT and did not use HRT more often than the less educated. In the age group 45-69 years the use of HRT was 16.3% in 1994, 19.1% in 1996 and 19. 1% in 1998 (P=0.421, trend). In addition to received information, attitudes towards and knowledge about estrogen were the most important factors predicting use of HRT after adjusting for other variables. According to sales figures, the use of systemic estrogen in Norway has increased more than 360% since 1990. Although no other Nordic country has experienced a corresponding increase, Iceland had the highest sales figures in 1997. CONCLUSIONS: Based on the limited proportion of women receiving information on HRT and the ambivalence found in groups of educated women, we suggest that more and better information should be given middle-aged women to make them better able to make informed choices regarding use of HRT.

Adolescent↗

PubMed2000

Walking after stroke: does it matter? Changes in bone mineral density within the first 12 months after stroke. A longitudinal study.

Stroke patients have increased risk of hip fractures. Nearly all fractures occur on the hemiplegic side, and reduced bone mineral density (BMD) may be an important predisposing factor. The aim of this study was to investigate the degree of demineralization within the first year after stroke, and to elucidate a possible difference in patients with high versus low ambulatory levels. Forty acute stroke patients were followed (17 initially wheelchair-bound and 23 initially ambulatory). BMD was measured in the proximal femur bilaterally at a mean 6 days, 7 months and 1 year after stroke onset using dual-energy X-ray absorptiometry. Ambulatory status was independently associated with changes in BMD (p < or = 0.005) 1 year after stroke. The 17 initially wheelchair-bound patients had a significant 10% reduction in BMD at the paretic side and 5% reduction at the non-paretic side (p < 0.001), while the 23 patients initially able to walk had a significant loss (3%) only at the paretic side (p = 0.01). The analysis also indicated that the major reduction in BMD took place within the first 7 months. Two months after stroke 12 of the wheelchair-bound patients had relearned to walk. At the paretic side the 1 year changes in BMD in the patients who stayed wheelchair-bound, the patients who re-learned to walk within the first 2 months and the patients who were able to walk throughout the study were 13%, 8% and 3%, respectively, and a statistically significant trend with ambulatory level was found (p = 0.007). This study provides clear evidence that lack of mobility and weight-bearing early after stroke is an important factor for the greater bone loss in the paretic leg, but that relearning to walk within the first 2 months after stroke, even with the support of another person, may reduce the bone loss after immobilization.

Acute Disease↗

PubMed1999

The Tromsø Study: artifacts in forearm bone densitometry--prevalence and effect.

Suboptimal performance of bone densitometer, operator and/or subject may cause artifacts of consequence both for individual patient management and research. The prevalence and effects of such artifacts are largely unknown in densitometry. A cross-sectional population-based study was carried out of artifacts in forearm bone densitometry with single X-ray Absorptiometry (SXA) of the nondominant hand (distal and ultradistal site). After the screening, all scans were reviewed for artifact detection and reanalysis. The effect on the bone mineral density (BMD) result was found by comparing artifactual scans with a reanalyzed version or with normal repeat scans. All women aged 50-74 years, all men aged 55-74 years and 5-10% samples of other age groups aged >/=25 years attending the fourth Tromso health study were invited to have bone densitometry. The response rate from the background population was 80% (n = 7948). Fourteen percent of subjects had a movement artifact at either the distal or ultradistal site. The individual BMD variation was twice as large in scans with a movement artifact (0.94%) compared with normal scans (0.58%) (p = 0.0027). The radial endplate was inaccurately detected in 74% of the scans. Reanalysis of these scans led to a mean 3.8% decrease in the BMD value and an increase in the prevalence of osteoporosis of 10%. Artifacts were thus common, and their effects were clinically relevant in forearm bone densitometry. Artifacts and their effects need to be characterized in other bone densitometry settings also.

Absorptiometry, Photon↗

PubMed1998

[Normal bone remodelling--what can go wrong in osteoporosis?].

The skeleton is a metabolically active organ in constant change and renewal. Specialised cells are responsible for resorbing and synthetizing bone matrix. The process of bone remodelling, by removing old and damaged bone tissue and replacing it with new, is necessary for conserving the integrity of bone. In recent years, research has given new insight into the fine relationship between different cell types in bone tissue. This has enhanced our understanding of the pathophysiology behind osteoporosis and other metabolical bone diseases. This article gives a summary of our present knowledge of the normal cell biology of bone and what contributes to its regulation. How this helps the understanding of normal and pathological bone loss is illustrated. It is important to understand bone remodelling in order to interpret measurements of bone mineral density and biochemical markers accurately.

Aged↗

PubMed1998

[Can biochemical markers for bone density be recommended as diagnostic and prognostic tools in osteoporosis?].

Biochemical markers of bone metabolism have potential clinical value in osteoporosis, rheumatic diseases, metabolic bone diseases, and skeletal metastasis. The markers are measured in serum or urine and reflect bone synthesis or bone resorption. Knowledge of the markers' analytical and biological variation, sensitivity, and specificity is necessary to make use of these measurements. This article gives a review of the new bone markers available today: osteocalcin, bone alkaline phosphatase, procollagen peptides, pyridinolines, and telopeptides. Bone markers are clearly useful in research and in epidemiological studies, but routine clinical use is still controversial. We discuss the consequences of making use of bone markers in the diagnostics of osteoporosis, as a prognostic factor of bone loss or fractures, or to monitor therapy. We conclude that we still lack sufficient knowledge to justify use in clinical practice.

Biomarkers↗

PubMed1998

[Estrogen replacement].

Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

Adolescent↗

PubMed1998

[Hormone replacement therapy among Norwegian women. Self-reported use and sales of estrogen preparations].

In order to analyse the use of hormone replacement therapy (HRT) and the predicting factors for its use, two random samples of Norwegian women (30-79 years) were interviewed by the Central Bureau of Statistics in 1994 (n = 565) and in 1996 (n = 470). The extent of use of HRT was compared with statistics for sales of oestrogen in Norway and the Nordic countries. In the age group 45-69 years the use of hormone replacement therapy increased from 16.3% in 1994 to 19.1% in 1996. The proportion of users did not increase with a higher level of education. In addition to information received, and after adjusting for other variables, attitudes towards oestrogen and knowledge about it were the most important contributing factors for using HRT. Sales figures show that the use of systemic oestrogen in Norway has increased more than 280% since 1990. None of the Nordic countries have had a corresponding increase, but the Norwegian figures are still low compared to most other Nordic countries. In 1996 14.5% of Norwegian women (50-79 years) used oestrogen for urogenital disorders. Norwegian women need to be better informed and more knowledgeable to enable them to make conscious choice regarding use of hormone replacement therapy.

Adolescent↗

PubMed1998

The Tromsø Study: body height, body mass index and fractures.

Tall persons suffer more hip fractures than shorter persons, and high body mass index is associated with fewer hip and forearm fractures. We have studied the association between body height, body mass index and all non-vertebral fractures in a large, prospective, population-based study. The middle-aged population of Tromsø, Norway, was invited to surveys in 1979/80, 1986/87 and 1994/95 (The Tromsø Study). Of 16,676 invited to the first two surveys, 12,270 attended both times (74%). Height and weight were measured without shoes at the surveys, and all non-vertebral fractures in the period 1988-1995 were registered (922 persons with fractures) and verified by radiography. The risk of a low-energy fracture was found to be positively associated with increasing body height and with decreasing body mass index. Furthermore, men who had gained weight had a lower risk of hip fractures, and women who had gained weight had a lower risk of fractures in the lower extremities. High body height is thus a risk factor for fractures, and 1 in 4 low-energy fractures among women today might be ascribed to the increase in average stature since the turn of the century. Low body mass index is associated with a higher risk of fractures, but the association is probably too weak to have any clinical relevance in this age category.

Adult↗

PubMed1998

The Tromsø Study: physical activity and the incidence of fractures in a middle-aged population.

We have studied the relation of occupational and recreational physical activity to fractures at different locations. All men born between 1925 and 1959 and all women born between 1930 and 1959 in the city of Tromsø were invited to participate in surveys in 1979-1980 and 1986-1987 (The Tromsø Study). Of 16,676 invited persons, 12,270 (73.6%) attended both surveys. All nonvertebral fractures (n = 1435) sustained from 1988 to 1995 were registered in the only hospital in the area. Average age in the middle of the follow-up period (December 31, 1991) was 47.3 years among men and 4501 years among women, ranging from 32 to 66 years. Fracture incidence increased with age at all locations among women, but it decreased with or was independent of age among men. Low-energetic fractures constituted 74.4% of all fractures among women and 55.2% among men. When stratifying by fracture location, the most physically active persons among those 45 years or older suffered fewer fractures in the weight-bearing skeleton (relative risk [RR] 0.6, confidence interval [CI] 0.4-0.9, age-adjusted), but not in the non-weight-bearing skeleton (RR 1.0, CI 0.7-1.2, age-adjusted) compared with sedentary persons. The relative-risk of a low-energetic fracture in the weight-bearing skeleton among the most physically active middle-aged was 0.3 (CI 0.1-0.7) among men and 0.9 (CI 0.4-1.8) among women compared with the sedentary when adjusted for age, body mass index, body height, tobacco smoking, and alcohol and milk consumption. It seems that the beneficial effect on the skeleton of weight-bearing activity is reflected also in the incidence of fractures at different sites.

Adult↗

PubMed1997

Physical activity and predisposition for hip fractures: a review.

Studies on the association between physical activity and hip fractures are reviewed. All the studies, which comprise four follow-up studies, one nested case-control study and 17 case-control studies, suggest a protective effect of physical activity with regard to hip fractures. The association is strong and consistent with physical activity in leisure, weaker with respect to physical activity at work. The association is present for physical activity from childhood to adult age, and it is consistent in study populations from the USA, Australia, Asia and Northern and Southern Europe, in spite of very different hip fractures incidences in these populations. The magnitude of the association is difficult to assess because of varying criteria for exposure, but to be among the physically active seems to reduce the risk of later hip fracture by up to 50%. It seems that even daily chores, such as climbing stairs and walking, protect against hip fracture.

Accidental Falls↗

PubMed1996

[Osteoporosis. Knowledge and attitudes of the Norwegian population].

In March 1994, a random sample of 1,514 Norwegians aged 16-79 years were interviewed about their knowledge of osteoporosis and their attitudes towards prevention of this disease. About 85% answered correctly that osteoporosis can be prevented, but only 57% knew that it cannot be cured. Women had better knowledge of osteoporosis than men had. Two thirds of the women were positive to the use of long-term hormone replacement therapy to prevent osteoporosis. The majority of women aged 60 years or more preferred walking to other physical activities to prevent the disease. Although the data demonstrated fairly good general knowledge of osteoporosis in the population, the oldest women, those at the highest risk of developing the disease, knew less about osteoporosis than the younger women did.

Adolescent↗

PubMed1996

What do Norwegian women and men know about osteoporosis?

A survey of a random sample of 1514 Norwegian women and men aged 16-79 years was undertaken to investigate knowledge of osteoporosis and attitudes towards methods for preventing this disease. The interviews were carried out by Central Bureau of Statistics of Norway as part of their monthly national poll using a structured questionnaire. Women knew more about osteoporosis than did men (p < 0.001). In both men and women increased knowledge of osteoporosis was correlated to a high level of education. Furthermore it was clearly demonstrated that knowing someone with osteoporosis or suffering from it oneself increased the knowledge of osteoporosis significantly in both women and men. Multiple regression analysis confirmed the univariate analyses, and education was the strongest predictive factor for knowledge. To a hypothetical question as many as two-thirds of the women answered that they would use long-term hormone replacement therapy (HRT) to prevent osteoporosis on the recommendation of their general practitioner. Their attitudes towards the use of estrogen therapy did not show any significant relation to age, but their reluctance towards HRT increased with education (p < 0.001). When asked a question about their preferences regarding the use of physical activity as a means to prevent osteoporosis, older women preferred walking (p < 0.001), whereas younger women wanted more organized athletic activity (p < 0.001). The data demonstrated that there was a high degree of general knowledge of osteoporosis and its consequences in the general population.

Adolescent↗

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↗