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Biomedical subjects

Sara Holmberg

Publications and source records attributed to Sara Holmberg.

9 recordsLinked to original sources

Characterization of mitochondrial ferritin in Drosophila.

Mitochondrial function depends on iron-containing enzymes and proteins, whose maturation requires available iron for biosynthesis of iron-sulfur clusters and heme. Little is known about how mitochondrial iron homeostasis is maintained, although the recent discovery of a mitochondrial ferritin in mammals and plants has uncovered a potential key player in the process. Here, we show that Drosophila melanogaster expresses mitochondrial ferritin from an intron-containing gene. It has high similarity to the mouse and human mitochondrial ferritin sequences and, as in mammals, is expressed mainly in testis. This ferritin contains a putative mitochondrial targeting sequence and an epitope-tagged version localizes to mitochondria in transfected cells. Overexpression of mitochondrial ferritin fails to alter both total-body iron levels and iron that is bound to secretory ferritins. However, the viability of iron-deficient flies is compromised by overexpression of mitochondrial ferritin, suggesting that it may sequester iron at the expense of other important cellular functions. The conservation of mitochondrial ferritin in an insect species underscores the importance of this iron-storage molecule.

Amino Acid Sequence↗

Low back pain comorbidity among male farmers and rural referents: a population-based study.

Farmers report more low back pain (LBP) than rural referents. We have previously demonstrated that the difference in reporting rate cannot be fully explained by known risk factors such as physical work exposures, psychosocial factors and lifestyle. Other etiological factors must be involved. In this cross-sectional population-based study, we investigate LBP comorbidity in terms of coexistent symptoms. A total of 1,013 male farmers, 40-60 years old, and 769 matched rural referents participated in an extensive health survey. Information on causes of primary health care and hospital admissions, symptoms, lifestyle factors, physical work exposures and psychosocial factors were gathered through standardized interviews and questionnaires. In the combined farmer-referent group, the prevalence of LBP was associated with musculoskeletal symptoms other than LBP, chest discomfort, dyspepsia, symptoms from eyes, nose and throat mucous membranes, skin problems, work-related fever attacks, and primary care appointments due to digestive disorders. The associations were independent of age, educational level, smoking habits, body mass index, physical work exposures and psychosocial factors. Presence of both respiratory and digestive disorders doubled the LBP prevalence. Significant associations between LBP and digestive and respiratory disorders were revealed, indicating that LBP and these disease entities may have etiological factors in common.

Agricultural Workers' Diseases↗

Is there an increased risk of knee osteoarthritis among farmers? A population-based case-control study.

OBJECTIVES: Occupational workload is generally considered a to be contributing cause in the development of knee osteoarthritis, in addition to well-known risk factors such as age, female gender, excess weight and previous knee injuries. Farmers have an increased risk of developing hip osteoarthritis, but it is uncertain if farming is influencing the occurrence of knee osteoarthritis. The aim of this population-based case-control study was to investigate the risk of radiographically verified femorotibial osteoarthritis among farmers and those in some other physically demanding occupations. METHODS: A mailed questionnaire inquiring about previous occupations was answered by 778 subjects having X-ray verified osteoarthritis in the femorotibial joint and 695 matched controls. The reply frequency was 89%. Mean age of the participants was 63 years, 43% were male and 57% female. The relationship between knee osteoarthritis and occupation was analysed by multiple logistic regression, with adjustment for a number of variables. RESULTS: Men who had worked for 11-30 years in the building and construction industry had a 3.7-times (95% CI 1.2-11.3) increased risk of knee osteoarthritis. Farm work was not related to an increased risk for men. However, women who had worked for 11-30 years in farming tended to have an increased risk (OR 2.1, 95% CI 1.0-4.5). Forestry, letter-carrying (postal), cleaning and healthcare work was not related to knee osteoarthritis. Excess weight, heredity and previous knee injuries were strong risk factors, whereas smoking showed a negative relationship to knee osteoarthritis. CONCLUSION: Work in building and construction occupations, but not in farming, was associated with an increased risk of knee osteoarthritis.

Adult↗

Osteoarthritis of the hip joint and farm work.

BACKGROUND: Different types of farming and farm work were studied in relation to the occurrence of osteoarthritis of the hip joint in a cohort of farmers. METHODS: A group of 427 farmers with hip joint osteoarthritis were identified together with a matched control group of farmers without hip or knee problems. All were invited to an interview and physical examination. After a dropout of 10%, and removing those who had had predisposing diseases or trauma, the observations for 369 pairs were available for analyses. RESULTS: Farmers with larger dairy and swine confinement operations (sows) had an increased risk of acquiring osteoarthritis of the hip. In a logistic regression multivariate model, those who milked more than 40 cows daily had an increase in risk (OR = 4.5, 95% CI 1.9-11.0) in relation to those who did not work in dairy production. Those who had worked more than 5 hr daily in animal barns over a long period of time also had an increase in risk (OR = 13.3, 95% CI 1.2-145.0) in relation to those who did not work with animals. In another model, those who had large farm areas (>100 ha) had a significantly decreased risk (OR = 0.14, 95% CI 0.05-0.43) in relation to those who had smaller farm areas. CONCLUSIONS: Farmers operating farms with large plant production area and few animal contacts had a significantly lower risk of incurring osteoarthritis of the hip than did farmers in general. The presence of animal production showed a significant positive relationship to the risk of developing hip joint osteoarthritis. Am. J. Ind. Med. 45:202-209, 2004.

Adult↗

Psychosocial factors and low back pain, consultations, and sick leave among farmers and rural referents: a population-based study.

Farmers have more low back pain (LBP) than nonfarmers. In a previous report, we found that differences between farmers and nonfarmers in physical work exposure did not explain the LBP differences. In this report, we tested the hypothesis that psychosocial factors might explain the differences in LBP reporting, medical consultation, and sick leave. A cross-sectional population-based survey of 1,013 middle-aged farmers and 769 matched referents was performed. Data on LBP, consultations, and sick leave during lifetime was obtained along with information on psychosocial, social network, and lifestyle variables. Several of the psychosocial variables were associated with LBP but the difference in LBP prevalence between farmers and nonfarmers could be explained only marginally. Farmers and self-employed referents tended to have lower odds of sick leave because of LBP than employed referents after adjustment for psychosocial factors.

Agricultural Workers' Diseases↗

The impact of physical work exposure on musculoskeletal symptoms among farmers and rural non-farmers.

In order to evaluate the impact of physical work exposure on differences in musculoskeletal symptom reported among Swedish farmers and referents, a cross-sectional, population-based cohort study was performed. Male farmers (N = 1221) and matched non-farmers (N = 1130) were invited to take part a survey in which 76 % participated. The analyses were based on 657 matched pairs. Lifetime incidence of musculoskeletal symptoms, information on work exposure, physical workload and leisure time physical activity were assessed by questionnaire and structured interview. Physical work capacity and muscle strength were measured. Farmers reported more low back and hip problems than the referents. After adjustment for the influence of work exposure factors, farmers still had a significant excess rate of low back and hip symptoms compared to the referents, and a significantly lower rate of neck and shoulder problems. In conclusion, work exposure explained some but not all of the farmer-referent differences in musculoskeletal symptom rates.

Agricultural Workers' Diseases↗

Musculoskeletal symptoms among farmers and non-farmers: a population-based study.

Farming has been considered a high-risk occupation for musculoskeletal disorders. However, documentation of the increased risk is weak except for hip osteoarthritis. 1,013 full-time farmers in nine Swedish municipalities and 769 non-farmers (referents), matched for age, sex, and residential area, participated in the study. Information about medical history, consultations, and sick leave for musculoskeletal disorders was obtained by questionnaire and interview. The farmers reported significantly more symptoms affecting the hands and forearms, low back, and hips than did the non-farmers, and a non-significant trend in the same direction was found for symptoms from the neck, shoulders, and knees. However, the farmers did not seek medical advice more often than the referents, and they reported significantly less sick leave for these problems. Thus, farmers appear to have more musculoskeletal symptoms than do non-farmers.

Adult↗