| 1. |
- Ivaska, KK, et al.
(författare)
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Identification of novel proteolytic forms of osteocalcin in human urine
- 2003
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Ingår i: Biochemical and Biophysical Research Communications. - 1090-2104. ; 306:4, s. 973-980
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we report the isolation and characterization of osteocalcin in human urine using mass spectrometry and N-terminal sequencing. Multiple proteolytic forms of osteocalcin were found, which consisted of 16-27 residues from the middle region of the molecule. Several fragments had residue Gly7 at the N-terminus and the most predominant was fragment 7-31. Additional fragments starting from residue Asp14 were detected in the samples of children and young adults. Immunochemical detection of urine osteocalcin fragments had a statistically significant negative correlation to bone mineral density in evaluation of urine samples from 75-year-old women. Thus, the measurement of osteocalcin fragments in urine may have potential applications in diagnostics related to disorders of bone metabolism.
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| 2. |
- Kaastad, T S, et al.
(författare)
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Effects of clodronate on cortical and trabecular bone in ovariectomized rats on a low calcium diet
- 1997
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 61:2, s. 158-164
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the contribution of a low calcium diet to the cortical and trabecular osteoporosis seen in ovariectomized rats after 7 weeks on a low calcium diet and to investigate the effects of the bisphosphonate clodronate on this development of osteoporosis. Thirty-six mature, female Wistar rats were randomized into four groups: Ovx-B (bisphosphonate) and Ovx-C (control) were ovariectomized, and Sham-Ca (low calcium) and Sham+Ca (normal calcium) were sham operated. The first three groups were fed a low calcium diet (0.01%) and Sham+Ca normal rat chow (Ca 1.1%). The Ovx-B received 10 mg/kg s.c. clodronate daily for nine weeks, and Ovx-C, Sham-Ca, and Sham+Ca received the same volumes of saline. Bone mineral turnover measured as 85Sr-uptake was increased in all low calcium groups compared to Sham+Ca. The Sham+Ca femora had higher dry weight and ash weight than the other groups, and Ovx-C had higher dry weight compared with Ovx-B and Sham-Ca. Calcium content was lower in both Ovx groups compared to both Sham groups. Magnesium was lower in all groups compared to Sham+Ca and higher in Ovx-B compared with Ovx-C. In the femoral shaft, Sham+Ca had significantly higher ultimate bending moment, energy absorption, and deflection compared to the other three groups. Ultimate bending moment was higher in Sham-Ca than in Ovx-C. Stiffness was increased in both Sham+Ca and Ovx-B compared to Ovx-C. The maximum stress in the femoral midshaft was higher in Sham+Ca than in the other groups, and higher in Ovx-B than in Ovx-C. Histomorphometry showed increased medullary area in all low calcium groups compared to Sham+Ca and larger cortical area in Sham+Ca and Ovx-B compared to Ovx-C. Compared to Sham+Ca the trabecular bone volume was decreased to 30% in Sham-Ca and to 9% in Ovx-C, but was unchanged in Ovx-B. The low calcium diet generally increased bone mineral turnover and reduced the tibial bone volume. Femoral changes led to a reduction of cortical fracture strength and maximal stress. Ovariectomy in addition to a low calcium diet reduced femoral strength even more. Daily injections of clodronate to ovariectomized rats on a low calcium diet increased femoral shaft stiffness and maximum stress, and clodronate preserved both trabecular and cortical tibial bone volume completely.
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| 3. |
- Blomqvist, J E, et al.
(författare)
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Importance of bone graft quality for implant integration after maxillary sinus reconstruction
- 1998
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Ingår i: Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology. - 1079-2104. ; 86:3, s. 268-274
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to determine whether bone quality, as assessed by osteometry and histologic parameters, can be used to predict implant integration in conjunction with maxillary sinus reconstruction. STUDY DESIGN: Twelve patients with severely atrophied maxillary alveolar processes were treated through use of a two-stage surgical reconstructive strategy with implant placement 4 months after bone grafting. Bone biopsy specimens taken from the iliac crest peroperatively and from the sinus inlay sites 1, 2, 4, 6, or 12 months postoperatively were analyzed by light microscopy and osteomorphometry. Bone mineral content was measured by osteometry. RESULTS: Osteometric and osteomorphometric data (trabecular bone volume [%], assessment of chromatin staining, and an osteocyte index) registered for the biopsy specimens were not statistically correlated with implant failure. CONCLUSIONS: Prognostic evaluation of implant survival is difficult. The tested methods did not contribute to the improvement of guidelines for the clinical handling of these patients.
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| 4. |
- Boonen, S., et al.
(författare)
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Balloon kyphoplasty and vertebroplasty in the management of vertebral compression fractures
- 2011
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 22:12, s. 2915-2934
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Forskningsöversikt (refereegranskat)abstract
- Vertebral compression fractures (VCFs) are the most prevalent fractures in osteoporotic patients. The classical conservative management of these fractures is through rest, pain medication, bracing and muscle relaxants. The aim of this paper is to review prospective controlled studies comparing the efficacy and safety of minimally invasive techniques for vertebral augmentation, vertebroplasty (VP) and balloon kyphoplasty (BKP), versus non-surgical management (NSM). The Fracture Working Group of the International Osteoporosis Foundation conducted a literature search and developed a review paper on VP and BKP. The results presented for the direct management of osteoporotic VCFs focused on clinical outcomes of these three different procedures, including reduction in pain, improvement of function and mobility, vertebral height restoration and decrease in spinal curvature (kyphosis). Overall, VP and BKP are generally safe procedures that provide quicker pain relief, mobility recovery and in some cases vertebral height restoration than conventional conservative medical treatment, at least in the short term. However, the long-term benefits and safety in terms of risk of subsequent vertebral fractures have not been clearly demonstrated and further prospective randomized studies are needed with standards for reporting. Referral physicians should be aware of VP/BKP and their potential to reduce the health impairment of patients with VCFs. However, VP and BKP are not substitutes for appropriate evaluation and treatment of osteoporosis to reduce the risk of future fractures.
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| 5. |
- Kaastad, T S, et al.
(författare)
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Effect of intensive training on lower leg structural strength: an in vivo study in ovariectomized rats
- 1997
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Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 1600-0838 .- 0905-7188. ; 7:4, s. 220-225
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the effect of training on the in vivo tibial structural strength during the development of post-ovariectomy osteoporosis. Seventeen mature Wistar rats (215 g) were ovariectomized and randomized into two groups. The sedentary control group was kept cage confined, while 3 days postoperatively the trained group started treadmill running with high intensity for 1 h 5 days a week. All were given a low calcium diet (Ca 0.01%). After 8 weeks the animals were anaesthetized and the right lower legs fractured during muscle contraction in three-point ventral bending. The left legs were fractured at the same level after removal of all soft tissues. Histomorphometry of the meta- and diaphysis of the distal tibiae was performed. Weight-gain was higher in sedentary (108 g) than in trained (61 g) rats (P<0.0001). There were no significant differences in mechanical results between the groups at in vivo or in vitro fracture. Correcting for weight-gain differences did not change these results. Histomorphometry showed no differences between the groups. Corticosterone was higher in trained than in sedentary rats (P<0.02), and corticosterone may have had a negative influence both on muscle and bone. The study could not show an effect of high intensity training in the early phase after ovariectomy on in vivo or in vitro fracture strength.
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| 6. |
- Kaastad, T S, et al.
(författare)
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Vitamin D deficiency and ovariectomy reduced the strength of the femoral neck in rats
- 2001
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 69:2, s. 102-108
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Tidskriftsartikel (refereegranskat)abstract
- Vitamin D (vit D) deficiency is common in the elderly, and the aim of this study was to investigate whether vit D deprivation in ovariectomized (ovx) and normal rats would reduce fracture strength. Forty mature female Wistar rats were randomized into four groups: two were ovariectomized (ovx) and two were sham-operated (sham). One ovx and one sham group were fed a vit D-deficient diet (Ovx-D and Sham-D), and the control groups were fed normal rat chow (Ovx and Sham) for 12 weeks. Vit D deficiency was substantiated after 12 weeks by undetectable serum concentrations of 25OHD in the Sham-D and Ovx-D groups. 85Sr activity was lower in Sham-D than in the other groups (P < 0.005). Tibial and femoral weights and lengths showed no differences. Distal tibial trabecular bone volume was reduced in both ovx groups compare with sham (P < 0.005). Bone mineral density (BMD) was higher in sham than in Sham-D and both ovx groups (P < 0.005). Femoral area moment of inertia increased and ultimate stress decreased in Ovx-D compared with ovx (P < 0.05). Other biomechanical properties of the femoral shafts did not differ significantly. The femoral neck was significantly weaker in Ovx-D than in the other groups. In conclusion, ovx decreased tibial trabecular bone volume and both ovx and vit D depletion reduced femoral BMD in rats. Vit D depletion reduced the ultimate stress in the femoral shaft, and the combined depletion of estrogen and vit D significantly reduced the fracture strength in the femoral neck. This fits well with clinical evidence of how postmenopausal status combined with vit D deficiency lead to an increased risk of hip fractures, making this animal model a possible tool for investigating measures to prevent such fractures.
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| 7. |
- Kakonen, S M, et al.
(författare)
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Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum
- 2000
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Ingår i: Clinical Chemistry. - 0009-9147. ; 46:3, s. 332-337
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Circulating human osteocalcin (hOC) has been used as a marker of bone formation. Our aim was to validate three immunofluorometric assays (IFMAs), measuring different forms of hOC. METHODS: The two-site IFMAs were based on previously characterized monoclonal antibodies. Assay 2 recognized intact hOC, assays 4 and 9 measured the NH(2)-terminal mid-fragment and the intact hOC. In addition, assay 9 required hOC to be gamma-carboxylated. RESULTS: A 76-79% increase of serum immunoreactive hOC was found in the postmenopausal group compared with the premenopausal group with all IFMAs. With EDTA-plasma samples, the observed increases were lower (49-65%). The hOC concentration in the postmenopausal group receiving hormone replacement therapy was 42-44% lower than that in the postmenopausal control group in both serum and EDTA-plasma samples. The depressed carboxylation in warfarin-treated patients was accompanied by lower results in assay 9. The ratio of assay 9 to assay 4 totally discriminated the warfarin-treated patients from the controls. Assay 9 showed the smallest decreases in measured hOC after storage of serum or plasma for 4 weeks at 4 degrees C, followed by assay 4 and assay 2. Results from the last assay were <17% of their initial values after 4 weeks of storage. No diurnal variation was observed with assay 9 as opposed to the two other IFMAs. CONCLUSION: The three assays with their distinct specificity profiles (intact vs fragmented and carboxylated vs decarboxylated hOC) may provide valuable tools for investigating the significance of different hOC forms in various bone-related diseases.
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| 8. |
- Karlsson, Magnus, et al.
(författare)
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Changes of bone mineral mass and soft tissue composition after hip fracture
- 1996
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Ingår i: Bone. - 1873-2763. ; 18:1, s. 19-22
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this prospective longitudinal study was to measure prospectively the bone mineral density (BMD) and anthropometric variables after a hip fracture. In particular, we studied changes in the BMD in both the injured and uninjured hips, and examined if the postoperative mortality rate and complications, including pseudarthrosis of the fracture and late segmental collapse of the head of the femur, could be predicted by early bone mass measurements. The bone mineral density and the body composition were measured with dual energy X-ray absorptiometry in 102 consecutive hip fracture patients, 31 men and 71 women, with a mean age of 74 and 79 years, respectively. All cases were operated on within 3 days. The measurements were undertaken within 10 days after the fracture, after 4 and after 12 months. The BMD of the hip fracture cases decreased, especially in the lower extremities where the patients lost 7%, during the first year after the fracture. The patients also lost lean body mass (5%) but gained fat (11%) during the same period. They lost significantly more bone mass in the fractured hip than in the uninjured hip (p < 0.05). No difference was found between those patients who survived and those who died within 2 years after their hip fracture in neither the initial measurement nor in the follow-up measurements. Also, we found no difference between those patients whose hip fracture healed and those who developed late segmental collapse or pseudarthrosis. In conclusion, osteoporotic hip fracture cases lose bone mass at an increased rate, especially in the fractured hip. Also, their soft tissue composition changes, gaining fat while losing muscle mass. Furthermore, it seems that early bone mineral measurements cannot predict postoperative failures or postoperative mortality.
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| 9. |
- Karlsson, Magnus K., et al.
(författare)
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Bone mineral normative data in Malmö, Sweden : Comparison with reference data and hip fracture incidence in other ethnic groups
- 1993
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 0001-6470. ; 64:2, s. 168-172
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Tidskriftsartikel (refereegranskat)abstract
- The bone mineral mass was measured in 324 residents of the city of Malmö Sweden, by dual energy roentgen absorptiometry (DEXA) using the Lunar DPX equipment - total body, hip, and lumbar vertebrae. the bone mineral content of the wrist was also measured with single photon absorptiometry (SPA) in 88 of the individuals. Weight, height, and vertebral height, as well as body fat, lean body mass, menarcheal age, menopausal age, and hand grip strength were determined. Measurements were compared with reference bone mineral content values from the United States, Japan, and France - also hip fracture incidence was compared. All bone mineral values decreased with age. A good correlation was found between the DEXA technique of total body bone mineral and the forearm SPA values. the bone mineral content was correlated with lean body mass and weight. the Malmö bone mineral content was on the same level as in the United States, but higher than in Japan and France. the comparatively high risk of fragility fractures in the Scandinavian countries compared with most other settings cannot be explained by low bone mass.
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| 10. |
- Karlsson, Magnus K., et al.
(författare)
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The ankle fracture as an index of future fracture risk : A 25-40 year follow-up of 1063 cases
- 1993
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 0001-6470. ; 64:4, s. 482-484
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Tidskriftsartikel (refereegranskat)abstract
- In 1992 a retrospective case control study was performed, based on all patients with ankle fractures (n 1063) treated at the Department of Orthopedics in Malmö Sweden, between 1950-1951 and 1961-1965. As all radiographic examinations have been saved in Malmö we were able to study all subsequent fractures that this group had sustained. 260 patients from 1961-1965 who were still living in Malmö today were also compared with an age-and gender-matched control group regarding the location and type of subsequent fractures. the group with former ankle fractures continued to have a two-fold increased incidence of all sorts of fractures. the same result was found when looking at the upper and lower extremities separately. However, the risk of sustaining new fractures in the once-fractured extremity was not increased compared to the uninjured side.
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