Correction to: Compressive loading of the murine tibia reveals site-specific micro-scale differences in adaptation and maturation rates of bone

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Prednisolone treatment reduces the osteogenic effects of loading in mice

Glucocorticoid treatment, a major cause of drug-induced osteoporosis and fractures, is widely used to treat inflammatory conditions and diseases. By contrast, mechanical loading increases bone mass and decreases fracture risk. With these relationships in mind, we investigated whether mechanical loading interacts with GC treatment in bone. Three-month-old female C57BL/6 mice were treated with high-dose prednisolone (15 mg/60 day pellets/mouse) or vehicle for two weeks. During the treatment, right tibiae were subjected to short periods of cyclic compressive loading three times weekly, while left tibiae were used as physiologically loaded controls. The bones were analyzed using peripheral quantitative computed tomography, histomorphometry, real-time PCR, three-point bending and Fourier transform infrared micro-spectroscopy. Loading alone increased trabecular volumetric bone mineral density (vBMD), cortical thickness, cortical area, osteoblast-associated gene expression, osteocyte- and osteoclast number, and bone strength. Prednisolone alone decreased cortical area and thickness and osteoblast-associated gene expression. Importantly, prednisolone treatment decreased the load-induced increase in trabecular vBMD by 57% (p < 0.001) and expression of osteoblast-associated genes, while completely abolishing the load-induced increase in cortical area, cortical thickness, number of osteocytes and osteoclasts, and bone strength. When combined, loading and prednisolone decreased the collagen content. In conclusion, high-dose prednisolone treatment strongly inhibits the loading-induced increase in trabecular BMD, and abolishes the loading-induced increase in cortical bone mass. This phenomenon could be due to prednisolone inhibition of osteoblast differentiation and function.

Compressive loading of the murine tibia reveals site-specific micro-scale differences in adaptation and maturation rates of bone

Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels.

INTRODUCTION

Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength. The overall aim was to explore the hypothesis that changes in loading environment result in site-specific adaptations at molecular/micro- and macro-scale in mouse bone.

METHODS

Right tibiae of adult mice were subjected to well-defined cyclic axial loading for 2 weeks; left tibiae were used as physiologically loaded controls. The bones were analyzed with μCT (structure), reference point indentation (material properties), Raman spectroscopy (chemical), and small-angle X-ray scattering (mineral crystallization and structure).

RESULTS

The cranial and caudal sites of tibiae are structurally and biochemically different within control bones. In response to loading, cranial and caudal sites increase in cortical thickness with reduced mineralization (-14 and -3%, p < 0.01, respectively) and crystallinity (-1.4 and -0.3%, p < 0.05, respectively). Along the length of the loaded bones, collagen content becomes more heterogeneous on the caudal site and the mineral/collagen increases distally at both sites.

CONCLUSION

Bone structure and composition are heterogeneous, finely tuned, adaptive, and site-specifically responsive at the micro-scale to maintain optimal function. Manipulation of this heterogeneity may affect bone strength, relative to specific applied loads.

Vitamin D status and bone health in immigrant versus Swedish women during pregnancy and the post-partum period

OBJECTIVE

We evaluated the association between vitamin D status and bone health in pregnant and post-partum immigrant versus Swedish women.

METHODS

We consecutively recruited 41 immigrant and 19 age-matched healthy native Swedish women. Serum 25-hydroxy vitamin D(3) [25(OH)D] and parathyroid hormone (PTH) were analyzed at pregnancy week 12 and 6-12 months postpartum. Dual X-ray absorptiometry (DXA) of the hip and lumbar spine, and peripheral quantitative computed tomography (pQCT) of the radius and tibia were analyzed 6-12 months postpartum.

RESULTS

The mean±SD 25(OH)D in gestational week 12 was 20±11 nmol/L among the immigrants and 60±17 nmol/L among the Swedish women (p<0.001). The postpartum 25(OH)D was 29±18 nmol/L among the immigrants and 53±19 nmol/L among the Swedish women (p=0.003). BMD measured with DXA and pQCT did not differ significantly between groups. The ratio of cortical and trabecular density, a potential sign of osteomalacia, did not differ between groups. There were no significant correlations between 25(OH)D and the bone density measurements.

CONCLUSIONS

Immigrant young women in Sweden are at a high risk of persistent and pronounced 25(OH)D deficiency. However, radiological measures of bone health were not affected by persisting low 25(OH)D. The health consequences of 25(OH)D deficiency should be studied in future studies.

Comparison of acridine orange, acriflavine, and bisbenzimide stains for enumeration of bacteria in clear and humic waters

In highly humic water, acridine orange precipitated with dissolved humic matter, resulting in such bright background fluorescence that no bacteria could be seen. With bisbenzimide staining, a similar precipitate was nonfluorescent but obscured many cells. An acriflavine staining method proved useful and reproducible both in clear and in humic waters. Fading of fluorescence was not a problem, and stained samples could be stored after preparation. The fluorescence of cells stained with acriflavine was weaker than that with acridine orange, making counting extremely small cells slightly more difficult with the former stain.

Physical training preserves bone mineral density in postmenopausal women with forearm fractures and low bone mineral density

One hundred and twelve postmenopausal women with low bone mineral density (BMD) and forearm fractures were randomized to physical training or control group. After one year the total hip BMD was significantly higher in the women in the physical training group. The results indicate a positive effect of physical training on BMD in postmenopausal women with low BMD.

INTRODUCTION

The fivefold increase in hip fracture incidence since 1950 in Sweden may partially be due to an increasingly sedentary lifestyle. Our hypothesis was that physical training can prevent bone loss in postmenopausal women.

METHODS

One hundred and twelve postmenopausal women 45 to 65 years with forearm fractures and T-scores from -1.0 to -3.0 were randomized to either a physical training or control group. Training included three fast 30-minute walks and two sessions of one-hour training per week. Bone mineral density (BMD) was measured in the hip and the lumbar spine at baseline and after one year.

RESULTS

A per protocol analysis was performed, including 48 subjects in the training group and 44 subjects in the control group. The total hip BMD increased in the training group +0.005 g/cm2 (+/-0.018), +0.58%, while it decreased -0.003 g/cm2 (+/-0.019), -0.36%, (p = 0.041) in the control group. No significant effects of physical training were seen in the lumbar spine. A sensitivity intention to treat analysis, including all randomized subjects, showed no significant effect of physical training on BMD at any site.

CONCLUSIONS

The results indicate a small but positive effect of physical exercise on hip BMD in postmenopausal women with low BMD.

New mass value for 7Li

A high-accuracy mass measurement of 7Li was performed with the SMILETRAP Penning-trap mass spectrometer via a cyclotron frequency comparison of 7Li3+ and H2+. A new atomic-mass value of 7Li has been determined to be 7.016 003 425 6(45) u with a relative uncertainty of 0.63 ppb. It has uncovered a discrepancy as large as 14sigma (1.1 microu) deviation relative to the literature value given in the Atomic-Mass Evaluation AME 2003. The importance of the improved and revised 7Li mass value, for calibration purposes in nuclear-charge radii and atomic-mass measurements of the neutron halos 9Li and 11Li, is discussed.

Determination of the (76)Ge double beta decay Q value

The Q value of the (76)Ge double beta decay has been determined by measuring the masses of (76)Ge and (76)Se in a Penning trap using neon- and fluorinelike ions. The obtained masses are 75.921 402 758(96) u and 75.919 213 795(81) u, respectively. The systematic errors of these two determinations are nearly equal, and therefore, the remaining systematic uncertainty of the Q value is drastically reduced. A Q value of 2 039.006(50) keV was obtained improving the accuracy of the accepted value by a factor of 6.

Serum thymidine kinase in congenital dyserythropoietic anaemia type III

Serum thymidine kinase (TK) was determined in a family with congenital dyserythropoietic anaemia type III (CDA, type III). 20 patients and 10 of their healthy siblings were investigated. Elevated TK was found in all 20 patients (median 56.2 U) but their healthy siblings had normal values (median 2.65 U). We suggest that determination of TK should be used for discrimination between healthy siblings and individuals affected by CDA type III when bone marrow examination is not suitable.

Intravascular haemolysis and increased prevalence of myeloma and monoclonal gammopathy in congenital dyserythropoietic anaemia, type III

A family with congenital dyserythropoietic anaemia type III was studied. Twenty patients and 10 of their healthy siblings were clinically examined and questioned about their medical history. Blood sampling and bone marrow aspirations were also performed. Forty-five percent of the patients reported symptoms of anaemia and 35% regularly felt weakness, fatigue, or headache. However, the majority of the patients regarded themselves as healthy. The bone marrow showed a uniform picture of erythroid hyperplasia with multinuclear erythroblasts and gigantoblasts with up to 12 nuclei. There was laboratory evidence of intravascular haemolysis and mild anaemia. We also observed a high prevalence of monoclonal gammopathy of undetermined significance (3 cases) and myeloma (1 case) among the patients.

Familial malignant blood disease in the country of Jämtland, Sweden

In a material of 942 patients with malignant hematological disease, encompassing all diagnosed cases in the country of Jämtland in Sweden during a 22-yr period, 36 families with multiple cases of such disease were found. Approximately 5% of the patients have at least one close relative who also suffers from a malignant hematological disease. An especially strong familial occurrence was found in the group of chronic lymphoproliferative diseases and it is concluded that this tendency comprises all diseases in the group, i.e. chronic lymphocytic leukemia, multiple myeloma and malignant lymphoma. In some families several cases of acute leukemia were present, and suggestions concerning immunological disturbances are made. In the group of chronic myeloproliferative diseases familial factors do not seem to play an important part, with the possible exception of polycythemia vera. Both heredity and common environmental agents must be considered as possible etiologic factors.

Studies of drug-treated diabetes in the county of Jämtland, Sweden, based on prescription of insulin and oral antidiabetic drugs

Epidemiological data on drug-treated diabetes mellitus was obtained by analyzing prescriptions of insulin and oral antidiabetics in the county of Jämtland Sweden. During a 12-year period, from 1971 to 1982, the prevalence of diabetes increased from 1.5% to 2.2%, while there was no significant change in the annual incidence of around 2.7/1000 inhabitants. Women displayed a considerable higher prevalence and incidence than men in the over 70 age-group, while in the 50 - 69 age-group there was a male dominance. A significant change in the prescription pattern with an increased use of insulin and decreased use of oral antidiabetics was observed during the period. More patients were started on oral antidiabetics during the first part of the year than during the latter.