Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources
PubMed2003

Structuring parameters for assessment of bone quality using a morphological filter and star volume analysis: structuring property in the cancellous bone of the human femoral head.

This study examines structuring parameters for the assessment of bone quality based on the relationship of bone strength to the trabecular structure or bone mineral density (BMD). Thirty-nine human cancellous bone blocks sampled from resected Ward's triangle area were investigated. The trabecular bone pattern of each bone block was binarized into its corresponding trabecular skeletal pattern using computed radiography with a morphological filter. Every binarized trabecular skeletal pattern was quantified to find the trabecular skeletal pixel percentage (SkP = volume parameter of trabecular skeletal signal component) and skeletal star volume (Vt = connection parameter of trabecular skeletal structure). After BMD and elasticity for each bone block was measured by dual X-ray absorptiometry and the breaking test, the correlations to SkP and Vt were determined. In addition, an attempt was made to detect changes of the trabecular structure in the Ward's triangle area of the femoral head after patients had received treatment for osteoporosis. This evaluation used the structuring parameters SkP and Vt. The results showed that the larger the BMD value, the greater the elasticity, although some samples with similar BMD values had considerably different elasticities. With increased Vt values the trabecular skeletal pattern that had horizontal skeletal elements orientated perpendicular to the loading direction showed higher elasticity. No correlation between SkP and either elasticity or BMD was observed in either the subset (sequential images of morphological filter) or sumset images (combined with subset images). On the other hand, the correlation coefficient between Vt and elasticity was similar to that between BMD and elasticity for subset image ( n = 6). For sumset images (3-6 and 4-7), the correlation coefficient of Vt was equal or higher than that of BMD and the connectivity of the trabecular skeletal structure was more closely linked to bone strength as compared to BMD. Therefore, it was concluded that because no high correlation could be detected between Vt and BMD, BMD and the connectivity of trabeculae are independently related to bone strength. In addition, this method was used to evaluate patients after treatment for osteoporosis, and noticeable changes were seen in the bone trabecular skeletal structure in the Ward's triangle area of the femoral head. In reference to these clinical images, variations in SkP and Vt were quantitatively assessed. These results suggest that the SkP and Vt obtained using computed radiography, morphological filter, and star volume analysis are useful structuring parameters for the assessment of bone quality.

Aged↗
PubMed2004

Bone transport with frozen devitalized bone: an experimental study using rabbits and a clinical application.

We evaluated the feasibility of bone transport with frozen devitalized bone in the tibia of 20 adult female rabbits. A 1.5-cm segmental defect was created, followed by proximal tibial transverse osteotomy to remove a 2.5-cm segment to be transported after devitalization with liquid nitrogen. The proximal and distal tibia and the devitalized autogenous bone each were fixed with two half-pins. After 2 weeks, transport of the devitalized segment was initiated at 1 mm/day. In a control group, callus formed at proximal and distal osteotomy sites, and distracted callus gradually maturated. The docking site fused and the medullary canal reappeared by 8 weeks after completing distraction. In the frozen-bone group, bone formation proceeded from the proximal tibial end, and the distraction callus slowly matured. The transported segment remained nonviable until revascularization proceeded from its periphery, evident 8 weeks after completion of distraction. Docking sites fused well without infection at pin sites. There was no sign of infection around the pin sites of the devitalized bone. We finally describe similar successful treatment of a 13-year-old girl with tibial deformity resulting from osteofibrous dysplasia who was treated successfully with this procedure. Therefore, bone transport using frozen devitalized bone can regenerate living bone. This experimental model represents the development of a new reconstruction technique of bone transport with devitalized bone.

Adolescent↗
PubMed1987

Bone mass, bone structure and vertebral fractures in osteoporotic patients.

The clinical severity of bone disease was studied in 44 post-menopausal osteoporotic women. Spinal x-rays were assessed and compared to objective measurements of bone mass and bone structure; forearm bone mineral content (BMCarm) by single photon absorptiometry, total body bone mineral content (TBBM), and spinal bone mineral content (BMCspine) by dual photon absorptiometry, and corrected cortical width (C Cor W), trabecular bone volume (TBV), and indices of trabecular microstructure by iliac crest biopsy. For comparison data of BMCarm, TBBM and BMCspine in 25 post-menopausal normals are shown. The results showed a reduction in amount of both cortical and trabecular bone in the fracture patients compared to normals. A subdivision of the fracture patients into two groups constituting 26 patients with wedge fractures alone and 18 patients with compression (+wedge) fractures showed that the latter group had a further predominantly trabecular bone loss and a further deteriorated trabecular microstructure. On an individual basis no agreement between clinical severity of bone disease and amount and structure of bone could be demonstrated.

Aged↗
PubMed1988

Chondrogenesis and osteogenesis of bone marrow-derived cells by bone-inductive factor.

Rat bone marrow cells were intraperitoneally implanted within a diffusion chamber with a decalcified bone matrix or a 4 M guanidine hydrochloride extracted matrix (G-res) as control. The chamber was harvested after 28 days and soft X-ray photography, histological examination, determination of alkaline phosphatase activity and calcium content were performed. With the decalcified bone matrix, cartilage and bone formation was observed and both alkaline phosphatase activity and calcium content were significantly higher than those in control chambers. Each chromatographic fraction on Sephacryl S-200 of the 4 M guanidine hydrochloride extract (G-ext) from the decalcified bone matrix was reconstituted with G-res and implanted either subcutaneously or intraperitoneally within a diffusion chamber with marrow cells. Intrachamber or subcutaneous cartilage and bone formation was detected by only one chromatographic fraction. When marrow-derived fibroblast-like cells were implanted intraperitoneally within a diffusion chamber with a decalcified bone matrix, cartilage and bone formation was detected, which was not the case with G-res. These results suggest that a certain factor, probably bone morphogenetic protein, which induces ectopic bone formation, allows marrow cells to differentiate into bone and cartilage tissues and there may exist so-called "inducible osteoprogenitor cells" in the marrow-derived fibroblast-like cell preparation.

Animals↗
PubMed1992

Trabecular bone pattern factor--a new parameter for simple quantification of bone microarchitecture.

The stability of trabecular bone depends not only on the amount of bone tissue, but also on the three-dimensional orientation and connectedness of trabeculae, which is summarized as trabecular microarchitecture. In previous studies we could demonstrate that in three-dimensional bone tissue the relation of trabecular plates to rods is reflected in the ratio of concave to convex surfaces of the bone pattern in two-dimensional bone sections. For the quantification of the connectedness of these bone patterns we developed a new histomorphometric parameter called Trabecular Bone Pattern factor (TBPf). The basic idea is that the connectedness of structures can be described by the relation of convex to concave surfaces. A lot of concave surfaces represent a well connected spongy lattice, whereas a lot of convex surfaces indicate a badly connected trabecular lattice in two-dimensional sections. By means of an automatic image analysis system we measure trabecular bone area (A1) and perimeter (P1). A second measurement of these two parameters (now A2 and P2) is done after a simulated dilatation of trabeculae on the screen. This dilatation results in a characteristic change of bone area and perimeter depending on the relation of convex to concave surfaces. TBPf is defined as a quotient of the difference of the first and the second measurement: TBPf = (P1 - P2)/(A1 - A2). First measurements of TBPf in 192 iliac crest bone biopsies of autopsy cases show that there is not only age-related loss of bone volume, but also a decrease of trabecular connectedness. By means of TBPf we can demonstrate a significant difference in the age-related loss of trabecular connectivity between male and female individuals.

Autoanalysis↗
PubMed2005

Volumetric spatial decomposition of trabecular bone into rods and plates--a new method for local bone morphometry.

Bone microarchitecture is believed to play a key role in determining bone quality. We therefore present a new method for the volumetric spatial decomposition of trabecular bone samples into its basic elements (rods and plates). This new method is a framework for the element based description of bone microarchitecture. First, the newly developed algorithm was validated on computer-generated models. Then, it was applied to 328 human trabecular bone samples harvested from 70 donors at five different anatomical sites (calcaneus, femoral head, iliac crest, lumbar spine 2 and 4), which were previously scanned by microcomputed tomography. Standard three-dimensional morphometric algorithms were used to analyze the trabeculae on an individual basis with respect to their volume, surface, and thickness. The results were statistically compared for the five sites. In this study, it was possible for the first time to spatially decompose trabecular bone structures in its volumetric elements; rods and plates. The size of the largest element in the structures showed significant differences for the five compared sites. In samples from femoral head, we found that basically one "major element" was spanning through the whole structure whereas in lumbar spine and calcaneus, smaller elements dominate. From this, we suggest that the strength of strong, dense plate-like structures is determined by the major elements whereas in looser rod-like structures the strength is given by the arrangement, quality, and shape of a whole set of elements. Furthermore, we found that globally determined structural indices such as the mean curvature of the bone surface ( ) or related to this the structure model index (SMI) are almost exclusively explained by the arrangement of the plates. This also suggests that rods hold independent information characterizing trabecular bone quality, especially in the spine. These findings may improve the understanding of the site-specific role of bone microarchitecture in determining bone quality and in future studies the competence of bone.

Adult↗
PubMed2006

Evidence for reduced bone formation surface relative to bone resorption surface in female femoral fragility fracture patients.

Fragility fractures, including neck of femur fractures, result from reductions in the amount, quality and architecture of bone. The aim of this study was to compare the cancellous bone structure, and static indices of bone turnover, in female patients, who had sustained fragility fracture at the femoral neck, with age-matched females without fragility fracture. Bone samples were taken from the intertrochanteric region of the proximal femur of female patients undergoing hip arthroplasty surgery for a subcapital fragility fracture of the femoral neck (#NOF) or from age-matched female control individuals at routine autopsy. Contiguous bone samples were analyzed for undecalcified histomorphometry and for mRNA expression. The histomorphometric data, which were normally distributed, indicated no difference between the mean values for any of the structural parameters in control and fracture samples. In particular, the bone volume (BV/TV) values were not different and did not change significantly with age in these cohorts of individuals aged >65 years. The static indices of bone turnover, eroded surface (ES/BS) and osteoid surface (OS/BS), were positively correlated with age in the >65-year-old control group (p < 0.055 and p < 0.03, respectively). The median values for these indices were not different between the fracture and control groups. However, both the median and the range of OS/BS values were increased for >65-year-old controls compared with a group of younger females aged <65 years, suggesting an increase in bone formation surface in older females in the proximal femur after 65 years of age. When the data were further interrogated, a reduction in the percentage osteoid surface to eroded surface quotient (OS/ES) was found for the fracture group compared with the age-matched control group suggesting a reduced adaptive modeling drift capability in the fracture group. In contiguous bone samples, increased median values for receptor activator of nuclear factor kappa beta (RANK) and interleukin-6 (IL-6) mRNA expression were observed in the fracture group. Study of cultured human osteoblasts showed that recombinant human IL-6 (rhIL-6) inhibited osteoblast differentiation, as measured by an increase in the immature osteoblast marker, STRO-1 and concomitantly decreased expression of the osteoblast maturation marker, alkaline phosphatase. Importantly, cells cultured in the presence of IL-6 showed significantly less mineral deposition in vitro compared with control cultures. These data suggest that perturbations in bone formation surface, relative to resorption surface, are potentially important in producing bone in the proximal femur with increased propensity to fracture.

Aged↗
PubMed2004

Markers of bone remodeling predict rate of bone loss in multiple sclerosis patients treated with low dose glucocorticoids.

BACKGROUND: The aim of this study was to evaluate the clinical value of markers of bone remodeling in assessment of rate of bone loss in patients with multiple sclerosis (MS) long term treated with low dose glucocorticoids. METHODS: The study involved 70 patients with MS. Motor function of the patients was evaluated using the Kurtzke Expanded Disability Status Scale (KEDSS). Bone mineral density (BMD) was determined at the lumbar spine and proximal femur at baseline and after 1.8 +/- 0.8 years. Bone remodeling was assessed using circulating concentrations of type 1 collagen cross-linked C-telopeptide (beta CTX), aminoterminal propeptide of type I procollagen, and N-MID osteocalcin (OC). A control group of 140 age-matched healthy subjects was used to compare bone-turnover markers. RESULTS: The plasma CTX concentration was the most significant parameter of bone remodeling which correlated with the rate of bone loss and with the KEDSS. The rate of bone loss at the proximal femur was not significantly different between tertiles of plasma OC concentrations. CONCLUSION: In physically active patients with MS treated with low-dose GC, the bone-turnover markers were not different from controls. Patients having plasma CTX but markers of bone formation higher as compared to controls were confirmed 2 years later as bone losers.

Adult↗
PubMed2004

Nanoindentation and whole-bone bending estimates of material properties in bones from the senescence accelerated mouse SAMP6.

The senescence accelerated mouse, strain P6 (SAMP6) has been described as a model of senile osteoporosis. Recent results from whole-bone bending tests indicate that, despite having increased moments of inertia, SAMP6 long bones are weak and brittle compared to SAMR1 controls. In the current study we determined material properties of cortical bone from SAMP6 and SAMR1 femora and tibiae by two methods-nanoindentation and whole-bone bending tests combined with simple beam theory. We hypothesized that: (1) SAMP6 mice have reduced cortical bone material properties compared to SAMR1 controls; and (2) modulus estimated from whole-bone bending tests correlates well with modulus determined by nanoindentation. Results from nanoindentation indicated that modulus and hardness are approximately 10% higher in SAMP6 mice compared to SAMR1 controls (p<0.001), a finding consistent with slightly higher mineralization in SAMP6 bones. Despite their superior elastic and hardness properties, the bending failure properties of SAMP6 bones were markedly inferior--ultimate stress and toughness were reduced by 40% and 60%, respectively (p<0.001). Comparisons between the two testing methods for determining modulus showed poor agreement. Modulus estimated from whole-bone bending tests was not correlated with modulus determined by nanoindentation (p=0.054; r2=0.03) and the absolute values differed by a factor of five between the two methods (bending [wet], 6GPa; nanoindentation [dry], 31GPa). Moreover, relative differences between groups were inconsistent between the two methods. We conclude: (1) cortical bone from the SAMP6 mouse has increased modulus and hardness but poor material strength and toughness, which underscores the relevance of the SAMP6 mouse for studies of skeletal fragility, and (2) values of elastic modulus of bone tissue estimated using simple beam theory and bending tests of mouse femora and tibiae are inaccurate and should be interpreted with caution.

Aging↗
PubMed2002

Different distributions of human bone alkaline phosphatase isoforms in serum and bone tissue extracts.

BACKGROUND: In vitro, bone alkaline phosphatase (BALP) is released from the osteoblast membrane with its glycosylphosphatidylinositol (GPI) anchor still attached (i.e., in an anchor-intact form); however, in vivo, BALP circulates as a variable mixture of anchorless isoforms, which can be identified by high-performance liquid chromatography (HPLC). Previous studies have shown that the relative abundance of these BALP isoforms in serum may be clinically useful for the diagnosis and management of metabolic bone disease. METHODS: In the current studies, we describe a method for the determination of anchorless BALP isoforms in extracts of bone and we present novel data on the conversion of anchor-intact to anchorless BALP by incubation with endogenous circulating GPI-specific phospholipase D (GPI-PLD). RESULTS: A 72-h extraction with 0.1% Triton X-100 released approximately 90% of the BALP activity from powdered bone. An average of 19% of this activity was anchorless, but essentially all of the activity could be converted to the anchorless form by incubation with partially purified GPI-PLD from human serum. Using HPLC, we detected four BALP isoforms (B/I, B1x, B1, and B2) in these GPI-PLD-treated extracts of bone. An additional BALP fraction was also detected in the samples during the initial phase of GPI-PLD treatment. CONCLUSIONS: The abundance of the BALP isoforms differed between bone and serum, particularly for the B/I isoform, which comprised, on average, 18% of the BALP in GPI-PLD-treated extracts of healthy bone tissue, but only 6% of the total BALP activity in serum from healthy individuals. Based on our recent finding of differences in the number of sialic acid residues between the BALP isoforms, we hypothesize that this difference between BALP isoforms in serum and extracts of bone is due to the different patterns of glycosylation, which results in different biological half-lives in the circulation. A preliminary application of our method to the extraction of BALP isoforms from a small number of human bone samples suggests that the method should be useful for studies of human skeletal site-specific and metabolic bone disease-specific differences in the amounts and distributions of the BALP isoforms in bone.

Adult↗
PubMed1998

Restoration of small bone defects at craniotomy using autologous bone dust and fibrin glue.

BACKGROUND: Bone gaps or burr holes often result in small but undesirable scalp or skin depressions after craniotomy. Whereas a number of reports have discussed cranioplasties to avoid large bone defects, little has been written about the problem of small bone defects which, despite their minor size, could result in bothersome cosmetic problems. METHODS: This study was designed to assess a simple method to repair burr hole defects and bridge bone gaps with autologous bone dust and fibrin glue. Bone dust was collected when burr holes were created or craniectomy was performed. After replacement of the bone flap, the burr holes or bone gap were filled with a mixture of bone dust and fibrin glue. RESULTS AND CONCLUSIONS: The mixture of bone dust and fibrin glue was easily shaped to fit bone defects, resulting in favorable cosmetic outcomes 1 to 5 years after operation.

Bone and Bones↗
PubMed1996

[The pisiform bone: sesamoid or carpal bone?].

In man, the pisiform bone occupies an unusual place among the carpal bones. It is situated in an anterior plane to the other bones, sheathed within the tendon of the flexor carpi ulnaris, and ossifying almost four years the last of the carpal bones. Many theories have tried to explain the presence of this "exceptional" bone: the first theory, proposed by Flower and Mivart, suggested the possibility that this bone could be a sesamoid. The second theory supposes a polydactyl hand, assuming that polydactyly preceded pentadactyly; the pisiform would then be a post-minimus vestigial bone according to Bardeleben. Finally, Gegenbauer and Gillies, proposed a primary pentadactyl hand in which the carpus would be composed of three proximal elements, generally two central, and five distal. The pisiform would either be a derivative of the central series, or a distinct element in the carpus. This last theory appears to be the most likely. The primary carpus would therefore have consisted of 12 bones arranged in 3 distinct rows, a proximal row of 3 bones, a central row of 4 bones, and a distal row of 5 bones. According to this theory, the most ulnar of the central would have been displaced to the medial limit of the carpus, to become the pisiform.

Animals↗
PubMed2002

Vitamin K2 (menatetrenone) inhibits bone loss induced by prednisolone partly through enhancement of bone formation in rats.

Vitamin K(2) (K(2), menatetrenone) has been reported to enhance bone formation and inhibit bone resorption in vitro. However, there is no evidence that K(2) enhances bone formation in vivo. The aim of this study was to characterize the effect of K(2) on bone formation in vivo. We carried out two experiments using a prednisolone (pred)-induced bone loss model in male (10-week-old) Fischer rats. Pred was orally administered three times a week. In experiment 1, we compared the degree of bone loss induced by a 4 week treatment (30 or 100 mg/kg) and an 8 week treatment (3, 10, or 30 mg/kg) with pred by peripheral quantitative computed tomography (pQCT). At 4 weeks, total bone mineral density (BMD) was decreased only with the 100 mg/kg pred treatment. At 8 weeks, total BMD was significantly reduced at >10 mg/kg pred. In experiment 2, we investigated the effect of K(2) on bone loss induced by 3 and 30 mg/kg pred. K(2) (15 mg/kg) was given to rats as a dietary supplement for 8 weeks. Intestinal calcium transport (S/M) and total, trabecular, and cortical BMD at the metaphysis and diaphysis were measured, and histomorphometry was performed in diaphysial cross sections. Pred treatment decreased total and trabecular BMD in the proximal metaphysis. A decrease in cortical BMD in the diaphysis was observed in the pred 30 mg/kg group. Pred treatment also reduced mineralizing surface (MS/BS), mineral apposition rate (MAR), and bone formation rate (BFR/BS). The decrease in total and trabecular BMD in the proximal metaphysis, and in cortical BMD in the diaphysis, was inhibited by K(2) treatment. K(2) treatment also inhibited the decrease in MS/BS and BFR/BS induced by 30 mg/kg pred. These results suggest that K(2) prevents bone loss partly through the enhancement of bone formation.

Animals↗
PubMed1997

Tetracycline prevents cancellous bone loss and maintains near-normal rates of bone formation in streptozotocin diabetic rats.

The skeletal consequences of streptozotocin-induced (STZ) diabetes in the rat are characterized by decreased bone formation and, consequently, reductions in bone mass. Given the ability of tetracyclines to inhibit the breakdown of connective tissue collagen in experimental diabetes (and in other diseases), we examined the potential of this drug to prevent the osteopenia associated with STZ diabetes. To evaluate drug efficacy, the cortical and trabecular bone histomorphometry were analyzed and compared between vehicle-treated control and diabetic rats and control and diabetic rats treated orally with 20 mg/day of minocycline, a semisynthetic tetracycline. In addition, blood and urine glucose, body weight change, tibia lengths, cortical bone densities, and bone ash content were compared. At the end of the 26 day experimental period, diabetic (D) and minocycline-treated diabetic (MTD) rats were polyuric with reduced body weights and significantly elevated blood and urinary glucose levels (p < 0.01). Compared to control (C) and minocycline-treated control (MTC) animals, the periosteal and cancellous bone formation in the D rats had virtually ceased (p < 0.001), and the cancellous bone mass in the tibial metaphysis was reduced 47% (p < 0.01). In contrast, bone formation rates in the MTD animals were increased compared to the D rats (p < 0.001), while cancellous bone areas in the MTD animals were essentially equivalent to those observed in the C and MTC groups. Moreover, growth plate thickness, reduced 43% in the D rats, was preserved in the diabetic animals treated with minocycline. These results demonstrate that minocycline treatment of the streptozotocin diabetic rat maintains normal bone formation, normalizes growth plate thickness, and prevents cancellous bone loss.

Administration, Oral↗
PubMed1999

Stimulation of bone marrow cells and bone formation by nacre: in vivo and in vitro studies.

There is frequently a loss of vertebral bone due to disease or aging. Nacre (mother of pearl from the oyster Pinctada maxima) stimulates bone cell differentiation and bone formation in vitro and in vivo. Experimental bone defects were prepared in the vertebrae of sheep and used to test the suitability of nacre as an injectable osteogenic biomaterial for treating vertebral bone loss. Twenty-one cavities were prepared in the first four upper lumbar vertebrae of 11 sheep and filled with nacre powder. The lumbar vertebrae were removed after 1 to 12 weeks, embedded undecalcified in methacrylate, and processed for histological studies. The nacre slowly dissolved and the experimental cavities contained a large active cell population. By 12 weeks, the experimental cavity was occupied by newly matured bone trabeculae in contact with or adjacent to the dissolving nacre. The functional new bone trabeculae were covered with osteoid lined with osteoblasts, indicating continuing bone formation. The in vitro study on rat bone marrow explants cultured with a water-soluble extract of the nacre organic matrix also resulted in the stimulation of osteogenic bone marrow cells with enhanced alkaline phosphatase activity. Thus, both the in vivo and in vitro findings suggest that nacre contains one or more signal molecules capable of activating osteogenic bone marrow cells.

Alkaline Phosphatase↗
PubMed1999

Cortical tibial bone volume in two strains of mice: effects of sciatic neurectomy and genetic regulation of bone response to mechanical loading.

Although C3H/HeJ (C3H) and C57BL/6J (B6) mice are similar in body size (and adult weight), and have bones of similar external size, C3H mice have higher peak bone densities than B6 mice (e.g., 53% higher peak bone density in the femora). The current studies were intended to assess the role of mechanical loading/unloading as a possible determinant of the bone density difference between these inbred strains of mice and, specifically, to assess the effect of sciatic neurectomy on histomorphometric indices of bone formation and resorption in the tibiae of female C3H and B6 mice. Groups of 10 mice of each strain were subjected to left-side sciatic neurectomy (left hindlimb immobilization) or a sham procedure. The contralateral (right) legs of each mouse were used as controls. Four weeks of immobilization produced no systemic changes in bone formation indices in either strain of mice (i.e., no change in serum alkaline phosphatase or serum osteocalcin). However, histomorphometric assessments at the tibiofibular junction showed that 4 weeks of immobilization caused a time-dependent decrease in the length of the endosteal bone forming perimeter (e.g., 14% of control single-labeled, noneroded surface at 4 weeks, p < 0.005) with a concomitant increase in the length of the endosteal bone resorbing perimeter (i.e., 424% of control eroded surface at 4 weeks, p < 0.005), in the B6 mice. These effects were associated with an increase in medullary area (132% of control, p < 0.05) at this site, in the B6 mice. The pattern of response was different in the tibiae of the C3 mice-a much smaller decrease in bone forming perimeter (88% of control at 4 weeks, p < 0.05), with no associated increase in bone resorbing perimeter, and no change in medullary area. Similar effects were seen at a second cross-sectional sampling site, in the proximal tibia. Together, these findings indicate that B6 mice are more sensitive to endosteal bone loss from hindlimb immobilization than C3H mice.

Alkaline Phosphatase↗
PubMed2001

Molded bone augmentation by a combination of barrier membrane and recombinant human bone morphogenetic protein-2.

OBJECTIVES: To provide the histological background to a new method of local bone augmentation, we examined the events occurring beneath a barrier membrane applied with recombinant human bone morphogenetic protein-2 (rhBMP-2). MATERIALS AND METHODS: The effects on bone augmentation of rhBMP-2, applied with a membrane mold (BMP-Memb), over surgically-induced bone defects in rat calvaria were examined histologically, and the results compared with those from application of rhBMP-2 (BMP) alone, or of a molded membrane (Memb) alone. RESULTS: At postoperative week 2, the BMP group showed the most marked bone formation. However, the bone diminished in size by week 8. The Memb group showed slow but continuous bone formation by week 8. In the BMP-Memb group, bone filled the space in the mold at week 2, and this was maintained until week 8. Moreover, the soft tissue that had intervened between newly formed bone and the membrane in the Memb group was not evident in the BMP-Memb group, in which bone had formed directly on the membrane. CONCLUSIONS: The results suggest that the combination of rhBMP-2 and barrier membrane has advantages in producing and maintaining bone in the intended shape by inducing osteoblasts directly on the inner surface of the membrane.

Animals↗
PubMed1999

The relationship among circulating insulin-like growth factor components, biochemical markers of bone turnover and bone mineral density in postmenopausal women under the age of 60.

OBJECTIVES: The changes in circulating IGF components after the menopause and the potential role of new markers of bone turnover and circulating IGF components in predicting bone mass in postmenopausal women are still controversial and the relationship between these two systems has not been investigated. The aims of this study were to investigate the changes in circulating IGF components after the menopause, to evaluate whether new markers of bone turnover and circulating IGF components reflect bone mass in postmenopausal women under the age of 60 and to study the relationship between these two systems. DESIGN, PATIENTS AND MEASUREMENTS: Serum IGF-I, IGF-II, IGFBP-1, IGFBP-2, IGFBP-3, osteocalcin (OST), bone specific alkaline phosphatase (BAP), urinary deoxypyridinoline (DPYD) and N-telopeptide of type I collagen (NTX) were measured in 31 premenopausal women aged 31-43 and 65 postmenopausal women aged 47-60: this latter group comprised 30 normal healthy women and 35 osteoporotic women. RESULTS: Compared with premenopausal women or normal postmenopausal women, serum IGF-1 and IGFBP-3 levels were significantly lower in osteoporotic postmenopausal women while no significant differences in serum levels of IGF-II, IGFBP-1 and IGFBP-2 were observed. The correlations between bone turnover markers and circulating IGF components (except between serum BAP and IGF-II), and between bone turnover markers and bone mineral density (BMD) in postmenopausal women were not significant. However, serum IGF-I and IGFBP-3 correlated positively with BMD of the lumbar spine and/or Ward's triangle even if age, BMI and menopause duration were taken into account in a multiple regression analysis model. CONCLUSIONS: Circulating IGF-I and IGFBP-3 may be involved in the mechanism of bone loss in postmenopausal women under the age of 60. They may also provide indirect information on the current bone microenvironment different from that provided by new markers of bone turnover.

Adult↗