Bone histomorphometry in transiliac biopsies from 48 normal, healthy men.

Investigators and clinicians use bone histomorphometry data from iliac bone biopsies to study bone abnormalities in diseased patients, and to understand the safety and effectiveness of pharmaceutical interventions. This requires access to a high quality normal data-set to be used for comparisons, a resource that has not been adequate to date. The objective of this work is to present static and dynamic bone histomorphometry data from transilial bone biopsies performed on 48 healthy males, evenly distributed between ages 45 and 75. In addition, we compared these results with results from our earlier study in normal postmenopausal women (Recker et al., 1988 [1]). The data include bone density and anthropometric measurements, micro-CT, and a collection of serum biochemical measurements. We found that several of the histomorphometry variables were correlated with serum measurements, i.e. serum testosterone and sex hormone-binding globulin (SHBG). Micro-CT variables were correlated with the static histomorphometry variables, and were very similar. Age-related changes were observed for both histomorphometry and Micro-CT, but were surprisingly small in most cases. Comparisons with our previously reported histomorphometry data from normal women were surprisingly similar, but there was a significant age by gender interaction in the wall thickness (W.Th) measurements, i.e. there was a small increase in this variable with age in men, and a significant decline with age in women. The population selected for this study, and the prior study in normal women, were carefully chosen so as to rule out the presence of clinical, life-style or other confounding factors. While the cohort chosen herein was a convenience sample, and not a population-based sample, we believe it can be used as a reference standard with proper precautions in its interpretation and in its comparisons with diseased populations.

Case report: Electron microscopic evaluation of bone from a patient treated with cinacalcet hydrochloride, maxacalcitol, and alfacalcidol for hyperparathyroid bone disease with secondary hyperparathyroidism.

Evaluation of bone is of great importance in chronic kidney disease patients, as these patients are at an increased risk for fractures. We treated a hemodialysis patient suffering from hyperparathyroid bone disease with cinacalcet hydrochloride and concurrent administration of maxacalcitol and alfacalcidol for a year. Hyperparathyroid bone disease is characterized by cortical thinning, increased cortical porosity, reduced trabecular bone volume, and increased hypomineralized matrix volume, and there is little information to date about the effects of treatment with cinacalcet hydrochloride on the bone fragility in patients with hyperparathyroid bone disease. In the present study, histological and backscattered electron microscopic evaluation of this combination treatment revealed an excellent improvement of both bone volume and bone morphology. This treatment improved cortical thinning, cortical porosity, and trabecular thinning. Furthermore, the treatment also reduced hypomineralized matrix volume, indicative of improved mineralization by osteocytes. We speculate that the intermittent maxacalcitol administration may have effectively stimulated the vitamin D receptors expressed on osteocytes and osteoblasts, resulting in increased mineralization. Our approach for evaluating the bone in patients with chronic kidney disease by backscattered electron microscopy is novel.

Bone matrix mineralization is preserved during early perimenopausal stage in healthy women: a paired biopsy study.

UNLABELLED: Bone matrix mineralization based on quantitative backscatter electron imaging remained unchanged during the first year of menopause in paired transiliac biopsy samples from healthy women. This suggests that the reported early perimenopausal reductions in bone mineral density are caused by factors other than decreases in the degree of mineralization. INTRODUCTION: It is unknown whether perimenopausal loss of bone mass is associated with a drop in bone matrix mineralization. METHODS: For this purpose, we measured the bone mineralization density distribution (BMDD) by quantitative backscatter electron imaging (qBEI) in n = 17 paired transiliac bone biopsy samples at premenopausal baseline and 12 months after last menses (obtained at average ages of 49 ± 2 and 55 ± 2 years, respectively) in healthy women. For interpretation of BMDD outcomes, previously measured bone mineral density (BMD) and biochemical and histomorphometric markers of bone turnover were revisited for the present biopsy cohort. RESULTS: Menopause significantly decreased BMD at the lumbar spine (-4.5 %) and femoral neck (-3.8 %), increased the fasting urinary hydroxyproline/creatinine ratio (+60 %, all p < 0.01) and histomorphometric bone formation rate (+25 %, p < 0.05), but affected neither cancellous nor cortical BMDD variables (paired comparison p > 0.05). Mean calcium concentrations of cancellous (Cn.CaMean) and cortical bone (Ct.CaMean) were within normal range (p > 0.05 compared to established reference data). Ct.CaMean was significantly correlated with Cn.CaMean before (R = 0.81, p < 0.001) and after menopause (R = 0.80, p < 0.001) and to cortical porosity of mineralized tissue (Ct.Po.) after menopause (R = -0.57, p = 0.02). CONCLUSIONS: Surprisingly, the BMDD was found not affected by the changes in bone turnover rates in this cohort. This suggests that the substantial increase in bone formation rates took place shortly before the second biopsy, and the bone mineralization changes lag behind. We conclude that during the first year after the last menses, the degree of bone matrix mineralization is preserved and does not contribute to the observed reductions in BMD.

Bone impairment in oxalosis: An ultrastructural bone analysis.

Deposition of calcium oxalate crystals in the kidney and bone is a hallmark of systemic oxalosis. Since the bone compartment can store massive amounts of oxalate, patients present with recurrent low-trauma fractures, bone deformations, severe bone pains and specific oxalate osteopathy on plain X-ray. Bone biopsy from the iliac crest displays specific features such as oxalate crystals surrounded by a granulomatous reaction due to an invasion of bone surface by macrophages. We present data obtained in 10 samples from 8 patients with oxalosis (16-68 years) who underwent iliac crest bone biopsy and bone quality analysis using modern methods (microradiography, microindentation, Fourier Transform InfraRed Microspectroscopy, transmission electron microscopy) in addition to histomorphometry. Disseminated calcium oxalate deposits (whewellite) were found in the bone marrow space (with a granulomatous reaction) but not in the bone matrix. Calcium oxalate deposits were totally surrounded by macrophages and multinucleated giant cells, and a phagocytosis activity was sometimes observed. Very few calcium oxalate crystals were directly in close contact with the mineral substance of the bone. Bone mineralization was not modified by the presence of calcium oxalate even in close vicinity. Bone quality analysis also revealed a harder bone than normal, perhaps in relationship with decreased carbonate content in the mineral. This increase in bone hardness could explain a more "brittle" bone. In patients with oxalosis, the formation and growth of calcium oxalate crystals in the bone appeared independent of apatite. The mechanisms leading to nucleation and growth of oxalate deposits are still unclear and deserve further studies.

Multipotential stromal cell abundance in cellular bone allograft: comparison with fresh age-matched iliac crest bone and bone marrow aspirate.

AIM: To enumerate and characterize multipotential stromal cells (MSCs) in a cellular bone allograft and compare with fresh age-matched iliac crest bone and bone marrow (BM) aspirate. MATERIALS & METHODS: MSC characterization used functional assays, confocal/scanning electron microscopy and whole-genome microarrays. Resident MSCs were enumerated by flow cytometry following enzymatic extraction. RESULTS: Allograft material contained live osteocytes and proliferative bone-lining cells defined as MSCs by phenotypic and functional capacities. Without cultivation/expansion, the allograft displayed an 'osteoinductive' molecular signature and the presence of CD45(-)CD271(+)CD73(+)CD90(+)CD105(+) MSCs; with a purity over 100-fold that of iliac crest bone. In comparison with BM, MSC numbers enzymatically released from 1 g of cellular allograft were equivalent to approximately 45 ml of BM aspirate. CONCLUSION: Cellular allograft bone represents a unique nonimmune material rich in MSCs and osteocytes. This osteoinductive graft represents an attractive alternative to autograft bone or composite/synthetic grafts in orthopedics and broader regenerative medicine settings.

Early effects of zoledronic acid and teriparatide on bone microarchitecture, remodeling and collagen crosslinks: comparison between iliac crest and lumbar vertebra in ewes.

Iliac crest bone biopsies are used to assess the mechanism of action of drug treatments, yet there are little data comparing this site to sites prone to fracture. The purpose of this study was to compare the delay and the amplitude of responses to treatment in two different bone sites. The short-term effects of zoledronic acid and teriparatide on microarchitecture, collagen crosslinks and bone remodeling were evaluated in iliac crest and lumbar vertebrae. Aged ewes (n=8/gr) received either vehicle (CTRL) or a single injection of zoledronic acid (ZOL, 10mg) or daily injections of teriparatide (TPTD, 20 µg/d) for 3 months. Blood samples were collected monthly for assessing bone turnover markers. At the end of the study, a transiliac bone biopsy (IC) and L1 lumbar vertebrae (LV1) were collected to assess bone microarchitecture; pyridinoline (PYD), deoxypyridinoline (DPD), pentosidine (PEN) content, static and dynamic parameters of bone remodeling. In CTRL, Tb-BV/TV was significantly higher in LV1 than IC (p<0.0001). This was associated with a trend of higher Tb.N, Tb.Th, DA, an inferior Conn.D and a lower bone turnover as shown by the decreases of osteoid parameters, MS/BS, Ac.f in LV1 when compared to IC. In addition, the ratio PYD/DPD was 4 times higher in LV1 than IC. After 3 months, significant decreases of sALP (p<0.001) and sCTX (p<0.001) were observed in the ZOL-group whereas in TPTD-group, after transient increases, they returned to baseline values. When compared to their respective CTRL, ZOL induced significant increases in Tb.BV/TV, Conn.D, Tb.N and Tb.Sp, in IC but not in LV1. Regardless of the site, ZOL markedly depressed the bone turnover: The static parameters of bone formation significantly decreased and the diminution of MS/BS, BFR/BS and Ac.f varied from -94 to -98% vs CTRL (p<0.01 to 0.001). It was associated with a diminution of the DPD content and the PYD/DPD ratio mainly in IC cortices. In contrast, after 3 months, TPTD did not modify the 3D structure and microarchitecture in IC and LV1, except a trend of higher Conn.D in IC, compared to IC-CTRL. TPTD treatment induced a significant increase in cortical porosity in LV1 (p<0.05) when compared to LV1-CTRL. Static parameters of bone formation and resorption were augmented in both sites, significantly only in LV1 (p<0.05) with a trend of increases in MS/BS and BFR/BS, compared to LV1-CTRL. In conclusion, in adult ewes, the bone mass, microarchitecture, remodeling and collagen crosslink content differ according to the bone site (iliac crest and vertebra). Furthermore, after 3 months, the responses to ZOL and TPTD were of different magnitude and delay between the two bone sites. The distinction of bone sites to study the early effects of anti-osteoporotic therapies appears meaningful in order to approach their site-specific anti-fracture efficacy.

Trabecular bone histomorphometry in humans with Type 1 Diabetes Mellitus.

Patients with Type 1 Diabetes Mellitus (DM) have markedly increased risk of fracture, but little is known about abnormalities in bone microarchitecture or remodeling properties that might give insight into the pathogenesis of skeletal fragility in these patients. We report here a case-control study comparing bone histomorphometric and micro-CT results from iliac biopsies in 18 otherwise healthy subjects with Type 1 Diabetes Mellitus with those from healthy age- and sex-matched non-diabetic control subjects. Five of the diabetics had histories of low-trauma fracture. Transilial bone biopsies were obtained after tetracycline labeling. The biopsy specimens were fixed, embedded, and scanned using a desktop µCT at 16 µm resolution. They were then sectioned and quantitative histomorphometry was performed as previously described by Recker et al. [1]. Two sections, >250 µm apart, were read from the central part of each biopsy. Overall there were no significant differences between diabetics and controls in histomorphometric or micro-CT measurements. However, fracturing diabetics had structural and dynamic trends different from nonfracturing diabetics by both methods of analysis. In conclusion, Type 1 Diabetes Mellitus does not result in abnormalities in bone histomorphometric or micro-CT variables in the absence of manifest complications from the diabetes. However, diabetics suffering fractures may have defects in their skeletal microarchitecture that may underlie the presence of excess skeletal fragility.

Comparison of quantitative cancellous bone connectivity analyses at two- and three-dimensional levels in dialysis patients.

Assessment of cancellous bone connectivity has the potential to aid in predicting fracture risk. Today, cancellous bone connectivity is generally assessed using bone sections obtained from biopsy. However, how reliably such two-dimensional (2-D) analyses visualize the 3-D properties has not been evaluated. Biopsied iliac bone samples were obtained from 47 chronic hemodialysis patients. Bone samples were observed using a microfocus X-ray computed tomography (microCT) system en bloc, and the cancellous bone microstructure was quantitatively assessed at both the 2- and 3-D levels. Cancellous bone microarchitecture was successfully reconstructed from the data obtained by the microCT system. Most of the results from node-strut analysis (NSA) revealed no statistically significant correlations between the 2- and 3-D analyses, with the exception that the number of nodes (N.Nd/TV) showed a mild but significant correlation. In contrast, the marrow space star volumes (V*m) of the 2- and 3-D analyses were highly correlated. NSA parameters including N.Nd/TV showed significant correlations with V*m at the 3-D level. In conclusion, V*m values were similar in the 2- and 3-D analyses, while most of the 2-D NSA parameters did not reflect the 3-D ones. Since V*m and most of the NSA parameters were correlated in the 3-D analyses, 2-D NSA would seem to have serious limitations for the assessment of cancellous bone microstructural properties. Further studies will thus be needed to establish appropriate methods for assessing cancellous bone connectivity in clinical practice.

A histological and ultrastructural study of the iliac crest apophysis in Legg-Calve-Perthes disease.

BACKGROUND: Legg-Calve-Perthes disease (LCPD) is a common hip disorder in children characterized by avascular necrosis of the proximal capital femoral epiphysis. The underlying etiology of the vascular disturbance is still unknown, but it is suggested that LCPD may be a part of a generalized constitutional disorder associated with growth disturbance of bone and cartilage tissue. In this study, the biopsy specimens of the iliac crest apophysis from LCPD patients were examined histologically and ultrastructurally to determine preexisting generalized abnormalities of endochondral ossification. METHODS: Iliac crest apophysis cartilage was taken during Salter innominate osteotomy from 11 children (8 boys and 3 girls) with LCPD at an average age of 7.8 years. As controls, the samples were also obtained from 10 children (2 boys and 8 girls) at an average age of 6.3 years undergoing Salter osteotomy due to residual acetabular dysplasia after reduction of developmental dysplasia of the hip. Each iliac crest apophysis specimen was examined histologically (Toluidine blue staining and Sudan III staining) and ultrastructurally. RESULTS: Although there were no obvious differences in Toluidine blue-stained sections of the iliac crest cartilage between LCPD and control patients, the Sudan III-positive chondrocytes in the resting cartilage were more prominent in the LCPD specimens than in the control specimens. These sudanophilic granules were confirmed to be lipid droplets by electron microscopic examinations. Ultrastructural examinations of the resting chondrocytes from 3 LCPD patients demonstrated numerous cytoplasmic inclusion bodies with electron dense materials, which were similar to those seen in some of the mucopolysaccharidoses. CONCLUSIONS: Increased lipid droplets and numerous cytoplasmic inclusions filled with fibrillar materials were suggestive of the initial metabolic changes of the chondrocytes, which may have a pivotal role in degenerating matrix and lead to vulnerability of the cartilage tissue. Our results indicated that generalized insufficiency in growth cartilage metabolism may be related to the onset of the disease in some LCPD patients.

Side-to-side and within-side variability of 3D bone microarchitecture by conventional micro-computed tomography of paired iliac crest biopsies.

Bone microarchitecture in osteoporosis can be characterized by examining iliac bone biopsies and treatment effects assessed by comparing a baseline biopsy from one side to a posttreatment biopsy from the other side, a method that assumes limited side-to-side variability. New techniques based on micro-computed tomography (microCT) provide information on the three-dimensional (3D) microarchitecture of bone. We used microCT to measure side-to-side and within-side variability of 3D microarchitectural parameters of trabecular and cortical bone in paired iliac-crest biopsies, one from each side. A Bordier needle trephine was used to collect biopsies from 30 postmenopausal female cadavers (mean age, 73.7+/-10.7 years; range, 55-96 years). Biopsies were chemically defatted then imaged using a desktop microCT scanner (voxel size, 10.77 microm). Parameters measured in trabecular bone consisted of bone volume/tissue volume (BV/TV, %), direct trabecular thickness and trabecular spacing (Tb.Th and Tb.Sp, microm) using the sphere method, bone surface/bone volume (BS/BV, mm(-1)), trabecular number (Tb.N, mm(-1)), structure model index (SMI), trabecular pattern factor (Tb.Pf), and degree of anisotropy (DA). In cortical bone, we measured cortical thickness (Cort.Th), porosity (Cort.Porosity), and pore diameter (Po.Dm). For trabecular bone parameters, reproducibility as assessed from two microCT acquisitions ranged from 4.1% to 6.9%. To assess side-to-side variability, we matched the volumes of interest selected in the right and left iliac crests. The mean difference in absolute individual percent variation (mAbsDelta(ind)) between the two sides ranged from 10.8% to 14.8% for all trabecular parameters except Tb.Pf (74%) and SMI (84%). In cortical bone, mAbsDelta(ind) were 11.6% for Po.Dm, 15.1% for Cort.Porosity, and 27.6% for Cort.Th. To assess within-side variability, we divided the trabecular iliac crest volume into three equal parts, one adjacent to each cortex and one in the middle. Values of mAbsDelta(ind) versus the middle part were ranging from 7.6% for Tb.Sp to 26.2% for BV/TV. Thus, within-side variability was similar in magnitude to side-to-side variability. The considerable differences in robustness across trabecular parameters indicate a need for selecting the most stable parameters, most notably for longitudinal studies of small numbers of patients. Acquisition by microCT and image analysis must comply with stringent quality criteria, especially the distance from the cortices must be standardized.

Increased bone resorption with decreased activity and increased recruitment of osteoblasts in osteogenesis imperfecta type I.

An iliac bone biopsy from an adult male, 58 years of age, with osteogenesis imperfecta type I was studied by bone histomorphometry after double-fluorescence labeling with tetracycline. Low bone mineral density (BMD) of the radius, measured by dual-energy X-ray absorptiometry (DXA) was associated with high levels of urinary deoxypyridinoline and serum bone-specific alkaline phosphatase and osteocalcin. At the tissue level, low cancellous bone volume (BV/TV) was associated with increased eroded surface (ES/BS) and a relatively increased osteoclast number (N.Oc/BS). Osteoid thickness (O.Th) was also decreased as a result of decreased bone matrix synthesis, in terms of decreased osteoblastic activity. However, osteoid surface (OS/BS) and osteoblast surface (ObS/BS), in terms of the number of osteoblasts, were increased. We conclude that the patient showed cancellous osteopenia, which was likely due to increased bone resorption with decreased activity and increased recruitment of osteoblasts.

Trabecular architecture in women and men of similar bone mass with and without vertebral fracture: I. Two-dimensional histology.

While osteoporosis is characterized by a low bone mass there is a well-recognized overlap in bone mineral density (BMD) measurements between groups of subjects with and without vertebral fracture. To investigate whether differences in trabecular architecture may contribute to the presence or absence of fractures independent of the bone mass, fracture and nonfracture groups matched for age, gender, and BMD were assembled. Transiliac biopsies and corresponding lumbar spine BMD measurements from 31 women and 16 men with vertebral fracture were compared with those from 22 women and 11 men without fracture. Lumbar BMD (L1-4) was measured using a Hologic 2000 densitometer. The lumbar BMD was similar in women with and without fracture (0.63 g/cm(3) +/- 0.10 SD and 0.71 g/cm(3) +/- 0.17 SD, n.s.) and in men with and without fracture (0.72 g/cm(3) +/- 0.12 SD and 0.76 g/cm(3) +/- 0.17 SD, n.s.). Undecalcified iliac crest biopsy sections, 8 microm thick, were analyzed for remodeling variables and trabecular architecture using OsteoMeasure and TAS image analysis systems. No significant difference was found in either gender between fracture and nonfracture groups in percent bone volume (mean 10% in all groups), or in the wide range of remodeling and architectural variables measured, including the trabecular width, number, and separation, mean trabecular plate density and fractal dimension, as well as several indirect indices of connectivity including the node:terminus ratio, marrow star volume, and trabecular pattern factor. On the basis of this evidence it was concluded that there is no difference in the trabecular architecture between patients with crush fracture and controls when account is taken of bone mass. This suggests that microanatomical disruption is a predictable intrinsic feature of bone loss. However, there remains the possibility that the two-dimensional character of the structural deterioration measured indirectly is not sufficiently sensitive for the complex cancellous system. This is considered further in part II.

Trabecular architecture in women and men of similar bone mass with and without vertebral fracture: II. Three-dimensional histology.

We recently developed a simple and inexpensive method that complements established bone histomorphometry procedures by enabling the two-dimensional imaging of cancellous bone to be viewed within its three-dimensional context with the marrow tissue in place and without detriment to the material for other histological purposes. The method, based on the preparation and superficial staining of slices 300 microm thick, enables "real" (i.e., unstained) trabecular termini to be separated from "artifactual" (i.e., stained) termini, providing a direct measure of cancellous connectivity in osteopenic bone. The technique was applied to osteopenic age-matched, white, postmenopausal women (31 with and 22 without vertebral compression fractures) with a similar bone status, as measured at the spine by absorptiometry and at the iliac crest by histology (see part I of this study). Despite the similarity in the mass of trabecular bone at either site, the results showed a significant difference (p < 0. 05) in the number of "real" trabecular termini between the groups, such that the fracture group had almost four times as many termini (mean +/- SE: 1.98 +/- 0.51/30 mm(2)) at the iliac crest as the nonfracture group (mean +/- SE: 0.53 +/- 0.31/30 mm(2)). Previous histomorphometry of the same material failed to detect a structural distinction between the two groups using established variables. It was concluded that a mass-independent trabecular discontinuity contributes to skeletal failure and that determination of the number of "real" disconnections (i.e., unstained termini) by the direct method proposed may provide a more sensitive discriminant of fracture than the present indirect procedures. A group of fracture and nonfracture men (see part I) suggested a similar distinction (fracture: 0.69 +/- 0.30/30 mm(2); nonfracture: 0.18 +/- 0.18/30 mm(2)), although the difference was not significant.

The ovariectomised sheep as a model for testing biomaterials and prosthetic devices in osteopenic bone: a preliminary study on iliac crest biopsies.

A histomorphometric and ultrastructural evaluation on sheep iliac bone was performed. Six sheep were ovariectomised (OVX Group) and 6 were left intact (Sham-aged, Control Group). An iliac crest biopsy was performed randomly in 6 animals at the beginning of the study, then, in all the animals, after 12 and 24 months. A significant decrease in trabecular bone volume, trabecular thickness (p<0.0005) and cell volume (p<0.005) was observed in OVX animals. A modest decrease in trabecular number and osteoid thickness together with an increase in trabecular separation were observed in OVX animals at 12 and 24 months. The osteoid volume showed a significant difference (p<0.05) between the groups. In OVX animals, at 12 months, Scanning Electron Microscopy revealed an enlargement of the trabecular space and a progressive replacement of bone matrix with adipose tissue. These signs were accentuated at 24 months. In conclusion, OVX sheep showed a loss of trabecular bone starting at 12 months after ovariectomy. The developed osteopenic state may be considered as a useful tool when doing research on biomaterial osteointegration.

Enhanced neutrophilic granulopoiesis in rheumatoid arthritis. Involvement of neutrophils in disease progression.

OBJECTIVE: To investigate enhanced granulopoiesis in bone marrow of patients with rheumatoid arthritis (RA), and the role of neutrophils in RA pathogenesis. METHODS: Aspirated bone marrow cells and peripheral blood leukocytes from patients with RA and non-RA patient controls were analyzed morphologically and by 2 color flow cytometry. Thirteen iliac bones (8 RA, 5 non-RA) were examined by light and transmission electron microscope (TEM). RESULTS: The percentage of CD15+CD16- cells (immature neutrophils) in RA bone marrow (64.3+/-13.4%, mean +/- SD) increased significantly compared to that of non-RA controls (43.2+/-14.3%), whereas the fraction of CD15+CD]6+ cells (mature neutrophils)was greatly decreased (RA 21.8+/-10.1%; non-RA 38.1+/-8.9%). The absolute number of CD15+CD16- cells also increased markedly in RA bone marrow. The ratio of immature cells to the total granulocytes (% CD15+CD16- to % CD15+) correlated with the Lansbury Index score (R = 0.76, p<0.0001). TEM observations revealed that abundant immature neutrophils adhered closely to the trabeculae of the iliac bone. Margins of trabeculae were mostly irregular, especially in severe RA, and collagenous fibers frequently disappeared in those trabeculae with ragged margins. CONCLUSION: In RA bone marrow, immature neutrophils (CD15+CD16-) were markedly increased in number; by contrast, no changes were found for mature cells. Augmented production of immature neutrophils (at the promyelocyte-to-myelocyte stage) might lead to the destruction of collagenous fibers in RA bone trabeculae, as revealed by TEM. Generalized bone destruction in RA might, at least in part, be caused by enhanced production of immature neutrophils.

Primary angioleiomyoma of the iliac bone: clinical pathological study of one case with flow cytometric DNA content and S-phase fraction analysis.

We report on a primary angioleiomyoma of the right iliac bone in a 28-year-old woman. To our knowledge this is the 16th reported case of a primary leiomyoma of bone, the 9th reported primary osseous angioleiomyoma and the first description of a primary angioleiomyoma located in the iliac bone. The problems of differentiating primary leiomyoma of bone from primary or metastatic leiomyosarcoma of bone are stressed. A literature review of primary leiomyomas of bone is presented.

Bone turnover associated with antler growth in red deer (Cervus elaphus).

Although it is known that skeletal bone depletion occurs during antler growth in deer, it is not clear whether repletion of the skeleton takes place before or after completion of antler development. This study attempted to correlate repeated scanning electron microscopic measures of ilium and rib bone porosity from six approximately 2-monthly biopsy samples (using back-scattered imaging) and biochemical markers of bone turnover (serum hydroxyproline and osteocalcin concentrations) taken for 11 months with antler growth in six red deer stags. No changes were detected in ilium samples but changes in porosity of rib bones and an elevation of the biochemical markers indicated that skeletal depletion occurred during the antler growth period. However, the decrease in rib bone porosity and decline in markers of bone turnover took place before completion of antler growth, indicating that a considerable amount of skeletal repletion could have occurred whilst antlers were also undergoing bone accretion. This latter finding extends the current view of antler growth being accompanied by a form of reversible osteoporosis in the skeleton by showing that there is a period when the antlers and skeleton are both undergoing net bone formation.

The mineralization density of iliac crest bone from children with osteogenesis imperfecta.

We studied iliac crest biopsy cores taken from young individuals with osteogenesis imperfecta of several types, and from age-matched normals; the same samples had been used in prior studies using conventional light microscopic histomorphometric procedures. The PMMA blocks were micro-milled to a fine finish, carbon coated, and imaged using backscattered electrons (BSE) in an automated digital scanning electron microscope (SEM). For comparison of BSE signal levels between samples, microscope operation parameters were standardized by reference to halogenated dimethacrylate standards, and recording data from stereological arrays of 512*512 nonoverlapping pixels at 3.5 micrometer separation. All OI types showed higher average mineralization densities than age- and site-matched normals. This is interpreted as the result of the failure in matrix assembly, such that it has a higher water volume fraction available for mineral deposition. Added to the net deficit in bone quantity, the predicted higher stiffness of the more mineralized bone will account for much of the observed 'brittleness' that characterizes this class of genetic disease. The mean mineralization density, which was higher in types III, IV, and V than in type I, appears to be correlated with disease severity.

Ultrastructural findings of bone marrow in a case with malignant osteopetrosis following successful allogeneic bone marrow transplantation.

A nine-month-old female patient suffering from malignant osteopetrosis was evaluated by light and transmission electron microscopic study before and following allogeneic bone marrow transplantation (BMT). Bone marrow specimens were obtained from iliac crest biopsies. Before BMT, the bone marrow had an irregular appearance and was filled with bridging bony trabeculae devoid of cells. Following BMT, the marrow had an almost normal appearance with no myelofibrosis and a relatively regular distribution of hematopoletic cells. The osteocytes were visible in their lacunae in the bone matrix. Presence of bone resorbing and bone forming cell together demonstrated that the bone was beginning to gain its normal dynamic structure. These findings were in accordance with the clinical, laboratory and radiological data which showed the beneficial effect of the therapy.

Validation of quantitative backscattered electron imaging for the measurement of mineral density distribution in human bone biopsies.

The measurement of bone mineral density (BMD) using X-rays is usually employed to monitor the mineral content in a given portion of bone. However, this method cannot differentiate between changes in bone volume or in degree of mineralization of the bone matrix. In contrast to BMD, bone mineral density distribution (BMDD), as measured on bone sections by quantitative backscattered electron imaging (qBEI), is able to distinguish differences in the degree of mineralization. For routine clinical research, we have validated the method of calibration and standardization of the backscattered electron (BE) signal. Carbon and aluminum were used as reference materials for BE gray levels and osteoid and apatite for calcium concentration. Experiments were performed to get knowledge about precision (intraassay variance-instrumental stability and interassay variance-reproducibility) and accuracy (standardization) of this method as well as the biological variance (intraindividual and interindividual) in human bone. On transiliac biopsies or necropsies from 20 individuals having had accidental death (13 females, 7 males, age 30-85 years) BMDD measurements were conducted. The patients' medical history as well as the histomorphology of these bones showed no evidence of metabolic bone disease. For instance, the standard deviations of the weighted mean calcium concentrations were <0.3%, <0.4%, <0.9%, and <2.6% of the mean for the intraassay, interassay, intraindividual, and interindividual variations, respectively. In addition, a mean BMDD histogram for transiliac bone specimens was calculated from the 20 aforementioned individuals. The method used allows detection of the degree of mineralization independently from the actual bone volume, a result that seems to be of special interest in the assessment of the effect of treatments for osteoporosis. The power of this technique is demonstrated by using bone from a patient with a metabolic bone disease. In this case of osteomalacia due to celiac disease, the mean calcium concentration in the bone matrix was reduced by 19.3% as compared with normal.