bluuebunny/crossref_metadata_2025_split huggingface dataset:
Osteocytic Expression of Constitutive NO Synthase Isoforms in the Femoral Neck Cortex: A Case-Control Study of Intracapsular Hip Fracture
Authors: Caballero-Alías Ana Maria , Loveridge Nigel , Pitsillides Andrew , Parker Martyn , Kaptoge Stephen , Lyon Alan , Reeve Jonathan 
Published: April 2006

Abstract
NO is an osteocytic signaling molecule that can inhibit osteoclasts. The NO synthases eNOS and nNOS were expressed by &gt;50% of osteonal osteocytes in controls. Hip fracture cases showed +NOS osteocytes only in deep osteonal bone, and 25–35% reduced expression overall. These data are consistent with increased osteonal vulnerability to deep osteoclastic attack.
Introduction: Osteocytes may regulate the response to mechanical stimuli in bone through the production of local signaling molecules such as NO derived from the NO synthase eNOS. Because NO is inhibitory to osteoclastic resorption, it has been suggested that osteocytes expressing eNOS act as sentinels, confining resorption within single osteons. Recently, nNOS has been shown to be present in osteocytes of adult human bone.
Materials and Methods: Cross-sections of the femoral neck (eight female cases of intracapsular hip fracture and seven postmortem controls; age, 68–91 years) were analyzed by immunohistochemistry. The percentages of osteocytes expressing each of these two isoforms were calculated, and their distances to the nearest canal surface were measured.
Results: The percentage of +nNOS osteocytes was lower in the fracture cases than in the controls (cases: 43.12 ± 1.49, controls: 56.68 ± 1.45; p &lt; 0.0001). Compared with nNOS, eNOS expression was further reduced (p = 0.009) in the cases but was not different in the controls (cases: 36.41 ± 1.53, controls: 56.47 ± 2.41; p &lt; 0.0001). The minimum distance of +eNOS or +nNOS osteocytes to a canal surface was higher in the cases compared with controls (eNOS: controls; 44.4 ± 2.2 μm, cases: 61.7 ± 2.0 μm; p &lt; 0.0001; nNOS: controls: 52.4 ± 1.7 μm, cases: 60.2 ± 2.1 μm; p = 0.0039). +eNOS osteocytes were closer to the canal surfaces than +nNOS osteocytes in the controls by 8.00 ± 4.0 μm (p = 0.0012).
Conclusion: The proportions of osteocytes expressing nNOS and eNOS were both reduced in the fracture cases, suggesting that the capacity to generate NO might be reduced. Furthermore, the reduction in NOS expression occurs in those osteocytes closest to the canal surface, suggesting that the ability of NO to minimize resorption depth might be impaired. Further studies are needed on the regulation of the expression and activity of these distinct NOS isoforms.
Bone Markers, Calcium Metabolism, and Calcium Kinetics During Extended-Duration Space Flight on the Mir Space Station
Authors: Smith Scott M , Wastney Meryl E , O'Brien Kimberly O , Morukov Boris V , Larina Irina M , Abrams Steven A , Davis-Street Janis E , Oganov Victor , Shackelford Linda C 
Published: April 2006

Abstract
Bone loss is a current limitation for long-term space exploration. Bone markers, calcitropic hormones, and calcium kinetics of crew members on space missions of 4–6 months were evaluated. Spaceflight-induced bone loss was associated with increased bone resorption and decreased calcium absorption.
Introduction: Bone loss is a significant concern for the health of astronauts on long-duration missions. Defining the time course and mechanism of these changes will aid in developing means to counteract these losses during space flight and will have relevance for other clinical situations that impair weight-bearing activity.
Materials and Methods: We report here results from two studies conducted during the Shuttle-Mir Science Program. Study 1 was an evaluation of bone and calcium biochemical markers of 13 subjects before and after long-duration (4–6 months) space missions. In study 2, stable calcium isotopes were used to evaluate calcium metabolism in six subjects before, during, and after flight. Relationships between measures of bone turnover, biochemical markers, and calcium kinetics were examined.
Results: Pre- and postflight study results confirmed that, after landing, bone resorption was increased, as indicated by increases in urinary calcium (p &lt; 0.05) and collagen cross-links (N-telopeptide, pyridinoline, and deoxypyridinoline were all increased &gt;55% above preflight levels, p &lt; 0.001). Parathyroid hormone and vitamin D metabolites were unchanged at landing. Biochemical markers of bone formation were unchanged at landing, but 2–3 weeks later, both bone-specific alkaline phosphatase and osteocalcin were significantly (p &lt; 0.01) increased above preflight levels. In studies conducted during flight, bone resorption markers were also significantly higher than before flight. The calcium kinetic data also validated that bone resorption was increased during flight compared with preflight values (668 ± 130 versus 427 ± 153 mg/day; p &lt; 0.001) and clearly documented that true intestinal calcium absorption was significantly lower during flight compared with preflight values (233 ± 87 versus 460 ± 47 mg/day; p &lt; 0.01). Weightlessness had a detrimental effect on the balance in bone turnover such that the daily difference in calcium retention during flight compared with preflight values approached 300 mg/day (−234 ± 102 versus 63 ± 75 mg/day; p &lt; 0.01).
Conclusions: These bone marker and calcium kinetic studies indicated that the bone loss that occurs during space flight is a consequence of increased bone resorption and decreased intestinal calcium absorption.
Ubiquitin-Associated Domain Mutations of SQSTM1 in Paget's Disease of Bone: Evidence for a Founder Effect in Patients of British Descent
Authors: Lucas Gavin JA , Hocking Lynne J , Daroszewska Anna , Cundy Tim , Nicholson Geoff C , Walsh John P , Fraser William D , Meier Christian , Hooper Michael J , Ralston Stuart H 
Published: April 2006

Abstract
Mutations in the UBA domain of SQSTM1 are a common cause of Paget's disease of bone. Here we show that the most common disease-causing mutation (P392L) is carried on a shared haplotype, consistent with a founder effect and a common ancestral origin.
Introduction: Paget's disease of bone (PDB) is a common condition with a strong genetic component. Mutations affecting the ubiquitin-associated (UBA) domain of sequestosome 1 (SQSTM1) have recently been shown to be an important cause of PDB. The most common mutation results in a proline to leucine amino acid change at codon 392 (P392L), and evidence has been presented to suggest that there may be a recurrent mutation rather than a founder mutation on an ancestral chromosome. Because marked geographical differences exist in the prevalence of PDB, we have investigated the frequency of SQSTM1 mutations in different populations and looked for a founder effect on chromosomes bearing SQSTM1 UBA domain mutations.
Materials and Methods: We conducted mutation screening of SQSTM1 and performed haplotype analysis using the PHASE software program in 83 kindreds with familial PDB, recruited mainly through clinic referrals in the United Kingdom, Australia, and New Zealand. Similar studies were conducted in 311 individuals with PDB who did not have a family history and 375 age- and sex-matched controls from the United Kingdom.
Results: The proportion of patients with familial PDB who had SQSTM1 UBA domain mutations varied somewhat between referral centers from 7.1% (Sydney, Australia) to 50% (Perth, Australia), but the difference between centers was not statistically significant. Haplotype analysis in 311 British patients with PDB who did not have a family history and 375 age- and sex-matched British controls showed that two common haplotypes accounted for about 90% of alleles at the SQSTM1 locus, as defined by common single nucleotide polymorphisms (SNPs) in exon 6 (C916T, G976A) and the 3′UTR (C2503T, T2687G). These were H1 (916T-976A-2503C-2687T) and H2 (916C-976G-2503T-2687G). There was no significant difference in haplotype distribution in PDB cases and controls, but the P392L mutation was found on the H2 haplotype in 25/27 cases (93%), which is significantly more often than expected given the allele frequencies in the normal population (odds ratio, 13.2; 95% CI, 3.1-56.4; p &lt; 0.0001). Similar findings were observed in familial PDB, where 12/13 (92%) of P392L mutations were carried on H2 (odds ratio 17.2; 95% CI, 2.2-138; p = 0.001).
Conclusions: These results provide strong evidence for a founder effect of the SQSTM1P392L mutation in PDB patients of British descent, irrespective of family history. Our results imply that these individuals share a common ancestor and that the true rate of de novo mutations may be lower than previously suspected.
Capsaicin-Sensitive Sensory Neurons Contribute to the Maintenance of Trabecular Bone Integrity
Authors: Offley Sarah C , Guo Tian-Zhi , Wei Tzuping , Clark J David , Vogel Hannes , Lindsey Derek P , Jacobs Christopher R , Yao Wei , Lane Nancy E , Kingery Wade S 
Published: April 2006

Abstract
This investigation used capsaicin to selectively lesion unmyelinated sensory neurons in rats. Neuronal lesioning induced a loss of trabecular integrity, reduced bone mass and strength, and depleted neuropeptides in nerve and bone. These data suggest that capsaicin-sensitive sensory nerves contribute to trabecular bone integrity.
Introduction: Familial dysautomia is an autosomal recessive disease in which patients suffer from unmyelinated sensory neuron loss, reduced BMD, and frequent fractures. It has been proposed that the loss of neurotransmitters synthesized by unmyelinated neurons adversely affects bone integrity in this hereditary syndrome. The purpose of this study was to determine whether small sensory neurons are required for the maintenance of bone integrity in rats.
Materials and Methods: Ten-month-old male Sprague-Dawley rats were treated with either capsaicin or vehicle. In vivo DXA scanning and μCT scanning, and histomorphometry were used to evaluate BMD, structure, and cellular activity. Bone strength was measured in distal femoral sections. Body weight and gastrocnemius/soleus weights were measured and spontaneous locomotor activity was monitored. Peroneal nerve morphometry was evaluated using light and electron microscopy. Substance P and calcitonin gene-related peptide (CGRP) content in the sciatic nerve and proximal tibia were determined by enzyme immunoassay (EIA). Substance P signaling was measured using a sciatic nerve stimulation extravasation assay.
Results: Four weeks after capsaicin treatment, there was a loss of BMD in the metaphyses of the tibia and femur. In the proximal tibia, the osteoclast number and surface increased, osteoblast activity and bone formation were impaired, and trabecular bone volume and connectivity were diminished. There was also a loss of bone strength in the distal femur. No changes occurred in body weight, 24-h grid-crossing activity, weight bearing, or muscle mass after capsaicin treatment, indicating that skeletal unloading did not contribute to the loss of bone integrity. Capsaicin treatment destroyed 57% of the unmyelinated sensory axons, reduced the substance P and CGRP content in the sciatic nerve and proximal tibia, and inhibited neurogenic extravasation.
Conclusion: These results support the hypothesis that capsaicin-sensitive sensory neurons contribute to the maintenance of trabecular bone integrity. Capsaicin-sensitive neurons have efferent functions in the tissues they innervate, effects mediated by transmitters released from the peripheral nerve terminals. We postulate that the deleterious effects of capsaicin treatment on trabecular bone are mediated by reductions in local neurotransmitter content and release.
Effect of CYP1A1 Gene Polymorphisms on Estrogen Metabolism and Bone Density
Authors: Napoli Nicola , Villareal Dennis T , Mumm Steven , Halstead Linda , Sheikh Sharmin , Cagaanan Manuel , Rini Giovam Battista , Armamento-Villareal Reina 
Published: April 2006

Abstract
In this study, we evaluated the effect of polymorphisms of the CYP1A1 gene, linked to hormone-related cancers, on estrogen metabolism and BMD. We found that variants carrying the A allele (CA and AA) for the C4887A polymorphism have a significantly higher degree of estrogen catabolism and lower femoral BMD.
Introduction: Polymorphisms of the CYP1A1 gene, one of the key enzymes that metabolize estrogen, have been linked with hormone-related cancers. We investigated the impact of these polymorphisms on estrogen metabolism and BMD, which is another hormone-dependent health issue.
Materials and Methods: One hundred seventy postmenopausal women (mean age, 63.5 ± 0.6 years) participated in the study, but analysis was limited to 156 white women. Genotyping was performed by restriction fragment length polymorphism analysis, urinary estrogen metabolites by enzyme immunoassay, serum estradiol by ultrasensitive radioimmunoassay, serum sex hormone-binding globulin by immunoradiometric assay, and BMD by DXA. Differences in the levels of urinary metabolites and BMD among the different variants were analyzed by analysis of covariance, whereas differences in free estradiol index, urinary N-telopeptide of type 1 collagen (NTx), and bone size were compared by one-way ANOVA.
Results: We found that subjects carrying the A allele (CA or AA) for the C4887A polymorphism of the CYP1A1 gene have significantly lower free estradiol index (0.323 ± 0.08 versus 0.506 ± 0.04; p = 0.04; pmol/nmol) and higher levels of total urinary estrogen metabolites (ng/mg Cr) than CC subjects (27.92 ± 2.03 versus 21.15 ± 1.04; p = 0.03), suggestive of an accelerated estrogen catabolism in these (CA + AA) individuals. They also had significantly lower BMD (g/cm2) in all regions of the femur than subjects with the CC genotype, (total hip: 0.809 ± 0.02 versus 0.865 ± 0.01; neck: 0.671 ± 0.02 versus 0.722 ± 0.01; trochanter: 0.614 ± 0.02 versus 0.656 ± 0.01; and intertrochanter: 0.969 ± 0.03 versus 1.039 ± 0.01; all p &lt; 0.05). No significant effect of this gene polymorphism was detected on lumbar spine BMD. Urinary NTx, a marker for bone resorption, was also significantly higher in the CA + AA compared with the CC variants (186.09 ± 16.15 versus 124.00 ± 11.87 nmol of bone collagen equivalent/mmol of creatinine; p = 0.003). Genotype frequencies for this polymorphism showed CC as the most common genotype (127/156), followed by CA (28/156), whereas AA was rare (1/156).
Conclusion: Women with the A allele seem to have increased estrogen catabolism, as indicated by higher urinary estrogen metabolites and lower free estradiol index. This is associated with increased bone resorption and lower femoral BMD in those with the A allele. Our data, therefore, suggest that, through its effect on the rate of estrogen catabolism, the C4887A polymorphism of the CYP1A1 gene may represent a possible genetic risk factor for osteoporosis.
An Instrument to Measure Skeletal Burden and Predict Functional Outcome in Fibrous Dysplasia of Bone
Authors: Collins Michael T , Kushner Harvey , Reynolds James C , Chebli Caroline , Kelly Marilyn H , Gupta Anurag , Brillante Beth , Leet Arabella I , Riminucci Mara , Robey Pamela Gehron , Bianco Paolo , Wientroub Shlomo , Chen Clara C 
Published: April 2006

Abstract
An instrument to measure skeletal burden in fibrous dysplasia was developed. Biological and clinical relevance was shown by correlating skeletal burden scores with bone markers, quality of life, and ambulatory status. Childhood scores predict adult ambulatory status, and scores were unaffected when bone markers decreased with bisphosphonate treatment or aging.
Introduction: Fibrous dysplasia (FD) is a skeletal disease with a broad clinical expression. There is no objective method to assess the extent of skeletal involvement or predict outcome. We developed an instrument to measure skeletal burden that correlates with physical function, health-related quality of life (HRQL), and ambulatory status.
Materials and Methods: Seventy-nine patients with FD underwent bone scintigraphy. The skeletal burden score was derived from a weighted score based on the regional measurement using bone scintigraphy to estimate the amount of FD in anatomical segments. Six readers scored 20 scans twice to determine the inter- and intrareader agreement. To assess biological significance, scores were correlated with bone markers. To assess functional outcome, scores on the SF-36 (adults) or CHQ-PF50 (children) were correlated with skeletal burden scores. In a group of patients who had bone scans as children and adults (n = 6), the ability to predict ambulatory status was tested. Skeletal burden scores were assessed in patients before and after treatment with pamidronate (n = 5).
Results: The inter- and intrareader agreement of burden scores were r = 0.96, and 0.98, respectively (p &lt; 0.001 for both). The scores correlated with markers of bone metabolism and HRQL (Spearman rho, 0.54-0.67 p &lt; 0.001 and −0.43, p = 0.001, respectively). The mean score of patients who ambulated unassisted was significantly lower than those requiring assistance (p &lt; 0.001 unassisted versus crutch and/or wheelchair). In unassisted ambulators, younger patients had higher scores, suggesting high childhood scores may predict adulthood impairment. In six patients with childhood and adulthood scans, childhood scores &gt;30 predicted assisted ambulation in adulthood. There was a negative correlation between bone markers and age (Spearman rho, −0.42 to −0.70; p &lt; 0.001), but not age and skeletal burden score. Pamidronate treatment decreased serum alkaline phosphatase but had no effect on the skeletal burden score.
Conclusions: This is a validated and reliable instrument for the measurement of skeletal burden of FD and is able to predict functional outcome.
Alveolar Bone Marrow as a Cell Source for Regenerative Medicine: Differences Between Alveolar and Iliac Bone Marrow Stromal Cells
Authors: Matsubara Takehiro , Suardita Ketut , Ishii Masakazu , Sugiyama Masaru , Igarashi Akira , Oda Ryo , Nishimura Masahiro , Saito Masahiro , Nakagawa Keigo , Yamanaka Katsuyuki , Miyazaki Kazuko , Shimizu Masakazu , Bhawal Ujjal K , Tsuji Koichiro , Nakamura Kozo , Kato Yukio 
Published: April 2006

Abstract
We isolated and expanded BMSCs from human alveolar/jaw bone at a high success rate (70%). These cells had potent osteogenic potential in vitro and in vivo, although their chondrogenic and adipogenic potential was less than that of iliac cells.
Introduction: Human bone marrow stromal cells (BMSCs) have osteogenic, chondrogenic, and adipogenic potential, but marrow aspiration from iliac crest is an invasive procedure. Alveolar BMSCs may be more useful for regenerative medicine, because the marrow can be aspirated from alveolar bone with minimal pain.
Materials and Methods: In this study, alveolar bone marrow samples were obtained from 41 patients, 6–66 years of age, during the course of oral surgery. BMSCs were seeded and maintained in culture with 10% FBS and basic fibroblast growth factor. In addition, BMSCs were induced to differentiate into osteoblasts, chondrocytes, or adipocytes in appropriate medium.
Results and Conclusion: From a small volume (0.1–3 ml) of aspirates, alveolar BMSCs expanded at a success ratio of 29/41 (70%). The success rate decreased with increasing donor age, perhaps because of age-dependent decreases in the number and proliferative capacity of BMSCs. The expanded BMSCs differentiated into osteoblasts under osteogenic conditions in 21–28 days: the mRNA levels of osteocalcin, osteopontin, and bone sialoprotein, along with the calcium level, in alveolar BMSC cultures were similar to those in iliac cultures. However, unlike iliac BMSC, alveolar BMSC showed poor chondrogenic or adipogenic potential, and similar differences were observed between canine alveolar and iliac BMSCs. Subsequently, human alveolar BMSCs attached to β-tricalcium phosphate were transplanted into immunodeficient mice. In transplants, new bone formed with osteoblasts and osteocytes that expressed human vimentin, human osteocalcin, and human GAPDH. These findings suggest that BMSCs have distinctive features depending on their in vivo location and that alveolar BMSCs will be useful in cell therapy for bone diseases.
Expression of Runx2/Cbfa1/Pebp2αA During Angiogenesis in Postnatal Rodent and Fetal Human Orofacial Tissues
Authors: Bronckers Antonius LJJ , Sasaguri Kenichi , Cavender Adriana C , D'Souza Rena N , Engelse Marten A 
Published: April 2006

Abstract
Transient expression of Runx2 is reported in endothelial cells and vascular smooth muscle cells during vessel formation in skin, stroma of forming bones and developing periodontal ligament, developing skeletal muscle cells, and fat tissue. The data suggest that Runx2 is expressed in a multipotential mesenchymal cell population that gives rise to various osseous and nonosseous cell lineages.
Introduction: Runx2/Cbfa1 is a transcription factor essential for cells of osteogenic and dentinogenic lineages. Here we examined expression of Runx2/Cbfa1 (all isotypes) in several nonskeletal cell types present in developing orofacial tissues of neonatal rodents and human fetuses with special emphasis on vessel formation.
Materials and Methods: Sections obtained from heads or jaws of postnatal mice, hamster, and human fetuses were immunostained with monoclonal anti-Pebp2aA antibody. Mouse and human tissues were also examined by in situ hybridization. Sections of Runx2 null mutant mice with a LacZ reporter construct inserted in the Runx2 locus were stained for Runx2 promoter activity with anti-galactosidase.
Results: We found transient mRNA and protein expression in endothelial cells and in vascular smooth muscle cells of forming vessels in skin, alveoli of forming bone, and forming periodontal ligament. We also noticed weak and variable expression in some fibroblasts of embryonic skin, early differentiating cross-striated muscle cells, and differentiating fat cells.
Conclusion: Runx2 is not an exclusive marker for chondrogenic, osteogenic, and dentinogenic tissues, but is much more widely present in an early multipotential mesenchymal cell population that gives rise to several other lineages.