Association Between Single-Nucleotide Polymorphisms in the SEC8L1 Gene,Which Encodes a Subunit of the Exocyst Complex,and Rheumatoid Arthritis in a Japanese Population

To identify rheumatoid arthritis (RA) susceptibility genes in a Japanese population by conducting a large-scale case-control association analysis and linkage disequilibrium (LD) mapping on chromosome 7q31-34, a candidate susceptibility locus identified in a preliminary genome-wide scan in 53 Japanese families, using single-nucleotide polymorphisms (SNPs). We prepared 728 dense, evenly spaced SNPs with a minor allele frequency >0.15 in each gene locus on chromosome 7q31-34. Using these SNPs, a 2-stage case-control analysis was performed on 760 RA patients (157 men and 603 women) and 806 non-RA controls (189 men and 617 women). Haplotypes and LD mapping results were assessed based on SNP genotypes in 380 controls. Forty-eight SNPs showed allele associations (P < 0.05) in the first set of DNA samples (380 RA cases and 380 non-RA controls; first-stage analysis). For 4 of the SNPs in the SEC8L1 gene, the association was replicated (P < 0.05) in the second, independent set of DNA samples (an additional 380 RA cases and 380 non-RA controls; second-stage analysis). When data from the 2 groups were combined, the most significant allele association was observed with SNP 441, an intronic SNP of the SEC8L1 gene (P = 0.000059). The SEC8L1 SNPs with significant allele associations were all located in a single conserved LD block (block 4). Haplotype analysis revealed the disease-risk (P = 0.0015) and disease-protective (P = 0.0000062) haplotypes. Resequencing of coding exons within block 4 did not identify any nonsynonymous SNPs. Real-time quantitative polymerase chain reaction revealed that SEC8L1 was expressed ubiquitously in human tissues, including fibroblast-like synoviocytes from RA patients. Our locus-wide association and LD analyses identified intronic SNPs and haplotypes in the SEC8L1 gene that are strongly associated with RA. We propose that SEC8L1, which encodes a component of the exocyst complex, is a candidate susceptibility gene for RA in the Japanese population.


Differential Expression of VEGF Isoforms and VEGF Receptors in Cartilaginous Tumors

Vascular endothelial growth factor (VEGF), which is known to have at least five isoforms and four receptors, is integral to tumor-induced neovascularization. In order to determine whether VEGF signaling is modulated in the development of cartilaginous tumors, we analyzed osteochondrogenic tumors for the expression of VEGF isoforms and VEGF receptors using the reverse transcription-polymerase chain reaction method. Although mRNA for VEGF121, VEGF165, VEGFR-1 and NRP-2 was widely expressed, mRNA expression for VEGF189, VEGFR-2 and NRP-1 was linked to a malignant phenotype such as local invasion. These results indicated that VEGF signaling was fine-tuned by the differential expression of the VEGF isoforms and VEGF receptors.


Athletes With Unilateral Spondylolysis Are at Risk of Stress Fracture at the Contralateral Pedicle and Pars Interarticularis --- A Clinical and Biomechanical Study

Unilateral spondylolysis is common in youths; its clinical and biomechanical features, especially effects on the contralateral side, are not fully understood. Unilateral spondylolysis predisposes the contralateral side to stress fracture, especially in athletes actively engaged in sporting activities involving torsion of the trunk. Case series and descriptive laboratory study. Thirteen athletes younger than age 20 with unilateral spondylolysis were included. The contralateral pedicle and pars of spondylolytic vertebrae were examined using computed tomography and magnetic resonance imaging. Using a finite element model of the intact ligamentous L3-S1 segment, stress distributions were analyzed in response to 400-N axial compression and 10.6-N.m moment in flexion, extension, lateral bending, and axial rotation. Unilateral spondylolysis was created in the model at L5. The stress results from the unilateral defect model were compared to the intact model predictions and correlated to the contralateral defects seen in patients. Among 13 patients, there were 6 early-, 2 progressive-, and 5 terminal-stage defects. Three (23.1%) showed contralateral stress fracture. Among them, 2 belonged to the progressive-stage and 1 to the terminal-stage spondylolysis group. The remaining 4 patients in the terminal defect group showed stress reactions, such as sclerosis at the contralateral pedicle. In the finite element analysis model with an L5 left spondylolysis, the stresses at the contralateral and pars interarticularis were found to increase in all loading modes, with increases as high as 12.6-fold compared to the intact spine. Unilateral spondylolysis could lead to stress fracture or sclerosis at the contralateral side due to an increase in stresses in the region. Surgeons should be aware of possibility of contralateral stress fractures in cases in which patients, especially athletes engaged in active sports, show unilateral spondylolysis and persistent low back pain complaints.


Spondylolysis fracture angle in children and adolescents on CT indicates the facture producing force vector A biomechanical rationale.


Development of Autoimmune Arthritis With Aging Via Bystander T Cell Activation in the Mouse Model of Sjogren's Syndrome

A wide spectrum of extraglandular manifestations may occur in patients with Sjogren's syndrome (SS), but the mechanisms responsible for in vivo progression are still obscure. We undertook this study to evaluate the age-related changes during the development of extraglandular autoimmune lesions, including arthritis, in the murine model of primary SS, and to evaluate the possible relationship between age-related disturbance of activation-induced cell death and the in vivo kinetics against autoantigens. A total of 126 NFS/sld mice were investigated at ages 2, 4, 6, 10, 12, 18, 20, and 24 months. Cytokine production was tested using culture supernatants from anti-CD3 monoclonal antibody-stimulated T cells. Anti-single-stranded DNA (anti-ssDNA) antibodies, Ig isotypes (IgG1, IgG2a), rheumatoid factor (RF), and anti-type II collagen (anti-CII) antibodies were detected by enzyme-linked immunosorbent assay. Proliferative T cell responses against each of 3 recombinant alpha-fodrin proteins and against CII were analyzed. Autoimmune arthritis developed in SS model mice until age 24 months. Significant elevations in serum levels of RF, anti-ssDNA antibodies, and anti-CII antibodies were found in aging SS model mice. A high titer of serum autoantibodies against alpha-fodrin fragments (containing different epitopes that were originally identified in primary SS model mice) was frequently detected in young and aged SS model mice. Moreover, we found that alpha-fodrin autoantigen induced Th1 immune responses and accelerated disturbance of Fas-mediated T cell apoptosis in aged SS model mice. These results indicate that age-related disturbance of activation-induced cell death via bystander T cell activation may play a crucial role in the development of autoimmune arthritis in a murine model of SS.


Influence of age on scapulo-thoracic orientation

Scapular activity during shoulder motion is critical for normal shoulder function. With aging, muscle function deteriorates in almost all people, which may lead to shoulder impingement syndrome. Forty-four normal subjects, 23 men and 21 women aged from 16 to 73 years with a mean age 48, were enrolled in the study. Static antero-posterior radiography at both 0 degrees and 90 degrees of abduction were undertaken and correlation between age and scapular orientations were evaluated by Pearson's correlation coefficient test. The purpose of this study is to investigate the relationship between aging and scapulo-thoracic orientation. Significant correlation coefficients were observed between aging and scapular orientations. With the shoulder at 0 degrees abduction, posterior tilt showed significant negative correlation with aging. At 90 degrees abduction, both posterior tilt and upward rotation angle correlated negatively with aging. The correlation was apparent at 90 degrees abduction. The results indicate that shoulder aging closely relates to changes of scapular orientation, which consist of decreases of the posterior tilt at 0 degrees and 90 degrees abduction and the upward rotation angle at 90 degrees. The current study indicated that one of the effects of aging on the shoulder is a decrease of posterior tilt and upward rotation angle as seen in an abducted position; and that these alterations are similar to the scapular kinematics of shoulder impingement syndrome. By taking this concept into consideration, the effects of aging on shoulder kinematics can be appropriately evaluated.


Continuous muscle stretch prevents disuse muscle atrophy and deterioration of its oxidative capacity in rat tail-suspension models

The purpose of this study was to evaluate the effect of continuous muscle stretch on disuse-atrophied muscles. Sprague-Dawley rats were used and divided into five groups: control group, hind limb suspended for 3 and 7 days, and hind-limb suspension plus strenuous continuous muscle stretch for 3 and 7 days. In the hind-limb suspension plus strenuous continuous muscle stretch groups, the gastrocnemius-plantaris-soleus muscles were stretched using a plastic plate that immobilized the ankle joint at the maximum dorsal flexed position during the hind-limb suspension period. The intracellular energy metabolism of the working muscle during electric stimulation was evaluated by phosphorus-31 magnetic resonance spectroscopy in vivo. Changes in phosphocreatine, inorganic phosphate, and the intracellular pH were monitored to evaluate intramuscular oxidative capacity. Maximum tension and muscle wet mass were also measured. The oxidative capacity, muscle wet weight, and maximum tension decreased after hind-limb suspension. The muscle oxidative capacity at control levels was maintained during the first 3 days in muscles subjected to continuous strenuous stretch. It was also effective to prevent the decrease in muscle mass and maximum twitch tension during the initial 3 days. However, the effects did not persist. Continuous strenuous stretch was effective to prevent disuse muscle atrophy and its functional deterioration; however, its effects did not last long.

American Journal of Physical Medicine & Rehabilitation


Evolution of understanding of genetics of Paget's disease of bone and related diseases


Relationship Between Cathepsin B and Thrombin in Rheumatoid Arthritis

To investigate the pathophysiological significance of cathepsin B and thrombin in synovial fluid (SF) from patients with rheumatoid arthritis (RA). Thrombin and cathepsin B activities of samples from patients with RA and osteoarthritis (OA) were measured using fluorogenic synthetic substrates. The concentration of interleukin 8 (IL-8) in SF was measured by ELISA. The effect of thrombin on the proliferation of synovial fibroblast-like cells (SFC) was examined by measuring 3H-thymidine incorporation. The effect of thrombin on the release of IL-8 and cathepsin B from SFC was investigated. The expression of IL-8 mRNA in SFC after stimulation with thrombin was evaluated using real-time quantitative RT-PCR. The effect of recombinant IL-8 on the activation of cathepsin B was examined using the knee joints of rabbits. In SF supernatants, cathepsin B and thrombin-like activity was significantly higher in RA than in OA, and there was a significant correlation between them. Cathepsin B activity was also significantly higher in SF cells and synovial tissue extracts from RA patients than in those from OA patients. There was a significant correlation between cathepsin B activity and the concentration of IL-8 in RA SF. Thrombin enhanced the proliferation of SFC in a dose-dependent manner. Thrombin significantly enhanced the release of IL-8 from SFC as well as the expression of IL-8 mRNA in SFC. IL-8 induced activation of cathepsin B in the knee joints of rabbits. However, thrombin did not directly increase cathepsin B activity in SFC. In RA, thrombin was found to be related to the enhanced growth of SFC and the release of IL-8 from these cells; thus thrombin is probably related to worsening of inflammation through the recruitment of leukocytes (neutrophils), which release cathepsin B into the SF. Thrombin can induce activation of cathepsin B in SFC via increased expression of IL-8.


Vertebral forward slippage in immature lumbar spine occurs following epiphyseal separation and its occurence is unrelated to disc degeneration. Is the pediatric spondylolisthesis a physis stress fracture of vertebral body?

Radiographic and histologic evaluation of a rat model of lumbar spine slippage. To clarify the pathomechanism of slippage in the immature spine. There are controversial hypotheses regarding the pathogenesis of slippage of the pediatric spine with pars defects. Some studies supported that disc degeneration was its cause, while others indicated the growth plate injury was the cause. An immature lumbar spine slippage model in 4-week-old rats was used. Following posterior destabilizing surgery, the lumbar spine was radiographically and histologically examined at 1, 3, 5, and 7 days after surgery. Radiographically, slippage occurred about 7% in the % slip on day 7, and no slippage was observed before day 5. Histologically, epiphyseal separation also appeared on day 7; before day 5, the growth plate showed no abnormalities. Within 7 days after the operation, the anulus fibrosus did not show any sign indicating degeneration. The nucleus pulposus was also normal up to day 7. The findings of this study support the hypothesis that vertebral forward slippage of the immature spine occurs following epiphyseal separation and its occurrence is unrelated to disc degeneration.


Union of defects in the pars interarticularis of the lumbar spine in children and adolescents. Radiological outcome after conservative treatment.

Lumbar spondylolysis can heal with conservative treatment, but few attempts have been made to identify factors which may affect union of the defects in the pars. We have evaluated, retrospectively, the effects of prognostic variables on bony union of pars defects in 134 young patients less than 18 years of age with 239 defects of the pars who had been treated conservatively. All patients were evaluated by CT scans when first seen and more than six months later at follow-up. The results showed that the spinal level and the stage of the defects were the predominant factors. The site of the defects in the pars, the presence or development of spondylolisthesis, the condition of the contralateral pars, the degree of lumbar lordosis and the degree of lumbar inclination all significantly affected union.

The Journal of Bone and Joint Surgery. British Volume


Skeletal muscle gene expression in space-flown rats

Skeletal muscles are vulnerable to marked atrophy under microgravity. This phenomenon is due to the transcriptional alteration of skeletal muscle cells to weightlessness. To further investigate this issue at a subcellular level, we examined the expression of approximately 26,000 gastrocnemius muscle genes in space-flown rats by DNA microarray analysis. Comparison of the changes in gene expression among spaceflight, tail-suspended, and denervated rats revealed that such changes were unique after spaceflight and not just an extension of simulated weightlessness. The microarray data showed two spaceflight-specific gene expression patterns: 1) imbalanced expression of mitochondrial genes with disturbed expression of cytoskeletal molecules, including putative mitochondria-anchoring proteins, A-kinase anchoring protein, and cytoplasmic dynein, and 2) up-regulated expression of ubiquitin ligase genes, MuRF-1, Cbl-b, and Siah-1A, which are rate-limiting enzymes of muscle protein degradation. Distorted expression of cytoskeletal genes during spaceflight resulted in dislocation of the mitochondria in the cell. Several oxidative stress-inducible genes were highly expressed in the muscle of spaceflight rats. We postulate that mitochondrial dislocation during spaceflight has deleterious effects on muscle fibers, leading to atrophy in the form of insufficient energy provision for construction and leakage of reactive oxygen species from the mitochondria.


Muscular oxidative capacity in ovariectomized rats discussion on the endurance performance of female athletes with sports-related-amenorrhea


Development of Autoimmune Exocrinopathy Resembling Sjogren's Syndrome in Adoptively Transferred Mice With Autoreactive CD4+ T Cells

The pathologic mechanisms responsible for organ-specific tissue damage in primary Sjögren's syndrome (SS) remain unclear, but it has been suggested that the pathology is mediated by autoreactive CD4+ T cells infiltrating the salivary and lacrimal glands. This study was undertaken to investigate whether alpha-fodrin autoantigen-specific autoreactive CD4+ T cells are capable of inducing autoimmune lesions. A total of 45 synthetic alpha-fodrin peptides designed to be 20 amino acid residues in length were generated. To establish an autoreactive T cell line, limiting dilution analysis (LDA) was performed on lymph node cells (LNCs) in the presence of alpha-fodrin peptides. The effects of adoptive transfer of autoreactive CD4+ T cells into normal syngeneic recipients were investigated. Autoreactive CD4+ T cell lines that recognize synthetic alpha-fodrin peptide, which produced Th1 cytokines and showed cytotoxic activities, were established in a murine model for SS. T cell receptor V(beta) usage and third complementarity-determining region (CDR3) sequences indicated that in some cases V(beta)6-CDR3 genes matched between the tissue-infiltrating T cells and the autoreactive T cell lines. Adoptive transfer of the autoreactive CD4+ T cells into normal syngeneic recipients induced autoimmune lesions quite similar to those of SS. Our data help to elucidate the pathogenic mechanisms responsible for tissue destruction in autoimmune exocrinopathy and indicate that autoreactive CD4+ T cells play a pivotal role in the development of murine SS.


Intracapsular hip fractures in patients with rheumatoid arthritis

We reviewed the treatment of 43 patients with rheumatoid arthritis and femoral neck fracture. Patients' average age was 66.4 (36-80) years and average duration of RA was 20.3 (4-42) years. Thirteen patients were treated with primary total hip arthroplasty (THA), and the clinical results were comparable to patients treated conservatively or by osteosynthesis. Eighteen patients were treated with primary bipolar hip prosthesis and after an average of 6.1 (1-13) years there was no acetabular destruction. However, long-term results were inferior to patients treated with THA. Nine patients were treated with osteosynthesis, of which two later had a hip prosthesis. Three cases with impacted fractures were treated conservatively with successful union in all.


Ewing Sarcoma of the Pelvis Treated with Internal Hemipelvectomy:A Cace Report

The Journal of the Chugoku-Shikoku Orthopaedic Association

中国・四国整形外科学会雑誌


Three successive stress fractures at the same vertebral level in an adolescent baseball player


The Pathogenesis of Slippage and Deformity in the Pediatric Lumbar Spine --- A Radiographic and Histologic Study using a New Rat In Vivo Model


A new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis. Technical note

The authors describe a new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis. Short-term clinical outcome was evaluated. Surgery-related indications were: 1) radiculopathy without low-back pain; 2) no spinal instability demonstrated on dynamic radiographs; and 3) age older than 40 years. Seven patients, four men and three women, fulfilled these criteria and underwent endoscopic decompressive surgery. Their mean age was 60.9 years (range 42-70 years). No subluxation was present in four patients, whereas Meyerding Grade I slippage was demonstrated in three. For endoscopic decompression, a skin incision of 16 to 18 mm in length was made, and fenestration was performed to identify the affected nerve root. The proximal stump of the ragged edge of the spondylotic lesion, and the fibrocartilaginous mass compressing the nerve root were removed. The follow-up period ranged from 6 to 22 months (mean 11.7 months). Clinical outcome was evaluated using Gill criteria; in three patients the outcome was excellent, and in four it was good. This new endoscopic technique was useful in the decompression of nerve roots affected by spondylolysis, the technique was minimally invasive, and the clinical results were acceptable.


Electrical Stimulation Prevents Deterioration of the Oxidative Capacity of Disuse-Atrophied Muscles in Rats

The purpose of this study was to evaluate the effects of electrical stimulation on disuse-atrophied muscles. Sprague-Dawley rats were used and divided into three groups: control (C), hind-limb suspended for 7 d (HS), and HS plus transcutaneous electrical stimulation for 7 d (ES). In the ES group, transcutaneous electrical stimulation was induced at 1 Hz for 1 h every day to condition the gastrocnemius-plantaris-soleus muscles. Muscle oxidative capacity was evaluated by 31P-MRS in vivo. Maximum tension and muscle wet mass were also measured. Muscle oxidative capacity decreased within 1 wk in HS; however, it was maintained when electric stimulation was applied to the suspended limb. The maximum twitch tension in HS was significantly smaller than that in C (p < 0.05), while in ES it did not differ from that in C. The muscle mass was significantly smaller in the HS and ES groups compared to C (p < 0.05). These data indicated that twitch electrical stimulation was effective in preventing deterioration of muscle functions, such as maximum tension and oxidative capacity, induced by 1 wk of disuse.

Aviation, Space, and Environmental Medicine


Cartilage-Specific overexpression of C-propeptide of type collagen affected matrix mineralization in transgenic mice


Mice lacking the EDB segment of fibronectin develop normally but exhibit reduced cell growth and fibronectin matrix assembly in vitro

Fibronectins (FNs) are major cell-adhesive proteins in the extracellular matrix and are essential for embryonic development. FNs are encoded by a single gene, but heterogeneity is introduced by alternative pre-mRNA splicing. One of the alternatively spliced segments, extra domain B (EDB), is prominently expressed during embryonic development and in tumor tissues, although it is mostly eliminated from FN in normal adult tissues. To examine the function of the EDB segment in vivo, we generated mice lacking the EDB exon using the Cre-loxP system. Although EDB-containing FNs are highly expressed throughout early embryogenesis, EDB-deficient mice developed normally and were fertile. Despite the absence of any significant phenotypes observed in vivo, however, fibroblasts obtained from EDB-deficient mice grew slowly in vitro and deposited less FN in the pericellular matrix than fibroblasts from wild-type mice. These results indicate that expression of EDB-containing isoforms is dispensable during embryonic development, yet may play a modulating role in the growth of connective tissue cells via the FN matrix.


Cyclooxygenase-2 Inhibitor Inhibits the Fracture Healing

骨折後の治療期間に及ぼす麻酔薬の影響を調べるため，麻酔を投与したラットと投与しなかったラットの大腿骨を用い，骨折後の時間経過に伴う骨の強度，剛性の測定を行った．その結果，麻酔薬を用いることで骨の強度および剛性の回復が遅れることを示した．

Journal of Physiological Anthropology and Applied Human Science


Intergenerational comparison of total and regional bone mineral density and soft tissue composition in Japanese women without vertebral fractures

We measured total and regional bone mineral density (BMD) and soft tissue mass in 115 healthy Japanese women without vertebral fractures. The subjects, aged 20 to 75 years, were divided into four age groups: 20's to 40's group (n=33), 50's group (n=26), 60's group (n=26), and 70's group (n=30). BMD was measured by dual energy X-ray absorptiometry (DXA). The evaluated regions were the head, arms, legs, ribs, thoracic vertebrae, lumbar vertebrae and pelvis. The total and regional BMDs were the highest in the 20's to 40's group, and they decreased with age, and reached their respective lowest values in the 70's group. The decrease in BMDs of the spine and pelvis was the most prominent of all regional BMDs. Total and regional lean mass and fat mass were the highest in the 20's to 40's group, and they decreased to their respective lowest values in the 70's group. The results showed that the decrease in BMD of the spine and pelvis was the most prominent of all regional BMDs associated with a decrease in the total and regional lean mass and total and regional fat mass.

The Journal of Medical Investigation : JMI


Use of intercostal nerves for neurotization of the musculocutaneous nerve in infants with birth-related brachial plexus palsy

The use of intercostal nerves (ICNs) for the neurotization of the musculocutaneous nerve (MCN) in adult patients with traumatic brachial plexus palsy has been well described. However, its use for brachial plexus palsy in infants has rarely been reported. The authors surgically created 31 ICN-MCN communications for birth-related brachial plexus palsy and present the surgical results. Thirty-one neurotizations of the MCN, performed using ICNs, were conducted in 30 patients with birth-related brachial plexus palsy. In most cases other procedures were combined to reconstruct all upper-extremity function. The mean patient age at surgery was 5.8 months and the mean follow-up period was 5.2 years. Intercostal nerves were transected 1 cm distal to the mammary line and their stumps were transferred to the axilla, where they were coapted directly to the MCN. Two ICNs were used in 26 cases and three ICNs in five cases. The power of the biceps muscle of the arm was rated Grade M4 in 26 (84%) of 31 patients. In the 12 patients who underwent surgery when they were younger than 5 months of age, all exhibited a grade of M4 (100%) in their biceps muscle power. These results are better than those previously reported in adults. Neurotization of the MCN by surgically connecting ICNs is a safe, reliable, and effective procedure for reconstruction of the brachial plexus in patients suffering from birth-related palsy.


A RUNX2/PEBP2alpha A/CBFA1 mutation displaying impaired transactivation and Smad interaction in cleidocranial dysplasia.

Cleidocranial dysplasia (CCD), an autosomal-dominant human bone disease, is thought to be caused by heterozygous mutations in runt-related gene 2 (RUNX2)/polyomavirus enhancer binding protein 2alphaA (PEBP2alphaA)/core-binding factor A1 (CBFA1). To understand the mechanism underlying the pathogenesis of CCD, we studied a novel mutant of RUNX2, CCDalphaA376, originally identified in a CCD patient. The nonsense mutation, which resulted in a truncated RUNX2 protein, severely impaired RUNX2 transactivation activity. We show that signal transducers of transforming growth factor beta superfamily receptors, Smads, interact with RUNX2 in vivo and in vitro and enhance the transactivation ability of this factor. The truncated RUNX2 protein failed to interact with and respond to Smads and was unable to induce the osteoblast-like phenotype in C2C12 myoblasts on stimulation by bone morphogenetic protein. Therefore, the pathogenesis of CCD may be related to the impaired Smad signaling of transforming growth factor beta/bone morphogenetic protein pathways that target the activity of RUNX2 during bone formation.

Proceedings of the National Academy of Sciences of the United States of America


Congenital transverse deficiency of the tibia and fibula

We report two similar, but unrelated, patients with congenital bilateral partial deficiencies of the tibia and fibula associated with intact feet. In both patients, the tibia and fibula were absent on initial radiographs, while the femur and the tarsal bones were well developed and there was bilateral teratologic dislocation of the hips. Ultrasound and magnetic resonance imaging (MRI) studies suggested the presence of cartilaginous remnants of the tibia and fibula. There were multidirectional instabilities in the knees and ankles. The clinical and radiological features of these cases are distinct from those of congenital longitudinal deficiency of the tibia, in which the fibula is always preserved, and from longitudinal deficiency of the fibula, in which the tibia is present and the foot is usually involved. We suggest that the bilateral partial deficiencies of the tibia and fibula associated with the intact foot and teratologic dislocation of the hips is a single-entity disorder, possibly categorized as an intercalary transverse deficiency of the lower limb.


PEBP2aA/CBFA1 mutations in Japanese cleidocranial dysplasia patients.

Cleidocranial dysplasia (CCD) is an autosomal dominant human bone disease whose genetic locus has been located on chromosome 6p21, where the PEBP2alphaA/CBFA1 gene essential for osteogenesis also maps. Previously, several heterozygous mutations in PEBP2alphaA/CBFA1 were found in CCD patients. In this study, we identified six different types of mutations in PEBP2alphaA/CBFA1 in Japanese CCD patients. Four cases were similar to those reported previously: two were nonsense mutations in the Runt domain, one was a hemizygous deletion, and the other was a missense mutation in the Runt domain which abolished the DNA-binding activity of Runx2/PEBP2alphaA/CBFA1. The remaining two mutations were novel: one had a heterozygous gt-to-tt mutation at the splice donor site (gt) between the exon3-intron junction, which resulted in abnormal exon3 skipping, and the other had a mutation in exon7, which led to the introduction of a translational stop codon in the middle of the transactivation domain. Thus, defects in either the DNA-binding domain or transactivation domain of Runx2/PEBP2alphaA/CBFA1 can cause CCD. The results not only provide a strong genetic evidence that mutations involving in PEBP2alphaA/CBFA1 contribute to CCD, but also provide a useful tool to study how Runx2/PEBP2alphaA/CBFA1 plays its pivotal role during osteoblastic differentiation.


Novel mutations of the cathepsin K gene in patients with pycnodysostosis and their characterization.

Pycnodysostosis is a rare autosomal recessive skeletal dysplasia characterized by short stature, osteosclerosis, acroosteolysis, bone fragility, and skull deformities. Recently, mutations in the gene encoding cathepsin K (CK), a lysosomal cysteine protease localized exclusively in osteoclasts, were found to be responsible for this disease. We analyzed genomic DNA from four unrelated Japanese patients with this disorder and identified three different mutations of their CK genes: a previously reported missense mutation (A277 V), a novel single base deletion mutation (531 del T) causing a frame shift from codon 142 that results in a premature termination codon, and a novel missense mutation (L9P) in the signal peptide region. To investigate whether the L9P mutation disrupts signal peptide function and decreases protein synthesis, mutant and wild-type CK complementary DNAs driven by the cytomegalovirus promoter were transfected into COS-7 cells, and their gene products were detected by immunohistochemistry and Western blotting. Expression of the mutant protein was markedly reduced, suggesting decreased mature CK production in this patient, which may have been due to dysfunction of the signal peptide. These results provide evidence that a structural change in the signal peptide of the CK protein was involved in the pathogenesis of pycnodysostosis.

The Journal of Clinical Endocrinology and Metabolism


Oberarm verlangerungen und Deformitatenkorrektur (Humeral lngthening and deformity correction)


Mechanical tension-stress induces gene expression of BMP-2 and -4, but not of BMP-6, -7 and GDF-5, during bone lengthening by distraction osteogenesis


Treatment Strategy for Congenital Pseudarthrosis of the Tibia

難治性小児疾患の治療戦略 先天性下腿偽関節症の治療戦略(解説)

The Journal of the Japanese Orthopaedic Association