Reapplication of the Pavlik Harness for Treatment of Developmental Dysplasia of the Hip After Initial Pavlik Harness Failure.

OBJECTIVE: The Pavlik harness (PH) has been widely used as the standard treatment for infants with developmental dysplasia of the hip (DDH). When the initial application of the PH fails, alternative treatments, such as closed reduction, open reduction, and reapplication of the PH will be considered. Compared with other treatments, reapplication of the PH offers certain advantages, including simplicity and reduced physical, and psychological stress, on both infants and caregivers. This study aims to investigate the effectiveness of reapplying the PH in patients with DDH. METHODS: This study included patients with DDH (complete dislocation) who were treated by reapplication of PH between 1988 and 2012. Patients who were able to follow-up for more than 5 years were included. We examined the reduction rate and several factors to identify indicators associated with successful reduction during reapplication, including age, sex, side of hip dislocation, and the presence of the Ortolani sign. At the final follow-up, hip development was assessed using the Severin classification, whereas avascular necrosis (AVN) was evaluated using the Kalamchi classification and the Salter criteria. RESULTS: A total of 56 patients (48 females and 8 males) and 57 hips were included in this study. The mean age at first and second application of PH was 4.2 months old (range: 0.12 to 6.4), and 5.8 months old (3.0 to 11.4), respectively. The reduction rate was 49% (28 out of 57 hips). Among the successfully reduced hips, the AVN rate was 3.6% (1 out of 28 hips). The Severin classification revealed 27 hips in class I and 1 hip in class III. Statistical analysis indicated a significantly higher proportion of left hip involvement in the reduction group (85% vs 41%, χ 2 test, P < 0.001). Although not statistically significant, the rate of positive Ortolani sign tended to be higher in the reduction group (61% vs 38%, χ 2 test, P = 0.06). CONCLUSION: The reapplication method demonstrated a 49% reduction rate and a low AVN rate of 3.6% in our study. It is worth considering for patients who fail the initial PH treatment, particularly in cases of left-side dislocation and a positive Ortolani sign during the initial application.

Radiologic Changes After 10 Years Postreduction in Developmental Dysplasia of the Hip Treated With Different Reduction Methods and Risk Factors for Osteoarthritis.

BACKGROUND: This study examined how radiologic indices at 10 years postreduction change over time and influence the final outcome through a comparative study of 3 reduction methods for developmental dysplasia of the hip, including the Pavlik harness, closed reduction, and open reduction (OR). METHODS: Patients treated from 1990 to 2000 for dysplasia of the hip and followed up for >20 years were included in this study. Radiologic indices at 10 years postreduction and final follow-up (average 24 years postreduction) were measured in the 3 groups. The relative joint space of <66% compared with the healthy side was defined as positive osteoarthritis (OA) at the final follow-up. The relationship between OA and factors such as age, sex, method of reduction, radiologic indices, and Severin and Kalamchi classifications at 10 years postreduction were examined. Clinical evaluation was performed using the modified Harris Hip Score; a score of ≥80 was defined as good performance at the final follow-up. RESULTS: Sixty-five patients (totaling 74 hips) were included. There were no significant differences in radiologic indices between the 10-year postreduction time and final follow-up. Excluding 9 bilateral patients, based on the relative joint space, 21% of the patients (13/56 hips), were positive for OA. Univariate analysis showed that the incidence of positive OA was significantly associated with OR and Kalamchi grade 4 at 10 years postreduction. The modified Harris Hip Score was 80 or higher in 90% of the cases at the final follow-up. CONCLUSIONS: No significant changes in hip morphology were observed at 10 years postreduction. The Kalamchi classification at 10 years postreduction and OR were significantly associated with the incidence of OA at the final follow-up. Therefore, patients who undergo OR and/or display Kalamchi grade 4 have a high risk of developing OA and would require individual instructions for their daily lives to prevent further progression of OA and longer follow-up. LEVEL OF EVIDENCE: Level Ⅲ-case-control study.

A cross-sectional study evaluating patients' preferences for Salter innominate osteotomy.

BACKGROUND: Residual acetabular dysplasia in children after reduction of hip dislocation is often treated using Salter innominate osteotomy to prevent future osteoarthritis. Preventive surgery for asymptomatic patients, which could result in overtreatment, should be carefully applied with consideration of patients' opinions. In this study, we aimed to describe opinions on Salter innominate osteotomy as preventive surgery for children among adult patients who had undergone periacetabular osteotomy for hip pain due to hip dysplasia. METHODS: A mail-in questionnaire survey was conducted with 77 patients who underwent periacetabular osteotomy. Participants responded whether they would recommend Salter innominate osteotomy as preventive surgery for children and the reason for their opinion. We also performed a patient-based evaluation using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and assessed clinical outcome measures with the Japanese Orthopedic Association score. Their recommendations and reasons were evaluated, and associations between their opinions and demographic and clinical characteristics were analyzed. RESULTS: Forty-three patients (56%) responded to the questionnaire. Of these, 10 (23%) patients recommended undergoing Salter innominate osteotomy, 28 (65%) patients did not, and 5 (12%) patients responded they were undecided. No significant association was observed between their opinions and demographic/clinical characteristics evaluated in the survey. The most frequent reason for why they do not recommend Salter innominate osteotomy was related to uncertainty about future hip pain. CONCLUSIONS: In total, 65% of the study participants did not recommend Salter innominate osteotomy for children with risk of dysplasia in the future. Participants' preferences regarding preventive surgery were not influenced by demographic and clinical characteristics.

Bi-allelic CSF1R Mutations Cause Skeletal Dysplasia of Dysosteosclerosis-Pyle Disease Spectrum and Degenerative Encephalopathy with Brain Malformation.

Colony stimulating factor 1 receptor (CSF1R) plays key roles in regulating development and function of the monocyte/macrophage lineage, including microglia and osteoclasts. Mono-allelic mutations of CSF1R are known to cause hereditary diffuse leukoencephalopathy with spheroids (HDLS), an adult-onset progressive neurodegenerative disorder. Here, we report seven affected individuals from three unrelated families who had bi-allelic CSF1R mutations. In addition to early-onset HDLS-like neurological disorders, they had brain malformations and skeletal dysplasia compatible to dysosteosclerosis (DOS) or Pyle disease. We identified five CSF1R mutations that were homozygous or compound heterozygous in these affected individuals. Two of them were deep intronic mutations resulting in abnormal inclusion of intron sequences in the mRNA. Compared with Csf1r-null mice, the skeletal and neural phenotypes of the affected individuals appeared milder and variable, suggesting that at least one of the mutations in each affected individual is hypomorphic. Our results characterized a unique human skeletal phenotype caused by CSF1R deficiency and implied that bi-allelic CSF1R mutations cause a spectrum of neurological and skeletal disorders, probably depending on the residual CSF1R function.

Single Versus Combined Procedures for Severely Involved Legg-Calvé-Perthes Disease.

BACKGROUND: The concept of containment as an effective approach to reduce the risk of femoral head deformity has been questioned because modest results have been achieved after nonoperative and operative treatments for severely involved Legg-Calvé-Perthes disease. Several reports have shown the limited effectiveness of some conventional single procedures. However, there is limited data on the effectiveness of combined procedures. METHODS: The surgical group comprised 77 patients (mean age 8.3 y) and involved 79 hips. The average follow-up term was 9.5 years. Sixty-five patients were unilaterally involved and 12 patients were bilaterally involved (although 10 of the latter patients only received surgery on 1 hip). Among patients, 28 hips were classified as Herring class B/C border (>8 y old) and 51 hips were Herring class C. The 79 hips were divided into 2 treatment groups for further analysis: group 1, single procedures (femoral varus osteotomy) (n=47); group 2, combined procedures [femoral varus osteotomy+Dega (Pemberton) osteotomy] (n=32). RESULTS: Using Stulberg classification I and II (acceptable outcome), the final outcome was statistically significant for group 2 (21 hips, 65.6%) compared with group 1 (18 hips, 38.3%) (P=0.031). The average remodeling efficacy, defined as the change in caput index between preoperation and postoperation, was better in group 2 (12.7%) than in group 1 (3.9%) (P=0.005). The acetabulum-head index and α-angle were also statistically significant in group 2 than in group 1 at the last follow-up. Clinical evaluations were statistically significant in group 2 compared with group 1. CONCLUSIONS: Both clinically and radiologically, the combined procedure group demonstrated significantly better outcomes with accelerated remodeling in both the severely affected femoral heads and the acetabula compared with the single procedure group. With this procedure, we anticipate the increased likelihood of preventing or delaying coxarthroses in adulthood. LEVEL OF EVIDENCE: Level III-therapeutic study.

Postoperative improvement of femoroacetabular impingement after intertrochanteric flexion osteotomy for SCFE.

BACKGROUND: Patients with slipped capital femoral epiphysis (SCFE) may develop cam-type femoroacetabular impingement (FAI). Early management of FAI has been advocated for patients with symptomatic FAI. The various treatment options, including reorientation surgeries, realignment procedures, and osteoplasty, remain controversial. QUESTIONS/PURPOSES: We asked whether an intertrochanteric flexion osteotomy improved the clinical symptoms of FAI in patients with SCFE and confirmed whether the radiographic signs were compatible with the clinical signs of FAI. METHODS: We retrospectively reviewed 32 symptomatic patients who underwent 32 intertrochanteric flexion osteotomies for severe SCFE. FAI was diagnosed clinically with a positive impingement sign. The osteotomies were designed preoperatively using CT. Cam-type FAI was evaluated with the modified α angle (ß angle) on a Lauenstein view, measured between the proximal femoral shaft axis and the line from the center of the femoral head to the anterior point where the distance of the head center exceeded the femoral head radius. The minimum followup was 2 years (mean, 5 years; range, 2-9 years). RESULTS: At last followup, only two patients complained of pain or inconvenience in daily life; the impingement sign was negative in 24 hips (75%). The ß angles at last followup were reduced on average by 39°. The postoperative ß angle was higher in hips with positive clinical signs of FAI than in those with negative signs. CONCLUSIONS: Intertrochanteric flexion osteotomy for SCFE improved the clinical and radiographic signs of FAI. The ß angle and clinical findings showed compatible improvement. We believe our intertrochanteric flexion osteotomy is a viable option for treating severe SCFE. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Natural history of popliteal cysts in the pediatric population.

BACKGROUND: Cystic mass lesions in the popliteal area, called popliteal cysts or Baker's cysts, are usually minimally symptomatic and not related to intra-articular morbidity in the pediatric population. Although multiple studies have described cases of spontaneous resolution over a period of several months to a few years, others still consider surgical treatment necessary. Furthermore, no previous studies have used magnetic resonance imaging (MRI) to confirm the disappearance of popliteal cysts. In this retrospective study, we reviewed records of patients with popliteal cysts to investigate the natural history of this disease. METHODS: The medical records of patients with popliteal cysts followed for at least 12 months were retrospectively reviewed. The patient set comprised of 17 knees in 15 males and 3 knees in 2 females. Mean age was 5.6±2.0 years (range, 1.8 to 11.4 y) at their initial visit to the clinic, and mean follow-up period was 53.1±31.6 months (range, 12.6 to 147.8 mo). MRI findings were reviewed for the 16 knees in 13 patients who had undergone MRI. Symptoms and clinical course were extracted from the medical records of all the study subjects and analyzed. RESULTS: Although 6 knees (30%) had histories of pain in the popliteal area, no patient complained of pain at their initial visit. Seventeen cysts (85%) naturally decreased in size or disappeared on clinical examination and/or ultrasound. Cysts confined to either the gastrocnemio-semimembranosus bursa or the subgastrocnemius bursa according to the MRI findings were classified as type I, and cysts which occupied both bursae were classified as type II. Eight knees received MRI examination more than once, and complete disappearance was confirmed in 5 of these knees. All type II cysts converted to type I, and all cysts which completely disappeared were type I before disappearance. CONCLUSIONS: The MRI findings in our study population confirmed that popliteal cysts in pediatric populations can be expected to completely resolve in due course without treatment. LEVEL OF EVIDENCE: Therapeutic study Level IV (Case series).

Remodeling of angulation deformities in diaphyseal femoral fracture in children.

BACKGROUND: The purpose of this study was to reconsider the factors influencing the remodeling effects in diaphyseal femoral fractures in children based on radiological results. PATIENTS AND METHOD: We reviewed 39 patients with more than a 5° residual angulation deformity at the fracture site on anteroposterior and/or lateral views at the primary healing stage. The average follow-up period was 30.4 months. Angulation deformity was measured on plain radiographs both at the primary healing stage and the final follow-up. The correction rate (A - B/A × 100, A angulation deformities at the primary healing, B the angulation at the final follow-up) between at the primary healing stage and final follow-up was analyzed in terms of age at injury (0-5, 6-9, and ≥10 years), fracture site (proximal one third, middle one third, and distal one third) and direction of the deformities (coronal and sagittal planes). RESULT: The remodeling effect significantly appeared on the coronal plane (correction rate 66.7 %) rather than on the sagittal plane (correction rate 31.6 %) in the 0- to 5-year age group (P < 0.05). There was a statistically significant difference in the correction rate between the 0- to 5-year age group (66.7 %) and the 6- to 9-year group (30.6 %) on the coronal plane (P < 0.05), with no significance between any other two groups on both planes. No statistical difference of remodeling effect appeared among the three fracture sites. The average leg-length discrepancy was 4.7 mm longer. CONCLUSION: We suggest that a patient ≤5 years at injury could expect more sufficient remodeling on the coronal plane compared with the other age groups on both planes. However, a patient >5 years at injury should be encouraged to undergo the maximum possible correction of the angulation deformity at the initial treatment. Surgical intervention might be considered for that purpose.

Drehmann sign and femoro-acetabular impingement in SCFE.

BACKGROUND: Drehmann sign is a characteristic clinical feature in slipped capital femoral epiphysis (SCFE). The presence of SCFE indicates an anatomic change of the proximal femur, which induces obligatory hip external rotation with hip flexion. In contrast, a cam-type femoro-acetabular impingement (FAI) is well known as sequelae of SCFE. The purpose of this study was to clarify the relationship between Drehmann sign and radiologic FAI. METHODS: We studied 92 hips of 80 SCFE patients who had been treated with in situ fixation. The occurrence rate of Drehmann sign was analyzed according to the degree of remodeling (the Jones classification) and the radiologic α-angle measured in each class at the final follow-up. At a mean 12.2 years after the final follow-up, the patients' present condition was clinically investigated with a questionnaire using a part of the Harris Hip Rating Scale (HHRS). In addition, 3-dimensional computed tomography analysis was performed to clarify the anatomic relationship between the femoral head and the acetabulum during testing for Drehmann sign. RESULTS: Among the 92 hips in the study, 60 were well remodeled (Jones type A), 24 were type B, and 8 were type C, with 6.5 years of mean follow-up. The mean of the modified α-angles for the 3 groups (A, B, and C) were 61.8, 84.7, and 119.4, respectively (P < 0.05); 25%, 75%, and 100% of the hips in the 3 groups, respectively, exhibited Drehmann sign. The set of hips (n = 41) with a positive Drehmann sign had a mean α-angle of 85.6 versus 63.0 degrees for the set of hips (n = 51) with a negative Drehmann sign (P < 0.05). Seven (13.5%) of 52 patients responding to the questionnaire reported hip pain and/or limp in the positive Drehmann sign group, but no patient in the negative sign group complained of either. Three-dimensional computed tomography delineated FAI at 2 different positions during testing for Drehmann sign. CONCLUSIONS: Drehmann sign is highly valuable for clinically evaluating the existence of FAI and for following up with observation or realignment to prevent early osteoarthritis.

[Articular cartilage regeneration with synovial mesenchymal stem cells].

Cell transplantation has shown to be a promising strategy to repair cartilage defects. Mesenchymal stem cells derived from synovium have been shown to be a superior cell source for cartilage regeneration to those from other mesenchymal tissues due to their higher rates of colony formation, proliferation potential with autologous serum, and in vitro/vivo chondrogenic potentials. We have found that approximately 60% of synovial mesenchymal stem cells placed on cartilage defects adhered to the defect within 10 min, and the addition of magnesium enhanced this percentage further, which resulted in better cartilage regeneration. Based upon several basic research studies performed in our lab, we have begun the transplantation of synovial stem cells arthroscopically in a clinical study for the treatment of cartilage defects. To date, no adverse events have been reported in the study. Regeneration of cartilage, reduction in defect size and an improvement of symptoms have been obtained in most patients over the last 3 years.

Childhood-onset systemic lupus erythematosus with trisomy X and the increased risk for bone complications: a case report.

BACKGROUND: Systemic lupus erythematosus is a multi-organ inflammatory autoimmune disease; immune complexes are part of the pathogenesis, but not entirely responsible. Trisomy X is the most common female chromosomal abnormality and the role of an additional X chromosome in the development of systemic lupus erythematosus is well recognized. However, the potential complications and optimal management of childhood lupus with trisomy X remain unclear. Herein, we describe a case of childhood-onset systemic lupus erythematosus associated with severe bone complications presumably secondary to trisomy X. CASE PRESENTATION: A 16-year-old Japanese girl was diagnosed with childhood-onset systemic lupus erythematosus and trisomy X. A chromosomal abnormality (47, XXX) was incidentally identified on bone marrow examination initially done to determine the cause of pancytopenia. She had a persistent headache, fever　for six days, diffuse hair loss, mucosal ulcers, butterfly eruptions, and palmar erythema. Furthermore, thrombocytopenia, anemia, and erythrocyte fragmentation were detected, suggesting secondary thrombotic microangiopathy. She was initially treated with intravenous methylprednisolone pulse therapy and prescribed monthly cyclophosphamide for severe disease activity, prednisolone, mycophenolate mofetil, and hydroxychloroquine as remission maintenance drugs. She developed generalized extremity pain that had been worsening throughout the disease. Extremity magnetic resonance imaging performed 12 months after the treatment onset revealed multifocal avascular necrosis, and dual-energy X-ray absorptiometry revealed further decreased bone mineral density. High plasma levels of factor VIII were detected by additional tests for coagulation functions, and we suspected the possibility that factor VIII might cause avascular necrosis due to thrombosis. Currently, she is being treated with prednisolone and MMF for SLE. However, her extremity pain has not been managed effectively even under the administration of non-steroidal anti-inflammatory drugs and pregabalin. CONCLUSIONS: An additional X chromosome has been reported to be associated with factor VIII and osteoporosis. Additionally, elevated plasma levels of FVIII is the risk factors for thrombosis, which leads to the risk of avascular necrosis. Patients with systemic lupus erythematosus complicated by trisomy X might be at a higher risk of avascular necrosis and osteoporosis that can also manifest in childhood systemic lupus erythematosus.

Morphological differences during in vitro chondrogenesis of bone marrow-, synovium-MSCs, and chondrocytes.

Mesenchymal stem cells (MSCs) from a variety of mesenchymal tissue contain common features, but distinguishing properties dependent on their origin are emerging. We investigated morphological differences of human bone marrow-MSCs, synovium-MSCs, and chondrocytes during in vitro chondrogenesis. Two hundred thousands cells were pelleted after centrifugation and cultured in chondrogenic media that contained BMP-2, TGF-beta3, and dexamethasone. The pellets were analyzed histologically, immunohistologically, and electron microscopically. Before chondrogenic induction, trypsinized MSCs and chondrocytes looked similar. At day 1, the structure of the three masses was divided into two layers, and the most obvious differences in the three populations were observed in the deep zone. In bone marrow-MSCs, round cells accumulated without intercellular space, and the cells were mainly connected through intermediate junctions. In synovium-MSCs, elongated cells accumulated with small desmosomes and intercellular spaces could occasionally be seen. In chondrocytes, separated oval and polygonal cells connected only in a narrow spotty area through a small desmosome. At day 7, the structure of the three masses was divided into three layers, and the most obvious differences in the three populations were observed in the middle zone. In bone marrow-MSCs, the middle zone consisted of dense smaller cells and apoptotic cells. In synovium-MSCs, the middle zone consisted of dense arrayed wider cells and apoptotic cells. In chondrocytes, the middle zone was acellular without apoptotic cells. At day 21, the morphology of cells and extracellular space became similar in that each cell was located separately with abundant extracellular matrix. The superficial zone was still obvious in bone marrow-MSCs, but hardly seen both in synovium-MSCs and chondrocytes. In this study, we revealed morphological differences of bone marrow-MSCs, synovium-MSCs, and chondrocytes during in vitro chondrogenesis. The most obvious differences in the three populations were observed at day 1 in the deep zone.

Anatomy of the Tarsal Canal and Sinus in Relation to the Subtalar Joint Capsule.

BACKGROUND: Anatomical knowledge of the tarsal canal and sinus is still unclear owing to the complexity of the ligamentous structures within them, particularly the relationship with the capsules of the subtalar joints. The aim of this study was to examine the anatomical relationship between the fibrous tissues of the tarsal canal and sinus and the articular capsules of the subtalar joint. METHODS: We conducted a descriptive anatomical study of 21 embalmed cadaveric ankles. For a macroscopic overview of the subtalar joint, we removed the talus in 18 ankles and separated the fibrous tissues from the surrounding connective tissues to analyze the layered relationship between the inferior extensor retinaculum (IER) and the subtalar joint capsule. Additionally, we histologically analyzed the tarsal canal and the medial and lateral sides of the tarsal sinus using Masson's trichrome staining in 3 ankles. RESULTS: The medial and intermediate roots of the IER and interosseous talocalcaneal ligament (ITCL) were located in the same layer and were connected to each other, between the capsules of the posterior talocalcaneal and talocalcaneonavicular joints. The intermediate root of the IER and the cervical ligament (CL) had adjacent attachments on the tarsal sinus, and synovial tissues originating from the joint capsules filled the remaining area in the tarsal canal and sinus. CONCLUSION: We determined that the tarsal canal and sinus tarsi contained 3 layered structures: the anterior capsule of the posterior talocalcaneal joint, including the anterior capsule ligament; the layer of ITCL and IER; and the posterior capsule of the talocalcaneonavicular joint, including the CL. CLINICAL RELEVANCE: The results of this study may help with the understanding of the pathomechanism of subtalar instability and sinus tarsi syndrome, resulting in better treatment.

Sensitive and rapid detection of Vero toxin-producing Escherichia coli using loop-mediated isothermal amplification.

A loop-mediated isothermal amplification (LAMP) assay was developed to detect Vero toxin (VT)-producing Escherichia coli rapidly (within 60 min). The 24 strains of VT-producing E. coli were successfully amplified, but 6 strains of non-VT-producing E. coli and 46 bacterial species other than E. coli were not. The sensitivity of the LAMP assay was found to be >0.7 c.f.u. per test using serogroups O157, O26 and O111 of VT-producing E. coli; this sensitivity is greater than that obtained by PCR assay. Furthermore, the LAMP assay was examined for its ability to detect VT-producing E. coli in food because of the difficulty of detection in food samples. The recovery of VT-producing E. coli by LAMP assay from beef and radish sprouts inoculated with the pathogen was high, similar to that obtained using culture methods with direct plating and/or plating after immunomagnetic separation. Although PCR assay was unable to recover VT-producing E. coli from half of the radish samples, LAMP assay was successful in most samples. In addition, VT-producing E. coli was successfully detected in cultures of the beef samples by LAMP assay, but not by the culture method. The LAMP products in naturally contaminated beef samples were analysed to confirm the specific amplification of the VT-encoding gene, and were found to show a specific ladder band pattern on agarose gel after electrophoresis. Additionally the sequences of the LAMP products coincided well with the expected sequences of the VT-encoding gene. These results indicate that the proposed LAMP assay is a rapid, specific and sensitive method of detecting the VT-producing E. coli.

Sanitation of seawater effluent from seaweed processing plants using a photo-catalytic TiO2 oxidation.

A fine porcelain open-cell photo-catalytic filter with titanium dioxide (TiO(2)) was evaluated for sterilization and sanitation of bio-polluted industrial water. In simulated seawater industrial effluent samples, the populations of Escherichia coli and Vibrio parahaemolyticus quickly decreased and reached non-detectable level within 10min. In seawater effluents from a seaweed processing plant, the bacterial populations in two samples quickly decreased by more than 10(3). In another two samples the decreases were slow and lowered by less than 10(2). Using fluorescence microscopy, it was indicated that the bacterial cells treated with photo-catalytic TiO(2) were damaged. In addition, the protein concentration in simulated seawater effluent slowly decreased using the photo-catalytic TiO(2) reaction; and reached similar concentrations as seawater near cultured seaweed beds. These results indicate that using a reactor with a TiO(2) photo-catalyst filter was effective for the sanitation of seawater effluents.

Mesenchymal stem cells derived from synovium, meniscus, anterior cruciate ligament, and articular chondrocytes share similar gene expression profiles.

Mesenchymal stem cells (MSCs) can be obtained from various tissues, and contain common features. However, an increasing number of reports have described variant properties dependent of cell sources. We examined (1) whether MSCs existed in several intraarticular tissues, (2) whether gene expression profiles in intraarticular tissue MSCs closely resembled each other, and (3) whether identified genes were specific to intraarticular tissue MSCs. Human synovium, meniscus, intraarticular ligament, muscle, adipose tissue, and bone marrow were harvested, and colony-forming cells were analyzed. All these cells showed multipotentiality and surface markers typical of MSCs. Gene profiles of intraarticular tissue MSCs and chondrocytes were closer to each other than those of extraarticular tissues MSCs. Among three characteristic genes specific for intraarticular tissue MSCs, we focused on proline arginine-rich end leucine-rich repeat protein (PRELP). Higher expression of PRELP was confirmed in chondrocytes and intraarticular tissue MSCs among three elderly and three young donors. Synovium MSCs stably expressed PRELP, contrarily, bone marrow MSCs increased PRELP expression during in vitro chondrogenesis. In conclusion, MSCs could be isolated from various intraarticular tissues including meniscus and ligament, gene expression profiles of intraarticular tissue MSCs closely resembled each other, and the higher expression of PRELP was characteristic of intraarticular tissue MSCs.

Functional development of Src tyrosine kinases during evolution from a unicellular ancestor to multicellular animals.

The Src family of tyrosine kinases play pivotal roles in regulating cellular functions characteristic of multicellular animals, including cell-cell interactions, cell-substrate adhesion, and cell migration. To investigate the functional alteration of Src kinases during evolution from a unicellular ancestor to multicellular animals, we characterized Src orthologs from the unicellular choanoflagellate Monosiga ovata and the primitive multicellular sponge Ephydatia fluviatilis. Here, we show that the src gene family and its C-terminal Src kinase (Csk)-mediated regulatory system already were established in the unicellular M. ovata and that unicellular Src has unique features relative to multicellular Src: It can be phosphorylated by Csk at the negative regulatory site but still exhibits substantial activity even in the phosphorylated form. Analyses of chimera molecules between M. ovata and E. fluviatilis Src orthologs reveal that structural alterations in the kinase domain are responsible for the unstable negative regulation of M. ovata Src. When expressed in vertebrate fibroblasts, M. ovata Src can induce cell transformation irrespective of the presence of Csk. These findings suggest that a structure of Src required for the stable Csk-mediated negative regulation still is immature in the unicellular M. ovata and that the development of stable negative regulation of Src may correlate with the evolution of multicellularity in animals.