EphB4 enhances the process of endochondral ossification and inhibits remodeling during bone fracture repair

Previous reports have identified a role for the tyrosine kinase receptor EphB4 and its ligand, ephrinB2, as potential mediators of both bone formation by osteoblasts and bone resorption by osteoclasts. In the present study, we examined the role of EphB4 during bone repair after traumatic injury. We performed femoral fractures with internal fixation in transgenic mice that overexpress EphB4 under the collagen type 1 promoter (Col1‐EphB4) and investigated the bone repair process up to 12 weeks postfracture. The data indicated that Col1‐EphB4 mice exhibited stiffer and stronger bones after fracture compared with wild‐type mice. The fractured bones of Col1‐EphB4 transgenic mice displayed significantly greater tissue and bone volume 2 weeks postfracture compared with that of wild‐type mice. These findings correlated with increased chondrogenesis and mineral formation within the callus site at 2 weeks postfracture, as demonstrated by increased safranin O and von Kossa staining, respectively. Interestingly, Col1‐EphB4 mice were found to possess significantly greater numbers of clonogenic mesenchymal stromal progenitor cells (CFU‐F), with an increased capacity to form mineralized nodules in vitro under osteogenic conditions, when compared with those of the wild‐type control mice. Furthermore, Col1‐EphB4 mice had significantly lower numbers of TRAP‐positive multinucleated osteoclasts within the callus site. Taken together, these observations suggest that EphB4 promotes endochondral ossification while inhibiting osteoclast development during callus formation and may represent a novel drug target for the repair of fractured bones. © 2013 American Society for Bone and Mineral Research.     

Burdens and Psychological Health of Family Caregivers of People with Schizophrenia in Two Chinese Metropolitan Cities: Hong Kong and Guangzhou

Family members charged with the care of those suffering from schizophrenia experience considerable stress due to their multiple responsibilities. Research regarding the burdens of caregiving is scant in Hong Kong and China. The present study quantified the association of the duties of caregivers with mental health symptoms in two Asian cities having distinct health care systems (i.e., Hong Kong and Guangzhou, China). Thirty nine caregivers in Hong Kong and 70 caregivers in Guangzhou were recruited from nongovernmental mental health organizations. They were assessed using the Chinese version of the Involvement Evaluation Questionnaire and the General Health Questionnaire. While the Guangzhou family caregivers had a significantly higher burden than the Hong Kong sample, there was no significant difference in the psychological health status of family caregivers in the two cities. Result of correlational analyses, however, revealed high associations between burden of care variables and the psychological health of the caregivers. Findings for the present study have implications regarding the physical and mental health needs of those caring for seriously disturbed relatives.     

Reliability of measurements performed on two dimensional and three dimensional computed tomography in glenoid assessment for instability

Purpose

The main purpose of this study is to establish which of two methods is more reliable in glenoid assessment for instability in pre-operative planning. Accordingly, we have studied the intra- and inter-observer reliability of glenoid parameters with the use of two-dimensional (2D) and three-dimensional (3D) reconstructed computed tomography (CT) images.

Methods

One hundred glenoids were measured with the use of 2D-CT and 3D-CT (in 3D orientation) by two independent observers (one experienced and one inexperienced). Measurements were repeated after one week for 30 randomly selected glenoids.

Results

The intra-class correlation coefficient (ICC) for inter-observer reliability was significantly greater for 3D-CT (0.811 to 0.915) than for 2D-CT (0.523 to 0.925). All intra-observer reliability values for 3D-CT were near perfect (0.835 to 0.997), while those for 2D-CT were less reliable (0.704 to 0.960). A dependent t-test showed that, for both observers, almost all glenoid parameters (except R and d) differed significantly (p?<?0.05) between 2D and 3D measurement methods.

Conclusions

Therefore, it can be concluded that 3D glenoid reconstructions are more reliable for glenoid bone loss assessment than 2D-CT. The results suggest that quantifying a glenoid defect with the use of 2D image only—even if performed by an experienced orthopaedic surgeon—is prone to errors. Differences in measurements between and within observers can be explained by plane setting and identifying glenoid rim in 2D-CT. Accordingly, we recommend that glenoid measurements should be performed in 3D orientation using 3D reconstruction obtained from CT images for pre-operative assessments, which are crucial for surgical planning.

     

The KEL24 and KEL14 alleles of the Kell blood group system

BACKGROUND: The Kell blood group system consists of at least 21 antigens, which may be classified into five sets of alleles and at least 10 independently expressed antigens. The molecular basis of four of the five sets of alleles has been described; point mutations in KEL leading to amino acid substitutions characterize the alleles. In this study, the point mutation associated with the remaining allele, KEL14/KEL24, was determined. STUDY DESIGN AND METHODS: The 19 exons of KEL were amplified from genomic DNA by a polymerase chain reaction (PCR) procedure. The PCR products were sequenced. DNA sequences from unrelated KEL:14,24 and KEL:-14,24 individuals were compared to the DNA sequence of the common KEL:14,-24 phenotype. RESULTS: DNA from the KEL:14,24 person yielded both G and C at nt 659, indicating an Arg and Pro polymorphism in amino acid residue 180 of Kell protein. DNA from the KEL:-14,24 person had a G659C mutation in exon 6, indicating an Arg180Pro substitution. The G659C change introduces an Hae III restriction enzyme site, which was used to confirm the base mutations by restriction fragment length polymorphism analysis of the PCR products. CONCLUSION: A G659C mutation, predicting an Arg180Pro change in Kell protein, is associated with the KEL14/KEL24 allele.     

Beginnings of village-farming communities in southeastern Turkey-1972

The mound known as Çayönü Tepesi (38° 16′ N; 39° 43′ E) in southeastern Turkey is one of the increasing number of early village sites which, since World War II, have been excavated archeologically in greater southwestern Asia. The evidence recovered in the autumn 1972 campaign of the Joint Istanbul-Chicago Prehistoric Project is briefly described, with particular attention to Çayönü's architectural remains, which are most remarkable, considering the site's date of about 7000 B.C. There was evidence of domesticated food plants from the beginning but animal domesticates were not present (save the dog) until later in the major prehistoric phase of occupation.