Extracellular Calcium-Binding Peptide-Modified Ceramics Stimulate Regeneration of Calvarial Bone Defects

Secreted protein, acidic, cysteine-rich (SPARC)-related modular calcium binding 1 (SMOC1) has been implicated in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs). In this study, we found that a peptide (16 amino acids in length), which is located in the extracellular calcium (EC) binding domain of SMOC1, stimulated osteogenic differentiation of human BMSCs in vitro and calvarial bone regeneration in vivo. Treatment of BMSCs with SMOC1-EC peptide significantly stimulated their mineralization in a dose-dependent manner without changing their rate of proliferation. The expression of osteogenic differentiation marker genes, including type 1 collagen and osteocalcin, also increased in a dose-dependent manner. To examine the effect of the SMOC1-EC peptide on bone formation in vivo, the peptide was covalently immobilized onto hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) particles. X-ray photoelectron spectroscopy analysis showed that the peptide was successfully immobilized onto the surface of HA/β-TCP. Implantation of the SMOC1-EC peptide-immobilized HA/β-TCP particles into mouse calvarial defects and subsequent analyses using microcomputed tomography and histology showed significant bone regeneration compared with that of calvarial defects implanted with unmodified HA/β-TCP particles. Collectively, our data suggest that a peptide derived from the EC domain of SMOC1 induces osteogenic differentiation of human BMSCs in vitro and efficiently enhances bone regeneration in vivo.

Job Stress, Organizational Commitment, Way of Coping and Turnover Intention among Korean Visiting Nurses / 한국직업건강간호학회지

PURPOSE: The purpose of the study was to identify factors related to turnover intention among Korean visiting nurses. METHODS: The data from 192 of 208 nurses working in southern part of Korea were collected for analysis during in-service education in May 19~20, 2011. Descriptive statistics, chi-square tests, ANOVA, and logistic regression analysis were performed using SPSS 19.0 program. RESULTS: Among the general characteristic factors, young, married, university graduation, lower satisfaction with income and longer work experience as a nurse were associated with higher odds of turnover intention. Organizational commitment was associated with low turnover intention. Way of coping was not statistically significantly associated with turnover intension. CONCLUSION: Stress from the organizational system was found to be the most important variable that explains the turnover intention in this study. Use of sensible communication methods and introduction of effective conflict resolution system is suggested to reduce turnover intention. Further research is recommended to identify the job demands and organizational systems of visiting nurses.

Methyl-beta-cyclodextrin inhibits cell growth and cell cycle arrest via a prostaglandin E(2) independent pathway

Methyl-beta-cyclodextrin, a cyclic oligosaccharide known for its interaction with the plasma membrane induces several events in cells including cell growth and anti-tumor activity. In this study, we have investigated the possible role of cyclooxygenase 2 (COX-2) in cell growth arrest induced by methyl-beta-cyclodextrin in Raw264.7 macrophage cells. Methyl-beta-cyclodextrin inhibited cell growth and arrested the cell cycle, and this cell cycle arrest reduced the population of cells in the S phase, and concomitantly reduced cyclin A and D expressions. Methyl-beta-cyclodextrin in a dose- and time-dependent manner, also induced COX-2 expression, prostaglandin E(2) (PGE(2)) synthesis, and COX-2 promoter activity. Pretreatment of cells with NS398, a COX-2 specific inhibitor completely blocked PGE(2) synthesis induced by methyl-beta-cyclodextrin, however inhibition on cell proliferation and cell cycle arrest was not effected, suggesting non-association of COX-2 in the cell cycle arrest. These results suggest that methyl-beta-cyclodextrin induced cell growth inhibition and cell cycle arrest in Raw264.7 cells may be mediated by cyclin A and D1 expression.

Interleukin-1beta stimulates matrix metalloproteinase-2 expression via a prostaglandin E2-dependent mechanism in human chondrocytes

IL-1beta is known promote cyclooxygenase-2 (COX- 2) and matrix metalloproteinase-2 (MMP-2) expression. This study focuses on the characterization of the signaling cascade associated with IL-1beta-induced matrix metalloproteinase-2 (MMP- 2) regulation in human chondrocytes. The decrease in collagen levels in the conditioned media was prevented by a broad spectrum MMP inhibitor, suggesting that IL-1beta promotes the proteolytic process leading to MMP-2 activation. IL-1beta-related MMP-2 expression was found to be dependent on prostaglandin E2 (PGE2) production. In addition, the induction of COX-2 and MMP-2 was inhibited by the pretreatment of chondrocytes with a SB203580 or Ro 31-8220, indicating the involvement of protein kinase C (PKC) or p38 mitogen-activated protein kinase (MAPK). However, there is no cross-talk between PKC and p38 MAPK in the IL-1beta-induced MMP-2 activation. Taken together, these results demonstrated that IL-1beta induces MMP-2 expression through the PGE2-dependent mechanism in human chondrocytes.

Effects of Renal Transplantation on Echocardiographic Changes: Ejection Fraction and Left Ventricular Mass Index

BACKGROUND AND OBJECTIVES: Cardiovascular disease is a leading cause of death in patients on long-term dialysis and cardiac mortality decreases after renal transplantation. The aim of this study was to investigate the effects of successful renal transplantation on cardiac structure and function assessed by echocardiography. MATERIAL AND METHOD: Eighteen adult chronic renal failure patients who were taken renal transplantation in our hospital were included. They were submitted to two echocardiographic evaluations at preoperative time and postoperative time (mean: 23months). RESULTS: At the time of transplantation, 18 patients had undergone hemodialysis through a fistula (mean: 44months). At postoperative follow up, blood urea nitrogen/creatinine were decreased and mean hemoglobin level was increased. And systolic/diastolic blood pressure were decreased. Left ventricular mass index, left ventricular posterior wall thickness and septal wall thickness were decreased and ejection fraction was increased by echocardiography. Diastolic function did not improve. Hemodialysis duration and preoperative blood urea nitrogen/creatinine level affected ejection fraction change. CONCLUSION: We observed significantly decreased left ventricular mass index, increased ejection fraction after renal transplantation. We found that the patients who had been onlonger hemodialysis and higher preoperative blood urea nitrogen/creatinine level showed marked improvement of ejection fraction buy echocardiography.