Risk factors for delayed colorectal postpolypectomy bleeding: a meta-analysis.

BACKGROUND: To systematically analyze risk factors for delayed postpolypectomy bleeding (DPPB) in colorectum. METHODS: We searched seven large databases from inception to July 2022 to identify studies that investigated risk factors for DPPB. The effect sizes were expressed by relative risk (RR) and 95% confidence interval (95% CI). The heterogeneity was analyzed by calculating I2 values and performing sensitivity analyses. RESULTS: A total of 15 articles involving 24,074 subjects were included in the study. The incidence of DPPB was found to be 0.02% (95% CI, 0.01-0.03), with an I2 value of 98%. Our analysis revealed that male sex (RR = 1.64), history of hypertension (RR = 1.54), anticoagulation (RR = 4.04), polyp size (RR = 1.19), polyp size ≥ 10 mm (RR = 2.43), polyp size > 10 mm (RR = 3.83), polyps located in the right semicolon (RR = 2.48) and endoscopic mucosal resection (RR = 2.99) were risk factors for DPPB. CONCLUSIONS: Male sex, hypertension, anticoagulation, polyp size, polyp size ≥ 10 mm, polyps located in the right semicolon, and endoscopic mucosal resection were the risk factors for DPPB. Based on our findings, we recommend that endoscopists should fully consider and implement effective intervention measures to minimize the risk of DPPB.

Characteristics of cervical intervertebral disc signal intensity: an analysis of T2-weighted magnetic resonance imaging in 5843 asymptomatic Chinese subjects.

PURPOSE: The study aimed to observe cervical intervertebral discs (IVDs) in asymptomatic subjects and to explore the factors associated with cervical intervertebral disc degeneration (IVDD). METHODS: Cervical spine MRI of 5843 subjects was retrospectively analyzed. On the sagittal T2-weighted MR images, the mean signal intensities of the nucleus pulposus were obtained. Standard signal intensity (SSI) of intervertebral discs was defined as the ratio of mean disc signal intensity to mean CSF signal intensity. RESULTS: In subjects under 70 years old, the SSI of IVD was lowest at the C5/6 level. In those over 70, the SSI of IVD was similar among the disc levels from C2/3 to C7/T1. The disc SSI decreased significantly with age in both genders. In subjects under 70 years old, the SSI of the discs at each level was higher in females than in males. In those over 70 years old, no difference was found in disc SSI between two genders at most disc levels. Logistic regression analysis showed that kyphotic and straight cervical spine, obesity and older age were associated with higher risk of having lower disc SSI. CONCLUSION: To our knowledge, this is the largest cross-sectional study using MRI-based quantitative assessment to characterize cervical IVDD in asymptomatic subjects. Cervical IVDD was shown to progress with age and significantly correlated with gender, BMI and cervical alignment. Early intervention of related factors may help delay cervical IVDD and prevent future neck and shoulder pain.

Impact of meteorological factors on hospital admissions for spinal diseases in Shanghai during 2015-2019.

PURPOSE: To assess the correlation between meteorological factors and spinal disease admissions. METHODS: Data was obtained from the electronic medical records of a tertiary general hospital. Meteorological data was collected from China Meteorological Science Data Sharing Service. Distributed lag nonlinear models were used to evaluate the impact of meteorological variables on weekly spinal disease admissions. RESULTS: A total of 2739 spinal cases were documented. Compared with estimates at the 50th, the cumulative relative risk (RR) for extremely high temperatures at the 97.5th over lag week 18 to lag week 20 increased by 75.7%. When the weekly maximum temperature reached 38°C during lag week 20, the maximum RR was 1.96 (95% CI:1.095-3.506). Moreover, the effects of extremely high temperatures on spinal disease admissions were more obvious in females and the age group ≥65 years old compared with males and the age group<65 years old. CONCLUSIONS: Extremely high temperatures were significantly associated with higher risks of spinal disease admissions.

MiR-92b-3p promotes neurite growth and functional recovery via the PTEN/AKT pathway in acute spinal cord injury.

Emerging evidence indicates that microRNAs play an important role in neural remodeling, including neurite growth, after acute spinal cord injury (ASCI). This study aims to identify the mechanism by which miR-92b-3p regulates neurite growth in vivo and in vitro. Adult Sprague-Dawley rats were selected to establish the ASCI model, and the expressions of miR-92b-3p and phosphate and tensin homolog deleted on chromosome ten (PTEN) were quantified at different time points. The interaction between miR-92b-3p and PTEN was further detected in the PC12 cell line and dual-luciferase reporter assay. Neurite growth proteins (GAP43 and NF-200) were assessed by western blotting after miR-92b-3p mimics treatment. The PTEN/AKT pathway-related proteins and their roles in miR-92b-3p regulation were also identified using western blotting and immunofluorescence in vitro through LY294002, an AKT inhibitor. The effect of miR-92b-3p was further determined in vivo according to the Basso-Beattie-Bresnahan (BBB) Scale and GAP43 and NF-200 expressions. miR-92b-3p was downregulated after ASCI, while PTEN showed a simultaneous opposing trend. Overexpression of miR-92b-3p downregulated PTEN expression and promoted phosphorylation of AKT, as well as the expression of GAP43 and NF-200 in PC12 cells. Furthermore, the dual-luciferase reporter assay revealed that miR-92b-3p exerted its effect by targeting PTEN's 3'-untranslated regions and that this effect could be counteracted by AKT phosphorylation blocker LY294002 through western blotting and immunofluorescence. Moreover, miR-92b-3p could also improve the BBB scale as well as GAP43 and NF-200 expression levels in vivo. Collectively, these results indicate that miR-92b-3p promotes neurite growth and functional recovery through the PTEN/AKT pathway in ASCI.

Etiology for Degenerative Disc Disease.

Degenerative disc disease is a multifaceted progressive irreversible condition and an inevitable part of aging, which has been found to be a contributing factor for low back pain and might cause radiculopathy, myelopathy, spinal stenosis, degenerative spondylolisthesis, and herniations. Its etiology is complex and multifactorial. Although genetics influence more dominant, the occupational and mechanical influences still persist as a major risk factor. This review emphasizes up-to-date knowledge regarding etiology of disc degeneration with special consideration on occupational, lifestyle factors, and genetic polymorphisms.

The combined use of unilateral pedicle screw and contralateral facet joint screw fixation in transforaminal lumbar interbody fusion.

PURPOSE: This paper is to evaluate the efficacy and safety of transforaminal lumbar interbody fusion (TLIF) using unilateral pedicle screws along with contralateral translaminar facet joint screw (UPS+TFS) fixation in comparison with the method using bilateral pedicle screws fixation (BPS) in degenerative lumbar diseases. METHODS: Forty patients with single-level lumbar diseases were divided into two groups randomly. One group was treated by TLIF with BPS fixation while the other group was treated by the new technique with UPS+TFS fixation. The preoperative and postoperative ODI, JOA, VAPS scores, mean operation time, mean operation blood loss, fusion rate and complications were collected for comparison under two surgical methods. In terms of complications, only two cases of superficial infection in the BPS group and one case of urinary tract infection in the other group was found. RESULTS: The mean operation time and blood loss was significantly less in UPS+TFS group than in BPS group. The preoperation and postoperative ODI, JOA and VAPS at the intervals of 6 weeks, 3, 6 months and 1 year between the BPS and UPS+TFS group showed no significant disparities. Only one patient in UPS+TFS group was not fused with pseudoarthrosis formation. CONCLUSIONS: The clinical efficacy and safety of TLIF with UPS+TFS fixation were comparable to BPS fixation; however, the soft tissue injury and the corresponding operation cost were reduced with unilateral pedicle screw plus translaminar facet screw fixation.

Clinical outcomes and sagittal alignment of single-level unilateral instrumented transforaminal lumbar interbody fusion with a 4 to 5-year follow-up.

PURPOSE: A retrospective study was designed to evaluate clinical outcomes and sagittal alignment following single-level unilateral instrumented transforaminal lumbar interbody fusion (TLIF). METHODS: From November 2008 to December 2010, a total of 139 patients, who suffered from single-level lumbar degenerative disease, were included in this study. Forty-seven males and seventy-two females with a mean age of 57.3 years were enrolled. The average follow-up period was 51.7 months with a range of 41-66 months. The follow-up rate was 85.6 %. Thirty-one patients had diagnosis of discogenic low back pain, ten had recurrent disk herniation, thirty-four had spinal stenosis, and fourty-four had spondylolisthesis. Clinical outcomes were evaluated using the Oswestry disability index (ODI), visual analog scale (VAS) and Japanese Orthopedic Association. Operating time, blood loss, length of stay, and complications were also evaluated. The sagittal alignment and fusion status were assessed by X-ray and three-dimensional computed tomography. RESULTS: The average operating time was 92.1 ± 27.5 min, the average blood loss was 135.1 ± 113.5 ml, and the average length of stay was 12.0 ± 2.9 days. The overall complication rate was 13.4 %, and the fusion rate was 82.4 %. The postoperative clinical outcomes and sagittal alignment were significantly different from the preoperative values. The final lumbar lordosis angle and segment lordosis angle were associated with back pain VAS and ODI scores, respectively. CONCLUSION: Unilateral instrumented TLIF is a safe and effective treatment option for single-level lumbar degenerative disease, and is less invasive, yields good outcomes and has a low complication rate. In addition, the procedure has the potential to partly restore sagittal alignment.

A rare synovial sarcoma of the spine in the thoracic vertebral body.

INTRODUCTION: Synovial sarcomas of the spine are very rare, most rare of which was occurring in the thoracic vertebral body. The diagnosis of synovial sarcomas was very difficult. It depends on the radiological examination, immunohistochemical examination and gene examination. The best treatment to them was completely surgical resection with negative margins. Other treatments such as radiation therapy and chemotherapy were just adjuvant. The prognosis of synovial sarcomas was disappointing. CASE PRESENTATION: A 26-year-old male patient had low back pain. The radiological examination showed bony erosion of the T7 vertebral body and no soft tissue mass around the spine. He underwent T7 resection en bloc and internal fixation with two levels above T7 and two levels below T7. Then histopathological and gene examination revealed high malignant synovial sarcoma. So he was treated by chemotherapy and external beam radiation therapy after surgery. CONCLUSION: Primary vertebral body synovial sarcoma is very rare and difficult to diagnose and treat.

Comparing the process of creeping substitution between allograft bone and local bone grafting in lumbar interbody fusion.

PURPOSE: A self-control study was designed to compare the process of creeping substitution between allograft bone and local bone grafting in lumbar interbody fusion. METHODS: From December 2011 to July 2012, 81 patients (mean age: 56.4) were included in this study and randomly allocated to two groups. Leopard cages were using in unilateral instrumentation transforaminal lumbar interbody fusion. In group 1, the cages were filled with the local bone on the side of the instrumentation and allograft bone on the other side. In group 2, they were totally filled with the local bone chips. Then, the special CT-reconstructions were made at 6- and 12-month follow-up. On the sagittal section, the sections of CT-reconstructions were perpendicular to the lateral axis of the cage from the side of the cage to the other side. Similarly, they were parallel to the lateral axis of the cage on the coronal section and intervertebral space on the cross section. The mean area size of bone mass on both sides of the cage was calculated, respectively, using image analysis software (Osirix, version 3.3.2) on each section in two groups. RESULTS: In group 1, at 6- and 12-month follow-up, significant differences were observed in the mean area size of bone mass between allograft bone and local bone grafting on the coronal, cross, and sagittal section. In group 2, the mean area size of local bone on both sides of the cage had no significant differences at 6- and 12-month follow-up on each section. CONCLUSIONS: The results of our study showed a superiority of local bone grafting over allograft bone.

Machinability and Surface Properties of Cryogenic Poly(methyl methacrylate) Machined via Single-Point Diamond Turning.

Poly(methyl methacrylate) (PMMA), with a glass transition temperature (Tg) over 100 °C, shows good mechanical and optical properties and has broad applications after being machined with single-point diamond turning (SPDT) at room temperature. Because of the high Tg, current efforts mostly focus on optimizing machining parameters to improve workpiece precision without considering the modification of material properties. Cryogenic cooling has been proven to be an effective method in assisting ultra-precision machining for certain types of metals, alloys, and polymers, but has never been used for PMMA before. In this work, cryogenic cooling was attempted during the SPDT of PMMA workpieces to improve surface quality. The machinability and surface properties of cryogenically cooled PMMA were investigated based on the mechanical properties at corresponding temperatures. Nanoindentation tests show that, when temperature is changed from 25 °C to 0 °C, the hardness and Young's modulus are increased by 37% and 22%, respectively. At these two temperature points, optimal parameters including spindle speed, feed rate and cut depth were obtained using Taguchi methods to obtain workpieces with high surface quality. The surface quality was evaluated based on the total height of the profile (Pt) and the arithmetic mean deviation (Ra). The measurement results show that the values of Pt and Ra of the workpiece machined at 0 °C are 124 nm and 6 nm, respectively, while the corresponding values of that machined at 25 °C are 291 nm and 11 nm. The test data show that cryogenic machining is useful for improving the form accuracy and reducing the surface roughness of PMMA. Moreover, the relationship between temperature, material properties and machinability weas established with dynamic mechanical analysis (DMA) data and a theoretical model. This can explain the origin of the better surface quality of the cryogenic material. The basis of this is that temperature affects the viscoelasticity of the polymer and the corresponding mechanical properties due to relaxation. Then, the material property changes will affect surface profile formation during machining. The experimental results and theoretical analysis show that cryogenically cooled PMMA has good machinability and improved surface quality when using SPDT compared to that at ambient temperature.

The Development of Spinal Endoscopic Ultrasonic Imaging System with an Automated Tissue Recognition Algorithm.

STUDY DESIGN: Preclinical experimental study. OBJECTIVE: To develop an intraoperative ultrasound-assisted imaging device, which could be placed at the surgical site through an endoscopic working channel and which could help surgeon recognition of different tissue types during endoscopic spinal surgery (ESS). SUMMARY OF BACKGROUND DATA: ESS remains a challenging task for spinal surgeons. Great proficiency and experience are needed to perform procedures such as intervertebral discectomy and neural decompression within a narrow channel. The limited surgical view poses a risk of damaging important structures, such as nerve roots. METHODS: We constructed a spinal endoscopic ultrasound system, using a 4-mm custom ultrasound probe, which can be easily inserted through the ESS working channel, allowing up to 10 mm depth detection. This system was applied to ovine lumbar spine samples to obtain ultrasound images. Subsequently, we proposed a two-stage classification algorithm, based on a pretrained DenseNet architecture for automated tissue recognition. The recognition algorithm was evaluated using accuracy and consistency. RESULTS: The probe can be easily used in the ESS working channel and produce clear and characteristic ultrasound images. We collected 367 images for training and testing of the recognition algorithm, including images of the spinal cord, nucleus pulposus, adipose tissue, bone, annulus fibrosus and nerve roots. The algorithm achieved over 90% accuracy in recognizing all types of tissues with a Kappa value of 0.875. The recognition times were under 0.1 s using the current configuration. CONCLUSION: Our system was able to be used in existing ESS working channels and clearly identified at-risk spinal structures in vitro. The pretrained algorithms could identify six intraspinal tissue types accurately and quickly. The concept and innovative application of intraoperative ultrasound in ESS may shorten the learning curve of ESS and improve surgical efficiency and safety.

Quantitative assessment of the effect of ABCA1 gene polymorphism on the risk of Alzheimer's disease.

ATP-binding cassette transporter A1 (ABCA1) is a membrane-associated protein which has attracted considerable attention as a candidate gene for Alzheimer's disease (AD) based on its function as a key factor in lipid metabolism by mediating cellular cholesterol efflux, the rate-limiting step in the production of nascent high-density lipoprotein (HDL) particles. The relationship between ABCA1 common variations (R219 K rs2230806, I883 M rs4149313 and R1587 K rs2230808) and AD has been reported in various ethnic groups; however, these studies have yielded contradictory results. To investigate this inconsistency, we performed a meta-analysis of 13 studies involving a total of 12,248 subjects to evaluate the effect of ABCA1 on genetic susceptibility for AD. Overall, the summary OR of AD was 1.01 (95 % CI: 0.93-1.10; P = 0.77), 1.10 (95 % CI: 0.96-1.26; P = 0.16), and 1.08 (95 % CI: 0.96-1.23; P = 0.21) for R219 K, I883 M and R1587 K polymorphism, respectively. No significant results were observed in dominant and recessive when compared with wild genotype for these polymorphisms. In the stratified analyses by ethnicity and sample size, no evidence of any gene-disease association was obtained. In conclusion, the present meta-analysis does not support the notion that common SNPs on ABCA1 is a major genetic risk factor for AD.

Endoscopic transnasal odontoidectomy to treat basilar invagination with congenital osseous malformations.

PURPOSE: Transoral resection of the odontoid has been accepted as a standard procedure to decompress the cervicomedullary junction during the past several decades. The endoscopic transnasal odontoidectomy is emerging as a feasible surgical alternative to conventional microscopic transoral approach. In this article, we describe several operative nuances and pearls from our experience about this approach, which provided successful decompression. METHODS: From September 2009 to April 2010, three consecutive patients with basilar invagination, of which the etiology was congenital osseous malformations, underwent endoscopic transnasal odontoidectomy. All patients presented with myelopathy. The last two cases also received occipitocervical fixation and bone fusion during the same surgical episode to ensure stability. RESULTS: All the patients were extubated after recovery from anesthesia and allowed oral food intake the next day. Cerebrospinal fluid rhinorrhea was found in the second case and cured by continuous lumber drainage of cerebrospinal fluid. No infection was noted. The average follow-up time was more than 24 months. Remarkable neurological recovery was observed postoperative in all patients. CONCLUSION: The endoscopic transnasal odontoidectomy is a feasible approach for anterior decompression of pathology at the cervicomedullary junction. The advantages over the standard transoral odontoidectomy include elimination of risk of tongue swelling and teeth damaging, improvement of visualization, alleviation of prolonged intubation, reduction of need for enteral tube feeding and less risk of affecting phonation. The minimally invasive access and faster recovery associated with this technique make it a valid alternative for decompression of the ventral side of the cervicomedullary junction.

Changes of number of cells expressing proliferation and progenitor cell markers with age in rabbit intervertebral discs.

Basic knowledge about the normal regeneration process within the intervertebral disc (IVD) is important to the understanding of the underlying biology. The presence of progenitor and stem cells in IVD has been verified. However, changes of number of progenitor and stem cells with age are still unknown. In this study, changes of cell proliferation and progenitor cell markers with age in IVD cells from rabbits of two different ages were investigated using flow cytometry, immunohistochemistry, real-time polymerase chain reaction, and western blot analysis. Proliferating cell nuclear antigen (PCNA) was chosen as a marker for proliferation, and Notch1, Jagged1, C-KIT, CD166 were chosen as stem/progenitor cell markers. Cell cycle analysis showed that cell number in the G2/M phase of the young rabbits was significantly higher than that of mature rabbits. Immunohistochemical staining demonstrated the expression of PCNA, C-KIT, CD166, Notch1, and Jagged1 in both young and mature annulus fibrosus (AF). Protein expressions of these cell markers in the young rabbits were all significantly higher than those in the mature rabbits. The expression levels of PCNA, CD166, C-KIT, Jagged1 were significantly higher in the AF, and PCNA, C-KIT in the nucleus pulposus from young rabbits than those from the mature rabbits. These findings demonstrated that both proliferation and progenitor cells exist in rabbit IVDs and the number of cells expressing proliferation and progenitor cell markers decreases with age in the rabbit IVD cells. Methods that are designed to maintain the endogenous progenitor cells and stimulate their proliferation could be successful in preventing or inhibiting degenerative disc disease.

Predictive Classification System for Low Back Pain Based on Unsupervised Clustering.

STUDY DESIGN: Retrospective study. OBJECTIVE: Lumbar magnetic resonance imaging (MRI) findings are believed to be associated with low back pain (LBP). This study sought to develop a new predictive classification system for low back pain. METHOD: Normal subjects with repeated lumbar MRI scans were retrospectively enrolled. A new classification system, based on the radiological features on MRI, was developed using an unsupervised clustering method. RESULTS: One hundred and fifty-nine subjects were included. Three distinguishable clusters were identified with unsupervised clustering that were significantly correlated with LBP (P = .017). The incidence of LBP was highest in cluster 3 (57.14%), nearly twice the incidence in cluster 1 (30.11%). There were obvious differences in the sagittal parameters among the 3 clusters. Cluster 3 had the smallest intervertebral height. Based on follow-up findings, 27% of subjects changed clusters. More subjects changed from cluster 1 to clusters 2 or 3 (14.5%) than changed from cluster 2 or cluster 3 to cluster 1 (5%). Participation in sport was more frequent in subjects who changed from cluster 3 to cluster 1. CONCLUSION: Using an unsupervised clustering method, we developed a new classification system comprising 3 clusters, which were significantly correlated with LBP. The prediction of LBP is independent of age and better than that based on individual sagittal parameters derived from MRI. A change in cluster during follow-up may partially predict lumbar degeneration. This study provides a new system for the prediction of LBP that should be useful for its diagnosis and treatment.

Neuroserpin upregulates in the early period of sustained spinal cord compression.

BACKGROUND: Neuroserpin (NSP) is a neuroprotective factor in the situation of ischemia of a brain, such as stroke. However, it has never been reported in the spinal cord, which is part of the central nervous system (CNS). METHODS: The expression of NSP was detected using Western blotting and neuron apoptosis detected by TUNEL staining following spinal cord ischemia caused by sustained compression in rats. RESULTS: The results showed that NSP was upregulated in the injury area of spinal cord, accompanied with the activation of micorglia and tissue plasminogen activator (tPA), which suggested that NSP also plays a neuroprotective role in spinal cord compression since neuronal apoptosis appears when NSP returns to normal levels or even lower. CONCLUSIONS: NSP upregulates in early periods of sustained spinal cord compression.

In vitro and in vivo effects of hyperglycemia and diabetes mellitus on nucleus pulposus cell senescence.

Diabetes mellitus contributes to intervertebral disc degeneration. Nucleus pulposus cell senescence plays an important role in intervertebral disc degeneration. However, the effects of hyperglycemia on human nucleus pulposus cells and the underlying process remains poorly understood. In the current study, we evaluated the effects of high glucose levels on human nucleus pulposus cell senescence in vitro and the effects of hyperglycemia on rat nucleus pulposus aging in vivo. Human nucleus pulposus cells were cultured in high-glucose medium (200 mM glucose) for 48 h. Senescence-associated ß-galactosidase staining, western blot analysis, and enzyme-linked immunosorbent assays were performed to evaluate human nucleus pulposus cell senescence. Flow cytometry and enzyme-linked immunosorbent assays were used to evaluate reactive oxygen species and advanced glycation end-product levels. Transcriptome sequencing followed by bioinformatics analysis was used to understand the abnormal biological processes of nucleus pulposus cells cultured in high-glucose medium. Diabetes mellitus rat models were established and histopathological and immunohistochemical analysis was conducted to examine nucleus pulposus tissue senescence in vivo. Exposure to a high glucose concentration promoted human nucleus pulposus cell senescence and increased the senescence-related secretion phenotype in human nucleus pulposus cells in vitro and in rat nucleus pulposus tissue in vivo. Bioinformatics analysis showed that hub genes were involved in nucleus pulposus cell cycle activities and cell senescence. The results suggest that appropriate blood glucose control may be key to preventing intervertebral disc degeneration in diabetic patients.

Proteasome inhibitor bortezomib targeted tumor-endothelial cell interaction in T-cell leukemia/lymphoma.

Endothelial cells have special relevance in tumor progression. Here, we investigated the effect of the proteasome inhibitor bortezomib on tumor-endothelial cell interaction in T-cell leukemia/lymphoma. In vitro, T-leukemia/lymphoma cell lines and primary T-leukemia/lymphoma cells were cultured with endothelial cells, either together or separately in Millicell Hanging Cell Culture system, the latter permits mutual cell exchange. At clinically achievable concentrations, in addition to a direct cytotoxicity on T-leukemia/lymphoma cells, bortezomib inhibited tumor cell adhesion to endothelial cells and endothelial cell migration toward tumor cells. In vivo, a murine tumor xenograft model was achieved by subcutaneous injection of Jurkat cells. Bortezomib also triggered an inhibition on tumor-endothelial cell contact and subsequent tumor cell infiltration. Cell adhesion molecule intracellular cell adhesion molecule-1 expression was significantly downregulated both on the tumor cells and on the endothelial cells. Taken together, bortezomib could not only act on tumor cells themselves but also abrogate tumor cell interaction with endothelial cells. This delineates another therapeutic mechanism of bortezomib in T-cell malignancies.

Synthetic osteogenic growth peptide promotes differentiation of human bone marrow mesenchymal stem cells to osteoblasts via RhoA/ROCK pathway.

The osteogenic growth peptide (OGP) is a naturally occurring tetradecapeptide that has attracted considerable clinical interest as a bone anabolic agent and hematopoietic stimulator. In vitro studies have demonstrated that OGP directly regulates the bone marrow mesenchymal stem cells' (BMSCs) differentiation into osteoblasts. However, the exact mechanism of this process remains unknown. In the present study, we investigated the role of RhoA/ROCK signaling in differentiation along this lineage using human BMSCs. OGP treatment increased the mRNA level of bone morphogenetic protein-2 and alkaline phosphatase activity after osteogenic induction. Analysis of BMSCs induced in the presence of OGP revealed an increase in RhoA activity, and phosphorylation of FAK and cofilin. The ROCK-specific inhibitors, Y27632, blocked the OGP-induced regulation of BMSC differentiation. Taken together, these data suggest that OGP not only acts on BMSCs to stimulate osteogenic differentiation, but also in a dose-dependent manner, and this effect is mediated via the activation of RhoA/ROCK pathway.