Effect of modified compound calcium phosphate cement on the differentiation and osteogenesis of bone mesenchymal stem cells.

BACKGROUND: The aim of this study is to evaluate the effect of self-invented compound calcium phosphate cement upon the proliferation and osteogenesis of bone mesenchymal stem cells (BMSCs). METHODS: Four groups including traditional calcium phosphate cement, modified calcium phosphate cement, modified calcium phosphate cement plus bone morphogenetic protein (BMP), and control groups were established. The cell proliferation curve was delineated by MTT. The activity of BMSCs to synthesize alkaline phosphatase (AKP) was evaluated. The growth and invasion of BMSCs were observed. The expression levels of aggrecan, collagen I, collagen II, AKP, and OSX messenger RNA (mRNA) were measured by using RT-PCR. RESULTS: Compared with other groups, the BMSCs in the modified calcium phosphate cement group presented with loose microstructure and the BMSCs closely attached to the vector margin. At 7 days after co-culture, the expression of AKP in the modified calcium phosphate cement plus BMP group was significantly upregulated compared with those in other groups. In the modified calcium phosphate cement group, the BMSCs properly proliferated on the surface of bone cement and invaded into the cement space. At 10 days, the expression levels of aggrecan, collagen I, collagen II, AKP, and OSX mRNA in the modified calcium phosphate cement and modified calcium phosphate cement plus BMP groups were significantly upregulated than those in other groups. CONCLUSIONS: Modified compound calcium phosphate cement possesses excellent biocompatibility and osteogenic induction ability. Loose microstructure and large pore size create a favorable environment for BMSCs proliferation and vascular invasion, as an ideal vector for releasing BMP cytokines to mediate the differentiation and osteogenesis of BMSCs.

Cervical spinal functional magnetic resonance imaging of the spinal cord injured patient during electrical stimulation.

PURPOSE: To evaluate the spatial distribution and signal intensity changes following spinal cord activation in patients with spinal cord injury. METHODS: This study used spinal functional magnetic resonance imaging (fMRI) based on signal enhancement by extra-vascular water protons (SEEP) to assess elicited responses during subcutaneous electrical stimulation at the right elbow and right thumb in the cervical spinal cord. RESULTS: Seven healthy volunteers and seven patients with cervical spinal cord injury (SCI) were included in this study. Significant functional activation was observed mainly in the right side of the spinal cord at the level of the C5-C6 cervical vertebra in both the axial and sagittal planes. A higher percentage of signal changes (4.66 ± 2.08 % in injured subjects vs. 2.78 ± 1.66 % in normal) and more average activation voxels (4.69 ± 2.59 in injured subjects vs. 2.56 ± 1.13 in normal subject) in axial plane at the C5-C6 cervical vertebra with a statistically significant difference. The same trends were observed in the sagittal plane with higher percentage of signal changes and more average activation voxels, though no statistically significant difference compared with the control group. CONCLUSIONS: Spinal SEEP fMRI is a powerful noninvasive method for the study of local neuronal activation in the human spinal cord, which may be of clinical value for evaluating the effectiveness of interventions aimed at promoting recovery of function using electrical stimulation.

[Correlation study of spinal canal and dural sac dimensions on MRI with therapy of lumbar disc herniation].

OBJECTIVE: To explore the value of spinal canal and dural sac dimensions for the treatment of lumbar disc herniation in MRI. METHODS: The clinical data of 144 patients with single-level lumbar disc herniation underwent nonsurgical or surgical treatment from January 2010 to December 2012 were retrospectively analyzed. There were 91 patients in the nonsurgical group, including 55 males and 36 females, ranging in age from 20 to 68 years old with an average of (43.37±12.48) years; and there were 53 patients in the surgical group, including 28 males and 25 females, ranging in age from 20 to 64 years old with an average of (42.98±12.95) years. JOA scores (29 scores) were used to evaluate clinical manifestation (including subjective symptoms, objective findings, limitation of daily activities and bladder function) and outcomes. The parameters related to spinal canal and dural sac dimensions (including spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac cross-sectional area) in the initial axial T2-weighted MRI were measured, and odds ratio of available diameter to midsagittal diameter, odds ratio of lateral recess width to midsagittal diameter and area ratio of dural sac to spinal canal were calculated. Then, the differences of all parameters between two groups, and the correlations with initial JOA scores were analyzed. RESULTS: (1) All patients were followed up from 1 to 3 years with an average of 2.1 years. JOA scores before treatment were 16.27±2.96 in nonsurgical group and 12.64±3.30 in surgical group, there was statistically significant difference (t=6.319, P<0.01). At final follow-up time, there was no statistically significant difference in JOA scores (25.41±2.22 vs 25.76±2.29), improvement rate [(72.95±12.54)% vs (76.80±9.45)%], and the excellent and good rate (84.91% vs 78.02%) between two groups (P>0.05). But, the relapse rate of nonsurgical group was higher than surgical group (14.29% vs 5.67%). (2) Spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac area, the ratio of available diameter to midsagittal diameter, and the ratio of lateral recess width to midsagittal diameter in surgical group were smaller than that of nonsurgical group, but the area ratio of dural sac to spinal canal was larger, and there were statistically significant differences between two groups (P<0.01). (3) The initial JOA scores showed significantly positive correlation with spinal canal midsagittal diameter and available diameter, lateral recess width, and canal and dural sac area (P<0.01); also presented positive correlation with the ratio of available diameter to midsagittal diameter and the ratio of lateral recess width to midsagittal diameter (P<0.05); but there was a significantly negative correlation between initial JOA scores and the area ratio of dural sac to spinal canal. CONCLUSION: Both nonsurgical and surgical treatment of lumbar disc herniation can obtain good effect, but the recurrence rate of non-surgical treatment is higher. Preoperative MRI measurement parameters of spinal canal and dural sac dimensions has certain value for the treatment selection of lumbar disc herniation, but further refinement and validation is still required.

Cilostazol prevents the degradation of collagen type II in human chondrocytes.

The alteration of extracellular matrix (ECM) in cartilage during the pathological development of Osteoarthritis (OA) changes the biomechanical environment of chondrocytes, which further drives the progression of the disease in the presence of inflammation. Healthy cartilage matrix mainly contains collagen type II, which is degraded by matrix metalloproteinase13 (MMP13), an important molecules responsible for joint damage in OA. Cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4-dihydro-2-(1H)-quinolinone) is a medication approved by the US Food and Drug Administration and used in the alleviation of the symptom of intermittent claudication in individuals with peripheral vascular disease. In this study, we reported that cilostazol is able to suppress the degradation of type II collagen in human chondrocytes induced by IL-1ß. Mechanistically, cilostazol treatment leads to inhibiting the expression of IRF-1, thereby prevents the induction of MMP-13. Signal transducers and activator of transcription 1 (STAT1) has been reported to play an essential role in regulating the activation of IRF-1. Our results indicated that cilostazol suppresses the activation of STAT1 by mitigating the phosphorylation of STAT1 at Ser727 and tyrosine phosphorylation of STAT1 at position 701 (Tyr701).

Significance of spinal canal and dural sac dimensions in predicting treatment of lumbar disc herniation.

This retrospective study was performed to investigate the significance of quantitative MRI measurements of spinal canal and dural sac dimensions for treatment decisions and clinical outcome of lumbar disc herniation. 182 patients (111 nonsurgical patients and 71 surgical patients) were included, while 78 nonsurgical patients and 50 surgical patients were enrolled in the final follow-up. The initial JOA score in nonsurgical patients was significantly superior to surgical patients (t-test: p < 0.001), whereas the final JOA score and the rate of improvement were not significantly different between the two groups of patients (t-test: p > 0.05). 88.46% of nonsurgical patients and 90.00% of surgical patients had a good or excellent outcome (chi-square test: p > 0.05). However, if the 16 recurrent cases were included, the proportions dropped to 75.82% and 84.90% for nonsurgical and surgical patients, respectively. Compared with nonsurgical patients, quantitative parameters, such as midsagittal diameter and available diameter of spinal canal, lateral recess width and cross-sectional areas of spinal canal and dural sac, were significantly smaller in surgical patients (t-test: p < 0.001), and was reflected in the initial JOA score (128 cases; Spearman rank correlation coefficient: r 0.01 = 0.486, 0.499, 0.493, 0.507, 0.484; p < 0.001). The spinal canal and dural sac dimensions were important predictive factors for treatment selection of lumbar disc herniation.

Evaluation of thoracic pedicle morphometry in a Chinese population using 3D reformatted CT.

The aim of this study was to investigate the detailed three-dimensional morphology of the pedicles from T1 to T12 in 120 Chinese patients using a light-speed Vct CT (General Electric). After reformatting the original images, the following parameters were studied: outer pedicle width (OPW), outer pedicle height (OPH), pedicle chord length (PCL), pedicle cortical thickness (PCT) of the isthmus, and transverse pedicle angle (TPA). The mean outer pedicle width, outer pedicle height, and pedicle chord length were significantly smaller in females than in males at all levels (P < 0.01). The percentage of outer pedicle width ≤ 5.0 mm and ≤ 4.5 mm was high at mid-thoracic pedicles. No significant differences were found in transverse pedicle angle and pedicle cortical thickness in males and females. Pedicle cortical thickness was significantly thinner in patients over 50 years old compared with patients below 50 years old at most levels. The results showed that a screw of larger than 4.5 mm would be too large for mid-thoracic segments in Chinese population, especially for female patients. Considering the amount of variation between individuals and the complicated structure of the thoracic pedicles, the use of the transpedicular screw fixation must be individualized for each patient and based on detailed preoperative assessment. Reformatted CT assessment is essential before this procedure is performed.

A three-dimensional study of the atlantodental interval in a normal Chinese population using reformatted computed tomography.

The atlantodental interval has been usually used for the evaluation of atlantoaxial instability. However, the asymmetry of the lateral atlantodental interval is occasionally found in healthy individuals. Controversy therefore exists as to the clinical significance of this asymmetry in patients after trauma. The purpose of this study was to determine the normal range of atlantodental intervals in normal individuals using reformatted computed tomography. In this study, C1-C2 vertebrae were imaged in 230 adult patients by a Lightspeed Vct CT (General Electric, CT, USA) with a slice thickness of 0.625 mm. After reformatting the original images, the anterior atlantodental interval (AADI) and lateral atlantodental interval (LADI) were measured. The AADI was found to be 1.83 ± 0.46 mm (0.9-3.4 mm) in males and 1.63 ± 0.43 mm (0.5-3.2 mm) in females. The AADI was significantly greater in males than in females (p < 0.05). The 95% confidence interval for AADI was 1.75-1.90 mm in males and 1.54-1.72 mm in females. No statistically significant differences were found between males and females in the left and right LADI, and LADI asymmetry. The left LADI was found to be 3.38 ± 0.87 mm (1.7-6.0 mm), and the right LADI was 3.42 ± 0.84 mm (1.7-5.9 mm) in males, while the left LADI was 3.30 ± 0.73 mm (1.5-5.3 mm) and the right LADI was 3.37 ± 0.92 mm (1.7-5.9 mm) in females. The 95% confidence interval for left LADI was 3.23-3.52 and 2.94-3.25 mm, and for right LADI was 3.27-3.56 and 3.18-3.56 mm in males and females, respectively. The mean asymmetry of LADI was 0.76 ± 0.66 mm (0.0-3.5 mm) in males and 0.73 ± 0.70 mm (0.0-3.7 mm) in females. The 95% confidence interval for LADI asymmetry was 0.65-0.87 mm in males and 0.59-0.88 mm in females. Most of the population was found to have an asymmetry ranging between 0.1 and 2.0 mm. The current study shows that LADI asymmetry is common in patients without any cervical spine abnormalities. LADI asymmetry may be a normal anatomic variant and there is no evidence to confirm that LADI asymmetry is a sensitive or specific indicator of traumatic atlantoaxial instability. Radiologists and clinicians should be aware of this normal range of asymmetry when interpreting CT scans of the atlantoaxial region.

Thoracic pedicle morphometry in different body height population: a three-dimensional study using reformatted computed tomography.

STUDY DESIGN: A three-dimensional study of the thoracic pedicle (T1-T12) morphometry in Chinese patients with different body height, using reformatted computed tomography (CT). OBJECTIVE: To quantify the dimensions of the thoracic pedicles and to analyze the relationship between body height and thoracic pedicle parameters. SUMMARY OF BACKGROUND DATA: The thoracic pedicle morphometry has been studied extensively in different populations using various techniques. Previous studies have shown a significantly smaller size of the thoracic pedicles in women than in men and in Asians than in Caucasians. Some authors postulated that it is the body height that contributes to the variation in the pedicle size. To our knowledge, however, no study has specifically analyzed the relationship between body height and thoracic pedicle parameters in detail. METHODS: In this study, T1 to T12 vertebrae were imaged in 126 Chinese patients by a Lightspeed Vct CT (General Electric, Bridgeport, Connecticut, USA). After reformatting the original images, the following parameters were calculated: outer pedicle width, outer pedicle height and pedicle cortical thickness of the pedicle isthmus, pedicle length, and transverse pedicle angle. All measured data were statistically analyzed by the independent t test and Pearson correlation test using SPSS software (SPSS Inc, Chicago, IL). RESULTS: The thoracic pedicle parameters were significantly smaller in women than in men except for the transverse pedicle angles and the pedicle cortical thickness. The percentage of outer pedicle widths less than 4.5 mm was extremely high at T3 to T9 in females and T4 to T7 in males. There was a much higher percentage of pedicle width of 4.5 mm or lesser, 4.0 mm or lesser, and 3.5 mm or lesser when body height was less than 160 cm. Body height is probably one of the main factors that contribute to the variation in pedicle size since a significant positive correlation was observed between pedicle size and body height. CONCLUSION: Body height is probably one of the main factors that contribute to the variation in pedicle size among different ethnic and sex groups. Transpedicular procedures using a 4.5-mm screw may not be applicable to much of the Chinese population at the upper and middle thoracic segments, especially for patients less than 160 cm in height. A reformatted CT evaluation is routinely recommended not only for choosing the proper screw but also for determining the feasibility of a true transpedicular procedure.

Reformatted computed tomographic evaluation of the thoracic pedicle in a Chinese population for the surgical application of transpedicular screw placement.

PURPOSE: To study the transverse thoracic pedicle diameter of a Chinese population and to determine the feasibility and safety of transpedicular screw fixation. METHODS: The authors studied the transverse pedicle diameter of the T1-T12 of the thoracic spine in a Chinese population using reformatted computed tomography. The data were compared with Caucasians and other Asians. RESULTS: The mean outer pedicle widths of the thoracic spine from T1 to T12 were 8.43, 6.65, 5.20, 4.44, 4.50, 4.87, 5.04, 5.32, 5.66, 6.65, 8.08 and 8.27 mm in males and 7.91, 6.03, 4.55, 3.91, 4.05, 4.31, 4.39, 4.60, 5.13, 5.67, 7.21 and 7.50 mm in females, respectively. Female patients have smaller dimensions compared with male patients. A significant percentage of patients have an outer pedicle width of less than 4.5 mm from T3 to T8, which is not suitable for transpedicular screw fixation with a 3.5 mm screw. CONCLUSIONS: The results of this study suggest that transpedicular screw fixation may not be suitable for the mid-thoracic regions in most Chinese females and that modified pedicle screw techniques or modified type of fixation is required in these patients. CT evaluation is a must before this procedure is performed.

SSFSE sequence functional MRI of the human cervical spinal cord with complex finger tapping.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers during alternated rest and a complex finger tapping task, in order to detect image intensity changes arising from neuronal activity. METHODS: Functional MR imaging data using single-shot fast spin-echo sequence (SSFSE) with echo time 42.4 ms on a 1.5 T GE Clinical System were acquired in eight subjects performing a complex finger tapping task. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Intensity changes (5.5-7.6%) were correlated with the time course of stimulation and were consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. The activated regions localized to the ipsilateral side of the spinal cord in agreement with the neural anatomy. CONCLUSION: Functional MR imaging signals can be reliably detected with finger tapping activity in the human cervical spinal cord using a SSFSE sequence with 42.4 ms echo time. The anatomic location of neural activity correlates with the muscles used in the finger tapping task.

Functional MR imaging of the cervical spinal cord by use of 20Hz functional electrical stimulation to median nerve.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers by 20Hz functional electrical stimulation to median nerve, in order to detect signal changes arising concomitant to neuronal activity. METHODS: Functional MR imaging data were acquired in six subjects with single-shot fast spin-echo sequence (SSFSE) on a 1.5T GE Clinical System. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Activation correlated with the time course of stimulation was consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. Regions of the spinal cord associated with motor and pain response were observed by 20Hz functional electrical stimulation to the median nerve. CONCLUSION: The functional MR imaging signal can be detected in the human cervical spinal cord with functional electrical stimulation. Investigating the FES response in the spinal cord using the spinal fMRI will be helpful for the further discussion on the diagnosis and functional recovery to spinal cord diseases.

Characterization of vacuolar-ATPase and selective inhibition of vacuolar-H(+)-ATPase in osteoclasts.

V-ATPase plays important roles in controlling the extra- and intra-cellular pH in eukaryotic cell, which is most crucial for cellular processes. V-ATPases are composed of a peripheral V(1) domain responsible for ATP hydrolysis and integral V(0) domain responsible for proton translocation. Osteoclasts are multinucleated cells responsible for bone resorption and relate to many common lytic bone disorders such as osteoporosis, bone aseptic loosening, and tumor-induced bone loss. This review summarizes the structure and function of V-ATPase and its subunit, the role of V-ATPase subunits in osteoclast function, V-ATPase inhibitors for osteoclast function, and highlights the importance of V-ATPase as a potential prime target for anti-resorptive agents.

Osteoclast and its roles in calcium metabolism and bone development and remodeling.

Osteoclasts are multinucleated cells responsible for bone resorption and play important roles in normal skeletal development, in the maintenance of its integrity throughout life, and in calcium metabolism. During bone resorption, the cytoskeleton of osteoclasts undergoes extensive reorganization, with polarization and formation of ruffled borders to secrete acid and formation of sealing zone to prevent leakage. The differentiation and function of osteoclasts are in turn regulated by osteoblasts, stromal cells, and bone. They are also subjected to negative feedback regulation by extracellular and intracellular calcium concentrations.

Interleukin-1 beta induction of neuron apoptosis depends on p38 mitogen-activated protein kinase activity after spinal cord injury.

AIM: Interleukin-1 beta (IL-1beta) has been implicated as an extracellular signal in the initiation of apoptosis in neurons and oligodendrocytes after spinal cord injury (SCI). To further characterize the apoptotic cascade initiated by IL-1beta after SCI, we examined the expression of IL-1beta, p38 mitogen-activated protein kinase (p38 MAPK) and caspase-3 after SCI, and further investigated whether p38 MAPK was involved in neuron apoptosis induced by IL-1beta. METHODS: Adult rats were given contusion SCI at the T-10 vertebrae level with a weight-drop impactor (10 g weight dropped 25.0 mm). The expression levels of IL-1beta, p38 MAPK and caspase-3 after SCI were assessed with Western blots, immunohistochemistry staining, and real time reverse transcription polymerase chain reactions (RT-PCR). Neuron apoptosis was assessed with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) method. RESULTS: Increased levels of IL-1beta and p38 MAPK were observed soon after injury, with a peak in expression levels within 6 h of injury. By 24 h after injury, caspase-3 expression was markedly increased in the injured spinal cord. TUNEL-positive cells were first observed in the lesioned area 6 h after SCI. The largest number of TUNEL-positive cells was observed at 24 h post-SCI. Intrathecal injection of the IL-1 receptor antagonist IL-1Ra significantly reduced expression of p38 MAPK and caspase-3, and reduced the number of TUNEL-positive cells. Moreover, intrathecal injection of an inhibitor of p38 MAPK, SB203580, also significantly reduced the expression of caspase-3, and reduced the number of TUNEL-positive cells in the injured spinal cord. CONCLUSION: The p38MAPK signaling pathway plays an important role in IL-1beta mediated induction of neuron apoptosis following SCI in rats.

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.