Molecular basis for curvature formation in SepF polymerization.

The self-assembly of proteins into curved structures plays an important role in many cellular processes. One good example of this phenomenon is observed in the septum-forming protein (SepF), which forms polymerized structures with uniform curvatures. SepF is essential for regulating the thickness of the septum during bacteria cell division. In Bacillus subtilis, SepF polymerization involves two distinct interfaces, the ß-ß and α-α interfaces, which define the assembly unit and contact interfaces, respectively. However, the mechanism of curvature formation in this step is not yet fully understood. In this study, we employed solid-state NMR (SSNMR) to compare the structures of cyclic wild-type SepF assemblies with linear assemblies resulting from a mutation of G137 on the ß-ß interface. Our results demonstrate that while the sequence differences arise from the internal assembly unit, the dramatic changes in the shape of the assemblies depend on the α-α interface between the units. We further provide atomic-level insights into how the angular variation of the α2 helix on the α-α interface affects the curvature of the assemblies, using a combination of SSNMR, cryo-electron microscopy, and simulation methods. Our findings shed light on the shape control of protein assemblies and emphasize the importance of interhelical contacts in retaining curvature.

Dynamic Metabolons Using Stimuli-Responsive Protein Cages.

Naturally evolved metabolons have the ability to assemble and disassemble in response to environmental stimuli, allowing for the rapid reorganization of chemical reactions in living cells to meet changing cellular needs. However, replicating such capability in synthetic metabolons remains a challenge due to our limited understanding of the mechanisms by which the assembly and disassembly of such naturally occurring multienzyme complexes are controlled. Here, we report the synthesis of chemical- and light-responsive protein cages for assembling synthetic metabolons, enabling the dynamic regulation of enzymatic reactions in living cells. Particularly, a chemically responsive domain was fused to a self-assembled protein cage subunit, generating engineered protein cages capable of displaying proteins containing cognate interaction domains on their surfaces in response to small molecular cues. Chemical-induced colocalization of sequential enzymes on protein cages enhances the specificity of the branched deoxyviolacein biosynthetic reactions by 2.6-fold. Further, by replacing the chemical-inducible domain with a light-inducible dimerization domain, we created an optogenetic protein cage capable of reversibly recruiting and releasing targeted proteins onto and from the exterior of the protein cages in tens of seconds by on-off of blue light. Tethering the optogenetic protein cages to membranes enables the formation of light-switchable, membrane-bound metabolons, which can repeatably recruit-release enzymes, leading to the manipulation of substrate utilization across membranes on demand. Our work demonstrates a powerful and versatile strategy for constructing dynamic metabolons in engineered living cells for efficient and controllable biocatalysis.

ANLN and UBE2T are prognostic biomarkers associated with immune regulation in breast cancer: a bioinformatics analysis.

OBJECTIVES: To screen and verify differential genes affecting the prognosis of breast cancer. METHODS: Breast cancer gene expression datasets were downloaded from the GEO database, and original data were analyzed in R. The TIMER database was used to analyze the relationship between ANLN and UBE2T and immune cell infiltration. RESULTS: Ten hub-key genes were identified, and survival analysis showed that UBE2T and ANLN were upregulated in breast cancer and their upregulation was associated with a poor prognosis. ANLN and UBE2T upregulation was associated with the prevalence of Th1 and Th2 cells, shifting the Th1/Th2 balance to Th2 in Basal and Luminal-B breast cancers, which indicates a poor prognosis (P < 0.05). CONCLUSION: ANLN and UBE2T are potential biomarkers for predicting the prognosis of breast cancer.

Forecasting sensitive targets of the kynurenine pathway in pancreatic adenocarcinoma using mathematical modeling.

In this study, a new mathematical model was established and validated to forecast and define sensitive targets in the kynurenine pathway (Kynp) in pancreatic adenocarcinoma (PDAC). Using the Panc-1 cell line, genetic profiles of Kynp molecules were tested. qPCR data were implemented in the algorithm programming (fmincon and lsqnonlin function) to estimate 35 parameters of Kynp variables by Matlab 2017b. All tested parameters were defined as non-negative and bounded. Then, based on experimental data, the function of the fmincon equation was employed to estimate the approximate range of each parameter. These calculations were confirmed by qPCR and Western blot. The correlation coefficient (R) between model simulation and experimental data (72 hours, in intervals of 6 hours) of every variable was >0.988. The analysis of reliability and predictive accuracy depending on qPCR and Western blot data showed high predictive accuracy of the model; R was >0.988. Using the model calculations, kynurenine (x3, a6), GPR35 (x4, a8), NF-kßp105 (x7, a16), and NF-kßp65 (x8, a18) were recognized as sensitive targets in the Kynp. These predicted targets were confirmed by testing gene and protein expression responses. Therefore, this study provides new interdisciplinary evidence for Kynp-sensitive targets in the treatment of PDAC.

Potential efficacy of dendritic cell immunomodulation in the treatment of osteoarthritis.

Dendritic cells (DCs) are a cluster of heterogeneous antigen-presenting cells that play a pivotal role in both innate and adaptive immune responses. Rare reports have discussed their role in OA immunopathogenesis. Recently, DCs derived from the synovial fluid of OA mice were shown to have increased expression of toll-like receptors. Moreover, from in vitro studies it was concluded that DCs derived from OA patients had secreted high levels of inflammatory cytokines. Likewise, a significant increase in CD123+BDCA-2 plasmacytoid DCs has been observed in the synovial fluid of OA patients. Furthermore, DCs have a peripheral tolerance potential and can become regulatory under specific circumstances. This could be exploited as a promising tool to eliminate immunoinflammatory manifestations in OA disease. In this review, the potential roles DCs could play in OA pathogenesis have been described. In addition, suggestions for the development of new immunotherapeutic strategies involving intra-articular injections of tolerogenic plasmacytoid DCs for treating OA inflammations have been made.

Association between hip and knee osteoarthritis with falls: A systematic review and meta-analysis.

OBJECTIVE: To examine the association between hip and knee osteoarthritis (OA) and falls. Potentially relevant articles that examine the association between hip, knee, radiological, and self-reported OA and falls were retrieved from PubMed, EMBASE, Scopus, and Web of Science up until March of 2020. METHODS: The pooled risk ratios (RRs) as well as their related 95% confidence intervals (CIs) were calculated. Statistic and subgroup analyses were performed. A total of 21 studies involving 146 965 participants were included. RESULTS: No association was found between hip OA and falls. The pooled RRs value suggested a higher prevalence of falls in knee OA patients (RR = 1.35, 95% CI: 1.20 to 1.51, P < .00001) and self-reported OA (RR = 1.33, 95% CI: 1.23 to 1.45, P < .00001) than in non-OA subjects. The pooled RR value suggested no difference between prevalence of falls in radiological OA patients compared to non-OA subjects (RR = 1.82, 95% CI: 0.89 to 3.73, P = .10). Both radiological and self-reported knee OA seem to be positively associated with falls, while no obvious association was found between hip OA and falls. CONCLUSIONS: Therefore, knee OA is a risk factor for falls which should be closely monitored.

Interleukin 1 beta-induced chloride currents are important in osteoarthritis onset: an in vitro study.

Persistent hypotonic and inflammatory conditions in the joint cavity can lead to the loss of cartilage matrix and cell death, which are the important mechanisms of osteoarthritis (OA) onset. Previous studies have confirmed that the existence of a hypotonic environment is a red flag for inflammation, as hypotonic environment induces the opening of the chloride channel of the cell and promotes chloride ion efflux, which prompts the cell volume to increase. Chloride channels play an important role in the regulation of mineralization and chondrocyte death. Here, we reported that OA chondrocytes showed a significant increase of cell death rate and the imbalance of cartilage matrix catabolism. We found that the distribution of skeleton protein F-actin was disordered. In addition, the volume-sensitive chloride current of OA chondrocytes decreased significantly with the increase of the expression levels of inflammation-related proteins caspase-1, caspase-3, and NLRP3. Moreover, interleukin-1ß (IL-1ß) showed a potential to activate the chloride current of normal chondrocytes. These results indicate that IL-1ß-induced chloride channel opening in chondrocytes may be closely related to the occurrence of OA. This chloride channel opening process may therefore be a potential target for the treatment of OA.

Arthroscopic repair of the medium-size rotator cuff tear with the novel technique of the point union bridge: a minimum 2-year follow-up cohort study.

BACKGROUND: Achieving secure fixation and preventing retear have been recognized as fundamental in arthroscopic repair of rotator cuff tears. Moreover, reducing internal implantation can lower medical expenses and minimize the operation time, which is essential for the surgical safety and postoperative rehabilitation of the patients. We have recently proposed the point union bridge (PUB) suture configuration as a novel method for not only providing equivalent fixation but also decreasing the operation time and medical expenses. However, no comparative clinical studies have been performed. METHODS: From March 2014 to September 2016, a total of 88 patients with diagnoses of medium-size rotator cuff tears underwent arthroscopic repair with a randomly assigned technique-either the PUB technique (n = 42) or the double-row suture bridge (DRSB) technique (n = 46). All patients underwent a minimal 2-year follow-up. We used the Constant-Murley score (CMS), American Shoulder and Elbow Surgeons (ASES) score, active and passive range of motion, and visual pain-simulation score (visual analog scale [VAS] score) to assess the functional outcomes. In addition, we recorded the arthroscopic operation time, medical costs, and postoperative complications. All patients received magnetic resonance imaging at the 6-month and 2-year postoperative evaluations to assess structural integrity and tendon healing. RESULTS: At the 2-year follow-up, all scoring parameters evaluated (CMS, ASES score, and VAS score), as well as active and passive range of motion, improved significantly in both groups as compared with preoperative assessments. The PUB technique significantly decreased the operation time (55.9 ± 14.1 minutes vs. 72.2 ± 14.2 minutes for PUB vs. DRSB, P < .001) and medical expenses ($2608.0 ± $391.1 vs. $4056.9 ± $350.9 for PUB vs. DRSB, P < .001). However, no significant differences between the 2 techniques were found in any functional assessments of the shoulder (CMS, ASES score, and VAS score), repair integrity, or the retear rate at the 2-year follow-up. CONCLUSION: Arthroscopic repair of the medium-size rotator cuff tear with either the PUB or DRSB technique could yield both satisfactory improvements in the shoulder function of patients and equivalent tendon integrity. With less consumption of internal implants, the PUB technique significantly reduced the operation time and decreased medical expenses.

Intra-articular injection of hUC-MSCs expressing miR-140-5p induces cartilage self-repairing in the rat osteoarthritis.

INTRODUCTION: Currently, osteoarthritis (OA) receives global increasing attention because it associates severe joint pain and serious disability. Stem cells intra-articular injection therapy showed a potential therapeutic superiority to reduce OA development and to improve treating outputs. However, the long-term effect of stem cells intra-articular injection on the cartilage regeneration remains unclear. Recently, miR-140-5p was confirmed as a critical positive regulator in chondrogenesis. We hypothesized that hUC-MSCs overexpressing miR-140-5p have better therapeutic effect on osteoarthritis. MATERIALS AND METHODS: To enhance stem cell chondrogenic differentiation, we have transfected human umbilical cord mesenchymal stem cells (hUC-MSCs) with miR-140-5p mimics and miR-140-5p lentivirus to overexpress miR-140-5p in a short term or a long term accordingly. Thereafter, MSCs proliferation, chondrogenic genes expression and extracellular matrix were assessed. Destabilization of the medial meniscus (DMM) surgery was performed on the knee joints of SD rats as an OA model, and then intra-articular injection of hUC-MSCs or hUC-MSCs transfected with miR-140-5p lentivirus was carried to evaluate the cartilage healing effect with histological staining and OARSI scores. The localization of hUC-MSCs after intra-articular injection was further confirmed by immunohistochemical staining. RESULTS: Significant induction of chondrogenic differentiation in the miR-140-5p-hUC-MSCs (140-MSCs), while its proliferation was not influenced. Interestingly, intra-articular injection of 140-MSCs significantly enhanced articular cartilage self-repairing in comparison to normal hUC-MSCs. Moreover, we noticed that intra-articular injection of high 140-MSCs numbers reinforces cells assembling on the impaired cartilage surface and subsequently differentiated into chondrocytes. CONCLUSIONS: In conclusion, these results indicate therapeutic superiority of hUC-MSCs overexpressing miR-140-5p to treat OA using intra-articular injection.

Microarray profiling and functional analysis of differentially expressed plasma exosomal circular RNAs in Graves' disease.

BACKGROUND: Circulating RNA (circRNA) regulates various bioactivities in cells. A better understanding of the exosomal circRNA can provide novel insights into the pathogenesis and treatment of Graves' disease (GD). We aimed to profile the differentially expressed circRNAs (DEcRs) in plasma exosomes of patients with GD and speculate and probe the functions of the DEcR by comprehensive bioinformatics analyses. METHODS: Serum exosomes were isolated from five primary GD patients and five healthy controls via ultracentrifugation. After verification with transmission electron microscopy, exosome samples were subjected to microarray profiling using human circRNA microarrays. Two up-regulated and two down-regulated DEcRs were selected for validation in plasma exosomes from 20 GD and 20 healthy control participants using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). The circRNA/microRNA/mRNA interaction network was then assembled and the analysis of the Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways was utilized to predict the potential functions of the DEcR associated genes. RESULTS: There were 15 DEcRs revealed in primary GD cases. The intronic circRNA hsa_circRNA_000102 was confirmed as an up-regulated component in plasma exosomes from patients with GD. The circRNA/microRNA/mRNA interaction network unveiled the most potential targeting microRNAs of hsa_circRNA_000102 and its associated genes. The functional analyses predicted involvement of hsa_circRNA_000102 associated genes in pathways of immune system activation, such as viral infection and interferon-beta signaling. CONCLUSIONS: hsa_circRNA_000102 is a differentially up-regulated plasma exosomal circRNA in patients with GD. Our study highlights multiple pathways, particularly virus infection and interferon-beta signaling, for mediating immune activation in Graves' disease.

Functional Reconstruction of Hindfoot With Total Calcaneus and Talus Loss by Ilizarov Technique: A Case Report.

Total calcaneus and talus loss in the hindfoot is an unusual but severe condition encountered in clinical settings. This condition affects lower-extremity function and poses a significant challenge to limb salvage. We present a case of a 43-year-old man with total calcaneus and talus loss in the right foot treated by Ilizarov technique. A staged treatment protocol was planned to reconstruct and optimize the heel for weightbearing and walking. During the 15-month postoperative follow-up, the patient reported no significant discomfort in the targeted foot and regained satisfactory function, including shoe wearing, walking, driving, and climbing stairs. The American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale score was 71, which was an improvement from a preoperative score of 40. This case is the first reported on the functional reconstruction by Ilizarov technique of hindfoot with total calcaneus and talus loss. This treatment protocol provides an effective approach to reconstructing the hindfoot with massive bone loss, although the long-term outcome remains unknown.

ClC-3 chloride channels are involved in estradiol regulation of bone formation by MC3T3-E1 osteoblasts.

Evidence has been reported by us and others supporting the important roles of chloride channels in a number of osteoblast cell functions. The ClC-3 chloride channel is activated by estradiol binding to estrogen receptor alpha on the cell membranes of osteoblasts. However, the functions of these chloride channels in estrogen regulation of osteoblast metabolism remain unclear. In the present study, the roles of chloride channels in estrogen regulation of osteoblasts were investigated in the osteoblastic cell line MC3T3-E1. Estrogen 17ß-estradiol enhanced collagen I protein expression, alkaline phosphatase activity, and mineralization were inhibited, by chloride channel blockers. Estradiol promoted ClC-3 chloride channel protein expression. Silencing of ClC-3 chloride channel expression prevented the elevation of osteodifferentiation in osteoblasts, which were regulated by estrogen. These data suggest that estrogen can regulate bone formation by activating ClC-3 chloride channels and the activation of ClC-3 chloride channels can enhance the osteodifferentiation in osteoblasts.

Estrogen Modulates Cartilage and Subchondral Bone Remodeling in an Ovariectomized Rat Model of Postmenopausal Osteoarthritis.

BACKGROUND Estrogen levels regulate changes in osteoarthritis (OA) by inhibiting degradation of the extracellular matrix. Recent in vitro studies have also shown the role of microRNA-140-5p (miR-140-5p). This study aimed to investigate the role of estrogen deficiency, selective modulation of expression of the estrogen receptor (ER), and expression of miR-140-5p in cartilage and subchondral bone remodeling in an ovariectomized rat model of postmenopausal OA. MATERIAL AND METHODS Female Sprague-Dawley rats included two model groups, ovariectomized (OVX) rats and rats with destabilization of the medial meniscus (DMM) rats. Two months after surgery, estrogen levels were measured by the enzyme-linked immunosorbent assay (ELISA). Three-dimensional (3D) micro-computed tomography (micro-CT) was used to image the knee joints. Rats were treated with subcutaneous injection of estrogen (E2) or the selective estrogen receptor modulator (SERM), raloxifene (RAL), for one month. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-140-5p in serum, and histology of the knee joint cartilage and bone was performed. RESULTS In the ovariectomized rat model of OA, estrogen therapy reduced the degree of cartilaginous degeneration, while treatment with raloxifene showed no significant effect. Expression levels of miR-140-5p in the OA model group were significantly lower than the control group. Micro-CT showed that in the model group, anterior cruciate ligament dislocation and subchondral bone density were significantly reduced. CONCLUSIONS In an ovariectomized rat model of postmenopausal OA, estrogen deficiency resulted in resorption of subchondral bone and degeneration of articular cartilage.

Overexpression of ClC-3 Chloride Channel in Chondrosarcoma: An In Vivo Immunohistochemical Study with Tissue Microarray.

BACKGROUND Recently, ClC-3 chloride channel expression has been noted to be high in some tumors. In chondrosarcoma, which is a malignant tumor with a high incidence in the bone, there has been no previous literature regarding ClC-3 chloride channel expression. Here we evaluated the expression of ClC-3 chloride channel in chondrosarcoma and explored its clinical significance. MATERIAL AND METHODS In this study, 75 chondrosarcoma and 5 normal cartilage tissues were collected. Thereafter, tissue microarray was performed. Immunohistochemistry was also used to observe the level of ClC-3 chloride channel expression between normal and chondrosarcoma tissues. RESULTS Results showed that the expression of ClC-3 chloride channel in the normal chondrocyte was thinner, since it showed distinct differentiation among chondrosarcoma specimens. Interestingly, we noticed that the moderately-differentiated chondrosarcoma (MDC) and the poorly-differentiated chondrosarcoma (PDC) exhibited 94.44% of ClC-3 chloride channel. Besides, the subcellular localization of ClC-3 chloride channel was changed in association with malignant degree changes. The subcellular localization of ClC-3 chloride channel in the MDC and PDC tissue was localized in the cytoplasm and both nucleus and cytoplasm: 83.33% (5 out of 6 cases) and 91.66% (11 out of 12 cases) respectively. On the other hand, we noticed that patient age and gender could have a relation with ClC-3 chloride channel expression; 30- to 60-year-old males showed more expression. CONCLUSIONS These results demonstrated a high frequency of ClC-3 chloride channel overexpression and subcellular localization differences in MDC and PDC tissue, suggesting a specific role of ClC-3 chloride channel in the pathogenesis of chondrosarcoma.

Characterization of a novel polyvinyl alcohol/chitosan porous hydrogel combined with bone marrow mesenchymal stem cells and its application in articular cartilage repair.

BACKGROUND: Different substances are combined to compensate for each other's drawbacks and create an appropriate biomaterial. A novel Polyvinyl alcohol (PVA)/chitosan (CS) porous hydrogel was designed and applied to the treatment of osteochondral defects. METHODS: Hydrogels of various PVA/CS ratios were tested for physiochemical and mechanical properties in addition to cytotoxicity and biocompatibility. The hydrogels with the best PVA/CS ratio were used in the animal study. Osteochondral defects were created at the articular cartilage of 18 rabbits. They were assigned to different groups randomly (n = 6 per group): the osteochondral defect only group (control group), the osteochondral defect treated with hydrogel group (HG group), and the osteochondral defect treated with hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) group (HG-BMSCs group). The cartilage was collected for macro-observation and histological evaluation at 12 weeks after surgery. RESULTS: The Hydrogel with PVA/CS ratio of 6:4 exhibited the best mechanical properties; it also showed stable physical and chemical properties with porosity and over 90% water content. Furthermore, it demonstrated no cytotoxicity and was able to promote cell proliferation. The HG-BMSCs group achieved the best cartilage healing. CONCLUSIONS: The novel PVA/CS porous composite hydrogel could be a good candidate for a tissue engineering material in cartilage repair.

Clinical outcomes and radiologic assessment of a modified suture button arthroscopic Latarjet procedure.

BACKGROUND: As several neurologic and hardware complications have been reported with screw fixation. Suture buttons are used to serve as an alternative to screw fixation to obtain better outcome and to reduce the complication. The purpose of this study was to observe the clinical outcomes and make the radiologic assessment of a modified suture button (MSB) arthroscopic Latarjet procedure. METHODS: A total of ninty-one patients with recurrent shoulder joint dislocation who underwent MSB arthroscopic Latarjet procedure was retrospectively reviewed. Fifty cases identified from the chart review met the inclusion criteria. The clinical outcomes and position of the grafts, glenohumeral degeneration, and graft healing condition were assessed postoperatively in a follow-up with at least one and half of a year. RESULTS: All the fifty patients were satisfied with their clinical outcome. The overall complication rate was 4% in this study. The mean visual analog scale score, the affected shoulder active mobility in Ers(external rotation at the side), Era(external rotation in abduction) decreased significantly; the ASES score, Rowe score, Walch-Duplay score improved significantly. CT scans in the sagittal view showed that grafts in 88% of cases were in good position, grafts in 12% of cases were fixed too superiorly and inferiorly. In the axial view grafts in forty cases were flush with the glenoid rim, ten were considered as too lateral. The ten grafts became remodeled and were more flush with the glenoid rim in the follow-up. CONCLUSIONS: The MSB arthroscopic Latarjet procedure provides excellent outcome with few complications, and no degenerative changes were observed in the follow-up. Moreover, the graft fixed too laterally presented a phenomenon of remodeling and became flush with the glenoid rim over time.

Repair of articular cartilage defects with intra-articular injection of autologous rabbit synovial fluid-derived mesenchymal stem cells.

BACKGROUND: The role of rabbit synovial fluid-derived mesenchymal stem cells (rbSF-MSCs) in cartilage defect repair remains undefined. This work evaluates the in vivo effects of rbSF-MSCs to repair knee articular cartilage defects in a rabbit model. METHODS: Cartilage defects were made in the patellar grooves of New Zealand white rabbits. The rbSF-MSCs were generated from the knee cavity by arthrocentesis. Passage 5 rbSF-MSCs were assayed by flow cytometry. The multipotency of rbSF-MSCs was confirmed after 3 weeks induction in vitro and the autologous rbSF-MSCs and predifferentiated rbSF-MSCs were injected into the synovial cavity. The intra-articular injection was performed once a week for 4 weeks. The animals were euthanized and the articular surfaces were subjected to macroscopic and histological evaluations at 8 and 12 weeks after the first intra-articular injection. RESULTS: Hyaline-like cartilage was detected in the defects treated with rbSF-MSCs, while fibrocartilage tissue formed in the defects treated with chondrocytes induced from rbSF-MSCs. CONCLUSIONS: Our results suggest that autologous undifferentiated rbSF-MSCs are favorable to articular cartilage regeneration in treating cartilage defects.

Retinol-binding protein 4 is positively associated with bone mineral density in patients with type 2 diabetes and osteopenia or osteoporosis.

OBJECTIVE: This study intends to study the association between serum retinol binding protein 4 (RBP4), bone mineral density (BMD) and other bone metabolic-related parameters in type 2 diabetic patients older than 50 years, with or without osteopenia or osteoporosis. METHODS: Patients (n = 274 cases) with type 2 diabetes, hospitalized in the Endocrinology Department of Yantai Yuhuangding Hospital from December 2015 to March 2017, were enrolled in the study. The bone mineral density (BMD) was recorded by the dual-energy X-ray absorptiometer, and patients were divided into normal bone mineral density (148 cases), osteopenia (93 cases) and osteoporosis (33 cases) groups. The serum adipokine RBP4 and other biomarkers were determined accordingly. RESULTS: Serum RBP4, body weight, calcium and body mass index (BMI) demonstrated a positive correlation with BMD at all tested body sites in osteopenia and osteoporosis groups compared with normal bone mineral density group. In contrast, age, duration of diabetes and alkaline phosphatase (ALP) were inversely correlated with BMD at all tested body sites. In nonadjusted analyses, age, gender, duration of diabetes and ALP were inversely associated with BMD at the femoral neck, total hip and lumbar spine, while body weight, BMI and RBP4 were positively associated with BMD at all sites. In multiple regression analyses, adjusted for age, weight, BMI and other bone-related factors, a graded stepwise positive association between serum RBP4 and BMD was shown, at all sites. CONCLUSION: Serum RBP4 was positively associated with BMD at all sites after adjustments for other factors in osteopenia and osteoporosis groups compared with normal bone mineral density group of type 2 diabetic patients.

Isolation and characterization of human mesenchymal stem cells derived from synovial fluid by magnetic-activated cell sorting (MACS).

Mesenchymal stem cells (MSCs) are the primary source of cells used for cell-based therapy in tissue engineering. MSCs are found in synovial fluid, a source that could be conveniently used for cartilage tissue engineering. However, the purification and characterization of SF-MSCs has been poorly documented in the literature. Here, we outline an easy-to-perform approach for the isolation and culture of MSCs derived from human synovial fluid (hSF-MSCs). We have successfully purified hSF-MSCs using magnetic-activated cell sorting (MACS) using the MSC surface marker, CD90. Purified SF-MSCs demonstrate significant renewal capacity following several passages in culture. Furthermore, we demonstrated that MACS-sorted CD90+ cells could differentiated into osteoblasts, adipocytes, and chondrocytes in vitro. In addition, we show that these cells can generate cartilage tissue in micromass culture as well. This study demonstrates that MACS is a useful tool that can be used for the purification of hSF-MSCs from synovial fluid. The proliferation properties and ability to differentiate into chondrocytes make these hSF-MSCs a promising source of stem cells for applications in cartilage repair.

Low serum level of epidermal growth factor in chronic ketamine users.

BACKGROUND: Growth factors play an important role in brain development. Whether epidermal growth factor (EGF) plays a role in the pathophysiology of ketamine related disorders is unexplored. In this study, we examined the serum levels of EGF in chronic ketamine users as compared with healthy controls. The possible correlation between serum EGF levels with the demographic, ketamine use characteristics and psychopathological symptoms were analyzed. METHODS: Sixty-seven chronic ketamine users and 40 healthy subjects were recruited. Serum EGF levels were measured by enzyme-linked immunosorbent assay. Psychopathological symptoms were assessed using Positive and Negative Syndrome Scale, Beck Depression Inventory and Beck Anxiety Inventory. RESULTS: The serum level of EGF in the chronic ketamine users was significantly lower than that of healthy subjects (22.34 ± 4.81 pg/ml vs. 87.10 ± 2.96 pg/ml, F = 15.169, p < 0.01). The serum EGF level was negatively correlated with the current average dose of ketamine consumption per day of use (p = 0.015), and positively associated with the Positive and Negative Syndrome Scale positive symptom score (p = .022). CONCLUSIONS: Serum level of EGF decreased in chronic ketamine users compared with healthy subjects, which may play a role in the pathophysiology of ketamine related disorders.