The v-DECAF score can predict 90-day all-cause mortality in patients with COPD exacerbation requiring invasive mechanical ventilation.

INTRODUCTION: The DECAF score is a simple and effective tool for predicting mortality in patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease (AECOPD); however, the DECAF score has not been validated in AECOPD patients requiring invasive mechanical ventilation (IMV). We devised the ventilator (v)-DECAF score, in which "anemia" replaces "acidaemia," for use in AECOPD patients requiring IMV. The objective of this study was to compare the predictive efficacy of the v-DECAF score and the DECAF score. METHODS: This study prospectively recruited 112 consecutive AECOPD patients requiring IMV from a single center. The clinical endpoint was 90-day all-cause mortality. Demographic and clinical data were recorded, as well as APACHE II, GCS, CURB-65, BAP-65 and DECAF scores, and the newly devised v-DECAF score. The discriminatory value of the scoring systems in predicting 90-day all-cause mortality was determined using the area under the receiver operating characteristic (AUROC) curve. RESULTS: In multivariate logistic regression analysis, the v-DECAF score was an independent predictor of 90-day all-cause mortality (odds ratio 3.004, 95% CI 1.658-5.445, P < 0.001). The AUROC of the v-DECAF and DECAF scores were 0.852 (95% CI 0.766-0.938) and 0.777 (95%CI: 0.676-0.878), respectively. The v-DECAF score had a better predictive value for 90-day all-cause mortality compared to the DECAF score (Z = 2.338, P = 0.019). CONCLUSION: The v-DECAF score had good discriminatory power in predicting 90-day all-cause mortality in AECOPD patients requiring IMV.

Protective Effect of Anthocyanin on Paraquat-Induced Apoptosis and Epithelial-Mesenchymal Transition in Alveolar Type II Cells.

BACKGROUND Paraquat (PQ) can over-accumulate in alveolar epithelial cells. Anthocyanin (An) can exert anti-oxidative properties. The role of An in PQ-induced toxicity is unclear, so we aimed to explore whether An could inhibit epithelial mesenchymal transition (EMT) induced by PQ in alveolar cells. MATERIAL AND METHODS lveolar epithelial cells were treated with PQ and An with concentration gradient for 12, 24, and 48 h. The cell viability, ROS level, and apoptosis rate were determined using the Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. The lactate dehydrogenase (LDH) leakage, methane dicarboxylic aldehyde (MDA) level, glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities were determined by spectrophotometric method. The mRNA and protein expressions were detected using quantitative real-time PCR (qPCR) and Western blot, respectively. RESULTS An reduced the PQ-induced apoptosis in a dose-dependent manner. Moreover, An reduced the ratio of Bax/Bcl-2 to ROS level. We found that An suppressed the activity of LDH and MDA and improved SOD and GPX levels. Additionally, the level of PQ-induced E-cadherin was decreased by An while the expressions of vimentin, α-smooth muscle actin (α-SMA), and collagens type I (col-I) were increased. Furthermore, An inhibited the levels of transforming growth factor ß1 (TGF-ß1) and activin receptor-like kinase 5 (ALK5) and reduced the phosphorylation of smad2. CONCLUSIONS Our study shows newly discovered effects of anthocyanidins on EMT and supports their chemopreventive effects in paraquat-induced apoptosis in alveolar type II cells.

Time-series expression profile analysis of fracture healing in young and old mice.

Bone fracture healing is a complex process, which is associated with several factors, including age and osteoporosis. Certain genes and biological processes that may contribute to fracture healing, have been identified following developments in systems biology and molecular biology technologies, which may benefit the treatment of bone fractures. The present study identified key genes, which may be important in fracture healing through bioinformatics analysis of gene microarray datasets from the Gene Expression Omnibus. Gene clusters, which were consistently up/downregulated through time following a fracture in young (6­week­old) mice and old (8­month­old retired breeders) mice were obtained via soft clustering of differentially expressed genes (DEGs) between samples at 1 and 3 days, 1 and 5 days, and 3 and 5 days post­fracture in the two age groups, based on the Mfuzz package of R. Functional enrichment analysis of gene clusters using the Database for Annotation, Visualization and Integrated Discovery indicated that biological processes and pathways, including those associated with bone development, skeletal system development, amino sugar and nucleotide sugar metabolism, were significantly enriched in these up/downregulated genes. Of note, a total of 207 overlapped consistently upregulated genes were obtained between the two age groups, whereas no overlap was identified between the two lists of consistently downregulated genes. The overlapped genes were found to be associated with the biological processes of blood vessel development, vasculature development and skeletal system development, compared with all genes in the clusters. In addition, certain genes, including epidermal growth factor­like domain multiple 6 (EGFL6), kazal­type serine peptidase inhibitor domain 1 (KAZALD1), olfactomedin 2B (OLFM2B), collagen type III α1 (COL3A1), collagen type II α1 (COL2A1), von Willebrand factor A domain­containing 1 (VWA1), elastin microfibril interfacer 1 (EMILIN1) and aggrecan (ACAN), of the extracellular matrix organization, a process performed at the cellular level and resulting in the assembly and arrangement of constituent parts, were confirmed to be associated with fracture healing via reverse transcription­quantitative polymerase chain reaction analysis. The present study identified certain genes and biological processes/pathways, which may be associated with fracture healing and may assist in fundamental investigations and treatment in the future.

Palladium-Catalyzed sp2-sp3 Coupling of Chloromethylarenes with Allyltrimethoxysilane: Synthesis of Allyl Arenes.

Palladium-catalyzed remote sp2-sp3 coupling reaction of chloromethylarenes with allyltrimethoxysilane is described in this work. The allylation reaction regioselectively occurred on the para-positions of 1-(chloromethyl)naphthalenes and benzyl chlorides to form new C(sp2)-C(sp3) bonds. The reaction proceeds smoothly under mild conditions to produce allyl arenes in moderate to excellent yields.

A MicroRNA-124 Polymorphism is Associated with Fracture Healing via Modulating BMP6 Expression.

BACKGROUND: miR-124-3p has been reported to be involved in the pathogenesis of many diseases by modulating a variety of signaling pathways. In this study, we aimed to understand the impact of miR-124-3p expression level on the fracture healing in the patients of metaphyseal fracture of distal tibia, who received minimal invasive percutaneous plate osteosynthesis. METHODS: We firstly collected 195 patients of metaphyseal fracture of distal tibia, and the genotype of rs531564 was determined: GG (n=124) and GC+CC (n=71). We collected information of the participants including age, gender, total in-hospital time, smoking and alcohol consumption. Subsequently, we searched the miRNA database online to identify the possible binding sequence of miR-124-3p located within the 3'-UTR of the target gene. We did correlation analysis and luciferase to understand the regulatory relationship between miR-124-3p and BMP6. Meanwhile, we also conducted real time PCR and western blotting analysis to study the mRNA and protein expression level of BMP6 in different genotype groups. We then treated the cells with scramble control, miR-124-3p mimics, BMP6 siRNA and miR-124-3p inhibitors to investigate the influence of miR-124-3p on the expression of BMP6, viability and apoptosis of cells. RESULTS: Total in-hospital time was significantly longer in GC+CC group than GG group. MiR-124-3p was up-regulated in GG group than GC and CC groups. BMP6 was virtual target of miR-124-3p. There existed negative regulatory relationship betweenmiR-124-3p and BMP6. The mRNA and protein expression level of BMP6 decreased in GG group. MiR-124-3p decreased the expression of BMP6. MiR-124-3p negatively interfered with the viability of cells and BMP6 positively interfered with the viability of cells. MiR-124-3p reduced apoptosis and BMP6 promoted apoptosis. CONCLUSION: These data proved the expression of miR-124-3p was associated with the healing of metaphyseal fracture of distal tibia, and could be recognized as a biomarker to predict the healing of metaphyseal fracture of distal tibia.

Relationship between PI3K pathway and angiogenesis in CIA rat synovium.

To investigate the expression of hypoxia inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF) in the synovium of collagen-induced arthritis (CIA) joint, and whether the PI3K pathway regulates angiogenesis in rheumatoid arthritis or not. A randomized controlled according to the principle of the rats were divided into normal control group (10 rats) and the experimental group (40 rats). The experimental group rats were established as type II collagen plus adjuvant Freund's complete adjuvant-induced arthritis model. HIF-1α and VEGF proteins' expression in serum of CIA rats group and normal control group were detected by ELISA. Microvessel density (MVD) in synovial tissue of CIA rats group and normal control group were detected by immunohistochemistry (IHC) staining. The protein expression of PTEN, PI3K, and AKT in synovial tissue were detected by Western Blot. Compared with normal control group, toes and ankle swelling and arthritis index (AI) of CIA rat increased, and the expression of VEGF and HIF-1α proteins in peripheral serum increased, IHC showed that MVD was significantly higher than that of the control group, and the difference was statistically significant (p<0.05). Western Blot results showed that PI3K and AKT proteins expression in CIA synovial tissue of rats increased, while the expression of PTEN protein decreased. Correlation analysis showed that VEGF and HIF-1 levels in the peripheral serum of CIA rats were positively correlated with arthritis index (AI); the contents of HIF-1α and VEGF in the peripheral serum of CIA rats were positively correlated with MVD in synovium tissue. The CIA rat model regulated the expression of HIF-1α and VEGF proteins in peripheral serum by PI3K signaling pathway, and then regulated neovascularization in RA.

Caveolin-1 is critical in the proliferative effect of leptin on osteoblasts through the activation of Akt.

Osteoblasts are critical in bone remodeling and the repair of bone fractures. Leptin is involved in bone metabolism and osteoblast survival through the downstream signaling pathway, however, the exact mechanism of the effect of leptin on osteoblasts remains to be fully elucidated. In the present study, hFOB 1.19 cells were used to observe the effects of leptin on cell proliferation and apoptosis, and to investigate the underlying mechanism. The results confirmed that treatment of hFOB 1.19 cells with leptin significantly induced cell proliferation. Western blot analysis showed that the expression of caveolin­1 and the activation of Akt in the cells treated with leptin were significantly increased, compared with the control cells. Additionally, inhibiting Akt activation eliminated the effects on cell proliferation induced by leptin. The rates of cell apoptosis and cell cycle distribution were examined using flow cytometry, which revealed a decrease in the apoptotic rate and an increase in the proportion of cells in the S phase. This indicated that leptin was capable of inducing cell proliferation by inhibiting apoptosis and stimulating cell progression to the S phase. Transfection of the cells with caveolin­1 small interfering RNA showed that the activation of Akt induced by leptin was significantly inhibited. Furthermore, caveolin­1 knockdown and inhibiting Akt activation eliminated the increased proliferation, increased proportion of cells in the S phase and increased anti­apoptotic effects induced by leptin. Taken together, the data obtained in the present study demonstrated that caveolin­1 was critical in the proliferative effect of leptin on osteoblasts via the activation of Akt.

MiR-19 suppresses fibroblast-like synoviocytes cytokine release by targeting toll like receptor 2 in rheumatoid arthritis.

Fibroblast-like synoviocytes (FLS) play an important role in the pathogenesis of rheumatoid arthritis (RA) through participating in joint tissue inflammation and joint damage. MicroRNAs are a kind of small non-coding RNAs that can regulate gene expression in the transcription level to affect cell behaviors. This study intended to investigate the expression of miR-19 in FLS from RA patients and related mechanism. A total of 126 RA patients were selected in this study. MiR-19 expression in FLS was detected by qRT-PCR. Toll like receptor 2 (TLR2) protein expression was tested by Western blot. MiR-19 target genes were confirmed by bioinformatics analysis and luciferase reporter assay. The impact of miR-19 on the expression of TLR2, interleukin 6 (IL-6), and matrix metalloproteinase 3 (MMP-3) in FLS were analyzed by cell transfection and Western blot. MiR-19 expression in FLS from RA patients was significantly downregulated compared with control (P < 0.05), while TLR2 level was increased (P < 0.05). Bioinformatics analysis and luciferase reporter assay confirmed that TLR2 was the target gene of miR-19. Transfection of miR-19 mimic or miR-19 inhibitor obviously suppressed or increased TLR2 expression, and reduced or promoted release of cytokines IL-6 and MMP-3 in FLS, respectively. In conclusion, MiR-19 expression was downregulated in FLS from RA patients, leading to increased TLR2 expression and enhanced cytokines release.

[EFFECTIVENESS OF POSTEROMEDIAL DOUBLE PLATES IN TREATMENT OF COMPLEX OLECRANAL FRACTURE].

OBJECTIVE: To evaluate the effectiveness of posteromedial double plates in the treatment of complex olecranal fracture. METHODS: Between September 2011 and July 2015, 13 patients with complex olecranal fractures were treated with posterior olecranon locking compression plate and medial mini-plate. There were 8 males and 5 females with an average age of 41.6 years (range, 22-68 years). Injury was caused by traffic accident in 4 cases, falling from height in 6 cases, and crush by object in 3 cases. According to the Mayo classification, fracture was rated as Mayo type ⅡB in 5 cases and as Mayo type ⅢB in 8 cases. Of 13 cases, 7 had Regan-Morrey type Ⅲ coronoid fractures, including 5 anterior dislocations of the elbow joint and 2 posterior dislocations. The time between injury and admission ranged from 1.5 to 10.0 hours (mean, 5.7 hours). At last follow-up, the elbow function was assessed according to the Broberg-Morrey evaluation criteria. X-ray films was performed to observe fracture healing. RESULTS: All incisions healed at first stage and no neural complications occurred. The patients were followed up 9-38 months (mean, 22.1 months). All patients achieved bone union at 3.0-5.5 months (mean, 3.7 months) according to X-ray results. Subluxation of radial head and mild heterotopic ossification occurred in 1 patient respectively, who had no uncomfortable symptoms of movement disorder, elbow instability and pain, and no special management was performed. At last follow-up, the flexion and extension range of motion (ROM) of the elbow was 95-130° (mean, 116.4°); the rotation ROM of the forearm was 150-175° (mean, 170.8°); and the elbow function was excellent in 4 cases, good in 7 cases, and fair in 2 cases, and the excellent and good rate was 84.6%. No internal fixation failure, elbow stiffness, or traumatic arthritis occurred. CONCLUSIONS: For complex olecranal fractures, an early and stable anatomic reconstruction of trochlear notch in the olecranon with posterior olecranon locking compression plate and medial mini-plate can obtain good effectiveness in joint functions.

X609, a novel manassantin A derivative, exhibits antitumor activity in MG-63 human osteosarcoma cells in vitro and in vivo.

Manassantin A has been well-established as an inhibitor of HIF-1. In the present study, a new manasantin A derivative, X609, with decreased stereochemical complexity, rendering it amenable to a simplified synthesis scheme, was synthesized and was found to increase HIF-1 inhibitory activity. X609 exhibited antiproliferative activity in a broad spectrum of tumor cell lines, via HIF-1-dependent mechanisms. X609 may induce apoptosis in MG-63 cells through activation of the mitochondrial pathway. Oral administration of X609 significantly inhibited the growth of human osteosarcomas implanted into nude mice. In light of the results of the present study, it may be possible to develop X609 for use as a novel antitumor agent, which targets human osteosarcoma.

The association between the ACTN3 R577X polymorphism and noncontact acute ankle sprains.

Ankle sprains are one of the most severe musculoskeletal soft tissue injuries during physical activity. Although many risk factors have been offered, it is unclear why some individuals develop noncontact ankle sprains when participating in comparable levels of physical exertion under identical environmental conditions and others do not. The ACTN3 gene that encodes the α-actinin-3 protein, which is, only expressed in the Z line of fast glycolytic muscle fibres was found to associate with power/strength performance. The aim of this study was therefore to investigate whether the ACTN3 gene polymorphism is associated with noncontact acute ankle sprains. One hundred and forty-two participants with clinically diagnosed noncontact acute ankle sprains as well as 280 physically active controls participants without any history of ankle sprains were included in this case-control genetic association study. The RR genotype (odds ratio (OR) = 0.56; 95% confidence interval (CI), 0.32-0.65, P = 0.011) and R allele (OR = 0.64; 95% CI, 0.37-0.68, P = 0.002) of the ACTN3 were significantly low-represented in the acute ankle sprains group compared with the control group. The ACTN3 R577X is associated with acute ankle sprains in Chinese participants in this study. This is the first study to suggest that an individual with a RR genotype is at a decreased risk of acute ankle sprains.

Morphology study of thoracic transverse processes and its significance in pedicle-rib unit screw fixation.

BACKGROUND: Thoracic transverse process is an important anatomic structure of the spine. Several anatomic studies have investigated the adjacent structures of the thoracic transverse process. But there is still a blank on the morphology of the thoracic transverse processes. The purpose of the cadaveric study is to investigate the morphology of thoracic transverse processes and to provide morphology basis for the pedicle-rib unit (extrapedicular) screw fixation method. METHODS: Forty-five adult dehydrated skeletons (T1-T10) were included in this study. The length, width, thickness, and the tilt angle (upward and backward) of the thoracic transverse process were measured. The data were then analyzed statistically. On the basis of the morphometric study, 5 fresh cadavers were used to place screws from transverse processes to the vertebral body in the thoracic spine, and then observed by the naked eye and on computed tomography scans. RESULTS: The lengths of thoracic transverse processes were between 16.63±1.59 and 18.10±1.95 mm; the longest was at T7, and the shortest was at T10. The widths of thoracic transverse processes were between 11.68±0.80 and 12.87±1.48 mm; the widest was at T3, and the narrowest was at T7. The thicknesses of thoracic transverse processes were between 7.86±1.24 and 10.78±1.35 mm; the thickest was at T1, and the thinnest was at T7. The upward tilt angles of thoracic transverse processes were between 24.9±3.1 and 3.0±1.56 degrees; the maximal upward tilt angle was at T1, and the minimal upward tilt angle was at T7. The upward tilt angles of T1 and T2 were obviously different from the other thoracic transverse processes (P<0.01). The backward tilt angles of thoracic transverse processes gradually increased from 24.5±2.91 degrees at T1 to 64.5±5.12 degrees at T10. The backward tilt angles were significantly different between each other, except between T5 and T6. In the validation study, screws were all placed successfully from transverse processes to the vertebrae of thoracic spine. CONCLUSIONS: The length, width, and thickness of the thoracic transverse processes are suitable for screw placement. And the obvious upward and backward tilt angles provide an excellent screw passage from transverse process to the vertebral body. Screw placement from the transverse processes to the vertebral body is feasible in the thoracic spine. However, there is still some place for improvement of the pedicle-rib unit screw fixation method.

Reconstruction of weightbearing forefoot defects with digital artery flaps.

Reconstruction of a defect of the weightbearing forefoot region remains a challenging problem owing to the limited alternatives available. The digital artery flap can be used for coverage of defects in the weightbearing forefoot. The present study reports our results using a digital artery flap for reconstruction of soft tissue defects of the weightbearing forefoot in 8 patients. The mean patient age was 35 ± 11.3 years. The etiology of the soft tissue defects included 4 (50%) traumatic events, 2 (25%) dysfunctional scars, and 2 (25%) neuropathic ulcerations. The mean postoperative follow-up duration was 22 ± 11.1 months (range 12 months to 4 years). All 8 flaps survived successfully. The complications included 1 case of delayed healing of a neuropathic ulceration. The digital artery flap is a good alternative for soft tissue defects of the weightbearing forefoot. The surgical techniques for harvesting the flaps are easy to manage.

Heel reconstruction with free instep flap: a case report.

INTRODUCTION: Reconstruction of weight-bearing heel defects remains a challenge because of the unique characteristics of the plantar skin. Though numerous surgical reconstructive options have been reported, the instep flap represents an ideal option and seems to be more acceptable to patients than others. However, when the heel defect expands to the instep area, the ipsilateral instep is not available for flap elevation. A free instep flap harvested from the contralateral foot can be a good solution, but this method has been scarcely reported. CASE PRESENTATION: A 41-year-old Asian man presented to our institution with a soft-tissue lesion in the weight-bearing heel and instep area. His heel was reconstructed with a free instep flap from the other foot, end-to-side anastomosis of its medial plantar artery to the recipient posterior tibial artery and end-to-side coaptation of the cutaneous sensory fascicles of the flap to the medial plantar nerve. CONCLUSION: The flap survived successfully, and no ulceration occurred in the flap. At the last follow-up appointment at 30 months post-surgery, a very good functional and aesthetic outcome was verified, indicating that the suggested approach may prove to be the treatment of choice in selected cases of weight-bearing heel reconstruction.

The extended distally based sural neurocutaneous flap for foot and ankle reconstruction: a retrospective review of 10 years of experience.

The distally based sural neurocutaneous flap has been used for coverage of defects in foot and ankle for years. Conventional flaps do not extend to the upper third of the leg, which limits its application. The current study presents results using extended distally based sural neurocutaneous flaps for reconstruction of extensive soft tissue defects of the foot and ankle in 21 patients. All injuries occurred from 2001 to 2011 as a result of a traumatic event. Follow-up of 21 patients ranged from 7 months to 5 years after surgery. All 21 flaps survived successfully. The largest flap used measured 26 × 15 cm. Complications included 1 distal marginal necrosis and 2 slight venous congestions. The extended distally based sural neurocutaneous flap is a good alternative for extensive soft tissue defects of foot and ankle. The operative techniques with several simple modifications in harvesting the flaps are easy to handle and will not prolong the operation time.

P2X4 promotes interleukin­1ß production in osteoarthritis via NLRP1.

Interleukin­1ß (IL­1ß) has a significant role in osteoarthritis (OA). The purinergic receptor, P2X4, has previously been implicated in IL­1ß secretion. The NLRP1 inflammasome mediates the production of IL­1ß in inflammatory disorders. However, it is unknown whether P2X4 modulates NLRP1­mediated IL­1ß release. In the present study, the correlation between the P2X4 receptor and NLRP1 was investigated in OA fibroblast­like synoviocytes (OAFLS). The expression of P2X4 and NLRP1 was detected in the OAFLS. The OAFLS were stimulated with P2X4 and the levels of IL­1ß and matrix metalloproteinases (MMPs) were measured. To determine whether P2X4 is involved in NLRP1­triggered IL­1ß production, NLRP1 small interfering RNA (siRNA) was used. In the OAFLS, a markedly higher expression of P2X4 and NLRP1 was revealed compared with that in the normal FLS. OAFLS stimulated by P2X4 resulted in concentration­dependent increases in the production of IL­1ß, MMP­3 and MMP­9. Furthermore, P2X4­mediated IL­1ß production was attenuated by the NLRP1 siRNA. The results of the present study indicate that P2X4 induced IL­1ß, MMP­3 and MMP­9 production in the OAFLS. IL­1ß induced by P2X4 is mediated via NLRP1. P2X4/NLRP1 may be important in the pathogenesis of OA and may represent a novel therapeutic target.

Extended anterolateral thigh flaps for reconstruction of extensive defects of the foot and ankle.

The anterolateral thigh flap has been used for coverage of defects in the foot and ankle for years. Conventional extended anterolateral thigh flaps do not undergo thinning procedures, which limit their application. Here, a clinical series of 24 patients is reported in which extended anterolateral thigh flaps were used for posttraumatic foot and ankle reconstruction. Of the 24 flaps, 14 were simple extended anterolateral thigh fasciocutaneous flaps and 10 were thinned extended anterolateral thigh flaps. One artery and two veins, including a superficial vein and an accompanying vein, were anastomosed to vascularize each flap. Follow-up of the 24 patients ranged from 10 months to 4 years postoperatively. All 24 flaps survived successfully, except one case that had partial flap necrosis distally due to excessive thinning. The cutaneous flap territory ranged from 250 cm(2) to 400 cm(2) (mean, 297 cm(2)). Only one patient received a debulking procedure. No ulceration occurred in any of the flaps due to contact with the shoe. The extended anterolateral thigh flap is a good alternative for extensive soft tissue defects of the foot and ankle. This study also supports the high reliability and excellent vascular supply of moderate thinned extended ALT flaps.

The distally based superficial sural flap for reconstruction of the foot and ankle in pediatric patients.

The distally based superficial sural flap has been used for coverage of defects in the foot and ankle for years. However, little attention has been received in the pediatric trauma population because of small sample volumes. The current study presents results using distally based superficial sural flaps for reconstruction of soft tissue defects of the foot and ankle in children. A retrospective study was performed to assess outcomes of 32 pediatric patients with defects of the foot and ankle requiring soft tissue coverage using distally based superficial sural flaps. The average patient age was 9 years. The etiology of the soft tissue defects included 31 traumatic events and 1 chronic ulcer with bone, tendon, or joint lesion exposure. Postoperative follow-up of the 32 patients ranged from 11 months to 7 years. All 32 flaps survived successfully. Complications included one wound dehiscence and three slight venous congestions. The distally based superficial sural flap is a good alternative for soft tissue defects of the foot and ankle in children. The surgical techniques in harvesting the flaps are easy to handle.

CD133 expression in osteosarcoma and derivation of CD133⁺ cells.

Cluster of differentiation 133 (CD133) is recognized as a stem cell marker for normal and cancerous tissues. Using cell culture and real­time fluorescent polymerase chain reaction, CD133 expression was analyzed in osteosarcoma tissue and Saos­2 cell lines. In addition, cancer stem cell­related gene expression in the Saos­2 cell line was determined to explore the mechanisms underlying tumorigenesis and high drug resistance in osteosarcoma. CD133+ cells were found to be widely distributed in various types of osteosarcoma tissue. Following cell culture, cells entered the G2/M and S cell cycle stages from G0/G1. Levels of CD133+ cells decreased to normal levels rapidly over the course of cell culture. Colony forming efficiency was higher in the CD133+ compared with the CD133­ subpopulation of Saos­2 cells. Expression levels of stem cell­related genes, including multidrug resistance protein 1 (MDR1) and sex determining region Y­box 2 (Sox2) in the CD133+ subpopulation of cells were found to be significantly higher compared with the CD133­ subpopulation. These observations indicate that CD133+ Saos­2 cells exhibit stem cell characteristics, including low abundance, quiescence and a high potential to undergo differentiation, as well as expression of key stem cell regulatory and drug resistance genes, which may cause osteosarcoma and high drug resistance.