When high PAPR reduction meets CNN: A PRD framework.

One of the most important factors limiting the performance of OFDM (Orthogonal Frequency Division Multiplexing) system is high PAPR (Peak to Average Power Ratio). Great efforts have been made in suppressing PAPR, but their implementation often requires pre-processing all input signals, leading to excessive calculation overhead. When the transmission speed is high, much more time will be taken to process the input signal with the traditional methods, which will reduce the performance of the system. In this background, this paper firstly presents an algorithm, called PRD, to identify the high PAPR sequence without IFFT (Inverse Fast Fourier Transform) operations, in which a CNN (Convolutional Neural Network) for identifying PAPR sequences is trained first before applying further PAPR reduction schemes. Experimental results show that the proposed algorithm can identify the high PAPR sequences with 92.3% accuracy and reduce PAPR with extremely low calculations.

Retraction: Transcription Factor SOX9 Promotes Osteosarcoma Cell Growth by Repressing Claudin-8 Expression.

We reported "Transcription Factor SOX9 Promotes Osteosarcoma Cell Growth by Repressing Claudin-8 Expression" in Tohoku J. Exp. Med., 2017, 241 (1), 55-63; doi: 10.1620/tjem.241.55. After publication of the paper, we have become aware of the ethical violation in collecting the samples from some patients. We therefore wish to retract the paper and apologize for any inconvenience caused by the retraction.

Transcription Factor SOX9 Promotes Osteosarcoma Cell Growth by Repressing Claudin-8 Expression.

Osteosarcoma is a malignant bone cancer that mainly affects children. SOX9 plays a key role in bone formation and osteosarcoma, and Claudin-8 (CLDN8), a tight junction protein, contributes to proliferation of osteosarcoma cells. The aim of this study was to investigate the relationship between SOX9 and CLDN8 in osteosarcoma. The expression levels of SOX9 and CLDN8 were determined in osteosarcoma specimens (n = 25) by qRT-PCR and Western blot analyses. The levels of SOX9 mRNA and protein were significantly higher in osteosarcoma tissues than those in adjacent non-tumor tissues, whereas the expression levels of CLDN8 mRNA and protein were significantly lower in osteosarcoma tissues. Immunohistochemical analysis showed the high expression of SOX9 in 56 out of 97 osteosarcoma tissues (57.7%). By contrast, the low expression of immunoreactive CLDN8 was observed in 62 of 97 osteosarcoma tissues (63.9%). There was the inverse correlation between the expression levels of SOX9 and CLDN8 proteins (R = -0.633, P < 0.001). The overall survival was poorer in the patients with high SOX9 expression. Subsequently, using two human osteosarcoma cell lines, we showed that knockdown of SOX9 inhibited cell proliferation and migration but promoted cell apoptosis. Importantly, knockdown of SOX9 increased the expression levels of CLDN8 protein. The transient luciferase-reporter assays suggest that SOX9 may inhibit the promoter activity of the CLDN8 gene in osteosarcoma cells. In conclusion, we provide the evidence demonstrating that SOX9 may promote cell growth by repressing the expression of CLDN8. Thus, SOX9 may be a therapeutic target for osteosarcoma.

Claudin 8 Contributes to Malignant Proliferation in Human Osteosarcoma U2OS Cells.

Human osteosarcoma (OS) represents one of the most common primary sarcomas often originating in the metaphyses of long bones. However, its underlying molecular pathogenesis is still only vaguely understood. Several tight junction proteins were shown to be associated with and involved in tumorigenesis. This study is aimed to evaluate the role of Claudin 8 (CLDN8) in human OS. Lentivirus-based short hairpin RNA targeting CLDN8 specifically depleted its endogenous expression in U2OS and SW1353 OS cells, with a reduction by 97.7% and 89.3%, respectively, in contrast to control. Depletion of CLDN8 led to a significant diminution in cell viability and proliferation. To test the mechanism by which CLDN8 modulates cell proliferation, the flow cytometry assay and apoptosis assay were performed and confirmed that G1-S transition was blocked and a strong proapoptotic effect was induced in U2OS cells by CLDN8 knockdown. These data demonstrate that CLDN8 plays an essential role in OS proliferation in vitro, which will provide a new opportunity for discovering and identifying novel effective treatment strategies.

Comparison of simple discectomy and instrumented posterior lumbar interbody fusion for treatment of lumbar disc herniation combined with Modic endplate changes.

BACKGROUND: The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion (iPLIF) in patients with lumbar disc herniation and Modic endplate changes. Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc herniation and Modic changes (LDH-MC). METHODS: Ninety-one patients with single-segment LDH-MC were recruited. All patients experienced low back pain as well as radicular leg pain, and low back pain was more severe than leg pain. Forty-seven patients were treated with discectomy and 44 were treated with iPLIF. The outcomes of both low back pain and radicular leg pain using visual analogue scale (VAS) as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association (JOA) score were assessed before and 18 months after surgery, respectively. RESULTS: Both low back and leg pain were significantly improved 18 months after simple discectomy and iPLIF. Compared to patients undergoing simple discectomy, low back pain was significantly reduced in patients undergoing iPLIF, but there was no significant difference in leg pain between two groups. Solid fusion was achieved in all patients who underwent iPLIF. CONCLUSIONS: In patients with LDH-MC, iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy. Simple discectomy can relieve radicular leg pain as efficient as iPLIF. Accordingly, iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.

MicroRNA-142-3p, a novel target of tumor suppressor menin, inhibits osteosarcoma cell proliferation by down-regulation of FASN.

Menin, encoded by MEN1 gene, has been viewed as a tumor suppressor in several types of tumors, such as insulinoma, parathyroid tumor, and adrenocortical and lung carcinoma. However, its expression and molecular regulation mechanism in osteosarcoma has not been elucidated. Here, our results show menin expression is significantly down-regulated in osteosarcoma tissues, compared with adjacent normal tissues. Besides, we report that MicroRNA-142-3p as a novel target of menin. Up-regulation of MicroRNA-142-3p by menin overexpression inhibits cell proliferation in U2OS and MG63 cells. At the molecular level, MicroRNA-142-3p inhibits the protein expression of FASN through binding to its 3'-untranslated region. Therefore, we elucidate a novel regulation pathway in osteosarcoma cells and suggest a potential therapeutic approach for the tumor therapy.

MicroRNA-32 inhibits osteosarcoma cell proliferation and invasion by targeting Sox9.

Increasing reports suggest that discovery of microRNAs (miRNAs) might provide a novel therapeutical target for human cancers, including osteosarcoma. Previous studies have shown that miR-32 was dysregulated in breast and endometrial cancer. However, its biological roles in osteosarcoma remain unclear. In the current study, we found that miR-32 was significantly down-regulated in osteosarcoma tissues, compared with the adjacent normal tissues. In vitro studies further demonstrated that miR-32 mimics were able to suppress, while its antisense oligos promoted cell proliferation in Saos-2 and U2OS cells. At the molecular level, our data further revealed that expression of Sox9 was negatively regulated by miR-32. Therefore, our results identify an important role for miR-32 in the osteosarcoma through regulating Sox9 expression.

Hydrothermal preparation and characterization of ultralong strontium-substituted hydroxyapatite whiskers using acetamide as homogeneous precipitation reagent.

The ultralong strontium- (Sr-) substituted hydroxyapatite (SrHAp) whiskers were successfully prepared using acetamide as homogeneous precipitation reagent. The effect of the Sr substitution amount on the lattice constants and proliferation of human osteoblast cells (MG-63) was further investigated. The results showed that the SrHAp whiskers with diameter of 0.2-12 µm and ultralong length up to 200 µm were obtained and the Sr substitution level could be facilely tailored by regulating the initial molar ratio of Sr/(Sr + Ca) in raw materials. The Sr(2+) replaced part of Ca(2+) and the lattice constants increased apparently with the increase of the Sr substitution amount. Compared with the pure HAp whiskers, the Sr substitution apparently stimulated the proliferation of MG-63 at certain extracted concentrations. Our study suggested that the obtained SrHAp whiskers might be used as bioactive and mechanical reinforcement materials for hard tissue regeneration applications.

The outcome of surgical treatment for recurrent giant cell tumor in the appendicular skeleton.

BACKGROUND: The treatment for recurrent giant cell tumor (GCT) remains controversial. In this study, we evaluated the outcome of surgical intervention for recurrent GCT. METHOD: Twenty-seven patients (14 males and 13 females) with recurrent GCT were recruited. Their primary GCTs were all treated with intralesional surgery. Among these recurrent GCTs, 9 grade III and 1 grade II tumors were treated with en bloc resection and endoprosthetic replacement, whereas 16 grade II and 1 grade III tumors were treated with intralesional curettage and PMMA bone cement filling. RESULTS: The mean interval between initial surgery and first recurrence was 28.8 months (range 7-97 months). About 70 % of first recurrences affected bones around the knee, 44 % in the proximal tibia and 26 % in the distal femur. Of 27 patients, 3 women treated with intralesional procedures suffered second recurrences in the proximal tibia. No second recurrence was found in patients with en bloc resection. Two grade III re-recurrence GCTs were treated with en bloc resection, and 1 grade II was treated with an intralesional procedure. One patient with en bloc resection developed tumor metastasis in both lungs. Compared to patients with intralesional treatment, the functional score was significantly decreased in patients with en bloc resection (p < 0.01). CONCLUSION: The re-recurrence risk of grade III GCTs can be significantly decreased by wide en bloc resection and endoprosthetic replacement. However, intralesional treatment is a good option for less aggressive (

Intradiscal injection therapy for degenerative chronic discogenic low back pain with end plate Modic changes.

BACKGROUND CONTEXT: The effect of intradiscal steroid therapy for patients with degenerative chronic discogenic low back pain remains an issue of debate. PURPOSE: To evaluate the effect of various intradiscal injection regimens for patients with degenerative chronic discogenic low back pain and end plate Modic changes. STUDY DESIGN: Double-blind, randomized, controlled, prospective clinical study. PATIENT SAMPLE: One hundred twenty patients with discogenic low back pain and end plate Modic changes on magnetic resonance imaging (MRI) who received discography but were unwilling to accept surgical operation. OUTCOME MEASURES: Pain and function were determined by the visual analog scale (VAS) and the Oswestry Disability Index (ODI) assessment. METHODS: Patients who received diagnostic discography for suspected degenerative discogenic low back pain were recruited. A total of 120 patients with positive discography and end plate Modic changes at a single level were enrolled in the study and allocated into Groups A and B according to the type of Modic changes on MRI. Then, the patients in Groups A and B were randomized into three subgroups, respectively. Intradiscal injection of normal saline was performed in Subgroups A1 and B1, intradiscal injection of diprospan was performed in Subgroups A2 and B2, and intradiscal injection of a mixed solution of diprospan+songmeile (cervus and cucumis polypeptide) was performed in Subgroups A3 and B3. The clinical outcome of each patient was evaluated and recorded by using the VAS and ODI at 3 and 6 months after the procedure. RESULTS: The subgroups were comparable with respect to gender, age, pain, and percentage disability. Neither VAS pain scores nor Oswestry function scores of the patients within Group A had any improvement at 3 or 6 months after saline injection, but both of them improved significantly at the two time points after diprospan and diprospan+songmeile injection, respectively. Meanwhile, the latter two injection protocols led to no significant difference in pain relief and functional recovery. Similar results were obtained in patients within Group B. Furthermore, no difference of the improvement of VAS pain scores or Oswestry function scores was found between the patients within Group A and within Group B at different time points after various interventions. CONCLUSION: Intradiscal injection of corticosteroids could be a short-term efficient alternative for discogenic low back pain patients with end plate Modic changes on MRI who were still unwilling to accept surgical operation when conservative treatment failed.

[Selection of surgical methods for lumbar disc herniation with degenerative endplates changes].

OBJECTIVE: To analyze the selection of surgical methods for lumbar disc herniation with low back and leg pain and degenerative lumbar Modic endplate changes and their different postoperative therapeutic effects. METHODS: All 30 cases of single segment lumbar disc herniation accompanied by Modic endplate changes operated at our hospital using simple discectomy or decompressions with interbody fusion from January 2005 to January 2008 were retrospectively identified. There were 18 males and 12 females with an average age of 38.5 years old (26-53 years old) and an average follow-up of 21 months (4-40 months). RESULTS: Discectomy alone group included 15 cases. The average score of Japanese Orthopedics Association (JOA) and visual analysis scale (VAS) of low back pain and lower extremity radicular pain at the preoperative and final follow-up time was 13.2 (5-17), 6.8 (4-10), 4.8 (1-8) and 19.8 (14 -24), 4.8 (2-10), 1.2 (0-6) respectively. The average improvement rate of JOA was 41.9%. The difference of VAS of lower extremity radicular pain between pre and post-operation was 3.7 on average. Among these 15 cases, Modic I, II and I/II mixed-type was 5, 9, and 1 respectively. Decompression with interbody fusion group included 15 cases. VAS of low back pain and lower extremity radicular pain at the preoperative and final follow-up time was 12.9 (5-17), 7.0 (4-10), 4.9 (1-8) and 22.6 (19-28), 2.8 (2-8) and 1.3 (0-6) respectively. The average improvement rate of JOA was 63.4%. The differences of VAS of lower extremity radicular pain and low back pain between pre and post-operation were 4.3 and 3.6 on average respectively. Among these cases, Modic I, II and I/II mixed-type was 6, 8, and 1 respectively. Comparing the VAS of low back pain, JOA average score and the improvement rate of JOA score of two groups at pre-operation and post-operation, statistical analysis showed that decompression with interbody fusion group was superior to simple discectomy group. CONCLUSION: For lumbar disc herniation with degenerative Modic endplate changes, who suffered more from low back pain than lower extremity radicular pain, discectomy alone and decompression with interbody fusion could both improve the degree of lower extremity radicular pain, but discectomy alone is less likely to improve the degree of low back pain and function score than the latter. So the maneuver of lumbar decompression with fusion is a better choice.

[Intradiscal interventional therapy for degenerative chronic discogenic low back pain with end-plate Modic changes].

OBJECTIVE: To observe the different efficacies of intradiscal interventional therapy for patients with degenerative chronic discogenic low back pain and end-plate Modic changes through different types of injection and to evaluate the potential therapeutic value of intradiscal injection treatment for degenerative chronic discogenic low back pain with different types of end-plate Modic changes by using appropriate injection. METHODS: Patients with single segmental degenerative chronic discogenic low back pain proved by discography were classified as Modic type I predominant change (including Modic Type I & Modic type I predominant mixed Type I/II) and Modic type II predominant change (including Modic Type II & Modic Type II predominant mixed Type II/I) according to the end-plate Modic changes on MRI. All received the intradiscal injection treatment. Patients were divided into three groups: (1) A group (control group): intradiscal injection of normal saline 3 ml; (2) B group (treatment group): intradiscal injection of diprospan (compound betamethasone) 3 ml; (3) C group (treatment group): interventional injection of diprospan (compound betamethasone) 1 ml + songmeile (cervus & cucumis polypeptide injection) 2 ml. Pain and function were evaluated by pain visual analogue scale (VAS) and Oswestry disability index (ODI). T-test was applied for efficacy comparison in each group at pre-operation, 3 months and 6 months post-operation. RESULTS: Sixty patients were included. There were 39 males and 21 females with a mean age of 41.6 years old (26 - 58). There were 10 patients in each group: A-Modic I, A-Modic II; B-Modic I, B-Modic II; C-Modic I, C-Modic II. There was no significant statistical difference in preoperative VAS and Oswestry scores among groups; VAS and Oswestry scores of B group and C group at 3 months and 6 months post-operation were significantly better than those pre-operative scores, and also better than that of control group (A group) at the same time. But there was no significant difference in scores between 3 months and 6 months in ether B group or C group, and there was also no significant difference in VAS and Oswestry scores between B group and C group at various time points. Various Modic types had no correlation with either VAS score or Oswestry score in each group at various time points. CONCLUSION: Intradiscal interventional therapy can relieve discogenic low back pain and improve Oswestry disability index score of function between 3 and 6 months post-operation. There is no significant difference in post-operative efficacy between Modic Type I and Modic Type II. Steroids are the major analgesic factor of intradiscal injection. But the synergistic application of songmeile (cervus & cucumis polypeptide injection) can maintain the analgesic effect and duration with a decreased dose of steroids.