Staphylococcus aureus enterotoxin b down-regulates the expression of transforming growth factor-beta (TGF-β) signaling transducers in human glioblastoma

Background: It has been revealed that Staphylococcus aureus enterotoxin B (SEB) may feature anti-cancer and anti-metastatic advantages due to its ability to modify cell immunity processes and signaling pathways. Glioblastoma is one of the most aggressive human cancers; it has a high mortality nature, which makes it an attractive area for the development of novel therapies. Objectives: We examined whether the SEB could exert its growth inhibitory effects on glioblastoma cells partially through the manipulation of a key tumor growth factor termed transforming growth factor-beta (TGF-β). Materials and Methods: A human primary glioblastoma cell line, U87, was treated with different concentrations of SEB. The cell quantity was measured by the MTT assay at different exposure times. For molecular assessments, total ribonucleic acid (RNA) was extracted from either non-treated or SEB-treated cells. Subsequently, the gene expression of TGF-β transducers, smad2/3, at the messenger RNA (mRNA) level, was analyzed via a quantitative real-time polymerase chain reaction (qPCR) using the SYBR Green method. Significant differences between cell viability and gene expression levels were determined (Prism 5.0 software) using a one-way analysis of variance (ANOVA) test. Results: We reported that SEB could effectively down-regulate smad2/3 expression in glioblastoma cells at concentrations as quantity as 1 µg/mL and 2 µg/mL (P < 0.05 and P < 0.01, respectively). The SEB concentrations effective at regulating smad2/3 expression were correlated with those used to inhibit the proliferation of glioblastoma cells. Our results also showed that SEB was able to decrease smad2/3 expression at the mRNA level in a concentration- and time-dependent manner. Conclusions: We suggested that SEB could represent an agent that can significantly decrease smad2/3 expression in glioblastoma cells, leading to moderate TGF-β growth signaling and the reduction of tumor cell proliferation. © 2016, Ahvaz Jundishapur University of Medical Sciences

Electrical Transport Mechanisms in Conducting Particles‐Polymer Composites

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

STM study of YBa2Cu3O7-δ and Bi2Sr2CaCu2O8+° cleaved surfaces

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Position of interbody spacer in transforaminal lumbar interbody fusion: effect on 3-dimensional stability and sagittal lumbar contour

STUDY DESIGN: Biomechanical study. OBJECTIVE: To test 2 different intervertebral positions of a semilunar cage and their effects on 3-dimensional stability and segmental lordosis in a model of transforaminal lumbar interbody fusion (TLIF). SUMMARY OF BACKGROUND DATA: In his original TLIF description, Harms recommended decortication of endplates, followed by placement of mesh cages in the middle-posterior intervertebral third. Subsequent studies presented conflicting recommendations: anterior placement of the spacer-cage for better load-sharing versus placement on the stronger posterolateral endplate regions. METHODS: Six human lumbar spinal functional units were first tested intact. TLIF was performed using a semilunar poly-ether-ether-ketone cage randomly inserted in the anterior (TLIF-A) or posterior (TLIF-P) disc space. Pedicle screws and rods were added. Unconstrained pure moments in axial-torsion, lateral-bending (LB), and flexion-extension (FE) were applied under 0.05 Hz and +/-5 Nm sinusoidal waveform. Segmental motions were recorded. Range of motion (ROM) and neutral zone (NZ) were calculated. Pairwise comparisons were made using nonparametric Wilcoxon-matched pairs signed rank sum test with statistical significance set at P0.05). Delta-ROM between TLIF-A and TLIF-P was not significant (P>0.05). TLIF-A and TLIF-P significantly decreased NZ in LB (P0.05). Segmental lordosis of TLIF-A and TLIF-P on C-arm views showed angle differences within the range of measurement error of Cobb angles. CONCLUSIONS: Difference in ROM and NZ between anterior (TLIF-A) or posterior (TLIF-P) positions was not statistically significant. Similarly, both positions did not influence segmental lordosis

Biomechanical comparison of anterior lumbar interbody fusion and transforaminal lumbar interbody fusion

STUDY DESIGN: An in vitro biomechanical comparison of 2 fusion techniques, anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF), on cadaveric human spines. OBJECTIVE: To compare the immediate construct stability, in terms of range of motion (ROM) and neutral zone, of ALIF, including 2 separate approaches, and TLIF procedures with posterior titanium rod fixation. SUMMARY OF BACKGROUND DATA: Both ALIF and TLIF have been used to treat chronic low back pain and instability. In many cases, the choice between these 2 techniques is based only on personal preference. No biomechanical performance comparison between these 2 fusion techniques is available to assist surgical decision. METHODS: Twelve cadaveric lumbar motion segments were loaded sinusoidally at 0.05 Hz and 5 Nm in unconstrained axial rotation, lateral bending and flexion extension. Specimens were randomly divided into 2 groups with 6 in each group. One group was assigned for TLIF whereas the other group for ALIF. In the ALIF group, there were 3 steps. First, the lateral ALIF procedure with the anterior longitudinal ligament (ALL) intact was performed. Afterwards, the ALL was cut without removing the ALIF cage. Finally, another appropriately sized ALIF cage was inserted anteriorly. Biomechanical tests were conducted after each step. RESULTS: In the ALIF group, the lateral ALIF and subsequent anterior ALIF reduced segmental motion significantly (P=0.03) under all loading conditions. Removing the ALL increased ROM by 59% and 142% in axial rotation and flexion extension, respectively (P=0.03). The anterior ALIF approach was able to achieve similar biomechanical stability of the lateral approach in lateral bending and flexion extension (P>0.05) under all loading conditions. The TLIF procedure significantly reduced the range of motion compared with the intact state (P=0.03). However, no statistical difference was detected between the TLIF group and the ALIF group (P>0.05). CONCLUSIONS: Both ALIF and TLIF procedures combined with posterior instrumentation significantly improved construct stability of intact spinal motion segments. However, there was no statistical difference between these 2 fusion techniques. The 2 ALIF approaches (lateral and anterior) also had similar construct stability even though anterior longitudinal ligament severing significantly reduced stability

Negative pressure wound therapy (NPWT) for spinal wounds: a systematic review

Background context The management of postoperative spinal wound complication remains a challenge, with surgical site infection (SSI) incidence rates ranging from 0.4% to 20% after spinal surgery. Negative pressure wound therapy (NPWT) has been highlighted as an intervention that may stimulate healing and prevent SSI. However, the wound healing mechanism by NPWT and its effectiveness in spinal wounds still remain unclear. Purpose To systematically search, critically appraise, and summarize randomized controlled trials (RCTs) and non-RCTs assessing the effectiveness of NPWT in patients with a spinal wound. Study design Systematic review. Methods A systematic review based on search strategies recommended by the Cochrane Back and Wounds Review Groups was undertaken using Cochrane Library, MEDLINE, EMBASE, and CINAHL databases. Any publications between 1950 and 2011 were included. Funding to undertake the review was received from the University of Huddersfield Collaborative Venture Fund ($4,820) and KCI Medical ($4,820). Results Ten retrospective studies and four case studies of patients with spinal wound complication were included in this systematic review. No RCTs were found. Only one study described more than 50 patients. Generally, a pressure of −125 mm Hg was used in adults. Duration of NPWT in situ ranged from 3 to 186 days. Wound healing was assessed every 2 to 3 days and generally completed between 7 days and 16 months. Negative pressure wound therapy is contraindicated in the presence of active cerebrospinal fluid leak, metastatic or neoplastic disease in the wound or in patients with an allergy to the NPWT dressing and in those with a bleeding diathesis. Conclusions Published reports are limited to small retrospective and case studies, with no reports of NPWT being used as a prophylactic treatment. Larger prospective RCTs of NPWT are needed to support the current evidence that it is effective in treating spinal wound complications. In addition, future studies should investigate its use as a prophylactic treatment to prevent infection and report data relating to safety and health economics