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Day: January 11, 2017

mTOR pathway protein immunoexpression as a prognostic factor for survival in head and neck cancer patients: a systematic review and meta-analysis.

By wp_zaman

mTOR pathway protein immunoexpression as a prognostic factor for survival in head and neck cancer patients: a systematic review and meta-analysis.

J Oral Pathol Med. 2015 Dec 12;

Authors: Marques AE, Elias ST, Porporatti AL, Castilho RM, Squarize CH, De Luca Canto G, Guerra EN

Abstract
BACKGROUND: Several mTOR pathway proteins are involved in the regulation of cellular anabolism, growth, proliferation, and survival. Activated proteins in the mTOR pathway are deregulated in multiple types of cancers and could influence prognosis. However, it is unclear whether deregulation of mTOR pathway proteins serves a prognostic role in patients with head and neck cancer (HNC). Furthermore, proteins in the mTOR pathway may be important targets for anticancer therapy. The aim of this study was to summarize existing cohort studies to determine whether immunoexpression of mTOR pathway proteins are important prognostic factors for survival in patients with HNC.
MATERIALS AND METHODS: A systematic review was performed using the Cochrane, Lilacs, PubMed, ScienceDirect, Scopus, and Web of Science databases (up to 23 January 2015). A meta-analysis was conducted to measure the frequency of protein expression in head and neck cancer patient samples and the prognostic value of mTOR pathway proteins for overall survival (OS) and disease-free survival (DFS).
RESULTS: Twelve studies were included in our final analysis. The meta-analysis revealed that the frequency of overall expression of mTOR pathway proteins was 74.42% (CI: 63.3 to 84.0, P < 0.001, n = 2016 samples). The survival meta-analysis showed a pooled hazard ratio for OS and DFS of 1.44 (95% confidence interval [95% CI] 1.14-1.73) and 1.18 (95% CI 0.71-1.64), respectively.
CONCLUSION: This systematic review and meta-analysis support evidence that mTOR pathway proteins can be used as predictive markers for survival in patients with HNC because their expression was significantly associated with poor OS and short DFS.

PMID: 26661562 [PubMed – as supplied by publisher]

An investigation into PEEK-on-PEEK as a bearing surface candidate for cervical total disc replacement.

By wp_zaman
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An investigation into PEEK-on-PEEK as a bearing surface candidate for cervical total disc replacement.

Spine J. 2012 Jul;12(7):603-11

Authors: Kraft M, Koch DK, Bushelow M

Abstract
BACKGROUND CONTEXT: Total disc replacement (TDR) is a relatively new reconstructive non-fusion technology for the spine that aims to overcome some of the limitations of fusion technology. The first generation artificial discs were mainly based on well-known material combinations from total hip replacement.
PURPOSE: To evaluate the feasibility of PEEK-on-PEEK as a bearing surface material for use in cervical TDR.
STUDY DESIGN: In vitro biotribological study including the assessment of different parameters, including the influence of radial clearance, axial load, and angular motion on the wear performance of a PEEK-on-PEEK bearing.
METHODS: PEEK-on-PEEK bearing couples with ball-and-socket articulation were prepared using standard production methods. Two groups of bearing couples, one with large radial clearances and the other with small radial clearances, were manufactured for testing. Wear tests were performed using a servo-hydraulic wear simulator that allowed controlled motions to be applied in three axes corresponding to flexion-extension, lateral bending, and axial rotation. In addition, a dynamic axial compressive load was applied to simulate the weight of the head. All tests were performed at 37°C (±2°C) in bovine calf serum with a 30 g/l protein concentration. In the first test series, the influence of the radial clearance on the wear behavior was evaluated using the load and motion parameters for cervical TDR as defined in the ISO standard 18192-1. Subsequent tests were performed to check if surface degradation was influenced by thermal effects. Finally, in a third series of tests, the effect of load and motion profiles on wear performance was investigated by applying increased loads and corresponding motion parameters for lumbar TDR as defined in the ISO standard 18192-1.
RESULTS: The measured wear rates for a PEEK-on-PEEK bearing under cervical test conditions were considerably larger than those of similar testing using UHMWPE-on-CoCr and seemed to depend on initial radial clearances. The PEEK bearing surfaces exhibited severe surface degradation for large and small clearances, but the group with smaller clearances seemed to have less severe damage. Thermal effects were not found to play a role in the surface degradation, as the temperature near the bearing surface was measured and found to vary only a few degrees during testing. A change of the wear test parameters to simulate lumbar loading resulted in a considerable wear rate reduction as well as in the preservation of the bearing surfaces.
CONCLUSIONS: It was found that a cervical TDR using a PEEK-on-PEEK bearing may be subjected to severe long-term degradation of the bearing surfaces. In this study, the use of PEEK as an articulation material for cervical TDR was found to be sensitive to loading conditions as well as to the initial clearance of the bearing surfaces. Despite the excellent properties of PEEK as an implant material, its use for articulating surfaces for cervical TDR must be critically reviewed.

PMID: 22964013 [PubMed – indexed for MEDLINE]

A Clinical Comparison of Anterior Cervical Plates versus Stand-Alone Intervertebral Fusion Devices for Single-Level Anterior Cervical Discectomy and Fusion Procedures.

By Kamruz Zaman
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A Clinical Comparison of Anterior Cervical Plates versus Stand-Alone Intervertebral Fusion Devices for Single-Level Anterior Cervical Discectomy and Fusion Procedures.

World Neurosurg. 2016 Dec 22;:

Authors: Panchal RR, Kim KD, Eastlack R, Lopez J, Clavenna A, Brooks DM, Joshua G

Abstract
OBJECTIVE: To compare radiologic and clinical outcomes, including rates of dysphagia and dysphonia, using a no-profile stand-alone intervertebral spacer with integrated screw fixation versus an anterior cervical plate and spacer construct for single-level anterior cervical discectomy and fusion (ACDF) procedures.
METHODS: This multicenter, randomized, prospective study included 54 patients with degenerative disc disease (DDD) requiring ACDF at a single level at C3-C7. Twenty-six patients underwent single-level ACDF with stand-alone spacers (SA), and 28 with plate fixation and spacers (PS). Analyses were based on comparison of perioperative outcomes, radiological and clinical metrics, and incidence of dysphagia and/or dysphonia.
RESULTS: Mean patient age was 48.8±10.1years (53.7% female). No significant differences were observed between groups in operative time (101.8±34.4min, 114.4±31.5min), estimated blood loss (44.8±76.5cc, 82.5±195.1cc), or length of hospital stay (1.2±0.6days, 1.3±0.6days). Mean visual analog scale (VAS) pain scores and Neck Disability Index (NDI) scores improved significantly from preoperative to last follow-up (10.8±2.6mo) in both groups (P<0.05). Mean Voice Handicap Index (VHI) and Eating Assessment Tool (EAT) scores improved significantly from discharge to last follow-up in both groups (P<0.05). From discharge to 6 months, the SA group consistently demonstrated greater improvement in VHI. Preoperative intervertebral disc and neuroforaminal heights increased significantly across treatment groups (P<0.01), and no cases required surgical revision at index or adjacent levels.
CONCLUSIONS: Anterior cervical discectomy and fusion with stand-alone spacers resulted in similar clinical and radiologic outcomes as compared with plate and spacers and may help minimize postoperative dysphonia.

PMID: 28017756 [PubMed – as supplied by publisher]

Decompressive L5 Transverse Processectomy for Bertolotti’s Syndrome: A Preliminary Study.

By wp_zaman

Related Articles Decompressive L5 Transverse Processectomy for Bertolotti’s Syndrome: A Preliminary Study. Pain Physician. 2017 09;20(6):E923-E932 Authors: Ju CI, Kim SW, Kim JG, Lee SM, Shin H, Lee HY Abstract BACKGROUND: Bertolotti’s syndrome is a spinal disorder characterized by abnormal enlargement of the transverse process of the most caudal lumbar vertebra. The L5 transverse process…

Official Positions for FRAX® Bone Mineral Density and FRAX® simplification from Joint Official Positions Development Conference of the International Society for Clinical Densitometry and International Osteoporosis Foundation on FRAX®.

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Official Positions for FRAX® Bone Mineral Density and FRAX® simplification from Joint Official Positions Development Conference of the International Society for Clinical Densitometry and International Osteoporosis Foundation on FRAX®. J Clin Densitom. 2011 Jul-Sep;14(3):226-36 Authors: Lewiecki EM, Compston JE, Miller PD, Adachi JD, Adams JE, Leslie WD, Kanis JA, Moayyeri A, Adler RA, Hans DB,…