Human papillomavirus related head and neck cancer survival: a systematic review and meta-analysis

Human Papillomavirus (HPV) related oropharyngeal squamous cell carcinomas (OPSCCs) are reported to have improved prognosis and survival in comparison to other head and neck squamous cell cancers (HNSCCs). This systematic review and meta-analysis examines survival differences in HPV-positive HNSCC and OPSCC subtypes including tonsillar carcinoma in studies not previously investigated. Four electronic databases were searched from their inception till April 2011. A random effects meta-analysis was used to pool study estimates evaluating disease-specific (death from HNSCC), overall (all-cause mortality), progression-free and disease-free (recurrence free) survival outcomes in HPV-positive vs. HPV-negative HNSCCs. All statistical tests were two-sided. Forty-two studies were included. Patients with HPV-positive HNSCC had a 54% better overall survival compared to HPV-negative patients HR 0.46 (95% CI 0.37-0.57); the pooled HR for tonsillar cancer and OPSCC was 0.50 (95% CI 0.33-0.77) and HR 0.47 (95% CI 0.35-0.62) respectively. The pooled HR for disease specific survival was 0.28 (95% CI 0.19-0.40); similar effect sizes were found irrespective of the adjustment for confounders, HPV detection methods or study location. Both progression-free survival and disease-free survival were significantly improved in HPV-positive HNSCCs. HPV-positive HNSCCs and OPSCCs patients have a significantly lower disease specific mortality and are less likely to experience progression or recurrence of their cancer than HPV-negative patients; findings which have connotations for treatment selection in these patients.

SU-E-I-67: Multi-Shot RESOLVE Compared to Single-Shot EPI Diffusion- Weighted MR Imaging Acquisition Scheme

PURPOSE

The purpose of this project was to configure the parameters for optimal comparison of image quality differences between the prototype imaging technique, read-out-segmented EPI multi-shot (RESOLVE) and the clinically used single-shot EPI (SS-EPI) MRI sequence for Diffusion Weighted Imaging (DWI) in a saline phantom, followed by a normal rat brain.

METHODS

Saline phantom (4.2 × 4.2 cm² ) and a rat brain were imaged on the 1.5T ESPREE (Siemens, Germany) MRI magnet using a wrist coil. Both the SS-EPI and RESOLVE DWI were optimized with equal imaging parameters such as slice thickness/slice gap = 3.0/0 mm, field of view = 210 mm, phase resolution = 100%, and diffusion b values = 0, 600 s/mm² while other parameters were given similar settings such as the base resolution, which had to be interpolated for the SS-EPI to 96i to match the RESOLVE as it was unable to be set at 192. Image quality was compared in terms of signal intensity, distortion, % ghosting and Apparent Diffusion Co-efficient (ADC) measurements from each sequence.

RESULTS

A marked enhancement of overall image quality with superior detail was observed in each of the scans from the RESOLVE sequence when compared to the SS-EPI. Comparing the efficiency of both sequences in terms of image quality, RESOLVE demonstrated a better stable image with minimal distortion and ghosting. The phantom dimensions obtained from RESOLVE images matched the actual dimensions perfectly. RESOLVE images had signal intensities significantly higher than (2.4×) the SS-EPI images (p=0.0008) and ∼0.6 % times less ghosting compared to SS-EPI (p=0.82) which also exhibited distortion with reduced phantom dimensions (4.05 × 3.28 cm) from original. The ADC values computed were almost identical to be (p=0.32) from SS-EPI (2.21mm² /sec) and RESOLVE (2.19mm² /sec).

CONCLUSIONS

The RESOLVE sequence has significantly superior image quality compared to SS-EPI at 1.5 T with reasonable scan times. DWI with RESLOVE acquisition scheme can be highly beneficial in obtaining distortion free images in routine clinical studies to characterize tumors and other pathological mechanisms with much greater detail than the current clinically used SS-EPI.

A study of brain and serum brain-derived neurotrophic factor protein in Wistar and Wistar-Kyoto rat strains after electroconvulsive stimulus

BACKGROUND

Serum brain-derived neurotrophic factor (BDNF) protein has been related to depression and less consistently to its treatments in human studies. However, animal studies have failed to demonstrate a clear link between BDNF protein in serum and brain tissue.

METHODS

Serum and brain tissue levels of BDNF protein were measured with ELISA in the Wistar-Kyoto (WKY) and Wistar strains at 1 and 7 days after 5 daily electroconvulsive stimulus sessions or sham treatments.

RESULTS

The WKY strain showed lower baseline serum BDNF protein relative to Wistar controls. After 5 electroconvulsive stimuli, BDNF protein density was significantly increased in hippocampus and cortical regions, but not in the cerebellum or in serum. A clear correlation between brain and serum BDNF was not observed in either strain or treatment group.

DISCUSSION

Despite lower baseline serum BDNF protein in the WKY strain, a lack of change in serum BDNF after electroconvulsive stimulus and a lack of correlation between brain and serum BDNF protein calls into question the relevance of serum BDNF as a measure of depression and treatment response.

Investigations into the molecular-level adhesion characteristics of hydroxyapatite-coated and anodized titanium surfaces using the molecular orbital approach

It has been established that the adhesion of cells on to the surfaces of orthopaedic implants depends on the ability of the surfaces to accommodate protein molecules. Hydroxyapatite coating and anodizing are the most common methods to make TiAl6V4 implants (Ti) more biocompatible. In this paper Spartan 02, a molecular dynamics software, is used to analyze and predict the bonding characteristics of Extra cellular matrix protein sequence arginine-glycine-aspartic acid (RGD) on a Hyrdoxyapatite (HA) coated Ti and an anodized Ti surface based on the property of its constituent atoms, their polarity (net electrostatic charge, Qr), the energies of the molecular orbital E_HOMO (energy of the highest occupied molecular orbital), and E_LUMO (energy of the lowest unoccupied molecular orbital). The results show favourable criterion for formation of bonding between the HOMO orbital of the HA coated and anodized surfaces and LUMO orbital of the glycine strand from the RGD unit. The mechanism of bonding of individual atoms to form primary calcium oxide compounds is likely only in the case of HA coated surfaces . The surface texture of the anodized Ti with inherent porosities appear more responsible for the adsorption of proteins on to them by mechanical interlocking than the formation of any intermediate calcium oxide compounds.