Comparing the TiOblast and Osseospeed surfaces. Histomorphometric and histological analysis in humans

The aim of the present study was to compare two implant surfaces, the TiOblast (Astra Tech) surface, manufactured by blasting the surface and already present in literature and the Osseospeed (Astra Tech) surface, manufactured by blasting and treating the surface with fluoride ions and recently launched onto the market with the modified surfaces of the latest generation. This study is part of a more extensive research project whose protocol required the insertion of 10 couples of implants; thus in the present discussion partial data are being taken into consideration, with an eye at collecting more data in the future, regarding both microscopy and histomorphometric histological analysis on 5 couples of implants. The purpose of the study is to investigate how the modified surfaces of the latest generation can guarantee a greater osseointegration both from a qualitative and quantitative level compared to the surfaces presently used and that they may represent the first example of "bioactivity", that is, an active interaction with the processes of new bone formation and tissue healing

The DICE calibration project: design, characterization, and first results

We describe the design, operation, and first results of a photometric calibration project, called DICE (Direct Illumination Calibration Experiment), aiming at achieving precise instrumental calibration of optical telescopes. The heart of DICE is an illumination device composed of 24 narrow-spectrum, high-intensity, light-emitting diodes (LED) chosen to cover the ultraviolet-to-near-infrared spectral range. It implements a point-like source placed at a finite distance from the telescope entrance pupil, yielding a flat field illumination that covers the entire field of view of the imager. The purpose of this system is to perform a lightweight routine monitoring of the imager passbands with a precision better than 5 per-mil on the relative passband normalisations and about 3{\AA} on the filter cutoff positions. The light source is calibrated on a spectrophotometric bench. As our fundamental metrology standard, we use a photodiode calibrated at NIST. The radiant intensity of each beam is mapped, and spectra are measured for each LED. All measurements are conducted at temperatures ranging from 0{\deg}C to 25{\deg}C in order to study the temperature dependence of the system. The photometric and spectroscopic measurements are combined into a model that predicts the spectral intensity of the source as a function of temperature. We find that the calibration beams are stable at the $10^{-4}$ level -- after taking the slight temperature dependence of the LED emission properties into account. We show that the spectral intensity of the source can be characterised with a precision of 3{\AA} in wavelength. In flux, we reach an accuracy of about 0.2-0.5% depending on how we understand the off-diagonal terms of the error budget affecting the calibration of the NIST photodiode. With a routine 60-mn calibration program, the apparatus is able to constrain the passbands at the targeted precision levels.Comment: 25 pages, 27 figures, accepted for publication in A&

Angiogenesis modifications related with cetuximab plus irinotecan as anticancer treatment in advanced colorectal cancer patients.

Introduction: Angiogenesis has been correlated with increased invasion and metastases in a variety of human neoplasms. Inadequate inhibition of the growth of tumor microvessels by anticancer agents may result in treatment failure, rated clinically as progressive or stable disease. We designed this trial to investigate the modification of the vascular endothelial growth factor (VEGF) and interferon-c (IFN-c) in advanced colorectal cancer patients during treatment with a weekly combination of cetuximab plus irinotecan. Materials and methods: Forty-five metastatic colorectal cancer patients were prospectively evaluated for circulating levels of VEGF and IFN-c during the treatment with cetuximab (initial dose of 400 mg/m2 , followed by weekly infusions of 250 mg/m2 ) plus weekly irinotecan (90 mg/m2 ). The circulating levels of the cytokines were assessed at the following time points: just before and at 1, 21, 50 and 92 days after the start of cetuximab plus irinotecan treatment. Results: Basal serum VEGF median levels were significantly decreased just at the first day (after the first treatment infusion (P = 0.016). The VEGF persisted at the following time points reaching the highest statistical significance 92 days after the first infusion (P < 0.0001). On the contrary, IFN-c values showed a statistical significant increase one day after the first infusion (P < 0.0001). This effect persisted 21 days after the treatment start (P = 0.001), but was no more evident at the following time points. Moreover, a linear regression model with variance analysis showed a significant negative correlation between VEGF and IFN-c values 1, 21 and 50 days after the treatment beginning (P = 0.002, 0.001 and 0.047, respectively). Conclusions: This study suggests that a cetuximab may induce a modulation of VEGF circulating levels. The reduction of VEGF serum levels is a sudden and long lasting phenomenon. Moreover, in our study we identified a IFN-c increase, even if the specific role of this behavior remains to be investigated