Page 31 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

Hyperoxia-driven microvascular changes
contrasted by a bright background. The MicroScan instrument is equipped with
a 5× objective lens system (onscreen magnification approximating 380×), which
in turn produce images captured by a charge-coupled device video camera
with a 640×480-pixel resolution (3 μm·pixel-1) resulting in a 0.94 mm×0.75 mm
imaged tissue segment. Prior to planning the experiments in this study, the 2 interior components and cable connecting systems of the MicroScan instrument
were carefully examined and tested by the same two experienced HB chamber electrical technicians to ascertain device safety for this investigation.
The MicroScan power supply is derived from an external DC power pack (12V/4500mAh). For this study a modified connecting system was prepared to accommodate only the MicroScan apparatus inside the HB chamber. The MicroScan and its DC power pack connecting cable system was split into two separate segments; two cables were separately assembled and equipped at each end with both a metal 6-pin (LEMO) male solder push-pull connector plug and at the other end with an Amphenol circular type 6-pin connector corresponding with the connecting panel connectors located both on the interior and exterior of the HB chamber. Outside the HB chamber, all measurements were stored on DVI tapes, recorded by a Sony DSR-11 DVCAMTM video recorder (Sony, Shinagawa-ku, Tokyo, Japan), and viewed on a 19-inch Samsung SyncMaster 932mv LCD monitor (Samsung, Seoul, South Korea) with a 1440×900-screen resolution.
All microcirculation data acquisitions were performed with the MicroScan mounted on top of a modified micromanipulator [Fig. 1A]. Prior to advancing the imaging probe towards the ROI, excess secretions and debris (e.g. saliva and food) were gently removed using a 5 cm×5 cm non-sterile gauze moistened with 0.9% sterile NaCl kept at 38oC. Microcirculation measurements free of pressure induced artifacts, bubbles, and excess saliva were obtained after carefully advancing, positioning, and maintaining the lens of the imaging probe, covered with a sterile disposable cap (Microscan Lens, MicroVision Medical, Amsterdam, The Netherlands), with gentle contact directly on the right sublingual mucosa (base of the tongue) adjacent to the frenulum linguae [Fig. 1B]. From this point forward, with ideal focus and contrast adjustments, the probe was maintained on the same ROI for the entire duration of the two-part experimental protocol, as measurements of 2-min each were recorded sequentially at all designated time points.
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