Comparative preclinical assessment of the use of dehydrated human amnion/chorion membrane to repair perforated sinus membranes

PURPOSE: The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits. METHODS: Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted. RESULTS: The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups. CONCLUSIONS: dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

Rates for Handwashing Adherence Before and After Nursing Contact in Intensive Care Units / 기본간호학회지

PURPOSE: The purpose of this study was to assess rates for handwashing adherence before and after nursing contact in intensive care units (ICU). METHODS: The participants included 90 nurses working in intensive care units of an 800-bed university-affiliated hospital in Gyeonggi Province and 2000-bed university-affiliated hospital in Seoul. Time for handwashing was calculated using the average number of handwashings during an 8-hour day shift. Nursing contact was based on indications as defined by the Centers for Disease Control and Prevention (CDC, 2002). Data were analyzed using frequency, percent, t-test and chi2-test. RESULTS: During an 8-hour day shift, the average number of times that hands were washed was 25.0. The rates were significantly lower before the nursing contact than after the nursing contact when it involved sectioning, observation or contact with a wound, cleaning enteric feeding bag, physical exam, use of gloves, or contact with contaminants. CONCLUSIONS: The results indicate that as handwashing rates were significantly lower before nursing contacts than after nursing contacts, there is need to develop strategies to address this deficiency in handwashing.

The biological effect of cyanoacrylate-combined calcium phosphate in rabbit calvarial defects

PURPOSE: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. METHODS: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). RESULTS: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. CONCLUSIONS: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.