Studies of air, water, and ethanol vapor atmospheric pressure plasmas for antimicrobial applications.

The generation of air-based plasmas under atmospheric plasma conditions was studied to assess their antimicrobial efficacy against commonly found pathogenic bacteria. The mixture of initial gases supplied to the plasma was found to be critical for the formation of bactericidal actives. The optimal gas ratio for bactericidal effect was determined to be 99% nitrogen and 1% oxygen, which led to a 99.999% reduction of a pathogenic strain of Escherichia coli on stainless steel surfaces. The experimental substrate, soil load on the substrate, flow rate of the gases, and addition of ethanol vapor all were found to affect antimicrobial efficacy of studied plasmas. Optical emission spectroscopy was used to identify the species that were present in the plasma bulk phase for multiple concentrations of nitrogen and oxygen ratios. The collected spectra indicate a unique series of bands present in the ultraviolet region of the electromagnetic spectrum that can be attributed to nitric oxide species known to be highly antimicrobial. This intense spectral profile dramatically changes as the concentration of nitrogen decreases.

Posterior elbow coverage using whole and split flexor carpi ulnaris flaps: a cadaveric study.

PURPOSE: The purpose of this study is to evaluate the coverage patterns of whole and split flexor carpi ulnaris (FCU) pedicle muscle flaps for posterior elbow soft-tissue defects. METHODS: Seventeen fresh-frozen cadaveric upper extremities were used. The whole FCU was raised to the dominant vascular pedicle and transposed proximally over the olecranon. The widths of coverage at 2-cm distances about the posterior elbow were measured. Widths were also measured after making 3 longitudinal cuts in the fascia and after suturing the muscle to adjacent soft tissue under tension. The FCU was also split into its ulnar and humeral heads along the central tendon. The larger ulnar head was transposed and the widths again measured. Mid-forearm circumference, elbow circumference, and ulnar length were assessed for ability to predict flap width. RESULTS: The whole muscle under no tension provided an average of 2.7 cm width coverage at the tip of the olecranon process. Cutting the fascia provided approximately 15% additional width and suturing the muscle to the surrounding soft tissue an additional 25%, to approximately 4 cm. The isolated FCU ulnar head provided approximately 75% of the width of the entire muscle. Mid-forearm circumference was the most predictive of flap width, and divisors were generated that improved the accuracy of predicting the width for outlier specimens. The dominant pedicle was a consistent distance relative to the end of the central tendon and the olecranon tip. CONCLUSIONS: The whole and split FCU pedicle flaps provide predictable coverage for 2- to 4-cm posterior elbow soft-tissue defects. For especially large and small arms, the divisors improve accuracy in predicting flap width. Consistent locations of the olecranon tip and the end of the central tendon in relation to the dominant pedicle make them useful surgical landmarks.

House dust mites in the West Indies

The purpose of this study was to determine the role of the house dust mite, Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df), in allergic diseases on the island of St. Lucia. Dust samples were taken from living quarters of patients and hospital volunteers. The level of Df antigen in these living quarters was measured by RAST inhibition. All samples showed Df antigen within a large range of values. Prick tests were done to house dust mite and molds on 91 patients with suspected allergic disease with 63 (69 percent) reacting to at least one antigen. Of these, 56 (88.9 percent) reacted to one or both mites. House dust mite is a major allergen in St. Lucia. (AU)