In Vitro Parallel Evaluation of Antibacterial Activity and Cytotoxicity of Commercially Available Silver-Containing Wound Dressings.

PURPOSE: This study evaluated the in vitro antibacterial activity and cytotoxicity of various commercially available silver-containing dressings (Ag dressing). METHODS: Biohesive Ag (hydrocolloid, silver sulfadiazine), Aquacel® Ag (nonwoven fabric, ionic silver [Ag]), Algisite™ Ag (nonwoven fabric, Ag), Mepilex® Ag (foam, silver sulfate), and PolyMem® Ag (foam, nanocrystalline silver) were tested for characteristics of Ag release, antibacterial activity, and cytotoxicity. The release of Ag was investigated in cell culture medium at immersion periods of 6, 24, and 48 hours. The antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa were accessed by a disc diffusion test. The cytotoxicity was evaluated using V79 cells, by an extraction method. RESULTS: The cytotoxicity was not a monotonic function of the antibacterial activity among the Ag dressings and could not be simply explained by Ag-release properties. Biohesive Ag was regarded as a slow-release Ag dressing, showing the lowest cytotoxicity, while the antibacterial activity was classified as "strong" or "significant" against the two species of bacteria. Aquacel Ag and Algisite Ag showed higher antibacterial activity and cytotoxic effects, which were supported by the higher Ag release. Mepilex Ag showed the highest release of Ag, and the cytotoxicity was the highest among the Ag dressings. However, the antibacterial activity was classified as "significant" or "no activity" for P. aeruginosa and S. aureus, respectively. PolyMem Ag showed the lowest Ag release, and the antibacterial activity classified as "significant" or "no activity" for S. aureus and P. aeruginosa, respectively, whereas the cytotoxicity was similar to those of Aquacel Ag and Algisite Ag. CONCLUSION: The efficacy and adverse effects of the Ag dressings revealed differences that should be considered by clinicians during wound management.

Comparison of postural changes and muscle fatigue between two types of lumbar support: a prospective longitudinal study.

BACKGROUND: Lumbar supports are used in the management of low back pain (LBP). Although various types of lumbar supports are available, insufficient evidence exists regarding their effectiveness. The aim of this study was to investigate the effect of two types of lumbar support on postural change and muscle fatigue in a prospective longitudinal study. METHODS: A total of 144 subjects (9 men and 135 women) with LBP were enrolled in this study. Subjects were divided into 2 groups: a conventional lumbosacral support (LS) group and a wear-type support (SW) group. They filled in questionnaires that included the Short Form 36-Item Health Survey (SF-36), the Roland-Morris Disability Questionnaire (RDQ), and a questionnaire that evaluated the severity of LBP at baseline, 1, 2, and 3 months. The first 40 enrolled subjects were investigated for muscle fatigue and walking efficacy during a gait-loading test, and posture at baseline, 1 month, and 3 months. RESULTS: The intensity of LBP and the number of days with LBP significantly decreased over time in both groups. The decrease was similar in both groups at each time point. Wearing either support for 3 months did not induce erector spinae muscle fatigue. Furthermore, walking efficacy improved but spinal alignment was not affected by either support. Subjects in the SW group reported that the support was comfortable to wear for long periods, while subjects in the LS group mentioned that the LS relieved LBP by tightly supporting the lower back. CONCLUSION: Both types of support reduced mild LBP and improved walking efficiency without causing muscle fatigue.

Effectiveness of three types of lumbar orthosis for restricting extension motion.

Spinal orthoses are implemented to restrict lumbar motion. Several studies have compared the effectiveness of various types of lumbar orthoses on restricting motion, but none have compared the effect of different back supports on restricting extension. This study sought to evaluate the effectiveness of three types of lumbar orthosis in regard to their ability to restrict motion during extension. Range of motion was quantified using the Spinal Mouse system to measure flexion and extension, and the load distribution of the back support was measured using a pressure sensor. Ten subjects (8 men, 2 women) were assessed under the following five experimental conditions: custom-made stay (CMS), aluminum stay (AS), plastic stay (PS), corset only, and no brace. None of the stays changed the flexion angle, and none of the supports prevented flexion bending. The mean extension angle after immobilization with the CMS, AS, PS, corset only, and no brace was 27.5° ± 8.5°, 33.4° ± 11.0°, 34.3° ± 9.4°, 37.8° ± 10.7°, and 42.6° ± 10.5°, respectively. The load in the CMS was concentrated at the vertical ends of the stay, with a mean load of 11.5 ± 2.4 N at the top and 8.9 ± 2.4 N at the bottom. The loads at the top and bottom of the support were 7.2 ± 4.3 and 5.3 ± 3.1 N with the AS and 5.8 ± 2.3 and 4.4 ± 1.7 N with the PS, respectively. All supports allowed similar flexion motion. Although the CMS, AS, and PS all restricted extension compared with no brace, the CMS was the most effective for restricting trunk extension motion.

Acute effect of brisk walking with graduated compression stockings on vascular endothelial function and oxidative stress.

The purpose of this study was to investigate the acute effect of brisk walking with and without graduated compression stockings (GCSs) on vascular endothelial function and oxidative stress. Ten young healthy subjects walked briskly for 30 min with (GCS trial) and without (CON trial) GCSs in a randomized crossover trial. Brachial artery flow-mediated dilation (FMD) was measured as the per cent rise in the peak diameter from the baseline value at prior occlusion at each FMD measurement using B-mode ultrasonography before and 30 min after walking in the two trials. Derivatives of reactive oxygen metabolites (d-ROM), as an index of products of reactive oxygen species, and biological anti-oxidant potential (BAP), as an index of anti-oxidant potential, were also measured using a free radical elective evaluator before and 30 min after walking in both trials. FMD significantly decreased after brisk walking in both trials (P<0·05). However, FMD after brisk walking in the GCS trial was significantly higher than that in the CON trial (P<0·05). The d-ROM did not change before and after both trials, whereas the BAP significantly increased after walking in the GCS trial (P<0·05). These findings demonstrate that brisk walking while wearing GCSs suppresses the decrease in FMD and increases BAP.

The effect of a hydrocolloid dressing containing ceramide-2 on split-thickness wounds in a laser-induced erosion model.

OBJECTIVE: Lower levels of ceramides in the stratum corneum are considered to be an etiologic factor in the dry and barrier-disrupted skin of patients with atopic dermatitis, psoriasis vulgaris, and xeroderma pigmentosum. Topical ceramides therapy has currently been used to improve skin barrier function. However, little is known about the effect of topical ceramides on wound healing. This study investigated the effect of ceramide-2 on wound healing using a diabetic mouse model. DESIGN: Using a CO(2) laser to create standard erosions on the dorsal skin of mice, the authors developed a reproducible model of split-thickness wounds. Two wounds were placed on the back symmetrically across the spine of mice. The left-side wounds were covered with the hydrocolloid dressing containing 0.3% ceramide-2, and those on the right were covered with the control hydrocolloid dressing containing no ceramides. MAIN RESULTS: Seven days after the irradiation, controls showed a transepidermal water loss (TEWL) of 66.58 g/m(2)h on average, which was significantly higher than the mean TEWL of the ceramide-treated wounds, 46.22 g/m(2)h (P < .05, Student t test). Histological assessment also revealed ceramide-2 improved recovery of the erosion morphologically. CONCLUSION: The authors' findings suggest for the first time the possibility of the novel application of ceramide as a therapeutic agent for skin erosion.

Three-dimensional motion study of femur, tibia, and patella at the knee joint from bi-plane fluoroscopy and CT images.

In diagnosis and treatment of knee joint diseases, it is effective to study the three-dimensional (3D) motion of the patient's knee joint involving the femur, tibia, and patella. A 2D/3D registration method with use of fluoroscopy and CT images is promising for this purpose. However, there is no report showing whether the dynamic 3D motion of the patella can be obtained. In this study, we tried to examine dynamic 3D motion of the knee joint which included the patella. First, in order to investigate the accuracy of the position estimation, we conducted an experiment on a pig knee joint which had several fiducial markers placed on it, and we found that errors in the estimation of rotation and translation were less than 1 mm and 1 deg. We then carried out an image-acquisition experiment with healthy knee joints of three volunteers and confirmed that 3D motions of the femur, tibia, and patella were successfully obtained for all cases.