Lower temperature at the wound edge detected by thermography predicts undermining development in pressure ulcers: a pilot study.

Undermined pressure ulcers (PUs) are troublesome complications that are likely to delay wound healing. Early skin incision and debridement can prevent the deterioration of undermined PUs, thus it is necessary to identify devitalised tissue areas to determine the appropriate timing for such interventions. This retrospective cohort study evaluated whether a lower temperature at the wound edge than the wound bed and periwound skin, detected by thermography, can predict undermining development in PUs 1 week after the assessment. Twenty-two participants with category III, IV, or unstageable PUs who were examined by interdisciplinary PU team and were followed up for at least two consecutive weeks were analysed. We found 9/11 PUs without a lower temperature at the wound edge did not develop undermining development, whereas 8/11 PUs with the lower temperature did develop undermining. The relative risk of undermining development after 1 week in PUs with the lower temperature was 4·00 (95% confidence intervals: 1·08-14·7). The sensitivity, specificity, positive predictive value and negative predictive value were 0·80, 0·75, 0·73 and 0·81, respectively. A thermal imaging assessment focusing on a lower temperature pattern at the wound edge may provide sufficient information to predict undermining development.

Pseudomonas aeruginosa quorum-sensing signaling molecule N-3-oxododecanoyl homoserine lactone induces matrix metalloproteinase 9 expression via the AP1 pathway in rat fibroblasts.

Quorum sensing is a cell-to-cell communication mechanism, which is responsible for regulating a number of bacterial virulence factors and biofilm maturation and therefore plays an important role for establishing wound infection. Quorum-sensing signals may induce inflammation and predispose wounds to infection by Pseudomonas aeruginosa; however, the interaction has not been well investigated. We examined the effects of the P. aeruginosa las quorum-sensing signal, N-3-oxo-dodecanoyl homoserine lactone (3OC12-HSL), on matrix metalloproteinase (MMP) 9 expression in Rat-1 fibroblasts. 3OC12-HSL upregulated the expression of the MMP9 gene bearing an activator protein-1 (AP-1) binding site in the promoter region. We further investigated the mechanism underlying this effect. c-Fos gene expression increased rapidly after exposure to 3OC12-HSL, and nuclear translocation of c-Fos protein was observed; both effects were reduced by pretreatment with an AP-1 inhibitor. These results suggest that 3OC12-HSL can alter MMP9 gene expression in fibroblasts via the AP-1 signaling pathway.

Screening for tinea unguium by thermography in older adults with subungual hyperkeratosis.

AIM: The purpose of the present study was to assess the difference in foot temperature between tinea unguium-positive older adults with subungual hyperkeratosis and tinea unguium-negative older adults with subungual hyperkeratosis to develop a temperature-based screening method for tinea unguium. METHODS: The present cross-sectional, observational study investigated 51 residents with subungual hyperkeratosis in two facilities covered by long-term care insurance between October 2011 and December 2011. One dermatologist recorded the clinical signs of abnormal toenails. Nail specimens were collected from all abnormal nails, and the presence of tinea unguium was confirmed when fungus was detected by direct microscopy. Foot temperature was measured by infrared thermography. A receiver operating characteristic curve was used to assess the ability to determine whether residents with subungual hyperkeratosis have tinea unguium and to determine the cut-off point. RESULTS: Among the people with subungual hyperkeratosis, the mean toe temperature in the tinea unguium-positive group (30.2 ± 2.6°C) was significantly lower than that in the tinea unguium-negative group (32.8 ± 3.2°C, P = 0.001). The area under the receiver operating characteristic curve was 0.74 (95% confidence interval 0.621-0.876), and the threshold temperature was set at 33.0°C, resulting in a sensitivity of 81.8% and specificity of 65.7%. CONCLUSION: Our study suggests that foot temperature can be used to screen for tinea unguium in people with subungual hyperkeratosis. This non-invasive and simple screening method would help clinicians to set priorities in terms of carrying out direct microscopy to diagnose tinea unguium in elderly residents in care facilities.

Biological responses of three-dimensional cultured fibroblasts by sustained compressive loading include apoptosis and survival activity.

Pressure ulcers are characterized by chronicity, which results in delayed wound healing due to pressure. Early intervention for preventing delayed healing due to pressure requires a prediction method. However, no study has reported the prediction of delayed healing due to pressure. Therefore, this study focused on biological response-based molecular markers for the establishment of an assessment technology to predict delayed healing due to pressure. We tested the hypothesis that sustained compressive loading applied to three dimensional cultured fibroblasts leads to upregulation of heat shock proteins (HSPs), CD44, hyaluronan synthase 2 (HAS2), and cyclooxygenase 2 (COX2) along with apoptosis via disruption of adhesion. First, sustained compressive loading was applied to fibroblast-seeded collagen sponges. Following this, collagen sponge samples and culture supernatants were collected for apoptosis and proliferation assays, gene expression analysis, immunocytochemistry, and quantification of secreted substances induced by upregulation of mRNA and protein level. Compared to the control, the compressed samples demonstrated that apoptosis was induced in a time- and load- dependent manner; vinculin and stress fiber were scarce; HSP90α, CD44, HAS2, and COX2 expression was upregulated; and the concentrations of HSP90α, hyaluronan (HA), and prostaglandin E2 (PGE2) were increased. In addition, the gene expression of antiapoptotic Bcl2 was significantly increased in the compressed samples compared to the control. These results suggest that compressive loading induces not only apoptosis but also survival activity. These observations support that HSP90α, HA, and, PGE2 could be potential molecular markers for prediction of delayed wound healing due to pressure.

The prevalence of skin eruptions and mycoses of the buttocks and feet in aged care facility residents: a cross-sectional study.

The prevalence of skin mycoses in the elderly remains unclear. The proportion of people with skin eruptions who are positive for mycoses using direct microscopy is not known. The purpose of this study is to identify the prevalence of skin eruptions and skin mycoses (e.g. candidiasis and tinea) in the buttocks and feet, which are common sites of skin mycoses in residents of long-term care facilities. This multi-site cross-sectional study used visual inspection and direct microscopy to diagnose the type of skin eruption. Subjects were residents of facilities covered by long-term care insurance schemes in Japan. Of the 171 residents enrolled in this study, 72.5% had a skin eruption. Only 4.8% of participants had tinea in the buttocks; 2.4% had buttock candidiasis. In those with a nail abnormality, 58.3% of residents had tinea unguium. For tinea pedis, residents who had any form of interdigital or plantar region skin eruption, 22.5% and 31.4% of residents were positive, respectively. The prevalence of observed skin mycoses was: buttock candidiasis 1.8%; buttock tinea 3.5%; tinea unguium 56.2%; interdigital tinea pedis 20.5%; and plantar tinea pedis 22.5%. The very low proportion of residents with mycoses in the buttocks suggests that anti-inflammatory agents, such as steroids, should be used as first choice. Our observation that not all residents with skin eruptions on the feet had tinea, should remind clinicians to perform direct microscopy before initiating antifungal treatments.

Hydrocellular foam dressing promotes wound healing along with increases in hyaluronan synthase 3 and PPARα gene expression in epidermis.

BACKGROUND: Hydrocellular foam dressing, modern wound dressing, induces moist wound environment and promotes wound healing: however, the regulatory mechanisms responsible for these effects are poorly understood. This study was aimed to reveal the effect of hydrocellular foam dressing on hyaluronan, which has been shown to have positive effects on wound healing, and examined its regulatory mechanisms in rat skin. METHODOLOGY/PRINCIPAL FINDINGS: We created two full-thickness wounds on the dorsolateral skin of rats. Each wound was covered with either a hydrocellular foam dressing or a film dressing and hyaluronan levels in the periwound skin was measured. We also investigated the mechanism by which the hydrocellular foam dressing regulates hyaluronan production by measuring the gene expression of hyaluronan synthase 3 (Has3), peroxisome proliferator-activated receptor α (PPARα), and CD44. Hydrocellular foam dressing promoted wound healing and upregulated hyaluronan synthesis, along with an increase in the mRNA levels of Has3, which plays a primary role in hyaluronan synthesis in epidermis. In addition, hydrocellular foam dressing enhanced the mRNA levels of PPARα, which upregulates Has3 gene expression, and the major hyaluronan receptor CD44. CONCLUSIONS/SIGNIFICANCE: These findings suggests that hydrocellular foam dressing may be beneficial for wound healing along with increases in hyaluronan synthase 3 and PPARα gene expression in epidermis. We believe that the present study would contribute to the elucidation of the mechanisms underlying the effects of hydrocellular foam dressing-induced moist environment on wound healing and practice evidence-based wound care.

Reliability and validity of the Chinese version of DESIGN-R, an assessment instrument for pressure ulcers .

Lack of a valid and reliable assessment instrument may have contributed to a lack of wound healing research in China. The DESIGN-R tool scores the severity of pressure ulcers (PUs) and monitors healing using the observable state assessment; it was developed by the Scientific Education Committee of the Japanese Society of Pressure Ulcers (JSPU) and tested for reliability and validity. A Chinese version of DESIGN-R was developed based on Brislin's model of translationand tested for validity and reliability. Using a purposive sampling method, 44 practicing registered nurses (RNs) and 11 physicians (MDs) were recruited from 52 departments of Nanfang Hospital, Guangdong, China. Based on their experience, they were classified as general medical staff (gMS) or experienced medical staff (eMS). All used the Chinese version of DESIGN-R to assess eight photographs of PUs and descriptors. In addition, eight eMS also used the Bates- Jensen Wound Assessment Tool (BWAT) to assess the same wounds. Inter-rater reliability was high (total ICC score = 0.960). ICC inflammation/infection scores were 0.530 and 0.759 for gMS and eMS, respectively; granulation ICC scores were 0.532 and 0.794 in gMS and eMS, respectively. The correlation coefficients between the BWAT and DESIGN-R tool were >0.80 for all eight raters. The results suggest the Chinese version of DESIGN-R is valid and reliable and may be a useful scoring tool for RNs and MDs to monitor PU status in daily clinical practice. Additional research is warranted, and clinical instruments for inflammation/infection and granulation assessment must be developed for gMS.

Wound blotting: a convenient biochemical assessment tool for protein components in exudate of chronic wounds.

Because wound exudate includes secreted proteins that affect wound healing, its biochemical analysis is useful for objective assessment of chronic wounds. Wound blotting allows for collection of fresh exudate by attaching a nitrocellulose membrane onto the wound surface. To determine its applicability for several analysis methods and its executability in clinical wound assessment, this study comprised an animal experiment and clinical case reports. In the animal experiment, full-thickness wounds were created on the dorsal skin of mice, and exudate samples were collected daily by a conventional method and by wound blotting. Extremely small but adequate volumes of exudate were collected by wound blotting for subsequent analysis in the animal experiments. Immunostaining showed the concentration and distribution of tumor necrosis factor (TNF) α. The activity of alkaline phosphatase was visualized by reaction with chemiluminescent substrate. The TNF distribution analysis indicated three different patterns: wound edge distribution, wound bed distribution, and a mostly negative pattern in both the animal and clinical studies, suggesting association between the TNF distribution pattern and wound healing. Our results indicate that wound blotting is a convenient method for biochemical analysis of exudate and a candidate tool with which to predict the healing/deterioration of chronic ulcers.