Interpretation of the DermaLab Combo® pigmentation and vascularity measurements in burn scar assessment: an exploratory analysis.

BACKGROUND: The DermaLab Combo® measures pigmentation and vascularity of a burn scar more reliably than the modified Vancouver Scar Scale (mVSS). This study aims to examine how the DermaLab Combo® continuous measurements of pigmentation and vascularity of burns scars relate to the mVSS, a standard clinical scar assessment method; and secondly, to obtain evidence to support the concurrent validity of DermaLab Combo® measurements for pigmentation and vascularity. METHOD: Scar assessments were performed on an index burn scar of 100 subjects using two methods: the mVSS (two raters) and the DermaLab Combo® device (one rater). Using the DermaLab Combo®, measurements of pigmentation and vascularity for the index scar and an adjacent normal skin site were obtained. Indices were generated to represent the scar pigmentation (melanin index, MI%) and scar vascularity (erythema index, EI%) relative to the patient's matched normal skin. Exploratory univariate and bivariate analyses were conducted and the concordance of classification by mVSS score using DermaLab® cut-off values was assessed. RESULTS: For pigmentation, the results suggest a 80% classification concordance for the DermaLab Combo® MI% values into mVSS pigmentation categories (hypopigmentation, normal pigmentation and hyperpigmentation) using two predictors (MI% and EI%) and visually fitted discriminant axis cut-offs. Due to the high degree of overlap of EI% values between the vascularity categories, meaningful classification of EI% values using the mVSS was not possible. CONCLUSION: Quantifying percentage changes in melanin and erythema relative to matched normal skin improved understanding of the DermaLab Combo® pigmentation and vascularity measurements. The DermaLab Combo® pigmentation MI% values were able to be classified into pigmentation categories of the mVSS, and pigmentation classification concordance was further improved with consideration of the scar's DermaLab Combo® vascularity EI% values. The DermaLab Combo® is an objective tool; however, while the measurement provides continuous numerical data that may be useful for identifying change over time in clinical scar monitoring of pigmentation and vascularity, further work will be useful to understand the DermaLab Combo® measurements to optimise the interpretation of these data.

Reliability of scar assessments performed with an integrated skin testing device - the DermaLab Combo(®).

BACKGROUND: The DermaLab Combo(®) is a device with potential to make objective measurements of key scar components - pigmentation, vascularity, pliability and thickness. This study assessed the inter-rater and test-retest reliability of these measurements. METHOD: Three raters performed scar assessments on thirty patients with burn scars using the DermaLab Combo(®). Measurements of pigmentation, vascularity, pliability and thickness were made and intra-class correlation coefficients (ICC) were derived for inter-rater and test-retest reliability. RESULTS: Inter-rater reliability was found to be "excellent" in the 'best' and 'worst' areas of the index scar and normal skin for pigmentation (ICC: 0.94-0.98) and thickness (ICC: 0.86-0.96). Test-retest reliability was also "excellent" for pigmentation (ICC: 0.87-0.89) and thickness (ICC: 0.92-0.97) in all areas. Vascularity showed "good" to "excellent" inter-rater reliability (ICC: 0.66-0.84) in all areas however test-retest reliability was "low" (ICC: 0.29-0.42). Test-retest reliability was "excellent" for pliability (ICC: 0.76-0.91). Technical limitations were encountered making measurements in some scars for thickness, and in particular, pliability. CONCLUSION: The DermaLab Combo(®) measured pigmentation, thickness and pliability with "excellent" reliability. If future studies provide protocols to improve test-retest reliability of vascularity measurements and obtain pliability measurements more successfully, the DermaLab Combo(®) will be valuable device for scar assessment.

Age-related injury and compensation claim rates in heavy industry.

BACKGROUND: Although ageing workers face specific health and safety concerns, conflicting evidence exists regarding the effects of age on workplace injury rates and workers' compensation claims. AIMS: To examine injury and workers' compensation claim rates by age and injury type in an aluminium smelter over a 9-year period. METHODS: Routinely collected data for workplace injuries and workers' compensation claims were retrieved for the period from 1997 to 2005. RESULTS: The study included a total of 709 workers who experienced 2281 at-work injuries and submitted 446 claims. In 1997, 16% of employees were aged 50 or over; by 2005 that proportion had more than doubled to 35%. Injury and claim rates in all age groups did not change significantly during this period. Workers younger than 30 years of age had the highest injury rates, with differences most significant for injuries other than sprains and strains. Claim rates were not significantly different across age groups. CONCLUSIONS: These findings do not provide evidence to support the notion that older workers sustain more injuries and are more likely to claim compensation for their injuries. Our findings demonstrate that in this workplace, older workers were able to maintain their ability to work safely. This contrasts with the finding that younger workers had the highest injury and claim rates. While adapting to the needs of an ageing workforce, employers should not lose sight of the need to nurture a strong culture of working safely among their youngest workers.

A modified Vancouver Scar Scale linked with TBSA (mVSS-TBSA): Inter-rater reliability of an innovative burn scar assessment method.

BACKGROUND: Current scar assessment methods do not capture variation in scar outcome across the burn scar surface area. A new method (mVSS-TBSA) using a modified Vancouver Scar Scale (mVSS) linked with %TBSA was devised and inter-rater reliability was assessed. METHOD: Three raters performed scar assessments on thirty patients with burn scars using the mVSS-TBSA. Scoring on pigmentation, vascularity, pliability and height was undertaken for the 'best' and 'worst' areas of each scar. Raters allocated the total body surface area of the scar (%TBSA) to three mVSS categories (<5, 5-10, >10). Intra-class correlation coefficient (ICC) and weighted kappa statistic (kw) were used to assess inter-rater reliability. The data were also analysed for clinically relevant misclassifications between pairs of raters. RESULTS: Total mVSS scores showed 'fair to good' agreement (ICC 0.65-0.73) in the 'best' area of the scar while there was 'excellent' agreement in the 'worst' scar area (ICC 0.85-0.88). The kw of the individual mVSS components ranged from 0.44 to 0.84 and 0.02 to 0.86 for 'best' and 'worst' scar areas, respectively. Determination of scar %TBSA had 'excellent' reliability (ICC 0.91-0.96). Allocation of scar %TBSA to severity category <5 mVSS demonstrated 'good to excellent' reliability (ICC 0.63-0.80) and 'fair to good' reliability (ICC 0.42-0.74) for 5-10 mVSS category. However, misclassifications were observed for the total mVSS score in the 'worst' scar area and the allocation of scar %TBSA in the <5 mVSS category. CONCLUSION: Inter-rater reliability of mVSS scores depends on the severity of the scar area being assessed. The mVSS-TBSA method of allocation of scar %TBSA to two broad mVSS categories, namely <5 and ≥5 mVSS, has 'good to excellent' reliability. The mVSS-TBSA has demonstrated utility for both clinical and research purposes; however, there is potential to misclassify scar outcome in some cases.

Interaction of the hepatic receptor protein for 2,3,7,8-tetrachlorodibenzo-rho-dioxin with DNA.

2,3,7,8-Tetrachlorodibenzo-rho-dioxin (TCDD) binds to a specific, high-affinity, low-capacity protein in rat liver cytosol. The TCDD-receptor complex is a large molecule with a Stokes radius of 6.6 nm as determined by gel filtration on calibrated columns. The receptor complex sediments at 5.0 S on glycerol gradients. The calculated molecular weight from the physical parameters was 136 000 and the frictional ratio 1.79. The TCDD-receptor complex binds to DNA-cellulose without preceding heat activation or incubation at high ionic strength. The receptor must first bind TCDD before it can interact with DNA. The DNA-binding ability can be removed from the TCDD receptor by limited proteolysis with trypsin. This treatment does not affect the TCDD-binding site of the receptor. The proteolytic fragment of the TCDD-receptor complex containing the TCDD-binding site but not the ability to bind to DNA appears to be approximately the same size as the native receptor, as judged from chromatography of Sepharose CL-6B and glycerol gradient centrifugation.

Platinum metals magmatic sulfide ores.

Platinum-group elements (PGE) are mined predominantly from deposits that have formed by the segregation of molten iron-nickel-copper sulfides from silicate magmas. The absolute concentrations of PGE in sulfides from different deposits vary over a range of five orders of magnitude, whereas those of other chalcophile elements vary by factors of only 2 to 100. However, the relative proportions of the different PGE in a given deposit are systematically related to the nature of the parent magma. The absolute and relative concentrations of PGE in magmatic sulfides are explained in terms of the degree of partial melting of mantle peridotite required to produce the parent magma and the processes of batch equilibration and fractional segregation of sulfides. The Republic of South Africa and the U.S.S.R. together possess more than 97 percent of the world PGE reserves, but significant undeveloped resources occur in North America. The Stillwater complex in Montana is perhaps the most important example.

Ontogeny of the rat hepatic receptor for 2,3,7,8-tetrachlorodibenzo-p-dioxin and its endocrine indepence.

The ontogeny of the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) receptor was studied in Sprague-Dawley rats by quantitation of the receptor in liver cytosol using isoelectric focusing in polyacrylamide gel. No differences by sex in the receptor concentration were seen at any of the ages studied. Newborn, 21-day-old, and 42-day-old rats contained significantly more receptor in the liver cytosol than did 56-day-old rats. There was no significant difference in the receptor concentration in liver cytosol from 7-day-old rats compared to that from 56-day-old rats. The maximum receptor concentration was found in cytosol from 21-day-old rats [36.1 +/- 24.0 (S.D.) fmol/mg protein]. Adult rats (56 days old) contained the lowest concentration of receptor (13.3 +/- 6.3 fmol/mg protein). The level of TCDD receptor in liver cytosol from adult rats was not significantly changed by orchiectomy, ovariectomy, adrenalectomy, or hypophysectomy. The maximum for TCDD receptor concentration at puberty corresponds to the reported maximum for the induction of aryl hydrocarbon hydroxylase activity. However, no further conclusion can as yet be drawn concerning the regulation of the TCDD receptor.