Burns objective scar scale (BOSS): Validation of an objective measurement devices based burn scar scale panel.

AIMS: Hypertrophic scars in burn survivors are a major cause of morbidity but the development of evidence based treatments is hampered by the lack of objective measurements of these scars. The objective of our study is to investigate the most accurate parameters for objective scar assessment and to create a combination score to facilitate the use of a panel of objective scar measurement tools. METHODS: Three independent assessors evaluated fifty five scar sites on fifty five burn patients with both the subjective modified Vancouver Scar Scale (mVSS) and a panel of objective measurement tools including the DSM II Colormeter, Cutometer, Dermascan high frequency ultrasound. The sensitivity and specificity of the objective scar parameters in predicting a mVSS score of 6 or more using the Receiving Operator Characteristic Area under the curve (ROC AUC) was then calculated and the most accurate parameters were combined to create an objective global scar score. RESULTS: The ROC AUC values were found to be highest for the Dermascan scar thickness (0.897), dermal intensity and intensity ratio (0.914 and 0.919), Cutometer R0 value (0.942), and R0 ratio (0.944). For colour measurements, ratios of scar to normal skin performed better than the single parameters for both erythema and pigmentation measurements: DSM II Erythema ratio vs Erythema (0.885 vs 0.818), DSM II a* ratio vs a* (0.848 vs 0.741); DSM II Melanin ratio vs Melanin (0.854 vs 0.761), DSM II L* ratio vs L* (0.862 vs 0.767). Analysis of the ROC AUC with chi-square test values showed that the highest AUC (0.786) was obtained with the combination of the Cutometer R0, Dermascan scar thickness, intensity and their respective scar to normal skin ratios. A total score of 5 and above (out of 6 parameters) had the highest combined sensitivity (69.0%) and specificity (83.3%). CONCLUSION: The objective parameters for the DSM II Colormeter, Cutometer and Dermascan high frequency ultrasound were all found to have moderate to strong ROC AUC values and combination of the Cutometer R0 and Dermascan scar thickness and intensity values can be used to create an objective global scar scale that can accurately differentiate patients with hypertrophic burn scarring from non-hypertrophic scars or normal skin.

Investigating the intra- and inter-rater reliability of a panel of subjective and objective burn scar measurement tools.

BACKGROUND: Research into the treatment of hypertrophic burn scar is hampered by the variability and subjectivity of existing outcome measures. This study aims to measure the inter- and intra-rater reliability of a panel of subjective and objective burn scar measurement tools. METHODS: Three independent assessors evaluated 55 scar and normal skin sites using subjective (modified Vancouver Scar Scale [mVSS] & Patient and Observer Scar Assessment Scale [POSAS]) and objective tools. The intra-class correlation coefficient was utilised to measure reliability (acceptable when >0.70). Patient satisfaction with the different tools and scar parameter importance were assessed via questionnaires. RESULTS: The inter-rater reliabilities of the mVSS and POSAS were below the acceptable limit. For erythema and pigmentation, all of the Scanoskin and DSM II measures (except the b* value) had acceptable to excellent intra and inter-rater reliability. The Dermascan ultrasound (dermal thickness, intensity) had excellent intra- and inter-rater reliability (>0.90). The Cutometer R0 (firmness) had acceptable reliability but not R2 (gross elasticity). All objective measurement tools had good overall satisfaction scores. Patients rated scar related pain and itch as more important compared to appearance although this finding was not sustained when corrected for multiple comparisons. CONCLUSION: The objective scar measures demonstrated acceptable to excellent intra- and inter-rater reliability and performed better than the subjective scar scales.

A gellan-based fluid gel carrier to enhance topical spray delivery.

Autologous cell transplantation was introduced to clinical practice nearly four decades ago to enhance burn wound re-epithelialisation. Autologous cultured or uncultured cells are often delivered to the surface in saline-like suspensions. This delivery method is limited because droplets of the sprayed suspension form upon deposition and run across the wound bed, leading to uneven coverage and cell loss. One way to circumvent this problem would be to use a gel-based material to enhance surface retention. Fibrin systems have been explored as co-delivery system with keratinocytes or as adjunct to 'seal' the cells following spray delivery, but the high costs and need for autologous blood has impeded its widespread use. Aside from fibrin gel, which can exhibit variable properties, it has not been possible to develop a gel-based carrier that solidifies on the skin surface. This is because it is challenging to develop a material that is sprayable but gels on contact with the skin surface. The manuscript reports the use of an engineered carrier device to deliver cells via spraying, to enhance retention upon a wound. The device involves shear-structuring of a gelling biopolymer, gellan, during the gelation process; forming a yield-stress fluid with shear-sensitive behaviours, known as a fluid gel. In this study, a formulation of gellan gum fluid gels are reported, formed with from 0.75 or 0.9% (w/v) polymer and varying the salt concentrations. The rheological properties and the propensity of the material to wet a surface were determined for polymer modified and non-polymer modified cell suspensions. The gellan fluid gels had a significantly higher viscosity and contact angle when compared to the non-polymer carrier. Viability of cells was not impeded by encapsulation in the gellan fluid gel or spraying. The shear thinning property of the material enabled it to be applied using an airbrush and spray angle, distance and air pressure were optimised for coverage and viability. STATEMENT OF SIGNIFICANCE: Spray delivery of skin cells has successfully translated to clinical practice. However, it has not yet been widely accepted due to limited retention and disputable cell viability in the wound. Here, we report a method for delivering cells onto wound surfaces using a gellan-based shear-thinning gel system. The viscoelastic properties allow the material to liquefy upon spraying and restructure rapidly on the surface. Our results demonstrate reduced run-off from the surface compared to currently used low-viscosity cell carriers. Moreover, encapsulated cells remain viable throughout the process. Although this paper studies the encapsulation of one cell type, a similar approach could potentially be adopted for other cell types. Our data supports further studies to confirm these results in in vivo models.

Human Y-chromosomal STR types in north Thailand.

A north Thai Y-haplotype database consisting of the loci DYS19, DXYS156-Y, DYS390, DYS391, DYS392, DYS393, and the four subsegments of DYS389 is presented. We observed 44 Y-types in 50 unrelated Thais, and the haplotype diversity was calculated to be 97.36%. No Y-types were shared with a sample of 55 Japanese, but 3 matches were found in a sample of 61 Han Chinese, and there was one Thai-German match in a larger west German sample (n = 179).

Microsatellite profiles reveal an unexpected genetic relationship between Asian populations.

Allelic frequencies for up to five short tandem repeat systems (HumTH01. HumVWA, HumF13B, HumCD4, HumD2111) were analyzed in seven population samples from Asia using the polymerase chain reaction and gel electrophoresis. No deviations from Hardy-Weinberg equilibrium were observed. Two new alleles of the CD4 and TH01 loci were detected, and sequenced and their molecular structure is presented. A phylogenetic tree based on Thai, Han Chinese (from the northeast of China), Japanese, German and Ovambo allelic frequencies was constructed and demonstrates the close relationship of the Asian populations. Additionally, allelic frequency data for the VWA and TH01 systems were determined for the south Chinese minorities Bai, Dai and Qiang and for Koreans and compared with the above data. The Bai and Dai populations were clear outliers of the cluster of all other Asians, indicating an unexpected pattern of genetic heterogeneity of the Chinese nation. Two clusters of Asian populations could be established: the Koreans and Japanese together with the Han and Qiang Chinese, and, forming a separate cluster, the Bai and Dai populations.

Analysis of the short tandem repeat systems HumVWA and HumF13B in a population sample from northern Thailand.

Two STR systems (HumVWA, HumF13B) were analysed in a northern Thailand population sample using PCR and gel electrophoresis. No deviations from Hardy-Weinberg equilibrium were observed. A rare VWA allele was detected, sequenced and the molecular structure is presented. Interpopulation comparisons revealed that the Thai allele frequencies were most similar to data from other Asian populations.

Postoperative monitoring of low molecular weight heparin prophylaxis in high-risk patients.

The alterations of the laboratory assays described for heparin monitoring in low molecular weight and unfractionated heparin prophylaxis groups did not correlate with the clinical outcome. Current laboratory techniques failed to detect an increased need for a higher dose of unfractionated or low molecular weight heparin to prevent DVT in these high-risk patients. The parameters commonly associated with thrombosis, that is, decreases in protein C and AT III were correlated with an increased incidence of DVT, but there was no difference in the assay values between the low molecular weight heparin and unfractionated heparin groups. Fibrinolysis activation is known to be associated with surgery; however, our data suggest an additional activation due to low molecular weight heparin compared with the unfractionated heparin group. Most interestingly, elevated PAI levels appear to correlate with thrombosis.