Optimization of psoriasis assessment system based on patch images.

Psoriasis is a chronic inflammatory skin disease that occurs in various forms throughout the body and is associated with certain conditions such as heart disease, diabetes, and depression. The psoriasis area severity index (PASI) score, a tool used to evaluate the severity of psoriasis, is currently used in clinical trials and clinical research. The determination of severity is based on the subjective judgment of the clinician. Thus, the disease evaluation deviations are induced. Therefore, we propose optimal algorithms that can effectively segment the lesion area and classify the severity. In addition, a new dataset on psoriasis was built, including patch images of erythema and scaling. We performed psoriasis lesion segmentation and classified the disease severity. In addition, we evaluated the best-performing segmentation method and classifier and analyzed features that are highly related to the severity of psoriasis. In conclusion, we presented the optimal techniques for evaluating the severity of psoriasis. Our newly constructed dataset improved the generalization performance of psoriasis diagnosis and evaluation. It proposed an optimal system for specific evaluation indicators of the disease and a quantitative PASI scoring method. The proposed system can help to evaluate the severity of localized psoriasis more accurately.

Molecular Phenotyping Small (Asian) versus Large (Western) Plaque Psoriasis Shows Common Activation of IL-17 Pathway Genes but Different Regulatory Gene Sets.

Psoriasis is present in all racial groups, but in varying frequencies and severity. Considering that small plaque psoriasis is specific to the Asian population and severe psoriasis is more predominant in the Western population, we defined Asian small and intermediate plaque psoriasis as psoriasis subtypes and compared their molecular signatures with the classic subtype of Western large plaque psoriasis. Two different characteristics of psoriatic spreading-vertical growth and radial expansion-were contrasted between subtypes, and genomic data were correlated to histologic and clinical measurements. Compared with Western large plaque psoriasis, Asian small plaque psoriasis revealed limited psoriasis spreading, but IL-17A and IL-17-regulated proinflammatory cytokines were highly expressed. Paradoxically, IL-17A and IL-17-regulated proinflammatory cytokines were lower in Western large plaque psoriasis, whereas T cells and dendritic cells in total psoriatic skin area were exponentially increased. Negative immune regulators, such as CD69 and FAS, were decreased in both Western large plaque psoriasis and psoriasis with accompanying arthritis or obesity, and their expression was correlated with psoriasis severity index. Based on the disease subtype comparisons, we propose that dysregulation of T-cell expansion enabled by downregulation of immune negative regulators is the main mechanism for development of large plaque psoriasis subtypes.

Multimodal evaluation of xenograft tumors in mice with an in-vivo stereo imaging system and small-animal PET/CT.

In small-animal studies, calipers are the standard method used for measurement of external tumor size. However, as tumors are not usually prolate spheroids, this may lead to inaccuracies in the data. Also, correlations vary according to the kind and size of tumors. Tumors were generated by transplanting B16 mouse melanoma cells into the back of Balb/c nude mice. True volumes were measured by calipers, an in-vivo stereo imaging system, and as a standard uptake value (SUV) by (18)F-fluorodeoxyglucose ([(18)F]FDG)-PET. Correlations between measurements were analyzed. Correlation with the true volume was higher for measurements using the in-vivo stereo imaging system (r = 0.876) than with calipers (r = 0.744). Measurement of melanoma volume has a larger measuring error when performed using a caliper compared with measurements performed by stereo imaging when the volume of the melanoma is small. Correlation of the volume and PET-SUV by a caliper is low as the size of the melanoma increases. This same relationship exists with the comparison of stereo imaging and PET-SUV. The correlation between the SUV of [(18)F]FDG-PET and tumor volume with the melanoma is expected to be important in related future studies.