Fibroblast-derived matrices-based human skin equivalent as an in vitro psoriatic model for drug testing.

Psoriasis is a chronic skin disease characterized by thickening and disorganization of the skin's protective barrier. Although current models replicate some aspects of the disease, development of therapeutic strategies have been hindered by absence of more relevant models. This study aimed to develop and characterize an in vitro psoriatic human skin equivalent (HSE) using human keratinocytes HaCat cell line grown on fibroblasts-derived matrices (FDM). The constructed HSEs were treated with cytokines (IL-1α, TNF-α, IL-6, and IL22) to allow controlled induction of psoriasis-associated features. Histological stainings showed that FDMHSE composed of a fully differentiated epidermis and fibroblast-populated dermis comparable to native skin and rat tail collagen-HSE. Hyperproliferation (CK16 and Ki67) and inflammatory markers (TNF-α and IL-6) expression were significantly enhanced in the cytokine-induced FDM- and rat tail collagen HSEs compared to non-treated HSE counterparts. The characteristics were in line with those observed in psoriasis punch biopsies. Treatment with all-trans retinoic acid (ATRA) has shown to suppress these effects, where HSE models treated with both ATRA and cytokines exhibit histological characteristics, hyperproliferation and differentiation markers expression like non-treated control HSEs. Cytokine-induced FDM-HSE, constructed entirely from human cell lines, provides an excellent opportunity for psoriasis research and testing new therapeutics.

Squamous epitheliotropism of Enterovirus A71 in human epidermis and oral mucosa.

Hand-foot-and-mouth disease is a self-limiting paediatric infectious disease commonly caused by Enterovirus A71 (Genus: Enterovirus, Family: Picornaviridae). Typical lesions in and around the hands, feet, oral cavity and other places may rarely be complicated by acute flaccid paralysis and acute encephalomyelitis. Although virus is readily cultured from skin vesicles and oral secretions, the cellular target/s of Enterovirus A71 in human skin and oral mucosa are unknown. In Enterovirus A71-infected human skin and oral mucosa organotypic cultures derived from the prepuce and lip biopsies, focal viral antigens and viral RNA were localized to cytoplasm of epidermal and mucosal squamous cells as early as 2 days post-infection. Viral antigens/RNA were associated with cytoplasmic vacuolation and cellular necrosis. Infected primary prepuce epidermal keratinocyte cultures showed cytopathic effects with concomitant detection of viral antigens from 2 days post-infection. Supernatant and/or tissue homogenates from prepuce skin organotypic cultures and primary prepuce keratinocyte cultures showed viral titres consistent with active viral replication. Our data strongly support Enterovirus A71 squamous epitheliotropism in the human epidermis and oral mucosa, and suggest that these organs are important primary and/or secondary viral replication sites that contribute significantly to oral and cutaneous viral shedding resulting in person-to-person transmission, and viraemia, which could lead to neuroinvasion.

Impact of socio-economic class on colorectal cancer patient outcomes in Kuala Lumpur and Kuching, Malaysia.

OBJECTIVE: Research over the past several decades has indicated that low socioeconomic class has a direct effect on health outcomes. In Malaysia, class distribution may differ with the region. The objective of this study was to compare the presentation and survival of colorectal cancer patients in two dissimilar cities, Kuala Lumpur and Kuching, Sarawak. METHODS: All patients diagnosed with a malignancy of the colon or rectum in Sarawak General Hospital and University of Malaya Medical Center from 1st Jan 2000-31st Dec 2006 were recruited. Data on presentation, socio-economic class and survival were obtained. The survival duration was categorized into more than three years or three years and less. Testing for significance was performed using the chi-square test, with p values less than 0.05 considered statistically significant. RESULTS: A total of 565 patients in UMMC and 642 patients in SGH had a new diagnosis of colorectal carcinoma. Patients in Kuching had a longer duration of symptoms and more advanced stage at presentation, but this was not statistically significant. Lower socio-economic class was a significant factor for late and more advanced stage at diagnosis, as well as poorer three and five year survival rates. However, survival was lower for patients in Kuching compared to Kuala Lumpur, even after matching for socio-economic class. CONCLUSION: There is near-zero awareness of colorectal cancer screening in Malaysia. These findings support reaching out to communities of lower socioeconomic backgrounds to improve the colorectal cancer survival rates.