Biomedical subjects

K C Ongenae

Publications and source records attributed to K C Ongenae.

3 recordsLinked to original sources

PubMed2001

Microcystic adnexal carcinoma: an uncommon tumor with debatable origin.

BACKGROUND: Microcystic adnexal carcinoma is an uncommon skin appendage neoplasm exhibiting both pilar and sweat duct differentiation. This tumor remains a subject of controversy as to its differentiation profile, histogenesis, and classification which is reflected in the nomenclature used to designate the neoplasm in question. Beyond this controversy the tumor remains a diagnostic challenge because of its rarity, the histologic mimicry it may display, and its banal cytologic appearance; it also poses a therapeutic challenge, as it is characterized by slow but aggressive and destructive local growth extending beyond clinical margins together with a high tendency for perineural invasion and recurrence. OBJECTIVE: We report two cases of this unusual tumor illustrating some of its characteristics. Our review emphasizes the divergent opinions concerning its differentiation profile and its origin. An organoid nevus as the origin of microcystic adnexal carcinoma in one of our patients is discussed in this context.

Adult↗

PubMed2000

Level of fibronectin mRNA is markedly increased in human chronic wounds.

BACKGROUND: Acute wound healing has been extensively investigated over the years, however, little is known about possible healing defects in chronic wounds. Fibronectin (FN) plays a critical role in different phases of wound healing and has been demonstrated to be degraded in chronic wounds by proteases. Fibroblasts cultured from chronic leg ulcers showed a higher level of FN compared to normal fibroblasts. OBJECTIVE: We explored whether the increase in FN protein in chronic wounds is due to increased FN mRNA. In addition, the level of alpha5beta1 integrin FN cell surface receptor was also examined. METHOD: Skin biopsies were taken from normal skin within a few hours of Mohs surgery and from the edge of chronic venous leg ulcers. In situ hybridization was performed to determine the level of FN mRNA. The level of integrin alpha5beta1 was determined by immunohistochemistry. RESULTS: The level of FN mRNA in normal skin and acute wounds was undetectable. In contrast, FN mRNA was heavily induced throughout the dermis of chronic wounds. Immunostaining using a monoclonal antibody against the alpha5 subunit of integrin revealed that chronic wounds and normal skin showed undetectable levels of alpha5beta1 integrin. A large induction of alpha5 was observed in acute wounds. CONCLUSION: For reepithelization to occur, epidermal keratinocytes need to migrate over the wound surface, a process requiring an interaction between FN and its cell surface receptor integrin alpha5beta1. These findings suggest that although FN mRNA is increased in chronic wounds, lack of FN cell surface receptor may prevent migration of epidermal keratinocytes in chronic wounds.

Acute Disease↗

PubMed1999

Intercellular IgA dermatosis.

We report three cases of intercellular IgA dermatosis (IAD) and review the literature. IAD is a spectrum of vesiculobullous or vesiculopustular diseases mediated by intercellular IgA deposition. The clinical picture may vary from a vesiculopustular eruption with centrifugal evolution mainly involving the trunk and extremities, to the typical picture of classic pemphigus variants (foliaceus, vegetans). Histologically, infiltrating polymorphonuclear cells (mainly neutrophils) are observed in the epidermis with formation of pustules and bullae at various levels. However cases with typical histological features of pemphigus (variants) are described. Direct immunofluorescence on perilesonal skin typically displays intercellular IgA deposition at different levels or throughout the epidermis and indirect immunofluorescence often detects low levels of circulating antibodies. The disease has been repeatedly reported in association with monoclonal IgA gammopathy. Most cases respond to dapsone. In some cases IgA is directed against known pemphigus antigens whereas their targets in other cases are newly discovered antigens (105 kD, 115 kD, 120 kD). We observe a heterogeneity within the clinical, histological and immunological characteristics of the disease. Many reported cases feature various combinations of these characteristics. We therefore consider IAD as a disease spectrum with IgA pemphigus (clinical and histological pemphigus) at one end and intercellular IgA vesiculopustular dermatosis at the other end.

Aged↗