Langerhans cells cross-present antigen derived from skin.

Dendritic cells (DC) efficiently cross-present exogenous antigen on MHC class I molecules to CD8+ T cells. However, little is known about cross-presentation by Langerhans cells (LC), the DCs of the epidermis. Therefore, we investigated this issue in detail.

Otopathogenic Pseudomonas aeruginosa strains as competent biofilm formers.

Objective: To determine whether Pseudomonas aeruginosa, a common cholesteatoma pathogen, known to form biofilms in other chronic infections, is capable of contributing to biofilm formation in cholesteatoma.

Design: We tested 12 OPPA isolates for several aspects of biofilm formation, including adherence to human keratinocytes, expression of quorum-sensing genes, twitching motility, and production of extracellular matrix as determined by both crystal violet staining and carbazole reaction.

Results: Ten OPPA strains demonstrated increased adherence (1.

A possible role for nitric oxide in osteoclastogenesis associated with cholesteatoma.

Hypothesis: This study was designed to investigate the potential role of nitric oxide in cholesteatoma-induced bone resorption, in vitro and in vivo.

Background: Cholesteatoma is a disease of inflammatory bone resorption in the middle ear leading to hearing loss and vestibular dysfunction. Inappropriate activation of osteoclasts causes the morbidity associated with this disease.

Cellulose production by Gluconacetobacter hansenii in a medium containing ethanol.

The addition of 1% (v/v) ethanol to the basal medium inhibited growth of Gluconacetobacter hansenii but decreased the numbers of non-cellulose producing cells. Cellulose production increased 1.7 times to approx.

Zoledronic acid inhibits osteoclastogenesis in vitro and in a mouse model of inflammatory osteolysis.

This study assessed effects of the bisphosphonate zoledronic acid (ZLNA) on osteoclastogenesis. To assess the effect of ZLNA on osteoclast formation in vitro, we cultured mouse bone marrow cells under conditions that promote osteoclastogenesis. Administered at concentrations from 10(-6) to 10(-9) mol/L, ZLNA led to a dose-dependent inhibition of osteoclastogenesis.

Nitric oxide synthase I mediates osteoclast activity in vitro and in vivo.

Bone resorption is responsible for the morbidity associated with a number of inflammatory diseases such as rheumatoid arthritis, orthopedic implant osteolysis, periodontitis and aural cholesteatoma. Previous studies have established nitric oxide (NO) as a potentially important mediator of bone resorption. NO is a unique intercellular and intracellular signaling molecule involved in many physiologic and pathologic pathways.

Bone resorption in chronic otitis media: the role of the osteoclast.

Most of the pathology associated with cholesteatoma is the result of osteoclast-mediated bone resorption in the middle ear. Cytokines, prostaglandins, nitric oxide, neurotransmitters and growth factors are associated with chronic inflammation and have been implicated in cholesteatoma-induced bone resorption. Although many different factors are known to regulate osteoclast activation, there is a final common pathway of osteoclast differentiation and resorption.