Hiroo Yasui

A case of cutaneous odontogenic sinus.

Despite the fact that cutaneous sinus tracts of odontogenic origin are well documented, the condition is still commonly misdiagnosed, because chronic periapical periodontitis may be asymptomatic and is rarely open to the skin. A 75‐year‐old Japanese woman presented to our clinic with the chief complaint of a left cheek skin lesion with mild pain. Physical examination revealed a subcutaneous nodule covered with erythematous skin on her left buccal region. Cultures from the subcutaneous nodule grew Bacteroides species and Peptostreptococcus micros but did not yield acid‐fast bacilli, fungi, or Actinomyces. Stains of smeared pus showed a considerable number of Gram‐negative rods. The histopathological examination revealed a focal abscess formation in the lower dermis and subcutaneous tissue. Dental evaluation, including an orthopantogram, showed a radiolucent alveolar area at the left lower first molar apex, suggesting a periapical abscess. Antibiotic therapy for three weeks associated with surgical root canal therapy eliminated the subcutaneous nodule. A high degree of suspicion is required to correctly diagnose a lower facial lesion as being of odontogenic origin, and prompt dental evaluation should be considered.

Establishment and characterization of a novel human cell line exhibiting both immunophenotypic markers of monocyte/macrophage and natural killer cell lineages from peripheral blood of a patient with atopic dermatitis

Abstract Large amounts of homogeneous cells are not always available for in vitro studies of inflammatory skin disorders. Here we demonstrate that a novel cell line, termed YAA, has been established from peripheral blood mononuclear cells, which were separated by the Ficoll method, of a patient with atopic dermatitis. YAA cells were grown in suspension culture. The cytochemical staining showed a positive reaction for α‐naphthyl butyrate esterase, which was completely inhibited by sodium fluoride, but a negative result for periodic acid‐Schiff, peroxidase and alkaline phosphatase. A large population of YAA cells exhibited phenotype of CD33 and CD56 but neither of CD2 nor CD3. The phorbol ester‐stimulated YAA cells produced a considerable amount of tumor neerosis factor‐α. These findings suggest that YAA might be a monocytoid line with an additional phcnolype specific for natural killer cells.

Ganglioside Profiles of Merkel Cell Carcinoma

Merkel cells are located mainly in the epidermis and considered to have a regulatory role in the growth and differentiation of keratinocytes. On account of their biological behavior, Merkel cells are thought to belong to “paraneurons”(Fujita 1989). Although many kinds of functions of these cells have been clarified, their origin is still unknown. Therefore, we analyzed the ganglioside compositions of Merkel cell carcinomas in order to discuss their origin and metastatic potency.