I. Kurokawa

Trichilemmoma: an immunohistochemical study of cytokeratins

Summary Background The histogenesis of trichilemmoma remains unclear.

Expression of androgen receptors in skin appendage tumors: An immunohistochemical study

Androgen receptor (AR) expression was examined in normal skin and in 52 cases of various skin appendage tumors using a monoclonal antibody (F39.4.1) raised against the N‐terminal domain of human AR. Microwave oven heating in citrate buffer solution followed by immunostaining with the labeled streptavidin biotin (LSAB) method was applied to formalin‐fixed paraffin‐embedded sections. Immunoreactive AR was restricted to the nuclei. In normal skin, AR was consistently localized in seboblasts and in some differentiated sebocytes, and variable expression was seen in luminal epithelial cells of eccrine and apocrine glands in the secretory portion. Hair follicles and epidermis showed no reactivity. In sweat gland tumors, AR was identified locally in inner layer cells of the tubuloglandular component of ten of thirteen chondroid syringomas but the remaining tumors were nonreactive. In sebaceous gland tumors, benign tumors with mature sebaceous elements (sebaceous nevi and sebaceous adenomas) showed AR expression, but the sebaceous epitheliomas and sebaceous carcinomas lost their expression. No AR expression was observed in hair follicle tumors, except in AR‐positive mature sebaceous glands incorporated into the cyst wall of steatocystomas.

Clinical and bacteriologic evaluation of OPC-7251 in patients with acne: A double-blind group comparison study versus cream base

Twenty-eight patients with acne were assigned to 4 weeks of treatment with OPC-7251 (a new fluoroquinolone derivative) 1% cream or the cream base in a double-blind manner to evaluate the antibacterial effect of the drug on resident bacteria in the hair follicles and to evaluate clinical response. Propionibacterium acnes was isolated from 21 of the 28 acne patients. When the number of P. acnes was compared before and after treatment, the posttreatment P. acnes count in the OPC-7251 1% cream group was significantly (p = 0.000) reduced compared with that in the cream base group. OPC-7251 1% cream was also significantly (p = 0.019) superior to the cream base in terms of clinical response. P. acnes and Staphylococcus epidermidis isolated from the acne lesions were selected for their susceptibility to various antibacterial agents. The minimal inhibitory concentration of OPC-7251 against P. acnes and S. epidermidis was 0.10 to 0.20 and 0.024 to 0.10 micrograms/ml, respectively, which indicates that the drug has a potent antibacterial effect.

The antibiotic susceptibility of Propionibacterium acnes: a 15-year bacteriological study and retrospective evaluation.

Propionibacterium acnes strains were isolated from the comedones of 46 acne patients, and their susceptibilities to penicillin G, ampicillin, erythromycin, clindamycin, tetracycline, doxycycline, minocycline, cephalexin and gentamycin were studied by examining their minimum inhibitory concentrations. Two additional standard strains were included in the study. In the results, differing antibiotic susceptibilities were found, and P. acnes strains were the most sensitive to erythromycin and clindamycin, followed by ampicillin and minocycline. The highest levels of resistance were observed against clindamycin, erythromycin and tetracycline. Non‐resistant strains were detected only against minocycline. A comparison of these results with others obtained by similar studies in our department during the last 15 years showed a progressive tendency toward antibiotic resistance for Propionibacterium acnes, probably related to the systemic administration of antibiotics for the treatment of bacterial infections other than acne.

Effects of subminimal inhibitory concentrations of minocycline on neutrophil chemotactic factor production in comedonal bacteria, neutrophil phagocytosis and oxygen metabolism

SummaryComedonal bacteria, Propionibacterium acnes, P. granulosum and coagulase-negative staphylococci (CNS) seem to play an important initiating role in the inflammatory process by producing neutrophil chemotactic factors. The attracted neutrophils, after phagocytosis, release inflammatory factors such as reactive oxygen species (ROS). We investigated the effects of minocycline at subminimal inhibitory concentrations (sub-MIC), i.e. one-tenth MIC, on the production of human neutrophil chemotactic factors in comedonal bacteria, and on several inflammatory parameters of neutrophils, including neutrophil phagocytosis and generation of ROS (O2−, H2O2, O

Immunohistochemical study of cytokeratins in hidradenitis suppurativa (acne inversa).

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Immunohistochemical expression of bone morphogenetic protein-2 in pilomatricoma.

). ROS generation in a cell-free, xanthinexanthine oxidase system was also assessed. Production of neutrophil chemotactic factors in all strains of P. acnes, P. granulosum and CNS were significantly suppressed by sub-MIC minocycline. Sub-MIC minocycline effectively reduced three kinds of neutrophil-generated ROS (O2−, H2O2, O