Multisection-multiecho MR imaging: effect on image quality

An analysis of the effects of multisection-multiecho imaging on signal intensity is presented using a gaussian excitation pulse. The number of sections acquired, size of the intersection gap, and the number of echoes were all varied independently to evaluate their effect on image intensity. The results indicate that one should take a conservative approach in multisection-multiecho imaging, leaving at least a 2-mm-intersection gap and approximately a 20-msec delay between section excitations to avoid image signal loss owing to partial saturation effects.     

In vivo and in vitro enhanced antitumor effects by pentoxifylline in human cancer cells treated with thiotepa

Methylxanthines enhance lethality of alkylating agents in human cancer cells, a phenomenon attributed to the prevention of DNA repair. Pentoxifylline is a nontoxic methylxanthine, used clinically for claudication. Using human cancer cells in culture or in a mouse xenograft model, we studied combination treatments with alkylating agents and pentoxifylline or other methylxanthines. With human bladder cancer cells in culture, cytotoxicity of thiotepa was increased up to 10-fold (P less than 0.01) by posttreatment with pentoxifylline, with a major clinical metabolite of pentoxifylline, or with caffeine; the pentoxifylline concentrations required (0.4-1.0 mM) are clinically achievable in the bladder after nontoxic p.o. doses. With human bladder or breast cancer xenografts in a modified subrenal capsule assay, enhancement of thiotepa was also observed by in vivo posttreatment with pentoxifylline. In contrast, these combinations produced no increased toxicity to normal tissues in these animals, measured by weight, lethality, or histological changes of the normal bladder urothelium. These results provide evidence for a novel approach to improve the therapeutic index of thiotepa and other alkylators, used for topical therapy of bladder cancer and, possibly, systemic therapy of other malignancies.     

Autoantibodies to melanocytes and characterization of melanophages in patients affected by a new variant of endemic pemphigus foliaceus

Background: Melanin and melanophages are commonly seen under the basement membrane zone of the skin in patients affected by a new variant of endemic pemphigus foliaceus in El Bagre, Colombia (El Bagre‐EPF). Objective: Our study was conducted to determine the nature of these pigmentary alterations. Methods: We utilized clinical, histopathologic and immunologic techniques including direct and indirect immunofluorescence, immunohistochemistry, Bielschowsky staining and immunoelectron microscopy studies. Results: In the El Bagre‐EPF patients, we detected dermal melanin in melanophages and antigen‐presenting cells, in close proximity to neural and vascular markers. The melanophages consisted of a mixed population expressing CD68, myeloid/histoid antigen and S‐100 protein. By immunoelectron microscopy, the presence of autoantibodies in proximity to melanin granules was confirmed within the melanocytes utilizing 10‐nm gold particles. Conclusion: Dermal antigen‐presenting cells, including melanophages, seem to contain a diverse combination of molecules, representative of an immunologic process where these cells are engulfing both autoantigens and/or cellular debris in El Bagre‐EPF. Autoantibodies to discrete components of melanocytes were also identified; the clinical and immunologic significance of these findings remains unknown. Our work may provide a possible explanation of a darkened complexion in patients affected by endemic pemphigus foliaceus. Abreu Velez A M, Yi H, Googe PB Jr, Mihm MC Jr, Howard MS. Autoantibodies to melanocytes and characterization of melanophages in patients affected by a new variant of endemic pemphigus foliaceus.     

Giant-sized condyloma of the breast with focal acantholytic changes

BACKGROUND: A healthy 26-year-old pregnant woman presented with a 6.0-cm exophytic mass in her left inframammary fold. The lesion was surgically excised. METHODS: Histopathologic sections of the skin lesion were reviewed in hematoxylin and eosin-stained slides. Additional sections were studied by an in situ hybridization method for human papillomavirus DNA (HPV) types 6 and 11. RESULTS: The histopathologic examination demonstrated a benign exophytic, verrucous and papillary epidermal proliferation with features of condyloma acuminatum. Reactivity to HPV DNA types 6 and 11 was demonstrated by in situ hybridization method. The epidermis adjacent to, and focally within, the neoplasm showed multiple areas of suprabasilar and intraepidermal acantholysis without dyskeratosis. CONCLUSIONS: Condylomas related to HPV 6 and 11 may be found in extragenital locations including conjunctiva, oral and nasal mucosa. To our knowledge, however, the extragenital condylomas described in the literature have not included the giant-sized variant. We describe an example of a benign, giant-sized condyloma acuminatum of the breast with nearby acantholytic alterations similar to Hailey-Hailey disease.