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Biomedical subjects

Ronald J Barr

Publications and source records attributed to Ronald J Barr.

23 records · Page 2Linked to original sources
PubMed2003

Effect of PTU on IL-12 and IL-10 in psoriasis.

Propylthiouracil (PTU), an antithyroid thioureylene with immunomodulatory properties, has been shown to be effective in the therapy of patients with plaque psoriasis. The mechanism of action of antithyroid thioureylenes in psoriasis remains unknown. Propylthiouracil is a commonly used agent in the treatment of patients with Graves' hyperthyroidism, a condition associated with elevated levels of interleukin-12 (IL-12), which fall significantly after propylthiouracil treatment. IL-12 is believed to play a pivotal role in the development of psoriasis. Production of IL-12 is modulated by the anti-inflammatory cytokine IL-10. The effect of PTU on IL-12 and IL-10 levels was, therefore, studied in twelve patients with plaque psoriasis. Treatment with 300 mg of PTU daily in divided doses for three months produced significant improvement of the PASI and histological scores in the patients. Serum IL-12 concentrations were undetectable at baseline and did not change with treatment. IL-10 concentrations were 1.39 +/- 1.49 pg/ml (mean +/- SD) at baseline, and showed no significant change after 2 weeks (1.63 +/- 1.61 pg/ml and 12 weeks 1.15 +/- 1.58 pg/ml of treatment with PTU. The data suggest that the clinical improvement with patients with psoriasis treated with PTU is not due to a fall in circulating IL-12 or a rise in IL-10 concentrations. Although the drug may have effects on lesional production of these cytokines this is not reflected in the circulating levels. It is speculated that the beneficial effect is likely mediated by an inhibitory effect on keratinocyte proliferation or promotion of apoptosis in these proliferated keratinocytes.

Administration, Oral↗
PubMed2002

Desmoplastic malignant melanoma of the lip: a report of 6 cases and review of the literature.

Desmoplastic malignant melanoma is a rare neoplasm consisting primarily of spindle-shaped melanoma cells embedded in a fibrous stroma, with approximately 6% of cases occurring in the lip. A literature search revealed that most reported cases occur in sun-exposed areas in older men. Few cases of desmoplastic malignant melanoma of the lip in young people (in their mid-twenties) have been described. We report 6 previously undocumented cases of labial desmoplastic malignant melanoma occurring in young individuals and review 20 cases from the literature. Physicians should consider the possibility of desmoplastic malignant melanoma in young people who present with atypical lip lesions, which on histopathologic analysis demonstrate spindle-cell hyperplasia. Although this diagnosis is rare and there have not been reports of such patients in the literature thus far, our findings should alert clinicians to the possibility of desmoplastic malignant melanoma as a diagnosis for lip lesions in young people.

Adult↗
PubMed2002

S100-positive spindle cells in scars: a diagnostic pitfall in the re-excision of desmoplastic melanoma.

Distinguishing desmoplastic melanoma (DM) from scar tissue on routine microscopy can be difficult, especially in re-excision specimens, and S100 immunohistochemistry has been recommended as a useful adjunct. The purpose of this study is to evaluate the extent and nature of S100 positivity in scars. In this study, formalin-fixed paraffin archival tissues were evaluated with immunohistochemistry. Ten re-excision specimens of previously biopsied nonnevomelanocytic lesions were immunostained with the S100 and CD57 (Leu 7) antibodies. In 9 of the 10 cases, the scars contained S100-positive spindle cells, but there were no cases with CD57+ cells. Ten re-excised atypical nevi and 10 re-excised melanomas were also immunostained for the S100 protein, and all 20 cases contained S100-positive spindle cells within the scars. There was a trend toward quantitatively more S100-positive spindle cells in these nevomelanocytic re-excisions. To evaluate the nature of the spindle cells, scars from two of the nonnevomelanocytic re-excisions were further analyzed utilizing immunostains for glial fibrillary acidic protein, HMB-45, Melan-A, CD1a, factor XIIIa, and neuron specific enolase. In both scars, neuron specific enolase diffusely stained the fibroblast population, but the remaining immunostains were negative in the scar. The presence of S100-positive spindle cells in scars represents a potential diagnostic pitfall, particularly in the evaluation of re-excision specimens of DM.

Cell Count↗