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Biomedical subjects

R J Barr

Publications and source records attributed to R J Barr.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cutaneous lymphoepithelial neoplasms.

Lymphoepithelial neoplasms are a heterogeneous group of biphasic tumors that contain both epithelial and lymphoid components. Most of these tumors are primarily epithelial with a secondary lymphoid infiltrate and illustrate the basic cell trafficking that occurs in the skin. Included are benign cutaneous lymphadenoma, malignant lymphoepithelioma-like carcinoma, heterotopic dermal thymus, and several miscellaneous lesions that may have a prominent lymphoid infiltrate. Familiarization with their characteristic features will aid in the recognition of these relatively uncommon but often distinct entities.

Adenolymphoma↗
PubMed1996

Epidermolytic hyperkeratosis in nevi. A possible marker for atypia.

Epidermolytic hyperkeratosis (EH) has been described as a reaction pattern in a variety of solitary skin lesions. We have noted that EH seems to occur more frequently in association with atypical than with typical acquired nevi. To support or refute this observation, the prevalence of EH in 250 cases of atypical compound nevi and in 250 cases of typical compound nevi was determined. EH was identified in 10 cases of atypical compound nevi and in two cases of typical compound nevi, which is a statistically significant difference with p value < 0.02. Since EH occurred in only 4% of atypical nevi examined, it should not be considered a diagnostic criterion. However, the identification of EH in otherwise histologically typical nevi should prompt the pathologist to make sure the lesion has been adequately sampled.

Cell Nucleolus↗
PubMed1996

Cutaneous pseudosarcomatous polyp: a histological and immunohistochemical study.

Two unusual acquired polypoid skin lesions exhibited prominent histological atypia, but were biologically benign. Both patients were elderly females. The lesions clinically mimicked fibroepithelial polyp or nevus lipomatosus. Both had been present for about 20 years. One lesion was located on the back, the other on the posterior thigh. Each lesion exhibited dilated, hyalinized vessels in the dermis with focal fibrin deposits, myxoid stroma, and a population of bizarre, pleomorphic spindle to stellate cells, some of which were multinucleated. Occasional atypical mitoses were present. One lesion had abundant admixed fat. Immunohistochemical staining was strongly positive only for vimentin. The lesions share features with degenerating angiofibroma and vaginal pseudosarcomatous polyp. As in these lesions, the atypia is most probably reactive and degenerative.

Aged↗
PubMed1995

Antineoplastic agents, 301. An investigation of the Amaryllidaceae genus Hymenocallis.

Seven species (and one cultivated variety) of Hymenocallis (Amaryllidaceae) and the related Pancratium maritima, representing a broad geographical selection, were investigated as sources of pancratistatin [1] now undergoing preclinical development as an anticancer agent. Pancratistatin [1] was found to be a constituent of H. speciosa (Singapore), H. variegated (Singapore), H. pedalis (Seychelles), H. expansa (Bermuda), H. sonoranensis (Mexico), and P. maritimum (Israel). Only two species of Hymenocallis failed to yield one or more of the related cell-growth inhibitory isocarbostyrils such as narciclasine [3a], 7-deoxynarciclasine [3b], and 7-deoxy-trans-dihydronarciclasine [2].

Amaryllidaceae Alkaloids↗
PubMed1995

Effect of orally administered antithyroid thioureylenes on PCNA and P53 expression in psoriatic lesions.

BACKGROUND: Antithyroid thioureylenes are effective agents in the oral and topical treatment of patients with chronic plaque psoriasis. METHOD: The effect of oral treatment with 6-n-propyl 2-thiouracil (propylthiouracil, PTU) and 2-mercapto 1-methyl imidazole (methimazole, MMI) on proliferating cell nuclear antigen (PCNA), and p53 protein expression was studied in patients with stable plaque psoriasis. RESULTS: Following treatment with PTU and MMI, PCNA staining in psoriatic epidermis was significantly decreased. P53 was minimally expressed in untreated lesions, and treatment with PTU and MMI did not enhance p53 expression in the psoriatic lesions. CONCLUSIONS: Since PCNA is a marker of cellular proliferation and p53 inhibits cellular cycling, some of the beneficial effects of PTU and MMI in psoriasis may depend on the ability of the drugs to impair cellular turnover, perhaps by binding to the triiodothyronine (T3) receptor. These effects may be in addition to the previously described effects of PTU and MMI as immune modulators and free radical scavengers.

Administration, Oral↗
PubMed1995

Halo nevus or halo phenomenon? A study of 142 cases.

One hundred and forty-two (142) halo nevi were reviewed. For 66 cases the diagnosis of halo nevus was made both clinically and pathologically, and for 76 cases the diagnosis was based on histological grounds alone. The nevi were classified by type and by degree of atypia. Of the 142 nevi, all were compound, junctional, or intradermal nevi except for one case of a Spitz nevus and two cases that could not be further classified. For those with a clinicopathological diagnosis of halo nevus, 11% exhibited moderate atypia; 16% exhibited minimal atypia to only focally moderate atypia; 24% minimal atypia; and 49% exhibited no significant atypia. For those cases where the diagnosis was pathological only, there was also a broad spectrum of atypia identified, with 8% exhibiting focally severe or severe atypia. This study supports the concept that the halo nevus should not be regarded as a single clinicopathological entity, but rather that the halo phenomenon occurs in a wide spectrum of nevus types exhibiting a wide spectrum of histological atypia. The pathologist is therefore encouraged to classify halo nevi on the basis of the nevus cell population alone, using whatever classification normally utilized.

Abdomen↗
PubMed1994

A controlled trial of topical propylthiouracil in the treatment of patients with psoriasis.

BACKGROUND: Propylthiouracil (PTU, 6-n-propyl 2-thiouracil) is an antithyroid thioureylene, which, in addition to its ability to decrease thyroid hormone synthesis, also has immune modulatory and free radical scavenging abilities. We have previously shown that oral PTU and another antithyroid thioureylene are effective in the treatment of plaque psoriasis. OBJECTIVE: The current study was performed to determine the efficacy of topical PTU in psoriasis. METHODS: Topical PTU and placebo were administered, in a double-blind fashion, three times daily for 4 to 8 weeks to nine volunteers with long-standing plaque psoriasis. The patients had biopsy specimens of their lesions taken at the start and end of the study. Clinical response was monitored with a scoring system based on scale, erythema, and thickness of the plaques. Complete blood cell count and thyroid function studies were obtained in each patient at the beginning and at 2-week intervals thereafter until completion of the study. RESULTS: Topically applied PTU produced significant clearing of the lesions (clinical scores 8.0 +/- 0.6 vs 3.7 +/- 0.3, p < 0.0001 at 4 weeks, and 4.0 +/- 0.6, p < 0.02 at 8 weeks); two patients demonstrated nearly complete clearing. Placebo-treated and untreated "control" areas showed no significant change during the study. None of the subjects had hypothyroidism or cytopenia. CONCLUSION: Topical applied PTU is effective in the treatment of patients with stable plaque psoriasis and has low toxicity.

Administration, Topical↗
PubMed1994

Genetic linkage of familial expansile osteolysis to chromosome 18q.

Familial expansile osteolysis is a rare bone dysplasia which is transmitted as an autosomal dominant trait in a large kindred in Northern Ireland. The gene which causes the disease shows tight linkage with several polymorphic markers on chromosome 18q with a maximum lod score of 11.53 at a recombination fraction of 0.00 with D18S64. The gene is flanked by D18S35 and D18S61 and is located at chromosome 18q21.1-q22. Mapping a new locus for a gene involved in regulation of bone metabolism may also have implications in the study of Paget's disease of bone which is a common related bone dysplasia.

Animals↗
PubMed1994

Smooth-muscle proliferation in dermatofibromas.

Although a variety of epithelial changes have been associated with dermatofibromas, mesenchymal proliferations induced by dermatofibromas appear to be rare. We report three dermatofibromas that were associated with proliferation of smooth muscle within the adjacent dermis. The lesions ranged from a large, densely cellular dermatofibroma with "monster cells" to a sparsely cellular, fibrous lesion. In all three cases, the smooth muscle could be discerned in hematoxylin- and -eosin-stained sections, because its presence caused an interruption in the pattern of reticular dermal collagen bundles with blunt-ended vesicular nuclei. Well-formed fascicles were apparent in immunoperoxidase-stained sections using antisera to muscle-specific actin (HHF-35) and desmin. The smooth muscle failed to stain with either antisera to S-100 protein or Leu-7, precluding determination of whether it immunophenotypically resembled vascular or pilar smooth muscle. We believe that the smooth-muscle proliferation in our cases was induced by the spindled cells of dermatofibroma, just as epithelial changes in association with dermatofibroma are. We further believe that it is most likely of vascular derivation, based on a previous report of angioleiomyoma arising in a dermatofibroma as well as the continuity of fascicles of smooth muscle with a thick-walled vessel in one of our cases. Less likely explanations include collisions between dermatofibromas and leiomyomas or divergent differentiation in a proliferation arising from primitive mesenchymal cells.

Aged↗
PubMed1994

Epithelioid cell histiocytoma. A report of 10 cases including a new cellular variant.

Epithelioid cell histiocytoma is a recently recognized lesion that is considered to be a variant of cutaneous fibrous histiocytoma (dermatofibroma). Ten cases are presented, including their light microscopic, immunohistochemical, and ultrastructural features. Eight of the cases are similar to those previously reported, presenting as elevated nodules arising on the extremities and composed of epithelioid histiocytes with overlying epidermal effacement. Two of the cases were composed of cells with the same morphologic and immunohistochemical characteristics as typical epithelioid cell histiocytoma, including factor XIIIa positivity, but these arose in the reticular dermis and exhibited prominent cellularity.

Adult↗
PubMed1994

Nevi--an update.

The Council on Scientific Affairs of the California Medical Association presents the following inventory of items of progress in dermatology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of these items of progress in dermatology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on Dermatology of the California Medical Association, and the summaries were prepared under its direction.

Humans↗
PubMed1994

The many faces of completely regressed malignant melanoma.

The prognostic significance of clinical and histologic regression of malignant melanoma is highly controversial. Although small foci of regression in evolving malignant melanomas seem to have little or no effect on morbidity and mortality, extensive regression in larger, fully evolved lesions may be associated with poor prognosis. This chapter emphasizes the histologic features of regression and the patterns that are responsible for diagnostic pitfalls.

Diagnosis, Differential↗
PubMed1993

Diclofenac induced hepatitis. 3 cases with features of autoimmune chronic active hepatitis.

Diclofenac is a frequently prescribed nonsteroidal antiinflammatory drug (NSAID). Significant hepatotoxicity related to diclofenac may be more common than previously recognized, as three patients with diclofenac-associated hepatitis were seen by one clinician in a single year. All patients were ANA positive during the hepatitis and had histologic features of chronic active hepatitis. Two had been inappropriately treated with corticosteroids. The third patient presented more acutely with jaundice and symptoms of hepatitis. Two of the patients developed the same hepatic reaction when rechallenged with diclofenac. The third patient was changed to tiaprofenic acid, a NSAID of the same family, and redeveloped evidence of hepatotoxicity. All three were subsequently able to take naproxen without liver dysfunction. Diclofenac-induced liver disease may be misdiagnosed. Twenty-six cases of significant hepatic reactions to diclofenac have been previously reported in the literature and are reviewed. Such hepatic reactions to diclofenac and related NSAIDs may be commoner than realized. Introduction of a NSAID of another class appears to be safe.

Aged↗
PubMed1993

Propylthiouracil in psoriasis: results of an open trial.

BACKGROUND: Propylthiouracil (PTU) is an antithyroid thioureylene that has immune modulatory and free radical scavenging abilities. In view of the immunomodulatory effects of PTU, we decided to study the therapeutic response of patients with psoriasis to oral PTU. OBJECTIVE: Our purpose was to study the effect of oral PTU in patients with stable plaque psoriasis. METHODS: Oral PTU, 100 mg, was administered every 8 hours for 8 weeks to 10 patients with long-standing psoriasis. Skin biopsy specimens were taken from the lesions before and at the end of the study. Clinical response was monitored with the Psoriasis Area and Severity Index scoring system. Histologic scores were graded with a 5-point grading scale. Complete blood cell count was obtained at the beginning and at the end of the study. Thyroid-stimulating hormone (TSH) was obtained at the beginning and every 2 weeks thereafter until completion of the study. RESULTS: Three patients dropped out of the study. Of the remaining seven, two showed near-complete resolution of their psoriatic lesions, whereas the remainder showed moderate improvement in their clinical scores. Histologic scores were significantly improved in the group with all but one patient showing improvement or no change. Thyroid function tests were unchanged in all but one patient who showed a slight increase in serum TSH at the sixth week of therapy. CONCLUSION: Because of its low toxicity relative to other oral treatments of psoriasis, PTU may have a role in the treatment of patients with this disorder.

Administration, Oral↗