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Biomedical subjects

Allen R Gibbs

Publications and source records attributed to Allen R Gibbs.

6 recordsLinked to original sources
PubMed2005

Evidence against a role for SV40 in human mesothelioma.

SV40 has been implicated in the etiology of 40% to 60% of human mesotheliomas. These studies could have important medical implications concerning possible sources of human infection and potential therapies if human tumors are induced by this agent. We did PCR-based analysis to detect SV40 large T antigen DNA in human mesotheliomas. None of 69 tumors in which a single copy gene was readily amplified contained detectable SV40 large T antigen sequences. Under these conditions, it was possible to detect one copy of integrated SV40 DNA per cell in a mixture containing a 5,000-fold excess of normal cells using formalin-fixed preparations. Kidney, a known reservoir of SV40 in monkeys, from some of these individuals were also negative for SV40 large T antigen sequences. A subset of mesotheliomas was analyzed for SV40 large T antigen expression by immunostaining with a highly specific SV40 antibody. These tumors as well as several human mesothelioma cell lines previously reported to contain SV40 large T antigen were negative for detection of the virally encoded oncoprotein. Moreover, mesothelioma cell lines with wild-type p53 showed normal p53 function in response to genotoxic stress, findings inconsistent with p53 inactivation by the putative presence of SV40 large T antigen. Taken together, these findings strongly argue against a role of SV40 by any known transformation mechanism in the etiology of the majority of human malignant mesotheliomas.

Animals↗
PubMed2005

Pseudomesothelioma resulting from metastatic malignant melanoma.

Isolated pleural metastatic melanoma is an uncommon clinical condition. Clinical diagnosis can be difficult and therapeutic options are limited. We describe a case where there was isolated pleural metastasis, 10 years following complete excision of a superficial melanotic lesion, which presented like a malignant mesothelioma ('pseudomesothelioma').

Diagnosis, Differential↗
PubMed2005

Localized malignant mesothelioma.

Localized malignant mesotheliomas are uncommon sharply circumscribed tumors of the serosal membranes with the microscopic appearance of diffuse malignant mesothelioma but without any evidence of diffuse spread. Little is known about their behavior. We report 23 new cases. The mean age at presentation was 63 years, and the sex ratio was approximately 2:1 (male/female). Twenty-one tumors were pleural and 2 were peritoneal. Sixteen tumors reproduced microscopic patterns of diffuse epithelial mesotheliomas, 6 had mixed epithelial and sarcomatous patterns, and 1 was purely sarcomatous. After surgical excision of the tumor, 10 of 21 patients with follow-up data were alive without evidence of disease from 18 months to 11 years after diagnosis. Patients who died had developed local recurrences and metastases, but none had diffuse pleural spread. Localized malignant mesotheliomas should be separated from diffuse malignant mesotheliomas because of their localized presentation, quite different biologic behavior, and far better prognosis.

Adult↗
PubMed2004

Proposed criteria for mixed-dust pneumoconiosis: definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation.

We defined mixed-dust pneumoconiosis (MDP) pathologically as a pneumoconiosis showing dust macules or mixed-dust fibrotic nodules (MDF), with or without silicotic nodules (SN), in an individual with a history of exposure to mixed dust. We defined the latter arbitrarily as a mixture of crystalline silica and nonfibrous silicates. According to our definition of MDP, therefore, MDF should outnumber SN in the lung to make a pathologic diagnosis of MDP. In the absence of confirmation of exposure, mineralogic analyses can be used to support the pathologic diagnosis. The clinical diagnosis of MDP requires the exclusion of other well-defined pneumoconioses, including asbestosis, coal workers' pneumoconiosis, silicosis, hematite miners' pneumoconiosis, welders' pneumoconiosis, berylliosis, hard metal disease, silicate pneumoconiosis, diatomaceous earth pneumoconiosis, carborundum pneumoconiosis, and corundum pneumoconiosis. Typical occupations associated with the diagnosis of MDP include metal miners, quarry workers, foundry workers, pottery and ceramics workers, and stonemasons. Irregular opacities are the major radiographic findings in MDP (ILO 1980), in contrast to silicosis, in which small rounded opacities predominate. Clinical symptoms of MDP are nonspecific. MDP must be distinguished from a variety of nonoccupational interstitial pulmonary disorders.

Dust↗
PubMed2002

Pulmonary blastoma: medium-term results from a regional center.

BACKGROUND: Pulmonary blastomas are rare lung tumors that morphologically resemble fetal pulmonary structure and can exist in two forms, biphasic and monophasic. We reviewed our experience over a 12-year period with emphasis on the clinical features, management, and outcome. METHODS: Patients with a diagnosis of pulmonary blastoma from January 1988 to July 1999 were identified from the database of the Department of Histopathology, Llandough Hospital, Cardiff. Specimens had been obtained from bronchoscopy, fine-needle aspiration, trucut biopsy, and thoracotomy. RESULTS: Six patients were identified from 2,720 histologically proven lung cancers (0.2%). Median age was 35.5 years and sex ratio was equal. Overall, 4 patients underwent resection and are all alive (median, 43.5 months). Three of these had advanced tumors at presentation (stage IIIb or IV), two of which were successfully downstaged with neoadjuvant chemotherapy, and the third treated with postoperative radiotherapy. Nonresected cases succumbed at a median of 5.5 months. CONCLUSIONS: Although pulmonary blastomas are rare, those affected represent a group of patients with advanced tumors for whom a coordinated approach from both oncologists and surgeons can achieve excellent medium-term results.

Adult↗