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Biomedical subjects

L D True

Publications and source records attributed to L D True.

62 records · Page 4Linked to original sources
PubMed1985

Large cell carcinoma of the lung. Ultrastructural differentiation and clinicopathologic correlations.

Light microscopic biopsy specimens from 48 patients were reviewed by two independent pathologists and classified as large cell carcinoma of the lung by 1981 World Health Organization (WHO) criteria. Sites of primary disease were hilar/mediastinal in 26 patients, large mid-lung field in 17, and peripheral lung in 5. All material was examined by electron microscopy (EM) for evidence of squamous ("squamous": 15 patients), glandular ("adenocarcinoma": 17 patients), or nonspecific ("large cell": 14 patients) ultrastructural differentiation. Two patients had mixed adenosquamous features. There were 6 patients with Stage I tumors; 5, Stage II; 24, Stage IIIM0; and 13, Stage IIIM1. Of the 14 patients with large cell by EM, 11 had unresectable Stage IIIM0 or metastatic disease. Only 3 of 27 patients not undergoing resection responded to combined modality therapy. There were two long-term survivors free of disease in the resected Stage IIIM0 patient category. Overall median survival by stage was analyzed, with no statistically significant difference between several of the stage groupings, suggesting a worse prognosis for the entire group overall compared to all patients with non-small cell lung cancer. The median survival by EM subgroup was also without significant difference, both overall and within various stage groupings, despite more patients in the large cell category with advanced disease. These data support the unique behavior of patients with large cell carcinoma on light microscopy, but fail to demonstrate that ultrastructural differentiation is of prognostic importance for response or survival.

Adenocarcinoma↗
PubMed1985

Keratin expression in normal esophageal epithelium and squamous cell carcinoma of the esophagus.

The 8-nm keratin filament is a major component of the cytoskeleton of epithelial cells and epithelial-derived cancers (carcinomas). Recently, it has been shown that the pattern of keratins produced by an esophageal epithelial cell undergoes change upon malignant transformation. In order to evaluate the potential importance of these differences in providing improved diagnostic techniques for pathology, we have investigated the consistency of the patterns of keratins expressed in normal esophageal epithelium, squamous cell carcinoma (SQCC) of the esophagus, and cultured esophageal epithelial cells. In six patients, the keratin pattern expressed by SQCC of the esophagus and corresponding normal esophageal epithelium was consistently different as judged by immunoblot analysis of electrophoretically separated protein extracts. Whereas the SQCCs typically expressed major keratins with molecular weights of 58,000, 56,000, 50,000, and 46,000, the normal esophageal epithelium produced two major keratins with molecular weights of 58,000 and 52,000 and a minor keratin with a molecular weight of 56,000. When normal esophageal epithelial cells were grown in tissue culture, their keratin pattern changed, and keratins with molecular weights of 58,000, 56,000, 52,000, 50,000, 46,000, and 40,000 were expressed. Although some minor variations in keratin patterns were seen, the major differences in keratin pattern expressed by normal esophageal epithelial tissue, SQCC of the esophagus, and cultured esophageal cells were consistent and reproducible.

Antibody Specificity↗
PubMed1982

The role of electron microscopy in the management of surgical patients.

This report records a 12-month experience with 49 neoplasms submitted to the hospital pathologists for electron microscopic (EM) diagnosis as a part of routine clinical surgical practice. Twenty-five specimens were from a private community hospital and 24 from a university hospital. In 40 of 49 cases (82%), EM confirmed a tentative light microscopic (LM) diagnosis. In 11 of these 40 cases, EM provided a more specific histogenetic diagnosis than was possible by LM. In three cases (6%), EM corrected the original LM diagnosis. In two cases EM did resolve a diagnostic dilemma. EM is a beneficial adjunct to the correct diagnosis of selected tumors. Although in general EM does not help differentiate benign from malignant tumors, it is helpful in identifying the cell of origin of poorly differentiated neoplasma. A more precise histogenetic diagnosis was judged to be clinically helpful in 56% of th cases studied in this experience. EM is a relatively inexpensive ($115-250) and prompt (three to five days) adjunct to surgical care. It should be routinely available to the practicing surgeon for help in determining the cell type of confusing tumors. EM is no longer simply a research tool.

Adult↗
PubMedDate not supplied

Aberrant hormone production from ovarian neoplasms: strategies for diagnosis and therapy.

Syndromes involving peptide or nonsex steroid hormone secretion due to aberrantly located tumors are rare. We report a collected series of 16 patients with ectopic hormone production from ovarian neoplasms, including 3 patients recently encountered at our institution as well as 13 additional cases identified in the recent literature. These tumors included 2 insulin-producing ovarian carcinoids, 1 ACTH-producing pituitary adenoma within a benign ovarian cystic teratoma, 2 cortisol-producing ovarian neoplasms, 8 gastrin-producing ovarian cystadenomata or cystadenocarcinomata, and 3 thyroxine-producing ovarian strumal carcinoids. All patients presented with syndromes of hormone excess. Only 62% of all tumors were localized preoperatively. Following ovarian resection, 87% of patients remained disease-free with a median follow-up period of 1.5 years. In addition to ovariectomy, 8 additional unnecessary ablative procedures were performed in 7 patients. These included distal pancreatectomy, pancreaticoduodenectomy, adrenalectomy, total gastrectomy, selective vagotomy, and subtotal thyroidectomy. Failure to localize the ovarian neoplasm preoperatively was associated with a significantly higher risk of subsequent unnecessary ablative procedures. Because of the potential for the ovary to act as a source of aberrant hormone secretion, we recommend complete preoperative evaluation of the pelvis in female patients presenting with nonlocalizable endocrine tumors.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Image processing for the rest of us: the potential utility of inexpensive computerized image analysis in clinical pathology and radiology.

Recent progress in computer technology in both hardware and software, combined with marked cost reductions, have placed quantitatively accurate video densitometry systems within the reach of the individual clinician, biomedical researcher, and community hospital. While much of the attention generated by advances in image processing has focussed on larger scale procedures, such as CAT, chemical shift, and positron emission tomography, important applications can be found for considerably more modest systems. In this article, we discuss three such applications of DUMAS, a personal computer-based imaging system developed by the Image Processing Center at Drexel University. A potential technique for quantifying numbers of estrogen receptors in tumorous breast tissue samples as a predictor of patient responsiveness to hormonal therapy is described first, along with possible sources of error. The second application, also related to clinical pathology and cancer, outlines methods for relating changes in nuclear and cell morphology to the diagnosis of Sezary Cell Syndrome. The utility of binary image filtering methods in the classification of cell types is discussed. The third application involves the development of a semi-automatic procedure for the determination of vessel diameter in arteriograms. A detailed description of the optimization and curve-fitting algorithms is provided along with preliminary test results comparing various approaches. The need for user demand to fuel research and development in small-scale imaging systems is also discussed.

Algorithms↗