Biomedical subjects

Elizabeth Frauenhoffer

Publications and source records attributed to Elizabeth Frauenhoffer.

3 recordsLinked to original sources

PubMed2005

Thyroid lymphoma: a single institution's experience.

BACKGROUND: Primary lymphoma of the thyroid gland is uncommon. METHODS: The tumor registry at the Penn State Milton S. Hershey Medical Center was searched for all patients carrying a diagnosis of thyroid lymphoma. All available records for these patients were examined and information regarding patient and tumor characteristics, clinical presentation, interventions, and survival were tabulated. RESULTS: The average age of patient in our series was 67.5 years. There was a 2.7:1 female to male preponderance. Thirteen (60%) patients presented with thyroid nodule(s). Eleven (50%) presented with aerodigestive tract obstructive symptoms. Sixteen (73%) patients had no pre-existing history of thyroid disease; none had known pre-existing Hashimoto's thyroiditis. CONCLUSIONS: The typical thyroid lymphoma patient is female and elderly with painless thyroid enlargement. Compressive symptoms of the aerodigestive tract are common at presentation and may require urgent intervention. Treatment modalities (XRT, CHOP chemotherapy) and outcomes are distinct from other thyroid malignancies.

Adult↗

PubMed2003

Class I alcohol dehydrogenase is highly expressed in normal human mammary epithelium but not in invasive breast cancer: implications for breast carcinogenesis.

Detoxification of ethanol can contribute to oxidative cellular and DNA damage and, thereby, to carcinogenesis. The potential relevance of this to breast carcinogenesis is suggested by evidence that alcohol consumption is a risk factor for breast cancer. It is, however, not known whether ethanol can be metabolized in breast parenchyma. The goal of this study was to determine whether class I and/or IV alcohol dehydrogenase (ADH), medium chain ADHs that can catalyze oxidation of ethanol, are expressed in human breast parenchyma. Normal and neoplastic human breast tissue specimens were examined for class I and IV ADH mRNA by reverse transcription-PCR, for protein by immunocytochemistry and Western analysis, and for their potential to catalyze NAD(+)-dependent oxidation of ethanol. Together, the findings provide evidence that: (a) class I ADH is the medium-chain ADH that is expressed in human breast parenchyma, specifically in the mammary epithelium; (b) human breast parenchyma can support ADH-mediated oxidation of ethanol; and (c) the expression of class I ADH is dramatically reduced or abrogated in invasive breast cancers. Expression of class I ADH in normal human breast parenchyma was confirmed by probing a multiple human tissue polyA(+)RNA. The unexpected finding of virtual abrogation of expression of class I ADH in invasive breast cancer suggests that the enzyme has some "tumor suppressor" function in the mammary epithelium. The one property of class I ADH fitting this designation is its potential to catalyze the oxidation of the micronutrient/prohormone retinol to retinal, the first step in the biosynthesis of retinoic acid, the principal known mediator of the actions of retinoids important for maintaining epithelia in a differentiated state.

Adolescent↗

PubMed2002

Expression of UGT2B7, a UDP-glucuronosyltransferase implicated in the metabolism of 4-hydroxyestrone and all-trans retinoic acid, in normal human breast parenchyma and in invasive and in situ breast cancers.

Glucuronidation, mediated by UDP-glucuronosyltransferases (UGTs), affects the actions and disposition of diverse endo- and xenobiotics. In the case of catecholestrogens (CEs), glucuronidation is likely to block their oxidation to quinone estrogens that are the putative mediators of CEs' actions as initiators of cancers. The goal of this study was to determine whether UGT2B7, the isoenzyme with a high affinity for 4-hydroxyestrone, is expressed in human breast parenchyma. Glucuronidation of 4-hydroxyestrone has relevance to breast carcinogenesis because quinone metabolites of 4-hydroxylated CEs can form potentially mutagenic depurinating DNA adducts, and because in breast tissue estrone is likely to be the predominant estrogen available for 4-hydroxylation. Using reverse transcriptase-polymerase chain reaction, immunocytochemistry, immunoblot analyses, and assays of glucuronidation of 4-hydroxyestrone, we show that UGT2B7 is expressed in human mammary epithelium, and that its expression is dramatically reduced in invasive breast cancers. In many in situ carcinomas, however, 4-hydroxyestrone immunostaining was not only preserved but even more intense than in normal mammary epithelium. The finding of reduced UGT2B7 protein and glucuronidation of 4-hydroxyestrone in invasive cancers suggests a tumor-suppressor function for the enzyme. Recent identification of all-trans retinoic acid as a substrate of UGT2B7 suggests that this function includes the generation of retinoyl-beta-glucuronide, a potent mediator of actions of retinoids important for maintaining epithelia in a differentiated state. Current knowledge does not provide any ready explanation for the apparent increase in UGT2B7 expression in carcinomas in situ. However, this finding, together with reduced immunostaining at loci showing breach of the basement membrane (microinvasion), suggests involvement of UGT2B7-catalyzed reaction(s) in protection against invasion of surrounding tissue by cancer cells.

Breast↗