William F . Benedict

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In the absence of disease, the vasculature of the mammalian eye is quiescent, in part because of the action of angiogenic inhibitors that prevent vessels from invading the cornea and vitreous. Here, an inhibitor responsible for the avascularity of these ocular compartments is identified as pigment epithelium-derived factor (PEDF), a protein previously shown(More)
Inheritance of a mutation at the Rb-1 locus, which has been mapped to band q14 of human chromosome 13, results in predisposition to retinoblastoma. Cloned DNA segments homologous to arbitrary loci of human chromosome 13 and which reveal polymorphic restriction endonuclease recognition sequences, have been used to look for somatic genetic events that might(More)
Loss of chromosome 13q occurs in up to 50% of human astrocytomas, suggesting the presence of an astrocytoma tumor suppressor gene on that chromosome. To determine whether the retinoblastoma susceptibility gene (Rb) on 13q14 contributes to the formation of astrocytomas, we examined 85 tumors for loss of heterozygosity (LOH) at the intragenic Rb 1.20 locus.(More)
Neuroblastoma cell lines LA-N-1 and LA-N-2 were extablished from neuroblastoma cells in the bone marrow and in the primary tumor, respectively, of two children with metastatic neuroblastoma. Morphology, growth in vitro and in athymic nude mice, chromosomal patter, and fibrinolytic activity of these cell lines and of previously extablished human(More)
PURPOSE To determine whether p53, p21, pRB, and/or p16 expression is associated with bladder cancer stage, progression, and prognosis. PATIENTS AND METHODS Immunohistochemical staining for p53, p21, pRB, and p16 was carried out on serial sections from archival specimens of 80 patients who underwent bilateral pelvic lymphadenectomy and radical cystectomy(More)
RB-protein status as determined by immunohistochemical analysis was compared with loss of heterozygosity (LOH) at the RB locus in 68 primary transitional-cell carcinomas of the bladder. Absence of RB-protein expression was found in 15 of 17 tumors in which LOH at the RB locus was identified, whereas 31 of 36 tumors from informative patients which showed no(More)
Rb protein (pRb) expression was evaluated in 185 cases of transitional cell carcinoma of the bladder from patients that underwent radical cystectomy. Tumors were stratified into three categories based on the percentage of nuclei expressing pRb: (a) 0, 0% of tumor cells showing nuclear reactivity; (b) 1+, 1-50% of tumor cells showing nuclear reactivity; and(More)
Although a constitutional chromosomal deletion including 13q14 has been found to date in all retinoblastoma patients whose esterase D activity is 50 percent of normal, one female patient has been found who has 50 percent esterase D activity in all normal cells examined but no deletion of 13q14 at the 550-band level. Therefore, she has the smallest(More)
BACKGROUND The origin and molecular pathogenesis of parathyroid carcinoma are unknown. This life-threatening cause of primary hyperparathyroidism cannot be reliably distinguished from its benign counterpart on the basis of histopathological features alone. Because the PRAD1, or cyclin D1, gene, a cell-cycle regulator, has been implicated in a subgroup of(More)
BACKGROUND Many cancers display alterations in methylation patterns of CpG islands--stretches of DNA rich in CpG dinucleotides often associated with gene promoters that are involved in initiation of gene transcription. This methylation may perturb expression of genes critical to the regulation of cell proliferation. Aberrant methylation is not limited to a(More)