Geoffrey J. Gottlieb

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We have investigated the role of the enzyme telomerase in highly proliferative organs in successive generations of mice lacking telomerase RNA. Late-generation animals exhibited defective spermatogenesis, with increased programmed cell death (apoptosis) and decreased proliferation in the testis. The proliferative capacity of haematopoietic cells in the bone(More)
Telomere maintenance is thought to play a role in signaling cellular senescence; however, a link with organismal aging processes has not been established. The telomerase null mouse provides an opportunity to understand the effects associated with critical telomere shortening at the organismal level. We studied a variety of physiological processes in an(More)
Maintenance of telomere length and function is critical for the efficient proliferation of eukaryotic cells. Here, we examine the interactions between telomere dysfunction and p53 in cells and organs of telomerase-deficient mice. Coincident with severe telomere shortening and associated genomic instability, p53 is activated, leading to growth arrest and/or(More)
Aged humans sustain a high rate of epithelial cancers such as carcinomas of the breast and colon, whereas mice carrying common tumour suppressor gene mutations typically develop soft tissue sarcomas and lymphomas. Among the many factors that may contribute to this species variance are differences in telomere length and regulation. Telomeres comprise the(More)
Maintenance of telomere length is predicted to be essential for bypass of senescence and crisis checkpoints in cancer cells. The impact of telomere dysfunction on tumorigenesis was assessed in successive generations of mice doubly null for the telomerase RNA (mTR) and the INK4a tumor suppressor genes. Significant reductions in tumor formation in vivo and(More)
Neoplastic angioendotheliosis is a rare disorder characterized by progressive multifocal neurological deficit and dementia. The principal pathological findings are multiple infarcts in the brain and spinal cord and the microscopical demonstration of proliferated neoplastic cells, primarily within the lumens of arteries, arterioles, and capillaries. Vessels(More)
Dermatopathology represents the gold standard for the diagnosis of skin diseases and neoplasms that cannot be diagnosed on clinical grounds alone. The aim of this study was to test the feasibility and to assess the accuracy of an Internet-based real-time (live) teledermatopathology consultation. Twenty teaching cases and 10 randomly selected routine cases(More)
Analogous to adenomyoepitheliomas of the breast, cutaneous adenomyoepithelioma is composed of two components, one being myoepithelial, the other ductal epithelial, and it lies in the spectrum of neoplasms having a "pure" myoepithelioma at one end and a mixed apocrine tumor at the other. We present the case of a 53-year-old woman with a 3 cm nodular lesion(More)
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