The nature of retinoblastoma. II. Photoreceptor differentiation: an electron microscopic study.
TL;DR: In this histopathologic study of retinoblastomas exhibiting an unusual form of dif ferentiation, it seemed apparent that these tumors were producing structures resem bling elements of the photoreceptor cell.
About: This article is published in American Journal of Ophthalmology.The article was published on 1970-03-01. It has received 129 citations till now. The article focuses on the topics: Photoreceptor cell.
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TL;DR: It is reported that expression of a viral oncogene, the simian virus 40 T antigen, in the retina of transgenic mice produces heritable ocular tumours with histological, ultrastructural and immunohis-tochemical features identical to those of human retinoblastoma.
Abstract: Retinoblastoma, a malignancy of the eye occurring in young children, has been widely studied as a model for genetic predisposition to cancer. This disease is caused by mutations in both alleles of an anti-oncogene (the retinoblastoma gene, Rb) that inactivate or eliminate the Rb encoded protein, p105Rb (refs 1 and 2). Here we report that expression of a viral oncogene, the simian virus 40 T antigen, in the retina of transgenic mice produces heritable ocular tumours with histological, ultrastructural and immunohistochemical features identical to those of human retinoblastoma. Furthermore, we demonstrate a specific association between p105Rb and T antigen in mouse retinoblastoma tumour cells. Thus, the occurrence of these tumours is in vivo evidence for oncogenesis due to the ocular-specific expression of an Rb-binding oncoprotein that can functionally inactivate the Rb protein. As an animal model for heritable retinoblastoma, these mice should allow the study of the ontogeny, pathogenesis and treatment of this malignant disease.
242 citations
TL;DR: The embryonal central nervous system (CNS) neoplasms are reviewed with special reference to their differentiating potential and in the light of current neuro-oncogenetic concepts partly derived from the experimental induction of neural tumors.
Abstract: The embryonal central nervous system (CNS) neoplasms are reviewed with special reference to their differentiating potential and in the light of current neuro-oncogenetic concepts partly derived from the experimental induction of neural tumors. The conceptual (and, occasionally, practical) distinction between adult-type and embryonal CNS tumors raises a complex problem, because neoplastic transformation essentially involves replicating stem cells in tissues of renewal and because in the human brain such cells are found mostly in the course of CNS development. A cytogenetic scheme is therefore needed to serve as a frame of reference for a classification of embryonal CNS tumors that will account for the different histological entities documented so far and for the range and the restrictions of their differentiating capabilities. Most embryonal CNS tumors can be fitted into such a scheme. The cerebral medulloepithelioma, the cerebral and cerebellar neuroblastomas, the primitive polar spongioblastoma, and the ependymoblastoma show characteristic morphological features and a correspondingly distinctive cellular differentiating potential. The differentiating capabilities of the cerebellar medulloblastoma, the pineoblastoma, and the retinoblastoma are also distinctive, and are apparently determined by the cytogenesis of the area of the CNS in which the tumors originate. The indiscriminate application of a simplistic concept that would include all the so-called "primitive neuroectodermal tumors" into a single neuroepithelial tumor entity is unlikely to bring further understanding to the problem.
155 citations
TL;DR: Which clinical evaluations, genetic studies, and histopathologic evaluations of retrieved specimens are currently used widely are described and performed to help those caring for patients with retinoblastoma and to aid informed consent.
154 citations
138 citations
TL;DR: To determine the frequency of histopathologic risk factors in a large series of retinoblastomas treated by enucleation on file in the pathology laboratory of a large American eye hospital, assess the relationship between tumor differentiation and age at en nucleation, and investigate the frequency and role of photoreceptor differentiation and the role ofretinoma/retinocytoma as retinOBlastoma precursor are determined.
Abstract: Context.—Certain histopathologic risk factors in enucleated eyes are important indicators for adjuvant chemotherapy in patients with retinoblastoma. Objectives.—To determine the frequency of histopathologic risk factors in a large series of retinoblastomas treated by enucleation on file in the pathology laboratory of a large American eye hospital, assess the relationship between tumor differentiation and age at enucleation, and investigate the frequency of photoreceptor differentiation and the role of retinoma/retinocytoma as retinoblastoma precursor. Design.—Retrospective histopathologic review of 387 eyes with retinoblastoma treated by enucleation including 297 with no prior treatment. Results.—Fifty-five of 297 untreated eyes (18.5%) had high-risk features. Retrolaminar optic nerve invasion was present in 31 (10.4%), and 24 (8.1%) had massive uveal invasion (defined as >3 mm in diameter). Of the high-risk eyes, 70.9% had iris neovascularization and 60% had neovascular glaucoma. There was a sta...
133 citations
References
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[...]
01 Jan 1961
TL;DR: Cilia are motile, hairlike appendages on the free surface of cells that play an important role in such diverse physiological processes as locomotion, alimentation, circulation, respiration, reproduction, and sensory reception.
Abstract: Publisher Summary Cilia and flagella are motile, hairlike appendages on the free surface of cells. Flagella usually have an undulant motion, and cilia have a pendular stroke. Flagella generally beat independently, whereas cilia are coordinated. Cilia are characteristic of a major group of the protozoa and are found in one or more epithelial tissues in animals of nearly every metazoan phylum. Many protozoans, and the spermatozoa of most metazoans, swim by means of flagella. They are also found on a number of fixed-cell types, such as the choanocytes of sponges, the gastroderm cells of coelenterates, and certain cells of the vertebrate nephron. Cilia play an important role in such diverse physiological processes as locomotion, alimentation, circulation, respiration, reproduction, and sensory reception. They are the organs of locomotion not only for unicellular organisms but also for flatworms and even some gastroderms. Sessile protozoans, bryozoans, and mollusks use them to create currents in the surrounding water that sweep food into the oral apparatus. They transport food through the alimentary tract of mollusks and some echinoderms. They have an important protective role in the respiratory tract of mammals, where they continuously eliminate from the body the bacteria and foreign particles inhaled and trapped in the layer of mucus that lines the airway. The ciliated epithelia of the reproductive ducts participate in the transport of the gametes.
332 citations
138 citations
TL;DR: In this paper, the authors present an overview of the evolution of the Retinazelle and its relationship with the rest of the body of work in the field of physicologischen excavations.
Abstract: Inhalt: E i n l e i t u n g S. 419. I. R e t i n a und P i g m e n t e p i t h e l . Bemerkungen fiber Literatur und Konservierung S. 4'20. A. E r s t e E n t w i c k l u n g der R e t i n a und des P i g m e n t e p i t h e l s . a. Reines Epithelstadium der Retina S, 4'24. b, Stadium der Randschleierentwieklung und der ersten Pigmentbildung S. 4~7, c. Die Zellen des Randschleiers S. 436. d Uber die Randschleierentwieklung und die Differeuzierung der Retinazellen. S. 4.~9. B. Die w e i t e r e E n t w i c k l u n g de r R e t i n a a n d des P i g m e n t e p i t h e l s S. 446. a. Die Entwicklung der Ganglienzellenund Nervenfaserschicht S. 446. b. Die Entwicklung der beiden KSrnerschichten sowie der beiden plexiformen Schichten S. 461. c. Die Entwicklung der Area und Fovea centralis retinae S. 466. d. Die Entwieklung der Zapfen und St~bcheu S. 475. e. Uber die Ver~nderungen der Form und GrCisse der Retinazellen und ihre Bedeutung ffir die Dickenzunahme
42 citations