516 research outputs found

    Topical treatment options for conjunctival neoplasms

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    Topical therapies offer a nonsurgical method for treating conjunctival tumors by delivering high drug concentrations to the ocular surface. Over the past ten years, topical agents have been used by investigators to treat various premalignant and malignant lesions of the conjunctiva, such as primary acquired melanosis with atypia, conjunctival melanoma, squamous intraepithelial neoplasia and squamous cell carcinoma of the conjunctiva, and pagetoid spread of the conjunctiva arising from sebaceous cell carcinoma. Despite the enthusiasm generated by the success of these agents, there are unanswered questions regarding the clinical efficacy of this new nonsurgical approach, and whether a single topical agent can achieve cure rates comparable with traditional therapies. Furthermore, the long-term consequences of prolonged courses of topical chemotherapeutic drugs on the ocular surface are unknown, and the ideal regimen for each of these agents is still being refined. In this review, we present specific guidelines for treating both melanocytic and squamous neoplasms of the conjunctiva, utilizing the available data in the literature as well as our own clinical experience at the Memorial Sloan-Kettering Cancer Center

    Rb induces a proliferative arrest and curtails Brn-2 expression in retinoblastoma cells

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    BACKGROUND: Retinoblastoma is caused by loss of the Rb protein in early retinal cells. Although numerous Rb functions have been identified, Rb effects that specifically relate to the suppression of retinoblastoma have not been defined. RESULTS: In this study, we examined the effects of restoring Rb to Y79 retinoblastoma cells, using novel retroviral and lentiviral vectors that co-express green fluorescent protein (GFP). The lentiviral vector permitted transduction with sufficient efficiency to perform biochemical analyses. Wild type Rb (Rb(WT)) and to a lesser extent the low penetrance mutant Rb(661W )induced a G0/G1 arrest associated with induction of p27(KIP1 )and repression of cyclin E1 and cyclin E2. Microarray analyses revealed that in addition to down-regulating E2F-responsive genes, Rb repressed expression of Brn-2 (POU3F2), which is implicated as an important transcriptional regulator in retinal progenitor cells and other neuroendocrine cell types. The repression of Brn-2 was a specific Rb effect, as ectopic p27 induced a G0/G1 block, but enhanced, rather than repressed, Brn-2 expression. CONCLUSION: In addition to Rb effects that occur in many cell types, Rb regulates a gene that selectively governs the behavior of late retinal progenitors and related cells

    The Location and Appearance of Second Malignancies in Patients With Bilateral Retinoblastoma

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    Purpose. This paper describes the clinical history and radiographic appearance of second malignancies in patients with bilateral retinoblastoma

    Multi-objective engineering shape optimization using differential evolution interfaced to the Nimrod/O tool

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    This paper presents an enhancement of the Nimrod/O optimization tool by interfacing DEMO, an external multiobjective optimization algorithm. DEMO is a variant of differential evolution – an algorithm that has attained much popularity in the research community, and this work represents the first time that true multiobjective optimizations have been performed with Nimrod/O. A modification to the DEMO code enables multiple objectives to be evaluated concurrently. With Nimrod/O’s support for parallelism, this can reduce the wall-clock time significantly for compute intensive objective function evaluations. We describe the usage and implementation of the interface and present two optimizations. The first is a two objective mathematical function in which the Pareto front is successfully found after only 30 generations. The second test case is the three-objective shape optimization of a rib-reinforced wall bracket using the Finite Element software, Code_Aster. The interfacing of the already successful packages of Nimrod/O and DEMO yields a solution that we believe can benefit a wide community, both industrial and academic

    The effect of national and constituency level expectations on tactical voting in the British general election of 2010

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    The 2010 elections in the United Kingdom provided voters with numerous and diverse opportunities to reason strategically. The Liberal Democrats (Lib Dems)-traditionally finishing a distant third in terms of seats in Parliament-vied with labour to be the principal competition to the Conservatives, who failed to win a majority of seats, creating a rare case of what the British call a hung parliament. These conditions varied across constituencies at the district level, and we exploit this variation to study the incidence of "tactical" voting. But the national outcome also presented strategic considerations for voters, and the conditions varied to some extent over the course of the campaign, giving voters interviewed at different times different sets of national considerations for tactical voting. This presents us with the opportunity to investigate how both local and national considerations may shape strategic reasoning among voters and relate to each other and to the final choices of voters on Election Day

    Ophthalmic Artery Chemosurgery for Less Advanced Intraocular Retinoblastoma: Five Year Review

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    BACKGROUND: Ophthalmic artery chemosurgery (OAC) for retinoblastoma was introduced by us 5 years ago for advanced intraocular retinoblastoma. Because the success was higher than with existing alternatives and systemic side effects limited we have now treated less advanced intraocular retinoblastoma (Reese-Ellsworth (RE) I-III and International Classification Retinoblastoma (ICRB) B and C). METHODOLOGY/PRINCIPAL FINDINGS: Retrospective review of 5 year experience in eyes with Reese Ellsworth (Table 1) I (7 eyes), II (6 eyes) or III (6 eyes) and/or International Classification (Table 2) B (19 eyes) and C (11 eyes) treated with OAC (melphalan with or without topotecan) introduced directly into the ophthalmic artery. Patient survival was 100%. Ocular event-free survival was 100% for Reese-Ellsworth Groups I, II and III (and 96% for ICRB B and C) at a median of 16 months follow-up. One ICRB Group C (Reese-Ellsworth Vb) eye could not be treated on the second attempt for technical reasons and was therefore enucleated. No patient required a port and only one patient required transfusion of blood products. The electroretinogram (ERG) was unchanged or improved in 14/19 eyes. CONCLUSIONS/SIGNIFICANCE: Ophthalmic artery chemosurgery for retinoblastoma that was Reese-Ellsworth I, II and III (or International Classification B or C) was associated with high success (100% of treatable eyes were retained) and limited toxicity with results that equal or exceed conventional therapy with less toxicity

    Pharmacokinetic analysis of topotecan after superselective ophthalmic artery infusion and periocular administration in a porcine mode

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    Purpose: To characterize the vitreous and plasma pharmacokinetics of topotecan after ophthalmic artery infusion (OAI) subsequent to superselective artery catheterization and to compare it with periocular injection (POI). Methods: The ophthalmic artery of 4 pigs was catheterized and 1 mg of topotecan infused over a period of 30 minutes. The contralateral eye was subsequently used for administering topotecan by POI. Serial vitreous specimens were obtained by microdialysis and plasma samples collected and assayed for total and lactone topotecan. Results: Maximum total topotecan concentration in the vitreous (median, range) was significantly higher after OAI compared with POI (131.8 ng/mL [112.9–138.7] vs. 13.6 ng/mL [5.5–15.3], respectively; P , 0.005). Median vitreous exposure calculated as area under the curve for total topotecan attained after OAI was significantly higher than after POI (299.8 nghour/mL [247.6–347.2] and 48.9 nghour/mL [11.8–63.4], respectively; P , 0.05). The vitreous to plasma exposure ratio was 29 after OAI and 3.4 after POI. Systemic exposure for total topotecan was low after both modalities of administration, with a trend to be lower after OAI compared with POI (10.6 nghour/mL [6.8–13.4] vs. 18.7 nghour/mL [6.3–21.7]; P = 0.54). Conclusion: Superselective OAI resulted in significantly higher vitreous concentrations and exposure and a trend toward lower systemic exposure than POI.Fil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buitrago, Emiliano. Universidad de Buenos Aires; ArgentinaFil: Ceciliano, Alejandro. No especifíca;Fil: Fandino, Adriana C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Asprea, Marcelo. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sierre, Sergio. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Abramson, David H.. No especifíca;Fil: Bramuglia, Guillermo Federico. Universidad de Buenos Aires; ArgentinaFil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentin

    Pharmacokinetic analysis of topotecan after superselective ophthalmic artery infusion and periocular administration in a porcine mode

    Get PDF
    Purpose: To characterize the vitreous and plasma pharmacokinetics of topotecan after ophthalmic artery infusion (OAI) subsequent to superselective artery catheterization and to compare it with periocular injection (POI). Methods: The ophthalmic artery of 4 pigs was catheterized and 1 mg of topotecan infused over a period of 30 minutes. The contralateral eye was subsequently used for administering topotecan by POI. Serial vitreous specimens were obtained by microdialysis and plasma samples collected and assayed for total and lactone topotecan. Results: Maximum total topotecan concentration in the vitreous (median, range) was significantly higher after OAI compared with POI (131.8 ng/mL [112.9–138.7] vs. 13.6 ng/mL [5.5–15.3], respectively; P , 0.005). Median vitreous exposure calculated as area under the curve for total topotecan attained after OAI was significantly higher than after POI (299.8 nghour/mL [247.6–347.2] and 48.9 nghour/mL [11.8–63.4], respectively; P , 0.05). The vitreous to plasma exposure ratio was 29 after OAI and 3.4 after POI. Systemic exposure for total topotecan was low after both modalities of administration, with a trend to be lower after OAI compared with POI (10.6 nghour/mL [6.8–13.4] vs. 18.7 nghour/mL [6.3–21.7]; P = 0.54). Conclusion: Superselective OAI resulted in significantly higher vitreous concentrations and exposure and a trend toward lower systemic exposure than POI.Fil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buitrago, Emiliano. Universidad de Buenos Aires; ArgentinaFil: Ceciliano, Alejandro. No especifíca;Fil: Fandino, Adriana C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Asprea, Marcelo. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sierre, Sergio. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Abramson, David H.. No especifíca;Fil: Bramuglia, Guillermo Federico. Universidad de Buenos Aires; ArgentinaFil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentin

    Tridimensional Retinoblastoma Cultures as Vitreous Seeds Models for Live-Cell Imaging of Chemotherapy Penetration

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    A preclinical model could aid in understanding retinoblastoma vitreous seeds behavior, drug penetration, and response to chemotherapy to optimize patient treatment. Our aim was to develop a tridimensional in vitro model of retinoblastoma vitreous seeds to assess chemotherapy penetration by means of live-cell imaging. Cell cultures from patients with retinoblastoma who underwent upfront enucleation were established and thoroughly characterized for authentication of human tumor origin. The correlation of the in vitro tridimensional structures resembling human spheres and dusts vitreous seeds was established. Confocal microscopy was used to quantify real-time fluorescence of topotecan as a measure of its penetration into different sizes of spheres. Cell viability was determined after chemotherapy penetration. The in vitro spheres and dusts models were able to recapitulate the morphology, phenotype, and genotype of patient vitreous seeds. The larger the size of the spheres, the longer the time required for the drug to fully penetrate into the core (p < 0.05). Importantly, topotecan penetration correlated with its cytotoxic activity. Therefore, the studied tridimensional cell model recapitulated several characteristics of vitreous seeds observed in patients with retinoblastoma and were successfully used to assess live-cell imaging of chemotherapy penetration for drug distribution studies.Fil: Winter, Ursula Andrea. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aschero, María del Rosario. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fuentes, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Buontempo, Fabian. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Zugbi, Santiago. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sgroi, Mariana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sampor, Claudia. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Abramson, David H.. Memorial Sloan-kettering Cancer Center; Estados UnidosFil: Carcaboso, Angel M.. Hospital Sant Joan de Deu Barcelona; EspañaFil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Quantum Nonlocality without Entanglement

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    We exhibit an orthogonal set of product states of two three-state particles that nevertheless cannot be reliably distinguished by a pair of separated observers ignorant of which of the states has been presented to them, even if the observers are allowed any sequence of local operations and classical communication between the separate observers. It is proved that there is a finite gap between the mutual information obtainable by a joint measurement on these states and a measurement in which only local actions are permitted. This result implies the existence of separable superoperators that cannot be implemented locally. A set of states are found involving three two-state particles which also appear to be nonmeasurable locally. These and other multipartite states are classified according to the entropy and entanglement costs of preparing and measuring them by local operations.Comment: 27 pages, Latex, 6 ps figures. To be submitted to Phys. Rev. A. Version 2: 30 pages, many small revisions and extensions, author added. Version 3: Proof in Appendix D corrected, many small changes; final version for Phys. Rev. A Version 4: Report of Popescu conjecture modifie
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