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Schneiderman J, Rubin E, Nugent DJ, Young G. Sequential therapy with activated prothrombin complex concentrates and recombinant FVIIa in patients with severe haemophilia and inhibitors: update of our previous experience. Haemophilia 2007; 13:244-8. [PMID: 17498072 DOI: 10.1111/j.1365-2516.2007.01451.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Haemophilia patients with inhibitors can develop bleeding episodes, which are refractory to monotherapy with either recombinant factor VIIa (rFVIIa) or activated prothrombin complex concentrates (APCC). Management of such bleeds is often difficult. We previously reported the safety of using a combination of rFVIIa and APCC given in sequential fashion. In this report, we update our experience with sequential therapy. A retrospective review of medical records was conducted including all reports of sequential therapy defined as receiving both rFVIIa and APCC within 6 h. Data extracted included demographic data, treatment prior to and following hospital admission, clinical data including type and location of bleed, response to therapy, physical examination and laboratory data. In addition, for some patients, thromboelastography was performed to document the effect of sequential therapy on clot formation characteristics. Four patients comprising 35 admissions, 209 hospital days and 115 days of sequential therapy were included in the updated dataset. No patient developed thrombosis or overt disseminated intravascular coagulation (DIC) although elevations in the D-dimer above 5 microg mL(-1) were noted in 42% of the courses that lasted >3 days. Efficacy is suggested by the fact that patients had resolution of their bleeds after a median of 3 days of sequential therapy after failing to respond to a median of 3 days of monotherapy. Thromboelastography demonstrated an additive effect. Sequential therapy is a safe, potentially efficacious approach in the management of refractory bleeding episodes in patients with haemophilia and inhibitors.
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Karantza-Wadsworth V, Patel S, Jin S, Rubin E, White E. 403 POSTER Cell death pathways as therapeutic targets for cancer. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70408-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Poplin E, Gharibo M, Rodriquez L, Elsayed Y, Wojtowicz M, Gounder M, Lagattuta T, Rubin E, Egorin M. Phase I study of imatinib mesylate and gemcitabine in patients with refractory solid tumor malignancy. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.3100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Rubin E. LAPIS: A TEXT EDITOR AND A SMART PARSER COMBINED. Brief Bioinform 2005. [DOI: 10.1093/bib/6.2.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Benson AIB, Rubin E, Beers S, Mucci-Lorusso P, Vermuelen W, Denis L, Compton L, Pavlov D, Rothenberg ML. Phase I dose escalation and safety study of a semi-solid matrix (SSM) formulation of oral irinotecan and capecitabine tablets in patients with advanced solid tumors. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.2042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Hammond LA, Ruvuna F, Cunningham CC, Ebbinghaus S, Rubin E, Mita A, Hersh E, Eder JP, Weiss J, Rowinsky EK. Phase (Ph) I evaluation of the dolastatin analogue synthadotin (SYN-D; ILX651): Pooled data analysis of three alternate schedules in patients (pts) with advanced solid tumors. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.3068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Bonate P, Ebbinghaus S, Eder JP, Mita A, Rubin E, Cunningham CC, Rowinsky EK, Hersh E, Craig AR, Hammond LA. Pharmacokinetics of synthadotin (ILX651), a novel tubulin polymerization inhibitor, in patients with solid tumors. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.2082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Heeren J, Beisiegel U, Loeffler B, Rubin E, Pennacchio L, Greten H, Merkel M. W13.325 Apolipoprotein A-V accelerates catabolism of triglyceride-rich lipoproteins in vivo. ATHEROSCLEROSIS SUPP 2004. [DOI: 10.1016/s1567-5688(04)90324-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ramaswami A, Rubin E, Bonola S. Non-significance of rhizosphere degradation during phytoremediation of MTBE. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2003; 5:315-331. [PMID: 14750560 DOI: 10.1080/15226510309359040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Methyl tertiary butyl ether (MTBE) is a gasoline additive associated with groundwater pollution at gas station sites. Previous research on poplar trees in hydroponic systems suggests that phytovolatilization is an effective mechanism for phytoremediation of MTBE (Rubin and Ramaswami, 2001), but the potential for microbial degradation of MTBE in the rhizosphere of trees had not been assessed. MTBE had largely been considered recalcitrant to microbial processes, but recent fieldwork suggests rapid biodegradation may occur in certain cases. This paper investigates the potential for rhizosphere degradation of MTBE at time frames relevant for phytoremediation. Three experiments were conducted at different levels of aggregation to examine possible degradation of MTBE by rhizosphere microorganisms that had been acclimated to low levels of MTBE for 6 weeks. MTBE soil die-away studies, conducted with both poplar trees and fescue grass, found no significant differences between MTBE concentration in vegetated and unvegetated soils over a two-week attenuation period. Closed chamber tests comparing hydroponic and rhizospheric poplar tree systems also showed essentially complete recovery of MTBE mass in both systems, suggesting an absence of degradation. Finally, rhizosphere microbes tested in aerated bioreactors were found to be thriving and metabolizing root materials, but did not show measurable degradation of MTBE. In all tests, the MTBE degradation product, Tert Butyl Alcohol (TBA), was not detected. The insignificance of MTBE degradation by rhizosphere microorganisms suggests that plant processes be the primary focus of further research on MTBE phytoremediation.
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Rubin E. 2WS10-1 Comparative analysis to identify functional regions in the genomes of mammals. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90420-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nowak M, Helleboid-Chapman A, Jakel H, Rommens C, Baug E, Gervois P, Vu-Dac N, Martin G, Duran-Sandoval D, Staels B, Taskinen MR, Pennacchio L, Rubin E, Fruchart-Najib J, Fruchart JC. 3P-0834 Transcriptional regulation of the apolipoprotein A5 gene by insulin. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)91052-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Sterescu A, Carceller A, Tapiero B, Rubin E. Sydenham Chorea: A Frequently Spectacular Presentation of Acute Rheumatic Fever in Children. Paediatr Child Health 2002. [DOI: 10.1093/pch/7.suppl_a.37aa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Carceller A, Tapiero B, Rubin E. Acute Rheumatic Fever, 20 Years of Experience in Montreal, Quebec. Paediatr Child Health 2002. [DOI: 10.1093/pch/7.suppl_a.36ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Hait WN, Rubin E, Goodin S. Tubulin targeting agents. CANCER CHEMOTHERAPY AND BIOLOGICAL RESPONSE MODIFIERS 2002; 19:59-83. [PMID: 11686034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Bengtsson H, Calder B, Mian IS, Callow M, Rubin E, Speed TP. Identifying Differentially Expressed Genes in cDNA Microarray Experiments Authors. ACTA ACUST UNITED AC 2001; 2001:vp8. [PMID: 14602959 DOI: 10.1126/sageke.2001.12.vp8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Rubin E, Baider A, Cohen Y. Phytophthora infestans Produces Oospores in Fruits and Seeds of Tomato. PHYTOPATHOLOGY 2001; 91:1074-1080. [PMID: 18943443 DOI: 10.1094/phyto.2001.91.11.1074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Tomato fruits at the mature green stage coinoculated with A1 + A2 sporangia of Phytophthora infestans, the late blight causal fungus, showed abundant oospores in the vascular tissues, pericarp, columella, and placenta. Oospores were also formed on the surface of fruits kept in moisture-saturated atmosphere. Occasionally, oospores were enclosed between the epidermal hairs of the seed coat. In a few seeds, oospores were detected inside the embryo. The data suggest that blighted tomato fruits may carry a large number of oospores, thus making them a threatening source of blight inoculum. Such fruits may also release airborne oosporic inoculum that may introduce recombinant genotypes within a growing season. Although Phytophthora infestans is seedborne in tomato, to our knowledge, this is the first report on the occurrence of oospores in tomato seeds. Whether such tomato seeds produce blighted seedlings remains to be shown.
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Spies CD, Sander M, Stangl K, Fernandez-Sola J, Preedy VR, Rubin E, Andreasson S, Hanna EZ, Kox WJ. Effects of alcohol on the heart. Curr Opin Crit Care 2001; 7:337-43. [PMID: 11805530 DOI: 10.1097/00075198-200110000-00004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Some evidence suggests that light to moderate alcohol consumption protects against cardiovascular diseases. However, this cardioprotective effect of alcohol consumption in adults is absent at the population level. Approximately 20 to 30% of patients admitted to a hospital are alcohol abusers. In medical practice, it is essential that patients' levels of consumption are known because of the many adverse effects that might result in the course of routine care. Ethanol damage to the heart is evident if alcohol consumption exceeds 90 to 100 g/d. Heavy ethanol consumption leads to increased risk for sudden cardiac death and cardiac arrhythmias. In patients with coronary heart disease, alcohol use was associated with increased mortality. An early response to drinking was an increased ventricular wall thickness to diameter ratio, possibly proceeding with continuous drinking to alcoholic cardiomyopathy, which had a worse outcome compared with idiopathic dilative cardiomyopathy if drinking was not stopped or at least reduced (< 60 g/d). In the ICU, patients with chronic alcoholism have more cardiac complications postoperatively. These complications probably are caused by biventricular dysfunction, particularly with the occurrence of severe infections or septic shock, events that are three to four times more frequent among chronic alcoholics than occasional drinkers or nondrinkers. To prevent further complications from drinking and for long-term management of drinking, patients with alcohol abuse and heart failure should be treated in brief intervention and follow-up programs. Prognosis is good even in patients with New York Heart Association class IV heart failure caused by cardiomyopathy if complete abstinence is accomplished. Noncompliance to smoking and alcohol restrictions, which are amenable to change, dramatically increases the risk for hospital readmissions among patients with heart failure.
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Weiss K, de Azavedo J, Restieri C, Quach C, Laverdiere M, Rubin E, Gourdeau M, Low DE. In vitro activity of a novel ketolide ABT-773 against invasive strains of Streptococcus pneumoniae. J Antimicrob Chemother 2001; 48:407-9. [PMID: 11533007 DOI: 10.1093/jac/48.3.407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
New ketolides such as ABT-773 are a promising group of antibiotics in an era of increasing antibiotic resistance. We tested 704 invasive strains of Streptococcus pneumoniae collected from 1990 to 1998. Overall resistance was 8.3, 4.6, 4.5 and 3.6% for penicillin, cefuroxime, erythromycin and clarithromycin, respectively. By using a recommended breakpoint for susceptibility of <0.5 mg/L, no strains showed reduced susceptibility to ABT-773. ABT-773 was very active against all penicillin-resistant strains (MIC > 2 mg/L, with a mean geometric mean <0.06 mg/L), and against all 33 erythromycin-resistant strains, irrespective of the mode of resistance [mef- or erm(B)-mediated]. ABT-773 is a very active and promising agent against invasive strains of S. pneumoniae, including multiresistant strains.
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Qiu Y, Cavelier L, Chiu S, Yang X, Rubin E, Cheng JF. Human and mouse ABCA1 comparative sequencing and transgenesis studies revealing novel regulatory sequences. Genomics 2001; 73:66-76. [PMID: 11352567 DOI: 10.1006/geno.2000.6467] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The expression of ABCA1, a major participant in apolipoprotein-mediated cholesterol efflux, is regulated by a variety of factors, including intracellular cholesterol concentration. To identify sequences involved in its regulation, we sequenced and compared approximately 200 kb of mouse and human DNA containing the ABCA1 gene. Furthermore, expression of the human gene containing different 5' ends was examined in transgenic mice. Sequence comparison revealed multiple conserved noncoding sequences. The two most highly conserved noncoding elements (CNS1, 88% identity over 498 bp; CNS2, 81% identity over 214 bp) were also highly conserved in other organisms. Mice containing the human ABCA1 gene, 70 kb of upstream DNA, and 35 kb of downstream DNA expressed the transgene similarly to endogenous Abca1. A second transgene beginning 3' to exon 1 was expressed only in liver, providing strong evidence of an unsuspected liver-specific promoter. The identified conserved noncoding sequences invite further investigation to elucidate ABCA1 regulation.
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Bokkala S, Reis HM, Rubin E, Joseph SK. Effect of angiotensin II and ethanol on the expression of connexin 43 in WB rat liver epithelial cells. Biochem J 2001; 357:769-77. [PMID: 11463347 PMCID: PMC1222006 DOI: 10.1042/0264-6021:3570769] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The turnover of connexin 43 (Cx43) is very rapid in many cells and involves both the lysosomal and proteasomal protease pathways. Here we show that Ca(2+)-mobilizing agonists such as angiotensin II (Ang II) can up-regulate the expression of Cx43 in WB rat liver epithelial cells. Vasopressin had the same effect in A7R5 smooth-muscle cells. The effect of Ang II was not prevented by pretreatment with proteasomal or lysosomal inhibitors and was associated with an enhanced biosynthesis of Cx43 as measured by metabolic labelling experiments. The accumulation of Cx43 occurred in intracellular compartments and at the cell surface, as determined by confocal immunofluorescence studies and by immunoblotting of fractions soluble and insoluble in Triton X-100. Chronic treatment of WB cells with ethanol inhibited Cx43 expression; this was associated with decreased biosynthesis of Cx43. Neither treatment with Ang II nor treatment with ethanol altered the levels of Cx43 mRNA. Incubation of WB cells with Ang II did not alter gap-junctional communication as judged by a dye-coupling assay. However, treatment with ethanol markedly decreased gap-junctional communication and this effect was diminished in Ang-II-treated cells, demonstrating that gap-junctional communication is linked to the level of Cx43 expression. We conclude that Cx43 biosynthesis is regulated by Ca(2+)-mobilizing agonists and ethanol in WB cells. The changes in Cx43 expression might have a role in modifying the conduction of metabolites and second messengers between cells.
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Elkind JS, Rubin E, Rosenthal S, Skoff B, Prather P. A simulated reality scenario compared with the computerized Wisconsin card sorting test: an analysis of preliminary results. CYBERPSYCHOLOGY & BEHAVIOR : THE IMPACT OF THE INTERNET, MULTIMEDIA AND VIRTUAL REALITY ON BEHAVIOR AND SOCIETY 2001; 4:489-96. [PMID: 11708728 DOI: 10.1089/109493101750527042] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Neuropsychologists and other clinicians often comment on the minimal relationship that frequently exists between formal assessments of executive functions, analysis of findings, recommendations, and the person's real-life functioning. The authors' believe that current assessments of executive functions do not transfer easily to real-world behavior. There are limitations in the current examinations and in the settings in which they are given. The tests are artificial and the test settings lack the usual stresses, distractions, and multiple demands common to real life. The interactions are unlike what they experience in everyday life. The examiner often, but unintentionally orients the participant to relevant information that in turn can help the person compensate for the difficulties with executive control processes and bias the findings. We believe that virtual reality (VR) more closely approximates real life settings, the distractions, and the common interchanges (VR) provides a "life-like," three-dimensional (3-D) highly interactive environment, and safety from potential dangers that could arise in actual situations. VR can increase motivation because of its gaming, interactive, and immersive qualities and features are easily modified and allow for multiple applications. Our goal is to develop VR assessments that can be administered under controlled and safe conditions, but which are more sensitive to difficulties with executive control processes critical to safe, independent living. This initial study compares several functions assessed by the Wisconsin Card Sorting Test (WCST) with our three-dimensional, stereographic scenario, Look for a Match (LFAM) Study participants completed questionnaires, alternately began with either the WCST or LFAM, and then took the second test. All participants completed motion sickness and follow-up questionnaires. The results demonstrated that the study participants found LFAM to be more enjoyable and interesting, but found the WCST to be easier. While there is an effect of order with participants doing relatively better on the assessment tool administered second, overall the LFAM performance was inferior to that on the WCST. However, even considering the order effect, LFAM seemed to be more difficult than the WCST.
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Abstract
The maize transposon Activator (Ac) was the first mobile DNA element to be discovered. Since then, other elements were found that share similarity to Ac, suggesting that it belongs to a transposon superfamily named hAT after hobo from Drosophila, Ac from maize, and Tam3 from snapdragon. We addressed the structure and evolution of hAT elements by developing new tools for transposon mining and searching the public sequence databases for the hallmarks of hAT elements, namely the transposase and short terminal inverted repeats (TIRs) flanked by 8-bp host duplications. We found 147 hAT-related sequences in plants, animals, and fungi. Six conserved blocks could be identified in the transposase of most hAT elements. A total of 41 hAT sequences were flanked by TIRs and 8-bp host duplications and, out of these, 34 sequences had TIRs similar to the consensus determined in this work, suggesting that they are active or recently active transposons. Phylogenetic analysis and clustering of hAT sequences suggest that the hAT superfamily is very ancient, probably predating the plant-fungi-animal separation, and that, unlike previously proposed, there is no evidence that horizontal gene transfer was involved in the evolution of hAT elements.
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Rubin E, Mittnacht S, Villa-Moruzzi E, Ludlow JW. Site-specific and temporally-regulated retinoblastoma protein dephosphorylation by protein phosphatase type 1. Oncogene 2001; 20:3776-85. [PMID: 11439341 DOI: 10.1038/sj.onc.1204518] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2001] [Revised: 04/03/2001] [Accepted: 04/09/2001] [Indexed: 12/27/2022]
Abstract
pRb is dephosphorylated at mitotic exit by the type 1 serine/threonine protein phosphatases (PP1). Here we demonstrate for the first time that mitotic pRb dephosphorylation is a sequential, temporally-regulated event. We also provide evidence that the three mammalian isoforms of PP1, alpha, gamma-1, and delta, differ in their respective preferences for site-specific pRb dephosphorylation and that the mitotic and G(1) PP1-isoform counterparts exhibit differential activities towards mitotic pRb. Finally, the physiological relevance of the striking contrast between the patterns of Thr821 and Thr826 dephosphorylation, sites known to be important for disrupting binding of LXCXE-containing proteins to pRb, is addressed.
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Levin A, Baider A, Rubin E, Gisi U, Cohen Y. Oospore Formation by Phytophthora infestans in Potato Tubers. PHYTOPATHOLOGY 2001; 91:579-585. [PMID: 18943947 DOI: 10.1094/phyto.2001.91.6.579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT The ability of Phytophthora infestans, the causal agent of potato and tomato late blight, to produce oospores in potato tuber tissue was studied in the field and under laboratory conditions. In 1998 and 2000 field experiments, the canopy of potato cvs. Alpha and Mondial, respectively, were coinoculated with A1 + A2 sporangia of the fungus, and the infected tubers collected at harvest were examined for the presence of oospores. In 1998, only 2 of 90 infected tubers had oospores, whereas none of the 90 tubers examined in 2000 had any oospores. In the latter experiment, infected tubers kept in storage up to 12 weeks after harvest had no oospores. Artificial co-inoculations of whole tubers with A1 + A2 sporangia resulted only rarely in the formation of oospores inside the tubers. Co-inoculations of potato tuber discs taken from dormant tubers 0 to 16 weeks after harvest failed to support any oospore production, whereas discs taken from sprouting tubers of >/=18 weeks after harvest allowed oospores to form. Tuber discs showed enhanced oospore formation when treated before inoculation with either sugars, amino acids, casein hydrolysate, beta-sitosterol, or chloroethylphosphonic acid. In contrast, reducing airflow into the petri dishes where potato tuber discs were incubated reduced the number of oospores produced. The number of oospores produced in tuber tissue was lower compared with that in leaf tissue regardless of the origin of isolates used. The data show that the ability of Phytophthora infestans to produce oospores in potato tuber tissue is very limited and increases with tuber aging.
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Abstract
This paper examines the potential for phytoremediation of MTBE, a gasoline additive that has become a prevalent and persistent groundwater pollutant, due to its' non-sorbing and non-reactive nature in water. A novel experimental design is developed to measure plant uptake and transpiration of MTBE from hydroponic systems, separating these processes from passive volatilization of the chemical. Plant uptake experiments indicate 30% reduction in MTBE mass in water over a 1-week period by small poplar saplings, at both high (1600 ppb) and low (300 ppb) MTBE concentrations. Active plant uptake of MTBE was approximately double that achieved by passive volatilization through a balsa wood control. MTBE was detected in biomass at the 100-ppb level, confirming passage of MTBE through the plant. A mass balance indicated that MTBE was largely untransformed during transport through the small poplar saplings to air. The high degree of MTBE removal achieved by small plants over a short period of time indicates great potential for successful phytoremediation of subsurface MTBE plumes using poplar trees. The fraction of MTBE removed from the hydroponic systems correlated well with volume of water transpired by the plants; the correlation enabled computation of the MTBE transpiration stream concentration factor of approximately 1, an important parameter for the design of engineered MTBE phytoremediation systems.
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