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Selective Elimination (selective + elimination)
Selected AbstractsConversion of 3-O-Substituted 1,2-Dibromoalkanes into 2-Bromo-1-alkenes by the Selective Elimination: Its Application to Total Synthesis of 12-Oxygenated Tremetones.CHEMINFORM, Issue 5 2005Tadaaki Ohgiya Abstract For Abstract see ChemInform Abstract in Full Text. [source] Selective elimination of amplified CDK4 sequences correlates with spontaneous adipocytic differentiation in liposarcomaGENES, CHROMOSOMES AND CANCER, Issue 11 2009Zofia Hélias-Rodzewicz Well-differentiated and undifferentiated liposarcomas are characterized by high-level amplifications of chromosome 12 regions including the CDK4 and MDM2 genes. These amplicons are either localized, in well-differentiated liposarcoma (WDLPS), on extrachromosomal structures (ring or rod chromosomes), or integrated into chromosome arms in undifferentiated tumors. Our results reveal that extrachromosomal amplicons are unstable, and frequently lost by micronucleation. This loss correlates with hypermethylation of eliminated sequences and changes of their replication time. Treatment of cells with demethylating agents during early S-phase significantly decreases the rate of micronuclei positive for CDK4. We also demonstrate that, in our model, micronuclei are generated during anaphase as a consequence of anaphase abnormalities (chromosome lagging and anaphase bridges). Finally, a dramatic increase of adipocytic differentiation was noted in cells that have eliminated copies of CDK4 gene in micronuclei. These findings provide evidence that, in WDLPS, adipocytic differentiation could be the consequence of CDK4 loss, an event occurring rarely in undifferentiated tumors in which the amplified sequences are integrated into chromosome arms. © 2009 Wiley-Liss, Inc. [source] Insect antifeedant and growth regulating activities of neem seed oil , the role of major tetranortriterpenoidsJOURNAL OF APPLIED ENTOMOLOGY, Issue 7-8 2000T. R. Govindachari Selective elimination of triterpenoids by preparative high-performance liquid chromatography, incorporation of the eliminated compounds in defined concentrations and bioassaying the resultant fractions against Spodoptera litura indicated the necessity to quantify major triterpenoids for correlation of bioactivity of neem oil. [source] Selective elimination of hepatic natural killer T cells with Concanavalin A improves liver regeneration in miceLIVER INTERNATIONAL, Issue 3 2006Wen Huang Abstract: Background: Although concanavalin A (Con A) as a T cell stimulant can cause natural killer T (NKT) cell-mediated liver injury in mice and a nonhepatotoxic dose of Con A can trigger innate immune cells including NKT cells to prevent tumor metastasis in the liver, little is known about the role of Con A-primed NKT cells in liver repair. In this study, we aimed to investigate the effect of pretreatment with a nontoxic dose of Con A on subsequent liver regeneration in mice. Methods: A nontoxic dose of Con A was injected intravenously 24 h before partial hepatectomy (PHx), which was used as a model of liver regeneration. Ratios of remnant liver mass to body weight, bromodeoxyuridine (BrdU) incorporation and proliferating cell nuclear antigen (PCNA) labeling were used to assess liver regeneration. Results: Hepatic mononuclear cells were isolated and analyzed by flow cytometry. After PHx, the ratios of liver weight to body weight, PCNA-positive hepatocytes and BrdU-positive hepatocytes in Con A-pretreated mice were significantly higher than that of phosphate-buffered saline-treated mice, indicating that Con A pretreatment can accelerate liver regeneration. Flow cytometric analysis showed that NKT cells were significantly activated and selectively eliminated after the Con A administration. Moreover, NKT cells expressed more apoptosis-related molecules, Fas and Annexin V. Conclusions: Taken together, Con A accelerates liver regeneration in mice by eliminating hepatic NKT cells via activation-induced cell death. [source] Analysis of Atrioventricular Nodal Reentrant Tachycardia with Variable Ventriculoatrial Block: Characteristics of the Upper Common PathwayPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2009KENJI MORIHISA M.D. Background: The precise nature of the upper turnaround part of atrioventricular nodal reentrant tachycardia (AVNRT) is not entirely understood. Methods: In nine patients with AVNRT accompanied by variable ventriculoatrial (VA) conduction block, we examined the electrophysiologic characteristics of its upper common pathway. Results: Tachycardia was induced by atrial burst and/or extrastimulus followed by atrial-His jump, and the earliest atrial electrogram was observed at the His bundle site in all patients. Twelve incidents of VA block: Wenckebach VA block (n = 7), 2:1 VA block (n = 4), and intermittent (n = 1) were observed. In two of seven Wenckebach VA block, the retrograde earliest atrial activation site shifted from the His bundle site to coronary sinus ostium just before VA block. Prolongation of His-His interval occurred during VA block in 11 of 12 incidents. After isoproterenol administration, 1:1 VA conduction resumed in all patients. Catheter ablation at the right inferoparaseptum eliminated antegrade slow pathway conduction and rendered AVNRT noninducible in all patients. Conclusion: Selective elimination of the slow pathway conduction at the inferoparaseptal right atrium may suggest that the subatrial tissue linking the retrograde fast and antegrade slow pathways forms the upper common pathway in AVNRT with VA block. [source] Selective elimination of synovial inflammatory macrophages in rheumatoid arthritis by an Fc, receptor I,directed immunotoxinARTHRITIS & RHEUMATISM, Issue 5 2003Joel A. G. Van Roon Objective To determine whether monocyte/macrophages from rheumatoid arthritis (RA) patients can be selectively eliminated by a toxin-conjugated antibody CD64,ricin A (CD64-RiA) directed toward the high-affinity receptor for IgG (Fc,RI), exploiting the capacity of Fc,RI to efficiently endocytose antibody which it has bound. Methods Mononuclear cells from peripheral blood (PB) and synovial fluid (SF) obtained from RA patients were cultured in the presence of CD64-RiA. Cell death of monocyte/macrophages was measured by phenotypic changes (light-scatter patterns and CD14 and Fc,RI expression) and apoptosis (nuclear DNA fragmentation). We then tested whether CD64-RiA,induced cell death of macrophages affected their capacity to stimulate antigen-induced lymphocyte proliferation and to secrete cytokines. Additionally, the capacity of CD64-RiA to inhibit proinflammatory activity and cartilage degradation by RA synovial tissue explants was evaluated. Results Inflammatory macrophages from RA SF expressed elevated levels of Fc,RI and were selectively eliminated by CD64-RiA via apoptotic cell death. Monocyte/macrophages from RA PB, which had lower levels of Fc,RI expression, were much less affected. Induction of SF macrophage apoptosis was associated with efficient inhibition of antigen-induced lymphocyte proliferation and a reduction in tumor necrosis factor , (TNF,) release. Consistent with these effects on SF macrophages, CD64-RiA also inhibited TNF, production, interleukin-1, production, and cartilage-degrading activity of RA synovial tissue explants. Conclusion Together, these data underscore the crucial role of synovial macrophages in RA joint inflammation and indicate that selective elimination of these cells through Fc,RI-directed immunotoxins could be a novel approach to the treatment of RA. [source] Novel strategies targeting pathogen transmission reduction in insect vectors: Tsetse-transmitted trypanosomiasis controlENTOMOLOGICAL RESEARCH, Issue 4 2007Brian L. WEISS Abstract Insect vectors are essential for the transmission of important human diseases such as malaria, leishmaniasis, Chagas and sleeping sickness. Insects are also responsible for the transmission of agricultural diseases that affect livestock and crops. Traditionally, control of the vector populations has been an effective disease management strategy. Recently, vector control strategies have been fortified by research in insect biology and in insect,pathogen interactions as well as by the development of transgenic technologies. In addition to insect population reduction methods, disease control via selective elimination of pathogens in insects can now be explored. Here we explore the tsetse vectors of African trypanosomes and describe the application of recent knowledge gained in their symbiotic, reproductive and vectorial biology to develop novel disease control strategies. [source] Capsaicin-sensitive sensory fibers in the islets of Langerhans contribute to defective insulin secretion in Zucker diabetic rat, an animal model for some aspects of human type 2 diabetesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2007Dorte X. Gram Abstract The system that regulates insulin secretion from ,-cells in the islet of Langerhans has a capsaicin-sensitive inhibitory component. As calcitonin gene-related peptide (CGRP)-expressing primary sensory fibers innervate the islets, and a major proportion of the CGRP-containing primary sensory neurons is sensitive to capsaicin, the islet-innervating sensory fibers may represent the capsaicin-sensitive inhibitory component. Here, we examined the expression of the capsaicin receptor, vanilloid type 1 transient receptor potential receptor (TRPV1) in CGRP-expressing fibers in the pancreatic islets, and the effect of selective elimination of capsaicin-sensitive primary afferents on the decline of glucose homeostasis and insulin secretion in Zucker diabetic fatty (ZDF) rats, which are used to study various aspects of human type 2 diabetes mellitus. We found that CGRP-expressing fibers in the pancreatic islets also express TRPV1. Furthermore, we also found that systemic capsaicin application before the development of hyperglycemia prevents the increase of fasting, non-fasting, and mean 24-h plasma glucose levels, and the deterioration of glucose tolerance assessed on the fifth week following the injection. These effects were accompanied by enhanced insulin secretion and a virtually complete loss of CGRP- and TRPV1-coexpressing islet-innervating fibers. These data indicate that CGRP-containing fibers in the islets are capsaicin sensitive, and that elimination of these fibers contributes to the prevention of the deterioration of glucose homeostasis through increased insulin secretion in ZDF rats. Based on these data we propose that the activity of islet-innervating capsaicin-sensitive fibers may have a role in the development of reduced insulin secretion in human type 2 diabetes mellitus. [source] Nonselective DNA damage induced by a replication inhibitor results in the selective elimination of extrachromosomal double minutes from human cancer cellsGENES, CHROMOSOMES AND CANCER, Issue 10 2007Noriaki Shimizu Gene amplification plays a pivotal role in human malignancy. Highly amplified genes frequently localize to extrachromosomal double minutes (dmin), which usually segregate to daughter cells in association with mitotic chromosomes. We and others had shown that treatment with low-dose hydroxyurea (HU) results in the elimination of dmin and reversion of the cancer cell phenotype. HU treatment in early S-phase, when dmin are replicated, results in their detachment from chromosomes at the next M-phase, leading to the appearance of micronuclei enriched in dmin, followed by their elimination. In this article, we examined the effect of low-dose HU on the behavior of dmin in relation to DNA damage induction by simultaneously monitoring LacO-tagged dmin and phosphorylated histone H2AX (,H2AX). As expected, treatment with low-dose HU induced numerous ,H2AX foci throughout the nucleus in early S-phase, and these rarely coincided with dmin. Most chromosomal ,H2AX foci disappeared by metaphase, whereas, unexpectedly, those that persisted frequently associated with dmin. We found that these dmin aggregated, detached from anaphase chromosomes, and apparently formed micronuclei. Because ,H2AX foci likely represent DNA double strand breaks (DSBs), the response to DSBs sustained by extrachromosomal dmin appears to be different from that sustained by chromosomal loci, which may explain why DSB-inducing agents cause the selective elimination of dmin. © 2007 Wiley-Liss, Inc. [source] Ozonation of vinasse in acid and alkaline mediaJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2003MA Martín Santos Abstract The production of ethanol by fermentation and subsequent distillation generates wastewater known as ,vinasse'. This waste is highly polluting on account of its high organic load and antibacterial activity,which arises from the presence of phenolic compounds that reduce the efficiency of the detoxification treatments best suited to this type of waste (eg anaerobic digestion). This can be avoided by using a pre-treatment based on a chemical oxidant (ozone) at an acid or alkaline pH. Ozonation in acid media provides more selective elimination of phenolic compounds and a more readily biodegradable waste (ie an increased BOD5/COD ratio). Copyright © 2003 Society of Chemical Industry [source] Kin structure and queen execution in the Argentine ant Linepithema humileJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2001M. Reuter Every spring, workers of the Argentine Ant Linepithema humile kill a large proportion of queens within their nests. Although this behaviour inflicts a high energetic cost on the colonies, its biological significance has remained elusive so far. An earlier study showed that the probability of a queen being executed is not related to her weight, fecundity, or age. Here we test the hypothesis that workers collectively eliminate queens to which they are less related, thereby increasing their inclusive fitness. We found no evidence for this hypothesis. Workers of a nest were on average not significantly less related to executed queens than to surviving ones. Moreover, a population genetic analysis revealed that workers were not genetically differentiated between nests. This means that workers of a given nest are equally related to any queen in the population and that there can be no increase in average worker,queen relatedness by selective elimination of queens. Finally, our genetic analyses also showed that, in contrast to workers, queens were significantly genetically differentiated between nests and that there was significant isolation by distance for queens. [source] DISAPPEARANCE OF MALE MITOCHONDRIAL DNA AFTER THE FOUR-CELL STAGE IN SPOROPHYTES OF THE ISOGAMOUS BROWN ALGA SCYTOSIPHON LOMENTARIA (SCYTOSIPHONACEAE, PHAEOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 1 2010Kei Kimura Mitochondrial DNA (mtDNA) of the isogamous brown alga Scytosiphon lomentaria (Lyngb.) Link is inherited maternally. We used molecular biological and morphological analyses to investigate the fate of male mitochondria. Ultrastructural observations showed that the number of 25 mitochondria in a zygote coincided with the number of mitochondria derived from male and female gametes. This number remained almost constant during the first cell division. Strain-specific PCR in single germlings suggested that mtDNA derived from the female gamete remained in the germling during development, while the male mtDNA gradually and selectively disappeared after the four-cell stage. One week after fertilization, male mtDNA had disappeared in sporophytic cells. Using bisulfite DNA modification and methylation mapping assays, we found that the degree of methylation on three analyzed sites of mtDNA was not different between male and female gametes, suggesting that maternal inheritance of mtDNA is not defined by its methylation. This study indicates that the mechanism of selective elimination of male mtDNA is present in each cell of a four-celled sporophyte and that it does not depend on different degrees of DNA methylation between male and female mtDNA. [source] Selective elimination of synovial inflammatory macrophages in rheumatoid arthritis by an Fc, receptor I,directed immunotoxinARTHRITIS & RHEUMATISM, Issue 5 2003Joel A. G. Van Roon Objective To determine whether monocyte/macrophages from rheumatoid arthritis (RA) patients can be selectively eliminated by a toxin-conjugated antibody CD64,ricin A (CD64-RiA) directed toward the high-affinity receptor for IgG (Fc,RI), exploiting the capacity of Fc,RI to efficiently endocytose antibody which it has bound. Methods Mononuclear cells from peripheral blood (PB) and synovial fluid (SF) obtained from RA patients were cultured in the presence of CD64-RiA. Cell death of monocyte/macrophages was measured by phenotypic changes (light-scatter patterns and CD14 and Fc,RI expression) and apoptosis (nuclear DNA fragmentation). We then tested whether CD64-RiA,induced cell death of macrophages affected their capacity to stimulate antigen-induced lymphocyte proliferation and to secrete cytokines. Additionally, the capacity of CD64-RiA to inhibit proinflammatory activity and cartilage degradation by RA synovial tissue explants was evaluated. Results Inflammatory macrophages from RA SF expressed elevated levels of Fc,RI and were selectively eliminated by CD64-RiA via apoptotic cell death. Monocyte/macrophages from RA PB, which had lower levels of Fc,RI expression, were much less affected. Induction of SF macrophage apoptosis was associated with efficient inhibition of antigen-induced lymphocyte proliferation and a reduction in tumor necrosis factor , (TNF,) release. Consistent with these effects on SF macrophages, CD64-RiA also inhibited TNF, production, interleukin-1, production, and cartilage-degrading activity of RA synovial tissue explants. Conclusion Together, these data underscore the crucial role of synovial macrophages in RA joint inflammation and indicate that selective elimination of these cells through Fc,RI-directed immunotoxins could be a novel approach to the treatment of RA. [source] | ||||||||||||||||