bluuebunny/crossref_metadata_2025_split huggingface dataset:
MMC‐related duodenojejunal antegrade and retrograde peristalsis in humans
Authors: BIORNSSON E. , ABRAHAMSSON H. 
Published: August 2010

Abstract According to recent manometric studies the last part of phase III of the migrating motor complex (MMC) shows the features of a retroperistaltic pump in the proximal duodenum in most healthy humans. In the present study, individual contractions in phase II and phase III of the MMC were investigated in ten healthy subjects (four males, six females), focusing on the distal duodenum and the jejunum. Motility was recorded on two different days with eight‐channel catheters. On one day a standard antroduodenojejunal fasting recording was performed for 5 h, allowing detailed analysis of pressure waves in the proximal duodenum. On another day a two‐station measurement was performed in the proximal jejunum and the distal duodenum. The propagated pressure waves were analysed for late phase II (last 30 min) and for the first and the last part (I min) of phase III in the three intestinal segments. Antegrade peristalsis predominated at all levels in phase II and in the first part of phase III. In contrast, 84 ± 11% of all propagated contractions were retrograde in the last part of phase III in the proximal duodenum and 75 ± 16% in the distal duodenum. The proportions of retrograde contractions in early phase III and in late phase III differed significantly, from 11 ± 11% to 84 ± 11% and from 32 ± 16% to 75 ± 16% in the proximal and distal duodenum, respectively (P < 0.01 and P < 0.05). In the proximal jejunum such retroperistalsis was not observed, neither in the beginning nor at the end of phase III. In phase II the proportions of retrograde pressure waves were small (3–10%) in the three segments studied. The migration velocity of the pressure waves showed a gradient in this phase, with the lowest values in the jejunum.It is concluded that the last part of phase III shows the pressure pattern of a retroperistaltic pump through out the duodenum. In contrast, no distinct MMC‐related retroperistalsis was observed in the jejunum.
Uncovering the complex relationship between pre‐eclampsia, preterm birth and cerebral palsy
Authors: Mann Joshua R. , McDermott Suzanne , Griffith Margaret I. , Hardin James , Gregg Anthony 
Published: August 2010

SummaryMann JR, McDermott S, Griffith MI, Hardin J, Gregg A. Uncovering the complex relationship between pre‐eclampsia, preterm birth and cerebral palsy. Paediatric and Perinatal Epidemiology 2010.Pre‐eclampsia is a leading cause of preterm birth, which is strongly associated with cerebral palsy (CP). However, there is controversy about whether pre‐eclampsia is associated with increased risk of CP. We evaluated the association between pre‐eclampsia and CP in 122 476 mother–child pairs insured by the South Carolina Medicaid programme, with births between 1996 and 2002. Prenatal billing records were linked to the children's Medicaid billing records after birth until December 2008. The odds of CP were modelled using logistic regression with generalised estimating equations.There were 337 children (0.28%) diagnosed with CP by at least two different health care providers, and 4226 (3.5%) women were diagnosed with pre‐eclampsia at least twice during pregnancy. Children whose mothers had pre‐eclampsia were almost twice as likely to have CP compared with children of mothers without pre‐eclampsia [odds ratio (OR) = 1.94, 95% confidence interval (CI) 1.25, 2.97]. The association was only significant for pre‐eclampsia diagnosed prior to 37 weeks' gestation. Full term (gestational age ≥37 weeks) infants whose mothers were diagnosed with pre‐eclampsia prior to 37 weeks had increased odds of CP compared with full term children whose mothers did not have pre‐eclampsia (OR = 3.41, 95% CI 1.40, 8.31). Preterm infants whose mothers had pre‐eclampsia were at significantly increased risk of CP compared with full term infants whose mothers did not have pre‐eclampsia (OR = 5.88, 95% CI 3.40, 10.17). The greatest risk for CP was in preterm infants whose mothers did not have pre‐eclampsia (OR = 8.12, 95% CI 6.49, 10.17 compared with full term infants without exposure to pre‐eclampsia). We conclude that pre‐eclampsia with onset before 37 weeks' gestation is a significant risk factor for CP. Some of the association is probably attributable to high risk of preterm birth because of early pre‐eclampsia, while a ‘direct’ effect of pre‐eclampsia on fetal brain development also seems likely.
The record of tidal cycles in mixed silici–bioclastic deposits: examples from small Plio–Pleistocene peripheral basins of the microtidal Central Mediterranean Sea
Authors: LONGHITANO SERGIO G. 
Published: August 2010

AbstractThe Pliocene–Pleistocene peripheral marine basins of the Mediterranean Sea in southern Italy, from Basilicata and western Calabria to northern and eastern Sicily, represent tectonically formed coastal embayments and narrow straits. Here, units of cross‐stratified, mixed silici–bioclastic sand, 25 to 80 m thick, record strong tidal currents. The Central Mediterranean Sea has had a microtidal range of ca 35 cm, and the local amplification of the tidal wave is attributed to tides enhanced in some of the bays and to the out‐of‐phase reversal of the tidal prism in narrow straits linking the Tyrrhenian and Ionian basins. The siliciclastic sediment was generated by local bedrock erosion, whereas the bioclastic sediment was derived from the contemporaneous, foramol‐type cool‐water carbonate factories. The cross‐strata sets represent small to medium‐sized (10 to 60 cm thick) two‐dimensional dunes with mainly unidirectional foreset dip directions. These tidalites differ from the classical tidal rhythmites deposited in mud‐bearing siliciclastic environments. Firstly, the foreset strata lack mud drapes and, instead, show segregation of siliciclastic and bioclastic sand into alternating strata. Secondly, the thickness variation of the successive silici–bioclastic strata couplets, measured over accretion intervals of 2 to 3 m and analysed statistically, reveal only the shortest‐term, diurnal and semi‐diurnal tidal cycles. Thirdly, the record of diurnal and semi‐diurnal tidal cycles is included within the pattern of neap‐spring cycles. Differences between these sediments and classical tidal rhythmites are attributed to the specific palaeogeographic setting of a microtidal sea, with the tidal currents locally enhanced in peripheral basins. It is suggested that this particular facies of mud‐free, silici–bioclastic arenite rhythmites in the stratigraphic record might indicate a specific type of depositional sub‐tidal environment of straits and embayments and the shortest‐term tidal cycles.
A novel aldose/aldehyde reductase protects transgenic plants against lipid peroxidation under chemical and drought stresses
Authors: Oberschall Attila , Deák Mária , Török Katalin , Sass László , Vass Imre , Kovács Izabella , Fehér Attila , Dudits Dénes , Horváth Gábor V. 
Published: August 2010

SummaryRapid accumulation of toxic products from reactions of reactive oxygen species (ROS) with lipids and proteins significantly contributes to the damage of crop plants under biotic and abiotic stresses. Here we have identified a stress‐activated alfalfa gene encoding a novel plant NADPH‐dependent aldose/aldehyde reductase that also exhibited characteristics of the homologous human enzyme. The recombinant alfalfa enzyme is active on 4‐hydroxynon‐2‐enal, a known cytotoxic lipid peroxide degradation product. Ectopic synthesis of this enzyme in transgenic tobacco plants provided considerable tolerance against oxidative damage caused by paraquat and heavy metal treatment. These transformants could also resist a long period of water deficiency and exhibited improved recovery after rehydration. We found a reduced production of lipid peroxidation‐derived reactive aldehydes in these transformed plants under different stresses. These studies reveal a new and efficient detoxification pathway in plants.
Fatty acid ketodienes and fatty acid ketotrienes: Michael addition acceptors that accumulate in wounded and diseased Arabidopsis leaves
Authors: Vollenweider Sabine , Weber Hans , Stolz Stephanie , Chételat Aurore , Farmer Edward E. 
Published: August 2010

SummaryPhysical damage and disease are known to lead to changes in the oxylipin signature of plants. We searched for oxylipins produced in response to both wounding and pathogenesis in Arabidopsis leaves. Linoleic acid 9‐ and 13‐ketodienes (KODEs) were found to accumulate in wounded leaves as well as in leaves infected with the pathogen Pseudomonas syringae pv. tomato (Pst). Quantification of the compounds showed that they accumulated to higher levels during the hypersensitive response to Pst avrRpm1 than during infection with a Pst strain lacking an avirulence gene. KODEs are Michael addition acceptors, containing a chemically reactive α,β‐unsaturated carbonyl group. When infiltrated into leaves, KODEs were found to induce expression of the GST1 gene, but vital staining indicated that these compounds also damaged plant cells. Several molecules typical of lipid oxidation, including malonaldehyde, also contain the α,β‐unsaturated carbonyl reactivity feature, and, when delivered in a volatile form, powerfully induced the expression of GST1. The results draw attention to the potential physiological importance of naturally occurring Michael addition acceptors in plants. In particular, these compounds could act directly, or indirectly via cell damage, as powerful gene activators and might also contribute to host cell death.
Widely separated multiple transgene integration sites in wheat chromosomes are brought together at interphase
Authors: Abranches Rita , Santos Ana P. , Wegel Eva , Williams Sarah , Castilho Alexandra , Christou Paul , Shaw Peter , Stoger Eva 
Published: August 2010

SummaryWe have investigated the organization of transgenes delivered by particle bombardment into the wheat genome, combining conventional molecular analysis with fluorescence in situ hybridization (FISH) and three‐dimensional confocal microscopy. We selected a representative population of transformed wheat lines and carried out molecular and expression analysis. FISH on metaphase chromosomes showed that transgene integration sites were often separated by considerable lengths of genomic DNA (>1 Mbp), or could even be on opposite chromosome arms. Plants showing multiple integration sites on a single chromosome were selected for three‐dimensional confocal analysis of interphase nuclei in root and embryo tissue sections. Confocal microscopy revealed that these sites lay in close physical proximity in the interphase nuclei. Our results clearly show that multiple transgenes physically separated by large intervening regions of endogenous DNA at metaphase can be brought together at interphase. This may reflect the original physical organization of the endogenous DNA at the moment of transformation, with DNA strand breaks introduced into several co‐localized DNA loops by the intruding gold particles. Alternatively, the transgenes may be brought together after transformation, either by an ectopic homologous pairing mechanism, or by recruitment to a common transcription site.
Auxin induces mitogenic activated protein kinase (MAPK) activation in roots of Arabidopsis seedlings
Authors: Mockaitis Keithanne , Howell Stephen H. 
Published: August 2010

SummaryGenome analyses have shown that plants contain gene families encoding various components of mitogen‐activated protein kinase (MAPK) signaling pathways. Previous reports have described the involvement of MAPK pathways in stress and pathogen responses of leaves and suspension‐cultured cells. Here we show that auxin treatment of Arabidopsis roots transiently induced increases in protein kinase activity with characteristics of mammalian ERK‐like MAPKs. The MAPK response we monitored was the result of hormonal action of biologically active auxin, rather than a stress response provoked by auxin‐like compounds. Auxin‐induced MAPK pathway signaling was distinguished genetically in the Arabidopsis auxin response mutant axr4, in which MAPK activation by auxin, but not by salt stress, was significantly impaired. Perturbation of MAPK signaling in roots using inhibitors of a mammalian MAPKK blocked auxin‐activated transgene expression in BA3‐GUS seedlings, while potentiating higher than normal levels of MAPK activation in response to auxin. Data presented here indicate that MAPK pathway signaling is positively involved in auxin response, and further suggest that interactions among MAPK signaling pathways in plants influence plant responses to auxin.
Indole alkaloid biosynthesis in Catharanthus roseus: new enzyme activities and identification of cytochrome P450 CYP72A1 as secologanin synthase
Authors: Irmler Stefan , Schröder Gudrun , St‐Pierre Benoit , Crouch Nicholas P. , Hotze Michael , Schmidt Jürgen , Strack Dieter , Matern Ulrich , Schröder Joachim 
Published: August 2010

SummaryThe molecular characterization of CYP72A1 from Catharanthus roseus (Madagascar periwinkle) was described nearly a decade ago, but the enzyme function remained unknown. We now show by in situ hybridization and immunohistochemistry that the expression in immature leaves is epidermis‐specific. It thus follows the pattern previously established for early enzymes in the pathway to indole alkaloids, suggesting that CYP72A1 may be involved in their biosynthesis. The early reactions in that pathway, i.e. from geraniol to strictosidine, contain several candidates for P450 activities. We investigated in this work two reactions, the conversion of 7‐deoxyloganin to loganin (deoxyloganin 7‐hydroxylase, DL7H) and the oxidative ring cleavage converting loganin into secologanin (secologanin synthase, SLS). The action of DL7H has not been demonstrated in vitro previously, and SLS has only recently been identified as P450 activity in one other plant. We show for the first time that both enzyme activities are present in microsomes from C. roseus cell cultures. We then tested whether CYP72A1 expressed in E. coli as a translational fusion with the C. roseus P450 reductase (P450Red) has one or both of these activities. The results show that CYP72A1 converts loganin into secologanin.
NEC1, a novel gene, highly expressed in nectary tissue of Petunia hybrida
Authors: Ge Ya‐Xin , Angenent Gerco C. , Wittich Peter E. , Peters Jeroen , Franken John , Busscher Marco , Zhang Le‐Min , Dahlhaus Ellen , Kater Martin M. , Wullems George J. , Creemers‐Molenaar Tineke 
Published: August 2010

SummaryTo study the molecular regulation of nectary development, we cloned NEC1, a gene predominantly expressed in the nectaries of Petunia hybrida, by using the differential display RT–PCR technique. The secondary structure of the putative NEC1 protein is reminiscent of a transmembrane protein, indicating that the protein is incorporated into the cell membrane or the cytoplast membrane. Immunolocalization revealed that NEC1 protein is present in the nectaries. Northern blot analyses showed that NEC1 is highly expressed in nectary tissue and weakly in the stamen. GUS expression driven by the NEC1 promoter revealed GUS activity in the outer nectary parenchyma cells, the upper part of the filament and the anther stomium. The same expression pattern was observed in Brassica napus. GUS expression was observed as blue spots on the surface of very young nectaries that do not secrete nectar and do accumulate starch. GUS expression was highest in open flowers in which active secretion of nectar and starch hydrolysis had taken place. Ectopic expression of NEC1 resulted in transgenic plants that displayed a phenotype with leaves having 3–4 times more phloem bundles in mid‐veins than the wild‐type Petunia. The possible role of NEC1 gene in sugar metabolism and nectar secretion is discussed.
AtSUC3, a gene encoding a new Arabidopsis sucrose transporter, is expressed in cells adjacent to the vascular tissue and in a carpel cell layer
Authors: Meyer Stefan , Melzer Michael , Truernit Elisabeth , Hümmer Carola , Besenbeck Rainer , Stadler Ruth , Sauer Norbert 
Published: August 2010

SummaryThe cDNA corresponding to the open reading frame T17M13.3 from Arabidopsis chromosome II was isolated and the encoded protein was characterized as a member of a subgroup of higher plant sucrose transporters. The AtSUC3 (Arabidopsis thaliana sucrose transporter 3) open reading frame encodes a protein with 594 amino acid residues, being 81 and 82 residues longer than the previously described Arabidopsis sucrose carriers AtSUC1 and AtSUC2. About 50 of these additional amino acids are part of an extended cytoplasmic loop separating the N‐terminal from the C‐terminal half of the protein. For functional characterization the AtSUC3 cDNA was expressed in baker's yeast. Substrate specificities, energy dependence and Km values of the recombinant protein were determined. Removal of the enlarged cytoplasmic loop and expression of the truncated cDNA caused no detectable change in the kinetic properties of the protein, suggesting a transport‐independent function for this cytoplasmic domain. Immunolocalization with an AtSUC3‐specific antiserum identified the protein in a cell layer separating the phloem from the mesophyll and in a single, subepidermal cell layer of the carpels that is important for pod dehiscence. These localizations suggest a possible role of AtSUC3 in the funnelling of sucrose from the mesophyll towards the phloem, and possibly in pod shatter.
Interactions betweenhy1andgunmutants ofArabidopsis, and their implications for plastid/nuclear signalling
Authors: Vinti Giovanna , Hills Alison , Campbell Shona , Bowyer John R. , Mochizuki Nobuyoshi , Chory Joanne , López‐Juez Enrique 
Published: August 2010

SummaryLhcband other nuclear genes for chloroplastic proteins are regulated by several signals. Among them, light and retrograde signals from the plastid itself appear to act through closely related mechanisms. To investigate this interaction, we analysed anArabidopsismutant,hy1, deficient in plastidic heme oxygenase.hy1is defective in phytochrome chromophore biosynthesis, which has other indirect effects on tetrapyrrole metabolism. We generated double mutants betweenhy1‐6.2, genetically a null mutation, and three knowngun(genome uncoupled) mutants, defective in retrograde plastid signalling. Recent molecular evidence showsGUN5to be involved in tetrapyrrole metabolism (N. Mochizuki and J. Chory, manuscript in preparation). We observedhy1gun4to be semi‐albino plants, andhy1gun5albino lethal, in a high‐light‐sensitive manner. Both double mutants showed defective greening and chloroplast development, and expressedLhcbat reduced levels specifically in high light. Their degree of ‘genome uncoupling’ (Lhcbexpression in the absence of functional chloroplasts) was similar to that observed in single mutants. These results can be interpreted as a metabolic (rather than genetic) interaction betweenHY1andGUN4orGUN5, and this in turn supports the involvement of tetrapyrroles as plastid signals. The tetrapyrrole precursor 5‐aminolevulinic acid (ALA) inhibitedLhcbexpression inhy1. Surprisingly, ALA also rescued photomorphogenesis ofhy1. We speculate that either one tetrapyrrole intermediate, which can accumulate anomalously inhy1, or an altered ratio between two intermediates, plays a role as a repressor ofLhcbexpression.gun1did not exacerbate the plastid orLhcbexpression phenotype ofhy1. This can be interpreted as a role forgun1strictly on the same pathway ashy1or, more likely, as evidence for the existence of at least one separate, non‐tetrapyrrole related plastid signal.
Two kinesin‐related proteins associated with the cold‐stable cytoskeleton of carrot cells: characterization of a novel kinesin, DcKRP120‐2
Authors: Barroso Consuelo , Chan Jordi , Allan Viki , Doonan John , Hussey Patrick , Lloyd Clive 
Published: August 2010

SummaryWe have previously described the biochemical isolation of 65 kDa and 120 kDa microtubule‐associated proteins from carrot cytoskeletons. The 65 kDa MAPs have subsequently been shown to be structural MAPs that reconstitute 30 nm cross‐bridges of the kind that maintain cortical microtubules in parallel groups. By exploiting its avid binding to microtubules, we have now devised a method for isolating MAP120 from protoplast extracts, and shown that it has properties of a kinesin‐related protein. MAP120 segregates with the cold stable pool of microtubules in carrot cytoskeletons, whilst the 65 kDa MAPs are also associated with the cold‐sensitive microtubules. On gradient gels, MAP120 resolves as two kinesin‐like bands. We report the isolation of a carrot cDNA, DcKRP120‐2, corresponding to a novel kinesin of the BimC class known to move to the plus ends of microtubules. Antibodies raised against specific expressed sequences recognize the upper band, while the lower band is recognized by antibodies to the tobacco kinesin‐related protein, TKRP125. We have also isolated a partial genomic carrot DNA, DcKRP120‐1, homologous to the motor region of tobacco TKRP125. Immunofluorescence of the two proteins produces different staining patterns. Anti‐TKRP125 labels the cortical microtubules and the pre‐prophase band, but anti‐DcKRP120–2 does so only weakly. Both clearly stain the spindle and the phragmoplast, but in a proportion of cells anti‐DcKRP120‐2 strongly decorates the phragmoplast mid‐line where the plus ends of the microtubules overlap. We discuss the potential roles of these proteins during the microtubule cycle.
Cell death of barley aleurone protoplasts is mediated by reactive oxygen species
Authors: Bethke Paul C. , Jones Russell L. 
Published: August 2010

SummaryThe barley aleurone layer is a terminally differentiated secretory tissue whose activity is hormonally controlled. The plant hormone gibberellic acid (GA) stimulates the secretion of hydrolytic enzymes and triggers the onset of programmed cell death (PCD). Abscisic acid (ABA) antagonizes the effects of GA and inhibits enzyme secretion and PCD. Reactive oxygen species (ROS) are key players in many types of PCD, and data presented here implicate ROS in hormonally regulated death of barley aleurone cells. Incubation of aleurone layers or protoplasts in H2O2‐containing media results in death of GA‐treated but not ABA‐treated aleurone cells. Cells that are programmed to die are therefore less able to withstand ROS than cells that are programmed to remain alive. Illumination of barley aleurone protoplasts with blue or UV‐A light results in a rapid increase in intracellular H2O2 production. GA‐treated protoplasts die rapidly in response to this increase in intracellular H2O2 production, but ABA‐treated protoplasts do not die. The rate of light‐induced death could be slowed by antioxidants, and incubating protoplasts in the dark with the antioxidant butylated hydroxy toluene reduces the rate of hormonally induced death. Taken together, these data demonstrate that GA‐treated aleurone protoplasts are less able than ABA‐treated protoplasts to tolerate internally generated or exogenously applied H2O2, and strongly suggest that ROS are components of the hormonally regulated cell death pathway in barley aleurone cells.