bluuebunny/crossref_metadata_2025_split huggingface dataset:
Etiology, Outcome and Prognostic Indicators of Childhood Fulminant Hepatic Failure in the United Kingdom
Authors: Lee Way Seah , McKiernan Patrick , Kelly Deirdre Anne 
Published: April 2005

ABSTRACTObjective:To study the etiology, outcome and prognostic indicators in children with fulminant hepatic failure in the United Kingdom.Design:Retrospective review of all patients <17 years with fulminant hepatic failure from 1991 to 2000. Fulminant hepatic failure was defined as presence of coagulopathy (prothrombin time >24 seconds or International Normalized Ratio >2.0) with or without hepatic encephalopathy within 8 weeks of the onset of symptoms.Setting:Liver Unit, Birmingham Children's Hospital, United Kingdom.Results:Ninety‐seven children (48 male, 49 female; median age, 27 months; range, 1 day‐192.0 months) were identified with fulminant hepatic failure. The etiologies were: 22 metabolic, 53 infectious, 19 drug‐induced, and 3 autoimmune hepatitis. The overall survival rate was 61%. 33% (32/97) recovered spontaneously with supportive management. Fifty‐five children were assessed for liver transplantation. Four were unstable and were not listed for liver transplantation; 11 died while awaiting liver transplantation. Liver transplantation was contraindicated in 10 children. Of the 40 children who underwent liver transplantation, 27 survived. Children with autoimmune hepatitis, paracetamol overdose or hepatitis A were more likely to survive without liver transplantation. Children who had a delay between the first symptom of liver disease and the onset of hepatic encephalopathy (median, 10.5 days versus 3.5 days), higher plasma bilirubin (299 μmol/L versus 80 μmol/L), higher prothrombin time (62 seconds versus 40 seconds) or lower alanine aminotransferase (1288 IU/L versus 2929 IU/L) levels on admission were more likely to die of fulminant hepatic failure or require liver transplantation (P < 0.05). On multivariate analysis, the significant independent predictors for the eventual failure of conservative therapy were time to onset of hepatic encephalopathy >7 days, prothrombin time >55 seconds and alanine aminotransferase ≤2384 IU/L on admission.Conclusions:Children with fulminant hepatic failure with severe coagulopathy, lower alanine aminotransferase on admission and prolonged duration of illness before the onset of hepatic encephalopathy are more likely to require liver transplantation. Early referral to a specialized center for consideration of liver transplantation is vital.
Origin of Absorption Bands Observed in the Spectra of Silver Ion‐Exchanged Soda–Lime–Silica Glass
Authors: Ahmed A. A. , Allah E. W. Abd 
Published: April 2005

The spectral absorption of Ag‐containing soda–lime–silica glasses, prepared by ion exchange under different conditions and subjected to different heat treatments, was measured in the UV and visible. Tentative Gaussian resolution analysis was performed to accurately define the component bands of the experimentally observed absorption spectra. The spectral data were used to identify the different states of silver and the shape and the spatial arrangement of the silver particles formed in the samples treated under different conditions. The data obtained were also compared with the known characteristic absorption of definite silver states. The spectra of glasses after ion exchange showed a single sharp symmetrical absorption band in the UV at 305 nm. After heat treatment, one or two additional absorption bands in the UV and visible were observed, depending on the heat‐treatment conditions. The behavior of these bands—sequence of appearance, ranges of stability and intensity fluctuation, as a function of temperature and time of ion exchange and heat treatment—would suggest the following band assignment:

Band at 305 nm is associated with Ag+ ions.
Band at 350 nm is associated with Ag° (elemental Ag atoms).
Band at 420 nm is associated with (Ag°)n (silver crystallites, n is the number of silver atoms forming the crystallite).

This band assignment is in conformity with the sequence of events widely accepted to take place during silver staining. Additional information deduced from the single absorption band associated with silver particles indicates that the silver particles are spherical in shape and isolated from each other to the extent necessary to prevent electromagnetic interaction.
22‐ene‐25‐oxa‐vitamin D: a new vitamin D analogue with profound immunosuppressive capacities
Authors: Daniel C. , Schlauch T. , Zügel U. , Steinmeyer A. , Radeke H. H. , Steinhilber D. , Stein J. 
Published: April 2005

AbstractBackground  The biologic role of 1,25‐dihydroxyvitamin D3, such as anti‐inflammatory functions, reduction of cytokine production by T cells and immunoglobulin production by B cells, is well established. However, its clinical use as an immunosuppressive agent is limited because of the hypercalcemic toxicity occurring after systemic application. The purpose of this study was to investigate the immunmodulatory effects of 22‐ene‐25‐oxa‐vitamin D (ZK156979), a novel low calcemic vitamin D analogue.Materials and methods  Human peripheral blood mononuclear cells (PBMCs) from healthy donors were isolated using the Ficoll Hypaque technique, cultured for 24 h and treated with different concentrations of ZK156979 ranging from 10−5 to 10−10 mol L−1 compared with 1,25‐dihydroxyvitamin D3[10−5−10−10 mol L−1] following phytohaemagglutinin (PHA) stimulation. Interferon gamma (IFNγ), tumour necrosis factor alpha (TNFα), interleukin 1 beta (IL‐1β), interleukin 10 (IL‐10) and interleukin 4 (IL‐4) secretion in supernatants were measured by ELISA.Results  ZK156979 inhibited the PHA‐induced Th1‐response (IFNγ and TNFα levels) and the macrophage‐product IL‐1β in a concentration‐dependent manner (10−10−10−5 mol L−1) with the efficiency on cytokine expression compared with 1,25‐dihydroxyvitamin D3 being slightly reduced. In contrast, ZK156979 and 1,25‐dihydroxyvitamin D3 both affected the Th2 response, leading to significantly increased IL‐10‐ and IL‐4 secretion.Conclusions  ZK156979 is a member of novel vitamin D analogues revealing prominent immunomodulatory and suppressive characteristics with distinctive inhibition of Th1‐cytokines whereas the Th2 compartment is augmented, thus providing a considerable therapeutic potential in T‐cell ‐mediated diseases.
Oxidative stress and cardiovascular risk: the role of vascular NAD(P)H oxidase and its genetic variants
Authors: Soccio M. , Toniato E. , Evangelista V. , Carluccio M. , De Caterina R. 
Published: April 2005

AbstractSeveral risk factors for coronary artery disease (CAD) induce atherosclerosis through endothelial activation and dysfunction, and ample evidence now suggests that the balance between production and removal of reactive oxygen species (ROS) – a condition termed oxidative stress – is implicated in such processes. A main source of ROS in vascular cells is the reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase system. This is a membrane‐associated enzyme, composed of five subunits, catalyzing the one‐electron reduction of oxygen, using NADH or NADPH as the electron donor. One of the system subunits, termed p22‐phox, has a polymorphic site on exon 4, associated with variable enzyme activity. This polymorphism is generated by a point mutation (C242T) producing a substitution of histidine with tyrosine at position 72, which affects one of the heme binding sites essential for the NAD(P)H enzyme activity. The consequent decrease of superoxide production thus characterizes a phenotype candidate for conferring to the carrier a reduced susceptibility to CAD. At present, however, the body of evidence from current literature is not yet sufficient to confirm or exclude the hypothesis that the C242T polymorphism protects from CAD. The functional effects of this polymorphism and the potential and its pathophysiological consequences also need further investigation.
Long‐term response and recovery to nutrient addition of a partitioned arctic lake
Authors: O'BRIEN W. JOHN , BARFIELD MICHAEL , BETTEZ NEIL , HERSHEY ANNE E. , HOBBIE JOHN E. , KIPPHUT GEORGE , KLING GEORGE , MILLER MICHAEL C. 
Published: April 2005

Summary1. To study the bottom‐up linkages in arctic lakes, we treated one side of a partitioned lake with inorganic nitrogen and phosphorus for a 6‐week period each summer for 6 years starting in the summer of 1985. We took a variety of weekly measurements to determine the impact of the nutrient loading on the lake and continued weekly measurements for 2–6 years after the cessation of nutrient loading to observe the recovery of the treated side. The loading rates (2.91 mmol N m−2 day−1 and 0.23 mmol P m−2 day−1) were five times the calculated loading rates for Toolik Lake, located nearby.2. In all 6 years of nutrient addition, phytoplankton biomass and productivity were greater in the treated sector than the reference sector. In the first 4 years of nutrient addition there was no flux of phosphorus from the mineral‐rich sediments. This changed in the last 2 years of nutrient addition as phosphorus was released to the lake.3. The response of the animal community to increased plant production was mixed. One of the four macro‐zooplankton species (Daphnia longiremis) increased in number by about twofold in the first 5 years. However, the copepod Cyclops scutifer showed no response during the treatment phase of the study. The benthic invertebrate response was also mixed. After a 2‐year lag time the snail Lymnaea elodes increased in the treated lake sector but chironomids did not.4. Ecosystem response to fertilisation was not controlled solely by nutrient addition because phosphorus was not recycled from the sediments until the last 2 years of nutrient addition. Phytoplankton still showed the effects of nutrient addition in the recovery period and the hypolimnion of the treated sector was still anaerobic starting at 6 m in 1996.
Food webs in tropical Australian streams: shredders are not scarce
Authors: CHESHIRE KIM , BOYERO LUZ , PEARSON RICHARD G. 
Published: April 2005

Summary1. Macroinvertebrates were collected in dry and wet seasons from riffles and pools in two streams in tropical north Queensland. Total biomass, abundance and species richness were higher in riffles than in pools but did not differ between streams or seasons.2. Gut contents of all species were identified. Cluster analysis based on gut contents identified five dietary groups: I, generalist collectors; II, generalist shredders and generalist predators; III, generalist scrapers; IV, specialist shredders; and V, specialist predators. Species were allocated to functional feeding groups (FFGs) based on these dietary groups.3. Many species were generalist in their diets, but specialist predators and shredders were particularly prominent components of the invertebrate assemblages in terms of biomass and species richness.4. Community composition (proportions of biomass, abundance and species richness of the different FFGs) varied between habitat types, but not between streams or seasons, although differences between riffles and pools varied with season.5. Comparison of the fauna of 20 streams showed that our study sites were similar to, or not atypical of, low‐order streams in the Queensland wet tropics.
The impact of sediment reworking by opportunistic chironomids on specialised mayflies
Authors: DE HAAS ELSKE M. , KRAAK MICHIEL H.S. , KOELMANS ALBERT A. , ADMIRAAL WIM 
Published: April 2005

Summary1. Bioturbation, by definition, changes the structure and properties of sediments, thereby altering the environment of the bioturbator and other benthic species. In addition to the indirect effects of sediment reworking (e.g. changes in water quality), bioturbating species may also directly interfere with other species via competition. This study aims, therefore, to examine both the direct and indirect effects of sediment reworking by an opportunistic detritivore on survival and growth of a specialised mayfly species.2. Bioturbation was imposed by adding different densities of the midge Chironomus riparius to clean and polluted sediments. Changes in water quality and sediment properties, and survival and growth of the mayfly Ephoron virgo were assessed.3. Chironomid density had a strong negative effect on the concentrations of metals, nutrients and particles in the overlying water, but increased the penetration of oxygen into the sediment. Survival and growth of E. virgo were strongly reduced in the presence of chironomids. In the polluted sediment, the activity of chironomids enhanced the negative effects of pollution on E. virgo. In the clean sediment, inhibition of the mayfly was even more pronounced.4. This suggests that direct disturbance by C. riparius was more important than indirect changes in water quality, and over‐ruled the potential positive effects of improved oxygen penetration. The results indicated that the distribution of small insects, such as E. virgo, can be limited by bioturbating benthic invertebrates.
Submerged macrophytes, zooplankton and the predominance of low‐ over high‐chlorophyll states in western boreal, shallow‐water wetlands
Authors: NORLIN J. IVOR , BAYLEY SUZANNE E. , ROSS LISETTE C. M. 
Published: April 2005

Summary1. Shallow‐water (<2 m deep) wetlands in northern Alberta's western boreal forest tend to have either extremely high‐chlorophyll, pea‐green water or water that is low in chlorophyll and clear. The relative importance of top‐down processes (e.g. zooplankton grazing) compared with bottom‐up processes (e.g. nutrient limitation) for regulating the existence of these alternate states has yet to be explicitly investigated in these poorly studied waterbodies.2. To assess the relationship between chemical and biological factors and the predominance of low‐chlorophyll over high‐chlorophyll states, a survey of 24 shallow‐water wetlands in northern Alberta was conducted over the summers of 2001 and 2002.3. In wetlands without fish, statistical analysis indicated that high‐ and low‐chlorophyll sites could be differentiated with 82% accuracy based solely on whether submerged aquatic vegetation (SAV) coverage was greater or less than 25%. Further, high‐SAV lakes with zooplankton communities dominated by large cladocerans were clear 96% of the time.4. In the few wetlands that supported stickleback populations, large cladocerans were absent. However, the development of zooplankton communities dominated by small cladocera (Bosmina) with calanoid copepods in fish‐containing wetlands corresponded with a shift from high‐ to low‐chlorophyll states.5. Results suggest that in fishless wetlands high‐SAV coverage and grazing by large, SAV‐associated cladocerans promotes low‐chlorophyll states. Results also suggest that suppression of macroinvertebrate predators by sticklebacks allowing Bosmina to flourish may also promote low‐chlorophyll, clear‐water conditions.
Benthic–pelagic coupling in the population dynamics of the harmful cyanobacterium Microcystis
Authors: VERSPAGEN JOLANDA M. H. , SNELDER EVELINE O. F. M. , VISSER PETRA M. , JÖHNK KLAUS D. , IBELINGS BAS W. , MUR LUUC R. , HUISMAN JEF 
Published: April 2005

Summary1. In eutrophic lakes, large amounts of the cyanobacterium Microcystis may overwinter in the sediment and re‐inoculate the water column in spring.2. We monitored changes in pelagic and benthic populations of Microcystis in Lake Volkerak, The Netherlands. In addition, sedimentation rates and the rate of recruitment from the sediment were measured using traps. These data were used to model the coupling between the benthic and pelagic populations and to calculate the contribution of overwintering benthic and pelagic populations to the magnitude of the pelagic summer bloom.3. Changes in the benthic Microcystis population showed a time lag of 3–14 weeks compared with the pelagic population. This time lag increased with lake depth. The largest amount of benthic Microcystis was found in the deepest parts of the lake. These observations suggest horizontal transport of sedimented Microcystis from shallow to deep parts of the lake.4. Recruitment from and sedimentation to the sediment occurred throughout the year, with highest recruitment and sedimentation rates during summer. Model simulations indicate that the absence of benthic recruitment would reduce the summer bloom by 50%.5. In spring, the total pelagic population was three to six times smaller than the total benthic population. Yet, model simulations predict that the absence of this small overwintering pelagic population would reduce the summer bloom by more than 64%.6. Reduction of the overwintering pelagic populations, for instance by flushing, may be a useful management strategy to suppress or at least delay summer blooms of Microcystis.
Molecular cloning, characterization, and downregulation of an acyltransferase that catalyzes the malonylation of flavonoid and naphthol glucosides in tobacco cells
Authors: Taguchi Goro , Shitchi Yoshihiro , Shirasawa Sakiko , Yamamoto Hirobumi , Hayashida Nobuaki 
Published: April 2005

SummaryTobacco cells (Nicotiana tabacum L. Bright Yellow T‐13) exposed to harmful naphthols accumulate them as glucosylated and further modified compounds [Taguchi et al. (2003a) Plant Sci. 164, 231–240]. In this study, we identified the accumulated compounds to be 6′‐O‐malonylated glucosides of naphthols. Cells treated with various phenolic compounds accumulated the flavonoids mainly as malonylglucosides. To clarify the function of this malonylation in tobacco, we isolated the cDNA encoding a malonyltransferase (NtMaT1) from a cDNA library derived from tobacco cells. The heterologous expression of the gene in Escherichia coli revealed that the recombinant enzyme had malonyltransferase activity against several phenolic glucosides such as flavonoid 7‐O‐glucosides, flavonoid 3‐O‐glucosides and naphthol glucosides. The substrate preference of the enzyme was similar to that of the tobacco cell extract. Malonylation activity in the transgenic cells markedly decreased with the suppression of the expression of NtMaT1 mRNA in tobacco BY‐2 cells by RNA interference. The compounds administered to the transgenic cells were accumulated in the cells as glucosides or other modified compounds in place of malonylglucosides. These results show that NtMaT1 is the main catalyst of malonylation on glucosides of xenobiotic flavonoids and naphthols in tobacco plants.
Kinase partner protein interacts with the LePRK1 and LePRK2 receptor kinases and plays a role in polarized pollen tube growth
Authors: Kaothien Pulla , Ok Sung Han , Shuai Bin , Wengier Diego , Cotter Robyn , Kelley Dior , Kiriakopolos Stephanie , Muschietti Jorge , McCormick Sheila 
Published: April 2005

SummaryThe pollen‐specific receptor kinases LePRK1 and LePRK2 have localization and expression profiles that strongly suggest they play roles in pollen germination and tube growth. To identify downstream components of LePRK signaling, we used their cytoplasmic domains (CDs) as baits in yeast two‐hybrid screens of a tomato pollen cDNA library. A pollen‐specific protein we named kinase partner protein (KPP) interacted with the CDs of both LePRK1 and LePRK2 in yeast and in an in vitro pull‐down assay, and with LePRK2 in a co‐immunoprecipitation assay. KPP is a peripheral membrane protein and is phosphorylated in pollen. Pollen tubes over‐expressing KPP developed balloon‐like tips with abnormal cytoplasmic streaming and F‐actin arrangements and plants over‐expressing KPP exhibited impaired transmission of the transgene through the male. KPP‐like genes are found only in plants; the 14 family members in Arabidopsis thaliana exhibit diverse expression patterns and potentially play roles in signaling pathways in other tissues.
The Calvin cycle in cyanobacteria is regulated by CP12 via the NAD(H)/NADP(H) ratio under light/dark conditions
Authors: Tamoi Masahiro , Miyazaki Takashi , Fukamizo Tamo , Shigeoka Shigeru 
Published: April 2005

SummaryIn Synechococcus PCC7942 cells grown in the dark, the concentrations of NAD(H) and NADP(H) were 128 ± 2.5 and 483 ± 4.0 μm, respectively, while those in the cells under light conditions were 100 ± 5.0 and 649 ± 7.0 μm, respectively. Analysis of gel filtration indicated that the change of the ratio of NADP(H) to NAD(H) in cyanobacterial cells under light/dark conditions controls the reversible dissociation of the PRK/CP12/GAPDH complex (approximately 520 kDa) consisting of phosphoribulokinase (PRK), CP12, and glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH). S. 7942 CP12 lacked the two Cys residues essential for formation of the N‐terminal peptide loop in the CP12 of higher plants, but the N‐terminal region of S. 7942 CP12 had the ability to be associated with PRK. The growth of mutant cells in which the CP12 gene was disrupted by a kanamycin resistance cartridge gene was almost the same as that of wild‐type cells under continuous light conditions. However, under the light/dark cycle (12 h/12 h), the growth of CP12‐disrupted mutant cells was significantly inhibited compared with that of wild‐type cells. The mutant cells showed a decreased rate of O2 consumption and an increased level of ribulose 1,5‐bisphosphate compared with wild‐type cells in the dark. These data suggest that under light and dark conditions, the oligomerization of CP12 with PRK and GAPDH regulates the activities of both enzymes and thus the carbon flow from the Calvin cycle to the oxidative pentose phosphate cycle.
AtATG18a is required for the formation of autophagosomes during nutrient stress and senescence in Arabidopsis thaliana
Authors: Xiong Yan , Contento Anthony L. , Bassham Diane C. 
Published: April 2005

SummaryVacuolar autophagy is a major pathway by which eukaryotic cells degrade macromolecules, either to remove damaged or unnecessary proteins, or to produce respiratory substrates and raw materials to survive periods of nutrient deficiency. During autophagy, a double membrane forms around cytoplasmic components to generate an autophagosome, which is transported to the vacuole. The outer membrane fuses with the vacuole or lysosome, and the inner membrane and its contents are degraded by vacuolar or lysosomal hydrolases. We have identified a small gene family in Arabidopsis thaliana, members of which show sequence similarity to the yeast autophagy gene ATG18. Members of the AtATG18 gene family are differentially expressed in response to different growth conditions, and one member of this family, AtATG18a, is induced both during sucrose and nitrogen starvation and during senescence. RNA interference was used to generate transgenic lines with reduced AtATG18a expression. These lines show hypersensitivity to sucrose and nitrogen starvation and premature senescence, both during natural senescence of leaves and in a detached leaf assay. Staining with the autophagosome‐specific fluorescent dye monodansylcadaverine revealed that, unlike wild‐type plants, AtATG18a RNA interference plants are unable to produce autophagosomes in response to starvation or senescence conditions. We conclude that the AtATG18a protein is likely to be required for autophagosome formation in Arabidopsis.