bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycerophosphocholine Metabolism in Higher Plant Cells. Evidence of a New Glyceryl-Phosphodiester Phosphodiesterase
Authors: van der Rest Benoı̂t , Boisson Anne-Marie , Gout Elisabeth , Bligny Richard , Douce Roland 
Published: September 2002

AbstractGlycerophosphocholine (GroPCho) is a diester that accumulates in different physiological processes leading to phospholipid remodeling. However, very little is known about its metabolism in higher plant cells. 31P-Nuclear magnetic resonance spectroscopy and biochemical analyses performed on carrot (Daucus carota) cells fed with GroPCho revealed the existence of an extracellular GroPCho phosphodiesterase. This enzymatic activity splits GroPCho into sn-glycerol-3-phosphate and free choline. In vivo, sn-glycerol-3-phosphate is further hydrolyzed into glycerol and inorganic phosphate by acid phosphatase. We visualized the incorporation and the compartmentation of choline and observed that the major choline pool was phosphorylated and accumulated in the cytosol, whereas a minor fraction was incorporated in the vacuole as free choline. Isolation of plasma membranes, culture medium, and cell wall proteins enabled us to localize this phosphodiesterase activity on the cell wall. We also report the existence of an intracellular glycerophosphodiesterase. This second activity is localized in the vacuole and hydrolyzes GroPCho in a similar fashion to the cell wall phosphodiesterase. Both extra- and intracellular phosphodiesterases are widespread among different plant species and are often enhanced during phosphate deprivation. Finally, competition experiments on the extracellular phosphodiesterase suggested a specificity for glycerophosphodiesters (apparentK m of 50 μm), which distinguishes it from other phosphodiesterases previously described in the literature.
Inhibition of Squalene Synthase and Squalene Epoxidase in Tobacco Cells Triggers an Up-Regulation of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase
Authors: Wentzinger Laurent F. , Bach Thomas J. , Hartmann Marie-Andrée 
Published: September 2002

Abstract
To get some insight into the regulatory mechanisms controlling the sterol branch of the mevalonate pathway, tobacco (Nicotiana tabacum cv Bright Yellow-2) cell suspensions were treated with squalestatin-1 and terbinafine, two specific inhibitors of squalene synthase (SQS) and squalene epoxidase, respectively. These two enzymes catalyze the first two steps involved in sterol biosynthesis. In highly dividing cells, SQS was actively expressed concomitantly with 3-hydroxy-3-methylglutaryl coenzyme A reductase and both sterol methyltransferases. At nanomolar concentrations, squalestatin was found to inhibit efficiently sterol biosynthesis as attested by the rapid decrease in SQS activity and [14C]radioactivity from acetate incorporated into sterols. A parallel dose-dependent accumulation of farnesol, the dephosphorylated form of the SQS substrate, was observed without affecting farnesyl diphosphate synthase steady-state mRNA levels. Treatment of tobacco cells with terbinafine is also shown to inhibit sterol synthesis. In addition, this inhibitor induced an impressive accumulation of squalene and a dose-dependent stimulation of the triacylglycerol content and synthesis, suggesting the occurrence of regulatory relationships between sterol and triacylglycerol biosynthetic pathways. We demonstrate that squalene was stored in cytosolic lipid particles, but could be redirected toward sterol synthesis if required. Inhibition of either SQS or squalene epoxidase was found to trigger a severalfold increase in enzyme activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, giving first evidence for a positive feedback regulation of this key enzyme in response to a selective depletion of endogenous sterols. At the same time, no compensatory responses mediated by SQS were observed, in sharp contrast to the situation in mammalian cells.
N-Acylethanolamines Are Metabolized by Lipoxygenase and Amidohydrolase in Competing Pathways during Cottonseed Imbibition
Authors: Shrestha Rhidaya , Noordermeer Minke A. , Van der Stelt Marcelis , Veldink Gerrit A. , Chapman Kent D. 
Published: September 2002

Abstract
Saturated and unsaturated N-acylethanolamines (NAEs) occur in desiccated seeds primarily as 16C and 18C species withN-palmitoylethanolamine andN-linoleoylethanolamine (NAE 18:2) being most abundant. Here, we examined the metabolic fate of NAEs in vitro and in vivo in imbibed cotton (Gossypium hirsutum) seeds. When synthetic [1-14C]N-palmitoylethanolamine was used as a substrate, free fatty acids (FFA) were produced by extracts of imbibed cottonseeds. When synthetic [1-14C]NAE 18:2 was used as a substrate, FFA and an additional lipid product(s) were formed. On the basis of polarity, we presumed that the unidentified lipid was a product of the lipoxygenase (LOX) pathway and that inclusion of the characteristic LOX inhibitors nordihydroguaiaretic acid and eicosatetraynoic acid reduced its formation in vitro and in vivo. The conversion of NAE 18:2 in imbibed cottonseed extracts to 12-oxo-13-hydroxy-N-(9Z)-octadecanoylethanolamine was confirmed by gas chromatography-mass spectrometry, indicating the presence of 13-LOX and 13-allene oxide synthase, which metabolized NAE 18:2. Cell fractionation studies showed that the NAE amidohydrolase, responsible for FFA production, was associated mostly with microsomes, whereas LOX, responsible for NAE 18:2-oxylipin production, was distributed in cytosol-enriched fractions and microsomes. The highest activity toward NAE by amidohydrolase was observed 4 to 8 h after imbibition and by LOX 8 h after imbibition. Our results collectively indicate that two pathways exist for NAE metabolism during seed imbibition: one to hydrolyze NAEs in a manner similar to the inactivation of endocannabinoid mediators in animal systems and the other to form novel NAE-derived oxylipins. The rapid depletion of NAEs by these pathways continues to point to a role for NAE metabolites in seed germination.
Successive Glycosyltransfer Activity and Enzymatic Characterization of Pectic Polygalacturonate 4-α-Galacturonosyltransferase Solubilized from Pollen Tubes ofPetunia axillaris Using Pyridylaminated Oligogalacturonates as Substrates
Authors: Akita Kazumasa , Ishimizu Takeshi , Tsukamoto Tatsuya , Ando Toshio , Hase Sumihiro 
Published: September 2002

Abstract
Polygalacturonate 4-α-galacturonosyltransferase (pectin synthase) was solubilized from pollen tubes of Petunia axillaris and characterized. To accomplish this, an assay method using fluorogenic pyridylaminated-oligogalacturonic acids (PA-OGAs) as acceptor substrates was developed. When the pollen tube enzyme was solubilized with 0.5% (v/v) Triton X-100 and was incubated with PA-OGA and UDP-galacturonic acid (UDP-GalUA), successive transfer activity of more than 10 GalUAs from UDP-GalUA to the nonreducing end of PA-OGA was observed by diethylaminoethyl high-performance liquid chromatography. This activity was time- and enzyme concentration-dependent. The optimum enzyme activity was observed at pH 7.0 and 30°C. Among the PA-OGAs investigated, those with a degree of polymerization of more than 10 were preferred as substrates. The crude pollen tube enzyme had an apparentK m value of 13 μm for the PA-OGA with a degree of polymerization 11 and 170 μm for UDP-GalUA. The characteristics of the P. axillarispollen tube enzyme and the usefulness of fluorogenic PA-OGAs for the assay of this enzyme are discussed.
Characterization of an Acyltransferase Capable of Synthesizing Benzylbenzoate and Other Volatile Esters in Flowers and Damaged Leaves of Clarkia breweri
Authors: D'Auria John C. , Chen Feng , Pichersky Eran 
Published: September 2002

Abstract
A cDNA encoding a protein with 456 amino acids whose sequence shows considerable similarity to plant acyltransferases was identified among 750 Clarkia breweri flower expressed sequence tags. The cDNA was expressed in Escherichia coli, and the protein produced was shown to encode the enzyme benzoyl-coenzyme A (CoA):benzyl alcohol benzoyl transferase (BEBT). BEBT catalyzes the formation of benzylbenzoate, a minor constituent of the C. breweri floral aroma, but it also has activity with a number of other alcohols and acyl CoAs. The BEBTgene is expressed in different parts of the flowers with maximal RNA transcript levels in the stigma, and no expression was observed in the leaves under normal conditions. However, BEBT expression was induced in damaged leaves, reaching a maximum 6 h after damage occurred. We also show here that a closely related tobacco (Nicotiana tabacum) gene previously shown to be induced in leaves after being challenged by phytopathogenic bacteria also has BEBT activity, whereas the most similar protein to BEBT in the Arabidopsis proteome does not use benzoyl CoA as a substrate and instead can use acetyl CoA to catalyze the formation of cis-3-hexen-1-yl acetate, a green-leaf volatile.
Nitric Oxide Negatively Modulates Wound Signaling in Tomato Plants
Authors: Orozco-Cárdenas Martha L. , Ryan Clarence A. 
Published: September 2002

AbstractSynthesis of proteinase inhibitor I protein in response to wounding in leaves of excised tomato (Lycopersicon esculentum) plants was inhibited by NO donors sodium nitroprusside andS-nitroso-N-acetyl-penicillamine. The inhibition was reversed by supplying the plants with the NO scavenger 2-(4-carboxiphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. NO also blocked the hydrogen peroxide (H2O2) production and proteinase inhibitor synthesis that was induced by systemin, oligouronides, and jasmonic acid (JA). However, H2O2 generated by glucose oxidase and glucose was not blocked by NO, nor was H2O2-induced proteinase inhibitor synthesis. Although the expression of proteinase inhibitor genes in response to JA was inhibited by NO, the expression of wound signaling-associated genes was not. The inhibition of wound-inducible H2O2 generation and proteinase inhibitor gene expression by NO was not due to an increase in salicylic acid, which is known to inhibit the octadecanoid pathway. Instead, NO appears to be interacting directly with the signaling pathway downstream from JA synthesis, upstream of H2O2synthesis. The results suggest that NO may have a role in down-regulating the expression of wound-inducible defense genes during pathogenesis.
Study of the effectiveness of the US safety standard for child resistant cigarette lighters
Authors: Smith L E , Greene M A , Singh H A 
Published: September 2002

Objective:The purpose of this research is to evaluate the effectiveness of the US Consumer Product Safety Commission’s (CPSC) Safety Standard for Cigarette Lighters, which requires that disposable cigarette lighters be resistant to operation by children younger than age 5.Methods:Fire data on children playing with lighters were solicited from selected US fire departments for incidents occurring from 1997–99, to identify the proportion of such fires caused by children younger than age 5 playing with cigarette lighters. These data were compared with similar data from 1985–87. An odds ratio was used to determine if there was a significant decrease in cigarette lighter fires caused by children younger than age 5 compared to children ages 5 and older. To estimate fires that would have occurred without the standard, the odds ratio, adjusted for population, was applied to 1998 national estimates of fires occurring. National estimates of 1998 fire losses were based on data from the National Fire Incident Reporting System and the National Fire Protection Association to which the 1997–99 age and lighter type distributions were applied. The difference between the fire losses that would have occurred and those that did occur represented fire losses prevented.Results:In the post-standard study, 48% of the cigarette lighter fires were started by children younger than age 5, compared with 71% in the pre-standard study. The odds ratio of 0.42 was statistically significant (p<0.01). This represented a 58% reduction in fires caused by the younger age group compared to the older age group. When applied to national fire loss data, an estimated 3300 fires, 100 deaths, 660 injuries, and $52.5 million in property loss were prevented by the standard in 1998, totaling $566.8 million in 1998 societal savings.Conclusions:The CPSC standard requiring child resistant cigarette lighters has reduced fire deaths, injuries, and property loss caused by children playing with cigarette lighters and can be expected to prevent additional fire losses in subsequent years.
Characteristics of pregnant women in motor vehicle crashes
Authors: Weiss H B , Strotmeyer S 
Published: September 2002

Objectives:Motor vehicle crashes are the leading cause of hospitalized trauma during pregnancy. Maternal injury puts the fetus at great risk, yet little is known about the incidence, risks, and characteristics of pregnant women in crashes.Setting and methods:Police reported crashes were analyzed from the National Automotive Sampling System Crashworthiness Data System. Since 1995, this system recorded pregnancy/trimester status. Pregnant and non-pregnant women 15–39 years of age were compared by age, driver status, seat belt use, and treatment. Belt use and seating position were examined by trimester.Results:There were 427 pregnant occupants identified (weighted n=32 810, 2.6%, SE 12 585, rate 13/1000 person years). The mean age was 24.9 compared with 24.8 years (pregnantvnon-pregnant). Cases were distributed by trimester as follows: first 29.8%, second 36.4%, and third 33.8%. Pregnant women were drivers 70% of the time compared with 71% for non-pregnant women. No belt use was 14% compared with 13% (pregnantvnon-pregnant). Mean injury severity was lower for pregnant women but they were more likely to transported or hospitalized. Improper belt use decreased after the first trimester and there was little change in driver proportion by trimester. Third trimester hospitalization rates increased.Conclusions:Pregnant occupants in crashes have similar profiles of restraint use, driver status, and seat position but different treatment indicators compared to non-pregnant occupants. Trimester status has relatively little impact on crash risk, seating position or restraint use. Undercounting of pregnant cases was possible, even so, 1% of all births were reported to be involved in utero in crashes. Little research has focused on developmental outcomes to infants and children previously involved in exposure to these crashes.
Prevalence of youth access to alcohol or a gun in the home
Authors: Swahn M H , Hammig B J , Ikeda R M 
Published: September 2002

Objectives:To estimate the national prevalence of youth access to alcohol, a gun, or both alcohol and a gun, in their home and to describe the demographic characteristics associated with access to either alcohol or a gun.Methods:Cross sectional data from the 1995 in-home survey of the National Longitudinal Study of Adolescent Health, which used a nationally representative randomly selected school based sample (n=18 924) of adolescents in grades 7–12, were analyzed. The current analyses were restricted to those adolescents 12–18 years of age (n=18 454). Crude logistic regression analyses was used to determine the demographic characteristics associated with access to alcohol or a gun in the home.Results:Overall, 28.7% of US adolescents reported having easy access to alcohol in the home. Availability of alcohol was associated with race/ethnicity, mother’s education, family structure, and welfare status. Similarly, 24.3% of US adolescents reported easy access to a gun in the home. Availability of a gun in the home was associated with gender, race/ethnicity, mother’s education, family structure, and welfare status. Among those that reported that a gun was available in their home, most reported availability of a shotgun (63.0%) followed by a rifle (61.3%), handgun (57.3%), and other gun (16.4%). Ten per cent of adolescents reported availability of both alcohol and a gun in their home.Conclusions:One quarter of US adolescents reported easy access to either alcohol or a gun in their home. Given the risks associated with the misuse of alcohol and guns among adolescents, efforts to increase public awareness of the availability of alcohol and guns in the home are needed.
Do criminals go to the hospital when they are shot?
Authors: May J P , Hemenway D , Hall A 
Published: September 2002

Objectives:To determine whether criminals go to the hospital when they are shot. Such information is needed to check on the accuracy of using hospital emergency room data to estimate non-fatal gunshot wounds.Setting:Five jails across the US.Methods:A survey of inmates being booked into jail, administered by in-house health care staff.Results:Over 90% of over 300 criminals who had been wounded sometime before their incarceration reported going to a hospital for treatment after being shot. These results are consistent with previous findings from one jail.Conclusions:Jail inmates who had previously been shot were likely to have been treated in a hospital. This limited finding is consistent with the proposition that hospital/emergency department data may miss only a small percentage of gunshot wounds to criminals.
STABILITY OF INFORMATION GRANULATION AND INFORMATION GRANULES
Authors: PEDRYCZ WITOLD , VUKOVICH GEORGE 
Published: September 2002

In this study, we introduce a notion of stability of information granules. Granulation of information results in a series of chunks of information usually referred to as information granules. Information granules are basic building entities involved in the formation of a broad class of systems. Information granules are percepts — entities being perceived by humans as being essential when working with some real-world phenomena, especially describing and interacting with them. The percepts need to be comprehensible. They should also reflect the experimental evidence. All in all, they should be stable meaning that they are conceptual entities that reconcile experimental reality with the subjective and ultimately observer-based judgment about the environment. Once being stable, information granules could be viewed as architecture-independent. The proposed algorithmic environment supporting this concept dwells on the ideas of statistical inference that helps quantify stability through a nonparametric testing. The χ2 goodness-of-fit test is used here as a validation mechanism. First, the study elaborates on the formation of information granules and concentrates on the descriptive and prescriptive ways of their design. In the sequel, it is revealed how these two ways interact with the construction of stable information granules. A number of experimental studies are also included.
DIE ENTWICKLUNG DER EPISTOLOGRAPHIE VOM FRÜHEN ISLAM BIS ZUM 4./10. JAHRHUNDERT
Authors: Hachmeier Klaus 
Published: September 2002

AbstractFrom the 4th/10th century onwards, large numbers of letters (arab. rasā'il, the common distinction is between dīwānīyāt, "chancery letters", and ikhwānīyāt, "letters between friends") have survived to our time, both in letter collections and other works (e.g., literary anthologies). The survival of so many letters from the writers of the Buyid period stands in constrast to the earlier Islamic centuries from which relatively few letters have survived, although it had been customary among high-ranking scribes to collect and publish their letters from late Umayyad times onwards. This study examines how letters were treated: (a) in early works of literary criticism; (b) in the so-called adab al-kātib literature (scribe manuals); and (c) in literary anthologies (florilegia). In all three areas, it is possible to trace a growing "literarization" that resulted in the emergence of a so-called ornate prose style that came to dominate Arabic epistolography in the 4th/10th century.
A Nanostructured Hybrid Material Synthesized by the Intercalation of Porphyrin into Layered Titanoniobate
Authors: Tong Zhiwei , Shichi Tetsuya , Oshika Koji , Takagi Katsuhiko 
Published: September 2002

Abstract
The hybridization of 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)-21H,23H-porphin (TMPyP4+) into layered titanoniobate (KTiNbO5), and its structure were studied by means of X-ray diffraction, IR, and polarized and diffuse reflectance UV-vis spectroscopic investigations. The porphyrin molecules incorporated within the intercalation hybrid compound obtained through an intermediary PrNH3+-TiNbO5 hybrid were found to be oriented with a tilt of 46° in a stacked alignment.
Novel Alkali Metal Ionic Liquids: N-Ethylimidazolium Alkali Metal Sulfates
Authors: Ogihara Wataru , Yoshizawa Masahiro , Ohno Hiroyuki 
Published: September 2002

Abstract
Novel ionic liquids containing alkali metal ions as component were prepared by the neutralization of N-ethylimidazole with various kinds of hydrogensulfates (MHSO4; M=Li, Na, or K). All salts were obtained as transparent viscous liquids at room temperature. These ionic liquids showed ionic conductivity higher than 10−4 S cm−1 at room temperature, reflecting low glass transition temperature of below −60 °C. This is the first report on alkali metal salts which are inherently liquid state at room temperature.
Fabrication of Nano-structure by Diels–Alder Reaction
Authors: Matsubara Seijiro , Yamamoto Hiromasa , Oshima Koichiro , Mouri Emiko , Matsuoka Hideki 
Published: September 2002

Abstract
A dip-pen nanolithography was applied to Diels–Alder reaction and fabricated nano-lines made of organic molecules.
Use of α-Allyloxy-α-trimethylsiloxyacetate for Reductive Imino Aldol Reaction Promoted by Titanium Tetraiodide: A Rapid Access to β-Amino-α-hydroxy Esters
Authors: Shimizu Makoto , Sahara Tetsuya 
Published: September 2002

Abstract
Under the influence of titanium tetraiodide the reductive imino aldol reaction of α-allyloxy-α-trimethylsiloxyacetate proceeded with imines to give β-amino-α-hydroxy esters in good yields.
Inhibiting Effects of Trace Amounts of Lanthanum Ion on the Dissolution of Calcite: A Comparative Study on Calcium Carbonate Polymorphs
Authors: Kamiya Natsumi , Kagi Hiroyuki , Notsu Kenji , Tsuno Hiroshi , Akagi Tasuku 
Published: September 2002

Abstract
A significant inhibiting effect was observed on the dissolution of calcite by addition of 5 μM lanthanum ion to the solution, whereas no inhibition was observed both for aragonite and vaterite under the same conditions. In situ AFM (atomic force microscopy) images suggested that micro-precipitates depositing at the step site of calcite inhibited the dissolution in the lanthanum-doped solution. The solubility-calculation for the given solution was consistent with lanthanum carbonate being the micro-precipitate.
Asymmetric Diels–Alder Reactions Catalyzed by Chiral Ni(II)-Binaphthyldiimine Complexes
Authors: Suga Hiroyuki , Kakehi Akikazu , Mitsuda Masashi 
Published: September 2002

Abstract
Ni(II)-N,N′-Bis(2-quinolylmethylene)-1,1′-binaphthyl-2,2′-diamine complex was found to be an efficient chiral Lewis acid catalyst for asymmetric Diels–Alder reactions (endo: up to 94% ee) between cyclopentadiene (1) and 3-alkenoyl-2-oxazolidinones (2). In the presence of Ni(II) catalyst (1 mol%), the reaction between cyclopentadiene and 3-acryloyl-2-oxazolidinone proceeded smoothly (85% yield) at −40 °C with high enantioselectivity (endo: 90% ee).
Control of the Production Amount and Polymorphism of Calcium Carbonate by Biomimetic Mineralization
Authors: Shimomura Noriyuki , Ohkubo Naoki , Ichikawa Kazuhiko 
Published: September 2002

Abstract
The cooperation between carbonic anhydrase (CA) or some biomimetic zinc model compound as a catalyst for the conversion from CO2 to HCO3− and poly(l-aspartate) as calcium ion recognition sites induced the aragonite formation of calcium carbonate. The higher CA-arising activity promoted the calcium carbonate production amount.