bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiac morphology and blood pressure in the adult zebrafish
Authors: Hu Norman , Yost H. Joseph , Clark Edward B. 
Published: September 2002

AbstractZebrafish has become a popular model for the study of cardiovascular development. We performed morphologic analysis on 3 months postfertilization zebrafish hearts (n ≥ 20) with scanning electron microscopy, hematoxylin and eosin staining and Masson's trichrome staining, and morphometric analysis on cell organelles with transmission electron photomicrographs. We measured atrial, ventricular, ventral, and dorsal aortic blood pressures (n ≥ 5) with a servonull system. The atrioventricular orifice was positioned on the dorsomedial side of the anterior ventricle, surmounted by the single‐chambered atrium. The atrioventricular valve was free of tension apparati but supported by papillary bands to prevent retrograde flow. The ventricle was spanned with fine trabeculae perpendicular to the compact layer and perforated with a subepicardial network of coronary arteries, which originated from the efferent branchial arteries by means of the main coronary vessel. Ventricular myocytes were larger than those in the atrium (P < 0.05) with abundant mitochondria close to the sarcolemmal. Sarcoplasmic reticulum was sparse in zebrafish ventricle. Bulbus arteriosus was located anterior to the ventricle, and functioned as an elastic reservoir to absorb the rapid rise of pressure during ventricular contraction. The dense matrix of collagen interspersed across the entire bulbus arteriosus exemplified the characteristics of vasculature smooth muscle. There were pressure gradients from atrium to ventricle, and from ventral to dorsal aorta, indicating that the valves and the branchial arteries, respectively, were points of resistance to blood flow. These data serve as a framework for structure‐function investigations of the zebrafish cardiovascular system. Anat Rec 264:1–12, 2001. © 2001 Wiley‐Liss, Inc.
Localization of luteinizing‐hormone releasing hormone binding sites in the gastric mucosa of suckling rats
Authors: Gama Patrícia , Alvares Eliana Parisi 
Published: September 2002

AbstractLuteinizing‐hormone releasing hormone (LHRH) is a hypothalamic and milk‐borne hormone that inhibits the cell proliferation of gastric epithelium in developing rats, although the mechanism of such action is unknown. We investigated the presence of binding sites for LHRH in the stomach of suckling rats after the injection of the hormone. Immunofluorescence at the confocal microscopy level revealed that LHRH binds to gastric cells, being particularly abundant over the gland. Different fluorescent lectins were used to identify gastric cell types and determine which were labeled by the hormone. Colocalization studies in these double‐labeling experiments showed that LHRH staining colocalizes with parietal cells, suggesting the presence of binding sites in these cells. The three‐dimensional (3‐D) reconstruction of isolated parietal cells revealed the localization of the signal, which appears to be in the membrane of the canalicular region. These results suggest that there are binding sites for LHRH in the gastric epithelium, specifically in parietal cells, and they might play a role in the control of cell proliferation during suckling. Anat Rec 264:43–50, 2001. © 2001 Wiley‐Liss, Inc.
A cellular survival switch: poly(ADP‐ribosyl)ation stimulates DNA repair and silences transcription
Authors: Ziegler Mathias , Oei Shiao Li 
Published: September 2002

AbstractPoly(ADP‐ribosyl)ation is a post‐translational modification occurring in the nucleus. The most abundant and best‐characterized enzyme catalyzing this reaction, poly(ADP‐ribose) polymerase 1 (PARP1), participates in fundamental nuclear events. The enzyme functions as molecular “nick sensor”. It binds with high affinity to DNA single‐strand breaks resulting in the initiation of its catalytic activity. Activated PARP1 promotes base excision repair. In addition, PARP1 modifies several transcription factors and thereby precludes their binding to DNA. We propose that a major function of PARP1 includes the silencing of transcription preventing expression of damaged genes. Concomitant stimulation of DNA repair suggests that PARP1 acts as a switch between transcription and DNA repair. Another PARP‐type enzyme, tankyrase, is involved in the regulation of telomere elongation. Tankyrase modifies a telomere‐associated protein and thereby prevents it masking telomeric repeats providing access of telomerase for telomere elongation. Therefore, poly(ADP‐ribosyl)ation reactions may act as molecular switches in DNA metabolism. BioEssays 23:543–548, 2001. © 2001 John Wiley & Sons, Inc.
Molecular biology and anatomy of Drosophila olfactory associative learning
Authors: Roman Gregg , Davis Ronald L. 
Published: September 2002

AbstractMost of our current knowledge of olfactory associative learning in Drosophila comes from the behavioral and molecular analysis of mutants that fail to learn. The identities of the genes affected in these mutants implicate new signaling pathways as mediators of associative learning. The expression patterns of these genes provide insight into the neuroanatomical areas that underlie learning. In recent years, there have been great strides in understanding the molecular and neuroanatomical basis for olfaction in insects. It is now clear that much of the association between the conditioned stimuli and the unconditioned stimuli in olfactory learning occurs within mushroom bodies — third order olfactory neurons within the central brain. In this review, we discuss the nature of the behavioral tasks, the molecules, and the neuronal circuits involved in olfactory learning in Drosophila. BioEssays 23:571–581, 2001. © 2001 John Wiley & Sons, Inc.
On‐line size measurement of yeast aggregates using image analysis
Authors: Mas Sandrine , Ghommidh Charles 
Published: September 2002

AbstractAlcohol fermentation productivity can be strongly improved using a flocculation‐based yeast recycle. However, the efficiency of the biomass retention system depends strongly on the yeast particle size. Accordingly, the monitoring and control of yeast floc diameter are of primary importance. The on‐line measurement of mean floc diameter has been achieved using on‐line image analysis, based on the evaluation of image texture. The texture analysis method consisted in the building of a co‐occurrence matrix from which the so‐called “Energy parameter” was extracted. While image texture is usually used for classification purposes, it has been used here as a quantitative descriptor: a correlation has been found between this statistical image feature and off‐line manual floc‐size determinations. In the floc‐size range investigated (|bu 0.5–4.3 mm), the evaluated mean diameter was in good agreement with the actual particle size, with a determination coefficient equal to 0.980. In contrast with manual measurements, slow and tedious, this method gave the value of the mean particle diameter in real‐time, without sampling. This novel tool has been used to investigate the behavior of yeast aggregates as a function of fermentation conditions. While biomass concentration was kept constant, step increases of the feed rate led to a decrease of the mean floc diameter. Image analysis showed that the particle‐size reduction could occur within a few minutes after modification of the medium dilution rate, demonstrating the disruptive effect of the CO2 efflux. The kinetic of aggregate formation was dependent on the gas‐phase composition. Instead of recycling fermentation gas, sparging the fermentor with nitrogen, to reduce dissolved CO2 concentration, increased the rate of floc‐size growth. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 91–98, 2001.
Direct resolution of (±)‐ephedrine and atropine into their enantiomers by impregnated TLC
Authors: Bhushan R. , Martens J. , Arora Meenakshi 
Published: September 2002

AbstractDirect resolution of (±)‐ephedrine and atropine into their enantiomers was achieved by normal‐phase thin layer chromatography on silica gel plates impregnated with optically pure L‐tartaric acid and L‐histidine, respectively, as chiral selectors. The mobile phases enabling successful resolution were different combinations of acetonitrile–methanol–water. The spots were detected with iodine vapours and the detection limits were 2 and 6 µg, respectively, in terms of the racemate. The effects of concentration of the impregnating reagent, temperature and pH on resolution have been studied. Copyright © 2001 John Wiley & Sons, Ltd.
First synthesis of the two enantiomers of α‐methyldiphenylalanine [(αMe)Dip] by HPLC resolution
Authors: Royo Soledad , López Pilar , Jiménez Ana I. , Oliveros Laureano , Cativiela Carlos 
Published: September 2002

AbstractA strategy for the preparation of enantiomerically pure (R)‐ and (S)‐α‐methyldiphenylalanine, constrained phenylalanine analogs, is described. A racemic precursor was prepared in high yield from easily available starting products and subjected to HPLC resolution on a noncommercial chiral stationary phase. More than 600 mg of each enantiomer was isolated in optically pure form by using a 150 × 20 mm ID column containing mixed 10‐undecenoate/3,5‐dimethylphenylcarbamate of cellulose covalently bonded to allylsilica gel and a mixture of n‐hexane/2‐propanol/acetone as the mobile phase. Chirality 14:39–46, 2002. © 2002 Wiley‐Liss, Inc.
Solvent‐free optical resolution of N‐methylamphetamine by distillation after partial diastereoisomeric salt formation
Authors: Kozma Dávid , Fogassy Elemér 
Published: September 2002

AbstractSolvent‐free optical resolution of N‐methylamphetamine was developed by distillation after partial diastereoisomeric salt formation. From the 18 chiral acids tested by this method, five provide by this method resolution: O,O′‐dibenzoyltartaric acid, O,O′‐di‐p‐toluoyltartaric acid, 6‐methoxy‐α‐methyl‐2‐naphthaleneacetic acid (Naproxen), the cis‐permetrinic acid, and the 2‐phenoxypropionic acid. Among them the O,O′‐dibenzoyltartaric acid in water‐free form provided the more effective resolution. The efficiency of this resolution S = 0.74 is in the range of the industrial‐scale resolutions and not worse than the efficiency achieved by optical resolution via fractional crystallization. Chirality 13:428–430, 2001. © 2001 Wiley‐Liss, Inc.
Chiral recognition of dipeptide methyl esters by an anionic β‐cyclodextrin
Authors: Kano Koji , Hasegawa Hideki , Miyamura Muneki 
Published: September 2002

AbstractChiral recognition of dipeptide methyl esters by anionic heptakis[6‐carboxymethylthio‐6‐deoxy]‐β‐cyclodextrin (per‐CO2−‐β‐CD) was studied in D2O at pD 7.0 by means of 1H NMR spectroscopy. The methyl esters of alanylalanine (Ala‐Ala‐OMe), alanylleucine (Ala‐Leu‐OMe), alanyltryptophan (Ala‐Trp‐OMe), glycyltryptophan (Gly‐Trp‐OMe), valyltryptophan (Val‐Trp‐OMe), leucyltryptophan (Leu‐Trp‐OMe), and tryptophylalanine (Trp‐Ala‐OMe) were used as the dipeptides. The binding constant (K) determined from NMR titration increases in the order Ala‐Ala‐OMe < Ala‐Leu‐OMe < Ala‐Trp‐OMe, suggesting that van der Waals interactions between the host and the guest participate in complexation. Coulomb interactions between the protonated dipeptide methyl esters and the anionic host seem to be another attractive force. Per‐CO2−‐β‐CD interacts with the (R,R)‐enantiomers of the dipeptide methyl esters more strongly than the (S,S)‐enantiomers. Such enantioselectivity corresponds to that for α‐amino acid methyl esters such as Leu‐OMe and Trp‐OMe, whose (R)‐enantiomers are the preferable guests. The enantioselectivity is mainly dominated by amino acid residue at the C‐terminal and chirality at the N‐terminal residue plays an assistant role. An asymmetrically twisted shape of the host cavity may be essential for chiral recognition. Chirality 13:474–482, 2001. © 2001 Wiley‐Liss, Inc.
Geochemical evolution of amino acids in dentine of pleistocene bears
Authors: De Torres Trinidad , Ortiz José E. , García María J. , Llamas Juan F. , Canoira Laureano , García De La Morena Miguel A. , Juliá Ramón 
Published: September 2002

AbstractA linear correlation was established between aspartic acid racemization ratio from cave bear dentine collagen and absolute dating. The high correlation coefficient obtained allowed age calculation through amino acid racemization. Aspartic acid and glutamic acid racemization kinetics have also been explored in dentine from a North American black bear (Ursus americanus Pallas). Three sample sets were prepared for kinetic heating experiments in nitrogen atmosphere: one water soaked, one with a water‐saturated nitrogen atmosphere, and one without any moisture. It was possible to show that the presence of water is a factor controlling amino acid racemization rate. The aspartic acid in a heating experiment at 105°C shows an “apparent kinetics reversal” which can be explained by a progressive hydrolysis of amino acid chains (proteins and polypeptides). Because of the low potential of collagen preservation over long periods of time, the apparent kinetics reversal phenomenon will not affect the dating of old material where no traces of collagen remain. An apparent kinetics reversal was not observed in glutamic acid, which racemizates more slowly. Chirality 13:517–521, 2001. © 2001 Wiley‐Liss, Inc.
Micellar electrokinetic capillary chromatography determination of (+)S and (−)R arotinolol in serum using UV detection and solid phase extraction
Authors: Hefnawy Mohammed M. 
Published: September 2002

AbstractA method for the simultaneous determination of (+)S and (−)R arotinolol in serum by micellar electrokinetic capillary chromatography is described. Stereoselective resolution of the arotinolol enantiomers was achieved using 5 mM sodium taurocholate in 10 mM sodium dihydrogen phosphate buffer of pH 2.5. A 72‐cm uncoated fused‐silica capillary at a constant voltage of 15 kV was used for the analysis. The analytes of interest were extracted from serum using solid phase extraction. An octadecyl cartridge gave good recoveries in excess of 87% for both (+)S and (−)R arotinolol without any interference. The calibration curves were linear over the range of 50–500 ng ml−1 with (+)S propranolol as the internal standard and the coefficient of determination was greater than 0.999 (n = 3). The limit of quantitation was 50 ng ml−1 for each enantiomer and the detection limit using 1 ml serum and a UV detection set et 220 nm was 25 ng ml−1 (S/N = 2). Precision and accuracy of the method were in the range 0.8–2.7% and 1.2–6.4%, respectively, for (+)S arotinolol and 1.1–3.9% and 2.2–6.5%, respectively, for (−)R arotinolol. Chirality 14:67–71, 2002. © 2002 Wiley‐Liss, Inc.
Colour‐difference evaluation using CRT colours. Part I: Data gathering and testing colour difference formulae
Authors: Cui Guihua , Luo M. Ronnier , Rigg B. , Li Wei 
Published: September 2002

AbstractA large set of colour discrimination data based upon Cathode Ray Tube (CRT) colours was accumulated. The experiment was carried out to study the effect of changes in viewing parameters on perceived colour differences. It was divided into sixteen phases. Each phase was conducted under a different set of experimental conditions including different sample sizes, backgrounds, frames, widths, and colours of separation between pairs of samples. For each phase, 134 pairs of colours with average 2.7 CIELAB colour difference were studied. The colours closely corresponded to the five colour centers proposed by the CIE. Each pair was assessed by 10 or 20 observers using the gray scale method. The visual results from the present study were also used to test six colour‐difference formulae: CIELAB, CMC, BFD, CIE94, LCD, and CIEDE2000. The latter outperformed the other formulae and is the new CIE colour‐difference equation. The current results were also compared with the other datasets based upon surface colours. The present results are consistent with those obtained for surface colours. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 394–402, 2001
The validity of the trans‐theoretical model of behaviour change to investigate motivation to change among child molesters
Authors: Tierney David W. , McCabe Marita P. 
Published: September 2002

AbstractMotivation for behaviour change is considered a crucial issue in the treatment of sex offenders, including child molesters. However, there has been no systematic investigation of this issue. This paper reviews the validity of the constructs of the Trans‐theoretical Model of Behaviour Change to act as a framework to investigate motivation for behaviour change among child molesters. Constructs within this theory are the Stages of Change, Processes of Change and Decisional Balance. The utility of these constructs to act as a framework to investigate motivation among child molesters is assessed by reviewing their utility as measures of motivation for behaviour change generally, and by reviewing their relevance to child molesters. It is concluded that the constructs of the Trans‐theoretical Model of Behaviour Change are valid measures of motivation and have some general relevance to child molesters. It is therefore concluded that they have some utility to investigate motivation to change among child molesters. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of Ki‐ras gene mutations associated with DNA diploid, aneuploid, and multiploid colorectal carcinomas using a crypt isolation technique
Authors: Sugai Tamotsu , Habano Wataru , Nakamura Shin‐ichi , Jiao Yu‐Fei , Higuchi Taro , Inomata Masaaki , Chiba Toshimi 
Published: September 2002

AbstractBackground and Aim: Current evidence suggests a possible relationship between DNA ploidy status and Ki‐ras gene mutations in human cancers. However, the conventional method does not enable accurate determination of DNA ploidy status of a tumor cell. The present study attempts to clarify whether Ki‐ras gene mutations are associated with DNA ploidy status in sporadic colorectal carcinomas using a crypt isolation technique coupled with DNA cytometric sorting. Methods: Polymerase chain reaction and single‐strand conformation polymorphism and direct sequencing were used to analyze Ki‐ras gene mutations in 82 sporadic colorectal carcinomas: 21 diploid, 12 aneuploid, and 49 multiploid. In addition, microsatellite instability (MSI) was assessed using seven microsatellite markers to study the relationship to Ki‐ras mutations. Results: Ki‐ras mutations were found in 12 of 21 diploid carcinomas and in 8 of 12 aneuploid carcinomas. In contrast, Ki‐ras gene mutations were detected infrequently in the 34 multiploid carcinomas examined, 8 of which were seen in diploid populations and 10 in aneuploid populations. On the other hand, Ki‐ras gene mutations were inversely correlated with MSI, which was found in diploid carcinomas only. Conclusions: The low frequency of Ki‐ras gene mutations that we observed in multiclonal colorectal carcinomas suggests that development of multiclonal colorectal carcinoma may involve a mechanism different from that involved in the development of diploid or aneuploid colorectal carcinomas. Cytometry (Comm. Clin. Cytometry) 46:345–350, 2001. © 2001 Wiley‐Liss, Inc.
ATP release from the electric organ of Torpedo and from Xenopus oocytes
Authors: Escalada Artur , Aleu Jordi , Bodas Elena , Martín‐Satué Mireia , Felipe Antonio , Marsal Jordi , Gómez de Aranda Inmaculada , Pujol Gemma , Solsona Carles 
Published: September 2002

AbstractA field‐stimulated electric organ generated an electric field and release of a large quantity of ATP. Oocytes injected with mRNA from a Torpedo electric organ released ATP when stimulated with carbamylcholine. We set up a configuration recording that let us simultaneously monitor the oocyte ionic currents and ATP release from a single oocyte. Hyperpolarization pulses applied to Xenopus oocytes induced an inward current and release of ATP independently of the expression of the ClC‐0 chloride channel. The current was insensitive to substitution of ions in the extracellular saline solution, either anions or cations. The reversal potential of the current was established between +40 and +100 mV, which is in the same range as the equilibrium potential of ATP–4. There was a correlation between the magnitude of the inward current and the amount of ATP released. The inward current closed slowly. During this closing period there was still release of ATP, which is sensitive to the holding potential. Positive potentials cut the amount of ATP released. The evoked current and ATP release were both sensitive to inhibitors of E‐NTPDase activity, such as suramin, 4‐acetamido‐4′isothiocyanatostilbene‐2,2′‐disulfonic acid (SITS), 4,4′diisothiocyanatostilbene‐2′‐disulfonic acid (DIDS), and a high concentration of calcium and gadolinium ions. The expression of CD39 increased the size of the hyperpolarizing induced current. By reverse transcription polymerase chain reaction, we found a protein homologous to CD39. The relationship between the results obtained in the electric organ and oocytes is that, in both cases, stimulation or hyperpolarization causes a change in the intracellular ion concentration, producing an osmotic stress, which, in turn, triggers ATP release. Stimulation or hyperpolarization may alter the intercellular ion concentration, leading to osmotic stress and the release of ATP in both electric organ and oocytes. Drug Dev. Res. 52:34–43, 2001. © 2001 Wiley‐Liss, Inc.
TGF‐β1 perturbs vascular development and inhibits epithelial differentiation in fetal lung in vivo
Authors: Zeng Xin , Gray Mary , Stahlman Mildred T. , Whitsett Jeffrey A. 
Published: September 2002

AbstractMembers of the transforming growth factor β (TGF‐β) family of polypeptides have been implicated in morphogenesis and differentiation in numerous tissues, including the lung. In order to further define effects of TGF‐β signaling in lung morphogenesis, a constitutively active form of TGF‐β1 was expressed in respiratory epithelial cells of the fetal mouse lung in vivo. Expression of TGF‐β1 arrested lung morphogenesis in the pseudoglandular stage of development, inhibiting synthesis of differentiation‐dependent proteins, SP‐B, SP‐C, and CCSP, and maintaining embryonic patterns of staining for thyroid transcription factor‐1 (TTF‐1) and hepatocyte nuclear factor‐3β (HNF‐3β). The pulmonary mesenchyme was thickened and vascular density was increased by TGF‐β1. TGF‐β1 decreased expression of vascular endothelial growth factor‐A (VEGF‐A) mRNA and protein, and the abundance of Flk‐1 mRNA in the lung mesenchyme. Distribution of platelet‐endothelial cell adhesion molecule (PECAM)‐1, a marker of pulmonary blood vessels, was altered, and ultrastructural studies demonstrated that TGF‐β1 inhibited vascular development in the fetal lung. TGF‐β1 perturbed both epithelial cell differentiation and formation of the pulmonary vasculature, supporting the concept that precise control of signaling via the TGF‐β receptor pathway is critical for normal lung morphogenesis. © 2001 Wiley‐Liss, Inc.
Continuous ambient‐vibration monitoring of the arch dam of Mauvoisin
Authors: Darbre Georges R. , Proulx Jean 
Published: September 2002

AbstractThis paper presents the experimental programme and results of a continuous ambient vibrations recording programme carried out on the 250 m arch dam of Mauvoisin. This project follows a series of previous measurements completed for seven different water levels. An automated system was set up on the dam and the ambient vibrations were recorded twice daily for a period of 6 months. Frequency shifts were tracked throughout the testing period and the effects of the varying water level were identified. The results confirmed the behaviour observed in previous ambient‐ and forced‐vibration tests. The added‐mass effects are overcome by the stiffening of the dam due to increasing hydrostatic pressure for lower reservoir levels. This trend is then reversed for higher water levels. Any temperature‐related effects were not identified. The experimental techniques are briefly described and the frequency identification process and its limitations are discussed. Copyright © 2001 John Wiley & Sons, Ltd.