bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature modulation of the kinetics of phosphoglucose isomerase genetic variants from the sea anemone Metridium senile
Authors: Hoffmann Richard J. 
Published: June 2005

AbstractThe allozymes involved in a one‐locus, two‐allele polymorphism for phosphoglucose isomerase from populations of the sea anemone Metridium senile from the northeast coast of North America exhibit different heat stabilities. The electrophoretically slow form is more stable than the fast, whether or not the enzyme is protected by added 6‐phosphogluconate. In addition, Km of glucose‐6‐phosphate (G6P) values are significantly higher for the slow than for the fast allozyme, the reverse of the situation in the gluconeogenic direction. Km of G6P values for the mixture of isozymes produced by heterozygotes fall intermediate between those for the two homozygotes. All genotypes produce enzymes that have slightly U‐shaped Km vs. temperature curves; these patterns result in differences in thermal sensitivity of reaction rates at low substrate concentrations between high and low temperature ranges. The fast allozyme has higher Vmax values than the slow at all environmentally realistic temperatures. These kinetic differences in the glycolytic direction result in higher Vmax/Km ratios for the fast than for the slow allozyme at all tested temperatures, with the greatest absolute difference falling at 25°C; again, the heterozygote is intermediate. These kinetic differences may yield increased adaptation to thermal aspects of the environment.
Environmental control of the annual gonadal cycle of Fundulus heteroclitus L.: The pineal organ and eyes
Authors: Day Jonathan R. , Taylor Malcolm H. 
Published: June 2005

AbstractFemale fish collected in winter, spring, or summer were subjected to pinealectomy, eye enucleation, or both, and maintained on short days (LD 9:15) or long days (LD 15:9) at 20°C. Sexual maturity (gonadosomatic index and occurrence of vitellogenesis) was determined after 6 weeks of exposure to the experimental light regimes. The fish subjected to surgical manipulations were capable of perceiving stimulatory or inhibitory photoperiods regardless of whether they were blinded, pinealectomized, or both. Pinealectomized fish did not remain sexually active when exposed to short days. From these results we conclude that an extraretinal nonpineal photoreceptor can influence seasonal reproduction in Fundulus heteroclitus. We were unable to demonstrate an essential photoreceptive or endocrine role of the pineal organ in reproduction in this species.
A comparison of β‐endorphin levels in regenerating and nonregenerating vertebrates
Authors: Vethamany‐Globus Swani , Globus Morton , Milton Guy 
Published: June 2005

AbstractThe mean plasma level of β‐endorphin in the newt, Notoph‐thalmus viridescens, as measured by radioimmunoassay, is significantly higher than the circulating levels of β‐endorphin in the anuran, Rana pipiens, and in mammals (humans and mice). The newt β‐endorphin level is found to be 6‐fold greater than mammalian levels and three times greater than the levels observed in Rana pipiens. The high levels are maintained in the newt throughout limb regeneration.
Neuron number and asynchronous hindlimb development during the period of profound cell loss in the lateral motor column of Rana pipiens larvae
Authors: Stebbins Cathy A. , Pollack Emanuel D. 
Published: June 2005

AbstractAlthough the effects of peripheral manipulations on the developing lateral motor column (LMC) in the spinal cord have been widely reported, few investigations have focused on the relationship between the limb and the LMC during the time when the greatest amount of naturally occuring motor neuron death is taking place. In the present study, asynchronous hindlimb development, induced by partial amputation followed by regeneration of one hindlimb bud of Rana pipiens tadpoles, resulted in an unexpected response by the lumbosacral LMC during the period of rapid cell loss. An analysis of neuron counts and their distribution at the onset of cell reduction revealed that the LMC of the operated side of asynchronous‐limbed animals differentiated at least one developmental stage (Taylor and Kollros stages, '46) beyond the stage of the tadpole as indicated by the morphology of the unoperated limb. The LMC of the unoperated side of the same animal was delayed at least one stage relative to the limb it innervated. The results suggest that the regenerated limb differentiated as a combination of a normally progressing intact proximal stump and a developmentally delayed distal regenerate, both of these regions being reflected in the LMC neuron counts, while slowed development of the LMC on the unoperated side can be attributed to transneuronal effects.
Whole eyes reconstituted from embryonic half anlagen: Alterations in donor‐derived territories in Xenopus pigment chimerae
Authors: Conway Kevin M. , Hunt R. Kevin 
Published: June 2005

AbstractGrafts from pigmented donor embryonic eye rudiments into albino hosts were used to chart i) fates of local cell groups in three positions in whole eye rudiments, and ii) alterations in graft‐derived territories when the posterior half of the rudiment was ablated. Small pigmented patches of graft‐derived tissue were conspicuous in albino embryos and tadpoles, enabling us to directly monitor their location and size in the eyes of living animals. The three (right eye) positions marked by pigmented grafts were dorsal (12 o'clock), anterior (3 o'clock), and anteroventral (5 o'clock). Control transplants reared without secondary ablation produced black sector territories in pigment retinal epithelium and iris at corresponding 12 o'clock or 2 o'clock or 4 o'clock positions on the larval eyeball. In the experimental series posterior half‐anlagen were ablated. The remaining anterior half‐anlagen, each containing a pigmented graft, reconstituted spherical larval eyeballs of reduced size. During healing, donor‐derived pigmented sector territories remained coherent, but were altered in position and size compared to controls. Dorsal cells (from 12 o'clock grafts) appeared to move rapidly along the newly formed cut edge into the wound and went on to form expanded black sectors in posterior eye regions. More gradually, sector territories of anterior cells (3 o'clock grafts) and anteroventral cells (5 o'clock grafts) shifted toward dorsal in a counterclockwise direction. Thus all three types of graft derived pigment territories were altered in eye anlage fragments as they healed to form half‐size spherical eyes.
Physiological response to manual restraint of wild impala
Authors: Hattingh J. , Pitts N. I. , Ganhao M. F. , Carlston A. 
Published: June 2005

AbstractThe physiological response resulting from manual restraint in veld and bomakept impala was investigated by determining haematocrit, lactate, glucose, total protein and lipid, osmolarity, cortisol, and catecholamine values at times 0, 5, and 10 minutes. Blood was also obtained at time 10 from animals manually restrained but without repetitive sampling. The results indicate that manual restraint resulted in a physiological response in both veld and boma‐kept animals but that the reactions were different depending on whether the impala were naive. In addition, repetitive blood sampling did not aggravate the response.
Synthesis of [14C]‐radiolabelled entecavir
Authors: Ogan Marc D. , Kucera David J. , Pendri Yadagiri R. , Kent Rinehart J. 
Published: June 2005

AbstractRadiolabelled [14C]entecavir, (1), was prepared in 12 steps from (1S,2R,3S,5R)‐3‐(benzyloxy)‐2‐(benzyloxymethyl)‐6‐oxa‐bicyclo[3.1.0]hexane 2. The chemical yield of [14C]entecavir was 14% from the epoxide 2. Introduction of [14C] radiolabel was achieved by elaboration of 4,5‐diaminopyrimidine 8 with triethyl[14C]orthoformate to purine derivative 9. The radiochemical yield of [14C]entecavir from triethyl[14C]orthoformate was 11.3%. Radiochemical purity of [14C]entecavir determined by HPLC was 99.8%. The specific activity of [14C]entecavir was 108 µCi/mg (29.9 mCi/mmol). Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and evaluation of [11C]RU40555, a selective glucocorticoid receptor antagonist
Authors: Matsuya Takahiro , Takamatsu Hiroyuki , Murakami Yoshihiro , Noda Akihiro , Osoda Kazuhiko , Ichise Rikiya , Awaga Yuji , Nishimura Shintaro 
Published: June 2005

Abstract We demonstrated the synthesis of carbon‐11 labeled 17‐α‐hydroxy‐11‐β‐/4‐/[methyl]‐[1‐methylethyl]‐aminophenyl/‐17α‐[prop‐1‐ynyl]esta‐4‐9‐diene‐3‐one (RU40555), a selective glucocorticoid receptor (GR) antagonist, and examined the in vivo profile of [11C]RU40555. [11C]RU40555 was synthesized by direct N‐methylation with [11C]CH3OTf at 60°C for 5 min and an injectable solution of [11C]RU40555 was obtained in 31 min at the end of bombardment. The decay‐corrected radiochemical yield was 19%, the specific radioactivity was 57.5±14.0 GBq/µmol, and the radiochemical purity was more than 99% as determined by HPLC. In rat experiments, the effects of adrenalectomy (ADX) on brain accumulation of [11C]RU40555 were examined. ADX significantly decreased plasma corticosterone levels, and significantly increased brain accumulation of [11C]RU40555. We succeeded in developing a rapid automated synthesis method for [11C]RU40555, a GR antagonist, and showed [11C]RU40555 had a potential as a PET tracer for mapping GR. Copyright © 2005 John Wiley & Sons, Ltd.
A novel method for the synthesis of carbon‐14‐labeled N‐[3‐(1‐methyl‐4‐piperidinyl)‐1H‐pyrrolo[3,2‐b]pyridin‐5‐yl]propanamide and its use in quantitative whole‐body autoradiography studies
Authors: Wheeler William J. , Chay Sylvia H. , Herman Jennifer L. , O'Bannon Douglas D. 
Published: June 2005

AbstractSumitriptan (1), a non‐selective 5‐HT1B/1D agonist is an effective therapeutic agent for the acute treatment of migraine, but it is contraindicated for use in patients with known heart disease. The first Selective Serotonin One F Receptor Agonist (SSOFRA), 5‐(4′‐fluorobenz‐amido)‐3‐(N‐methyl‐piperidin‐4‐yl)‐1H‐indole (2) was demonstrated to be clinically useful in the treatment of migraine. Although 2 exhibited high affinity for the 5‐HT1F receptor as well as high selectivity for the 5‐HT1F receptor relative to 5‐HT1B and 5‐HT1D receptors, it demonstrated appreciable affinity for the 5‐HT1A receptor. Subsequently, a program was launched to discover SSOFRA's with improved selectivity over other 5‐HT1 receptor subtypes. As a result of these efforts, N‐[3‐(1‐methyl‐4‐piperidinyl)‐1H‐pyrrolo[3,2‐b]pyridin‐5‐yl]propanamide (3) was found to possess greater than 100‐fold selectivity over 5‐HT1A, 5‐HT1B and 5‐HT1D receptors. Pursuant to a potential clinical investigation of 3, its carbon‐14‐labeled isotopomer has been prepared by a circuitous route from unlabeled 3 and used in quantitative whole‐body autoradiography studies in rats. The results of these efforts are reported herein. Copyright © 2005 John Wiley & Sons, Ltd.
Microglia in health and disease
Authors: Kim Seung U. , de Vellis Jean 
Published: June 2005

AbstractMicroglia, one of three glial cell types in the central nervous system (CNS), play an important role as resident immunocompetent and phagocytic cells in the CNS in the event of injury and disease. It was del Rio Hortega in 1927 who determined that microglia belong a distinct glial cell type apart from astrocytes and oligodendrocytes, and since 1970s there has been wide recognition that microglia are immune effectors in the CNS that respond to pathological conditions and participate in initiation and progression of neurological disorders including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and acquired immune deficiency syndrome dementia complex by releasing potentially cytotoxic molecules such as proinflammatory cytokines, reactive oxygen intermediates, proteinases and complement proteins. There is also evidence to suggest that microglia are capable of secreting neurotrophic or neuron survival factors upon activation via inflammation or injury. It is thus timely to review current status of knowledge on biology and immunology of microglia, and consider new directions of investigation on microglia in health and disease. © 2005 Wiley‐Liss, Inc.
Thermal and vibrational studies of propylenediammonium hexachlorobismuthate dihydrate, [NH3(CH2)3NH3]3(BiCl6)2·2H2O
Authors: Ouasri A. , Jeghnou H. , Rhandour A. , Dhamelincourt M. C. , Dhamelincourt P. , Mazzah A. , Roussel P. 
Published: June 2005

AbstractDifferential scanning calorimetric and coupled thermal differential and thermogravimetric analysis studies of propylenediammonium hexachlorobismuthate dihydrate, [NH3(CH2)3NH3]3(BiCl6)2·2H2O2, crystals are reported. This compound undergoes dehydration at high temperatures. The infrared and Raman spectra were measured at room temperature and were interpreted on the basis of literature data. There is evidence in the temperature‐dependent Raman spectra of the dehydration of this compound and it is found that the vibrational modes of both the anion and cation are influenced by it. Copyright © 2005 John Wiley & Sons, Ltd.
RP‐HPLC analysis of phenolic compounds and flavonoids in beverages and plant extracts using a CoulArray detector
Authors: Jandera Pavel , Škeříková Veronika , Řehová Lucie , Hájek Tomáš , Baldriánová Lucie , Škopová Gabriela , Kellner Vladimír , Horna Aleš 
Published: June 2005

AbstractMethods were developed for the analysis of natural antioxidants including phenolic compounds and flavonoids in beverages and plant extracts using gradient HPLC with multi‐channel electrochemical coulometric detection. Suitability of various reversed‐phase columns for this purpose was compared; pH and mobile phase gradients were optimized with respect to the separation selectivity and sensitivity of detection. Because of different target compounds in various sample types, the overlapping resolution maps and the normalized resolution product approaches described earlier were used to select optimum columns and gradients to suit the analysis of the individual sample types. The methods were applied to the analysis of phenolic compounds and flavonoids in beer, wine, tea, and yacon extracts. 32 phenolic compounds were identified and determined, including derivatives of benzoic and cinnamic acids, flavones, and a few related glycosides. Eight‐channel CoulArray detection offers high selectivity and sensitivity with limits of detection in the low μg L–1 range, at least an order of magnitude lower than single‐channel coulometric detection using the Coulochem detector. No special sample pretreatment is necessary and, because of the compatibility of the CoulArray detector with gradient elution, phenolic antioxidants of different polarities can be determined in a single run. In addition to the retention times, the ratios of the areas of the pre‐dominant and post‐dominant peaks to the area of the dominant peak can be used for improved identification of natural antioxidants.
A comparative study of several HPLC methods for determining free amino acid profiles in honey
Authors: Bernal José Luis , Nozal María Jesús , Toribio Laura , Diego Juan Carlos , Ruiz Antonio 
Published: June 2005

AbstractA study of the viability of three derivatizing reagents for obtaining amino acid profiles in honey through high performance liquid chromatography (HPLC) is presented. A method using diode array detection based on a reaction with diethyl ethoxymethylene malonate (DEMM) and two other methods using fluorescence detection based on derivatization with fluorenylmethyl chloroformate (FMOC‐Cl) and 6‐aminoquinolyl‐N‐hydroxysuccinimidyl carbamate (AQC) have been developed. The three methods yield detection limits close to the ppb level, but vary in relation to other analytical characteristics. The use of methyl chloroformate derivatives allows the profile to be obtained with the greatest sensitivity within a short time frame. On applying such methods to honey samples of diverse botanical origin, we observe that the proline values obtained are always lower than those found using the official spectrophotometric method, thereby underlining the advisability of using HPLC methods to reduce uncertainty in these results.
Detection and quantitation of additions of soybean proteins in cured‐meat products by perfusion reversed‐phase high‐performance liquid chromatography
Authors: Criado Mónica , Castro‐Rubio Florentina , García‐Ruiz Carmen , García María Concepción , Marina María Luisa 
Published: June 2005

AbstractPerfusion liquid chromatography has been applied in this work to the determination of soybean proteins in commercially available cured meat products, enabling the detection of additions of soybean proteins in cured meat products to which the addition of these vegetable proteins is forbidden and the quantitation of soybean proteins in cured meat products to which the addition of these proteins is allowed up to a certain limit. The analytical methodology is based on a sample treatment (fat extraction and soybean protein solubilization) prior to chromatographic analysis. Fat extraction with acetone and soybean protein solubilization with a buffer solution at basic pH (pH 10 or 9) were necessary to obtain selective and sensitive conditions. Use of water‐acetonitrile‐trifluoroacetic acid or water‐tetrahydrofuran‐trifluoroacetic acid linear binary gradients at a flow rate of 3 mL/min, a temperature of 50°C, and UV detection at 280 nm enabled chromatographic analysis of soybean proteins in cured meat products in less than 3 min.
Characterization of Spanish unifloral honeys by solid phase microextraction and gas chromatography‐mass spectrometry
Authors: de la Fuente Esther , Martínez‐Castro Isabel , Sanz Jesús 
Published: June 2005

AbstractVolatile compounds have been investigated in unifloral honeys of the most popular types in Spain. A total of 21 eucalyptus samples, 35 rosemary samples, 33 heather samples, and 15 citrus samples were collected in the course of 3 years in different Spanish regions. Samples were analyzed by SPME followed by GC‐MS. About 83 compounds were identified; the concentrations of 33 of them were selected to be processed by multivariate analysis. Discriminant analysis allowed correct assignment of most samples: 94% citrus, 92% eucalyptus, 84% heather, and 84% rosemary. As pure reference honeys are not available, a two step data analysis is proposed, selecting the samples most clearly classified in discriminant analysis as “reference samples” to be used in multiple regression to estimate the most representative compounds for each honey type and considering the rest of the samples as of mixed origin.
Determination of triacylglycerols in donkey milk by using high performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry
Authors: Dugo Paola , Kumm Tiina , Lo Presti Maria , Chiofalo Biagina , Salimei Elisabetta , Fazio Alessia , Cotroneo Antonella , Mondello Luigi 
Published: June 2005

AbstractThe separation and determination of triacylglycerols (TAGs), which are the main components of naturally occurring fats and oils, in milk fat is a challenging task due to the very complex nature of this matrix. In the present study the TAG fraction of donkey milk lipids has been characterized by using high performance liquid chromatography‐atmospheric pressure chemical ionization mass spectrometry (HPLC‐APCI‐MS). HPLC in reversed phase mode has been used for TAG separation and silver ion (Ag+) HPLC has been used as a second dimension to clarify and confirm the identification. The RP‐HPLC eluate was fractionated and the fractions of interest were injected onto the Ag+‐HPLC column. In both cases peak assignment was carried out by combining retention data with APCI‐MS spectra information. In total, 55 TAGs in donkey milk fat were identified (without considering the positional isomers) and quantified on the basis of percentage peak areas in the RP‐HPLC chromatogram (without the use of correction factors). Amongst the identified triacylglycerols, POLn, POO, PPO, CaPO, POL, and PPoO proved to be the main components of the TAG fraction of donkey milk.
Analytical determination of polyphenols in olive oils
Authors: Carrasco‐Pancorbo Alegria , Cerretani Lorenzo , Bendini Alessandra , Segura‐Carretero Antonio , Gallina‐Toschi Tullia , Fernández‐Gutiérrez Alberto 
Published: June 2005

AbstractThe increasing popularity of olive oil is mainly attributed to its high content of oleic acid, which may affect the plasma lipid/lipoprotein profiles, and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of human disease. An overview of analytical methods for the measurement of polyphenols in olive oil is presented. In principle, the analytical procedure for the determination of individual phenolic compounds in virgin olive oil involves three basic steps: extraction from the oil sample, analytical separation, and quantification. A great number of procedures for the isolation of the polar phenolic fraction of virgin olive oil, utilizing two basic extraction techniques, LLE or SPE, have been included. The reviewed techniques are those based on spectrophotometric methods, as well as analytical separation (gas chromatography (GC), high‐performance liquid chromatography (HPLC), and capillary electrophoresis (CE)). Many reports in the literature determine the total amount of phenolic compounds in olive oils by spectrophometric analysis and characterize their phenolic patterns by capillary gas chromatography (CGC) and, mainly, by reverse phase high‐performance liquid chromatography (RP‐HPLC); however, CE has recently been applied to the analysis of phenolic compound of olive oil and has opened up great expectations, especially because of the higher resolution, reduced sample volume, and analysis duration. CE might represent a good compromise between analysis time and satisfactory characterization for some classes of phenolic compounds of virgin olive oils.
Characterization via liquid chromatography coupled to diode array detector and tandem mass spectrometry of supercritical fluid antioxidant extracts of Spirulina platensis microalga
Authors: Mendiola Jose A. , Marín Francisco R. , Hernández S. Francisco , Arredondo Bertha O. , Señoráns F. Javier , Ibañez Elena , Reglero Guillermo 
Published: June 2005

AbstractSpirulina platensis microalga has been extracted on a pilot scale plant using supercritical fluid extraction (SFE) under various extraction conditions. The extraction yield and the antioxidant activity of the extracts were evaluated in order to select those extracts with both the highest antioxidant capacity and a good extraction yield. These extracts were characterized using LC coupled to diode array detection (DAD) and LC coupled to mass spectrometry (MS) with two different interfaces, atmospheric pressure chemical ionization (APCI) and electrospray (ESI) which allowed us to perform tandem MS by using an ion trap analyzer. The best extraction conditions were as follows: CO2 with 10% of modifier (ethanol) as extraction solvent, 55°C (extraction temperature) and 220 bar (extraction pressure). Fractionation was achieved by cascade depressurization providing two extracts with different activity and chemical composition. Several compounds have been identified in the extracts, corresponding to different carotenoids previously identified in Spirulina platensis microalga along with chlorophyll a and some degradation products. Also, the structure of some phenolic compounds could be tentatively identified. The antioxidant activity of the extracts could be attributed to some of the above mentioned compounds.