bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered resting state networks in mild cognitive impairment and mild Alzheimer's disease: An fMRI study
Authors: Rombouts Serge A.R.B. , Barkhof Frederik , Goekoop Rutger , Stam Cornelis J. , Scheltens Philip
Published: June 2005

Activity and reactivity of the default mode network in the brain was studied using functional magnetic resonance imaging (fMRI) in 28 nondemented individuals with mild cognitive impairment (MCI), 18 patients with mild Alzheimer's disease (AD), and 41 healthy elderly controls (HC). The default mode network was interrogated by means of decreases in brain activity, termed deactivations, during a visual encoding task and during a nonspatial working memory task. Deactivation was found in the default mode network involving the anterior frontal, precuneus, and posterior cingulate cortex. MCI patients showed less deactivation than HC, but more than AD. The most pronounced differences between MCI, HC, and AD occurred in the very early phase of deactivation, reflecting the reactivity and adaptation of the network. The default mode network response in the anterior frontal cortex significantly distinguished MCI from both HC (in the medial frontal) and AD (in the anterior cingulate cortex). The response in the precuneus could only distinguish between patients and HC, not between MCI and AD. These findings may be consistent with the notion that MCI is a transitional state between healthy aging and dementia and with the proposed early changes in MCI in the posterior cingulate cortex and precuneus. These findings suggest that altered activity in the default mode network may act as an early marker for AD pathology. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Characterization of Small Nodules in Cirrhosis by Assessment of Vascularity: The Problem of Hypovascular Hepatocellular Carcinoma *
Authors: Bolondi Luigi , Gaiani Stefano , Celli Natascia , Golfieri Rita , Grigioni Walter Francesco , Leoni Simona , Venturi Anna Maria , Piscaglia Fabio
Published: June 2005

In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver (EASL) recommendations, as a criterion for characterizing small (1-3 cm) nodules in cirrhosis. A total of 72 nodules (1-2 cm, n = 41; 2.1-3 cm, n = 31) detected by ultrasonography in 59 patients with cirrhosis were included in the study. When coincidental arterial hypervascularity was detected at contrast perfusional ultrasonography and helical computed tomography, the lesion was considered to be hepatocellular carcinoma (HCC) according to EASL criteria. When one or both techniques showed negative results, ultrasound-guided biopsy was performed. In cases with negative results for malignancy or high-grade dysplasia, biopsy was repeated when an increase in size was detected at the 3-month follow-up examination. Coincidental hypervascularity was found in 44 of 72 nodules (61%; 44% of 1-2-cm nodules and 84% of 2-3-cm nodules). Fourteen nodules (19.4%) had negative results with both techniques (hypovascular nodules). Biopsy showed HCC in 5 hypovascular nodules and in 11 of 14 nodules with hypervascularity using only one technique. All nodules larger than 2 cm finally resulted to be HCC. Not satisfying the EASL imaging criteria for diagnosis were 38% of HCCs 1 to 2 cm (17% hypovascular) and 16% of those 2 to 3 cm (none hypovascular).
In conclusion
, the noninvasive EASL criteria for diagnosis of HCC are satisfied in only 61% of small nodules in cirrhosis; thus, biopsy frequently is required in this setting. Relying on imaging techniques in nodules of 1 to 2 cm would miss the diagnosis of HCC in up to 38% of cases. Any nodule larger than 2 cm should be regarded as highly suspicious for HCC. (Hepatology 2005.)
Autoimmune Hepatitis: Effect of Symptoms and Cirrhosis on Natural History and Outcome *
Authors: Feld Jordan J. , Dinh Huong , Arenovich Tamara , Marcus Victoria A. , Wanless Ian R. , Heathcote Jenny E.
Published: June 2005

Although the natural history of autoimmune hepatitis (AIH) has been characterized, little is known about patients who present asymptomatically. Consequently, whether they require immunosuppressive therapy with its associated complications is unclear. To compare the natural history of asymptomatic AIH with symptomatic AIH, a large cohort of patients from a single center was examined. All patients with a clinical diagnosis of AIH were reassessed using the revised criteria of the International Autoimmune Hepatitis Group. Liver histology, response to therapy, and survival were assessed. Patients asymptomatic at presentation (n = 31) had lower serum aminotransferase, bilirubin, and immunoglobulin G (IgG) values at baseline. Half of the asymptomatic patients received no therapy, and their survival was no different from that of the total cohort. Ten-year survival was 80.0% (62.5%-97.5%) in the asymptomatic group and 83.8% (75.1%-92.6%) in the symptomatic patients (

P

= NS). Survival to liver-related endpoints at 10 years was similar in both groups: 89.5% (75.7%-100%) asymptomatic and 83.8% (75.1%-92.6%) symptomatic patients (

P

= NS). Patients with cirrhosis at baseline had poorer 10-year survival (61.9% [CI 44.9%-78.9%]) than those without cirrhosis at presentation (94.0% [CI 87.4%-100%]) (

P

= .003) regardless of whether they presented with symptoms or whether they received immunosuppressive therapy.
In conclusion
, patients with AIH who are asymptomatic at presentation have a good prognosis and may not require immunosuppressive therapy. Cirrhosis on initial liver biopsy portends a poor prognosis in all patients with AIH. (Hepatology 2005.)
Properties of acrylic bone cements formulated with Bis‐GMA
Authors: Vallo Claudia I. , Schroeder Walter F.
Published: June 2005

Experimental cement formulations were prepared by replacing part of the methylmethacrylate (MMA) liquid phase of a conventional surgical cement with an equivalent weight of 2,2‐bis [4(2‐hydroxy‐3‐methacryloxypropoxy) phenyl] propane (Bis‐GMA), which is the reaction product of diglycidyl ether of bisphenol A and methacrylic acid. It was found that up to 50 wt % of the MMA could be replaced by Bis‐GMA without reductions in flow characteristics of the precured polymers. Cements containing 20, 30, 40, and 50 wt % of Bis‐GMA in the liquid component were prepared. Over this range of Bis‐GMA wt %, it was found that, relative to the unmodified cement, the volumetric shrinkage (DV), the peak temperature reached during the polymerization reaction (Tp), and the flexural strength (obtained in three‐point bend tests) were each significantly reduced, the flexural modulus (obtained in three‐point bend tests) increased significantly, the compressive strength increased slightly, while there were no significant effects on any of the other properties determined, namely, degree of conversion of the monomer during the polymerization reaction and the glass transition temperature. The drops in DV and Tp indicate that cements whose liquid monomers are modified using Bis‐GMA hold promise for use in anchoring total joint replacements. The increase in the crosslinking density with increasing amount of Bis‐GMA renders the polymer matrix more brittle. This feature was considered responsible for the reduced flexural strength. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Pigmented retinal epithelium involvement in photoreceptor development and function
Authors: Hollyfield Joe G. , Witkovsky Paul
Published: June 2005

The importance of the pigmented retinal epithelium (PRE) for photoreceptor maturation during retinal development was evaluated in Rana pipiens. Retinal rudiments with or without an enveloping PRE were isolated from stage 18 embryos and allowed to develop in a non‐nutrient culture medium for up to 19 days. A set of morphological features with which to evaluate the degree of differentiation occurring in cultured material was obtained through examination of eyes of normal embryos, stages 18–25.

Some photoreceptor outer segment material first appeared after 7 days in culture. The number of well‐ordered outer segment discs per receptor increased progressively with age in PRE‐covered retinas. However, photoreceptors of retinas lacking PRE contained little disc membrane material and this quickly lost proper orientation. Electroretinograms could first be elicited from PRE‐containing cultures after 7 days, but none were produced by retinas lacking a PRE. In PRE‐covered retinas a progressive differentiation of photoreceptor synaptic complexes was seen between 7–19 days; in retinas lacking a PRE, synaptic ribbons appeared after 7 days in culture, but no further maturation of the synapse was observed.

The PRE itself underwent sequential differentiation and achieved the tadpole appearance after 17 days in culture. Both PRE and retina developed at the same rate in cultured material, and this rate was about one‐third that observed in eyes of embryos raised at the same temperature. These findings indicate that the PRE plays a critical role in photoreceptor development.
Temperature modulation of the kinetics of phosphoglucose isomerase genetic variants from the sea anemone Metridium senile
Authors: Hoffmann Richard J.
Published: June 2005

The 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

Female 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

The 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

Although 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

Grafts 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

The 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

Radiolabelled [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

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

Sumitriptan (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

Microglia, 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

Differential 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

Methods 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

A 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

Perfusion 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

Volatile 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

The 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

The 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

Spirulina 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.
Optimizing the separation of food dyes by capillary electrophoresis
Authors: Jager Alessandra Vincenzi , Tonin Fernando Gustavo , Tavares Marina Franco Maggi
Published: June 2005

In this work, the separation of eleven food dyes was evaluated by MEKC in electrolytes composed of tetraborate (TBS), Brij 35, and acetonitrile (ACN) using a factorial design at the following levels: TBS concentration (5 and 10 mmol L–1), pH (9.5 and 10.1), Brij concentration (5 and 20 mmol L–1), and ACN (5 and 15%). Several response functions were evaluated and indicated 10 mmol L–1 TBS (pH 10.1), 15% ACN, and 20 mmol L–1 Brij 35 as best values. However, baseline resolution was not achieved (Rcp = 0.76) and the method lacked robustness. New conditions were sought by studying the dye mobility versus Brij concentration (5–20 mmol L–1). A set of well resolved and more uniformly spaced peaks was obtained with an electrolyte consisting of 7.5 mmol L–1 TBS (pH 10.1), 10 mmol L–1 Brij, and 15% ACN. Under these new conditions, complete resolution of the 11 dyes was achieved in less than 9 min. Migration time and peak area repeatabilities were better than 1.6% and 5% CV and the LODs were 0.47 to 2.3 μg mL–1. The methodology was applied to fruit juice powders, lollipops, and other hard and soft chewable treats.
Oxidative stability and phenolic content of virgin olive oil: An analytical approach by traditional and high resolution techniques
Authors: Gallina‐Toschi Tullia , Cerretani Lorenzo , Bendini Alessandra , Bonoli‐Carbognin Matteo , Lercker Giovanni
Published: June 2005

The characteristic resistance to oxidation of virgin olive oil is related to its unique fatty acid composition in addition to several minor components that have antioxidant properties. Among the latter, phenols are the most important. Several factors can influence the chemical or enzymatic oxidative processes that extend or shorten the shelf‐life of olive oil. Furthermore, the amount of phenolic compounds extracted during production is fundamental for the oxidative and nutritional quality of the oil. In fact, it is well known that different steps used for preparation of virgin olive oil may determine differences in the quantities of phenol. At present, various analytical methods are available to analyze the hydrophilic components, including spectrophotometric assays (traditional) and high resolution chromatographic techniques (HRGC, HPLC, HPCE). In this review we summarize these different methodologies and demonstrate that the amount of phenolic compounds in virgin olive oil as determined by both traditional and high resolution techniques can be influenced by different factors including the olive cultivar and degree of ripeness, as well as by production and extraction technologies.
Capillary electrophoresis in food authenticity
Authors: Kvasnička František
Published: June 2005

Food authenticity is a term which simply refers to whether the food purchased by the consumer matches its description. False description can occur in many forms, from the undeclared addition of water or other cheaper materials, or the wrong declaration of the amount of a particular ingredient in the product, to making false statements about the source of ingredients i.e., their geographic, plant, or animal origin. The aim of this review is to summarize applications of capillary electrophoresis in food authentication.
Determination of organic acids in wine by zone electrophoresis on a chip with conductivity detection
Authors: Masár Marián , Poliaková Katarína , Danková Mariana , Kaniansky Dušan , Stanislawski Bernd
Published: June 2005

An appropriate combination of separation mechanisms (simultaneous use of differences in pK values, host‐guest complexations, and the ionic strength dependences of the actual ionic mobilities) provided zone electrophoresis (ZE) resolution of 22 organic and inorganic acids expected in wines on a polymethylmethacrylate (PMMA) chip with integrated conductivity detection. These separating conditions offered a framework for the ZE determination of organic acids responsible for some important organoleptic characteristics of wines (tartrate, malate, succinate, acetate, citrate, and lactate). The ZE procedure developed in this context is simple and rapid (ca. 10 minutes’ analysis time), while affording reproducible migration and quantitation data for the acids. For example, 0.8–2.0% RSD values characterized the migration times of the acids for 25 repeated ZE runs with the same sample carried out in 5 days in the background electrolyte solution prepared freshly on a daily basis, while 3–5% RSD values were typical for the accompanying peak area data. The concentration ranges within which the acids of analytical interest could be determined in one ZE run covered all wine samples included in our study (100–400‐fold sample dilutions were needed to work under the conditions corresponding to the validities of the calibration data). 90–110% recoveries of the acids as obtained repeatedly for one of the reference wine samples used in our experiments indicate a good predisposition of the present method to provide accurate analytical results. This statement also supports the results from the determination of the acids in reference wine samples with claimed concentrations of malic (five samples), tartaric (one sample), and lactic (one sample) acids.
Analysis of methoxypyrazines in wine using headspace solid phase microextraction with isotope dilution and comprehensive two‐dimensional gas chromatography
Authors: Ryan Danielle , Watkins Peter , Smith Jason , Allen Malcolm , Marriott Philip
Published: June 2005

This study reports an optimized headspace‐solid phase microextraction (HS‐SPME) method for the determination of methoxypyrazines in wine. Analysis was performed by using comprehensive two‐dimensional gas chromatography with novel detection capabilities, including nitrogen phosphorus detection (GC×GC‐NPD) and time‐of‐flight mass spectrometry (GC×GC‐TOFMS). In the latter, stable isotope dilution was performed for the quantitation of 2‐methoxy‐3‐(2‐methylpropyl) pyrazine (IBMP), using labelled 2‐(2H3)methoxy‐3‐(2‐methylpropyl)pyrazine (d3‐IBMP) as the internal standard, and resolution of the two analogues was facilitated using the deconvolution capabilities of the TOFMS. This research represents the first report of HS‐SPME with isotope dilution and GC×GC‐TOFMS (GC×GC‐IDTOFMS). Analysis by GC×GC‐NPD enabled detection limits of 0.5 ng/L for the quantitation of IBMP, which was superior to that obtained using GC×GC‐IDTOFMS (1.95 ng/L). Nevertheless, both methods were adequately sensitive for real wine analysis, yielding highly comparable IBMP concentrations of 26.1 and 27.8 ng/L, respectively, from a Sauvignon blanc wine. The complexity of the real wine headspace was simplified as a result of selective detection using GC×GC‐NPD and, in the case of GC×GC‐IDTOFMS, the use of extracted ion chromatograms (EICs).
Rapid Dissolution of Cellulose in LiOH/Urea and NaOH/Urea Aqueous Solutions
Authors: Cai Jie , Zhang Lina
Published: June 2005

Summary: Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions was studied systematically. The dissolution behavior and solubility of cellulose were evaluated by using 13C NMR, optical microscopy, wide‐angle X‐ray diffraction (WAXD), FT‐IR spectroscopy, DSC, and viscometry. The experiment results revealed that cellulose having viscosity‐average molecular weight ($\overline M _\eta $) of 11.4 × 104 and 37.2 × 104 could be dissolved, respectively, in 7% NaOH/12% urea and 4.2% LiOH/12% urea aqueous solutions pre‐cooled to −10 °C within 2 min, whereas all of them could not be dissolved in KOH/urea aqueous solution. The dissolution power of the solvent systems was in the order of LiOH/urea > NaOH/urea ≫ KOH/urea aqueous solution. The results from DSC and 13C NMR indicated that LiOH/urea and NaOH/urea aqueous solutions as non‐derivatizing solvents broke the intra‐ and inter‐molecular hydrogen bonding of cellulose and prevented the approach toward each other of the cellulose molecules, leading to the good dispersion of cellulose to form an actual solution.

13C NMR chemical shifts of carbonyl carbon for urea in LiOH (a) and NaOH (b) of the cellulose solutions.

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13C NMR chemical shifts of carbonyl carbon for urea in LiOH (a) and NaOH (b) of the cellulose solutions.
Cover Picture: Macromol. Chem. Phys. 12/2005
Authors: Yagci Yusuf , Yilmaz Faruk , Kiralp Senem , Toppare Levent
Published: June 2005

Cover: The picture on the cover illustrates the photochemical polymerization of thiophene using onium salts. The photographs show the polymerization mixture of thiophene and iodonium salt in CH2Cl2 before (a), after 5 min of irradiation (b), and the dried film (c). Further details can be found in the Full Paper by Y. Yagci,* F. Yilmaz, S. Kiralp, and L. Toppare on page 1178.
A Simulation and Experimental Study of the Hydrodynamics of a Bubbling Fluidized Bed of Linear Low Density Polyethylene Using Bubble Properties and Pressure Fluctuations
Authors: Chandrasekaran Blake K. , van der Lee Loni , Hulme Ian , Kantzas Apostolos
Published: June 2005

Summary: The purpose of this work is to use power spectral analysis of pressure fluctuations in conjunction with bubble properties obtained from an advanced experimental technique to validate the Computational Fluid Dynamics (CFD) simulations of an air/polyethylene fluidized bed. The current Eulerian models based on the kinetic theory of granular flow have been studied extensively for systems that have ideal characteristics for the solid phase. However, the models need to be investigated for particles such as polyethylene that do not have ideal characteristics with respect to shape, size distribution and elastic character from a simulation standpoint. Unlike previous works, which mostly use average bubble properties for validation, this work utilizes both pressure fluctuations and bubble properties of a high temporal and spatial resolution for the validation process. Results have indicated that significant work is required to adapt the solid phase model in the MFIX (Multiphase Flow with Interphase eXchange) CFD code for particles such as polyethylene.

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Clinical characteristics in early Parkinson's disease in a central California population‐based study
Authors: Kang Gail A. , Bronstein Jeff M. , Masterman Donna L. , Redelings Matthew , Crum Jarrod A. , Ritz Beate
Published: June 2005

There is considerable variation in the phenotypic appearance of individuals with idiopathic Parkinson's disease (PD), which may translate into differences in disease progression in addition to underlying disease etiology. In this publication, we report on the demographic and clinical characteristics of 162 individuals diagnosed with clinically probable PD from January 1998 to June 2003 who resided in predominantly rural communities in central California. The majority of the subjects were Caucasian, male, and between 60 and 79 years of age. The akinetic–rigid and tremor‐dominant subtypes were more common than the mixed subtype. The majority of subjects displayed motor signs of rigidity (92.0%), bradykinesia (95.7%), and gait problems (87.0%), whereas less than half (43.3%) of the subjects displayed a tremor. Three fourths of patients received a Hoehn and Yahr Scale score of Stage 2 or higher. One third of the patients were treated with levodopa, and patients under 60 years of age were more likely to be treated with dopamine agonists. Within 3 years after first diagnosis, 13% of subjects showed some signs of depression and 17% of subjects met criteria for mild dementia. Among our subjects, 17.3% reported a family history of PD in first‐ or second‐degree relatives,15.4% a family history of essential tremor, and 14.2% of Alzheimer's disease. This study represents the most extensive phenotypic description of rural U.S. residents in the initial stages of PD who were recruited in a population‐based manner; future follow‐up may provide valuable information regarding the prognostic indication of these symptoms/signs and improve our understanding of the underlying etiology of PD. © 2005 Movement Disorder Society
Task‐dependent modulation of silent period duration in focal hand dystonia
Authors: Stinear Cathy M. , Byblow Winston D.
Published: June 2005

Focal hand dystonia (FHD) is a movement disorder that is also associated with impaired sensory function and sensorimotor integration. The aim of this study was to assess the modulation of inhibitory function in the motor cortex during the performance of four motor tasks (isometric pinch grip, writing, texture discrimination, and a phasic control task) in 8 FHD and 8 control subjects. The affected hands of the FHD subjects and the dominant hands of the control subjects were tested. Inhibitory function was assessed using transcranial magnetic stimulation to evoke a silent period in the ongoing electromyographic activity of the target muscle (first dorsal interosseous). There was no difference between FHD subjects and control subjects in silent period duration, which was significantly longer during the phasic texture discrimination and phasic control task than during the isometric pinch or writing. This finding suggests that the phasic nature of the task may increase cortical inhibitory function, rather than the sensory discrimination task itself. The accuracy of texture discrimination was significantly lower in FHD subjects than in control subjects. Sensory discrimination tasks do not appear to directly modulate the inhibitory processes responsible for the duration of the silent period. © 2005 Movement Disorder Society
Antidepressant studies in Parkinson's disease: A review and meta‐analysis
Authors: Weintraub Daniel , Morales Knashawn H. , Moberg Paul J. , Bilker Warren B. , Balderston Catherine , Duda John E. , Katz Ira R. , Stern Matthew B.
Published: June 2005

The objective of this study was to determine effect sizes for both antidepressant treatment and placebo for depression in Parkinson's disease (PD), and to compare the findings with those reported in elderly depressed patients without PD. Recent reviews have concluded that there is little empiric evidence to support the use of antidepressants in PD; however, available data has not been analyzed to determine the effect size for antidepressant treatment in PD depression. A literature review identified antidepressant studies in PD. Suitable studies were analyzed using meta‐analytic techniques, and effect sizes were compared with those from antidepressant studies in elderly patients without PD. Large effect sizes were found for both active treatment and placebo in PD, but there was no difference between the two groups. In contrast, active treatment was superior to placebo in depressed elderly patients without PD. In PD, increasing age and a diagnosis of major depression were associated with better treatment response. Results also suggest that newer antidepressants are well tolerated in PD. Despite the high prevalence of depression and antidepressant use in PD, controlled treatment research has been almost nonexistent. Meta‐analysis results suggest a large but nonspecific effect for depression treatment in PD. In addition, PD patients may benefit less from antidepressant treatment, particularly selective serotonin reuptake inhibitors, than do elderly patients without PD. © 2005 Movement Disorder Society