bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional MRI mapping of stimulus rate effects across visual processing stages
Authors: Schneider Walter , Casey B. J. , Noll Douglas 
Published: December 2004

AbstractFunctional magnetic resonance imaging (fMRI) was used to record cortical activation across multiple stages in the visual system during single character visual search and reversing checkerboard stimulation. Scanning used T2‐weighted, gradient echo sequences with late echo times (TE = 36 ms) with a voxel size of 0.94 * 1.88 mm in‐plane resolution, 4–5 mm deep, on a conventional scanner. A scout experiment recorded six slices to identify major regions of activation. Two slices were selected for extensive assessment. Character stimuli activated small (average 16 mm2), reliable, statistically defined regions of activation in the calcarine fissure, superior occipital cortex, and fusiform‐lingual gyrus. The results include: (1) for character search, the MRI signal change increased linearly from 2.1 to 3.1% for stimulation from 1 to 8 Hz; (2) the character rate effect was equivalent across three levels of the visual system; (3) the checkerboard stimuli showed broader, more intense primary visual activation and less intense secondary visual activation than did character search. Issues relating to fMRI signal variability across the imagining plane, statistical data analysis, signal sensitivity, statistical power, fMRI experimental protocols, and comparisons with positron emission tomography (PET) data are discussed. © 1994 Wiley‐Liss, Inc.
Regional brain activity when selecting a response despite interference: An H215O PET study of the stroop and an emotional stroop
Authors: George M. S. , Ketter T. A. , Parekh P. I. , Rosinsky N. , Ring H. , Casey B. J. , Trimble M. R. , Horwitz B. , Herscovitch P. , Post R. M. 
Published: December 2004

AbstractThe Stroop interference test requires a person to respond to specific elements of a stimulus while suppressing a competing response. Previous positron emission tomography (PET) work has shown increased activity in the right anterior cingulate gyrus during the Stroop test. It is unclear, however, whether the anterior cingulate participates more in the attentional rather than the response selection aspects of the task or whether different interference stimuli might activate different brain regions. We sought to determine (1) whether the Stroop interference task causes increased activation in the right anterior cingulate as previously reported, (2) whether this activation varied as a function of response time, (3) what brain regions were functionally linked to the cingulate during performance of the Stroop, and (4) whether a modified Stroop task involving emotionally distracting words would activate the cingulate and other limbic and paralimbic regions. Twenty‐one healthy volunteers were scanned with H215O PET while they performed the Stroop interference test (standard Stroop), a modified Stroop task using distracting words with sad emotional content (sad Stroop), and a control task of naming colors. These were presented in a manner designed to maximize the response selection aspects of the task. Images were stereotactically normalized and analyzed using statistical parametric mapping (SPM). Predictably, subjects were significantly slower during the standard Stroop than the sad Stroop or the control task. The left mideingulate region robustly activated during the standard Stroop compared to the control task. The sad Stroop activated this same region, but to a less significant degree. Correlational regional network analysis revealed an inverse relationship between activation in the left mideingulate and the left insula and temporal lobe. Additionally, activity in different regions of the cingulate gyrus correlated with performance speed during the standard Stroop. These results suggest that the left midcingulate is likely to be part of a neural network activated when one attempts to override a competing verbal response. Finally, the left midcingulate region appears to be functionally coupled to the left insula, temporal, and frontal cortex during cognitive interference tasks involving language. These results underscore the important role of the cingulate gyrus in selecting appropriate and suppressing inappropriate verbal responses. © 1994 Wiley‐Liss, Inc.
Functional imaging of procedural motor learning: Relating cerebral blood flow with individual subject performance
Authors: Grafton Scot. T. , Woods Roger P. , Tyszka Mike 
Published: December 2004

AbstractChanges of local synaptic activity during acquisition of a visuomotor skill were examined with positron emission tomography (PET) imaging of regional cerebral blood flow (rCBF). Eight subject learned the pursuit rotor task, a predictable tracking task, during three sequential PET scans (day 1). Subjects returned 2 days later and repeated the three pursuit trials and PET scans (day 2) after completing an extensive practice session. Control scans without movement bracketed the pursuit trials on both days to rule out time effects unrelated to motor skill learning. PET images were transformed to a common stereotaxic space using matched magnetic resonance imaging (MRI) scans. Group learning effects were determined by a repeated measures multivariate analysis of variance (ANOVA). During motor skill acquisition (day 1), increases of synaptic activity were identified in cortical motor areas and cerebellum, supporting the hypothesis that procedural motor learning occurs in motor execution areas. During long‐term practice (day 2), changes were limited to the bilateral putamen, bilateral parietal cortex, and left premotor cortex. To characterize differences in the rate of learning between subjects, each subject's performance data from day 1 was fit with a power function. The exponents were correlated with rCBF data on a pixel‐by‐pixel basis. Rapid skill acquisition was associated with increasing rCBF in premotor, prefrontal, and cingulate areas, and decreasing rCBF in visual processing areas located in the temporal and occipital cortex. This pattern in fast learners may reflect a more rapid shift from a visually guided strategy (accessing perceptual areas) to an internally generated model (accessing premotor and prefrontal areas). © 1994 Wiley‐Liss, Inc.
‘Threats’ to and hopes for estimating benefits
Authors: Ryan Mandy , Amaya‐Amaya Mabelle 
Published: December 2004

AbstractIn a recent paper in this journal, Andrew Lloyd reviewed some potential threats to the estimation of health care benefits in monetary terms. Particular emphasis was placed on the extent to which the use of non‐compensatory heuristics may distort the results. Although it is useful to be reminded of these problems, Lloyd's paper does not do justice to the attention such issues have already received, and continue to receive, within Health Economics. The aim of this paper is twofold. Firstly, it seeks to provide a more balanced and comprehensive view of the evidence by considering some of the methodological work that health economists have conducted in many of the areas pointed out by Lloyd. Secondly, and more importantly, it suggests ways to combine the economic and psychological views of human decision‐making, providing a much more positive perspective to all those researchers out there who recognize the necessity of using stated preference methods to inform health policy. Copyright © 2004 John Wiley & Sons, Ltd.
Über die Acetylierung von primären aromatischen Aminen in vivo und in vitro. Versuche mit p‐Aminobenzoesäure, 2‐Sulfanilamido‐thiazol, Anilinhydrochlorid und Sulfanilsäure
Authors: Zehender F. 
Published: December 2004

AbstractVon einer Reihe primärer aromatischer Amine wurde der Acetylierungsgrad einerseits beim Menschen und beim Meerschweinchen, andererseits in vitro unter Verwendung von Essigsäure‐anhydrid bestimmt. Für drei von den vier untersuchten Verbindungen, für p‐Aminobenzoesäure, Sulfathiazol und Sulfanilsäure gilt folgende Gesetzmässigkeit: Einer Substanz mit grösserer Basizitätskonstante entspricht eine stärkere Acetylierung in vivo und in vitro. Anilin macht im Tierversuch eine Ausnahme, indem es relativ wenig acetyliert wird.
Synthese von optisch aktiven, natürlichen Carotinoiden und strukturell verwandten Verbindungen. III. Synthese von (+)‐Abscisinsäure, (−)‐Xanthoxin, (−)‐Loliolid, (−)‐Actinidiolid und (−)‐Dihydroactinidiolid
Authors: Kienzle Frnak , Mayer Hans , Minder Rudolf E. , Thommen Hans 
Published: December 2004

Synthesis of optically active natural carotenoids and structurally related compounds. III. Synthesis of (+)‐abscisic acid, (−)‐xanthoxin, (−)‐loliolide, (−)‐actinidiolide, and (−)‐dihydroactinidiolideThe syntheses of (+)‐abscisic acid (1), (−)‐xanthoxin (2), (−)‐loliolide (3), (−)‐actinidiolide (4), and of (−)‐dihydroactinidiolide (5) from one common starting material are reported. The syntheses yield also some enantiomeric or diastereomeric analogues.
Photochemische Reaktionen. 97 Mitteilung [1]. Zur Photochemie konjugierter Epoxy‐diene II. Versuche mit (E)‐β‐Jonyliden‐epoxiden
Authors: Alder Alex Peter , Wolf Hans Richard , Jeger Oskar 
Published: December 2004

Photolysis of Conjugated Epoxy‐dienesDirect and sensitized excitation of the (E)‐β‐ionylidene‐epoxides 1 and 4 leads to different types of isomerizations. Thus photocycloelimination to the cyclopropene‐ketones 2 and 6 is only achieved by 1(π, π*)‐excitation (λ=254 nm), whereas 3(π, π*)‐excitation (λ > 280 nm, acetone) gives selective C(1′), O‐cleavage of the oxirane (1→7 – 10 and 4→11 – 13). In contrast to 1 the twofold methylsubstituted epoxy‐diene 4 shows mainly (E/Z)‐isomerization (4 → 5) on both 1(π, π*)‐ and 3(π, π*)‐excitation while the isomerizations 4→6 and 4→11 – 13 are minor processes, only.
Hydrogen Evolution from Water by Visible Light, a Homogeneous Three Component Test System for Redox Catalysis
Authors: Kalyanasundaram Kuppuswamy , Kiwi John , Grätzel Michael 
Published: December 2004

AbstractIrradiation by visible light of a neutral aqueous solution containing Ru (bipy) as a sensitizer, methylviologen (MV+2) as an electron acceptor and triethanolamine or cysteine as an electron donor leads to the formation of stable methylviologen radical cation (MV+). The kinetics and mechanism of the photoinduced reactions occurring in such a system were explored by laser photolysis technique. In the presence of Adams catalyst MV+ is reoxidized by water under simultaneous evolution of hydrogen. Optimum conditions for the water reduction under continuous illumination are elaborated and implications for an energy conversion system discussed.
Synthese von optisch aktiven, natürlichen Carotinoiden und strukturell verwandten Naturprodukten. VIII. Synthese von (3S,3′S)‐7,8,7′,8′‐Tetradehydroastaxanthin und (3S,3′S)‐7,8‐Didehydroastaxanthin (Asterinsäure)
Authors: Bernhard Kurt , Kienzle Frank , Mayer Hans , Müller Robert K. 
Published: December 2004

Synthesis of Optically Active Natural Carotenoids and Structurally Related Compounds. VIII. Synthesis of (3S,3′S)‐7,8,7′,8′‐Tetradehydroastaxanthin and (3S,3′S)‐7,8‐Didehydroastaxanthin (Asterinic Acid)The synthesis of all‐trans‐(3S,3′S)‐3,3′‐dihydroxy‐7,8, 7′,8′‐tetradehydro‐β, β‐carotene‐4,4′‐dione (1), of all‐trans‐(3S,3′S)‐3,3′‐dihydroxy‐7, 8‐didehydro‐β,β‐carotene‐4,4′‐dione (2) (asterinic acid = mixture of 1 and 2), and of their 9,9′‐di‐cis‐ and 9‐cis‐isomers is reported starting from (4′S)(2E)‐5‐(4′‐hydroxy‐2′, 6′,6′‐trimethyl‐3′‐oxo‐l′‐cyclohexenyl)‐3‐methyl‐2‐penten‐4‐ynal (8). The absolute configuration (3S,3′S) for both components 1 and 2 of asterinic acid ex Asterias rubens is confirmed on the basis of spectroscopic and direct comparison.
Cob(I)alamin als Katalysator. Retention der Konfiguration bei der reduktiv‐protonenübertragenden Spaltung der Co, C‐Bindung eines Alkylcobalamins. 7. Mitteilung [1]
Authors: Fischli Albert , Müller Peter Michael 
Published: December 2004

Cob(I)alamin as Catalyst. 7. Communication [1]. Retention of Configuration during the Reductive Cleavage of the Co, C‐Bond of an AlkylcobalaminUsing catalytic amounts of cob(I)alamin (see Scheme 1) in aqueous acetic acid (−)‐α‐pinen (1) and (−)‐β‐pinen (2; s. Scheme 3) have been reduced. A large excess of metallic zinc served as electron source. The saturated products 5–8 (see Scheme 3) and the mechanistic aspects of their generation are discussed. The relative amounts of cis‐ (5) and trans‐pinane (6) lead to the conclusion that the reductive cleavage of the Co, C‐bond accompanied by H+ transfer in an alkylcobalamin occurs with retention of configuration. This result is in agreement with the corresponding cleavage of the Co,C‐bond of an alkyl[hydroxy‐diazaoctahydroporphinato]cobalt complex [9].
Stereoselective total syntheses of (±)‐chanoclavine I and (±)‐isochanoclavine I by an intramolecular nitrone‐olefin/cycloaddition. Preliminary communication
Authors: Oppolzer Wolfgang , Grayson J. Ian 
Published: December 2004

AbstractThe racemic alkaloids chanoclavine I (1) and isochanoclavine I (2) have been synthesized stereoselectively from indole‐4‐carbaldehyde (3) by a sequence of 11 operations in overall yields of 14% and 2.4%, respectively. The key step 6 → 8 (Scheme 2) involves a transient nitrone 7 which undergoes a regio‐ and stereoselective intramolecular cycloaddition to a 1,2‐disubstituted olefinic bond.
A case of triazolam abuse
Authors: Kuniyoshi M. , Arikawa K. , Miura C. , Nakamura J. , Inanaga K. 
Published: December 2004

AbstractA case of abuse of triazolam, a short‐acting benzodiazepine, was experienced. A 35‐year‐old male, with a tendency to mixed drug dependence with nitrazepam, etc., and a background of neurotic anxiety and insomnia, started self‐administration of triazolam. Application of triazolam was frequent, with large doses up to a maximum of 80 mg/day (320 times the recommended daily dose of 250 micrograms). In addition to psychic dependence, occurrence of withdrawal symptoms confirmed formation of physical dependence, which was also supported by EEG together with the appearance of various autonomic and psychic symptoms.Even though triazolam is known to be comparatively safe, this case confirms that it can induce physical dependence upon frequent administration of a large amount, together with psychic dependence, and therefore care must be taken with regard to dosage. In particular, self‐administration of the drug should be strictly controlled.
Recent advances in the clinical pharmacology of benzodiazepines part II: Pharmacodynamics
Authors: Saletu B. , Pakesch G. 
Published: December 2004

AbstractTranquilizers, and specifically benzodiazepines (BZD), have become one of the most widely used group of drugs in the world; some have suggested too widely used. Interest in these drugs in still extremely high, both from the scientific and sociological point of view. This is best documented by the fact that the present review is based on more than 700 articles published between 1981 and 1984 covering various aspects of clinical pharmacology. Pharmacodynamic studies are mostly concerned with effects of the drug on the central nervous system (CNS), as well as on behavious and neuroendocrine functions. The former include computer‐assisted quantitative analyses of the scalp‐recorded wake electroencephalogram (EEG), based on which it seems possible to determine if, how, when and at what dose a newly developed compound affects the human brain. Sleep investigations are now concerned not only with the effect of the drug on the all‐night sleep, but also on the quality of awakening and early morning behaviour as well as with residual effects during daytime, affecting amnestic and cognitive functions, psychomotor performance (specifically in regard to driving ability), as well as mood and affectivity. Finally, for almost a decade increasing concern has been expressed about the widespread use of tranquillizers in society. Scientific evidence concerning thiss issue will be reviewed so that an appropriate medical decision may be reached for the treatment of the individual patients after consideration of the beneficial effects as well as undesirable side‐effects.
Urinary cyclic AMP response to bovine parathyroid hormone during treatment with neuroleptics
Authors: Waller Derek G. , Albano Janet D. M. , Guyedwards J. 
Published: December 2004

AbstractThe urinary cyclic AMP response to bovine parathyroid hormone and urinary concentrating ability (max Uosm) after des‐amino‐D‐arginine vasopressin were studies in nine volunteers and seven patients receiving long‐term neuroleptic treatment. Max Uosm was lower in the patient group (770 ± 70 mosmol/kg) compared with the controls (948 ± 152 mosmol/kg) but the trend to a lower cAMP response to bovine PTH was not statistically significant. These results suggest that, although adenylate cyclase inhibition may contribute, other mechanisms are also important in the genesis of reduced uring concentrating ability in patients treated with psychotropic drugs.
Response to clomipramine after short course of lithium in treatment‐resistant depression: Does lithium have a ‘priming’ effect?
Authors: Chiu Leo P. W. , Rimon Ranan 
Published: December 2004

AbstractA patient with a treatment‐resistant depression of 15 months duration is reported. Initially he showed no response to clomipramine 150 mg daily for 1 month. When lithium carbonate 600 mg daily was added for 4 days he developed signs of lithium intoxication: drowsiness, confusion, and dystonia. After lithium was withdrawn the patient improved dramatically. We hypothesize that lithium may potentiate the antidepressant effect of tricyclic antidepressants (TCA) even if it is administered as a short course of treatment.
The renal excretion of xanthurenic acid following L‐tryptophan loading in depressed patients
Authors: Maes M. , De Ruyter M. , Suy E. 
Published: December 2004

AbstractXanthurenic acid (XA) is a secondary product of the biosynthesis of nicotinamide from L‐tryptophan. Disturbances in this pathway have been observed in depression. An enhanced glucocorticoid secretion is considered to induce this pathway. This could result in reduced levels of L‐tryptophan (L‐TRP) in the plasma. The present study investigates whether the synthesis of XA from L‐TRP is distrubed in depression, and also whether the synthesis of XA is intercorrelated with L‐TRP or measures of glucocorticoid secretion. To this end the XA excretion in 24 hour urine following L‐TRP loading was determined in 166 psychiatric inpatients. There were no significant differences in XA excretion between non‐depressed psychiatric controls, minor depression and major depression. Among the depressed patients there was a significant (p<0·01) negative correlation between the excretion of XA and total L‐TRP levels in plasma, with abnormally decreased (p<0·0006) L‐TRP levels occurring in the depressed patients with a disturbed XA excretion (≥ 106·8 m̈mol/24 hour).
Neutrophil mobilization in lithium‐induced neutrophilia
Authors: Roath Stuart , Choudhury Dina , Edwards J. Guy , Francis John L. , Gordon Alan 
Published: December 2004

AbstractTwenty patients on long‐term treatment with lithium who had persistently elevated neutrophil counts were challenged with adrenalin and hydrocortisone to measure their marginal and bone marrow granulocyte pools. Compared with normal controls the results suggest that the absolute numbers of granulocytes in each pool are not increased, although the percentage change is diminished because of the greater baseline values in the experimental group. These data suggest that lithium acts on granulopoiesis within the bone marrow, and are in keeping with the concept that the granulocyte reserve has a finite size. There is no apparent connection between lithium‐induced neutrophilia and either the therapeutic or unwanted effects of lithium.
Intra‐Accumbens trh prolongs maintenance of tolerance to hypothermic effect of ethanol in rats
Authors: Pucilowski O. , Trzaskowska E. , Kostowski W. 
Published: December 2004

AbstractTolerance to the hypothermic effect of ethanol (Et–OH) developed in male Wistar rats treated daily with 5 g/kg of 20 per cent ET–OH v/v i.g. for 6 days. On Day 6 Et–OH treatment was discontinued and the animals were divided into two groups injected into the nucleus accumbens septi (NAS), either with pGlu‐His‐Pro‐NH2 (TRH) or saline. The peptide was injected via permanently implanted cannulae in doses of 10 or 30 m̈g in 0.5 m̈l on each side once daily. The effect of such treatment on the maintenance of Et–OH tolerance was assessed by measuring the temperature decrement in response to a challenge dose of Et–OH (5 g/kg i.p.) given on Day 10. It was found that in saline‐treated rats the initial tolerance declined. TRH‐injected groups exhibited constantly low response to hypothermic action of Et–OH. In a control experiment TRH was shown to have no effect on the body temperature after intra‐accumbens application in Et–OH‐naive rats.
Erythrocyte lithium–sodium countertransport and total body lithium pharmacokinetics in patients with affective illness
Authors: Rybakowski Janusz , Lehmann Wenancja , Kanarkowski Roman 
Published: December 2004

AbstractPrevious studies suggested that in patients with affective illness, lithium ion accumulated more in erythrocytes (higher erythrocyte lithium ratio) as well as in the total body (greater lithium retention). The aim of this study was to estimate the relationship between erythrocyte lithium transport mechanisms and the parameters of lithium pharmacokinetics in 11 affective patients during depressive episodes. It was found that the activity of erythrocyte lithium–sodium countertransport (LSC) governing lithium transport out of the erythrocytes, measured in vitro significantly correlated with rate constant (K21) of lithium trnsport from intra‐ to extracellular compartment. Passive lithium diffusion (PLD) in erythrocytes correlated with K21/K12 ratio. Neither LSC nor PLD correlated with renal lithium clearance. The results show that, in affective patients, the activity of erythrocyte LSC may serve as a model of the intensity of lithium extrusion from cells in the total body.
The psychopharmacological effects of single doses of prolonged release formulations of dimethindene and chlorpheniramine in human volunteers
Authors: Lee Anthony , Lader Malcolm , Kitler Mary Ellen 
Published: December 2004

Abstract1. The effects of single doses of dimethindene (retard) 2·5 mg, chlorpheniramine (TD) 12mg and placebo on a battery of physiological, performance and subjective measures were studied in a double‐blind, crossover study in 12 healthy subjects.2. Dimethindene had a different EEG profile from chlorpheniramine; while both active drug treatments were associated with an increase in 8·0–13·0 Hz waveband activity, dimethindene alone produced less 2·0–4·0 Hz activity.3. The two active drugs were associated with an improvement in tapping rate. Dimethindene had no effect on simple reaction time, while chlorpheniramine was associated with a slowing in this measure.4. Subjective measures generally indicated an improvement in general alertness and contentedness with both dimethindene and chlorpheniramine.5. It is concluded that single doses of sustained‐release formulations of these antihistamines are slightly stimulant in effect and are useful where sedation in unacceptable.