bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproducibility of the determination of caffeine in coffee by micellar electrokinetic capillary chromatography
Authors: Burton D. Edward , Powell Larry L. , Xi Xiaobing
Published: May 2005

Samples of regular and decaffeinated varieties of green coffee beans, instant coffee, and “roast & grind” coffee have been examined by micellar electrokinetic capillary chromatography (MECC). The separation conditions affecting the reproducibility of the determination of caffeine in these samples are presented. Sodium dodecyl sulfate (SDS) and cetyltrimethylammonium chloride (CTAC) Were employed to demonstrate the role of the surfactant system in reproducibility. The use of NaOH and HCl was explored for column rinsing to enhance the stability of the electroosmotic flow. The levels of caffeine ranged from 3.95% (by weight) for regular coffee to 0.07% for decaffeinated coffee. The relative standard deviation (RSD) for the migration time of the peak corresponding to caffeine in coffee samples was 0.74%. The RSDs for the peak areas and heights were 1.04 and 2.07%, respectively. The results of the quantitation of caffeine by MECC are compared to levels determined by high‐performance liquid chromatography (HPLC).
Supercritical fluid extraction and capillary gas chromatography of the rhizomes of Z. zerumbet
Authors: Ahmad Umi K. , Sirat Hasnah M. , Sanagi M. Marsin , Smith Roger M.
Published: May 2005

Supercritical carbon dioxide at 60°C and 200 bar has been used to extract the nonpolar components of the dried rhizomes of Zingiber zerumbet. The extract could be fractionated by placing an on‐line silica column before the pressure relief valve. The extracts were analyzed using capillary GC and GC‐MS. This technique provides an effective means of sample preparation and a relatively fast way of determining the constituents of plant materials.
On‐column ITP focusing in CZE for the quantitation of low‐molecular‐weight basic solutes in biological samples
Authors: Larsson Marita , Någård Sofia
Published: May 2005

Capillary zone electrophoretic (CZE) separations were performed after the injection of large sample volumes by use of a discontinuous buffer system for analyte focusing. Up to 700 nL were injected into a 75 μm i.d. capillary, corresponding to a 23 cm long sample zone. Automated analyses were performed in a commercially available instrument, which was modified to work with a larger pressure drop for hydrodynamic injection. The method was adapted to the determination of a low‐molecular‐weight enzyme inhibitor, DuP 714, in aqueous samples and a structurally related test compound in extracts from plasma samples. The separation system based on a coated capillary was stable and reproducible over several weeks use for aqueous samples, but the analysis of large volumes (> 600 nL) of solid‐phase extracts from plasma, containing acetonitrile, indicated that there is a need for more stable coatings or more extensive sample cleanup. Calibration curves are presented for the test substances, showing a linear relationship between the area ratio of the solute vs. an internal standard and the concentration. Samples containing 50–100 nmol L−1 of solute could be successfully analyzed by CZE with UV detection at 215 nm, approaching levels that are relevant for bioanalytical applications.
Micellar electrokinetic capillary chromatography with in situ charged micelles: II. Evaluation and comparison of octylmaltoside and octylsucrose surfactants as anionic borate complexes in the separation of herbicides
Authors: Smith Joel T. , Rassi Ziad El
Published: May 2005

This report is an extension of our previous work involving the development of in situ charged micellar phases with adjustable surface charge density for micellar electrokinetic capillary chromatography (MECC) of neutral and charged herbicides. The micelles evaluated here are basically alkyldisaccharide‐borate complexes in which the surface charge density can be conveniently varied by changing the operating parameters such as borate concentration and/or pH of the running electrolyte. The two alkyldisaccharide surfactants (i.e., octyl‐β‐D‐maltopyranoside and octylsucrose), having the same alkyl tail but differing in the nature of the sugar polar head group, were compared and characterized over a wide range of conditions using neutral and acidic herbicides as model solutes. The effects of the operating parameters are discussed in terms of mobility, elution range parameter, capacity factor, peak capacity, and separation efficiency. The retention energetics of the micellar phases were studied using two homologous series, alkylphenylketones and alkylbenzenes. At constant micellized surfactant concentration, the two in situ charged micellar phases exhibited homoenergetic retention behavior toward the homologous solutes. On the other hand, even though the two surfactants differed by the nature of one sugar residue in their polar head groups, the micelles exhibited different hydrophobic character, with octylmaltoside yielding higher retention.
Chemiluminescence detection in capillary electrophoresis
Authors: Baeyens Willy R. G. , Ling Betty Lin , Imai Kazuhiro , Calokerinos Anthony C. , Schulman Stephen G.
Published: May 2005

Capillary electrophoresis techniques offer high plate numbers and are highly suited for the efficient separation of a wide variety of chemical components in diverse matrices. Because of the small capillary and detection cell dimensions, together with the minute volumes of samples to be injected, sensitive detection devices based on different physicochemical principles are being developed by various scientific groups and companies. The nature, possible applications and limitations of chemiluminescence as a detection technique are outlined in the present manuscript. The technique so far has only been explored by a limited number of research groups, and serious developments are to be expected for the coming years.
Characterization of continuous electrophoretic separations in narrow channels coupled to small bore capillaries
Authors: Mesaros Jody M. , Ewing Andrew G.
Published: May 2005

Continuous electrophoretic separations in narrow channels have been carried out by coupling conventional capillary zone electrophoresis to open channel structures with rectangular cross sections. Presented here is an examination of the results of continuous separations conducted under various experimental conditions. The characterization is conducted using analysis of both continuous and plug injections of material into the channel, and the parameters used to analyze the separation are lateral dispersion, longitudinal dispersion, and signal intensity. Longitudinal dispersion indicates the amount of band broadening in the direction parallel to channel flow and, therefore, determines the spatial resolution of the separation. Lateral dispersion corresponds to band broadening perpendicular to channel flow and affects the accuracy with which the time of sample introduction into the channel can be determined. The results from these experiments indicate that (a) a cooled channel system provides better results when longer analyses are conducted, (b) a capillary step rate yielding a band introduction angle of 45 degrees relative to the direction of flow in the channel provides the best compromise between longitudinal and lateral dispersions (this value typically equals 0.9 s/25‐μm step for the system used in this research), (c) a capillary to channel linear velocity ratio of 3 to 5 yields improved signals relative to lower ratios due to more sample introduced (velocity ratios above this may lead to loss of spatial resolution), and (4) fast channel flows yield more symmetrically shaped bands than do slower flows due to more efficient transfer of material from the capillary‐channel junction into the channel. Detection limits of 41 μM are obtained with a linear range from 0.12 mM to 1.9 mM for laser induced fluorescence detection.
Electrochemical detection in open tubular column supercritical fluid chromatography using a platinum microelectrode and CO2/water as mobile phase
Authors: Almquist Susanne R. , Nyholm Leif , Markides Karin E.
Published: May 2005

A miniaturized electrochemical detector for microcolumn separations has been developed. The detector was used in open tubular column supercritical fluid chromatography (SFC) with a mobile phase consisting of supercritical carbon dioxide with water below saturation. The detector is compatible with pressure programmed conditions, as is illustrated by the separation of ferrocene, acetylferrocene, and benzoylferrocene.
Electrokinetic chromatography of diterpenoid alkaloids from Aconitum sinomontanum Nakai
Authors: Song Liguo , Zhang Suoming , Ou Qingyu , Yu Weile
Published: May 2005

The separation of a hydrophobic mixture of diterpenoid alkaloids from Aconitum sinomontanum Nakai was studied using various modes of electrokinetic chromatography (EKC), such as SDS micellar EKC, methanol or N,N‐dimethylformamide modified micellar EKC, β‐cyclodextrin modified micellar EKC, mixed micellar EKC with SDS and PEG 400 monolaurate, and microemulsion EKC with SDS, n‐octane and n‐butanol. Mixed micellar EKC was found to be the most preferred approach.
An on‐line coupled HPLC‐HRGC system for the quantitative characterization of oil fractions in the middle distillate range
Authors: Beens Jan , Tijssen Robert
Published: May 2005

A commercially available HPLC‐HRGC instrument was adapted to enable the full quantitative characterization of oil fractions in the range 150–400°C. The HPLC separates the sample into five fractions: saturates, mono‐aromatics, di‐aromatics, fluorenes + dibenzothiophenes, and tri‐aromatics. These fractions are subsequently quantitatively transferred via an on‐column interface to the HRGC part of the system. This transfer is performed into an empty, wide‐bore precolumn (retention gap), which enables a refocussing effect of the compounds of interest in the tail of the HPLC mobile phase, which acts as a solvent in the GC. A solvent vapor exit in the system enables the vent of the major part of this solvent. The final HRGC separation provides a carbon distribution of the saturates and the mono‐aromatics and enables the identification of a number of compounds in the other three fractions. It is demonstrated that the described method is quantitative for the hydrocarbons, but also for sulphur‐containing compounds in only those samples that have a low sulphur content. © 1995 John Wiley & Sons, Inc.
Separation of basic drugs by capillary electrophoresis using selectively modified cyclodextrins as chiral selectors
Authors: Weseloh Gerald , Bartsch Holger , König Wilfried A.
Published: May 2005

The influence of seven differently methylated β‐cyclodextrin derivatives and of pure β‐cyclodextrin (β‐CD) on the enantiomeric resolution by capillary electrophoresis of six basic chiral pharmaceuticals is investigated. The methyl substitution pattern affects enantioselectivity much more than other experimental parameters. The purity of the used cyclodextrin derivatives is analyzed by successive hydrolysis, reduction, acetylation, and GC/MS of each CD derivative and by MALDI‐TOF mass spectrometry. © 1995 John Wiley & Sons, Inc.
Large‐volume on‐column injections for gas chromatography
Authors: Ramalho Silvia , Hankemeier Thomas , de Jong Marco , Th. Brinkman Udo A. , Vreuls René J. J.
Published: May 2005

Large‐volume injection is an attractive means to improve detection limits when analyzing dilute sample extracts. There is now no need to achieve enrichment by means of solvent evaporation, which makes the total analytical procedure less reliable and less robust due to loss of volatile compounds. In this study on‐column injection was applied for large‐volume injection using an on‐column injector in combination with a deactivated uncoated fused silica capillary (retention gap) and an early solvent vapor exit. Two strategies are described. The first one relies on the programmable speed of an infusion pump, which is adapted such that it lies just above the evaporation rate of the extraction solvent used. With the second procedure, which can be used for a commercially available autosampler, the evaporation speed is adjusted to the fixed speed of injection by varying the temperature during injection. During optimization the additional solvent evaporation time was determined. The optimum conditions for an injection volume of 100 μL of either n‐hexane or ethyl acetate are reported. Large‐volume injection was used for simplified and miniaturized solid‐phase extraction procedures. The procedures were used to determine various organic micropollutants, such as organophosphorus pesticides and triazine herbicides, in tap and surface water extracts, using a flame photometric, and a mass spectrometric detector. For both methods good recovery for most of the analytes (70–87%), linear calibration curves (0.01‐5 μg/L range), and relative standard deviations of less than 10% were obtained. Detection limits typically were in the range of 1–10 ng/L for GC‐FPD and 10–150 ng/L for GC‐MS. When working in the time‐scheduled multiple ion detection mode detection limits in GC‐MS were one order of magnitude lower. © 1995 John Wiley & Sons, Inc.
GC instrumentation for on‐column injection of large volumes: Automated optimization of conditions
Authors: Munari Fausto , Colombo Pier Albino , Magni Paolo , Zilioli Giacinto , Trestianu Sorin , Grob Konrad
Published: May 2005

Improved instrumentation facilitates on‐column injection of up to several hundreds of microliters onto GC capillary columns. It incorporates an autosampler with adjustable injection speed, a standardized precolumn system, an early vapor exit, and software that models evaporation of a given solvent at the flow and temperature conditions chosen by the user. The software calculates the appropriate injection speed, guides the autosampler correspondingly, and closes the vapor exit at a moment leaving in the precolumn the amount of unevaporated solvent that is selected by the user. © 1995 John Wiley & Sons, Inc.
Cyanobiphenyl‐substituted polymethylsiloxane encapsulated particles for packed capillary column supercritical fluid chromatography
Authors: Shen Yufeng , Li Wenbao , Malik Abdul , Reese Shawn L. , Rossiter Bryant E. , Lee Milton L.
Published: May 2005

Nine isomeric cyanobiphenyl‐substituted (25%) polymethylsiloxane (CBP) stationary phases were coated and immobilized by free‐radical crosslinking on silica packing materials for use in supercritical fluid chromatography (SFC). The selectivities of these packing materials to benzene derivatives, polycyclic aromatic hydrocarbons (PAHs), and double bonds in fatty acid methylesters (FAMEs) were determined. Among the nine isomeric CBP‐coated packing materials, the o, p‐CBP phase was found to be the most selective to both double bonds and aromatic isomers under SFC conditions. The durability of the packing materials was evaluated by measuring the changes in selectivity with SFC use. The loss in selectivity was less than 0.20% after being continuously washed by supercritical carbon dioxide at 100°C and 300 atm for more than 100 h.
Abnormal vestibuloocular reflex cancellation in multiple system atrophy and progressive supranuclear palsy but not in Parkinson's disease
Authors: Rascol O. , Sabatini U. , Fabre N. , Senard J. M. , Simonetta‐Moreau M. , Montastruc J. L. , Clanet M. , Rascol A.
Published: May 2005

We have measured the gain of the vestibuloocular reflex (VOR) in darkness and its cancellation by fixation in 37 patients with Parkinson's disease (PD), 26 patients with multiple system atrophy (MSA), 11 patients with progressive supranuclear palsy (PSP), and 19 normal volunteers. The capacity to cancel the VOR by fixation (VOR cancellation) was significantly reduced in the MSA and PSP patients compared with the PD and normal subjects (p < 10−4). A VOR cancellation < 90% (i.e., the mean VOR cancellation of the normals ‐ 2 SD) was present in four PD patients, 23 MSA patients, and 11 PSP patients. This criteria distinguished PD and MSA with a 89% sensitivity and a 89% specificity. Our results demonstrate that the VOR cancellation is impaired in most patients with MSA and PSP but not with PD. In MSA patients, the abnormal VOR cancellation is probably not related to the nigrostriatal dopaminergic deficit and more likely reflects a cerebellar dysfunction. Impaired VOR cancellation is a clinical criteria to differentiate MSA and PSP from PD.
A controlled investigation of current and premorbid personality: Characteristics of Parkinson's disease patients
Authors: Glosser Guila , Clark Christopher , Freundlich Bruce , Kliner‐Krenzel Lori , Flaherty Phyllis , Stern Matthew
Published: May 2005

It has been suggested that before development of motor symptoms, Parkinson's disease (PD) patients with idiopathic display a specific cluster of personality traits consisting of increased rigidity, conscientiousness, industriousness, orderliness, and cautiousness. The idea of such a distinctive premorbid personality profile remains controversial. This hypothesis was reexamined using a methodology that expands on previous studies. Patients with idiopathic PD, probable Alzheimer's Disease (AD), and medical controls with nonneurological chronic progressive motor disorders were rated by a close relative on the NEO‐Personality Inventory (PI) to compare current and premorbid personality profiles. For PD and control subjects, current and past self‐ratings were also obtained. Results do not support the postulated distinctive PD personality either premorbidly or following onset of symptoms. Both in terms of the premorbid personality profile and perceived changes in personality postdating the onset of illness, PD patients are similar to AD patients. Though not differing from medical controls premorbidly, after developing symptoms, PD patients were described as less extroverted; less exploratory and curious; and less organized, goal directed, and disciplined.
Prevalence of Parkinson's disease in junín, Buenos Aires province, argentina
Authors: Melcon Mario O. , Anderson Dallas W. , Vergara Rodolfo H. , Rocca Walter A.
Published: May 2005

We investigated the prevalence of Parkinson's disease (PD) in a South American city: Junín, Buenos Aires Province, Argentina. At dwellings systematically selected, the case finding involved household screenings and neurological examinations (i.e., a two‐phase survey approach). Only persons 40 years of age or older were eligible (N = 7,765). There were 51 cases of PD identified, yielding a crude prevalence of 656.8 per 100,000 population. The age‐specific prevalence was consistently higher in men than women, and it increased with advancing age for both sexes. In addition to prevalence figures, we present tallies related to clinical features of PD, as well as tallies related to other subtypes of parkinsonism.
A controlled trial of fluoxetine in nondepressed patients with Huntington's disease
Authors: Como Peter G. , Rubin Allen J. , O'Brien Chris F. , Lawler Kathy , Hickey Charlyne , Rubin Ann E. , Henderson Robin , McDermott Michael P. , McDermott Maria , Steinberg Kim , Shoulson Ira
Published: May 2005

To examine the antidepressant specificity of fluoxetine in Huntington's disease (HD), we carried out a randomized, double‐blind, placebo‐controlled trial of this medication in nondepressed HD patients. Thirty patients with early HD who were not depressed (Hamilton Depression Inventory <16) were randomized to placebo (N = 13) or fluoxetine 20 mg/day (N = 17) and were followed up for 4 months. Outcome measures included changes in total functional capacity (TFC) and in standardized neurological, cognitive, and behavioral ratings. After adjustment for the higher education level found in the placebo group at baseline, no differences between the treatment groups were found in TFC, neurological, or cognitive ratings. Fluoxetine‐treated patients did show a slight reduction in agitation and in the need for routine. Although fluoxetine may be a useful antidepressant in depressed HD patients, it failed to exert substantial clinical benefits in nondepressed HD patients.
Evidence for a new spinocerebellar ataxia locus
Authors: Higgins J. J. , Pho L. T. , Ide S. E. , Nee L. E. , Polymeropoulos M. H.
Published: May 2005

The autosomal dominant ataxias (ADA) are a diverse group of multisystem, neurodegenerative disorders characterized by mutations at several chromosomal loci (SCA types 1–5, SCA type 7, DRPLA). We excluded all the known SCA loci by mutational and linkage analyses in an American family of British origin with ADA and document that an additional ataxia locus must exist. The clinical characteristics and ethnic origin of our family are similiar to the British Drew family of Walworth with the SCA type 3 mutation and differ from other families without a known ataxia locus. Individuals in our family and the Drew family initially show signs of ataxia but may develop variable degrees of ophthalmoplegia, Parkinsonian features and central demyelination. The phenotypic diversity in families without a known ataxia locus suggests that there may be several other undefined ataxia loci.
Posttraumatic movement disorders after moderate or mild head injury
Authors: Krauss Joachim K. , Tränkle Rolf , Kopp Karl‐Heinz
Published: May 2005

We examined the occurrence of posttraumatic movement disorders after moderate or mild head injury with a three‐level follow‐up study including questionnaires, telephone interviews, and personal examinations 4–6 years after the trauma (mean 5.2 years). Sixteen of 158 patients (10.1%) for whom a detailed follow‐up was available had developed movement disorders most probably related to craniocerebral trauma. The most frequent finding was a low‐amplitude postural/intention tremor that appeared to resemble enhanced physiological or essential tremor. Twelve patients reported transient tremor, two patients had persistent tremor, one patient had transient tremor and persistent hyperekplexia, and another patient had mild persistent cervical myoclonic twitches. Overall, the movement disorder was transient in 12 patients (7.6%) and persisted in only 4 patients (2.6%). These movement disorders were not disabling and did not require medical therapy. Taking into account possible bias by selection of the sample group, the frequency of movement disorders secondary to moderate or mild head trauma might be lower than 10.1%. Posttraumatic movement disorders occurred significantly more often in the group of patients with Glasgow Coma Scores between 9 and 14 than in those with a score of 15. Severe movement disorders such as low‐frequency kinetic tremor or hemidystonia were not identified in this survey.
Teaching tape for the motor section of the toronto western spasmodic torticollis scale
Authors: Comella Cynthia L. , Stebbins Glenn T. , Goetz Christopher G. , Chmura Teresa A. , Bressman Susan B. , Lang Anthony E.
Published: May 2005

The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) assesses the character and severity of cervical dystonia (CD). We developed a teaching tape of the TWSTRS scoring for the motor symptoms of CD. The tape provides investigators with visual representations of each component of the motor section of the TWSTRS as agreed upon by three independently scoring raters. The rate of agreement for the nondichotomous components was always significant, with a Kendall's coefficient of concordance W ranging between 0.98 and 0.76 (p < 0.01 for all measures). For the two dichotomous components, a weighted k coefficient was also significant at 0.86 for lateral shift and 0.89 for sagittal shift (p < 0.01 for both measures). Scale deficiencies identified by the raters were an explicit definition of midline for assessment of range of motion, the absence of a separate scoring category assessing dystonic tremor, and the specification of duration for the effect of sensory tricks. These observations should be taken into account in future revisions of the TWSTRS and in refinements of other rating scales for CD.
Gait initiation in parkinson's disease
Authors: Rosin Regina , Topka Helga , Dichgans Johannes
Published: May 2005

We studied the kinematic patterns of gait initiation in 31 patients with Parkinson's disease and in 20 age‐ and sex‐matched normals by using an optoelectronic tracking system (ELITE). Position markers were attached to the skin overlying the ankle, knee, hip, elbow, shoulder, and zygomatic bone. Subjects were instructed to start walking immediately after an acoustic go signal. Gait initiation was defined as the phase between standing motionless and steady‐state locomotion. This phase was subdivided into a movement preparation period (the time between go signal and movement onset) and a movement execution period (the time between movement onset and the end of the first stride). Onset and duration of ankle, knee, hip, trunk, and arm motion within the first stride were analyzed. Movement preparation time was significantly increased in Parkinson's disease (p = 0.01), whereas movement execution times were similar in both groups (p = 0.23). Initiation of ankle, knee, hip, arm, and trunk movements was delayed in patients as compared with healthy subjects, but the relative timing and the sequence of submovements was comparable in both groups, indicating that the overall pattern of submovements was preserved in the patients. Our data suggest that gait initiation deficits in Parkinson's disease cannot be explained by a disordered sequence of limb and trunk submovements. More likely, gait initiation problems originate from the basal ganglia's internal cueing deficit for movement sequences, delaying onset and slowing the execution of all subcomponents.
Cerebral glucose metabolism in corticobasal degeneration: Comparison with progressive supranuclear palsy and normal controls
Authors: Nagahama Yasuhiro , Fukuyama Hidenao , Turjanski Nora , Kennedy Angus , Yamauchi Hiroshi , Ouchi Yasuomi , Kimura Jun , Brooks David J. , Shibasaki Hiroshi
Published: May 2005

The regional metabolic rate of glucose was estimated using 18F‐labeled 2‐deoxyglucose and positron‐emission tomography (PET) in eight patients with corticobasal degeneration (CBD). Measures of cerebral glucose metabolism in these patients were compared with those for nine age‐matched normal controls and eight patients with progressive supranuclear palsy (PSP). Compared with that in the normal controls, the CBD patients showed significantly reduced cerebral glucose metabolism in the contralateral hemisphere to the clinically most affected side in the dorsolateral frontal, medial frontal, inferior parietal, sensorimotor, and lateral temporal cortex, as well as in the corpus striatum and the thalamus. In comparison with that in PSP, in CBD the glucose metabolism in the contralateral hemisphere was significantly decreased in the in ferior parietal, sensorimotor, lateral temporal cortex, and the corpus striatum. These results confirm the marked asymmetric cerebral involvement in CBD and suggest that there are significant differences between CBD and PSP in the cerebral metabolism in some cerebral regions such as the inferior parietal cortex and sensorimotor cortex, which might reflect the differences in their clinical characteristics.
Ethnic variation in the clinical expression of idiopathic torsion dystonia
Authors: Almasy Laura , Bressman Susan , de Leon Deborah , Risch Neil
Published: May 2005

Although childhood, limb‐onset idiopathic torsion dystonia (ITD) is at increased prevalence among Jews, and Ashkenazi Jews with this form of ITD show linkage disequilibrium for a unique haplotype, little else is known about phenotypic or genetic variation in ITD among ethnic groups. We assessed clinical features in 786 ITD patients and determined the relative frequencies of various clinical forms of ITD in the major ethnic groups. Several differences in age‐at‐onset and site‐at‐onset distributions among groups were demonstrated. As expected, Ashkenazi Jews had an earlier age‐at‐onset distribution than did non‐Jewish Caucasians. In the early‐onset group, Jews were less likely to have cervical onset and more likely to have onset in the limbs than were non‐Jewish Caucasians (p < 0.01). Among late‐onset cases, Jews had less cervical onset and more cranial onset than did non‐Jewish Caucasians (p < 0.01). African‐Americans showed suggestive differences in both age at onset and site at onset as compared with the two Caucasian groups, with an intermediate age at onset, a deficit of leg onset, and an excess of cranial and larynx onset. Subgroups of non‐Jewish Caucasians showed no significant differences from each other. The observed ethnic variations in age at onset and site at onset of ITD suggest population differences in disease‐causing alleles or loci. However, environmental influences on expression of ITD can not be excluded.
Proton magnetic resonance spectroscopy in steele‐richardson‐olszewski syndrome
Authors: Davie Charles A. , Barker Gareth J. , Machado Christine , Miller David H. , Lees Andrew J.
Published: May 2005

Proton magnetic resonance spectroscopy, localized to the lentiform nucleus, was carried out in nine patients with a clinical diagnosis of Steele‐Richardson‐Olszewski syndrome (SRO) and in eight healthy age‐matched controls. Three of the nine SRO patients had a so‐called “eye of the tiger sign” with high signal in the globus pallidus surrounded by a ring of low signal on T2 weighted magnetic resonance imaging previously only reported in Hallervorden‐Spatz disease. One of these patients had pathologically proven SRO at postmortem. The SRO group showed a significant reduction in the median concentration from N‐acetyl groups (median, 6.87 mM; range, 4.92–10.59 mM; p < 0.015) compared with the control group (median, 9.85 mM; range, 9.26–11.0 mM). The N‐acetylaspartate concentration was significantly reduced in seven of the nine patients studied. The reduction of the N‐acetylaspartate‐creatine ratio from the lentiform nucleus in the SRO group may reflect neuronal loss, occurring predominantly in the globus pallidus. Proton magnetic resonance spectroscopy may be a useful, noninvasive technique to help differentiate the various parkinsonian syndromes.
Interlimb coordination deficits in patients with parkinson's disease during the production of two‐joint oscillations in the sagittal plane
Authors: Swinnen S. P. , van Langendonk L. , Verschueren S. , Peeters G. , Dom R. , de Weerdt W.
Published: May 2005

TwoK. U. Leuven, Heverlee, Belgiumlimb coordination patterns involving cyclical flexionK. U. Leuven, Heverlee, Belgiumextension movements, performed in the same or in different directions, were studied in patients with Parkinson's disease and a group of elderly subjects. The three patterns referred to the homologous (both arms or legs), homolateral (right or left arm and leg), and heterolateral (right arm and left leg or vice versa) limb segment combinations that were performed in the sagittal plane from a seated position. Findings revealed that interlimb coordination deficits were evident in patients with Parkinson's disease. Moreover, mean cycle duration and its variability were increased, particularly during the production of nonhomologous limb movements in different directions. These temporal findings suggest that movement slowness was not a primary consequence of an intrinsic inability to move the limb segments at the required speed but rather reflected an intentional strategy to cope with the complexity of the coordination pattern. Finally, movement amplitude was substantially smaller and more variable in patients with Parkinson's disease, suggestive of hypometria during the production of these cyclical tasks.
Parkinsonism associated with acute intracranial hematomas: An [18F]dopa positron‐emission tomography study
Authors: Turjanski Nora , Pentland Brian , Lees Andrew J. , Brooks David J.
Published: May 2005

We present the case of a 36‐year‐old woman with a right temporal hematoma and an overlying subdural hematoma following rupture of a right middle cerebral artery aneurysm. Three weeks after recovering consciousness, she developed a levodopa‐responsive parkinsonian syndrome involving the right limbs. A year after the vascular event, she reported subjective improvement in her parkinsonism, which has remained stable since. 18F‐dopa positron‐emission tomography showed a marked reduction of uptake in the left putamen, raising the possibility that the intracranial hemorrhage unmasked latent Parkinson's disease. To the best of our knowledge, this is the first case of parkinsonism associated with spontaneous acute intracerebral and subdural hematomas.
Living with a person who has parkinson's disease: The Spouse's perspective by stage of disease
Authors: Carter Julie H. , Stewart Barbara J. , Archbold Patricia G. , Inoue Iku , Jaglin Jeana , Lannon Meg , Rost‐Ruffner Elke , Tennis Marsha , McDermott Michael P. , Amyot Donna , Barter Ruth , Cornelius Lisa , Demong Carol , Dobson Judith , Duff Jan , Erickson Judi , Gardiner Nita , Gauger Lisa , Gray Peggy , Kanigan Bernice , Kiryluk Barbara , Lewis Paula , Mistura Kathie , Malapira Teri , Pay Mary , Sheldon Carol , Winfield Linda , Wolfington‐Shallow Kathy , Zoog Kim
Published: May 2005

The objective of this study was to examine the experience of spouses caregiving for their spouse with Parkinson's disease (PD) and to determine whether their experiences differed by stage of disease. By using a cross‐sectional design and mail questionnaire data from 380 spouse caregivers across 23 sites of the Parkinson Study Group, key caregiver variables were examined by stage of PD. Three categories of variables‐caregiver role strain (10 measures), caregiver situation (four measures), and caregiver characteristics (four measures)‐were analyzed by using t tests with Bonferroni correction. Specific types and amounts of role strain accumulated as the disease progressed, and they differed significantly between stages (p < 0.05). In the caregiving situation, the mean number of caregiving tasks tripled by stage 4/5. Negative changes in lifestyle plus decreases in predictability in caregivers' lives increased significantly in late‐stage disease (p < 0.05). Caregiver characteristics of physical health and preparedness did not significantly differ across stages of disease. Depression was significantly higher by stage 4/5. Mutuality, the positive quality of the relationship as perceived by the caregiving spouse, declined beginning at stage 2. Caregiver strain is experienced across all stages of PD and accumulates significantly as the disease progresses. This study defines types and amounts of strain by stage of disease, which will be helpful in designing formal intervention trials to provide more effective help for spouse caregivers.
Abnormalities in the stride length‐cadence relation in parkinsonian gait
Authors: Morris Meg , Iansek Robert , Matyas Thomas , Summers Jeffery
Published: May 2005

The purpose of this investigation was to clarify abnormalities in the stride length‐cadence relation in gait hypokinesia in Parkinson's disease (PD). A second aim was to investigate the effect of levodopa medication on the foot‐step pattern. In the first experiment, 20 subjects with idiopathic PD and 20 age‐, sex‐, and height‐matched controls performed a series of 10 m walking trials at cadence rates ranging from 40 steps/min to 180 steps/min. Cadence rates were set by an electronic metronome, and gait patterns were measured by using a footswitch stride‐analyzer system. By instructing subjects to concentrate on walking in time to the metronome beat, the baseline stride length could be monitored for a range of velocities with the compensatory effects of cadence removed. Linear‐regression analysis revealed that the mean slope for the regression of stride length against cadence was not different form normal in PD, although there was a statistically significant difference in mean intercept between the PD group (0.25) and the control group (0.59); [t (19) = −4.76; p = 0.0001]. The second experiment evaluated the effects of levodopa on stridelength regulation in 10 subjects with idiopathic PD on average 45 min before and after the first morning dose was administred. There was a statistically significant increase in stride length for all cadence rates from premedication to postmedication phases and the maximal stride length was achieved at higher cadence rates after medication. The slope of the regression of stride length against cadence did not alter according to medication status, although the mean intercept was significantly lower before levodopa (‐0.06) compared with after levodopa (0.27); [t (9) = −3.83; p = 0.004]. These results suggest that defective scaling of stride length underlies gait disturbance in PD.
Increased cerebrospinal fluid levels of neurofilament protein in progressive supranuclear palsy and multiple‐system atrophy compared with Parkinson's disease
Authors: Holmberg Björn , Rosengren Lars , Karlsson Jan‐Erik , Johnels Bo
Published: May 2005

More reliable tools are needed for the differentiation of Parkinson's disease (PD) from other parkinsonian disorders. The neurofilament protein (NFL) and the glial fibrillary acidic protein (GFAP) are main structural proteins of axons and fibrillary astroglial cells. By using enzyme‐linked immunosorbent assays, these proteins were quantified in the cerebrospinal fluid (CSF) of 49 patients referred to the Department of Neurology for diagnostic consideration or treatment of parkinsonism of different etiologies. All patients were first diagnostically evaluated by strict clinical criteria. The procedure included a neurologic and neuro‐ophthalmologic examination as well as computed tomography or magnetic resonance imaging. These were performed independently and in advance of the CSF analysis. A total of 19 patients were diagnosed as having PD, 12 had progressive supranuclear palsy (PSP), and 10 had multiple‐system atrophy (MSA). Eight were diagnosed as having other diseases, such as arteriosclerotic parkinsonism and undefined parkinsonian syndromes. The content of NFL was significantly higher both in the PSP group (p < 0.001) and in the MSA group (p < 0.0001) compared with the PD group. The high values of NFL indicate an ongoing neuronal degeneration affecting mainly the axonal compartment in the PSP and MSA groups, whereas there was no difference in glial involvement as measured by GFAP in the PD, PSP, and MSA groups. There was a relation between high CSF levels of NFL in the various patient groups and the occurrence of pyramidal symptoms (p < 0.001), possibly reflecting the axonal damage to the corticospinal tract. Furthermore, mortality at 24‐month follow up was associated with high NFL levels (p < 0.01). We conclude that analysis of NFL in CSF may become useful in the differential diagnosis of parkinsonian syndromes.
Subtle involuntary movements are not reliable indicators of incipient Huntington's disease
Authors: Boo Gerly De , Tibben Aad , Hermans Jo , Maat Anneke , Roos Raymund A. C.
Published: May 2005

In the past, Huntington's disease was diagnosed when movement disturbances were present in concordance with a positive family history. Early motor signs, however, are often not found in a standard neurologic examination, and their expression is variable. Not until later stages of the disease could one be sure about the diagnosis. Since genetic diagnosis became available, the onset of symptoms and signs could be studied in the earliest phase. The aim of the study was to evaluate observer agreement of the assessment of early motor signs in Huntington's disease. A total of 17 gene carriers, 22 noncarriers, and eight partners were recorded on video performing several facial movements after instruction and engaging in a 5‐minute conversation. Three experienced neurologists, unaware of the genetic status of the participants, judged and classified the video recordings independently. The cases with disagreement were judged a second time after the neurologists discussed these cases. The observer agreement after the first judgment is poor (kappas 0.09, 0.24, 0.45) and after the second judgment satisfactory (kappas 0.79, 0.90, 0.78). Consequences for clinical practice and research programs into early symptoms and signs are discussed.
Alterations of motor cortical inhibition in patients with dystonia
Authors: Rona Sabine , Berardelli Alfredo , Vacca Laura , Inghilleri Maurizio , Manfredi Mario
Published: May 2005

Cortical inhibitory mechanisms were investgated with the technique of paired transcranial magnetic stimulation in 10 patients with dystonia of the right arm: six patients had focal, task‐specific dystonia (writer's cramp) and three had segmental and one had generalized dystonia. Paired stimuli were delivered in a conditioning‐test design during slight voluntary activation of the target muscle, with subthreshold conditioning stimuli at short intervals (3‐20 ms) and suprathreshold conditioning stimuli at long intervals (100‐250 ms). The amount of inhibition at short interstimulus intervals did not differ significantly between patients and normal subjects. With long interstimulus intervals, patients showed more inhibition of the test response, which was significant at the 150‐ms interval. The cortical silent period following a single suprathreshold magnetic stimulus was slightly shorter in patients. No significant difference was detected between the affected side and the unafected side in patients with unilateral task‐specific dystonia, neither in the duration of the silent period nor in the respnse to paired magnetic stimuli. These results indicate that the different types of motor cortical inhibition are produced by different inhibitory circuits. We propose that the alterations observed in patients with dystonia are the result of impaired feedback from the basal ganglia to motor cortical areas, with the ultimate effect of a flattening of the excitability curve of the cortical motoneuron pool during voluntary muscle activation.
Kappa‐opioid receptor agonists increase locomotor activity in the monoamine‐depleted rat model of parkinsonism
Authors: Hughes Neill R. , McKnight Alexander T. , Woodruff Geoffrey N. , Hill Michael P. , Crossman Alan R. , Brotchie Jonthan M.
Published: May 2005

Excessive glutamate transmission in the basal ganglia is a major factor in the neural mechanisms underlying parkinsonian akinesia. Activation of K opioid receptors causes a presynaptic reduction in glutamate release. K opioid receptors are concentrated in those regions of the basal ganglia associated with increased glutamate transmission in parkinsonism. In this study, we use the α‐methyl‐p‐tyrosine and reserpine‐treated rat model of parkinsonism to investigate whether systemic administration of the K opioid agonists enadoline (CI‐977) and U69,593 can alleviate the symptoms of parkinsonism either alone or in conjunction with dopamine replacement therapy. We report that, when administered alone, both enadoline and U69,593 can increase locomotion in monoamine‐depleted rats. No increase in locomotor activity was seen after K opioid agonist administration in non‐parkinsonian rats. The responses to K opioid agonists were blocked by co‐administration of either the nonspecific opioid receptor antagonist naloxone or the selective K opioid receptor antagonist nor‐binaltorphimine (nor‐BNI). An important finding is that when enadoline and L‐dopa administered togethe, their anti‐akinetic properties are synergistic. Thus, the doses of enadoline and L‐dopa required to alleviate akinesia when administered together are lower than either administered alone. These data illustrate the importance of K opioid receptors in the neural mechanisms controlling voluntary movement and suggest that K opioid agonists may have a role as adjuncts to dopamine replacement in the management of Parkinson's disease.
Clinical impairment of sequential finger movements in Parkinson's disease
Authors: Agostino Rocco , Berardelli Alfredo , Currà Antonio , Accornero Neri , Manfredi Mario
Published: May 2005

A retrospective analysis was performed on the records of 33 off‐therapy parkinsonian patients. We analyzed the clinical score of three sequential upper limb movements: finger tapping, hand opening and closing, and forearm pronation and supination. The records showed that nearly all patients had difficulty in performing all three motor tasks, but movement scores showed that they found the sequential finger‐tapping task significantly more difficult than the other two tasks. We suggest that parkinsonian patients find individual finger movements more difficult to execute than gross hand movements because‐owing to their abnormal basal ganglia output‐they lack the finer cortical control and greater facilitation that the finger task demands.
Do visual‐evoked potentials and spatiotemporal contrast sensitivity help to distinguish idiopathic Parkinson's disease and multiple system atrophy?
Authors: Delalande I. , Hache Jc. , Forzy G. , Bughin M. , Benhadjali J. , Destée A.
Published: May 2005

A large number of patients with Parkinson's disease were reported to have abnormal visual‐evoked potentials (VEPs) and spatiotemporal contrast sensitivity (STCS) suggesting dopaminergic deficiency in the visual pathway, probably the retina. Until now, VEPs and STCS have not been studied in multiple system atrophy (MSA). We investigated 12 patients with idiopathic Parkinson's disease (IPD) and 12 patients with MSA. The age medians were 64.5 years for IPD and 63.5 years for MSA. None of the patients showed any ocular disease that could interfere with the results. Checkboard VEPs and STCS measurements to horizontal sinusoidal gratings were evaluated. Statistical analysis was performed, including Student's t test and two‐ or three‐way analysis of variance. A significant interocular difference in spatial contrast sensitivity was observed in IPD, which was not present in MSA. VEPs were not delayed in MSA, whereas latency of the major component and the second negative deflection were increased in IPD. VEPs and STCS measurements might provide useful help for distinguishing IPD from MSA.
Rarity of debrisoquine hydroxylase gene polymorphism in chinese patients with Parkinson's disease
Authors: Pang Chi P. , Zhang Jun , Woo Jean , Chan Daniel , Law Lap K. , Tong Shirley F. , Kwok Timothy , Kay Richard
Published: May 2005

Impaired debrisoquine metabolism resulting from defects in the cytochrome P450 CYP2D6‐debrisoquine hydroxylase gene has been shown to be associated with the development of Parkinson's disease(PD). We studied two polymorphisms in this gene in 207 Chinese PD patients and 227 control subjects by polymerase chain reaction and restriction analysis. The G to A substitution at position 1934 in the junction of intron 3/exon 4 was detected in one sporadic PD patient and two control subjects, all of whom were heterozygous. The single base deletion at position 2637 in exon 5 was not detected in any of the study subjects. Such rarity of CYP2D6 polymorphism indicates PD in the Chinese population is associated with some other gene defects.
Confirmation of the antidyskinetic effect of posteroventral pallidotomy by means of an intraoperative apomorphine test
Authors: Merello Marcelo , Cammarota Angel , Nouzeilles Maria I. , Betti Osvaldo , Leiguarda Ramón
Published: May 2005

We present a series of six consecutive Parkinson's disease patients undergoing posteroventral pallidotomy (PVP), who received an apomorphine injection after thermolesioning the posteroventral region of the internal globus pallidus (GPi) to evaluate the effect of the lesion on drug‐induced dykinesias and therefore to proceed with further lesions or to conclude the surgery. Five of six patients failed to present dykinesias or did so to a significantly lesser degree (F [2, 10] 42.6; p < 0.0001) so that surgery was concluded. One patient continued having contralateral dyskinesia despite an improvement in rigidity and bradykinesia, therefore, a new track was performed followed by a new lesion. No differences were found between intrasurgical and 1‐month postoperative apomorphine test values. This report indicates that the use of an apomorphine test after thermolesioning may provide a reliable tool to check lesion efficacy on dyskinesia. The development of techniques that provide additional clinical information to the electrophysiological recording could help improve the outcome of patients undergoing pallidotomy.