bluuebunny/crossref_metadata_2025 huggingface dataset:
A new method for the preparation of polymeric porous layer open tubular columns for GC application
Authors: Shen Thomas C. , Wang Mei‐Ling
Published: May 2005

A new method to prepare polymeric PLOT columns by using in situ polymerization technology is described. The method involves a straightforward in situ polymerization of the monomer. The polymer produced is directly coated on the metal tubing. This eliminates many of the steps needed in conventional polymeric PLOT column preparation. Our method is easy to operate and produces very reproducible columns, as shown previously (T. C. Shen, J. Chromatogr. Sci. 30, 239, 1992). The effects of solvents, tubing pretreatments, initiators and reaction temperatures in the preparation of PLOT columns are studied. Several columns have been developed to separate (1) highly polar compounds, such as water and ammonia or water and HCN, and (2) hydrocarbons and inert gases. A recent improvement has allowed us to produce bonded polymeric PLOT columns. These were studied, and the results are included also. © 1995 John Wiley & Sons, Inc.
Applications of reversed‐phase high performance liquid chromatography using enhanced‐fluidity liquid mobile phases
Authors: Lee Stephen T. , Olesik Susan V. , Fields Steven M.
Published: May 2005

Enhanced‐fluidity liquid mobile phases (methanol/H2O/CO2) were used as eluents in reversed‐phase HPLC. The low pressure drop across the column allowed serial connection of micro‐scale columns to achieve the efficient separation of a coal tar sample. Other applications such as the separation of fat soluble vitamins and probucol and related compounds are shown. © 1995 John Wiley & Sons, Inc.
Enantiomer separations using chloroacyl pentyl cyclodextrins as chiral GC stationary phases
Authors: Shitangkoon Aroonsiri , Vigh Gyula
Published: May 2005

Chloroacyl pentyl β‐cyclodextrin derivatives were synthesized for use as gas chromatographic stationary phases. Capillary columns of identical phase ratios were prepared with the liquid undiluted monochloro‐, dichloro‐, and trichloroactyl phases and the respective column efficiency, capacity factor, and separation selectivity values were determined. For most of the enantiomeric pairs studied, monochloroacetyl pentyl β‐cyclodextrin (M) offers the highest selectivity values, though at the expense of large capacity factors (long analysis times) and low column efficiencies. Dichloroacetyl pentyl β–cyclodextrin (D) provides a good compromise between sufficiently high chiral selectivities and acceptable column efficiencies. Trichloroacetyl pentyl β‐cyclodextrin (T) permits the preparation of very efficient columns, but offers lower chiral selectivities than the other two chloroacyl derivatives. © 1995 John Wiley & Sons, Inc.
Variation of selectivity among the poly(siloxane) stationary phases for gas chromatography
Authors: Poole Salwa K. , Miller Kenneth G. , Poole Colin F.
Published: May 2005

The solvation parameter model is used to characterize the solvent properties of 12 poly(siloxane) stationary phases of varied structure. Selectivity differences are explained in terms of differences in the cohesive energy of the solvents and their capacity for dispersion, dipole‐type, hydrogen bonding, and electron pair complexation interactions. None of the poly(siloxane) stationary phases exhibited significant hydrogen‐bond acid character. Principal component analysis indicates that replacing a methyl group by a phenyl group in the poly(siloxane) backbone predominantly produces incremental increases in the capacity of the stationary phase for dipole‐type interactions (up to about 50 mol% phenyl groups with only small changes at higher phenyl composition). The poly(methylphenylsiloxanes), however, only span a small sector of the selectivity space and provide limited opportunities for selectivity optimization. OV—275 and QF‐1 are identified as important phases with unique characteristics—OV‐275 because of its high cohesive energy and great capacity for dipole‐type and solvent hydrogen‐bond base interactions and QF‐1 because of its unusually small hydrogen‐bond basicity for a phase with an intermediate capacity for dipole‐type interactions as well as a low capacity for n‐ and π‐electron complexation interactions. From these studies it is possible to speculate on the needs for new phases to explore the full selectivity potential of gas chromatography and to address the issue of temperature and its relationship to selectivity. © 1995 John Wiley & Sons, Inc.
Synthesis and use of a novel chiral surfactant based on (R,R)‐tartaric acid and its application to chiral separations in micellar electrokinetic capillary chromatography (MECC)
Authors: Dalton Desmond D. , Taylor David R. , Waters David G.
Published: May 2005

This article describes the synthesis of a novel chiral surfactant based on (R,R)‐tartaric acid. (R,R)‐Tartaric acid is acetylated while simultaneously forming a cyclic anhydride, which is then reacted with n‐decylamine forming a chiral, long chain carboxylic acid. This carboxylic acid is then further reacted with the achiral amino acid taurine forming the required surfactant which has a sulfonic acid headgroup. Evidence for its surface activity and an estimate of its critical micelle concentration (cmc) have been obtained using surface tension measurements and conductivity. The surfactant has then been used as the additive in micellar electrokinetic capillary chromatography (MECC) to achieve chiral separations of compounds with multiple aromatic functionality. These separations are compared with those achieved with previously reported tartaric acid based surfactants which show a difference in selectivity. © 1995 John Wiley & Sons, Inc.
A competition assay to detect scrapie prion protein by capillary electrophoresis
Authors: Schmerr Mary Jo , Goodwin Kathryn R. , Cutlip Randall C. , Jenny Allen L.
Published: May 2005

Transmissible spongiform encephalopathies of animals and humans are infectious diseases that cause progressive degenerative disorders of the central nervous system. These diseases are caused by an accumulation in the lysosymes of a modified normal cellular protein. This protein is modified by a post translational modification which truncates a host cellular protein at the N‐terminus causing a conformational change in the protein. After modification, this protein becomes resistant to proteases and aggregates into rod‐shaped fibrils in the brains of infected animals. When these aggregates are subjected to SDS‐PAGE in the presence of 2‐β‐mercaptoethanol, a monomeric form (prion protein) is observed with a molecular mass of ca. 27 kdaltons. Capillary electrophoresis was used to detect immunocomplex formation of the prion protein with an antiserum produced to a peptide of the prion protein. The synthesized peptide was labeled with fluorescein iodoacetamide at the free sulfhydryl group of cysteine that was added to N‐terminus of the peptide. When the fluorescein labeled peptide was incubated with increasing concentrations of the rabbit antibody, a new peak that was proportional to the amount of antiserum in the reaction mixture with a concurrent reduction in the labeled peptide peaks was observed. Incubation overnight at 4°C enhanced immunocomplex formation. Competition of unlabeled peptide and of brain samples prepared from sheep for the fluorescein labeled peptide was carried out using a concentration of rabbit antibody that produced ca. 50% of the maximum amount of immunocomplex formation. Unlabeled peptide and brain samples prepared from scrapie infected sheep brain but not from normal sheep reduced immunocomplex formation. This reduction was dependent on the concentration of the peptide and the amount of scrapie infected brain sample. By using competition for labeled peptide instead of using direct binding of the antiserum to the prion protein as in a previous study, we increased the sensitivity of detection of the scrapie prion protein. © 1995 John Wiley & Sons, Inc.
Extraction of municipal wastewater effluent using 90‐mm C‐18 bonded disks
Authors: Zeng Eddy Y. , Khan Azra R.
Published: May 2005

The effectiveness of solid phase extraction (SPE) using 90‐mm EmporeTM C‐18 bonded disks and liquid‐liquid extraction (LLE) was compared in extraction of municipal wastewater effluent, as well as distilled and sea water. Both SPE and LLE obtained similar recoveries of polycyclic aromatic hydrocarbons and polychlorinated biphenyls from spiked distilled water. Higher recoveries of chlorinated pesticides were achieved from distilled water than from wastewater effluent by SPE. In addition, SPE yielded higher concentrations of PAHs and LABs from effluent samples than did LLE. Apparently, both SPE and LLE were affected by the presence of abundant dissolved organic carbon in wastewater effluent, but LLE suffered more losses. The condensed packing structure in C‐18 disks might allow better extraction of hydrophobic organics from wastewater effluent. Alumina/silica gel clean‐up after SPE was necessary to obtain acceptable quantitation results for wastewater effluent. SPE was technically as effective as LLE and superior to LLE, because it used less organic solvent and manpower. Usage of high density glass beads with C‐18 disks further improved the efficiency of SPE. Lowering the cost of C‐18 disks will make disk SPE more appealing. © 1995 John Wiley & Sons, Inc.
Interactive use of linear retention indices, on polar and apolar columns, with a ms‐library for reliable identification of complex mixtures
Authors: Mondello Luigi , Dugo Paola , Basile Annamaria , Dugo Giovanni , Bartle Keith D.
Published: May 2005

Linear Retention Indices of about 150 compounds present in essential oils have been calculated both on a polar column (Carbowax 20 M) and on an apolar column (SE‐52). A library has been built with the mass spectra and the two Linear Retention Indices. The constituents of bergamot essential oil were used to test the library. Every unknown compound has been investigated using the Linear Retention Indices interactively with the MS spectra. Results obtained with a commercially available library and with our library were compared.
Development of an ion trap / linear time‐of‐flight mass spectrometer with electrospray ionization for micro‐column liquid chromatography detection
Authors: Purves Randy W. , Li Liang
Published: May 2005

A linear time‐of‐flight (TOF) mass spectrometer equipped with a quadrupole ion trap for ion storage was developed for mass analysis of ions generated by electrospray ionization (ESI). With this technique, the continuous ion beam from the ESI source is collimated by a set of focusing lenses into the ion trap where the ions are accumulated for a predetermined period of time. Extraction of the ions into the flight tube of the TOF mass spectrometer is achieved by applying a short duration voltage pulse to the exit endcap of the ion trap. The extraction frequency is variable, but is typically set at 10 Hz. It was shown that with a linear TOF mass spectrometer, mass resolution in the range of 600–950 can be routinely obtained. It was also demonstrated that a complete mass spectrum of bradykinin can be obtained with a direct injection of 75 fmol, or 0.5 μL of 150 nM of sample solution. Buffer gas pressure and the energy of the ions entering the ion trap, were found to be the key parameters in obtaining this sensitivity and resolution. In addition, the ESI ion trap/TOF system was developed and applied for microcolumn liquid chromatography detection of a simple protein mixture. © 1995 John Wiley & Sons, Inc.
Comparison of methods for the analysis of chlorinated phenolics in effluents of pulp‐bleaching operations
Authors: Caramão Elina B. , Furtado João L. F. , Peralba Maria C. R. , Pissolatto Tânia M. , Zini Claudia A.
Published: May 2005

Two methods for analysis of chlorinated organic compounds found in pulp bleaching effluents have been compared in order to determine their efficiencies. Method A uses a solid phase extraction followed by derivatization with acetic anhydride. Method B consists in an in situ derivatization followed by liquid‐liquid extraction of the acetic esters. Both methods have proved to be efficient for analyzing chlorinated organic compounds and, with the exception of 3,4,5‐trichlorosyringol which appeared in a very low concentration when method A was employed, all compounds present in the standard mixture as well as in a pulp bleaching effluent sample have been detected. A detection limit of 0.4 ppb has been established. Quantitative determinations are being carried out and will be presented in a future article. © 1995 John Wiley & Sons, Inc.
Study of the effects of weathering on the chemical composition of a light crude oil using GC/MS GC/FID
Authors: Wang Zhendi , Fingas Merv
Published: May 2005

Quantitative information on the weathering of spilled oil is essential to a fuller understanding of the fate and behavior of oil in the environment. Such data is also useful for spill modeling. The key to acquiring data on oil weathering is the availability of precise and reliable chemical information. Exact quantitation of compounds in the oil can provide this crucial data. In this study, the effects of weathering on the chemical composition of a light crude oil, Alberta Sweet Mix Blend (ASMB), were thoroughly investigated using GC/FID and GC/MS. Complete compositional information on the ASMB oil at various degrees of evaporation (0–45%) was obtained, and the composition and concentration changes of key components and component groupings were quantitatively correlated to evaporative loss. Two opposing effects during evaporation—one is the loss of oil components due to evaporation, and another is build‐up of oil components due to volume deduction—were examined. So‐called “pattern recognition” plots involving more than 100 important individual oil components and component groupings were graphically depicted, and these permitted deduction of a best set of values for quantitation of exposure to evaporative weathering. A “weathering index” concept is proposed. Relatively simple and very useful mathematical equations were derived which can be utilized to describe the weathering behavior of oil and to estimate the evaporation extent of oil. © 1995 John Wiley & Sons, Inc.
The Bereitschaftspotential preceding stepping in patients with isolated gait ignition failure
Authors: Vidailhet M. , Atchison P. R. , Stocchi F. , Thompson P. D. , Rothwell J. C. , Marsden C. D.
Published: May 2005

The cerebral activity preceding voluntary, self‐paced ankle dorsiflexion movements while seated was compared with that before a stepping movement of the same foot while standing in four patients with isolated gait ignition failure. Results within the patient group were variable, but all exhibited some increase in the Bereitschaftspotential (BP) amplitude when stepping as compared with sitting, similar to that seen in normal subjects. This differs from previous results in patients with Parkinson's disease in which stepping was not accompanied by a normal increase in BP amplitude. This difference suggests that the mechanisms responsible for the start hesitation that is common to both Parkinson's disease and gait ignition failure may differ in the two conditions.
The movement disorders of adult opsoclonus
Authors: Caviness John N. , Forsyth Peter A. , Layton Donald D. , McPhee Thomas J.
Published: May 2005

We present three cases of the adult opsoclonus‐myoclonus syndrome in patients with systemic carcinoma. In addition to opsoclonus and myoclonus, other clinical components of the syndrome can include ataxia, tremor, gait and stance dysfunction, altered mental status, and head and face dyskinesias. The most common etiologies are idiopathic, paraneoplastic, and infectious encephalitis. Radiographic and pathological studies suggest brainstem stem dysfunctiion with associated cerebellar and/or cerebellar pathway dysfunction. In many cases, there is evidence for the involvement of immunologic and/or inflammatory processes in the pathogenesis of this syndrome. The timely recognition of this syndrome is important because of its implications for the underlying etiology and prognosis. The appearance of this syndrome should prompt the search for an occult malignancy.
Peripheral and central pharmacokinetics of apomorphine and its effect on dopamine metabolism in humans
Authors: Przedborski Serge , Levivier Marc , Raftopoulos Christian , Naini Ali B. , Hildebrand Jerzy
Published: May 2005

Apomorphine is a dopamine receptor agonist increasingly used in the treatment of Parkinson's disease (PD). In the present study, we examined the plasma and ventricular cerebrospinal fluid (CSF) pharmacokinetics of apomorphine as well as its effects on dopamine metabolism in six patients (one woman and five men, mean age 79.5 years) without evidence of PD who underwent 48‐h intracranial pressure monitoring for suspected normal pressure hydrocephalus. Maximal plasma apomorphine concentration (25.04 ng/ml) is found 20 min after subcutaneous injection (50μg/kg), and the mean area under the curve is 1,439.37 ng/ml for 120 min. In contrast to plasma values, the maximal ventricular CSF apomorphine concentration (1.08 ng/ml) is found 30 min after injection and the mean area under that curve is 7% of that of plasma (96.69 ng/ml for 120 min). Apomorphine administration causes a significant reduction in ventricular CSF concentrations of dopamine and of its major metabolites sulfoconjugated dopamine, 3,4‐dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA). This effect starts 10 min after the injection of apomorphine, is maximal after 30 min (free dopamine, ‐ 30%; sulfoconjugated dopamine, −28%; HVA, −21%; DOPAC, −31%) and is still present, although to a lesser extent ( −5 to −10%), 120 min after the injection of apomorphine. This study shows that in humans a dose of apomorphine commonly used in PD causes significant inhibition of dopamine metabolism lasting >120 min. In addition to their symptomatic effects, dopamine agonists such as apomorphine may play a role in preventing or slowing the neurodegeneration in PD by autoreceptor‐mediated inhibition of dopamine metabolism.
Apomorphine infusional therapy in parkinson's disease: Clinical utility and lack of tolerance
Authors: Gancher Stephen T. , Nutt John G. , Woodward William R.
Published: May 2005

We assessed the clinical utility of apomorphine infusional therapy in patients with parkinsonism and motor fluctuations and sought evidence for alterations in drug response resulting from chronic treatment. Six patients with Parkinson's disease were treated for 3 months with s. c. infusions of apomorphine administered during waking hours. At the beginning and the end of the study, test doses of apomorphine (12.5–100 μg/kg) were administered to establish a dose‐response curve. Over the study, the patients reported a significant improvement in the number of “on” hours experienced per day and substantially reduced the dose and frequency of levodopa and other antiparkinsonian medications. No average change in apomorphine dose‐response relationships or pharmacokinetics was observed during the study. However, two patients lowered the infusion rate during the 3‐month observation and exhibited higher drug levels and longer responses following test doses of apomorphine given at the end of the study. Although pragmatic concerns with the use of infusion pumps solutions and adverse effects limited the overall benefit afforded by the treatment, this kind of drug treatment may be useful in selected patients with severe parkinsonism and fluctuations.
Soleus H‐reflex tests in dystonia
Authors: Koelman J. H. T. M. , Willemse R. B. , Bour L. J. , Hilgevoord A. A. J. , Speelman J. D. , de Visse B. W. Ongerboer
Published: May 2005

Vibratory inhibition, the homonymous recovery curve and the ratio of the maximal H‐reflex to direct muscle potential (H/M ratio) of the soleus H‐reflex were assessed in 10 patients with leg dystonia and in six patients with arm or neck dystonia. The results were compared with those obtained in 48 healthy control subjects. H‐reflex variables most helpful for the discrimination of patients and healthy subjects were identified. In patients with leg dystonia, vibratory inhibition was less marked than in control subjects, whereas late facilitation of the recovery curve was increased. In patients with leg dystonia, area values of test reflexes in the late facilitatory phase of the recovery curve exceeded peak‐peak values, in contrast to findings in control subjects. This finding may be attributable to less synchronization of enhanced test reflexes in dystonia than in the control condition. In differentiating patients with leg dystonia from control subjects, a combination of parameters of vibratory inhibition and the late facilitatory phase of the recovery curve appeared most useful. In patients with arm or neck dystonia and in the unaffected legs of hemidystonic patients, soleus H‐reflex test results were in the normal range. Abnormalities in the results of the soleus H‐reflex tests we used appear to be related to the presence of clinical signs in the extremity under examination and not to the severity of features.
Morphological overlap between corticobasal degeneration and Pick's disease: A clinicopathological report
Authors: Jendroska Klaus , Rossor Martin N. , Mathias Christopher J. , Daniel Susan E.
Published: May 2005

An 81‐year‐old woman died after a 3‐year history of a progressive nondementing akinetic‐rigid syndrome. Initially, there was a moderate response to levodopa treatment. Subsequently she developed postural tremor, loss of upward gaze, and frequent falls suggestive of Steele‐Richardson‐Olszewski syndrome (SROS). Macroscopical examination showed depigmentation of substantia nigra and locus ceruleus. Histology revealed occasional swollen achromatic neurons predominantly in frontal cortex, small cortical neurofibrillary tangles, brain stem basophil (corticobasal) inclusions, and Pick bodies. The coexistence of these histopathological markers raises questions concerning their specificity and the basis of a morphological distinction between corticobasal degeneration and Pick's disease.
Planning and execution of pointing movements in cerebellar patients
Authors: Bonnefoi‐Kyriacou Bernadette , Trouche Elisabeth , Legallet Eric , Viallet François
Published: May 2005

Twelve patients with cerebellar dysfunction including a limb ataxia and 12 age‐matched controls performed pointing movements with an arm. In one condition, the task was a simple reaction time (RT) movement directed toward a spatially defined target. The other two conditions involved choice tasks in which the amplitude and direction of movement were varied. The variables recorded were: movement latency determined by measuring the RT, duration of movement and the terminal accuracy of pointing as reflected in the movement time (MT), pointing surfaces (PS), and systematic errors. RTs and MTs were found to be significantly longer in cerebellar patients than in controls. In both groups the choice RT increased significantly as compared to simple RT, but no significant difference between patients and controls was found for the mean increase of the choice RT as compared with the mean increase for simple RT. A strong correlation between MTs and PSs was found in the controls. The cerebellar patients showed no correlation between MTs and PSs. The results are discussed in relation to the ability in cerebellar patients to program and execute voluntary movements.
Intrathecal immune activation in three patients with progressive myoclonic ataxia
Authors: Salmaggi A. , Carella F. , Ciano C. , Binelli S. , Giovannini P. , Palazzini E. , Girotti F.
Published: May 2005

Three patients displaying a clinical picture of progressively evolving multifocal action myoclonus and cerebellar ataxia showed a marked intrathecal immune activation, which was persistent over a 2‐ to 5‐year time span in the two serially investigated patients. A thorough search for metabolic, toxic, infectious, or degenerative causes of myoclonus was unsuccessful. The presence of intrathecal immune activation in at least a subgroup of patients with the clinical features of progressive myoclonic ataxia suggests the possibility of immune‐mediated damage within the central nervous system in this condition.
Functional decline in Huntington's disease
Authors: Feigin Andrew , Kieburtz Karl , Bordwell Kathy , Como Peter , Steinberg Kimberly , Sotack Jenny , Zimmerman Carol , Hickey Charlyne , Orme Constance , Shoulson Ira
Published: May 2005

We prospectively evaluated 129 patients with manifest Huntington's disease (HD) to determine the rate of illness progression and the clinical features that correlate with functional decline. A single examiner evaluated each patient using the HD Functional Capacity Scale. Standardized motor performance was also assessed in 94 of the patients (73%) using the HD Rating Scale. Total Functional Capacity declined at a rate of 0.63 ± 0.75 U per year. As functional capacity worsened, chorea lessened, and dystonia intensified. There was no correlation between rate of functional decline and age at onset of HD, body weight, gender of affected parent, or history of neuroleptic use.
Measurement of rigidity in Parkinson's disease
Authors: Prochazka Arthur , Bennett David J. , Stephens Marilee J. , Patrick Susan K. , Sears‐Duru Rosemary , Roberts Ted , Jhamandas Jack H.
Published: May 2005

Clinical assessment of rigidity in parkinsonian patients is largely qualitative. The reliability and validity of the assessments are sometimes in doubt. Several “engineering” methods of quantifying rigidity have been described, but none has been adopted into general clinical practice. A possible reason is that these methods differ in crucial aspects from the clinical exam. We therefore tackled the problem by monitoring the clinical exam itself, using small sensors to measure the forces and displacements applied. Limb impedance(Z) was computed using parameter identification methods and compared to raters' verbalized ratings of rigidity based on a 5‐point scale: the Unified Parkinson's Disease Rating System. The qualitative and quantitative estimates of impedance covaried over a fourfold range, depending on the forces imposed and the subject's motor set. Raters differed by up to 1 full point in their mean qualitative ratings and sometimes disagreed on whether levodopa reduced rigidity. This was not due to any significant differences in the overall range of rigidity they evoked, but rather to the way they scored this range [the ratio of mean rating to mean impedance (R/Z) varied between raters and subjects]. On the other hand, the R/Z ratio was reproducible over separate sets of ratings and may therefore serve to convert measured impedance into a standardized rating. Our results indicate that the current clinical exam may be too abbreviated to detect the sometimes quite small reductions in rigidity after levodopa. We conclude that a device that conveniently quantifies the clinical assessment of rigidity is now available and will lead to more standardized protocols for rating rigidity in the near future.
Long‐term changes of striatal dopamine D2 Receptors in patients with Parkinson's disease: A study with positron emission tomography and [11C]Raclopride
Authors: Antonini Angelo , Schwarz Johannes , Oertel Wolfgang H. , Pogarell Oliver , Leenders Klaus L.
Published: May 2005

We used [11C]raclopride (RACLO) and positron emission tomography (PET) to study longitudinally striatal dopamine D2 receptor binding in nine patients with Parkinson's disease (PD) at an early drug‐naive stage and 3–5 years later, when motor fluctuations had appeared in seven of them. Patients were treated with a combination of levodopa and dopamine agonists. Data were compared with 10 healthy controls in the same age range. Initially, patients with PD showed a significant increase of RACLO uptake in the putamen compared with controls (p < 0.04). The caudate nucleus revealed values in the normal range. After 3–5 years, RACLO binding was significantly reduced in the putamen (p < 0.03) and caudate nucleus (p < 0.03) compared with baseline. Values were now in the control range in the putamen and reduced in the caudate nucleus (p < 0.05). The clinical score at “off” had significantly worsened (p < 0.0005) compared with the first PET scan. The nine PD patients reported here had already been investigated 3–4 months after therapy began and at that time did not show a reduction of the initially increased RACLO binding capacity (data published previously). These results indicate long‐term downregulation of striatal dopamine D2 receptor binding in PD. Receptor changes in the striatum of patients with PD may be induced by chronic dopaminergic therapy or occur independently of treatment, as a result of structural adaptation of the postsynaptic dopaminergic system to the progressive decline of nigrostriatal neurons.
The neurological syndrome of infantile cobalamin deficiency: Developmental regression and involuntary movements
Authors: Grattan‐Smith P. J. , Wilcken B. , Procopis P. G. , Wise G. A.
Published: May 2005

Developmental regression is the presenting symptom of most infants with cobalamin (vitamin B12) deficiency. We present a report of three infants with cobalamin deficiency in which the infants also developed a movement disorder. In each case the mother was a vegetarian and the infant was exclusively breast‐fed. In two of the infants, a striking movement disorder consisting of a combination of tremor and myoclonus particularly involving face, tongue, and pharynx appeared 48 h after the initiation of treatment with intramuscular cobalamin. This was associated with marked changes in plasma amino acid levels. Paradoxically, the onset of the movement disorder coincided with overall neurological improvement. The third infant had a persistent focal tremor, which appeared before the commencement of treatment. The movements slowly abated during a 3–6‐week period. The presence of a movement disorder in cobalamin deficiency has received less attention than other features, but in a mild form is probably common. It may offer an early clue to the diagnosis before the onset of profound neurological deterioration. The cause of the severe movement disorder that can appear after treatment is not known.
Clinical, polysomnographic, and genetic characteristics of restless legs syndrome: A study of 133 patients diagnosed with new standard criteria
Authors: Montplaisir Jacques , Boucher Sylvie , Poirier Gaétan , Lavigne Gilles , Lapierre Odile , Lespérance Paul
Published: May 2005

One hundred thirty‐three cases of restless legs syndrome (RLS), diagnosed with criteria recently formulated by an international study group, were studied by questionnaire and with all‐night polysomnographic recordings. Results show that RLS starts at a mean age of 27.2 years and before age 20 in 38.3% of patients. Symptoms often appear in one leg only and also involve upper limbs in about half of all cases. Most patients (94%) report sleep‐onset insomnia or numerous nocturnal awakenings due to RLS symptoms. A strong relationship was found between these complaints and polysomnographic findings; increasing sleep latency and number of awakenings and decreasing sleep efficiency were associated with worsening symptoms. Periodic leg movements in sleep (index > 5 movements/h sleep) were found in 80.2% of patients. This study shows that this percentage is increased when 2 recording nights are considered (most severe score). Eighty patients of 127 (63%) reported the presence of RLS in at least one of their first‐degree relatives. In these families, 221 of 568 first‐degree relatives (39%) were reported by the patients to be affected with RLS.
The effect of the catecholamine precursor L‐Dopa on sleep bruxism: A controlled clinical trial
Authors: Lobbezoo F. , Lavigne G. J. , Tanguay R. , Montplaisir J. Y.
Published: May 2005

The putative role of the dopaminergic system in sleep bruxism (SB) was studied in a double‐blind clinical trial by using low doses of short‐term L‐dopa in combination with benserazide. We recorded 10 patients with SB in our sleep laboratory for 3 consecutive nights. The first night was for habituation to the laboratory environment. During the second and the third nights, the patients received two doses of either L‐dopa or a placebo in a crossover fashion: the first dose 1 h before bedtime and the second, 4 h after the first one. The order of administration was reversed in half the patients. The efficacy of L‐dopa was analyzed by using multilevel models. L‐Dopa resulted in a significant decrease in the average number of bruxism episodes per hour of sleep, as well as in a significant reduction in the average value of the root‐mean‐square (RMS) electromyography (EMG) level per bruxism burst. This indicates that L‐dopa exerts an attenuating effect on SB. In addition, L‐dopa caused a reduction in the variance in RMS values, which suggests that L‐dopa normalizes the EMG activity patterns associated with SB.
The EDB Test—A clinical test for the detection of antibodies to botulinum toxin type A
Authors: Kessler Kirn R. , Benecke Reiner
Published: May 2005

Approximately 5 to 10% of patients with cervical, segmental or multifocal dystonia receiving repetitive local injections with botulinum toxin A (BTX A) are estimated to develop secondary loss of treatment benefit (nonresponding) because of the formation of circulating serum antibodies against the neurotoxin. Because other reasons may account for loss of benefit during the course of treatment, the group of secondary nonresponders because of antibody formation need to be separated from the antibody‐negative group by appropriate testing. We present an easy clinical antibody test based on a test injection of BTX A into an indicator muscle, the extensor digitorum brevis (EDB), combined with amplitude measurements of compound muscle action potentials (CMAPs) elicited by electrical nerve stimulation of the peroneal nerve before and after the injection. The results show that in a group of clinically defined secondary nonresponders, who were serologically proven to be antibody negative, a marked decrease in CMAP amplitude can consistently be detected in the injected EDB 4 weeks after BTX A injection. In contrast, antibody‐positive patients are characterized by a lack of such decrease in amplitude. In all cases, results of the EDB test were in keeping with the standard mouse bioassay test. We conclude that the EDB test is a useful tool for clinicians faced with the question of whether a secondary nonresponding patient has in fact developed antibodies to BTX A.
Short‐term levodopa test assessed by movement time accurately predicts dopaminergic responsiveness in Parkinson's disease
Authors: Zappia Mario , Montesanti Rita , Colao Rosanna , Branca Damiano , Nicoletti Giuseppe , Aguglia Umberto , Quattrone Aldo
Published: May 2005

Short‐term challenges with dopaminergic agents are used in patients with idiopathic Parkinson's disease (IPD) to predict the therapeutic effect of sustained levodopa treatment, but false‐negative results often occur. We prospectively evaluated 74 patients with clinically diagnosed IPD and compared the predictive value of a short‐term levodopa test assessed by movement time (MT) with the predictive value obtained by the evaluation with the motor examination part of the Unified Parkinson's Disease Rating Scale (UPDRS‐ME). The response to long‐term levodopa was accurately predicted in 96% of patients by assessing the response to the short‐term test with MT and in 80% of cases with UPDRS‐ME. Similar predictive values were obtained by separately analyzing 21 de novo patients. The short‐term test also accurately predicted the magnitude of improvement with long‐term treatment. We conclude that the predictive value for long‐term dopaminergic responsiveness may be further enhanced by evaluating the short‐term pharmacologic challenges with MT analysis. This is particularly useful to select de novo patients for drug trials with dopaminergic agents.
Ophthalmoplegia and leg myorhythmia in Whipple's disease: Report of a case
Authors: Rajput A. H. , McHattie J. D.
Published: May 2005

Whipple's disease (WD) is a rare disorder that is more common in males than females. Progressive supranuclear ophthalmoplegia (SNO) in conjunction with oculomasticatory myorhythmia (OMM) or oculofacioskeletal myorhythmia are characteristic movement abnormalities when WD involves the nervous system. Limb myorhythmia without facial or ocular myorhythmia has not been reported in WD. We report such a case who had SNO and leg myorhythmia but no facial or ocular myorhythmia. She had onset of WD at age 28 and 16 years later developed SNO and leg myorhythmia. The neurological manifestations did not respond to antimicrobial agents or to the drugs used for parkinsonism or essential tremor. Valproate produced a remarkable improvement in leg myorhythmia, but the efficacy declined after 3 months. Because WD may manifest as a neurological disorder without gastrointestinal symptoms, all SNO cases, with or without OMM, and those with skeletal myorhythmia should be suspected of WD. These patients should be treated vigorously and followed carefully since neurological involvement is the most disabling feature and it has a propensity to relapse.
Cerebellar presentation of multiple system atrophy
Authors: Wenning G. K. , Kraft E. , Beck R. , Fowler C. J. , Mathias C. J. , Quinn N. P. , Harding A. E.
Published: May 2005

Early diagnosis of multiple‐system atrophy (MSA) is important in patients presenting with late‐onset cerebellar ataxia because it has a less favourable prognosis than other degenerative ataxic disorders. We report cerebellar presentation of MSA in a series of 16 patients, 3 of whom later developed parkinsonism. Two‐thirds of them had early evidence of impaired postural reflexes with a history of recurrent falls. Some of these had a narrow‐based, unsteady gait, unlike the more classic broad‐based gait ataxia of cerebellar disease. On review of the patients' histories, genitourinary dysfunction (particularly impotence) was present at the onset of, or preceding, cerebellar ataxia in 60% of patients, but this had often been attributed to age, or to urological or gynaecological causes. External striated anal or urethral sphincter electromyography (EMG) demonstrated features of chronic denervation and reinnervation in 14 (93%) of 15 patients, consistent with degeneration in Onuf's nucleus as occurs in MSA. Autonomic function tests were abnormal in 9 (64%) of 14 patients. Our data suggest that close enquiry into genitourinary function and analysis of the gait disorder can be useful pointers to a diagnosis of MSA in patients with an unexplained adult‐onset progressive cerebellar syndrome, and that sphincter EMG is the most useful investigation in this context.
Multiple system atrophy: A review of 203 pathologically proven cases
Authors: Wenning G. K. , Tison F. , ben Shlomo Y. , Daniel S. E. , Quinn N. P.
Published: May 2005

We report the clinicopathological features of 203 cases of pathologically proven multiple system atrophy (MSA) from 108 publications up to February 1995. The majority of patients showed symptoms in their early fifties, and men were more commonly affected than women (ratio of 1.3:1). Most patients suffered from some degree of autonomic failure (74%). Parkinsonism was the most common motor disorder (87%), followed by cerebellar ataxia (54%) and pyramidal signs (49%). The response to levodopa was poor in most patients, but there was a subgroup with a good response, who also often developed axial levodopa‐induced dyskinesias. Other characteristic features included severe dysarthria, stridor, and, in a few patients, contractures and dystonia (antecollis). Mild or moderate intellectual impairment occurred in some cases, but severe dementing illness was most unusual. The main pathological change comprised cell loss and gliosis in the putamen, caudate nucleus, external pallidum, substantia nigra, locus ceruleus, inferior olives, pontine nuclei, cerebellar Purkinje cells, and intermediolateral cell columns of the spinal cord. However, other neuronal populations were also involved to varying degrees, such as the thalamus, vestibular nucleus, dorsal vagal nucleus, corticospinal tracts, and anterior horn cells. Characteristic glial and/or neuronal cytoplasmic inclusions were identified in all cases in which they were sought, irrespective of clinical presentation. Akinesia correlated with the degree of nigral and putaminal cell loss, whereas rigidity was related only to the latter. Tremor was unrelated to cell loss at any site. Ataxia correlated with the degree of olivopontocerebellar atrophy. Pyramidal signs were associated with pyramidal tract pallor. Our analysis also confirmed an association of postural hypotension with intermediolateral cell column degeneration.
Mechanism of action of clozapine‐induced modification of motor behavior in an animal model of the “super‐off” phenomenon
Authors: Dziewczapolski G. , Menalled L. B. , Savino M. T. , Mora M. , Stefano F. J. E. , Gershanik O.
Published: May 2005

We tested the effects of clozapine, an “atypical” neuroleptic with high affinity for the D4 (dopaminergic), and the 5‐HT1c and 5‐HT2 (serotonergic) receptor subtypes on locomotor activity in an animal model of Parkinson's disease showing a bimodal response curve to increasing doses of a D2 agonist. Sulpiride (D2 antagonist) and ritanserin (5‐HT1c and 5‐HT2 antagonist) were used for comparison. The D1 agonist SKF 38393 at a dose of 8 mg/kg significantly reversed the akinesia induced by chronic reserpine treatment (1 mg/kg for 5 days) and alpha‐methyl‐p‐tyrosine pretreatment (300 mg/kg). In this model, the addition of a low dose of a D2 agonist, LY 171555 (quinpirole, 1 μg/kg), inhibited the effects of SKF 38393, whereas the same drug at higher doses (5–50 μg/kg) restored and potentiated the stimulatory response to D1 stimulation. Clozapine inhibited the inhibitory phase and potentiated the stimulatory phase of the curve. Sulpiride inhibited both phases of the dose‐response curve (inhibitory/stimulatory), whereas ritanserin had no effect. We believe these results may reflect a disinhibition phenomenon possibly mediated by the blockade by clozapine of a subpopulation of inhibitory dopa‐mine (DA) receptors belonging to the D2 “family”.
Step initiation in Parkinson's disease: Influence of levodopa and external sensory triggers
Authors: Burleigh‐Jacobs Anne , Horak Fay B. , Nutt John G. , Obeso Jose A.
Published: May 2005

We studied anticipatory postural adjustments contributing to gait initiation deficits in patients with Parkinson's disease (PD) to determine if these deficits could be improved by administration of levodopa or by external stimuli. Ground reaction forces and body kinematics were recorded for self‐generated and cutaneous cue‐triggered step initiation in normal subjects and in PD subjects when OFF and when ON. The effects of assisting anticipatory postural sway with a surface translation coupled with a cutaneous cue were also examined. Decreased force production, decreased velocity of movement, and slowed execution of the anticipatory postural adjustments for self‐generated step characterized step initiation in PD subjects when OFF. These impairments were significantly less evident when the PD subjects were ON. Both PD and normal subjects increased force and velocity of movement when a cutaneous cue was used as a go signal. When subjects voluntarily initiated a step in response to the surface translation, both PD and normal subjects executed the anticipatory postural adjustments for step more rapidly, but the PD subjects, both ON and OFF, failed to increase force to execute push‐off more rapidly. In conclusion, dopaminergic therapy and an external stimulus similarly improve the deficient force production for the anticipatory postural adjustments associated with step initiation in PD. The findings also suggest that force production during the postural adjustment phase of self‐generated, but not externally triggered, step initiation is influenced by dopaminergic pathways.
A dose‐ranging study of selegiline in patients with Parkinson's disease: Effect on platelet monoamine oxidase activity
Authors: Andreu Nathalie , Damase‐Michel Christine , Senard Jean‐Michel , Rascol Olivier , Montastruc Jean‐Louis
Published: May 2005

A dose‐ranging study of selegiline was performed in patients with Parkinson's disease to determine the minimal dosage of the drug able to inhibit ≥95% of platelet monoamine oxidase (MAO) activity. Different doses of selegiline (5 or 10 mg daily, 10 or 20 mg weekly) were studied in four groups of six patients with Parkinson's disease. Platelet MAO activity was measured before and after 1 month's treatment with selegiline. The doses of 5 or 10 mg daily and 20 mg (i.e., 10 mg × 2) weekly induced a complete inhibition of platelet MAO‐B activity from day 7 to day 28 (96.0–99.5%). In contrast, platelet MAO‐B inhibition was only 75.9% of the basal value after a dosage of 10 mg weekly. These results demonstrate that 20 mg weekly is the minimal dosage of selegiline able to induce a maximal and long‐lasting inhibition of platelet MAO‐B activity in patients with parkinsonism. Further clinical trials are needed to investigate the clinical efficacy of this dose.
Unchanged basal ganglia N‐acetylaspartate and glutamate in idiopathic Parkinson's disease measured by proton magnetic resonance spectroscopy
Authors: Clarke C. E. , Lowry M. , Horsman A.
Published: May 2005

The lentiform nucleus of five patients with idiopathic Parkinson's disease (IPD) was studied by quantitative magnetic resonance spectroscopy (MRS), both before and after administration of apomorphine, and the spectra were compared with those from a group of age‐matched normal subjects. The concentrations of the three major metabolites, choline, creatine, and N‐acetylaspartate (NAA), were quantified using tissue water content as an internal concentration reference. Glutamate concentration was assessed as the (glutamate + glutamine; GLX)/creatine peak area ratio. In normal subjects, the mean ± SD concentrations of the three metabolites were 2.4 ± 0.4 μmol/g wet wt for choline 11.5 ± 0.8 μmol/g for creatine, and 14.7 ± 2.8 μmol/g for NAA. The Glx/creatine ratio was 1.26 ± 0.12. There was n significant difference in these parameters in the lentiform nucleus of patients with IPD either before or after apomorphine. The absence of detectable differences in IPD in this study implies that the changes in glutamate metabolism in the basal ganglia predicted by animal work are more subtle than those currently observable by MRS.
Sensory and motor evoked potentials in multiple system atrophy: A comparative study with Parkinson's disease
Authors: Abbruzzese Giovanni , Marchese Roberta , Trompetto Carlo
Published: May 2005

Somatosensory evoked potentials (SEPs) to median nerve stimulation and motor evoked potentials to transcranial magnetic stimulation (TMS) of the motor cortex were studied in 15 patients with multiple system atrophy (MSA) and compared with matched groups of 20 patients with idiopathic Parkinson's disease (PD) and of 20 normal controls (NCs). No SEP latency or amplitude abnormalities were observed, and, in particular, the frontal N30 component was not significantly depressed. No differences in TMS threshold for evoking responses in relaxed or active thenar muscles were observed. The mean central motor conduction time was normal for the biceps brachii and opponens pollicis muscles and prolonged in the MSA group for the tibilais anterior muscle. Recording SEPs is not useful to differentiate MSA from PD, while the presence of central motor conduction abnormalities may bring into question the diagnosis of idiopathic PD.