bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThis 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

AbstractTransmissible 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

AbstractThe 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

AbstractLinear 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

AbstractA 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

AbstractTwo 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

AbstractQuantitative 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

AbstractThe 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

AbstractWe 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

AbstractApomorphine 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

AbstractWe 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

AbstractVibratory 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

AbstractAn 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

AbstractTwelve 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

AbstractThree 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

AbstractWe 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

AbstractClinical 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.