bluuebunny/crossref_metadata_2025 huggingface dataset:
Is levodopa toxic to human substantia nigra?
Authors: Rajput A. H. , Fenton M. E. , Birdi S. , Macaulay R.
Published: May 2005

Levodopa (LD) is the most effective drug for symptomatic control of Parkinson's disease, but has been suspected to be toxic to substantia nigra (SN) dopaminergic neurons. Tissue culture and animal studies of LD toxicity have produced contradictory evidence, and one study reported that a human subject exposed to a large cumulative dose (ed) of LD over 4 years had no evidence of SN damage. We reprot the cases of five patients, each of whom received a large cd of LD over a long period. Fluorodopa positron‐emission tomography performed in one case indicated parkinsonism. Autopsies in two cases indicated a normal SN in one and a hypopigmented SN with normal cell complement in the other. Three patients had essential tremor, one had nonprogressive parkinsonism, and one had dopa‐responsive dystonia. LD (without decarboxylase inhibitor) was administered over 21 years (cd = 21.99 kg), 9 years (cd = 6.6 kg), 26 years (cd = 18.7 kg), 11 years (cd = 3 kg), and 26 years (cd = 23.93 kg), respectively. None of the patients with essential tremor developed clinical features of parkinsonism that indicated significant SN damage, and one had a normal SN at autopsy. The parkinsonian patient displayed no detectable acceleration of disease process, and the patient with dopa‐responsive dystonia had a normal complement of SN neurons at autopsy. We conclude that LD, administered at a dose commonly used for treating Parkinson's disease, was not toxic to SN neurons in these cases.
Decreased habituation of midlatency auditory evoked responses in parkinson's disease
Authors: Teo Charles , Rasco Lisa , Al‐Mefty Kynda , Skinner Robert D. , Boop Frederick A. , Garcia‐Rill Edgar
Published: May 2005

The PI midlatency auditory evoked potential was studied in patients with Parkinson's disease and compared to that in age‐matched controls. Habituation of the potential was determined by using a two‐click stimulus paradigm in which the stimuli were presented at 250‐, 500‐, and 1,000‐ms inter‐stimulus intervals. Results showed that habituation of the PI potential had a statistically significant decrease at the 250‐ms and 500‐ms interstimulus intervals in patients with Parkinson's disease compared to normal controls. The degree of decreased habituation was found to increase with severity of the disease such that stage 5 patients showed greater decreases in habituation compared to stage 4, as did stage 4 compared to stage 3. These findings may be explained by the presence of a dysregulation of sensory processing, possibly by elements of the reticular activating system, including the pedunculopontine nucleus, in Parkinson's disease.
Control of repetitive lip and finger movements in parkinson's disease: Influence of external timing signals and simultaneous execution on motor performance
Authors: Konczak Jürgen , Ackermann Hermann , Hertrich Ingo , Spieker Sybille , Dichgans Johannes
Published: May 2005

This study addresses the question of whether external timing signals and/or simultaneous rhythmic movements of other limbs can alleviate sequencing motor deficits associated with Parkinson's disease (PD). Subjects performed rhythmic lip and finger movements simultaneously or in isolation. In addition, they had to self‐pace their movements or match them to an external signal. Our results are summarized as follows: (a) Seven of 12 patients had adequate mean repetition rates; that is, they fulfilled the task requirements on a global scale. The remaining five patients had various degrees of hastened responses and were not fully able to synchronize their movements to an external pacing signal. (b) PD patients exhibited hypometria in their finger tapping, but not in their lip movements. Their movements were not abnormally slowed, but peakvelocity was appropriately scaled, even to reduced movement amplitudes. (c) Mean repetition rates, stability of frequency response, and kinematics did not differ between conditions of external and internal stimulation within the PD group, but were different from the control group performance. (d) Kinematic measures were not improved during dual‐task execution. PD patients were not able to maintain a 1:1 rhythm between effectors. The incidence of hastening increased during simultaneous motor execution. We conclude that the use of external pacing signals might aid movement initiation of PD patients, but does not improve their temporal or spatial coordination when generating repetitive movements. Simultaneous execution does not necessarily enhance motor performance, but might actually have detrimental effects in patients prone to hastening.
Inhibition of voluntary activity by thalamic stimulation in humans: Relevance for the control of tremor
Authors: Strafella Antonio , Ashby Peter , Munz Michael , Dostrovsky John O. , Lozano Andres M. , Lang Anthony E.
Published: May 2005

The motor effects of stimuli delivered through four‐channel, quadripolar macroelectrodes chronically implanted in the ventrolateral thalamus were studied in 20 awake cooperating human subjects. Single stimuli could inhibit voluntary contraction of the contralateral first dorsal interosseous muscle (FDI) for up to 200 ms. The inhibition was often followed by a rebound facilitation or by oscillatory activity. This inhibition appeared to arise from the ventrolateral thalamus and could not be obtained in other patients by stimulation of the periventricular grey matter (PVG), the globus pallidus internus (GPI), or the subthalamic nucleus (STN). The neural elements activated by the stimulus had a short chronaxie and a short refractory period, implying that they were large‐diameter axons. Similar effects were obtained from each of the four electrodes in the row, suggesting that this fiber system lay parallel rather than perpendicular to the implanted macroelectrode. The inhibition resulting from a single stimulus was diminished by a prior stimulus or train of stimuli. A continuous train of stimuli produced inhibition for only the first 200 ms. We propose that the thalamic stimulus activates a neural network which includes thalamic relay cells and neurons of the thalamic reticular nucleus and that the inhibition of thalamic relay cells habituates with repeated stimuli. It has been suggested that parkinsonian rest tremor results from synchronization of the oscillatory activity of this network. If this is the case, continuous thalamic stimulation might disrupt this oscillation by diminishing the inhibitory phase.
Sertraline for the treatment of depression in parkinson's disease
Authors: Hauser Robert A. , Zesiewicz Theresa A.
Published: May 2005

Although antidepressant medications are commonly used to treat depression in Parkinson's disease (PD), little information is available regarding their safety and efficacy in this condition. Sertraline is a relatively selective serotonin reuptake inhibitor with some dopamine reuptake inhibitor activity. It has a favorable tolerability profile, especially in the elderly. We undertook an open‐label pilot evaluation of the safety and efficacy of sertraline to treat depression in PD. A total of 15 patients with PD and depression participated in the study. Sertraline was introduced at a daily dose of 25 mg for 1 week and then increased to 50 mg/day. Patients underwent evaluation at baseline and at a final visit ˜7 weeks later. Sertraline was generally well tolerated, but five patients experienced side effects, and two discontinued medication. Patients taking selegiline experienced more adverse effects. Beck Depression Inventory scores improved significantly (mean plusmn; SE = 16.0 plusmn; 2.0 vs 11.7 plusmn; 1.9, p = 0.03), and Unified Parkinson's Disease Rating Scale and energy‐level scores were unchanged. These results suggest that sertraline may be a useful treatment for depression in PD. As substantial placebo effects can occur in studies of PD and depression, placebo‐controlled, double‐blind studies are warranted.
Action palatal tremor in a patient with primary intestinal lymphoma
Authors: Gambardella Antonio , Zappia Mario , Valentino Paola , Aguglia Umberto , Fera Francesco , Pardatscher Kurt , Quattrone Aldo
Published: May 2005

We report the case of a 59‐year‐old man with primary intestinal T‐cell non‐Hodgkin's lymphoma who developed abnormal facial twitching synchronous with small palatal movements induced by attempts at speaking or swallowing. At rest, the electromyogram (EMG) showed no spontaneous muscular activity. Phonation triggered trains of synchronous, rhythmic EMG bursts at a frequency of 3–4 Hz lasting 10–20 s, with an average burst of 150 ms, which simultaneously involved palatal, facial, and neck muscles bilaterally with left‐sided predominance. An enhanced blink reflex recovery curve was observed after stimulation of either side. Backaveraging electroencephalographic study revealed no activity that was time locked with the jerks. Axial T2‐weighted magnetic resonance imaging showed an increased signal intensity and bilateral enlargement of the inferior olives. No antineuronal‐specific antibodies were found in the blood or in the cerebrospinal fluid. All of these clinical findings were consistent with a symptomatic palatal tremor (PT). Because it was triggered by activation of cranial muscles, we termed this movement disorder action PT. To our knowledge, this is the first report of symptomatic PT displaying these features.
Validity of long‐term electromyography in the quantification of tremor
Authors: Spieker Sybille , Ströle Verena , Sailer Alexandra , Boose Anders , Dichgans Johannes
Published: May 2005

We previously developed a method of tremor quantification using long‐term electromyography registration of antagonistic forearm muscles that is reliable, sensitive, and specific for pathologic tremors. The present study demonstrates that tremor occurrence as measured by this method correlates well with clinical parameters of tremor in idiopathic Parkinson's disease (PD) and essential tremor (ET) (subscores of the Unified Parkinson's Disease Rating Scale for PD, tremor rating according to Bain et al. ET). We conclude that the method is a valid and objective means of tremor quantification in PD and ET.
Idiosyncratic adverse reactions to intramuscular botulinum toxin type a injection
Authors: Lewitt Peter A. , Trosch Richard M.
Published: May 2005

Three cases of adverse reactions to repeated intramuscular botulinum toxin A (BTA) injections are described: a persistent rash on the face at the site of injection, a localized anaphylactic reaction following BTA injection into one leg, and bilateral ptosis repeatedly following BTA injection into neck muscles. The mechanisms for these idiosyncratic adverse responses are not known.
Pregnancy in Parkinson's disease: A review of the literature and a case report
Authors: Hagell Peter , Odin Per , Vinge Ellen
Published: May 2005

Pregnancy is rare in Parkinson's disease (PD). In the literature on studies of antiparkinsonian drugs in animals during pregnancy, there are reports on malformations of the skeletal and circulatory system. However, the majority of studies in animals have not shown any teratogenicity. Amantadine has been teratogenic in rats and selegiline has caused neurochemical and behavioral alterations in rats when coadministered with clorgyline. The published experience with humans consists of 35 pregnancies among 26 women suffering from PD, including this report, and a number of cases treated with antiparkinsonian agents for other reasons. With the exception of the majority of the cases where amantadine was used, complications have been rare. However, there are indications that suggest a possible risk of a woman's parkinsonism worsening in connection with pregnancy. We also report the case of a woman with PD who was treated with L‐dopa‐benserazide during an uncomplicated pregnancy and gave birth to a healthy boy without experiencing any worsening of her PD.
Variability of the immunologic and clinical response in dystonic patients immunoresistant to botulinum toxin injections
Authors: Sankhla Charulata , Jankovic Joseph , Duane Drake
Published: May 2005

Immunoresistance (Ab+) to botulinum toxin type A (BTX‐A) has been a serous concern since the introduction of BTX‐A in the treatment of dystonia and other disorders associated with abnormal muscle contractions. We studied seven patients who developed Ab+ and later reverted to antibodynegative (Ab‐) status. These seven patients, six women (mean age, 56 years; range, 41–80 years), with an average duration of dystonia for all patients of 197 months (range, 84–360 months), received a total mean cumulative dose of 1659 units (U) (range,810‐1975 U), with an average dose of 207 U per visit. All of these patients became unresponsive to BTX‐A treatment and became Ab+ as determined by mouse bioassay. Their response to BTX‐A after they revertedd to Ab‐ was analyzed. The average latency between the initial BTX‐A treatment and development of Ab+ was 27 months (range, 15–43 months). The average duration between the detection of Ab+ status and subsequent reversal to Ab‐ status was 30 months (range, 10–78 months). Six of these Ab‐ patients were reinjected with BTX‐A, and all six benefited from repeat injections comparable with their earlier response. Three patients lost their clinical response to subsequent injections and were found to be again Ab+. Two of the five patients who became immunoresistant to BTX‐A received botulinum toxin type F (BTX‐F) injections and one patient received a single session of BTX‐B with improvement in their symptoms. In conclusion, this unique group of patients who were Ab+ and became Ab‐ responded favorably to repeat BTX‐A injections, but some lost the benefit with subsequent injections. These observations suggest that the anamnestic immunologic response to BTX‐A can wane, but can be reactivated by repeat BTX‐A treatments. The presence of antibodies did not interfere with the response to BTX‐F or BTX‐B injections, thus confirming the antigenic specificity of various BTX serotypes.
P450 enzymes and Parkinson's disease: The story so far
Authors: Riedl Andrew G. , Watts Paul M. , Jenner Peter , David Marsden C.
Published: May 2005

Environmental or endogenous toxins may cause nigral cell death in Parkinson's disease (PD) as a result of genetic susceptibility conferred by altered expression of P450 enzymes. Attention over the last 10 years has focused on CYP2D6 polymorphisms and susceptibility to PD. This review summarizes reports arising from both phenotypic and genotypic studies involving CYP2D6 and PD. Phenotypic studies have failed to support a link between CYP2D6 and PD. The more powerful genetic studies initially indicated a link between CYP2D6B mutations and PD, but critical analysis of the literature and recent studies emerging from independent laboratories fail to confirm this. Mutations in CYP2D6B are also not implicated in familial PD. As yet, there is no conclusive evidence to suggest that CYP2D6 polymorphisms confer susceptibility to PD. Whether polymorphisms in other P450s (for example, CYP1A1 and CYP2E1) are implicated in PD remains to be established.
Late components of the event‐related potentials and their topography in Parkinson's disease
Authors: Lagopoulos Jim , Clouston Paul , Barhamali Homayoun , Gordon Evian , Li Waiman M. , Lesley Julian , Morris John G. L.
Published: May 2005

Late components of the event‐related potential (ERP; N100, P200, N200, and P300) were elicited using an auditory oddball paradigm (with a button‐press response to target stimuli) in 15 Parkinson's disease (PD) patients and 50 normal control subjects. Compared with control subjects, PD subjects showed a significant decrease in N200 amplitude. Between‐group topographical differences in N200 amplitude were evident at central (C3, Cz, C4) and temporal (T5, T3, T4, T6) regions. The results may reflect a deficit in response selection in PD possibly resulting from a dysfunction associated with the abnormalities in the central and temporal regions found to have a decreased N200 amplitude compared with normal control subjects in this study.
Verapamil for severe hyperkinetic movement disorders
Authors: Ovsiew Fred , Meador Kimford J. , Sethi Kapil
Published: May 2005

The use of verapamil in three cases of severe hyperkinetic movement disorders resulted in dramatic improvement in patients who had been refractory to many other treatments over a prolonged period. A videotape illustration of one of the patients is provided. The mechanism of action and evidence of efficacy of calcium‐channel blockers for abnormal movements are discussed.
Clinical assessment of olfactory dysfunction in Parkinson's disease
Authors: Potagas Constantin , Dellatolas George , Ziegler Marc , Leveteau Jean , Bathien Nguyen , Leod Patrick Mac , Rondot Pierre
Published: May 2005

We used two simple tasks to test the capacities of patients with Parkinson's disease to discriminate and identify olfactory stimuli. The patients presented defective odor identification abilities whereas their capacity to discriminate between odors was apparently unaffected. This raises a question about the nature of olfactory dysfunction in Parkinson's disease. Further clinical data is required for analysis of this dysfunction. We therefore propose simple and rapid tests appropriate for clinical use with Parkinson's disease patients.
The health burdens of Parkinson's disease
Authors: Chrischilles Elizabeth A. , Rubenstein Linda M. , Voelker Margaret D. , Wallace Robert B. , Rodnitzky Robert L.
Published: May 2005

Parkinson's disease (PD) is likely to have a substantial impact on an individual's health‐related quality of life (HRQL), health‐related resource use, and productivity. Data about the health burdens of PD by disease stage are fundamental to understanding the effectiveness of care, both from a clinical and a fiscal point of view. This study's goal was to describe the associations of patient‐reported HRQL and economic characteristics with PD stage. We hypothesized that later stages of PD would be associated with poorer HRQL, greater health‐related resource use, and lower work productivity than early stages of PD. We used a cross‐sectional analysis to study 193 PD patients attending two hospital‐based neurology clinics. Self‐administered questionnaires and in‐person interviews measured clinical features, functional status, general health perceptions, well‐being, overall HRQL, work productivity, and health‐related resource use. Consistent, strong associations were found between stage and functional status, general health perceptions, well‐being, and overall HRQL even after controlling for age, gender, and comorbid conditions. Most resource use and work productivity measures were also associated with disease stage. However, physician services use was not. This study confirms that the burdens of illness are progressively higher for PD patients with early, moderate, and advanced illness. The results suggest that such important facets of the health burden as HRQL and health‐related resource use may be seriously misjudged if not carefully measured but inferred from clinical observations alone.
Comparison of acute‐ and delayed‐onset posttraumatic cervical dystonia
Authors: Tarsy Daniel
Published: May 2005

Head, neck, or shoulder trauma is an occasional antecedent event before the appearance of cervical dystonia. A clinically distinctive syndrome of acute‐onset posttraumatic cervical dystonia characterized by markedly restricted range of neck motion, absence of phasic involuntary movements, and poor response to treatment has previously been described. Patients with cervical dystonia attending a movement disorder clinic were reviewed for history of trauma before onset of symptoms. Patients with symptom onset within 4 weeks of trauma were compared with patients who developed symptoms between 3 months and 1 year after trauma. Acute‐onset cervical dystonia was characterized by markedly reduced cervical mobility; prominent shoulder elevation with trapezius hypertrophy in most patients, absence of involuntary movements, sensory tricks, or activation maneuvers; and poor response to botulinum toxin injection. By contrast, delayed‐onset cervical dystonia was clinically indistinguishable from nontraumatic idiopathic cervical dystonia. Acute‐onset posttraumatic cervical dystonia is similar to limb dystonia after peripheral trauma and may represent a form of nondystonic muscle spasm similar to torticollis associated with musculoskeletal injuries of the cervical spine and craniocervical junction.
Voluntary palatal tremor in two siblings
Authors: Klein Christine , Gehrking Eckart , Vieregge Peter
Published: May 2005

We report two siblings with palatal tremor (PT) and ear clicks who can voluntarily elicit or suppress both PT and ear clicks by just “thinking” about starting or stopping the sounds. The patients were also able to voluntarily modulate the frequency of their ear clicks and PT. They did not have any signs of cerebellar, brain stem, or other neurologic disease. These familial palatal movements may represent a variant of palatal tremor but can not satisfactorily be classified as either symptomatic or essential PT.
Progressive pseudobulbar paresis, early choreiform movements, and later rigidity: Appearance in two sets of dizygotic twins in the same family
Authors: Johnson Sturla E. , Dahl Arve , Sjaastad Ottar
Published: May 2005

In a family with two sets of dizygotic twins, three, possibly all four, siblings were affected by the same disorder. The parents were unrelated and the illness seemed limited to one generation. Onset was in the early to mid‐20s with tics and choreiform movements, dysarthria, and dysphagia. Two twins had epilepsy. There was a marked dyscoordination of bulbar musculature reminiscent of pseudobulbar paresis. Involuntary movements were prominent during the first years, but then disappeared and were replaced by an akinetic‐rigid parkinsonian appearance in the late stage. The intellect remained largely intact. Tendon reflexes were reduced. Varying degrees of peripheral nerve changes were seen. Two patients died after 22–24 years from causes indirectly related to the main illness. Marked degenerative changes were found in the caudate nucleus and putamen. Acanthocytes in significant numbers could not be detected in peripheral blood. Lipoproteinelectrophoresis was normal. Creatine kinase levels were moderately raised in one patient, normal in the others. Although certain clinical resemblances exist with neuroacanthocytosis, the exact nosologic status of the disorder has not been determined.
[3H]‐2‐Deoxyglucose uptake study in mutant dystonic hamsters: Abnormalities in discrete brain regions of the motor system
Authors: Richter Angelika , Brotchie Jonathan M. , Crossman Alan R. , Löscher Wolfgang
Published: May 2005

The genetically dystonic (dtsz) hamster, an animal model of idiopathic paroxysmal dystonia, displays attacks of generalized twisting movements and abnormal postures of limbs and trunk either spontaneously or in response to mild stress. This experimental model may be helpful to give insights into the pathophysiology of idiopathic dystonia in man. In the present study, the regional uptake of [3H]‐2‐deoxyglucose (2‐DG) was examined in brains (75 brain regions) of dtsz hamsters during the expression of severe dystonia. 2‐DG autoradiography revealed significant changes of 2‐DG uptake in discrete brain regions of dtsz hamsters compared with age‐matched, nondystonic control hamsters. In dystonic hamsters, a dramatic increase of 2‐DG uptake was observed in the red nucleus (159% over control). Furthermore, enhanced 2‐DG uptake was found in the ventromedial, ventrolateral, and anteroventral nuclei of the thalamus (19–42%) and in the medial vestibular nucleus (23%). A significant decrease in 2‐DG uptake in deep cerebellar nuclei (‐30%) may be the result of decreased synaptic activity of GABAergic neurons within these structures resulting in enhanced excitatory output to red nucleus, thalamic, and vestibular nuclei. In dtsz hamsters, the 2‐DG uptake was not significantly altered overall within the basal ganglia. Significant increase of 14% were, however, found in discrete parts of the caudate putamen in which recent studies revealed changes of dopamine receptors. Altered neural activity within the basal ganglia may therefore contribute to increased 2‐DG uptake in the ventral thalamic nuclei as well as to decreased 2‐DG uptake (‐13%) found in the reticular thalamic nucleus. Although the present data are in line with the concept that abnormal thalamocortical activity seems to be critically involved in the dystonic syndrome, altered activities in other motor areas than output structures of the basal ganglia, such as in the red nucleus, may contribute to clinical manifestation of dystonia in mutant hamsters.
Huntington's disease confirmed by genetic testing in five african families
Authors: Silber E. , Kromberg J. , Temlett J. A. , Krause A. , Saffer D.
Published: May 2005

Huntington's disease is an autosomal‐dominant inherited progressive neurodegenerative disease associated with an expanded trinucleotide repeat (CAG) sequence on the short arm of chromosome 4. The disease is considered rare in Africans. We report five black South African families of different ethnic origin with proven expansions typical of Huntington's disease and discuss the possible origins of the disease in Africa.
Orthostatic tremor: An electrophysiological analysis
Authors: Sander Howard W. , Masdeu Joseph C. , Tavoulareas George , Walters Arthur , Zimmerman Thomas , Chokroverty Sudhansu
Published: May 2005

Orthostatic tremor (OT) is a clinically defined syndrome of leg tremor while standing. Controversy surrounds whether OT is a distinct syndrome or is an essential tremor (ET) variant. We report two patients with OT. Electrophysiological testing included polymyography, accelerometry, nerve conduction, and evoked potential studies. The effects of various maneuvers and body positions on the tremor were assessed. The findings included rapid (15–17 Hz) lower‐extremity tremor burst frequency evoked by standing but not by walking or swaying; rapid upper‐extremity burst pattern synchronous with lower‐extremity bursts; and failure of electrical stimulation or mental concentration to “reset” the tremor. Additionally, there was the novel finding of accelerometric recordings in the legs revealing the same rapid frequency (16–17 Hz) as the electromyographic tremor bursts. Some prior reports have suggested that OT is related to ET by emphasizing a considerable disparity and variability between the accelerometric tremor frequency and the electromyographic burst frequency. In our patients, however, the rapid (15–17 Hz) accelerometer‐recorded tremor synchronous with the electromyographic bursts, and also the clinical improvement with clonazepam but not beta blockers or mysoline, and the lack of a family history of ET provide support that OT is distinct from ET.
1H Magnetic resonance spectroscopy of the lentiform nucleus in primary focal hand dystonia
Authors: Naumann Markus , Warmuth‐Metz Monika , Hillerer Claudia , Solymosi László , Reiners Karlheinz
Published: May 2005

Several radiologic findings point toward the lentiform nucleus as a possible site of lesion in primary dystonia. Histologic examinations, however, have shown inconsistent results. 1H‐magnetic resonance spectroscopy (MRS) has proved helpful to assess neuronal degeneration in a variety of basal ganglia disorders. MRS data of dystonia patients are, however, lacking so far. 1H‐MRS centered on the lentiform nuclei was performed in 14 patients with primary focal hand dystonia and in 12 healthy control subjects using a 1.5‐T MR imager. No statistically significant differences of N‐acetylaspartate/creatine and lactate/creatine ratios were found between patients and control subjects. Based on these data, the authors found no evidence that primary focal dystonia was associated with a conspicuous loss of lentiform nucleus neurons or a marked disturbance of the aerobic metabolism, although minor abnormalities cannot be excluded because of the possibly limited sensitivity of the method.
Mexiletine in the treatment of spasmodic torticollis
Authors: Ohara Shinji , Hayashi Ryoichi , Momoi Hiroki , Miki Jun , Yanagisawa Nobuo
Published: May 2005

We studied the clinical efficacy of mexiletine, a derivative oral form of lidocaine, for treatment of spasmodic torticollis. One of the nine subjects of this study was previously reported. Before starting oral mexiletine, normal saline was first injected intravenously as placebo control; lidocaine infusion then followed and clinical evaluation was provided by dystonia rating scale scores, videotape recordings, and surface electromyographic recording. In all patients, lidocaine injection resulted in a decrease of dystonic muscle contractions within 5 minutes and the effect lasted approximately 1 hour. With gradual increase of mexiletine dose, similar clinical improvement was obtained with oral doses ranging from 450–1200 mg/day for more than 6 months. Side effects in six of nine patients included upper gastrointestinal symptoms, dizziness, ataxia, and dysarthria. These were tolerable or medically manageable; only one patient required a small reduction in mexiletine dose. Strong positive correlation was found between serum and cerebrospinal fluid (CSF) mexiletine concentrations with a CSF/serum ratio of 0.6 (r = 0.96, p = 0.0005) suggesting its effective penetrance into the central nervous system. We suggest that oral mexiletine therapy may be a safe and effective treatment for spasmodic torticollis.
Acute movement disorders with bilateral basal ganglia lesions in uremia
Authors: Wang Han‐Cheng , Brown Peter , Lees Andrew J.
Published: May 2005

Acute and subacute extrapyramidal movement disorders are rarely reported in uremic patients. We report three such cases with basal ganglia lesions. All three had advanced renal failure with high serum creatinine levels. One of the patients had a history of ischemic heart disease and acute pulmonary edema with hypoxemia. Another patient had experienced arterial hypotension during previous hemodialysis. The third had prominent metabolic acidosis. One of the patients developed generalized dyskinesias, whereas the other two developed gait disturbances. Neuroimaging studies in all three cases showed bilateral changes in the basal ganglia. The natural history was self‐limiting with gradual improvement. Diminution of the basal ganglia lesions was demonstrated on follow‐up imaging in two of the three cases. We conclude that acute or subacute movement disorders with bilateral basal ganglia lesions may occur in uremia. Hypoperfusion with global brain ischemia and selective vulnerability of the basal ganglia to uremic toxins may account for these lesions.
Adsorption of ethoxylated alkylphenol–formaldehyde polymeric surfactants at the aqueous solution–air interface
Authors: Gendy Tahany S. , Barakat Youssef , Mead Attia I.
Published: May 2005

The adsorption behaviour of some ethoxylated alkylphenol–formaldehyde polymeric non‐ionic surfactants, at the aqueous solution–air interface, was investigated by measuring the surface tension (γ) as a function of concentration (C) at four temperatures. By applying the Gibbs adsorption equation to the γ versus C data, the adsorption isotherms of these polymeric surfactants were obtained.

Surface concentration (Λ) of the investigated polymeric non‐ionics was found to increase with decreasing temperature and decreasing hydrophobic group (R) chain length, while varying the length of polyoxyethylene chain (%EO) appeared to have an insigificant effect. Effects of temperature, %EO and chain length R on the surface pressure (π) of the surfactant solutions were also investigated.
Synthesis and characterisation of polyamides and polyimides from methylene bis[benzenamine] styryl pyridines
Authors: Peesapati V. , Rao U. Narasimha , Pethrick Richard A.
Published: May 2005

Two diamines with potential non‐linear optical characteristics, (E)‐4, 4′‐[[[2‐(4‐pyridinyl)ethenyl]phenyl]methylene]bis[benzenamine] (2a) and (E)‐4, 4′‐[[[2‐(4‐pyridinyl)ethenyl]phenyl]methylene]bis [N‐ethylbenzenamine] (2b), were condensed with dianhydrides, benzophenone tetracarboxylic dianhydride and pyromellitic dianhydride, to obtain polyamic acids. These polyamic acids were soluble in polar aprotic solvents such as dimethyl formamide and dimethyl acetamide, and could be cast into transparent, tough and flexible films, which on cyclodehydration yield amorphous thermally stable polyimides. Characterisation using IR spectroscopy, X‐ray diffraction, thermogravimetric analysis and differential scanning calorimetry are reported.
Effects of rubbers and thermoplastics as additives on cyanate polymerization
Authors: Cao ZhiQiang , Mechin Françoise , Pascault Jean‐Pierre
Published: May 2005

Several rubber (acrylonitrile–butadiene copolymer) or thermoplastic (polyethersulfone) additives bearing different chain ends were introduced into pure aromatic dicyanates. We studied the influence of these initially miscible modifiers on the polymerization kinetics, as a function of their chemical structure and concentration. It appears that apart from those bearing a labile hydrogen atom, the additives play almost no role on the polycyclotrimerization rate; neither does phase separation. However, the additives influence the structure of the final networks insofar as they partially dissolve in the matrix and thus modify both the final Tg and the onset of vitrification, compared with the pure monomer. Finally, the amino‐ or phenolic additives can react with cyanate functions and produce adducts which are well‐known catalysts for cyanate cyclotrimerization; in their presence, a marked enhancement of the polymerization rate can thus be observed, together with the thermal effects mentioned above.
Glass polyalkenoate dental cements based on physical blends of poly(acrylic acid) and poly(vinyl phosphonic acid)
Authors: Akinmade Ademola O. , Braybrook Julian H. , Nicholson John W.
Published: May 2005

Physical blends of spray‐dried poly(acrylic acid), PAA, with poly(vinyl phosphonic acid), PVPA, have been prepared and used in experimental dental cements by mixing them with basic sub‐45 μm acid‐degradable fluoroaluminosilicate glass powders and adding water. The effect of varying the ratio of PAA to PVPA, of altering the molar mass of PAA, and of using glasses of differing basicity have been investigated. The compressive strengths of the best of the cements formed from these blends were comparable to those formed from the individual polyacids, i.e. about 160 MPa.
Structural analysis of an interphase region of isotactic polypropylene
Authors: Włochowicz Andrzej , Garbarczyk Józef
Published: May 2005

Small‐angle X‐ray scattering (SAXS) data have been used to deduce the localization of organic additives in the bulk of isotactic polypropylene (iPP). The results have shown that changes in the thickness of a transition layer are not directly connected with the introduction of additives but with the content of the hexagonal β‐form. This leads to the conclusion that the additives are placed in the amorphous phase in spite of their crucial influence on the formation of the crystalline phase of iPP.
Temperature dependence of unperturbed dimension and interaction parameters of polyester resin in solvents
Authors: Devi G. Rama , Narender G. , Raju K. V. S. N. , Yaseen M.
Published: May 2005

The flow behaviour of a polyester in various solvents was studied at temperatures ranging from 10 to 80°C. The practical data obtained from the temperature dependence of limiting viscosity number [η] were used to calculate unperturbed dimensions and interaction parameters of the polyester resin in poor, moderate and good solvents. The data provided information regarding conformational transitions in the polymer chains in terms of exothermic or endothermic local ordering of solvents on resin segments and their fixation on polymer coils. The temperature dependence of unperturbed dimensions Ke, Flory–Huggins interaction parameter χ12, the second virial coefficient A2, entropy parameter U1, enthalpy parameter K1, and viscosity expansion factor αn, has been used to estimate the solvent quality for the resin.
Synthesis and binary copolymerizations of 2‐pyrimidyl acrylamide with different alkyl acrylates, vinyl acetate and acrylonitrile
Authors: Hamouly S. H. El , Azab M. M.
Published: May 2005

2‐Pyrimidyl acrylamide (2PA) monomer was prepared by the reaction of 2‐aminopyrimidine with acryloyl chloride. Its structure was confirmed by IR, 1H NMR, and MS spectroscopy. Binary copolymerizations of this new monomer with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BuA), methyl methacrylate (MMA), vinyl acetate (VA), and acrylonitrile (AN) were performed in tetrahydrofuran, using 1 mol% azobisisobutyronitrile as initiator at 65°C. N analysis and 1H NMR spectroscopy were used to determine the composition of the copolymers. Copolymerization parameters for each system were calculated by both the Fineman & Ross and Kelen & Tüdös methods. The monomer reactivity ratios for the systems 2PA–MA, 2PA–EA, 2PA–BuA, 2PA–MMA, 2PA–VA, and 2PA–AN were found by the Kelen & Tudos method to be r1 = 0.58±0.042, r2 = 1.26±0.086; r1 = 0.63±0.041, r2 = 1.04±0.072; r1 = 0.88±0.051, r2 = 0.99±0.069; r1 = 0.43±0.021, r2 = 1.60±0.094, r1 = 0.69±0.051, r2 = 0.084±0.088; and r1 = 0.065±0.008, r2 = 2.54±0.220, respectively. The average Q and e values for 2PA were found to be 0.51 and 0.66, respectively.
Photografting of acrylamide on ethylene–vinyl alcohol copolymer film
Authors: Kubota Hitoshi , Sugiura Atsushi , Hata Yasuo
Published: May 2005

Photografting (λ > 300nm) of acrylamide on ethylene‐vinyl alcohol copolymer film (vinyl alcohol unit = 56 mol%, film thickness = 20μm) was investigated at 60°C in water medium, where photoinitiators were coated on the film earlier. The percent grafting decreased in the order of xanthone ≈ benzophenone > anthraquinone > benzoyl peroxide. The graft efficiencies in each sensitized system were less than 30%, showing a predominant formation of homopolymer. Grafting of acrylamide on the film was also initiated in systems with and without photoirradiation when ceric salt was used as an initiator. Based on electron probe microanalysis of the grafted films, the grafted chains of the sample prepared by photografting were distributed inside the film, while those of the sample prepared by ceric salt‐initiated grafting without photoirradiation were located mainly on the film surface. The grafted films prepared by the former system exhibited a higher moisture permeability than those prepared by the latter system.
Synthetic resins XXIX: Synthesis and characterisation of the resins derived from 2,4‐dinitrophenylhydrazone derivatives of resacetophenone–furfural–substituted hydroxy‐aromatic compounds
Authors: Aich Ritanjali , Lenka S. , Nayak P. L.
Published: May 2005

A number of resins were synthesised by reacting 2,4‐dinitrophenylhydrazone derivatives of resacetophenone with substituted aromatic compounds and furfural in the presence of some acid and basic catalysts. The physicochemical properties of the resins are reported. The resins were characterised by their IR and NMR spectra. The ion exchange properties of the resins and the influence of electrolytes on the metal uptake of Cu2+, Co2+, Zn2+, Mn2+ and Mg2+ were studied. The distribution of metal ions at different pH are also reported. The thermal properties of the resins were evaluated by TGA, and kinetic parameters were evaluated using the Freeman–Anderson, Broido, Piloyan–Novikova, Coats–Redfern and Horowitz–Metzger methods.
Kinetic analysis of seeded emulsion polymerization of vinyl acetate
Authors: Lange David M. , Poehlein Gary W. , Hayashi Sadao , Komatsu Akihiko , Hirai Toshihiro
Published: May 2005

Particle number and size data from a series of seeded, emulsifier‐free, vinyl acetate emulsion polymerization experiments have been analyzed with the aid of polymerization and particle growth models. A secondary population of particles, with a significantly greater number concentration than the seed, was nucleated in all experiments. The two populations (seed and new) had rather narrow size distributions and large diameters. Hence the reactions were in the area normally associated with Smith–Ewart Case III kinetics. Water‐phase termination reactions can be important in this reaction region but radical desorption from such large particles does not significantly influence the kinetics. The results of the analysis were used to evaluate the magnitude of water‐phase termination; to estimate radical capture coefficients; and to evaluate competitive particle growth.
Synthesis and characterization of polyamides containing s‐triazine rings in the main chain
Authors: Sarwade Bhimrao D. , Mahajan Sudhakar S.
Published: May 2005

Polyamides were synthesized from diacids containing a s‐triazine ring and two aromatic diamines, namely 4,4′‐diaminodiphenyl ether (ODA) and 4,4′‐diaminodiphenylmethane (MDA), by direct polycondensation using the phosphorylation reaction. Polymers thus obtained were characterized by viscosity measurement, IR spectroscopy, thermogravimetry, X‐ray diffraction, and solubility tests. These polyamides had inherent viscosities in the range of 0.51–0.77 dL/g, and were amorphous in nature. All the polymers were readily soluble in various organic solvents and did not lose weight below 270°C in air.
New TiPTMO and ZrPTMO ceramer hybrid materials prepared by the sol gel method: Synthesis and characterization
Authors: Wang B. , Wilkes G. L.
Published: May 2005

New transparent flexible hybrid network “ceramer” materials have been synthesized by incorporating triethoxysilane capped polytetramethylene oxide with highly reactive titanium isopropoxide or zirconium n‐propoxide without adding chelating agents. Both of these types of ceramer materials display high transparency while the zirconium systems show considerable transparency in the UV region. The titanium systems exhibit higher refractive index than the corresponding zirconium materials of equal alkoxide content.
Surface properties and abhesion of undecyl oxazoline block and homopolymers
Authors: Cai Gangfeng , Litt Morton H. , Krieger Irvin M.
Published: May 2005

The surface properties of three undecyl oxazoline homopolymers and two phenyl/undecyl oxazoline block copolymers (as comparison) were studied. After coating on glass slides and annealing, all films had a low critical surface energy of 21 dynes/cm. Water contact angles were higher than 107° for the most hydrophobic films. The deduction that the polymer surfaces contained close‐packed methyl groups was further confirmed by electron spectroscopy chemical analysis (ESCA) angle profiling on an annealed undecyl oxazoline homopolymer film. A model was developed for the variation of elemental ratios as a function of photoelectron take‐off angle. This verified that the polymer films had the polymer backbones parallel to the surface with the undecyl tails oriented toward the surface. When these block and homopolymers were coated on copy paper and glass slides, the peel strengths of pressure‐sensitive adhesives with these surfaces were very low for short dwell times at room temperature. At long dwell times or at elevated temperatures, the peel strengths remained low for the homopolymers but increased greatly for the block copolymers to values higher than those in the tape on glass. After 24 h at 70°C, ESCA analysis showed that the adhesive diffused into the phenyl block domains of the diblock copolymer, generating high peel strength and cohesive failure. However, under the same annealing conditions, the triblock copolymer showed adhesive failure while peel strength increased. ESCA analysis showed very litle diffusion of the adhesive into the triblock copolymer. The homopolymers were stable toward vinyl acetate type adhesives even at elevated temperature; they were abhesive up to 100°C with no interdiffusion.
Counterion binding to cationic polyelectrolytes in aqueous solution
Authors: Ríos Hernán E. , Gamboa Consuelo , Ternero Gerardo
Published: May 2005

The mean ion activity coefficient, (γ±)px/(γ±)salt for different high‐linear charge density cationic polyelectrolyte fluoride, bromide, chloride and nitrate has been determined. The order found is: F− > CI− ≧ Br− > NO. The results obtained with added nitrate were compared with those predicted by Iwasa, Guéron, and Weisbuch and Manning's models. The latter presents the best agreement for polyion chloride and bromide. It was possible to establish the most probable microconfiguration for the polyions studied here. Manning's theory gives a moderate agreement for polyion fluoride values compatible with a lower charge density than for polyelectrolyte chloride and bromide.
Particle Technology – Manipulating the Divided
Authors: Scarlett Brian
Published: May 2005

Particle Technology is a broad and multidisciplinary subject of great importance but diffuse in definition. In this paper a view is presented of the underlying science and its technological applications. In particular a structured subject is dependent upon characterization techniques from which predictions can be made. In this paper the interrelationship between macroscopic and microscopic characterization is discussed. The standardisation and development of the microscopic techniques, particle analysis, is identified as the key to the development of the whole subject.
The Application and Potential of Cluster Analysis in the Interpretation of multivariate particulate data
Authors: Cooke Steven P. , Butters Gordon
Published: May 2005

The classification of powders into groups possessing specific behavioural identities has long been recognized as desirable. This has been approached by describing different powders using two variables and plotting the data on a scatter diagram. The property of interest is then inferred from a powder's position on the scatter diagram. Unfortunately, a powder's behaviour is rarely adequately described by only two variables. To describe a powder more fully requires more variables and this presents a problem in interpretation. Cluster analysis refers to a range of techniques for interpreting multivariate data sets and is used in many fields. This paper describes cluster analysis and considers the method and potential of its application to particle technology. By way of an illustration, a cluster analysis has been performed on twenty‐seven powders resulting in groups recognizable by their characteristic fluidisation and flow properties. It is concluded that cluster analysis could be a powerful tool in predictive and analytical work in the field of particle technology.
Particle Size Analysis of Heterogeneous Powders by Sedimentation
Authors: Bernhardt Claus
Published: May 2005

It is often necessary to carry out sedimentation analysis of powders, consisting of two or more components, which differ in some physical properties. By means of theoretical studies of twocomponent systems the systematic errors of the measured particle size distributions were analysed for the case that differences exist in the following combinations of properties:

–particle size distribution D(x) and solid density ϱs

–D(x) and mass absorption coefficient μm

–D(x) and ϱs and μm

Using real systems (SiO2 + Fe2O3, Al2O3 + SiO2, Al2O3 + Fe2O3) the partial and total errors were estimated and compared with the results obtained with a Sedigraph. Differences in the density of the components often result in negligible errors, even for the system SiO2 + Fe2O3, if the mass portion of one component is below about 10%. For the total error the differences of μm and D(x) are decisive. Its value is below 1% if the mass portion of the slightly absorbing component is <5% or if the strongly absorbing component is <1%.