bluuebunny/crossref_metadata_2025 huggingface dataset:
Convivial communication: recontextualizing communicative competence
Authors: Leung Constant
Published: June 2005

The advent of the concept of communicative competence in English Language Teaching (ELT) over thirty years ago signalled a shift from grammar‐based pedagogy to Communicative Language Teaching. It was generally accepted that, in addition to grammar rules, language teaching needed to take account of social context and social rules of use. The concept of communicative competence, initially developed for ethnographic research, appeared to offer an intellectual basis for pedagogic broadening. The transfer of this concept from research to language teaching has, however, produced abstracted contexts and idealized social rules of use based on (English language) native‐speakerness. Drawing on recent work in the fields of World Englishes, English as a lingua franca and Second Language Acquisition, this article argues that it is imperative for ELT to take notice of real‐world social, cultural and language developments in contemporary conditions and to re‐engage with a set of reformulated ethnographic sensitivities and sensibilities.
The evolving sociopolitical context of immersion education in Canada: some implications for program development1
Authors: Swain Merrill , Lapkin Sharon
Published: June 2005

In 1997 Swain and Johnson defined immersion as one category within bilingual education, providing examples and discussion from multiple international perspectives. In this article, we review the core features of immersion program design identified by Swain and Johnson and discuss how current sociopolitical realities and new research on second language learning serve to update and refresh the discussion of these features. One feature identified by Swain and Johnson is that “the classroom culture is that of the local L1 community”. The dramatic increase in ethnic diversity in Canada's urban centres calls into question the notion of a monolithic culture in the school community. A second example concerns the use of the L1 in the classroom: while a central feature of immersion education is the use of the L2 as medium of instruction, new research suggests that allowing a judicious use of the L1 on the part of learners may be warranted. The article concludes with suggestions for building on multiple L1s in the immersion classroom.
Conversation – more than words. A Norwegian case study of the establishment of a contribution in aphasic interaction
Authors: Lind Marianne
Published: June 2005

The article presents an analysis of the means and processes through which an aphasic speaker with severe limitations in spontaneous speech production is able to make a self‐initiated, substantial contribution in interaction with a non‐aphasic interlocutor. The analytical process is based on the principles of conversation analysis, and the study draws on insights from interactional linguistics. The analysis illustrates the aphasic participant's ability to make himself understood by using several methods of communication and by situating his parts of the contribution in relation to the sequential context. Hence, the analysis reveals an essential form of orderliness and complementarity in what may initially seem like a disorderly piece of interaction. The analysis highlights the need for systematic, functional assessment of communicative and linguistic abilities in aphasia, a perspective with possible consequences for the training and practice of speech and language therapists.
Classification of Migraine and Tension Headache from a Survey of 10,000 Headache Diaries
Authors: Cohen Michael J. , McArthur David L.
Published: June 2005

SYNOPSIS

Descriptions of migraine and muscle tension headaches have been based primarily on retrospective medical histories. To obtain a more accurate picture of symptoms patients use to classify these headaches, a sample of 10,000 headaches was gathered from daily diaries. Patients experiencing both migraine and tension headaches are able to differentiate these disorders consistently, using moderate ratings of intensity, low ratings of disability, and short length for tension headaches, and ratings of relatively high intensity and disability, moderately long duration, and occasional gastrointestinal upset for migraine headaches. These configurations confirm the general view obtained from medical histories.
Fenoprofen in the Prophylaxis of Migraine: A Double—Blind, Placebo Controlled Study
Authors: Diamond Seymour , Solomon Glen D. , Freitag Frederick G. , Mehta Nilesh D.
Published: June 2005

SYNOPSIS

We undertook a double‐blind, placebo controlled study to determine the effectiveness of fenoprofen calcium in the prophylaxis of migraine. One hundred and ten patients were treated with fenoprofen 200 mg. TID (35 patients), fenoprofen 600 mg. TID (39 patients), or matching placebo (36 patients), for 12 weeks, following a four week placebo baseline phase. Migraine frequency, severity, duration, and need for relief medication were recorded using headache diaries. Greater than 50% improvement in headache unit index was observed in 22% of patients on fenoprofen 200 mg. TID (p<0.05) and 36% of patients on fenoprofen 600 mg. TID (p<0.005). Fenoprofen 600 mg. resulted in 50% or greater reduction in corrected headache unit index in 59% of patients (p<0.005) and relief medication index in 55% (p<0.001), Gastrointestinal side effects were reported in 13.5% of patients, and fatigue was noted in 4% of patients treated with fenoprofen 600 mg. TID. We conclude that fenoprofen is safe and effective in the prophylaxis of migraine.
Exercise‐Induced Migraine Prodrome Symptoms
Authors: Thompson J. Kevin
Published: June 2005

SYNOPSIS

Following consumption of a somewhat more than usual amount of coffee, and on a background of only scant food intake that day, a physically‐fit 31 year old male engaged in unusually strenuous running. About an hour after cessation of exercise, he developed, for the first time in his life, symptoms consistent with a migraine prodrome (as a researcher in migraine, the subject was familiar with the symptoms of migraine, though he himself was not a migraine sufferer). No head pain followed. The roles of caffeine, hypoglycemia, and exercise, alone and in combination, require investigation in the evaluation of other cases of exercise‐induced migraine. Also, the occurrence of exercise‐induced prodromes, without headache, may not be correctly interpreted by some subjects unfamiliar with the multiple potential manifestations of migraine.
Focal Headache During Balloon Inflation in the Vertebral and Basilar Arteries
Authors: Nichols Fenwick T. , Mawad Michel , Mohr J.P. , Hilal Sadek , Adams Robert J.
Published: June 2005

SYNOPSIS

Background and Purpose: Headache may be seen in acute cerebrovascular disease. The significance of localized headache in association with vertebrobasilar disease has not been recognized.

Summary of Report: We describe a patient with a cerebellar arteriovenous malformation who underwent intravascular balloon occlusion of the vertebral and basilar artery. He developed reproducible patterns of referred pain with balloon inflation at specific sites.

Conclusions: Well localized head pain in the setting of acute stroke should alert physicians to the possibility of localized arterial injury. The pattern seen in this patient has been documented in experimental situations, and should be of use in the setting of acute stroke.
Vestibulo‐Ocular Reflex in Migraine Patients: The Effect of Sodium Valproate
Authors: Gordon C.R. , Kuritzky A. , Doweck I. , Spitzer O. , Shupak A. , Hering R.
Published: June 2005

SYNOPSIS

We studied vestibulo‐ocular reflex measurements in a group of 12 patients suffering from migraine without aura and evaluated the effect of sodium valproate given as prophylactic migraine therapy. The study was randomized, double blind and placebo controlled, with a crossover design. The horizontal vestibulo‐ocular reflex was evaluated by the Sinusoidal Harmonic Acceleration test at 0.01, 0.02, 0.04, 0.08end 0.16 Hz using a computerized rotatory chair system. No abnormalities were found for the vestibulo‐ocular reflex gain, phase and asymmetry at each of the frequencies examined during the placebotreatment. These normal vestibulo‐ocular reflex measurements contrasted with the repeated complaints of dizziness, vertigo and unsteadiness reported by 7 patients (58%). Sodium valproate affected neither vestibulo‐ocular responses nor vestibular complaints but was effective in reducing migraine attacks in 8 of the 12 patients. These results demonstrate that the low frequency vestibulo‐ocular reflex measurements are normal in patients suffering from migraine without aura.
The Effects of Streptomycin/Lidocaine Block on Trigeminal Neuralgia: A Double Blind Crossover Placebo Controlled Study
Authors: Bittar Geber T. , Graff‐Radford Steven B.
Published: June 2005

SYNOPSIS

This study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double‐blind placebo controlled randomized design was used. After the clinical assessment subjects were randomly assigned to receive either 1 g of streptomycin with 3 ml 2% lidocaine, or 3 ml lidocaine alone. The injections were performed adjacent to the branches that served the painful site. These were intraoral injections, more specifically infraorbital and inferior alveolar blocks. Patients received five blocks of either streptomycin/lidocaine or lidocaine alone for a period of five consecutive weeks. On the sixth week they were crossed over. Measures of pain intensity and pain frequency were used to assess treatment outcome. Patients also recorded their side‐effects. Repeated measures analysis of variance was used to compare the treatment outcomes between the active and placebo groups. There was no statistically significant differences in the treatment outcomes regarding frequency and intensity of pain attacks. The sensory function of the treated nerves was also not affected. Side effects including facial swelling and pain were a common finding in the patients receiving streptomycin. This study demostrated no beneficial effects of streptomycin blockade for idiopathic and traumatic trigeminal neuralgia.
Disruption of Cortical Development as a Consequence of Repetitive Pilocarpine‐induced Status Epilepticus in Rats
Authors: Da Silva Alexandre Valotta , Regondi Maria Cristina , Cavalheiro Esper Abrão , Spreafico Roberto
Published: June 2005

Summary:  Purpose: The aim of the present study was to observe possible cortical abnormalities after repetitive pilocarpine‐induced status epilepticus (SE) in rats during development.

Methods: Wistar rats received intraperitoneal injection of pilocarpine hydrochloride 2% (380 mg/kg) at P7, P8, and P9. All experimental rats displayed SE after pilocarpine injections. Rats were killed at P10 and P35, and immunocytochemistry procedures were performed on 50‐μm vibratome sections, by using antibodies against nonphosphorylated neurofilament (SMI‐311), parvalbumin (PV), calbindin (CB), calretinin (CR), and glutamate decarboxylase (GAD‐65). Selected sections were used for the TUNEL method and double‐labeling experiments, with different mixtures of the same markers.

Results: The major findings of the present work were (a) altered intracortical circuitry development; (b) anticipation of PV immunoreactivity in neocortical interneurons; (c) increased GAD‐65 immunoreactivity; and (d) reduced neocortical apoptotic process.

Conclusions: From these results, we suggest that previously healthy brain, without genetic abnormalities, might develop an “acquired” disruption of cortical development whose evolution reproduces some characteristics of the childhood epilepsies associated with cognitive impairment.
Outcome of Status Epilepticus in Immature Rats Varies According to the Paraldehyde Treatment
Authors: Kubová Hana , Rejchrtová Jana , Redkozubova Olga , Mareš Pavel
Published: June 2005

Summary: Purpose:To test effects of paraldehyde on behavioral outcome of status epilepticus (SE) in developing rats.

Methods:Motor SE was induced by LiCl‐pilocarpine in rats on postnatal (P) day 12 or 25. Two hours after SE onset, animals were injected with a single dose of paraldehyde (0.07 and 0.3 ml/kg in the P12 group and 0.3 and 0.6 ml/kg in the P25 group). Effects on seizure severity and mortality were evaluated. Growth of animals and their motor abilities were monitored until the adulthood. Three months after SE, cognitive abilities were tested by using the Morris water maze.

Results:Both tested doses of paraldehyde equally affected motor seizures. Convulsions continued until the paraldehyde administration, but then they quickly subsided in all groups. During the subsequent 24 h, occasional clonic seizures occurred in P25 animals treated with the lower dose of paraldehyde. Only hyperactivity and/or automatisms were observed in the other experimental groups. Mortality was not affected by the dosage of paraldehyde. The higher dosage of paraldehyde improved recovery after SE in both age groups. No difference was found in motor abilities between controls and SE animals, except shortening of time spent on the rod in the rotarod test in the P12 group. In P25 rats, treatment with a higher dosage of paraldehyde improved learning abilities compared with the lower dosage. In the P12 group, animals treated with the lower dosage exhibited slightly impaired learning compared with controls and animals receiving the higher dosage.

Conclusions:Paraldehyde injected 2 h after SE onset modulates long‐term outcome in immature rats in a dose‐related manner.
Physiological Changes in Chronic Epileptic Rats Are Prominent in Superficial Layers of the Medial Entorhinal Area
Authors: Tolner Else A. , Kloosterman Fabian , Kalitzin Stiliyan N. , Da Silva Fernando H. Lopes , Gorter Jan A.
Published: June 2005

Summary:  Purpose: We investigated whether the functional network properties of the medial entorhinal area (MEA) of the entorhinal cortex were altered in a rat model of chronic epilepsy that is characterized by extensive cell loss in MEA layer III.

Methods: Responses were evoked in the entorhinal cortex by electrical stimulation of the subiculum in anesthetized chronic epileptic rats, 2–4 months after status epilepticus, induced by systemic kainate (KA) injections. Laminar field potentials were measured using a 16‐channel silicon probe that covered all six layers of the MEA; an estimate of the local transmembrane currents was made using current source density analysis.

Results: Double‐pulse stimulation of the subiculum evoked responses in deep and superficial layers of the MEA in control and KA rats. A current sink in layer I and at the border of layer I and II that was induced by antidromic activation of MEA‐II, was much more prominent in KA rats with extensive neuronal loss in MEA‐III than in control rats or KA rats with minor MEA‐III loss. Furthermore, KA rats that displayed MEA‐III loss presented a series of oscillations induced by subicular stimulation in the β/γ‐frequency range (20–100 Hz), which were confined to superficial layers of MEA. These oscillations were never observed in control rats or KA rats with minor MEA‐III loss.

Conclusions: These results indicate that the observed alterations in the superficial MEA responses to subiculum stimulation and the occurrence of β/γ‐oscillations are related phenomena, which are a consequence of altered and impaired inhibition within these MEA layers in chronic epileptic rats.
Changes in Cytochrome Oxidase in the Piriform Cortex after Status Epilepticus in Adult Rats
Authors: Otáhal Jakub , Suchomelová Lucie , Druga Rastislav , Kubová Hana
Published: June 2005

Summary:  Purpose: The piriform cortex is involved in genesis and propagation of temporal lobe seizures. Degenerating neurons demonstrated by FluoroJade B staining are visible early after status epilepticus (SE) as well as after longer intervals. Furthermore, the piriform cortex is activated during an early phase of experimental temporal seizures, as described by magnetic resonance imaging (MRI) studies. It indicates that the early activity of the piriform cortex should be accompanied by increased adenosine triphosphate (ATP) production. Cytochrome oxidase activity in the brain may be used as an endogenous metabolic marker for neurons. The present research studied activity of the cytochrome oxidase separately in the rostral and caudal parts of the piriform cortex after lithium chloride–pilocarpine–induced SE in adult rats.

Methods: SE was induced by a single dose of pilocarpine (40 mg/kg) in LiCl‐pretreated adult Wistar rats. Cytochrome oxidase activity was mapped by optical density on sections stained with histochemistry separately in the rostral and caudal parts of the piriform cortex.

Results: Optical density of the rostral part of the piriform cortex remained nearly unchanged at both 1 week (0.284 ± 0.009 in SE group vs. 0.297 ± 0.005 in controls) and 3 months (0.318 ± 0.007 in SE group vs. 0.333 ± 0.004 in controls) after SE intervals. The caudal part of the piriform cortex showed a decrease of optical density in both groups at 1 week (0.265 ± 0.007 in SE group vs. 0.285 ± 0.009 in controls) and 3 months after SE (0.292 ± 0.006 in SE animals vs. 0.310 ± 0.003 in controls), respectively. Nissl‐stained sections demonstrated a marked neuronal loss and gliosis and/or necrotic cavities through the caudal piriform cortex 1 week after SE.

Conclusions: Our results demonstrated that damage of the piriform cortex is not homogeneous and thus that its parts are differently involved in epileptic activity.
Epilepsy Care in Zambia: A Study of Traditional Healers
Authors: Baskind Roy , Birbeck Gretchen
Published: June 2005

Summary:  Purpose: Most people with epilepsy (PWE) reside in developing countries with limited access to medical care. In sub‐Saharan Africa (SSA), traditional healers (THs) play a prominent role in caring for PWE, yet little is known about epilepsy care by THs. We conducted a multimethod, qualitative study to better understand the epilepsy care delivered by THs in Zambia.

Methods: We conducted focus‐group discussions with THs, in‐depth semistructured interviews with a well‐recognized TH at his place of work, and multiple informal interviews with healthcare providers in rural Zambia.

Results: THs recognize the same symptoms that a neurologist elicits to characterize seizure onset (e.g., olfactory hallucinations, jacksonian march, automatisms). Although THs acknowledge a familial propensity for some seizures and endorse causes of symptomatic epilepsy, they believe witchcraft plays a central, provocative role in most seizures. Treatment is initiated after the first seizure and usually incorporates certain plant and animal products. Patients who do not experience further seizures are considered cured. Those who do not respond to therapy may be referred to other healers. Signs of concomitant systemic illness are the most common reason for referral to a hospital. As a consequence of this work, our local Epilepsy Care Team has developed a more collaborative relationship with THs in the region.

Conclusions: THs obtain detailed event histories, are treatment focused, and may refer patients who have refractory seizures to therapy to other healers. Under some circumstances, they recognize a role for modern health care and refer patients to the hospital. Given their predominance as care providers for PWE, further understanding of their approach to care is important. Collaborative relationships between physicians and THs are needed if we hope to bridge the treatment gap in SSA.
Origin and Propagation of Epileptic Spasms Delineated on Electrocorticography
Authors: Asano Eishi , Juhász Csaba , Shah Aashit , Muzik Otto , Chugani Diane C. , Shah Jagdish , Sood Sandeep , Chugani Harry T.
Published: June 2005

Summary:  Purpose: Ictal electrographic changes were analyzed on intracranial electrocorticography (ECoG) in children with medically refractory epileptic spasms to assess the dynamic changes of ictal discharges associated with spasms and their relation to interictal epileptiform activity and neuroimaging findings.

Methods: We studied a consecutive series of 15 children (age 0.4 to 13 years; nine girls) with clusters of epileptic spasms recorded on prolonged intracranial subdural ECoG recordings, which were being performed for subsequent cortical resection, and in total, 62 spasms were analyzed by using quantitative methods.

Results: Spasms were associated with either a “leading” spike followed by fast‐wave bursts (type I: 42 events analyzed quantitatively) or fast‐wave bursts without a “leading” spike (type II: 20 events analyzed quantitatively). Twenty‐three of the 42 type I spasms but none of the 20 type II spasms were preceded by a focal seizure. A “leading” spike had a focal origin in all 42 type I spasms and involved the pre‐ or postcentral gyrus within 0.1 s in 37 of these spasms. A leading spike was associated with interictal spike activity >1/min in 40 of 42 type I spasms and originated within 2 cm from a positron emission tomography glucose hypometabolic region in all but two type I spasms. Failure to resect the cortex showing a leading spike was associated with poor surgical outcome (p = 0.01; Fisher's exact probability test). Fast‐wave bursts associated with spasms involved neocortical regions extensively at least in two lobes within 1.28 s in all 62 spasms and involved the pre‐ or postcentral gyrus in 53 of 62 spasms.

Conclusions: Epileptic spasms may be triggered by a focal neocortical impulse in a subset of patients, and a leading spike, if present, might be used as a marker of the trigger zone for epileptic spasms. Rapidly emerging widespread fast‐wave bursts might explain the clinical semiology of epileptic spasms.
A Comparative Study of the Effect of Carbamazepine and Valproic Acid on the Pharmacokinetics and Metabolic Profile of Topiramate at Steady State in Patients with Epilepsy
Authors: Mimrod Dorit , Specchio Luigi M. , Britzi Malka , Perucca Emilio , Specchio Nicola , Neve Angela La , Soback Stefan , Levy René H. , Gatti Giuliana , Doose Dennis R. , Maryanoff Bruce E. , Bialer Meir
Published: June 2005

Summary:  Purpose: To compare the influence of enzyme‐inducing comedication and valproic acid (VPA) on topiramate (TPM) pharmacokinetics and metabolism at steady state.

Methods: Three groups were assessed: (a) patients receiving TPM mostly alone (control group, n =13); (b) patients receiving TPM with carbamazepine (CBZ; n = 13); and (c) patients receiving TPM with VPA (n = 12). TPM and its metabolites were assayed in plasma and urine by liquid chromatography–mass spectrometry (LC‐MS).

Results: No significant differences were found in TPM oral (CL/F) and renal (CLr) clearance between the VPA group and the control group. Mean TPM CL/F and CLr were higher in the CBZ group than in controls (2.1 vs. 1.2 L/h and 1.1 vs. 0.6L/h, respectively; p < 0.05). In all groups, the urinary recovery of unchanged TPM was extensive and accounted for 42–52% of the dose (p > 0.05). Urinary recovery of 2,3‐O‐des‐isopropylidene‐TPM (2,3‐diol‐TPM) accounted for 3.5% of the dose in controls, 2.2% in the VPA group (p > 0.05), and 13% in the CBZ group (p < 0.05). The recovery of 10‐hydroxy‐TPM (10‐OH‐TPM) was twofold higher in the CBZ group than in controls, but it accounted for only <2% of the dose. The plasma concentrations of TPM metabolites were severalfold lower than those of the parent drug.

Conclusions: Renal excretion remains a major route of TPM elimination, even in the presence of enzyme induction. The twofold increase in TPM‐CL/F in patients taking CBZ can be ascribed, at least in part, to stimulation of the oxidative pathways leading to formation of 2,3‐diol‐TPM and 10‐OH‐TPM. VPA was not found to have any clinically significant influence on TPM pharmacokinetic and metabolic profiles.
The First Case of Invasive EEG Monitoring for the Surgical Treatment of Epilepsy: Historical Significance and Context
Authors: Almeida Antonio N. , Martinez Victor , Feindel William
Published: June 2005

Summary:  Purpose: Controversy persists about when EEG became a fundamental tool in the preoperative investigation for epilepsy surgery. We revisit Penfield's first use of invasive EEG monitoring, emphasizing its historical importance for the evolution of epilepsy surgery.

Methods: Patients' hospital charts and articles published before 1940 regarding EEG and epilepsy or EEG and cerebral lesions were reviewed to evaluate the historical context of the surgery.

Results: In April 1939, Penfield performed trephination over both temporal regions and placed electrodes on the dura, intending to lateralize seizure origin in a patient with bitemporal epilepsy. The patient underwent serial EEGs with this technique. The final report of the recordings from epidural leads was “continued random delta activity in the left temporal region indicating a cortical lesion on this side.” The pneumoencephalogram showed “the presence of diffuse cerebral atrophy, particularly in the left cerebral hemisphere.” Based on these findings, the patient underwent surgery on April 21, revealing a meningocerebral scar in the posterior part of the left temporal lobe. Brain stimulation and electrocorticography delineated the extent of resection, while preserving the speech area. Seizures did not improve.

Conclusions: We revisit the first case of epidural EEG monitoring for epilepsy surgery and show that the concept of EEG‐directed surgery was already present at the Montreal Neurological Institute in the late 1930s.
Peripheral blood progenitor cell collection in chronic myeloid leukemia patients with complete cytogenetic response after treatment with imatinib mesylate
Authors: Perseghin Paolo , Gambacorti‐Passerini Carlo , Tornaghi Lucia , Dassi Maria , Pioltelli Pietro , Parma Matteo , Colnaghi Federica , Giudici Giovanni , Elli Elena , Fumagalli Monica , Ponchio Luisa , Biondi Andrea , Pogliani Enrico M.
Published: June 2005

BACKGROUND:  Imatinib mesylate (IM) was introduced in chronic myeloid leukemia (CML) treatment in the late 1990s and substantially changed the therapeutic approach to the disease, by inducing complete cytogenetic response (CCR) in approximately 60 percent of cases. Nevertheless, some concerns exist about the duration of response to treatment and the onset of resistance to IM.

STUDY DESIGN AND METHODS:  Twenty‐five chronic‐phase CML patients in stable CCR (>6 months) treated for at least 1 year with IM at the standard dose (400 mg/day) were mobilized with recombinant human granulocyte–colony‐stimulating factor (Filgrastim) at 10 µg per kg for 4 to 6 days, with the aim of collecting at least 2 × 106 CD34+ cells per kg. Standard cytogenetic analysis and first‐round and/or nested polymerase chain reaction were performed in basal and postmobilization samples to examine the presence of bcr‐abl transcripts.

RESULTS:  CD34+ cells collection was successful in 16 patients, yielding a median of 3.01 × 106 ± 1.09 × 106 CD34+ cells per kg at the first attempt, and in 4 of the 9 remaining patients who were remobilized after a temporary withdrawal of IM, yielding a median of 2.65 × 106 ± 0.7 × 106 CD34+ cells per kg, with an overall 80 percent success rate. No correlation between mobilization and duration of the disease, length of IM treatment, or previous interferon‐α and/or hydroxyurea treatment was found.

CONCLUSIONS:  Autologous CD34+ cells may be mobilized and collected in most CML patients who achieve CCR after IM treatment, with a view to possible use in the event that resistance to IM occurs in patients not eligible for allogeneic peripheral blood progenitor cell transplantation or those lacking an HLA‐matched donor.
Characterization of the alloreactive helper T‐cell response to the platelet membrane glycoprotein IIIa (integrin‐β3) in human platelet antigen‐1a alloimmunized human platelet antigen‐1b1b women
Authors: Sukati Hosea , Bessos Hagop , Barker Robert N. , Urbaniak Stanislaw J.
Published: June 2005

BACKGROUND: The aims were to characterize the helper T‐cell response to platelet (PLT) glycoprotein (GP) IIIa, which stimulates the alloimmune antibody response to human PLT antigen (HPA)‐1a, to identify immunodominant epitopes and to examine the HLA Class II associations.

STUDY DESIGN AND METHODS: Peripheral blood mononuclear cells (PBMNCs) were obtained from 21 HPA‐1b1b women who had an HPA‐1a–mismatched pregnancy, 14 of whom developed anti‐HPA‐1a, and 11 control donors. PBMNCs were stimulated with two panels of 15‐mer peptides corresponding to the HPA‐1a/1b polymorphic region, with either Leu33 (‐1a) or Pro33 (‐1b) at each possible position, and the proliferative responses were measured. HLA Class II and HPA genotyping was by conventional polymerase chain reaction–sequence‐specific priming.

RESULTS: Peptides with Leu33 at, or near, the C‐terminus contained an immunodominant epitope, stimulating proliferation by helper T cells from all nine women who had anti‐HPA‐1a at the time of testing; peptide L1 (Val19‐Leu33) stimulated a response in 50 percent of these women. Their T cells did not respond to the corresponding HPA‐1b Pro33 peptides, and responses to either peptide panel were rare in unimmunized women and controls. HLA‐DRB3*01+ was significantly overrepresented (p = 0.014) in alloimmunized women whose T cells responded to the major HPA‐1a Leu33‐containing epitope. Conversely, HLA‐DRB1*15 was negatively associated (p = 0.014) with this response.

CONCLUSIONS: The HPA‐1a polymorphic region of GPIIIa contains both the linear T‐cell and the conformational B‐cell epitopes. The immunodominant T‐cell epitope is constrained by HLA‐DRB3*01+, and if presented by a tolerogenic route, a peptide containing this epitope may form the basis for the prevention or reversal of the alloimmune response to HPA‐1a.
Factors affecting the formation of white particulate matter in red blood cell components
Authors: Patel Hina D. , Byrne Karen M. , Horne McDonald , Leitman Susan F. , Stroncek David F.
Published: June 2005

BACKGROUND: Recently white particulate matter (WPM) in red blood cell (RBC) components has received increased attention. The nature and causes of WPM formation were investigated.

STUDY DESIGN AND METHODS: Whole‐blood units were collected from 18 healthy subjects with three different types of collection sets. Six units were collected into each type. Units were divided into four equal parts and stored for 4 hours: two parts at room temperature and two at 4°C. RBCs were prepared from each quarter‐unit: two by heavy centrifugation (5000 × g) and two by light centrifugation (2000 × g). Whole blood was inspected for WPM over 4 hours and RBCs over 1 hour.

RESULTS: No WPM was detected in whole blood, but WPM was detected in at least one RBC component from 9 of the 18 donations. The 36 components prepared by heavy centrifugation were more likely to contain WPM than the 36 prepared by light centrifugation (50% vs. 19%; p < 0.02). The incidence of WPM was similar among RBCs stored at room temperature and 4°C. Donors of RBCs with WPM had higher total cholesterol levels than donors of components without WPM (191 ± 20 mg/dL vs. 163 ± 32 mg/dL; p < 0.04), but there was no difference in triglyceride levels between the two groups.

CONCLUSIONS: WPM is an expected consequence of standard RBC manufacturing methods, but it is more frequent in RBCs prepared by heavy centrifugation and from donors with higher cholesterol levels.
Maturation of Rhodococcus equi‐Containing Vacuoles is Arrested After Completion of the Early Endosome Stage
Authors: Fernandez‐Mora Eugenia , Polidori Marco , Lührmann Anja , Schaible Ulrich E. , Haas Albert
Published: June 2005

Rhodococcus equi is a facultative intracellular bacterium that can cause bronchopneumonia in foals and AIDS patients. Here, we have analyzed R. equi‐containing vacuoles (RCVs) in murine macrophages by confocal laser scanning microscopy, by transmission electron microscopy and by immunochemistry upon purification. We show that RCVs progress normally through the early stages of phagosome maturation acquiring PI(3)P, early endosome antigen‐1, and Rab5, and loosing all or much of them within minutes. Although mature RCVs possess the normally late endocytic markers, lysosome‐associated membrane proteins, lysobisphosphatidic acid and Rab7, they lack other hallmark features of late endocytic organelles such as possession of cathepsin D, acid β‐glucuronidase, proton‐pumping ATPase and the ability to fuse with prelabeled lysosomes. Bacterial strains possessing a virulence‐associated plasmid maintain a nonacidified compartment for 48 h, whereas isogenic strains lacking such plasmids acidify progressively. In summary, RCVs represent a novel phagosome maturation stage positioned after completion of the early endosome stage and before reaching a fully mature late endosome compartment. In addition, vacuole biogenesis can be influenced by bacterial plasmids.
Behavioral and neurochemical phenotyping of Homer1 mutant mice: possible relevance to schizophrenia
Authors: Szumlinski K. K. , Lominac K. D. , Kleschen M. J. , Oleson E. B. , Dehoff M. H. , Schwartz M. K. , Seeberg P. H. , Worley P. F. , Kalivas P. W.
Published: June 2005

Homer proteins are involved in the functional assembly of postsynaptic density proteins at glutamatergic synapses and are implicated in learning, memory and drug addiction. Here, we report that Homer1‐knockout (Homer1‐KO) mice exhibit behavioral and neurochemical abnormalities that are consistent with the animal models of schizophrenia. Relative to wild‐type mice, Homer1‐KO mice exhibited deficits in radial arm maze performance, impaired prepulse inhibition, enhanced ‘behavioral despair’, increased anxiety in a novel objects test, enhanced reactivity to novel environments, decreased instrumental responding for sucrose and enhanced MK‐801‐ and methamphetamine‐stimulated motor behavior. No‐net‐flux in vivo microdialysis revealed a decrease in extracellular glutamate content in the nucleus accumbens and an increase in the prefrontal cortex. Moreover, in Homer1‐KO mice, cocaine did not stimulate a rise in frontal cortex extracellular glutamate levels, suggesting hypofrontality. These behavioral and neurochemical data derived from Homer1 mutant mice are consistent with the recent association of schizophrenia with a single‐nucleotide polymorphism in the Homer1 gene and suggest that the regulation of extracellular levels of glutamate within limbo‐corticostriatal structures by Homer1 gene products may be involved in the pathogenesis of this neuropsychiatric disorder.
Dual‐peak dose measurement for radiochromic films by a newly developed spectral microdensitometer
Authors: Lee K. Y. , Fung K. K. L. , Kwok C. S.
Published: June 2005

Radiochromic film (RCF) dosimetry is usually based on densitometric methods which use an analyzing light source of a fixed or a broad spectrum of wavelengths. These methods have not exploited the sensitivity of the dose response of the RCF otherwise attainable by using a light source with wavelengths peaked at the two absorption peaks in the absorption spectrum of the RCF. A new algorithm of dual‐peak dose measurement for the RCF has been proposed in this paper to make use of these dual absorption peaks to achieve the maximum attainable sensitivity. This technique relies on the measurement of the transmittance of the RCF at the wavelength of the major and minor absorption peaks, respectively. The dual‐peak dose measurement is accomplished with the aid of a novel spectral microdensitometer developed in our Institute. The microdensitometer utilizes a monochromator to provide a light source of which the wavelength can be matched precisely to the wavelength of the absorption peaks of the RCF. The doses obtained at these wavelengths are fed into a weighted objective function and an optimum dose is searched by minimizing the objective function to give the best estimate of the dose deposited on the film. An initial test shows that there is a good agreement between the estimated and actual dose deposited; and the maximum discrepancy was found to be less than 1%.
Automatic detection of fiducial markers in fluoroscopy images for on‐line calibration
Authors: Smith Laurence , Pleasance Mike , Seeton Rosalyn , Archip Neculai , Rohling Robert
Published: June 2005

Calibrated C‐arm fluoroscopy is used for a variety of medical procedures where objects and anatomical structures need to be located in space. Calibration is often based on imaging a grid of fiducial markers and using the C‐arm image's geometrical measurements (radius and center) together with the positions of the markers. An on‐line technique is developed to automatically locate the fiducial markers and validated on 97 images. The success rate of the detection algorithm is 96.28% with an average error of and a standard deviation of .
Performance of a static‐anode/flat‐panel x‐ray fluoroscopy system in a diagnostic strength magnetic field: A truly hybrid x‐ray/MR imaging system
Authors: Fahrig R. , Wen Z. , Ganguly A. , DeCrescenzo G. , Rowlands J. A. , Stevens G. M. , Saunders R. F. , Pelc N. J.
Published: June 2005

Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo™ flat panel, custom Brand x‐ray static anode x‐ray tube, GE Lunar high‐frequency power supply and Signa SP™) provides both x‐ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x‐ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted‐edge modulation transfer function (MTF) and when placed at zero field and at . Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and . The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x‐ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x‐ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that electronics are robust against magnetic fields. Detailed knowledge of the x‐ray system installation is required to provide estimates of system operation.
SU‐CC‐J‐6C‐10: A Model for Technique Optimization of Dual Energy X‐Ray Imaging
Authors: Wheeldon S , Jabri K , Sabol J
Published: June 2005

Purpose: With increased clinical acceptance of dual‐energy radiography, there is rising interest in the application of dual‐energy techniques to other clinical problems. This paper describes the creation and experimental validation of a polyenergetic signal‐propagation model for technique optimization of new dual‐energy applications. The utility of this model is demonstrated with phantom verification of technique optimization of intravenous urography (IVU). Method and Materials: The model is composed of a spectral signal propagation component and an image‐processing module. The spectral propagation component accepts detector specifications, spectra, phantom, and imaging geometry as inputs, and outputs detector counts and estimated noise. The image‐processing module performs the dual‐energy logarithmic subtraction and returns statistics such as contrast and CNR that can be evaluated in conjunction with Monte Carlo calculations of dose. The technique is then optimized and correlated to data from phantom images. Hypotheses were investigated and model results compared with results from phantoms imaged in the laboratory. For IVU optimization, a phantom of polymethylmethacrelate and aluminum, and iodinated contrast agent filled tubes was imaged. Model and laboratory results were compared by dose, clinical suitability, and system limitations to yield optimized technique recommendations. Results: The model results accurately describe the images obtained in a low scatter environment. IVU‐optimized dual‐energy techniques differ from chest, and enable improved CNR over standard techniques without significant increases in dose, and with minimal degradation in the accompanying standard image. Alternatively, techniques without an accompanying standard image offer significantly lower dose and higher CNR. Conclusion: We have developed a model to predict optimized dual‐energy acquisition techniques. Its utility has been demonstrated for IVU. For this application, model and phantom results indicate that significant improvements in CNR can be obtained without significant increases in dose compared to conventional techniques. Conflict of Interest: All authors are employed by GE Healthcare.
SU‐DD‐A2‐01: Activation of Metallic Prostheses in Patients Undergoing Fast Neutron Therapy
Authors: Kouskoulas T , Yudelev M
Published: June 2005

Purpose: To quantify the induced activity and estimate the tissue dose from metallic prostheses in patients undergoing fast neutron therapy. Method and Materials: Three metal samples were tested, each having the dimensions of 5 × 5 × 0.5 cm3. The metals were composed of alloys that have been used in prosthetic hip implants: cobalt‐chromium, titanium‐aluminum‐vanadium, and stainless steel. The samples were irradiated with fast neutrons produced by d(48.5) + Be reaction in a superconducting medical cyclotron. The samples were placed in a tissue‐equivalent phantom and irradiated in a 10 × 10 cm2 field to a total dose of 9 Gy in 9 × 1 Gy daily fractions. Following each fraction, the sample was measured using a high‐purity germanium gamma‐ray detector. Spectra were taken at the following intervals: 1 minute, 1 hour, 2 hours, 3 hours, and approximately 24 hours after irradiation. Results: Activity 1 minute after irradiation averaged 5.4 mCi for CoCr, 4.9 mCi for Steel, and 9.3 mCi for TiVAl. Although the TiVAl sample had the highest initial activity, within 3 hours it had decayed the most. TiVAl also had the lowest activity 14 days after the last fraction. For a given dose, activities varied only slightly from day to day. An increase in dose delivered yielded an increase in induced activity. Conclusion: It appears that the TiVAl alloy would be the safest prosthetic material for patients undergoing fast neutron therapy, because of its fast decay rate. The presence of Co‐60 in the CoCr sample is undesirable because of its long half life. Exposure to surrounding tissue as a result of the activation was negligible compared to the levels of radiation caused by neutrons. The level of activation should be considered only if the device is to be removed from the patient after neutron therapy.
SU‐DD‐A1‐04: High‐Speed Scintillation Camera to Study IMRT Delivery
Authors: Ranade M , Lynch B , Li J , Dempsey J
Published: June 2005

Purpose: The aim of this study was to accurately obtain the beam shape and fluence of all segments delivered during IMRT. We have developed an EPID employing a fast scintillator and a high‐speed camera for this purpose. Method and Materials: A commercial high‐speed camera was combined with a Gd2O2S:Tb scintillator. The camera was equipped with an 8‐bit CMOS sensor, the pixel resolution was 0.635 mm, and the exposure time was 2.5 ms (to capture the scintillation pulses with a decay time of 0.550 ms but smaller than the 2.8 ms accelerator pulse period). The camera was synchronized to pulses from the accelerator pulse‐forming network and gated to capture every possible pulse emitted from the accelerator, at ∼360 pulses per second. An onboard 6 GB memory card allowed the capture of 60 s of delivery. A comparison of the MLC instruction files, log files, and camera data for a 42 segment IMRT beam delivery was performed. Results: The high speed camera allowed for capturing the delivered fluence without aliasing. Averaging 5 frames to 72 fps provided a signal‐to‐noise ratio that was sufficient to resolve leaf positions and segment fluence. The fluence from the log files and camera data agreed well except for the 1st segment where the log file appears to have missed the beginning of the delivery. The log files reported leaf motions at the end of 33 of the 42 segments. The camera measurements showed leaf motions in only 7 of the 42 segments. Conclusion: The high speed camera was able to resolve the IMRT beam output shape and fluence. Leaf motions were observed during beam‐on for step‐and‐shoot. We found that the log files do not accurately predict leaf motion. Finally, we note that the camera resolution is adequate to resolve dynamic delivery.
SU‐EE‐A2‐05: Accuracy in the Determination of Microcalcification Thickness in Digital Mammography
Authors: Brandan M‐E , Grabski V
Published: June 2005

Purpose: To study the factors which affect the accuracy of the microcalcification (MC) thickness determination in digital mammography, in particular, the contribution from scattered radiation. Method and Materials: The effect of scattered radiation on the accuracy of a MC thickness reconstruction has been studied using simulation. The GEANT4 code, assuming a scanning beam geometry, has been used to simulate photon transport through a tissue‐like flat phantom containing 0.2–1.0 mm thick cylindrical MC and a pixelized detector (100 microns side). The influence of detector resolution has been analyzed by the simulation of small spherical MC embedded into the phantom. Background has been determined by a fitting technique for the signal/background description, using a Gaussian‐like expression for the first, and a polynomial for the second. Measurements were carried out using a GE Senographe 2000D unit. Results: Our results indicate the possibility of reconstructing the MC thickness with accuracy of the order of 12.5%, including background, position and simulation uncertainties, when a 3 mm wide beam is used. The transversal size reconstruction for cylindrical MC having diameters larger than 1 mm, is of the order of 5%. Thickness reconstruction is found to be an alternative to signal to noise ratio for microcalcification detection. Conclusion: These simulations indicate that the thickness of dense objects larger than about 150 microns can be reconstructed using a digital mammography unit having 100 micron pixels and exposures equivalent to 1.5 mGy mean glandular dose.