bluuebunny/crossref_metadata_2025 huggingface dataset:
Swelling of cotton fibres in etylenediamine‐urea mixtures
Authors: Lokhande H. T. , Kulkarni M. P. , Shukla S. R.
Published: April 2003

Swelling and decrystallizing actions of ethylenediamine/urea/water and morpholine/urea/water mixtures on cotton cellulose have been investigated. Urea shows a positive synergistic influence on the swelling ability. With ethylenediamine/urea/water critical mixtures were obtained which are highly effective in swelling and decrystallizing cotton cellulose. The results are explained by ability of urea to modify the water structure as well as forming complexes with ethylenediamine and water molecules in definite proportions. A morpholine/urea/water mixture of a critical composition was also found to exhibit enhanced swelling of cotton fibres above the level of either morpholine or urea.
Randomized trial of pallidotomy versus medical therapy for Parkinson's disease
Authors: Vitek Jerrold L. , Bakay Roy A. E. , Freeman Alan , Evatt Marian , Green Joanne , McDonald William , Haber Michael , Barnhart Huiman , Wahlay Natalie , Triche Shirley , Mewes Klaus , Chockkan Vijay , Zhang Jian‐Yu , DeLong Mahlon R.
Published: April 2003

Thirty‐six patients with Parkinson's disease (PD) were randomized to either medical therapy (N = 18) or unilateral GPi pallidotomy (N = 18). The primary outcome variable was the change in total Unified Parkinson's Disease Rating Scale (UPDRS) score at 6 months. Secondary outcome variables included subscores and individual parkinsonian symptoms as determined from the UPDRS. At the six month follow‐up, patients receiving pallidotomy had a statistically significant reduction (32% decrease) in the total UPDRS score compared to those randomized to medical therapy (5% increase). Following surgery, patients' showed improvement in all the cardinal motor signs of PD including tremor, rigidity, bradykinesia, gait and balance. Drug‐induced dyskinesias were also markedly improved. Although the greatest improvement occurred on the side contralateral to the lesion, significant ipsilateral improvement was also observed for bradykinesia, rigidity and drug‐induced dyskinesias. A total of twenty patients have been followed for 2 years to assess the effect of time on clinical outcome. These patients have shown sustained improvement in the total UPDRS (p < 0.0001), “off” motor (p < 0.0001) and complications of therapy subscores (p < 0.0001). Sustained improvement was also seen for tremor, rigidity, bradykinesia, percent on time and drug‐induced dyskinesias. Ann Neurol 2003
Interleukin‐1β promotes oligodendrocyte death through glutamate excitotoxicity
Authors: Takahashi Jennifer L. , Giuliani Fabrizio , Power Christopher , Imai Yoshinori , Yong V. Wee
Published: April 2003

Glutamate excitotoxicity is implicated in the progressive loss of oligodendrocytes in multiple sclerosis, but how glutamate metabolism is dysregulated in the disease remains unclear. Because there is microglia activation in all stages of multiple sclerosis, we determined whether a microglia product, interleukin‐1β, could provide the mechanism for glutamate excitotoxicity. We found that whereas interleukin‐1β did not kill oligodendrocytes in pure culture, it produced apoptosis of oligodendrocytes in coculture with astrocytes and microglia. This requirement for a mixed glia environment suggests that interleukin‐1β impairs the well‐described glutamate‐buffering capacity of astrocytes. In support, antagonists at AMPA/kainate glutamate receptors, NBQX and CNQX, blocked the interleukin‐1β toxicity to oligodendrocytes. Another microglia/macrophage cytokine, tumor necrosis factor‐α, also evoked apoptosis of oligodendrocytes in a mixed glia environment in an NBQX‐blockable manner. These results provide a mechanistic link between the persistent and insidious microglia activation that is evident in all stages of multiple sclerosis, with the recent appreciation that glutamate excitotoxicity leads to the destruction of oligodendrocytes in the disease. Ann Neurol 2003;53:588–595
Bilateral frontoparietal polymicrogyria: Clinical and radiological features in 10 families with linkage to chromosome 16
Authors: Chang Bernard S. , Piao Xianhua , Bodell Adria , Basel‐Vanagaite Lina , Straussberg Rachel , Dobyns William B. , Qasrawi Bassam , Winter Robin M. , Innes A. Micheil , Voit Thomas , Grant P. Ellen , Barkovich A. James , Walsh Christopher A.
Published: April 2003

Polymicrogyria is a common malformation of cortical development characterized by an excessive number of small gyri and abnormal cortical lamination. Multiple syndromes of region‐specific bilateral symmetric polymicrogyria have been reported. We previously have described two families with bilateral frontoparietal polymicrogyria (BFPP), an autosomal recessive syndrome that we mapped to a locus on chromosome 16q12‐21. Here, we extend our observations to include 19 patients from 10 kindreds, all linked to the chromosome 16q locus, allowing us to define the clinical and radiological features of BFPP in detail. The syndrome is characterized by global developmental delay of at least moderate severity, seizures, dysconjugate gaze, and bilateral pyramidal and cerebellar signs. Magnetic resonance imaging demonstrated symmetric polymicrogyria affecting the frontoparietal regions most severely, as well as ventriculomegaly, bilateral white matter signal changes, and small brainstem and cerebellar structures. We have refined our genetic mapping and describe two apparent founder haplotypes, one of which is present in two families with BFPP and associated microcephaly. Because 11 of our patients initially were classified as having other malformations, the syndrome of BFPP appears to be more common than previously recognized and may be frequently misdiagnosed. Ann Neurol 2003
Endogenous estradiol and risk of dementia in women and men: The Rotterdam Study
Authors: Geerlings Mirjam I. , Launer Lenore J. , De Jong Frank H. , Ruitenberg Annemieke , Stijnen Theo , Van Swieten John C. , Hofman Albert , Witteman Jacqueline C. M. , Pols Huibert A. P. , Breteler Monique M. B.
Published: April 2003

We determined whether higher endogenous estradiol levels were associated with lower risk of dementia in older men and women not using hormonal replacement therapy, using a case‐cohort design within the Rotterdam Study, a population‐based follow‐up study on chronic diseases, including dementia, in 7,983 subjects aged 55 years or older, and ongoing since 1990. The analyses were based on a random subcohort of 508 women and 438 men, and on 76 women and 53 men with incident dementia. Cox proportional hazards models with robustly estimated standard errors showed that in women higher levels of total estradiol were associated with higher risk of dementia (age‐adjusted hazard ratio per standard deviation increase 1.38; 95% CI 1.04–1.84). Age‐adjusted HR's of Alzheimer's disease and vascular dementia associated with higher levels of total estradiol (per SD increase) were 1.24 (95% CI 0.87–1.76) and 2.19 (95% CI 1.22–3.92), respectively. Similar results were observed for bioavailable estradiol. Additional adjustments for potential confounders did not change the results substantially. In men, no clear association was observed between estradiol levels and risk of dementia or its subtypes. The findings do not support the hypothesis that higher levels of endogenous estradiol reduce risk of dementia, neither in women nor in men. Ann Neurol 2003
Tremor and ataxia in fragile X premutation carriers: Blinded videotape study
Authors: Berry‐Kravis Elizabeth , Lewin Foster , Wuu Joanne , Leehey Maureen , Hagerman Randi , Hagerman Paul , Goetz Christopher G.
Published: April 2003

Fragile X premutation carriers do not have typical fragile X syndrome (FXS) although late‐onset progressive action tremor and gait disorder with CNS atrophy was recently reported in male carriers. We compared tremor, gait disorder and parkinsonian signs in FXS premutation subjects (age 50 or more) and a similar control population, using a standardized videotaping protocol. Videotapes were rated using standard scales for tremor (CRST), ataxia (ICARS), and parkinsonian signs (UPDRS) by an investigator blinded to premutation status. Compared to all other groups pooled (n = 30), the male premutation carrier group (n = 7) had significantly higher scores on the CRST (p = 0.0008), ICARS (p = 0.001), and UPDRS (p = 0.0094). On the CRST, rest, postural and kinetic tremor scores were all higher in the male carriers. The elevated total UPDRS and ICARS scores mainly resulted from markedly higher scores for tremor and limb ataxia, respectively. The female carrier (n = 14) and control groups (n = 8) did not differ on any measure. The FMR1 premutation is associated with increased levels of CGG repeat‐containing FMR1 mRNA, which may predispose to these symptoms by interfering with nuclear mechanisms. Given the relatively high population frequency of the FMR1 premutation, this mutation may be a significant cause of late‐onset “idiopathic” progressive tremor. Ann Neurol 2003
Lineage pathway of human brain progenitor cells identified by JC virus susceptability
Authors: Messam Conrad A. , Hou Jean , Gronostajski Richard M. , Major Eugene O.
Published: April 2003

Multipotential human central nervous system progenitor cells, isolated from human fetal brain tissue by selective growth conditions, were cultured as undifferentiated, attached cell layers. Selective differentiation yielded highly purified populations of neurons or astrocytes. This report describes the novel use of this cell culture model to study cell type–specific recognition of a human neurotropic virus, JC virus. Infection by either JC virions or a plasmid encoding the JC genome demonstrated susceptibility in astrocytes and, to a lesser degree, progenitor cells, whereas neurons remained nonpermissive. JC virus susceptibility correlated with significantly higher expression of the NFI‐X transcription factor in astrocytes than in neurons. Furthermore, transfection of an NFI‐X expression vector into progenitor‐derived neuronal cells before infection resulted in viral protein production. These results indicate that susceptibility to JC virus infection occurs at the molecular level and also suggest that differential recognition of the viral promoter sequences can predict lineage pathways of multipotential progenitor cells in the human central nervous system. Ann Neurol 2003
Temporal processing of visuotactile and tactile stimuli in writer's cramp
Authors: Fiorio Mirta , Tinazzi Michele , Bertolasi Laura , Aglioti Salvatore M.
Published: April 2003

Neurophysiological studies in animals show that basal ganglia are involved not only in motor and nonmotor timing functions but also in integrating tactile and visual signals delivered in the peripersonal space. We tested temporal discrimination of cross‐modal and unimodal stimuli in 13 controls and 14 patients with writer's cramp, a disorder supposedly linked to dysfunction of basal ganglia. Subjects were asked to discriminate whether pairs of visual, tactile, or visuotactile stimuli were simultaneous or sequential (temporal discrimination threshold) and which stimulus preceded the other (temporal order judgment). Patients were impaired in temporal processing of tactile and cross‐modal stimuli. A significant positive correlation between temporal deficits and the severity of disability was detected for both affected and unaffected sides. Findings suggest that multimodal and not only modality‐specific temporal processing is defective in focal hand dystonia. Deficits of temporal processing of stimuli delivered to the unaffected side may represent a behavioral index of the susceptibility to develop dystonia and thus have remarkable practical and theoretical implications. Ann Neurol 2003
Decoupling of autonomic and cognitive emotional reactions after cerebellar stroke
Authors: Annoni Jean‐Marie , Ptak Radek , Caldara‐Schnetzer Anne‐Sarah , Khateb Asaid , Pollermann Branka Zei
Published: April 2003

Emotional blunting can be found after cerebellar lesions. However, the mechanism of such a modification is not clear. We present a patient with emotional flattening and increased risk taking after left cerebellar infarct who had an impaired autonomic reactivity to negative as compared with positive reinforcement. This impairment was demonstrated by the patient's undifferentiated skin conductance responses to negative and positive reinforcement, whereas controls produced larger skin conductance responses after negative feedback. The cooccurrence of emotional flattening and undifferentiated autonomic reactions to positively and negatively valenced stimuli strengthens the role of the cerebellum in the modulation of the autonomic responses. Ann Neurol 2003;53:654–658
Polymicrogyria and absence of pineal gland due to PAX6 mutation
Authors: Mitchell Tejal N. , Free Samantha L. , Williamson Kathleen A. , Stevens John M. , Churchill Amanda J. , Hanson Isabel M. , Shorvon Simon D. , Moore Anthony T. , van Heyningen Veronica , Sisodiya Sanjay M.
Published: April 2003

Identification of genes involved in human cerebral development is important for our understanding of disorders with potential neurodevelopmental causes such as epilepsy and learning disability. Murine models suggest that PAX6 plays a key role in human brain development. With magnetic resonance imaging in 24 humans heterozygous for defined PAX6 mutations, we demonstrated widespread structural abnormalities including absence of the pineal gland and unilateral polymicrogyria. Ann Neurol 2003;53:658–663
Weight loss in Parkinson's disease
Authors: Chen Honglei , Zhang Shumin M. , Hernán Miguel A. , Willett Walter C. , Ascherio Alberto
Published: April 2003

We prospectively examined the changes of body weight among 468 individuals with Parkinson's disease (PD) before and after the diagnosis. The average weight of PD patients was stable until shortly before the diagnosis (p for trend = 0.2) and then declined (p for trend < 0.0001). Interestingly, PD patients tended to increase their energy intakes as their weights decreased (p for trend < 0.002). In conclusion, weight loss in PD patients appears to be a continuous process that starts several years before the diagnosis and is not caused by reduced energy intake. Ann Neurol 2003;53:676–679
Functional magnetic resonance imaging of human absence seizures
Authors: Salek‐Haddadi Afraim , Lemieux Louis , Merschhemke Martin , Friston Karl J. , Duncan John S. , Fish David R.
Published: April 2003

We studied a patient with idiopathic generalized epilepsy and frequent absences, using electroencephalogram‐correlated functional magnetic resonance imaging. Four prolonged runs of generalized spike‐wave discharge occurred during a 35‐minute experiment. Time‐locked activation was observed bilaterally within the thalami in conjunction with widespread but symmetrical cortical deactivation with a frontal maximum. We demonstrate the reciprocal participation of focal thalamic and widespread cortical networks during human absence seizures and suggest reductions in cortical blood flow, in response to synchronized electroencephalogram activity. Ann Neurol 2003;53:663–667
Reconstructing cetacean brain evolution using computed tomography
Authors: Marino Lori , Uhen Mark D. , Pyenson Nicholas D. , Frohlich Bruno
Published: April 2003

Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This approach will provide new insights into the little‐known evolutionary history of cetacean brain evolution. Anat Rec (Part B: New Anat) 272B:107–117, 2003. © 2003 Wiley‐Liss, Inc.
Development of multimedia learning modules for teaching human anatomy: Application to osteology and functional anatomy
Authors: Van Sint Jan Serge , Crudele Michele , Gashegu Julien , Feipel Veronique , Poulet Pascal , Salvia Patrick , Hilal Isam , Sholukha Victor , Louryan Stephane , Rooze Marcel
Published: April 2003

Computer‐assisted learning (CAL) is growing quickly within academic programs. Although the anatomical commercial packages that are available for this learning have attractive advantages, they also have drawbacks: they are frequently not in the local language of the students, they do not perfectly answer the needs of the local academic program, and their cost is frequently more than students can afford. This study describes a relatively inexpensive method to create CAL tutorials, whose content can be fully customized to local academic needs in terms of both program and language. The study describes its use in creating multimedia learning modules (MLMs) about Osteology and joint kinematics. The pedagogical content in these modules was collected from objective experiments to give students the opportunity to access new scientific knowledge during their education. It can be replaced, as desired, by almost any content due to the flexibility of the production method. Each MLM consists of two complementary subelements: a multimedia theoretical lecture and a three‐dimensional interactive laboratory. Such MLMs are in use at both the University of Brussels (ULB) and the National University of Rwanda (NUR). The development of this work was part of the VAKHUM project, and the pedagogical validation is currently being performed as part of the MULTIMOD project. Anat Rec (Part B: New Anat) 272B:98–106, 2003. © 2003 Wiley‐Liss, Inc.
Maximum likelihood parallel factor analysis (MLPARAFAC)
Authors: Vega‐Montoto Lorenzo , Wentzell Peter D.
Published: April 2003

Algorithms for carrying out maximum likelihood parallel factor analysis (MLPARAFAC) for three‐way data are described. These algorithms are based on the principle of alternating least squares, but differ from conventional PARAFAC algorithms in that they incorporate measurement error information into the trilinear decomposition. This information is represented in the form of an error covariance matrix. Four algorithms are discussed for dealing with different error structures in the three‐way array. The simplest of these treats measurements with non‐uniform measurement noise which is uncorrelated. The most general algorithm can analyze data with any type of noise correlation structure. The other two algorithms are simplifications of the general algorithm which can be applied with greater efficiency to cases where the noise is correlated only along one mode of the three‐way array. Simulation studies carried out under a variety of measurement error conditions were used for statistical validation of the maximum likelihood properties of the algorithms. The MLPARAFAC methods are also shown to produce more accurate results than PARAFAC under a variety of conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Practical aspects of PARAFAC modeling of fluorescence excitation‐emission data
Authors: Andersen C. M. , Bro R.
Published: April 2003

This paper presents a dedicated investigation and practical description of how to apply PARAFAC modeling to complicated fluorescence excitation–emission measurements. The steps involved in finding the optimal PARAFAC model are described in detail based on the characteristics of fluorescence data. These steps include choosing the right number of components, handling problems with missing values and scatter, detecting variables influenced by noise and identifying outliers. Various validation methods are applied in order to ensure that the optimal model has been found and several common data‐specific problems and their solutions are explained. Finally, interpretations of the specific models are given. The paper can be used as a tutorial for investigating fluorescence landscapes with multi‐way analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Unsupervised segmentation of predefined shapes in multivariate images
Authors: Noordam J. C. , van den Broek W. H. A. M. , Buydens L. M. C.
Published: April 2003

Fuzzy C‐means (FCM) is an unsupervised clustering technique that is often used for the unsupervised segmentation of multivariate images. In traditional FCM the clustering is based on spectral information only and the geometrical relationship between neighbouring pixels is not used in the clustering procedure. In this paper, the spatially guided FCM (SG‐FCM) algorithm is presented which segments multivariate images by incorporating both spatial and spectral information. Spatial information is described by a geometrical shape description and can vary from a local neighbourhood to a more extended shape model such as Hough circle detection. A modified FCM objective function uses the spatial information as described by the shape model. This results in a segmented image in which the construction of the cluster prototypes is influenced by spatial information. The performance of SG‐FCM is compared with both FCM and the sequence of FCM and a majority filter. The SG‐FCM segmented image shows more homogeneous regions and less spurious pixels. Copyright © 2003 John Wiley & Sons, Ltd.
Secured PCR (sPCR) for detection and correction of PCR calibration model failures induced by uncalibrated spectral features
Authors: Vogt F. , Mizaikoff B.
Published: April 2003

Many spectroscopic monitoring techniques make use of chemometric algorithms such as principal component regression (PCR) for calibration and evaluation of optical spectra. However, standard techniques of chemometric calibration and evaluation suffer from uncalibrated spectral features which are contained in measured spectra but were not considered during the initial calibration. For two main reasons such uncalibrated spectral features have to be detected and corrected: (a) if unknown spectral features appear after calibration major errors of concentration prediction are encountered and (b) the detection of uncalibrated spectral features enables recognition and handling of failures occurring in chemical processes. Hence detection, correction and characterization of uncalibrated absorption features are of great importance in on‐line spectroscopy. A novel approach is proposed here for this purpose. This algorithm performs a qualitative data analysis for detecting and correcting such uncalibrated spectral features. Following this qualitative data analysis and if necessary correction, a conventional PCR is used for calculating the concentration of the calibrated analytes. Both steps together set up a so‐called secured PCR (sPCR). In the undisturbed case this sPCR algorithm is demonstrated to provide equivalent results as conventional PCR and to be superior in evaluating disturbed spectra. For testing purposes simulated spectra sets are used since the disturbance is known and the determined results can be validated with respect to the magnitude of the true disturbance. The errors averaged over 1000 disturbed test samples could be decreased up to 71% by sPCR compared with conventional PCR. In up to 94% of the test samples more accurate concentration values were obtained. The novel sPCR algorithm was also applied to experimental spectra measured with mid‐infrared attenuated total reflection spectroscopy considering chlorinated hydrocarbons dissolved in water. sPCR is capable to extract uncalibrated features from these experimental data and to improve the concentration results. Copyright © 2003 John Wiley & Sons, Ltd.
Robust Bayesian estimation of the hemodynamic response function in event‐related BOLD fMRI using basic physiological information
Authors: Marrelec Guillaume , Benali Habib , Ciuciu Philippe , Pélégrini‐Issac Mélanie , Poline Jean‐Baptiste
Published: April 2003

In BOLD fMRI data analysis, robust and accurate estimation of the Hemodynamic Response Function (HRF) is still under investigation. Parametric methods assume the shape of the HRF to be known and constant throughout the brain, whereas non‐parametric methods mostly rely on artificially increasing the signal‐to‐noise ratio. We extend and develop a previously proposed method that makes use of basic yet relevant temporal information about the underlying physiological process of the brain BOLD response in order to infer the HRF in a Bayesian framework. A general hypothesis test is also proposed, allowing to take advantage of the knowledge gained regarding the HRF to perform activation detection. The performances of the method are then evaluated by simulation. Great improvement is shown compared to the Maximum‐Likelihood estimate in terms of estimation error, variance, and bias. Robustness of the estimators with regard to the actual noise structure or level, as well as the stimulus sequence, is also proven. Lastly, fMRI data with an event‐related paradigm are analyzed. As suspected, the regions selected from highly discriminating activation maps resulting from the method exhibit a certain inter‐regional homogeneity in term of HRF shape, as well as noticeable inter‐regional differences. Hum. Brain Mapping 19:1–17, 2003. © 2003 Wiley‐Liss, Inc.
Demand on verbal working memory delays haemodynamic response in the inferior prefrontal cortex
Authors: Thierry Guillaume , Ibarrola Danielle , Démonet Jean‐François , Cardebat Dominique
Published: April 2003

Event‐related functional magnetic resonance imaging was used to test the involvement of the inferior prefrontal cortex in verbal working memory. Pairs of French nouns were presented to ten native French speakers who had to make semantic or grammatical gender decisions. Verbal working memory involvement was manipulated by making the categorization of the second noun optional. Decisions could be made after processing the first noun only (RELEASE condition) or after processing the two nouns (HOLD condition). Reaction times suggested faster processing for gender than for semantic category in RELEASE. Despite the absence of anatomical difference across tasks and conditions in the wide activated network, the haemodynamic response peak latencies of the inferior prefrontal cortex were significantly delayed in HOLD versus RELEASE while no such peak delay was observed in the superior temporal gyrus. Interestingly, this pattern did not interact with language tasks. This study shows that cognitive manipulation can influence haemodynamic time‐course and suggests that the main cognitive process determining inferior prefrontal activation is verbal working memory rather than specific linguistic processes such as grammatical or semantic analysis. Hum. Brain Mapping 19:37–46, 2003. © 2003 Wiley‐Liss, Inc.
Brain activations during motor imagery of locomotor‐related tasks: A PET study
Authors: Malouin Francine , Richards Carol L. , Jackson Philip L. , Dumas Francine , Doyon Julien
Published: April 2003

Positron emission tomography (PET) was used to study the involvement of supraspinal structures in human locomotion. Six right‐handed adults were scanned in four conditions while imagining locomotor‐related tasks in the first person perspective: Standing (S), Initiating gait (IG), Walking (W) and Walking with obstacles (WO). When these conditions were compared to a rest (control) condition to identify the neural structures involved in the imagination of locomotor‐related tasks, the results revealed a common pattern of activations, which included the dorsal premotor cortex and precuneus bilaterally, the left dorsolateral prefrontal cortex, the left inferior parietal lobule, and the right posterior cingulate cortex. Additional areas involving the pre‐supplementary motor area (pre‐SMA), the precentral gyrus, were activated during conditions that required the imagery of locomotor movements. Further subtractions between the different locomotor conditions were then carried out to determine the cerebral regions associated with the simulation of increasingly complex locomotor functions. These analyses revealed increases in rCBF activity in the left cuneus and left caudate when the W condition was compared to the IG condition, suggesting that the basal ganglia plays a role in locomotor movements that are automatic in nature. Finally, subtraction of the W from the WO condition yielded increases in activity in the precuneus bilaterally, the left SMA, the right parietal inferior cortex and the left parahippocampal gyrus. Altogether, the present findings suggest that higher brain centers become progressively engaged when demands of locomotor tasks require increasing cognitive and sensory information processing. Hum. Brain Mapping 19:47–62, 2003. © 2003 Wiley‐Liss, Inc.
Cerebral information transfer during word processing: Where and when does it occur and how fast is it?
Authors: Schack Baerbel , Weiss Sabine , Rappelsberger Peter
Published: April 2003

Different regions of the brain have to interact to perform language processing. Such neural integration processes can be studied by measuring synchronization of oscillations. Coherence is the best known algorithm to study synchronization between two sites of the cortex with regard to selected oscillation frequencies. Phase coherence quantifies phase synchronization, in particular. In addition, cross phase (or simply phase) gives information about the direction and speed of the spread of oscillations. We use a new method to study short‐time phases between different sites of the cortex in order to explore transient neural networks during word processing. Particularly, processing of abstract and concrete nouns was investigated by dynamic phase analysis of the alpha1 frequency band (8–10 Hz). Abstract and concrete nouns turned out to induce different dynamic networks of information transfer. Whereas processing of concrete nouns excites a widespread network for about 800 msec, the interhemispheric interactions during abstract noun processing are restricted to 300–500 msec after word presentation. Further, the direction of cerebral information transfer differs for the two word categories. Additionally, it could be shown that the propagation speed of information is slower for concrete nouns than for abstract nouns. Hum. Brain Mapping 19:18–36, 2003. © 2003 Wiley‐Liss, Inc.
From Here to Seniority: The Effect of Experience and Job Tenure on Faculty Salaries
Authors: Barbezat Debra A.
Published: April 2003

The general impressions of salary compression and a negative return on seniority for faculty are overstated and depend greatly on the specification of the salary model used by researchers.
Addressing Gender Equity in Nonfaculty Salaries
Authors: Toutkoushian Robert K.
Published: April 2003

This chapter illustrates ways in which gender‐ and race‐equity studies can be performed of nonfaculty employees such as professional or administrative staff in higher education.
Conducting a Salary‐Equity Study: A Consultant's View
Authors: McLaughlin Gerald W. , McLaughlin Josetta S.
Published: April 2003

A case‐study approach illustrates the various statistical and political issues that analysts often encounter when conducting a salary‐equity study for a single institution.
Incorporation of calcium phosphate enhances recombinant adeno‐associated virus‐mediated gene therapy in diabetic mice
Authors: Yang Ya‐Wun , Chao Chih‐Kai
Published: April 2003

Background

Increased efficiency of transgene expression is desired for virus‐mediated gene delivery. In the present study, we examined the effect of calcium phosphate (CaPi) on recombinant adeno‐associated virus (rAAV)‐mediated insulin therapy in diabetic animals.

Methods

The rAAV vector, rAAV.PEPCK.Ins.EGFP, containing the human insulin gene under control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter and the enhanced green fluorescence protein (EGFP) gene driven by the cytomegalovirus (CMV) IE promoter, was employed in this study. C57BL/6J mice were made diabetic with streptozotocin (STZ), followed by injection into the livers with either rAAV alone, or noncovalent complexes with calcium phosphate. Body weight and blood glucose levels of the animals were routinely monitored after 6 h fasting. Secretion of human insulin in the rAAV‐transduced animals was determined by radioimmunoassay (RIA). Expression of human insulin in the livers of the animals was detected by immunohistochemical staining.

Results

Compared with the STZ‐treated control mice, administration of rAAV containing the human insulin gene significantly decreased blood glucose levels and maintained body weight of the diabetic animals. Complexation of rAAV with calcium phosphate enhanced the hypoglycemic effect of rAAV‐mediated gene transfer. Results obtained from both RIA and immunohistochemical staining demonstrated that incorporation of calcium phosphate enhanced rAAV‐mediated gene transfer in vivo, leading to higher expression and secretion of human insulin.

Conclusions

Administration of rAAV harboring the human insulin gene into livers of the STZ‐diabetic mice improved blood glucose levels, maintained body weight of the diabetic animals, and resulted in human insulin secretion. Complexation of rAAV with calcium phosphate significantly potentiated the efficiency of rAAV‐mediated diabetic gene therapy. Copyright © 2002 John Wiley & Sons, Ltd.
Multiple muscles in the AMD quail can be “cross‐corrected” of pathologic glycogen accumulation after intravenous injection of an [E1‐, polymerase‐] adenovirus vector encoding human acid‐α‐glucosidase
Authors: McVie‐Wylie A. J. , Ding E. Y. , Lawson T. , Serra D. , Migone F. K. , Pressley D. , Mizutani M. , Kikuchi T. , Chen Y. T. , Amalfitano A.
Published: April 2003

Background

Previously, in murine models of acid maltase deficiency (AMD), we demonstrated that intravenous administration of an improved adenovirus (Ad) vector encoding human acid alpha glucosidase (hGAA) resulted in liver transduction, followed by high‐level hepatocyte‐mediated secretion of hGAA into the plasma space. The hGAA secreted by the liver was taken up and targeted to muscle cell lysosomes. The levels of hGAA achieved by this approach resulted in clearance of lysosomal glycogen accumulations; in some muscle tissues the effect was prolonged (>6 months). We next wished to demonstrate whether this approach could be generalized across divergent species. To accomplish this goal, we determined whether a similar approach would also result in efficacy, but in a quail model of AMD.

Methods

An [E1‐, E2b‐]Ad vector encoding hGAA was intravenously injected into AMD quails. At several time points thereafter, plasma, liver, and multiple muscle tissues were assayed for evidence of hGAA gene expression, liver‐mediated hGAA secretion, uptake of hGAA by skeletal muscles, and evidence of glycogen correction in AMD skeletal muscles. These results were compared with those obtained from mock‐injected AMD or wild‐type quails.

Results

Intravenous [E1‐, E2b‐]Ad/hGAA vector injection resulted in high‐level liver transduction and hepatic secretion of precursor forms of hGAA. The hepatically secreted hGAA was found to not only be efficiently taken up by cardiac and skeletal muscles, but was also proteolytically cleaved and processed equivalently to the quail‐GAA protein detected in wild‐type quails. The observations suggest that the signals regulating muscle cell uptake (but not proteolytic cleavage) of lysosomal enzymes are conserved and recognized across divergent species of vertebrates. Importantly, once localized to skeletal muscle lysosomes, the hGAA was able to effectively clear the glycogen accumulations present in AMD quail muscles.

Conclusions

Adenovirus‐mediated transduction of the hGAA gene, followed by hepatic secretion, uptake, and cross‐correction of the pathologic glycogen accumulation noted in multiple muscles of both the AMD mouse and AMD quail, adds support to the notion that gene transfer strategies (Ad‐mediated or other agents) targeting liver tissues with the hGAA gene are likely to be highly efficacious in humans affected by AMD. Copyright © 2002 John Wiley & Sons, Ltd.
Drug‐selected co‐expression of P‐glycoprotein and gp91 in vivo from an MDR1‐bicistronic retrovirus vector Ha‐MDR‐IRES‐gp91
Authors: Sugimoto Yoshikazu , Tsukahara Satomi , Sato Shigeo , Suzuki Mutsumi , Nunoi Hiroyuki , Malech Harry L. , Gottesman Michael M. , Tsuruo Takashi
Published: April 2003

Background

Retroviral transduction of human hematopoietic stem cells is an attractive strategy in gene therapy; however, transduction efficiency and duration of transgene expression may not be satisfactory in current protocols. Co‐expression of a human multidrug resistance gene (MDR1) with a therapeutic gene affords selectable growth advantage to genetically modified cells.

Methods

A bicistronic retrovirus vector, Ha‐MDR‐IRES‐gp91, was constructed for the co‐expression of MDR1 and gp91, a gene responsible for X‐linked chronic granulomatous disease (X‐CGD). Drug‐selected co‐expression of P‐glycoprotein and gp91 was evaluated in transduced cells.

Results

Epstein‐Barr virus‐transformed B cells from X‐CGD patients transduced with Ha‐MDR‐IRES‐gp91 co‐expressed human P‐glycoprotein and gp91, and acquired superoxide‐generating activity. Human CD34‐positive cells from an X‐CGD patient were transduced with Ha‐MDR‐IRES‐gp91 and subsequently treated with 2 ng/ml vincristine. After 13 days, 20% of Ha‐MDR‐IRES‐gp91‐transduced cells were P‐glycoprotein‐ and gp91‐positive by FACS analysis. The superoxide‐generating activity of the transduced population was 27% of that of normal cells. Mice transplanted with Ha‐MDR‐IRES‐gp91‐transduced bone marrow cells showed co‐expression of P‐glycoprotein and gp91 in peripheral blood mononuclear cells. By administering paclitaxel, the proportions of P‐glycoprotein‐ and gp91‐positive cells were increased in all the four mice examined. When mice transplanted with Ha‐MDR‐IRES‐gp91‐transduced cells were repeatedly administered paclitaxel, the ratios of P‐glycoprotein‐ and gp91‐positive cells were maintained for over 1 year.

Conclusions

These results suggest that MDR1‐bicistronic vectors may be useful to select the transduced hematopoietic cells in vivo. This may lead to the sustained expression of transgenes in the blood cells of patients treated with stem cell gene therapy. Copyright © 2003 John Wiley & Sons, Ltd.
Induction of T cell tolerance to a protein expressed in the cytoplasm through retroviral‐mediated gene transfer
Authors: Tian Chaorui , Bagley Jessamyn , Kaye Joel , Iacomini John
Published: April 2003

Background

Host immune responses to foreign gene products have been shown to lead to the elimination of genetically modified cells, and are a major barrier to successful therapeutic gene therapy. We have shown that immunological tolerance to retrovirally transduced cell surface proteins can be induced by expressing the gene encoding these products in bone marrow derived cells. Here, we investigate if expression of foreign gene products in bone marrow derived cells can be used to induce tolerance to cytoplasmic proteins.

Methods

Balb/c mice were reconstituted with syngeneic bone marrow cells transduced with retrovirus carrying the gene encoding enhanced green fluorescent protein (eGFP), or mock‐transduced bone marrow cells. After reconstitution, mice were immunized with cells expressing eGFP, and T cells were tested for the ability to kill eGFP‐expressing targets in in vitro cytotoxic T lymphocyte (CTL) assays.

Results

T cells from Balb/c mice reconstituted with mock‐transduced bone marrow were able to kill target cells expressing eGFP. In contrast, T cells from mice reconstituted with eGFP‐transduced bone marrow were unable to kill targets expressing eGFP. In addition, we observed that T cell responses to eGFP in C57BL/6 mice were minimal even under highly immunogenic conditions.

Conclusions

These data suggest that expression of foreign gene products in bone marrow derived cells is capable of inducing T cell tolerance to proteins expressed exclusively in the cytoplasm. Copyright © 2003 John Wiley & Sons, Ltd.
Concurrent delivery of GM‐CSF and endostatin genes by a single adenoviral vector provides a synergistic effect on the treatment of orthotopic liver tumors
Authors: Tai Kuo‐Feng , Chen Pei‐Jer , Chen Ding‐Shinn , Hwang Lih‐Hwa
Published: April 2003

Background

The immune resistance of large tumors represents a major problem for cancer immunotherapy, whereas the need for repeated injections of high doses of recombinant anti‐angiogenic proteins represents a similar problem for anti‐angiogenic therapy. To test whether antitumor activity could be increased by combining the above two mechanisms, this study examined the therapeutic effect of combination gene therapy using a murine granulocyte‐macrophage colony‐stimulating factor (mGM‐CSF) gene and a human endostatin (hED) gene on a rat orthotopic liver tumor model.

Methods

An adenoviral vector was constructed that simultaneously carried two transcriptional cassettes, for the expression of mGM‐CSF and hED, respectively, or that carried a single cassette of either gene. The adenoviruses were intratumorally administered to 3‐day‐old or 7‐day‐old tumors. Moreover, the antitumor effects of the combination therapy and monotherapy were assessed and compared.

Results

The double‐gene‐containing adenoviral vector expressed transgenes as efficiently as the single‐gene‐containing vector. Moreover, the adenovirally expressed endostatin was biologically active, as demonstrated in vitro and in vivo. Results from animal experiments demonstrated a synergistic antitumor effect induced by the combined mGM‐CSF and hED therapy. The combination of hED with mGM‐CSF enhanced tumor‐specific CTL activity, but did not interfere with the infiltration of cellular effectors in the tumor regions. The blood vessel density of the liver tumors markedly reduced as a result of hED expression in both monotherapy and combination therapy. Furthermore, combination therapy significantly increased the number of apoptotic cells in the tumor regions.

Conclusions

The experimental results suggest that the combined gene therapy against tumor cells and the tumor vascular system using antitumor immune mechanisms and anti‐angiogenic mechanisms holds promise as a strategy for treating cancers. Copyright © 2003 John Wiley & Sons, Ltd.
Antioxidant activity of ginger extract in sunflower oil
Authors: Zia‐ur‐Rehman  , Salariya A M , Habib Farzana
Published: April 2003

The antioxidant activity of dichloromethane extract from ginger was evaluated during 6 months of storage of refined sunflower oil at 25 and 45 °C. Free fatty acid (FFA) content, peroxide value (POV) and iodine value (IV) were used as criteria to assess ginger extract as an antioxidant. After 6 months of storage at 45 °C, sunflower oil containing 1600 and 2400 ppm ginger extract showed lower FFA contents (0.083 and 0.080%) and POVs (24.5 and 24.0 meq kg−1) than the control sample (FFA contents 0.380%, POV 198.0 meq kg−1). Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) showed FFA contents of 0.089 and 0.072% and POVs of 26.5 and 24.7 meq kg−1 respectively after 6 months of storage at 45 °C. Similarly, after 6 months of storage at 45 °C, IVs of sunflower oil containing 1600 and 2400 ppm ginger extract were 80 and 92 respectively, higher than that of the control sample (53). However, IVs of sunflower oil treated with 200 ppm BHA and BHT were 94 and 96 respectively after 6 months of storage at 45 °C. These results illustrate that ginger extract at various concentrations exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). Ginger extract also showed good thermal stability and exhibited 85.2% inhibition of peroxidation of linoleic acid when heated at 185 °C for 120 min. Therefore the use of ginger extract in foods is recommended as a natural antioxidant to suppress lipid oxidation.

© 2003 Society of Chemical Industry
Effect of endo‐xylanase‐containing enzyme preparations and laccase on the solubility of rye bran arabinoxylan
Authors: Andersson Roger , Eliasson Christina , Selenare Mangala , Kamal‐Eldin Afaf , Åman Per
Published: April 2003

Three commercial enzyme preparations with endo‐xylanase activity, namely Bio‐Feed Wheat, Bio‐Feed Plus and Grindamyl H 640, and laccase have been tested for their effects on the solubilisation of arabinoxylan (AX) in rye bran or autoclaved rye bran. Autoclaving efficiently increased the availability of AX for enzymatic degradation. Both Bio‐Feed Wheat (a monocomponent enzyme) and Bio‐Feed Plus (a multicomponent preparation with different enzymatic activities) efficiently degraded the autoclaved rye bran AX into lower‐molecular‐weight fragments. As much as 70% of the xylose residues and 58% of the arabinose residues in the autoclaved bran were soluble after treatment with Bio‐Feed Plus; the weight—average molecular weight of the detectable portion of these soluble polymers was 104 000 Da. Grindamyl H 640 solubilised only a small fraction of the AX in autoclaved rye bran; the molecular weight of these soluble fragments was higher than that of those released by the Bio‐Feed xylanases. Addition of laccase during treatment with Bio‐Feed Wheat or Grindamyl H 640 decreased the yield of water‐soluble AX.

© 2003 Society of Chemical Industry
Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure
Authors: Sajnín C , Gamba G , Gerschenson L N , Rojas A M
Published: April 2003

Textural, histological and biochemical characteristics of cucumber (Cucumis sativus L) under different tissue turgor pressures were studied after equilibration of mesocarp tissue cylinders in various polyethylene glycol 400 (PEG) solutions. Tissue swelling was observed for all hypotonic solutions. Cell membrane vitality was detected in all cucumber tissues where significant values of initial firmness (fi) and residual relaxation force (FR) were found. Good turgor status was also associated with higher values of these parameters, observing higher values of the textural parameters for higher turgor. Cell wall integrity was observed through Calcofluor fluorescence assay in tissue equilibrated in hypotonic, isotonic and hypertonic solutions, although a lower fluorescence intensity was observed in tissue equilibrated with 0 mol m−3 PEG solution, probably owing to some cell bursting. Calcium bridges between pectic polymers were proven to be responsible for cell–cell adhesion and tissue integrity of cucumber mesocarp tissue. Compression curves obtained for raw tissue showed a stage of fracture, and its loss after immersion might be attributed to cell–cell adhesion weakness due to immersion in calcium‐free PEG solutions. Peroxidase and polygalacturonase increased after cucumber equilibration in the solutions, probably expressing tissue injury. Cucumber textural behaviour was very much affected by immersion in calcium‐free solutions, determining the loss of fracture stage and a great influence of turgor pressure on the textural response of soaked tissue.

© 2003 Society of Chemical Industry
Dehydration kinetics of red pepper (Capsicum annuum L var Jaranda)
Authors: Sanjuán N , Lozano M , García‐Pascual P , Mulet A
Published: April 2003

Shredded and whole red pepper samples were dehydrated in a laboratory drier with a through‐flow air velocity of 0.5 m s−1 at 50, 55, 60 and 70 °C. Shredded peppers dried faster than whole peppers. The drying behaviour of whole samples was characterised by a constant‐ and a falling‐rate drying period, whilst that of shredded samples was characterised by a falling‐rate drying period only. The mass transfer coefficient for whole samples during the constant‐rate period was computed experimentally. The effect of temperature on the mass transfer coefficient was described by the Arrhenius model. The activation energy was 58 kJ mol−1. In the falling‐rate period the mass transfer was described by a diffusional model, and the effective diffusion coefficient at each temperature was determined. Diffusion coefficients were estimated to lie between 4.38 × 10−11 and 10.99 × 10−11 m2 s−1 for whole peppers and between 37.23 × 10−11 and 99.61 × 10−11 m2 s−1 for shredded peppers. The effect of temperature on the effective diffusion coefficient was described by the Arrhenius equation, with an activation energy of 44 kJ mol−1 for whole peppers and 56 kJ mol−1 for shredded peppers.

© 2003 Society of Chemical Industry