bluuebunny/crossref_metadata_2025 huggingface dataset:
A Gift of a Pagoda, the Presence of a Prominent Citizen, and the Possibilities of Hospitality
Authors: Chan Wun Fung
Published: January 2005

To counter accusations that ethnic minorities in Britain are a problem, there is an emerging discourse that has begun to celebrate diversity as an asset, which contributes towards the nation's cultural and economic vitality. However, although this reevaluation of ethnic differences has proved to be a useful defence of the presence of ethnic minorities, the types of contributions and their significance have been left unexplored. In this paper I closely examine one such contribution, a Chinese pagoda, which was given to the City of Birmingham by an ethnic entrepreneur. By carefully analysing the views of the gift giver, planning documents, and public discourse on the pagoda, I argue that the different narratives—which encompass the themes of representing an ethnic community, hospitality, and gift giving—are discontinuous. In doing so, I illustrate some of the limits to Birmingham's hospitality and mark out a series of informal obligations of citizenship that are written into Birmingham's public space. I conclude by suggesting that if a gift of hospitality is to be given it is necessary to consider the other of the ethnic minority as an asset, citizenship, and presence.
Repetitive and Troubling Discourses of Nationalism in the Local Politics of Mosque Development in Sydney, Australia
Authors: Dunn Kevin M
Published: January 2005

The contested nature of multiculturalism in Australia is stark in local debates over mosque developments in Sydney. Queer-theory concepts (citation, repetition, sedimentation, and troubling) are used to reveal the differing utilities of discourses on nationalism at this everyday level. Neoconservatives oppose the declining normativity of Anglo-Celtic culture, and nostalgically invoke “White (or Anglo-Celtic) Australia”. Mosque opponents are both limited and empowered by this discourse of nationalism. The official recognition of Australia's multicultural composition and the shift in rhetoric on national identity have provided a counterideology to the still hegemonic constructions of an Anglo-Celtic Australia. Muslim associations and their supporters have drawn on these symbolic tools in their arguments with planning-consent authorities, and in other local political forums. Through the repetition of their claims to local and national citizenship, and by evoking the rhetoric of multiculturalism, they challenged the hegemony of Anglo-Celtic culture. A deeper and broader multiculturalism may be sedimented through the reiterative deployment of the national discourse of multiculturalism.
Diagramming Practice and Performance
Authors: McCormack Derek P
Published: January 2005

In this paper I seek to apprehend some of the powers of nonrepresentational practice and performance through an encounter with the rhythmic movement of the body. I concentrate on eurhythmics, a practice that emerged in Geneva in the late 19th century and early 20th century as an effort to improve musical appreciation through rhythmic movement. Drawing on work in cultural and architectural theory, I argue that the historical and cultural geographies of eurhythmics can best be apprehended diagrammatically. Specifically, I situate eurhythmics in diagrammatic relation to the corporeal kinaesthetics of rhythmic movement, to practices of social and cultural transformation, and to architectures of performative potential. By apprehending the geographies of eurhythmics in this way, I not only work to demonstrate that nonrepresentational styles of thinking and working multiply rather than undermine the field of power in which geographers move, but also present a sense of how these powers can become implicated in the very practice and performance of geographical research.
Subject departments as professional communities?
Authors: Visscher Adrie , Witziers Bob
Published: January 2005

A growing body of literature suggests that when schools become professional communities there are expected benefits in terms of teacher learning, school improvement and student achievement. In this article the concept of professional communities is examined for certain subject departments in Dutch secondary schools. The authors report on research into the extent to which mathematics departments operate as professional communities. At the same time, it was investigated whether the level at which departments operate as professional communities is related to student achievement. The results indicate that departments are cohesive bodies regulating teacher behaviour in several respects. However, as professional communities they do not focus on improving the quality of their teachers and instruction. Some characteristics of professional communities prove to be beneficial for student achievement, while others are not. The authors offer recommendations on how departments can develop into more professionally organised communities.
SATurated models of pupildom: Assessment and inclusion/exclusion
Authors: Hall Kathy , Collins Janet , Benjamin Shereen , Nind Melanie , Sheehy Kieron
Published: January 2005

Adopting a sociocultural theoretical framework and based on ethnographic data from two primary schools, this article seeks to answer the question: what meanings about inclusion and exclusion are encoded in school and classroom practices? It documents the (inclusionary and) exclusionary pedagogic processes that influence learning and children's participation in the learning opportunities on offer to them. From their analysis of observational, interview and documentary data, externally‐imposed and monitored regimes of assessment are what really matters in the school lives of the year six children in the authors' fieldwork schools. Assessment, narrowed to testing, defines the school day, the curriculum, the teacher's responsibilities, the pupil's worth, the ideal parent, and what counts as ability; it pushes towards a particular type of learning at the expense of other types. The article begins with a brief theoretical and methodological account of the study and a note on each participating school. It then suggests and discusses models of ‘SATurated pupildom' that are supported by the data. Versions of learning and ability as well as teacher subject positions that variously fit with the demands of summative assessments for accountability purposes, but that do not square with valuing diversity, are also discussed. The conclusion briefly considers the findings in the context of a macro‐culture that circumscribes what schools and teachers must value most and in relation to tensions within New Labour's push for standardisation on the one hand and inclusion and social justice on the other.
The synthesis of subject and pedagogy for effective learning and teaching in primary science education
Authors: Parker Joan
Published: January 2005

The issue of science subject knowledge, and how to address the demands of this for both practising and trainee primary teachers, has constituted a core research enterprise in recent decades. The Professional Standards for Qualified Teacher Status entail considerable conceptual demands for many primary trainees. Generating meaningful causal explanations of scientific phenomena lies at the heart of both the scientific endeavour itself, and of effective classroom teaching. To focus on knowledge acquisition per se in teacher education, however, obscures the critical issue of subject‐related pedagogical knowledge that ultimately influences classroom practice. This article explores the development of both subject knowledge and subject‐related pedagogical knowledge in science education. It is informed by science education literature, as well as by a substantial body of empirical research into trainees' learning of aspects of physical science accumulated over a five‐year period. Learners' perspectives of the synthesis of subject and pedagogy raise important questions concerning the nature of teacher education.
When performance is the product: Problems in the analysis of online distance education
Authors: Hamilton David , Dahlgren Ethel , Hult Agneta , Roos Bertil , Söderström Tor
Published: January 2005

This article examines two ideologies that have been prominent in recent, if not current, education thinking. The first is that means can be separated from ends (or processes from products); the second is that learning is merely a process of knowledge acquisition. Attention to these ideologies arises from two projects in the overlapping fields of information and communications technology (ICT) and instructional design. Both projects attend to conversation as an educational resource. They are animated by the questions: should a conversation be regarded as an activity in context or can it be decoupled from the circumstances that define it as a conversation? In other words, does a conversation take place within an environment, or by means of the environment? Relating these questions to the changing view of ICT held within the European Community, the article uses a bricolage of ideas from economic history, communication theory and discourse analysis to summarise how such inherited ideologies might be realigned in the analysis of online conversation.
Cisplatin-Induced Renal Interstitial Fibrosis in Neonatal Rats, Developing as Solitary Nephron Unit Lesions
Authors: Yamate Jyoji , Machida Yuuko , Ide Mika , Kuwamura Mitsuru , Kotani Takao , Sawamoto Osamu , LaMarre Jonathan
Published: January 2005

Cisplatin (CDDP)-induced renal lesions in rats prove a useful model for analysis of the pathogenesis of post-tubular injury-renal interstitial fibrosis. This study investigated the histopathological changes in 10-day-old neonatal rats induced by a single injection of CDDP (4.5 mg/kg). Compared with age-matched controls, on postinjection (PI) days 1 to 6, the number of apoptotic cells, demonstrable with TUNEL method, was significantly increased in CDDP-treated neonates, and there was no marked epithelial necrosis nor fibrotic lesions. Fibrotic lesions began to be developed solitarily around some nephrons with dilated ducts in the corticomedullary junction on PI day 10 and the lesions became more prominent until PI day 20. The α-SMA-positive myofibroblastic cells were seen exclusively in the fibrotic lesions. Additionally, the numbers of macrophages reacting with ED1 (specific for exudate macrophages), ED2 (for resident macrophages), and OX6 (recognizing MHC class II antigens expressed in antigen-presenting macrophages/dendritic cells) were significantly increased around the affected renal tubules. A greater immunoreaction for TGF-β1 was seen mostly in the renal epithelial cells of CDDP-treated neonates. These findings indicated that macrophage populations and myofibrolastic cells as well as TGF-β1 may be responsible for the production of neonatal renal interstitial fibrosis. Compared with CDDP-injected adult rats that develop extensive interstitial fibrosis (Yamate et al., J Comp Pathol, 1995), the formation of fibrotic lesions was delayed, and the lesions were limited to the area around the affected nephrons; this could be attributable to differences in renal morphology between neonates and mature kidney of adult rats.
Temporal Reduction in Size of Salivary Acinus in Rats Induced by Theophylline
Authors: Kajikawa Satoru , Takeuchi Ayano , Nii Aisuke , Nakayama Hiroyuki , Doi Kunio
Published: January 2005

Repeated administration of theophylline, a phosphodiesterase inhibitor, induces the enlargement of the salivary glands in rats. Time-course changes after a single administration of theophylline were examined in the salivary glands, including phosphodiesterase enzyme activity, and the expression of aquaporin 5 (AQP5), a water channel. We also examined the contribution of β-adrenergic receptors to theophylline-induced salivary changes. Male F344 rats were given 50 mg/kg of theophylline intraperitoneally either alone or concurrently with a 10 mg/kg subcutaneous injection of propranolol. After treatment with theophylline alone, the weight and histology of the submaxillary and parotid glands were examined. Phosphodiesterase activity and AQP5 were detected by enzyme- and immuno-histochemistry, respectively. At 4 hours, 8 hours, or both, organ weights were decreased with depletion of secretory vesicles in the acinar cells. In the submaxillary glands, reduced activity of phosphodiesterase and increased expression of AQP5 in the intercalated ducts were observed at 4 hours. When co-administered, propranolol partially abolished theophylline-induced glandular reduction. These results suggest that the theophylline-induced transient reduction in size of the salivary glands is attributable not only to phosphodiesterase inhibition but also to β-adrenergic receptor activation and that the intercalated ducts in submaxillary glands play a role in the production of saliva.
Tubular Kidney Damage and Centrilobular Liver Injury after Intratracheal Instillation of Dimethyl Selenide
Authors: Cherdwongcharoensuk Duangrudee , Henrique Rui , Upatham Suchart , Pereira António Sousa , Águas Artur P.
Published: January 2005

Accidental inhalation of selenium (Se) derivatives, such as dimethyl selenide (DMSe), has been associated with damage of respiratory tissues. However, systemic effects of inhaled Se have not been thoroughly established. We have investigated whether mouse kidney and liver show cellular pathology as a result of a single intratracheal instillation of two different doses of DMSe (0.05 and 0.1 mg Se/kg BW). The animals were sacrificed 1, 7, 14, and 28 days after either 1 of the 2 DMSe treatments; samples were studied by light microscopy. Instillation of the low DMSe dose resulted in acute and transient tubular disease of the kidney expressed by swelling and vacuolation of epithelial cells of proximal tubules; in some mice, tubular necrosis was observed. After 14 days of the DMSe treatment, these lesions were ameliorated and, by day 28, the kidney tubular epithelium depicted a normal morphology. The same low dose of DMSe caused sustained damage to centrilobular hepatocytes characterized by swollen and vacuolized liver cells. After the instillation of the high DMSe dose, the mice presented sustained liver and kidney focal necrosis. Our data suggest that inhalation of DMSe results in: (i) acute tubular injury of the kidney and damage to centrilobular liver cells and (ii) this systemic pathology induced by DMSe is a dose-dependent phenomenon.
Differential Expression of COX-1 and COX-2 in the Gastrointestinal Tract of the Rat
Authors: Haworth Richard , Oakley Keli , McCormack Nicola , Pilling Andrew
Published: January 2005

The aim of this study was to use immunohistochemistry with morphometry to investigate COX-1 and COX-2 expression in the normal rat gastrointestinal (GI) tract and examine if sites of ulceration previously observed with long-term COX-2 inhibitor administration in mice correlate with differential COX-1/COX-2 expression. COX-2 positive cells were observed predominantly in the apical lamina propria of intestinal villi with fewer cells in the mucosal epithelium. The highest level of COX-2 expression was observed at the ileocaecal junction (ICJ). COX-2 expression was also present in parasympathetic ganglia of the submucosa and muscularis. In the stomach, the highest grade of COX-2 expression was observed in the apical lamina propria of the fundus adjacent to the junctional ridge. In contrast, COX-1 positive cells within the lamina propria were evenly distributed along the GI tract but were present in higher numbers than COX-2 positive cells. The mean level of COX-1 expression at the ICJ was not significantly different from the ileum and caecum. Evidence that the highest level of COX-2 expression in normal rats is located on the ileal side of the ICJ provides the first mechanism to explain spontaneous ulceration and perforation of the distal ileum in COX-2−/− animals.
Histopathological Study of Time Course Changes in PTHrP-Induced Incisor Lesions of Rats
Authors: Kato Atsuhiko , Suzuki Masami , Karasawa Yayoi , Sugimoto Tetsuro , Doi Kunio
Published: January 2005

Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). In the present study using HHM model rats, the time course of odontoblastic response to PTHrP and its relation to incisal fracture were elicited. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, mandibular incisors were collected at several time points. Microscopically 3 distinctive types of odontoblastic/dentin lesions were observed. Hypercalcfied dentin, which was reported as hypercalcemia-induced lesion in previous reports, observed in all areas of the dentin from week 5–10 samplings. Dentin niche, observed solely in week-10 sampling point, exhibited a nature identical to that of reparative odontoblast reported in the literatures of various cytotoxic agents. Since cytotoxicites were neither observed prior to the lesions nor reported as a role of PTHrP, the reparative response may have derived from highly sustained levels of PTHrP. Loss of columnar odontoblasts height was initially observed at week-5 time point in the middle section of the incisor. This primary loss of cell height prior to incisor fracture was considered to be the earliest response to the increased PTHrP levels of this model.
Associativity of crossed products by partial actions, enveloping actions and partial representations
Authors: Dokuchaev M. , Exel R.
Published: January 2005

Given a partial action

α
\alpha

of a group

G
G

on an associative algebra

A

\mathcal {A}

, we consider the crossed product

A

⋊
α

G

\mathcal {A}\rtimes _\alpha G

. Using the algebras of multipliers, we generalize a result of Exel (1997) on the associativity of

A

⋊
α

G

\mathcal {A}\rtimes _\alpha G

obtained in the context of

C
∗

C^*

-algebras. In particular, we prove that

A

⋊

α

G

\mathcal {A} \rtimes _{\alpha } G

is associative, provided that

A

\mathcal {A}

is semiprime. We also give a criterion for the existence of a global extension of a given partial action on an algebra, and use crossed products to study relations between partial actions of groups on algebras and partial representations. As an application we endow partial group algebras with a crossed product structure.
Extension-orthogonal components of preprojective varieties
Authors: Geiß Christof , Schröer Jan
Published: January 2005

Let

Q
Q

be a Dynkin quiver, and let

Λ
\Lambda

be the corresponding preprojective algebra. Let

C

=
{

C
i

∣
i
∈
I
}

{\mathcal C} = \{ C_i \mid i \in I \}

be a set of pairwise different indecomposable irreducible components of varieties of

Λ
\Lambda

-modules such that generically there are no extensions between

C
i

C_i

and

C
j

C_j

for all

i
,
j

i,j

. We show that the number of elements in

C

{\mathcal C}

is at most the number of positive roots of

Q
Q

. Furthermore, we give a module-theoretic interpretation of Leclerc’s counterexample to a conjecture of Berenstein and Zelevinsky.
Cut numbers of 3-manifolds
Authors: Sikora Adam
Published: January 2005

We investigate the relations between the cut number,

c
(
M
)
,

c(M),

and the first Betti number,

b
1

(
M
)
,

b_1(M),

of

3
3

-manifolds

M
.

M.

We prove that the cut number of a “generic”

3
3

-manifold

M
M

is at most

2.
2.

This is a rather unexpected result since specific examples of

3
3

-manifolds with large

b
1

(
M
)

b_1(M)

and

c
(
M
)
≤
2

c(M)\leq 2

are hard to construct. We also prove that for any complex semisimple Lie algebra

g

\mathfrak g

there exists a

3
3

-manifold

M
M

with

b
1

(
M
)
=
d
i
m

g

b_1(M)=dim\, \mathfrak g

and

c
(
M
)
≤
r
a
n
k

g

.

c(M)\leq rank\, \mathfrak g.

Such manifolds can be explicitly constructed.
Graphs of zeros of analytic families
Authors: Brudnyi Alexander
Published: January 2005

Let

F

:=
{

f

λ

}

\mathcal {F}:=\{f_{\lambda }\}

be a family of holomorphic functions in a domain

D
⊂

C

D\subset \mathbb {C}

depending holomorphically on

λ
∈
U
⊂

C

n

\lambda \in U\subset \mathbb {C}^{n}

. We study the distribution of zeros of

{

f

λ

}

\{f_{\lambda }\}

in a subdomain

R
⊂⊂
D

R\subset \subset D

whose boundary is a closed non-singular analytic curve. As an application, we obtain several results about distributions of zeros of families of generalized exponential polynomials and displacement maps related to certain ODE’s.
From Γ-spaces to algebraic theories
Authors: Badzioch Bernard
Published: January 2005

The paper examines semi-theories, that is, formalisms of the type of the

Γ
\Gamma

-spaces of Segal which describe homotopy structures on topological spaces. It is shown that for any semi-theory one can find an algebraic theory describing the same structure on spaces as the original semi-theory. As a consequence one obtains a criterion for establishing when two semi-theories describe equivalent homotopy structures.
Compactness of isospectral potentials
Authors: Donnelly Harold
Published: January 2005

The Schrödinger operator

−
Δ
+
V

-\Delta +V

, of a compact Riemannian manifold

M
M

, has pure point spectrum. Suppose that

V
0

V_0

is a smooth reference potential. Various criteria are given which guarantee the compactness of all

V
V

satisfying

spec
⁡
(
−
Δ
+
V
)
=
spec
⁡
(
−
Δ
+

V
0

)

\operatorname {spec}(-\Delta +V)=\operatorname {spec}(-\Delta +V_0)

. In particular, compactness is proved assuming an a priori bound on the

W

s
,
2

(
M
)

W_{s,2}(M)

norm of

V
V

, where

s
>
n

/

2
−
2

s>n/2-2

and

n
=
dim
⁡
M

n=\dim M

. This improves earlier work of Brüning. An example involving singular potentials suggests that the condition

s
>
n

/

2
−
2

s>n/2-2

is appropriate. Compactness is also proved for non–negative isospectral potentials in dimensions

n
≤
9

n\le 9

.
Determination of single-crystal elasticity constants in a cubic phase within a multiphase alloy: X-ray diffraction measurements and inverse-scale transition modelling
Authors: Fréour S. , Gloaguen D. , François M. , Perronnet A. , Guillén R.
Published: January 2005

The scope of this work is the determination of single-crystal elastic properties from X-ray diffraction stress analysis performed on multiphase polycrystals. An explicit three-scale multiphase inverse self-consistent model is developed in order to express the single-crystal elasticity constants of a cubic phase as a function of its X-ray elasticity constants. The model is verified in the case of single-phase materials. Finally, it is applied to a two-phase (α+β) titanium-based alloy (Ti-17) and, as a result, the Ti-17 β-phase single-crystal elasticity tensor is estimated.
Stress analysis of polycrystalline thin films and surface regions by X-ray diffraction
Authors: Welzel U. , Ligot J. , Lamparter P. , Vermeulen A. C. , Mittemeijer E. J.
Published: January 2005

The components of the macroscopic mechanical stress tensor of a stressed thin film, coating, multilayer or the region near the surface of a bulk material can in principle be determined by X-ray diffraction. The various analysis methods and measurement strategies, in dependence on specimen and measurement conditions, are summarized and evaluated in this paper. First, different X-ray diffraction geometries (conventional or grazing incidence) are described. Then, the case of macroscopically elastically isotropic, untextured specimens is considered: from the simplest case of a uniaxial state of stress to the most complicated case of a triaxial state of stress. The treatment is organized according to the number of unknowns to be determined (i.e.the state of stress, principal axes known or unknown), the use of one or several values of the rotation angle φ and the tilt angle ψ of the sample, and one or multiplehklreflections. Next, the focus is on macroscopically elastically anisotropic (e.g.textured) specimens. In this case, the use of diffraction (X-ray) elastic constants is not possible. Instead, diffraction (X-ray) stress factors have to be used. On the basis of examples, it is demonstrated that successful diffraction stress analysis is only possible if an appropriate grain-interaction model is applied.
Ostwald ripening of cobalt precipitates in silica aerogels? An ultra-small-angle X-ray scattering study
Authors: Braun Artur , Ilavsky Jan , Dunn Brian C. , Jemian Pete R. , Huggins Frank E. , Eyring Edward M. , Huffman Gerald P.
Published: January 2005

Monolithic silica aerogels with radial symmetry were synthesized by supercritical drying, doped to 2% and 10% with cobalt, and reduced with hydrogen. All samples were investigated with ultra-small-angle X-ray scattering. The non-doped aerogels have three populations of scatterers with radii of gyration of about 10, 40 and 60–70 Å. The doped aerogels show an additional structure with a radius of gyration ranging from 1050 to 3000 Å. This structure causes intensity oscillations, thus revealing a relatively narrow size distribution. Scattering curves of the 10%-doped aerogels fitted well to a Lifshitz–Slyozov–Wagner particle size distribution, thus revealing that Ostwald ripening might have occurred during aerogel preparation. The same range also shows differences depending on whether the samples were reduced, or in their as-prepared condition. Scattering curves obtained from the cylinder-axis region were different from the scattering curves obtained from the sample boundary, indicating a process-dependent skin effect.
Shannon information as a measure of distortion in coordination polyhedra
Authors: Lalik Erwin
Published: January 2005

Variations in the distribution of bond orders within coordination polyhedra in crystals have been used as a scale of departure from perfect polyhedral symmetry and a measure of polyhedral distortion. The distribution of bond orders mathematically resembles the probability distribution; the bond orders can be normalized to their sum within a polyhedron and used to calculate the Shannon information content that depends on the degree of their departure from uniform distribution. The difference in the Shannon information between a perfect and a distorted polyhedron can be defined as a function taking bond orders as arguments to yield a non-negative real value unambiguously ascribed to a polyhedron. The so-defined distortion function is continuous and vanishes for all the bond orders being equal in the case of a perfect polyhedron. For small distortions it can be reduced to a form analogous to the well known chi-squared function.
Rietveld texture analysis of complex oxides: examples of polyphased Bi2223 superconducting and Co349 thermoelectric textured ceramics characterization using neutron and X-ray diffraction
Authors: Guilmeau Emmanuel , Chateigner Daniel , Noudem Jacques , Funahashi Ryoji , Horii Shigeru , Ouladdiaf Bachir
Published: January 2005

Orientation distributions of cobaltite thermoelectric and polyphased bismuth-based cuprate superconducting textured materials are determined from neutron and X-ray diffraction analysis. Curved position-sensitive detectors coupled to a tilt-angle (χ) scan enable the treatment of the whole diffraction pattern using the combined Rietveld–WIMV–Popa algorithm. The textures of three phases of superconducting compounds are determined. The critical current densities, measured for four samples, are strongly dependent on the calculated texture strengths, crystallite sizes and phase ratios. For the cobaltite compounds, a comparison between X-ray and neutron analysis shows the advantages of the latter technique for avoiding the limitations of the X-ray analysis with respect to the defocusing effect. The results highlight the necessity and efficiency of the combined approach for a quantitative texture analysis of complex materials and exemplify the texture–anisotropic physical properties relationship for a better understanding and design of improved bulk superconducting and thermoelectric materials.
Characterization of ordered mesoporous films on silicon (001) surface using X-ray and electron diffraction
Authors: Liu Pang-Hung , Chao Kuei-Jung , Guo Xing-Jian , Huang Kuo-Ying , Lee Yen-Ru , Cheng Cheng-Wen , Chiu Mau-Sen , Chang Shih-Lin
Published: January 2005

A continuous silica film with well aligned mesochannels parallel to the Si(001) surface was found to be formed through sol–gel dip-coating of a silica precursor with nonionic ethylene oxide surfactant. Two two-dimensional mesoporous structures in centered and non-centered rectangular symmetries and with the short axes of elongated ellipsoidal pores normal to the surface were observed by X-ray and electron diffraction. Detailed transmission electron microscopy investigations were employed to view the direction dependence of the channel or pore packing in the continuous film.
Cognitive Functioning in Community Dwelling Older Adults with Chronic Partial Epilepsy
Authors: Martin Roy C. , Griffith H. Randall , Faught Edward , Gilliam Frank , Mackey Melissa , Vogtle Laura
Published: January 2005

Summary:  Purpose: To examine cognitive functioning in community‐dwelling older adults with chronic partial epilepsy and demographically matched healthy older adults.

Methods: Standardized measures of neurocognitive function were collected as part of an ongoing study investigating health‐related quality‐of‐life issues in older adults with epilepsy. Cognitive tests consisted of the Mattis Dementia Rating Scale (subscales include attention, initiation/perseveration, construction, conceptualization, memory), Logical Memory subtest from the WMS‐III (immediate and delayed recall scores), and word fluency. Mood was measured with the Geriatric Depression Scale. Older adults with epilepsy (n = 25) and healthy older adults (n = 27) completed testing. All participants were at least 60 years old, living independently in the community, and had no history of drug/alcohol abuse or life‐threatening medical conditions. All older adults with epilepsy had been diagnosed as having medically intractable partial complex seizures, including those with histories of secondary generalization.

Results: Older adults with epilepsy demonstrated impairments across all cognitive measures compared with the healthy controls. Seizure onset (age) and seizure duration (years) were not statistically associated with neurocognitive function or self‐reported mood. Older adults with epilepsy who were receiving antiepileptic drug (AED) polytherapy (n = 11) displayed worse performance on the attention, initiation/perseveration, and memory subscales of the DRS and Logical Memory delayed recall score compared with those older adults with epilepsy receiving monotherapy (n = 14). The number of AEDs taken was not associated with seizure frequency.

Conclusions: Negative effects on cognitive function are experienced by older adults with chronic partial epilepsy. AED polytherapy may increase the risk for negative cognitive dysfunction.
Functional MRI Predicts Memory Performance after Right Mesiotemporal Epilepsy Surgery
Authors: Janszky Jozsef , Jokeit Hennric , Kontopoulou Konstantina , Mertens Markus , Ebner Alois , Pohlmann‐Eden Bernd , Woermann Friedrich G.
Published: January 2005

Summary:  Purpose: Anterior temporal lobe resection (ATR) is a treatment option in drug‐resistant epilepsy. An important risk of ATR is loss of memory because mesiotemporal structures contribute substantially to memory function. We investigated whether memory‐activated functional MRI (fMRI) can predict postoperative memory loss after anterior temporal lobectomy in right‐sided medial temporal lobe epilepsy (MTLE).

Methods: We included 16 patients (10 women) aged 16–54 years. The mean age at epilepsy onset was 12.5 years (range, 1–26 years). The patients' mean Wechsler IQ score was 95.2 (range, 62–125). The activation condition of fMRI consisted of retrieval from long‐term memory induced by self‐paced performance of an imaginative walk. All but one patient had left‐sided speech dominance according to speech‐activated fMRI. Outside the scanner, we evaluated the pre‐ and postoperative visual memory retention by using Rey Visual Design Learning Test.

Results: We found a correlation between the preoperative asymmetry index of memory‐fMRI and the change between pre‐ and postsurgical measures of memory retention. Reduced activation of the mesiotemporal region ipsilateral to the epileptogenic region correlated with a favorable memory outcome after right‐sided ATR.

Conclusions: In light of the postoperative results, the theoretical implication of our study is that fMRI based on a simple introspective retrieval task measures memory functions. The main clinical implication of our study is that memory‐fMRI might replace the invasive Wada test in MTLE by using a simple fMRI paradigm. Predictive power, however, will be studied in larger patient samples. Other studies are required for left‐sided MTLE and neocortical epilepsies to assess the clinical usefulness of memory‐fMRI.
The Role of bcl‐2 Family of Genes During Kindling
Authors: Akcali Kamil Can , Sahiner Melike , Sahiner Turker
Published: January 2005

Summary:  Purpose: Several experimental models of human temporal lobe epilepsy have shown that apoptotic death of neurons is an important part of this degenerative disease. However, the role of apoptotic regulators is not clear during the epileptogenesis. Therefore we investigated the expression pattern of bcl‐2 family of genes during the formation of kindling model of epilepsy in rats.

Methods: We examined the expression pattern of bax, bcl‐2, bcl‐xL, mtd, and bcl‐w both at messenger RNA (mRNA) and protein level in the brain tissues during the formation of epilepsy with kindling model in adult rats, which has been the most acceptable form of experimental model of human epilepsy. We also assessed the onset of DNA fragmentation by using the terminal deoxynucleotidyl transferase–mediated dUTP nick‐end labeling (TUNEL) assay.

Results: Animals have started to have epileptic discharges after day 10 of kindling model. Recurrent subthreshold electrical stimuli induced not only epileptic foci but also the expression of bax, an inducer of apoptosis, in this time period. Conversely, bcl‐xL, which is an inhibitor of apoptosis, had an opposite pattern of expression both at mRNA and protein level during the formation of epilepsy. We did not observe DNA fragmentation by TUNEL staining.

Conclusions: Our study shows differential expression of Bax and Bcl‐xL at the CA1 region during the formation of hippocampal kindling model. The absence of DNA fragmentation during this period suggests that epileptic changes in neurons have the potential to induce DNA fragmentation by altering the expression levels of Bax and Bcl‐xL.
Incidence of Fractures among Epilepsy Patients: A Population‐based Retrospective Cohort Study in the General Practice Research Database
Authors: Souverein Patrick C. , Webb David J. , Petri Hans , Weil John , Van Staa Tjeerd P. , Egberts Toine
Published: January 2005

Summary:  Purpose: To compare the incidence of various fractures in a cohort of patients with epilepsy with a reference cohort of patients not having epilepsy.

Methods: Patients were included in the epilepsy cohort if they had at least one diagnosis of epilepsy in their medical history and had sufficient evidence of “active” epilepsy (use of antiepileptic drugs, diagnoses) after the practice was included in the General Practice Research Database (GPRD). Two reference patients were sampled for each patient with epilepsy from the same practice. Primary outcome was the occurrence of any fracture during follow‐up. Poisson regression analysis was used to estimate incidence density ratios (IDRs).

Results: The study population comprised 40,485 and 80,970 patients in the epilepsy and reference cohorts, respectively. The median duration of follow‐up was ∼3 years. The overall incidence rate in the epilepsy cohort was 241.9 per 10,000 person‐years. This rate was about twice as high as that in reference cohort: age‐ and sex‐adjusted IDR, 1.89 (95% CI, 1.81–1.98). When comparing IDRs among the different groups of fractures, the highest relative‐risk estimate was found for hip and femur fractures (adjusted IDR, 2.79; 95% CI, 2.41–3.24). IDRs were consistently elevated across age and sex groups and across fracture subtypes.

Conclusions: The overall risk of fractures was nearly twice as high among patients with epilepsy compared with the general population. The relative fracture risk was highest for hip and femur. Further study is necessary to elucidate whether this elevated risk is due to the disease, the use of antiepileptic drugs, or both.
Reduced Anesthetization during the Intracarotid Amobarbital (Wada) Test in Patients Taking Carbonic Anhydrase–Inhibiting Medications
Authors: Bookheimer Susan , Schrader Lara M. , Rausch Rebecca , Sankar Raman , Engel Jerome
Published: January 2005

Summary:  Purpose: Failure to show adequate anesthetization during the intracarotid amobarbital procedure (IAP or “Wada test”) is a rare complication. After an unusually high rate of recent anesthetization failures, we sought to determine the frequency of reduced anesthetization and any common factors underlying these failures.

Methods: We reviewed the records of all patients who underwent IAP tests through the UCLA Seizure Disorder Center between September 1999 and May 2002. Age, date, epileptogenic focus, radiologist, and current medications were all considered.

Results: Of a total of 56 patients who underwent our intracarotid amobarbital examination, 11 (19.6%) showed either very rapid recovery (≤1 min) or anesthetization failure. Of these, 10 (91%) of 11 were taking a medication with some carbonic anhydrase–inhibiting (CAI) properties (topiramate (TPM), n = 7; zonisamide (ZNS), n = 2; hydrochlorothiazide and furosemide, n = 1 each). The only patient of 40 (2.5%) who was not taking any CAI drugs and showed an early IAP recovery (55 s) had recently discontinued TPM. IAPs performed on patients after weaning from TPM showed a correlation between length of drug discontinuation and duration of anesthesia effect.

Conclusions: Our data strongly suggest that recent failures of anesthetization during the IAP are associated with a possible interaction between amobarbital and medications possessing CAI properties. We suggest that the IAP be performed only after ≥8 weeks after discontinuation of such medications.
Characterization of the Tetanus Toxin Model of Refractory Focal Neocortical Epilepsy in the Rat
Authors: Nilsen Karen E. , Walker Matthew C. , Cock Hannah R.
Published: January 2005

Summary:  Purpose: To characterize in detail a model of focal neocortical epilepsy.

Methods: Chronic focal epilepsy was induced by injecting 25–50 ng of tetanus toxin or vehicle alone (controls) into the motor neocortex of rats. EEG activity was recorded from electrodes implanted at the injection site, along with facial muscle electromyographic (EMG) activity and behavioral monitoring intermittently for up to 5 months in some animals. Drug responsiveness was assessed by using the antiepileptic drugs (AEDs) diazepam (DZP) and phenytoin (PHT) delivered systemically, while 1,2,3,4‐tetrahydro‐6‐nitro‐2,3‐dioxo‐benzo[f]quinoxaline‐7‐sulfonamide (NBQX), a competitive antagonist at AMPA receptors, was administered directly to the brain to investigate the potential benefits of focal drug delivery.

Results: Tetanus toxin induced mild behavioral seizures that persisted indefinitely in all animals. EEG spiking activity, occurring up to 80% of the time, correlated with clinical seizures consisting of interrupted behavioral activity, rhythmic bilateral facial twitching, and periods of abrupt motor arrest. Seizures were refractory to systemic administration of DZP and PHT. However, focal delivery of NBQX to the seizure site reversibly reduced EEG and behavioral seizure activity without detectable side effects.

Conclusions: This study provides a long‐term detailed characterisation of the tetanus toxin model. Spontaneous, almost continuous, well‐tolerated seizures occur and persist, resembling those seen in neocortical epilepsy, including cortical myoclonus and epilepsia partialis continua. The seizures appear to be similarly resistant to conventional AEDs. The consistency, frequency, and clinical similarity of the seizures to refractory epilepsy in humans make this an ideal model for investigation of both mechanisms of seizure activity and new therapeutic approaches.
Health‐related Quality of Life and Self‐perceived Competence of Children Assessed before and up to Two Years after Epilepsy Surgery
Authors: Van Empelen Ron , Jennekens‐Schinkel Aag , Van Rijen Peter C. , Helders Paul J. M. , Van Nieuwenhuizen Onno
Published: January 2005

Summary:  Purpose: To measure outcome of epilepsy surgery in terms of health‐related quality of life (HrQoL) and self‐perceived competence of children and adolescents.

Methods: Prospective longitudinal follow‐up study of 21 patients (aged 6.2 to 16.8 years). Frequency and severity of seizures and epilepsy‐related restrictions, HrQoL, and self‐perceived competence were rated before and 6, 12, and 24 months after epilepsy surgery. Data were analysed nonparametrically and using analysis of variance for repeated measures.

Results: Group‐wise, seizure parameters had almost normalized 6 months after surgery (p < 0.001) and remained so. Two years after surgery, 15 (72%) patients were free of seizures. At the first postsurgical assessment, parents and children evaluated the frequency of activities as improved and that of seizures as diminished (p < 0.05). Parents evaluated their children as having positive emotions more frequently (p < 0.05). Children started to feel better about seizure variables in the second year after surgery. Two years after surgery, children perceived themselves as being socially more competent and having greater self‐worth (p = 0.05). In the adolescent group, several aspects of self‐perceived competence improved shortly after surgery (p < 0.05), whereas 2 years after surgery, athletic competence and romance had improved (p < 0.05).

Conclusions: In children and adolescents, epilepsy surgery sets the stage for improvement in HrQoL and in competence to participate in social and societal domains. Most improvement occurs in the first 6 months after surgery.
Potential Role of Drug Transporters in the Pathogenesis of Medically Intractable Epilepsy
Authors: Kwan Patrick , Brodie Martin J.
Published: January 2005

Summary:  The pathogenesis underlying pharmacoresistance in epilepsy is unclear. One of the candidate mechanisms that has attracted growing interest is the limitation of antiepileptic drug (AED) access to the seizure focus by a range of efflux transporters, the prototype of which is P‐glycoprotein (P‐gp). P‐gp is encoded by the multidrug resistance (MDR1 or ABCB1) gene. Predominantly expressed in organs with excretory functions and at blood–tissue barriers, P‐gp is thought to act as a physiologic defense by extruding xenobiotics from mammalian cells and affording protection of sensitive organs. The high level of P‐gp in the cerebrovascular endothelium is believed to contribute to the functionality of the blood–brain barrier. Overexpression of P‐gp causes multidrug resistance in certain cancers. It has been hypothesized that overexpression of P‐gp and other efflux transporters in the cerebrovascular endothelium, in the region of the epileptic focus, also may lead to drug resistance in epilepsy. This hypothesis is supported by the findings of elevated expression of efflux transporters in epileptic foci in patients with drug‐resistant epilepsy, induction of expression by seizures in animal models, and experimental evidence that some commonly used AEDs are substrates. Conflicting reports suggest a possible association between variants of the MDR1 gene and medical intractability in epilepsy. Further studies to delineate the exact role, if any, of P‐gp and other efflux transporters in drug‐resistant epilepsy are warranted.
Glutamate Receptor Antagonists and Benzodiazepine Inhibit the Progression of Granule Cell Dispersion in a Mouse Model of Mesial Temporal Lobe Epilepsy
Authors: Suzuki Fumio , Heinrich Christophe , Boehrer Any , Mitsuya Koichi , Kurokawa Kiyoshi , Matsuda Masayuki , Depaulis Antoine
Published: January 2005

Summary:  Purpose: Unilateral intrahippocampal injection of kainic acid (KA) in adult mice induces the progressive dispersion of dentate granule cells, one of the characteristic pathologic changes of mesial temporal lobe epilepsy. However, little is known about the mechanisms that trigger this dispersion. In this study, the possible involvement of glutamatergic and γ‐aminobutyric acid (GABA)ergic neurotransmissions in the development of granule cell dispersion (GCD) was examined in this model.

Methods: Antagonists of N‐methyl‐d‐aspartate (NMDA) receptor (MK‐801) and non‐NMDA receptor (GYKI52466), and an agonist of benzodiazepine‐GABAA receptor (midazolam) were injected before and after KA in various ways, and the morphologic changes of the hippocampus, especially GCD, were examined.

Results: MK‐801 (5 mg/kg, i.p.) did not reduce GCD when injected 2 h before KA injection but inhibited GCD almost completely for ≤14 days, when injected 4 h after KA. However, mild to moderate dispersion was observed at 28 days, indicating that MK‐801 may delay the progression of GCD. Similarly, daily treatment with MK‐801 (2 × 1 mg/kg i.p./day) for the first 26 days after KA significantly reduced GCD. In contrast, GYKI52466 (30 mg/kg, s.c.) was effective only when it was injected before KA. A significant reduction of GCD was also observed after continuous administration of midazolam (10 mg/kg/h) after KA.

Conclusions: These data show that GCD in this mouse model is triggered by either the stimulation of the NMDA receptor or reduction of GABAA‐mediated inhibition after intrahippocampal injection of KA. It is suggested that the increased excitation or the reduced inhibition or both could be one of the factors triggering or maintaining or both the process of GCD.
Hippocampal Afterdischarges after GABAB‐Receptor Blockade in the Freely Moving Rat
Authors: Leung L. Stan , Canning Kevin J. , Shen Bixia
Published: January 2005

Summary:  Purpose: To determine whether hippocampal afterdischarges (ADs) and excitability changes were induced by γ‐aminobutyric acid (GABA)B‐receptor blockade in adult, freely moving rats.

Methods: A specific GABAB‐receptor antagonist CGP35348, CGP55845A, or CGP55699A was injected intracerebroventricularly (i.c.v.), and EEGs and behaviors of rats were analyzed.

Results: CGP35348 (56–110 μg, i.c.v.) induced afterdischarges (ADs) ∼60% of the time, starting at the hippocampus or neocortex. Neocortical‐onset ADs began with sporadic discharges and were <3 mV. Hippocampal‐onset ADs were bilateral, >5 mV, and spread to the entorhinal cortex and amygdala, often ending in a rebound AD and accompanied with stereotypic jumping, forelimb clonus, and wet‐dog shakes. The CGP35348‐induced hippocampal AD had an onset frequency (5–9 Hz) that was higher than the electrically evoked AD (2–4 Hz). CGP35348 i.c.v. also increased the mean starting frequency of an electrically evoked hippocampal AD from 3.6 Hz to 5.3 Hz. Hippocampal gamma activity (25–80 Hz) increased up to twofold for 30 min after a hippocampal but not a neocortical AD. A single dose of CGP35348 induced repeated ADs of increasing duration. Paired‐pulse inhibition of the evoked potentials in CA1, at interpulse interval of <100 ms, was decreased after but not before a hippocampal AD. CGP56999A (i.c.v.) gave results similar to those with CGP35348, whereas CGP55845A (i.c.v.) rarely induced ADs.

Conclusions: GABAB‐receptor blockade increases seizure susceptibility by reducing AD threshold and increasing the frequency and spread of a hippocampal AD. Hippocampal excitability (based on paired‐pulse test) and gamma activity increased after but not before a hippocampal AD.