bluuebunny/crossref_metadata_2025_split huggingface dataset:
H-Channels and Seizures: Less is More
Authors: Poolos Nicholas P. 
Published: May 2005

Seizure-induced Plasticity of h Channels in Entorhinal Cortical Layer III Pyramidal Neurons Shah MM, Anderson AE, Leung V, Lin X, Johnston D Neuron 2004;44:495–508 The entorhinal cortex (EC) provides the predominant excitatory drive to the hippocampal CA1 and subicular neurons in chronic epilepsy. Discerning the mechanisms underlying signal integration within EC neurons is essential for understanding network excitability alterations involving the hippocampus during epilepsy. Twenty-four hours after a single seizure episode when no behavioral or electrographic seizures occurred, we found enhanced spontaneous activity still present in the rat EC in vivo and in vitro. The increased excitability was accompanied by a profound reduction in Ih in EC layer III neurons and a significant decline in hyperpolarization-activated cation (HCN)1 and HCN2 subunits that encode for h channels. Consequently, dendritic excitability was enhanced, resulting in increased neuronal firing despite hyperpolarized membrane potentials. The loss of Ih and the increased neuronal excitability persisted for 1 week after seizures. Our results suggest that dendritic Ih plays an important role in determining the excitability of EC layer III neurons and their associated neural networks.
Experimental Febrile Seizures Require an Undetermined Factor for Induction of Hippocampal Sclerosis in Immature Rat Brain
Authors: Pitkänen Asla , Gröhn Olli 
Published: May 2005

Serial MRI after Experimental Febrile Seizures: Altered T2 Signal without Neuronal Death Dube C, Yu H, Nalcioglu O, Baram TZ Ann Neurol 2004;56:709–714 Whereas most febrile seizures (FSs) carry a benign outcome, a subpopulation of individuals with prolonged FSs are at risk for later temporal lobe epilepsy. Signal changes on MRI may provide early markers for changes in neuronal integrity that may promote epileptogenesis in such individuals. Here, we used serial MRIs, obtained before and at several times after experimental prolonged FSs, to determine the prevalence and distribution of signal changes on T2-weighted images and to investigate the pathologic substrates leading to these changes. Seventy-five percent of immature rats with experimental prolonged FSs had abnormal T2 signal enhancement at 24 hours, and 87.5%, at 8 days after the seizures. The altered T2 values involved the dorsal hippocampus (75%), the piriform cortex (87.5%), and the amygdala (25%). However, these changes were not accompanied by evidence of neuronal injury or death in these regions, as assessed by using the Fluoro-Jade method. Thus, experimental prolonged FSs lead to relatively frequent abnormal MRI signal in “temporal lobe” structures. Although these changes do not signify cell death, they may denote pathologic cellular processes that promote epileptogenesis.
MRI-negative Temporal Lobe Epilepsy: Is there a Role for PET?
Authors: Schwartz Theodore H. 
Published: May 2005

MRI-negative PET-positive Temporal Lobe Epilepsy: A Distinct Surgically Remediable Syndrome Carne RP, O'Brien TJ, Kilpatrick CJ, MacGregor LR, Hicks RJ, Murphy MA, Bowden SC, Kaye AH, Cook MJ Brain 2004;127:2276–2285 Most patients with nonlesional temporal lobe epilepsy (NLTLE) will have the findings of hippocampal sclerosis (HS) on a high-resolution MRI. However, a significant minority of patients with NLTLE and electroclinically well-lateralized temporal lobe seizures have no evidence of HS on MRI. Many of these patients have concordant hypometabolism on fluorodeoxyglucose-PET ([18F]FDG-PET). The pathophysiologic basis of this latter group remains uncertain. We aimed to determine whether NLTLE without HS on MRI represents a variant of or a different clinicopathologic syndrome from that of NLTLE with HS on MRI. The clinical, EEG, [18F]FDG-PET, histopathologic, and surgical outcomes of 30 consecutive NLTLE patients with well-lateralized EEG but without HS on MRI (HS–ve TLE) were compared with 30 consecutive age- and sex-matched NLTLE patients with well-lateralized EEG with HS on MRI (HS+ve TLE). Both the HS+ve TLE group and the HS–ve TLE patients had a high degree of [18F]FDG-PET concordant lateralization (26 of 30 HS–ve TLE vs. 27 of 27 HS+ve TLE). HS–ve TLE patients had more widespread hypometabolism on [18F]FDG-PET by blinded visual analysis [odds ratio (OR,+∞(2.51,–); P = 0.001]. The HS–ve TLE group less frequently had a history of febrile convulsions [OR,0.077 (0.002 to 0.512), P = 0.002], more commonly had a delta rhythm at ictal onset [OR,3.67 (0.97 to 20.47); P = 0.057], and less frequently had histopathologic evidence of HS [OR,0 (0 to 0.85); P = 0.031]. No significant difference in surgical outcome despite half of those without HS having a hippocampal-sparing procedure. Based on the findings outlined, HS–ve PET-positive TLE may be a surgically remediable syndrome distinct from HS+ve TLE, with a pathophysiologic basis that primarily involves lateral temporal neocortical rather than mesial temporal structures.
The Absence of Information about Hormones and Absence
Authors: Scharfman Helen E. 
Published: May 2005

Hormonal Regulation of Absence Seizures Persad V, Ting Wong CG, Cortez MA, Wang YT, Snead OC 3rd Ann Neurol 2004;44:353–361 A time course study that examined the effects of the female estrous cycle on the chronic slow spike-and-wave discharges (SSWDs), GABAB-receptor (GABABR) binding, and GABABR protein expression was conducted in Long-Evans hooded rats treated during development with a cholesterol synthesis inhibitor AY9944 (AY). In addition, a pharmacologic study using the hormones progesterone, 17 β-estradiol, mifepristone (intracellular progesterone-receptor antagonist), tamoxifen (intracellular estrogen-receptor antagonist), and allopregnanolone (progesterone metabolite) was performed to determine their effects on AY-induced seizures. The data indicate that a significant increase occurs in both the duration of SSWDs and GABABR binding in the AY model during the proestrus stage of the estrous cycle, the stage during which the levels of progesterone are at their highest. No changes in GABABR1a or R2 protein levels were observed. In addition, the administration of both progesterone and allopregnanolone exacerbated seizures in the AY model, whereas 17 β-estradiol attenuated the SSWD duration. Neither mifepristone nor tamoxifen blocked the effects of progesterone and 17 β-estradiol, respectively, on SSWD duration in the AY model, suggesting that these two sex hormones are working in a manner independent of their intracellular receptors. These data suggest an important role for steroid hormones in the regulation and maintenance of AY-induced atypical absence seizures.
Biatrial and Three‐Dimensional Mapping of Spontaneous Atrial Arrhythmias in Patients with Refractory Atrial Fibrillation
Authors: SAKSENA SANJEEV , SKADSBERG NICHOLAS D. , RAO HYGRIV B. , FILIPECKI ARTUR 
Published: May 2005

Introduction: While atrial fibrillation (AF) initiation in the pulmonary veins has been well‐studied, simultaneous biatrial and three‐dimensional noncontact mapping (NCM) has not been performed. We hypothesized that these two techniques would provide novel information on triggers, initiation, and evolution of spontaneous AF and permit study of different AF populations. Methods and Results: The origin of atrial premature beats (APBs), onset of spontaneous AF and its evolution were analyzed in 50 patients with AF in the presence or absence of structural heart disease (SHD) and in different AF presentations (group A: Persistent, group B: Paroxysmal). In 45 patients, spontaneous APBs in the right atrium (RA; n = 60) and left atrium (LA; n = 25) with similar regional distributions regardless of heart disease status were demonstrated. In total, 22 patients (44%) had ≥2 disparate regional origins. Biatrial regional foci were seen with equal frequency in patients with SHD (31%), without SHD (40%), in group A (32%), and in group B (36%). Biatrial mapping and NCM showed organized monomorphic atrial tachyarrhythmias arising in the RA (17), septum (17), or LA (21) and were classified as atrial flutter (RA = 34, LA = 8), macro‐reentrant atrial tachycardia (RA = 1, LA = 3) or focal atrial tachycardia (RA = 2, LA = 7). Their regional distribution was more extensive in patients with SHD and persistent AF compared with patients without SHD or paroxysmal AF. Simultaneous biatrial tachycardias were observed only in group A patients and those with SHD. Conclusions: Simultaneous biatrial and NCM permits successful AF mapping in different AF populations and demonstrates a biatrial spectrum of spontaneous triggers and tachycardias. Organized monomorphic tachycardias with multiple unilateral or biatrial locations are commonly observed in human AF. Patients with heart disease or persistent AF have a more extensive distribution as well as simultaneous coexistence of multiple tachycardias during AF.
Catheter Ablation of Atrial Fibrillation Versus Atrioventricular Junction Ablation Plus Pacing Therapy for Elderly Patients with Medically Refractory Paroxysmal Atrial Fibrillation
Authors: HSIEH MING‐HSIUNG , TAI CHING‐TAI , LEE SHIH‐HUANG , TSAO HUAN‐MING , LIN YUNG‐KUO , HUANG JIN‐LONG , CHAN PAUL , CHEN YI‐JEN , KUO JEN‐YUAN , TUAN TA‐CHUAN , HSU TSUI‐LIEH , KONG CHI‐WOON , CHANG SHIH‐LIN , CHEN SHIH‐ANN 
Published: May 2005

Background: Catheter ablation of atrial fibrillation (AF) has become another nonpharmacologic therapeutic option for medically refractory paroxysmal AF. Whether this method is better than atrioventricular (AV) junction ablation plus pacing therapy is unknown. The purpose of this study was to compare the very long‐term (longer than 4 years) clinical outcomes of the 2 methods in elderly patients (>65 years old) with medically refractory paroxysmal AF. Methods: From January 1995 to December 2001, 71 elderly patients with medically refractory paroxysmal AF were included; group 1 included 32 patients with successful AV junction ablation plus pacing therapy and group 2, 37 patients with successful catheter ablation of AF. Results: After a mean follow‐up of more than 52 months, the AF was better controlled in the group 1 patients than group 2 (100% vs 81%, P = 0.013), however, they had a significantly higher incidence of persistent AF (69% vs 8%, P < 0.001) and heart failure (53% vs 24%, P = 0.001). Furthermore, the incidence of ischemic stroke and cardiac death was similar between the 2 groups. Compared with the preablation values, a significant increase in the NYHA functional class (1.7 ± 0.9 vs 1.4 ± 0.7, P = 0.01) and significant decrease in the left ventricular ejection fraction (44 ± 8% vs 51 ± 10%, P = 0.01) were noted in the group 1 patients, but not in the group 2 patients. Conclusions: Although AV junction ablation plus pacing therapy better controlled the AF in elderly patients with medically refractory paroxysmal AF, that method was associated with a higher incidence of persistent AF and heart failure than catheter ablation of AF in the very long‐term follow‐up.
The Antiarrhythmic Peptide Analog ZP123 Prevents Atrial Conduction Slowing During Metabolic Stress
Authors: HAUGAN KETIL , OLSEN KRISTINE BOISEN , HARTVIG LINE , PETERSEN JØRGEN SØBERG , HOLSTEIN‐RATHLOU NIELS‐HENRIK , HENNAN JAMES K. , NIELSEN MORTEN SCHAK 
Published: May 2005

Objective: As atrial conduction slowing is important in the pathogenesis of atrial reentry arrhythmias, a drug that increases atrial conduction or prevents atrial conduction slowing could serve to prevent atrial reentry arrhythmias. In this study, we investigated whether the novel stable antiarrhythmic peptide analog, ZP123, was able to prevent atrial conduction slowing. Methods: We examined the effect of ZP123 on metabolic stress‐induced changes in conduction velocity (CV) and on dynamic CV restitution in isolated left atria from male Sprague‐Dawley rats. We performed binding of ZP123 to a broad panel of 80 different cardiac and noncardiac ion channels and receptors and examined the effect of ZP123 on HERG channel conductance. Results: ZP123 dose‐dependently prevented metabolic stress‐induced atrial CV slowing at doses ranging from 1 nM to 10 μM. ZP123 did not affect CV during physiological conditions nor did it affect dynamic CV restitution. ZP123 had no effect on atrial contractility. ZP123 showed no or low affinity binding to all ion channels and receptors examined. ZP123 had no effects on HERG channel activity in concentrations that affected atrial conduction. The concentration of ZP123 giving maximal effect on atrial conduction (100 nM) inhibited the outward K+‐current by 2.7 ± 0.1%. Conclusion: ZP123 has no effects on atrial conduction during physiological conditions, but it selectively prevents atrial conduction slowing during metabolic stress.
The role of dopamine in reward and pleasure behaviour – review of data from preclinical research
Authors: Bressan R. A. , Crippa J. A. 
Published: May 2005

Objective:  The purpose of this article is to review some of the basic aspects of the dopaminergic system and its role in reward and pleasure behaviour. We also discuss the association between dopamine and unpleasant symptoms that are commonly found in neuropsychiatric disorders and may also be side‐effects of neuroleptic drugs.Method:  A computer‐based search of the literature, augmented by extensive bibliography‐guided article reviews, were used to find basic information on the dopamine and the reward systems, and symptoms such as dysphoria, anhedonia and depression.Results:  Central dopaminergic neurotransmission is complex, having multiple actions at each level of the mesocorticolimbic reward pathway. The role of dopamine in the reward process was classically associated with the ability to experience pleasure; recent data suggest a more motivational role. Dysfunction of the dopamine transmission in the reward circuit is associated with symptoms such as anhedonia, apathy and dysphoria found in several neuropsychiatric disorders, including Parkinson's disease, depression, drug addiction, and neuroleptic‐induced dysphoria.Conclusion:  Viewing the dysfunctions of the reward pathways within a broader spectrum and exploring its complex relations with the dopaminergic transmission may help understand the pathophysiology of these neuropsychiatric disorders and lead to a rational development of novel treatments.
Brain imaging research on subjective responses to psychotropic drugs
Authors: Voruganti L. P. , Awad A. G. 
Published: May 2005

Objective:  Neuroimaging studies on subjective responses to psychotropic drugs in humans were reviewed to examine progress in the field and identify gaps in knowledge.Method:  An exhaustive search of computerized databases identified two categories of in vivo imaging studies: i) correlates of negative (dysphoric) subjective responses to neuroleptic use in schizophrenia, and ii) research on positive (euphoric) subjective responses, mostly from substance abuse population.Results:  Research has been largely confined to neurochemical imaging of dopamine in the striatal complex, confirming earlier speculations that impaired or deficient dopaminergic function is associated with dysphoric responses, and enhanced activity is associated with euphoric or pleasurable responses. Cerebral blood flow, regional metabolic rate and glucose utilization studies provided preliminary clues to the putative neuroanatomical sites.Conclusion:  Neuroimaging techniques added credibility to the study of subjective responses; however, further studies are required to identify the underlying anatomical and neurochemical interactions in order to enhance their applied value.
Adolescence, schizophrenia and drug abuse: a window of vulnerability
Authors: van Nimwegen L. , de Haan L. , van Beveren N. , van den Brink W. , Linszen D. 
Published: May 2005

Objective:  To discuss the neurobiological and psychosocial developmental factors in adolescence contributing to simultaneous onset and co‐occurrence of psychosis and substance use disorders.Method:  A review of the literature.Results:  Adolescence is a period with specific psychosocial challenges and specific changes in the brain that increase the probability of the onset of both psychosis and substance abuse, in predisposed people. In vulnerable adolescents it is proposed that an excessive pruning of dopaminergic neurones leads to mesocortical hypofrontality causing anhedonia and dysphoria. At the same time, anhedonia and dysphoria are important risk factors for the development of substance abuse. In turn, hypofrontality leads to a reduction in mesocortical feedback inhibition of the mesolimbic system resulting in aberrant salience and positive symptoms. Finally, the development of aberrant salience plays a role in both psychoses and craving.Conclusion:  Attention should be paid to the interaction of drug abuse and schizophrenia and an integrated treatment is needed. Dysphoria and anhedonia in schizophrenic adolescents are important factors in treatment with antipsychotic medication, both in terms of patient satisfaction and in the prevention of substance abuse.
Subjective experiences on antipsychotic medications: synthesis and conclusions
Authors: Marder S. R. 
Published: May 2005

Objective:  This report synthesizes the literature describing the phenomenology, clinical importance and biology of subjective responses to antipsychotic medications in schizophrenia. A patient's experience of an antipsychotic is important because unpleasant or dysphoric responses can impair therapeutic relationships, lead to medication non‐adherence, and have direct negative effects on a patient's quality of life.Method:  The author selectively reviewed early studies of subjective responses to antipsychotics and integrated this literature with the work of the other investigators in this special section.Results:  There is substantial evidence that second‐generation antipsychotics have advantages in causing fewer dysphoric responses when compared with first‐generation agents. Clinical and neuroimaging studies suggest that dopamine blockade is an important determinant of many of these dysphorias. At this point in time it is unclear whether dysphoria results from extrapyramidal symptoms – particularly akathisia and akinesia – or whether they are a direct result of decreased dopamine activity.Conclusion:  Clinicians and researchers should continue to monitor dysphorias in schizophrenia. Contributions by the authors in this supplement provide new and more refined methods for measuring subjective responses in future studies.
Reproductive Health and the Millennium Development Goals: The Missing Link
Authors: Crossette Barbara 
Published: May 2005

This report was commissioned by the Population Program of the William and Flora Hewlett Foundation in December 2004. The author was charged with analyzing the United Nations' deliberations that led to the adoption of the Millennium Development Goals (MDGs) to answer the question of why there is no specific reproductive health goal. Her report, of which this is a lightly edited version, is also available online at 〈;http://www.hewlett.org/programs/population/publications.crossettereport.htm〉.This coverage of the MDG process will be complemented by a special section of Studies in the June 2005 issue on reproductive health and the MDGs. The section will include excerpts about reproductive health from the final report of the Millennium Development Project entitled “Investing in Development: A Practical Plan to Achieve the Millennium Development Goals,” which was submitted to Secretary General Kofi Annan in January 2005, as well as commentaries by leading scholars and policymakers in the fields of population and reproductive health.
Analysis of Human Serum Immunoglobulin G againstO-Acetyl-Positive andO-Acetyl-Negative Serogroup W135 Meningococcal Capsular Polysaccharide
Authors: Giardina Peter C. , Longworth Emma , Evans-Johnson Renee E. , Bessette Michaelene L. , Zhang Hong , Borrow Ray , Madore Dace , Fernsten Philip 
Published: May 2005

ABSTRACTThe capsular polysaccharide ofNeisseria meningitidisserogroup W135 is expressed in bothO-acetyl-positive (OA+) andO-acetyl-negative (OA−) forms. This study investigates the impact of OA status (OA+versus OA−) on serological measurements of anti-W135 immunoglobulin G (IgG) antibodies in immunized adults. W135-specific serum antibody assignments were made for 28 postimmunization sera from adults by enzyme-linked immunosorbent assay using the meningococcal standard reference serum CDC1992. The established IgG concentration in micrograms per milliliter ([IgG]μg/ml) for CDC1992 against OA+antigen (16.2 μg/ml) was used as a reference to assign a concentration of 10.13 μg/ml IgG against OA−antigen by cross-standardization. Overall, the IgG assignments for these sera were higher against OA+antigen (geometric mean concentration [GMC] = 7.16 μg/ml) than against OA−antigen (GMC = 2.84 μg/ml). However, seven sera showed higher specific [IgG]μg/ml values against the OA+antigen than against the OA−antigen. These sera were also distinguished by the inability of fluid-phase OA−antigen to compete for antibody binding to OA+solid-phase antigen. Although there was no overall difference in functional activity measured by complement-mediated serum bactericidal assay (SBA) against OA+and OA−target bacteria (geometric mean titers of 9,642 and 9,045, respectively), three serum specimens showed a large difference in SBA antibody titers against OA+versus OA−W135 target bacteria, which may reflect different epitope specificities for these sera. Our data indicate that, for some sera, the agreement in anti-OA+versus anti-OA−W135 IgG assignments is serum specific and does not reflect the functional (killing) activity in vitro.
Comparison of a New Immunochromatographic Test to Enzyme-Linked Immunosorbent Assay for Rapid Detection of Immunoglobulin M Antibodies to Hepatitis E Virus in Human Sera
Authors: Chen Hsiao Ying , Lu Yang , Howard Teresa , Anderson David , Fong Priscilla Yiquan , Hu Wei-Ping , Chia Chee Poh , Guan Ming 
Published: May 2005

ABSTRACT

An immunochromatographic test for rapid detection of IgM antibodies in patients with acute hepatitis E infection was developed utilizing the well-characterized recombinant protein EP2.1 and monoclonal antibody 4B2. The new rapid test based on a novel reverse-flow technology was able to generate a positive result within 2 to 3 min. Our study showed that this test was able to detect anti-HEV IgM antibodies in 96.7% of the patient samples tested (
n
= 151) while maintaining an excellent specificity of 98.6% with samples from various patient or healthy control groups (total
n
= 208). Furthermore, this rapid test gave a good specificity of 90.9% when tested with rheumatoid factor (RF)-positive sera (RF value of ≤850 IU/ml;
n
= 11) although a higher concentration of RF in samples might cause cross-reactivity. The new test has a good agreement of 97.2% with a kappa value of 0.943 when compared with a reference enzyme-linked immunosorbent assay. The positive predictive value and the negative predictive value for the rapid test thus reached 98.0 and 97.6%, respectively. This is the first rapid, point-of-care test for hepatitis E and will be especially useful for the diagnosis of acute hepatitis E virus infection in field and emergency settings and in resource-poor countries.