Effects of ethanol volume percent on fluorescein-labeled spinach apo- and holocalmodulin

We report the effects of EtOH volume percent (0-70%) on spinach apo- and holocalmodulin that have been site-selectively labeled with fluorescein (F). In these experiments, calmodulin (CaM) has one F reporter group attached to Cys-26, and this site is located immediately adjacent to one of the four primary Ca(2+)-binding sites (EF hands). The optimum analytical CaM-F sensitivity to Ca2+ occurs between approximately 10 and 30% EtOH. Our results also show that added EtOH causes changes in CaM and these changes are surprisingly different for apo- and holo-CaM. Apo-CaM-F appears to lose one of its two waters of hydration at approximately 20% EtOH and retains one water of hydration between approximately 20 and 70% EtOH. In apo-CaM-F, the semiangle that describes the range over which the fluorescein reporter group can precess remains essentially constant (42 +/- 2 degrees) between 0 and 70% EtOH. This shows that the fluorescein reporter group precessional freedom in apo-CaM-F is not affected significantly by EtOH. Holo-CaM-F also appears to lose one water of hydration at approximately 20-30% EtOH but then appears to denature as the EtOH volume percent increases. The fluorescein reporter group semiangle within holo-CaM-F decreases from 43 +/- 1 degrees in neat aqueous buffer to 36 +/- 1 degrees at 70% EtOH. This shows that holo-CaM-F is less nativelike and the EF hand "closes down" about the fluorescein reporter group in holo-CaM-F as the EtOH volume percent increases.

Patients' understanding of and adjustment to epilepsy: interim findings from a European survey

The purpose of the study was to discover how much European patients with epilepsy and their carers understand about epilepsy. This article reports the interim results for the first four European countries recruited to the study and includes data collected from 1,920 people with epilepsy and 2,136 carers. Clinical and demographic details and data on understanding of epilepsy were collected using self-completed questionnaires mailed to members of epilepsy support groups. There were no significant differences between people with epilepsy and carers for scores on the Epilepsy Knowledge Questionnaire, although people with epilepsy were more likely to score in the higher ranges. Higher scorers on the questionnaire were more likely to be better educated, to have lower scores on the impact of epilepsy scales, to have higher scores on the adjustment to epilepsy scale, and were less likely to report feeling stigmatized. The study confirms the findings of previous studies that people with epilepsy are reasonably well informed, although some gaps in their knowledge were evident. A comparison of country differences will be made and multivariate statistical analysis will allow a better understanding of the contribution of knowledge to people's overall adjustment to their condition.

Cross-cultural differences in health-related quality of life of people with epilepsy: findings from a European study

PURPOSE

To examine between-country differences in health-related quality of life (HRQOL) of adults with epilepsy across a large number of European countries.

METHODS

Self-completion postal questionnaire sent to large sample of adults with epilepsy, recruited from epilepsy support groups or epilepsy outpatient clinics. The questionnaire was developed in English and translated. Back-translations from each language were checked for accuracy. The questionnaire sought information on clinical and socio-demographic details, and contained a number of previously validated scales of psychosocial well-being (the SF-36, the perceived impact of epilepsy scale, and a feelings of stigma scale).

RESULTS

Controlling for socio-demographic and clinical characteristics, significant between-country differences were found in scores on the perceived impact of epilepsy scale, on seven of the eight SF-36 domains, and on the feelings of stigma scale. Respondents in Spain and the Netherlands fared consistently better, whilst those in France fared poorest, compared to those in other countries in terms of the various HRQOL measures used.

CONCLUSION

Several possible reasons for the cross-cultural differences in HRQOL are proposed. Clearly, there is no single explanation and there may also be reasons which we have overlooked. This study emphasises the need for further comprehensive research in order that the position of people with epilepsy in different countries be more thoroughly understood in the social context.

The SF-36 as a health status measure for epilepsy: a psychometric assessment

A considerable literature is now available on the applications and psychometric properties of the MOS SF-36 Health Survey. In epilepsy, the SF-36 has been used as a health status measure in its own right and as the stem for two condition-specific measures. This paper replicates for epilepsy previous work to support use of the SF-36 across a range of clinical conditions. Data were obtained from a European-wide descriptive study of quality of life of adults with epilepsy; analysis of responses on the SF-36 is based on 4,929 subjects in eight countries. Missing value rates for all SF-36 items were low; percentages for whom complete information available for subscales ranged from 95.7% to 98.6%. All subscales passed tests for item-internal consistency and item-discriminant validity. Reliability coefficients exceeded the standard recommended for group comparisons across all subscales. Floor effects were negligible for all but the two role disability subscales; there were substantial ceiling effects for five of the SF-36 subscales. We conclude that the SF-36 is a valid and reliable health status measure for descriptive studies of people with epilepsy, but ceiling effects may limit its usefulness as an outcome measure in the assessment of new treatments.

Stress and avoidance in Pseudoseizures: testing the assumptions

Twenty women and 10 men with Pseudoseizures were matched by age and gender with an epilepsy- and a healthy-control group. In response to clinical and research evidence of a relationship between Pseudoseizures and the experience of stress, it was hypothesised that people with Pseudoseizures would perceive their ongoing lives as more stressful, and use more avoidant and distancing coping, and less problem-focused coping, than people in the two control groups. Using the Perceived Stress Scale (Cohen et al., J. Health Soc. Behav. 24, 1983, 385-396) and the Ways of Coping, revised version (Folkman and Lazarus, Manual for Ways of Coping Questionnaire, Consulting Psychologist Press, Paola Alto, CA, 1988) the study found that people with Pseudoseizures: (1) perceived their ongoing lives as significantly more stressful; (2) were significantly more likely to use a maladaptive (escape-avoidant) coping strategy; and (3) were significantly less likely to use an adaptive (planful problem solving) approach to coping than healthy controls. The study findings indicate that people with Pseudoseizures experience lives as stressful as do people with epilepsy, and are likely to employ maladaptive coping responses. Implications for diagnosis, intervention and future research are discussed.

Kinetics and thermodynamics of free flavins and the flavin-based redox active site within glucose oxidase dissolved in solution or sequestered within a sol-gel-derived glass

We report on the steady-state and time-resolved fluorescence from the redox active site flavine adenine dinucleotides (FADs) that are bound to glucose oxidase (GOx) when this enzyme is dissolved in aqueous solution or sequestered within a sol-gel-derived glass. To the best of our knowledge, this represents the first report on the actual dynamics of an enzyme active site when the enzyme is part of a sol-gel-derived glass. The results from these experiments show that the "free" FAD intramolecular folding/unfolding kinetics are slowed 3-10-fold within the glass vs solution. The intramolecular exciplex formation event (i.e., excited-state FAD residue folding/unfolding) is completely arrested for the GOx-bound FAD if the enzyme is sequestered within a glass in the absence of glucose. This is significantly different from the behavior of GOx dissolved in solution. However, despite this difference in behavior, the GOx molecules that are sequestered within the glasses continue to function somewhat like GOx dissolved in aqueous solution if they are challenged with glucose. We also found that the GOx molecules do not leach from the glass and they exhibit rotational mobility that is only 2-fold less than GOx dissolved in aqueous solution at 20 degrees C. In aqueous solution or within these glasses, the enzyme pocket that hosts the FAD redox sites opens up by 25-30% when GOx is challenged with glucose. Finally, we present preliminary analytical results for film-based sol-gel-derived biosensors that contain GOx, L-amino acid oxidase or cholesterol oxidase wherein the intrinsic FAD fluorescence produces the analytical signal.

The association of sexual and physical abuse with somatization: characteristics of patients presenting with irritable bowel syndrome and non-epileptic attack disorder

BACKGROUND

Physical symptoms are commonly presented for treatment in the absence of physical pathology. This study tests predictions arising from the theory that childhood sexual abuse leads to emotional distress, illness orientation and social dysfunction as adults and that one or more of these effects, in turn, leads to presentation of functional (i.e. unexplained) symptoms.

METHODS

Two groups of patients with physical symptoms in the absence of organic disease (non-epileptic attack disorder or irritable bowel syndrome) were contrasted with organically diseased groups with comparable symptoms (epilepsy and Crohn's disease, respectively).

RESULTS

Despite their contrasting clinical presentation, irritable bowel and non-epileptic attack groups were similar in recalling more sexual and physical abuse, as both children and adults, than their comparison groups. They were also similar in being more emotionally and socially disturbed and illness-orientated, but these putative mediating variables could not account for the relationship of abuse with presentation of functional symptoms.

CONCLUSIONS

Adults presenting functional neurological and abdominal symptoms are characterized by history of abuse. The current focus on childhood sexual abuse should be broadened to include sexual, and particularly physical, abuse in adulthood as well as childhood. The intervening processes that link abuse to somatization remain to be identified but are unlikely to include adult emotional and social disturbance or general illness-orientation.

Non-epileptic attack disorder (NEAD): a comprehensive review

Non-epileptic attack disorder (NEAD) represents a well-recognized clinical problem with a reported incidence among individuals with a diagnosis of intractable epilepsy as high as 36%. A failure to identify this disorder may lead to certain risks for the patient including polypharmacy, anticonvulsant toxicity, hazardous intervention, social and economic demands and a lack of recognition or neglect of any underlying psychological distress. This review provides a description of NEAD in an historic and societal context and discusses the variety of terminology which has been applied to this psychophysiological phenomenon. Epidemiology and associated methodological limitations; and diagnostic and classification issues related to NEAD in comparison to epilepsy are considered. The problems of failure to recognize NEAD in comparison to epilepsy are considered. The problems of failure to recognize NEAD are outlined, and theoretical and empirical aetiological issues are discussed.

Detecting the faking of amnesia: a comparison of the effectiveness of three different techniques for distinguishing simulators from patients with amnesia

This paper compared the effectiveness of three different procedures that have been put forward as possible ways of distinguishing patients with genuine memory problems from those who are attempting to simulate amnesia. The performance of 20 patients with amnesia was compared with the performance of 20 normal control individuals and 20 normal individuals who had been asked to simulate amnesia on the distraction/no distraction test (Baker, Hanley, Kimmance, & Slade, 1993), the coin-in-the-hand test (Kapur, 1994) and word fragment completion (Horton, Smith, Barghout, & Connolly, 1992). The distraction/no distraction test and the coin-in-the-hand test both proved successful in distinguishing patients with amnesia from simulators (p < .01). Excellent performance by virtually all patients with amnesia coupled with chance or below chance performance by 19/20 simulators on the coin-in-the-hand test was particularly striking. Consistent with the results of Horton et al. ( 1992), the word fragment completion test successfully discriminated between the performance of simulators and controls (p < .01). However, the fragment completion test proved incapable of distinguishing between the performance of patients with amnesia and simulators (p > .05). It is argued that there may be problems inherent in the use of tests designed to investigate implicit memory in attempts to detect malingering.

Neuropsychological outcomes in randomized controlled trials of antiepileptic drugs: a systematic review of methodology and reporting standards

PURPOSE

To systematically review the methodology and use of neuropsychological tests in randomized controlled trials (RCTs) of antiepileptic drugs (AEDs) in patients with epilepsy.

METHODS

Trial reports were found by searching Medline 1966-1996 and searching through journals by hand. Inclusion and exclusion criteria were applied, and methodological and neuropsychological test data was extracted by using a proforma.

RESULTS

43 reports met our inclusion criteria, representing 40 RCTs. as three RCTs had generated two reports. Twenty-two were actively controlled, and 18 were placebo-controlled studies. Reporting of basic methods such as randomization method was poor. There has been no uniform approach to the use of neuropsychological tests, and a total of 87 has been used. The Stroop Colour Word Test and the Finger Tapping Test were most commonly used, at 13 times each, but were not used or reported in a uniform manner.

CONCLUSIONS

Poor reporting of methods and the use of a plethora of neuropsychological tests create great difficulties for anyone wishing to make sense of currently available data. If we are better to understand the neuropsychological effects of AEDs, a more rational approach is needed, for which recommendations are made.

A parallel multiharmonic frequency-domain fluorometer for measuring excited-state decay kinetics following one-, two-, or three-photon excitation

We report on the performance of a new, multiharmonic frequency-domain instrument that uses the high harmonic content of a passively mode-locked, pulse-picked femto-second Ti-sapphire laser as the excitation source for the determination of one-, two-, or three-photon excited time-resolved fluorescence anisotropy and intensity decay kinetics. In operation, the new instrument can provide a complete frequency-domain data set at 100 modulation frequencies in less than 1 min. The new instrument exhibits 5-10-ps measurement precision and it can rapidly and accurately recover complex excited-state fluorescence anisotropy and intensity decay kinetics under one-, two-, or three-photon excitation for dilute or optically dense samples that exhibit single or multiexponential decay kinetics. This latter aspect of the instrument is demonstrated by successfully determining the excited-state intensity decay kinetics for a dilute aqueous solution of rhodamine 6G dissolved in a high concentration of bromocresol green. This approach is extended by determining the excited-state fluorescence intensity decay kinetics of dilute fluorescein directly in undiluted, whole blood as a function of pH under two-photon excitation conditions. The high-speed capabilities of the new instrument are exploited by performing two-photon excited fluorescence anisotropy decay experiments on the fly for site-selectively labeled bovine serum albumin as it undergoes enzymatic digestion by trypsin.

Unfolding of acrylodan-labeled human serum albumin probed by steady-state and time-resolved fluorescence methods

Steady-state and time-resolved fluorescence spectroscopy was used to follow the local and global changes in structure and dynamics during chemical and thermal denaturation of unlabeled human serum albumin (HSA) and HSA with an acrylodan moiety bound to Cys34. Acrylodan fluorescence was monitored to obtain information about unfolding processes in domain I, and the emission of the Trp residue at position 214 was used to examine domain II. In addition, Trp-to-acrylodan resonance energy transfer was examined to probe interdomain spatial relationships during unfolding. Increasing the temperature to less than 50 degrees C or adding less than 1.0 M GdHCl resulted in an initial, reversible separation of domains I and II. Denaturation by heating to 70 degrees C or by adding 2.0 M GdHCl resulted in irreversible unfolding of domain II. Further denaturation of HSA by either method resulted in irreversible unfolding of domain I. These results clearly demonstrate that HSA unfolds by a pathway involving at least three distinct steps. The low detection limits and high information content of dual probe fluorescence should allow this technique to be used to study the unfolding behavior of entrapped or immobilized HSA.

Liverpool Seizure Severity Scale revisited

The purpose of the study was to examine the psychometric properties of the revised Liverpool Seizure Severity Scale. The scale has been adapted to increase its content validity and its potential for detecting change attributable to antiepileptic drug treatment. Ninety-seven patients completed the revised scale of which 32 completed it for both major and minor seizures. Reliability of the revised scale was conducted using assessment of internal consistency and test-retest. T-tests were conducted to assess the ability of patients to differentiate between major and minor seizures on scores of the seizure-severity scale. The psychometric properties of the scale were not adversely affected by either the increase in the number of items or the additional response scores. Patients completing the two scales of major and minor seizures were able to reliably differentiate between the two. We have attempted to improve the Liverpool Seizure Severity Scale in order to enhance its reliability, validity and sensitivity to change. The amendments we have made have not adversely affected its psychometric properties and we hope that it will make it more acceptable for use in clinical trials of new antiepileptic drug treatment. The revised scale is currently being applied to a number of clinical trials.

Quality of life and epilepsy: the Liverpool experience

The use of quality of life (QOL) measures in epilepsy research is relatively recent compared with that in other chronic conditions such as coronary heart disease and diabetes. However, in recent years much research has been undertaken to develop and validate QOL measures for use in various groups of people with epilepsy, including children, the elderly, and newly diagnosed patients. QOL measures are now available for use in both clinical trials and primary care. The Liverpool Group is one of the leading research teams in this field and is probably best known for developing the Liverpool Seizure Severity Scale. However, the group has also developed a number of other QOL measures, with an emphasis on keeping the measures appropriate, practical, and responsive, and always considering the burden to patients. This review describes some of the measures the Liverpool Group has developed, outlines their application in clinical trials of a number of aspects of antiepileptic drugs, and details the importance of some of the findings. The diversity of the group's approach and of its involvement in assessing the QOL of people with epilepsy are emphasized.

The relationship between seizure frequency, seizure type and quality of life: findings from three European countries

Understanding the relationship between seizure frequency, seizure type and scores obtained from quality of life (QOL) measures is important if the incorporation of QOL measures into epilepsy clinical trials is to become standard practice. There is also a need to consider cross-cultural differences obtained from QOL measures, particularly in the context of multicentre international trials. In this study, 300 patients recruited from UK, Germany and France completed the Functional Status Questionnaire (FSQ); information about patients' clinical and demographic status was also collected. Results from the study highlighted that seizure type and seizure frequency, as well as country of origin, were significant predictors of scores on the FSQ. It is important to measure the effect of seizure type, not just seizure frequency, on QOL when testing for differences between antiepileptic therapies in the context of clinical trials.

Simulating a memory impairment: can amnesics implicitly outperform simulators?

OBJECTIVES

The purpose of this study was to examine the effectiveness of a variety of tests in differentiating simulating test performances from genuine memory-impaired and normal (control) test performances.

DESIGN

A simulation design was implemented, based on an analogue design in which normal participants were given experimental instructions to feign a mental impairment and are compared to (a) other normal participants with instructions to perform honestly, and (b) a comparison group, for example, acquired brain-injured persons, with similar instructions.

METHOD

Forty individuals comprised the simulating and control group and all participants were randomly assigned to the simulating and control groups. Twenty memory-impaired patients, all of whom had been diagnosed as suffering from a memory impairment following acquired brain damage, participated as the memory-impaired control group. The simulation group was directed to imitate a person with a memory impairment. The primary outcome measure involved identifying those tests, if any, where simulators were significantly different from normal and memory-impaired participants.

RESULTS

On 5 of the 15 tasks administered, simulators performed significantly differently from normal and memory-impaired participants. Of these 5 tasks, the coin-in-the-hand, when administered in conjunction with the autobiographical interview, identified 95 per cent of the simulators without misclassifying any of the memory-impaired or normal participants.

CONCLUSION

It is suggested that these two tests, when administered jointly, might be of use in clinical settings to assist in the detection of malingerers.

Health-related quality of life after transient ischemic attack and minor stroke: Is medical or surgical treatment influential?

Although randomized trials have proven the benefit of carotid endarterectomy (CEA) for appropriate patients, health care purchasers increasingly look beyond clinical outcome toward measures of cost effectiveness and health-related quality of life (HRQoL) in apportioning limited resources. We used a generic HRQoL outcome scale, the Short Form 36 (SF-36), to assess the differences in patient-perceived HRQoL in two cohorts of patients who had suffered minor cerebral ischemic events. One group (n=100) had undergone CEA, whereas members of the second cohort (n=100) were not appropriate candidates for surgery and were therefore treated with best medical therapy. The overall response rate was 83%. No significant difference in health profile between the CEA and medical cohorts was detected for the eight SF-36 domains. However, the CEA cohort rated a significantly improved change in general health over the previous year compared with the group managed medically (P<.01). A greater proportion of the former group than of the medical group thought their treatment had been successful and that their health had been improved by treatment (P<.01). Both groups shared the same anxieties over future cerebral ischemic events (P=.3). Patients' perception of HRQoL measured by the SF-36 domains was almost identical between the CEA and medical cohorts apart from a small but significant improvement in self-reported overall health in the CEA cohort. HRQoL outcome measures may be of value in future clinical trials of cerebral revascularization.

Non-epileptic attack disorder: a psychological perspective

Due to the serious medical consequences in failing to recognize non-epileptic attack disorder (NEAD), and the frequency with which neurologists come into contact with such patients, clearly NEAD constitutes a major concern for clinicians in the field of epilepsy. This article presents the psychological characteristics of 185 patients with NEAD. Psychological factors that were identified as being important in the understanding of the development and maintenance of NEAD included: anxiety or stress; physical abuse; significant bereavement; family dysfunctioning; relationship problems; depression; sexual abuse. An absence of relevant psychological factors was found in only 5% of patients. From patients' descriptions of their attacks, it appears that many symptoms are related to anxiety. Our findings are largely supported by previous studies and their relevance to effective management and treatment of NEAD patients is discussed.

Psychometric properties and factor structure of the Wechsler Memory Scale-Revised in a sample of persons with intractable epilepsy

The Wechsler Memory Scale-Revised (WMS-R) is used routinely as a presurgical assessment of memory for clients considering elective resection of the temporal lobe and/or hippocampus for the relief of intractable temporal lobe epilepsy. This research investigated the psychometric properties of the WMS-R in a population of people with epilepsy. The sample consisted of 181 patients with a diagnosis of epilepsy who underwent a complete neuropsychological examination as a routine part of their investigation. The results confirm that the WMS-R has acceptable levels of reliability as measured by internal consistency. A factor analysis revealed a consistent three-factor structure: Visual Memory, Verbal Memory, and Attention/ Concentration factors. Multiple regression analysis, however, indicated that the Visual Memory index was susceptible to a number of influences, throwing into question whether it is a pure measure of nonverbal memory functioning.

Behavioral and cognitive effects of lamotrigine

Lamotrigine is a new antiepileptic drug that may possess unique cognitive and behavioral characteristics. Although lamotrigine can produce neurobehavioral toxicity, it is generally well tolerated. In one study directly comparing lamotrigine to placebo as add-on therapy in patients with intractable epilepsy, no objective cognitive effects were observed in a limited neuropsychological battery. Several studies have demonstrated favorable effects of lamotrigine on psychological well-being that were not explained by simple effects on seizure frequency and severity. In direct comparisons with carbamazepine and phenytoin, lamotrigine has been reported to produce positive effects on quality of life scales of patient perception. In addition, positive behavioral effects have also been observed in two blinded studies and several open trials for patients with severe mental disability and refractory epilepsy. Future studies with more extensive neuropsychological assessments are needed to delineate the differential cognitive and behavioral effects of lamotrigine in epilepsy and psychiatric disorders.