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Biomedical subjects

T Roth

Publications and source records attributed to T Roth.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effects of zaleplon or triazolam with or without ethanol on human performance.

Objectives and background: Given that non-selective gamma-aminobutyric acid (GABA) agonist hypnotics impair performance and potentiate the disruptive effects of ethanol, this study was done to determine the performance-impairing and ethanol-potentiating effects of zaleplon, a new selective GABA agonist hypnotic.Methods: Eighteen healthy men (12) and women (six), 31.5+/-5.6 years old, were studied. Each underwent six treatments of 2 days in duration, presented in a Latin square design with 2-12 recovery days between. The treatments were: placebo-placebo; placebo-ethanol; triazolam-placebo; triazolam-ethanol; zaleplon-placebo; and zaleplon-ethanol; with triazolam (0.25 mg) or placebo administered at 08:30 h, zaleplon (10 mg) or placebo at 09:00 h, and ethanol (0.75 g/kg) or placebo consumed from 09:30 h. Performance tests were completed each day at 10:30, 12:00 and 14:30 h.Results: Breath ethanol concentration (BrEC), tested 0.5, 2.0, 4.5 and 6 h post consumption, did not differ among treatments and peaked at 0.052%, declining to 0.037, 0.009 and 0.001%. Triazolam with and without ethanol impaired digit symbol substitution, symbol copying, simple and complex reaction times and divided attention performance relative to placebo-placebo treatment. It did so consistently at 10:30 and 12:00 h, and less consistently at 14:30 h. Zaleplon without ethanol impaired only digit symbol substitution and divided attention tracking, and only at 10:30 h. Zaleplon with ethanol impaired most measures at 10:30 and 12:00 h, but not at 14:30 h. Zaleplon without ethanol consistently differed from triazolam without ethanol in the extent of performance impairment. Zaleplon with ethanol began to differ from triazolam with ethanol in performance impairment on the 12:00 and 14:30 h test sessions. Ethanol itself impaired most measures at 10:30 h, fewer at 12:00 h and none at 14:30 h. All active drug treatments increased self-rated sleepiness compared with placebo-placebo. Triazolam without ethanol produced greater self-rated sleepiness than zaleplon without ethanol. The addition of ethanol to both drugs generally produced comparable levels of self-rated sleepiness.Conclusions: In an absolute sense, zaleplon produced less performance impairment and a shorter period of ethanol potentiation than triazolam.

Journal Article↗
PubMed2001

Sleep and cognitive (memory) function: research and clinical perspectives.

The field of memory and sleep is controversial and extremely interesting, and the relationships between thought processes, i.e. cognition and sleep, have recently been examined in a variety of clinical and basic research settings, as well as being the object of intense interest by the general public. For example, there are data which demonstrate that insomnia, as well as specific sleep disorders, can have a negative impact on sleep cognition as well as affect daytime patterns of cognitive functioning. Thus, sleep, disturbed sleep and the lack of sleep appear to affect cognitive and memory functions. An International Workshop dealing with Sleep and Cognitive Function: Research and Clinical Perspectives was convened in Cancún, Mexico, 1-4 March 1999 under the auspices of the World Health Organization Worldwide Project on Sleep and Health and the World Federation of Sleep Research Societies. A great number of areas of intersection between sleep and cognitive function were examined during the course of the Workshop, such as aging, cognition and sleep and the dream process and sleep. The results of these discussions are included in a WHO publication (WHO Doc.: MSD/MBD/00.8). In the present report we concentrate on presenting a summary of a coherent set of data which examine memory consolidation during sleep and the impact of insomnia on cognitive functions. Based upon these data, a review of memory and drug effects that are sleep-related, and an examination of the relationship between hypnotics and cognitive function are included. Finally, a summary of recommendations of the Workshop participants is presented.

Journal Article↗
PubMed2001

Effects of rapid versus slow accumulation of eight hours of sleep loss.

The present study assessed alertness, memory, and performance following three schedules of approximately 8 hr of sleep loss (slow, intermediate, and rapid accumulation) in comparison to an 8-hr time in bed (TIB) sleep schedule. Twelve healthy individuals aged 21-35 completed each of four conditions according to a Latin Square design: no sleep loss (8-hr TIB for 4 nights; 2300-0700), slow (6-hr TIB for 4 nights; 0100-0700), intermediate (4-hr TIB for 2 nights; 0300-0700), and rapid (0-hr TIB for 1 night) sleep loss. On each day, participants completed a multiple sleep latency test (MSLT), a probed-recall memory task, a psychomotor vigilance task, a divided attention task, and the Profile of Mood States. "Rapid" sleep loss produced significantly more impairment on tests of alertness, memory, and performance compared to the "slow" accumulation of a comparable amount of sleep loss. The impairing effects of sleep loss vary as a function of rate, suggesting the presence of a compensatory adaptive mechanism operating in conjunction with the accumulation of a sleep debt.

Adult↗
PubMed2001

The relationship between psychiatric diseases and insomnia.

Sleep difficulties affect about one-third of American adults, yet these symptoms are not often addressed by patients and their physicians. Unresolved insomnia that impairs daytime function may be associated with significant psychiatric morbidity, predominantly major depression. Clinicians who are aware that these disorders frequently co-exist will be able to facilitate prompt diagnosis and initiate appropriate pharmacotherapeutic intervention. Antidepressant therapies may interfere with sleep quality; therefore, the management of insomnia in depressed patients should be addressed separately. Traditionally, benzodiazepines have been prescribed to treat sleep disturbances, but certain drugs in this class have limited benefits due to residual sedative effects that impair cognitive function, memory and general daytime performance. Zaleplon, a new, quick-acting, non-benzodiazepine sleep medication, may be clinically advantageous in promoting sleep without residual impairment.

Acetamides↗
PubMed2001

Future directions in the management of insomnia.

Research on insomnia has provided a number of important new insights, but fundamental deficits in our understanding remain. In considering priorities for future research, 3 areas warrant immediate attention. First, a causal relationship between insomnia and the adverse outcomes seen in insomnia patients needs to be established. Second, currently available symptomatic therapies need to be optimized. Recent data suggest that some benzodiazepine receptor agonists produce their hypnotic effect without side effects that were presumed to be inherent to sedation. Understanding the neuropharmacology underlying this differential effect would allow substantial improvements in the risk-benefit ratio for these drugs. Finally, the mechanisms of insomnia need to be better understood. Several lines of evidence suggest that physiologic arousal is important to the clinical presentation of primary insomnia. It remains unclear, however, whether this activation is primary or secondary to the insomnia itself. If physiologic hyperarousal causes primary insomnia, it would provide new approaches to the management of this disorder.

Comorbidity↗
PubMed2001

Sleep, sleepiness, and alcohol use.

The study of alcohol's effects on sleep dates back to the late 1930s. Since then, an extensive literature has described alcohol's effects on the sleep of healthy, nonalcoholic people. For example, studies found that in nonalcoholics who occasionally use alcohol, both high and low doses of alcohol initially improve sleep, although high alcohol doses can result in sleep disturbances during the second half of the nocturnal sleep period. Furthermore, people can rapidly develop tolerance to the sedative effects of alcohol. Researchers have investigated the interactive effects of alcohol with other determinants of daytime sleepiness. Such studies indicate that alcohol interacts with sleep deprivation and sleep restriction to exacerbate daytime sleepiness and alcohol-induced performance impairments. Alcohol's effects on other physiological functions during sleep have yet to be documented thoroughly and unequivocally.

Alcohol Drinking↗
PubMed2000

Eight weeks of non-nightly use of zolpidem for primary insomnia.

CONTEXT: Intermittent use (i.e., a few nights per week) of hypnotic medication is often recommended for the treatment of chronic insomnia despite an absence of efficacy and safety data using this regimen. STUDY OBJECTIVES: To evaluate the clinical efficacy and safety of intermittent pharmacotherapy for chronic insomnia. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled, parallel groups, clinical trial at six sleep research sites. PATIENTS: One hundred-sixty-three (115 women, 48 men; mean age 44.1+ SE. 0.9 years), DSM-IV-defined primary insomnia patients were randomized, 134 patients completed the study. INTERVENTIONS: Eight weeks of treatment with either zolpidem 10 mg or placebo. Patients were instructed to take medication when they felt they needed it, but at least three and no more than five times per week. MAIN OUTCOME MEASURES: Investigator and Patient Global Ratings were the primary outcome variables. Secondary measures from daily questionnaires to assess efficacy, rebound insomnia and drug taking behavior. RESULTS: The Investigator's Global Rating indicated that intermittent use of zolpidem produced a significantly better therapeutic effect and significantly reduced insomnia severity throughout the 8-week study relative to placebo. Zolpidem was found to be effective in initiating and maintaining sleep on nights taken, as compared to placebo, based upon the Patient's Global Ratings and all subjective sleep variables. No evidence of rebound insomnia was found on nights that zolpidem was not taken. The number of nights a pill was taken did not differ between groups, nor did frequency of pill taking change in either group across the duration of the study. There were no significant effects of treatment upon quality of life or neurocognitive measures. CONCLUSIONS: Zolpidem 10 mg is effective in treating insomnia when used intermittently, without evidence of discontinuation effects or increased frequency of pill taking.

Analysis of Variance↗
PubMed2000

Observation of magnetoelectric jones birefringence

In 1948, Jones showed that uniaxial media can in general show four different fundamental optical phenomena, each of which can appear in refraction and absorption. Three of these are well established: isotropic refraction and absorption, linear birefringence and dichroism, and circular birefringence and dichroism. The fourth effect, predicted by Jones, has remained unobserved so far. In this Letter, we report the first experimental observation of this missing fourth, so-called Jones effect, as an additional, tilted linear birefringence. In our experiments, this effect was induced in liquids by parallel external magnetic and electric fields perpendicular to the propagation direction.

Journal Article↗
PubMed2000

Scoring reliability of the multiple sleep latency test in a clinical population.

STUDY OBJECTIVES: To determine intrarater and interrater scoring reliability of the multiple sleep latency test (MSLT) in a population of sleep clinic patients. DESIGN: N/A. SETTING: Urban sleep center. PATIENTS: 200 consecutive sleep center patients (diagnoses included: obstructive sleep apnea, narcolepsy, periodic-limb-movement, and individuals with no diagnosis). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: MSLTs were recorded and scored according to standard clinical procedures. One of four clinical polysomnographers and one of seven polysomnographic technologists scored each MSLT. All MSLTs were then rescored by the same polysomnographer. The intrarater reliability coefficient for mean MSLT score was .87 and interrater reliability was .90. Coefficients for the mean number of REM onsets during the MSLT were .81 for intrarater and .88 for interrater reliability. Intrarater and interrater agreement (kappa coefficients) for the presence of at least one REM onset during the MSLT was .78 and .86, respectively. For the presence of greater than one REM onset, a kappa of .78 was obtained for intrarater agreement and .91 for interrater agreement. CONCLUSIONS: The clinical MSLT displays excellent interrater and intrarater reliability estimates for both sleep latency and REM onset scores in a sleep-disordered population.

Adolescent↗
PubMed2000

Effects of sleep loss on waking actigraphy.

STUDY OBJECTIVES: To assess the effect of sleep loss and the effect of a sedating drug on waking actigraphy DESIGN: N/A SETTING: N/A PARTICIPANTS: Seventeen healthy volunteers, aged 19-35 yrs INTERVENTIONS: Four night-day treatments presented in a Latin Square Design: placebo-8 hr time-in-bed (TIB), placebo-4 hr TIB, placebo-0 hr TIB, and diphenhydramine 50 mg-8 hr TIB. MEASUREMENTS AND RESULTS: After the appropriate TIB, medication was administered at 09:00 hr, the Multiple Sleep Latency Test at 09:30, 11:30, 13:30, 15:30, and 17:30 hr, and a 45 min performance battery at 10:30, 14:30, and 16:30 hr. Each day the volunteers wore actigraphs from 0700-1800 hrs. Decreasing TIB was associated with decreased daily mean sleep latency on the MSLT with 4 and 0 hrs differing from 8 hrs and each other. Daytime activity also was reduced by the reduced prior TIB. Increased inactivity relative to the 8 hr TIB developed between the 4 hr and 0 hr TIBs, with 4 hrs differing from 0 hrs, but not 8 hrs. Diphenhydramine 50 mg reduced mean daily sleep latency and increased percent inactive time relative to placebo. On the MSLT diphenhydramine was intermediate to 4 hr and 0 hr TIB and on actigraphy it was similar to 0 hr TIB. CONCLUSIONS: The difference in the effect of diphenhydramine on these actigraphy and MSLT may reflect the different sensitivities of the measures.

Adult↗
PubMed2000

Novel precursors of solvated electrons in water: evidence for a charge transfer process.

Femtosecond midinfrared spectroscopy of water (heavy water) after two photon excitation at 9 eV provides clear evidence for two short-lived precursors of the hydrated electron preceding the well-known "wet electron." The measured first intermediate with peak absorption at 2.9 (4.1) microm is proposed to represent an O(H, D):e(-) complex. The subsequent solvation proceeds via e(-):[(H, D)2O](n) complexes at approximately 1.6 (2.0) microm in the electronic ground state, involving an increasing number of water molecules during the first 200 fs and followed by the wet electron.

Electrochemistry↗
PubMed2000

CPAP therapy in patients with mild OSA: implementation and treatment outcome.

Objectives: To determine continuous positive airway pressure (CPAP) treatment compliance and reversal of excessive daytime sleepiness in patients with mild OSA.Background: CPAP therapy is the most widely accepted and used intervention in patients with a diagnosis of obstructive sleep apnea (OSA). There are, however, no widely accepted protocols to help guide the rational use of CPAP therapy. Patients with mild OSA (respiratory event index (REI) >5 or </=25) represent a subset of the OSA population where CPAP implementation needs to be evaluated.Methods: This is a retrospective study of 740 consecutive patients evaluated for sleep apnea in 1996. Mild OSA was documented in 241 patients, of whom, 41 opted for CPAP therapy. Implementation of CPAP treatment included an education session and an overnight clinical polysomnography (CPSG) for titration purposes. Patients returned for follow-ups after 1 week and 1 year of CPAP use. During each appointment, compliance and response to treatment were evaluated.Results: Of the initial 41 patients nine were lost to follow-up, 16 discontinued CPAP use during the first week, and 16 were still using CPAP after 1 year. For the 16 still using CPAP after one year, hours of use the first week was correlated to hours of use the first year (r=0.81). Patients using CPAP more than 4 h/night experienced a marked improvement in daytime sleepiness after 1 year (P<0.01).Conclusions: Patients with mild OSA showed a high rate of CPAP discontinuation. Those patients who manifested good compliance during the first week of treatment continued using CPAP for the entire first year. These patients experienced improved alertness during the day. A 1 week trial on CPAP therapy is warranted to identify patients who benefit from this form of therapy.

Journal Article↗
PubMed2000

Sleep and health: research and clinical perspectives.

Overall, the Workshop covered most of the principal areas which will be the focus of the Worldwide Project on Sleep and Health. Presentations ranged from the basic science of melatonin receptors to the epidemiology of untreated insomnia, and finally, to the education of primary care physicians. It was emphasized that there is a need for more data, and new experimental paradigms are necessary for successful public health initiatives dealing with sleep disorders.

Circadian Rhythm↗
PubMed2000

Sleep-wake state and memory function.

Facility of memory formation and retrieval is affected by sleep-wake state. This paper discusses memory function while individuals are awake, but sleepy, at the transitions in state (i.e., wake to sleep and sleep to wake), and in REM and NREM sleep. The basal state of arousal at the time of memory function seems to be critical and the sleepy state, state transitions, and NREM sleep seem to define a continuum of arousal with respect to memory function. While different memory systems have been described, the effect of sleep-wake state on memory systems appears to be non-specific. Finally there is a shift in neurobiology from the NREM to REM state and memory function also appears to change in REM sleep.

Disorders of Excessive Somnolence↗
PubMed2000

Effects of sleep deprivation on daytime sleepiness in primary insomnia.

STUDY OBJECTIVES: This study investigated changes in MSLT scores and recovery sleep following total sleep deprivation in subjects with insomnia as compared to normal sleepers. DESIGN: Matched-groups design. SETTING: A sleep disorders center in a large medical center. PARTICIPANTS: Ten individuals with psychophysiological insomnia and ten age- and sex-matched normal sleepers served as subjects. INTERVENTIONS: Subjects underwent total sleep deprivation after baseline polysomnography and MSLT. A post-deprivation MSLT was obtained, as well as polysomnography on the recovery night and an MSLT after the recovery night. MEASUREMENTS AND RESULTS: Both groups showed significant decreases in MSLT scores following total sleep deprivation, as compared to baseline. Both groups had significantly shorter scores on a nighttime MSLT compared to a daytime MSLT. The insomnia group also showed a significant increase in total sleep time on the recovery night compared to baseline. CONCLUSIONS: The MSLT is sensitive to changes in sleepiness associated with total sleep deprivation in individuals with primary insomnia.

Adult↗