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Biomedical subjects

D Kripke

Publications and source records attributed to D Kripke.

9 recordsLinked to original sources
PubMed2005

Associations of ambient illumination with mood: contribution of ophthalmic dysfunctions.

Evidence suggests that ocular pathology could reduce light-stimulated neuronal signaling to the suprachiasmatic nuclei. This study investigated associations of ambient illumination with moods, while considering the contribution of ophthalmic dysfunctions. Seventy Black (59%) and White (41%) Americans participated in the study. Their average age was 68.27+/-5.97 years; 73% were women. Baseline data included: physical health, mood, and sociodemographics. Ophthalmic factors including visual acuity, visual field defects, intraocular pressure, vertical and horizontal cup-to-disk ratios, and nerve-fiber-layer thickness were assessed at SUNY Downstate's eye clinic. The following week, participants wore the Actiwatch-L at home to monitor ambient illumination and sleep. Cosine analyses were performed on the logarithm of measured illumination, yielding the mesor and acrophase of daily illumination exposure. Sleep was estimated with an automatic scoring algorithm. Of the sample, 25% reported visual impairment and 85% reported good to excellent health; 27% were visually impaired according to American criteria. Partial correlation analyses showed an inverse correlation of daily illumination levels to depressed mood [r(p)=-0.33, P<0.05], when age, sex, ethnicity, income, BMI, diabetes, hypertension, respiratory disease, and habitual sleep duration were controlled. With further control for ophthalmic factors, the magnitude and significance of the correlation diminished [r(p)=-0.26, NS]. Individuals receiving daily illumination later in the day reported more depressed moods [r(p)=0.36, P<0.01]; of note, this correlation was not significant after control for the covariates [r(p)=0.18, NS]. Regression analysis indicated that the ophthalmic factors explained 13% of the variance in depression. Our results show that both the level and timing of ambient illumination are associated with mood. Furthermore, they suggest that visual impairment has a mediating effect on the associations of ambient illumination with depression, supporting the notion that ocular pathology lessens the efficacy of daily illumination in promoting positive moods.

Affect↗
PubMed1990

Clinical safety of flurazepam and midazolam during 14-day use in chronic insomniacs.

Data from evening questionnaires, reports of side effects, laboratory findings, and all-night respiratory measurements were collected on the 99 chronic insomniacs examined in this multicenter study. These data were used to compare the clinical safety and desirability of a benzodiazepine hypnotic with a very short half-life, midazolam 15 mg, with a hypnotic with a longer half-life, flurazepam 15 and 30 mg; both compounds were compared with a placebo control. There were 2 prestudy placebo nights followed by 14 consecutive nights of treatment. Of the 107 patients accepted, 99 completed the study. No marked adverse reactions were found in any area for any group. There was no increase in sleep apneas during the treatment period for any group. Results of this study provide additional evidence of the safety of benzodiazepine hypnotics.

Adult↗
PubMed1988

The use of triazolam in phase-advanced sleep.

The need for optimal nocturnal performance continues to increase in our society. Nighttime function is dependent upon the ability to sleep effectively during the day. The current study examined daytime sleep after placebo, 0.125 mg (364 nmol), 0.25 mg (729 nmol), or 0.50 mg (1458 nmol) of triazolam, and nocturnal performance in the work shift that followed. Forty-one normal young adult subjects participated in a repeated-measures design in which each subject received each medication dose level in a separate week. The results indicated that day sleep increased as a linear function of drug dose from 234 to 374 minutes. Nocturnal alertness, as measured by subjective report and objective nap latency test, increased significantly following the use of triazolam, 0.25 and 0.50 mg, for the day sleep period. Nocturnal performance, as measured by auditory vigilance and additions, also increased significantly following the use of triazolam. Marginal evidence for medication hangover was found at the 0.50-mg dose, and it was therefore recommended that the use of the 0.50-mg dose be monitored carefully if performance demand were to follow medication use by less than 12 hours. The results for the study were interpreted as indicating that under certain conditions, triazolam could effectively increase daytime sleep and improve alertness and performance in the following nocturnal work period.

Adult↗
PubMed1985

Cheyne-Stokes breathing during sleep in patients with left ventricular heart failure.

Fifteen patients with left ventricular heart failure (LVF) without known breathing disorders during sleep had full-night recordings of sleep and breathing to study the incidence and impact of the apnea of Cheyne-Stokes breathing. This group showed a marked degree of sleep-related breathing abnormalities, 40% demonstrating Cheyne-Stokes breathing with five or more central apneas per hour of sleep. Cheyne-Stokes breathing during sleep in patients with LVF predicted an increased short-term mortality rate. All six patients with LVF and Cheyne-Stokes breathing with more than five apneas per hour of sleep were dead within six months, while only three of nine patients without recurrent apnea died within six months, a significant difference (P less than .05) even in this small group. Among seven patients with LVF studied with the polysomnogram, there were statistically significant differences between the Cheyne-Stokes and non-apnea groups in total sleep time, awakening per hour, and the number of arterial desaturations. Although sleep disturbances have been anecdotally described in patients with LVF, no previous investigation has determined the incidence and impact of Cheyne-Stokes breathing during sleep in LVF. Our findings that Cheyne-Stokes breathing predicts an adverse short-term mortality rate confirm the clinical impression that Cheyne-Stokes breathing is a poor prognostic sign in LVF.

Adult↗
PubMed1980

Flurazepam effects on methylphenidate-induced stereotyped behavior.

The effects of flurazepam (0.0, 0.5, and 3.0 mg/kg) on methylphenidate-induced increases in stereotypy, gnawing, sniffing, and locomotion were evaluated in Swiss-Webster mice in daytime and nighttime experiments. Methylphenidate (50 mg/kg) increased overall stereotypy and stereotyped gnawing behavior; two doses of methylphenidate (25 mg/kg and 50 mg/kg) increased locomotion and sniffing behavior. Flurazepam 3.0 mg/kg augmented methylphenidate-induced stereotyped gnawing behavior and stereotypy. Flurazepam significantly decreased locomotion and sniffing, but did not interact with methylphenidate's effects on locomotion and sniffing.

Animals↗