Search PubMed⌕ Search

Biomedical subjects

Greg Maislin

Publications and source records attributed to Greg Maislin.

At least 19 recordsLinked to original sources
PubMed2006

Novel method for high-throughput phenotyping of sleep in mice.

Assessment of sleep in mice currently requires initial implantation of chronic electrodes for assessment of electroencephalogram (EEG) and electromyogram (EMG) followed by time to recover from surgery. Hence, it is not ideal for high-throughput screening. To address this deficiency, a method of assessment of sleep and wakefulness in mice has been developed based on assessment of activity/inactivity either by digital video analysis or by breaking infrared beams in the mouse cage. It is based on the algorithm that any episode of continuous inactivity of > or =40 s is predicted to be sleep. The method gives excellent agreement in C57BL/6J male mice with simultaneous assessment of sleep by EEG/EMG recording. The average agreement over 8,640 10-s epochs in 24 h is 92% (n = 7 mice) with agreement in individual mice being 88-94%. Average EEG/EMG determined sleep per 2-h interval across the day was 59.4 min. The estimated mean difference (bias) per 2-h interval between inactivity-defined sleep and EEG/EMG-defined sleep was only 1.0 min (95% confidence interval for mean bias -0.06 to +2.6 min). The standard deviation of differences (precision) was 7.5 min per 2-h interval with 95% limits of agreement ranging from -13.7 to +15.7 min. Although bias significantly varied by time of day (P = 0.0007), the magnitude of time-of-day differences was not large (average bias during lights on and lights off was +5.0 and -3.0 min per 2-h interval, respectively). This method has applications in chemical mutagenesis and for studies of molecular changes in brain with sleep/wakefulness.

Algorithms↗
PubMed2006

Impaired performance in commercial drivers: role of sleep apnea and short sleep duration.

Sleepiness plays an important role in major crashes of commercial vehicles. Because determinants are likely to include inadequate sleep and sleep apnea, we evaluated the role of short sleep durations over 1 wk at home and sleep apnea in subjective sleepiness (Epworth Sleepiness Scale), objective sleepiness (reduced sleep latency as determined by the Multiple Sleep Latency Test), and neurobehavioral functioning (lapses in performance, tracking error in Divided Attention Driving Task) in commercial drivers. Studies were conducted in 247 of 551 drivers at higher risk for apnea and in 159 of 778 drivers at lower risk. A multivariate linear association between the sets of outcomes and risk factors was confirmed (p < 0.0001). Increases in subjective sleepiness were associated with shorter sleep durations but not with increases in severity of apnea. Increases in objective sleepiness and performance lapses, as well as poorer lane tracking, were associated with shorter sleep durations. Associations with sleep apnea severity were not as robust and not strictly monotonic. A significant linear association with sleep apnea was demonstrated only for reduced sleep latency. The effects of severe apnea (apnea-hypopnea index, at least 30 episodes/h), which occurred in 4.7%, and of sleep duration less than 5 h/night, which occurred in 13.5%, were similar in terms of their impact on objective sleepiness. Thus, addressing impairment in commercial drivers requires addressing both insufficient sleep and sleep apnea, the former being more common.

Automobile Driving↗
PubMed2006

Risk factors for excessive sleepiness in older adults.

OBJECTIVE: To determine risk factors for excessive daytime sleepiness in older adults. METHODS: This is a cross-sectional study assessing multiple risk factors for excessive daytime sleepiness in older subjects (mean age, 78 years; range 65-98 years) with (n=149) and without (n=144) complaints of frequent excessive daytime sleepiness. Assessment of risk factors included full in-laboratory sleep studies. RESULTS: Excessive sleepiness among the elderly is multifactorial. Multivariable modeling identified the following as simultaneously significant risk factors for excessive sleepiness: severe sleep-disordered breathing (apnea-hypopnea index, >30 episodes/hr), self-report of poor sleep quality, increased percentage of time in rapid eye movement sleep, pain at night at least three times per week, wheezing or whistling from chest at night, and medications with sleepiness as a side effect. Male sex also was associated with increased risk, whereas alcohol use (more than seven beverages per week) reduced the risk for sleepiness. Multiple risk factors were more commonly present in those with complaints of sleepiness. The presence of periodic limb movements, which are common in older adults, was not associated with sleepiness. INTERPRETATION: There is a distinct differential diagnosis of excessive daytime sleepiness in older adults. Many of the risk factors that we identified are treatable.

Aged↗
PubMed2006

Sleepiness and relationships in obstructive sleep apnea.

This is a qualitative analysis of data from a multisite study of 156 participants with Obstructive Sleep Apnea (OSA). Participants completed a battery of tests, including the Functional Outcomes of Sleep Questionnaire (FOSQ) that contains an item assessing the impact of OSA on relationships. Approximately one third of participants wrote comments; they were predominately male, mean age 44.7, with severe OSA. Interpersonal themes expressed included work and marital problems and social life restriction. Intrapersonal themes included embarrassment and poor mood. This report adds specific details to previous reports of impaired relationships in OSA, and stresses the importance of assessing this critical area.

Conflict, Psychological↗
PubMed2006

Assessment of sleep in women with night eating syndrome.

STUDY OBJECTIVES: Evaluation of sleep in subjects with night eating syndrome (NES). DESIGN: Polysomnographic and questionnaire comparisons between subjects with NES and controls. SETTING AND PARTICIPANTS: Fifteen women with NES (mean +/- SD = 41 +/- 8 years) and 14 women (comparable age and weight) without NES (39 +/- 10 years) were studied in the laboratory for 3 days. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Subjects with NES did not differ from controls in timing of sleep onset or offset. They had less stage 2 sleep than controls (minutes, p = .012; percentage, p = .016) and less stage 3 sleep (p = .023), which contributed to their having a lower total sleep time (p = .05) and reduced sleep efficiency (p = .03). Subjects with NES did not have more awakenings than controls, but 93.3% of them ate on awakening during all 3 nights, while 92.9% of controls did not eat on any night. Logistic discriminant analyses identified a multiple sleep parameter model associated with increased likelihood of NES that had sensitivity of 84.6% and specificity of 76.9%. Patients with NES were more depressed than controls (p < .001) and reported greater sleep disturbance that included lower sleep quality (p < or = .001), reduced sleep duration (p < or = .001), and increased number of awakenings (p < or = .001). CONCLUSIONS: Patients with NES appear to have sleep maintenance insomnia rather than sleep-related eating disorder or a parasomnia. The maintenance of normal timing for sleep-wake behavior in the presence of a phase delay in the timing of caloric intake suggests this disorder reflects a state of internal circadian desynchrony associated with significant sleep complaints. It remains unknown whether the sleep disturbance precedes the abnormally timed eating.

Adult↗
PubMed2005

Family aggregation of upper airway soft tissue structures in normal subjects and patients with sleep apnea.

RATIONALE: Sleep apnea is believed to be a genetic disorder. Thus, we hypothesized that anatomic risk factors for sleep apnea would demonstrate family aggregation. OBJECTIVES: We used volumetric magnetic resonance imaging in a sib pair "quad" design to study the family aggregation of the size of upper airway soft tissue structures that are associated with increased risk for obstructive sleep apnea. METHODS: We examined 55 sleep apnea probands (apnea-hypopnea index [AHI]: 43.2 +/- 26.3 events/h), 55 proband siblings (AHI: 11.8 +/- 16.6 events/h), 55 control subjects (AHI: 2.1 +/- 1.7 events/h), and 55 control siblings (AHI: 4.2 +/- 4.0 events/h). The study design used exact matching on ethnicity and sex, frequency matching on age, and statistical control for visceral neck fat and craniofacial dimensions. MEASUREMENTS AND MAIN RESULTS: The data support our a priori hypothesis that the volume of the important upper airway soft tissue structures is heritable. The volume of the lateral pharyngeal walls (h(2) = 36.8%; p = 0.001), tongue (h(2) = 36.5%; p = 0.0001), and total soft tissue (h(2) = 37.5%; p = 0.0001) demonstrated significant levels of heritability after adjusting for sex, ethnicity, age, visceral neck fat, and craniofacial dimensions. In addition, our data indicate that heritability of the upper airway soft tissue structures is found in normal subjects and patients with apnea. Thus, it is not simply a consequence of the prevalence of apnea. CONCLUSIONS: This is the first time family aggregation of size of the upper airway soft tissue structures has been demonstrated.

Adult↗
PubMed2005

Growth of children at high risk of obesity during the first 6 y of life: implications for prevention.

BACKGROUND: The contribution of familial factors to adiposity in children is poorly understood. OBJECTIVE: The objective was to assess differences in growth in the first 6 y of life in children born to either overweight or lean mothers. DESIGN: The body size and composition of 33 children at high risk and 37 children at low risk of obesity on the basis of the mother's overweight [body mass index (BMI; in kg/m(2)) of 30.2 +/- 4.2 and 19.5 +/- 1.1, respectively] were measured repeatedly from 3 mo to 6 y of age at the Children's Hospital of Philadelphia. RESULTS: At year 2, no significant differences in any measure were observed between the high- and low-risk groups. By year 4, weight, BMI, and lean body mass were greater in the high-risk than in the low-risk children. By year 6, weight was even greater in the high-risk than in the low-risk children (23.4 +/- 6.4 compared with 20.4 +/- 2.1 kg; P < 0.02), and, for the first time, fat mass was greater in the high-risk than in the low-risk children (6.7 +/- 5.7 compared with 3.8 +/- 1.2 kg; P < 0.02). Ten of 33 high-risk children exceeded the 85th percentile of BMI at year 6 compared with 1 of 37 low-risk children (odds ratio = 15.7). Accelerated weight gain was predicted by high-risk group status, greater weight at year 2, and lower family income. CONCLUSION: Anthropometric measures were not significantly different between groups at year 2; weight and lean body mass were greater at years 4 and 6, and fat mass was greater at year 6 in high-risk children.

Body Mass Index↗
PubMed2005

Claustrophobia and adherence to CPAP treatment.

This study evaluated the effect of claustrophobia, an abnormal dread or fear of closed spaces, on adherence to continuous positive airway pressure (CPAP) therapy. The design was a secondary analysis of data from a prospective study of participants (N = 153) that completed 3 months of CPAP therapy from seven sleep disorders centers in the United States and Canada. A 15-item subscale adapted from the Fear and Avoidance Scale measured claustrophobic tendencies pre-CPAP treatment and again after 3 months. An overt monitor attached to the CPAP machines recorded mask-on CPAP adherence. There was a statistically significant difference in claustrophobia scores by adherence group (< 2 hours, 2 to < 5 hours, > or = 5 hours) and time period (pre-CPAP and after 3 months CPAP). Poor CPAP adherence (< 2 hours per night)was more than two times higher in participants with a claustrophobia score > or = 25. Identification of persons with increased claustrophobia tendencies and targeted interventions may increase adherence.

Adult↗
PubMed2005

Functional status measures for integrating medical and social care.

PURPOSE: Identify standard self-report questions about functioning suitable for measuring disability across integrated health and social services. THEORY: Functional activities can be validly grouped according to the International Classification of Functioning, Disability and Health (ICF) chapters of mobility, self-care, and domestic life. METHODS: Cross-sectional analysis using information on 112,601 persons interviewed as part of the United States National Health Interview Survey on Disability. We combined related sets of questions and tested the appropriateness of their groupings through confirmatory factor analyses. Construct validity was addressed by seeking to confirm clinically logical relationships between the resulting functional scales and related health concepts, including number of physician contacts, number of bed days, perception of illness, and perception of disability. RESULTS: Internal consistency for the summed scales ranged from 0.78 to 0.92. Correlations between the functional scales and related concepts ranged from 0.12 to 0.52 in directions consistent with expectations. CONCLUSIONS: Analyses supported the 3 ICF chapters. DISCUSSIONS: The routine collection of this core set of functions could enhance decision-making at the client, professional, organizational, and policy levels encouraging cooperation among the medical and social service sectors when caring for people with disabilities.

Journal Article↗
PubMed2004

Outcomes in children with idiopathic pulmonary arterial hypertension.

BACKGROUND: Treatment for idiopathic pulmonary arterial hypertension in children includes calcium channel blockade (CCB) for acute responders with vasodilator testing and chronic epoprostenol for nonresponders. We sought to determine parameters associated with survival and treatment success. METHODS AND RESULTS: A previously identified cohort of 77 children diagnosed between 1982 and 1995 with idiopathic pulmonary arterial hypertension was followed up through 2002. For acute responders treated with CCB (n=31), survival at 1, 5, and 10 years was 97%, 97%, and 81%, respectively; treatment success was 84%, 68%, and 47%, respectively. Survival for all children treated with epoprostenol (n=35) at 1, 5, and 10 years was 94%, 81%, and 61%, respectively; treatment success was 83%, 57%, and 37%, respectively. Because of the inconsistent availability of epoprostenol before 1995, we defined a "recent medical era" subset by excluding children from the total 77 patient cohort for whom epoprostenol was recommended but was unavailable. Survival in the recent medical era (n=44) at 1, 5, and 10 years was 97%, 97%, and 78%; treatment success was 93%, 86%, and 60%, respectively. Treatment success on CCB decreased significantly when acute responders became nonresponders. Age at diagnosis predicted treatment success in the recent medical era. CONCLUSIONS: Survival for children with idiopathic pulmonary arterial hypertension has significantly improved with CCB and epoprostenol. Children who are acute responders are treated with CCB; they are treated with epoprostenol if they become nonresponders. The decrease in survival and in treatment success after 5 years in all children supports the role for transplant evaluation before treatment failure.

Adolescent↗
PubMed2004

Mandibular dimensions in children with obstructive sleep apnea syndrome.

OBJECTIVE: We hypothesized that mandibular size may play a role in the etiology of obstructive sleep apnea syndrome (OSAS) in children, since a smaller mandible may reduce airway size. We used magnetic resonance imaging to determine the mandible dimensions of children with OSAS. DESIGN: Case control study. SETTING: Tertiary-care pediatric hospital. PARTICIPANTS: Twenty-four subjects (mean age 4.9 +/- 1.7 years) with mild to moderate OSAS (Apnea Index 3.5 +/- 5.1), and 24 matched controls (mean age 4.9 +/- 1.8 years). INTERVENTION: Magnetic resonance imaging of the upper airway under sedation. MEASUREMENTS: Eight measurements were obtained from a 3-dimensional segmentation of the mandible using 3DVIEWNIX software. Measurements included length, height, width, midsymphysis menti angle, angle of mandible, enclosure area, surface area, and volume. Descriptive comparisons using Student t test and multivariate analyses of variance were performed. RESULTS: Individual measurement comparisons revealed no significant differences between groups. Multivariate analysis showed a lower bound of a 95% confidence interval for an effect size measure for "general mandibular size," including all 6 linear, the area, and the volume measurements, to be -0.25. CONCLUSION: Our study shows that a smaller mandible is not a feature in children with OSAS who do not have apparent craniofacial abnormalities.

Case-Control Studies↗
PubMed2004

Occupational screening for obstructive sleep apnea in commercial drivers.

Excluding the presence of obstructive sleep apnea in commercial drivers is valuable, as the syndrome may increase their risk of sleepiness-related accidents. Using polysomnography as the criterion standard, we prospectively compared accuracies of five strategies in excluding the presence of severe sleep apnea and, secondarily, any sleep apnea among 406 commercial drivers. These strategies were as follows: (1) symptoms; (2) body mass index; (3) symptoms plus body mass index; (4) a two-stage approach with symptoms plus body mass index for everyone, followed by oximetry for a subset; and (5) oximetry for all. For excluding severe apnea, the two-stage strategy was highly successful, with 91% sensitivity and specificity, and a negative likelihood ratio of 0.10. This strategy was comparable in accuracy to oximetry, which had a negative likelihood ratio of 0.12, and was 88% sensitive and 95% specific. If we avoided oximetry altogether, then symptoms together with body mass index were 81% sensitive and 73% specific, with a negative likelihood ratio of 0.26. On the other hand, excluding any apnea could not be done with reasonable accuracy unless oximetry was used. We conclude that two-stage screening is likely to be a viable means of excluding severe sleep apnea among commercial drivers.

Adult↗
PubMed2004

Systematic interindividual differences in neurobehavioral impairment from sleep loss: evidence of trait-like differential vulnerability.

OBJECTIVES: To investigate interindividual differences in neurobehavioral deficits during sleep deprivation, and to establish to what extent the neurobehavioral responses to sleep loss are a function of sleep history versus trait-like differential vulnerability. DESIGN: Individuals were exposed to sleep deprivation on 3 separate occasions in order to determine the stability of interindividual differences in neurobehavioral impairment. SETTING: The sleep-deprivation experiments were conducted under standardized laboratory conditions with continuous monitoring of wakefulness. Each subject underwent a laboratory-adaptation session before entering the sleep-deprivation phase of the study. PARTICIPANTS: A total of 21 healthy adults (aged 21-38 years) completed the experiment. INTERVENTIONS: Subjects came to the laboratory 3 times at intervals of at least 2 weeks. During each laboratory session, they underwent neurobehavioral testing every 2 hours during 36 hours of total sleep deprivation, which was preceded by baseline sleep and followed by recovery sleep. In the week prior to each sleep-deprivation session and on the baseline night in the laboratory, subjects were required to either restrict their sleep to 6 hours per day (prior sleep restriction condition) or to extend their time in bed to 12 hours per day (prior sleep extension condition), so as to experimentally manipulate sleep history (in randomized counterbalanced order). RESULTS: There was strong evidence that interindividual differences in neurobehavioral deficits during sleep deprivation were systematic and trait-like. The magnitude of interindividual variability was substantial relative to the magnitude of the effect of prior sleep restriction (which on average involved a reduction of 4.1 hours sleep per day, compared to prior sleep extension, for 7 days). Overall, interindividual differences were not explained by subjects' baseline functioning or a variety of other potential predictors. Interindividual variability clustered on 3 distinct neurobehavioral dimensions: self-evaluation of sleepiness, fatigue, and mood; cognitive processing capability; and behavioral alertness as measured by sustained attention performance. CONCLUSIONS: Neurobehavioral deficits from sleep loss varied significantly among individuals and were stable within individuals. Interindividual differences in neurobehavioral responses to sleep deprivation were not merely a consequence of variations in sleep history. Rather, they involved trait-like differential vulnerability to impairment from sleep loss, for which neurobiologic correlates have yet to be discovered.

Adaptation, Psychological↗
PubMed2004

Estimating health-related quality of life in populations through cross-sectional surveys.

BACKGROUND: Health-related quality of life (HRQL) is optimally reported from the individual vantage point; consequently, prevalence estimates from the National Health Interview Survey (NHIS) could be misleading, because approximately one third of the information is proxy-provided. OBJECTIVE: The objective of this study was to discern the degree to which disparities in the crude prevalence of reduced HRQL is explainable by case-mix differences between proxy- and self-reportees. SUBJECTS: We studied the cross-sectional data on 96,091 persons from the 1994-1995 NHIS Supplement on Disability. RESEARCH DESIGN: We conducted a study of reduced HRQL expressed as a respondent type indicator (proxy vs. self) adjusting for socioeconomic differences and limitations in function. MEASURES: We studied reduced HRQL indicated by 1) perception of poor health, 2) perception of disability, 3) 30 or more bed days in the last year, or 4) 20 or more doctor visits in the last year. RESULTS: The crude estimated prevalence of reduced HRQL for proxy reports was approximately half that of self-reports. Although the unadjusted odds ratios (ORs) for proxy- compared with self-reportees ranged from 0.51 (95% confidence interval [CI], 0.47-0.55) to 0.59 (95% CI, 0.55-0.64), case-mix adjustment resulted in a significant directional change for poor health perception, and all adjusted ORs were substantially closer to 1.0 than their unadjusted counterparts. CONCLUSION: Adjustment for case-mix explained away most of the proxy-/self-report disparity, suggesting that a major component of differences in prevalence between proxy- and self-respondents is case-mix-related. Consequently, compared with excluding proxy reports, inclusion of proxy reports results in relatively less bias when the NHIS-D is applied to obtain prevalence estimates for the indicators studied.

Activities of Daily Living↗
PubMed2004

Transitional care of older adults hospitalized with heart failure: a randomized, controlled trial.

OBJECTIVES: To examine the effectiveness of a transitional care intervention delivered by advanced practice nurses (APNs) to elders hospitalized with heart failure. DESIGN: Randomized, controlled trial with follow-up through 52 weeks postindex hospital discharge. SETTING: Six Philadelphia academic and community hospitals. PARTICIPANTS: Two hundred thirty-nine eligible patients were aged 65 and older and hospitalized with heart failure. INTERVENTION: A 3-month APN-directed discharge planning and home follow-up protocol. MEASUREMENTS: Time to first rehospitalization or death, number of rehospitalizations, quality of life, functional status, costs, and satisfaction with care. RESULTS: Mean age of patients (control n=121; intervention n=118) enrolled was 76; 43% were male, and 36% were African American. Time to first readmission or death was longer in intervention patients (log rank chi(2)=5.0, P=.026; Cox regression incidence density ratio=1.65, 95% confidence interval=1.13-2.40). At 52 weeks, intervention group patients had fewer readmissions (104 vs 162, P=.047) and lower mean total costs ($7,636 vs $12,481, P=.002). For intervention patients, only short-term improvements were demonstrated in overall quality of life (12 weeks, P<.05), physical dimension of quality of life (2 weeks, P<.01; 12 weeks, P<.05) and patient satisfaction (assessed at 2 and 6 weeks, P<.001). CONCLUSION: A comprehensive transitional care intervention for elders hospitalized with heart failure increased the length of time between hospital discharge and readmission or death, reduced total number of rehospitalizations, and decreased healthcare costs, thus demonstrating great promise for improving clinical and economic outcomes.

Black or African American↗
PubMed2004

Dealing with inter-individual differences in the temporal dynamics of fatigue and performance: importance and techniques.

Inter-individual differences in performance impairment from sleep loss are substantial and consistent, as demonstrated and quantified here by means of the intraclass correlation coefficient (ICC) in two laboratory-based sleep deprivation studies. There is an urgent need, therefore, to consider inter-individual variability in biomathematical models of fatigue and performance, which currently treat individuals as being all the same. Traditional regression techniques do not handle inter-individual variability, but cutting-edge mixed-effects modeling techniques have recently become available to deal with inter-individual differences in the temporal dynamics of fatigue and performance. The standard two stage (STS), restricted maximum likelihood (REML), and non-linear mixed-effects modeling (NMEM) approaches to mixed-effects models are compared here using data from a chronic partial sleep deprivation experiment. Mixed-effects modeling can be incorporated in the two distinct steps (the direct and inverse problems) of biomathematical model development in order to deal with inter-individual differences. This paper demonstrates that inter-individual variability accounts for a large percentage of observed variance in neurobehavioral responses to sleep deprivation, and describes tools that model developers will need to produce a new generation of fatigue and performance models capable of incorporating inter-individual variability and useful for subject-specific prediction.

Fatigue↗
PubMed2003

Human diaphragm remodeling associated with chronic obstructive pulmonary disease: clinical implications.

Diaphragm remodeling associated with chronic obstructive pulmonary disease (COPD) consists of a fast-to-slow fiber type transformation as well as adaptations within each fiber type. To try to explain disparate findings in the literature regarding the relationship between fiber type proportions and FEV1, we obtained costal diaphragm biopsies on 40 subjects whose FEV1 ranged from 118 to 16% of the predicted normal value. First, we noted that our exponential regression model indicated that changes in FEV1 can account for 72% of the variation in the proportion of Type I fibers. Second, to assess the impact of COPD on diaphragm force generation, we measured maximal specific force generated by single permeabilized fibers prepared from the diaphragms of two patients with normal pulmonary function tests and two patients with severe COPD. We noted that fibers prepared from the diaphragms of severe COPD patients generated a lower specific force than control fibers (p < 0.001) and Type I fibers generated a lower specific force than Type II fibers (p < 0.001). Our finding of an exponential relationship between the proportion of Type I fibers and FEV1 accounts for discrepancies in the literature. Moreover, our single-fiber results suggest that COPD-associated diaphragm remodeling decreases diaphragmatic force generation by adaptations within each fiber type as well as by fiber type transformations.

Adaptation, Physiological↗