The American Journal of Gastroenterology, Sep 1, 1999
The aim of this study was to compare subjective and objective measures of sleep quality in patien... more The aim of this study was to compare subjective and objective measures of sleep quality in patients with irritable bowel syndrome (IBS) and controls. The Pittsburgh Sleep Quality Index (PSQI) was used to measure subjective sleep quality, and polysomnography was performed during one night to obtain objective measures of sleep quality, including sleep efficiency, sleep latency, number of arousals, and percentage of slow-wave sleep. Participants were 15 IBS patients and 15 healthy controls. The results showed a significantly increased global PSQI score in patients, as well as significantly higher scores on several subcomponents of the PSQI (i.e., sleep quality, sleep latency, habitual sleep efficiency, and daytime dysfunction). Analysis of polysomnographic parameters revealed no significant group differences on any measure. Complaints of poor sleep quality in the absence of objective sleep abnormalities suggest altered sleep perception, and support that IBS involves exaggerated responses to normal internal or external stimuli.
Several studies have provided evidence of abnormal autonomic activity in irritable bowel syndrome... more Several studies have provided evidence of abnormal autonomic activity in irritable bowel syndrome (IBS), suggesting that abnormal central nervous system-autonomic nervous system arousal mechanisms may be part of its pathophysiology. The goal was to investigate cardiac sympatho-vagal balance during waking and the different stages of sleep using heart rate variability analysis in IBS patients compared to healthy controls. A total of 15 IBS patients (13 female, two male, mean age 34.9 +/- 2.1 yr) and 15 controls (13 female, two male, mean age 36.2 +/- 2.3 yr) were studied during 1 h of pre-sleep quiet waking and during seven-hours of sleep. Polysomnography was used for the determination of state of consciousness. Electrocardiography provided the beat-to-beat intervals, which were then subjected to spectral analysis for determination of the percentage of energy in the low and high frequency bands, respectively. The low frequency/high frequency band ratio was also calculated. For each su...
Recently, we have demonstrated that behavioral conditioning reduced splenocyte proliferation and ... more Recently, we have demonstrated that behavioral conditioning reduced splenocyte proliferation and IL-2 production in DA rats, and that these behaviorally conditioned immunosuppressive effects were completely abrogated by prior surgical denervation of the spleen. Since the splenic denervation significantly reduced catecholamine concentrations in the spleen, adrenergic mechanisms have been considered to play an important role in conditioned immunosuppression observed in this model. Thus, the current in vitro studies were designed to analyze the influence of adrenergic mechanisms on the proliferation of rat splenocytes, their IL-2 production, and IL-2 mRNA expression. The data demonstrate that beta-adrenoceptor agonist isoproterenol at concentrations of 10(-5) M diminished mitogen (ConA)-induced splenocyte proliferation by 75%, which was associated with a pronounced (50%) decrease in IL-2 production at both the protein and mRNA levels. The beta-adrenoceptor antagonist propranolol comple...
Proximal acid migration resulting from gastroesophageal reflux has been implicated in aerodigesti... more Proximal acid migration resulting from gastroesophageal reflux has been implicated in aerodigestive complaints and disorders. This study was designed to investigate the effects of acid volume, posture, and sleep on proximal esophageal acid migration (drop in pH to <4.0). The study was performed in 15 healthy adults. A distal esophageal acid perfusion technique to simulate gastroesophageal reflux was used. Esophageal acid perfusions of 1 ml and 3 ml were accomplished at a site 5 cm above the proximal border of the lower esophageal sphincter in the upright and supine positions during waking, and during polysomnographically monitored sleep. Esophageal pH was recorded by two sensors located in the mid- and proximal esophagus at 10 and 15 cm above the lower esophageal sphincter. Acid volume clearly increased the incidence of migration to the mid and proximal sensors during both waking and sleep, and also significantly increased acid clearance time. Posture failed to significantly affe...
The study goal was to investigate autonomic activity with heart rate variability analysis during ... more The study goal was to investigate autonomic activity with heart rate variability analysis during different sleep stages in males and females. The study utilized a 2 Groups (males, females) x 4 States (waking, stage 2 sleep, stage 4 sleep, rapid-eye movement sleep) mixed design with one repeated, within-subjects factor (i.e., state). The study was carried out in the sleep laboratory of the Thomas N. Lynn Institute for Healthcare Research. Twenty-four healthy adults (fourteen females and ten males). NA. All participants underwent polysomnographic monitoring and electrocardiogram recordings during pre-sleep waking and one night of sleep. Fifteen-minute segments of beat-to-beat heart rate intervals during waking, stage 2 sleep, stage 4 sleep, and REM sleep were subjected to spectral analysis. Compared to NREM sleep, REM sleep was associated with decreased high frequency (HF) band power, and significantly increased low frequency (LF) to (HF) ratio. Compared to females, males showed signi...
The aim of this study was to assess the effects of sleep on gastric myoelectric activity as measu... more The aim of this study was to assess the effects of sleep on gastric myoelectric activity as measured by electrogastrography in healthy individuals. The goal was to elucidate the role of central influences in the regulation of normal gastric functioning. Electrograstrogram (EGG) was recorded during polysomnographically monitored waking and sleep. Sleep laboratory. 17 healthy volunteers. EGG parameters were computed for 20-minute segments of pre-sleep waking, stage 2 sleep, stage 4 sleep, and REM sleep using both overall and running spectral analysis of EGG data. The dominant power decreased significantly from waking (31.4 +/- 1.4 dB) to all sleep stages (23.1 +/- 1.5 dB during stage 2; 24.7 +/- 1.4 dB during stage 4; 24.3 +/- 1.3 dB during REM sleep). The percentage of 2-4cpm activity decreased significantly during NREM sleep (64.6 +/- 7.6% during stage 2 sleep; 57.5 +/- 5.5% during stage 4 sleep) compared to its waking value (90.8 +/- 3.2%), but not compared to REM sleep (74.1 +/- 5...
The goal of this study was to investigate behavioral (self-reported) and physiological sleep char... more The goal of this study was to investigate behavioral (self-reported) and physiological sleep characteristics in irritable bowel syndrome (IBS) patients with and without concurrent dyspeptic symptoms, as compared to control subjects. A total of 31 women with IBS were stratified into two groups: 15 with bowel symptoms only (IBS-only) and 16 with both lower and upper dyspeptic symptoms (IBS+D). In addition, 23 healthy women served as controls. For 4 consecutive days, subjective sleep quality, insomnia symptoms, alertness, state anxiety, perceived daytime stress, and daytime and nighttime GI symptoms were assessed. On night 4, subjects underwent polysomnographic (PSG) monitoring for an objective assessment of sleep quality including microarousals and respiratory parameters. Saliva samples were collected for cortisol analyses each morning and evening across the 4 days of the study. Psychological disturbances were assessed with the SCL. Patients reported significantly more dissatisfaction...
Psychiatric problems are frequently experienced by persons with systemic lupus erythematosus (SLE... more Psychiatric problems are frequently experienced by persons with systemic lupus erythematosus (SLE). Some researchers and clinicians presume that these psychiatric problems are a direct manifestation of the disease, while others suggest that psychosocial and environmental factors have greater etiological significance. Our lack of knowledge regarding the etiology of psychiatric problems in this population is a serious limitation to selecting treatment approaches or to understanding treatment efficacy. Studies that employ group research designs to investigate the etiology or treatment of psychiatric problems in patients with SLE are inherently limited. Therefore, this article provides a general introduction to single-subject methodology and illustrates some potential applications to investigating psychiatric treatments in persons with SLE.
The American Journal of Gastroenterology, Sep 1, 1999
The aim of this study was to compare subjective and objective measures of sleep quality in patien... more The aim of this study was to compare subjective and objective measures of sleep quality in patients with irritable bowel syndrome (IBS) and controls. The Pittsburgh Sleep Quality Index (PSQI) was used to measure subjective sleep quality, and polysomnography was performed during one night to obtain objective measures of sleep quality, including sleep efficiency, sleep latency, number of arousals, and percentage of slow-wave sleep. Participants were 15 IBS patients and 15 healthy controls. The results showed a significantly increased global PSQI score in patients, as well as significantly higher scores on several subcomponents of the PSQI (i.e., sleep quality, sleep latency, habitual sleep efficiency, and daytime dysfunction). Analysis of polysomnographic parameters revealed no significant group differences on any measure. Complaints of poor sleep quality in the absence of objective sleep abnormalities suggest altered sleep perception, and support that IBS involves exaggerated responses to normal internal or external stimuli.
Several studies have provided evidence of abnormal autonomic activity in irritable bowel syndrome... more Several studies have provided evidence of abnormal autonomic activity in irritable bowel syndrome (IBS), suggesting that abnormal central nervous system-autonomic nervous system arousal mechanisms may be part of its pathophysiology. The goal was to investigate cardiac sympatho-vagal balance during waking and the different stages of sleep using heart rate variability analysis in IBS patients compared to healthy controls. A total of 15 IBS patients (13 female, two male, mean age 34.9 +/- 2.1 yr) and 15 controls (13 female, two male, mean age 36.2 +/- 2.3 yr) were studied during 1 h of pre-sleep quiet waking and during seven-hours of sleep. Polysomnography was used for the determination of state of consciousness. Electrocardiography provided the beat-to-beat intervals, which were then subjected to spectral analysis for determination of the percentage of energy in the low and high frequency bands, respectively. The low frequency/high frequency band ratio was also calculated. For each su...
Recently, we have demonstrated that behavioral conditioning reduced splenocyte proliferation and ... more Recently, we have demonstrated that behavioral conditioning reduced splenocyte proliferation and IL-2 production in DA rats, and that these behaviorally conditioned immunosuppressive effects were completely abrogated by prior surgical denervation of the spleen. Since the splenic denervation significantly reduced catecholamine concentrations in the spleen, adrenergic mechanisms have been considered to play an important role in conditioned immunosuppression observed in this model. Thus, the current in vitro studies were designed to analyze the influence of adrenergic mechanisms on the proliferation of rat splenocytes, their IL-2 production, and IL-2 mRNA expression. The data demonstrate that beta-adrenoceptor agonist isoproterenol at concentrations of 10(-5) M diminished mitogen (ConA)-induced splenocyte proliferation by 75%, which was associated with a pronounced (50%) decrease in IL-2 production at both the protein and mRNA levels. The beta-adrenoceptor antagonist propranolol comple...
Proximal acid migration resulting from gastroesophageal reflux has been implicated in aerodigesti... more Proximal acid migration resulting from gastroesophageal reflux has been implicated in aerodigestive complaints and disorders. This study was designed to investigate the effects of acid volume, posture, and sleep on proximal esophageal acid migration (drop in pH to <4.0). The study was performed in 15 healthy adults. A distal esophageal acid perfusion technique to simulate gastroesophageal reflux was used. Esophageal acid perfusions of 1 ml and 3 ml were accomplished at a site 5 cm above the proximal border of the lower esophageal sphincter in the upright and supine positions during waking, and during polysomnographically monitored sleep. Esophageal pH was recorded by two sensors located in the mid- and proximal esophagus at 10 and 15 cm above the lower esophageal sphincter. Acid volume clearly increased the incidence of migration to the mid and proximal sensors during both waking and sleep, and also significantly increased acid clearance time. Posture failed to significantly affe...
The study goal was to investigate autonomic activity with heart rate variability analysis during ... more The study goal was to investigate autonomic activity with heart rate variability analysis during different sleep stages in males and females. The study utilized a 2 Groups (males, females) x 4 States (waking, stage 2 sleep, stage 4 sleep, rapid-eye movement sleep) mixed design with one repeated, within-subjects factor (i.e., state). The study was carried out in the sleep laboratory of the Thomas N. Lynn Institute for Healthcare Research. Twenty-four healthy adults (fourteen females and ten males). NA. All participants underwent polysomnographic monitoring and electrocardiogram recordings during pre-sleep waking and one night of sleep. Fifteen-minute segments of beat-to-beat heart rate intervals during waking, stage 2 sleep, stage 4 sleep, and REM sleep were subjected to spectral analysis. Compared to NREM sleep, REM sleep was associated with decreased high frequency (HF) band power, and significantly increased low frequency (LF) to (HF) ratio. Compared to females, males showed signi...
The aim of this study was to assess the effects of sleep on gastric myoelectric activity as measu... more The aim of this study was to assess the effects of sleep on gastric myoelectric activity as measured by electrogastrography in healthy individuals. The goal was to elucidate the role of central influences in the regulation of normal gastric functioning. Electrograstrogram (EGG) was recorded during polysomnographically monitored waking and sleep. Sleep laboratory. 17 healthy volunteers. EGG parameters were computed for 20-minute segments of pre-sleep waking, stage 2 sleep, stage 4 sleep, and REM sleep using both overall and running spectral analysis of EGG data. The dominant power decreased significantly from waking (31.4 +/- 1.4 dB) to all sleep stages (23.1 +/- 1.5 dB during stage 2; 24.7 +/- 1.4 dB during stage 4; 24.3 +/- 1.3 dB during REM sleep). The percentage of 2-4cpm activity decreased significantly during NREM sleep (64.6 +/- 7.6% during stage 2 sleep; 57.5 +/- 5.5% during stage 4 sleep) compared to its waking value (90.8 +/- 3.2%), but not compared to REM sleep (74.1 +/- 5...
The goal of this study was to investigate behavioral (self-reported) and physiological sleep char... more The goal of this study was to investigate behavioral (self-reported) and physiological sleep characteristics in irritable bowel syndrome (IBS) patients with and without concurrent dyspeptic symptoms, as compared to control subjects. A total of 31 women with IBS were stratified into two groups: 15 with bowel symptoms only (IBS-only) and 16 with both lower and upper dyspeptic symptoms (IBS+D). In addition, 23 healthy women served as controls. For 4 consecutive days, subjective sleep quality, insomnia symptoms, alertness, state anxiety, perceived daytime stress, and daytime and nighttime GI symptoms were assessed. On night 4, subjects underwent polysomnographic (PSG) monitoring for an objective assessment of sleep quality including microarousals and respiratory parameters. Saliva samples were collected for cortisol analyses each morning and evening across the 4 days of the study. Psychological disturbances were assessed with the SCL. Patients reported significantly more dissatisfaction...
Psychiatric problems are frequently experienced by persons with systemic lupus erythematosus (SLE... more Psychiatric problems are frequently experienced by persons with systemic lupus erythematosus (SLE). Some researchers and clinicians presume that these psychiatric problems are a direct manifestation of the disease, while others suggest that psychosocial and environmental factors have greater etiological significance. Our lack of knowledge regarding the etiology of psychiatric problems in this population is a serious limitation to selecting treatment approaches or to understanding treatment efficacy. Studies that employ group research designs to investigate the etiology or treatment of psychiatric problems in patients with SLE are inherently limited. Therefore, this article provides a general introduction to single-subject methodology and illustrates some potential applications to investigating psychiatric treatments in persons with SLE.
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Papers by Michael Harnish