Epidemiologic findings on the relationship of time of day and time since last meal to glucose tolerance

Data from 10,559 men and women, age 30-64, participating in the morning and afternoon in a Chicago Health Department multiphasic screening project, were used to determine the effects of time of day and time since last meal on the values for plasma glucose one and two hours following oral challenge with 100 gm. of glucose. Mean plasma glucose values and rates of suspect glucose intolerance (based on several cutpoints) were sizeably higher in the afternoon than in the morning. In addition, plasma glucose values increased with time elapsed since the last meal, up to 10 hours postprandially. Thereafter, both one- and two-hour plasma glucose values tended to exhibit a decline. Analysis of covariance confirmed that fluctuations in glucose tolerance were related to time of day and time since last meal, but the effects of each parameter were exerted independently.     

Dynamics of EEG spindle frequency activity during extended sleep in humans: relationship to slow-wave activity and time of day

The dynamics of EEG spindle frequency activity (SFA; spectral power density in the 12.25-15.0 Hz range) and its relationship to slow-wave activity (SWA; 0.75-4.5 Hz) were investigated in long sleep episodes (> 12 h). Young healthy men went to bed at either 19:00 h (early sleep; prior waking 36 h, n = 9) or 24:00 h (late sleep; prior waking 17 h, n = 8). In both nights, SWA in non-rapid-eye-movement sleep (NREMS) decreased over the first three to four 1.5-h intervals and remained at a low level in the subsequent five to six 1.5-h intervals. In contrast, the changes of SFA were more variable and differed between the lower (12.25-13.0 Hz), middle (13.25-14.0 Hz) and higher frequency bin (14.25-15.0 Hz). A pronounced influence of time of day was present in the lower and higher SFA bin, when the dynamics were analyzed with respect to clock time. In both the early and late sleep condition, power density in the lower bin was highest between 2:00 and 5:00 h in the morning and decreased thereafter. In the higher bin, power density was low in the early morning hours and increased as sleep was extended into the daytime hours. The results provide further evidence for a frequency-specific circadian modulation of SFA which becomes more evident at a time when SWA is low.     

Effects of sleep inertia after daytime naps vary with executive load and time of day.

The effects of executive load on working memory performance during sleep inertia after morning or afternoon naps were assessed using a mixed design with nap/wake as a between-subjects factor and morning/afternoon condition as a within-subject factor. Thirty-two healthy adults (mean 22.5 ± 3.0 years) attended two laboratory sessions after a night of restricted sleep (6 hrs), and at first visit, were randomly assigned to the Nap or Wake group. Working memory (n-back) and subjective workload were assessed approximately 5 and 25 minutes after 90-minute morning and afternoon nap opportunities and at the corresponding times in the Wake condition. Actigraphically assessed nocturnal sleep duration, subjective sleepiness, and psychomotor vigilance performance before daytime assessments did not vary across conditions. Afternoon naps showed shorter EEG assessed sleep latencies, longer sleep duration, and more Slow Wave Sleep than morning naps. Working memory performance deteriorated, and subjective mental workload increased at higher executive loadings. After afternoon naps, participants performed less well on more executive-function intensive working memory tasks (i.e., 3-back), but waking and napping participants performed equally well on simpler tasks. After some 30 minutes of cognitive activity, there were no longer performance differences between the waking and napping groups. Subjective Task Difficulty and Mental Effort requirements were less affected by sleep inertia and dissociated from objective measures when participants had napped in the afternoon. We conclude that executive functions take longer to return to asymptotic performance after sleep than does performance of simpler tasks which are less reliant on executive functions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Companionable sleep: Social regulation of sleep and cosleeping in egyptian families.

This exploratory study examined family sleep patterns and quality in a setting of normative napping and cosleeping. Participants were 78 members of 16 families from 2 locales in Egypt (Cairo and a village). Each family member provided a history of sleeping arrangements, 1 week of continuous activity records, and details of each sleep event. Sleep records documented late-onset and dispersed sleep patterns with extensive cosleeping. Of recorded sleep events, 69% involved cosleeping, 24% included more than 1 cosleeper, and only 21% were solitary. Mid-late afternoon napping occurred on 31% of days, and night sleep onsets averaged after midnight. Age and gender structured sleep arrangements and, together with locale, extensively explained sleep behavior (onset, duration, total) and quality. Cosleepers had fewer night arousals, shorter and less variable night sleep duration, and less total sleep. Increased solitary sleep in adolescents and young adults was associated with increased sleep dysregulation, including exaggerated phase shifts in males and more nighttime arousals in females. Where normative, cosleeping may provide psychosensory stimuli that moderate arousal and stabilize sleep. Such moderating features may address important self-regulatory developmental needs during adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Origin and evolution of sleep: roles of vision and endothermy

The origin of both sleep and memory appears to be closely associated with the evolution of mechanisms of enhancement and maintenance of synaptic efficacy. After the origin of activity-dependent synaptic plasticity, whereby single activations of synapses led to short-term efficacy enhancements, lengthy maintenance of the enhancements probably was achieved by repetitive activations ("dynamic stabilization"). These are thought to have occurred either in the course of frequent functional use, or to have been induced spontaneously within the brain to maintain synaptic efficacies in circuits that were in infrequent use. The latter repetitive activations are referred to as 'non-utilitarian' dynamic stabilization. With the evolution of increasing repertories and complexities of behavioral and sensory capabilities-with vision usually being the vastly preeminent sense-brain complexity increased markedly. Accompanying the greater complexity, needs for storage and maintenance of hereditary and experimental information (memories) also increased greatly. It is suggested that these increases led to conflicts between sensory input processing during restful waking and concomitant 'non-utilitarian' dynamic stabilization of infrequently used memory circuits. The selective pressure for the origin of primitive sleep may have been a need to achieve greater depression of central processing of sensory inputs-largely complex visual information-than occurs during restful waking. The electrical activities of the brain during sleep (aside from those that subserve autonomic activities) may function largely to maintain sleep and to dynamically stabilize infrequently used circuitry encoding memories. Sleep may not have been the only evolutionary adaptation to conflicts between dynamic stabilization and sensory input processing. In some ectothermic vertebrates, sleep may have been postponed or rendered unnecessary by a more readily effected means of resolution of the conflicts, namely, extensive retinal processing of visual information during restful waking. By this means, processing of visual information in central regions of the brain may have been maintained at a sufficiently low level to allow adequate concomitant dynamic stabilization. As endothermy evolved, the skeletal muscle hypotonia of primitive sleep may have become insufficient to prevent sleep-disrupting skeletal muscle contractions during 'non-utilitarian' dynamic stabilization of motor circuitry at the accompanying higher body temperatures and metabolic rates. Selection against such disruption during dynamic stabilization of motor circuitry may have led to the inhibition of skeletal muscle tone during a portion of primitive sleep, the portion designated as "rapid-eye-movement sleep." Many marine mammals that are active almost continuously engage only in unihemispheric non-rapid-eye-movement sleep. They apparently do not require rapid-eye-movement sleep and accompanying 'non-utilitarian' dynamic stabilization of motor circuitry because this circuitry is in virtually continuous use. Studies of hibernation by arctic ground squirrels suggest that each hour of sleep stabilizes brain synapses for as long as four hours.     

The role of neuropeptides in normal and disordered sleep regulation

The neuropeptides growth hormone-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) play a key role in sleep endocrine regulation. After pulsatile application of GHRH during the first few hours of the night in young normal controls SWS and GH increase, whereas cortisol is blunted. CRH however prompts inverse effects. The balance between these peptides is changed in favour of CRH physiologically during the second time of the night, during the acute episode of depression (due to overactivity of GRH) and in the elderly (due to reduced activity of CHRH). These changes explain the aberrances of sleep endocrine activity in these states, as shallow sleep, low GH and enhanced cortisol.     

The cricothyroid space: topography and clinical implications

The inferior border of the thyroid cartilage and the superior rim of the cricoid arch are connected by the cricothyroid membrane and partly covered by the cricothyroid muscles ventrally. This region has been termed the cricothyroid space (CS) and is important with regard to surgical procedures, the spread of laryngeal cancer and traumatic lesions of the larynx. The precise topographic relations of the CS were investigated in plastinated serial sections of 21 normal adult human specimens. The CS consists of a caudal and a cranial portion, which are different with regard to their cartilaginous framework and their relationship to intralaryngeal structures. The caudal portion is bordered by the cricoid cartilage and reveals a complete separation of extra- and intralaryngeal regions by the cricothyroid membrane. It provides an easy access to the subglottic airways. The cranial portion of the CS is mainly bordered by the thyroid cartilage. It is characterized by a gap lateral to the median cricothyroid ligament. This allows a connection of extra- and intralaryngeal adipose tissue. There, extralaryngeal extension of laryngeal cancer preferentially occurs. Traumatic subglottic ruptures of the larynx involve both the caudal and cranial portions of the CS, which often results in extensive scar tissue formation.     

Effects of the endogenous clock and sleep time on melatonin, insulin, glucose and lipid metabolism

Annexins are a unique family of membrane-associated, Ca2+ and phospholipid-binding proteins found in various tissues. Among the 12 isoforms, Annexin II, V and VI exist in heart tissue in the highest amounts. Annexin VI has been shown to affect intracellular Ca2+ cycling and contractility in isolated cardiomyocytes. Annexin V is present in both cardiomyocytes and non-myocyte cell types in the heart and may play a role in the regulation of cellular ion fluxes, organization and secretion, while the cardiac effects of annexin II are unclear. To identify changes in annexin II, V and VI isoforms that might occur in human heart failure, we measured mRNA and protein levels of these three annexins in transplanted left ventricular tissue of 12 patients with end-stage congestive heart failure due to coronary artery disease (CAD, n=6) or idiopathic dilated cardiomyopathy (DCM, n=6) who underwent cardiac transplantation. Normal heart tissue (C, n=6) was used as a control. Northern blot analyses showed a significant decrease (61%) in annexin VI mRNA levels in heart failure patients compared with controls (1.08+/-0.16 v 2.79+/-0.20 A.U.C. unit, determined by laser densitometry, mean+/-s.e.). In contrast, we found a 67% increase (2. 32+/-0.27 v 3.88+/-0.29) in annexin II mRNA levels and a two-fold increase (1.00+/-0.24 v 2.21+/-0.29) in annexin V mRNA levels in cardiomyopathic hearts as compared to normal hearts. Western blot analyses demonstrated a corresponding decrease (46.1%) in annexin VI protein levels in the heart failure group as compared to controls (2. 63+/-0.22 v 4.88+/-0.52), while annexin II protein levels showed a significant 40.7% increase in patients with heart failure compared to those in normal hearts (5.08+/-0.67 v 3.61+/-0.32). Annexin V protein levels were also significantly increased (45%) in heart failure patients compared with normal (2.14+/-0.19 v 1.48+/-0.11). No difference in either annexins II, V or VI mRNA and protein levels were found between CAD and DCM patients. We conclude that human end-stage heart failure is associated with a down regulation of annexin VI and up regulation of annexin II and V proteins. Coordinate changes were observed in steady-state mRNA levels. These results suggest that these annexin isoforms may contribute to the regulation of intracellular Ca2+ homeostasis in the cardiomyopathic heart.     

Apomorphine-induced yawning in the rat: influence of fasting and time of day

Yawning behavior is an experimental tool to study physiological responses, to elucidate the mechanisms of action of some drugs and hormones, and it is also a paradigm for some diseases and for dopamine (DA) agonists' clinical use. In this study, the effects of 24- and 48-h fasting as well as the influence of the light-dark cycle on apomorphine (APO)-induced yawning were evaluated. Initially, control and 48-h-fasted adult male rats were tested for yawning induced by APO (50, 100, 150 micrograms/kg, SC). The most effective dose tested was 100 micrograms/kg. Fasting significantly lowered yawning in all doses tested. Comparison between 24- and 48-h-fasted rats for APO (100 micrograms/kg)-induced yawning showed no significant difference between groups. Ad lib-fed groups were tested for APO (100 micrograms/kg)-induced yawning in both the light and in the dark phases of the cycle. Total number of yawnings increased significantly in the dark period. The present data show that fasting reduces and dark period increases APO-induced yawning in rats, suggesting that these conditions modulate the expression of this behavior.     

Drug abuse day treatment: a randomized clinical trial comparing day and residential treatment programs

Clients entering a therapeutic community (TC)-oriented drug treatment program were randomly assigned to day or residential conditions and interviewed at 2 weeks and 6 months after admission. Outcomes included Addiction Severity Index composite scores and summary scores for the Beck Depression Inventory, Symptom Checklist-90-R, and a social support scale. Only clients who remained in treatment for at least 2 weeks were included. The mean age of the sample (N = 261) was 32.9 (SD = 6.7 years) and the mean education level was 12.1 years (SD = 1.9 years); 30% were women. Comparison of outcome scores at 6 months between groups, while controlling for baseline values, indicated greater improvement for residential clients on social problems and psychiatric symptoms. The groups were similar on the 8 remaining outcomes, including measures of alcohol and drug problems. Overall, the level of improvement among day treatment clients was not significantly different from that of residential clients.     

The angiosomes of the forearm: anatomic study and clinical implications

The angiosome concept was introduced in 1987 by Taylor and Palmer. Their anatomic study correlated the blood supply to the skin from the named segmental or distributing "source" arteries with their supply to the underlying muscles, tendons, nerves, and bones. Although this investigation encompassed the body, there were areas where the supply to individual tissues was not examined in detail. The present study, therefore, examines one of these regions where certain voids in our knowledge still exist--the forearm. Ten upper limbs from fresh cadavers were studied over an 18-month period after perfusing each with a radiopaque lead oxide mixture. The arterial supply to the skin and the bones of the forearm, together with that of a total of 200 muscles, was examined. The contribution to each was defined by dissection, by metal clip tagging of vessels, by radiography, and by mapping the branches with colored pins coded to match the respective source arteries. In the case of the muscles, a subtraction technique was used whereby the bones of the extremity were replaced with radiolucent balloons to obtain an unobscured picture of the forearm vasculature. Then the muscles were removed one by one from the muscle mass and x-rayed again. In this way, the angiosomes in the forearm, provided by the brachial, radial, ulnar, and interosseous arteries, were defined. Similarly, the contribution from each angiosome to the skin, to each muscle, and to the radius and the ulna was identified and the territories were color-coded to match these source arteries. Results showed that in most cases the connections between adjacent angiosomes occurred within tissues, not between them. The skin, the bones, and most muscles received branches from the source arteries of at least two angiosomes, thus revealing one of the important anastomotic pathways by which the circulation is reconstituted in those cases where a source artery is interrupted by disease or trauma. Several muscles, however, were supplied within one angiosome. This helps explain the variable clinical pictures seen in cases where the circulation is interrupted, such as that which occurs in a Volkmann's ischemic contracture. Finally, this anatomic study provides further information to help design various flaps from the forearm for local or free transfer. In the case of muscles, the supply to most from multiple angiosomes allows for refinements whereby a portion only of a muscle can be used. Similarly, this anatomic information reveals the pathway by which the supply to remaining muscle groups is reconstituted when one of the source arteries is harvested with a skin flap, a muscle, or part thereof.     

Estimation of the time course of slow-wave sleep over the night in depressed patients: effects of clomipramine and clinical response

The distribution of slow-wave activity during sleep has been analyzed using a method related to the two-process model of sleep regulation. This method is applied to the analyses of data collected from 21 inpatients with unipolar depression who received the antidepressant clomipramine (CMI) in a pulse-loading protocol. CMI infusion was found to redistribute slow-wave activity, producing more concentration in the early part of the night, and also significantly reduced the fluctuation in slow-wave power as a function of time. These measures also distinguished clinical responders from the nonresponders. Drug responders had a significant redistribution of slow-wave activity to the earlier part of the night as compared to nonresponders. This suggests that measures of the distribution of slow-wave activity over the night may represent a good measure of clinical response to antidepressant therapy and have implications for the interpretation of the two-process model and sleep in depression.     

The role of dietary calcium in hypertensive disease: update and clinical implications

The pancreatic beta-cell response to stimulation with glucose and GIP, single and combined, was studied in acromegalics and in normal subjects. Acromegalics had higher IRI and GIP basal values with glucose levels and glucose disposal in the normal range. Further, acromegalics showed a greater IRI response to glucose, GIP and glucose combined with GIP. The results suggested that high growth hormone levels cause a greater activity of the entero-insular axis both in the basal state and after meal ingestion, as mimicked by GIP infusion. From these and previous observations, it can be assumed that growth hormone induces a facilitation of the IRI response to metabolite substrates and hormones.     

The clinical implications of autoantibody detection in rheumatology

The laboratory plays an increasing role in the diagnosis and clinical management of patients with rheumatic diseases. It is therefore essential that the results of laboratory tests are both accurate and reliable, and give clinicians correct information. It is also important to keep clinicians informed of the changes occurring in the rapidly evolving field of investigation of autoantibodies.     

The clinical exchange: The girl who cried every day for 3 years.

The Clinical Exchange invites eminent clinicians of diverse persuasions to share, in ordinary language, their clinical formulations and treatment plans of the same psychotherapy patient—one not selected or nominated by those therapists—and then to discuss points of convergence and contention in their recommendations. This special Exchange focuses on family systems psychotherapy in the case of a family presenting with the identified patient being a 5-year-old who had cried every day for 3 years since the death of her father. Therapists Catherine Fuchs and Pam Fishel-Ingram (psychodynamic orientation with some integration of cognitive–behavioral therapy concepts), George S. Greenberg (brief systemic family therapy with a strategic therapy focus), Patricia Morse (Milan school of family systems therapy), and Scott Griffies (psychoanalytic object relations) are the featured commentators. Finally, Martin Drell, the case contributor, provides a few closing comments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)