Compensatory rebound of body movements during sleep, after asphyxia in neonatal rats

OBJETIVO: A utilidade dos movimentos corporais (MC) que ocorrem durante o sono para diagnosticar e predizer as conseqüências, em longo prazo, da asfixia perinatal é contraditório. Este estudo investigou se ratos recém-nascidos (RN) manifestam MC em resposta compensatória à asfixia, e se estas alterações podem ter alguma importância na sua patogênese. MÉTODOS: Oito ratos RN (6-48h de vida) foram submetidos à implantação de pequenos eletrodos para registros da eletromiografia e eletrocardiografia. Os MC e a freqüência cardíaca (FC) foram registrados durante períodos de 30 min: fase controle (F1), fases de asfixia (F2; F3) e fase de recuperação pós-asfixia (F4). A asfixia foi promovida pelo envolvimento completo do animal com uma lâmina de polivinil. RESULTADOS: A FC diminuiu progressivamente durante F2 e F3 até a bradicardia. em F2 houve grande agitação dos animais e aumento dos períodos de vigília. em F3 houve redução significante dos MC de 12,5 ± 0,5 (Md ± SE/2min) para 9,0 ± 0,44 (P<0,05). A freqüência dos MC aumentou em F4 para 15,0 ± 0,49. CONCLUSÃO: Estes dados mostram que ratos RN com asfixia apresentam MC compensatórios durante o sono que podem ajudar no diagnóstico desta afecção e de outros problemas relacionados aos parâmetros do sono.

Evaluation of obstructive sleep apnea in obese patients scheduled for bariactric surgery

PURPOSE: To evaluate the frequency of obstructive sleep apnea (OSA) in obese patients scheduled for bariatric surgery and their identification for risk of OSA by Berlin Questionnaire (BQ) and excessive daytime sleepiness by Epworth Sleepiness Scale (ESS). METHODS: Fifty nine patients were evaluated by BQ and ESS. Out of these individuals, 35 performed a full-night sleep study using a type 3 portable monitoring (PM). The questionnaire results were compared for gender and BMI. The presence and severity of OSA was correlated with gender and both questionnaires. RESULTS: 94.75% of the respondents presented high risk for OSA by BQ and 59.65% presented positivity by ESS. Taking into account the AHI> 5 per hour for OSA diagnosis, all of them presented OSA, average AHI of 45.31±26.3 per hour and 68.6% have severe OSA (AHI>30). The male patients had a higher AHI (p<0.05). There was a positive correlation between the positivity in both questionnaires as well as the severity of OSA measured by AHI (p<0.05). CONCLUSION: The frequency and severe obstructive sleep apnea in the studied group is high. The Berlin Questionnaire and Epworth Sleepiness Scale had a positive correlation with the diagnosis of OSA in the group studied.

Sleep patterns of day-working, evening high-schooled adolescents of São Paulo, Brazil

Children who grow up in developing countries of the world must work to help financially support their families, and they must also attend school. We investigated the impact of work on the sleep of working vs. nonworking high school students. Twenty-seven São Paulo, Brazil, public high school students (eight male and eight female working students plus six nonworking female and five nonworking male students) 14-18 yrs of age who attended school Monday-Friday between 19:00 to 22:30h participated. A comprehensive questionnaire about work and living conditions, health status, and diseases and their symptoms was also answered. The activity level and rest pattern (sleep at night and napping during the day) were continuously assessed by wrist actigraphy (Ambulatory Monitoring, USA). The main variables were analyzed by a two-factor ANOVA with application of the Tukey HSD test for multiple comparisons, and the length of sleep during weekdays vs. weekends was compared by Student t-test. Working students went to sleep earlier weekends [F-(1,F-23) = 6.1; p = 0.02] and woke up earlier work days than nonworking students [F-(1,F-23) = 17.3; p = 0.001]. The length of nighttime sleep during weekdays was shorter among all the working [F-(1,F-23) = 16.7; p < 0.001] than all the nonworking students. The sleep duration of boys was shorter than of girls during weekends [F-(1,F-23) = 10.8; P < 0.001]. During weekdays, the duration of napping by working and nonworking male students was shorter than nonworking female students. During weekdays, working girls took the shortest naps [F-(1,F-23) = 5.6; p = 0.03]. The most commonly reported sleep complaint during weekdays was difficulty waking up in the morning [F-(1.23) = 6.5; p = 0.02]. During weekdays, the self-perceived sleep quality of working students was worse than nonworking students [F-(1,F-23) = 6.2; p = 0.02]. The findings of this study show that work has negative effects on the sleep of adolescents, with the possible build-up of a chronic sleep debt with potential consequent impact on quality of life and school learning.

Food deprivation and hypothermia in desynchronized sleep-deprived rats

Reports of the effect of desynchronized sleep (DS) deprivation on body temperature (Tb) of rats in the literature are contradictory. Since conspicuous body weight loss is common in such deprivation, the effect of food plus DS deprivation on Tb of adult male Wistar rats was studied. DS deprivation carried out by the small platform method with food ad libitum(N = 8) induced hyperthermia (Tb above 38.5 degrees C) in 1 to 3 rats daily until the 8th day, when a case of discrete hypothermia (Tb below 36.9 degrees C) appeared. Food deprivation alone started to induce hypothermia on the third day in one (20%) out of five rats. Fasting imposed from the 5th to the 8th day of DS deprivation (N = 12) caused hypothermia in 33% and 67% ofthe animals on the second and third day of starvation, respectively. DS compensatory manifestations in 6 starved rats intensified (N = 2) or precipitated (N = 2) hypothermia after the end of sleep deprivation. It is concluded that the hypothermia is not a primary effect of DS deprivation, and this state of sleep seems to have its particular functional role which is independent of thermoregulation.

Sleep-wake patterns of student workers and non-workers

Adolescents usually exhibit late sleep phase and irregular sleep patterns. As a result, they do not get enough sleep and report daytime sleepiness. This condition could be aggravated in working students who have a more limited time for sleep. In this survey, we investigated the impact of evening classes and employment on the sleep patterns of adolescents. We compared female (n = 17) and male (n = 14) non-worker students to female (n = 28) and male (n = 20) worker students who attended the same high school. The volunteers (aged 17.4 years +/- 11 months) answered a sleep log during a 16-day period. Worker students slept and woke up earlier, had a shorter nocturnal sleep length and a shorter daily (nocturnal plus diurnal) sleep length compared to non-working pupils. The four groups of students delayed sleep onset time on weekends, but only worker students delayed wake-up time on Sundays. The wake-up time was similar among groups on Sundays. While student workers tended to increase the sleep length in the weekends, non-working students increased it on Mondays and/or Tuesdays. The results showed that sleep schedules and sleep length were different according to the work status. Going to bed later on Saturday by the four groups of students suggests the influence of social activities, while a later wake-up time on Sundays could result from a shorter sleep length on workdays.

The influence of study schedules and work on the sleep-wake cycle of college students

College students usually exhibit an irregular sleep-wake cycle characterized by great phase delays on weekends and short sleep length on weekdays. As the temporal organization of social activities is an important synchronizer of human biological rhythms, we investigated the role played by study's schedules and work on the sleep-wake cycle. Three groups of female college students were investigated: (1) no-job morning group, (2) no-job evening group, (3) job evening group. The volunteers answered a sleep questionnaire in the classroom. The effects of day of the week and group on the sleep schedules and sleep length were analyzed by a two way ANOVA for repeated measures. The three groups showed delays in the wake up time on weekends. No-job evening and morning groups also delayed bedtime, but the job evening group slept at the same time on weekdays as on weekends. Sleep length increased on weekends for morning group and job evening group, whereas the no-job evening group maintained the amount of sleep from weekdays to weekends. This survey showed that the tendency of phase delay on weekends was differently expressed according to study's schedules and work.

Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

Background: Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances.Methods/Design: An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow.Discussion: Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers.

Sleep duration in elderly obese patients correlated negatively with intake fatty

Study objectives: The purpose of the present study was to evaluate the relationship between sleep duration and dietary habits in elderly obese patients treated at an institute of cardiology.Methods: The fifty-eight volunteers were elderly patients with obesity (classified as obese according to BMI) of both genders, between 60 and 80 years of age. All participants were subjected to assessments of food intake, anthropometry, level of physical activity, and duration of sleep.Results: The men had significantly greater weight, height, and waist circumference than women. Sleep durations were correlated with dietary nutrient compositions only in men. We found a negative association between short sleep and protein intake (r = -0.43; p = 0.02), short sleep and monounsaturated fatty acids intake (r = -0.40; p = 0.03), and short sleep and cholesterol dietary intake (r = -0.50; p = 0.01).Conclusions: We conclude that mainly in men, volunteers that had short sleep duration showed a preference for high energy-density as fatty food, at least in part, may explain the relationship between short sleep duration and the development of metabolic abnormalities.

Sleep apnea and automobile accidents: Review of regulation for drivers

Several studies show a crescent association between sleep-disordered breathing, excessive sleepiness and automobile accidents. Many countries already discussed about specific regulations for drivers with these conditions, including questionnaire and/or investigation by a qualified specialist. In Brazil, these discussions have barely begun. In view of that, we suggest some items to be included in our traffic law.

The reproductive cycle of the male sleep snake Sibynomorphus mikanii (Schlegel, 1837) from southeastern brazil

This study describes the male reproductive cycle of Sibynomorphus mikanii from southeastern Brazil considering macroscopic and microscopic variables. Spermatogenesis occurs during spring-summer (September-December) and spermiogenesis or maturation occurs in summer (December-February). The length and width of the kidney, the tubular diameter, and the epithelium height of the sexual segment of the kidney (SSK) are larger in summer-autumn (December-May). Histochemical reaction of the SSK [periodic acid-Schiff (PAS) and bromophenol blue (BB)] shows stronger results during summer-autumn, indicating an increase in the secretory activity of the granules. Testicular regression is observed in autumn and early winter (March-June) when a peak in the width of the ductus deferens occurs. The distal ductus deferens as well as the ampulla ductus deferentis exhibit secretory activities with positive reaction for PAS and BB. These results suggest that this secretion may nourish the spermatozoa while they are being stored in the ductus deferens. The increase in the Leydig cell nuclear diameter in association with SSK hypertrophy and the presence of sperm in the female indicate that the mating season occurs in autumn when testes begin to decrease their activity. The peak activity of Leydig cells and SSK exhibits an associated pattern with the mating season. However, spermatogenesis is dissociated of the copulation characterizing a complex reproductive cycle. At the individual level, S. mikanii males present a continuous cyclical reproductive pattern in the testes and kidneys (SSK), whereas at the populational level the reproductive pattern may be classified as seasonal semisynchronous. © 2012 Wiley Periodicals, Inc.