The sleep homeostatic response to sleep deprivation in humans is heritable.

STUDY OBJECTIVES: Following sleep deprivation, increases in delta power have historically been used to index increases in sleep pressure. Research in mice has demonstrated that the homeostatic delta power response to sleep deprivation is heritable. Whether this is true in humans is unknown. In the present study, we used delta power and ORP, a novel measure of sleep depth, to investigate the effects of acute sleep deprivation on sleep depth and to assess the heritability of sleep homeostasis in humans. METHODS: ORP and delta power were examined during baseline and recovery sleep following 38 h of sleep deprivation in 57 monozygotic and 38 dizygotic same-sex twin pairs. Two complementary methods were used to estimate the trait heritability of sleep homeostasis. RESULTS: During recovery sleep, ORP was lower and delta power was higher than at baseline, indicating deeper sleep. However, at the end of the recovery night, delta power reached baseline levels but ORP demonstrated incomplete recovery. Both ORP and delta power showed a broad sense heritability of sleep homeostasis following sleep deprivation. The classical approach demonstrated an h2 estimate of 0.43 for ORP and 0.73 for delta power. Mixed-effect multilevel models showed that the proportion of variance attributable to additive genetic transmission was 0.499 (95% CI = 0.316-0.682; p < .0001) for ORP and 0.565 (95% CI = 0.403-0.726; p < .0001 for delta power. CONCLUSIONS: These results demonstrate that the homeostatic response to sleep deprivation is a heritable trait in humans and confirm ORP as a robust measure of sleep depth.

Sleep disordered breathing as a cause and consequence of stroke: A review of pathophysiological and clinical relationships.

Stroke is the leading cause of death and disability globally. Sleep disordered breathing (SDB), a potentially modifiable risk factor of stroke, is highly prevalent in stroke survivors. Evidence supports a causal, bidirectional relationship between SDB and stroke. SDB may increase the risk of stroke occurrence and recurrence, and worsen stroke outcome. While SDB is associated with an increased incidence of hypertension and cardiac arrhythmias, both of which are traditional stroke risk factors, SDB is also an independent risk factor for stroke. A number of characteristics of SDB may increase stroke risk, including intermittent hypoxemia, sympathetic activation, changes in cerebral autoregulation, oxidative stress, systemic inflammation, hypercoagulability, and endothelial dysfunction. On the other hand, stroke may also cause new SDB or aggravate preexisting SDB. Continuous positive airway pressure treatment of SDB may have a beneficial role in reducing stroke risk and improving neurological outcome after stroke. The treatment should be considered as early as possible, particularly when SDB is present post-stroke. The goal of this review is to highlight the strong link between SDB and stroke and to raise awareness for practitioners to consider the possibility of SDB being present in all stroke survivors.

Prevalence of dengue virus in Aedes mosquitoes during dry season by semi-nested reverse transcriptase-polymerase chain reaction (semi-nested RT-PCR).

Dengue hemorrhagic fever remains a major health concern in Thailand. Much effort has focused on the prevention and control of the disease. Detection of dengue virus infection rate in mosquitoes would evaluate dengue control programs and predict the epidemics of dengue hemorrhagic fever. To determine dengue virus infection rate in mosquitoes by Semi-nested RT-PCR. A total of 400 mosquitoes were collected from Rom Kao Community representing a crowded community and another 9 non-crowded communities in Bangkok. Mosquitoes were then divided into 40 pools, each contained 10 mosquitoes. A total of 391 Aedes aegypti and 9 Aedes albopictus were screened for dengue virus. The mosquito infection rate in the Rom Klao community was 5% of the mosquito pool equal to that found in non-crowded communities. Both groups were found to have dengue virus serotype 3. The present study suggests a circulation of dengue virus serotype 3 in both crowded and non-crowed communities, the infection rates of which are indifferent during the dry season.