| sleep-wake states and their regulatory mechanisms throughout early human development. | the emergence of sleep states is one of the most significant aspects of development. descriptions of both neonatal and late fetal behavior and studies on the organization of sleep have shown that fetus and newborns exhibit spontaneously discrete and cyclic patterns of active sleep (as) and quiet sleep (qs). human fetuses and neonates sleep most of their life, and as is the prevailing state even during the first postnatal months. several hypotheses to explain central nervous system development co ... | 2003 | 14597916 |
| endogenous circadian control of the human autonomic nervous system. | to determine if an endogenous circadian rhythmicity, independent from sleep/wake cycles, exists in autonomic nervous system (ans) function, heart rate variability analysis of electrocardiogram r-r intervals was applied to data collected during a 27-day forced desynchrony protocol. results during wakefulness indicate that the circadian pacemaker may control both the sympathetic and vagal limbs of the ans. vagal tone was maximal during the circadian phase corresponding to the usual sleep episode ( ... | 2000 | 14632012 |
| anomia for people's names, a restricted form of transient epileptic amnesia. | a 37-year-old man consulted after two episodes of transient anomia for people's names over a period of 6 months. the first episode lasted about 10 min and was restricted to an inability to remember his 2-year-old son's first name. the second, was limited to an inability to recall his daughter's first name for 5 min with clear abnormal experiential quality. witnessed descriptions of the attacks confirmed the absence of any other cognitive impairment or motor automatisms. the neurological examinat ... | 2003 | 14641509 |
| sleep-dependent theta oscillations in the human hippocampus and neocortex. | hippocampal theta waves recorded during rapid eye movement (rem) sleep are thought to play a critical role in memory consolidation in lower mammals, but previous attempts to detect similar theta oscillations in the human hippocampus have been unsuccessful. using subdural and depth recordings from epileptic patients, we now report the first evidence of state-dependent hippocampal theta waves (4-7 hz) in humans. unlike the continuous theta in rodents, however, these oscillations were consistently ... | 2003 | 14645485 |
| the role of the hypocretinergic system in the integration of networks that dictate the states of arousal. | recent studies have led to the discovery of a neuropeptide system that regulates arousal states. the hypocretins (hcrt1 and hcrt2, also called the orexins) are neuropeptides of related sequence derived from the same precursor whose expression is restricted to a few thousand neurons of the lateral hypothalamus. two g-protein-coupled receptors for the hypocretins have been identified, and these have different distributions within the central nervous system and differential affinities for the two h ... | 2003 | 14668948 |
| [sleep evolution from fetal life to adulthood: respiratory and neurologic aspects] | objective: this article has the purpose of presenting some basic concepts about sleep, besides offering a brief review of the main ventilatory and neurologic changes during sleep, from fetal life up to adulthood. methods: bibliographic review of international literature including original articles and textbook chapters.results: the sleep-wake cycle undergoes changes from fetal life to adolescence, both in duration (the fetus sleeps most of the time in utero, and the adult sleeps about 8 hours a ... | 1998 | 14685595 |
| correlation between the ki-67 antigen in the brainstem and physiological data on sleep apnea in sids victims. | the ki-67 antigen appears in all human proliferating cells during late g1, s, m and g2 phases of the cell cycle, but is consistently absent in the go phase (noncycling) cells. the correlation between ki-67 in the brainstem and sleep apnea in victims of the sudden infant death syndrome (sids) was investigated to elucidate cell kinetics in the brainstem of this condition, which is still the main cause of postneonatal infant death. | 2003 | 14693398 |
| sleep apnea in mice: a useful animal model for study of sids? | although the incidence of sudden infant death syndrome (sids) has been decreased by education programs to avoid sleeping in prone position, the pathological mechanisms of sids have not fully been understood. basic research on sleep apnea using experimental animals may help further understanding and prevention of sids because the syndrome is thought as inability to wake up from respiratory arrest (apnea) during sleep. although several animal models of sleep apnea have been described previously, m ... | 2003 | 14693402 |
| the cook, the thief, his wife and her lover: on the evolution of the human reproductive strategy. | human reproductive strategy differs from that of most other mammals, including apes such as the closely related chimpanzee (pan troglodytes) and the bonobo (pan paniscus). for example, humans, although basically polygamic, exhibit a strong tendency to (serial) monogamy and--very rare for a mammal--provide biparental care. moreover, humans are (almost) permanently willing to mate but, in contrast to other species, do so only in private. unlike chimpanzees and bonobos, the human female exhibits no ... | 2003 | 14702888 |
| melatonin in patients with reduced rem sleep duration: two randomized controlled trials. | recent data suggest that melatonin may influence human physiology, including the sleep-wake cycle, in a time-dependent manner via the body's internal clock. rapid-eye-movement (rem) sleep expression is strongly circadian modulated, and the impact of rem sleep on primary brain functions, metabolic processes, and immune system function has become increasingly clear over the past decade. in our study, we evaluated the effects of exogenous melatonin on disturbed rem sleep in humans. fourteen consecu ... | 2004 | 14715839 |
| design and validation of a computer-based sleep-scoring algorithm. | a computer-based sleep scoring algorithm was devised for the real time scoring of sleep-wake state in wistar rats. electroencephalogram (eeg) amplitude (microv(rms)) was measured in the following frequency bands: delta (delta; 1.5-6 hz), theta (theta; 6-10 hz), alpha (alpha; 10.5-15 hz), beta (beta; 22-30 hz), and gamma (gamma; 35-45 hz). electromyographic (emg) signals (microv(rms)) were recorded from the levator auris longus (neck) muscle, as this yielded a significantly higher algorithm accur ... | 2004 | 14757347 |
| the threat and prospects for control of an influenza pandemic. | influenza constitutes the most widespread and significant respiratory infectious disease in the world, resulting in increased morbidity, mortality and economic loss each epidemic year. pandemic influenza is a worldwide epidemic usually caused by a new virus variant to which the majority of the population has no immunity. as demonstrated in the devastating pandemic of 1918 to 1919, a pandemic virus may infect 30 to 50% of the worlds population and kill 1 to 2% of those infected. pandemic control ... | 2004 | 14761242 |
| insurance and epidemics: sars, west nile virus and nipah virus. | severe acute respiratory syndrome (sars) reminds us that sudden disease emergence is a permanent part of our world--and should be anticipated in our planning. historically the emergence of new diseases has had little or no impact beyond a small, localized cluster of infections. however, given just the right conditions, a highly virulent pathogen can suddenly spread across time and space with massive consequences, as has occurred on several occasions in human history. in the wake of the sars outb ... | 2003 | 14971089 |
| demonstration of an orexinergic central innervation of the pineal gland of the pig. | orexins/hypocretins, two isoforms of the same prepropeptide, are widely distributed throughout the brain and are involved in several physiological and neuroendocrine regulatory patterns, mostly related to feeding, sleep, arousal, and cyclic sleep-wake behaviors. orexin-a and orexin-b bind with different affinities to two g-protein-coupled transmembrane receptors, orexin-1 and orexin-2 receptors (or-r1 and or-r2, respectively). because of the similarities between the human and the swine brain, we ... | 2004 | 14986306 |
| twenty-four-hour disruption of the sleep-wake cycle and sleep-onset rem-like episodes in a rat model of african trypanosomiasis. | patients with human african trypanosomiasis (sleeping sickness) due to the inoculation of trypanosoma brucei gambiense or rhodesiense show a major disruption of the 24-hour sleep-wake distribution, accompanied by the occurrence of sleep-onset rapid-eye-movement (rem) sleep episodes, proportional to the severity of the illness. although animal models of human african trypanosomiasis have been developed to understand the pathogenic mechanisms leading to immune alterations, the development of an an ... | 2004 | 14998236 |
| regulating the health care workforce: next steps for research. | this article explores the recent ferment surrounding professional self-regulation in medicine and other health professions. it reviews the academic literature and sets out an agenda for research. the first section considers definitions, acknowledging the particularly complex regulatory maze in uk health care at present, in which professional self-regulation is only one part. the second section reviews academic writing, currently dispersed among the disciplines. 'the logic of light touch regulati ... | 2004 | 15006229 |
| the role of chronobiology in sleep disorders medicine. | this review is concerned with circadian (approximately 24 h) aspects of chronobiology, and how they relate to sleep disorders medicine. we begin with an introduction to the key concepts and paradigms of circadian rhythms research in general, including a description of homeostatic and circadian determinants of sleep timing. this is followed by a brief history of chronobiology in relation to sleep disorders medicine. both animal and human circadian rhythm studies are considered. we trace historica ... | 2003 | 15018090 |
| summary of the key features of seven biomathematical models of human fatigue and performance. | biomathematical models that quantify the effects of circadian and sleep/wake processes on the regulation of alertness and performance have been developed in an effort to predict the magnitude and timing of fatigue-related responses in a variety of contexts (e.g., transmeridian travel, sustained operations, shift work). this paper summarizes key features of seven biomathematical models reviewed as part of the fatigue and performance modeling workshop held in seattle, wa, on june 13-14, 2002. the ... | 2004 | 15018262 |
| critical research issues in development of biomathematical models of fatigue and performance. | this article reviews the scientific research needed to ensure the continued development, validation, and operational transition of biomathematical models of fatigue and performance. these models originated from the need to ascertain the formal underlying relationships among sleep and circadian dynamics in the control of alertness and neurobehavioral performance capability. priority should be given to research that further establishes their basic validity, including the accuracy of the core mathe ... | 2004 | 15018283 |
| protecting america's secrets while maintaining academic freedom. | the terrorist attacks of september 11, 2001, and the subsequent anthrax mail attacks, have had a profound impact on americans' personal and professional lives and have sparked an active debate regarding the delicate balance between the need for national security and the pursuit of academic freedom. although academic freedom can be defined in many ways, there are four primary tenets of freedom in an academic environment: freedom to research, freedom to publish, freedom to teach, and freedom to sp ... | 2004 | 15044166 |
| polysomnography in transgenic hsod1 mice as down syndrome model. | sleep-wake homeostasis is crucial for behavioral performances and memory in the general population and in learning disability populations among them down syndrome patients. we investigated, in a mouse model of down syndrome, cortical eeg and sleep-wake architecture under baseline conditions and after a 4 hr sleep deprivation (sd). young heterozygous transgenic mice (s/+) for the human cu/zn superoxide dismutase (hsod-1) were obtained on fvb/n background. baseline records for slow wave sleep (sws ... | 2003 | 15068249 |
| the history of epidemic typhus. | few infectious diseases have influenced human civilization to the same degree as louse-transmitted typhus. rickettsia prowazekii continues to strikes tens to hundreds of thousands of persons who live with war, famine, crowding, and in squalid conditions associated with social unrest, with mortality rates in excess of 10% to 15%. historical documents confirm that such devastation has been a continuous feature of human existence to the extent that typhus has been a major determinant in the outcome ... | 2004 | 15081509 |
| role of orexin and prostaglandin e(2) in activating histaminergic neurotransmission. | although the molecular mechanisms underlying the control of sleep have been extensively studied in the past, relatively little attention has been paid to the regulatory mechanisms involved in the maintenance and control of wakefulness until today. in this article, recent developments leading to our better understanding of the arousal system will be reviewed with the main emphasis on three messengers: histamine, prostaglandin e(2) and orexin. the results reported herein may provide new insights i ... | 2004 | 15098064 |
| beyond informed consent: the ethical design of pain research. | in the wake of the rapid development of medical research over the past 50 years, investigators, clinicians, and ethicists have raised numerous concerns about the ethical conduct of research. perhaps the single most important protective mechanism to emerge from the fray has been the requirement of informed consent. certainly it has the longest history. however, even though informed consent has become the most widely recognized mechanism of protecting human subjects in research, there are limits t ... | 2001 | 15102303 |
| avian influenza: a wake-up call from birds to humans. | | 2004 | 15117165 |
| anterior cruciate ligament injuries among wakeboarders: a case report. | no previous cases of anterior cruciate ligament (acl) injuries sustained during wake-boarding have been reported. we report on a case involving an acl injury sustained during wakeboarding. a 27-year-old man sustained an injury while attempting a wakeboarding maneuver(a heel-side back roll, consisting of a jump and simultaneous roll toward the heel side). he failed to complete his roll before landing, striking the water with his right shoulder foremost, then plunging underwater. when his wakeboar ... | 2004 | 15129597 |
| sleep disturbances in angelman syndrome: a questionnaire study. | only few studies are available on sleep disorders in angelman syndrome (as), a neurodevelopmental disorder with several behavior disturbances. the aim of this study was to determine the prevalence of sleep disorders in a relatively large group of as subjects, compared to that of age-matched controls. forty-nine consecutive parents of patients with as (26 males and 23 females aged 2.3-26.2 years) were interviewed and filled out a comprehensive sleep questionnaire. based on their genetic etiology, ... | 2004 | 15130689 |
| reciprocal interactions between the gh axis and sleep. | for more than 30 years, growth hormone (gh) has been observed to be preferentially secreted during deep, slow-wave sleep (sws). however, the mechanisms that underlie this robust relationship that links anabolic processes in the body with behavioral rest and decreased cerebral metabolism remain to be elucidated. current evidence indicates that gh secretion during the beginning of sleep appears to be primarily regulated by gh-releasing hormone (ghrh) stimulation occurring during a period of relati ... | 2004 | 15135771 |
| sleep, but not febrile responses of fisher 344 rats to immune challenge are affected by aging. | sleep is altered in response to infection and immune challenge in humans and non-human animals. although there are changes in sleep and facets of immune function with aging, sleep responses of aged subjects to immune challenge have received little, if any attention. to test the hypothesis that aging affects sleep responses to immune challenge, intracerebroventricular injections of interleukin 1 (il-1) were given to young and aged rats and subsequent sleep-wake behavior was determined. under basa ... | 2004 | 15157957 |
| [results of vacuum therapy (v.a.c.) of superficial and deep dermal burns]. | basis: this prospective multi-centre study in co-operation with the wake forrest university covered the area of applications for treatment of fresh, superficial and deep dermal burns and scalds (grade ii a-b). the micro-circulation relationships, wound healing time, extent of germ settlement and the connective tissue edema were of particular interest (together with the increase or decrease in burn depth). moreover, the economical aspects were compared with conservative therapy. | 2004 | 15168289 |
| does leptin link sleep loss and breathing disturbances with major public diseases? | leptin is best known as a regulator of energy homeostasis, but it also interacts with sleep and breathing. leptin secretion increases at night and decreases during the day. the circadian secretory profile of leptin is determined both by the hypothalamic circadian pacemaker and sleep-wake cycle. leptin is also a powerful respiratory stimulant. serum leptin levels are higher in obstructive sleep apnoea syndrome but lower during extended sleep deprivation in healthy subjects or in narcolepsy. abnor ... | 2004 | 15181973 |
| a missense variation in human casein kinase i epsilon gene that induces functional alteration and shows an inverse association with circadian rhythm sleep disorders. | recent studies have shown that functional variations in clock genes, which generate circadian rhythms through interactive positive/negative feedback loops, contribute to the development of circadian rhythm sleep disorders in humans. another potential candidate for rhythm disorder susceptibility is casein kinase i epsilon (ckiepsilon), which phosphorylates clock proteins and plays a pivotal role in the circadian clock. to determine whether variations in ckiepsilon induce vulnerability to human ci ... | 2004 | 15187983 |
| sleep-wake architecture in mouse models for down syndrome. | sleep-wake homeostasis is crucial for behavioral performances and memory both in the general population and in patients with learning disability, among whom were down syndrome (ds) patients. we investigated, in mouse models of ds, cortical eeg and sleep-wake architecture under baseline conditions and after a 4-h sleep deprivation (sd). young hemizygous mice (hsodwt/+) transgenic for the human cuzn superoxide dismutase (hsod1) or for the human amyloid precursor protein (huapp(695); happwt/+) were ... | 2004 | 15193286 |
| tools for making correct decisions regarding hormone therapy. part ii. organ response and clinical applications. | to review existing scientific knowledge of the complicated and variable behavior and response to hormone therapy (ht) of different organs during aging, and to summarize long-term consequences on human health. | 2004 | 15193461 |
| mechanistic aspects of fracture and r-curve behavior in human cortical bone. | an understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. in the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. the fracture toughness was found to rise linearly with crack extension (i.e., rising resistance- or r-curve behavior) with a mean crack-initiation toughness, k0 of approximately 2 mpa square root m f ... | 2005 | 15207469 |
| gamma eeg dynamics in neocortex and hippocampus during human wakefulness and sleep. | little is known about the neurophysiological mechanisms underlying the human sleep-wake cycle. using intracranial electrodes in humans, we investigated changes in topographic distribution of gamma power and local- and long-range gamma eeg coherence in neocortex and hippocampus during different cerebral states. we report significantly greater variability in gamma power across cortical regions during wakefulness than during either slow wave or rapid eye movement (rem) sleep. in addition, local (wi ... | 2004 | 15219599 |
| to irb or not to irb? | improving medical practice begins with the improvement of medical education. in this process, most academic medical faculty assume the dual roles of both teacher and researcher, often without intending to or realizing that they are. with the increased tightening of regulation and supervision of biomedical research in the united states, academic medical institutions and their individual faculty face the daunting regulatory compliance problems that are traditionally associated with clinical and be ... | 2004 | 15234912 |
| sleep disorders in pregnancy. | the precise function of sleep in animals and human beings is still unknown, and any sort of physical, social or psychological variation may change the normal sleep-wake cycle. | 2004 | 15235720 |
| sleep-related non epileptic motor disorders. | sleep-related non epileptic motor disorders represent a frequent but often neglected or trivialized source of neurological disability. in recent decades, the widespread adoption of videopolygraphic techniques has better characterized already known nosographic entities and described a bewildering variety of previously unrecognized clinical entities (such as rem sleep behaviour disorder, sleep-related eating disorder, benign neonatal sleep myoclonus, facio-mandibular myoclonus during sleep, fragme ... | 2004 | 15258779 |
| advanced preclinical and clinical trials of natural products and related compounds from marine sources. | the marine environment has proven to be a very rich source of extremely potent compounds that have demonstrated significant activities in anti-tumor, anti-inflammatory, analgesia, immuno-modulation, allergy and anti-viral assays. although the case can and has been made that the nucleosides such as ara-a and ara-c are derived from knowledge gained from investigations of bioactive marine nucleosides, no drug directly from marine sources (whether isolated or by total synthesis) has yet made it to t ... | 2004 | 15279577 |
| emergence and influences of circadian rhythmicity in infants. | recent evidence shows that the circadian system of primate infants is responsive to light at very premature stages and that low intensity lighting can regulate the developing clock. after birth, there is progressive maturation of the circadian system outputs, with pronounced rhythms in sleep-wake and hormone secretion generally developing after 2 months of age. showing the importance of photic regulation of circadian phase in infants, exposure of premature infants to low-intensity cycled lightin ... | 2004 | 15289029 |
| sleep, sleep disorders and hypocretin (orexin). | narcolepsy is a disabling neurologic condition affecting 1 in 2000 individuals, characterized by sleepiness, cataplexy, and transitions from wakefulness into rapid-eye-movement sleep. current treatments include amphetamine-like stimulants and antidepressants. human narcolepsy is hla-associated, multigenic, and environmentally influenced. positional cloning was used to isolate narcolepsy genes in canine families with autosomal recessive narcolepsy transmission. three mutations in the g-protein-co ... | 2004 | 15301991 |
| what can neuroimaging findings tell us about sleep disorders? | models of the pathophysiology of human sleep disorders have only recently been tested using nuclear medicine assessments, which have greatly increased our understanding of the brain mechanisms involved in the human sleep-wake cycle. dramatic changes in function have been observed in large-scale neuronal networks during sleep. broad declines in heteromodal-association-cortical function, and relative increases in limbic and paralimbic function have been observed. these cortical areas are responsib ... | 2004 | 15301993 |
| evoked potentials as a tool for the investigation of human sleep. | this review summarizes studies of evoked potentials (eps) applied to the investigation of human sleep and of sleep disorders. the first part is devoted to studies dealing with the nature, mechanisms and extent of information processing during sleep. ep studies suggest that the brain's ability to detect salient stimuli persists during even the deepest sleep stages, while discrimination of the stimulus' intrinsic significance and/or semantic content may persist only in stage ii and paradoxical sle ... | 1999 | 15310488 |
| [effect of intraocular pressure and arterial blood pressure variations on glaucoma progression]. | the purpose of this paper is to collect data describing the implication of intraocular pressure (iop) and arterial blood pressure in the progression of glaucoma. | 2004 | 15314572 |
| infradian rhythmicity in sleep/wake ratio in developing infants. | although there are several reports on ultradian and circadian rhythms in newborns, we found only one report in which infradian periodicities are described for heart-rate measurements in the early stages of human development. here, we report infradian rhythms in the monthly range in the sleep/wake cycle of four infants studied along 24 consecutive weeks. our procedure was applied to sleep diary records from four healthy newborns. the data were arranged in binary time series representing sleep (-1 ... | 2004 | 15332343 |
| genetic variability of arylalkylamine-n-acetyl-transferase (aa-nat) gene and human sleep/wake pattern. | the cyclic production and secretion of melatonin has been associated with the sleep/wake cycle as well as other circadian rhythms. since arylalkylamine-n-acetyl-transferase (aa-nat) is the rate-limiting enzyme responsible for the production of melatonin, it has been postulated to determine the circadian oscillations of melatonin. genetic variability of the aa-nat gene may therefore potentially influence sleep patterns in the normal population. in this study, a sleep pattern survey was performed ... | 2004 | 15332344 |
| the mammalian circadian timing system: from gene expression to physiology. | many physiological processes in organisms from bacteria to man are rhythmic, and some of these are controlled by self-sustained oscillators that persist in the absence of external time cues. circadian clocks are perhaps the best characterized biological oscillators and they exist in virtually all light-sensitive organisms. in mammals, they influence nearly all aspects of physiology and behavior, including sleep-wake cycles, cardiovascular activity, endocrinology, body temperature, renal activity ... | 2004 | 15338234 |
| modeling the mammalian circadian clock: sensitivity analysis and multiplicity of oscillatory mechanisms. | we extend the study of a computational model recently proposed for the mammalian circadian clock (proc. natl acad. sci. usa 100 (2003) 7051). the model, based on the intertwined positive and negative regulatory loops involving the per, cry, bmal1, and clock genes, can give rise to sustained circadian oscillations in conditions of continuous darkness. these limit cycle oscillations correspond to circadian rhythms autonomously generated by suprachiasmatic nuclei and by some peripheral tissues. by ... | 2004 | 15363675 |
| overexpression of the human beta-amyloid precursor protein downregulates cortistatin mrna in pdapp mice. | we measured preprocortistatin mrna expression in young and aged transgenic (tg) mice overexpressing the human beta-amyloid precursor protein (hbetaapp) under the platelet-derived growth factor-beta promoter. our findings suggest that the significant increase in hippocampal cortistatin mrna expression during normal aging is significantly attenuated in tg mice at an age known to exhibit beta-amyloid protein (abeta) deposition. these deficits in cortistatin expression may play a role in the deficit ... | 2004 | 15364032 |
| social influences on mammalian circadian rhythms: animal and human studies. | while light is considered the dominant stimulus for entraining (synchronizing) mammalian circadian rhythms to local environmental time, social stimuli are also widely cited as 'zeitgebers' (time-cues). this review critically assesses the evidence for social influences on mammalian circadian rhythms, and possible mechanisms of action. social stimuli may affect circadian behavioural programmes by regulating the phase and period of circadian clocks (i.e. a zeitgeber action, either direct or by cond ... | 2004 | 15366762 |
| post-traumatic ossification of the achilles tendon: description of a case. | the presence of small areas of ossification in the achilles tendon is a relatively frequent finding. it is instead rare to find large, extensive ossifications for more than half of the tendon. the authors describe a case of a man aged 45 years who, in the wake of an unknown lesion of the achilles tendon, developed clinically symptomatic ossification 9.5 cm in length and 2.3 cm in width. the patient was treated surgically by removal of the ossified portion and repair of the diastasis with a proxi ... | 2004 | 15382586 |
| spectral power time-courses of human sleep eeg reveal a striking discontinuity at approximately 18 hz marking the division between nrem-specific and wake/rem-specific fast frequency activity. | spectral power time-courses over the ultradian cycle of the sleep electroencephalogram (eeg) provide a useful window for exploring the temporal correlation between cortical eeg and sub-cortical neuronal activities. precision in the measurement of these time-courses is thus important, but it is hampered by lacunae in the definition of the frequency band limits that are in the main based on wake eeg conventions. a frequently seen discordance between the shape of the beta power time-course across t ... | 2005 | 15459085 |
| stereological analysis of the hypothalamic hypocretin/orexin neurons in an animal model of depression. | affective disorders often occur in combination with disrupted sleep-wake cycles and abnormal fluctuations in hypothalamic neurotransmitters. hypocretin (orexin) is a hypothalamic neuropeptide linked to narcolepsy, a sleep-related disorder characterized by profound disturbances in the normal sleeping pattern and variable degrees of depression. wistar-kyoto (wky) rats exhibit depressive characteristics and patterns of sleep disruption similar to that observed in depressed human patients. in this s ... | 2004 | 15464197 |
| acute wake-promoting actions of jnj-5207852, a novel, diamine-based h3 antagonist. | 1 1-[4-(3-piperidin-1-yl-propoxy)-benzyl]-piperidine (jnj-5207852) is a novel, non-imidazole histamine h3 receptor antagonist, with high affinity at the rat (pki=8.9) and human (pki=9.24) h3 receptor. jnj-5207852 is selective for the h3 receptor, with negligible binding to other receptors, transporters and ion channels at 1 microm. 2 jnj-5207852 readily penetrates the brain tissue after subcutaneous (s.c.) administration, as determined by ex vivo autoradiography (ed50 of 0.13 mg kg(-1) in mice). ... | 2004 | 15466448 |
| [systemic manifestations of parvovirus b19 infections]. | purpose: parvovirus b19 (b19) causes many clinical disorders, of which the most common are erythema infectiosum, aplastic crisis complicating chronic hemolytic anemia, and hydrops fetalis. in young adults, the skin eruption caused by b19 is accompanied by polyarthritis and polyarthralgia in 60% of the cases. rheumatoid factors and other antibodies including antinuclear antibodies, anti-adn, and antiphospholipids can be produced in the wake of b19 infection. current knowledge and key points: thes ... | 2004 | 15471600 |
| bi-directional flow sensor with a wide dynamic range for medical applications. | this paper describes a novel three-wire thermal flow sensor for medical applications. the present innovation for low-frequency measurements involves the use of a pulsed-wire anemometer with a comparatively large wire diameter (12.5 microm and larger) together with a novel signal processing approach. a small wire is heated using a sinusoidal alternating current, and two sensing wires, acting as resistance thermometers, are set parallel to, and at a small distance on either side of, the pulsed wir ... | 2004 | 15471690 |
| the human hypothalamus: a morpho-functional perspective. | historical investigation suggests that the role of the hypothalamus as a site of integration for endocrine with autonomic and behavioral responses in man rises from ideas and observations first appearing between the 14th and 18th centuries. research on human, post-mortem brains and by in vivo magnetic resonance techniques reveal that the functional morphology of the hypothalamus in man is very similar to that in rodents and primates. as such, the adult human hypothalamus can be subdivided in thr ... | 2004 | 15481807 |
| rem sleep without atonia--from cats to humans. | basic science research observations often lead to unexpected surprises. it is likely that in 1965 when dr. michel jouvet placed bilateral peri-locus coeruleus lesions in cats and observed rem sleep without atonia (rwa) and "oneiric" behavior that could only be explained by "acting out dreams" (or "dreaming out acts"), he recognized that it was an important observation, but had little inkling of its true significance. nor could he even imagine that it would lead to such greater understanding of w ... | 2004 | 15493548 |
| the clinical spectrum of narcolepsy with cataplexy: a reappraisal. | in the absence of a golden standard for the diagnosis of narcolepsy, the clinical spectrum of disorder remains controversial. the aims of this study were (1) to determine frequency and characteristics of sleep-wake symptoms in patients with narcolepsy with cataplexy, (2) to compare clinical characteristics with results of ancillary tests, and (3) to identify factors that discriminate narcolepsy from other conditions with excessive daytime sleepiness (eds). we prospectively studied 57 narcoleptic ... | 2004 | 15560774 |
| pepsin and carbonic anhydrase isoenzyme iii as diagnostic markers for laryngopharyngeal reflux disease. | the objective was to investigate the potential use of pepsin and carbonic anhydrase isoenzyme iii (ca-iii) as diagnostic markers for laryngopharyngeal reflux disease. | 2004 | 15564833 |
| the 3111t/c polymorphism of hclock is associated with evening preference and delayed sleep timing in a japanese population sample. | sleep timing is influenced by the circadian system. morningness-eveningness (me) preference in humans is affected by the free-running period, which is determined by circadian clock-relevant genes. in this study, we investigated association between the 3111t/c polymorphism in the 3'-flanking region of hclock (homo sapiens clock homolog) and me preference in 421 japanese subjects. the horne-ostberg me questionnaire (meq) scores showed normal distribution, with mean score of 51.2 +/- 1.4 (range, 25 ... | 2005 | 15578592 |
| reduced food anticipatory activity in genetically orexin (hypocretin) neuron-ablated mice. | daily restricted feeding (rf) produces an anticipatory locomotor activity rhythm and entrains the peripheral molecular oscillator independently of the central pacemaker located in the suprachiasmatic nucleus (scn). as orexins (hypocretins) are neuropeptides that coordinate sleep/wake patterns and motivated behaviours, such as food seeking, we studied the involvement of orexin in the food anticipatory activity (faa) induced by rf. daily rf shifted the mrna rhythm of a clock-controlled gene mdbp i ... | 2004 | 15579160 |
| meta-analysis of quantitative sleep parameters from childhood to old age in healthy individuals: developing normative sleep values across the human lifespan. | the purposes of this study were to identify age-related changes in objectively recorded sleep patterns across the human life span in healthy individuals and to clarify whether sleep latency and percentages of stage 1, stage 2, and rapid eye movement (rem) sleep significantly change with age. | 2004 | 15586779 |
| effect of aging on the toughness of human cortical bone: evaluation by r-curves. | age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, is responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. the present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. because cortical bone exhibits rising crac ... | 2004 | 15589205 |
| sleep structure: a new diagnostic tool for stage determination in sleeping sickness. | human african trypanosomiasis (hat), due to the transmission of trypanosoma brucei (t. b.) gambiense and t. b. rhodesiense by tsetse flies, is re-emerging in inter-tropical africa. it evolves from the hemolymphatic stage i to the meningo-encephalitic stage ii. the latter is generally treated with melarsoprol, an arseniate provoking often a deadly encephalopathy. a precise determination of the hat evolution stage is therefore crucial. stage ii patients show: (i) a deregulation of the 24-h distrib ... | 2005 | 15589803 |
| methyl parathion increases neuronal activities in the rat locus coeruleus. | exposure to organophosphate insecticides induces undesirable behavioral changes in humans, including anxiety and irritability, depression, cognitive disturbances and sleep disorders. little information currently exists concerning the neural mechanisms underlying such behavioral changes. the brain stem locus coeruleus (lc) could be a mediator of organophosphate insecticide-induced behavioral toxicities since it contains high levels of acetylcholinesterase and is involved in the regulation of the ... | 2004 | 15591769 |
| endogenous circadian rhythm in an index of cardiac vulnerability independent of changes in behavior. | there exists a robust day/night pattern in the incidence of adverse cardiac events with a peak at approximately 10 a.m. this peak traditionally has been attributed to day/night patterns in behaviors affecting cardiac function in vulnerable individuals. however, influences from the endogenous circadian pacemaker independent from behaviors may also affect cardiac control. heartbeat dynamics under healthy conditions exhibit robust complex fluctuations characterized by self-similar temporal structur ... | 2004 | 15611476 |
| [the neurobiology of sleep and its influence on memory]. | recent developments in neuroscience have increased our knowledge of the physiology of sleep and dreaming, and thus the number of studies about the influence of sleep on learning and memory have increased rapidly. in this review the objective is to assess the relationship between sleep and memory considering the evidence regarding the neurobiology of sleep and dreaming. | 2004 | 15622510 |
| dissociation in circadian rhythms in a pseudohypersomnia form of fatal familial insomnia. | the authors present clinical, sleep, and neuroendocrine features of a patient with genetically confirmed fatal familial insomnia (d178n mutation with heterozygosity at codon 129 of the prion protein gene). the patient exhibited pseudohypersomnia behavior instead of insomnia. there was profound alteration in the sleep-wake cycle with a clear dissociation in the disappearance of circadian and neuroendocrine rhythms, findings unrelated to abnormalities in the hypocretinergic system. | 2004 | 15623717 |
| treatment and control of human african trypanosomiasis. | access to treatment is a multi-step process and little progress has been made to improve treatments for sleeping sickness over the past 50 years. the current strategy is based on diagnostic tools developed in the 1960s while available drugs are still the same as those developed in the middle of the last century. strategic opportunities can only be based on two achievements: improved diagnosis and safer drugs. this paper reviews the development of new diagnostic tools and drugs and the opportunit ... | 2004 | 15640711 |
| melatonin as a chronobiotic. | melatonin, hormone of the pineal gland, is concerned with biological timing. it is secreted at night in all species and in ourselves is thereby associated with sleep, lowered core body temperature, and other night time events. the period of melatonin secretion has been described as 'biological night'. its main function in mammals is to 'transduce' information about the length of the night, for the organisation of daylength dependent changes, such as reproductive competence. exogenous melatonin h ... | 2005 | 15649736 |
| vulnerability: what kind of principle is it? | the so-called european principles of bioethics are a welcome enrichment of principlist bioethics. nevertheless, vulnerability, dignity and integrity can perhaps be more accurately understood as anthropological descriptions of the human condition. they may inspire a normative language, but they do not contain it primarily lest a naturalistic fallacy be committed. these anthropological features strongly suggest the need to develop deontic arguments in support of the protection such essential attri ... | 2004 | 15679020 |
| circadian rhythms: from the bench to the bedside and falling asleep. | the discovery of the molecular core machinery underlying the generation of circadian rhythms in mammals, and the ability to alter the genes and protein products that comprise the circadian clock, has led to a new appreciation of the role of the clock in regulating many parameters of the sleep-wake cycle, beyond just the timing of sleep. the journal, sleep, with its mission of publishing papers on basic and translational research in the field of sleep, is in an ideal position to insure that advan ... | 2004 | 15683151 |
| [ghrelin--structure, function and clinical applications]. | ghrelin is a peptidic hormone composed of 28 aminoacid residues. it is produced by enteroendocrine cells of stomach and intestine. it is also produced in pancreas, kidney, placental tissue, thyroid gland, hypothalamus, and hypophysis. gastrectomy leads to 65-80% decrease of plasma levels of ghrelin. in human organism, ghrelin stimulates secretion of growth hormone, prolactin, and acth. ghrelin also has orexigenic activity (increases food intake), influences the sleep/wake cycle, gastric motility ... | 2004 | 15709643 |
| the human pineal gland and melatonin in aging and alzheimer's disease. | the pineal gland is a central structure in the circadian system which produces melatonin under the control of the central clock, the suprachiasmatic nucleus (scn). the scn and the output of the pineal gland, i.e. melatonin, are synchronized to the 24-hr day by environmental light, received by the retina and transmitted to the scn via the retinohypothalamic tract. melatonin not only plays an important role in the regulation of circadian rhythms, but also acts as antioxidant and neuroprotector tha ... | 2005 | 15725334 |
| assessment of modafinil on attentional processes in a five-choice serial reaction time test in the rat. | it is well known that modafinil is an effective wake-promoting agent, but there is growing evidence to suggest that modafinil may also enhance some aspects of cognition. in man, modafinil has been shown to enhance vigilance in sleep-deprived and/or narcoleptic subjects and also to improve executive-type functioning (predominantly inhibitory response control processes) across a variety of human patient population groups. preclinically, a delay-dependent improvement has been reported with modafini ... | 2005 | 15728436 |
| genetics of normal and pathological sleep in humans. | the complexity of sleep-wake regulation, in addition to the many environmental influences, includes genetic predisposing factors, which begin to be discovered. most of the current progress in the study of sleep genetics comes from animal models (dogs, mice, and drosophila). multiple approaches using both animal models and different genetic techniques are needed to follow the segregation and ultimately to identify 'sleep genes' and molecular bases of sleep disorders. recent progress in molecular ... | 2005 | 15737788 |
| development and characterization of a wake-controlled exterior hood. | a wake-controlled exterior hood was developed to overcome the negative influence of cross draft on an exterior hood and avoid the operation inconvenience caused by the enclosure of an airflow capture booth. this new type of local exterior hood used the hood suction flow to stabilize the dynamic vortex shedding that was induced when a crossflow passed over a blockage plate, and therefore formed a hydrodynamics-stabilized local isolation area for efficient removing of the contaminant. the developm ... | 2004 | 15742706 |
| human parahippocampal activity: non-rem and rem elements in wake-sleep transition. | the covert-rapid-eye-movement (rem) sleep hypothesis of dreaming suggests that elements of rem sleep emerge during sleep onset, leading to vivid hypnagogic imagery. based on parahippocampal electrocorticography of epileptic patients we found an increase in rem-like 1.5-3.0 hz parahippocampal activity during wake-sleep transition, which peaks after on average 30s of sleep onset, and reaches 82% of rem sleep value. the increase in 1.5-3.0 hz parahippocampal activity followed alpha dropout, but did ... | 2005 | 15763184 |
| neurocognitive consequences of sleep deprivation. | deficits in daytime performance due to sleep loss are experienced universally and associated with a significant social, financial, and human cost. microsleeps, sleep attacks, and lapses in cognition increase with sleep loss as a function of state instability. sleep deprivation studies repeatedly show a variable (negative) impact on mood, cognitive performance, and motor function due to an increasing sleep propensity and destabilization of the wake state. specific neurocognitive domains including ... | 2005 | 15798944 |
| inhibitory and excitatory intracortical circuits across the human sleep-wake cycle using paired-pulse transcranial magnetic stimulation. | studies using single-pulse transcranial magnetic stimulation (tms) have shown that excitability of the corticospinal system is systematically reduced in natural human sleep as compared to wakefulness with significant differences between sleep stages. however, the underlying excitatory and inhibitory interactions on the corticospinal system across the sleep-wake cycle are poorly understood. here, we specifically asked whether in the motor cortex short intracortical inhibition (sici) and facilitat ... | 2005 | 15802295 |
| diagnosis and assessment of sleep and circadian rhythm disorders. | sleep and wakefulness are fundamental behavioral and neurobiological states that characterize all higher animals, including human beings. this article presents an overview of the current state of our knowledge concerning the function of sleep and sleep-wake rhythms, the neurobiology of circadian rhythms, how wakefulness and sleep are studied, and the clinical assessment and diagnosis of sleep and circadian rhythm disorders. major theories of the function of sleep and sleep-wake rhythms are revie ... | 2005 | 15803045 |
| the role of neural synchronization in the emergence of cognition across the wake-sleep cycle. | searching for the neural code underlying consciousness and cognition is one of the most important activities in contemporary neuroscience. research with neuronal oscillations at the level of single-neuron, local cell assemblies, and network system have provided invaluable insights into different mechanisms of synaptic interactions involved in the emergence of cognitive acts. a cognitive neuroscience of conscious experience is gradually emerging from behavioral and neuroimaging studies, which can ... | 2005 | 15810655 |
| genetic screens for clock mutants in drosophila. | the isolation and analysis of mutant flies (drosophila melanogaster) with altered circadian rhythms have led to an understanding of circadian rhythms at the molecular level. this molecular mechanism elucidated in fruit flies is similar to the mechanism of the human circadian clock, which confers 24-h rhythmicity to our sleep/wake behavior, as well as to many other aspects of our cellular and organismal physiology. in fruit flies, genes can be mutated to abolish circadian rhythms (i.e., produce a ... | 2005 | 15817286 |
| i'm a 72-year-old man, and i often wake up four or five times a night to urinate. why is this? | | 2005 | 15818789 |
| high frequency activities in the human orbitofrontal cortex in sleep-wake cycle. | we recorded human orbitofrontal electrocorticogram during wakefulness and sleep in epileptic patients using subdural electrodes. during wakefulness and rapid eye movement (rem) sleep, we observed beta activity in the raw orbitofrontal signals. power spectral analysis demonstrated beta enhancement during wakefulness and rem sleep when compared to slow wave sleep (sws). during the phasic rem periods, the beta power was significantly lower than during the tonic rem periods. gamma enhancement manife ... | 2005 | 15823426 |
| computational simulation of human upper airway collapse using a pressure-/state-dependent model of genioglossal muscle contraction under laminar flow conditions. | a three-element, pressure- and state (sleep and wake) -dependent contraction model of the genioglossal muscle was developed based on the microstructure of skeletal muscle and the cross-bridge theory. this model establishes a direct connection between the contractile forces generated in muscle fibers and the measured electromyogram signals during various upper airway conditions. this effectively avoids the difficulty of determining muscle shortening velocity during complex pharyngeal conditions w ... | 2005 | 15831800 |
| pre-marital hiv testing in couples from faith-based organisations: experience in port harcourt, nigeria. | this descriptive cross-sectional study was conducted among prospective couples referred from faith-based organisations in port harcourt, nigeria for pre-marital hiv screening. the study sought to establish the sero-prevalence of human immunodeficiency virus (hiv) in this peculiar study group. | 2005 | 15832641 |
| bilateral paramedian midbrain infarct: an uncommon variant of the "top of the basilar" syndrome. | occlusion of the rostral portion of the basilar artery can result in ischaemia of the midbrain and thalami, as well as of the temporal and occipital lobes. the so called "top of the basilar" syndrome manifests clinically as numerous combinations of abnormalities of alertness, sleep-wake cycle, and behaviour and oculomotor or pupillomotor functions. a 67 year old man presented with bilateral internuclear ophthalmoplegia, rubral tremor, and daytime somnolence. he was awake during the night and mos ... | 2005 | 15834041 |
| intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans. | the internal circadian clock and sleep-wake homeostasis regulate the timing of human brain function, physiology, and behavior so that wakefulness and its associated functions are optimal during the solar day and that sleep and its related functions are optimal at night. the maintenance of a normal phase relationship between the internal circadian clock, sleep-wake homeostasis, and the light-dark cycle is crucial for optimal neurobehavioral and physiological function. here, the authors show that ... | 2005 | 15834113 |
| an e-health solution for automatic sleep classification according to rechtschaffen and kales: validation study of the somnolyzer 24 x 7 utilizing the siesta database. | to date, the only standard for the classification of sleep-eeg recordings that has found worldwide acceptance are the rules published in 1968 by rechtschaffen and kales. even though several attempts have been made to automate the classification process, so far no method has been published that has proven its validity in a study including a sufficiently large number of controls and patients of all adult age ranges. the present paper describes the development and optimization of an automatic class ... | 2005 | 15838184 |
| sleep laboratory study on single and repeated dose effects of paroxetine, alprazolam and their combination in healthy young volunteers. | to evaluate the potential interaction of 20 mg paroxetine and 1 mg alprazolam (early morning once-daily administration) on polysomnographic (psg) sleep and subjective sleep and awakening quality, both after a single intake and after reaching a steady-state concentration. | 2005 | 15838185 |
| sleep-wake states in transgenic mouse models overexpressing the human beta-amyloid precursor protein. | studies testing the amyloid hypothesis and recent advances in mouse molecular genetic technologies have played a critical role in improving our understanding of alzheimer's disease (ad). mouse models of ad currently available show only some of the characteristic neuropathology in human ad. studies have demonstrated, however, that these models are excellent tools for characterizing different aspects of the molecular pathology of ad and the neurobiological basis for the clinical heterogeneity in a ... | 2005 | 15844754 |
| influenza. test kit error is wake-up call for 50-year-old foe. | | 2005 | 15845807 |
| [severe hyponatremia during transurethral resection of prostate]. | we report a case of severe hyponatremia (na 82 meq x l(-1)) during transurethral resection of the prostate for benign prostatic hypertrophy. a 61-year-old man was managed with epidural anesthesia and intravenous propofol. three percent sorbitol (uromatic s) solution was used for irrigation fluid. the serum sodium level 1 and 3 hours after the start of operation was 103 meq x l(-1) and 82 meq x l(-1), respectively. one hour after cessation of propofol administration he did not wake up, although h ... | 2005 | 15852630 |
| propagation of surface fatigue cracks in human cortical bone. | an understanding of how fatigue cracks grow in bone is of importance as fatigue is thought to be the main cause of clinical stress fractures. this study presents new results on the fatigue-crack growth behavior of small surface cracks (approximately 75-1000 microm in size) in human cortical bone, and compares their growth rates with data from other published studies on the behavior of both surface cracks and many millimeter, through-thickness large cracks. results are obtained with a cyclically ... | 2006 | 15907859 |
| valerian extract and valerenic acid are partial agonists of the 5-ht5a receptor in vitro. | insomnia is the most frequently encountered sleep complaint worldwide. while many prescription drugs are used to treat insomnia, extracts of valerian (valeriana officinalis l., valerianaceae) are also used for the treatment of insomnia and restlessness. to determine novel mechanisms of action, radioligand binding studies were performed with valerian extracts (100% methanol, 50% methanol, dichloromethane [dcm], and petroleum ether [pe]) at the melatonin, glutamate, and gaba(a) receptors, and 8 se ... | 2005 | 15921820 |
| circadian rhythms, sleep, and performance in space. | maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the national aeronautics and space administration's (nasa's) vision "to extend humanity's reach to the moon, mars and beyond" to become a reality. field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. this paper documents evidence of significant sleep ... | 2005 | 15943202 |
| identification of novel clock-controlled genes by cdna macroarray analysis in chlamydomonas reinhardtii. | circadian rhythms are self-sustaining oscillations whose period length under constant conditions is about 24 h. circadian rhythms are widespread and involve functions as diverse as human sleep-wake cycles and cyanobacterial nitrogen fixation. in spite of a long research history, knowledge about clock-controlled genes is limited in chlamydomonas reinhardtii. using a cdna macroarray containing 10 368 nuclear-encoded genes, we examined global circadian regulation of transcription in chlamydomonas. ... | 2005 | 15952072 |