Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement

The period of the year from spring to fall, when clocks in most parts of the United States are set one hour ahead of standard time, is called daylight saving time, and its beginning and ending dates and times are set by federal law. The human biological clock is regulated by the timing of light and darkness, which then dictates sleep and wake rhythms. In daily life, the timing of exposure to light is generally linked to the social clock. When the solar clock is misaligned with the social clock, desynchronization occurs between the internal circadian rhythm and the social clock. The yearly change between standard time and daylight saving time introduces this misalignment, which has been associated with risks to physical and mental health and safety, as well as risks to public health. In 2020, the American Academy of Sleep Medicine (AASM) published a position statement advocating for the elimination of seasonal time changes, suggesting that evidence best supports the adoption of year-round standard time. This updated statement cites new evidence and support for permanent standard time. It is the position of the AASM that the United States should eliminate seasonal time changes in favor of permanent standard time, which aligns best with human circadian biology. Evidence supports the distinct benefits of standard time for health and safety, while also underscoring the potential harms that result from seasonal time changes to and from daylight saving time.

CITATION

Rishi MA, Cheng JY, Strang AR, et al. Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2024;20(1):121-125.

Age and weight considerations for the use of continuous positive airway pressure therapy in pediatric populations: an American Academy of Sleep Medicine position statement

This position statement provides guidance for age and weight considerations for using continuous positive airway pressure (CPAP) therapy in pediatric populations. The American Academy of Sleep Medicine (AASM) commissioned a task force of experts in pediatric sleep medicine to review the medical literature and develop a position statement based on a thorough review of these studies and their clinical expertise. The AASM Board of Directors approved the final position statement. It is the position of the AASM that CPAP can be safe and effective for the treatment of obstructive sleep apnea (OSA) for pediatric patients, even in children of younger ages and lower weights, when managed by a clinician with expertise in evaluating and treating pediatric OSA. The clinician must make the ultimate judgment regarding any specific care in light of the individual circumstances presented by the patient, accessible treatment options, patient/parental preference, and resources.

Obstructive sleep apnea devices for out-of-center (OOC) testing: technology evaluation

Guidance is needed to help clinicians decide which out-of-center (OOC) testing devices are appropriate for diagnosing obstructive sleep apnea (OSA). A new classification system that details the type of signals measured by these devices is presented. This proposed system categorizes OOC devices based on measurements of Sleep, Cardiovascular, Oximetry, Position, Effort, and Respiratory (SCOPER) parameters.Criteria for evaluating the devices are also presented, which were generated from chosen pre-test and post-test probabilities. These criteria state that in patients with a high pretest probability of having OSA, the OOC testing device has a positive likelihood ratio (LR+) of 5 or greater coinciding with an in-lab-polysomnography (PSG)-generated apnea hypopnea index (AHI) ≥ 5, and an adequate sensitivity (at least 0.825).Since oximetry is a mandatory signal for scoring AHI using PSG, devices that do not incorporate oximetry were excluded. English peer-reviewed literature on FDA-approved devices utilizing more than 1 signal was reviewed according to the above criteria for 6 questions. These questions specifically addressed the adequacy of different respiratory and effort sensors and combinations thereof to diagnose OSA. In summary, the literature is currently inadequate to state with confidence that a thermistor alone without any effort sensor is adequate to diagnose OSA; if a thermal sensing device is used as the only measure of respiration, 2 effort belts are required as part of the montage and piezoelectric belts are acceptable in this context; nasal pressure can be an adequate measurement of respiration with no effort measure with the caveat that this may be device specific; nasal pressure may be used in combination with either 2 piezoelectric or respiratory inductance plethysmographic (RIP) belts (but not 1 piezoelectric belt); and there is insufficient evidence to state that both nasal pressure and thermistor are required to adequately diagnose OSA. With respect to alternative devices for diagnosing OSA, the data indicate that peripheral arterial tonometry (PAT) devices are adequate for the proposed use; the device based on cardiac signals shows promise, but more study is required as it has not been tested in the home setting; for the device based on end-tidal CO(2) (ETCO(2)), it appears to be adequate for a hospital population; and for devices utilizing acoustic signals, the data are insufficient to determine whether the use of acoustic signals with other signals as a substitute for airflow is adequate to diagnose OSA.Standardized research is needed on OOC devices that report LR+ at the appropriate AHI (≥ 5) and scored according to the recommended definitions, while using appropriate research reporting and methodology to minimize bias.

Stimulus-induced patterns of bioelectric activity in human neocortical tissue recorded by a voltage sensitive dye

Stimulus-induced pattern of bioelectric activity in human neocortical tissue was investigated by use of the voltage sensitive dye RH795 and a fast optical recording system. During control conditions stimulation of layer I evoked activity predominantly in supragranular layers showing a spatial extent of up to 3000 microm along layer III. Stimulation in white matter evoked distinct activity in infragranular layers with a spatial extent of up to 3000 microm measured along layer V. The mean amplitude of optical signals close to the stimulated sites in layer I and white matter determined 25 ms following the stimulus, decreased by 50% at a lateral distance of approximately 900 microm and 1200 microm, respectively. Velocity of spread along the vertical stimulation axis reached 0.24 m/s in the supragranular layers (layers I to III) and then decreased to 0.09 m/s following layer I activation; stimulation of white matter induced a velocity of spread in layer V of 0.38 m/s, which slowed down to 0.12 m/s when passing the lower border of lamina IV. The horizontal velocities of spread determined from the stimulation site to a lateral distance of 500 microm reached 0.26-0.28 m/s and 0.28-0.35 m/s for layer I and white matter stimulation, respectively. At larger distances velocity of spread decreased. Increased excitability (Mg(2+)-free solution) had no significant effect on the spatio-temporal distribution of evoked activity as compared with control conditions. There were also no obvious differences between the results obtained in slices, which generated spontaneously sharp waves and those which were not spontaneously active. About 30% of the slices (n=7) displayed a greatly different response pattern, which seemed not to be related in a simple way to the stimulation as was the case in the majority of the investigated slices. The activity pattern of those slices appeared atypical in regard to their deviations of the vertical and horizontal extent of activity, to their reduced spatial extent of activity during increased excitability, to their layer-related distribution of activity, and to the appearance of afterdischarges.Concluding, in 30% of the human temporal lobe slices atypical activity pattern occurred which obviously reflect intrinsic epileptiform properties of the resected tissue. The majority of slices showed stereotyped activity pattern without evidence for increased excitability.

Optical monitoring of neuronal activity during spontaneous sharp waves in chronically epileptic human neocortical tissue

Functional changes in neuronal circuitry reflected in spontaneously occurring synchronous sharp field potentials (SSFP) have been reported to occur in human brain suffering from chronic epileptogenicity but not in primary nonepileptic tissue from peritumoral resectates. Voltage sensitive dyes and fast imaging were used to visualize spontaneously occurring rhythmic depolarizations correlated to SSFP in chronically epileptic human neocortical slices obtained during epilepsy surgery. Localized and spatially inhomogeneous neuronal depolarizations were found to underlie spontaneous SSFP, which remained unchanged and spatially restricted to foci <750 micrometer diam even under epileptogenic (low-Mg(2+)) conditions. In cases where ictaform paroxysmal activity occurred in low-Mg(2+) medium, neuronal depolarizations were wide-spread but still spatially inhomogeneous, and the events were preferentially initiated at distinct foci. The findings suggest that small neuronal networks are able to establish and maintain synchronous rhythmic and epileptiform activity.

[Economic management estimate of different environmentally-friendly animal husbandry systems]

This contribution compares conventional and ecological animal production systems. This financial analysis considers dairy farming and pig production and takes into account the individual options and aims of the farms. The profitability changing a conventional animal production system to an ecological system depends on many different parameters. A general statement with regard to all farms and farm systems is not possible. In addition to the farmers qualification, the marketing options, the location of the farm, the mode of operation and the financial situation when change to ecological production is envisaged determine prospects for success and profitability.

Microsatellite polymorphisms reveal phylogenetic relationships in primates

We amplified, via PCR, DNA segments from intron 1 of the tyrosine hydroxylase gene (TH01) and intron 40 of the von Willebrand factor gene (VWA) in ten nonhuman primate genera. In humans both introns contain polymorphic microsatellites with tetrameric repeats. Compared to the allelic ranges in human populations relatively short repeat arrays could be detected for the nonhuman primates typed, presumably reflecting an ancient precursor state at both microsatellite loci. Furthermore, our results provide evidence for an association of the average number of repeats present in different primate genera and their divergence time from man. DNA sequencing of VWA orthologues revealed a relatively high variability in the arrangement of repeats in the 5'-repeat arrays, the generation of which could probably be explained by polar mutational events.

[Diphtheria immunity in the German population]

In the years 1991-1993 the diphtheria antitoxin titres of the blood serum of 2404 persons living in germany was determined by means of the ELISA test. Its aim was to to get an idea of the population's protection given by vaccination against diphtheria. It became evident that the average protection given by vaccination against diphtheria was on the decrease as people grew older. Thus only 3.8% of the 2-5-year olds did not have any protection given by vaccination (antitoxin titre < 0.01 IU/ml). The same was true for approximately 25% of the examined persons who were older than 30. Less than 10% of these persons had a thorough protection given by vaccination/(antitoxin titre > 0.1 IU/ml). In the age group of the 51-60-year olds better immunological protection than expected was found, which could be ascribed to the fact that there was a natural immunigation during the last wide-spread diphtheria epidemic in germany in the 'forties. Another aspect of this result could be a better motivation for-diphtheria vaccination in this age group. Furthermore, it was noticed that the average diphtheria antitoxin titres of women in all age groups were below those of men. In view of the great percentage of the adult population which is not sufficiently protected against diphtheria, it appears necessary to provide for more information of this population group to stimulate and motivate them to care for better protection by vaccination.

Suppression of a ligand operated membrane current by the epileptogenic agent pentylenetetrazol in oocytes of Xenopus laevis after injection of rat brain RNA

The effects of the epileptogenic substance pentylenetetrazol (PTZ) on ligand operated membrane channels were studied. For this purpose serotonin (5-HT) sensitive channels were expressed in RNA injected oocytes of Xenopus laevis. With simultaneous application of both substances, the response to 5-HT was reduced and eventually abolished by PTZ with increasing concentrations (5-100 mM). A reduction of the 5-HT response also appeared when PTZ was applied in various intervals (15 and 240 s) before 5-HT. It may be assumed that PTZ produces a component of its epileptogenic effect by acting on ligand operated membrane channels.

Membrane currents elicited by the epileptogenic drug pentylenetetrazole in the native oocyte of Xenopus laevis

The effects of the epileptogenic agent pentylenetetrazole (PTZ) on membrane currents of native oocytes of Xenopus laevis were studied. PTZ elicits a response that consists of two inward currents. The first one is interpreted to be due to a decrease of potassium permeability since: (1) the input resistance is increased; (2) the equilibrium potential is near that of potassium; (3) the current is decreased during administration of potassium channel blocking agents; and (4) the PTZ response can be mimicked by blocking potassium channels without PTZ application. The second one is interpreted to be due to an increase of chloride permeability since: (1) the input resistance is decreased; (2) the equilibrium potential is near that of chloride; and (3) the response is decreased during administration of chloride blocking agents. These findings correspond to some extent with those made in neurons.

Inward currents elicited by stream of fluid during transmitter-induced current oscillations in RNA-injected oocytes of Xenopus laevis

A stream of fluid elicited an inward current in RNA-injected oocytes of Xenopus laevis during transmitter-induced current oscillations (stream evoked inward current, Ii,st). The Ii,st showed the following characteristics: (1) amplitude and duration (half width time) ranged between 10 and 300 nA and 1 and 3 s, respectively. (2) The Ii,st could be evoked only during transmitter-induced current oscillations; with blockade of the oscillations the Ii,st disappeared. (3) The induction of the Ii,st was independent of the composition of the washing fluid.

Absence of HLA class I and class II antigens as well as beta 2-microglobulin from normal and pathological human spermatozoa

Human spermatozoa from 87 donors with normal or pathologic semen specimen were examined for the expression of HLA-class I and class II antigens as well as beta 2-microglobulin (beta 2m) using a panel of monoclonal antibodies in an indirect immunofluorescence test. The results make it very unlikely that HLA-class I and class II molecules as well as beta 2m are expressed on human sperm cells.

Identification and quantitative measurements of biogenic monoamines in the central nervous tissue of some gastropods

Investigations were carried out to determine levels of biogenic monoamines in the central nervous tissue of seven species of terrestrial gastropods (taxonomic family: Helicidae) using high-performance liquid chromatography (HPLC) with electrochemical detection (ELCD). The central nervous tissue of all species examined contained assayable amounts of dopamine (DA) and serotonin (5-HT). Noradrenaline (NA) was occasionally present; adrenaline (A) could not be detected. The central ganglia of two Mediterranean species generally contain 3-4 times more 5-HT relative to DA than the ganglia of the other species which contain amounts of 5-HT only slightly higher than DA.

A comparison of radiographic findings in fusion and nonfusion patients ten or more years following lumbar disc surgery

Ninety-six patients who had undergone disc excision and midline spinal fusion and 36 patients who had had simple disc excision had spinal radiographs made 10 or more years postoperatively. Claw spurs were found most commonly at the L2-3 and L3-4 levels in fusion patients, particularly male laborers. Traction spurs with segmental hypermobility were found more commonly at the L4-5 level in patients whose spines were not fused, particularly women. Total lumbar flexion-extension was greater in nonfusion than in fusion patients, but the L1-3 mobility was greater in those who had undergone fusion, suggesting a compensatory increase in the range of lumbar motion. Segmental mobility at levels of surgery in nonfusion patients was similar in those with good and those with poor clinical results. Disc space narrowing was common at levels of operation, but did not correspond to the clinical result. Pseudarthrosis was demonstrated in 26% of fusion patients, but was of no clinical significance. Although complex radiographic changes follow lumbar disc surgery, with or without failure, it is concluded that the plane radiograph is of little aid in determining the source of postoperative pain. The sole exception is that of acquired spondylolysis, which was found in 2.5% of this group of fusion patients, and was clearly associated with a poor clinical outcome. Symptomatic degenerative disc disease at levels above lumbar spinal fusions appears to be an uncommon clinical problem.

The long-term effects of spinal fusion on the sacroiliac joints and ilium

Ninety-six patients who had lumbar disk excision and primary posterior fusion were studied 10 or more years after their operations. Thirty-seven per cent complained of persistent graft donor site pain. A comparison of fused patients with and without donor site pain and 36 patients who underwent simple disk excision, revealed no differences in the flexion-extension mobility of the sacroiliac joints, or degenerative changes in the sacroiliac joints. Ectopic bone formation at graft donor sites, and cluneal nerve neuromata did not influence the result. Patients with graft donor site pain had significantly greater complaints of persistent low back pain, postoperative leg pain, and lost more time from work. If the graft was taken from the same side as that of preoperative leg pain, persistent complaints were more common. It is concluded that the sacroiliac joints are not adversely affected by lumbar spine fusion, and that persistent donor site pain is more likely part of a total pain complex referred from the lumbar spine. The sacroiliac joints appear to be relatively noncontributory to problems following lumbar disk surgery.

Disc excision and spine fusion in the management of lumbar disc disease. A minimum ten-year followup

Seventy-nine percent of 312 patients who underwent lumbar disc surgery were evaluated at least 10 years postoperatively (mean equal to 13.7 years). Residual back and nerve root symptoms and functional impairment were equally as common among the 143 patients who underwent fusion as they were among the 64 patients who did not. Thirty percent of the patients whose spines were fused and 37.7% of those patients whose spines were not fused were considered long-term failures because of persistent symptoms or the need for reoperation. Thirty-seven percent of the fusion patients had persistent graft donor site symptoms. Examined patients showed a high percentage of residual neurologic defects. An unexplained positive Trendelenburg sign was present in 14.8% of the fusion patients and in 18.2% of the patients whose spines were not fused. Although retrospective studies often have problems of accuracy, this analysis confirms other observations that midline spinal fusion offers few benefits in the management of lumbar disc disease.

Failed lumbar disc surgery requiring second operation. A long-term follow-up study

Forty-five patients who had lumbar disc surgery 10 or more years previously, and had required a second operative procedure, have been evaluated. Failures occurred up to 16 years after the first operation, and were most commonly due to pseudoarthrosis in the patients who underwent spinal fusion initially, and to recurrent disc lesions at the same level as previous surgery in the patients who did not have fusion. The clinical and functional results in the second group of patients who required a second procedure were comparable to those of patients who required only a single procedure. In contrast, patients who had undergone spinal fusion who required a second procedure had significantly worse clinical and functional results, both in comparison to the patients who did not undergo fusion as well as to patients who had had fusion as a single procedure. The only predictable, demonstrable source of failure was acquired spondylolysis. Frequently, repair of pseudoarthrosis did not lead to symptomatic relief. These data suggest that spinal fusion, when it fails, has a significantly worse prognosis than simple disc excision in the management of lumbar disc disease.