Martin Moore-Ede - Academia.edu (original) (raw)

Papers by Martin Moore-Ede

원자력산업 = Nuclear industry, 1987

Clinical Pharmacology & Therapeutics, May 1, 1973

Extensive hone demineralization and hypercalciuria occur in paraplegie patients during the first ... more Extensive hone demineralization and hypercalciuria occur in paraplegie patients during the first few months of immohilization. During this time, urinary calcium excretion has heen shown to have a circadian rhythm with a maximal excretion at midday. Oxymetholone (Anapolon, Anadrol) timed to cover the period of maximum calcium loss resulted in a flattened urinary calcium rhythm and reduction in the 24 hOUT calcium excretion in 2 of 4 paraplegie suhiects. The efJectiveness of a single 10 mg dose given at various times of day was then compared in 29 acute paraplegie patients. Ten milligrams of oxymetholone given at 6 AM, hefore the peak in calcium excretion, produced a significant fall in the 24 hour calcium excretion, hut similar doses at other times of day were inefJective. The findings are consistent with known circadian rhythms of hone metaholism and provide another example of a circadian rhythm in drug efJectiveness.

Brain Research, Sep 1, 1983

In vivo glucose utilization was measured in the suprachiasmatic nuclei (SCN) of the rat, monkey, ... more In vivo glucose utilization was measured in the suprachiasmatic nuclei (SCN) of the rat, monkey, and cat using the 14C-labeled deoxyglucose technique. SCN metabolic activity in all species was endogenously rhythmic with high levels during the subjective daylight portion of the 24 h day. Such phase conservation across night-, day-, and randomly-active species is in agreement with formal analyses of the properties of entrainable circadian oscillators, and our data suggest that the biochemical processes which underlie the activity of this circadian clock are similar in mammals with differing patterns of expressed circadian rhythmicity.

Transactions of the American Nuclear Society, 1987

American Journal of Physiology-regulatory Integrative and Comparative Physiology, May 1, 1986

Biological Psychiatry, Jul 1, 1990

Lithium lengthens the period of free-running circadian rhythms in a variety of species, but this ... more Lithium lengthens the period of free-running circadian rhythms in a variety of species, but this effect has not been demonstrated unequivocally in primates. Because of the possible link between lithium's action on the circadian clock and its therapeutic action in human mood disorders, we tested the ability of lithium to lengthen circadian period in a diurnal primate with circadian properties similar to those of humans. Lithium carbonate was administered in food pellets to 8 adult male squirrel monkeys (S~Jti sciureus) for at least 27 consecutive days. Serum lithium levels on the last day of lithium administration ranged from 0.76 to 2.02 mEqlliter, comparable to the therapeutic range for treatment of bipolar disorder in humans (0.6-1.2 mEqlliter). Circadian periods of perch-hopping activi~, were longer during lithi,.~m treatment than during baseline in 7 of the 8 monkeys (chat~ges of-0.08 to + 1.41 hr, mean +0.55 hr, p = 0.01), and returned toward baseline values when lithium was discontinued. In most cases, the period change was evident within a few days after beginning full lithium dose, and was not accompanied by changes in level or pattern of activity, nor in amplitude of the circadian rhythm. Food consumption and body weight were reduced during lithi¢¢m treatment, and rebounded on return to lithium-free diet. Period change was related to lithium dose (p < 0.05), but did not correlate with food consumption, body weight, or baseline circadian period. These results, by establishing that lithium lengthens circadian period in primates, suggest that studying the cellular mechanisms of this circadian effect may be relevant to understanding lithium's therapeutic effect on mood in humans.

Journal of Occupational and Environmental Medicine, Feb 1, 2012

• An FRMS is analogous to (or a subset of) a safety management system (SMS). • An FRMS is science... more • An FRMS is analogous to (or a subset of) a safety management system (SMS). • An FRMS is science based, data driven, and subject to continuous improvement; in short, it is a system to manage risk associated with fatigue. • Fatigue risk management systems are designed to improve outcomes and are more flexible than duty-rest and hours-ofservice regulations.

The New England Journal of Medicine, Sep 25, 1980

American Journal of Physiology-regulatory Integrative and Comparative Physiology, Dec 1, 1983

The temporal organization of physiological events within an animal may often be as important as t... more The temporal organization of physiological events within an animal may often be as important as their spatial organization. Mutually interdependent events must not only occur at precise spatial locations but must also occur with appropriate timing. Similarly, incompatible processes, which may require different physicochemical conditions for their completion, can be separated just as effectively in time as in space. This chapter first examines the normal temporal order of biochemical, physiological, and behavioral events over the course of the circadian day, looking at animals both entrained to 24-hr environmental time cues and freerunning in constant conditions. Second, the anatomy and physiology of the system that maintains this internal temporal order is discussed. Finally, we consider the advantages of maintaining a cyclic environment and the consequences of disturbing internal synchrony. INTERNAL TEMPORAL ORDER IN STEADy-STATE-ENTRAINED CONDITIONS When animals are maintained in an environment with a strong zeitgeber, such as a 24-hr light-dark cycle, each circadian rhythm in the organism assumes a stable relationship with that zeitgeber. An obvious consequence is that the various circadian rhythms within the organism assume stable phase relationships with each other. In this section, we discuss the structure of the entrained system.

Comparative Biochemistry and Physiology Part A: Physiology, 1979

Squirrel monkeys display a prominent circadian rhythm in body temperature (r,). When entrained to... more Squirrel monkeys display a prominent circadian rhythm in body temperature (r,). When entrained to 24-hr light-dark (LD) cycles, T,, is defended against mild 6-hr cold exposures at all circadian phases. In constant light (LL), however. the animals' ability to defend T,, against similar cold exposures is impaired. 2. We have examined the potential roles of internal circadian synchronization and other factors such as LL or chair-restraint in determining the animals' ability to thermoregulate in the cold. 3. Constant light andjor chair-restraint were ruled out as being major contributions to this tbermoregulatory response in experiments where an alternate circadian synchronizer (24-hr cycles of food availability) was supplied to animals in Lt. These animals were able to maintain T,, at the same levels as comparable controls when they were cold exposed at three different circadian phases. 4. The role of internal circadian synchronization was examined using an adrenalectomized squirrel monkey preparation. These animals, when supplied with replacement cortisol at 24-hr intervals, have the same circadian thermoregulatory characteristics as intact control animals, and when synchronized by LD cycles can maintain T,, during cold exposure. 5. In LL. the adrenalectomized animals, with 24-hr cortisol replacement, become internally desynchronized since a portion of the circadian system is entrained by cortisol and the rest free-runs. In this state, the cold exposures produce significant decreases in T,,. 6, The data indicate that for effective thermoregulation to occur, proper temporal synchronization of the circadian timekeeping system of the squirrel monkey is essential.

PubMed, 2022

Light exposure at night can disrupt the circadian timing of cellular processes and is associated ... more Light exposure at night can disrupt the circadian timing of cellular processes and is associated with a broad range of health disorders. To spectrally engineer lighting which minimizes circadian disruption at night it is necessary to define the precise spectral sensitivity of the human circadian system. Prior attempts have used short monochromatic light exposures in dark-adapted human subjects, or in vitro dark-adapted isolated retina or melanopsin. However, humans spend virtually all their awake hours in a fully light-adapted state. Here we review the evidence for a narrow blue circadian sensitivity curve for light-adapted humans derived from experiments using spectral filtering of light sources, and comparisons of light sources with diverse spectral power distributions. This light-adapted Circadian Potency function permits the development of circadian-protective light for nocturnal use and circadian-entraining light for daytime use.

Physiology & Behavior, Apr 1, 1985

Role of heat loss and heat production in generation of the circadian temperature rhythm of the sq... more Role of heat loss and heat production in generation of the circadian temperature rhythm of the squirrel monkey. PHYSIOL BEHAV 34(4) 543-546, 1985.-To study heat production and heat loss in determination of the daily body temperature rhythm, we examined colonic temperature, skin (tail, foot and abdomen) temperatures and oxygen consumption in chair-restrained squirrel monkeys maintained in isolation in an environmental chamber with a 24-hr light-dark cycle (LD 12:12), maintained at a constant thermoneutral temperature (26°C). In all experiments repeated high amplitude (2°C) diurnal rhythms in colonic temperature were observed. Heat loss, estimated from changes in skin temperature, also displayed a circadian rhythm, although there was considerable variation in waveform. On average, a rhythm in heat production, indicated by changes in the rate of oxygen consumption, was also present. However, a large degree of variability was seen in oxygen consumption, and in several cycles from various animals there were no observable 24-hr rhythms. The circadian body temperature rhythm is thus not simply a consequence of daily changes in metabolism, but rather a regulated response that involves both heat production and heat loss.

Physiology & Behavior, May 1, 1977

Feeding time synchronizes primate circadian rhythms. PHYSIOL. BEHAV. 18(5) 775-779, 1977.-Circadi... more Feeding time synchronizes primate circadian rhythms. PHYSIOL. BEHAV. 18(5) 775-779, 1977.-Circadian rhythms of squirrel monkeys maintained in constant light and temperature can be entrained by 24 hr cycles of food availability with eating for 3 hr and fasting for 21 hr (El. 3:21). Rhythms of drinking, body temperature and urinary potassium and water excretion exhibited periods which matched the 24 hr period of the EF 3:21 cycle. These results suggest that temporal patterns of food intake are capable of synchronizing the circadian timekeeping system which underlies the observed rhythms. Circadian rhythms Synchronization Zeitgebers Primates Squirrel monkeys Feeding time Body temperature Urinary electrolytes

American Journal of Physiology-regulatory Integrative and Comparative Physiology, 1982

Human subjects during extended isolation from environmental time cues show complex variations in ... more Human subjects during extended isolation from environmental time cues show complex variations in timing and duration of sleep with a progressive pattern, which eventually results in rest-activity and body temperature rhythms having different average periods. We present a model where temperature and rest-activity are each governed by an oscillator of the van der Pol type, denoted x and y, respectively. The oscillators affect one another through "velocity" type coupling, the effect of x on y being about four times greater than y on x. Periodic zeitgeber, z, is modeled as forcing only on y. We find that the entire pattern sequence can be realistically reproduced by causing only the intrinsic period of the y oscillator to increase while that of x remains stable. Desynchronization between x and y is the result of the intrinsic periods of the two oscillators becoming so disparate that the coupling is no longer able to enforce synchrony. Prior to desynchronization both human subjects and our model exhibit "phase trapping" wherein the relative phase of x and y is slowly modulated although the average x and y periods match. The model phase relations between temperature and both the timing and duration of sleep are, throughout, in good agreement with entrained and free-running human data. Most importantly, the model shows that the dramatic change in the length of the rest-activity cycle when desynchronization occurs is actually due to a relatively small variation in the governing variable, y.

Science, Jul 30, 1982

logical systems. Osmotic swelling of cytoplasmic vesicles could, in principle, occur through a nu... more logical systems. Osmotic swelling of cytoplasmic vesicles could, in principle, occur through a number of mechanisms, including mobilization of osmotically inactive constituents in the vesicle, alteration of vesicle membrane permeability to ions, or stimulation of ion pumping into the vesicles. In the experiment represented in Fig. iB, osmotic swelling of the vesicle was accomplished by substituting a permeant solute (glucose) for a nonpermeant one (stachyose). This is formally equivalent to a biological vesicle osmotically swelling because of an increase in the permeability of its membrane to cytosolic constituents, such as ions. Numerous examples already exist of vesicle swelling being associated with exocytosis (although it is not yet clear that the swelling precedes fusion). Among these are mucocyst discharge in Tetrahymena (13), serotonin release by mast cell granules (14), and granular discharge by Limulus amoebocytes (15). It has also been shown that antidiuretic hormone-stimulated fusion of cytoplasmic tubular vesicles with the luminal plasma membrane of toad urinary bladder can be regulated by osmotic forces in a manner consistent with that of vesicleplanar membrane fusion (16). Although in our system Ca2+ stimulates fusion by promoting the close association of vesicle and planar membranes, this need not be its role (or its only role) in biological exocytosis. The possibility that increased levels of Ca2' trigger fusion by stimulating osmotic swelling of vesicles (by any of the mechanisms mentioned above) merits serious consideration.