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Biomedical subjects

W Nelson

Publications and source records attributed to W Nelson.

17 recordsLinked to original sources
PubMed1979

Rhythmometry gauges treatment of mesor-hypertension in the seventh and eight decades of life.

Autorhythmometry of blood pressure by an individual over an age-span of 67 to 72 years showed a strong circadian rhythm superimposed upon significant circaseptan and circannual rhythms. Automatic BP monitoring with an Arteriosonde throughout 24-hour spans on 4 separate occasions, before and during treatment, also indicated a prominent circadian BP rhythm and a treatment-related reduction in circadian mesor. The concept of a blood pressure mesor reference for the antimesor-hypertensive treatment constitutes a valuable guideline in the control of "familial" mesor-hypertension.

Aged↗
PubMed1978

Time-qualified reference intervals - chronodesms.

Methods are presented for qualifying clinical reference intervals, for individuals as well as peer groups, according to circadian and other rhythms, using chronobiologically-defined single samples or time series.

Biological Clocks↗
PubMed1978

Chronobiologic optimization of aging.

Chronobiologic facts, concepts and methods are relevant to gerontology and geriatrics. Circadian and other rhythms are prominent sources of predictable variation requiring a reassessment of the "normal range" at all ages. Changes in the characteristics (e.g., the amplitude) of these rhythms during aging emphasize the need for careful evaluation of time dependency in research and clinical practice. Manipulation of periodic environmental factors that synchronize circadian rhythms can affect lifespans in plants and animals, further supporting the suggestion of an interaction between rhythms and senescence.

Aged↗
PubMed1978

Delayed hypersensitivity to retrobulbar injections of methylprednisolone acetate.

A patient with chronic cyclitis developed hyperemia of the episcleral and bulbar conjunctival vessels after retrobulbar injections of methylprednisolone acetate suspension. Intradermal testing revealed the responsible allergen to be methylprednisolone acetate; hypersensitivity could not be demonstrated by patch testing, despite use of increased concentrations.

Adult↗
PubMed1977

Evolutionary changes in the electrocardiogram of severe progressive hypothermia.

A patient is reported who developed progressive hypothermia during therapy for adult respiratory distress syndrome. Electrocardiographic changes (sinus bradycardia, prolonged PR interval, prolonged QTc interval, "Osborn waves") were documented and correlated with body temperature. The significance of these changes is discussed and the relationship between the degree of hypothermia and the presence of "Osborn waves" is noted.

Adult↗
PubMed1976

Use of disposable Velcro sleeves on gastrointestinal clamps and forceps.

Observed need for an atraumatic manner of holding and occluding stomach and intestine led to the development of a Velcro sleeve applied to various modified gastrointestinal clamps and forceps. The sleeve was found to hold more securely with minimal coaptation than previously used instruments, and to hold more atraumatically with heavy coaptation.

Digestive System Surgical Procedures↗
PubMed1976

Cost-benefit analysis of fluoridation in Houston, Texas.

Most previous cost-benefit analyses of fluoridation programs have been retrospective in approach and have biased their results in favor of fluoridation. This study performed a prospective cost-benefit analysis of fluoridating a segment of the water supply for Houston, Texas, and explicitly introduced and evaluated the time pattern of the costs and benefits. It was shown that neglect of the time structure of the costs and benefits would significantly bias the results. A benefit-cost ratio of 1.51 and a net present value (or "social profit") of $1,102,970 were found. The results are biased downwards and should be considered a lower bound. Thus the results indicate an investment in a fluoridation program by Houston would be a socially profitable one.

Adolescent↗
PubMed1975

Circadian rhythms in mice fed a single daily meal at different stages of lighting regimen.

Circadian rhythms in systemic and cellular variables were studied in three groups of mice on different schedules of daily food accessibility: (1) only during the first 4 hours of the 12-hour light span; (2) only during the first 4 hours of the 12-hour dark span; and (3) at all times. The amplitudes of circadian variation in rectal temperature, serum corticosterone, and liver glycogen were increased by "meal-feeding" in either early light or early darkness. The overall averages of corticosterone and glycogen were also increased by meal-feeding at either stage of the lighting regimen. The time of peak values in temperature, corticosterone, and glycogen were determined by the time of food presentation, regardless of its relation to the lighting regimen. On the other hand, the interval between food presentation and peak values in the corneal mitotic index was greater when feeding was restricted to early darkness. These differences among the three groups of animals resulted in different relations among varibles at any given interval after feeding onset. Such effects concerning total bodily function, energy storage, hormonal regulation, and basic cellular processes indicate the pertinence of meal timing to nutritional research and practice.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Chronochemotherapy: L 1210 leukemia and beyond.

In cancer and other therapeutic research, an interpretation of median survival times can and should take cure into account. With this qualification, an analysis of recently published data provides further statistically significant evidence in favor of cancer chronotherapy as compared to homeostatic therapy.

Animals↗
PubMedDate not supplied

Strain-difference in circadian murine chronotolerance to the antidepressant drug nomifensine.

The anti-depressant drug nomifensine (8-amino-1,2,3,4-tetrahydro-methyl-4-phenylisoquinoline) was administered at several dose levels to mice of 2 inbred strains at one of 6 circadian times 4h apart under conditions standardized for light-dark synchronized rhythmometry. A circadian rhythm in tolerance to nomifensine reflected by differences in mortality was demonstrated for both C57 and DBA mice. An interstrain difference in tolerance was also observed.

Animals↗
PubMedDate not supplied

Higher corticosterone values at a fixed single timepoint in serum from mice "trained" by prior handling.

Results of "training" rodents for bioassay of synthetic corticosteroids are not consistent with expectations presumably based upon earlier implied claims stemming, perhaps, from over behavioral patterns displayed by handled as compared to nonhandled rodents (or the observer's wishful thinking?). At the timepoints investigated, "habituation" of mature mice and rats by exposure to handling, injection and killing procedures results in statistically significantly increased corticosterone concentrations. For younger animals the elevation in corticosterone concentration may also be applicable; although, it is not known to what extent we are dealing with an effect of "habituation" and/or age. Lowest hormone concentration occurred in the groups of mice housed undisturbed in an animal chamber separate from the room housing mice subjected to habituation. The results of this study suggest that for certain rodents kept in L from 0600 to 1800 "habituation" for 1 week, at least at the circadian stage corresponding to 0800, is not only ineffectual (in eliminating the rise in serum corticosterone associated with handling) but detrimental to the evaluation of synthetic corticosteroid potency by bioassay (to the extent that such a rise in exaggerated rather than reduced). In these acute experiments, methylprednisolone was more suppressive than dexamethasone and the water soluble ester-salts less suppressive than the 21-hydroxy bases. These results suggest the possibility of important differences in the distributive stage and/or the metabolism of these compounds--factors affecting the speed of onset of the desired as well as undesired effects.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Competing circadian effects of methylprednisolone and rat weight, light chains, immunocytoma size and survival.

Eighty-four singly housed LOU rats, 43 males and 41 females, were studied (under conditions standardized for rhythmometry) for the effect of methylprednisolone sodium succinate (MP) upon a transplantable immunocytoma. Body temperature was monitored as a host reference rhythm while light chain excretion and tumor size were monitored to determine an effect upon the tumor. The MP, dissolved in a sweet solution, was consumed by the rats without any statistically significant shift in acrophase of the circadian temperature rhythm. Time dependent effects of MP treatment were observed with respect to 1) tumor size decrement and 2) the survival of treated animals, as compared to untreated animals.

Animals↗