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Biomedical subjects

S Glaser

Publications and source records attributed to S Glaser.

At least 55 records · Page 3Linked to original sources
PubMed1988

Evidence of a previously undescribed form of respiratory sinus arrhythmia (RSA)--the physiological manifestation of "cardiac aliasing".

Within the fluctuations that occur in heart rate, there is a major component known as respiratory sinus arrhythmia (RSA), which up to now has been defined as heart rate variability which is synchronous with respiratory movements. We have now discovered that RSA synchronous to respiratory movements is only one example of RSA. If a special relationship exists between mean heart rate (fHR) and mean frequency of breathing (fB) such that fB greater than 1/2 fHR, RSA can be observed in a frequency range which is lower than the frequency of breathing. The mathematical fundamentals of this physiological phenomenon are the same as those for the "aliasing"-effect in signal sampling. Therefore, we have called this phenomenon "cardiac aliasing". We have been able to experimentally demonstrate this, up to now unknown, phenomenon in adult rabbits and dogs as well as in human neonates.

Animals↗
PubMed1988

Communication.

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Communication↗
PubMed1987

[Neuroautonomic organization of cardiac rhythm and of nonrhythmic oscillations in the frequency of cardiac contractions and respiration].

In 25 chronic adult rabbits, the functional organization of neurally mediated short-term rhythms and patterns of the heart rate (HR) were investigated. The respiration-unrelated arrhythmia seems to be vagally mediated only, being abolished with atropine. The respiration-related arrhythmia exists not only within the range of respiratory frequency but also in lower frequencies as discovered by spectral and coherence analysis. During motor activity, there is a systematic correlation among increasing premotor, motor and amygdaloid multispike activities, increasing HR and depressed HR-rhythms with limbic initiation of motor and concomitant autonomic patterns, "Immobile confrontations" alone produces vagally induced HR-decrease and increased amplitudes of vagal HR-rhythms with a concomitant cortical multispike depression, a mirror image of the autonomic patterns after nociceptive stimulation.

Action Potentials↗
PubMed1984

Statistical association between cancer incidence and major-cause mortality, and estimated residential exposure to air emissions from petroleum and chemical plants.

An ecologic study design was used to investigate the relationship between exposure to air emissions produced by the petroleum and chemical industries, and average annual cancer incidence and major cause mortality rates among whites in Contra Costa County, California. Estimates for the exposure to major industrial sources of sulfur dioxide, hydrocarbons and oxides of nitrogen were used to subdivide the county by level of exposure to petroleum refinery and chemical plant emissions. Cancer incidence and major cause mortality rates were then calculated for whites in each of the exposure areas. In both males and females, residential exposure to petroleum and chemical air emissions was associated with an increased incidence of cancer of the buccal cavity and pharynx. In males, age-adjusted incidence rates for cancers of the stomach, lung, prostate and kidney and urinary organs were also associated with petroleum and chemical plant air emission exposures. In both sexes, we found a strong positive association between degree of residential exposure and death rates from cardiovascular disease and cancer, and a less strong positive association between exposure and death rates from cerebrovascular disease. There was also a positive association in men for deaths from cirrhosis of the liver. Although these observed associations occurred across areas of similar socioeconomic and broad occupational class, confounding variables and the "ecologic fallacy" must be considered as possible explanations. In particular, the stronger findings in men suggest an occupational explanation of the cancer incidence trends, and the effect observed in cirrhosis mortality suggests that lifestyle variables such as alcohol consumption were not adequately controlled for. While the public health implications of our findings remain unclear, the evidence presented is sufficient to warrant follow-up studies based on individual data in which possible biases can be more readily controlled.

Air Pollutants↗
PubMed1980

Ozone toxicity symptoms among flight attendants.

Because of persistent complaints of ozone-toxicity type symptoms among crew members of commercial airlines, we undertook a survey to determine the extent of the problem and the associated flight factors. Self-reported questionnaires and flight diaries were completed by 1,330 flight attendants, (FAs) working for three different airlines. Ozone-toxicity type symptoms were reported three or four times more frequently by FAs with airlines flying at high altitudes than by those with low-flying airlines. When examined by characteristics of flights, the ozone-toxicity type symptoms were significantly associated with flight altitude, duration and type of aircraft, but not with years worked, sex, medical history, or home residence. Other symptoms indicative of fatigue or stress were mainly associated with flight duration. While these indirect data cannot implicate ozone specifically, they offer evidence that ozone-related health problems do exist among a large proportion of FAs.

Adult↗
PubMed1975

[Not Available].

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Global Health↗