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Biomedical subjects

K M Stevens

Publications and source records attributed to K M Stevens.

16 recordsLinked to original sources
PubMed1992

My room--not theirs! A case study of music during childbirth.

The more holistic goals of midwifery are emphasised in this paper through the therapeutic application of music. Material resulting from an interview with a mother after the birth of her first child is used to demonstrate many of the psychological and socio-psychological benefits of listening to music during labour. Several of these benefits were experienced not only by the mother-to-be but also by her partner and the hospital staff. In the outlining of numerous advantages for employing music listening in birthing situations--in particular, comfort and security, self-esteem, socialisation and personal control--the importance of music as a nursing intervention is stressed.

Female↗
PubMed1981

Pain: evolutionary background and primary stimulus.

The evolution of aerobic organisms required the development of oxygen sensors so the organism could avoid anoxic environments. In man these oxygen sensors are known as pain receptors. The skin pain receptor includes the epidermis and the dermal papilla with its capillary and terminal nerve. A pain stimulus such as a pin prick occludes blood flow into the papilla. The epidermal cells consume enough residual oxygen to produce a fall in oxygen tension at the nerve ending sufficient to cause the nerve to fire. The maximum time required for the oxygen drop is 0.04 seconds.

Animals↗
PubMed1981

Agent Orange toxicity: a quantitative perspective.

1 The minimum toxic dose of tetrachloro-dibenzo-p-dioxin (TCDD) for man has been calculated from monkey and human data to be 0.1 microgram kg-1. 2 The amount of TCDD which man takes in from his environment is about 1/2050 of that present in one square metre of his immediate environment. 3 The average concentration of TCDD present in Vietnam immediately after spraying Agent Orange was 8 microgram m-2. 4 A soldier directly sprayed would attain an internal body concentration of 7 X 10(-5) microgram kg-1 or 1/1750 of the minimum toxic dose; soldiers moving through previously sprayed areas would ingest much less. 5 These quantitative aspects indicate that the dioxin sprayed with Agent Orange in Vietnam cannot have caused systemic illnesses in Vietnam veterans or birth defects in their children.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1979

Cultivation requirements for Treponema pallidum, Mycobacterium leprae and other microbial and mammalian microaerophilic cells.

Atmospheric and biological evolution progressed simultaneously and today certain cell types flourish only at oxygen tensions which were ambient 600 million years ago, i.e., at 5 to 10 mm Hg. In man, a continuous oxygen flow at these pressures is supplied in the skin where Treponema pallidum, Mycobacterium leprae and members of the genus Rickettsia grow best. In vitro studies support the microaerophilic status of these organisms and of certain other microbial and mammalian cells. Vigorous growth in pure culture will await the development of techniques which can maintain these low oxygen tensions at the cell walls of the microbes as they replicate and consume increasing amounts of oxygen. Continuing failure to consistently isolate microbes from active lesions in patients with rheumatoid arthritis or systemic lupus erythematosus may reflect the universal absence of suitable methods for isolation of microaerophilic microbes.

Anaerobiosis↗
PubMed1979

Anoxemia as the cause of death in shock.

The case is presented that both hemorrhagic and septic shock are due to an inadequate oxygen supply to mitochondria of vascular muscle cells in peripheral circulatory beds. Mitochondria disintegrate in the presence of severe hypoxia; this is a normal response which does not, per se, indicate generalized cell damage. Irreversible shock follows when appreciable numbers of the muscle mitochondria become non-functional. The ATP available from glycolysis is inadequate to resynthesize the mitochondrial apparatus and oxygen cannot be used by the damaged mitochondria to produce the needed ATP through oxidative phosphorylation. In the absence of adequate ATP, the tone of these peripheral vessels must fall, leading to irreversible systemic hypotension and death. In hemorrhagic shock, mitochondrial hypoxia of smooth muscle cells is produced by decreased perfusion of the vasa vasorum in the constricted peripheral vessels; in septic shock there is direct competition for oxygen between bacterial cytochromes and muscle mitochondria.

Adenosine Triphosphate↗