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Biomedical subjects

J K French

Publications and source records attributed to J K French.

78 records · Page 5Linked to original sources
PubMed1978

Mechanism of oxyhaemoglobin breakdown on reaction with acetylphenylhydrazine.

The reaction of oxyhaemoglobin and acetylphenylhydrazine, which results in haemoglobin denaturation and precipitation, was found to be influenced by H202 and superoxide (O2-.) generated during the reaction. By analysing the different haemoglobin oxidation products, it was found that by influencing the rate at which oxyhaemoglobin was oxidized, H2O2 accelerated the overall haemoglobin breakdown, and O2-. inhibited it. By adding GSH (reduced glutathione) or ascorbate, it was possible to slow down the rates of both oxyhaemoglobin oxidation and O2-. production, and the overall rate of haemoglobin breakdown. These results are compatible with a mechanism involving production of the acetylphenylhydrazyl free radical, and with GSH, ascorbate and O2-. acting as radical scavengers and preventing its further reactions. The reaction produced choleglobin, as well as acetylphenyldiazine and methaemoglobin, which combined to form a haemichrome. The haemichrome was less stable and precipitated first. It was also less stable than the haemichrome formed by direct reaction of acetylphenyldiazine with methaemoglobin, and it is proposed that this is because the methaemoglobin produced from oxyhaemoglobin and acetylphenylhydrazine was modified by the free radicals and H2O2 produced in the reaction.

Azo Compounds↗
PubMed1977

Haemoglobin--a frustrated oxidase? Implications for red cell metabolism.

The haem proteins can be considered, in one aspect of their function, as machines for activating oxygen. In the case of oxygen-carriers such as haemoglobin, the globin has evolved so that its conformation limits access to the haem group, with resultant reversible release of oxygen. However, distortion of the globin may allow either the discharge of oxygen as the activated product superoxide or, more threateningly, allow direct function of the haemoglobin as an oxidative enzyme. Support for this is shown by the reaction with acetylphenylhydrazine where haemoglobin functions as both an oxidase and oxygenase. An implication of oxidase activity is the potential to initiate free radical formation particularly with unsaturated lipids. Observations of the acetylphenylhydrazine reaction emphasize the role of glutathione as a free radical scavenger.

Ascorbic Acid↗
PubMedDate not supplied

Shattered images: recovery for the SCI client.

Spinal cord injury (SCI) is one of the most traumatic afflictions a person can experience. The impact of the injury on body image often seems unbearable. The SCI individual faces the reality of a known body image that has been replaced by a devastating change in both appearance and function. The physiological and psychological changes created by the SCI require time for adjustment. This article proposes a four-stage process adapted from Grunbaum (1985) to help SCI clients recover from a disturbance in body image. Nursing interventions for the SCI client that facilitate restoration of a shattered body image are suggested.

Body Image↗
PubMedDate not supplied

Occluded infarct-related arteries and clinical events.

Late patency of the infarct-related artery has been shown to be associated with improved long-term survival rates in observational cohort studies. However, there is a dearth of randomized trials correlating the opening of persistently occluded infarct-related arteries with clinical outcomes. Recent technological advances have improved the success and safety of percutaneous revascularization, resulting in lower restenosis and reocclusion rates. A large randomized trial is needed to evaluate clinical outcomes with percutaneous revascularization versus medical management of occluded infarct-related arteries in the absence of inducible ischemia.

Angioplasty, Balloon, Coronary↗