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Biomedical subjects

D G Nancekievill

Publications and source records attributed to D G Nancekievill.

11 recordsLinked to original sources
PubMed1984

Prevention of nitrous oxide-induced megaloblastic changes in bone marrow using folinic acid.

Prolonged anaesthesia with nitrous oxide inactivates vitamin B12 and impairs DNA synthesis in bone marrow cells. The use of parenteral folinic acid in the prevention of these toxic effects has been studied in 11 patients, ventilated artificially with nitrous oxide in oxygen for 24 h. Bone marrow aspirates were performed before and after exposure to nitrous oxide. They were assessed morphologically and with the deoxyuridine suppression test. Folinic acid 30 mg immediately before anaesthesia and 30 mg 12 h later, prevented the toxic effects of nitrous oxide in four out of five patients, whereas smaller amounts of folinic acid (between 3 and 36 mg in 24 h), were ineffective.

Adolescent↗
PubMed1983

An apparatus for the delivery of 50% premixed nitrous oxide and oxygen on demand or by controlled ventilation.

A small, portable and robust apparatus for the administration of 50% premixed nitrous oxide and oxygen mixture for analgesia for hospital and emergency use is described. The equipment can deliver the mixture on demand or by intermittent positive pressure ventilation. It has important advantages over earlier devices particularly in the accident and emergency field in which it has already proved successful.

Anesthesia, Inhalation↗
PubMed1979

The effect of nitrous oxide on the cell cycle in human bone marrow.

The effect of 24 h exposure to nitrous oxide on the cell division cycle in human bone marrow has been studied in vivo using the technique of DNA flow microfluorimetry. All patients who received nitrous oxide showed a significant increase in the proportion of early S-phase cells with a decrease in late S, G2 and mitotic cells. These changes resemble those seen following the use of S-phase-specific cytotoxic drugs. Control patients showed no such effect. Parallel studies have suggested that interference with the function of vitamin B12 underlies this response. Nitrous oxide may provide a convenient method for studying the cell kinetic aspects of acute B12 deficiency and the possibility of using it to increase the therapeutic index of antitumour drugs is discussed.

Bone Marrow↗
PubMed1978

Megaloblastic haemopoiesis in patients receiving nitrous oxide.

In a prospective study the incidence of megaloblastic change after ventilation with nitrous oxide for periods of up to 24 h has been determined and the cause of the altered D.N.A. synthesis studied with the deoxyuridine (dU) suppression test in 22 patients undergoing cardiac bypass surgery. 8 patients who received nitrous oxide and oxygen for 24 h had megaloblastic bone-marrow aspirates and abnormal dU suppression tests at the end of ventilation. 5 patients who received no nitrous oxide had normoblastic aspirates and normal dU suppression test. Of the remaining 9 patients, who received nitrous oxide during the operation only, 3 had abnormal dU suppression tests at 24 h. The abnormality revealed by the dU suppression tests was identical with that found in vitamin-B12 deficiency, but the patients' serum-B12 concentrations were normal. These results suggest that nitrous oxide interferes with the function of vitamin B12. Nitrous oxide oxidises vitamin B12 in vitro, and probably also in vivo when premixed 50% nitrous oxide and 50% oxygen mixture ('Entonox') is given.

Acute Disease↗
PubMed1975

The role of hospital medical teams at a major accident.

Despite an apparently adequate major accident plan which has been used successfully on two previous occasions, considerable difficulties were experienced by the mobile medical teams at the scene of the Moorgate tube train accident. The authors have attempted to describe the role and organisation of mobile medical teams placing particular emphasis on a simple and flexible plan.

Accidents↗