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Biomedical subjects

M J Landon

Publications and source records attributed to M J Landon.

29 records · Page 2Linked to original sources
PubMed1975

Benzopyranopyridine derivatives. 1. Aminoalkyl derivatives of the azaxanthenes as bronchodilating agents.

The preparation of the four isomeric azaxanthones 3 and a number of their aromatic ring substituted derivatives is described. These ketones were converted into the title compounds which were examined for their biological properties. The most interesting compound in this series, the 1-methyl-4-piperidylidene derivative of 1-azaxanthene, shows the profile of an orally effective potent bronchodilating agent as well as a moderate antihistamine. Biological properties of this compound were compared to a number of antihistamines as well as known bronchodilating agents. Structure-activity relationships are also discussed.

Airway Resistance↗
PubMed1975

Transfer of folate to the fetus.

The accumulation of tritium-labelled folate in the product of conception was examined in eight women undergoing hysterotomy for termination of pregnancy. Folic acid containing a small quantity of tracer material (50n Ci/mug.) was injected intravenously 20 minutes before operation in 4 patients but 24 hours beforehand in the remainder. After operation, maternal blood, placenta, fetal blood, and fetal liver were examined for radioactivity as was the daily urine output during the patient's postoperative hospital stay. The results indicated that only 1/2 per cent of the injected material accumulated in the product of conception--uptake was primarily by fetal liver and no large placental pool of folate was involved. Approximately half of the injected load was excreted in the urine--the majority in the first 24 hours--and the remainder was presumed to have been retained by maternal tissues. Bioassay with L. casei and chromatography on TEAE cellulose suggested that extensive metabolism of the injected material had taken place and that fetal uptake might be more efficient than indicated by counting radioactivity alone.

Abortion, Induced↗
PubMed1969

Protein content of liquor amnii in prediction of severity of haemolytic disease of newborn.

Two series of cases of Rh isoimmunization were subjected to liquor examination for bilirubin and protein level. Series 1 comprised 298 cases for the years 1962 and 1963. Series 2 comprised 179 consecutive cases for 1967 in which preliminary selection for liquor examination had been made on the basis of previous history and maternal antibody titre.Bilirubin was measured as the liquor bilirubin ratio, and protein levels were estimated in series 1 by the Folin and Ciocalteau technique and in series 2 by a modified biuret method.Correlations with severity of haemolytic disease in the foetus was made, taking into account the stage of gestation of liquor examination. Both bilirubin and protein levels correlate with severity, but bilirubin is superior to protein. Interrelation of these measurements as bilirubin/protein ratio was inferior to bilirubin level as a method of forecasting severity.

Amniotic Fluid↗