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Biomedical subjects

A Macdonald

Publications and source records attributed to A Macdonald.

At least 91 records · Page 5Linked to original sources

Ward design in relation to postoperative wound infection: 3.

The wound infection rates, nasal carriage rates, and nasal colonization rates were studied in a recently built surgical unit for two years when it was first opened. Five years later a further two-year period of study was undertaken.Judging by the incidence of postoperative wound infection, as far as both Staphylococcus pyogenes and Gram-negative organisms are concerned, there is no evidence that the environment has become less safe with use over the seven-year period since opening.

Bacteria↗

Metabolic alterations produced in the liver by chronic ethanol administration. Comparison between the effects produced by ethanol and by thyroid hormones.

1. Liver slices from rats treated with thyroxine show an increased rate of O(2) consumption. The extra consumption, but not the basal respiration, can be abolished by ouabain. 2. Dinitrophenol is not effective in increasing the rate of O(2) consumption of liver slices from thyroxine-treated animals but its effectiveness can be recovered in the presence of ouabain. 3. (Na(+)+K(+))-stimulated adenosine triphosphatase activity of liver was increased by administration of thyroxine in vivo. No changes were found in total Mg(2+)-stimulated adenosine triphosphatase activity. 4. Mitochondrial alpha-glycerophosphate dehydrogenase and microsomal NADPH oxidase activity were increased by both thyroxine and chronic ethanol treatment. 5. Liver slices from animals chronically treated with ethanol synthesize urea at an increased rate. 6. Mitochondrial size (section area) is markedly increased in the liver of animals chronically treated with ethanol. 7. Acute administration of ethanol in doses of 4 and 6g/kg significantly increases the uptake of (131)I-labelled thyroxine by the liver. 8. Work reported here, along with results from other investigators, indicates marked similarities between the effects produced in the liver by chronic administration of ethanol and by thyroid hormones.

Journal Article↗

Changes from high potassium (hk) to low potassium (lk) in bovine red cells.

Red cells of newborn calves contain 105-110 mmole K(+) and 1-5 mmole Na(+) per liter of cells. As the animals age the K(+) content decreases to a value of 25-30 mmole/liter of cells after about 60 days. At approximately the same time, the sodium content reaches a value of 60-70 mmole/liter. The time required for half change (t((1/2))) is 35-37 days for both Na(+) and K(+). The activity of (Na + K)-adenosine triphosphatase (ATPase) and the influx of K(42) and Rb(86) into the red cells are high at birth and are reduced to 5 and 15% of their original values, respectively, in mature animals. t((1/2)) for both is of the order of 30-35 days. The membrane Mg-ATPase activity is also high at birth and is reduced with a t((1/2)) of 28-32 days to a final value of about 20% of its activity at birth. Separation of red cells according to their age showed that, in animals at the age of transition, newly formed red cells contain a higher K/Na ratio and a higher active transport capacity than older red cells of the same animal. It is suggested that the changes observed are a reflection of the average age of the red cell population as the animal grows.

Adenosine Triphosphatases↗

Ward design in relation to postoperative wound infection. I.

The incidence of postoperative wound infection in a general surgical unit is reported both before and after transfer from a "Nightingale" type multibed ward to a new "race-track" type of surgical ward with controlled ventilation and with 40% of its beds in single rooms. Following transfer postoperative wound infection was reduced by about 55%.With the use of certain types of staphylococcal infection as an index of cross-infection it was shown that transfer was followed by a 72% reduction in cross-infection of wounds.A case is made for control of hospital cross-infection in surgical wards. The principal change in ward architecture resulting from the transfer was the extensive division of ward space into separate compartments (40% of single-bed rooms), which make controlled ventilation easier.

Air Microbiology↗

Ward design in relation to postoperative wound infection. II.

A detailed investigation has been carried out into the behaviour of wounds after 1,000 general surgical operations, about equal numbers of patients having been studied in two different ward and operating theatre environments. The wound sepsis rate was reduced after transfer to the new type of ward. It is concluded that features of the new ward environment were responsible for the observed fall in the incidence of cross-infection.

Cross Infection↗