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G B Tennant

Publications and source records attributed to G B Tennant.

27 records · Page 2Linked to original sources

Continuous-flow automation of the Lactobacillus casei serum folate assay.

A method is described for the continuous-flow automation of the serum folate assay using Lactobacillus casei. The total incubation period is approximately four hours. The growth response of the organism to folate is estimated by measuring the rate of reduction of 2,3,5-triphenyl tetrazolium chloride (TTC). A simple continuous culture apparatus is used to grow the inoculum. Supplementation of the assay medium is necessary to obtain parallel results. A statistical assessment shows a favourable comparison with the whole-serum tube assay using a chloramphenicol resistant strain of L. casei. The method is less sensitive to inhibitory substances than the tube assay.

Autoanalysis↗

The effect of medium redox potential on the folate-limited growth of Lactobacillus casei var. rhamnosus.

The medium redox potential (Eh) influenced the folate-limited growth of Lactobacillus casei; the growth response was maximal at an Eh of +120 mV (pH 6-35). At raised Eh serum folate would support less growth than pteroylglutamic acid, and the response to N5-methyl tetrahydrofolic acid was intermediate between them. Pteroylglutamic acid was not destroyed during 24 h incubation at 37 degrees C in medium with Eh values between +40 and +440 mV. Destruction of N5-methyl tetrahydrofolic acid occurred within 24 h when the medium Eh was greater than +125 mV. Folate was taken up rapidly by L. casei with an Eh optimum at +270 mV.

Ascorbic Acid↗

Acute folate deficiency in surgical patients on aminoacid/ethanol intravenous nutrition.

Acute folate deficiency with pancytopenia and megaloblastic haemopoiesis developed in four patients after abdominal operations; all four responded to folic acid over 3-9 days. Three of them had been given intravenous nutrition with amino-acid/ethanol before the blood changes developed. A prospective study of twenty-five surgical patients with gastrointestinal diseases revealed a high frequency of acutely developing negative folate balance. Megaloblastic haemopoiesis and consequent blood changes were found in five patients. Treatment with intravenous nutrition correlated strongly with a fall in serum-folate and megaloblastic haemopoiesis. Some surgical patients develop acute folate deficiency which may proceed to megaloblastic arrest of haemopoiesis. Patients receiving intravenous nutrition containing ethanol are especially prone to this complication, which may be life-threatening if untreated. It is not yet known whether other forms of intravenous nutrition carry a similar risk.

Acute Disease↗

Determination of iron in solutions containing iron complexes.

A method of estimating the iron content of solutions containing haemoglobin, ferritin, or ferrioxamine is described. Iron is released by treatment with acid permanganate and ascorbic acid before conventional determination by an Auto Analyzer technique.

Ascorbic Acid↗