Lymphoid tissue in the thyroid gland and thymus of patients with primary thyrotoxicosis

The amount of lymphoid tissue in the thyroid gland and thymus at the time of partial thyroidectomy was measured quantitatively with the point-counting technique.

The normal pattern of age involution of the thymus was established in patients with non-toxic nodular goitre. In all the patients with thyrotoxicosis the thymus is hyperplastic; after pretreatment with antithyroid drugs, such as carbimazole, the pattern of age involution is similar to that in the control subjects, whereas after propranolol therapy very little age involution is seen. Patients treated with antithyroid drugs show much less lymphoid infiltration of the thyroid gland than those prepared with propranolol.

The Elimination Reaction of Vicinal Disulphonyloxy Compounds with Sodium Iodide

The elimination of two tosyloxy groups from vicinal ditosyloxy compounds by reaction with sodium iodide has been investigated. The reaction involves nucleophilic displacement of one tosyloxy group ; this is followed by the simultaneous elimination of the second tosyloxy group and iodine, if the steric arrangement is favourable; if it is unfavourable, a second displacement by an iodide ion probably occurs to give substituents having a trans-arrangement suitable for elimination.�In one case, that of the ditosyl derivative of trans-cyclohexane-1,2-diol, the intermediate cis-2-iodocyclohexyl toluene-p-sulphonate was isolated.

Iron-59 metabolism as an index of erythropoietic damage and recovery in monkeys exposed to nuclear radiations

Monkeys exposed to ionizing nuclear radiations were studied for changes in radio-iron utilization by erythrogenic tissues. Twenty-eight hours after exposure, Fe59Cl3 was injected; twenty-four hours later the first blood sample was drawn. Iron incorporation by the irradiated animals indicated marked erythropoietic depression. At 52 hours after exposure, average uptake in irradiated animals was 2.1% as compared to 10.7% in the controls. Only 3 of the original 10 irradiates survived. On repeating iron-59 injection in supplemented groups of survivors 34 days after exposure, repair and active erythropoiesis were indicated. Plasma iron exhibited periods of both hyper- and hypoferremia. Those animals which died were consistently hypoferremic for 2–3 days prior to death.

CHOLINE DEFICIENCY IN THE GUINEA PIG

Young guinea pigs (4–6 days of age) fed a choline-deficient diet grew slowly and died within 3 to 4 weeks, at which time the livers showed only traces of stainable fat. Animals fed the diet supplemented with choline grew at the rate of 5.5 to 6.0 g. per day. Guinea pigs transferred from a complete diet to a choline-deficient diet after 3 to 4 weeks suffered an immediate retardation in growth but no mortality occurred (up to 6 weeks). A decrease in total body fat was noted. After 4 weeks, stainable fat was present in the liver. A small but definite increase in total liver fat occurred at 6 weeks. The guinea pig, like the chick, is unable to place the first methyl group on the ethanolamine moiety of choline, but betaine plus monomethylaminoethanol was as effective as choline in overcoming a deficiency of the latter.

CHOLINE DEFICIENCY IN THE GUINEA PIG

Young guinea pigs (4–6 days of age) fed a choline-deficient diet grew slowly and died within 3 to 4 weeks, at which time the livers showed only traces of stainable fat. Animals fed the diet supplemented with choline grew at the rate of 5.5 to 6.0 g. per day. Guinea pigs transferred from a complete diet to a choline-deficient diet after 3 to 4 weeks suffered an immediate retardation in growth but no mortality occurred (up to 6 weeks). A decrease in total body fat was noted. After 4 weeks, stainable fat was present in the liver. A small but definite increase in total liver fat occurred at 6 weeks. The guinea pig, like the chick, is unable to place the first methyl group on the ethanolamine moiety of choline, but betaine plus monomethylaminoethanol was as effective as choline in overcoming a deficiency of the latter.

LIPOTROPIC DOSE–RESPONSE STUDIES IN RATS: COMPARISONS OF CHOLINE, BETAINE, AND METHIONINE

Dose–response curves have been obtained showing the effects, in weanling rats, of graded doses of choline, betaine, and methionine, respectively, when added to a hypolipotropic diet. A comparison of the lipotropic activity made on the steep portions of the dose–response curves showed that at all liver fat values from normal to 27%, the ratio of betaine to choline necessary to produce a given level of fat was 3: 1. Essentially similar ratios were observed in the prevention of hemorrhagic kidney lesions and in the stimulation of growth. Methionine, at the lower doses, was as effective as betaine, on a molar basis, in maintaining a given level of liver fat. However, the higher levels of methionine were not as efficient. Methionine at the highest dosage used did not bring the liver fat entirely within the normal range.