Neurological damage to the fetus resulting from severe iodine deficiency during pregnancy.

Endemic cretinism is characterised by multiple neurological defects including deaf-mutism, diplegia, squint, and mental deficiency. The condition is widely prevalent in the Highlands of New Guinea in association with severe iodine deficiency. Previous studies have shown that iodised oil provides a very satisfactory correction of severe iodine deficiency in New Guinea. A controlled trial on the use of intramuscular iodised oil in the prevention of endemic cretinism was carried out in the Western Highlands of New Guinea and involved a population of approximately 8000. Subsequent follow-up over four years revealed 26 endemic cretins out of a total of 534 children born to mothers who had not received iodised oil; the mothers of 5 of these cretins were pregnant at the start of the trial. In comparison, 7 cases of endemic cretinism occurred among 498 children born to mothers who had been treated with iodised oil; in 6 of these 7 cases, the mother was pregnant when the trial commenced. It is concluded that intramuscular iodised oil is effective in the prevention of endemic cretinism and that, for it to be effective, it should be given prior to conception. This suggests that severe iodine deficiency in the mother produces neurological damage during fetal development.

Radionuclide angiographic study of the influence of dietary lipid supplements on cardiac function in the marmoset (Callithrix jacchus).

Radionuclide angiography was used to examine the influence of dietary fat on cardiac function in the common marmoset monkey (Callithrix jacchus jacchus) under barbiturate anaesthesia. Animals were fed for 6-8 months with a low fat (4.5%) reference diet or the same diet supplemented (12%) with sunflower seed oil or sheep fat. Although there was a tendency towards increased heart rate, left ventricular ejection fraction, peak ejection rate, and peak filling rate in both fat supplemented groups, significant increases in heart rate (+50%), peak ejection rate (+71%), and peak filling rate (+84%) were found with sheep fat supplementation, whereas only the vegetable oil supplement produced a significant improvement in left ventricular ejection fraction (+23%). There were no differences in resting blood pressure, and the main consequence of dietary fat supplementation was a major increase in apparent cardiac oxygen consumption (+58%) with the sheet fat diet, as determined by the pressure-rate index. Infusion of isoprenaline hydrochloride (0.2 microgram.kg-1.min-1) increased all indices of cardiac function towards common maxima. There were no differences in either the depth or duration of anaesthesia between dietary groups. It therefore is unlikely that this contributed to any of the observed dietary induced differences in cardiac function. It is suggested that dietary saturated animal fat increased cardiac work and oxygen consumption at rest to the extent that functional reserve to respond to stress was significantly diminished. Feeding a linoleic acid rich polyunsaturated vegetable oil supplement was, however, accompanied by evidence of some improvement in left ventricular ejection fraction.

Gated blood-pool studies of cardiac function in the rat and marmoset.

To develop a sensitive, relatively noninvasive method for monitoring cardiac function in small laboratory animals, equilibrium gated blood-pool imaging (with Tc-99m RBC) was adapted for use in an inbred strain of laboratory rats of 400-470 g body weight and in marmosets of 320-400 g body weight. A 2-mm pinhole collimator was fitted to the gamma camera to produce a distinct image of the left ventricle following intravenous injection of 5 mCi of pertechnetate. Reproducible and consistent data for heart rate, left-ventricular ejection fraction, and peak ejection rate were obtained from studies on 13 male rats and five marmosets maintained on constant diets. An intravenous injection of 0.4 microgram of isoprenaline led to predictable increases in heart rate, left-ventricular ejection fraction, and peak ejection rate, and provided evidence of the sensitivity of the method in monitoring heart function in small laboratory animals.

Detection of synovial cysts by transmission-emission scintigrams following intra-articular 169Yb-DTPA.

A new simple and safe technique for the detection of synovial cysts is described. This investigation employs combined transmission-emission scintigraphy following intra-articular injection of 169Yb-DTPA. Twenty-two joints were investigated in 18 patients. A high degree of correlation was found between clinical findings and the results of this investigation. The major advantages of this method are low local radiation to synovial linings, adequate visualisation of periarticular soft tissue, and small volumes required for intra-articular injection.

Endemic goitre in eastern New Guinea, with special reference to the use of iodized oil in prophylaxis and treatment.

PIP: Previous surveys have indicated a high goiter endemicity in the mountainous Huon peninsula of eastern New Guinea, a study was carried out in 1964 which indicated severe iodine deficiency in the inhabitants of the area. Trials were undertaken to determine whether the injection of iodized oil would correct that deficiency and what effect injections given in previous years had had. The results showed that, whereas the urinary iodine and 131 I uptake in New Guineans who had received iodized oil in 1957 were similar to those in untreated persons, yet a single 4 ml injection (2.15 g iodine) of iodized oil appeared substantially to correct iodine deficiency for 4-5 years. There was also a significant regression of goiter in 60 of 61 persons with easily visible goiters within 3 months of their receiving an injection. No case of thyrotoxicosis or iodism was seen in more than 2000 persons who were given injections. The authors recommend the injection of iodized oil particularly for the correction of iodine deficiency in children and in women of childbearing age whenever the efficacy of other measures is uncertain. The method is relatively inexpensive and well-suited to mass prophylaxis among people with a low standard of living. (author's)^ieng