Healthy subjects aged 70-90 and 20-40 years were investigated for the level of reverse triiodothyronine (rT3). The mean level in 57 old subjects was higher and the triiodothyronine (T3) level lower than in 30 young persons. No negative correlation was observed. A serum T3 elevation caused by liothyronine administration (5-15 micrograms/day for two weeks) was not followed by a change of the mean rT3 level in 12 old subjects. After a single intramuscular thyrotropin (TSH) injection, the rT3 elevation lasted 24h longer in 19 old persons than in the 9 control ones, though the early rT3 response was similar in both groups. Propranolol administration (40 mg t.i.d. for a week) caused a similar rT3 elevation in old persons (n = 18) as in 12 young ones. From the indirect data it is concluded that the serum rT3 elevation in old age is a result of faster peripheral generation and not of increased production in the thyroid gland. The data do not indicate any change of rT3 metabolism. T4-T3 and T4-rT3 conversion are provoked by different enzymes. The elevation of rT3 might be a cause of the observed decrease in peripheral T3 generation in old subjects, acting by an inhibition of the T4-T3 conversion.
An increased secretion of gonadotropic hormone was found in hyperthyroid males despite the high basal serum total testosterone and oestradiol levels. This suggests that hyperthyroidism affects the responsiveness of the hypothalamic-pituitary axis to sexual steroid hormones. While in the hyperthyroid patients the elevation of the serum testosterone level in response to chorionic gonadotropin was lower than normally, the LH and FSH responses to LRH were increased. The results indicate that male hyperthyroidism is associated with a loss of responsiveness of the Leydig-cells to adequate stimuli, to which the pituitary reacts by a compensatory increase in its LH-secretion and by an increased reactivity to LRH. It is suggested that in addition to the direct effect of the increased thyroid hormone levels, a secondary elevation of the oestradiol concentration plays a major part in the alterations in question.
Cytotoxic activity and progesterone binding capacity of lymphocytes obtained from 135 pregnant women was tested. Cytotoxic activity of healthy pregnant women's lymphocytes was significantly lower (p less than 0.001), while progesterone binding capacity significantly higher (p less than 0.001), than those of lymphocytes obtained from women with threatened abortion or threatened premature labour. Neither cytotoxic activity nor progesterone binding capacity of the lymphocytes was influenced by gestational age. Furthermore, the number of previous pregnancies did not have any effect on either of the two parameters.
The changes in body weight after jejuno-ileal bypass surgery in 23 cases of massive obesity are reported. After an initial rapid weight reduction, body weight fell at a constant rate over six months. The weight reduction curves correspond to a zero order kinetics. After the first six months the rate of weight loss declined, but the weight continued to fall. By 12 to 24 months after the operation stabilization of body weight at an average level corresponding to 38% of the preoperative weight was attained.
The ultrastructure of the streak gonad was studied in 12 cases. Under the electron microscope the streak gonad displays fibroblasts, collagen fibres with the usual periodicity of 64-65 nm, and capillaries. The ultrastructure of the fibrous tissue of the streaks was similar in each patient regardless of the associated chromosome complements, and indistinguishable from that of polycystic and normal ovaries. The finding might suggest that the fibrosis in the streak gonad might be the result and not the cause of the early degeneration of the gonad.
A simple rapid method for the measurement of leucocyte adherence and adherence inhibition in tubes is described. The procedure is based on determining the amount of cell protein. We compared measurement of adherent cells by protein assay with the automated counting of the non-adherent cells in the tube leucocyte adherence inhibition test. Both procedures gave quantitatively similar results and a high statistical correlation was found between them. The results suggest that the protein assay is a reliable substitute for cell counting.
The pathomechanism of arrhythmias consecutive to a prolonged electrical systole --the long QT syndrome--was studied by local hypothermia in the heart. Local increase in the QT-interval (long QT with unhomogeneous repolarisation) was induced at a circumscribed area of the right ventricle by perfusion of the mid- and end-sections of the right coronary with cooled blood. The effect of local prolongation of QT on the arrhythmic susceptibility of the heart was studied by means of programmed electrical stimulation. Induced local hypothermia of the heart was found to increase the QT-interval of the ECG-tracings, also if QT had been corrected for heart rate. The local ECG tracings showed a considerable increase of the QT-interval at the selected right ventricular area under the effect of induced hypothermia but in relation to QT (ERP/QT) it diminished. The long QT in association with an unhomogeneous repolarization went hand in hand with an increased irritability of the heart. Early ventricular impulses were found to elicit extrasystolic runs, ventricular tachycardia or ventricular fibrillation. The results indicate that the cause of tachyarrhythmias consecutive to the long QT-syndrome may be ascribed to the inhomogeneity of repolarization on the one hand, and to the shortness of ERP in relation to the QT-duration on the other.
Radio-iron kinetic tests were performed in 7 patients with end-stage renal disease treated by hemodialysis; the study could be completed in 6 patients. The incorporation of radio-iron into the erythrocytes was 21% on average in patients with acute anemia. The red cell life-span determined in 4 patients became significantly shorter in 3 patients. Iron turnover in the bone marrow was significantly lower than normal, the rate of ineffective erythropoiesis being higher. Serum ferritin levels were significantly higher, and tissue and extravascular iron turnover was found to be enhanced compared to normal. At the same time, serum iron level was normal. The data on iron turnover indicated deficient hemopoiesis in the bone marrow, due partly to the lack of erythropoietin and partly to the insufficiency of the BFU-E (burst forming units) and CFU-E (colony-forming units) reserves. Undoubtedly, this was a consequence of the uremia.
Significant retardation in body and kidney growth and in renal glomerular and proximal tubular development was observed in hypothyroid rats in comparison with euthyroid controls. Body mass was found to increase by 40% but kidney mass only by 3.5% over a period of 3 weeks following thyroidectomy in contrast to an average increment of 178 and 113%, respectively, in normal animals. Dissociation was found also in the development of glomeruli and proximal tubules: glomerular size correlated with body weight while tubular size with kidney weight. Single nephron glomerular filtration rate was adapted not to the glomerular as normally but rather to the tubular volume thereby compensating functionally for the dimensional glomerulotubular imbalance. However, despite the decreased filtered and excreted amount of sodium relative to the body weight sodium balance was maintained by depressed tubular reabsorption which was uniformly observed in thyroid deficiency. Because of the uncertainty regarding the direct action of thyroid hormones on the tubular function it is assumed that decreased tubular sodium reabsorption is principally caused by the mechanism subserving the maintenance of sodium balance also in salt loaded normal and sodium sensitive Dahl's rats. This seems to be supported by the exaggerated natriuresis observed both in hypothyroid and sodium sensitive Dahl's rats after saline infusion. Justification of the proposed mechanism needs further investigation.
A case of isolated granulomatous gastritis observed in a 66-year-old female patient is reported. The gastric granulomatosis gave rise to pyloric stenosis, and at the first explorative laparotomy the change was misdiagnosed for an inoperable tumour. Gastroscopy then revealed the presence of a peptic ulcer, which healed completely on drug therapy. At the second surgical intervention undertaken on account of a relapse after 2 years, Billroth II type resection of the stomach led to complete recovery; the patient has been free from complaints ever since. It is suggested that in addition to peptic ulcer and tumour, isolated gastric granulomatosis should be taken into consideration as the underlying mechanism of pyloric stenosis.
Intravenous infusion of bombesin (0.9 micrograms/kg/hour) caused a significant increase in gastric acid secretion and serum gastrin concentration in 8 duodenal ulcer patients. Intravenous infusion of calcitonin (2 MRCU/kg/hour) produced a significant decrease in gastric acid output and in integrated gastrin output produced by bombesin infusion (0.9 micrograms/kg/hour) in the same 8 patients with duodenal ulcer. Percentage of inhibition was 49.7 and 40.8, respectively. Simultaneous infusion of calcitonin and bombesin caused no significant difference in serum calcium concentration. It is suggested that the inhibitory effect of calcitonin on acid secretion elicited by bombesin is produced, at least in part, by a fall in serum gastrin caused by bombesin. In addition, calcitonin might directly inhibit the parietal cells by releasing endogenous gastric somatostatin.
Studies of the successive phases of iodine kinetics and their description on a quantitative basis provide important clues to the diagnostic differentiation of thyroid diseases and help to gain closer insight into the mechanism of action of the drugs to watch the diseases are expected to respond. It was attempted to establish quantitative parameters by experiments in vivo and in vitro in order to gain reliable information on iodine kinetics. This objective was approached from two angles: the first was to develop and to refine radioisotope methods, the second to evaluate the results on a quantitative basis by means of compartment models. Three- seven- and ten-compartment models were designed on these grounds for the calculation of the parameters suited for the description of iodine kinetics. The results were matched by analogue and by digital computer. The parameters thus obtained were found to be reliable indicators of te drug induced effects. Though the method has been used for the evaluation of animal experiments, it is regarded as suitable for the assessment of diagnostic and pharmacokinetic data in humans as well.
Six patients subjected to jejuno-ileal bypass surgery for obesity were studied for vitamin B12 absorption by the use of the Schilling test, together with measurement of the serum B12 level preoperatively and at 2, 6, 12, 18 and 24 months after the operation. During the follow-up period of 2 years, the serum vitamin B12 level gradually declined to abnormally low values. A postoperative fall of the originally normal vitamin B12 absorption to abnormal values was found. Oral administration of tetracycline resulted in a transitory improvement of the results by the Schilling test, but after its discontinuation serve vitamin-B12 malabsorption was again demonstrable. The importance of parenteral vitamin B12 administration after jejuno-ileal bypass surgery is emphasized.
Regulation of limb circulation was studied by the use of the venous isotope dilution technique in 35 patients with leg varicosities. The circulatory parameters of 54 patients with normal limb circulation served as control. The various types of varicosity revealed characteristic circulatory patterns. (i) In the cases of congenital, "juvenile", varicosity limb blood flow is high, the limb AV-O2 difference is very slight and limb O2 uptake is normal. (ii) In secondary varicosity consecutive to thrombophlebitis the limb (total) blood flow is slightly reduced, the limb AV-O2 difference is smaller than normal and O2 uptake by the extremital tissues is diminished. (iii) In non-congenital, primary varicosity, i.e. in the most common form, limb blood flow is normal, the limb vascular resistance is slightly increased. The possibilities of the production of an AV shunt and the clinical implications of the circulatory changes accompanying the various types of varicosity are discussed.
