The red cell triiodothyronine uptake technique as used in our hospital is described. Incubation time is of almost no importance. The temperature during incubation should be 37° C. Further improvement of the technique is obtained when all blood samples are brought up to 40 % haematocrit prior to incubation.
Clinical results are discussed. It is yet too early to give a definite assessment of its clinical value, but it is definitely superior to the measurement of the BMR.
A technique is described, which resembles the in vitro red cell triiodothyronine uptake test for the investigation of thyroid function, but which requires only 0.5 ml of plasma. The uptake of radio-triiodothyronine is measured by a method in which resin replaces the erythrocytes. Thus the variable of the red cell substrate is excluded. By means of the resin technique described, an uptake of 14–27 % was found in a group of 130 euthyroid subjects. Fourteen plasma samples from hyperthyroid patients were investigated, which showed an uptake range of 25–40 % (one plasma sample from this group had an uptake of 25.8, i. e. within the normal range). In one case of hypothyroidism, an uptake of 10.7 % was found. It is not yet possible to state the level of uptake below which the diagnosis of hypothyroidism should be considered.
The effect of different factors like the quantity of resin, incubationtemperature and incubation-time, p H and others have been investigated. The results are discussed.
In 1952 and 1953 we published some investigations on the colour changes in hypophysectomized frogs (Rana esculenta). Two types of colour change were observed. The first type, in which the entire body becomes darker, was called »total discoloration«. The second type, in which only the hindpart of the body becomes darker, was called »pregnancy discoloration« or the Konsuloff reaction (Fig. 1). The term »pregnancy discoloration« was chosen, because this type of colour change occurs following injections of pregnancy urine, pregnancy serum, aqueous extracts of early placentae, of very pure human chorionic gonadotrophin and of pregnant mares' serum.
The »total discoloration« is obtained following injections of extracts from the posterior or intermediate lobes of the hypophysis (intermedin). The same type of colour change was also obtained following injections of commercial preparations containing anterior lobe hormones: corticotrophin (Cortrophine-Organon), thyrotrophic-gonadotrophic hormone (Ambinon-Organon), gonadotrophin from horse hypophyses (Gonadotrophine-Squibb
Abstract. We have investigated the nature of the α-melanocyte stimulating hormone-like immunoreactivity (α-MSH-LI) in blood and cerebrospinal fluid (CSF) of the rat. Blood and CSF from intact animals were subjected to high pressure liquid chromatography (HPLC) followed by a radioimmunoassay (RIA) specific for the C-terminal part of the α-MSH molecule. It appeared that in both body fluids the predomiant α-MSH-LI co-migrated with synthetic α-MSH and not with its des-acetyl or di-acetyl analogues. We conclude that α-MSH is the predominant form of α-MSH-LI circulating in plasma and CSF of rats from our Wistar strain.
As evidently the currently used iodine tracer doses are rather large for internal administration to human subjects, special attention was paid to an in vitro laboratory thyroid test, the so called resin triiodothyronine (T3) uptake test. With this method the degree of saturation of blood plasma with thyroxine is measured indirectly by incubating the plasma with an Amberlite CG 50 type and triiodothyronine labeled with I131. After subsequent separation and washing of the resin, diagnostic conclusions can be drawn from the percentage of the labeled T3 that remains fixed to the resin. The resin acts as a substrate to bind the exogenous T3 that is not preferentially bound by the plasma.
A higher percentage T3 is bound to the resin in hyperthyroidism, because the binding sites in the plasma are relatively more saturated by stable endogenous thyroxine and so more T3 is available for uptake by the resin.
The results
The kinetics of thyroxin metabolism in adult man has been studied extensively (1, 2). In children only the data of Haddad (3) on 17 euthyroid children between 3 and 9 years of age are available.
Thyroxin turnover studies were carried out in 19 children between 3 and 15 years of age: euthyroid control 5; pituitary insufficiency 4; hypothyroidism during treatment 2; off treatment for 2 months 1; adolescent goiter 3; obesity 3 and one 3 years old eumetabolic child who had an iodine goiter at birth. Fractional rate of turnover K, thyroxin degradation rate D and other data were calculated according to Sterling cs. (2). In part of the children the thyroid gland was blocked with propylthiouracil; in the others also the thyroxin secretion rate S was calculated according to Ingbar cs. (1).
Results: Values for D and S were in good agreement. Mean value for K in 5 normal
The fact that no international standard preparation is available for comparative assay of urinary gonadotrophins, derived from non pregnant individuals, forms one of the great difficulties in the estimation of these substances. Results have therefore to be expressed in terms of arbitrary »rat« and »mouse« units. In clinical studies the most widely used units has been the quantity of extract producing a doubling of the uterus weight in intact immature mice (Klinefelter, Albright & Griswold, 1943). It has since long been generally recognized, that as a gonadotrophin assay, the uterine weight method is not specific for either F. S. H. or L. H. (I. C. S. H.) activity. In fact, this assay method is an indirect one: first the ovaries are stimulated and then enlargement of the uterus is caused by ovarian estrogens.
Part of the present work was undertaken, to ascertain whether it would be a valid procedure to
Whereas hairgrowth in certain areas of the body surface – e. g. axillary and pubic hair, hair on the trunk and extremities, the beard and the eyebrows – is unmistakably subject to hormonal influences, it has not hitherto been demonstrated whether the cranial hair is influenced by endocrine factors. Although the administration of testosterone may cause loss of hair on the forehead and the apex of the cranium, a ring of hair remains intact on the occipital part of the skull and above the ears.
Alopecia areata is a condition which often affects the cranial hair, in which case baldness may spread over the entire skull (alopecia totalis); in its further spread, too, alopecia areata exceeds the limits of the various areas of hairgrowth, sometimes to such an extent as to result in complete lack of hair over the entire body surface (alopecia universalis).
The question of the possible importance
The risk of developing type 2 diabetes mellitus (T2DM) is exceptionally high among both native and migrant South Asians. T2DM occurs more often and at a younger age and lower BMI, and the risk of coronary artery and cerebrovascular disease, and renal complications is higher for South Asians compared with people of White Caucasian descent. The high prevalence of T2DM and its related complications in South Asians, which comprise one-fifth of the total world's population, poses a major health and socioeconomic burden. The underlying cause of this excess risk, however, is still not completely understood. Therefore, gaining insight into the pathogenesis of T2DM in South Asians is of great importance. The predominant mechanism, in this ethnicity seems to be insulin resistance (IR) rather than an impaired β-cell function. In this systematic review, we describe several possible mechanisms that may underlie or contribute to the increased IR observed in South Asians.
Abstract. Intracerebroventricular administration of dynorphin-(1-13) inhibits dose-dependently plasma vasopressin level in normal as well as in water-deprived rats, whereas systemic (subcutaneous) administration of this opioid peptide is ineffective in this respect. Simultaneous subcutaneous, but not intracerebroventricular, administration of naloxone prevents the suppressive effect of dynorphin-(1-13) on plasma vasopressin levels.
