It has been shown that LATS activity is mainly distributed in the fraction of immunoglobulin G (IgG) in the serum from hyperthyroid patients. The present paper examined the immunological character of LATS and the method for separation of LATS activity from LATS positive serum using DEAE-Cellulose and affinity chromatography methods.
LATS activity was distributed in the IgG fraction that could be separated by the DEAE-Cellulose column equilibrated with a 0.0175 M phosphate buffer, pH 6.3 from LATS positive serum. When LATS positive serum was fractionated by affinity chromatography on a Sepharose-bound antibody against human IgG, Fab of IgG and Fc of IgG, LATS activity was always retained in IgG fraction.
When LATS positive serum was fractionated by affinity chromatography on a Sepharose-bound anti-K chain, LATS activity was found in the fraction that reacted with the anti-K chain. Because of the low antibody titer of the anti-λ chain, LATS activity did not react with this antibody. By affinity chromatography on Sepharose-bound Concanavalin A, serum LATS activity was also retained in IgG fraction.
LATS activity could be separated from LATS positive serum without significant loss of biological activity by affinity chromatography. When IgG (1) was purified from the fraction by affinity chromatography on and-IgG (1) -bound Sepharose, about 80% of the original LATS activity was found in IgG (1) fraction. When the Fab fragment of IgG (1) was separated from papain hydrolysed IgG (1), using a Protein A-bound Sepharose column, a short-acting type of thyroid stimulating activity was found in only this fraction.
These data suggest that the biological activity of the thyroid stimulation is distributed mainly in the Fab fragment of IgG (1).

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TSH secretion in response to TRH was studied in patients with cerebrovascular diseases in order to elucidate the influence of cerebrovascular lesions on the hypothalamus-anterior pituitary function.
Blood specimens were obtained before and at intervals of 10, 20, 30, 40, 60, 90 and 120 minutes after the intravenous administration of 500 μg of TRH. Serum TSH was measured using the RIA method.
In 20 normal subjects, the serum TSH level before TRH administration was 1.0±1.4 μU/ml (MEAN±SD). Following the intravenous administration of TRH, serum TSH increased and reached the maximum level of 9.0±2.3 μU/mil at 30 minutes and returned near to the original level at 120 minutes. The response was the same for both male & female patients.
In 17 patients with cerebral hemorrhage, the response of serum TSH to TRH was variable, including the types of excess, delayed or low response besides the normal response. In severe cases, cases of acute phase and male patients, a marked variability in the response was observed.
In 8 patients with cerebral infarction, a low response of serum TSH to TRH was observed in all cases. There was no difference of the response with regard to severity of the diseases, duration after onset or sex difference of the patients.

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Prolactin (PRL) secretion in response to TRH was studied in patients with cerebrovascular diseases in order to elucidate the influence of cerebrovascular lesions on the hypothalamus-anterior pituitary function.
Blood specimens were obtained before and at intervals of 10, 20, 30, 40, 60, 90 and 120 minutes after the intravenous administration of 500 μg of TRH. Serum PRL was measured using the RIA method.
In 18 normal subjects, the serum PRL level before TRH administration was 9.7±1.7 ng/ml (MEAN±SD). Following the intravenous administration of TRH, serum PRL increased and reached the maximum level of 34.3±15.9 ng/ml at 20 minutes and returned near to the original level at 120 minutes. PRL levels in the female were slightly higher than those in the male.
In 17 patients with cerebral hemorrhage, a marked variability of the response of PRL to TRH was observed in each case. In female cases, the response of PRL to TRH was generally high as compared with that in male cases. In female patients the response was fairly good, even though serum PRL levels before TRH administration were high. On the other hand, a poor response was observed in severe male cases, whose PRL levels before administration were high.
In 8 patients with cerebral infarction, the response of PRL to TRH was nearly normal although the response was slightly delayed. In the patients with cerebral infarction, the response of TSH to TRH was low in all cases; that is, as in the previous paper, a dissociation between TSH and PRL response to TRH was observed. TSH and PRL response to TRH in patients with cerebrovascular diseases also suggested that PRL secretion was less impaired as compared with TSH secretion.

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A rapid and simple R.I.A. method for serum unconjugated estriol in pregnancy has been studied for its usefulness as a routine obstetrical test to assess fetal well-being.
Diluted serum samples or known amounts of standard estriol were applied with ¹²⁵I-estriol on pre-packed minicolumns of Sephadex G-25, followed by appropriately diluted antiserum. During incubation, the columns were counted in an Auto Well γ-System to read the total counts (T). After a 90 minute incubation period, the columns were eluted with a buffer solution to remove the bound fraction, and the free estriol remaining in the columns was counted (F).
Two quality control samples and sera from 74 pregnant women were analysed by this new method, and the results were compared to those obtained by the conventional radioimmunoassay method. The new column method is simple, specific and accurate. Results can be calculated within 4 hours after 30 sample sera are brought into the laboratory. Within and between assay coefficients, variations are 12.6 and 13.5%, respectively. This method correlates well with the results of the conventional method (r=0.7088, p<0.001), which requires almost 2 full days to process the same numbers of samples.
Results of clinical cases as well as advantages of measuring free-circulating estriol in pregnancy are discussed.

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In order to quantitate the feedback effect of estradiol (E₂) on the release of LH, serum LH and E₂ were measured in 27 ovulatory women daily during the menstrual cycle.
The initial rise of LH levels concomitantly occurred when serum E₂ concentrations over 100 pg/ml and over 200 pg/ml were maintained for 2~4 days and for 1~2 days respectively. The initial rises of LH levels were observed on the day of preovulatory E₂ peak.
A more detail analysis of the relationship between the two hormones were obtained in five subjects whose blood samples were taken at every eight hours around the time of ovulation. In one among five cases, samples were not obtained early enough to ascertain the relation of the E₂ peak to the LH peak. In 3 out of the 4 cases, the initial rises of LH levels occurred prior to or concomitant with the time of the E₂ peak. By average of all of the five cases, a significant initial rise of LH levels was observed simultaneously with the time of the E₂ peak.
These results suggest that the increase of the circulatory E₂ levels is essential for the initiation of LH surge and their decrease levels are an unrequired mechanism for the midcycle LH release.

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A 53 year old female with an autonomous functioning thyroid nodule was studied for pituitary thyrotropin response to TRH and chemical analysis of the thyroid tissue. ¹³¹I thyroid scintigram showed that the ¹³¹I uptake was much higher in the nodule than in the surrounding tissue. She had normal value for serum T₃ and T₄ and also had normal TSH response to 500 μg TRH. Pituitary TSH secretion in response to exogenous TRH was not suppressed, but ¹³¹I uptake of surrounding thyroid tissue was considerably suppressed. These data indicate that at a certain level, T₃ or T₄ secreted from the nodule may influence ¹³¹I uptake of para-nodular tissue more sensitively than pituitary response to exogenous TRH and suggest the existence of a “short-loop” negative feedback mechanism in the thyroid gland.
Immediately after surgery, nodular and para-nodular tissue were homogenized separately. Thyroid soluble proteins from both portions were fractionated respectively by sucrose gradient density ultra centrifugation, and the thyroglobulin content and the degree of iodination were determined. The thyroid soluble protein was also digested with pronase anaerobically and chromatographed, then subjected to the determination of ¹²⁷I distribution among each iodoamino acid.
The thyroglobulin content of the nodule was slightly lower than that of normal tissue but its degree of iodination and iodoamino acid distribution were similar to those of the normal thyroid. Photomicrograph of the nodular tissue revealed columnar epithelium and many vacuoles. This may suggest that the acceleration of hormone release is a primary alteration rather than hormone synthesis in the tissue of the autonomous functioning thyroid nodule. The thyroglobulin content and degree of iodination of para-nodular tissue were even lower than those in normal thyroid tissue, suggesting decreased hormone synthesis probably due to a “short-loop” negative feedback and/or slight inhibition of basal secretion of TSH, if present.

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It has been considered that hyperinsulinemia is one of the important factors in the development of obesity. With the purpose of investigating the mechanisms of hyperinsulinemia in obese rats induced by hypothalamic lesions (HTL), the time-caused changes in body weight, blood glucose and plasma immunoreactive insulin (IRI) levels in addition to histological changes in the pancreatic islet were studied.
The following results were obtained.
1. The development of obesity, a rise of plasma IRI level and an enlargement of pancreatic islets were found in HTL rats. The enlargement of pancreatic islets was directly proportional to body weight, index of obesity and plasma IRI level.
2. The B cells of the pancreatic islets of HTL rats revealed well-developed Golgi apparatus and rough endoplasmic reticulum, and numerous degranulated and pale secretory granules.
3. A number of mixed cells were shown in the periphery of the pancreatic islets of HTL rats.
4. Emiocytotic phenomena of the granular discharge were encountered frequently in the B cells of the pancreatic islets of HTL rats.
These histological findings of the B cells in HTL rats well reflected hypersecretion of insulin in this type of obesity.

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Changes in serum TSH, T₄ and T₃ concentrations after complete thyroidectomy were observed for 4 weeks in 9 euthyroid patients with thyroid carcinoma. Completeness of the thyroidectomy was confirmed by a ¹³¹I scintigram performed one or two months after the operation. Serum TSH levels rose progressively during the 4 weeks of observation, and a significant increase was noticed as early as 3 days after the thyroidectomy. Serum T₄ and T₃ concentrations decreased significantly 3 days and 18 hrs, respectively, after the thyroidectomy. A sharp decrease in serum T₃ concentrations within 18 hrs without a significant change in serum T₄ levels and possibly without a significant change in the amount of T₃ derived from T₄ suggests that the amount of T₃ secreted from the thyroid is large enough to affect serum T₃ concentrations. The rate of decrease of serum T₄ (t 1/2 : 16 days) or serum T₃ (t 1/2 : 23 days) after the 3rd day of the thyroidectomy was much slower than the rate of disappearance of labeled T₄ or T₃ reported previously. The slow decrease rate of serum T₃ is probably due to the conversion of T₄ to ₃ in peripheral tissues, and that of serum T₄ may be due to either the decrease in T₄ disposal rate in hypothyroidism or due to the release of T₄ from peripheral tissues to serum.

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Since the relationship between steroidogenic activity and morphological differentiation is not necessarily clear in the human adrenal cortex, aldosterone (Al), cortisol (F) and corticosterone (B) from the adrenal tissues cut into four small pieces (capsule and glomerulosa, outer fascicular, inner fascicular, and reticular zones) on a cryostat immediately after their removal at surgery were estimated by radioimmunoassay in 15 patients with adrenal diseases (8 primary aldosteronism, 1 idiopathic aldosteronism, 4 Cushing's syndrome and 2 pheochromocytoma) and 8 control subjects with other diseases.
A larger amount of Al was contained in the outer fascicular zone than in other zones in control subjects. Al showed a high value of 0.16~7.40 ng/mg tissue in adenomas of primary aldosteronism and a low value of 0~0.25 ng/mg tissue in adenomas of Cushing's syndrome. A high value of Al was detected in idiopathic aldosteronism but not in the remaining adrenal of primary aldosteronism. In Cushing's syndrome, F showed a high value of 2.58~12.3 ng/mg tissue in adenoma and a relatively low level of 0.77 ng/mg tissue in carcinoma. A larger amount of F and B was found in the inner fascicular zone than in other zones in the control subjects.
These results indicate that the corticosteroid content in each adrenal zone correlates with the morphological findings.

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