bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR ARGININE VASOPRESSIN
Authors: Freisenhausen Heinz-Dieter , Frahm Heinz , Čabrijan Tomislav , Wiethold Gerhard 
Published: December 2008

ABSTRACT
The development of a sensitive and specific radioimmunoassay for vasopressin is described. Antibodies were successfully produced following the coupling of synthetic arginine vasopressin with bovine serum albumin carried out with carbodiimide. In order to standardize the assay, the labelled hormone has to be separated twice using a DEAE-Sephadex-A-25 column and thin layer chromatography with cellulose plates. A further condition to obtain a reproducible standard curve is the use of a pure arginine vasopressin checked by cellulose chromatography. Most of the vasopressin batches available do not fulfil this requirement of purity. With the method described, vasopressin can be determined in unextracted human urine. The lower limit of detection is 2 pg/ml. Normal values are in the range of 67.5 ± 34.3 ng/24 h (x̄ ± sd, n = 45). No significant difference of AVP excretion was found between men and women. The usefulness of the assay is demonstrated in patients with hypothalamic or pituitary disorders.
THE PANCREATIC ALPHA AND BETA CELLS RESPONSES TO 1-ARGININE AND INSULIN-INDUCED HYPOGLYCAEMIA IN HYPERTHYROIDISM
Authors: Shima K. , Sawazaki N. , Tanaka R. , Morishila S. , Tarui S. , Nishikawa M. 
Published: December 2008

ABSTRACT
In order to assess the secretory capacity of the pancreatic alpha and beta cells in patients with hyperthyroidism, the plasma glucagon and insulin responses to 1-arginine and insulin-induced hypoglycaemia in 12 patients were compared with those in 6 normal subjects. The response of beta cell to hypoglycaemia was evaluated by measuring the decrease in plasma C-peptide immunoreactivity (CPR) level.
There was a negligible rise in blood glucose and plasma insulin levels in the patients, whereas a significant increase occurred in normal subjects during the arginine infusion. Although no difference in the fasting plasma glucagon concentration between the two groups was found, 30 min after the beginning of the arginine infusion, the plasma glucagon levels rose to a peak of 252 ± 35 pg/ml in the patients, a value significantly lower than 387 ± 53 pg/ml in the normal subjects. The insulin-induced hypoglycaemia caused no significant difference in the peak values of plasma glucagon between the two groups. There was a significant fall in plasma CPR after the insulin injection in both groups but the per cent decrement was rather greater in the patients than in the normal subjects.
These results suggest that the pancreatic alpha and beta cells in hyperthyroidism have a functional defect in response to 1-arginine but not to insulin-induced hypoglycaemia. The mechanism involved in these disorders is discussed.
DEMONSTRATION OF A PITUITARY GONADOTROPHIN HORMONE ACTIVITY IN THE MALE FOETAL MOUSE
Authors: Pointis G. , Mahoudeau J. A. 
Published: December 2008

ABSTRACT
The testosterone production by 18-days-old foetal mouse testis was measured in an organ culture system, by RIA in the culture medium. This production was time-dependent, and could be stimulated by ovine LH and age-matched foetal pituitary. The gonadotrophin activity derived from foetal pituitary appeared to be released into the culture medium as a limited reserve. These data clearly show that a biologically active gonadotrophin material is present in the pituitary of the 18-days-old mouse foetus.
A CASE OF MALE PSEUDOHERMAPHRODITISM ASSOCIATED WITH ELEVATED LH, NORMAL FSH AND LOW TESTOSTERONE POSSIBLY DUE TO THE SECRETION OF AN ABNORMAL LH MOLECULE
Authors: Park I. James , Burnett Lonnie S. , Jones Howard W. , Migeon Claude J. , Blizzard Robert M. 
Published: December 2008

ABSTRACT
A 27 year old female is described who had 46,XY chromosome complement, ambiguous external genitalia with elevated LH, slightly above normal FSH and low testosterone. Her plasma testosterone level increased 15–20 fold after HCG stimulation (5000 IU × 3). then returned to pre-stimulation level 3 months later. This was possibly due to the secretion of an abnormal LH molecule which is immunoreactive but biologically inactive in the human.
RADIOIMMUNOASSAY OF THYROTROPHIN RELEASING HORMONE IN HUMAN SERUM AND ITS CLINICAL APPLICATION
Authors: Mitsuma Terunori , Hirooka Yoshibumi , Nihei Noriyuki 
Published: December 2008

ABSTRACT
A radioimmunoassay for thyrotrophin releasing hormone (TRH) in human serum is described.
Inactivation of TRH immunoreactivity by serum is prevented by a mixture of 8-hydroxyquinoline sulphate and Tween 20. This persisted for a long period and at the concentration used in this study did not affect the TRH value. The TRH was extracted from serum with methanol. The results of the recovery experiment, dilution curve of high TRH serum, intra-assay reproducibility and inter-assay variation were quite satisfactory. The lowest detectable amount in this system was 5.0 pg/ml.
Immunoreactive TRH levels in the serum were less than 60 pg/ml in normal subjects, were below the limit of detectability in hyperthyroid patients, were 40 to 400 pg/ml in primary hypothyroid patients, were 100 to 600 pg/ml in pituitary hypothyroid patients and below the limit of detectability in hypothalamic hypothyroid patients.
In primary hypothyroidism, immunoreactive TRH concentrations in the serum fell to in the normal range during thyroxine substitution. In most cases of hyperthyroidism, immunoreactive TRH concentrations in the serum increased to 5.0 pg/ml or more during antithyroid drug treatment, but in a few cases the level remained below the limit of detectability even though thyroid hormone levels were in the normal range.
The above data suggest that this assay system would be a useful tool to study the role of TRH in the hypothalamo-pituitary-thyroid axis.
EFFECT OF PROLACTIN SUPPRESSION ON GONADOTROPHIC SECRETION IN THE PUERPERIUM
Authors: Villalobos Hugo , Canales Elias S. , Zárate Arturo , Soria Jorge , MacGregor Carlos 
Published: December 2008

ABSTRACT
Serum levels of prolactin (PRL), FSH, LH and oestradiol-17β were determined by radioimmunoassay in 57 lactating women and in 20 women in whom lactation was inhibited by ergocryptine (CB-154). Women who breast fed their infants exhibited high PRL levels which abruptly declined within 48 h post-partum, and remained low for the duration of the study. Serum FSH was undetectable during the first week post-partum in lactating as well as in CB-154 treated women. Thereafter, lactating women showed increasing FSH levels which reached a maximum by the third week post-partum. These FSH values were higher in lactating women than in the CBS-154 treated group. In contrast, LH levels were higher in those women receiving CB-154. Serum oestradiol-17β remained in low levels throughout the study, and no difference was observed between the two groups of subjects. From these results it seems that: 1) inhibition of PRL secretion leads to a faster recovery of gonadotrophin secretion toward the "menstrual type", and 2) PRL suppression produces no effect on the ovarian oestrogen production.
CONCENTRATION OF THYROID HORMONE IN SKELETAL MUSCLE
Authors: van Hardeveld C. , Kassenaar A. A. H. 
Published: December 2008

ABSTRACT
1. A modified method for the determination of thyroid hormone levels in muscle is described.
2. The levels of T4 and T3 in skeletal muscle tissue of rats lie in the same range.
3. The level of T4 in plasma is about a hundred times higher than that of T3.
4. To remove plasma hormones from the tissue in which hormone levels are to be determined, the animals should be perfused with saline before tissue samples are taken.
ANTI-INSULIN-ANTIBODIES AND LATE DIABETIC COMPLICATIONS
Authors: Andersen O. Ortved 
Published: December 2008

ABSTRACT
Two hundred and seventy-four insulin-dependent juvenile diabetics were examined. One hundred and sixty-six patients were without late diabetic complications, while 108 patients had one or more complications. At the time of the investigation patients with and without complications were found to have the same insulin requirement. Retrospectively it was observed, that after treatment for 10 years the insulin requirement was significantly higher among patients who had developed complications after treatment for 19 years as compared to patients who after 19 years of treatment had not developed complications.
One hundred and eighty-four patients, of which 110 were without and 74 with late diabetic complications were examined for anti-insulin-anti-bodies. Patients with complications, especially those with early onset of proliferative retinopathy or nephropathy had a slightly although insignificantly elevated plasma insulin-binding capacity. The frequency of high titres was significantly greater among patients with complications as compared to the frequency in patients without complications. The observations support the assumption, that insulin-anti-insulin-antibody complexes may aggravate the vascular complications.
EXISTENCE OF BIG AND LITTLE FORMS OF LUTEINIZING HORMONE IN HUMAN SERUM
Authors: Graesslin D. , Leidenberger F. A. , Lichtenberg V. , Glismann D. , Hess N. , Czygan P. J. , Bettendorf G. 
Published: December 2008

ABSTRACT
Serum fractions from normal subjects obtained by gel chromatography have been investigated using three different assay systems: radioimmunoassay (RIA), radioligand receptor assay (RRA), and testosterone production assay (TPA). The bulk of immunoassayable and "bioassayable" LH-activity was found in two fractions differing widely in their molecular size. The slower moving component, designated as "little" LH, migrated identical to the radioiodinated pituitary hormone (LER 960) with a molecular weight of about 30 000, while "big" LH appeared in an elution volume consistent with a molecular weight range between 140 000 and 180 000. Concordance was seen between the LH-activities measured in all three assay systems. The RRA/RIA ratio varied between 1.6 and 8.9, the RRA/TPA ratio was close to unity. Treatment with 6 m urea and 0.1 % mercaptoethanol and also, exposure to different pH values and salt concentrations did not change the elution position of the two LH components. Also, "big" and "little" LH appeared unaltered after re-filtration and no conversion each other could be found. In another experiment injection of gonadotrophin releasing hormone (Gn-RH) into a male induced a profound shift of LH towards the low molecular weight species. Kinetic uptake studies with "big" and "little" LH using RRA showed identical affinities to the receptor preparation. Ion exchange chromatography of serum, however, did not give two LH components, indicating no major differences in charge properties. This finding could be confirmed by preparative gel isoelectric focusing. The RRA potencies following gel filtration were in good agreement with that applied to the column, however, the immunological activities exceeded that of loaded by a factor 3–4. A new aspect of serum LH heterogeneity is the finding of a low molecular substance (mol. weight approximately 1000) in the outer dialysate of serum, which has LH like activity in all three assay systems.
THE THYROTROPHIN RECEPTOR IN HUMAN THYROID PLASMA MEMBRANES: EFFECT OF SERUM IMMUNOGLOBULINS
Authors: Bryson Janet M. , Joasoo Aet , Turtle John R. 
Published: December 2008

ABSTRACT
A homologous receptor assay system using human thyroid membranes and 125I-labelledhuman TSH (hTSH) was used to study the effect of serum and serum fractions on the binding of [125I]hTSH to the membrane. Scatchard analysis showed a single population of binding sites for TSH. Gamma globulin fractions prepared from sera of patients with Graves disease were able to displace [125I]hTSH from the membrane to a greater extent than normal gamma globulin in 21 out of 45 cases. Increased displacement activity was seen in patients with thyroiditis, hot nodules and euthyroid eye disease but not in patients with toxic multinodular goitres. Further fractionation of the gamma globulin fraction showed that the stimulatory activity was not confined to the IgG fraction. Scatchard plots showed gamma globulin fractions decreased the number of receptor sites available for TSH binding but did not alter the affinity of the receptor for TSH. IgG fractions showed different slopes and intercepts and appeared to decrease the affinity of the receptor for TSH. LATS activity in human serum may be explained on the basis of these observations on the properties of the TSH receptor.
AN INTER-LABORATORY COMPARISON OF TOTAL SERUM TRIIODOTHYRONINE DETERMINATION
Authors: Gordon Amirav , Gross Jack 
Published: December 2008

ABSTRACT
L-triiodothyronine (T3) standards and an unknown serum were prepared and distributed to 18 different laboratories. T3 was determined on the standards and both T3 and T4 were assayed on the serum. The T3 and T4 results varied widely with a mean variance of 36 and 23%, respectively. There was, however, a positive correlation between the T3 values obtained within each laboratory and results of the unknown serum. Thus, while the data of each laboratory is internally consistent, the data between laboratories cannot be compared without an appropriate reference sera. From this fact, it is concluded that absolute ("true") T3 concentrations in human serum is not yet known.
Because of the small number of laboratories involved in this comparison, it was not possible to determine which factors of the various procedures are responsible for the variance of the T3 results.
THE INSULIN RECEPTOR IN NORMAL AND OBESE PERSONS
Authors: Beck-Nielsen Henning , Pedersen Oluf , Bagger Jens Peder , Sørensen Niels Schwartz 
Published: December 2008

ABSTRACT
Using [125I]insulin at 172 pmol/l (1 ng/ml) the binding of insulin to mononuclear leucocytes isolated from peripheral blood was studied.
Our present study comprised 21 healthy subjects (22–33 years old, 90–110% of ideal weight) and a comparable group of 22 obese subjects (20–37 years old, minimum 150% of ideal weight). A significant difference in insulin binding was found between the two groups, the mean specific insulin binding fraction in normals being 1.92 ± 0.58 (s) × 10−2 and that for the obese 1.19 ± 0.41 (s) × 10−2 (P < 0.01).
No correlation was found between body weight and the number of insulin receptors in the obese subjects. However, the number of insulin receptors was negatively correlated to fat cell size (P < 0.05). Insulin receptors in subjects were also negatively correlated to fasting plasma insulin (P < 0.05).
Insulin receptors were studied in 11 obese subjects before and after 10 days of fasting. A significant increase in the number of insulin receptors was observed with a simultaneous decrease in plasma insulin to normal values.
The results indicate that obesity complicated by hyperinsulinism is associated with a decrease in the number of insulin receptors compared with the normal. This finding may in part explain the decreased insulin sensitivity of the hyperinsulinaemic obese.
CYANOKETONE-INDUCED INHIBITION OF ADRENAL 3β-HYDROXY-Δ5-STEROID OXIDOREDUCTASE ACTIVITY IN FEMALE AND MALE RATS IN VITRO
Authors: Gustafsson Sven A. 
Published: December 2008

ABSTRACT
The inhibition of adrenal 3β-hydroxy-Δ5-steroid oxidoreductase activity was studied in vitro 24 h after a single injection of 2α-cyano-4,4,17α-trimethyl-5-androsten-17β-ol-3-one (cyanoketone) to adult castrated female and male rats. The inhibition of conversion of dehydroepiandrosterone1) to androstenedione was about 80 % as compared to adult castrated control rats treated with vehicle only. The conversion of pregnenolone to progesterone and 5α-pregnane-3,20-dione was also inhibited by about 80 % in both sexes. The activity of 3β-hydroxy-Δ5-steroid oxidoreductase was greater both in cyanoketone-treated and control female rats as compared to the corresponding male rats. It is concluded that the previously observed sex differences in response to cyanoketone in vivo are not due to a lower affinity of male adrenal 3β-hydroxy-Δ5-steroid oxidoreductase to cyanoketone.
MAMMOTROPHIC ACTIVITY IN RAT SERUM DURING THE OESTROUS CYCLE, PREGNANCY AND LACTATION
Authors: Peters J. M. , Uyldert I. E. , Ariëns A. Th. 
Published: December 2008

ABSTRACT
The mammotrophic activity of various serum samples was assessed on the mammary gland of pregnant rats, in organ culture. Insulin was added to the medium. Serum samples from virgin rats showed little activity, and variation in mammotrophic activity during the oestrous cycle was slight. During pregnancy a significant increase in proliferative activity was not seen during the first week, but around day 8–9 mammotrophic activity increased sharply. The activity showed maxima around days 12 and 19. A decrease in the activity between these maxima was not consistently observed. Mammotrophic activity was still present in sera collected during parturition, and 30 min after parturition. It had disappeared completely within 24 h. The mammotrophic factor detectable by organ culture in the serum of pregnant rats could be rat chorionic mammotrophin.
Activity in the serum on day 0 and 1 of lactation was comparable to that of virgin rats, but some activity appeared on day 2. High activities were found frequently around day 4 to 6 of lactation. On other days the activity showed fluctuations without a definite pattern.
Litter size was of minor importance but the combination of a large litter size and fasting-overnight seemed to suppress the presence of mammotrophic activity in the serum. Nursing was important: after weaning the activity has disappeared, while renewed nursing after weaning resulted in the appearance of high levels of activity. The mitotic activity obtained with lactating rat serum in the culture was suppressed by addition of rabbit anti-rat prolactin serum to the medium. This suggests that the main mammotrophic factor detectable by organ culture in the serum of lactating rats, is prolactin.
INFLUENCE OF THE FOETUS, PLACENTA AND OVARY ON THE MAMMOTROPHIC ACTIVITY OF PREGNANT RAT SERUM
Authors: Peters J. M. , van Marie J. 
Published: December 2008

ABSTRACT
Serum mammotrophic activity was assayed using an organ culture technique with histological endpoints. Using sera of 13 days pregnant rats with 1 to 18 conceptuses, activity was detectable even in the presence of 1 conceptus, but the activity with 1–4 conceptus(es) tended to be less than with 6–18. Serum of rats with 1–3 conceptus(es) was approximately 2–4 times less active than serum of rats with 14 conceptuses. Removal of the conceptuses on day 15 caused loss of mammotrophic activity of the serum, tested 4 days later. When the foetuses, the ovaries or both the foetuses and ovaries were removed on day 15 of pregnancy, mammotrophic activity was present in the serum collected 4 days later. Differences in activity between the treated groups were small. The mammotrophic activity was comparable to the activity of serum of untreated 15 days pregnant rats or 19 days sham-operated pregnant rats.
Explanted single fragments of a 19 days pregnant rat placenta released activity into the medium. The placenta retained this capacity even when the foetus had been removed 4 days previously.
EFFECTS OF TESTOSTERONE ON GONADOTROPHIN RESPONSES TO SYNTHETIC LH AND FSH RELEASING HORMONE (LRH) IN NORMAL MEN
Authors: Robyn C. , L'Hermite M. , Leclercq R. , Copinschi G. 
Published: December 2008

ABSTRACT
LRH tests were performed in 6 adult men with intravenous injections of 25 μg, before and one week after an intramuscular injection of 250 mg testosterone oenanthate (Testoviron Depot®). One week after intramuscular injection of Testoviron the tonic secretion of LH was completely suppressed, but the reactivity or the reserve capacity of LH secretion, as tested by LRH, remained unchanged. In contrast, the tonic secretion of FSH and the reactivity of FSH secretion to LRH were both partly suppressed. Three months after the Testoviron injection, the basal levels of LH were still significantly lower than the control values, but the basal levels of FSH were identical to the control values. These data indicate that, in man, the feedback action of testosterone on gonadotrophin secretion could be exerted, at least for LH, at the hypothalamic level rather than at the pituitary level.
No significant effects of LRH were noted on the circulating levels of growth hormone and sugar. There was a distinct rise in serum prolactin, which was occasionally significant, within 30 min after LRH injection; this is considered to be without physiological significance.
DIURNAL VARIATIONS OF PLASMA AND PITUITARY THYROTROPHIN IN ADULT MALE AND FEMALE RATS
Authors: Jolín Trinidad , Pallardo Luis F. , Pericás Isabel 
Published: December 2008

ABSTRACT
Male and female rats fed a low iodine diet for 20 days were used to study the diurnal variations in resting levels of plasma and pituitary TSH concentration using a highly sensitive radioimmunoassay. Sex differences in the fluctuations in plasma TSH levels and in amount of TSH in the pituitary gland were observed. The daily fluctuations of plasma TSH were characterized by two peaks that occurred in males at 6 a. m. and at 3 p. m., while in females the peaks were delayed until 9 a. m. and 7:30 p. m. Moreover, in the females the morning and the afternoon peaks were of the same intensity while in the males the afternoon peak that occurred just before the onset of darkness was much greater than the morning peak. There was a fall in TSH content of the pituitary in the male rats at 6 a. m. and also in the afternoon just before the onset of darkness. Thus, the diurnal variations in the plasma and pituitary TSH levels were related in male rats. In the females, however, the pituitary TSH concentration did not reflect the changes observed in the plasma TSH levels. The level of plasma PBI did not appear to be responsible for the fluctuations in plasma TSH concentration. It is suggested that the main mechanism for the control of the circadian rhythm of TSH might be related to a high activity at night.