bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of endurance training on serum triiodothyronine kinetics in man: physical conditioning marked by enhanced thyroid hormone metabolism*
Authors: Rone James K. , Dons Robert F. , Reed H. Lester 
Published: March 2008

OBJECTIVE We studied the relationship between endurance training, aerobic capacity, and T3 metabolism in healthy euthyroid men.DESIGN T3 kinetic studies performed on two groups of subjects differentiated on the basis of physical activity status and aerobic capacity.SUBJECTS Five endurance‐trained athletes and five sedentary controls (mean±SD Vo2 max = 48.2 ± 7.1 vs 23.2±4.5 ml/kg/min, respectively) matched for age, body surface area, lean body mass, and baseline thyroid function.MEASUREMENTS Kinetic analysis performed using serial serum T3 levels measured following oral T3 administration. Metabolic clearance rate, total volume of distribution, disposal rate, and total body pool calculated using non‐compartmental analysis.RESULTS When normalized for lean body mass, all kinetic parameters were 25–38% greater in the athletic group compared to controls (P <0.05). Total volume of distribution, disposal rate, and total body pool were positively correlated with aerobic capacity (r=+0.69 to +0.79; P <0.05). Metabolic clearance rate was positively correlated to a non‐significant degree.CONCLUSIONS These results confirm the findings of prior studies that thyroid hormone metabolism is altered by physical conditioning. In addition, we demonstrated a positive correlation between aerobic capacity and several parameters of T3 kinetics. Differences in absolute lean body mass cannot explain these findings; rather it appears that there is something qualitatively different in the way endurance‐trained tissue processes thyroid hormone, compared to untrained tissue. The study was not designed to elucidate these differences at the cellular level; however, it does support a link between muscle physiology and T3 activity and may suggest a physiological role for thyroid hormone in physical conditioning.
High affinity growth hormone binding protein in plasma of patients with acromegaly and the effect of octreotide treatment
Authors: Roelen C. A. M. , Donker G. H. , Thijssen J. H. H. , Koppeschaar H. P. F. , Blankenstein M. A. 
Published: March 2008

OBJECTIVE The objective of this study was to investigate the effect of plasma GH‐levels on the high affinity growth hormone bindng protein (GHBP).PATIENTS We studied plasma samples of eight patients with acromegaly and eight age and sex matched healthy subjects.DESIGN Patients with acromegaly were treated with octreotide administered by continuous subcutaneous infusion. Levels of growth hormone binding protein (GHBP) were measured in plasma samples before therapy and 3, 6 and 12 months after starting treatment. During this period, octreotide was administered in doses of 300–800 μg/day. The mean dose per patient over the study period ranged from 300 to 575 μg/24 h. The GHBP levels of patients with acromegaly were compared with those in the healthy subjects.MEASUREMENTS Bound and free 125I‐GH in plasma were measured using FPLC gel chromatography on a Superose 12 column, after an overnight incubation period. The binding data were used for a Scatchard plot analysis. Wilcoxon's signed rank test was used for statistical analysis.RESULTS We found lower GHBP levels in acromegalic patients (P= 0.01) than in the control subjects. Octreotide treatment resulted in IGF‐I levels <300 μg/l in four patients. In these patients GHBP levels increased.CONCLUSIONS We conclude that growth hormone binding protein levels are down regulated in acromegaly, indicating an important role for GH in the regulation of this protein.
Thyroid function and thyroid autoimmunity independently modulate serum concentration of soluble interleukin 2 (IL‐2) receptor (sIL‐2R) in thyroid diseases
Authors: Marlottl S. , Caturegll P. , Barbesino G. , Marinò M. , Del Prete G. F. , Chlovato L. , Tonacchera M. , De Carll M. , Pinchers A. 
Published: March 2008

The serum concentration of soluble interleukin‐2 receptor (sIL‐2R) is a marker of T‐lymphocyte activation. Increased circulating sIL‐2R has been reported in untreated Graves' disease. This finding has been interpreted as the consequence of the autoimmune activation, but recent data suggest that sIL‐2R is directly correlated to thyroid state. The aim of this study was to elucidate the respective roles of autoimmunity and thyroid function in modulating serum sIL‐2R.DESIGN AND PATIENTS sIL‐2R was evaluated in 20 normal euthyroid subjects and in a large series of patients with autoimmune and non‐autoimmune thyroid disorders in different functional state.MEASUREMENTS sIL‐2R was assayed by a solid‐phase monoclonal antibody assisted ELISA method.RESULTS Serum sIL‐2R in normals was 461 ± 186 U/ml (mean ± SD). Increased sIL‐2R was found in 61 hyperthyroid patients with Graves' disease (1610 ± 962 U/ml, P <0.0001) and in 23 with toxic adenoma (1121 ± 598 U/ml, P <0.0001). Restoration of euthyroidism lowered to normal sIL‐2R in both groups. Serum sIL‐2R was higher in euthyroid Graves' disease patients with active than in those with non‐active ophthalmopathy. Decreased serum sIL‐2R (228 ± 93 U/ml, P <0.0001) was found in 30 patients hypothyroid after total thyroidectomy. Highly variable circulating sIL‐2R (range 100–1456 U/ml, mean ± SD: 379 ± 301 U/ml) was found in 49 patients with hypothyroid Hashimoto's thyroiditis (P= NS vs normals; P <0.02 vs post‐thyroldectomy hypothyroid patients). Treatment with L‐thyroxine increased sIL‐2R in all thyroldectomized and in the majority of Hashimoto's thyroidltis patients. In individual Hashimoto's thyroiditis patients (mostly with increased serum sIL‐2R), L‐thyroxine caused a decrease of circulating sIL‐2R. sIL‐2R was normal in 29 patients with euthyroid Hashimoto's thyroiditis. Both in Graves' disease and in Hashimoto's thyroiditis, no correlation was found between sIL‐2R and anti‐thyroglobulin, anti‐thyroid peroxidase and anti‐thyrotrophin‐receptor autoantibodies. Highly significant positive correlation between serum thyroid hormones and sIL‐2R was found in all study groups.CONCLUSIONS In thyroid disorders thyroid hormones are the main regulator of serum sIL‐2R concentration. The contribution of autoimmune activation may be detected only in some patients with autoimmune hypothyroidism, while in Graves' disease the role of the immune system is masked by the hyperthyroid state.
Body composition and bone mass in post‐menopausal women
Authors: Compston J. E. , Bhambhanl M. , Laskey M. A. , Murphy S. , Khaw K. T. 
Published: March 2008

OBJECTIVE We aimed to assess total body composition and to study the Interrelationships between fat and lean tissue mass with total and regional bone mass in healthy British post‐menopausal women.DESIGN AND PATIENTS Total body composition and regional bone mass were measured in 97 healthy post‐menopausal women recruited from the general community. The mean age was 57.9 years, range 49–65.MEASUREMENTS Total body composition (fat, lean tissue and bone mineral) and regional bone density in the lumbar spine and femur were measured by dual energy X‐ray absorptiometry on a Lunar DPX.RESULTS Significant negative correlations with age were found for total body bone mineral density (r= ‐0.200, P= 0.049), and lumbar spine bone mineral density (r= ‐ 0.28, P= 0.006); the calculated rate of bone loss from these two sites was 0.33 and 0.7% per annum respectively. Fat tissue mass showed a positive correlation with age (r= 0.22, P= 0.03). High correlations were observed between total body and regional bone mineral density (r= 0.755–0.829, P <0.001). After adjustment for age and lean mass, statistically significant correlations were seen between fat tissue mass and all bone mass measurements (P < 0.01–0.001), the strongest correlations being found for total body bone mineral content and density (r=0.477 and 0.488 respectively). Lean tissue mass showed a strong correlation with total body bone mineral content (r= 0.580, P <0.001), after adjustment for age and fat mass; It was less strongly correlated with other bone mass measurements than fat mass, showing only weak correlations with total body, trochanterlc and lumbar spine bone mineral density (r= 0.228–0.246, P <0.05). Age‐adjusted body weight showed stronger correlations with total and regional bone mass than did either body mass index or height.CONCLUSIONS Both fat and lean tissue mass are related to total and regional bone mass in post‐menopausal women, the relationship being strongest for fat mass. Body weight shows stronger correlations with bone mass than either height or body mass index. In view of the direction and magnitude of changes in fat, lean tissue and bone mineral after the menopause, adiposity and muscularity are more likely to be determinants of peak bone mass than of the rate of post‐menopausal bone loss.
Growth hormone treatment of adults withgrowth hormone deficiency: results of a 13‐month placebo controlled cross‐over study
Authors: Whitehead Helen M. , Boreham Colin , Mcllrath Edwin M. , Sheridan Brian , Kennedy Laurence , Atkinson A. Brew , Madden David R. 
Published: March 2008

Summary objective We aimed to study the effect of biosynthetlc growth hormone (GH) replacement In growth hormone deficient adults. design We performed a double‐blind placebo‐controlledcross‐over study of 6 months biosynthetic GH, replacement and 6 months placebo separated by a 1‐month'swashout period. patients Fourteen growth hormone deficient adults were studied. measurements We measured total body weight, percentage fat mass, lean body mass, muscle volume, exercise capacity, maximum oxygen consumption, muscle strength, bone mineral content, a number of biochemical parameters, IGF‐I, GH antibodies andpsychological well‐being. results Total body weight remained unchanged, but lean body mass increased (before GH mean ± SEM 49·8±5·5, after 53·4±5·6 kg; placebo before 51·2±5·4, after 50·4±5·1 kg; P < 0·05 and fat mass decreased (before GH 21·5±4·1, after 19·3±4·3, placebo before 19·3±4·0, after 22·5±4·5 kg; p < 0·05). Thigh muscle volume increased: (before GH 94·1±7·7, after 99·5±8·4 ml; placebo before 99·3±8·6, after 95·4±7·8 ml/0·8 mm computerized tomographic slice; P < 0·05). Exercise capacity increased (before GH 174·15, after 199·18·9 watts; placebo before 162·5±2·3, after 154·19·8 watts; P < 0·05), as did maximum oxygen consumption (before GH 1·93±0·2, after 2·17±0·2 I/m; placebo before 1·92±0·3, after 1·98±0·2 I/m; P < 0·05). There was no change in quadriceps muscle strength. Alkaline phosphatase increased (before GH 87·5 (32–158), after 106·0 (49–179) U/l; placebo 98·5 (50–145), after 72·0 (40–111) U/l; P < 0·05) without a change in the spinal bone density. IGF‐I increased (before GH 62 (36–97), after 216 (62–362) μg/l; placebo before 59 (52–112), after 60·5 (38–94) μg/l; P < 0·05). Carbohydrate tolerance remained unchanged as did fasting lipids, serum sodium, potassium, urea, calcium, phosphate and liver transaminases. Psychological well‐being remained unchanged. No growth hormone antibodies were detected before or after GH treatment. conclusions GH alters the body composition of growthhormone deficient adults and leads to improved exercisecapacity; alkaline phosphatase activity increases butwithout a change in spinal bone density, and carbohydratetolerance remains unaltered.
Physiological oestradiol administration does not change the biological to immunological ratio of LH in serum from post‐menopausal women
Authors: Buckler H. M. , Rothwell C. , Holds S. , Robertson W. R. 
Published: March 2008

SummaryOBJECTIVE We Investigated the effect of chronic physiological concentrations of oestradiol on the bioactivity (B) and immunoactivity (I) of LH in serum using radioimmunoassay (RIA) and a sensitive Immunoradlometrlc (IRMA) assay.DESIGN Twelve post‐menopausal, hysterectomized women received a 50‐mg subcutaneous E2 Implant, in the absence of progestogen treatment. Pretreatment serum samples were obtained on two occasions for measurement of E2and FSH by radioimmunoassay and for measurement of LH by bioassay (BIO), immunoradio‐metric assay and radioimmunoassay. Further serum samples were obtained monthly for 6 months for assay as above.RESULTS The serum E2level (basal levels< 70 pmol/l) rose following implant (P<0.01) peaking at 1 month (mean 454, range 356–580 pmol/l) and remaining within premenopausal physiological levels for 6 months. There were falls in FSH, LH‐RIA, LH‐IRMA and LH‐BIO (P< 0.001). There was no change in the B:I ratio for B:I‐RIA or B:I‐IRMA for LH which were 1.8 and 3.3, respectively pretreatment and 1.7 and 2.9 after 1 month's treatment.CONCLUSION The treatment of post‐menopausal women with 50‐mg E2subcutaneous implants produces physiological premenopausal E2levels for at least 6 months. There is no change In the B:I ratio of LH using either the RIA or IRMA during chronic E2 treatment.
Phaeochromocytoma in multiple endocrine neoplasia type 2 A: survey of 100 cases
Authors: Casanova S. , Rosenberg‐Bourgin M. , Farkast D. , Calmettes C. , Feingold N. , Heshmatl H. M. , Cohen R. , Conte‐Devolx B. , Guillausseau P. J. , Houdent C. , Bigorgne J. C. , Boiteau V. , Caron J. , Modigliani E. 
Published: March 2008

SummaryOBJECTIVE We report clinical, biochemical, morphological and histological data of phaeochromocytoma in 40 French families and in apparently sporadic cases of multiple endocrine neoplasia (MEN) type 2 A (medullary thyroid carcinoma, phaeochromocytoma, with or without hyperparathyroidism).DESIGN This retrospective study was obtained from cases registered by the‘Groupe d'Etudes des Tumeurs a Calcitonine’ from 1968 to 1990. We analysed the cases having sufficiently precise data on phaeochromocytoma with Pigas Software.PATIENTS Characteristics of phaeochromocytoma In 100 patients with MEN 2 A were reviewed. Phaeochromocytoma was bilateral in 51 %. The disease was inherited in 94 patients from 40 families (40 probands, 54 relatives), and was apparently sporadic In six.RESULTS In this series, diagnostic circumstances were highly suggestive of phaeochromocytoma in 39.8% of the cases, whereas in 43.2%, diagnosis was made through systematic investigations of patients, either before (27.3%) or after (13.6%) thyroidectomy, or after discovery of hyperparathyroidism (2.3%). Fifteen per cent of patients were detected by family screening. Sudden death occurred in 8.9%, malignant phaeochromocytoma In 3%, and ectopic tissue in 4% of the cases. Urinary metanephrines appeared to be the most sensitive screening test. The extent of clinical symptoms was not associated with a particular hormonal pattern. Bilateral adrenalectomy was performed in 60% (in one step in 50%, in two steps in 10%). In these patients, bilateral histological lesions were observed in 92.5%. Simultaneous diagnosis for adrenal and thyroid disease was made in 73.4%, but phaeochromocytoma may be diagnosed before (9.6%) or after (17%) medullary thyroid carcinoma, with an interval greater than 2 years in 25 cases.CONCLUSION Owing to variable clinical symptoms of phaeochromocytoma in these 100 cases of MEN 2 A, systemic biological adrenal assay is required. The search for phaeochromocytoma in medullary thyroid carcinoma (and vice versa) has to be systematically performed, even in apparently sporadic cases. Screening for phaeochromocytoma must be repeated for years, owing to the frequency of bilateral adrenal disease.
The International Standard for Thyroxine Binding Globulin
Authors: Bristow A. F. , Gaines‐Das R. E. , Buttress N. , Gallimore J. R. , Tennent G. A. , Pepys M. B. 
Published: March 2008

SummaryOBJECTIVE Thyroxine binding globulin is the major thyroid hormone binding and transport protein of the plasma, and its quantitative estimation is therefore of clinical importance. The objectives of the present study were to prepare and ampoule a preparation of thyroxine binding globulin suitable to serve as an international standard, to confirm the suitability of the preparation in a multi‐centre collaborative study, and to assign an ampoule content. DESIGN The collaborative study was designed with the following aims: (1) to compare the candidate preparation with local standards; (2) to calibrate the preparation with local standards and to confirm the assigned ampoule content; (3) to assess the stability of the ampouled preparation.MEASUREMENTS AND RESULTS Thyroxine binding globulin was purified by a combination of affinity and conventional chromatography. Analysis by gel electrophoresis, N‐terminal sequencing and electrospray mass spectroscopy showed the preparation to be ± 99% pure and to have a structure consistent with the known structure of thyroxine binding globulin. Thyroxine binding globulin assays performed in the multicentre collaborative study indicated that the preparation behaved as thyroxine binding globulin when compared to local standards and that the ampoule content was consistent with that assigned on the basis of physicochemical measurements of protein concentration.CONCLUSIONS The thyroxine binding globulin preparation coded 88/638 was established by the Expert Committee on Biological Standardization of the World Health Organization as the International Standard for Thyroxine Binding Globulin, 30.0 International Units per ampoule, with the additional information that for the preparation in 88/638, 1 IU is equivalent to 1 μg. The preparation is available from the National Institute for Biological Standards and Control.
The relationship between endogenous testosterone and gonadotrophin secretion
Authors: Bridges N. A. , Hindmarsh P. C. , Pringle P. J. , Matthews D. R. , Brook C. G. D. 
Published: March 2008

SummaryOBJECTIVE The secretion of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone in the adult male was studied by means of 48‐hour profiles. The aim of the study was to examine the effects of the endogenous circadian variation in serum testosterone concentration on LH pulsatility, and to determine the temporal relationships between FSH and LH, and between LH and testosterone by cross‐correlation, and the pulse frequency of these hormones by spectral analysis, as revealed by extended sampling periods.DESIGN Hormone profiles were obtained by 20‐minute sampling over 48 hours.SUBJECTS Six healthy adult males, aged between 21 and 23 years.MEASUREMENTS LH and FSH were measured using an immunoradiometric assay and testosterone with a solid‐phase radioimmunoassay.RESULTS The profiles showed pulsatile secretion of all three hormones, and a circadian rhythm with levels highest between 0200 and 0600 h. Cross‐correlation analysis There was a significant relationship between LH and FSH (r= 0.5; P=0.001) at 0 minutes (i.e. no time lag). A pulse of testosterone followed on average 60 minutes after a pulse of LH (r= 0.28; P= 0.001). Fourier transformation Spectral analysis showed the dominant period for LH and FSH pulsatility to be 200 minutes. The dominant period for testosterone pulsatility was 400 minutes. The effect of endogenous variations in serum testosterone concentrations The LH profiles were divided into periods when the serum testosterone concentration was high or low, and Fourier transformation carried out on these shorter periods. These transforms showed that the dominant period during high serum testosterone concentration was 180 minutes, and during low serum testosterone was 120 minutes (P ± 0.025).CONCLUSIONS FSH and LH are co‐secreted, and a pulse of testosterone follows a pulse of LH by 60 minutes. The physiological changes in serum testosterone concentration that occur during the day result in changes in the pulse frequency of LH. Testosterone concentrations thus have rapidly acting feedback activity at hypothalamic level.
The relationship between hCG and relaxin secretion in normal pregnancies vs peri‐implantation spontaneous abortions1
Authors: Stewart Dennis R. , Overstreet James W. , Celniker Abbie C. , Hess David L. , Cragun Jeffry R. , Boyers Stephen P. , Lasley Bill L. 
Published: March 2008

SummaryOBJECTIVE We determined the ovarian response to human chorionic gonadotrophin (hCG) in terms of relaxin and progesterone secretion during the peri‐implantation period of normal and failing pregnancies. We wished to test the hypotheses that relaxin production in failing pregnancies is different from that in normal pregnancies, that relaxin is a reliable, quantitative indicator of the biological activity of endogenous hCG, and that relaxin is a useful predictor of peri‐implantation spontaneous abortions.DESIGN Daily blood samples were collected in a prospective longitudinal study from insemination patients.PATIENTS Women undergoing artificial insemination in natural cycles with non‐frozen donor semen at a University clinic.MEASUREMENTS Serum LH, hCG, relaxin and progesterone were measured and the relationship between hCG and the ovarian hormones was evaluated in the peri‐implantation period of normal pregnancies and spontaneous abortions.RESULTS Nine of 23 conceptive cycles resulted in a spontaneous abortion between 16 and 70 days after the LH peak. In all normal and failing pregnancies there was a close qualitative relationship between hCG secretion and relaxin production. Six of nine failing pregnancies were associated with abnormally low hCG secretion. Six of the spontaneous abortions were associated with rates of relaxin secretion which were higher than the mean of 14 normal pregnancies. No such alterations in progesterone concentrations were observed. In cases where hCG was extremely low, the quantitative relationship between hCG and relaxin was different from that in cases of normal hCG concentrations.CONCLUSIONS There is a close temporal relationship between the secretion of trophoblastic hCG and ovarian secretion of relaxin in the peri‐implantation period of normal and failing pregnancies. In failing pregnancies there is substantial variability in the quantitative relationship between relaxin and hCG, indicating that relaxin is not a reliable quantitative indicator of hCG bioactivity. Contrary to previous reports, relaxin concentrations in failing pregnancies tended to be higher than or equal to concentrations in normal pregnancies until the loss was imminent. Because of this relaxin is not a useful predictor of peri‐implantation spontaneous abortions.