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Multiple scattering tomography

Multiple scattering represents a challenge for numerous modern tomographic imaging techniques. In this Letter, we derive an appropriate line integral that allows for the tomographic reconstruction of angular resolved scattering distributions, even in the presence of multiple scattering. The line integral is applicable to a wide range of imaging techniques utilizing various kinds of probes. Here, w

Serum levels of insulin-like growth factor I and insulin-like growth factor-binding protein 1 correlate with serum free testosterone and sex hormone binding globulin levels in healthy young and middle-aged men

OBJECTIVE: Administration of testosterone has been reported to increase serum levels of IGF-I in men with isolated hypogonadotrophic hypogonadism. An inverse relation between serum IGF-I and sex hormone binding globulin (SHBG) is seen in GH deficient children. The biological action of IGF-I is thought to be influenced by binding proteins, one of which is insulin-like growth factor-binding protein-

Quality of life in adults with growth hormone (GH) deficiency : response to treatment with recombinant human GH in a placebo-controlled 21-month trial

We examined the effect of GH supplementation on the psychological capacity and sense of well-being in 36 patients with adult-onset GH deficiency (GHD). Recombinant human GH was given in a 21-month cross-over, double blind trial, and quality of life was assessed by using three self-rating questionnaires: the Hopkins Symptom Check List (HSCL), the Nottingham Health Profile (NHP), and the Psychologic

Decreased serum testosterone and free triiodothyronine levels in healthy middle-aged men indicate an age effect at the pituitary level

In an attempt to study further the age-specific influence on the hypothalamo-pituitary-gonadal axis as well as the hypothalamo-pituitary-thyroid axis, we have now investigated young and middle-aged men, considering possible confounding factors. Both serum total testosterone, free testosterone and the total ratio of testosterone to sex-hormone binding globulin were significantly lower among middle-

Effect of acute desmopressin and of long-term thyroxine replacement on haemostasis in hypothyroidism

OBJECTIVE: Hypothyroidism can be complicated by bleeding symptoms such as easy bruising, menorrhagia and sometimes even a severe bleeding tendency with fatal outcome. Usually there is a prolonged bleeding time, or a low plasma concentration of coagulation factor VIII (FVIII) or von Willebrand factor (vWF). The aim of the present study was to investigate the acute haemostatic effect of desmopressin

Serum selenium concentrations in patients with autoimmune thyroiditis and non-toxic nodular goiter

Selenium (Se) deficiency is said to contribute to the atrophy of the thyroid gland in certain endemic goiter areas in Africa. To test the hypothesis that, a low Se intake could protect against goiter development in autoimmune thyroiditis, we analysed the Se concentration in 20 patients with the atrophic variant of lymphocytic thyroiditis, 23 patients with Hashimoto's thyroiditis and 23 patients wi

Contractions of English semi-modals : the emancipating effect of frequency

GERMAN SUMMARY: Gegenstand dieser Arbeit sind die verkürzten Formen (Kontraktionen) der englischen Modalausdrücke (‘semi-modals’) 'BE going to', 'HAVE got to' und 'want to'. Die Kontraktionen sind in der gesprochenen Sprache häufig und zeigen sich in den Schreibweisen 'gonna', 'gotta' und 'wanna'. Sie werden im Nordamerikanischen Englisch untersucht. Den Hintergrund der Arbeit bildet die GrammThe current restructuring of the English modal system has long been noted as an ongoing language change process. Semi-modal constructions such as 'BE going to' and 'HAVE got to' are textbook cases of grammaticalization. As grammaticalization comes with a rise in frequency, these semi-modals are also typical examples of the ‘reducing effect’ of frequency, which leads to the contracted forms 'gonna'

Increased prevalence of thyroid peroxidase antibodies (TPO-Ab) in women with glomerulonephritis

In a cross-sectional study adjusting for age, gender, and catchment area, the prevalence of thyroid antibodies was assessed in 51 consecutive subjects with biopsy-proven glomerulonephritis and in 112 control subjects admitted for extracorporeal shock-wave lithotripsy treatment for renal stones. Women with glomerulonephritis had both a significantly greater prevalence of thyroid peroxidase antibodi

Effects of adrenal function tests on the levels of endogenous digitalis-like substances and some pituitary hormones

In order to study the influence of the hypothalamic-pituitary-adrenal axis on the levels of endogenous digitalis-like substances (EDLS) in plasma and urine, eight healthy subjects (25-40 years old) were given dexamethasone 1 mg orally and tetracosactide (an ACTH analog) 0.25 mg i.v., on separate occasions. The circulating levels of EDLS, TSH, PRL and AVP following administration of either test dru

Immunoreactive endogenous digoxin-like substances : plasma levels are dependent on the hypothalamic-pituitary-adrenal axis for release and on kidney function for elimination

To identify factors that regulate the levels of immunoreactive digitalis-like substances (irEDLS) in body fluids, two studies were carried out. Plasma and urine levels of irEDLS were measured in uremic and normal subjects. Extracted material was fractionated (12 fractions) and assayed by digoxin radioimmunoassay. In four fractions, higher levels of irEDLS were found in uremic than in normal plasma

The role of estrogen in the TSH and prolactin responses to thyrotropin-releasing hormone in postmenopausal as compared to premenopausal women

The basal and TRH (Thyrotropin-Releasing Hormone) stimulated TSH (Thyrotropin) and PRL (Prolactin) responses (incremental area; IA) to 200 micrograms TRH was studied in 13 pre- and 13 postmenopausal women of 60 years of age. Both groups consisted of healthy women, none had goiter and all were negative for thyroid autoantibodies. The serum levels of TSH, T3, T4 and SHBG (sex hormone-binding globuli

Neuroendocrine effects in printing workers exposed to toluene

The effect of exposure to toluene on plasma concentrations of testosterone, prolactin, luteinising (LH) and follicle stimulating (FSH) hormones was investigated in 47 rotogravure printers (time weighted average air toluene below 80 ppm; blood toluene concentration post-shift 0.19-7.99 mumol/l) and compared with a reference group. Increasing exposure concentrations of toluene (concentrations less t

Hormone status in occupational toluene exposure

Twenty toluene-exposed rotogravure printers, without signs of solvent-induced toxic encephalopathy, had lower median plasma levels of follicle stimulating hormone (FSH) (3.2 vs. 4.9 IU/L; p = .02) and luteinizing hormone (LH) (6.4 vs. 7.2 IU/L; p = .05) and also lower serum levels of free testosterone (7.8 vs. 86.8 pmol/L; p = .05), respectively, than 44 unexposed referents. The individual time-we

The blunting of the thyrotropin response to repeated thyrotropin-releasing hormone administration is reduced by dopaminergic blockade both at normal and elevated serum levels of thyroid hormones

Fifteen premenopausal women were investigated in the follicular phase of the menstrual cycle with two TRH tests within an interval of 48 to 96 h. Ninety min before each TRH test either 10 mg metoclopramide or saline was injected iv in randomized order. The same procedure was repeated in the following menstrual cycle after pretreatment with T4 (0.5 mg daily for 6-14 days). At least 2 months later t

Normal pituitary hormone response to thyrotrophin and gonadotrophin releasing hormones in subjects exposed to elemental mercury vapour

Exposure to elemental mercury (Hg) vapour results in an accumulation of Hg in the pituitary, the thyroid, and the testis. In this study, basal serum concentrations of pituitary hormones (thyrotrophin (TSH), prolactin (PRL), follicle stimulating hormone (FSH), and luteinising hormone (LH] or their response after administration of thyrotrophin and gonadotrophin releasing hormones did not differ betw

Plasma neuropeptides in hyperthyroidism

Plasma levels of the neuropeptides, vasoactive intestinal polypeptide (VIP, neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), substance P, and galanin were determined in 15 hyperthyroid patients before and at 3 occassions during 38 weeks of treatment. Treatment was performed with either 131I alone or with carbimazole, with combination of carbimazole and thyroxine, or with subtotal thyr

Suppressed plasma prolactin response to thyrotropin-releasing hormone in hyperthyroidism reproduced by thyroxine but not by triiodothyronine administration to normal subjects

In 10 hyperthyroid women studied in the follicular phase of the menstrual cycle, basal plasma PRL was normal, but PRL release after TRH was significantly suppressed compared with that in 11 control women. The suppressed PRL response to TRH was not explained by changes in serum estradiol or sex hormone-binding globulin. It recovered after treatment of hyperthyroidism. When normal women were treated

Increased plasma gonadotropin levels in spontaneous hyperthyroidism reproduced by thyroxine but not by triiodothyronine administration to normal subjects

In nine hyperthyroid women studied in the follicular phase of the menstrual cycle basal plasma LH concentrations and LH and FSH responses to GnRH were increased compared to those in nine normal women. The increased gonadotropin levels could not be related to changes in body weight or plasma estradiol or serum sex hormone-binding globulin levels, and they approached normal levels during or after tr

Thyroid hormone metabolism in thyroid disease as reflected by the ratio of serum triiodothyronine to thyroxine

In 77 euthyroid subjects the mean ratio between serum triiodothyronine (S-T3) in nmol/l X 10(3) and serum thyroxine (S-T4) in nmol/l was 22.4 with a standard deviation of 4.3. The distribution of the ratio was close to Gaussian. It was not changed in subjects under estrogen effect. The ratio was increased in hypothyroid subjects suggesting a mechanism preserving S-T3 better than S-T4 in thyroid fa