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U Ranft

Publications and source records attributed to U Ranft.

34 records · Page 2Linked to original sources
PubMed1990

Physiological regulation of circadian and pulsatile thyrotropin secretion in normal man and woman.

The circadian and pulsatile TSH secretion profiles were investigated in 5 females at the time of menstruation and 21 healthy males by sampling blood every 10 min for 24 h. Computer-assisted analysis, i.e. the Cluster and Desade programs, revealed means of 9.9 +/- 1.7 (Cluster) and 11.4 +/- 3.9 (Desade) pulses/24 h. More than 50% of the TSH pulses were detected between 2000-0400 h. Male and female subjects showed no significant difference in the basal mean and pulsatile secretion of TSH or in the TSH response to TRH (200 micrograms). Repetition of the TSH secretion analysis in 4 healthy subjects after 1, 2, and 6 months (2 subjects) revealed a significantly better cross-correlation within than between individuals (P less than 0.0001). We modulate the circadian TSH secretion pattern by acute sleep withdrawal or prolonged sleep after a night of sleep withdrawal in six healthy male volunteers. Sleep withdrawal augmented the nightly TSH secretion (mean serum TSH, 2.1 +/- 1.3 mU/L; mean TSH in sleep, 1.3 +/- 0.5 mU/L; P less than 0.05), whereas sleep after sleep withdrawal almost completely suppressed the circadian variation (mean TSH, 1.1 +/- 0.7 mU/L; P less than 0.01). This modulation is due to a significant decrease in pulse amplitude, but not to an alteration in the frequency or temporal distribution of TSH pulses.

Adult↗
PubMed1990

Circadian and pulsatile TSH secretion under physiological and pathophysiological conditions.

In addition to the well known circadian rhythm of TSH secretion a pulsatile pattern of release has been shown. Analysis of the pulsatile release by different computer-assisted methods revealed systematic differences in the number and distribution of TSH pulses. Using the same approximation of false positive pulses (less than 1%) in any of the 21 healthy male volunteers tested a lower number of pulses was found by the Pulsar method (mean 5.1 +/- 2.0/24 h) than by the Cluster (10.6 +/- 1.8) or the DESADE program (13.6 +/- 4.6). The results of the Cluster and Desade analysis fit well to that of Fourier transformation which revealed a dominant frequency at 160 min. In addition dominant frequencies in comparison to a noise series were found at 24 h and at 33 min. Analysis of the data in 8 h segments between 2000 and 0400 h, 0400 and 1200 h and 1200 and 2000 h by Desade and cluster revealed that app. 50% of pulses occurred between 2000 and 0400 h, suggesting an important role of pulsatile TSH release in the generation of the circadian TSH rhythm. In 3 patients with TSH-induced hyperthyroidism the circadian and pulsatile pattern of TSH secretion was similar to that in healthy controls. In contrast, in a patient with a TSH producing pituitary tumor the circadian variation of TSH secretion was abolished. Patients with a non-toxic goitre revealed a significantly lower mean TSH serum level as the control group of healthy subjects. The number of TSH pulses was slightly but significantly lower when analyzed by the DESADE program but not when analyzed with any other method.

Adult↗
PubMed1989

Physiological regulation of thyrotropin.

The pattern of TSH secretion in man in pulsatile in addition to the well known circadian variation. The mechanism triggering TSH pulses remains unclear to date. Infusions of somatostatin or dopamine rapidly lowering basal TSH levels without suppressing the pulsatile pattern suggest that an episodic disinhibition exerted by a physiological inhibitor is not a likely cause. On the same basis, thyroid hormones do not appear to be candidates, since they similarly inhibit basal TSH levels after a time lag of several hours but again do not suppress pulsatile release of the hormone. In contrast, bolus injections of dexamethasone completely abolish pulsatile release of TSH for several hours despite a normal sensitivity of the pituitary to exogenous TRH, suggesting a hypothalamic action of the drug. The hypothesis that pulsatile TSH release might be governed by a pulsatile mode of a hypothalamic stimulator is supported by the observation that an infusion of nifedipine, a calcium channel blocker, which in vitro selectively inhibits the TRH effect on TSH but not prolactin secretion, exerts a comparable effect when it is infused in vivo.

Dopamine↗
PubMed1989

The role of glucocorticoids in the regulation of thyrotropin.

The potentially inhibitory action of endogenous or exogenous synthetic glucocorticoids on TSH secretion was investigated. Pulsatile and circadian TSH and cortisol rhythms were measured in healthy subjects (12 rhythms), but no correlation between the hormones could be detected. Acute stimulation of endogenous cortisol secretion by CRH tests (1 microgram/kg of ovine CRH) at 20.00 h in 9 healthy volunteers did not significantly alter the nightly increase in TSH. Chronic elevation of endogenous cortisol serum levels in patients with Cushing's disease revealed a heterogeneous pattern. In 2 patients serum TSH and thyroid hormone levels showed a normal 24-h rhythm, whereas the other 2 patients had low TSH serum levels. Acute treatment of 9 healthy volunteers with 0.5, 1 or 2 mg dexamethasone po at 23.00 h resulted in a significant dose-dependent suppression of mean basal TSH levels 9h later. Treatment with 30 mg of prednisone for 1 week in 7 patients with Crohn's disease did not influence basal TSH. The TSH response to TRH was only temporarily suppressed on day 3, but not on day 7 of treatment. The results suggest than under physiological conditions glucocorticoids have no regulatory influence on pulsatile and circadian TSH secretion.

Adult↗
PubMed1989

[The status of galvanic assessment of equilibrium].

The galvanic test is the only method of localising the site of the disease in the differential diagnosis between a vestibular endorgan or neuronal lesion. The galvanic nystagmus persists even after complete destruction of the inner ear but is impaired as soon as the peripheral vestibular neurone is damaged. We investigated 30 normal subjects, 10 patients with Menière's disease and 20 patients with an acoustic neuroma. The patients had a reduced caloric response on one side. All subjects were stimulated monaural-unipolar. The photoelectronystagmograms were analysed by determining slow phase velocity. For interpretation we used the "relationship of excitability" as described recently by Mulch and Scherer for the thermal test. This procedure seems to be more accurate than the calculation of side difference of excitability as a proportion of total reaction. Furthermore we suggest basing the evaluation of galvanic test by calculating expectation regions for the logarithmic values obtained by right-left stimulation. This method assumes a two dimensional symmetric normal distribution. The parameters lay within the normal range in all patients with Menière's disease whereas they were abnormal in every subject with an acoustic neuroma.

Adult↗
PubMed1987

Circadian and pulsatile thyrotropin secretion in euthyroid man under the influence of thyroid hormone and glucocorticoid administration.

The inhibitory action of thyroid hormones (TH) and glucocorticoids on circadian and pulsatile TSH secretion was investigated in groups of five normal men by sampling blood every 10 min for 24 h (start, 1750 h). Serum TSH was measured by a sensitive immunoradiometric assay. Continuous infusion of 50 micrograms T3 or 250 micrograms T4 for 8 h (1900-0300 h) significantly suppressed serum TSH levels (T3, P less than 0.025; T4, P less than 0.05; by paired t test). Administration of 3 g sodium ipodate 7 h before TH infusion did not alter the TSH response to T3, but T4-dependent suppression was abolished. Pulsatile TSH secretion [basally, 5.8 +/- 1.3 (+/- SD) pulses/24 h, as analyzed by the PULSAR program; 6.8 +/- 1.9 by the Cluster program] was not significantly altered by any of the experimental conditions. The additional finding of blunting of the TSH response to TRH after TH alone or ipodate and T3 suggests a predominantly pituitary feedback action of TH exerted via conversion of T4 to T3. In contrast, bolus injections of 4 mg dexamethasone (dex) at 1900 and 2200 h abolished TSH pulses for at least 6 h (PULSAR, 6.6 +/- 1.6 pulses/24 h basally vs. 3.6 +/- 3.0 under dex; Cluster, 7.0 +/- 2.7 pulses/24 h basally vs. 1.6 +/- 1.6 under dex). Dex administration also resulted in a prompt, sustained, and significant suppression of basal TSH (P less than 0.0005). Together with a normal serum TSH response to TRH (in separate experiments 1, 9, and 19 h after dex administration), these data suggest that glucocorticoid feedback occurs at a suprapituitary level.

Adult↗
PubMed1986

Pulsatile pattern of thyrotropin-release in normal men.

To evaluate the existence of a pulsatile secretion pattern of thyrotropin (TSH) the 24 h release profile of the hormone was investigated in 7 healthy male subjects by taking blood via an indwelling venous catheter at 10-min intervals. Thyrotropin levels were analysed with high precision by a recently developed immunoradiometric assay (IRMA) able to distinguish euthroid and hyperthyroid TSH-levels. Visual analysis (n = 10.4 peaks/24 h) and the computer assisted evaluation by the Santenprogramme (n = 9.9 peaks/24 h) as well as the Pulsar-programme (n = 7.7 peaks/24 h) revealed an episodic release pattern with a low amplitude of pulses. These preliminary results are highly suggestive of a pulsatile TSH secretion similar to other pituitary hormones.

Adult↗
PubMed1986

Thyrotropin--an episodically secreted hormone.

A recently developed highly sensitive immunoradiometric thyrotropin (TSH) assay capable to distinguish between euthyroid and hyperthyroid TSH-levels was used to evaluate the secretion-pattern of TSH in 10 healthy male subjects by taking blood via an indwelling venous catheter at 10 min intervals over 24 h. Visual analysis revealed a pulsatile pattern of hormone release with an average of 10.3 peaks/24 h. Evaluation by computer assisted programs such as the Santen-program (8.9 peaks/24 h, amplitude 0.60 mU TSH/l), the 'Pulsar'-program (6 peaks/24 h, amplitude 0.61 mU TSH/l) or power-spectrum analysis (11.9 peaks/24 h) showed similar results. These data suggest a pulsatile mechanism of TSH secretion similar to other pituitary hormones.

Adult↗
PubMed1984

[Chronic pancreatitis: sensitivity, specificity and predictive value of the pancreolauryl test].

Assessment of the clinical value of the pancreolauryl test (PLT) in the literature range from "useless" to a specifity of 95% and a sensitivity of 98%. In this work, our own data are presented in relation to various reference methods. The results are derived from the largest collective investigated to data, comprising 40 controls and 391 patients (108 with chronic pancreatitis and 283 with other gastrointestinal disorders). The specifity of the the PLT varies between 81% and 95% according to the "quality" of the control collective. The PLT is particularly frequently pathological in patients with diseases in the region of the gallbladder/bile duct and the gastrointestinal tract. The sensitivity of the PLT for chronic pancreatitis varies between 68% and 100%, depending on 9 different reference methods employed. Based on the prevalence of chronic pancreatitis with exocrine insufficiency in various patient collectives, the predictive value of the PLT for the presence of this disorder can be calculated using our data.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1981

[Differential diagnosis of chronic hepatitis. Active chronic hepatitis--chronic destructive cholangitis?].

Analysis of the enzyme pattern in 34 patients with liver histology indicating porto-periportal inflammation showed two statistically well differentiated groups: 20 patients with clinical suspicion of early chronic active hepatitis and 14 patients with suspected chronic destructive cholangitis. The course of the disease and the response to immunosuppressive treatment were quite different in the two groups. For differentiation of the early stages of chronic active hepatitis and chronic destructive cholangitis correct interpretation of the enzyme pattern is of great importance. It is also relevant for the decision to use long term immunosuppressive treatment.

Cholangitis↗
PubMed1980

[Immunosuppressive treatment of the early stages of active or inactive chronic hepatitis: results of a pilot study (author's transl)].

Immunosuppressive treatment with prednisolone and azathioprine was administered to a small group of nine patients in the early stage of chronic active or inactive hepatitis about six months after onset of the disease. There occurred a relatively rapid improvement in the active liver process, including biochemical and histological findings, compared with ten patients in a control group who, with the same liver condition, were not given immunosuppressive treatment. There were no side-effects in the treated group.

Azathioprine↗
PubMed1980

[Immunosuppressive treatment of chronic active hepatitis (author's transl)].

Early-stage chronic active hepatitis treated with prednisolone and azathioprine has a good prognosis. In most of the 20 patients investigated improvement occurred already after 3 months of treatment, by 6 to 9 months the laboratory findings had become normal and after 12 months there was no definite evidence histologically for the initial aggressive form of liver disease. However, in the late stage of chronic active hepatitis the effect of immunosuppressive treatment seems questionable. The tendency for improvement of laboratory findings during immunosuppression was significantly worse than in early-stage disease. Histologically there was no real improvement in two thirds of the cases a year after onset of treatment.

Azathioprine↗
PubMed1980

[Influence of (+)-cyanidanol-3 on the course of acute viral hepatitis (author's transl)].

A double-blind study was conducted in four hospitals to test the effect of (+)-cyanidanol-3 (Catergen) on the course of acute viral hepatitis. Activities of a number of enzymes, bilirubin levels and gamma-globulin concentrations, as well as elimination of HBs antigen in blood were measured serially in 73 patients with viral hepatitis, 37 being treated with the drug, 36 patients receiving a placebo. In addition, liver biopsies before and after treatment were compared (19 patients treated, 23 patients on placebo). There was no significant difference between the treatment and placebo groups with regards to morphological and biochemical changes.

Adolescent↗