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Biomedical subjects

F Waldhauser

Publications and source records attributed to F Waldhauser.

At least 37 records · Page 2Linked to original sources
PubMed1995

Lack of pineal growth during childhood.

During childhood, serum melatonin concentrations drop by approximately 80%, but the 24-h melatonin excretion is stable. Arrest of pineal growth after the end of infancy has been proposed as one possible mechanism underlying that phenomenon. To test this hypothesis, we reviewed 332 magnetic resonance imaging brain studies, classified as normal, of endocrine-normal children, aged 1 day to 15 yr, and estimated the pineal and pituitary sizes. The pineal was identified in 277 of 332 magnetic resonance imaging studies (83%). The average size (mean +/- SEM) of the pineal gland (transaxial diameter, 5.6 +/- 2.1; midsagittal diameter, 5.0 +/- 2.4; planimetric area, 28.5 +/- 17.8) did not differ with age. A total of 74 of 277 pineals with cysts (26.7%) were found. The occurrence of pineal cysts was equally distributed among the different age groups (chi 2 = 11.6; df = 14; P = 0.7). Ten pineals showed more than 1 cyst (3.6%). The pituitary was identified in 325 of 332 brain images (97.9%). The average pituitary size increased by some 100% from 1 to 15 yr of age [transaxial diameter: F = 2.2; P = 0.005 (by two-way analysis of variance); midsagittal diameter: F = 3.7; P = 0.0001; planimetric area: F = 7.1; P = 0.0001]. The pituitary was slightly larger in females than in males [midsagittal diameter: F = 8.8; P = 0.003 (by two-way analysis of variance); planimetric area: F = 7.9, P = 0.005]. The data presented indicate a lack of a discernible pineal growth after age 1 yr, which contrasts with pituitary development in the same individuals. The data are in agreement with a hypothesis suggesting a growth arrest of the pineal after infancy.

Adolescent↗
PubMed1995

[Long-term experiences with a long-acting gonadotropin releasing hormone analog in therapy of central precocious puberty: effect on body growth].

In central precocious puberty (CPP), characterised by premature but otherwise normal puberty, the early onset of the pubertal growth spurt with increased height velocity results in premature epiphyseal closure with reduced final height. We examined the growth pattern in 11 patients (9 girls and 2 boys) with CPP treated with a long-acting gonadotropin-releasing hormone analogue (GNRHa). Every 28 days 75 micrograms of the GNRHa Triptorelin (Decapeptyl CR, Fa. Ferring) per kg body weight are given intramuscularly. We observed body height, height velocity, bone maturation (dBA/dCA) and predicted adult height in these patients for up to 4 years. Before treatment body height was markedly elevated (2.5 +/- 4.4 SD above the age appropriate mean); after two years of therapy it reached the normal range. Height velocity decreased significantly within the first six months of treatment and remained subsequently low (F = 7.59; p < 0.0001). In the first year on treatment bone maturation (dBA/dCA) dropped from 1.8 +/- 0.42 to 0.7 +/ 0.27 and in the second year to its lowest value of 0.3 +/- 0.13 (F = 2.35; p < 0.05). The predicted adult height increased from 154.5 +/- 4.0 cm at the beginning of treatment to 160.3 +/- 3.9 cm at the most recent follow-up examination. The present data indicate that treatment with a long-acting GNRHa markedly affects body growth in CPP by reducing height velocity and delaying bone maturation. The predicted adult height appears to increase, consequently.

Adolescent↗
PubMed1995

Direct enzyme-linked immunosorbent assay and a radioimmunoassay for melatonin compared.

A novel commercially available ELISA for direct measurement of melatonin concentration in serum was evaluated and compared with an RIA routinely used in our laboratory. The direct ELISA is technically simpler, requires a smaller sample volume (0.1 mL), and compares well with RIA in terms of stability of the calibration curve and intra- and interassay CVs. Correlation with RIA measurements is, however, suboptimal (y = 0.39x + 56; r = 0.65, P < 0.001; n = 138), which may be due to a serum effect, as evidenced by dilution studies. Furthermore, the detection range of the ELISA does not cover the physiological daytime melatonin concentrations in humans. Adding an extraction and 10-fold concentration step shifted the detection range of the ELISA to include low physiological concentrations as well. Correlation with RIA measurements also improved significantly (y = 0.97x-23; r = 0.95, P < 0.001; n = 105), probably due to removal of the serum effect. Although extraction increases the required sample volume (1.5 mL), work load, and procedure time, this step is necessary for the ELISA to compete successfully with RIA.

Calibration↗
PubMed1993

Clinical aspects of the melatonin action: impact of development, aging, and puberty, involvement of melatonin in psychiatric disease and importance of neuroimmunoendocrine interactions.

During the last decade we have learned much on physiological changes in the secretion of the pineal hormone melatonin (MLT) in man. Reportedly, there is little or no MLT secreted before age 3 months. Then MLT production commences, becomes circadian, and reaches highest nocturnal levels at the age of 1-3 years. During all of childhood nocturnal peak levels drop progressively by 80% until adult levels are reached. This alteration appears to be the consequence of increasing body size in face of constant MLT production during childhood. The biological significance of this MLT alteration is presently unknown. Because of conceptual considerations, major depressive syndrome (MDS) and seasonal affective disorder (SAD) have been in the focus of pineal research for several years. Although in these disorders alterations in MLT levels could not be substantiated, light therapy, a consequence of this research, was discovered as an effective treatment for SAD and perhaps for MDS. In addition, there is some recent evidence for low MLT levels in schizophrenia. Finally, the potential effect of MLT in neuroimmunoendocrine interactions is presently explored. Reportedly, in vitro studies and animal experiments give evidence for a modulatory role of MLT in the immune response. However, the exact way of this possible action of MLT remains to be clarified. Clinical studies are too scant for a meaningful estimation of MLT's involvement in human neuroimmunoendocrine interactions.

Aging↗
PubMed1993

Circadian secretion pattern of melatonin in de novo parkinsonian patients: evidence for phase-shifting properties of l-dopa.

Aim of this study was the characterization of the circadian melatonin profile in de novo Parkinson patients (N = 9, age 60.0 +/- 3.2 years, mean +/- SEM) and the comparison of these profiles with those of controls and Parkinson patients treated with l-dopa/decarboxylase inhibitor (l-dopa/DCI). We collected 14 venous blood samples during a period of 24 hours and measured the serum melatonin levels by a radioimmuno assay. De novo Parkinson patients displayed the nocturnal melatonin peak (acrophase) at the same time as controls and significantly later than l-dopa/DCI treated patients (1:54 +/- 15.6 min [average clock time +/- SEM in minutes] vs. 1:45 +/- 15.6 min vs. 0:13 +/- 40.8 min). The amount of secreted melatonin did not differ among the three groups. Stage and duration of Parkinson's disease did not correlate with the amount of secreted melatonin. Patients of the tremor subgroup, however, secreted more melatonin than patients presenting only with rigidity and akinesia. The phase advance in Parkinson patients treated with l-dopa/DCI is possibly due to a central nervous dopaminergic effect elicited by l-dopa administration and not inherent to Parkinson's disease per se.

Aged↗
PubMed1993

The circadian melatonin and cortisol secretion pattern in permanent night shift workers.

In permanent night shift workers the impact of environmental time cues on the circadian system is conflicting. Rhythm adjustments to the nocturnal work schedule have been described, and their significance for tolerance to shift work is under discussion. Reports concerning the effect of this work situation on the setting of the endogenous clock are, however, inconsistent. We examined nine healthy young male permanent shift workers with high work satisfaction at the end of a week on night work and seven male controls with normal diurnal working hours. All subjects were admitted to a research facility for 28 h, and blood was collected with a continuous-withdrawal pump in portions taken hourly for the estimation of the circadian melatonin (MT) and cortisol secretion pattern. One control did not exhibit a circadian secretion pattern. When compared with the other controls (n = 6), all except one of the shift workers showed no difference in the phase or phase relationship of their hormonal profiles. In the shift workers, a minor trend toward elevation of the MT amplitude and an increase in two indicators for the amount of MT secreted were noticed. One individual displayed inverse hormone rhythms with an undisturbed phase relationship of MT and cortisol and inconspicuous hormone amplitudes. He showed, however, an inverse day-night rhythm in his private life, too. The data collected suggest that even permanent night workers with a high degree of work satisfaction do not usually lose the diurnal orientation of their endogenous clock. Factors other than reorientation of the circadian system may be more important for high tolerance to shift work.

Adult↗
PubMed1992

Septo-optic dysplasia and growth hormone deficiency: accelerated pubertal maturation during GH therapy.

We report four patients (three male, one female) with septo-optic dysplasia and growth hormone deficiency. All had GH therapy for a period of four to eight years until reaching final height. In all four cases bone maturation during puberty was accelerated (1.4 to 1.9 "years"/year), resulting in a final height which was clearly below the predicted height. The progress of pubertal stages was very short in all patients. In three patients TSH and prolactin release after TRH stimulation were increased. These data support a hypothalamic original of the endocrine disorder. Insufficient GH release, even after repeated GHRH stimulation, is in contrast to this assumption. In one case there was a late manifestation of neurohormonal diabetes insipidus, which indicates the possibility of later disease progression. MR imaging of the brain demonstrated variable malformation of the septum pellucidum, chiasma and nervus opticus or the pituitary gland, respectively.

Abnormalities, Multiple↗
PubMed1991

Circadian secretion pattern of melatonin in Parkinson's disease.

Although several studies on the efficacy and the toxicity of exogenous melatonin in Parkinson patients have been carried out, there are no data available on melatonin secretion in these patients. We therefore performed a controlled trial in 9 Parkinson patients (aged 62.1 +/- 8.7 years, x +/- SD) and in 14 control persons (58.0 +/- 10.4 years). Parkinson patients were treated with l-dopa (300-1000 mg per day) in combination with a peripheral decarboxylase inhibitor (benserazide, carbidopa). 14 venous blood samples were taken from each person during a period of 24 hours in order to investigate the circadian secretion pattern of melatonin. Serum melatonin levels were estimated by radioimmuno assay. We found that the circadian secretion patterns of l-dopa-treated Parkinson patients and age-matched controls were very similar except for a phase advance of the nocturnal melatonin elevation in the parkinsonian group.

Adult↗
PubMed1991

Serum melatonin in central precocious puberty is lower than in age-matched prepubertal children.

In children a progressive decrease in nocturnal serum melatonin (MT) has been shown with advancing age, suggesting a reduction in the amplitude of the circadian MT curve with maturation. Whether this alteration of MT levels is related to human sexual maturation or occurs independently remains to be elucidated. Also, the impact of gonadal steroids on the MT rhythm remains an open question. We examined 56 patients (51 females and 5 males) with central precocious puberty (52 idiopathic and 4 neurogenic). Patients were studied before and 3, 6, and 12 months after initiation of GnRH analog treatment. Three hundred and thirty-seven endocrinologically normal subjects (190 males and 147 females) served as controls. In all subjects nocturnal serum MT (blood collection between 2300 and 0100 h) was measured with a highly specific RIA. In young patients, aged 1-5 yr, we found significantly lower MT levels than in age-matched controls. Pubertal patients, aged 5-9 yr, displayed nocturnal MT levels in the same range as control subjects approaching normal pubertal age. In contrast to endocrinologically normal children, there was no age-dependent decrease in nocturnal MT in untreated precocious puberty; rather, it appeared that serum MT had already declined in association with the onset of sexual maturation. Although there was a significant difference in weight between patients and age-matched controls, the low MT values in patients 1-5 yr old were only partly explained by the weight difference (P less than 0.0009); their pubertal status also contributed significantly (P less than 0.006). Pituitary-gonadal suppression induced by long term GnRH analog treatment did not result in a return to prepubertal MT levels; rather, nocturnal MT decreased during therapy. The collected data indicate that nocturnal serum MT levels are related to sexual maturation, since serum MT is similar in precocious puberty and normal pubertal children. Since suppression of the pituitary-gonadal axis did not result in increases in nocturnal MT levels in young patients with precocity (i.e. return to age-appropriate levels), the reduction of nocturnal MT with normal puberty is not likely to be dependent on pubertal gonadotropin or sex steroid milieu.

Aging↗
PubMed1991

[Undulating course of precocious puberty].

The normal course of precocious puberty is progredient resulting eventually in full sexual maturation. In few cases a transient form of the disease has been recorded, characterized by a temporary appearance of signs of sexual maturation. We report on a female patient with an undulating course of the disorder: after precocious initiation of puberty, a temporary interruption and subsequent resumption of sexual maturation occurred. Presently, the patient is successfully treated with an LHRH-analogon. Within the framework of this case problems in diagnosis and treatment of precocious puberty are being discussed.

Age Determination by Skeleton↗
PubMed1990

Sleep laboratory investigations on hypnotic properties of melatonin.

Melatonin (MLT), a pineal hormone, has some sedative and hypnotic properties. To explore this effect further 20 young, healthy volunteers exposed to artificial insomnia participated in a double-blind, placebo controlled, parallel group design study. They slept in a sleep laboratory for several consecutive nights and were polygraphically monitored and subjected to a battery of psychometric tests and standardized self-report questionnaires each morning. One night all subjects received only placebo (21:00 hours) and on a second night half of them were subjected to placebo and half to MLT. On the later night blood MLT levels were measured. Polygraphic recordings revealed that MLT at bedtime decreased the time the subjects were awake before sleep onset (P less than 0.025), sleep latency (P less than 0.05), and the number of awakenings during the total sleep period (P less than 0.025), and increased sleep efficiency (P less than 0.05). In addition, it decreased sleep stage 1 (P less than 0.05) and increased sleep stage 2 (P less than 0.025). On the morning following the treatment most objective and subjective measures for awakening quality showed a trend towards improvement after MLT. One hour after its oral administration, serum MLT rose to a high pharmacological level (25817 pg/ml; median), but individual peak serum MLT levels varied by a factor of 300.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Melatonin secretion in Turner's syndrome: lack of effect of oestrogen administration.

Melatonin secretion was investigated in 13 girls with Turner's syndrome before and after long-term oestrogen administration. Oestrogen treatment resulted in an increase in the serum levels of the hormone and a decrease in blood progesterone concentration. No change, however, was observed in the melatonin secretion pattern (in terms of peak values, time of peak level and total melatonin secretion) after oestrogen therapy. A distinct circadian rhythm in serum melatonin was evident in all subjects with peak occurring around 0200 h and concentration similar to those of normal subjects.

Adolescent↗
PubMed1989

The short term secretion pattern of human serum melatonin indicates apulsatile hormone release.

It is well known that many hormones are secreted in a pulsatile fashion. Changes in pulse frequency and/or amplitude can have severe physiological and pathological consequences. Attempts to assess the short term secretion pattern of the pineal hormone melatonin (MLT) provided inconsistent results. The development of objective statistic- and computer-based pulse detection programs and the advent of more precise and specific MLT assay systems during recent years prompted us to reexamine the short term secretion of the pineal hormone. We investigated 16 healthy volunteers (8 males and 8 females), aged 28.1 +/- 6.7 yr (mean +/- SD). Five-milliliter blood specimens were collected at 10-min intervals from 1900-0900 h (n = 8), 3-min intervals from 2300-0300 h (n = 4), 10-min intervals from 0800-2200 h (n = 2), and 3-min intervals from 1100-1500 (n = 2). The serum MLT concentration in each specimen was measured with a previously described RIA. The sensitivity of the assay varied between 3.0-7.5 pg (0.013-0.033 pmol) MLT/tube. The intrassay variance was assessed on 10 serum pools to which varying amounts of MLT had been added, covering the entire range of the standard curve; the coefficient of variance varied between 16.6-6.1%. The sequence of MLT levels in each subject was examined for the existence of pulses by visual inspection and by the computer programs Pulsar and Cluster. Apart from the circadian rhythm, the three methods did not reveal clear pulses but, rather, continuous release of the pineal hormone during the day and night. We conclude that the pineal hormone MLT is, in contrast to many other hormones, secreted in an apulsatile manner. Very frequent blood sampling may be unnecessary for full characterization of the secretion pattern without loss of information. In addition to the circadian pacemaker, the pineal does not appear to be under the control of the proposed hypothalamic or an intrinsic pulse generator.

Activity Cycles↗
PubMed1989

Influence of estrogen administration on growth hormone response to GHRH and L-Dopa in patients with Turner's syndrome.

The modulating effect of estrogen on GH secretion was studied in 22 patients with Turner's syndrome. Estrogen administration (0.5 microgram/kg ethinylestradiol) for a period of 4 weeks resulted in a significant increase in basal GH concentrations (2.6 vs 4.8 micrograms/l, P less than 0.01). The L-Dopa-stimulated GH concentrations were also significantly increased (P less than 0.01), whereas no effect of estrogen substitution on GH responses to GHRH (1-44) and Sm-C levels was seen. Our findings demonstrate a priming effect of estrogen on GH secretion in patients with Turner's syndrome. These patients generally lack the puberty-associated rise in GH secretion, which might be due to ovarian failure and the concomitant estrogen deficiency.

Adolescent↗
PubMed1988

[Discrimination between epileptic and non-epileptic seizures using defined prolactin studies].

Prolactin blood levels (HPRL) increase within 20 minutes postictally after generalized epileptic, especially generalized tonic-clonic seizures and return to normal values within one hour. Elevated HPRL levels were also observed after complex partial seizures, but usually in less extent, exceeding normal ranges only slightly. Therefore baselin HPRL measurements are necessary for estimation of spontaneous fluctuations in comparison to changes after seizures. Unchanged PRL levels after attacks do not support their epileptic origin. Rage attacke showed no clear pattern of PRL changes.

Adolescent↗