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Biomedical subjects

D Klingmüller

Publications and source records attributed to D Klingmüller.

At least 73 records · Page 4Linked to original sources

Seven-day administration of the gonadotropin-releasing hormone antagonist Cetrorelix in normal cycling women.

In contrast to gonadotropin-releasing hormone (GnRH) agonists, GnRH antagonists do not show any stimulatory effect on the pituitary but their clinical usage was precluded by severe side effects and high dose requirements. We report here on a 7-day treatment using the potent GnRH antagonist Cetrorelix ([Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]GnRH) on five women 23-33 years old. All women were ovulatory and were studied during three consecutive cycles: a control cycle, a treatment cycle and a post-treatment control cycle. Throughout the control cycles blood samples were obtained daily during cycle days 8-18 and on days 21 and 23 during the remainder of the control cycles. On the eighth day of the treatment cycle women were hospitalized at 07.00 h for 26 h. Repeated blood samples were drawn at 15-min intervals during the entire period. Subjects received 3 mg of Cetrorelix sc for the first time at 09.00 h on the eighth day of the cycle and daily at 08.00 h for the following 6 days. Blood samples were obtained daily over a period of 25 days and every third day throughout the remainder of the treatment cycle. Twenty-four hours after the first application of Cetrorelix, luteinizing hormone (LH) and estradiol were in the subnormal range and remained subnormal until the end of medication. The suppressive effect of Cetrorelix compared to pretreatment values lasted at least 6 days for LH and FSH and 11 days after the last Cetrorelix injection for estradiol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The role of LHRH-analogues in protecting gonadal functions during chemotherapy and irradiation.

Therapeutic success has focused attention on late effects in patients with testicular cancer, Hodgkin's disease, non-Hodgkin's lymphoma, and acute leukaemia. Since most patients with testicular cancer are young, the impact of cytotoxic chemotherapy on fertility and hormone deficiency has become particularly important. It has been shown that pulsatile secretion of luteinizing hormone releasing hormone (LHRH) is a prerequisite for normal gonadal function. In contrast, non-pulsatile, chronic treatment with supraphysiological doses of LHRH-analogues (LHRHA) results in suppression of the pituitary-gonadal axis. It has been suggested that inhibition of spermatogenesis during exposure to cytotoxic drugs might reduce gonadal toxicity. The protective effects of LHRHA during chemotherapy or irradiation has been examined in 11 preclinical studies. In only 6 out of 11 models could protection be demonstrated. Four clinical trials have been performed using LHRHA as a gonadal protector. In none of these trials could LHRHA significantly influence severity and duration of germ cell impairment. New approaches are needed to minimize or even prevent gonadal toxicity during chemotherapy or irradiation, such as reduction of courses, alternative schedules, or new drugs.

Animals↗

Hormonal responses to the new potent GnRH antagonist Cetrorelix.

GnRH antagonists, unlike the GnRH agonists, immediately suppress gonadotropins and testosterone secretion without initial stimulatory effect. We report here on a single-dose study with the new GnRH antagonist Cetrorelix (Ac-D-Nal(2)1, D-Phe(4C1)2, D-Pal3, D-Cit6, D-Alal0) in 25 normal men. The study involved five different dose groups (0.25, 0.5, 1.0, 1.5 or 3.0 mg) and subjects were observed over a 40 h period. Five men served as controls. Serum levels of LH, FSH and testosterone decreased rapidly with a dose-related decline for testosterone of 25%, 24%, 41%, 53% and 72%, respectively, for testosterone within the first 8 h of antagonist administration. All effects were reversible and no serious side effects were observed. Thus, this GnRH antagonist is active in men even in small doses and could become a new therapeutic tool for sex hormone-dependent diseases. Cetrorelix seems to have the highest suppressive rate per mg peptide of all other antagonists from the literature, such as Nal-Glu (Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal3, Arg5, D-Glu6(AA), D-Alal0), Detirelix (Ac-D-Nal(2)1, D-pCl-Phe2, D-Trp3, D-hArg(Et2)6, D-Alal0) or 4F (Ac-delta 3Prol, 4F-D-Phe2, D-Trp3,6). During the time of suppression after a dose of 3 mg there was an LH and testosterone peak in the early morning coinciding with the testosterone peak in untreated men. The GnRH antagonist seems to unmask the circadian rhythm of LH secretion.

Adult↗

Urinary excretion of GH in healthy individuals and patients with acromegaly, hypopituitarism and dwarfism.

Urinary GH excretion reflects average plasma levels. Using a highly sensitive sandwich enzyme immunoassay we determined GH concentrations in the 24 h accumulated urine samples of 54 healthy persons (aged 1.5-90 years), 8 acromegalic patients, 4 acromegalic patients after enucleation of a GH-producing adenoma, 8 patients with partial hypopituitarism and in first morning urine and 12 h accumulated daytime urine of 4 healthy children and 3 children with growth failure. GH secretion is age-dependent, with high rates between ages 1 and 20 (ages 0-20 years: 10.4 ng/g creatinine +/- 6.3 vs age > 20-75 years: 3.1 ng/g creatinine +/- 1.6). An age-dependent increase in urinary GH is found in the pubertal age group (10 ng/24 h +/- 6.8 vs prepubertal group: 4.6 ng/24 h +/- 2.95). GH excretion of patients with acromegaly differs significantly from healthy subjects (72 ng/24 h +/- 49 vs 3.9 ng/24 h +/- 2.3). After a successful operation, acromegalic patients do not differ from the collective norm. Six of 8 patients with partial hypopituitarism show lower GH concentrations in urine than healthy subjects (1.2 ng/l +/- 0.2 vs 2.6 ng/l +/- 1.2), but daily GH output does not differ, since significantly more urine is then excreted. At night, healthy children secrete significantly more GH than during the day (night: 0.16 ng.kg-1 x (12 h)-1 +/- 0.02 vs day: 0.07 ng.kg-1 x (12 h)-1 +/- 0.03), while output is the same for GH-deficient children. Both groups have similar GH daytime output, but GH-deficient children have significantly less nocturnal output.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗

Endocrine abnormalities in mitochondrial myopathy with external ophthalmoplegia.

Endocrine functions were examined in 21 patients with mitochondrial myopathies presenting with chronic progressive external ophthalmoplegia and other additional neurological and multisystemic symptoms. Ten patients had the features of the Kearns-Sayre syndrome. Deletions of the mitochondrial DNA were found in 4 out of 5 patients examined. Fourteen patients, including 3 with deletions of the mitochondrial DNA, had various and often multiple endocrine abnormalities: 6 patients were of short stature, 3 had irregular menstrual cycles, 3 had undersized testicles, 5 showed an insufficient rise of growth hormone following the administration of growth-hormone-releasing hormone, 4 showed an insufficient rise in FSH after administration of gonadotropin-releasing hormone, 5 had manifest diabetes mellitus, 3 showed an impaired glucose tolerance, and 2 patients had subnormal serum levels of parathormone in combination with hypocalcaemia. One patient additionally had Klinefelter's syndrome with a kariotype 47, XXY and increased levels of FSH and LH, subnormal levels of testosterone and subnormal testicular volume. The occurrence of endocrine defects correlated with the duration of disease. The data demonstrate that endocrine abnormalities are frequently associated with mitochondrial myopathy, indicating that this multisystemic disease also involves various endocrine tissues.

Adult↗

[A comparison of the value of magnetic resonance tomography and computed tomography in Nelson syndrome patients].

The hypophyses of 13 patients with Nelson syndrome following bilateral adrenalectomy were examined by MRI and CT. Diffuse enlargement of the hypophysis was demonstrated in 8 patients by CT and in 9 by MRI. Compared with CT, MRI provides better demonstration of tumour development, such as abnormal convexity of the cranial margin of the hypophysis (MRI 4/13, CT 1/13), displacement of the infundibulum (MRI 4/13, CT 0/13) or optic chiasm (MRI 2/13, CT 0/13). MRI also provides diagnostically important differentiation between scar tissue and recurrence of tumour following hypophysectomy (MRI 1/3, CT 0/3) and more accurate demonstration of infiltration of the cavernous sinus (MRI 4/13, CT 2/13). CT is superior only in showing the floor of the sella. MRI is the method of choice for imaging in cases of Nelson syndrome.

Adrenalectomy↗

Direct measurement of immunoreactive renin during changes of posture in man.

For several years, it has been possible to determine renin by a direct RIA. In the present study, plasma active renin concentration (PRC) was related to plasma renin activity (PRA) and aldosterone as a function of a standardized posture test. Using PRC, our target was to define the shortest necessary test duration. The three parameters were examined in 10 healthy male subjects (22-34 years old). Salt balance was determined in 24-hour urine, and plasma potassium and sodium were measured. Volunteers were hospitalized for 1 night, and at 8 a.m. the next morning they were subjected to the following postural changes: 3 h active orthostasis and 3 h recumbency. Frequent blood samples were taken. Orthostasis induced a significant rise in PRC, PRA and aldosterone already after 15 min. PRC and PRA reached a maximum level after 90 min of orthostasis and remained relatively stable, while aldosterone reached its highest level already after 30 min and then gradually decreased. Significant correlations were found between PRA and PRC (p < 0.001), between PRC and aldosterone (p < 0.001), and between PRA and aldosterone (p < 0.001). The PRC/PRA ratio changed during the course of the test, especially in supine subjects. When subjects returned to the supine position, all the parameters measured began a continual decrease. There were no significant changes in serum potassium and sodium levels throughout the duration of the test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Immunoreactive plasma inhibin levels in men after polyvalent chemotherapy of germinal cell cancer.

In vitro studies have shown that the Sertoli cell is the primary source of inhibin in the male. We measured immunoreactive inhibin with a new two-site immunoenzymatic assay in the plasma of 92 men: 40 normal men, 7 patients with germinal cell cancer after unilateral orchidectomy and 45 patients with the same disease following unilateral orchidectomy and subsequent chemotherapy based on cisplatin. Normal men had inhibin levels of 1.77 +/- 0.09 U/l x 10(-3) (mean +/- SEM). Seven patients after unilateral orchidectomy had inhibin concentrations within the lower normal range (1.23 +/- 0.22 U/l x 10(-3)). Forty-five patients were investigated in a cross-sectional study up to 102 months after completion of chemotherapy. Inhibin levels were within the normal range in 25 patients (1.76 +/- 0.14 U/l x 10(-3)); 18 patients had significantly lower inhibin levels (0.48 +/- 0.05 U/l x 10(-3), p less than 0.005) when compared to patients after unilateral orchidectomy. Two patients had elevated inhibin levels (4.4 and 5.6 U/l x 10(-3)). The proportion of patients with normal and subnormal inhibin was not dependent on the time that elapsed after completion of chemotherapy or on the chemotherapy combination. There was no correlation between immunoreactive plasma inhibin and LH, FSH, testosterone or sperm count. The decrease in inhibin concentrations after chemotherapy may indicate long-term damage to Sertoli cells in some of the patients.

Adult↗

Activation of epileptic foci by transcranial magnetic stimulation: effects on secretion of prolactin and luteinizing hormone.

Transient elevation of serum levels of prolactin has been observed following several types of epileptic seizures and after electrical stimulation of limbic temporal lobe structures via implanted electrodes. Transcranial magnetic stimulation has been found to selectively induce epileptiform afterdischarges in the epileptic focus of candidates for epilepsy surgery who suffered from temporal lobe epilepsy. Lateralized serial transcranial magnetic stimulation was therefore used and serum levels of prolactin or luteinizing hormone were measured to find if it could be used as a non-invasive diagnostic tool. The investigation was performed on six patients and five healthy volunteers. In the patients the induction of epileptiform potentials was continuously monitored via subdural electrodes. A transient surge of prolactin and luteinizing hormone was found in only one patient, in whom a complex partial seizure was induced. Thus, transcranial magnetic stimulation appeared not to be helpful for the lateralization of the (primary) epileptic focus during presurgical evaluation.

Adult↗

[Type I multiple endocrine neoplasia--Wermer syndrome].

Multiple endocrine neoplastic diseases are genetically determined conditions with particular organ patterns for endocrine tumors. In Type I or Wermer's syndrome the endocrine pancreas, anterior pituitary and parathyroids are involved, insulinoma being the most frequent pancreatic tumor. To facilitate diagnosis, a prolonged oral glucose tolerance test, a fasting test and determination of the glucose-insulin ratio are recommended. Localisation is sought by computer tomography and angiography. A gastrinoma is excluded on the basis of normal gastrin levels in serum and by means of the secretin-provocation-test. Pituitary tumors can be classified more closely with prolactin levels and releasing-hormone tests (LH-RH and TRH). Prolactinoma is the most frequent pituitary tumor and amenable to bromocryptin treatment. If Wermer's syndrome is suspected, primary hyperparathyroidism has to be excluded on the basis of calcium and parathormone levels. Chief cell hyperplasia or multiple adenomas are frequent. Surgical resection is necessary.

Adenoma, Islet Cell↗

[Disorders of the hypothalamo-hypophyseal-gonadal axis and erectile impotence].

In the course of a standardized diagnostic programme LH, FSH, testosterone, prolactin and oestradiol were measured in 204 patients with erectile impotence (mean age 47.6 years). A purely organogenic abnormality was found in 125 (61.3%), a mixed organogenic-psychogenic one in 39 (19.1%), and a purely psychogenic one in 40 (19.6%). Thirteen patients (6.3%) had an abnormality of the hypothalamic-hypophyseal-gonadal axis, nine in addition had severe organogenic changes as the clear cause of the impotence. History and clinical findings were unremarkable in only one patient. Routine determination of hormones would seem to be cost-effective only if an important organic deficit has been excluded as the cause of an erection abnormality and therapeutic consequences can be drawn from any abnormal hormone values that are obtained.

Adult↗

[Magnetic resonance tomography (MRT) of the adrenals].

Thirty-eight MRT examinations were carried out in 35 patients who, between them, had 19 abnormalities in the adrenal glands. These included ten adenomas, three metastases, two carcinomas, two phaeochromocytomas, and two primary retroperitoneal tumours. MRT provides images of normal and abnormal adrenal glands which are equivalent to those of CT, with the exception that it cannot demonstrate calcification. Using a ratio of signal intensity from the adrenal tumours and the liver on T2-weighted images, it is usually possible to differentiate adenomas from metastases, carcinomas or phaeochromocytomas. The increased specificity of MRT is valuable in the investigation of patients with asymptomatic enlargement of the adrenal glands.

Adrenal Gland Neoplasms↗

[MR tomography of Kallmann's syndrome].

MR tomography is the only imaging method that can demonstrate atrophy of the olfactory lobe of the brain in olfacto-genital dysplasia (Kallmann's syndrome). The MRT findings in five patients with Kallmann's syndrome are described. The MRT criterion for the presence of Kallmann's syndrome appears to be an interruption or total absence of the olfactory sulcus.

Adult↗