Biomedical subjects
H Mönig
Publications and source records attributed to H Mönig.
[Modern therapy of hypophyseal tumors].
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Growth hormone secretion in response to the new centrally acting antihypertensive agent moxonidine in normal human subjects: comparison to clonidine and GHRH.
It is well established that the central alpha 2-adrenergic agonist clonidine can enhance growth hormone (GH) secretion in humans. This effect is most likely due to stimulation of hypothalamic growth hormone releasing hormone (GHRH) release. To determine the potency of the new I1-imidazoline receptor agonist moxonidine to release pituitary hormones, 12 normal volunteers received clonidine (0.3 mg), moxonidine (0.3 mg), or placebo orally according to a randomized, double-blind protocol. Blood was drawn prior and up to 180 min after drug administration for determination of GH, adrenocorticotropic hormone (ACTH), prolactin, thyrotropin (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), glucose, clonidine, and moxonidine concentrations. The results were compared to those obtained in a standard GHRH stimulation test (1 microgram/kg i.v.). Serum GH levels increased significantly in response to GHRH, clonidine, and moxonidine. However, the increase was less pronounced in response to clonidine and moxonidine as compared to GHRH (mean +/- SEM): after clonidine, GH increased from 0.2 +/- 0.1 to 5.4 +/- 1.5 ng/ml, p < 0.05; moxonidine increased GH levels from 0.1 +/- 0.04 to 4.8 +/- 1.9 ng/ml (p < 0.05); GHRH caused an increase from 0.01 +/- 0.05 to 14.8 +/- 2.5 ng/ml (p < 0.05). No significant change was observed in the concentration of any other pituitary hormone. We conclude that the new I1-imidazoline receptor agonist moxonidine stimulates GH release to a similar extent as clonidine.
[Hypocalcemic cardiomyopathy as the cause of severe left heart failure].
A 25-year-old man was hospitalized because of dyspnoea and retrosternal pain. There were clinical and radiological signs of severe left ventricular failure which within a few hours necessitated artificial ventilation. A year before he had been diagnosed as having pseudohyperparathyroidism and disseminated encephalomyelitis. Administration of calcium and vitamin D was only partially efficacious. On admission the calcium concentration was 1.5 mmol/l. The severe left ventricular failure did not respond adequately to the usual therapeutic measures including artificial ventilation and catecholamines. A cumulative dose of about 50 mmol calcium was administered intravenously over 10 days, but marked improvement in myocardial function already became apparent at a calcium concentration of about 1.8 mmol/l. Lasting correction of the hypocalcaemia was achieved with 0.5 g calcium three times daily by mouth and 0.5 mg/d dihydrotachysterol. After transfer to a special neurological department because of an acute attack of multiple sclerosis there was no detectable impairment of cardiac function. This case demonstrates that hypocalcaemic cardiomyopathy should be considered in the differential diagnosis of heart failure in previously well young persons who do not respond adequately to the usual treatment. Myocardial impairment is fully reversible after administration of calcium.
Suppressed thyroid-stimulating hormone secretion in patients treated with interleukin-2 and interferon-alpha 2b for metastatic melanoma.
Recent reports suggest that combined therapy with recombinant interleukin (IL)-2 and interferon (IFN) alpha 2b may result in autoimmune-induced thyroid dysfunction. We prospectively analyzed thyroid function for 6 weeks in two groups of patients with progressive metastatic melanoma treated according to two different protocols. In group I (n = 17) three treatment cycles were given, each with three weeks of subcutanous administration of rIL-2 and INF-alpha 2b at different doses. In group II (n = 13) the chemotherapeutic agent dacarbazine was given in addition. In group 1 three patients developed frank hyperthyroidism, which required antithyroid drug therapy in one case. Autoantibodies against thyroid microsomal antigen, thyroglobulin, and the thyroid-stimulating hormone (TSH) receptor were not significantly elevated in any of these patients. However, the remaining 14 patients showed a significant decrease in TSH after 6 weeks of treatment, from 1.8 +/- 0.9 to 0.7 +/- 0.7 microU/ml (P < 0.02). Thyroid hormones (triiodothyronine, thyroxine, free thyroxine) also increased during the observation time, but this did not parallel the drop in TSH levels. Only thyroxine increased above the upper limit of normal, while triiodothyronine and free thyroxine stayed within the normal range. In group II, 6 of 13 patients (46%) had a decreased TSH after 6 weeks of treatment. Mean TSH was 1.5 +/- 1.4 before and 0.8 +/- 0.6 microU/ml after 6 weeks and was totally suppressed in three cases. None of these patients showed ouvert hyperthyroidism. Hypothyroidism was not observed in either group.(ABSTRACT TRUNCATED AT 250 WORDS)
Hormone measurement in blood from inferior petrosal sinus: clinical and experimental implications.
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[The ectopic ACTH syndrome. The current clinical and molecular biology aspects].
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The effect of endotoxin on preirradiated mice.
Adult male mice were given a whole body irradiation with non-lethal doses of 2.5 or 5 Gy. Unirradiated animals served as controls. The animals (including controls) received a single injection of endotoxin (LPS from Salmonella abortus equi) with doses of 100, 200 or 400 micrograms one day up to one year after irradiation. Twelve, 24 or 48 hours after lipopolysaccharide (LPS) application the animals were killed and dissected. Animals which died spontaneously were also examined. Liver, lung, kidney, small intestine, and stomach were histologically investigated. The histological findings showed, that differences exist between irradiated and unirradiated mice and that the cause of death is also different for animals dying spontaneously. The investigations have shown that after irradiation phases of different degrees of sensitivity with regard to the endotoxin response exist. This behaviour can be observed by different lethality rates or in the light of the histological results. Moreover, the histological findings have shown, that distinct regenerative changes occur first of all in the liver, in the mucosa of small intestine, and the gastric mucosa, in which the number of differentiated cells compared with the mitotic active cells is reduced. It can be ascertained, that a whole body irradiation with 2.5 to 5 Gy enhances an additional injury by endotoxin weeks to months later. Contrary to this a preirradiation a few days before endotoxin application leads to a "protection" against the efficacy of endotoxin. These findings can be explained by modes of action described in literature, according to which endotoxins induce the formation of highly active mediators especially the tumor necrosis factor.
Pharmacokinetics of encainide in patients with cirrhosis.
The pharmacokinetics of encainide were investigated in 10 patients with cirrhosis and 10 matched controls following single intravenous (IV, 25 mg), single oral (so, 25 mg), and multiple oral (mo, 25 mg thrice daily over 5 days) dosing. The hepatic oxidative drug-metabolizing enzyme capacity and its inducibility were assessed by antipyrine elimination and 6-beta-hydroxycortisol excretion. Eight controls and nine patients were of the extensive metabolizer phenotype (EM), as assessed by the sparteine metabolic ratio. Statistics was performed in EM only. The antipyrine half-life was significantly longer and clearance was significantly lower in patients with cirrhosis. Following IV administration, no significant differences in encainide half-life clearance, volume of distribution, or the area under the plasma concentration time curve (AUC) were observed between patients and controls. Following so and mo, there was a fourfold reduction in the oral clearance in cirrhotics. Thus, encainide bioavailability was increased in cirrhosis. Whereas the AUC of encainide was significantly higher in patients, no differences were observed in its active metabolites, O-desmethyl-encainide (ODE) and 3-methoxy-O-desmethylencainide (MODE). Plasma concentrations of encainide and its metabolites after 3 and 5 days of mo suggested steady-state conditions after 3 days of oral dosing. No change in antipyrine elimination and 6-beta-hydroxycortisol excretion following mo occurred. There was no relationship between parameters of encainide and antipyrine elimination. In conclusion, even though the elimination of encainide was reduced in patients with cirrhosis, plasma levels of the pharmacologically active metabolites, ODE and MODE, were comparable.(ABSTRACT TRUNCATED AT 250 WORDS)
Enzyme-inducing properties of probenecid in man.
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The effects of frusemide and probenecid on the pharmacokinetics of phenprocoumon.
We have studied the pharmacokinetics of phenprocoumon with and without co-administration of frusemide and probenecid in two groups of 17 healthy volunteers. Frusemide 40 mg b.i.d. for 7 days did not interact with phenprocoumon to a significant extent. Probenecid 500 mg q.i.d. for 7 days significantly accelerated the overall elimination of phenprocoumon, as indicated by a decrease in AUC from 295 to 157 micrograms.h.ml-1, and a reduction in the fraction of the dose excreted by the kidneys. The data are consistent with inhibition of the glucuronidation of phenprocoumon by probenecid. Its accelerated elimination may be a consequence of the increased formation of hydroxylated metabolites.
Effect of oral contraceptive steroids on the pharmacokinetics of phenprocoumon.
1. The effect of chronic administration of oral contraceptive steroids (OCS) on the pharmacokinetics of the oral anticoagulant phenprocoumon was investigated in seven healthy females. 2. Plasma concentrations of phenprocoumon and the urinary recovery of unchanged as well as conjugated drug were measured following a single oral dose of 0.22 mg kg-1. A group of seven non-smoking, drug-free women matched for age and body weight served as controls. 3. Administration of OCS was associated with a significant increase in the clearance of phenprocoumon from 1.6 +/- 0.7 to 2.0 +/- 0.7 ml min-1 kg-1 (P less than 0.05). The urinary recovery of phenprocoumon glucuronide was significantly higher in OCS users (21.0 +/- 16 vs 14.0 +/- 10 (% of dose); P less than 0.05). No difference in plasma protein binding of phenprocoumon was observed, being 99.2 +/- 0.07 in both groups. 4. The accelerated glucuronidation of phenprocoumon in OCS users suggests the need for careful monitoring of the anticoagulatory response in these subjects, especially when the OCS are withdrawn.
Prolonged radioprotective activity of WR-2721 linked to dextran.
The radioprotective agent WR-2721 was linked to dextran and poly(glutamic acid) respectively, to obtain a prolonged radioprotective ability. Male mice were administered these water soluble polymer conjugates one to 72 hours prior to a whole body irradiation with X-rays. A prolongation of radioprotective efficiency was achieved with two dextran-(WR-2721)-conjugates. For a period of 24 hours between administration, and irradiation dose reduction factors of 1.14 +/- 0.04 and 1.10 +/- 0.03 respectively were found. After 72 hours, no protective effect was observed. Histopathological investigations of the liver for formation of tumors 200 to 600 days after irradiation seems to indicate that a protective effect is not produced by the dextran-(WR-2721)-conjugates.
[The work and influence of Hanns Langendorff].
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[Probenecid affects liver metabolism].
The effect of probenecid on the pharmacokinetics of phenprocoumon (PPC) given as a single oral or intravenous dose, on the vitamin-K-dependent protein-C-antigen, and on the pharmacokinetics of antipyrine and 6 beta-hydroxycortisol was determined in 14 healthy volunteers. Probenecid caused a 75% decrease in urinary excretion of PPC and PPC-glucuronide and shortened the plasma half-life of PPC significantly (by about 35%). The results after oral and intravenous administration of PPC did not differ significantly. Plasma protein-C-antigen concentrations following intravenous PPC were significantly increased by probenecid. The plasma half-life of antipyrine after 7 days of probenecid therapy was significantly diminished. Accordingly, urinary excretion of 6 beta-hydroxycortisol was significantly increased. These data appear for the first time to reveal enzyme-inducing properties of probenecid, which may be responsible for the shortening of PPC plasma half-life when probenecid is given simultaneously. In addition, the influence of probenecid on plasma protein-C-antigen concentrations may indicate further effects of probenecid on liver metabolism.
[Circulatory collapse caused by carbachol-containing eye drops].
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[Defibrination syndrome after snake bites].
A defibrination syndrome developed in two men (aged 51, and 29 years old) within two hours of having been bitten by vipers Echis carinatus and Agkistrodon halys, respectively. In both the syndrome was characterized by afibrinogenemia with prolongation of the thrombin time, presence of fibrin monomers and split products of fibrinogen. Haemorrhagic signs included oral mucosa bleeding and macrohematuria. Specific serum was administered 9 and 16 hours, respectively, after the bite and achieved normalization of all clotting values within 48 hours.
Influence of nitrendipine and verapamil on plasma levels, urinary excretion, and beta-blocking effect of metoprolol.
Following randomized allocation eight healthy volunteers were treated for 1 week each with metoprolol alone (100 mg twice daily), verapamil 80 mg three times a day plus metoprolol 100 mg twice daily, and with nitrendipine 20 mg twice daily. Plasma levels and urinary recovery of the beta-blocker, antipyrine clearance, and heart rate on exercise were measured. Verapamil and nitrendipine slightly prolonged elimination half-life of metoprolol. The urinary recovery of the parent beta-blocker and of its alpha-hydroxy metabolite was elevated by both calcium antagonists (verapamil and nitrendipine). Exercise tachycardia (150 beats/min without drugs) was inhibited more pronounced on the combination therapies than under metoprolol administration alone. Results of the present study indicate that calcium antagonists enhance inhibition of exercise tachycardia caused by metoprolol, possibly due to their binding to myocardial beta-adrenergic receptors which is known from the literature. As both calcium antagonists did not increase plasma levels of metoprolol, in the present study a kinetic interaction between the beta-blocker and the calcium channel blockers investigated does not appear to be responsible for the pharmacodynamic effects observed.