K. Lichtwald
Heidelberg University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by K. Lichtwald.
Journal of Steroid Biochemistry | 1984
A. Milewicz; P. Vecsei; S. Korth-Schütz; D. Haack; A. Rösler; K. Lichtwald; Sabina Lewicka; G.v. Mittelstaedt
Specific 21-deoxycortisol (21-DF) antiserum was raised in New Zealand white rabbits using a 21-DF-3,20-oxime-bovine serum albumin complex. Plasma radioimmunoassay of 21-DF was developed and used together with a radioimmunoassay of 17-hydroxyprogesterone (17-OH-P) for diagnosis of patients with 21-hydroxylase deficiency of congenital and postpubertal forms. The assays were performed in plasma extracts after isolation by paper chromatography. The response of plasma 21-DF and 17-OH-P to i.v. ACTH (25 IU) was studied in 15 adult controls and compared to 8 women with the late onset form of 21-hydroxylase deficiency and 23 women with idiopathic hirsutism. Normal 21-DF values for women were 6.9 +/- 3.6 ng/dl and for men 9.71 +/- 2.73 ng/dl. Newborn children (age: 3-10 days) had a value of 8.3 +/- 4.8 ng/dl. These values are definitely lower than the lowest value ever published. This is possibly due to the specificity of the antibody. During the menstrual cycle the 21-DF values did not change. The baseline and post-stimulated concentrations of hormone were similar in controls and women with hirsutism but were significantly higher in women with the late onset form of 21-hydroxylase deficiency. In the congenital form of 21-hydroxylase deficiency the 21-DF values (baseline) were high. In general, the 21-DF and 17-OH-P values have shown parallel changes. However, one case of 21-hydroxylase deficiency with elevated 21-DF but normal 17-OH-P was observed. The use of 21-DF for the diagnosis of 21-hydroxylase deficiency is suggested.
Journal of Steroid Biochemistry | 1983
P. Vecsei; S. Abdelhamid; G.V. Mittelstädt; K. Lichtwald; D. Haack; Sabina Lewicka
The value of the urine tests: free aldosterone, aldosterone-18-glucuronide, tetrahydroaldosterone 18-hydroxycorticosterone and 18-hydroxydeoxycorticosterone in distinguishing primary aldosteronism from essential hypertension was studied in patients with typical and atypical primary aldosteronism and in patients with essential hypertension. The discriminating function of the tetrahydroaldosterone determination was the best, followed by 18-hydroxycorticosterone, free aldosterone and aldosterone-18-glucuronide. The measurement of 18-hydroxydeoxycorticosterone was without distinguishing value. Three cases with hypertension, adrenal adenoma, elevated 18-hydroxycorticosterone but normal aldosterone values were observed. In longitudinal studies the excretions of aldosterone, aldosterone metabolites and possible precursors periodically varied independently of each other. Determinations of urine aldosterone, aldosterone metabolites, 18-hydroxycorticosterone and 18-hydroxydeoxycorticosterone were not applicable for differential diagnosis of the adenoma and hyperplasia forms of primary aldosteronism.
Journal of Steroid Biochemistry | 1981
S. Abdelhamid; P. Vecsei; D. Haack; K.-H. Gless; D. Walb; P. Fiegel; K. Lichtwald
Abstract Urinary “free” (unconjugated) 18-hydroxy-corticosterone (18-OH-B), together with aldosterone-18-glu-curonide, “free” aldosterone and tetrahydroaldosterone were determined in 20 patients with primary aldosteronism. In 19 out of 20 cases (both in adenoma and hyperplasia) the 18-OH-B excretion was at least temporarily increased. On the basis the measurement of the 18-OH-B excretion was applied-in addition to determinations of aldosterone and aldosterone-metabolites-to search for cases of primary aldosteronism. Increased 18-OH-B excretion was found in 20 of 165 pre-selected patients with essential hypertension. In 11 of them, at least one of the urinary aldosterone values was concomitantly elevated. In 9 patients the aldosterone values were found to be within normal ranges. Follow-up studies have shown elevated aldosterone values in some members of the latter group, and in 3 patients first believed to have essential hypertension adrenal adenomas were established. In 2 patients the adenoma was removed.
Developmental Biology | 1986
Ulrich Tümmers; Thomas Müller; Rupert Schmidt; Klaus Seidl; K. Lichtwald; Paul Vescei; Hans-Joachim Wagner; Klaus Unsicker
Using beta-bungarotoxin (beta-BTX) as a tool to eliminate the preganglionic cholinergic nerve supply to the embryonic rat adrenal gland, we have investigated whether or not these nerves affect the differentiation of embryonic chromaffin cells (pheochromoblasts). Rat fetuses received a single injection of 1 or 2 micrograms beta-BTX or an identical volume of saline at embryonic day (E) 17 and were taken for morphological and biochemical analyses at E 21. Administration of beta-BTX caused a 15 to 20% reduction in body weight, crown-rump-length and adrenal weight. Spinal cord development was reduced and acetylcholinesterase-positive cells in ventral and lateral columns were virtually absent in toxin-treated animals. In adrenal glands, a decrease of choline acetyltransferase activity to 13% of control levels and a concomitant decrease of ultrastructurally identifiable nerve fibers and axon terminals revealed that application of 2 micrograms beta-BTX effectively reduced the neuronal input to E 21 adrenal glands. Values for total adrenal catecholamines, relative amounts of adrenaline and noradrenaline, tyrosine hydroxylase and phenylethanolamine N-methyltransferase activities were unaltered. All ultrastructural features of pheochromoblasts (except the lack of synapse-like axon terminals) were inconspicuous. Corticosterone levels in adrenals and plasma were identical to controls. These data strongly suggest that normal embryonic development of adrenal chromaffin cells does not require an intact nerve supply.
Journal of Steroid Biochemistry | 1979
D. Haack; P. Vecsei; K. Lichtwald; Walter Vielhauer
Abstract (1) Although the spontaneous mortality of rabbits immunized with corticosteroid and corticosteroid metabolite antigens increased, no certain biological effect of active or passive immunizations against corticosteroids could be established. 1. (2) The total plasma concentrations of antigen steroids always increased while the concentrations of antigen independent corticosteroids were frequently elevated. 2. (3) Elevations of free corticosteroid levels were estimated by equilibrium dialysis. These results were confirmed qualitatively, but not quantitatively, by other techniques, e.g. by estimating urinary-free steroids. 3. (4) One of the reasons for the discrepancy between the absence of biological effects and increased free steroid levels may be a disturbance of the dynamic equilibrium of plasma-bound and free steroids caused by an interaction between plasma proteins, antibody and antigen steroid.
Clinical and Experimental Hypertension | 1982
P. Vecsei; S. Abdelhamid; D. Haack; K. Lichtwald; Sabina Lewicka; G. V. Mittelstädt
Two female patients, 54 and 34 years old, each presented with an adrenal adenoma and hypertension. Blood pressure fell after removal of the tumors. The first patient had high urinary 18-hydroxycorticosterone and periodically elevated 18-hydroxy-deoxycorticosterone excretions. The second patient had elevated 18-hydroxycorticosterone and free cortisol excretions. Urinary aldosterone, aldosterone metabolites and plasma aldosterone were not increased. Plasma renin activity was suppressed and serum potassium levels were normal. After surgery, no elevated steroid values were found. Elevated 18-hydroxycorticosterone excretion may be an indicator of yet unknown hypertensinogenic mechanisms. The role of 18-hydroxycorticosterone in the etiology of hypertension is still unknown.
Journal of Steroid Biochemistry | 1982
J.W. Honour; E.G. Biglieri; K. Lichtwald; D. Haack; P. Vecsei
Metabolites of aldosterone were extracted from human urine collected over three days following the intravenous injection of a tracer dose of tritium labelled hormone. After enzymic hydrolysis, steroids were separated by column, paper and thin-layer chromatography and the polarities of the labelled metabolites were compared with the chromatographic properties of known aldosterone products. The pattern of metabolites changed over the three days, from that associated with typical aldosterone metabolites, to less polar metabolites. Materials in the organic extract from a pH-1 hydrolysate of pooled pregnancy urine, were located by their ability to bind with aldosterone and tetrahydroaldosterone antisera and exhibited similar chromatographic properties to the radioactive metabolites. Using GC-MS, the identity of this immunoactive material could not be established in extracts after purification from 200 ml pregnancy urine but some synthetic derivatives of aldosterone as candidate compounds, were excluded.
The Journal of Clinical Endocrinology and Metabolism | 1982
Károly Rácz; Ibolya Varga; E. Glaz; Róbert Gábor Kiss; Sandor Vida; Gyorgyi Lada; Katalin Di Gleria; K. Medzihradszky; K. Lichtwald; P. Vecsei
Journal of Steroid Biochemistry | 1982
M. Lis; D. Haack; C. Maser; P. Vecsei; K. Lichtwald
Journal of Steroid Biochemistry | 1982
A. Rösler; A. Milewicz; S. Korth-Schlitz; D. Haack; K. Lichtwald; P. Vecsei