Biomedical subjects
Publications and source records attributed to J Müller.
The scope and limitation of some recent acylation methods were investigated as applied to the preparation of steroidal esters of highly hindered acids. As representative steroids, 19-nor-17 alpha-ethinyl testosterone (19-NET) and testosterone, and as representative acid, pivalic (trimethylacetic) acid were used.
The temporal relation between alterations in serum aldosterone and in the conversion of labelled corticosterone to aldosterone by incubated adrenal tissue was studied in conscious rats receiving long-term infusions of KCl, ACTH or angiotensin II. When potassium-deficient rats were given KCl, a marked increase in serum aldosterone was observed only after 12 h, i.e. at a time when the conversion of corticosterone to aldosterone had become normal. After 24 h of ACTH infusion into sodium- and potassium-replete rats the serum aldosterone was markedly elevated, whereas the conversion of corticosterone to aldosterone was significantly decreased. After 48 h of continued ACTH infusion the serum aldosterone returned to normal and there was a further decrease in the conversion rate. A 24-h angiotensin II infusion into sodium- and potassium-replete rats induced significant increases in both the serum aldosterone and the conversion. After 48 h of continued angiotensin infusion the serum aldosterone returned to normal while the conversion and the blood pressure remained elevated. These results indicate that the activity of the enzymes involved in the final steps of aldosterone biosynthesis may become rate-limiting for the secretion of aldosterone during potassium deficiency and during prolonged ACTH treatment. On the other hand, the observed transiency of aldosterone stimulation by exogenous angiotensin II was not due to a suppression of the final steps of aldosterone biosynthesis and remains unexplained.
After epicutaneous application of Hedolit to guinea pigs the above mentioned substance was found less concentrated in the semen and in the testis than in the serum. Hedolit concentrations, as they were found in the serum, lead already to motility limitations of human sperma and cause a small mutageneous effect in drosophila melanogaster. The chosen epicutaneous modus of application did not lead to such traceable concentrations of Hedolit in the semen and in the testis.
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In a group of subjects with a normal as well as pathological thyroid function there was a significant increase in RT3U, serum-thyroxine-concentrations and TSH-levels but there were no significant changes in the T4-RT3U-indices and ETR-tests after 5 min of venous compression. The discordant results were obtained in 21 cases (26.9%) with the RT3U-test and in 4 cases (5,1%) with the T4-serum-level-determination, which may cause diagnostic errors. The non-standardized venous compression time causes a widening of the euthyroid zone which reduces the discrimination capabilities of these function tests. With TSH-determinations these deviations may be of diagnostic importance in the evaluation of TRH-TSH-test results. A standardized and minimum compression time when drawing blood samples is recommended in order to eliminate this potential source of diagnostic error.
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A pituitary-dependent Cushing's syndrome in a young woman had an unusually protracted course and was extremely resistant to therapy. After unsuccessful pituitary irradiation, bilateral total adrenalectomy was performed. A piece of an excised adrenal gland was reimplanted into a buttock. Nevertheless, the patient went into adrenocortical failure and had to be given replacement therapy. After three years the Cushing's syndrome reappeared, this time combined with general hyperpigmentation. The implanted adrenal tissue was no longer to be found. Neither stereotactic pituitary coagulation nor implantation of 90-Yttrium into the pituitary resulted in remission of Cushing's syndrome. All attempts to localize the--very probably ectopic--cortisol-producing adrenocortical tissue failed. However, complete remission was finally achieved by treatment with o,p'-DDD.
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Ammoniated straw pellets were produced from pure wheat straw in a pelleting press reaching temperatures of more than 90 degrees C, 4% NH4HCO3 being added as degradation agent. Digestibility trials with sheep gave 389 energetic feed equivalents (cattle) per kg straw dry matter. This value exactly agrees with the formula Energetic feed equivalents (cattle)/kg DM = 650 -6x x = % crude fibre in dry matter which had been reported first in 1973 by Bergner and Marienburg (Arch. Tierernährung 23, 423 [193]) for chemically treated straw pellets. When testing the digestibility of the same straw pellets charge in the Animal Nutrition Division of the Dummerstorf-Rostock Research Centre for Livestock Production, considerably lower values were found which would allow to calculate energy concentration to amount to 310 energetic feed equivalents (cattle)/kg DM (see Arch. Tierernährung Vol. 28, page 393). The reason for this 20% lower feed value of the straws pellets lies possibly in the reversibility of the degradation effect when using ammoniacal media. The digestibility of the straw pellets had been tested in the Berlin research Institution one year earlier than at the Rostock Institute. The possible causes of the reversibility of the ammoniacal degradation effect are discussed.
The treatment of rats with a high dose of ACTH resulted within 4 days in a marked suppression of aldosterone and deoxycorticosterone outputs by capsular adrenal tissue ("zona glomerulosa") incubated with and without serotonin and in decreased conversions of tritiated corticosterone and deoxycorticosterone to aldosterone and 18-hydroxycorticosterone, but in strikingly increased capsular adrenal conversions of tritiated deoxycorticosterone to corticosterone and 18-hydroxy deoxycorticosterone. ACTH also suppressed aldosterone biosynthesis in rats kept on a sodium-deficient diet. Corticosterone or dexamethasone, when added to the drinking fluid for 2 weeks, induced only small decreases in aldosterone biosynthesis from endogenous or exogenous precursors. Moreover, they significantly decreased the capsular adrenal conversion of added deoxycorticosterone to corticosterone and 18-hydroxydeoxycorticosterone. These results indicate that during prolonged ACTH treatment, the zona glomerulosa cell may be converted to a functional zona fasciculata type of cell. High levels of circulating mineralocorticoids and glucocorticoids seem to be minor contributory factors in the long term suppression of aldosterone biosynthesis by ACTH.
Methyl 4-hydroxy-3-nitrobenzimidate hydrochloride (I) is presented as a newly developed amidination reagent. It is synthesized in two steps from commercially available 4-hydroxybenzonitrile. Its incorporation into proteins can be easily determined spectroscopically. The activities of the three enzymes lactate dehydrogenase (pig heart), alkaline phosphatase (calf intestine) and tryptophan synthase (E. coli) were not greatly reduced after modification with the reagent. The nitro groups can be reduced by mild treatment with Na2S2O4 without alteration of the enzymatic activity. The newly formed aromatic amino groups can further be made to react at lower pH than the native amino groups.
In a selected group of fifty-one persons suspected to be hyperthyroid the comparison between a shortened variant of TRH-TSH stimulation test and thyroid suppression test was made. In patients whose other functional tests gave no univocal results, the agreement between suppressibility of radioiodine uptake and TSH response in 90,2% of cases could be established. High degree of correlation between both parameters (coefficient V = 0.791) permits to regard these tests as practically equivaluablein giving evidence of dysregulation between pituitary and thyroid gland. In persons with TSH-dependent thyroid function, however, no correlation between numerical values of radioiodine uptake and TSH concentrations after stimulations was found.
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