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Biomedical subjects

K Günther

Publications and source records attributed to K Günther.

At least 109 records · Page 6Linked to original sources
PubMed1986

[Comparative studies of calcium resorption modified by vitamin D2 and D3 in patients with chronic renal failure and dialysis patients].

In 16 patients with a chronic renal insufficiency at the stage of the compensated retention and 13 test persons of the chronic haemodialysis programme determinations of the total calcium and of the ionized calcium fraction as well as investigation of the intestinal calcium absorption by means of the isotope 47Ca were performed. In these cases the influence of vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) on these parameters of the calcium metabolism was compared. Under the treatment with vitamin D a normalization of the serum calcium levels concerning the total calcium concentration as well as with regard to the ionized calcium fraction was achieved; this effect took place parallel to the improvement of the intestinal calcium absorption. Vitamin D3, had a more favourable effect than vitamin D2. The necessary doses are below 40,000 U a day.

Blood Urea Nitrogen↗
PubMed1986

[Desferal treatment of aluminum poisoning; effect on serum concentrations of aluminum (Al), iron (Fe) and copper (Cu)].

In 2 patients with a progressive dialysis encephalopathy and increased serum aluminium concentrations a Desferal-treatment with 500 mg per week was performed and in these cases the kinetics of Al, Fe, Cu was investigated. After the application of Desferal an increase of the serum levels, the ultrafiltrable proportion, the dialysance and the eliminated quantity of aluminium developed. In the course of the treatment in the two patients the aluminium level could be reduced to approximately normal values. Nevertheless one patient died of a severe course of a progressive dialysis encephalopathy. An increase of the copper concentration independent of Desferal-treatment after the dialysator passage remained without influence on the course of concentration of the serum copper in the examination period. A remarkable effect of the Desferal-therapy on the iron metabolism could not be established. Since in the dosage used there did not appear any side effects the Desferal-application is to characterized as a distinct and effective technique for the decrease of the serum-aluminium-concentration in patients undergoing dialysis.

Adult↗
PubMed1986

[Histochemical localization of aluminum deposits in bones and their relation to the clinical and histomorphometric findings in patients with chronic renal failure].

In 60 patients with chronic renal insufficiency and 36 dialysis patients an iliac crest biopsy was performed, on the undecalcified bone morphometric determinations were carried out as well as the aluminium deposition was investigated histochemically. Histologically were found in 3 patients normal findings, in 11 patients a fibroosteoclasia, in 23 patients an osteoidosis and in 59 patients a combination fibroosteoclasia and osteoidosis. 3 oft the 60 patients with a chronic renal insufficiency had aluminium depositions in the polyblasts. Of the 36 dialysis patients 19 (55.4%) had a positive aluminium histology: 30.7% of the patients with osteoidosis and 23.7% with a mixed form. There was a positive correlation to the bone and osteoid volume, to the osteoid surface and a negative relation to the activity of osteoblasts, the absorption surface and the activity of osteoclasts. Aluminium depositions on the mineralisation border might be of importance for the changes.

Adolescent↗
PubMed1985

Application of chromatographic chiral stationary phases to pharmaceutical analysis. Enantiomeric purity of D-penicillamine.

The enantiomeric purity of the pharmaceutical D-penicillamine (I) has been determined by a novel high-performance liquid chromatographic technique involving the formation of 5,5-dimethylthiazolidine-4-carboxylic acid (III) by reaction of I with formaldehyde and separation of the optical antipodes by means of ligand exchange chromatography using the copper(II) complex of (2S,4R,2'RS)-4-hydroxy-1-(2'-hydroxydodecyl)proline, which is coated on a reversed-phase column. The limit of determination for the L-antipode is ca. 0.1%. The validation of the method is accomplished by comparison with an independent gas chromatographic procedure. Thirteen commercially available lots of I are shown to be of equally high enantiomeric purity (ca. 99.9%).

Chromatography, Gas↗
PubMed1985

Nuclear medicine liver-function tests for pregnant women and children. 2. A new test method via urine using 15N-methacetin.

A simple, non-invasive, non-radioactive liver-function test is proposed. After an oral dose of 3 mg 15N-methacetin per kilogram body mass, the kinetics of 15N excretion via urine were characterized by the quotient of the amounts of 15N excreted in two successive urine samples (Q value). The stable nitrogen isotope 15N was found to be an excellent and easily detectable indicator of the sum of all methacetin metabolites present in urine. Alterations in the nature or ratio of methacetin metabolites due to liver diseases could not be found. From the investigation of 11 men, 3 pregnant women and 15 children, a clear difference was observed in Q values of healthy persons and patients suffering from liver-cell-activity diseases. The discriminating power of our new liver-function test is shown to be equivalent to that of the 14CO2 breath test.

Acetamides↗
PubMed1985

Nuclear medicine liver function tests for pregnant women and children. 1. Breath tests with 14C-methacetin and 13C-methacetin.

Stable isotopes, such as 13C, should be substituted for the long-lived radionuclide 14C in the 14C breath test when doing liver function tests in children and pregnant women. For comparison 13C, 15N-methacetin and 14C-methacetin were synthesized as suitable diagnostic agents. Methods are described for the measurement of 14C and 13C in the breath. After oral administration of labelled methacetin to healthy subjects and patients with liver diseases a good correspondence between 13C- and 14C-measurements in the same subject on the one hand, and a good discrimination between controls and patients on the other hand were shown. Findings with regard to 14C measurements in urine are discussed supporting the supposed advantage of 13C-methacetin over 14C-methacetin application.

Acetamides↗
PubMed1985

Two-pool model analysis of data in hemodialysis by means of programmable pocket calculator TI 59.

Four parameters of a two-pool model are evaluated by an iterative method using the explicit solutions of the linear differential equations. For this it was presumed that the residual renal clearance is sufficiently small. Five data pairs of measured plasma concentrations ci for the time points ti (i = 0 to 4), as well as the dialyzer and residual renal clearances (KD and KR), must be given and put in the calculator. A sample run is shown for urea kinetics. The parameter estimation takes about 10 min. The program is suitable to assist in the individualization of dialysis therapy.

Computers↗
PubMed1985

[The influence of chronic renal insufficiency on the demethylating activities of various cytochrome P-450 subspecies in humans].

Caffeine is mainly metabolized by 3-methylcholanthrene-inducible cytochrome P-450 (P-450MC) and metamizol (noramidopyrine methanesulfonate sodium) is mainly metabolized by phenobarbital-inducible cytochrome P-450 (P-450PB). That's why the half life of caffeine and the elimination of the main metabolites of metamizol were used as parameters in vivo characterizing both groups of the cytochrome P-450-complex. The influence of chronic renal insufficiency was investigated (8 patients in the stage of compensated retention, creatinine in serum 380-1280 mumol X l-1, and 6 hemodialyzed patients, here only metamizol elimination was established). Both the caffeine and the metamizol eliminations of patients with chronic renal insufficiency are not different from those of healthy volunteers. We concluded that the demethylation activity of the cytochrome P-450-complex is not distinctly influenced by chronic renal insufficiency.

Ampyrone↗
PubMed1984

[Diagnosis of vitamin B12 deficiency in chronic kidney insufficiency].

It is difficult to assess the vitamin B12 metabolism in chronic renal insufficiency. In varying numbers out of a total of 88 nephropathy patients with varying degrees of insufficiency (22 patients without restriction of kidney function, 53 patients with chronic renal insufficiency in the stage of compensated retention and 13 haemodialysis patients) the Schilling test was performed and the serum vitamin B12 level was measured in fasting and 4, 6, 8 and 10 hours after oral administration of 2000 micrograms of vitamin B12. Regardless of the volume of urine, the Schilling test must be treated critically with serum creatinine values between 150 and 300 mumol/l and beyond 300 mumol/l it is no longer of diagnostic value. Serum vitamin B12 measurement after oral administration of 2000 micrograms of vitamin B12 allows vitamin resorption in the ileum to be qualitatively demonstrated on the basis of the curve. In most renal insufficiency patients the serum vitamin B12 level was increased, but this does not exclude the possibility of vitamin B12 deficiency.

Adolescent↗
PubMed1984

[Pharmacokinetics of the sulfonamide-trimethoprim combinations Berlocombin and Sulprim in patients with various degrees of kidney dysfunction].

Patients with normal and decreased kidney function were treated with an initial dose of 4 tablets Berlocombin and following with a dose of 2 tablets for 10 d in a 12 h period. The dialysis patients got only once the initial dose. The kinetic parameters were calculated by means of a one compartment model. Independend on the kidney function the minimum therapeutic serum concentrations of 1 microgram/ml at trimethoprime and of 20 micrograms/ml at the sulphonamides were reached during the first hours after medicament application. At all patients the urine concentration of trimethoprime were some times over the minimum therapeutic concentration. The individually found maintenance doses fluctuate between 2 tablets each 12 h and 1 tablet each 24 h. At patients with serum creatinine levels greater than 3 mg/100 ml (greater than 265 mumol/l) 1 tablet each 12 h is sufficient as maintenance dose. At a higher degree of kidney function decreasing (serum creatinine greater than 6 mg/100 ml (greater than 530 mumol/l] cumulating of the sulphonamide metabolites in the serum is found. The evaluated elimination velocity of the investigated sulphonamides during the hemodialysis was higher than that at patients with normal kidney function. The elimination rate of trimethoprime during the dialysis is in the same region as at patients without any kidney diseases.

Drug Combinations↗
PubMed1983

[In vitro studies on the adsorption of various resins of the Wofatit type for drugs].

The capacities of the resins Wofatit Y 29, Y 55 and Y 56 (VEB Chemiekombinat Bitterfeld) to adsorb various medicaments were compared with that of the resin XAD-4. Methaquelone, diazepam, krotylbarbital, promazine phosphate and ethyloxamine were used as test substances. The resin Y 56 proved to have an adsorption capacity similar to that of XAD-4 (e.g. maximum saturation for methaquelone 98%, half-maximum saturation at 7 minutes). In further tests on various batches of this resin the best results were given by the resin Y 56/7. Adsorption was quite clearly shown to be dependent on concentration. At a blood-flow of 100 ml/min clearance values of 34.5 ml/min for krotylbarbitol and 22.1 ml/min for methaquelone were calculated. According to these findings the resin Y 56/7 is suitable for further testing in a haemoperfusion system with a view to clinical use.

Barbiturates↗