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F K Ohnesorge

Publications and source records attributed to F K Ohnesorge.

At least 37 records · Page 2Linked to original sources
PubMed1987

Aluminum load in chronic intermittent plasma exchange.

Aluminum (Al) loading due to administration of human albumin (HA) solutions was studied in 2 patients with stable renal function who underwent plasma exchange once (patient A) and twice (patient B) per week for treatment of hyperviscosity syndrome. Al was determined by Zeeman-AAS in plasma before, during and after treatment, also in bone of one patient and in various preparations of HA from different manufacturers. In addition, the net Al uptake (difference between total Al influx and efflux) and the 24th urinary excretion between 2 exchanges were determined. The electrolyte solution used for dilution had no detectable Al, while HA contained between 15 and 1900 micrograms Al/l. Increase of Al in plasma after treatment was clearly related to Al content of the HA used. When the patients received substitution solutions based on inadvertently highly Al contaminated 20% HA (1419 micrograms/l), the average net uptake was 2265 in patient A and 2049 micrograms in patient B and plasma Al rose from 8.4 respectively 18.0 before to 69.2 and 86.5 micrograms/l after treatment. By using medium Al contaminated HA (574 micrograms/l), the net uptake was 742 (pat. A) and 819 micrograms (pat.B), and there was an elevation of plasma Al from 5.1 respectively 18.2 to 34.2 and 39.8 micrograms/l. Following a net uptake of 870 micrograms patient A excreted 668 micrograms Al until the next treatment (23% positive balance). Treating patient A with a low Al HA (47 micrograms/l), there was a slight increase of plasma Al from 10.8 to 16.2 micrograms/l, the net Al uptake was negligible (less than 10 micrograms), and the weekly Al balance was negative. After 10 months of plasma exchange therapy (patient A) there was no increase of Al in bone (6.4 micrograms/g). We conclude, that the use of HA with a low Al contamination is recommended for all patients receiving this therapy during chronic intermittent plasma exchange or for other indications, especially in cases with impaired renal function.

Adult↗
PubMed1986

Absorption and distribution of cadmium (Cd), copper and zinc following oral subchronic low level administration to rats of different binding forms of cadmium (Cd-acetate, Cd-metallothionein, Cd-glutathione).

Male Wistar rats received by gavage saline or about 25 micrograms cadmium (Cd)/kg/day as Cd-acetate (Cd-Ac), Cd-metallothionein (Cd-MT) or Cd-glutathione (Cd-GSH) 5 times per week for 28 times. At all treatments 0.2-0.3% of the totally administered Cd dose was found in liver, kidneys, small intestine and pancreas, whereas none of the Cd forms applied resulted in a Cd accumulation in testes. Cd in small intestine was not increased by Cd-MT. However, it was raised by Cd-Ac and even more by Cd-GSH. A smaller increase in hepatic and renal Cd resulted from Cd-GSH than from Cd-Ac or Cd-MT. Cd in pancreas increased after Cd-GSH but not after Cd-Ac or Cd-MT. Copper (Cu) rose in small intestine and testes but decreased in kidneys independent of either Cd treatment. Concomitantly, zinc (Zn) was decreased in small intestine and testes. The tissue concentration of metallothionein (MT) was only marginally increased by all treatments. The highest value (80%) above controls) was found in small intestine after Cd-GSH. Intestinal Cd as well as testicular Cu were related to the tissue MT. Therefore, the distribution of Cd between various organs depends on the Cd form applied. There is some relationship to the distribution of Cu and Zn.

Acetates↗
PubMed1984

Cadmium-induced alteration of the energy level in isolated hepatocytes.

The incubation of isolated hepatocytes with 10-100 microM cadmium (Cd) decreased the ATP/ADP-ratio, the ATP/AMP-ratio and the adenylate energy charge and enhanced the lactate/pyruvate-ratio in a time- and concentration-dependent manner. Likewise, the cellular oxygen-consumption was decreased at early incubation times, when the cell membrane was still intact, as judged by the Trypan Blue-exclusion test. Similarly, Cd-concentrations above 0.3 nmol/mg mitochondrial protein inhibited the succinate- and malate/pyruvate-stimulated respiration of isolated mitochondria. This critical concentration was also reached in mitochondria of hepatocytes, when exposed to 25 microM Cd for less than 30 min. We therefore suggest that the inhibition of cellular respiration and the breakdown of cellular energy generation is mediated by a severe disturbance of mitochondrial respiratory functions due to Cd. This effect seems to be an early event in Cd-toxicity in isolated hepatocytes.

Adenine Nucleotides↗
PubMed1984

The kinetics of bupivacaine (Carbostesin) plasma concentrations during epidural anesthesia following intraoperative bolus injection and subsequent continuous infusion.

Plasma levels of bupivacaine were measured in 25 patients undergoing major abdominal surgery. The pharmacokinetic analysis of these data shows: (1) under a short term treatment, i.e. in the initial phase where multiple injections are given, the kinetic properties are in accordance with linear kinetic theory. The data can best be fitted to a two-compartment-model. (2) under a longterm treatment, i.e. infusion for more than 50 h, a very high accumulation occurs in contradiction to this theory. Therefore, the calculation of plasma levels from initial kinetic data is not feasible.

Adult↗
PubMed1982

Different response of liver parenchymal cells from starved and fed rats to cadmium.

The susceptibility of hepatocytes to the deleterious effects of cadmium (10-100 microM Cd), as evidenced by SH-group content and cell membrane permeability for Trypan Blue (TB), was shown to be strongly dependent on the dietary condition of the donor animal. Although Cd stimulated lipid peroxidation (LPO) equally well in "starved" as in "fed cells", SH-group content and TB-exclusion decreased markedly only in "starved" cells exposed to Cd. Experiments with methionine + serine and/or the antioxidant (+)-cyanidanol-3 suggested that the Cd-dependent LPO proceeded independent of the decrease in SH-group content or TB-exclusion.

Animals↗
PubMed1982

Induction by 3-methylcholanthrene of microsomal cytochromes and enzyme activities in mouse liver after subchronic ingestion of cadmium chloride.

The dose-dependence of the effect of Cadmium chloride (Cd) on the induction by 3-methylcholanthrene (MC) of the microsomal cytochromes b5 and P-450, seven monooxygenase activities and the arylepoxide hydrase was investigated in the livers of male random bred mice (NMRI Hannover). The animals were treated with 6.0; 3.0; 1.0 and 0.3 mumoles Cd++/kg/day for 20 days and subsequently with MC for three days (20 mg MC/kg/day). Cytochrome P-450 of control animals receiving MC only was not induced, and presumably kinetic inhibition of three monooxygenase activities was observed at the highest Cd-dosage. However, treatment with the two intermediate Cd-dosages resulted in induction by MC of both microsomal cytochromes and of 5 hydroxylating activities, leaving unaffected only the arylhydrocarbon hydroxylase. Previous work had shown that Cd alone in this dose range is without effect on microsomal enzymes. Therefore, Cd exerts a stabilizing or permissive effect on the phenotypic expression of some microsomal enzymes, but not of the arylhydrocarbon hydroxylase, within the MC-dependent induction process in mouse liver.

Animals↗
PubMed1979

Additional induction of microsomal cytochrome(s) P 450 in mouse liver by consecutive application of cadmium chloride and phenobarbital.

Mice were treated intraperitoneally over 20 days with 0,30; 0,10 and 0,03 mg Cd+2/kg.day. Subsequent induction of microsomal metabolism by 50 mg phenobarbital/kg.day over 5 days revealed increased microsomal cytochrome P 450 content in Cd+2-pretreated animals as compared to animals treated only with phenobarbital. The microsomal cadmium content of animals having received cadmium plus phenobarbital was about 5 times higher than that of animals treated with cadmium alone. The only enzyme activity found to be changed by cadmium in induced microsomes was ethylmorphine-N-deethylation. In phenobarbital-free animals no microsomal changes by cadmium could be detected.

Animals↗
PubMed1976

Effects of cadmium on carbonic anhydrase activity and hemoglobin content of rat testes.

The cadmilm-induced (Cd) damage of mammalian testes is thought to be correlated with an inhibition of carbonic anhydrase (CAH) by Cd. Since Cd causes dose-dependent changes in blood flow of the testes, an inhibition of CAH in the testes could be simulated by a decrease of CAH-rich erythrocytes. Therefore, CAH activities and hemoglobin (Hb) content were determined in blood and testes of untreated and Cd-treated Sprague-Dawley rats as well as in testes perfused via the testicular artery. Cd was intraperitoneally applied as CdCl2 in single doses of 1.5, 3.0, and 5.0 mg Cd2+/kg b.w., respectively. 1. The experiments on perfused testes clearly demonstrated that the CAH activities originate from erythrocytes rather than from a tissue located enzyme. 2. The alterations in blood circulation occurring shortly (0.25-1.0 h) after the Cd administration were characterized by a dose-dependent, transient decrease (1.5 mg Cd2+/kg) as well as an increase (3.0 and 5.0 mg Ck2+, respectively) of the Hb content in the testes. 3. Independent of these minor alterations in a later state (14-24 h after 1.5 mg Ck2+/kg, 7-14 h after 3.0 mg Cd2+/kg, and 1-3 after 5.0 mg Cd2+/kg), Cd induced the well known hemorrhagic alterations of the testes with a high increase of Hb content and CAH activity. 4. By means of the correlations between CAH activities and Hb content in blood and testes an inhibition of the CAH by Cd as the primary cause for the tissue damage of the testes could largely be excluded.

Animals↗
PubMed1975

Studies on acetylcholinesterase and cholinesterase covalently bound to polymaleinic anhydride.

Acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) and cholinesterase (acylcholine acylhydrolase, EC 3.1.1.8), respectively, were covalently attached to a cross-linked copolymerisate of maleinic anhydride and butanediol-divinylether. Based on the coupling procedure reported by Brümmer et al. (Brummer, W., Hennrich, N., Klockow, M., Lang, H. and Orth, H.D. (1972) Eur. J. Biochem. 2k, 129--135), a simple method is described which requires only 24 h for completion and provides a sufficient yield. Although a polyanionic carrier was used the Km and k2 values as well as the substrate and pH optima of the bound acetylcholinesterase and bound cholinesterase did not differ considerably from the corresponding values of the free enzymes. Bound acetylcholinesterase and to some extent also bound cholinesterase did not lose any enzymatic activity after storage in saline at 4 degrees C for 140 days.

Acetylcholinesterase↗