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Biomedical subjects

H Fricke

Publications and source records attributed to H Fricke.

90 records · Page 5Linked to original sources

Effect of demycarosylturimycin on ribosomal peptidyltransferase from Escherichia coli.

The effect of demycarosylturimycin H on bacterial growth, polypeptide synthesis and peptidyltransferase was studied. The effects are compared with those of intact turimycins acylated or deacylated in 4''-position of mycarose. The removal of the acyl group in 4''-position of mycarose leads to a total loss of inhibition of acceptor substrate binding while the removal of acyl mycarose moiety changes the pattern of inhibition of polypeptide synthesis.

Acyltransferases↗

Effect of the leucomycin-like macrolide antibiotic turimycin on ribosomal peptidyltransferase from Eschericha coli.

The relationship between the effect of different turimycin components on ribosomal peptidyltransferase of E. coli, antimicrobial activity and chemical structure were studied. Inhibition of peptidyltransferase as well as antimicrobial activity increased with the length of the aliphatic side chain in 4''-position of mycarose and decreased with acylation in 3-position of the lactone ring. Inhibition of peptidyltransferase is paralleled by inhibition of acceptor substrate binding.

Acyltransferases↗

[Pharmacokinetics and metabolism of the antiinflammatory agents S-H 766 in man].

Blood and plasma levels as well as urinary and fecal excretion were measured in humans after oral administration of radioactively labelled 4-[j-(2'-fluorobiphenylyl)]-4-hydroxycrotonic acid (S-H 766 MO). The radioactivity in the plasma reaches maximum values of about 10 mug eq./ml 1 to 2 h after application with either form. After repeated administration good agreement is found between the plasma levels measured and those simulated according to the pharmacokinetic parameters obtained after single application. The S-H 766 metabolites were investigated in blood and urine. The substance was found to undergo considerable metabolism, only approximately 2% being excreted in the urine unchanged. The conjugates, which constitute over 60% of the radioactivity of the urine, consist mainly of glucuronides and sulfates. The structure of the aglycones shows that the metabolism occurs along two pathways, by beta-oxidation of the aliphatic side chain into aryl acetic acids and by hydroxylation of the aromatic nucleus to phenolic compounds. It must be assumed that these biotransformations take place both simultaneously and successively.

Adolescent↗

Conversion of radiolabelled ethanolamine plasmalogen into the dimethylethanolamine and choline analogue via transphosphatidylation by phospholipase D from cabbage.

Starting from biosynthetically prepared ethanolamine plasmalogen 14C-labelled in the O-alkenyl moiety, choline and dimethylethanolamine plasmalogen were prepared by transphosphatidylation utilizing phospholipase D from cabbage. Investigation of the time course of the reaction showed that transphosphatidylation was simultaneously accompanied by hydrolysis of both the substrate and the desired product, resulting in a maximum of product yield after 1-3 h under the reaction conditions investigated. Optimal reaction conditions gave yields of 40% and 62% (of total radioactivity) respectively for the purified choline and dimethylethanolamine derivatives.

Animals↗

Inflammatory demyelinating neuropathy in patients with end-stage renal disease receiving continuous ambulatory peritoneal dialysis (CAPD)

OBJECTIVE: To report on 3 patients with inflammatory demyelinating peripheral neuropathy in strong temporal coincidence with the initiation of peritoneal dialysis (PD) therapy. SETTING: Nephrology and Neurology Department of the University Hospital, Munich, Germany. PATIENTS: Three patients with end-stage renal failure presented with the clinical picture of inflammatory demyelinating peripheral neuropathy within 4 to 10 weeks after start of continuous ambulatory peritoneal dialysis (CAPD). They had acute or subacute onset of lower extremity or generalized weakness, diminished reflexes, elevated spinal fluid protein levels, and signs of demyelinating neuropathy on electrophysiological testing. MEASURES: Clinical follow-up, nerve conduction studies, cerebral spinal fluid (CSF). RESULTS: All patients did not improve under intensified PD therapy but took profit from immunomodulatory therapy. One bed-bound patient improved after change to hemodialysis and showed complete remission after renal transplantation. CONCLUSION: Because of strong temporal coincidence, a causal relationship between CAPD and inflammatory demyelinating peripheral neuropathies can be suspected in these 3 patients.

Adult↗