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M Scheer

Publications and source records attributed to M Scheer.

At least 55 records · Page 3Linked to original sources
PubMed1978

Binding of aminoglycoside antibiotics to human serum proteins. III. Effect of experimental conditions.

The binding of several aminoglycoside antibiotics to human serum proteins was studied under varying experimental conditions. The protein binding was determined by means of equilibrium dialysis and, with sisomicin and gentamicin, also by the ultracentrifuge method in the presence and in the absence of Ca++ and Mg++ ions. The technical experimental procedure (dialysis, ultrafiltration, ultracentrifugation) has no effect on protein binding contrary to the physico-chemical conditions (varying concentrations of Ca++ and Mg++ ions). Under experimental conditions closely conforming to physiological conditions, the aminoglycosides of the kanamycin and neomycin series are not bound by the serum proteins, independent of the assay method used, whereas streptomycin is bound under these conditions. In the absence of divalent cations all the aminoglycosides studied were bound by the serum proteins to varying degrees; the fewer the OH groups contained in the aminoglycoside molecule the greater the rate of protein binding. At equal protein concentration, the albumin fraction of the serum has as great a binding capacity for sisomicin as gamma globulin. Alpha-1 and beta-1 globulin, however, are unable to bind sisomicin.

Aminoglycosides↗
PubMed1976

Pharmacokinetics of sisomicin in patients with normal and impaired renal function; its efficacy in urinary tract infection.

Serum concentration, biological half-life, distribution space and serum clearance of sisomicin, a new aminoglycoside antibiotic, have been studied in twenty-three patients in comparison with the pharmacokinetics of 125I-labelled iothalamate, a compound only filtered by the kidney. 10 patients had normal or borderline abnormal serum creatinine (less than 1,5 mg/100 ml), 8 had various degrees of renal insufficiency (serum creatinine 1.7-9.6 mg/100 ml) and 6 were being treated by intermittent haemodialysis. After intravenous injection of sisomicin 1 mg/kg body weight in patients with normal or borderline renal function its half-life was 3.5 h, very similar to that of iothalamate, 3.2 h. The mean distribution space was 20.1% per cent of body weight; iothalamate, 23.7%. In patients with renal insufficiency there was a positive correlation between serum creatinine level and the half-life of sisomicin, and an even stronger correlation between the clearances of iothalamate and sisomicin. In patients dependent on haemodialysis, the mean serum half-life between dialysis was 40 h, compared to approximately 100 hours for iothalamate, which implies additional extrarenal clearance or tubular secretion of sisomicin. The results of pharmacokinetic studies indicated that a regime of sisomicin 1 mg/kg every 8 to 12 hours in patients with normal renal function would result in serum and urine levels sufficiently high to treat most urinary tract infections. In patients with impaired renal function the dosage interval should be increased according to the serum creatinine level, and in patients dependent on haemodialysis one standard dose at the end of each dialysis period should suffice. 9 patients with a chronic urinary tract infection severely complicated by an underlying disease were treated according to this dosage regimen with a satisfactory bacteriological and clinical result. No adverse reactions or signs of accumulation were observed.

Adult↗
PubMed1976

Metabiolic products of microorganisms. Tirandamycin B(author's transl).

Streptomyces flaveolus, strain Tü 1240 produces besides Tirandamycin A, a hitherto unknown antibiotic, which is closely related to Tirandamycin A. The new antibiotic Tirandamycin B contains one additional hydroxylgroup. Both antibiotics exhibit a similar antimicrobial spectrum and they seem to have the same mechanism of action. According to the data obtained from mass spectrometry, 13C-and 1H-NMR spectra formula II could be deduced for Tirandamycin B.

Aminoglycosides↗
PubMed1976

[Binding of sisomicin and gentamicin to serum proteins (author's transl)].

The binding of sisomicin and gentamicin to the proteins of human serum was investigated by the dialysis method at 37 degrees C. The antibiotic concentrations were determined by the disc diffusion assay as well as by measurements of the optical rotation of the antibiotics in the buffer solutions. Serum was dialyzed against buffer solutions to obtain the standards for the antibiotic assay with regard to the electrolytical exchange at dialysis. In studies on protein binding of sisomicin and gentamicin no measurable binding to human serum proteins could be found, neither in the therapeutically possible concentrations nor at higher ones. Therefore a different binding of the two antibiotics cannot be the reason of the advantage of sisomicin over gentamicin in tests in vivo with animals described in literature nor of its higher activity against several bacterial strains of different species tested in the presence of serum.

Anti-Bacterial Agents↗
PubMed1976

[Antibacterial activity of sisomicin in comparison with gentamicin].

The antibacterial activity of sisomicin -- a new aminoglycoside antibiotic -- as compared with gentamicin was tested on 521 bacterial strains of different species in a serial-dilution test. Staphylococci, streptococci, E. coli, Klebsialla-Enterobacter, indole-psitive Proteus strains, pseufomonads, Salmonads, Salmonellae, and Serratia marcescens were inhibited to the extent of 100% at a maximun of 4.0 mug/ml. Sisomicin showed a higher antibacterial activity against part of the bacterial species. Gentamicin-resistant pseudomonads and Klebsiella (clinical isolates) were still inhibited to the extent of 42 and 67%, respectively, by sisomicin. In addition to the determination of the MIC values for the use of different liquid media, investigations on the determin ation of the minimal bactericidal concentration (MBC), the effect of serum, pH, and inoculum on the bacterial activity, and investigations on the resistance development in vitro were also carried out.

Anti-Bacterial Agents↗
PubMed1976

[Studies on the excretion of various aminoglycosides in rat milk (author's transl)].

10 mg/kg of strepto-, neo-, kanamycin, genta- and sisomicin were applied s.c. to rats in lactation. After 0.5, 1, 2, 4, 6, 8 and 24 h the animals were milked. The antibacterial concentrations in the milk were determined in comparison to the serum concentrations. Strepto-, neo- and kanamycin showed the highest concentrations in the serum, genta- and sisomicin the highest in the milk.

Aminoglycosides↗