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H Kropp

Publications and source records attributed to H Kropp.

45 records · Page 3Linked to original sources
PubMed1972

Cephamycins, a new family of beta-lactam antibiotics. IV. In vivo studies.

Cephamycin A was found to be more active in vivo than cephamycin B. In comparison with cephamycin C, cephamycin A was more active against gram-positive organisms but less active against gram-negative organisms. Given subcutaneously, cephamycin C had good in vivo gram-negative activity, comparing favorably with cephalothin and cephaloridine against cephalosporin-susceptible organisms. In general, against the gram-negative organisms, it was more active than cephalothin or cephalosporin C and about as active as cephaloridine. In addition, cephamycin C protected mice against beta-lactamase-producing Proteus cultures, including clinically isolated strains. The compound is remarkably nontoxic. Cephamycin C was detected in the serum and recovered from the urine of treated mice to about the same extent as cephaloridine. Like cephaloridine and cephalosporin C, cephamycin C must be excreted mainly by glomerular filtration, because the use of probenecid did not enhance the therapeutic effectiveness nor concentrations of these agents in the sera of treated mice.

Animals↗
PubMedDate not supplied

[Prevention of cytomegalic inclusion disease in leukemia patients with a cytomegalovirus hyperimmune globulin preparation].

In a randomised study the efficacy of a cytomegalic hyperimmune globulin preparation (CMV-HIGP) which had been treated with beta-propiolactone was analysed. The study included 85 patients with acute lymphoblastic leukemia (ALL) and Non-B-Non-Hodgkin-lymphoma (NHL) who were treated initially or underwent a relapse therapy. During the intense chemotherapeutical period within leukemia treatment the patients were passively immunised by the intravenous route with CMV-HIGP (1 ml per kilogram of body weight) every two to three weeks at the latest. In the initial stages the basic immunisation protection was achieved by the application of double dose CMV-HIGP. The Frankfurt patients were recruited from the BFM-ALL- and the NHL-study since october 1982. When they were admitted their CMV serostatus was determined by means of the ELA-ELISA or IFA-method. Seronegative patients were given the passive immunisation immediately or 48 hours after the first blood transfusions at the latest. The patients who had become CMV-IgG-positive by passive immunisation were randomised when reaching long-term therapy according to the protocol. Because of a 30% cytomegaly disease incidence rate in our patient population a randomisation was unwarrantable at the beginning of leukemia treatment. During randomisation one group of patients were immunised by the intravenous route with CMV-HIGP (2 ml per kg body weight one time in four weeks), the second group was a control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMedDate not supplied

Antibacterial activity of imipenem: the first thienamycin antibiotic.

Imipenem (N-formimidoyl thienamycin) is the first representative of a new class of beta-lactam antibiotics--the carbapenems. Imipenem has an unusually broad spectrum, high potency, and no cross-resistance with other beta-lactam antibiotics. Susceptible gram-negative species include Pseudomonas aeruginosa, Serratia, and Enterobacter. Activity is high against Staphylococcus aureus, most group D streptococci, and Staphylococcus epidermidis but is variable against methicillin-resistant S. aureus. Imipenem is more active against Bacteroides than are other beta-lactam agents, chloramphenicol, metronidazole, and clindamycin. The minimal inhibitory concentrations (MICs) for 98% of 30,655 isolates--excluding those of the three resistant species (Pseudomonas maltophilia, Pseudomonas cepacia, and Streptococcus faecium)--were less than 8 micrograms/ml, the susceptibility breakpoint adopted for clinical trials. Imipenem is bactericidal (minimal bactericidal concentrations (MBCs] less than twice the MICs). For P. aeruginosa, MBCs of imipenem are less influenced by high inoculum density rather than are MBCs of antipseudomonal penicillins and cephalosporins. Stability of imipenem to diverse classes of plasmid-mediated and chromosomal beta-lactamases accounts for its lack of cross-resistance with other beta-lactam antibiotics. Imipenem is also active against P. aeruginosa with non-lactamase-mediated resistance to classical beta-lactam agents. Efficacy of imipenem was shown in animal models, including septicemia in normal and neutropenic rodents and P. aeruginosa pneumonia. Imipenem also has a unique postantibiotic effect against P. aeruginosa in vivo.

Aminoglycosides↗
PubMedDate not supplied

Oxidative and defluorinative metabolism of fludalanine, 2-2H-3-fluoro-D-alanine.

The antibacterial agent fludalanine [2-2H-3-fluoro-D-alanine (DFA)] is a potent inhibitor of bacterial alanine racemase, an enzyme required for the generation of D-alanine, an essential component of the bacterial cell wall. Primary metabolism of DFA involves its oxidation to fluoropyruvate (FP); this organic fluoride is then rapidly reduced to fluorolactate (FL) which is the major organic metabolite in laboratory animals. Gas-liquid chromatographic chemical ionization mass spectrometric assays were developed for these two metabolites. FL is the predominant organofluoride metabolite of DFA in the circulation. FP was detected in the urine although recovery was very low. The rapid conversion of FP to FL precludes assay of the former in serum. Maximum serum FL concentrations in the rat appear about 1 hr after the dose of DFA and are relatively constant for several hours thereafter. The peak FL concentration is proportional to the dose of DFA; repeated daily dosing of DFA appears to cause neither saturation nor induction of metabolic pathways. Comparison of FL concentrations determined using the GC/MS assay with those based on an enzymic method specific for L-(+)-FL demonstrated that only the latter isomer is found in the plasma of monkeys dosed with DFA. In vivo exchange studies involving the alpha-proton of FL indicate that a small FP pool exists and is in equilibrium with FL. A crude pyruvate dehydrogenase complex isolated from beef heart mitochondria was shown to produce equimolar quantities of acetate, CO2, and fluoride from FP.

Alanine↗