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Biomedical subjects

R Bergmann

Publications and source records attributed to R Bergmann.

At least 109 records · Page 6Linked to original sources
PubMed1982

[Optimization of culture conditions for Acinetobacter calcoaceticus grown on n-alkanes in a laboratory fermenter].

The growth conditions for the cultivation of Acinetobacter calcoaceticus in a commercial laboratory fermenter have been optimized. This was done taking former results of shake cultures as a basis. At the end of the logarithmic phase up to 10 g/l dry weight were obtained. The following culture conditions have been used: The medium contained 10 ml/l n-alkane and 6 g/l NH4Cl. The pH was adjusted to 6.5 and pO2 employed to 70% saturation. A 12 times higher amount of dry weight was observed compared with shake culture technique.

Acinetobacter↗
PubMed1981

EA-rosette test in cervical cell suspensions.

Use of the EA-rosette test to detect the presence or absence of cells with an Fc receptor is proposed as a method of screening for cancerous cells and cells of carcinoma in situ in suspensions of cervical cell populations, The EA-rosette test was performed on cervical cell suspensions from 2,437 patients. In 54% the rosette test was negative; i.e., no EA rosettes were observed in the cervical cell suspensions. The EA-rosette test was positive in 46% of the cases, within which most cells with severe dysplastic and carcinomatous features were found. The predictive value for the negative EA-rosette test was 99.8%.

Carcinoma in Situ↗
PubMed1979

[Experimental and pharmacokinetic studies with gentamicin PMMA beads (author's transl)].

Gentamicin PMMA beads (PMMA = polymethylmethacrylate) represent a new form of local antibiotic therapy for treating chronic bone and soft tissue infections. Gentamicin is released in high concentrations from PMMA. The therapeutic efficacy of the beads was demonstrated in a model of bone infection in dogs. Sufficiently high tissue concentrations of gentamicin were measurable for a period of 4 months. A very good tolerance of the beads was demonstrated in dogs as well as in cell cultures. High gentamicin concentrations exceeding the MBC values of relevant pathogens were measurable in patients at the site of infection. Serum and urine concentrations were low and therefore toxic side effects are excluded.

Animals↗
PubMed1979

[Effect of metyrapone on bile flow and bile acid excretion in Wistar rats].

The influence of metyrapone on bile flow and excretion of mono-(MBA), di-(DBA) and trihydroxy-(TBA)-bile acids was investigated in adult male Wistar rats after single and repeated pretreatment. MBA were not found in the rat bile. Metyrapone administration (200 mg/kg b.w. i.p.) 1 h before onset of a 3-hour bile collection period diminished bile flow and excretion of DBA and TBA. The relation TBA/DBA was changed towards DBA. Similar results were found after repeated administration 12 h after the last metyrapone injection (4 x 50 mg/kg b.w. i.p. per day for 4 consecutive days). But 60 h after the last metyrapone administration bile flow and the excretion of TBA were enhanced and the TBA/DBA ratio was changed towards TBA. The possible influence of metyrapone on bile acid hydroxylation is discussed and compared with metyrapone action on hydroxylation of foreign compounds.

Animals↗
PubMed1979

Comparison of cefazedone with cefazolin and cephalothin in treatment of experimental infections in mice.

The chemotherapeutic efficacy of (6R,7R)-7-(2-[3,5-dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen) was assayed in comparison to cefazolin and cephalothin in experimental bacterial murine infections with 6 gram-positive and 8 gram-negative strains of the genera Staphylococcus, Streptococcus, Pneumococcus, Escherichia, Klebsiella, Proteus, Pasteurella and Salmonella. In 5 out of 14 strains (Staphylococci, Streptococci, E. coli, Klebsiella) cefazedone was markedly superior to cefazolin, whereas both compounds were of similar activity against the remaining 9 isolates. As compared to cephalothin, cefazedone exhibited highly superior effectiveness in all organisms tested.

Animals↗
PubMed1978

Influence of drugs on bile acid excretion.

The hydroxylation of bile acids in rat liver microsomes in cyt P-450 dependent (Björkhem et al., 1975). To find out possible interactions between drugs and bile acid hydroxylation and/or active transport mechanisms we investigated the influence of the microsomal inhibitor metyrapon, the microsomal inducer phenobarbital and the intrahepatic cholestasis producing agents chlorpromazine, phenylbutazone and progesteron on bile flow and bile acid excretion. The excretion in monohydroxy (MBA), dihydroxy (DBA) and trihydroxy (TBA) bile acids were estimated in bile-fistula rats in three one hour periods. MBA, DBA and TBA were separated with thinlayer-chromatography and estimated fluorimetrically. Bile flow, bile acid excretion and relation TBA/DBA were influenced by acute and subchronic administration of the above mentioned drugs in different ways.

Animals↗
PubMed1978

The release of gentamicin from polymethylmethacrylate beads. An experimental and pharmacokinetic study.

Gentamicin incorporated in beads of polymethylmethacrylate has been shown capable of being released over a period of several months in concentrations sufficiently high to control most pathogens. The therapeutic efficacy of such beads has been demonstrated in a model of osteomyelitis of the femur in the dog. Good tolerance has been shown, both in the animal model and in tissue cultures. In forty-one patients with infection of either bone or soft tissue, mainly of the lower limb, the findings were similar. The concentrations in serum and urine were low, which excludes side-effects. The insertion of gentamicin-PMMA beads may prove to be a valuable new form of local antibiotic therapy.

Animals↗
PubMed1975

Staphylococcal micrococcins. III. Antibacterial and therapeutic properties.

Micrococcin M, micrococcin M1 and eight micrococcin M derivatives, and two peptide antibiotics produced by micrococci and staphylococci were investigated for their antibacterial activity and therapeutic value. These antibiotics appeared to act solely on Gram-positive bacteria, especially on staphylococci and streptococci, in quite low concentrations in vitro and exerting both bacteriostatic and bactericidal effects. Gram-negative bacteria were virtually not susceptible. Resistance to micrococcins developed very rapidly, due to existence of numerous primarily resistant cells in sensitive populations. Complete cross-resistance resulted from acquiring resistance to one of the micrococcin antibiotics. Therapeutic effects are poor, as micrococcins are not absorbed from the injection site or from the intestinal tract after peroral administration. Importance of micrococcins in nature may be high, especially when ecology of normal bacterial flora and carriage of staphylococci and streptococci are concerned.

Animals↗