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Biomedical subjects

U Ullmann

Publications and source records attributed to U Ullmann.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Resistance of Haemophilus influenzae to antibiotics in the Federal Republic of Germany (author's transl)].

In a multi-center study 523 strains of H. influenzae and H. parainfluenzae isolated from patients in eight towns of the Federal Republic of Germany were tested for their sensitivity to 15 different chemotherapeutic agents. 1.7% of the strains were resistant to ampicillin, 1,5% to chloramphenicol and 2.5% to tetracycline. All ampicillin-resistant strains produced beta-lactamase. For the first time, multiple resistant strains were isolated: two against ampicillin, chloramphenicol and tetracycline; one in addition also against co-trimoxazole. It is likely that there will be a spread of such resistant strains.

Ampicillin↗
PubMed1980

The significance of bacterial kinetic examinations for an adequate dosage of antibiotic.

The sources of error in the measurement of bacterial growth curves in closed systems are demonstrated by opacity. In investigations of bactericidal kinetics, it is necessary to observe the viable count by optical density because of the lesser susceptibility. Results obtained in this way cannot simply be applied to the chemotherapy of bacterial infections. Some of the findings may be important in view of our knowledge about the mechanism of antibacterial action, e. g. the latent period is important and indicates the speed of bactericidal action. In our experiments with eight cephalosporins and Klebsiella pneumoniae, the latent periods varied from 19.8 min for cefazolin to 102.8 min for cefuroxime. The inoculum dependence of antibacterial activity which was discovered in these investigations is also significant for determining an optimal dose because the bacteria should be reduced to a minimum by an initial high dose of antibiotic.

Anti-Bacterial Agents↗
PubMed1980

Distribution of Pseudomonas aeruginosa serotypes in bacteriologic specimens and their aminoglycoside resistance.

With regard to that of other facultatively pathogenic microorganisms, the rate of isolation of Pseudomonas aeruginosa was 12.5%. Most frequently the pathogen was isolated from wound swabs, tracheal secretion, throat swabs and urine. In 2.8% of the cases it was identified as the causative pathogen of sepsis. The serotype most commonly identified was the O antigen type 6, followed by types 11 and 1. The distribution of the serotypes observed in specimens and hospitals varied altogether. Epidemiologically striking was the incidence of serotype 1 in the urological division, of type 11 in the gynecological division, of type 6 in the pediatric division, and of type 4 in the dermatological division. Between 4 to 5% of the 618 strains examined exhibited resistance to gentamicin, tobramycin and sisomicin. Insensitivity to amikacin has not been observed. There were no statistically significant differences in incidence of resistance or the pattern of resistance as far as individual serotypes or isolates from the above mentioned divisions are concerned.

Amikacin↗
PubMed1980

In vitro investigations on the action fosfomycin alone and in combination with other antibiotics on Pseudomonas aeruginosa and Serratia marcescens.

86.4% of the Pseudomonas aeruginosa and 91% of the Serratia marcescens strains were sensitive to fosfomycin. In combination with mezlocillin, cefoxitin, gentamicin and nalidixic acid a synergistic action was detected against these bacterial strains. It was most marked in the combination fosfomycin/nalidixic acid against Serratia marcescens. An acceleration of the fosfomycin action on the bacterial cells and the speed of bacteriolysis was observed in weakly acid medium (pH 6.0), in the presence of 10% active human serum and with increasing glucose-6-phosphate concentrations in the test medium. There is no parallel resistance between gentamicin and fosfomycin against Pseudomonas aeruginosa.

Anti-Bacterial Agents↗
PubMed1980

High-pressure liquid chromatography and microbiological assay in the determination of serum levels using cefradine and cefaclor.

A method for the identification of cefradine and cefaclor by high-pressure liquid chromatography is described in detail. The antibacterial activity in the serum of ten subjects was determined by microbiological methods and by the HPLC method. No statistically significant difference exists between the values obtained by the two procedures. No decomposition of antibiotic occurs in the preparation of the serum sample for HPLC. The recovery rate was 94-105%. With the HPLC method 10 samples can be analysed within 70 min. The advantages and disadvantages of the method are discussed.

Adult↗
PubMed1979

[Quantitative determination of protein, albumin, and antibiotics in the nasal secretions of patients with acute sinusitis (author's transl)].

Forty outpatients with sinusitis were treated with equimolar doses of Ampicillin (556 mg) of Bacampicillin (800 mg) three times daily in a doubleblind fashion. To control the efficiency of the therapy the number of leukocytes, sedimentation rate, subjective and objective symptomes were evaluated before the first dose and on the 2nd and 10th day. On the 1st day nasal secretions were collected at the time the first dose was given and 1, 2, and 3 h later. In these samples the concentrations of the antibiotic, of protein and albumin were determined. The amount of nasal secretions collected as well as the protein and albumin content remains fairly constant during the experiment. The concentration of Bacampicillin in nasal secretions reaches its maximum of 0.92 microgram/ml 1 h after the application whereas with Ampicillin it is 0.59 microgram/ml after 2 h. These values correspond to the concentrations which were found in normal test persons. The clinical result of the therapy is slightly better with Bacampicillin only if patients with severe sinusitis were taken into account. In the patients with moderate or slight symptoms no difference was found. Two of the patients which were treated with Ampicillin had to stop the therapy because of severe diarrhoe. When using Bacampicillin no patients had diarrhoe. This study shows that Bacampicillin (as an inactive ester of Ampicillin) is resorbed quicker and gives higher concentrations in the nasal secretions. Thus, the therapeutic effect is better in severe cases as compared to Ampicillin. Moreover, the side effects are less.

Albumins↗
PubMed1979

[Quantitative determination of protein, albumin, and antibiotics in nasal secretions of healthy probands (author's transl)].

This study on the pharmacokinetics of antibiotics in nasal secretions was carried out with two orally applicable penicillin derivatives which show different resorption patterns. Each of the antibiotics (Ampicillin and Bacampicillin) was given in equimolar doses to 20 healthy young volunteers, with normal mucosa, in a double blind cross over fashion. Nasal secretions were collected 1, 2, 3, 4, 6, and 8 h after the application of a single dose to the overnight fasted persons. In 10 of them blood was taken at 0.5, 1, 1.5, 2, 3, and 4 h after the administration. For the sampling of the nasal secretions cotton wool was weighed together with an airtight vial containing 300 microliter of phosphate buffered saline (PBS). The dry cotton wool stayed in the nasal cavity for 20 min, was then put into the PBS and weighed again. The difference determines the amount of secretions collected. After 30 min the soaked cotton wool was pressed out into a vial with a sterile syringe. One hundred microliters of this solution was taken to determine the antibiotic concentration by a micromodification of the agar diffusion technique. In the remaining fluid total protein and albumin were quantitatively determined. The amount of nasal secretions which have been collected are, on average, independent of the time (Fig. 1). With rising secretion the protein content decreases (Fig. 5) as is the case with the albumin concentration. Regarding all persons, the protein content and albumin (Fig. 4) remain constant during the experiment from 8 a.m. to 4 p.m. The differences between the values shown in the figures are not significant. Comparing the mean concentration for the antibiotic at different times after the application, it is obvious that the agents show different curves (Fig. 6). With ampicillin the maximum of 0.13 microgram/ml is reached at 2 h after the administration whereas with becampicillin the maximum of 0.84 microgram/ml is reached after 1 h. The concentrations in the nasal secretions are clearly dependent of the serum values. In the serum the maximum of the mean values plotted against the time of 2.7 microgram/ml is to be found at 2 h, if ampicillin is given, whereas the maximum of 9.3 microgram/ml is reached at 1 h after bacampicillin administration. In both cases in serum and nasal secretions the mean concentration maximum is about three times higher after bacampicillin as compared with ampicillin. As a reference for the concentration of the antibiotic the total protein content of the sample is more suitable as compared with sample volume and albumin because of its easy and exact determination. The results show that the nasal secretions can be used as a model to evaluate the pharmacokinetics in the mucosa of the upper respiratory tract if an adequate number of test persons is used.

Adult↗
PubMed1979

Antibacterial active components in human urine after administration of penicillins.

Four-hourly urine from volunteers and patients who had received penicillins orally or intravenously was investigated by means of thin layer chromatography and bioautography. Antibacterially active metabolites were not detected with only two of 12 penicillins, namely amoxicillin and mezlocillin. In the case of the other penicillins the metabolites possessed variable antibacterial activity as could be demonstrated using different test microorganisms. After administration of carbenicillin esters three antibacterially active spots were detected, one of which corresponded to penicillin G; the other two were active against Pseudomonas aeruginosa. The bioautogram after treatment with azlocillin showed two components which were active against Bacillus subtilis, Staphylococcus aureus and Escherichia coli; only the rapid moving component was active against P. aeruginosa, however. The formation and chemical nature of these additional active components is still to a large extent not understood. It is quite possible, however, that they affect the bio-availability of an antibiotic.

Administration, Oral↗
PubMed1979

[Thin layer and high pressure liquid chromatography investigations with cefaclor in urine and serum (author's transl)].

After oral administration of 500 mg cefaclor, antibacterially active metabolites could not be detected in human urine using thin layer chromatography followed by bioautography. Degradation products of cefaclor could also not be detected in the serum of human volunteers (n = 10) using high pressure liquid chromatography with a reversed phase system. Cefaclor was eluated as a single and homogenous peak with a retention period of 2.9 min. High pressure liquid chromatography for the measurement of cefaclor serum levels and a technique for preparation of serum samples are described. After administration of 500 mg cefaclor to volunteers (n = 10), the average peak serum concentration of 9.8 mg/l, determined by high pressure liquid chromatography, was observed after one hour. Four hours later the serum level was 0.3 mg/l. Using microbiological methods no statistically significant difference was obtained in comparison with the chromatography results. Some of the sera stored at -75 degrees C for four weeks showed a substantial loss of activity of cefaclor.

Administration, Oral↗
PubMed1979

Bacteriological studies with cefsulodin (CGP 7174/E), the first antipseudomonal cephalosporin.

The new cephalosporin, cefsulodin, has considerable antibacterial activity against Pseudomonas aeruginosa. When 217 strains of Ps. aeruginosa were tested against both azlocillin and cefsulodin, 26.3% were found to have the same minimal inhibitory concentration (MIC); the MIC for azlocillin was lower than that for cefsulodin in 16.6% of strains, but higher in 57.1%. 22 gentamicin-resistant strains were all susceptible to cefsulodin. Biophotometer investigations demonstrate less bactericidal effects for cefsulodin and azlocillin than for carbenicillin and ticarcillin using higher inocula than used in the agar of tube dilution test. Cefsulodin and gentamicin are synergistic against Ps. aeruginosa. Using high pressure liquid chromatography and biological techniques, cefsulodin is found to be moderately stable in solution and in standard solid laboratory media.

Anti-Bacterial Agents↗
PubMed1978

[Spectrum of pathogens in odontogenous abscesses in the patients of the Tübingen Department of Maxillofacial Surgery].

Bacteriological examination and evaluation of 475 smears of pus taken from odontogenous abcesses showed that the spectrum of pathogens is extremely broad. Chemotherapy therefore should not be started before the pathogen has been identified and an antibiogram has been made due to possible resistance on the part of the microorganisms. Clindamycin may be used for "blind treatment" until the bacteriologic findings are available because it is effective against streptococcus and staphylococcus as well as gram-negative asporous anaerobes. The risk of the possible ineffectiveness of clindamycin against gramnegative anaerobes however must be taken. Clindamycin and gentamicin together may be helpful in life-threatening situations because the combination covers an extremely broad spectrum of possible pathogens.

Clindamycin↗
PubMed1978

[Contamination of surgical wounds in the maxillofacial region with microoranisms].

The analysis of 226 wound smears were statistically evaluated. Smears were taken immediately after beginning surgery (105) and during the course of the operation, usually toward the end (121). No bacteria were identified at the beginning of the operation in 11.6% of the smears; 8.6% of the smears taken toward the end of the operative procedure showed no bacteria. Microorganisms usually found in the buccal cavity were identified in approximately two thirds of the wounds. Every third or fourth wound contained facultative pathogenic bacteria at the beginning of the operation. The necessity of antimicrobial measures was discussed.

Face↗
PubMed1977

Correlation of minimum inhibitory concentration and beta-lactamase activity.

The beta-lactamase activity of 510 recently isolated Enterobacteriaceae was investigated with a quantitative photometric test. Beta-lactamase could be detected in 55 percent of the Enterobacteriaceae. At the same time minimal inhibition concentration (MIC) of beta-lactam antibiotics was determined. There was no correlation between MIC values and lactamase activity. For correct antibacterial therapy the clinician requires information on the lactamase activity of isolated bacteria in addition to the antibiogram. The qualitative test is useful for screening.

Amidohydrolases↗