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Biomedical subjects

A Wildfeuer

Publications and source records attributed to A Wildfeuer.

At least 109 records · Page 6Linked to original sources

Investigations on the specificity of the Limulus test for the detection of endotoxin.

Lysates obtained from amoebocytes of Limulus polyphemus, the horseshoe crab, showed gel formation after the addition of bacterial endotoxin. In contrast to living gram-negative bacteria, viable gram-positive microorganisms did not cause gelation of lysate. Nevertheless, peptidoglycan isolated from the cell walls of various gram-positive organisms did induce the reaction. However, the activity of peptidoglycan was 1,000 to 400,000 times less than that of Escherichia coli lipopolysaccharide. After exposure to lysozyme, peptidoglycan no longer gelled amoebocyte lysate, therefore apparently excluding endotoxin contamination. Gelation of amoebocyte lysate by endotoxin or peptidoglycan was inhibited by different concentrations of sodium polystyrolsulfonate. Whereas these studies confirm the specificity of the Limulus test for bacterial endotoxins, they also indicate that other substances of bacterial origin should be investigated for their ability to gel amoebocyte lysate.

Arachnida↗

Concentrations of ampicillin and sulbactam in serum and tissues of patients undergoing ENT surgery.

2 g ampicillin and 1 g sulbactam were given by infusion to 24 patients who were to be operated on in the ENT region. About 1 hour later during the operation samples of serum and of various tissues were taken and analysed for ampicillin and sulbactam. The mean serum concentrations of ampicillin and sulbactam were 59.2 mg/l and 31.6 mg/l, respectively. At the same time the concentrations of the two drugs were usually lower in the tissues than in serum. About 1 hour after the infusion the mean tissue concentration of ampicillin was 33.5 mg/kg and of sulbactam 19.5 mg/kg. The results show that ampicillin and sulbactam penetrate within an hour into the different tissues affected by the operation and maintain about the same ratio as in serum (2:1). The concentrations of ampicillin and sulbactam measured in the different compartments are capable of inhibiting the bacteria most frequently involved in ENT infections. These measurements unequivocally support the use of the ampicillin/sulbactam combination in the treatment and perioperative prophylaxis of bacterial infections of the ENT tract.

Adolescent↗

Pharmacokinetics of ampicillin, sulbactam and cefotiam in patients undergoing orthopedic surgery.

As perioperative prophylaxis for major orthopedic operations 81 patients were given the fixed combination of ampicillin (1 g)/sulbactam (0.5 g) or cefotiam (2 g) as short infusions. The three beta-lactams were rapidly distributed into the different tissues and their pharmacokinetic profiles were found to be very similar. It was noteworthy that ampicillin, sulbactam and cefotiam penetrated within minutes, not only into skin, fat and muscles, but also into bone. Thus 0.25 h after starting the infusion the following mean concentrations were measured in bone: 21.8 +/- 10.5 mg/kg ampicillin, 4.9 +/- 2.2 mg/kg sulbactam and 19.4 +/- 10.6 mg/kg cefotiam. For a period of at least 2 h the concentrations measured in serum and in the different tissues affected by the operation (skin, fat, muscle, bone) were above the MICs for pathogens which are involved in postoperative wound infections. On the basis of pharmacokinetic data, ampicillin/sulbactam and cefotiam seem about equally suitable for perioperative prophylaxis in major orthopedic operations.

Adult↗

Penetration of ampicillin and sulbactam into human epididymis and testis.

Urologic refertilization microsurgery such as vaso-vasostomy or vaso-epididymostomy benefits from perioperative antibiotic prophylaxis. The ability of ampicillin and sulbactam to penetrate sufficiently into mixed epididymis or testis tissue was investigated in nine patients (bodyweights ranged from 58 kg to 92 kg, mean 77.3 kg) undergoing orchiectomy for testicular cancer or advanced prostatic cancer. Each patient received a single infusion of 3 g ampicillin/sulbactam (ratio 2:1) preoperatively for antibiotic prophylaxis. The concentrations of both components were determined in serum and in epididymis/testis tissue samples taken 30 min to 65 min after infusion. Ampicillin was determined by bioassay and sulbactam was determined by gas chromatography/ mass spectrometry. Mean tissue concentrations of ampicillin were 38.5 +/- 15.9 mg/kg. Mean tissue concentrations of sulbactam at the same time were 19.8 +/- 5.2 mg/kg. Comparison of the tissue/serum ratios for both agents showed no significant difference. These values indicate that both compounds achieve high concentrations in the scrotal organs. The concentrations exceed the MIC (minimal inhibitory concentration) values of important bacterial pathogens such as Staphylococcus aureus involved in postoperative wound infections. The combination of ampicillin and sulbactam may be effective for perioperative prophylaxis in reconstructive scrotal urologic surgery.

Adult↗

Concentrations of ampicillin and sulbactam in serum and in various compartments of the respiratory tract of patients.

After infusion of 2 g ampicillin and 1 g sulbactam the concentrations of these two beta-lactams were determined in serum and various compartments of the respiratory tract of 22 patients. About 30 min after the end of the infusion in 15 patients the mean serum concentration of ampicillin was 97 +/- 9.5 mg/l and of sulbactam 37.6 +/- 3.8 mg/l; in the biopsy samples of bronchial mucosa the concentration of ampicillin was 38.6 +/- 7.2 mg/kg and of sulbactam 28.1 +/- 5.2 mg/kg; in bronchial fluid the concentration of ampicillin was 0.6 +/- 0.1 mg/l and of sulbactam 0.3 +/- 0.1 mg/l (n = 15). In a further seven patients serum and pleural empyema samples were analysed and compared. The mean values of Cmax attained 1 to 2 h after the end of the infusion in pleural empyema were 7.6 +/- 3.1 mg/l and 6.2 +/- 1.6 mg/l for ampicillin and sulbactam, respectively. The two beta-lactams were eliminated markedly more slowly from empyema than from serum. These results show that ampicillin and sulbactam rapidly penetrate into various compartments of the respiratory tract and reach therapeutically active concentrations. The ratio of their concentrations (2:1) is largely the same as that in serum. The pharmacokinetic data therefore support the use of ampicillin/sulbactam in the perioperative prophylaxis and the treatment of bacterial infections of the lower respiratory tract.

Adult↗

Penetration of ampicillin and sulbactam into human costal cartilage.

The question of whether ampicillin and sulbactam are able to penetrate sufficiently into costal cartilage tissue was investigated in 21 children undergoing surgery for funnel chest malformations. The concentrations of both compounds were determined in the core and mantle pieces of samples taken 45 min or 120 min after infusion of ampicillin/sulbactam (33.3/16.7 mg/kg bodyweight) preoperatively for antibiotic prophylaxis. Ampicillin was determined by bioassay and sulbactam was determined by gas-chromatography/mass spectrometry. Mean concentrations of ampicillin were 23.3 mg/kg and 10.4 mg/kg at 45 min and at 27.4 mg/kg and 7.8 mg/kg 120 min in the mantle and core piece, respectively. Mean concentrations of sulbactam were at the same time 21.3 mg/kg and 9.7 mg/kg and 17.5 mg/kg and 11.9 mg/kg, respectively. These values indicate that both compounds achieve high concentrations even in bradytrophic tissue such as cartilage. The concentrations exceed the MIC values of important bacterial pathogens involved in postoperative wound infections. Therefore ampicillin protected by sulbactam appears to be a well-suited agent for perioperative prophylaxis in thoracic surgery.

Adolescent↗