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Biomedical subjects

C Kaiser

Publications and source records attributed to C Kaiser.

At least 163 records · Page 9Linked to original sources
PubMed1970

Mode of action of nitrofurazone.

When Escherichia coli strain B/r is exposed to 10 to 20 mug of nitrofurazone per ml, mutants with roughly threefold resistance are obtained. Treatment of these mutants with higher concentrations of nitrofurazone yields strains with six- to seven-fold resistance over strain B/r. Each of these steps toward nitrofurazone resistance is accompanied by loss of soluble nitrofurazone reductase activity. When sensitive bacteria are exposed to labeled nitrofurazone or labeled 2-nitrofuran, a considerable amount of radioactivity becomes bound to the cold trichloroacetic acid-insoluble fraction. Very little activity becomes bound in the mutants with six- to seven-fold resistance; mutants with intermediate resistance show intermediate levels of binding. Partially purified nitrofurazone reductase preparations catalyze the conversion of nitrofurazone to compounds which bind to protein and are not removed by prolonged dialysis against 8 m urea or by cold acid. Nitrofurazone reduced by xanthine oxidase or electrolytically reduced also yields compounds which react with protein to form stable derivatives.

Journal Article↗
PubMedDate not supplied

Results of echocardiographic examinations in a regional hospital of central Sudan.

Sixty-seven patients were examined with a small portable echocardiograph in Wad Medani Teaching Hospital in central Sudan. The cardiac alterations detected in the referred patients, namely valvular disease and pericardial effusion, suggested a high prevalence of inflammatory heart disease in this area. Other findings were dilatative cardiomyopathy, congenital heart disease, mitral valve prolapse and a cardiac mass. Echocardiographic examination of patients with advanced hepatosplenic schistosomiasis revealed no evidence of cardiac alterations or abnormal right heart function. For echocardiography a general purpose ultrasound scanner, as defined by the World Health Organization, was used, additionally equipped with M mode facilities. It was concluded that echocardiography is applicable even in remote tropical areas and that its value, considering costs, therapeutic consequences and clinical benefit in developing countries, can be substantial. It was particularly helpful with pericardial disease.

Adolescent↗
PubMedDate not supplied

The influence of guiding equipment and stents on the beta dose distribution in the brachytherapy of in-stent restenosis.

BACKGROUND: Intracoronary devices such as stents or guide wires may disturb the dose distribution of beta sources in cardiovascular brachytherapy. As clinical observations indicate that underdosage increases the risk of restenosis, accurate measurements are mandatory to investigate these effects. METHODS AND RESULTS: Dose perturbation effects of different interventional equipment were systematically determined. Dose distributions of 90Sr-beta line sources were measured by means of a special set-up employing plastic scintillator dosimeters in a water phantom. Shielding effects were found to be 2-5% for single stents and 5-10% for graft stents, stent-in-stent geometries, and guiding catheters. Guide wires close to the source reduced the dose by 25-30%. CONCLUSIONS: Beta dose perturbation effects of typical stent types are almost negligible and can be corrected by an increased source dwell time if necessary. Guide wires produce effects which are clinically much more important and should therefore be retracted from the irradiation area.

Brachytherapy↗