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Biomedical subjects

M A Ramadan

Publications and source records attributed to M A Ramadan.

41 records · Page 3Linked to original sources
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Pleural lavage: a novel diagnostic approach for diagnosing exudative pleural effusion.

Patients with pleural effusions frequently present a diagnostic and therapeutic challenge. The diagnosis is based on the interpretation of the results of thoracentesis or pleural biopsy. When a malignant tumor metastasizes to the pleura, tumor cells can be seeded over the mesothelial surface or in the subserous layer. In the former situation, tumor cells are abundant in pleural fluid, but in the latter, few malignant cells are exfoliated into the pleural cavity, and microscopic deposits may not be visualized at thoracoscopy. Pleural lavage cytologic study at the time of thoracoscopy has not been studied. The purpose of this study was to assess the value of thoracoscopic pleural lavage as an adjuvant in the diagnostic workup of patients with exudative pleural effusions. Fifty patients with exudative pleural effusions were investigated by pleural fluid cytologic findings, Abram's pleural biopsy, thoracoscopy, and pleural lavage cytologic findings. After aspiration of all pleural fluid, 300 mL saline was instilled into the pleural cavity and then recovered for cytologic analysis. The final diagnoses were 32 malignant (64%), 15 tuberculous (30%), and 3 idiopathic (6%) effusions. In the malignant group, thoracoscopic biopsy had the highest yield (94%) followed by lavage cytologic analysis (84%), fluid cytologic analysis (62%), and biopsy with Abram's needle (50%). The sensitivity of combined thoracoscopy and lavage cytologic analysis was 96%. In the patients with tuberculous pleuritis, the yield from the pathologic examination of the biopsy specimen was 93% with thoracoscopy and 60% with the Abrams needle. The diagnostic yield with cytologic analysis on pleural lavage fluid is significantly higher than that on pleural fluid. This is probably because the cells in the lavage fluid are fresher and better preserved than those in the regular pleural fluid, which may have undergone degenerative changes, yielding false-negative results. Pleural lavage cytologic analysis should be performed in patients with suspected malignant pleural effusion who are subjected to diagnostic thoracoscopy, because it may provide additional information to thoracoscopic biopsy.

Adult↗
PubMedDate not supplied

Effect of beta-lactamase expression on susceptibility of local isolates of Enterobacter cloacae, Serratia marcescens and Pseudomonas aeruginosa to beta-lactam antibiotics.

During surveillance studies, a total of 66 strains of gram-negative bacilli (28 Enterobacter cloacae, 20 Serratia marcescens and 18 Pseudomonas aeruginosa) with a reduced susceptibility to third-generation cephalosporins, aztreonam and amikacin were isolated from documented infections. All isolates were highly susceptible to imipenem and sparfloxacin. beta-Lactamase activity was demonstrated in all isolates of E. cloacae and S. marcescens, and in 77% of P. aeruginosa isolates. Inducible beta-lactamase activity was detected in 80, 65 and 40% of E. cloacae, S. marcescens and P. aeruginosa isolates, respectively, when cefoxitin was used as an inducer. More inducible beta-lactamase producers were observed when imipenem was used as an inducer. Isolates of E. cloacae, and to a lesser extent S. marcescens, expressed a wide spectrum of beta-lactamase activities. There was a good correlation between baseline beta-lactamase activity and the respective MIC of ceftazidime, cefotaxime and ceftriaxone, and to a lesser extent aztreonam in E. cloacae and S. marcescens isolates. Only one isolate of E. cloacae demonstrated an extended beta-lactamase activity. The data suggest that the resistance of E. cloacae and S. marcescens isolates to beta-lactam antibiotics is largely dependent upon hyperproduction of beta-lactamase.

Anti-Bacterial Agents↗
PubMedDate not supplied

Inhibition of motility and adherence of Proteus mirabilis to uroepithelial cells by subinhibitory concentrations of amikacin.

The effect of subinhibitory concentrations of amikacin on Proteus mirabilis motility and adherence to human uroepithelial and to HeLa cells was compared with that of gentamicin. In addition, the effect of both antibiotics on cell surface hydrophobicity was also examined. Exposure of bacterial cells in the logarithmic phase to one fourth of amikacin or gentamicin at one fourth of their respective minimal inhibitory concentrations causes the inhibition of swarming and motility of Proteus strains. Amikacin significantly reduced adhesion of Proteus strains to human uroepithelial cells and gentamicin exerts the same effect to a lesser extent. Such inhibitory concentrations of amikacin or gentamicin had no significant effect on the attachment ability of these strains to HeLa cells compared to the nontreated cells. Treatment of the bacterial cells with amikacin or gentamicin changed significantly the cell surface hydrophobicity towards the hydrophilic state compared to nontreated cells, and it was found to be strain dependent. Since motility and attachment ability are considered as pathogenic traits, these data indicate the impact of amikacin on the virulence factors especially in urinary tract infections with Proteus strains.

Amikacin↗