Combined use of nuclear phosphoprotein c-Myc and cellular phosphoprotein p53 for hepatocellular carcinoma detection in high-risk chronic hepatitis C patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is a multistage process resulting from various genetic changes. We aimed to determine nuclear phosphoprotein c-Myc and cellular phosphoprotein p53 expression and to evaluate their importance in HCC diagnosis. METHODS: One hundred and twenty chronic hepatitis C (CHC) patients (60 non-HCC CHC patients and 60 HCC patients who had a single small (<5 cm) tumour) were recruited. The gene products of c-Myc and p53 were identified in liver tissues and serum samples using immunostaining, western blot and ELISA. RESULTS: Immunohistochemical detection of c-Myc and p53 with monospecific antibodies revealed intense and diffuse cytoplasmic staining patterns. Accumulated mutant proteins, released from tumour cells into the extracellular serum, were detected at 62 KDa, for c-Myc, and 53 KDa, for p53, using western blotting. In contrast to alpha feto-protein, there was a significant increase (p < 0.0001) in the positivity rate of c-Myc (86.7% vs. 6.7%) and p53 (78.3% vs. 8.3%) in the malignant vs. non-malignant patients. The parallel combination of c-Myc and p53 reach the absolute sensitivity (100%), for more accurate and reliable HCC detection (specificity was 87%). CONCLUSION: c-Myc and p53 are potential HCC diagnostic biomarkers, and convenient combinations of them could improve diagnostic accuracy of HCC.

The importance of incubation temperature for detecting beta-lactam-resistant Staphylococcus aureus strains.

Sixty-six isolates of methicillin-resistant Staphylococcus aureus strains originating from Austria, Egypt, the Federal Republic of Germany and Switzerland were tested for their sensitivity to 12 beta-lactam antibiotics at both 30 degrees and 37 degrees C using the agar disk diffusion test. The MICs for six of the beta-lactam antibiotics were determined by the microdilution technique. Resistance to methicillin was always accompanied by resistance to several beta-lactam antibiotics. Resistance to all semi-synthetic penicillins and cephalosporins, including cefotaxime, was higher at 30 degrees C than at 37 degrees C. Cephalothin and cefamandole proved to be the most effective cephalosporin antibiotics against methicillin-resistant S. aureus strains. Newer cephalosporins, i.e. cefotaxime, cefoxitin and cefuroxime, exhibited only a low rate of activity against these strains. The occurrence of phage-type "85" in S. aureus strains from Austria, Egypt and Germany indicates that certain lysotypes are widespread.

Nature of streptomycin resistance in enterobacteria from faeces of streptomycin-treated patients in Egypt.

Streptomycin-resistant enterobacteria were isolated from the faeces of 31 out of 35 patients under streptomycin therapy, in the University Hospital of Alexandria. The isolated bacteria were 26 Escherichia coli, 3 Klebsiella pneumoniae and 2 Enterobacter cloacae. Their resistance patterns have shown that 80% had multiple antibiotic resistance. The MIC of streptomycin for all strains was higher than 312 microgram/ml. Nearly 90% of these strains carried resistance plasmids. However, 3 strains possessed no plasmids and were assumed to be mutants. 60% of the plasmid-carrying strains have been able to transfer the resistance by conjugation. The rest have shown small plasmids, some of them were characterized by streptomycin and sulphonamide resistance and a molecular weight of 4.1 mega-daltons.

Kinetic studies of ampicillin action on Escherichia coli and their spheroplasts.

Kinetic studies of ampicillin action were made on exponentially growing Escherichia coli and on E. coli-spheroplasts using a range of inhibitory and subinhibitory concentrations of ampicillin. For each concentration, the value (ko--ka) representing the difference in generation rates of ampicillin-free culture (ko) and the generation rate of the culture with ampicillin (ka) was calculated and plotted against ampicillin concentration. A straight line relation was obtained with E. coli cells, its intersection with the abscissa, where (ko--ka) = o, give the concentration of ampicillin which exerts no inhibitory action on the cells (0.25 microgram/ml). When ka was plotted against ampicillin concentration, the relation was also linear. Its intersection with the abscissa gives the minimum lethal concentration of ampicillin on the bacterial cells (1.05 microgram/ml). With E. coli-spheroplasts such plots were non-linear which means that a different order of reaction was involved. This difference is probably due to a different mechanism of ampicillin action as revealed by the electroscanning microscopy.