The minimal inhibitory concentration(MIC) of cephalosporin derivatives, (cephaloridine, cefazolin sodium, cephradine, cephapirin aodium, cephacetrile sodium, and cephalexin from various Korean drug companies) for Staphykcoccus aureus ATCC 25923 and Escherichia coli ATCC 25922 was measured by the tube dilution method, using Mueller-Hinton broth. The results obtained were as follows: 1) The MIC of each individual cephalosporin derivative, although produced by different manufacturers, was similiar or equal. 2) Against Staphyloeoccus aureus, cephaloridine and cephapirin had the lowest MIC while cephradine and, cephalexin the highest. Against E. coli, cephaloridine and cefazolin had the lowest MIC while cephradine and cephalexin the highest. 3) The MIC against Staphylococcus aureus was l5.6 to 250 times lower than that against E. coli in all cephalosporin derivatives. 4) The MIC against Staphylococcus aureus ranges from 0.0125 to l.0ug/ml and against E. coli from 1. 56 to 25ug/ml in all cephalasporin derivatives.
Cefazolin ; Cephacetrile ; Cephalexin ; Cephaloridine ; Cephapirin ; Cephradine ; Escherichia coli ; Staphylococcus aureus

The practice of adding antibiotics to anterior chamber-irrigating solutions as a prophylaxis for endophthalmitis has been used recently.To evaluate corneal endothelial toxicity of different concentrations of antibiotics in irrigating solutions, rabbit corneas were mounted in the in-vitro dual-cham-bered specular microscope and the endothelium was perfused with glu-tathione-bicarbonate Ringer solution (GBR)containing antibiotics such as ofloxacin, vancomycin or cephapirin.Mate corneas were perfused with GBR alone and used as control.Corneal thickness was measured every 15 minutes throughout the perfusion period and corneal swelling rates were calculated. Swelling rates of corneas perfused with 2 /ml or 5 /ml ofloxacin, 60 microgram/ml or1 0 /ml vancomycin, and 10 /ml or 20 /ml cephapirin was not significantly different from that of control (p>0.05).The corneas perfused with 20 /ml cephapirin deswelled probably due to high osmolarity of it.Perfusion with 10 /ml vancomycin plus 5 /ml ofloxacin did not show corneal swelling compared to control (p>0.05).This study demonstrates that the above concentra-tions of antibiotics in irrigating solutions do not affect endothelial function of the rabbit cornea.
Anti-Bacterial Agents* ; Cephapirin ; Cornea ; Endophthalmitis ; Endothelium ; Ofloxacin ; Osmolar Concentration ; Perfusion ; Vancomycin

Several of the newer broad-spectrum, potent antibiotics are currently being used for the treatment of meningitis, ventriculitis and shunt-tract infection. The risk of complications following intrathecal administration of some of this newer antibiotics varies considerably. Possible complications of immediate or delayed seizure, cortical electric depression, radiculopathy, transverse myelopathy, and arachnoiditis after intrathecal or intraventricular administration must be weighed against the potential value of this route. These risks may influence the therapeutic management of a specific clinical situation. The author studied the effect of the first generation of cephalosporins(cepalothin, cefazolin, cepharadine, cephapirin), the second generation of cephalosporins(cefamandole, cefmetazole), and the third generation of cephalosporins(cefotaxime, cetriaxone, cefotetan), on electrocortical activity of cerebral cortex. The results are as follows : 1) The topical application of cephalothin, cefazolin, cephapirin 8mg/ml shows electrocortical spike activity. In higher concentration, each cases show intense electrocortical spike activity. The topical application of cephradine 100mg/ml shows electrocortical spike activity and in higher concentration, electrocortical spike activity continued. 2) The topical application of cefamandole 64mg/ml shows electrocortical spike activity first and that of cefmetazole 100mg/ml shows electrocortical spike activity and in higher concentration of each cases, intense electrocortical spike activity continued. 3) The topical application of cefotaxime 16mg/ml shows electrocortical spike activity and that of ceftriaxon 200mg/ml and cefatetan 100mg/ml shows mild electrocortical spike activity. In higher concentration of each cases, electrocortical spike activity continued. In conclusion, the degrees of epileptogenic effect was most severe in the first generation of cephalosporins and the second generation of cephalosporins and the third generation of cephalosporins on the decreasing order.
Anti-Bacterial Agents ; Arachnoid ; Arachnoiditis ; Cefamandole ; Cefazolin ; Cefmetazole ; Cefotaxime ; Ceftriaxone ; Cephalosporins* ; Cephalothin ; Cephapirin ; Cephradine ; Cerebral Cortex* ; Depression ; Meningitis ; Radiculopathy ; Seizures ; Spinal Cord Diseases