ABSTRACT
OBJECTIVE: To evaluate the bacteriostatic effect of ε-polylysine( ε-PL) on four common putrefactive bacteria including Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli and its effect on urine lead level. METHODS: Broth dilution method was used for the determination of the minimum inhibitory concentration( MIC) ofε-PL on the four kinds of putrefactive bacteria; the inhibitory effects of ε-PL with final mass concentration of 40. 000 mg / L on the urine sample were observed; graphite furnace atomic absorption spectrometry was used for determining the lead level in the 40. 000 mg / L( mass concentration) ε-PL solution and the urine lead level in normal healthy groups; the bacteriostatic effects of ε-PL and nitric acid were compared. RESULTS: The MIC of ε-PL on Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli was 40. 000 mg / L. There was no bacterial growth in the urine sample with40. 000 mg / L( mass concentration) ε-PL when urine was kept at room temperature for 24 hours to 15 days. The lead level was < 2. 0 μg / L in the 40. 000 mg / L( mass concentration) ε-PL solution. When the ε-PL with final mass concentration of 40. 000 mg / L and the nitric acid with a volume fraction of 1. 0% were respectively used as the antiseptics,the descending rates of the lead levels in the urine samples were similar,and after the urine sample was preserved for 15 days,the descending rates of the urine lead were both smaller than 10. 0% after be stored for 15 days. CONCLUSION: ε-PL can substitute nitric acid as a new natural preservative for preservation of samples for urine lead determination.
ABSTRACT
Objective To study the influence of intraoperative use of saline and balanced salt solution on postoperative nerve function recovery in patients with brain trauma.Methods Totally 120 patients were randomly divided into the saline group and the balanced salt solu-tion group,and the postoperative nerve function recovery of the two groups were observed.Results The level of pH and HCO3 -24 hours af-ter operation in the saline group were lower than those in the balanced salt solution group (P <0.05),while the level of Cl - in the saline group was higer than that in the balanced salt solution group (P <0.05).The intracranial pressure and preoperative Glasgow coma score (GCS)of the two groups had no statistical significance (P =0.94).And the Glasgow coma score at 336 hours and 672 hours after opreation of the two groups were of statistical significance (P =0.00,P =0.03).The mortality of the saline group and the balanced solution group 28days after surgery were 15% and 10% respectively,and there was no significant difference between the two groups (P =0.58).Conclusion Saline resuscitation during surgery would lead to hyperchloremic acidosis as well as worse nerve function.However,the perfusion of balanced salt solution during the operation is more favorable to the recovery of neurological function.