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R L Cui

Publications and source records attributed to R L Cui.

5 recordsLinked to original sources

Pharmacokinetics of ceftizoxime in renal failure patients without dialysis.

AIM: To investigate the pharmacokinetics of ceftizoxime (Cef) in renal failure patients without any dialysis and supply the basis for a suitable clinical regimen. METHODS: Cef in plasma and urine was assayed by HPLC. RESULTS: After injecting Cef 16.7 mg kg-1, Cef concentration in blood was described as a 2-compartment open model. The main pharmacokinetic parameters were Vd 0.55 +/- 0.17 L kg-1; AUC 879 +/- 460 mg L-1 h; Cl 27 +/- 11 mL kg-1 h-1. T1/2 beta was 15 +/- 4 h. CONCLUSION: T1/2 beta in renal failure patients was about 10 times longer than that in normal volunteers. The clinical regimen should be adjusted in renal failure patients with infection, either prolonging the interval between Cef administration, or decreasing Cef dosage.

Ceftizoxime↗

Lysine substitution increases mu-selectivity of potent di- and tri-peptide enkephalin analogs.

A general trend toward increased mu-selectivity has been reported in two classes of minimal structure enkephalin analogs which contain the essential structural and functional information for potent enkephalin-like biological activity. A single Lys residue added to the amino terminal of several tripeptide amides, and to the potent dipeptide amide Tyr-DAla-phenylpropylamide, causes a further increase in mu-selectivity as determined in the stimulated guinea pig ileum (GPI) and mouse vas deferens (MVD) assays, and in receptor binding studies in homogenates of guinea pig brain. The effect of Lys substitution was a significant decrease in the delta-related MVD potencies.

Animals↗

Selectivity of minimum structure enkephalins.

The biological activity of 45 deletion tetrapeptide-, tripeptide- and dipeptide enkephalin analogs has been determined in the stimulated mouse vas deferens (MVD) and guinea pig ileum (GPI) assays. A comparison of the GPI and MVD activities of these 45 minimum structure analogs indicates a high degree of mu receptor specificity. The greatest selectivity is found in the dipeptide amide Tyr-DAla-benzylamide, while high selectivity was also found in the tetrapeptides Tyr-DAla-Trp-Leu-NH2 and Tyr-Aib-Phe-Leu-NH2, and in two tripeptides Tyr-DTrp-Phe-NH2 and Tyr-Pro-Phe-NH2. The dipeptide amide Tyr-DAla-(3-phenyl-1-propyl)-amide (DAPPA), which has been shown to possess high in vitro potency (on the stimulated GPI) and in vivo potency (analgesia in mice after icv administration), is shown to have 60 times the activity in the GPI assay relative to its activity on the stimulated MVD, further indicating the correlation between mu-receptor activity and analgesia.

Animals↗