A calculation model for serum ionized calcium based on an equilibrium equation for complexation.

Measurement of ionized calcium is more important than measurement of total calcium in serum samples. In the present study, equations were derived from complexation and acid dissociation equilibrium equations, and were used to determine the concentration of ionized calcium from the observed serum concentrations of total calcium, albumin, total protein, and inorganic phosphate. The ionized calcium concentration was calculated in 67 serum samples from healthy subjects and 34 outpatients previously identified as having abnormal serum calcium levels.

Transient elevation of serum cystatin C concentrations during perioperative cisplatin-based chemotherapy in esophageal cancer patients.

Purpose: In the present study, the time-concentration profile of platinum (Pt) in plasma was compared to that of serum cystatin C (Cys C) in Japanese esophageal cancer patients receiving perioperative cisplatin-based chemotherapy.

Methods: Five male and one female patients receiving 2 successive cycles of cisplatin-based chemotherapy combined with 5-fluorouracil, the treatment for esophageal squamous cell carcinoma, participated in this study. The pharmacokinetic parameters in each patient were calculated from the individual plasma Pt concentration-time curve after intravenous infusion of cisplatin using the one-compartment model.