Chronopharmacokinetics of paracetamol in normal subjects

The chronopharmacokinetics of paracetamol was studied in six male volunteers. Serum concentrations of paracetamol were determined after a single oral dose of 1 g, on three occasions, spaced at least 1 week apart. Plasma drug concentration vs time curves were obtained after dosage at 08.00 h (Day 1), 14.00 h (Day 2) and 20.00 h (Day 3), under standardized conditions. Pharmacokinetic parameters compared were t1/2,alpha, t1/2,Z, tmax, Cmax and AUCpo. No statistically significant differences were found.

The early detection of the effects of surgical shock on the viscera

One hundred and one patients, in shock after operations were reviewed to examine the visceral effects on their prognoses. The shock was caused in 65 cases by hypovolaemia and in 36 cases by sepsis. The effects were studied on the heart and cardiovascular system, liver, kidneys, gastrointestinal system, central nervous system, lungs and blood clotting system. Surgical shock affected more frequently the lung and liver (P less than 0.05 and P less than 0.01). The lungs were most frequently involved in hypovolaemia (25 patients) and sepsis (25 cases). Pathology of the lung was associated with the highest mortality rate (P less than 0.005), followed by kidney (P less than 0.01) then heart and central nervous system (P less than 0.025). Involvement of the gastrointestinal tract or clotting system alone was not associated with higher mortality rates, except in the presence of other visceral derangements. Lung affection also had a greater mortality followed by kidney and the central nervous system. Involvement of one or several organs in failure to survive septic shock is dealt with in the discussion. It is concluded that visceral involvement secondary to shock could be of importance for prognosis.

Metabolic studies of erythropoietin (Ep): I. A reliable micro assay method for Ep in rat plasma using fetal mouse liver cells (FMLC)

It is a well recognized problem that sample derived transferrin-bound iron (Tf-Fe) interferes with radio-iron incorporation into heme in the in vitro assay of erythropoietin (Ep) using fetal mouse liver cells (FMLC). This paper describes a mathematical procedure to correct for the unknown quantity of "cold" Tf-Fe in a plasma sample, being assayed for Ep in the FMLC. Excellent recovery of Ep activity was obtained with this method of correction, when testing solutions containing Step III sheep Ep with and without human Tf-Fe. The distorted dose response curves, obtained, when testing specimens of rat plasma, showed, after correction, linearity and parallelism to a Step II Ep dose response curve, permitting valid estimation of the potency ratio. Reproducibility of this method was found to be excellent. Accuracy was acceptable with plasma samples containing more than 50 mU Ep/ml. The FMLC and the exhypoxic polycythemic mouse assay were compared using several batches of rat plasma. Good agreement was found between the results in both assays. As only a small amount of sample is needed (0.2 ml plasma) this method enabled us to estimate EP activity in single rats serially without disturbing their plasma volume significantly.

Metabolic studies on erythropoietin (EP): II. The role of liver and kidney in the metabolism of Ep

Half plasma disappearance time (HDT) of endogenous erythropoietin (Ep) was measured in single rats, using an in vitro assay system for EP. In rats treated with the hepatotoxic agent d-Galactosamine-HCl (GalN), a small but significant elevation of HDT was found as compared with control rats (164 and 105 min, respectively). In bilaterally nephrectomized rats mean HDT was significantly elevated: 266 min. Combination of nephrectomy and GalN treatment did not result in a significant further elongation of HDT (mean = 301 min). In experiments using isolated liver perfusion, rat livers (with and without GalN treatment) were shown to be unable to change perfusate Ep titre during 4 h of perfusion. It is concluded that hepatic degradation of Ep in rats is only minimal. The kidney however is important in the catabolism of Ep.

Spontaneous reversible renal artery stenosis after renal allotransplantation;

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