Annals of clinical biochemistry
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Ann. Clin. Biochem. · Sep 1993
Role of plasma phosphate measurements in detecting rickets of prematurity and in monitoring treatment.
Twice weekly plasma and urine measurements were made in 24 very low birth weight infants. Intravenous feeding was given whilst infants required respiratory support. Subsequently they received breast milk or formula milk with a vitamin D supplement of 400 U/day. ⋯ Babies without radiological rickets had plasma phosphate levels > 1.2 mmol/L on breast milk and > 1.8 mmol/L in all but one on formula milk. Successful treatment of rickets was associated with a rise in plasma phosphate to the above levels. Untimed urine calcium and phosphate concentrations expressed as creatinine ratios were not helpful in detecting babies with rickets, but may be useful in monitoring therapy.
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Ann. Clin. Biochem. · Jan 1992
Hypophosphataemia in a hospital population and the incidence of concomitant hypokalaemia.
There have been few recent studies describing the incidence and causes of hypophosphataemia in a hospital population and the frequency of concomitant hypokalaemia. In this study a majority (53%) of patients with hypophosphataemia had been on a glucose infusion at the time of their low plasma phosphate. ⋯ Approximately, 11% of patients with hypophosphataemia (less than 0.8 mmol/L) had a plasma potassium equal to or less than 3.5 mmol/L, compared with 5.7% of hospital patients without hypophosphataemia. Furthermore, 20% of patients with severe hypophosphataemia (less than 0.3 mmol/L) had hypokalaemia as similarly defined.
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Ann. Clin. Biochem. · Mar 1990
Syringe injection pressure: a neglected factor in blood PO2 determination.
The mean arterial blood PO2 values of 20 patients' samples taken into Sarstedt 2 mL Monovette syringes were found to be initially 0.43 kPa higher and after 15 min storage 0.93 kPa higher than the mean values using Corning 3 mL Blood Gas Kit syringes. The Sarstedt syringe allowed entry of small air bubbles and the plunger was noted to be stiff. We speculated that high injection pressures might increase measured PO2. ⋯ Following injection at pressures between 2.8 and 26.6 kPa, the mean PO2 of equilibrated saline containing an air bubble was 0.80 kPa higher than the mean value obtained at injection pressures of less than 2.8 kPa. However, with no air bubble the mean PO2 of equilibrated saline was still 0.45 kPa higher when injected at pressures between 2.8 and 26.6 kPa than the mean value obtained with injection pressures of 2.8 kPa. We suggest that for optimal PO2 determinations syringes should not only allow minimal air contamination but also have plungers that reduce injection pressure to a minimum.
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In 1986 the Protein Commission of the Italian Society of Clinical Biochemistry (SIBIOC) carried out its second survey on the use of serum protein electrophoresis in Italian laboratories. Three serum samples plus a questionnaire were sent to the 253 laboratories which agreed to take part. ⋯ These features were chosen to assess (a) the type of report; (b) the resolution quality of the electrophoretic technique; and (c) the laboratory capacity to detect a small MC. The most significant features revealed by the survey were: (a) the poor capacity of assessment of the small MC in Serum 3 (only detected by 23.1% of laboratories); (b) the discouraging tendency to delegate electrophoretic diagnostic interpretation to ward physicians (44.4% of participating laboratories provided only densitometric values and graphs).
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Ann. Clin. Biochem. · Mar 1989
The influence of blood sample preparation on measured levels of morphine and its major metabolites.
The effect of six different methods of blood sample preparation on concentrations of morphine (M), morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) have been investigated using a specific high performance liquid chromatography assay. No difference between glass or plastic tubes was seen in concentrations of M, M3G, or M6G; and no difference between plasma and serum in M and M6G concentrations. ⋯ Heparin had no effect on M, M6G or M3G, whereas citrate in a glass tube produced consistently lower concentrations of M, M3G and M6G. Standardization of sample collection using plasma samples in plastic heparin tubes is recommended for future studies.