[Quality control of capillary blood measurements in clinical services: follow up by the biologist]. / Contrôle de qualité des analyseurs de glycémie capillaire dans les services hospitaliers: suivi par le biologiste.

In Bichat-Claude Bernard Hospital, the study of capillary glucose analyzers in the aim of uniformizing the selection of glucose meters, has shown the relevance of a standardized handling in order to obtain clinically interpretable results. It has been necessary to implement a quality follow up by the biologist. In the first stage, the biochemistry laboratory, with the clinical service supervisor and the supplier, has assured the training of the medical staff habilitated to use the meters and to carry out a quality control. In the second stage, the biologist implemented a monthly control on a total blood control sample, the stability of which has been checked after the necessary addition of glucose. Dosing of that sample, which is used as an external control, is carried out in parallel by the QID Precision glucose analyzer (Abbott) and by the portable Hemocue B Glucose (Vermed), which is selected as a comparison standard. This allows a monthly control of the accuracy of the meter. The condition of the equipment, as well as the weekly control follow up, validated by the nurse, is registered on a sheet prepared by the biologist. In partnership with Vermed, we have developed a processing software of the data stored in the Hemocue, allowing the automatic issue of a report summarizing the equipment condition and the data of weekly and monthly controls follow up. This report, signed by the biologist, is sent to every Service Manager and Supervising Nurse. On the basis of our one year experience, this practice has generated an efficient collaboration between the clinical services and the biochemistry laboratory, allowing to keep the quality of the capillary glucose measurements performed in inpatients.

Effects of 50 Hz magnetic fields on C-myc transcript levels in nonsynchronized and synchronized human cells.

The effects of 50 Hz electromagnetic fields (EMFs) on the expression of the c-myc oncogene, known to be involved in normal cell proliferation and possibly also in tumor processes, were investigated in nonsynchronized human lymphoid cells immortalized by Epstein-Barr virus. Viral injury to such cells makes them a good model for exploring the possible cancer-promoting effects of 50 Hz magnetic fields. Parallel experiments were conducted on human HL60 leukemic cells. Cells were exposed to sinusoidal 50 Hz EMFs at 10 microT or 1 mT for 20 min, 1 h, 24 h, or 72 h. Exposure was performed either immediately after refeeding or 1.5 h after refeeding. C-myc transcript values were assessed by Northern blot analysis and normalized to those of the noninducible gene GaPDH. No statistically significant difference between the c-myc transcript levels of control and exposed cells was found in lymphoid or leukemic cells under our experimental conditions, either after short exposures of 20 min and 1 h or after longer exposures of 24 and 72 h. Other experiments were carried out with pseudosynchronized cells in an attempt to establish whether cells were especially sensitive to 50 Hz magnetic field exposure in any particular phase of the cell cycle. Accordingly, cells were pseudosynchronized in G0/G1 by serum deprivation and exposed for 20 min to a 50 Hz magnetic field, at 10 microT for lymphoid cells and 1 mT for HL60 cells. No significant difference was observed between the c-myc transcript levels of control and exposed cells for either of the synchronized cell types. These results for synchronized cells correlated with those for nonsynchronized cells.

Effects of cyclosporine on tubular acidification function in patients with idiopathic uveitis.

Renal tubular acidification function was studied in 12 patients treated with cyclosporine (Cy) for idiopathic uveitis (IU) and in 5 patients with IU not treated with Cy. After intravenous bicarbonate loading fractional bicarbonate excretion was similar in both groups indicating normal proximal tubular acidification function. Plasma renin activity, plasma aldosterone and transtubular potassium gradient were similar in both groups. Distal hydrogen ion secretion evaluated by the ability to increase urine-blood (U-B) pCO2 in a highly alkaline urine was impaired in Cy-treated patients (31.8 +/- 3.2 mm Hg) as compared to controls (47.9 +/- 0.5 mm Hg) (p < 0.005). We conclude that Cy therapy is associated with a distal acidification defect with a low U-B pCO2 gradient during sodium bicarbonate loading. Because none of our Cy-treated patients spontaneously developed over metabolic acidosis one could classify them as having an incomplete form of distal tubular acidosis.

Serum neopterin and beta 2-microglobulin concentrations in monoclonal gammopathies.

Serum neopterin and beta 2-microglobulin concentrations were investigated in 46 patients with multiple myeloma and in 28 patients with asymptomatic monoclonal gammopathy followed for long periods (median 9.6 years) and showing an absence of evolution. Seventy-two per cent of the patients with multiple myeloma showed beta 2-microglobulin concentrations higher than 3 mg/l with a mean of 6.84 mg/l, whereas all the patients with asymptomatic monoclonal gammopathies had concentrations lower than 3 mg/l with a mean of 1.64 mg/l. Concerning serum neopterin concentrations, 91% of the patients with multiple myeloma had values with in pathological limits (greater than 8 nmol/l) with a mean of 34 nmol/l, whereas all but one of the patients with asymptomatic monoclonal gammopathy had normal values with a mean of 5.19 nmol/l. The differences thus observed in these two groups of patients are highly significant (p less than 0.001). Serum neopterin concentration, unrelated to renal insufficiency, seems to be useful in the differentiation of malignant or benign asymptomatic monoclonal gammopathies.