Influence of photoisomers in bilirubin determinations on Kodak Ektachem and Hitachi analysers in neonatal specimens study of the contribution of structural and configurational isomers.

We compared data obtained with the Kodak Ektachem and Hitachi 717 Analysers and HPLC from 83 neonates under phototherapy. Total bilirubin values determined with the Kodak and Hitachi are in good agreement, but we observed a large discrepancy in the results for conjugated (Kodak) and direct (Hitachi) bilirubin. HPLC revealed that all the samples contained configurational isomers, while only 7.7% and 30.8% contained conjugated bilirubin and structural isomers, respectively. We developed a device for the specific and quantitative production of configurational or structural isomers, by irradiation with blue or green light. In vitro, total bilirubin values are coherent for the routine analysers in the presence of configurational or structural isomers. With configurational isomers, unconjugated bilirubin (Kodak) is lower than total bilirubin (Kodak), and conjugated bilirubin (Kodak) is always equal to zero, so the apparatus gives a false positive response for delta bilirubin. In contrast, the direct bilirubin (Hitachi) is constant. Furthermore, in the presence of structural isomers, unconjugated bilirubin (Kodak) is unexpectedly higher than total bilirubin (Kodak), conjugated bilirubin (Kodak) is proportional to the quantity of these isomers, and direct bilirubin (Hitachi) is constant. The contribution of photoisomers in bilirubin measurements is discussed.

[Validation trial of a neonatal prophylactic antibiotic protocol in the delivery room]. / Essai de validation d'un protocole d'antibioprophylaxie néonatale en salle de travail.

Maternofetal infection occurs in 1 to 10 of every 1,000 newborns. Prognosis is poor and an extremely rapid the clinical course is sometimes observed. The situation suggests that widespread use of antibiotics and more than 90% of the newborns receiving antibiotics are not infected. A prospective study based on simple, recognized criteria predictive of maternal-fetal infection was conducted in 3,392 deliveries to evaluate the effect of an antibiotic prophylaxy protocol. Specificity, sensitivity, positive and negative predictive value were evaluated for each of the eleven criteria retained with the goal of increasing sensitivity and decrease the use of unnecessary antibiotics. Among the 3,392 infants delivered from January 1989 to December 1990, 286 (8.4%) newborns entered the study and were given mezlocillin (150 mg/kg/12 h). This treatment was stopped at 48 hours of life if the infant was not infected. RESULTS. Infection was confirmed in 48 of 3,392 infants (1.4%). All were in the risk group: 48/286 (16.7%). The germs the most often found were group B Streptococcus (n = 16), Escherichia coli (n = 8) and Listeria monocytogenes (n = 3). Nine criteria were well correlated with maternal-fetal infection. The two most important criteria were maternal pyrexia above 39 degrees C and Apgar score below 7 to 5 min (poor neonatal adaptation), with a 99% and 90% and a positive predictive value of 80% and 37% respectively. Inversely, Two criteria were poorly correlated with maternal-fetal infection: labour duration above 12 hours and instrumental extraction (positive predictive value from 10% to 17%).(ABSTRACT TRUNCATED AT 250 WORDS)

Implications of hypervitaminosis A on the calcium-phosphate metabolism and on blood lipids in hemodialysis.

Serum levels of vitamin A (VA) were measured in 71 hemodialysis (HD) patients and in 30 normal controls. 65 of the 71 patients were taking multivitamin preparations (MP) containing VA. The HD patients had significantly greater values: 7.81 +/- 2.86 mumol/l (224 +/- 82 micrograms/dl) versus 3.97 +/- 0.97 mumol/l (114 +/- 28 micrograms/dl; p less than 0.0005); those taking MP with large doses of VA showed the highest levels. Patients were divided as having normal (group I, n = 21) or elevated (group II, n = 50) serum levels of VA. Patients of group II had higher levels of serum calcium (Ca) and lower of serum phosphate (P) and PTH than those of group I. Four months after the withdrawal of oral VA, the serum levels of VA and Ca fell significantly in group II, while the serum P increased. On the contrary, in group I serum levels of VA, Ca and P remained unchanged. Serum triglycerides (TG) were significantly higher in group II but did not change after the withdrawal of VA. No differences between both groups of patients were observed for age, time on HD, residual diuresis, residual renal function, serum levels of cholesterol (CL) or anemia. A retrospective study of 18 hepatic biopsies of HD patients disclosed hyperplasia of Ito cells (VA-storaging cells) in 7 of them. These 7 biopsies belonged to patients who had taken large amounts of oral VA. Our data indicate that prolonged VA intake in HD patients is followed by an increase of serum CA, a decrease of serum P and PTH and a hepatic accumulation of VA.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations induced by large doses of furosemide in chronic renal insufficiency.

Eleven patients with different degrees of renal failure with creatinine clearances between 7 and 32 ml/min have been studied. After a standard water overload and control periods of clearances, furosemide 1 g was given/i.v. There followed significant increase of renal plasma flow and glomerular filtration rate. In one case the increase was maintained during a follow up period of 3 hours. A significant increase was evident in phosphate, uric acid, sodium, potassium, and calcium clearances, as well as an increase in the sodium delivery to the distal nephron and a decrease in tubular reabsorption of phosphate. All this may be interpreted as the result of renal vasodilation induced by furosemide and its effect upon the proximal tubule and on Henle's loop.