A new procalcitonin cord-based algorithm in early-onset neonatal infection: for a change of paradigm.

Diagnostic of early-onset neonatal infection (EONI) remains an emergency. Recent studies underline the potential benefit of using Procalcitonin (PCT) in early diagnosis of bacterial infections in neonates. The aim of this study was to evaluate the diagnostic value of an umbilical blood cord PCT based algorithm in newborns suspected of EONI. The diagnostic value of the PCT based algorithm was compared to the French one currently in use by analyzing an 18-months database of newborns suspected of EONI in University Hospital of Nantes from March 2011 to September 2012. Among the 2,408 (40.8 %) newborns suspected of infection during this period, 2,366 were included in the study. The incidence of EONI was 3.4‰ (n = 20). There was no significant difference between the sensibilities of the PCT based algorithm and the current algorithm (90 %, respectively, 95%CI 76.9-100 versus 85.4-100; p = 0.90) and between their specificities (respectively 91.7 % (90.6-92.8) versus 87.4 % (86-88.7); p = 0.25). The antibiotic treatment rate would be significantly reduced with the PCT based algorithm [211 i.e. 8.9 % (7.8-10) versus 314 i.e. 13.3 % (11.9-14.7) in the current algorithm; p < 0.005] and less biological analysis would be performed [301 i.e. 12.7 % (11.4-14) versus 937 i.e. 39.6 % (37.6-41.6); p < 0.005]. Blood cord PCT seems to be a new and efficient marker to guide neonatologists taking care of newborns suspected of EONI. The PCT algorithm seems to be a safe alternative in diagnosis of EONI, allowing detection of EONI significantly as well as the current algorithm, without resulting in a substantially higher number of missed infections. These results have to be confirmed by a multicentric validation study.

[Diagnostic value of a new procalcitonin cord sample-guided algorithm to manage newborns suspected of early-onset infection]. / Prise en charge des nouveau-nés suspects d'infection néonatale précoce : valeur diagnostique d'un algorithme intégrant le dosage de la procalcitonine au cordon.

BACKGROUND: Diagnosis of early neonatal infection remains an emergency. Since clinical symptoms and biological markers are neither sensitive nor specific, many newborns suspected of infection undergo biological analysis and empirical antibiotic treatment while awaiting results. Recent studies underline the benefit of using procalcitonin (PCT) to differentiate inflammatory diseases and viral infections from bacterial infections. Joram shows that it is possible to go beyond the physiological peak of PCT in the first days of life by measuring PCT concentration in cord blood. The aim of this prospective study was to evaluate a new algorithm integrating the value of PCT in blood cord for taking care of newborns who have suspected infection. PATIENTS AND METHOD: The diagnostic value of the new algorithm was compared to the diagnostic value of the algorithm currently in use, by analyzing a 9-month prospective database of 1267 newborns suspected of infection. Infection status was established with the ANAES definition and clinical progression. RESULTS: Each infected newborn (n=8) would have been treated without delay with the current algorithm (based on ANAES guidelines) and this new algorithm. The new algorithm had the same diagnostic value as the current algorithm (P=0.5) with 87.5% sensitivity (95%CI [52-98]) versus 100% (95%CI [87-100]) and 87.4% specificity (95%CI [85-90]) versus 83.8% (95%CI [81-86]). Fewer biological analyses 13.1% (95%CI [11-16]) versus 42.2% (95%CI [39-45]) were performed with the PCT cord-guided algorithm than with the current algorithm (P<0.05), leading to a 64.2% cost reduction. Antibiotics were significantly less used with the new algorithm: 13.1% (95%CI [11-16]) versus 16.7% (95%CI [14-19]). CONCLUSION: PCT in cord blood could become a new and efficient marker to help neonatologists take care of newborns suspected of infection. These results must be confirmed by a larger multicenter prospective study.

Umbilical cord blood procalcitonin as a risk factor for mortality in very premature infants.

Fetal inflammatory response syndrome is implicated as a cause of fetal or neonatal injury. We analyzed the relationship between the procalcitonin umbilical cord blood level and neonatal outcome. A total of 237 preterms born in a level III perinatal medicine unit of a French university hospital were enrolled in a prospective observational study. Measurement of the procalcitonin umbilical cord blood level was performed at birth. After hospitalization, surviving infants were enrolled in the regional follow-up program. Outcome data were recorded on standardized questionnaires. The main outcome measures were neonatal mortality and impaired functional outcome at 2 years of corrected age. The terciles of procalcitonin levels were calculated. Preterm infants of the third tercile were defined as infants with elevated procalcitonin. Among the 237 infants, 13 (5.5%) died during the neonatal period, 20 (8.4%) were lost to follow-up, and 31 (13.1%) were classified as having an impaired functional outcome. After adjustment, elevated cord blood procalcitonin (>0.33 ng/ml) was significantly associated with an increase in mortality (adjusted odds ratio [aOR] = 8.3 [1.4-48]; p = 0.018), but not with the 2-year impaired functional outcome (aOR = 1.0 [0.4-2.5]; p = 0.93). Elevated umbilical blood cord procalcitonin concentration is an independent risk factor of mortality in preterm infants at less than 33 weeks' gestation.

Umbilical cord blood procalcitonin level in early neonatal infections: a 4-year university hospital cohort study.

This article describes a study of procalcitonin (PCT) measured in cord blood as a discriminating marker of early-onset neonatal infection. This was a monocenter retrospective study with prospective collection of data including all babies born during the study period. Those presenting infection risk factors had PCT measurement. Three groups were defined: certainly infected, probably infected, and non-infected. A total of 12,485 newborns were included, 2151 had PCT measurement, and 26 were infected. Receiver operating curves of PCT determined 0.6 ng/ml as the best cut-off, with an area under the curve of 0.96 (CI 95% 0.95-0.98). Sensitivity, specificity, positive and negative predictive value and positive and negative likelihood ratios were 0.92 (range, 0.75-0.98), 0.97 (0.96-0.98), 0.28 (0.20-0.36), 0.99 (0.99-0.99), 32 (24-41) and 0.08 (0.02-0.3), respectively. Post-test probabilities were 28% (23-33) if the test was positive, and less than 0.001% (0-1.10(-5)) if the test was negative. Gestational age between 28 and 32 weeks (OR 4.4; range, 1.2-16.2) and pH at birth < 7.10 (OR 2.9; 1.1-7.4) were other independent factors of increasing PCT (p < 0.05). PCT measured in umbilical cord blood is reliable to detect early infected and non-infected newborns.

Synthetic peptide issued from Hap1/LipL32 for new early serodiagnosis of human leptospirosis.

Leptospirosis is a worldwide zoonosis. Today, serological diagnosis is generally assessed by MAT. We performed ELISA with a synthetic peptide derived from Hap1/lipL32 which is a protein expressed only by pathogenic Leptospira. Repeatability and thresholds were defined with 85 controls sera and 119 hospitalized leptospirosis. The PP-ELISA repeatability and IgM/IgG cut-off values were based on control sera. For these cut-off values, we observed the IgM-PP-ELISA specificity of 89%, whereas it was 100% for the IgG. Then, we compared PP-ELISA and standard MAT results for leptospirosis patients. The concordance rate for IgM-PP-ELISA and MAT was low (43%), whereas it was 85% for IgG-PP-ELISA and MAT. During the first 5 days after hospitalization, PP-ELISA gave positive results in 13 out of 16 patients (81%) whereas 8 out of 14 patients (57%) were positive to MAT. ELISA using Hap1/lipL 32-derived synthetic peptide PP is an earlier serological diagnosis of human leptospirosis than MAT.

[Automated kinetic assay of plasmatic L-asparaginase activity undergoing therapy for acute lymphoblastic leukemia]. / Dosage automatique en cinétique de l'activité L-asparaginase plasmatique en suivi thérapeutique des leucémies aiguës lymphoblastiques.

The L-asparaginase is a critical drug for the treatment of acute lymphoblastic leukaemia, that achieves blood L-asparagin depletion. However, such a therapy is associated with a high rate of negative side effects, particularly antibody synthesis against L-asparaginase. This therefore decreases therapy efficiency requiring the monitoring of L-asparaginase activity since L-asparagin determination is not easy. We compared here the results obtained with an automated kinetic enzymatic method to those obtained with the most commonly used Nessler reagent method. The correlation coefficient, r = 0,992, obtained was very good, and the allometric regression line was y = 1,038x - 0,37 microkat/L. We also showed that the specificity and the precision were better with the enzymatic method than the Nessler one. Moreover, the enzymatic method was easier and required less time to perform. Finally, the method appears able to perform real time monitoring of the therapy.

Simple and sensitive determination of urea in serum and urine.

In this method for serum and urinary urea determination, the same reagent is used without predilution of urine samples. The method is based on the pH increase resulting from the ammonia released by urease hydrolysis of urea. o-Cresolphthalein complexone is used to monitor the pH change colorimetrically. Urea concentration and absorbance at 570 nm are linearly related for concentrations as great as 600 mmol/L for urine samples and 100 mmol/L for serum. There are no clinically significant interferences from physiological substances or drugs, and precision and accuracy are excellent (CV approximately 2%, except at very low concentrations in serum; analytical recovery was 99% in urine, 100% in serum). Results by this method (y) and by the Astra method (x) for urine correlated well (y = 0.991x - 2.87, Sy/x = 9.21, r = 0.994), as did the results by this method and by the total enzymatic method (x') for serum (y = 1.002x' + 0.192, Sy/x' = 0.598, r = 0.997). This method is applicable to automated as well as manual instruments, and one-reagent or two-reagent formats can be used.

Reaction of tyrosyl-modifying reagents with the ligand- and DNA-binding domains of the rabbit liver glucocorticoid receptor.

We have studied the effects of p-nitrobenzenesulfonyl fluoride, 4-fluorosulfonyl-1-hydroxy-2-naphtoic acid, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and tetranitromethane on the glucocorticoid receptor from rabbit liver. Our results show that all tyrosine modifying reagents inhibit the binding of [3H]dexamethasone to the receptor. Equilibrium binding experiments revealed that only 4-fluorosulfonyl-1-hydroxy-2-naphtoic acid is a competitive inhibitor while the other chemical probes decrease the concentration of binding sites. Transformation of glucocorticoid-receptor complexes was markedly reduced when heat treatment was performed in the presence of tyrosyl-directed reagents. Taken together, these results indicate for the first time that critical tyrosyl moieties may be involved in both hormone binding and transformation of the glucocorticoid receptor.

One-step 10(4)-fold purification of transformed glucocorticoid receptor. Method for purifying receptors associated with Mr ca. 90,000 heat-shock protein.

Chromatography of rabbit glucocorticoid-receptor complexes in the absence of sodium molybdate on a Mono Q anion-exchange column induces the transformation of the receptor and allows the resolution of the transformed and non-transformed molecular species. These abilities were used to design a new purification scheme for the glucocorticoid receptor from rabbit liver in its transformed state. Microgram amounts of receptor were obtained using this single-step procedure in less than 2 h. The purification yield was 50-60%. Immunoblot experiments showed that the glucocorticoid receptor was present as an Mr approximately 94,000 polypeptide in these preparations and represented 20-30% of the eluted proteins as determined by densitometric scanning analysis of silver-stained sodium dodecyl sulphate polyacrylamide gels. Finally, the purified receptor was able to interact quantitatively with bulk DNA.

An improved pyrogallol red-molybdate method for determining total urinary protein.

We adapted the pyrogallol red-molybdate method for total urinary protein to the Cobas Bio centrifugal analyzer. The method is simple, rapid, sensitive, and inexpensive. Addition of 25 mg of sodium dodecyl sulfate per liter to the reagent modifies protein reactivities so that the chromogenicity of human gamma globulins is the same as that of albumin. Results by this method and a comparison method that included gel filtration and a modified biuret reaction correlated well (r = 0.951).

[Microalbuminuria: evaluation of an immunoturbidimetric method and an immunonephelemetric method]. / Micro-albuminurie: évaluation d'une méthode immunoturbidimétrique et d'une méthode immunonéphélémétrique.

Two methods for measurement microalbuminuria are appraised to take the place of RIA. One is immunonephelemetry, using a "closed" immunochemistry analyzer of modest price. The other one is immunoturbidimetry on an "open" centrifugal analyzer, which is of a middle price. The results which are obtained by IN and IT are compared statistically to the RIA. These methods give satisfaction for practicability, precision and accuracy and can be used in any biological laboratory.

Occurrence of glucocorticoid binding sites in solubilized microsomes from rat liver.

Recent studies suggested the presence of specific glucocorticoid binding sites on rat liver microsomal membranes. We report here a new solubilization procedure which allows the physicochemical characterization of the microsomal glucocorticoid binding sites. Solubilization was achieved with 2 mM CHAPS in the presence of 5 mM benzamidine. Binding of [3H]cortisol showed a high affinity (Kd = 5.1 x 10(-9) M) and a limited capacity (0.72 pmol/mg of protein). The binding activity was abolished by elevated temperature and pronase. Competition experiments revealed that natural glucocorticoids and progesterone were highly potent competitors whereas dexamethasone and triamcinolone acetonide did not compete. Chromatography on DEAE Trisacryl and heparin Ultrogel confirmed that the solubilized protein is different from corticosteroid binding globulin and the cytosolic glucocorticoid receptor. Treatment of microsomal fractions with phosphatidyl inositol phospholipase C promoted the release of specific binding activity suggesting a putative glycosylphosphatidyl anchor for this protein. This finding may have interesting implications concerning the mechanism of glucocorticoid hormone action.

Interaction of rat liver glucocorticoid receptor with lectins: is the glucocorticoid receptor a glycoprotein?

Although glucocorticoid receptors have been extensively studied in a variety of tissues, the precise nature of the receptor protein still remains unknown. To further characterize this protein we assessed the effects of various lectins on [3H]dexamethasone binding to prepurified preparations of rat liver glucocorticoid receptor. Among the lectins tested only Ulex europeus and Lens culinaris induced a concentration-related decrease in [3H]dexamethasone binding. Following Ulex europeus or Lens culinaris exposure Scatchard analysis showed that these lectins led to a 3-fold reduction in receptor affinity without influencing the concentration of binding sites. These results provide new experimental evidence that rat liver glucocorticoid receptor would possess alpha-L-fucosyl and alpha-D-mannopyranoside residues in close proximity to the glucocorticoid receptor binding domain.

Nontransformed rabbit liver glucocorticoid receptor: purification, characterization and transformation.

The molybdate-stabilized nontransformed form of the glucocorticoid receptor from rabbit liver has been purified approximately 8,000-fold by a three-step procedure. The first step involved protamine sulfate precipitation which allowed a 5-6-fold purification with 85% yield. The second step, affinity chromatography using a N-(12-dodecyl-amino) 9 alpha-fluoro-16 alpha-methyl-11 beta, 17 alpha-dihydroxy-3-oxo-1,4-androstadiene-17 beta-carboxamide substituted Sepharose gel, purified the receptor 1,500-2,000-fold as calculated by specific radioactivity. The third step involved high performance liquid chromatography resulting in overall purification near 8,000-fold. The final glucocorticoid receptor appeared about 60% pure. The purified nontransformed glucocorticoid receptor had a sedimentation coefficient of 9 S in 0.16 M phosphate containing 5-20% sucrose gradients and the Stokes radius was 6.1-6.3 nm as determined by low pressure gel filtration and HPLC. Binding specificity of the purified receptor was identical to that previously reported in crude rabbit liver cytosol. Isoelectricfocusing and ion-exchange chromatography showed that the purification procedure affected the net charge of the receptor protein. This phenomenon could be related to interactions between the glucocorticoid receptor and cytosolic factors. SDS polyacrylamide gel electrophoresis showed a major Mr = 94,000 protein band which is in good agreement with previously reported values for glucocorticoid receptors. Transformation of the purified receptor was achieved after removal of molybdate by exposure at 25 degrees C to 0.4 M KCl. Characterization of the molecular forms was performed by means of incorporation into isolated nuclei, affinity towards polyanionic exchangers and high pressure size exclusion chromatography. Results show that about 40% of the receptor is in the transformed state.

Influence of molybdate, ionic strength and pH on ligand binding to the glucocorticoid receptor.

The addition of molybdate to rabbit liver cytosol increased significantly the affinity of the glucocorticoid receptor for [3H] dexamethasone without influencing the concentration of binding sites. This effect was concentration dependent. Analysis of the binding data by curve-fitting and Scatchard plot revealed the occurrence of a complex binding process in the presence of molybdate. The pH-dependence curve of the binding was shifted towards alkaline values by the oxyanion. Taken together, these data suggest that molybdate exerts its effects via an interaction with the receptor molecule.

Resolution of the molecular forms of rat liver glucocorticoid receptor by affinity chromatography on immobilized heparin.

Rat liver cytosolic glucocorticoid receptor labelled with [3H] dexamethasone and stabilized with molybdate was bound to heparin-ultrogel and eluted with NaCl or heparin as a single peak of radioactivity. After heat exposure of cytosol, two steroid receptor complexes could be separated by NaCl or heparin. Characterization of the two forms was performed by means of affinity towards isolated nuclei, sucrose gradient centrifugation and gel exclusion high performance liquid chromatography. The results presented here suggest that the two forms eluted from heparin-agarose correspond to the untransformed and transformed states of the glucocorticoid receptor complex. Taken together, these observations argue in favor of heparin-ultrogel as a suitable procedure to study the mechanism of glucocorticoid-receptor transformation.