Giovanna Mancuso

Interleukin 6 in neonates with early and late onset infection.

OBJECTIVE To assess the utility of determining interleukin 6 (IL-6) concentrations for diagnosing early (< or = 48 h of life) and late onset infection in a neonatal intensive care setting. METHODS We measured serum IL-6 values in five groups of neonates on both postnatal Days 1 and 2 (early sampling): Group 1, patients with clinical and microbiologic evidence of early onset infection; Group 2, patients with negative body fluid cultures but strong evidence of infection (clinical septicemia); Group 3, patients without clinical and microbiologic evidence of infection; Group 4, patients in whom infection could be neither confirmed nor excluded; and Group 5, healthy neonates with a normal postnatal course. We also measured IL-6 values in older neonates who during their hospital stay developed systemic infection (late sampling). Three controls matched for duration of hospital stay and birth date were chosen for each patient. RESULTS On postnatal Day 1 IL-6 values were elevated in all four patient groups compared with those in healthy neonates (P < 0.05 by analysis of variance (ANOVA)). There were no significant differences found among patient groups. On postnatal Day 2 IL-6 concentrations were persistently elevated in Groups 1 and 2 compared with values from those in Group 3, Group 4 and healthy controls (P < 0.01). At this time no significant differences in IL-6 values were found between uninfected symptomatic patients (Group 3), patients with uncertain findings (Group 4) and healthy controls. IL-6 concentrations were significantly higher in patients with late onset infection at presentation than in the patient controls (P < 0.0001) and returned to low values in those who recovered from infection. CONCLUSIONS There are differences in the serum concentrations of IL-6 that can be helpful in detecting early and late onset infection in preterm and term neonates. During the first 48 h of life serial IL-6 determinations are necessary so as not to overdiagnose infection in a neonatal intensive care setting.

Procalcitonin as a marker of nosocomial infections in the neonatal intensive care unit

ObjectiveTo determine accuracy of procalcitonin concentrations for diagnosing nosocomial infections in critically ill neonates.DesignCase-control study.SettingNeonatal intensive care unit of a teaching hospital.PatientsTwenty-three neonates with nosocomial infection. Four controls matched for duration of hospital stay and birth date were chosen for each case patient.Measurements and resultsPCT concentrations were measured by the LUMItest procalcitonin kit at onset of signs of infection and after recovery. Range of PCT concentrations (ng/ml) was 2.0 to 249.1 in case patients and 0.08 to 1.0 in controls (sensitivity and specificity, 100%). PCT values returned to normal (<1.0 ng/ml) by day 3 to 7 of appropriate antibiotic therapy.ConclusionsMeasurement of PCT concentrations may be useful for early diagnosis and monitoring of infectious complications in neonates during their stay in the neonatal intensive care unit.

Chemokine concentrations in nasal washings of infants with rhinovirus illnesses.

We determined RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin-8 (IL-8) concentrations, and total white blood cell (WBC) and differential counts in nasal wash samples from rhinovirus-infected infants presenting with wheezing or acute upper respiratory illness alone and compared them with those from healthy infants. RANTES concentrations were significantly greater in acute samples from wheezy patients than in those from patients with acute upper respiratory illness only, or in control samples. IL-8 concentrations and WBC and neutrophil counts were significantly greater in acute samples from wheezy infants and patients with upper respiratory illness alone than in control samples, but they did not differ significantly between the 2 patient groups.

A surface NAD-glycohydrolase of human platelets may influence their aggregation

Human platelets may hydrolyze externally added NAD+ yielding ADPR and nicotinamide. The extent of hydrolysis is significantly higher when the platelets are stimulated. The presence of external NAD+ strongly inhibits the aggregation induced by every agonist used. It seems that adenosine or ADPR itself generated by NAD+ hydrolysis may be responsible for the inhibition of aggregation. Evidence is given that some of the NAD+ hydrolysis product is taken up by stimulated platelets.

In vitro labeling of platelets with stable rubidium compounds.

It is a common practice in diagnostic hematology to mark blood cells with radioactive tracers, such as 51Cr, 55Fe, 75Fe, etc., to determine their lifespan and study their metabolism.A program has been started to verify the possibility of marking blood cells with stable indicators, assayed by radioisotope-induced X-ray fluorescence analysis. All elements may be considered as indicators aggregating to blood cells, and for in vivo measurements, which are not toxic in the quantities injected, calculated on the basis of the limit of detection of the technique.In this study platelets were marked with a very small quantity of stable compounds of rubidium, a potassium analog. Measurements were carried out in vitro on platelets of normal subjects and in vivo on platelets of rats and rabbits. Several survival curves were deduced and life-span values obtained in accord with previously reported values.

Analysis of iron in blood by radioisotope x-ray fluorescence

This paper is intended to demonstrate how it is possible to carry out simple and economical analyses of iron in blood using the radioisotopic excited X-ray fluorescence technique. This method requires only 0.1 ml of blood deposited on a disk of filter paper. The iron content analysis requires about 103 8, and the relative error is of about 1—3%. Utilization measurements of intramuscular injected iron have carried out in a large number of anaemical children.

OXYGEN RADICALS PLAY A ROLE IN THE PATHOGENESIS OF ANAPHYLACTOID PURPURA(AP)

Ceruloplasmin(CPM)was measured by an immunologic method in sera of children with AP during the acute phase of the disease, and the values were compared to that estimated by measuring serum ferroxidase activity. Controls were healthy adults. In agreement with previous observations, more copper-containing protein was present in the serum of AP patients than in control serum(43.4±12 vs 31.7±7.3 n=12, p=0.016 by Students t test). In control sera the same amount of CPM, measured either by immunologic or enzymatic method, was detected. CPM values of AP, patients, assayed as ferroxidase activity, were, instead, significantly lower than it would be expected on the basis of CPM protein found(p<0.001 by Students paired t test). However values were well correlated with the amount of CPM immunologically determined(r=0.971, p<0.001)suggesting for the presence of an abnormal protein. Our results indicate a critical role for oxidizing species in the pathogenesis of AP, since the discrepance between the protein amount and its enzyme activity is a marker of “in vivo” presence of oxygen radicals.