Antonella Barbati

Immunochemical and Immunohistochemical Evaluation of Lung Permeability in Ventilated Newborn Rabbits

These experiments were designed to quantify the vascular-to-alveolar leakage albumin in the neonatal lung and to analyze the distribution of leaking airspaces in the lung parenchyma. Immediately after delivery, newborn rabbits with gestational age 27-29 days received an intravenous injection of human albumin as a marker and were ventilated for 15 min with standardized tidal volume (10 ml/kg). After the period of ventilation the lungs were either lavaged via the airways or fixed for histological studies. The median amount of albumin in lung lavage fluid, determined by immunodiffusion, was 4.8% of the injected dose after 27 days, 1.3% after 28 days, and 0.4% after 29 days of gestation; it was inversely correlated with the compliance of the respiratory system (r = -0.78; p less than .001). Immunohistochemical examination of lung section revealed that the leak was not diffuse; even in animals with gestational age 27 days it involved only a median of 48% of total alveoli. The median amount of alveoli containing the label fell to 6% after 28 days and to 0% after 29 days gestation, correlating inversely with the compliance of the respiratory system (r = -0.53; p less than 0.01). We suggest that our experimental model is useful for histological demonstration of serum proteins leaking into the airpaces under experimental conditions and for evaluating the effect of therapeutic regiments on neonatal lung permeability.

Inositol and glucocorticoid in the development of lung stability in male and female rabbit fetuses

ABSTRACT: Inasmuch as inositol affects the development of lung surfactant, and exogenous glucocorticoids accelerate fetal lung maturation, a possible interaction of the two substances on alveolar stability of preterm rabbit fetuses of 28 days gestation was investigated. On days 26 and 27 of gestation inositol or glucose were added to the diet of does treated with betamethasone (0.2 mg/kg intramuscularly on days 26 and 27). Inositol increased lung-thorax compliance of paralyzed fetuses at all insufflation pressures studied (from 16 to 22.5 and 30 cm H2O and back to 22.5, and 16 cm H2O). At a ventilation pressure of 30 cm H2O, lung-thorax compliance of fetuses treated with inositol plus betamethasone was more than doubled as compared with controls (1.2 ± 0.6 versus 0.5 ± 0.2 ml/kg ± cm H2O; p < 0.001). Inositol alone had no detectable effect on compliance, whereas betamethasone tended to increase compliance (p = 0.05). According to variance analysis, the effect of inositol was statistically significant only among the males. Inositol prevented the glucocorticoid-induced decrease in lung protein and, to a lesser extent, the decrease in DNA. Inositol did not further increase the lavageable surfactant pool of the glucocorticoid-treated, ventilated fetuses, although the area occupied by lamellar bodies within type II cells was increased after inositol plus betamethasone. According to the present study, inositol modifies the physiologic and biochemical response of the immature fetal lung to a pharmacologic dose of exogenous glucocorticoid.

Increased Urinary Cystatin-C Levels Correlate with Reduced Renal Volumes in Neonates with Intrauterine Growth Restriction

Background: Exposure to intrauterine growth retardation (IUGR) can have a negative impact on nephrogenesis resulting in limited fetal kidney development and supporting the hypothesis that IUGR represents a risk for renal function and long-term renal disease. Cystatin-C (Cys-C), a strong inhibitor of cysteine proteinases, is freely filtered by the kidney glomerulus and is reabsorbed by the tubules, where it is almost totally catabolized; what remains is subsequently eliminated in urine. In tubular diseases and in hyperfiltration conditions, it seems reasonable to postulate that Cys-C degradation would decrease, and consequently an increase in its urinary elimination would be observed. Objectives: The aim of this study was to investigate the urinary excretion of Cys-C simultaneously with the assessment of renal volumes in adequate for gestational age (AGA) and IUGR neonates in order to identify its clinical value in IUGR. Methods: Urinary Cys-C levels were measured using the enzyme immunoassay DetectX® Human Cystatin C kit in IUGR and AGA neonates. Whole renal and renal cortex volumes were assessed with ultrasounds (Vocal II; Software, GE). Results: Urinary Cys-C levels in IUGR were significantly higher than those found in AGA and were negatively correlated to reduced whole renal and renal cortex volumes. Conclusions: The increased levels of Cys-C in the urine of neonates with IUGR were significantly associated with reduced renal/renal cortex volumes, suggesting that Cys-C could be taken as a surrogate of nephron mass. It also could be used as an early biochemical marker to identify IUGR neonates at high risk of developing long-term renal disease and to select patients for monitoring during childhood.

No evidence of the hook effect in peritoneal fluid CA 125 measurement using immunoenzymatic second generation assays: comparison with immunoradiometric assays

OBJECTIVE To monitor the occurrence of the hook effect in measurements of peritoneal fluid CA 125 levels using two different immunoenzymatic second generation assays (ETI-II and EIA-II), and to compare these results with those obtained using the respective immunoradiometric versions of the assays (IRMA-II and ELSA-II). STUDY DESIGN CA 125 levels were determined in peritoneal fluid and serum samples obtained from 45 women with gynecological diseases. The assays were carried out using IRMA-II and ETI-II (Sorin Biomedica) and ELSA-II and EIA-II (CIS Bio International) assays. Occurrence of the hook effect and linearity of the assays were evaluated. Statistical analyses were performed by Wilcoxons test and linear regression analysis. RESULTS Undiluted peritoneal fluids, assayed for their CA 125 content, showed falsely underestimated values of the antigen when IRMA-II and ELSA-II assays were performed. The phenomenon disappeared only at high dilutions of the sample (> 50). Conversely, immunoenzymatic ETI-II and EIA-II assays performed on undiluted peritoneal fluids did not show underestimated CA 125 values. CA 125 values obtained by immunoenzymatic assay were lower than those obtained using their respective immunoradiometric versions at a dilution of 1:100 (P < 0.001). A good correlation was observed between ELSA-II and EIA-II (r = 0.929) CA 125 values. CONCLUSION The EIA-II immunoenzymatic assay appears to be more suitable for CA 125 measurement in peritoneal fluid in that it is not subject to the hook effect and its results correlated well with those obtained via its immunoradiometric version.

Regulation of CA 125 production by amnion and WISH cells in culture

Amnion and human amnion-derived WISH cells release CA 125 antigen into culture medium. CA 125 output was higher in WISH cells than in amnion cells. In this study we showed that release of the antigen is regulated, with both amnion and WISH cells responding in a similar manner to the tested agents. Release of CA 125 decreased in the presence of dexamethasone (10(-6) mol/L) or cycloheximide (0.1 micrograms/ml) and increased when colchicine (0.01 micrograms/ml) was added to the culture medium. Stimulatory and inhibitory effects were more apparent after 3 days in culture. The precise mechanisms by which some of these agents (colchicine and dexamethasone) affect CA 125 release remain unknown. We propose that amnion and WISH cells in culture represent a useful model to investigate some regulatory aspects of the production of CA 125 in normal tissues.

Lung maturation and prematurity

adrenal cortisol output. Co&sol, in turn, activates mechanisms leading to increased prostaglandin synthesis and decreased prostaglandin metabolism within the fetal membranes. The bio-availability of cortisol within the fetal membranes, in particular the chorion trophoblast cells, may be influenced by the expression of the enzyme 110 hydroxysteroid dehydrogenase type I. Intrauterine stresses such as hypoxemia may lead to precocious activation of the fetal HPA axis and increased cortisol production. In response to the hostile intrauterine environment this cortisol serves to facilitate organ maturation and may lead to the premature onset of labor. However, these events occur at the expense of fetal growth and may predisose the fetus to adult-onset diseases in later life.