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Biomedical subjects

M Longini

Publications and source records attributed to M Longini.

7 recordsLinked to original sources

Early oxidative stress in amniotic fluid of pregnancies with Down syndrome.

OBJECTIVE: Some evidence suggests that oxidative stress, due to an imbalance between oxidants and antioxidants, occurs in babies with Down syndrome (DS). This study tests the hypothesis that oxidative stress occurs early in DS pregnancies. DESIGN AND METHODS: Isoprostanes (IPs), a new marker of free radical-catalyzed lipid peroxidation, were measured in amniotic fluid from pregnancies with normal, growth restricted and DS fetuses, diagnosed by karyotype analysis of amniotic cells cultured. RESULTS: A nine-fold increase in IP concentrations was found in amniotic fluid of pregnancies with DS fetuses. This increase (595.15; 542.96-631.64 pg/ml, median; 95% CI), was greater than in pregnancies with fetal growth-restricted fetuses (155; 130.57-172.23 pg/ml, median; 95% CI) and normal fetuses (67; 49.82-98.38 pg/ml, median; 95% CI; p<0.0001). CONCLUSIONS: The study reveals that oxidative stress occurs early in pregnancy and supports the idea of testing whether prenatal antioxidant therapy may prevent or delay the onset of oxidative stress diseases in the DS population.

Adult↗

Non protein bound iron concentrations in amniotic fluid.

OBJECTIVES: To investigate whether amniotic fluid concentrations of non protein bound iron (NPBI) vary with growth in healthy fetuses and also offer a reference curve in the second trimester of pregnancy. DESIGN AND METHODS: Amniotic fluid concentrations of NPBI were measured by HPLC in 118 women with physiological singleton pregnancies, who underwent amniocentesis for fetal karyotype between weeks 15 and 18 of gestation. RESULTS: NPBI increased progressively from weeks 14--15 to weeks 15--16, peaking at 17--18 weeks of gestation. NPBI values regressed positively with gestational age (GA). Multiple linear regression analysis between NPBI, as dependent variable, and various fetal parameters, as independent variables, showed a statistically significant regression coefficient with GA, bi-parietal diameter and transverse cerebellar diameter. CONCLUSIONS: The present data constitutes the first quantification of NPBI concentrations in amniotic fluid under physiological conditions. Correlations with GA and ultrasound fetal biometry suggest that NPBI may play a role in fetal growth.

Adult↗

Blood pressure in the small-for-gestational age newborn.

AIM: The aim of the paper is to verify the existence of an inverse correlation between birth weight and blood pressure (BP) in neonates, infants and adolescents. METHODS: BP was measured at 7 days, 3, 6, 9, 12 months and 7-18 years in 432 subjects born at term at the Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena; 228 of these subjects were small for gestational age (SGA) and 204 appropriate for gestational age (AGA). For small babies, BP was measured with a DYNAMAP oscillometer which provides digital visualisation of systolic, diastolic and mean arterial pressure and heart rate. In older children, a mercury sphygmomanometer was used. Statistical analysis was carried out with SPSS 8.01 software using the Kolmogorov-Smirnov test for normality of populations. RESULTS: Statistical analysis did not reveal any significant differences between SGA and AGA subjects in the various age classes of the first 12 months of life. Significant correlation was found between 7 and 18 years with differences in the various age classes for systolic pressure. Subjects with normal birthweight had lower systolic and diastolic BP. SGA males had higher risk of high systolic and diastolic pressure, whereas SGA females were only at higher risk for elevated diastolic pressure. CONCLUSIONS: SGA subjects should be monitored for BP and life-style between 7 and 18 years to risk of cardiovascular disease.

Adolescent↗

Perfluorocarbons attenuate oxidative lung damage.

The aim of this study was to investigate the effect of tidal liquid ventilation (TLV) compared to conventional mechanical ventilation (CMV) on oxidative lung damage in the setting of acute respiratory distress syndrome (ARDS). After repeated lung lavages, 10 minipigs were treated with CMV or TLV for 4 hr before the animals were sacrificed. Samples for blood gas analysis and bronchial aspirate samples were withdrawn before the induction of lung injury, and at 10 min, 2 hr, and 4 hr after the beginning of ventilatory support. To assess lung oxidative damage, total hydroperoxide (TH) and advanced oxidation protein product (AOPP) concentrations were measured in bronchial aspirate samples. After 2 and 4 hr of ventilatory support, partial oxygen tension (PaO(2)) and base excess (BE) were significantly higher in the TLV group than in the CMV group, while PaCO(2) was slightly higher, but with no statistical significance. In the CMV group, the AOPP level was significantly higher at 4 hr than at baseline. TH and AOPP bronchial aspirate concentrations were higher in the CMV group than in the TLV group at 2 and 4 hr of ventilation. We conclude that animals treated with TLV showed lower oxidative lung damage compared to animals treated with CMV.

Animals↗

Total hydroperoxide and advanced oxidation protein products in preterm hypoxic babies.

Previous studies have shown that plasma lipoproteins are a common target of free radical-induced oxidative stress in hypoxic newborn infants. In contrast to lipids, the reaction of proteins with various oxidants during hypoxia has not been extensively studied. We tested the hypothesis that tissue hypoxia results in increased production of protein oxidation in cord blood of preterm newborns. Heparinized blood samples of 39 hypoxic and 16 control preterm newborns were obtained from the umbilical vein, after cord clamping immediately after delivery. Plasma levels of total hydroperoxide (TH), advanced oxidation protein products (AOPP), hypoxanthine (Hx), xanthine (Xa), and uric acid (UA) were measured. Higher Hx, Xa, UA, TH, and AOPP levels were found in hypoxic newborn infants than in controls. Statistically significant correlations were observed between: TH and Hx (r = 0.54, p = 0.003, n = 28), AOPP and Hx (r = 0.64, p = 0.0001, n = 27), and TH and AOPP plasma levels (r = 0.50, p = 0.02, n = 21). In summary, TH, AOPP, Hx, Xa, and UA production is increased in fetal blood during hypoxia. The more severe the hypoxia, the higher the lipid and protein damage by free radicals.

Blood Proteins↗