Lucia Giordano

Proteomics: Bases for protein complexity understanding

In the post genomic era we became aware that the genomic sequence and protein functions cannot be correlated. One gene can encode multiple protein functions mainly because of mRNA splice variants, post translational modifications (PTM) and moonlighting functions. To study the whole population of proteins present in a cell to a specific time point and under defined conditions it is necessary to investigate the proteome. Comprehensive analysis of the proteome requires the use of emerging high technologies because of the complexity and wide dynamic range of protein concentrations. Proteomics provides the tools to study protein identification and quantitation, protein-protein interactions, protein modifications and localization. The most widespread strategy for studying global protein expression employs two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) allowing thousands of proteins to be resolved and their expression quantified. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has emerged as a high throughput technique for protein identification and characterization because of its high sensitivity, precision and accuracy. LC-MS/MS is well suited for accurate quantitation of protein expression levels, post-translational modifications and comparative and absolute quantitative analysis of peptides. Bioinformatic tools are required to elaborate the growing number of proteomic data. Here, we give an overview of the current status of the wide range of technologies that define and characterize the modern proteomics.

Platelet proteome in healthy volunteers who smoke

Smoking accelerates atherosclerosis and is a well-known risk factor for acute cardiovascular complications; however, the mechanisms of these effects have not been completely clarified. Recently developed proteomic approaches may offer new clues when combined with well-established functional tests. Platelet proteome of healthy smokers and non-smokers was resolved by two-dimensional difference gel electrophoresis, compared by Decyder software and identified by mass spectrometry analysis (nano-LC-MS/MS). In smokers, three proteins (Factor XIII-A subunit, platelet glycoprotein IIb and beta-actin) were significantly up-regulated, whereas WDR1 protein and chaperonine HSP60 were down-regulated. Furthermore, the highest scored network derived by Ingenuity Pathway Analysis using the modulated proteins as input showed the involvement of several proteins to be related to inflammation and apoptosis. Platelet function tests and the levels of markers of platelet and leukocyte activation were not different in smokers vs. non-smoker subjects. The platelet proteomic approach confirms that cigarette smoking triggers several inflammatory reactions and may help clarify some of the molecular mechanisms of smoke effect on cellular systems relevant for vascular integrity and human health.

Development and validation of serum bilirubin nomogram to predict the absence of risk for severe hyperbilirubinaemia before discharge: a prospective, multicenter study

BackgroundEarly discharge of healthy late preterm and full term newborn infants has become common practice because of the current social and economic necessities. Severe jaundice, and even kernicterus, has developed in some term infants discharged early. This study was designed to elaborate a percentile-based hour specific total serum bilirubin (TSB) nomogram and to assess its ability to predict the absence of risk for subsequent non physiologic severe hyperbilirubinaemia before discharge.MethodsA percentile-based hour-specific nomogram for TSB values was performed using TSB data of 1708 healthy full term neonates. The nomograms predictive ability was then prospectively assessed in five different first level neonatal units, using a single TSB value determined before discharge.ResultsThe 75 th percentile of hour specific TSB nomogram allows to predict newborn babies without significant hyperbilirubinemia only after the first 72 hours of life. In the first 48 hours of life the observation of false negative results did not permit a safe discharge from the hospital.ConclusionThe hour-specific TSB nomogram is able to predict all neonates without risk of non physiologic hyperbilirubinemia only after 48 to 72 hours of life. The combination of TSB determination and risk factors for hyperbilirubinemia could facilitate a safe discharge from the hospital and a targeted intervention and follow-up.

Orange juice intake during a fatty meal consumption reduces the postprandial low-grade inflammatory response in healthy subjects.

BACKGROUND AND AIMS Evidence associates polyphenol-rich foods to reduction of low-grade inflammation and mortality for cardiovascular disease, the mechanisms underlying such effects being still unclear. Consumption of a fatty meal by healthy volunteers induces rapid and reversible low-grade inflammation. The aim of the present study was to evaluate the effect of orange juice on cellular modifications induced by a fatty meal. METHODS AND RESULTS 18 apparently healthy subjects consumed a fatty meal, during which they drunk orange juice, either blond or red, or water, according to a randomized cross-over design. Two hours after the end of the fatty meal, both white blood cell (WBC) and platelet counts significantly increased (12.5 and 5%, respectively), while mean platelet volume decreased and a 25% release of myeloperoxidase (MPO) from polymorphonuclear leukocyte occurred. Both juices significantly prevented WBC increase and MPO degranulation, in respect to control. Triglycerides significantly increased (42%) after the fatty meal, but at a lower extent when red orange juice was consumed with the meal (20%), in respect to blond orange juice or control. This effect was statistically significant in the subgroup of 8 subjects with hypertriglyceridemia. Vascular stiffness (augmentation index), measured by Endo-PAT2000, significantly decreased after the meal only in conjunction with red orange juice. CONCLUSION In healthy subjects the concomitant intake of orange juice may prevent the low-grade inflammatory reaction induced by a fatty meal, at cellular and possibly at vascular function levels. The relative role of different polyphenols on the observed effects of orange juices remains to be established.

Methods of enteral feeding in preterm infants

Whenever possible, oral feeding is the preferred method in neonatal feeding. However, many premature infants are unable to suck and swallow effectively; in these cases alternative methods of nutrient delivery must be used. We briefly review the different feeding methods used in neonatal units, with particular attention to their theoretical advantages, disadvantages and to the current best evidence available.

Both red and blond orange juice intake decreases the procoagulant activity of whole blood in healthy volunteers

AIM Numerous epidemiological studies suggest that exposure to flavonoid-rich fruits has beneficial influence on risk factors for cardiovascular disease. We investigated whether intake of orange juice (OJ) could affect whole blood (WB) procoagulant activity. METHODS 17 healthy subjects (aged 31 ± 1.5 SEM 10 males) were randomized to receive, according to a cross-over design, either red or blond OJ, enriched or free of anthocyanins, respectively. After one week run-in period on a controlled diet, the subjects were randomly allocated to receive either type of OJ for 4 weeks, with a 4-week wash-out period. Venous blood was collected on citrate before and at the end of each treatment period. WB was incubated with or without an inflammatory stimulus (tumor necrosis factor-α or bacterial endotoxin LPS). Procoagulant activity was evaluated by a one-stage clotting assay. Tissue factor (TF) and TF pathway inhibitor (TFPI) were measured in plasma by ELISA. RESULTS Intake of either type of OJ caused a prolongation of unstimulated and stimulated WB clotting times, without any difference between the two treatments. Intake of OJ did not modify TF levels. On the contrary, an increase in circulating TFPI antigen was detected following either treatment. CONCLUSIONS Orange juice intake by healthy volunteers decreases procoagulant activity, possibly through mechanisms independent of its anthocyanin content.

Proactive Enteral Nutrition in Moderately Preterm Small for Gestational Age Infants: A Randomized Clinical Trial

OBJECTIVE To investigate the efficacy of a proactive feeding regimen (PFR) in reducing hospital length of stay in a population of moderately preterm small for gestational age (SGA) infants. STUDY DESIGN SGA infants (z-score <-1.28) of gestational age (GA) 32-36 weeks and birth weight (BW) >1499 g were allocated at random to receive either a PFR, starting with 100 mL/kg/day and gradually increasing to 200 mL/kg/day by day 4, or a standard feeding regimen, starting with 60 mL/kg/day and gradually increasing to 170 mL/kg/day by day 9. All infants received human milk. RESULTS A total of 72 infants were randomized to the 2 groups, 36 to the PFR group (mean GA, 35.1 ± 0.7 weeks; mean BW, 1761 ± 177 g) and 36 to the standard feeding regimen group (mean GA, 35.5 ± 1.2 weeks; mean BW, 1754 ± 212 g). Infants in the PFR group were discharged significantly earlier (mean, 9.8 ± 3.1 days vs 11.9 ± 4.7 days; P = .029). The need for intravenous fluids (2.8% vs 33.3%; P = .0013) and the incidence of hypoglycemia (0 vs 33.3%; P = .00016) were significantly lower in the PFR group. Feeding intolerance and fecal calprotectin levels did not differ between the 2 groups. CONCLUSION A PFR in moderately preterm SGA infants is well tolerated and significantly reduces both the length of stay and the risk of neonatal hypoglycemia.