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Biomedical subjects

N Peretti

Publications and source records attributed to N Peretti.

7 recordsLinked to original sources

Asymmetrical regulation of scavenger receptor class B type I by apical and basolateral stimuli using Caco-2 cells.

Cholesterol uptake and the mechanisms that regulate cholesterol translocation from the intestinal lumen into enterocytes remain for the most part unclear. Since scavenger receptor class B type I (SR-BI) has been suggested to play a role in cholesterol absorption, we investigated cellular SR-BI modulation by various potential effectors administered in both apical and basolateral sides of Caco-2 cells. With differentiation, Caco-2 cells increased SR-BI protein expression. Western blot analysis showed the ability of cholesterol and oxysterols in both cell compartments to reduce SR-BI protein expression. Among the n-3, n-6, and n-9 fatty acid families, only eicosapentaenoic acid was able to lower SR-BI protein expression on both sides, whereas apical alpha-linolenic acid decreased SR-BI abundance and basolateral arachidonic acid (AA) raised it. Epidermal growth factor and growth hormone, either in the apical or basolateral medium, diminished SR-BI cellular content, while insulin displayed the same effect only on the basolateral side. In the presence of proinflammatory agents (LPS, TNF-alpha, IFN-gamma), Caco-2 cells exhibited differential behavior. SR-BI was downregulated by lipopolysaccharide on both sides. Finally, WY-14643 fibrate diminished SR-BI protein expression when it was added to the apical medium. Biotinylation studies in response to selected stimuli revealed that regulatory modifications in SR-BI protein expression occurred for the most part at the apical cell surface irrespective of the effector location. Our data indicate that various effectors supplied to the apical and basolateral compartments may impact on SR-BI at the apical membrane, thus suggesting potential regulation of intestinal cholesterol absorption and distribution in various intracellular pools.

CD36 Antigens↗

Mechanisms of lipid malabsorption in Cystic Fibrosis: the impact of essential fatty acids deficiency.

Transport mechanisms, whereby alimentary lipids are digested and packaged into small emulsion particles that enter intestinal cells to be translocated to the plasma in the form of chylomicrons, are impaired in cystic fibrosis. The purpose of this paper is to focus on defects that are related to intraluminal and intracellular events in this life-limiting genetic disorder. Specific evidence is presented to highlight the relationship between fat malabsorption and essential fatty acid deficiency commonly found in patients with cystic fibrosis that are often related to the genotype. Given the interdependency of pulmonary disease, pancreatic insufficiency and nutritional status, greater attention should be paid to the optimal correction of fat malabsorption and essential fatty acid deficiency in order to improve the quality of life and extend the life span of patients with cystic fibrosis.

Journal Article↗

New insights into the postnatal growth of infants born 'idiopathic' small for gestational age.

Infants born small for gestational age (SGA) are defined as those with a birth weight and/or birth length below two standard deviations for gestational age. Postnatal catch-up growth is absent in 8-12% of children born SGA and these children achieve adult heights far below their target height. The objectives of our retrospective study were to confirm the prevalence of catch-up growth and to refine the kinetics of the catch-up process. The 'Lyon series' of patients consisted of 179 children with 'idiopathic' SGA, of whom 8% did not achieve catch-up growth (i.e. their height remained below -2 SD throughout the study). The number of days that the mother was hospitalized before delivery was found to be significantly correlated with lack of catch-up growth. Maternal hypertension, term delivery and postnatal parenteral nutrition were also associated with lack of catch-up growth, but the relationship was not significant. In addition, an oscillatory growth velocity pattern was observed in boys and girls born SGA, with alternating periods of growth acceleration and deceleration. This suggests that catch-up growth is regulated in a sophisticated way by the hypothetical 'Somatostat', although further confirmation of this process is needed.

Female↗

Cytomegalovirus infection may cause ureteral necrosis.

Cytomegalovirus (CMV) infection has protean presentation among immunocompromised patients, but the urinary tract is rarely involved. We report a case of extensive ureteral necrosis in a renal transplant, 12-year-old patient with typical histological feature of CMV inclusions. The role of CMV was confirmed by immunohistochemical analysis and concomitant CMV DNA detection in peripheral blood leukocytes by polymerase chain reaction analysis. CMV infection can, therefore, be regarded as a possible cause of ureteral necrosis in renal transplant recipients.

Child↗

[Urinalysis using dipsticks].

Beneath its apparent simplicity, the urinary dipstick is one of the most important advances in the current diagnosis procedure in pediatric nephro-urology. This test represents the best way to approach the most frequent conditions, i.e., urinary tract infection, hematuria and proteinuria. It therefore offers reliable information at a very low financial cost.

Child↗

Aetiology, morphology and body composition of infants born small for gestational age.

Infants born small for gestational age (SGA) are a heterogeneous group. Both the timing and duration of the intrauterine insult determine the physical condition and body composition of the infant at birth. Infants with symmetrical intrauterine growth retardation (IUGR) have a similar body composition at birth to weight-matched infants born appropriate for gestational age. However, these infants are more likely to remain shorter and lighter than normal infants. In contrast, infants with asymmetrical IUGR have reduced fat deposition but are more likely to exhibit catch-up growth during the first few months of life. The low mortality and morbidity rates in infants born SGA observed in recent studies are linked to their appropriate perinatal management, including adequate early nutritional support.

Body Composition↗