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243 result(s) for "Di Pierro D."
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Eicosapentaenoic acid (EPA) reduces crypt cell proliferation and increases apoptosis in normal colonic mucosa in subjects with a history of colorectal adenomas
Omega-3 fatty acids in fish oil exert a protective effect on the development of colorectal cancer in animal models. Patients with colorectal adenomas have been shown to have increased crypt cell proliferation and decreased apoptosis in macroscopically normal appearing colonic mucosa. We investigated whether dietary supplementation with eicosapentaenoic acid (EPA) could alter crypt cell proliferation and apoptosis in such patients. Thirty subjects were randomised to either 3 months of highly purified EPA in free fatty acid form (2 g/day) or to no treatment. Colonic biopsies were taken at the initial colonoscopy and repeated 3 months later, and analysed for cell proliferation and apoptosis (immunohistochemistry) and mucosal fatty acid content. Crypt cell proliferation was significantly reduced whilst apoptosis was significantly increased after EPA supplementation. Neither crypt cell proliferation nor apoptosis were altered in the control group. EPA in the mucosa increased significantly after EPA supplementation, whereas there was no significant change in controls. Dietary supplementation with EPA significantly increases levels of this fatty acid in colonic mucosa, associated with significantly reduced proliferation and increased mucosal apoptosis. Further studies are needed to assess the potential efficacy of EPA supplementation in preventing polyps in the chemoprevention of colorectal cancer.
Retention of Mitochondria in Mature Human Red Blood Cells as the Result of Autophagy Impairment in Rett Syndrome
Rett Syndrome (RTT), which affects approximately 1:10.000 live births, is a X-linked pervasive neuro-developmental disorder which is caused, in the vast majority of cases, by a sporadic mutation in the Methyl-CpG-binding protein-2 (MeCP2) gene. This is a transcriptional activator/repressor with presumed pleiotropic activities. The broad tissue expression of MeCP2 suggests that it may be involved in several metabolic pathways, but the molecular mechanisms which provoke the onset and progression of the syndrome are largely unknown. In this paper, we report that primary fibroblasts that have been isolated from RTT patients display a defective formation of autophagosomes under conditions of nutrient starvation and that the mature Red Blood Cells of some RTT patients retain mitochondria. Moreover, we provide evidence regarding the accumulation of the p62/SQSTM1 protein and ubiquitin-aggregated structures in the cerebellum of Mecp2 knockout mouse model ( Mecp2 −/ y ) during transition from the non-symptomatic to the symptomatic stage of the disease. Hence, we propose that a defective autophagy could be involved in the RTT clinical phenotype, which introduces new molecular perspectives in the pathogenesis of the syndrome.
Effects of oral administration of common antioxidant supplements on the energy metabolism of red blood cells. Attenuation of oxidative stress-induced changes in Rett syndrome erythrocytes by CoQ10
Nutritional supplements are traditionally employed for overall health and for managing some health conditions, although controversies are found concerning the role of antioxidants‐mediated benefits in vivo. Consistently with its critical role in systemic redox buffering, red blood cell (RBC) is recognized as a biologically relevant target to investigate the effects of oxidative stress. In RBC, reduction of the ATP levels and adenylate energy charge brings to disturbance in intracellular redox status. In the present work, several popular antioxidant supplements were orally administrated to healthy adults and examined for their ability to induce changes on the energy metabolism and oxidative status in RBC. Fifteen volunteers (3 per group) were treated for 30 days per os with epigallocatechin gallate (EGCG) (1 g green tea extract containing 50% EGCG), resveratrol (325 mg), coenzyme Q10 (CoQ10) (300 mg), vitamin C (1 g), and vitamin E (400 U.I.). Changes in the cellular levels of high-energy compounds (i.e., ATP and its catabolites, NAD and GTP), GSH, GSSG, and malondialdehyde (MDA) were simultaneously analyzed by ion-pairing HPLC. Response to oxidative stress was further investigated through the oxygen radical absorptive capacity (ORAC) assay. According to our experimental approach, (i) CoQ10 appeared to be the most effective antioxidant inducing a high increase in ATP/ADP, ATP/AMP, GSH/GSSG ratio and ORAC value and, in turn, a reduction of NAD concentration, (ii) EGCG modestly modulated the intracellular energy charge potential, while (iii) Vitamin E, vitamin C, and resveratrol exhibited very weak effects. Given that, the antioxidant potential of CoQ10 was additionally assessed in a pilot study which considered individuals suffering from Rett syndrome (RTT), a severe X-linked neuro-developmental disorder in which RBC oxidative damages provide biological markers for redox imbalance and chronic hypoxemia. RTT patients (n = 11), with the typical clinical form, were supplemented for 12 months with CoQ10 (300 mg, once daily). Level of lipid peroxidation (MDA production) and energy state of RBCs were analyzed at 2 and 12 months. Our data suggest that CoQ10 may significantly attenuate the oxidative stress-induced damage in RTT erythrocytes.
68Ga-DOTANOC: biodistribution and dosimetry in patients affected by neuroendocrine tumors
Objectives The aim of this work was the evaluation of biodistribution and radiation dosimetry of 68 Ga-DOTANOC in patients affected by neuroendocrine tumors. Materials and methods We enrolled nine patients (six male and three female) affected by different types of neuroendocrine tumors (NETs). Each patient underwent four whole body positron emission tomography (PET) scans, respectively, at 5, 20, 60, and 120 min after the intravenous injection of about 185 MBq of 68 Ga-DOTANOC. Blood and urine samples were taken at different time points post injection: respectively, at about 5, 18, 40, 60, and 120 min for blood and every 40–50 min from injection time up to 4 h for urine. The organs involved in the dosimetric evaluations were liver, heart, spleen, kidneys, lungs, pituitary gland, and urinary bladder. Dosimetric evaluations were done using the OLINDA/EXM 1.0 software. Results A physiological uptake of 68 Ga-DOTANOC was seen in all patients in the pituitary gland, the spleen, the liver, and the urinary tract (kidneys and urinary bladder). Organs with the highest absorbed doses were kidneys . The mean effective dose equivalent (EDE) was . Discussion and conclusions The excretion of the compound was principally via urine, giving dose to the kidney and the urinary bladder wall. As SSTR2 is the most frequently expressed somatostatin receptor and 68 Ga-DOTANOC has high affinity to it, this compound might play an important role in PET oncology in the future. The dosimetric evaluation carried out by our team demonstrated that 68 Ga-DOTANOC delivers a dose to organs comparable to, and even lower than, analogous diagnostic compounds.
Early Onset of Lipid Peroxidation after Human Traumatic Brain Injury: A Fatal Limitation for the Free Radical Scavenger Pharmacological Therapy?
Background On the basis of the contradiction between data on experimental head trauma showing oxidative stress-mediated cerebral tissue damage and failure of the majority of clinical trials using free radical scavenger drugs, we monitored the time-course changes of malondialdehyde (MDA, an index of cell lipid peroxidation), ascorbate, and dephosphorylated ATP catabolites in cerebrospinal fluid (CSF) of traumatic brain-injured patients. Methods CSF samples were obtained from 20 consecutive patients suffering from severe brain injury. All patients were comatose, with a Glasgow Coma Scale on admission of 6±1. The first CSF sample for each patient was collected within a mean value of 2.95 hours from trauma (SD=1.98), after the insertion of a ventriculostomy catheter for the continuous monitoring of intracranial pressure. During the next 48 hours, CSF was withdrawn from each patient once every 6 hours. All samples were analyzed by an ion-pairing high-performance liquid chromatographic method for the simultaneous determination of MDA, ascorbic acid, hypoxanthine, xanthine, uric acid, inosine, and adenosine. Results In comparison with values recorded in 10 herniated-lumbar-disk, noncerebral control patients, data showed that all CSF samples of brain-injured patients had high values (0.226 μmol/L; SD=0.196) of MDA (undetectable in samples of control patients) and decreased ascorbate levels (96.25 μmol/L; SD=31.74), already at the time of first withdrawal at the time of hospital admission. MDA was almost constant in the next two withdrawals and tended to decrease thereafter, although 48 hours after hospital admission, a mean level of 0.072 μmol/L CSF (SD=0.026) was still recorded. The ascorbate level was normalized 42 hours after hospital admission. Changes in the CSF values of ATP degradation products (oxypurines and nucleosides) suggested a dramatic alteration of neuronal energy metabolism after traumatic brain injury. Conclusions On the whole, these data demonstrate the early onset of oxygen radical-mediated oxidative stress, proposing a valid explanation for the failure of clinical trials based on the administration of oxygen free radical scavenger drugs and suggesting a possible rationale for testing the efficacy of lipid peroxidation “chain breakers” in future clinical trials.
Early effects of gliadin on enterocyte intracellular signalling involved in intestinal barrier function
Background and aims: Despite the progress made in understanding the immunological aspects of the pathogenesis of coeliac disease (CD), the early steps that allow gliadin to cross the intestinal barrier are still largely unknown. The aim of this study was to establish whether gliadin activates a zonulin dependent enterocyte intracellular signalling pathway(s) leading to increased intestinal permeability. Methods: The effect of gliadin on the enterocyte actin cytoskeleton was studied on rat intestinal epithelial (IEC-6) cell cultures by fluorescence microscopy and spectrofluorimetry. Zonulin concentration was measured on cell culture supernatants by enzyme linked immunosorbent assay. Transepithelial intestinal resistance (Rt) was measured on ex vivo intestinal tissues mounted in Ussing chambers. Results: Incubation of cells with gliadin led to a reversible protein kinase C (PKC) mediated actin polymerisation temporarily coincident with zonulin release. A significant reduction in Rt was observed after gliadin addition on rabbit intestinal mucosa mounted in Ussing chambers. Pretreatment with the zonulin inhibitor FZI/0 abolished the gliadin induced actin polymerisation and Rt reduction but not zonulin release. Conclusions: Gliadin induces zonulin release in intestinal epithelial cells in vitro. Activation of the zonulin pathway by PKC mediated cytoskeleton reorganisation and tight junction opening leads to a rapid increase in intestinal permeability.
Effects of increasing times of incomplete cerebral ischemia upon the energy state and lipid peroxidation in the rat
Different times of incomplete cerebral ischemia (2, 4, 6, 8, 10 and 30 min) were induced by bilateral common carotid artery occlusion in anesthetized rats to evaluate the time course of changes in lipid peroxidation and energy metabolism. Analysis of malondialdehyde (used to assess the levels of lipid peroxidation), ascorbic acid, oxypurines, nucleosides, nicotinic coenzymes and high-energy phosphates, was carried out by high-performance liquid chromatography on neutralized perchloric acid extract of brain tissue. Under the present experimental conditions, malondialdehyde, nicotinic coenzymes and ATP catabolites (oxypurines and nucleosides) were affected by increasing times of ischemia, with respect to control sham-operated rats. In particular, the concentration of malondialdehyde, undetectable in control brains, increased from 1.26 nmol/g wet weight after 2 min of carotid clamping to 13.42 nmol/g wet weight at the end of 30 min of incomplete cerebral ischemia. The presence of oxidative stress was further supported by ascorbic acid depletion, which was particularly significant after 10 and 30 min of incomplete ischemia. Carotid clamping provoked an imbalance between energy production and consumption that was evidenced by a reduction in ATP and GTP concentrations and an increase in ATP degradation products such as AMP, oxypurines and nucleosides. A decrement in the sum of adenine nucleotides and the energy charge potential indicated a progressive malfunctioning of energy-producing metabolic cycles. A possible contribution to such a severe change in energy state might be related to depletion of NAD and NADP, particularly noticeable after the longest incomplete brain ischemia times, that should have provoked a consequent lessening of oxido-reductive reactions. Bilateral carotid clamping causes a significant reduction in brain oxygen and substrate supply that results in inhibition of energy metabolism and triggering of oxygen-radical-induced lipid peroxidation.
All the Faces of Research on Borderline Personality Pathology: Drawing Future Trajectories through a Network and Cluster Analysis of the Literature
\"Borderline Personality Disorder is a severe condition that affects self and interpersonal dimensions and emotional and behavioral regulation. Since the last decades of the 20th century, an impressive amount of research and clinical contributions on BPD came from specific fields such as psychiatry, clinical psychology, psychopharmacology, and, more recently, cognitive neuroscience. All contributions tackled the challenges of finding reliable diagnostic categories, highlighting detailed developmental trajectories, and fostering effective treatment protocols. However, as results come from different areas, it is often challenging to depict a coherent and yet multifaceted framework on this topic. In this study, we conducted a scientometric analysis of the available literature on BPD to provide a systematic and comprehensive overview of research on BPD and emphasize historical changes, intertwining between fields and new areas of investigation. Results clearly show the evolution of research on BPD starting from the initial development of the construct, passing through the studies on treatment efficacy, the results of longitudinal studies, the advances in cognitive neurosciences, and the recent dimensional conceptualization in DSM-5. Moreover, it emphasizes promising areas of investigation, such as the relations of BPD with NSSI, ADHD, and vulnerable features of narcissism.\"
Regeneration beneath a dioecious tree species (Spondias purpurea) in a Mexican tropical dry forest
In dioecious plant species different frugivore activity between genders may influence the abundance and richness of the seedling banks underneath their canopies throughout seed removal and dispersal. In the tropical dry forest of Chamela, on the Pacific Coast of Mexico, the role of S. purpurea female trees as nucleation sites of regeneration was investigated. The standing density, species richness and dispersal syndrome of woody seedlings (i.e. trees and shrubs, 10–100 cm tall) recruited underneath and outside the canopy of 10 male and 10 female S. purpurea trees were recorded in a total of 160 1-m2 plots. Total density was greater in seedling communities associated with female trees (i.e. underneath and outside their canopies) as compared with male trees (231 vs. 153 seedlings, respectively); whereas overall species richness was greater underneath female canopies. Further, the density of zoochorous species were greater underneath the canopy of S. purpurea females (range = 0–5 plants m−2), than elsewhere (outside female canopies, range = 0–3 plants m−2; underneath and outside male canopies, range = 0–2 plants m−2), suggesting a directional dispersal bias towards them. Females of dioecious plant species may act as nucleation sites of initial seedling recruitment in tropical dry forests.
Effects of the Physical Environment and Primate Gut Passage on the Early Establishment of Ampelocera hottlei Standley in Rain Forest Fragments
The regeneration of many tropical trees is threatened by forest fragmentation because it produces major physical, biological and ecological changes that limit seed germination and seedling establishment. We analyzed the regenerative potential of an old growth forest tree species—Ampelocera hottlei (Ulmaceae)—in three contrasting habitats located in the Lacandona rain forest, southeastern Mexico: continuous forest, fragments occupied by black howler monkeys (Alouatta pigra) and fragments unoccupied by howlers. We tested if germination of A. hottlei seeds among habitats was affected by understory temperature, light incidence and ingestion by A. pigra. We compared seedling survival and relative growth rate in height (RGR H ) for 20 d among habitats and between ingested and control seeds (from mature fruits). Germination was higher in continuous forest than in fragments (occupied or not), with higher germination rates for ingested seeds in fragments. Temperature and light incidence were lower in continuous forest than in fragments. Germination decreased with increasing temperature and light incidence with this relationship being significantly higher for ingested seeds. Seedling survival was higher in continuous forest than in fragments, whereas RGR H did not differ among habitats. In addition, survival and RGR H were higher in seedlings originating from ingested seeds. Overall, our results suggest that the populations of A. hottlei can be limited in fragments where changes in the understory physical environment and the extirpation of A. pigra will likely have deleterious consequences for the regeneration of A. hottlei and possibly for other tree species, ultimately affecting forest composition and structure.