the colon epithelium as a target for the intracellular antioxidant activity of hydroxytyrosol a study on rat colon explants

Abstract The study aimed at investigating the intracellular antioxidant activity of hydroxytyrosol (HT), one of the most potent natural antioxidant phenolic compounds, directly on the colon epithelium, under basal physiological and pro-oxidant conditions. In situ confocal microscopy on rat colon explants loaded with the ROS sensitive fluorescent probe CM-H2DCFDA was applied. HT exerted a dose-dependent decrease of the basal ROS production of superficial colonocytes. Also, it induced a dose-dependent antioxidant action on the colon mucosa exposed to an H2O2 challenge. The effect of 100 µM HT was comparable to that of 10 µM Trolox. The HT effect was also tested against tert-butyl peroxide, another pro-oxidant. The results showed that HT can directly contribute to the redox balance of colonic epithelium by reducing ROS in both basal and pro-oxidant conditions, and support the potential of HT as a functional food ingredient with applications in protecting the intestinal mucosa against oxidative stress

Performance of the diamond active target prototype for the PADME experiment at the DAΦ\PhiNE BTF

The PADME experiment at the DA$\Phi$NE Beam-Test Facility (BTF) is designed to search for the gauge boson of a new $\rm U(1)$ interaction in the process e$^+$e$^-\rightarrow\gamma$+$\rm A'$, using the intense positron beam hitting a light target. The $\rm A'$, usually referred as dark photon, is assumed to decay into invisible particles of a secluded sector and it can be observed by searching for an anomalous peak in the spectrum of the missing mass measured in events with a single photon in the final state. The measurement requires the determination of the 4-momentum of the recoil photon, performed by a homogeneous, highly segmented BGO crystals calorimeter. A significant improvement of the missing mass resolution is possible using an active target capable to determine the average position of the positron bunch with a resolution of less than 1 mm. This report presents the performance of a real size $\rm (2x2 cm^2)$ PADME active target made of a thin (50 $\mu$m) diamond sensor, with graphitic strips produced via laser irradiation on both sides. The measurements are based on data collected in a beam test at the BTF in November 2015.Comment: 7 pages, 10 figure

Radiation Damage of Polycrystalline CVD Diamond with Graphite Electrical Contacts

In this work we show preliminary results of radiation damage for a polycrystalline diamond with graphite contacts in terms of time response after 62 MeV protons irradiation for a total fluence of (2.0±0.08)×1015 protons/cm2. In addition, we describe the realization of a new type of device made with graphite micro-strips by laser micro-writing on diamond surface. In this way we made 20 graphite micro-strips of width about 87 m and spacing between each other of about 60 $\mu$m

Diamond detectors with electrodes graphitized by means of laser

In the last years there has been an increase of interest in diamond devices because of the promising applications in different field, such as high-energy physics, radiotherapy and biochemical applications. In particular, a new frontier is represented by the realization of full-carbon detectors characterized by graphite electrodes, which give to the devices considerable advantages like high radiation hardness, perfect mechanical adhesion and good charge collection properties. In this paper the manufacturing of full-carbon devices and their detection performances are illustrated and compared to a reference diamond detector characterized by traditional electrodes

The colon epithelium as a target for the intracellular antioxidant activity of hydroxytyrosol: a study on rat colon explants

Oxidative stress is involved in the genesis and progress of many disorders of the gastrointestinal (GI) tract. In particular, the colon epithelium is one of the GI tract segments more exposed to pro-oxidant conditions. We aimed to study the intracellular antioxidant activity of hydroxytyrosol (HT), one of the most potent natural antioxidant phenolic compounds typically present in olive oil, directly on the colon epithelium, under basal physiological and pro-oxidant conditions. Our approach was based on the application of in situ confocal microscopy on rat colon explants loaded with the fluorescent probe 5-(and-6)-chloromethyl-2’,7’-dichlorodihydrofluoresceindiacetate, which is sensitive to intracellular oxidative stress. In the intact mucosa, HT exerted a dose-dependent decrease of the basal intracellular reactive oxygen species (ROS) production of superficial colonocytes. Also, it induced a direct dose-dependent antioxidant action on the colon mucosa exposed to a pro-oxidant condition such as the H2O2 challenge. The effect of 100 µM HT was comparable to that of 10 µM Trolox, which is widely used as a standard in in vitro assays for the determination of antioxidant activity. The intracellular antioxidant activity of HT on the intact mucosa was also tested against tert-butyl peroxide, another pro-oxidant. The results show that HT can directly contribute to the redox balance of colonic epithelium by reducing ROS in both basal and pro-oxidant conditions, and support the potential of HT as a functional food ingredient with applications in protecting the intestinal mucosa against oxidative stress

Ultrasound-assessed lung aeration correlates with respiratory system compliance in adults and neonates with acute hypoxemic restrictive respiratory failure: an observational prospective study

Background: Lung ultrasound allows lung aeration to be assessed through dedicated lung ultrasound scores (LUS). Despite LUS have been validated using several techniques, scanty data exist about the relationships between LUS and compliance of the respiratory system (Crs) in restrictive respiratory failure. Aim of this study was to investigate the relationship between LUS and Crs in neonates and adults affected by acute hypoxemic restrictive respiratory failure, as well as the effect of patients' age on this relationship. Methods: Observational, cross-sectional, international, patho-physiology, bi-center study recruiting invasively ventilated, adults and neonates with acute respiratory distress syndrome (ARDS), neonatal ARDS (NARDS) or respiratory distress syndrome (RDS) due to primary surfactant deficiency. Subjects without lung disease (NLD) and ventilated for extra-pulmonary conditions were recruited as controls. LUS, Crs and resistances (Rrs) of the respiratory system were measured within 1 h from each other. Results: Forty adults and fifty-six neonates were recruited. LUS was higher in ARDS, NARDS and RDS and lower in control subjects (overall p < 0.001), while Crs was lower in ARDS, NARDS and RDS and higher in control subjects (overall p < 0.001), without differences between adults and neonates. LUS and Crs were correlated in adults [r = - 0.86 (95% CI - 0.93; - 0.76), p < 0.001] and neonates [r = - 0.76 (95% CI - 0.85; - 0.62), p < 0.001]. Correlations remained significant among subgroups with different causes of respiratory failure; LUS and Rrs were not correlated. Multivariate analyses confirmed the association between LUS and Crs both in adults [B = - 2.8 (95% CI - 4.9; - 0.6), p = 0.012] and neonates [B = - 0.045 (95% CI - 0.07; - 0.02), p = 0.001]. Conclusions: Lung aeration and compliance of the respiratory system are significantly and inversely correlated irrespective of patients' age. A restrictive respiratory failure has the same ultrasound appearance and mechanical characteristics in adults and neonates

Beam test results of PADME full carbon active diamond target

A full carbon diamond detector is proposed for the active target of PADME, an experiment which uses the positron beam of the BTF (Beam Test Facility) at the Laboratori Nazionali di Frascati to search for the production of dark photons in e+e− annihilation (M. Raggi et al., Adv. High Energy Phys. 2014 (2014) 959802). This paper presents the preliminary results of a beam test done in November 2015 of the PADME active target prototyp

Bevacizumab in association with de Gramont 5-fluorouracil/folinic acid in patients with oxaliplatin-, irinotecan-, and cetuximab-refractory colorectal cancer: a single-center phase 2 trial.

BACKGROUND: The aim of the current study was the investigation of the value of bevacizumab+5-fluorouracil(5-FU)/folinic acid in patients with advanced colorectal cancers who have exhausted standard chemotherapy options. METHODS: The authors included 48 heavily pretreated patients (colon:rectum, 33:15; men:women, 23:25; median age, 63 years; range, 27-79 years) whose disease had progressed during or within an oxaliplatin-based first-line chemotherapy, an irinotecan-based second-line regimen, and a third-line treatment with cetuximab plus weekly irinotecan. Bevacizumab was given at a dose of 5 mg/kg. 5-FU/folinic acid was administered according to the de Gramont schedule. RESULTS: The response rate was 6.25%, and 30.4% of patients demonstrated stable disease as the best response. The median time to disease progression was 3.5 months (95% confidence interval [95% CI], 2.3-6.9 months), and the median survival time was 7.7 months (95% CI, 3.9-11.9 months). The most common grade 3 to 4 side toxicities (graded according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) were: diarrhea (20.8%), fatigue (14.5%), and stomatitis (12.5%). Grade 3 to 4 hemorrhage occurred in 8 patients (16.6%), including 4 cases of bleeding in the gastrointestinal tract. Other relatively common adverse events such as hypertension, thrombosis, and bowel perforation were reported in 50%, 18.7%, and 4.16%, of patients respectively. CONCLUSIONS: The data from the current study suggest a modest but significant clinical benefit of bevacizumab+de Gramont schedule in heavily pretreated colorectal cancer patients. Copyright (c) 2009 American Cancer Society