Study of wound healing dynamics by single pseudo-particle tracking in phase contrast images acquired in time-lapse

Cellular contacts modify the way cells migrate in a cohesive group with respect to a free single cell. The resulting motion is persistent and correlated, with cells’ velocities self-aligning in time. The presence of a dense agglomerate of cells makes the application of single particle tracking techniques to define cells dynamics difficult, especially in the case of phase contrast images. Here, we propose an original pipeline for the analysis of phase contrast images of the wound healing scratch assay acquired in time-lapse, with the aim of extracting single particle trajectories describing the dynamics of the wound closure. In such an approach, the membrane of the cells at the border of the wound is taken as a unicum, i.e., the wound edge, and the dynamics is described by the stochastic motion of an ensemble of points on such a membrane, i.e., pseudo-particles. For each single frame, the pipeline of analysis includes: first, a texture classification for separating the background from the cells and for identifying the wound edge; second, the computation of the coordinates of the ensemble of pseudo-particles, chosen to be uniformly distributed along the length of the wound edge. We show the results of this method applied to a glioma cell line (T98G) performing a wound healing scratch assay without external stimuli. We discuss the efficiency of the method to assess cell motility and possible applications to other experimental layouts, such as single cell motion. The pipeline is developed in the Python language and is available upon request

Study of Wound Healing Dynamics by Single Pseudo-Particle Tracking in Phase Contrast Images Acquired in Time-Lapse

Cellular contacts modify the way cells migrate in a cohesive group with respect to a free single cell. The resulting motion is persistent and correlated, with cells’ velocities self-aligning in time. The presence of a dense agglomerate of cells makes the application of single particle tracking techniques to define cells dynamics difficult, especially in the case of phase contrast images. Here, we propose an original pipeline for the analysis of phase contrast images of the wound healing scratch assay acquired in time-lapse, with the aim of extracting single particle trajectories describing the dynamics of the wound closure. In such an approach, the membrane of the cells at the border of the wound is taken as a unicum, i.e., the wound edge, and the dynamics is described by the stochastic motion of an ensemble of points on such a membrane, i.e., pseudo-particles. For each single frame, the pipeline of analysis includes: first, a texture classification for separating the background from the cells and for identifying the wound edge; second, the computation of the coordinates of the ensemble of pseudo-particles, chosen to be uniformly distributed along the length of the wound edge. We show the results of this method applied to a glioma cell line (T98G) performing a wound healing scratch assay without external stimuli. We discuss the efficiency of the method to assess cell motility and possible applications to other experimental layouts, such as single cell motion. The pipeline is developed in the Python language and is available upon request.Basque Government BERC 2018– 2021 Spanish Ministry of Economy and Competitiveness MINECO via the BCAM Severo Ochoa SEV-2017-0718 accreditatio

Network approaches to Genome-Wide Association studies

In the framework of large-scale genotypic studies (describing the distribution of allele frequencies inside human genome) we characterize the Linkage Disequilibrium (LD) matrix as a network of relationships between alleles. We propose a suitable matrix discretization threshold, after a characterization of the distribution of noisy values inside LD matrix. We compare the main network parameters of a real LD matrix with two null models (Erdos-Renyi random network and a rewiring of the original network), in order to highlight the peculiar features of the LD network. We conclude stating the need of adequate computing tools for handling the high-dimensional data coming from Genome-Wide genotyping datasets

PRELIMINARY DATA ON FUMONISINS PRESENCE IN PIG LIVER

Mycotoxins are heterogeneous chemical compounds characterized by a low molecular weight and synthesized by the secondary metabolism of different molds. Fumonisins are water-soluble mycotoxins produced by Fusarium species spoiling corn and derived products. These mycotoxins can enter the food chain also through the consumption of meat of exposed animals. Fumonisins and their metabolites have been associated with several animal and human diseases. They are suspected risk factors for esophageal and liver cancers, neural tube defects and cardiovascular problems. Improved methods are needed to accurately assess fumonisin concentrations in food from vegetable and animal origin to prevent acute and chronic human exposure. The aim of the present work was to develop a sensitive and selective method for quantification and unambiguous identification of fumonisin B1 (FB1), fumonisin B2 (FB2) and their complete hydrolyzed products (HFB1 and HFB2), in order to determine their presence in pig liver. Furthermore, the developed method was applied, in order to test its efficacy, on liver samples of weaned piglets fed a diet in compliance with the FB1 and FB2 contamination limits set by EU. All the samples showed the presence of at least one of the analytes. In particular FB1 was found in 5 out of 7 samples and the average level of contamination found was 28 ppb

Effets de la formation de la pourriture acide sur la composition de la fraction lipidique des différentes parties du grain de Vitis vinifera cv. Fortana

On a étudié par comparaison la composition de la fraction lipidique des différentes parties de grains de Vitis vinifera sains et attaqués par la pourriture acide.Des différences considérables ont été révélées entre les extraits des différents types d'échantillons de pulpe + peau en ce qui concerne les paramètres suivants: teneur en lipide, composition des triglycérides, composition des acides gras. Par contre, la fraction lipidique des deux échantillons de pépins était très semblable.Les composants principaux ainsi que leur répartition quantitative caractéristique correspondent aux résultats publiés dans une étude précédente. On a mis en évidence l'aldéhyde oléanoique qui n'était présente que dans quelques échantillons de pulpe + peau en même temps que l'acide correspondant et l'erythrodiol.Effects of sour rot on the composition of the lipid fraction of different parts of grapevine berries ( Vitis vinifera cv. Fortana)The composition of the lipid fraction of the various parts of berries of Vitis vinifera, healthy and infected by sour rot, have been compared. Notable differences became evident among the extracts of the various samples of pulp + skin with respect to the following parameters: lipid contens, composition of triglycerides and composition of fatty acids. The composition of the lipid fraction of the two samples of grape seeds, however, turned out to be very similar.The principal components and their quantitative distribution characteristics corresponded with the results reported in a preceding work. Oleanoic aldehyde has been identified which, together with the corresponding acid and erythrodiole, was only present in the samples of pulp + skin

Occurrence of Mycotoxins in Extruded Commercial Cat Food

The occurrence of the most important mycotoxins (deoxynivalenol, fumonisin B1 and B2, aflatoxins B1, B2, G1, and G2, ochratoxin A, zearalenone, T-2, and HT-2 toxins) was determined in 64 extruded cat foods purchased in Italy through ultra-performance liquid chromatography coupled with tandem mass spectrometry. Deoxynivalenol and fumonisins were the most common contaminants (quantified in 80 and 95% of the samples, respectively). Conversely, aflatoxins B2, G1, and G2 were not identified in any sample. Some cat foods exceeded the regulatory limit for aflatoxin B1 (n = 3) or the guidance values for zearalenone (n = 3), fumonisins (n = 2), ochratoxin A (n = 1), and T-2 (n = 1) recently established for pets in the European Union. A widespread co-occurrence of mycotoxins was observed (28, 42, and 8% of the samples contained quantifiable amounts of two, three, and four mycotoxins, respectively). This study describes criticisms regarding the mycotoxin issue in pet food and suggests an improvement of the monitoring of the pet food chain

DETERMINATION OF FUMONIS FB1 IN MILK BY LC-MS/MS

Mycotoxins are heterogeneous chemical compounds characterized by a low molecular weight and synthesized by the secondary metabolism of different molds. Fumonisins are water-soluble mycotoxins produced by Fusarium species spoiling corn and derived products. These mycotoxins can reach the human also indirectly through the consumption of food products derived from animals fed with contaminated feed. Fumonisins have been associated with several animal and human diseases. They are suspected risk factors for esophageal and liver cancers, neural tube defects and cardiovascular problems. Improved methods are needed to accurately assess fumonisin concentrations in food from vegetable and animal origin to prevent acute and chronic human exposure. The aim of the present work was to develop a sensitive and selective method for identification and quantification of fumonisin B1 (FB1) in milk. FB1 was isolated from milk, by a single step immunoaffinity column and was detected using liquid chromatography coupled with tandem mass spectrometry in positive electrospray ionization (ESI+). The analysis were carried out in multiple reaction monitoring (MRM) mode using the two main product ions. The good performances of the proposed method can assure a correct fumonisin detection in milk even at relatively low concentrations

Design and in vitro study of a dual drug-loaded delivery system produced by electrospinning for the treatment of acute injuries of the central nervous system

Vascular and traumatic injuries of the central nervous system are recognized as global health priorities. A polypharmacology approach that is able to simultaneously target several injury factors by the combination of agents having synergistic effects appears to be promising. Herein, we designed a polymeric delivery system loaded with two drugs, ibuprofen (Ibu) and thyroid hormone triiodothyronine (T3) to in vitro release the suitable amount of the anti-inflammation and the remyelination drug. As a production method, electrospinning technology was used. First, Ibuloaded micro (diameter circa 0.95–1.20 µm) and nano (diameter circa 0.70 µm) fibers were produced using poly(L-lactide) PLLA and PLGA with different lactide/glycolide ratios (50:50, 75:25, and 85:15) to select the most suitable polymer and fiber diameter. Based on the in vitro release results and in-house knowledge, PLLA nanofibers (mean diameter = 580 ± 120 nm) loaded with both Ibu and T3 were then successfully produced by a co-axial electrospinning technique. The in vitro release studies demonstrated that the final Ibu/T3 PLLA system extended the release of both drugs for 14 days, providing the target sustained release. Finally, studies in cell cultures (RAW macrophages and neural stem cell-derived oligodendrocyte precursor cells—OPCs) demonstrated the anti-inflammatory and promyelinating efficacy of the dual drug-loaded delivery platform

FOLFOX6 and bevacizumab in non-optimally resectable liver metastases from colorectal cancer

BACKGROUND: In patients with colorectal liver metastases (CLM) R0 resection significantly improves overall survival (OS). METHODS: In this report, we present the results of a phase II trial of FOLFOX6+bevacizumab in patients with non-optimally resectable CLM. Patients received six cycles of FOLFOX6+ five of bevacizumab. Patients not achieving resectability received six additional cycles of each. A PET-CT was performed at baseline and again within 1 month after initiating treatment. RESULTS: From September 2005 to July 2009, 21 patients were enrolled (Male/Female: 15/6; median age: 65 years). An objective response (OR) was documented in 12 cases (57.1%; complete responses (CRs): 3, partial response (PR): 9); one patient died from toxicity before surgery. Thirteen patients underwent radical surgery (61.9%). Three (23%) had a pathological CR (pCR). Six patients (46.1%) experienced minor postsurgical complications. After a median 38.8-month follow-up, the median OS was 22.5 months. Patients achieving at least 1 unit reduction in Standard uptake value (SUV)max on PET-CT had longer progression-free survival (PFS) (median PFS: 22 vs 14 months, P=0.001). CONCLUSIONS: FOLFOX6+bevacizumab does not increase postsurgical complications, yields high rates of resectability and pCR. Early changes in PET-CT seem to be predictive of longer PFS

Prognostic role of EGFR gene copy number and KRAS mutation in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy

Epidermal growth factor receptor (EGFR), evaluated by immunohistochemistry, has been shown to have prognostic significance in patients with colorectal cancer. Gene copy number (GCN) of EGFR and KRAS status predict response and outcome in patients treated with anti-EGFR therapy, but their prognostic significance in colorectal cancer patients is still unclear.We have retrospectively reviewed the baseline EGFR GCN, KRAS status and clinical outcome of 146 locally advanced rectal cancer (LARC) patients treated with preoperative chemoradiotherapy. Pathological response evaluated by Dworak's tumour regression grade (TRG), disease-free survival (DFS) and overall survival (OS) were analysed.Tumour regression grade 4 and TRG3-4 were achieved in 14.4 and 30.8\% of the patients respectively. Twenty-nine (19.9\%) and 33 patients (19.2\%) had an EGFR/nuclei ratio >2.9 and CEP7 polisomy >50\% respectively; 28 patients (19.2\%) had a KRAS mutation. Neither EGFR GCN nor KRAS status was statistically correlated to TRG. 5-year DFS and OS were 63.3 and 71.5\%, respectively, and no significant relation with EGFR GCN or KRAS status was found.Our data show that EGFR GCN and KRAS status are not prognostic factors in LARC treated with preoperative chemoradiation