L’ansa pancreatica: une cause rare de pancréatite aigue

L’ansa pancréatica est une voie de communication accessoire entre le canal de Wirsung et un conduit pancréatique accessoire ne présentant pas de jonction normale avec le premier. L’association entre cette variante anatomique et la pancréatite aigue dite idiopathique reste hypothétique. Nous rapportons l’observation d’un patient présentant des poussées de pancréatites récidivantes qui serait en rapport avec une Ansa pancréatica.Pan African Medical Journal 2012; 13:3

Prophylactic Coloprotective Effect of <i>Urtica dioica</i> Leaves against Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis in Rats

Background and Objectives: Urtica dioica, a source of bioactive functional compounds, provides nutritional and gastrointestinal therapeutic benefits. This study attempted to investigate the prophylactic coloprotective action of an aqueous extract of Urtica dioica (AEUD) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Materials and Methods: Phenolic compounds, total sugar, and mineral levels were determined in AEUD. Then, AEUD at different doses (50, 100, and 200 mg/kg, BW, p.o.) and mesalazine (MESA) as a standard treatment (100 mg/kg, BW, p.o.) were given orally for 21 days. Acute colitis was induced by administering drinking water with 5% (w/v) DSS for 7 days. Body weight variation, fecal occult blood, and stool consistency were determined daily. The severity of colitis was graded according to colon length, disease activity index (DAI), histological evaluations, and biochemical alterations. Rats orally administered DSS regularly developed clinical and macroscopic signs of colitis. Results: Due to its richness in phenolic and flavonoid compounds (247.65 ± 2.69 mg EAG/g MS and 34.08 ± 0.53 mg EQt/g MS, respectively), AEUD markedly ameliorated DAI, ulcer scores, colon length shortening, colonic histopathological changes, and hematological and biochemical modifications. Taken together, AEUD treatment notably (p 2O2 production and stimulating the effect of enzyme antioxidants as well as attenuating inflammation by decreasing CRP levels by 79.5% between the DSS and DSS + AEUD-50 groups compared to the MESA group (75.6%). Conclusions: AEUD was sufficient to exert a coloprotective effect that might be influenced by its bioactive compounds’ anti-inflammatory and antioxidant capabilities

Fine tuning of tissues' viscosity and surface tension through contractility suggests a new role for α-catenin.

What governs tissue organization and movement? If molecular and genetic approaches are able to give some answers on these issues, more and more works are now giving a real importance to mechanics as a key component eventually triggering further signaling events. We chose embryonic cell aggregates as model systems for tissue organization and movement in order to investigate the origin of some mechanical constraints arising from cells organization. Steinberg et al. proposed a long time ago an analogy between liquids and tissues and showed that indeed tissues possess a measurable tissue surface tension and viscosity. We question here the molecular origin of these parameters and give a quantitative measurement of adhesion versus contractility in the framework of the differential interfacial tension hypothesis. Accompanying surface tension measurements by angle measurements (at vertexes of cell-cell contacts) at the cell/medium interface, we are able to extract the full parameters of this model: cortical tensions and adhesion energy. We show that a tunable surface tension and viscosity can be achieved easily through the control of cell-cell contractility compared to cell-medium one. Moreover we show that α-catenin is crucial for this regulation to occur: these molecules appear as a catalyser for the remodeling of the actin cytoskeleton underneath cell-cell contact, enabling a differential contractility between the cell-medium and cell-cell interface to take place

In-depth phenotypic characterization of multicellular tumor spheroids: Effects of 5-Fluorouracil.

MultiCellular Tumor Spheroids (MCTS), which mimic the 3-Dimensional (3D) organization of a tumor, are considered as better models than conventional cultures in 2-Dimensions (2D) to study cancer cell biology and to evaluate the response to chemotherapeutic drugs. A real time and quantitative follow-up of MCTS with simple and robust readouts to evaluate drug efficacy is still missing. Here, we evaluate the chemotherapeutic drug 5-Fluorouracil (5-FU) response on the growth and integrity of MCTS two days after treatment of MCTS and for three colorectal carcinoma cell lines with different cohesive properties (HT29, HCT116 and SW480). We found different sensitivity to 5-FU for the three CRC cell lines, ranging from high (SW480), intermediate (HCT116) and low (HT29) and the same hierarchy of CRC cell lines sensitivity is conserved in 2D. We also evidence that 5-FU has a strong impact on spheroid cohesion, with the apparition of a number of single detaching cells from the spheroid in a 5-FU dose- and cell line-dependent manner. We propose an innovative methodology for the chemosensitivity evaluation in 3D MCTS that recapitulates and regionalizes the 5-FU-induced changes within MCTS over time. These robust phenotypic read-outs could be easily scalable for high-throughput drug screening that may include different types of cancer cells to take into account tumor heterogeneity and resistance to treatment

High-Frequency Mechanical Properties of Tumors Measured by Brillouin Light Scattering

International audienceThe structure of tumors can be recapitulated as an elastic frame formed by the connected cytoskeletons of the cells invaded by interstitial and intracellular fluids. The low-frequency mechanics of this poroelastic system, dictated by the elastic skeleton only, control tumor growth, penetration of therapeutic agents, and invasiveness. The high-frequency mechanical properties containing the additional contribution of the internal fluids have also been posited to participate in tumor progression and drug resistance, but they remain largely unexplored. Here we use Brillouin light scattering to produce label-free images of tumor microtissues based on the high-frequency viscoelastic modulus as a contrast mechanism. In this regime, we demonstrate that the modulus discriminates between tissues with altered tumorigenic properties. Our micrometric maps also reveal that the modulus is heterogeneously altered across the tissue by drug therapy, revealing a lag of efficacy in the core of the tumor. Exploiting high-frequency poromechanics should advance present theories based on viscoelasticity and lead to integrated descriptions of tumor response to drugs

Contractility dependent TST still predicts sorting out and envelopment.

<p>Phase contrast and fluorescence images representing configurations at different stages of the sorting out (A–C) and envelopment (D–F) processes. (A–B) Phase contrast and fluorescence images correspond to 72 hours after mixing <u>F9</u> and F9 dissociated cells in hanging drops. (C) Control fluorescence of a <u>F9</u>/F9 mixture after 72 hours. (D–E) Engulfment of a <u>F9</u>/F9 pair of aggregates 3 hours (D) and 29 hours (E) after the aggregates were brought in contact and allowed to fuse. (F) Final configuration (72 hours) of a <u>F9</u>/F9 pair of aggregates (control). Left right thick double arrow indicates simultaneous recording in phase and fluorescence. Rightwards thick arrow indicates evolution with time. Scale bars, 100m.</p

F9 versus F9.

<p>Cross sections of a F9 WT aggregate (A) and of a F9 aggregate (B). The staining is for -catenin, scale bars, 10 . (C) Schematic representation of the cortical contractions at the cell-extracellular medium interface (), at the cell-cell interface () and of the adhesion energy J. and increase the tissue surface tension, whereas decreases it (see Eq. 2). (D) Closer view of two F9 cells in contact. The difference between the interfacial tensions at the cell-cell and cell-extracellular medium interfaces gives the aggregate surface tension (). increases the surface tension whereas decreases it. Scale bar, 5 . (E-F) Cartoons of cell-cell contacts in the case of F9 WT cells (E) and F9 cells (F). The presence of -catenin at cell-cell junction is described as a catalyzer for actin reorganization at cell-cell junctions.</p