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The role of glucagon-like peptide 2 (GLP2) in colon tissue has been studied extensively, from the time it was discovered that GLP2 promotes intestinal growth. A large number of studies have shown potential applications for GLP2 in human therapy. However, recent data have suggested the notion that GLP2 plays a key role in colon carcinogenesis. Questions have been arisen regarding the pro-proliferative effects of GLP2 and whether they might promote intestinal healing or advance colon tumor growth. Here, we provide striking evidence to show that the physiological activities of GLP2 are closely related to cancer-related molecular pathways that have been shown to circumvent drug desensitization. We further explore the different pathways of GLP2-signaling to suggest suitable GLP2-based therapeutic strategies in colon cancer., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Absence of enteric neurons is associated with thickening of the intestinal muscularis externa in Chagas' disease. The thickening is due to hyperplasia and hypertrophy of the smooth muscle cells and increased extracellular matrix components. The influence of the nervous system on the structure of the smooth muscle cells and its associated matrix has been poorly investigated. An experimental model of denervation of the ileum in rats was performed by application of the surfactant agent benzalkonium chloride that selectively destroys the myenteric plexus. Three months later, ileal tissue samples were obtained and studied by histochemistry and transmission electron microsocopy. Sham operated rats were used as controls. The diameter of collagen fibrils was evaluated in electron micrographs. The histopathological analysis showed thickening of the muscular layer. The thin and weakly arranged collagen and reticulin fibers surrounding the smooth muscle cells, observed in control cases by Picrosirius polarization (PSP) stain method, corresponded to a population of loosely packed thin collagen fibrils of uniform diameters (mean=29.16 nm) at the ultrastructural level. In contrast, the thick and strongly birefringent fibers around the muscle cells, observed in the treated group, stained by PSP, corresponded to densely packed thicker fibrils with large variation in diameter (mean=39.41 nm). Comparison of the data demonstrated statistically significant difference between the groups suggesting that the replacement of loosely arranged reticulin fibers by fibrous tissue (with typical collagen fiber), may alter the biomechanical function resulting in impairment of muscular contraction.

Therapeutic ultrasound (TUS) is a widely used coadjuvant physical means to promote biological tissue repair. In the present investigation, the influence of TUS on the integration of full-thickness skin graft was studied in rabbits. Twenty female adult rabbits were used and two 2x2-cm square full-thickness skin grafts were obtained from both scapular regions and swapped, the one cut out on the right being placed on the left and vice versa. The graft on the right was irradiated with TUS (3 MHz, 0.5 W/cm2, 5-min duration) once a day for seven consecutive days, beginning on the third postoperative day; the graft on the left was submitted to simulated irradiation. The animals were killed on the 11th day and the grafted areas were resected (graft+safety margin) for histological examination. Five-mum-thick sections were alternatively stained with Gomori's trichrome, proliferating cell nuclear antigen (PCNA) and picrosirius red and examined under the light microscope, and the epidermal and dermal areas were measured and proliferating cells and new blood vessels counted. The results showed a significant increase (p=0.007) in the number of proliferating epidermal cells (12.18% and 7.34% of the total number of cells in the irradiated and control grafts, respectively) and new blood vessels per field (p=0.0001) in the irradiated grafts (6.27 compared with 3.07). Despite the increased number of proliferating cells and blood vessels, there was no significant difference between the epidermis (246,392 microm2 and 200,626 microm2 in groups 1 and 2, respectively; p=0.07) and dermis (2,157,730 microm2 and 2,109,150 microm2 in groups 1 and 2, respectively; p=0.21) areas as a function of thickness for both groups. We conclude that TUS induces morphological alterations in biological processes, such as epidermic germinative layer cell proliferation and neoangiogenesis, which are involved in the integration of full-thickness skin grafts. This has a potential for clinical use in humans.