Background: Pigs are frequently used as animal models in experimental medicine. To identify processes of vascular development or regression, vascular elements

Objective: Abdominal aortic aneurysm (AAA) is a serious disease due to its covert nature, relatively high prevalence and fatal prognosis in the case of rupture. To obtain new insights into AAA pathogenesis, we examined the relationships between histopathology, multiplex in vitro immunoassay data, diameter and symptomatology. Methods: In a prospective, non-randomised study, we evaluated samples from 6 normal infrarenal aortae and 65 AAA patients (65 walls, 55 thrombi). The AAA patients were either asymptomatic (n = 44), symptomatic (n = 7) or with ruptured AAA (n = 14). The AAA diameter was classified as small (<5 cm, n = 18), medium (5–7 cm, n = 26) and large (>7 cm, n = 21). We quantified the histopathology of the AAA wall and the adjacent thrombus. We assessed the expression of proteins in the same samples. Results: Asymptomatic AAAs had walls with more abundant inflammatory infiltrates, lower amounts of PAI-1, a higher number of tPA-positive elements, a tendency towards decreased collagen content, whereas the adjacent thrombi had a greater concentration of VCAM-1 and MMP-2 when compared with symptomatic AAAs. Compared with the aneurysmatic aorta, the normal aorta contained less collagen and more elastin, actin, desmin and PAI-1-positive elements; in addition, it was more vascular. Medium-sized AAAs were the most actin and vimentin rich, and large AAAs were the most vascular. Conclusion: Our results show that asymptomatic AAA walls often have more potentially deleterious histopathological alterations than symptomatic AAA walls. This result indicates that a progression from an asymptomatic AAA to rupture can be expected and screening patients who are at risk of rupture could be beneficial.

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In teaching and learning human anatomy, anatomical autopsy and prosected specimens have always been indispensable. However, alternative methods must often be used to demonstrate particularly delicate structures. Corrosion casting of porcine organs with Biodur E20 Plus is valuable for teaching and learning both gross anatomy and, uniquely, the micromorphology of cardiovascular, respiratory, digestive, and urogenital systems. Assessments of casts with a stereomicroscope and/or scanning electron microscope as well as highlighting cast structures using color coding help students to better understand how the structures that they have observed as two-dimensional images actually exist in three dimensions, and students found using the casts to be highly effective in their learning. Reconstructions of cast hollow structures from (micro-)computed tomography scans and videos facilitate detailed analyses of branching patterns and spatial arrangements in cast structures, aid in the understanding of clinically relevant structures and provide innovative visual aids. The casting protocol and teaching manual we offer can be adjusted to different technical capabilities and might also be found useful for veterinary or other biological science classes.

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Background: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. Materials and Methods: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. Results: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. Conclusion: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.Pancreatic cancer is one of the leading causes of cancer mortality in developed countries; its incidence has been rising over last decades and without a breakthrough in therapy this trend is expected to continue (1, 2). The incidence of pancreatic cancer is almost equal to its mortality rate and the estimated 5-year survival rate is only 5% (1, 3).Nowadays the only potential curative therapy of this disease is radical surgical resection, which can help to increase the 5year survival rate up to 25% (4). The standard surgical method for curative resection of tumours arising in the head of the pancreas is pylorus-preserving pancreaticoduodenectomy (PPPD) (5). However, the resectability of pancreatic cancer is limited by vessel infiltration. In the presence of tumour ingrowth into adjacent arteries, surgical resection is not generally recommended due to high postoperative morbidity and mortality (4, 6). However, tumours infiltrating venous structures [such as the superior mesenteric vein (SMV), and portal vein (PV)] can be safely resected together with involved part of the vein, resulting in morbidity and mortality comparable with standard PPPD (4, 7).Resection of either PV or SMV during PPPD requires a suitable reconstruction of the involved vessel. In cases when only a tangential resection or short segmental resection is performed, the vein can be reconstructed by venorrhaphy, patch plasty or primary anastomosis. When a longer venous 6603

Bone regeneration after injury or after surgical bone removal due to disease is a serious medical challenge. A variety of materials are being tested to replace a missing bone or tooth. Regeneration requires cells capable of proliferation and differentiation in bone tissue. Although there are many possible human cell types available for use as a model for each phase of this process, no cell type is ideal for each phase. Osteosarcoma cells are preferred for initial adhesion assays due to their easy cultivation and fast proliferation, but they are not suitable for subsequent differentiation testing due to their cancer origin and genetic differences from normal bone tissue. Mesenchymal stem cells are more suitable for biocompatibility testing, because they mimic natural conditions in healthy bone, but they proliferate more slowly, soon undergo senescence, and some subpopulations may exhibit weak osteodifferentiation. Primary human osteoblasts provide relevant results in evaluating the effect of biomaterials on cellular activity; however, their resources are limited for the same reasons, like for mesenchymal stem cells. This review article provides an overview of cell models for biocompatibility testing of materials used in bone tissue research.