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Tissue Engineering in Reconstruction and Regeneration of Visceral Organs
Published in Rajesh K. Kesharwani, Raj K. Keservani, Anil K. Sharma, Tissue Engineering, 2022
Soma Mondal Ghorai, Sudhanshu Mishra
The small intestine is segmented into three regions: these are the duodenum, jejunum, and ileum (Spoerri, 1949). Duodenum is the shortest of 25.4 cm and begins after the pyloric sphincter followed by jejunum of 0.9 m and ileum is the longest of about 1.8 m in length. Ileum is also the thickest and most vascular with well-developed folds than the other two. The entire intestine is innervated by parasympathetic nerve fibers from the vagus nerve and sympathetic nerve fibers from the thoracic splanchnic nerve. Intestine is also accompanied by a well-circulated portal system with the superior mesenteric artery and superior mesenteric vein as the main artery and vein to collect the nutrient-rich blood and carry it to the liver via the hepatic portal vein. Anatomically, intestine is composed of mucosa and submucosa and a highly absorptive surface area with numerous villi and microvilli and more than 600-fold, circular folds. Special lymphoid organ Peyer’s patches are seen within the submucosa of the intestine, which impart immunity from the invading pathogens (Figure 7.7A).
Antimicrobial activity of the recombinant peptide Melittin-Thanatin with three glycine to tryptophan mutations
Published in Preparative Biochemistry & Biotechnology, 2023
Yong Liu, Xiuping Zhang, Chunyan Meng, Shengyue Ji, Kangkang Guo
As a potential alternative to conventional antibiotics, the study revealed the biochemical stability of MT-W under simulated in vivo conditions (e.g., under the conditions of specific pH, temperature, and protease enriched). The mean pH of gastric juice, proximal small intestine, terminal ileum, and cecum was 1.0 to 2.5, 6.6, 7.5, and 6.4, respectively,[46] and this pH profile allowed MT-W to exert biological effects in these tissues other than the stomach. There was no significant difference in the antibacterial activity of MT-W and MT against indicator bacteria within the normal temperature range of the organism. The antibacterial activities of MT-W and MT could be maintained above 90%. However, the thermal stability of MT-W was significantly higher than that of MT under conditions between 50 °C and 90 °C (p < 0.05), indicating that it had the advantage of being able to withstand high temperature processing up to 90 °C. Sensitivity to protease degradation was another challenge for MT-W in the treatment of bacterial-mediated gastrointestinal diseases.[47] This study showed that MT-W was significantly better than MT in tolerance to proteases (p < 0.05), which was tested by a variety of bacterial proteolytic and gastrointestinal digestive enzymes (e.g., PE, V8 protease, pepsin, and trypsin), suggesting that the antimicrobial peptide had potential applications in the treatment of gastroenteritis.
Types and site distributions of intestinal injuries in seat belt syndrome
Published in Traffic Injury Prevention, 2020
Yuta Yamamoto, Yusuke Miyagawa, Masato Kitazawa, Shugo Takahata, Seigo Aoyagi, Nao Hondo, Makoto Koyama, Satoshi Nakamura, Shigeo Tokumaru, Futoshi Muranaka, Yuji Soejima
Next, we analyzed the types and locations of the intestinal injuries. Among the 25 patients, there were 64 major bowel (n = 34) and mesenteric (n = 30) injuries for which surgical interventions were performed. Seven patients had a single lesion, while five had double, seven had triple, five had four, and one had six lesions. Regarding the injury sites, the small intestine was divided into the following parts: (1) the ligament of Treitz (100-cm distal from the ligament [proximal jejunum]); (2) the ileocecal valve (100-cm proximal from the valve [distal ileum]); and (3) the intermediate area between those two regions (jejunoileal junction). Regarding perforations, 17 of 20 (85.0%) occurred in the small bowel and 11 (55.0%) in the jejunoileal junction. There were only three perforations (15.0%) of the colon. In contrast, non-perforations occurred across the entire intestine (Figure 1). There were 30 mesenteric injuries: 12 (40.0%) occurred in the jejunoileal junction, 11 (36.6%) in the distal ileum, and two (6.7%) in the proximal jejunum (Figure 2).
Comparative finite element modelling of aneurysm formation and physiologic inflation in the descending aorta
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Serena de Gelidi, Andrea Bucchi
Schulze-Bauer et al. (2002) reported 4 parameters to fit the response of human femoral arteries subjected to inflation tests. In 2003, Schulze-Bauer and Holzapfel (2003) modelled already published clinical data of the thoracic aorta, oblivious of the cross-sectional area, by means of 4 Fung parameters. Sun and Sacks (2005) aimed to produce clear guidelines to build a Fung model in Abaqus. However, they published only 7 parameters. Pandit et al. (2005) published 4 coefficients to fit the experimental data obtained from the inflation tests performed on porcine left anterior descending artery. In 2006, Vande Geest et al. (2006) were unable to fit the experimental data with a 4 parameter Fung elastic model. Differently, Horný et al. (2006) fitted the responses of inflation tests on human thoracic aorta by means of 4 Fung parameters. However, they added a Neo-Hookean term to the SEF. Ma et al. (2007) claimed that their Abaqus model of cerebral aneurysm is modelled by 5 Fung parameters. In 2010, Avril et al. (2010) modelled in Abaqus the inflation of human arteries, publishing only 4 parameters. Vychytil et al. (2010) reported the 9 parameters equation, but they published only 6 coefficients with no assumption for the shear terms. Bellini et al. (2011) reported 4 parameters to fit the responses of planar biaxial tests conducted on the porcine duodenum, the jejunum and the ileum. Recently, Lee et al. (2014) published 7 parameters for porcine carotid arteries.