Jamil A. Matthews

Murine Tissue-Engineered Stomach Demonstrates Epithelial Differentiation

BACKGROUND Gastric cancer remains the second largest cause of cancer-related mortality worldwide. Postgastrectomy morbidity is considerable and quality of life is poor. Tissue-engineered stomach is a potential replacement solution to restore adequate food reservoir and gastric physiology. In this study, we performed a detailed investigation of the development of tissue-engineered stomach in a mouse model, specifically evaluating epithelial differentiation, proliferation, and the presence of putative stem cell markers. MATERIALS AND METHODS Organoid units were isolated from <3 wk-old mouse glandular stomach and seeded onto biodegradable scaffolds. The constructs were implanted into the omentum of adult mice. Implants were harvested at designated time points and analyzed with histology and immunohistochemistry. RESULTS Tissue-engineered stomach grows as an expanding sphere with a simple columnar epithelium organized into gastric glands and an adjacent muscularis. The regenerated gastric epithelium demonstrates differentiation of all four cell types: mucous, enteroendocrine, chief, and parietal cells. Tissue-engineered stomach epithelium proliferates at a rate comparable to native glandular stomach and expresses two putative stem cell markers: DCAMKL-1 and Lgr5. CONCLUSIONS This study demonstrates the successful generation of tissue-engineered stomach in a mouse model for the first time. Regenerated gastric epithelium is able to appropriately proliferate and differentiate. The generation of murine tissue-engineered stomach is a necessary advance as it provides the transgenic tools required to investigate the molecular and cellular mechanisms of this regenerative process. Delineating the mechanism of how tissue-engineered stomach develops in vivo is an important precursor to its use as a human stomach replacement therapy.

VEGF optimizes the formation of tissue-engineered small intestine

AIM To determine the effect of VEGF overexpression on tissue-engineered small intestine (TESI) formation. MATERIALS & METHODS Organoid units were isolated from the intestines of 2-week-old transgenic mouse pups capable of inducible, ubiquitous VEGF overexpression (CMV-Cre/rtTA/tet(0)-VEGF) and implanted into nonobese diabetic/severe combined immunodeficiency mice. Resulting TESI were explanted at 2 and 4 weeks, and studied by histology, tissue ELISA and immunofluorescence. RESULTS At 2 weeks postimplantation, the TESI mucosa from the VEGF overexpression group formed rudimentary villi and more crypts compared with controls, which demonstrated a flat epithelium with few crypts and no villi. At 4 weeks postimplantation, the TESI from the VEGF overexpression group was larger and significantly heavier than controls. Within the mucosa, the villus height and crypt depth was significantly longer, contained a greater percentage of proliferating crypt epithelial cells and consisted of all four terminally differentiated epithelial cell types. There was also a significant increase in the capillary density within the submucosa. CONCLUSIONS Overexpression of VEGF optimizes the formation of TESI by increasing the submucosal capillary density, crypt epithelial proliferation and the rate of mucosa formation. A larger construct with increased villus and crypt height was noted after 4 weeks in vivo.

Perirectal arteriovenous malformation treated by angioembolization and low anterior resection.

We present a case of a child with ongoing lower gastrointestinal bleeding caused by a rectosigmoid arteriovenous malformation. To reduce perioperative bleeding, we performed preoperative angioembolization followed by subsequent resection by low anterior resection. Here we present the case and review the literature regarding neoadjuvent embolization for gastrointestinal and pelvic arteriovenous malformations.

Utilization of Near-infrared Indocyanine Green Angiography for Immediate and Delayed Venous Outflow Assessment in Breast Reconstruction: A Case Report.

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Early abdominal closure using component separation in patients with an open abdomen after trauma: a pilot study

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Open Access Surgery 2015:8 21–26 Open Access Surgery Dovepress

Mastectomy for Female-to-Male Transsexuals: A Two Technique Algorithm

INTRODUCTION: Subcutaneous mastectomy for femaleto-male transsexuals is usually the fi rst operation in gender reassignment with a goal is to create a masculine appearing chest and remove all glandular breast tissue while minimizing scars.1 These patients often have more glandular tissue and signifi cant ptosis compared to traditional subcutaneous mastectomy for gynecomastia. We present the largest series of subcutaneous mastectomies performed in female-to-male transgender patients reported in the literature to date.