The small intestine generally transports dietary fats to circulation in triglyceride (TG)-rich lipoproteins. The two main intestinal lipoproteins are chylomicron (CM) and very low-density lipoprotein (VLDL). Unfortunately, studies on the CM biogenesis and intestinal transport of dietary fats have been hampered by the lack of an adequate in vitro model. In this study, we investigated the possible factors that might increase the efficiency of CM production by Caco-2 cells. We utilized sequential NaCl gradient ultracentrifugation to isolate the CMs that were secreted by the Caco-2 cells. To confirm the successful isolation of the CMs, we performed Fat Red 7B staining, TG reading, apolipoprotein B (ApoB) measurement, and transmission electron microcopy (TEM) analysis. We then tested the effects of cell differentiation, oleic acid, mono-olein, egg lecithin, incubation time, and collagen matrix on CM secretion. We found that cell differentiation, oleic acid, and lecithin were critical for CM secretion. Using the Transwell system, we further confirmed that the CMs produced by our Caco-2 cells contained significant amount of TGs and ApoB-48 such that they could be detected without the use of isotope labeling. In conclusion, when fully differentiated Caco-2 were challenged with oleic acid, lecithin, and sodium taurocholate, 21% of their total number of lipoproteins were CMs with the diameter of 80-200 nm.

No description available.

Background Endoscopic ultrasound-guided fine-needle aspiration and biopsy (EUS-FNA/FNB) has been traditionally used for making a tissue diagnosis. Several newer techniques are emerging as a viable alternative to EUS-FNA/FNB, including mucosal incision-assisted biopsy (MIAB), with a view to increasing the diagnostic yield for upper gastrointestinal (GI) subepithelial tumors (SETs). We conducted a systematic review and meta-analysis to describe the overall diagnostic yield of MIAB for upper GI SETs. Methods Multiple electronic databases (MEDLINE, EMBASE and Google Scholar) and conference abstracts were comprehensively searched. The primary outcome of our meta-analysis was the overall diagnostic yield of the MIAB. The secondary outcome was to study complications in terms of perforation and clinically significant bleeding. The meta-analysis was performed using a DerSimonian and Laird random-effect model. Results Seven studies were included in the final meta-analysis, reporting a total of 159 patients (male 86, female 73) with a mean age of 58 years. The overall pooled diagnostic yield of MIAB was 89% (95% confidence interval [CI] 82.65-93.51, I2=0.00). Histologically, GI stromal tumor was the reported diagnosis in 38.62% (95%CI 22.29-56.24, I2=77.51%) of tumors, followed by leiomyoma 25% (95%CI 18.02-32.62, I2=4.42%). The overall rate of clinically significant bleeding following the procedure was 5.03% (95%CI 0.36-12.86, I2=57.43%) and no perforations were reported. Conclusions MIAB is a safe and effective technique for the diagnosis of upper GI SETs and can be considered as a viable alternative to EUS-FNA/FNB. MIAB can be performed during routine endoscopy and no advanced equipment is required.

Introduction: Gastrointestinal stromal tumours (GIST) are the commonest tumour of mesenchymal origin; favour the stomach, and account for a very small percentage of gastrointestinal tract tumours. Methods: In this retrospective audit of GISTs presenting to the Groote Schuur Hospital surgical and oncological multidisciplinary team (MDT) between 2004 – 2019, gastric GISTs were evaluated as regards presentation, gastric anatomical position, histological subtype with risk stratification, management and outcomes. Results: Of 126 GIST tumours presenting to this MDT, 82 originated in the stomach. Complete histopathological records could be obtained for 64. With an average of 59 years (50 male: 32 female), 18 (28%) presented with a herald bleed. Other common presentations included anaemia, epigastric mass and pain. The tumours were predominantly found in the body and fundus (64%), with a spindle cell subtype predominance (41%). The association between cancer cell subtype and gastric position was not significantly different (p=0.728). Cystic degeneration was found on 11 (17%) analyzed and cell necrosis on 12 (18%). These findings were not related to larger tumor size or prognosis. Five required downstaging with Imatinib prior to surgery. Thirty-seven patients underwent a surgical procedure: 24 wedge resections and 12 anatomical resections. Risk stratification was performed with the modified National Institutes of Health (NIH/Fletcher) score. Twenty-eight cases had inaccurate mitotic counts and couldn't be scored, 17 scored high risk, 9 intermediate risk, 9 low risk and 1 very low risk. Ten patients died of metastatic disease, 34 were discharged with no disease progression after 3 years, 1 patient with disease progression currently remains on Imatinib, and 19 were lost to follow up. Conclusion: Gastric GISTs appear to have a predilection for the proximal stomach; it is unsure whether this is purely due the greater surface area. The spindle cell subtype dominated in the proximal gastric GISTs. Cystic degeneration and cell necrosis did not seem to be related to larger tumours or outcomes.

The simultaneous effects of dietary fiber, temperature, and daylength on the gastrointestinal morphology and physiology in meadow voles (Microtus pennsylvanicus) were investigated. Voles were randomly divided (10 in each group) and placed in 15-day treatment regimes [cold (5 C) and warm (21 C), daylengths long (18L:6D) and short (6L:18D), and diets of high fiber (50% neutral detergent fiber [NDF]) and low fiber (5% NDF) content] followed by a 5-day digestibility trial to determine diet digestibility in relation to food intake. Total mass of individuals, length, wet mass and dry mass of the stomach, small intestine, caecum, large intestine, adrenal glands, liver, and kidneys was evaluated. Data was analyzed by ANOVA using the SAS system. Meadow voles increased food intake but decreased turnover time and digestive efficiency under low ambient temperature condition, short daylength, and/or high dietary fiber. Increased energy demand had a minimal effect on the gastrointestinal tissue mass but resulted in slightly increased length of all tissues except the small intestine. The increased food intake and small changes to gastrointestinal morphology during times of increased energy demands suggest that meadow voles are able to meet their energy needs primarily through increased food intake, and therefore more energetically expensive gastrointestinal changes are minimized. / Master of Science

A study was performed to identify apoptotic cells in the equine intestine and to determine if the occurrence of apoptosis is affected by gastrointestinal disease and tissue layer of intestine. Samples of intestine were collected from 38 horses that underwent surgery or were humanely destroyed for small or large bowel obstruction, strangulation or distension. Samples were also taken from 9 horses which were humanely euthanized for reasons other than gastrointestinal disease or systemic disease. Specimens were collected at surgery from intestine involved in the primary lesion, distant to the primary lesion, or at necropsy from several sites including the primary lesion. Tissues were fixed, serially sectioned and stained with hematoxylin and eosin (H&E) and for apoptosis by the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) technique. The number of apoptotic cells per high power field were counted in the mucosa, circular muscle, longitudinal muscle and serosa for each sample of intestine. Apoptotic staining nuclei were seen in all layers of intestine. An increased number of apoptotic cells were found in the circular muscle of the intestine from horses with simple obstruction. Intestine distant from the primary strangulating lesion had higher numbers of apoptotic cells than intestine distant from a simple obstruction lesion or intestine taken at the site of a strangulating or simple obstructive lesion. Intestine from horses with obstructing or strangulating lesions in the small intestine and large colon has increased numbers of apoptotic cells. Further investigation is required to determine whether increased apoptosis affects intestinal function. / Master of Science

Thesis (M.Sc.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 118-127.

Thesis (Ph. D.)--University of New South Wales, 2004. / Title from PDF title page (viewed on Mar. 25, 2006). Includes bibliographical references (p. 264-286).

Wang, Hui Chuan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 184-202). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Syndromic craniosynostosis is most commonly associated with mutations in Fibroblast Growth Factor Receptor genes (FGFR)-1, 2 and 3. Clinical and animal reports suggest a link between FGFR-associated craniosynostosis and defects in the gastrointestinal tract (GIT). Objective: to determine whether GIT malformations occur more frequently in the craniosynostosis population with a known FGFR mutation when compared to the general population. Methods: A retrospective chart review of patients diagnosed with Crouzon, Pfeiffer or Apert syndromes between 1990 and 2011 was performed at the Hospital for Sick Children in Toronto. Thirty-two charts meeting inclusion criteria were analyzed for any history of GIT abnormalities. Results: Three out of 32 patients had documented intestinal/bowel malrotations while 7 had gastroesophageal reflux disease. All patients had documented FGFR2 mutations, a finding in line with previous studies and published case reports. Conclusions: Results suggest an association between FGFR-associated craniosynostosis and GIT malformations.