Browsing by Subject "Duodenum"

Now showing 1 - 4 of 4
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    Evaluating the Mechanisms of Improved Glucose Homeostasis after Bariatric Surgery in Ossabaw Miniature Swine
    (Hindawi, 2014) Sham, Jonathan G.; Simianu, Vlad V.; Wright, Andrew S.; Stewart, Skye D.; Alloosh, Mouhamad; Sturek, Michael; Cummings, David E.; Flum, David R.; Cellular and Integrative Physiology, School of Medicine
    Background: Roux-en-Y gastric bypass (RYGB) is the most common bariatric operation; however, the mechanism underlying the profound weight-independent effects on glucose homeostasis remains unclear. Large animal models of naturally occurring insulin resistance (IR), which have been lacking, would provide opportunities to elucidate such mechanisms. Ossabaw miniature swine naturally exhibit many features that may be useful in evaluating the anti diabetic effects of bariatric surgery. Methods: Glucose homeostasis was studied in 53 Ossabaw swine. Thirty-two received an obesogenic diet and were randomized to RYGB, gastrojejunostomy (GJ), gastrojejunostomy with duodenal exclusion (GJD), or Sham operations. Intravenous glucose tolerance tests and standardized meal tolerance tests were performed prior to, 1, 2, and 8 weeks after surgery and at a single time-point for regular diet control pigs. Results: High-calorie-fed Ossabaws weighed more and had greater IR than regular diet controls, though only 70% developed IR. All operations caused weight-loss-independent improvement in IR, though only in pigs with high baseline IR. Only RYGB induced weight loss and decreased IR in the majority of pigs, as well as increasing AUCinsulin/AUCglucose. Conclusions: Similar to humans, Ossabaw swine exhibit both obesity-dependent and obesity-independent IR. RYGB promoted weight loss, IR improvement, and increased AUCinsulin/AUCglucose, compared to the smaller changes following GJ and GJD, suggesting a combination of upper and lower gut mechanisms in improving glucose homeostasis.
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    Influence of Peri-duodenal Non-constrictive Cuff on the Body Weight of Rats
    (Springer US, 2015-02) Lu, Xiao; Mattar, Samer G.; Kassab, Ghassan S.; Department of Biomedical Engineering, School of Engineering and Technology
    Background Weight loss has been found to improve or re- solve cardiovascular comorbidities. There is a significant need for reversible device approaches to weight loss. Methods Non-constrictive cuff (NCC) is made of implantable silicone rubber with an internal diameter greater than the duodenum. Ten or 11 NCC were individually mounted along the duodenum from the pyloric sphincter toward the distal duodenum to cover ~22 mm in the length. Twelve Wistar rats were implanted with NCC, and six served as sham, and both groups were observed over 4 months. Six rats with implant had their NCC removed and were observed for additional 4weeks. Results The food intake decreased from 40.1 to 28.1 g/day after 4 months of NCC implant. The body weight gain decreased from 1.76 to 0.46 g/day after 4 months of NCC implant. The fasting glucose decreased from 87.7 to 75.3 mg/ dl at terminal day. The duodenal muscle layer covered by the NCC increased from 0.133 to 0.334 mm. After 4 weeks of NCC removal, the food intake, body weight gain, and fasting glucose recovered to 36.2, 2.51 g/day, and 83.9 mg/dl. The duodenal muscle layer covered by the NCC decreased to 0.217 mm. Conclusion The NCC implant placed on the proximal duode- num is safe in rats for a 4-month period. The efficacy of the NCC implant is significant for decrease in food intake, body weight gain, and fasting glucose in a normal rat model. The removal of NCC implant confirmed a cause-effect relation with food intake and hence body weight.
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    Primary lung sarcoma with gastric metastasis and morphological divergence presenting as melena
    (BMJ, 2021-08-12) Eiswerth, Michael J.; Pinter, Alexander; Reynolds, Samuel Benjamin; Guardiola, John; Medicine, School of Medicine
    A 61-year-old man was admitted to the medical intensive care unit following a 2-week history of weakness, lightheadedness and melena resulting in an acute anaemia. Upper endoscopy revealed multiple large gastric masses without evidence of active bleeding. CT of the chest revealed a large right upper lobe mass with bony destruction of the third rib and invasion into the anterior chest wall and mediastinum, as well as a soft-tissue density in the left kidney. Biopsy and histopathological review of both pulmonary and gastric masses revealed two distinct sarcomatous malignancies that, while both from a primary lung source, differed in their morphology. Natural history and behaviour are not well understood in sarcomas due to their rarity, but abdominal metastasis is considered an uncommon event in the progression of the disease. Gastrointestinal bleeding as the presenting symptom of a primary lung sarcoma is an atypical finding with no previously reported cases.
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    Relationships of Intestinal Lactase and the Small Intestinal Microbiome with Symptoms of Lactose Intolerance and Intake in Adults
    (Springer, 2022) Jansson-Knodell, Claire L.; Krajicek, Edward J.; Ramakrishnan, Monica; Rogers, Nicholas A.; Siwiec, Robert; Bohm, Matt; Nowak, Thomas; Wo, John; Lockett, Carolyn; Xu, Huiping; Savaiano, Dennis A.; Shin, Andrea; Medicine, School of Medicine
    Background: Approximately two-thirds of adults are genetically predisposed to decreased lactase activity after weaning, putting them at risk of lactose intolerance. However, symptoms are a poor marker of lactose maldigestion. Aims: We assessed association between self-reported lactose intolerance and intestinal lactase, lactose intake, and the small intestinal microbiome. Methods: Patients 18-75 years presenting for upper endoscopy were recruited prospectively. Observational study participants completed a lactose intolerance symptom questionnaire and reported lactose intake. Post-bulbar biopsies were obtained to measure lactase activity and assess the small intestinal mucosal microbiome. We compared intestinal lactase between patients with and without lactose intolerance. We assessed associations between lactose intolerance symptoms and lactase and lactose intake. We examined associations of small bowel microbial composition with self-reported lactose intolerance and symptoms. Results: Among 34 patients, 23 (68%) reported lactose intolerance. Those with lactose intolerance had higher total symptom scores, more frequent bowel urgency, and more bowel movements after consuming dairy. The proportion of individuals with abnormal lactase activity did not differ by lactose intolerance status. Median lactase levels were correlated with total lactose intolerance symptom scores (p = 0.038) and frequency of bowel urgency (p = 0.012). Daily lactose intake did not differ between groups. In 19 patients, we observed significant associations of small intestinal microbiome beta diversity with stool consistency after consuming dairy (p = 0.03). Conclusions: Intestinal lactase is associated with lactose intolerance symptoms and bowel urgency in adults but does not distinguish the clinical phenotype entirely. Studying other contributing factors (microbiota, diet) may further clarify the pathophysiology of lactose intolerance.