Biomedical subjects

Troy M Duininck

Publications and source records attributed to Troy M Duininck.

4 recordsLinked to original sources

PubMed2005

Extrinsic denervation alters postprandial absorption of glucose and glutamine in the ileum: implications for small bowel transplantation.

In the postprandial period, augmentation of absorption of water, electrolytes, and taurocholate is believed to occur in the ileum. The role of extrinsic innervation in this postprandial augmentation has not been well studied and may be an important concept in small bowel transplantation. Our aim was to investigate extrinsic neural mechanisms mediating postprandial absorptive patterns. The study hypothesis was that postprandial augmentation of absorption in the ileum is blunted in transplanted (extrinsically denervated) bowel. Ileal absorption was studied in six dogs with an 80-cm in situ ileal segment via a triple-lumen perfusion technique using an iso-osmolar, ileal-like electrolyte solution alone and containing either glucose 2.5 mM, glutamine 2.5 mM, oleic acid 5 mM, or taurocholate 5 mM. Net absorptive fluxes of each substrate, as well as water and electrolytes, were measured in both the fasted state and after a 400-Kcal mixed meal before and at 2 and 12 weeks after our validated model of complete extrinsic denervation of the jejunoileum. At baseline, there were no differences in absorption of water, electrolytes, or any nutrient postprandially compared with the fasted state. Two weeks after extrinsic denervation, absorption of glucose at both 1 and 2 hours postprandially was decreased compared with absorption during fasting. Glutamine absorption was also decreased at 2 hours postprandially. At 12 weeks after extrinsic denervation, net postprandial absorption of glucose and glutamine returned toward normal and was not different from fasting absorption. No differences were noted in postprandial absorption of oleic acid or taurocholate at any time point. Decreases in absorption of nutrients postprandially after extrinsic denervation (which is necessitated by small bowel transplantation) may play an important role in post-transplant enteric absorptive dysfunction. The previously described postprandial augmentation in net absorption may be a function of enterically isolated gut and does not appear to occur in the in situ ileum.

Animals↗

PubMed2003

Ileal resection enhances jejunal absorptive adaptation for water and electrolytes to extrinsic denervation: implications for segmental small bowel transplantation.

BACKGROUND/PURPOSE: Segmental small bowel transplantation (SBT) may be an alternative to whole jejunoileal SBT. The aim of this study was to evaluate adaptability of extrinsically denervated jejunum after ileectomy. METHODS: Baseline absorption of an isomolar, nonnutrient electrolyte solution was measured in an 80-cm in situ jejunal segment. Control (CON) and extrinsically denervated dogs (EXT DEN) then underwent distal 50% enterectomy; EXT DEN dogs also underwent a complete extrinsic denervation of remnant jejunum. Absorption was remeasured 2 and 12 weeks later; jejunal biopsies at 12 weeks were compared with baseline. RESULTS: All dogs experienced weight loss and diarrhea, which resolved by 10 weeks in CON but persisted in EXT DEN dogs. Net absorptive fluxes of water, Na+, K+, and Cl-, however, remained unchanged in both groups 2 weeks and 12 weeks after denervation. Morphometric evaluation showed an increase in crypt depth in both groups at the 12-week time-point. CONCLUSIONS: Despite a clinical short bowel syndrome, more weight loss, and diarrhea in EXT DEN, there were no temporal differences in net absorptive fluxes of water and electrolytes within or between these 2 groups, and both developed increased crypt depth at 12 weeks. Extrinsic denervation does not blunt jejunal adaptive response to ileectomy.

Adaptation, Physiological↗

PubMedDate not supplied

Small bowel extrinsic denervation does not alter water and electrolyte absorption from the colon in the fasting or early postprandial state.

Small bowel transplantation (SBT) causes watery diarrhea. The decreases shown previously in absorption of water, electrolytes, and bile salts in the jejunum and ileum, although present, are not dramatic and seem not to be great enough to explain the diarrhea. Our aim was to determine changes in water and electrolyte absorption in the colon during fasting and postprandially in a canine preparation of jejunoileal extrinsic denervation, which serves as a model of jejunoileal autotransplantation. We hypothesized that colonic absorption of water and electrolytes decreases transiently in the colon after SBT. Six dogs had cannulas implanted in the colon to study absorption of an ileal-like basal electrolyte solution with or without 10 mmol/L glucose. Absorption during fasting and postprandially was measured before and 2 and 12 weeks after a validated preparation of jejunoileal extrinsic denervation. All dogs developed diarrhea after SBT. Net colonic absorptive fluxes of water and electrolytes in the colon did not change from baseline values at 2 or 12 weeks after extrinsic denervation, either during fasting or postprandially; glucose in the infusate did not alter absorptive fluxes during fasting or postprandially. Extrinsic denervation of the small intestine does not appear to alter colonic absorption of water or electrolytes during fasting or postprandially. These observations suggest that the neurally intact colon has a minimal role in the diarrhea after SBT.

Animals↗

PubMedDate not supplied

de Quervain's thyroiditis: surgical experience.

OBJECTIVE: To review a 35-year experience with management of de Quervain's thyroiditis (dQT), an uncommon inflammatory process of the thyroid gland that is usually treated medically and seldom necessitates surgical intervention. METHODS: A retrospective review was performed of medical records of patients with dQT treated surgically at a single institution between 1966 and 2000. The study group consisted of 11 women and 6 men (mean age, 50 years; range, 23 to 66). All pathology specimens were reviewed. RESULTS: Of the 17 study patients, 14 had surgical treatment before 1980. Typical symptoms of dQT, including pain and tenderness of the thyroid gland, occurred in eight patients, and two had dysphagia from an enlarged thyroid gland. Seven patients were asymptomatic. The indications for operation were a clinically indeterminate thyroid nodule (N = 14), dysphagia (N = 2), and hyperthyroidism with nodular goiter (N = 1). Fine-needle aspiration biopsy (FNAB) was performed in only two patients; biopsy findings were suspicious for a malignant lesion in one patient, and nondiagnostic in the other patient. Thyroid function tests (N = 14) revealed that 12 patients were euthyroid and 2 had hyperthyroidism. Surgical treatment consisted of unilateral lobectomy in 4 patients, near-total thyroidectomy in 12, and total thyroidectomy in 1. Temporary vocal cord palsy and temporary hypocalcemia occurred in one patient each. Fourteen patients (mean follow-up, 204 months) required long-term thyroid replacement therapy. No patient required further thyroid surgical intervention or had further thyroid disease. CONCLUSION: Although surgical intervention is not the primary treatment for dQT, when resection is performed it can be done safely and with low associated morbidity. In the modern era, with routine use of FNAB, fewer patients with this rare entity will require surgical exploration. Patients with atypical features and ones with euthyroidism are more likely candidates than others for surgical intervention.

Adult↗