GTP Avoidance in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e Requires Tyrosine Kinase Activity, Intracellular Calcium, NOS, and Guanylyl Cyclase

Guanosine 5\u27-triphosphate (GTP) is a chemorepellent in Tetrahymena thermophila that has been shown to stimulate cell division as well as ciliary reversal. Previous studies have proposed that GTP avoidance is linked to a receptor-mediated, calcium-based depolarization. However, the intracellular mechanisms involved in GTP avoidance have not been previously documented. In this study, we examine the hypothesis that GTP signals through a tyrosine kinase pathway in T. thermophila. Using behavioral assays, enzyme immunosorbent assays, Western blotting, and immunofluorescence, we present data that implicate a tyrosine kinase, phospholipase C, intracellular calcium, nitric oxide synthase (NOS) and guanylyl cyclase in GTP signaling. The tyrosine kinase inhibitor genistein eliminates GTP avoidance in Tetrahymena in behavioral assays. Similarly, pharmacological inhibitors of phospholipase C, NOS, and guanylyl cyclase all eliminated Tetrahymena avoidance to GTP. Immunofluorescence data shows evidence of tyrosine kinase activity in the cilia, suggesting that this enzyme activity could be directly involved in ciliary reversal

GTP avoidance in Tetrahymena thermophila requires tyrosine kinase activity, intracellular calcium, NOS, and guanylyl cyclase

Guanosine 5'-triphosphate (GTP) is a chemorepellent in Tetrahymena thermophila that has been shown to stimulate cell division as well as ciliary reversal. Previous studies have proposed that GTP avoidance is linked to a receptor-mediated, calcium-based depolarization. However, the intracellular mechanisms involved in GTP avoidance have not been previously documented. In this study, we examine the hypothesis that GTP signals through a tyrosine kinase pathway in T. thermophila. Using behavioral assays, enzyme immunosorbent assays, Western blotting, and immunofluorescence, we present data that implicate a tyrosine kinase, phospholipase C, intracellular calcium, nitric oxide synthase (NOS) and guanylyl cyclase in GTP signaling. The tyrosine kinase inhibitor genistein eliminates GTP avoidance in Tetrahymena in behavioral assays. Similarly, pharmacological inhibitors of phospholipase C, NOS, and guanylyl cyclase all eliminated Tetrahymena avoidance to GTP. Immunofluorescence data shows evidence of tyrosine kinase activity in the cilia, suggesting that this enzyme activity could be directly involved in ciliary reversal

Internal Hernia After Laparoscopic Antecolic Roux-en-Y Gastric Bypass

BACKGROUND: We evaluated the incidence and presentations of internal hernias (IH) after laparoscopic antecolic Roux-en-Y gastric bypass (RYGB) at our institution. METHODS: We retrospectively reviewed the records of 594 patients who underwent laparoscopic antecolic RYGB at our institution between December 2004 and December 2010. RESULTS: Five hundred ninety-four patients underwent laparoscopic antecolic RYGB with a mean follow-up of 50.5 months. Thirty-six patients developed 37 IH (6.2 %) requiring surgical intervention. Mean age of IH patients was 36.9 years. Thirty-one out of 36 were female. Mean preoperative BMI was 44.3 Kg/m(2). The mean time of presentation after their RYGB was 25.9 months. The mean % excess body weight loss at time of presentation was 54.0 %. Twenty-five out of 37 of IH occurred at Petersen\u27s space; 9/37 IH occurred under the jejunojejunostomy; three patients had hernias at both locations. Mesenteric swirling was the most common CT scan finding in 20/36 (55.6 %). Six out of 36 CT were initially read as normal; however, on retrospective review by a radiologist, abnormalities indicating IH were found in 4/6. Patients presented with different degrees of acuity: 6/37 with chronic abdominal pain and 28/37 with acute abdominal pain. Bowel necrosis was found in 3/37. CONCLUSION: IH is a serious and potentially fatal complication of RYGB. Presentation can vary from chronic abdominal pain to bowel necrosis. CT is helpful in providing diagnosis; however, careful attention to the specific signs of small bowel volvulus, such as mesenteric swirl sign, should be given. IH should be considered in RYGB patients who present with even vague symptoms