The aim was to investigate the action of serotonin (5HT) on function of the ileocolonic junction (ICJ) in vivo. In anaesthetised rats, models were developed to study the effects of intra-aortic (ia) serotonin on ileocolonic and colonic transit, and the effects on transit of a number of 5HT receptor antagonists. In the first series of experiments, a bolus of saline labelled with 99mTc DTPA was instilled 20 cm proximal to the ICJ and transit was assessed three hours later by the geometric centre of the spread of isotope. In the second series, similar techniques were used on the postcaecal colon and transit assessed two hours later. In the third series of experiments, the effects of ia 5HT on ileal net fluid flux was evaluated by standard perfusion experiments with 14C polyethylene glycol (PEG) 4000 as a non-absorbable marker in rat plasma-like electrolyte solution. Compared with ia saline, 5HT accelerated ICJ transit significantly (p<005). This acceleration was comparable with the effect of ia bethanechol. The effects of 5HT on ICJ transit were inhibited by the intraperitoneal (ip) infusion ofatropine, the 5HT receptor antagonists, methysergide, ketanserin, zacopride, and the 5HT4 agonist, SC53116. Methysergide, zacopride, and SC53116 given with ia 5HT slowed ICJ transit to rates below those of ia saline alone. When these same agents were given together with ia saline, the ICJ transit was not significantly altered. Serotonin, at the dose that accelerated ICJ transit, did not significantly alter colonic transit or ileal fluid transport. In conclusion, 5HT is a potent pharmacological stimulant oftransit across the rat ICJ in vivo; the action of 5HT is mediated partly through muscarinic neurones and several 5HT receptor subtypes.

Chyle is a fluid rich in triglycerides and is characterized by the presence of chylomicrons. Chylous effusions are unusual complications of malignant neoplasms, usually lymphomas. The combination of chyloperitoneum and chylothorax is very rare. When abdominal lymphatics are obstructed, chylous ascites results and eventually leads to a chylothorax. We present the case of a 68-year-old woman with a chyloperitoneum and a right-sided chylothorax due to an underlying malignant B-cell lymphoma. After thoracocentesis and replacement therapy with medium chain triglycerides, she was treated with a combination of cyclophosphamide, vincristine and prednisone. This has resulted in a regression of the chylous effusions. A short review of the literature describes causes, diagnosis and therapy of chylous effusions.

Campylobacter jejuni and Salmonella spp are the most frequently cultured micro-organisms in infectious gastroenteritis among patients hospitalized at the departments of gastroenterology and geriatrics. As a whole, the hospitalized patient population with Campylobacter gastroenteritis is a younger one, compared to the Salmonella-infected group. Both pathogens can be associated with a biochemical pancreatitis, which is usually without clinical importance. However, serious complications can occur, with a predominance of visceritis for C. jejuni, and renal function impairment for Salmonella spp. Finally, an asymptomatic carrier state is well known in the Salmonella infection spectrum, whereas C. jejuni might cause a recurrent disease in some patients.

1. The role of nitric oxide (NO) in non-adrenergic non-cholinergic (NANC) neurotransmission was studied on circular muscle strips of the canine lower oesophageal sphincter (LOS). Electrical field stimulation evoked frequency-dependent relaxations, which were resistant to adrenergic and cholinergic blockade and abolished by tetrodotoxin. 2. Exogenous administration of NO induced concentration-dependent and tetrodotoxin-resistant relaxations which mimicked those in response to electrical stimulation. 3. NG-nitro-L-arginine (L-NNA), a stereospecific inhibitor of NO-biosynthesis, inhibited the relaxations induced by electrical stimulation but not those by exogenous NO or vasoactive intestinal polypeptide (VIP). 4. The effect of L-NNA was prevented by L-arginine, the precursor of the NO biosynthesis but not by its enantiomer D-arginine. 5. Haemoglobin abolished the NO-induced responses and reduced those evoked by electrical stimulation. 6. Cumulative administration of VIP induced concentration-dependent relaxations, which were slow in onset and sustained. A complete relaxation to VIP was not achieved and the relaxations were not affected by L-NNA. 7. In conclusion, our results provide evidence that NANC relaxations are mediated by NO, suggesting NO or a NO releasing substance as the final inhibitory NANC neurotransmitter in the canine LOS.

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