Mesenteric vessel

Oxamniquine is active against both mature and immature stages of S mansoni but does not appear to be cercaricidal. The mechanism of action is unknown. Contraction and paralysis of the worms results in detachment from terminal venules in the mesentery and transit to the liver, where many die surviving females return to the mesenteric vessels but cease to lay eggs. 

Weichert W, Breddin HK (1987) Effect of naftidrofuryl and dipyridamole on laser-induced thrombosis in rat mesenteric vessels. Vasa 16 377-380... 

Weichert W, Pauliks V, Breddin HK (1983) Laser-induced thrombi in rat mesenteric vessels and antithrombotic drugs. Haemostasis 13 61-71... 

Various modifications are reported with respect to the experimental setup (single pass or recirculated intestinal perfusion) as well as the site of blood collection, e.g. mesenteric vessels for estimation of the intestinal absorption rate (DeGraw RT, Anderson BD 2004). vs. peripheral veins for estimation of systemic availability of the candidate compound. This method is widely used for investigation of intestinal absorption of nutrients by using radioactive tracers (e.g. cholesterol, glucose) and their interference with the candidate compound (Arts et al. 2004). In addition the secretion of the candidate compound into the intestine can be studied by peripheral administration of the compound into a peripheral vein and subsequent determination of the appearance of the candidate compound in the intestinal perfusate (Merino et al. 2003 Berggren et al. 2004). Also variations are reported using chronically isolated intestinal loops in rats (Poelma et al. 1992). 

Over the usual concentration range of physiologically released, circulating epinephrine, B-receptor response (vasodilation) predominates In blood vessels of skeletal muscle and liver a-receptor (vasoconstriction). In blood vessels of other abdominal viscera. The renal and mesenteric vessels also contain specific dopaminergic receptors, activation of which causes dilatation, but their physiological significance has not been established. 

In patients with cirrhosis, CT sometimes demonstrates a mesenteric oedema misty mesentery"). (51) Such a mesenteric, omental and/or retroperitoneal oedema can vary from a moderate infiltrative type to a pronounced oedema compressing the mesenteric vessels. (32)... 

More recent work by Zygmnnt et al. (2002) has shown in rat mesenteric vessels that A -THC and cannabinol canse relaxation via action on sensory nerves bnt that this involves a site of action which is not VRj. From this, they propose that there is a novel eannabinoid receptor or target which may control sensory nerve transmission. 

On CT, a well-defined mass with multiple lobules and septal enhancement after contrast injection may be found. The tumor may encase mesenteric vessels and the inferior vena cava. A complex mass with areas of hyperechogenicity and hypoechogenicity may also be seen. 

An alternative to diffusely constricting the whole mesenteric vessel is to purposefully induce local vasospasm by means of catheter manipulation. This technique was discovered fortuitously in some patients in whom spasm was induced accidentally during... 

Fleischmann D (2003) MDCT of renal and mesenteric vessels. Eur Radiol 13 M94-101... 

Presence of nodes on either side of the mesenteric vessels ( sandwich sign )... 

Except for the duodenal bulb, vdiich is an intra-peritoneal segment, the duodenum is a retroperitoneal structure, partially covered with peritoneum over its anterior aspect, and located within the anterior pararenal space. At this location it bears a close relation with important contiguous viscera such as the pancreatic head, the hepatic flexure, the right kidney, and the gallbladder, as well as with major vascular structures [the inferior vena cava, (IVC), the abdominal aorta, and the superior mesenteric vessels] (Gray 1995). A variety of pathological processes in these structures may have a secondary effect on the duodenum. 

Fig. 9.1. Nonrotation type of intestinal malrotation. CECT at the level of the pancreatic head shows right-sided contrast-filled small bowel loops, left-sided colon, and absence of the horizontal duodenum. Note an abnormal relationship of the superior mesenteric vessels and aplasia of the uncinate process of the pancreas...

Fig. 9.2. Type 11c of intestinal malrotation The horizontal duodenum passes anteriorly to the vertically oriented superior mesenteric vessels with a normally located colon in front of it. (Reprinted with permission from Zissin et al. 1999)...

The characteristic CT findings of intestinal nonrotation include abnormal orientation of the superior mesenteric vessels, aplasia or hypoplasia of the uncinate process of the pancreas, right-sided small bowel loops, a left-sided colon, and the absence of the horizontal part of the duodenum. Vertical or reversed location of the superior mesenteric vessels is, however, not specific for intestinal malrotation. 

Intestinal transplantation represents an alternative in patients with irreversible, chronic intestinal failure in order to restore enteral absorption of ingested food and fluid. In adults the most common cause of chronic intestinal failure results from extensive resection of the small bowel due to occlusion of the superior mesenteric vessels, inflammatory bowel disease, or abdominal trauma. In children the causes of short-... 

Fig. 7.46. Contrast-enhanced MDCT obtained 6 weeks after intestinal transplantation in 39-year-old man with short-bowel syndrome who presented with acute sepsis syndrome. Image shows large ventral abdominal wall defect (between arrows) due to dehiscence and subsequent operative widening of median laparotomy, intra-abdomlnal abscess (asterisk) with air bubbles (white arrowheads) and cutaneous drainage (arrows). Also seen are intestinal graft enlargement due to edematous infiltration, engorgement of mesenteric vessels, and increased contrast enhancement of intestinal wall (black arrowheads), all of which are consistent with surgically proven peritonitis...

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