Can gallbladder polyps predict colorectal adenoma or even neoplasia? A systematic review.

OBJECTIVE: The purpose of the present systematic review is to identify whether an association between gallbladder polyps and colorectal adenoma or neoplasia exists. DATA SOURCES: We conducted a systematic review searching the Medline (1966-2016), Scopus (2004-2016), ClinicalTrials.gov (2008-2016) and Cochrane Central Register of Controlled Trials CENTRAL (1999-2016) databases together with reference lists from included studies. STUDY ELIGIBILITY CRITERIA: All prospective and retrospective observational cohort studies were included. RESULTS: Four studies were finally included which included 17,437 patients. The association between gallbladder polyps and colorectal adenoma or even neoplasia is not unanimously supported. However, a possible association is clearly depicted. According to one study it seems that this correlation seems to become significant only when the gallbladder polyps exceed the size of 5 mm. However, the impact of size of gallbladder polyps was not investigated in the remaining studies. CONCLUSION: According to the results of our systematic review there is some evidence to support the hypothesis that gallbladder polyps might adequately predict future risk of colorectal neoplasia. At present, however, current knowledge is very limited and the available data scarce. In this context further studies are necessary to be carried out, before the presence of gallbladder polyps on ultrasound can be recommended as an indication to perform a screening colonoscopy on the same patient.

Demonstration of functional neuronal beta3-adrenoceptors within the enteric nervous system.

BACKGROUND & AIMS: Although the beta(3)-adrenoceptor (AR) has been suggested to be involved in regulation of gut motility and visceral algesia, the precise mechanisms have been unknown. beta(3)-AR has been postulated to have a nonneuronal expression, being initially characterized in adipocytes and subsequently in the smooth muscle. We aimed to investigate the expression of beta(3)-AR in human enteric nervous system and its role in motility and visceral algesia. METHODS: The expression of beta(3)-AR in human colon myenteric and submucosal plexus was investigated using immunohistochemistry. The effects of a beta(3)-AR agonist on nerve-evoked and carbachol-induced contractions as well as somatostatin release were investigated in strips of human colon. The effect of an agonist on diarrhea and visceral pain was investigated in vivo in rat models. RESULTS: beta(3)-AR is expressed in cholinergic neurons in the myenteric plexus and submucosal plexus of human colon. Activation of beta(3)-AR causes the release of somatostatin from human isolated colon. In a rat model of visceral pain, beta(3)-AR agonist elicits somatostatin-dependent visceral analgesia. beta(3)-AR agonists inhibit cholinergically mediated muscle contraction of the human colon, as well as chemically induced diarrhea in vivo in a rat model. CONCLUSIONS: This is the first demonstration of expression of beta(3)-AR in the enteric nervous system. Activation of these receptors results in inhibition of cholinergic contractions and enhanced release of somatostatin, which may lead to visceral analgesia and inhibition of diarrhea. Therefore, beta(3)-AR could be a novel therapeutic target for functional gastrointestinal disorders.