Dobutamine Versus Vasopressin After Mesenteric Ischemia.

BACKGROUND: Gastrointestinal blood flow may be compromised during and after vasopressor support. Endothelin expression may lead to microcirculatory dysfunction. The aim of this study was to analyze the effect of vasopressin and dobutamine after mesenteric ischemia on the gastrointestinal mucosal microcirculation, endothelin expression, and morphologic injury. MATERIALS AND METHODS: Pigs were studied in four groups (six pigs in each group): 1, sham; 2-4 ischemia (1 h superior mesenteric artery occlusion with 30 min reperfusion and 30 min of vehicle [2], dobutamine [3], or vasopressin [4] administration, followed by 30-min break and thiopental-induced hypotension [3, 4]). Blood flow of the gastric, jejunal, and rectosigmoidal mucosa was measured. At the end of the experiment, the mucosal expression of endothelin-1 (ET-1) and its receptor subtypes A (ETA) and B were determined by polymerase chain reaction. Mucosal injury, apoptotic cell death, and leukocytic infiltration were determined by histology and immunohistochemical analysis of cleaved caspase-3 and myeloperoxidase. RESULTS: Mesenteric ischemia increased jejunal mucosal ET-1 gene expression, arterial ET-1, intestinal fatty acid binding protein, and jejunal mucosal injury compared with sham. Dobutamine increased arteriovenous shunting at the cost of the jejunal mucosal blood perfusion. This was associated with an increased expression of ET-1 and ETA and mucosal leukocytic infiltration. In contrast, vasopressin increased postischemic capillary density and tissue blood flow. This was associated with a lower ET-1 gene expression. Vasopressin did not induce jejunal mucosal leukocytic infiltration. CONCLUSIONS: Vasopressin reduces mesenteric ischemia-associated alterations of the microcirculation and tissue integrity, whereas dobutamine does not.

Vasopressin aggravates cardiopulmonary bypass-induced gastric mucosal ischemia.

BACKGROUND/AIM: Upper gastrointestinal bleeding (UGIB) is one of the most frequent gastrointestinal complications after cardiac surgery with cardiopulmonary bypass (CPB). Endothelin expression and microcirculatory dysfunction have been shown to be involved in UGIB. The aim of this study was to analyze the effect of vasopressin during CPB on the gastric mucosal microcirculation and the involvement of the endothelin system. METHODS: Eighteen pigs were randomized into three groups (n = 6 each): group I = sham, group II = CPB (1-hour CPB) and group III = CPB + vasopressin (1-hour CPB and vasopressin administration during CPB to maintain baseline arterial pressure). All animals were observed for a further 90 min after termination of CPB. Systemic hemodynamics as well as blood flow and oxygen saturation of the gastric mucosa were measured continuously. At the end of the experiment, the gastric mucosal expressions of endothelin-1 (ET-1) and its receptor subtypes A (ET(A)) and B (ET(B)) were determined by polymerase chain reaction. Gastric mucosal injury, apoptotic cell death and leukocytic infiltration were determined by histology and immunohistochemical analyses of cleaved caspase-3 and myeloperoxidase. RESULTS: CPB decreased gastric microvascular perfusion, which was associated with an increased expression of ET-1 and ET(A). Vasopressin aggravated the CPB-associated malperfusion, whereas it completely abrogated the upregulation of ET-1 and ET(A). Interestingly, vasopressin did not induce gastric mucosal morphologic injury, leukocytic infiltration or apoptotic cell death. CONCLUSION: Vasopressin aggravates CPB-associated microvascular malperfusion of the gastric mucosa but does not induce gastric mucosal injury.

Sensing the sending of SMS messages: an automated test.

OBJECTIVE: The aim of this study was to carry out automated experiments to test for telepathy in connection with text messages. METHOD: Subjects, aged from 11 to 72, registered online with the names and mobile telephone numbers of three senders. A computer selected a sender at random and asked him/her to send a short message service (SMS) message to the subject via the computer. The computer then asked the subject to guess the sender's name and delivered the message after receiving the guess. A test consisted of nine trials. The effects of subjects' sex and age and the effects of delay on guesses were evaluated. The main outcome measure was the proportion of correct guesses of the sender's name, compared with the 33.3% mean chance expectation. RESULTS: In 886 trials, there were 336 hits (37.9%), significantly above the 33.3% chance level (P = .001). The hit rate in incomplete tests was 38.4% (P = .03), showing that optional stopping could not explain the positive results. Most tests were unsupervised, which left open the possibility of cheating, but high-scoring subjects were retested under filmed conditions, where no cheating was detected, with 19 hits in 43 trials (44.2%; P = 0.09).