Background: Remifentanil preconditioning (RPC) reduces the infarct size in anesthetized rat hearts, and this effect seems to be mediated by all three types of opioid receptors (ORs). Because there is evidence of only [kappa]- and [delta]- but not [mu]-ORs in the rat heart, the authors investigated whether RPC confers cardioprotection via cardiac [kappa]- and [delta]-OR as well as via extracardiac [mu]-OR agonist activity. The authors also investigated the involvement of signaling mechanisms, namely protein kinase C and mitochondrial adenosine triphosphate-sensitive potassium (KATP) channels.
Methods: The hearts of male Sprague-Dawley rats weighing 190-210 g were removed, mounted on a Langendorff apparatus, and perfused retrogradely at 100 cm H2O with Krebs-Ringer's solution. All hearts were subjected to 30 min of ischemia and 2 h of reperfusion. The study consisted of three series of experiments on the effect of ischemic preconditioning or RPC (10, 50, and 100 ng/ml remifentanil) after blockade of OR subtypes ([delta]-OR antagonist naltrindol, [kappa]-OR antagonist nor-binaltorphimine, and [mu]-OR antagonist CTOP). The involvement of protein kinase C or the KATP channel in the cardioprotection of RPC was also investigated using specific blockers in each group. RPC was produced by three cycles of 5-min perfusion of remifentanil in Krebs-Ringer's solution interspersed with a 5-min reperfusion with Krebs solution only. Infarct size, as a percentage of the area at risk, was determined by 2,3,5-triphenyltetrazolium staining.
Results: Infarct size as a percentage of the area at risk was significantly reduced after RPC from 51.9 +/- 5.0% (control, n = 8) to 36.2 +/- 10.0% (100 ng/ml RPC, n = 8, P < 0.01). This effect was stopped by pretreatment with naltrindol (52.3 +/- 5.2%) and nor-binaltorphimine (43.5 +/- 6.0%) but not CTOP (37.1 +/- 6.0%). Chelerythrine and GF109203X, both protein kinase C inhibitors, abolished the effects of RPC or ischemic preconditioning on infarct size as a percentage of area at risk. 5-Hydroxydecanoate (a selective mitochondrial KATP channel blocker) also abolished the cardioprotection of RPC and IPC, but HMR-1098 (a selective inhibitor of the sarcolemmal KATP channel) did not. 相似文献
Between 1983 and 1987 repeat transurethral resection (TUR) was performed in 20 patients with a diagnosis of stage A1 prostatic carcinoma. The average weight of the resected tissue in the repeat TUR was 8.81 g (range 3-20 g). In 5 of 20 cases (25%) residual prostatic cancer was identified. By adding the number of foci with cancer obtained at the initial operation with the repeat TUR, 16 cases (80%) remained as A1 and 4 cases (20%) were reclassified (upstaged) to A2. The usefulness of this technique in the restaging of patients with incidental carcinoma of the prostate is analyzed. 相似文献
Several authors have shown that CN participates in the acquisition of motor conditioned responses (MCR), probably as the integrating structure. Most of CN's efferent fibers in the cat end in the entopeduncular nucleus (EPN), therefore the command for the motor pattern could be exerted through EPN, representing part of the efferent link of the neuronal circuitry involved in MCR. Thirty-two cats were trained to avoid actively an electrical stimulus when a series of flashes appeared, and to press a lever to obtain 0.5 ml of milk. After the cats reached the learning criterion for both responses, electrolytic lesions of the entopeduncular nucleus or internal capsule (IC) were made bilaterally. When the cats recovered their normal motor behavior, the conditioned sessions were resumed once a day, for 45-50 days. Both learning responses disappeared (p less than 0.01) in those animals with the largest EPN lesions. In contrast, for small EPN lesions, learned responses were absent only during the first 3 or 4 sessions, and then the level of responses increased each day. However, it never reached that of sham lesioned cats. On the other hand, IC lesioned cats showed no statistical differences with respect to sham lesioned animals. These data support the participation of EPN in the motor circuitry responsible for MCR. 相似文献
Zusammenfassung Einleitend werden die Indikationen, technische Prinzipien sowie spezielle Postulate für die resezierende Crohn-Chirurgie angeführt. In Operationsszenen werden dann Resektionsgrenzen, Techniken der Skeletierung und Anastomose, Fistelversorgung, Netzplastik, Ureterolyse und schliesslich an einem Beispiel von Duodenal-Befall die Strikturoplastik demonstriert. Abschliessend werden an Hand graphischer Übersichten die Operationsindikationen, Arten der Eingriffe und Komplikationen bei 272 Patienten dargelegt, die im Zeitraum 10/81–12/86 operiert wurden. 相似文献
Epidemiologic studies of Seventh-Day Adventists have clearly shown that dietary habits are associated with risk of coronary heart disease (CHD) and other chronic diseases. However, a few surprising results emerge. Meat consumption is clearly hazardous for Adventist men by raising CHD mortality. However, no such effect was seen in women. Possible reasons are discussed. Our data, and that of others, strongly support the role of a fatty food, specifically nuts, as protective for CHD. The possible implications of this result for fat intake as a risk factor for CHD are discussed. In particular, it may be that consumption of modest quantities of certain fats is beneficial, rather than hazardous. The lower risk of CHD in Adventists probably has a complicated explanation and certainly cannot be entirely explained by their nonsmoking status or a superior serum lipid profile. Adventists are unique in that the majority of this group have adopted a dietary habit that is either vegetarian or tending in this direction. The power of incorporating health into a system of religious belief is discussed. Possibly others can also implement such a model to their advantage. 相似文献