Cyclic GMP formation of resistance vessel in the development of hypertension in spontaneously hypertensive rats.

We investigated the basal levels and responses of cyclic GMP (cGMP) derived from perfused mesenteric arteries to acetylcholine (ACh) and sodium nitroprusside (SNP) in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) at different ages, in order to evaluate the basal and stimulated release of endothelium-derived relaxing factor (EDRF) from the resistance vessel during the development of hypertension. The mesenteric arteries were removed from 8-, 12- and 20-week-old WKY and SHR, and were perfused with Krebs-Henseleit solution containing 0.2 mM isobutyl methyl xanthine. The effluents from the perfused arteries were corrected before and after infusions of graded doses of ACh or SNP, and the levels of cGMP were measured. The basal levels of cGMP from the mesenteric arteries in the 12- and 20-week-old SHR were significantly lower than those in age-matched WKY. A negative correlation was observed between the basal levels of cGMP and the systolic blood pressure in SHR, but not in WKY, among all ages. On the other hand, there were no differences in the responses of cGMP to infusion of ACh between the WKY and SHR at each age. Moreover, the responsiveness of cGMP to infusion of SNP in the 12-week-old SHR was much higher than that in age-matched WKY. These data suggest that the basal cGMP formation in the arteries which may reflect the basal release of EDRF is reduced in older SHR and is associated with the development of hypertension, and that the stimulated release of EDRF is not associated with the development of hypertension.     

Low doses of endothelin-3 elicit endothelium dependent vasodilation which accompanies with elevation of cyclic GMP.

Low doses (10(-16)-10(-10) M) of endothelin-3 (ET-3) elicited continuous vasodilations of mesenteric arteries preconstricted with norepinephrine (NE) but not with KCl. In arteries perfused with Ca2+ free solution, ET-3 did not affect the perfusion pressure. In endothelium-denuded arteries preconstricted with NE, ET-3 significantly elevated the perfusion pressure in a dose-related manner. The levels of cyclic GMP and cyclic AMP from the intact arteries were significantly elevated by ET-3; the cyclic GMP elevasion disappeared with methylene blue. Following endothelium-denudation, cyclic GMP elevation was abolished, but cyclic AMP elevation was unaffected. Levels of 6-Keto-PGF1 alpha in the arteries were not changed appreciably by ET-3. These data indicate that the vasodilating effects of ET-3 depend on the presence of extracellular Ca2+ and the existence of endothelium. They are accompanied by elevations of cyclic nucleotides and the elevation of cyclic GMP depends on the endothelium. It is possible that the vasodilating effects of low doses of ET-3 are associated with endothelium-derived relaxing factor.     

Neurocognitive and psychiatric disorders-related axonal degeneration in Parkinson's disease

Neurocognitive and psychiatric disorders have significant consequences for quality of life in patients with Parkinson's disease (PD). In the current study, we evaluated microstructural white matter (WM) alterations associated with neurocognitive and psychiatric disorders in PD using neurite orientation dispersion and density imaging (NODDI) and linked independent component analysis (LICA). The indices of NODDI were compared between 20 and 19 patients with PD with and without neurocognitive and psychiatric disorders, respectively, and 25 healthy controls using tract-based spatial statistics and tract-of-interest analyses. LICA was applied to model inter-subject variability across measures. A widespread reduction in axonal density (indexed by intracellular volume fraction [ICVF]) was demonstrated in PD patients with and without neurocognitive and psychiatric disorders, as compared with healthy controls. Compared with patients without neurocognitive and psychiatric disorders, patients with neurocognitive and psychiatric disorders exhibited more extensive (posterior predominant) decreases in axonal density. Using LICA, ICVF demonstrated the highest contribution (59% weight) to the main effects of diagnosis that reflected widespread decreases in axonal density. These findings suggest that axonal loss is a major factor underlying WM pathology related to neurocognitive and psychiatric disorders in PD, whereas patients with neurocognitive and psychiatric disorders had broader axonal pathology, as compared with those without. LICA suggested that the ICVF can be used as a useful biomarker of microstructural changes in the WM related to neurocognitive and psychiatric disorders in PD.     

An alternative procedure for the creation of an ileal conduit in patients undergoing pelvic exenteration: dextrotransmesenteric location

Ileal conduits have long been accepted as a standard method for urinary diversion, but conventional ileal conduits are not always suitable for patients whose ureters are for the greater part compromised by neoplasm or preoperative irradiation, resulting in a shortening of the ureters. Bowel migration into the large cavity, which develops after pelvic organ removal, appears to cause tension on the ureteroileal anastomotic site. Dextrotransmesenteric placement of an ileal conduit may provide easy access to the shortened ureters without exerting pressure on the anastomosis. We employed this procedure in seven patients undergoing pelvic exenteration with relatively minimal morbidity.     

Surgical Resection of Hilar Cholangiocarcinoma: Analysis of Survival and Postoperative Complications

Background Surgery is the only potentially curative treatment for hilar bile duct cancer. This study sought to evaluate the efficacy and feasibility of surgical management of hilar bile duct carcinoma, including radical hepatectomy, at a single institution. Methods We performed a retrospective review of 49 consecutive patients who underwent surgery at our hospital between 1990 and 2003. Results Altogether, 44 of 49 patients underwent radical hepatectomy combined with caudate lobectomy and lymphadenectomy. One and four patients underwent partial hepatectomy or bile duct resection, respectively. No patients underwent preoperative portal vein embolization. The 5-year survival rate was 39.7%, with a median survival time of 3.75 years. The postoperative morbidity and mortality rates were 46.8% and 2.0%, respectively. Cox’s proportional hazard model revealed that lymph node status and the residual tumor factor were independent prognostic factors. Multivariate analysis revealed that preoperative hyperbilirubinemia, postoperative complications, and extended surgical procedures were independently associated with postoperative hyperbilirubinemia. After potentially curative resection, 39.4% of patients suffered from disease recurrence. In 60% of the total cases, the sites of recurrence were distant metastases. Conclusion Surgery, including radical hepatectomy combined with caudate lobectomy and lymph node dissection, is a feasible, effective treatment for hilar bile duct cancer.     

Impact of statin use on the prognosis of patients with hepatocellular carcinoma undergoing liver resection: a subgroup analysis of patients without chronic hepatitis viral infection

Background

Statins have been reported to reduce the risk of hepatocellular carcinoma (HCC). The effect of perioperative statin use on the prognosis of HCC patients undergoing liver resection remains unclear.

Half clamping of the infrahepatic inferior vena cava reduces bleeding during a hepatectomy by decreasing the central venous pressure

Background and aims  Bleeding from the hepatic vein is closely related to central venous pressure (CVP). To evaluate the effect of low central venous pressure during a hepatectomy, the infrahepatic inferior vena cava (IVC) was half clamped. Patients and methods  Between 2006 and 2007, 20 patients undergoing major hepatectomy with the IVC half clamping (half-clamping group) were compared with 58 patients undergoing hepatectomy without IVC half clamping between 2003 and 2005 (control group). The types of liver resection, amount of blood loss during the hepatectomy, volume of blood transfusion, length of hospital stay, and complications were compared between the two groups. Results  In the half-clamping group, blood loss was decreased in comparison to the control group (p = 0.041) and the suprahepatic CVP was low (2.4 ± 1.8 mmHg; p = 0.0002). The diameter at the root of the right hepatic vein was reduced in comparison to before clamping (5.8 ± 1.6 mm; p < 0.001). There were no complications of half clamping on any hemodynamic and blood electrolytic parameters. Conclusion  Using the half clamping technique of the IVC, intra-operative CVP was maintained below 3 mmHg without any side effects, and the low CVP significantly reduced the bleeding from hepatic veins during a major hepatectomy.