Role of C-type natriuretic peptide receptor and large-conductance calcium-activated potassium channels in brain natriuretic peptide-induced porcine coronary artery dilation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the role of C-type natriuretic peptide receptor (NPR-C) and large-conductance calcium-activated potassium channels (BK(Ca)) in brain natriuretic peptide (BNP) induced porcine coronary artery dilation.</p><p><b>METHODS</b>Porcine coronary artery rings were obtained and treated with BNP (10(-6) mol/L), BNP + NPR-C antagonist cANF4-28 (10(-6) mol/L) and BNP + BK(Ca) blocker tetraethylammonium (TEA, 1 mmol/L). The vascular tone experiments were observed on 10 vessel segments. BK(Ca) current density was measured by the whole-cell patch clamp technique.</p><p><b>RESULTS</b>The maximum diastolic rate was similar between BNP group (68.51% ± 11.50%) and cANF4-28 + BNP group (65.67% ± 11.90%, P > 0.05) while significantly reduced in TEA + BNP group (28.87% ± 4.55%, all P < 0.05). When the holding potential was set at +60 mV, the BK(Ca) current density of BNP group was (78.48 ± 5.86) pA/pF, which was significantly higher than control group [(53.84 ± 4.55) pA/pF, P < 0.05], which was equally reduced in the TEA group and TEA + BNP group [(28.80 ± 2.76) pA/pF and (30.60 ± 3.88) pA/pF respectively, all P < 0.05 vs. control group].</p><p><b>CONCLUSION</b>BNP could relax the porcine coronary arterial smooth muscles by increasing BK(Ca) current, and this effect is not mediated by NPR-C.</p>

Sodium channel changes in human atrial cells isolated from various ages / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate if the increased incidence of atrial fibrillation with age was associated with changes of Na(+) channel in atrial myocytes.</p><p><b>METHODS</b>Twenty-three patients underwent valve replacement operations were divided into adult [< 60 years, n = 15, 9 males, mean age (42.1 +/- 7.1) years] and aged group [> or = 60 years, n = 8, 5 males, mean age (63.3 +/- 3.1) years]. All patients were in normal sinus rhythm. Whole cell patch clamp techniques were used to record the Na(+) currents (I(Na)) of right auricle myocytes.</p><p><b>RESULTS</b>Both current density and time-dependent recovery of I(Na) were similar in the cells from the 2 groups. Voltage-dependent inactivation of I(Na) of myocytes in the aged atria was shifted to more positive voltages.</p><p><b>CONCLUSION</b>Current density of I(Na) was similar between the 2 age groups, and Na(+) channel might not be an important determinant for the increased incidence of atrial fibrillation in aged patients.</p>

Early diagnosis of pancreatic cancer is essential to improving the effect of treatment / 中华外科杂志

<p><b>OBJECTIVES</b>To explore the relation between tumor TNM of pancreatic cancer and treatment, and to summarize the experience in diagnosis and treatment of pancreatic cancer.</p><p><b>METHODS</b>The data on 321 patients with pancreatic cancer treated at our hospital between January 1990 and December 2000 were reviewed retrospectively. Radical resection and survival for various TNM stages were analyzed.</p><p><b>RESULTS</b>The rates of radical resection for stage I, stage II, stage III, stage IVA, and stage IVB were 100%, 100%, 82.6%, 12.3% and 2.1% respectively. The 1-, 3- and 5-year survivals of stage I, II were 73.3%, 40.0% and 30.0% respectively, and higher than those of other groups.</p><p><b>CONCLUSIONS</b>The patients with pancreatic cancer diagnosed early can undergo radical resection. The elevation of early diagnosis rate is significant for the improvement of survival.</p>