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Objective To observe the effect of stress on the rapid component of delayed rectifier potassium current (IKr) in rat cardiomyocytes. Methods Forty male SD rats were randomly divided into four groups (10 each): control group (Ctrl), exhaustive group (ES), noise group (WN) and composite group (ES+WN). Stress animal models were prepared as follows: Rats in ES group were undergoing exhaustive swimming as the stress factor, in WN group undergoing white noise and in ES+WN group undergoing exhaustive swimming + white noise as the stress factor. Langendorff device was used to reversely perfuse collagenase for isolating the rat's ventricular myocytes. The effect of stress on IKr current and gating mechanism of single ventricular myocyte was recorded by whole-cell patch clamp technique. Results Compared with the Ctrl group, the tail current density of IKr (IKr,tail) of ventricular myocytes increased significantly in ES group and WN group (P<0.01). The IKr,tail current density of the ventricular myocytes in ES+WN group was significantly higher than that in ES group and WN group (P<0.01), and the effect was voltage dependent. Gating mechanism revealed that the half inactivation voltage of IKr,tail (V1/2,inact) can be shifted to the right in ES group, WN group and ES+WN group when compared with the Ctrl group, and the recovery time constant shortened after inactivation (P<0.01). However, the steady-state activation, fast inactivation constant and voltage dependence of IKr,tail were not statistically significant in ES group, WN group and ES+WN group when compared with the Ctrl group. Conclusion Stress increases the IKr current in rat cardiomyocytes, suggesting it be one of the electrophysiological bases of stress-induced arrhythmia.
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Objective To study the effect of allicin ( All) on potassium current in single atrial myocytes in rats. Methods Isolated rat atrial myocytes were isolated by perfusion and administered by extracellular perfusion method.Whole cell patch clamp technique was used to record transient outward potassium current ( Ito ) in atrial myocyte. Results In presence of 30 μmol·L-1 of All,the peak current of Ito was significantly reduced from (20.5±2.2) pA/pF to (11.3±2.1) pA/pF at+50 mV of test potential (P<0.01,n=12).This effect of All showed voltage- and concentration-dependence with IC50 of (19.0±2.5)μmol·L-1 .The steady-state activation curve of Ito was shifted to more positive potential and recovery time from inactivation was prolonged.In addition, they fail to find any effect of All on the steady-state inactivation and closed-state inactivation of Ito. Conclusion All can inhibit Ito by slowing down the process of activation and recovery from inactivation of channel.
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Objective To study the effect of allicin ( All) on potassium current in single atrial myocytes in rats. Methods Isolated rat atrial myocytes were isolated by perfusion and administered by extracellular perfusion method.Whole cell patch clamp technique was used to record transient outward potassium current ( Ito ) in atrial myocyte. Results In presence of 30 μmol·L-1 of All,the peak current of Ito was significantly reduced from (20.5±2.2) pA/pF to (11.3±2.1) pA/pF at+50 mV of test potential (P<0.01,n=12).This effect of All showed voltage- and concentration-dependence with IC50 of (19.0±2.5)μmol·L-1 .The steady-state activation curve of Ito was shifted to more positive potential and recovery time from inactivation was prolonged.In addition, they fail to find any effect of All on the steady-state inactivation and closed-state inactivation of Ito. Conclusion All can inhibit Ito by slowing down the process of activation and recovery from inactivation of channel.
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Objective To investigate the clinical value of sentinel lymph node biopsy(SLNB)in breast cancer.Methods SLNB by using a 1% methylene blue 2mL subcutaneous was performed in 138 female patients with breast cancer,clinical stage Ⅰ,Ⅱ,stage,aged from 32 to 55 years old.Results Identification rate,accuracy rate, sensitivity,false negative rate of SLNB were 94.2%,96.0%,91.1% and 8.1%.Conclusion SLNB can conduct clinical axillary lymph node dissection narrow range,reduce the surgical trauma and postoperative complications.Ⅰ,Ⅱ sentinel lymph node -negative breast cancer patients may not have ipsilateral axillary dissection.
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Objective To investigate clinical effects of neoadjuvant chemotherapy(NAC)for phase II B breast cancer.Methods From Jan.2002 to Nov.2004,330 female patients with phase II B unilateral breast cancer were enrolled in the study and they were randomly divided into 2 groups.Group A was NAC group and 152 cased were enrolled in this group,among whom 78 cases had left-side cancer and 74 cases had right-side cancer.The mean age of group A was 42.6 years(ranging from 32 to 73 years).Group A were given beth taxane-and anthracycline- based chemotherapy,according to the protocol of group A.After 4 cycles of chemotherapy,patients in group A underwent conservative breast surgery or radical mastectomy according to the result of chemotherapy.Group B,the non-NAC group,had 178 cases in it,among whom 98 had left-side cancer and 80 had rightside cancer.The mean age of group B was 41.4 years(ranging from 31 to 72 years).Group B also underwent conservative breast surgery or radical mastectomy according to tumor size and axillary node status.According to standards of International Union against Cancer(UICC),the primary focus and axillary node status in NAC group were analyzed before and after chemotherapy.Results Group A had a total effective rate of 91.45%.Breast conservation rate in group A and group B was 44.70%and 21.90%respectively.The overall 3 and 5 year survival rate in group A was 96.05%and 75.00%respectively.which was significantly higher than that in group B.Conclusion NAC is effective in reducing clinical stage of phase II B breast cancer,which increases breast conservation rate and postoperative survival rate.
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Objective To establish a HPLC method for determination of Chlorogenic acid in Liyan Granule. Method The determination was performed on Diamondsil Cl8 (4.6 mm?150 mm, 5 ?m) with mobile phase consisted of acetonitrile-0.4% phosphonic acid solution (13∶87) at a flow rate of 1.0 mL/min. The detective wavelength was set at 327 nm. Result The linear range of Chlorogenic acid was 0.026～0.26 ?g (r =0.999 9) and the average recovery rate of Chlorogenic acid was 101.84% (RSD=0.48%, n =6). Conclusion This method is simple, accurate and with good stabilization, and suitable for the quality control of Liyan gramule.