Effects of autoantibodies against β_1-adrenoceptor in hepatitis virus myocarditis on action potential and L-type Ca^(2+) currents

AIM:To investigate the effects of autoantibodies against β_1-adrenoceptor in hepatitis virus myocarditis on action potential and L-type Ca^(2+) currents. METHODS:Fifteen samples of autoantibodies against β_1- adrenoceptor positive sera of patients with hepatitis virus myocarditis were obtained and IgGs were purified by octanoic acid extraction.Binding of autoantibodies against β_1- adrenoceptor to guinea pig cardiac myocytes was examined by immunofluorescence.Using the patch clamp technique, the effects on the action potential and I_(ca-L) of guinea pig cardiac myocytes caused by autoantibodies against β_1-adrenoceptor in the absence and presence of metoprolol were investigated. Cell toxicity was examined by observing cell morphology and permeability of cardiac myocytes to trypan blue. RESULTS:The specific binding of autoantibodies against β_1-adrenoceptor to guinea pig cardiomyocytes was observed. Autoantibodies against β_1-adrenoceptor diluted at 1:80 prolonged APO_(20),APD_(50)and APD_(90) by 39.2%,29.1% and 15.2% respectively,and only by 7.2%,5.3% and 4.1% correspondingly in the presence of 1 μmol/L metoprolol. Autoantibodies against β_1-adrenoceptor diluted at 1:80, 1:100 and 1:120 significantly increased the I_(ca-l) peak current amplitude at 0 mV by 55.87±4.39%,46.33±5.01% and 29.29±4.97% in a concentration-dependent manner.In contrast,after blocking of β_1-adrenoceptors (1 μmol/L metoprolol),autoantibodies against β_1-adrenoceptor diluted at 1:80 induced a slight increase of I_(ca-L) peak amplitude only by 6.81±1.61%.A large number of cardiac myocytes exposed to high concentrations of autoantibodies against β_1- adrenoceptor (1:80 and 1:100) were turned into rounded cells highly permeable to trypan blue. CONCLUSION:Autoantibodies against β_1-adrenoceptor may result in arrhythmias and/or impairment of myocardiums in HVM,which would be mediated by the enhancement of I_(ca-L.

Expression of cyclooxygenase-2 in human esophageal squamous cell carcinomas

AIM: To determine whether cyclooxygenase-2 (COX-2) wasm expressed in human esophageal squamous cell carcinoma.METHODS: Quantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, immunohistochemistry and immunofluorescence were used to assess the expression level of COX-2 in esophageal tissue.RESULTS: COX-2 mRNA levels were increased by >80-fold in esophageal squamous cell carcinoma when compared to adjacent noncancerous tissue. COX-2 protein was present in 21 of 30 cases of esophageal squamous cell carcinoma tissues, but was undetectable in noncancerous tissue. Immunohistochemistry was performed to directlyshow expression of COX-2 in tumor tissue.CONCLUSION: These results suggest that COX-2 may be an important factor for esophageal cancer and inhibition of COX-2 may be helpful for prevention and possibly treatment of this cancer.

Relationship between encephalopathy and portal vein-vena cava shunt:Value of computed tomography during arterial portography

AIM: TO assess the value of computed tomography during arterial portography (CTAP) in portal vein-vena cava shunt,and analysis of the episode risk in encephalopathy.METHODS: Twenty-nine patients with portal-systemic encephalopathy due to portal hypertension were classified by West Haven method into grade Ⅰ(29 cases), gradeⅡ(16 cases), grade Ⅲ(10 cases), grade Ⅳ( 4 cases). All the patients were scanned by spiraI-CT. Plane scans, artery phase and portal vein phase enhancement scans were performed, and the source images were thinly reconstructed to 1.25 mm. We reconstructed the celiac trunk, portal vein,inferior vena cava and their branches and subjected them to three-dimensional vessel analysis by volume rendering(VR) technique and multiplanar volume reconstruction (MPVR) technique. The blood vessel reconstruction technique was used to evaluate the scope and extent of portal vein-vena cava shunt, portal vein emboli and the fistula of hepatic artery- portal vein. The relationship between the episode risk of portal-systemic encephalopathy and the scope and extent of portal vein-vena cava shunt,portal vein emboli and fistula of hepatic artery- portal vein was studied.RESULTS: The three-dimensional vessel reconstruction technique of spiraI-CT could display celiac trunk, portal vein,inferior vena cava and their branches at any planes and angles and the scope and extent of portal vein-vena cavashunt, portal vein emboli and the fistula of hepatic artery- portal vein. In twenty-nine patients with portal-systemicencephalopathy, grade Ⅰ accounted for 89.7% esophageal varices, 86.2% paragastric varices; grade Ⅱ accounted for 68.75% cirsomphalos, 56.25% paraesophageal varices,62.5% retroperitoneal varices and 81.25% dilated azygos vein; grade Ⅲ accounted for 80% cirsomphalos, 60%paraesophageal varices, 70% retroperitoneal varices, 90% dilated azygos vein, and part of the patients in grades Ⅱand Ⅲ had portal vein emboli and fistula of hepatic arteryportal vein; grade Ⅳ accounted for 75% dilated left renal vein, 50% paragallbladder varices, all the patients had fistula of hepatic artery- portal vein.CONCLUSION: The three-dimensional vessel reconstruction technique of spiraI-CT can clearly display celiac trunk, portal vein, inferior vena cava and their branches at any planes and angles and the scope and extent of portal vein-vena cava shunt. The technique is valuable for evaluating the episode risk in portal-systemic encephalopathy.

Action and mechanism of Fas and Fas ligand in immune escape of gallbladder carcinoma

AIM: To study the role of Fas and Fas ligand (FasL) in biological behaviors of gallbladder carcinoma, and their correlated action and mechanism in tumor escape.METHODS: Streptavidin-biotin-peroxidase immunohistochemistry technique was used to study the expression of Fas and FasL protein in 26 gallbladder carcinoma tissues,18 gallbladder adenoma tissues, 3 gallbladder dysplasia tissues and 20 chronic cholecystitis tissues. Apoptosis of the infiltrating lymphocytes in these tissues was studied by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method. Expression of both proteins and apoptosis of the tumor infiltrating lymphocytes in cancer tissues of primary foci was compared with clinicopathological features of gallbladder carcinoma.RESULTS: The positive rates of Fas were not significantly different among carcinoma, adenoma, dysplasia and chronic cholecystitis. The positive rate of FasL in carcinoma was significantly higher than that in chronic cholecystitis (x2 = 4.89, P＜0.05). The apoptotic index (AI) in carcinoma was significantly higher than that in adenoma (t'= 4.19, P＜0.01) and chronic cholecystitis (t'= 8.06, P＜0.01). The AI was significantly lower in well-differentiated carcinoma and Nevin Ⅰ-Ⅲ carcinoma than that in poorly-differentiated carcinoma (t'= 2.63, P＜0.05) and Nevin Ⅳ-Ⅴ carcinoma(t'= 3.33, P＜0.01). The confidence interval (CI) ofinfiltrating lymphocytes in adenoma, chronic cholecystitis, well-differentiated carcinoma and Nevin Ⅰ-Ⅲ carcinoma wasvery significantly lower than that in carcinoma (t' = 6.99,P＜0.01), adenoma (t' = 3.66, P＜0.01), poorly-differentiated carcinoma (t' = 5.31, P＜0.01) and Nevin Ⅳ-Ⅴ carcinoma(t' = 3.76, P＜0.01), respectively. The CI of apoptosis of infiltrating lymphocytes in well-differentiated carcinoma was significantly lower than that in poorly-differentiated carcinoma (t = 2.52, P＜0.05), and was not significantly lower in Nevin Ⅰ-Ⅲ carcinoma than in Nevin Ⅳ-Ⅴ carcinoma (t = 1.42, P＞0.05). Apoptosis of infiltrating lymphocytes was not discovered in adenoma and chronic cholecystitis. CONCLUSION: FasL expressed in gallbladder carcinoma cells permits tumor cells to escape from immune surveillance of organism by inducing apoptosis in infiltrating lymphocytes of carcinoma tissues. Up-regulation of FasL expression plays an important role in invasive depth, histological classification and metastasis of gallbladder carcinoma.

Cell apoptosis and regeneration of hepatocellular carcinoma after transarterial chemoembolization

AIM: To evaluate whether cell apoptosis and regeneration were existed in normal liver cells adjacent to carcinoma after transarterial chemoembolization (TACE).METHODS: Fifty rabbits with hepatic carcinoma were divided into 5 groups at random: group A (control group),groups B and C (TACE treatment groups), groups D and E (partial hepatectomy groups). There were 10 rabbits in each group. Rabbits in groups B-E were treated by transartedal chemoembolization (TACE) and partial hepatectomy (PH) respectively. The changes of S-phase cell fraction (SPF),proliferation index (PI) and cell apoptosis in the normal liver tissue were determined with flow cytometry (FCM) after operations on the first and third days. We determined the mitosis index (MI) with histo-pathological method and the apoptosis index (AI) with TUNEL method at the same time.RESULTS: Twenty-four hours after operations, compared with control group, the rabbits in TACE group had much higher index of SPF, PI and MI (MI: t=-4.89, P<0.001; SPF:t=-5.27, P<0.001; PI: ~4.87, P<0.001). Moreover, the proliferation of liver cells in TACE group was much weaker than that of the cells treated by partial hepatectomy, and the differences were significant (MI: t=7.02, P<0.001; SPF:t=-4.06, P<0.001; PI: t=2.70, P<0.05). Seventy-two h after operations, FCM showed a small sub-G1 peak in TACE group and PH group, compared with the control group, but there was no difference between them (t=0.41, P>0.05).TACE showed that AI in the treated rabbits was higher than that in control group (t=-3.07, P<0.05), and there were no differences between TACE group and PH group, either(t=0.93, P>0.05).CONCLUSION: Cell apoptosis and regeneration exist in rabbit liver tissues after TACE in some degree, which may be associated with the selective embolization of iodised oil, chemotherapeutic drug and free radical damage.

Inhibitory effects of berberine on ion channels of rat hepatocytes

AIM: To examine the effects of berberine, an isoquinoline alkaloid with a long history used as a tonic remedy for liver and heart, on ion channels of isolated rat hepatocytes.METHODS: Tight-seal whole-cell patch-clamp techniques were performed to investigate the effects of berberine on the delayed outward potassium currents (Ik), inward rectifier potassium currents (Ik1) and Ca^2+ release-activated Ca^+ currents (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Berbenne 1-300 μmol/L reduced/K in a concentration-dependent manner with EC50 of 38.86=1=5.37 μmol/L and nH of 0.82±0.05 (n = 8). When the bath solution was changed to tetraethylammonium (TEA) 8 retool/L,IK was inhibited.Berberine 30 μmol/L reduced/K at all examined membranepote ntials, especially at potentials positive to +60 mV (n = 8,P<0.05 or P<0.01 vs control). Berberine had mild inhibitory effects on IK1 in rat hepatocytes. Berberine 1-300 μmol/L also inhibited ICRAC in a concentration-dependent fashion. The fitting parameters were EC50 = 47.20±10.86 μmol/L,nH= 0.71±0.09 (n = 8). The peak value of/CRAC in the I-Vrelationship was decreased by berberine 30 μmol/L at potentialnegative to -80 mV (n = 8, P<0.05 vscontrol). But the reverse potential of/CRAC occurred at voltage 0 mV in all cells.CONCLUSION: Berberine has inhibitory effects on potassium and calcium currents in isolated rat hepatocytes, which may be involved in hepatoprotection.

Effects of palmatine on potassium and calcium currents in isolated rat hepatocytes

AIM: To study the effects of palmatine, a known inhibitoron delayed rectifier potassium current and L-type calciumcurrent (ICa,L) in guinea pig ventricular myocytes, on thepotassium and calcium currents in isolated rat hepatocytes.METHODS: Tight-seal wh ole-cell patch-clamp techniqueswere performed to investigate the effects of palmatine onthe delayed outward potassium currents (IK), inward rectifierpotassium current (IK1) and Ca2+ release-activated Ca2+current (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Palmatine 0.3-100 μM reduced IK in a concentationdependent manner with EC50of 41.62±10.11 μM and nH,0.48±0.07 (n=8). The effect of the drug was poorly reversibleafter washout. When the bath solution was changed totetraethylammonium (TEA) 8 mM, IK was inhibited.Palmatine 10 μM and 100 μM shifted the I-V curves of IKdownward, and the block of IK was voltage-independent.Palmatine 0.3-100 μM also inhibited ICRAC in a concentration-dependent manner. The fitting parameters were as follows:ECs0=51.19±15.18 μM, and nH=0.46+0.07 (n=8). The peakvalue of ICRAC in the I-V relationship was decreased bypalmatine 10 μM and 100 μM. But the reverse potential ofIcRAcoCcurred at Voltage=0 mV in all cells. Palmatine 0.3-100 μM failed to have any significant effect on either inwardor outward components of IK1 at any membrane potentialexamined.CONCLUSION: The inhibitory effects on IK and ICRAC couldbe one of the mechanisms that palmatine exerts protectiveeffect on hepatocytes.

Electrophysiological effects of anthopleurin-Q on rat hepatocytes

AIM: To study the effects of AP-Q on CCl4-induced acute liver injury, delayed outward potassium current (Iκ), inward rectifier potassium current (Iκ1) and calcium release-activated calcium current (ICRAC) in isolated rat hepatocytes. METHODS: A single dose of CCl4 (10 μg/mL, ip) was injected to induce acute liver injury in rats. Serum aminotransferase activities were determined. Whole cell patch-clamp techniques were used to investigate the effects of AP-Q on delayed outward potassium current (Iκ), inward rectifier potassium current (IKI) and calcium release-activated calcium current (ICRAC). RESULTS: AP-Q (3.5 and 7 μg/kg) pretreatment significantly reduced ALT and AST activities. AP-Q 0.1-100 nM produced a concentration-dependent increase of Iκ with EC50 value of 5.55±1.8 nM (n=6). AP-Q 30 nM shifted the I-V curve of Iκ leftward and upward. CCl4 4 mM decreased Iκ current 28.6±0.5% at 140 mV. After exposure to CCl4 for 5 rain, AP-Q 30 nM attenuated the decrease of Iκ induced by CCl4 close to normal amplitude. AP-Q 0.01-100 nM had no significant effect on either inward or outward components of Iκ1 at any membrane potential examined. AP-Q 0.1-100 nM had no significant influence on the peak amplitude of ICRAC, either,and did not affect the shape of its current voltage curve. CONCLUSION: AP-Q has a protective effect on CCl4-induced liver injury, probably through selectively increased Iκ in hepatocytes.

Developmental changes in functional expression andβ-adrenergic regulation of If in the heart of mouse embryo

The hyperpolarization-activated current (If) plays an important role in determining the spontaneous rate of cardiac pacemaker cells. The automatic rhythmicity also exists in working cells of embryonic heart, therefore we studied developmental changes in functional expression and β-adrenergic regulation of Iy in embryonic mouse heart. The expression of If is high in early developmental stage (EDS) (10.5 d after coitus) ventricular myocytes, low in intermediate developmental stage (IDS) (13.5 d) atrial or ventricular myocytes and even lower in late developmental stage (LDS) (16.5 d) atrial or ventricular myocytes, indicating that these cells of the EDS embryonic heart have some properties of pacemaker cells.β-adrenergic agonist isoproterenol (ISO) stimulates If in LDS but not in EDS cardiomyocytes, indicating that the β-adrenergic regulation of If is not mature in EDS embryonic heart. But forskolin (a direct activator of adenylate cyclase) and 8-Br-cAMP (a membrane-permeable analogue of cAMP) increase the amplitude of If in EDS cells, indicating that adenylate cyclase and cAMP function fairly well at early stage of development. Furthermore, the results demonstrate that If is modulated by phosphorylation via cAMP dependent PKA both in EDS and LDS cells.

Effect of protective myocardium by allitridum from decreasing apoptosis in rats with ischemia/reperfusion injury

Objective: Previous studies have shown t hat allitridum can protect myocardium from ischemia/reperfusion (I/R) injury, bu t whether allitridum had the effect of anti-apoptosis is unclear. The aim of th is study was to investigate whether allitridum had the effects of pharmacologica l preconditioning and decreasing myocardium apoptosis after ischemic insult. Methods: Pentobarbital sodium-anesthetized Sprague-Dawley (SD) rats underwent 30 min of left anterior descending (LAD) coronary occlusion foll owed by 120 min of reperfusion. Thirty-six rats were divided into three groups randomly: Control group, I/R group and allitridum (G) group. The control and I/R groups with saline, G group with allitridum were administrated 24 h before oper ation. Control group underwent only sham operation; the other two groups underwe nt I/R operation. Infarcted size (IS/AAR %) was measured in I/R and G groups. Ma londialdehyde (MDA), Creatine kinase isoenzyme-MB (CK-MB ), Superoxide dismuta se (SOD)and the apoptosis index (AI) by TUNEL staining were measured in each gro up. In addition, DNA fragmentation by agarose gel electrophoresis was conducted on DNA isolated from these groups. Results: Allitridum p retreatm ent decreased the infarcted size compared with I/R group in IS/ AAR%[(21.85±1. 49)% vs. ( 44.65±4.65)%, P<0.01], CK-MB [(986.40±94.01) vs. (2044.2 5±1 07.28) U/L, P<0.01] and MDA [(3.26±0.35) vs. (4.96±0.46) nmol/mg pro, P<0.01], and SOD level in G group was higher than that of I/R group [(140 .20±12.89)vs. (73.16±11.22) U/mg pro, P<0.01]. AI of I/R group was highe r than that of G group [(13.99±3.05)% vs. (6.97±1.23)%, P<0.01], which was consistent with that in DNA fragmentation by agarose gel electrophoresis. Conclusion: This study indicated that allitridum had the effect of protecting myocardium against I/R injury and decreasing infarcted zone. The e ffect was probably through decreasing myocardium apoptosis in I/R injury.

Effect of PAMd on proteins expression of Bax and Bcl-2 of nerve cells in the brain tissue of ischemia-reperfusion mice

AIM : To study the effects of PAMd ( Phenolic alkaloids from Menispermum dauricum on Brain ischemia and ischemic reperfusion injury in mice. METHODS : Bilateral carotid arteries of mice were ligated and 0. 3ml blood was letted from post-eyeball venous jungle, one hour later the carotid arteries were loosed. After cerebral ischemia-reperfusion,

Effects of Losartan on L-type Calcium Current in Hypertrophied RatMyocytes

Objective To investigate the alterations of L-type calcium current (IcaL) in abdominal aorticligation-induced hypertrophied rat hearts and the effect of losartan on these alterations. METHODS Cardiachypertrophy was induced by abdominal aortic ligation in rats. To record IcaL, whole-cell patch-clamp technique wasused. RESULTS Membrane capacitance was larger in hypertrophied cells (148±29 pF) than in sham-operated cells(102±14 pF, P<0.01) and losartan-treated cells (118±27, P<0.01). The maximal peak IcaL Was increased from-835±124 pA in sham-operated cells to -1404+_417 pA in hypertrophied cells (P<0.01), the corresponding IcaL density was increased from -7.5±1.8 pA.pF^1 to -10.5±2.2 pA.pF^1 (P<0.01), while they were reduced to -956-2:170pF (P<0.01) and -8.2±1.6 pA.pF^1 (P<0.05) respectively in losartan-treated cells. The membrane potential of halfmaximal activation of the hypertrophied cells (-20.6±1.0 mV) shifted to more negative potentials than sham-operatedcells (-15.6±1.6 mV, P<0.01) and lorsartan-treated cells (-17.4±1.0 mV, P<0.01). The slope of the activation curveof hypertrophied cells (5.7±0.4) was decreased slightly than sham-operated cells (6.4±0.5, P<0.05). The membranepotential of half maximal inactivation of hypertrophied cells (-27.6±1.9 mV) shifted to more positive potentials thansham-operated cells (-31.4±2.2 mV, P<0.05). The slope of inactivation curves were not different in the three groups.

Intra—Operative Facial Nerve Monitoring in Acoustic Neurinoma Surgery

Objective To determine the method and significance of facial nerve preservation during acoustic neurinoma surgery by intra-operative facial nerve monitoring(IFNM).Methods 62 patients were randomly assigned to the IFNM or the control group.Facial nerve function(FNF)was assessed by a modified House-Brackmann grading(HB)before the operation,10 days and every two months after surgery and com,pared between the two groups. Results Ten days after surgery,26/32 patients in the IFNM group and 15/30 patients in the control group had FNF HB grade,Ⅰ-Ⅲ；FNF HB gradeⅣ-Ⅴ was prestent in 6/32 in the IFNM group and 15/30 in the control group.During follow-up,29/32 patients in the IFNM group and 20/20 patients in the control group had FNF HB gradeⅠ-Ⅲ;FNF HB gradeⅣ-Ⅴ was present in 3/32 in the IFNM group and 10/30 in the control group.All differnces were statistcally significant.Conclusion IFNM significantly improved anatomic and functional facial nerve preservation as well as the quality of life.

Effect of simvastatin on pro-inflammatory cytokines after myocardial in farction in rats

Objective: To study the effect of simv astatin on mRNA expression of inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-10, after myocardial infarction (MI) in rats. Methods: The experimental rats were di vided into three groups: Sham operation group (Sham), the rats were performed a left thoracotomy with no ligation of left descending coronary artery (LAD); Myoc ardial infarction control group (MI-C), the rats were performed a left thoracot omy with ligation of LAD; Simvastatin group (MI-S), the rats were performed a l eft thoracotomy with ligation of LAD, and given simvastatin 40 mg/kg body weight per day through gavage, while the other two groups were given equal normal sali ne by gavage. All animals were caged to feed four weeks. After finished, the rat s were killed, and the hearts were harvested and cut into two equal parts at the level of the papillary muscle: one was used to determine mRNA expression of myo cardial cytokines by RT-PCR, and the other was used to measure cytokines by Wes tern blotting and immunohistochemical staining. Results: All the pro-inflammatory cytokines mentioned above showed few expression in Sham opera tion group. In the MI groups (including MI-C and MI-S groups), mRNA expression of each of these cytokines markedly increased compared with the Sham operation group (P<0.01). Compared with MI-C group, the mRNA expression of TNF- α, IL-1β and IL-6 in the MI-S group significant ly reduced (P<0.01), and mRNA expression of IL-10 obviously increased ( P<0.01). Cytokines principally located in cardiomyocytes of non-infarcted ar ea and survived cardiomyocytes of infarcted area, simvastatin could decrease TNF -α, IL-1β, and IL-6 and increase IL-10 by confirmation of immunohistochemical staining. Conclusion: Simvas tatin markedly lowers pro-inflammatory cytokines, and increases inflammatory pr otective cytokine. Its mechanism needs to be elucidated.

Anti-apoptosis effect of taurine on cerebral ischemia in rat

Aim To study anti -apoptosis effect of taurine on cerebral ischemia in rat. Methods 1. in vivo: taurine (250mg/Kg.d) was administrated by i. p. for one week in treated group. A nylon suture was inserted into fight internal carotid artery to occlude the beginning of middle cerebral artery (MCAO). After 3 hours'permanent occlusion, neurology deficit