OBJECTIVETo study the changes of p38MAPK expressions, the frequency of apoptosis and the distribution of cell cycle of hunan Glioma U251 cells after HCMV infection.

METHODSThe expression of total p38 (both phosphorylated and nonphosphorylated p38) and phosphorylated p38 in U251 cells were detected by Western blotting at 15 min, 30 min, 1 h, 6 h, 10 h, 16 h, 24 h, 36 h and 48 h after HCMV infection. The apoptosis percentage and the cell cycle distribution of U251 cells at 2 d, 5 d and 7 d after HCMV infection were detected by flow cytometry (FCM).

RESULTSThe results of Western blotting demonstrated that a strong increase in phosphorylated p38 was detected from 6 h to 10 h after HCMV infection, with mean gray scales 186.33 +/- 7.51 (t = 5.37, P < 0.01) and 188.00 +/- 7.02 (t = 5.26, P < 0.01 for all) at 6 h and 10 h, respectively, and p38 phosphorylation decreased to the basic level at 16 h after HCMV infection. But the overall levels of p38 protein were not significantly altered during the course of infection. FCM analysis showed that HCMV could significantly increase the apoptotic rates of U251 cells compared with controls (t = 10.84, P < 0.01), and the apoptotic percentages of the cells reached to peak [(10.18 +/- 1.24)%] at 5 d after HCMV infection. The data of FCM showed that HCMV could decrease the number of U251 cells in G1 phase and arrest the cells in S and G2 phase. The numbers of G1 phase U251 cells were significantly lowered to (56.50 +/- 2.57)% (t = 26.45, P < 0.01), (62.33 +/- 2.64)% (t = 21.20, P < 0.01) and (67.45 +/- 4.44)% (t = 10.61, P < 0.01), respectively at 2 d, 5 d and 7 d after infection.

CONCLUSIONHCMV could activate p38MAPK pathway and trigger apoptosis and interfere cell cycle in U251 cells.

Apoptosis ; Blotting, Western ; Cell Cycle ; Cell Line, Tumor ; Cytomegalovirus ; isolation & purification ; Cytomegalovirus Infections ; metabolism ; physiopathology ; Flow Cytometry ; Glioma ; metabolism ; microbiology ; pathology ; Humans ; MAP Kinase Signaling System ; Phosphorylation ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo evaluate the effects of W-7, a calmodulin inhibitor, on transmural dispersion of repolarization (TDR), early after depolarization (EAD) and torsade de pointes (TdP) induction after administration of d-sotalol in isolated rabbit heart.

METHODSTdP was induced by d-sotalol (30 micromol/L), bradycardia, and hypokalemic (1.5 mmol/L)/hypomagnesaemic (0.35 mmol/L) solution in isolated female rabbit hearts. Thirty six rabbit hearts were divided into 4 groups (n = 9 each): d-sotalol alone, d-sotalol + W-7 (20 micromol/L), d-sotalol + W-7 (50 micromol/L), and d-sotalol + W-7 (100 micromol/L). Monophasic action potentials (MAPs) of the left ventricular epimyocardium (Epi), midmyocardium (M), and endomyocardium (Endo) were recorded simultaneously with ECG. The incidence of EAD and TdP were observed as well.

RESULTSTreatment with d-sotalol alone prolonged ventricular MAP duration and QT interval, increased TDR, and evoked high incidence of EAD (9/9) and spontaneous TdP (7/9) in hypokalemic/hypomagnesaemic solution in female rabbit heart. W-7 concentration-dependently decreased incidence of TdP (4/9 in 20 micromol/L; 2/9 in 50 micromol/L; 1/9 in 100 micromol/L). This effect of W-7 coincided with the decreased incidence of EAD (5/9 in 20 micromol/L; 4/9 in 50 micromol/L; 1/9 in 100 micromol/L). However, the d-sotalol-induced prolongation of QT interval and TDR was not significantly altered by W-7 at the three concentration used.

CONCLUSIONSIn isolated female rabbit hearts, calmodulin antagonist W-7 suppresses d-sotalol-induced TdP without altering TDR but does suppress EAD. The effects observed with W-7 also suggest a possible important role for calmodulin-activated enzymes in the induction of TdP.

Animals ; Calmodulin ; antagonists & inhibitors ; Enzyme Inhibitors ; therapeutic use ; Female ; In Vitro Techniques ; Rabbits ; Sotalol ; adverse effects ; Sulfonamides ; therapeutic use ; Torsades de Pointes ; chemically induced ; prevention & control

BACKGROUND: Calcium calmodulin-dependent kinase Ⅱ (CaMKⅡ) can be more active in patients with left ventricular hypertrophy (LVH), which in turn causes phosphorylation of ryanodine receptors, resulting in inactivation and the instability of intracellular calcium homeostasis. The present study aimed to determine the effect of CaMKⅡ–ryanodine receptor pathway signaling in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia. METHODS: Forty New Zealand rabbits were randomized into four groups (10 per group): sham group, LVH group, KN-93 group (LVH+KN-93), and ryanodine group (LVH+ryanodine). Rabbits in the LVH, KN-93, and ryanodine groups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta, while those in the sham group did not undergo the coarctation. After eight weeks, action potentials (APs) were recorded simultaneously in the endocardium and epicardium, and a transmural electrocardiogram (ECG) was also recorded in the rabbit left ventricular wedge model. Drugs were administered to the animals in the KN-93 and ryanodine groups, and the frequency of triggered APs and ventricular tachycardia was recorded after the rabbits were given isoprenaline (1 mol/L) and high-frequency stimulation. RESULTS: The frequency (animals/group) of triggered APs was 0/10 in the sham group, 10/10 in the LVH group, 4/10 in the KN-93 group, and 1/10 in the ryanodine group. The frequencies of ventricular tachycardia were 0/10, 9/10, 3/10, and 1/10, respectively. The frequencies of polymorphic ventricular tachycardia or ventricular fibrillation were 0/10, 7/10, 2/10, and 1/10, respectively. The frequencies of triggered ventricular arrhythmias in the KN-93 and ryanodine groups were much lower than those in the LVH group (P<0.05). CONCLUSIONS: KN-93 and ryanodine can effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH. The CaMKⅡ–ryanodine signaling pathway can be used as a new means of treating ventricular arrhythmia.

OBJECTIVEThe purpose of our study is to observe the voltage-gated potassium channel Kv1.3 expression on CD4+CD28null T cells from the peripheral blood of ACS patients by the patch clamp technique.

METHODSKv1.3 potassium channels expression from 17 patients with ACS and 11 healthy age-matched normal controls was detected in single cell (CD4+CD28null T cells and CD4+CD28+ T cells) by fluorescence microscopy and patch clamp.

RESULTSThe percent of CD4+CD28nullT cells are higher in the ACS (6.97% +/- 2.05%) than that in the controls (1.38% +/- 0.84%, P < 0.05). The concentration of hsCRP is directly correlated with the number of the CD4+CD28null T cells in the ACS (r = 0.52, P < 0.05). The conductance [(6.89 +/- 1.17) nS vs. (3.36 +/- 0.66) nS], dens [(1.95 +/- 0.80) n/microm2 vs. (1.13 +/- 0.57) n/microm2] and numbers [(574.5 +/- 97.6) n/cell vs. (280.3 +/- 55.3) n/cell] of the Kv1.3 channels on the CD4+CD28null T cells are significantly higher than those on the CD4+CD28+ T cells (all P < 0.01) in ACS patients, but were similar on CD4+CD28+ T cells between ACS patients and controls.

CONCLUSIONThe CD4+CD28null T cells in the ACS and the numbers of Kv1.3 channels on the CD4+CD28null T cells from the ACS patients are significantly upregulated and might contribute to the pathogenesis of ACS.

Acute Coronary Syndrome ; blood ; immunology ; metabolism ; Aged ; CD28 Antigens ; metabolism ; CD4-Positive T-Lymphocytes ; metabolism ; Case-Control Studies ; Female ; Humans ; Kv1.3 Potassium Channel ; metabolism ; Male ; Middle Aged ; Patch-Clamp Techniques

OBJECTIVETo determine current density of voltage-gated potassium channels and Kv1.3 express in T-lymphocyte derived from patients with acute coronary syndrome (ACS).

METHODSPeripheral blood mononuclear cells were collected from 12 patients with ACS and 10 control donors. Whole-cell patch clamp technique was used to record the outward K(+) currents (IK) and western blots technique was used to detect the express of Kv1.3 protein in lymphocyte.

RESULTS(1) The current density of voltage-gated potassium channel was significantly higher in ACS patients [(269 +/- 94) pA/pF] than in controls [(191 +/- 64) pA/pF, P < 0.01] while membrane capacitance was similar between the two groups. (2) Kv1.3 protein expression was also significantly increased in ACS patients than in controls (P < 0.01).

CONCLUSIONThe lymphocyte voltage-gated potassium channel is upregulated in patients with ACS suggesting a role of Kv activation in the pathophysiology of ACS.

Acute Coronary Syndrome ; metabolism ; Adult ; Aged ; Female ; Humans ; Kv1.3 Potassium Channel ; metabolism ; Male ; Middle Aged ; Patch-Clamp Techniques ; T-Lymphocytes ; metabolism

OBJECTIVETo investigate the effect and potential mechanism of lysophosphatidic acid (LPA) and antiarrhythmic peptide (AAP10) on rabbit ventricular arrhythmia.

METHODSTwenty-four rabbits were randomly divided into three groups (n = 8 each): control group, LPA group and AAP10 + LPA group. Using arterially perfused rabbit ventricular wedge preparations, transmural ECG and action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments with two separate floating microeletrodes. The incidence of ventricular arrhythmia post S1S2 stimulation was recorded. Protein levels of nonphosphorylated Cx43 and total Cx43 were evaluated by Western blot. The distribution of nonphosphorylated Cx43 was observed by confocal immunofluorescence microscopy.

RESULTSCompared with the control group, the QT interval, endocardial action potential duration, transmural repolarization dispersion (TDR) and incidence of ventricular arrhythmia were significantly increased and nonphosphorylated Cx43 expression was significantly upregulated in the LPA group. Compared with the LPA group, cotreatment with AAP10 can reduce the QT interval, endocardial action potential duration, TDR and incidence of ventricular arrhythmia (25.0% vs 62.5%, P < 0.01) and downregulate nonphosphorylated Cx43.

CONCLUSIONSLPA could promote the arrhythmia possibly by upregulating nonphosphorylated Cx43 and subsequent gap junction transmission inhibition. Gap junction enhancer AAP10 could attenuate the pro-arrhythmic effect of LPA probably by downregulating myocardial nonphosphorylated Cx43 expression.

Animals ; Anti-Arrhythmia Agents ; pharmacology ; Arrhythmias, Cardiac ; chemically induced ; metabolism ; physiopathology ; Connexin 43 ; metabolism ; Lysophospholipids ; adverse effects ; Oligopeptides ; pharmacology ; Rabbits

OBJECTIVETo evaluate the effects of antiarrhythmic peptide (AAP10) on ventricular arrhythmias in rabbits with healed myocardial infarction (OMI).

METHODSThirty rabbits were randomly divided into three groups (n = 10 each): Sham group, left thoracotomy was performed without coronary ligation; OMI group and OMI + AAP10 group, the circumflex coronaries were ligated. Three months post operation, the electrophysiological and antiarrhythmic effects of AAP10 were assessed in the arterially perfused rabbit left ventricular wedge preparation. Sham and OMI group were perfused with Tyrode's solution and OMI + AAP10 group was perfused with Tyrode's solution + AAP10 (80 nmol/L). Transmembrane action potentials were recorded simultaneously from endocardium and epicardium together with a transmural ECG by use of 2 separate intracellular floating microelectrodes. The stimulus-response-interval (SRI) of the epicardium and the incidence of ventricular tachycardia (VT) were observed. Whole heart and left ventricular weights, the left ventricular thickness at infarct border zone were measured.

RESULTSWhole heart and left ventricular weights as well as the left ventricular thickness at the infarct border zone significantly increased post infarction. VT was induced in 8 out of 10 rabbits in OMI group and in 2 out of 10 rabbits in OMI + AAP10 group (P < 0.05). SRI was also significantly shortened in OMI + AAP10 group compared to OMI group [SRI-1: (20.59 +/- 0.79) ms vs. (28.71 +/- 0.55) ms; SRI-2: (30.42 +/- 0.74) ms vs. (38.67 +/- 0.49) ms, all P < 0.01]. However, the action potential morphology and duration were similar between OMI and OMI + AAP10 groups.

CONCLUSIONThe antiarrhythmic peptide (AAP10) can increase gap junctional intercellular conductance without affecting the action potential morphology and duration and decrease the incidence of inducible ventricular tachycardia.

Animals ; Arrhythmias, Cardiac ; etiology ; prevention & control ; Male ; Myocardial Infarction ; complications ; physiopathology ; Oligopeptides ; pharmacology ; Rabbits ; Random Allocation

OBJECTIVEThe aim of this study is to observe the effect of combined amiodarone and antiarrhythmic peptide (AAP10) use on the incidence of induced ventricular arrhythmias in healed myocardial infarction (MI) rabbits.

METHODSTwenty Japanese rabbits underwent thoracotomy without coronary artery ligation (Sham, group A), the middle left circumflex branch were ligated to induce MI in 180 Japanese rabbits. Eight weeks after operation, 124 rabbits survived MI operation and were divided into four groups: control group (group B, n = 31), amiodarone group (group C, n = 31), AAP10 group (group D, n = 31) and amiodarone plus AAP10 group (group E, n = 31). The A and B and D groups were treated with saline 2 ml/d, the C and E groups were treated with 2 ml saline containing amiodarone 100 mg×kg(-1)×d(-1). All rabbits were examined by echocardiogram at 12 weeks after operation, then anesthetized by sodium barbital, the left wedge ventricular preparations were cannulated and artery perfused by Tyrode's solution in vitro in the absence (Group A, B and C) and presence of AAP10 (500 nmol/L, Group D and E). The volume electrocardiogram, QT Interval, QRS interval, effective refractory period (ERP), the T-peak to T-end interval (T(p-e)), and ventricular tachycardia episodes induced by programmed stimulation were recorded. The T(p-e)/QT ratio was calculated. After perfusion, gap junctions protein connexin 43 (Cx43) expression was detected by Western blot and immunofluorescence.

RESULTSThe incidence of induced ventricular tachycardia episodes of group A, B, C, D, E was 0, 62.5%, 26.9%, 40.0%, 22.2% respectively. The incidence of induced ventricular tachycardia episodes of group E was less than group B. The T(p-e)/QT ratio in group B, C, D were greater than in group A. The T(p-e)/QT ratio of group E was less than group B. The myocardial Cx43 in the group B was down-regulated and disorganized compared to group A, up-regulated in group C and E compared to group B, up-regulated in group E compared to group D. The Cx43 in the heart of group D and E were well organized than in group B and C.

CONCLUSIONSThe artery perfused rabbits wedge preparations with healed myocardial infarction with high incidence of induced ventricular tachycardia episodes are good platform for ventricular arrhythmias research. Combined amiodarone and AAP10 use could decrease the T(p-e)/QT ratio and the incidence of induced ventricular tachycardia episodes. Amiodarone and AAP10 have synergistic effects on upregulating Cx43 and preventing ventricular arrhythmias in this rabbit model of healed myocardial infarction.

Amiodarone ; pharmacology ; therapeutic use ; Animals ; Anti-Arrhythmia Agents ; pharmacology ; therapeutic use ; Arrhythmias, Cardiac ; etiology ; Connexin 43 ; metabolism ; Male ; Myocardial Infarction ; drug therapy ; metabolism ; physiopathology ; Oligopeptides ; pharmacology ; therapeutic use ; Rabbits ; Treatment Outcome

AIMTo investigate the effects of imidapril (IMI) on effective refractory period (ERP) and sodium current (I(Na)) of myocytes in ventricular noninfarction zone of healed myocardial infarction (HMI) in rabbit models.

METHODSRabbits with left coronary artery ligation were prepared and IMI (0.625 mg x kg(-1) x d(-1), 8 weeks) was orally administered. The ERP and sodium current were recorded.

RESULTSThe ERP in HMI heart was prolonged. The ERP in IMI group was lower significantly than that of HMI group. The I(Na) density of myocyte in HMI ventricle decreased obviously. V 1/2 of steady state inactivation of I(Na) shifted to hyperpolarization, and time constant (tau) of recovery from inactivation in HMI ventricular myocyte was longer than that of sham ventricular myocyte. I(Na) density in IMI group increased markedly as compared with that of HMI group.

CONCLUSIONIMI was shown to reverse the abnormal prolongation of ERP in rabbit heart with the HMI and increase I(Na) density. It may be the mechanism of IMI preventing against antiarrhythmia in healed myocardical infarction.

Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Calcium Channels ; metabolism ; Female ; Heart Ventricles ; cytology ; Imidazolidines ; pharmacology ; Male ; Myocardial Infarction ; metabolism ; physiopathology ; Myocytes, Cardiac ; metabolism ; Rabbits ; Refractory Period, Electrophysiological ; drug effects

OBJECTIVETo explore the value of (18)F-FDG PET/CT in the diagnosis and treatment evaluation in patients with pretreatment or recurrent extranodular natural killer/T-cell lymphoma nasal type (ENTCL).

METHODS(18)F-FDG PET/CT images and clinical records of 35 cases (67 scans) of pathologically confirmed ENTCL treated in our hospital within the last 9 years were analyzed. The imaging characteristics of the upper aerodigestive tract (UAT) and the non-aerodigestive tract (NUAT) lesions were analyzed. Lesion distribution, clinical stages, SUVmax and patient survival data were compared between pretreatment and recurrent cases.

RESULTSs All the ENTCL lesions were hypermetabolic. The UAT lesions involved mainly the nasal cavity and pharynx, while the NUAT lesions may involve the lymph nodes and all the organs. UAT lesions were more common in pretreatment cases while NUAT lesions tended to increase in recurrent cases. The SUVmax of pretreatment and recurrent lesions were 10.4∓4.4 and 9.6∓5.2, and showed no significant difference among patients with different lesion distribution patterns, clinical stages, or treatment history. The tumor remission rate evaluated by PET/CT were higher in cases with an initial diagnosis than in those with recurrence [(89.5% (17/19) vs 33.3% (5/15), P<0.005)]. Cox regression analysis revealed no significant differences in the survival rates among patients with different treatment history, clinical stages, lesion distribution patterns, or SUVmax levels (P>0.05).

CONCLUSION(18)F-FDG PET/CT can sensitively detect the pretreatment or recurrent lesions in ENTCL patients and helps in accurate tumor staging and curative effect evaluation.

Fluorodeoxyglucose F18 ; Humans ; Lymphoma, Extranodal NK-T-Cell ; diagnostic imaging ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Positron Emission Tomography Computed Tomography