ABSTRACT
Objective:To identify the method to reduce X-ray exposure during ablation of atrial fibrillation (AF) by comparing the cryoballoon (CRYO) ablation and remote magnetic navigation (RMN) ablation.Methods:A retrospective analysis was conducted on 144 patients undergoing CRYO ablation (CRYO group) and 121 patients undergoing RMN ablation (RMN group) in our hospital. Entrance surface doses at reference points online, exposure time during procedure and outcomes were analyzed for different types of patients.Results:Compared with the RMN group, the procedure time for the CRYO group significantly decreased [(165.0±23.6), (97.8±18.4) min, t=26.05, P<0.001]. However, the entrance surface dose value [(232.3±130.7), (669.0±387.5) mGy, Z=-12.29, P<0.001] and X-ray exposure time [(8.1±3.1), (23.4±6.2) min, t=-24.57, P<0.001] increased significantly for the CRYO group. No significant difference was found between the two groups in the proportion of maintaining sinus rhythm during follow-up of patients (71.9%, 75.7%, P=0.618). Multiple regression analysis showed that obese patients, patients with non-paroxysmal AF and patients with variant pulmonary veins were associated with an increase in entrance surface dose values in the CRYO group ( t=5.47, 2.23, 3.39, P<0.05). The X-ray exposure time for the three types patients above in the CRYO group also increased ( t=2.87, 3.86, 3.25, P<0.05) in the CRYO group. However, only obese patients in the RMN group had an increase in entrance surface dose value ( Z=-4.15, P<0.001) and no increase in exposure time. For the three types of patients above, there was no significant difference in proportion of maintaining sinus rhythm between the CRYO group and the RMN group during follow-up ( P>0.05). Conclusions:Compared with RMN ablation, the radiation exposure of CRYO AF ablation significantly increased, especially in obese patients, patients with non-paroxysmal AF and patients with pulmonary veins variation. The use of RMN for these types of patients may reduce the radiation exposure without affecting the procedure outcomes.
ABSTRACT
Objective:To compare the differences of fluoroscopy time and dose between HIS bundle pacing and right ventricle apex pacing.Methods:This study includes thirty patients undergoing HIS bundle pacing (HIS group) and 32 patients undergoing right ventricular apex pacing (RVA group). The fluoroscopy time and cumulative dose (CD) to patients during surgery were recorded and analyzed.Results:The operation time for patients in HIS group and RVA group were (76.8±13.1) and (66.0±10.8) min ( t=3.386, P<0.001), respectively. The fluoroscopy time was (698.2±113.7) and (293.3±63.9) s ( t=14.709, P<0.001) and the CD were (391.3±70.0) and (162.3±40.5) mGy ( t=13.694, P<0.001) in HBP group and RVA group, respectively. In comparison, the fluoroscopy time and CD for HIS bundle electrode implantation were (501.2±112.3) s and (279.9±65.0) mGy, respectively, significantly higher than in the case of RVA, where the values were (103.4±30.6) s and (57.3±13.8) mGy ( t=15.864, Z=-6.524, P<0.001). Conclusions:Compared with right ventricular apical pacing, the HIS bundle pacing takes longer operation time, leading to higher radiation dose, which should be prudently selected.
ABSTRACT
Objective@#To investigate the impact of n-3 polyunsaturated fatty acid (n-3 PUFA) on function and expression of store-operated calcium channels (SOCC) in coronary artery smooth muscle cells (SMC) derived from diabetic rat.@*Methods@#A total of 180 healthy male Sprague-Dawley (SD) rats were randomly divided into normal group (N, n=45), placebo-treated diabetic group (D, n=45), lose dose n-3 PUFA treated diabetic group (DL, n=45) and high dose n-3 PUFAs treated diabetic group (DH, n=45). Streptozotocin-induced diabetic rat animal model was established by two consecutive intraperitoneal injections. After modeling, rats in group DL and DH were treated with 10 mg·kg-1·d-1 and 50 mg·kg-1·d-1 n-3 PUFAs respectively per gavage for eight weeks. After eight weeks, rat coronary artery SMC was isolated by enzyme digestion. Changes of cytosolic calcium concentration in coronary artery SMC were examined by calcium fluorescence imaging technique, coronary artery tension was detected by myograph system, and protein expressions of SOCC on coronary artery SMC were measured by Western blot.@*Results@#SOCC induced ΔF340/F380 of group N, D, DL and DH were 0.425±0.023, 0.838±0.037, 0.342±0.052 and 0.364±0.045 respectively, which was significantly lower in group N, DL, DH than in group D (P<0.05). SOCC induced changes of tensions were 0.94±0.09, 1.95±0.18, 1.35±0.24 and 1.01±0.18 in the group N, D, DL and DH, respectively, which was significantly lower in group N and DH than in group D (P<0.05). Protein expressions of STIM1, Orai1 and TRPC1 were significantly higher in diabetic rat coronary SMC than in group N (P<0.05). STIM1 protein expressions were significantly lower in group DL and DH than in group D, and Orai1 and TRPC1 protein expressions were similar among group.@*Conclusions@#Coronary artery tension, cytosolic calcium concentration and protein expressions of SOCC are higher in diabetic rat coronary artery SMC when compared with normal rats. n-3 PUFA intervention could downregulate the protein expression of SOCC, reduce cytosolic calcium concentration and coronary artery tension, and is protective to the diabetic injury in coronary artery.
ABSTRACT
OBJECTIVE： To prepare insoluble anti-tumor drug-loading polymer micelles， and to increase inhibitive effect of insoluble anti-tumor drug. METHODS： Chitosan （CSO） and stearic acid （SA） were used to prepare blank micelles （CSO-SA）， then modified with mPEG and folic acid （FA） to prepare PEG-CSO-SA and FA-PEG-CSO-SA. Characteristic functional groups of CSO-SA， PEG-CSO-SA and FA-PEG-CSO-SA were detected by infrared spectroscopy. The morphology of micelles was observed by transmission electron microscopy. The particle size and Zeta potential of micelles were measured by laser particle size analyzer. Osthole （OST） was used as the model drug and drug-loading micelles （FA-PEG-CSO-SA/OST） were prepared by dialysis. MTT assay was used to detect the inhibitory rate of FA-PEG-CSO-SA， OST solution and FA-PEG-CSO-SA/OST to human liver cancer cell HepG2. Half inhibitory concentration （IC50） was calculated. RESULTS： FA-PEG-CSO-SA was successfully prepared. CSO-SA， PEG-CSO-SA， FA-PEG-CSO-SA were oval in shape； particle sizes were （96.01±5.99）， （112.93±1.06）， （216.01±4.76） nm （n＝3） and Zeta potentials were （39.30±1.75）， （38.03±2.91）， （15.17±2.10） mV （n＝3）， respectively. Encapsulation efficiency and drug-loading amount of OST in FA-PEG-CSO-SA were （84.47±2.07）％ and （16.01±0.90）％ （n＝3）， respectively. The inhibition rates of FA-PEG-CSO-SA to HepG2 cells were＜20％. IC50 of OST solution and FA-PEG-CSO-SA/OST to HepG2 cells were （62.08±5.21）， （27.49±0.50） μg/mL （n＝3）， respectively. CONCLUSIONS： Prepared FA-PEG-CSO-SA can significantly increase inhibitive effect of insoluble drug OST to HepG2 cells， and it is expected to become a new anti-tumor drug carrier.
ABSTRACT
OBJECTIVE:To prepare Baicalin monolithic osmotic pump tablets and investigate its in vitro drug release behavior. METHODS:Using accumulative release rate as evaluation index,baicalin solid dispersion was prepared to improve solubility,sin-gle factor test and orthogonal test were used to optimize preparation technology(the amount of penetrating agent and pore-forming agent,weight gaining of coating film) of monolithic osmotic pump tablets using baicalin solid dispersion as intermediate. Release rate and mechanism of samples prepared by optimized technology were investigated in 3 kinds of release medium (water,0.1 mol/L HCl,simulated gastric fluid). RESULTS:The optimal preparation technology was that penetrating agent sodium chloride was 30 mg;pore-forming agent polyethylene glycol 400 was 20% amount of excipient cellulose acetate;weight gaining of coating film was 2%. RSD of 12 h accumulative release rate was 1.06%(n=3)for 3 batches of Baicalin monolithic osmotic pump tablets pre-pared by optimized technology. 12 h accumulative release rate of them in 3 kinds of medium were similar to each other,being all more than 80%. Release equation was in line with zero-order drug release model (r=0.9985). CONCLUSIONS:Prepared Ba-icalin monolithic osmotic pump tablets after optimization can release drug at controlled rate.
ABSTRACT
Objective To investigate the effects ofdocosahexenoic acid (DHA) on large conductance Ca2+-activated K+ (BK) channels in normal retinal artery smooth muscle cells (RASMCs).Methods Cultured human RASMCs (6 th-8 th generations) were used to patch clamp experiment.The open probabihties (NP0) in BK channels with different concentrations (0.0,1.0,3.0,5.0,7.5,10.0 μmol/L) of DHA were recorded by patch clamp technique in single channel configuration.RASMCs were intervened by different concentrations (0.0,1.0,5.0 μmol/L) of DHA as control group,low and high doses of DHA groups,respectively.The protein expressions of β subunit of BK channels in RASMCs from three groups were measured by Western blot.Results The NP0 of BK channels were 0.044 4±0.001 2,0.081 2±0.004 2,0.209 0±0.006 1,0.310 5±0.005 3,0.465 0±0.007 8 and 0.497 7±0.014 5 with perfusate of 0.0,1.0,3.0,5.0,7.5,10.0 μtmol/L DHA.DHA activated BK channels in a dose-dependent manner (F=2.621,P＜0.05).There was no significant difference in the protein expression of control group,low and high doses of DHA groups (F=1 1.657,P＞0.05).Conclusion DHA can directly activate BK channels,no increasing in subunit expression of BK channels.
ABSTRACT
Background Diabetic retinopathy (DR) is a common microvascular complications of the retina,retinal vascular smooth muscle cells of large conductance calcium-activated potassium channels (BK) is a major factor in regulating vasomotor and hemodynamic.Currently,functional changes of BK channel in retinal artery smooth muscle cells (RASMCs) and its role in DR were rarely reported.Objective This study was to investigate the early vascular damage mechanisms in DR by detecting the changes of BK channels current,calcium concentration and open probability (NP0) of BK channel with different calcium concentration in RASMCs of normal and diabetic rats.Method Fifty SPF SD 8-12 weeks old rats were randomly divided into normal control group and diabetic model group.Forty diabetic rats was intraperitoneally injected with 60 mg/kg streptozotocin to form type 1 diabetic model,10 rats (the normal control group) were injected sodium citrate solution with the same manner.Fluorescent probe was applied to detect calcium concentration in rat RASMCs;RASMCs were isolated by using enzyme digestion,and BK-channel electric currents and calcium concentrations in the RASMCs were measured by whole-cell patch clamp technique and fluorescence assay,respectively.The NP0 of BK channel was measured by single patch clamp technique.Results Diabetic models were successfully established in 36 rats with the success rate 90％.When stimulation voltage is greater than 60 mV,the current density of BK channel in RASMCs of diabetic model group decreased;when stimulating voltage was 100 mV,the BK channel currents of RASMCs in the normal control group and diabetic model group were (100±23) PA/PF and (50 ± 7) PA/PF,the difference was statistically significant (t =19.80,P ＜ 0.05).After adding specific BK channel blocker African scorpion toxin 100 nmol,the BK channel current in the normal control group significantly reduced,and that in the diabetes model group was not significantly changed;the calcium ion concentrations in RASMCs were (123±11)nmol/L and (255± 10)nmol/L in the normal control group and diabetic model group,the difference was statistically significant (t =32.50,P＜0.05).When stimulation voltage was 60 mV,with increasing calcium ion concentration,the NP0 of BK channel increased (F =15.28,P＜0.05).Conclusions The electric current and NP0 of BK-channel are obviously reduced and the calcium concentration is evidently elevated in RASMCs of diabetic rats,suggesting that the abnormal of BK-channel is probably one of the important causes of retinal artery abnormal contraction in diabetic rats.
ABSTRACT
Objective To investigate the optimal condition for transforming alkanna tinctoria pigment into shikonin. Methods Transformation rate of shikonin served as index. Transformation temperature, time, ratio of 2% NaOH to alkanna tinctoria pigment (v/w) was optimized. Results With ratio of 2% NaOH to alkanna tinctoria pigment being 4.5 mL·mg-1, temperature 35℃ and the reaction time 4 h, the transformation rate reached the highest, and the average transformation rate was 64.86%. Conclusion This method is easy and simple, and suitable for industrialized production.
ABSTRACT
Objective To compare the X-ray radiation dose from atrial fibrillation (AF) ablation guided by magnetic navigation system (MNS) and manual procedure (CON).Methods 94 AF patients were randomly divided into MNS group (34 cases) and CON group(60 cases).The dose area product (DAP),cumulative radiation dose (CD),fluoroscopy time of patients,the X-ray exposure time and dose of operators were recorded and analyzed.Results The results from the patients in MNS group and CON group were CD values (0.54 ±0.45) and (1.61 ±0.89) Gy (t =2.44,P ＜0.05),DAP values (46.86 ±27.09) and (139.71 ±76.69) Gy·cm2(t =3.89,P ＜0.05) and fluoroscopy time (15.60 ±7.52) and (39.50 ± 8.82) min (t =1.96,P ＜ 0.05),respectively.The X-ray exposure dose in both groups were (22.68 ± 6.87) and (62.74 ± 20.92) μSv (t =2.02,P ＜ 0.05) for operation doctor (19.38 ± 5.64) and (49.42 ± 10.67) μ Sv (t =3.58,P ＜ 0.05) for operation assistant and (18.98 ± 4.99) and (47.77 ± 13.65) μ Sv (t =3.17,P ＜ 0.05) for nurse,respectively.The X-ray exposure time experienced in both groups were (11.48 ±7.59) and (30.50 ±14.82) min (t =2.75,P ＜0.05) for operation doctor,(8.96 ±5.88) and (24.49 ±9.09) min (t =4.20,P ＜0.05) for operation assistant and (8.33 ±6.35) and (22.99 ± 13.36) min(t =2.76,P ＜ 0.05) for nurse,respectively.Conclusions Compared with manual procedure,the MNS applied in AF ablation has the potential to decrease X-ray exposure dose.
ABSTRACT
<p><b>OBJECTIVE</b>This review focuses on the role of the large conductance calcium-activated potassium (BKCa) channels in diabetic vascular complications.</p><p><b>DATA SOURCES</b>Relevant articles published in English or Chinese from 1981 to present were selected from PubMed. The search terms were "BKCa channels" and "diabetes". Important references from selected articles were also retrieved.</p><p><b>STUDY SELECTION</b>Articles regarding the role of BKCa channels in diabetic vascular complications and relevant mechanisms were selected.</p><p><b>RESULTS</b>The BKCa channels are abundantly expressed in vascular smooth cells and play an important role in regulation of vascular tone. Multiple studies indicated that the expression and function of BKCa channels are altered by different mechanisms in diabetic vascular diseases such as coronary arterial disease, cerebral arterial disease, and diabetic retinopathy.</p><p><b>CONCLUSION</b>BKCa channels may play an important role in diabetic vascular complications and may be an effective therapeutic target for relieving and reducing the burden of diabetic vascular complications.</p>
Subject(s)
Humans , Cerebral Arterial Diseases , Metabolism , Coronary Artery Disease , Diabetic Angiopathies , Metabolism , Diabetic Retinopathy , Metabolism , Large-Conductance Calcium-Activated Potassium Channels , MetabolismABSTRACT
miRNAs (microRNAs) are small RNA which regulate gene expressions at the post-transcriptional level.Recently studies have suggested that miRNA is associated with the development of diabetes mellitus and its complications.This artcle reviews the regulation of miRNA in diabetes mellitus and its cardiovascular complications,and the biomarkers' value and application of miRNA in the treatment of diabetes mellitus,aiming to develop new insight for the diagnosis and treatment of diabetes mellitus.
ABSTRACT
Objective To evaluate the role of real-time three-dimensional transesophageal echocardiography(RT3D-TEE) in non-valvular atrial fibrillation with left atrial appendage(LAA) stunning after catheter ablation.Methods Clinical and echocardiographic variables were analyzed by univariate regression in order to investigate the relationship between the group of LAA stunning and others in 28 patients after catheter ablation.Results Univariate analysis revealed difference in persisting time of atrial fibrillation[(16.4 ± 11.6)weeks vs (21.3 ± 18.6) weeks,P ＜0.05],left atrial diameter[(43.4 ± 8.3) mm vs (47.6 ± 5.9) mm,P ＜0.05 ],left atrial emptying fraction (0.38 ± 0.04 vs 0.30 ± 0.09,P ＜0.05).LAA emptying fraction based on three-dimensional volume measurements had significant difference (0.20 ± 0.03 vs 0.12 ± 0.02,P ＜ 0.001) between the group of LAA stunning and other cases.Conclusions LAA ejection fraction calculation by RT3D-TEE is feasible and more accurate than by clinical and other echocardiographic in LAA stunning after ablaton of atrial fibrillation.
ABSTRACT
Objective To investigate the effects of docosahexaenoic acid (DHA) on action potential (AP)and transient outward potassium channel (Ito) in rat ventricular myocytes in order to evaluate the anti-arrhythmia mechanism of DHA. Method The rat ventricular myocytes were isolated by using enzyme digestion method. AP and Ito of individual ventricular myocyte were recorded by using patch-clamp technique in whole-cell configuration at room temperature. The effects of DHA on AP and Ito were observed when it was applied in 0 μmol/L, 20 μmol/L, 40 μmol/L, 60 μmol/L, 80 μmol/L, 100 μmol/L and 120μmol/L separaterly. Results The 25%,50% and 90% of action potential duration (APD25, APD50 and APD90) were gradually prolonged with the escalation of concentration of DHA ( P ＜ 0.05, n= 20). The effects of DHA of different concentrations on AP maximal velocity (Vmax), AP amplitude (APA) and AP overshoot (OS) did not produce significantly different results (P ＞ 0.05, n= 20). The degree of blockade of Ito was concentration-dependent as different concentrations of DHA were applied, and as the concentration of DHA was escalated, the I-V curves went downwards, the stably inactivated curves shifted to the lift, and the time taken for recovery from inactivation prolonged ( P ＜ 0.05, n =20). However, the different concentrations of DHA did not produce different effects on stably activated curves ( P＞ 0.05). The Itos were blocked to (2.61 ± 0.26)%, (21.79±4.85)%, (63.11 ± 6.57)%, 75.52±7.26 ) %, (81.82 ± 7.63) % and (84.33 ± 8.25) % by the above given concentrations of DHA respectively under given potential equaling to + 70 mV( P ＜ 0.05, n = 20), and the half-effect concentration (EC50) of DHA on Ito was(49.11±2.68) umol/L. Conclusions The effects of DHA on APD and Ito may be one of the anti-arrhythmia mechanism of DHA.