Preparation of SnS2/MWCNTs chemically modified electrode and its electrochemical detection of H2O2.

Considering the importance of hydrogen peroxide (H2O2) rapid detection, a SnS2/MWCNTs composite was prepared by loading tin disulfide (SnS2) nanoparticles on a three-dimensional conductive network composed of multi-walled carbon nanotubes (MWCNTs). The obtained SnS2/MWCNTs composite was used as the modified material to prepare a chemically modified electrode (CME), which was used for the rapid detection of H2O2. The morphology and structure of the obtained samples were characterized and analyzed by scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy. The electrochemical performance of the modified electrode was researched by cyclic voltammetry, amperometric i-t curves, and AC impedance techniques. The results show that SnS2 nanoparticles with a size of about 33 nm are evenly dispersed on the surface of MWCNTs. The obtained SnS2/MWCNTs-CME has a strong current response to H2O2: it has a good linear relationship during the range of 0.248 ~ 16.423 mmol L-1, and its linear regression equation is Ipa (mA) = (-0.94 ± 0.05) × 10-2 + (- 0.43 ± 0.06) × 10-2c (mmol L-1) (R2 = 0.997) with a sensitivity of 87.84 µA mmol-1 L cm-2. The corresponding detection limit is 1.04 µmol L-1 (S/N = 3). At the same time, the SnS2/MWCNTs-CME has good selectivity, reproducibility, and stability. Graphical abstract Uniformly distributed SnS2/CNTs composite is used to prepare a chemically modified electrode for H2O2 detection. The prepared electrode has a strong electrochemical response to H2O2 due to the excellent conductivity and support of CNTs. And the SnS2/CNTs electrode shows high sensitivity and selectivity for the electrochemical detection of H2O2.

Catalpol decreases peroxynitrite formation and consequently exerts cardioprotective effects against ischemia/reperfusion insult.

CONTEXT: Peroxynitrite (ONOO(-)) formation triggers oxidative/nitrative stress and contributes to exacerbated myocardial ischemia/reperfusion (MI/R) injury. Catalpol, an iridoid glycoside, abundantly found in the roots of Rehmannia glutinosa L. that is included in the family Phrymaceae in the order Lamiales, endemic to China, was found to have neuroprotective effects. However, the effect of catalpol on MI/R injury has not been identified. OBJECTIVE: This study investigated whether catalpol attenuates oxidative/nitrative stress in acute MI/R. MATERIALS AND METHODS: Adult male rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion and were treated with saline, catalpol (5 mg/kg, i.p., 5 min before reperfusion) or catalpol plus wortmannin (15 µg/kg intraperitoneally injected 15 min before reperfusion). RESULTS: Pretreatment with catalpol significantly improved cardiac functions, reduced myocardial infarction, apoptosis and necrosis of cardiomyocytes after MI/R (all p < 0.05). Meanwhile, ONOO(-) formation was markedly reduced after catalpol treatment (3.01 ± 0.22 vs. 4.66 ± 0.53 pmol/mg protein in vehicle, p < 0.05). In addition, catalpol increased Akt and endothelial nitric oxide synthase phosphorylation, nitric oxide (NO) production, anti-oxidant capacity and reduced MI/R-induced inducible nitric oxide synthase expression and superoxide anion (·O(2)(-)) production in I/R hearts. PI3K inhibitor wortmannin not only blocked catalpol-induced Akt activation, but also attenuated all the beneficial effects of catalpol. Suppression of ONOO(-) formation by either catalpol or an ONOO(-) scavenger uric acid (5 mg/kg) reduced myocardial infarct size in MI/R rats. DISCUSSION AND CONCLUSION: In conclusion, catalpol affords cardioprotection against MI/R insult by attenuating ONOO(-) formation, which is attributable to increased physiological NO and decreased ·O(2)(-) production.

[Cause of in-hospital death among acute myocardial infarction patients undergoing primary percutaneous coronary intervention in Beijing].

OBJECTIVE: To analyze the cause of in-hospital death among acute myocardial infarction patients undergoing primary percutaneous coronary intervention (PPCI) in Beijing area to evoke better individualized preventive approach. METHODS: In-hospital mortality and causes were analyzed based on database from Beijing percutaneous coronary intervention registry study (BJPCI Registry) in 2010. RESULTS: A total of 4660 PPCI patients from 48 hospitals were included. In-hospital mortality was 2.4% (n = 110). Cardiogenic shock (39.1%, 43/110), mechanical complications (28.2%, 31/110) and intervention-related complications [28.2%, 31/110: procedure related (n = 28), drug related (n = 3)] were the leading causes of in-hospital death. Five deaths was attributed to comorbidity related reason (4.5%, 5/110). The in-hospital mortality had no significant difference among hospitals of different grade or total annual PCI (all P > 0.05). In-hospital mortality was slightly higher in hospital with annual PPCI < 300 than in hospitals with annual PPCI ≥ 300 (2.9% vs. 1.8%, P < 0.05). CONCLUSION: Cardiogenic shock, mechanical complications and intervention-related complications are the main causes of in-hospital death among acute myocardial infarction patients receiving PPCI.

[Effects of rapamycin-loaded poly(lactic-co-glycolic) acid nanoparticles on distribution of cell cycle, expression of p27 protein, and proliferation of human umbilical arterial vascular smooth muscle cell in vitro].

OBJECTIVE: To evaluate the effects of rapamycin (RPM)-loaded poly (lactic-co- glycolic) acid (PLGA) nanoparticles (NPs) on the proliferation, distribution of cell cycle, and expression of p27 protein in human umbilical arterial vascular smooth muscle cell (HUASMC) in vitro. METHODS: The primarily culture model of HUASMC was successfully established by explant-attached method in vitro. The cells were administrated with different doses of RPM, and RPM-PLGA NPs were observed as treat groups compared with PLGA NPs and M231-SMGs medium cultured group. The effect of RPM-PLGA NPs on proliferation of HUASMC was assessed using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) colorimetry method. The influences of RPM-PLGA NPs on the cell cycle and cellular growth kinetics of HUASMCs were tested by flow cytometry. The effect of RPM-PLGA NPs on the expression of p27 protein of HUASMCs was assessed through an immunohistochemical method. RESULTS: Compared with the control group, the proliferation of HUASMCs was inhibited by 50 microg/L and higher concentration of RPM-PLGA NPs in a dose-dependent manner (P < 0.05). The numbers of cells entering cell cycle of S/G2/M phases were significantly lower in RPM-PLGA NPs and RPM treated groups. Histologically, the expression of p27 were up-regulated in 500 microg/L RPM-PLGA NPs and 100 microg/L RPM treated group (all P < 0.01 ) when compared with the control group. CONCLUSIONS: RPM-PLGA NPs has a similar effects as RPM in inhibiting the growth of in vitro cultured HUASMC. It can remarkably suppress the expression of in vitro cultured HUASMC p27 protein, arrest its cell cycle at G1/S phase, and inhibit its proliferation.

[Rapamycin-loaded poly (lactic-co-glycolic) acid nanoparticles for intraarterial local drug delivery: preparation, characterization, and in vitro/in vivo release].

OBJECTIVE: To sought to engineer and characterize a biodegradable nanoparticles (NPs) containing rapamycin which use poly (lactic-co-glycolic) acid (PLGA) as the carrier matrix and to assess its in vivo release characteristics by local drug delivery system intravascularly. METHODS: Rapamycin-loaded PLGA NPs were prepared by an emulsification/solvent evaporation technique, and NPs size distribution was assessed by submicro laser defractometer. The particle morphology was observed by scanning electron microscopy. In vitro release from the NPs was performed in TE buffer at 37 degrees C under rotation utilizing double-chamber diffusion cells on a shake stander. In vivo NPs intravascular local delivery were performed by DISPATCH catheter in New Zealand rabbit abdominal aorta and Chinese experimental mini-pigs coronary artery models. RESULTS: Biodegradable rapamycin loaded PLGA NPs were constructed successfully by emulsification solvent-evaporation technique. The diameter of rapamycin-PLGA NPs was around 246.8 nm with very narrow size distribution, and rapamycin-NPs showed good spherical shape with smooth uniform surface. Rapamycin loaded in NPs were around was 19.42%. Encapsulation efficiency of drug was over 77.53%. The in vitro release of rapamycin from NPs showed that 75% of the drug was sustained released over 2 weeks and controlled release in a linear pattern. After a single 10 minutes infusion of rapamycin-PLGA NPs suspension (5 mg/ml) under 20.27 kPa through DISPATCH catherter in vivo, the mean rapamycin levels at 7 day and 14 day were (2.438 +/- 0.439) and (0.529 +/- 0.144) microg/mg of the dry-weight of the artery segments (2 cm) which local delivery were administrated. CONCLUSIONS: PLGA NPs controlled drug delivery system for intraarterial local anti-proliferative drug delivery can potentially improve local drug concentration and prolong drug residence time in animal model in vivo. It should be appropriate for further study of its therapy efficiency in human.

Correlation Analysis between Traditional Chinese Medicine Syndromes and Gastrointestinal Bleeding after Percutaneous Coronary Intervention.

OBJECTIVE: To explore the characters of traditional Chinese medicine (TCM) syndromes after percutaneous coronary intervention (PCI) and to provide syndrome study theoretical evidence for TCM differentiation treatment after PCI through retrospective study. METHODS: Patients with coronary heart disease (CHD) who underwent PCI in Cardiovascular Intervention Center of Wangjing Hospital during Dec. 2012 to Dec. 2014 and met the inclusion criteria were enrolled. Retrospective study was then conducted based on patients' clinical document and angiography data to explore the distribution pattern of TCM syndromes. RESULTS: 801 patients were recruited in the study. TCM syndromes in descending order of their incidence were Qi deficiency and blood stasis syndrome, heart blood stasis syndrome, Qi and Yin deficiency syndrome, phlegm and blood stasis syndrome, Qi stagnation and blood stasis syndrome, Yang asthenia syndrome, heart and kidney yin deficiency syndrome to cold congeal, and blood stasis syndrome in a more to less order. Qi deficiency and blood stasis syndrome was in the most (occurring in 298 patients, 37.20%); Qi and Yin deficiency syndrome occurred in 163 patients (20.35%); heart blood stasis syndrome was shown in 126 patients (15.73%); phlegm and blood stasis syndrome was shown in 95 patients (11.86%). CONCLUSION: Qi deficiency and blood stasis syndrome was closely associated with post-PCI bleeding, implying that this syndrome might serve as a powerful predictor of GI bleeding as well as a potential supplement to the current predicting and scoring system of bleeding such as CRUSADE.

A Randomized Double-Blind Placebo-Controlled Trial to Evaluate Prophylactic Effect of Traditional Chinese Medicine Supplementing Qi and Hemostasis Formula on Gastrointestinal Bleeding after Percutaneous Coronary Intervention in Patients at High Risks.

OBJECTIVE: To evaluate the clinical efficacy of traditional Chinese medicine (TCM) supplementing Qi and hemostasis formula on gastrointestinal (GI) bleeding after percutaneous coronary intervention (PCI) and thus find out the optimal therapeutic regimen to reduce incidence of GI bleeding without increase of major adverse cardiovascular events (MACEs). METHODS: In the randomized, double-blinded, controlled trial, 117 participants who underwent PCI were enrolled and evenly distributed into treatment arm (59) and control arm (58). Numerous end points were assessed including the primary endpoint of GI bleeding and MACEs and secondary endpoint of thromboelastogram (TEG) (mainly MAadp, inhibition of ADP, and inhibition of AA) and TCM syndrome score during the follow-up phase of 90 days. RESULTS: Incidence of bleeding including GI bleeding and MACE did not differ significantly between two arms (28.82% in treatment arm versus 24.44% in control). However, on both days 30 and 90, TCM treatment remarkably reduced the TCM syndrome total score with notable alteration (P<0.05) except for some parameters such as pulse manifestation. When it came to TEG, however, MAADP increased significantly on day 30 in control arm, accompanied by a notable descending in inhibition rate of ADP pathway (both P<0.01). CONCLUSION: (1) Supplementing Qi and hemostasis formula is equal to Pantoprazole Sodium Enteric-Coated Capsule in hemostasis and gastric mucosal protection; (2) supplementing Qi and hemostasis formula is superior to Pantoprazole Sodium Enteric-Coated Capsule in improving TCM syndrome manifestation possibly through the multitarget mechanism; (3) interference on clopidogrel of supplementing Qi and hemostasis formula might be much less than Pantoprazole Sodium Enteric-Coated Capsule due to the potential CYP450-independent mechanism. This trial is registered with ChiCTR1800014485.

[Myocardial blush grade, ST-segment elevation resolution and prognosis in acute myocardial infarction patients with or without diabetes mellitus post primary percutaneous coronary intervention].

OBJECTIVES: To investigated the prognosis of primary percutaneous coronary intervention (PCI) in acute myocardial infarction patients with or without diabetes mellitus (DM) in terms of myocardial blush grade (MBG) and ST-segment elevation resolution (STR). METHODS: MBG and STR were measured in AMI patients with (n = 95) and without (n = 192) diabetes mellitus after successful primary PCI. RESULTS: Post-procedural TIMI grade 3 flow (>95%) were similar between two groups. Compared to non-DM patients, DM patients were more likely to have absent myocardial perfusion (MBG 0/1, 56.0% vs. 41.1%, P = 0.019) and absent STR (43.2% vs. 30.7%, P = 0.038). MACE rate was also higher in DM patients than that in non-DM patients during follow-up (27.4% vs. 16.1%, P = 0.025). Multivariate analysis showed DM was an independently factor related to the risk of poor prognosis (RR 1.83, 95% CI 1.04 - 3.36], P = 0.01). CONCLUSION: Despite similar TIMI-3 flow after primary PCI, DM patients are more likely to have abnormal myocardial perfusion as assessed by both incomplete STR and reduced MBG and poor prognosis compared to non-DM patients. Poor prognosis in DM patients with AMI post PCI might be related to more disturbed micro-vascular perfusion.

[Early ST resolution after successful primary PCI is related to a favorable outcome in ST elevated AMI patients].

OBJECTIVE: To analyze the relationship between the early ST resolution magnitude and TIMI flow, MACE and the cardiac function in ST elevated AMI (STEMI) patients after successful primary PCI. METHODS: A total of 120 consecutive patients with STEMI underwent primary PCI within 12 hours after the onset of chest pain were enrolled in this study, the ST segment resolution was calculated and the patients were divided into group A (n = 81, Sigma STE resolved > or = 50%) and group B (n = 39, Sigma STE resolved < 50%). TIMI flow after PCI, clinical events up to 30 days post PCI and cardiac function 30 days post PCI were assessed. RESULTS: LVEF was higher in group A than that of group B (58.6% +/- 7.1% vs. 50.5% +/- 7.1%, P < 0.05). There are fewer patients with Killip III and IV in group A than in group B (1.2% vs. 12.8%, P < 0.05). The incidence of in-hospital MACE was also significantly less in group A than in group B (0 vs. 7.7%, P < 0.001). As expected, there were more patients with TIMI 3 flow (95.1% vs. 79.5%, P < 0.05) and fewer TIMI 2 (4.9% vs. 20.5%, P < 0.05) flow post PCI in group A than in group B and all 3 patients with MACE were group B patients with TIMI 2 flow. CONCLUSION: Early ST resolution post PCI represents improved myocardial perfusion and function and is related to a favorable clinical outcome in STEMI patients.