Streptomyces sp. strain PGPA39 alleviates salt stress and promotes growth of 'Micro Tom' tomato plants

AIMS

To identify an actinobacterial strain that can promote growth and alleviate salinity stress in tomato plants.

METHODS AND RESULTS

Actinobacteria were isolated from agricultural soil and screened for ACC deaminase activity, production of indole acetic acid (IAA), solubilization of tricalcium phosphate and sodium chloride (NaCl) salinity tolerance. Among the several strains tested, one strain designated PGPA39 exhibited higher IAA production, and phosphate solubilization in addition to ACC deaminase activity, and tolerance to 1 mol l(-1) NaCl. Strain PGPA39 was identified as a Streptomyces strain based on 16S rDNA sequence and designated Streptomyces sp. strain PGPA39. It promoted the growth of Arabidopsis seedlings in vitro as evidenced by a significant increase in plant biomass and number of lateral roots. Salinity stress-alleviating activity of PGPA39 was evaluated using 'Micro Tom' tomato plants with 180 mmol l(-1) NaCl stress under gnotobiotic condition. A significant increase in plant biomass and chlorophyll content and a reduction in leaf proline content were observed in PGPA39-inoculated tomato plants under salt stress compared with control and salt-stressed noninoculated plants.

CONCLUSIONS

Streptomyces sp. strain PGPA39 alleviated salt stress and promoted the growth of tomato plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows the potential of Streptomyces sp. strain PGPA39 in alleviating salinity stress in tomato plants and could be utilized for stress alleviation in crop plants under field conditions.

Cilostazol eliminates adverse smoking outcome in patients with drug-eluting stent implantation

BACKGROUND

The present study investigated whether cilostazol can eliminate adverse smoking outcome after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A total of 914 patients with successful drug-eluting stent (DES) implantation were randomly assigned to dual antiplatelet therapy (DAT; aspirin and clopidogrel, n=457) or to triple antiplatelet therapy (TAT; DAT with cilostazol, n=457). The effect of smoking on 2-year major adverse cardio/cerebrovascular events (MACCE) in both the TAT and DAT groups was evaluated. Total MACCE were not significantly different between the 2 anti-platelet regimens (9.8% in TAT vs. 11.4% in DAT groups, P=0.45), but the adverse effects of smoking on clinical outcome were different between DAT vs. TAT. Current smokers had a higher prevalence of MACCE than non-smokers in the DAT group (16.7% vs. 9.5%, P=0.04). In the TAT group, however, the adverse effect of smoking was abolished (9.2% vs. 10.1%, P=0.85). Regarding the effects of smoking on the antiplatelet effects of DAT or TAT, post-treatment platelet reactivity (in P2Y12 reaction units; PRU) in current smokers was not significantly lower than that in non-smokers in the DAT group, whereas, in the TAT group, it was significantly lower than that of non-smokers (189±88 vs. 216±89 PRU, P=0.01).

CONCLUSIONS

Adverse clinical effects of smoking may be eliminated by the addition of cilostazol to DAT after DES implantation. This may be due to the stimulation of cilostazol's antiplatelet effects by smoking.

Comparison of 9-month angiographic outcomes of Resolute zotarolimus-eluting and everolimus-eluting stents in a real world setting of coronary intervention in Korea

BACKGROUND

Clinical outcomes of new-generation drug-eluting stents (DES), Everolimus-eluting stent (EES) or Resolute zotarolimus-eluting stent (R-ZES), have been reported. However, angiographic follow-up data of new-generation DES are limited, especially in Asians. We investigated the angiographic and clinical outcomes of EES and R-ZES in a real-world setting of Korean patients.

METHODS

Angiographic and clinical outcomes of 679 patients (866 lesions) who had been treated with EES or R-ZES from Jun 2008 to May 2010 were evaluated. The primary analysis was to compare in-segment late loss at 9 months and the secondary analyses were to compare the clinical outcomes.

RESULTS

In-segment late loss at 9-month follow-up angiography was 0.23 ± 0.52 mm for EES and 0.29 ± 0.64 mm for R-ZES (p = 0.248). In addition, the rate of binary restenosis did not show between-group differences (5.8% vs. 6.8% for EES and R-ZES, respectively, p = 0.716). During a median follow-up of 33 months, there were no significant differences in Kaplan-Meier estimates of target lesion failure (TLF) (7.5% vs. 7.9% for EES and R-ZES, respectively, p = 0.578) and patient-oriented composite outcomes (POCO including all-cause death, any myocardial infarction, and any revascularization, 22.8% vs. 20.1%, p = 0.888). The adjusted hazard ratios for TLF and POCO were 0.875 (95% CI 0.427 - 1.793; p = 0.715) and 1.029 (95% CI 0.642 - 1.650; p = 0.904), respectively, for EES over R-ZES in the propensity score matched group analysis.

CONCLUSIONS

In Korean patients undergoing new-generation DES implantation for coronary artery disease, EES and R-ZES showed similar angiographic outcomes at 9 months and comparable clinical outcomes during 2.8 years of median follow-up.

Impact of anticoagulation on coronary flow in patients with non-ST elevation acute coronary syndrome

The effect of anticoagulation by heparin on patients with non-ST elevation acute coronary syndrome (NSTE-ACS), receiving early dual antiplatelet therapy, has not been fully evaluated. We classified 355 patients with NSTE-ACS according to the adequacy of anticoagulation (percentage of low activated partial thromboplastin time [APTT] level). The 6-hour APTT level was optimal in only 23.1% of the patients treated with unfractionated heparin. The rate of poor preprocedural coronary blood flow (thrombolysis in myocardial infarction grade <3, 39.1%, 30.5%, 30.3%, and 33.9% in the 100% low-, 99%∼50% low-, 49%∼1% low-, and 0% low-APTT group, respectively, P = .632) and bleeding events did not differ between the groups. Instead, in multivariate analysis, the diagnosis of myocardial infarction was the only independent predictor of poor coronary flow. For bleeding events, the usage of glycoprotein IIb/IIIa inhibitor appeared to be a sole risk factor. In conclusion, inadequate preprocedural anticoagulation was not associated with adverse outcomes in patients with NSTE-ACS treated with dual antiplatelet agents.

Prevalence and prognostic implication of non-calcified plaque in asymptomatic population with coronary artery calcium score of zero

Background and Objectives

Non-calcified plaque (NCP) identified by coronary CT angiography (CCTA) has been reported in up to 10% of individuals with coronary artery calcium score (CACS) of zero. However, clinical risk factors and the prognostic value of NCP in asymptomatic subjects with CACS of zero are unknown.

Subjects and Methods

The study population consisted of consecutive asymptomatic subjects (48±8 years, 57% men) who underwent CCTA from December 2005 to January 2008 as part of a general health evaluation.

Results

Among 4491 of overall asymptomatic individuals with CACS of zero, 313 subjects (7%) had NCP: 279 patients (6%) with non-obstructive and 34 (1%) with obstructive. In multivariable analyses, age, male gender, diabetes, hypertension, and dyslipidemia were significantly associated with presence of NCP (all p<0.05). During the median follow-up duration of 22 months (interquartile percentile: 18 to 28 months) of subjects with NCP (n=313) and age, gender, and CCTA date matched individuals without NCP (n=313), there was no clinical event including all-cause death nor composite outcome of cardiac death, myocardial infarct, unstable angina requiring hospitalization, and revascularization after 90 days from index CCTA in both groups.

Conclusion

In the largest series of asymptomatic individuals with CACS of zero undergoing CCTA, age, male gender, diabetes, hypertension, and dyslipidemia were independently associated with NCP. However, a future risk of exclusive NCP in asymptomatic subjects with CACS of zero was negligible.

Does a negative ergonovine provocation test truly predict freedom from variant angina?

Ergonovine provocation test is known to be very sensitive for diagnosing variant angina. The patient described in this study initially presented with atypical chest pain and underwent coronary angiography and ergonovine provocation tests, which were negative. The patient was subsequently prescribed a proton pump inhibitor and prokinetics for pain relief, but then presented with acute myocardial infarction and cardiogenic shock due to coronary artery vasospasm 5 years later. This case suggests that ergonovine provocation test generates false negative results, which can lead to unwanted outcomes. Even with a negative ergonovine provocation test, prescription of calcium channel blockers or nitrates should be considered in patients with a clinical history suggestive of variant angina.

Prognostic value of neutrophil to lymphocyte ratio in patients presenting with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

Atherosclerosis is an inflammatory process, and inflammatory biomarkers have been identified as useful predictors of clinical outcomes. The prognostic value of leukocyte count in patients with ST-segment elevation myocardial infarctions who undergo primary percutaneous coronary intervention is not clearly defined. In 325 patients with STEMIs treated with primary percutaneous coronary intervention, total and differential leukocyte counts, once at admission and 24 hours thereafter, were measured. The neutrophil/lymphocyte ratio (NLR) was calculated as the ratio of neutrophil count to lymphocyte count. The primary end point was all-cause death. Twenty-five patients (7.7%) died during follow-up (median 1,092 days, interquartile range 632 to 1,464). The total leukocyte count decreased (from 11,853 ± 3,946/μl to 11,245 ± 3,979/μl, p = 0.004) from baseline to 24 hours after admission. Patients who died had higher neutrophil counts (9,887 ± 5,417/μl vs 8,399 ± 3,639/μl, p = 0.061), lower lymphocyte counts (1,566 ± 786/μl vs 1,899 ± 770/μl, p = 0.039), and higher NLRs (8.58 ± 7.41 vs 5.51 ± 4.20, p = 0.001) at 24 hours after admission. Baseline leukocyte profile was not associated with outcomes. The best cut-off value of 24-hour NLR to predict mortality was 5.44 (area under the curve 0.72, 95% confidence interval [CI] 0.52 to 0.82). In multivariate analysis, a 24-hour NLR ≥5.44 was an independent predictor of mortality (hazard ratio 3.12, 95% CI 1.14 to 8.55), along with chronic kidney disease (hazard ratio 4.23, 95% CI 1.62 to 11.1) and the left ventricular ejection fraction (hazard ratio 0.94 for a 3% increase, 95% CI 0.76 to 0.93). In conclusion, NLR at 24 hours after admission can be used for risk stratification in patients with STEMIs who undergo primary PCI. Patients with STEMIs with 24-hour NLRs ≥5.44 are at increased risk for mortality and should receive more intensive treatment.

Comparison of a drug-eluting balloon first and then bare metal stent with a drug-eluting stent for treatment of de novo lesions: study protocol of a randomized controlled trial

Background

The use of a drug-eluting balloon for the treatment of de novo coronary artery lesions remains to be evaluated. A previous trial in patients with stable and unstable angina comparing a bare metal stent mounted on a drug-eluting balloon with a sirolimus-eluting stent failed to meet the prespecified non-inferiority criteria versus the sirolimus-eluting stent. The stent struts of a bare metal stent pre-mounted on a drug-eluting balloon may prevent the appropriate delivery of drugs to the vessel wall and may result in reduced efficacy. In the present study we will therefore evaluate the efficacy of a drug-eluting balloon for treating de novo coronary artery lesions using a strategy designed to uniformly deliver drug to the vessel with a bare metal stent.

Methods/Design

The Comparison of Drug-Eluting Balloon first study is a prospective, randomized, open-label trial designed to demonstrate the non-inferiority of first using a drug-eluting balloon (Sequent^® please; B. Braun, Melsungen, Germany) followed by a bare metal stent (Coroflex^® Blue; B. Braun) compared with using a drug-eluting stent (Resolute Integrity™; Boston Scientific, Natick, MA, USA) for de novo coronary artery lesions. The primary endpoint of the study is in-segment late loss at 9 months measured by quantitative coronary angiography. Secondary endpoints include angiographic findings such as angiographic success, device success, binary angiographic restenosis, and clinical outcomes such as procedural success, all-cause death, myocardial infarction, target vessel revascularization, target lesion revascularization, and stent thrombosis. A total of 180 patients will be enrolled in the study.

Discussion

The Comparison of Drug-Eluting Balloon first study will evaluate the clinical efficacy, angiographic outcomes and safety of a drug-eluting balloon first followed by a bare metal stent compared with a drug-eluting stent for the treatment of de novo coronary artery lesions.

Trial registration

Clinical Trials.gov: NCT01539603

Effect of tailored antiplatelet therapy on periprocedural myonecrosis in patients with diabetes mellitus (from the DM-Verify Now Trial)

We investigated whether additional platelet inhibition with a glycoprotein IIb/IIIa inhibitor would be beneficial in reducing the risk of periprocedural myocardial infarction (PMI) in diabetic patients with high residual platelet reactivity (HPR). Patients with diabetes mellitus were administered aspirin and clopidogrel at a 300-mg loading dose 1 day before the procedure, and the VerifyNow P2Y(12) assay was performed just before percutaneous coronary intervention. Patients with HPR, defined as a P2Y(12) reaction unit of ≥270 were randomly assigned to group A or control group C1. Patients without HPR were assigned to control group C2. Conventional anticoagulation with heparin was given to groups C1 and C2, and group A received additional abciximab treatment. Clinically relevant PMI was defined as any elevation in the biomarkers creatine kinase-MB isoenzyme and cardiac troponin I >3 times the upper normal limit measured 8, 16, or 24 hours after percutaneous coronary intervention. Of the patients, 47 and 51 were assigned to group A and C1; the clinical and procedural characteristics in the 2 groups were balanced. Of the 47 patients in group A and 51 patients in group C1, 9 (19%) and 9 (18%), respectively, experienced a PMI event according to the creatine kinase-MB cutoff (p = 1.00), and 27 in group A (57%) and 29 in group C1 (57%) experienced a PMI event according to the troponin I cutoff (p = 1.00). Five minor bleeding events, including small and localized hematomas, were observed immediately after the procedure (4 in group A and 1 in group C1). Only 1 major bleeding event, retroperitoneal hemorrhage, was observed in group A. The patients in group C2 had a PMI event rate (50% of 32 patients, p = 1.00) similar to that of group C1. In conclusion, additional platelet inhibition using a tailored approach and a point-of-care assay did not improve the periprocedural outcome in diabetic patients with HPR.

Cigarette smoking is paradoxically associated with low mortality risk after acute myocardial infarction

BACKGROUND

Cigarette smoking has been shown to be associated with a decreased risk of death after acute myocardial infarction (AMI), which is also known as the "smokers' paradox." This study aimed to investigate the relationship between smoking and all-cause mortality after AMI.

METHODS

We extracted the data of patients who were hospitalized for AMI between November 2005 and September 2010 from nationwide multicenter prospective registries in Korea.

RESULTS

Among a total of 29,199 patients with AMI, 10,251 (42.3%) were current smokers, and 14,006 (57.7%) were nonsmokers. Current smokers were younger, more likely to be male, and had lower frequencies of hypertension, diabetes mellitus, dyslipidemia, and previous history of ischemic heart disease than nonsmokers. The initial presentation was less severe in terms of hemodynamic status, and angiography showed less complex coronary involvement in smokers. The overall mortality rate was 5.4% for current smokers and 9.9% for nonsmokers (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.47-0.58; p < .001). The gap in risk was attenuated after multivariable adjustment but remained statistically significant (HR, 0.85; 95% CI, 0.76-0.95; p = .005). Propensity score matching corroborated the results of reduced mortality among current smokers (6.7% vs. 7.6%; p = .005).

CONCLUSIONS

In this study, in which the patients received up-to-date treatment options, smoking was associated with a 48% decrease in the risk of all-cause mortality at 1 year after AMI.

A randomized, prospective, two-center comparison of sirolimus-eluting stent and zotarolimus-eluting stent in acute ST-elevation myocardial infarction: the SEZE trial

BACKGROUND

The zotarolimus-eluting stent has shown larger in-stent late lumen loss compared to sirolimus-eluting stents in previous studies. However, this has not been thoroughly evaluated in ST elevation myocardial infarction.

METHODS

This was a prospective, randomized, controlled trial evaluating angiographic outcomes in patients presenting with ST elevation myocardial infarction, treated with zotarolimus-eluting stents or sirolimus-eluting stents. From March 2007 to February 2009, 122 patients were randomized to zotarolimus-eluting stents or sirolimus-eluting stents in a 1:1 fashion. The primary endpoint was 9-month in-stent late lumen loss confirmed by coronary angiography, and secondary endpoints were percent diameter stenosis, binary restenosis rate, major adverse cardiac events (a composite of cardiac death, non-fatal myocardial infarction, and target vessel revascularization), and late-acquired incomplete stent apposition.

RESULTS

Angiographic in-stent late lumen loss was significantly higher in the zotarolimus-eluting stent group compared to the sirolimus-eluting stent group ((0.49 ± 0.65) mm vs. (0.10 ± 0.46) mm, P = 0.001). Percent diameter stenosis at 9-month follow-up was also larger in the zotarolimus-eluting stent group ((30.0 ± 17.9)% vs. (17.6 ± 14.0)%, P < 0.001). In-segment analysis showed similar findings. There were no significant differences in binary restenosis rate, major adverse cardiac events, and late-acquired incomplete stent apposition.

CONCLUSIONS

Compared to sirolimus-eluting stents, the zotarolimus-eluting stent is associated with significantly higher in-stent late lumen loss at 9-month angiographic follow-up in the treatment of ST elevation myocardial infarction. Although there was no significant difference in 1-year clinical outcomes, the clinical implication of increased late lumen loss should be further studied.

Left ventricular thrombus and subsequent thromboembolism, comparison of anticoagulation, surgical removal, and antiplatelet agents

Left ventricular (LV) thrombus is one of the risk factors for systemic thromboembolism. The aims of this study were to compare the long-term clinical outcomes of LV thrombus using current therapeutics, anticoagulation, operative treatment, and antiplatelet agents and to identify independent predictors of systemic thromboembolism.

METHODS

We screened 86,374 patients for intracardiac thrombus in the electronic medical records and imaging databases. Records of 62 patients with LV thrombus, diagnosed between May 2003 to November 2011, were comprehensively reviewed regarding baseline characteristics, imaging data and thrombus outcomes, thromboembolic events and treatment complications by treatment group.

RESULTS

The majority (80.6%) had ischemic etiology. Systemic thromboembolism developed in 18 patients; 8 (45%) were post-treatment thromboembolisms while 10 events occurred before treatment began. No post-treatment thromboembolism occurred in the operative treatment group; in contrast, 7 post-treatment thromboembolisms occurred in anticoagulation group (17%) (Log rank p= 0.175). Independent predictors of post-treatment thromboembolism were dilated cardiomyopathy (HR 61.30, p= 0.001), previous cerebrovascular events (HR 7.06, p= 0.042), female gender (HR 7.11, p= 0.031), and echocardiographic left ventricular end-diastolic diameter (HR 1.15, p= 0.047).

CONCLUSIONS

In this study, the rate of post-treatment thromboembolism was not significantly different among the treatment groups; however, operative treatment tended towards less post-treatment thromboembolism than other treatment groups.

Cotreatment with darbepoetin and granulocyte colony-stimulating factor is efficient to recruit proangiogenic cell populations in patients with acute myocardial infarction

To determine whether newer combination cytokine treatment with granulocyte colony-stimulating factor (G-CSF) and darbepoetin can improve efficacy of stem cell therapy, we evaluated safety and peripheral blood stem/progenitor cell (PBSC) mobilizing effects of combination cytokine in comparison with G-CSF alone in patients with acute myocardial infarction (AMI). We randomized 60 patients with AMI into two groups under 2:1 ratio; combination treatment with darbepoetin and G-CSF (n = 41: Combicytokine group) and the G-CSF alone (n = 19: G-CSF group). After coronary angioplasty, G-CSF was treated for 3 days with dose of 10 μg/kg/day in both groups. Only in the combicytokine group, additional single intravenous injection of 4.5 μg/kg of darbepoetin was administrated immediate after coronary angioplasty. Combination cytokine treatment was well tolerated as was G-CSF alone. PBSCs were obtained by apheresis for intracoronary infusion after completion of cytokine treatment and were analyzed by flow cytometry. The purity of proangiogenic cells was higher in combination cytokine group than the G-CSF group. Specifically, proportion of CD34(+)/KDR(+) endothelial progenitor cells, CD3(+)/CD31(+) angiogenic T cells and Tie2(+)/CXCR4(+) cells in apheresis products were higher in the combicytokine group. These meant that the combicytokine treatment recruited PBSCs in higher purity and fewer unwanted inflammatory cells than G-CSF alone in apheresis products. Combination treatment with darbepoetin and G-CSF is safe and more efficient to mobilize and recruit proangiogenic cells than G-CSF alone in patients with AMI. (

TRIAL REGISTRATION

www.ClinicalTrials. gov identifier: NCT00501917).

Sex differences in management and mortality of patients with ST-elevation myocardial infarction (from the Korean Acute Myocardial Infarction National Registry)

There has been controversy over the disparity between men and women with regard to the management and prognosis of acute myocardial infarction. Analyzing nationwide multicenter prospective registries in Korea, the aim of this study was to determine whether female gender independently imposes a risk for mortality. Data from 14,253 patients who were hospitalized for ST-segment elevation myocardial infarction from November 2005 to September 2010 were extracted from registries. Compared to men, women were older (mean age 56 ± 12 vs 67 ± 10 years, p < 0.001), and female gender was associated with a higher frequency of co-morbidities, including hypertension, diabetes, and dyslipidemia. Women had longer pain-to-door time and more severe hemodynamic status than men. All-cause mortality rates were 13.6% in women and 7.0% in men at 1 year after the index admission (hazard ratio for women 2.01, 95% confidence interval 1.80 to 2.25, p < 0.001). The risk for death after ST-segment elevation myocardial infarction corresponded highly with age. Although the risk remained high after adjusting for age, further analyses adjusting for medical history, clinical performance, and hemodynamic status diminished the gender effect (hazard ratio 1.00, 95% confidence interval 0.86 to 1.17, p = 0.821). Propensity score matching, as a sensitivity analysis, corroborated the results. In conclusion, this study shows that women have a comparable risk for death after ST-segment elevation myocardial infarction as men. The gender effect was accounted for mostly by the women's older age, complex co-morbidities, and severe hemodynamic conditions at presentation.