Root photosynthesis prevents hypoxia in the epiphytic orchid Phalaenopsis.

Orchids (Phalaenopsis spp.) growing in tropical and subtropical regions are epiphytes. As such, they grow on trees with the root system utilised to anchor themselves to tree branches. These roots are highly specialised, display a large diameter and are often green, suggesting the ability to carry out photosynthesis. However, the role of photosynthesis in orchid roots is controversial. Orchids that are leafless can photosynthesise in their roots, thus indicating that some orchid roots carry out photosynthesis in a similar manner to leaves. However, the primary site of photosynthesis in orchids are in their leaves, and the roots of epiphytic orchids may mostly conduct internal refixation of respiratory CO2 . Besides contributing to the overall carbon metabolism of orchid plants, oxygen produced through root photosynthesis may also be important by alleviating potential root hypoxia. The bulky tissue of most epiphytic orchid roots suggests that oxygen diffusion in these roots can be limited. Here, we demonstrate that the bulky roots of a widely commercially cultivated orchid belonging to the genus Phalaenopsis are hypoxic in the dark. These roots are photosynthetically active and produce oxygen when exposed to light, thus mitigating root hypoxia.

Biochar as a soil amendment in the tree establishment phase: What are the consequences for tree physiology, soil quality and carbon sequestration?

Trees play a pivotal role in the urban environment alleviating the negative impacts of urbanization, and for this reason, local governments have promoted strongly tree planting policies. However, poor soil quality and neglect tree maintenance (e.g., irrigation and fertilization) can seriously mine the plant health status during the tree establishment phase. The use of biochar to provide long-lasting C to the soil and, at the same time, improving soil properties (e.g., improved water holding capacity), soil enzymes activities and NPK concentrations, is a promising research field. Therefore, with a two-step experiment, the study aimed to assay the physiological responses of a commonly used urban tree species (Tilia × europaea L.) to 1.5 % (w/w) biochar amendment (B), and secondly, to assess the ability of trees, grown in biochar amended soil, to tolerate a period of drought. Biochar amendment increased P and K availability in the soil, resulting in higher P and K concentrations in B than control leaves, according to the leaf stage. This induced B trees, higher values in both total biomass than controls (+22 %) in well-watered plants. Moreover, the higher water availability in soil amended with biochar helped B trees to tolerate water stress, with better leaf photosynthetic performances and a faster recovery than stressed controls after the re-watering. This study highlights the dual function of the biochar, improving CO2 sequestration and soil properties, and at the same time, enhancing plant physiological responses to environmental constraints. The use of biochar at the tree planting, especially in an urban environment, is a feasible and environmentally sustainable strategy to improve the success during the tree establishment phase.

Gender Differences in Post-Traumatic Stress.

Acute stress can trigger cardiovascular events and disease. The earthquake is an "ideal" natural experiment for acute and chronic stress, with impact mainly on the cardiovascular system. On May 20th and 29th, 2012, two earthquakes of magnitude 5.9° to 6.4° on the Richter scale, hit the province of Modena and Reggio Emilia, an area of the north-center of Italy never considered at seismic risk. The purpose of our study was to assess whether there were gender-specific differences in stress-induced incidence of cardiovascular events and age of patients who arrived at the Emergency Departments (ED) of the three main teaching hospitals of the University of Modena and Reggio Emilia. Global access of patients, divided in relation to age, gender, and diagnosis was compared with that one detected in the same departments and in the same interval of time in 2010. The data collected were relative to consecutive cases derived by retrospective chart and acute cardiovascular events were classified according to ICD-9 (International Classification of Diseases, ninth revision). A total of 1,401 accesses were recorded in the year of earthquake versus 530 in 2010 (p ≤ 0.05), with no statistically significant differences in number of cases and mean age in relation to gender, despite the number of women exceeded that of men in 2012 (730 vs. 671); the opposite occurred, in 2010 (328 vs. 202). The gender analysis of 2012 showed a prevalence of acute coronary syndromes (ACSs 177 vs. 73, p ≤ 0.03) in men, whereas women presented more strokes and transient ischemic attacks (TIAs) (90 vs. 94, p ≤ 0.05), atrial fibrillation (120 vs. 49, p ≤ 0.05), deep venous thrombosis and pulmonary embolism (DVT/PE; 64 vs. 9, p ≤ 0.05), panic attacks (124 vs. 26, p ≤ 0.03), aspecific chest pain (122 vs. 18, p ≤ 0.05), TakoTsubo cardiomyopathy (10 vs. 0, p ≤ 0.05), and DVT/PE (61 vs. 3, p ≤ 0.03). The gender analysis of 2010 showed no difference in number of accesses and age, with higher incidence of ACS in men (130 vs. 34, p ≤ 0.05) and aspecific chest pain in women (42 vs. 5, p ≤ 0.05). The analysis between 2012 and the standard period (2010) showed women recurring to ED in larger number with more panic attacks (124 vs. 3, p ≤ 0.01), more atrial fibrillation (120 vs. 40, p ≤ 0.01) and, as a possible consequence, more TIAs and strokes (190 vs. 25, p ≤ 0.005), more TakoTsubo (10 vs. 0, p ≤ 0.05), DVT/PE (61 vs. 3, p ≤ 0.05), and aspecific chest pain (122 vs. 5, p ≤ 0.01). The difference between men's accesses to ED was less striking, but in 2012 men reported more panic attacks (26 vs. none, p ≤ 0.05), more atrial fibrillations, TIAs, and strokes (49 vs. 13, p ≤ 0.05 and 94 vs. 18, p ≤ 0.03). In conclusion, clinical (stress induced) events recorded during and immediately after the 2012 earthquakes were quite different between women and men, although the pathophysiological mechanism was probably the same, consisting acute sympathetic nervous activation, with elevation of blood pressure and heart rate, endothelial dysfunction, platelet and hemostatic activation, increased blood viscosity, and hypercoagulation. Women, in our observation, appeared to be more sensitive and responsive to acute stress, although men also appeared to suffer from stress effects when compared with a standard period, which, nevertheless, reflects in our population the most common epidemiology of gender difference in ED accesses for cardiovascular events.

Retrograde popliteal access as bail-out strategy for challenging occlusions of the superficial femoral artery: a multicenter registry.

BACKGROUND: The concomitant use of femoral and popliteal accesses has been recommended for challenging superficial femoral artery (SFA) occlusions, but no comprehensive comparison of this approach to a strategy of femoral access only is available. We thus aimed to appraise the risk-benefit balance of retrograde popliteal access as bail-out strategy for SFA occlusions. METHODS: Consecutive patients with symptomatic SFA occlusion and undergoing percutaneous revascularization were enrolled. We distinguished patients in whom retrograde popliteal access was required as bail-out strategy versus those not requiring such access. The primary end-point was procedural success. RESULTS: A total of 130 patients (152 limbs) were included, with 23 patients (25 limbs) requiring retrograde popliteal access. Occlusion length was 20.6 ± 8.8 cm in those requiring popliteal access versus 18.5 ± 8.5 cm in those without popliteal access, with TASC C/D lesions in 23 (92%) versus 106 (83%). Procedural success was achieved in 92 out of 107 patients (86.0%) treated with a standard approach and 22 out of 23 patients (95.7%) treated with retrograde popliteal access (total 114 out of 130 [87.7%]) and 112 out of 127 limbs (88.2%) and 24 out of 25 limbs (96.0%), respectively (total 136 out of 152 [89.5%]). No significant increase in early or long-term adverse events was associated with retrograde popliteal access. CONCLUSIONS: Whenever standard access sites do not enable successful recanalization of SFA occlusions, retrograde popliteal access can be safely and effectively envisioned as bail-out strategy.

Defining high-risk patients with ST-segment elevation acute myocardial infarction undergoing primary percutaneous coronary intervention: a comparison among different scoring systems and clinical definitions.

BACKGROUND: Identification of high-risk patients with ST-segment elevation acute myocardial infarction (STEMI) is of the utmost importance for adequate patient stratification and evaluation of additive treatments. However, there is no consensus on the optimal definition of high-risk patients. METHODS: We therefore compared 5 scoring systems in the assessment of the risk of 30-day mortality in 3214 patients with STEMI treated with primary percutaneous coronary intervention (PCI). RESULTS: Clinical scores showed a large variability in risk stratifying patients. Identification of high-risk patients ranged from 15% (PAMI score ≥ 9) to 66% (McNamara definition). McNamara, Antoniucci and Brodie definitions had the best sensitivity (0.87-0.88 and 95% confidence intervals (CI) ranging from 0.82-0.93) while PAMI ≥ 9 had the best specificity (0.87 with 95% CI of 0.86-0.88), while its sensitivity was quite low (0.42). In a sample size simulation of a trial aimed at demonstrating a 33% difference in 30-day mortality between two hypothetical treatments, the number of STEMI patients needed to be screened varied from 4712 for the Brodie definition to 9038 for the PAMI ≥ 9 score. CONCLUSIONS: There is a large variability in risk stratification, sensitivity, specificity and predictive values among different scoring systems. These considerations should be taken into account when designing randomised trials.

Prognostic implications of ST-segment elevation resolution in patients with ST-segment elevation acute myocardial infarction treated with primary or facilitated percutaneous coronary intervention.

Scant data are available on the relation between ST-segment elevation (STE) resolution and 30-day mortality in patients with STE acute myocardial infarction treated with percutaneous coronary intervention in contemporary, real world, clinical practice. Furthermore, whether the prognostic value of STE resolution is influenced by the patient clinical risk profile or postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow has never been investigated. Lombardima was an observational registry implemented in Lombardy, a Northern Italian region. The clinical characteristics, electorcardiographic parameters, and procedural data were prospectively entered into a Web-based database. In the present study, we enrolled 3,403 patients. STE resolution occurred in 2,452 patients (group 1) and did not in 951 patients (group 2). The mortality rate was 2.4% in group 1 and 11.3% in group 2 (p <0.001). After stratifying patients according to their TIMI risk index, we observed that STE resolution was an independent predictor of 30-day mortality across all spectrum of clinical risk. Furthermore, in patients with TIMI 3 flow, STE resolution remained an independent predictor of 30-day mortality (p <0.0001). In conclusion, STE resolution was a strong and independent predictor of 30-day mortality in patients with STE acute myocardial infarction undergoing percutaneous coronary intervention across all spectrum of clinical risk.

Impact of acute coronary syndromes on two-year clinical outcomes in patients with unprotected left main coronary artery stenosis treated with drug-eluting stents.

In this study we investigated the impact of acute coronary syndromes (ACSs) on clinical outcomes in patients with unprotected left main coronary artery (ULMCA) stenosis treated with drug-eluting stents (DESs). In this multicenter, retrospective, observational study we enrolled 1,101 patients with ULMCA stenosis treated with DESs. Six hundred eleven patients presented with ACS and 490 had stable coronary artery disease. ACS was defined as the presence of unstable angina or non-ST-segment elevation myocardial infarction (MI). During 2-year follow-up, the adjusted hazard ratio of cardiac mortality and MI of patients with ACS versus stable patients was 2.42 (95% confidence interval 1.37 to 4.28, p = 0.002). We observed a stepwise risk increase, namely patients with stable coronary disease had the lowest risk, patients with unstable angina an intermediate risk, and patients with non-ST-segment elevation MI the highest risk. The increased risk of cardiac mortality and MI of patients with ACS was concentrated in the first year after DES implantation. In conclusion, patients with ULMCA stenosis and ACS treated with DESs have an increased risk of cardiac mortality and MI during the first year after the intervention compared to stable patients.

A randomised study comparing the antiplatelet and antiinflammatory effect of clopidogrel 150 mg/day versus 75 mg/day in patients with ST-segment elevation acute myocardial infarction and poor responsiveness to clopidogrel: results from the DOUBLE study.

INTRODUCTION: The antiplatelet effect of standard or increased clopidogrel doses in patients with ST- segment elevation acute myocardial infarction (STEMI) has never been studied. In this study we compared the antiplatelet effect of a 75 mg daily maintenance dose of clopidogrel with 150 mg in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). MATERIALS AND METHODS: Fifty-four patients with STEMI undergoing PCI were randomly allocated to receive either 75 mg/day clopidogrel (group 1) or 150 mg/day (group 2) for 1 month. Platelet function, measured by 5 different assays, was determined at 3 time points: 38+/-8 hours after the procedure, 1 week and 1 month after randomization. RESULTS: In group 1, mean +/- SD platelet reactivity index (PRI) measured with the VASP assay was 57.7+/-15.7% and 46.9+/-15.7% at 1 week and 1 month, respectively, compared to 38.8+/-15.7% and 34.9+/-12.6% in group 2 (p=0.0001). Same results were observed for light transmittance aggregometry, whole blood aggregometry and VerifyNow, but not for thromboelastometry. In contrast to what may be expected, the 75 mg daily maintenance dose took longer than 1-week to provide the full clopidogrel antiplatelet effect. Furthermore, patients in group 2 had a nearly 50% reduction in C-reactive protein levels both at 1 week and 1 month. CONCLUSION: In patients with STEMI and poor responsiveness to clopidogrel a 150 mg daily maintenance dose of clopidogrel is associated with a significant reduction of platelet aggregation and a trend towards reduced inflammation.

Ostial and midshaft lesions vs. bifurcation lesions in 1111 patients with unprotected left main coronary artery stenosis treated with drug-eluting stents: results of the survey from the Italian Society of Invasive Cardiology.

AIMS: In this study, we compared the cumulative risk of major adverse cardiac events (MACE) of patients with distal unprotected left main coronary artery (ULMCA) stenosis with those of patients with ostial and midshaft lesions treated with drug-eluting stent (DES). METHODS AND RESULTS: The survey promoted by the Italian Society of Invasive Cardiology on ULMCA stenosis was an observational study involving 19 high-volume Italian centres. We enrolled 1111 patients with ULMCA stenosis treated with DES. Major adverse cardiac events were defined as death, myocardial infarction, and target lesion revascularization. Three hundred and thirty-four patients had ostial or midshaft lesions (group 1) and 777 bifurcations (group 2). The adjusted hazards ratio of the risk of 2 year MACE of patients in group 2 vs. patients in group 1 was 1.50 (P = 0.024). However, we observed that there was a significant difference between patients with bifurcations treated with two stents and those in group 1 (P = 0.001), but not between patients with bifurcations treated with one stent and those in group 1 (P = 0.38). CONCLUSION: Patients with bifurcations have a worse outcome than patients with ostial and midshaft lesions. However, the technique used to treat bifurcations has a significant impact on clinical outcomes.

Temporal pattern of ischemic events in relation to dual antiplatelet therapy in patients with unprotected left main coronary artery stenosis undergoing percutaneous coronary intervention.

OBJECTIVES: The aim of this study was to investigate whether there is a temporal pattern of ischemic events in relation to dual antiplatelet therapy in patients with unprotected left main coronary artery (ULMCA) stenosis treated with percutaneous coronary intervention (PCI). BACKGROUND: Identifying which periods during follow-up of patients with ULMCA stenosis treated with PCI are associated with higher risk of clinical events might help to improve therapeutic strategies. METHODS: We analyzed data from 15 centers involved in an observational study conducted by the Italian Society of Invasive Cardiology on patients with ULMCA stenosis treated with PCI. Eight hundred ninety-four patients were enrolled. RESULTS: At 30-day follow-up, the rate of cardiac mortality and myocardial infarction (MI) was 5.4%. In patients still taking dual antiplatelet therapy, the adjusted incidence rate ratio/10,000 patient-days of the combination of cardiac mortality and MI in the 31- to 180-day interval compared with the 181- to 360-day interval after PCI was 3.64 (p = 0.035). This risk was particularly high in patients with acute coronary syndromes. After stopping clopidogrel, the adjusted incidence rate ratio of cardiac mortality and MI in the 0- to 90-day interval compared with the 91- to 180-day interval was 4.20 (p = 0.009). CONCLUSIONS: In patients with ULMCA stenosis taking dual antiplatelet therapy there is an increased hazard of cardiac mortality and MI between 31 and 180 days compared with 181 to 360 days. Furthermore, there is an increased hazard of cardiac mortality and MI in the first 90 days after stopping clopidogrel.