Role of Salt Concentration in Stabilizing Charged Ni-Rich Cathode Interfaces in Li-Ion Batteries

The cathode-electrolyte interphase (CEI) in Li-ion batteries plays a key role in suppressing undesired side reactions while facilitating Li-ion transport. Ni-rich layered cathode materials offer improved energy densities, but their high interfacial reactivities can negatively impact the cycle life and rate performance. Here we investigate the role of electrolyte salt concentration, specifically LiPF6 (0.5-5 m), in altering the interfacial reactivity of charged LiN0.8Mn0.1Co0.1O2 (NMC811) cathodes in standard carbonate-based electrolytes (EC/EMC vol %/vol % 3:7). Extended potential holds of NMC811/Li4Ti5O12 (LTO) cells reveal that the parasitic electrolyte oxidation currents observed are strongly dependent on the electrolyte salt concentration. X-ray photoelectron and absorption spectroscopy (XPS/XAS) reveal that a thicker LixPOyFz-/LiF-rich CEI is formed in the higher concentration electrolytes. This suppresses reactions with solvent molecules resulting in a thinner, or less-dense, reduced surface layer (RSL) with lower charge transfer resistance and lower oxidation currents at high potentials. The thicker CEI also limits access of acidic species to the RSL suppressing transition-metal dissolution into the electrolyte, as confirmed by nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma optical emission spectroscopy (ICP-OES). This provides insight into the main degradation processes occurring at Ni-rich cathode interfaces in contact with carbonate-based electrolytes and how electrolyte formulation can help to mitigate these.

Postdischarge major bleeding, myocardial infarction, and mortality risk after coronary artery bypass grafting

OBJECTIVE

To investigate the incidence and mortality risk associated with postdischarge major bleeding after coronary artery bypass grafting (CABG), and relate this to the incidence of, and mortality risk from, postdischarge myocardial infarction.

METHODS

All patients undergoing first-time isolated CABG in Sweden in 2006-2017 and surviving 14 days after hospital discharge were included in a cohort study. Individual patient data from the SWEDEHEART Registry and five other mandatory nationwide registries were merged. Piecewise Cox proportional hazards models were used to investigate associations between major bleeding, defined as hospitalisation for bleeding, with subsequent mortality risk. Similar Cox proportional hazards models were used to investigate the association between postdischarge myocardial infarction and mortality risk.

RESULTS

Among 36 633 patients, 2429 (6.6%) had a major bleeding event and 2231 (6.1%) had a myocardial infarction. Median follow-up was 6.0 (range 0-11) years. Major bleeding was associated with higher mortality risk <30 days (adjusted HR (aHR)=20.2 (95% CI 17.3 to 23.5)), 30-365 days (aHR=3.8 (95% CI 3.4 to 4.3)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event. Myocardial infarction was associated with higher mortality risk <30 days (aHR=20.0 (95% CI 16.7 to 23.8)), 30-365 days (aHR=4.1 (95% CI 3.6 to 4.8)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event.

CONCLUSIONS

The increase in mortality risk associated with a postdischarge major bleeding after CABG is substantial and is similar to the mortality risk associated with a postdischarge myocardial infarction.

Statin treatment after surgical aortic valve replacement for aortic stenosis is associated with better long-term outcome

OBJECTIVES

The aim of this study was to evaluate the association between statin use after surgical aortic valve replacement for aortic stenosis and long-term risk for major adverse cardiovascular events (MACEs) in a large population-based, nationwide cohort.

METHODS

All patients who underwent isolated surgical aortic valve replacement due to aortic stenosis in Sweden 2006-2020 and survived 6 months after discharge were included. Individual patient data from 5 nationwide registries were merged. Primary outcome is MACE (defined as all-cause mortality, myocardial infarction or stroke). Multivariable Cox regression model adjusted for age, sex, comorbidities, valve type, operation year and secondary prevention medications is used to evaluate the association between time-updated dispense of statins and long-term outcome in the entire study population and in subgroups based on age, sex and comorbidities.

RESULTS

A total of 11 894 patients were included. Statins were dispensed to 49.8% (5918/11894) of patients at baseline, and 51.0% (874/1713) after 10 years. At baseline, 3.6% of patients were dispensed low dose, 69.4% medium dose and 27.0% high-dose statins. After adjustments, ongoing statin treatment was associated with a reduced risk for MACE [adjusted hazard ratio 0.77 (95% confidence interval 0.71-0.83). P < 0.001], mainly driven by a reduction in all-cause mortality [adjusted hazard ratio, 0.70 (0.64-0.76)], P < 0.001. The results were consistent in all subgroups.

CONCLUSIONS

The results suggest that statin therapy might be beneficial for patients undergoing surgical aortic valve replacement for aortic stenosis. Randomized controlled trials are warranted to establish causality between statin treatment and improved outcome.

Platelet-leukocyte aggregate formation and inflammation in patients with pulmonary arterial hypertension and CTEPH

Pulmonary hypertension (PH) is defined by increased mean pulmonary artery pressure, and the clinical classification includes five etiologies, of which we investigated subgroup 1, pulmonary arterial hypertension (PAH) and subgroup 4, chronic thrombotic and/or embolic disease (CTEPH). Platelets participate in both innate and adaptive immune responses and could possibly contribute to the suggested systemic inflammation associated with PAH. In this study, we utilized flow cytometry to analyze platelet activation and platelet-monocyte (PMA) and granulocyte (PGA) aggregates in PAH and CTEPH patients and healthy control subjects. The plasma concentration of proinflammatory cytokines was measured by multiplex electrochemiluminescence. Our main finding is that circulating platelets are activated in the circulation and form aggregates with both monocytes and granulocytes in patients with idiopathic PAH (IPAH), associated PAH (APAH) and pulmonary hypertension due to CTEPH. There was a strong correlation between the platelet activation, assessed as P-selectin, and the number of aggregates formed. IL-6, IL-8, IL-10 and TNF-α were increased in all PH subgroups as compared to healthy controls, and PMAs were associated with circulating IL-6, IL-8 and IL-10, whereas PGAs were associated with IL-6. The increased concentrations of platelet-leukocyte aggregates found in PAH/CTEPH patients might thus contribute to the inflammatory state in PH.

Beta blockers and long-term outcome after coronary artery bypass grafting: a nationwide observational study

Aims

Beta blockers are associated with improved outcomes for selected patients with cardiovascular disease. We assessed long-term utilization of beta blockers after coronary artery bypass grafting (CABG) and its association with outcome.

Methods and results

All 35 184 patients in Sweden who underwent first-time isolated CABG between 1 January 2006 and 31 December 2017 and were followed for at least 6 months were included in a nationwide observational study. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between different types of beta blockers and outcomes. The primary outcome was major adverse cardiovascular events (MACEs), a composite of all-cause mortality, stroke, and myocardial infarction (MI). Subgroup analyses were performed in patients with and without previous MI, heart failure, and reduced left ventricular ejection fraction (LVEF). Median follow-up was 5.2 years (range 0–11). At baseline, 33 159 (94.2%) patients were dispensed beta blockers, 30 563 (92.2%) of which were cardioselective beta blockers. After 10 years, the dispensing of cardioselective beta blockers had declined to 73.7% of all patients. Ongoing treatment with cardioselective beta blockers was associated with a slight reduction in MACEs [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.89–0.98, P = 0.0063]. The reduction was largely driven by a reduced risk of MI (HR 0.83, 95% CI 0.75–0.92, P = 0.0003), while there was no significant reduction in all-cause mortality (HR 0.99, 95% CI 0.93–1.05) and stroke (HR 0.96, 95% CI 0.87–1.05). The reduced risk for MI was consistent in all the investigated subgroups.

Conclusion

Ongoing treatment with cardioselective beta blockers after CABG is associated with a reduction in MACEs, mainly because of reduced long-term risk for MI. The association between cardioselective beta blockers and MI was consistent in patients with and patients without previous MI, heart failure, atrial fibrillation, or reduced LVEF.

Five year risk assessment and treatment patterns in patients with chronic thromboembolic pulmonary hypertension

AIMS

Repeated risk assessments and treatment patterns over long time are sparsely studied in chronic thromboembolic pulmonary hypertension (CTEPH); thus, we aimed to investigate changes in risk status and treatment patterns in incident patients with CTEPH over a 5 year period.

METHODS AND RESULTS

Descriptive and explorative study including 311 patients diagnosed with CTEPH 2008-2019 from the Swedish pulmonary hypertension registry, stratified by pulmonary endarterectomy surgery (PEA). Risk and PH-specific treatment were assessed in surgically treated (PEA) and medically treated (non-PEA) patients at diagnosis and up to 5 years follow-up. Data are presented as median (Q1-Q3), count or per cent. Prior to surgery, 63% in the PEA-group [n = 98, age 64 (51-71) years, 37% female] used PH-specific treatment and 20, 69, and 10% were assessed as low, intermediate or high risk, respectively. After 1 year post-surgery, 34% had no PH-specific treatment or follow-up visit registered despite being alive at 5 years. Of patients with a 5 year visit (n = 23), 46% were at low and 54% at intermediate risk, while 91% used PH-specific treatment. In the non-PEA group [n = 213, age 72 (65-77) years, 56% female], 28% were assessed as low, 61% as intermediate and 11% as high risk. All patients at high risk versus 50% at low risk used PH-specific treatment. The 1 year mortality was 6%, while the risk was unchanged in 57% of the patients; 14% improved from intermediate to low risk, and 1% from high to low risk. At 5 years, 27% had a registered visit and 28% had died. Of patients with a 5 year visit (n = 58), 38% were at low, 59% at intermediate and 1% at high risk, and 86% used PH-specific treatment.

CONCLUSIONS

Risk status assessed pre-surgery did not foresee long-term post-PEA risk and pre-surgery PH-specific treatment did not foresee long-term post-PEA treatment. Medically treated CTEPH patients tend to remain at the same risk over time, suggesting a need for improved treatment strategies in this group.

Associations between medical therapy after surgical aortic valve replacement for aortic stenosis and long-term mortality: a report from the SWEDEHEART registry

AIMS

The association between the use of statins, renin-angiotensin system (RAS) inhibitors, and/or β-blockers and long-term mortality in patients with aortic stenosis (AS) who underwent surgical aortic valve replacement (SAVR) is unknown.

METHODS AND RESULTS

All patients with AS who underwent isolated first-time SAVR in Sweden from 2006 to 2017 and survived 6 months after discharge were included. Individual patient data from four mandatory nationwide registries were merged. Cox proportional hazards models, with time-updated data on medication status and adjusted for age, sex, comorbidities, type of prosthesis, and year of surgery, were used to investigate associations between dispensed statins, RAS inhibitors, and β-blockers and all-cause mortality. In total, 9553 patients were included, and the median follow-up time was 4.9 years (range 0-11); 1738 patients (18.2%) died during follow-up. Statins were dispensed to 49.1% and 49.0% of the patients within 6 months of discharge from the hospital and after 10 years, respectively. Corresponding figures were 51.4% and 53.9% for RAS inhibitors and 79.3% and 60.7% for β-blockers. Ongoing treatment was associated with lower mortality risk for statins {adjusted hazard ratio (aHR) 0.67 [95% confidence interval (95% CI) 0.60-0.74]; P < 0.001} and RAS inhibitors [aHR 0.84 (0.76-0.93); P < 0.001] but not for β-blockers [aHR 1.17 (1.05-1.30); P = 0.004]. The associations were robust in subgroups based on age, sex, and comorbidities (P for interactions >0.05).

CONCLUSIONS

The results of this large population-based real-world study support the use of statins and RAS inhibitors for patients who underwent SAVR due to AS.

Electrolyte Reactivity at the Charged Ni-Rich Cathode Interface and Degradation in Li-Ion Batteries

The chemical and electrochemical reactions at the positive electrode-electrolyte interface in Li-ion batteries are hugely influential on cycle life and safety. Ni-rich layered transition metal oxides exhibit higher interfacial reactivity than their lower Ni-content analogues, reacting via mechanisms that are poorly understood. Here, we study the pivotal role of the electrolyte solvent, specifically cyclic ethylene carbonate (EC) and linear ethyl methyl carbonate (EMC), in determining the interfacial reactivity at charged LiNi_0.33Mn_0.33Co_0.33O₂ (NMC111) and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathodes by using both single-solvent model electrolytes and the mixed solvents used in commercial cells. While NMC111 exhibits similar parasitic currents with EC-containing and EC-free electrolytes during high voltage holds in NMC/Li₄Ti₅O₁₂ (LTO) cells, this is not the case for NMC811. Online gas analysis reveals that the solvent-dependent reactivity for Ni-rich cathodes is related to the extent of lattice oxygen release and accompanying electrolyte decomposition, which is higher for EC-containing than EC-free electrolytes. Combined findings from electrochemical impedance spectroscopy (EIS), TEM, solution NMR, ICP, and XPS reveal that the electrolyte solvent has a profound impact on the degradation of the Ni-rich cathode and the electrolyte. Higher lattice oxygen release with EC-containing electrolytes is coupled with higher cathode interfacial impedance, a thicker oxygen-deficient rock-salt surface reconstruction layer, more electrolyte solvent and salt breakdown, and higher amounts of transition metal dissolution. These processes are suppressed in the EC-free electrolyte, highlighting the incompatibility between Ni-rich cathodes and conventional electrolyte solvents. Finally, new mechanistic insights into the chemical oxidation pathways of electrolyte solvents and, critically, the knock-on chemical and electrochemical reactions that further degrade the electrolyte and electrodes curtailing battery lifetime are provided.

Cycle-Induced Interfacial Degradation and Transition-Metal Cross-Over in LiNi0.8Mn0.1Co0.1O2-Graphite Cells

Ni-rich lithium nickel manganese cobalt (NMC) oxide cathode materials promise Li-ion batteries with increased energy density and lower cost. However, higher Ni content is accompanied by accelerated degradation and thus poor cycle lifetime, with the underlying mechanisms and their relative contributions still poorly understood. Here, we combine electrochemical analysis with surface-sensitive X-ray photoelectron and absorption spectroscopies to observe the interfacial degradation occurring in LiNi_0.8Mn_0.1Co_0.1O₂-graphite full cells over hundreds of cycles between fixed cell voltages (2.5-4.2 V). Capacity losses during the first ∼200 cycles are primarily attributable to a loss of active lithium through electrolyte reduction on the graphite anode, seen as thickening of the solid-electrolyte interphase (SEI). As a result, the cathode reaches ever-higher potentials at the end of charge, and with further cycling, a regime is entered where losses in accessible NMC capacity begin to limit cycle life. This is accompanied by accelerated transition-metal reduction at the NMC surface, thickening of the cathode electrolyte interphase, decomposition of residual lithium carbonate, and increased cell impedance. Transition-metal dissolution is also detected through increased incorporation into and thickening of the SEI, with Mn found to be initially most prevalent, while the proportion of Ni increases with cycling. The observed evolution of anode and cathode surface layers improves our understanding of the interconnected nature of the degradation occurring at each electrode and the impact on capacity retention, informing efforts to achieve a longer cycle lifetime in Ni-rich NMCs.

Statins for secondary prevention and major adverse events after coronary artery bypass grafting

OBJECTIVE

The objective of this study was to evaluate the association of statin use after coronary artery bypass grafting (CABG) and long-term adverse events in a large population-based, nationwide cohort.

METHODS

All 35,193 patients who underwent first-time isolated CABG in Sweden from 2006 to 2017 and survived at least 6 months after surgery were included. Individual patient data from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) and 4 other nationwide registries were merged. Multivariable Cox regression models adjusted for age, sex, comorbidities, and time-updated treatment with other secondary preventive medications were used to evaluate the associations between statin treatment and outcomes. The primary end point was major adverse cardiovascular events (MACE). Median follow-up time to MACE was 5.3 (interquartile range, 2.5-8.2) years.

RESULTS

Statins were dispensed to 95.7% of the patients six months after discharge and to 78.9% after 10 years. At baseline, 1.4% of patients were prescribed low-, 57.6% intermediate-, and 36.7% high-dose statins. Ongoing statin treatment was associated with markedly reduced risk of MACE (adjusted hazard ratio [aHR], 0.56 [95% CI, 0.53-0.59]), all-cause mortality (aHR, 0.53 [95% CI, 0.50-0.56]), cardiovascular death (aHR, 0.54 [95% CI, 0.50-0.59]), myocardial infarction (aHR, 0.61 [95% CI, 0.55-0.69]), stroke (aHR, 0.66 [95% CI, 0.59-0.73]), new revascularization (aHR, 0.79 [95% CI, 0.70-0.88]), new angiography (aHR, 0.81 [95% CI, 0.74-0.88]), and dementia (aHR, 0.74 [95% CI, 0.65-0.85]; all P < .01), irrespective of the statin dose.

CONCLUSIONS

Ongoing statin use was associated with a markedly reduced incidence of adverse events and mortality after CABG. Initiating and maintaining statin medication is essential in CABG patients.

Comparison of Midterm Outcomes Associated With Aspirin and Ticagrelor vs Aspirin Monotherapy After Coronary Artery Bypass Grafting for Acute Coronary Syndrome

IMPORTANCE

Guidelines recommend dual antiplatelet therapy after coronary artery bypass grafting (CABG) for patients with acute coronary syndrome (ACS). However, the evidence for these recommendations is weak.

OBJECTIVE

To compare midterm outcomes after CABG in patients with ACS treated postoperatively with acetylsalicylic acid (ASA) and ticagrelor or with ASA monotherapy.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used merged data from several national registries of Swedish patients who were diagnosed with ACS and subsequently underwent CABG. All included patients underwent isolated CABG in Sweden between 2012 and 2017 with an ACS diagnosis less than 6 weeks before the procedure, survived 14 days after discharge from hospital, and were treated postoperatively with ASA plus ticagrelor or ASA monotherapy. A multivariable Cox regression model was used for the main analysis, and propensity score-matched models were performed as sensitivity analysis. Data were analyzed between May and September 2020.

EXPOSURES

Postoperative antiplatelet treatment, defined as filled prescriptions, with either ASA and ticagrelor or ASA only.

MAIN OUTCOMES AND MEASURES

Major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, and stroke, and major bleeding, at 12 months and at the end of follow-up.

RESULTS

A total of 6558 patients (5281 [80.5%] men; mean [SD] age at surgery, 67.6 [9.3] years) were included; 1813 (27.6%) were treated with ASA plus ticagrelor and 4745 (72.4%) were treated with ASA monotherapy. Crude MACE rate was 3.0 per 100 person years (95% CI, 2.5-3.6 per 100 person years) in the ASA plus ticagrelor group and 3.8 per 100 person years (95% CI, 3.5-4.1 per 100 person years) in the ASA group. After adjustment, there was no significant difference in MACE risk between ASA plus ticagrelor vs ASA only, neither during the first 12 months (adjusted hazard ratio [aHR], 0.84; 95% CI, 0.58-1.21; P = .34) or during total follow-up (aHR, 0.89; 95% CI, 0.71-1.11; P = .29). The use of ASA plus ticagrelor was associated with a significantly increased risk for major bleeding during the first 12 months (aHR, 1.90; 95% CI, 1.16-3.13; P = .011). Sensitivity analyses confirmed the results.

CONCLUSIONS AND RELEVANCE

In patients with ACS who survived 2 weeks after CABG, no significant difference in the risk of death or ischemic events could be demonstrated between ASA plus ticagrelor and patients treated with ASA only, while the risk for major bleeding was higher in patients treated with ASA plus ticagrelor. Sufficiently powered prospective randomized trials comparing different antiplatelet therapy strategies after CABG are warranted.

Secondary prevention medications after coronary artery bypass grafting and long-term survival: a population-based longitudinal study from the SWEDEHEART registry

Aims

To evaluate the long-term use of secondary prevention medications [statins, β-blockers, renin–angiotensin–aldosterone system (RAAS) inhibitors, and platelet inhibitors] after coronary artery bypass grafting (CABG) and the association between medication use and mortality.

Methods and results

All patients who underwent isolated CABG in Sweden from 2006 to 2015 and survived at least 6 months after discharge were included (n = 28 812). Individual patient data from SWEDEHEART and other mandatory nationwide registries were merged. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between medication use and long-term mortality. Statins were dispensed to 93.9% of the patients 6 months after discharge and to 77.3% 8 years later. Corresponding figures for β-blockers were 91.0% and 76.4%, for RAAS inhibitors 72.9% and 65.9%, and for platelet inhibitors 93.0% and 79.8%. All medications were dispensed less often to patients ≥75 years. Treatment with statins [hazard ratio (HR) 0.56, 95% confidence interval (95% CI) 0.52–0.60], RAAS inhibitors (HR 0.78, 95% CI 0.73–0.84), and platelet inhibitors (HR 0.74, 95% CI 0.69–0.81) were individually associated with lower mortality risk after adjustment for age, gender, comorbidities, and use of other secondary preventive drugs (all P < 0.001). There was no association between β-blockers and mortality risk (HR 0.97, 95% CI 0.90–1.06; P = 0.54).

Conclusion

The use of secondary prevention medications after CABG was high early after surgery but decreased significantly over time. The results of this observational study, with inherent risk of selection bias, suggest that treatment with statins, RAAS inhibitors, and platelet inhibitors is essential after CABG whereas the routine use of β-blockers may be questioned.

Renin-angiotensin system inhibition and outcome after coronary artery bypass grafting: A population-based study from the SWEDEHEART registry

BACKGROUND

Renin-angiotensin system (RAS) inhibitors are recommended postoperatively to coronary artery bypass grafting (CABG) patients with reduced left ventricular function, diabetes, hypertension or previous myocardial infarction, but not to remaining patients. The aim of the study was to assess the long-term utilization of RAS inhibitors after CABG in patients with and without indication for treatment, and its association with outcome.

METHODS

All patients (n = 28,782) not meeting exclusion criterion in Sweden who underwent isolated first time CABG from 2006 to 2015 were included using nationwide registries. The association between treatment and outcome was assessed using adjusted Cox regression models with time-updated data on medications. The primary outcome was major adverse cardiovascular events (MACE), defined as all-cause mortality, stroke and/or myocardial infarction.

RESULTS

At baseline 26,284 (91.3%) of the patients had at least one indication for RAS inhibition while 2498 (8.7%) had not. RAS inhibitors were dispensed to 77.0% and 29.7% of patients with and without indication respectively. Dispense declined over time. RAS inhibition was associated with a reduction in MACE in the whole study population (adjusted hazard ratio (aHR) 0.88, 95% confidence interval (95% CI) 0.83-0.93, p < 0.0001), and in patients with (aHR 0.87 95% CI: 0.82-0.93, p < 0.0001) and without indication (aHR 0.75, 95% CI: 0.58-0.98, p = 0.034).

CONCLUSIONS

RAS inhibition is underutilized after CABG. The use of RAS inhibitors was associated with a reduction in MACE, both in patients with and without indication for treatment. The results suggest that RAS inhibition is beneficial for all CABG patients. Randomized controlled trials are necessary to confirm this hypothesis.

Role of Extracellular Vesicles in Pulmonary Arterial Hypertension: Modulation of Pulmonary Endothelial Function and Angiogenesis

OBJECTIVE

Extracellular vesicles (EVs) have the potential to act as intercellular communicators. The aims were to characterize circulating EVs in patients with pulmonary arterial hypertension (PAH) and to explore whether these EVs contribute to endothelial activation and angiogenesis. Approach and Results: Patients with PAH (n=70) and healthy controls (HC; n=20) were included in this cross-sectional study. EVs were characterized and human pulmonary endothelial cells (hPAECs) were incubated with purified EVs. Endothelial cell activity and proangiogenic markers were analyzed. Tube formation analysis was performed for hPAECs, and the involvement of PSGL-1 (P-selectin glycoprotein ligand 1) was evaluated. The numbers of CD62P⁺, CD144⁺, and CD235a EVs were higher in blood from PAH compared with HC. Thirteen proteins were differently expressed in PAH and HC EVs, where complement fragment C1q was the most significantly elevated protein (P=0.0009) in PAH EVs. Upon EVs-internalization in hPAECs, more PAH compared with HC EVs evaded lysosomes (P<0.01). As oppose to HC, PAH EVs stimulated hPAEC activation and induced transcription and translation of VEGF-A (vascular endothelial growth factor A; P<0.05) and FGF (fibroblast growth factor; P<0.005) which were released in the cell supernatant. These proangiogenic proteins were higher in patient with PAH plasma compered with HC. PAH EVs induced a complex network of angiotubes in vitro, which was abolished by inhibitory PSGL-1antibody. Anti-PSGL-1 also inhibited EV-induced endothelial cell activation and PAH EV dependent increase of VEGF-A.

CONCLUSIONS

Patients with PAH have higher levels of EVs harboring increased amounts of angiogenic proteins, which induce activation of hPAECs and in vitro angiogenesis. These effects were partly because of platelet-derived EVs evasion of lysosomes upon internalization within hPAEC and through possible involvement of P-selectin-PSGL-1 pathway.

Socioeconomic Factors, Secondary Prevention Medication, and Long-Term Survival After Coronary Artery Bypass Grafting: A Population-Based Cohort Study From the SWEDEHEART Registry

Background Low income and short education have been found to be independently associated with inferior survival after coronary artery bypass grafting (CABG), whereas the use of secondary prevention medications is associated with improved survival. We investigated whether underusage of secondary prevention medications contributes to the inferior long-term survival in CABG patients with a low income and short education. Methods and Results Patients who underwent CABG in Sweden between 2006 to 2015 and survived at least 6 months after discharge (n=28 448) were included in a population-based cohort study. Individual patient data from 5 national registries, including the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry, covering dispensing of secondary prevention medications (statins, platelet inhibitors, β-blockers, and RAAS inhibitors), socioeconomic factors, patient characteristics, comorbidity, and long-term mortaity were merged. All-cause mortality risk was estimated using multivariable Cox regression models adjusted for patient characteristics, baseline comorbidities, time-updated secondary prevention medications, and socioeconomic status. Long-term mortality was higher in patients with a low income and short education. Statins and platelet inhibitors were dispensed less often to patients with a low income, both at baseline and after 8 years. The decline in dispensing over time was steeper for low-income patients. Short education was not associated with reduced dispensing of any secondary prevention medication. Use of statins (adjusted hazard ratio=0.57 [95% CI, 0.53-0.61]), RAAS inhibitors (adjusted hazard ratio=0.78 [0.73-0.84]), and platelet inhibitors (adjusted hazard ratio=0.74 [0.68-0.80]) were associated with reduced long-term mortality irrespective of socioeconomic status. Conclusions Secondary prevention medications are dispensed less often after CABG to patients with low income. Underusage of secondary prevention medications after CABG is associated with increased mortality risk independently of income and extent of education.

Randomized trial of a left ventricular assist device as destination therapy versus guideline-directed medical therapy in patients with advanced heart failure. Rationale and design of the SWEdish evaluation of left Ventricular Assist Device (SweVAD) trial

AIMS

Patients with advanced heart failure (AdHF) who are ineligible for heart transplantation (HTx) can become candidates for treatment with a left ventricular assist device (LVAD) in some countries, but not others. This reflects the lack of a systematic analysis of the usefulness of LVAD systems in this context, and of their benefits, limitations and cost-effectiveness. The SWEdish evaluation of left Ventricular Assist Device (SweVAD) study is a Phase IV, prospective, 1:1 randomized, non-blinded, multicentre trial that will examine the impact of assignment to mechanical circulatory support with guideline-directed LVAD destination therapy (GD-LVAD-DT) using the HeartMate 3 (HM3) continuous flow pump vs. guideline-directed medical therapy (GDMT) on survival in a population of AdHF patients ineligible for HTx.

METHODS

A total of 80 patients will be recruited to SweVAD at the seven university hospitals in Sweden. The study population will comprise patients with AdHF (New York Heart Association class IIIB-IV, INTERMACS profile 2-6) who display signs of poor prognosis despite GDMT and who are not considered eligible for HTx. Participants will be followed for 2 years or until death occurs. Other endpoints will be determined by blinded adjudication. Patients who remain on study-assigned interventions beyond 2 years will be asked to continue follow-up for outcomes and adverse events for up to 5 years.

CONCLUSION

The SweVAD study will compare survival, medium-term benefits, costs and potential hazards between GD-LVAD-DT and GDMT and will provide a valuable reference point to guide destination therapy strategies for patients with AdHF ineligible for HTx.

Predictors and impact of massive bleeding in acute type A aortic dissection

Objectives

Bleeding complications associated with acute type A aortic dissection (aTAAD) are a well-known clinical problem. Here, we evaluated predictors of massive bleeding related to aTAAD and associated surgery and assessed the impact of massive bleeding on complications and survival.

Methods

This retrospective study of 256 patients used Blood Conservation Using Antifibrinolytics in a Randomized Trial (BART) criteria to define massive bleeding, which was met by 66 individuals (Group I) who were compared to the remaining patients (Group II). Multivariable logistic regression was used to identify independent predictors of massive bleeding and in-hospital mortality, Kaplan-Meier estimates for analysis of late survival, and Cox regression analysis to evaluate independent predictors of late mortality.

Results

Independent predictors of massive bleeding included symptom duration (odds ratio [OR], 0.974 per hour increment; 95% confidence interval [CI], 0.950-0.999; P  =   0.041) and DeBakey type 1 dissection (OR, 2.652; 95% CI, 1.004-7.008; P  =   0.049). In-hospital mortality was higher in Group I (30.3% vs 8.0%, P  <0.001). Kaplan-Meier estimates of survival indicated poorer survival for Group I at 1, 3 and 5 years (68.8 ± 5.9% vs 92.8 ± 1.9%; 65.2 ± 6.2% vs 85.3 ± 2.7%; 53.9 ± 6.9% vs 82.1 ± 3.3 %, respectively; log rank P  <   0.001). Re-exploration for bleeding was an independent predictor of in-hospital (OR, 3.109; 95% CI, 1.044-9.256; P  =   0.042) and late mortalities (hazard ratio, 3.039; 95% CI, 1.605-5.757; P  =   0.001).

Conclusions

Massive bleeding in patients with aTAAD is prompted by shorter symptom duration and longer extent of dissection and has deleterious effects on outcomes of postoperative complications as well as in-hospital and late mortalities.

Use of echocardiographic pulmonary acceleration time and estimated vascular resistance for the evaluation of possible pulmonary hypertension

Background

During ultrasound examination, tricuspid regurgitation may be absent or gives a signal that is not reliable for the estimation of systolic pulmonary pressure. The aim of this study was to evaluate the usefulness of acceleration time (AT) from the right ventricular outflow tract (RVOT) as an estimation of the trans-tricuspid valve gradient (TTVG) and to investigate the correlation between estimated and invasive pulmonary vascular resistance (PVR).

Methods

The AT was correlated to the TTVG measured with routine standard echocardiography in 121 patients. In a subgroup of 29 patients, systolic pulmonary pressure (SPAP) and mean pulmonary arterial pressure (MPAP) were obtained from recent right heart catheterization (RHC).

Results

We found no significant correlation between the estimation of right atrial pressure (RAP) by echocardiography and the RAP obtained by RHC. Estimated SPAP (TTGV + RAP mean from RHC) showed a good linear relation to invasively measured SPAP. TTVG and AT showed a non-linear relation, similar to SPAP and MPAP measured by catheterization and AT. For detection of SPAP above 38 mmHg a cut-off for AT of 100 ms resulted in a sensitivity of 89% and a specificity of 84%. For detection of MPAP above 25 mmHg a cut-off for AT of 100 ms resulted in similar sensitivity and specificity. Invasive PVR and the ratio of TTVG and the time velocity integral of the RVOT (TVI _RVOT ) had a strong linear relation.

Conclusions

Our study confirms that AT appears to be useful for the evaluation of pulmonary hypertension. In high risk patients, an AT of less than 100 ms indicates a high probability of pulmonary hypertension. Furthermore, PVR estimation by ultrasound seems preferably be done by using the ratio of TTVG and TVI _RVOT.

Inhibition of monoacylglycerol lipase by troglitazone, N-arachidonoyl dopamine and the irreversible inhibitor JZL184: comparison of two different assays

BACKGROUND AND PURPOSE

Drugs used clinically usually have a primary mechanism of action, but additional effects on other biological targets can contribute to their effects. A potentially useful additional target is the endocannabinoid metabolizing enzyme monoacylglycerol lipase (MGL). We have screened a range of drugs for inhibition of MGL and compared the observed potencies using different MGL enzyme assays.

EXPERIMENTAL APPROACH

MGL activity was screened using recombinant human MGL (cell lysates and purified enzyme) with 4-nitrophenyl acetate (NPA) as substrate. 2-Oleolyglycerol metabolism by rat cerebellar cytosolic MGL and by recombinant MGL was also investigated.

KEY RESULTS

Among the 96 compounds screened in the NPA assay, troglitazone, CP55,940, N-arachidonoyl dopamine and AM404 inhibited NPA hydrolysis by the lysates with IC(50) values of 1.1, 4.9, 0.78 and 3.1µM, respectively. The potency for troglitazone is in the same range as its primary pharmacological activity, activation of peroxisome proliferator-activated receptor (PPAR) γ. Among PPARγ ligands, the potency order towards human MGL was troglitazone > ciglitazone > rosiglitazone > 15-deoxy-Δ(12,14) -prostaglandin J(2) ≈ CAY 10415 > CAY 10514. In contrast to the time-dependent inhibitor JZL184, the potency of troglitazone was dependent upon the enzyme assay system used. Thus, troglitazone inhibited rat cytosolic 2-oleoylglycerol hydrolysis less potently (IC(50) 41µM) than hydrolysis of NPA by the human MGL lysates.

CONCLUSIONS AND IMPLICATIONS

'Hits' in screening programmes for MGL inhibitors should be assessed in different MGL assays. Troglitazone may be a useful lead for the design of novel, dual action MGL inhibitors/PPARγ activators.

Dendritic cell regeneration in the bone marrow of children treated for acute lymphoblastic leukaemia

Dendritic cells (DC) play a pivotal role in coordinating functions of the immune system. Little is known about DC levels in the bone marrow (BM) of patients receiving cytostatic treatment. We investigated DC levels by flow cytometry in BM at diagnosis, during and post-treatment in 76 children with acute lymphoblastic leukaemia (ALL). The levels of both plasmacytoid DC (pDC) and myeloid DC (mDC) were profoundly reduced at diagnosis. However, the levels of pDC and mDC were significantly higher in T-precursor ALL patients when compared with B-precursor ALL patient group (P = 0.044 and 0.041 respectively). Both subsets normalized in both standard-risk (SR) and high-risk patients after the end of induction at day 50. Patients with minimal residual disease (MRD) at day 50 had significantly higher pDC levels than MRD-negative patients (P = 0.021). In B-precursor SR ALL patients, mDC levels but not pDC levels decreased during prolonged maintenance treatment, remaining reduced at the end of treatment (P = 0.032) and at 6 months post-treatment (P = 0.028). In conclusion, levels of DC in BM normalize quickly in children treated for ALL. Long-term treatment may more profoundly affect mDC subset, which shows reduced levels several months after treatment.

Discriminant function analysis as decision support system for the diagnosis of acute leukemia with a minimal four color screening panel and multiparameter flow cytometry immunophenotyping

Despite several recommendations for standardization of multiparameter flow cytometry (MFC) the number, specificity and combinations of reagents used by diagnostic laboratories for the diagnosis and classification of acute leukemias (AL) are still very diverse. Furthermore, the current diagnostic interpretation of flow cytometry readouts is influenced arbitrarily by individual experience and knowledge. We determined the potential value of a minimal four-color combination panel of 13 monoclonal antibodies (mAbs) with a CD45/sideward light scatter-gating strategy for a standardized MFC immunophenotyping of the clinically most relevant subgroups of AL. Bone marrow samples from 155 patients with acute myeloid leukemia (AML, n=79), B-cell precursor acute lymphoblastic leukemia (BCP-ALL, n=29), T-cell precursor acute lymphoblastic leukemia (T-ALL, n=12) and normal bone marrow donors (NBMD, n=35) were analyzed. A knowledge-based learning algorithm was generated by comparing the results of the minimal panel with the actual diagnosis, using discriminative function analysis. Correct classification of the test sample according to lineage, that is, BCP-ALL, T-ALL, AML and differentiation of NBMD was achieved in 97.2% of all cases with only six of the originally applied 13 mAbs of the panel. This provides evidence that discriminant function analysis can be utilized as a decision support system for interpretation of flow cytometry readouts.

Shape-selective extraction of PCBs and dioxins from fish and fish oil using in-cell carbon fractionation pressurized liquid extraction

This paper describes a new shape-selective, pressurized liquid extraction (PLE) procedure for extracting polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and PCBs from food and feed samples with an integrated carbon fractionation step. Initially this was done using specially designed inserts for 34-mL cells, but subsequently, large solid cells (66 mL) were machined to increase the capacity and robustness of the system. Depending on the carbon load and extraction solvent strength, the non-ortho PCBs were recovered either with the bulk of the PCBs or with the PCDD/Fs. The former is preferable if PCDD/Fs are the targets. In most cases, however, data are required for all indicator PCBs, WHO-PCBs, and PCDD/Fs. Therefore, further efforts focused on developing, optimizing, and validating a cost- and time-efficient PLE procedure that can extract these targets, separate non-ortho PCBs and PCDD/Fs from the bulk of the PCBs, allow gravimetric fat determinations, and requires a minimum of postextraction cleanup. The performance of the resulting procedure was assessed in experiments with a fish tissue reference material. The trueness of the WHO-PCB-TEQ, PCDD/F-TEQ, and total-TEQ data were -8, -5, and -7%, respectively, and the corresponding CVs were 1.5, 0.5, and 1.3%; within the limits set by the European community for gas chromatography-high-resolution mass spectrometry methods for food and feed control.

Quality assurance of the donation process

The quality of the organs harvested from a deceased donor is of critical importance for the outcome of the transplantations. During 2005, a quality assurance project was initiated to evaluate the donor management, harvest operation, and flow of information during the donation process. Three kinds of questionnaires were used in each donation. They were completed by the transplant coordinator, the harvesting surgeon, and the surgeons performing the liver and kidney transplantations. Feedback is given to the harvesting teams within 2 weeks after the procedures. The most important findings related to missed information concerning organ abnormalities or organ damage from the procurement operation. Procurement of organs from a deceased donor involves a complex chain of events. Based on our experiences in this 1-year project, we believe that standardized registration of the various parts of the process and structured feedback to the staff give possibilities to improve performance. After minor modifications, this method for quality assurance has been introduced as a permanent part of our donation procedure. We believe that this strategy can help to detect weaknesses and improve transplant outcomes.

Changing Donation Pattern in Central Sweden

Since 1990, the Organisation for Organ donation in Central Sweden has registered the numbers of donations at the various hospitals in the area. During this period, a significant decrease in donation rate was observed in the large hospitals, while there was an increase in donation rate in the smaller hospitals. Taken together, the small hospitals are now at least as important as the large hospitals. Possible reasons for the observed change in donation pattern are discussed.

Pre-hospital thrombolysis delivered by paramedics is associated with reduced time delay and mortality in ambulance-transported real-life patients with ST-elevation myocardial infarction

AIMS

There are sparse data on the impact of pre-hospital thrombolysis (PHT) in real-life patients. We therefore evaluated treatment delays and outcome in a large cohort of ambulance-transported real-life patients with ST-elevation myocardial infarction (STEMI) according to PHT delivered by paramedics or in-hospital thrombolysis.

METHODS AND RESULTS

Prospective cohort study used data from the Swedish Register of Cardiac intensive care on patients admitted to the coronary care units of 75 Swedish hospitals in 2001-2004. Ambulance-transported thrombolytic-treated patients younger than age 80 with a diagnosis of acute myocardial infarction were included. Patients with PHT (n=1690) were younger, had a lower prevalence of co-morbid conditions, fewer complications, and a higher ejection fraction (EF) than in-hospital-treated patients (n=3685). Median time from symptom onset to treatment was 113 min for PHT and 165 min for in-hospital thrombolysis. One-year mortality was 7.2 vs. 11.8% for PHT and in-hospital thrombolysis, respectively. In a multivariable analysis, after adjusting for baseline characteristics and rescue angioplasty, PHT was associated with lower 1-year mortality (odds ratio 0.71, 0.55-0.92, P=0.008).

CONCLUSION

When compared with regular in-hospital thrombolysis, pre-hospital diagnosis and thrombolysis with trained paramedics in the ambulances are associated with reduced time to thrombolysis by almost 1 h and reduced adjusted 1-year mortality by 30% in real-life STEMI patients.

Admission N-terminal pro-brain natriuretic peptide and its interaction with admission troponin T and ST segment resolution for early risk stratification in ST elevation myocardial infarction

OBJECTIVE

To assess the long term prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) on admission and its prognostic interaction with both admission troponin T (TnT) concentrations and resolution of ST segment elevation in fibrinolytic treated ST elevation myocardial infarction (STEMI).

DESIGN AND SETTING

Substudy of the ASSENT (assessment of the safety and efficacy of a new thrombolytic) -2 and ASSENT-PLUS trials.

PATIENTS

NT-proBNP and TnT concentrations were determined on admission in 782 patients. According to NT-proBNP concentrations, patients were divided into three groups: normal concentration (for patients < or = 65 years, < or = 184 ng/l and < or = 268 ng/l and for those > 65 years, < or = 269 ng/l and < or = 391 ng/l in men and women, respectively); higher than normal but less than the median concentration (742 ng/l); and above the median concentration. For TnT, a cut off of 0.1 microg/l was used. Of the 782 patients, 456 had ST segment resolution (< 50% or > or = 50%) at 60 minutes calculated from ST monitoring.

MAIN OUTCOME MEASURES

All cause one year mortality.

RESULTS

One year mortality increased stepwise according to increasing concentrations of NT-proBNP (3.4%, 6.5%, and 23.5%, respectively, p < 0.001). In receiver operating characteristic analysis, NT-proBNP strongly trended to be associated more with mortality than TnT and time to 50% ST resolution (area under the curve 0.81, 95% confidence interval (CI) 0.72 to 0.9, 0.67, 95% CI 0.56 to 0.79, and 0.66, 95% CI 0.56 to 0.77, respectively). In a multivariable analysis adjusted for baseline risk factors and TnT, both raised NT-proBNP and ST resolution < 50% were independently associated with higher one year mortality, whereas raised TnT contributed independently only before information on ST resolution was added to the model.

CONCLUSION

Admission NT-proBNP is a strong independent predictor of mortality and gives, together with 50% ST resolution at 60 minutes, important prognostic information even after adjustment for TnT and baseline characteristics in STEMI.

Outcome of ST-elevation myocardial infarction treated with thrombolysis in the unselected population is vastly different from samples of eligible patients in a large-scale clinical trial

BACKGROUND

Patients in clinical trials of fibrinolytic agents have been shown to be younger, less often female, and to have lower risk characteristics and a better outcome compared with unselected patients with ST-elevation myocardial infarction. However, a direct comparison of patients treated with fibrinolytic agents and not enrolled versus those enrolled in a trial, including a large number of patients, has not been performed.

METHODS

Prospective data from the Swedish Register of Cardiac Intensive Care on patients admitted with acute myocardial infarction treated with thrombolytic agents in 60 Swedish hospitals were linked to data on trial participants in the ASsessment of Safety and Efficacy of a New Thrombolytic (ASSENT)-2 trial of fibrinolytic agents. Baseline characteristics, treatments, and long-term outcome were evaluated in 729 trial participants (A2), 2048 nonparticipants at trial hospitals (non-A2), and 964 nonparticipants at other hospitals (non-A2-Hosp).

RESULTS

Nontrial patients compared with A2 patients were older and had higher risk characteristics and more early complications, although the treatments were similar. Patients at highest risk of death were the least likely to be enrolled in the trial. The 1-year mortality rate was 8.8% versus 20.3% and 19.0% (P <.001 for both) among A2 compared with non-A2 and non-A2-Hosp patients, respectively. After adjustment for a number of risk factors, the 1-year mortality rate was still twice as high in nontrial compared with A2 patients.

CONCLUSIONS

The adjusted 1-year mortality rate was twice as high in patients treated with fibrinolytic agents and not enrolled in a clinical trial compared with those enrolled. One major reason for the difference in outcome appeared to be the selection of less critically ill patients to the trial.

Admission Troponin T and measurement of ST-segment resolution at 60 min improve early risk stratification in ST-elevation myocardial infarction

AIMS

The prognostic value of admission troponin T (tnT) levels and the resolution of the ST-segment elevation in ST-elevation myocardial infarction (STEMI) is well established. However, the combination of these two early available markers for predicting risk has not been evaluated.

METHODS AND RESULTS

We evaluated 516 patients with fibrinolytic treated STEMI from the ASSENT-2 and ASSENT-PLUS studies, which had both admission tnT and ST-monitoring available. We used a prospectively defined cut-off value of tnT of 0.1microg/l. For ST-segment resolution, a cut-off of 50% measured after 60min was used. Both a tnT >/=0.1microg/l (n=116) and ST-segment resolution <50% (n=301) were related to higher one-year mortality, 13% vs 4% (P<0.001) and 8.4% vs 2.8% (P=0.009), respectively. In a multivariate analysis ST-segment resolution was and tnT showed a strong trend to be independently related to mortality. The combination of both further improved risk stratification. The one-year mortality in the group with elevation of tnT and without ST-segment resolution compared to the group without tnT elevation and with ST-segment resolution was 18.2% vs 2.8% (P<0.001).

CONCLUSIONS

Both tnT on admission and ST-segment resolution after 60min are strong predictors of one-year mortality. The combination of both gives additive early information about prognosis and further improves risk stratification.

Flow cytometric follow-up of minimal residual disease in bone marrow gives prognostic information in children with acute lymphoblastic leukemia

Using flow cytometry (FC) and live gate (LG) analysis we have followed levels of minimal residual disease (MRD) in the bone marrow (BM) of 70 consecutive patients with childhood acute lymphoblastic leukemia (59 B precursor ALL and 11 T-ALL) treated according to the Nordic (NOPHO-92) protocols. Thorough studies of B and T cell antigen expression patterns in normal BM performed during BIOMED 1 Concerted Action on MRD, made it possible to tailor individual protocols of marker combinations for follow-up in 97% of patients. In 12% of LG analyses, the numbers of cells exceeded 10(6) and in 82% exceeded 10(5), giving the sensitivity level of MRD detection 10(-5) and 10(-4), respectively. The median follow-up time was 53 months. Patients with MRD levels > or = 0.01% at follow-up time-points during and after first induction, and at the end of treatment had significantly lower disease-free survival by comparison to patients with MRD values <0.01%. Seven of nine patient with recurrence in the BM showed under treatment persisting MRD levels > or = 0.01% of BM cells. This was also observed in another two patients with infant leukemia who relapsed. In conclusion, the investigation of levels and the dynamics of MRD by sensitive and quantitative FC can provide a basis for further clinical studies for at least upgrading of therapy.

Method of determination of appropriate heat treatment of animal meal by immunoassay developed for detection of cooked beef: interlaboratory study

An interlaboratory trial was conducted for the validation of an enzyme-linked immunosorbent assay (ELISA) method for determination of appropriate heat treatment of animal meal. A commercially available ELISA test kit developed for the identification of beef in cooked food was used in the study. Twelve laboratories from 7 European countries examined 2 different analytical protocols to establish the most appropriate analytical method. Three different samples were used, 2 animal waste materials sterilized at 129 and 134 degrees C (wet conditions), respectively, and a meat and bone meal material processed at dry conditions (maximum temperature, 140 degrees C). Statistical evaluation applying t-statistics showed that the animal meal treated according to European legislation (>133 degrees C) was clearly distinguishable from the 2 other test materials at a 99% confidence level using both analytical protocols. This method can be considered as a complementary test to the immunoassay developed for the detection of pork in cooked food that is already applied in routine analysis for the surveillance of rendering plants.

Comparison of fat retainers in accelerated solvent extraction for the selective extraction of PCBs from fat-containing samples

Five types of fat retainers were investigated for the lipid-free extraction of PCBs from fat-containing matrixes using accelerated solvent extraction: florisil, basic alumina, neutral alumina, acidic alumina, and sulfuric acid-impregnated silica. All of the fat retainers generated fat-free extracts when the fat/fat retainer ratio was 1:40. Sulfuric acid-impregnated silica and florisil were the only retainers that gave completely clear extracts, and the former was the only not to show any reaction when treated with sulfuric acid after the extraction. Using sulfuric acid-impregnated silica as fat retainer, on-line cleanup of fat-containing matrixes was possible, as demonstrated for naturally contaminated fish meal as well as certified cod liver oil (CRM 349).

On-line clean-up of pressurized liquid extracts for the determination of polychlorinated biphenyls in feedingstuffs and food matrices using gas chromatography-mass spectrometry

This paper describes a fast and simple pressurized liquid extraction method for the determination of polychlorinated biphenyls (PCBs) in feedingstuffs and food matrices. The method is based on a simultaneous extraction/clean-up step requiring a minimum of sample handling. The final analysis was performed with gas chromatography-mass spectrometry. Seven PCBs (28, 52, 101, 118, 138, 153 and 180) were analyzed, all of which are indicator congeners that, according to European legislation should be included in the analytical monitoring program. The extracted matrices were spiked feed for poultry and two certified reference materials naturally contaminated with PCBs (cod-liver oil and milk powder), which showed excellent conformity with certified data.

Flow cytometry and allele-specific oligonucleotide PCR are equally effective in detection of minimal residual disease in ALL

The analysis of minimal residual disease (MRD) has assumed a growing role in the follow-up of patients with acute lymphoblastic leukemia (ALL). We have applied multiparameter flow cytometry (FC) with 'live-gate' analysis and allele-specific oligonucleotide (ASO)-PCR detecting leukemia-specific T cell receptor gamma and delta gene rearrangements for MRD follow-up in 30 ALL patients. The comparison of results obtained in 89 follow-up samples from 23 patients showed significantly consistent results in 70 samples (78%); (P < 0.001). Bone marrow samples taken during the first phase of treatment (during or immediately after induction) showed a lower level of consistency when compared to samples taken during later phases of treatment (69% vs 85% consistent results, respectively). Some of the discrepant results were due to low cellularity of the samples obtained for FC and some due to the presence of PCR inhibitors. Of 29 patients evaluated at the end of the induction treatment, 18 (62%) had detectable levels of MRD and six of these patients suffered relapse. In all these patients MRD levels by FC increased preceding relapse. Our results suggest that FC offers a MRD detection tool that can be easily applied in clinical practice and is as informative as molecular methods.

Analytical-scale microwave-assisted extraction

Microwave-assisted extraction (MAE) is a process of using microwave energy to heat solvents in contact with a sample in order to partition analytes from the sample matrix into the solvent. The ability to rapidly heat the sample solvent mixture is inherent to MAE and the main advantage of this technique. By using closed vessels the extraction can be performed at elevated temperatures accelerating the mass transfer of target compounds from the sample matrix. A typical extraction procedure takes 15-30 min and uses small solvent volumes in the range of 10-30 ml. These volumes are about 10 times smaller than volumes used by conventional extraction techniques. In addition, sample throughput is increased as several samples can be extracted simultaneously. In most cases recoveries of analytes and reproducibility are improved compared to conventional techniques, as shown in several applications. This review gives a brief theoretical background of microwave heating and the basic principles of using microwave energy for extraction. It also attempts to summarize all studies performed on closed-vessel MAE until now. The influences of parameters such as solvent choice, solvent volume, temperature, time and matrix characteristics (including water content) are discussed.

Comparison of two extraction methods independently developed on two conceptually different automated supercritical fluid extraction systems for the determination of polychlorinated biphenyls in sediments

Two extraction methods that independently have been developed on conceptually different automated supercritical fluid extraction systems, ISCO SFX 3560 (syringe pump and liquid trapping) and Hewlett-Packard 7680T SFE (reciprocating pump and solid-phase trapping), were compared for the extraction of polychlorinated biphenyls from two Swedish sediments. The results demonstrated that the high-temperature ISCO method in some cases yields a more exhaustive extraction, but also less clean extracts due to co-extraction of unwanted matrix components which are all present in the trapping solvent. The medium-temperature Hewlett-Packard method may sometimes cause problems with quantitative recoveries, but on the other hand it yields very clean extracts due to the extra selectivity resulting from collection on a solid-phase trap.

Introducing selective supercritical fluid extraction as a new tool for determining sorption/desorption behavior and bioavailability of persistent organic pollutants in sediment

This review article intends to introduce the possibility of utilizing selective supercritical fluid extraction (SFE) as a tool to study sorption/desorption processes and bioavailability of persistent organic pollutants (POP) in sediment. Sorption/desorption behavior and bioavailability studies of POPs is a large research area, but still many unsolved problems exists. Therefore novel approaches to investigate mechanistic behavior of POPs in sediments are needed. Present literature on SFE points to the fact that selective SFE measurements can improve our knowledge, and recent investigations have been performed that demonstrate this. Results obtained with selective SFE can be connected to desorption of POPs in sediments under natural conditions in aquatic ecosytems. The ultimate goal is to use selective SFE as a way to determine the bioavailable fraction present within a matrix. A few preliminary results are presented here which may serve as a starting point for future studies.

BIOMED-1 concerted action report: flow cytometric characterization of CD7+ cell subsets in normal bone marrow as a basis for the diagnosis and follow-up of T cell acute lymphoblastic leukemia (T-ALL)

The European BIOMED-1 Concerted Action was initiated in 1994 to improve and standardize the flow cytometric detection of minimal residual disease (MRD) in acute leukemia (AL). Three different protocols were defined to identify the normal subsets of B, T and myeloid cells in bone marrow (BM), and were applied to the different types of AL in order to study aberrant immunophenotypes. Using sensitive acquisition methods ('live gate') T cell subsets in normal BM could be identified with five triple-stains: CD7/CD5/CD3, CD7/CD4/CD8, CD7/CD2/CD3, CD7/CD38/CD34 and TdT/CD7/surface or cytoplasmic (cy)CD3 (antibodies conjugated with FITC/PE/PECy5 or PerCP, respectively). The identification of T cell subsets in BM allowed definition of 'empty spaces' (ie areas of flow cytometric plots where normally no cells are found). All studied T-ALL cases (n = 65) were located in 'empty spaces' and could be discriminated from normal T cells. The most informative triple staining was TdT/CD7/cyCD3, which was aberrant in 91% of T-ALL cases. In most cases, two or more aberrant patterns were found. Apparently the immunophenotypes of T-ALL differ significantly from normal BM T cells. This is mostly caused by their thymocytic origin, but also the neoplastic transformation might have affected antigen expression patterns. Application of the five proposed marker combinations in T-ALL contributes to standardized detection of MRD, since cells persistent or reappearing in the 'empty spaces' can be easily identified in follow-up BM samples during and after treatment.

Utilization of fat retainers in supercritical fluid extraction for the selective extraction of polychlorinated biphenyls from a model fat sample

Two common fat retainers used in supercritical fluid extraction--basic alumina and the silica based adsorbent Florisil--were investigated using lard fat as model material. With a fat retainer in the extraction cell it was possible to obtain fat-free time windows. Activation by heating did not influence the length of the time windows, while deactivation of the retainers with 10% water (w/w) drastically decreased the fat retaining capabilities. The influence of modifier addition was also investigated. Finally, a method was developed, where basic alumina was utilized to selectively extract polychlorinated biphenyls (PCBs) from a model fat sample, containing PCBs, triglycerides and phospholipids. The PCBs could be quantitatively extracted in a totally fat-free time window.