Impact of ABC pathway adherence in high-risk patients with atrial fibrillation: an analysis from the ESC-EHRA EORP-AF long-term general registry

Background

The impact of Atrial Fibrillation Better Care (ABC) pathway adherence among high-risk subgroups of patients with atrial fibrillation (AF), ie. those with chronic kidney disease (CKD), advanced age and/or prior thromboembolism remains unknown. We evaluated the impact of ABC pathway adherence on clinical outcomes in these high-risk AF patients.

Methods

The EORP-AF General Long-Term Registry is a prospective, observational registry from 250 centres across 27 European countries. High-risk patients were defined as those with either CKD (eGFR <60 mL/min/1.73 m2), older age (≥75 years) and/or prior thromboembolism. The primary outcome was a composite event of all-cause death, any thromboembolism and acute coronary syndrome, evaluated according to ABC pathway adherence.

Results

A total of 6646 patients with AF were included (median age was 70 [IQR 61–77] years; 40.2% females). There were 3304 (54.2%) `high risk' patients with either CKD (n=1750), older age (n=2236) or prior thromboembolism (n=728). Among these there were 924 (28.0%) managed as adherent to ABC.

At 2-year follow-up, a total of 966 (14.5%) patients reported the primary outcome. The incidence of the primary outcome was significantly lower in high-risk patients managed as adherent to ABC pathway (IRR 0.53 [95% CI, 0.43–0.64]). Consistent results were obtained in the individual subgroups [Table]. Using multivariable Cox proportional hazards analysis, ABC adherence in the high-risk cohort was independently associated with a lower risk of primary outcome (aHR 0.64 [95% CI, 0.51–0.80]), as well as in the CKD (aHR 0.51 [95% CI, 0.37–0.70]) and elderly subgroups (aHR 0.69 [95% CI, 0.53–0.90]). Overall, there was greater reduction in the risk of primary outcome as more ABC criteria were fulfilled, both in the overall high-risk patients, as well as in the individual subgroups [Figure].

Conclusion

In a large, contemporary European AF cohort there was a significant proportion of high-risk patients. Among these, a low prevalence of integrated care, as assessed by adherence to ABC pathway, was found. Nonetheless, a clinical management adherent to the ABC pathway was associated with a significant reduction in the risk of adverse outcomes, the benefits of which were more significant with increasing number of ABC criteria adherent.

Funding Acknowledgement

Type of funding sources: None.

ABC adherence and impact of optimal medical therapy in heart failure patients with atrial fibrillation

Background

Heart failure (HF) has close association with atrial fibrillation (AF). The ESC guideline recommended Atrial fibrillation Better care (ABC) pathway aims to reduce major cardiovascular adverse outcomes with an integrated care approach. Optimal medical treatment (OMT) represents the cornerstone in HF management.

Purpose

To investigate the variables affecting OMT treatment and its impact, in conjunction with ABC pathway adherence (vs non-adherence, ie.no ABC), in a large contemporary cohort of European AF patients with HF enrolled in the ESC-EHRA EORP-AF General Long-Term Registry.

Methods

OMT was defined as treatment with Angiotensin-converting-enzyme inhibitors (ACE-i)/ Angiotensin receptor blockers (ARBs) with Beta-Blockers and/or Mineralocorticoid receptor antagonists (MRAs), and compared to non-OMT adherence (“no OMT”). A logistic regression analysis explored factors associated with OMT adherence. We identified three patient groups: (i) HF with no OMT/no ABC; (ii) HF with OMT/no ABC; (iii) HF with OMT/ABC. Primary outcome was a composite outcome of all-cause death and major adverse cardiac events (MACE).

Results

Among the original 11096 patients enrolled, 9857 (88.8%) were included in this analysis. Among these, 3819 (38.7%) had HF. Compared to non HF patients, those with HF were older, more likely female, had more comorbidities and higher thromboembolic risk. OMT prevalence was 2228/3819 (58.3%), while ABC adherence was 23.3%.

On logistic multivariable regression, increasing age, higher BMI and higher frailty index were associated with OMT adherence, while male sex, anemia, renal disease and EHRA II–IV were inversely associated with OMT adherence. According to three HF groups, the rates of composite outcome progressively decreased (HF with no OMT/no ABC 26.4%; HF with OMT/no ABC 24%, HF with OMT/ABC 19%; p<0.001). Kaplan Meier curve showed progressively lower cumulative risk for the composite outcome across the three groups with the lowest risk among HF patients with OMT/ABC (Log-rank: p=0.002) [Figure 1]. Adjusted Cox regression analysis showed that when compared to HF with no OMT/no ABC group, there was a progressively lower risk with OMT and/or ABC adherence (HF with OMT/no ABC: HR 0.81 [95% CI, 0.64–1.02]; HF with OMT/ABC: HR 0.68 [95% CI, 0.5–0.92]).

Conclusions

After two years of follow-up, in a large contemporary cohort of European AF patients with HF, OMT adherence was suboptimal, being influenced by several clinical factors, determining a low adherence to the ABC pathway. OMT alone showed a non-significant reduction in composite outcome events. Conversely HF patients managed with OMT in the context of ABC pathway adherence showed the best reduction in risk of adverse outcomes.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022). - I agree that this information can be anonymised and then used for statistical purposes only

Features of clinical complexity in european patients with atrial fibrillation: a report from the ESC-EHRA EORP atrial fibrillation general long-term registry

Introduction

There is increasing concern regarding the burden of clinical complexity, beyond thromboembolic risk, in patients with atrial fibrillation (AF). Also, clinical complexity is heterogenous and entails differential impact on the patients' clinical course.

Purpose

To explore different complexity features in AF patients in determining differences in clinical management and outcomes.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Features of complexity were analysed in the context of the following high-risk groups: i) only CHA2DS2-VASc ≥2; ii) history of stroke/bleeding; iii) chronic kidney disease (creatinine clearance <60 mL/min, CKD); iv) frail (frailty index ≥0.25); v) ≥2 criteria. All these groups were compared to a low-risk group (CHA2DS2-VASc 0–1). We examined use of oral anticoagulant (OAC) and the risks of a composite outcome of all-cause death and major adverse cardiovascular events.

Results

A total of 10285 patients (mean [SD] age 68.8 [11.5] years, 4107 [39.9%] females) were included in the analysis. Of these, 3944 (38.3%) had only CHA2DS2-VASc ≥2; 412 (4.0%); history of stroke/bleeding; 1480 (14.4%) CKD; 1007 (9.8%) were frail; 1315 (12.8%) had ≥2 criteria; and 2127 (20.7%) were low-risk. After adjustment for age, sex, type of AF and EHRA score, compared to low-risk patients, all the other groups were associated with OAC prescription but with progressively lower odds ratio, while those ≥2 criteria which were least likely prescribed with OAC (Table 1).

After a mean (SD) 634.5 (223.0) days of follow-up, a total of 1432 events were recorded. After adjustment for confounders, Cox regression analysis found that all the complexity groups were associated with a higher risk of the composite outcome across the groups (Figure 1). In patients with available data about ABC (Atrial fibrillation Better Care) pathway adherence, the latter adherence was associated a significant incidence rate reduction (IRR) compared to non-ABC adherence in those with ≥2 criteria of clinical complexity (IRR 0.46, 95% CI 0.30–0.71), and in the CKD complexity group (IRR 0.57, 95% CI 0.41–0.81).

Conclusions

In a large contemporary cohort of European AF patients, features of clinical complexity affect differently prescriptions of OAC. All the subgroups of clinical complexity were associated with a higher risk of adverse outcomes, which were reduced by adherence to ABC pathway.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and PfizerAlliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022).

Impact of the atrial fibrillation better care pathway in clinically complex patients with atrial fibrillation: a report from the ESC-EHRA EORP-AF General Long-Term Registry

Background

Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The “Atrial fibrillation Better Care” (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We analyzed the impact of the ABC pathway in a contemporary cohort of clinically complex AF patients.

Methods

From the ESC-EHRA EORP-AF General Long-Term Registry, we analyzed clinically complex AF patients, defined as the presence of frailty (according to a 40-items Frailty Index), multimorbidity and/or polypharmacy. A K-medoids cluster analysis was performed to identify different groups of clinical complexity. The impact of an ABC-adherent approach on the risk of all-cause death, major adverse cardiovascular events (MACEs) and the composite outcome of all-cause death and MACE was analyzed through Cox-regression analyses, and delay of event (DoE) analyses; number needed to treat (NNT) was also estimated at 1 year of follow-up.

Results

Among 9,966 AF patients, 8,289 (92.3%) were clinically complex. Risk of all outcomes was higher among clinically complex patient. Adherence to the ABC pathway in the clinically complex group reduced the risk of all-cause death (adjusted HR [aHR]: 0.71, 95% CI 0.57–0.89), major adverse cardiovascular events (MACEs, aHR: 0.68, 95% CI 0.53–0.87) and composite outcome (aHR: 0.69, 95% CI: 0.57–0.84). Using cluster analysis, we identified a high clinical complexity group of AF patients. Adherence to the ABC pathway was associated with a significant reduction in the risk of death (aHR: 0.73, 95% CI 0.55–0.96) and composite outcome (aHR: 0.69, 95% CI 0.57–0.84) in the high-complexity cluster; similar trends were observed for MACEs. In DoE analyses, an ABC-adherent approach resulted in significant gains in event-free survival for all-cause death (Figure 1), MACEs, and composite outcome in clinically complex patients. Based on absolute risk reduction at 1 year of follow-up, the NNTs for ABC pathway adherence was 24 for all-cause death, 31 for MACEs and 20 for the composite outcome.

Conclusions

An ABC-adherent approach reduces the risk of major outcomes in clinically complex AF patients. Ensuring adherence to the ABC pathway is essential to improve clinical outcomes amongst clinically complex AF patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Since the start of EORP, several companies have supported the programme with unrestricted grants.

Molecular mechanism of acetylsalicylic acid in improving learning and memory impairment in APP/PS1 transgenic mice by inhibiting the abnormal cell cycle re-entry of neurons

Alzheimer’s disease (AD) is a neurodegenerative disorder accompanied by the loss and apoptosis of neurons. Neurons abnormally enter the cell cycle, which results in neuronal apoptosis during the course of AD development and progression. However, the mechanisms underlying cell cycle re-entry have been poorly studied. Using neuroblastoma (N) 2aSW and APP/PS1 transgenic (Tg) mice as in vitro and in vivo AD models, we found that the expression of cyclin-dependent kinase (CDK)1/2/4 and cyclin A2/B1/D3/E1 was increased while the protein expression of p18 and p21 was decreased, which led to enhanced cell cycle re-entry in a β-amyloid protein (Aβ)-dependent mechanism. By preparing and treating with the temperature-sensitive chitosan-encapsulated drug delivery system (CS), the abnormal expression of CDK1/2/4, cyclin A2/B1/D3/E1 and p18/21 was partially restored by acetylsalicylic acid (ASA), which decreased the apoptosis of neurons in APP/PS1 Tg mice. Moreover, CDK4 and p21 mediated the effects of ASA on activating transcription factor (TF) EB via peroxisome proliferator-activated receptor (PPAR) α, thus leading to the uptake of Aβ by astrocytes in a low-density lipoprotein receptor (Ldlr)-dependent mechanism. Moreover, the mechanisms of Aβ-degrading mechanisms are activated, including the production of microtubule-associated protein light chain (LC) 3II and Lamp2 protein by ASA in a PPARα-activated TFEB-dependent manner. All these actions contribute to decreasing the production and deposition of Aβ, thus leading to improved cognitive decline in APP/PS1 Tg mice.

Ablation Index-guided 50W ablation for left atrial posterior wall isolation compared with lower powers: feasibility and lesion level analysis

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Groupe de Rythmologie de la Société Française de Rythmologie

Background 

Posterior Wall Isolation (PWI) is increasingly performed for Atrial Fibrillation (AF). The use of Ablation Index (AI)-guided 50W ablation for PWI has not been described, nor the interplay between ablation parameters at this power when compared to lower powers. 

Methods 

40 consecutive AF patients (26 males, 65.5 ± 10.0 years. 95% non-paroxysmal AF) underwent PWI following pulmonary vein isolation. A roof line and floor line were created with point-by-point ablation, targeting a contact force (CF) of 10-30g, AI 550-600 on the roof and 400-450 on the floor, and inter-tag distance of <6mm. 35-40W powers were used for the first 20 patients, and 50W used for the next 20. Generator impedance was monitored in real time for each lesion. Ablation inside the box was delivered in case of failure of first pass isolation (FPI). All VisiTags (n = 959) were analyzed retrospectively. 

Results 

PWI was successful in 19(95%) of the 35-40W group and in all 20 patients in the 50W group, with FPI seen in 8(40%) and 10(50%) respectively, p = 0.53. The mean CF and number of RF applications on the roof. floor and inside the box were similar between the two groups. Ablation time per lesion (10.4 [8.8-12.5]sec) and total ablation time per patient (3.84[3.34-4.66] min) were shorter in the 50W group as compared to 35-40W (13.0 [11.6-16.2] sec and 5.86 [4.23-7.73] min respectively), p < 0.005. The mean AI and Impedance Drop were larger in the 50W group (Table). There was no steam pop observed in any of the 959 radiofrequency applications. 

Conclusion 

Ablation Index guided 50W ablation has a very high success rate for posterior wall isolation with shorter ablation times and higher impedance drop compared to conventional powers. Steam pops may be avoidable by targeting CF < 30g, and by monitoring impedance in real-time. 50W Group(N = 458) 35-40W Group(N = 501) p-value Number of lesions (s, IQR)Roof lineFloor lineAdditional ablation inside box 21.5 [19.5-26.3]7.0 [5.8-9.0]13.0 [10.8-14.3]6.0 [6.0-6.8] 24.0 [20.8-29.5]8.0 [6.0-10.0]12.5 [10.8-14.0]5.5 [2.8-9.0] 0.330.180.850.59 Ablation Time per lesion (s, IQR)Roof lineFloor lineAdditional ablation inside box 10.4 [8.8-12.5]13.0 [10.9-16.0]9.9 [8.7-11.4]8.1 [6.9-9.0] 13.0 [11.6-16.2]14.5 [12.4-19.0]12.7 [11.4-15.9]11.8 [10.6-14.0] <0.005<0.005<0.005<0.005 Total RF Time (min, IQR)Roof lineFloor lineAdditional ablation inside box 3.84 [3.34-4.66]1.54 [1.15-1.90]2.06 [1.68-2.54]0.79 [0.65-1.07] 5.86 [4.23-7.73]1.98 [1.62-2.59]2.78 [2.28-3.25]1.07 [0.59-1.42] < 0.0050.0190.0090.50 Impedance Drop (ohms, IQR)Roof lineFloor lineAdditional ablation inside box 7.4 [5.2-10.3]8.7 [6.1-11.3]6.9 [5.0-10.1]7.1 [5.4-9.8] 6.9 [4.8-9.7]7.5 [5.1-10.0]6.0 [4.2-8.3]8.3 [5.8-10.9] 0.0070.04< 0.0050.17 Contact Force (g, IQR)Roof lineFloor lineAdditional ablation inside box 21.1 [14.5-30.3]23.9 [17.8-32.7]19.2 [13.2-25.3]25.5 [18.5-36.9] 21.2 [14.9-28.1]24.3 [17.2-30.3]19.0 [14.1-25.0]23.1 [16.9-31.7] 0.560.450.870.21 Ablation Index (IQR)Roof lineFloor lineAdditional ablation inside box 471 [441-519]560 [509-571]453 [436-475]461 [430-488] 461 [434-493]502 [466-541]446 [426-464]455 [434-478] < 0.005< 0.005< 0.0050.59 Lesion level analysis for Posterior Wall Isolation

The Atrial Fibrillation Better Care (ABC) pathway in atrial fibrillation: a systematic review and meta-analysis of 285,000 patients

Funding Acknowledgements

Type of funding sources: None.

Background

The ‘Atrial Fibrillation Better Care’ (ABC) pathway has been recently proposed as a holistic approach for the comprehensive management of patients with Atrial Fibrillation (AF), standing on three main pillars: ‘A’ Avoid stroke (with Anticoagulants); ‘B’ Better symptom management; ‘C’ Cardiovascular and Comorbidity management. The ABC pathway is now recommended in several clinical guidelines, including the recent European Society of Cardiology (ESC) AF management guidelines. We performed a systematic review of the current evidence for use of the ABC pathway on clinical outcomes.

Methods

We performed a systematic review and meta-analysis according to PRISMA Guidelines. Pubmed and EMBASE were searched for studies reporting the prevalence of ABC pathway adherent management in AF patients, and its impact on clinical outcomes (all-cause death, cardiovascular death, stroke, and major bleeding). Metanalysis of odds ratio (OR) was performed with random-effect models; subgroup analysis and meta-regression were performed to account for heterogeneity; a CHA2DS2-VASc-stratified sensitivity analysis was also performed.

Results

Among 2862 records retrieved from the literature search, 8 studies were included. The pooled prevalence of ABC adherent management was 21% (95% confidence intervals (CI), 13-34%), with a high grade of heterogeneity; in a multivariable meta-regression model, adherence to each criteria of the ABC pathway explained most part of the heterogeneity (R2 = 98.9%). Patients treated according to the ABC pathway showed a lower risk of all-cause death (OR:0.42, 95%CI 0.31-0.56), cardiovascular death (OR:0.37, 95%CI 0.23-0.58), stroke (OR:0.55, 95%CI 0.37-0.82) and major bleeding (OR:0.69, 95%CI 0.51-0.94), with moderate heterogeneity. Meta-regressions showed that the increasing prevalence of diabetes mellitus, coronary artery disease, chronic heart failure and history of stroke were associated with a reduced effectiveness of the ABC pathway for all-cause and cardiovascular death; each comorbidity was able to explain a significant proportion of heterogeneity at univariate meta-regression. Conversely, longer follow-up time was associated with more effectiveness of the ABC pathway for all outcomes. Adherence to ABC pathway was associated with a progressively greater reduction of the all-cause death risk amongst patients with higher CHA2DS2-VASc scores; no difference in ABC pathway effectiveness was found across CHA2DS2-VASc strata for CV death and stroke occurrence.

Conclusions

Adherence to the ABC pathway was suboptimal, being adopted in 1 in every 5 patients. Adherence to the ABC pathway was associated with a reduction in the risk of major adverse outcomes. Our data supports extensive application of the ABC pathway for the management of AF. Abstract Figure.

Novel tool for predicting residual stroke risk in atrial fibrillation: mCARS

Funding Acknowledgements

Type of funding sources: None.

Background

Recently, CARS was proposed to predict 1-year absolute stroke risk in non-anticoagulated patients with atrial fibrillation (AF). We aimed to determine whether a modified CARS (mCARS) may be used to assess the residual stroke risk in anticoagulated AF patients.

Methods

We studied patient-level data of anticoagulated AF patients from the real-world Murcia AF Project and AMADEUS clinical trial. Individual mCARS was estimated for each patient using an estimated 64% risk reduction with anticoagulation.

Results

3,503 patients were included (2,205 [62.9%] clinical trial and 1,298 [37.1%] real-world). In the clinical trial cohort, the median age was 71 (IQR 65-77) and CHA2DS2-VASc score 3 (IQR 2-4). In the real-world cohort, the median age was 76 (IQR 70-81) and CHA2DS2-VASc score 4 (IQR 3-5).

At 1-year, there were 40 and 31 stroke events in the clinical trial and real-world cohorts, respectively. Average predicted residual stroke risk by mCARS was identical to actual stroke risk (1.8 [±1.8%] vs. 1.8% [95% CI, 1.3-2.4]) in the clinical trial, and broadly similar in the real-world (2.1 [±1.9%] vs. 2.4% [95% CI, 1.6-3.4]). Additionally, these values were comparable across the subgroups stratified by CHA2DS2-VASc score in both cohorts.

AUCs of mCARS for prediction of stroke events in the clinical trial and real-world were 0.678 (95% CI, 0.598-0.758) and 0.712 (95% CI, 0.618-0.805), respectively. In an exploratory analysis, we found that mCARS was able to refine stroke risk estimation for each point of the CHA2DS2-VASc score in both cohorts.

Conclusion

Personalised residual 1-year absolute stroke risk in anticoagulated AF patients may be estimated using mCARS. Such patients with high residual stroke risk may benefit from more aggressive interventions and follow-up. Absolute 1-year stroke risk Clinical Trial Real-World Median (IQR) Range Median (IQR) Range CHA2DS2-VASc score 0 NA 0.9 (0.6 - 1.3) 0.2 - 1.4 CHA2DS2-VASc score 1 1.1 (0.7 - 1.4) 0.2 - 2.0 1.4 (0.9 - 1.7) 0.2 - 13.0 CHA2DS2-VASc score 2 2.0 (1.5 - 2.4) 0.3 - 10.8 2.1 (1.5 - 2.6) 0.3 - 10.8 CHA2DS2-VASc score 3 2.6 (2.1 - 3.4) 0.4 - 13.3 2.8 (2.5 - 3.4) 0.9 - 13.3 CHA2DS2-VASc score 4 3.6 (2.8 - 5.6) 0.3 - 18.1 3.9 (3.3 - 5.0) 1.1 - 21.0 CHA2DS2-VASc score 5 6.7 (3.6 - 14.0) 1.9 - 20.9 4.8 (3.9 - 12.2) 1.2 - 21.0 CHA2DS2-VASc score 6 13.6 (5.5 - 15.8) 2.4 - 21.8 12.8 (4.8 - 16.7) 2.2 - 21.8 CHA2DS2-VASc score 7 15.7 (14.5 - 17.4) 4.5 - 21.9 15.6 (5.9 - 17.5) 4.1 - 23.5 CHA2DS2-VASc score 8 16.5 (14.0 - 18.5) 13.1 - 20.3 16.9 (15.7 - 19.5) 13.6 - 21.0 IQR, interquartile range; NA, not applicable.

The roles of prostaglandin F2 in regulating the expression of matrix metalloproteinase-12 via an insulin growth factor-2-dependent mechanism in sheared chondrocytes

Osteoarthritis (OA) was recently identified as being regulated by the induction of cyclooxygenase-2 (COX-2) in response to high fluid shear stress. Although the metabolic products of COX-2, including prostaglandin (PG)E₂, 15-deoxy-Δ^12,14-PGJ₂ (15d-PGJ₂), and PGF_2α, have been reported to be effective in regulating the occurrence and development of OA by activating matrix metalloproteinases (MMPs), the roles of PGF_2α in OA are largely overlooked. Thus, we showed that high fluid shear stress induced the mRNA expression of MMP-12 via cyclic (c)AMP- and PGF_2α-dependent signaling pathways. Specifically, we found that high fluid shear stress (20 dyn/cm²) significantly increased the expression of MMP-12 at 6 h ( > fivefold), which then slightly decreased until 48 h ( > threefold). In addition, shear stress enhanced the rapid synthesis of PGE₂ and PGF_2α, which generated synergistic effects on the expression of MMP-12 via EP2/EP3-, PGF2α receptor (FPR)-, cAMP- and insulin growth factor-2 (IGF-2)-dependent phosphatidylinositide 3-kinase (PI3-K)/protein kinase B (AKT), c-Jun N-terminal kinase (JNK)/c-Jun, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-activating pathways. Prolonged shear stress induced the synthesis of 15d-PGJ₂, which is responsible for suppressing the high levels of MMP-12 at 48 h. These in vitro observations were further validated by in vivo experiments to evaluate the mechanisms of MMP-12 upregulation during the onset of OA by high fluid shear stress. By delineating this signaling pathway, our data provide a targeted therapeutic basis for combating OA.

Shear stress induces cartilage cells to produce hormone-like molecules that activate the expression of an enzyme implicated in the development of osteoarthritis, a degenerative joint disease. Pu Wang and colleagues from Northeastern University in Shenyang, China, exposed human cartilage cells to high fluid shear stress for up to 2 days. This frictional strain rapidly stimulated the production of a proinflammatory enzyme, COX-2, which in turn promoted the synthesis of two hormone-like substances, called prostaglandins. These prostaglandins, PGE₂ and PGF_2α, then induced expression of an osteoarthritis-associated enzyme called MMP-12 that destroys the supporting structure that surrounds cartilage cells. The researchers, working both in human cells and in mouse models, further delineated several intermediate signaling molecules in the pathway linking shear stress with MMP-12 activation, thereby revealing several new potential drug targets for combating osteoarthritis in patients.

Erythrocyte membrane-encapsulated celecoxib improves the cognitive decline of Alzheimer's disease by concurrently inducing neurogenesis and reducing apoptosis in APP/PS1 transgenic mice

Alzheimer's disease (AD) is characterized by the loss of neurogenesis and excessive induction of apoptosis. The induction of neurogenesis and inhibition of apoptosis may be a promising therapeutic approach to combating the disease. Celecoxib (CB), a cyclooxygenase-2 specific inhibitor, could offer neuroprotection. Specifically, the CB-encapsulated erythrocyte membranes (CB-RBCMs) sustained the release of CB over a period of 72 h in vitro and exhibited high brain biodistribution efficiency following intranasal administration, which resulted in the clearance of aggregated β-amyloid proteins (Aβ) in neurons. The high accumulation of the CB-RBCMs in neurons resulted in a decrease in the neurotoxicity of CB and an increase in the migratory activity of neurons, and alleviated cognitive decline in APP/PS1 transgenic (Tg) mice. Indeed, COX-2 metabolic products including prostaglandin E2 (PGE₂) and PGD₂, PGE₂ induced neurogenesis by enhancing the expression of SOD2 and 14-3-3ζ, and PGD₂ stimulated apoptosis by increasing the expression of BIK and decreasing the expression of ARRB1. To this end, the CB-RBCMs achieved better effects on concurrently increasing neurogenesis and decreasing apoptosis than the phospholipid membrane-encapsulated CB liposomes (CB-PSPD-LPs), which are critical for the development and progression of AD. Therefore, CB-RBCMs provide a rational design to treat AD by promoting the self-repairing capacity of the brain.

The level of mercury contamination in mariculture sites at the estuary of Pearl River and the potential health risk

In the present study, the Hg contamination in mariculture sites located at the estuary of Pearl River was to investigate with an attempt to analyse associated health risks of dietary exposure to both total mercury (THg) and methyl mercury (MeHg) in cultured fish and shellfish. The highest total mercury concentration (7.037 ± 0.556 ng L^-1) of seawater was observed at Zhuhai Estuary. The Hg concentrations of sediment in Guishan Island were significantly higher (p < 0.05) than in Daya Bay (away from the Pearl River). Besides, the both THg and MeHg levels in sediment at mariculture sites were higher (p < 0.05) than corresponding reference sites. It was attributed to the fact that mariculture activities increased Hg loading and promoted MeHg production. The vertical distribution of Hg in sediment cores demonstrated that mercury methylation mostly occurred at the sediment-water interface. Results of health risk assessments showed that fish consumption would impose a higher risk to children but less to adults, while shellfish produced in the studied area was safe for consumption.

Conservation and population genetic diversity of Curcuma wenyujin (Zingiberaceae), a multifunctional medicinal herb

Curcuma wenyujin is an important multifunctional medicinal herb in China. Currently, populations of C. wenyujin are decreasing, and wild individuals have almost disappeared from their natural habitats. Moreover, little is known regarding the molecular characteristics of this plant. In this study, we investigated the genetic diversity and variation of five populations of C. wenyujin, using ran-dom amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. We found that the percentages of polymorphic loci (PPL) at the species level (98.25% by RAPD and 100% by ISSR) were significantly higher than those at the population level (66.32% by RAPD and 67.14% by ISSR). The highest values of PPL, expected heterozygosity, and Shannon's information index were in Pop1, while the lowest values were in Pop2. Both DNA markers revealed a short genetic distance between Pop1 and Pop2 (0.1424 by RAPD and 0.1904 by ISSR). Phylogenetic trees produced similar results, with Pop1, Pop2, and Pop5 in one group and Pop3 and Pop4 in another. There were no significant correlations between their genetic distances and their geographical distances. The highest genetic diversity was in Pop1 and the lowest was in Pop2, and genetic diversity at the species level was relatively low, but much higher than that at the population level. We recommended the establishment of a germplasm bank, in situ con-servation, and propagation of wild individuals. The present study will improve the evaluation, protection, and utilization of the population resources of C. wenyujin.

An esophagogastroduodenal anastomosis model for esophageal adenocarcinogenesis in rats and enhancement by iron overload

The aim of this study is to establish a good animal model for esophageal adenocarcinoma (EAC) and to test the hypothesis that iron over-nutrition enhances EAC formation. With rats, esophagogastroduodenal anastomosis (EGDA) was accomplished by anastomosing the duodenum to the gastroesophageal junction. Iron supplementation was given by i.p. injection of iron dextran (4 mg Fe/kg/week). This model mimics the development of human EAC by introducing mixed reflux of gastric and duodenal contents. At 40 weeks after surgery, the body weight, food intake, hemoglobin, total serum iron, transferrin saturation, serum albumin, and plasma levels of alpha-tocopherol, gamma-tocopherol and retinol of the EGDA rats were not significantly different from those of the non-operated controls. The animals generally had only mild esophagitis, except that the area surrounding the anastomosis opening had more severe esophagitis. Columnar-lined esophagus (CLE), CLE with dysplasia, and EAC were diagnosed in 53.5, 34.9 and 25.6%, respectively, of the 43 rats. Intraperitoneal iron supplementation significantly enhanced esophageal lesions with CLE, CLE with dysplasia, and EAC to 78.0, 53. 7 and 53.7%, respectively, of the 41 rats. All the tumors were well-differentiated mucinous adenocarcinomas at the squamocolumnar junction area, where most iron deposition was observed. EGDA avoids nutritional problems seen in other animal models for EAC. We believe that direct anastomosis of squamous epithelium to columnar epithelium and mixed reflux of gastric and duodenal contents lead to the formation of CLE and EAC. With this model, we demonstrated that iron supplementation significantly enhanced EAC formation, suggesting that iron over-nutrition could also be a risk factor for human EAC.