Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Predicting primate tongue morphology based on geometrical skull matching. A first step towards an application on fossil hominins

As part of a long-term research project aiming at generating a biomechanical model of a fossil human tongue from a carefully designed 3D Finite Element mesh of a living human tongue, we present a computer-based method that optimally registers 3D CT images of the head and neck of the living human into similar images of another primate. We quantitatively evaluate the method on a baboon. The method generates a geometric deformation field which is used to build up a 3D Finite Element mesh of the baboon tongue. In order to assess the method's ability to generate a realistic tongue from bony structure information alone, as would be the case for fossil humans, its performance is evaluated and compared under two conditions in which different anatomical information is available: (1) combined information from soft-tissue and bony structures; (2) information from bony structures alone. An Uncertainty Quantification method is used to evaluate the sensitivity of the transformation to two crucial parameters, namely the resolution of the transformation grid and the weight of a smoothness constraint applied to the transformation, and to determine the best possible meshes. In both conditions the baboon tongue morphology is realistically predicted, evidencing that bony structures alone provide enough relevant information to generate soft tissue.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Carbon Stable Isotope Ratio of Dissolved Organic Matter as a Tool To Identify Its Sources and Transformations in a Tropical Montane Forest in Ecuador

Dissolved organic matter (DOM) contributes to forest C cycling. We assessed temporal variability, sources, and transformations of DOM during four years in a tropical montane forest with the help of stable C isotope ratios (δ13C values). We measured δ13C values of DOM in rainfall (RF), throughfall (TF), stemflow (SF), litter leachate (LL), soil solutions at the 0.15 and 0.30 m depths (SS15, SS30), and streamflow (ST) with TOC-IRMS. The δ13C values of DOM did not vary seasonally. We detected an event with a high δ13C value likely attributable to black carbon from local pasture fires. The mean δ13C values of DOM outside the event decreased in the order, RF (-26.0 ± 1.3‰) > TF (-28.7 ± 0.3‰) > SF (-29.2 ± 0.2‰) > LL (-29.6 ± 0.2‰) because of increasing leaching of C-isotopically light compounds. The higher δ13C values of DOM in SS15 (-27.8 ± 1.0‰), SS30 (-27.6 ± 1.1‰), and ST (-27.9 ± 1.1‰) than in the above-ground solutions suggested that roots and root exudates are major belowground DOM sources. Although in DOM the C/N ratios correlated with the δ13C values when all solutions were considered, this was not the case for SS15, SS30, and ST alone. Thus, the δ13C values of DOM provide an additional tool to assess the sources and turnover of DOM.

Association of Non-Invasive Respiratory Support with Extubation Outcomes in Brain-Injured Patients Receiving Mechanical Ventilation: A Secondary Analysis of ENIO

RATIONALE

Non-invasive respiratory support using high flow nasal cannula (HFNC) or non-invasive positive pressure ventilation (NIPPV) can decrease the risk of reintubation in patients being liberated from mechanical ventilation, but effects in patients with acute brain injury are unknown.

OBJECTIVES

To evaluate the association between post-extubation non-invasive respiratory support and reintubation in patients with acute brain injury being liberated from mechanical ventilation.

METHODS

This was a secondary analysis of a prospective, observational study of mechanically ventilated patients with acute brain injury (NCT03400904). The primary endpoint was reintubation during ICU admission. We used mixed effects logistic regression models with patient-level covariates and random intercepts for hospital and country to evaluate the association between prophylactic (i.e, planned) HFNC or NIPPV and reintubation.

MEASUREMENTS AND MAIN RESULTS

1,115 patients were included from 62 hospitals and 19 countries, of whom 267 received HFNC or NIPPV following extubation (23.9%). Compared to conventional oxygen therapy, neither prophylactic HFNC nor NIPPV was associated with decreased risk of reintubation (respectively, odds ratio (OR), 0.97; 95% confidence interval (CI), 0.54-1.73; OR, 0.63; 95%CI, 0.30-1.32). Findings remained consistent in sensitivity analyses accounting for alternate adjustment procedures, missing data, shorter timeframes of extubation failure, and competing risks precluding reintubation. In a Bayesian analysis using skeptical and data-driven priors, the probability of reduced reintubation ranged from 17-34% for HFNC and 46-74% for NIPPV.

CONCLUSIONS

In a large cohort of brain-injured patients undergoing liberation from mechanical ventilation, prophylactic use of HFNC and NIPPV were not associated with reintubation. Prospective trials are needed to explore treatment effects in this population.

Extubation in neurocritical care patients: the ENIO international prospective study

PURPOSE

Neurocritical care patients receive prolonged invasive mechanical ventilation (IMV), but there is poor specific information in this high-risk population about the liberation strategies of invasive mechanical ventilation.

METHODS

ENIO (NCT03400904) is an international, prospective observational study, in 73 intensive care units (ICUs) in 18 countries from 2018 to 2020. Neurocritical care patients with a Glasgow Coma Score (GCS) ≤ 12, receiving IMV ≥ 24 h, undergoing extubation attempt or tracheostomy were included. The primary endpoint was extubation failure by day 5. An extubation success prediction score was created, with 2/3 of patients randomly allocated to the training cohort and 1/3 to the validation cohort. Secondary endpoints were the duration of IMV and in-ICU mortality.

RESULTS

1512 patients were included. Among the 1193 (78.9%) patients who underwent an extubation attempt, 231 (19.4%) failures were recorded. The score for successful extubation prediction retained 20 variables as independent predictors. The area under the curve (AUC) in the training cohort was 0.79 95% confidence interval (CI₉₅) [0.71-0.87] and 0.71 CI₉₅ [0.61-0.81] in the validation cohort. Patients with extubation failure displayed a longer IMV duration (14 [7-21] vs 6 [3-11] days) and a higher in-ICU mortality rate (8.7% vs 2.4%). Three hundred and nineteen (21.1%) patients underwent tracheostomy without extubation attempt. Patients with direct tracheostomy displayed a longer duration of IMV and higher in-ICU mortality than patients with an extubation attempt (success and failure).

CONCLUSIONS

In neurocritical care patients, extubation failure is high and is associated with unfavourable outcomes. A score could predict extubation success in multiple settings. However, it will be mandatory to validate our findings in another prospective independent cohort.

Impact of preoperative hemodynamic optimization on right ventricular failure after left ventricular assist device implantation

Background

Preoperative hemodynamic parameters are linked to higher rates of right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation. It is unclear if preoperative hemodynamic optimization decreases the incidence of RVF after LVAD.

Methods

Single-center retrospective analysis of consecutive LVAD recipients between 2015 and 2020. Pre-operative right heart catheterization and a strategy of hemodynamic optimization were performed in all patients. Pre-operative right ventricular dysfunction (RVD) was defined by a CVP ≥16 mmHg and pulmonary artery pulsatility index (PAPi) &lt;1.85. The optimization goal was defined as CVP &lt;16 mmHg, PAPi ≥1.85, and Cardiac Index of ≥2.0. The main outcome was RVF (inotropes &gt;14 days, discharge on home inotropes, or right ventricular mechanical support device).

Results

128 LVAD recipients (age 58 years, 74% male, 68% had non-ischemic cardiomyopathy, 45% were on home inotropes, HeartMate 2 in 61%, HeartMate 3 in 31%, and HVAD in 9%) were analyzed. Pre-operative RV dysfunction was present in 48% and these patients were younger, with higher rates of home inotropes, and intra-aortic balloon pump (IABP) pre-LVAD. Postoperative RVF occurred in 60% of patients with RV dysfunction and 40% of the patients without pre-operative RV dysfunction (p&lt;0.002). 40% of patients with RV dysfunction achieved RV optimization goals (32% required IABP). Among those, 53% developed RVF-Post LVAD. RVF was numerically but not significantly higher among those with RV dysfunction who achieved hemodynamic goals (66% vs. 34%, p=0.37) vs. those that did not. Patients with RVF-post LVAD had 10% (n=5) in-hospital mortality.

Conclusion

Pre-LVAD RV dysfunction based on hemodynamic markers is associated with RVF after LVAD implantation. In patients with RV dysfunction, a strategy of pre-LVAD “optimization” to achieve RV hemodynamic optimization goals did not affect the incidence of post-operative RVF.

Funding Acknowledgement

Type of funding sources: None.

Measurement and Analysis of Lobar Lung Deformation After a Change of Patient Position During Video-Assisted Thoracoscopic Surgery

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive surgical technique for the diagnosis and treatment of early-stage lung cancer. During VATS, large lung deformation occurs as a result of a change of patient position and a pneumothorax (lung deflation), which hinders the intraoperative localization of pulmonary nodules. Modeling lung deformation during VATS for surgical navigation is desirable, but the mechanisms causing such deformation are yet not well-understood. In this study, we estimate, quantify and analyze the lung deformation occurring after a change of patient position during VATS. We used deformable image registration to estimate the lung deformation between a preoperative CT (in supine position) and an intraoperative CBCT (in lateral decubitus position) of six VATS clinical cases. We accounted for sliding motion between lobes and against the thoracic wall and obtained consistently low average target registration errors (under 1 mm). We observed large lung displacement (up to 40 mm); considerable sliding motion between lobes and against the thoracic wall (up to 30 mm); and localized volume changes indicating deformation. These findings demonstrate the complexity of the change of patient position phenomenon, which should necessarily be taken into account to model lung deformation for intraoperative guidance during VATS.

Association between inflammation and neural plasticity biomarkers in olfactory neuroepithelium – derived cells and cognitive performance in patients with major depressive disorder

Introduction

Inflammation and neural plasticity play a significant role in major depressive disorder (MDD) pathogenesis and cognitive dysfunction. The olfactory neuroepithelium (ON), closely related to the central nervous system (CNS), allows a non-invasive, low-cost study of neuropsychiatric disorders. However, few studies have used ON cells to ascertain them as biomarkers for MDD.

Objectives

Determine the relationship between inflammatory/neural plasticity markers and cognitive functioning in MDD patients and healthy controls.

Methods

Sample: 9 MDD patients and 7 healthy controls. Exclusion criteria: other Axis I mental disorders (patients) or any mental disorder (controls) and any inflammatory, autoimmune, or CNS diseases. Assessment: sociodemographic, clinical, and cognitive variables (CANTAB) were recorded. mRNA was isolated from ON cells and MAPK14, IL6, TNF-α, Mecp2, BDNF, GSK3, GRIA2, and FosB gene expression levels were quantified using quantitative polymerase chain reaction.

Results

MDD patients showed decreased levels of BDNF (p=0.022), GSK3 (p=0.027), and working memory (p=0.024) compared with healthy controls. In healthy controls, planning was positively correlated with NRF2, BDNF, and MAPK14 gene expression. In MDD patients no correlation between cognitive parameters and inflammation/neural plasticity biomarkers was found.

Conclusions

These results reveal that: (1) Plasticity biomarkers such as BDNF and GSK3 could be useful diagnostic tools for MDD (2) MDD is associated with working memory deficits; (3) no association could be determined between planning and NRF2, BDNF, and MAPK14 gene expression in MDD and (4) the ON is a promising model in the study of neuropsychiatric disorders.

Disclosure

No significant relationships.

Risk for Newly Diagnosed Diabetes >30 Days After SARS-CoV-2 Infection Among Persons Aged <18 Years - United States, March 1, 2020-June 28, 2021

The COVID-19 pandemic has disproportionately affected people with diabetes, who are at increased risk of severe COVID-19.* Increases in the number of type 1 diabetes diagnoses (1,2) and increased frequency and severity of diabetic ketoacidosis (DKA) at the time of diabetes diagnosis (3) have been reported in European pediatric populations during the COVID-19 pandemic. In adults, diabetes might be a long-term consequence of SARS-CoV-2 infection (4-7). To evaluate the risk for any new diabetes diagnosis (type 1, type 2, or other diabetes) >30 days† after acute infection with SARS-CoV-2 (the virus that causes COVID-19), CDC estimated diabetes incidence among patients aged <18 years (patients) with diagnosed COVID-19 from retrospective cohorts constructed using IQVIA health care claims data from March 1, 2020, through February 26, 2021, and compared it with incidence among patients matched by age and sex 1) who did not receive a COVID-19 diagnosis during the pandemic, or 2) who received a prepandemic non-COVID-19 acute respiratory infection (ARI) diagnosis. Analyses were replicated using a second data source (HealthVerity; March 1, 2020-June 28, 2021) that included patients who had any health care encounter possibly related to COVID-19. Among these patients, diabetes incidence was significantly higher among those with COVID-19 than among those 1) without COVID-19 in both databases (IQVIA: hazard ratio [HR] = 2.66, 95% CI = 1.98-3.56; HealthVerity: HR = 1.31, 95% CI = 1.20-1.44) and 2) with non-COVID-19 ARI in the prepandemic period (IQVIA, HR = 2.16, 95% CI = 1.64-2.86). The observed increased risk for diabetes among persons aged <18 years who had COVID-19 highlights the importance of COVID-19 prevention strategies, including vaccination, for all eligible persons in this age group,§ in addition to chronic disease prevention and management. The mechanism of how SARS-CoV-2 might lead to incident diabetes is likely complex and could differ by type 1 and type 2 diabetes. Monitoring for long-term consequences, including signs of new diabetes, following SARS-CoV-2 infection is important in this age group.

Impact of induction therapy on outcomes after heart transplantation

Introduction

Approximately 50% of heart transplant (HT) programs currently employ a strategy of induction therapy (IT) with either interleukin-2 receptor antagonists (IL2RA) or polyclonal anti-thymocyte antibodies (ATG) during the early postoperative period. However, the overall utility of such therapy is uncertain and data comparing induction protocols are limited.

Methods

Adult HT recipients were identified in the United Network for Organ Sharing (UNOS) registry between 1990 and 2020. Patients were grouped according to administration of induction in the post-operative period after HT. Accounting for re-transplantation, Fine and Gray's test compared cumulative incidences of all-cause mortality between groups. Univariate and multivariate analysis were performed using the competing risk model. The risk of treated rejection and hospitalization for infection or rejection was analyzed with multivariable logistic regression.

Results

A total of 63,849 HT recipients were included in the study and among those 59% did not receive induction, 16.6% received ATG, 19.1% IL2RA, 0.7% alemtuzumab, and 4.6% OKT3. Since 2000 IL2RA is the most frequently used form of induction therapy whereas OK3 is not used in the past decade. In multivariable logistic regression models, use of ATG is associated with lower risk of treated rejection at one year after HT (relative risk ratio 0.55, 95% CI 0.47–0.63, p&lt;0.001) compared with no induction whereas IL2RA had similar risk of treated rejection. Similarly, the risk of rejection requiring hospitalization was significantly lower with ATG than no induction. No significant differences in rates of infection requiring hospitalization were noted between groups. Moreover, no differences in rates of post-transplant lymphoproliferative disease and any malignancy were noted between those receiving induction versus no induction. Adjusted all-cause mortality was significantly lower among those treated with ATG than patients that did not receive induction therapy (sub-hazard ratio 0.72, 95% CI 0.63–0.82, p&lt;0.001) (Figure).

Conclusion

Induction therapy with IL2RA is the most used approach. ATG is associated with lower risk of treated rejection and all-cause mortality than no induction and IL2RA.

Funding Acknowledgement

Type of funding sources: None.

Trends, risk factors and mortality of unplanned 30-day readmission after heart transplantation

Introduction

Outcomes after heart transplantation have improved, but the burden of readmissions is understudied. We sought to examine the incidence, risk factors, and associated mortality of unplanned 30-day readmissions following heart transplantation.

Methods

This cohort study examined patient data from the United States population-based Nationwide Readmissions Database. All adults (age ≥18 years) who underwent isolated heart transplantation in US hospitals between January to November of 2012 to 2018 were included. The primary outcomes were 30-day readmission rates and readmission mortality.

Results

A total of 14,784 patients who underwent heart transplantation from 2012 to 2018 were included in our analysis. A total of 3299 (22.3%) patients were readmitted within 30 days after discharge. The median time from discharge to readmission was 9 days, and approximately 70% of the readmissions occurred within 15 days. After multivariable analysis, only CKD (Hazard ratio (HR): 1.11 95% CI 1.00–1.23) and length of stay (HR: 1.002; 95% CI 1.001–1.003; p&lt;0.001) were associated with increased 30-day post-heart transplantation readmission. Readmissions diagnoses were heart transplantation complications, heart transplant rejection, postoperative infection, acute kidney injury, heart failure, pulmonary embolism, pneumonia, and pericardial effusion. The overall incidence of infection as a cause of readmission was 24.9%, with an associated mortality of 2.6% and a Median LOS of 7 days (4–14). The overall incidence of rejection was 38.0%, with a mortality of 1.2% and a median LOS of 5 days (3–8).

Conclusion

Approximately 1 in 5 patients will be readmitted within 30 days after heart transplantation, and most of those readmissions will occur during the first two weeks after discharge. Readmissions were associated with a low mortality rate.

Funding Acknowledgement

Type of funding sources: None.

Outcomes of diabetic patients with end-stage heart failure listed for heart transplantation: a propensity-matched analysis

Background

There are on-going concerns about offering heart transplants to patients with diabetes due to the risk of poor outcomes. We investigated the current trends and outcomes of patients listed for heart transplants in the U.S. and provided a method for risk-stratification.

Methods

Using data from the United Network for Organ Sharing (UNOS), we identified heart failure patients listed for heart transplants between 2010 and 2019. Diabetic patients were propensity-matched with non-diabetes, and waitlist mortality as well as post-transplant graft survival were compared between the two matched groups. Further risk-stratification of the diabetic cohort was done based on the risk factors that independently predict the risk of graft failure.

Results

28,928 adult patients (30% diabetic) with end-stage heart failure were added to the waitlist over the study period. In the propensity-matched cohort, waitlist mortality was higher with diabetics compared to non-diabetics: 19.3 vs 17.1 deaths per 100 person-years, respectively, (HR=1.13 (95% CI=1.04–1.22, p=0.002). Over the study period, 5739 diabetics (mean age 57.6 years, 21.9% female) were transplanted. A total of 1308 (23.3%) and 1143 (20.4%) graft failures occurred in diabetic and non-diabetic recipients, respectively. Compared to non-diabetics, diabetics experienced worse graft survival (HR=1.17, 95% CI=1.08–1.26, p&lt;0.001). We developed a risk score based on the 12 risk factors/markers that independently predict worse graft survival and a risk score of 4 reasonably differentiates between low and high-risk diabetics. Low risk diabetics (score≤4) had similar graft survival as non-diabetics with 1- and 5-year survival of 92.7% and 80.5%, respectively, (HR=0.91, 95% CI=0.82–1.01, p=0.06). On the other hand, high-risk diabetics had worse graft survival compared to non-diabetics (HR=1.52, 95% CI=1.38–1.67, P&lt;0.001) with 1- and 5-year graft survival of 86.8% and 69.8%, respectively.

Conclusion

Diabetic patients with end-stage heart failure listed for heart transplantation experience higher waitlist mortality and worse post-transplant graft survival compared to non-diabetics. However, a simple risk score can be used for further risk-stratification in these patients to maximize survival benefit.

Funding Acknowledgement

Type of funding sources: None.

Trends, risk factors and prognostic implications of postoperative stroke after heart transplantation: an analysis of the UNOS database

Background

Post-operative stroke increases morbidity and mortality after cardiac surgery. Data on characteristics and outcomes of stroke after heart transplantation (HT) are limited.

Methods

We conducted a retrospective analysis of the UNOS database from 2009 to 2020 to identify adults who developed stroke after orthotropic HT. HT recipients were divided according to the presence or absence of postoperative stroke. The primary endpoint was all-cause mortality after HT.

Results

A total of 25,015 HT recipients were analyzed, including 719 (2.9%) patients who suffered perioperative stroke. The rates of stroke increased from 2.1% in 2009 to 3.7% in 2019 and the risk of stroke was higher after the implantation of the new allocation system (odds ratio 1.29, 1.29, 95% Confidence Intervals [CI] 1.06–1.56, p=0.01). HT recipients with postoperative stroke were older (p=0.008), with higher rates of prior cerebrovascular accident (CVA) (p=0.004), prior cardiac surgery (p&lt;0.001), longer waitlist time (p=0.04), higher rates of extracorporeal membrane oxygenation support (ECMO) (p&lt;0.001), left ventricular assist devices (LVAD) (p&lt;0.001), mechanical ventilation (p=0.003) and longer ischemic time (p&lt;0.001). After multivariable adjustment for recipient and donor characteristics, age, prior cardiac surgery, CVA, support with LVAD, ECMO, ischemic time and mechanical ventilation at the time of HT were independent predictors of postoperative stroke. Stroke was associated with increased risk of 30-day and all-cause mortality after HT (hazard ratio [HR] 1.49, CI 1.12–1.99, p=0.007).

Conclusion

Perioperative stroke after HT is infrequent but associated with higher mortality. Redo sternotomy, LVAD and ECMO support at HT are among the risk factors identified.

Funding Acknowledgement

Type of funding sources: None. Risk factors for stroke

Changing demographics, temporal trend in waitlist and post-transplant outcomes after heart transplantation in the United States: analysis of unos database 1991–2019

Background

The landscape of heart transplantation (HT) has changed significantly with respect to patient selection, surgical techniques, and patient outcomes. We sought to investigate temporal trends in patient characteristics, waitlist and post-transplant outcomes after HT in the U.S.

Methods

We queried the national database of the United Network of Organ Sharing (UNOS) to identify adults listed for HT in the U.S. between 1991 and 2019. Patients were divided into four eras based on the three time points in which changes were made to the patient selection/allocation policy (1999, 2006, and 2018), and patient characteristics as well as waitlist and post-transplant outcomes were evaluated for each era.

Results

Between 1991 and 2019, a total of 95,179 patients were added to the waitlist for HT in the U.S. Compared to era 1, patients listed in era 4 were older (mean age: 52.4 years), more female (27.6%) and ethnic minorities (40%), and with higher-risk comorbidities (28.8% diabetes, 35.6% obese). Over the study period, there were 22,070 waitlist deaths and 61,687 transplants.

Compared to the preceding era, there was significant decrease in waitlist mortality in the last 2 eras (e.g., sub-hazard ratio for era 4 vs era 3 =0.37, 95% CI=0.32–0.44). For each year, only 27.1% to 40.5% of those on the waitlist were transplanted. Among those who were transplanted, there was increase in the rates of in-hospital stroke (2.8% in era 1 to 3.7% in era 4), renal failure requiring dialysis (7.2% to 17.1%), and hospital length of stay (14 to 17 days), p-values&lt;0.001 for all. However, this has not negatively impacted short-term survival when compared to the preceding era (1-year graft survival = 89.7% in era 4). Based on a projection model, we predict a 47% increase in living adult heart transplant recipients to to 44,366 in 2040.

Conclusion

There have been significant changes in the characteristics of patients listed for HT in the U.S., including an increasing proportion of high-risk co-morbidities. Although the transplant volume has increased, the wide supply-demand gap persisted. The last 2 changes in the allocation policy in 2006 and 2018 achieved their primary objective of reducing waitlist mortality.

Funding Acknowledgement

Type of funding sources: None.

Short and long term outcomes of cardiac amyloidosis patients listed for heart transplantation in the united states: a propensity-matched analysis

Background

Heart transplantation (HT) in cardiac amyloidosis (CA) patients has been historically controversial due to the risk of amyloid recurrence. However, recent single-center experiences suggest good outcomes in carefully selected patients. We sought to evaluate contemporary outcomes of CA patients listed for HT in the U.S. and evaluate predictors of survival

Methods

Using data from the United Network for Organ Sharing database on adult patients listed for a donor heart in the U.S. between 2010 and 2019, we identified 3 cohorts of patients, namely CA, dilated cardiomyopathy (DCM), and non-CA restrictive cardiomyopathy (RCM). Propensity-match analysis was used to compare primary outcomes of waitlist mortality and post-transplant graft survival between CA and DCM.

Results

Over the study period, 411 CA patients (mean age 62.7 years, 16.1% female) were added to the waitlist. In the propensity-matched cohorts, the rates of waitlist mortality were 33.7, 15.8, and 15.6 per 100 person-years for CA, DCM, and non-CA RCM, respectively. Compared to DCM, there was significantly higher waitlist mortality for CA (HR=1.75, 95% CI=1.16–2.65). Over the study period, 330 CA patients were transplanted with donor hearts. The 1-year graft survival rates for CA, DCM, and non-CA RCM were 89%, 92%, and 86%, respectively; and 5-year graft survival rates were 78%, 82%, and 76%, respectively. Graft survival for CA was significantly worse than DCM (HR=1.46, 1.03–2.08), and the two most significant risk factors for poor graft survival among CA patients were renal failure requiring dialysis while on the waitlist (HR=5.4, 1.6–17) and prior history of malignancy (HR=1.7, 1.0–29). CA patients with neither of the risk factor had 1- and 5-year graft survival that is comparable to those of DCM (HR=1.18, 0.81–1.74). On the other hand, CA patients with either of the risk factor had 1- and 5-year graft survival of 81% and 65%, respectively, (HR=2.33, 1.40–3.87, compared to DCM).

Conclusion

CA patients experience higher waitlist mortality and worse post-transplant graft survival compared to DCM. However, we identified two risk factors that can be used for further risk-stratification in these patients to achieve comparable graft survival as DCM.

Funding Acknowledgement

Type of funding sources: None.

Soil erosion modelling: A global review and statistical analysis

To gain a better understanding of the global application of soil erosion prediction models, we comprehensively reviewed relevant peer-reviewed research literature on soil-erosion modelling published between 1994 and 2017. We aimed to identify (i) the processes and models most frequently addressed in the literature, (ii) the regions within which models are primarily applied, (iii) the regions which remain unaddressed and why, and (iv) how frequently studies are conducted to validate/evaluate model outcomes relative to measured data. To perform this task, we combined the collective knowledge of 67 soil-erosion scientists from 25 countries. The resulting database, named 'Global Applications of Soil Erosion Modelling Tracker (GASEMT)', includes 3030 individual modelling records from 126 countries, encompassing all continents (except Antarctica). Out of the 8471 articles identified as potentially relevant, we reviewed 1697 appropriate articles and systematically evaluated and transferred 42 relevant attributes into the database. This GASEMT database provides comprehensive insights into the state-of-the-art of soil- erosion models and model applications worldwide. This database intends to support the upcoming country-based United Nations global soil-erosion assessment in addition to helping to inform soil erosion research priorities by building a foundation for future targeted, in-depth analyses. GASEMT is an open-source database available to the entire user-community to develop research, rectify errors, and make future expansions.

Soil erosion modelling: A bibliometric analysis

Soil erosion can present a major threat to agriculture due to loss of soil, nutrients, and organic carbon. Therefore, soil erosion modelling is one of the steps used to plan suitable soil protection measures and detect erosion hotspots. A bibliometric analysis of this topic can reveal research patterns and soil erosion modelling characteristics that can help identify steps needed to enhance the research conducted in this field. Therefore, a detailed bibliometric analysis, including investigation of collaboration networks and citation patterns, should be conducted. The updated version of the Global Applications of Soil Erosion Modelling Tracker (GASEMT) database contains information about citation characteristics and publication type. Here, we investigated the impact of the number of authors, the publication type and the selected journal on the number of citations. Generalized boosted regression tree (BRT) modelling was used to evaluate the most relevant variables related to soil erosion modelling. Additionally, bibliometric networks were analysed and visualized. This study revealed that the selection of the soil erosion model has the largest impact on the number of publication citations, followed by the modelling scale and the publication's CiteScore. Some of the other GASEMT database attributes such as model calibration and validation have negligible influence on the number of citations according to the BRT model. Although it is true that studies that conduct calibration, on average, received around 30% more citations, than studies where calibration was not performed. Moreover, the bibliographic coupling and citation networks show a clear continental pattern, although the co-authorship network does not show the same characteristics. Therefore, soil erosion modellers should conduct even more comprehensive review of past studies and focus not just on the research conducted in the same country or continent. Moreover, when evaluating soil erosion models, an additional focus should be given to field measurements, model calibration, performance assessment and uncertainty of modelling results. The results of this study indicate that these GASEMT database attributes had smaller impact on the number of citations, according to the BRT model, than anticipated, which could suggest that these attributes should be given additional attention by the soil erosion modelling community. This study provides a kind of bibliographic benchmark for soil erosion modelling research papers as modellers can estimate the influence of their paper.

Impact of tricuspid regurgitation severity and repair on aortic valve replacement

BACKGROUND

Aortic stenosis is one of the most prevalent valve diseases but is rarely accompanied by tricuspid regurgitation. Our objective was to analyse the impact of tricuspid regurgitation severity and its surgical treatment on prognosis of patients undergoing aortic valve replacement.

METHODS

Retrospective cohort study including all patients presenting with aortic stenosis with some degree of tricuspid regurgitation between 2001 and 2018. Patients were divided into groups according to the degree of tricuspid regurgitation.

RESULTS

From a sample of 8,080 patients with aortic stenosis, 143 (1,8%) presented with more than trace tricuspid regurgitation. Among patients with mild, moderate, or severe tricuspid regurgitation, we observed no differences in 30-day (15,1 vs 14,8 vs 8,7%;p=0,727), 12-month (51,2 vs 56 vs 55%;p=0,892) or 5-year (64 vs 73,3 vs 66,7%;p=0,798) survival. Aortic valve replacement plus tricuspid annuloplasty, when compared with aortic valve replacement only was associated with longer ICU stay (9 vs 3 days;p=0,043) but not higher 30-day (0 vs 15,5%;p=0,112), 12-month (38,5 vs 54,3%;p=0,278) or 5-year mortality (57,1 vs 67.1%;p=0,594). Only history of liver disease and postoperative major morbidity were independent predictors of survival 30 days, 12 months and 5 years after surgery.

CONCLUSIONS

Severity of tricuspid regurgitation in patients with aortic stenosis was not associated with increased mortality. Tricuspid annuloplasty did not improve survival in this subset of patients but was associated with increased postoperative morbidity.

Completed suicide in bipolar i patients after their first hospitalisation

Introduction

Bipolar disorder is a mental disorder that has one of the greatest risk of completed suicide (CS)

Objectives

Determine the rate and the risk factors of CS in a cohort of Bipolar I patients followed after their first hospitalization

Methods

We choose all Bipolar I patients (DSM-IV) who were first time hospitalized in our Psychiatric unit between 1996 and 2016. We reviewed the charts of first hospitalization and recorded multiple baseline variables. In the follow-up we updated the database recording all patients who CS. We compared the different baseline variables between Bipolar patients who CS and the rest.

Results

Of a total of 254 bipolar I patients 9 (3,5%) CS in the mean of 13 years of follow up (rate 40 times higher than General Population). The average age at CS was 41.1 years (range between 26 and 71 years old) so there was a 9 years gap on average between the first psychiatric hospitalization and suicide. CS was characterized by a violent act (8 out of 9 cases, 89 %). When we compared BP patients who CS with the rest, only history of suicide in first-degree relatives was detected as a risk factor significantly associated (P<0.01) with CS. Conversely baseline treatment with anticonvulsants (mainly valproate) was detected as a significantly (P<0.004) protective factor of CS.

Conclusions

1-Bipolar I patients after first hospitalization completed suicide 40 times higher than general population almost always by violent method 2-History of CS in first-degree relatives is predictor of completed suicide

Disclosure

No significant relationships.

Completed suicide in bipolar ii patients after their first hospitalization

Introduction

Bipolar disorder, especially Bipolar II subtype, is a mental disorder that has one of the greatest risk of completed suicide (CS).

Objectives

Determine the rate and the risk factors of CS in a cohort of Bipolar II patients followed after their first hospitalization

Methods

We choose all Bipolar II patients (DSM-IV) who were hospitalized for first time in our Psychiatric unit between 1996 and 2016. We reviewed the charts of first hospitalization and recorded multiple baseline variables. In the follow-up we updated the database recording all patients who CS. We compared the different baseline variables between Bipolar II patients who CS and the rest

Results

Of a total of 59 bipolar II patients 6 (10 %) CS in the mean of 13 years of follow up (rate 120 times higher than General Population). The average age at CS was 45.3 years (range between 33 and 57 years old) so there was a 2 years gap on average between the first psychiatric hospitalization and suicide. CS was characterized by a violent act (5 out of 6 cases, 83 %). When we compared BP II patients who CS with the rest, only history of previous violent suicide attempt was detected as a risk factor significantly associated (P<0.04) with CS.

Conclusions

Bipolar II patients CS early after their first hospitalization and at very high rate (120 times than GP) almost always by violent method. History of previous violent suicide attempt is predictor of completed suicide

Disclosure

No significant relationships.

A hybrid, image-based and biomechanics-based registration approach to markerless intraoperative nodule localization during video-assisted thoracoscopic surgery

The resection of small, low-dense or deep lung nodules during video-assisted thoracoscopic surgery (VATS) is surgically challenging. Nodule localization methods in clinical practice typically rely on the preoperative placement of markers, which may lead to clinical complications. We propose a markerless lung nodule localization framework for VATS based on a hybrid method combining intraoperative cone-beam CT (CBCT) imaging, free-form deformation image registration, and a poroelastic lung model with allowance for air evacuation. The difficult problem of estimating intraoperative lung deformations is decomposed into two more tractable sub-problems: (i) estimating the deformation due the change of patient pose from preoperative CT (supine) to intraoperative CBCT (lateral decubitus); and (ii) estimating the pneumothorax deformation, i.e. a collapse of the lung within the thoracic cage. We were able to demonstrate the feasibility of our localization framework with a retrospective validation study on 5 VATS clinical cases. Average initial errors in the range of 22 to 38 mm were reduced to the range of 4 to 14 mm, corresponding to an error correction in the range of 63 to 85%. To our knowledge, this is the first markerless lung deformation compensation method dedicated to VATS and validated on actual clinical data.

Total organic carbon concentrations in ecosystem solutions of a remote tropical montane forest respond to global environmental change

The response of organic carbon (C) concentrations in ecosystem solutions to environmental change affects the release of dissolved organic matter (DOM) from forests to surface and groundwaters. We determined the total organic C (TOC) concentrations (filtered <1-7 µm) and the ratios of TOC/dissolved organic nitrogen (DON) concentrations, electrical conductivity (EC), and pH in all major ecosystem solutions of a tropical montane forest from 1998 to 2013. The forest was located on the rim of the Amazon basin in Ecuador and experienced increasing numbers of days with >25°C, decreasing soil moisture, and rising nitrogen (N) deposition from the atmosphere during the study period. In rainfall, throughfall, mineral soil solutions (at the 0.15- and 0.30-m depths), and streamflow, TOC concentrations and fluxes decreased significantly from 1998 to 2013, while they increased in stemflow. TOC/DON ratios decreased significantly in rainfall, throughfall, soil solution at the 0.15-m depth, and streamflow. Based on Δ¹⁴ C values, the TOC in rainfall and mineral soil solutions was 1 year old and that of litter leachate was 10 years old. The pH in litter leachate decreased with time, that in mineral soil solutions increased, while those in the other ecosystem solutions did not change. Thus, reduced TOC solubility because of lower pH values cannot explain the negative trends in TOC concentrations in most ecosystem solutions. The increasing TOC concentrations and EC in stemflow pointed at an increased leaching of TOC and other ions from the bark. Our results suggest an accelerated degradation of DOM, particularly of young DOM, associated with the production of N-rich compounds simultaneously to changing climatic conditions and increasing N availability. Thus, environmental change increased the CO₂ release to the atmosphere but reduced DOM export to surface and groundwater.

Extubation strategies in neuro-intensive care unit patients and associations with outcomes: the ENIO multicentre international observational study

Background

Prolonged invasive ventilation is common in patients with severe brain injury. Information on optimal management of extubation and on the use of tracheostomy in these patients is scarce. International guidelines regarding the ventilator liberation and tracheostomy are currently lacking.

Methods

The aim of ‘Extubation strategies in Neuro-Intensive care unit patients and associations with Outcomes’ (ENIO) study is to describe current management of weaning from invasive ventilation, focusing on decisions on timing of tracheal extubation and tracheostomy in intensive care unit (ICU) patients with brain injury. We conducted a prospective, international, multi-centre observational study enrolling patients with various types of brain injury, including trauma, stroke, and subarachnoid haemorrhage, with an initial Glasgow Coma Score equal or less than 12, and a duration of invasive ventilation longer than 24 hours from ICU admission. ENIO is expected to include at least 1,500 patients worldwide. The primary endpoint of the ENIO study is extubation success in the 48 hours following endotracheal tube removal. The primary objective is to validate a score predictive of extubation success. To accomplish this, the study population will be randomly divided to a development cohort (2/3 of the included patients) and a validation cohort (the remaining 1/3). Secondary objectives are: to determine the incidence of extubation success rate according to various time-frames (within 96 hours, >96 hours after extubation); to validate (existing) prediction scores for successful extubation according to various time-frames and definitions (i.e., tracheostomy as extubation failure); and to describe the current practices of extubation and tracheostomy, and their associations.

Discussion

ENIO will be the largest prospective observational study of ventilator liberation and tracheostomy practices in patients with severe brain injury undergoing invasive mechanical ventilation, providing a validated predictive score of successful extubation.

Trial registration

The ENIO study is registered in the Clinical Trials database: NCT 03400904.

MRIgRT head and neck anthropomorphic QA phantom: Design, development, reproducibility, and feasibility study

PURPOSE

The purpose of this paper was to design, manufacture, and evaluate a tissue equivalent, dual magnetic resonance/computed tomography (MR/CT) visible anthropomorphic head and neck (H&N) phantom. This phantom was specially designed as an end-to-end quality assurance (QA) tool for MR imaging guided radiotherapy (MRIgRT) systems participating in NCI-sponsored clinical trials.

METHOD

The MRIgRT H&N phantom was constructed using a water-fillable acrylic shell and a custom insert that mimics an organ at risk (OAR) and target structures. The insert consists of a primary and secondary planning target volume (PTV) manufactured of a synthetic Clear Ballistic gel, an acrylic OAR and surrounding tissue fabricated using melted Superflab. Radiochromic EBT3 film and thermoluminescent detectors (TLDs) were used to measure the dose distribution and absolute dose, respectively. The phantom was evaluated by conducting an end-to-end test that included: imaging on a GE Lightspeed CT simulator, planning on Monaco treatment planning software (TPS), verifying treatment setup with MR, and irradiating on Elekta's 1.5 T Unity MR linac system. The phantom was irradiated three times using the same plan to determine reproducibility. Three institutions, equipped with either ViewRay MRIdian 60 Co or ViewRay MRIdian Linac, were used to conduct a feasibility study by performing independent end-to-end studies. Thermoluminescent detectors were evaluated in both reproducibility and feasibility studies by comparing ratios of measured TLD to reported TPS calculated values. Radiochromic film was used to compare measured planar dose distributions to expected TPS distributions. Film was evaluated by using an in-house gamma analysis software to measure the discrepancies between film and TPS.

RESULTS

The MRIgRT H&N phantom on the Unity system resulted in reproducible TLD doses (SD < 1.5%). The measured TLD to calculated dose ratios for the Unity system ranged from 0.94 to 0.98. The Viewray dose result comparisons had a larger range (0.95-1.03) but these depended on the TPS dose calculations from each site. Using a 7%/4 mm gamma analysis, Viewray institutions had average axial and sagittal passing rates of 97.3% and 96.2% and the Unity system had average passing rates of 97.8% and 89.7%, respectively. All of the results were within the Imaging and Radiation Oncology Core in Houston (IROC-Houston) standard credentialing criteria of 7% on TLDs, and >85% of pixels passing gamma analysis using 7%/4 mm on films.

CONCLUSIONS

An MRIgRT H&N phantom that is tissue equivalent and visible on both CT and MR was developed. The results from initial reproducibility and feasibility testing of the MRIgRT H&N phantom using the tested MGIgRT systems suggests the phantom's potential utility as a credentialing tool for NCI-clinical trials.

Engaged Environmental Science for Underserved Youth

The National Institute for Environmental Health Sciences has called for targeted efforts to engage underserved youth in environmental education programs that support environmental literacy and contribute to the development of a diverse workforce pipeline for environmental science-related occupations. Evidence suggests that career knowledge among low income and minority youth is more likely to be incompatible with post-secondary educational opportunities than other racial and ethnic groups. One approach to attenuating discordant college and career expectations among underserved youth is building networks for information sharing between secondary and post-secondary students. The purpose of this commentary is to describe the development and implementation of a high school curriculum on environmental science and environmental justice by Texas A&M University in collaboration with community engagement partners, students, and teachers at Furr High School, an innovative XQ Super School in Houston, Texas.

Acute kidney injury after cardiac surgery: prevalence, impact and management challenges

Acute kidney injury (AKI) is a major medical problem that is of particular concern after cardiac surgery. Perioperative AKI is independently associated with an increase in short-term morbidity, costs of treatment, and long-term mortality. In this review, we explore the definition of cardiac surgery-associated acute kidney injury (CSA-AKI) and identify diverse mechanisms and risk factors contributing to the renal insult. Current theories of the pathophysiology of CSA-AKI and description of its clinical course will be addressed in this review. Data on the most promising renal protective strategies in cardiac surgery, from well-designed studies, will be scrutinized. Furthermore, diagnostic tools such as novel biomarkers of AKI and their potential utility will be discussed.

Surgery for acute infective endocarditis: epidemiological data from a Spanish nationwide hospital-based registry

OBJECTIVES

Infective endocarditis (IE) is a serious and eventually lethal disease with rising incidence in the past couple of decades. The aim of this study was to evaluate the contemporary epidemiological trends of surgical endocarditis patients, to analyse the clinical outcomes and to study their profile, associated prognostic factors and costs.

METHODS

This is a retrospective study of all patients admitted for IE in Spanish hospitals and discharged between 1 January 1997 and 31 December 2014. Data were extracted from the minimum basic data set of the National Surveillance System for Hospital Data in Spain provided by the Spanish Ministry of Health. Hospitalizations, comorbidities, outcomes and costs were analysed.

RESULTS

In total, 34 399 patients with IE were included; 15.7% of patients received surgical treatment and 84.3% received medical treatment only. Surgical patients were mostly men (71.9%) and had a lower mean age (59.2 ± 16.08 years) than the medical treatment group (P < 0.0001). Mortality among surgical patients showed a decreasing trend between 1997 (32.0%) and 2014 (22.7%) and increased with age (47.6% in ≥85 years of age). Length of hospital stay and the percentage of patients with organ dysfunction were also higher in this group. The cost of the surgical treatment group was higher and increased since 1997 (15 259.22 euros), remaining stable from 2010 (40 700 euros) (P < 0.0001).

CONCLUSIONS

Surgical treatment in IE has trended upwards in Spain during the last 2 decades. Patients are getting older and more frequently experience organ dysfunction. Mortality ratio steadily declined without changes in the length of hospital stay.

Stationary Wavelet-Fourier Entropy and Kernel Extreme Learning for Bearing Multi-Fault Diagnosis

Bearing fault diagnosis methods play an important role in rotating machine health monitoring. In recent years, various intelligent fault diagnosis methods have been proposed, which are mainly based on the features extraction method combined with either shallow or deep learning methods. During the last few years, Shannon entropy features have been widely used in machine health monitoring, improving the accuracy of the bearing fault diagnosis process. Therefore, in this paper, we consider the combination of multi-scale stationary wavelet packet analysis with the Fourier amplitude spectrum to obtain a new discriminative Shannon entropy feature that we call stationary wavelet packet Fourier entropy (SWPFE). Features extracted by our SWPFE method are then passed onto a shallow kernel extreme learning machine (KELM) classifier to diagnose bearing failure types with different severities. The proposed method was applied on two experimental vibration signal databases of a rolling element bearing and compared to two recently proposed methods called stationary wavelet packet permutation entropy (SWPPE) and stationary wavelet packet dispersion entropy (SWPPE). Based on our results, we can say that the proposed method is able to achieve better accuracy levels than both the SWPPE and SWPDE methods using fewer failure features. Further, as our method does not require any hyperparameter calibration step, it is less dependent on user experience/expertise.

An updated review of adipose derived-mesenchymal stem cells and their applications in musculoskeletal disorders

INTRODUCTION

Adipose-derived mesenchymal stem cells (ASCs) represent a new therapeutic strategy in biomedicine with many potential applications, especially in musculoskeletal disorders. Preclinical and clinical studies based on the administration of ASCs support their efficacy in bone regeneration, joint repair, tendon injury and skeletal muscle alterations. Many of these novel treatments may improve patients' quality of life and prognosis. However, several concerns about the use of stem cells remain unsolved, particularly regarding their safety and side effects. The present work aims to review the nature, clinical trials and patents involving the use of ASCs in musculoskeletal disorders.

AREAS COVERED

In this article, we describe ASCs' isolation, culture and differentiation in vivo and in vitro, advances on ASCs' applications in bone, cartilage, muscle and tendon repair, and patents involving the use of ASCs.

EXPERT OPINION

The use of ASCs in musculoskeletal disorders presents significant therapeutic advantages, including limited autoimmune response, potential cell expansion ex vivo, high plasticity to differentiate into several mesodermal cell lineages, and additional effects of therapeutic interest such as secretion of neurotrophic factors and anti-inflammatory properties. For these reasons, ASCs are promising therapeutic agents for clinical applications in musculoskeletal disorders.

Multi-faceted Characterization of Wet-milled Griseofulvin Nanosuspensions for Elucidation of Aggregation State and Stabilization Mechanisms

Characterization of wet-milled drug suspensions containing neutral polymer-anionic surfactant as stabilizers poses unique challenges in terms of assessing the aggregation state and examining the stabilization mechanisms. Using a multi-faceted characterization method, this study aims to assess the aggregation state of wet-milled griseofulvin (GF) nanosuspensions and elucidate the stabilization mechanisms and impact of stabilizers. Two grades, SSL and L, of hydroxypropyl cellulose (HPC) with molecular weights of 40 and 140 kg/mol, respectively, were used as a neutral stabilizer at concentrations varying from 0 to 7.5% (w/w) without and with 0.05% (w/w) sodium dodecyl sulfate (SDS). The aggregation state was examined via laser diffraction, scanning electron microscope (SEM) imaging, and rheometry. Zeta potential, stabilizer adsorption, surface tension, and drug wettability were used to elucidate the stabilization mechanisms. The results suggest that deviation from a uni-modal PSD and pronounced pseudoplasticity with power-law index lower than one signify severe aggregation. Polymer or surfactant alone was not able to prevent GF nanoparticle aggregation, whereas HPC-SDS combination led to synergistic stabilization. The effect of polymer concentration was explained mainly by the stabilizer adsorption and partly by surface tension. The synergistic stabilization afforded by HPC-SDS, traditionally explained by electrosteric mechanism, was attributed to steric stabilization provided by HPC and enhanced GF wettability/reduced surface tension provided by SDS. Zeta potential results could not explain the mitigation of aggregation by HPC-SDS. Overall, this study has demonstrated that the elucidation of the complex effects of HPC-SDS on GF nanosuspension stability entails a multi-faceted and comprehensive characterization approach.