APSIM-based modeling approach to understand sorghum production environments in Mali

Sorghum production system in the semi-arid region of Africa is characterized by low yields which are generally attributed to high rainfall variability, poor soil fertility, and biotic factors. Production constraints must be well understood and quantified to design effective sorghum-system improvements. This study uses the state-of-the-art in silico methods and focuses on characterizing the sorghum production regions in Mali for drought occurrence and its effects on sorghum productivity. For this purpose, we adapted the APSIM-sorghum module to reproduce two cultivated photoperiod-sensitive sorghum types across a latitude of major sorghum production regions in Western Africa. We used the simulation outputs to characterize drought stress scenarios. We identified three main drought scenarios: (i) no-stress; (ii) early pre-flowering drought stress; and (iii) drought stress onset around flowering. The frequency of drought stress scenarios experienced by the two sorghum types across rainfall zones and soil types differed. As expected, the early pre-flowering and flowering drought stress occurred more frequently in isohyets < 600 mm, for the photoperiod-sensitive, late-flowering sorghum type. In isohyets above 600 mm, the frequency of drought stress was very low for both cultivars. We quantified the consequences of these drought scenarios on grain and biomass productivity. The yields of the highly-photoperiod-sensitive sorghum type were quite stable across the higher rainfall zones > 600 mm, but was affected by the drought stress in the lower rainfall zones < 600 mm. Comparatively, the less photoperiod-sensitive cultivar had notable yield gain in the driest regions < 600 mm. The results suggest that, at least for the tested crop types, drought stress might not be the major constraint to sorghum production in isohyets > 600 mm. The findings from this study provide the entry point for further quantitative testing of the Genotype × Environment × Management options required to optimize sorghum production in Mali.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13593-023-00909-5.

A short, animated storytelling video about sodium intake as a major cardiovascular risk factor and recommendations for a healthy diet: an online, randomized, controlled trial

BACKGROUND

Increased uptake of sodium is a major cause for cardiovascular disease and mortality. Reduction of daily salt intake below a reference level of 2 g per day (the equivalent to 5 g salt/day) is known to effectively reduce cardiovascular mortality. The widespread use of social media, with a constant increase in video consumption, is opening new avenues for the dissemination of innovative and scalable approaches to health-related information and recommendations for a healthy diet, such as via video interventions with short animated stories (SAS).

OBJECTIVE

This study will evaluate the effect of a sodium intake-SAS video intervention on immediate and medium-term knowledge about dietary sodium. Beyond that, immediate and medium-term effects on behavioral expectation to reduce sodium intake as well as voluntary post-trial engagement with the video content will be examined.

METHODS

In this 4-armed, parallel, randomized controlled trial, 10,000 adult, US participants will be randomly assigned to (1) a short, animated storytelling intervention video on sodium as a cardiovascular disease risk factor followed by surveys assessing the facts on sodium and cardiovascular disease conveyed in the video (2) the surveys only, (3) an attention placebo control video followed by the before mentioned surveys, and (4) an arm that is exposed to neither the video nor the surveys. Two weeks later, participants in all four arms will complete all of the surveys.

RESULTS

Primary outcomes are the immediate and medium-term effects of the short, animated storytelling intervention video on knowledge about dietary sodium. Secondary outcomes are immediate and medium-term effects of the short, animated storytelling intervention on behavioral expectation to reduce sodium intake as well as voluntary post-trial engagement with the video content.

CONCLUSION

This study will extend the knowledge on the effects of short, animated storytelling for the containment of the global cardiovascular disease burden. Knowledge on the groups that may be more likely to voluntarily engage with SAS video content will help to improve targeting of future interventions towards audiences at risk. TRIAL REGISTRATION {2A}: ClinicalTrials.gov NCT05735457. Registered on February 21, 2023.

Psychiatric presentations and admissions during the first wave of Covid-19 compared to 2019 in a psychiatric emergency department in Berlin, Germany: a retrospective chart review

BACKGROUND

Most studies agree that the Covid-19 pandemic and the subsequent lockdown had a negative impact on mental health. On the other hand, international studies have shown that psychiatric emergency departments (pED) experienced a decrease in presentations and admissions.

METHODS

Retrospective chart review of all pED presentations and admissions during the first wave of Covid-19 pandemic in Germany (Covid-19 period: 3/2/20 to 05/24/20) in a psychiatric hospital in Berlin compared to 1 year earlier (pre-Covid-19 period). Descriptive statistics and logistic regression were performed.

RESULTS

We observed no statistical significant changes in overall pED presentations and overall hospital admissions during the Covid-19 period compared to the pre-Covid-19 period (813 vs. 894, - 9.1%, p = 0.064 and (363 vs. 437, - 16.9%, p = 0.080 respectively). In the subgroup analysis, less patients with depressive disorders (p = 0.035) and with personality disorders (p = 0.002) presented to the pED, a larger number of presentations with schizophrenia was observed (p = 0.020). In the Covid-19 period, less patients with substance use disorder and paranoid schizophrenia were admitted to the hospital via the pED than in the pre-Covid-19 period (p = 0.035 and p = 0.006, respectively). Bed capacity was reduced in the Covid-19 period by - 32.8% (p <  0.001). Presentations in police custody were 13.7% (p = 0.029) higher during the Covid-19 compared to pre-Covid-19 period, with higher rates in female presentations (p = 0.008) and suicide attempts (p = 0.012) and less hospital admissions (p = 0.048). Logistic regression analyses revealed that positive predictors for pED presentation during Covid-19 period were police custody (p <  0.001), being redirected from another hospital (p <  0.001), suicide attempt (p = 0.038), suicidal thoughts (p = 0.004), presentation with paranoid schizophrenia (p = 0.001) and bipolar and manic disorders (p = 0.004), negative predictors were hospital admission (p <  0.001), depressive disorders (p = 0.021) and personality disorders (p <  0.001).

CONCLUSIONS

A larger number of presentations in police custody during the Covid-19 period may represent untreated medical needs. This was seen predominantly in female patients, suggesting this subgroup might have suffered particularly under lockdown measures. Patients with paranoid schizophrenia were the only subgroup, which increased in absolute numbers, also suggesting a particular lockdown effect. Reduced bed capacity due to infection curbing measures is suggestive to have played an important role in augmenting the threshold for hospital admissions.

Drug-induced enterocolitis syndrome: A rare, severe, non-IgE-mediated immediate drug allergy. Case report and literature review

We report the case of a 4-year-old child who presented with vomiting, abdominal pain, and intense pallor 2 h after amoxicillin ingestion. An IgE-mediated reaction was suspected at first, which was finally diagnosed as a drug-induced enterocolitis syndrome. In this rare and poorly described non-IgE-mediated drug allergy, adrenaline is not effective. This diagnostic challenge must be known in order to administer adequate treatment, i.e., antiemetic drugs (ondansetron) and fluid challenge.

The 2022 monkeypox outbreak: A UK military perspective

With the emergence of SARS-CoV-2 and now monkeypox, the UK Defence Medical Services have been required to provide rapid advice in the management of patients with airborne high consequence infectious diseases (A-HCID). The Defence Public Health Network (DPHN) cadre, consisting of closely aligned uniformed and civilian public health specialists have worked at pace to provide evidence-based recommendations on the clinical management, public health response and policy for monkeypox, with military medicine and pathology clinicians (primarily infectious disease physicians and medical microbiologists). Military environments can be complicated and nuanced requiring specialist input and advice to non-specialists as well as unit commanders both in the UK and overseas. DPHN and military infection clinicians have close links with the UK National Health Service (NHS) and the UK Health Security Agency (UKHSA), allowing for a dynamic two-way relationship that encompasses patient management, public health response, research and development of both UK military and national guidelines. This is further demonstrated with the Royal Air Force (RAF) Air Transport Isolator (ATI) capability, provided by Defence to support the UK Government and UKHSA. Military infectious disease clinicians are also embedded within NHS A-HCID units. In this manuscript we provide examples of the close interdisciplinary working of the DPHN and Defence clinicians in managing military monkeypox patients, co-ordinating the public health response, advising the Command and developing monkeypox policy for Defence through cross-government partnership. We also highlight the co-operation between civilian and military medical authorities in managing the current outbreak.

Lack of PI 3-kinase isoform p110alpha impairs SMC differentiation and proliferation and promotes aortic aneurysm formation

Background

Proliferation and phenotypic modulation of vascular smooth muscle cells (SMCs) significantly contribute to the functionality of the aortic wall. Dysregulation of underlying signal transduction pathways impairs the vessel wall structure and promote the development and progression of abdominal aortic aneurysms (AAA). The PI 3-kinase (PI3K) isoform p110α is activated downstream of receptor tyrosine kinases (RTKs) and represents the most relevant PI3K isoform in SMCs.

Aim

This project follows the hypothesis that p110α deficiency impairs proliferation and phenotypic modulation of SMCs as well as the structure of the extracellular matrix (ECM) and therefore promotes the development and progression of AAA. It was investigated how p110α deficiency affects the plasticity of SMCs, the production and structure of ECM components, and the formation of AAA.

Methods and results

Western blot analyses showed that SMCs isolated from smooth muscle specific p110α−/− (sm-p110α−/−) mice were characterized by decreased expression of the differentiation markers sm-α-actin, calponin and sm-MHC. Mechanistically, phosphorylation of key modulators of the SMC phenotype – AKT1, AKT2, FOXO1, -3 and -4 as well as GSK3β – was impaired in p110α−/− SMCs after RTK stimulation. These findings indicate that phenotypic modulation of p110α−/− SMCs is restricted. In addition, protein expression of elastin and fibrillin was reduced in p110α−/− SMCs. In silico analysis (MatLab macro CT-FIRE and Curvalign) of the ECM produced by SMCs in vitro revealed a significantly reduced elastin fiber length and width in p110α−/− SMCs compared to fibers produced by WT SMCs (p&lt;0.05). Consistently, aortas from sm-p110α−/− mice showed a significantly higher number of elastic fiber breaks specifically in the thoracic section than WT controls (289±31 mmm–2 versus 190±9 mmm–2, n=5, p=0.015). Aortic aneurysms in sm-p110α−/− mice and wild-type littermates were analyzed using the established porcine pancreatic elastase (PPE) model. PPE was perfused into the infrarenal aorta to induce AAA formation. Ultrasound examination of the aorta revealed an enlarged aortic diameter in all PPE-treated mice. However, the increase in aortic diameter in sm-p110α−/− mice (70.16±10.82% mm, n=9) was significant more pronounced compared to wild-type animals (42.44±5.99%, n=10) (p&lt;0.05). Three days after PPE perfusion, the number of elastic fiber breaks was significantly increased, and amount of proliferating SMCs were decreased in the infrarenal aorta of sm-p110α−/− mice compared to WT controls.

Conclusion

p110α deficiency in SMCs impairs aortic wall structure and promotes the development and progression of aortic aneurysms. Mechanistically, p110α activity maintains a differentiated SMC phenotype as well as the expression and assembly of ECM components. These data identify p110α signaling as a modifiable target for preventive and therapeutic strategies for aortic aneurysms.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft

Optimal protamine-to-heparin dosing ratio for the prevention of bleeding complications in patients undergoing TAVR – a multicentre experience

Background

Despite major advances, transcatheter aortic valve replacement (TAVR) is associated with procedure-related vascular and bleeding complications, that have a significant impact on mortality. A recently published study has shown that heparin antagonization using protamine resulted in significantly lower rates of serious bleeding events in patients undergoing TAVR as compared to those without heparin reversal. However, the optimal protamine-to-heparin dosing ratio to prevent bleeding complications without increasing ischemic complications in patients undergoing TAVR is unknown. Accordingly, daily clinical practice varies between selective to routine administration of protamine in different dosing ratios.

Purpose

The aim of this observational multicentre study was to compare the safety and efficacy of two different protamine-to-heparin dosing ratios for the prevention of bleeding complications after TAVR.

Methods

The study included 1446 patients undergoing TAVR, of whom 623 (43.1%) received partial and 823 (56.9%) full heparin antagonization (0.4–0.6 mg versus 0.9–1.0 mg protamine/100 units of heparin). The indication for partial or full heparin antagonization was left to the discretion of the operator, who made the decision according to the patient's individual thrombotic and bleeding risk. The primary endpoint was a composite of 30-day mortality, life-threatening and major bleeding. Safety endpoints included stroke and myocardial infarction at 30 days.

Results

The overall study population had a mean age of 81.1±6.0 years; 47.9% were of female gender.

The baseline characteristics were well balanced between the two groups. Full antagonization of heparin resulted in significantly lower rates of the primary endpoint as compared to partial heparin reversal (5.6 vs. 10.4%, p&lt;0.01), mainly driven by lower rates of life-threatening (0.5 vs 1.6%, p=0.05) and major bleeding (3.2 vs 7.5%, p&lt;0.01). The incidence of major vascular complications was significantly lower in patients with full heparin reversal (3.5 vs 7.5%, p&lt;0.01), as presented in Figure 1. Accordingly, the post-interventional drop in hemoglobin level and the need for red-blood-cell transfusion was lower in patients receiving full as compared to partial heparin reversal (1.5±1.2 vs 1.7±1.2 g/dl, p&lt;0.01; 10.4 vs 15.9%, p&lt;0.01, respectively). Regarding safety endpoints, no differences were observed in the incidence of stroke and myocardial infarction between the groups (2.2 vs 2.6%, p=0.73 and 0.2 vs 0.4%, p=0.64, respectively). Multivariate regression analyses revealed that full antagonization of heparin (OR: 0.43 [95% CI: 0.24–0.81], p&lt;0.01) was independently associated with the primary end point

Conclusion

Full heparin antagonization resulted in significantly lower rates of life-threatening and major bleeding after TAVR as compared to partial heparin reversal. The occurrence of stroke and myocardial infarction was low and comparable between both groups.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).

PI 3-kinase isoform PI3Kalpha controls smooth muscle cell functionality and protects against aortic aneurysm formation

Background

Class I PI 3-kinase isoform PI3Kα is a lipid kinase and signals downstream of receptor tyrosine kinases. Smooth muscle cells (SMCs) lacking PI3Kα are characterized by impaired proliferation, migration and survival. Mice, harbouring a smooth muscle specific PI3Kα deficiency (SM-PI3Kα−/−), display reduced vascular wall thickness and impaired vascular remodeling in response to vessel injury. We hypothesize that SM-PI3Kα−/− mice are prone to aortic aneurysm (AA) formation due to impaired SMC functions. Herein, we investigated, how PI3Kα-dependent signaling in SMCs affect aortic aneurysm (AA) formation, aortic wall structure, and expression of extracellular matrix (ECM) components.

Methods and results

AA formation in SM-PI3Kα−/− mice and wild-type littermates was examined by means of the “porcine pancreatic elastase” (PPE) AA model. PPE was infused into the infrarenal aorta to induce AA formation. Ultrasound examination revealed a significantly increased aortic diameter in SM-PI3Kα−/− mice (1.22±0.12 mm) compared to wild-type animals (0.96±0.02 mm, p=0.014). These data indicate a protective function of SM-PI3Kα in AA formation. In addition, the media thickness in the abdominal aorta was significantly reduced in SM-PI3Kα−/− mice (29.0±3.1 vs. 42.5±4.1 μm). Ultrastructural analysis of aortic wall morphology in SM-PI3Kα−/−mice using transmission electron microscopy (TEM) showed a deranged tunica media with detached SMCs and increased apoptotic cell death. Consequently, SM-PI3Kα deficiency significantly diminished responsiveness of aortic rings to vasodilator acetylcholine and NO-donor nitroglycerin, further indicating impaired aortic wall structure. Western blots demonstrated a reduced elastin and fibrillin expression in SMCs from SM-PI3Kα−/− mice. Furthermore, immunofluorescence stainings of PI3Kα−/− and wild-type SMCs, cultured for seven days under 10% fetal calf serum containing DMEM medium, showed significantly disturbed structures of elastin-, fibrillin-1- and collagen-1-fibers. These data indicate that PI3Kα signaling contributes to elastic fiber homeostasis thus affecting SMC phenotypic modulation. Immunoblots demonstrated that PDGF and insulin induced phosphorylation and inactivation of key regulators of SMC differentiation and dedifferentiation including FoxO1, FoxO3a, Foxo4, and GSK3b, respectively, were reduced or even abrogated in PI3Kα−/− SMCs.

Conclusion

These data show that deficiency of PI3Kα in SMCs promotes the formation and progression of AA. Causative is a deranged aortic structure of SM-PI3Kα−/− aortae which can likely be attributed to an impaired production of elastic fiber components by PI3Kα−/− SMCs.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft

Risk prediction in patients with classical Low-flow, low-gradient aortic stenosis undergoing TAVI

Background

Patients with classical low-flow, low-gradient aortic stenosis (LFLG AS) undergoing transcatheter aortic valve implantation (TAVI) are known to suffer from poor prognosis. Risk prediction is difficult and predictors of outcome are scarce in this complex patient subset.

Purpose

This study aimed to develop a simple score system for risk prediction in patients with classical LFLG AS scheduled for TAVI including baseline clinical, echocardiographic and computed tomography (CT) parameters.

Methods

Among 9,150 patients undergoing TAVI (2008–2019) at five German centers, patients with classical LFLG AS were screened for availability of sufficient CT data for aortic valve calcification (AVC) quantification. Score variables were defined as all variables included into the best performing multivariable regression model. Score performance was assessed by Kaplan-Meier analysis for the endpoint of 1-year all-cause as well as c-index calculation.

Results

A total of 718 patients were included into the study. Predictors of all-cause mortality were male sex (HR 1.27 [0.98, 1.65], p=0.068), chronic obstructive pulmonary disease (HR 1.59 [1.21,2.08], p&lt;0.001), atrial fibrillation (HR 1.33 [1.03,1.70], p=0.026), stroke volume index (HR 0.96 [0.94, 0.98], p&lt;0.001), non-transfemoral access (HR 1.44 [1.09,1.91], p=0.011), pulmonary hypertension (HR 1.58 [1.20,2.08], p=0.0012) and low AVC density (HR 1.49 [1.16,1.90], p=0.0016). A score system was developed ranging from 0 points to 11 points. Kaplan-Meier analysis for low (0–2 points), moderate (3–6 points) and high score (&gt;6 points) demonstrated 1-year mortality rates of 20.9%, 28.9% and 64.3% (p&lt;0.001), respectively. C-index for prediction of 1-year mortality was 0.69 (95%-CI 0.65–0.84). The RELiEF TAVI score outperformed classical risk prediction models like the logistic euroSCORE (c-index 0.60 [95%-CI 0.51–0.72], p=0.013), the EuroSCORE II (c-index 0.57 [95%-CI 0.45–0.70], p=0.039) and the STS PROM (c-index 0.60 [0.48–0.70], p=0.035).

Conclusions

The RELiEF TAVI score is based on simple clinical, echocardiographic and CT parameters and might serve as a helpful tool for risk prediction in the vulnerable subset of patients with classical LFLG AS scheduled for TAVI.

Funding Acknowledgement

Type of funding sources: None. RELiEF TAVI Score

Periosteal Flaps Enhance Prefabricated Engineered Bone Reparative Potential

The clinical translation of bone tissue engineering for reconstructing large bone defects has not advanced without hurdles. The in vivo bioreactor (IVB) concept may therefore bridge between bone tissue engineering and reconstructive surgery by employing the patient body for prefabricating new prevascularized tissues. Ideally, IVB should minimize the need for exogenous growth factors/cells. Periosteal tissues are promising for IVB approaches to prefabricate tissue-engineered bone (TEB) flaps. However, the significance of preserving the periosteal vascular supply has not been adequately investigated. This study assessed muscle IVB with and without periosteal/pericranial grafts and flaps for prefabricating TEB flaps to reconstruct mandibular defects in sheep. The sheep (n = 14) were allocated into 4 groups: muscle IVB (M group; n_M = 3), muscle + periosteal graft (MP group; n_MP = 4), muscle + periosteal flap (MVP group; n_MVP = 4), and control group (n_Control = 3). In the first surgery, alloplastic bone blocks were implanted in the brachiocephalic muscle (M) with a periosteal graft (MP) or with a vascularized periosteal flap (MVP). After 9 wk, the prefabricated TEB flaps were transplanted to reconstruct a mandibular angle defect. In the control group, the defects were reconstructed by non-prevascularized bone blocks. Computed tomography (CT) scans were performed after 13 wk and after 23 wk at termination, followed by micro-CT (µCT) and histological analyses. Both CT and µCT analysis revealed enhanced new bone formation and decreased residual biomaterial volume in the MVP group compared with control and MP groups, while the M group showed less new bone formation and more residual biomaterial. The histological analysis showed that most of the newly formed bone emerged from defect edges, but larger areas of new bone islands were found in MP and MVP groups. The MVP group showed enhanced vascularization and higher biomaterial remodeling rates. The periosteal flaps boosted the reconstructive potential of the prefabricated TEB flaps. The regenerative potential of the periosteum was manifested after the transplantation into the mechanically stimulated bony defect microenvironment.

Steady state Kalman filter design for cases and deaths prediction of Covid-19 in Greece

In this work we study the applicability of the steady state Kalman filter in order to predict new cases and deaths of Covid-19. We use the actual observations of new cases and deaths. First, we deal with short term prediction, namely daily prediction. We propose the use of the golden steady state Kalman Filter, which is designed to have parameters related to the golden section. It was found that the proposed golden steady state Kalman Filter has a satisfactory behavior compared with the classical mean or average filter. Secondly, we deal with long term prediction, for example average prediction per quarantine period (14 days). We propose to process blocks of measurements of time window corresponding for example to the quarantine period in order to predict the average of cases and deaths using steady state Kalman Filter. It was found that the proposed golden steady state Kalman Filter produces more reliable predictions than the classical mean or average filter does. The use of steady state Kalman Filter for cases and deaths prediction of Covid-19 can be effective for resources and prevention measures planning.

Does Fragmentation of Care in Locally Advanced Rectal Cancer Increase Patient Mortality?

OBJECTIVE

To evaluate health care fragmentation in patients with stage II and III rectal cancers.

BACKGROUND

Fragmentation of care among multiple hospitals may worsen outcomes for cancer patients.

METHODS

National Cancer Database was queried for adult patients who underwent radiation and surgery for locally advanced (stage II-III) rectal adenocarcinoma from 2006 to 2015. Fragmented care was defined as receiving radiation at a different hospital from surgery. Descriptive statistics characterized patients, and survival probability was plotted using the Kaplan-Meier method and a Cox proportional hazards model.

RESULTS

A total of 37,081 patients underwent surgery and radiation for stage II-III rectal cancer from 2006 to 2015 (24,102 integrated care vs. 12,979 fragmented care). Patients who received fragmented care (hazard ratio [HR] 1.105; 95% CI 1.045-1.169) had a higher risk of mortality. Patients who received at least surgery (HR 0.84; 95% CI 0.77-0.92) at academic hospitals had a lower risk of mortality. Academic hospitals had a higher proportion of patients with fragmented care (38.0 vs. comprehensive community 32.8% vs. community 33.8%, p < 0.001). Within academic hospitals, fragmented care portended worse survival (integrated academic 80.0% vs. fragmented academic 76.7%, p = 0.0002). Fragmented care at academic hospitals had increased survival over integrated care at community hospitals (fragmented academic 76.7 vs. integrated community 72.2%, p = 0.00039).

CONCLUSIONS

In patients with stage II-III rectal cancer, patients who have integrated care at academic hospitals or at least surgery at academic centers had better survival. All efforts should be made to reduce care fragmentation and surgery at academic centers should be prioritized.

Phenotypic plasticity of plant traits contributing to grain and biomass yield of dual-purpose sorghum

Plant traits of interest for sorghum breeders to develop dual-purpose varieties are stem diameter, flag leaf size, crop cycle, and number of grains per panicle. To develop dual-purpose varieties, breeders need to improve traits linked both to grain and biomass production. To identify these traits, we studied the phenotypic plasticity of eighteen traits and the performance of ten contrasting sorghum genotypes, used in West Africa. Trials were carried out in a randomized complete blocks design with four replicates from 2013 to 2016 in Bambey, Sinthiou Malem and Nioro du Rip in Senegal. The results revealed three plant types. The first type, "biomass production", contained genotypes IS15401 and SK5912, and was linked to cycle duration, leaf area, and plant height. The second type, "grain production", grouped the caudatum race sorghum 621B, F2-20 and Soumba, and was associated with the number of grains per panicle and the width of the flag leaf. The third group, "dual-purpose", corresponding to the genotypes Fadda, Nieleni and Pablo, combined some favourable traits for grain and biomass: stem diameter, internode length, number of green leaves and number of grains per panicle. The study showed that high and stable grain yields were associated with stability in flag leaf size, phenology and number of grains per panicle, and a high and stable biomass yield was associated with stability in stem diameter. Those stable plant traits might be of interest for sorghum breeders selecting to develop dual-purpose varieties.

Lack of PI 3-kinase isoform p110alpha in smooth muscle cells impairs aortic wall homoeostasis and thus promotes aortic aneurysm formation

Background

In smooth muscle cells (SMCs), the PI 3-kinase isoform p110α mediates receptor tyrosine kinase dependent proliferation, chemotaxis and cell survival. Since mice, harbouring a smooth muscle specific p110α deficiency (SM-p110α−/−), display reduced vascular wall thickness, we hypothesized that SM-p110α−/− mice might be prone to aortic aneurysm (AA) formation. The pathogenesis of AA is characterized by increased dedifferentiation of SMCs, extracellular matrix (ECM) degeneration and inflammation in the aortic wall. Herein, we investigated how p110α-dependent signal transduction in SMCs affects these processes.

Methods and results

We examined AA formation in SM-p110α−/− mice and wild-type littermates using the “porcine pancreatic elastase” (PPE) AA model. PPE was infused into the infrarenal aorta to induce AA formation. Ultrasound examination of the aorta revealed an enlarged aortic diameter in all PPE-treated mice. The aortic diameter in SM-p110α−/− mice (0.46±0.12 mm) was significantly increased compared to wild-type animals (0.18±0.03 mm, p&lt;0.01). These data indicate a protective function of p110α in AA formation. Immunocytochemical examination of the tunica media of PPE-perfused SM-p110α−/− mice revealed significantly increased infiltration of CD45+ leukocytes. In particular, the number of MOMA-2+ monocytes / macrophages in the vessel wall was significantly increased indicating elevated inflammation of the aortic wall during AA progression in comparison to wild-type control mice. Ultrastructural analysis of aortic wall morphology in SM-p110α−/− mice using transmission electron microscopy (TEM) showed a deranged tunica media and increased apoptotic cell death. In addition, the media thickness in the abdominal aorta was significantly reduced in SM-p110α−/− mice (29.0±3.1 μm vs. 42.5±4.1 μm). Western blots demonstrated a reduced elastin and fibrillin expression in SMCs from SM-p110α−/− mice. p110α−/− SMCs showed significantly reduced expression of differentiation markers SM-α-actin and SM-MHC. In addition, aortic p110α-deficient SMCs were significantly impaired in their ability to proliferate and migrate. These findings indicate that p110α−/− SMCs are neither differentiated nor dedifferentiated and have therefore largely lost their plasticity. Consequently, p110α deficiency significantly diminished responsiveness of aortic rings to vasodilator acetylcholine and NO-donor nitroglycerin, further indicating impaired contractility of SMCs. Mechanistically, we demonstrated that PDGF and insulin induced phosphorylation and inactivation of key regulators of SMC differentiation and dedifferentiation, Foxo4 and GSK3b, respectively, were abrogated in p110α−/− SMCs.

Conclusion

These data show that deficiency of p110α in SMCs promotes the formation and progression of AA. Causative are impaired SMC plasticity and ECM homeostasis as well as inflammatory processes in the vascular wall.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG)

Stroke and mortality rates after valve-in-valve TAVR and comparison with data from redo SAVR

Background and purpose

Early registry data described a potentially increased risk for cerebrovascular events and mortality in patients undergoing transcatheter aortic valve replacement (TAVR) as valve-in-valve (viv) procedures. Further data of small patient cohorts described divergent results for cerebrovascular events and mortality in patients undergoing TAVR as viv procedures for failed surgical bioprotheses in comparison with patients on redo surgical aortic valve replacement (SAVR). We performed a meta-analysis of stroke rates and mortality for viv TAVR procedures basing on the current literature.

Methods

We included all case series (≥10 patients), case-control studies and randomized controlled trials comparing viv TAVR and redo SAVR procedures with respect to cerebrovascular events and mortality rates. Additionally, we included all case series and registries with patients undergoing viv TAVR. After a structured literature research, 17 studies were eligible. For statistical analysis risk ratios and confidence intervals using Mantel-Haenszel test and the I-statistic to quantify possible heterogeneity were calculated. A P-value &lt;0.05 was defined as statistical significant difference.

Results

Eleven case series and registries reporting on stroke and mortality in 8,509 patients undergoing viv TAVR were eligible for analysis. The quantitative analysis of non-comparative studies showed a calculated 30-day stroke rate of 2.2% and 30-day mortality rate of 4.2% after viv TAVR. Data on the 1-year rates were sporadically reported, therefore meta analysis was not appropriately feasible.

Six studies reporting on 498 participants undergoing viv TAVR (N=254) and redo SAVR (N=244) were eligible. The median age ranged from 72.3 to 80.2 years for viv TAVR and from 66.2 to 78.8 years for redo SAVR patients. The STS score was 7.2–7.4% (viv TAVR) and 5.8–7.7% (redo SAVR), respectively. A total of 3/226 participants treated with viv TAVR and 4/214 patients undergoing redo SAVR experienced a stroke during the first 30 postoperative days (N=4 trials, RR 0.86, 95% CI 0.20 to 3.59, p=0.83, I2 = 0%). None of the studies reported sufficient data on the 1-year stroke incidence. The 30-day mortality was 4.3% for viv TAVR and 4.5% for redo SAVR patients. This difference was not significantly different (N=6 trials, RR 0.90, 95% CI 0.40 to 2.05, p=0.80, I2 = 0%). The 1-year mortality rates were 13.3% and 13.6%, respectively (N=2 trials, RR 0.98, 95% CI 0.49 to 1.94, p=0.94, I2 = 0%).

Conclusion

In the current literature favorable stroke and mortality rates at 30 days for patients undergoing viv TAVR are documented. Similar stroke and mortality rates comparing viv TAVR and redo SAVR patients at 30 days were found as well as similar 1-year mortality. A selection bias for the viv TAVR and redo SAVR patients may exist, but cannot be dissolved with this registry analysis, only showing a trend of younger and lower risk patients receiving a redo SAVR procedure.

Funding Acknowledgement

Type of funding source: None

Modelling climate change impacts on maize yields under low nitrogen input conditions in sub-Saharan Africa

Smallholder farmers in sub-Saharan Africa (SSA) currently grow rainfed maize with limited inputs including fertilizer. Climate change may exacerbate current production constraints. Crop models can help quantify the potential impact of climate change on maize yields, but a comprehensive multimodel assessment of simulation accuracy and uncertainty in these low-input systems is currently lacking. We evaluated the impact of varying [CO₂ ], temperature and rainfall conditions on maize yield, for different nitrogen (N) inputs (0, 80, 160 kg N/ha) for five environments in SSA, including cool subhumid Ethiopia, cool semi-arid Rwanda, hot subhumid Ghana and hot semi-arid Mali and Benin using an ensemble of 25 maize models. Models were calibrated with measured grain yield, plant biomass, plant N, leaf area index, harvest index and in-season soil water content from 2-year experiments in each country to assess their ability to simulate observed yield. Simulated responses to climate change factors were explored and compared between models. Calibrated models reproduced measured grain yield variations well with average relative root mean square error of 26%, although uncertainty in model prediction was substantial (CV = 28%). Model ensembles gave greater accuracy than any model taken at random. Nitrogen fertilization controlled the response to variations in [CO₂ ], temperature and rainfall. Without N fertilizer input, maize (a) benefited less from an increase in atmospheric [CO₂ ]; (b) was less affected by higher temperature or decreasing rainfall; and (c) was more affected by increased rainfall because N leaching was more critical. The model intercomparison revealed that simulation of daily soil N supply and N leaching plays a crucial role in simulating climate change impacts for low-input systems. Climate change and N input interactions have strong implications for the design of robust adaptation approaches across SSA, because the impact of climate change in low input systems will be modified if farmers intensify maize production with balanced nutrient management.

Pulmonary hypertension and valvular heart disease

Pulmonary hypertension (PH) is an important contributor to morbidity and mortality in patients with left-sided heart disease, including valvular heart disease. In this context, elevated left atrial pressure primarily leads to the development of post-capillary PH. Despite the fact that repair of left-sided valvular heart disease by surgical or interventional approaches will improve PH, recent studies have highlighted that PH (pre- or post-interventional) remains an important predictor of long-term outcome. Here, we review the current knowledge on PH in valvular heart disease taking into account new hemodynamic PH definitions, and the distinction between post- and pre-capillary components of PH. A specific focus is on the precise characterization of hemodynamics and cardiopulmonary interaction, and on potential strategies for the management of residual PH after mitral or aortic valve interventions. In addition, we highlight the clinical significance of tricuspid regurgitation, which may occur as a primary condition or as a consequence of PH and right heart dilatation (functional). In this context, proper patient selection for potential tricuspid valve interventions is crucial. Finally, the article highlights gaps in evidence, and points toward future perspectives.

P5987Novel model of intensity graded murine wire-induced aortic valve stenosis mimics distinct stages of human aortic valve pathology

Background

Aortic valve stenosis (AS) is the most common valve disease requiring therapeutic intervention. Even though the incidence of AS has been continuously rising and AS is associated with significant morbidity and mortality, to date, no medical treatments have been identified that can modify disease progression. In fact, only invasive interventional or surgical replacement of severely diseased valves is recommended. This unmet medical need is likely attributed to the lack of a clear understanding of the molecular mechanism driving disease development. To investigate the pathophysiology leading to AS, reliable and reproducible animal models that mimic human pathophysiology are needed.

Hypothesis

Induction of a graded wire-induced aortic valve stenosis model in mice is feasible to reflect and study pathophysiological mechanisms underlying the progression of aortic valve stenosis.

Methods

We have tested and expanded the protocols of a novel wire-injury induced aortic valve stenosis mouse model. A spring coronary guide wire or a bare metal wire was used to apply shear stress to the aortic valve cusps with increasing intensity with ultrasound-guided monitoring in male 10 to 12-week-old C57Bl/6j mice. These protocols allowed the induction of distinct models with soft, moderate and intense wire injury. Functional analysis including maximum flow velocity (Vmax), ejection fraction, fractional shortening, left ventricular volumes, diameters and wall thickness were assessed by echocardiography before, one and four weeks after induction of aortic valve stenosis. Immunohistological analysis were performed after eight weeks (hematoxylin and eosin, von-Kossa staining, anti-CD68-staining).

Results

Upon moderate or severe injury, AS developed with a significant increase in aortic valve peak blood flow velocity. While moderate injury promoted solitary AS, severe-injury induced mixed aortic valve disease with concomitant mild to moderate aortic regurgitation. Only 5% of the mice who received a moderate injury displayed a mild aortic regurgitation. In the group of mice with intense injury 50% of the mice had a mild and 18,75% had a moderate aortic insufficiency. The changes in aortic valve function were reflected by dilation and hypertrophy of the left ventricle, as well as a decreased left ventricular ejection fraction after intense injury, while moderate injury did not show significant dilation of the left ventricle. Histological analysis revealed the three classic hallmarks of human disease with aortic valve thickening, increased macrophage infiltration and calcification eight weeks after injury.

Conclusion

Hereby, we demonstrate that the induction of a graded wire induced aortic valve stenosis model in mice mimicking relevant pathophysiological mechanisms is feasible to study disease progression. We extended existing protocols to induce moderate stenosis allowing to solely study aortic valve stenosis without relevant aortic valve regurgitation.

Acknowledgement/Funding

S.N. was funded by Else-Kröner-Fresenius-Foundation of the Medical Faculty of the University of Bonn

P5434P300-mediated inactivation of p53 protects against doxorubicin-induced cardiotoxicity

Introduction

Doxorubicin is amongst the most widely prescribed chemotherapy drugs due to its effectiveness in cancer treatment. However, progressive treatment using doxorubicin severely increases the risk of congestive heart failure. Mechanistically, researchers have shown that doxorubicin (i) intercalates into DNA and disrupts topoisomerase-II-mediated DNA repair and (ii) generates free radicals which then causes damage to cellular membranes, DNA, and proteins. Ultimately these cellular insults induce cardiomyocyte (CM) death mediated by the tumour suppressor, p53. Currently, there are no clinically applicable preventative treatments for doxorubicin-induced cardiotoxicity and so, extensive research is being done in discovering a potential therapy. One such candidate is curcumin – a natural polyphenol compound non-toxic to humans. We have previously demonstrated that curcumin inhibits lysine acetyltransferase activity of p300, therefore reducing both histone and non-histone protein acetylation. To induce CM death, p53 requires acetylation by p300. Therefore, we hypothesize that curcumin protects against doxorubicin-induced CM death and cardiotoxicity via p300-mediated inactivation of p53.

Methods

Rat H9c2 cardiomyoblast cells were cultured and treated with a 2.5 μM dose of doxorubicin for 16 hours. One group of cells were pre-treated with curcumin (15μM) 4 hours prior to doxorubicin treatment, and controls were cultured with only diluent added. Following treatment, the cells were harvested for total protein. At end point, we performed immunoblotting to measure protein expression of key proteins involved in DNA damage (y-H2A.X, p53), and apoptosis (cleaved-Caspase 3).

Results

Our findings show that following doxorubicin treatment, p53 expression was significantly increased (p<0.001), confirming its role in doxorubicin-associated cardiotoxicity. Furthermore, doxorubicin was associated with increased DNA-damage as evidenced by increased expression and activation of DNA double-stranded breaks (DSBs) marker, y-H2A.X (p<0.001). Elevated levels of DNA-damage were further associated with significantly increased doxorubicin-induced apoptosis as measured by immunoblotting for cleaved-Caspase 3 (p<0.001). However, DNA-damage and apoptosis were attenuated by pre-treatment of cells with curcumin. Curcumin treatment led to a significant decrease in both y-H2A.X (p<0.01) and cleaved-Caspase 3 (p<0.01) expression compared to cells treated with only doxorubicin.

Conclusions

Our data provides the first evidence that curcumin protects against doxorubicin-induced apoptosis in rat cardiomyoblast cells in vitro. Further studies are warranted in vivo to confirm the potential of curcumin as a cardio-protective drug. Curcumin is a natural compound with little to no side-effects in humans, therefore our finding may provide a novel therapeutic target and treatment approach for doxorubicin-associated cardiotoxicity.

Acknowledgement/Funding

Heart & Stroke Foundation of Canada