Mechanism based therapies enable personalised treatment of hypertrophic cardiomyopathy.

Cardiomyopathies have unresolved genotype-phenotype relationships and lack disease-specific treatments. Here we provide a framework to identify genotype-specific pathomechanisms and therapeutic targets to accelerate the development of precision medicine. We use human cardiac electromechanical in-silico modelling and simulation which we validate with experimental hiPSC-CM data and modelling in combination with clinical biomarkers. We select hypertrophic cardiomyopathy as a challenge for this approach and study genetic variations that mutate proteins of the thick (MYH7R403Q/+) and thin filaments (TNNT2R92Q/+, TNNI3R21C/+) of the cardiac sarcomere. Using in-silico techniques we show that the destabilisation of myosin super relaxation observed in hiPSC-CMs drives disease in virtual cells and ventricles carrying the MYH7R403Q/+ variant, and that secondary effects on thin filament activation are necessary to precipitate slowed relaxation of the cell and diastolic insufficiency in the chamber. In-silico modelling shows that Mavacamten corrects the MYH7R403Q/+ phenotype in agreement with hiPSC-CM experiments. Our in-silico model predicts that the thin filament variants TNNT2R92Q/+ and TNNI3R21C/+ display altered calcium regulation as central pathomechanism, for which Mavacamten provides incomplete salvage, which we have corroborated in TNNT2R92Q/+ and TNNI3R21C/+ hiPSC-CMs. We define the ideal characteristics of a novel thin filament-targeting compound and show its efficacy in-silico. We demonstrate that hybrid human-based hiPSC-CM and in-silico studies accelerate pathomechanism discovery and classification testing, improving clinical interpretation of genetic variants, and directing rational therapeutic targeting and design.

The Accuracy of Sequential Urethral Frozen Section and its Impact on Urethral Recurrence After Radical Cystectomy.

OBJECTIVE: To assess the accuracy of frozen section analysis (FSA) for detecting and eliminating malignant urethral margins during radical cystectomy (RC) for bladder cancer (BC) and its impact on urethral recurrence. METHODS: Urethral margins were initially examined by FSA in 217 patients at RC. When positive, additional resections were performed. Subsequently, all specimens were re-examined on formalin-fixed, paraffin-embedded sections (FFPE). Malignancy was defined as either the presence of carcinoma in situ, high-grade or invasive tumor cells at the urethral margin. Kaplan-Meier analysis was used to assess the impact of the final urethral margin status on urethral recurrence. Multinomial logistic regression addressed independent risk factors for a positive final urethral margin. RESULTS: At initial examination, urethral margins were positive on FSA and FFPE in 21 (9.7%) and 17 (7.8) patients, respectively. The corresponding sensitivity, specificity, positive and negative predictive values were 88.2%, 97.0%, 71.4% and 99.0% (overall accuracy: 96.3%). After initial FSA, 23 patients (including 2 with equivocal histological findings) received re-resections (median: 1, total range: 1-3). Persistent positive margins were detected on FSA in 10 (43.5%) while none of these margins were positive on FFPE (overall accuracy: 52.2%). A positive urethral FSA at initial assessment was the only independent risk for a positive final urethral margin. The 3-year urethral recurrence-free survival was 99.1% for patients with negative margins on initial assessment (I), 100% for those with negative final margins after re-resection (II) and 83.3% for patients with positive final margins (III; P= .013 for I/II vs. III). CONCLUSIONS: The accuracy of FSA for detecting malignant urethral margins is high on initial examination but drops considerably in case of re-resection while most positive margins at initial FSA are converted to negative final ones on FFPE. Conversion of a positive to a negative margin was associated with a lower risk of urethral recurrence.

Specific Bacterial Pathogen Phytosensing Is Enabled by a Synthetic Promoter-Transcription Factor System in Potato.

Phytosensors are genetically engineered plant-based sensors that feature synthetic promoters fused to reporter genes to sense and report the presence of specific biotic and abiotic stressors on plants. However, when induced reporter gene output is below detectable limits, owing to relatively weak promoters, the phytosensor may not function as intended. Here, we show modifications to the system to amplify reporter gene signal by using a synthetic transcription factor gene driven by a plant pathogen-inducible synthetic promoter. The output signal was unambiguous green fluorescence when plants were infected by pathogenic bacteria. We produced and characterized a phytosensor with improved sensing to specific bacterial pathogens with targeted detection using spectral wavelengths specific to a fluorescence reporter at 3 m standoff detection. Previous attempts to create phytosensors revealed limitations in using innate plant promoters with low-inducible activity since they are not sufficient to produce a strong detectable fluorescence signal for standoff detection. To address this, we designed a pathogen-specific phytosensor using a synthetic promoter-transcription factor system: the S-Box cis-regulatory element which has low-inducible activity as a synthetic 4xS-Box promoter, and the Q-system transcription factor as an amplifier of reporter gene expression. This promoter-transcription factor system resulted in 6-fold amplification of the fluorescence after infection with a potato pathogen, which was detectable as early as 24 h post-bacterial infection. This novel bacterial pathogen-specific phytosensor potato plant demonstrates that the Q-system may be leveraged as a powerful orthogonal tool to amplify a relatively weak synthetic inducible promoter, enabling standoff detection of a previously undetectable fluorescence signal. Pathogen-specific phytosensors would be an important asset for real-time early detection of plant pathogens prior to the display of disease symptoms on crop plants.

The Predictive and Prognostic Value of Precystectomy Serum Gamma-Glutamyltransferase Levels in Patients With Invasive Bladder Cancer.

INTRODUCTION: The aim of the study was to elucidate the predictive and prognostic value of serum gamma-glutamyltransferase (GGT) in patients with invasive bladder cancer (BC). PATIENTS AND METHODS: Preoperative serum GGT concentrations were assessed in 324 patients treated with RC for cM0 BC between 2002 and 2013. Laboratory values were obtained 1 to 3 days prior to RC. Uni- and multivariable analyses were carried out to evaluate clinicopathologic risk factors for survival. The median follow-up was 36 months (IQR: 10-55). RESULTS: Elevated preoperative GGT levels were diagnosed in 77 patients (23.8%). Elevated GGT was significantly associated with higher ECOG PS and tumor stage (both P = .001), lymph-node tumor involvement (P < .001), positive surgical margins (P = .018), lymphovascular invasion (P = .024), muscle-invasive disease at primary diagnosis (P = .033), increased tumor size (P = .035), hydronephrosis at RC (P = .049) and increased preoperative CRP, GPT and GOT levels (both P < .001). Patients with elevated GGT had decreased 3-year overall (49.2% vs. 69.6%; P = .005) and cancer-specific survival (71.1% vs. 80.9%; P = .042) compared with patients with normal levels. On multivariable analysis, advanced tumor stage (P = .032), lymph node positive disease (P = .030), positive soft tissue surgical margins (P = .014), hydronephrosis at RC (both P = .010), higher ECOG performance status and elevated GGT (P = .043) levels were independent predictors of all-cause mortality. CONCLUSION: Elevated preoperative serum GGT levels are associated with increased risk of locally advanced BC and mortality after RC. These data suggest that GGT levels may be useful for improved prognostication in invasive BC.

Cell cycle defects underlie childhood-onset cardiomyopathy associated with Noonan syndrome.

Childhood-onset myocardial hypertrophy and cardiomyopathic changes are associated with significant morbidity and mortality in early life, particularly in patients with Noonan syndrome, a multisystemic genetic disorder caused by autosomal dominant mutations in genes of the Ras-MAPK pathway. Although the cardiomyopathy associated with Noonan syndrome (NS-CM) shares certain cardiac features with the hypertrophic cardiomyopathy caused by mutations in sarcomeric proteins (HCM), such as pathological myocardial remodeling, ventricular dysfunction, and increased risk for malignant arrhythmias, the clinical course of NS-CM significantly differs from HCM. This suggests a distinct pathophysiology that remains to be elucidated. Here, through analysis of sarcomeric myosin conformational states, histopathology, and gene expression in left ventricular myocardial tissue from NS-CM, HCM, and normal hearts complemented with disease modeling in cardiomyocytes differentiated from patient-derived PTPN11 N308S/+ induced pluripotent stem cells, we demonstrate distinct disease phenotypes between NS-CM and HCM and uncover cell cycle defects as a potential driver of NS-CM.

CalTrack: High-Throughput Automated Calcium Transient Analysis in Cardiomyocytes.

[Figure: see text].

Cardiac myosin super relaxation (SRX): a perspective on fundamental biology, human disease and therapeutics.

The fundamental basis of muscle contraction 'the sliding filament model' (Huxley and Niedergerke, 1954; Huxley and Hanson, 1954) and the 'swinging, tilting crossbridge-sliding filament mechanism' (Huxley, 1969; Huxley and Brown, 1967) nucleated a field of research that has unearthed the complex and fascinating role of myosin structure in the regulation of contraction. A recently discovered energy conserving state of myosin termed the super relaxed state (SRX) has been observed in filamentous myosins and is central to modulating force production and energy use within the sarcomere. Modulation of myosin function through SRX is a rapidly developing theme in therapeutic development for both cardiovascular disease and infectious disease. Some 70 years after the first discoveries concerning muscular function, modulation of myosin SRX may bring the first myosin targeted small molecule to the clinic, for treating hypertrophic cardiomyopathy (Olivotto et al., 2020). An often monogenic disease HCM afflicts 1 in 500 individuals, and can cause heart failure and sudden cardiac death. Even as we near therapeutic translation, there remain many questions about the governance of muscle function in human health and disease. With this review, we provide a broad overview of contemporary understanding of myosin SRX, and explore the complexities of targeting this myosin state in human disease.This article has an associated Future Leaders to Watch interview with the authors of the paper.

Determinants for voluntary participation in staff screening during an methicillin-resistant Staphylococcus aureus (MRSA) outbreak on a neonatal ward.

We investigated healthcare worker (HCW) behavior with regard to a voluntary methicillin-resistant Staphylococcus aureus (MRSA) staff screening during a MRSA outbreak in a neonatal ward. Avoiding MRSA transmission from HCWs to patients was the most important reason for participation. Inconvenient screening time was the most frequently cited reason for nonparticipation.

Imaging of multiple fluorescent proteins in canopies enables synthetic biology in plants.

Reverse genetics approaches have revolutionized plant biology and agriculture. Phenomics has the prospect of bridging plant phenotypes with genes, including transgenes, to transform agricultural fields. Genetically encoded fluorescent proteins (FPs) have revolutionized plant biology paradigms in gene expression, protein trafficking and plant physiology. While the first instance of plant canopy imaging of green fluorescent protein (GFP) was performed over 25 years ago, modern phenomics has largely ignored fluorescence as a transgene expression device despite the burgeoning FP colour palette available to plant biologists. Here, we show a new platform for stand-off imaging of plant canopies expressing a wide variety of FP genes. The platform-the fluorescence-inducing laser projector (FILP)-uses an ultra-low-noise camera to image a scene illuminated by compact diode lasers of various colours, coupled with emission filters to resolve individual FPs, to phenotype transgenic plants expressing FP genes. Each of the 20 FPs screened in plants were imaged at >3 m using FILP in a laboratory-based laser range. We also show that pairs of co-expressed fluorescence proteins can be imaged in canopies. The FILP system enabled a rapid synthetic promoter screen: starting from 2000 synthetic promoters transfected into protoplasts to FILP-imaged agroinfiltrated Nicotiana benthamiana plants in a matter of weeks, which was useful to characterize a water stress-inducible synthetic promoter. FILP canopy imaging was also accomplished for stably transformed GFP potato and in a split-GFP assay, which illustrates the flexibility of the instrument for analysing fluorescence signals in plant canopies.

GATA6 mutations in hiPSCs inform mechanisms for maldevelopment of the heart, pancreas, and diaphragm.

Damaging GATA6 variants cause cardiac outflow tract defects, sometimes with pancreatic and diaphragmic malformations. To define molecular mechanisms for these diverse developmental defects, we studied transcriptional and epigenetic responses to GATA6 loss of function (LoF) and missense variants during cardiomyocyte differentiation of isogenic human induced pluripotent stem cells. We show that GATA6 is a pioneer factor in cardiac development, regulating SMYD1 that activates HAND2, and KDR that with HAND2 orchestrates outflow tract formation. LoF variants perturbed cardiac genes and also endoderm lineage genes that direct PDX1 expression and pancreatic development. Remarkably, an exon 4 GATA6 missense variant, highly associated with extra-cardiac malformations, caused ectopic pioneer activities, profoundly diminishing GATA4, FOXA1/2, and PDX1 expression and increasing normal retinoic acid signaling that promotes diaphragm development. These aberrant epigenetic and transcriptional signatures illuminate the molecular mechanisms for cardiovascular malformations, pancreas and diaphragm dysgenesis that arise in patients with distinct GATA6 variants.

Prognostic significance of previous tonsillectomy after radical cystectomy for bladder cancer.

Introduction: To examine whether previous tonsillectomy (TE) impacts on survival after radical cystectomy (RC) for bladder cancer (BC).Patients and Methods: A total of 320 patients were staged cM0 and underwent RC for BC between 2002 and 2013. We retrospectively investigated whether patients had undergone TE prior to RC. Chi-square/Fisher-Exact test was carried out to compare clinicopathological features between the TE- and non-TE-group. Kaplan-Meier analysis with log-rank test was used to estimate recurrence-free survival (RFS) and multivariable Cox-regression analysis of risk factors of recurrence. The median follow-up was 31 months (interquartile range: 9-54).Results: A history of TE was present in 18 of the 320 patients (5.6%). All TEs were performed for benign conditions. TE prior to RC was associated with a history of appendectomy (p = 0.045), lower age at RC (p = 0.029), tumor unifocality (p < 0.001), advanced histopathological tumor stage (p = 0.015), non-pure urothelial carcinoma (p = 0.025), lymphovascular invasion (p = 0.035) and receipt of palliative chemotherapy (p = 0.004). The 3-year RFS was 39.2% for patients with previous TE and 62.4% for those without (p = 0.008). In multivariable analysis, adjusted for all significant parameters of univariable analysis, lymph-node tumor involvement (p = 0.017), positive surgical margins (p = 0.047), tumor grade (p = 0.032), advanced tumor stage (≥pT3a; p = 0.049) and a history of TE (p = 0.021) remained independent prognosticators of recurrence.Conclusion: In this series, previous TE was an independent predictor of recurrence after RC for BC. Further studies are needed to assess whether TE induces immunological alterations that might exert adverse effects on cancer progression of patients with invasive BC.

The Q-System as a Synthetic Transcriptional Regulator in Plants.

A primary focus of the rapidly growing field of plant synthetic biology is to develop technologies to precisely regulate gene expression and engineer complex genetic circuits into plant chassis. At present, there are few orthogonal tools available for effectively controlling gene expression in plants, with most researchers instead using a limited set of viral elements or truncated native promoters. A powerful repressible-and engineerable-binary system that has been repurposed in a variety of eukaryotic systems is the Q-system from Neurospora crassa. Here, we demonstrate the functionality of the Q-system in plants through transient expression in soybean (Glycine max) protoplasts and agroinfiltration in Nicotiana benthamiana leaves. Further, using functional variants of the QF transcriptional activator, it was possible to modulate the expression of reporter genes and to fully suppress the system through expression of the QS repressor. As a potential application for plant-based biosensors (phytosensors), we demonstrated the ability of the Q-system to amplify the signal from a weak promoter, enabling remote detection of a fluorescent reporter that was previously undetectable. In addition, we demonstrated that it was possible to coordinate the expression of multiple genes through the expression of a single QF activator. Based on the results from this study, the Q-system represents a powerful orthogonal tool for precise control of gene expression in plants, with envisioned applications in metabolic engineering, phytosensors, and biotic and abiotic stress tolerance.

Prognostic impact of tumor-associated immune cell infiltrates at radical cystectomy for bladder cancer.

OBJECTIVES: To assess whether the presence and location of tumor-associated immune cell infiltrates (TAIC) on histological slides obtained from cystectomy specimens impacts on oncological outcomes of patients with bladder cancer (BC). MATERIAL AND METHODS: A total of 320 consecutive patients staged with cM0 bladder cancer underwent radical cystectomy (RC) between 2004 and 2013. The presence of TAIC (either located peritumorally [PIC] and/or intratumorally [IIC]) on histological slides was retrospectively assessed and correlated with outcomes. Kaplan-Meier analyses were used to estimate the impact of TAIC on recurrence-free (RFS), cancer-specific (CSS), and overall survival (OS). Multivariable Cox-regression analysis was carried out to evaluate risk factors of recurrence. The median follow-up was 37 months (IQR: 10-55). RESULTS: Of the 320 patients, 42 (13.1%) exhibited IIC, 141 (44.1%) PIC and 137 (42.8%) no TAIC in the cystectomy specimens. Absence of TAIC was associated with higher ECOG performance status (P = 0.042), histologically advanced tumor stage (≥pT3a; P < 0.001), lymph node tumor involvement (pN+; P = 0.022), positive soft tissue surgical margins (P = 0.006), lymphovascular invasion (P < 0.001), and elevated serum C-reactive protein levels (P < 0.001). The rate of never smokers was significantly higher in the IIC-group (64.3%) compared to the PIC-group (39.7%, P = 0.007) and those without TAIC (35.8%, P = 0.001). The 3-year RFS/CSS/OS was 73.9%/88.5%/76.7% for patients with IIC, 69.4%/85.2%/70.1% for PIC and 47.6%/68.5%/56.1% for patients without TAIC (P < 0.001/<0.001/0.001 for TAIC vs. no TAIC). In multivariable analysis, adjusted for all significant parameters of univariable analysis, histologically advanced tumor stage (P = 0.003), node-positive disease (P = 0.002), and the absence of TAIC (P = 0.035) were independent prognosticators for recurrence. CONCLUSIONS: In this analysis, the presence and location of TAIC in cystectomy specimens was a strong prognosticator for RFS after RC. This finding suggests that the capability of immune cells to migrate into the tumor at the time of RC is prognostically important in invasive bladder cancer.

The prognostic impact of hexaminolevulinate-based bladder tumor resection in patients with primary non-muscle invasive bladder cancer treated with radical cystectomy.

PURPOSE: To investigate whether hexaminolevulinate-based (HAL) bladder tumor resection (TURBT) impacts on outcomes of patients with primary non-muscle-invasive bladder cancer (NMIBC) who were eventually treated with radical cystectomy (RC). METHODS: A total of 131 consecutive patients exhibiting NMIBC at primary diagnosis were retrospectively investigated whether they had undergone any HAL-guided TURBT prior to RC. Uni- and multivariable analyses were used to evaluate the impact of HAL-TURBT on cancer-specific (CSS) and overall survival (OS). The median follow-up was 38 months (IQR 13-56). RESULTS: Of the 131 patients, 69 (52.7%) were managed with HAL- and 62 (47.3%) with white light (WL)-TURBT only prior to RC. HAL-TURBT was associated with a higher number of TURBTs prior to RC (p = 0.002) and administration of intravesical chemotherapy (p = 0.043). A trend towards a higher rate of tumor-associated immune cell infiltrates in RC specimens (p = 0.07) and a lower utilization rate of post-operative systemic chemotherapy (p = 0.10) was noted for patients who were treated with HAL-TURBT. The 5-year CSS/OS was 90.9%/74.5% for the HAL-group and 73.8%/55.8% for the WL-group (p = 0.042/0.038). In multivariable analysis, lymph node tumor involvement (p = 0.007), positive surgical margins (p = 0.001) and performance of WL-TURBT only (p = 0.040) were independent predictors for cancer-specific death. CONCLUSIONS: The present data suggest that the resection of NMIBC under HAL exerts a beneficial impact on outcomes of patients who will need to undergo RC during their course of disease. This finding may be due to improved risk stratification as the resection under HAL may allow more patients to be treated timely and adequately.

Volume Averaging for Urban Canopies.

When canopy flows are horizontally averaged to obtain mean profiles, the averaging operation can be defined either as an intrinsic average, normalized by the variable fluid volume, or as a superficial average, normalized by the total volume including solid canopy elements. Properties of spatial averages have been explored extensively in the context of flow through plant canopies, albeit with the assumption that the solid volume fraction is negligible. Without this simplification, properties relevant for non-linear terms apply to intrinsic averages while properties of gradients apply to superficial averages. To avoid inconsistencies and inaccuracies the impact of a non-negligible solid volume fraction should be considered carefully when interpreting mean profiles, when deriving mathematical relations for averaged quantities, and when introducing modelling assumptions for such terms. On this basis, we review the definitions and properties of the method of volume averaging, as developed in the more general context of flow through porous media, and discuss its application to urban canopy flows. We illustrate the properties of intrinsic and superficial averages and their effect on mean profiles with example data from a simulation of flow over constant-height cubes.

SarcTrack.

RATIONALE: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in combination with CRISPR/Cas9 genome editing provide unparalleled opportunities to study cardiac biology and disease. However, sarcomeres, the fundamental units of myocyte contraction, are immature and nonlinear in hiPSC-CMs, which technically challenge accurate functional interrogation of contractile parameters in beating cells. Furthermore, existing analysis methods are relatively low-throughput, indirectly assess contractility, or only assess well-aligned sarcomeres found in mature cardiac tissues. OBJECTIVE: We aimed to develop an analysis platform that directly, rapidly, and automatically tracks sarcomeres in beating cardiomyocytes. The platform should assess sarcomere content, contraction and relaxation parameters, and beat rate. METHODS AND RESULTS: We developed SarcTrack, a MatLab software that monitors fluorescently tagged sarcomeres in hiPSC-CMs. The algorithm determines sarcomere content, sarcomere length, and returns rates of sarcomere contraction and relaxation. By rapid measurement of hundreds of sarcomeres in each hiPSC-CM, SarcTrack provides large data sets for robust statistical analyses of multiple contractile parameters. We validated SarcTrack by analyzing drug-treated hiPSC-CMs, confirming the contractility effects of compounds that directly activate (CK-1827452) or inhibit (MYK-461) myosin molecules or indirectly alter contractility (verapamil and propranolol). SarcTrack analysis of hiPSC-CMs carrying a heterozygous truncation variant in the myosin-binding protein C ( MYBPC3) gene, which causes hypertrophic cardiomyopathy, recapitulated seminal disease phenotypes including cardiac hypercontractility and diminished relaxation, abnormalities that normalized with MYK-461 treatment. CONCLUSIONS: SarcTrack provides a direct and efficient method to quantitatively assess sarcomere function. By improving existing contractility analysis methods and overcoming technical challenges associated with functional evaluation of hiPSC-CMs, SarcTrack enhances translational prospects for sarcomere-regulating therapeutics and accelerates interrogation of human cardiac genetic variants.

[IVH Prevention for ELBW Preterm Babies in Two Different Perinatal Centers]. / IVH-Prävention bei ELBW-Frühgeborenen in zwei Perinatalzentren.

BACKGROUND: In a project to carefully observe and minimize risk factors of intraventricular hemorrhages (IVH) in preterm infants, the incidence decreased markedly at the perinatal Center in Ulm, Germany. By comparing its data with the perinatal center in Leipzig, Germany, we sought to identify what improvements could still be made. METHODS: A retrospective survey was performed, including 189 infants from Leipzig and 89 from Ulm, all of whom weighed less than 1000 grams. A comparison between both perinatal centers was made. RESULTS: IVH was more frequently detected in Leipzig (28.4%) than in Ulm (14.6%, p=0.011), yet only the incidence of mild IVH (grade 1-2) was affected since the incidence of severe IVH did not differ between the 2 centers (p=0.59, Leipzig 6.1%, Ulm 4.5%). Furthermore, several potentially avoidable risk factors of IVH were differentially distributed between the 2 centers. For example, postnatal hypocapnia and postnatal hypothermia occurred with higher frequency in Leipzig than in Ulm. Conversely, rapid postnatal application of surfactant was the rule in Leipzig but not in Ulm. Furthermore, sodium bicarbonate application occurred more frequently in Ulm. CONCLUSION: Both centers avoided certain risk factors for IVH with varying success. These results allow both centers to specifically target the risk factors that occurred with greater frequency to further reduce the incidence of IVH.