Extremophiles in a changing world.

Extremophiles and their products have been a major focus of research interest for over 40 years. Through this period, studies of these organisms have contributed hugely to many aspects of the fundamental and applied sciences, and to wider and more philosophical issues such as the origins of life and astrobiology. Our understanding of the cellular adaptations to extreme conditions (such as acid, temperature, pressure and more), of the mechanisms underpinning the stability of macromolecules, and of the subtleties, complexities and limits of fundamental biochemical processes has been informed by research on extremophiles. Extremophiles have also contributed numerous products and processes to the many fields of biotechnology, from diagnostics to bioremediation. Yet, after 40 years of dedicated research, there remains much to be discovered in this field. Fortunately, extremophiles remain an active and vibrant area of research. In the third decade of the twenty-first century, with decreasing global resources and a steadily increasing human population, the world's attention has turned with increasing urgency to issues of sustainability. These global concerns were encapsulated and formalized by the United Nations with the adoption of the 2030 Agenda for Sustainable Development and the presentation of the seventeen Sustainable Development Goals (SDGs) in 2015. In the run-up to 2030, we consider the contributions that extremophiles have made, and will in the future make, to the SDGs.

Does left atrial epicardial conduction time reflect atrial fibrosis and the risk of atrial fibrillation recurrence after thoracoscopic ablation? Post hoc analysis of the AFACT trial.

OBJECTIVES: To determine the association between left atrial epicardial conduction time (LAECT), fibrosis and atrial fibrillation (AF) recurrence after thoracoscopic surgical ablation of persistent AF. SETTING: Single tertiary care centre in the Netherlands. PARTICIPANTS: Patients with persistent AF from the randomised Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT)-trial were included. Patients eligible for thoracoscopic AF ablation were included, full inclusion and exclusion criteria were previously published. All patients underwent thoracoscopic ablation, encompassing pulmonary vein isolation with an additional roof and trigone lesion. In patients with conduction block across the roof and trigone lesion, LAECT was measured. LAECT was defined as the time to local activation at one side of the roofline on pacing from the opposite side. Collagen fibre density was quantified from left atrial appendage histology. OUTCOME MEASURES: Primary outcome: AF recurrence during 2 years of follow-up. RESULTS: 121 patients were included, of whom 35(29%) were women, age was 60.4±7.8 and 51% (62) had at least one AF recurrence during 2 years of follow-up. LAECT was longer in patients with versus without AF recurrence (182±43 ms vs 147±29 ms, p<0.001). LAECT was longer in older patients, in patients with a higher body mass index (BMI) and in patients using class IC antiarrhythmic drugs. LAECT was shorter in patients with higher collagen fibre density. A previously failed catheter ablation, LAECT and BMI were independently associated with AF recurrence. CONCLUSION: LAECT is correlated with collagen fibre density and BMI and is independently associated with AF recurrence in patients with persistent AF. In these patients, LAECT appears to reflect substrate characteristics beyond clinical AF type and left atrial volume. TRIAL REGISTRATION NUMBER: NCT01091389.

ECCO Position on Harmonisation of Crohn's Disease Mucosal Histopathology.

In inflammatory bowel disease [IBD], mucosal healing is a major therapeutic target and a reliable predictor of clinical course. However, endoscopic mucosal healing is not synonymous with histological healing, and the additional benefits of including histological remission as a target are unclear. In Crohn´s disease [CD], there are few studies highlighting the value of histological remission as a therapeutic target. Histological activity can persist in CD patients who are in endoscopic remission, and the absence of histological activity may be associated with lower relapse rates. Therefore, standardisation of procedures to evaluate CD histological activity is desirable. Topics that would benefit from standardisation and harmonisation include biopsy procedures, biopsy processing techniques, the content of histological scores, and the definitions of histological remission, histological response, and histological activity. In line with these needs, the European Crohn's and Colitis Organisation [ECCO] assembled a consensus group with the objective of developing position statements on CD histology based on published evidence and expert consensus. There was agreement that definitions of histological remission should include absence of erosion, ulceration, and mucosal neutrophils; that the absence of neutrophilic inflammation is an appropriate histological target in CD; that CD histological scores, such as the Global Histological Disease Activity Score, lack formal validation; and that histological scoring systems for ulcerative colitis, including the Geboes Score, Robarts Histopathology Index, and Nancy Histological Index, can be used for scoring intestinal biopsies in CD patients.

Physical activity, dietary intake and quality of life during COVID-19 lockdown in patients awaiting transcatheter aortic valve implantation.

BACKGROUND: The COVID-19 pandemic has led to a national lockdown in the Netherlands, which also affected transcatheter aortic valve implantation (TAVI) patients. The objective of the study was to describe physical activity, dietary intake and quality of life (QoL) in patients on the waiting list for TAVI pre-lockdown and during lockdown. METHODS: Consecutive patients awaiting TAVI at the Amsterdam University Medical Centers, the Netherlands were included. Measurements were self-reported effect of lockdown, physical activity, dietary intake and QoL. RESULTS: In total, 58 patients (median age 80, interquartile range (IQR) 76-84, 45% female) were observed pre-lockdown and 16 patients (median age 78, IQR 76-82, 25% female) during lockdown. Ten of the 16 patients during lockdown reported a decline in physical activity. However, we observed a median number of 5861 steps a day (IQR 4579-7074) pre-lockdown and 8404 steps a day (IQR 7653-10,829) during lockdown. Median daily protein intake was 69 g (IQR 59-82) pre-lockdown and 90 g (IQR 68-107) during lockdown. Self-rated health on a visual analogue scale was 63 points (IQR 51-74) pre-lockdown and 73 points (IQR 65-86) during lockdown. CONCLUSIONS: More than half of the patients during lockdown reported less physical activity, while we observed a higher number of steps a day, a similar dietary intake and a higher QoL. Therefore, patients on the TAVI waiting list appeared to be able to cope with the lockdown measures.

Nerve palsy, dislocation and revision rate among the approaches for total hip arthroplasty: a Bayesian network meta-analysis.

BACKGROUND: Total hip arthroplasty (THA) is one of the most performed intervention in orthopaedics surgery. Currently, there is no unanimous approval concerning the best approach for THA in terms of nerve palsies, dislocations and further revisions. Hence, a Bayesian network meta-analysis was conducted. METHODS: The present study was conducted according to the PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of healthcare interventions. The literature search was performed in September 2019. The NMA was performed through the STATA Software/MP routine for Bayesian hierarchical random-effects model analysis. RESULTS: Data from 10,675 THA were collected. The mean follow-up was 10 months. The anterior approach reported the lowest risk to incur a post-operative dislocation (overall inconsistency P = 0.99). The posterolateral approach reported the lowest risk to incur a nerve palsy (overall inconsistency P = 0.77). The funnel plot revealed a low risk of publication bias. The lateral approach was found to have the lowest risk of resulting in a revision surgery (overall inconsistency P = 0.90). CONCLUSION: According to our network comparisons, the posterolateral approach for THA represent the favourable exposure with regards to nerve palsy, further dislocations and revision surgeries.

Association of 1-deoxy-sphingolipids with steatosis but not steatohepatitis nor fibrosis in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most important cause of chronic liver disease in the western world. Steatosis can be accompanied by inflammation and cell damage (non-alcoholic steatohepatitis, NASH), and even liver fibrosis. Sphingolipids are a heterogeneous class of lipids and essential components of the plasma membrane and plasma lipoproteins. The atypical class of deoxy-sphingolipids has been implicated in the metabolic syndrome and type 2 diabetes. AIM: To determine if circulating (deoxy)sphingolipids are associated with NAFLD and its different entities, steatosis, inflammatory changes (inflammation and ballooning) and fibrosis. METHODS: Sphingolipids were analysed by LC-MS after hydrolysing the N-acyl and O-linked headgroups in plasma of obese adults who underwent a liver biopsy in suspicion of NAFLD. RESULTS: Two-hundred and eighty-eight patients were included. There was no association between typical sphingolipids and NAFLD and its different entities. There was a significant association between the presence of steatosis and the concentrations of deoxy-sphinganine [exp(B) 11.163 with CI (3.432, 36.306) and p < 0.001] and deoxy-sphingosine [exp(B) 8.486 with CI (3.437, 20.949) and p < 0.001]. There was no association between these deoxy-sphingolipids and activity of the steatohepatitis, nor was there any association with fibrosis. Differences in deoxy-sphingolipids also correlated independently with the presence of the metabolic syndrome, but not diabetes. CONCLUSION: Deoxy-sphingolipids are elevated in patients with steatosis compared to those without fatty liver, but not different between the different NAFLD subtypes, suggesting that deoxy-sphingolipid bases might be involved in steatogenesis, but not in the further progression of NAFLD to NASH nor in fibrogenesis.

Guidelines for an optimal management of a malignant colorectal polyp. What is essential in a pathology report ?

Colorectal cancer (CRC) has become the most common malignancy in our country. Routine screening colonoscopy is on the rise. With the recent advances in endoscopic treatment, many T1 colorectal carcinomas are now found and their percentage amenable to endoscopic resection has increased. Endoscopists and pathologists dealing with the steadily increasing number of excised colorectal polyps have to collaborate closely to optimize patient care. Therapeutic management of patients after endoscopic resection is based on precise histological criteria that determine the risk of metastasis and the need for complementary surgery. This paper summarizes the procedures for the macroscopic management of endoscopic excisions and presents the identified risk factors which should be included in a standardized pathology report.

Patient blood management in the cardiac surgical setting: An updated overview.

In cardiac surgical patients it is a complex challenge to find the ideal balance between anticoagulation and hemostasis. Preoperative anemia and perioperative higher transfusion rates are related to increased morbidity and mortality. Patient blood management (PBM) is an evidence based patient specific individualized protocol used in the perioperative setting in order to reduce perioperative bleeding and transfusion rates and to improve patient outcomes. The three pillars of PBM in cardiac surgery consist of optimization of preoperative erythropoiesis and hemostasis, minimizing blood loss, and improving patient specific physiological reserves. This narrative review focuses on the challenges with special emphasis on PBM in the preoperative phase and intraoperative transfusion management and hemostasis in cardiac surgery patients. It is a "must" that PBM is a collaborative effort between anesthesiologists, surgeons, perfusionists, intensivists and transfusion laboratory teams. This review represents an up to date overview over "PBM in cardiac surgery patients".

Polymorphic assembly of virus-capsid proteins around DNA and the cellular uptake of the resulting particles.

Virus-like particles (VLPs), i.e. molecular assemblies that resemble the geometry and organization of viruses, are promising platforms for therapeutics and imaging. Understanding the assembly and cellular uptake pathways of VLPs can contribute to the development of new antiviral drugs and new virus-based materials for the delivery of drugs or nucleic acid-based therapies. Here we report the assembly of capsid proteins of the cowpea chlorotic mottle virus (CCMV) around DNA into defined structures at neutral pH. Depending on the type of DNA used, we are able to create spherical structures of various diameters and rods of various lengths. In order to determine the shape dependency, the cellular uptake routes and intracellular positioning of these formed polymorphic VLPs in RAW264.7, HeLa and HEK 293 cells are evaluated using flow cytometry analysis with specific chemical inhibitors for different uptake routes. We observed particular uptake routes for the various CCMV-based nanostructures, but the experiments point to clathrin-mediated endocytosis as the major route for cell entry for the studied VLPs. Confocal microscopy reveals that the formed VLPs enter the cells, with clear colocalization in the endosomes. The obtained results provide insight in the cargo dependent VLP morphology and increase the understanding of shape dependent uptake into cells, which is relevant in the design of new virus-based structures with applications in drug and gene delivery.

Transcatheter aortic valve replacement alters ascending aortic blood flow and wall shear stress patterns: A 4D flow MRI comparison with age-matched, elderly controls.

BACKGROUND: With the implementation of transcatheter aortic valve replacement (TAVR) in lower-risk patients, evaluation of blood flow characteristics and the effect of TAVR on aortic dilatation becomes of considerable interest. We employed 4D flow MRI in the ascending aorta of patients after TAVR to assess wall shear stress (WSS) and compare blood flow patterns with surgical aortic valve replacement (SAVR) and age- and gender-matched controls. METHODS: Fourteen post-TAVR patients and ten age- and gender-matched controls underwent kt-PCA accelerated 4D flow MRI of the thoracic aorta at 3.0 Tesla. Velocity and wall shear stress was compared between the two groups. In addition, aortic flow eccentricity and displacement was assessed and compared between TAVR patients, controls and 14 SAVR patients recruited as part of an earlier study. RESULTS: Compared to controls, abnormally elevated WSS was present in 30±10% of the ascending aortic wall in TAVR patients. Increased WSS was present along the posterior mid-ascending aorta and the anterior distal-ascending aorta in all TAVR patients. TAVR results in eccentric and displaced flow in the mid- and distal-ascending aorta, whereas blood flow displacement in SAVR patients occurs only in the distal-ascending aorta. CONCLUSION: This study shows that TAVR results in increased blood flow velocity and WSS in the ascending aorta compared to age- and gender-matched elderly controls. This finding warrants longitudinal assessment of aortic dilatation after TAVR in the era of potential TAVR in lower-risk patients. Additionally, TAVR results in altered blood flow eccentricity and displacement in the mid- and distal-ascending aorta, whereas SAVR only results in altered blood flow eccentricity and displacement in the distal-ascending aorta. KEY POINTS: • TAVR results in increased blood flow velocity and WSS in the ascending aorta. • Longitudinal assessment of aortic dilatation after TAVR is warranted in the era of potential TAVR in lower-risk patients. • Both TAVR and SAVR result in altered blood flow patterns in the ascending aorta when compared to age-matched controls.

[Total hip replacement in avascular femoral head necrosis]. / Endoprothetik bei aseptischer Femurkopfnekrose.

BACKGROUND: Avascular necrosis of the femoral head is a progressive perfusion disorder of the hip joint. Progress in avascular necrosis causes structural damage to the affected joint, often requiring total hip replacement. AIM: This article is intended to give the reader an overview of the current literature on total hip replacement of patients with an avascular necrosis of the femoral head. RESULTS: Before 1990, patients with avascular necrosis of the femoral head had significantly higher revision rates after total hip replacement. Recent studies, however, showed no significant differences in clinical outcomes after total hip replacement in femoral head necrosis and primary osteoarthritis. Despite the young age of the patients, good long-term clinical results can be expected even in patients with an avascular necrosis of the femoral head after total hip replacement.

Trends in patient characteristics and clinical outcome over 8 years of transcatheter aortic valve implantation.

AIM: In the evolving field of transcatheter aortic valve implantations (TAVI) we aimed to gain insight into trends in patient and procedural characteristics as well as clinical outcome over an 8­year period in a real-world TAVI population. METHODS: We performed a single-centre retrospective analysis of 1,011 consecutive patients in a prospectively acquired database. We divided the cohort into tertiles of 337 patients; first interval: January 2009-March 2013, second interval: March 2013-March 2015, third interval: March 2015-October 2016. RESULTS: Over time, a clear shift in patient selection was noticeable towards lower surgical risks including Society of Thoracic Surgeons predicted risk of mortality score and comorbidity. The frequency of transfemoral TAVI increased (from 66.5 to 77.4%, p = 0.0015). Device success improved (from 62.0 to 91.5%, p < 0.0001) as did the frequency of symptomatic relief (≥1 New York Heart Association class difference) (from 73.8 to 87.1%, p = 0.00025). Complication rates decreased, including in-hospital stroke (from 5.0 to 2.1%, p = 0.033) and pacemaker implantations (from 10.1 to 5.9%, p = 0.033). Thirty-day mortality decreased (from 11.0 to 2.4%, p < 0.0001); after adjustment for patient characteristics, a mortality-risk reduction of 72% was observed (adjusted hazard ratio [HR]: 0.28, 95% confidence interval [CI]: 0.13-0.62). One-year mortality rates decreased (from 23.4 to 11.4%), but this was no longer significant after a landmark point was set at 30 days (mortality from 31 days until 1 year) (adjusted HR: 0.69, 95% CI: 0.41-1.16, p = 0.16). CONCLUSION: A clear shift towards a lower-risk TAVI population and improved clinical outcome was observed over an 8­year period. Survival after TAVI improved impressively, mainly as a consequence of decreased 30-day mortality.

The Belgian Association for Study of the Liver Guidance Document on the Management of Adult and Paediatric Non-Alcoholic Fatty Liver Disease.

Non-Alcoholic Fatty Liver Disease (NAFLD) is highly prevalent and associated with considerable liver-related and non-liverrelated morbidity and mortality. There is, however, a lot of uncertainty on how to handle NAFLD in clinical practice. The current guidance document, compiled under the aegis of the Belgian Association for the Study of the Liver by a panel of experts in NAFLD, from a broad range of different specialties, covers many questions encountered in daily clinical practice regarding diagnosis, screening, therapy and follow-up in adult and paediatric patients. Guidance statements in this document are based on the available evidence whenever possible. In case of absence of evidence or inconsistency of the data, guidance statements were formulated based on consensus of the expert panel. This guidance document is intended as a help for clinicians (general practitioners and all involved specialties) to implement the most recent evidence and insights in the field of NAFLD within a Belgian perspective.

Screening for therapeutic trials and treatment indication in clinical practice: MACK-3, a new blood test for the diagnosis of fibrotic NASH.

BACKGROUND: The composite histological endpoint comprising nonalcoholic steatohepatitis (NASH) and NAFLD activity score ≥4 and advanced fibrosis (F ≥ 2) ("fibrotic NASH") is becoming an important diagnostic target in NAFLD: it is currently used to select patients for inclusion in phase III therapeutic trials and will ultimately be used to indicate treatment in clinical practice once the new drugs are approved. AIM: To develop a new blood test specifically dedicated for this new diagnostic target of interest. METHODS: Eight Hundred and forty-six biopsy-proven NAFLD patients from three centres (Angers, Nice, Antwerp) were randomised into derivation and validation sets. RESULTS: The blood fibrosis tests BARD, NFS and FIB4 had poor accuracy for fibrotic NASH with respective AUROC: 0.566 ± 0.023, 0.654 ± 0.023, 0.732 ± 0.021. In the derivation set, fibrotic NASH was independently predicted by AST, HOMA and CK18; all three were combined in the new blood test MACK-3 (hoMa, Ast, CK18) for which 90% sensitivity and 95% specificity cut-offs were calculated. In the validation set, MACK-3 had a significantly higher AUROC (0.847 ± 0.030, P ≤ 0.002) than blood fibrosis tests. Using liver biopsy in the grey zone between the two cut-offs (36.0% of the patients), MACK-3 provided excellent accuracy for the diagnosis of fibrotic NASH with 93.3% well-classified patients, sensitivity: 90.0%, specificity: 94.2%, positive predictive value: 81.8% and negative predictive value: 97.0%. CONCLUSION: The new blood test MACK-3 accurately diagnoses fibrotic NASH. This new test will facilitate patient screening and inclusion in NAFLD therapeutic trials and will enable the identification of patients who will benefit from the treatments once approved.

Increased xylose affinity of Hxt2 through gene shuffling of hexose transporters in Saccharomyces cerevisiae.

AIMS: Optimizing D-xylose transport in Saccharomyces cerevisiae is essential for efficient bioethanol production from cellulosic materials. We have used a gene shuffling approach of hexose (Hxt) transporters in order to increase the affinity for D-xylose. METHODS AND RESULTS: Various libraries were transformed to a hexose transporter deletion strain, and shuffled genes were selected via growth on low concentrations of D-xylose. This screening yielded two homologous fusion proteins (fusions 9,4 and 9,6), both consisting of the major central part of Hxt2 and various smaller parts of other Hxt proteins. Both chimeric proteins showed the same increase in D-xylose affinity (8·1 ± 3·0 mmol l-1 ) compared with Hxt2 (23·7 ± 2·1 mmol l-1 ). The increased D-xylose affinity could be related to the C terminus, more specifically to a cysteine to proline mutation at position 505 in Hxt2. CONCLUSIONS: The Hxt2C505P mutation increased the affinity for D-xylose for Hxt2, thus providing a way to increase D-xylose transport flux at low D-xylose concentration. SIGNIFICANCE AND IMPACT OF THE STUDY: The gene shuffling protocol using the highly homologues hexose transporters family provides a powerful tool to enhance the D-xylose affinity of Hxt transporters in S. cerevisiae, thus providing a means to increase the D-xylose uptake flux at low D-xylose concentrations.

[Current overview of cartilage regeneration procedures]. / Aktuelle Übersicht knorpelregenerativer Verfahren.

BACKGROUND: Cartilage is an avascular, alymphatic and non-innervated tissue with limited intrinsic repair potential. The high prevalence of cartilage defects and their tremendous clinical importance are a challenge for all treating physicians. AIM: This article provides the reader with an overview about current cartilage treatment options and their clinical outcome. METHODS: Microfracture is still considered the gold standard in the treatment of small cartilage lesions. Small osteochondral defects can be effectively treated with the autologous osteochondral transplantation system. Larger cartilage defects are successfully treated by autologous membrane-induced chondrogenesis (AMIC) or by membrane-assisted autologous chondrocyte implantation (MACI). CONCLUSION: Despite limitations of current cartilage repair strategies, such procedures can result in short- and mid-term clinical improvement of the patients. Further developments and clinical studies are necessary to improve the long-term outcome following cartilage repair.

Estimation of the future remnant liver function is a better tool to predict post-hepatectomy liver failure than platelet-based liver scores.

INTRODUCTION: Recently, there has been increasing interest in the preoperative prediction and prevention of post-hepatectomy liver failure (PHLF). This is a particular concern in colorectal liver metastases (CRLM), when surgery follows potentially hepatotoxic chemotherapy. Platelet-based liver scores (PBLS) such as APRI and FIB-4 are predictive of chemotherapy-associated liver injury (CALI) and PHLF. Estimation of the future liver remnant function (eFLRF) by combining 99mTc-Mebrofenin Hepatobiliary Scintigraphy (HBSBSA) with future liver remnant volume ratio (FLRV%), is predictive of PHLF and related mortality. We hypothesized that a HBSBSA based formula was a better predictor for PHLF than PBLS in chemotherapy-pretreated CRLM. METHODS: Between 2012 and 2016, 140 patients underwent liver resection for CRLM following systemic therapy. HBSBSA, FLRV%, eFLRF and PBLS were calculated and compared for their value in predicting PHLF. RESULTS: eFLRF and FLRV% had a better predictive value for PHLF than HBSBSA alone and APRI and FIB-4 (AUC = 0.800, 0.843 versus 0.652, 0.635 and 0.658 respectively). In a subgroup analysis (Oxaliplatin all, Oxaliplatin ≥ 6 cycles, Irinotecan all and Irinotecan ≥ 6 cycles), eFLRF was the only factor predictive for PHLF in all subgroups (all: p ≤ 0.05). Prediction of HBSBSA for chemotherapy associated steato-hepatitis (CASH) reached almost significance (p = 0.06). FIB-4 was predictive for sinusoidal obstruction syndrome (SOS) (p = 0.011). Only weak correlation was found between HBSBSA and PBLS. CONCLUSION: eFLRF is a better predictor of PHLF than PBLS or HBSBSA alone. PBLS seem to measure other aspects of liver function or damage than HBSBSA.