Semi-automatic quantification of mosaic perfusion of lung parenchyma and its correlation with haemodynamic parameters in patients with chronic thromboembolic pulmonary hypertension

AIM

To investigate the feasibility of semiautomatic quantification of mosaic perfusion and the associations between mosaic perfusion on computed tomography (CT; the ratio of hypoperfused parenchyma to the whole lung volume) and haemodynamic parameters through linear regression analysis.

MATERIALS AND METHODS

Fifty-eight consecutive patients (mean age 66 years, 28 females) diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH) in General University Hospital, Prague, in 2021 were evaluated retrospectively and underwent both right heart catheterisation and CT pulmonary angiography. The parameters derived from the CT examinations were correlated with the recorded haemodynamic parameters.

RESULTS

A method was developed for semiautomatic detection of hypoperfused tissue from CT using widely available software and a statistically significant correlation was found between the proportion of hypoperfused parenchyma and the mean pulmonary artery pressure (mPAP; R2 0.22; p<0.01) and pulmonary vascular resistance (PVR; R2 0.09; p<0.05).

CONCLUSIONS

The developed method facilitates the quantification of mosaic perfusion, which is associated with important haemodynamic parameters (mPAP and PVR) in patients with CTEPH.

EuCd_{2}As_{2}: A Magnetic Semiconductor

EuCd_{2}As_{2} is now widely accepted as a topological semimetal in which a Weyl phase is induced by an external magnetic field. We challenge this view through firm experimental evidence using a combination of electronic transport, optical spectroscopy, and excited-state photoemission spectroscopy. We show that the EuCd_{2}As_{2} is in fact a semiconductor with a gap of 0.77 eV. We show that the externally applied magnetic field has a profound impact on the electronic band structure of this system. This is manifested by a huge decrease of the observed band gap, as large as 125 meV at 2 T, and, consequently, by a giant redshift of the interband absorption edge. However, the semiconductor nature of the material remains preserved. EuCd_{2}As_{2} is therefore a magnetic semiconductor rather than a Dirac or Weyl semimetal, as suggested by ab initio computations carried out within the local spin-density approximation.

Exploring LoRaWAN Traffic: In-Depth Analysis of IoT Network Communications

In the past decade, Long-Range Wire-Area Network (LoRaWAN) has emerged as one of the most widely adopted Low Power Wide Area Network (LPWAN) standards. Significant efforts have been devoted to optimizing the operation of this network. However, research in this domain heavily relies on simulations and demands high-quality real-world traffic data. To address this need, we monitored and analyzed LoRaWAN traffic in four European cities, making the obtained data and post-processing scripts publicly available. For monitoring purposes, we developed an open-source sniffer capable of capturing all LoRaWAN communication within the EU868 band. Our analysis discovered significant issues in current LoRaWAN deployments, including violations of fundamental security principles, such as the use of default and exposed encryption keys, potential breaches of spectrum regulations including duty cycle violations, SyncWord issues, and misaligned Class-B beacons. This misalignment can render Class-B unusable, as the beacons cannot be validated. Furthermore, we enhanced Wireshark's LoRaWAN protocol dissector to accurately decode recorded traffic. Additionally, we proposed the passive reception of Class-B beacons as an alternative timebase source for devices operating within LoRaWAN coverage under the assumption that the issue of misaligned beacons can be addressed or mitigated in the future. The identified issues and the published dataset can serve as valuable resources for researchers simulating real-world traffic and for the LoRaWAN Alliance to enhance the standard to facilitate more reliable Class-B communication.

On the Role of Training Data for SVM-Based Microwave Brain Stroke Detection and Classification

The aim of this work was to test microwave brain stroke detection and classification using support vector machines (SVMs). We tested how the nature and variability of training data and system parameters impact the achieved classification accuracy. Using experimentally verified numerical models, a large database of synthetic training and test data was created. The models consist of an antenna array surrounding reconfigurable geometrically and dielectrically realistic human head phantoms with virtually inserted strokes of arbitrary size, and different dielectric parameters in different positions. The generated synthetic data sets were used to test four different hypotheses, regarding the appropriate parameters of the training dataset, the appropriate frequency range and the number of frequency points, as well as the level of subject variability to reach the highest SVM classification accuracy. The results indicate that the SVM algorithm is able to detect the presence of the stroke and classify it (i.e., ischemic or hemorrhagic) even when trained with single-frequency data. Moreover, it is shown that data of subjects with smaller strokes appear to be the most suitable for training accurate SVM predictors with high generalization capabilities. Finally, the datasets created for this study are made available to the community for testing and developing their own algorithms.

UHPLC-Orbitrap study of the first phase tacrine in vitro metabolites and related Alzheimer's drug candidates using human liver microsomes

Tacrine was the first drug used in the therapy of Alzheimer's disease (AD) and is one of the leading structures frequently pursued in the drug discovery of novel candidates for tackling AD. However, because tacrine has been withdrawn from the market due to its hepatotoxicity, ascribed to specific metabolites, concerns are high about the toxicity profile of newly developed compounds related to tacrine. From the point of view of drug safety, the formation of metabolites must be uncovered and analyzed. Bearing in mind that the main culprit of tacrine hepatotoxicity is its biotransformation to hydroxylated metabolites, human liver microsomes were used as a biotransformation model. Our study aims to clarify phase I metabolites of three potentially non-toxic tacrine derivatives (7-methoxytacrine, 6-chlorotacrine, 7-phenoxytacrine) and to semi-quantitatively determine the relative amount of individual metabolites as potential culprits of tacrine-based hepatotoxicity. For this purpose, a new selective UHPLC-Orbitrap method has been developed. Applying UHPLC-Orbitrap method, two as yet unpublished tacrine and 7-methoxytacrine monohydroxylated metabolites have been found and completely characterized, and the separation of ten dihydroxylated tacrine and 7-methoxytacrine metabolites was achieved for the first time. Moreover, the structures of several new metabolites of 7-phenoxytacrine and 6-chlorotacrine have been identified. In addition, the relative amount of these newly observed metabolites was determined. Based on the results and known facts about the toxicity of tacrine metabolites published so far, it appears that 7-phenoxytacrine and 6-chlorotacrine could be substantially less hepatotoxic compared to tacrine, and could potentially pave the way for metabolically safe molecules applicable in AD therapy.

Strategic management to optimize response to cardiac resynchronization therapy registry

Background

Cardiac resynchronization therapy (CRT) is guideline-recommended for the treatment of symptomatic heart failure (HF) in patients (pts) with reduced LVEF and prolonged QRS. Clinical trials report Clinical Composite Score (CCS) response rates from 60 to 75%. However, patients with common comorbidities, such as atrial fibrillation, are often under-represented in clinical trials. The Strategic MAnagement to optimize response to cardiac Resynchronization Therapy (SMART) Registry (NCT03075215) was designed to examine outcomes in CRT patients in the real world.

Methods

The SMART Registry was a global, multicenter, prospective, clinical registry that enrolled subjects undergoing a de novo CRT-D implant or upgrade from pacemaker to CRT-D using a quadripolar LV lead. CCS was assessed at 12 months post-implant.

Results

For study design and CCS outcomes see Figure 1. CCS at 12 months showed that 58.8% of pts improved and 20.1% stabilized. Of the 21.1% of pts that worsened, 8.4% were due to death, 7.8% non-fatal heart failure event, and 5% worsening of NYHA or patient global assessment. Notably, this registry had a high prevalence of pts with NYHA I/II (51%), Non-LBBB (50%), AF (37%), diabetes (35%), and bradycardia (31%) at baseline. Age (&gt;65), diabetes, ischemia, non-LBBB, atrial fibrillation (AF) and renal dysfunction correlated with worsened CCS outcomes. NYHA III/IV patients had significantly higher HF hospitalization (HFH) rates than NYHA I/II (P-value &lt;0.001) (Figure 2a) and patients with AF had higher HFH rates than those without (P-value &lt;0.001) (Figure 2b). Similar effects of NYHA score and AF were seen on mortality. The use of ACE/ARB, or ARNI, and MRA correlated with better outcomes, whereas diuretics and anticoagulants correlated with poorer outcomes.

Conclusions

In this large registry, clinical outcomes across important sub-populations are in line with expectations, with older age, ischemia, renal dysfunction, AF, non-LBBB, and diabetes associated with a lower likelihood of response to CRT. By including these patients, this study provides a clearer picture of the effectiveness of CRT in the real world. Future studies should examine optimization approaches to facilitate CRT effectiveness in these under studied patient populations.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This registry was funded by Boston Scientific (BSC)

P02.07.B Patient-derived glioblastoma organoids: Elucidating the mechanisms of glioblastoma therapeutic resistance in the context of tumor microenvironment

Background

Intratumoral heterogeneity plays an important role in glioblastoma (GB) resistance to standard therapy consisting of irradiation and chemotherapy with temozolomide (TMZ). However, classical in vitro GB models fail to represent the complex cellular composition of tumors in vivo, which hinders relevant examination of GB therapeutic response. To overcome these limitations, we studied the effects of irradiation and TMZ in a novel patient-derived organoid model.

Material and Methods

We established a patient-derived GB organoid model by a protocol recently published by Jacob et al. Original tumor tissue and tissue-derived organoids were compared by immunofluorescence staining of selected cell type markers and qPCR analysis of expression levels of a panel of selected target genes, including 15 genes defining GB subtypes. To analyze GB therapeutic response, organoids from 11 patients were exposed to a single dose of irradiation (10 Gy), one-week treatment with TMZ (50 µM) or their combination. The effects of therapy were assessed by viability and invasion assays. Expression levels of a number of genes related to GB subtypes, epithelial-mesenchymal transition, stemness, DNA damage responses, cell cycle, cytokines, and cell markers of the tumor microenvironment (TME) were compared between treated organoids and untreated controls. In addition, the heterogeneity of the TME and its responses to treatment were investigated by spatially resolved transcriptomics with in situ sequencing (ISS) methodology.

Results

Organoids recapitulate inter-patient variability and reflect the cellular composition and gene expression levels of the tumor tissue from which they were derived. GB stem cells and differentiated cancer cells are present in organoids along with various cells of the TME, e.g., macrophages and microglia, lymphocytes, and endothelial cells. Irradiation and TMZ showed no significant effects on organoid viability and invasion. However, some target genes were differentially expressed in the treated organoids, such as E3 ubiquitin-protein ligase MDM2 and cyclin-dependent kinase inhibitor 1A (CDKN1A). To our knowledge, we are the first to apply spatially resolved transcriptomics (ISS) to formalin-fixed, paraffin-embedded sections of (un)treated GB organoids. Our results elucidate the role of the TME in GB therapeutic response and shed light on potential mechanism underlying GB therapy resistance.

Conclusion

Patient-derived GB organoids recapitulate the key characteristics and complex composition of patient’s tumor tissue, providing a valuable platform for studies of GB therapeutic response and resistance.

P06.07.A Natural killer cells lyse glioblastoma stem cells and increase their sensitivity to chemotherapy

Background

Glioblastoma is the most common and lethal brain tumor in the adult population and immunotherapy is playing an increasingly central role in the treatment of many cancers. Nevertheless, the search for effective immunotherapeutic approaches for glioblastoma patients continues. In this study, we aimed to explore the therapeutic potential of allogeneic highly activated super-charged natural killer (NK) cells in glioblastoma.

Material and Methods

Chromium release- and calcein release-based cytotoxicity assays, ELISA, ELISPOT, and multiplex cytokine assays were used to determine NK cell cytotoxicity against glioblastoma stem cells (GSCs) and secretion of cytokines. Cell surface marker expression using flow cytometry and cell growth in vitro and in vivo were measured to determine GSC phenotype. NK cell killing and penetration in 3D were measured using confocal microscopy of GSC tumorospheres.

Results

Super-charged NK cells efficiently lysed patient-derived GSCs in 2D and 3D models potentially reversing the immunosuppression observed in patients. NK-cells secreted IFN-γ, upregulated GSC surface expression of CD54 and MHC class I and increased sensitivity of GSCs to chemotherapeutic drugs. Co-localization of NK cells with GBM cells in perivascular niches in glioblastoma tissues and their direct contact with GSCs in tumorospheres suggests their ability to infiltrate glioblastoma tumors and target GSCs.

Conclusion

Allogeneic super-charged NK cells appear to be a potential therapeutic approach for glioblastoma by selectively killing therapy-resistant cancer stem cell population, increasing their immune-related surface markers and enhancing their sensitivity to chemotherapy. Due to GSC heterogeneity and plasticity personalized immunotherapeutic strategies should be developed to effectively target glioblastomas.

Concussion Management Guidelines Neglect Auditory Symptoms

Tinnitus, noise sensitivity, and hearing difficulties are commonly reported secondary to head injury. These auditory deficits have been shown to negatively impact daily functioning, and yet, often go unnoticed by health care professionals. The purpose of this editorial is to explain why it is essential for clinical practice guidelines that address the management of patients who have experienced a head injury to incorporate assessment and rehabilitation of auditory symptoms.

Report on G4-Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group

BACKGROUND

Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing.

AIMS

To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics.

MATERIALS AND METHODS

G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes.

RESULTS

This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data.

DISCUSSION

Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics.

CONCLUSION

The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application.

Essential role of PET-CT in the management of patients with severe infectious complication CIEDS: multicentre study

Background

With the increasing number of implanted cardiac pacemakers, ICDs and CRTs, the number of serious infectious complications of these procedures increases significantly, especially in the longer term from the primary implantation. The systematic solution is in most cases endovasal extraction of these systems.

Methods

In a multicenter, prospective, randomized, controlled trial evaluating the benefit of CIEDS infection management in 277 patients, a conventional approach using blood cultures, microbiological examinations and TEE versus innovative management of these patients using PET-CT was compared. PET-CT examination is able to differentiate very well the infection of the implant pocket (Figure A) against bacterial endocarditis (Figure B). Thanks to this, it is possible to individualize the management of the patient and to shorten the dates of hospitalization, resp. time to re-implantation of the new system in patients without the presence of bacterial endocarditis.

Results

The results of the multicentre study are summarized in Table 1.

Conclusions

A comprehensive examination of patients with CDRIE using PET-CT significantly shortens hospital stay, time of antibiotic therapy and, as a consequence, leads to a lower incidence of serious complications of extraction procedures.

PET-CT in CDRIE patients

Funding Acknowledgement

Type of funding source: None

AADvac1, an Active Immunotherapy for Alzheimer's Disease and Non Alzheimer Tauopathies: An Overview of Preclinical and Clinical Development

Neurofibrillary tau protein pathology is closely associated with the progression and phenotype of cognitive decline in Alzheimer's disease and other tauopathies, and a high-priority target for disease-modifying therapies. Herein, we provide an overview of the development of AADvac1, an active immunotherapy against tau pathology, and tau epitopes that are potential targets for immunotherapy. The vaccine leads to the production of antibodies that target conformational epitopes in the microtubule-binding region of tau, with the aim to prevent tau aggregation and spreading of pathology, and promote tau clearance. The therapeutic potential of the vaccine was evaluated in transgenic rats and mice expressing truncated, non mutant tau protein, which faithfully replicate of human tau pathology. Treatment with AADvac1 resulted in reduction of neurofibrillary pathology and insoluble tau in their brains, and amelioration of their deleterious phenotype. The vaccine was highly immunogenic in humans, inducing production of IgG antibodies against the tau peptide in 29/30 treated elderly patients with mild-to-moderate Alzheimer's. These antibodies were able to recognise insoluble tau proteins in Alzheimer patients' brains. Treatment with AADvac1 proved to be remarkably safe, with injection site reactions being the only adverse event tied to treatment. AADvac1 is currently being investigated in a phase 2 study in Alzheimer's disease, and a phase 1 study in non-fluent primary progressive aphasia, a neurodegenerative disorder with a high tau pathology component.

Ribotypes in isolates and testing algorithm of C. difficile infections in the studied sample

BACKGROUND

Clostridium (Clostridioides) difficile is the most common pathogen of nosocomial and antibiotic-related diarrhea in health-care facilities. The aim of the analysis was to show the testing algorithm and to identify hypervirulent strains (suspected RT 027).

METHODS

The retrospective analysis of patient samples suspected on CDI was carried out by a two-step algorithm. Biological specimens were analysed by GDH or culture, immunoenzymatic assay on toxins A/B and selected samples also by a real-time PCR.

RESULTS

In 1006 specimen suspected on CDI, 202 specimens were evaluated as positive in the two-step algorithm. Conflicting results (64 C. difficile isolates) were tested in a three-step algorithm by a real-time PCR and revealed 59 toxigenic and non RT 027 ribotypes. Statistically significant dependence among the independent variables, such as: diagnostic parameters and length of hospitalization (p = 0.175) and C. difficile (suspected RT027) ribotypes was not found.

CONCLUSION

The results of PCR ribotyping showed a high prevalence of hypervirulent and toxigenic ribotypes in the studied sample. A resistance to vancomycin was found in one isolate. The PCR method contributed to the rapid laboratory diagnosis and thus treatment of high risk patients or was used as a third step in in the case of unclear results of standard diagnostic methods(Tab. 1, Fig. 4, Ref. 18). Text in PDF www.elis.sk.

P258 Giant coronary arteriovenous fistula with significant left-to-right shunt in symptomatic patient - a multimodal diagnostic approach and successful surgical treatment

Funding Acknowledgements

none

OnBehalf

none

Coronary arteriovenous fistula (CAF) is a rare usually congenital defect that occurs in 0.1-0.2% of patients undergoing coronary angiography. A left-to-right shunt exists in more than 90% cases. In approximately 20% of patients CAF is accompanied with coronary artery aneurysm (CAA).

We describe a case of 65-years-old woman with history of murmur from childhood, who presents with symptoms of slowly worsening dyspnea on exertion and strong pericardial pain. A suspicion for CAF was made from echocardiography and finally confirmed by other diagnostic modalities (coronary angiography and computed tomography with 3D reconstructions). We have diagnosed a complex case of a giant CAA involving left main and a periphery of left circumflex artery, accompanied with CAF terminating in the right atrium, responsible for a significant left-to-right shunt and coronary steal phenomenon.

Patient was successfully treated by surgical ligation of the distal part of CAF in the right atrium. There were no signs of an acute myocardial ischemia on beating heart (ECG, perioperative echocardiography) when CAF was temporary occluded by tourniquet and so definitive surgical ligation of CAF was performed back on cardiopulmonary bypass. The postoperative course was uneventful without complications and the patient was discharged 6 days after surgery.

One year after surgery patient is doing well with no complaints. Control echocardiography showed a regression of left and right ventricle volume overload. Coronary angiography showed normal perfusion in the left coronary artery territory, and no more visible collaterals flow right coronary artery.

Abstract P258 Figure. complex coronary artery aneurysm

Intercontinental collaborative experience with abdominal, retroperitoneal and pelvic schwannomas

Background

Schwannomas are rare tumours that pose a significant management challenge in the abdomen, retroperitoneum and pelvis. No data are available to inform management strategy.

Methods

A collaborative international cohort study, across specialist sarcoma units, was conducted to include adults presenting between 2000 and 2017 with histopathologically confirmed schwannomas within the abdomen, retroperitoneum or pelvis.

Results

Of 485 patients across 12 centres, 38 (7·8 per cent) were discharged without follow-up, 199 (41·0 per cent) underwent early resection and 248 (51·1 per cent) had radiological monitoring. Of these 248 patients, 96 (38·7 per cent) eventually had surgery, giving an overall resection rate of 60·8 per cent (295 of 485). At baseline, median tumour volume was 90·1 (i.q.r. 26·5–262·0) cm3. The estimated growth rate was 10·5 (95 per cent c.i. 9·4 to 11·6) per cent per year, and was consistent in the short term (within 2 years of diagnosis) and long term (beyond 2 years) (ρ = 0·405, P = 0·021). A decision to operate was more common in symptomatic patients (P &lt; 0·001) and for rapidly growing tumours (growth rate more than 20 per cent per year) (P = 0·025). R0/R1 resection was achieved in 91·6 per cent of patients (263 of 287). Kaplan–Meier long-term recurrence rates after R0/R1 resection were 2·3 and 6·7 per cent at 3 and 5 years respectively.

Conclusion

Specific recommendations include: indications for early surgery, prediction of growth from radiological monitoring, promotion of selective submacroscopic resection and cessation of postoperative imaging surveillance.

The ESC ACCA EAPCI EORP acute coronary syndrome ST-elevation myocardial infarction registry

Aims 

The Acute Cardiac Care Association (ACCA)–European Association of Percutaneous Coronary Intervention (EAPCI) Registry on ST-elevation myocardial infarction (STEMI) of the EurObservational programme (EORP) of the European Society of Cardiology (ESC) registry aimed to determine the current state of the use of reperfusion therapy in ESC member and ESC affiliated countries and the adherence to ESC STEMI guidelines in patients with STEMI.

Methods and results 

Between 1 January 2015 and 31 March 2018, a total of 11 462 patients admitted with an initial diagnosis of STEMI according to the 2012 ESC STEMI guidelines were enrolled. Individual patient data were collected across 196 centres and 29 countries. Among the centres, there were 136 percutaneous coronary intervention centres and 91 with cardiac surgery on-site. The majority of centres (129/196) were part of a STEMI network. The main objective of this study was to describe the demographic, clinical, and angiographic characteristics of patients with STEMI. Other objectives include to assess management patterns and in particular the current use of reperfusion therapies and to evaluate how recommendations of most recent STEMI European guidelines regarding reperfusion therapies and adjunctive pharmacological and non-pharmacological treatments are adopted in clinical practice and how their application can impact on patients’ outcomes. Patients will be followed for 1 year after admission.

Conclusion 

The ESC ACCA-EAPCI EORP ACS STEMI registry is an international registry of care and outcomes of patients hospitalized with STEMI. It will provide insights into the contemporary patient profile, management patterns, and 1-year outcome of patients with STEMI.

Social stability influences the association between adrenal responsiveness and hair cortisol concentrations in rhesus macaques

Hair cortisol concentrations are increasingly being used in both humans and nonhuman animals as a biomarker of chronic stress. However, many details regarding how hair cortisol concentrations relate to the dynamic activity and regulation of the HPA axis are still unknown. The current study explores 1) how the regulation of the HPA axis in infancy relates to hair cortisol concentrations (HCC) in infancy 2) whether this relationship persists into adulthood under conditions of social stability, and 3) how social instability impacts these relationships. All subjects were rhesus monkeys housed in large social groups at the California National Primate Research Center, and all had participated in a 25-hr. long BioBehavioral Assessment (BBA) at 3-4 months of age when four plasma samples were taken to assess HPA regulation, in particular cortisol responses to 1) 2-hour social separation and relocation, 2) sustained challenge, 3) dexamethasone and 4) ACTH administration. In Study 1, hair samples were collected at the end of the BBA testing from 25 infant rhesus monkeys from 2 different stable social groups. In Study 2, hair samples were obtained at three timepoints from 108 adults from 3 different stable social groups (1 in the Spring/Summer and 2 in the Fall/Winter) to examine the temporal stability of the relationship between HCC and HPA axis regulation. In Study 3, subjects included 31 infants and 33 adults from a single social group experiencing social instability following the same procedures as in Studies 1 and 2. Generalized linear models were used to determine if infants' HPA axis activity and regulation predicted HCC in infancy (Study 1), in adulthood with animals living in stable social conditions (Study 2) or in animals living in an unstable social group (Study 3). Results indicated that for both infants and adults living in stable social groups, HCC are associated with the adrenal response to ACTH in infancy. Samples collected in the winter also had higher HCC than those collected in summer. In the unstable social group, adult hair cortisol levels were higher than in the stable social groups. Additionally, there were no consistent relationships between HCC and infant HPA axis regulation among adults or infants living in a group experiencing social instability. These results suggest that the aspects of the HPA axis that drive HCC may differ depending on context. Under stable, non-stressed conditions there seems to be a trait-like association between adrenal responsivity and HCC in infancy and adulthood. However, this association may be reduced or eliminated under conditions of social stress.

Immunosenescence - the role in the immunotherapy of older population

With ageing of their populations, many societies are challenged with serious systemic diseases. One of the causes of these diseases could be the age-related defects in immune system termed immunosenescence. Immunosenescence is characterized by accumulation of memory and non-functional immune cells, impaired signalling due to restricted repertoire of receptors, overall pro-inflammatory environment and complete dysregulation of the immune system. Consequences of immunosenescence are serious, older people are not able to respond to new stimuli, including infections and vaccinations and are more prone to oncologic, neurodegenerative and autoimmune diseases (Ref. 49).

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Calibrated automated thrombin generation in paediatric patients with inflammatory bowel disease

In adults, inflammatory bowel disease (IBD) is associated with an increased risk of thromboembolic complications. The pathogenesis of IBD is not really clear and a high thrombin activity might contribute to disease progression. We wanted to see whether children with IBD have a higher thrombin generation (TG). Patients, material, methods: Plasma samples were collected of 20 patients with IBD and of 60 healthy controls (age range from 10 to 19). TG was measured by means of Calibrated automated thrombography (CAT). The disease activity was estimated, using the Pediatric Crohn‘s Disease Activity Index (PCDAI) for Crohn‘s disease and the Pediatric Ulcerative Colitis Disease Activity Index (PUCAI) for Ulcerative Colitis. In addition, we investigated F1+F2, TAT, TFPI and fibrinogen. Results: There was a significant increase of endogenous thrombin potential (ETP), lag time and time to peak in patients with IBD, while peak showed no difference to healthy controls. ETP and F1+F2 in children with IBD also showed a significant correlation with PCDAI (PUCAI) and fibrinogen. Conclusion: IBD in children is associated with high TG, but this seems to be caused mainly by the inflammatory process and not by any individual disposition.

Enhanced thrombin generation in plasma of severe thrombocytopenic patients due to rFVIIa

RFVIIa-enhanced thrombin generation has been shown to be dependent on platelets. In previous work we have shown that addition of monocytes and rFVIIa to microparticle free plasma causes a distinct thrombin generation. The aim of our study has been to examine whether there is enough surface provided by microparticles in thrombocytopenic plasma to allow an effect of rFVIIa. Patients, methods: Thrombin generation was measured in platelet rich plasma (PRP) and microparticle free plasma (MFP) of thrombocytopenic haemato-oncological patients with and without addition of rVIIa by means of calibrated automated thrombography. Microparticles were analyzed in PRP by FACS flow cytometry. Results: Microparticle free plasma showed no thrombin generation with or without addition of rFVIIa. Addition of rFVIIa to PRP of thrombocytopenic patients led to a significant shortening of lag time and time to peak in thrombin generation, while ETP and peak remained unchanged. Conclusion: Our results show that even in plasma of severe thrombocytopenic patients enough surface may be provided by microparticles to allow an enhancement of thrombin generation by rFVIIa.

No differences in support of thrombin generation by neonatal or adult platelets

Newborns have, despite low clotting factors and poor in vitro platelet function, a well functioning hemostasis. The reason for this is still not completely clear. The aim of our study was to investigate whether phospholipids in neonatal platelets differ from those in adult platelets in their total amount, in their exposure on the platelet surface, and their effect on thrombin generation (TG). Methods: Clotting times of newborn and adult platelet-rich plasma were measured. Effect of newborn and adult platelets on TG was measured by means of CAT (calibrated automated thrombography). In addition, the effect of newborn and adult platelets with or without stimulation by ionophor on TG was measured in a purified prothrombinase complex. Phosphatidylserine-exposure (PS) of newborn and adult platelets was measured by flow cytometry of annexin V binding. The amount of phospholipids (PL) was determined by means of mass spectrometry. Results: Clotting times of platelet-rich plasma (PRP) of newborns stimulated with ionophor showed a significant lower reduction of clotting time than in adult PRP. No differences in the support of TG between neonatal and adult platelets were found in neonatal or adult plasma by means of CAT. In the purified system TG was increased by adding ionophor stimulated platelets but no difference was evident between stimulated newborn and adult platelets. Flow cytometric analysis showed no difference in annexin V binding between adult and newborn platelets. The results of mass spectrometry showed a very similar amount and pattern of PL of adult and newborns platelets. Conclusion: Our results do not provide any evidence that a different PL content or expression of neonatal platelets may alter TG in neonates.

Screening for haemorrhagic disorders in paediatric patients by means of a questionnaire

Aim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.

The impact of thyroid hormone replacement therapy on left ventricular diastolic function in patients with subclinical hypothyroidism

OBJECTIVE

Subclinical hypothyroidism (SH) is associated with a moderately elevated risk of heart failure events among older adults. The objective of our prospective study was to assess the impact of thyroid hormone replacement therapy (HRT) with low doses of L-thyroxine (6.25-25 µg/day) on left ventricular diastolic function in patients with SH.

MATERIALS AND METHODS

33 patients with SH and 25 healthy controls were involved. All participants underwent standard echocardiography and Doppler imaging at baseline and, the patient group, also after a course of HRT.

RESULTS

At baseline, patients with SH showed significantly lower E (0.79 ± 0.22 vs. 0.93 ± 0.19, p < 0.001), E/A ratio (1.19 ± 0.29 vs. 1.31 ± 0.25, p < 0.003), and higher intraventricular septum thickness (IVST) (0.99 ± 0.14 vs. 0.89 ± 0.18, p < 0.001) in comparison with healthy controls. After 6 months of therapy, the E/A ratio underwent significant increase (1.28 ± 0.21 vs. 1.19 ± 0.29, p < 0.001), while the IVS displayed a robust reduction (0.92 ± 0.16 vs. 0.99 ± 0.14, p < 0.001).

CONCLUSIONS

HRT with low-dosed L-thyroxine may improve left ventricular diastolic function in patients with SH.

Spin-electricity conversion induced by spin injection into topological insulators

We report successful spin injection into the surface states of topological insulators by using a spin pumping technique. By measuring the voltage that shows up across the samples as a result of spin pumping, we demonstrate that a spin-electricity conversion effect takes place in the surface states of bulk-insulating topological insulators Bi(1.5)Sb(0.5)Te(1.7)Se(1.3) and Sn-doped Bi(2)Te(2)Se. In this process, the injected spins are converted into a charge current along the Hall direction due to the spin-momentum locking on the surface state.

Incidence of Type 2 diabetes among occupational classes in Sweden: a 35-year follow-up cohort study in middle-aged men

AIMS

To assess if low occupational class was an independent predictor of Type 2 diabetes in men in Sweden over a 35-year follow-up, after adjustment for both conventional risk factors and psychological stress.

METHODS

A random population-based sample of 6874 men aged 47-56 years without a history of diabetes was divided into five occupational classes and the men were followed from 1970 to 2008. Diabetes cases were identified through the Swedish inpatient and death registers. Subdistribution hazard ratios (SHRs) and 95% CIs from competing risk regressions, cumulative incidence and conditional probabilities were calculated, after accounting for the risk of death attributed to other causes.

RESULTS

A total of 907 (13%) men with diabetes were identified over 35 years with a median follow-up of 27.9 years. The cumulative incidence of diabetes, when taking into account death as a competing event, was 11% in high officials, 12% in intermediate non-manual employees, 14% in assistant non-manual employees, 14% in skilled workers, and 16% in unskilled and semi-skilled workers. Men with unskilled and semi-skilled manual occupations had a significantly higher risk of diabetes than high officials (reference) after adjustment for age, BMI, hypertension, smoking and physical activity (SHR 1.39, 95% CI 1.08-1.78). Additional adjustment for self-reported psychological stress did not attenuate the results.

CONCLUSIONS

A low occupational class suggests a greater risk of Type 2 diabetes, independently of conventional risk factors and psychological stress.

Antifungal activity of cinnamic acid derivatives involves inhibition of benzoate 4-hydroxylase (CYP53)

AIMS

CYP53A15, from the sorghum pathogen Cochliobolus lunatus, is involved in detoxification of benzoate, a key intermediate in aromatic compound metabolism in fungi. Because this enzyme is unique to fungi, it is a promising drug target in fungal pathogens of other eukaryotes.

METHODS AND RESULTS

In our work, we showed high antifungal activity of seven cinnamic acid derivatives against C. lunatus and two other fungi, Aspergillus niger and Pleurotus ostreatus. To elucidate the mechanism of action of cinnamic acid derivatives with the most potent antifungal properties, we studied the interactions between these compounds and the active site of C. lunatus cytochrome P450, CYP53A15.

CONCLUSION

We demonstrated that cinnamic acid and at least four of the 42 tested derivatives inhibit CYP53A15 enzymatic activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

By identifying selected derivatives of cinnamic acid as possible antifungal drugs, and CYP53 family enzymes as their targets, we revealed a potential inhibitor-target system for antifungal drug development.

TUGENDHAT: a pilot randomized study on effects of biventricular pacing in patients with bradycardia pacing indication and normal systolic function on heart failure, atrial fibrillation and quality of life (results of 12 month follow-up)

BACKGROUND

Since the late 1990s, a growing number of clinical studies have indicated that long-term permanent right ventricular (RV) apical pacing will induce severe complications such as development of heart failure, increased burden of atrial fibrillation leading to decreased quality of life.

AIM OF THE STUDY

To investigate whether cardiac resynchronization therapy (CRT) using biventricular (BiV) pacing can prevent the development of left ventricular (LV) dysfunction, LV remodelling, worsening of the clinical status and quality of life in chronically RV paced patients with normal LV ejection fraction (EF).

METHODS AND RESULTS

A total of 127 patients with Class I indication for permanent cardiac pacing and without established indication for CRT were subjected to 6 months of RV and BiV pacing in a patient-blinded, randomized crossover trial. Treatment effects of BiV pacing were evaluated for LV function, LV remodelling and clinical status. As compared with RV pacing, BiV pacing did not significantly prevent the decrease of LV function [LVEF 61.0 % (36.0; 68.0) vs 60.5 % (38.5; 67.5) in RV pacing], did not change the functional class according to the New York Heart Association [52 % in Class II vs 53.9 % in Class II in RV pacing, and 3.9 % in Class III vs 6.9 % in Class III in RV pacing], and did not present any changes in quality of life [32.5 (18.0; 80.0) vs 32.0 (21.0; 47.0) indexes in RV pacing].

CONCLUSION

BiV pacing, compared to RV pacing, did not change LV function and quality of life in patients with the absence of LV dysfunction or remodelling, standard bradycardia pacing indications in a pilot phase (12- month follow-up) of the TUGENDHAT trial. The final report will be published after 60-month follow-up termination (Tab. 5, Fig. 3, Ref. 30).

Dances with black widow spiders: dysregulation of glutamate signalling enters centre stage in ADHD

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with impairments across the lifespan. The persistence of ADHD is associated with considerable liability to neuropsychiatric co-morbidity such as depression, anxiety and substance use disorder. The substantial heritability of ADHD is well documented and recent genome-wide analyses for risk genes revealed synaptic adhesion molecules (e.g. latrophilin-3, LPHN3; fibronectin leucine-rich repeat transmembrane protein-3, FLRT3), glutamate receptors (e.g. metabotropic glutamate receptor-5, GRM5) and mediators of intracellular signalling pathways (e.g. nitric oxide synthase-1, NOS1). These genes encode principal components of the molecular machinery that connects pre- and postsynaptic neurons, facilitates glutamatergic transmission, controls synaptic plasticity and empowers intersecting neural circuits to process and refine information. Thus, identification of genetic variation affecting molecules essential for the formation, specification and function of excitatory synapses is refocusing research efforts on ADHD pathogenesis to include the long-neglected glutamate system.

Parental perceptions of and concerns about child's body weight in eight European countries--the IDEFICS study

OBJECTIVES

To evaluate parental perceptions of and concern about child's body weight and general health in children in a European cohort.

DESIGN

Cross-sectional multi-centre study in eight European countries.

PARTICIPANTS

16,220 children, ages 2-9 years.

METHODS

Parents completed a questionnaire regarding children's health and weight and concern about overweight and underweight. Objective children's weight categories from the International Obesity Task Force were used. Logistic regression models were utilized to identify predictors of accurate weight perception.

RESULTS

Parental weight perception corresponded overall to children's mean body mass index (BMI) z-scores, with important exceptions. About one-third of the total indicated concern about underweight, paradoxically most often parents of children in the overweight or obesity categories. In 63%, parents of children in the overweight category marked 'proper weight'. The strongest predictor for accurate parental weight perception for children with overweight and obesity was BMI z-score (odds ratio [OR] = 7.2, 95% confidence interval [CI] 6.1-8.7). Compared to Southern Europe, ORs for accurate parental weight perception were 4.4 (95% CI 3.3-6.0) in Northern Europe and 3.4 (95% CI 2.7-4.2) in Central Europe.

CONCLUSION

Parents of children categorized as being overweight or obese systematically underestimated weight. Parents differed regionally regarding accurate weight perception and concern about overweight and underweight.

Screening for depression: only one piece of the puzzle

In this issue of NDT, van den Beukel et al. from the Netherlands suggest that a 5-item survey questionnaire might be used to replace the Beck Depression Index to screen patients with chronic kidney disease (CKD) for depression. The nephrology community is at a tipping point in terms of the assessment of outcomes, especially among patients on dialysis. Indeed, the entire healthcare community has begun to shift its focus to patient-reported outcomes (PROs), including quality of life, patient satisfaction and the psychosocial determinants of health. Beyond depression, there are a myriad of aspects of psychological distress that include anxiety, worrying, fear of progression of kidney disease and the fear of the future in general, death and dying, hopelessness, questions around the meaning of life and the experience of recurrent psychological and physical trauma through the CKD trajectory. We encourage the community and its researchers to embrace and research PROs, with the aim to create a holistic, patient-centered model of care for patients at all stages of CKD, including those on chronic dialysis and after transplantation, keeping the whole person-and their families-in mind.

Perceived stress and incidence of Type 2 diabetes: a 35-year follow-up study of middle-aged Swedish men

AIM

To explore incident cases of diagnosed diabetes over 35 years of follow-up in relation to self-perceived stress at baseline.

METHODS

This was a population-based random sample of 7251 men derived from the Primary Prevention Trial Study, aged 47-56 years at baseline and without prior history of diabetes, coronary heart disease and stroke. Incident diabetes was identified from hospital discharge and death registries as principal or secondary diagnosis. Cox proportional hazards regression was used to evaluate the potential association between stress and diabetes.

RESULTS

During a 35-year follow-up, a total of 899 men were identified with diabetes. The crude incidence was 5.2 per 1000 persons-years. At baseline, 15.5% men reported permanent stress related to conditions at work or home. After adjusting for age and competing risk of death, the estimated 35-year conditional probability of diabetes in men with permanent stress was 42.6%, compared with 31.0% for those with periodic stress and 31.2% with no stress. In age-adjusted Cox regression analysis, men with permanent stress had a higher risk of diabetes [hazard ratio 1.52 (95% CI 1.26-1.82)] compared with men with no (referent) or periodic stress [hazard ratio 1.09 (95% CI 0.94-1.27)]. The association between stress and diabetes was slightly attenuated but remained significant after adjustment for age, socio-economic status, physical inactivity, BMI, systolic blood pressure and use of anti-hypertensive medication [hazard ratio 1.45 (95% CI 1.20-1.75)]. When examining principal diagnosis of diabetes cases separately from secondary diagnoses cases, the excess risk of diabetes associated with permanent stress remained significant both in age (only) and multivariable adjusted models.

CONCLUSION

Self-perceived permanent stress is an important long-term predictor of diagnosed diabetes, independently of socio-economic status, BMI and other conventional Type 2 diabetes risk factors.