Enhanced visualization in endoleak detection through iterative and AI-noise optimized spectral reconstructions.

To assess the image quality parameters of dual-energy computed tomography angiography (DECTA) 40-, and 60 keV virtual monoenergetic images (VMIs) combined with deep learning-based image reconstruction model (DLM) and iterative reconstructions (IR). CT scans of 28 post EVAR patients were enrolled. The 60 s delayed phase of DECTA was evaluated. Objective [noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR)] and subjective (overall image quality and endoleak conspicuity - 3 blinded readers assessment) image quality analyses were performed. The following reconstructions were evaluated: VMI 40, 60 keV VMI; IR VMI 40, 60 keV; DLM VMI 40, 60 keV. The noise level of the DLM VMI images was approximately 50% lower than that of VMI reconstruction. The highest CNR and SNR values were measured in VMI DLM images. The mean CNR in endoleak in 40 keV was accounted for as 1.83 ± 1.2; 2.07 ± 2.02; 3.6 ± 3.26 in VMI, VMI IR, and VMI DLM, respectively. The DLM algorithm significantly reduced noise and increased lesion conspicuity, resulting in higher objective and subjective image quality compared to other reconstruction techniques. The application of DLM algorithms to low-energy VMIs significantly enhances the diagnostic value of DECTA in evaluating endoleaks. DLM reconstructions surpass traditional VMIs and IR in terms of image quality.

The value of metal artifact reduction and iterative algorithms in dual energy CT angiography in patients after complex endovascular aortic aneurysm repair.

Rationale and objectives: Evaluation of the diagnostic value of linearly blended (LB) and virtual monoenergetic images (VMI) reconstruction techniques with and without metal artifacts reduction (MAR) and of adaptive statistical iterative reconstructions (ASIR) in the assessment of target vessels after branched/fenestrated endovascular aortic repair (f/brEVAR) procedures. Materials and methods: CT scans of 28 patients were used in this study. Arterial phase of examination was obtained using a dual-energy fast-kVp switching scanner. CT numbers in the aorta, celiac trunk, superior mesenteric artery, and renal arteries were measured in the following reconstructions: LB, VMI 60 keV, VMI MAR 60 keV, VMI ASIR 60 % 60 keV. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated for each reconstruction. Luminal diameters (measurements at 2 levels of stent) and subjective image quality (5-point Likert scale) were assessed (2 readers, blinded to the type of reconstruction). Results: The highest mean values of CNR and SNR in vascular structures were obtained in VMI MAR 60 keV (CNR 12.526 ± 2.46, SNR 17.398 ± 2.52), lower in VMI 60 keV (CNR 11.508 ± 2.01, SNR 16.524 ± 2.07) and VMI ASIR (CNR 11.086 ± 1.78, SNR 15.928 ± 1.82), and the lowest in LB (CNR 6.808 ± 0.79, SNR 11.492 ± 0.79) reconstructions. There were no statistically significant differences in the measurements of the stent width between reconstructions (p > 0.05). The highest subjective image quality was obtained in the ASIR VMI (4.25 ± 0.44) and the lowest in the MAR VMI (1.57 ± 0.5) reconstruction. Conclusion: Despite obtaining the highest values of SNR and CNR in the MAR VMI reconstruction, the subjective diagnostic value was the lowest for this technique due to significant artifacts. The type of reconstruction did not significantly affect vessel diameter measurements (p > 0.05). Iterative reconstructions raised both objective and subjective image quality.

Fair and equitable AI in biomedical research and healthcare: Social science perspectives.

Artificial intelligence (AI) offers opportunities but also challenges for biomedical research and healthcare. This position paper shares the results of the international conference "Fair medicine and AI" (online 3-5 March 2021). Scholars from science and technology studies (STS), gender studies, and ethics of science and technology formulated opportunities, challenges, and research and development desiderata for AI in healthcare. AI systems and solutions, which are being rapidly developed and applied, may have undesirable and unintended consequences including the risk of perpetuating health inequalities for marginalized groups. Socially robust development and implications of AI in healthcare require urgent investigation. There is a particular dearth of studies in human-AI interaction and how this may best be configured to dependably deliver safe, effective and equitable healthcare. To address these challenges, we need to establish diverse and interdisciplinary teams equipped to develop and apply medical AI in a fair, accountable and transparent manner. We formulate the importance of including social science perspectives in the development of intersectionally beneficent and equitable AI for biomedical research and healthcare, in part by strengthening AI health evaluation.

Prehospital Predictors for Urgent Neurosurgical Intervention in the Head Trauma Patient: A 2-Year Multicenter Retrospective Study.

Background: Traumatic brain injury (TBI) is the main cause of disability in the world. Prehospital diagnosis of patients requiring rapid neurosurgical intervention and the earliest possible introduction of procedures preventing secondary brain injuries (SBI) are crucial. Methodology and Study Population. The authors of this paper assumed that certain age groups with specific injuries are more likely to require urgent neurosurgical intervention compared with patients who did not require such an intervention. Out of 54,814 head CT scans, based on the inclusion criteria, 7,864 were selected for the study. Data such as sex, age, the mechanism of injury, comorbid trauma, and abnormal findings in the examination of patients qualified for urgent neurosurgical intervention were analyzed in order to find statistically significant factors through a comparison with all head trauma patients. Results: Patients qualified for urgent neurosurgical intervention were significantly older compared with the others (63 years vs. 49 years). Patients transferred from the emergency department directly to the operating room were more often admitted to the hospital due to the fall (64.1% vs. 45.1%, p = 0.004). The following were observed much more commonly among the patients qualified for urgent neurosurgical intervention than in the entire study group of subjects with traumatic brain injury (TBI), e.g., calf deformity (2.2% vs. 0.1%, p = 0.019) and bleeding from the mouth (4.3% vs. 0.0%, p < 0.001). On the other hand, superciliary arch wounds were observed much less commonly than in the entire group (0.0% vs. 5%, p = 0.221). Conclusion: Patients admitted directly to the operating neurosurgical room from emergency departments constitute a small percentage of TBI patients, and their prognosis for normal performance status upon discharge is poor. Maximum efforts should be made to distinguish these patients and to start proper treatment even during prehospital care.

Improved Detection of Endoleaks in Virtual Monoenergetic Images in Dual-Energy CT Angiography Following EVAR.

OBJECTIVES: The objective of this prospective study was to evaluate the virtual monoenergetic images (VMI) and virtual noncontrast (VNC) phase in the detection of endoleaks after endovascular abdominal aortic repair (EVAR). The potential dose reduction of abbreviated examination protocols was calculated. MATERIALS AND METHODS: Ninety-seven patients after the EVAR procedure were enrolled in this study. An initial single-source noncontrast acquisition was followed by two dual-energy acquisitions (arterial and 60 s delayed). Fast-kVp switching scanner was used. VNC images were reconstructed from the delayed phase. First examination session (reference) included a full triphasic study protocol consisting of true noncontrast (TNC) images and two postcontrast phases, the latter ones presented as classical polyenergetic reconstructions. Reading sessions II and III were performed by two independent and blinded readers evaluating VMIs in abbreviated protocols-biphasic (VNC + arterial, delayed phase), monophasic (VNC + delayed phase). The diagnostic accuracy of sessions II and III was calculated. RESULTS: The calculated sensitivity of the biphasic protocol with the use of VMIs in endoleak detection was 100%, with a statistically significant increase in the number of endoleaks detected in comparison with the reference study. The monophasic protocol showed 83.33% sensitivity. The use of abbreviated examination protocols led to a decrease in the mean effective dose (ED) of 23.28% (biphasic protocol) and 61.37% (monophasic protocol). CONCLUSION: The use of VMIs increases the number of endoleaks diagnosed with a possible radiation reduction by up to » (biphasic protocol). Further reduction to a monophasic protocol leads to over 60% dose reduction but with a decrease in diagnostic accuracy.

Interplay of noise induced stability and stochastic resetting.

Stochastic resetting and noise-enhanced stability are two phenomena that can affect the lifetime and relaxation of nonequilibrium states. They can be considered measures of controlling the efficiency of the completion process when a stochastic system has to reach the desired state. Here, we study the interaction of random (Poissonian) resetting and stochastic dynamics in unstable potentials. Unlike noise-induced stability that increases the relaxation time, the stochastic resetting may eliminate winding trajectories contributing to the lifetime and accelerate the escape kinetics from unstable states. In this paper, we present a framework to analyze compromises between the two contrasting phenomena in noise-driven kinetics subject to random restarts.

Selective human cells in vitro transduction with porcine endogenous retrovirus (PERV).

Porcine xenograft transplantation raises concerns in humans about the risk of infection with porcine endogenous retroviruses (PERV) as they are an integral part of the pig genome and are therefore very difficult to exclude. In this study, for the first time, a relationship between the provirus genes sequences and released virions from pig cell line and the embedded sequence of this retrovirus in infected human cells was analyzed. PERV infection of human cells HEK-293 and HeLa and detection of PERV in pig PK-15 cells and supernatant were assessed by QPCR or RT-QPCR using primers specific for envA, envB, gag, pol genes and LTR region. Sequence analysis was performed at the DNA level and changes in the amino acid sequence were deduced in silico. Fifty nucleotide substitutions (45 in pol, 3 in gag and one each in envA and envB) were detected and most of these were heterozygous (42), which were present mainly in PK-15 cells. Our results show that sequence of the pol gene and the Pol protein is less conserved compared to the other PERV genes and PERV with some polymorphisms were not released from pig cells or/and do not infect human cells. PERV virions with a homozygous allele system were released from PK-15 cells, although their sequence replicated on the basis of the heterozygous PERV provirus sequence in PK-15. The newly discovered selective transduction of human cells with PERV will be helpful in studying the characteristics and genetic variability of the retrovirus genes to ensure safe xenotransplantation. Keywords: PERV; porcine endogenous retroviruses; infection; genetic polymorphism; xenotransplantation.

Aspects of the Epigenetic Regulation of EMT Related to Cancer Metastasis.

Epithelial to mesenchymal transition (EMT) occurs during the pathological process associated with tumor progression and is considered to influence and promote the metastatic cascade. Characterized by loss of cell adhesion and apex base polarity, EMT enhances cell motility and metastasis. The key markers of the epithelial to mesenchymal transition are proteins characteristic of the epithelial phenotype, e.g., E-cadherin, cytokeratins, occludin, or desmoplakin, the concentration and activity of which are reduced during this process. On the other hand, as a result of acquiring the characteristics of mesenchymal cells, an increased amount of N-cadherin, vimentin, fibronectin, or vitronectin is observed. Importantly, epithelial cells undergo partial EMT where some of the cells show both epithelial and mesenchymal characteristics. The significant influence of epigenetic regulatory mechanisms is observed in the gene expression involved in EMT. Among the epigenetic modifications accompanying incorrect genetic reprogramming in cancer are changes in the level of DNA methylation within the CpG islands and posttranslational covalent changes of histone proteins. All observed modifications, which are stable but reversible changes, affect the level of gene expression leading to the development and progression of the disease, and consequently affect the uncontrolled growth of the population of cancer cells.

Impact of Moderate Individually Tailored Physical Activity in Multiple Sclerosis Patients with Fatigue on Functional, Cognitive, Emotional State, and Postural Stability.

Multiple sclerosis (MS) is a chronic disease, with fatigue syndrome as one of the main symptoms. The aim of this study was to demonstrate that moderate physical activity (MPA) may have a beneficial effect on postural stability, balance, and clinical parameters. The research group consisted of 137 randomized patients hospitalized at the Department of Neurological Rehabilitation, Medical University of Lodz. Finally, 76 patients were qualified who were divided into two groups-high fatigue (HF) and low fatigue (LF). Participants were assessed twice: before and after a 4-week MPA program using: the Expanded Disability Status Scale (EDSS), the Fatigue Severity Scale (FSS), the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Beck Depression Inventory (BDI), and the Geriatric Depression Scale (GDS), and stabilometric platform tests were performed. Results obtained after the 4-week MPA program showed a positive effect of the MPA with differences between LF and HF groups. The MPA was more effective in MS patients with LF in cognitive functions, functional status, and postural stability but among HF patients in an emotional state, especially in MS patients below 65 years, although in total, both groups benefited from the MPA.

Observing changes in human functioning during induced sleep deficiency and recovery periods.

Prolonged periods of sleep restriction seem to be common in the contemporary world. Sleep loss causes perturbations of circadian rhythmicity and degradation of waking alertness as reflected in attention, cognitive efficiency and memory. Understanding whether and how the human brain recovers from chronic sleep loss is important not only from a scientific but also from a public health perspective. In this work we report on behavioral, motor, and neurophysiological correlates of sleep loss in healthy adults in an unprecedented study conducted in natural conditions and comprising 21 consecutive days divided into periods of 4 days of regular life (a baseline), 10 days of chronic partial sleep restriction (30% reduction relative to individual sleep need) and 7 days of recovery. Throughout the whole experiment we continuously measured the spontaneous locomotor activity by means of actigraphy with 1-minute resolution. On a daily basis the subjects were undergoing EEG measurements (64-electrodes with 500 Hz sampling frequency): resting state with eyes open and closed (8 minutes long each) followed by Stroop task lasting 22 minutes. Altogether we analyzed actigraphy (distributions of rest and activity durations), behavioral measures (reaction times and accuracy from Stroop task) and EEG (amplitudes, latencies and scalp maps of event-related potentials from Stroop task and power spectra from resting states). We observed unanimous deterioration in all the measures during sleep restriction. Further results indicate that a week of recovery subsequent to prolonged periods of sleep restriction is insufficient to recover fully. Only one measure (mean reaction time in Stroop task) reverted to baseline values, while the others did not.

Nutritional Supplements and Neuroprotective Diets and Their Potential Clinical Significance in Post-Stroke Rehabilitation.

Nutrition and rehabilitation are crucial in post-stroke recovery, especially in the elderly. Since stroke is the leading cause of long-term disability, there is a need to promote special, individually tailored nutrition strategies targeting older patients with low motor ability. Chronic stroke survivors have higher risk of developing nutrition-related chronic diseases, such as sarcopenia, anemia, type 2 diabetes mellitus and osteoporosis. Moreover, reduced motor activity, cognitive impairment and depression might be aggravated by poor malnutrition status. Accumulated data suggest that nutritional supplements and neuroprotective diets can be associated with better effectiveness of post-stroke rehabilitation as well as brain recovery. Therefore, this review focuses on preventive strategies that can improve dietary intake and change dietary patterns. We highlight the importance of neuroprotective diets, the problem of dysphagia and the role of nutrition in rehabilitation. This article focuses on potential nutritional supplements and neuroprotective diets that may have an impact on functional recovery during and after rehabilitation. Moreover, a new approach to post-stroke neuroplasticity including the use of agents from marine sources such as fucoxanthin and tramiprosate as compounds that might be used as potential neuroprotectants with antioxidative and anti-inflammatory properties is introduced.

Dichotomous flow with thermal diffusion and stochastic resetting.

We consider properties of one-dimensional diffusive dichotomous flow and discuss effects of stochastic resonant activation (SRA) in the presence of a statistically independent random resetting mechanism. Resonant activation and stochastic resetting are two similar effects, as both of them can optimize the noise-induced escape. Our studies show completely different origins of optimization in adapted setups. Efficiency of stochastic resetting relies on elimination of suboptimal trajectories, while SRA is associated with matching of time scales in the dynamic environment. Consequently, both effects can be easily tracked by studying their asymptotic properties. Finally, we show that stochastic resetting cannot be easily used to further optimize the SRA in symmetric setups.

Single-Nucleotide Polymorphisms in Oxidative Stress-Related Genes and the Risk of a Stroke in a Polish Population-A Preliminary Study.

The present preliminary case-control study was undertaken to detect the potential association of six single nucleotide polymorphisms (SNPs) in oxidative stress-related genes: SOD2 (c.47T > C; rs4880), CAT (c.-89A > T; rs7943316), GPX4 (c.660T > A; rs713041), NOS1 (g.117803515C > T; rs1879417) and NOS2 (c.1823C > T; rs2297518 and c.-227G > C; rs10459953) and the occurrence of a stroke. The SNPs were determined using the TaqMan® Allelic Discrimination Assay in 107 patients with strokes and 107 age- and sex-matched individuals who had not experienced cerebrovascular accidents. The T alleles of the rs4880 were positively correlated with a stroke (bootstrap OR 1.31; 1.07-1.59 95% CI). In the case of the rs713041, an association with the T allele was found (bootstrap OR 1.36; 1.12-1.67). In addition, the occurrence of a stroke was associated with the presence of the C allele of the rs1879417 (bootstrap OR 1.32; 1.09-1.61). We also found that the C/C genotype and C allele of the rs2297518 increased the risk of a stroke (bootstrap ORs 7.00; 4.34-11.29 and 4.96; 3.88-6.34, respectively). Moreover, the C allele of the rs10459953 was associated with an increased occurrence of this disease (bootstrap OR 1.31; 1.08-1.60). These results indicated that genetics variants in the SOD2, GPX4, NOS1 and NOS2 might be associated with susceptibility to strokes in the Polish population.

The Relationship between Cognitive Dysfunction and Postural Stability in Multiple Sclerosis.

Background and Objectives: Multiple Sclerosis (MS) is a demyelinating disease of the central nervous system (CNS), most commonly characterized by balance dysfunction, fatigue syndrome and cognitive impairment. The goal of our study was to determine the association between cognitive functions and static posture control. Materials and Methods: The research group consisted of 76 randomized MS patients (ICDG 35.0) hospitalized at the Neurological Rehabilitation Clinic of the Medical University of Lodz. This group was divided into three subgroups according to the cognitive assessment based on the Mini Mental State Examination (MMSE) for patients over 65 years of age and the Montreal Cognitive Assessment (MoCA) under the age of 65. Fatigue syndrome was assessed using the Fatigue Severity Scale (FSS), and postural stability using a stabilometric platform. Results: The men demonstrated poorer stabilometric platform measurements than the women. Statistically significant differences were observed between patients without dysfunction and severe cognitive impairment. The results of the stabilometric platform were found to correlate with body mass index in all three groups of patients (Spearman's test). Conclusions: Body mass index and cognition have impact on postural stability in MS patients with moderate disability and fatigue syndrome.

New Strategies for Rehabilitation and Pharmacological Treatment of Fatigue Syndrome in Multiple Sclerosis.

Multiple sclerosis (MS) is the most common autoimmune disease of the central nervous system (CNS), with an inflammatory demyelinating basis and a progressive course. The course of the disease is very diverse and unpredictable. Patients face many problems on a daily basis, such as problems with vision; sensory, balance, and gait disturbances; pain; muscle weakness; spasticity; tremor; urinary and fecal disorders; depression; and rapidly growing fatigue, which significantly influences quality of life among MS patients. Excessive fatigue occurs in most MS patients in all stages of this disease and is named MS-related fatigue. The crucial issue is the lack of effective treatment; therefore, this review focuses not only on the most common treatment methods, but also on additional novel therapies such as whole-body cryotherapy (WBC), functional electrical stimulation (FES), and non-invasive brain stimulation (NIBS). We also highlight the advantages and disadvantages of the most popular clinical scales used to measure fatigue. The entire understanding of the origins of MS-related fatigue may lead to the development of more effective strategies that can improve quality of life among MS patients. A literature search was performed using MEDLINE, EMBASE, and PEDro databases.

Nonlinear friction in underdamped anharmonic stochastic oscillators.

Non-equilibrium stationary states of overdamped anharmonic stochastic oscillators driven by Lévy noise are typically multimodal. The very same situation is recorded for an underdamped Lévy noise-driven motion in single-well potentials with linear friction. Within the current article, we relax the assumption that the friction experienced by a particle is linear. Using computer simulations, we study underdamped motions in single-well potentials in the regime of nonlinear friction. We demonstrate that it is relatively easy to observe multimodality in the velocity distribution as it is determined by the friction itself and it is the same as the multimodality in the overdamped case with the analogous deterministic force. Contrary to the velocity marginal density, it is more difficult to induce multimodality in the position. Nevertheless, for a fine-tuned nonlinear friction, the spatial multimodality can be recorded.

Delineating elastic properties of kinesin linker and their sensitivity to point mutations.

We analyze free energy estimators from simulation trials mimicking single-molecule pulling experiments on a neck linker of a kinesin motor. For that purpose, we have performed a version of steered molecular dynamics (SMD) calculations. The sample trajectories have been analyzed to derive distribution of work done on the system. In order to induce stretching of the linker, we have applied a constant pulling force to the molecule and allowed for a subsequent relaxation of its structure. The use of fluctuation relations (FR) relevant to non-equilibrium systems subject to thermal fluctuations allows us to assess the difference in free energy between stretched and relaxed conformations. To further understand effects of potential mutations on elastic properties of the linker, we have performed similar in silico studies on a structure formed of a polyalanine sequence (Ala-only) and on three other structures, created by substituting selected types of amino acid residues in the linker's sequence with alanine (Ala) ones. The results of SMD simulations indicate a crucial role played by the Asparagine (Asn) and Lysine (Lys) residues in controlling stretching and relaxation properties of the linker domain of the motor.

Erratum: Subdiffusive continuous-time random walks with stochastic resetting [Phys. Rev. E 99, 052116 (2019)].

This corrects the article DOI: 10.1103/PhysRevE.99.052116.

Morin exerts anti-metastatic, anti-proliferative and anti-adhesive effect in ovarian cancer cells: an in vitro studies.

The influence of morin hydrate on changes of proliferative, metastatic, and adhesive potential of human ovarian cancer cells concerning the influence of decitabine, and decitabine with trichostatin A, and in comparison to untreated cells, were analyzed. The effect of morin hydrate, decitabine, and trichostatin A were examined in A2780 and SKOV-3 ovarian cancer cell lines using MTS assay, clonogenic assay, adhesion to endothelial HMEC-1 cells, transwell migration assay and cell cycle analysis. The expression level of epithelial to mesenchymal transition (EMT) markers was quantified using PCR Array in relation to the level of global methylation determined with Methylated DNA Quantification Kit. We observed statistically significant inhibition of adhesive and migratory potential of both cell lines and the accumulation of G0/G1 phase A2780 cells after treatment with morin hydrate. Our studies confirmed the influence of morin hydrate on down-regulation of genes considered as up-regulated during EMT, and up-regulation of some genes considered as down-regulated during EMT in A2780 and SKOV-3 cells. Phenotypic changes were associated with molecular changes in cells, eg. decrease of the expression level of genes associated with adhesion, and an increase of genes down-regulated during EMT, after morin hydrate treatment in comparison to untreated control cells in both cell lines, were observed.

Peculiarities of escape kinetics in the presence of athermal noises.

Stochastic evolution of various dynamic systems and reaction networks is commonly described in terms of noise assisted escape of an overdamped particle from a potential well, as devised by the paradigmatic Langevin equation in which additive Gaussian stochastic force reproduces effects of thermal fluctuations from the reservoir. When implemented for systems close to equilibrium, the approach correctly explains the emergence of the Boltzmann distribution for the ensemble of trajectories generated by the Langevin equation and relates the intensity of the noise strength to the mobility. This scenario can be further generalized to include effects of non-Gaussian, burstlike forcing modeled by Lévy noise. In this case, however, the pulsatile additive noise cannot be treated as the internal (thermal) since the relation between the strength of the friction and variance of the noise is violated. Heavy tails of Lévy noise distributions not only facilitate escape kinetics, but also, more importantly, change the escape protocol by altering the final stationary state to a non-Boltzmann, nonequilibrium form. As a result, contrary to the kinetics induced by a Gaussian white noise, escape rates in environments with Lévy noise are determined not by the barrier height, but instead by the barrier width. We further discuss consequences of simultaneous action of thermal and Lévy noises on statistics of passage times and population of reactants in double-well potentials.