Effect of Live and Fragmented Saccharomyces cerevisiae in the Feed of Pigs Challenged with Mycoplasma hyopneumoniae.

Currently, the responsible use of antimicrobials in pigs has allowed the continuous development of alternatives to these antimicrobials. In this study, we describe the impact of treatments with two probiotics, one based on live Saccharomyces cerevisiae (S. cerevisiae) and another based on fragmented S. cerevisiae (beta-glucans), that were administered to piglets at birth and at prechallenge with Mycoplasma hyopneumoniae. Thirty-two pigs were divided into four groups of eight animals each. The animals had free access to water and food. The groups were as follows: Group A, untreated negative control; Group B, inoculated by nebulization with M. hyopneumoniae positive control; Group C, first treated with disintegrated S. cerevisiae (disintegrated Sc) and inoculated by nebulization with M. hyopneumoniae; and Group D, treated with live S. cerevisiae yeast (live Sc) and inoculated by nebulization with M. hyopneumoniae. In a previous study, we found that on Days 1 and 21 of blood sampling, nine proinflammatory cytokines were secreted, and an increase in their secretion occurred for only five of them: TNF-α, INF-α, INF-γ, IL-10, and IL-12 p40. The results of the clinical evolution, the degree of pneumonic lesions, and the productive parameters of treated Groups C and D suggest that S. cerevisiae has an immunomodulatory effect in chronic proliferative M. hyopneumoniae pneumonia characterized by delayed hypersensitivity, which depends on the alteration or modulation of the respiratory immune response. The data presented in this study showed that S. cerevisiae contributed to the innate resistance of infected pigs.

Risk of herpes zoster in adults with SARS-CoV-2 infection in Spain: A population-based, retrospective cohort study.

OBJECTIVES: We aimed to compare the risk of herpes zoster (HZ) in adults with and without laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: This retrospective dynamic cohort study analyzed data from a public healthcare database in Spain between November 2020 and October 2021. The main outcome was incident cases of HZ in individuals ≥18-year-old. Relative risk (RR) of HZ in SARS-CoV-2-confirmed versus SARS-CoV-2-free individuals was estimated by a multivariable negative binomial regression adjusted by age, sex, and comorbidities. RESULTS: Data from 4,085,590 adults were analyzed. The overall HZ incidence rate in adults was 5.76 (95% confidence interval [CI], 5.66-5.85) cases per 1000 person-years. Individuals ≥18-year-old with SARS-CoV-2-confirmed infection had a 19% higher risk of developing HZ versus SARS-CoV-2-free ≥18-year-olds (adjusted RR = 1.19; 95% CI, 1.09-1.29); this percentage was 16% (adjusted RR = 1.16; 95% CI, 1.05-1.29) in ≥50-year-olds. Severe (hospitalized) cases of SARS-CoV-2 infection had a 64% (if ≥18 years old) or 44% (if ≥50 years old) higher risk of HZ versus nonhospitalized cases. CONCLUSION: These results support an association between SARS-CoV-2 infection and HZ, with a greater HZ risk in severe cases of SARS-CoV-2 infection.

One-stage or two-stage elective coronary artery bypass graft surgery and abdominal aortic aneurysm open repair in low and moderate cardiac surgical risk patients.

OBJECTIVES: Coronary artery disease (CAD) and abdominal aortic aneurysm (AAA) are common arterial pathologies that might occur simultaneously; however, there is not enough evidence about the optimal strategy for patients with concomitant indications of coronary artery bypass grafting (CABG) and open repair of the AAA (AAOR). This study aims to present the outcomes in low and moderate cardiac surgical risk patients who underwent one-stage or two-stage elective CABG and AAOR in a middle-income country. METHODS: An observational, retrospective case series study was conducted. Patients who had low and moderate cardiac surgical risk (less than 8% mortality risk on the STS score) and had the concomitant indication for CABG and AAOR between December 2005 and August 2021 were included. Patients were assigned to one of three strategies: Group 1 underwent one-stage surgery for CABG and AAOR, Group 2 underwent two-stage surgery within the same in-patient stay, and Group 3 underwent two-stage surgery in a new in-patient stay within 6 months. RESULTS: Twenty seven, patients with simultaneous requirements of CABG and AAOR were identified, with a mean age of 69.5 ± 6.1 years and 92.6% were male. The most common comorbidities were hypertension at 77.8% and dyslipidemia at 55.6%. The average mortality risk calculated by the STS score was 2.09% ± 1.53%. In Group 1 (n = 9), 1/9 had in-hospital mortality and no reinterventions were needed. In Group 2 (n = 10), 1/10 had in-hospital mortality, and the most common postoperative complication was acute kidney injury 2/10. Furthermore, 2/10 required a reintervention. In Group 3 (n = 8), no in-hospital mortality was present, however, complications such as sepsis, atrial fibrillation, and acute kidney injury occurred in 2/8 patients each, and 2/8 required a reintervention. CONCLUSION: Patients with CAD and AAA that need a concomitant surgical correction with CABG and an AAOR are uncommon in contemporary practice, given the advances in endovascular therapy. When indicated, one-stage surgery can be performed in patients with low cardiac surgical risk, proper patient selection plays a fundamental role and might be performed in experienced centers. However, two-staged surgeries at the same or different inpatient stay may be considered for asymptomatic AAA with close monitoring during the postoperative period. These findings can hold significance for addressing sociodemographic barriers in low and middle-income countries. More robust and extensive studies are needed to make clear comparisons between the different strategies.

Cellular Immunity of SARS-CoV-2 in the Borriana COVID-19 Cohort: A Nested Case-Control Study.

Our goal was to determine the cellular immune response (CIR) in a sample of the Borriana COVID-19 cohort (Spain) to identify associated factors and their relationship with infection, reinfection and sequelae. We conducted a nested case-control study using a randomly selected sample of 225 individuals aged 18 and older, including 36 individuals naïve to the SARS-CoV-2 infection and 189 infected patients. We employed flow-cytometry-based immunoassays for intracellular cytokine staining, using Wuhan and BA.2 antigens, and chemiluminescence microparticle immunoassay to detect SARS-CoV-2 antibodies. Logistic regression models were applied. A total of 215 (95.6%) participants exhibited T-cell response (TCR) to at least one antigen. Positive responses of CD4+ and CD8+ T cells were 89.8% and 85.3%, respectively. No difference in CIR was found between naïve and infected patients. Patients who experienced sequelae exhibited a higher CIR than those without. A positive correlation was observed between TCR and anti-spike IgG levels. Factors positively associated with the TCR included blood group A, number of SARS-CoV-2 vaccine doses received, and anti-N IgM; factors inversely related were the time elapsed since the last vaccine dose or infection, and blood group B. These findings contribute valuable insights into the nuanced immune landscape shaped by SARS-CoV-2 infection and vaccination.

Impact on Hospital Resource Utilization of Endoluminal Bypass Using the Viabahn Endoprosthesis with Heparin Bioactive Surface Compared With Surgical Femoropopliteal Bypass.

OBJECTIVE: To assess the impact of heparin-bonded endoprosthesis compared with femoropopliteal bypass on key hospital resources and revenues up to 1-year follow-up. DESIGN: A 2-arm scenario resource consumption data analysis was modeled based on a multicentre prospective randomized controlled trial. SETTING: Six centers in the Netherlands. PARTICIPANTS: A total of 100 patients were assigned to 2 arms (50 each arm). The first arm evaluated endovascular treatment using the heparin-bonded Viabahn endoprosthesis and the second the femoropopliteal bypass. Resource consumption rates were compared between arms. PRIMARY AND SECONDARY OUTCOMES MEASURES: Resource consumption rates, including hospital stay for bypass procedure, operating room time, type of anesthesia, number of used (endo)grafts, use of different types of bed locations (vascular ward, medium or intensive care), readmission for wound infections, and reinterventions over a period of 12 months. RESULTS: Endovascular repair used fewer hospital resources, with an overall difference of €149.983. Hospital stay was 118 days less (261 vs 379), including 21 fewer days in medium/intensive care (5 vs 26) and 50 fewer operating room hours (100 vs 150). Fewer patients required general anesthesia (31 vs 39), and there were less surgical site infections (3 vs 12). In the surgical bypass group, there were 18 fewer days of hospital stay related to reinterventions (80 vs 62), and the cost of the devices was €309.996, cheaper. The total monetary difference was € 160.013, in favor of the femoropopliteal bypass (€3.200, per patient). CONCLUSIONS: Endovascular repair of the superficial femoral artery reduces the use of valuable hospital resources. Its major limitation is the cost of the devices, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall. These benefits may outweigh the fewer reinterventions in the surgical bypass group. REGISTRATION: The SuperB Trial was registered in clinicaltrials.gov; NCT-ID: NCT01220245. CLINICAL IMPACT: Modeling is a useful technique to predict the impact of treatment modalities on hospital resources and revenue. This study uses real-world data from the SuperB Trial to compare two treatment strategies of superficial femoral artery disease, reflecting actual clinical practice and patient outcomes. The analysis focused on direct costs associated with hospital resources and device usage without considering indirect costs or long-term cost-effectiveness. The analysis showed that endovascular repair reduces the use of valuable hospital resources. Its major limitation is device costs, which should be balanced against the reduction in peri-procedural morbidity and faster recovery. In the context of shortage of hospital beds, it offers capacity benefits, allowing for the treatment of more patients overall.

Translation velocity determines the efficacy of engineered suppressor tRNAs on pathogenic nonsense mutations.

Nonsense mutations - the underlying cause of approximately 11% of all genetic diseases - prematurely terminate protein synthesis by mutating a sense codon to a premature stop or termination codon (PTC). An emerging therapeutic strategy to suppress nonsense defects is to engineer sense-codon decoding tRNAs to readthrough and restore translation at PTCs. However, the readthrough efficiency of the engineered suppressor tRNAs (sup-tRNAs) largely varies in a tissue- and sequence context-dependent manner and has not yet yielded optimal clinical efficacy for many nonsense mutations. Here, we systematically analyze the suppression efficacy at various pathogenic nonsense mutations. We discover that the translation velocity of the sequence upstream of PTCs modulates the sup-tRNA readthrough efficacy. The PTCs most refractory to suppression are embedded in a sequence context translated with an abrupt reversal of the translation speed leading to ribosomal collisions. Moreover, modeling translation velocity using Ribo-seq data can accurately predict the suppression efficacy at PTCs. These results reveal previously unknown molecular signatures contributing to genotype-phenotype relationships and treatment-response heterogeneity, and provide the framework for the development of personalized tRNA-based gene therapies.

Effectiveness of self-financed rotavirus vaccines on acute gastroenteritis primary care episodes using real-world data in Spain: a propensity score-matched analysis of cohort study.

The objective of this study was to estimate, by a novel spatiotemporal approach in an environment of non-funded rotavirus (RV) vaccines, the RV vaccine effectiveness (VE) to prevent acute gastroenteritis primary care (AGE-PC)-attended episodes, demonstrating how indirect protection leads to underestimation of direct VE under high vaccine coverage (VC). This population-based retrospective cohort study used electronic healthcare registries including all children 2 months-5 years old, born from 2009 to 2018 in the Valencia Region (Spain). Direct RV VE preventing AGE-PC episodes was estimated using propensity score matching and Poisson regressions stratified by VC, adjusted by age and calendar season. Indirect VE was estimated by Poisson regression comparing AGE-PC rates in unvaccinated children among the different VC levels. A total of 563,442 children were included for the RV VC estimation; of them, 360,576 were included in the birth-cohort for VE analysis. RV VC showed strong variability among districts and seasons, rising on average from 21% in 2009/2010 to 55% in 2017/2018. The highest direct VE was found in vaccinated children from districts with 0-30% RV VC (16.4%) and the lowest in those from districts with ≥ 70% RV VC (9.7%). The indirect protection in unvaccinated children raised from 6 to 16.6% for those living with 20-30% and ≥ 70% VC, respectively. CONCLUSION: Considering that RV is the causative agent in 20% of AGE cases, a direct effectiveness of 82% preventing AGE-PC episodes due to RV could be deduced using a novel spatiotemporal approach. A reduction of 17% of AGE-PC episodes in unvaccinated was observed in areas with VC over 70% because of indirect protection. WHAT IS KNOWN: • The effectiveness of RV vaccines preventing hospitalizations due to RV-acute gastroenteritis (RV-AGE) has been extensively studied. However, RV also burdens the primary care (PC) setting, and data on vaccine effectiveness (VE) in preventing AGE-PC visits are scarce. • The RV vaccine distribution in Spain (non-funded), with large differences in vaccine coverage (VC) among healthcare districts, provides an ideal scenario to assess the actual VE in preventing AGE-PC consultations, including the direct and indirect protection. WHAT IS NEW: • A direct effectiveness of 82% preventing AGE-PC episodes due to RV could be deduced using a novel spatiotemporal approach. A reduction of 17% of AGE-PC episodes in unvaccinated was observed in areas with high VC because of indirect protection. • These findings, together with existing data on the impact on hospitalizations due to RV-AGE, offer valuable insights for implementing vaccination initiatives in countries that have not yet commenced such programs.

Safety of fluoroquinolones / Seguridad de las fluoroquinolonas

Fluoroquinolones (FQs) are one of the most commonly prescribed classes of antibiotics. Although they were initially well tolerated in randomized clinical trials, subsequent epidemiological studies have reported an increased risk of threatening, severe, long-lasting, disabling and irreversible adverse effects (AEs), related to neurotoxicity and collagen degradation, such as tendonitis, Achilles tendon rupture, aortic aneurysm, and retinal detachment. This article reviews the main potentially threatening AEs, the alarms issued by regulatory agencies and therapeutic alternatives. (AU)

Las fluoroquinolonas son una de las clases de antibióticos más prescritas. Aunque inicialmente fueron bien toleradas en ensayos clínicos aleatorizados, estudios epidemiológicos posteriores han informado de un mayor riesgo de efectos adversos efectos adversos amenazantes, graves, duraderos, incapacitantes e irreversibles, relacionados con la neurotoxicidad y la degradación del colágeno, como tendinitis, rotura del tendón de Aquiles, aneurisma aórtico y desprendimiento de retina. Este artículo repasa los principales efectos adversos potencialmente amenazadores, las alarmas emitidas por las agencias reguladoras y las alternativas terapéuticas. (AU)

Carbon Material-Reinforced Polymer Composites for Bipolar Plates in Polymer Electrolyte Membrane Fuel Cells.

Bipolar plates (BPs) are one of the most important components of polymer electrolyte membrane fuel cells (PEMFCs) because of their important role in gas and water management, electrical performance, and mechanical stability. Therefore, promising materials for use as BPs should meet several technical targets established by the United States Department of Energy (DOE). Thus far, in the literature, many materials have been reported for possible applications in BPs. Of these, polymer composites reinforced with carbon allotropes are one of the most prominent. Therefore, in this review article, we present the progress and critical analysis on the use of carbon material-reinforced polymer composites as BPs materials in PEMFCs. Based on this review, it is observed that numerous polymer composites reinforced with carbon allotropes have been produced in the literature, and most of the composites synthesized and characterized for their possible application in BPs meet the DOE requirements. However, these composites can still be improved before their use for BPs in PEMFCs.

Microbial Ecology of Granular Biofilm Technologies for Wastewater Treatment: A Review.

Nowadays, the discharge of wastewater is a global concern due to the damage caused to human and environmental health. Wastewater treatment has progressed to provide environmentally and economically sustainable technologies. The biological treatment of wastewater is one of the fundamental bases of this field, and the employment of new technologies based on granular biofilm systems is demonstrating success in tackling the environmental issues derived from the discharge of wastewater. The granular-conforming microorganisms must be evaluated as functional entities because their activities and functions for removing pollutants are interconnected with the surrounding microbiota. The deep knowledge of microbial communities allows for the improvement in system operation, as the proliferation of microorganisms in charge of metabolic roles could be modified by adjustments to operational conditions. This is why engineering must consider the intrinsic microbiological aspects of biological wastewater treatment systems to obtain the most effective performance. This review provides an extensive view of the microbial ecology of biological wastewater treatment technologies based on granular biofilms for mitigating water pollution.

Incidence of Invasive and Noninvasive Pneumococcal Pneumonia Hospitalizations in People Aged ≥50 Years: Assessing Variability Across Denmark and Spain.

Determining pneumococcal pneumonia (PP) burden in the elderly population is challenging due to limited data on invasive PP (IPP) and, in particular, noninvasive PP (NIPP) incidence. Using retrospective cohorts of adults aged ≥50 years in Denmark (2 782 303) and the Valencia region, Spain (2 283 344), we found higher IPP hospitalization rates in Denmark than Valencia (18.3 vs 9/100 000 person-years [PY], respectively). Conversely, NIPP hospitalization rates were higher in Valencia (48.2 vs 7.2/100 000 PY). IPP and NIPP rates increased with age and comorbidities in both regions, with variations by sex and case characteristics (eg, complications, mortality). The burden of PP in adults is substantial, yet its true magnitude remains elusive. Discrepancies in clinical practices impede international comparisons; for instance, Valencia employed a higher frequency of urinary antigen tests compared to Denmark. Additionally, coding practices and prehospital antibiotic utilization may further influence these variations. These findings could guide policymakers and enhance the understanding of international disparities in disease burden assessments.

Association of Baseline Pre-Diagnosis and Post-Diagnosis Obesity and Weight Change with Cardiovascular Risk and Survival Among Nonmetastatic Prostate Cancer Survivors.

INTRODUCTION: Obesity in prostate cancer survivors may increase mortality. Better characterization of this effect may allow better counseling on obesity as a targetable lifestyle factor to reduce mortality in prostate cancer survivors. The purpose of this study was to determine whether pre- and post-diagnostic obesity and weight change affect all-cause mortality, cardiovascular disease specific mortality, and prostate cancer specific mortality in patients with nonmetastatic prostate cancer. PATIENTS AND METHODS: We performed a retrospective cohort analysis of 5,077 patients diagnosed with localized prostate cancer from 1997 to 2017 with median follow-up of 15.5 years. The Utah Population Database linked to the Utah Cancer Registry was used to identify patients at a variety of treatment centers. RESULTS: Pre-diagnosis obesity was associated with a 62% increased risk of cardiovascular disease specific mortality and a 34% increased risk of all-cause mortality (HR 1.62, 95% CI 1.05-2.50; HR 1.34, 95% CI 1.07-1.67, respectively). Post-diagnosis obesity increased the risk of cardiovascular disease specific mortality (HR 1.83, 95% CI 1.31-2.56) and all-cause mortality (HR 1.37, 95% CI 1.16-1.64) relative to non-obese men. We found no association between pre-diagnostic obesity or post-diagnostic weight gain and prostate cancer specific mortality. CONCLUSION: Our study strengthens the conclusion that pre-, post-diagnostic obesity and weight gain increase cardiovascular disease and all-cause mortality but not prostate cancer specific mortality compared to healthy weight men. An increased emphasis on weight management may improve mortality for prostate cancer survivors who are obese.

[Seroprevalence of Chagas disease at the Instituto Nacional de Cardiología Ignacio Chávez from 2004 to 2010]. / Prevalencia de cardiomiopatía dilatada en pacientes seropositivos a Trypanosoma cruzi en el Instituto Nacional Cardiología Ignacio Chávez de 2004 al 2010.

Background: Different pathogens can cause dilated cardiomyopathy, one of them is Trypanosoma cruzi protozoan. T.cruzi-chronic infection causes chronic Chagasic cardiomyopathy and affects the sinus node and the conduction systembelow the bundle of His; besides, it shows excellent arrhythmogenic potential because of ventricular arrhythmias. Knowingthe clinical characteristics and performing serological tests to diagnose chronic Chagasic cardiomyopathy is essential. The serological diagnosis for searching the antibodies is based on the phase, which can be a predictor for the development of dilated cardiomyopathy. Objectives: In this work, the objective was to describe the frequency of dilated cardiomyopathy in patients with T. cruzi positive serology. Method: A total of 961 patients who were medically and clinically diagnosed with dilated cardiomyopathy were studied. Of these, 128 were diagnosed with chronic Chagasic cardiomyopathy and had positive serology for T. cruzi with two serological tests. Results: The clinical findings were obtained from the results of the electrocardiograms and were taken from the patient's clinical histories. Conclusion: In conclusion, complete blockage of the right branch of the bundle of His (44.2%) is one of the primary conduction disorders in the patients studied. Regarding seroprevalence, 14% of patients diagnosed with dilated cardiomyopathy had anti-T. cruzi antibodies.

Antecedentes: La cardiomiopatía dilatada puede ser causada por diferentes patógenos y uno de ellos es el protozoario Trypanosoma cruzi. La infección crónica causa la cardiomiopatía chagásica crónica, que afecta el nódulo sinusal y el sistema de conducción a nivel del haz de His; además, muestra gran potencial arritmogénico, ya que frecuentemente se presentan arritmias ventriculares. Para diagnosticar la cardiomiopatía chagásica crónica es indispensable conocer las características clínicas y realizar los ensayos serológicos. El diagnóstico serológico para la búsqueda de anticuerpos se basa en la fase de la enfermedad en la que se encuentre el individuo, los cuales pueden ser un predictor para el desarrollo de la cardiomiopatía dilatada. Objetivo: El objetivo de nuestro trabajo fue describir la frecuencia de cardiomiopatía dilatada en pacientes con serología positiva a T. cruzi en el Instituto Nacional de Cardiología Ignacio Chávez. Método: Se estudiaron 961 pacientes que fueron diagnosticados médica y clínicamente con cardiomiopatía dilatada y, de estos, 128 fueron diagnosticados con cardiomiopatía chagásica crónica, los cuales presentaban serología positiva a T. cruzi con dos pruebas serológicas. Resultados: Los hallazgos clínicos se obtuvieron de los resultados de los electrocardiogramas y fueron tomados de las historias clínicas de los pacientes. Conclusiones: En conclusión, el bloqueo completo de la rama derecha del haz de His (44.2%) es una de las principales alteraciones de la conducción en los pacientes estudiados. Con respecto a la seroprevalencia, el 14% de los pacientes con diagnóstico de cardiomiopatía dilatada tuvieron anticuerpos anti-T. cruzi.

Substituting Poly(ethylene glycol) Lipids with Poly(2-ethyl-2-oxazoline) Lipids Improves Lipid Nanoparticle Repeat Dosing.

Poly(ethylene glycol) (PEG)-lipids are used in Food-and-Drug-Administration-approved lipid nanoparticle (LNP)-RNA drugs, which are safe and effective. However, it is reported that PEG-lipids may also contribute to accelerated blood clearance and rare cases of hypersensitivity; this highlights the utility of exploring PEG-lipid alternatives. Here, it is shown that LNPs containing poly(2-ethyl-2-oxazoline) (PEOZ)-lipids can deliver messenger RNA (mRNA) to multiple cell types in mice inside and outside the liver. In addition, it is reported that LNPs formulated with PEOZ-lipids show reduced clearance from the bloodstream and lower levels of antistealth lipid immunoglobulin Ms than LNPs formulated with PEG-lipids. These data justify further exploration of PEOZ-lipids as alternatives to PEG-lipids in LNP-RNA formulations.

Risk of cardiovascular events after influenza: A population-based Self Controlled Case Series study, Spain 2011-2018.

This study explores the relationship between influenza infection, both clinically diagnosed in primary-care and laboratory confirmed in hospital, and atherothrombotic events (acute myocardial infarction and ischemic stroke) in Spain. A population-based self-controlled case series design was used with individual-level data from electronic registries (n = 2,230,015). The risk of atherothrombotic events in subjects ≥50 years old increased more than 2-fold during the 14 days after the mildest influenza cases in patients with fewer risk factors and more than 4-fold after severe cases in the most vulnerable patients, remaining in them more than 2-fold for 2 months. The transient increase of the association, its gradient after influenza infection and the demonstration by 4 different sensitivity analyses provide further evidence supporting causality. This work reinforces the official recommendations for influenza prevention in at-risk groups and should also increase the awareness of even milder influenza infection and its possible complications in the general population.

Early estimates of nirsevimab immunoprophylaxis effectiveness against hospital admission for respiratory syncytial virus lower respiratory tract infections in infants, Spain, October 2023 to January 2024.

The monoclonal antibody nirsevimab was at least 70% effective in preventing hospitalisations in infants with lower respiratory tract infections (LRTI) positive for respiratory syncytial virus (RSV) in Spain (Oct 2023-Jan 2024), where a universal immunisation programme began late September (coverage range: 79-99%). High protection was confirmed by two methodological designs (screening and test-negative) in a multicentre active surveillance in nine hospitals in three regions. No protection against RSV-negative LRTI-hospitalisations was shown. These interim results could guide public-health decision-making.

Partial volume correction in longitudinal tau PET studies: is it really needed?

BACKGROUND: [18F]flortaucipir (FTP) tau PET quantification is known to be affected by non-specific binding in off-target regions. Although partial volume correction (PVC) techniques partially account for this effect, their inclusion may also introduce noise and variability into the quantification process. While the impact of these effects has been studied in cross-sectional designs, the benefits and drawbacks of PVC on longitudinal FTP studies is still under scrutiny. The aim of this work was to study the performance of the most common PVC techniques for longitudinal FTP imaging. METHODS: A cohort of 247 individuals from the Alzheimer's Disease Neuroimaging Initiative with concurrent baseline FTP-PET, amyloid-beta (Aß) PET and structural MRI, as well as with follow-up FTP-PET and MRI were included in the study. FTP-PET scans were corrected for partial volume effects using Meltzer's, a simple and popular analytical PVC, and both the region-based voxel-wise (RBV) and the iterative Yang (iY) corrections. FTP SUVR values and their longitudinal rates of change were calculated for regions of interest (ROI) corresponding to Braak Areas I-VI, for a temporal meta-ROI and for regions typically displaying off-target FTP binding (caudate, putamen, pallidum, thalamus, choroid plexus, hemispheric white matter, cerebellar white matter, and cerebrospinal fluid). The longitudinal correlation between binding in off-target and target ROIs was analysed for the different PVCs. Additionally, group differences in longitudinal FTP SUVR rates of change between Aß-negative (A-) and Aß-positive (A+), and between cognitively unimpaired (CU) and cognitively impaired (CI) individuals, were studied. Finally, we compared the ability of different partial-volume-corrected baseline FTP SUVRs to predict longitudinal brain atrophy and cognitive decline. RESULTS: Among off-target ROIs, hemispheric white matter showed the highest correlation with longitudinal FTP SUVR rates from cortical target ROIs (R2=0.28-0.82), with CSF coming in second (R2=0.28-0.42). Application of voxel-wise PVC techniques minimized this correlation, with RBV performing best (R2=0.00-0.07 for hemispheric white matter). PVC also increased group differences between CU and CI individuals in FTP SUVR rates of change across all target regions, with RBV again performing best (No PVC: Cohen's d = 0.26-0.66; RBV: Cohen's d = 0.43-0.74). These improvements were not observed for differentiating A- from A+ groups. Additionally, voxel-wise PVC techniques strengthened the correlation between baseline FTP SUVR and longitudinal grey matter atrophy and cognitive decline. CONCLUSION: Quantification of longitudinal FTP SUVR rates of change is affected by signal from off-target regions, especially the hemispheric white matter and the CSF. Voxel-wise PVC techniques significantly reduce this effect. PVC provided a significant but modest benefit for tasks involving the measurement of group-level longitudinal differences. These findings are particularly relevant for the estimations of sample sizes and analysis methodologies of longitudinal group studies.

Perturbative computation of nonlinear harvesting through a path integral approach.

Statistical field theories provide powerful tools to study complex dynamical systems. In this work those tools are used to analyze the dynamics of a kinetic energy harvester, which is modeled by a system of coupled stochastic nonlinear differential equations and driven by colored noise. Using the Martin-Siggia-Rose response fields we analytically approach the problem through path integrals in the phase space and represent the moments that correspond to physical observables through Feynman diagrams. This analysis method is tested by comparing the solution to the linear case with previous analytical results. Through a perturbative expansion it is calculated how the nonlinearity affects, to the first order, the energy harvest supporting the results through numerical simulations.

Skeletal muscle and visceral adipose radiodensities are pre-surgical, non-invasive markers of aggressive kidney cancer.

INTRODUCTION: Most studies on body composition in kidney cancer have been conducted among patients with metastatic disease. Given that aggressive tumours can adversely impact body composition and even non-metastatic tumours can be aggressive, we evaluated associations between pre-surgical body composition features and tumour pathological features in patients with non-metastatic clear cell renal cell cancer (ccRCC). METHODS: The Resolve Cohort consists of 1239 patients with non-metastatic ccRCC who underwent nephrectomy at Memorial Sloan Kettering Cancer Center between 2000 and 2020. The cross-sectional areas and radiodensities of skeletal muscle, visceral adipose, and subcutaneous adipose tissues were determined from pre-surgical computed tomography (CT) scans at the third lumbar vertebrae using Automatica software. Pearson's correlation coefficients describe inter-relationships among BMI and body composition variables, while odds ratios (OR) and 95% confidence intervals (CI) estimate associations between continuous body composition features (per 1-standard deviation) and advanced stage (Stage III vs. Stages I-II) and high Fuhrman grade (Grades 3-4 vs. 1-2) from multivariable logistic regression models that considered the potential impact of biological sex, contrast enhanced CTs, and early age at onset of ccRCC. RESULTS: The cohort was predominantly male (69%), white (89%), and had a median age of 58. The proportion of patients presenting with advanced stage and high-grade disease were 31% and 51%, respectively. In models that adjusted for demographics and all body composition variables simultaneously, decreasing skeletal muscle radiodensity (i.e., more fat infiltration) but increasing visceral adipose tissue radiodensity (i.e., more lipid depletion) were associated with advanced tumour features. Per 8.4 HU decrease in skeletal muscle radiodensity, the odds of presenting with advanced stage was 1.61 (95% CI: 1.34-1.93). Per 7.22 HU increase in visceral adipose tissue radiodensity, the odds of presenting with advanced stage was 1.45 (95% CI: 1.22-1.74). Skeletal muscle index (i.e., sarcopenia) was not associated with either tumour feature. Similar associations were observed for Fuhrman grade, a more direct marker of tumour aggressiveness. Associations did not differ by sex, contrast use, or age at onset of ccRCC. CONCLUSIONS: Lipid infiltrated skeletal muscle, but lipid depleted visceral adipose tissue were independently associated with advanced tumour features in non-metastatic ccRCC. Findings highlight the importance of evaluating the full range of body composition features simultaneously in multivariable models. Interpreting pre-surgical CTs for body composition for patients may be a novel and non-invasive way to identify patients with aggressive renal tumours, which is clinically relevant as renal biopsies are not routinely performed.