Do Seasonal Glucocorticoid Changes Depend on Reproductive Investment? A Comparative Approach in Birds

Animals go through different life history stages such as reproduction, moult, or migration, of which some are more energy-demanding than others. Baseline concentrations of glucocorticoid hormones increase during moderate, predictable challenges and thus are expected to be higher when seasonal energy demands increase, such as during reproduction. By contrast, stress-induced glucocorticoids prioritize a survival mode that includes reproductive inhibition. Thus, many species down-regulate stress-induced glucocorticoid concentrations during the breeding season. Interspecific variation in glucocorticoid levels during reproduction has been successfully mapped onto reproductive investment, with species investing strongly in current reproduction (fast pace of life) showing higher baseline and lower stress-induced glucocorticoid concentrations than species that prioritize future reproduction over current attempts (slow pace of life). Here we test the >glucocorticoid seasonal plasticity hypothesis>, in which we propose that interspecific variation in seasonal changes in glucocorticoid concentrations from the non-breeding to the breeding season will be related to the degree of reproductive investment (and thus pace of life). We extracted population means for baseline (for 54 species) and stress-induced glucocorticoids (for 32 species) for the breeding and the non-breeding seasons from the database >HormoneBase>, also calculating seasonal glucocorticoid changes. We focused on birds because this group offered the largest sample size. Using phylogenetic comparative methods, we first showed that species differed consistently in both average glucocorticoid concentrations and their changes between the two seasons, while controlling for sex, latitude, and hemisphere. Second, as predicted seasonal changes in baseline glucocorticoids were explained by clutch size (our proxy for reproductive investment), with species laying larger clutches showing a greater increase during the breeding season-especially in passerine species. In contrast, changes in seasonal stress-induced levels were not explained by clutch size, but sample sizes were more limited. Our findings highlight that seasonal changes in baseline glucocorticoids are associated with a species' reproductive investment, representing an overlooked physiological trait that may underlie the pace of life

Monthly sunspot number time series analysis and its modeling through autoregressive artificial neural network

This study reports a statistical analysis of monthly sunspot number time series and observes non homogeneity and asymmetry within it. Using Mann-Kendall test a linear trend is revealed. After identifying stationarity within the time series we generate autoregressive AR(p) and autoregressive moving average (ARMA(p,q)). Based on minimization of AIC we find 3 and 1 as the best values of p and q respectively. In the next phase, autoregressive neural network (AR-NN(3)) is generated by training a generalized feedforward neural network (GFNN). Assessing the model performances by means of Willmott's index of second order and coefficient of determination, the performance of AR-NN(3) is identified to be better than AR(3) and ARMA(3,1).Comment: 17 pages, 4 figure

Pseudorabies Virus Infection Alters Neuronal Activity and Connectivity In Vitro

Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV), infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP) firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural function seen in PRV-infected animals

The seventh blind test of crystal structure prediction: structure ranking methods

\ua9 2024 International Union of Crystallography. All rights reserved. A seventh blind test of crystal structure prediction has been organized by the Cambridge Crystallographic Data Centre. The results are presented in two parts, with this second part focusing on methods for ranking crystal structures in order of stability. The exercise involved standardized sets of structures seeded from a range of structure generation methods. Participants from 22 groups applied several periodic DFT-D methods, machine learned potentials, force fields derived from empirical data or quantum chemical calculations, and various combinations of the above. In addition, one non-energy-based scoring function was used. Results showed that periodic DFT-D methods overall agreed with experimental data within expected error margins, while one machine learned model, applying system-specific AIMnet potentials, agreed with experiment in many cases demonstrating promise as an efficient alternative to DFT-based methods. For target XXXII, a consensus was reached across periodic DFT methods, with consistently high predicted energies of experimental forms relative to the global minimum (above 4 kJ mol- 1 at both low and ambient temperatures) suggesting a more stable polymorph is likely not yet observed. The calculation of free energies at ambient temperatures offered improvement of predictions only in some cases (for targets XXVII and XXXI). Several avenues for future research have been suggested, highlighting the need for greater efficiency considering the vast amounts of resources utilized in many cases

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

Endurance and sprint training affect immune function differently in green anole lizards (<i>Anolis carolinensis</i>)

Limited resources must be partitioned among traits that enhance fitness. Although survival-related traits often trade off with reproduction, survival-related traits themselves may trade off with each other under energy limitation. Whole-organism performance and the immune system both enhance survival, yet are costly, but it is unclear how the two might trade off with each other under energy-limited conditions. Resources may be allocated to very different types of performance (e.g., aerobic endurance versus anaerobic sprinting) just as they may be allocated to different components of the immune system (e.g., innate versus acquired) to maximize survival. We forced allocation to different performance traits in green anole lizards (Anolis carolinensis), using specialized exercise training, to determine how different components of the immune system would be impacted by shifts in energy use. We measured immunocompetence in endurance trained, sprint trained, and untrained control lizards with the swelling response to phytohemagglutinin (cell-mediated), antibody response to sheep red blood cells (acquired humoral), and wound healing (integrated). Endurance-trained lizards had reduced cell-mediated immunity, whereas sprint-trained lizards had reduced rates of wound healing. The acquired immune response was not affected by either type of training. Because each immune measure responded differently to the different types of training, our results do not support the hypothesis that simple energy limitation determines overall investment in immunity. Instead, different components of the immune system appear to be affected in ways specific to how energy is invested in performance.</jats:p

R136K fibroblast growth factor-1 mutant induces heparin-independent migration of endothelial cells through fibrin glue

AbstractObjectives: R136K is a mutation of fibroblast growth factor-1 (FGF-1) in which arginine replaces lysine at the primary thrombin cleavage site. This may be important in vivo in inducing endothelial cell (EC) migration and coverage of arterial injury sites by allowing R136K to be used in a fibrin glue delivery system, without thrombin-induced degradation, in the absence of heparin. The objectives of this study were to determine whether R136K, with and without heparin, can induce migration of EC and smooth muscle cells (SMC) through fibrin glue, and to compare these results with those of wild-type FGF-1; and to determine the resistance of R136K to thrombin-induced degradation versus FGF-1. Methods: The dose-response migration through fibrin glue induced by wild-type FGF-1 and the R136K mutant in the presence and absence of heparin was tested with EC and SMC. Migration was tested with 50, 100, and 200 ng/mL of both FGF-1 and R136K, either with or without 5 U/mL of heparin. Migration of EC was also assessed after growth inhibition with mitomycin C. A novel modified Boyden chamber-type migration assay using fibrin glue on the upper surface of the chamber filter was used to test migration. The fluorescent marker calcein was used to identify those cells that had migrated through the fibrin glue and were embedded in the filter. Molecular degradation by thrombin was assessed with sodium dodecylsulfate polyacrylamide gel electrophoresis. Results: For EC, R136K in the absence of heparin induced significantly more migration than did FGF-1 at 50 (P <.002), 100 (P <.0001), and 200 (P <.0001) ng/mL. In the presence of heparin, a chemotactic response of EC to cytokine was seen at all doses, with no significant difference between FGF-1 and R136K. A dose-dependent difference was noted in this group between the 100 and 200 ng/mL concentrations of cytokine (for FGF-1, P <.0001; for R136K, P <.0001). SMC showed no difference in migration with FGF-1, R136K, or negative control at any dose in the presence or absence of heparin. Gel electrophoresis demonstrated that R136K was more resistant to thrombin degradation than was FGF-1. Conclusion: Site-directed mutagenesis of FGF-1 to R136K enables induction of heparin-independent migration of EC through fibrin glue at an optimal concentration of 100 ng/mL. Neither FGF-1 nor R136K elicits SMC migration through fibrin glue. The ability of R136K to induce EC migration through fibrin glue in the absence of heparin may prove useful in vivo by inducing EC migration and coverage of arterial injury sites, thus potentially reducing thrombogenicity and intimal hyperplasia. (J Vasc Surg 2003;1075-81.

Modulation of Antigen Expression in B-Cell Precursor Acute Lymphoblastic Leukemia During Induction Therapy is Partly Transient: Evidence for a Drug-Induced Regulatory Phenomenon. Results of the AIEOP-BFM-ALL-FLOW-MRD-Study Group

BACKGROUND: Changes of antigen expression on residual blast cells of acute lymphoblastic leukemia (ALL) occur during induction treatment. Many markers used for phenotyping and minimal residual disease (MRD) monitoring are affected. Glucocorticoid (GC)-induced expression modulation has been causally suspected, however, subclone selection may also cause the phenomenon. METHODS: We investigated this by following the phenotypic evolution of leukemic cells with flow cytometry from diagnosis to four time points during and after GC containing chemotherapy in the 20 (of 360 consecutive) B-cell precursor patients with ALL who had persistent MRD throughout. RESULTS: The early expression changes of CD10 and CD34 were reversible after stop of GC containing chemotherapy. Modulation of CD20 and CD45 occurred mostly during the GC phase, whereas CD11a also changed later on. Blast cells at diagnosis falling into gates designed according to "shifted" phenotypes from follow-up did not form clusters and were frequently less numerous than later on. CONCLUSIONS: Our data support the idea that drug-induced modulation rather than selection causes the phenomenon. The good message for MRD assessment is that modulation is transient in at least two (CD10 and CD34) of the five prominent antigens investigated and reverts to initial aberrant patterns after stop of GC therapy, whereas CD20 expression gains new aberrations exploitable for MRD detection

Clinical features and outcomes of COVID-19 despite SARS-CoV-2 vaccination in people with multiple sclerosis

Background Several studies have demonstrated reduced serological response to vaccines in patients treated with anti-CD20 agents. However, limited data exist surrounding the clinical effect of disease modifying therapy (DMT) use on vaccine efficacy. Objectives To investigate breakthrough coronavirus disease 2019 (COVID-19) in vaccinated people with multiple sclerosis (PwMS) on DMT. Methods PwMS on DMT diagnosed with COVID-19 after full vaccination were identified from an existing Cleveland Clinic COVID-19 registry, supplemented by provider-identified cases. Demographics, disease history, DMTs, comorbidities, exposures, vaccination status, and COVID-19 outcomes were confirmed by review of the electronic medical record. Results Thirteen (3.8%) of 344 fully vaccinated people with multiple sclerosis on disease modifying therapy were diagnosed with COVID-19 after vaccination. Ten patients (76.9%) were on an anti-CD20 therapy, the remaining 3 (23.1%) on fingolimod. Only 2 patients (15.4%), both on anti-CD20 therapy, required hospitalization and steroid treatment. Neither required Intensive Care Unit admission. Conclusion Patients treated with anti-CD20 agents and sphingosine 1-phosphate receptor modulators may still be at risk for COVID-19 despite vaccination. While still at risk for hospitalization, intubation and death from COVID-19 appear rare. Larger studies analyzing how this may differ in the setting of emerging variants are needed. </jats:sec