Physiological Stress Research Articles

Genome-Wide Characterization of Class III Peroxidases and Their Expression Profile During Mycorrhizal Symbiosis and Phosphorus Deprivation in Lettuce (Lactuca sativa L.)

Lettuce cultivation requires high fertilizer inputs, which impact the environment and costs. Arbuscular mycorrhizal symbiosis (AMS) can reduce fertilizer use, enhance plant nutrition (especially phosphorus), and promote healthier plants. Class III peroxidases (PRXs) play crucial roles in various physiological processes and stress responses. However, their role in AMS and phosphorous (P) deficiency is still unclear. Our study identified 91 PRX genes in the lettuce genome (LsPRXs) and clustered them into eight subfamilies based on phylogenetic relationships. Evolutionary analysis indicated that tandem duplication was the main driver for LsPRX gene family expansion. Synteny analysis showed orthologous relationships of the PRX gene family between lettuce and potato, Arabidopsis, and maize, identifying 39, 28, and 3 shared PRXs, respectively. Transcriptomic data revealed that most LsPRX genes were more expressed in roots than in leaves and differentially expressed LsPRXs were found in response to AMS and P supply. Notably, 15% of LsPRX genes were differentially expressed in roots during mycorrhization. Gene expression network analysis highly correlated five LsPRXs (LsPRX17, LsPRX23, LsPRX24, LsPRX64, and LsPRX79) with genes involved in cell wall remodeling and reorganization during mycorrhization. Our results provide insights into the evolutionary history and functional roles of PRX genes in lettuce and identify candidate gene targets that may enhance the bio-stimulant effects of AMS and help to cope with P deficiency.

Osmotic stress in roots drives lipoxygenase-dependent plastid remodeling through singlet oxygen production.

Osmotic stress, caused by the lack of water or by high salinity, is a common problem in plant roots. Osmotic stress can be reproducibly simulated with the application of solutions of the high-molecular-weight and impermeable polyethylene glycol. The accumulation of different reactive oxygen species, such as singlet oxygen, superoxide, and hydrogen peroxide, accompany this stress. Among them, singlet oxygen, produced as a byproduct of lipoxygenase activity, has been associated with limiting root growth. To better understand the source and effect of singlet oxygen, we followed its production at the cellular level in Arabidopsis (Arabidopsis thaliana). Osmotic stress initiated profound changes in plastid and vacuole structure. Confocal and electron microscopy showed that the plastids were a source of singlet oxygen accompanied by the appearance of multiple, small extraplastidic bodies that were also an intense source of singlet oxygen. A marker protein, CRUMPLED LEAF, indicated that these small bodies originated from the plastid outer membrane. Remarkably, LINOLEATE 9S-LIPOXYGENASE 5, (LOX5), was shown to change its distribution from uniformly cytoplasmic to a more clumped distribution together with plastids and the small bodies. In addition, oxylipin products of type 9 lipoxygenase increased, while products of type 13 lipoxygenases decreased. Inhibition of lipoxygenase by the SHAM inhibitor or in down-regulated lipoxygenase lines prevented cells from initiating the cellular responses, leading to cell death. In contrast, singlet oxygen scavenging halted terminal cell death. These findings underscore the reversible nature of osmotic stress-induced changes, emphasizing the pivotal roles of lipoxygenases and singlet oxygen in root stress physiology.

Past, Present, and Future of Forbs in Old-Growth Tropical and Subtropical Grasslands

Forbs are important contributors to species diversity and ecosystem functions in low-latitude grasslands, where they support diverse herbivore communities and millions of people. Native forb assemblages tolerate disturbances and physiological stressors (fire, herbivory, drought, and frost) that together have shaped their exceptional functional diversity. Yet, compared to trees and grasses, forbs have received much less attention in grassland studies until recently. Here, we review forb-centric literature to illustrate that land conversion and responsible management of fire and herbivory are crucial to maintaining forb diversity. Management practices promoting forb diversity offer (a) high-quality food items and medicinal resources that support rural livelihoods and animal diversity (from wild ungulates and livestock to fossorial rodents and insects), including their adaptive foraging patterns, and (b) carbon and nutrient inputs that regulate belowground processes. Improved understanding of the above- and belowground regeneration strategies of forbs is critical for restoration and conservation to secure their services in future old-growth tropical and subtropical grasslands.

Measuring Socioeconomic and Stress Disparities in Infant Declarative Memory Using the Visual Paired Comparison Task.

Research suggests that socioeconomic circumstances and stress predict memory skills in adults and older children, yet few studies have addressed this question in infancy. The current study used the visual-paired comparison paradigm to examine whether socioeconomic circumstances, maternal perceived stress, and/or maternal physiological stress, all measured prenatally, predict memory performance among 6-month-old infants. We found no significant associations between infant memory and any measure of socioeconomic circumstance or stress. Potential explanations for these null findings are discussed.

Accentuated Eccentric Loading and Alternative Set Structures: A Narrative Review for Potential Synergies in Resistance Training.

Chae, S, McDowell, KW, Baur, ML, Long, SA, Tufano, JJ, and Stone, MH. Accentuated eccentric loading and alternative set structures: A narrative review for potential synergies in resistance training. J Strength Cond Res 38(11): 1987-2000, 2024-As athletes become adapted to training over time, it becomes more difficult to develop their strength and power. In a conventional resistance training strategy, volume or load may be increased to provide novel stimuli to break through a plateau. However, physiological stress markers increase with increased volume or load, which is an innate shortcoming. In that case, practitioners strive to develop unconventional strategies that could increase training stimuli while adjusting fatigue. Two programming tactics, accentuated eccentric loading (AEL) using eccentric overload and alternative set structures (AS) using intraset rests, have been reported to increase training stimuli and alleviate fatigue, respectively. Importantly, when merging AEL and AS in various contexts, the 2 benefits could be accomplished together. Because AEL and AS cause different outcomes, it is important to deal with when and how they may be integrated into periodization. Moreover, prescribing eccentric overload and intraset rests requires logistical considerations that need to be addressed. This review discusses the scientific and practical aspects of AEL and AS to further optimize strength and power adaptations. This review discusses (a) scientific evidence as to which tactic is effective for a certain block, (b) potential practical applications, and (c) related discussions and future research directions.

No Effects of Omega-3 Supplementation on Kynurenine Pathway, Inflammation, Depressive Symptoms, and Stress Response in Males: A Placebo-Controlled Trial

Background: Increased inflammation and heightened physiological stress reactivity have been associated with pathophysiology of depressive symptoms. The underlying biological mechanisms by which inflammation and stress may influence neurogenesis are changes in the kynurenine (KYN) pathway, which is activated under stress. Supplementation with n-3 polyunsaturated fatty acids (n-3 PUFAs) has anti-inflammatory properties and can increase stress resilience. Whether n-3 PUFAs alter KYN stress response is unknown. Objectives: This placebo-controlled study investigated the effect of n-3 PUFAs on KYN metabolism, inflammation, depressive symptoms, and mood. Moreover, stress-induced changes following a laboratory stressor have been assessed. Methods: In this placebo-controlled study, 47 healthy male adults received either 4g n-3 PUFAs per day (Omega-3 group) or a placebo (Placebo group) for 12 weeks. Results: A significant group-by-time interaction was found for the inflammatory markers gp130 (F = 7.07, p = 0.011), IL-6R alpha (F = 10.33, p = 0.003), and TNF_RI (F= 10.92, p = 0.002). No significant group-by-time interactions were found for KYN metabolites, depressive symptoms, and mood (except for Hedonic tone (F = 6.50, p = 0.014)), nor for stress-induced changes in KYN metabolites and mood following a laboratory stressor. Conclusions: Overall, increased n-3 PUFA levels in healthy men ameliorate inflammatory markers but do not ameliorate KYN metabolism, depressive symptoms, mood, or KYN metabolism and mood following a stress induction. This study was registered at ClinicalTrials.gov with the identifier NCT05520437 (30/08/2022 first trial registration).

Prenatal exposure to synthetic chemicals in relation to HPA Axis activity: A systematic review of the epidemiological literature.

Pregnant people are widely exposed to numerous synthetic chemicals with known endocrine-disrupting properties (e.g., phthalates, phenols, per- and poly-fluoroalkyl substances (PFAS)). To date, most epidemiological research on how endocrine-disrupting chemicals (EDCs) disrupt hormone pathways has focused on estrogens, androgens, and thyroid hormones. Far less research has examined the impact of EDCs on the hypothalamic-pituitary-adrenal (HPA) axis, despite its central role in the physiologic stress response and metabolic function. To systematically review the epidemiological literature on prenatal synthetic EDC exposures in relation to HPA axis hormones (e.g., corticotropin-releasing hormone, adrenocorticotropic hormone, cortisol, cortisone) in pregnant people and their offspring. A literature search of PubMed, Scopus, and Embase was conducted. Primary research studies were selected for inclusion by two independent reviewers and risk of bias was assessed using the Office of Health Assessment and Translation guidelines established by the National Toxicology Program with customization for the specific research topic. Data were extracted from each study and included in a qualitative synthesis. 22 published studies met the inclusion criteria. Phthalates were the most prevalent EDC studied, followed by PFAS, phenols, and parabens, with fewer studies considering other synthetic chemicals. Offspring glucocorticoids were the most commonly considered outcome, followed by maternal glucocorticoids and placental corticotropin-releasing hormone. There was considerable heterogeneity in methods across studies, particularly in HPA axis outcome measures and matrices, making cross-study comparisons challenging. Numerous studies suggested disruption of HPA axis hormones and sex differences in association, but results varied considerably across studies and EDC classes. The limited literature to date suggests the HPA axis may be vulnerable to disruption by synthetic EDCs. Carefully designed studies that prioritize biospecimen collection specific to HPA axis hormones are needed along with greater standardization of biospecimen collection and analysis protocols to facilitate cross-study comparisons and interpretation.

The impact of physiological state and environmental stress on bacterial load estimation methodologies for Mycobacterium tuberculosis

When processed in solid or liquid medium, tuberculosis patient samples yield different proportions of a heterogenous bacterial community over the duration of treatment. We aimed to derive a relationship between methodologies for bacterial load determination and assess the effect of the growth phase of the parent culture and its exposure to stress on the results. Mycobacterium tuberculosis H37Rv was grown with and without antibiotic (isoniazid or rifampicin) and sampled on day 0, 3, 11 and 21 of growth in broth culture. The bacterial load was estimated by colony counts and the BD BACTEC MGIT system. Linear and nonlinear mixed-effects models were used to describe the relationship between time-to-positivity (TTP) and time-to-growth (TTG) versus colony forming units (CFU), and growth units (GU) versus incubation time in MGIT. For samples with the same CFU, antibiotic-treated and stationary phase cells had a shorter TTP than antibiotic-free controls and early-logarithmic phase cells, respectively. Similarly, stationary phase samples reached higher GUs and had shorter TTG than early-log phase ones. This suggests that there is a population of bacterial cells that can be differentially recovered in liquid medium, giving us insight into the physiological states of the original culture, aiding the interpretation of clinical trial outputs.

Stress physiology of Moringa oleifera under tropospheric ozone enrichment: An ecotype-specific investigation into growth, nonstructural carbohydrates, and polyphenols.

Ozone (O3) is an oxidative pollutant that significantly threatens plant development and ecological dynamics. The present study explores the impact of O3 on Moringa (Moringa oleifera) ecotypes when exposed to ambient and elevated O3 levels. Elevated O3 concentrations resulted in significant reductions in total biomass for all ecotypes. Photosynthetic parameters, including stomatal conductance (gsto), CO2 assimilation (Pn), and carboxylation efficiency (K), decreased under elevated O3 in some ecotypes, indicating a detrimental effect on carbon assimilation. Nonstructural carbohydrate (NSC) levels in roots varied among ecotypes, with significant reductions in starch content observed under elevated O3, suggesting a potential shift towards soluble sugar accumulation and reallocation for antioxidant defense. Secondary metabolite analysis revealed increased polyphenol production, particularly quercetin derivatives, under elevated O3 in specific ecotypes, highlighting their role in mitigating oxidative stress. Interestingly, the glucosinolate content also varied, with some ecotypes exhibiting increased levels, suggesting a complex regulatory mechanism in response to O3 exposure. The study underscores the intrinsic variability among Moringa ecotypes in response to O3 stress, emphasizing the importance of genetic diversity for adaptation. The findings indicate that Moringa's metabolic plasticity, including shifts in NSC and SM production, plays a crucial role in its defense mechanisms against O3-induced oxidative stress. These insights are vital for optimizing the cultivation and utilization of Moringa in diverse environmental conditions, particularly in regions with elevated O3 levels.

How do rest-pause and sarcoplasma stimulating training models affect metabolic and psychoaffective responses in bodybuilding athletes compared to traditional training?

IntroductionStrength training (ST) is a strategy to enhance quality of life through increased strength, muscle hypertrophy, and functional capacity. Training systems are associated with manipulation of volume and intensity, generating different stimuli, such as Rest-Pause (RP) and Sarcoplasmic Stimulating Training (SST). These systems induce greater mechanical and physiological stress, leading to increased strength and muscle hypertrophy. However, the metabolic and psycho-affective effects of advanced systems in experienced practitioners remain inconclusive. The purpose of the study is to analyze the acute effects of RP, SST, and Traditional (TMS) systems on metabolic and psycho-affective responses in adult men.MethodsThis experimental crossover study assessed 15 subjects (30.38 ± 2.06 years; 88.40 ± 6.50 kg; 1.74 ± 0.07 cm) experienced in ST, evaluated under TMS, RP, and SST during flat bench press and leg press 45° exercises. Body composition, muscular strength via 1-RM testing, lactate concentration (LAC), and psycho-affective measures (Rating of Perceived Exertion-RPE; Visual Analog Scale-VAS; Feeling Scale-FS) were determined. Statistical analysis was performed using the Minitab software, with p ≤ 0.05, IC-95%).ResultsThe finals results showed SST exhibited a 38.10% lower LAC concentration post-training session compared to TMS, while RP showed 37.20% lower LAC concentration than TMS post-session. Average RPE values for RP and SST were higher (8.50 ± 1.10 and 8.60 ± 0.90, respectively) than TMS (6.00 ± 1.10). VAS displayed higher average values for RP and SST (8.00 ± 2.00 and 8.00 ± 1.00, respectively) compared to TMS (5.00 ± 1.00), with affective ratings indicating positive values for TMS and values between 0 and −5 for RP (40%) and SST (60%) post-training sessions, suggesting that RP and SST induced less affective response than TMS.DiscussionThe results lead to the conclusion that manipulation of training volume and intensity led to higher RPE and pain (VAS). The data suggest that inappropriate prescription of these systems could lead to greater displeasure, leading us to hypothesize that a higher likelihood of discontinuation from strength training programs would occur, suggesting that greater repetition volumes (RP and SST) should be targeted at individuals with a higher training level.

Comparison of Physiological Stress Indices in Anesthetized and Manually Restrained Leopard Sharks, Triakis semifasciata

Background: Leopard sharks (Triakis semifasciata) are abundant, coastal, eastern Pacific, mesopredatory sharks and are frequently managed in aquariums and zoos. Medical examinations are a routine part of good husbandry practices, but the handling protocols vary greatly between facilities. In this study, we compared the physiological stress responses of T. semifasciata associated with manual restraint and sedated handling under parallel holding and handling procedures in a 10 min interval. Methods: Blood was collected and analyzed for the hematocrit (Hct), lactate, glucose, beta-hydroxybutyrate (β-HB), pH, blood gasses, 1α-hydroxycorticosterone (1α-OHB), and corticosterone (B). Results: Overall, a minimal physiological stress response was observed in both groups. However, statistically significant increases in the PCO2, β-HB and lactate occurred, while the pHTC, SO2, and BE decreased over time in the manual-restraint group. In the sedated group, the B, PCO2, and lactate increased while the pHTC, SO2, and base excess (BE) decreased over time. When comparing treatments, the sedated group had a higher B and PCO2 TC and a lower pHTC, BE, and SO2 than the manual-restraint group at the second time point. Conclusions: This study indicates that manual restraint is comparable to the described sedation in T. semifasciata for minimally invasive procedures. The overall results show that this species had low physiological stress responses to both methods.

Activation of the general stress response sigma factor SigB prevents competence development in Bacillus subtilis.

Bacillus subtilis exhibits a large number of different specific and general adaptation reactions, which need to be well balanced to sustain survival under largely unfavorable conditions. Under specific conditions, natural competence develops, which enables B. subtilis to actively take up exogenous DNA to integrate it into its own genome. In contrast to this specific adaptation, the general stress response is induced by a variety of exogenous stress and starvation stimuli, providing comprehensive protection and enabling survival of vegetative B. subtilis cells. In the present work, we reveal the molecular basis for the interconnection of these two important responses in the regulatory network. We describe that the master regulator of the general stress response SigB is activated by physiological stress stimuli, including daylight and ethanol stress, leading to the inactivation of the competence master regulator ComK by transcriptional anti-sense regulation, showing a strict hierarchy of adaptational responses under severe stress.

Age-predicted maximal heart rate reserve as an alternative prognostic parameter in patients with heart failure with preserved ejection fraction -insights from PURSUIT-HFpEF registry-

Abstract Background Heart rate reserve (HRR), a measure of chronotropic response, is a prognostic parameter in patients with heart failure with preserved ejection fraction (HFpEF). However, exercise testing and measuring maximum heart rate (HR) are sometimes difficult in patients with heart failure with preserved ejection fraction (HFpEF). Assessing age-predicted maximal HRR (APHRR), defined as the difference between the resting HR and the age-predicted maximum HR (220 - age), would be a simple alternative to HRR. Purpose To assess the impact of APHRR at discharge on prognosis in patients with HFpEF. Methods An analysis was performed from a prospective multicenter observational registry for HFpEF (PURSUIT-HFpEF Registry) conducted in the Osaka region of Japan. A total of 1231 patients hospitalized for acute heart failure (diagnosed by using Framingham criteria) met the inclusion criteria: a left ventricular ejection fraction ≥50% and brain natriuretic peptide level ≥100 pg/ml. Excluding patients with permanent pacemakers, we enrolled 918 patients (age, 81 ± 9 years; men, 45%; atrial fibrillation, 38%) whose follow-up data after survival discharge were available. Results There was a moderate correlation between HR (median 69, interquartile range [IQR] 61-79 beats per minute [bpm]) and APHRR at discharge (71, 59-81 bpm) (r² = 0.68, p <0.001). During the median follow-up period of 23.8 months [IQR, 12.5-36.3] after discharge, 267 patients (15.4%) died, and the mortality rates incrementally decreased according to the APHRR quartiles (Q1, 44.6%; Q2, 26.6%; Q3, 26.2%; Q4, 18.4%; p <0.001). Cox regression analysis revealed that both the resting HR (hazard ratio per quartile increase, 1.16; 95% confidence interval, 1.04-1.30, p = 0.008) and APHRR (0.67; 0.60-0.75, p <0.001) were associated with mortality. However, the diagnostic accuracy was significantly superior in the APHRR than in resting HR (area under the curve; 0.628 vs. 0.552, p <0.001). Conclusions Assessment of the APHRR at discharge was a simple and useful method for risk stratification of patients with HFpEF. An incremental favorable prognosis indicated the prognostic importance of having a functional reserve during physiologic stress.

Microdosing of alteplase leads to thrombolysis in an in vitro flow model of cardiac microvascular obstruction

Abstract Background Cardiac microvascular obstruction (MVO) is a frequent injury of the myocardial microcirculation after successful recanalisation of the occluded coronary artery in myocardial infarction. At least in part, MVO is caused by embolised microthrombi of less than 200 µm diameter [1]. MVO leads to hypoperfusion of the myocardium and negatively affects patient outcomes. However, there is no effective treatment for MVO [2, 3]. Thrombolytic drugs are a promising approach, but they are difficult to deliver to the MVO area, and an increased risk of bleeding limits their use. In a previous study using an in vitro fluidic multi-scale model for MVO [4, 5], it was shown that controlled flow infusion (CFI) with a novel drug-delivering catheter could be used to effectively deliver highly concentrated intracoronary microdoses of a thrombolytic drug to the MVO area [6]. We now aim to investigate how such locally administered drug microdoses can induce thrombolysis as a possible therapeutic approach for MVO treatment. Methods A microfluidic chip (Fig.1) was used to study thrombolysis under flow using different microdoses of the thrombolytic drug alteplase. The chip consists of a tapered straight channel, which traps injected porcine microthrombi without causing complete channel occlusion (Fig. 1A). To mimic intracoronary CFI (consisting of temporary balloon occlusion of a coronary vessel for 90 seconds while drug is injected distally through a catheter) in vitro, microthrombi were incubated (without flow) directly in the chip for 90 seconds with various microdoses of alteplase (Fig. 2A, C). The chip was subsequently perfused with porcine plasma for 25 min (matched for physiological shear stress of 30 dyn/cm²). Conventional intravenous (IV) drug infusion (10 mg dose) resulting in a low systemic alteplase concentration, was mimicked by perfusing microthrombi with porcine plasma containing 2 µg/ml alteplase (Fig. 2B, C). Results Thrombolysis after CFI was concentration dependent, with the lowest microdose (0.3 mg) achieving 24% lysis of the thrombus area and the highest microdose (1.5 mg) achieving 60% lysis. In contrast, conventional IV drug infusion (corresponding to 10 mg alteplase IV dose) only achieved 10% lysis and was not significantly higher than the control perfused with pure porcine plasma. Conclusion Our findings suggest that intracoronary CFI is more efficient at achieving porcine microthrombus lysis than the current standard of IV bolus infusion (2 µg/ml alteplase in the circulating blood). Intracoronary CFI microdosing of fibrinolytic drugs using a drug-delivering catheter is a promising therapeutic approach for treating embolising MVO with a reduced systemic drug burden. Importantly, our intracoronary CFI approach achieves locally 6–40 times higher drug concentrations than a conventional IV drug infusion while reducing the total drug dose 60–300 times (Fig. 2C).

Biomechanical comparison of four isometric prosthetic ligament repair techniques for tarsal medial collateral ligament injury.

To compare the stability, ultimate strength, and isometry of 4 prosthetic ligament repairs for canine tarsal medial collateral ligament injury. 24 cadaveric canine distal hind limbs with induced medial tarsal instability were randomly divided into 4 groups. Simulated medial shearing injury of the collateral and medial malleolus were repaired using 1 of 4 isometric suture techniques: bone tunnels with nylon suture (TN), ultrahigh-molecular-weight polyethylene (UHMWPE) suture (TU), tibial bone anchor with nylon suture (AN), or talar bone anchor with UHMWPE suture (AU). Each repair was evaluated for medial stability before and after cyclic range of motion. 3 of 4 repair configurations allowed string potentiometer isometry data collection during cyclic range of motion. Each construct was subsequently tested to failure; the strength and failure mode were recorded. All repair groups showed statistically increased laxity compared to intact ligament. There was no difference in joint laxity between repair techniques. Cyclic range-of-motion testing did not increase joint laxity at any tested joint angle. Strength to failure was no different between repair groups. Isometry was achieved in the TU and TN groups. All 4 techniques improved medial stability compared to that medial collateral ligament injury; however, no technique returned stability to the tarsal of the intact ligament. All 4 techniques maintained stability after range-of-motion testing. Isometric placement of the prosthetic suture was achievable. The constructs did not provide sufficient resistance to physiologic valgus stress. Isometric placement of a prosthetic ligament is possible; secondary stabilization appears necessary to support the repair postoperatively.

Automatic calculation of the parasympathetic, sympathetic and Baevsky stress indexes provides a more comprehensive assessment of cardiac autonomic modulation

Abstract Background Cardiac autonomic modulation (CAM) is clinically evaluated by measuring the Heart Rate Variability (HRV) parameters, related to sympathetic and parasympathetic efferences to the heart, with linear (L), nonlinear (NL), and time-varying (TV) mathematical methods. Recently, automatic calculation of the parasympathetic (PNSi), sympathetic (SNSi), and Baevsky’s stress (BSTRi) indexes [1,2], integrating some L and NL parameters, has become available for more synthetic assessment of CAM. This study aimed to evaluate in healthy subjects (HS) the normal range of PNSi, SNSi, and BSTRi and their physiological variations during daily activity (ACT) and Non-REM sleep (NREM), taking also into account aging-related changes. Methods 24-hour (H24) Holter ECG recordings of 87 HS, divided into three (Age1, Age2 and Age3) groups (16-34, 35-52, and 53-84 years old, respectively), were retrospectively analyzed with the Kubios software (version 4.0), which automatically calculates the PNSi, SNSi, and BSTRi [1], and time domain (TD), frequency domain (FD), NL and TV HRV parameters. HRV was calculated from H24 and short-term (2 minutes) intervals, selected during ACT and NREM. All HRV calculations were done after "detrending" with the "smooth priors" function (lambda=500). Statistical analysis was performed with SPSS 21. Results Average values of the three indexes and several independent L and NL parameters are summarized in Table 1. Average BSTRi values of each age group were not different between ACT and NREM, whereas significant (p<0.05) increments between Age3 and Age1 (during ACT) and between Age3 and both Age1 and 2 (during NREM and H24) were found. Average SNSi values were slightly above the normality range [1] during ACT, or normal (during NREM and H24). Average PNSi values were within the suggested normality range [1] with minimal aging-related variations. Significant aging-related decrement of the selected TD and FD parameters was found in all analysed conditions. Among NL parameters, the correlation dimension (D2) values showed significant aging-related decrement (H24 and NREM), while H24 and ACT sample entropy (SampEn) was lower in Age1 and Age2, compared with Age3 (p<0.05). An example (H24 analysis of Age3 data) of significant (p<0.01) correlation among the three indexes and the selected independent linear and non-linear parameters is shown in Figure 1. Conclusions In this study, a significant aging-related increment of BSTRi was found in all investigated conditions. PNSi and SNSi were always within the suggested normality range [1]. In spite of the significant changes of linear parameters consistent with the well-known aging-related decrement of HRV, the higher SampEn (and BSTRi) found in Age3 HS suggests that an "healthy elderly", is characterized by a more complex adaptation of CAM, likely mediated also by the observed moderate (healthy?) increment of physiological stress. However further investigation on a broader population is warranted.Table 1Figure 1

Leveraging mixed reality in mitraclip implantation: A preliminary case series toward a pilot study

Abstract Introduction The advent of mixed reality (MR) technology, particularly when combined with Hololens 2.0 and specialized software for three-dimensional DICOM image visualization, offers a promising avenue for enhancing the precision and spatial awareness in interventional cardiology procedures. This case series aims to preliminarily evaluate the impact of MR on MitraClip implantation processes, setting a foundation for an ensuing comprehensive pilot study. Methods We conducted a comparative analysis within a case series of four MitraClip implantations, categorizing them into two groups based on the utilization of MR support. We examined procedural efficiency, radiation metrics (SKIA and DAP), and operator stress indicators, including cortisol levels, heart rate variability, QTc interval, and subjective assessments through NASA TLX, STAI Y, and SSQ questionnaires. Results Initial findings from the MR-assisted procedures suggest a notable improvement in procedural efficiency and a reduction in operator stress. Specifically, MR use was associated with shorter procedural times (ranging from 60 to 130 minutes) and lower radiation exposure, with SKIA durations between 15.5 and 40.5 minutes. Moreover, operators in the MR group showed reduced cortisol levels (8.2-9.2 mmol/L), indicating decreased physiological stress. Heart rate variability analysis further supported superior stress management among MR-supported operators. Subjective evaluations reinforced these physiological findings. NASA TLX scores in the MR group (13-20) markedly contrasted with those in the control group (30-45), signifying a significant reduction in perceived workload. SSQ scores remained minimal, implying good MR tolerability, and STAI Y scores (30-35) were lower than those in the control group (40-50), highlighting reduced anxiety levels during MR-assisted procedures. Conclusion This explorative case series lays the groundwork for a forthcoming pilot study, revealing MR's potential to not only streamline MitraClip implantation but also to alleviate operator stress. Both objective and subjective data advocate for expanded research to definitively ascertain MR's benefits in cardiac interventions, promising to refine procedural workflows and enhance patient outcomes. This series acts as a stepping stone towards a larger-scale evaluation that could solidify MR's role in the future of interventional cardiology.Operator's View and Technology PreviewFunction diagram

Emphasizing the Communal Demands of a Leader Role Makes Job Interviews Less Stressful for Women But Not More Successful

AbstractThe cultural construal of leadership as masculine impedes women’s attainment of leader roles. This research examined whether adding feminine demands to a leader role relieved the greater stress experienced by women than men in a job interview for a leadership position and considered the processes that mediated women’s less favourable interview outcomes. In a hiring simulation, management students (N = 209; 112 women, 97 men) interviewed for a leader role framed by either stereotypically feminine or masculine role requirements. As shown by the stress biomarker salivary cortisol, the feminine role framing alleviated women’s, but not men’s, physiological stress response during the interview. However, under both masculine and feminine role framing, women, compared with men, reported lesser fit, expected poorer interview performance, appraised greater threat relative to challenge, and evaluated their performance less favourably, as did external raters. An additional vignette study (N = 305; 189 women, 111 men, 5 diverse) found that the feminine role framing increased the leader role’s communal demands but still conveyed strong agentic demands not different from those of the masculine role. In conclusion, although a feminine role framing alleviated women’s physiological stress response, it did not change their less favourable outcomes, as indicated by participants’ self-reports and others’ reports.

Synthetic assessment of cardiac autonomic modulation and Baevsky stress index in patients with synucleinopathies

Abstract Background The Baevsky Stress Index (BSTRi), calculated from Heart Rate Variability (HRV) data, has been proposed for quantitative assessment of physiological stress, with higher scores indicating higher levels of physical and/or psychological stress [1]. Cardiac autonomic modulation can be synthetically quantified by calculating the parasympathetic (PNSi) and the sympathetic (SNSi) indexes. The values of the BSTRi, SNSi, and PNSi in patients with synucleinopathies of different prognoses have not been reported yet. Purpose To quantify, in patients with Parkinson's disease (PD) and Multisystem Atrophy (MSA), the BSTRi, its correlation with the PNSi and the SNSi indexes, and their potential value for a synthetic assessment of cardiac autonomic modulation and early differential diagnosis between PD and MSA. Methods Holter ECG data of 66 patients with Parkinsonian syndromes were retrospectively analyzed after 10 years of follow-up. Out of them, 34 patients with a certain diagnosis of PD (17) and MSA (17) were selected for this study. HRV was analyzed with the Kubios software (version 4.0), providing automatic calculation of the BSTRi, PNSi, and SNSi [2], as well as of time domain (TD), frequency domain (FD), nonlinear (NL), and time-varying (TV) HRV parameters. HRV was calculated from selected short-term intervals (of 5 minutes), during daily activity (ACT5’), and non-REM sleep (NREM5’), and from 24-hours Holter recordings. Patients’ HRV findings were compared with those of 51 age-matched healthy subjects (HS). Results An example of individual automatic graphic summary is shown in Figure 1. Both short-term and 24-hour BSTRi and SNSi values were significantly (p < 0.05) higher in PD and MSA compared to those of HS, in all investigated conditions. Short-term PNSi was significantly higher in HS than in PD in all conditions, but only during NREM5’ in MSA patients (Table 1). No significant difference was found between the indexes of PD and MSA patients. As in HS (R=92), BSTRi was positively correlated with the SNSi in MSA (average R= 0.83 and 0.89 during ACT5’ and NREM5’, respectively), but less evident in PD (R=0.67). The inverse correlation between PNSi and SNSi (R=0.75 in HS) was lost in both MSA and PD. Conclusions Higher values of BSTRi in PD and MSA compared to HS suggest that patients with synucleinopathies do experience higher levels of psychophysiological stress, which may affect their quality of life negatively. However, since no significant difference was found in this study between BSTRi values of PD and MSA patients, BSTRi seems at present unreliable for early differentiation between the two diseases. Telematic assessment of BSTRi, SNSi, and PNSi could be useful for remote monitoring of PD and MSA patients’ psychophysiological stress, to provide timely intervention and adaptive treatment.Fig.1 Example of graphic summary (ACT5')

Mindfulness Exercises Reduce Acute Physiologic Stress Among Female Clinicians.

Approximately 50% of clinicians experience excessive emotional, physical, and mental stress, with repercussions across the entire medical system. Mindfulness exercises may mitigate this excessive stress. Heart rate variability (HRV) is an objective stress measure that can quantify which mindfulness exercises provide the greatest stress reduction. To define the impact of specific mindfulness exercises on HRV, a surrogate for physiologic stress, and the relationship between physiologic (HRV) and subjective stress measured by the State-Trait Anxiety Inventory during a one-day mindfulness workshop. This was a prospective observational pilot study performed at a quaternary children's hospital with diverse subspecialists of pediatric nurses, nurse practitioners, and physicians. Our primary outcome measure was change in HRV from baseline during three mindfulness exercises. The grounding, deep breathing, and body scan exercises all produced statistically significant changes in HRV among our 13 female participants. The body scan exercise produced statistically significant changes in all studied HRV parameters compared with baseline. We observed significant increases in Root Mean Square of Successive Differences between normal heartbeats (p = 0.026), high frequency (p ≤ 0.001), and the parasympathetic nervous system index (p ≤ 0.001) reflecting increased parasympathetic tone (e.g., relaxation), whereas sd 2/sd 1 ratio (p ≤ 0.001) and the stress index (p = 0.004) were decreased reflecting sympathetic withdrawal (e.g., decreased stress). Subjective stress decreased after 1-day mindfulness training (44.6 to 27.2) (p < 0.001). Individuals with the largest decrease in subjective stress also had the most improvement in HRV during the body scan exercise. Clinician stress levels (HRV) improved after participating in grounding, deep breathing, and body scan meditations, which may highlight their importance as stress reduction tools for clinicians. Monitoring of HRV during mindfulness exercises may provide deeper understanding of which specific exercises produce the greatest physiologic stress reduction for individual participants and the trend of these changes over time.