Hydrothermal extraction of ulvans from Ulva spp. in a biorefinery approach.

A simple cascade process based on the hydrothermal fractionation of Ulva spp. biomass was proposed. Considering the overall extraction yields (50 %), ulvan recovery (23 %), and ulvan composition, structural, mechanical and cytotoxic properties, the selected optimal final heating temperature was 160 °C. Ethanol precipitation provided the highest ulvan recovery yields but choline chloride precipitated ulvans showed stronger mechanical properties, G´ moduli 1.5·104 Pa and 3·104 Pa for ethanol and for choline chloride, respectively. Both products were safe on L929 mouse fibroblasts and after a cooling stage, formed films without requiring any additives. From the ulvan-free liquid fraction, one product with 43 % (wt, d.b.) phenolics and moderate antiradical properties and a byproduct containing nutrients and minerals were separated. The methane potential of the corresponding residual solids was influenced by the hydrothermal heating temperature and was doubled compared to than for the untreated seaweed biomass (60 mL/g VS). This scheme could be also applied to the wet algal biomass, in a chemical free alternative to provide ready to use ulvan biopolymers, bioactives, nutrients, salts and biogas, conforming a biorefinery approach.

Definitions of Having Sex in Older Men and Women and Their Relationship with Sexual Well-Being.

The goal of this study was to explore the sexual activities that older adults consider as having had sex and to examine correlates of the ways that older men and women define sex. A sample of 286 men and women aged 60 years and older who were involved in a romantic relationship were recruited online from Prolific and Facebook advertisements. Participants were presented a list of 19 different sexual activities and asked whether they would think they had sex if they engaged in each one of those activities. Results showed that penetrative sexual activities were found to be the most likely endorsed as having had sex, followed by genital non-penetrative activities, masturbation activities, and non-genital contact. Greater sexual frequency for a sexual activity was associated with endorsing that same activity as having had sex. A cluster analysis revealed five different groups of individuals based on the activities that they considered as having had sex. Only small differences in sexual wellbeing were found among these groups of individuals. The way older men and women define sex is complex and shows great variability. Our results have important implications for the operationalization and assessment of sexual activity. Other implications for healthcare and future research are discussed.

Ras suppression potentiates rear actomyosin contractility-driven cell polarization and migration.

Ras has been extensively studied as a promoter of cell proliferation, whereas few studies have explored its role in migration. To investigate the direct and immediate effects of Ras activity on cell motility or polarity, we focused on RasGAPs, C2GAPB in Dictyostelium amoebae and RASAL3 in HL-60 neutrophils and macrophages. In both cellular systems, optically recruiting the respective RasGAP to the cell front extinguished pre-existing protrusions and changed migration direction. However, when these respective RasGAPs were recruited uniformly to the membrane, cells polarized and moved more rapidly, whereas targeting to the back exaggerated these effects. These unexpected outcomes of attenuating Ras activity naturally had strong, context-dependent consequences for chemotaxis. The RasGAP-mediated polarization depended critically on myosin II activity and commenced with contraction at the cell rear, followed by sustained mTORC2-dependent actin polymerization at the front. These experimental results were captured by computational simulations in which Ras levels control front- and back-promoting feedback loops. The discovery that inhibiting Ras activity can produce counterintuitive effects on cell migration has important implications for future drug-design strategies targeting oncogenic Ras.

Synthetic control of actin polymerization and symmetry breaking in active protocells.

Nonlinear biomolecular interactions on membranes drive membrane remodeling crucial for biological processes including chemotaxis, cytokinesis, and endocytosis. The complexity of biomolecular interactions, their redundancy, and the importance of spatiotemporal context in membrane organization impede understanding of the physical principles governing membrane mechanics. Developing a minimal in vitro system that mimics molecular signaling and membrane remodeling while maintaining physiological fidelity poses a major challenge. Inspired by chemotaxis, we reconstructed chemically regulated actin polymerization inside vesicles, guiding membrane self-organization. An external, undirected chemical input induced directed actin polymerization and membrane deformation uncorrelated with upstream biochemical cues, suggesting symmetry breaking. A biophysical model incorporating actin dynamics and membrane mechanics proposes that uneven actin distributions cause nonlinear membrane deformations, consistent with experimental findings. This protocellular system illuminates the interplay between actin dynamics and membrane shape during symmetry breaking, offering insights into chemotaxis and other cell biological processes.

Sexual Activity of Older Adults: A Systematic Review of the Literature.

Objective: The goal was to conduct a literature review of studies that examined sexual activity in older adults. Method: A systematic search was conducted to identify studies that had examined sexual activity in adults aged 60 years and older. The main characteristics of each study and results were examined and reported according to PRISMA guidelines. Results: Sixty-three articles were found. These articles were classified into three main groups based on the results they presented: percentage of older adults that were sexually active; frequency of sexual activity; and type of sexual activities. The results show that older adults are sexually active, engage in frequent sexual activity, and participate in a wide variety of activities. Conclusions: Although older adults remain sexually active, differences in the way sexual activity is assessed limit the drawing of firm conclusions and our understanding of the sexual activity of older adults. We propose a series of recommendations to gain a better understanding of this topic.

Complementary Cytoskeletal Feedback Loops Control Signal Transduction Excitability and Cell Polarity.

To move through complex environments, cells must constantly integrate chemical and mechanical cues. Signaling networks, such as those comprising Ras and PI3K, transmit chemical cues to the cytoskeleton, but the cytoskeleton must also relay mechanical information back to those signaling systems. Using novel synthetic tools to acutely control specific elements of the cytoskeleton in Dictyostelium and neutrophils, we delineate feedback mechanisms that alter the signaling network and promote front- or back-states of the cell membrane and cortex. First, increasing branched actin assembly increases Ras/PI3K activation while reducing polymeric actin levels overall decreases activation. Second, reducing myosin II assembly immediately increases Ras/PI3K activation and sensitivity to chemotactic stimuli. Third, inhibiting branched actin alone increases cortical actin assembly and strongly blocks Ras/PI3K activation. This effect is mitigated by reducing filamentous actin levels and in cells lacking myosin II. Finally, increasing actin crosslinking with a controllable activator of cytoskeletal regulator RacE leads to a large decrease in Ras activation both globally and locally. Curiously, RacE activation can trigger cell spreading and protrusion with no detectable activation of branched actin nucleators. Taken together with legacy data that Ras/PI3K promotes branched actin assembly and myosin II disassembly, our results define front- and back-promoting positive feedback loops. We propose that these loops play a crucial role in establishing cell polarity and mediating signal integration by controlling the excitable state of the signal transduction networks in respective regions of the membrane and cortex. This interplay enables cells to navigate intricate topologies like tissues containing other cells, the extracellular matrix, and fluids.

A dynamic partitioning mechanism polarizes membrane protein distribution.

The plasma membrane is widely regarded as the hub of the numerous signal transduction activities. Yet, the fundamental biophysical mechanisms that spatiotemporally compartmentalize different classes of membrane proteins remain unclear. Using multimodal live-cell imaging, here we first show that several lipid-anchored membrane proteins are consistently depleted from the membrane regions where the Ras/PI3K/Akt/F-actin network is activated. The dynamic polarization of these proteins does not depend upon the F-actin-based cytoskeletal structures, recurring shuttling between membrane and cytosol, or directed vesicular trafficking. Photoconversion microscopy and single-molecule measurements demonstrate that these lipid-anchored molecules have substantially dissimilar diffusion profiles in different regions of the membrane which enable their selective segregation. When these diffusion coefficients are incorporated into an excitable network-based stochastic reaction-diffusion model, simulations reveal that the altered affinity mediated selective partitioning is sufficient to drive familiar propagating wave patterns. Furthermore, normally uniform integral and lipid-anchored membrane proteins partition successfully when membrane domain-specific peptides are optogenetically recruited to them. We propose "dynamic partitioning" as a new mechanism that can account for large-scale compartmentalization of a wide array of lipid-anchored and integral membrane proteins during various physiological processes where membrane polarizes.

Synthetic control of actin polymerization and symmetry breaking in active protocells.

Non-linear biomolecular interactions on the membranes drive membrane remodeling that underlies fundamental biological processes including chemotaxis, cytokinesis, and endocytosis. The multitude of biomolecules, the redundancy in their interactions, and the importance of spatiotemporal context in membrane organization hampers understanding the physical principles governing membrane mechanics. A minimal, in vitro system that models the functional interactions between molecular signaling and membrane remodeling, while remaining faithful to cellular physiology and geometry is powerful yet remains unachieved. Here, inspired by the biophysical processes underpinning chemotaxis, we reconstituted externally-controlled actin polymerization inside giant unilamellar vesicles, guiding self-organization on the membrane. We show that applying undirected external chemical inputs to this system results in directed actin polymerization and membrane deformation that are uncorrelated with upstream biochemical cues, indicating symmetry breaking. A biophysical model of the dynamics and mechanics of both actin polymerization and membrane shape suggests that inhomogeneous distributions of actin generate membrane shape deformations in a non-linear fashion, a prediction consistent with experimental measurements and subsequent local perturbations. The active protocellular system demonstrates the interplay between actin dynamics and membrane shape in a symmetry breaking context that is relevant to chemotaxis and a suite of other biological processes.

Decoding Angiotensin Receptors: TOMAHAQ-Based Detection and Quantification of Angiotensin Type-1 and Type-2 Receptors.

Background The renin-angiotensin system plays a crucial role in human physiology, and its main hormone, angiotensin, activates 2 G-protein-coupled receptors, the angiotensin type-1 and type-2 receptors, in almost every organ. However, controversy exists about the location, distribution, and expression levels of these receptors. Concerns have been raised over the low sensitivity, low specificity, and large variability between lots of commercially available antibodies for angiotensin type-1 and type-2 receptors, which makes it difficult to reconciliate results of different studies. Here, we describe the first non-antibody-based sensitive and specific targeted quantitative mass spectrometry assay for angiotensin receptors. Methods and Results Using a technique that allows targeted analysis of multiple peptides across multiple samples in a single mass spectrometry analysis, known as TOMAHAQ (triggered by offset, multiplexed, accurate mass, high resolution, and absolute quantification), we have identified and validated specific human tryptic peptides that permit identification and quantification of angiotensin type-1 and type-2 receptors in biological samples. Several peptide sequences are conserved in rodents, making these mass spectrometry assays amenable to both preclinical and clinical studies. We have used this method to quantify angiotensin type-1 and type-2 receptors in postmortem frontal cortex samples of older adults (n=28) with Alzheimer dementia. We correlated levels of angiotensin receptors to biomarkers classically linked to renin-angiotensin system activation, including oxidative stress, inflammation, amyloid-ß load, and paired helical filament-tau tangle burden. Conclusions These robust high-throughput assays will not only catalyze novel mechanistic studies in the angiotensin research field but may also help to identify patients with an unbalanced angiotensin receptor distribution who would benefit from angiotensin receptor blocker treatment.

Ras-mediated homeostatic control of front-back signaling dictates cell polarity.

Studies in the model systems, Dictyostelium amoebae and HL-60 neutrophils, have shown that local Ras activity directly regulates cell motility or polarity. Localized Ras activation on the membrane is spatiotemporally regulated by its activators, RasGEFs, and inhibitors, RasGAPs, which might be expected to create a stable 'front' and 'back', respectively, in migrating cells. Focusing on C2GAPB in amoebae and RASAL3 in neutrophils, we investigated how Ras activity along the cortex controls polarity. Since existing gene knockout and overexpression studies can be circumvented, we chose optogenetic approaches to assess the immediate, local effects of these Ras regulators on the cell cortex. In both cellular systems, optically targeting the respective RasGAPs to the cell front extinguished existing protrusions and changed the direction of migration, as might be expected. However, when the expression of C2GAPB was induced globally, amoebae polarized within hours. Furthermore, within minutes of globally recruiting either C2GAPB in amoebae or RASAL3 in neutrophils, each cell type polarized and moved more rapidly. Targeting the RasGAPs to the cell backs exaggerated these effects on migration and polarity. Overall, in both cell types, RasGAP-mediated polarization was brought about by increased actomyosin contractility at the back and sustained, localized F-actin polymerization at the front. These experimental results were accurately captured by computational simulations in which Ras levels control front and back feedback loops. The discovery that context-dependent Ras activity on the cell cortex has counterintuitive, unanticipated effects on cell polarity can have important implications for future drug-design strategies targeting oncogenic Ras.

Sexual satisfaction in prostate cancer: a multi-group comparison study of treated patients, patients under active surveillance, patients with negative biopsy, and controls.

PURPOSE: Erectile function changes after prostate cancer (PCa) treatment are well documented, but less understood is the relative impact of prostate biopsy and active surveillance on sexual well-being. It is unknown whether potential negative impacts are exclusive to patients who have been treated for PCa, or whether the diagnosis itself or the experience of biopsy may also impact sexual well-being. Sexual satisfaction is an important yet understudied indicator of sexual well-being in this population. This study examines sexual satisfaction and its predictors across several comparison groups to explore relative impact. METHODS: At baseline and 12 months, questionnaire data was collected in four samples: (1) following PCa treatment, (2) active surveillance, (3) negative prostate biopsy result, and (4) controls receiving no biopsy or treatment. Predictors assessed included group, erectile function, communication style, and partner involvement. RESULTS: Sexual satisfaction declined in the active treatment group, no changes were observed in active surveillance or non-PCa control, and improvements were observed in the biopsy group. Predictors of sexual satisfaction over and above erectile function included restrictive communication (i.e. protective buffering) and perceived partner involvement. For higher levels of erectile function, a higher perceived degree of partner involvement was protective of sexual satisfaction. CONCLUSION: Sexual satisfaction is an important indicator of sexual well-being and is negatively impacted following PCa treatment, but not active surveillance or prostate biopsy. IMPLICATIONS FOR CANCER SURVIVORS: Communication and partner involvement are potentially modifiable factors to be considered for intervention and may promote sexual satisfaction following PCa treatment. Patients experiencing negative biopsy, who note lower sexual satisfaction may experience improved satisfaction with time, and those under active surveillance who worry about sexual satisfaction may find reassurance from these results.

A New Opportunity for "Old" Molecules: Targeting PARP1 Activity through a Non-Enzymatic Mechanism.

In recent years, new therapies have been developed based on molecules that target molecular mechanisms involved in both the initiation and maintenance of the oncogenic process. Among these molecules are the poly(ADP-ribose) polymerase 1 (PARP1) inhibitors. PARP1 has emerged as a target with great therapeutic potential for some tumor types, drawing attention to this enzyme and resulting in many small molecule inhibitors of its enzymatic activity. Therefore, many PARP inhibitors are currently in clinical trials for the treatment of homologous recombination (HR)-deficient tumors, BRCA-related cancers, taking advantage of synthetic lethality. In addition, several novel cellular functions unrelated to its role in DNA repair have been described, including post-translational modification of transcription factors, or acting through protein-protein interactions as a co-activator or co-repressor of transcription. Previously, we reported that this enzyme may play a key role as a transcriptional co-activator of an important component of cell cycle regulation, the transcription factor E2F1. Here, we show that PARP inhibitors, which interfere with its activity in cell cycle regulation, perform this without affecting its enzymatic function.

Actuation of single downstream nodes in growth factor network steers immune cell migration.

Ras signaling is typically associated with cell growth, but not direct regulation of motility or polarity. By optogenetically targeting different nodes in the Ras/PI3K/Akt network in differentiated human HL-60 neutrophils, we abruptly altered protrusive activity, bypassing the chemoattractant receptor/G-protein network. First, global recruitment of active KRas4B/HRas isoforms or a RasGEF, RasGRP4, immediately increased spreading and random motility. Second, activating Ras at the cell rear generated new protrusions, reversed pre-existing polarity, and steered sustained migration in neutrophils or murine RAW 264.7 macrophages. Third, recruiting a RasGAP, RASAL3, to cell fronts extinguished protrusions and changed migration direction. Remarkably, persistent RASAL3 recruitment at stable fronts abrogated directed migration in three different chemoattractant gradients. Fourth, local recruitment of the Ras-mTORC2 effector, Akt, in neutrophils or Dictyostelium amoebae generated new protrusions and rearranged pre-existing polarity. Overall, these optogenetic effects were mTORC2-dependent but relatively independent of PI3K. Thus, receptor-independent, local activations of classical growth-control pathways directly control actin assembly, cell shape, and migration modes.

Comparative analysis of the burnout syndrome index between contract and freelance physiotherapists: An observational study.

BACKGROUND: Burnout syndrome has been extensively studied in different health science professions. It has been less studied in physiotherapy than in professions such as medicine. Moreover, it is not known how the working condition influences this syndrome. OBJECTIVE: The main objective of this study was to compare the burnout index between contract and freelance physiotherapists in the private sector in the Community of Madrid, Spain. METHODS: A cross-sectional study was performed with 174 participants divided into 2 groups; one group was composed of contract physiotherapists (n = 87) and the other group was composed of freelance physiotherapists (n = 87). A Mann-Whitney U test was performed for comparison between the groups. Spearman's correlation coefficient was used to analyze the correlations between the burnout syndrome index and the secondary variables. RESULTS: There were statistically significant differences when comparing the groups, with a large effect size for the burnout index with a higher rate among contract physiotherapists (78 [71-84.75]) than in freelance physiotherapists (61.5 [55-72.75]).There were also significant differences in the type of patients treated, number of patients treated per day, time spent per patient, and the annual salary range between the contract and freelance physiotherapists. CONCLUSION: Contract physiotherapists who participated in this study had a significantly higher burnout syndrome index than freelance physiotherapists. Other socio-occupational variables were also found to be related to the burnout syndrome index in freelance physiotherapists and contract physiotherapists. The results of this study could be of interest for new occupational health strategies to reduce the burnout index in contract physiotherapists.

Nanotopography modulates intracellular excitable systems through cytoskeleton actuation.

Cellular sensing of most environmental cues involves receptors that affect a signal-transduction excitable network (STEN), which is coupled to a cytoskeletal excitable network (CEN). We show that the mechanism of sensing of nanoridges is fundamentally different. CEN activity occurs preferentially on nanoridges, whereas STEN activity is constrained between nanoridges. In the absence of STEN, waves disappear, but long-lasting F-actin puncta persist along the ridges. When CEN is suppressed, wave propagation is no longer constrained by nanoridges. A computational model reproduces these experimental observations. Our findings indicate that nanotopography is sensed directly by CEN, whereas STEN is only indirectly affected due to a CEN-STEN feedback loop. These results explain why texture sensing is robust and acts cooperatively with multiple other guidance cues in complex, in vivo microenvironments.

Implementation of individually tailored treatment plans in a group-based intervention for women with mixed vulvo-vaginal and sexual health concerns following cancer treatment: A feasibility study.

PURPOSE: This study evaluated a professionally-led, group-based vulvo-vaginal and sexual health (VSH) workshop for women diagnosed with cancer. The study goals were to: (1) implement and assess a novel group intervention for diverse VSH concerns; (2) explore post-workshop changes in symptom bother, motivation to use VSH treatments, and frequency of VSH treatment use; (3) examine post-workshop changes in sexual well-being. METHODS: A group-based educational workshop to address a variety of VSH concerns was developed and implemented. During the workshop, participants created an individualized treatment plan by selecting from various VSH treatment options presented. Treatment plan follow-ups were administered online at one-, two-, and three-months post-workshop. At baseline and three-month follow-up, participants completed online questionnaires to assess self-reported vulvo-vaginal symptoms, sexual function, sexual distress, and use of VSH strategies. RESULTS: 195 participants (age 20-81) attended workshops over a 2.5-year period. Individualized treatment plans were effectively completed by most participants (92%). Preliminary results show decreases in bother severity associated with VSH concerns post-workshop, stabilizing after 2 months. At three-month follow-up, participants reported increased use of VSH treatment strategies. Sexual satisfaction, sexual distress, and emotional impact of vulvovaginal symptoms also improved. CONCLUSIONS: Workshop attendance was associated with increased uptake of VSH treatment strategies and improvements in several parameters of sexual well-being. Findings indicate that individualized treatment plans can be implemented effectively in a group setting and that a one-time, group-based educational workshop can meaningfully impact VSH-related behavior change, reduce vulvo-vaginal symptom bother and promote sexual well-being in patients with diverse VSH concerns.

A dynamic partitioning mechanism polarizes membrane protein distribution.

The plasma membrane is widely regarded as the hub of the signal transduction network activities that drives numerous physiological responses, including cell polarity and migration. Yet, the symmetry breaking process in the membrane, that leads to dynamic compartmentalization of different proteins, remains poorly understood. Using multimodal live-cell imaging, here we first show that multiple endogenous and synthetic lipid-anchored proteins, despite maintaining stable tight association with the inner leaflet of the plasma membrane, were unexpectedly depleted from the membrane domains where the signaling network was spontaneously activated such as in the new protrusions as well as within the propagating ventral waves. Although their asymmetric patterns resembled those of standard peripheral "back" proteins such as PTEN, unlike the latter, these lipidated proteins did not dissociate from the membrane upon global receptor activation. Our experiments not only discounted the possibility of recurrent reversible translocation from membrane to cytosol as it occurs for weakly bound peripheral membrane proteins, but also ruled out the necessity of directed vesicular trafficking and cytoskeletal supramolecular structure-based restrictions in driving these dynamic symmetry breaking events. Selective photoconversion-based protein tracking assays suggested that these asymmetric patterns instead originate from the inherent ability of these membrane proteins to "dynamically partition" into distinct domains within the plane of the membrane. Consistently, single-molecule measurements showed that these lipid-anchored molecules have substantially dissimilar diffusion profiles in different regions of the membrane. When these profiles were incorporated into an excitable network-based stochastic reaction-diffusion model of the system, simulations revealed that our proposed "dynamic partitioning" mechanism is sufficient to give rise to familiar asymmetric propagating wave patterns. Moreover, we demonstrated that normally uniform integral and lipid-anchored membrane proteins in Dictyostelium and mammalian neutrophil cells can be induced to partition spatiotemporally to form polarized patterns, by optogenetically recruiting membrane domain-specific peptides to these proteins. Together, our results indicate "dynamic partitioning" as a new mechanism of plasma membrane organization, that can account for large-scale compartmentalization of a wide array of lipid-anchored and integral membrane proteins in different physiological processes.

Donor lungs cold preservation at 10 °C offers a potential logistic advantage in lung transplantation.

Donor lung preservation at 10 °C appears to be an innovative and promising method that may improve transplant logistics by extending the cold ischemia time with excellent outcomes. We report the case of two lung transplants from two different donors involving the use of two different preservation methods, highlighting the benefits of using 10 °C lung storage.