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1.
PLoS One ; 19(9): e0301885, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39241089

RESUMEN

Horse's stress responses have been reported during road transport in temperate but not tropical environments. Therefore, this study measured cortisol levels, heart rate (HR), and heart rate variability (HRV) in horses during medium-distance road transport with different truck conditions in a tropical environment. Six horses were repeatedly transported in either air-conditioned trucks with full (ATF) or space (ATS) loads or non-air-conditioned trucks with full (N-ATF) and space (N-ATS) loads. Blood cortisol was determined beforehand and 5, 30, and 90 minutes post-transport. HR and HRV were assessed pre-transport and at 15-minute intervals until 90 minutes post-transport. Cortisol levels increased significantly in N-ATS horses (but non-significantly in ATF, ATS, and N-ATF horses) at 5 minutes post-transport and returned to baseline by 30 minutes post-transport. Predominant parasympathetic nervous system (PNS) activity was observed during the first few hours and returned to baseline until the destination was reached. A recurrent, increased PNS activity was detected post-transport. Interaction effects of air condition-by-loading condition-by-time, air condition-by-time, and separate effects of air condition and time were observed on HR and various HRV variables during transport. A transient increase in beat-to-beat intervals, coinciding with decreased HR, was observed in ATF horses. The PNS index increased, corresponding to a decreased sympathetic nervous system index, in ATS horses during transport. We suggest that medium-distance road transport causes no stress for transport-experienced horses in a tropical environment. Air and loading conditions impacted hormonal and autonomic modulation, causing different responses in horses transported in differently conditioned trucks.


Asunto(s)
Sistema Nervioso Autónomo , Frecuencia Cardíaca , Hidrocortisona , Transportes , Clima Tropical , Animales , Caballos/fisiología , Frecuencia Cardíaca/fisiología , Hidrocortisona/sangre , Hidrocortisona/metabolismo , Sistema Nervioso Autónomo/fisiología , Masculino , Estrés Fisiológico/fisiología , Vehículos a Motor , Femenino
2.
Proc Natl Acad Sci U S A ; 121(39): e2402233121, 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39284054

RESUMEN

A fundamental assumption in plant science posits that leaf air spaces remain vapor saturated, leading to the predominant view that stomata alone control leaf water loss. This concept has been pivotal in photosynthesis and water-use efficiency research. However, recent evidence has refuted this longstanding assumption by providing evidence of unsaturation in the leaf air space of C3 plants under relatively mild vapor pressure deficit (VPD) stress. This phenomenon represents a nonstomatal mechanism restricting water loss from the mesophyll. The potential ubiquity and physiological implications of this phenomenon, its driving mechanisms in different plant species and habitats, and its interaction with other ecological adaptations have. In this context, C4 plants spark particular interest for their importance as crops, bundle sheath cells' unique anatomical characteristics and specialized functions, and notably higher water-use efficiency relative to C3 plants. Here, we confirm reduced relative humidities in the substomatal cavity of the C4 plants maize, sorghum, and proso millet down to 80% under mild VPD stress. We demonstrate the critical role of nonstomatal control in these plants, indicating that the role of the CO2 concentration mechanism in CO2 management at a high VPD may have been overestimated. Our findings offer a mechanistic reconciliation between discrepancies in CO2 and VPD responses reported in C4 species. They also reveal that nonstomatal control is integral to maintaining an advantageous microclimate of relatively higher CO2 concentrations in the mesophyll air space of C4 plants for carbon fixation, proving vital when these plants face VPD stress.


Asunto(s)
Células del Mesófilo , Fotosíntesis , Presión de Vapor , Zea mays , Células del Mesófilo/metabolismo , Zea mays/fisiología , Zea mays/metabolismo , Fotosíntesis/fisiología , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Agua/metabolismo , Estrés Fisiológico/fisiología , Dióxido de Carbono/metabolismo , Sorghum/metabolismo , Sorghum/fisiología , Estomas de Plantas/fisiología , Estomas de Plantas/metabolismo
3.
Ecol Evol Physiol ; 97(4): 209-219, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39270327

RESUMEN

AbstractThe overlap between spatial and physiological ecology is generally understudied, yet both fields are fundamentally related in assessing how individuals balance limited resources. Herein, we quantified the relationships between spatial ecology using two parameters of home range (annual home range area and number of burrows used in 1 yr) and four measures of physiology that integrate stress and immunity (baseline plasma corticosterone [CORT] concentration, plasma lactate concentration, heterophil-to-lymphocyte [H∶L] ratio, and bactericidal ability [BA]) in a wild free-ranging population of the gopher tortoise (Gopherus polyphemus) to test the hypothesis that space usage is correlated with physiological state. We also used structural equation models (SEMs) to test for causative relationships between the spatial and physiological parameters. We predicted that larger home ranges would be negatively correlated with traditional biomarkers of stress and positively correlated with immunity, consistent with our hypothesis that home ranges are determined based on individual condition. Males had larger home ranges, used more burrows, and had higher baseline CORT than females. We found significant negative correlations between lactate and home range (r=-0.456, df=21, P=0.029). CORT was negatively correlated with the number of burrows used in both sexes (F=7.322, df=2,20, P=0.003, adjusted R2=0.383). No correlations were observed between space use and BA or, notably, H∶L ratio. SEMs suggested that variation in the number of burrows used was a result of variation in baseline CORT. The lack of a relationship between H∶L ratio and home range suggests that home range differences are not associated with differences in chronic stress, despite the pattern between baseline CORT and number of burrows used. Instead, this study indicates that animals balance trade-offs in energetics, likely by way of baseline corticosteroid, in such a way as to maintain function across continuously variable home range strategies.


Asunto(s)
Tortugas , Animales , Tortugas/fisiología , Tortugas/sangre , Tortugas/inmunología , Masculino , Femenino , Fenómenos de Retorno al Lugar Habitual/fisiología , Corticosterona/sangre , Estrés Fisiológico/fisiología , Ácido Láctico/sangre
4.
Reprod Fertil Dev ; 362024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39265060

RESUMEN

Context Sires differ in their ability to produce viable blastocysts, yet our understanding of the cellular mechanisms regulated by the sire during early embryo development is limited. Aims The first aim was to characterise autophagy and reactive oxygen species (ROS) in embryos produced by high and low performing sires under normal and stress culture conditions. The second aim was to evaluate DNA damage and lipid peroxidation as mechanisms that may be impacted by increased cellular stress, specifically oxidative stress. Methods Embryos were produced using four high and four low performing sires based on their ability to produce embryos. Autophagy and ROS were measured throughout development. To evaluate oxidative stress response, autophagy, and ROS were measured in 2-6 cell embryos exposed to heat stress. To understand how cellular stress impacts development, DNA damage and lipid peroxidation were assessed. Key results Under normal conditions, embryos from low performing sires had increased ROS and autophagy. Under heat stress, embryos from low performing sires had increased ROS, yet those from high performing sires had increased autophagy. There was no difference in DNA damage or lipid peroxidation. Conclusions Results suggest that embryos from low performing sires may begin development under increased cellular stress, and autophagy potentially increases to mitigate the impacts of stress. Implications There is potential for improving embryonic competence through selection of sires with lower stress-related markers.


Asunto(s)
Autofagia , Daño del ADN , Desarrollo Embrionario , Peroxidación de Lípido , Estrés Oxidativo , Especies Reactivas de Oxígeno , Animales , Bovinos , Especies Reactivas de Oxígeno/metabolismo , Estrés Oxidativo/fisiología , Peroxidación de Lípido/fisiología , Autofagia/fisiología , Desarrollo Embrionario/fisiología , Femenino , Masculino , Blastocisto/metabolismo , Técnicas de Cultivo de Embriones/veterinaria , Fertilización In Vitro/veterinaria , Embarazo , Estrés Fisiológico/fisiología
5.
Neurosci Lett ; 839: 137931, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39128819

RESUMEN

Food deprivation is used in many experimental models and is becoming increasingly prevalent in human diets. The impact of food deprivation on specific brain regions, including the nucleus of the tractus solitarius (NTS), a region that is involved in hunger and satiety sensing, remains to be determined. The NTS is a heterogeneous nucleus that includes corticotropin releasing factor receptor 1 (CRF1) neurons. CRF1 is implicated in both stress and appetite regulation, but the effects of food deprivation on CRF1 NTS neurons are unclear. We used immunofluorescence to examine the effects of 24-hour food deprivation on NTS activity in male and female Sprague-Dawley (SD) rats and CRF1-cre rats using cFos, an immediate early gene and neuronal marker of activation. NTS activity was increased in food deprived male but not female SD rats. In food deprived CRF1-cre rats, males had an increased proportion of active CRF1 + neurons with no change in females. In CRF1-cre rats, increased global NTS activity was observed in food deprived and refed males. Activation of CRF1 + neurons was also increased after deprivation but was reduced by refeeding. In females, food deprivation decreased global NTS activity that was then increased by refeeding, while CRF1 activity was unchanged. Collectively, these data suggest the NTS is differentially activated after food deprivation in a sex-specific manner, whereby males are more sensitive than females. These results provide insight into the role of brainstem stress circuitry in changes associated with conditions including intermittent fasting and eating disorders like anorexia.


Asunto(s)
Privación de Alimentos , Neuronas , Ratas Sprague-Dawley , Caracteres Sexuales , Núcleo Solitario , Animales , Núcleo Solitario/metabolismo , Masculino , Femenino , Privación de Alimentos/fisiología , Neuronas/metabolismo , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Receptores de Hormona Liberadora de Corticotropina/genética , Ratas , Estrés Fisiológico/fisiología
6.
Sensors (Basel) ; 24(16)2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39204955

RESUMEN

This study focuses on the promising use of biospeckle technology to detect water stress in plants, a complex physiological mechanism. This involves monitoring the temporal activity of biospeckle pattern to study the occurrence of stress within the leaf. The effects of water stress in plants can involve physical and biochemical changes. Some of these changes may alter the optical scattering properties of leaves. The present study therefore proposes to test the potential of a biospeckle measurement to observe the temporal evolution in different varieties of sunflower plants under water stress. An experiment applying controlled water stress with osmotic shock using polyethylene glycol 6000 (PEG) was conducted on two sunflower varieties: one sensitive, and the other more tolerant to water stress. Temporal monitoring of biospeckle activity in these plants was performed using the average value of difference (AVD) indicator. Results indicate that AVD highlights the difference in biospeckle activity between day and night, with lower activity at night for both varieties. The addition of PEG entailed a gradual decrease in values throughout the experiment, particularly for the sensitive variety. The results obtained are consistent with the behaviour of the varieties submitted to water stress. Indeed, a few days after the introduction of PEG, a stronger decrease in AVD indicator values was observed for the sensitive variety than for the resistant variety. This study highlights the dynamics of biospeckle activity for different sunflower varieties undergoing water stress and can be considered as a promising phenotyping tool.


Asunto(s)
Helianthus , Rayos Láser , Fitomejoramiento , Hojas de la Planta , Helianthus/fisiología , Fitomejoramiento/métodos , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Deshidratación , Agua/química , Agua/metabolismo , Polietilenglicoles/química , Estrés Fisiológico/fisiología
7.
Sheng Li Xue Bao ; 76(4): 663-671, 2024 Aug 25.
Artículo en Chino | MEDLINE | ID: mdl-39192798

RESUMEN

The activation of stressors can disrupt the body's homeostasis, leading to the release of stress hormones such as epinephrine, noradrenaline, and glucocorticoids. Moreover, emerging evidence highlights the profound impact of stress on microglia, which are specialized macrophages residing in the brain's parenchyma. Following stress, microglia exhibit notable morphological activation and increased phagocytic activity. Microglia express various receptors that enable them to respond to stress hormones originating from both central and peripheral sources, thereby exerting pro-inflammatory or anti-inflammatory effects. In this article, we review the advancements in studying the structural and functional changes of microglia induced by exposure to stressors. Additionally, we explore the role of stress hormones in mediating the effects of these stressors on microglia.


Asunto(s)
Microglía , Microglía/fisiología , Microglía/metabolismo , Humanos , Animales , Estrés Fisiológico/fisiología , Estrés Psicológico/fisiopatología , Epinefrina/metabolismo , Epinefrina/fisiología , Norepinefrina/metabolismo , Norepinefrina/fisiología , Glucocorticoides/metabolismo , Encéfalo/fisiología , Encéfalo/metabolismo , Fagocitosis/fisiología
8.
PLoS Pathog ; 20(8): e1012413, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39146259

RESUMEN

Microbes exhibit remarkable adaptability to environmental fluctuations. Signaling mechanisms, such as two-component systems and secondary messengers, have long been recognized as critical for sensing and responding to environmental cues. However, recent research has illuminated the potential of a physical adaptation mechanism in signaling-phase separation, which may represent a ubiquitous mechanism for compartmentalizing biochemistry within the cytoplasm in the context of bacteria that frequently lack membrane-bound organelles. This review considers the broader prospect that phase separation may play critical roles as rapid stress sensing and response mechanisms within pathogens. It is well established that weak multivalent interactions between disordered regions, coiled-coils, and other structured domains can form condensates via phase separation and be regulated by specific environmental parameters in some cases. The process of phase separation itself acts as a responsive sensor, influenced by changes in protein concentration, posttranslational modifications, temperature, salts, pH, and oxidative stresses. This environmentally triggered phase separation can, in turn, regulate the functions of recruited biomolecules, providing a rapid response to stressful conditions. As examples, we describe biochemical pathways organized by condensates that are essential for cell physiology and exhibit signaling features. These include proteins that organize and modify the chromosome (Dps, Hu, SSB), regulate the decay, and modification of RNA (RNase E, Hfq, Rho, RNA polymerase), those involved in signal transduction (PopZ, PodJ, and SpmX) and stress response (aggresomes and polyphosphate granules). We also summarize the potential of proteins within pathogens to function as condensates and the potential and challenges in targeting biomolecular condensates for next-generation antimicrobial therapeutics. Together, this review illuminates the emerging significance of biomolecular condensates in microbial signaling, stress responses, and regulation of cell physiology and provides a framework for microbiologists to consider the function of biomolecular condensates in microbial adaptation and response to diverse environmental conditions.


Asunto(s)
Bacterias , Condensados Biomoleculares , Transducción de Señal , Estrés Fisiológico , Transducción de Señal/fisiología , Estrés Fisiológico/fisiología , Bacterias/metabolismo , Condensados Biomoleculares/metabolismo , Proteínas Bacterianas/metabolismo , Fenómenos Fisiológicos Bacterianos
10.
Methods Appl Fluoresc ; 12(4)2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39111331

RESUMEN

Detection of autofluorescence parameters is a useful approach to gain insight into the physiological state of plants and algae, but the effect of reabsorption hinders unambiguous interpretation ofin vivodata. The exceptional morphological features ofNitellopsis obtusamade it possible to measure autofluorescence spectra along single internodal cells and estimate relative changes in autofluorescence intensity in selected spectral regions at room temperatures, avoiding the problems associated with thick or optically dense samples. The response of algal cells to controlled white light and DCMU herbicide was analyzed by monitoring changes in peak FL intensity at 680 nm and in F680/F750 ratio. Determining the association between the selected spectral FL parameters revealed an exponential relationship, which provides a quantitative description of photoinduced changes. The ability to discern the effect of DCMU not only in the autofluorescence spectra of dark-adapted cells, but also in the case of light-adapted cells, and even after certain doses of excess light, suggests that the proposed autofluorescence analysis ofN. obtusamay be useful for detecting external stressors in the field.


Asunto(s)
Luz , Estrés Fisiológico/fisiología , Espectrometría de Fluorescencia/métodos , Fluorescencia , Herbicidas/toxicidad
11.
Arch Oral Biol ; 167: 106051, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39094424

RESUMEN

OBJECTIVES: This study aimed to determine the effects of chronic intermittent hypoxia (CIH) and stress change (SC) on the development of the condyle in mouth breathing rats. DESIGN: A total of 120 4-week-old rats were randomly assigned to one of five groups. The control (Ctrl) group was the blank control and the intermittent nasal obstruction (INO) group was the positive control. Mild CIH (mCIH) and severe CIH (sCIH) groups were developed by adjusting environmental oxygen concentration and monitoring real-time blood oxygen saturation (SpO2). The SC group was developed using INO, increased environmental oxygen concentration, and real-time SpO2 monitoring. Six rats from each group were sacrificed for analysis at 0, 1, 2, or 4 weeks. RESULTS: Similar to the INO group, condyle and mandibular body development in the sCIH group, but not in the mCIH group, was significantly inhibited compared with the Ctrl group. The SC group had inhibited development of the condyle, especially of the posterior zone, but had minimal impact on the growth of the mandible. CONCLUSION: The inhibitory effects of CIH on the development of the condyle and mandibular body were SpO2-dose-dependent. When SC occurred, inhibited development was observed in the posterior zone of condyle but not the whole mandible. These findings provide important insights for targeted interventions that address the consequences of mouth breathing in children.


Asunto(s)
Hipoxia , Cóndilo Mandibular , Animales , Hipoxia/fisiopatología , Ratas , Cóndilo Mandibular/crecimiento & desarrollo , Modelos Animales de Enfermedad , Ratas Sprague-Dawley , Masculino , Respiración por la Boca/fisiopatología , Distribución Aleatoria , Estrés Fisiológico/fisiología , Obstrucción Nasal/fisiopatología , Mandíbula
12.
Physiol Behav ; 285: 114653, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39103027

RESUMEN

Thermal comfort in an office impacts physical health, stress, and productivity. Humidity affects thermal comfort; however, the underlying mechanism remains unclear. This study assessed the influence of humidity on body temperature, thermal comfort, stress, and their relationship in working individuals. Thirteen participants performed three sets of 20-min calculation tasks followed by a 10-min rest in 26 °C or 33 °C with relative humidity (RH) of 30 % or 60 %. Core body temperature (Tcore), mean skin surface temperature (Tskin), and electrocardiogram were continuously recorded. Subjective thermal sensations and comfort were assessed with visual analog scales. Stress level was estimated based on α-amylase activity and immunoglobulin A level in saliva and heart rate variability. Mean Tskin and Tcore elevated at 33 °C with 60 % RH, where warm sensation and thermal discomfort also increased. Heart rate variability reflecting parasympathetic nerve activity decreased. There was a negative linear relationship between weighted body temperature and thermal comfort. However, thermal discomfort was augmented at a given weighted body temperature at 60 % RH. Thus, under indoor working conditions, high humidity may augment thermal discomfort and become a stress factor. Increases in Tskin and Tcore are involved in the mechanism, alongside other factors.


Asunto(s)
Temperatura Corporal , Frecuencia Cardíaca , Humedad , Saliva , Humanos , Masculino , Frecuencia Cardíaca/fisiología , Temperatura Corporal/fisiología , Adulto Joven , Adulto , Saliva/metabolismo , Saliva/química , Femenino , Sensación Térmica/fisiología , Electrocardiografía , alfa-Amilasas/metabolismo , Temperatura Cutánea/fisiología , Estrés Psicológico/fisiopatología , Inmunoglobulina A/metabolismo , Estrés Fisiológico/fisiología , Condiciones de Trabajo
13.
mSystems ; 9(9): e0088424, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39189769

RESUMEN

Metabolic exchange plays a crucial role in shaping microbial community interactions and functions, including the exchange of small molecules such as cofactors. Cofactors are fundamental to enzyme catalytic activities; however, the role of cofactors in microbial stress tolerance is unclear. Here, we constructed a synergistic consortium containing two strains that could efficiently mineralize di-(2-ethylhexyl) phthalate under hyperosmotic stress. Integration of transcriptomic analysis, metabolic profiling, and a genome-scale metabolic model (GEM) facilitated the discovery of the potential mechanism of microbial interactions. Multi-omics analysis revealed that the vitamin B12-dependent methionine-folate cycle could be a key pathway for enhancing the hyperosmotic stress tolerance of synergistic consortium. Further GEM simulations revealed interspecies exchange of S-adenosyl-L-methionine and riboflavin, cofactors needed for vitamin B12 biosynthesis, which was confirmed by in vitro experiments. Overall, we proposed a new mechanism of bacterial hyperosmotic stress tolerance: bacteria might promote the production of vitamin B12 to enhance biofilm formation, and the species collaborate with each other by exchanging cofactors to improve consortium hyperosmotic stress tolerance. These findings offer new insights into the role of cofactors in microbial interactions and stress tolerance and are potentially exploitable for environmental remediation. IMPORTANCE: Metabolic interactions (also known as cross-feeding) are thought to be ubiquitous in microbial communities. Cross-feeding is the basis for many positive interactions (e.g., mutualism) and is a primary driver of microbial community assembly. In this study, a combination of multi-omics analysis and metabolic modeling simulation was used to reveal the metabolic interactions of a synthetic consortium under hyperosmotic stress. Interspecies cofactor exchange was found to promote biofilm formation under hyperosmotic stress. This provides a new perspective for understanding the role of metabolic interactions in microbial communities to enhance environmental adaptation, which is significant for improving the efficiency of production activities and environmental bioremediation.


Asunto(s)
Biopelículas , Biopelículas/crecimiento & desarrollo , Vitamina B 12/metabolismo , Interacciones Microbianas , Estrés Fisiológico/fisiología , Presión Osmótica/fisiología , Bacterias/metabolismo , Bacterias/genética , S-Adenosilmetionina/metabolismo
14.
PeerJ ; 12: e17931, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39184382

RESUMEN

Background: Drought is the most significant factor limiting maize production, given that maize is a crop with a high water demand. Therefore, studies investigating the mechanisms underlying the drought tolerance of maize are of great importance. There are no studies comparing drought tolerance among economically important subspecies of maize. This study aimed to reveal the differences between the physio-biochemical, enzymatic, and molecular mechanisms of drought tolerance in dent (Zea mays indentata), popcorn (Zea mays everta), and sugar (Zea mays saccharata) maize under control (no-stress), moderate, and severe drought stress. Methods: Three distinct irrigation regimes were employed to assess the impact of varying levels of drought stress on maize plants at the V14 growth stage. These included normal irrigation (80% field capacity), moderate drought (50% field capacity), and severe drought (30% field capacity). All plants were grown under controlled conditions. The following parameters were analyzed: leaf relative water content (RWC), loss of turgidity (LOT), proline (PRO) and soluble protein (SPR) contents, membrane durability index (MDI), malondialdehyde (MDA), and hydrogen peroxide (H2O2) content, the antioxidant enzyme activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT). Additionally, the expression of heat shock proteins (HSPs) was examined at the transcriptional and translational levels. Results: The effects of severe drought were more pronounced in sugar maize, which had a relatively high loss of RWC and turgor, membrane damage, enzyme activities, and HSP90 gene expression. Dent maize, which is capable of maintaining its RWC and turgor in both moderate and severe droughts, and employs its defense mechanism effectively by maintaining antioxidant enzyme activities at a certain level despite less MDA and H2O2 accumulation, exhibited relatively high drought tolerance. Despite the high levels of MDA and H2O2 in popcorn maize, the up-regulation of antioxidant enzyme activities and HSP70 gene and protein expression indicated that the drought coping mechanism is activated. In particular, the positive correlation of HSP70 with PRO and HSP90 with enzyme activities is a significant result for studies examining the relationships between HSPs and other stress response systems. The discrepancies between the transcriptional and translational findings provide an opportunity for more comprehensive investigations into the role of HSPs in stress conditions.


Asunto(s)
Sequías , Zea mays , Zea mays/genética , Estrés Fisiológico/genética , Estrés Fisiológico/fisiología , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Hojas de la Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Agua/metabolismo , Especificidad de la Especie , Antioxidantes/metabolismo
15.
Adv Neurobiol ; 37: 333-342, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39207700

RESUMEN

Microglia are highly dynamic cells and acquire different activation states to modulate their multiple functions, which are tightly regulated by the central nervous system microenvironment in which they reside. In response to stress, that is to the appearance of non-physiological signals in their vicinity, microglia will adapt their function in order to promote a return to brain homeostasis. However, when these stress signals are chronically present, microglial response may not be adapted and lead to the establishment of a pathological state. The aim of this book chapter is to examine the substantial literature around the ability of acute and chronic stressors to affect microglial structure and function, with a special focus on psychosocial and nutritional stresses. We also discuss the molecular mechanisms known to date that explain the link between exposure to stressors and microglial activation.


Asunto(s)
Microglía , Estrés Psicológico , Microglía/metabolismo , Microglía/patología , Humanos , Estrés Psicológico/metabolismo , Animales , Encéfalo , Estrés Fisiológico/fisiología
16.
PeerJ ; 12: e17847, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39157773

RESUMEN

Amphibians, with their unique physiology and habitat requirements, are especially vulnerable to changes in environmental temperatures. While the activation of the physiological stress response can help to mitigate the impact of such habitat alteration, chronic production of elevated glucocorticoid levels can be deleterious in nature. There is no empirical evidence indicating the physiological response of African amphibians to temperature changes, where individuals are unable to emigrate away from potential stressors. To rectify this, we used the edible bullfrog (Pyxicephalus edulis) as a model species to determine the effect of elevated temperature on the adrenocortical response of the species using a recently established matrix. While a control group was kept at a constant temperature (25 °C) throughout the study period, an experimental group was exposed to control (25 °C) and elevated temperatures (30 °C). Mucous swabs were collected throughout the study period to determine dermal glucocorticoid (dGC) concentrations, as a proxy for physiological stress. In addition to this, individual body mass measurements were collected. The results showed that individuals within the experimental group who experienced increased temperatures had significantly elevated dGC levels compared to the control animals. Furthermore, there was a significant difference in the percentage mass change between experimental and control animals . These findings indicate the physiological sensitivity of the edible bullfrog to a thermal stressor in captivity. While this study shows the importance of proper amphibian management within the captive environment, it also highlights the coming danger of global climate change to this and similar amphibian species.


Asunto(s)
Glucocorticoides , Calor , Estrés Fisiológico , Animales , Calor/efectos adversos , Glucocorticoides/metabolismo , Estrés Fisiológico/fisiología , Anuros/fisiología , Anuros/metabolismo
17.
Mil Med ; 189(Supplement_3): 196-204, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39160861

RESUMEN

INTRODUCTION: Winter warfare training (WWT) is a critical component of military training that trains warfighters to operate effectively in extreme environments impacted by snow and mountainous terrain. These environmental factors can exacerbate the disruption to the hormone milieu associated with operating in multi-stressor settings. To date, there is limited research on the physiological responses and adaptations that occur in elite military populations training in arduous environments. The purpose of this study was to quantify hormone responses and adaptations in operators throughout WWT. MATERIALS AND METHODS: Participants engaged in baseline laboratory metrics at their home station, Fort Carson, located in Colorado (CO) prior to WWT, for one week in Montana (MT) and one week in Alaska (AK). WWT periods were separated by approximately one month. Blood was collected upon wake at baseline (CO) and on the first and last day of WWT at each location (MT and AK). Plasma was analyzed for stress, metabolic, and growth-related hormones via enzyme-linked immunoassay (ELISA). Sleep quality was assessed via the Pittsburg Sleep Quality Index (PSQI) at baseline (CO) and on the first day of training in MT and AK. Cognitive function was evaluated using the Defense Automated Neurobehavioral Assessment (DANA) at baseline (CO) and on the first and last day of WWT in both MT and AK. RESULTS: Fourteen US Army operators in 10th Special Forces Group (SFG) Operational Detachment participated in winter warfare training (WWT; age: 31.5 years; 95%CI[28.1, 34.3]; height: 180.6 cm; 95%CI[177.3, 183.4]; weight: 87.4 kg.; 95%CI[80.6, 97.7]; body fat: 18.9%; 95%CI[13.7, 23.1]; male: n=13; female: n=1). Plasma adrenocorticotropic hormone (ACTH) levels increased from baseline (19.9 pg/mL; 95%CI[8.6, 24.2])  to pre-WWT (26.9 pg/mL; 95%CI [16.2, 37]; p=0.004), decreased from pre-  (26.9 pg/mL; 95%CI [16.2, 37]) to post-WWT in MT (22.3 pg/mL; 95% CI [8, 23.7]; p=0.004;), and increased from pre-  (25 pg/mL; 95%CI[ 28.4) to post-WWT (36.6 pg/mL; 95%CI [17.9, 48.9]) in AK (p=0.005). Plasma cortisol levels decreased from pre- (174 ng/mL; 95%CI[106.2, 233.6])  to post-WWT (94.5 ng/mL; 95%CI[54.8, 101.7]) in MT (p=0.001) and, conversely, increased from pre- (123.1 ng/mL; 95%CI[97.5, 143.9]) to post-WWT  (162.8 ng/mL; 95%CI[128, 216.7]) in AK (p<0.001). Alterations in growth-related hormones (insulin-like growth factor 1 [IGF-1], insulin-like growth factor binding protein 3 [IGFBP-3],  and sex hormone binding globulin [SHBG]) were observed throughout WWT (p<0.05). The Total Testosterone / Cortisol ratio (TT / CORT; molar ratio) was lower pre-WWT in MT (0.04; 95%CI[0.01,0.04) compared to baseline in CO (0.07; 95%CI[0.04, 0.07]; p=0.042). Triiodothyronine (T3) levels increased from pre-  (101.7 ng/dL; 95%CI[93.7, 110.4]) to post-WWT  (117.8 ng/dL; 95%CI[105.1, 129.4]) in MT (p=0.042). No differences in sleep quality were reported between locations (CO, MT, and AK). Alterations in cognitive function were exhibited between locations and during WWT in both MT and AK (p<0.05). CONCLUSIONS: Over the course of WWT, elite operators experienced alterations in stress, metabolic, and growth-related hormones, as well as cognitive performance. The increase in stress hormones (i.e., ACTH and cortisol) and reduction in cognitive performance following training in AK are suggestive of heightened physiological strain, despite similarities in physical workload, self-reported sleep quality, and access to nutrition. The variation in hormone levels documented between MT and AK may stem from differences in environmental factors, such as lower temperatures and harsh terrain. Further research is warranted to provide more information on the combined effects of military training in extreme environments on operator health and performance.


Asunto(s)
Personal Militar , Humanos , Masculino , Adulto , Femenino , Colorado , Personal Militar/estadística & datos numéricos , Montana , Alaska , Hidrocortisona/sangre , Hidrocortisona/análisis , Estrés Fisiológico/fisiología , Estaciones del Año , Hormona Adrenocorticotrópica/sangre
18.
Braz J Biol ; 84: e286121, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39166696

RESUMEN

Addressing water scarcity and the need for high-quality forage in arid regions necessitates the development of efficient irrigation techniques. This study assesses the impact of various irrigation methods on the performance and irrigation water-use efficiency (IWUE) of sorghum cultivars under water-deficit conditions in a semi-arid region of Iran during the 2019 and 2020 cropping seasons. Three irrigation methods-variable alternate furrow irrigation (AFI), fixed alternate furrow irrigation (FFI), and conventional furrow irrigation (CFI)-were evaluated alongside three levels of drought stress (severe stress: I50, moderate stress: I75, and full irrigation: I100) and two sorghum cultivars. The results indicated that increasing drought stress, as well as the transition from CFI to AFI and FFI, led to reductions in metabolizable energy yield (MEY), plant height, cellulose, hemicellulose, and lignin. Conversely, there were increases in leaf-to-stem ratio, digestible organic matter, metabolizable energy content, crude protein content, and IWUE for metabolizable energy production (IWUEME). The highest MEY (211.68 GJ ha-1) was recorded under CFI×I100, albeit at the expense of maximum water consumption (7261 m3 ha-1). Meanwhile, the AFI×I50 and FFI×I50 treatments exhibited the highest IWUEME (44.46 MJ m-3) and metabolizable energy content (8.736 MJ kg-1), respectively, while conserving over 60% of water. Hybrid Speedfeed outperformed in forage yield and IWUEME, while cultivar Pegah excelled in forage quality. Transitioning from CFI to AFI or FFI resulted in decreased forage yield but improved forage quality and IWUEME. Principal component analysis revealed that leaf-to-stem ratio and plant height serve as effective indicators for assessing the nutritive value and forage yield of sorghum, respectively. Considering the overall results, cultivating the hybrid Speedfeed under AFI×I75 conditions is recommended for optimal water utilization, achieving satisfactory forage yield and quality, and enhancing IWUE.


Asunto(s)
Riego Agrícola , Sequías , Valor Nutritivo , Sorghum , Sorghum/fisiología , Sorghum/química , Riego Agrícola/métodos , Irán , Estaciones del Año , Agua/análisis , Estrés Fisiológico/fisiología
19.
Artículo en Ruso | MEDLINE | ID: mdl-39169583

RESUMEN

BACKGROUND: Highly traumatic surgical correction of craniosynostosis (CS) is usually followed by severe postoperative period and high risk of complications. Surgical stress response (SSR) is an important and often neglected cause of severe early postoperative period. OBJECTIVE: To compare clinical and laboratory parameters of SSR in children who underwent various surgeries for CS. MATERIAL AND METHODS: The study included 63 patients aged 7.02±4.12 months. All ones underwent surgery for CS between October 2021 and June 2022. We analyzed clinical and laboratory markers of SSR, as well as correlation with severity of surgical stress. RESULTS: No surgical complications were observed. There were postoperative complications in 12 (19.0%) cases including febrile fever in 9 (14.3%) patients, severe pain and edematous syndromes with prolonged hospital-stay in 3 (4.8%) cases. Significant correlations were revealed between severity of surgical stress and certain laboratory markers (CRP, ACTH, T3, insulin, HOMA-IR). The last ones characterized SSR severity. Patients with high scores of stress response demonstrated more severe course of early postoperative period. CONCLUSION: Surgical stress scale makes it possible to predict early postoperative period and optimize patient management. Lower severity of surgical stress response following endoscopic interventions is another reason for the wider use of low-traumatic surgical methods in pediatric neurosurgery.


Asunto(s)
Craneosinostosis , Complicaciones Posoperatorias , Estrés Fisiológico , Humanos , Craneosinostosis/cirugía , Craneosinostosis/sangre , Lactante , Masculino , Femenino , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/diagnóstico , Estudios Prospectivos , Estrés Fisiológico/fisiología , Preescolar , Biomarcadores/sangre
20.
Pediatr Surg Int ; 40(1): 216, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39103636

RESUMEN

PURPOSE: Salivary cortisol (SalC) and low to high pulse ratio (LHR) were used for evaluating perioperative stresses in children. METHODS: Children aged 6 months-16 years having elective general (thoracic/abdominal) or minor (open/minimally invasive: MI) procedures underwent pulse monitoring during AM (08:00-12:00) and PM (17:00-21:00) saliva collections from the day before surgery (S-1) to 3 days after surgery (S + 3). SalC/LHR were correlated with age, sex, caregiver attendance, operative time, and surgical site/approach using mixed model analysis and face/numeric pain rating scales (FRS/NRS). RESULTS: Mean ages (years): minor-open (n = 31) 4.7 ± 2.0, thoracic-open (n = 2) 8.7 ± 4.9, thoracic-MI (n = 6) 9.6 ± 6.1, abdominal-open (n = 14) 4.3 ± 4.1, and abdominal-MI (n = 32) 8.0 ± 5.0. Postoperative SalC increased rapidly and decreased to preoperative levels by S + 3 (p < 0.001). LHR increased slightly without decreasing (p = 0.038). SalC correlated positively with operative time (p = 0.036) and open surgery (p = 0.0057), and negatively with age (p < 0.0001) and caregiver attendance (p < 0.001). SalC correlated positively with FRS (n = 51) at S + 2(PM) (p = 0.023), S + 3(AM) (p < 0.001), S + 3(PM) (p = 0.012) and NRS (n = 34) at S + 1(AM) (p = 0.031), S + 3(AM) (p < 0.044). LHR positively correlated with age (p = 0.0072), female sex (p = 0.0047), and caregiver attendance (p = 0.0026). Postoperative SalC after robotic-assisted MI was significantly lower than after open surgery at S + 2(AM) (p = 0.020). CONCLUSIONS: SalC correlated with pain. Caregiver attendance effectively alleviated stress.


Asunto(s)
Hidrocortisona , Saliva , Humanos , Femenino , Niño , Masculino , Saliva/metabolismo , Saliva/química , Adolescente , Preescolar , Hidrocortisona/metabolismo , Hidrocortisona/análisis , Lactante , Periodo Perioperatorio , Estrés Fisiológico/fisiología , Sistema Nervioso Autónomo/fisiopatología , Sistema Nervioso Autónomo/metabolismo , Estrés Psicológico/metabolismo
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