Episodes Of Stress Research Articles

Sex Differences in the Inflammatory Consequences of Stress: Implications for Pharmacotherapy.

Women are at significantly greater risk of developing stress-related disorders such as depression. The increased risk begins during puberty and continues throughout life until menopause, suggesting a role for ovarian hormones in this increased susceptibility. Importantly, inflammation has been gaining momentum in its role in the pathogenesis of depression. Herein, clinical and preclinical studies have been reviewed to better understand how sex differences within the immune system may contribute to exaggerated risk of depression in females. First, studies that investigate the ability of psychologic stress episodes to engage the inflammatory systems both in the brain and periphery are reviewed with a special focus on sex-specific effects. Moreover, studies are discussed that identify whether imbalanced inflammatory milieu contributes to the development of depression in males versus females and whether these effects are regulated by estradiol. Importantly, we propose a locus coeruleus-norepinephrine-cytokine circuit as a conduit through which stress could increase stress susceptibly in females. Finally, the anti-inflammatory capacity of traditional and nontraditional antidepressants is investigated, with the goal of providing a better understanding of pharmacotherapeutics to enhance strategies to personalize antidepressant treatments between the sexes. The studies reviewed herein strongly support the need for further studies to elucidate whether females are especially sensitive to anti-inflammatory compounds as adjuvants to traditional therapies. SIGNIFICANCE STATEMENT: Women have hve an increased risk of developing stress-related disorders such as depression. In this review, literature from clinical and preclinical studies are integrated to define sex differences in stress-induced inflammatory responses as a potential source for the etiology of sex differences in depressive disorders. Moreover, the anti-inflammatory capacity of traditional and nontraditional antidepressants is reviewed to inform on potential pharmacotherapeutic strategies to personalize antidepressant therapy in a sex-dependent manner.

Impact of acute mental stress on segmental arterial stiffness

It has been reported that acute brief episodes of mental stress (MS) result in a prolonged increase in carotid-femoral pulse wave velocity (cfPWV), an index of aortic stiffness. However, whether acute MS also impacts arterial stiffness in other segments is unclear. The present study aimed to examine the impact of acute MS on segmental arterial stiffness. In the main experiment, 17 young male subjects (mean age, 20.1 ± 0.7years) performed a 5-min MS and control (CON) task in a random order. Pulse wave velocity (PWV) from the heart to the brachium (hbPWV) and the ankle (haPWV), PWV between the brachial artery and the ankle (baPWV), and the cardio-ankle vascular index (CAVI) were simultaneously measured at baseline and 5, 15, and 30min after the task. Compared to baseline values, hbPWV, baPWV, haPWV, and CAVI significantly increased until 30min after the MS task, whereas these variables did not significantly change following the CON task. At 5 and 30min after the MS task, percentage changes from baseline were significantly higher in hbPWV (+ 5.2 ± 4.4 and 6.6 ± 4.9%) than in baPWV (+ 2.2 ± 2.1 and 2.2 ± 2.0%) or haPWV (+ 3.6 ± 2.6 and 4.3 ± 2.9%) and were also significantly lower in baPWV than in haPWV. These findings suggest that acute MS elicits an increase in arterial stiffness in various segments and this arterial stiffening is not uniform among the segments.

Reproductive status impact on tau phosphorylation induced by chronic stress

Sex and exposure to chronic stress have been identified as risk factors for developing Alzheimer's disease (AD). Although AD has been demonstrated to be more prevalent in females, sex is often overlooked in research studies, likely due to the complexity of the hormonal status. In female rats, the reproductive status can modulate the well-known increase in tau phosphorylation (pTau) caused by the exposure to acute physical and psychological stressors. To test the hypothesis that reproductive status can impact hippocampal pTau induced by chronic stress, cohorts of virgin, lactating (4–5 days pp), and post-maternal (1-month post-weaned) rats were subjected to a daily 30-min episode of restraint stress for 14 days and were sacrificed either 20 min or 24 h after their last stress/handling episode. Western blot analysis of two well-characterized AD-relevant pTau epitopes (AT8 and PHF-1) and upstream pTau mechanisms (e.g. GSK3β) analysis, showed that stressed post-maternal rats have increased pTau in comparison to stressed lactating rats 20 min after their last stress episode. Furthermore, an increase in pTau was also seen 24 h after the last stress episode in stressed post-maternal rats in comparison to their non-stressed controls in the detergent-soluble fraction. GSK3 analysis showed an increase in total levels of GSK3β in virgin rats and an increase of inactive levels of GSK3β in post-maternal rats, which suggests a different stress response in pTau after the rat has gone through the maternal experience. Interestingly, post-maternal rats also presented the more variability in their estrous cycles in response to stress. Besides no differences in pTau, non-stressed lactating rats showed an increase in inactive GSK3β 24 h after the last handling episode. Immunohistochemical detection of the PHF-1 epitope revealed increased pTau in the CA4/hilar subfield of the hippocampus of virgin and post-maternal rats exposed to chronic stress shortly after their last stress episode. Overall, lactating rats remained unresponsive to chronic restraint stress. These results suggest increased sensitivity of the virgin and post-maternal rats to hippocampal stress-induced pTau with chronic restraint stress compared to lactating rats. Because no differences were detected in response to stress by lactating rats and an exaggerated response was observed in post-maternal rats, current results support the hypothesis that lactation affects tau processing in the brain of the female.

The efficacy of steroids in reducing morbidity and mortality from extreme hyperthermia and heatstroke—A systematic review

Severe hyperthermia from classical or exertional heatstroke, or from drug ingestion or other noninfective pyrogens, is associated with a high mortality and morbidity. A systemic pro‐inflammatory response occurs during heatstroke, characterized by elevated cytokines with endotoxemia from elevated lipopolysaccharide (LPS) levels. Corticosteroids reduce LPS and cytokine levels, suggesting that they may improve outcome. A systematic review searching Embase, MEDLINE, and PubMed from the earliest date available until September 2019 was conducted, according to the PRISMA guidelines, with five papers identified. In four studies, systemic steroids administered before or at the onset of heat stress improved mortality or reduced organ dysfunction. Survival time was greatest when steroid administration preceded heat stress. In one study, a nonsignificant increase in mortality was seen. A dose response was observed, with higher doses extending survival time. Animal studies suggest that steroids improve mortality and/or organ dysfunction after an episode of heat stress or extreme hyperthermia.

Corticosterone after acute stress prevents the delayed effects on the amygdala.

Even a single 2-hour episode of immobilization stress is known to trigger anxiety-like behavior and increase spine-density in the basolateral amygdala (BLA) of rats 10 days later. This delayed build-up of morphological and behavioral effects offers a stress-free time window of intervention after acute stress, which we used to test a protective role for glucocorticoids against stress. We observed that post-stress corticosterone, given 1 day after acute stress in drinking water, reversed enhanced anxiety-like behavior 10 days later. Quantification of spine-density on Golgi-stained BLA principal neurons showed that the same intervention also prevented the increase in spine numbers in the amygdala, at the same delayed time-point. Further, stress elevated serum corticosterone levels in rats that received vehicle in the drinking water. However, when stress was followed 24 h later by corticosterone in the drinking water, the surge in corticosterone was prevented. Together, these observations suggest that corticosterone, delivered through drinking water even 24 h after acute stress, is capable of reversing the delayed enhancing effects on BLA synaptic connectivity and anxiety-like behavior. Strikingly, although the immobilization-induced surge in corticosterone by itself has delayed detrimental effects on amygdalar structure and function, there exists a window of opportunity even after stress to mitigate its impact with a second surge of exogenously administered corticosterone. This provides a framework in the amygdala for analyzing how the initial physiological and endocrine processes triggered by traumatic stress eventually give rise to debilitating emotional symptoms, as well as the protective effects of glucocorticoids against their development.

Liquen plano oral. Reporte de un caso y revisión de la literatura

El liquen plano oral (LPO) es una enfermedad mucocutánea crónica, de carácter inflamatorio, etiología desconocida y naturaleza autoinmune, en la que se produce una agresión por parte de los linfocitos T dirigida frente a las células basales del epitelio de la mucosa oral. El diagnóstico del LPO debe basarse en la observación clínica y confirmarse con la descripción de las características histopatológicas. Se presenta caso clínico de paciente femenina de 39 años de edad que acudió a consulta odontológica al Servicio de Estomatología de la Escuela de Odontología, de la Facultad de Ciencias de la Salud, Universidad Católica de Córdoba, por presentar múltiples lesiones blancas en la cavidad bucal de 1 año de evolución. La paciente manifiesta episodios de stress. Se realizó biopsia de tipo incisional y se envió a anatomía patológica donde se confirmó el diagnóstico de Liquen Plano Oral.

Assessing weaning stress – Relations between enamel hypoplasia, δ18O and δ13C values in human teeth obtained from early modern cemeteries in Wroclaw, Poland

ObjectivesThe aim of this paper is to assess linear enamel hypoplasia (LEH) on canines of adults from early modern Wroclaw cemeteries to compare δ13C and δ18O values in enamel formed before, during and after LEH formation, and to attempt to find a link between the selected indicators of the weaning process. Material and methods15 permanent canines with visible LEH were selected for analysis. Age at LEH formation was estimated using the Reid and Dean method. The perikymata count was used to estimate the duration of LEH formation. Incremental stable oxygen and carbon isotopes analysis was performed on tooth enamel to infer stress related to weaning and dietary patterns. Kruskal–Wallis ANOVA, Mann–Whitney U test and Spearman correlation were used in statistical inference. ResultsThe average age of LEH formation was 3.14 years, with an average duration of 111 days. Stable carbon isotope values consistently increase in 73% of the individuals sampled. The values of δ18O do not show a dominant pattern. The average value of δ13C increases over the time of enamel formation. The δ13C values collected below LEH were negatively correlated with δ18O values and the duration of LEH termination. ConclusionsMarking of carbon and oxygen isotopes indicates different stages of weaning. Advancements in diet change (determined by higher δ13C) corresponds with faster recovery after physiological stress episode. There is no evidence for different breastfeeding models between distinct parishes in early modern Wroclaw.

Evaluating financial stress indicators: evidence from Indian data

Purpose The purpose of this study is to assess alternative financial stress indicators for India in terms of tracing crisis events, mapping with the business cycle and the macroeconomic effect of stress indices. Design/methodology/approach The study constructs the composite indicator of systemic stress of Hollo, Kremer and Lo Duca (2012) for India using two different methods for computing time-varying cross-correlation matrix, namely, exponentially weighted moving average (EWMA) and dynamic conditional correlation-generalized autoregressive conditional heteroscedasticity (DCC-GARCH). The derived indices are evaluated with widely used, equal variance and principal component weighting indices in terms of tracing stress events, mapping with the business cycles and the macroeconomic effect. For this purpose, the study identifies various episodes of financial stress and uses the business cycle dates in the sample covering from January 2001 to October 2018. Findings The results suggest that stress indices based on EWMA and DCC-GARCH accurately identify the well-known stress periods and capture the recession dates and show an adverse effect on economic activity. Primarily, the DCC-GARCH-based stress index emerges as a better indicator of stress because it efficiently locates all the major-minor events, traces the build-up of stress and reverts to the normal level during stable times. Practical implications The DCC-GARCH-based stress index is a very useful indicator for policymakers in regularly monitoring India’s financial conditions and providing timely identification of systemic stress to avoid adverse repercussion effects of the financial crisis. Originality/value The 2007–2008 financial crisis and subsequent recurrent instability in the financial markets highlighted the requirement for an appropriate financial stress indicator for a timely assessment of the system-wide financial stress. To the authors’ knowledge, this is the first study that incorporates the systemic nature of financial stress in the construction of stress indices for India and provides a holistic evaluation of the financial stress from an emerging country’s perspective.

Paleopathological peculiarities of the population of timber-grave (Srubnaya) culture of the Late Bronze Age originating from the burials of Archedino-Chernushensky Kurgan group

Skeletal remains from the burials of timber-grave period of the Late Bronze Age originating from kurgans of the Archedino-Chernushensky group served as the material for this research. The archaeological monument is located in the territory of the Frolovsky Municipal District of Volgograd Oblast. The remains of 12 individuals (6 adults, 4 children, and 2 adolescents) were explored. In the course of this research, the author applied the method of account for the occurrence of discretely varying traits on the skull and bones of postcranial skeleton, as well as evaluation program for dissemination of pathological characteristic developed by the national researchers A. A. Movsesyan, E. V. Pererva, A. P. Buzhilova. The archaeological explorations of group Archedino-Chernushensky Kurgan group were carried out in 2020. Therefore, the acquired anthropological materials are introduced into the scientific discourse for the first time. The author was able to establish that the equal number of children and adult burials can be attributed to timber-grave period. The examined skeletal remains of the Late Bronze Age of the Lower Volga Region demonstrate the signs of episodic stress (enamel hypoplasia) and distribution of diseases related to the deficiency of microelements in the body (porosis of the diaphysis in individuals who did not reach the age of puberty). The records of such type of deviations on anthropological materials of deviations indicates chronic stress associated with systematic occurrences of famine, which is natural for the population of the Late Bronze Age of the Lower Volga Region, who were involved in mixed farming. The excavations reveal the series of injuries of household and battle nature among adult population. The prevalent burial method of timber-grave culture Archedino-Chernushensky Kurgan group of appears to be the cremation ritual.   

Disentangling levels of mother–infant neuroendocrine attunement and longitudinal relations with maternal risk and protective factors

Scientific understanding of mother-infant HPA axis attunement has been limited by discrepant methods for assessing attunement that often conflate different levels of association. We sought to refine the conceptualization of attunement by investigating whether mother-infant cortisol attunement exists as coupling of response trajectories within an acute stress episode, separate from shared developmental patterns and/or overall dyadic similarity in cortisol levels, and whether the degree of attunement depends on within- or between-dyad differences in maternal risk and protective factors. We examined these questions using a longitudinal study with mother/infant salivary cortisol during dyadic stressors at 6, 12, and 18months postnatal. A three-level hierarchical linear model showed that sample-wide associations between mother and infant cortisol were not significant at any level, suggesting normative lack of attunement; however, there was significant variability in degree of attunement across dyads. Concurrent levels of family resources and social support satisfaction predicted lower mother-infant cortisol attunement within the session, and overall (mean) parenting stress predicted the opposite. Follow-up analyses showed this was typically due to an increase in infants' (but not their mothers') within-session cortisol response slopes with increasing support and decreasing stress. Implications for the role of mother-infant cortisol attunement in intergenerational stress transmission are discussed.

Productivity and heat-stress tolerance in Canadian poplar (Populus × canadensis Moench) clones with different ecological optimum

Cultivation of fast growing poplar (Populus sp.) clones represents an effective means for reaching the 2020 target of the EU-28 renewable energy production. However, considering the continuous climate change, their growth can be markedly affected by summer heat stress episodes in Slovakia. Therefore, in this work two Canadian poplar (Populus × canadensis Moench) clones of different ecological optimum, ‘Gigant' and ‘Pannonia', were investigated in respect of productivity and heat stress tolerance. After three-year cultivation, tree height in the clone ‘Gigant' was 8.9 m, breast trunk diameter 9.3 cm and trunk volume 0.021 m3 compared to 7.9 m, 7.0 cm and 0.012 m3 in clone ‘Pannonia' (despite of relatively more stable trunk growth rate in summer). Trunks of the latter clone contained 12% bark (vs. 10% in ‘Gigant'), 1.5% ash in the wood (vs. 3%) and showed significantly larger wood density (440 vs. 380 kg m−3) but lower wood free energy content (14.5 vs. 16 MJ kg−1). Both of clones were proved to be diploids (2x). Clone ‘Pannonia' exhibited larger heat stress tolerance, as tested in leaves of different developmental stage exposed to 40 °C using chlorophyll fluorescence technique (decreasing from mature to juvenile leaves), lower specific leaf area and higher leaf carotenoid and cytokinin (particularly BAP derivatives) concentration. In spite of lower heat stress tolerance and higher ash content, clone ‘Gigant' showed larger productivity than clone ‘Pannonia', suggesting potential of the latter for cultivation in much more stressful conditions.

Systemic signaling during abiotic stress combination in plants.

Extreme environmental conditions, such as heat, salinity, and decreased water availability, can have a devastating impact on plant growth and productivity, potentially resulting in the collapse of entire ecosystems. Stress-induced systemic signaling and systemic acquired acclimation play canonical roles in plant survival during episodes of environmental stress. Recent studies revealed that in response to a single abiotic stress, applied to a single leaf, plants mount a comprehensive stress-specific systemic response that includes the accumulation of many different stress-specific transcripts and metabolites, as well as a coordinated stress-specific whole-plant stomatal response. However, in nature plants are routinely subjected to a combination of two or more different abiotic stresses, each potentially triggering its own stress-specific systemic response, highlighting a new fundamental question in plant biology: are plants capable of integrating two different systemic signals simultaneously generated during conditions of stress combination? Here we show that plants can integrate two different systemic signals simultaneously generated during stress combination, and that the manner in which plants sense the different stresses that trigger these signals (i.e., at the same or different parts of the plant) makes a significant difference in how fast and efficient they induce systemic reactive oxygen species (ROS) signals; transcriptomic, hormonal, and stomatal responses; as well as plant acclimation. Our results shed light on how plants acclimate to their environment and survive a combination of different abiotic stresses. In addition, they highlight a key role for systemic ROS signals in coordinating the response of different leaves to stress.

New insights on repeated acoustic injury: Augmentation of cochlear susceptibility and inflammatory reaction resultant of prior acoustic injury

In industrial and military settings, individuals who suffer from one episode of acoustic trauma are likely to sustain another episode of acoustic stress, creating an opportunity for a potential interaction between the two stress conditions. We previously demonstrated that acoustic overstimulation perturbs the cochlear immune environment. However, how the cochlear immune system responds to repeated acoustic overstimulation is unknown. Here, we used a mouse model to investigate the cochlear immune response to repeated stress. We reveal that exposure to an intense noise at 120 dB SPL for 1 h activates the cochlear immune response in a time-dependent fashion with substantial expansion and activation of the macrophage population in the cochlea at 2-days post-exposure. At 20-days post-exposure, the number and pro-inflammatory phenotypes of cochlear macrophages have significantly subsided, but have yet to return to homeostatic levels. Monocytes with anti-inflammatory phenotypes are recruited into the cochlea. With the presence of this residual immune activation, a second exposure to the same noise provokes an exaggerated inflammatory response as evidenced by exacerbated maturation of macrophages. Furthermore, the second noise causes greater sensory cell pathogenesis. Unlike the first noise-induced damage that occurs mainly between 0 and 2 days post-exposure, the second noise-induced damage occurs more frequently between 2 and 20 days post-exposure, the period when secondary damage takes place. These observations suggest that repeated acoustic overstimulation exacerbates cochlear inflammation and secondary sensory cell pathogenesis. Together, our results suggest that the cochlear immune system plays an important role in modulating cochlear responses to repeated acoustic stress.

SAT-641 Self-Reported Psychological Stress and Glucose Variability in Type 1 Diabetes on Sensor Augmented Pump over 5 Weeks

Introduction: Patients and their families and medical providers have assumed that psychologic stress impacts glucose control in T1D (Type 1 Diabetes) though studies providing confirmatory evidence in real world settings are, to our knowledge, lacking. We hypothesized that self-reported psychologic stress worsens glucose control in T1D. Method: We studied 20 adults with T1D on continuous glucose monitor (CGM), sensor augmented insulin pump (SAP) prospectively at 2 clinical research centers. Patients reported psychological stress through stress diaries for 5 weeks on a severity scale of 1-7 using hard copy logs including time of onset and offset of stress and severity. For analytic purpose, grades 1-4 are classified as mild and grades 5-7 as severe. Results: Baseline characteristics were age 44.9±15.0 years, F/M 12/8, HbA1c 6.8 ± 0.7%, and diabetes duration of 22.9±15.9 years. We analyzed glucose variability during days of stress versus days without stress. During a 24 hour period, patients experienced less hypoglycemia during days with stress versus days without stress (p value 0.03). During the 5 week period, patients reported 23 ± 19.5 events. We analyzed the impact of self-reported stress on CGM data streams after excluding stress events associated with missing CGM data, nocturnal events (from 12 MN to 6 AM, too few events) and events for which subjects did not provide duration of stress. Thus, we analyzed 19.5 ± 17 events per patient from 6AM to 12MN. From 6 AM to 12 MN, the episodes lasted 179 ± 255 minutes with 83 % episodes being mild/moderate and 17% moderate/ severe. Number of CGM readings during daytime stress episodes were 717± 1120 compared to 8768± 1238 during non-stress periods. Impact of stress from 6 AM to 12 MN (Mid-Night) on CGM glucose was analyzed using matched paired t test. Mean glucose (160.6±41.9 vs 148.3± 28.6) and SD (53.2 ±17.7 vs 56.1±14.6) did not show a difference; however % of time spent below 70 mg/dl was less (4 ± 5) in patients during stressful periods compared to times without stress (6.3± 5.5, P value 0.02). Conclusions: To our knowledge, this is the first study attempting to analyze the impact of self-reported stress using daily stress diaries on CGM data streams in T1D patients on SAP. The study revealed significant challenges experienced by patients in reporting adequate data. Self-reported stress was not associated with hyperglycemia. However, days of self-reported stress and periods during patients reported stress were characterized by less hypoglycemia on CGM data streams.

Dehydration-associated chronic kidney disease: a novel case of kidney failure in China

BackgroundMesoamerican nephropathy (MeN) is a pattern of chronic kidney disease (CKD) prevalent among Central American men who work in agriculture, and its underlying cause has not been elucidated. Currently, experts hypothesize that MeN is related to repeated episodes of occupational heat stress leading to water loss and hence it is also called dehydration-associated CKD.Case presentationWe report a case of a 40-year-old man, whose first admission to Peking Union Medical College Hospital was due to acute kidney injury (AKI). The clinical and pathological processes were consistent with acute tubular necrosis (ATN). However, after full recovery, CKD developed 1 year later. The second renal biopsy showed characteristics of ischemic renal disease but there was no evidence of vascular disease. It is worth noting that the patient had been taking part in long-distance running without drinking adequate water for years, which would have markedly decrease his renal blood flow. Thus, this patient may have developed chronic dehydration-associated kidney disease sharing the similar etiology of MeN.ConclusionsWe report here a case of dehydration-associated CKD in a Chinese patient which shared similar etiology to MeN. Even in non-agricultural areas, this etiology of CKD should be noted to obtain a relevant history and prompt diagnosis.

Endogenous oxytocin is essential for the buffering effects of pair housing against the increase in cocaine reward induced by social stress

Social factors have a dual influence on addictive disorders. While social defeat stress in rodents increases the response to drug reward, positive social conditions, such as pair housing, increase stress resilience. The objective of the present study was to confirm whether oxytocin (OT) mediates this social buffering. To this end, male mice were housed in pairs and administered the OT receptor antagonist atosiban prior to each stress episode or for ten days after the stress protocol. The response to cocaine was assessed using a conditioned place preference paradigm. Our results confirmed that OT activity mediates the protective effect of pair housing and highlights its therapeutic potential.

Provider Burnout and Fatigue During the COVID-19 Pandemic: Lessons Learned From a High-Volume Intensive Care Unit.

Provider Burnout and Fatigue During the COVID-19 Pandemic: Lessons Learned From a High-Volume Intensive Care Unit.

Mesoamerican nephropathy - a new challenge for occupational physicians

Mesoamerican nephropathy (MeN) is an endemic form of chronic kidney disease (CKD) that is not related to risk factors for CKD, such as diabetes and hypertension. It primarily affects men, rural and agricultural laborers, who work in an extremely hot and dry environment. The greatest increase in the prevalence of CKD, particularly since the late 1990s, has been reported in Central America and Southern Mexico, where the prevalence is almost 9 times higher than in the USA. The highest mortality associated with CKD is reported in El Salvador where a 10-fold increase was recorded in 1984-2005. In histological examination, MeN patients manifest tubulointerstitial lesions and, in some cases, also lesions in the glomeruli. The cause of MeN remains unclear. Repeated episodes of occupational heat stress, and sweating accompanied by water loss, have a significant impact on the disease development. The disease is a significant social and economic problem, and a challenge in the field of diagnostics, therapy and prevention for physicians of many specialties, especially for occupational physicians. Med Pr. 2020;71(3):353-61.

Acute Psychological Stress is a Trigger for Stroke: A Case-Crossover Study

BackgroundConventional risk factors for stroke that have been identified are mostly chronic diseases that explain much of the variation as to who develops stroke. However, these risk factors do not equip us with the means to predict when an event like stroke will occur. It has been observed that acute events like stroke and coronary heart disease are preceded by episodes of acute stress. The present study was undertaken to determine whether acute psychological stress is a potential triggering factor for the occurrence of stroke. MethodsIn accordance with the case-crossover study design, patients or Legally Authorized Representative (LAR) were asked to report psychological stress during the two-hour hazard period before the event and during the control period, which was the same 2-hour time period the day before the event. Conditional logistic regression was used to compare each person's exposure during the hazard period to their exposure during the control period. ResultsA total of 151 stroke patients were interviewed. Acute psychological stress was associated with transient increased odds of stroke in the subsequent 2 hours that was 3.4 times higher than the odds during periods with no exposure to these triggers (95% confidence interval 1.55-7.50). ConclusionsAcute psychological stress is a potential independent triggering factor for the occurrence of stroke. Further confirmatory studies are required to help corroborate these findings and elucidate the mechanisms underlying this short-term increase in risk.

Environmental stress perception activates structural remodeling of extant Streptococcus mutans biofilms

Transcription regulators from the LexA-like Protein Superfamily control a highly diverse assortment of genetic pathways in response to environmental stress. All characterized members of this family modulate their functionality and stability via a strict coordination with the coprotease function of RecA. Using the LexA-like protein IrvR from Streptococcus mutans, we demonstrate an exception to the RecA paradigm and illustrate how this evolutionary innovation has been coopted to diversify the stress responsiveness of S. mutans biofilms. Using a combination of genetics and biophysical measurements, we demonstrate how non-SOS stresses and SOS stresses each trigger separate regulatory mechanisms that stimulate production of a surface lectin responsible for remodeling the viscoelastic properties of extant biofilms during episodes of environmental stress. These studies demonstrate how changes in the external environment or even anti-biofilm therapeutic agents can activate biofilm-specific adaptive mechanisms responsible for bolstering the integrity of established biofilm communities. Such changes in biofilm community structure are likely to play central roles in the notorious recalcitrance of biofilm infections.