Effects Of Brief Exposure Research Articles

Incidental vocabulary recognition effects of subtitled, captioned and reverse subtitled audiovisual input

This study compares effects of brief exposure to L1 subtitled, L2 captioned, and reverse subtitled audiovisual input on three aspects of vocabulary learning: meaning, form, and pronunciation of target language words. A within-subjects design was used, in which three video clips in the different viewing modes were shown to ten L1 Spanish participants who underwent a pre-test, post-test, and delayed post-test of English terms that each occurred in just one of the videos. The tests measured recognition of meaning, form, and pronunciation through translation into the L1, dictation, and reading the target words aloud with native speaker ratings, respectively. The findings show statistically significant gains in producing the accurate written form of vocabulary in reverse subtitled and L2 captioned video clips, and mixed results for the other variables, including statistically significant gains in pronunciation of vocabulary with L1 subtitles.

Can Brief Listening to Mozart's Music Improve Visual Working Memory? An Update on the Role of Cognitive and Emotional Factors.

The aim of this research was to enhance understanding of the relationship between brief music listening and working memory (WM) functions. The study extends a previous large-scale experiment in which the effects of brief exposure to music on verbal WM were explored. In the present second phase of the experiment, these effects were assessed for the visuospatial subcomponent of WM. For that aim, visuospatial WM was measured using the Corsi blocks task-backwards and Visual Patterns Test in a large sample of 311 young and older adults after being exposed to musical excerpts coming from different music composers (Mozart, Vivaldi, Glass). To account for possible effects of arousal, a silence condition was used. Individual preference for music excerpts and emotional reactions to each condition were also subjectively rated using the Positive and Negative Affect Schedule (PANAS) to account for the role of emotional reactions in shaping subsequent cognitive performance. Results showed that music affected the visuospatial sketchpad of WM. In line with the previously described Mozart effect, only Mozart's music had a significant positive impact on visuospatial WM in the two age groups, regardless of preferences, and on overall age-related WM decline in older adults. The Mozart effect was more prominent for the VPT than the Corsi task and was also expressed for the prevailing positive effect. These observations are in contrast to the selective influence of Vivaldi's music on verbal WM that was detected in our first study. Together, the results demonstrate a differential music influence on the phonological loop and on the visuospatial sketchpad. They thus contribute to the debate of whether music has the potential to affect distinct processes within working memory in an excerpt- or composer-specific manner. Also, they suggest that emotional activation and central executive attention are essentially involved in modulating the influence of music on subsequent cognition. These findings can assist in the selection of music excerpts used in cognitive rehabilitation programs that focus on visuospatial skills.

The effect of brief exposure to virtual nature on mental wellbeing in adolescents

Adolescence is a time of multiple transitions and a vulnerability period for mental health difficulties. There are many barriers to the treatment of mental health conditions which is one reason for developing alternatives to help improve efficacy in treatment and prevention. One approach is to use nature-based interventions (NBIs) to improve mental wellbeing. In this experimental proof-of-principle intervention study, we randomly allocated a sample of adolescents to brief exposure (6 min) to either a virtual woodland nature video or a busy train journey and tested the effect on mental wellbeing. Results showed beneficial effects in the nature condition on several self-reported outcomes including stress, relaxation, affect, mood, attention, nature connection and nature spirituality. The intervention was mainly acceptable and feasible to do suggesting that overall brief virtual nature interventions may have utility in a range of mental health contexts for adolescents including as self-help universal or targeted prevention strategies, adjunct to psychological therapy and as preparation for more intensive NBIs. Additionally, brief virtual nature interventions support accessibility for those who may be limited on time, unable to access real-life nature or who may be more biophobic.

Brief environmental enrichment elicits metaplasticity on the insular cortex in vivo and reduces the strength of conditioned taste aversion

Environmental enrichment (EE) is known to improve memory and cognition and modulate the impact of aversive stimuli in animals, promoting the development of resilience to stressful situations. Likewise, it is known that EE can modulate synaptic plasticity as is the case of long-term potentiation (LTP). These findings have been described initially in ex vivo preparations, suggesting that the effects of EE are the result of an early modification of the synaptic excitability and transmission. In this regard, it is known that metaplasticity refers to the persistent modification, by previous activity, in the ability to induce synaptic plasticity. Our previous studies have shown that prior training in conditioned taste aversion (CTA) prevents the subsequent induction of LTP in the projection from the basolateral nucleus of the amygdala (Bla) to the insular cortex (IC) in vivo. In addition, we have shown that CTA extinction allows the induction but not the maintenance of IC-LTP of the Bla-IC pathway. Recently, we also showed that prior exposure to environmental enrichment for three weeks reduces the strength of CTA, restoring the brain-derived neurotrophic factor (BDNF) levels in the IC. The present study aimed to analyze the effects of brief exposure to an enriched environment on the strength of aversive memory, as well as on the in vivo IC-LTP. To do so, adult rats were exposed for seven days to an EE, either before CTA training or LTP induction in the Bla-IC pathway. Our results demonstrate that a seven-day exposure to an enriched environment attenuates the aversive response to a strong CTA and allows the induction but not the maintenance of LTP in the insular cortex. These findings provide evidence that metaplastic regulation in a neocortical region takes part in the mechanisms through which brief exposure to enriched environments attenuates an aversive response.

Effect of brief exposures of anesthesia on thermotolerance and metabolic rate of the spotted-wing fly, Drosophila suzukii: Differences between sexes?

The spotted-wing fly, Drosophila suzukii, is a world-wide pest insect for which there is increasing interest in its physiological traits including metabolism and thermotolerance. Most studies focus only on survival to different time exposures to extreme temperatures, mainly in female flies. In addition, it has not been tested yet how anesthesia affects these measurements. We analyzed the effects of anesthesia by brief exposures to cold, anoxia by CO2 or N2 on three standard thermotolerance assays, as well as the aerobic metabolic rate in both sexes. For heat tolerance we measured CTmax by thermolimit respirometry, and CTmin and chill-coma recovery time for cold tolerance. Aerobic metabolism was calculated by CO2 production of individual flies in real time by open flow respirometry. Results showed that females have a significantly higher V̇CO2 for inactive (at 25 °C) and maximum metabolic rate than males. This difference is mainly explained by body mass and disappears after mass correction. Males had a more sensitive MR to temperature than females showed by a significantly higher Q10 (2.19 vs. 1.98, for males and females, respectively). We observed a significantly lower CTmin (X2 = 4.27, P = 0.03) in females (3.68 ± 0.38 °C) than males (4.56 ± 0.39 °C), although we did not find significant effects of anesthesia. In contrast, anesthesia significantly modifies CTmax for both sexes (F3,62 = 7.86, P < 0.001) with a decrease of the CTmax in cold-anesthetized flies. Finally, we found a significantly higher CTmax in females (37.87 ± 0.07 °C) than males (37.36 ± 0.09 °C). We conclude that cold anesthesia seems to have detrimental effects on heat tolerance, and females have broader thermotolerance range than males, which could help them to establish in invaded temperate regions with more variable environmental temperatures.

Effects of brief exposure to campus environment on students' physiological and psychological health.

Experiences in natural environments can enhance human wellbeing and promote the recovery of physiological and psychological health. During the COVID-19 pandemic, university students' activity off-campus was limited, thus, the campus environment was particularly important for the recovery of students' physiological and psychological health. Although the benefits of sustained natural exposure are obvious for people's physiological and psychological health, the effects of brief exposure on physiological and psychological are unclear. In the present study, four types of campus environments, including square space, dense forest space, sparse forest space, and waterfront space, were selected to explore the transient recovery effects of different types of campus environments. Sixty university students were recruited, measuring their systolic blood pressure, diastolic blood pressure, and heart rate as physical parameters to assess stress recovery. Respondents also reported scores about their personal feelings in questionnaires to evaluate their psychological states. Both physiological and psychological indicators responded to the brief natural exposure (5 min), and physiological and psychological health was restored. However, only the recovery amounts of psychological indicators were significantly different in waterfront space, dense forest space, and sparse forest space. These results indicate that being compare with other spaces, the brief exposure in the waterfront space was the most beneficial to students' psychological health recovery. This recovery was attributed to the great role played by the sense of escape, but after the brief exposure, the attraction and compatibility of the environment would hinder the psychological health recovery. In conclusion, according to tests on both physiological and psychological aspects, the waterfront environment on campus is the best choice for students' transient health recovery.

Effects of Morning or Evening Narrow-band Blue Light on the Compensation to Lens-induced Hyperopic Defocus in Chicks.

Exposure to blue light before bedtime is purported to be deleterious to various aspects of human health. In chicks, blue evening light stimulated ocular growth, suggesting a role in myopia development. To further investigate this hypothesis, we asked if brief blue light altered the compensatory responses to hyperopic defocus. Previous work showed that several hours' evening exposure to blue light stimulated ocular growth in chicks, but morning exposure was only effective at a lower illuminance. By contrast, rearing in blue light has inhibited ocular growth in untreated eyes and eyes exposed to form deprivation or defocus. We studied the effects of brief exposures to blue light on the compensation to hyperopic defocus. Chicks wore monocular negative lenses (-10 D) starting at age 10 days. They were subsequently exposed to blue light (460 nm) for 4 hours in the morning or evening for 8 to 9 days ("dim," 200 lux[morning, n = 9; evening, n = 11]; "bright," 600 lux[morning, n = 8; evening, n = 20]); controls wore lenses in white light (n = 14). Ultrasonography was done on days 1, 5, 8, and 9 for "evening" groups and days 1, 6, and 8 for "morning." All data are reported as interocular differences (experimental minus fellow eyes). Refractions were measured on the last day. For evening exposure, dim blue light enhanced the axial compensation at all times (change in axial length: day 6: 465 vs. 329 μm/9 days, analysis of variance P < .001, P = .03; day 9: 603 vs. 416 μm/9 days, analysis of variance P < .001; P < .05). Bright blue light had a transient inhibitory effect (day 5: 160 vs. 329 μm; P < .005). Refractive errors were consistent with axial growth, with dim causing more myopia than bright (-9.4 vs. -4.7 D; P < .05). Morning blue light had no significant effect. We speculate that these findings reflect a complex interaction between illuminance, defocus, and time of day.

Risk Factors for Road-Traffic Injuries Associated with E-Bike: Case-Control and Case-Crossover Study.

The Electric Bike (EB) has become an ideal mode of transportation because of its simple operation, convenience, and because it is time saving, economical and environmentally friendly. However, electric bicycle road-traffic injuries (ERTIs) have become a road-traffic safety problem that needs to be solved urgently, bringing a huge burden to public health. In order to provide basic data and a theoretical basis for the prevention and control of ERTIs in Shantou, mixed research combining a case-control study and a case-crossover study was carried out to investigate the cycling behavior characteristics and injury status of EB riders in Shantou city, and to explore the influencing factors of ERTI. The case-control study selected the orthopedic inpatient departments of three general hospitals in Shantou. The case-crossover study was designed to assess the effect of brief exposure on the occurrence of ERTIs, in which each orthopedic inpatient serves as his or her own control. Univariable and multivariable logistic regressions were used to examine the associated factors of ERTIs. In the case-control study, multivariable analysis showed that chasing or playing when cycling, finding the vehicle breakdown but continuing cycling, not wearing the helmet, and retrograde cycling were risk factors of ERTIs. Compared with urban road sections, suburb and township road sections were more likely to result in ERTIs. Astigmatism was the protective factor of ERTI. The case-crossover study showed that answering the phone or making a call and not wearing a helmet while cycling increased the risk of ERTIs. Cycling in the motor-vehicle lane and cycling on the sidewalk were both protective factors. Therefore, the traffic management department should effectively implement the policy about wearing a helmet while cycling, increasing the helmet-wearing rate of EB cyclists, and resolutely eliminate illegal behaviors such as violating traffic lights and using mobile phones while cycling. Mixed lanes were high-incidence road sections of ERTIs. It was suggested that adding people-non-motor-vehicles/motor vehicles diversion and isolation facilities in the future to ensure smooth roads and safety would maximize the social economic and public health benefits of EB.

Evidence for the effect of brief exposure to food, but not learning interference, on maze solving in desert ants.

Theories of forgetting highlight 2 active mechanisms through which animals forget prior knowledge by reciprocal disruption of memories. According to "proactive interference," information learned previously interferes with the acquisition of new information, whereas "retroactive interference" suggests that newly gathered information interferes with already existing information. Our goal was to examine the possible effect of both mechanisms in the desert ant Cataglyphis niger, which does not use pheromone recruitment, when learning spatial information while searching for food in a maze. Our experiment indicated that neither proactive nor retroactive interference took place in this system although this awaits confirmation with individual-level learning assays. Rather, the ants' persistence or readiness to search for food grew with successive runs in the maze. Elevated persistence led to more ant workers arriving at the food when retested a day later, even if the maze was shifted between runs. We support this finding in a second experiment, where ant workers reached the food reward at the maze end in higher numbers after encountering food in the maze entry compared to a treatment, in which food was present only at the maze end. This result suggests that spatial learning and search persistence are 2 parallel behavioral mechanisms, both assisting foraging ants. We suggest that their relative contribution should depend on habitat complexity.

Effects of brief exposure to misinformation about e-cigarette harms on Twitter on knowledge and perceptions of e-cigarettes.

BackgroundThis study examined whether exposure to misinformation found on Twitter about e-cigarette harms leads to inaccurate knowledge and misperceptions of harms of e-cigarette use among cigarette smokers.MethodsWe conducted an online randomized controlled experiment in November 2019 among an online sample of 2400 adult US and UK cigarette smokers who did not currently use e-cigarettes. Participants viewed four tweets in one of four conditions: 1) e-cigarettes are as or more harmful than smoking, 2) e-cigarettes are completely harmless, 3) e-cigarette harms are uncertain and 4) control (physical activity). Outcomes were knowledge about e-cigarettes and harm perceptions of e-cigarette use for five diseases. We conducted multiple logistic and linear regressions to analyze the effect of experimental conditions on outcomes, controlling for baseline knowledge and perceived harms.FindingsParticipants in the ‘as or more harmful’ condition (vs. control group) had higher odds of accurate knowledge about e-cigarettes containing toxic chemicals (p < 0.001), not containing only water vapor (p < 0.001) and containing formaldehyde (p < 0.001). However, these participants had lower odds of accurate knowledge that e-cigarettes did not contain tar (p < 0.001) and contained fewer toxins than cigarettes (p < 0.001). Exposure to ‘as or more harmful’ tweets also increased harm perceptions for five diseases (all p < 0.001), with the greatest effect observed for lung cancer (β = 0.313, p < 0.001). This effect was greater among UK participants for all diseases.InterpretationBrief exposure to misinformation on Twitter reduced accurate knowledge of the presence of tar and the level of toxins compared with smoking and increased harm perceptions of e-cigarette use.

The effect of priming on food choice: A field and laboratory study

Priming involves the activation of a mental concept in memory which increases the likelihood that it will be assimilated into subsequent information processing. The present study investigates whether exposure to prime stimuli can increase the selection of unhealthy foods, which is an important topic as priming has been found to influence judgements, decisions, and behaviour outside of awareness. Study one was a between-subjects field study which examined the effect of brief exposure to food-related logos on subsequent snack choice. Study two took this further by examining food choice following exposure to unhealthy food-related logos in a laboratory setting. No main effect of priming was found by either the field study or the laboratory study; the participants in both studies made similar food choices regardless of condition. However, the results of study two showed a significant main effect of trait mindfulness on food choice, whereby participants higher in trait mindfulness selected fewer unhealthy foods. In conclusion, further research is required to determine whether exposure to unhealthy food-related logos can increase the selection of unhealthy foods. Although the potential for mindfulness to reduce the selection of unhealthy foods looks promising, this also requires further investigation through experimental research.

Effects of brief exposure to misinformation about e-cigarette harms on twitter: a randomised controlled experiment

ObjectivesTo assess the effect of exposure to misinformation about e-cigarette harms found on Twitter on adult current smokers’ intention to quit smoking cigarettes, intention to purchase e-cigarettes and perceived relative...

Effect of Phytochrome Deficit on Activity of Ascorbate Peroxidase and Phenylalanine Ammonia-Lyase and Expression of Genes APX1, tAPX, sAPX, and PAL in the Leaves of Arabidopsis thaliana Plants Exposed to UV-A and Red Light

Effect of UV-A radiation (10 W/m2, 2 h) and modifying effect of brief exposure to red light (RL) (1.8 W/m2, 20 min) on photochemical activity of photosystem II (PSII) (Fv/Fm), as well as on activity of ascorbate peroxidase (AsP) and phenylalanine ammonia-lyase (PAL), were investigated in the leaves of 26–28-day-old Аrabidopsis thaliana (L.) Heynh. plants of wild type (WT) and mutants: hy3 deficient in phytochrome B (phyB) and hy2 defective in phytochromobilin synthesis. UV-A reduced photochemical activity of PSII and activities of AsP and PAL. Exposure to RL increased PAL activity in only WT plants and in mutant hy3. Elevation of expression of genes APX1, sAPX, tAPX, and PAL encoding enzymes AsP and PAL was detected upon the exposure to RL and UV-A. For instance, expression of gene APX1 in WT plants and in mutant hy3 rose upon exposure to RL and UV-A; in mutant hy2, it increased only upon UV-A treatment. Expression of gene tAPX in WT plants rose only under the effect of RL, whereas expression of gene sAPX did not rise in any type of treatment. In mutant hy2, expression of the above-named genes decreased upon the effect of RL. Upon joint action of RL and UV-A (RL followed by UV), the negative effect of UV-A on the activity of the total pool of AsP was nullified by RL in only WT plants and in mutant hy3. Partial removal of the negative effect of UV-A on activity of PSII as a result of pretreatment of plants with RL is probably related to a rise in the activity of antioxidant enzymes. This is evident in WT plants whose PSII is more sensitive to RL radiation than in mutants deficient in phytochromes. We believe that PSII resistance to UV-A radiation depends on the potential of the plant antioxidant system, which rises when the share of the active form of phytochrome in its total pool increases as a result of plants’ pretreatment with RL and is partially realized by way of induction of transcriptional activity of antioxidant genes.

Effects of brief exposure to loud music on otoacoustic emissions and auditory brainstem responses

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Research on noise induced hearing loss pathophysiology has recently focused on synapses rather than outer hair cells, following relevant evidence from animal studies. Findings from human studies, mainly targeting on effect of chronic exposure are controversial. Aim of this study is to investigate the immediate effect of noise exposure to synaptic function with use of ABR and DPOAEs.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Ten participants with normal hearing levels underwent DP-gram between 1 and 6 KHz and ABR at 90dB and click rates 33/sec and 44/sec before and after exposure to standardized music. Four of them were professional musicians and six were controls. Material for reliable and constant exposure to music was created, consisting of 56 wav files with music with a total duration of 2.5 hours. Files were presented in stable dB SPL levels and absolute control of dB SPL levels to ear phones was ensured. Subjects were asked to listen to music of their preference in maximum for 30 minutes. Patients exceeding 83 dB SPL maximum comfortable levels were eligible for the study. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Statistically significant differences were observed before and after exposure to music for all SNRs from 1.5 to 6 KHz. Changes were similar between musicians and non-musicians. No differences were observed in ABR latencies and amplitudes in any of the waveforms before and after noise exposure.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; A reliable technique has been developed for standardized exposure to loud sounds in humans, which can be used in future studies. Exposure to music induced decrease in DPOAE SNRs.&lt;/p&gt;&lt;p class="abstract"&gt; &lt;/p&gt;

Stress and nicotine during adolescence disrupts adult hippocampal‐dependent learning and alters stress reactivity

Adolescence represents increased susceptibility to stress that increases risk for nicotine dependence. The present study examined the interactive effects of brief exposure to stress (shipping/transportation or experimentally induced) and chronic nicotine during adolescence on cognitive function and stress reactivity in adulthood. Adolescent (P31), but not young adult (P47), C57BL/6J mice had higher levels of corticosterone after shipping vs mice bred onsite. Shipped preadolescent (P23) and adolescent (P38) mice, but not those bred onsite, exposed to nicotine showed deficits in contextual fear learning when tested in adulthood. Adult learning deficits were replicated in adolescent mice bred onsite, exposed to experimentally induced stress, and administered chronic nicotine. Stress and nicotine during adolescence resulted in higher expression of hippocampal glucocorticoid receptors and corticotropin-releasing factor receptors and blunted restraint induced CORT release in adulthood. Importantly, studies examining adolescent behavior in mice should consider stress influences outcomes.

Defining the RNA interactome by total RNA‐associated protein purification

The RNA binding proteome (RBPome) was previously investigated using UV crosslinking and purification of poly(A)‐associated proteins. However, most cellular transcripts are not polyadenylated. We therefore developed total RNA‐associated protein purification (TRAPP) based on 254 nm UV crosslinking and purification of all RNA–protein complexes using silica beads. In a variant approach (PAR‐TRAPP), RNAs were labelled with 4‐thiouracil prior to 350 nm crosslinking. PAR‐TRAPP in yeast identified hundreds of RNA binding proteins, strongly enriched for canonical RBPs. In comparison, TRAPP identified many more proteins not expected to bind RNA, and this correlated strongly with protein abundance. Comparing TRAPP in yeast and E. coli showed apparent conservation of RNA binding by metabolic enzymes. Illustrating the value of total RBP purification, we discovered that the glycolytic enzyme enolase interacts with tRNAs. Exploiting PAR‐TRAPP to determine the effects of brief exposure to weak acid stress revealed specific changes in late 60S ribosome biogenesis. Furthermore, we identified the precise sites of crosslinking for hundreds of RNA–peptide conjugates, using iTRAPP, providing insights into potential regulation. We conclude that TRAPP is a widely applicable tool for RBPome characterization.

Do different sitting postures affect spinal biomechanics of asymptomatic individuals?

BackgroundStatic sitting is thought to be related to low back pain. Of various common seated postures, slouched sitting has been suggested to cause viscoelastic creep. This, in turn, may compromise trunk muscle activity and proprioception, and heightening the risk of low back pain. To date, no research has evaluated immediate and short-term effects of brief exposures to different sitting postures on spinal biomechanics and trunk proprioception. Research questionThis study aimed to compare the impacts of 20 min of static slouched, upright and supported sitting with a backrest on trunk range of motion, muscle activity, and proprioception immediately after and 30 min after the sitting tasks. MethodsThirty-seven adults were randomly assigned to the three sitting posture groups. Surface electromyography of six trunk muscles during maximum voluntary contractions were measured at baseline for normalization. Pain intensity, lumbar range of motion, and proprioceptive postural control strategy were assessed at baseline, 20 min (immediately post-test) and at 50 min (recovery). Trunk muscle activity during sitting was continuously monitored by surface electromyography. ResultsWhile the slouched sitting group demonstrated the lowest bilateral obliquus internus/transversus abdominis activity as compared to other sitting postures (F = 4.87, p < 0.05), no significant temporal changes in pain intensity, lumbar range of motion nor proprioceptive strategy were noted in any of the groups. SignificanceSitting for 20 min of duration appears to have no adverse effects on symptoms or spinal biomechanics regardless of the posture adopted. Future research should determine if there is a point at which does slouched sitting cause significant changes in pain/spinal biomechanics in people both with and without low back pain.

Abstract 54: The Effect of Nicotine and Menthol in Secondhand Smoke on Endothelial Function

Introduction: We have previously shown that even one minute of exposure to secondhand smoke (SHS) of tobacco and marijuana can impair arterial flow-mediated dilation (FMD) in rats. The identity of specific constituents of SHS that cause vascular toxicity remains unclear. Nicotine is a vasoconstrictor that potentially can affect vascular function. Menthol is a cigarette additive popular with African Americans, women, youth, and other ethnicities. Menthol interacts with smoke constituents and irritants such as acrolein through receptor ion channels and also affects the metabolism rate of nicotine. Hypothesis: We tested three hypotheses pertaining to acute effects of brief exposures to SHS: (1) nicotine increases the extent of endothelial functional impairment; (2) menthol decreases the extent of endothelial functional impairment; and (3) there is an interaction between the effects of nicotine and menthol. Methods: We exposed 8 groups of rats (n=8-10/group) for 10 minutes to two different levels of SHS from the following four different types of research reference tobacco: conventional nicotine (~15 mg/g tobacco), reduced nicotine (~0.4 mg/g tobacco), and both conventional and reduced nicotine with added menthol (~1.15 mg/g tobacco) in a 2x2 factorial (ANOVA) design. We also examined a clean air negative control group (n=9). FMD was measured before and after exposures in each rat. To calculate FMD, the femoral artery diameter was measured with micro-ultrasound before and after a 5-min transient ischemia induced by an external vascular occluder. FMD was quantified as the % vasodilation. Results: FMD was not affected in the clean air controls (p=0.13). Higher nicotine levels were associated with increased % reduction of FMD impairment (19.22±9.53% vs. 41.07±4.54% (SD); p=0.047). Adding menthol was associated with decreased % reduction of FMD impairment (40.52±4.85% vs. 18.50±9.81%; p=0.048). These two effects were independent (p for nicotine x menthol interaction = 0.6). Conclusion: Reduction of nicotine level and addition of menthol each lessen the acute impairment of FMD in rats exposed briefly to tobacco SHS.

DARPP-32 interaction with adducin may mediate rapid environmental effects on striatal neurons.

Environmental enrichment has multiple effects on behaviour, including modification of responses to psychostimulant drugs mediated by striatal neurons. However, the underlying molecular and cellular mechanisms are not known. Here we show that DARPP-32, a hub signalling protein in striatal neurons, interacts with adducins, which are cytoskeletal proteins that cap actin filaments' fast-growing ends and regulate synaptic stability. DARPP-32 binds to adducin MARCKS domain and this interaction is modulated by DARPP-32 Ser97 phosphorylation. Phospho-Thr75-DARPP-32 facilitates β-adducin Ser713 phosphorylation through inhibition of a cAMP-dependent protein kinase/phosphatase-2A cascade. Caffeine or 24-h exposure to a novel enriched environment increases adducin phosphorylation in WT, but not T75A mutant mice. This cascade is implicated in the effects of brief exposure to novel enriched environment on dendritic spines in nucleus accumbens and cocaine locomotor response. Our results suggest a molecular pathway by which environmental changes may rapidly alter responsiveness of striatal neurons involved in the reward system.

The Effect of Brief Exposure to Sub-Therapeutic Concentrations of Chlorhexidine Digluconate on the Susceptibility of Staphylococci to Platelet Microbicidal Protein.

Antiseptic agents are widely used in hospitals and are essential when prevention and control of nosocomial infections is required. It is necessary to consider several aspects that affect the biocide activity because they have direct impact on the nosocomial infection rate. Organisms belonging to the Staphylococcus genus are involved in such infections and chlorhexidine digluconate (CHXD) is one of the most used antiseptic agents for human and animal health. In the context of such infections, anti-bacterial peptides have been isolated from platelets and have been termed platelet microbicidal proteins (PMP). Platelet microbicidal proteins have been shown to enhance the bacterial inhibitory activities of sub-therapeutic concentrations of antibiotics. The main objective of this study was to investigate the effect of brief exposure to different sub-therapeutic concentrations of CHXD on the susceptibility of staphylococci to PMP. The influence of brief exposure to three different sub-therapeutic concentrations of CHXD (0.005%, 0.0025%, and 0.00125%) on the subsequent staphylocidal effect of PMP was evaluated. Among all clinical staphylococcal strains studied, all isolates were considered to be resistant to the bactericidal action of PMP. Exposure of staphylococci to CHXD prior to PMP resulted in significantly increased staphylococcal killing compared with the killing achieved with PMP alone. This enhanced effect was most marked for concentrations of CHXD of 0.005%. The combined data indicate that PMP exerts cooperative bactericidal effect with CHXD. The anti-staphylococcal PMP and CHXD synergistic activity in vitro demonstrated in the present study make these molecules potentially useful for preventing endovascular catheter-associated infections. Future research based on animal and human models is needed to elucidate the in vivo efficacies and toxicities and utility in clinical practice.