Use of saliva for assessment of stress and its effect on the immune system prior to gross anatomy practical examinations

Prolonged chronic academic stress and its relationship with cytokine dysregulation in health science students

Academic stress is a problem that affects students due to a number of factors that are considered stressors. These include academic overload and completion of assignments and exams, exacerbated by such external conditions as family, social and economic problems. Together, these can affect emotional and physical health, which may lead in the long term to developing a number of pathologies, given the alteration of immunological homoeostasis with which they are related.

OBJECTIVE

To evaluate the effect of academic stress on the production of cytokines IL-6, TNF-α, IL-1β and IL-10 in Morphology students in the Faculty of Health Sciences of the Universidad del Cauca during an academic period.

METHODOLOGY

A descriptive longitudinal study was carried out with a population of 78 students studying Morphology, among the subjects with the highest academic load in the Physiotherapy, Medicine, Nursing and Phonoaudiology programs in the Faculty. Academic stress was assessed in the students by applying the Academic Stress Questionnaire (ASQ), and through quantification of the IL-6, TNF-α, IL-1β and IL-10 cytokines using the ELISA (Enzyme-linked immunosorbent assay) technique in three "moments" of the academic semester: Moment 1: beginning of the academic semester; Moment 2: week of evaluations of 70% of the semester; Moment 3: week of final exams.

RESULTS

The students perceived stress as "normal" at Moment 1, while at Moments 2 and 3 it was perceived as "quite a lot", with percentages of 48.7% and 50%, respectively. The predominant stressors were: "methodological deficiencies", "academic overload", and "exams", for the three moments of the study. "Physical exhaustion" was the most prevalent stress response at all three moments, followed by "irascible behaviour" (Moment 2 and 3), and "sleep disturbances" (Moment 3). To cope with the stress, the students resorted mainly to "planning and management of personal resources" in the three moments of the study. A progressive increase in the pro-inflammatory cytokines IL-6 and TNF-α and a decrease in IL-10 were observed at all three moments. A correlation was found between some questions belonging to the "methodological deficiencies", "beliefs about performance", "sleep disturbances", "physical exhaustion" and "irascible behaviour" dimensions with IL-6, IL-1β, TNF-α and IL. -10.

CONCLUSION

The morphology students suffer increased stress indicators (perceived stress and pro-inflammatory cytokines) throughout the academic period. The "methodological deficiencies", "academic overload" and "exams" stressors, together with "physical exhaustion", "sleep disturbances" and "irascible behaviour", possibly influence the production of the IL-6, TNF-α and IL-10 cytokines.

Decreased sympathetic cardiovascular influences and hormone-physiological changes in response to Covid-19-related adaptations under different learning environments

To examine the implications of the transition from face-to-face to online learning from a psychobiological perspective, this study investigated potential differences in physiological stress parameters of students engaged in online or face-to-face learning and determined whether these can be identified as possible mediators between learning experience and achievement emotions. In a randomized experimental field study, medical students (n = 82) attended either regular face-to-face classes of the microscopic anatomy course or the same practical course online using Zoom videoconferencing platform. The present study investigated Heart Rate Variability (HRV) and salivary cortisol concentration as stress correlates, within the contexts of online and face-to-face learning and compared these parameters with a control group that was measured at rest. Additionally, participants completed a standardized questionnaire about their experienced emotions in relation to task achievement and subjective stress levels. A significant reduction in HRV was found in face-to-face learning, suggesting stronger stress responses in the face-to-face learning environment (η²  = 0.421, P < 0.001). Furthermore, participants engaged in face-to-face learning showed significantly higher cortisol concentrations (η²  = 0.115, P = 0.032). Additionally, increased sympathetic activation correlated with the discrete positive emotion of enjoyment exclusively within the face-to-face condition (r = 0.365, P = 0.043). These results indicate that the transfer of a face-to-face practical course in microscopic anatomy to an online learning environment is associated with decreased sympathetic and enhanced vagal cardiovascular influences, together with lower cortisol concentrations in healthy medical students.

A short Mindfulness retreat can improve biological markers of stress and inflammation

OBJECTIVE

Mindfulness practice, a form of meditation, has shown benefit for psychological and physical health. In this study, we investigated the effect of an intensive period of Mindfulness practice on some biological mediators of stress and inflammation during a 3-day residential retreat.

METHODS

A total of 95 healthy individuals (aged 18-67) were recruited and randomized to a Mindfulness retreat arm or an active control arm. Before (t0) and after (t1) the intervention, all the participants were assessed for salivary cortisol levels and for a panel of pro- and anti-inflammatory cytokines measured in saliva. Psychometric measures on stress, anxiety and awareness were carried out using PSS, STAI-Y and MAAS questionnaires, respectively.

RESULTS

As to the within-group differences, we observed a statistically significant decrease in perceived stress (β = -8.85, p < 0.0001), and anxiety scores (β = -12.39, p < 0.0001), while awareness increased (β = 15.26, p < 0.0001) between t0 to t1 in retreat participants. In the mindfulness intervention group, we also observed a statistically significant reduction in the levels of pro-inflammatory cytokines IL-6 (β = -0.94 p = 0.001) and IL-8 (β = -176.40, p < 0.0001), and an increase in anti-inflammatory IL-10 (β = 0.89 p < 0.0001) levels at the end of the retreat. At t1 we observed a highly significant correlation between cortisol levels and both anxiety (r = 0.56, p < 0.0001) and perceived stress (r = 0.92, p < 0.0001) scores.

CONCLUSIONS

Mindfulness retreat participants showed a significant reduction in perceived stress and anxiety levels, as well as an improved balance of some key mediators of inflammatory states. Our data provide evidence that a mindfulness retreat may be effective in improving physical and mental health. Future studies with larger numbers of subjects and follow-up periods may examine mindfulness practice as a non-pharmacological alternative to promote stress reduction and overall health and wellbeing.

A Review of First-Year Student Stress and Social Support

The present paper reviews empirical literature on stress and social support relative to first-year post-secondary students, published between 1996 and 2020. Empirical studies included in the literature search focused on stress, coping, and social support specifically among first-year undergraduate students while studying in countries adopting North American higher education models comparable to the United States and Canada. This review examines contextual and psychological antecedents and correlates of stress, as well as associated demographic and achievement variables. Furthermore, this review extends to studies on social support categorized by source (peers, family, faculty, institution, and multiple sources of support). A synthesis and critique of the literature explores the themes in the empirical research presented, as well as considerations for future research.

Alterations in Saliva and Plasma Cytokine Concentrations During Long-Duration Spaceflight

Long-duration spaceflight is known to cause immune dysregulation in astronauts. Biomarkers of immune system function are needed to determine both the need for and effectiveness of potential immune countermeasures for astronauts. Whereas plasma cytokine concentrations are a well-established biomarker of immune status, salivary cytokine concentrations are emerging as a sensitive indicator of stress and inflammation. For this study, to aid in characterizing immune dysregulation during spaceflight, plasma and saliva cytokines were monitored in astronauts before, during and after long-duration spaceflight onboard the International Space Station. Blood was collected from 13 astronauts at 3 timepoints before, 5 timepoints during and 3 timepoints after spaceflight. Saliva was collected from 6 astronauts at 2 timepoints before spaceflight, 2 timepoints during and 3 timepoints following spaceflight. Samples were analyzed using multiplex array technology. Significant increases in the plasma concentration of IL-3, IL-15, IL-12p40, IFN-α2, and IL-7 were observed during spaceflight compared to before flight baseline. Significant decreases in saliva GM-CSF, IL-12p70, IL-10 and IL-13 were also observed during spaceflight as compared to compared to before flight baseline concentrations. Additionally, plasma TGFβ1 and TGFβ2 concentrations tended to be consistently higher during spaceflight, although these did not reach statistical significance. Overall, the findings confirm an in-vivo hormonal dysregulation of immunity, appearing pro-inflammatory and Th1 in nature, persists during long-duration orbital spaceflight. These biomarkers may therefore have utility for monitoring the effectiveness of biomedical countermeasures for astronauts, with potential application in terrestrial research and medicine.

Effects of Eight-Week Combined Resistance and Endurance Training on Salivary Interleukin-12, Tumor Necrosis Factor, Cortisol, and Testosterone Levels in Patients with Breast Cancer

Background: In recent years, several studies have shown the association between exercise and decreased risk of mortality in patients with breast cancer. However, the effects of combined resistance and endurance training on salivary Interleukin-12 (IL-12), tumor necrosis factor (TNF-α), Cortisol, and Testosterone levels in patients with breast cancer have not been investigated. Objectives: This study aimed at determining the effect of 8 weeks of combined resistance and endurance training on salivary IL-12, TNF-α, Cortisol, and Testosterone levels in women with breast cancer. Methods: Forty-two postmenopausal women with breast cancer were randomly selected and divided into training (intervention) and control groups. The training group performed resistance training with 2 to 3 sets, 10 to 18 repetitions, 50 to 70% 1 repetition maximum (1RM), and aerobic exercise with 50 to 70% maximum heart rate (maxHR) (12-14 degrees borg scale) for 20 to 40 minutes for 8 weeks. The salivary IL-12, TNF-α, cortisol, and testosterone levels were measured, using the enzyme-linked immunosorbent assay (ELISA) method. Two-way analysis of variance repeated measure was also used to analyze variance with the confidence interval of 95%. Results: In the training group, there was a significant decrease in salivary TNF-α levels, cortisol, TNF-α/IL-12 ratio, and variables of weight, fat percentage, body mass index (BMI), and waist circumference (P < 0.05). Also, the results showed a significant increase in salivary testosterone and testosterone/cortisol ratio in the intervention group (P < 0.05). However, no significant changes were observed in the interaction between-group and time in IL-12 and waist–hip ratio (WHR) values (P > 0.05). Conclusions: The results indicate that resistance and endurance training could be used as a useful method to improve salivary pro-inflammatory factors and hormonal levels in patients with breast cancer. Medical oncologists can underline a resistance and endurance training program for patients with breast cancer under their care.

Association between declines in objective masticatory performance and salivary stress markers: The Suita study

Dentists often encounter patients suffering from psychological and social stress due to declines in masticatory performance, making this a critical issue to manage. We aimed to clarify the relationships between salivary stress markers as objective indices of chronic stress and objective masticatory performance in a general urban Japanese population. Data from 880 participants (mean age, 65.8 years) in the Suita study were used. Salivary interleukin (IL)-6 and cortisol concentrations were measured by enzyme-linked immunosorbent assay. Objective masticatory performance was determined by measuring the increase in surface area test gummy jelly after 30 times chewing. Participants were divided into two groups based on masticatory performance: a decreased group (lowest quartile) and a non-decreased group (second to fourth quartiles). Odds ratios (ORs) of higher salivary levels of stress markers (highest quartile) according to masticatory performance were estimated using logistic regression analysis adjusting for age, sex, periodontal status, salivary flow rate and smoking habit. Salivary IL-6 level was significantly higher in the decreased group than in the non-decreased group. Logistic regression analysis showed the adjusted OR for higher salivary IL-6 was significantly higher in the decreased group than in the non-decreased group (OR = 1.92; 95% confidence interval = 1.33-2.76; P < .001). No significant associations were found between salivary cortisol and decreased masticatory performance in any analyses. Declines in objective masticatory performance may correlate with higher salivary IL-6 level as an objective index of chronic stress.

Possible utilization of salivary IFN-γ/IL-4 ratio as a marker of chronic stress in healthy individuals

Introduction

Several studies show that psychological stress reduces Th1/Th2 ratio in blood samples. However, evidence is scarce regarding the cytokine alterations during stress in saliva. We investigated the influence of chronic stress on Th1/Th2 ratio and cytokine profiles in the saliva of healthy individuals. Further, we examined the associations of the salivary cytokine levels with sleep and attention problems, which are closely related with psychological stress.

Methods

Salivary levels of 27 cytokines were measured by multiplex bead array assays in 31 healthy young individuals (health science students and hospital staff consisting of 11 men and 20 women, mean age [standard deviation] =21.5 [0.8] years). The Kessler Psychological Distress scale (K10) and Athens Insomnia Scale (AIS) were administered to assess subjective chronic psychological stress and sleep problems. Further, participants were asked to wear Actigraph GT3X accelerometers for 3 days to assess the total sleep time. Attention problems were assessed by administering the Integrated Visual and Auditory Continuous Performance Test (IVA‐CPT).

Results

Thirteen cytokines with >80% detectable results were included in the main analyses. The IFN‐γ/IL‐4 ratio, which is a commonly used index for Th1/Th2 ratio, showed significant negative correlations with the K10 and AIS scores. None of the cytokines were significantly associated with sex, body mass index, sleep index measured by Actigraph, or IVA‐CPT scores.

Conclusion

Chronic stress may be associated with alterations of the Th1/Th2 balance in salivary cytokine production. IFN‐γ/IL‐4 ratio in saliva may serve as a potential biomarker of chronic stress in healthy individuals.

The present study investigated the influence of chronic stress on Th1/Th2 ratio and cytokine profiles in the saliva of healthy individuals. The IFN‐γ/IL‐4 ratio showed a significant negative correlation with chronic stress, assessed by the Kessler Psychological Distress scale. IFN‐γ/IL‐4 ratio in saliva may serve as a potential biomarker of chronic stress in healthy individuals.

Salivary inflammatory cytokines echo the low inflammatory burden in liver-transplanted children

OBJECTIVES

The aims of this study were to compare the salivary cytokine profile, as a potential replacement for blood tests, in liver-transplanted children to that of a control group of healthy children, and to correlate the values of commonly tested laboratory blood tests to those of published blood values.

METHODS

Liver-transplanted children, and a control group of healthy children of the same sex and age distribution, were recruited for the study. Saliva was collected at the same appointment for routine blood tests for the liver-transplanted children. Saliva was also collected from a control group of healthy children with similar age and sex distributions. Normal healthy blood values were extracted from the literature, for comparison. Cytokine levels in the saliva were quantified with ELISA. The analysis compared serum and saliva values between liver-transplanted and healthy children. In the serum, the values of albumin, GIT, GPT, GGT, CRP, WBC, neutrophils, and lymphocytes were examined, while the levels of IL-6, CXCL1, IL-1b, and IL-10 were measured in the saliva.

RESULTS

Thirty liver-transplanted children and 30 healthy children were included in the study. Compared with published data for healthy children, the liver-transplanted group showed similar hepatic serum levels, yet reduced levels of serum inflammatory markers. Compared with the control group, in the transplanted group, the mean value of IL-6 was lower and the mean value of CXCL1 was similar. Interestingly, the anti-inflammatory IL-10 cytokine was lower in the transplanted group, while the pro-inflammatory IL-1β cytokine was higher.

CONCLUSION

The salivary inflammatory markers examined showed a similar pattern to the serum inflammatory values, though different markers were examined in the serum and saliva.

CLINICAL RELEVANCE

The current study stresses the potential of oral fluids as an accessible biofluid, for use as a diagnostic substrate for systemic and oral diseases.

TRIAL REGISTRATION

0136-16-RMC, Registered on 01 March 2018.

Executive Control, Cytokine Reactivity to Social Stress, and Depressive Symptoms: Testing the Social Signal Transduction Theory of Depression

Social Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression for some individuals. However, the specific cognitive processes underlying social stress-induced increases in inflammatory activity remain unclear. We addressed this issue by examining two separate relations: (1) between executive control measured following a laboratory-based social stress induction and individuals' pro-inflammatory cytokine responses to the same stress induction and (2) between pro-inflammatory cytokine responses and participants' depressive symptom levels. Healthy young participants (Mage = 18.58 years old) were randomly assigned to either a stress condition or control condition. Executive control, and the inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α, were measured before and after the social stress induction or control task. Regression analyses (stress condition, n = 20; control condition, n = 16) demonstrated that in the stress condition only, greater increases in interleukin-6 were associated with more depressive symptoms. Additional analyses in the stress condition (n = 16) indicated that greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6. These findings are consistent with Social Signal Transduction Theory of Depression and with the hypothesis that impairment in executive control during times of stress may be one process that contributes to stress-induced inflammatory activity, which may in turn increase risk for depression.Lay SummarySocial Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression, and that cognitive processes play a role in structuring these effects. Consistent with this theory, greater social stress-induced increases in the inflammatory cytokine interleukin-6 were associated with more depressive symptoms. In addition, greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6, highlighting potential links between social stress, cognition, inflammation, and depression.

The plasmatic and salivary levels of IL-1β, IL-18 and IL-6 are associated to emotional difference during stress in young male

Saliva collection is considered a non-invasive method to detect inflammatory markers in response to emotional states within natural social contexts. Numerous studies have prompted an important role of cytokines in modulating distinct aspects of social and emotional behavior. The aim of this study was to investigate the reliability of plasma and saliva as investigative tools for measure some inflammatory marker levels (CRP, IL-1β, IL-18, and IL-6). At the same time, the relationships between these markers and emotional states in response to a socio-cognitive stress (Academic Exam, AE), were considered. It was demonstrated that the plasma and saliva concentrations of all immune-mediators analyzed were significantly related across the socio-cognitive stress. In addition, when there was a close correlation to AE, the anger state, the IL-1β, the IL-18 salivary and plasmatic concentrations were significantly higher, while they decreased during the AE. On the other hand, the anxiety state and the IL-6 levels significantly increased throughout the AE. The IL-1β and IL-6 were positively associated to the anger and the anxiety state, respectively. In conclusion, our data highlight that different immune markers are similarly detectable in plasma and saliva during socio-cognitive stress. Also, they could be related to different emotional responses.

Characteristics of Perceived Stress and Salivary Levels of Secretory Immunoglobulin A and Cortisol in Japanese Women With Premenstrual Syndrome

Background:

Several studies have demonstrated the associations between Premenstrual Syndrome and perceived stress, and no studies quantifying stress based on biochemical parameters have been conducted.

Objectives:

The objective of this study was to examine the changes in biochemical parameters of stress and measured perceived stress during the menstrual cycle of women with premenstrual syndrome.

Patients and Methods:

A longitudinal observational study was conducted in 2010 in the Kansai region of Japan. Thirteen women with premenstrual syndrome and 11 controls, all with regular menstrual cycles, participated in this study. Salivary secretory immunoglobulin A (S-IgA) and cortisol levels were measured as biochemical parameters, and scores on the Stress Check List KM (SCL-KM) (Cronbach’s α in this study ranged from 0.76 to 0.84) were used to indicate perceived stress through two complete menstrual cycles. Before stress measurements were taken, premenstrual, menstrual and postmenstrual phases were confirmed based on records of basal body temperature across two menstrual cycles. Data analysis was performed using the Student’s t-test, analysis of variance with repeated measures, and Pearson’s correlation coefficient, as appropriate.

Results:

Both the postmenstrual S-IgA concentration and secretion rate were significantly lower in the group with premenstrual syndrome than in controls (P < 0.05). Premenstrual S-IgA concentrations were significantly higher than postmenstrual levels in the group with premenstrual syndrome (P < 0.05). No significant differences in cortisol levels were seen in either group during any phase. Premenstrual and postmenstrual phase SCL-KM scores were significantly higher in the group with premenstrual syndrome than in controls (P < 0.05). No significant changes in the SCL-KM scores were observed among menstrual cycle phases in either group. Postmenstrual S-IgA levels were negatively correlated with the SCL-KM score (P < 0.05).

Conclusions:

The stress due to psychosomatic changes in the menstrual cycle is associated with premenstrual syndrome. Measures of S-IgA, rather than cortisol or subjective responses to stress, may be most closely associated with PMS.

Salivary markers of inflammation in response to acute stress

There is burgeoning interest in the ability to detect inflammatory markers in response to stress within naturally occurring social contexts and/or across multiple time points per day within individuals. Salivary collection is a less invasive process than current methods of blood collection and enables intensive naturalistic methodologies, such as those involving extensive repeated measures per day over time. Yet the reliability and validity of saliva-based to blood-based inflammatory biomarkers in response to stress remains unclear. We review and synthesize the published studies that have examined salivary markers of inflammation following exposure to an acute laboratory stressor. Results from each study are reviewed by analyte (IL-1β, TNF-α, IL-6, IL-2, IL-4, IL-10, IL-12, CRP) and stress type (social-cognitive and exercise-physical), after which methodological issues and limitations are addressed. Although the literature is limited, several inflammatory markers (including IL-1β, TNF-α, and IL-6) have been reliably determined from saliva and have increased significantly in response to stress across multiple studies, with effect sizes ranging from very small to very large. Although CRP from saliva has been associated with CRP in circulating blood more consistently than other biomarkers have been associated with their counterparts in blood, evidence demonstrating it reliably responds to acute stress is absent. Although the current literature is presently too limited to allow broad assertion that inflammatory biomarkers determined from saliva are valuable for examining acute stress responses, this review suggests that specific targets may be valid and highlights specific areas of need for future research.

Allostatic load model associated with indoor environmental quality and sick building syndrome among office workers

This study investigates whether indoor environmental quality (IEQ) influences allostatic load (AL) and whether AL can be a predictor for sick building syndrome (SBS). We also assessed and compared the associations between AL and SBS versus 8-hydroxydeoxyguanosine (8-OHdG) and SBS. A total of 115 office workers from 21 offices completed self-reported SBS questionnaires, and provided 11 biomarkers for their AL. Multiple linear regressions and logistic regression analysis were applied to examine the correlations between IEQ and AL or 8-OHdG and between AL or 8-OHdG and SBS, respectively. Our data revealed that the neuroendocrine system was correlated with CO₂, the difference between indoor and outdoor CO₂ levels (dCO₂), and the indoor-outdoor ratio of CO₂ (CO₂ I/O). Metabolic system effects were associated with illumination. The relationships between illumination, CO₂, dCO₂, CO₂ I/O and 8-OHdG were consistent with those and AL in specific systems. Furthermore, we found that risks for SBS syndromes were related with neuroendocrine and metabolic system of the AL. 8-OHdG was associated with eye dryness or irritation, eye tiredness and vomiting. We conclude that IEQ significantly influences AL and that AL can be a predictor for reporting SBS with information on system-specific effects.

Cortisol and secretory immunoglobulin A response to stress in German shepherd dogs

The aim of the study was to determine whether cortisol and secretory Immunoglobulin A (sIgA) could be used as an indicator of acute stress in both young and adult dogs. Seventeen German shepherd puppies were exposed to the Puppy test (challenge test) at the age of seven weeks. This test has been routinely used to assess the future working ability of potential police dogs. In addition, ten adult females were subjected to 4 minutes of defense training under stressful conditions. Saliva was collected from the puppies and adult females before testing and 20 minutes after the start of testing, using a cotton swab held for 1-2 minutes in each dog's mouth. Cortisol concentrations increased after the test compared to the control sample both in puppies and the adult females. However adult females showed a significant decrease in sIgA after defense training while puppies showed a tendency of increase in sIgA. We propose that salivary cortisol could be used as an indicator of stress in puppies during early ontogeny. It is not yet clear whether sIgA could be used as a useful indicator of short-term stress in dogs.

Psycho-physical and neurophysiological effects of qigong on depressed elders with chronic illness

This randomized controlled trial examined the psychological, physical, and neurophysiological effects of a qigong exercise program on depressed elders with chronic medical illness. The experimental group (n = 21, 80 ± 7 years) was given a 12-week qigong exercise program, while the comparison group (n = 17, 81 ± 8 years) participated in a newspaper reading program with the same duration and frequency. Measurement of depression symptoms, psychosocial functioning, muscle strengths, salivary cortisol, and serum serotonin was conducted. At 12 weeks, the qigong group had significant reduction in depressive symptoms (F = 11.68; p < 0.025). Improvement in self-efficacy (F = 4.30; p < 0.050), self-concept of physical well-being (F = 6.82; p < 0.025), and right-hand grip strength (F = 5.25; p = 0.034) was also found when compared with the comparison group. A change in salivary cortisol level was found marginally insignificant between groups (F = 3.16; p = 0.087). However, a decreasing trend of cortisol level was observed. The results provided preliminary evidence for the hypotheses that the antidepressive effect of qigong exercise could be explained by improvement in psychosocial functioning and possibly down-regulation of hyperactivity of the hypothalamic-pituitary-adrenal axis.

Equivalence of students' scores on timed and untimed anatomy practical examinations

Untimed examinations are popular with students because there is a perception that first impressions may be incorrect, and that difficult questions require more time for reflection. In this report, we tested the hypothesis that timed anatomy practical examinations are inherently more difficult than untimed examinations. Students in the Doctor of Physical Therapy program at Thomas Jefferson University were assessed on their understanding of anatomic relationships using multiple-choice questions. For the class of 2012 (n = 46), students were allowed to circulate freely among 40 testing stations during the 40-minute testing session. For the class of 2013 (n = 46), students were required to move sequentially through the 40 testing stations (one minute per item). Students in both years were given three practical examinations covering the back/upper limb, lower limb, and trunk. An identical set of questions was used for both groups of students (untimed and timed examinations). Our results indicate that there is no significant difference between student performance on untimed and timed examinations (final percent scores of 87.3 and 88.9, respectively). This result also held true for students in the top and bottom 20th percentiles of the class. Moreover, time limits did not lead to errors on even the most difficult, higher-order questions (i.e., items with P-values < 0.70). Thus, limiting time at testing stations during an anatomy practical examination does not adversely affect student performance.

An increase in salivary interleukin-6 level following acute psychosocial stress and its biological correlates in healthy young adults

Although interleukin-6 (IL-6) has been investigated frequently in stress research, knowledge regarding the biological processes of IL-6 in association with psychosocial stress remains incomplete. This study focused on salivary IL-6 and reports its temporal variation and biological correlates following acute psychosocial stress. Fifty healthy young adults (39 male and 11 female students) were subjected to the psychosocial stress test 'Trier Social Stress Test' (TSST), wherein the participants were asked to deliver a speech and perform a mental arithmetic task in front of 2 audiences. Collection of saliva samples, measurement of heart rate, and assessment of negative moods by visual analogue scales were conducted before, during, and after TSST. Salivary IL-6 levels increased by approximately 50% in response to the TSST and remained elevated for 20 min after the stress tasks were completed. Cluster analyses revealed that individuals with sustained elevation of IL-6 levels following the TSST exhibited a lower cortisol response compared to individuals with lower IL-6 levels. In the correlation analyses, a greater IL-6 response was associated with a higher heart rate during the mental arithmetic task (r=.351, p<.05) and with a lower cortisol response (r=-.302, p<.05). This study demonstrates that salivary IL-6 levels are elevated for a relatively long period following acute psychosocial stress, and suggests that sympathetic activity and cortisol secretion are involved in elevation of salivary IL-6 levels.

Increased salivary immunoglobulin A and reduced α-amylase activity in whole saliva from spastic cerebral palsy individuals

BACKGROUND

Salivary immunoglobulin A (SIgA) together with innate defenses such as α-amylase, provides the 'first line of defense' against pathogens present at mucosal surfaces. This study aimed to evaluate salivary α-amylase and immunoglobulin A (IgA) in whole saliva of spastic cerebral palsy (CP) individuals.

METHODS

Whole saliva was collected from 22 CP and 24 sibling volunteers with no neurological damage control groups (CG) (aged 7-14 years). The salivary flow rate, total protein and SIgA concentrations, and α-amylase activity were determined.

RESULTS

The CP group presented higher salivary flow rate (35%) and lower total protein concentration (18%) compared with the CG (P ≤ 0.05). CPG had higher absolute (68%, μg SIgA/ml) and relative (55%, μg SIgA/mg prot and 108%, μg SIgA/min) concentrations of IgA compared with the CG (P ≤ 0.05). CPG had lower relative α-amylase activity (15% mg malt/mg prot and 33%, mg malt/min) compared with the CG (P ≤ 0.05).

CONCLUSION

This study concluded that CP individuals presented alterations in the profile of salivary proteins involved in the defense system of the oral cavity.

Reduction of mental distress in the dissection course by introducing the body donor experience through anatomical demonstrations of organ systems

The practice of dissection teaches students not only the foundations of anatomical knowledge but also encourages the development of professional competencies. Yet, the dissection of cadavers in the gross anatomy course can be a stress factor for medical students. There are a minor proportion of students who demonstrate strong emotional reactions in anticipation of being confronted with a cadaver. Therefore, in 2008, the authors implemented a voluntary course entitled, "Anatomical demonstrations of organ systems" (AD-OS) in advance of the dissection course to ease this psychological burden. The question of whether attendees of AD-OS showed less mental distress at the start of the dissection course compared with those that had not or only infrequently visited AD-OS was addressed. AD-OS attendees assessed their expected mental distress using a five-point Likert scale before starting the dissection course and a second time at the end of their first day, after they had been confronted with a cadaver. AD-OS was evaluated as excellent and the majority of students participated actively during teaching sessions. Overall, female students showed higher levels of mental distress. AD-OS attendees assessed themselves as being less burdened by mental distress than members of the control group. Longitudinal analysis revealed that students who visited AD-OS showed a marked decrease of their mental distress level, comparing prospective and retrospective ratings. This was significantly (P < 0.001; Z = -6.061) different from nonattendees or those who visited AD-OS only infrequently. AD-OS satisfied its intended teaching goals and proved that a step-by-step introduction of dissection through anatomical demonstrations helped to reduce the mental distress of students. Future studies are planned to measure mental distress with objective instruments.

The effect of emotional freedom techniques on stress biochemistry: a randomized controlled trial

This study examined the changes in cortisol levels and psychological distress symptoms of 83 nonclinical subjects receiving a single hour long intervention. Subjects were randomly assigned to either an emotional freedom technique (EFT) group, a psychotherapy group receiving a supportive interviews (SI), or a no treatment (NT) group. Salivary cortisol assays were performed immediately before and 30 minutes after the intervention. Psychological distress symptoms were assessed using the symptom assessment-45. The EFT group showed statistically significant improvements in anxiety (-58.34%, p < 0.05), depression (-49.33%, p < 0.002), the overall severity of symptoms (-50.5%, p < 0.001), and symptom breadth (-41.93%, p < 0.001). The EFT group experienced a significant decrease in cortisol level (-24.39%; SE, 2.62) compared with the decrease observed in the SI (-14.25%; SE, 2.61) and NT (-14.44%; SE, 2.67) groups (p < 0.03). The decrease in cortisol levels in the EFT group mirrored the observed improvement in psychological distress.

Influence of chewing force on salivary stress markers as indicator of mental stress

The aim of this study was to investigate the influence of chewing force on salivary stress markers (alpha-amylase activity, salivary cortisol level and secretory immunoglobulin A secretion rate) as indicators of mental stress. Participants comprised 20 healthy men. The first set of saliva specimens (S1) was collected at immediately after a 20-min rest to evaluate stress markers. As stress loading, the participants were required to perform arithmetic calculations for 20 min, after which the second set of saliva specimens (S2) was collected. Each participant was then required to chew a piece of tasteless gum for 10 min, after which the third set of saliva specimens (S3) was collected. After a 20-min rest, the fourth set of saliva specimens (S4) was collected. Weak, habitual and strong chewing forces were assigned. Change rates of stress markers between S2 and S3, and S2 and S4 were calculated. A significant difference was observed in the change rate of cortisol levels between S2 and S3. Cortisol level decreased more under strong chewing than under weak chewing. No significant differences were observed in the change rate of amylase activity or s-IgA secretion rate among the three chewing forces. The results suggest that differences in chewing force influence the salivary cortisol level of the three stress markers, and that a strong chewing force induces a greater reduction in mental stress than a weak one.

Changes in diurnal salivary cortisol levels in response to an acute stressor in healthy young adults

BACKGROUND

Knowledge of the diurnal cortisol response to acute stress in healthy individuals can help us better understand the physiological and health effects of chronic stress.

OBJECTIVE

To compare the diurnal patterns of cortisol secretion of 15 medical students 2 weeks before a major written examination (control phase) and 2 weeks later at the time of the examination (acute stress phase).

DESIGN

Interrupted time series within-subjects.

RESULTS

During the acute stress phase, less cortisol was secreted over the course of the day, as demonstrated by a more prolonged and steeper decline in cortisol levels. In addition, higher cortisol levels were present in the evening. Despite these changes in the usual diurnal pattern, overall exposure to cortisol remained the same for both phases.

CONCLUSIONS

The results of this study suggest that specific adaptations to the diurnal pattern of cortisol are made in the face of acute stress, important information for understanding cortisol regulation in health and illness.