Evidence of Differential Prediction of Anxiety and Depression by Diurnal Alpha-Amylase and Cortisol in Development.

Research and theory suggest an important role of neuroendocrine function in emotional development, particularly under conditions of elevated stress. We provide empirical data to clarify associations between alpha-amylase (AA) and cortisol as well as test the differential linkages among AA, cortisol, and symptoms of anxiety, depression, and posttraumatic stress in children. Children recruited from a low-income elevated violence community (n = 100; mean age = 10, SD = 0.64; 79% Latino; 67% received free or reduced lunch) were assessed on diurnal levels of AA and cortisol along with assessments of anxiety, depression, and posttraumatic stress symptoms (PTSS). Elevated anxiety symptoms were associated with steeper linear slopes of AA with higher levels of AA in the morning but lower levels of AA in the evening. Depression was associated with differential cubic trajectories of AA when PTSSs were included in the model. Anxiety also predicted differential cubic diurnal trends in cortisol, such that greater anxiety symptoms were associated with relatively higher levels of cortisol in the evening. Again, depression symptoms when PTSS were included predicted diurnal cubic trends with elevated depression associated with lower awakening and midday cortisol that reversed to higher evening cortisol compared to youth with fewer self-reported depression symptoms.

Salivary uric acid dynamics are associated with stress response hormones among African Americans in an urban sample.

Acute physiological responses to psychosocial stressors are a potential pathway underlying racial disparities in stress-related illnesses. Uric acid (UA) is a potent antioxidant that has been linked to disparities in stress-related illnesses, and recent research has shown that UA is responsive to acute social stress. However, an examination of the relationships between the purinergic system and other commonly measured stress systems is lacking. Here, we measure and characterize associations of salivary uric acid (sUA) with markers of hypothalamic-pituitary-adrenal (HPA) axis activation, sympathetic-adreno-medullar (SAM) axis activation, and acute inflammation. A community sample of 103 African Americans (33 male, 70 female) completed the Trier Social Stress Test to induce social-evaluative threat. Passive drool collected before, during, and after the stressor task provided salivary reactivity measures of UA (sUA), cortisol, dehydroepiandrosterone sulfate (DHEAS), salivary alpha amylase (sAA - a surrogate marker of SAM activity) and C-reactive protein (sCRP). Multiple regressions revealed that total activation of cortisol, DHEAS, and sCRP were each positively associated with higher total activation of sUA. Additionally, DHEAS reactivity was positively associated with sUA reactivity. Relationships between HPA-axis markers and sUA were especially observed among younger and male participants. Overall, findings suggest potential coordination of stress systems with sUA in response to acute stress, which may further the contributions of biological stress processes to racial health disparities.

Is Salivary Α-Amylase a Reliable Indicator of Psychological Status and Quality of Life in Patients with Oral Lichen Planus: a Case-Control Study.

BACKGROUND/AIMS: The objectives of our study were to determine salivary α-amylase activity (stress biomarker) and its association with psychological status and quality of life (QoL), disease duration and intensity of symptoms (pain/burning) in patients with OLP. METHODS: A total of 50 subjects participated in this case-control study: 30 patients with oral lichen planus (OLP); 20 control subjects. Unstimulated whole saliva (UWS) was collected between 9 and 10 am to avoid diurnal fluctuations. Psychological status was assessed using the Croatian validated version of the original Depression, Anxiety and Stress Scale (DASS-21). The impact of oral health on QoL was assessed using the Croatian version of the Oral Health Impact Profile Questionnaire (OHIP-CRO14). RESULTS: There was no statistically significant difference in salivary α-amylase activity between patients with OLP (N=30) and control subjects (N=20) (133813.3 vs. 166815.5 U/L, p=0.314; t-test). Depression, anxiety and stress showed no statistically significant difference between patients with OLP and control subjects (p=0.076, p=0.111, p=0.209; t-test). The patients with OLP had statistically significantly poorer QoL (total) compared to control subjects (p=0.004, t-test). There was a moderate positive correlation between symptom intensity (pain/burning) and poor QoL (total) (r=0.584, p<0.001), the OHIP-CRO14 dimension "physical pain" (r=0.661, p<0.001), "psychological impossibility" (r=0.555, p<0.01), "handicap" (r=0.546, p<0.01). CONCLUSION: Although salivary α-amylase showed no statistically significant difference between patients with OLP and control subjects, the patients with OLP had poorer psychological status (three times higher scores for depression and two times higher scores for anxiety) and poorer QoL compared to the control subjects. Recognising and treating mental disorders in patients with OLP is important in order to break the "vicious circle" and achieve a better QoL in these patients.

Fabrication of a salivary amylase electrochemical sensor based on surface confined MWCNTs/ß-cyclodextrin/starch architect for dental caries in clinical samples.

Salivary α-amylase (α-ALS) has drawn attention as a possible bioindicator for dental caries. Herein, combining the synergistic properties of multi-walled carbon nanotubes (MWCNTs), ß-cyclodextrin (ß-CD) and starch, an electrochemical sensor is constructed employing ferrocene (FCN) as an electrochemical indicator to oversee the progression of the enzymatic catalysis of α-ALS. The method involves a two-step chemical reaction sequence on a screen-printed carbon electrode (SPCE). X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscope (FE-SEM), and Dynamic light scattering (DLS) were used to characterize the synthesized material, while Static water Contact angle measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were performed to monitor each step of sensor fabrication. The electrochemical sensor permitted to detect α-ALS within the linear range of 0.5-280 U mL-1, revealing detection (LOD), and quantification (LOQ) values of 0.041 U mL-1, and 0.159 U mL-1, respectively. Remarkably, the sensor demonstrated exceptional specificity and selectivity, effectively discriminating against other interfering substances in saliva. Validation of the method involved analyzing α-ALS levels in artificial saliva with an accuracy range of 97 % to 103 %, as well as in real clinical saliva samples across various age groups.

The impact of virtual reality scenes on stress response characteristics of individuals with different personality traits.

Virtual reality based physical stress (VRPS) paradigms could eliminate the influence of social factors on participants, and it may be a desirable tool to explore the impact of personality traits on stress levels. In this study, we attempt to explore the effects of VRPS on stress response among individuals with different personality traits. Forty male participants with an average age of 22.79 ± 0.41 years were divided into two groups based on Harm Avoidance (HA) scores of Tridimensional Personality Questionnaire (TPQ), referred to as the Low-HA group and the High-HA group. The stress levels of the participants were assessed using salivary α-amylase (sAA) activity and heart rate variability (HRV) indices pre- and post-stress. The influence of personality traits on stress response among different groups was analyzed. VRPS significantly affected the sAA activity and HRV indicators of both groups. During and after stress, there were significant differences in sAA activity and HRV indicators between the two groups. The sAA levels and HRV indices of the Low-HA group were lower than those of the High-HA group. Furthermore, sAA levels and HRV indices were correlated with the scores of TPQ. VRPS scenarios elicit different stress responses on individuals with different harm avoidance personality traits. Stress evaluation based on VR scenarios presents potential in personality trait assessments, particularly for distinguishing between individuals with low and high HA tendencies.

The Use of Coffee Aroma for Stress Reduction in Postgraduate Dental Students.

OBJECTIVES: This study aimed to investigate the potential reduction of academic stress related to a graded oral presentation in postgraduate dental students using coffee aromatherapy. METHODS: Healthy postgraduate dental students in a seminar class were divided into coffee (n = 32) and control (n = 26) groups. There were 3 modes of aroma distribution: personal distribution with a coffee pad attached to a lanyard, a lanyard plus a personal fan for ventilation of the aroma, and the typical method of the diffuser to spread the aroma in the ambient air. Stress markers comprised levels of salivary alpha-amylase (sAA), cortisol (sCort), and chromogranin A (sCgA). Pulse rates were also measured. RESULTS: Levels of sAA increased 176.62% ± 30.26% between pre- and postpresentation in the control group. Inhaling coffee aroma during the presentation period significantly ameliorated sAA increase at 81.02% ± 14.90% (P = .015). sCort levels tended to decrease in the coffee group, but not significantly. Surprisingly, sCgA levels increased more in the coffee group. Also, pulse rates decreased in the coffee group (-2.07 ± 2.81 bpm) and increased in the control group (6.90 ± 3.22 bpm; P = .035). Subgroup analysis did not reveal differences in salivary markers amongst the 3 aroma distribution modes. CONCLUSIONS: Coffee aroma could have an anxiolytic effect on postgraduate dental students, as evidenced by changes in sAA levels and pulse rates. Personal aroma distribution was also a useful and effective mode of aromatherapy.

Nociception related biomolecules in the adult human saliva: A scoping review with additional quantitative focus on cortisol.

Nociception related salivary biomolecules can be useful patients who are not able to self-report pain. We present the existing evidence on this topic using the PRISMA-ScR guidelines and a more focused analysis of cortisol change after cold pain induction using the direction of effect analysis combined with risk of bias analysis using ROBINS-I. Five data bases were searched systematically for articles on adults with acute pain secondary to disease, injury, or experimentally induced pain. Forty three articles met the inclusion criteria for the general review and 11 of these were included in the cortisol-cold pain analysis. Salivary melatonin, kallikreins, pro-inflammatory cytokines, soluable TNF-α receptor II, secretory IgA, testosterone, salivary α-amylase (sAA) and, most commonly, cortisol have been studied in relation to acute pain. There is greatest information about cortisol and sAA which both rise after cold pain when compared with other modalities. Where participants have been subjected to both pain and stress, stress is consistently a more reliable predictor of salivary biomarker change than pain. There remain considerable challenges in identifying biomarkers that can be used in clinical practice to guide the measurement of nociception and treatment of pain. Standardization of methodology and researchers' greater awareness of the factors that affect salivary biomolecule concentrations are needed to improve our understanding of this field towards creating a clinically relevant body of evidence.

Effect of 1% H2O2 on Three Salivary Stress Biomarkers, Cortisol, Alpha-Amylase, and sIgA.

BACKGROUND: Due to the COVID-19 pandemic, several associations worldwide have been recommending the use of 1% hydrogen peroxide solution as a preprocedural mouth rinse before dental treatments to reduce viral load in saliva. This protocol is also employed in stress studies, especially in the context of dental treatment that uses salivary biomarkers as an indicator. However, the effect of 1% hydrogen peroxide as mouth rinse on salivary biomarkers remains unclear. OBJECTIVE: This study aims to investigate the effects of 1% hydrogen peroxide solution as a preprocedural mouth rinse on 3 salivary stress biomarkers-salivary cortisol, salivary secretory IgA, and salivary α-amylase-both on chemical influence and mechanical irrigation. MATERIALS AND METHODS: Ninety healthy participants with confirmed negative Reverse Transcription Polymerase Chain Reaction results for COVID-19 at most 2 days prior to the experiment were included in this study. All participants were randomly allocated into 3 groups: experimental (1% hydrogen peroxide solution), positive control (distilled water), and negative control (no mouth rinse). Saliva samples were collected before and after mouth rinsing with the respective solutions. Salivary biomarkers were analysed using specific enzyme-linked immunosorbent assay kits. RESULTS: Salivary cortisol and salivary α-amylase did not significantly differ before and after rinsing, whilst salivary sIgA levels decreased in all 3 groups. Nonetheless, there were no significant differences in the changes of these biomarkers across the 3 groups. CONCLUSIONS: This study shows that using 1% hydrogen peroxide solution as a preprocedural mouth rinse for universal precaution does not alter the levels of these 3 salivary biomarkers.

Comparison of distraction techniques using salivary biomarkers during local anaesthesia administration in children aged 3-5 years: A clinical study.

Aim: In paediatric dentistry, pain is adversely influenced by a child's level of anxiety. Ironically, the most common form of pain control used in dentistry, local anaesthesia, can itself produce anxiety. One of the techniques to overcome a child's anxiety is using distraction. The aim of the present study was to evaluate the effectiveness of distraction techniques, i.e. audio distraction (AD) and audio-visual distraction (AVD) by measuring salivary stress biomarker (salivary cortisol and salivary alpha-amylase) levels in 3-5 year-old children. Materials and Methods: Forty children aged 3-5 years were divided randomly into two groups; (Group I = AD, Group II = AVD). Cotton pellets were placed in the lingual vestibule to collect a sample of saliva. Children were then asked to wear overhead phones in the AD group, connected to a phone, and rhymes were played. In AVD, a cartoon movie was shown to the children using AV glasses. Simultaneously, local anaesthesia was administrated to children, after which another saliva sample was collected. Biomarker estimation was done using ELISA. Fisher's exact test was used for statistical analysis. Results: Statistically significant results were seen with Group II compared to Group I (cortisol-P = 0.009; salivary alpha-amylase-P = 0.03). Conclusion: Both distraction techniques are effective in reducing stress but compared to AD, AVD is more efficacious.

Inhibitory Potential of Different Bilberry (Vaccinium myrtillus L.) Extracts on Human Salivary α-Amylase.

Recently, consumer preferences for bilberries have increased markedly. This fact is probably related to their natural constituents, such as phenolic compounds including anthocyanins and tannins, as well as the vitamins and minerals they contain. Phenolic compounds are known for their numerous beneficial effects on human health. Moreover, bilberry fruits have been shown to inhibit the activity of carbohydrate hydrolyzing enzymes, which can significantly decrease the postprandial increase in blood glucose levels. Thus, the aim of the present study is to investigate the inhibitory effect of Vaccinium myrtillus L. extracts on key enzyme α-amylase, linked to type 2 diabetes. No data have been published on the inhibitory properties of Vaccinium myrtillus L. fruits growing wild in Bulgaria against carbohydrate enzymes. Bilberry extracts were analyzed for total polyphenols, total anthocyanin content, antioxidant activity and their inhibitory properties against α-amylase. The contents of flavonols, anthocyanins and stilbenes were determined by HPLC analysis. The identified flavonols in the analyzed bilberry extracts were mainly represented by quercetin derivatives as rutinoside. The predominant anthocyanins for both aqueous and organic solvents were delphinidin-3-galactoside and malvidin-3-glucoside. The results revealed that bilberry extracts are effective inhibitors of α-amylase, with IC50 values from 20.8 to 194.8 µg GAE/mL. All the samples proved to have antioxidant activity measured by three different in vitro assays (FRAP, CUPRAC and DPPH). The inhibitory properties of V. myrtillus L. extracts may provide a new direction in the development and research of new pharmaceuticals for the suppression of postprandial hyperglycemia in diabetic patients.

Relationship of cortisol and alpha amylase to behavioral engagement under three levels of negative evaluative psychosocial stress.

Despite that behavioral engagement is integral to mental health, surprisingly little is known about the relationship of psychosocial stress and behavioral engagement. The current study developed an observer-rated measure of behavioral engagement for lab-based stress inductions, then examined its relationship with stress-responsive biomarkers and affect. Young adults (N = 109, Mage=19.4, SDage=1.59, 57% female) completed one of three Trier Social Stress Test (TSST) conditions-non-stressful Control, Intermediate, or an Explicit Negative Evaluative-and at four timepoints provided self-reports of positive and negative affect and saliva samples for cortisol and salivary alpha-amylase (sAA). Trained study staff (experimenters and TSST judges) completed a programmed questionnaire measure of the novel behavioral engagement measure after the participants completed the TSST. Psychometric review and EFA of the behavioral engagement items resulted in a final 8-item measure with good interrater reliability and well-fitting 2-factor structure, capturing Persistence (4 items; loadings=.41-.89), and Quality of Speech (4 items; loadings=.53-.92). Results indicated that the relationship of positive affect growth and biomarker level to behavioral engagement varied substantially as a function of context: As negative evaluation level strengthened, behavioral engagement became more tightly associated with relative preservation of positive affect. For both cortisol and sAA, the relationship between biomarker levels (but not reactivity) and behavioral engagement varied significantly by condition, such that under milder conditions and elevated levels of biomarkers, engagement was greater, but under Explicit Negative Evaluation, and elevated levels of biomarkers, engagement was less, suggesting behavioral withdrawal. Findings reveal the critical role of context-especially negative evaluation-in the relationship of biomarkers with behavioral engagement.

Cananga odorata Aromatherapy Reduces Anxiety in Unexperienced Patients Hospitalized for Interventional Neuroradiology Procedures: A Randomized Control Trial.

The hospitalization and the unfamiliar experiences of patients in interventional radiology procedures cause a moderate to high levels of anxiety. This study was aimed to evaluate the anxiolytic effect of Cananga odorata essential oil (COE) aromatherapy in unexperienced patients hospitalized for interventional neuroradiology (INR) procedures. Forty-four patients admitted for their first INR procedure were randomly divided into COE and placebo control groups. COE or distilled water was dropped onto 2 pieces of mulberry paper and attached to the participant's gown at the shoulder level overnight. The main outcomes were observed from the morning salivary cortisol levels and salivary alpha-amylase activity after intervention. The Thai version of Spielberger State-Trait Anxiety Inventory (STAI) and the vital signs (blood pressure and heart rate) were also assessed before and after COE intervention as the secondary outcome. The demographic and baseline data of both groups did not show any significant difference. After intervention, COE group had a significantly lower salivary alpha-amylase activity than placebo control group. The post-intervention scores of Trait (STAI-T) and State (STAI-S) anxiety were significantly less than those of baseline in both groups. Interestingly, the COE group had a greater percentage reduction on STAI-T after intervention than placebo control group. No significant difference was observed in other outcomes. In addition, the salivary alpha-amylase activity was weak but showed significant correlation with STAI anxiety scores. This study indicates that COE aromatherapy reduces the saliva alpha amylase activity and STAI-T anxiety in unexperienced patients hospitalized for INR procedures.

Effects of sodium bicarbonate bath on the quality of sleep: An assessor-blinded, randomized, controlled, pilot clinical trial.

BACKGROUND: Sleep is fundamental to a healthy life, and sleep disorders are an important health issue in healthcare. Whole-body warm water bathing is a non-pharmacological, safe (non-invasive), and widely used method for comforting. Here, we explored the feasibility and preliminary effectiveness of sodium bicarbonate bath (SBB) on sleep quality. METHODS: Healthy adults without sleep disturbances were randomly assigned to shower baths (SHB), tap-water baths (TWB, placebo tablets), or SBB. All participants took a bath (shower, tap-water, or SBB) once a day for 10 min, after dinner, for 7 days. Sleepscan-derived sleep parameters, including total sleep time (TST), symptom questionnaires, and salivary α-amylase concentration were evaluated as outcome measures. RESULTS: Forty participants were enrolled (14, 13, and 13 in SHB, TWB, and SBB groups, respectively) and 38 participants completed the trial (13, 12, and 13, respectively). The recruitment, adherence, and completion rates were 90.9% (40/44), 95.0% (38/40), and 95.0% (38/40), respectively. The SBB group showed a significant increase (12.35 [mean]±10.07 [standard deviation] min) in the mean TST at 1-week post-intervention (p = 0.0041) than the SHB (-1.81 ± 14.58 min; p = 0.0231) and TWB (4.54 ± 10.97 min; p = 0.0377) groups. The TST scores at 1-week post-intervention, sleep onset latency, wake after sleep onset, and sleep efficiency were significantly different between the groups. Sleep satisfaction by questionnaire was significantly improved with intervention in the SBB group than that in the SHB and TWB groups. Salivary α-amylase levels significantly improved in the SBB and TWB groups than in the SHB group, with the change being greater in the SBB group. CONCLUSIONS: SBB for 7 days had positive effects that improved sleep quality of adults. Further studies are needed to examine the efficacy and safety of SBB for prolonged usage in people diagnosed with insomnia, using objective sleep measurements, and to investigate potential sleep-enhancing mechanisms of action.

Cross-sectional analysis reveals COVID-19 pandemic community lockdown was linked to dysregulated cortisol and salivary alpha amylase in children.

The COVID-19 pandemic altered everyday life starting in March 2020. These alterations extended to the lives of children as their normal routines were disrupted by community lockdowns, online learning, limited in-person social contact, increased screen time, and reduced physical activity. Considerable research has investigated the physical health impact of COVID-19 infection, but far fewer studies have investigated the physiological impact of stressful pandemic-related changes to daily life, especially in children. The purpose of this study was to leverage an ongoing clinical trial to investigate physiological consequences associated with chronic stress of pandemic community lockdown on children. As a part of the clinical trial, children provided saliva samples. Saliva samples were analyzed for cortisol and salivary alpha amylase (sAA) content. This secondary cross-sectional analysis included 94 preadolescent children located within the Greater Boston, Massachusetts community. Children participated in the study either before, during, or following the pandemic community lockdown to form three groups for comparison. In response to chronic stress caused by the pandemic community lockdown, participants demonstrated dysregulation of fast-acting catecholamine response of the locus-coeruleus-norepinephrine system and slower-acting glucocorticoid response, resulting in an asymmetrical relationship of hypocortisolism (M = 0.78 ± 0.19 µg/mL, p < 0.001) paired with higher sAA (M = 12.73 ± 4.06 U/mL, p = 0.01). Results suggest that the abrupt COVID-19 disruption to daily life, including the stressful experience of community lockdown, had physiological effects on typically developing children. Further research is required to investigate mental health outcomes of children following the chronic stress of the pandemic community lockdown.

Assessment of salivary alpha amylase and mucin-4 before and after non-surgical treatment of peri-implant mucositis.

BACKGROUND: The present study was based on the null hypothesis that there is no difference in clinicoradiographic parameters and whole salivary alpha amylase (AA) and mucin-4 levels before and after non-surgical mechanical debridement (NSMD) of patients with peri-implant mucositis (PM). The aim was to assess whole salivary AA and mucin-4 levels before and after treatment of PM. METHODS: Patients with PM (Group-1) and individuals without peri-implant diseases (Group-2) were included. Demographic data was collected and peri-implant modified plaque and bleeding indices (mPI and mBI, respectively), probing depth (PD) and crestal bone loss were measured at baseline. Levels of AA and mucin-4 were assessed in unstimulated whole saliva samples. All patients underwent full-mouth non-surgical periodontal therapy (NSPT) and NSMD; and clinical parameters and salivary biomarkers were re-assessed after 3 months. Level of significance was set at P < 0.01. RESULTS: Twenty-six and 32 individuals were included in groups 1 and 2, respectively. None of the participants had periodontitis. At baseline clinical periodontal parameters (PI [P < 0.001], GI [P < 0.001], clinical AL [P < 0.001] and PD [P < 0.001]) were significantly high in Group-1 than Group-2. At 3-month follow-up, there was a statistically significant reduction in clinical periodontal and peri-implant parameters (PI [P < 0.01], GI [P < 0.01], and PD [P < 0.01]) in Group-1 compared with their baseline values. At baseline, salivary AA levels were significantly high in Group-1 than Group-2 (P < 0.01). At 3-month follow-up, there was no significant difference in whole salivary AA levels among patients in groups 1 and 2. CONCLUSIONS: The AA and mucin-4 levels are potential biomarkers for evaluation of peri-implant diseases including PM. Mechanical instrumentation continues to be the most predictable treatment option for the management of peri-implant diseases.

Decreased salivary α-amylase activity responding to citric acid stimulation in Myasthenia gravis with malnutrition.

OBJECTIVES: Malnutrition, defined according to Nutritional risk screening (NRS 2002), is commonly observed in patients of Myasthenia gravis (MG), a neuromuscular disorder manifested by varied degrees of skeletal muscle weakness. Because biochemical composition of saliva changes in correspondence to alterations in nutritional status, we tested our hypothesis that a certain saliva component(s) might serve as a biomarker(s) for nutrition status of MG, particularly for those MG patients with high risk of malnutrition. MATERIALS AND METHODS: 60 MG patients and 60 subjects belonging to the healthy control group (HCG) were enrolled in this case-control study. The salivary α-amylase (sAA) activity, salivary flow rate (SFR), pH, total protein density (TPD), and the concentrations of chloride and calcium ions in MG group with or without malnutrition were measured before and after citric acid stimulation. Thereafter, the relationship between sAA activity and BMI was determined in MG and HCG. RESULTS: Compared with HCG, more patients with malnutrition, increased TPD and chloride and calcium concentrations but decreased pH value and SFR both before and after acid stimulation, as well as reduced sAA activity, pH and TPD responses to acid stimulation. MG with malnutrition showed decreased sAA activity and TPD responding to acid stimulation compared with those without malnutrition. Compared with normal BMI, sAA activity response to acid stimulation was reduced in low BMI. There was a significant strong positive correlation between the ratio of sAA activity and BMI in MG. CONCLUSIONS: Salivary biochemical characteristics are abnormally altered in MG with malnutrition. Altered sAA activity responding to acid stimulation was associated with malnutrition. CLINICAL RELEVANCE: Decreased sAA activity responding to acid stimulation can reflect malnutrition state and may be one potential screening marker for MG patients with high risk of malnutrition.

Mercury thermometer-inspired test strip for concentration cell-based potentiometric detection of salivary α-amylase.

In this work, we report on the mercury thermometer-inspired test strip for potentiometric detection of salivary α-amylase (sAA). The test strip contains a reaction chamber and two split channels, which are connected by a curved hydrophobic channel. The detection of sAA is based on sequential two-step reactions with preloaded reagents on the test strip. In the first step, maltose is produced by catalyzing the hydrolysis of starch using sAA in the reaction chamber. In the second step, the test strip is shaken to introduce the reaction mixture to the split channels under the inertia force, similar to the operation of a mercury thermometer. In one split channel, maltose reduces [Fe(CN)6]3- to [Fe(CN)6]4- under the alkaline condition, while the reaction hardly occurs in the other split channel with the neutral condition. This leads to a difference in the ratio of [Fe(CN)6]3-/[Fe(CN)6]4- between the two channels and therefore a potential difference that can be measured and correlated to sAA concentration. Using this test strip, sAA in the human saliva sample was quantitatively analyzed within 2 min. The application of this technique in the psychological evaluation was also demonstrated.

Diurnal pattern of salivary alpha-amylase and cortisol under citric acid stimulation in young adults.

Background: Saliva composition has diurnal variations. Citric acid stimulation plays a major role in the change of salivary flow rate and salivary composition. However, diurnal variations and sex differences in salivary alpha-amylase (sAA), pH, salivary flow rate (SFR), and salivary cortisol before and after citric acid stimulation remain unclear. Methods: We recruited 30 healthy volunteers, including 15 women (24.7 ± 1.0 years old) and 15 men (25.3 ± 1.3 years old). At four time points (T1, 7:00; T2, 10:00; T3, 16:00; and T4, 20:00), saliva was collected from healthy volunteers before and after citric acid stimulation; and sAA, pH, SFR and salivary cortisol were measured and compared between men and women. Results: There were circadian fluctuations in sAA activity, SFR, pH, and cortisol level both before and after citric acid stimulation, and the diurnal fluctuations of these indexes were not affected by citric acid stimulation. There were significant differences in salivary cortisol between men and women before and after acid stimulation in T1. Neither SFR nor pH showed sex-related differences before or after acid stimulation. The variation trend of sAA activity was contrary to that of cortisol, with a significant negative correlation. Conclusions: Our data suggest that sAA and cortisol showed diurnal fluctuation, and the variation characteristics of male and female under resting state and acid stimulation were basically the same. The variation trend of salivary alpha-amylase activity was opposite to that of cortisol, with significant negative correlation. Our findings may enable the selection of the correct sampling time for research and the selection of appropriate sampling strategies in studies investigating chronic psychosocial conditions.

Physiological stress in response to multitasking and work interruptions: Study protocol.

BACKGROUND: The biopsychological response patterns to digital stress have been sparsely investigated so far. Important potential stressors in modern working environments due to increased digitalization are multitasking and work interruptions. In this study protocol, we present a protocol for a laboratory experiment, in which we will investigate the biopsychological stress response patterns to multitasking and work interruptions. METHODS: In total, N = 192 healthy, adult participants will be assigned to six experimental conditions in a randomized order (one single-task, three dual-task (two in parallel and one as interruption), one multitasking, and one passive control condition). Salivary alpha-amylase as well as heart rate as markers for Sympathetic Nervous System Activity, heart rate variability as measure for Parasympathetic Nervous System (PNS) activity, and cortisol as measure for activity of the hypothalamic-pituitary adrenal (HPA) axis will be assessed at six time points throughout the experimental session. Furthermore, inflammatory markers (i.e., IL-6, C-reactive protein (CRP), and secretory immunoglobulin-A) will be assessed before and after the task as well as 24 hours after it (IL-6 and CRP only). Main outcomes will be the time course of these physiological stress markers. Reactivity of these measures will be compared between the experimental conditions (dual-tasking, work interruptions, and multitasking) with the control conditions (single-tasking and passive control). DISCUSSION: With this study protocol, we present a comprehensive experiment, which will enable an extensive investigation of physiological stress-responses to multitasking and work interruptions. Our planned study will contribute to a better understanding of physiological response patterns to modern (digital) stressors. Potential risks and limitations are discussed. The findings will have important implications, especially in the context of digital health in modern working and living environments.

Assessment of salivary alpha-amylase and cortisol as a pain related stress biomarker in dogs pre-and post-operation.

BACKGROUND: The use of salivary biomarkers has garnered attention because the composition of saliva reflects the body's physiological state. Saliva contains a wide range of components, including peptides, nucleic acids, electrolytes, enzymes, and hormones. It has been reported that salivary alpha-amylase and cortisol are biomarkers of stress related biomarker in diseased dogs; however, evaluation of salivary alpha-amylase and cortisol pre- and post- operation has not been studied yet. The aim of this study was to evaluate salivary alpha-amylase and cortisol levels in dogs before and after they underwent surgery and investigate the association between the salivary alpha-amylase and cortisol activity and pain intensity. For this purpose, a total of 35 dogs with disease-related pain undergoing orthopedic and soft tissue surgeries were recruited. Alpha-amylase and cortisol levels in the dogs' saliva and serum were measured for each using a commercially available canine-specific enzyme-linked immunosorbent assay kit, and physical examinations (measurement of heart rate and blood pressure) were performed. In addition, the dogs' pre- and post-operative pain scores determined using the short form of the Glasgow Composite Measure Pain Scale (CMPS-SF) were evaluated. RESULTS: After surgery, there was a significant decrease in the dogs' pain scores (0.4-fold for the CMPS-SF, p < 0.001) and serum cortisol levels (0.73-fold, p < 0.01). Based on their pre-operative CMPS-SF scores, the dogs were included in either a high-pain-score group or a low-pain-score group. After the dogs in the high-pain-score group underwent surgical intervention, there was a significant decrease in their CMPS-SF scores and levels of salivary alpha-amylase, serum alpha-amylase, and serum cortisol. Additionally, there was a positive correlation between salivary alpha-amylase levels and CMPS-SF scores in both the high- and low-pain-score groups. CONCLUSIONS: The measurement of salivary alpha amylase can be considered an important non-invasive tool for the evaluation of pain-related stress in dogs.