Saliva Concentrations Research Articles

Psychological Stress and its relationship to Periodontal flora and salivary Nitrite/Nitrate

ObjectivePsychological stress can be a common risk factor for the development of oral and systemic disease; therefore, analysis of a pathophysiologic mechanisms that may explain this association may be significant in planning preventive strategies. The aim of this study was to investigate the association amongst academic stress, periodontal health, and salivary cortisol and nitrite and nitrate levels in a sample of university students. MethodsParticipants (N = 14) were classified into 2 groups according to their exposure to academic stress due to periods of university exams (n = 6 and n = 8, respectively). All participants were subjected evlauted for their behavioural, psychological, and anthropometric parameters, as well as an oral health examination. A real-time polymerase chain reaction analysis in samples of saliva and plaque was used to detect Prevotella intermedia and Veillonella dispar as well as the total bacterial count. Nitrite/nitrate ratio (NR ratio) and cortisol in saliva were evaluated by enzyme-linked immunosorbent assay. ResultsFull Mouth Bleeding Score, Full Mouth Plaque Score, and Gingival Index were significantly higher in the group exposed to academic stress. Nitrite was directly related to the presence of V dispar (coefficient, 0.13; P = .00; CI, 0.07 to 0.19) and inversely related to total bacterial count (coefficient, −0.07; P = .012; CI, −0.13 to 0.02). NR ratio was directly related to V dispar (coefficient, 4.35; P = .010; 95% CI, 1.35 to 7.36) and inversely related to total bacterial count (coefficient, −4.05; P = .018; 95% CI, −7.32 to 0.86). ConclusionsThese results confirm the importance of stress on periodontal health and salivary nitrite concentration and highlight a potential differential role of specific bacteria on nitrite concentration in saliva.

Complexity of Translating Analytics to Recent Cannabis Use and Impairment.

While current analytical methodologies can readily identify cannabis use, definitively establishing recent use within the impairment window has proven to be far more complex, requiring a new approach. Recent studies have shown no direct relationship between impairment and Δ9-tetra-hydrocannabinol (Δ9-THC) concentrations in blood or saliva, making legal "per se" Δ9-THC limits scientifically unjustified. Current methods that focus on Δ9-THC and/or metabolite concentrations in blood, saliva, urine, or exhaled breath can lead to false-positive results for recent use due to the persistence of Δ9-THC well outside of the typical 3-4 h window of potential impairment following cannabis inhalation. There is also the issue of impairment due to other intoxicating substances-just because a subject exhibits signs of impairment and cannabis use is detected does not rule out the involvement of other drugs. Compounding the matter is the increasing popularity of hemp-derived cannabidiol (CBD) products following passage of the 2018 Farm Bill, which legalized industrial hemp in the United States. Many of these products contain varying levels of Δ9-THC, which can lead to false-positive tests for cannabis use. Furthermore, hemp-derived CBD is used to synthesize Δ8-THC, which possesses psychoactive properties similar to Δ9-THC and is surrounded by legal controversy. For accuracy, analytical methods must be able to distinguish the various THC isomers, which have identical masses and exhibit immunological cross-reactivity. A new testing approach has been developed based on exhaled breath and blood sampling that incorporates kinetic changes and the presence of key cannabinoids to detect recent cannabis use within the impairment window without the false-positive results seen with other methods. The complexity of determining recent cannabis use that may lead to impairment demands such a comprehensive method so that irresponsible users can be accurately detected without falsely accusing responsible users who may unjustly suffer harsh, life-changing consequences.

Changes of Salivary Concentration of IL-6 and TNF-Α in Early Childhood Caries

Background: Early childhood caries is a biofilm-dependent, critical, widespread health problem in both developing and industrialized countries. The interleukin-6 (IL-6) has several roles in the body's response to inflammation and tissue damage. TNF-α is a pleiotropic cytokine that acts as a pro-inflammatory cytokine. Aim of Study: The purpose of this research was to assess the salivary concentrations of TNF-α and IL-6 in children with dental caries and study the correlation between cytokines and DMFs index. Materials and Methods: Eighty children aged four and five took part in the study. Forty children with ECC served as the research group, whereas 40 caries-free children of the same age and gender served as the control group. Clinical parameters were assessed after an oral examination and measurement. All participants had saliva samples obtained. IL-6 and TNF-α concentrations in saliva were estimated using an ELISA test. Results: The current study found a significant elevation (P<0.05) in mean levels of TNF-α and IL-6 among children with ECC in comparison to caries free children. Moreover, there is significant positive correlation between IL-6 and TNF-α levels in caries children. Conclusion: Based on these results, it seems likely that elevated levels of TNF-α and IL-6 are involved in ECC.

Correlation between Oxidative Stress Markers and Periodontal Disease in Dogs.

In dogs, periodontal disease (PD) is a highly common condition whose prevalence rises significantly with age. Studies on rats with experimentally induced PD and human clinical trials have found an association between oxidative stress (OS) and PD, as has been observed in many other inflammatory disorders. The objective of this research was to assess the main indicators of oxidative stress detected in the saliva of dogs and to compare them to the degree of inflammation and tartar amount on their teeth and gums. By identifying these correlations, we intended to identify early-stage PD markers that would allow us to diagnose the condition in dogs without requiring for invasive or traumatic procedures. The antioxidant enzyme superoxide dismutase (SOD), total antioxidant capacity (TAC), malondialdehyde (MDA) and 8-hydroxyguanosine (8OHG), matrix metalloproteinase-8 (MMP8), and the quantity of total proteins are the markers that have been investigated in order to accomplish these objectives. The appearance of specific forms of periodontal disease has been confirmed by an increase in the saliva concentration of MMP8, a marker commonly used in the diagnosis of these pathologies in humans. The study was carried out on 22 dogs divided in a control group (C) and study groups (S), the second one being divided into three subgroups according to the severity of the gum inflammation and the presence or absence of tartar: S1-small accumulation of tartar, lack of infection-related signs; S2-moderate accumulation of tartar, gums swollen, red, and bled easily; S3-significant accumulation of tartar; gums bright red and bleeding; marked pain and halitosis. A correlation between the concentration of the tested parameters and the severity of the local appearance of the gum and teeth was noted. In comparison to the results of individuals from the control group, MMP8 reported increases of 1.2, 2, and 3.7 times, respectively, in the case of individuals from subgroups S1, S2, and S3. Oxidative stress is caused by inflammatory processes in the oral cavity. The presence of oxidative stress was demonstrated by the evaluation of different indicators in the saliva: an increase in the general antioxidant status, which was associated with an increase in SOD activity; intensification of the lipid peroxidation processes, as demonstrated by the accumulation of the MDA peroxidation product; and an increase in the DNA oxidation processes, as demonstrated by the accumulation of the oxidation product 8OHdG. In consequence, it was observed that there were up to 2-fold increases in protein levels, total antioxidant activity, SOD, and MDA, and up to 8.6-fold increases in the case of 8-OHdG when comparing dogs from the S3 group (significant tartar accumulation; bright red and bleeding gums; marked pain and halitosis) to those in the control group.

An ImmunoFET Coupled with an Immunomagnetic Preconcentration Technique for the Sensitive EIS Detection of HF Biomarkers.

We propose a new strategy using a sandwich approach for the detection of two HF biomarkers: tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). For this purpose, magnetic nanoparticles (MNPs) (MNPs@aminodextran) were biofunctionalized with monoclonal antibodies (mAbs) using bis (sulfosuccinimidyl) suberate (BS3) as a cross-linker for the pre-concentration of two biomarkers (TNF-α and IL-10). In addition, our ISFETs were biofunctionalized with polyclonal antibodies (pAbs) (TNF-α and IL-10). The biorecognition between pAbs immobilized on the ISFET and the pre-concentrate antigen (Ag) on MNPs was monitored using electrochemical impedance spectroscopy (EIS). Our developed ImmunoFET showed a low detection limit (0.03 pg/mL) toward our target analyte when compared to previously published electrochemical immunosensors. It showed a higher sensitivity than for other HF biomarkers. Finally, the standard addition method was used to determine the unknown concentration in artificial saliva. The results matched with the expected values well.

A randomised controlled trial assessing the effects of weather sensitivity profile and walking in nature on the psychophysiological response to stress in individuals with coronary artery disease. A study protocol

BackgroundThe following protocol pertains to a pioneer study, aiming to investigate how weather sensitivity and walking in different environments affects the psychophysiological responses to the stress of individuals with coronary artery disease (CAD) during rehabilitation (WE_SENSE_THE_NATURE). This randomised control trial will provide fresh insight on the influence of the environmental exposure in CAD patients, as it is seldom investigated in association to the disease. Additionally, findings on the link between personality traits and cognitive functions (especially cognitive flexibility), and weather sensitivity may help reveal a fine-grained perspective on the treatment possibilities for individuals with CAD at risk to stress-vulnerability.MethodsThe proposed protocol is for a randomised control trial among individuals attending a cardiac rehabilitation program. We aim to recruit 164 individuals, collecting information related to demographic characteristics, weather sensitivity, functional capacity, personality traits, subjective mental health status, cognitive function, and basal cortisol level of participating individuals. Basal cortisol level refers to cortisol concentration in saliva and will be tested in the morning and the afternoon prior to the day of the experiment. After baseline measurements, the patients will be randomly assigned to either walking outdoors or walking indoors. All measures and their sequential order will remain the same within each group, while the treatment condition (i.e., walking environment) will vary between groups. On the day of the experiment, hemodynamic parameters (assessed via 6-hour blood pressure measurements), stress level (consisting of assessments of cortisol level), and mood (assessed using visual analogues scale) will be registered. Cold stress test will be administered to evaluate the effect of walking in different environments.DiscussionThe outcomes of this study may have direct clinical applications for the use of different types of exercise environments in cardiac rehabilitation programs. Awareness about the potential influence of weather sensitivity on the psychophysiological reactions to stress in individuals with CAD may contribute to a timely planning and implementation of actions leading to improved medical care services and preventive measures, especially considering the expected weather oscillations and extreme weather events due to unfolding of the climate change.Trial registrationThis protocol has been retrospectively registered in ClinicalTrials.gov with identifier code: NCT06139705 on November 20, 2023.

Hollow nanocages heterostructured NiCo-LDH/MWCNTs electrocatalyst for highly sensitive and non-invasive detection of saliva glucose

Monitoring salivary glucose has gained increased attention as a non-invasive approach to prevent and diagnose diabetes. Since the glucose concentration in saliva is lower than that in blood, the development of effective electrocatalysts for highly sensitive glucose detection is thus of great significance. In this study, a hollow nanocage from NiCo-layered double hydroxides (LDH) modified with multi-walled carbon nanotubes (MWCNTs) is designed and further employed as the sensing material to construct a novel non-enzymatic glucose electrochemical sensor with high sensitivity. It is synthesized by utilizing pre-synthesized zeolitic imidazolate framework (ZIF-67)/MWCNTs as a sacrificial template and subsequently conducting a simple solvent-thermal reaction with Ni(NO3)2. Such a hollow nanocage preserves the polyhedral framework structure of the used precursor, where the hollow frame-like structure of NiCo-LDH offers accessible catalytic sites, and MWCNTs provides good conductivity. Their combination brings in a bridging effect between MWCNTs and NiCo-LDH, further leading to a large electrochemical active area and excellent catalytic activity of this hollow nanocage. The constructed sensor exhibits a detection limit as low as 0.03 μM for the glucose detection as well as wide linear ranges of 0.1–3000 μM and 3000–9231.8 μM, corresponding to the sensitivity of 2.55 and 1.15 μA mM−1 cm−2, respectively. Moreover, this sensor enables the tracking of glucose concentration change in salivary before and after food intake. This work offers new highly sensitive sensing materials and potentially valuable approaches for non-invasive glucose detection.

Disposable Voltammetric Immunosensor for Determination and Quantification of Biomarker CA 15-3 in Biological Specimens

A disposable voltammetric immunosensor was developed to measure breast cancer biomarker 15-3 (CA 15-3) in human saliva and serum samples. Screen-printed paper-based electrodes (f-SPE) previously fabricated by our research group using homemade conductive inks were used as transducers, which were later modified only with gold nanoparticles to immobilize anti-CA 15-3 antibodies. The sensor was operated using antigen–antibody interactions in conjunction with a redox species (ferrocyanide potassium) for the indirect determination of the CA 15-3 antigen. The device characterization involved atomic force microscopy (AFM) and electrochemical analysis. Optimization of the construction and response of the immunosensor was achieved at incubation times of 6 h for anti-CA 15-3, 1 h for bovine serum albumin, and 1 h for interaction with CA 15-3. The sensor displays a linear range between 2 and 16 U/mL, with a sensitivity of 0.012 μA/U mL−1, a limit of detection (LOD) of 0.56 U/mL, and a limit of quantification (LOQ) of 1.88 U/mL. The interfering substances minimally affected the signal, with 4.94% response variation, and the reproducibility of the immunosensor demonstrated a relative standard deviation (RSD) of 5.65%. The sensor successfully determined the CA 15-3 concentration in human serum and saliva, demonstrating its potential for clinical analysis.

The correlation of urea and creatinine concentrations in sweat and saliva with plasma during hemodialysis: an observational cohort study.

Urea and creatinine concentrations in plasma are used to guide hemodialysis (HD) in patients with end-stage renal disease (ESRD). To support individualized HD treatment in a home situation, there is a clinical need for a non-invasive and continuous alternative to plasma for biomarker monitoring during and between cycles of HD. In this observational study, we therefore established the correlation of urea and creatinine concentrations between sweat, saliva and plasma in a cohort of ESRD patients on HD. Forty HD patients were recruited at the Dialysis Department of the Catharina Hospital Eindhoven. Sweat and salivary urea and creatinine concentrations were analyzed at the start and at the end of one HD cycle and compared to the corresponding plasma concentrations. A decrease of urea concentrations during HD was observed in sweat, from 27.86 mmol/L to 12.60 mmol/L, and saliva, from 24.70 mmol/L to 5.64 mmol/L. Urea concentrations in sweat and saliva strongly correlated with the concentrations in plasma (ρ 0.92 [p<0.001] and 0.94 [p<0.001], respectively). Creatinine concentrations also decreased in sweat from 43.39 μmol/L to 19.69 μmol/L, and saliva, from 59.00 μmol/L to 13.70 μmol/L. However, for creatinine, correlation coefficients were lower than for urea for both sweat and saliva compared to plasma (ρ: 0.58 [p<0.001] and 0.77 [p<0.001], respectively). The results illustrate a proof of principle of urea measurements in sweat and saliva to monitor HD adequacy in a non-invasive and continuous manner. Biosensors enabling urea monitoring in sweat or saliva could fill in a clinical need to enable at-home HD for more patients and thereby decrease patient burden.

The Effect of Salivary Zinc Concentration in Dental Caries Experience

This study was aimed to investigated the relationship between caries experience and Zinc concentration in salivary supernatant. Materials and methods: This study was done on Forty healthy-looking dental students in Tikrit University, with age range between 19-24 years, stimulated mixed saliva were collected from them and the supernatant part of it were subjected to analysis by Atomic Spectrophotometer in analytical center of chemical engineering college/ Tikrit University, to estimate Zinc concentration. Assessment of caries prevalence was carried out by clinical examination using DMFT and DMFS indices. Zinc concentration and dental caries experience took place in relation to gender.The result showed that the Zinc level in saliva of caries experience group was 76.6±20.6 ng/ml, while that of caries free group was 72.6±32.3 ng/ml. The total mean of saliva Zinc concentration in saliva of males in both gr oups was higher than females.Saliva zinc concentrati on was higher in individuals with caries free when compared with individuals having caries experience. The severity of dental ca ries was associated with the increasing salivary zinc concentrat ion. There was significant differences between the salivary zinc concentration in both sexes. Males in both groups having higher salivary zinc concentration than that in females.

Changes in enzyme concentrations in mixed saliva during clinical manifestations of oral galvanosis

This article reviews the literature on the problem of the relationship between enzymes and changes in their concentrations in mixed saliva during clinical manifestations of galvanosis, as well as ways to determine their activity.

Novel portable photoelectrochemical sensor based on CdS/Au/TiO2 nanotube arrays for sensitive, non-invasive, and instantaneous uric acid detection in saliva

Uric acid (UA) monitoring is the most effective method for diagnosis and treatment of gout, hyperuricemia, hypertension, and other diseases. However, challenges remain regarding detection efficiency and rapid on-site detection. Here, we first synthesized a CdS/Au/TiO2-NTAs Z-scheme heterojunction material using a titanium dioxide nanotube array (TiO2-NTAs) as the substrate and modified with gold nanoparticles (Au) and cadmium sulfide particles (CdS). This material achieves bandgap alignment to generate a large number of electron-hole pairs under illumination. Then, using CdS/Au/TiO2-NTAs as the working electrode and molecularly imprinted polymers (MIP) as the recognition unit, we constructed a portable photoelectrochemical (PEC) sensor for non-invasive instant detection of UA concentration in human saliva, which has unique advantages in the field of high-sensitivity PEC instant detection. The portable MIP-PEC sensor achieves a linear range of 0.01–50 μM and a detection limit as low as 5.07 nM (S/N = 3). At the same time, the portable MIP-PEC sensor exhibits excellent sensitivity, specificity as well as stability, and shows no statistically significant difference compared to traditional high-performance liquid chromatography (HPLC) in practical sample detection. Compared to traditional PEC modes, this work demonstrates a novel and universal method for high-sensitivity instant detection in the field of PEC.

Green synthesized gold nanoparticles and CuO-based nonenzymatic sensor for saliva glucose monitoring.

Glucose, essential for brain and muscle functions, requires careful monitoring in diabetes and other chronic disease management. While blood glucose monitoring provides precise information about these diseases, it remains an invasive method. Saliva glucose monitoring could offer an alternative approach, but the glucose concentration in saliva is very low. In this work, we report a simple, low-cost, highly sensitive nonenzymatic electrochemical glucose sensor. We developed this sensor using green synthesized gold nanoparticles (AuNPs) and wet chemical synthesized copper oxide (CuO) nanoparticles on a screen-printed carbon electrode (Au/CuO/SPCE). The sensor's high sensitivity results from dual amplification strategies using AuNPs and CuO nanomaterials, each demonstrating catalytic activity towards glucose. This shows promising potential for saliva glucose monitoring. The AuNPs were synthesized using an Au precursor and orange peel extract (OPE), yielding stable colloidal AuNPs with a mean diameter of about 37 nm, thus eliminating the need for additional capping agents. Under optimal conditions, amperometric tests revealed that the sensor responded linearly to glucose concentrations ranging from 2 μM to 397 μM with a sensitivity of 236.70 μA mM-1 cm-2. Furthermore, the sensor demonstrated excellent reproducibility, stability and high selectivity for glucose in the presence of different biomolecules. We validated the sensor's efficacy by measuring glucose in human saliva, showing its potential for noninvasive glucose monitoring. This research advances the development of point-of-care devices, positioning the sensor as a promising tool for noninvasive glucose monitoring and improved diabetes management.

Multi-directional Changes in 8-OHdG Concentration in Saliva during HER2 Expression in Breast Cancer

The purpose of this work was to evaluate changes in the structure of 8-OHdG in saliva in patients with breast cancer depending on molecular biological subtypes. The findings show that decreased salivary 8-OHdG concentrations in the HER2-positive group rapidly correlated with decreased cell differentiation and high Ki-67 levels, reflecting the aggressive nature of the tumor disease and poor survival prognosis. Thus, the presence of high levels of 8-OHdG in the oral cavity may lead to the development of the role of a biological marker of the HER2-positive group with a poor prognosis of breast cancer and can be used as an additional method of diagnosis, patient condition and response to therapy.

Enhancing verapamil trace determination from biological matrices by bar adsorptive microextraction.

Verapamil is an L-type calcium channel blocker widely used in the treatment of cardiovascular diseases such as hypertension, angina and arrhythmias, requiring accurate therapeutic monitoring to maintain plasma, urine and saliva concentrations within a safe range. In this context, a novel analytical approach has been proposed to determine verapamil in biological samples, using bar adsorptive microextraction coated with reversed-phase polymers followed by high-performance liquid chromatography with diode array detection. Two adsorbents have been chosen, i.e. STRATA-CN and ENVI-18 polymers, showing recoveries from 56.01 ± 2.16% to 96.82 ± 0.61% under optimized experimental conditions, such as sample pH: 10.0 (STRATA-CN) and 8.0 (ENVI-18), 2 h of equilibrium time, stirring speed at 990 rpm, back-extraction solvent using methanol:acetonitrile (1 : 1 v/v), and 1 h under sonication. The analytical method showed linearity from 20 to 600 ng mL-1 (r ≥ 0.99), as well as adequate precision (with RSD% below 15%) and accuracy (with RE% within 15% of the nominal value). Finally, the analytical method was applied to plasma, urine and saliva samples and proved to be a promising alternative for the trace analysis of verapamil in biological matrices.

Lithium treatment for affective disorders: Exploring the potential of salivary therapeutic monitoring

Lithium is one of the most effective medications for treatment-resistant depression and bipolar disorder. However, lithium has a narrow therapeutic window: overdosing can lead to life-threatening lithium intoxication while underdosing results in a lack of desired therapeutic effects. Therefore, lithium treatment requires close monitoring with regular laboratory assessments of blood serum concentrations. An alternative method for monitoring lithium at home would increase the safety and empowerment of patients. In our project, we are investigating the potential of saliva as a readily accessible medium. We are exploring a) the best method for collecting and processing saliva, b) methods to measure salivary lithium levels, and c) the correlation between blood serum and saliva concentrations of lithium, and influencing factors; with the aim to develop a Point-of-care home testing device.

Санаторная реабилитация детей школьного возраста с постковидным астеническим синдромом

Aim. To study the effects of sanatory rehabilitation factors for the intensity of asthenic manifestations of post-COVID syndrome in school-aged children. Design. A non-randomized controlled study was conducted. Materials and methods. We examined 60 children aged 8 to 13 years old with asthenic manifestations of post-COVID syndrome; 20 healthy children were used as controls. Rehabilitation was organised at Svetlana health camp (a branch of the Territorial Clinical Hospital, Perm). All children shared their complaints and medical history as well as had their somatic and neurological status checked before and after rehabilitation. The degree of asthenia was determined using the Multidimensional Fatigue Scale; the functional status was evaluated using the functional status scale for post-COVID-19 patients; vegetative manifestations were recorded in a questionnaire and a pattern developed by A. M. Wein. Saliva levels of monocytic chemotactic protein-1 were determined with ELISA. Results. Children with past COVID-19 demonstrated a higher level of asthenia seen on the fatigue sub-scale — 81.22 [50.0; 100.0] points (р = 0.02 vs. controls), together with vegetative disorders; and saliva levels of monocytic chemotactic protein-1 (18.0 [12.5; 29.7] pg/mL) were higher than in controls (16.35 [11.00; 22.60] pg/mL; р = 0.012). After rehabilitation in a health camp, the intensity of asthenia decreased to 87.18 [75.0; 100.0] (р = 0.02), vegetative dysfunction improved, and functional status class changed from 1.74 [1.0; 3.0] to 0.77 [0; 1.0] (р = 0.02); saliva levels of monocytic chemotactic protein-1 increased to 23.1 [13.7; 43.7] pg/mL (p = 0.04). Quantitative changes are associated with improved clinical manifestations of post-COVID syndrome; therefore, elevated levels of this protein are a positive change. Conclusion. Post-COVID syndrome in school-aged children manifested with asthenic and vegetative disorders. Rehabilitation sanatory factors have favourable effect on the clinical manifestations of post-COVID syndrome, as well as the saliva concentration of monocytic chemotactic protein. Keywords: post-Covid syndrome, asthenia, children, monocyte chemotactic protein, rehabilitation.

Glyphosate and AMPA in saliva and other traditional human matrices. New findings for less invasive biomonitoring to the exposure to pesticides

Human biomonitoring of the exposure to pesticides is usually performed in biological matrices such as urine and plasma. However, the possibility of using less invasive matrices allows the screening of large number of subjects. The objective of this study was to evaluate the body burden of the exposure to the most widely used herbicide, Glyphosate (GLY), and its main metabolite, the aminomethylphosphonic acid (AMPA), in different populations from the province of Córdoba (Argentina), and to propose the saliva as a matrix for possible implementation in biomonitoring of the exposure to pesticides.Glyphosate and AMPA concentrations were evaluated in urine, plasma, and saliva of subjects occupationally and environmentally exposed to pesticides from one of the most important agricultural areas of Argentina. Gas chromatography coupled to tandem mass spectrometry (MS/MS) was used for the identification and quantification of the analytes.Both GLY and AMPA were quantified in all matrices with higher detection frequency (DF) in the occupationally exposed group than in non-occupationally exposed individuals. Among evaluated matrices, the highest DF and concentration levels of GLY were found in saliva. Moreover, the only statistical difference between groups of subjects were found for GLY and AMPA concentrations in saliva, indicating the possible use of this non-invasive human matrix to evaluate different levels and scenarios of exposure. No significant correlation was found between GLY and AMPA levels in saliva and the traditional matrices (urine and blood) used to measure exposure to pesticides.This is the first report of the presence and concentrations of GLY and AMPA in human saliva samples. Results of the present study are relevant for future biomonitoring of the exposure to GLY, but also to pesticides in general. Saliva deserved further investigation as an alternative, easy, and economical matrix involving less invasive methods for biomonitoring and screenings of large populations.

Dose-response relationship between toothpaste soluble fluoride absorbed in the gastrointestinal tract and saliva fluoride secretion

Aim: This study aimed to evaluate if there is a dose-response relationship between toothpaste chemically soluble fluoride absorbed in the gastrointestinal tract and fluoride secreted by saliva, giving support to the use of saliva as surrogate for plasma fluoride. Methods: A 4-phase single blind study was conducted, in which 10 participants were subjected in each phase to one of the assigned treatment groups: group I: fresh sample of a Na2FPO3/CaCO3-based toothpaste with 1,334 μg F/g of total soluble fluoride (TSF) and groups II–IV: aged samples of this toothpaste presenting TSF concentrations of 1,128, 808, and 687 μg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 μg F/Kg body weight, as total fluoride (TF). Saliva and blood samples were collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. F concentration in saliva and blood plasma was determined with a fluoride ion-specific electrode. The areas under the curve (AUC) of F concentration versus time (AUC = ng F/mL × min) and the peaks of fluoride concentration (Cmax) in saliva and plasma were calculated. Results: A significant correlation between mg of TSF ingested and the AUC (r=0.47; p&lt;0.01), and Cmax (r=0.59; p&lt;0.01) in saliva was found; for TF, the correlation was not significant (p&gt;0.05). In addition, the correlations between plasma and saliva fluoride concentrations were statistically significant for AUC (r=0.55; p&lt;0.01) as for Cmax (r=0.68; p&lt;0.01). Conclusion: The findings support that saliva can be used as a systemic biomarker of bioavailable fluoride present in Na2FPO3/ CaCO3-based toothpaste.

Claudin-10 Decrease in the Submandibular Gland Contributes to Xerostomia

Tight junction proteins play a crucial role in paracellular transport in salivary gland epithelia. It is clear that severe xerostomia in patients with HELIX syndrome is caused by mutations in the claudin-10 gene. However, little is known about the expression pattern and role of claudin-10 in saliva secretion in physical and disease conditions. In the present study, we found that only claudin-10b transcript was expressed in human and mouse submandibular gland (SMG) tissues, and claudin-10 protein was dominantly distributed at the apicolateral membranes of acini in human, rat, and mouse SMGs. Overexpression of claudin-10 significantly reduced transepithelial electrical resistance and increased paracellular transport of dextran and Na+ in SMG-C6 cells. In C57BL/6 mice, pilocarpine stimulation promoted secretion and cation concentration in saliva in a dose-dependent increase. Assembly of claudin-10 to the most apicolateral portions in acini of SMGs was observed in the lower pilocarpine (1 mg/kg)–treated group, and this phenomenon was much obvious in the higher pilocarpine (10 mg/kg)–treated group. Furthermore, 7-, 14-, and 21-wk-old nonobese diabetic (NOD) and BALB/c mice were used to mimic the progression of hyposalivation in Sjögren syndrome. Intensity of claudin-10 protein was obviously lower in SMGs of 14- and 21-wk-old NOD mice compared with that of age-matched BALB/c mice. In the cultured mouse SMG tissues, interferon-γ (IFN-γ) downregulated claudin-10 expression. In claudin-10–overexpressed SMG-C6 cells, paracellular permeability was decreased. Furthermore, IFN-γ stimulation increased p-STAT1 level, whereas pretreatment with JAK/STAT1 antagonist significantly alleviated the IFN-γ–induced claudin-10 downregulation. These results indicate that claudin-10 functions as a pore-forming component in acinar epithelia of SMGs, assembly of claudin-10 is required for saliva secretion, and downregulation of claudin-10 induces hyposecretion. These findings may provide new clues to novel therapeutic targets on hyposalivation.