Saliva Concentrations Research Articles

Comparison of Salivary Opiorphin in Burning Mouth Syndrome and Healthy Subjects and Its Correlation With Psychiatric Disorders

ABSTRACTObjectivesBurning mouth syndrome (BMS) is a chronic disease in which the patient experiences a burning sensation in the oral mucosa without any pathological cause. Opiorphin is a pentapeptide that prevents pain and can have an antidepressant effect. The aim of this study was to evaluate salivary opiorphin concentration in BMS and healthy subjects. In addition, opiorphin concentration in BMS patients before and after psychiatric treatment was compared and the association between burning severity and psychiatric scores with salivary opiorphin concentration was examined.Materials and MethodsThis cross‐sectional study included 28 BMS patients and 40 healthy individuals referred to the Department of Oral and Maxillofacial Medicine, Faculty of Dentistry, Mashhad, from September 2018 to August 2019. Patients with proven disease based on clinical and psychiatric examinations were included in the study. Unstimulated salivary opiorphin levels were assessed by ELISA. Statistical analysis was performed using SPSS version 24.ResultsSalivary opiorphin levels were significantly higher in BMS patients (2.16 ± 0.30 ng/mL) than in healthy subjects (1.80 ± 0.36 ng/mL) (p < 0.001). Opiorphin levels in BMS patients increased insignificantly after psychiatric therapy (p = 0.212). In addition, there was no significant association between opiorphin levels and age, gender, menopause, burning severity, anxiety, and depression status.ConclusionsThe opiorphin concentration in saliva is higher in BMS patients than in healthy subjects. Most BMS patients also suffer from anxiety and depression.

Metal ions released during canine retraction using fixed orthodontic appliance: Prospective clinical study

Background: Metal ions released from dental alloys pose a significant concern due to their potential local and systemic effects. One of these effects is hypersensitivity, particularly associated with nickel-containing dental alloys. Aims: to measure metal ion concen-tration in saliva during orthodontic space closure on a 0.019X0.025 working archwire. Material and Methods: Trial design: Con-trolled clinical trial. Setting: Orthodontic treatment was provided at the Postgraduate Orthodontic Teaching Clinics and saliva testing was performed at the Faculty of Chemical Engineering/ Jordan University of Science and Technology (JUST). Methods Participants and interventions: Twenty-eight participants with bimaxillary proclination requiring extraction of all first premolar teeth participated in this study. Teeth alignment started with 0.014-inch nickel titanium (NiTi) archwire, then with a sequence of 0.018-inch, 0.016X0.022-inch, and 0.019X0.025-inch NiTi archwires, before 0.019X0.025-inch Stainless Steel (SS) rectangular archwire was reached. Patients were monitored monthly for a period of three months. Three unstimulated saliva samples were collected from each patient; before the commencement of treatment (T0), when 0.019X0.25-inch SS archwire was reached before space closure (T1), and one month after space closure (T2). Ion concentration in saliva samples was measured using an inductively coupled plasma mass spectrometer (ICP-MS). Results: Before treatment, iron concentration (53 Fe and 54 Fe) averaged 197.05 (64.35) mg/L and 425.48 (164.43) mg/L, respectively. Iron concentration increased during the alignment stage of orthodontic treatment (P<0.05) with no sig-nificant increase during space closure (P>0.05). Other investigated ions (Cr, Co, Ni, and Ti) did not show significant changes during orthodontic treatment (P>0.05). Conclusions: There was no increase in the metal ions concentration (Fe, Cr, Ti, and Ni) during space closure using a 0.019X0.025 working archwire and the Fe ion concentration increased in the initial stages of orthodontic treatment

Salivary Chromium and Cobalt Concentrations in Patients with Dental Metallic Restorations-A Pilot Study.

Introduction: Metal ions, released from dental alloys due to corrosion, come in contact with the cells of the surrounding tissues and may spread throughout the body via the gastrointestinal system, thus inducing dose-dependent cytopathological effects. This study aimed to assess and compare the salivary cobalt and chromium concentrations in individuals aged 18-65 years with and without dental restorations containing metal alloys. Methods: Participants were divided into two main groups according to the existence of metal alloys in the oral cavity-18 patients had fixed prosthetic restorations made of metal alloys, and 17 patients had no metal objects in their oral cavity. Each main group was subdivided into two subgroups according to the type of saliva sample-with or without additional stimulation. Salivary cobalt and chromium concentrations were measured by inductively coupled plasma mass spectrometry. A non-parametric Mann-Whitney test and Spearman's rank correlation coefficient were applied, and the level of significance was set to p < 0.05. Results: The results showed that the chromium level in non-stimulated saliva was higher in the group of patients with metal dental restorations. No statistical difference was found in cobalt levels. There was no statistical difference in Co or Cr concentrations in stimulated saliva between the studied groups. A positive correlation was found between Cr and Co concentrations in non-stimulated saliva and between cobalt concentrations in stimulated and non-stimulated saliva. Conclusions: Metal alloys in the oral cavity induced elevated chromium levels in non-stimulated saliva, and a correlation between chromium and cobalt ion concentration was found. A detailed examination of patients and their medical history prior to prosthetic treatment is advisable in order to avoid any undesired health effects.

The effect of 12-week high-dose Colostrum Bovinum supplementation on immunological, hematological and biochemical markers in endurance athletes: a randomized crossover placebo-controlled study.

Bovine colostrum (COL) is assumed to be one of the strongest natural immune stimulants. Regular ingestion of COL may contribute to improved immune response in athletes exposed to high training loads. Twenty-eight endurance-trained males aged 31.1 ± 10.2 years (body mass 81.9 ± 9.0kg; height 1.82 ± 0.06m) completed this randomized double-blind placebo(PLA)-controlled crossover study aimed at investigating the effect of 12-week COL supplementation (25gCOL·day-1) on resting (REST), exercise-induced (POST-EX), and short-term post-exercise recovery (REC; 1h after test exercise) changes in selected saliva and blood immunoglobulins (Ig), white blood cell (WBC) count and differential; as well as blood hematological, nutritional status and muscle damage indices. The protocol assumed 4 study visits - before/after supplementation with COL (COLPRE and COLPOST ) and PLA (PLAPRE and PLAPOST ). During testing sessions, incremental rowing test to exhaustion and swimming-specific performance test were introduced as exercise stimuli. At COLPOST visit the secretory IgA (SIgA) concentration in saliva was significantly higher at POST-EX and REC compared to REST (p<0.05). COL supplementation had no effect on blood IgA, IgE, IgD, IgG, and IgM concentrations. Furthermore, after COL supplementation decrease of hematocrit at REC (p<0.05) was revealed. 12-week supplementation with 25 gCOL·day-1 in endurance-trained male athletes resulted in a favorable increase in post-exercise concentration of salivary SIgA. COL seems to be a potential stimulator of local immune defense after exercise-induced homeostasis disturbances. Nevertheless, the lack of effect on blood markers indicates the need for further research in the area of mechanisms underlying the effect of the supposed COL immunological capacity.

Clinical research for saliva-based therapeutic drug monitoring of linezolid.

Linezolid is primarily used to treat of methicillin-resistant Staphylococcus aureus and multidrug-resistant tuberculosis infections. Thrombocytopenia due to linezolid usage is a concern, and therapeutic drug monitoring has been reported to be effective in its prevention. Plasma concentrations provide valuable information for treatment decisions; however, collecting plasma samples can be burdensome for both patients and healthcare providers. Therefore, there is interest in saliva as an alternative for monitoring, considering its potential to replace plasma samples. Patients hospitalized at Hokkaido University Hospital and Hokkaido Spinal Cord Injury Center between April 2022 and July 2024, who received oral or intravenous linezolid treatment, were enrolled. The concentrations of linezolid were simultaneously measured in plasma and saliva samples. We determined the concentration profiles of linezolid in the saliva and examined the correlation between saliva and plasma linezolid concentrations. Eighteen patients receiving linezolid were enrolled. The average of saliva/plasma (S/P) concentration ratios of linezolid were 1.018. A strong correlation was found between the salivary and plasma concentrations of linezolid (R= .833, P< .001). Notably, in patients receiving intravenous administration of linezolid, the correlation was even more pronounced (R= .885, P< .001). Additionally, when focusing on the S/P ratio of the trough concentrations in the morning and at night, the S/P ratios at night were much closer to 1.0. The concentrations of linezolid in plasma and saliva were similar, indicating their potential applicability in clinical settings. The monitoring of linezolid concentrations in saliva has been shown to be particularly suitable for patients receiving intravenous administration.

A sensitive immunoassay for the quantitation of Pig-MAP in pig saliva samples

The purpose of the study is to develop a sensitive assay for the proper quantification of the acute phase protein Pig-MAP in pig saliva samples. A time-resolved immunofluorometric assay (TR-IFMA) was developed using two pig-MAP-specific monoclonal antibodies. The limit of detection of the assay was 4 ng/mL, enough to measure pig-MAP concentration in saliva. Precision was evaluated for saliva samples of low, medium and high concentration, with inter assay CV of 4–14 % and inter-assay CV of 8–20 %. The assay kept linearity under dilution and a method comparison study performed with serum samples showed good correlation with ELISA. Median Pig-MAP concentration in saliva from healthy animals was 19 ng/mL whereas in pigs with different inflammatory conditions was 11 times higher. In the same animals median pig-MAP serum concentrations were 0.72 mg/mL in the healthy group and 4.61 in the diseased group. The Spearman coefficient of correlation between Pig-MAP concentration in serum and saliva was of 0.72. A correlation was also observed between the salivary concentration of pig-MAP and other two acute phase proteins such as haptoglobin (r = 0.62) or C-reactive protein (r = 0.65). The concentration of Pig-MAP in saliva of pigs with severe respiratory disease decreased significantly from a median value of 128 ng/mL at the time of disease detection to 8 ng/mL after 1 day of antibiotic therapy. Studies performed show that pig-MAP is present in saliva and this specimen may be an alternative to serum for pig-MAP quantification.

8665 Female Fertility In Patients With Classic And Non-Classic Congenital Adrenal Hyperplasia Under Modified-Release Hydrocortisone (MR-HC)

Abstract Disclosure: L. Tschaidse: None. H.F. Nowotny: None. M. Auer: None. C. Lottspeich: None. M. Bidlingmaier: None. J. Hawley: None. B.G. Keevil: None. N. Reisch: None. Background: Female patients with classic and non-classic (NC) CAH struggle with fertility, due to androgen excess, elevated progesterone and 17-hydroxyprogesterone (17OHP) levels, causing anovulation, impairment of endometrial development and menstrual irregularities. The typical approach to treating infertility often includes an increase in glucocorticoid (GC) dose. However, this poses a potential risk of side effects. Limited observational data on modified-release hydrocortisone (MR-HC), which better mimics the physiological diurnal rhythm of cortisol secretion, indicates improved fertility in female and male patients with classic CAH. Therefore, the aim of this study was to investigate fertility in women with classic and non-classic CAH before and after switching to MR-HC. Methods: 21 adult female patients with CAH (14 classic; 5 NC) with a median (range) age of 33.0 (30.0) years, premenopausal and without hormonal contraception, were enrolled in this prospective, observational, single-centre study. The data collection took place before (conventional GC preparation) and after dose-equivalent switching the medication to MR-HC. In addition to clinical parameters such as menstrual cycle and desire to conceive, the collection of morning serum and daily saliva profiles was conducted, measuring progesterone, 17OHP, androstenedione (A4), testosterone, 11-ketotestosterone (11KT) as well as 11-hydroxyandrostenedione (11OHA4). Results: Before study inclusion, 4/21 patients had an irregular cycle, 5/21 were amenorrhoeic and 10/21 patients had a desire to have children. There was no difference in median (range) hydrocortisone dose equivalent before and after switching to MR-HC (25.0 (50.0) vs. 25.0 (30.0), p=.441). Median (range) morning serum concentrations between 8-10 am were not different before and after switch to MR-HC for progesterone (5.9 (55.5) vs. 5.0 (58.8), p=.823), 17OHP (5.9 (362.1) vs. 5.7 (73.7), p=.280), A4 (2.9 (25.6) vs. 2.5 (6.9), p=.106), testosterone (0.8 (3.5) vs. 0.7 (1.5), p=.063), 11KT (0.4 (7.4) vs. 0.2 (2.6), p=.242) and 11OHA4 (0.8 (12.9) vs. 0.9 (10.4), p=.231). Concerning saliva day profiles, we found a significantly lower median (range) 17OHP level in early morning saliva (43.0 (526.9) vs. 19.4 (264.3), p=.049). 5/9 patients with menstrual irregularities reported menstrual regularisation within and 5/10 patients with a desire to have children became pregnant after switching to MR-HC. Conclusion: Our preliminary data show clinical improvement in fecundity and fertility under MR-HC in both women with classic and NC CAH without a dose increase of glucocorticoids. Under MR-HC replacement lower 17OHP concentrations in early morning saliva reflect better hormonal control over night contributing to ovulatory cycle regulation and improved fertility. Presentation: 6/1/2024

8169 Bilateral Inferior Petrosal Sinus Sampling Using Metyrapone as a Reliable Alternative to Differentiate Between Cushing Disease and Ectopic ACTH Syndrome- A Single Center Experience

Abstract Disclosure: M. Azmath: None. S. Faisal: None. C. Caetano: None. T. Vedere: None. H. Aftab: None. B. Tendler: None. C. Malchoff: None. Introduction: Bilateral IPSS is a crucial test in accurately diagnosing Cushing disease (CD) and differentiating it from ectopic ACTH syndrome (EAS). [1] CRH stimulated IPSS is the gold standard technique but cannot be performed due to current shortage of CRH. Metyrapone is a safe and reliable alternative to CRH that can stimulate corticotrophs to secrete ACTH and hence used for IPSS. [2] We would like to share a single center experience using a novel low dose metyrapone protocol for IPSS that successfully helped differentiate CD and EAS. Methods: This was a retrospective analysis of patients presenting with Cushing syndrome. Initial diagnosis was confirmed based on standard testing including 24-hour urinary free cortisol (UFC), late night saliva concentrations (LNSC) and MRI. Metyrapone 500 mg every 4 hours for 3 doses was administered orally starting midnight prior to IPSS performed in the morning. ACTH levels drawn during initial evaluation for Cushing syndrome was compared to ACTH values post metyrapone from the peripheral vein sample to calculate a gradient. Ultimately, pituitary CD or EAS was confirmed based on cure following surgery and /or positive ACTH of tumor staining on pathology and/or concordant results with CRH stimulated IPSS. Results: There were 9 patients, out of which 5 had pituitary CD, and 4 had EAS. Pre ACTH levels for patients ranged between 14.5 and1164 pg/ml (normal reference range 6-50). Following metyrapone, ACTH level rose to 40-4705 pg/ml (normal reference range 6-50). The increase in ACTH levels ranged from 81-547% pre and post metyrapone. An average of 5-6 ACTH samples were drawn during IPSS. Catheterization was successful in all patients and was confirmed by IR. The mean central to peripheral (C/P) ACTH ratio for patients with confirmed CD was 20.53 in comparison with a ratio of 1.34 in patients with EAS. IPSS was confirmed to be diagnostic for pituitary CD if the peak ratio after metyrapone administration was more than 3. No adverse effects were observed during or after the procedure and no hospitalization was required pre-procedure. Discussion: We present single center experience with a novel low dose metyrapone protocol for IPSS. Our protocol was successful in increasing ACTH/cortisol secretion by tumorous cells as evidenced by increase in ACTH levels post metyrapone. It is an easy oral protocol which proved to be safe without the risk for adrenal insufficiency that can occur with higher doses. It also mitigates the small thromboembolic risk that can occur with DDAVP administration. A clear distinction in C/P ACTH ratios was observed in patients with CD versus EAS as early as the 3rd sample. In conclusion, our low dose metyrapone protocol was safe and reliable in accurately differentiating between CD and EAS in small sample of patients at our institution. Presentation: 6/1/2024

Physiological regulation of oral saliva ion composition and flow rate are not coupled in healthy humans-Partial revision of our current knowledge required.

Appropriate composition of oral saliva is essential for a healthy milieu that protects mucosa and teeth. Only few studies, with small sample numbers, investigated physiological saliva ion composition in humans. We determined saliva ion composition in a sufficiently large cohort of healthy adults and analyzed the effect of physiological stimulation. We collected saliva from 102 adults under non-stimulated and physiologically stimulated conditions (chewing). Individual flow rates, pH, osmolality, Na+, K+, Cl-, and HCO3- concentrations under both conditions as well as the individual changes due to stimulation (Δvalues) were determined. Non-stimulated saliva was hypoosmolal and acidic. Na+, Cl-, and HCO3- concentrations remained well below physiological plasma values, whereas K+ concentrations exceeded plasma values more than twofold. Stimulation resulted in a doubling of flow rates and substantial increases in pH, HCO3-, and Na+ concentrations. Overall, stimulation did not considerably affect osmolality nor K+ or Cl- concentrations of saliva. An in-depth analysis of stimulation effects, using individual Δvalues, showed no correlation of Δflow rate with Δion concentrations, indicating independent regulation of acinar volume and ductal ion transport. Stimulation-induced Δ[Na+] correlated with Δ[HCO3-] and Δ[Cl-] but not with Δ[K+], indicating common regulation of ductal Na+, Cl-, and HCO3- transport. We present a robust data set of human oral saliva ion composition in healthy adults and functional insights into physiological stimulation. Our data show (i) that flow-dependence exists for Na+ and HCO3- but not for K+ and Cl- concentrations, (ii) osmolality is flow-independent, (iii) regulation of Na+, Cl-, and HCO3- transport is coupled, (iv) regulation of flow rate and ion concentrations are independent and (v) spatially separated between acini and ducts, respectively.

Effect of a plant extract of fenugreek (Trigonella foenum-graecum) on testosterone in blood plasma and saliva in a double blind randomized controlled intervention study.

Many aging men experience reduced energy and libido related to non-optimal testosterone levels. We conducted a randomized double-blind trial with TrigozimR fenugreek extract to assess impact on plasma and saliva testosterone, and some subjective effects. 95 men (40-80y) completed a 12-week intervention, taking 3 tablets daily with 0 mg (placebo; n = 22), 600 mg (n = 21), 1200 mg (n = 25) and1800 mg (n = 27) fenugreek extract and essential nutrients. Samples were collected at weeks 0, 2, 6, and 12. Participants answered a pre- and post-intervention questionnaire on lifestyle and libido. We measured total testosterone (HPLC-MS/MS) and sex hormone binding globulin (ELISA), calculated free testosterone index (FTI), and measured saliva testosterone. Plasma total testosterone and FTI increased after any dose of TrigozimR vs. baseline (13.0%, p = 1.0x10-4 and 16.3%, p = 6.2x10-6), but not vs. placebo (9.0%, p = 0.122 and 11.3% p = 0.059). 1800 mg TrigozimR resulted in 12.2% increased FTI (p = 0.025). Saliva testosterone concentration increased after any dose of TrigozimR vs. baseline (31.1%, p = 2.3x10-4) and vs. placebo (37.2%, p = 0.042). 1800 mg TrigozimR for 12 weeks resulted in 19.6% (p = 0.006) increased saliva testosterone. Compliance was confirmed by enhanced plasma concentration of 25-hydroxy vitamin D3. We observed no subjective effects or side-effects of TrigozimR. TrigozimR increased saliva and plasma testosterone concentration during intervention but only for saliva vs. placebo. Saliva may be preferred for measuring free testosterone due to no protein-bound testosterone.

225 Kidney function and nitrogen excretion in Brown Swiss and Holstein dairy cows

Abstract The agricultural sector contributes to nitrogen (N) emissions since farm animals excrete considerable N amounts via feces and urine. To reduce N emissions by dairy cattle, methods predicting accurately individual N emissions are of great interest. Recent data showed that Brown Swiss (BS) cows have greater urea concentrations in milk and blood than Holstein (HO) cows. However, it is still unknown if greater BUN concentrations in a particular breed are congruently reflected by concomitantly increased contents of nitrogenous compounds in other media (e.g., urine and saliva). Thus, the present study simultaneously assessed biomarkers for kidney function like urea, and creatinine and symmetric dimethylarginine (SDMA) concentrations in several body fluids (i.e., blood, urine, milk, and saliva) as well as nitrogen excretion in feces in BS and HO cows under identical feeding conditions. Blood, saliva, urine, and feces were sampled in 31 multiparous BS and 46 HO cows kept under identical feeding and management conditions. Samples were collected at different lactational stages after the monthly DHIA control test-day. Concentrations of urea and creatinine were measured in serum, urine, and saliva. Symmetric dimethylarginine was determined in serum, which is an established indicator for glomerular filtration rate (GFR). Feces were analyzed for dry matter content and nitrogen concentrations. Data on milk urea and protein concentrations, and daily milk yield were obtained from the monthly DHIA test-day records. The effects of breed, time, and parity number on blood, saliva, urine, feces, and milk parameters were evaluated with the GLM procedure with breed, time, and parity number as fixed effects. Differences between BS and HO were assessed by the Tukey-corrected t-test at P &amp;lt; 0.05. Dry matter intake and body weight were similar in BS and HO cows (P &amp;gt; 0.05). No differences between BS and HO were observed for milk yield, fecal DM and nitrogen content. BS cows showed greater urea concentration (25.8 ± 0.7 vs 21.8 ± 0.7 mg/dL), and protein content in milk (3.70 ± 0.08 vs 3.45 ± 0.07%) than HO cows (P &amp;lt; 0.01). Concentrations of urea, creatinine, and SDMA in serum, were greater in BS than in HO cows (P &amp;lt; 0.01) with 5.46 ± 0.19 vs 4.72 ± 0.13 mmol/L for urea, 105.96 ± 2.23 vs 93.07 ± 1.50 mmol/l creatinine, and 16.78 ± 0.69 vs 13.39 ± 0.44 µg/dL SDMA, respectively. Urea and creatinine concentrations in urine and saliva did not differ among breeds. Despite greater urea and creatinine concentrations in blood, and milk urea content in BS compared with HO, excretion of these parameters did not differ between breeds in urine. Our results suggest a reduced renal glomerular filtration rate in BS compared with HO. The underlying mechanisms require further investigations.

90 Awardee Talk: Shedding light into the black box: The dual-flow continuous culture system and ruminal fermentation

Abstract Nutrients derived from ruminal fermentation supply a substantial amount of metabolizable nutrients for ruminants. These include amino acids, carbohydrates, fatty acids, vitamins, and fermentation end products, such as ammonia and volatile fatty acids. Furthermore, ruminal fermentation modifies dietary nutrients in such a way that nutrients reaching the small intestine for absorption may substantially differ from those being consumed in the diet. Therefore, understanding ruminal fermentation kinetics and quantification of nutrients flowing out of the rumen is an important aspect of ruminant nutrition. Accurate quantification of these nutrients, using in vivo experiments, is laborious, costly, and invasive, requiring surgical procedures such as ruminal, abomasal, and intestinal cannulas. To decrease the time and cost of experiments as well as the use of animals, in vitro methodologies are important tools in ruminant nutrition. Therefore, the objectives of this presentation are i) describe different in vitro methodologies, ii) discuss the advantages of in vitro methodologies, iii) discuss shortcomings of in vitro methodologies, and iv) describe potential developments that may improve in vitro methodologies. Having been used for decades, in vitro methodologies such as pure, batch, and continuous cultures have been well documented to investigate a wide array of aspects of nutrition, including the effects of different dietary compositions, individual fermentation end products, and impacts on the microbiome. However, both batch and pure cultures can result in a build-up of end products that may inhibit fermentation. Continuous culture, however, allows for the removal of end products but, similar to pure and batch cultures, is applicable only to ruminal fermentation and cannot provide information regarding intestinal digestion. The dual-flow continuous culture system (DFCC), developed in the 1970s and used by various laboratories in the USA and Europe consists of fermentation vessels of approximately 1.5 L that are capable of simulating ruminal fermentation for periods longer than 10 d. It has been extensively used and evaluated by meta-analyses. When compared with other in vitro methodologies, the DFCC has longer fermentation time, larger volume, and the possibility of sampling from the liquid and the solid flows. When compared with in vivo experiments the DFCC is faster, less costly, less invasive, allows for greater range of treatments, allows for more controlled condition, and isolates ruminal function. Limitations of the DFCC include it does not predict in vivo response, it assumes equal saliva flow and concentration, no effects of intake, no ruminal absorption, less retention of protozoa, possible differences in microbiome, and limited gas emission data. Therefore, while in vitro methodologies provide useful data into the field of ruminant nutrition, some in vitro methodologies are more robust than others. Furthermore, in vivo experiments are still the ideal approach for assessing nutrient utilization and necessary to evaluate animal responses.

STUDYING INDICATORS OF CIRCADIAN RHYTHMS OF MACROELEMENTS CONCENTRATION IN HUMAN SALIVA UNDER NORMAL CONDITIONS

Seasonal and circadian research in the field of chronobiology and chronomedicine is currently of particular interest to scientists. Chronobiology has discovered previously unknown approaches to the diagnosis, treatment and prevention of diseases. For biological objects, as an open thermodynamic system, in their development have absorbed all the laws of the rhythmically oscillating external world and interact with it with the help of these vibrations. Therefore, at the present stage of the development of chronobiology, any research that fills, like bricks, still empty niches of new knowledge reflects the advanced frontiers of natural science and is included in the creation of a future general theory of biology. This is confirmed by a number of discoveries of scientists in the field of physics, physiology and medicine. Thus, a group of scientists became laureates of the Nobel Prize in physics in 2017 for the discovery of gravitational waves, and in the field of physiology and medicine, a number of scientists (Hall, Rosbash, Young) became Nobel laureates for a series of works on the topic: "Studying the mechanisms of the circadian dynamics of the body." Today, chronobiology can characterize periodic fluctuations of, perhaps, all organs, all body systems. A large amount of data has been accumulated on the daily and seasonal rhythms of the digestive and urinary tract organs, respiratory and cardiovascular systems, brain, etc. A violation of biorhythms can lead to the development of defects in oral and maxillofacial tissues, the development of inflammation and tumors, which affects cell proliferation, apoptosis, oxidative stress, etc. The main purpose of this work was to study the characteristics of circadian rhythms of macroelement concentrations in human saliva under normal conditions. A feature of the research work is the determination of the concentration of macroelements in saliva in the summer. The saliva of 12 healthy volunteers was taken as the study material. Age 22-30 years. The method of spectrophotometry was used in this research work. The research work was carried out in the summer at the Department of Biophysics, Biomedicine and Neuroscience of the al-Farabi Kazakh National University and at the City Clinical Hospital №1 in Almaty. During the study, a saliva sample was collected on 1.5 ml of Eppendorf. All samples were stored in the freezer. Before the experiment, the material was soaked at room temperature for 30-40 minutes. Using the spectrophotometric method, we determined the concentration of macroelements in saliva using a set of special reagents. We have identified the features of the daily dynamics of the concentration of macroelements in the saliva of healthy people in summer: K, Na, Ca, Mg and P. The concentration of macroelements varied widely throughout the day. As a result of the study, the concentration index of K during the day normally ranges from 528±36 µg/ml to 634±42 µg/ml; Na - from 153.4±19.8 µg/ml to 144.9±25.1 µg/ml; Ca-from 35.4±4.0 µg/ml to 45.5±5.1 µg/ml; Mg-from 2.12±0.15 µg/ml to 4.02±0.25 µg/ml and P-from 134.5±7.7 µg/ml to 151.6±10.1 µg/ml. Summing up, we have identified the features of the daily dynamics of the concentration of macroelements in the saliva of healthy people in summer. In summer, the daily dynamics of the concentration of macroelements in saliva ranged from 2.12±0.15 µg/ml (Mg) to 634±12 µg/ml (K).

Kinetics of fluoride after brushing with the no-rinse method

BackgroundFluoride plays a vital role in preventing dental caries, with its addition to oral care products significantly promoting oral hygiene. A no-rinse brushing method aims to increase fluoride retention in the oral cavity, as rinsing with water decreases fluoride levels in saliva, which could affect remineralization. While the no-rinse brushing method holds promise for improving fluoride retention in the oral cavity, critical inquiries persist regarding its safety. This study investigated the kinetics of oral fluoride and potential risks to fully assess its effectiveness and implications for oral health.MethodsTen healthy adults participated in a crossover study comparing the no-rinse with the rinse method. All subjects followed American Dental Association (ADA) brushing guidelines. Levels of fluoride in saliva (supernatant and sediment) and urine were measured over time, and plasma fluoride was measured one hour after brushing. Pharmacokinetic parameters were also calculated from the data.ResultsParticipants using the no-rinse method had higher fluoride levels in supernatant immediately and up to 30 min post-brushing compared to the rinse method. Fluoride levels in sediment were higher only immediately after brushing. The total fluoride concentration in saliva remained elevated for up to 5 min with the no-rinse method. Systemic fluoride absorption showed no significant difference between the two methods based on blood and urine analysis.ConclusionThis research indicates that the no-rinse method can enhance fluoride retention in the oral cavity for up to 30 min after a single brushing. In addition, our findings suggest that this method does not significantly influence systemic fluoride levels or toxicity.RegistryThai Clinical Trials Registry, TCTR (http://thaiclinicaltrials.org). Clinical trial registration number: TCTR20231104001 (4/11/2023).

Salivary Interleukin-13 and Transforming Growth Factor Beta as Potential Biomarkers of Cancer Cachexia.

serum and saliva specimens were obtained from 78 patients. Forty-six patients were non-cachectic, and 32 patients were cachectic (per SCRINIO group criteria), all with metastatic solid tumors. Commercial ELISA kits were used to determine the salivary and serum concentrations of interleukin 13 (IL-13) and transforming growth factor beta (TGF-β) in two patient groups and healthy controls. Laboratory values were obtained from the hospital information system, and weight and height were measured at the time of sampling. A statistically significant difference was observed between the groups in saliva IL-13 concentrations but no difference in serum concentrations. Statistically significant differences were also observed between the groups in saliva and serum concentrations of TGF-β. Logistic regression analysis has identified salivary IL-13 and TGF-β as independent factors for cancer cachexia. We demonstrated saliva as a valuable specimen for cachexia investigation and established IL-13 and TGF-β as potential cancer cachexia biomarkers. Further research is needed to evaluate these findings.

Cortisone in saliva of pigs: validation of a new assay and changes after thermal stress

BackgroundCortisone is derived from cortisol through the action of the enzyme 11β-hydroxysteroid dehydrogenase type II, and it has gained importance in recent years as a biomarker of stress. This study aimed to develop and validate an assay for the measurement of cortisone in pig saliva and evaluate whether its concentration varies in stressful situations. For this purpose, a specific immunoassay was developed and validated analytically, and a study was performed to evaluate whether cortisone concentrations in saliva can vary under heat stress conditions.ResultsThe assay proved to be accurate, reliable, and sensitive for the measurement of cortisone in pig saliva. The limit of detection of the assay was set at 0.006 ng/ml, and the lower limit of quantification was 0.023 ng/ml. It also correlated significantly with the results obtained by LC‒MS/MS (P = 0.003; r = 0.64). In addition, the cortisone concentration in animals subjected to prolonged heat stress decreased significantly 15 days after treatment (P < 0.0001).ConclusionsAccording to these results, cortisone measured by this assay could be used as a tool for the non-invasive evaluation of thermal stress in pig saliva.

Intrinsic oxidase-mimicking activity of nitrite upon visible light illumination and its colorimetric detection in saliva

Small molecules with enzyme-like properties have recently attracted considerable attention. Herein, we discovered that nitrite possesses intrinsic oxidase-mimicking activity upon visible light, catalyzing the oxidation of the typical chromogenic substrate in the absence of H2O2. Notably, nitrite exhibited a markedly high value of Kcat, approximately 4, 7, and 4000-fold greater than that of Acr+-Mes, Eosin Y, and Diacetyl, respectively. Comprehensive investigation elucidated that O2•⁻ and •OH are the primary reactive oxygen species (ROS) responsible for the oxidation of 3,3′,5,5′-tetramethylbenzidine dihydrochloride hydrate (TMB). Leveraging the linear correlation between the absorbance of oxidized TMB (oxTMB) at 652 nm and nitrite concentration, a simple colorimetric approach for nitrite detection was successfully established in the range of 1–75 μM with a detection limit of 0.14 μM. Moreover, the proposed strategy could be applied to determine the nitrite concentration in saliva, exhibiting a great prospect for clinical diagnosis. This work contributes novel insights into the exploration of small-molecule enzyme mimics.

Oxytocin and cortisol concentrations in urine and saliva in response to physical exercise in humans

BackgroundWhile peripheral markers of endogenous oxytocin and glucocorticoid release are widely employed in psychological and behavioural research, there remains uncertainty regarding the effectiveness of saliva and urine samples in accurately capturing fluctuating hormone levels in response to relevant stimuli. In addition, it is unclear whether and under which conditions, urinary concentrations correlate with salivary levels of oxytocin and cortisol. MethodsIn the present study, two groups of healthy adult male and female participants (N=43) provided heart rate, saliva, and urine samples before and after exercising at different durations and intensities (3 ×10 min of running vs. 60 min of running). Effects of age, gender, cycle phase, and previous running experience were considered in the statistical analyses. Concentrations of oxytocin and cortisol were analysed in both saliva, and urine using validated assays. ResultsRunners of both groups had significantly increased oxytocin concentrations in urine and saliva after running than before. Oxytocin in saliva was elevated after 10 min and peaked after 30 min of running. Only participants of the long-running group showed an increase in urinary cortisol concentrations following exercise (and only after 90 min of stimulus onset), and neither group had a significant increase in salivary cortisol levels. Oxytocin rise in urine and saliva from basal to post-run was strongly and significantly correlated, as was cortisol rise from basal to post-rest, but no correlations between absolute hormone concentrations were found for oxytocin. ConclusionsOur results show that both urine and saliva are useful body fluids that can provide meaningful results when measuring oxytocin and cortisol concentrations after a physical stimulus. While temporal resolution may be better with salivary sampling as higher sampling frequency is possible, signal strength and robustness were better in urinary samples. Importantly, we report a strong correlation between the magnitude of change in oxytocin and cortisol concentrations in urine and saliva following physical exercise, but no correlations between absolute oxytocin concentrations in the two substrates.

Salivary Proteins and Metabolites as Caries Biomarkers in Adolescents.

The identification of salivary molecules that can be associated to dental caries could provide insights about caries risk and offer valuable information to develop caries prediction models. However, the search for a universal caries biomarker has proven elusive due to the multifactorial nature of this oral disease. We have therefore performed a systematic effort to identify caries-associated metabolites and proteins in saliva samples from adolescents that had a caries experience and those that were caries-free. Quantification of approximately 100 molecules was performed by the use of a wide range of techniques, ranging from nuclear magnetic resonance metabolomics to ELISA, Luminex or colorimetric assays, as well as clinical features like plaque accumulation and gingival index. In addition, simplified dietary and oral hygiene habits questionnaires were also obtained. The caries-free group had significantly lower consumption of sweetened beverages and higher tooth brushing frequency. Surprisingly, very few compounds were found to individually provide discriminatory power between caries-experienced and caries-free individuals. The data analysis revealed several potential reasons that could underly this lack of association value with caries, including differences in metabolite concentrations throughout the day, a lack of correlation between metabolite concentrations in plaque and saliva, or sex-related differences, among others. However, when multiple compounds were combined by multivariate analysis and random forest modeling, a combination of 3-5 compounds were found to provide good prediction models for morning (with an AUC accuracy of 0.87) and especially afternoon samples (AUC = 0.93). While few salivary biomarkers could differentiate between caries-free and caries-experienced adolescents, a combination of markers proved effective, particularly in afternoon samples. To predict caries risk, these biomarkers should be validated in larger cohorts and longitudinal settings, considering factors such as gender differences, and variations in oral hygiene and diet.

Monitoring levetiracetam concentration in saliva during pregnancy is stable and feasible.

This multicenter prospective cohort study (registration no. ChiCTR2000032089) aimed to investigate the relationship between saliva and plasma levetiracetam concentrations to determine whether saliva could be used for routine monitoring of levetiracetam during pregnancy. The slot concentrations of levetiracetam in simultaneously obtained saliva and plasma samples were measured using UPLC-MS/MS. The correlations between saliva and plasma levetiracetam concentrations and the dose-normalized concentrations were compared among pregnant women in different stages and nonpregnant control participants with epilepsy. In total, 231 patients with 407 plasma and saliva sample pairs were enrolled from 39 centers. Linear relationships between salivary and plasma levetiracetam concentrations were reported in the enrolled population (r = 0.898, p < 0.001), including pregnant (r = 0.935, p < 0.001) and nonpregnant participants (r = 0.882, p < 0.001). Plasma concentrations were moderately higher than saliva concentrations, with ratios of saliva to plasma concentrations of 0.98 for nonpregnant women, 0.98, 1, and 1.12 for pregnant women during the first trimester, the second trimester, the and third trimester, respectively. The effective range of saliva levetiracetam concentration was found to be 9.98 μg/mL (lower limit) with an area under the curve (AUC) of 0.937 (95% confidence intervals, 0.915-0.959), sensitivity of 88.9%, specificity of 86.8%, and p < 0.001, to 24.05 μg/mL (upper limit) with an AUC of 0.952 (0.914-0.99), sensitivity of 100%, specificity of 92.3%, and p = 0.007. The saliva/plasma concentration ratio of levetiracetam remains constant during pregnancy and is similar to that in non-pregnant individuals. Monitoring levetiracetam concentration in saliva during pregnancy should be widely promoted.