Molecules In Saliva Research Articles

Non-Invasive Point-of-Care Detection of Methamphetamine and Cocaine via Aptamer-Based Lateral Flow Test.

Drug abuse is a major public problem in the workplace, traffic, and forensic issues, which requires a standardized test device to monitor on-site drug use. For field testing, the most important requirements are portability, sensitivity, non-invasiveness, and quick results. Motivated by this problem, a point of care (POC) test based on lateral flow assay (LFA) was developed for the detection of cocaine (COC) and methamphetamine (MET) in saliva which has been selected as the matrix for this study due to its rapid and non-invasive collection process. In the design strategy of an LFA test, the use of gold nanoparticles (AuNPs) with strong optical properties has been combined with the advantages of selecting aptamers under in vitro conditions, making it a highly specific and stable recognition probe for the detection of small molecules in saliva. The developed aptamer-based LFA in a competitive format, was able to detect COC and MET in synthetic saliva at concentrations as low as 5.0 ng/mL. After analytical performance studies, the test system also detected COC and MET in real patient samples, which was verified by chromatographic methods.

Diagnostic potential of salivary IL-1β, IL-8, SAT, S100P, and OAZ1 in oral squamous cell carcinoma, oral submucous fibrosis, and oral lichen planus based on findings from a Sri Lankan cohort

The research examined the salivary concentrations of various biomarkers, such as OAZ1, SAT, S100P, IL-1β, and IL-8 aiming to detect early-stage oral squamous cell carcinoma (OSCC). These biomarkers show potential as indicators for detecting both pre-cancerous and cancerous states within the oral cavity. Analyzing these specific molecules in saliva could help clinicians enhance diagnostic accuracy and refine early detection methods for OSCC. The research encompassed a cohort of nine OSCC patients, ten with oral submucous fibrosis (OSF), eleven individuals with oral lichen planus (OLP), and ten healthy controls. The study focused on assessing the expression levels of key biomarkers—IL-1β, IL-8, SAT, S100P, and OAZ1 mRNA—in extracellular RNA extracted from saliva samples. This evaluation was conducted using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) with sequence-specific primers. Additionally, receiver operating characteristic curve (ROC) curve analysis was employed to gauge the efficacy of these biomarkers in detecting OSCC. Based on the results we observe, when these five biomarkers are used together, they give a 90% predictive probability for patients with OLP, an 80% predictive probability for OSF, and an impressive 100% predictive probability for patients with OSCC (AUC = 1.000, p = 0.000). This study demonstrates the efficacy of salivary transcriptome diagnostics in detecting OSCC. This novel clinical technique has the potential to be a powerful, efficient, and reliable tool for early detection of cancer. Salivary transcriptomes can be further analyzed to evaluate their effectiveness in other important illness contexts and for regular health monitoring.

Evaluation and comparison of colorimetric outputs for yeast-based biosensors in laboratory and point-of-use settings.

Recent research has shown the potential of yeast-based biosensors (YBBs) for point-of-use detection of pathogens and target molecules in saliva, blood, and urine samples. The choice of output can greatly affect the sensitivity, dynamic range, detection time, and ease-of-use of a sensor. For visual detection without the need for additional reagents or machinery, colorimetric outputs have shown great potential. Here, we evaluated the inducible generation of prodeoxyviolacein and proviolacein as colorimetric YBB outputs and benchmarked these against lycopene. The outputs were induced via the yeast mating pathway and were compared on agar plates, in liquid culture, and on paper slips. We found that all three outputs produced comparable pigment intensity on agar plates, making them applicable for bioengineering settings. In liquid media and on paper slips, lycopene resulted in a higher intensity pigment and a decreased time-of-detection.

Changes in the levels of marker molecules salivary α-amylase and cortisol as a stress response to everyday activities of general practitioners in rural areas of the Republic of Bulgaria.

Stress is a phenomenon accompanying everyday life. Various reactions of the body are activated during stress, including activation of the hypothalamo-pituitary-adrenal endocrine axis and the autonomous nervous system. Their activity could be assessed by the measurement of biological stress marker molecules - salivary α-amylase and cortisol - on one side and heart rate, and blood pressure monitoring, on the other. The aim of the present study is to determine whether the daily professional routines cause stress development among general practitioners (GPs) who work in rural, distant areas in the territory of the Republic of Bulgaria. One hundred and twenty-eight GPs were asked to answer a questionnaire to assess their health conditions, habits, priority objectives and interests, as well as their moral and ethical relationships with the patients. On this basis 40 participants were selected and outlined for the present survey (n=40, mean age 55.92±8.8). Four salivary samples were collected from each participant during 1 week: two on Monday (one in the morning and one after work) and two on Friday, by the same mechanism. The salivary samples collection was followed by measurement of blood pressure and pulse. This non-invasive survey was based on an ELISA method for quantitative determination of the marker molecules in saliva. The blood pressure and pulse were measured by blood pressure monitor. The levels of the salivary α-amylase were significantly higher at the end of the working day, especially on Friday (142.28±23.34 U/mL, p=0.018), but not between the beginning and the end of the week. The normal cortisol awakening response, characterized by a peak in the levels of cortisol after wake-up, followed by a slow decrease during the day, was detected only at the beginning of the week. The data show a significant impairment of this regularity at the end of the week. Moreover, the levels of cortisol, measured for the morning samples, show a decrease at the end of the week (25.73±10.51 ng/mL) in comparison to the beginning of the week (30.1±10.84, p=0.033). The analyses on the effect of smoking (p=0.002) and alcohol consumption (p=0.036) on stress development show a significant increase in the levels of the salivary α-amylase, but not on the levels of salivary cortisol. The changes in the blood pressure indicate stress development at the end of the week (p=0.04), while the pulse showed changes within a day rather than during the week. The values of the pulse were higher at the end of the day. The professional lives of the GPs who work in distant and rural places are associated with stress development. Different habits from the daily routine, such as alcohol consumption, smoking and physical activity, could be considered as modulators of stress development.

Immunoregulatory Markers in Human Saliva – A Non-Invasive Approach in the Diagnosis of Oral Precancerous and Cancerous Lesions

Abstract Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral mucosa. Currently, the diagnosis of oral cancer is based on clinical examination and histopathological analysis. Numerous potential biomarkers have been suggested for oral cancer diagnosis, but the results are contradictory. A great achievement could be identification of biomarkers that indicate the early stage and progression of OSCC. Saliva is an easy to obtain biological fluid containing specific molecules for various pathologies. Some reliable saliva molecules described as oral biomarkers for OSCC are cytokines. A number of studies have shown that higher levels of the proinflammatory and proangiogenic cytokines, like IL-8, IL-6 and TNF-α in saliva could be used for early diagnosis of OSCC. Other studies have shown that the levels of some immunosuppressive cytokines (IL-4, IL-10, IL-13 and IL-1RA) are elevated in saliva in OSCC patients compared to controls. The importance of the immunoregulatory molecules as markers for OSCC is debated. Further studies are needed to identify clinically relevant biomarkers for screening and early detection of oral cancer.

Cyclic square-wave voltammetric discrimination of the amphetamine-type stimulants MDA and MDMA in real-world forensic samples by 3D-printed carbon electrodes

3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA), called as “ecstasy”, are the main seized amphetamine-type stimulants consumed worldwide. Based on the voltammetric profiles of MDMA and MDA on 3D-printed carbon-black integrated polylactide, we propose a cyclic square-wave voltammetric (CSWV) approach to detect and discriminate both molecules in saliva and seized samples. CSWV combines enhanced sensitivity of pulsed techniques and mechanistic insights of cyclic voltammetry and herein we propose cyclic scans from 0.0 to +1.5 V and back to 0.0 V in Britton-Robinson buffer (0.12 mol L−1 pH=6.0). The first scan showed oxidation peaks at around +1.1 V for both MDMA and MDA, however, only MDMA showed a second oxidation peak at +1.35 V (stabilization of a cation radical). The reverse scan displayed a reduction peak only for MDA at around +0.2 V (the oxidation product from MDA is only electroactive in the reverse scan). Thus, MDMA can be selectively detected in the forward scan and MDA in the reverse scan. CSWV provided linear ranges from 5.8 to 35.0 µmol L−1 and 3.1 to 21.8 µmol L−1 (r2>0.99) for MDMA and MDA, respectively. Intra-day precision studies (n=10) showed that potential peaks (RSD<0.8%) and current intensity (RSD<3.8%) for all electrochemical processes are repetitive, with LODs lower than 1.8 µmol L−1. Paracetamol, caffeine, amphetamine, methamphetamine, ephylone, lysergic acid diethylamide and a phenethylamine drug (found in ecstasy-like tablets) did not interfere in the detection of MDMA and MDA. Analysis of seized tablets showed results similar to GC-MS. Spiked saliva samples were analyzed (recovery of 83-106%) after dilution in electrolyte. The combination of CSWV and 3D-printed electrodes (disposable devices easily produced in large scale at reduced cost) is highly promising for selective, fast, simple, low-cost, and on-site screening forensics analyses.

Rapid detection of viruses: Based on silver nanoparticles modified with bromine ions and acetonitrile

Nearly 200 million people have been diagnosed with COVID-19 since the outbreak in 2019, and this disease has claimed more than 5 million lives worldwide. Currently, researchers are focusing on vaccine development and the search for an effective strategy to control the infection source. This work designed a detection platform based on Surface-Enhanced Raman Spectroscopy (SERS) by introducing acetonitrile and calcium ions into the silver nanoparticle reinforced substrate system to realize the rapid detection of novel coronavirus. Acetonitrile may amplify the calcium-induced hot spots of silver nanoparticles and significantly enhanced the stability of silver nanoparticles. It also elicited highly sensitive SERS signals of the virus. This approach allowed us to capture the characteristic SERS signals of SARS-CoV-2, Human Adenovirus 3, and H1N1 influenza virus molecules at a concentration of 100 copies/test (PFU/test) with upstanding reproduction and signal-to-noise ratio. Machine learning recognition technology was employed to qualitatively distinguish the three virus molecules with 1000 groups of spectra of each virus. Acetonitrile is a potent internal marker in regulating the signal intensity of virus molecules in saliva and serum. Thus, we used the SERS peak intensity to quantify the virus content in saliva and serum. The results demonstrated a satisfactory linear relationship between peak intensity and protein concentration. Collectively, this rapid detection method has a broad application prospect in clinical diagnosis of viruses, management of emergent viral infectious diseases, and exploration of the interaction between viruses and host cells.

446: Novel detection of specific bacterial quorum-sensing molecules in saliva: Potential noninvasive biomarkers for pulmonary Pseudomonas aeruginosa in cystic fibrosis

446: Novel detection of specific bacterial quorum-sensing molecules in saliva: Potential noninvasive biomarkers for pulmonary Pseudomonas aeruginosa in cystic fibrosis

Novel detection of specific bacterial quorum sensing molecules in saliva: Potential non-invasive biomarkers for pulmonary Pseudomonas aeruginosa in cystic fibrosis

Pseudomonas aeruginosa produces specific signalling molecules, 2-alkyl-4-quinolones (AQs) that are detectable in the sputum of adults with cystic fibrosis (CF) and who have pulmonary infection with this opportunistic pathogen. This study aimed to determine whether AQs could be detected in saliva of patients with CF and known infection with Pseudomonas aeruginosa. Saliva and sputum samples were obtained from 89 adults with CF and analyzed using liquid chromatography-tandem mass spectrometry. AQs were detected in 39/89 (43.8%) saliva samples and 70/77(90.9%) sputum samples. Salivary AQs had a sensitivity of 50% (95%CI; 37.8; 62.2), specificity of 100% (95%CI; 47.8; 100), when compared to a molecular microbiological measure of P. aeruginosa in sputum as measured using polymerase chain reaction. Specific AQs produced by P. aeruginosa can be detected in the saliva and warrant investigation as potential non-invasive biomarkers of pulmonary P. aeruginosa.

Changing the Recipe: Pathogen Directed Changes in Tick Saliva Components.

Ticks are obligate hematophagous parasites and are important vectors of a wide variety of pathogens. These pathogens include spirochetes in the genus Borrelia that cause Lyme disease, rickettsial pathogens, and tick-borne encephalitis virus, among others. Due to their prolonged feeding period of up to two weeks, hard ticks must counteract vertebrate host defense reactions in order to survive and reproduce. To overcome host defense mechanisms, ticks have evolved a large number of pharmacologically active molecules that are secreted in their saliva, which inhibits or modulates host immune defenses and wound healing responses upon injection into the bite site. These bioactive molecules in tick saliva can create a privileged environment in the host’s skin that tick-borne pathogens take advantage of. In fact, evidence is accumulating that tick-transmitted pathogens manipulate tick saliva composition to enhance their own survival, transmission, and evasion of host defenses. We review what is known about specific and functionally characterized tick saliva molecules in the context of tick infection with the genus Borrelia, the intracellular pathogen Anaplasma phagocytophilum, and tick-borne encephalitis virus. Additionally, we review studies analyzing sialome-level responses to pathogen challenge.

Common Salivary Protein 1 in Saliva of Diabetes Patients (II).

Human common salivary protein 1 (CSP1) is one of a variety of molecules in saliva but its function remains to be determined. The gold standard method for diagnosis of diabetes mellitus (DM) is to check levels of glucose or HbA1C in plasma or serum. The purpose of this study was to examine whether Salivary CSP1 concentration would be useful alternative for DM diagnosis. The qualities of monoclonal antibodies (mAbs) to recombinant human CSP1 (rhCSP1) were tested by western blotting (WB) and immunohistochemistry. A sandwich ELISA was fabricated with the qualified capture and detector mAbs for measurement of CSP1 level in saliva. CSP1 levels of healthy adults and DM patients were measured by the sandwich ELISA and their results were statistically analyzed by Student's t-test. The receiver operating characteristic (ROC) curve was constructed and the area under the curve (AUC) was calculated. The tested mAbs recognized a 27-kDa CSP1 of saliva in WB and stained only a salivary gland in immunohistochemistry. Pearson's correlation coefficient with standard curve between OD450nm value vs. CSP level showed good linearity (r2 = 0.995). The median values (25th to 75th percentiles) of saliva CSP1 in 10 healthy adults and 18 DM patients using the sandwich ELISA were 3.92 µg/mL (3.15 - 4.02) and 4.35 µg/mL (3.94 - 5.11), respectively. Statistically, there was a significant difference of CSP1 level in two groups (p = 0.026). The sensitivity value of CSP1 was 64.71 while the specificity value was 88.89 with 0.784 of AUC (p = 0.003). These results suggested that the fabricated sandwich ELISA was a good diagnostic test tool for discriminating DM patients from healthy individuals. The present data showed a significant increase of CSP1 levels for DM patients compared with control group, indicating that CSP1 level in saliva could be used as a potential biomarker of detection or screening of DM patients. However, further studies are necessary to provide scientific and clinical validation.

Rational Design of Stimuli-Responsive Polymers Modified Nanopores for Selective and Sensitive Determination of Salivary Glucose.

The great pain and stress from finger-prick glucose measurements have resulted in great motivation to find noninvasive glucose monitoring technologies where salivary glucose measurement is desirable. However, the relative low concentration of glucose and coexisting chemicals in saliva challenges the sensitive and selective salivary glucose detection. In this article, we have rationally designed and constructed a salivary glucose sensor by modifying the inner wall of the Au-decorated glass nanopore with stimuli-responsive copolymer poly(3-(acryloylthioureido) phenylboronic acid-co-N-isopropylacrylamide) (denoted as PATPBA-co-PNIPAAm) via Au-S interaction. Notably, upon recognition of glucose, the copolymer could undergo a wettability switch and pKa shifts in the boronic acid functional groups, which significantly regulated the ion transport through nanopores, thus showing improved sensitivity with the detection limit of 1 nM. Moreover, benefiting from the multivalent boronic acid-glucose interaction and the cooperation of thiourea units, the copolymer exhibited good selectivity for glucose detection against the coexisting saccharides and other biological molecules in saliva. The nanopores with well-demonstrated analytical performance were finally applied for monitoring glucose in saliva. Together, this work unveiled a new platform for glucose detection in saliva, and promised to provide a new strategy for detecting other biomolecules in accessible biofluid involved in physiological and pathological events.

A novel boar pheromone mixture induces sow estrus behaviors and reproductive success

Androstenone is a molecule found in boar saliva and fat, which has been thought to be the male pig sexual pheromone. We previously identified and confirmed three boar-unique molecules in saliva, namely, quinoline (Q), androstenol (AL) and androstenone (AN). This study quantified the sexual behavioral responses of the molecules among post-weaning sows (days 4 and 5). Among 947 weaned sows, the percentage of sexual behaviors was increased by Boar Saliva Analog (BSA; a mixture of Q, AL and AN) relative to a vehicle control (isopropyl alcohol; ISO) or each molecule alone. A sexual behavior score was calculated for each molecule that combined standing still, pricked ears and vocalizations. BSA caused an increase in the standing reflex (standing still), pricked ears and vocalizations compared to ISO. BSA increased sexual behavior score by 63.9% over ISO while androstenone increased the sexual behavior score by only 13.5% over ISO. BSA was more effective than androstenone alone in the induction of sexual behaviors. It cuased more weaned sows to express behavioral estrus and to stand for insemination at a higher rate than boar exposure alone. Thus, the overt expression of sexual behaviors in weaned sows caused by BSA strongly suggests that the boar sexual pheromone is likely to be a mixture of three unique volatile molecules.

Salivary microRNA for diagnosis of systemic diseases and malignant tumors: a systematic review

Event Abstract Back to Event Salivary microRNA for diagnosis of systemic diseases and malignant tumors: a systematic review Maria Vittoria Viani1*, Margherita Eleonora Pezzi1, Emanuela Casali1, Antonino Musolino2, Paolo Vescovi1 and Marco Meleti1 1 University of Parma, Department of Medicine and Surgery, Italy 2 Azienda Ospedaliero-Universitaria di Parma, Department of General and Specialistic Medicine, Italy Aim. Salivary transcriptomics is an relatively new field of research that will probably allow in the next feature the development of some non-invasive diagnostic techniques. Among transcripts, microRNAs (miRNA) , small non-coding RNA molecules which regulate the expression of target genes seem to be the most promising molecules. Expression of several miRNAs are associated with the development of specific human diseases, including malignant tumours. The aim of the present research is to perform a systematic review in order to establish if there is scientific evidence supporting the role of salivary miRNA for the diagnosis of systemic diseases and malignant tumors. Materials and Methods. We searched into the Medline database, using as entry terms “salivary microRNA”, “saliva and microRNA”, “saliva and tumor”, “saliva and cancer”, “saliva and carcinoma”, “saliva and malignancies” and “saliva and systemic diseases”. Only articles in English and published after 2000 were included in the review. Inclusion criteria were established including only studies specifically reporting data on saliva sample; studies analyzing peculiar microRNA; studies evaluating patients with systemic diseases where miRNA were used diagnostic purpose. We excluded studies on animals or in vitro samples and papers dealing with systemic microbial infections, hormones, drug dosage. Case reports, conference proceedings, personal communication and reviews were also excluded. We further excluded researches investigating salivary biomarkers in patients with systemic diseases with oral, oropharyngeal and esophageal involvement. References listed in reviews, were screened in order to identify papers possibly missing from the database search. From each studies we extrapolated title, authors, publication year, systemic diseases, type of miRNA, devices used for analyse the samples and significances of results. We divided studies on the basis of the disease. Qualitative analysis was performed using as tool for quality score assessment the guidelines provided by the National Institute of Health (NIH - scores ranging from “poor” to “good”). Results. The preliminary research initially obtained 12327 papers. After exclusion of repetition 3422 papers were included for further evaluation. The evaluation of title, abstract and the application of inclusion and exclusion criteria eventually led to the identification of 6 articles. One more study was obtained from screening of reference list. Four studies were focused on pancreatic cancer (among others miRNA identified were the following: miR‑1246, miR‑3976, miR‑4306,miR‑4644, miR-21,miR-34a, miR-155, miR-196a, miR-200b, miR-376a, hsa-miR-23a, hsa-miR-23b, miR-29c, hsa-miR-210, miR-4433-5p, miR-4665-3p, miR-940, miR-1273g-3p, miR-3676-5p, miR-3679-5p, miR-3940-5p, miR-4327, miR-4442 and miR-5100), one on bowel inflammatory diseases (miRNA identified: miR-19a, miR-21, miR-31, miR-101, miR-146a, and miR-375), one on colorectal cancer (miR-21) and one on prostate cancer (miR-141, miR-21). Six articles searched miRNA through quantitative real-time PCR and one article used RNA microarray. Most of studies (6 on seven) obtained statistically significant association between miRNA and the specific disease. Only one study obtained no significant results. Following the NIH guidelines, 5 studies were scored as “fair” (4 studies on pancreatic cancer and one on colorectal cancer) and two studies were scored as “poor” (bowel inflammatory diseases and prostate cancer). No one of the papers could be identified has having a “good” quality. Discussion. The results of our review highlight the paucity of papers focused on early diagnosis of systemic diseases through salivary miRNA. The few number and the low quality of articles show the necessity of more comprehensive studies. More studies are needed, also on the basis of the encouraging results obtained from each experiment (statistically significant correlation) and the relatively high quantitative of such molecules in saliva. Particularly, mir21 seems to be the salivary miRNA molecule present in most of the diseases studied.

De novo assembly and annotation of Hyalomma dromedarii tick (Acari: Ixodidae) sialotranscriptome with regard to gender differences in gene expression

BackgroundHard ticks are hematophagous ectoparasites characterized by their long-term feeding. The saliva that they secrete during their blood meal is their crucial weapon against host-defense systems including hemostasis, inflammation and immunity. The anti-hemostatic, anti-inflammatory and immune-modulatory activities carried out by tick saliva molecules warrant their pharmacological investigation. The Hyalomma dromedarii Koch, 1844 tick is a common parasite of camels and probably the best adapted to deserts of all hard ticks. Like other hard ticks, the salivary glands of this tick may provide a rich source of many compounds whose biological activities interact directly with host system pathways. Female H. dromedarii ticks feed longer than males, thereby taking in more blood. To investigate the differences in feeding behavior as reflected in salivary compounds, we performed de novo assembly and annotation of H. dromedarii sialotranscriptome paying particular attention to variations in gender gene expression.ResultsThe quality-filtered Illumina sequencing reads deriving from a cDNA library of salivary glands led to the assembly of 15,342 transcripts. We deduced that the secreted proteins included: metalloproteases, glycine-rich proteins, mucins, anticoagulants of the mandanin family and lipocalins, among others. Expression analysis revealed differences in the expression of transcripts between male and female H. dromedarii that might explain the blood-feeding strategies employed by both genders.ConclusionsThe annotated sialome of H. dromedarii helps understand the interaction of tick-host molecules during blood-feeding and can lead to the discovery of new pharmacologically active proteins of ticks of the genus Hyalomma.

Design and Development of Electrochemical Analyzer for Detection of Δ9-Tetrahydrocannabinol (THC)

Δ9-Tetrahydrocannabinol (THC), the active substance in marijuana, is known to reduce psychomotor function and cognition thus greatly impairing driving ability. Existing THC detection technologies (urine or blood-based) are not adequate for assessing recent exposure to determine if a driver is operating under the influence. Giner describes a novel approach which involves the utilization of inexpensive disposable electrodes and electrochemical measurements to detect the presence and abundance of target THC molecules in saliva. Saliva testing via electrochemical detection will eliminate the need for expensive and time-consuming analytical techniques which have a turnaround time of several days.

Tick-host-pathogen systems immunobiology: an interactive trio.

Significant new insights are being made into tick modulation of host immune defenses and the implications of those host defense changes on tick-borne pathogen transmission and establishment of infection. Understanding tick saliva complexity increased with construction and analyses of salivary gland cDNA libraries. High throughput next generation sequencing and advances in proteomics are revealing greater complexity of saliva, nature of gene families and differential gene expression patterns not previously attainable. Combined use of genome arrays and histopathology are defining cutaneous gene expression during the course of infestation with pathogen-free ticks and during infestations with ticks experimentally infected with a tick-borne pathogen. Large data sets are being generated that are of value to researchers. A major challenge remains in linking saliva molecules with specific functions. Systems biology technologies provide the tools for analyses of complex tick-host-pathogen interactions that are the underpinnings for development of novel control strategies for ticks and tick-borne diseases of medical and veterinary public health importance.

Age-dependent capillary thinning dynamics of physically-associated salivary mucin networks

Human whole saliva consists of a physically-associated network of mucin molecules. The interchain physical associations control the rheological characteristics of the solution and in particular, the lifetime of filaments and threads. Measurements show that the shear rheology of salivary mucin solutions (as measured by steady shear viscosity and small amplitude oscillatory shear) is quite insensitive to sample age over a 24 h period following sample collection. By contrast, the filament thinning dynamics vary dramatically, with the characteristic relaxation time of the saliva and the breakup time of a fluid thread decreasing significantly with sample age. We interpret our results within the framework of a sticky finitely extensible network model which respects the known physical dimensions and properties of the mucin molecules in saliva and models them as a network of physically associating and finitely extensible polymer chains. The model predicts an initially strain-hardening response in the transient ex...

Substrate prediction of Ixodes ricinus salivary lipocalins differentially expressed during Borrelia afzelii infection.

Evolution has provided ticks with an arsenal of bioactive saliva molecules that counteract host defense mechanisms. This salivary pharmacopoeia enables blood-feeding while enabling pathogen transmission. High-throughput sequencing of tick salivary glands has thus become a major focus, revealing large expansion within protein encoding gene families. Among these are lipocalins, ubiquitous barrel-shaped proteins that sequester small, typically hydrophobic molecules. This study was initiated by mining the Ixodes ricinus salivary gland transcriptome for specific, uncharacterized lipocalins: three were identified. Differential expression of these I. ricinus lipocalins during feeding at distinct developmental stages and in response to Borrelia afzelii infection suggests a role in transmission of this Lyme disease spirochete. A phylogenetic analysis using 803 sequences places the three I. ricinus lipocalins with tick lipocalins that sequester monoamines, leukotrienes and fatty acids. Both structural analysis and biophysical simulations generated robust predictions showing these I. ricinus lipocalins have the potential to bind monoamines similar to other tick species previously reported. The multidisciplinary approach employed in this study characterized unique lipocalins that play a role in tick blood-feeding and transmission of the most important tick-borne pathogen in North America and Eurasia.

Determination of creatinine-related molecules in saliva by reversed-phase liquid chromatography with tandem mass spectrometry and the evaluation of hemodialysis in chronic kidney disease patients

The serum concentrations of creatinine (Cre) and urea are used for the determination of the renal function. However, the use of blood is not always suitable due to the invasive, hygienic and infection problems during its sample collection and handling. In contrast, saliva is relatively clean and the samples can be quickly and noninvasively collected and easily stored. Therefore, the simultaneous determination of Arginine (Arg), creatine (Cr) and Cre in the saliva of chronic kidney disease (CKD) patients was performed by UPLC-ESI-MS/MS together with the saliva of healthy volunteers. The evaluation of hemodialysis of CKD patients was also carried out by the determinations before and after the dialysis. An HS-F5 column was used for the simultaneous determination of Arg, Cr and Cre in the saliva. These molecules were rapidly separated within 4 min and sensitively determined by the multiple reaction monitoring (MRM) of the precursor ion [M+H]+ → product ions (m/z 175.1 → 70.1 for Arg; m/z 132.0 → 44.1 for Cr; m/z 114.0 → 44.1 for Cre). The concentration of Cre in the CKD patients was higher than that in the healthy persons. The concentrations of Cre in the saliva of the patients before hemodialysis were moderately correlated with the serum Cre concentrations (R2 = 0.661). Furthermore, the concentration in the saliva obviously decreased after hemodialysis (before 0.73 mg/dL, after 0.25 mg/dL; p < 0.02). Thus, the proposed detection method using saliva by UPLC-MS/MS is useful for the evaluation of the renal function in CKD patients. The present method offers a new option for monitoring the hemodialysis of CKD patients.