One-step homogeneous C-reactive protein assay for saliva

Salivary C-reactive protein exhibits a diurnal pattern and relates to biobehavioral health in military men

C-reactive protein is a systemic inflammatory biomarker that is positively associated with the development of disease. Salivary C-reactive protein (sCRP) has previously been reported to have a diurnal rhythm with higher levels upon awakening and lower levels thereafter. The aims of this study were to evaluate the stability of sCRP across two days, characterize the daily sCRP pattern, compute morning sCRP parameters, and evaluate associations with biobehavioral health in US Navy Explosive Ordnance Disposal (EOD) technicians. Seventy male EOD technicians (age = 34.9 ± 6.5 years) participated in this study, which included a tablet-based survey, measures of health and fitness, and saliva collection. In a free-living setting, participants self-collected saliva on 2 consecutive days at WAKE, WAKE+30, WAKE+60, 4p.m., and 9p.m., for a total of 10 samples. Parameters (e.g., area under the curve) were computed to characterize the morning sCRP magnitude and pattern. Pearson product-moment correlation analyses were used to assess the stability of sCRP samples and parameters across the study period and to examine associations with biobehavioral health. Average sCRP concentrations for the 2-day period were evaluated using an analysis of variance with repeated measures. The stabilities between corresponding time points on Days 1 and 2 were very high (rs = 0.87-.94, all ps ≤ 0.001). sCRP concentrations were highest at WAKE, decreased by 73.6 % at WAKE+30, and then plateaued for the rest of the day. Parameter stabilities were good to excellent (rs = 0.77-.98, all ps ≤ 0.001). We also observed associations between sCRP parameters, self-reported health behaviors, and objective measures of health and fitness. In this study of a military population, we characterized sCRP as diurnal with robust stability across 2 consecutive days, which demonstrates the feasibility of sCRP as a biomarker. These results have significant implications for study methodology and for using sCRP as a marker of dysfunction or disease.

Versatile conductometric biosensors for rapid and selective detection of inflammatory and cardiac biomarkers in saliva

Biosensors have become promising alternatives to the conventional methods in early identification of diseases. However, translation of biosensors from lab to commercial products have challenges such as complex sensor fabrications and complicated detection, and inadequate sensitivity and selectivity. Here, we introduce simple and low-cost fabricated conductometric sensors based on high resistivity silicon wafers (HR-Si) which can be adopted to functionalise with both natural and synthetic antibodies in detecting five biomarkers including interleukin-6, C reactive protein, cardiac troponin I, brain natriuretic peptide, and N terminal-probrain natriuretic peptide. All five biomarkers show selective and rapid (10 min sample incubation and <1 min of reading time) detection in both media of phosphate buffer saline and saliva with the detection limits lower than that of reported healthy levels in saliva. This work highlights the versatility of HR-Si sensors in functionalisation of both natural and synthetic antibodies in sensitive and selective biomarker detection. As these miniaturised conductometric biosensors can be easily modified with on-demand biomaterials to detect corresponding target biomarkers, they enable a new category of compact point-of-care medical devices.

Hybrid Integration of Wearable Devices for Physiological Monitoring

Wearable devices can provide timely, user-friendly, non- or minimally invasive, and continuous monitoring of human health. Recently, multidisciplinary scientific communities have made significant progress regarding fully integrated wearable devices such as sweat wearable sensors, saliva sensors, and wound sensors. However, the translation of these wearables into markets has been slow due to several reasons associated with the poor system-level performance of integrated wearables. The wearability consideration for wearable devices compromises many properties of the wearables. Besides, the limited power capacity of wearables hinders continuous monitoring for extended duration. Furthermore, peak-power operations for intensive computations can quickly create thermal issues in the compact form factor that interfere with wearability and sensor operations. Moreover, wearable devices are constantly subjected to environmental, mechanical, chemical, and electrical interferences and variables that can invalidate the collected data. This generates the need for sophisticated data analytics to contextually identify, include, and exclude data points per multisensor fusion to enable accurate data interpretation. This review synthesizes the challenges surrounding the wearable device integration from three aspects in terms of hardware, energy, and data, focuses on a discussion about hybrid integration of wearable devices, and seeks to provide comprehensive guidance for designing fully functional and stable wearable devices.

Exploring the Relationship Between Stress, Salivary C-Reactive Protein, and Embodied Physiological Responses in a Nigerian Population

OBJECTIVES

The impacts of stress on inflammation, although hypothesized, have not been thoroughly examined, especially in relation to social and environmental factors and particularly within Black populations. This study aims to explore the biological mechanisms of embodiment linking stress and health to understand physiological changes in the body's response to psychological stress in a Nigerian population. Through a multidisciplinary approach, this study queries the relationship between stress, cortisol, and salivary C-reactive protein (sCRP), a biomarker of inflammation, while also validating the use of sCRP as a potential and accurate stress indicator in the field.

METHODS

In this cross-sectional study, 138 passive drool saliva samples (nfemale = 89 nmale = 49) were collected and assessed for sCRP and cortisol levels in adults. Participants also completed a short demographic survey and, to measure psychological stress, the General Health Questionnaire 12 (GHQ-12). Relationships between sCRP and stress-related variables (i.e., cortisol, GHQ-12, and demographic data) were assessed using Spearman's correlations, simple regression, multivariable linear regression, and exploratory factor analysis.

RESULTS

sCRP levels ranged from 20.57 to 6879.41 pg/mL across all samples, with significant differences between female and male participants. The GHQ-12 was not a significant predictor of sCRP variability. However, socio-demographic factors such as body mass index (BMI), age, self-reported sex, ethnic identity, and cortisol were significant predictors, collectively explaining 24%-27% of the variation in sCRP.

CONCLUSION

Socio-demographic predictors like BMI, age, sex, and particularly ethnic group experience in Nigeria encapsulate aspects of embodied stress, that significantly affect sCRP variability.

Effects of stannous fluoride dentifrice on gingival health and oxidative stress markers: a prospective clinical trial

BACKGROUND

Periodontal disease results in oral dysbiosis, increasing plaque virulence and oxidative stress. Stannous fluoride (SnF2) binds lipopolysaccharides to reduce plaque virulence. This study prospectively assessed SnF2 effects on oxidative stress in adults with gingivitis.

METHODS

This was a 2-month, single-center, single-treatment clinical trial. Twenty "disease" (> 20 bleeding sites with ≥ 3 pockets 3 mm-4 mm deep) and 20 "healthy" (≤ 3 bleeding sites with pockets ≤ 2 mm deep) adults were enrolled. All participants were instructed to use SnF2 dentifrice twice daily for 2 months. An oral examination, Modified Gingival Index (MGI) examination and Gingival Bleeding Index (GBI) examination were conducted at baseline, 1 month and 2 months. Gingival crevicular fluid (GCF), saliva, oral lavage and supragingival plaque were collected at each visit to evaluate: Endotoxins, Protein Carbonyls, L-lactate dehydrogenase (LDH), Ferric reducing antioxidant power (FRAP), Oxidized low density lipoproteins (oxi-LDL), IL-6 and C-reactive protein (CRP). A subset-analysis examined participants considered at higher risk of cardiovascular disease. Change-from-baseline analyses within each group were of primary interest.

RESULTS

The disease group showed statistically significant reductions in GBI at Month 1 (67%) and Month 2 (85%) and in MGI at Month 1 (36%) and Month 2 (51%) versus baseline (p < 0.001). At baseline, the disease group showed greater LDH in GCF and oxi-LDL levels in saliva versus the healthy group (p ≤ 0.01). Total antioxidant capacity (FRAP) in saliva increased versus baseline for the disease group at Months 1 and 2 (p < 0.05), and levels for the disease group were greater than the healthy group at both timepoints (p < 0.05). SnF2 treatment reduced endotoxins (lavage) for both disease and healthy groups at Month 2 (p ≤ 0.021) versus baseline. There was a reduction in oxidative stress markers, namely protein carbonyl in saliva, at Months 1 and 2 (p < 0.001) for both groups and a reduction in cytokine IL-6 (lavage) in the disease group at Month 2 (p = 0.005). A subset analysis of participants at higher coronary disease risk showed reductions in endotoxins in lavage, oxi-LDL, and CRP in saliva at Month 2 (p ≤ 0.04).

CONCLUSION

SnF2 dentifrice use reversed gingival inflammation, suppressed endotoxins and reduced some harmful oxidant products in saliva and gingiva.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT05326373, registered on 13/04/2022.

Advances and Challenges in SARS-CoV-2 Detection: A Review of Molecular and Serological Technologies

The urgent need for accurate COVID-19 diagnostics has led to the development of various SARS-CoV-2 detection technologies. Real-time reverse transcriptase polymerase chain reaction (RT-qPCR) remains a reliable viral gene detection technique, while other molecular methods, including nucleic acid amplification techniques (NAATs) and isothermal amplification techniques, provide diverse and effective approaches. Serological assays, detecting antibodies in response to viral infection, are crucial for disease surveillance. Saliva-based immunoassays show promise for surveillance purposes. The efficiency of SARS-CoV-2 antibody detection varies, with IgM indicating recent exposure and IgG offering prolonged detectability. Various rapid tests, including lateral-flow immunoassays, present opportunities for quick diagnosis, but their clinical significance requires validation through further studies. Challenges include variations in specificity and sensitivity among testing platforms and evolving assay sensitivities over time. SARS-CoV-2 antigens, particularly the N and S proteins, play a crucial role in diagnostic methods. Innovative approaches, such as nanozyme-based assays and specific nucleotide aptamers, offer enhanced sensitivity and flexibility. In conclusion, ongoing advancements in SARS-CoV-2 detection methods contribute to the global effort in combating the COVID-19 pandemic.

Electrochemical Immunosensor for the Quantification of Galectin-3 in Saliva

Heart failure (HF) is an emerging epidemic and remains a major clinical and public health problem. Advances in the healthcare management of HF may lead to lower morbidity and mortality rates but require diagnostics to guide the process. Current diagnostics/prognostics approaches rely on expensive equipment, centralized facilities and trained personnel, marginalizing healthcare access in developing countries and rural communities. These issues have led researchers to focus on developing portable and affordable diagnostics that can be deployed at the point-of-care (POC). Typically, HF biomarkers are measured in blood not saliva. Recently, our team correlated concentrations of salivary Galectin-3 (Gal-3) to outcomes in patients with HF. We have developed an analytical device which consists of an immunoassay based on a screen-printed carbon electrode (SPCE) to quantify Gal-3 levels in saliva samples. Using 10 μL of saliva, the proposed electrochemical immunoassay achieved a concentration dependent signal response in the clinically relevant range with a limit of detection of 9.66 ng/mL. In addition, the storage stability of the modified electrode was investigated, and only a 10.9% loss in current response over a 35-day period. The results of the immunoassay on the modified SPCEs suggest validity as a POC biosensor system for the management of HF.

One-step paper-based SlipChip for the sensitive detection of C-reactive protein with porous platinum nanozyme-assisted signal amplification

The development of efficient and sensitive point-of-care testing is crucial for preparedness in the post-pandemic era. Although paper-based lateral flow assays have attracted attention and have various advantages for rapid, on-site diagnosis, they have low sensitivity. To overcome the limitations of the existing assays, in this study, we aimed to develop a new, one-step, nanozyme-amplified SlipChip for the sensitive detection of C-reactive protein (CRP). The SlipChip was constructed by combining wax-printed paper with different channel designs. The three-dimensional (3D) fluidic configuration of the SlipChip allowed for the sequential delivery of reagents, enabling mixing and signal amplification with a one-step sliding operation. As a signal-amplifying reagent, peroxidase-mimicking porous platinum nanozyme (pPtNZ) was synthesized using a simple wet chemical method. The pPtNZ conjugated on the test line catalyzes the oxidation of diaminobenzidine (DAB) in the presence of hydrogen peroxide, increasing the color intensity. The immunoassay results of the SlipChip were easily interpreted within 20 min, and the color intensity was visually enhanced by DAB precipitation over time, resulting in up to 6-fold signal amplification. The proposed pPtNZ-SlipChip exhibited high analytical performances for the one-step detection of serum and salivary CRP from 0.1 to 1000 ng/mL, with a limit of detection of 0.03 ng/mL. These results revealed the potential and applicability of the pPtNZ-SlipChip, with the advantages of simplicity, sensitivity, low cost, and portability for on-site detection and point-of-care testing.

Correlation of serum biochemical parameters and saliva pH in healthy individuals

Saliva has the potential to work alongside needles in standard medical diagnosis. Yet the number of studies aimed at deciphering the biochemical communication between saliva and the rest of the body's systems is still very limited. The aim of this study is to investigate the interfluid interaction between saliva and serum by determining the correlation between saliva pH and serum biochemical parameters under mild conditions. Ultimately, using saliva may provide a stress-free diagnostic tool, but more ambitiously, the pH of saliva could present a genuine cost-effective screening tool that may immensely benefit areas with limited access to health care and diagnostic labs. Saliva and blood samples were collected from 43 randomly selected children (7-12 years), living in Jeddah, free from obesity and chronic or systemic body and mouth diseases. A complete serum biochemical analysis was performed, and the salivary pH of all samples was measured immediately at the time of collection. The correlations between saliva pH and serum biochemical parameters were investigated using Univariate and multiple linear regression models. Our results showed that pH has a weak significant positive correlation with total protein and a negative weak significant correlation with urea. Weak correlations suggest the existence of more serum factors to be investigated for their effect on the pH using a stepwise multiple linear regression. The multiple linear models' calculated saliva pH values were close to the measured values, demonstrating its possible capacity to predict saliva pH using serum parameters. The regression model's successful prediction of saliva pH using serum biochemicals reflects the significant correlations between the body fluids' parameters and invites more research to elucidate these relationships.

Advances in Electrochemical Biosensors Based on Nanomaterials for Protein Biomarker Detection in Saliva

The focus on precise medicine enhances the need for timely diagnosis and frequent monitoring of chronic diseases. Moreover, the recent pandemic of severe acute respiratory syndrome coronavirus 2 poses a great demand for rapid detection and surveillance of viral infections. The detection of protein biomarkers and antigens in the saliva allows rapid identification of diseases or disease changes in scenarios where and when the test response at the point of care is mandated. While traditional methods of protein testing fail to provide the desired fast results, electrochemical biosensors based on nanomaterials hold perfect characteristics for the detection of biomarkers in point-of-care settings. The recent advances in electrochemical sensors for salivary protein detection are critically reviewed in this work, with emphasis on the role of nanomaterials to boost the biosensor analytical performance and increase the reliability of the test in human saliva samples. Furthermore, this work identifies the critical factors for further modernization of the nanomaterial-based electrochemical sensors, envisaging the development and implementation of next-generation sample-in-answer-out systems.

SARS-CoV-2 and omicron variant detection with a high selectivity, sensitivity, and low-cost silicon bio-nanosensor

The recent SARS-CoV-2 pandemic has highlighted the urgent need for novel point-of-care devices to be promptly used for a rapid and reliable large screening analysis of several biomarkers like genetic sequences and antibodies. Currently, one of the main limitations of rapid tests is the high percentage of false negatives in the presence of variants and, in particular for the Omicron one. We demonstrate in this work the detection of SARS-CoV-2 and the Omicron variant with a cost-effective silicon nanosensor enabling high sensitivity, selectivity, and fast response. We have shown that a silicon (Si) nanowires (NW) platform detects both Sars-CoV-2 and its Omicron variant with a limit of detection (LoD) of four effective copies (cps), without any amplification of the genome, and with high selectivity. This ultrasensitive detection of 4 cps allows to obtain an extremely early diagnosis paving the way for efficient and widespread tracking. The sensor is made with industrially compatible techniques, which in perspective may allow easy and cost-effective industrialization.

Ultrasensitive aptamer-functionalized Cu-MOF fluorescent nanozyme as an optical biosensor for detection of C-reactive protein

In the present work, an aptasensing method based on integration of RNA on Cu-MOF was developed for detection of C-Reactive Protein (CRP). Cu-MOF showed stimulated fluorescence and mimetic peroxidase enzymatic activity at the time and can be used as dual-signal transduction. CRP binding RNA was used as a highly selective recognition element and immobilized on the Cu-MOF. The immobilized RNA can block the peroxidase activity and fluorescence of the signal traducer probe. Adding CRP to the RNA/Cu-MOF will release RNA from the surface of Cu-MOF and recover both the stimulated fluorescence and peroxidase activity. A biosensor was built for detection of CRP using the two modes of transduction, either colorimetry or fluorometry. A dynamic linear range was obtained from 0.1 to 50 ng mL ^-1with a limit of detection (LOD) as small as 40 pg mL ^-1was calculated in fluorescence mode and 240 pg mL ^-1 as LOD in colorimetry mode. The LODs are lower than the LOD of nephelometric techniques used in clinical practice and is comparable to the normal clinical cutoff value in high-sensitivity CRP assays (1 μg/mL). The aptasensor was successfully applied for detection of CRP in Covid-19 patients with spike recoveries between 84 and 102% and RSD from 0.94% to 2.05%.

High Commitment Work System and Employee Proactive Behavior: The Mediating Roles of Self-Efficiency and Career Development Prospect

At present, proactive behavior has become a major concern in the field of organizational behavior. Drawing from the proactive motivation theory, this article proposes the influence of a high commitment work system (HCWS) on employees' proactive behavior and constructs the mediation model, including self-efficacy and career development prospect. Moreover, conformity values as a micro context factor are used to illustrate the process that affects employees' proactive behavior. Analyzing the matched data from 117 enterprises and 1,055 employees, this article finds that HCWS are positively related to employees' proactive behavior. This article also finds that self-efficacy and career development prospect are mediated by the relationship between HCWS and employees' proactive behavior. Conformity value moderates the positive relationship between self-efficacy and employees' proactive behavior, but it does not moderate the positive relationship between career development prospect and employees' proactive behavior. This study sheds light on whether and how line managers' leadership influences the human resource management (HRM) process.

Performance Monitoring, Subordinate's Felt Trust and Ambidextrous Behavior; Toward a Conceptual Research Framework

The present research proposes an electronic performance monitoring framework based on ambidextrous leadership and social exchange theories in a dynamic environment. It reviews and integrates essential literature on electronic performance management (EPM), trust, and ambidextrous behavior. For this, authors have reviewed relevant literature on various themes and underpinned them for managing EPM. The study emphasizes individuals' psychological foundations that demonstrate trust behavior and relationship with their leaders. Eventually, through an ambidextrous approach, managers gain steady performance and relationships with their subordinates through EPM. The study shows that ambidexterity benefits organizations; it enhances employees' resources, resulting in enhanced performance that leads to the performance of an organization. The authors discuss the theoretical as well as practical implications of this study.

Lack of Evidence for a Relationship Between Salivary CRP and Women's Sexual Desire: An Investigation Across Clinical and Healthy Samples

BACKGROUND

Inflammation has been linked to a variety of mental and physical health outcomes that disproportionately impact women, and which can impair sexual function; thus, there is reason to expect a link between inflammation and women's sexual functioning.

AIM

To test the hypothesis that higher concentrations of C-reactive protein (CRP), a general biomarker of inflammation, would predict women's lower sexual desire.

METHOD

As 2 independent research teams, we conducted 3 separate studies (total n = 405) that assessed salivary CRP and various measurements of sexual desire in different women populations.

OUTCOMES

Female Sexual Function Index, Sexual Desire Inventory-2, Decreased Sexual Desire Screener, and Sexual Interest and Desire Inventory.

RESULTS

Regardless of the way sexual desire was measured (e.g., state vs trait; general desire vs. desire functioning) and the population sampled (i.e., healthy vs. clinically diagnosed with sexual dysfunction), all the studies revealed null results.

CLINICAL IMPLICATIONS

While exploratory, the convergence of these null results across studies and researchers suggests that if there is an association between inflammation and women's sexual desire, it is likely very subtle.

STRENGTHS & LIMITATIONS

Across 2 independent research teams, 3 unrelated studies, and various measurements of sexual desire, results were consistent. These points lend to the generalizability of the results. However, study designs were cross-sectional.

CONCLUSIONS

Future research may reveal (i) a non-linear threshold effect, such that inflammation does not begin to impact women's sexual desire until it is at a high level, (ii) inflammatory biomarkers other than CRP might be more sensitive in detecting associations between inflammation and desire, should they exist, or (iii) the mechanisms underlying sexual dysfunction may differ between sexes. Clephane K, et al. Lack of Evidence for a Relationship Between Salivary CRP and Women's Sexual Desire: An Investigation Across Clinical and Healthy Samples. J Sex Med 2022;19:745-760.

The expression of salivary microRNAs in oral lichen planus: Searching for a prognostic biomarker

Oral lichen planus (OLP) is a premalignant disease with unknown etiology. It has been demonstrated that inflammation and immune activation play a central role in the pathogenesis of OLP. Various cellular and molecular mechanisms are involved in the pathogenesis of OLP. Studies have shown that 2-7% of OLP patients develop oral squamous cell carcinoma (OSCC). As a result, determining the prognosis of the disease will be promising in preventing oral carcinoma. MicroRNAs are involved in the regulation of cytokine expression and cytokines have a central role in the pathogenesis of OLP. As a result, their evaluation in body fluids may be helpful in assessing the disease's status and progression, and facilitating the treatment process. In this regard, much attention has been paid to the saliva of OLP patients as the sampling is cost-effective and non-invasive. Here, we discuss the potential of miRNAs in predicting the disease severity and progression.

Comparison of C-Reactive Protein in Dried Blood Spots and Saliva of Healthy Adolescents

Background/Aim

Determining C-reactive protein (CRP) by non-invasive methods is of great interest for research addressing inflammation in young people. However, direct comparisons of such methods applied in children and adolescents are lacking so far. This study aimed to evaluate the association between CRP measured in dried blood spots (DBS CRP) and in saliva (sCRP), two less invasive alternatives to venipuncture, in 12- to 14-year-old adolescents. To evaluate the validity of both measurements in the context of biobehavioral studies, the potential of DBS CRP and sCRP to discriminate between defined BMI subgroups was assessed.

Materials and Methods

CRP levels in DBS and saliva collected from 87 healthy adolescents (M = 13.25 years, SD = 0.30, 51.7% females) were determined using high sensitive CRP ELISA for serum and salivary CRP ELISA, respectively. Characteristics and correlation of both measurements were assessed for the total sample and for three subgroups classified by BMI percentile ranges (A: ≤ 25; B: 26–74; C: ≥ 75).

Results

In the total sample, DBS CRP and sCRP were significantly associated (r = 0.59, p < 0.001). Splitting the sample into BMI-dependent subgroups revealed similarly strong associations of DBS CRP with sCRP for all three groups (A: r = 0.51; B: r = 0.61; C: r = 0.53). However, comparing the mean CRP values per BMI subgroup, one-way ANOVA reported significant differences for DBS CRP, but not for sCRP mean values.

Conclusions

The significant correlation of DBS CRP with sCRP was independent of the investigated BMI range groups, yet BMI-dependent distinction was only provided by DBS CRP mean values. Overall, our results suggest that DBS CRP is likely to reflect systemic inflammation more precisely. Salivary CRP can be alternatively determined in studies with adolescents when conditions require it, given the oral health status is assessed. Considering that DBS CRP and sCRP share only 35% of common variance, further studies should examine their specific validity.

Comparative evaluation of salivary and serum high-sensitive C-reactive protein in acute myocardial infarction

Aim:

The aim of this study is to comparatively evaluate the serum and salivary high-sensitive C-reactive protein (hs-CRP) in patients with acute myocardial infarction (MI).

Subjects and Methods:

The study group consisted of 60 patients of whom 30 were MI patients and 30 were controls. Serum hs-CRP was assessed using particle-enhanced immunoturbidimetric assay. Saliva hs-CRP is determined using a microplate reader cum UV photospectrometer from BMG.

Results:

In this study, levels of both serum and salivary hs-CRP in control and MI patients showed a positive correlation. Saliva can be used as an alternative biofluid to determine hs-CRP in MI patients.

Conclusion:

Saliva can be used as a alternative biofluid to determine the risk as well as to determine prognosis in acute myocardial infarction.

Salivary C-Reactive Protein and Mean Platelet Volume in the Diagnosis and Follow-Up of Community-Acquired Pneumonia in Infants

Background: Community-acquired pneumonia (CAP) in infants is a major cause of morbidity and mortality, especially in developing countries. Increased salivary C-reactive protein (CRP) levels have been demonstrated in neonatal pneumonia and other diseases. We investigated the applicability of CRP and mean platelet volume (MPV) in the diagnosis and follow-up of CAP in infants. Methods: This prospective observational study included 45 infants admitted for CAP. We measured serum and salivary CRP levels via ELISA, while MPV was measured using an automated blood cell counter. Results: Both salivary and serum CRP values were significantly different in the studied population between admission and follow-up (P = 0.001 and P < 0.0001, respectively). The same was observed for MPV (P < 0.0001). We found significant positive correlations between serum and salivary CRP (r = 0.652, P < 0.0001) and between serum CRP and MPV (r = 0.495, P = 0.001), as well as between salivary CRP and MPV (r = 0.439, P = 0.003). Receiver operating curve analysis showed that salivary CRP at a cutoff value of 3.2 ng/L had a sensitivity of 97.2% and specificity of 90%, while MPV at a cutoff value of 8.4 fL showed 91% sensitivity and 90% specificity. Conclusions: The present study showed that both salivary CRP and MPV are reliable diagnostic markers of CAP in infants.

Fluorescent Biosensors Based on Silicon Nanowires

Nanostructures are arising as novel biosensing platforms promising to surpass current performance in terms of sensitivity, selectivity, and affordability of standard approaches. However, for several nanosensors, the material and synthesis used make the industrial transfer of such technologies complex. Silicon nanowires (NWs) are compatible with Si-based flat architecture fabrication and arise as a hopeful solution to couple their interesting physical properties and surface-to-volume ratio to an easy commercial transfer. Among all the transduction methods, fluorescent probes and sensors emerge as some of the most used approaches thanks to their easy data interpretation, measure affordability, and real-time in situ analysis. In fluorescent sensors, Si NWs are employed as substrate and coupled with several fluorophores, NWs can be used as quenchers in stem-loop configuration, and have recently been used for direct fluorescent sensing. In this review, an overview on fluorescent sensors based on Si NWs is presented, analyzing the literature of the field and highlighting the advantages and drawbacks for each strategy.

Synthesis and grafting of diazonium tosylates for thermoplastic electrode immunosensors

For electrochemical immunosensors, inexpensive electrodes with fast redox kinetics, and simple stable methods of electrode functionalization are vital. However, many inexpensive and easy to fabricate electrodes suffer from poor redox kinetics, and functionalization can often be difficult and/or unstable. Diazonium tosylates are particularly stable soluble salts that can be useful for electrode functionalization. Recently developed thermoplastic electrodes (TPEs) have been inexpensive, moldable, and highly electroactive carbon composite materials. Herein, the synthesis and grafting of diazonium tosylate salts were optimized for modification of TPEs and used to develop the first TPE immunosensors. With diazonium tosylates, TPEs were amine functionalized either directly through grafting of p-aminophenyl diazonium salt or indirectly through grafting p-nitrophenyl diazonium salt followed by electrochemical reduction to an amine. Diazonium tosylates were synthesized in situ as a paste in 6 min. Once the reaction paste was spread over the electrodes, near monolayer coverage (1.0 ± 0.2 nmol cm-2) was achieved for p-nitrophenyl diazonium salt within 5 min. Amine functionalized electrodes were conjugated to C-reactive protein (CRP) antibodies. Antibody-modified TPEs were applied for the sensitive detection of CRP, a biomarker of cardiovascular disease using electrochemical enzyme-linked immunosorbent assays (ELISA). LODs were determined to be 2 ng mL-1 in buffer, with high selectivity against interfering species for both functionalization methods. The direct p-aminophenyl modification method had the highest sensitivity to CRP and was further tested in spiked serum with an LOD of 10 ng mL-1. This low-cost and robust TPE immunosensor platform can be easily adapted for other analytes and multiplexed detection.

Diagnostics for SARS-CoV-2 infections

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to nearly every corner of the globe, causing societal instability. The resultant coronavirus disease 2019 (COVID-19) leads to fever, sore throat, cough, chest and muscle pain, dyspnoea, confusion, anosmia, ageusia and headache. These can progress to life-threatening respiratory insufficiency, also affecting the heart, kidney, liver and nervous systems. The diagnosis of SARS-CoV-2 infection is often confused with that of influenza and seasonal upper respiratory tract viral infections. Due to available treatment strategies and required containments, rapid diagnosis is mandated. This Review brings clarity to the rapidly growing body of available and in-development diagnostic tests, including nanomaterial-based tools. It serves as a resource guide for scientists, physicians, students and the public at large.

Biosensing platforms based on silicon nanostructures: A critical review

Biosensors are revolutionizing the health-care systems worldwide, permitting to survey several diseases, even at their early stage, by using different biomolecules such as proteins, DNA, and other biomarkers. However, these sensing approaches are still scarcely diffused outside the specialized medical and research facilities. Silicon is the undiscussed leader of the whole microelectronics industry, and novel sensors based on this material may completely change the health-care scenario. In this review, we will show how novel sensing platforms based on Si nanostructures may have a disruptive impact on applications with a real commercial transfer. A critical study for the main Si-based biosensors is herein presented with a comparison of their advantages and drawbacks. The most appealing sensing devices are discussed, starting from electronic transducers, with Si nanowires field-effect transistor (FET) and porous Si, to their optical alternatives, such as effective optical thickness porous silicon, photonic crystals, luminescent Si quantum dots, and finally luminescent Si NWs. All these sensors are investigated in terms of working principle, sensitivity, and selectivity with a specific focus on the possibility of their industrial transfer, and which ones may be preferred for a medical device.

Rapid and Selective Biomarker Detection with Conductometric Sensors

The biomarker detection in human body fluids is crucial as biomarkers are important in diagnosing diseases. Conventional invasive techniques for biomarker detection are associated with infection, tissue damage, and discomfort. Non-invasive devices are an attractive alternative. Here, metal oxide (oxygen-deficient zinc oxide, ZnO) based conductometric sensors with two-terminal electrodes for rapid detection of biomarkers in real-time, are presented. This platform can be engineered for non-invasive, sensitive, and on-demand selective detection of biomarkers based on surface functionalization. The three novelties in this biosensing technique include an on-demand target selection device platform, short (<10 min) incubation times, and real-time monitoring of the biomarker of interest by electrical (resistance change) measurements. Cardiac inflammatory biomarkers interleukin 6 (IL-6) and C-reactive protein (CRP) are used as the model antigens. The devices can detect 100× lower concentration of IL-6 than healthy levels in human saliva and sweat and 1000× and ≈50× lower CRP concentrations than healthy levels in human saliva and sweat, respectively. The devices show high selectivity for IL-6 and CRP antigens when tested with a mixture of biomarkers. This sensor platform can be extended to selective measurements for viruses or DNA screening, which enables a new category of compact and rapid point-of-care medical devices.

Elderly Subjects Supplemented with L-Glutamine Shows an Improvement of Mucosal Immunity in the Upper Airways in Response to Influenza Virus Vaccination

BACKGROUND

Although glutamine is able to improve the immune response, its action in the upper airway immunity against the influenza virus vaccine remains unclear. Therefore, we aimed to evaluate the L-glutamine supplementation effect on the mucosal immune/inflammatory response of elderly subjects vaccinated against the influenza virus.

METHODS

Saliva sampling from 83 physically active elderly volunteers were collected pre- and 30 days after influenza virus vaccination and supplementation with L-glutamine (Gln, n = 42) or placebo (PL, n = 41).

RESULTS

Gln group showed higher salivary levels of interleukin (IL)-17, total secretory immunoglobulin A (SIgA), and specific-SIgA post-vaccination than values found pre-vaccination and in the PL group post-vaccination. Whereas higher salivary levels of IL-6 and IL-10 were observed post-vaccination in the Gln group, IL-37 levels were lower post-vaccination in both groups than the values pre-vaccination. Tumor necrosis factor (TNF)-α levels were unchanged. Positive correlations between IL-6 and IL-10 were found in all volunteer groups pre- and post-vaccination and also between IL-17 and IL-6 or IL-10 in the Gln group post-vaccination. A negative correlation between IL-37 and IL-10 was found pre- and post-vaccination in the PL group.

CONCLUSION

Gln supplementation was able to modulate salivary cytokine profile and increase SIgA levels, both total and specific to the influenza virus vaccine, in physically active elderly subjects.

Pronounced Diurnal Pattern of Salivary C-Reactive Protein (CRP) With Modest Associations to Circulating CRP Levels

C-reactive protein (CRP), a humoral component of the innate immune system with important functions in host-defense, is extensively used as a sensitive biomarker of systemic inflammation. During inflammation, hepatocyte-derived CRP rises dramatically in the blood due to increased interleukin-6 (IL-6) levels. Reliable detection of CRP in saliva, instead of blood, would offer advantages regarding sampling procedure and availability but using saliva as a diagnostic body fluid comes with challenges. The aims of this study were to evaluate associations between salivary CRP, total protein levels in saliva and serum CRP. Furthermore, we examined associations with plasma IL-6, body mass index (BMI), tobacco smoking and age. Salivary CRP was investigated by ELISA in 107 middle-aged participants from the general population. We employed spectrophotometric determination of total protein levels. Correlation analyses were used for associations of salivary CRP with serum CRP (turbidimetry), plasma IL-6 (Luminex^®), BMI and smoking habits. Salivary median CRP was 68% higher (p=0.009), and total protein levels were 167% higher (p<0.0001), in morning compared to evening saliva. The correlation coefficients between serum and salivary CRP were low to moderate, but stronger for evening than morning saliva. Plasma IL-6 correlated significantly with serum CRP (r_s=0.41, p<0.01), but not with morning or evening salivary CRP. Non-smokers showed 103% higher salivary CRP levels (p=0.015), whereas serum CRP was independent of smoking status. As opposed to CRP in serum, salivary CRP was not associated with BMI. Salivary CRP was 90% higher among the age interval 60–69 years compared to subjects aged 45–59 (p=0.02) while serum CRP levels did not differ between the age groups. In conclusion, CRP in saliva did not straightforwardly reflect serum concentrations. This raises questions regarding adequate reflection of biological events. The pronounced diurnal salivary CRP pattern accentuates the importance of standardizing the time-point of sampling.

C-reactive protein in saliva and dried blood spot as markers of stress reactivity in healthy African-Americans

Aim: Noninvasive assessments of C-reactive protein (CRP) in stress contexts have seldom been compared. This study evaluated CRP response to acute social stress as measured in saliva and dried blood spot (DBS). Materials & methods: African-Americans (N = 118; mean age = 32 years) participated in a laboratory-based social-evaluative stressor task. Six saliva samples taken before, during and after were assayed for salivary CRP. DBS measurements of CRP were taken alongside saliva at the first and last collection. Results: Salivary and DBS CRP were modestly positively associated with one another at baseline, and only salivary CRP increased in response to the stressor task. Conclusion: Noninvasive measures of CRP reactivity may be only moderately related to one another in stress reactivity contexts.

Saliva as a diagnostic tool for dental caries, periodontal disease and cancer: is there a need for more biomarkers?

Introduction: A biomarker is a biological indicator of normal or pathogenic processes. Identification of biomarkers is useful for the prevention, diagnosis and prognosis of diseases as well as for monitoring the progression of pathological disorders. Several types of molecules present in biological fluids can act as biomarkers such as DNA, coding and non-coding RNA, lipids, metabolites, proteins and even microbes. In this context, saliva emerges as a useful diagnostic tool for the detection of biomarkers involved with oral and systemic diseases, since it reflects the pathophysiological conditions of the organism and allows early, rapid, practical and noninvasive detection of biomarkers.Areas covered: This review discusses the properties of saliva as a diagnostic tool and addresses the main identified biomarkers related to dental caries, periodontal disease, head and neck cancer and other types of cancer of considerable incidence among the world population.Expert commentary: Despite extensive efforts which have been directed toward the identification of one or a combination of biomarkers with good predictive values for the early detection of dental caries, periodontal disease and cancer, these biomarkers still need validation before chairside point-of-care devices can be widely used in the clinic.

The potential prognostic utility of salivary galectin-3 concentrations in heart failure

BACKGROUND

Patients with HF are at a higher risk of rehospitalisation and, as such, significant costs to our healthcare system. A non-invasive method to collect body fluids and measure Gal-3 could improve the current management of HF. In this study, we investigated the potential prognostic utility of salivary Galectin-3 (Gal-3) in patients with heart failure (HF).

METHODS

We collected saliva samples from patients with HF (n = 105) either at hospital discharge or during routine clinical visits. Gal-3 concentrations in saliva samples were measured by ELISA. The Kaplan-Meier survival curve analysis and Cox proportional regression model were used to determine the potential prognostic utility of salivary Gal-3 concentrations.

RESULTS

The primary end point was either cardiovascular death or hospitalisation. Salivary Gal-3 concentrations were significantly higher (p < 0.05) in patients with HF who subsequently experienced the primary endpoint compared to those who did not. HF patients with salivary Gal-3 concentrations > 172.58 ng/mL had a significantly (p < 0.05) higher cumulative risk of the primary endpoint compared to those with lower salivary Gal-3 concentrations. In patients with HF, salivary Gal-3 concentration was a predictor of the primary endpoint even after adjusting for other covariates.

CONCLUSIONS

In our pilot study, HF patients with salivary Gal-3 concentrations of > 172.58 ng/mL demonstrated a higher cumulative risk of the primary outcome compared to those with lower Gal-3 levels, even after adjusting for other variables. Confirming our findings in a larger multi-centre clinical trial in the future would enable salivary Gal-3 measurements to form part of routine management for patients with HF.

Acute phase proteins, saliva and education in laboratory science: an update and some reflections

This manuscript provides updated knowledge and some ideas and reflections about three areas which are currently of interest in the field of the animal laboratory science. These areas are the study of acute phase proteins (APPs) as biomarkers of inflammation, the use of saliva as a non-invasive sample for analyte measurements, and the development of education in the field of laboratory medicine. In the APPs, a seven-point plan for their interpretation in all veterinary species containing updated knowledge and future perspectives is described. Regarding the saliva, general concepts, examples of practical applications and the limitations and points to improve for the use of this fluid are explained. Finally, the recent evolution, current situation and possible ideas for future development of education in this field are commented. In addition to review the knowledge in these three specific areas, this report can help to provide a wide vision of the potential and future perspectives in veterinary laboratory science.

Isolation and Quantification of MicroRNAs from Human Saliva

Oral premalignant disorders (OPMD) have relatively high malignant transformation rates to Oral Cancers (OC). Oral carcinogenesis is a multistep process that originates as epithelial hyperplasia followed by epithelial dysplasia, leading to fully malignant phenotypes. Early detection can be lifesaving but is currently not possible due to the lack of early diagnostic tools. The current diagnostic methods such as biopsy sampling, tumor tissue staining, and imaging techniques require skilled personnel and are invasive, painful, time-consuming, and expensive. Saliva has gained momentum as the diagnostic fluid of the future due to its noninvasive nature, ease of sampling, multiple samples can be collected with ease and more importantly does not require skilled personnel. The use of saliva in cancer diagnostics is an emerging and an expanding field. MicroRNA (miRNA) play a role in cancer initiation and progression and the expression changes of miRNA have been investigated as a potential biomarker in cancer studies. In this chapter, we describe a robust and cost-effective protocol to isolate and enrich miRNA from saliva samples. Profiling miRNAs in saliva samples can form part of the clinical management of OPMD and OC patients in the future.

A pilot study to profile salivary angiogenic factors to detect head and neck cancers

BACKGROUND

Early diagnosis of head and neck squamous cell carcinoma (HNSCCs) is an appealing way to increase survival rates in these patients as well as to improve quality of life post-surgery. Angiogenesis is a hallmark of tumor initiation and progression. We have investigated a panel of angiogenic factors in saliva samples collected from HNSCC patients and controls using the Bio-Plex ProTM assays.

METHODS

We have identified a panel of five angiogenic proteins (sEGFR, HGF, sHER2, sIL-6Ra and PECAM-1) to be elevated in the saliva samples collected from HNSCC patients (n = 58) compared to a control cohort (n = 8 smokers and n = 30 non-smokers).

RESULTS

High positive correlations were observed between the following sets of salivary proteins; sEGFR:sHER2, sEGFR:HGF, sEGFR:sIL-6Rα, sHER2:HGF and sHER2:sIL6Ra. A moderate positive correlation was seen between FGF-basic and sEGFR.

CONCLUSION

We have shown that angiogenic factor levels in saliva can be used as a potential diagnostic biomarker panel in HNSCC.

Realising the Potential of Urine and Saliva as Diagnostic Tools in Sport and Exercise Medicine

Accurate monitoring of homeostatic perturbations following various psychophysiological stressors is essential in sports and exercise medicine. Various biomarkers are routinely used as monitoring tools in both clinical and elite sport settings. Blood collection and muscle biopsies, both invasive in nature, are considered the gold standard for the analysis of these biomarkers in exercise science. Exploring non-invasive methods of collecting and analysing biomarkers that are capable of providing accurate information regarding exercise-induced physiological and psychological stress is of obvious practical importance. This review describes the potential benefits, and the limitations, of using saliva and urine to ascertain biomarkers capable of identifying important stressors that are routinely encountered before, during, or after intense or unaccustomed exercise, competition, over-training, and inappropriate recovery. In particular, we focus on urinary and saliva biomarkers that have previously been used to monitor muscle damage, inflammation, cardiovascular stress, oxidative stress, hydration status, and brain distress. Evidence is provided from a range of empirical studies suggesting that urine and saliva are both capable of identifying various stressors. Although additional research regarding the efficacy of using urine and/or saliva to indicate the severity of exercise-induced psychophysiological stress is required, it is likely that these non-invasive biomarkers will represent "the future" in sports and exercise medicine.

Development of Paper-Based Analytical Devices for Minimizing the Viscosity Effect in Human Saliva

Rationale: Saliva as a sample matrix is rapidly gaining interest for disease diagnosis and point-of-care assays because it is easy to collect (non-invasive) and contains many health-related biomarkers. However, saliva poses particular problems relative to more common urine and blood matrices, which includes low analyte concentrations, lack of understanding of biomolecule transportation and inherent viscosity variability in human samples. While several studies have sought to improve assay sensitivity, few have addressed sample viscosity specifically. The goal of this study is to minimize the effect of sample viscosity on paper-based analytical devices (PADs) for the measurement of pH and nitrite in human saliva. Methods: PADs were used to measure salivary pH from 5.0 to 10.0 with a universal indicator consisting of chlorophenol red, phenol red and phenolphthalein. Nitrite determination was performed using the Griess reaction. Artificial saliva with viscosity values between 1.54 and 5.10 mPa∙s was tested on the proposed PAD. To ensure the proposed PADs can be tailored for use in-field analysis, the devices were shipped to Australia and tested with human specimens. Results: Initial experiments showed that viscosity had a significant impact on the calibration curve for nitrite; however, a more consistent curve could be generated when buffer was added after the sample, irrespective of sample viscosity. The linear range for nitrite detection was 0.1 to 2.4 mg/dL using the improved method. The nitrite measurement in artificial saliva also showed a good correlation with the standard spectrophotometry method (p=0.8484, paired sample t-test, n=20). Measured pH values from samples with varying viscosities correlated well with the results from our pH meter. Conclusions: The inherent variation of salivary viscosity that impacts nitrite and pH results can be addressed using a simple washing step on the PAD without the need for complex procedures.

Synergistic Use of Gold Nanoparticles (AuNPs) and "Capillary Enzyme-Linked Immunosorbent Assay (ELISA)" for High Sensitivity and Fast Assays

Using gold nanoparticles (AuNPs) on "capillary enzyme-linked immunosorbent assay (ELISA)", we produced highly sensitive and rapid assays, which are the major attributes for point-of-care applications. First, in order to understand the size effect of AuNPs, AuNPs of varying diameters (5 nm, 10 nm, 15 nm, 20 nm, 30 nm, and 50 nm) conjugated with Horseradish Peroxidase (HRP)-labeled anti-C reactive protein (antiCRP) (AuNP•antiCRP-HRP) were used for well-plate ELISA. AuNP of 10 nm produced the largest optical density, enabling detection of 0.1 ng/mL of CRP with only 30 s of incubation, in contrast to 10 ng/mL for the ELISA run in the absence of AuNP. Then, AuNP of 10 nm conjugated with antiCRP-HRP (AuNP•antiCRP-HRP) was used for "capillary ELISA" to detect as low as 0.1 ng/mL of CRP. Also, kinetic study on both 96-well plates and in a capillary tube using antiCRP-HRP or AuNP•antiCRP-HRP showed a synergistic effect between AuNP and the capillary system, in which the fastest assay was observed from the "AuNP capillary ELISA", with its maximum absorbance reaching 2.5 min, while the slowest was the typical well-plate ELISA with its maximum absorbance reaching in 13.5 min.

Identification and Validation of a Salivary Protein Panel to Detect Heart Failure Early

BACKGROUND

Over 26 million people suffer from heart failure (HF) globally. Current diagnosis of HF relies on clinical evaluation, blood assays and imaging techniques. Our aim is to develop a diagnostic assay to detect HF in at risk individuals within the community using human saliva as a medium, potentially leading to a simple, safe early warning system.

METHODS

Saliva samples were collected from healthy controls (n=36) and HF patients (n=75). Salivary proteome profiles were analysed by Sequential Window Acquisition of All Theoretical fragment ion spectra - Mass Spectrometry (SWATH-MS). A total of 738 proteins were quantified and 177 proteins demonstrated significant differences between HF patients and healthy controls. Candidate biomarkers were chosen based on their abundance and difference between the two cohorts. A multi-protein panel was developed using logistic regression analysis. The diagnostic performance of the multi-protein panel was assessed using receiver operative characteristic curves. The candidate proteins were further confirmed, using western blot analysis, and validated technically, using an independent biological cohort.

RESULTS

A group of six proteins were chosen in the discovery phase as potential candidates based on their differences in the abundance between the two cohorts. During the validation phase, two of the proteins were not detected with western blotting and as such were removed. The final panel consists of four proteins with sensitivity of 83.3%, specificity of 62.5% with an area under ROC curve of 0.78 in discriminating healthy controls from NYHA class I/II HF patients, and was validated in a second independent cohort study.

CONCLUSION

Analysis of salivary proteome using SWATH-MS revealed novel HF-specific protein candidates yielding high diagnostic performance. A multi-centre longitudinal clinical trial will be the next step before clinical implementation of this panel.

Saliva Liquid Biopsy for Point-of-Care Applications

Saliva is a non-invasive biofluid, which is easy to collect, transport, and store. Because of its accessibility and connection to systemic diseases, saliva is one of the best candidates for the advancement of point-of-care medicine, where individuals are able to easily monitor their health status by using portable convenient tools such as smartphones. There are a variety of scenarios with which saliva can be used: studies have been conducted on using saliva to measure stress hormones, enzyme levels, developmental disease biomarkers, and even cancer mutations. If validated biomarkers were combined with high-quality detection tools, saliva would open up a new frontier in high-quality healthcare, allowing physicians and patients to work together for real-time health monitoring and high-impact personalized preventative medicine. One of the most exciting emerging frontiers of saliva is liquid biopsy, which is a non-invasive means to assess the presence and characteristics of cancer in a patient. This article will review current basic knowledge of biomarkers, review their relation to different diseases and conditions, and explore liquid biopsy for point-of-care applications.

Salivary Biomarkers, Oral Inflammation, and Functional Status in Patients With Heart Failure

AIMS

To describe correlations and agreement between salivary and serum B-type natriuretic peptide (BNP), C-reactive protein (CRP), interleukin (IL)-6, and IL-10 and determine which biomarkers predict worse functional class in patients with heart failure (HF).

METHODS

Serum and saliva were collected from 75 hospitalized patients with HF (57 ± 12 years, 43% female, New York Heart Association [NYHA] Classes I [4%], II [43%], and III [53%]). Oral inflammation was rated as good, fair, or poor. Spearman's ρ and Bland-Altman were used to determine correlations and agreement of the salivary and serum forms of each biomarker. Logistic regressions were used to determine which biomarkers predicted worse NYHA functional class, controlling for depression, body mass index, smoking, and oral inflammation.

RESULTS

Median biomarker concentrations were as follows: BNP (serum 361 pg/ml, saliva 9 pg/ml), CRP (serum 13 ng/ml, saliva 25.6 ng/ml), IL-6 (serum 19.3 pg/ml, saliva 10.5 pg/ml), and IL-10 (serum 64.1 pg/ml, saliva 4.7 pg/ml). There was a moderate-to-strong correlation for serum-salivary CRP, weak correlation for serum-salivary IL-6, and no correlations for serum-salivary BNP and IL-10. The Bland-Altman test showed good salivary-serum agreement for all biomarkers, but as serum concentrations rose, salivary measures underestimated serum levels. Visible oral inflammation was the only predictor of worse NYHA class.

Partnered sexual activity moderates menstrual cycle-related changes in inflammation markers in healthy women: an exploratory observational study

OBJECTIVE

To examine differences in inflammation markers in sexually active versus abstinent women and observe changes in inflammation markers across the menstrual cycle. Cycle-related immune fluctuations may have evolved to reduce interference with conception. If so, reproductively active (i.e., sexually active) women should show the most variability in cytokine expression.

DESIGN

Participants provided serum samples at menses and ovulation (from which cytokines were assayed) and saliva samples at menses and during follicular, ovulation, and luteal phases (from which C-reactive protein [CRP] was assayed). Participants self-reported intercourse frequency during the study.

SETTING

Academic research laboratory.

PATIENT(S)

Thirty-two healthy, naturally cycling premenopausal women (sexually active, n = 15; abstinent, n = 17).

INTERVENTION(S)

Observational study.

MAIN OUTCOME MEASURE(S)

Levels of proinflammatory cytokines (interleukin-6 [IL-6], interferon γ [IFN-γ], tumor necrosis factor-α [TNF-α]), an anti-inflammatory cytokine (interleukin-4 [IL-4]), and a marker of total inflammation (CRP).

RESULT(S)

Sexually active women had higher levels of all of the immune markers measured, including both pro- and anti-inflammatory cytokines, than abstinent women. Relative to sexually active women, abstinent women had less change across the menstrual cycle in levels of CRP. Among sexually active women, higher intercourse frequency predicted greater midcycle decreases in CRP, IL-6, and IFN-γ and midcycle increases in IL-4.

CONCLUSION(S)

Sexual activity may stimulate a complex interaction between pro- and anti-inflammatory cytokines that subsequently drives midcycle declines in inflammation.

Variation of Human Salivary O-Glycome

The study of saliva O-glycosylation is receiving increasing attention due to the potential of glycans for disease biomarkers, but also due to easy access and non-invasive collection of saliva as biological fluid. Saliva is rich in glycoproteins which are secreted from the bloodstream or produced by salivary glands. Mucins, which are highly O-glycosylated proteins, are particularly abundant in human saliva. Their glycosylation is associated with blood group and secretor status, and represents a reservoir of potential disease biomarkers. This study aims to analyse and compare O-glycans released from whole human mouth saliva collected 3 times a day from a healthy individual over a 5 days period. O-linked glycans were released by hydrazinolysis, labelled with procainamide and analysed by ultra-high performance liquid chromatography with fluorescence detection (UHPLC-FLR) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). The sample preparation method showed excellent reproducibility and can therefore be used for biomarker discovery. Our data demonstrates that the O-glycosylation in human saliva changes significantly during the day. These changes may be related to changes in the salivary concentrations of specific proteins.

Salivary epigenetic biomarkers in head and neck squamous cell carcinomas

The early detection of head and neck squamous cell carcinoma (HNSCC) continues to be a challenge to the clinician. Saliva as a diagnostic medium carries significant advantages including its close proximity to the region of interest, ease of collection and noninvasive nature. While the identification of biomarkers continues to carry significant diagnostic and prognostic utility in HNSCC, epigenetic alterations present a novel opportunity to serve this purpose. With the developments of novel and innovative technologies, epigenetic alterations are now emerging as attractive candidates in HNSCC. As such, this review will focus on two commonly aberrant epigenetic alterations: DNA methylation and microRNA expression in HNSCC and their potential clinical utility. Identification and validation of these salivary epigenetic biomarkers would not only enable early diagnosis but will also facilitate in the clinical management.

The current status of heart failure diagnostic biomarkers

Heart failure (HF) affects approximately 23 million individuals worldwide and this number is increasing, due to an aging and growing population. Early detection of HF is crucial in the management of this debilitating disease. Current diagnostic methods for HF rely heavily on clinical imaging techniques and blood analysis, which makes them less than ideal for population-based screening purposes. Studies focusing on developing novel biomarkers for HF have utilized various techniques and biological fluids, including urine and saliva. Promising results from these studies imply that these body fluids can be used in evaluating the clinical manifestation of HF and will one day be integrated into a clinical workflow and facilitate HF management.

Salivary Heparanase Level Is a Potential Biomarker to Diagnose and Prognose the Malignant Salivary Gland Tumor

Background

Upregulation of heparanase has been reported in an increasing number of human cancer tissues. However, the level of salivary heparanase and its clinical significance in patients with salivary gland tumors remain unclear.

Methods

Salivary heparanase levels in patients with salivary gland tumors were detected using enzyme-linked immunosorbent assays (ELISAs) and the clinical significance was evaluated by analyzing the correlations among salivary heparanase levels, clinicopathological parameters, and clinical outcomes.

Results

The levels of salivary heparanase were significantly higher in patients with malignant salivary gland tumors than in benign tumors and normal controls (P<0.0001). High salivary heparanase levels were positively correlated with increased lymph node metastasis (P = 0.0235) and poorer tumor node metastasis stage (TNM) (P = 0.0183). Survival analyses revealed that high salivary heparanase levels were associated with worse overall survival (P = 0.0023) and disease-free survival (DFS) (P = 0.0025).

Conclusions

The study shows that salivary heparanase levels, as detected by the ELISAs, can be used to diagnose and provide an accurate prognosis for malignant salivary gland tumors. Salivary heparanase level was an independent predictor in patients with malignant salivary gland tumors.