Biochemistry of human alpha amylase isoenzymes

A comprehensive in-vitro/in-vivo screening toolbox for the elucidation of glucose homeostasis modulating properties of plant extracts (from roots) and its bioactives

Plant extracts are increasingly recognized for their potential in modulating (postprandial) blood glucose levels. In this context, root extracts are of particular interest due to their high concentrations and often unique spectrum of plant bioactives. To identify new plant species with potential glucose-lowering activity, simple and robust methodologies are often required. For this narrative review, literature was sourced from scientific databases (primarily PubMed) in the period from June 2022 to January 2024. The regulatory targets of glucose homeostasis that could be modulated by bioactive plant compounds were used as search terms, either alone or in combination with the keyword "root extract". As a result, we present a comprehensive methodological toolbox for studying the glucose homeostasis modulating properties of plant extracts and its constituents. The described assays encompass in-vitro investigations involving enzyme inhibition (α-amylase, α-glucosidase, dipeptidyl peptidase 4), assessment of sodium-dependent glucose transporter 1 activity, and evaluation of glucose transporter 4 translocation. Furthermore, we describe a patch-clamp technique to assess the impact of extracts on KATP channels. While validating in-vitro findings in living organisms is imperative, we introduce two screenable in-vivo models (the hen's egg test and Drosophila melanogaster). Given that evaluation of the bioactivity of plant extracts in rodents and humans represents the current gold standard, we include approaches addressing this aspect. In summary, this review offers a systematic guide for screening plant extracts regarding their influence on key regulatory elements of glucose homeostasis, culminating in the assessment of their potential efficacy in-vivo. Moreover, application of the presented toolbox might contribute to further close the knowledge gap on the precise mechanisms of action of plant-derived compounds.

Probing the salivary proteome for prognostic biomarkers in response to non-surgical periodontal therapy

AIM

This prospective study investigated the salivary proteome before and after periodontal therapy.

MATERIALS AND METHODS

Ten systemically healthy, non-smoking, stage III, grade C periodontitis patients underwent non-surgical periodontal treatment. Full-mouth periodontal parameters were measured, and saliva (n = 30) collected pre- (T0), and one (T1) and six (T6) months post-treatment. The proteome was investigated by label-free quantitative proteomics. Protein expression changes were modelled over time, with significant protein regulation considered at false discovery rate <0.05.

RESULTS

Treatment significantly reduced bleeding scores, percentages of sites with pocket depth ≥5 mm, plaque and gingival indexes. One thousand seven hundred and thirteen proteins were identified and 838 proteins (human = 757, bacterial = 81) quantified (≥2 peptides). At T1, 80 (T1 vs. T0: 60↑:20↓), and at T6, 118 human proteins (T6 vs. T0: 67↑:51↓) were regulated. The salivary proteome at T6 versus T1 remained stable. Highest protein activity post- versus pre-treatment was observed for cellular movement and inflammatory response. The small proline-rich protein 3 (T1 vs. T0: 5.4-fold↑) and lymphocyte-specific protein 1 (T6 vs. T0: 4.6-fold↓) were the top regulated human proteins. Proteins from Neisseria mucosa and Treponema socranskii (T1 vs. T0: 8.0-fold↓, 4.9-fold↓) were down-regulated.

CONCLUSIONS

Periodontal treatment reduced clinical disease parameters and these changes were reflected in the salivary proteome. This underscores the potential of utilizing saliva biomarkers as prognostic tools for monitoring treatment outcomes.

Salivary α-amylase as a marker of sleep disorders: A theoretical review

Sleep disorders are commonplace in our modern societies. Specialized hospital departments are generally overloaded, and sleep assessment is an expensive process in terms of equipment, human resources, and time. Biomarkers would usefully complement current measures in the screening and follow-up of sleep disorders and their daytime repercussions. Among salivary markers, a growing body of literature suggests that salivary α-amylase (sAA) may be a cross-species marker of sleep debt. However, there is no consensus as to the direction of variation in sAA with sleep disorders. Herein, after describing the mechanisms of sAA secretion and its relationship with stress, studies assessing the relationship between sAA and sleep parameters are reviewed. Finally, the influence of confounding factors is discussed, along with methodological considerations, to better understand the fluctuations in sAA and facilitate future studies in the field.

Salivary and serum biomarkers to evaluate psychological disorders in burning mouth syndrome: A systematic review and meta-analysis

BACKGROUND

Burning mouth syndrome is a chronic pain syndrome mainly characterized by an intensive burning sensation of tongue. Previous studies have suggested that saliva/serum biomarkers in burning mouth syndrome might be associated with psychological disorders. The aim of systematic review was to observe whether the biomarkers in serum/saliva could be an alternative method to evaluate the psychological disorders in patients with burning mouth syndrome.

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane Library databases were searched for papers published up to March 15, 2023. Risk of bias was measured by using the Newcastle-Ottawa Scale. RevMan was used for meta-analysis.

RESULTS

A total of 467 articles were screened, which of 12 studies were included. These studies collected 43 different biomarkers in saliva and 35 in serum. Of these biomarkers, only three (cortisol, α-amylase, and IL-6) were analyzed in two or more studies. Only salivary cortisol levels were significantly higher in the patient group compared to the controls (Mean Difference = 1.39; 95% CI [0.80-1.97]; p < 0.001). Moreover, cortisol might be relevant to psychological scores, especially anxiety.

CONCLUSION

Different papers have investigated salivary and serum biomarkers in burning mouth syndrome patients with controversial results. This meta-analysis showed that cortisol levels in saliva may be a potential biomarker to assess the psychological disorders in burning mouth syndrome patients.

Crawling toward obsolescence: The extended lifespan of amylase for pancreatitis

The correlation between hyperamylasemia and acute pancreatitis was discovered in 1929, yet another test, lipase, was shown to provide better diagnostic performance in the late 1980s and early 1990s. Subsequent studies demonstrated co-ordering amylase with lipase did not provide additional benefit, only added cost. We sought to investigate the impact of studies advocating for the obsolescence of amylase on its clinical demand. We reviewed 1.3 million reportable results for amylase over 14 years (2009-2022). The trend in utilization of amylase over this period declined by 66% along a linear trajectory (R2 = 0.97). Despite demand for amylase decreasing by an average of 17,003 tests per year, the last year of the study (2022) recorded over 100,000 results for amylase. By interpolating the decline of amylase until the utilization reached zero, we calculated amylase orders will continue for 6 more years until 2028. Tests for creatinine and lipase changed <3% over the same period. Despite a multitude of studies advocating for the obsolescence of amylase, robust demand continues. Many important clinical guidelines, a source many practicing physicians rely on, have yet to acknowledge the preference for lipase over amylase. They frequently treat the two tests as equivalent, neglecting their head-to-head comparison studies and subsequent studies advocating against co-ordering both tests simultaneously. To expedite the obsolescence of amylase, which we anticipate lasting 46 years in our case study from its initial call for obsolescence to the last orders placed, metrics created specifically to monitor the utilization of unnecessary tests are also needed.

The utility of serum amylase as a prognostic marker in multiple myeloma

Background

Ectopic production of amylase by tumor cells is known since 1951. Elevated amylase in multiple myeloma (MM) was first described in 1988. It has been postulated that translocation of chromosome 1, where amylase gene is situated, is responsible for ectopic production from the malignant plasma cells. Anecdotal reports have shown hyperamylasemia in MM to be associated with extensive bone disease, rapid progression, and shorter survival. Serum amylase estimation is a ubiquitous test. This prospective study was conducted to ascertain the degree of elevated amylase, its clinical utility, and implications in MM patients.

Materials and Methods

In an 18-month period, all consenting patients with newly diagnosed or relapsed MM were tested for serum amylase levels. The study excluded patients with elevated lipase, abnormal creatinine clearance, and evidence of intestinal obstruction or perforation. Patients with amylase value >100 U/L were designated to have "elevated amylase level" for the purpose of this study.

Results

We enrolled 58 patients with MM, of which 29.3% (n = 17) were found to have elevated serum amylase levels. The median age of patients with elevated amylase was 65 years. The male-to-female ratio was 1.9:1. There was no statistical association between age, gender, type of heavy chain class, light chain, or high-risk cytogenetics. Among patients with the International Staging System (ISS), Stages I, II, and III, 20.8% (n = 5), 31.3% (n = 5), and 41.2% (n = 7) were noted to have elevated amylase levels. A statistically significant association was noted between the presence of extramedullary disease (EMD) and elevated amylase level (P = 0.028). Higher mortality (29.4% versus 17%) and shorter mean survival of (30.2 ± 3.3 months versus 51.7 + 4.9 months) were recorded in patients with elevated amylase levels in comparison to those with normal levels.

Conclusions

Elevated serum amylase level in MM is indicative of advanced ISS stage, the presence of EMD, higher risk of mortality, and shorter survival. Serum amylase can be used as a cost-effective tool in myeloma management.

Synthesis of cross-linked polymer based on purified Sterculia foetida L. gum as a potential hemostatic agent

A method for purifying the polysaccharides from Sterculia foetida L. gum was developed. The effects of purifying conditions were also studied. Results have shown that the conditions of pH 0.5, temperature of 80°C, and 2.5-h reaction duration gave the best polysaccharides yield. The mineral content and the molecular weight of the obtained polysaccharides were measured for characterization. The cross-linking of the polysaccharides with citric acid in order to achieve a desired polymer was performed successfully. The obtained polymers under different conditions were evaluated for the potential application as a hemostatic agent, including tests of swelling behavior in different fluids, whole-blood clotting time and enzymatic bio-degradation. Results have shown that the citric acid/polysaccharides ratio of 0.01 produced a comparative yield of polymer flakes with increased swelling properties, as well as shortened in vitro blood clotting time and gradual biodegradability in three experimental days. Therefore, the citric acid/polysaccharides ratio of 0.01 was selected for the subsequent experiment to obtain the polymer after 1.5 h of purification, which gave the best swelling properties, 20 times the initial weight, reduced the whole-blood clotting time by 50% and showed a rapid bio-degradation. The results obtained from this study provide essential knowledge on the research of the use of S. foetida gum polysaccharides as a passive hemostatic agent, thereby extending the potential pharmaceutical applications of natural polysaccharides in Vietnam.

Extracellular Enzyme of Endophytic Fungi Isolated from Ziziphus spina Leaves as Medicinal Plant

Endophytic fungi live inside plants or any part of them without creating any visible pathogenic signs. Endophytic fungi are found within medicinal plants and have shown strong biologic activity, such as anticancer and antioxidant activities, as well as producing extracellular enzymes. In this study, different fungal strains were isolated from the leaves of the medicinal plant Ziziphus spina, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Cladosporium sp., Rhizopus sp., and Mucor sp. Extracellular enzymes have been quantified using agar plate-based methods in which fungi were grown in specified growth media to detect the enzymes produced. The results showed that A. niger has the highest ability to produce amylase, Cladosporium sp. has the highest ability to produce protease and pectinase, Rhizopus and Mucor sp. have the highest ability to produce cellulase, and A. niger and Cladosporium sp. have the same ability to produce lipase and laccase. The ability of medicinal plant endophytic fungi to produce extracellular enzymes has great therapeutic potential in clinical microbiology. Some of the isolates showed great activity in secreting particular enzymes, indicating that the enzymes of these fungi could be used in a variety of applications.

HOIL-1 ubiquitin ligase activity targets unbranched glucosaccharides and is required to prevent polyglucosan accumulation

HOIL-1, a component of the linear ubiquitin chain assembly complex (LUBAC), ubiquitylates serine and threonine residues in proteins by esterification. Here, we report that mice expressing an E3 ligase-inactive HOIL-1[C458S] mutant accumulate polyglucosan in brain, heart and other organs, indicating that HOIL-1's E3 ligase activity is essential to prevent these toxic polysaccharide deposits from accumulating. We found that HOIL-1 monoubiquitylates glycogen and α1:4-linked maltoheptaose in vitro and identify the C6 hydroxyl moiety of glucose as the site of ester-linked ubiquitylation. The monoubiquitylation of maltoheptaose was accelerated > 100-fold by the interaction of Met1-linked or Lys63-linked ubiquitin oligomers with the RBR domain of HOIL-1. HOIL-1 also transferred pre-formed ubiquitin oligomers to maltoheptaose en bloc, producing polyubiquitylated maltoheptaose in one catalytic step. The Sharpin and HOIP components of LUBAC, but not HOIL-1, bound to unbranched and infrequently branched glucose polymers in vitro, but not to highly branched mammalian glycogen, suggesting a potential function in targeting HOIL-1 to unbranched glucosaccharides in cells. We suggest that monoubiquitylation of unbranched glucosaccharides may initiate their removal from cells, preventing precipitation as polyglucosan.

A Comprehensive Insight into Fungal Enzymes: Structure, Classification, and Their Role in Mankind's Challenges

Enzymes have played a crucial role in mankind's challenges to use different types of biological systems for a diversity of applications. They are proteins that break down and convert complicated compounds to produce simple products. Fungal enzymes are compatible, efficient, and proper products for many uses in medicinal requests, industrial processing, bioremediation purposes, and agricultural applications. Fungal enzymes have appropriate stability to give manufactured products suitable shelf life, affordable cost, and approved demands. Fungal enzymes have been used from ancient times to today in many industries, including baking, brewing, cheese making, antibiotics production, and commodities manufacturing, such as linen and leather. Furthermore, they also are used in other fields such as paper production, detergent, the textile industry, and in drinks and food technology in products manufacturing ranging from tea and coffee to fruit juice and wine. Recently, fungi have been used for the production of more than 50% of the needed enzymes. Fungi can produce different types of enzymes extracellularly, which gives a great chance for producing in large amounts with low cost and easy viability in purified forms using simple purification methods. In the present review, a comprehensive trial has been advanced to elaborate on the different types and structures of fungal enzymes as well as the current status of the uses of fungal enzymes in various applications.

Differential responses of salivary cortisol, amylase, and chromogranin A to academic stress

Salivary biomarkers have been widely used to help diagnose stress, anxiety, and/or depression. This study aimed to compare the responses of three commonly investigated salivary stress biomarkers that represent the hypothalamic-pituitary-adrenal activity (cortisol; sCort) and the sympathetic activity (alpha-amylase; sAA and chromogranin A; sCgA), using academic oral presentation as a model of stress. Twenty postgraduate dental students attended the seminar class as presenter and audience. The presenters' performances were evaluated by the instructors suggesting more stress than the audience. The saliva was collected two times: before attending class and after an academic presentation (for presenters) or during the class (for audience). The pulse rates (PR) were also recorded. The results showed that the levels of all three biomarkers, as well as PR, were significantly higher in the presenter group compared with the audience group; however, the changes were most prominent with sCort and sAA (99.56 ± 12.76% for sCort, 93.48 ± 41.29% for sAA, 16.86 ± 6.42% for sCgA, and 15.06 ± 3.41% for PR). When compared between pre-post presentation, the levels of sCgA were not different, while those of sCort and sAA were significantly increased. These results suggest more sensitive reactivity to academic stress of sCort and sAA compared with sCgA and that the response of sCgA did not necessarily follow sAA pattern even though both are claimed to reflect the sympathetic activity. More studies are needed to elucidate the roles of sCgA in stress.

Murine Salivary Amylase Protects Against Streptococcus mutans-Induced Caries

Saliva protects dental surfaces against cavities (i. e., dental caries), a highly prevalent infectious disease frequently associated with acidogenic Streptococcus mutans. Substantial in vitro evidence supports amylase, a major constituent of saliva, as either protective against caries or supporting caries. We therefore produced mice with targeted deletion of salivary amylase (Amy1) and determined the impact on caries in mice challenged with S. mutans and fed a diet rich in sucrose to promote caries. Total smooth surface and sulcal caries were 2.35-fold and 1.79-fold greater in knockout mice, respectively, plus caries severities were twofold or greater on sulcal and smooth surfaces. In in vitro experiments with samples of whole stimulated saliva, amylase expression did not affect the adherence of S. mutans to saliva-coated hydroxyapatite and slightly increased its aggregation in solution (i.e., oral clearance). Conversely, S. mutans in biofilms formed in saliva with 1% glucose displayed no differences when cultured on polystyrene, but on hydroxyapatite was 40% less with amylase expression, suggesting that recognition by S. mutans of amylase bound to hydroxyapatite suppresses growth. However, this effect was overshadowed in vivo, as the recoveries of S. mutans from dental plaque were similar between both groups of mice, suggesting that amylase expression helps decrease plaque acids from S. mutans that dissolve dental enamel. With amylase deletion, commensal streptococcal species increased from ~75 to 90% of the total oral microbiota, suggesting that amylase may promote higher plaque pH by supporting colonization by base-producing oral commensals. Importantly, collective results indicate that amylase may serve as a biomarker of caries risk.

Effects of oral lubrication on satiety, satiation and salivary biomarkers in model foods: A pilot study

With a dramatic increase in overweight and population with obesity over the last decades, there is an imminent need to tackle this issue using novel strategies. Addressing obesity issues by generating satiety in food to reduce energy intake has been one of those prominent strategies and often textural interventions have been used to generate satiety, specifically in short-term trials. This study aimed to investigate the role of preloads varying in their oral lubricating properties on appetite sensations, food intake, salivary friction and concentration of salivary biomarkers (proteins, α-amylase and mucins) in collected human saliva (n = 17 healthy participants). The preloads were model foods (flavoured hydrogels) either high or low in their lubricating properties, assessed both by instrumental and sensorial measurements. The results showed that hunger and desire to eat decreased immediately after preload and remained decreased for 10 and 20 min, respectively, after preload in the high lubricating condition compared to control (all p < 0.05). Fullness increased immediately after preload and remained increased for 10 and 20 min, respectively, after preload in high lubricating condition compared to control (p < 0.05). However, after controlling the values for baseline, such significant effect of the intervention did not exist anymore. Only the effect of time is observed. Consuming high lubricating hydrogels showed no effect on food intake and salivary biomarkers in this pilot study. Salivary lubrication correlated with feeling of fullness. Considering the issue of large time-interval (30 min) between preload and next meal in this study, it is worthwhile investigating the immediate effects of oral lubrication on appetite control, food intake and salivary biomarkers.

Technical and Methodological Aspects of Cell-Free Nucleic Acids Analyzes

Analyzes of cell-free nucleic acids (cfNAs) have shown huge potential in many biomedical applications, gradually entering several fields of research and everyday clinical care. Many biological properties of cfNAs can be informative to gain deeper insights into the function of the organism, such as their different types (DNA, RNAs) and subtypes (gDNA, mtDNA, bacterial DNA, miRNAs, etc.), forms (naked or vesicle bound NAs), fragmentation profiles, sequence composition, epigenetic modifications, and many others. On the other hand, the workflows of their analyzes comprise many important steps, from sample collection, storage and transportation, through extraction and laboratory analysis, up to bioinformatic analyzes and statistical evaluations, where each of these steps has the potential to affect the outcome and informational value of the performed analyzes. There are, however, no universal or standard protocols on how to exactly proceed when analyzing different cfNAs for different applications, at least according to our best knowledge. We decided therefore to prepare an overview of the available literature and products commercialized for cfNAs processing, in an attempt to summarize the benefits and limitations of the currently available approaches, devices, consumables, and protocols, together with various factors influencing the workflow, its processes, and outcomes.

Disposable Stochastic Sensors Based on Nanolayer Deposition(s) of Silver and AgC Composite on Plastic for the Assay of α-amylase in Whole Blood and Saliva

Nanolayer deposition(s) of Ag and AgC composite on a plastic substrate was used to design disposable stochastic sensors. Three shapes of nanocoatings were tested. The first shape was obtained by deposition of a nanofilm of Ag on the plastic material; the second shape was obtained by deposition of a composite AgC nanolayer on the plastic material; the third shape was obtained by nanolayer deposition of a composite material of AgC on the top of the Ag nanofilm deposited on the plastic material. α-Cyclodextrin was used to modify the active surface of the sensor. Wide linear concentration ranges were obtained as follows: for de-assay of α-amylase in whole blood: 1.00 × 10⁻⁷–1.00 × 10³ U mL⁻¹ and for the assay of α-amylase in saliva: 1.5 × 10⁻¹⁵–1.5 × 10² U mL⁻¹. α-Amylase was reliably determined from whole blood and saliva samples using the proposed disposable stochastic sensors.

Quantify the Protein-Protein Interaction Effects on Adsorption Related Lubricating Behaviors of α-Amylase on a Glass Surface

Dental ceramic material is one of the widely preferred restorative materials to mimic the natural tooth enamel surface. However, it has continuously been degraded because of low wear resistance during mastication in the oral cavity. The friction involved was reduced by introducing the lubricant saliva protein layers to improve the wear resistance of the dental materials. However, little is understood regarding how the protein-protein interactions (PPI) influence the adsorbed-state structures and lubricating behaviors of saliva proteins on the ceramic material surface. The objective of this study is to quantify the influences of PPI effects on the structural changes and corresponding oral lubrications of adsorbed α-amylase, one of the abundant proteins in the saliva, on the dental ceramic material with glass as a model surface. α-Amylase was first adsorbed to glass surface under varying protein solution concentrations to saturate the surface to vary the PPI effects over a wide range. The areal density of the adsorbed protein was measured as an indicator of the level of PPI effects within the layer, and these values were then correlated with the measurements of the adsorbed protein's secondary structure and corresponding friction coefficient. The decreased friction coefficient value was an indicator of the lubricated surfaces with higher wear resistance. Our results indicate that PPI effects help stabilize the structure of α-amylase adsorbed on glass, and the correlation observed between the friction coefficient and the conformational state of adsorbed α-amylase was apparent. This study thus provides new molecular-level insights into how PPI influences the structure and lubricating behaviors of adsorbed protein, which is critical for the innovations of dental ceramic material designs with improved wear resistance.

Ixeris dentata and Lactobacillus gasseri Extracts Improve Salivary Secretion Capability in Diabetes-Associated Dry Mouth Rat Model

Dry mouth, hyposalivation, or xerostomia is a significant problem in diabetic patients; however, there has been no way to relieve these symptoms. This study’s aim was to evaluate the effects of Ixeris dentata (IXD) in combination with lactobacillus extract on the salivation rate in diabetes-induced dry mouth, and its mechanism was also investigated. In the streptozotocin (STZ)-induced diabetes model, the dry mouth condition was established as a model. Here, rats were treated with water or IXD through the sublingual spray, and subsequently treated with or without a spray of lactobacillus extract. In diabetes condition, the salivary flow rate, amylase activity, and aquaporin-5 and Na⁺/H⁺ exchanger (NHE-1) expressions were markedly decreased, whereas they were more significantly recovered in the sequential treatment of IXD-lactobacillus extract than in each single treatment. Furthermore, oxidative stress and its related ER stress response were especially regulated in the IXD/lactobacillus extract condition, where the following anti-oxidative enzymes, glutathione assay (GSH: GSSG) ratio, superoxide dismutase (SOD), and glutathione peroxidase (GPx), were involved. This study suggests that the combination of IXD and lactobacillus would be a potential alternative medicine against diabetes-induced hyposalivation and xerostomia.

Salivary Alpha-Amylase Mediates the Increase in Hunger Levels in Adolescents with Excess Weight after Viewing Food Images

Background: Salivary alpha-amylase (sAA) initiates the digestion process in the mouth and its levels might influence feelings of hunger and the propensity toward obesity. This study aims to evaluate basal differences in sAA between adolescents with excess weight (EW) and normal weight (NW), and the associations between sAA levels and feelings of hunger after viewing food images. Methods: Adolescents (13-18 years old) classified as EW (n = 30) or NW (n = 30) participated in the study. Saliva samples were collected before the administration of a food-choice task. Hunger was evaluated before and after the food-choice task. Results: EW adolescents showed lower basal sAA levels than NW adolescents and a greater increase in hunger levels after viewing food images. In addition, sAA levels had a significant inverse relationship with the increase in hunger in EW adolescents, but not in NW adolescents. Finally, significant inverse associations between sAA, BMI, and body fat percentage were found. Conclusions: Levels of hunger and changes therein, after viewing food are dependent on sAA levels in EW adolescents. This finding indicates that sAA levels may be a mediator of feelings of hunger in individuals with overweight in the context of viewing food cues, suggesting the utility of the sAA enzyme as a marker of hunger and propensity toward obesity.

Effects of strategic early-morning caffeine gum administration on association between salivary alpha-amylase and neurobehavioural performance during 50 h of sleep deprivation

Self-assessment is the most common method for monitoring performance and safety in the workplace. However, discrepancies between subjective and objective measures have increased interest in physiological assessment of performance. In a double-blind placebo-controlled study, 23 healthy adults were randomly assigned to either a placebo (n = 11; 5 F, 6 M) or caffeine condition (n = 12; 4 F, 8 M) while undergoing 50 h (i.e. two days) of total sleep deprivation. In previous work, higher salivary alpha-amylase (sAA) levels were associated with improved psychomotor vigilance and simulated driving performance in the placebo condition. In this follow-up article, the effects of strategic caffeine administration on the previously reported diurnal profiles of sAA and performance, and the association between sAA and neurobehavioural performance were investigated. Participants were given a 10 h baseline sleep opportunity (monitored via standard polysomnography techniques) prior to undergoing sleep deprivation (total sleep time: placebo = 8.83 ± 0.48 h; caffeine = 9.01 ± 0.48 h). During sleep deprivation, caffeine gum (200 mg) was administered at 01:00 h, 03:00 h, 05:00 h, and 07:00 h to participants in the caffeine condition (n = 12). This strategic administration of caffeine gum (200 mg) has been shown to be effective at maintaining cognitive performance during extended wakefulness. Saliva samples were collected, and psychomotor vigilance and simulated driving performance assessed at three-hour intervals throughout wakefulness. Caffeine effects on diurnal variability were compared with previously reported findings in the placebo condition (n = 11). The impact of caffeine on the circadian profile of sAA coincided with changes in neurobehavioural performance. Higher sAA levels were associated with improved performance on the psychomotor vigilance test during the first 24 h of wakefulness in the caffeine condition. However, only the association between sAA and response speed (i.e. reciprocal-transform of mean reaction time) was consistent across both days of sleep deprivation. The association between sAA and driving performance was not consistent across both days of sleep deprivation. Results show that the relationship between sAA and reciprocal-transform of mean reaction time on the psychomotor vigilance test persisted in the presence of caffeine, however the association was relatively weaker as compared with the placebo condition.

Ixeris dentata extract regulates salivary secretion through the activation of aquaporin-5 and prevents diabetes-induced xerostomia

The aim of this study was to investigate the effects of Ixeris dentata (IXD) extract to improve the salivation rate in dry mouth induced by diabetes. Both control and diabetic rats were treated with a sublingual spray of either water or IXD extract to determine the effects of IXD on salivation. During the study, we observed that IXD extract treatment increased the salivary flow rate in diabetic rats. The expression of α-amylase was increased significantly in both saliva and glandular tissue lysates of IXD-treated diabetic rats. Aquaporin-5 protein expression was abnormally low in the salivary glands of diabetic rats, which increased hyposalivation and led to salivary dysfunction. However, a single oral spray of IXD extract drastically increased the expression of aquaporin-5 in salivary gland acinar and ductal cells in diabetic rats. Moreover, IXD extract induced expression of Na⁺/H⁺ exchangers in the salivary gland, which suggests that Na⁺/H⁺ exchangers modulate salivary secretions and aid in the fluid-secretion mechanism. Furthermore, transient treatment with IXD extract increased the intracellular calcium in human salivary gland cells. Taken together, these results suggest the potential value of an IXD extract for the treatment of diabetes-induced hyposalivation and xerostomia.

Capillary isoelectric focusing with whole column imaging detection (iCIEF): A new approach to the characterization and quantification of salivary α-amylase

Saliva is an easily collected biological fluid with potentially important diagnostic value. While gel electrophoresis is generally used for salivary analysis, we employed the capillary isoelectric focusing technique to allow for a rapid, automated mode of electrophoresis. Capillary isoelectric focusing coupled with UV whole column imaging detection (iCIEF) was used to develop a robust protocol to characterize salivary α-amylase collected from various glands. Notably, three sample preparation methods were examined: ultrafiltration, gel-filtration, and starch affinity interaction with salivary amylase. Salivary α-amylase separated into two major peaks before sample treatment; while both filtration methods and starch affinity interaction of salivary amylase enhanced the resolution of isozymes, desalting with gel-filtration displayed the best recovery and the highest resolution of isozymes. Good agreement existed between the observed isoelectric points and the values reported in the literature. In addition, a high level of precision was apparent, and the relative standard deviation for replicates was less than 0.5% for pIs (peak positions) and below 10% for peak area. Furthermore, saliva secreted from the parotid gland proved to have a higher amylase content compared to either secretions from the submandibular/sublingual complex, or whole saliva, as well as amylase enhancement under stimulation. The results suggest that the iCIEF technique can be used to accurately resolve and quantitate amylase isozymes in a rapid and automated fashion, and that gel-filtration should be applied to saliva samples beforehand to allow for optimal purification and characterization.

Endocrine and emotional response to exclusion among women and men; cortisol, salivary alpha amylase, and mood

BACKGROUND AND OBJECTIVES

Social exclusion is ubiquitous and painful. Evolutionary models indicate sex differences in coping with social stress. Recent empirical data suggest different sex patterns in hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) reactivity. The present study sought to test this hypothesis.

DESIGN

We examined differences in endocrine and emotional response to exclusion by using a virtual ball tossing paradigm (Cyberball). Saliva samples and mood ratings were collected to reflect levels before, and repeatedly following, exclusion.

METHODS

The sample included 21 women and 23 men. Cortisol and salivary alpha amylase (sAA), biomarkers of the HPA and SAM systems, respectively, were used as indices of two arms of stress response.

RESULTS

Following exclusion, all participants experienced mood worsening followed by mood improvement, with men reporting less distress than women. Women evinced decline in cortisol following the Cyberball task, whereas men's cortisol levels showed a non-significant rise, and then decline, following exclusion.

CONCLUSIONS

Our results concur with previous findings showing SAM reactivity to be gender-neutral and HPA reactivity to be gender-divergent. Additional studies are needed to examine sex-specific response to social exclusion. Implications for individual differences in recovery from stress are discussed.

Label-Free Detection of Human Glycoprotein (CgA) Using an Extended-Gated Organic Transistor-Based Immunosensor

Herein, we report on the fabrication of an extended-gated organic field-effect transistor (OFET)-based immunosensor and its application in the detection of human chromogranin A (hCgA). The fabricated OFET device possesses an extended-gate electrode immobilized with an anti-CgA antibody. The titration results of hCgA showed that the electrical changes in the OFET characteristics corresponded to the glycoprotein recognition ability of the monoclonal antibody (anti-CgA). The observed sensitivity (detection limit: 0.11 µg/mL) and selectivity indicate that the OFET-based immunosensor can be potentially applied to the rapid detection of the glycoprotein concentration without any labeling.

An Organic Field-effect Transistor with an Extended-gate Electrode Capable of Detecting Human Immunoglobulin A

We herein report on the development of an extended-gate type organic field-effect transistor (OFET)-based immunosensor for the detection of human immunoglobulin A (IgA). The titration results of IgA exhibited shifts in the transfer characteristics of the OFET sensor device with increasing IgA concentration. A linear detection range from 0 to 10 μg/mL was realized with a detection limit of 2.1 μg/mL, indicating that the OFET-based immunosensor can be potentially applied to the monitoring of infectious diseases and psychological stress in daily life.

Preparation of nanosized coacervates of positive and negative starch derivatives intended for pulmonary delivery of proteins

Use of charged starch-derivatives as nanoscaled protein carriers and their in vitro evaluation.

Comparative two-dimensional polyacrylamide gel electrophoresis of the salivary proteome of children with autism spectrum disorder

In the last decades, prevalence of autism spectrum disorder (ASD) has been on the rise. However, clear aetiology is still elusive and improvements in early diagnosis are needed. To uncover possible biomarkers present in ASD, we used two-dimensional polyacrylamide gel electrophoresis and nanoliquid chromatography-tandem mass spectrometry (nanoLC-MS/MS), to compare salivary proteome profiling of children with ASD and controls. A total of 889 spots were compared and only those spots with a fold change ≥1.7 and a P-value <0.05 or a fold change of ≥3.0 between ASD cases and controls were analysed by nanoLC-MS/MS. Alpha-amylase, CREB-binding protein, p532, Transferrin, Zn alpha2 glycoprotein, Zymogen granule protein 16, cystatin D and plasminogen were down-regulated in ASD. Increased expression of proto-oncogene Frequently rearranged in advanced T-cell lymphomas 1 (FRAT1), Kinesin family member 14, Integrin alpha6 subunit, growth hormone regulated TBC protein 1, parotid secretory protein, Prolactin-inducible protein precursor, Mucin-16, Ca binding protein migration inhibitory factor-related protein 14 (MRP14) was observed in individuals with ASD. Many of the identified proteins have previously been linked to ASD or were proposed as risk factors of ASD at the genetic level. Some others are involved in pathological pathways implicated in ASD causality such as oxidative stress, lipid and cholesterol metabolism, immune system disturbances and inflammation. These data could contribute to protein signatures for ASD presence, risk and subtypes, and advance understanding of ASD cause as well as provide novel treatment targets for ASD.

Alpha-Amylase Activity in Blood Increases after Pharmacological, But Not Psychological, Activation of the Adrenergic System

BACKGROUND & AIM

Alpha-amylase in both blood and saliva has been used as a diagnostic parameter. While studies examining alpha-amylase activity in saliva have shown that it is sensitive to physiological and psychological challenge of the adrenergic system, no challenge studies have attempted to elucidate the role of the adrenergic system in alpha-amylase activity in blood. We set out to examine the impact of psychological and pharmacological challenge on alpha-amylase in blood in two separate studies.

METHODS

In study 1, healthy subjects were examined in a placebo-controlled, double-blind paradigm using yohimbine, an alpha2-adrenergic antagonist. In study 2, subjects were examined in a standardized rest-controlled psychosocial stress protocol. Alpha-amylase activity in blood was repeatedly measured in both studies.

RESULTS

Results of study 1 showed that alpha-amylase in blood is subject to stronger increases after injection of yohimbine compared to placebo. In study 2, results showed that there was no significant effect of psychological stress compared to rest.

CONCLUSIONS

Alpha-amylase in blood increases after pharmacological activation of the adrenergic pathways suggesting that sympathetic receptors are responsible for these changes. Psychological stress, however, does not seem to have an impact on alpha-amylase in blood. Our findings provide insight into the mechanisms underlying activity changes in alpha-amylase in blood in healthy individuals.

Chronic stress impacts the cardiovascular system: animal models and clinical outcomes

Psychological stresses are associated with cardiovascular diseases to the extent that cardiovascular diseases are among the most important group of psychosomatic diseases. The longstanding association between stress and cardiovascular disease exists despite a large ambiguity about the underlying mechanisms. An array of possibilities have been proposed including overactivity of the autonomic nervous system and humoral changes, which then converge on endothelial dysfunction that initiates unwanted cardiovascular consequences. We review some of the features of the two most important stress-activated systems, i.e., the humoral and nervous systems, and focus on alterations in endothelial function that could ensue as a result of these changes. Cardiac and hematologic consequences of stress are also addressed briefly. It is likely that activation of the inflammatory cascade in association with oxidative imbalance represents key pathophysiological components of stress-induced cardiovascular changes. We also review some of the commonly used animal models of stress and discuss the cardiovascular outcomes reported in these models of stress. The unique ability of animals for adaptation under stressful conditions lessens the extrapolation of laboratory findings to conditions of human stress. An animal model of unpredictable chronic stress, which applies various stress modules in a random fashion, might be a useful solution to this predicament. The use of stress markers as indicators of stress intensity is also discussed in various models of animal stress and in clinical studies.

α-Amylase in Vaginal Fluid: Association With Conditions Favorable to Dominance of Lactobacillus

Vaginal glycogen is degraded by host α-amylase and then converted to lactic acid by Lactobacilli. This maintains the vaginal pH at ≤4.5 and prevents growth of other bacteria. Therefore, host α-amylase activity may promote dominance of Lactobacilli. We evaluated whether the α-amylase level in vaginal fluid is altered in women with bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) and whether its concentration was associated with levels of lactic acid isomers and host mediators. Vaginal fluid was obtained from 43 women with BV, 50 women with VVC, and 62 women with no vulvovaginal disorders. Vaginal fluid concentrations of α-amylase, secretory leukocyte protease inhibitor (SLPI), hyaluronan, hyaluronidase-1, β-defensin, and elafin were measured by enzyme-linked immunosorbent assay (ELISA). Vaginal concentrations of neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase (MMP) 8, and d- and l-lactic acid levels in these patients were previously reported. The median vaginal fluid α-amylase level was 1.83 mU/mL in control women, 1.45 mU/mL in women with VVC, and 1.07 mU/mL in women with BV. Vaginal levels of α-amylase were correlated with d-lactic acid (P = .003) but not with l-lactic acid (P > .05) and with SLPI (P < .001), hyaluronidase-1 (P < .001), NGAL (P = .001), and MMP-8 (P = .005). The exfoliation of glycogen-rich epithelial cells into the vaginal lumen by hyaluronidase-1 and MMP-8 may increase glycogen availability and promote α-amylase activity. The subsequent enhanced availability of glycogen breakdown products would favor proliferation of Lactobacilli, the primary producers of d-lactic acid in the vagina. Concomitant production of NGAL and SLPI would retard growth of BV-related bacteria.

The Secretion and Action of Brush Border Enzymes in the Mammalian Small Intestine

Microvilli are conventionally regarded as an extension of the small intestinal absorptive surface, but they are also, as latterly discovered, a launching pad for brush border digestive enzymes. Recent work has demonstrated that motor elements of the microvillus cytoskeleton operate to displace the apical membrane toward the apex of the microvillus, where it vesiculates and is shed into the periapical space. Catalytically active brush border digestive enzymes remain incorporated within the membranes of these vesicles, which shifts the site of BB digestion from the surface of the enterocyte to the periapical space. This process enables nutrient hydrolysis to occur adjacent to the membrane in a pre-absorptive step. The characterization of BB digestive enzymes is influenced by the way in which these enzymes are anchored to the apical membranes of microvilli, their subsequent shedding in membrane vesicles, and their differing susceptibilities to cleavage from the component membranes. In addition, the presence of active intracellular components of these enzymes complicates their quantitative assay and the elucidation of their dynamics. This review summarizes the ontogeny and regulation of BB digestive enzymes and what is known of their kinetics and their action in the peripheral and axial regions of the small intestinal lumen.

Global stress response during a social stress test: impact of alexithymia and its subfactors

OBJECTIVES

Alexithymia is a personality trait characterized by difficulties in identifying, describing and communicating one's own emotions. Recent studies have associated specific effects of this trait and its subfactors with hypothalamo-pituitary-adrenal (HPA) axis markers during stress. The aim of this study was to analyze the association between alexithymia and its subfactors with HPA and sympatho-adrenal medullar (SAM) activity. Stress was induced experimentally using a public-speaking paradigm. Salivary cortisol, alpha-amylase (AA), chromogranin A (CgA) and heart rate (HR) were collected during the defined periods of baseline, stress, and recovery in 19 males and 24 female healthy university students.

RESULTS

Subjects reacted to the stressor with a significant cortisol and SAM response. Subjects scoring high on alexithymia reacted significantly more intensely than low scorers in basal anticipatory as well as peak cortisol and area under the curve. Regression analyses revealed that the increased HPA activity was related to only one alexithymia subfactor, the difficulty in differentiating feelings and distinguishing them from bodily sensations and emotion arousal.

CONCLUSION

Alexithymia and its subfactors were specifically related to cortisol responses. This research should be replicated with more subjects and should take into account more parameters reflecting sympathetic and/or parasympathetic activation, as well as HPA axis. Factors such as coping strategies and the perception of the situation as a challenge have also to be explored.

Green tea consumption after intense taekwondo training enhances salivary defense factors and antibacterial capacity

The aim of this study was to investigate the short-term effects of green tea consumption on selected salivary defense proteins, antibacterial capacity and anti-oxidation activity in taekwondo (TKD) athletes, following intensive training. Twenty-two TKD athletes performed a 2-hr TKD training session. After training, participants ingested green tea (T, caffeine 6 mg/kg and catechins 22 mg/kg) or an equal volume of water (W). Saliva samples were collected at three time points: before training (BT-T; BT-W), immediately after training (AT-T; AT-W), and 30 min after drinking green tea or water (Rec-T; Rec-W). Salivary total protein, immunoglobulin A (SIgA), lactoferrin, α-amylase activity, free radical scavenger activity (FRSA) and antibacterial capacity were measured. Salivary total protein, lactoferrin, SIgA concentrations and α-amylase activity increased significantly immediately after intensive TKD training. After tea drinking and 30 min rest, α-amylase activity and the ratio of α-amylase to total protein were significantly higher than before and after training. In addition, salivary antibacterial capacity was not affected by intense training, but green tea consumption after training enhanced salivary antibacterial capacity. Additionally, we observed that salivary FRSA was markedly suppressed immediately after training and quickly returned to pre-exercise values, regardless of which fluid was consumed. Our results show that green tea consumption significantly enhances the activity of α-amylase and salivary antibacterial capacity.

HPA and SAM axis responses as correlates of self- vs parental ratings of anxiety in boys with an Autistic Disorder

Anxiety and Autistic Disorder (AD) are both neurological conditions and both disorders share some features that make it difficult to precisely allocate specific symptoms to each disorder. HPA and SAM axis activities have been conclusively associated with anxiety, and may provide a method of validating anxiety rating scale assessments given by parents and their children with AD about those children. Data from HPA axis (salivary cortisol) and SAM axis (salivary alpha amylase) responses were collected from a sample of 32 high-functioning boys (M age=11yr) with an Autistic Disorder (AD) and were compared with the boys' and their mothers' ratings of the boys' anxiety. There was a significant difference between the self-ratings given by the boys and ratings given about them by their mothers. Further, only the boys' self-ratings of their anxiety significantly predicted the HPA axis responses and neither were significantly related to SAM axis responses. Some boys showed cortisol responses which were similar to that previously reported in children who had suffered chronic and severe anxiety arising from stressful social interactions. As well as suggesting that some boys with an AD can provide valid self-assessments of their anxiety, these data also point to the presence of very high levels of chronic HPA-axis arousal and consequent chronic anxiety in these boys.

Salivary alpha amylase activity in human beings of different age groups subjected to psychological stress

Salivary alpha-amylase (sAA) has been proposed as a sensitive non-invasive biomarker for stress-induced changes in the body that reflect the activity of the sympathetic nervous system. Though several experiments have been conducted to determine the validity of this salivary component as a reliable stress marker in human subjects, the effect of stress induced changes on sAA level in different age groups is least studied. This article reports the activity of sAA in human subjects of different age groups subjected to psychological stress induced through stressful video clip. Differences in sAA level based on sex of different age groups under stress have also been studied. A total of 112 subjects consisting of both the male and female subjects, divided into two groups on basis of age were viewed a video clip of corneal transplant surgery as stressor. Activity of sAA from saliva samples of the stressed subjects were measured and compared with the activity of the samples collected from the subjects before viewing the clip. The age ranges of subjects were 18-25 and 40-60 years. The sAA level increased significantly in both the groups after viewing the stressful video. The increase was more pronounced in the younger subjects. The level of sAA was comparatively more in males than females in the respective groups. No significant change in sAA activity was observed after viewing the soothed video clip. Significant increase of sAA level in response to psychological stress suggests that it might act as a reliable sympathetic activity biochemical marker in different stages of human beings.

Is salivary alpha-amylase an indicator of autonomic nervous system dysregulations in mental disorders?--a review of preliminary findings and the interactions with cortisol

During recent years, a growing interest emerged in using salivary alpha-amylase (sAA) as a non-invasive, surrogate marker for sympathetic activity. Numerous studies applying stress protocols have demonstrated that sAA is highly sensitive to stress-related changes (in healthy subjects). Additionally, it was suggested that sAA might moreover serve as an index for pathological dysregulation of the autonomic nervous system (ANS) in patients showing psychopathology. Since then, a small but growing literature investigated sAA in patients with mental disorders. This review aims to give an overview of preliminary findings in this field of research. The results of n=15 studies are described in detail and implications for further research are discussed. Although the number of studies and the samples examined were rather small, changes in sAA, reflecting adrenergic dysregulation, could be demonstrated in psychopathology, especially in anxiety-related disorders. This field of research is still in its early stages. However, the studies included in this review revealed first evidence that the employment of sAA, as an indicator of ANS dysregulation in mental disorders, is promising.

Standardization of sample collection, isolation and analysis methods in extracellular vesicle research

The emergence of publications on extracellular RNA (exRNA) and extracellular vesicles (EV) has highlighted the potential of these molecules and vehicles as biomarkers of disease and therapeutic targets. These findings have created a paradigm shift, most prominently in the field of oncology, prompting expanded interest in the field and dedication of funds for EV research. At the same time, understanding of EV subtypes, biogenesis, cargo and mechanisms of shuttling remains incomplete. The techniques that can be harnessed to address the many gaps in our current knowledge were the subject of a special workshop of the International Society for Extracellular Vesicles (ISEV) in New York City in October 2012. As part of the “ISEV Research Seminar: Analysis and Function of RNA in Extracellular Vesicles (evRNA)”, 6 round-table discussions were held to provide an evidence-based framework for isolation and analysis of EV, purification and analysis of associated RNA molecules, and molecular engineering of EV for therapeutic intervention. This article arises from the discussion of EV isolation and analysis at that meeting. The conclusions of the round table are supplemented with a review of published materials and our experience. Controversies and outstanding questions are identified that may inform future research and funding priorities. While we emphasize the need for standardization of specimen handling, appropriate normative controls, and isolation and analysis techniques to facilitate comparison of results, we also recognize that continual development and evaluation of techniques will be necessary as new knowledge is amassed. On many points, consensus has not yet been achieved and must be built through the reporting of well-controlled experiments.

Measurements of salivary alpha amylase and salivary cortisol in hominoid primates reveal within-species consistency and between-species differences

Salivary alpha amylase (sAA) is the most abundant enzyme in saliva. Studies in humans found variation in enzymatic activity of sAA across populations that could be linked to the copy number of loci for salivary amylase (AMY1), which was seen as an adaptive response to the intake of dietary starch. In addition to diet dependent variation, differences in sAA activity have been related to social stress. In a previous study, we found evidence for stress-induced variation in sAA activity in the bonobos, a hominoid primate that is closely related to humans. In this study, we explored patterns of variation in sAA activity in bonobos and three other hominoid primates, chimpanzee, gorilla, and orangutan to (a) examine if within-species differences in sAA activity found in bonobos are characteristic for hominoids and (b) assess the extent of variation in sAA activity between different species. The results revealed species-differences in sAA activity with gorillas and orangutans having higher basal sAA activity when compared to Pan. To assess the impact of stress, sAA values were related to cortisol levels measured in the same saliva samples. Gorillas and orangutans had low salivary cortisol concentrations and the highest cortisol concentration was found in samples from male bonobos, the group that also showed the highest sAA activity. Considering published information, the differences in sAA activity correspond with differences in AMY1 copy numbers and match with general features of natural diet. Studies on sAA activity have the potential to complement molecular studies and may contribute to research on feeding ecology and nutrition.

Salivary alpha-amylase activity and salivary flow rate in young adults

The secretion of salivary alpha-amylase (sAA) is more associated with psychoneuroendocrinological response to stress than with the flow rate and age. The aim of this cross sectional study is to build an explanatory model based on patterns of relationship between age 20-39 in resting and stimulated saliva under no stressful condition in healthy volunteers. Both resting and stimulated saliva were collected from 40 subjects. The sAA values were log-transformed, the normality assumption was verified with the Shapiro-Wilk test and the reliability of the measurements was estimated by the Pearsons’ r correlation coefficient. The estimated model was based on the theory of the Linear Mixed Models. Significant mean changes were observed in flow rate and sAA activity between resting and stimulated saliva. The final model consists of two components, the first revealed a positive correlation between age and sAA while the second one revealed a negative correlation between the interaction of age × flow rate in its condition (resting or stimulated saliva), with sAA. Both flow rate and age influence sAA activity.

Effects of 50 Hz magnetic field exposure on the stress marker α-amylase in the rat mammary gland

PURPOSE

Concerns about adverse health effects of environmental exposure to 50/60 Hz magnetic fields (MF) have initiated numerous studies on laboratory animals with varying outcomes. Previously, we reported that rat strains responded differently to MF regarding mammary cell proliferation and tumor development indicating that (epi)genetic factors might influence MF effects in the breast tissue, yet without any identified mechanism. In the present study, α-amylase, recently introduced as a stress marker in humans, was investigated in the mammary gland of Fischer 344 (F344) and Lewis rats, two strains with distinct stress sensitivity.

MATERIALS AND METHODS

F344 rats were sham- and MF-exposed (50 Hz, 100 μT) for different time periods, Lewis rats for two weeks. For comparison, diethylstilbestrol was administered at single or repeated doses.

RESULTS

α-Amylase activity was significantly enhanced in the F344 mammary glands after 2 and 4 weeks of MF, whereas no reproducible effects were observed in Lewis rats. Diethylstilbestrol increased the α-amylase after repeated dosing.

CONCLUSIONS

Although α-amylase represents a difficult parameter in animal studies because of its stress sensitivity, it should be considered for investigations in humans and cell cultures as a biomarker for MF susceptibility and a target to examine possible MF mechanisms since α-amylase affects cell growth.

Involvement of minor salivary glands in the pathogenesis of peritonsillar abscess

OBJECTIVES

To study the relationship between peritonsillar abscess (PTA) and minor salivary glands surrounding the palatine tonsils.

STUDY DESIGN

Prospective population-based study.

SETTINGS

Tertiary care university hospital.

SUBJECTS AND METHOD

Prospective study including 41 patients with PTA and 6 patients with a neck abscess. Amylase levels of the pus and serum were measured and compared between the 2 groups. Clinical data regarding hospitalization length and recurrence rate were also collected.

RESULTS

Of the 41 patients with PTA, 7 suffered from recurrent PTA. Average level of amylase in the pus of the PTA group was 3841 U/L versus 7.7 U/L in the neck abscess group (P < .001; median, 62 vs 9.5). Serum amylase was higher in the PTA group (49.3 U/L vs 37.3 U/L; P = .008). There were no recurrences in PTA patients with amylase greater than 65 U/dL in the pus in 0 of 20 (0%) versus 7 of 21 (33%) for amylase lower than 65 U/L (P = .01).

CONCLUSION

High amylase in the pus lends further support for involvement of minor salivary glands. However, high recurrence rates related to low amylase in the pus imply an additional pathogenesis possibly related to tonsillar infection. It is possible that both minor salivary glands as well as tonsillar infection play a role in the pathogenesis of peritonsillar infections.