Salivary Production Research Articles

Correlation among ocular surface disease, xerostomia, and nasal symptoms in patients with differentiated thyroid carcinoma subjected to radioiodine therapy: A prospective comparative study

Some complications of radioiodine therapy have been reported, but the involvement of the eyes and adnexa is rarely discussed. The purpose of this study was to determine the correlation among ocular surface changes, xerostomia, and changes in the nasal mucosa associated with radioiodine therapy. Patients subjected to radioiodine therapy (group 1) or not subjected (group 2) were prospectively evaluated by examinations of the ocular surface and tear film, saliva production, and nasal endoscopy. Ocular and nasal symptoms and xerostomia were evaluated using questionnaires. Evaluation of the ocular surface did not indicate significant differences between the groups. Nasal endoscopy revealed higher mucosal pallor in group 1 and worsening of the endoscopic appearance. Worsening of ocular symptoms and nasal symptoms, xerostomia, and a significant decrease in salivary production was also observed in group 1. Subjective worsening of xerostomia, xerophthalmia, nasal symptoms, and changes in the nasal mucosa in group 1 was observed.

PREVALENCE OF DENTAL DECAY AND PERIODONTAL DISEASES AMONG CHILDREN SUFFERING FROM CONGENITAL HEART DISEASES. A LITERATURE REVIEW – PART III

Dental decay is one of the most prevalent chronic and infectious diseases for mankind. It is defined as `a dynamic process, taking place in the tooth bacterial biofilm (plaque), which results in a disturbance of equilibrium between tooth substance and the surrounding plaque fluid and finally results in a loss of minerals from the tooth surface - demineralisation.` Fluoride plays an important role in dental decay prevention and stimulates self-healing of minor cavities by reducing the demineralisation process and promoting the remineralization process. Remineralisation occurs frequently, especially when the biofilm pH is restored by saliva, which acts as a buffer. The adequate salivary production is of great importance for maintaining a normal physiology in the oral cavity. It is known that children with congenital heart disease (CHD) frequently require regular long-term medication, but the knowledge of oral health effects caused by long-term medication in medically compromised children is sparse. Many medications used on a long-term basis may contain sugar, have a low pH or high acidity. There is a strong correlation between xerostomia and pharmacological treatment and a number of drugs have been listed as xerogenic. These drugs include ones with a directly damaging to salivary glands function, such as cytotoxic drugs, medications with anticholinergic activity, drugs which deplete fluid as diuretics, and drugs acting on the sympathetic system, like antihypertensive drugs. Only a few clinical studies have been carried out on the outcome of salivary function with antihypertensive drugs, and the outcome is not clear-cut. A number of studies have been carried out on the caries prevalence in children with CHD but only five of them were controlled. Children with CHD had higher mean values of dmft /DMFT indices than healthy children and only a few of them had experienced fillings, indicating an unmet need for operative treatment.

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

ObjectiveTo investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects.Materials and methodsSeventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory—Student Survey questionnaire. Oral emanations of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide were measured using an Oral Chroma™ portable gas chromatograph. The amounts in saliva of total bacteria and seven bacteria associated with halitosis were quantified by qPCR. The in vitro production of H2S by S. moorei and/or F. nucleatum was also measured with the Oral Chroma™ instrument.ResultsThe stressed students group showed increased oral emanations of hydrogen sulfide and dimethyl sulfide, together with higher salivary Solobacterium moorei levels (p < 0.05, Mann Whitney test). There were moderate positive correlations between the following pairs of variables: Fusobacterium nucleatum and S. moorei; F. nucleatum and hydrogen sulfide; Tannerella forsythia and F. nucleatum; T. forsythia and S. moorei. These correlations only occurred for the stressed group (p < 0.05, Spearman correlation). The in vitro experiment demonstrated that S. moorei increased H2S production by F. nucleatum (p < 0.05, ANOVA and Tukey’s test).ConclusionThe increased amount of S. moorei in saliva, and its coexistence with F. nucleatum and T. forsythia, seemed to be responsible for increased oral hydrogen sulfide in the healthy male stressed subjects.

Copy number variation of human AMY1 is a minor contributor to variation in salivary amylase expression and activity

BackgroundSalivary amylase in humans is encoded by the copy variable gene AMY1 in the amylase gene cluster on chromosome 1. Although the role of salivary amylase is well established, the consequences of the copy number variation (CNV) at AMY1 on salivary amylase protein production are less well understood. The amylase gene cluster is highly structured with a fundamental difference between odd and even AMY1 copy number haplotypes. In this study, we aimed to explore, in samples from 119 unrelated individuals, not only the effects of AMY1 CNV on salivary amylase protein expression and amylase enzyme activity but also whether there is any evidence for underlying difference between the common haplotypes containing odd numbers of AMY1 and even copy number haplotypes.ResultsAMY1 copy number was significantly correlated with the variation observed in salivary amylase production (11.7% of variance, P < 0.0005) and enzyme activity (13.6% of variance, P < 0.0005) but did not explain the majority of observed variation between individuals. AMY1-odd and AMY1-even haplotypes showed a different relationship between copy number and expression levels, but the difference was not statistically significant (P = 0.052).ConclusionsProduction of salivary amylase is correlated with AMY1 CNV, but the majority of interindividual variation comes from other sources. Long-range haplotype structure may affect expression, but this was not significant in our data.

Effects of A Novel Disc Formulation on Dry Mouth Symptoms and Enamel Remineralization in Patients With Hyposalivation: An In Vivo Study.

The goal of this study was to identify the in vivo effects in patients with hyposalivation of a novel slowly dissolving adhering test disc upon on enamel remineralization, oral biofilm, salivary production, pH and buffering, gingival health, and on self-evaluation of oral well-being. Five subjects with xerostomia wore custom made retainers carrying 5 demineralized enamel chips for periods of 1 week each. In 1 study arm, subjects used the test agent plus oral hygiene self-care; in the other they used oral hygiene self-care only, with a 1 week washout in between arms. The treatment sequence was randomized. Before and after each study arm Plaque Index (PI), Gingival Index (GI) and Sulcus Bleeding Index (mSBI) were recorded. Clinical plaque staining was quantified using digital image analysis. Saliva production, pH and buffering capacity were recorded. Subjects completed a self-evaluation questionnaire for oral comfort. Enamel samples underwent standardized Knoop microhardness testing to quantify mineralization status. Plaque presence and clinical Plaque Indices decreased significantly with test agent use (p<0.05). Five-minute saliva production almost doubled 10 and 40 minutes after oral test disc insertion (significant, p<0.05). Salivary pH buffering improved in 4/5 subjects with disc use. All demineralized tooth samples re-hardened intraorally (p>0.05). The discs favorably impacted eating problems and dental sensitivity. Subjects were positive about disc flavor and mouth feel. Using established in vivo techniques, the effects of a novel product in xerostomic patients were evaluated and quantified. The adhering disc facilitated eating, reduced dental sensitivity, improved saliva production and buffering capacity, reduced plaque, and alleviated xerostomia symptoms. Xerostomia management is challenging. A novel dry mouth disc was effective in alleviating dry mouth symptoms.

The effects of essential oil, povidone-iodine, and chlorhexidine mouthwash on salivary nitrate/nitrite and nitrate-reducing bacteria.

Dietary nitrate is reduced to nitrite and nitric oxide by microbial flora, and this activity is beneficial to vascular health. It has been reported that this bacterial process is inhibited by chlorhexidine mouthwash, although the effects of other products are largely unknown. This study examined the effects of several treatments on salivary nitrate/nitrite and nitrate-reducing bacteria. Twelve university staff and students performed mouth-washing with water (control), essential oil, 0.35% povidone-iodine, or 0.0025% chlorhexidine and then ate 100 g lettuce (110 mg nitrate content), followed by collection of saliva and tongue bacteria at the baseline, and 1, 5, and 10 h thereafter. The individual treatments were separated by an interval of one week. Salivary nitrate/nitrite was measured by the calorimetric method, and a representative nitrate-reducing bacterial species, Veillonella dispar, was detected and semi-quantified using a polymerase chain reaction (PCR) assay. Significant increases in salivary nitrate/nitrite were observed for all treatments (all P < 0.05). The PCR assay showed that water, essential oil, and povidone-iodine mouthwash had little effect, whereas V. dispar DNA bands were markedly inhibited after washing with chlorhexidine. These results suggest that essential oil and povidone-iodine mouthwash have little effect on oral nitrate-reducing activity. Salivary nitrite production was not reduced by chlorhexidine, but the fainter band of V. dispar DNA suggests that longer daily use might blunt this nitrate-reducing activity.

Fibromyalgia and vibratory platform exercise: Cortisol improvement and women´s quality of life

OBJECTIVES: The main objective of this pilot study was to evaluate the effects of an exercise protocol, using vibratory platform, in quality of life and the cortisol rhythmicity in fibromyalgic women. METHODS: Twenty women, which 10 were healthy and 10 were diagnosed with fibromyalgia. All of them performed an exercise program on a vibratory platform and were evaluated for salivary cortisol production throughout the day before and after the treatment. The volunteers with fibromyalgia were also evaluated with a specific questionnaire for quality of life before and after the treatment. Salivary samples were collected at 6 a.m., noon, 6 p.m. and before bedtime, 10 p.m. Cortisol was quantified using immunoenzymatic assay. RESULTS: Women with fibromyalgia improved their quality of life and started to have an adjustment in the cortisol rhythmicity after exercise. Even considering the limitations of the volunteers’ number who participated in this pilot, a relationship between the improvement of the quality of life and the adjustment in the cortisol rhythmicity produced by the exercise program practiced could be assumed.

Circadian Melatonin Rhythm Following Traumatic Brain Injury

Background: Sleep-wake disturbances are highly prevalent following traumatic brain injury (TBI), impeding rehabilitaion and quality of life. However, the mechanisms underlying these sleep disturnbances are unclear, and efficacious treatments are lacking. To investigate possible mechanisms underlying sleep disturbance in TBI, we examined characteristics of the circadian rhythm of melatonin, a hormone involved in sleep-wake regulation. We compared TBI patients reporting sleep disturbance with age- and gender-matched healthy volunteers. Methods: We conducted an overnight observational study with salivary melatonin samples collected hourly in 9 patients with severe TBI and 9 controls. Salivary dim light melatonin onset (DLMO) as well as melatonin synthesis onset (SynOn) and offset (SynOff) were used to determine circadian timing. Total overnight salivary melatonin production was calculated as the area under the curve from melatonin synthesis onset to offset. Results: Compared with healthy individuals, TBI patients showed 42% less melatonin production overnight (d = 0.87; P = .034). The timing of DLMO was delayed by approximately 1.5 hours in patients with TBI compared with controls (d = 1.23; P = .003). Conclusions: In patients with TBI, melatonin production was attenuated overnight, and the timing of melatonin secretion was delayed. We suggest that disruption to the circadian regulation of melatonin synthesis is a feature of severe TBI, possibly contributing to the sleep difficulties that are commonly reported in this population.

A Natural Cattle Immune Response Against Horn Fly (Diptera: Muscidae) Salivary Antigens May Regulate Parasite Blood Intake.

The horn fly, Haematobia irritans (L.), is a blood-sucking ectoparasite that is responsible for sizeable economic losses in livestock. The salivary gland products facilitate blood intake. Taking advantage of the identification of novel H. irritans salivary antigens (Hematobin, HTB and Irritans 5, IT5), we investigated the parasite loads, H. irritans blood intake, and antibody response of naturally infected bovines during the fly season. Fly loads and fly hemoglobin content fluctuated during the trial. Each time horn fly loads exceeded 200 flies per cattle, a reduction in horn fly blood intake was observed three weeks later. All of the cattle elicited an antibody response against HTB and IT5 that declined once the fly season was over. Cattle anti-IT5 titers were positively correlated with parasite loads and negatively correlated with fly blood intake. These results suggest that the natural changes in the H. irritans blood intake observed in this study were associated with a natural host response against horn fly salivary antigens.

Correspondence between hair cortisol concentrations and 30-day integrated daily salivary and weekly urinary cortisol measures

Characterization of cortisol production, regulation and function is of considerable interest and relevance given its ubiquitous role in virtually all aspects of physiology, health and disease risk. The quantification of cortisol concentration in hair has been proposed as a promising approach for the retrospective assessment of integrated, long-term cortisol production. However, human research is still needed to directly test and validate current assumptions about which aspects of cortisol production and regulation are reflected in hair cortisol concentrations (HCC). Here, we report findings from a validation study in a sample of 17 healthy adults (mean±SD age: 34±8.6 yrs). To determine the extent to which HCC captures cumulative cortisol production, we examined the correspondence of HCC, obtained from the first 1cm scalp-near hair segment, assumed to retrospectively reflect 1-month integrated cortisol secretion, with 30-day average salivary cortisol area-under-the curve (AUC) based on 3 samples collected per day (on awakening, +30min, at bedtime) and the average of 4 weekly 24-h urinary free cortisol (UFC) assessments. To further address which aspects of cortisol production and regulation are best reflected in the HCC measure, we also examined components of the salivary measures that represent: (1) production in response to the challenge of awakening (using the cortisol awakening response [CAR]), and (2) chronobiological regulation of cortisol production (using diurnal slope). Finally, we evaluated the test-retest stability of each cortisol measure. Results indicate that HCC was most strongly associated with the prior 30-day integrated cortisol production measure (average salivary cortisol AUC) (r=0.61, p=0.01). There were no significant associations between HCC and the 30-day summary measures using CAR or diurnal slope. The relationship between 1-month integrated 24-h UFC and HCC did not reach statistical significance (r=0.30, p=0.28). Lastly, of all cortisol measures, test-retest correlations of serial measures were highest for HCC (month-to-month: r=0.84, p<0.001), followed by 24-h UFC (week-to-week: r’s between 0.59 and 0.68, ps<0.05) and then integrated salivary cortisol concentrations (week-to-week: r’s between 0.38 and 0.61, p’s between 0.13 and 0.01). These findings support the contention that HCC provides a reliable estimate of long-term integrated free cortisol production that is aligned with integrated salivary cortisol production measured over a corresponding one-month period.

Dynamics of salivary immunoglobulin A and serum interleukin 6 levels in newborn calves

Mucosal immunoglobulin A (IgA) is an important component of the adaptive first line immune defense. Especially in newborn calves, where diarrheal pathogens can cause severe diseases, the adaptive mucosal immunity is crucial. Regulating local IgA production is complex. Cytokines and in particular, interleukin 6 (IL-6), are described to be main actors in this process. In vaccination trails, IL-6 is used to improve the immune response with ambiguous results. Therefore, this study investigated the influence of IL-6 on the physiological development of salivary IgA production in newborn calves. Ten clinically healthy female Holstein calves were sampled over a period of four weeks. Immunoglobulin A and IL-6 were measured in serum, colostrum, milk and saliva. In addition, to compare the mucosal immune response with the systemic immune response, immunoglobulin G was measured in serum, colostrum and milk, too, using a commercial enzyme-linked immunosorbent assay (ELISA). In order to determine the ability of newborn calves to produce IL-6 actively by themselves, the relative gene expression was analyzed in peripheral blood mononuclear cells (PBMC) using a quantitative reverse transcriptase polymerase chain reaction (qPCR). Interleukin 6 gene expression in PBMCs was detected directly after birth. A significant positive correlation between serum IL-6 and salivary IgA was found on day seven (p=0.043). Furthermore, the IL-6 serum concentration peaked on day 14 and coincided with a remarkable IgA increase in saliva (p<0.01). Therefore, IL-6 seemed to play a role during the first initialization phase of a local IgA response.

Augmentation of salivary IgA production in healthy subjects by fucoidan-agaricus mix ingestion

Abstract Fucoidan is a series of sulfated polysaccharides derived from brown algae, and have reported to have various biological activities. Previously, we demonstrated that fucoidan derived from Cladosiphon okamuranus and Undaria pinnatifida effectively augmented anti-tumor immunity in combination with Agaricus blazei mycelia extract. In this study, we evaluated the capacity of the fucoidan-agaricus mix (FAM) to enhance oral mucosal immune function. Fifteen healthy volunteers (mean age, 41.2 years old; range, 22–56 years old; 8 males, 7 females) ingested 4 capsules each containing 250 mg FAM powder every day for 12 weeks. As a result, the mean of secretory rates of salivary secretory immunoglobulin A (sIgA) tended to be increased by the FAM administration for 4 and 12 weeks as compared with the initial value. The enhanced salivary sIgA secretion was more distinctly observed in subject group whose initial values of salivary sIgA secretory rate were lower than the total average. Furthermore, the intake of FAM led to significant augmentation in the salivary sIgA secretion (by 1.3-fold) in the group of subjects under 40 years of age. On the other hand, concanavalin A-induced blastogenic response of peripheral blood mononuclear cells and serum IgA concentration was not elevated during this trial. Therefore, it was suggested that FAM stimulated functional maturation rather than expansion of B lymphocyte. The intake of FAM did not significantly affect NK cell activities. In addition, the safety of FAM consumption was confirmed because no abnormal findings were observed in general clinical tests. From the results, it was suggested that intake of FAM was useful in augmentation of oral mucosal immune defense via enhancing salivary sIgA production.

Basal salivary cortisol secretion and susceptibility to upper respiratory infection

The immunosuppressive effects of glucocorticoids (GCs) are well-established. However, whether the net effect of GC-elicited alterations in immune function is sufficient to influence a clinically relevant outcome in healthy adults has yet to be shown. The aim of the present study was to investigate whether inter-individual differences in basal salivary cortisol production are associated with increased risk and severity of infection and subsequent illness following experimental exposure to a virus that causes the common cold. The present analyses combine archival data from three viral-challenge studies. Participants were 608 healthy adults, aged 18 to 55years (49.2% female; 65.8% white), who each completed a three-day saliva collection protocol; was subsequently exposed to a virus that causes the common cold; and monitored for 5days for objective signs of infection (presence of challenge virus in nasal secretions) and clinical illness (mucus weight, mucociliary clearance time). Basal cortisol production (operationalized as the calculated area-under-the-curve averaged across the 3days) showed a graded association with infection risk, with those producing higher levels of cortisol being at greater risk. Cortisol also showed a continuous association with duration of viral shedding, an indicator of viral replication and continuing infection, such that higher cortisol concentrations predicted more days of shedding. Cortisol was not, however, related to severity of objective illness. These findings are the first to demonstrate in healthy adults an association between basal cortisol production and an objectively measured and clinically relevant infectious disease outcome.

Salivary function impairment in type 2 Diabetes patients associated with concentration and genetic polymorphisms of chromogranin A.

The purpose of this study was to evaluate the effect of type 2 diabetes mellitus (T2DM) on salivary function impairments according to glycemic control status and subsequently compare the concentration of chromogranin A (CHGA) with its genetic profile. Thirty-six patients with controlled T2DM, 36 with poorly controlled T2DM, and 38 nondiabetic subjects underwent salivary flow rate measurements by means of unstimulated labial (ULS), unstimulated whole (UWS), and stimulated whole saliva (SWS) collections. CHGA concentrations were determined in saliva and plasma with ELISA, and two CHGA polymorphisms (T-415C and Glu264Asp) were analyzed by polymerase chain reaction-restriction fragment length polymorphism. T2DM patients presented significantly lower ULS and UWS flow rates regardless of glycemic control status compared to controls (P = 0.002 and P = 0.027, respectively). The SWS flow rate in the poorly controlled T2DM was the lowest among the groups (P = 0.026). Significantly higher plasma and salivary CHGA levels were found in T2DM groups (P = 0.019 and P < 0.001, respectively). CHGA gene variants (T-415C and Glu264Asp) revealed significant differences between diabetics and control subjects when associated with lower salivary flow and higher salivary CHGA production (P < 0.05). T2DM causes abnormalities in the function of salivary glands. However, poorly controlled T2DM has the most influence on SWS flow rates. Our findings indicate an association between plasma and salivary CHGA levels and T2DM patients. Furthermore, the results suggest that CGHA polymorphisms might be associated with salivary gland hypofunction and higher salivary CHGA production in T2DM patients. Nevertheless, further epidemiological studies are required to elucidate this clinical implication. Salivary impairments and high levels of CHGA are associated with T2DM patients. In addition, CGHA polymorphisms might be associated with salivary gland hypofunction and higher salivary CHGA production in T2DM patients. This could be a significant insight to establish a role for salivary CHGA as a potential clinical biomarker to T2DM.

Acupuncture-Like Transcutaneous Electrical Nerve Stimulation Versus Pilocarpine in Treating Radiation-Induced Xerostomia: Results of RTOG 0537 Phase 3 Study

This report presents the analysis of the RTOG 0537 multicenter randomized study that compared acupuncture-like transcutaneous stimulation (ALTENS) with pilocarpine (PC) for relieving radiation-induced xerostomia. Eligible patients were randomized to twice-weekly 20-minute ALTENS sessions for 24 sessions during 12weeks or PC (5mg 3 times daily for 12weeks). The primary endpoint was the change in the University of Michigan Xerostomia-Related Quality of Life Scale (XeQOLS) scores from baseline to 9months from randomization (MFR). Secondary endpoints included basal and citric acid primed whole salivary production (WSP), ratios of positive responders (defined as patients with ≥20% reduction in overall radiation-induced xerostomia symptom burden), and the presence of adverse events based on the Common Terminology Criteria for Adverse Events version 3. An intention-to-treat analysis was conducted. One hundred forty-eight patients were randomized. Only 96 patients completed the required XeQOLS and were evaluable at 9 MFR (representing merely 68.6% statistical power). Seventy-six patients were evaluable at 15 MFR. The median change in the overall XeQOLS in ALTENS and PC groups at 9 and 15 MFR were -0.53 and -0.27 (P=.45) and -0.6 and -0.47 (P=.21). The corresponding percentages of positive responders were 81% and 72% (P=.34) and 83% and 63% (P=.04). Changes in WSP were not significantly different between the groups. Grade 3 or less adverse events, mostly consisting of grade 1, developed in 20.8% of patients in the ALTENS group and in 61.6% of the PC group. The observed effect size was smaller than hypothesized, and statistical power was limited because only 96 of the recruited 148 patients were evaluable. The primary endpoint-the change in radiation-induced xerostomia symptom burden at 9 MFR-was not significantly different between the ALTENS and PC groups. There was significantly less toxicity in patients receiving ALTENS.

Salivary α-amylase and cortisol after exercise in menopause: influence of long-term HRT

Objectives This observational prospective study analyzed the effect of an incremental cardiopulmonary exercise test (CPET) on the secretion of salivary biomarkers of the adrenergic nervous system and hypothalamus–pituitary–adrenal (HPA) axis activity by measuring salivary α-amylase and cortisol diurnal trajectories in the setting of long-term hormone replacement therapy (HRT).Methods Fifteen healthy sedentary postmenopausal women who were current HRT users and 15 women who had never used HRT were consecutively recruited. α-Amylase and cortisol were measured in salivary samples collected on the CPET day and on a rest day. Cardiovascular and respiratory fitness parameters were recorded during the CPET challenge.Results The participants had very homogeneous somatic characteristics, and they were all in generally good health. The postmenopausal never-HRT users presented an abnormal diurnal pattern of α-amylase at baseline and a flattened response to CPET. In contrast, women on HRT had a physiological α-amylase diurnal pattern and increased salivary α-amylase production during the CPET-induced challenge. The CPET challenge physiologically activated the HPA axis activity, as shown by the increase in the concentration of salivary cortisol during the effort test. HPA axis activity was not affected by long-term HRT. Postmenopausal women using HRT exhibited a cardiorespiratory functional capacity that was significantly (p < 0.05) higher than that of non-users.Conclusions Our findings show that healthy postmenopausal women present an asymmetry between adrenergic nervous system and HPA axis activities under both basal and stress conditions. HRT was able to modify the abnormal adrenergic nervous system activity, most likely by reducing the sympathetic hyperactivity that characterizes menopause.

Insights into hominin phenotypic and dietary evolution from ancient DNA sequence data

Nuclear genome sequence data from Neandertals, Denisovans, and archaic anatomically modern humans can be used to complement our understanding of hominin evolutionary biology and ecology through i) direct inference of archaic hominin phenotypes, ii) indirect inference of those phenotypes by identifying the effects of previously-introgressed alleles still present among modern humans, or iii) determining the evolutionary timing of relevant hominin-specific genetic changes. Here we review and reanalyze published Neandertal and Denisovan genome sequence data to illustrate an example of the third approach. Specifically, we infer the timing of five human gene presence/absence changes that may be related to particular hominin-specific dietary changes and discuss these results in the context of our broader reconstructions of hominin evolutionary ecology. We show that pseudogenizing (gene loss) mutations in the TAS2R62 and TAS2R64 bitter taste receptor genes and the MYH16 masticatory myosin gene occurred after the hominin-chimpanzee divergence but before the divergence of the human and Neandertal/Denisovan lineages. The absence of a functional MYH16 protein may explain our relatively reduced jaw muscles; this gene loss may have followed the adoption of cooking behavior. In contrast, salivary amylase gene (AMY1) duplications were not observed in the Neandertal and Denisovan genomes, suggesting a relatively recent origin for the AMY1 copy number gains that are observed in modern humans. Thus, if earlier hominins were consuming large quantities of starch-rich underground storage organs, as previously hypothesized, then they were likely doing so without the digestive benefits of increased salivary amylase production. Our most surprising result was the observation of a heterozygous mutation in the first codon of the TAS2R38 bitter taste receptor gene in the Neandertal individual, which likely would have resulted in a non-functional protein and inter-individual PTC (phenylthiocarbamide) taste sensitivity variation, as also observed in both humans and chimpanzees.

The Rapalogue, CCI-779, improves salivary gland function following radiation.

The standard of care for head and neck cancer typically includes surgical resection of the tumor followed by targeted head and neck radiation. However depending on tumor location and stage, some cases may not require surgical resection while others may be treated with chemoradiation. Unfortunately, these radiation treatments cause chronic negative side effects for patients. These side effects are associated with damage to surrounding normal salivary gland tissue and include xerostomia, changes in taste and malnutrition. The underlying mechanisms of chronic radiation-induced salivary gland dysfunction are unknown, however, in rodent models persistently elevated proliferation is correlated with reduced stimulated salivary flow. The rapalogue, CCI-779, has been used in other cell systems to induce autophagy and reduce proliferation, therefore the aim of this study was to determine if CCI-779 could be utilized to ameliorate chronic radiation-induced salivary gland dysfunction. Four to six week old Atg5f/f; Aqp5-Cre, Atg5+/+; Aqp5-Cre and FVB mice were treated with targeted head and neck radiation. FVB mice were treated with CCI-779, chloroquine, or DMSO post-radiation. Stimulated salivary flow rates were determined and parotid and submandibular salivary gland tissues were collected for analyses. Mice with a defect in autophagy, via a conditional knockout of Atg5 in the salivary glands, display increased compensatory proliferation in the acinar cell compartment and hypertrophy at 24-72 hours following radiation. FVB mice treated with post-therapy CCI-779 have significant improvements in salivary gland physiology as determined by stimulated salivary flow rates, proliferation indices and amylase production and secretion. Consequently, post-radiation use of CCI-779 allows for improvement of salivary gland function and reestablishment of glandular homeostasis. As CCI-779 is already FDA approved for other uses, it could have a secondary use to alleviate the chronic side effects in head and neck cancer patients who have completed anti-tumor therapy.

Significant variation in salivation by short-term suggestive intervention: a randomized controlled cross-over clinical study.

IntroductionMost dental procedures require a dry working environment. Although many evaporative drying methods are available, an additional reduction of salivary flow would often be helpful.MethodsThis prospective randomized cross-over study compares salivary production in 31 volunteers during direct, indirect, and non-suggestive (control group) intervention. Overall, each volunteer underwent four salivation measurements, i.e. two measurements during two different types of hypnotic suggestion (indirect and direct) arranged in random order and two control sections. All four measurements were conducted successively.ResultsBoth suggestive methods significantly reduced salivary production in comparison to the two control sections (direct suggestion Δ = 1.46 grams per 5 min, p < 0.001, indirect suggestion Δ = 0.94 grams per 5 min, p = 0.039). Direct suggestion showed a significantly higher reduction of salivary production than indirect suggestion (Δ = -0.53 grams per 5 min, p = 0.001).ConclusionsHypnotic suggestion represents a simple and inexpensive method to reduce salivation and could thus create a better working environment for more comfortable dental treatments for both patients and dentists.

MyD88 deficiency alters expression of antimicrobial factors in mouse salivary glands.

The surfaces of oral mucosa are protected from infections by antimicrobial proteins and natural immunoglobulins that are constantly secreted in saliva, serving as principal innate immune defense in the oral cavity. MyD88 is an important adaptor protein for signal transduction downstream of Toll-like receptors and TACI, receptors for regulation of innate immunity and B cell responses, respectively. Although MyD88-mediated signaling has a regulatory role in the intestinal mucosal immunity, its specific role in the oral cavity has remained elusive. In the present study, we assessed the influence of MyD88 deficiency on the oral innate defense, particularly the expression of antimicrobial proteins in salivary glands and production of salivary basal immunoglobulins, in mice. Microarray analysis of the whole tissues of submandibular glands revealed that the expression of several genes encoding salivary antimicrobial proteins, such as secretory leukocyte peptidase inhibitor (SLPI), S100A8, and lactotransferrin, was reduced due to MyD88 deficiency. Histologically, SLPI-expressing acinar cells were evidently decreased in the glands from MyD88 deficient mice compared to wild-type mice. Flow cytometric analysis revealed that B cell populations, including B-1 cells and IgA+ plasma cells, residing in submandibular glands were increased by MyD88 deficiency. The level of salivary anti-phosphorylcholine IgA was elevated in MyD88 deficient mice compared to wild-type mice. Thus, this study provides a detailed description of the effect of MyD88 deficiency on expression of several salivary antimicrobial factors in mice, illustrating the role for MyD88-mediated signaling in the innate immune defense in the oral cavity.