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Aquaporins (AQPs) are a family of channel proteins that allow water or very small solutes to pass, functioning in tissues where the rapid and regulated transport of fluid is necessary, such as the kidney, lung, and salivary glands. Aquaporin-5 (AQP5) has been demonstrated to localize on the luminal surface of the acinar cells of the salivary glands. In this paper, we investigated the expression and function of AQP5 in the secretory granules of the rat parotid gland. AQP5 was detected in the secretory granule membranes by immunoblot analysis. The immunoelectron microscopy experiments confirmed that AQP5 was to be found in the secretory granule membrane. Anti-AQP5 antibody evoked lysis of the secretory granules but anti-aquaporin-1 antibody did not and AQP1 was not detected in the secretory granule membranes by immunoblot analysis. When chloride ions were removed from the solution prepared for suspending secretory granules, the granule lysis induced by anti-AQP5 antibody was inhibited. Furthermore, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, an anion channel blocker, blocked the anti-AQP5 antibody-induced secretory granule lysis. These results suggest that AQP5 is, expressed in the parotid gland secretory granule membrane and is involved in osmoregulation in the secretory granules. [ABSTRACT FROM AUTHOR]

Background: The role of the salivary glands in the maintenance of nitrate and nitrite in saliva is poorly understood. The aim was to study alterations of nitrate and nitrite metabolisms in patients with Sjogren's syndrome (SS) or sialosis.Methods: Saliva, serum, and urine samples were collected from healthy volunteers (n = 29), patients with SS (n = 31), and patients with sialosis (n = 30). Concentrations of nitrate and nitrite were determined by high-performance liquid chromatography (HPLC).Results: In the healthy group, the highest concentration of nitrate was found in parotid saliva (172 mg/l), followed by urine (160 mg/l), whole saliva (97 mg/l), and serum (33 mg/l). In the SS group, concentration of nitrate was decreased in parotid saliva and whole saliva, and increased significantly in urine. Concentration of nitrite in whole saliva was significantly decreased in the SS group and increased in the sialosis group.Conclusion: Hypofunction of the salivary glands is associated with significant changes of nitrate and nitrite levels in the saliva and urine. [ABSTRACT FROM AUTHOR]

Background and purpose: To evaluate (1) parotid function, (2) subjective xerostomia and (3) pattern of relapses after conformal parotid-sparing radiotherapy (RT) for head and neck cancer. (4) To study dose–response curves of parotid glands.Material and methods: From September 1999 to November 2000, 39 head and neck cancer patients requiring bilateral neck RT were treated with a fairly simple conformal RT technique (three-field set-up+anterior lower neck field; two opposed oblique boost fields). The contralateral parotid was spared. Parotid function was assessed by salivary gland scintigraphies performed before, early (median 4 weeks) and late (median 28 weeks) after RT. Xerostomia was monitored by visual analogue scales (VAS) and LENT SOMA scores. Location of locoregional recurrences was studied in relation to the radiation fields. A dose–response curve of parotids was created using logistic regression.Results: (1) Early after RT, on salivary gland scintigraphy, the mean loss of secretion function in the spared parotid was 67% and total in the non-spared. Late after RT, the mean loss remained 19% in the spared and total in the non-spared parotid. Normal excretion function was regained in 75% of the spared parotids. (2) Late after RT, 78% of patients had no, minimal or acceptable subjective xerostomia. (3) No recurrence was seen near the spared parotid (11/39 locoregional recurrences). (4) The dose–response curve of parotids showed that the mean parotid dose should preferentially be ≤20 Gy, to obtain a good chance (≥70%) for preservation of its function on scintigraphy.Conclusions: An easy conformal parotid-sparing RT technique prevents moderate or severe subjective xerostomia in 78% of patients. In the spared parotids, nearly complete to complete recovery is obtained after 6–12 months. [Copyright &y& Elsevier]

Investigates the relationship between Na/H exchanger isoform (NHE1) and the response of parotid glands to beta-adrenergic agonists in mice. Enhanced expression of NHE1 transcripts after beta-adrenergic receptor stimulation; Parotid gland morphology; Increase of Na/H ion exchanger activity after beta adrenergic receptor stimulation.

Oral dryness causes significant health problems both functional (difficulty speaking, chewing and swallowing) and structural in teeth (increased number of infections) and oral mucosa. The main objective of this study is to show an alternative treatment to help stimulate the salivary secretion thus improving the quality of life of the patient. In this study, a salivary stimulation equipment using vibrotactile stimuli is shown. The system has been placed bilaterally in the parotid glands and assessed the efficacy of the salivary secretion by sialometry before and after the stimulation. The new proposal is capable of stimulating salivary secretion, in a significative way after 7 minutes of use, at least in the cases analyzed, and fulfills low-cost, easy-to-use, and safe technical restrictions. In this setting, this paper suggests the performance of a deep clinical trial to measure the exact efficacy of the prototype and the times and frequencies needed to state the optimal treatment depending in each case., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Francisco Gómez-García et al.)

Presents information on a study which examined the influence of age on the variability of parotid salivary gland flow rates. Methodology; Results of the study; Discussion.

The parotid–masticatory salivary reflex has been studied in edentulous subjects. Salivary flow was recorded by siting a modified Lashley cup over the orifice of the parotid duct on one side of the mouth. Subjects chewed on small pieces of silicone rubber with their complete dentures for 1 min periods which resulted in a reflex secretion of parotid saliva. The secretion was greatest when the subject chewed on the same side of the mouth (ipsilateral) as the salivary flow was recorded. Less salivary flow resulted when the subjects chewed on the opposite side of the mouth (contralateral). Anaesthesia of the mucosa of the maxillary and mandibular denture‐bearing area was achieved by placing a thin layer of anaesthetic ointment in the fitting surface of the dentures on the side ipsilateral to the Lashley cup. This resulted in a reduction of salivary flow in response to similar chewing cycles. The results confirmed the presence of a parotid–masticatory salivary reflex in edentulous subjects which appears similar in many respects to that of dentate subjects. It is likely that receptors in the oral mucosa are stimulated when an edentulous subject masticates with complete dentures and that activity in these mechanoreceptive neurones results in the reflex salivary secretion. [ABSTRACT FROM AUTHOR]

Focuses on a study which described experiments indicating the suitability of one of the parotid gland cell lines, Par-C10, in Ussing chamber studies. Methodology used on cell culture, morphological evaluation and measurement of short-circuit current in Par-C10 monolayers; Elaboration on the results; Conclusion.

Assesses the effects of chronic beta-adrenergic antagonists on parotid and submandibular gland secretions in men and women at different ages. Effects on unstimulated parotid secretions; Effects on stimulated parotid secretions; Effects on unstimulated submandibular glandular secretions; Effects on stimulated submandibular secretions.

Describes the developmental regulation and maintenance of inwardly and outwardly rectifying potassium currents in sheep parotid cells. Secretory cells from lamb parotid glands; Activity of inward rectifier; Whole cell currents in thev secretory cells of the contralateral control gland.

Investigates the transport properties of rat parotid intralobular (striated) ducts. Secretagogue-induced mobilization of intracellular Ca2+; Evidence for presence of an epithelial-type Na+-H+ exchanger; Evidence for regulation of ductal Na+-H+ exchanger.

Investigates the parotid and submandibular gland for the ability to respond to beta-adrenergic receptor stimulation in the nonobese diabetic mouse. Measurement of physiological responses to beta-agonist stimulation; Amount of adenosine 3',5'-cyclic monophosphate; Confirmation of autoantibodies to beta-adrenergic receptor; Changes in membrane density.

Investigates the mechanisms involved in the regulation of phospholipase D (PLD) activity in the rat parotid gland. Preparation and labeling of parotid acini; Role of protein kinase C and calcium in PLD regulation; Lipid analysis; Measurement of inositol phosphate production; Transphosphatidylation reaction catalyzed by PLD; Pathways of PLD activation.

Assesses the presence of spare muscarinic cholinergic receptors (mAChRs) in rat parotid gland. Effect of propylbenzilylcholine mustard (PBCM) on agonist-stimulated inositol triphosphate (IP3) formation; Equilibrium constants for the activation of mAChRs; Reduction in mAChR number after PBCM treatment.

Presents information on a study which determined the effect of body dehydration upon parotid salivary flow rates in young and older healthy adults. Methods used; Results; Conclusions.

Background: Early studies suggested that salivary gland dysfunction was a normal sequela of aging. Recent research on healthy, different-aged adults has led to a revision of these former conclusions. Parotid gland function appears to be age-stable, yet there is no consensus on submandibular/sublingual output. To date, there have only been two longitudinal studies utilizing healthy individuals examining parotid function, and no published longitudinal studies on submandibular/sublingual output. The purpose of this study was to examine unstimulated and stimulated major salivary gland flow rates in unmedicated, essentially healthy subjects, over a 3-year period.Methods: Thirty-seven males and females, aged 26-90 years of age, were examined twice over a 3-year period at the Clinical Center of the National Institutes of Health. All were healthy, community-dwelling adults, without systemic diseases, and not taking any medications. Unstimulated and 2% citrate-stimulated parotid and submandibular/sublingual salivary gland flow rates were assessed at both visits, and changes over time were evaluated according to the subject's age at initial visit.Results: There were no significant flow rate differences over a 3-year time period for unstimulated and stimulated parotid and submandibular/sublingual flow rates.Conclusions: Major salivary gland output is aged-stable in healthy persons over a 3-year period. The data from this study suggest that salivary gland dysfunction in an older person should not be considered a normal process of aging. [ABSTRACT FROM AUTHOR]

Compares the ability of a population of healthy young and old individuals to secrete saliva from a parotid and submandibular glands for an extended period of time under conditions of intense gustatory stimulation. Association of diminished salivary output with a host of oral and systemic sequelae; Materials and methods used in the study.

Assesses the role of protein phosphorylation in the regulation of Ca2+ entry in rat parotid gland acinar cells. Preparation of dispersed parotid acini and fura 2 loading; Effects of okadaic acids and pervanadate on carbachol and thapsigarin-stimulated Ca2+ mobilization; Effects of phosphatase inhibitors on thapsigarin stimulation of manganese.

Focuses on the capability of mouse parotid acinar cells to synthesize IL-1beta and IL-6 and to release the cytokines from their granules after alpha- and beta-adrenergic stimulation. In situ hybridization of IL-1beta and IL-6 mRNA in parotid gland; Release of IL-1beta, IL-6, and amylase from parotid acinar cells; Ultrastructure localization of IL-1beta and IL-6.

Studies the structural localization of transforming growth factor-alpha (TGF-alpha) in the rat parotid gland. Use of postembedding immunoelectron microscopy to show the presence of TGF-alpha in acinar and intercalated duct granules; Labeling density calculations; Homogenization of parotid glands.

Discusses the effects of condensed tannins from faba beans on the size of the parotid glands of rats and on the production and secretion of proline-rich proteins and individual amino acids. Feeding trials; Determination of apparent digestibility values; Calculation of the quantitative secretion of proline-rich proteins by the parotid glands.

Unstimulated and chewing-stimulated whole saliva samples were obtained from 42 healthy Caucasians; 21 were between 18 and 35 years of age, and 21 between 65 and 83 years of age. The unstimulated salivary flow rate was significantly lower in the aged group, but the stimulated flow rate was significantly higher in the aged than in the young group. Both groups showed significantly increased flow during salivary stimulation. MG1 and MG2 concentrations in unstimulated and stimulated saliva samples were significantly lower in the aged group. There were no significant correlations between salivary flow rates and MG1 and MG2 concentrations. [ABSTRACT FROM AUTHOR]

The article discusses the physiological factors that impact the salivary flow rate, oral sugar clearance, and dry mouth (xerostomia) sensation in a human being, and it mentions methods for collecting whole saliva and individual gland secretions. Gustatory stimulation involving acid is addressed, along with chewing methods, the collection of submandibular and parotid gland saliva, and the removal of carbohydrates from the mouth. Water absorption by the oral mucosa is assessed.

Two ultrasensitive methods were employed to determine the effect of repeated in vivo stimulation with isoproterenol on the protein composition of parotid acinar cells. Silver staining showed electrophoretic banding pattern changes in a wide range of cellular proteins during and after multiple injections of the β-adrenergic agonist. Photo-affinity labeling with [32P]-N3-cyclic AMP showed the disappearance and eventual return (after discontinuation of the injections) of the cellular cyclic AMP-binding proteins as measurable cellular components. These findings indicate that major translation-associated changes may occur in target cell protein composition both during and after hormonal stimulation. [ABSTRACT FROM AUTHOR]

Monolayers of feline parotid acinar cells were infected with feline rhinotracheitis herpes virus. Membrane potentials and input resistances were measured before and during infection. Uninfected acinar cells had an average membrane potential of -51 mV and resistances from 6 to 120 mega-ohms; cells infected for more than 18 h had an average membrane potential of -19 mV and resistances from 30 to 100 mega-ohms. The time course of the decrease in membrane potential was studied and was found to commence about ten to 14 h after infection. [ABSTRACT FROM AUTHOR]

Previous studies have shown that the whole-cell current-voltage (I-V) relation of unstimulated sheep parotid cells is dominated by two K+ conductances, one outwardly and the other inwardly rectifying. We now show that once these K+ conductances are blocked by replacement of pipette K+ with Na+ and by the addition of 5 mmol/liter CsCl to the bath, there remains an outwardly rectifying conductance with a reversal potential of 0 mV. Replacement of 120 mmol/liter NaCl in the pipette solution with an equimolar amount of Na-glutamate shifted the reversal potential of this residual current to -55 mV, indicating that the conductance was Cl- selective. The Cl- current was activated by increasing the free Ca2+ in the pipette solution from 10 to 100 nmol/liter. When the Ca2+ concentration in the pipette solution was 10 nmol/liter, the relaxations observed in response to membrane depolarization could be fitted with a single exponential, whose time constant increased from 81 to 183 ms as the pipette potential was increased from -30 to +60 mV. Relaxation analysis showed that the current was activated by membrane depolarization. Reversal potential measurements in experiments in which external Cl- was replaced with various anions, gave the following relative permeabilities: SCN- (1.80) > I- (1.09) > Cl- (1) > NO3- (0.92) > Br- (0.75). The relative conductances were: SCN- (2.18) > I- (1.07) > Cl- (1.00) > Br- (0.91) > NO3- (0.50). The Cl- current was blocked by NPPB (ID50 approximately 10 microM), DIDS (10 or 30 mumol/liter) and furosemide (100 mumol/liter). [ABSTRACT FROM AUTHOR]

This study examines the effect of membrane potential on divalent cation entry in dispersed parotid acini following stimulation by the muscarinic agonist, carbachol, and during refill of the agonist-sensitive internal Ca2+ pool. Depolarizing conditions (addition of gramicidin to cells in Na(+)-containing medium or incubation of cells in medium with elevated [K+]) prevent carbachol-stimulated hyperpolarization of acini and also inhibit carbachol activation of Ca2+ and Mn2+ entry into these cells. Conditions promoting hyperpolarization (cells in medium with Na+ or with N-methyl-D-glucamine instead of Na+) enhance carbachol stimulation of divalent cation entry. Intracellular Ca2+ release (initial increase in [Ca2+]i) does not appear to be affected by these manipulations. Mn2+ entry into resting and internal Ca2+ pool-depleted cells (10-min carbachol stimulation in a Ca(2+)-free medium) is similarly affected by membrane potential modulations, and refill of the internal pool by Ca2+ is inhibited by depolarization. The inhibitory effects of depolarization on divalent cation entry can be overcome by increasing extracellular [Ca2+] or [Mn2+]. These data demonstrate that the modulation of Ca2+ entry into parotid acini by membrane potential is most likely due to effects on the electrochemical gradient (Em-ECa) for Ca2+ entry. [ABSTRACT FROM AUTHOR]

α-L-Fucosidase acting on naturally occurring substrates was highly purified from the growth culture of Streptococcus sanguis ATCC 10557. The molecular weight of the enzyme was approximately 120,000 and the optimal pH was at 5.5. The purified enzyme showed specificity toward the linkage of α-(1→2) fucosides in oligosaccharides and glycoproteins. The enzyme released L-fucose from glycoprotein in human parotid saliva. [ABSTRACT FROM AUTHOR]

The role of cGMP as the intracellular mediator of the activation of cholinergic receptors in the secretory cells of the rat parotid gland was investigated in vitro using isolated rat parotid acinar cells. It was demonstrated that this cyclic nucleotide is involved in the intracellular translation of activation of muscarinic cholinergic receptors in these cells. [ABSTRACT FROM AUTHOR]

This article discusses research into the saliva flow rates from the parotid gland of caries resistant men. The possible relationship between saliva flow and caries resistance is explored. Although this flow rate of saliva is not believed to be a diagnostic tool in the identification of caries risk, there is a correlation between saliva flow rate and caries incidence.

This article discusses the effects of hyperhydration on the flow of saliva from the parotid salivary gland. The process for collecting and analysing the flow of parotid fluid during the forced ingestion of water is described. The researchers found a significant increase in the salivary flow rate resulted from the forced consumption of water.

This article discusses research into the calcium content of dog saliva. The use of radioactive calcium as a tracer to indicate the flow of calcium through the bodies of dogs and determine its path of incorporation into saliva is described. The concentration of saliva in the blood and the saliva of dogs following the administration of pilocarpine was compared.

This article discusses research into the concentration of blood group substances in different salivary glands of human beings. Measures of blood-group-substance titers such as erythrocytes and antibodies that indicate different blood types are described. The authors found that these titers were most concentrated in the sublingual salivary glands and least concentrated in parotid saliva.

Abstract: Serous granules in the human parotid gland have a well-defined substructure, consisting of a dense spherule suspended in a moderately dense matrix. Immunogold labeling with an antibody against carbonic anhydrase VI revealed that this enzyme is localized within the matrix and is absent from the spherule. This location matches that of a number of other salivary gland proteins. Cell organelles involved in the secretory pathway are devoid of label. Labeling was not observed in any ductular component of the gland. [Copyright &y& Elsevier]

Aims: Salivary gland dysfunction is a common complication of diabetes mellitus (DM). Long non-coding RNA (lncRNA) is evidenced to involve in the functional regulation of salivary gland, however, its role in DM-impaired gland is unknown. Therefore, this study aimed to investigate the expression profiles and functional networks of lncRNA in the parotid glands (PGs) of DM mice., Main Methods: Microarray was used to detect lncRNA and messenger RNA (mRNA) expression profiles in the PGs from db/db and db/m mice. Eleven differently expressed (DE) lncRNAs validated by qRT-PCR were selected for coding-non-coding gene co-expression (CNC) and competing endogenous RNA (ceRNA) network analysis, as well as the following Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Pearson's coefficient correlation analysis was used to analyze the correlations between DE lncRNAs expression and DM pathology., Key Findings: By using a 2-fold change and P < 0.05 as the cutoff criteria, 1650 DE lncRNAs (758 upregulated and 892 downregulated) and 1073 mRNAs (563 upregulated and 510 downregulated) were identified in the PGs of db/db mice compared to db/m mice. GO and KEGG analysis of DE mRNA suggested that activated inflammation response and downregulated ion transport might count for the dysfunction of diabetic PG. CNC and ceRNA networks analysis of 11 DE lncRNAs showed that the inflammation process and its related signaling pathways including advanced glycation end product (AGE)-receptor for AGE (RAGE) signaling pathway in diabetic complications, cytokine-cytokine receptor interaction, chemokine signaling pathway, apoptosis, and cell adhesion molecules were significantly enriched. The alterations of lncRNAs were closely correlated with higher blood glucose and serum insulin levels in mice., Significance: We identified multiple lncRNAs/mRNAs and several signaling pathways that may involve in the pathogenesis of diabetic salivary injury, providing new insight into potential target of diabetic hyposalivation., (Copyright © 2020. Published by Elsevier Inc.)

If optimal investment in anti-predator defences depends on predation risk, invading new regions (and thus, encountering different predators) may favour shifts in that investment. Cane toads offer an ideal system to test this prediction: expensive anti-predator toxins are stored mainly in parotoid glands whose dimensions are easy to measure, and toad invasions have changed the suites of predators they encounter. Although plasticity may influence parotoid morphology, comparisons between parents and progeny revealed that gland dimensions were highly heritable. That heritability supports the plausibility of an evolved basis to variation in gland dimensions. Measurements of 3779 adult toads show that females have larger glands than males, invasive populations have larger glands than in the native-range, and that parotoid sexual size dimorphism varies strongly among invaded areas. Geographic variation in parotoid morphology may be driven by predation risk to both adult toads and offspring (provisioned with toxins by their mother), with toxins allocated to eggs exacerbating the risk of cannibalism but reducing the risk of interspecific predation. Investment into chemical defences has evolved rapidly during the cane toad's international diaspora, consistent with the hypothesis that organisms flexibly adjust resource allocation to anti-predator tactics in response to novel challenges.

Anurans secrete a wide diversity of toxins from skin glands to defend themselves against predators and pathogens. Bufonids produce potent poison in parotoid macroglands located in the postorbital region. Parotoid secretion is a rich source of bioactive compounds with cardiotoxic, cytotoxic and hemolytic activity. Poison content and toxicity may vary between species, populations, and among conspecifics inhabiting the same area. In the present paper, we pre-analyzed the individual variation in cardiotoxicity of parotoid extract of common toads (Bufo bufo Linnaeus, 1758) and impact of body mass (BM), snout to vent length (SVL), and body condition (BC) of toad on the poison toxicity. We hypothesized that large toads produce poison with higher cardiotoxicity than smaller ones. Parotoid extract was fractionated by reverse phase chromatography, and then in vitro physiological bioassays were carried out on the semi-isolated hearts of the mealworm beetle (Tenebrio molitor Linnaeus, 1758) to determine cardiotoxicity of the whole poison and separated fractions. Generalized linear mixed models were used to determine effects of BM, SVL, and BC on the poison toxicity. We recorded significant changes in the insect heart contractility after treatment with the whole poison and separated fractions. We found an individual variation in cardiotoxicity of the parotoid extract which was explained by the body size of toad. Poison of smaller toads displayed a negative, whereas poison of larger toads positive, chronotropic effect on the heart contractility. Thus, we conclude that the effectiveness of parotoid secretion in repelling predators may vary depending on the toad individual size., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Presents case reports on bulimia and associated benign bilateral painless parotid enlargement in several young women. Discussion on nutritional disorders; Medical history of patients; Clinical manifestations and treatment.

The unstimulated parotid saliva flow rate decreased significantly from 0.057 to 0.014 ml/minute when subjects were blindfolded. It is suggested that photic stimulation of retinal receptors induces sympathetic neuronal activity, which may be responsible for maintaining resting parotid flow in the human. [ABSTRACT FROM AUTHOR]

The parotoid gland of bufonids is characterized as a specialized integument region, formed by different gland types. The secretion elaborated by the largest glandular alveoli has been related to animal chemical defense and is constituted by granular protein content, associated with a basophilic and alcianophilic material with features of glycoconjugates. This study aimed to identify and characterize the glycoconjugates in the secretion of the largest granular gland of the parotoid gland of Rinella icterica by histochemical and immunohistochemical techniques at light microscopy, biochemical methods, and nuclear magnetic resonance spectroscopy. Our results showed that the glycoconjugate content contains a mixture of chondroitin‑6‑sulfate (C6S) and chondroitin-non-sulfate (C0S). Thus, chondroitin sulfate probably plays an important role in gland physiology, probably protecting the protein content while inside the secretory portion., (Copyright © 2018. Published by Elsevier B.V.)

The current study was conducted on a menopause rat model induced by ovariectomy to assess the histological and immunohistochemical alterations in the parotid glands and to verify the efficiency of human umbilical cord derived-mesenchymal stromal cell (hUCB-MSCs) in treating this condition. Eighteen adult female rats were equally divided into three groups: sham-operated (SHAM), ovariectomized (OVX) and OVX injected with hUCB-MSCs (OVX+hUCB-MSCs). At 3months post-ovariectomy, the salivary flow rate and size of the parotid glands were measured. The parotid glands were histologically investigated via H&E stained sections. Furthermore, immunohistochemical analysis for human CD105, human CD34, proliferating cell nuclear antigen (PCNA), single strand DNA (ssDNA), caspase 3, aquaporin (AQP)1, α-smooth muscle actin (α-SMA) and mouse CD34 were performed. The OVX group showed interstitial hemorrhage, dispersed acini and intracytoplasmic vacuoles in the acinar cells. Furthermore, immunohistochemical staining revealed a significant decrement in the number of ssDNA positive apoptotic cells, but a significant increment of PCNA positive proliferating cells, AQP1 positive blood capillaries, α-SMA positive myoepithelial cells and endogenous CD34 positive hematopoietic progenitor cells in the OVX+hUCB-MSCs group as compared with the OVX group. These findings suggest a potential regenerative therapy of MSCs to injured parotid gland structures. However, further investigations are required to illustrate the mechanism of hUCB-MSCs mediated parotid gland regeneration., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Tissue elasticity is becoming a more commonly used parameter in evaluation of parenchyma in inflammatory diseases. Considering the changes in the thyroid and salivary glands with adolescence, determination of mean elasticity ranges with a function of age is necessary to apply ultrasound elastography more widely in the pediatric population.The thyroid, submandibular, and parotid glands of 127 healthy volunteers (66 males, 61 females; mean age = 10.3 ± 3.9 years; range = 3-17 years) were evaluated with shear-wave elastography.The mean elasticity values for the thyroid, submandibular, and parotid glands were 14.6 ± 3.3, 11.8 ± 2.2, and 11.8 ± 2.6 kPa, respectively. There was a significant positive correlation between age and elasticity of the thyroid, submandibular, and parotid glands. There was a significant correlation between age and elasticity value of the thyroid gland adjusted for weight and height.This study provided the baseline quantitative elasticity measures of thyroid, submandibular, and parotid glands, which would be a reference for upcoming studies. In addition, an increase in elasticity value in thyroid gland as a function of age independent of change in weight and height was demonstrated.

Background: We developed a method to quantify the volume flow rate (VFR) using the time-spatial labeling inversion pulse (Time-SLIP) technique to evaluate salivary function., Purpose/hypothesis: To investigate the accuracy of quantification of the salivary VFR using the Time-SLIP technique in phantoms and to examine the feasibility of its use in human subjects., Study Type: This was a prospective phantom and volunteer study., Population/subjects/phantom/specimen/animal Model: A phantom and 23 normal volunteers who fasted at least 2 hours study was performed., Field Strength/sequence: Flow images of the phantom and the parotid duct of 23 volunteers were acquired on a 3T-MRI scanner using the Time-SLIP technique., Assessment: Hypothesizing that flow aggregates in the conducting duct, we measured the VFR on flow images. In the phantom study, the actual VFR (slow, medium, fast flow) was controlled by an automatic pump system and the measured VFR was compared with the actual VFR on flow images. In the human study we injected citric acid into the mouth of healthy volunteers to stimulate saliva secretion and recorded the VFR., Statistical Tests: As this study was a feasibility study, statistical tests were not performed., Results: In the phantom study, the VFR at slow, medium, and fast flow was 5.7 ± 0.4 (SD), 8.4 ± 0.3, and 12.2 ± 1.1 mm 3 /sec, respectively. The error between the measured and actual VFR values was 2.8-3.7%. Salivary flow in the parotid duct was visualized in 22 of the 23 volunteers. The mean VFR was 8760 mm 3 /10 min., Data Conclusion: When salivary flow was stimulated with citric acid in normal volunteers, the salivary VFR could be obtained using the Time-SLIP technique., Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:928-935., (© 2017 International Society for Magnetic Resonance in Medicine.)

The plasma membrane of parotid acinar cells is functionally divided into apical and basolateral regions. According to the current model, fluid secretion is driven by transepithelial ion gradient, which facilitates water movement by osmosis into the acinar lumen from the interstitium. The osmotic gradient is created by the apical Cl - efflux and the subsequent paracellular Na + transport. In this model, the Na + -K + pump is located exclusively in the basolateral membrane and has essential role in salivary secretion, since the driving force for Cl - transport via basolateral Na + -K + -2Cl - cotransport is generated by the Na + -K + pump. In addition, the continuous electrochemical gradient for Cl - flow during acinar cell stimulation is maintained by the basolateral K + efflux. However, using a combination of single-cell electrophysiology and Ca 2+ -imaging, we demonstrate that photolysis of Ca 2+ close to the apical membrane of parotid acinar cells triggered significant K + current, indicating that a substantial amount of K + is secreted into the lumen during stimulation. Nevertheless, the K + content of the primary saliva is relatively low, suggesting that K + might be reabsorbed through the apical membrane. Therefore, we investigated the localization of Na + -K + pumps in acinar cells. We show that the pumps appear evenly distributed throughout the whole plasma membrane, including the apical pole of the cell. Based on these results, a new mathematical model of salivary fluid secretion is presented, where the pump reabsorbs K + from and secretes Na + to the lumen, which can partially supplement the paracellular Na + pathway.

Previous studies revealed high incidence of acquired N-glycosylation sites acquired N-glycosylation sites in RNA transcripts encoding immunoglobulin heavy variable region (IGHV) 3 genes from parotid glands of primary Sjögren's syndrome (pSS) patients. In this study, next generation sequencing was used to study the extent of ac-Nglycs among clonally expanded cells from all IGVH families in the salivary glands of pSS patients. RNA was isolated from parotid gland biopsies of five pSS patients and five non-pSS sicca controls. IGHV sequences covering all functional IGHV genes were amplified, sequenced, and analyzed. Each biopsy recovered 1,800-4,000 unique IGHV sequences. No difference in IGHV gene usage was observed between pSS and non-pSS sequences. Clonally related sequences with more than 0.3% of the total number of sequences per patient were referred to as dominant clone. Overall, 70 dominant clones were found in pSS biopsies, compared to 15 in non-pSS. No difference in percentage mutation in dominant clone-derived IGHV sequences was seen between pSS and non-pSS. In pSS, no evidence for antigen-driven selection in dominant clones was found. We observed a significantly higher amount of ac-Nglycs among pSS dominant clone-derived sequences compared to non-pSS. Ac-Nglycs were, however, not restricted to dominant clones or IGHV gene. Most ac-Nglycs were detected in the framework 3 region. No stereotypic rheumatoid factor rearrangements were found in dominant clones. Lineage tree analysis showed in four pSS patients, but not in non-pSS, the presence of the germline sequence from a dominant clone. Presence of germline sequence and mutated IGHV sequences in the same dominant clone provide evidence that this clone originated from a naïve B-cell recruited into the parotid gland to expand and differentiate locally into plasma cells. The increased presence of ac-Nglycs in IGHV sequences, due to somatic hypermutation, might provide B-cells an escape mechanism to survive during immune response. We speculate that glycosylation of the B-cell receptor makes the cell sensitive to environmental lectin signals to contribute to aberrant B-cell selection in pSS parotid glands.

Objective: To evaluate the early changes in the apparent diffusion coefficient (ADC) of the salivary glands during radiotherapy (RT) and their association with the degree of xerostomia at 6 months after RT in patients with nasopharyngeal carcinoma (NPC)., Materials and Methods: We enrolled 26 patients with NPC who underwent RT. Each patient underwent diffusion-weighted MRI of the salivary glands at rest and with gustatory stimulation within 1 week before RT and 2 weeks after the beginning of RT. The ADC at rest (ADC R ) and increase and increase rate with stimulation (ADC I , ADC IR ) of the submandibular and parotid glands were calculated. The differences in the variables' values between 2 weeks after the beginning of RT and baseline (ΔADC R , ΔADC I , and ΔADC IR ) were compared to the degree of xerostomia at 6 months after RT., Results: The ADC R of the submandibular and parotid glands were both significantly higher at 2 weeks after the beginning of RT than found at baseline (both p < 0.01). The ADC I and ADC IR for the parotid glands were both significantly lower at 2 weeks after the beginning of RT than found at baseline (both p < 0.01). ΔADC I and ΔADC IR of the parotid glands were associated with the degree of xerostomia at 6 months after RT ( r = -0.61 and -0.72, both p < 0.01)., Conclusion: The ADCs of the salivary glands change early during RT. The differences in the ADC increase and increase rate of the parotid glands between 2 weeks after the beginning of RT and baseline were associated with the degree of xerostomia at 6 months after RT.

Objectives: Dental microwear is a promising tool to reconstruct animals' diet because it reflects the interplay between the enamel surface and the food items recently consumed. This study examines the sources of inter-individual variations in dietary habits in a free-ranging population of mandrills (Mandrillus sphinx) using a combination of feeding monitoring and in vivo dental microwear textural analysis (DMTA)., Methods: We investigated the impact of seasonality and individual traits on four DMTA parameters. In parallel, we further studied the influence of the physical properties of the food items consumed on these four parameters, using three proxies (mechanical properties, estimates of phytolith and external grit contents)., Results: We found that seasonality, age, and sex all impact DMTA parameters but those results differ depending on the facet analyzed (crushing vs. shearing facets). Three DMTA parameters (anisotropy, complexity, and heterogeneity of complexity) appear sensitive to seasonal variations and anisotropy also differs between the sexes while textural fill volume tends to vary with age. Moreover, the physical properties of the food items consumed vary seasonally and also differ depending on individual sex and age., Conclusion: Considering the interplay between the tested variables and both dental microwear and diet, we reaffirm that food physical properties play a major role in microwear variations. These results suggest that DMTA parameters may provide valuable hints for paleoecological reconstruction using fragmentary fossil dental remains., (© 2017 Wiley Periodicals, Inc.)