Kayoko Ito

Intense correlation between protein-conjugated acrolein and primary Sjögren's syndrome

BACKGROUND We recently found that an increased plasma concentration of protein-conjugated acrolein is a good biomarker for stroke. Therefore we determine whether the concentration of protein-conjugated acrolein is increased in saliva from patients with primary Sjögrens syndrome. METHODS Stimulated whole-mixed saliva was collected from 10 patients and 13 control subjects. The concentration of protein-conjugated acrolein in saliva and plasma was measured by either Western blotting or enzyme-linked immunosorbent assay. RESULTS The concentration of protein-conjugated acrolein, especially albumin-conjugated acrolein, was greatly increased in saliva from patients with primary Sjögrens syndrome (p<0.001). The concentration of protein-conjugated acrolein was inversely correlated with the flow rate of saliva. CONCLUSION The results indicate that the concentration of protein-conjugated acrolein, a marker of cell or tissue damage, in saliva is well correlated with seriousness of primary Sjögrens syndrome.

The effect of food consistency and dehydration on reflex parotid and submandibular salivary secretion in conscious rats

Changes in salivary secretion with different consistency of diet and dehydration were studied in male Wistar rats under unrestricted conditions. To measure the salivary secretion, a stop-flow method was used. There was little unstimulated salivary secretion from the parotid and submandibular glands, but eating solid, powdered, and liquid diets induced parotid and submandibular saliva. There was no significant change in the volume and flow rate of saliva in bilateral parotid glands during the eating of solid diets. The solid and powdered diets induced significantly more salivary secretion from the parotid gland than did the liquid. The salivary flow rate with solid diets was significantly greater from the parotid gland than from the submandibular. On the other hand, the salivary flow rate with the liquid diet was significantly smaller from the parotid gland than from the submandibular. Appreciable amounts of submandibular saliva, but little parotid saliva were secreted during grooming. Clearly, parotid and submandibular saliva have different roles in the rat. When injected intraperitoneally with 1.5 M NaCl solution or water-deprived for 24 h, rats took longer to eat the solid diets, and had increased salivary volume and decreased flow rate from the parotid gland. These results indicate that the moisture content of the diet and the dryness of the mouth alters the volume of parotid saliva secreted in rats and show that parotid saliva plays an important part in mastication and swallowing.

Relationships between the amount of saliva and medications in elderly individuals

OBJECTIVE To investigate medications that are related to volume of saliva in the elderly. BACKGROUND DATA In the elderly, many cases of mouth dryness may represent side effects of medication. MATERIALS AND METHODS The volume of unstimulated saliva was measured for 30 s (cotton roll test), and with stimulation for 3 min (gum test) in 368 subjects 79-80 years old (177 men, 191 women). Medications were investigated using subjects medication notebooks. RESULTS Mean volumes of unstimulated and stimulated saliva were 0.14±0.13 and 4.30±2.54 ml respectively. Significant differences were seen between gender and mean volume of saliva. The volume of unstimulated saliva was 0.16±0.15 ml for men and 0.11±0.10 ml for women. The volume of stimulated saliva was 4.99±2.67 ml for men and 3.67±2.25 ml for women. The percentage of subjects taking medication was 64.7% (238/368). Mean number of medications was 2.08±2.26, with no significant difference with gender (2.01±2.37 for men, 2.16±2.16 for women). In a stepwise multiple regression analysis with volume of saliva as the objective variable and number of drugs by category as explanatory variables, significant explanatory variables in addition to gender and number of medications were blood-coagulating agents, Ca antagonists and peptic ulcer drugs for volume of unstimulated saliva, and diabetes medications and peptic ulcer drugs for volume of stimulated saliva. CONCLUSION These findings suggest that differences exist between gender in volume of saliva for elderly individuals, and that the volume of saliva is affected by the number and type of medications.

Hyposalivation and dietary nutrient intake among community‐based older Japanese

Saliva is important for maintaining oral function and regulating oral health. Reduced saliva flow rate, which is common among older adults, has been reported to be associated with perceived chewing and swallowing difficulties; however, its relationship to actual nutrient intake is unclear. The aim of the present cross‐sectional study was to evaluate the relationship between hyposalivation and nutrient intake among older Japanese adults.

Changes in jaw muscle activity and the physical properties of foods with different textures during chewing behaviors

This study aimed to investigate how the activity of the masseter (Mas) and suprahyoid (Hyoid) muscles is influenced by the physical properties of food, how changes in the rheological properties of food differ between different foods during the process of food reduction, and how different salivary flow rates affect bolus-making capability during masticatory behavior in healthy humans. Ten healthy adults participated in this study. Electromyographic (EMG) recordings were obtained from the Mas and Hyoid muscles, and 15 g of steamed rice and rice cake was prepared as test foods. In the ingestion test, the subjects were asked to eat each food in their usual manner. The chewing duration, number of chewing cycles before the first swallow, Mas and Hyoid EMG activity, and chewing cycle time were compared between the foods. Total chewing duration was divided into three substages: early, middle, and late; chewing cycle time and EMG activity per chewing cycle of each substage were compared between the foods and among the substages. In the spitting test, the rheological properties of the bolus at the end of each substage were compared between the foods and among the substages. Finally, stimulated salivary flow rates were measured and the relationships between salivary flow rate and chewing duration, EMG activity, and changes in physical food characteristics were investigated. There were significant differences in total chewing duration and the number of chewing cycles, but not in chewing cycle time, between the foods, which had similar hardness values. The EMG activity levels of the Mas and Hyoid per chewing cycle for the rice cake were significantly greater than for the steamed rice throughout the recording periods. While Mas activity did not change among the substages during chewing, Hyoid EMG activity decreased as chewing progressed. Chewing cycle time also gradually decreased as chewing progressed. The hardness of both foods initially increased, then gradually decreased back to baseline. The adhesiveness of the rice cake initially increased, and did not fall throughout the recording period; the adhesiveness of the steamed rice did not significantly change. Cohesiveness barely changed in either of the two foods during chewing, but was significantly greater for the rice cake than for the steamed rice. Finally, a correlation between the stimulated salivary flow rate and chewing performance was evident only in a change in Mas EMG activity. The current results demonstrate that the activities of the Mas and Hyoid muscles changed as chewing progressed, and were affected by hardness, adhesiveness, and cohesiveness. Salivary flow rate may affect the changes in Mas activity during the process of bolus formation.

Salivary spinability and periodontal disease progression in an elderly population

OBJECTIVE To explore the relationship between the spinability of stimulated whole saliva and periodontal disease progression over 12 months in an elderly population. METHODS Three hundred and thirty-two subjects aged 76 years at baseline were studied. Attachment loss was calculated on a site-by-site basis, and periodontal disease progression was defined as an attachment loss of >or=3mm. Stimulated whole saliva was collected and salivary spinability (SS) was measured. A multiple linear regression analysis was performed to assess the relationship between periodontal disease progression and SS after controlling for other covariates. The independent variables were selected from those which had significant relationships with disease progression in the bivariate analyses. RESULTS Mean SS was 1.94+/-0.42 mm in males and 1.88+/-0.32 mm in females; this difference was not significant. Simple linear regression analysis showed a significant positive relationship between periodontal disease progression and SS (P=0.026), whereas there was no significant relationship between periodontal disease progression and salivary flow rate. Multiple regression analysis revealed a significant positive relationship between periodontal disease progression and SS (P=0.024) after controlling for the number of remaining teeth and baseline periodontal conditions. The model explained 15.5% of the variance in the percentage of sites where the disease had progressed. CONCLUSIONS These findings suggest that elderly subjects with viscous saliva are prone to periodontal disease progression.

Spontaneously active GABAergic interneurons in the subfornical organ of rat slice preparations

Inhibitory postsynaptic currents (IPSCs) were recorded from subfornical organ (SFO) neurons in slice preparations of rats, using whole-cell voltage clamp techniques. Some SFO neurons showed bimodal distributions in amplitude with the large and small IPSCs. The large IPSCs vanished in the tetrodotoxin perfusion medium, but the small did not. Both sizes of the IPSCs were completely abolished by application of bicuculline and picrotoxin. Further subpopulation of SFO neurons with the bimodal distributions showed intermittent bursts of the large IPSCs. Immunohistochemical approach revealed existence of gamma-aminobutyric acid (GABA)-immunoreactive neurons and axons in the SFO. These suggest that spontaneously-active and intermittently-burst-firing GABA interneurons affect other SFO neurons in slice preparations of rats.

Peripheral and central control of swallowing initiation in healthy humans.

We investigated (1) how peripheral inputs might assist central inputs in the control of voluntary evoked swallowing, (2) inter-individual variation in involuntary and voluntary swallowing initiation, and (3) whether natural chewing behavior affects the initiation of involuntary swallowing in healthy humans. Eleven participants completed a repetitive saliva swallowing test (RSST), chewing test (CHEW), and rest period (REST). In RSST, participants repetitively swallowed as quickly as possible. In CHEW, subjects chewed gum freely. We delivered pharyngeal electrical stimulation (PEStim) to the laryngopharynx and compared the number of swallows that occurred with and without PEStim. PEStim significantly increased the number of voluntary evoked swallows in RSST, as well as the number of swallows in CHEW and REST trials, although this facilitatory effect was larger in REST trials. We found a positive correlation between the number of swallows at RSST without PEStim and that at REST with PEStim within individuals. Additionally, we found a significant positive correlation between the number of swallows at RSST with PEStim and the sum of that at RSST without PEStim and at REST with PES. Based on the current results, we suggest that (1) peripheral inputs within a certain range appear to facilitate the central inputs that control voluntary swallowing, (2) inter-individual variations in swallowing initiation may arise from differences in the excitability of the common neural network in the lower brainstem, and (3) during chewing, food reduction in the oral cavity is prioritized, such that the neural network associated with chewing may regulate swallowing initiation.

Changes in the Oral Moisture and the Amount of Microorganisms in Saliva and Tongue Coating after Oral Ingestion Resumption: A Pilot Study

Background and Objective: Tube feeding has been significantly associated with a higher rate of aspiration pneumonia that is mainly related to oral microorganisms and a reduced salivary flow. Thus, the difference in the mode of nutritional intake is expected to affect the oral environment, but this has not yet been fully clarified. The purpose of this study was to investigate, in tube-fed patients, changes in the oral moisture and the counts of microorganisms in saliva and tongue coating, which occur after oral ingestion resumption. Methods: Study participants were 7 tube-fed inpatients of the Niigata University Medical and Dental Hospital (72.7±8.5 years old) who received dysphagia rehabilitation at the Unit of Dysphagia Rehabilitation until oral ingestion resumption. Their oral health, swallowing, and nutrition status, oral mucosal moisture, amount of unstimulated saliva and the counts of microorganisms (total microorganisms, streptococci, Candida) in saliva and tongue coating were investigated and compared before and after the recommencement of oral intake. Results: Tongue coating, choking, oral mucosal moisture and amount of unstimulated saliva were improved significantly after resumption of oral ingestion. The other investigated parameters did not significantly change, except for the streptococci in tongue coating, which significantly increased 1 week after oral ingestion recommencement, but decreased thereafter. Conclusion: After oral intake resumption, oral mucosal moisture and amount of unstimulated saliva were improved. However, because of a transitory increase in the counts of streptococci with oral ingestion recommencement, it is important to appropriately manage oral hygiene in these patients, according to the changes in their intraoral microbiota.

Assessment of inhalation flow patterns of soft mist inhaler co-prescribed with dry powder inhaler using inspiratory flow meter for multi inhalation devices

The patients’ inhalation flow pattern is one of the significant determinants for clinical performance of inhalation therapy. However, the development of inhalation flow meters for various inhalation devices has been unable to keep up with the increasing number of newly launched inhalation devices. In the present study, we developed simple attachment orifices for the inhalation flow pattern monitoring system, which are suitable for all commercial inhalers, and investigated the efficacy of the system on the clinical inhalation instruction for patients co-prescribed dry powder inhaler (DPI) and soft mist inhaler (SMI). First, we constructed simple attachment orifices that were adjusted for 13 commercial inhalers, and examined the correlation between orifice and inhalation device. Second, the inhalation flow patterns (peak inspiratory flow rate, PIFR; inhalation duration time, DT) of patients prescribed a combination of DPI and SMI were monitored before and after inhalation instruction. The inhalation resistance of commercial inhalers are listed in the following order; Twincaps® > Handihaler® > Swinghaler® = Clickhaler® > Twisthaler® > Turbuhaler® > Jenuair® > Diskus® = Ellipta® > Diskhaler® > Breezhaler® > Respimat® = pMDI. The pressure drop via orifice was significantly correlated with that via the commercial inhaler. For the confirmation, all participants achieved the DPI criterion of PIFR. On the other hand, 4 participants (6 clinical visits) of 10 experimented participants could not achieve the essential criterion of DT (> 1.5 sec) for SMI, but all participants improved their duration time after inhalation instruction by pharmacists (P<0.05). In the present study, we successfully developed simple attachment orifice suitable for 13 commercial inhalation devices. These data suggested that our simple attachment orifices for the inhalation flow pattern monitoring system can detect patients with inadequate inhalation patterns via SMI.