Screening tests for predicting the prognosis of oral intake in elderly patients with acute pneumonia.

Many elderly patients with pneumonia have aspiration pneumonia. Therefore they must temporarily abstain from oral intake. However, it is difficult to predict whether or not they will be able to start oral intake. The reason is the standard method to evaluate deglutition about pneumonia patients has not been established. In this study we aimed to develop a simple and convenient method that predicts the prognosis of oral intake as nutrition among elderly patients with acute stage pneumonia. Participants were 77 inpatients fasting due to aspiration risk with acute pneumonia. (86.0 ± 7.7 years; range 68-105 years; men: n = 34, women: n = 43) during September 2011 and August 2013. Their consciousness levels were determined by Glasgow coma scale (GCS) and swallowing function and cough reflex were evaluated by repetitive saliva swallowing test (RSST), modified water swallow test, simple swallowing provocation test and cough test. Oral intake status at discharge was considered as the objective variable, and these tests were considered as explanatory variables. Then receiver operating characteristic (ROC) curve and the area under the curve (AUC) for each was done. From the ROC curve analysis, GCS ≥14 had the largest AUC (0.79) with a sensitivity and specificity of 0.71 and 0.80. That was followed by RSST ≥1, AUC (0.77) with a sensitivity and specificity of 0.81 and 0.67. These results suggest that GCS and RSST could be useful screening tests for prognostic prediction of oral intake capability in elderly patients with acute pneumonia.

A missense mutation in the glucosamine-6-phosphate N-acetyltransferase-encoding gene causes temperature-dependent growth defects and ectopic lignin deposition in Arabidopsis.

To study the regulatory mechanisms underlying lignin biosynthesis, we isolated and characterized lignescens (lig), a previously undescribed temperature-sensitive mutant of Arabidopsis thaliana that exhibits ectopic lignin deposition and growth defects under high-temperature conditions. The lig mutation was identified as a single base transition in GNA1 encoding glucosamine-6-phosphate N-acetyltransferase (GNA), a critical enzyme of UDP-N-acetylglucosamine (UDP-GlcNAc) biosynthesis. lig harbors a glycine-to-serine substitution at residue 68 (G68S) of GNA1. Enzyme activity assays of the mutant protein (GNA1(G68S)) showed its thermolability relative to the wild-type protein. The lig mutant exposed to the restrictive temperature contained a significantly smaller amount of UDP-GlcNAc than did the wild type. The growth defects and ectopic lignification of lig were suppressed by the addition of UDP-GlcNAc. Since UDP-GlcNAc is an initial sugar donor of N-glycan synthesis and impaired N-glycan synthesis is known to induce the unfolded protein response (UPR), we examined possible relationships between N-glycan synthesis, UPR, and the lig phenotype. N-glycans were reduced and LUMINAL BINDING PROTEIN3, a typical UPR gene, was expressed in lig at the restrictive temperature. Furthermore, treatment with UPR-inducing reagents phenocopied the lig mutant. Our data collectively suggest that impairment of N-glycan synthesis due to a shortage of UDP-GlcNAc leads to ectopic lignin accumulation, mostly through the UPR.

Usefulness of a handheld nebulizer in cough test to screen for silent aspiration.

Cough test to screen for silent aspiration (SA) was reported, and the effectiveness was excellent. However, the device was rather large so that the portability was poor. So, the purpose of this study is to investigate the usefulness of a handheld nebulizer for the test and verify the reproducibility of the method. The subjects were 160 patients who were suspected of having dysphagia and underwent videofluorography (VF) or videoendoscopy (VE). They inhaled 1.0 % citric acid-physiologic saline orally for 1 min using a handheld nebulizer, and the examiner observed the number of coughs: more than five coughs was considered as negative (normal), while less than four coughs was regarded as positive. Among the subjects, 70 patients administered the cough test and VF or VE twice or more at some intervals. The k coefficient was calculated in reproducibility. Using the results of the VF or VE examination as the standards, for SA detection, the sensitivity was 0.86, specificity was 0.71, positive predictive value was 0.53, and negative predictive value was 0.93. The k coefficient was 0.79. In conclusion, the handheld nebulizer was useful in the cough test to screen for SA. Furthermore, satisfactory reproducibility was shown.

A case of laparoscopic sigmoidectomy using thermography for colonic blood flow assessment.

BACKGROUND: Indocyanine green (ICG) fluorescence imaging is widely used in gastrointestinal surgery and is considered useful for reducing anastomotic leakage; however, because ICG remains in the tissue for a certain amount of time, we occasionally must re-evaluate colonic blood flow over a short time period during surgery. Herein, we verify the usefulness of thermography (TG) for evaluating colonic blood flow in a patient who underwent a laparoscopic sigmoidectomy for sigmoid colon cancer. CASE PRESENTATION: The patient is 43-year-old man who underwent laparoscopic resection of the sigmoid colon for colon cancer. After vascular treatment of the colonic mesentery, ICG/TG identified the boundary between ischemic and non-ischemic colon tissues. An additional 2 cm of colonic mesentery was resected because of the presence of a diverticulum noted at the intended site of oral anastomosis when attaching the anvil head. After additional vascular treatment of the colonic mesentery and administration of ICG, fluorescence was observed in the colon; however, TG identified the zone of the temperature transition on the surface of the colonic mesentery, even after additional colonic mesentery resection in the same region as previously observed. This zone was used as the cut-off line. There were no complications, such as anastomotic leakage, after the surgery. CONCLUSION: Although accumulation of similar cases is necessary, TG has the potential for use as an auxiliary diagnostic tool in clinical practice. TG can depict the presence or absence of blood flow based on surface temperature without the use of imaging agents, and is inexpensive and easy to perform.

Research of masticatory function using hemiplegia simulator equipment.

BACKGROUND AND OBJECTIVE: Hemiplegic patients often exhibit a characteristic condition called Wernicke-Mann contracture. Therefore, the occlusal pattern in hemiplegic patients is considered to be adapted to stress because of this characteristic limb position. We created a sham Wernicke-Mann contracture in healthy individuals using hemiplegia simulator equipment and compared the functional occlusion in this position with that in the normal state to evaluate dynamic adaptive responses. METHODS: Wernicke-Mann contracture was simulated using a device to create sham hemiplegia (Manabi-tai, Hemiplegia Experiencing Set; Tokushu-iryo, Inc.). In addition to the measurement of the occlusal force using Dental Prescale(®) and Occluzer(®), the occlusion was evaluated using an electromyogram and stabilometer. RESULTS: There was a significant difference in the occlusal force between the normal state and during simulated hemiplegia. The surface electromyo-potential of the masseter muscle showed significantly higher values during simulated hemiplegia. It is significantly higher during simulated hemiplegia than in the normal state on the paralysed side, but not for the normal state on the non-paralysed side. The position and velocity vectors changed in the antero-posterior direction in the normal state but in the lateral direction during simulated hemiplegia. CONCLUSIONS: The hemiplegia simulator equipment is useful for research on hemiplegia, and that the occlusal balance is disturbed in the posture characteristic of hemiplegia.

Essential role of caspase-8 in p53/p73-dependent apoptosis induced by etoposide in head and neck carcinoma cells.

BACKGROUND: Caspase-8 is a key upstream mediator in death receptor-mediated apoptosis and also participates in mitochondria-mediated apoptosis via cleavage of proapoptotic Bid. However, the role of caspase-8 in p53- and p73-dependent apoptosis induced by genotoxic drugs remains unclear. We recently reported that the reconstitution of procaspase-8 is sufficient for sensitizing cisplatin- but not etoposide-induced apoptosis, in chemoresistant and caspase-8 deficient HOC313 head and neck squamous cell carcinoma (HNSCC) cells. RESULTS: We show that p53/p73-dependent caspase-8 activation is required for sensitizing etoposide-induced apoptosis by utilizing HOC313 cells carrying a temperature-sensitive p53G285K mutant. Restoration of wild-type p53 function under the permissive conditions, together with etoposide treatment, led to substantial transcriptional activation of proapoptotic Noxa and PUMA, but failed to induce apoptosis. In addition to p53 restoration, caspase-8 reconstitution was needed for sensitization to etoposide-induced apoptosis, mitochondria depolarization, and cleavage of the procaspases-3, and -9. In etoposide-sensitive Ca9-22 cells carrying a temperature-insensitive mutant p53, siRNA-based p73 knockdown blocked etoposide-induced apoptosis and procaspase-8 cleavage. However, induction of p73 protein and up-regulation of Noxa and PUMA, although observed in Ca9-22 cells, were hardly detected in etoposide-treated HOC313 cells under non-permissive conditions, suggesting a contribution of p73 reduction to etoposide resistance in HOC313 cells. Finally, the caspase-9 inhibitor Ac-LEHD-CHO or caspase-9 siRNA blocked etoposide-induced caspase-8 activation, Bid cleavage, and apoptosis in both cell lines, indicating that p53/p73-dependent caspase-8 activation lies downstream of mitochondria. CONCLUSIONS: we conclude that p53 and p73 can act as upstream regulators of caspase-8, and that caspase-8 is an essential mediator of the p53/p73-dependent apoptosis induced by etoposide in HNSCC cells. Our data suggest the importance of caspase-8-mediated positive feedback amplification in the p53/p73-dependent apoptosis induced by etoposide in HNSCC cells.

Inhibition of Streptococcus mutans biofilm formation by Streptococcus salivarius FruA.

The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity.

[The effect of oral care on natural immune function in the dependent elderly].

While oral care is known to play an important role in the prevention of aspiration pneumonia, its influence on immune function is unclear. In this study, we performed oral care on ten dependent elderly individuals and examined its influence on NK cell activity. The study duration was 12 weeks. During the first six weeks, the subjects cleaned their mouths as usual (control period). In the last six weeks, a dental hygienist performed oral care and denture cleaning three times a week (intervention period). The outcome measure was the quantity of oral bacteria and the detection rate of the microbe in connection with an opportunistic infection and NK cell activity before and after the intervention. Samples were collected at three time points: the beginning of the study, after the control period and before the intervention period (i. e., after six weeks), and after the intervention period (i. e., after 12 weeks). There was no significant difference in the number of oral bacteria between the control period and the intervention period. In contrast, while NK cell activity did not change during the control period, activity increased during the intervention period (p = 0.03). This finding suggests that rather than decreasing the number of oral bacteria, oral care increases NK cell activity.

The effects of polyunsaturated fatty acids and their metabolites on osteoclastogenesis in vitro.

Bone homeostasis is maintained by active remodeling through the balance between resorption (by osteoclasts) and synthesis (by osteoblasts). In this study, we examined the effects of polyunsaturated fatty acids (PUFAs) and their metabolites on sRANKL-induced differentiation of bone marrow-derived macrophages (BMMs) into osteoclasts in vitro. Docosahexaenoic acid (DHA) strongly inhibited osteoclastogenesis; however, dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA) and eicosapentaenoic acid (EPA) enhanced it. The enhancement effect of PUFAs on osteoclastogenesis was mediated predominantly by cyclooxygenase (COX) products, because the effect was inhibited by a COX inhibitor. It was also found that COX products of PUFAs, prostaglandin E(1), E(2), and E(3), clearly increased in osteoclastogenesis. The inhibitory effect of DHA on osteoclastogenesis was reversed by treatment with a lipoxygenase (LOX) inhibitor. Furthermore, resolvin D1, a LOX product of DHA, significantly inhibited osteoclastogenesis. Quantitative analysis of specific mRNA levels revealed that DHA-mediated attenuation of osteoclastogenesis might be due to a decrease in DC-STAMP expression. These results suggested that the effect of DHA on osteoclastogenesis is, at least in part, mediated by lipoxygenase products. This study showed a distinct mechanism of the effect of PUFAs on osteoclastogenesis and will provide evidence for therapeutic treatment with DHA in osteoporotic patients.

Association of caspase-8 mutation with chemoresistance to cisplatin in HOC313 head and neck squamous cell carcinoma cells.

Caspase-8 is a critical upstream mediator of apoptosis in the death receptor pathway. However, the relationship between caspase-8 mutation and chemosensitivity remain unclear in head and neck squamous cell carcinoma (HNSCC) carrying p53 mutation. In this study, we identified a caspase-8 nonsense mutation, accompanied by the loss of the second allele, in a drug-resistant HOC313 HNSCC cell line. The nonsense mutation (R68X) leads to truncation of all defined functional domains. Reconstitution of caspase-8 by stable transfection of wild-type caspase-8 sensitized the cells to cisplatin-, but not etoposide-induced apoptosis. Consistent with this, cisplatin, but not etoposide, induced TNF-alpha and TRAIL mRNA in caspase-8 reconstituted HOC313 cells, accompanied by activation of the reconstituted caspase-8 and its downstream caspase-3. These results indicate that the loss of caspase-8 plays an important role in acquisition of chemoresistance to cisplatin in HOC313 cells.

The effect of lateral shift of cricoid cartilage on pharyngeal swallowing.

Head rotation is widely used as one of the postural techniques for dysphagic patients. However, it cannot be used for patients with severe limitations to the range of motion of the neck. The purpose of this study was to determine the effect of applying pressure to the cricoid while swallowing and to explore the possibility of this maneuver as an alternative to head rotation. The swallowing function of 12 volunteers was examined with videofluorography under nine conditions: neutral, head rotated to the right, head rotated to the left, applying pressure to the cricoid on the right side at 5, 10, and 15 N, and applying pressure to the cricoid on the left side at 5, 10, and 15 N. To examine the effect of this maneuver on pharyngeal swallowing, the laterality of bolus flow was evaluated using 3 ml barium thin liquid from the posterior-anterior (P-A) view. The "pressing-cricoid" maneuver significantly altered the laterality of the bolus flow; the bolus flow was shifted to the side opposite to which the pressure was applied. The results of these changes were similar to those achieved with head rotation. These results demonstrated that the "pressing-cricoid" maneuver changes the bolus flow. This maneuver may have therapeutic value for the treatment of dysphagic patients as an alternative to head rotation.

Hyoid movement and laryngeal penetration during sequential swallowing.

This study examined hyoid movement during sequential swallowing and evaluated the relationship among trajectory patterns, swallowing types based on laryngeal movement and laryngeal penetration. Twelve healthy adults underwent videofluorography during sequential swallowing. Each swallow was classified into two types: opened laryngeal vestibule after swallow (i-Segmental type) and closed laryngeal vestibule after swallow (i-Continuous type). Each participant's swallowing type was classified by the same method. We analyzed two-dimensional movements of the hyoid, and the trajectories were classified into three patterns: hyoid moved in the anterosuperior direction after the onset of swallow (pattern L); hyoid moved in the anterosuperior direction after the onset of swallow, beyond the mandibular plane (pattern X); and the hyoid was above the mandibular plane at the onset of swallow, and then it moved in the inferior direction (pattern U). Two-way ANOVA revealed that there was a significant interaction between the swallowing type and trajectory pattern, and laryngeal penetration was the highest for the combination of individual swallow of i-Continuous type and pattern L. In sequential swallowing, the existence of a penetration-prone swallowing pattern combination was an interesting phenomenon relevant to eating management for dysphagic patients; however further study in patient groups is required.

The role of anti-PAc (361-386) peptide SIgA antibody in professional oral hygiene of the elderly.

OBJECTIVE: Measurement of salivary IgA antibody (PAc-peptide antibody, PPA) to amino acid residues 361-386 of Streptococcus mutans PAc, which possess a multiple binding motif to various HLA-DR molecules and a B-cell epitope that recognises the inhibiting antibody to S. mutans, is an indicator for the population numbers of mutans streptococci (MS) in human saliva. The purpose of this study was to clarify the role of PPA in infection control of MS after professional oral hygiene care. MATERIALS AND METHODS: Thirty-nine dependently living institutionalised elderly subjects (75.9 +/- 7.5 years; 10 males, 29 females) participated in the study. The measurements of PPA, MS, total streptococci (TS) and lactobacilli (LB) were performed by ELISA and culture techniques from saliva, plaque and tongue samples from the elderly. RESULTS: After treatment using professional oral care, the numbers of MS decreased significantly at 6 months in saliva and tongue samples from the group not having PPA in comparison with the primary data; whereas in the PPA-detected group, a significant decrease in MS number was shown immediately following professional care at 1-12 months in all samples. There was little difference in the numbers of LB at any of the time points. The numbers of TS decreased rapidly in PPA-not detected group in comparison with the PPA-detected group. CONCLUSION: PPA may be more effective for controlling MS number in the oral cavity after professional treatment. The measurement of PPA may be used for preventive instruction to dental caries at the chair side in the clinical setting.

Role of activated natural killer cells in oral diseases.

Many of the protective immune responses of old people are impaired and this leads to an increased risk of oral bacterial infections. Little is known about the interaction between the systemic immune response on one hand and oral infections and oral diseases on the other. Here, we conducted an epidemiological study of the independent elderly to determine the relationships between activated natural killer (NK) cells and oral bacterial infections: oral diseases such as dental caries and periodontal disease. One hundred independent elderly people aged 77 years old (53 males, 47 females) were examined. Blood samples were drawn, and activated NK cells were evaluated using CD16, CD56, and CD69 monoclonal antibodies with flow cytometry. Bacterial counts for oral streptococci, lactobacillus, and opportunistic pathogens were performed using culture techniques. Oral disease examinations were performed by dentists. A larger percentage of CD69(+)NK cells (CD16(+)CD56(+)) showed significant correlations to the isolation numbers of total streptococci (r=0.409, P<0.01), the species numbers of opportunistic pathogens (r=-0.318, P<0.01), the numbers of decayed teeth (r=-0.223, P<0.05), and the amount of bridge work (r=0.219, P<0.05). A higher proportion of CD69(+)NK cells is associated with the incidence of dental caries and the number of opportunistic pathogens and total streptococci in the oral cavity of the elderly. This suggests that the proportionate number of CD69(+)NK cells may be a useful indicator for oral infection in elderly subjects.

Age-related changes in oral mechanosensitivity of symptom-free subjects.

The purpose of this study was to determine the effect of aging on the tactile and pain sensitivity, and the factors influencing threshold change in the oral mucosa using Semmes-Weinstein Pressure Aesthesiometer. The touch and pain thresholds of 81 healthy elderly (40 males and 41 females, 77 +/- 4.5 years) were compared with those of 58 young volunteers (27 males and 31 females, 27 +/- 2.5 years). We measured the pain thresholds, the touch thresholds, PCR score and amount of salivation. Semmes-Weinstein Pressure Aesthesiometer was applied to 9 points in the oral region and 4 points in the hands; the dorsum manus, the palma manus, the incisive papilla, the palatal mucosa, the buccal mucosa, the margin of the tongue, and the dorsum of the tongue. Elderly subjects showed significantly higher touch thresholds than those of young subjects in the dorsum manus, the palma manus, the buccal mucosa, the incisive papilla, the margin of the tongue, and the dorsum of the tongue (P < 0.05). The pain thresholds of elderly subjects were significantly lower than those of young subjects in the buccal mucosa and the palatal mucosa (P < 0.05). The touch threshold was not influenced by the smoking habit, denture and amount of salivation. The pain threshold was influenced by the denture on the palate.

Impact of routine oral care on opportunistic pathogens in the institutionalized elderly.

Routine oral hygiene is important for the control of opportunistic pathogens in the oral cavity of institutionalized elderly individuals. We evaluated the effects of routine oral care on opportunistic pathogens at various time points after admission to a nursing home. Twenty-five elderly subjects living in the nursing home (mean age: 86.0 +/- 10.4 years) participated in the study. Caregivers and dental hygienists cleaned the teeth, dentures, tongue, and mucosa after each meal using both routine and professional oral care techniques. Opportunistic pathogens were collected from the teeth, tongue, and mucosal surfaces using a cotton swab; and the species of microbes were determined and the numbers were counted following cultivation on selective agar. Regular oral care including professional oral care was found to be effective for reducing infections by many kinds of opportunistic pathogens on the teeth surfaces and the oral environment without food residue during a long-term study (6 months). Further, this care after 1 month significantly reduced infections by opportunistic pathogens on mucosal surfaces in subjects without dentures; however, this was not observed in those with dentures. Our data shows the importance of regular oral care in cleaning hard and soft surfaces of the oral cavity improves the oral health of the institutionalized elderly.

Pulmonary exposure to diesel exhaust particles enhances fatty change of the liver in obese diabetic mice.

In epidemiological studies, exposure to ambient particulate matter (PM) has been reported to be positively associated with mortality in subjects with diabetes mellitus. Diesel exhaust particles (DEP) are major constituents of atmospheric PM. However, there is no experimental evidence for the relation of DEP to diabetes mellitus and its complications. We investigated the effects of DEP inoculated intratracheally on diabetic changes and nonalcoholic fatty liver disease (NAFLD) in diabetic obese and control mice. db/db mice and the corresponding nondiabetic db/+m mice received exposure to vehicle or DEP every two weeks. Animals were examined with biochemistry, histology, and immunohistochemistry for hexanoyl-lysine (HEL) in the liver. In the db/+m mice, pulmonary exposure to DEP did not increase levels of aspartate aminotransferase (AST) or alanine aminotransferase (ALT) compared to that to vehicle. In the db/db mice, however, the exposure to DEP increased the levels of AST and ALT compared to that to vehicle. Only in the db/db mice, DEP enhanced the magnitude of steatosis and formation of HEL, a marker of oxidative stress, in the liver compared to vehicle. These results suggest that pulmonary exposure to DEP, PM, enhances steatosis in the liver of obese diabetic subjects possibly via enhanced oxidative stress.

Dietary supplementation with cacao liquor proanthocyanidins prevents elevation of blood glucose levels in diabetic obese mice.

OBJECTIVE: Effective approaches should be established to prevent the onset of type 2 diabetes mellitus, which has been increasing in developed countries. The present study examined whether dietary supplementation with cacao liquor proanthocyanidins (CLPr) could prevent elevation of blood glucose levels in mice with diabetes mellitus and obesity. METHODS: C57BL/KsJ-db/db (db/db) diabetic obese mice and C57BL/KsJ-db/+m (db/+m) control mice were fed a diet containing 0% w/w CLPr (0% CLPr), 0.5% w/w CLPr (0.5% CLPr), or 1.0% w/w CLPr (1.0% CLPr) from age 3 wk to age 6 wk. Levels of blood glucose were measured at 4 and 5 wk of age. The animals were sacrificed and the levels of blood glucose and fructosamine were measured at 6 wk of age. RESULTS: The levels of blood glucose and fructosamine were higher in the db/db mice than in the db/+m mice fed a diet containing 0%, 0.5%, or 1.0% CLPr. In the db/+m mice, the levels of blood glucose or fructosamine were not significantly different across animals fed 0% CLPr, 0.5% CLPr, and 1.0% CLPr. In the db/db mice, however, a diet containing 0.5% or 1.0% CLPr decreased the levels of blood glucose and fructosamine compared with that containing 0% CLPr without significant effects on body weights or food consumption. CONCLUSION: Dietary supplementation with CLPr can dose-dependently prevent the development of hyperglycemia in diabetic obese mice. The dietary intake of food or drinks produced from cacao beans might be beneficial in preventing the onset of type 2 diabetes mellitus.

Effects of oral care on development of oral mucositis and microorganisms in patients with esophageal cancer.

We evaluated the effects of special oral care using a toothbrush with combined irrigation and suctioning functions, along with povidone-iodine to treat oral bacteria and mucositis, in esophageal cancer patients undergoing chemoradiotherapy. In the special care group, oral hygiene was performed 3 days a week after dinner. Bacteria in saliva and plague samples were measured at various sampling points after chemoradiotherapy. The incidence of mucositis was significantly reduced in the special care group in comparison with the control group. Total streptococci were significantly decreased in the opportunistic pathogens-positive and lower-level mutans streptococci control group during chemoradiotherapy, but they were not reduced in the opportunistic pathogens-negative and higher-level mutans streptococci control groups or in the special care group. Our results showed that a special oral care regimen enabled the total population of streptococci microflora to remain stable, was negatively correlated with opportunistic pathogens and positively correlated with mutans streptococci infection, and prevented the development of mucositis.

Cortical activation during solid bolus swallowing.

Specific areas of cortical activity during solid bolus swallowing in humans are unknown. We tested the hypothesis that cortical representations of swallowing in humans may vary by bolus type. Twenty-one normal subjects swallowed three kinds of food: agar (solid), a capsule and water. We followed the same countdown method for identification of the cortical representations during swallowing performances as a previous study (Tanaka et al., 2006). Functional magnetic resonance imaging (fMRI) showed that the precentral gyrus, postcentral gyrus, medial temporal gyrus, superior temporal gyrus and cingulate gyrus were activated when swallowing an agar bolus (p<0.001). The subcortex was not activated. The cerebellum was activated only during capsule swallowing (P<0.001). Water bolus swallowing activations were similar to agar bolus swallowing. The cluster size of water swallowing was larger than the agar swallowing. We conclude that the cortical representations for swallowing are variable by food type.