A case of superficial spreading type of poorly differentiated adenocarcinoma of the stomach with invasion to the esophagus.

BACKGROUND: Invasion is more likely to occur in gastric cancer affecting larger areas. Poorly differentiated adenocarcinoma tends to invade deep. The cardiac region prefers submucosal invasion because the submucosa is coarser than the other regions. CASE PRESENTATION: A 75-year-old man presented with a chief complaint of abdominal discomfort and weight loss. Esophagogastroduodenoscopy revealed an irregular ulcerative lesion with partial redness of the upper body and lesser curve of the stomach. A continuous shallow depressed lesion invaded the abdominal esophagus by approximately 40 mm. Poorly differentiated adenocarcinomas (por, sig) were observed on biopsy. Grossly, the cancer appeared to extend into the muscle layer; however, we could not confirm invasion into the muscle layer in our biopsy tissue. We diagnosed the lesion as a superficial spreading type of advanced gastric cancer and performed a total gastrectomy, D2-lymph node dissection (spleen preservation), Roux-en-Y reconstruction, and cholecystectomy. Postoperative histopathological examination revealed extensive infiltration of poorly differentiated adenocarcinoma (90 mm × 55 mm), and all were intramucosal lesions. The final pathological diagnosis was T1a, N0, M0, and Stage IA. The postoperative course was uneventful and the patient was discharged on postoperative day (POD) 11. Five years have passed since the operation, and the patient is alive without recurrence. CONCLUSION: We encountered a case of gastric carcinoma in which poorly differentiated adenocarcinomas expanded extensively. All lesions were intramucosal.

Evaluation of the cariogenic potential of a probiotic candidate strain Lactobacillus gasseri YIT 12321.

OBJECTIVE: This study was designed to evaluate the cariogenic potential of Lactobacillus gasseri YIT 12321. DESIGN: L. gasseri YIT 12321 was isolated from the human oral cavity as a probiotic candidate strain. Three types of experimental biofilm formations on bovine enamel specimens were assessed using Streptococcus sobrinus ATCC 33478, L. gasseri YIT 12321, and a co-culture of S. sobrinus and L. gasseri YIT 12321 in vitro. L. gasseri YIT 12321 was analyzed for its ability to utilize seven carbohydrates. L. gasseri YIT 12321 was cultured in tryptic soy broth without dextrose and containing a test carbohydrate at 37 °C for 16 h. RESULTS: The decrease in pH in the region under the biofilm produced by L. gasseri YIT 12321 was unusually slow, and the pH was maintained above 5.5 for 16 h. The amount of biofilm and the reduction in enamel hardness were minimal in the L. gasseri YIT 12321 group among the three experimental groups. The amount of co-culture-derived biofilms was less than that of S. sobrinus biofilms. When S. sobrinus was grown using sucrose, the pH decreased to 3.98. In contrast, L. gasseri YIT 12321 cultures maintained the pH above the critical pH for dentin demineralization. CONCLUSIONS: L. gasseri YIT 12321 is suggested to have a low cariogenic potential. The application of this strain as a probiotic may contribute to oral safety.

Safety assessment of the candidate oral probiotic Lactobacillus crispatus YIT 12319: Analysis of antibiotic resistance and virulence-associated genes.

Lactobacillus crispatus YIT 12319 (LcY) was isolated from the oral cavity of a healthy subject as a new candidate probiotic with potential benefits for oral health. As a safety assessment of LcY, we performed an antibiotic susceptibility test and virulence-associated gene analysis using a draft genome sequence. Susceptibility to 15 antibiotics was analyzed according to the standard method of the International Dairy Federation/International Organization for Standardization, as recommended by the European Food Safety Authority. The results showed that the minimum inhibitory concentrations of LcY were not higher than those of other L. crispatus strains, which have not acquired resistance to any antibiotics, suggesting that LcY had no externally acquired transmissible antibiotic resistance genes. Analysis of virulence-associated genes using the draft genome of LcY found that there were fewer potential virulence-associated genes in LcY than in other probiotics. These findings suggest that LcY could be a candidate probiotic based on its safety profile.

The Effectiveness of the Rectal Administration of Low-dose Diclofenac for the Prevention of Post-endoscopic Retrograde Cholangiopancreatography Pancreatitis.

Objective A 50-100-mg rectal dose of nonsteroidal anti-inflammatory drugs (NSAIDs; diclofenac or indomethacin) has been shown to prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, this is higher than the recommended 25-mg dose that is commonly administered to Japanese patients. The objective of this study was to evaluate the safety and efficacy of 25-mg rectal dose of diclofenac in preventing PEP. Methods Between January 2016 and March 2017, a total of 147 patients underwent ERCP with or without the rectal administration of diclofenac (25 mg) 20 min before the procedure. A retrospective analysis was conducted to evaluate the efficacy and safety of this dose in preventing PEP. Results Thirteen patients (8.8%) developed PEP: 3 patients (4.1%) in the diclofenac group and 10 (13.7%) in the control group (p=0.0460). After ERCP, there were no cases of gastrointestinal hemorrhage, ulceration, acute renal failure, or death. A multivariate logistic regression analysis revealed that the non-administration of rectal diclofenac was a risk factor for PEP (odds ratio=3.530; 95% confidence interval=1.017-16.35; p=0.0468). Conclusions A 25-mg rectal dose of diclofenac might prevent PEP.

Employment, job skills and occupational mobility of cancer survivors.

Previous studies find significant negative effects of cancer on employment, with stronger effects for less-educated workers. We investigate whether the effect of cancer varies by skill requirement in the pre-cancer occupation, whether such heterogeneity can explain educational gradients, and whether cancer is associated with changes in job characteristics for cancer survivors who remain employed four years after the diagnosis. We combine Danish administrative registers with detailed skill requirement data and use individuals without cancer as a control group. Our main findings are the following: the negative effect of cancer on employment is stronger if the pre-cancer occupation requires high levels of manual skills or low levels of cognitive skills; the educational gradient diminishes substantially if we allow the effects of cancer to also depend on pre-cancer skill requirements; and cancer is not associated with occupational mobility, indicating potential for policies that reduce labour market frictions for cancer survivors.

Complete genome sequence of Streptococcus troglodytae TKU31 isolated from the oral cavity of a chimpanzee (Pan troglodytes).

Streptococcus troglodytae TKU31 was isolated from the oral cavity of a chimpanzee (Pan troglodytes) and was found to be the most closely related species of the mutans group streptococci to Streptococcus mutans. The complete sequence of TKU31 genome consists of a single circular chromosome that is 2,097,874 base pairs long and has a G + C content of 37.18%. It possesses 2082 coding sequences (CDSs), 65 tRNAs and five rRNA operons (15 rRNAs). Two clustered regularly interspaced short palindromic repeats, six insertion sequences and two predicted prophage elements were identified. The genome of TKU31 harbors some putative virulence associated genes, including gtfB, gtfC and gtfD genes encoding glucosyltransferase and gbpA, gbpB, gbpC and gbpD genes encoding glucan-binding cell wall-anchored protein. The deduced amino acid identity of the rhamnose-glucose polysaccharide F gene (rgpF), which is one of the serotype determinants, is 91% identical with that of S. mutans LJ23 (serotype k) strain. However, two other virulence-associated genes cnm and cbm, which encode the collagen-binding proteins, were not found in the TKU31 genome. The complete genome sequence of S. troglodytae TKU31 has been deposited at DDBJ/European Nucleotide Archive/GenBank under the accession no. AP014612.

Serum antibody to Porphyromonas gingivalis in metabolic syndrome among an older Japanese population.

BACKGROUND AND OBJECTIVE: Potentially significant associations between metabolic syndrome (MetS) and periodontal disease have been reported in recent studies; however, there is a dearth of literature regarding the relationship of MetS with serum antibody levels to periodontal pathogens. The aim of this cross-sectional study was to investigate the association between MetS and serum antibody to the periodontal pathogen Porphyromonas gingivalis (P. gingivalis) in 216 Japanese individuals aged 79 years. MATERIALS AND METHODS: Serum antibody levels to P. gingivalis were measured by enzyme-linked immunosorbent assay. An elevated serum antibody response was defined as the upper quartile and was considered as the outcome variable. A multivariable logistic regression model was used to evaluate the association of MetS defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria with an elevated antibody status. Adjustments for gender, income, education, smoking status, dental-care utilisation patterns and brushing frequency were considered. RESULTS: The prevalence of MetS was 22.2% (n = 48). Study participants with MetS were 2.9 times more likely to have an elevated serum antibody to P. gingivalis (adjusted odds ratio = 2.91, 95% confidence interval = 1.24-6.85) after simultaneous adjustment for other covariates. CONCLUSION: Our findings suggest an independent relationship between MetS and serum antibody levels to P. gingivalis in the Japanese elderly. Additional longitudinal epidemiologic studies with larger, more diversified samples and more complete information are needed to substantiate our findings.

Streptococcus panodentis sp. nov. from the oral cavities of chimpanzees.

Three strains TKU9, TKU49 and TKU50(T) , were isolated from the oral cavities of chimpanzees (Pan troglodytes). The isolates were all gram-positive, facultative anaerobic cocci that lacked catalase activity. Analysis of partial 16S rRNA gene sequences showed that the most closely related species was Streptococcus infantis (96.7%). The next most closely related species to the isolates were S. rubneri, S. mitis, S. peroris and S. australis (96.6 to 96.4%). Based on the rpoB and gyrB gene sequences, TKU50(T) was clustered with other member of the mitis group. Enzyme activity and sugar fermentation patterns differentiated this novel bacterium from other members of the mitis group streptococci. The DNA G + C content of strain TKU50(T) was 46.7 mol%, which is the highest reported value for members of the mitis group (40-46 mol%). On the basis of the phenotypic characterization, partial 16S rRNA gene and sequences data for two housekeeping gene (gyrB and rpoB), we propose a novel taxa, S. panodentis for TKU 50(T) (type strain = CM 30579(T) = DSM 29921(T) ), for these newly described isolates.

Screening of Probiotic Candidates in Human Oral Bacteria for the Prevention of Dental Disease.

The oral cavity in healthy subjects has a well-balanced microbiota that consists of more than 700 species. However, a disturbance of this balance, with an increase of harmful microbes and a decrease of beneficial microbes, causes oral disorders such as periodontal disease or dental caries. Nowadays, probiotics are expected to confer oral health benefits by modulating the oral microbiota. This study screened new probiotic candidates with potential oral health benefits and no harmful effects on the oral cavity. We screened 14 lactobacillus strains and 36 streptococcus strains out of 896 oral isolates derived from healthy subjects. These bacteria did not produce volatile sulfur compounds or water-insoluble glucan, had higher antibacterial activity against periodontal bacteria, and had higher adherence activity to oral epithelial cells or salivary-coated hydroxyapatite in vitro. We then evaluated the risk of primary cariogenicity and infective endocarditis of the selected oral isolates. As a result, Lactobacillus crispatus YIT 12319, Lactobacillus fermentum YIT 12320, Lactobacillus gasseri YIT 12321, and Streptococcus mitis YIT 12322 were selected because they showed no cariogenic potential in an artificial mouth system and a lower risk of experimental infective endocarditis in a rat model. These candidates are expected as new probiotics with potential oral health benefits and no adverse effects on general health.

Application of chimeric glucanase comprising mutanase and dextranase for prevention of dental biofilm formation.

Water-insoluble glucan (WIG) produced by mutans streptococci, an important cariogenic pathogen, plays an important role in the formation of dental biofilm and adhesion of biofilm to tooth surfaces. Glucanohydrolases, such as mutanase (α-1,3-glucanase) and dextranase (α-1,6-glucanase), are able to hydrolyze WIG. The purposes of this study were to construct bi-functional chimeric glucanase, composed of mutanase and dextranase, and to examine the effects of this chimeric glucanase on the formation and decomposition of biofilm. The mutanase gene from Paenibacillus humicus NA1123 and the dextranase gene from Streptococcus mutans ATCC 25175 were cloned and ligated into a pE-SUMOstar Amp plasmid vector. The resultant his-tagged fusion chimeric glucanase was expressed in Escherichia coli BL21 (DE3) and partially purified. The effects of chimeric glucanase on the formation and decomposition of biofilm formed on a glass surface by Streptococcus sobrinus 6715 glucosyltransferases were then examined. This biofilm was fractionated into firmly adherent, loosely adherent, and non-adherent WIG fractions. Amounts of WIG in each fraction were determined by a phenol-sulfuric acid method, and reducing sugars were quantified by the Somogyi-Nelson method. Chimeric glucanase reduced the formation of the total amount of WIG in a dose-dependent manner, and significant reductions of WIG in the adherent fraction were observed. Moreover, the chimeric glucanase was able to decompose biofilm, being 4.1 times more effective at glucan inhibition of biofilm formation than a mixture of dextranase and mutanase. These results suggest that the chimeric glucanase is useful for prevention of dental biofilm formation.

Effect of silver ion coating of fixed orthodontic retainers on the growth of oral pathogenic bacteria.

Titanium and stainless steel wires used for retainers in orthodontic procedures were coated with Ag ions and the effects of the coating on common oral pathogens and their pathogenicity were investigated. Two species of cariogenic and three species of periodontopathic bacteria were assessed. Biofilms of Streptococcus sobrinus and two VSC gases produced by P. gingivalis were also examined. Ag ion-coated wires showed marked antibacterial activities compared with uncoated wires; in most cases, the differences were statistically significant (p<0.05). All Ag ion-coated wires (Ti+ and SS+ wires) displayed more than 2-mm diameter bacteria growth-resistant zones around them in radial diffusion tests. Ag ion release was 0.043±0.005 ppm in 24 h that didn't show cytotoxicity. Thus, these results suggest that a simple Ag ion coating on pure titanium and stainless steel wires can restrict growth and pathogenic activities of oral pathogenic bacteria, even in the early stages of culture.

Distribution of Streptococcus troglodytae and Streptococcus dentirousetti in chimpanzee oral cavities.

The aim of this study was to analyze the distribution and phenotypic properties of the indigenous streptococci in chimpanzee (Pan troglodytes) oral cavities. Eleven chimpanzees (aged from 9 to 44 years, mean ± SD, 26.9 ± 12.6 years) in the Primate Research Institute of Kyoto University were enrolled in this research and brushing bacterial samples collected from them. Streptococci were isolated from the oral cavities of all chimpanzees. The isolates (n = 46) were identified as thirteen species by 16S rRNA genes analysis. The predominant species was Streptococcus sanguinis of mitis streptococci from five chimpanzees (45%). Mutans streptococci were isolated from six chimpanzees (55%). The predominant species in the mutans streptococci were Streptococcus troglodytae from four chimpanzees (36%), this species having been proposed as a novel species by us, and Streptococcus dentirousetti from three chimpanzees (27%). Streptococcus mutans was isolated from one chimpanzee (9%). However, Streptococcus sobrinus, Streptococcus macacae and Streptococcus downei, which are indigenous to human and monkey (Macaca fasciclaris) oral habitats, were not isolated. Of the mutans streptococci, S. troglodytae, S. dentirousetti, and S. mutans possessed strong adherence activity to glass surface.

A novel method for enhancement of peptide vaccination utilizing T-cell epitopes from conventional vaccines.

Peptide vaccines have two fundamental weak points, namely low antigenicity and MHC-restriction. In our previous study, we proposed the design of vaccine peptide to overcome these weakpoints. The vaccine was constructed in the following order, N-terminal, Arg-Gly-Asp (RGD), T-cell epitope peptide, di-lysine linker (KK) to B-cell epitope peptide. Although the vaccine peptide can basically induce B-cell epitope peptide specific antibodies to the host without immune adjuvants via intraperitoneal, subcutaneous and intranasal administration, some peptide antigens require adjuvants for antibody induction. In this study, we propose a novel protocol to enhance the immunogenicity of the peptide utilizing the host immune response to a conventional toxoid vaccine, which are lymphocyte activities to the T-cell epitope peptide. We selected multiagretope-type T-cell epitopes from diphtheria toxoid, a conventional vaccine antigen, and a part of amyloid-beta peptide (Aß) as a B-cell epitope. The conventional toxoid vaccine was immunized before the peptide immunization. Using this protocol, we succeeded in the enhancement of the anti-Aß antibodies induction by intranasal immunization without any immune adjuvants in C57BL/6 and Balb/c mice. Furthermore, the vaccine peptide induced the transformation of peripheral blood lymphocytes collected from healthy volunteers carrying immunities to diphtheria toxoid. These results suggested that our peptide vaccines with the novel protocol would provide an effective method for antibody induction.

Streptococcus troglodytae sp. nov., from the chimpanzee oral cavity.

Six strains, TKU 25, TKU 28, TKU 30, TKU 31(T), TKU 33 and TKU 34, were isolated from the oral cavity of a chimpanzee (Pan troglodytes). Colonies of strains grown on Mitis-Salivarius agar were similar in morphology to that of Streptococcus mutans. The novel strains were Gram-stain-positive, facultatively anaerobic cocci that lacked catalase activity. Analysis of the partial 16S rRNA gene sequences of these isolates showed that the most closely related strain was the type strain of S. mutans (96.4 %). The next closely related strains to the isolates were the type strains of Streptococcus devriesei (94.5 %) and Streptococcus downei (93.9 %). These isolates could be distinguished from S. mutans by inulin fermentation and alkaline phosphatase activity (API ZYM system). The peptidoglycan type of the novel isolates was Glu-Lys-Ala(3). Strains were not susceptible to bacitracin. On the basis of phenotypic characterization, partial 16S rRNA gene and two housekeeping gene (groEL and sodA) sequence data, we propose a novel taxon, Streptococcus troglodytae sp. nov.; the type strain is TKU 31(T) ( = JCM 18038(T) = DSM 25324(T)).

Inhibitory effects of polysaccharides on the cariogenic activities of Streptococcus mutans.

Many carbohydrates are involved in the biofilm formation and activities of glucosyltransferases (Gtfs) of Streptococcus mutans, and the effects of various disaccharides and polysaccharides were investigated in this study, including the hot water-extracted glucan fraction of the Lentinula edodes fruiting body (HWG). HWG was found to inhibit the initial adhesion of S. mutans to saliva-coated hydroxyapatite (sHA), and also laminarin to inhibit glucan synthesis by Gtfs. However, sucrose-dependent biofilm formation by S. mutans was not inhibited by these materials. Interestingly, dextran was found to have an inhibitory effect on the sucrose-dependent biofilm formation. The data suggest that the presence of such an edible glucan as dextran in daily foods would act to some degree on S. mutans for suppressing the cariogenic activity.

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.

Evaluation of cariogenic bacteria.

OBJECTIVES: The evaluation of Mutans streptococci (MS) is one of the index for caries risk. Dentocult(TM) and CRT(TM) are commercial kits to detect and evaluate MS, conveniently. However, the evaluation of MS has also been carried out simply using an instruction manual. But the instruction manual is not easy to use for evaluation of MS. The aim of this study was to examine the utility of modified Mitis-Salivalius Bacitracin (MSB) agar medium compared with MSB agar medium and commercial kits, and to establish a convenient kit (mMSB-kit) using modified MSB agar. METHODS: The MS in stimulated saliva from 27 subjects were detected by MSB, modified MSB agar medium and commercial kits. Laboratory and clinically isolated strains of MS were similarly evaluated. The ratios of MS in detected bacteria were compared by ELISA. RESULTS: The scores using an mMSB-kit on the basis of modified MSB agar medium were tabulated. Saliva samples showed different levels of MS between culture methods and the commercial kit. Some samples which were full of MS were not detected by the commercial kit. The detection of MS by modified MSB agar medium and mMSB-kit were significantly higher when compared with MSB agar medium,CRT(TM), (P< .01) and Dentocult SM(TM) (P<.05). CONCLUSION: The sensitivity for detection of MS is higher for modified MSB agar medium when compared with MSB agar medium. The mMSB-kit can be used simply, and can be an important contributor for the evaluation of MS as a caries risk factor.

Surface properties of resin composite materials relative to biofilm formation.

The surface properties of three different resin composite materials which influence Streptococcus mutans biofilm formation were evaluated using an artificial mouth system (AMS). Specimens were prepared from Clearfil AP-X, Grandio, and Reactmer Paste, and each material was divided into two groups: (1) surface was ground with 800-grit silicon paper (SiC#800); or (2) surface was polished with up to 1- microm diamond paste (DP1 microm). Biofilms were grown on the surface of each specimen for 20 hours, and then subjected to vortex agitation followed by measurement of retained biofilms. Surfaces with retained biofilms were also inspected by SEM. Significant differences were detected in surface roughness (Ra) between the two polishing conditions for all materials. The quantity of retained biofilm was significantly less (p < 0.05) on Clearfil AP-X DP 1 microm than on Clearfil AP-X SiC#800. With Reactmer Paste, their surfaces registered the lowest amount of retained biofilm--but there were no significant differences between the two polishing conditions. In conclusion, polishing did not render all resin composites equally resistant to biofilm formation.

Influence of a fluoride mouthrinse on mutans streptococci in schoolchildren.

This study aimed to determine whether the long-term use of a fluoride mouthrinse affects the salivary levels of mutans streptococci. Two hundred and fifteen schoolchildren (aged 9-10 years) participated. One hundred and forty-nine of these children had used a fluoride mouthrinse since 5 years of age at nursery school, and the remaining 66 children had not. DFT (decayed and filled teeth) was recorded, and the salivary levels of Streptococcus mutans and Streptococcus sobrinus were measured using mitis salivarius bacitracin agar. The group that had used a fluoride mouthrinse had a significantly lower prevalence of both S. mutans and S. sobrinus (p = 0.038) and a significantly lower DFT score (p < 0.001) than the other group. Using logistic regression analysis including caries experience at baseline as a dependent variable, the odds ratio of carrying S. mutans alone was 8.0 (p = 0.066) and that of carrying both S. mutans and S. sobrinus was 16.5 (p = 0.022) in the group that had not used the fluoride mouthrinse. Children carrying both S. mutans and S. sobrinus had a higher caries incidence in 1 year than the others, with odds ratios of 5.73 (p = 0.067) in the group with a fluoride mouthrinse and 3.47 (p = 0.035) in the group without it. These results show that the long-term use of a fluoride mouthrinse is associated with reduced salivary levels of mutans streptococci and this bacterial reduction may partly contribute to the suppression of dental caries in children using a long-term fluoride mouthrinse.

Production of Fab fragment corresponding to surface protein antigen of Streptococcus mutans serotype c-derived peptide by Escherichia coli and cultured tobacco cells.

The cDNA of a mouse Fab fragment was cloned from a hybridoma cell line that produces a mouse monoclonal antibody, KH5, that reacts with the peptide fragment of the surface protein antigen of Streptococcus mutans serotype c (PAc). After transfection with cDNA, recombinant Fab fragments were produced by Escherichia coli (T15 Fab) and cultured tobacco cells (X253 and X262 Fabs). The antipeptide activities of T15 and X253 were similar to that of KH5. X253 was secreted into the culture media, which had a specific affinity for the PAc peptide.