Search

Mutations in RAS or BRAF are associated with poor prognosis and resistance to epidermal growth factor receptor (EGFR)-targeted therapy in colorectal cancer (CRC). Despite their common ability to activate downstream genes such as MEK and ERK, the therapeutic benefit of MEK inhibitors for patients with RAS/BRAF mutant CRC is limited, highlighting the need for biomarkers to predict the efficacy of MEK inhibition. Previously, we reported that a change in phosphorylation of ribosomal protein S6 (pS6) after MEK inhibition was significantly associated with sensitivity to MEK inhibition in gastric cancer cells. Here, we investigated the value of the response in pS6 for predicting the efficacy of trametinib, a MEK inhibitor, in patients with RAS/BRAF mutant CRC using patient-derived CRC organoids. We found that a subset of CRC cell lines and organoids were sensitive to trametinib. The change in phosphorylated ERK, a downstream molecule of the RAS/RAF/MEK pathway, was not significantly associated with trametinib sensitivity. On the other hand, only those with sensitivity showed a reduction of pS6 levels in response to trametinib. The change in pS6 after trametinib treatment was detectable by Western blotting, immunohistochemistry or immunocytochemistry. We also demonstrated an impact of MEK inhibition on pS6 in vivo using a xenograft model. Our data suggest that, in combination with patient-derived organoids, immunostaining-based detection of pS6 could be useful for prediction of trametinib sensitivity.

Byline: Masataka. Uehara, Ryouichi. Ohya, Masaaki. Kodama, Takeshi. Shiraishi, Izumi. Asahina, Kazuhiro. Tominaga The nonsurgical strategies for locally advanced oral cancer are desirable. Superselective intra-arterial infusion with radiotherapy was utilized [...]

Background:Both environmental and genetic factors have been implicated in the induction of autoimmune disease. Therefore, it is important to understand the pathophysiological significance of the gut microbiota and host genetic background that contribute to an autoimmune disease such as inflammatory bowel disease (IBD). We have previously reported that mice deficient for suppressor of cytokine signaling-1 (SOCS1), in which SOCS1 expression was restored in T and B cells on an SOCS1–/–background (SOCS1–/–Tg mice), developed systemic autoimmune diseases accompanied by spontaneous colitis. Methods:To investigate whether the proinflammatory genetic background affects the gut microbiota, we used SOCS1–/–Tg mice as a model of spontaneous chronic colitis. Fecal samples were collected from SOCS1–/–Tg mice and SOCS1+/+Tg (control) mice at 1 and 6 months of age, and the fecal bacterial 16S ribosomal RNA genes were sequenced using the Illumina MiSeq platform. Results:Gut microbial diversity was significantly reduced and the intestinal bacterial community composition changed in SOCS1–/–Tg mice in comparison with the control mice. Interestingly, the population of Prevotellaspecies, which is known to be elevated in ulcerative colitis and colorectal cancer patients, was significantly increased in SOCS1–/–Tg mice regardless of age. Conclusion:Taken together, these results suggest that the proinflammatory genetic background owing to SOCS1 deficiency causes dysbiosis of the gut microbiota, which in turn generates a procolitogenic environment.

Patient-derived tumor organoids have considerable potential as an in vitro diagnostic tool for drug susceptibility testing. In the present study, we investigated whether bile collected for diagnostic purposes could be a potential source for the establishment of biliary cancer organoids. Among 68 cases of biliary cancer, we successfully generated 60 bile-derived organoids (BDOs) from individual patients. Consistent with previous reports that described biliary cancer organoids from surgical tissues, the BDOs showed diverse morphologies such as simple cysts, multiloculated cysts, thick capsulated cysts, and solid masses. They also harbored mutations in KRAS and TP53 at frequencies of 15% and 55%, respectively. To enrich the cancer organoids by removing contaminated noncancerous components of BDOs, we attempted to verify the effectiveness of 3 different procedures, including repeat passage, xenografting, and selection with an MDM2 inhibitor for TP53 mutation–harboring BDOs. By monitoring the sequence and expression of mutated TP53, we found that all these procedures successfully enriched the cancer organoids. Our data suggest that BDOs can be established with minimal invasiveness from almost all patients with biliary cancers, including inoperable cases. Thus, despite some limitations with respect to the characterization of BDOs and methods for the enrichment of cancer cell–derived organoids, our data suggest that BDOs have potential applications in personalized medicine.

Various modalities are available for the diagnosis of diseases affecting the oral and maxillofacial regions and the accuracy of diagnosis for many kinds of diseases in oral and maxillofacial regions is readily increasing. In particular, considerable research has focused on the use of magnetic resonance (MR) images for functional evaluation, as well as morphological examination, due to the high spatial resolution of the images, the fast acquisition time, and the image processing techniques associated with the growing computational power and improvements in the MR system. Therefore, we developed and named “Dynamic MR sialography”, a new technique for the functional evaluation of salivary glands using continuous MR sialography pre- and post-citric acid stimulation on the tongue. In the present review, we focused the “Dynamic MR sialography”, and introduce the methods, applications and significances of its technique in the diagnostic process of salivary glands-related diseases. In addition, we review the significance of the prognostic evaluation for the improvement of saliva flow rate after saline solution irrigation treatment.

To determine whether the presence of dupA Helicobacter pylori(H. pylori) influences the cure rate of primary eradication therapy.

ABSTRACTThe determination of the cagAgenotype is generally based on sequencing the variable 3' region of the cagAgene. In a previous study, we successfully generated an anti-East Asian CagA-specific antibody (anti-EAS Ab) immunoreactive only with the East Asian CagA and not with the Western CagA. In a small number of Japanese patients, anti-EAS Ab appeared to be a useful tool for phenotyping CagA immunohistochemically. The present study was conducted to validate the anti-EAS Ab immunohistochemistry method in a larger number of patients from Vietnam and Thailand. A total of 385 Vietnamese and Thais were recruited. Helicobacter pyloristatus was determined by a combination of three methods, including culture, histology, and immunohistochemistry with anti-H. pyloriantibody. The sensitivity, specificity, and accuracy of the anti-EAS Ab immunohistochemistry method for the diagnosis of CagA phenotype were calculated based on the results of the cagAsequencing as the gold standard. The sensitivity, specificity, and accuracy of our immunohistochemistry method were 96.7%, 97.9%, and 97.1%, respectively. Moreover, anti-EAS Ab was not cross-reactive with noninfected gastric mucosa. In conclusion, immunohistochemistry with anti-EAS Ab appears to be a good method for determination of CagA phenotype.

Various modalities are available for the diagnosis of diseases affecting the oral and maxillofacial regions. The currently used imaging modalities include intra-oral radiographs, panoramic radiographs, magnetic resonance imaging (MRI), computed tomography (CT) including cone-beam (CB) CT, ultrasonography (US), and nuclear medicine including positron emission tomography (PET). In the present review, we describe the application and significance of each modality in the diagnostic process of oral and maxillofacial diseases.

Mucoepidermoid carcinoma comprises approximately 35% of all malignancies of major and minor salivary glands. Histopathologically, these are classified as low, intermediate, or high-grade tumours, where prognosis depends on the grading. This report is of a patient with mucoepidermoid carcinoma of the mandibular gingiva that produced granulocyte colony-stimulating factor, in whom granulocyte colony-stimulating factor production by the tumour lead to rapid local recurrence as well as distant metastasis.

We compared the eradication results of retreatment of eradication with proton pump inhibitor (PPI) plus amoxicillin and metronidazole for patients with Helicobacter pyloriinfection not eradicated by initial treatment with PPI plus amoxicillin and clarithromycin.

Persistent Helicobacter pyloriinfection contributes towards the development of chronic gastritis. To clarify the changes in chronic gastritis as a precursor of gastric cancer secondary to H. pylorieradication is an important issue, as it has significant implications for reducing the risk of gastric cancer. Studies published to date, however, are far from consistent with regard to the morphologic changes reported following H. pylorieradication. Of these, some papers reported improvement in gastric atrophy or intestinal metaplasia, versus others reporting no improvement, with the majority of papers published after 2000 reporting improvement in these end points. The inconsistent results concerning the impact of H. pylorieradication on gastric atrophy could be due to the inconsistency of the diagnostic criteria employed for evaluation of the morphology, confounded by the difficulties involved in evaluating atrophic changes in the gastric mucosa. While adherence to the Updated Sydney System available for evaluation of gastritis is primarily required worldwide to ensure consistency in evaluating gastritis, long-term research into the morphologic changes associated with H. pylorieradication is also required to explore strategies for the prevention of gastric cancer with H. pylorieradication.

Helicobacter pylori is considered to have a close association with gastric cancer. Many epidemiological studies have shown a strong association between chronic H. pylori infection and subsequent development of gastric carcinoma in humans. To clarify this link more clearly, it is necessary to use this bacterium in experimental studies to develop gastric carcinoma in suitable experimental animals. Persistent H. pylori infection was seen in the Japanese monkey model, and has recently been achieved in the Mongolian gerbil model. In these models, the sequential histopathological changes in the gastric mucosa are very similar to those in humans. The Japanese monkey model showed advances in atrophic change and p53 point mutations in the gastric mucosa during long-term observation. The Mongolian gerbil model demonstrated that H. pylori infection enhances gastric carcinogenesis in combination with known carcinogens such as N-methyl-N-nitrosourea (MNU) and N-methyl-N-nitro-N′-nitrosoguanidine (MNNG), and also showed that H. pylori infection alone can result in the development of gastric carcinoma. These important results provide a starting point for further studies to clarify the mechanism of gastric carcinogenesis as a result of H. pylori infection and assist in the planning of eradication therapy to prevent gastric carcinoma.

ABSTRACTIt has been documented that sucralfate, a basic aluminum salt, enhances the efficacies of antibiotics against Helicobacter pylori, resulting in eradication rates comparable to those associated with the use of proton pump inhibitors. However, its mechanism of action remains unclear. The aim of the present study was to investigate sucralfate's ability to complement antibiotic treatment of H. pyloriinfection in vivo. Four weeks following induced H. pyloriinfection, clarithromycin (CAM) and amoxicillin (AMPC) were administered orally to C57BL/6 mice for 5 days, both with and without sucralfate or lansoprazole. When sucralfate was concurrently given with CAM and AMPC at the maximum noninhibitory doses for the treatment of H. pyloriinfection, the bacterial clearance rates were comparable to those achieved by treatment with lansoprazole plus those antibiotics. The results of pharmacokinetic studies showed that lansoprazole delayed gastric clearance and accelerated the absorption of CAM, whereas sucralfate suppressed both gastric clearance and absorption. AMPC was undetectable in all samples. Scanning electron microscopy with a microscope to which a energy dispersive spectrometer was attached revealed that aluminum-containing aggregated substances coated the mucosa surrounding H. pyloriin mice receiving sucralfate plus antibiotics, whereas the gastric surface and pits where H. pylorihad attached were clearly visible in mice receiving lansoprazole plus antibiotics. The addition of sucralfate to the antibiotic suspension resulted in a more viscous mixture that bound to the H. pylori-infected mucosa and that inhibited the loss of CAM bioavailability in the acidic environment. Sucralfate delays gastric clearance of CAM and physically captures H. pylorithrough the creation of an adherent mucus, which leads to bacterial clearance.

Recent evidence has implicated bacterial involvement in the production of paralytic shellfish poison toxins, which are normally associated with bloom-forming algal species, specifically toxic dinoflagellate algae. Preliminary reports of the identification of toxin-producing bacteria isolated from the toxic marine dinoflagellate Alexandrium tamarensesuggested that they belonged to the gamma sub-division of the Proteobacteria, specifically related to the bacterium Moraxella. Digoxigenin-labelled alpha, beta and gamma ribosomal rRNA probes, hybridized to both toxigenic and non-toxigenic bacteria isolated from several strains of Alexandrium tamarense, indicated that the bacteria belonged to the alpha sub-division of the Proteobacteria. Phylogenetic analysis of small subunit ribosomal RNA coding regions confirmed this and provided strong evidence that these bacteria are likely to represent a new genus in that group.

A new type of peridinin—chlorophyll aprotein (PCP) was isolated from the marine dinoflagellate Alexandrium cohorticula. Unlike previous studies, PCP was obtained as a single component in the presence of a protease inhibitor. The monomer had a molecular mass of 37 kDa with 12 peridinin molecules associated with 2 chl amolecules. This pigment content was much higher than that reported previously. We observed a partial amino acid sequence of the N‐terminus that is novel among photosynthetic pigment—protein complexes. Magnetic circular dichroism clearly indicated that chl ain PCP had monomeric features. Multiple spectral components were suggested for both chl aand peridinin. Based on the high pigment content, the optical properties were compared with those for a reported PCP containing 4 chl aand 1 peridinin.

Expression of p53 was examined immunohistochemically in the Japanese monkey model with Helicobacter pyloriinfection of the gastric mucosa to investigate the association between H. pyloriinfection and gastric carcinogenesis for a period of 4 years. In the course of these observations, from 3 years after H. pyloriinoculation, nuclear staining for p53 was seen in the glandular cells of the mucosa infected with H. pylori, especially in the neck region of the glands. There was a gradual increase in the number of immunopositive cases among the infected animals. Three years after inoculation, three out of six cases, and 4 years after inoculation, four out of six cases exhibited positive staining for p53. Before inoculation, and up to 2 years after inoculation, the infected group showed no immunoreaction for p53. The non‐infected group likewise displayed no immunostaining for p53 through 4 years of observation. These results suggest that p53 alterations occur in the H. pylori‐infected gastric mucosa and that H. pyloriinfection may play an important role in gastric carcinogenesis.

Two clones ofAlexandrium cohorticula were isolated at Aburatsubo, Sagami Bay, Japan. Cultured cells of both contained high amounts of paralytic shellfish toxins. The toxicity of these isolates was comparable with that of highly toxic Thai clones. No significant difference in toxin components or their proportions was observed between Japanese and Thai strains. The optimum growth temperature of both strains was around 25 °C. Japanese strains survived at 15 °C, whereas Thai strains did not; the latter grew faster than the former at 30 °C.

ABSTRACTSitafloxacin showed MICs of less than or equal to 0.5 μg/ml against 105 isolates of Helicobacter pylori, including 44 isolates with mutations in the gyrAgene. The highest MICs for garenoxacin and levofloxacin were 8 and 64 times, respectively, higher than the highest MICs observed for sitafloxacin.

Background: In Prader-Willi syndrome (PrWS), marked obesity is the most serious and common complication, contributing significantly to morbidity and mortality. Because of the associated psychosocial difficulties, bariatric surgery appears to be the only effective treatment. Case Report: A 30-year-old man with PrWS weighing 108 kg (BMI 50 kg/m2), underwent Roux-en-Y gastric bypass (RYGBP). 3 months before the RYGBP, he weighed 146 kg (BMI 68.5), partly because of heart failure. 18 months after RYGBP, he weighed 92.4 kg (BMI 43.3), with no postoperative complications. Moreover, he showed considerable increase in serum HDL-cholesterol levels with reciprocal reduction in LDL-cholesterol after the surgery. Conclusion: RYGBP resulted in satisfactory weight loss and improvement in serum lipid profile in a Japanese morbidly obese patient with PrWS.

When dark-grown wax-rich cells of Euglena gracllts strain Z are transferred to an inorganic medium and the cell suspension is aerated in the dark, the wax is oxidatively metabolized, providing carbon materials and energy for some dark processes of plastld development. Under these conditions, pyrenoid-like structures (“propyrenoids”) are formed at the sites adjacent to the prolamellar bodies localized in the peripheral region of the proplastid. These Euglena cells were fixed In 1% glutaraldehyde and embedded in Epon. Serial sections were Labeled with antiserum to ribulose-1,5-blsphosphate carboxylase/oxygenase (RuBisCO) followed by protein A-gold. Computer-aided construction of three-dimensional models of proplastids revealed that approximately 80% of total RuBisCO was localized over the propyrenoid region in the proplastids. No deposition was seen when preimmune serum was substituted for immune serum.