196 research outputs found

    Cyclic Strength of Undisturbed Mine Tailings

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    In order to update existing regulations for the seismic design of tailings retention dikes, extensive investigations were undertaken for 15 existing tailings dams throughout Japan. Undisturbed samples procured from the tailings disposal ponds were tested ln the laboratory to determine the cyclic strength of the in-situ tailings deposits. The results of cyclic triaxial tests on these materials are summarized by means of empirical formulae which are recommended for incorporation in the new seismic design code for the tailings dams

    Bacterial-contamination Monitoring

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    Bacterial contamination of dental unit waterlines (DUWLs) was evaluated by using ATP-bioluminescence analysis and conventional culture method. Water samples (n=44) from DUWLs were investigated for heterotrophic bacteria by culture on R2A agar, which ranged from 1.4×103 to 2.7×105 CFU/mL. The ATP-bioluminescence results for DUWL samples were ranged from 6 to 1189 RLU and obtained within one minutes. These results were well correlated with the culture results (r=0.727-0.855). We conclude that differences in the bacterial contamination of each water supply were confirmed by the ATP-bioluminescence assay. This method would be potentially useful for rapid and simple monitoring of DUWL bacterial contamination

    Use of ATP bioluminescence to survey the spread of aerosol and splatter during dental treatment

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    Aerosol and splatter produced during dental treatment (ultrasonic scaling and professional mechanical tooth cleaning) are potential sources of infection. Contamination patterns on the operators’ masks, goggles, chests and gowned right arms, and on the patients’ goggles, before and after dental treatment were investigated by using ATP bioluminescence analysis. Contamination on every surface tested increased significantly after dental treatment. Maximum contamination was found on patients’ goggles. Aerosol and splatter produced during dental treatment thus have the potential to spread infection to operators and patients. ATP bioluminescence is a useful tool for monitoring surface contamination

    General Factors and Dental-Related Risk Factors for Postoperative Pneumonia or Infectious Complications: A Retrospective Study

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    Numerous studies report that perioperative oral care decreases the frequency of postoperative pneumonia or infection. However, no studies have analyzed the specific impact of oral infection sources on the postoperative course, and the criteria for preoperative dental care differ among institutions. This study aimed to analyze the factors and dental conditions present in patients with postoperative pneumonia and infection. Our results suggest that general factors related to postoperative pneumonia, including thoracic surgery, sex (male > female), the presence or absence of perioperative oral management, smoking history, and operation time, were identified, but there were no dental-related risk factors associated with it. However, the only general factor related to postoperative infectious complications was operation time, and the only dental-related risk factor was periodontal pocket (4 mm or higher). These results suggest that oral management immediately before surgery is sufficient to prevent postoperative pneumonia, but that moderate periodontal disease must be eliminated to prevent postoperative infectious complication, which requires periodontal treatment not only immediately before surgery, but also on a daily basis.Isomura E.T., Fujimoto Y., Matsukawa M., et al. General Factors and Dental-Related Risk Factors for Postoperative Pneumonia or Infectious Complications: A Retrospective Study. Journal of Clinical Medicine 12, 3529 (2023); https://doi.org/10.3390/jcm12103529

    Serodiagnosis and Bacterial Genome of Helicobacter pylori Infection

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    The infection caused by Helicobacter pylori is associated with several diseases, including gastric cancer. Several methods for the diagnosis of H. pylori infection exist, including endoscopy, the urea breath test, and the fecal antigen test, which is the serum antibody titer test that is often used since it is a simple and highly sensitive test. In this context, this study aims to find the association between different antibody reactivities and the organization of bacterial genomes. Next-generation sequences were performed to determine the genome sequences of four strains of antigens with different reactivity. The search was performed on the common genes, with the homology analysis conducted using a genome ring and dot plot analysis. The two antigens of the highly reactive strains showed a high gene homology, and Western blots for CagA and VacA also showed high expression levels of proteins. In the poorly responsive antigen strains, it was found that the inversion occurred around the vacA gene in the genome. The structure of bacterial genomes might contribute to the poor reactivity exhibited by the antibodies of patients. In the future, an accurate serodiagnosis could be performed by using a strain with few gene mutations of the antigen used for the antibody titer test of H. pylori

    The Genetic Diversity of Helicobacter pylori Virulence Genes Is Not Associated with Gastric Atrophy Progression

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    Atrophy of the gastric mucosa is a precursor of intestinal-type gastric cancer, and Helicobacter pylori infection causes atrophic gastritis. The aim of this study was to determine whether the genetic diversity of H. pylori virulence genes is associated with the development and progression of gastric atrophy in humans. We isolated and cultured H. pylori strains from patients with gastric ulcer and duodenal ulcer accompanied by atrophic gastritis in background mucosa. H. pylori strains were stored at -80℃ prior to the experiments being carried out. We analyzed iceA, babA, vacA, cagA, and cagE genes by PCR. The cagA gene was analyzed through sequencing of the C-terminal region containing the EPIYA motif, which is related to tyrosine phosphorylation. Severe atrophy was observed in patients with gastric ulcer. The major phenotype of the vacA gene was s1c/m1 (93オ). The cagA gene was detected in all strains. The cagE gene was not detected in 2 and 5 strains from the mild cases and severe cases, respectively. The major cagA EPIYA motif, which is amino acids repeat in the C terminus, was the A-B-D type (44 of 58 strains). The virulence genes were not statistically associated with the severity of atrophy in the background gastric mucosa in humans. Not only identification of bacterial virulence factors but also studies of the host response will be necessary to investigate the progression of gastric atrophy and subsequent cancer development in humans

    Brain MRI with Quantitative Susceptibility Mapping: Relationship to CT Attenuation Values

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    [Background]: Quantitative susceptibility mapping (QSM) is used to differentiate between calcification and iron deposits. Few studies have examined the relationship between CT attenuation values and magnetic susceptibility in such materials. Purpose: To assess the relationship among metal concentration, CT attenuation values, and magnetic susceptibility in paramagnetic and diamagnetic phantoms, and the relationship between CT attenuation values and susceptibility in brain structures that have paramagnetic or diamagnetic properties. [Materials and Methods]: In this retrospective study, CT and MRI with QSM were performed in gadolinium and calcium phantoms, patients, and healthy volunteers between June 2016 and September 2017. In the phantom study, we evaluated correlations among metal concentration, CT attenuation values, and susceptibility. In the human study, Pearson and Spearman correlations were performed to assess the relationship between CT attenuation values and susceptibility in regions of interest placed in the globus pallidus (GP), putamen, caudate nucleus, substantia nigra, red nucleus, dentate nucleus, choroid plexus, and hemorrhagic and calcified lesions. [Results]: Eighty-four patients (mean age, 64.8 years 6 19.6; 49 women) and 20 healthy volunteers (mean age, 72.0 years 6 7.6; 11 men) were evaluated. In the phantoms, strong linear correlations were identified between gadolinium concentration and CT and MRI QSM values (R2 = 0.95 and 0.99, respectively; P , .001 for both) and between calcium concentration and CT and MRI QSM values (R2 = 0.89 [P = .005] and R2 = 0.98 [P , .001], respectively). In human studies, positive correlations between CT attenuation values and susceptibility were observed in the GP (R2 = 0.52, P , .001) and in hemorrhagic lesions (R2 = 0.38, P , .001), and negative correlations were found in the choroid plexus (R2 = 0.53, P , .001) and in calcified lesions (R2 = 0.38, P = .009). [Conclusion]: CT attenuation values showed a positive correlation with susceptibility in the globus pallidus and hemorrhagic lesions and negative correlation in the choroid plexus and calcified lesions

    Quiet Diffusion-weighted MR Imaging of the Brain for Pediatric Patients with Moyamoya Disease

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    PURPOSE: Diffusion-weighted MRI (DWI) is an essential sequence for evaluating pediatric patients with moyamoya disease (MMD); however, acoustic noise associated with DWI may lead to motion artifact. Compared with conventional DWI (cDWI), quiet DWI (qDWI) is considered less noisy and able to keep children more relaxed and stable. This study aimed to evaluate the suitability of qDWI compared with cDWI for pediatric patients with MMD. METHODS: In this observational study, MR examinations of the brain were performed either with or without sedation in pediatric patients with MMD between September 2017 and August 2018. Three neuroradiologists independently evaluated the images for artifacts and restricted diffusion in the brain. The differences between qDWI and cDWI were compared statistically using a chi-square test. RESULTS: One-hundred and six MR scans of 56 patients with MMD (38 scans of 15 sedated patients: 6 boys and 9 girls; mean age, 5.2 years; range, 1-9 years; and 68 scans of 42 unsedated patients: 19 boys and 23 girls; mean age, 10.7 years; range, 7-16 years) were evaluated. MR examinations were performed either with or without sedation (except in one patient). In sedated patients, no artifact other than susceptibility was observed on qDWI, whereas four artifacts were observed on cDWI (P = .04). One patient awoke from sedation during cDWI scanning, while no patient awoke from sedation during qDWI acquisition. For unsedated patients, three scans showed artifacts on qDWI, whereas two scans showed artifacts on cDWI (P = .65). Regarding restricted diffusion, qDWI revealed three cases, while two cases were found on cDWI (P = .66). CONCLUSION: qDWI induced fewer artifacts compared with cDWI in sedated patients, and similar frequencies of artifacts were induced by qDWI and by cDWI in unsedated patients. qDWI showed restricted diffusion comparable to cDWI

    Dynamic modification of sphingomyelin in lipid microdomains controls development of obesity, fatty liver, and type 2 diabetes

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    Susumu Mitsutake, Kota Zama, Hazuki Yokota, Tetsuya Yoshida, Miki Tanaka, Masaru Mitsui, Masahito Ikawa, Masaru Okabe, Yoshikazu Tanaka, Tadashi Yamashita, Hiroshi Takemoto, Toshiro Okazaki, Ken Watanabe, Yasuyuki Igarashi, Dynamic Modification of Sphingomyelin in Lipid Microdomains Controls Development of Obesity, Fatty Liver, and Type 2 Diabetes, Journal of Biological Chemistry, Volume 286, Issue 32, 2011, Pages 28544-28555, ISSN 0021-9258, https://doi.org/10.1074/jbc.M111.255646

    Hemangiopericytoma of the Greater Omentum

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    A 41-year-old Chinese woman was admitted to our hospital with epigastric pain. Computed tomography detected a heterogeneous enhancement tumor fed by the left gastroepiploic artery in the left lower quadrant and cholelithiasis. Excision of the tumor in the greater omentum and cholecystectomy were performed laparoscopically. Histological findings confirmed a diagnosis of hemangiopericytoma with low-grade malignancy. To our knowledge, hemangiopericytoma of the greater omentum is very rare, and only 12 cases were reported in English literature. We report a case of hemangiopericytoma arising in the greater omentum and review the literature
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