A CASE OF RUPTURED MITRAL VALVE ANEURYSM DUE TO INFECTIVE ENDOCARDITIS

58-year-old woman with aortic regurgitation was admitted to our hospi- tal because of high grade fever. She had infective endocarditis and an aneurysm of the anterior mitral leaflet. Doppler echocardiography indicated a ruptured mitral valve aneurysm. Aortic regurgitant flow along the anterior mitral leaflet was suspected to have contributed to mitral valve endocarditis, aneurysm formation and rupture. She was initially treated with high-dose intravenous penicillin, but congestive heart failure worsened. Mitral valve replacement was then successfully performed

Kinetics of Silver Photodiffusion into Amorphous S-Rich Germanium Sulphide – Neutron and Optical Reflectivity

Silver photodiffusion is one of the attractive photo-induced changes observed in amorphous chalcogenides. In this research, we focus on amorphous S-rich germanium sulphide and study the kinetics of the silver photodiffusion by neutron reflectivity, as well as optical reflectivity. It was found from the neutron reflectivity profiles with 30 s time resolution that silver dissolved into the germanium sulphide layer, forming a metastable reaction layer between the Ag and the germanium sulphide layers, within 2 min of light exposure. Subsequently, silver slowly diffused from the metastable reaction layer to the germanium sulphide host layer until the Ag concentration in both layers became identical, effectively forming one uniform layer; this took approximately 20 min. Optical reflectivity reveals the electronic band structure of the sample, complementary to neutron reflectivity. It was found from the optical reflectivity measurement that the metastable reaction layer was a metallic product. The product could be Ag8GeS6-like form, which is regarded as the combination of GeS2 and Ag2S, and whose backbone is composed of the GeS4 tetrahedral units and the S atoms. We attribute the first quick diffusion to the capture of Ag ions by the latter S atoms, which is realised by the S–S bond in amorphous S-rich germanium sulphide, while we attribute the second slow diffusion to the formation of the Ag–Ge–S network, in which Ag ions are captured by the former GeS4 tetrahedral units

Potential Application of Bacteriophages in Enrichment Culture for Improved Prenatal Streptococcus agalactiae Screening

Vertical transmission of Streptococcus agalactiae can cause neonatal infections. A culture test in the late stage of pregnancy is used to screen for the presence of maternal S. agalactiae for intrapartum antibiotic prophylaxis. For the test, a vaginal–rectal sample is recommended to be enriched, followed by bacterial identification. In some cases, Enterococcus faecalis overgrows in the enrichment culture. Consequently, the identification test yields false-negative results. Bacteriophages (phages) can be used as antimicrobial materials. Here, we explored the feasibility of using phages to minimize false-negative results in an experimental setting. Phage mixture was prepared using three phages that specifically infect E. faecalis: phiEF24C, phiEF17H, and phiM1EF22. The mixture inhibited the growth of 86.7% (26/30) of vaginal E. faecalis strains. The simple coculture of E. faecalis and S. agalactiae was used as an experimental enrichment model. Phage mixture treatment led to suppression of E. faecalis growth and facilitation of S. agalactiae growth. In addition, testing several sets of S. agalactiae and E. faecalis strains, the treatment with phage mixture in the enrichment improved S. agalactiae detection on chromogenic agar. Our results suggest that the phage mixture can be usefully employed in the S. agalactiae culture test to increase test accuracy

Objective Methods of 5-Aminolevulinic Acid-Based Endoscopic Photodynamic Diagnosis Using Artificial Intelligence for Identification of Gastric Tumors

Positive diagnoses of gastric tumors from photodynamic diagnosis (PDD) images after the administration of 5-aminolevulinic acid are subjectively identified by expert endoscopists. Objective methods of tumor identification are needed to reduce potential misidentifications. We developed two methods to identify gastric tumors from PDD images. Method one was applied to segmented regions in the PDD endoscopic image to determine the region in LAB color space to be attributed to tumors using a multi-layer neural network. Method two aimed to diagnose tumors and determine regions in the PDD endoscopic image attributed to tumors using the convoluted neural network method. The efficiencies of diagnosing tumors were 77.8% (7/9) and 93.3% (14/15) for method one and method two, respectively. The efficiencies of determining tumor region defined as the ratio of the area were 35.7% (0.0–78.0) and 48.5% (3.0–89.1) for method one and method two, respectively. False-positive rates defined as the ratio of the area were 0.3% (0.0–2.0) and 3.8% (0.0–17.4) for method one and method two, respectively. Objective methods of determining tumor region in 5-aminolevulinic acid-based endoscopic PDD were developed by identifying regions in LAB color space attributed to tumors or by applying a method of convoluted neural network