Investigation of the individual genetic evolution of SARS-CoV-2 in a small cluster during the rapid spread of the BF.5 lineage in Tokyo, Japan

There has been a decreasing trend in new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and fatalities worldwide. The virus has been evolving, indicating the potential emergence of new variants and uncertainties. These challenges necessitate continued efforts in disease control and mitigation strategies. We investigated a small cluster of SARS-CoV-2 Omicron variant infections containing a common set of genomic mutations, which provided a valuable model for investigating the transmission mechanism of genetic alterations. We conducted a study at a medical center in Japan during the Omicron surge (sub-lineage BA.5), sequencing the entire SARS-CoV-2 genomes from infected individuals and evaluating the phylogenetic tree and haplotype network among the variants. We compared the mutations present in each strain within the BA.5 strain, TKYnat2317, which was first identified in Tokyo, Japan. From June 29th to July 4th 2022, nine healthcare workers (HCWs) tested positive for SARS-CoV-2 by real-time PCR. During the same period, five patients also tested positive by real-time PCR. Whole genome sequencing revealed that the infected patients belonged to either the isolated BA.2 or BA.5 sub-lineage, while the healthcare worker infections were classified as BF.5. The phylogenetic tree and haplotype network clearly showed the specificity and similarity of the HCW cluster. We identified 12 common mutations in the cluster, including I110V in nonstructural protein 4 (nsp4), A1020S in the Spike protein, and H47Y in ORF7a, compared to the BA.5 reference. Additionally, one case had the extra nucleotide-deletion mutation I27* in ORF10, and low frequencies of genetic alterations were also found in certain instances. The results of genome sequencing showed that the nine HCWs shared a set of genetic mutations, indicating transmission within the cluster. Minor mutations observed in five HCW individuals suggested the emergence of new virus variants. Five amino acid substitutions occurred in nsp3, which could potentially affect virus replication or immune escape. Intra-host evolution also generated additional mutations. The cluster exhibited a mild disease course, with individuals in this case, recovering without requiring any medical treatments. Further investigation is needed to understand the relationship between the genetic evolution of the virus and the symptoms

Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures : the Denture Adhesive Guideline trial : study protocol for a randomized controlled trial

Background: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. Methods: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. Discussion: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries

Theoretical study on mechanism of the photochemical ligand substitution of fac-[Re-I(bpy)(CO)(3)(PR3)](+) complex

The mechanism of the CO ligand dissociation of fac-[Re-I(bpy)(CO)(3)P(OMe)(3)](+) has theoretically been investigated, as the dominant process of the photochemical ligand substitution (PLS) reactions of fac-[Re-I(bpy)(CO)(3)PR3](+), by using the (TD-)DFT method. The PLS reactivity can be determined by the topology of the T-1 potential energy surface because the photoexcited complex is able to decay into the T-1 state by internal conversions (through conical intersections) and intersystem crossings (via crossing seams) with sufficiently low energy barriers. The T-1 state has a character of the metal-to-ligand charge-transfer ((MLCT)-M-3) around the Franck-Condon region, and it changes to the metal-centered ((MC)-M-3) state as the Re-CO bond is elongated and bent. The equatorial CO ligand has a much higher energy barrier to leave than that of the axial CO, so that the axial CO ligand selectively dissociates in the PLS reaction. The single-component artificial force induced reaction (SC-AFIR) search reveals the CO dissociation pathway in photostable fac-[ReI(bpy)(CO)(3)Cl]; however, the dissociation barrier on the T-1 state is substantially higher than that in fac-[ReI(bpy)(CO)(3)PR3](+) and the minimum-energy seams of crossings (MESXs) are located before and below the barrier. The MESXs have also been searched in fac-[Re-I(bpy)(CO)(3)PR3](+) and no MESXs were found before and below the barrier

Quantitative determination of erlotinib in human serum using competitive enzyme-linked immunosorbent assay

A selective and sensitive competitive enzyme-linked immunosorbent assay (ELISA) method was developed and validated for the quantification of erlotinib in 50 µL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N-succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate. Serum erlotinib concentrations lower than 40 ng/mL were reproducibly measurable using the ELISA. This ELISA was specific to erlotinib and showed very slight cross-reactivity (6.7%) with a major metabolite, O-desmethyl erlotinib. Using this assay, drug levels were easily measured in the blood of mice after oral administration of erlotinib at a single dose of 30 mg/kg. ELISA should be used as a valuable tool for therapeutic drug monitoring and in pharmacokinetic studies of erlotinib. Keywords: Erlotinib, Enzyme-linked immunosorbent assay, O-desmethyl erlotinib, Tyrosine-kinase inhibito

Real-Time Probing of an Atmospheric Photochemical Reaction by Ultrashort Extreme Ultraviolet Pulses: Nitrous Acid Release from o-Nitrophenol

Photolysis of o-nitrophenol, contained in brown carbon, is considered to be a major process for the generation of nitrous acid (HONO) in the atmosphere. In this Letter, we used time-resolved photoelectron spectroscopy with 29.5 eV probe pulses and ab initio calculations to disentangle all reaction steps from the excitation to the dissociation of HONO. After excitation, intersystem crossing to the triplet manifold follows ultrafast excited-state intramolecular hydrogen transfer, where the molecules deplanarizes and finally splits off HONO after 0.5-1 ps

Light-Microscopic Immunocytochemistry for Gentamicin and Its Use for Studying Uptake of the Drug in Kidney▿

Gentamicin (GM) is a widely used antibiotic but shows renal toxicity. We produced a serum against GM (anti-GM) conjugated to bovine serum albumin with N-(gamma-maleimidobutyryloxy)succinimide. The antiserum was monospecific for GM and did not cross-react with the analog streptomycin, tobramycin, kanamycin, or amikacin. The antiserum also detected glutaraldehyde-fixed GM, and this enabled us to develop an immunocytochemical method for detecting the uptake of GM in rat kidney. Twelve hours after a single intravenous administration of GM, immunocytochemistry revealed that GM accumulated in the S1, S2, and S3 segments of the proximal tubules, as well as in the distal tubules and collecting ducts. By 12 h after injection, the drug was detected in cytoplasmic granules of the proximal tubule cells. However, early (1 h) after injection, drug accumulation was detected in the microvilli of these cells. The distal tubules and collecting ducts contained scattered swollen cells, reminiscent of necrotic cells, in which both the nuclei and the cytoplasm reacted strongly with GM. No staining occurred in the kidneys of saline-injected control rats. These results agree with previous studies showing that GM is endocytosed in the proximal tubules and accumulates in lysosomes. Additionally, our results show that GM also accumulates in the distal tubules and collecting ducts. This was achieved by systematically varying the pretreatment conditions—an approach necessary for detecting GM in different subcellular compartments. This approach should be useful for accurately detecting the uptake and toxicity of the antibiotic in different tissues