Recently, the epidemic types of methicillin-resistant Staphylococcus aureus (MRSA) in hospital and community settings in Japan have changed significantly. Before 2010, approximately 80% of the MRSA strains isolated from hospitals were typical healthcare-associated MRSA (HA-MRSA) with staphylococcal cassette chromosome (SCC) mec type II. However, USA400-like community-associated MRSA (CA-MRSA) with SCCmec type IV (defined as USA400/J) has become dominant in hospitals since 2014. By contrast, skin infections caused by the highly virulent CA-MRSA USA300 clone have increased. The USA300 clone is associated with intractable skin infections and necrotizing pneumonia because it carries a cytolytic pore-forming toxin, Panton–Valentine leukocidin (PVL), and an arginine catabolic mobile element that promotes skin colonization. In the past decade, the USA300 clone has shown limited prevalence and has not been considered a serious problem in Japan. However, the USA300 clone has recently spread in community and hospital settings. This review discusses the evolution and current status of the molecular epidemiological features of HA-MRSA and CA-MRSA strains in Japan.

Antimicrobial resistance (AMR) is a serious global concern. AMR pathogens are found in hospitals and communities. Haemophilus influenzae is a common pathogen associated with community-acquired infections. H. influenzae infections are usually treated with β-lactams, macrolides, and quinolones. However, the drug-resistant strains have emerged. The resistance mechanisms of H. influenzae are complex but are roughly characterized by the acquisition of a mutation in antimicrobial-targeting genes and exogenous resistant genes. Generally, the former cannot be transferred horizontally to a susceptible strain. However, several studies have demonstrated that, in the case of H. influenzae, both the former and the latter can be transferred horizontally. In this review, we provide an overview of the bacterial features and antimicrobial resistance of H. influenzae. We also summarize the unique and ingenious antimicrobial resistance mechanisms used by this pathogen based on the findings of recent studies. These are expected to facilitate the understanding of AMR pathogens in the community and develop strategies to combat infections.

The emergence of drug-resistant bacteria has posed a significant problem in medical institutions worldwide. Colistin, which targets lipopolysaccharide (LPS), serves as a last-resort antimicrobial agent against multidrug-resistant Gram-negative bacteria. Nevertheless, Acinetobacter baumannii, a pathogen with a worldwide prevalence of antimicrobial resistance, has been reported to develop resistance to colistin frequently. In this review, we discuss how A. baumannii acquires resistance to colistin, focusing on modification as well as loss of LPS present in its outer membrane, which is the primary mechanism of A. baumannii’s resistance to colistin. Basic and clinical insights regarding colistin resistance in A. baumannii have been discussed in isolation. Therefore, we discuss the relationship between these 2 colistin resistance mechanisms in terms of the frequency and fitness of genetic mutations based on the insights from basic studies and clinical settings. We concluded that understanding the detailed mechanisms of colistin drug resistance requires a comprehensive understanding of both the frequency of mutations and the effects of selection pressure. Finally, we highlight the importance of promoting research from both basic science and clinical perspectives.

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in developing countries and is regularly imported into developed countries as a major cause of traveler’s diarrhea. ETEC is usually self-limiting and not necessarily treated with antimicrobials, although antimicrobial treatment is recommended in malnourished children, severe cases, and traveler’s diarrhea. However, resistant strains to representative therapeutic agents such as ciprofloxacin and azithromycin have been reported in recent years, and multidrug-resistant ETEC has also emerged. This review discusses the recent antimicrobial resistance surveillance in ETEC and the mechanisms of resistance to major antimicrobials.

The rapid emergence of drug-resistant microbes has recently become a major concern in the medical field. In Pseudomonas aeruginosa, one of the most important mechanisms underlying antibiotic resistance is MexAB-OprM system, increases in this efflux system result in greater resistance to a wide range of drugs, and genetic mutations have been identified as a contributing factor. Thus, this study characterized point mutations in the mexB gene that are common to 39 clinical P. aeruginosa isolates obtained from The Pseudomonas Genome Database. Basic Local Alignment Search Tool (BLAST) was used to compare the mexB gene sequences of those 39 strains with PAO1. The majority of these point mutations were silent mutations without amino acid mutations. Mutations 2730, 495, and 2280, which were abundant in the strains examined, were characterized by greater codon usage after the mutation. A positive correlation has been reported between tRNA levels and codon usage in Escherichia coli, and the same relationship may be present in P. aeruginosa. In this study, the silent mutations observed in many strains mainly involved the substitution of C or G, which resulted in a higher codon usage and stronger binding power after than before the mutation. This change is considered advantageous for survival in the human body by increasing the translation efficiency of the MexB protein. Thus, combining the silent mutation identified in this study with information on the expression level of mexB is expected to be used as an indicator to identify multidrug-resistant P. aeruginosa.

We examined whether the glucose levels and awareness of individuals without diabetes changed after using a sensor-based intermittently scanned continuous glucose monitoring (isCGM) system in their daily lives. Japanese individuals without a diabetes diagnosis wore the isCGM system while maintaining a normal lifestyle during the baseline period. A certified diabetes educator coached them on how to improve their lifestyle based on information from sensor data, food journals, and body composition. The participants subsequently consumed a specific diet, exercised for 2 months, and wore a new sensor after the intervention period. A total of 36 Japanese participants were eligible for analysis in this study. The time above range and the area under the curve did not change between before and after the intervention in overall participants. The visual analogue scale scores significantly increased from before to after the intervention in the overall participants. Stratified analysis was performed by dividing the participants into 18 control participants (glycated hemoglobin level <5.7%) and 18 participants with prediabetes (glycated hemoglobin level 5.7–6.4%). The time in range and the area under the curve significantly increased and decreased after the intervention in participants with prediabetes but not in control participants. The visual analogue scale scores significantly increased from before to after the intervention in both control and prediabetes groups individually. Lifestyle modification, along with the use of an isCGM system, is highly effective at preventing type 2 diabetes mellitus, potentially reducing the individual and public health burdens of diabetes, particularly for individuals with prediabetes.

Iodine-based contrast agents can induce various acute hypersensitivity reactions ranging from mild itching or vomiting shortly after administration to severe hypotension or loss of consciousness. In Japan, steroid premedication is commonly used to prevent acute hypersensitivity reactions. However, little clear evidence supporting its efficacy is available. In this study, we evaluated the effectiveness of premedication for acute hypersensitivity reactions induced by nonionic iodine contrast agents using propensity score matching. The participants included patients who were administered nonionic iodine contrast agents at Yokohama City Minato Red Cross Hospital between April 1, 2016 and March 31, 2022. Only first-time patients with no history of hypersensitivity reactions to contrast agents were included. The patients were classified into premedication and non-premedication groups, and the incidence proportions of acute hypersensitivity reactions were compared after matching. Of the 19976 patients, 422 (211 in each group) were matched. In the premedication group, 7 cases (3.32%) of hypersensitivity reactions occurred. In contrast, only 2 cases (0.95%) were observed in the non-premedication group. The odds ratio for the occurrence of hypersensitivity reactions in the premedication group was 3.500 (95% confidence interval, 0.727–16.848), with no significant difference. Therefore, premedication did not demonstrate the efficacy in preventing acute hypersensitivity reactions induced by nonionic iodine contrast agents. Based on the results of this study and guidelines, a recommendation for premedication was not reached for patients with a history of allergies, including asthma and atopy, as well as those with a history of drug or food allergies.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease without efficient treatment. Fuzi has anti-inflammatory and immunomodulatory properties. However, the bioactive compounds and mechanisms of fuzi in the treatment of UC are not completely understood. The active components of fuzi were retrieved from Traditional Chinese Medicine Database System Pharmacology and Analysis Platform; PharmMapper was used to predict the targets of the active components of fuzi; UC-related disease targets were obtained from Online Mendelian Inheritance in Man and Genecards databases, and Venny 2.1 was used to obtain common targets; Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed on the common targets using R 4.0.2. STRING and Cytoscape 3.9.0 was used to construct a protein–protein interaction (PPI) network for the intersection targets. We then determined the role of the candidate molecule from fuzi, Higenamine (Hig), in a mouse model of dextran sulfate sodium (DSS)-induced colitis. In total, 21 active components and 420 corresponding targets of fuzi were obtained, of which 224 common targets were identified by intersecting with UC-related targets. The GO, KEGG, and PPI results suggested that fuzi and Hig may target RAC-alpha serine/threonine-protein kinase (AKT) to regulate the phosphoinositide-3-kinase (PI3K)/AKT pathway in UC. Animal experiments have shown that Hig treatment greatly reduced DSS-induced colitis, as measured by the disease activity index score, colonic inflammation, and intestinal barrier integrity. Mechanistically, Hig downregulated the DSS-induced PI3K–AKT signaling pathway by inhibiting AKT phosphorylation. Altogether, Hig alleviated DSS-induced colitis in mice, possibly by inhibiting colon inflammation and improving the intestinal barrier by regulating the PI3K–AKT signaling pathway. The active component Hig from fuzi is likely to play a role in the treatment of UC.

Toxic advanced glycation end-products (TAGEs) are glyceraldehyde (GA)-derived AGEs with strong cytotoxic effects. TAGEs are also involved in lifestyle-related diseases. Notably, modification of TAGEs by GA causes protein dysfunction. As endothelial nitric oxide synthase (eNOS) is constitutively expressed in vascular endothelial cells and is a source of nitric oxide (NO), we focused on it as a TAGE modification-targeting protein. Our laboratory has reported that Ras guanyl nucleotide-releasing protein 2 (RasGRP2) activates Rap1 and R-Ras, among other small GTPases, and suppresses apoptosis and TAGE-induced vascular hyperpermeability in vascular endothelial cells. Therefore, in this study, we investigated the effects of RasGRP2 on cell death, TAGE formation, and TAGE modification of eNOS in vascular endothelial cells following GA treatment using RasGRP2-overexpressing (R) cells and mock (M) immortalized human umbilical vein endothelial cells. GA treatment decreases the viability of both cell types in a concentration-dependent manner. In M cells, GA treatment increased the formation of TAGEs and TAGE modification of eNOS in a concentration-dependent manner, but this increase was suppressed in R cells. Additionally, co-treatment with aminoguanidine, an inhibitor of AGEs formation, suppressed cell death and TAGE modification of eNOS induced by GA. These results indicate that GA induces cell death, the formation of TAGEs, and TAGE modification of eNOS in vascular endothelial cells. Additionally, RasGRP2 is a protective factor that suppresses TAGE formation.

Although accelerated growth is observed in both sexes upon reaching puberty, the growth of girls ceases around menarche (the average age at menarche is 12–13 years in Japan). However, the molecular basis of the action of estrogen remains unclear. In this study, we investigated whether estrogen is involved in the differences in growth between males and females while focusing on thyroid hormone metabolic enzymes. We analyzed the promoters of iodothyronine deiodinase (DIO)2 and DIO3 by 17β-estradiol (E₂). ATDC5 cells (mouse chondrocytes cell line) were treated with E₂, and the expression of DIO2 and DIO3 mRNA and proteins was evaluated. Sham-operated (sham) or ovariectomized (OVX) female mice were treated daily with E₂ or vehicle for three consecutive weeks. Subsequently, the left femur was removed to evaluate the effect of E₂ on DIO2/DIO3 gene and protein expression. E₂ increased the transcriptional activity of DIO3 in a concentration-dependent manner. On the DIO3 promoter indicates the presence of an estrogen response element. DIO2 and DIO3 mRNA and protein expression in ATDC5 cells in the presence of E₂ was significantly increased, while DIO2 expression was unchanged. In vivo, we used OVX mice and E₂ supplementation as a model of amenorrhea for further investigation. DIO3 expression was significantly increased in mice treated with E₂ in OVX compared to that in mice treated with vehicle in sham. E₂ increases DIO3 expression in chondrocytes and long bone tissues, suggesting that E₂ may affect bone growth and cause sexual dimorphism during puberty.

Trends in opioid use for patients with cancer in Japan remain unclear. This study investigated the prescription trends of strong and weak opioids in Japan and the prescription trends among patients with or without support from a palliative care team. Open data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) and administrative claims data from the University of Yamanashi Hospital from fiscal years 2015 to 2021 were used. Opioid consumption was reported using the defined daily dose (DDD) per 1000 inhabitants per day (DID) and DDD per 100 bed-days. The NDB open data showed a decrease from 0.3111 to 0.2271 in the DID for inpatients (p = 0.0001) and an increase from 0.5971 to 0.8597 in the DID for outpatients (p = 0.0003). Consumption of tramadol, a weak opioid, increased in both inpatient and outpatient settings. In University of Yamanashi Hospital, the annual percentage of opioid consumption changed little among strong opioids (98.1–97.1%) and weak opioids (1.8–2.8%) for patients supported by a palliative care team (p = 0.2842), but changed more noticeably among strong opioids (86.6–69.6%) and weak opioids (13.3–30.3%) for patients without support from a palliative care team (p < 0.001). Opioid prescription patterns in Japan changed during the 7-year study period, which indicated shifts in the types of opioids used. Additionally, the trend in opioid prescriptions was characterized by the presence or absence of palliative care team support.

This study aimed to elucidate the manufacturing process parameters with optimal quality characteristics of protein-encapsulated dioleoylglycerophosphate–diethylenediamine (DOP-DEDA)-based lipid nanoparticles (LNPs) for intracellular protein drug delivery. DOP-DEDA is a pH-responsive and charge-reversible lipid for intracellular cargo delivery. In this study, bovine serum albumin (BSA) was used as a weakly acidic protein model, and LNPs were prepared using microfluidic technology, which has many advantages for practical applications. BSA-encapsulated DOP-DEDA-based LNPs showed pH-responsive charge reversibility and excellent quality characteristics for the intracellular delivery of proteins. A process optimization study was conducted by applying the Box–Behnken design in a design-of-experiment approach. The particle size, ζ-potential, and encapsulation efficiency were evaluated in response to the total flow rate, lipid concentration, and lipid solution ratio. The lipid solution ratio and total flow rate significantly affected the particle size and encapsulation efficiency, respectively. On the contrary, none of the process parameters affected the ζ-potential. Moreover, a map of the predicted values was constructed for the particle size and encapsulation efficiency using a multiple regression equation. In the predicted particle size range of 77–215 nm and encapsulation efficiency of 14–35%, the observed values were close to the predicted values, and 100-nm LNPs were reproduced with an encapsulation efficiency of 27%. Therefore, manufacturing process parameters were established to obtain protein-encapsulated DOP-DEDA-based LNPs with optimal quality characteristics.

In this study, we investigated (1) the functional role of large-conductance Ca²⁺-activated K⁺ (BK_Ca) channels in the regulation of guinea pig vas deferens smooth muscle (VDSM) contractions and (2) the potential contractile effects of 33 physiologically active substances and related chemicals that have not been previously reported to contract VDSM. Iberiotoxin (an inhibitor of BK_Ca channels, 10^–7 M) was the most potent enhancer of both noradrenaline (10^–5 M)- and ATP (10^–6 M)-induced contractions among the 6 types of K⁺ channel inhibitors. In addition, BK_Ca channel mRNA expression was the highest among the 32 types of K⁺ channel mRNAs. Iberiotoxin also enhanced the contractions induced by acetylcholine (10^–6 M), histamine (5 × 10^–5 M), bradykinin (10^–6 M), neurokinin A (10^–6 M), neurokinin B (10^–6 M), and substance P (10^–6 M). In the 33 tested physiologically active substances and related chemicals (15 peptides, 5 amino acids and their derivatives, 11 prostanoid- and isoprostane-related drugs, 1 endocannabinoid, and 1 phospholipid), we found that 3 bombesin-like peptides, neuromedin B (NMB) (10^–6 M), gastrin-releasing peptide (GRP, 10^–8 M), and NMC (10^–6 M), contracted VDSM in the absence of iberiotoxin, and these contractions were strongly enhanced in the presence of iberiotoxin. Among the 3 bombesin receptor subtypes, the mRNA expression level of Grpr (BB₂ receptor) was the highest. These findings suggest that (1) BK_Ca channels are the most powerful negative regulator of VDSM contractility and (2) NMB, GRP, and NMC are physiologically active substances that contract VDSM.

Vitiligo vulgaris is an acquired disorder that is thought to arise from the suppression of melanin synthesis by melanocytes in the basal epidermal layer. To develop therapeutic agents for vitiligo vulgaris, it is critical to identify compounds that promote melanization. In this study, we established a digital image-based method to quantify melanization that does not require biochemical procedures. B16F10 cells were seeded in a white-bottom 96-well microplate. After treatment with or without α-melanocyte-stimulating hormone, followed by fixation of the cells, digital images of the microplates were captured, and the total signal intensity of each well on the image was measured. The extent of melanization in the cells in each well was defined after the subtraction of the signal from the corresponding blank well. This method was found to quantify melanization more sensitively than the conventional technique that measures the absorbance of cell lysates at UV-A wavelengths. We obtained statistical parameters showing that this method was applicable to a high-throughput screening assay; thus, this method appears to be useful for screening and identifying molecules that suppress or promote melanization, the latter of which may be developed as therapeutic agents for vitiligo vulgaris.

Curcumin (CUR), a polyphenol, is a promising compound for use in functional foods owing to various biological properties. However, the kinetics of CUR remains unclear because CUR has extremely low water solubility and absorbability. Here, we tried to elucidate the distribution, metabolism, and excretion of CUR by using amorphous CUR, a novel formulation that has dramatically improved water solubility and absorbability. When amorphous CUR was orally administered, CUR was predominantly distributed in the lungs, spleen, and liver, with low levels of accumulation over 24 h. Moreover, most of the CUR metabolites were observed to be glucuronide and sulfate conjugates. Furthermore, CUR was found to be excreted not only in bile but also in urine. Taken together, we have systematically demonstrated the kinetics of CUR by using a highly absorbable CUR formulation. In order to develop functional foods with high quality, it is important to not only evaluate the function and toxicity of CUR but also to correctly understand its kinetics, such as absorption, distribution, accumulation, metabolism, and excretion.

Gestational diabetes mellitus (GDM) is a glucose metabolism abnormality that first emerges during pregnancy and may negatively affect the behavioral and neurodevelopmental outcomes of offspring. Quetiapine (QUE) has been shown to promote differentiation of oligodendrocyte precursor cells (OPCs) and protect oligodendrocytes and myelination. To explore the effects of QUE on improving the expression of conditioned place preference (CPP) and myelination in the infralimbic cortex (IL) of the medial prefrontal cortex in alcohol-exposed GDM offspring mice, we evaluated CPP expression in 5-week-old alcohol-exposed GDM offspring and treated them with QUE and the extracellular-regulated protein kinase (ERK) inhibitor U0126. Immunohistochemical staining compared the numbers of mature oligodendrocytes, OPCs, and myelin expression levels. Immunofluorescence staining was employed to examine OPC differentiation and the activation of the ERK1/2 signaling pathway. In GDM offspring, CPP expression increased considerably following alcohol exposure, whereas early treatment with QUE or U0126 significantly decreased CPP expression. Meanwhile, alcohol exposure resulted in substantial activation of the ERK1/2 signaling pathway within OPCs in the IL region, as well as a substantial reduction in OPC differentiation, mature oligodendrocyte count, and myelin expression. QUE or U0126 inhibited the activation of the ERK1/2 signaling pathway within OPCs in the IL region of alcohol-exposed GDM offspring and markedly restored OPC differentiation, mature oligodendrocyte numbers, and myelin expression. Collectively, QUE enhanced the differentiation of OPCs in the IL region of GDM offspring after alcohol exposure by regulating the overactivation of the ERK1/2 signaling pathway, thus partially reversing myelination loss and ultimately improving CPP expression.