Immunoassays enable the sensitive determination of various compounds and have been widely utilized in pharmaceutical and medical sciences. To develop practical assays, it is essential to obtain antibodies that capture the target analytes with high specificity and affinity. To date, we have generated high-performance antibodies and developed immunoassays for determining bioactive compounds, particularly focusing on haptens, such as steroids and synthetic drugs. In previous studies, we have produced specific anti-hapten antibodies by immunizing animals with reasonably prepared hapten–carrier conjugates. However, the resulting antibodies sometimes lacked sufficient affinity for a sensitive determination. Therefore, we challenged genetic engineering to produce artificially modified antibodies with improved affinity. Therein, native antibodies with insufficient affinities were converted into single-chain Fv fragments (scFvs), to which random point mutations were introduced to generate diverse scFv libraries. Mutated scFv species with increased affinities were selected and isolated with the aid of phage-display system combined with panning. Using this strategy, we obtained scFvs specific to several haptens, such as estradiol-17β (E₂) and cotinine, that show significantly improved affinity (K_a) than that of the parental scFv, enabling more sensitive enzyme-linked immunosorbent assays. However, the panning step often fails in straightforward selection and requires laborious trial-and-error work. Thus, we developed a “clonal array profiling (CAP)” system for more efficient isolation of the mutants with enhanced affinities, which successfully functioned generating multiple anti-cortisol scFvs with the K_a improved up to 63-fold and an anti-E₂ scFv with 372-fold larger K_a. In this study, we identified new strategies that allow for efficient site-directed mutagenesis to improve affinity. We expect that the engineered antibodies described here will open the door to next-generation immunoassays that will enable simpler and more reliable determination of bioactive compounds.

Epstein–Barr virus (EBV) is one of the most pervasive viruses worldwide, and EBV infection is inextricably linked to a multitude of lymphoid and epithelial neoplasms. EBV is responsible for the advancement of malignant disease by modifying the tumor microenvironment (TME), which is a sophisticated and evolving system that facilitates tumor growth, invasion, and metastasis. EBV infection has a profound impact on the cellular and noncellular components that constitute the TME. Our review presents a summary of the composition of the EBV-remodeled TME, with a particular focus on EBV-induced functional phenotypes in non-tumor cells. Furthermore, we discuss the potential for reversing EBV-driven TME remodeling as a therapeutic strategy for treating the malignancies associated with EBV infection.

Herbal medicines are widely used in clinical practice. Several herbal medicines are prescribed in clinical practice to improve mental symptoms. Yokukansan is an effective prescription for irritability and aggression, which are behavioral and psychological symptoms of dementia (BPSD) or autism spectrum disorder (ASD). However, because herbal medicines contain many components, their pharmacological effects have not been analyzed in detail. Risperidone and quetiapine are prescribed in severe cases; however, their side effects of oversedation are problematic. Tokishigyakukagoshuyushokyoto (TSGST) is a herbal medicine prescribed to improve blood circulation and relieve headaches, back pain, or chilblains associated with hemodynamic insufficiency. Interestingly, most of the individual components of TSGST are known to exert sedative or analgesic effects. In this study, we investigated whether TSGST ameliorates aggressive behavior induced by social isolation in mice. The mice were isolated for 5 or 6 weeks immediately after weaning and given TSGST via a water bottle during this period. Long-term administration of TSGST suppressed the onset of aggression induced by isolation rearing. This aggressive phenotype was significantly reversed by intraperitoneal (i.p.) administration of the 5-hydroxytryptamine 1A (5-HT_1A) receptor antagonist WAY-100635 in TSGST-isolated mice. We also showed that TSGST had similar effects as risperidone, a commonly used antipsychotic for irritability and aggression. These results suggest that TSGST may be effective for irritability or aggression in BPSD or ASD.

The rates of risperidone in precipitates from 5 risperidone oral solutions and tea beverages (green, black, and oolong teas) against risperidone used were measured by quantitative (q)NMR, indicating that as the amount of caffeine in the beverages increased, the rate decreased significantly. A solution of caffeine (0, 5, 10, and 30 μmol) in tartaric acid buffer (pH 3.0) was added to a solution of risperidone and (−)-epigallocatechin-3-O-gallate (EGCg) (each 3.0 μmol) in tartaric acid buffer (pH 3.0). Judging from the amounts of risperidone and EGCg in the precipitates, it was considered that risperidone formed a 1 : 1 complex with EGCg. As the amount of caffeine increased, the amounts of risperidone and EGCg in precipitates decreased significantly, suggesting that caffeine has a solubilizing effect on precipitates of the 1 : 1 complex of risperidone and EGCg. Furthermore, the amount of risperidone in precipitates formed when compounds with a xanthine derivative, such as diprophylline, theobromine, and theophylline, were added was less than when they were not added, indicating that such compounds with a xanthine derivative have the same solubilizing effect as caffeine on precipitate of the 1 : 1 complex of risperidone and EGCg.

Astragalus polysaccharide (APS) is a biologically active water-soluble polysaccharide extracted from stems or roots, which has been proven to have antiaging effects. The aim of this study was to investigate the effects of APS on cognitive function in d-galactose (d-gal)-induced aging rats and explore the potential underlying molecular mechanisms. The rats were induced to age by intraperitoneal injection with 400 mg/kg/d d-gal for 8 weeks. Aging of rats was assessed through the Morris water maze test, step-down test, open field test, and grip strength test. Pathological changes in the hippocampal CA3 and CA1 regions were determined by Hematoxylin and eosin and Nissl staining. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and total antioxidant capacity (T-AOC) in the serum were measured. Telomere length, dual oxidase 1 (Duox1), dual oxidase 2 (Duox2), peroxiredoxin 1 (Prdx1), p21, p16, p53, telomerase reverse transcriptase (TERT), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), nicotinamide phosphoribosyl transferase (NAMPT), and sirtuin 1 (SIRT1) were detected via real-time PCR, Western blotting, and immunohistochemical staining. The results indicated that APS ameliorated the general status in d-gal-induced aging rats, mitigated neuronal degeneration in the CA3 and CA1 regions, reduced the oxidative stress levels, modulated senescence-related β-GAL and protein expression, and maintained telomere length. Furthermore, APS significantly reduced p53 expression and increased p-PI3K, p-AKT, NAMPT, SIRT1, and TERT expression. Therefore, d-gal-induced aging and cognitive impairment in rats can be prevented by APS, likely through regulation of the TERT/p53 signaling axis via the PI3K/Akt and NAMPT/SIRT1 signaling pathways.

This study aimed to clarify the optimal value for the unbound cefmetazole concentration to remain above the minimum inhibitory concentration (MIC) (fT ≥ MIC) for efficacy of de-escalation to cefmetazole in patients with bacteremic urinary tract infection by extended-spectrum β-lactamase-producing Escherichia coli. This double-center retrospective observational study was conducted at Tokyo Bay Urayasu Ichikawa Medical Center and Keio University Hospital from January 2012 to October 2022. Efficacy was determined via clinical evaluation (mortality rate, recurrence rate, vital changes) and bacteriological evaluation, and the optimal fT ≥ MIC was calculated via receiver operating characteristic curve analysis. As a result, the number of patients evaluated were 40 (35 and 5 in the treatment success and treatment failure groups, respectively). Univariate analysis showed that fT ≥ MIC, recurrence rate, and MIC for cefmetazole against bacteria were significantly different for the two groups (p < 0.05). Receiver operating characteristic curve analysis showed that the optimal fT ≥ MIC indicating efficacy was 57% (area under the curve: 0.94, 95% confidence interval: 0.86–1.00, p = 0.002). All patients with fT ≥ MIC ≥ 57% had successful treatment, whereas the frequency of treatment failure was high among those with fT ≥ MIC <57%. The optimal fT ≥ MIC for the clinical efficacy of de-escalation to cefmetazole in patients with bacteremic urinary tract infection by extended-spectrum β-lactamase-producing E. coli was fT ≥ MIC ≥ 57%. This finding would be useful for optimal dosing of cefmetazole.

The central histamine system is involved in several physiological behaviors and neurological disorders, including the sleep–wake cycle, anxiety-related behaviors (both high and low anxiety), and attention deficit hyperactivity disorder (ADHD). Histamine is synthesized from l-histidine by histidine decarboxylase (HDC) and primarily metabolized by histamine-N-methyltransferase (HNMT) in the central nervous system. We previously reported that mice with intermittent sleep deprivation may exhibit impulsive-like symptoms resembling ADHD and low-anxiety behavior. However, the specific role of histaminergic systems in these behaviors remains unclear. In this study, we evaluated HDC expression levels in the hypothalamus as well as the expression of histamine H1 to H4 receptors and HNMT in the hypothalamus and frontal cortex of sleep-deprived mice. Moreover, the effects of administering histidine, a histamine precursor, and inhibitors of each histamine receptor on sleep deprivation-induced low-anxiety and impulsive-like behaviors were examined using an elevated plus maze test. The expressions of HDC and histamine H1 and H3 receptors in the hypothalamus increased, while that of histamine H1 receptors in the frontal cortex of sleep-deprived mice decreased. The low-anxiety and impulsive-like behaviors in intermittent sleep-deprived mice significantly decreased and increased, respectively, following the administration of histamine H1 and H3 receptor blockers and histidine. Collectively, these findings suggest that the low-anxiety behavior and impulsive-like ADHD symptoms induced by intermittent sleep deprivation may result from the overstimulation of histamine H1 and H3 receptors by elevated histamine, together with increased hypothalamic HDC expression. Furthermore, they suggest that sufficient sleep may contribute to ameliorating ADHD symptoms.

Pulmonary arterial hypertension (PAH) is a progressive disorder that lacks a validated and effective therapy. Thus, further investigation of the pathogenesis of PAH will help explore novel treatments. The increase in T helper 17 (Th17) cell-mediated pro-inflammatory response and reduction of regulatory T (Treg) cell-mediated anti-inflammatory effect exacerbates PAH progression. Increasing evidence indicates that 5-hydroxytryptamine (5-HT) is closely related to Th17 and Treg polarization. Here, a decrease of 5-HT was found in hypoxia-induced CD4 + T cells. Hypoxia also resulted in a reduction in Treg cells and an increase in Th17 cells, but the addition of 5-HT rescued Th17/Treg balance, confirming that hypoxia destroyed Th17/Treg balance by inducing a 5-HT decrease. Furthermore, we found that 5-HT-restored Th17/Treg balance mitigated primary pulmonary artery smooth muscle cell (PASMC) proliferation, migration, and contraction, which are important factors in vascular remodeling in PAH. In summary, our findings demonstrate that hypoxia-induced 5-HT decline interferes with the balance of Th17/Treg, which affects the biofunction of PASMCs, thus accelerating PAH development. 5-HT-mediated Th17/Treg balance is expected to act as a novel immunotherapy for PAH treatment.

In rats, platelet-activating factor (PAF) has been reported to increase mechanical activity in various gastrointestinal smooth muscles (SMs) except for esophagus SM. The aim of this study was to examine whether PAF increases mechanical activity in rat esophagus longitudinal SM (LSM) and to compare PAF actions in esophagus LSM with those in other gastrointestinal LSMs. PAF (10⁻⁹–10⁻⁶ M) increased esophagus LSM mechanical activities in a concentration-dependent manner; PAF mainly elicited basal tension increases that were almost eliminated by a PAF receptor antagonist CV-6209 (10⁻⁵ M; against 10⁻⁶ M PAF). In the LSM of the gastric fundus, which is similar to esophagus LSM in that it is derived from the foregut during development, PAF (10⁻⁶ M) increased basal tension to a comparable, albeit significantly different, magnitude as in esophagus LSM. In contrast, in LSMs of the duodenum–jejunum, ileum, and ascending colon, which are derived from the midgut, and the descending colon, which is derived from the hindgut, the ability of PAF (10⁻⁶ M) to increase basal tension was less than that in esophagus and gastric fundus LSMs. Interestingly, in ascending colon LSMs, PAF (10⁻⁶ M) induced oscillatory contractions with a small increase in basal tension. PAF-induced contractions were positively correlated with the mRNA expression levels of the PAF-degrading enzymes Pafah2 (R = 0.82) and Pafah1b3 (R = 0.51). These results suggest that PAF strongly stimulates mechanical activities that are mainly accompanied by basal tension increases in rat LSMs of the gastrointestinal tracts that are derived from the foregut during embryogenesis.

Multidrug-resistant bacteria pose a major challenge in healthcare, and antimicrobial stewardship teams (ASTs) play a crucial role in optimizing antimicrobial use, particularly for last-resort drugs like meropenem (MEPM) and tazobactam/piperacillin (TAZ/PIPC). This study evaluated the impact of enhanced interventions, which included a hospital-wide policy restricting MEPM and TAZ/PIPC use to 5 d and mandating pre-treatment culture testing. A before-and-after study was conducted at a public hospital in Japan, comparing the pre- (June 2021–May 2022) and post-enhanced intervention (June 2022–May 2023) periods. The primary outcome was days of therapy (DOT) per 1000 patient days for MEPM and TAZ/PIPC. Secondary outcomes included antimicrobial use density (AUD), monthly number of patients receiving MEPM and TAZ/PIPC, 30-d mortality, and AST intervention proposals. Overall, 1896 patients received MEPM (pre: 591; post: 527) or TAZ/PIPC (pre: 411; post: 367). As a result, MEPM DOT decreased from 19.4 to 17.2 per 1000 patient days (p = 0.019), and AUD from 14.4 to 11.7 defined daily doses per 1000 patient days (p = 0.017). TAZ/PIPC DOT remained unchanged (p = 0.219), while AUD decreased from 8.7 to 7.6 (p = 0.046). Furthermore, the monthly number of patients receiving MEPM and TAZ/PIPC and their 30-d mortality showed no significant change. AST proposals increased from 209 to 359 for MEPM and from 116 to 238 for TAZ/PIPC (both p < 0.001). In conclusion, enhanced interventions effectively reduced MEPM use without increasing TAZ/PIPC use or worsening 30-d mortality, suggesting that structured guidelines may enhance antimicrobial stewardship in resource-limited settings.

Nephropathy II Decoction (NED) is a widely used Chinese medicinal formulation for managing chronic kidney disease (CKD). Despite its extensive application, the precise mechanisms underlying its therapeutic effects remain poorly understood. This study aims to elucidate the role of NED in attenuating renal fibrosis and to explore its impact on the gut-kidney axis. The principal constituents of NED were analyzed using ultra-performance LC-tandem mass spectrometry (UPLC-MS/MS). A bilateral renal ischemia-reperfusion injury (bIRI) model was employed to induce fibrosis. RT-qPCR was utilized to assess the expression of mRNA related to the toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) and nuclear factor-κB (NF-κB) signaling pathway. Western blotting analysis was performed to identify changes in renal fibrosis markers, TLR4/MyD88/NF-κB pathway proteins, and the colon proteins ZO-1 and Occludin-1. Serum levels of uremic toxins were quantified using enzyme-linked immunosorbent assay (ELISA), and 16S ribosomal RNA (rRNA) gene sequencing was conducted to explore changes in the gut microbiome of the mice. Our study demonstrated that mice in the NED group exhibited reduced serum creatinine, blood urea nitrogen, and urinary protein levels, alongside improvements in kidney damage and a decrease in renal fibrosis markers. In the bIRI group, TLR4/MyD88/NF-κB protein and mRNA levels, as well as intestinal tight junction proteins and enterogenic uremic toxins, were significantly reduced. NED treatment reversed these changes and modified the gut microbiota. Furthermore, fecal microbial transplantation (FMT) alleviated kidney damage and fibrosis in bIRI mice. In summary, NED ameliorates kidney injury and fibrosis by modulating the gut microbiota and may further attenuate fibrosis through the inhibition of TLR4 expression, thereby influencing the gut-kidney axis.

Transmembrane protein 16F (TMEM16F), identified as the causative gene for Scott syndrome, which causes blood coagulation disorders, is known to function as not only a scramblase that bi-directionally transports phospholipids in the lipid bilayer but also a Ca²⁺-activated ion channel with low intracellular Ca²⁺ sensitivity. However, how the dual functions of TMEM16F are controlled remains poorly understood. In this study, we investigated the properties of amino acid residues in human TMEM16F involved in the linkage between phospholipid and ion transports and the regulation of their transports using flow cytometry and whole-cell patch-clamp recordings. We demonstrated that ion and phospholipid transports induced by elevation of intracellular Ca²⁺ concentration were tightly coupled in human embryonic kidney HEK293T cells overexpressing wild-type TMEM16F or its mutants. Mutations of amino acid residues in the hydrophilic subunit cavity of TMEM16F indicated that both substrates were transported through its subunit cavity. Importantly, the tail current analysis suggests that conformational changes of TMEM16F by the channel gating are required for its phospholipid transport. These results suggest that ion channel activities of human TMEM16F modulate its scramblase activities.