Cross-adaptation between Olfactory Responses Induced by Two Subgroups of Odorant Molecules

It has long been believed that vertebrate olfactory signal transduction is mediated by independent multiple pathways (using cAMP and InsP3 as second messengers). However, the dual presence of parallel pathways in the olfactory receptor cell is still controversial, mainly because of the lack of information regarding the single-cell response induced by odorants that have been shown to produce InsP3 exclusively (but not cAMP) in the olfactory cilia. In this study, we recorded activities of transduction channels of single olfactory receptor cells to InsP3-producing odorants. When the membrane potential was held at −54 mV, application of InsP3-producing odorants to the ciliary region caused an inward current. The reversal potential was 0 ± 7 mV (mean ± SD, n = 10). Actually, InsP3-producing odorants generated responses in a smaller fraction of cells (lilial, 3.4%; lyral, 1.7%) than the cAMP-producing odorant (cineole, 26%). But, fundamental properties of responses were surprisingly homologous; namely, spatial distribution of the sensitivity, waveforms, I-V relation, and reversal potential, dose dependence, time integration of stimulus period, adaptation, and recovery. By applying both types of odorants alternatively to the same cell, furthermore, we observed cells to exhibit symmetrical cross-adaptation. It seems likely that even with odorants with different modalities adaptation occurs completely depending on the amount of current flow. The data will also provide evidence showing that olfactory response generation and adaptation are regulated by a uniform mechanism for a wide variety of odorants

Synthesis and pharmacological characterization of potent, selective, and orally bioavailable isoindoline class dipeptidyl peptidase IV inhibitors

Focused structure-activity relationships of isoindoline class DPP-IV inhibitors have led to the discovery of 4b as a highly selective, potent inhibitor of DPP-IV. In vivo studies in Wistar/ST rats showed that 4b was converted into the strongly active metabolite 4l in high yield, resulting in good in vivo efficacy for antihyperglycemic activity

In Vivo Simultaneous Imaging of Vascular Pool and Hypoxia with a HT-29 Tumor Model: the Application of Dual-Isotope SPECT/PET/CT

Investigation of vascularity and hypoxia in tumors is important in understanding cancer biology to developthe therapeutic strategies in cancer treatment. ------------------------------------------------------------------------ *Corresponding author . Recently, an imaging technology with the VECTor SPECT/PET/CT small-animal scanner (MILabs) has been developed to obtain simultaneous images usingtwodifferent tracers labeled with SPECT and PET nuclides, respectively. In this study, we developed amethod to simultaneously visualize vascularity and hypoxia witha human colon carcinoma HT-29tumor-bearing mouse model with 99mTc-labeled human serum albumin (99mTc-HSA) to detect blood pool, and 64Cu-diacetyl-bis (N4-methylthiosemicarbazone) (64Cu-ATSM) to detect the over-reduced conditionsunder hypoxia, by applying this SPECT/PET/CT technology.Prior to the in vivo experiments, a phantom study was conducted to confirmquantitativity of the 99mTc/64Cu dual-isotope imaging with the SPECT/PET/CT system,by comparing radioactivities detected by SPECT/PET/CT system and those of standards under the conditions of wide range of radioactivities and various content ratios, in our settings. An in vivoimaging study was conducted with HT-29 tumor-bearing mice. Both 64Cu-ATSM (37 MBq) and 99mTc-HSA (18.5 MBq) were intravenously injected into a mouse (n = 4) at 1 h and 10 min, respectively, before scanning for 20 min; the 99mTc/64Cu dual-isotope SPECT/PET/CT images were then obtained.The phantom study demonstrated that this system has high quantitativity, even when 2 isotopes co-existed and the content ratio was changed over a wide range, indicating the feasibility for in vivo experiments. In vivoSPECT/PET/CT imaging with 64Cu-ATSM and 99mTc-HSA visualized the distribution of each probe and showed that 64Cu-ATSM high-uptake regions barely overlapped with 99mTc-HSA high-uptake regions within HT-29 tumors.We developed a method to simultaneously visualize vascularity and hypoxia within HT-29tumors using in vivodual-isotope SPECT/PET/CT imaging. This methodology would be useful for studies oncancer biology with mouse tumor models anddevelopment of the treatment strategies against cancer. Examination of vascularity and hypoxia within in vivotumors is important in understanding the biology of cancer anddevelopmentof the therapeutic strategies in cancer treatment. For hypervascular tumors, antiangiogenic therapy and antivascular therapy are promising approaches. For antiangiogenic therapy, the anti-vascular endothelial growth factor antibody bevacizumab is now clinically used worldwide [1-4], and for antivascular therapy, a clinical trial withcombrestatin A4 phosphate is conducted[5]. For hypovascular tumor, which is usually associated with hypoxia, intensive treatment is necessary, since tumor hypoxia is reportedly resistant to chemotherapy and radiotherapy [6-8]. In recent years, several therapeutic methods have been proposedto damage to hypoxic regions within tumors, such as intensity modulated radiation therapy with hypoxia positron emission tomography (PET) imaging [9, 10], and carbon-ion radiotherapy, which is able to damage tumor cells even in the absence of oxygen by high linear energy transfer beam [11, 12]. However, considering the difficulty of cancer radical cure at the present moment, more effective drugs and treatment methods for antiangiogenic, antivascular, and antihypoxia therapies need to be developed. In addition, combinations of these therapies would be effective approaches, since they can attacktumor vascularity and hypoxia closely linked each other.However, it is still difficult to observe tumor vascularity and hypoxia both coincidently and concisely in in vivo tumor-bearing mouse model. Recently, a technology of single-photon emission computed tomography/positron emission tomography/computed tomography(SPECT/PET/CT) imaging with the VECTor small-animal scanner, launched from MILabs (Utrecht, Netherlands), has been reportedto obtain truly simultaneous images with twotracers labeled with SPECT and PET nuclides, respectively. Conventionally, dual-isotope imaging studies with SPECT and PET have been performed by obtaining each image independently with 2 separate systems [13, 14]. In contrast, the VECTor system is equipped with a clustered pinhole collimator, which dramatically reduces pinhole-edge penetration of high-energy annihilation ?-photons from PET nuclides and enables it to detect high-energy ?-photons derived from PET nuclides, in a manner similar to SPECT nuclides, and to obtain high-resolution images from positron emitters and single-photon emitters at the same time by separating the images based on the photon energy [15, 16]. Thus, this system has a novel concept to make images of PET nuclides, compared to the typical PET system, which measures the coincidence of annihilation ?-photons. Goorden et al. have reported that this system shows high spatial resolution, with 0.8 mm for PET nuclides and 0.5 mm for SPECT nuclides [15]. Miwa et al. also confirmed its performance in simultaneous detection of 99mTc and 18F using this system [17]. In this study, we developed a methodology to easily observe intratumoralvascularity and hypoxia in a simultaneous manner,by applyingthis SPECT/PET/CT technology. We used 99mTc-labeled human serum albumin (99mTc-HSA) labeled with a SPECT nuclide 99mTc (half-life = 6.0 h; 140 keV ?-ray: 89%) to visualize tumor vascularity by detecting blood pool [18]. The 99mTc-HSAhas been reported to detect tumor blood pool in many types of cancer, including colon cancer, renal cell carcinoma, and liver tumor in both preclinical and clinical studies [19-21]. We also used 64Cu-diacetyl-bis (N4-methylthiosemicarbazone) (64Cu-ATSM), labeled with a PET nuclide 64Cu (half-life = 12.7 h; ?+-decay: 17.4%; ??-decay: 38.5%; and electron capture: 43%) [22], to detect tumor hypoxia. The Cu-ATSM, labeled with Cu radioisotopes, such as 60Cu, 62Cu, and 64Cu, has been developed as an imaging agent targeting hypoxic regions in tumors for use with PET [23-26].Many studies have demonstrated that Cu-ATSM accumulation is associated with hypoxic conditions of tumor in vitro and in vivo[26-29]. The mechanism of radiolabeled Cu-ATSM accumulation has been studied: Cu-ATSM has small molecular sizeand high membrane permeability, and thus rapidly diffuses into cells and is reduced and trapped within cells under highly reduced intracellular conditions such as hypoxia [24, 29-31]. A clinical study with 62Cu-ATSM demonstrated that high levels of hypoxia-inducible factor-1? (HIF-1?) expression were found in Cu-ATSM uptake regions in the tumors of patients with glioma [32]. In this study, we performed simultaneous in vivo imaging using a SPECT/PET/CT with 99mTc-HSA and 64Cu-ATSM for detecting tumor vascularity and hypoxia with a HT-29 tumor-bearing mouse model

Rosmarinic acid is a novel inhibitor for Hepatitis B virus replication targeting viral epsilon RNA-polymerase interaction

Current therapeutics for hepatitis B virus (HBV) patients such as nucleoside analogs (NAs) are effective; however, new antiviral drugs against HBV are still desired. Since the interaction between the epsilon (c) sequence of HBV pregenomic RNA and viral polymerase (Pot) is a key step in the HBV replication cycle, we aimed to identify small compounds for its inhibition, and established a pull-down assay system for the detection of c-RNA-binding-Pol. Screening showed that 5 out of 3,965 compounds inhibited c-Pol binding, and we identified rosmarinic acid, which exhibited specificity, as a potential antiviral agent. In order to examine the anti-HBV effects of rosmarinic acid, HBV-infected primary human hepatocytes from a humanized mouse liver were treated with rosmarinic acid. The rosmarinic acid treatment decreased HBV components including the amounts of extracellular HBV DNA with negligible cytotoxicity. We also investigated the combined effects of rosmarinic acid and the NA, lamivudine. rosmarinic acid slightly enhanced the anti-HBV activity of lamivudine, suggesting that the HBV replication step targeted by rosmarinic acid is distinct from that of NA. We analyzed an additional 25 rosmarinic acid derivatives, and found that 5 also inhibited c-Pol. Structural comparisons between these derivatives implied that the "two phenolic hydroxyl groups at both ends" and the "caffeic acid-like structure" of rosmarinic acid are critical for the inhibition of c-Pol binding. Collectively, our results demonstrate that rosmarinic acid inhibits HBV replication in HBV-infected cells by specifically targeting c-Pol binding

Exploring the association between number of teeth, food intake, and cognitive function: A 9-year longitudinal study

Mameno T., Moynihan P., Nakagawa T., et al. Exploring the association between number of teeth, food intake, and cognitive function: A 9-year longitudinal study. Journal of Dentistry 145, 104991 (2024); https://doi.org/10.1016/j.jdent.2024.104991.Objectives: This study aimed to investigate the association between the number of teeth, food intake, and cognitive function in Japanese community-dwelling older adults. Methods: This 9-year longitudinal study included a total of 293 analyzable participants who participated in baseline and follow-up surveys. Dental status (number of teeth and periodontal pocket depth), dietary assessment using the brief-type self-administered diet history questionnaire, cognitive function, and the following confounding factors were evaluated: educational level, financial satisfaction, living situation, smoking and drinking habits, history of chronic diseases, apolipoprotein E-ε4 carrier, body mass index, handgrip strength, instrumental activities of daily living, and depressive symptomatology. The Japanese version of the Montreal Cognitive Assessment was used to evaluate cognitive function. A multinomial logistic regression analysis for the intake level of each food categorized into three groups (low, moderate, high), and a generalized estimating equation (GEE) for cognitive function over nine years were performed. Results: After controlling for confounding factors, the number of teeth was shown to be associated with the intake of green-yellow vegetables and meat. Furthermore, the GEE indicated that the lowest quartile of intake of green-yellow vegetables significantly associated with lower cognitive function (unstandardized regression coefficient [B] = -0.96, 95 % confidence interval [CI]: -1.72 to -0.20), and the lowest quartile of intake of meat significantly associated with lower cognitive function (B = -1.42, 95 % CI: -2.27 to -0.58). Conclusions: The intake of green and yellow vegetables and meat, which is influenced by the number of teeth, was associated with cognitive function in Japanese community-dwelling older adults. Clinical Significance: There are few studies that have examined the association between oral health, food intake, and cognitive function. This 9-year longitudinal study suggests that it is important to maintain natural teeth to enable the functional means to consume green-yellow vegetables and meat, and thereby help maintain cognitive function