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Background and Objective: Previous reports of the reduction of fluoride concentrations in fluoridated water by domestic water treatment systems have indicated that further supplementation with fluoride is required. However, the absorption of fluoride by filters has not yet been directly identified. If these filters do not absorb fluoride, further fluoride supplementation may increase fluorosis. In this study, we determined whether filtering systems absorb fluoride ions. Materials and Methods: We directly measured the amounts of fluoride absorbed by activated-carbon filters or hollow-fibre membrane filters using pyrohydrolysis of the filters and flow-injection analysis, the sensitivity of which is more than 100 times greater than that of conventional methods. We made fluoride solutions of pure or tap water and determined changes in fluoride concentration as a result of filtering with a fluoride electrode. Results: Hollow-fibre membrane filters did not affect fluoride concentrations in the fluoridated water, but activated-carbon filters removed some fluoride, especially from the pure-water solution. Filtering a pure-water solution with a fluoride concentration of 0.8 mg F/L reduced the fluoride concentration until 210 L of the solution had been filtered. However, filtering a tap-water solution of 0.8 mg F/L reduced the fluoride concentration only until 8 L had been filtered. The concentration of absorbed fluoride in the filter at 10 L of filtration was 4.7 mg/kg activated carbon. Conclusion: Further fluoride supplementation of fluoridated water should not be necessary, regardless of whether an activated-carbon or hollow-fibre membrane filter is installed on a domestic water treatment system. [ABSTRACT FROM AUTHOR]

Patients with rheumatoid arthritis (RA) accumulate prematurely aged T cells that have acquired a new profile of regulatory receptors. Many of the de novo–expressed receptors are typically found on natural killer cells, including CX3CR1, the receptor for the chemokine fractalkine (FKN). This study explored whether interactions between CX3CR1 and FKN are relevant for T cell functions in rheumatoid synovitis. FKN expression was examined by real‐time polymerase chain reaction and immunohistochemistry. CX3CR1 expression on peripheral blood T cells was analyzed by flow cytometry. T cell activation was quantified by determining proliferative responses, interferon‐γ (IFNγ) secretion, and granule release. Fibroblast‐like synoviocyte (FLS)/T cell adhesion was measured by the retention of 5‐carboxyfluorescein diacetate succinimidyl ester–labeled T cells on FLS monolayers.FKN was expressed on cultured synovial fibroblasts and hyperplastic synoviocytes in the rheumatoid tissue. Among CD4+ T cells, only senescent CD28− T cells were positive for CX3CR1 (P < 0.001). Such CD4+,CD28−,CX3CR1+ T cells strongly adhered to FLS, with soluble FKN blocking the interaction. FKN expressed on FLS costimulated T cell–activating signals and amplified proliferation, IFNγ production, and expulsion of cytoplasmic granules.Senescent CD4+ T cells that accumulate in rheumatoid arthritis aberrantly express CX3CR1. FKN, which is membrane‐anchored on synoviocytes, enhances CD4+ T cell adhesion, provides survival signals, and costimulates the production of proinflammatory cytokines as well as the release of granules. By virtue of their altered receptor profile, senescent CD4+ T cells receive strong stimulatory signals from nonprofessional antigen‐presenting cells in the synovial microenvironment. [ABSTRACT FROM AUTHOR]

Lupus nephritis is characterized by immune complex deposition and inflammatory cell infiltration into the renal glomeruli. Local generation of chemokines and the presence of chemokine receptors on the infiltrating cells may be involved in this process. Fractalkine (Fkn)/CX3CL1 and its receptor, CX3CR1, form one such chemokine system. We therefore undertook this study to investigate whether Fkn antagonist inhibits the initiation and progression of lupus nephritis in MRL/lpr mice. NH2‐ terminally truncated Fkn/CX3CL1 analogs were transfected into a nonmetastatic fibroblastoid cell line, MRL/N‐1, and injected subcutaneously into MRL/lpr mice.Fkn analogs truncated by ≥4 amino acid residues from the N‐ terminus failed to induce chemotaxis and calcium influx by CX3CR1‐expressing cells. Of these, the most potent antagonist (Fkn‐AT) lacked the 4 N‐ terminal amino acid residues. Fkn expression in the glomerulus was significantly increased in 12‐ week‐ old MRL/lpr mice. Expression was localized predominantly in the glomerular endothelial cells, but was occasionally observed in the mesangial cells and, to a lesser extent, in the interstitial microvasculature. Inoculation of MRL/lpr mice with Fkn‐AT before the onset or during the early stages of lupus nephritis significantly reduced glomerular hypercellularity, glomerulosclerosis, crescent formation, and vasculitis compared with control mice. This seemed to be due to a marked reduction in macrophage accumulation. In contrast, Fkn antagonist did not affect pneumonitis, sialadenitis, lymphadenopathy, or splenomegaly. We prepared a novel potent Fkn antagonist and demonstrated its ability to delay the initiation and ameliorate the progression of lupus nephritis. This agent may therefore provide a new therapeutic approach to lupus nephritis. [ABSTRACT FROM AUTHOR]

This study aimed to establish an exposure method that can induce homogeneous lesions with minimal inter-individual variability. The distribution of lesions induced by bleomycin (BLM) administration was also analyzed. C57BL mice were intrabronchially administered 20 µL of BLM (3 mg/mL) using a bronchoscope in the left or right bronchus. The mice were sacrificed 14 days after administration, and their lungs were evaluated histopathologically. BLM-induced inflammatory lesions were widely observed in the lungs. In the left bronchus-treated group, lesions were uniformly observed throughout the lobe, and no individual differences were noted. Meanwhile, in the right bronchus-treated group, individual differences in the distribution of the pulmonary lesions were observed. The distribution of lesions differed among the four lobes of the right lung owing to their anatomical features. Administration into the left bronchus is recommended for highly homogeneous lung exposure and for establishing models that contribute to highly accurate toxicity and efficacy evaluations. [ABSTRACT FROM AUTHOR]

Short-term dextran sodium sulfate (DSS) treatment has been shown to notably accelerate colorectal tumor development in rats initiated with 1,2-dimethylhydrazine (DMH). In the present study, to clarify mechanisms underlying the DSS influence, time-course studies of histopathological and immunohistochemical characteristics and β-catenin gene mutations in colorectal mucosa in early stages of this model were conducted. F344 males were given three subcutaneous injections of DMH (40 mg/kg body wt) within a week, followed by free access to drinking water containing 1% DSS for a week. At weeks 1, 4, 6 and 8 after the DSS treatment, rats were euthanized and colorectal samples were collected. At week 1, the colorectal mucosa demonstrated extensive erosion along with significant inflammatory cell infiltration and neighboring reactive hyperplasia. By week 4, the mucosal damage was repaired and regenerative mucosa, partly characterized by Paneth cell metaplasia and altered subcellular localization of β-catenin, was apparent. Areas with Paneth cells/β-catenin accumulation were significantly more likely to be accompanied by interstitial inflammation and 17 of 24 dysplastic foci were found in regenerative mucosa with Paneth cells. Furthermore, adenomas/carcinomas frequently featured various degrees of Paneth cell differentiation. Point mutations mainly in codons 34 and 41 of β-catenin gene were detected in 6 of 27 samples of regenerative mucosa with Paneth cells and four of nine dysplastic foci/adenomas/carcinomas. These findings indicate that inflammation-associated regenerative mucosa with Paneth cell metaplasia and alteration in the APC/β-catenin/Tcf signal transduction pathway are possibly involved in the acceleration of colorectal carcinogenesis in this DMH–DSS rat model. [ABSTRACT FROM AUTHOR]

Methylthioacetic acid (MTA) is an acid-hydrolyzed derivative of a natural aroma compound, methylthioacetic acid ethyl ester isolated from Cucumis melo var. conomon (Katsura-uri, Japanese Picking Melon), and induces a villiform-like structure dome in RCM-1 human colorectal cancer cell culture. Thus far, the physiological and molecular properties of MTA-mediated dome formation remain unknown. Herein, MTA (not more than 2 mM) was demonstrated to differentiate the unorganized cell mass into the dome in RCM-1 cell culture by disclosing the correlation between dome formation and several intestinal differentiation markers such as alkaline phosphatase activity and the protein levels of dipeptidyl peptidase 4, villin, and Krüppel-like factor 4. Dome formation in RCM-1 cell culture was additively enhanced by the simultaneous administration of MTA and butyric acid (BA), suggesting that MTA directs the differentiation of RCM-1 cells, potentially through the same or similar pathway(s) shared with BA. Notably, a high dose of MTA (2 mM or more) elevated several apoptosis markers, such as DNA fragmentation, caspase- 3/7 activity, and cleavage of poly(ADP-ribose) polymerase. Altogether, in addition to RCM-1 cell differentiation, MTA triggers apoptosis. These results indicate that MTA is a potential anticarcinogenic agent applicable in differentiation therapy and traditional chemotherapy against colorectal cancers. [ABSTRACT FROM AUTHOR]

Recently, we introduced an organoid-based chemical carcinogenesis model using mouse normal tissue-derived organoids. In the present review article, the histopathological and immunohistochemical characteristics of mouse normal tissue-derived organoids and tumors derived from these organoids after their in vitro treatment with genotoxic carcinogens and injection into nude mouse are reviewed. In organoids treated in vitro with genotoxic carcinogens, we confirmed macroscopic tumorigenicity and histopathological findings, including neoplastic characteristics, such as multilayered epithelia and/or invasion of epithelia into the surrounding interstitium. In contrast glandular/cystic structures with monolayered epithelia were clearly demarcated from the surrounding Matrigel/interstitium in the untreated control groups. In addition to macroscopic tumorigenicity, these microscopic epithelial changes, which are characteristic of the early stages of carcinogenesis, are included in the requirements for carcinogenicity-positive judgement of the organoidbased carcinogenesis model. Immunohistochemistry of cytokeratins (CKs), used to determine the origin of epithelia and distribution of extraductal invasive lesions, or oncogenic kinases, which reflect molecular activation in epithelia following chemical treatment, is helpful for accurate diagnosis and molecular evaluation in the early stages of carcinogenesis. This information improves our biological understanding of organoid-based chemical carcinogenesis models. [ABSTRACT FROM AUTHOR]

Because histopathological findings are often conclusive indicators of the toxicities of chemicals, standardization of nomenclature and construction of a thesaurus for histopathological findings are important for the comparative evaluation of histopathological data from repeated-dose toxicity studies (RTS). However, terms for histopathological findings have not been standardized and different technical terms are used to indicate almost the same thing in RTS. The present study was conducted to construct an easy-to-use thesaurus for histopathological findings in order to facilitate hazard assessments of untested chemicals by the category approach using knowledge of the toxicity of analogue chemicals. We used reports of 28-day RTS, conducted on rats by gavage, which were posted on the websites of the National Institute of Health Sciences (NIHS) and the National Institute of Technology and Evaluation (NITE). The histopathological data were from 156 reports on RTS conducted by 13 institutions in Japan. As a result of this study, major parts of the thesaurus were devoted to the findings in the liver, kidney, stomach, adrenal, thyroid and testis; the first three organs are known to be the main targets of chemicals. We also decided that findings such as swelling and enlargement of hepatocytes should be categorized as synonyms for terms meaning hypertrophy. Our thesaurus will be helpful in assessing or screening new untested chemicals by the category approach using knowledge of the toxicities of analogues of the new chemical. The RTS database with this thesaurus will be made publically available in 2012. [ABSTRACT FROM AUTHOR]

Transplantation outcomes are affected by the increase in rejection associated with ischemia reperfusion injury (IRI). Fractalkine (FKN), a chemokine for recruitment of CX3CR1+ leukocytes, contributes to the pathogenesis of various inflammatory diseases. Herein, we evaluated the importance of the FKN-CX3CR1 axis during IRIrelated rejections using a mouse heterotopic heart transplantation model. FKN expression and graft survival was compared between wild-type C57BL/6 recipients transplanted with BALB/c hearts preserved for 8 (WT-IRI) and 0.5 h (WT-control) at 4°C. Graft survival of WTIRI was shorter than that of WT-control. FKN was expressed on the vascular endothelium in WT-IRI allografts, but minimally in WT-control. The role of the FKN-CX3CR1 axis in IRIrelated rejection was directly investigated using the transplant model with CX3CR1-deficient recipients (CX3CR1 KO-IRI) or treatment with anti-mouse FKN monoclonal antibodies. Graft survival of CX3CR1 KO-IRI was longer than that of WT-IRI; antibody treatment prolonged graft survival. The contribution of CX3CR1+ monocytes to IRI-related rejection was evaluated by adoptive transfer to CX3CR1 KO-IRI. Adoptive transfer of CX3CR1+ monocytes attenuated the effect of prolonged graft survival in CX3CR1 KO-IRI. Overall, the FKN-CX3CR1 axis plays a major role during IRI-related rejection; its blockade has the potential to improve the outcomes of deceased donor transplantation. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the safety and efficacy of E6011, a novel humanized anti-fractalkine monoclonal antibody, in patients with active rheumatoid arthritis (RA) with an inadequate response to biological disease-modifying antirheumatic drugs (DMARDs). Methods: Active RA patients inadequately responding to biological DMARDs were randomly assigned to placebo or E6011 400-mg group at a 1:1 ratio, and administered E6011 at weeks 0, 1, 2, and subsequently every 2 weeks. Primary endpoint was American College of Rheumatology (ACR)20 response at week 12. Results: Of 64, 33 received placebo, 31 received E6011 400-mg. The ACR20 response rate at week 12 (non-responder imputation) was 27.3% and 22.6% in the placebo and E6011 groups, respectively. ACR50, ACR70 response rates at week 12 were 3.0%, 0% in the placebo and 9.7%, 3.2% in the E6011 group. Exploratory PK exposure analysis revealed that the effect of E6011 tended to be clearer in patients with higher serum trough E6011 concentration. E6011 was well tolerated with no notable safety concerns. Conclusions: E6011 400-mg was well tolerated but had no clear efficacy at week 12 in RA patients with inadequate response to biologics. Further investigations are warranted to determine the optimal clinical dose and evaluation period for E6011. [ABSTRACT FROM AUTHOR]

Osteopontin (OPN) is a secreted phosphoglycoprotein, and is a transcriptional target of aberrant Wnt signaling. OPN is upregulated in human colon cancers, and is suggested to enhance cancer progression. In this study, the effect of deficiency of OPN on intestinal tumor development in Apc-deficient Min mice was investigated. At 16 weeks of age, the number of small intestinal polyps in Min/OPN(+/−) and Min/OPN(−/−) mice was lower than that of Min/OPN(+/+) mice. Colorectal tumor incidences and multiplicities in Min/OPN(+/−) and Min/OPN(−/−) mice were significantly lower than those in Min/OPN(+/+) mice, being 48% and 0.6 ± 0.8, 50% and 0.8 ± 0.9 vs. 80% and 1.6 ± 1.7, respectively. OPN expression in colorectal tumors was strongly upregulated in Min/OPN(+/+) compared to adjacent non-tumor parts, but was decreased in Min/OPN(+/−) and not detected in Min/OPN(−/−). Targets of OPN, matrix metalloproteinases (MMPs)-3, -9, and -13 were lowered by OPN deficiency. Macrophage marker F4/80 in colorectal tumors was also lowered by OPN deficiency. MMP-9 expression was observed in tumor cells and tumor-infiltrating neutrophils. These results indicate that induction of OPN by aberrant Wnt signaling could enhance colorectal tumor development in part by upregulation of MMP-3, -9, and -13 and infiltration of macrophage and neutrophils. Suppression of OPN expression could contribute to tumor prevention, but complete deficiency of OPN may cause some adverse effects. [ABSTRACT FROM AUTHOR]