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Astatine and bismuth sorption on several ion exchange resins from nitric acid media has been studied. This work covers commercially available resins Dowex 50 × 4, MP thiol, Dowex 1 × 8, and TEVA. One of the main advantages of using ion exchangers for astatine separation and purification is the absence of any organic media in the effluent in comparison with extraction chromatography resins. The behavior of the above-mentioned metals was investigated in up to 4 M HNO3 solutions. The determined distribution coefficients are greater than 1 for all the resins studied, reaching 104 for MP thiol and TEVA resins. The interaction of nitric acid with an anion exchanger in Cl-form results in an exchange reaction, where AtO+ chloro complexes can form. To understand the astatine behavior under these conditions, stability constants of AtOCl and AtOCl2− complexes have been reevaluated and discrepancy in the literature values has been eliminated. For each resin a thermodynamic model has been developed to suggest a possible mechanism of astatine sorption. Literature and new experimental data on bismuth sorption by studying resins in nitric acid media have been reviewed and a mathematical model to describe its behavior has been suggested. A ratio of corresponding fit functions of At and Bi assigned to the same resin and acidity has been used to estimate the separation factors of these elements. [ABSTRACT FROM AUTHOR]

Objective(s): This study was aimed at investigating immune activations of the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model in colonic mucosa by immunohistochemical and Western blot methods. Materials and Methods: For this purpose, 16 female Wistar albino rats were divided into two r andom groups of control (n=8) and colitis (n=8). The experimental colitis model was induced by intracolonic administration of TNBS (25 mg/rat). Control animals received only rectal saline for the same time. The animals were sacrificed on the 15th day after TNBS administration, and colon tissue was removed and examined morphologically. Colon samples were stained immunohistochemically with anti-CD3, anti-CD4, anti-CD5, anti-CD8, anti-CD11b, anti-CD45, anti-TNF-a, anti-IL-17, anti-IL-22 and anti-IL-23 antibodies. Additionally, the colonic tissue IL-17 and IL-22 expressions were examined by the Western blot method. Results: In the experimental results, it was determined that there was a significant decrease in body weight and an increase in colon weight in the colitis group when comparing initial experiments. The colon tissue ulcerations, inflammation, crypt loss and Goblet cell loss were observed in the colitis group in microscopic examinations. The immunohistochemical positive cell numbers significantly increased in the colitis group. The immunoreactive lymphocytes in the propria, intracryptal and submucosal layers were found to be increased in the colitis group of rats. In addition, IL-17 and IL-23 expressions were increased in colitis colon mucosa found by Western blot analysis. Conclusion: The Th17/IL-23 pathway and IL-22 serve important roles in the pathogenesis of ulcerative colitis, and will be further examined by study. [ABSTRACT FROM AUTHOR]

Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression. [ABSTRACT FROM AUTHOR]

A promising therapeutic approach to diminish pathological inflammation is to inhibit the increased production and/or biological activity of proinflammatory cytokines (e.g., TNF-α, IL-6). The production of proinflammatory cytokines is controlled at the gene level by the activity of transcription factors, such as NF-κB. Phosphatidylinositol 3-kinase (P13K), a lipid kinase, is known to induce the activation of NF-κB. Given this, we hypothesized that inhibitors:of P13K activation would demonstrate anti-inflammatory potential.' Accordingly, we studied the effects of a preferential p110α/γ P13K inhibitor (compound 8C; PIK-75) in inflammation-based assays. Mechanism-based assays utilizing human cells revealed that PIK-75-mediated inhibition of P13K activation is associated with dramatic suppression of downstream signaling events, including AKT phosphorylation; IKK activation, and NF-κB transcription. Cell-based assays revealed that PIK-75 potently and dose dependently inhibits in vitro and in vivo production of TNF-α and IL-6, diminishes the induced expression of human endothelial cell adhesion molecules (E-selectin, ICAM-1, and VCAM-1), and blocks human monocyte-endothelial cell adhesion. Most importantly, PIK-75, when administered orally in a therapeutic regimen, significantly suppresses the macroscopic and histological abnormalities associated with dextran sulfate sodium-induced murine colitis. The efficacy of PIK-75 in attenuating experimental inflammation is mediated, at least in part, due to the downregulation of pertinent inflammatory mediators in the colon. Collectively, these results provide first evidence that PIK-75 possesses anti-inflammatory potential. Given that PIK-75 is known to exhibit anti-cancer activity, the findings from this study thus reinforce the cross-therapeutic functionality of potential drugs. [ABSTRACT FROM AUTHOR]

The active stage of ulcerative colitis (UC) involves transmigration of polymorphonuclear (PMN) cells to colonic epithelia. The angiopoietin (Ang) pathway plays a role as the regulator of PMN transmigration. To clarify the role of the Ang/Tie pathway in the activation of UC, especially in cypt abscess formation, 67 tissue samples were obtained from patients with UC and ten controls without UC for immunohistochemical analysis for the expression of Ang-1, -2, or Tie-2. The epithelia of crypt abscess was strongly positive for Ang-1 and -2 for all 57 samples derived from patients with active UC, though the colorectal epithelium without crypt abscess showed minimal expression of Ang-1, -2, and Tie-2. Numerous transepithelial migrating PMN cells in crypt abscesses also expressed Tie-2. The specimens of UC patients in remission showed significantly less immunoreactivity for Ang-1, -2, or Tie-2. These findings suggest that the Ang/Tie pathway may play a role in the progression of UC. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is a lifelong inflammatory disorder with relapsing–remission cycles, which is currently diagnosed by clinical symptoms and signs, along with laboratory and imaging findings. However, such clinical findings are not parallel to the disease activity of IBD and are difficult to use in treatment monitoring. Therefore, non-invasive quantitative imaging tools are required for the multiple follow-up exams of IBD patients in order to monitor the disease activity and determine treatment regimens. In this study, we evaluated a dual P- and E-selectin-targeted microbubble (MBSelectin) in an interleukin-2 receptor α deficient (IL-2Rα−/−) spontaneous chronic IBD mouse model for assessing long-term anti-inflammatory effects with ultrasound molecular imaging (USMI). We used IL-2Rα−/− (male and female on a C57BL/6 genetic background; n = 39) and C57BL/6 wild-type (negative control; n = 6) mice for the study. USMI of the proximal, middle, and distal colon was performed with MBSelectin using a small animal scanner (Vevo 2100) up to six times in each IL-2Rα−/− mouse between 6–30 weeks of age. USMI signals were compared between IL-2Rα−/− vs. wild-type mice, and sexes in three colonic locations. Imaged colon segments were analyzed ex vivo for inflammatory changes on H&E-stained sections and for selectin expression by immunofluorescence staining. We successfully detected spontaneous chronic colitis in IL-2Rα−/− mice between 6–30 weeks (onset at 6–14 weeks) compared to wild-type mice. Both male and female IL-2Rα−/− mice were equally (p = 0.996) affected with the disease, and there was no significant (p > 0.05) difference in USMI signals of colitis between the proximal, middle, and distal colon. We observed the fluctuating USMI signals in IL-2Rα−/− mice between 6–30 weeks, which might suggest a resemblance of the remission-flare pattern of human IBD. The ex vivo H&E and immunostaining further confirmed the inflammatory changes, and the high expression of P- and E-selectin in the colon. The results of this study highlight the IL-2Rα−/− mice as a chronic colitis model and are suitable for the long-term assessment of treatment response using a dual P- and E-selectin-targeted USMI. [ABSTRACT FROM AUTHOR]

Coptisine (COP) is a bioactive isoquinoline alkaloid derived from Coptis Chinemsis Franch, which is traditionally applied for the management of colitis. However, the blood concentration of COP was extremely low, and its gut microbiota-mediated metabolites were thought to contribute to its prominent bioactivities. To comparatively elucidate the protective effect and underlying mechanism of COP and its novel gut microbiota metabolite (8-oxocoptisine, OCOP) against colitis, we used dextran sulfate sodium (DSS) to induce colitis in mice. Clinical symptoms, microscopic alternation, immune-inflammatory parameters for colitis were estimated. The results indicated that OCOP dramatically ameliorated disease activity index (DAI), the shortening of colon length and colonic histopathological deteriorations. OCOP treatment also suppressed the mRNA expression and release of inflammatory mediators (TGF-β, TNF-α, IL-6, IL-18, IL-1β and IFN-γ) and elevated the transcriptional and translational levels of anti-inflammatory cytokine (IL-10) as well as the mRNA expression levels of adhesion molecules (ICAM-1 and VCAM-1). Besides, the activation of NF-κB pathway and NLRP3 inflammasome was markedly inhibited by OCOP. Furthermore, OCOP displayed superior anti-colitis effect to COP, and was similar to MSZ with much smaller dosage. Taken together, the protective effect of OCOP against DSS-induced colitis might be intimately related to inhibition of NF-κB pathway and NLRP3 inflammasome. And the findings indicated that OCOP might have greater potential than COP to be further exploited as a promising candidate in the treatment of colitis. [ABSTRACT FROM AUTHOR]