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Sample records for enhanced mucosal reactions

  1. Enhanced mucosal reactions in AIDS patients receiving oropharyngeal irradiation

    SciTech Connect

    Watkins, E.B.; Findlay, P.; Gelmann, E.; Lane, H.C.; Zabell, A.

    1987-09-01

    The oropharynx and hypopharynx are common sites of involvement in AIDS patients with mucocutaneous Kaposi's sarcoma. The radiotherapist is often asked to intervene with these patients due to problems with pain, difficulty in swallowing, or impending airway obstruction. We have noted an unexpected decrease in normal tissue tolerance of the oropharyngeal mucosa to irradiation in AIDS patients treated in our department. Data on 12 patients with AIDS and Kaposi's sarcoma receiving oropharyngeal irradiation are presented here. Doses ranged from 1000 cGy to 1800 cGy delivered in 150-300 cGy fractions. Seven of eight patients receiving doses of 1200 cGy or more developed some degree of mucositis, four of these developed mucositis severe enough to require termination of treatment. All patients in this study received some form of systemic therapy during the course of their disease, but no influence on mucosal response to irradiation was noted. Four patients received total body skin electron treatments, but no effect on degree of mucositis was seen. Presence or absence of oral candidiasis was not an obvious factor in the radiation response of the oral mucosa in these patients. T4 counts were done on 9 of the 12 patients. Although the timing of the T4 counts was quite variable, no correlation with immune status and degree of mucositis was found. The degree of mucositis seen in these patients occurred at doses much lower than expected based on normal tissue tolerances seen in other patient populations receiving head and neck irradiations. We believe that the ability of the oral mucosa to repair radiation damage is somehow altered in patients with AIDS.

  2. Enhancement of gastric mucosal blood flow with sulglycotide.

    PubMed

    Guslandi, M; Sorghi, M; Tittobello, A

    1994-01-01

    Twelve patients with dyspepsia whose gastric abnormalities ranged from diffuse reddening of the mucosa to multiple erosions were treated for 4 weeks with oral sulglycotide, a sulphated glycopeptide with known gastroprotective and ulcer-healing properties. Before and after treatment, gastric mucosal blood flow was assessed by means of laser Doppler flowmetry. A significant (P < 0.01) increase in mucosal perfusion was observed after sulglycotide treatment, suggesting that enhancement of mucosal blood flow may contribute to the therapeutic properties of the drug.

  3. Cinnamon-induced Oral Mucosal Contact Reaction

    PubMed Central

    Vivas, Ana P. M; Migliari, Dante A

    2015-01-01

    Contact stomatitis associated with consumption of cinnamon flavoring agents is a relatively uncommon disorder. Of relevance, both clinical features and the histopathologic findings of this condition are nonspecific, and, more importantly, may resemble some other inflammatory oral mucosa disorders, eventually making diagnosis difficult. Usually a patient exhibits a combination of white and erythematous patches of abrupt onset, accompanied by a burning sensation. To shed some light on this subject, a case of a 64-year-old woman with hypersensitivity contact reaction on the oral mucosa due to cinnamon mints is presented, with emphasis on differential diagnosis and the process for confirmation of the diagnosis. The treatment consists of discontinuing the use of cinnamon products. Clinicians will be able to recognize this disorder following a careful clinical examination and detailed history. This recognition is important in order to avoid invasive and expensive diagnostic procedures. PMID:26312097

  4. Enhancing the buccal mucosal uptake and retention of triamcinolone acetonide.

    PubMed

    Nicolazzo, Joseph A; Reed, Barry L; Finnin, Barrie C

    2005-07-20

    In this study, the buccal mucosal uptake and retention of triamcinolone acetonide (TAC) were assessed in the presence of the skin penetration enhancer, Azone (AZ). Porcine buccal mucosa was excised, mounted in modified Ussing chambers, and pretreated with ethanolic solutions of AZ. After 2 h, the rate of TAC disappearance from the donor chamber and TAC appearance in the receptor chamber was monitored, and the mucosal retention of TAC was determined at the completion of the experiment. The permeability and mucosal uptake of TAC was also determined using the TAC-containing proprietary product, Kenalog in Orabase (KO), in the presence and absence of AZ. Pretreatment of the buccal mucosa with AZ increased the TAC disappearance permeability coefficient from 4.78+/-0.31x10(-5) cm/s to 7.12+/-0.53x10(-5) cm/s. While the TAC appearance permeability coefficient was also enhanced 3.8-fold, a 4.4-fold increase in the tissue concentration of TAC was observed. Incorporation of AZ into KO did not result in an enhanced tissue concentration of TAC, however, when the tissue was pretreated with AZ, significantly higher amounts of TAC accumulated in the tissue. Pretreatment of the buccal mucosa with AZ results in increased tissue concentrations of TAC, which may be of clinical benefit in the treatment of oral mucosal inflammatory conditions.

  5. Enhancing the buccal mucosal delivery of peptide and protein therapeutics.

    PubMed

    Caon, Thiago; Jin, Liang; Simões, Cláudia M O; Norton, Raymond S; Nicolazzo, Joseph A

    2015-01-01

    With continuing advances in biotechnology and genetic engineering, there has been a dramatic increase in the availability of new biomacromolecules, such as peptides and proteins that have the potential to ameliorate the symptoms of many poorly-treated diseases. Although most of these macromolecular therapeutics exhibit high potency, their large molecular mass, susceptibility to enzymatic degradation, immunogenicity and tendency to undergo aggregation, adsorption, and denaturation have limited their ability to be administered via the traditional oral route. As a result, alternative noninvasive routes have been investigated for the systemic delivery of these macromolecules, one of which is the buccal mucosa. The buccal mucosa offers a number of advantages over the oral route, making it attractive for the delivery of peptides and proteins. However, the buccal mucosa still exhibits some permeability-limiting properties, and therefore various methods have been explored to enhance the delivery of macromolecules via this route, including the use of chemical penetration enhancers, physical methods, particulate systems and mucoadhesive formulations. The incorporation of anti-aggregating agents in buccal formulations also appears to show promise in other mucosal delivery systems, but has not yet been considered for buccal mucosal drug delivery. This review provides an update on recent approaches that have shown promise in enhancing the buccal mucosal transport of macromolecules, with a major focus on proteins and peptides.

  6. Enhancing chemical reactions

    DOEpatents

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  7. Smoking during radiotherapy for head and neck cancer and acute mucosal reaction

    PubMed Central

    Szeszko, Beata; Osowiecka, Karolina; Rucińska, Monika; Wasilewska-Teśluk, Ewa; Gliński, Krzysztof; Kępka, Lucyna

    2015-01-01

    Aim We compared the incidence of RTOG/EORTC grade III and higher acute mucositis in patients with head and neck cancer who continued to smoke during radiotherapy with those who quit smoking. Background There are conflicting data on the relationship between smoking during radiotherapy and the severity of acute mucosal reaction. More studies dealing with this issue are needed. Materials and methods Among 136 patients receiving curative radio(chemo)therapy, 37 (27%) declared that they had not quit smoking during radiotherapy. The intensity of mucositis was scored daily by a nurse and weekly by a physician using the RTOG/EORTC scale. The main end-point of the study was the highest observed RTOG/EORTC grade of mucositis. Results Patients who smoked during radiotherapy (smokers) were younger than their counterparts who quit smoking (non-smokers), p = 0.06. There were no other differences in the baseline characteristics between smokers and non-smokers. Grade III/IV acute mucositis was observed in 43.5% of all patients. The percentage of patients with grade III/IV acute mucositis was similar in smokers and non-smokers (46% vs. 42%, p = 0.71). Nine patients (smokers [13.5%]; non-smokers [4%], p = 0.05) required prolonged hospitalization to heal mucositis. Conclusions In the whole group, smoking during radiotherapy was not related to acute mucosal toxicity evaluated as the rate of the highest observed grade of mucositis. PMID:26109918

  8. Use of inactivated E.Coli enterotoxins to enhance respiratory mucosal adjuvanticity during vaccination in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to augment responses to respiratory vaccines in swine, various adjuvants were intranasally co-administered with an antigen to pigs. Detoxified E. coli enterotoxins LTK63 and LTR72 enhanced mucosal and systemic immunity to the model peptide, exhibiting their efficacy as mucosal adjuvants for...

  9. Mucosal polymerase chain reaction for diagnosing Helicobacter pylori infection in patients with bleeding peptic ulcers

    PubMed Central

    Lin, Hwai-Jeng; Lo, Wen-Ching; Perng, Chin-Lin; Tseng, Guan-Ying; Li, Anna Fen-Yau; Ou, Yueh-Hsing

    2005-01-01

    AIM: Helicobacter pylori (H pylori) has been linked to chronic gastritis, peptic ulcers, gastric cancer and MALT-lymphoma. Conventional invasive tests are less sensitive than non-invasive tests in diagnosing H pylori infection in patients with bleeding peptic ulcers. Polymerase chain reaction is a sensitive and accurate method for diagnosing H pylori infection. The aim of this study was to evaluate the diagnostic role of mucosal polymerase chain reaction for H pylori infection in patients with bleeding peptic ulcers. METHODS: In patients with bleeding, non-bleeding peptic ulcers and chronic gastritis, we checked rapid urease test, histology, bacterial culture and mucosal polymerase chain reaction for detecting H pylori infection. Positive H pylori infection was defined as positive culture or both a positive histology and a positive rapid urease test. For mucosal polymerase chain reaction of H pylori, we checked vacA (s1a, s1b, s1c, s2, m1, m1T, m2), iceA1, iceA2 and cag A. RESULTS: Between October 2000 and April 2002, 88 patients with bleeding peptic ulcers (males/females: 60/28, gastric ulcers/duodenal ulcers: 55/33), 81 patients with non-bleeding peptic ulcers (males/females: 54/27, gastric ulcers/duodenal ulcers: 45/36) and 37 patients with chronic gastritis (males/females: 24/13) were enrolled in this study. In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, 45 patients (51%), 71 patients (88%) and 20 patients (54%) respectively were found to have positive H pylori infection (P<0.001). In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, polymerase chain reaction for H pylori infection was positive in 54 patients (61%), 70 patients (86%) and 20 patients (54%) respectively (P<0.001). The sensitivity, positive predictive value and diagnostic accuracy of mucosal polymerase reaction for H pylori infection were significantly lower in patients with bleeding peptic ulcers (84%, 79% and 81

  10. Pathogenesis of Salmonellosis STUDIES OF FLUID SECRETION, MUCOSAL INVASION, AND MORPHOLOGIC REACTION IN THE RABBIT ILEUM

    PubMed Central

    Giannella, R. A.; Formal, S. B.; Dammin, G. J.; Collins, H.

    1973-01-01

    Strains of Salmonella typhimurium were studied in the ligated rabbit ileal loop model to gain insight into the mechanisms whereby bacteria which invade the gastrointestinal mucosa evoke fluid exsorption. The organisms employed differed in various biologic attributes including the ability to invade the ileal epithelium, multiply within the mucosa, elicit an acute inflammatory reaction, and disseminate across the intestinal wall. Some strains provoked small intestinal fluid exsorption although these did not elaborate enterotoxin. Only those strains which invaded the mucosa were accompanied by either mucosal inflammation or fluid exsorption. Noninvasive strains produced neither histologic abnormalities nor fluid secretion. While strains which invaded the mucosa caused an acute inflammatory reaction, not all such strains evoked fluid secretion. Furthermore, there was no correlation in ability of invasive organisms to evoke fluid secretion or in the intensity of mucosal inflammation, number of intramucosal salmonellae, or in ability to disseminate from the rabbit ileum. These observations suggest that, as is the case in shigellosis, mucosal invasion may be a necessary factor for the intestinal fluid loss in salmonellosis. A bacterial property or factor, in addition to invasion of the gastrointestinal mucosa, seems to be responsible for fluid exsorptin. However, it is unlikely that a salmonella enterotoxin comparable to that elaborated by Vibrio cholerae, toxigenic Escherichia coli, or Shigella dysenteriae 1 is related to fluid secretion in salmonellosis. Images PMID:4630603

  11. IL-33 targeting attenuates intestinal mucositis and enhances effective tumor chemotherapy in mice.

    PubMed

    Guabiraba, R; Besnard, A G; Menezes, G B; Secher, T; Jabir, M S; Amaral, S S; Braun, H; Lima-Junior, R C P; Ribeiro, R A; Cunha, F Q; Teixeira, M M; Beyaert, R; Graham, G J; Liew, F Y

    2014-09-01

    Intestinal damage and severe diarrhea are serious side effects of cancer chemotherapy and constrain the usage of most such therapies. Here we show that interleukin-33 (IL-33) mediates the severe intestinal mucositis in mice treated with irinotecan (CPT-11), a commonly used cancer chemotherapeutic agent. Systemic CPT-11 administration led to severe mucosal damage, diarrhea, and body weight loss concomitant with the induction of IL-33 in the small intestine (SI). This mucositis was markedly reduced in mice deficient in the IL-33R (ST2(-/-)). Moreover, recombinant IL-33 exacerbated the CPT-11-induced mucositis, whereas IL-33 blockade with anti-IL-33 antibody or soluble ST2 markedly attenuated the disease. CPT-11 treatment increased neutrophil accumulation in the SI and adhesion to mesenteric veins. Supernatants from SI explants treated with CPT-11 enhanced transmigration of neutrophils in vitro in an IL-33-, CXCL1/2-, and CXCR2-dependent manner. Importantly, IL-33 blockade reduced mucositis and enabled prolonged CPT-11 treatment of ectopic CT26 colon carcinoma, leading to a beneficial outcome of the chemotherapy. These results suggest that inhibition of the IL-33/ST2 pathway may represent a novel approach to limit mucositis and thus improve the effectiveness of chemotherapy.

  12. Image-enhanced bronchoscopic evaluation of bronchial mucosal microvasculature in COPD

    PubMed Central

    Fathy, Eman Mahmoud; Shafiek, Hanaa; Morsi, Tamer S; El Sabaa, Bassma; Elnekidy, Abdelaziz; Elhoffy, Mohamed; Atta, Mohamed Samy

    2016-01-01

    Background Bronchial vascular remodeling is an underresearched component of airway remodeling in COPD. Image-enhanced bronchoscopy may offer a less invasive method for studying bronchial microvasculature in COPD. Objectives To evaluate endobronchial mucosal vasculature and changes in COPD by image-enhanced i-scan3 bronchoscopy and correlate them pathologically by analyzing bronchial mucosal biopsies. Methods This case–control study analyzed 29 COPD patients (41.4% Global initiative for chronic Obstructive Lung Disease B [GOLD B] and 58.6% GOLD D) and ten healthy controls admitted at Alexandria Main University Hospital, Egypt. Combined high-definition white light bronchoscopy (HD WLB) with i-scan3 was used to evaluate endobronchial mucosal microvasculature. The vascularity was graded according to the level of mucosal red discoloration (ie, endobronchial erythema) from decreased discoloration to normal, mild, moderate, and severe increased red discoloration (G−1, G0, G+1, G+2, and G+3, respectively) and scored by three bronchoscopists independently. Bronchial mucosal biopsies were taken for microvascular density counting using anti-CD34 antibody as angiogenesis marker. Results Different grades of endobronchial erythema were observed across/within COPD patients using combined HD WLB + i-scan3, with significant agreement among scorers (P=0.031; median score of G+1 [G−1–G+2]) being higher in GOLD D (P=0.001). Endobronchial erythema significantly correlated with COPD duration, exacerbation frequency, and body mass index (P<0.05). Angiogenesis was significantly decreased among COPD patients versus controls (10.6 [8–13.3] vs 14 [11–17.1]; P=0.02). Mucosal surface changes (including edema, atrophy, and nodules) were better visualized by the combined HD WLB + i-scan3 rather than HD WLB alone. Conclusion Combined HD WLB + i-scan3 seems to be valuable in evaluating mucosal microvasculature and surface changes in COPD, which may represent vasodilatation rather than

  13. Freeze Enhanced Halate Halide Reactions

    NASA Astrophysics Data System (ADS)

    Newberg, J. T.; Weaver, K.; Broderick, A.

    2014-12-01

    Relatively little is known about halate ion species (XO3-; X = I, Br, Cl) in atmospheric condensed phases. It was initial thought that iodate was a terminal stable species upon iodide oxidation. However, it is becoming increasingly recognized that reactions involving iodate can lead to reactive iodine, and this chemistry is accelerated under acidic conditions. The environmental concentrations and chemistry of bromate and chlorate are largely unexplored in environmental ices. We present results from a series of aqueous phase halate ion reactions with halides under acidic conditions, showing that the kinetics are strongly enhanced upon freezing. The products of these reactions are reactive halogens, which have important implications to marine boundary layer chemistry.

  14. Enhancement of Mucosal Immunization with Virus-Like Particles of Simian Immunodeficiency Virus

    PubMed Central

    Kang, Sang-Moo; Compans, Richard W.

    2003-01-01

    Cholera toxin (CT) is the most potent known mucosal adjuvant, but its toxicity precludes its use in humans. Here, in an attempt to develop safe and effective mucosal adjuvants, we compared immune responses to simian immunodeficiency virus (SIV) virus-like particles (VLPs) after intranasal coimmunization with RANTES, CpG oligodeoxynucleotides (ODN), or CT. Antibody analysis demonstrated that RANTES and CpG ODN had capacities for mucosal adjuvanticity, i.e., for enhancing serum and vaginal antibodies specific to SIV Env, similar to those for CT. RANTES and CpG ODN skewed serum antibodies predominantly to the immunoglobulin G2a isotype. Most importantly, RANTES and CpG ODN were more effective than CT in increasing neutralizing titers of both serum and vaginal antibodies. After intranasal coadministration with VLPs, RANTES or CpG ODN also induced increased levels of gamma interferon (IFN-γ)-producing lymphocyte and cytotoxic T-lymphocyte activities in both spleen and lymph nodes but did not increase the levels of interleukin-4-producing lymphocytes. The results suggest that RANTES and CpG ODN enhance immune responses in a T-helper-cell-type-1 (Th1)-oriented manner and that they can be used as effective mucosal adjuvants for enhancing both humoral and cellular immune responses in the context of VLPs, which are particulate antigens. PMID:12610137

  15. Separate effects of irradiation and of graft-versus-host reaction on rat mucosal mast cells.

    PubMed Central

    Cummins, A G; Munro, G H; Huntley, J F; Miller, H R; Ferguson, A

    1989-01-01

    T cell mediated immune responses in the gut can produce enteropathy and malabsorption. We have investigated the relevance of mucosal mast cells (MMC) to the mechanisms of this enteropathy by using graft-versus-host reaction (GvHR) in the rat as a model of mucosal delayed type hypersensitivity. Measurements of mucosal architecture, intraepithelial lymphocytes (IEL) and MMC counts were performed in control and experimental rats, and release of rat mast cell protease II (RMCPII) into the bloodstream was used as an index of MMC activation. In unirradiated rats, jejunal MMC count was increased on day 14 of the GvHR (mean 272/mm2 v 182 in controls, p less than 0.01), as was serum RMCPII (p less than 0.01). Irradiated rats (4.5 Gy, reconstituted with isogeneic spleen cells) had low counts of IEL and crypt hyperplasia seven to 14 days after irradiation. Irradiated rats with GvHR (induced by ip injection of parental strain spleen cells) and studied on days 7, 10 and 14, had significant enteropathy with longer crypts and higher CCPR than matched irradiated animals (p less than 0.05 on day 14 when compared with irradiation alone). Intraepithelial lymphocytes counts, however, reflected only the effect of radiation. Irradiation, with or without GvHR, led to the virtual disappearance of jejunal MMC, undetectable jejunal RMCPII and very low levels of RMCPII in serum (all p less than 0.01 when compared with unirradiated controls). These experiments show that there is a modest expansion in jejunal MMC in unirradiated rats with semiallogeneic GvHR, whereas irradiation, alone or associated with GvHR, profoundly depletes MMC for at least two weeks. The enteropathy of GvHR can evolve in the virtual absence of MMC. PMID:2707634

  16. Foxo1 inhibits diabetic mucosal wound healing but enhances healing of normoglycemic wounds.

    PubMed

    Xu, Fanxing; Othman, Badr; Lim, Jason; Batres, Angelika; Ponugoti, Bhaskar; Zhang, Chenying; Yi, Leah; Liu, Jian; Tian, Chen; Hameedaldeen, Alhassan; Alsadun, Sarah; Tarapore, Rohinton; Graves, Dana T

    2015-01-01

    Re-epithelialization is an important part in mucosal wound healing. Surprisingly little is known about the impact of diabetes on the molecular events of mucosal healing. We examined the role of the transcription factor forkhead box O1 (Foxo1) in oral wounds of diabetic and normoglycemic mice with keratinocyte-specific Foxo1 deletion. Diabetic mucosal wounds had significantly delayed healing with reduced cell migration and proliferation. Foxo1 deletion rescued the negative impact of diabetes on healing but had the opposite effect in normoglycemic mice. Diabetes in vivo and in high glucose conditions in vitro enhanced expression of chemokine (C-C motif) ligand 20 (CCL20) and interleukin-36γ (IL-36γ) in a Foxo1-dependent manner. High glucose-stimulated Foxo1 binding to CCL20 and IL-36γ promoters and CCL20 and IL-36γ significantly inhibited migration of these cells in high glucose conditions. In normal healing, Foxo1 was needed for transforming growth factor-β1 (TGF-β1) expression, and in standard glucose conditions, TGF-β1 rescued the negative effect of Foxo1 silencing on migration in vitro. We propose that Foxo1 under diabetic or high glucose conditions impairs healing by promoting high levels of CCL20 and IL-36γ expression but under normal conditions, enhances it by inducing TGF-β1. This finding provides mechanistic insight into how Foxo1 mediates the impact of diabetes on mucosal wound healing.

  17. Enhancement in gastric mucosal epidermal growth factor receptor expression by sulglycotide.

    PubMed

    Slomiany, B L; Piotrowski, J; Czajkowski, A; Murty, V L; Majka, J; Slomiany, A

    1994-05-01

    The effect of intragastric administration of sulglycotide, a cytoprotective sulfated glycopeptide, on the expression of gastric mucosal epidermal growth factor receptor was investigated. The experiments were conducted with groups of rats, one receiving twice daily for 5 consecutive days a dose of 200mg/kg sulglycotide, and the other only vehicle. Mucosal cell membranes were isolated from the stomachs at 16, 40 and 88h after the last dose, and used for EGF receptor assays. The binding assays revealed a marked increase in mucosal EGF receptor expression with sulglycotide. Compared to the controls, the sulglycotide-treated group showed a 4-fold increase in the EGF receptor expression at 16h after the last dose of sulglycotide, a 4.7-fold increase in the EGF receptor was observed by the 40h, and a 4.2-fold increase was still evident at 88h following the treatment. The results demonstrate that sulglycotide exhibits remarkable ability to enhance the gastric mucosal expression of EGF receptor.

  18. Enhancement in gastric mucosal EGF and PDGF receptor expression with ulcer healing by sulglycotide.

    PubMed

    Piotrowski, J; Majka, J; Sano, S; Nowak, P; Murty, V L; Slomiany, A; Slomiany, B L

    1995-07-01

    1. The effect of an antiulcer agent, sulglycotide, on mucosal expression of EGF and PDGF receptors with chronic ulcer healing was investigated. 2. Rats with experimentally-induced gastric ulcers were treated twice daily for 14 consecutive days, either with sulglycotide at 200 mg/kg or vehicle, and at different stages of treatment used for quantitation of gastric mucosal EGF and PDGF receptors. 3. The ulcer healing was accompanied by an increase in mucosal expression of both types of receptors. A 1.8-fold increase in EGF and 3.1-fold increase in PDGF receptors occurred by the 4th day following the development of ulcer and reached a maximum of 2.4-3.9-fold increase by the 10-14th day. 4. Treatment with sulglycotide caused accelerated ulcer healing accompanied by a significant enhancement in the receptors expression. A 2.3- and 3.6-fold increase in EGF and PDGF receptor expression occurred by the 4th day of sulglycotide treatment, reaching a 5.5- and 5.6-fold respective increase by the 10th day when the ulcer essentially healed. 5. The results attest to the ability of sulglycotide to stimulate the gastric mucosal proliferative activities associated with ulcer healing.

  19. Neutrophil Interactions with Epithelial Expressed ICAM-1 Enhances Intestinal Mucosal Wound Healing

    PubMed Central

    Sumagin, R; Brazil, JC; Nava, P; Nishio, H; Alam, A; Luissint, AC; Weber, DA; Neish, AS; Nusrat, A; Parkos, CA

    2015-01-01

    A characteristic feature of gastrointestinal tract inflammatory disorders, such as inflammatory bowel disease, is polymorphonuclear neutrophil (PMN) transepithelial migration (TEM) and accumulation in the gut lumen. PMN accumulation within the intestinal mucosa contributes to tissue injury. While epithelial infiltration by large numbers of PMNs results in mucosal injury, we found that PMN interactions with luminal epithelial membrane receptors may also play a role in wound healing. Intercellular adhesion molecule-1 (ICAM-1) is a PMN ligand that is upregulated on apical surfaces of intestinal epithelial cells under inflammatory conditions. In our study, increased expression of ICAM-1 resulted in enhanced PMN binding to the apical epithelium, which was associated with reduced PMN apoptosis. Following TEM, PMN adhesion to ICAM-1 resulted in activation of Akt and β-catenin signaling, increased epithelial-cell proliferation, and wound healing. Such responses were ICAM-1 dependent as engagement of epithelial ICAM-1 by antibody-mediated cross-linking yielded similar results. Furthermore, using an in-vivo biopsy-based, colonic-mucosal-injury model, we demonstrated epithelial ICAM-1 plays an important role in activation of epithelial Akt and β-catenin signaling and wound healing. These findings suggest that post-migrated PMNs within the intestinal lumen can regulate epithelial homeostasis, thereby identifying ICAM-1 as a potential therapeutic target for promoting mucosal wound healing. PMID:26732677

  20. Neutrophil interactions with epithelial-expressed ICAM-1 enhances intestinal mucosal wound healing.

    PubMed

    Sumagin, R; Brazil, J C; Nava, P; Nishio, H; Alam, A; Luissint, A C; Weber, D A; Neish, A S; Nusrat, A; Parkos, C A

    2016-09-01

    A characteristic feature of gastrointestinal tract inflammatory disorders, such as inflammatory bowel disease, is polymorphonuclear neutrophil (PMN) transepithelial migration (TEM) and accumulation in the gut lumen. PMN accumulation within the intestinal mucosa contributes to tissue injury. Although epithelial infiltration by large numbers of PMNs results in mucosal injury, we found that PMN interactions with luminal epithelial membrane receptors may also play a role in wound healing. Intercellular adhesion molecule-1 (ICAM-1) is a PMN ligand that is upregulated on apical surfaces of intestinal epithelial cells under inflammatory conditions. In our study, increased expression of ICAM-1 resulted in enhanced PMN binding to the apical epithelium, which was associated with reduced PMN apoptosis. Following TEM, PMN adhesion to ICAM-1 resulted in activation of Akt and β-catenin signaling, increased epithelial-cell proliferation, and wound healing. Such responses were ICAM-1 dependent as engagement of epithelial ICAM-1 by antibody-mediated cross-linking yielded similar results. Furthermore, using an in-vivo biopsy-based, colonic-mucosal-injury model, we demonstrated epithelial ICAM-1 has an important role in activation of epithelial Akt and β-catenin signaling and wound healing. These findings suggest that post-migrated PMNs within the intestinal lumen can regulate epithelial homeostasis, thereby identifying ICAM-1 as a potential therapeutic target for promoting mucosal wound healing.

  1. Mucosal stromal fibroblasts markedly enhance HIV infection of CD4+ T cells

    PubMed Central

    Kohgadai, Nargis; Müller, Janis A.; Laustsen, Anders; Thavachelvam, Karthiga; Stürzel, Christina M.; Jones, Jennifer J.; Somsouk, Ma; Garcia, Maurice M.; Smith, James F.; Greenblatt, Ruth M.; Münch, Jan; Jakobsen, Martin R.; Giudice, Linda C.; Greene, Warner C.; Roan, Nadia R.

    2017-01-01

    Understanding early events of HIV transmission within mucosal tissues is vital for developing effective prevention strategies. Here, we report that primary stromal fibroblasts isolated from endometrium, cervix, foreskin, male urethra, and intestines significantly increase HIV infection of CD4+ T cells–by up to 37-fold for R5-tropic HIV and 100-fold for X4-tropic HIV–without themselves becoming infected. Fibroblasts were more efficient than dendritic cells at trans-infection and mediate this response in the absence of the DC-SIGN and Siglec-1 receptors. In comparison, mucosal epithelial cells secrete antivirals and inhibit HIV infection. These data suggest that breaches in the epithelium allow external or luminal HIV to escape an antiviral environment to access the infection-favorable environment of the stromal fibroblasts, and suggest that resident fibroblasts have a central, but previously unrecognized, role in HIV acquisition at mucosal sites. Inhibiting fibroblast-mediated enhancement of HIV infection should be considered as a novel prevention strategy. PMID:28207890

  2. Enhancement of Microbiota in Healthy Macaques Results in Beneficial Modulation of Mucosal and Systemic Immune Function1

    PubMed Central

    Manuzak, Jennifer A.; Hensley-McBain, Tiffany; Zevin, Alexander S.; Miller, Charlene; Cubas, Rafael; Agricola, Brian; Gile, Jill; Richert-Spuhler, Laura; Patilea, Gabriela; Estes, Jacob D.; Langevin, Stanley; Reeves, R. Keith; Haddad, Elias K.; Klatt, Nichole R.

    2016-01-01

    Given the critical role of mucosal surfaces in susceptibility to infection, it is imperative that effective mucosal responses are induced when developing efficacious vaccines and prevention strategies for infection. Modulating the microbiota in the gastrointestinal (GI) tract through the use of probiotics (PBio) is a safe and well-tolerated approach to enhance mucosal and overall health. We assessed the longitudinal impact of daily treatment with the VSL#3 probiotic on cellular and humoral immunity and inflammation in healthy macaques. PBio therapy resulted in significantly increased frequencies of B cells expressing IgA in the colon and lymph node (LN), likely due to significantly increased LN T follicular helper cell (Tfh) frequencies and LN follicles. Increased frequencies of IL-23+ antigen presenting cells (APCs) in the colon were found post-PBio treatment, which correlated with LN Tfh. Finally, VSL#3 significantly down-modulated the response of TLR2, TLR3, TLR4 and TLR9-expressing HEK293 cells to stimulation with Pam3CSK4, Poly(I:C), LPS and ODN2006, respectively. These data provide a mechanism for the beneficial impact of PBio on mucosal health and implicates the use of PBio therapy in the context of vaccination or preventative approaches to enhance protection from mucosal infection by improving immune defenses at the mucosal portal of entry. PMID:26826246

  3. Intranasal Vaccination with Murabutide Enhances Humoral and Mucosal Immune Responses to a Virus-Like Particle Vaccine

    PubMed Central

    Jackson, Erin M.; Herbst-Kralovetz, Melissa M.

    2012-01-01

    Murabutide (MB) is a synthetic immunomodulator recognized by the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) receptor on mammalian cells. MB has previously been approved for testing in multiple human clinical trials to determine its value as an antiviral therapeutic, and as an adjuvant for injected vaccines. We have found a new use for this immunomodulator; it functions as a mucosal adjuvant that enhances immunogenicity of virus-like particles (VLP) administered intranasally. MB enhanced Norwalk virus (NV) VLP-specific IgG systemically and IgA production at distal mucosal sites following intranasal (IN) vaccination. A dose escalation study identified 100 µg as the optimal MB dosage in mice, based on the magnitude of VLP-specific IgG, IgG1, IgG2a and IgA production in serum and VLP-specific IgA production at distal mucosal sites. IN vaccination using VLP with MB was compared to IN delivery VLP with cholera toxin (CT) or gardiquimod (GARD) and to parenteral VLP delivery with alum; the MB groups were equivalent to CT and GARD and superior to alum in inducing mucosal immune responses and stimulated equivalent systemic VLP-specific antibodies. These data support the further testing of MB as a potent mucosal adjuvant for inducing robust and durable antibody responses to non-replicating subunit vaccines. PMID:22855691

  4. Polymeric enhancers of mucosal epithelia permeability: synthesis, transepithelial penetration-enhancing properties, mechanism of action, safety issues.

    PubMed

    Di Colo, Giacomo; Zambito, Ylenia; Zaino, Chiara

    2008-05-01

    Transmucosal drug administration across nasal, buccal, and ocular mucosae is noninvasive, eliminates hepatic first-pass metabolism and harsh environmental conditions, allows rapid onset, and further, mucosal surfaces are readily accessible. Generally, however, hydrophilic drugs, such as peptides and proteins, are poorly permeable across the epithelium, which results in insufficient bioavailability. Therefore, reversible modifications of epithelial barrier structure by permeation enhancers are required. Low molecular weight enhancers generally have physicochemical characteristics favoring their own absorption, whereas polymeric enhancers are not absorbed, and this minimizes the risk of systemic toxicity. The above considerations have warranted the present survey of the studies on polymeric transmucosal penetration-enhancers that have appeared in the literature during the last decade. Studies on intestinal permeation enhancers are also reviewed as they give information on the mechanism of action and safety of polymers. The synthesis and characterization of polymers, their effectiveness in enhancing the absorption of different drugs across different epithelium types, their mechanism of action and structure-efficacy relationship, and the relevant safety issues are reviewed. The active polymers are classified into: polycations (chitosan and its quaternary ammonium derivatives, poly-L-arginine (poly-L-Arg), aminated gelatin), polyanions (N-carboxymethyl chitosan, poly(acrylic acid)), and thiolated polymers (carboxymethyl cellulose-cysteine, polycarbophil (PCP)-cysteine, chitosan-thiobutylamidine, chitosan-thioglycolic acid, chitosan-glutathione conjugates).

  5. Genetic conjugation of components in two pneumococcal fusion protein vaccines enhances paediatric mucosal immune responses.

    PubMed

    Pope, Caroline; Oliver, Elizabeth H; Ma, Jiangtao; Langton Hewer, Claire; Mitchell, Tim J; Finn, Adam

    2015-03-30

    Streptococcus pneumoniae colonises the upper respiratory tract and can cause pneumonia, meningitis and otitis media. Existing pneumococcal conjugate vaccines are expensive to produce and only protect against 13 of the 90+ pneumococcal serotypes; hence there is an urgent need for the development of new vaccines. We have shown previously in mice that pneumolysin (Ply) and a non-toxic variant (Δ6Ply) enhance antibody responses when genetically fused to pneumococcal surface adhesin A (PsaA), a potentially valuable effect for future vaccines. We investigated this adjuvanticity in human paediatric mucosal primary immune cell cultures. Adenoidal mononuclear cells (AMNC) from children aged 0-15 years (n=46) were stimulated with conjugated, admixed or individual proteins, cell viability and CD4+ T-cell proliferative responses were assessed using flow cytometry and cytokine secretion was measured using multiplex technology. Proliferation of CD4+ T-cells in response to PsaAPly, was significantly higher than responses to individual or admixed proteins (p=0.002). In contrast, an enhanced response to PsaAΔ6Ply compared to individual or admixed proteins only occurred at higher concentrations (p<0.01). Evaluation of cytotoxicity suggested that responses occurred when Ply-induced cytolysis was inhibited, either by fusion or mutation, but importantly an additional toxicity independent immune enhancing effect was also apparent as a result of fusion. Responses were MHC class II dependent and had a Th1/Th17 profile. Genetic fusion of Δ6Ply to PsaA significantly modulates and enhances pro-inflammatory CD4+ T-cell responses without the cytolytic effects of some other pneumolysoids. Membrane binding activity of such proteins may confer valuable adjuvant properties as fusion may assist Δ6Ply to deliver PsaA to the APC surface effectively, contributing to the initiation of anti-pneumococcal CD4+ T-cell immunity.

  6. Novel Mucosal DNA-MVA HIV Vaccination in Which DNA-IL-12 Plus Cholera Toxin B Subunit (CTB) Cooperates to Enhance Cellular Systemic and Mucosal Genital Tract Immunity

    PubMed Central

    Holgado, María Pía; Falivene, Juliana; Gherardi, María Magdalena

    2014-01-01

    Induction of local antiviral immune responses at the mucosal portal surfaces where HIV-1 and other viral pathogens are usually first encountered remains a primary goal for most vaccines against mucosally acquired viral infections. Exploring mucosal immunization regimes in order to find optimal vector combinations and also appropriate mucosal adjuvants in the HIV vaccine development is decisive. In this study we analyzed the interaction of DNA-IL-12 and cholera toxin B subunit (CTB) after their mucosal administration in DNA prime/MVA boost intranasal regimes, defining the cooperation of both adjuvants to enhance immune responses against the HIV-1 Env antigen. Our results demonstrated that nasal mucosal DNA/MVA immunization schemes can be effectively improved by the co-delivery of DNA-IL-12 plus CTB inducing elevated HIV-specific CD8 responses in spleen and more importantly in genital tract and genito-rectal draining lymph nodes. Remarkably, these CTL responses were of superior quality showing higher avidity, polyfunctionality and a broader cytokine profile. After IL-12+CTB co-delivery, the cellular responses induced showed an enhanced breadth recognizing with higher efficiency Env peptides from different subtypes. Even more, an in vivo CTL cytolytic assay demonstrated the higher specific CD8 T-cell performance after the IL-12+CTB immunization showing in an indirect manner its potential protective capacity. Improvements observed were maintained during the memory phase where we found higher proportions of specific central memory and T memory stem-like cells T-cell subpopulations. Together, our data show that DNA-IL-12 plus CTB can be effectively employed acting as mucosal adjuvants during DNA prime/MVA boost intranasal vaccinations, enhancing magnitude and quality of HIV-specific systemic and mucosal immune responses. PMID:25215887

  7. Distinct TRPV1- and TRPA1-based mechanisms underlying enhancement of oral ulcerative mucositis-induced pain by 5-fluorouracil.

    PubMed

    Yamaguchi, Kiichiro; Ono, Kentaro; Hitomi, Suzuro; Ito, Misa; Nodai, Tomotaka; Goto, Tetsuya; Harano, Nozomu; Watanabe, Seiji; Inoue, Hiromasa; Miyano, Kanako; Uezono, Yasuhito; Matoba, Motohiro; Inenaga, Kiyotoshi

    2016-05-01

    In many patients with cancer, chemotherapy-induced severe oral ulcerative mucositis causes intractable pain, leading to delays and interruptions in therapy. However, the pain mechanism in oral ulcerative mucositis after chemotherapy has not been extensively studied. In this study, we investigated spontaneous pain and mechanical allodynia in a preclinical model of oral ulcerative mucositis after systemic administration of the chemotherapy drug 5-fluorouracil, using our proprietary pain assay system for conscious rats. 5-Fluorouracil caused leukopenia but did not induce pain-related behaviors. After 5-fluorouracil administration, oral ulcers were developed with topical acetic acid treatment. Compared with saline-treated rats, 5-fluorouracil-exposed rats showed more severe mucositis with excessive bacterial loading due to a lack of leukocyte infiltration, as well as enhancements of spontaneous pain and mechanical allodynia. Antibacterial drugs, the lipid A inhibitor polymyxin B and the TRPV1/TRPA1 channel pore-passing anesthetic QX-314, suppressed both the spontaneous pain and the mechanical allodynia. The cyclooxygenase inhibitor indomethacin and the TRPV1 antagonist SB-366791 inhibited the spontaneous pain, but not the mechanical allodynia. In contrast, the TRPA1 antagonist HC-030031 and the N-formylmethionine receptor FPR1 antagonist Boc MLF primarily suppressed the mechanical allodynia. These results suggest that 5-fluorouracil-associated leukopenia allows excessive oral bacterial infection in the oral ulcerative region, resulting in the enhancement of spontaneous pain through continuous TRPV1 activation and cyclooxygenase pathway, and mechanical allodynia through mechanical sensitization of TRPA1 caused by neuronal effects of bacterial toxins. These distinct pain mechanisms explain the difficulties encountered with general treatments for oral ulcerative mucositis-induced pain in patients with cancer and suggest more effective approaches.

  8. Enhanced Mucosal Antibody Production and Protection against Respiratory Infections Following an Orally Administered Bacterial Extract

    PubMed Central

    Pasquali, Christian; Salami, Olawale; Taneja, Manisha; Gollwitzer, Eva S.; Trompette, Aurelien; Pattaroni, Céline; Yadava, Koshika; Bauer, Jacques; Marsland, Benjamin J.

    2014-01-01

    Secondary bacterial infections following influenza infection are a pressing problem facing respiratory medicine. Although antibiotic treatment has been highly successful over recent decades, fatalities due to secondary bacterial infections remain one of the leading causes of death associated with influenza. We have assessed whether administration of a bacterial extract alone is sufficient to potentiate immune responses and protect against primary infection with influenza, and secondary infections with either Streptococcus pneumoniae or Klebsiella pneumoniae in mice. We show that oral administration with the bacterial extract, OM-85, leads to a maturation of dendritic cells and B-cells characterized by increases in MHC II, CD86, and CD40, and a reduction in ICOSL. Improved immune responsiveness against influenza virus reduced the threshold of susceptibility to secondary bacterial infections, and thus protected the mice. The protection was associated with enhanced polyclonal B-cell activation and release of antibodies that were effective at neutralizing the virus. Taken together, these data show that oral administration of bacterial extracts provides sufficient mucosal immune stimulation to protect mice against a respiratory tract viral infection and associated sequelae. PMID:25593914

  9. Medroxyprogesterone acetate and levonorgestrel increase genital mucosal permeability and enhance susceptibility to genital herpes simplex virus type 2 infection.

    PubMed

    Quispe Calla, N E; Vicetti Miguel, R D; Boyaka, P N; Hall-Stoodley, L; Kaur, B; Trout, W; Pavelko, S D; Cherpes, T L

    2016-11-01

    Depot-medroxyprogesterone acetate (DMPA) is a hormonal contraceptive especially popular in areas with high prevalence of HIV and other sexually transmitted infections (STI). Although observational studies identify DMPA as an important STI risk factor, mechanisms underlying this connection are undefined. Levonorgestrel (LNG) is another progestin used for hormonal contraception, but its effect on STI susceptibility is much less explored. Using a mouse model of genital herpes simplex virus type 2 (HSV-2) infection, we herein found that DMPA and LNG similarly reduced genital expression of the desmosomal cadherin desmoglein-1α (DSG1α), enhanced access of inflammatory cells to genital tissue by increasing mucosal epithelial permeability, and increased susceptibility to viral infection. Additional studies with uninfected mice revealed that DMPA-mediated increases in mucosal permeability promoted tissue inflammation by facilitating endogenous vaginal microbiota invasion. Conversely, concomitant treatment of mice with DMPA and intravaginal estrogen restored mucosal barrier function and prevented HSV-2 infection. Evaluating ectocervical biopsy tissue from women before and 1 month after initiating DMPA remarkably revealed that inflammation and barrier protection were altered by treatment identically to changes seen in progestin-treated mice. Together, our work reveals DMPA and LNG diminish the genital mucosal barrier; a first-line defense against all STI, but may offer foundation for new contraceptive strategies less compromising of barrier protection.

  10. Medroxyprogesterone acetate and levonorgestrel increase genital mucosal permeability and enhance susceptibility to genital herpes simplex virus type 2 infection

    PubMed Central

    Calla, Nirk E Quispe; Miguel, Rodolfo D Vicetti; Boyaka, Prosper N; Hall-Stoodley, Luanne; Kaur, Balveen; Trout, Wayne; Pavelko, Stephen D; Cherpes, Thomas L

    2016-01-01

    Depot-medroxyprogesterone acetate (DMPA) is a hormonal contraceptive especially popular in areas with high prevalence of HIV and other sexually transmitted infections (STI). While observational studies identify DMPA as an important STI risk factor, mechanisms underlying this connection are undefined. Levonorgestrel (LNG) is another progestin used for hormonal contraception, but its effect on STI susceptibility is much less explored. Using a mouse model of genital HSV-2 infection, we herein found DMPA and LNG similarly reduced genital expression of the desmosomal cadherin desmoglein-1α (DSG1α), enhanced access of inflammatory cells to genital tissue by increasing mucosal epithelial permeability, and increased susceptibility to viral infection. Additional studies with uninfected mice revealed DMPA-mediated increases in mucosal permeability promoted tissue inflammation by facilitating endogenous vaginal microbiota invasion. Conversely, concomitant treatment of mice with DMPA and intravaginal estrogen restored mucosal barrier function and prevented HSV-2 infection. Evaluating ectocervical biopsy tissue from women before and 1 month after initiating DMPA remarkably revealed inflammation and barrier protection were altered by treatment identically to changes seen in progestin-treated mice. Together, our work reveals DMPA and LNG diminish the genital mucosal barrier; a first-line defense against all STI, but may offer foundation for new contraceptive strategies less compromising of barrier protection. PMID:27007679

  11. Enhanced aqueous photochemical reaction rates after freezing.

    PubMed

    Grannas, Amanda M; Bausch, Alexandra R; Mahanna, Kendell M

    2007-11-01

    Sunlit snow/ice is known to play an important role in the processing of atmospheric species, including photochemical production of NO(x), HONO, molecular halogens, alkyl halides, and carbonyl compounds, among others. It has been shown that a liquid-like (quasi-liquid or disordered) layer exists on the surface of pure ice and that this quasi-liquid layer is also found on the surface of ambient snow crystals and ice at temperatures similar to polar conditions. However, it is unclear what role the liquid-like fractions present in and on frozen water play in potential photochemical reactions, particularly with regard to organic substrates. Here, we report a detailed study of enhanced rates of photochemical nucleophilic substitution of p-nitroanisole (PNA) with pyridine, a well-characterized and commonly used actinometer system. Reaction rates were enhanced by a factor of up to approximately 40 when frozen at temperatures between 236 and 272 K. Reaction rates were dependent on temperature and solute concentration, both variables that control the nature of the liquid-like fraction in frozen water. The results obtained indicate that a major portion of the organic solutes is excluded to the liquid-like layer, significantly impacting the rate of the photochemical nucleophilic substitution reaction studied here. Also, the direct comparison of liquid-phase kinetics to reactions occurring in frozen water systems is drawn into question, indicating that a simple extrapolation of liquid-phase mechanisms to snow/ice may not be valid for certain reactions.

  12. N-succinyl chitosan as buccal penetration enhancer for delivery of herbal agents in treatment of oral mucositis.

    PubMed

    Dhawan, Neha; Kumar, Krishan; Kalia, A N; Arora, Saahil

    2014-01-01

    Oral mucositis is one of the major side effects of cancer chemotherapy (30-76%) and radiotherapy (over 50%). Current palliative treatments of oral mucositis include specialized agents like pelifermin, platelet derived factors etc. or oral hygienic agents which suffered from various drawbacks like systemic side effect, least effect owing to fast wash out of buccal mucosa, patient unfriendly delivery systems, and mere symptomatic relief. In this research work, N-succinyl chitosan gel delivery system of microemulsified eugenol, honey and sodium hyaluronate was prepared to explore their multiple and synergistic effects on various pathological factors of oral mucositis. N-succinyl chitosan was synthesized in our laboratory and loaded with microemulsified eugenol (10% v/v), honey (10% v/v) and sodium hyaluronate (0.2% w/v) to prepare orogel with optimum pH, spreadability, mucoadhesion strength, and viscosity. In vitro eugenol release from N-succinyl chitosan gel after 8 hours in PBS (pH-6.4) was found to be 87.45±0.14%, which was better in comparison to that released from chitosan gel. Ex vivo penetration studies using rat buccal mucosal tissue also suggested better J-efflux of eugenol through N-succinyl chitosan in comparison to chitosan gel with enhancement ratio (ER) of 1.71. The antimicrobial effect of N-succinyl chitosan based orogel against S. aureus and C. albicans efficacy was found to be statistically high in comparison to chitosan based orogel as well as marketed formulation of chlorhexidine (p<0.05). The N-succinyl chitosan orogel in 5-fluoro uracil induced oral mucositis animal (Wistar rats) model showed enhanced survival ratio, weight gain and high tissue regeneration activity than chitosan gel formulation within 15 days. The formulation was successful in elevating the survival and reducing the inflammation in the oral mucosa of animals compared to disease control (p<0.05) and hence suggesting the potential of N-succinyl chitosan orogel in the treatment of

  13. Sublingual delivery of insulin: effects of enhancers on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity.

    PubMed

    Cui, Chun-Ying; Lu, Wan-Liang; Xiao, Lan; Zhang, Shuang-Qing; Huang, Yan-Bei; Li, Sheng-Lin; Zhang, Rui-Juan; Wang, Gui-Ling; Zhang, Xuan; Zhang, Qiang

    2005-12-01

    The purposes of this study were to evaluate effects of enhancers for sublingual delivering insulin on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity in normal rats. The effects on sublingual mucosa, and aggregation states of insulin were estimated using fluorescence polarization, and circular dichroism method, respectively. The human immortalized oral epithelial cell monolayer was used for evaluating transport of insulin. Hydroxylpropyl-beta-cyclodextrin (HP-beta-CD), chitosan, polyethylene-polypropylene glycol, polyoxyethylene lauryl ether, polysorbate 80, egg lecithin, or oleic acid, was used as a penetration enhancer, respectively. The fluidity of sublingual mucosal lipid was markedly reduced by these enhancers excluding polysorbate 80, and the secondary structure of the mucosal proteins was also influenced by these enhancers. The hexamers of insulin were dissociated to monomers only by chitosan, polyoxyethylene lauryl ether, and egg lecithin. Nonetheless, plasma glucose levels in normal rats were significantly lowered after sublingual administration of insulin with an enhancer compared with those without an enhancer at the same time-point. The enhancing effects may be due to one or multiple factors: increasing the mucosal lipid fluidity, directly loosing the tight junction of epithelia, and dissociating the hexamers of insulin to monomers. Among these, the opened tight junction may correlate most with the enhancing effect in the mucosal permeability. Because the aggregates of insulin exist, the dissociation of the aggregates by an enhancer would benefit the permeability.

  14. AdHu5Ag85A Respiratory Mucosal Boost Immunization Enhances Protection against Pulmonary Tuberculosis in BCG-Primed Non-Human Primates.

    PubMed

    Jeyanathan, Mangalakumari; Shao, Zhongqi; Yu, Xuefeng; Harkness, Robin; Jiang, Rong; Li, Junqiang; Xing, Zhou; Zhu, Tao

    2015-01-01

    Persisting high global tuberculosis (TB) morbidity and mortality and poor efficacy of BCG vaccine emphasizes an urgent need for developing effective novel boost vaccination strategies following parenteral BCG priming in humans. Most of the current lead TB vaccine candidates in the global pipeline were developed for parenteral route of immunization. Compelling evidence indicates respiratory mucosal delivery of vaccine to be the most effective way to induce robust local mucosal protective immunity against pulmonary TB. However, despite ample supporting evidence from various animal models, there has been a lack of evidence supporting the safety and protective efficacy of respiratory mucosal TB vaccination in non-human primates (NHP) and humans. By using a rhesus macaque TB model we have evaluated the safety and protective efficacy of a recombinant human serotype 5 adenovirus-based TB vaccine (AdHu5Ag85A) delivered via the respiratory mucosal route. We show that mucosal AdHu5Ag85A boost immunization was safe and well tolerated in parenteral BCG-primed rhesus macaques. A single AdHu5Ag85A mucosal boost immunization in BCG-primed rhesus macaques enhanced the antigen-specific T cell responses. Boost immunization significantly improved the survival and bacterial control following M.tb challenge. Furthermore, TB-related lung pathology and clinical outcomes were lessened in BCG-primed, mucosally boosted animals compared to control animals. Thus, for the first time we show that a single respiratory mucosal boost immunization with a novel TB vaccine enhances protection against pulmonary TB in parenteral BCG-primed NHP. Our study provides the evidence for the protective potential of AdHu5Ag85A as a respiratory mucosal boost TB vaccine for human application.

  15. Mucosal vaccines

    PubMed Central

    Nizard, Mevyn; Diniz, Mariana O; Roussel, Helene; Tran, Thi; Ferreira, Luis CS; Badoual, Cecile; Tartour, Eric

    2014-01-01

    The mucosal immune system displays several adaptations reflecting the exposure to the external environment. The efficient induction of mucosal immune responses also requires specific approaches, such as the use of appropriate administration routes and specific adjuvants and/or delivery systems. In contrast to vaccines delivered via parenteral routes, experimental, and clinical evidences demonstrated that mucosal vaccines can efficiently induce local immune responses to pathogens or tumors located at mucosal sites as well as systemic response. At least in part, such features can be explained by the compartmentalization of mucosal B and T cell populations that play important roles in the modulation of local immune responses. In the present review, we discuss molecular and cellular features of the mucosal immune system as well as novel immunization approaches that may lead to the development of innovative and efficient vaccines targeting pathogens and tumors at different mucosal sites. PMID:25424921

  16. Endogenous IL-21 regulates pathogenic mucosal CD4 T-cell responses during enhanced RSV disease in mice

    PubMed Central

    Dodd, J S; Clark, D; Muir, R; Korpis, C; Openshaw, P J M

    2013-01-01

    A role for interleukin-21 (IL-21) has recently been found in several diseases, but contribution to mucosal defences has not been described. In BALB/c mice infected with respiratory syncytial virus (RSV), IL-21 depletion had little effect in primary infection. However, depletion of mice during priming with recombinant vaccinia expressing RSV G protein (which primes RSV-specific T helper type 2 cells and causes lung eosinophilia during RSV infection) further exacerbated pathology during RSV challenge, with reduced viral clearance and impaired virus-specific serum antibody responses. This enhancement was accompanied by lymphocyte, neutrophil, and antigen-presenting cell recruitment to the lungs, with increased bronchoalveolar lavage interferon-γ and IL-17 levels. Adoptive transfer of splenic CD4 T cells from depleted mice into naive recipients replicated these effects, indicating that IL-21 mediates its effects via CD4 T cells. Endogenous IL-21, therefore, has potent and specific effects on mucosal antiviral responses, assisting viral clearance, regulating pulmonary T- and B-cell responses, and inhibiting IL-17 production. PMID:23168836

  17. Delivery of optical contrast agents using Triton-X100, part 2: enhanced mucosal permeation for the detection of cancer biomarkers

    NASA Astrophysics Data System (ADS)

    van de Ven, Anne L.; Adler-Storthz, Karen; Richards-Kortum, Rebecca

    2009-03-01

    Uniform delivery of optical contrast agents through mucosal tissue has proven a significant challenge. Topical permeation enhancers that have proven useful for skin demonstrate limited success in mucosal tissue. We sought to develop a topical permeation strategy capable of delivering tissue-impermeant molecular-specific contrast agents through mucosal epithelium in a uniform, controlled manner. We demonstrate that Triton-X100 can be utilized to deliver targeted and untargeted optical contrast agents through freshly excised normal mucosal epithelium and epithelial cancer. Macromolecules up to 150 kDa in size were successfully delivered via transcellular and paracellular routes. The depth of Triton-mediated permeation was modulated by varying the treatment time and concentration. Uniform epithelial penetration to a depth of 500 μm was achieved in ~1.5 h for molecules of 40 kDa or less. Larger optical probes required longer treatment times. Coadministration of molecular-specific contrast agents with Triton-X100 treatment facilitated simultaneous labeling of biomarkers on the cell membrane, in the cytoplasm, and in the nucleus with high specificity. Together, these data suggest that Triton-X100 is a promising topical permeation enhancer for mucosal delivery of tissue-impermeant molecular-specific optical contrast agents.

  18. Enhancement of mucosal immune responses in chickens by oral administration of cysteamine.

    PubMed

    Yang, Q; Lian, G; Gong, X

    2007-07-01

    Somatostatin, a tetradecapeptide originally isolated from the hypothalamus, can exert an inhibitory effect on the secretion of growth hormone by the anterior pituitary gland. In addition to endocrine organs, somatostatin is also present in the digestive tract and immune organs. In lymphoid tissues, somatostatin appears to play a role in the modulation of the immune response. Cysteamine (CS) is a sulfhydryl reducing agent that is known as a depletory agent of somatostatin. To evaluate its effects on chicken mucosal immune responses, CS was administrated orally to 1-wk-old broilers (40 mg/kg) that were immunized orally with Newcastle disease attenuated vaccine (NDV). The number of IgA-positive cells and intestinal intraepithelial lymphocytes (iIEL) in duodenum and jejunum were examined at 3-, 5-, and 7-wk posttreatment and immunization. The number of somatostatin-positive cells and relative amounts of somatostatin mRNA were also examined in the duodenum. The number of somatostatin-positive cells in the duodenum was reduced (P < 0.05) after CS treatment. In broilers receiving CS and NDV treatment (CS+NDV) the level of IgA-positive cells and iIEL in the duodenum and jejunum was increased (P < 0.05) at 3 and 5 wk posttreatment. The expression of somatostatin mRNA increased (P < 0.05) compared with that of the control group at 5 wk after immunization in broilers receiving CS+NDV or NDV alone. The results suggest that CS can induce proliferation and differentiation of IgA-positive cells and iIEL in the intestinal mucosa of chickens by reducing the number of somatostatin-positive cells.

  19. M cell-targeting strategy facilitates mucosal immune response and enhances protection against CVB3-induced viral myocarditis elicited by chitosan-DNA vaccine.

    PubMed

    Ye, Ting; Yue, Yan; Fan, Xiangmei; Dong, Chunsheng; Xu, Wei; Xiong, Sidong

    2014-07-31

    Efficient delivery of antigen to mucosal associated lymphoid tissue is a first and critical step for successful induction of mucosal immunity by vaccines. Considering its potential transcytotic capability, M cell has become a more and more attractive target for mucosal vaccines. In this research, we designed an M cell-targeting strategy by which mucosal delivery system chitosan (CS) was endowed with M cell-targeting ability via conjugating with a CPE30 peptide, C terminal 30 amino acids of clostridium perfringens enterotoxin (CPE), and then evaluated its immune-enhancing ability in the context of coxsackievirus B3 (CVB3)-specific mucosal vaccine consisting of CS and a plasmid encoding CVB3 predominant antigen VP1. It had shown that similar to CS-pVP1, M cell-targeting CPE30-CS-pVP1 vaccine appeared a uniform spherical shape with about 300 nm diameter and +22 mV zeta potential, and could efficiently protect DNA from DNase I digestion. Mice were orally immunized with 4 doses of CPE30-CS-pVP1 containing 50 μg pVP1 at 2-week intervals and challenged with CVB3 4 weeks after the last immunization. Compared with CS-pVP1 vaccine, CPE30-CS-pVP1 vaccine had no obvious impact on CVB3-specific serum IgG level and splenic T cell immune responses, but significantly increased specific fecal SIgA level and augmented mucosal T cell immune responses. Consequently, much milder myocarditis and lower viral load were witnessed in CPE30-CS-pVP1 immunized group. The enhanced immunogenicity and immunoprotection were associated with the M cell-targeting ability of CPE30-CS-pVP1 which improved its mucosal uptake and transcytosis. Our findings indicated that CPE30-CS-pVP1 may represent a novel prophylactic vaccine against CVB3-induced myocarditis, and this M cell-targeting strategy indeed could be applied as a promising and universal platform for mucosal vaccine development.

  20. POZylation: a new approach to enhance nanoparticle diffusion through mucosal barriers

    NASA Astrophysics Data System (ADS)

    Mansfield, Edward D. H.; Sillence, Katy; Hole, Patrick; Williams, Adrian C.; Khutoryanskiy, Vitaliy V.

    2015-08-01

    The increasing use of nanoparticles in the pharmaceutical industry is generating concomitant interest in developing nanomaterials that can rapidly penetrate into, and permeate through, biological membranes to facilitate drug delivery and improve the bioavailability of active pharmaceutical ingredients. Here, we demonstrate that the permeation of thiolated silica nanoparticles through porcine gastric mucosa can be significantly enhanced by their functionalization with either 5 kDa poly(2-ethyl-2-oxazoline) or poly(ethylene glycol). Nanoparticle diffusion was assessed using two independent techniques; Nanoparticle Tracking Analysis, and fluorescence microscopy. Our results show that poly(2-ethyl-2-oxazoline) and poly(ethylene glycol) have comparable abilities to enhance diffusion of silica nanoparticles in mucin dispersions and through the gastric mucosa. These findings provide a new strategy in the design of nanomedicines, by surface modification or nanoparticle core construction, for enhanced transmucosal drug delivery.The increasing use of nanoparticles in the pharmaceutical industry is generating concomitant interest in developing nanomaterials that can rapidly penetrate into, and permeate through, biological membranes to facilitate drug delivery and improve the bioavailability of active pharmaceutical ingredients. Here, we demonstrate that the permeation of thiolated silica nanoparticles through porcine gastric mucosa can be significantly enhanced by their functionalization with either 5 kDa poly(2-ethyl-2-oxazoline) or poly(ethylene glycol). Nanoparticle diffusion was assessed using two independent techniques; Nanoparticle Tracking Analysis, and fluorescence microscopy. Our results show that poly(2-ethyl-2-oxazoline) and poly(ethylene glycol) have comparable abilities to enhance diffusion of silica nanoparticles in mucin dispersions and through the gastric mucosa. These findings provide a new strategy in the design of nanomedicines, by surface modification or

  1. Enhancement of Sonochemical Reaction by Dual-Pulse Ultrasound

    NASA Astrophysics Data System (ADS)

    Xu, Zheng; Yasuda, Keiji

    2011-07-01

    In order to apply sonochemistry in wastewater treatment, enhancement of sonochemical reaction is necessary. Oxidation of potassium iodide and the degradation of acid orange 7 in aqueous solution using ultrasound irradiation were performed at 490 kHz. Power-modulated pulsed waves were employed and the enhancement of reaction amount was observed compared with using continuous wave. The enhancement ratio for irradiation to rigid wall was larger than that for irradiation to free surface. Moreover, the best modulated pulsed on time was experimentally determined and the effect of the superposition of pulsed waves (dual-pulse) was studied. Enhancement was also observed and calculated separately when using dual-pulse ultrasound. The enhancement upon the use of the dual-transducer was ascribed to the enlargement of sonochemical reaction field. The enhancement upon the incorporating pulsed waves was ascribed to both the reduction of reaction threshold effect and the residual acoustical pressure at the pulsed off time.

  2. Enhanced nasal mucosal delivery and immunogenicity of anti-caries DNA vaccine through incorporation of anionic liposomes in chitosan/DNA complexes.

    PubMed

    Chen, Liulin; Zhu, Junming; Li, Yuhong; Lu, Jie; Gao, Li; Xu, Huibi; Fan, Mingwen; Yang, Xiangliang

    2013-01-01

    The design of optimized nanoparticles offers a promising strategy to enable DNA vaccines to cross various physiological barriers for eliciting a specific and protective mucosal immunity via intranasal administration. Here, we reported a new designed nanoparticle system through incorporating anionic liposomes (AL) into chitosan/DNA (CS/DNA) complexes. With enhanced cellular uptake, the constructed AL/CS/DNA nanoparticles can deliver the anti-caries DNA vaccine pGJA-P/VAX into nasal mucosa. TEM results showed the AL/CS/DNA had a spherical structure. High DNA loading ability and effective DNA protection against nuclease were proved by gel electrophoresis. The surface charge of the AL/CS/DNA depended strongly on pH environment, enabling the intracellular release of loaded DNA via a pH-mediated manner. In comparison to the traditional CS/DNA system, our new design rendered a higher transfection efficiency and longer residence time of the AL/CS/DNA at nasal mucosal surface. These outstanding features enable the AL/CS/DNA to induce a significantly (p<0.01) higher level of secretory IgA (SIgA) than the CS/DNA in animal study, and a longer-term mucosal immunity. On the other hand, the AL/CS/DNA exhibited minimal cytotoxicity. These results suggest that the developed nanoparticles offer a potential platform for DNA vaccine packaging and delivery for more efficient elicitation of mucosal immunity.

  3. Cyanohydrin reactions enhance glycolytic oscillations in yeast.

    PubMed

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian; Sørensen, Preben Graae

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here, (13)C NMR is used to confirm our previous hypothesis, that cyanide directly affects glycolytic fluxes through reaction with carbonyl-containing compounds. Intracellularly, at least 3 cyanohydrins were identified. Extracellularly, all signals could be identified and lactonitrile was found to account for ~66% of total cyanide removal. Simulations of our updated computational model show that intracellular cyanide reactions increase the amplitude of oscillations and that cyanide addition lowers [ACA] instantaneously. We conclude that cyanide provides the following means of inducing global oscillations: a) by reducing [ACAx] relative to oscillation amplitude, b) by targeting multiple intracellular carbonyl compounds during fermentation, and c) by acting as a phase resetting stimulus.

  4. Optimal stretching of fluid for enhancing reaction growth

    NASA Astrophysics Data System (ADS)

    Nevins, Thomas; Kelley, Douglas

    2016-11-01

    When a biological or chemical scalar grows in flowing fluid, the resulting reacted region is dependent on both the details of the flow, and the reaction kinetics. We simultaneously film reaction state and flow in a laboratory model of reactive mixing in order to examine reactive mixing in physical, time-dependent flows. Using the excitable Belousov-Zhabotinsky (BZ) reaction, we find an optimal stretching range in which the flow enhances reaction, but larger stretching causes reaction blowout. We observe the transition from flow mostly helping to mostly blowout is not associated with the transition to turbulence, and that stretching fields (closely related to finite-time Lyapunov exponents) inside the optimal range appear to have a large effect on reaction growth rate locally. We also present estimates of the optimal stretching for BZ, and hypothesize that it is a feature exclusive to excitable reactions.

  5. A Novel Peptide for Simultaneously Enhanced Treatment of Head and Neck Cancer and Mitigation of Oral Mucositis

    PubMed Central

    Chen, Peili; Mancini, Maria; Sonis, Stephen T.; Fernandez-Martinez, Juan; Liu, Jing; Cohen, Ezra E. W.; Toback, F. Gary

    2016-01-01

    We have characterized a novel 21 amino acid-peptide derived from Antrum Mucosal Protein (AMP)-18 that mediates growth promotion of cultured normal epithelial cells and mitigates radiation-induced oral mucositis in animal models, while suppressing in vitro function of cancer cells. The objective of this study was to evaluate these dual potential therapeutic effects of AMP peptide in a clinically relevant animal model of head and neck cancer (HNC) by simultaneously assessing its effect on tumor growth and radiation-induced oral mucositis in an orthotopic model of HNC. Bioluminescent SCC-25 HNC cells were injected into the anterior tongue and tumors that formed were then subjected to focal radiation treatment. Tumor size was assessed using an in vivo imaging system, and the extent of oral mucositis was compared between animals treated with AMP peptide or vehicle (controls). Synergism between AMP peptide and radiation therapy was suggested by the finding that tumors in the AMP peptide/radiation therapy cohort demonstrated inhibited growth vs. radiation therapy-only treated tumors, while AMP peptide-treatment delayed the onset and reduced the severity of radiation therapy-induced oral mucositis. A differential effect on apoptosis appears to be one mechanism by which AMP-18 can stimulate growth and repair of injured mucosal epithelial cells while inhibiting proliferation of HNC cells. RNA microarray analysis identified pathways that are differentially targeted by AMP-18 in HNC vs. nontransformed cells. These observations confirm the notion that normal cells and tumor cells may respond differently to common biological stimuli, and that leveraging this finding in the case of AMP-18 may provide a clinically relevant opportunity. PMID:27049860

  6. Cell-Associated Flagella Enhance the Protection Conferred by Mucosally-Administered Attenuated Salmonella Paratyphi A Vaccines

    PubMed Central

    Gat, Orit; Galen, James E.; Tennant, Sharon; Simon, Raphael; Blackwelder, William C.; Silverman, David J.; Pasetti, Marcela F.; Levine, Myron M.

    2011-01-01

    Background Antibiotic-resistant Salmonella enterica serovar Paratyphi A, the agent of paratyphoid A fever, poses an emerging public health dilemma in endemic areas of Asia and among travelers, as there is no licensed vaccine. Integral to our efforts to develop a S. Paratyphi A vaccine, we addressed the role of flagella as a potential protective antigen by comparing cell-associated flagella with exported flagellin subunits expressed by attenuated strains. Methodology S. Paratyphi A strain ATCC 9150 was first deleted for the chromosomal guaBA locus, creating CVD 1901. Further chromosomal deletions in fliD (CVD 1901D) or flgK (CVD 1901K) were then engineered, resulting in the export of unpolymerized FliC, without impairing its overall expression. The virulence of the resulting isogenic strains was examined using a novel mouse LD50 model to accommodate the human-host restricted S. Paratyphi A. The immunogenicity of the attenuated strains was then tested using a mouse intranasal model, followed by intraperitoneal challenge with wildtype ATCC 9150. Results Mucosal (intranasal) immunization of mice with strain CVD 1901 expressing cell-associated flagella conferred superior protection (vaccine efficacy [VE], 90%) against a lethal intraperitoneal challenge, compared with the flagellin monomer-exporting mutants CVD 1901K (30% VE) or CVD 1901D (47% VE). The superior protection induced by CVD 1901 with its cell-attached flagella was associated with an increased IgG2a∶IgG1 ratio of FliC-specific antibodies with enhanced opsonophagocytic capacity. Conclusions Our results clearly suggest that enhanced anti-FliC antibody-mediated clearance of S. Paratyphi A by phagocytic cells, induced by vaccines expressing cell-associated rather than exported FliC, might be contributing to the vaccine-induced protection from S. Paratyphi A challenge in vivo. We speculate that an excess of IgG1 anti-FliC antibodies induced by the exported FliC may compete with the IgG2a subtype and block

  7. Grape Seed Extract Dose-Responsively Decreases Disease Severity in a Rat Model of Mucositis; Concomitantly Enhancing Chemotherapeutic Effectiveness in Colon Cancer Cells

    PubMed Central

    Cheah, Ker Yeaw; Howarth, Gordon Stanley; Bastian, Susan Elaine Putnam

    2014-01-01

    Objective Mucositis is a serious disorder of the gastrointestinal tract that results from cancer chemotherapy. We investigated the effects of increasing grape seed extract doses on the severity of chemotherapy in a rat model and its coincident impact on chemotherapeutic effectiveness in colon cancer cells. Design Female Dark Agouti rats were gavaged with grape seed extract (400–1000 mg/kg) or water (day 3–11) and were injected intraperitoneally with 5-Fluorouracil (150 mg/kg) or saline (control) on day 9 to induce mucositis. Daily metabolic data were collected and rats were sacrificed on day 12. Intestinal tissues were collected for histological and myeloperoxidase analyses. Caco-2 cell viability was examined in response to grape seed extract in combination with 5-Fluorouracil by 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) assay. Results Compared with 5-Fluorouracil controls, grape seed extract (400–1000 mg/kg) significantly decreased the histological damage score (P<0.05) in the jejunum. Grape seed extract (1000 mg/kg) increased jejunal crypt depth by 25% (P<0.05) in 5-Fluorouracil treated rats compared to 5-Fluorouracil controls, and attenuated the 5-Fluorouracil -induced reduction of mucosal thickness (25%, P<0.05). Grape seed extract (600 mg/kg) decreased myeloperoxidase activity by 55% (P<0.01) compared to 5-Fluorouracil controls. Grape seed extract was more effective at ameliorating 5-Fluorouracil induced intestinal injury, with effects most pronounced in the proximal jejunum. Grape seed extract (10–25 ug/mL) significantly enhanced the growth-inhibitory effects of 5-Fluorouracil by 26% (P<0.05) in Caco-2 cells and was more potent than 5-Fluorouracil at 50–100 µg/mL. Conclusion Grape seed extract may represent a new therapeutic option to decrease the symptoms of intestinal mucositis while concurrently impacting on the viability of colon cancer cells. PMID:24465501

  8. The importance of local mucosal HIV-specific CD8(+) cytotoxic T lymphocytes for resistance to mucosal viral transmission in mice and enhancement of resistance by local administration of IL-12.

    PubMed Central

    Belyakov, I M; Ahlers, J D; Brandwein, B Y; Earl, P; Kelsall, B L; Moss, B; Strober, W; Berzofsky, J A

    1998-01-01

    Although crucial to mucosal vaccine development, the mechanisms of defense against mucosal viral infection are still poorly understood. Protection, cytotoxic T lymphocytes (CTL), and neutralizing antibodies have all been observed, but cause and effect have been difficult to determine. The ability of CTL in the mucosa to mediate protection against mucosal viral transmission has never been proven. Here, we use an HIV peptide immunogen and an HIV-1 gp160-expressing recombinant vaccinia viral intrarectal murine challenge system, in which neutralizing antibodies do not play a role, to demonstrate for the first time that long-lasting immune resistance to mucosal viral transmission can be accomplished by CD8(+) CTL that must be present in the mucosal site of exposure. The resistance is ablated by depleting CD8(+) cells in vivo and requires CTL in the mucosa, whereas systemic (splenic) CTL are shown to be unable to protect against mucosal challenge. Furthermore, the resistance as well as the CTL response can be increased by local mucosal delivery of IL-12 with the vaccine. These results imply that induction of local mucosal CTL may be critical for success of a vaccine against viruses transmitted through a mucosal route, such as HIV. PMID:9854042

  9. Mucoadhesive fenretinide patches for site-specific chemoprevention of oral cancer: enhancement of oral mucosal permeation of fenretinide by coincorporation of propylene glycol and menthol.

    PubMed

    Wu, Xiao; Desai, Kashappa-Goud H; Mallery, Susan R; Holpuch, Andrew S; Phelps, Maynard P; Schwendeman, Steven P

    2012-04-02

    The objective of this study was to enhance oral mucosal permeation of fenretinide by coincorporation of propylene glycol (PG) and menthol in fenretinide/Eudragit RL PO mucoadhesive patches. Fenretinide is an extremely hydrophobic chemopreventive compound with poor tissue permeability. Coincorporation of 5-10 wt % PG (mean J(s) = 16-23 μg cm⁻² h⁻¹; 158-171 μg of fenretinide/g of tissue) or 1-10 wt % PG + 5 wt % menthol (mean J(s) = 18-40 μg cm⁻² h⁻¹; 172-241 μg of fenretinide/g of tissue) in fenretinide/Eudragit RL PO patches led to significant ex vivo fenretinide permeation enhancement (p < 0.001). Addition of PG above 2.5 wt % in the patch resulted in significant cellular swelling in the buccal mucosal tissues. These alterations were ameliorated by combining both enhancers and reducing PG level. After buccal administration of patches in rabbits, in vivo permeation of fenretinide across the oral mucosa was greater (∼43 μg fenretinide/g tissue) from patches that contained optimized permeation enhancer content (2.5 wt % PG + 5 wt % menthol) relative to permeation obtained from enhancer-free patch (∼17 μg fenretinide/g tissue) (p < 0.001). In vitro and in vivo release of fenretinide from patch was not significantly increased by coincorporation of permeation enhancers, indicating that mass transfer across the tissue, and not the patch, largely determined the permeation rate control in vivo. As a result of its improved permeation and its lack of deleterious local effects, the mucoadhesive fenretinide patch coincorporated with 2.5 wt % PG + 5 wt % menthol represents an important step in the further preclinical evaluation of oral site-specific chemoprevention strategies with fenretinide.

  10. Enhancement of Biological Reactions on Cell Surfaces via Macromolecular Crowding

    PubMed Central

    Chapanian, Rafi; Kwan, David H.; Constantinescu, Iren; Shaikh, Fathima A.; Rossi, Nicholas A.A.; Withers, Stephen G.; Kizhakkedathu, Jayachandran N.

    2016-01-01

    The reaction of macromolecules such as enzymes and antibodies with cell surfaces is often an inefficient process, requiring large amounts of expensive reagent. Here we report a general method based on macromolecular crowding with a range of neutral polymers to enhance such reactions, using red blood cells (RBCs) as a model system. Rates of conversion of Type A and B red blood cells to universal O type by removal of antigenic carbohydrates with selective glycosidases are increased up to 400-fold in the presence of crowders. Similar enhancements are seen for antibody binding. We further explore the factors underlying these enhancements using confocal microscopy and fluorescent recovery after bleaching (FRAP) techniques with various fluorescent protein fusion partners. Increased cell-surface concentration due to volume exclusion, along with two-dimensionally confined diffusion of enzymes close to the cell surface, appear to be the major contributing factors. PMID:25140641

  11. Hochuekkito, a Kampo (traditional Japanese herbal) Medicine, Enhances Mucosal IgA Antibody Response in Mice Immunized with Antigen-entrapped Biodegradable Microparticles.

    PubMed

    Matsumoto, Tsukasa; Noguchi, Masaaki; Hayashi, Osamu; Makino, Kimiko; Yamada, Haruki

    2010-03-01

    The effect of oral administration of Hochuekkito (HET; Bu-Zhong-Yi-Qi-Tang in Chinese), a traditional Japanese herbal medicine, on mucosal IgA immune response was investigated. To induce the antigen-specific antibodies in mucosal site, ovalbumin (OVA)-entrapped biodegradable microparticles (OVA-microparticles) were used as an antigen. Mice were orally immunized with OVA-microparticles for 3 successive days with intragastric gavage. From 7 days after the onset of immunization, the mice were boosted twice a week with the same antigen for 2 weeks. HET or water alone was orally administered to the mice via the intragastric route from 7 days before to 27 days after the onset of immunization. Although no significant change in total secretory IgA antibody level was observed in intestinal and nasal washes, OVA-specific IgA titers in intestinal washes were significantly enhanced by oral administration of HET. When lymphocytes from spleen, peripheral blood and Payer's patches were investigated for cytokines production, it was found that the IFN-γ secretion from the lymphocytes was increased by the administration of HET. Microarray analysis of Peyer's patch cells revealed enhanced expression of L-selectin gene. The increase of L-selectin positive cells in B lymphocytes fraction was observed in Peyer's patch cells and peripheral blood mononuclear cells by flow cytometry. These results suggest that the enhanced IFN-γ secretion and increased population of L-selectin positive B lymphocytes by orally administered HET may partly contribute to enhancement of IgA immune response against intestinal antigens, and orally administered HET may strengthen defensive systems against various pathogens and food antigens in intestine.

  12. Reaction enhancement of initially distant scalars by Lagrangian coherent structures

    SciTech Connect

    Pratt, Kenneth R. Crimaldi, John P.; Meiss, James D.

    2015-03-15

    Turbulent fluid flows have long been recognized as a superior means of diluting initial concentrations of scalars due to rapid stirring. Conversely, experiments have shown that the structures responsible for this rapid dilution can also aggregate initially distant reactive scalars and thereby greatly enhance reaction rates. Indeed, chaotic flows not only enhance dilution by shearing and stretching but also organize initially distant scalars along transiently attracting regions in the flow. To show the robustness of this phenomenon, a hierarchical set of three numerical flows is used: the periodic wake downstream of a stationary cylinder, a chaotic double gyre flow, and a chaotic, aperiodic flow consisting of interacting Taylor vortices. We demonstrate that Lagrangian coherent structures (LCS), as identified by ridges in finite time Lyapunov exponents, are directly responsible for this coalescence of reactive scalar filaments. When highly concentrated filaments coalesce, reaction rates can be orders of magnitude greater than would be predicted in a well-mixed system. This is further supported by an idealized, analytical model that was developed to quantify the competing effects of scalar dilution and coalescence. Chaotic flows, known for their ability to efficiently dilute scalars, therefore have the competing effect of organizing initially distant scalars along the LCS at timescales shorter than that required for dilution, resulting in reaction enhancement.

  13. Enhancement of serum and mucosal immune responses to a Haemophilus influenzae Type B vaccine by intranasal delivery.

    PubMed

    Fernandez, Stefan; Cisney, Emily D; Ulrich, Robert G

    2013-11-01

    Intranasal (i.n.) vaccination is potentially the most direct method for conveying upper respiratory and mucosal immunity to respiratory pathogens. However, for unclear reasons, vaccines introduced into the nasal sinuses often have lower efficacy than vaccines administered by the more frequently used parenteral routes. We examined i.n. vaccination in a mouse immune-response model with a commonly used Haemophilus influenzae type B vaccine (Hibv) composed of the polyribosylribitol phosphate (PRP) capsule antigen conjugated to tetanus toxoid. Intranasal vaccination with Hibv using a Toll-like receptor 4 (TLR4) agonist as an adjuvant significantly increased the levels of IgA specific for the PRP capsule antigen in blood serum, saliva, and mucosal secretion specimens. In contrast, control mice vaccinated transdermally (t.d.) with Hibv did not produce significant levels of PRP-specific IgA in the blood serum and saliva, and anti-PRP IgG was increased only in serum. The i.n. and t.d. vaccinations resulted in equivalent bactericidal antibody responses in blood serum, suggesting that vaccine-derived IgG is protective against infection. Elevated levels of IgG specific for the tetanus toxoid carrier protein were measured in nasal sinuses and vaginal secretions in mice vaccinated by either the t.d. or i.n. route. Tissue culture studies confirmed that the nasopharynx-associated lymphoid tissue (NALT) was at least one of the sources of PRP-specific IgA and carrier-specific IgG within the nasal sinuses. We conclude that i.n. vaccination aided by a TLR4 agonist results in robust immune responses to both the carrier protein and bacterial polysaccharide components of the Hibv.

  14. Enhanced Diffusion of Enzymes that Catalyze Exothermic Reactions

    NASA Astrophysics Data System (ADS)

    Golestanian, Ramin

    2015-09-01

    Enzymes have been recently found to exhibit enhanced diffusion due to their catalytic activities. A recent experiment [C. Riedel et al., Nature (London) 517, 227 (2015)] has found evidence that suggests this phenomenon might be controlled by the degree of exothermicity of the catalytic reaction involved. Four mechanisms that can lead to this effect, namely, self-thermophoresis, boost in kinetic energy, stochastic swimming, and collective heating are critically discussed, and it is shown that only the last two can be strong enough to account for the observations. The resulting quantitative description is used to examine the biological significance of the effect.

  15. Sorption enhanced reaction process (SERP) for production of hydrogen

    SciTech Connect

    Sircar, S.; Anand, M.; Carvill, B.

    1995-09-01

    Sorption Enhanced Reaction (SER) is a novel process that is being developed for the production of lower cost hydrogen by steam-methane reforming (SMR). In this process, the reaction of methane with steam is carried out in the presence of an admixture of a catalyst and a selective adsorbent for carbon dioxide. The consequences of SER are: (1) reformation reaction at a significantly lower temperature (300-500{degrees}C) than conventional SMR (800-1100{degrees}C), while achieving the same conversion of methane to hydrogen, (2) the product hydrogen is obtained at reactor pressure (200-400 psig) and at 99+% purity directly from the reactor (compared to only 70-75% H{sub 2} from conventional SMR reactor), (3) downstream hydrogen purification step is either eliminated or significantly reduced in size. The early focus of the program will be on the identification of an adsorbent/chemisorbent for CO{sub 2} and on the demonstration of the SER concept for SMR in our state-of-the-art bench scale process. In the latter stages, a pilot plant will be built to scale-up the technology and to develop engineering data. The program has just been initiated and no significant results for SMR will be reported. However, results demonstrating the basic principles and process schemes of SER technology will be presented for reverse water gas shift reaction as the model reaction. If successful, this technology will be commercialized by Air Products and Chemicals, Inc. (APCI) and used in its existing hydrogen business. APCI is the world leader in merchant hydrogen production for a wide range of industrial applications.

  16. Enhanced reaction rates in NDP analysis with neutron scattering

    SciTech Connect

    Downing, R. Gregory

    2014-04-15

    Neutron depth profiling (NDP) makes accessible quantitative information on a few isotopic concentration profiles ranging from the surface into the sample a few micrometers. Because the candidate analytes for NDP are few, there is little interference encountered. Furthermore, neutrons have no charge so mixed chemical states in the sample are of no direct concern. There are a few nuclides that exhibit large probabilities for neutron scattering. The effect of neutron scattering on NDP measurements has not previously been evaluated as a basis for either enhancing the reaction rates or as a source of measurement error. Hydrogen is a common element exhibiting large neutron scattering probability found in or around sample volumes being analyzed by NDP. A systematic study was conducted to determine the degree of signal change when neutron scattering occurs during analysis. The relative signal perturbation was evaluated for materials of varied neutron scattering probability, concentration, total mass, and geometry. Signal enhancements up to 50% are observed when the hydrogen density is high and in close proximity to the region of analysis with neutron beams of sub thermal energies. Greater signal enhancements for the same neutron number density are reported for thermal neutron beams. Even adhesive tape used to position the sample produces a measureable signal enhancement. Because of the shallow volume, negligible distortion of the NDP measured profile shape is encountered from neutron scattering.

  17. Enhanced reaction rates in NDP analysis with neutron scattering

    NASA Astrophysics Data System (ADS)

    Downing, R. Gregory

    2014-04-01

    Neutron depth profiling (NDP) makes accessible quantitative information on a few isotopic concentration profiles ranging from the surface into the sample a few micrometers. Because the candidate analytes for NDP are few, there is little interference encountered. Furthermore, neutrons have no charge so mixed chemical states in the sample are of no direct concern. There are a few nuclides that exhibit large probabilities for neutron scattering. The effect of neutron scattering on NDP measurements has not previously been evaluated as a basis for either enhancing the reaction rates or as a source of measurement error. Hydrogen is a common element exhibiting large neutron scattering probability found in or around sample volumes being analyzed by NDP. A systematic study was conducted to determine the degree of signal change when neutron scattering occurs during analysis. The relative signal perturbation was evaluated for materials of varied neutron scattering probability, concentration, total mass, and geometry. Signal enhancements up to 50% are observed when the hydrogen density is high and in close proximity to the region of analysis with neutron beams of sub thermal energies. Greater signal enhancements for the same neutron number density are reported for thermal neutron beams. Even adhesive tape used to position the sample produces a measureable signal enhancement. Because of the shallow volume, negligible distortion of the NDP measured profile shape is encountered from neutron scattering.

  18. Enhanced reaction rates in NDP analysis with neutron scattering.

    PubMed

    Downing, R Gregory

    2014-04-01

    Neutron depth profiling (NDP) makes accessible quantitative information on a few isotopic concentration profiles ranging from the surface into the sample a few micrometers. Because the candidate analytes for NDP are few, there is little interference encountered. Furthermore, neutrons have no charge so mixed chemical states in the sample are of no direct concern. There are a few nuclides that exhibit large probabilities for neutron scattering. The effect of neutron scattering on NDP measurements has not previously been evaluated as a basis for either enhancing the reaction rates or as a source of measurement error. Hydrogen is a common element exhibiting large neutron scattering probability found in or around sample volumes being analyzed by NDP. A systematic study was conducted to determine the degree of signal change when neutron scattering occurs during analysis. The relative signal perturbation was evaluated for materials of varied neutron scattering probability, concentration, total mass, and geometry. Signal enhancements up to 50% are observed when the hydrogen density is high and in close proximity to the region of analysis with neutron beams of sub thermal energies. Greater signal enhancements for the same neutron number density are reported for thermal neutron beams. Even adhesive tape used to position the sample produces a measureable signal enhancement. Because of the shallow volume, negligible distortion of the NDP measured profile shape is encountered from neutron scattering.

  19. Biology of HIV Mucosal Transmission

    PubMed Central

    Wu, Li

    2008-01-01

    Purpose of review HIV-1 mucosal transmission plays a critical role in HIV-1 infection and AIDS pathogenesis. This review summarizes the latest advances in biological studies of HIV-1 mucosal transmission, highlighting the implications of these studies in the development of microbicides to prevent HIV-1 transmission. Recent findings New studies of initial HIV-1 infection using improved culture models updated the current view of mucosal transmission. Mechanistic studies enhanced our understanding of cell-cell transmission of HIV-1 mediated by the major target cells, including dendritic cells, CD4+ T cells, and macrophages. Increasing evidence indicated the significance of host factors and immune responses in HIV-1 mucosal infection and transmission. Summary Recent progress in HIV-1 mucosal infection and transmission enriches our knowledge of virus-host interactions and viral pathogenesis. Functional studies of HIV-1 interactions with host cells can provide new insights into the design of more effective approaches to combat HIV-1 infection and AIDS. PMID:18802490

  20. Enhanced Light Scattering of Secondary Organic Aerosols by Multiphase Reactions.

    PubMed

    Li, Kun; Li, Junling; Liggio, John; Wang, Weigang; Ge, Maofa; Liu, Qifan; Guo, Yucong; Tong, Shengrui; Li, Jiangjun; Peng, Chao; Jing, Bo; Wang, Dong; Fu, Pingqing

    2017-02-07

    Secondary organic aerosol (SOA) plays a pivotal role in visibility and radiative forcing, both of which are intrinsically linked to the refractive index (RI). While previous studies have focused on the RI of SOA from traditional formation processes, the effect of multiphase reactions on the RI has not been considered. Here, we investigate the effects of multiphase processes on the RI and light-extinction of m-xylene-derived SOA, a common type of anthropogenic SOA. We find that multiphase reactions in the presence of liquid water lead to the formation of oligomers from intermediate products such as glyoxal and methylglyoxal, resulting in a large enhancement in the RI and light-scattering of this SOA. These reactions will result in increases in light-scattering efficiency and direct radiative forcing of approximately 20%-90%. These findings improve our understanding of SOA optical properties and have significant implications for evaluating the impacts of SOA on the rapid formation of regional haze, global radiative balance, and climate change.

  1. Porous platinum mesoflowers with enhanced activity for methanol oxidation reaction

    SciTech Connect

    Zhuang Lina; Wang Wenjin; Hong Feng; Yang Shengchun; You Hongjun; Fang Jixiang; Ding Bingjun

    2012-07-15

    Porous Pt and Pt-Ag alloy mesoflowers (MFs) with about 2 {mu}m in diameter and high porosity were synthesized using Ag mesoflowers as sacrificial template by galvanic reaction. The silver content in Pt-Ag alloys can be facilely controlled by nitric acid treatment. And the pure Pt MFs can be obtained by selective removal of silver element from Pt{sub 72}Ag{sub 28} MFs electrochemically. Both Pt{sub 45}Ag{sub 55}, Pt{sub 72}Ag{sub 28} and pure Pt show a high catalytic performance in methanol oxidation reaction (MOR). Especially, pure Pt MFs exhibited a 2 to 3 times current density enhancement in MOR compared with the commercial used Pt black, which can be attributed to their porous nanostructure with 3-dimentional nature and small crystal sizes. - Graphical Abstract: The CVs of MOR on Pt (red) and Pt black (green) catalysts in 0.1 M HClO{sub 4} and 0.5 M CH{sub 3}OH for specific mass current. The insert shows the SEM images of two porous Pt MFs. Platinum mesoflowers (MFs) with about 2 {mu}m in diameter and high porosity were synthesised with Ag mesoflowers as sacrificial template by galvanic replacement. The porous Pt MFs exhibited a more than 3 times enhancement in electrocatalytic performance for methanol oxidation reaction compared the commercial used Pt black. Highlights: Black-Right-Pointing-Pointer Porous Pt and Pt-Ag mesoflowers (MFs) were synthesized using Ag MFs sacrifical template. Black-Right-Pointing-Pointer Pt MFs presents an improved catalytic activity in MOR compared with Pt black. Black-Right-Pointing-Pointer We provided a facile approach for the development of high performance Pt electrocatalysts for fuel cells.

  2. Computerized approaches to enhance understanding of organic reaction mechanisms: CAN reaction mechanisms and CPLEX prelaboratory methodology

    NASA Astrophysics Data System (ADS)

    Al-Shammari, Abdulrahman G. Alhamzani

    2008-10-01

    Two approaches to enhance the understanding of organic reaction mechanisms are described. First, a new method for teaching organic reaction mechanisms that can be used in a Computer-Assisted Instruction (CAI) environment is proposed and tested (Chapter 1). The method concentrates upon the important intermediate structures, which are assumed to be on the reaction coordinate, and which can be evaluated and graded by currently available computer techniques. At the same time, the "curved arrows" that show the electron flow in a reaction mechanism are neglected, since they cannot be evaluated and graded with currently available computer techniques. By allowing student practice for learning organic reaction mechanisms using the Curved Arrow Neglect (CAN) method within a "Practice Makes Perfect" CAI method, student performance in the drawing of traditional reaction mechanisms, in which students had to include the "curved arrows" on their written classroom exams, was significantly enhanced. Second, computerized prelaboratory experiments (CPLEX) for organic chemistry laboratory 1 & 2 courses have been created, used, and evaluated (Chapters 2 and 3). These computerized prelabs are unique because they combine both "dry lab" actions with detailed animations of the actual chemistry occurring at the molecular level. The "dry lab" serves to simulate the actual physical manipulations of equipment and chemicals that occur in the laboratory experiment through the use of drag-and-drop computer technology. At the same time, these physical actions are accompanied on a separate part of the computer screen by animations showing the chemistry at the molecular level that is occurring in the experiment. These CPLEX modules were made into Internet accessible modules. The students were allowed to access the CPLEX modules prior to performing the actual laboratory experiment. A detailed evaluation of students' perception of the modules was accomplished via survey methodology during the entire

  3. Multifunctional polyurethane sponge for polymerase chain reaction enhancement.

    PubMed

    Seok, Seunghwan; Shin, Sujeong; Lee, Tae Jae; Jeong, Jae-Min; Yang, MinHo; Kim, Do Hyun; Park, Jung Youn; Lee, Seok Jae; Choi, Bong Gill; Lee, Kyoung G

    2015-03-04

    Selective filtering of target biomaterials from impurities is an important task in DNA amplification through polymerase chain reaction (PCR) enhancement and gene identification to save endangered animals and marine species. Conventional gene extraction methods require complicated steps, skilled persons, and expensive chemicals and instruments to improve DNA amplification. Herein, we proposed an alternative method for overcoming such challenges by imparting secondary functionality using commercially available polyurethane (PU) sponges and cost-effective fabrication approaches through polydopamine and polysiloxane coatings. The porous, highly flexible, and chemically modified superhydrophilic and superhydrophobic PU sponges allow large surface areas and mechanically stable frames for effective extraction of genomic DNA through selective filtering of fish tissues and oils. Furthermore, these chemically modified PU sponges allow separation of genes and improvement of PCR for DNA amplification for the identification of fish species. The combination of a simple fabrication method and functionalized PU sponges could be a useful platform for PCR enhancement and gene-based identification of species for practical applications.

  4. Palliation of radiation-related mucositis

    SciTech Connect

    Rothwell, B.R.; Spektor, W.S.

    1990-01-01

    Oral mucositis associated with head and neck radiotherapy can substantially hinder completion of cancer therapy. Alleviation of this often severe stomatitis can provide enhanced patient comfort and facilitate appropriate care. A double-blind format was used in a pilot project to measure, against a control rinse, the effectiveness of an oral rinse consisting of hydrocortisone, nystatin, tetracycline, and diphenhydramine in controlling radiation-related mucositis. A combination of clinical evaluation and patient responses to a questionnaire was used to judge the results of the topical medications. Patients using the experimental medication developed less mucositis than did patients in the control group.

  5. Sorption enhanced reaction process (SERP) for the production of hydrogen

    SciTech Connect

    Hufton, J.; Mayorga, S.; Gaffney, T.; Nataraj, S.; Rao, M.; Sircar, S.

    1998-08-01

    The novel Sorption Enhanced Reaction Process has the potential to decrease the cost of hydrogen production by steam methane reforming. Current effort for development of this technology has focused on adsorbent development, experimental process concept testing, and process development and design. A preferred CO{sub 2} adsorbent, K{sub 2}CO{sub 3} promoted hydrotalcite, satisfies all of the performance targets and it has been scaled up for process testing. A separate class of adsorbents has been identified which could potentially improve the performance of the H{sub 2}-SER process. Although this material exhibits improved CO{sub 2} adsorption capacity compared to the HTC adsorbent, its hydrothermal stability must be improved. Single-step process experiments (not cyclic) indicate that the H{sub 2}-SER reactor performance during the reaction step improves with decreasing pressure and increasing temperature and steam to methane ratio in the feed. Methane conversion in the H{sub 2}-SER reactor is higher than for a conventional catalyst-only reactor operated at similar temperature and pressure. The reactor effluent gas consists of 90+% H{sub 2}, balance CH{sub 4}, with only trace levels (< 50 ppm) of carbon oxides. A best-case process design (2.5 MMSCFD of 99.9+% H{sub 2}) based on the HTC adsorbent properties and a revised SER process cycle has been generated. Economic analysis of this design indicates the process has the potential to reduce the H{sub 2} product cost by 25--31% compared to conventional steam methane reforming.

  6. Sorption Enhanced Reaction Process (SERP) for production of hydrogen

    SciTech Connect

    Anand, M.; Hufton, J.; Mayorga, S.

    1996-10-01

    Sorption Enhanced Reaction Process (SERP) is a novel process that is being developed for the production of lower cost hydrogen by steam-methane reforming (SMR). In this process the reaction of methane with steam is carried out in the presence of an admixture of a catalyst and a selective adsorbent for carbon dioxide. The key consequences of SERP are: (i) reformation reaction is carried out at a significantly lower temperature (300-500{degrees}C) than that in a conventional SMR reactor (800-1100{degrees}C), while achieving the same conversion of methane to hydrogen, (ii) the product hydrogen is obtained at reactor pressure (200-400 psig) and at 98+% purity directly from the reactor (compared to only 70-75% H{sub 2} from conventional SMR reactor), (iii) downstream hydrogen purification step is either eliminated or significantly reduced in size. The first phase of the program has focused on the development of a sorbent for CO{sub 2} which has (a) reversible CO{sub 2} capacity >0.3 mmol/g at low partial pressures of CO{sub 2} (0.1 - 1.0 atm) in the presence of excess steam (pH{sub 2}O/pCO{sub 2}>20) at 400-500{degrees}C and (b) fast sorption-desorption kinetics for CO{sub 2}, at 400-500{degrees}C. Several families of supported sorbents have been identified that meet the target CO{sub 2} capacity. A few of these sorbents have been tested under repeated sorption/desorption cycles and extended exposure to high pressure steam at 400-500{degrees}C. One sorbent has been scaled up to larger quantities (2-3 kg) and tested in the laboratory process equipment for sorption and desorption kinetics of CO{sub 2}. The CO{sub 2}, sorption and desorption kinetics are desirably fast. This was a critical path item for the first phase of the program and now has been successfully demonstrated. A reactor has been designed that will allow nearly isothermal operation for SERP-SMR. This reactor was integrated into an overall process flow diagram for the SERP-SMR process.

  7. Enhanced Mucosal Defense and Reduced Tumor Burden in Mice with the Compromised Negative Regulator IRAK-M.

    PubMed

    Rothschild, Daniel E; Zhang, Yao; Diao, Na; Lee, Christina K; Chen, Keqiang; Caswell, Clayton C; Slade, Daniel J; Helm, Richard F; LeRoith, Tanya; Li, Liwu; Allen, Irving C

    2017-02-01

    Aberrant inflammation is a hallmark of inflammatory bowel disease (IBD) and colorectal cancer. IRAK-M is a critical negative regulator of TLR signaling and overzealous inflammation. Here we utilize data from human studies and Irak-m(-/-) mice to elucidate the role of IRAK-M in the modulation of gastrointestinal immune system homeostasis. In human patients, IRAK-M expression is up-regulated during IBD and colorectal cancer. Further functional studies in mice revealed that Irak-m(-/-) animals are protected against colitis and colitis associated tumorigenesis. Mechanistically, our data revealed that the gastrointestinal immune system of Irak-m(-/-) mice is highly efficient at eliminating microbial translocation following epithelial barrier damage. This attenuation of pathogenesis is associated with expanded areas of gastrointestinal associated lymphoid tissue (GALT), increased neutrophil migration, and enhanced T-cell recruitment. Further evaluation of Irak-m(-/-) mice revealed a splice variant that robustly activates NF-κB signaling. Together, these data identify IRAK-M as a potential target for future therapeutic intervention.

  8. A study on a dental device for the prevention of mucosal dose enhancement caused by backscatter radiation from dental alloy during external beam radiotherapy.

    PubMed

    Katsura, Kouji; Utsunomiya, Satoru; Abe, Eisuke; Sakai, Hironori; Kushima, Naotaka; Tanabe, Satoshi; Yamada, Takumi; Hayakawa, Takahide; Yamanoi, Yoshihiko; Kimura, Syuhei; Wada, Shinichi; Aoyama, Hidefumi; Hayashi, Takafumi

    2016-11-01

    The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag-Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm(3) of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm(2) using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1-10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.

  9. A study on a dental device for the prevention of mucosal dose enhancement caused by backscatter radiation from dental alloy during external beam radiotherapy

    PubMed Central

    Katsura, Kouji; Utsunomiya, Satoru; Abe, Eisuke; Sakai, Hironori; Kushima, Naotaka; Tanabe, Satoshi; Yamada, Takumi; Hayakawa, Takahide; Yamanoi, Yoshihiko; Kimura, Syuhei; Wada, Shinichi; Aoyama, Hidefumi; Hayashi, Takafumi

    2016-01-01

    The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au–Ag–Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm3 of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm2 using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1–10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose. PMID:27702778

  10. Oral mucositis - self-care

    MedlinePlus

    Cancer treatment - mucositis; Cancer treatment - mouth pain; Cancer treatment - mouth sores; Chemotherapy - mucositis; Chemotherapy - mouth pain; Chemotherapy - mouth sores; Radiation therapy - mucositis; Radiation therapy - mouth pain; Radiation therapy - mouth ...

  11. Why mucosal health?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculture species depend more heavily on mucosal barriers than their terrestrial agricultural counterparts as they are continuously interacting with the aquatic microbiota. Unlike classical immune centers, such as the spleen and kidney, the accessibility of mucosal surfaces through immersion/dip t...

  12. Gastroduodenal Mucosal Defense Mechanisms

    PubMed Central

    Said, Hyder; Kaji, Izumi; Kaunitz, Jonathan D.

    2015-01-01

    Purpose of Review To highlight recent developments in the field of gastroduodenal mucosal defense with emphasis on lumen-gut interactions. Recent Findings There has been a growing interest in the physiological functions of luminal chemosensors present from tongue to colon that detect organic molecules in the luminal content associated with nutrient ingestion, usually associated with specialized cells, in particular the enteroendocrine cells. These receptors transduce the release of peptide hormones, in particular proglucagon-derived products such as the glucagon-like-peptides (GLPs), which have profound effects on gut function and on metabolism. Luminal chemosensors transduce GLP release in response to changes in the cellular environment, as part of the mechanism of nutrient chemosensing. GLP-2 has important trophic effects on the intestinal mucosa, including increasing the proliferation rate of stem cells and reducing transmucosal permeability to ions and small molecules, in addition to increasing the rate of duodenal bicarbonate secretion. GLP-1, although traditionally considered an incretin that enhances the effect of insulin on peripheral tissues, also has trophic effects on the intestinal epithelium. Summary A better understanding of the mechanisms that mediate GLP release can further illuminate the importance of nutrient chemosensing as an important component of the mechanism that mediates the trophic effects of luminal nutrients. GLP-1 and -2 are already in clinical use for the treatment of diabetes and intestinal failure. Improved understanding of the control of their release and their end-organ effects will identify new clinical indications and interventions that enhance their release. PMID:26376476

  13. Radiation Induced Oral Mucositis

    PubMed Central

    PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

  14. Mucosally-directed adrenergic nerves and sympathomimetic drugs enhance non-intimate adherence of Escherichia coli O157:H7 to porcine cecum and colon

    PubMed Central

    Chen, Chunsheng; Lyte, Mark; Stevens, Mark P.; Vulchanova, Lucy; Brown, David R.

    2008-01-01

    The sympathetic neurotransmitter norepinephrine has been found to increase mucosal adherence of enterohemorrhagic Escherichia coli O157:H7 in explants of murine cecum and porcine distal colon. In the present study, we tested the hypothesis that norepinephrine augments the initial, loose adherence of this important pathogen to the intestinal mucosa. In mucosal sheets of porcine cecum or proximal, spiral and distal colon mounted in Ussing chambers, norepinephrine (10 µM, contraluminal addition) increased mucosal adherence of wild-type E. coli O157:H7 strain 85–170; in the cecal mucosa, this effect occurred within 15 – 90 min after bacterial inoculation. In addition, norepinephrine transiently increased short-circuit current in cecal and colonic mucosal sheets, a measure of active anion transport. Norepinephrine was effective in promoting cecal adherence of a non-O157 E. coli strain as well as E. coli O157:H7 eae or espA mutant strains that are incapable of intimate mucosal attachment. Nerve fibers immunoreactive for the norepinephrine synthetic enzyme dopamine β-hydroxylase appeared in close proximity to the cecal epithelium, and the norepinephrine reuptake blocker cocaine, like norepinephrine and the selective α2-adrenoceptor agonist UK-14,304, increased E. coli O157:H7 adherence. These results suggest that norepinephrine, acting upon the large bowel mucosa, modulates early, non-intimate adherence of E. coli O157:H7 and probably other mucosa-associated bacteria. Sympathetic nerves innervating the cecocolonic mucosa may link acute stress exposure or psychostimulant abuse with an increased microbial colonization of the intestinal surface. This in turn may alter host susceptibility to enteric infections. PMID:16687138

  15. Intranasal Mucosal Boosting with an Adenovirus-Vectored Vaccine Markedly Enhances the Protection of BCG-Primed Guinea Pigs against Pulmonary Tuberculosis

    PubMed Central

    Xing, Zhou; McFarland, Christine T.; Sallenave, Jean-Michel; Izzo, Angelo; Wang, Jun; McMurray, David N.

    2009-01-01

    Background Recombinant adenovirus-vectored (Ad) tuberculosis (TB) vaccine platform has demonstrated great potential to be used either as a stand-alone or a boost vaccine in murine models. However, Ad TB vaccine remains to be evaluated in a more relevant and sensitive guinea pig model of pulmonary TB. Many vaccine candidates shown to be effective in murine models have subsequently failed to pass the test in guinea pig models. Methods and Findings Specific pathogen-free guinea pigs were immunized with BCG, AdAg85A intranasally (i.n), AdAg85A intramuscularly (i.m), BCG boosted with AdAg85A i.n, BCG boosted with AdAg85A i.m, or treated only with saline. The animals were then infected by a low-dose aerosol of M. tuberculosis (M.tb). At the specified times, the animals were sacrificed and the levels of infection in the lung and spleen were assessed. In separate studies, the long-term disease outcome of infected animals was monitored until the termination of this study. Immunization with Ad vaccine alone had minimal beneficial effects. Immunization with BCG alone and BCG prime-Ad vaccine boost regimens significantly reduced the level of M.tb infection in the tissues to a similar extent. However, while BCG alone prolonged the survival of infected guinea pigs, the majority of BCG-immunized animals succumbed by 53 weeks post-M.tb challenge. In contrast, intranasal or intramuscular Ad vaccine boosting of BCG-primed animals markedly improved the survival rate with 60% of BCG/Ad i.n- and 40% of BCG/Ad i.m-immunized guinea pigs still surviving by 74 weeks post-aerosol challenge. Conclusions Boosting, particularly via the intranasal mucosal route, with AdAg85A vaccine is able to significantly enhance the long-term survival of BCG-primed guinea pigs following pulmonary M.tb challenge. Our results thus support further evaluation of this viral-vectored TB vaccine in clinical trials. PMID:19516906

  16. Mucosal Health in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract The mucosal surfaces (skin, gill, and intestine) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient absorption, osmoregulation, and waste excretion. Aquaculture specie...

  17. Enhancing Paradynamics for QM/MM Sampling of Enzymatic Reactions.

    PubMed

    Lameira, Jerônimo; Kupchencko, Ilya; Warshel, Arieh

    2016-03-10

    Despite the enormous increase in computer power, it is still extremely challenging to obtain computationally converging sampling of ab initio QM/MM (QM(ai)/MM) free energy surfaces in condensed phases. The sampling problem can be significantly reduced by the use of the reference potential paradynamics (PD) approach, but even this approach still requires major computer time in studies of enzymatic reactions. To further reduce the sampling problem we developed here a new PD version where we use an empirical valence bond reference potential that has a minimum rather than a maximum at the transition state region of the target potential (this is accomplished conveniently by shifting the EVB of the product state). Hence, we can map the TS region in a more efficient way. Here, we introduce and validate the inverted EVB PD approach. The validation involves the study of the S(N)2 step of the reaction catalyzed by haloakene dehalogenase (DhlA) and the GTP hydrolysis in the RasGAP system. In addition, we have also studied the corresponding reaction in water for each of the systems described here and the reaction involving trimethylsulfonium and dimethylamine in solution. The results are encouraging and the new strategy appears to provide a powerful way of evaluating QM(ai)/MM activation free energies.

  18. Experiments concerning the laser-enhanced reaction between vibrationally excited O3 and NO

    NASA Technical Reports Server (NTRS)

    Hui, K.-K.; Cool, T. A.

    1978-01-01

    The enhancement in reaction rate between O3 and NO is studied for the case of O3 vibrationally excited by a CO2 laser. Chemiluminescence observations of a vibrationally excited and an electronically excited nitrogen dioxide reaction product provide information on the separate contributions to the overall reaction rate of these two reactive channels. The contribution of the stretching and bending modes of O3 to the reaction rate enhancement is also discussed. In addition, consideration is given to the nonreactive vibrational deactivation of vibrationally excited O3.

  19. Plasmon-assisted chemical reactions revealed by high-vacuum tip-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Lu, Shuaicheng; Sheng, Shaoxiang; Zhang, Zhenglong; Xu, Hongxing; Zheng, Hairong

    2014-08-01

    Tip-enhanced Raman spectroscopy (TERS) is the technique that combines the nanoscale spatial resolution of a scanning probe microscope and the highly sensitive Raman spectroscopy enhanced by the surface plasmons. It is suitable for chemical analysis at nanometer scale. Recently, TERS exhibited powerful potential in analyzing the chemical reactions at nanoscale. The high sensitivity and spatial resolution of TERS enable us to learn the reaction processes more clearly. More importantly, the chemical reaction in TERS is assisted by surface plasmons, which provides us an optical method to manipulate the chemical reactions at nanoscale. Here using our home-built high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) setup, we successfully observed the plasmon-assisted molecule dimerization and dissociation reactions. In HV-TERS system, under laser illumination, 4-nitrobenzenethiol (4NBT) molecules can be dimerized to p,p'-dimercaptoazobenzene (DMAB), and dissociation reaction occurs for malachite green (MG) molecules. Using our HV-TERS setup, the dynamic processes of the reactions are clearly revealed. The chemical reactions can be manipulated by controlling the plasmon intensity through changing the power of the incident laser, the tunneling current and the bias voltage. We also investigated the role of plasmonic thermal effect in the reactions by measuring both the Stokes and anti- Stokes Raman peaks. Our findings extend the applications of TERS, which can help to study the chemical reactions and understand the dynamic processes at single molecular level, and even design molecules by the plasmon-assisted chemical reactions.

  20. Fluctuation enhanced electrochemical reaction rates at the nanoscale

    PubMed Central

    García-Morales, Vladimir; Krischer, Katharina

    2010-01-01

    The electrode potential constitutes a dynamical variable whenever an electrode is resistively coupled to the electric circuit. We show that at the nanoscale, the discreteness and stochasticity of an electron transfer event causes fluctuations of the electrode potential that render all elementary electrochemical reactions to be faster on a nanoelectrode than predicted by the macroscopic (Butler–Volmer) electrochemical kinetics. This phenomenon is substantiated by means of a generalized (electro)chemical master equation. PMID:20176966

  1. A novel retinoic acid, catechin hydrate and mustard oil-based emulsion for enhanced cytokine and antibody responses against multiple strains of HIV-1 following mucosal and systemic vaccinations

    PubMed Central

    Yu, Mingke; Vajdy, Michael

    2011-01-01

    Non-replicating protein- or DNA-based antigens generally require immune-enhancing adjuvants and delivery systems. It has been particularly difficult to raise antibodies against gp120 of HIV-1, which constitutes an important approach in HIV vaccine design. While almost all effort in adjuvant research has focused on mimicking the pathogens and the danger signals they engender in the host, relatively little effort has been spent on nutritive approaches. In this study, a new nutritive immune-enhancing delivery system (NIDS) composed of vitamin A, a polyphenol-flavonoid catechin hydrate, and mustard oil was tested for its adjuvant effect in immune responses against the gp120 protein of HIV-1CN54. Following a combination of two mucosal and two systemic vaccinations of mice, we found significant enhancement of both local and systemic antibodies as well as cytokine responses. These data have important implications for vaccine and adjuvant design against HIV-1 and other pathogens. PMID:21272602

  2. Enhanced Olefin Cross Metathesis Reactions: The Copper Iodide Effect

    PubMed Central

    Voigtritter, Karl; Ghorai, Subir

    2011-01-01

    Copper iodide has been shown to be an effective co-catalyst for the olefin cross metathesis reaction. In particular, it has both a catalyst stabilizing effect due to iodide ion, as well as copper(I)-based phosphine-scavenging properties that apply to use of the Grubbs-2 catalyst. A variety of Michael acceptors and olefinic partners can be cross-coupled under mild conditions in refluxing diethyl ether that avoid chlorinated solvents. This effect has also been applied to chemistry in water at room temperature using the new surfactant TPGS-750-M. PMID:21528868

  3. Tension-Enhanced Hydrogen Evolution Reaction on Vanadium Disulfide Monolayer.

    PubMed

    Pan, Hui

    2016-12-01

    Water electrolysis is an efficient way for hydrogen production. Finding efficient, cheap, and eco-friendly electrocatalysts is essential to the development of this technology. In the work, we present a first-principles study on the effects of tension on the hydrogen evolution reaction of a novel electrocatalyst, vanadium disulfide (VS2) monolayer. Two electrocatalytic processes, individual and collective processes, are investigated. We show that the catalytic ability of VS2 monolayer at higher hydrogen coverage can be efficiently improved by escalating tension. We find that the individual process is easier to occur in a wide range of hydrogen coverage and the collective process is possible at a certain hydrogen coverage under the same tension. The best hydrogen evolution reaction with near-zero Gibbs free energy can be achieved by tuning tension. We further show that the change of catalytic activity with tension and hydrogen coverage is induced by the change of free carrier density around the Fermi level, that is, higher carrier density, better catalytic performance. It is expected that tension can be a simple way to improve the catalytic activity, leading to the design of novel electrocatalysts for efficient hydrogen production from water electrolysis.

  4. Tension-Enhanced Hydrogen Evolution Reaction on Vanadium Disulfide Monolayer

    NASA Astrophysics Data System (ADS)

    Pan, Hui

    2016-02-01

    Water electrolysis is an efficient way for hydrogen production. Finding efficient, cheap, and eco-friendly electrocatalysts is essential to the development of this technology. In the work, we present a first-principles study on the effects of tension on the hydrogen evolution reaction of a novel electrocatalyst, vanadium disulfide (VS2) monolayer. Two electrocatalytic processes, individual and collective processes, are investigated. We show that the catalytic ability of VS2 monolayer at higher hydrogen coverage can be efficiently improved by escalating tension. We find that the individual process is easier to occur in a wide range of hydrogen coverage and the collective process is possible at a certain hydrogen coverage under the same tension. The best hydrogen evolution reaction with near-zero Gibbs free energy can be achieved by tuning tension. We further show that the change of catalytic activity with tension and hydrogen coverage is induced by the change of free carrier density around the Fermi level, that is, higher carrier density, better catalytic performance. It is expected that tension can be a simple way to improve the catalytic activity, leading to the design of novel electrocatalysts for efficient hydrogen production from water electrolysis.

  5. Organic radicals for the enhancement of oxygen reduction reaction in Li-O2 batteries.

    PubMed

    Tesio, A Y; Blasi, D; Olivares-Marín, M; Ratera, I; Tonti, D; Veciana, J

    2015-12-25

    We examine for the first time the ability of inert carbon free-radicals as soluble redox mediators to catalyze and enhance the oxygen reduction reaction in a (TEGDME)-based electrolyte. We demonstrate that the tris(2,4,6-trichlorophenyl)methyl (TTM) radical is capable of chemically favoring the oxygen reduction reaction improving significantly the Li-O2 battery performance.

  6. Infrared chemiluminescence study of the reaction Cl + HI yielding HCl + I at enhanced collision energies.

    NASA Technical Reports Server (NTRS)

    Cowley, L. T.; Horne, D. S.; Polanyi, J. C.

    1971-01-01

    Performed chemiluminescence and beam experiments show a markedly increased efficiency of conversion of the reaction energy into vibration and a markedly enhanced tendency for forward scattering in the reaction Cl + HI yields HCl + I as compared with H + Cl2 yields HCl + Cl. These differences appear to be due predominantly to the difference in the masses involved.

  7. Aquifer/aquitard interfaces: mixing zones that enhance biogeochemical reactions

    NASA Astrophysics Data System (ADS)

    McMahon, P. B.

    2001-01-01

    Several important biogeochemical reactions are known to occur near the interface between aquifer and aquitard sediments. These reactions include O2 reduction; denitrification; and Fe3+, SO42-, and CO2 (methanogenesis) reduction. In some settings, these reactions occur on the aquitard side of the interface as electron acceptors move from the aquifer into the electron-donor-enriched aquitard. In other settings, these reactions occur on the aquifer side of the interface as electron donors move from the aquitard into the electron-acceptor-enriched, or microorganism-enriched, aquifer. Thus, the aquifer/aquitard interface represents a mixing zone capable of supporting greater microbial activity than either hydrogeologic unit alone. The extent to which biogeochemical reactions proceed in the mixing zone and the width of the mixing zone depend on several factors, including the abundance and solubility of electron acceptors and donors on either side of the interface and the rate at which electron acceptors and donors react and move across the interface. Biogeochemical reactions near the aquifer/aquitard interface can have a substantial influence on the chemistry of water in aquifers and on the chemistry of sediments near the interface. Résumé. Il se produit au voisinage de l'interface entre les aquifères et les imperméables plusieurs réactions biogéochimiques importantes. Il s'agit des réactions de réduction de l'oxygène, de la dénitrification et de la réduction de Fe3+, SO42- et CO2 (méthanogenèse). Dans certaines situations, ces réactions se produisent du côté imperméable de l'interface, avec des accepteurs d'électrons qui vont de l'aquifère vers l'imperméable riche en donneurs d'électrons. Dans d'autres situations, ces réactions se produisent du côté aquifère de l'interface, avec des donneurs d'électrons qui se déplacent de l'imperméable vers l'aquifère riche en accepteurs d'électrons ou en microorganismes. Ainsi, l'interface aquif

  8. A Gallium Oxide-Graphene Oxide Hybrid Composite for Enhanced Photocatalytic Reaction

    PubMed Central

    Kim, Seungdu; Han, Kook In; Lee, In Gyu; Park, Won Kyu; Yoon, Yeojoon; Yoo, Chan Sei; Yang, Woo Seok; Hwang, Wan Sik

    2016-01-01

    Hybrid composites (HCs) made up of gallium oxide (GaO) and graphene oxide (GO) were investigated with the intent of enhancing a photocatalytic reaction under ultraviolet (UV) radiation. The material properties of both GaO and GO were preserved, even after the formation of the HCs. The incorporation of the GO into the GaO significantly enhanced the photocatalytic reaction, as indicated by the amount of methylene blue (MB) degradation. The improvements in the reaction were discussed in terms of increased surface area and the retarded recombination of generated charged carriers. PMID:28335255

  9. Engineering Metallic Nanoparticles for Enhancing and Probing Catalytic Reactions.

    PubMed

    Collins, Gillian; Holmes, Justin D

    2016-07-01

    Recent developments in tailoring the structural and chemical properties of colloidal metal nanoparticles (NPs) have led to significant enhancements in catalyst performance. Controllable colloidal synthesis has also allowed tailor-made NPs to serve as mechanistic probes for catalytic processes. The innovative use of colloidal NPs to gain fundamental insights into catalytic function will be highlighted across a variety of catalytic and electrocatalytic applications. The engineering of future heterogenous catalysts is also moving beyond size, shape and composition considerations. Advancements in understanding structure-property relationships have enabled incorporation of complex features such as tuning surface strain to influence the behavior of catalytic NPs. Exploiting plasmonic properties and altering colloidal surface chemistry through functionalization are also emerging as important areas for rational design of catalytic NPs. This news article will highlight the key developments and challenges to the future design of catalytic NPs.

  10. Fermented milk with probiotic Lactobacillus rhamnosus S1K3 (MTCC5957) protects mice from salmonella by enhancing immune and nonimmune protection mechanisms at intestinal mucosal level.

    PubMed

    Kemgang, Tanedjeu Sonfack; Kapila, Suman; Shanmugam, Venkatesa Perumal; Reddi, Srinu; Kapila, Rajeev

    2016-04-01

    We investigated the mechanism by which an Indian indigenous probiotic culture, Lactobacillus rhamnosus S1K3, could overcome the pathogenic strain Salmonella enterica with an emphasis on the response at the intestinal mucosal level after long-term (30days) consumption. S1K3 was able to produce antimicrobial compounds against the pathogens. The probiotic adhered strongly to intestinal epithelium and maintained its integrity in presence of Salmonella through stimulation of tight junction and antimicrobial peptide genes in vitro. Mice prefed for 30days with S1K3-fermented milk exhibited low incidence of pathogenic Salmonella at mucosal and systemic levels. The probiotic induced TLRs transcripts at the Peyer's patches, followed by an increase in the Secretory-IgA in intestinal fluid, the IgA-secreting cells in lamina propria of small intestine and the IgA level in serum. Moreover, S1K3 maintained the protein level of IL-12, increased the IL-4 and reduced the TGF-β level in intestinal fluid/serum at the later stage of infection. All these actions concurred to lower the count of Salmonella in feces, its invasion in spleen, liver and intestine tissues and improved the health status of probiotic-fed group. In view of this performance, S1K3 appears to be a suitable candidate for the development of nutraceutical food.

  11. Enhanced mucosal immune responses against tetanus toxoid using novel delivery system comprised of chitosan-functionalized gold nanoparticles and botanical adjuvant: characterization, immunogenicity, and stability assessment.

    PubMed

    Barhate, Ganesh; Gautam, Manish; Gairola, Sunil; Jadhav, Suresh; Pokharkar, Varsha

    2014-11-01

    Approaches based on combined use of delivery systems and adjuvants are being favored to maximize efficient mucosal delivery of antigens. Here, we describe a novel delivery system comprised of chitosan-functionalized gold nanoparticles (CsAuNPs) and saponin-containing botanical adjuvant; Asparagus racemosus extract (ARE) for oral delivery of tetanus toxoid (TT). A significant increase in TT-specific IgG (34.53-fold) and IgA (43.75-fold) was observed when TT-CsAuNPs were formulated with ARE (TT-ARE-CsAuNPs). The local IgA immune responses for TT also showed a significant increase (106.5-fold in intestine washes and 99.74-fold in feces) with ARE-based formulations as compared with plain TT group. No effect of ARE was observed on size, charge, and loading properties of CsAuNPs. Additionally, no effect of ARE and CsAuNPs was observed on antigenicity and secondary structure of TT as determined by fluorescence, circular dichroism, and Fourier transform infrared spectroscopy. The stability studies demonstrated excellent stability profile of formulation at recommended storage conditions. The study establishes the possible role of immunomodulatory adjuvants in particulate delivery systems for mucosal delivery of vaccines.

  12. Recombinant cholera toxin B subunit (rCTB) as a mucosal adjuvant enhances induction of diphtheria and tetanus antitoxin antibodies in mice by intranasal administration with diphtheria-pertussis-tetanus (DPT) combination vaccine.

    PubMed

    Isaka, Masanori; Komiya, Takako; Takahashi, Motohide; Yasuda, Yoko; Taniguchi, Tooru; Zhao, Yanqiu; Matano, Keiko; Matsui, Hideyuki; Maeyama, Jun-Ichi; Morokuma, Kazunori; Ohkuma, Kunio; Goto, Norihisa; Tochikubo, Kunio

    2004-08-13

    Recombinant cholera toxin B subunit (rCTB) which is produced by Bacillus brevis carrying pNU212-CTB acts as a mucosal adjuvant capable of enhancing host immune responses specific to unrelated, mucosally co-administered vaccine antigens. When mice were administered intranasally with diphtheria-pertussis-tetanus (DPT) combination vaccine consisting of diphtheria toxoid (DTd), tetanus toxoid (TTd), pertussis toxoid (PTd), and formalin-treated filamentous hemagglutinin (fFHA), the presence of rCTB elevated constantly high values of DTd- and TTd-specific serum ELISA IgG antibody titres, and protective levels of diphtheria and tetanus toxin-neutralizing antibodies but the absence of rCTB did not. Moreover, the addition of rCTB protected all mice against tetanic symptoms and deaths. DPT combination vaccine raised high levels of serum anti-PT IgG antibody titres regardless of rCTB and protected mice from Bordetella pertussis challenge. These results suggest that co-administration of rCTB as an adjuvant is necessary for induction of diphtheria and tetanus antitoxin antibodies on the occasion of intranasal administration of DPT combination vaccine.

  13. Characterization of photosynthetic reaction centers by surface-enhanced resonance Raman scattering

    NASA Astrophysics Data System (ADS)

    Chumanov, George D.; Cotton, Therese M.; Zhou, Chengli; Gaul, Dale; Picorel, Rafael; Seibert, Michael

    1993-06-01

    Surface-enhanced Resonance Raman scattering (SERRS) spectra were obtained for the reaction center complexes of the photosynthetic bacterium Rhodobacter sphaeroides (RC) and from photosystem II (PSII) of spinach, adsorbed on Ag and Au surfaces. These preliminary results demonstrate the considerable potential of this technique for selectively exciting resonance Raman scattering from reaction center components within their distinct absorption bands. Because of the high sensitivity afforded by SERRS, spectra could be measured from a single monolayer of reaction centers adsorbed on a metal surface. The surface-sensitivity provides new information indicating the topology of the PSII reaction center 47 kD light-harvesting protein complex. The activity of the PSII reaction center complex adsorbed on metal surfaces was monitored by photochemical reduction of cyt b-559. Measurement of fluorescence emission was shown to be a new and sensitive method for monitoring the structural and functional integrity of the PSII reaction center complex on the metal surface.

  14. Oral immunization with recombinant hepatitis E virus antigen displayed on the Lactococcus lactis surface enhances ORF2-specific mucosal and systemic immune responses in mice.

    PubMed

    Gao, Shenyang; Li, Dandan; Liu, Ying; Zha, Enhui; Zhou, Tiezhong; Yue, Xiqing

    2015-01-01

    Hepatitis E virus (HEV) as a recognized zoonotic pathogen has posed global burden on public health, which is exacerbated by lack of efficient vaccine. In this study, we constructed a recombinant (inaQ-ORF2 gene fusion) Lactococcus lactis (L. lactis) strain NZ3900 that expresses and displays the hepatitis E virus antigen ORF2 utilizing an ice uncleation protein-based anchor system. After oral vaccination of BALB/c mice, significantly higher levels of ORF2-specific mucosal IgA and serum IgG were detected and cellular immunity was also induced. These findings further support that L. lactis-based HEV antigen vaccines could be used for human and animal protection against infection.

  15. Dermatologic Reactions to Targeted Therapy: A Focus on Epidermal Growth Factor Receptor Inhibitors and Nursing Care.

    PubMed

    Barton-Burke, Margaret; Ciccolini, Kathryn; Mekas, Maria; Burke, Sean

    2017-03-01

    Cancer treatments usually have side effects of bone marrow depression, mucositis, hair loss, and gastrointestinal issues. Rarely do we think of skin side effects until patients have been treated successfully with epidermal growth factor receptor inhibitors (EGFRi). Those reactions include papulopustular rash, hair changes, radiation dermatitis enhancement, pruritus, mucositis, xerosis, fissures, and paronychia. This article discusses the common skin reactions seen when using EGFRi and presents an overview of skin as the largest and important organ of the body, including an overview of skin assessment, pathophysiology of the skin reactions, nursing care involved, and introduction to oncodermatology.

  16. Mucosal melanoma: an update.

    PubMed

    Ballester Sánchez, R; de Unamuno Bustos, B; Navarro Mira, M; Botella Estrada, R

    2015-03-01

    Mucosal melanoma is a rare melanoma subtype that differs from the cutaneous form of the tumor in its biology, clinical manifestations, and management. Diagnosis is usually late due to a lack of early or specific signs and the location of lesions in areas that are difficult to access on physical examination. Surgical excision is the treatment of choice for localized disease. The value of sentinel lymph node biopsy and lymphadenectomy is still unclear. Radiotherapy can be used as adjuvant therapy for the control of local disease. c-KIT mutations are more common than in other types of melanoma and this has led to significant advances in the use of imatinib for the treatment of metastatic mucosal melanoma.

  17. Cathodic current enhancement via manganese and oxygen related reactions in marine biofilms

    NASA Astrophysics Data System (ADS)

    Strom, Matthew James

    Corrosion is a threat that has economic, and environmental impacts worldwide. Many types of corrosive attack are the subject of ongoing research. One of these areas of research is microbiologically influenced corrosion, which is the enhancement and/or initiation of corrosion events caused by microorganisms. It is well known that colonies of microorganisms can enhance cathodic currents through biofilm formation. The aim of the present work was to elucidate the role of manganese in enhancing cathodic currents in the presence of biofilms. Repeated polarizations conducted in Delaware Bay waters, on biofilm coated Cr identified potentially sustainable reduction reactions. The reduction of MnO2 and the enhancement of the oxygen reduction reaction (ORR) were proven to be factors that influence cathodic current enhancement. The removal of ambient oxygen during polarizations resulted in a shutdown of cathodic current enhancement. These field data led to an exploration of the synergistic relationship between MnO2 and the ORR. Laboratory studies of the catalysis of peroxide disproportionation by MnO2 were monitored using a hanging mercury drop electrode. Experiments were run at an ambient sweater pH of 8 and pH 9, which simulated the near-surface conditions typical of cathodes immersed in seawater. Rapid reoxidation at the more basic pH was shown to allow manganese to behave as a persistent catalyst under the typical electrochemical surface conditions of a cathode. As a result a mechanism for ORR enhancement by manganese was proposed as a unique mechanism for cathodic current enhancement in biofilms. A separate field study of Delaware biofilms on stainless steel coupled to a sacrificial Al anode was carried out to identify the ORR enhancement mechanism and sustainable redox reactions at the cathode. Chemical treatments of glutaraldehyde and formaldoxime were applied to cathodes with biofilms to distinguish between enzymatic and MnO2 related ORR enhancement. The results ruled

  18. Nucleosome linker proteins HMGB1 and histone H1 differentially enhance DNA ligation reactions.

    PubMed

    Yamanaka, Shiho; Katayama, Eisaku; Yoshioka, Ken-ichi; Nagaki, Sumiko; Yoshida, Michiteru; Teraoka, Hirobumi

    2002-03-22

    We previously reported that HMGB1, which originally binds to chromatin in a manner competitive with linker histone H1 to modulate chromatin structure, enhances both intra-molecular and inter-molecular ligations. In this paper, we found that histone H1 differentially enhances ligation reaction of DNA double-strand breaks (DSB). Histone H1 stimulated exclusively inter-molecular ligation reaction of DSB with DNA ligase IIIbeta and IV, whereas HMGB1 enhanced mainly intra-molecular ligation reaction. Electron microscopy of direct DNA-protein interaction without chemical cross-linking visualized that HMGB1 bends and loops linear DNA to form compact DNA structure and that histone H1 is capable of assembling DNA in tandem arrangement with occasional branches. These results suggest that differences in the enhancement of DNA ligation reaction are due to those in alteration of DNA configuration induced by these two linker proteins. HMGB1 and histone H1 may function in non-homologous end-joining of DSB repair and V(D)J recombination in different manners.

  19. Hydrocarbon-water-rock interaction: Redox reaction as a mechanism for sandstone reservoir porosity enhancement

    SciTech Connect

    Shebl, M.A.; Surdam, R.C.

    1995-06-01

    Experiments evaluated the potential for and extent of oil-water-rock reactions in hydrocarbon reservoirs. Results indicate not only that significant potential exists for redox reactions between oxidized mineral phases and crude oil, but that such reactions can significantly alter porosity and permeability characteristics of an elastic hydrocarbon reservoir. The red (oxidized) sandstones used in the redox experiment initially contained 10 to 25% carbonate, anhydrite, and intergranular clay cements. Porosity ranged from 6 to 15%. The sandstones were gray or white after experimentation, and porosity increased 12 to 20% over original values, primarily due to carbonate dissolution. It is suggested that during the redox experiments, the iron oxides ({+-} sulphate) were reduced and hydrocarbon was oxidized to produce oxygenated organic compounds (e.g., organic acid anions, CO{sub 2}). These redox reaction products destabilized the carbonate cements and enhanced sandstone porosity. It is concluded that redox reactions involving crude oil and the mineral matrix of these reservoir rocks in the presence of H{sub 2}O do occur and may result in significantly enhanced porosity. Hydrocarbon emplacement and the resultant redox reactions can cause bleaching and changes in porosity and permeability. This relationship is well documented in the Wingate, White Rim, and Tensleep sandstones. The hydrocarbon reservoir units are white to gray and have good porosity and permeability. The adjacent non-reservoir units are red (due to hematite staining), and have good carbonate cementation and poor porosity and permeability, confining hydrocarbon flow to the nearby reservoir units or associated fractures.

  20. Enhanced mucosal immunoglobulin A response and solid protection against foot-and-mouth disease virus challenge induced by a novel dendrimeric peptide.

    PubMed

    Cubillos, Carolina; de la Torre, Beatriz G; Jakab, Annamaria; Clementi, Giorgia; Borrás, Eva; Bárcena, Juan; Andreu, David; Sobrino, Francisco; Blanco, Esther

    2008-07-01

    The successful use of a dendrimeric peptide to protect pigs against challenge with foot-and-mouth disease virus (FMDV), which causes the most devastating animal disease worldwide, is described. Animals were immunized intramuscularly with a peptide containing one copy of a FMDV T-cell epitope and branching out into four copies of a B-cell epitope. The four immunized pigs did not develop significant clinical signs upon FMDV challenge, neither systemic nor mucosal FMDV replication, nor was its transmission to contact control pigs observed. The dendrimeric construction specifically induced high titers of FMDV-neutralizing antibodies and activated FMDV-specific T cells. Interestingly, a potent anti-FMDV immunoglobulin A response (local and systemic) was observed, despite the parenteral administration of the peptide. On the other hand, peptide-immunized animals showed no antibodies specific of FMDV infection, which qualifies the peptide as a potential marker vaccine. Overall, the dendrimeric peptide used elicited an immune response comparable to that found for control FMDV-infected pigs that correlated with a solid protection against FMDV challenge. Dendrimeric designs of this type may hold substantial promise for peptide subunit vaccine development.

  1. Mucosal adaptation to aspirin induced gastric damage in humans. Studies on blood flow, gastric mucosal growth, and neutrophil activation.

    PubMed Central

    Konturek, J W; Dembinski, A; Stoll, R; Domschke, W; Konturek, S J

    1994-01-01

    The gastropathy associated with the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin is a common side effect of this class of drugs, but the precise mechanisms by which they cause mucosal damage have not been fully explained. During continued use of an injurious substance, such as aspirin, the extent of gastric mucosal damage decreases and this phenomenon is named gastric adaptation. To assess the extent of mucosal damage by aspirin and subsequent adaptation the effects of 14 days of continuous, oral administration of aspirin (2 g per day) to eight healthy male volunteers was studied. To estimate the rate of mucosal damage, gastroscopy was performed before (day 0) and at days 3, 7, 14 of aspirin treatment. Gastric microbleeding and gastric mucosal blood flow were measured using laser Doppler flowmeter and mucosal biopsy specimens were taken for the estimation of tissue DNA synthesis and RNA and DNA concentration. In addition, the activation of neutrophils in peripheral blood was assessed by measuring their ability to associate with platelets. Aspirin induced acute damage mainly in gastric corpus, reaching at day 3 about 3.5 on the endoscopic Lanza score but lessened to about 1.5 at day 14 pointing to the occurrence of gastric adaptation. Mucosal blood flow increased at day 3 by about 50% in the gastric corpus and by 88% in the antrum. The in vitro DNA synthesis and RNA concentration, an index of mucosal growth, were reduced at day 3 but then increased to reach about 150% of initial value at the end of aspirin treatment. It is concluded that the treatment with aspirin in humans induces gastric adaptation to this agent, which entails the increase in mucosal blood flow, the rise in neutrophil activation, and the enhancement in mucosal growth. PMID:7959223

  2. Enhanced reactivity for hydrogen reactions at Pt nanoislands on Au(111).

    PubMed

    Wolfschmidt, Holger; Weingarth, Daniel; Stimming, Ulrich

    2010-05-17

    We report high exchange current densities exceeding 1 A cm(-2) at Pt nanostructures on Au(111) for hydrogen-related reactions. Such activity is found at Pt nanoparticles with a coverage of less than 10 % of a monolayer on Au(111) and on single Pt particles deposited on Au(111). Potential pulse technique as well as micropolarization curves with overpotentials of +/-10 mV were used in the case of extended nanostructured surfaces to determine the activity. Single Pt particles were investigated in an in situ electrochemical scanning tunneling microscope setup using the STM tip as local sensor. The reactivity obtained on Pt nanostructured Au(111) towards hydrogen reactions were subsidized by single particle reactivity measurements. The specific activity of platinum is enhanced by more than a factor of 1000 as compared to a Pt(111) single crystal. Aspects that may explain this enhancement such as an involvement of the substrate, highly reactive defect sites and enhanced mass transport are discussed.

  3. Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

    SciTech Connect

    Ham, Hyung Chul; Hwang, Gyeong S.; Manogaran, Dhivya; Lee, Kang Hee; Jin, Seon-ah; You, Dae Jong; Pak, Chanho; Kwon, Kyungjung

    2013-11-28

    Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd{sub 3}Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd{sub 3}Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts.

  4. Humoral immune responses among mucosal and cutaneous leishmaniasis patients caused by Leishmania braziliensis.

    PubMed

    Valli, L C; Passos, V M; Dietze, R; Callahan, H L; Berman, J D; Grogl, M

    1999-12-01

    Mucosal leishmaniasis is arguably the most morbid sequelae of cutaneous leishmaniasis. The importance of early diagnosis for effective therapy, coupled with the difficulty of diagnosing the disease parasitologically, prompted this investigation of humoral immune markers of mucosal disease. Promastigote soluble antigens of Leishmania braziliensis, isolated from cutaneous and mucosal lesions, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis; antigens were identified by immunoblotting with parasite-specific IgG antibody-positive sera of patients with mucosal disease (n = 18) and cutaneous disease (n = 23). For antigens of the cutaneous parasite WR 2095, mucosal sera generally reacted intensely to antigens of 75, 66, and 45 kDa and weakly to 48-50-kDa antigens, whereas cutaneous sera generally detected weakly the first 3 antigens and intensely the latter doublet. The data suggest that the transition from the cutaneous antigenic profile to a mucosal antigenic profile could be used to predict mucosal disease in approximately half of mucosal patients. An additional finding was that antibodies present in the sera of patients with mucosal disease labeled a 66-kDa peptide of normal human lip mucosa more intensely than did cutaneous sera. Autoimmune processes stimulated by the reaction of IgG, originally directed against the 66-kDa of L. braziliensis, to the 66-kDa antigen of mucosal tissue may contribute to the clinical presentation of mucosal leishmaniasis.

  5. [Mucositis in head and neck cancer patients undergoing radiochemotherapy].

    PubMed

    Santos, Renata Cristina Schmidt; Dias, Rodrigo Souza; Giordani, Adelmo José; Segreto, Roberto Araújo; Segreto, Helena Regina Comodo

    2011-12-01

    The objective of present study was to classify oral mucositis according to the Common Toxicity Criterion (CTC) international parameters in head and neck tumor patients simultaneously treated with radio and chemotherapy, and characterize a patient profile in our area, observing the individuals' habits, tumor characteristics, treatment protocol and acute reaction intensity. Fifty patients undergoing simultaneous 66 to 70 Gy megavoltage radiotherapy and cisplatin/carboplatin chemotherapy were evaluated in this study. Weekly evaluations of the degree of mucositis were perfoemed according to CTC, a four-degree ordinal scale; 36% of all patients and 100% of those with diabetes discontinued treatment due to mucositis, showing that this pathology contributes to the severity of mucositis.

  6. Lactobacilli and Bifidobacteria enhance mucosal B cell responses and differentially modulate systemic antibody responses to an oral human rotavirus vaccine in a neonatal gnotobiotic pig disease model.

    PubMed

    Kandasamy, Sukumar; Chattha, Kuldeep S; Vlasova, Anastasia N; Rajashekara, Gireesh; Saif, Linda J

    2014-01-01

    B cells play a key role in generation of protective immunity against rotavirus infection, a major cause of gastroenteritis in children. Current RV vaccines are less effective in developing countries compared to developed countries. Commensals/probiotics influence mucosal immunity, but the role of early gut colonizing bacteria in modulating intestinal B cell responses to RV vaccines is largely unknown. We co-colonized neonatal gnotobiotic pigs, the only animal model susceptible to HRV diarrhea, with 2 dominant bacterial species present in the gut of breastfed infants, Lactobacillus rhamnosus strain GG and Bifidobacterium animalis lactis Bb12 to evaluate their impact on B cell responses to an attenuated (Att) human rotavirus (HRV) Wa strain vaccine. Following HRV challenge, probiotic-colonized, AttHRV vaccinated piglets had significantly lower fecal scores and reduced HRV shedding titers compared to uncolonized, AttHRV vaccinated pigs. The reduction in HRV diarrhea was significantly correlated with higher intestinal IgA HRV antibody titers and intestinal HRV-specific IgA antibody secreting cell (ASC) numbers in probiotic-colonized, AttHRV vaccinated pigs compared to uncolonized, vaccinated pigs. The significantly higher small intestinal HRV IgA antibody responses coincided with higher IL-6, IL-10 and APRIL responses of ileal mononuclear cells (MNCs) and the immunomodulatory effects of probiotics genomic DNA on TGF-β and IL-10 responses. However, serum RV IgG antibody titers and total IgG titers were significantly lower in probiotic-colonized, AttHRV vaccinated pigs compared to uncolonized, vaccinated pigs, both pre- and post-challenge. In summary, LGG and Bb12 beneficially modulated intestinal B cell responses to HRV vaccine.

  7. Lactobacilli and Bifidobacteria enhance mucosal B cell responses and differentially modulate systemic antibody responses to an oral human rotavirus vaccine in a neonatal gnotobiotic pig disease model

    PubMed Central

    Kandasamy, Sukumar; Chattha, Kuldeep S; Vlasova, Anastasia N; Rajashekara, Gireesh; Saif, Linda J

    2014-01-01

    B cells play a key role in generation of protective immunity against rotavirus infection, a major cause of gastroenteritis in children. Current RV vaccines are less effective in developing countries compared to developed countries. Commensals/probiotics influence mucosal immunity, but the role of early gut colonizing bacteria in modulating intestinal B cell responses to RV vaccines is largely unknown. We co-colonized neonatal gnotobiotic pigs, the only animal model susceptible to HRV diarrhea, with 2 dominant bacterial species present in the gut of breastfed infants, Lactobacillus rhamnosus strain GG and Bifidobacterium animalis lactis Bb12 to evaluate their impact on B cell responses to an attenuated (Att) human rotavirus (HRV) Wa strain vaccine. Following HRV challenge, probiotic-colonized, AttHRV vaccinated piglets had significantly lower fecal scores and reduced HRV shedding titers compared to uncolonized, AttHRV vaccinated pigs. The reduction in HRV diarrhea was significantly correlated with higher intestinal IgA HRV antibody titers and intestinal HRV-specific IgA antibody secreting cell (ASC) numbers in probiotic-colonized, AttHRV vaccinated pigs compared to uncolonized, vaccinated pigs. The significantly higher small intestinal HRV IgA antibody responses coincided with higher IL-6, IL-10 and APRIL responses of ileal mononuclear cells (MNCs) and the immunomodulatory effects of probiotics genomic DNA on TGF-β and IL-10 responses. However, serum RV IgG antibody titers and total IgG titers were significantly lower in probiotic-colonized, AttHRV vaccinated pigs compared to uncolonized, vaccinated pigs, both pre- and post-challenge. In summary, LGG and Bb12 beneficially modulated intestinal B cell responses to HRV vaccine. PMID:25483333

  8. Trehalose enhances osmotic tolerance and suppresses lysophosphatidylcholine-induced acrosome reaction in ram spermatozoon.

    PubMed

    Ahmad, E; Naseer, Z; Aksoy, M; Küçük, N; Uçan, U; Serin, I; Ceylan, A

    2015-09-01

    This study was aimed to investigate the influence of trehalose on osmotic tolerance and the ability of ram spermatozoon to undergo acrosome reaction induced by lysophosphatidylcholine (LPC). In experiment 1, the diluted ejaculates were exposed to anisosmotic fructose solutions (70, 500, 750 and 1000 mOsm l(-1) ) with or without 50 mm trehalose. The presence of trehalose in hyperosmotic conditions enhanced (P < 0.05) the percentage of live, live-intact and intact spermatozoa. Similarly, trehalose enhanced (P < 0.05) the live and live-intact spermatozoa during hypo-osmotic conditions. In experiment 2, the centrifuged ejaculates were diluted with TCG only or TCG containing either 50 or 100 mm trehalose. The acrosome reaction was induced by LPC. The percentage of acrosome-reacted spermatozoon was less (P < 0.05) in trehalose-supplemented groups compared to control. In experiment 3, the ejaculates were cryopreserved in an extender containing 0 mm (control), 50 mm or 100 mm trehalose. Supplementation of extender with trehalose, either 50 mm or 100 mm, enhanced the cryosurvival rate (P < 0.05) compared to the control. In conclusion, the presence of trehalose in anisosmotic conditions enhances the osmotic tolerance, cryosurvival rate of ram spermatozoon and suppresses their ability to undergo LPC and cryo-induced acrosome reaction.

  9. Modeling of Sheath Ion-Molecule Reactions in Plasma Enhanced Chemical Vapor Deposition of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Hash, David B.; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    In many plasma simulations, ion-molecule reactions are modeled using ion energy independent reaction rate coefficients that are taken from low temperature selected-ion flow tube experiments. Only exothermic or nearly thermoneutral reactions are considered. This is appropriate for plasma applications such as high-density plasma sources in which sheaths are collisionless and ion temperatures 111 the bulk p!asma do not deviate significantly from the gas temperature. However, for applications at high pressure and large sheath voltages, this assumption does not hold as the sheaths are collisional and ions gain significant energy in the sheaths from Joule heating. Ion temperatures and thus reaction rates vary significantly across the discharge, and endothermic reactions become important in the sheaths. One such application is plasma enhanced chemical vapor deposition of carbon nanotubes in which dc discharges are struck at pressures between 1-20 Torr with applied voltages in the range of 500-700 V. The present work investigates The importance of the inclusion of ion energy dependent ion-molecule reaction rates and the role of collision induced dissociation in generating radicals from the feedstock used in carbon nanotube growth.

  10. Dynamics and Kinetics Study of "In-Water" Chemical Reactions by Enhanced Sampling of Reactive Trajectories.

    PubMed

    Zhang, Jun; Yang, Y Isaac; Yang, Lijiang; Gao, Yi Qin

    2015-11-12

    High potential energy barriers and engagement of solvent coordinates set challenges for in silico studies of chemical reactions, and one is quite commonly limited to study reactions along predefined reaction coordinate(s). A systematic protocol, QM/MM MD simulations using enhanced sampling of reactive trajectories (ESoRT), is established to quantitatively study chemical transitions in complex systems. A number of trajectories for Claisen rearrangement in water and toluene were collected and analyzed, respectively. Evidence was found that the bond making and breaking during this reaction are concerted processes in solutions, preferentially through a chairlike configuration. Water plays an important dynamic role that helps stabilize the transition sate, and the dipole-dipole interaction between water and the solute also lowers the transition barrier. The calculated rate coefficient is consistent with the experimental measurement. Compared with water, the reaction pathway in toluene is "narrower" and the reaction rate is slower by almost three orders of magnitude due to the absence of proper interactions to stabilize the transition state. This study suggests that the "in-water" nature of the Claisen rearrangement in aqueous solution influences its thermodynamics, kinetics, as well as dynamics.

  11. Organizing a mucosal defense.

    PubMed

    Newberry, Rodney D; Lorenz, Robin G

    2005-08-01

    Gastrointestinal associated lymphoid tissue can be divided into loosely organized effector sites, which include the lamina propria and intraepithelial lymphocytes, and more organized structures, such as mesenteric lymph nodes (LNs), Peyer's patches (PPs), isolated lymphoid follicles, and cryptopatches (CPs). These organized structures in the gastrointestinal tract have been hypothesized to play the role of primary lymphoid organ, supporting the extrathymic development of T lymphocytes (CPs), secondary lymphoid organs involved in the induction of the mucosal immune response (PPs), and tertiary lymphoid structures whose function is still under debate (isolated lymphoid follicles). The most widely studied lymphoid structure found in the small intestine is the PP. PPs are secondary lymphoid structures, and their development and function have been extensively investigated. However, single lymphoid aggregates resembling PPs have been also described in humans and in the murine small intestines. These isolated lymphoid follicles have both germinal centers and an overlying follicle-associated epithelium, suggesting that they also can function as inductive sites for the mucosal immune response. This review compares and contrasts the development and function of the four main organized gastrointestinal lymphoid tissues: CPs, isolated lymphoid follicles, PPs, and mesenteric LNs.

  12. Intranasal Immunization with DOTAP Cationic Liposomes Combined with DC-Cholesterol Induces Potent Antigen-Specific Mucosal and Systemic Immune Responses in Mice

    PubMed Central

    Iwase, Naoko; Takahashi, Saeko; Yamakita, Yuki; Iwata, Tomoko; Muto, Shoko; Sato, Emi; Takayama, Noriko; Honjo, Emi; Kiyono, Hiroshi; Kunisawa, Jun; Aramaki, Yukihiko

    2015-01-01

    Despite the progress made by modern medicine, infectious diseases remain one of the most important threats to human health. Vaccination against pathogens is one of the primary methods used to prevent and treat infectious diseases that cause illness and death. Vaccines administered by the mucosal route are potentially a promising strategy to combat infectious diseases since mucosal surfaces are a major route of entry for most pathogens. However, this route of vaccination is not widely used in the clinic due to the lack of a safe and effective mucosal adjuvant. Therefore, the development of safe and effective mucosal adjuvants is key to preventing infectious diseases by enabling the use of mucosal vaccines in the clinic. In this study, we show that intranasal administration of a cationic liposome composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl] (DC-chol) (DOTAP/DC-chol liposome) has a potent mucosal adjuvant effect in mice. Intranasal vaccination with ovalbumin (OVA) in combination with DOTAP/DC-chol liposomes induced the production of OVA-specific IgA in nasal tissues and increased serum IgG1 levels, suggesting that the cationic DOTAP/DC-chol liposome leads to the induction of a Th2 immune response. Additionally, nasal-associated lymphoid tissue and splenocytes from mice treated with OVA plus DOTAP/DC-chol liposome showed high levels of IL–4 expression. DOTAP/DC-chol liposomes also enhanced OVA uptake by CD11c+ dendritic cells in nasal-associated lymphoid tissue. These data demonstrate that DOTAP/DC-chol liposomes elicit immune responses via an antigen-specific Th2 reaction. These results suggest that cationic liposomes merit further development as a mucosal adjuvant for vaccination against infectious diseases. PMID:26440657

  13. Intranasal Immunization with DOTAP Cationic Liposomes Combined with DC-Cholesterol Induces Potent Antigen-Specific Mucosal and Systemic Immune Responses in Mice.

    PubMed

    Tada, Rui; Hidaka, Akira; Iwase, Naoko; Takahashi, Saeko; Yamakita, Yuki; Iwata, Tomoko; Muto, Shoko; Sato, Emi; Takayama, Noriko; Honjo, Emi; Kiyono, Hiroshi; Kunisawa, Jun; Aramaki, Yukihiko

    2015-01-01

    Despite the progress made by modern medicine, infectious diseases remain one of the most important threats to human health. Vaccination against pathogens is one of the primary methods used to prevent and treat infectious diseases that cause illness and death. Vaccines administered by the mucosal route are potentially a promising strategy to combat infectious diseases since mucosal surfaces are a major route of entry for most pathogens. However, this route of vaccination is not widely used in the clinic due to the lack of a safe and effective mucosal adjuvant. Therefore, the development of safe and effective mucosal adjuvants is key to preventing infectious diseases by enabling the use of mucosal vaccines in the clinic. In this study, we show that intranasal administration of a cationic liposome composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl] (DC-chol) (DOTAP/DC-chol liposome) has a potent mucosal adjuvant effect in mice. Intranasal vaccination with ovalbumin (OVA) in combination with DOTAP/DC-chol liposomes induced the production of OVA-specific IgA in nasal tissues and increased serum IgG1 levels, suggesting that the cationic DOTAP/DC-chol liposome leads to the induction of a Th2 immune response. Additionally, nasal-associated lymphoid tissue and splenocytes from mice treated with OVA plus DOTAP/DC-chol liposome showed high levels of IL-4 expression. DOTAP/DC-chol liposomes also enhanced OVA uptake by CD11c+ dendritic cells in nasal-associated lymphoid tissue. These data demonstrate that DOTAP/DC-chol liposomes elicit immune responses via an antigen-specific Th2 reaction. These results suggest that cationic liposomes merit further development as a mucosal adjuvant for vaccination against infectious diseases.

  14. Enzyme immunoassay by dynamic enhanced vibrational spectroscopy of the enzyme reaction product

    NASA Astrophysics Data System (ADS)

    Zhao, Haiying; Dou, Xiaoming

    2005-01-01

    This paper reports a kind of application of surface-enhanced Raman scattering (SERS) to immunology. In the proposed system, antibody immobilized on a solid substrate reacts with antigen, which binds with another antibody labeled with peroxidase. If this immunocomplex is subjected to reaction with o-phenylenediamine and hydrogenperoxide at 37°C, azoaniline is generated. This azo compound is adsorbed on a silver colloid and only the azo compound gives a strong surface-enhanced resonance Raman (SERRS) spectrum. A linear relationship was observed between the peak intensity of the N=N stretching band and the concentration of antigen, revealing that one can determine the concentration of antigen by the SERRS measurement of the reaction product.

  15. Alleviating mucositis: are we on track for a novel therapeutic?

    PubMed

    Lalla, Rajesh V

    2015-02-01

    Oral and gastrointestinal mucositis has emerged as an important toxicity of cancer therapy. In addition to supportive care measures, agents for the prevention or treatment of mucositis in specific patient populations are described in the evidence-based clinical practice guidelines published by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology. However, there still remains an unmet clinical need for preventive and therapeutic agents in several patient populations. The successful development of such agents will rely on our improved understanding of the pathogenic mechanisms underlying mucositis. Studies are also underway on novel delivery mechanisms and risk prediction models that can facilitate the selective use of interventions for mucositis in a targeted and cost-effective manner. A large number of agents are at various stages in the clinical development pipeline. Enhanced management of this dose-limiting toxicity will allow the delivery of optimal cancer therapy and improve patient prognosis.

  16. Field Effect Enhanced Hydrogen Evolution Reaction of MoS2 Nanosheets.

    PubMed

    Wang, Junhui; Yan, Mengyu; Zhao, Kangning; Liao, Xiaobin; Wang, Peiyao; Pan, Xuelei; Yang, Wei; Mai, Liqiang

    2017-02-01

    Hydrogen evolution reaction performance of MoS2 can be enhanced through electric-field-facilitated electron transport. The best catalytic performance of a MoS2 nanosheet can achieve an overpotential of 38 mV (100 mA cm(-2) ) at gate voltage of 5 V, the strategy of utilizing the electric field can be used in other semiconductor materials to improve their electrochemical catalysis for future relevant research.

  17. Probing Redox Reactions at the Nanoscale with Electrochemical Tip-Enhanced Raman Spectroscopy

    DTIC Science & Technology

    2015-11-18

    Probing Redox Reactions at the Nanoscale with Electrochemical Tip- Enhanced Raman Spectroscopy Dmitry Kurouski,† Michael Mattei,† and Richard P. Van...Information ABSTRACT: A fundamental understanding of electrochem - ical processes at the nanoscale is crucial to solving problems in research areas as...TERS) uniquely offers subnanometer spatial resolution and single-molecule sensitivity, making it the ideal tool for studying nanoscale electrochemical

  18. Mucosal biofilms of Candida albicans.

    PubMed

    Ganguly, Shantanu; Mitchell, Aaron P

    2011-08-01

    Biofilms are microbial communities that form on surfaces and are embedded in an extracellular matrix. C. albicans forms pathogenic mucosal biofilms that are evoked by changes in host immunity or mucosal ecology. Mucosal surfaces are inhabited by many microbial species; hence these biofilms are polymicrobial. Several recent studies have applied paradigms of biofilm analysis to study mucosal C. albicans infections. These studies reveal that the Bcr1 transcription factor is a master regulator of C. albicans biofilm formation under diverse conditions, though the most relevant Bcr1 target genes can vary with the biofilm niche. An important determinant of mucosal biofilm formation is the interaction with host defenses. Finally, studies of interactions between bacterial species and C. albicans provide insight into the communication mechanisms that endow polymicrobial biofilms with unique properties.

  19. [Structural characteristics of infrared spectra for polyaluminum chloride in enhanced reactions of modification].

    PubMed

    Zhou, Feng-shan; Wang, Shi-hu; Su, Jin-zhu; Sun, Hu; Ding, Jie; Xu, Yi-zhuang; Wu, Jin-guang

    2004-05-01

    As an important preparation method of Inorganic Polymer Flocculants (IPFs) with all-round performance, the use of enhanced reactions of modification for Polyaluminum Chlorides (PAC) is a trend of application. In this paper, auctorial-made multicore oligomers as a complexing agent, polysilicate as a crosslinking agent and polyacrylamide as a compounding agent are respectively used to enhance PAC and prepared three kinds of IPFs, named CO-PAC, CR-PAC and PAM-PAC. The Fourier Transform Infrared spectra (FTIR) of the three flocculants show that there have been found new chemical bonds beyond Al-OH in their structures, and each characteristic band of primary group in PAC has a band shift to a lower frequency due to its structural aberration. These evidences suggested that enhanced reactions of modification for PAC are not at all a simple process of physical mix, but a chemical reaction to form other structural characteristics of inorganic polymers. The excellent coagulation behavior of these new flocculants depends mainly on the chemical actions, but there are a little physical effects between the modifiers and PAC.

  20. Risk analysis, diagnosis and management of gastrointestinal mucositis in pediatric cancer patients.

    PubMed

    Kuiken, Nicoline S S; Rings, Edmond H H M; Tissing, Wim J E

    2015-04-01

    Mucositis is a complex inflammatory reaction of the mucous membranes of the alimentary tract upon chemotherapy and radiotherapy treatment in oncology patients. Mucositis can be subdivided in oral and gastrointestinal mucositis (GI mucositis). The damage to the gastrointestinal tract compromises the intestinal function and thereby the nutritional status and the quality of life, and eventually affects survival. The literature on GI mucositis focuses mainly on adults. This review focuses on data available on GI mucositis in pediatric cancer patients. An evaluation of the clinical presentation and consequences of GI mucositis in children is outlined. The review summarizes key issues for clinicians with respect to risk analysis for developing mucositis and the diagnosis of this condition in children. Information on these issues is obtained from clinical trials in children and adults, and from animal models. Diagnostic tools and assessment of severity of GI mucositis in children is elaborated on. Furthermore, the clinical management of the symptoms and consequences of GI mucositis in children, with specific focus on nutritional support, are discussed.

  1. Oral lichen planus and lichenoid mucositis.

    PubMed

    De Rossi, Scott S; Ciarrocca, Katharine

    2014-04-01

    Oral lichen planus (OLP) is commonly found in middle-aged women. Although the cause is unknown, research points to several complex immunologic events and cells that are responsible for the inflammatory destruction and chronicity of these lesions. Biopsy for histologic diagnosis is recommended. The mainstay of treatment remains topical corticosteroids; however, newer therapies such as immunomodulating agents are available for recalcitrant lesions. In cases of lichenoid mucositis or reactions, treatment should be directed at identifying and removing the presumed cause. Given the apparent risk of squamous cell carcinoma in these patients, frequent follow-up and repeat biopsy are vital.

  2. An Overview of Challenges Limiting the Design of Protective Mucosal Vaccines for Finfish

    PubMed Central

    Munang’andu, Hetron Mweemba; Mutoloki, Stephen; Evensen, Øystein

    2015-01-01

    Research in mucosal vaccination in finfish has gained prominence in the last decade in pursuit of mucosal vaccines that would lengthen the duration of protective immunity in vaccinated fish. However, injectable vaccines have continued to dominate in the vaccination of finfish because they are perceived to be more protective than mucosal vaccines. Therefore, it has become important to identify the factors that limit developing protective mucosal vaccines in finfish as an overture to identifying key areas that require optimization in mucosal vaccine design. Some of the factors that limit the success for designing protective mucosal vaccines for finfish identified in this review include the lack optimized protective antigen doses for mucosal vaccines, absence of immunostimulants able to enhance the performance of non-replicative mucosal vaccines, reduction of systemic antibodies due to prolonged exposure to oral vaccination and the lack of predefined correlates of protective immunity for use in the optimization of newly developed mucosal vaccines. This review also points out the need to develop prime-boost vaccination regimes able to induce long-term protective immunity in vaccinated fish. By overcoming some of the obstacles identified herein, it is anticipated that future mucosal vaccines shall be designed to induce long-term protective immunity in finfish. PMID:26557121

  3. Near-Infrared Plasmonic-Enhanced Solar Energy Harvest for Highly Efficient Photocatalytic Reactions.

    PubMed

    Cui, Jiabin; Li, Yongjia; Liu, Lei; Chen, Lin; Xu, Jun; Ma, Jingwen; Fang, Gang; Zhu, Enbo; Wu, Hao; Zhao, Lixia; Wang, Leyu; Huang, Yu

    2015-10-14

    We report a highly efficient photocatalyst comprised of Cu7S4@Pd heteronanostructures with plasmonic absorption in the near-infrared (NIR)-range. Our results indicated that the strong NIR plasmonic absorption of Cu7S4@Pd facilitated hot carrier transfer from Cu7S4 to Pd, which subsequently promoted the catalytic reactions on Pd metallic surface. We confirmed such enhancement mechanism could effectively boost the sunlight utilization in a wide range of photocatalytic reactions, including the Suzuki coupling reaction, hydrogenation of nitrobenzene, and oxidation of benzyl alcohol. Even under irradiation at 1500 nm with low power density (0.45 W/cm(2)), these heteronanostructures demonstrated excellent catalytic activities. Under solar illumination with power density as low as 40 mW/cm(2), nearly 80-100% of conversion was achieved within 2 h for all three types of organic reactions. Furthermore, recycling experiments showed the Cu7S4@Pd were stable and could retain their structures and high activity after five cycles. The reported synthetic protocol can be easily extended to other Cu7S4@M (M = Pt, Ag, Au) catalysts, offering a new solution to design and fabricate highly effective photocatalysts with broad material choices for efficient conversion of solar energy to chemical energy in an environmentally friendly manner.

  4. Mucosal Targeting of a BoNT/A Subunit Vaccine Adjuvanted with a Mast Cell Activator Enhances Induction of BoNT/A Neutralizing Antibodies in Rabbits

    PubMed Central

    Staats, Herman F.; Fielhauer, Jeffrey R.; Thompson, Afton L.; Tripp, Alice A.; Sobel, Ashley E.; Maddaloni, Massimo; Abraham, Soman N.; Pascual, David W.

    2011-01-01

    Background We previously reported that the immunogenicity of Hcβtre, a botulinum neurotoxin A (BoNT/A) immunogen, was enhanced by fusion to an epithelial cell binding domain, Ad2F, when nasally delivered to mice with cholera toxin (CT). This study was performed to determine if Ad2F would enhance the nasal immunogenicity of Hcβtre in rabbits, an animal model with a nasal cavity anatomy similar to humans. Since CT is not safe for human use, we also tested the adjuvant activity of compound 48/80 (C48/80), a mast cell activating compound previously determined to safely exhibit nasal adjuvant activity in mice. Methods New Zealand White or Dutch Belted rabbits were nasally immunized with Hcβtre or Hcβtre-Ad2F alone or combined with CT or C48/80, and serum samples were tested for the presence of Hcβtre-specific binding (ELISA) or BoNT/A neutralizing antibodies. Results Hcβtre-Ad2F nasally administered with CT induced serum anti-Hcβtre IgG ELISA and BoNT/A neutralizing antibody titers greater than those induced by Hcβtre + CT. C48/80 provided significant nasal adjuvant activity and induced BoNT/A-neutralizing antibodies similar to those induced by CT. Conclusions Ad2F enhanced the nasal immunogenicity of Hcβtre, and the mast cell activator C48/80 was an effective adjuvant for nasal immunization in rabbits, an animal model with a nasal cavity anatomy similar to that in humans. PMID:21304600

  5. Bimodal and trimodal multisensory enhancement: effects of stimulus onset and intensity on reaction time.

    PubMed

    Diederich, Adele; Colonius, Hans

    2004-11-01

    Manual reaction times to visual, auditory, and tactile stimuli presented simultaneously, or with a delay, were measured to test for multisensory interaction effects in a simple detection task with redundant signals. Responses to trimodal stimulus combinations were faster than those to bimodal combinations, which in turn were faster than reactions to unimodal stimuli. Response enhancement increased with decreasing auditory and tactile stimulus intensity and was a U-shaped function of stimulus onset asynchrony. Distribution inequality tests indicated that the multisensory interaction effects were larger than predicted by separate activation models, including the difference between bimodal and trimodal response facilitation. The results are discussed with respect to previous findings in a focused attention task and are compared with multisensory integration rules observed in bimodal and trimodal superior colliculus neurons in the cat and monkey.

  6. Process for the oxidation of materials in water at supercritical temperatures utilizing reaction rate enhancers

    SciTech Connect

    Swallow, K.C.; Killilea, W.R.; Hong, G.T.; Bourhis, A.L.

    1993-08-03

    A method is described for substantially completely oxidizing combustible materials in which an aqueous stream bearing the combustible materials is reacted in the presence of an oxidant comprising diatomic oxygen and at a temperature greater than the critical temperature of water and at a pressure greater than about 25 bar, within a reactor for a period of less than about 5 minutes to produce a reaction product stream, wherein the reaction is initiated in the presence of a rate enhancer comprising at least one oxidizing agent in addition to said oxidant selected from the group consisting of ozone, hydrogen peroxide, salts containing persulfate, salts containing permanganate, nitric acid, salts containing nitrate, oxyacids of chlorine and their corresponding salts, hypochlorous acid, salts containing hypochlorite, chlorous acid, salts containing chlorite, chloric acid, salts containing chlorate, perchloric acid, and salts containing perchlorate.

  7. Bifidobacterium bifidum OLB6378 Simultaneously Enhances Systemic and Mucosal Humoral Immunity in Low Birth Weight Infants: A Non-Randomized Study

    PubMed Central

    Tanaka, Katsunori; Tsukahara, Takamitsu; Yanagi, Takahide; Nakahara, Sayuri; Furukawa, Ouki; Tsutsui, Hidemi; Koshida, Shigeki

    2017-01-01

    Probiotic supplementation has been part of the discussion on methods to enhance humoral immunity. Administration of Bifidobacterium bifidum OLB6378 (OLB6378) reduced the incidence of late-onset sepsis in infants. In this non-randomized study, we aimed to determine the effect of administration of live OLB6378 on infants’ humoral immunity. Secondly, we tried to elucidate whether similar effects would be observed with administration of non-live OLB6378. Low birth weight (LBW) infants weighing 1500–2500 g were divided into three groups: Group N (no intervention), Group L (administered live OLB6378 concentrate), and Group H (administered non-live OLB6378 concentrate). The interventions were started within 48 h after birth and continued until six months of age. Serum immunoglobulin G (IgG) levels (IgG at one month/IgG at birth) were significantly higher in Group L than in Group N (p < 0.01). Group H exhibited significantly higher serum IgG levels (p < 0.01) at one month of age and significantly higher intestinal secretory immunoglobulin A (SIgA) levels (p < 0.05) at one and two months of age than Group N. No difference was observed in the mortality or morbidity between groups. Thus, OLB6378 administration in LBW infants enhanced humoral immunity, and non-live OLB6378, which is more useful as a food ingredient, showed a more marked effect than the viable bacteria. PMID:28245626

  8. Antimicrobial agent, tetracycline, enhanced upper alimentary tract Candida albicans infection and its related mucosal proliferation in alloxan-induced diabetic rats.

    PubMed

    Sano, Tomoya; Ozaki, Kiyokazu; Kodama, Yasushi; Matsuura, Tetsuro; Narama, Isao

    2012-10-01

    Alloxan-induced diabetic rats showed proliferative changes in the forestomach, accompanied by chronic inflammation, and one lesion progress to squamous cell carcinoma (SCC) without distant metastasis. The authors demonstrated that these lesions might be caused by Candida albicans infection. Antimicrobial therapy, particularly tetracycline treatment, has been blamed for a reduction in the number of competing bacterial organisms, which is frequently mentioned as a cause of candidiasis. The objective of this study is to ascertain whether or not tetracycline treatment can accelerate early-onset of C. albicans infection and the proliferative changes in this diabetic model. Alloxan-induced diabetic rats were given chlorinated water (AL group) and tetracycline solution (0.1% during week 1 and 0.01% thereafter) as drinking water (AT group). They were sacrificed after 25 weeks of drinking the treated water. The infection rate with C. albicans in the AT group was significantly higher than in the AL group. The incidence and severity of the squamous cell hyperplasia were enhanced in the AT group compared to the AL group. The proliferative lesions were consistently accompanied by inflammation and C. albicans infection in both groups. SCC was detected in one case in the AT group. These findings demonstrate that tetracycline induces C. albicans infection and enhances forestomach proliferative lesions in alloxan-induced diabetic rats.

  9. Energetic composite and system with enhanced mechanical sensitivity to initiation of self-sustained reaction

    DOEpatents

    Gash, Alexander E [Brentwood, CA; Barbee, Jr., Troy W.

    2012-05-29

    An energetic composition and system using amassed energetic multilayer pieces which are formed from the division, such as for example by cutting, scoring, breaking, crushing, shearing, etc., of a mechanically activatable monolithic energetic multilayer(s) (e.g. macro-scale sheets of multilayer films), for enhancing the sensitivity of the energetic composite and system to mechanical initiation of self-sustained reaction. In particular, mechanical initiation of the energetic composition may be achieved with significantly lower mechanical energy inputs than that typically required for initiating the monolithic energetic multilayers from which it is derived.

  10. Deep Sub-Barrier Fusion Enhancement in the {sup 6}He+{sup 206}Pb Reaction

    SciTech Connect

    Penionzhkevich, Yu.E.; Zagrebaev, V.I.; Lukyanov, S.M.; Kalpakchieva, R.

    2006-04-28

    The fusion of {sup 6}He with {sup 206}Pb has been studied at energies close to and below the Coulomb barrier. The experiment was carried out at the Dubna Radioactive Ion Beams complex of FLNR, JINR. The {sup 6}He beam intensity was about 5x10{sup 6} pps, the maximum energy being 60.3{+-}0.4 MeV. The yield of the {sup 210}Po isotope, produced in the 2n-evaporation channel, demonstrates an extremely large enhancement of the sub-barrier fusion cross section as compared with the {sup 4}He+{sup 208}Pb reaction. This enhancement is most likely due to the mechanism of 'sequential fusion' with an intermediate neutron transfer from {sup 6}He to the Pb nucleus with positive Q values.

  11. Enhancement Effect of Noble Metals on Manganese Oxide for the Oxygen Evolution Reaction.

    PubMed

    Seitz, Linsey C; Hersbach, Thomas J P; Nordlund, Dennis; Jaramillo, Thomas F

    2015-10-15

    Developing improved catalysts for the oxygen evolution reaction (OER) is key to the advancement of a number of renewable energy technologies, including solar fuels production and metal air batteries. In this study, we employ electrochemical methods and synchrotron techniques to systematically investigate interactions between metal oxides and noble metals that lead to enhanced OER catalysis for water oxidation. In particular, we synthesize porous MnOx films together with nanoparticles of Au, Pd, Pt, or Ag and observe significant improvement in activity for the combined catalysts. Soft X-ray absorption spectroscopy (XAS) shows that increased activity correlates with increased Mn oxidation states to 4+ under OER conditions compared to bare MnOx, which exhibits minimal OER current and remains in a 3+ oxidation state. Thickness studies of bare MnOx films and of MnOx films deposited on Au nanoparticles reveal trends suggesting that the enhancement in activity arises from interfacial sites between Au and MnOx.

  12. Significant enhancement of the Stille reaction with a new combination of reagents-copper(I) iodide with cesium fluoride.

    PubMed

    Mee, Simon P H; Lee, Victor; Baldwin, Jack E

    2005-05-20

    The combination of copper(I) iodide and cesium fluoride significantly enhances the Stille reaction. After extensive optimisation, a variety of electronically unfavourable and sterically hindered substrates were coupled in very high yields under mild conditions.

  13. Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

    NASA Astrophysics Data System (ADS)

    Giuffrida, L.; Margarone, D.; Cirrone, G. A. P.; Picciotto, A.; Cuttone, G.; Korn, G.

    2016-10-01

    We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [Yoon et al. Applied Physics Letters 105, 223507 (2014)], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

  14. Plasmonic photocatalytic reactions enhanced by hot electrons in a one-dimensional quantum well

    SciTech Connect

    Huang, H. J. E-mail: hhjhuangkimo@gmail.com; Liu, B. H.; Lin, C. T.; Su, W. S.

    2015-11-15

    The plasmonic endothermic oxidation of ammonium ions in a spinning disk reactor resulted in light energy transformation through quantum hot charge carriers (QHC), or quantum hot electrons, during a chemical reaction. It is demonstrated with a simple model that light of various intensities enhance the chemical oxidization of ammonium ions in water. It was further observed that light illumination, which induces the formation of plasmons on a platinum (Pt) thin film, provided higher processing efficiency compared with the reaction on a bare glass disk. These induced plasmons generate quantum hot electrons with increasing momentum and energy in the one-dimensional quantum well of a Pt thin film. The energy carried by the quantum hot electrons provided the energy needed to catalyze the chemical reaction. The results indicate that one-dimensional confinement in spherical coordinates (i.e., nanoparticles) is not necessary to provide an extra excited state for QHC generation; an 8 nm Pt thin film for one-dimensional confinement in Cartesian coordinates can also provide the extra excited state for the generation of QHC.

  15. Plasmonic photocatalytic reactions enhanced by hot electrons in a one-dimensional quantum well

    NASA Astrophysics Data System (ADS)

    Huang, H. J.; Liu, B.-H.; Lin, C.-T.; Su, W. S.

    2015-11-01

    The plasmonic endothermic oxidation of ammonium ions in a spinning disk reactor resulted in light energy transformation through quantum hot charge carriers (QHC), or quantum hot electrons, during a chemical reaction. It is demonstrated with a simple model that light of various intensities enhance the chemical oxidization of ammonium ions in water. It was further observed that light illumination, which induces the formation of plasmons on a platinum (Pt) thin film, provided higher processing efficiency compared with the reaction on a bare glass disk. These induced plasmons generate quantum hot electrons with increasing momentum and energy in the one-dimensional quantum well of a Pt thin film. The energy carried by the quantum hot electrons provided the energy needed to catalyze the chemical reaction. The results indicate that one-dimensional confinement in spherical coordinates (i.e., nanoparticles) is not necessary to provide an extra excited state for QHC generation; an 8 nm Pt thin film for one-dimensional confinement in Cartesian coordinates can also provide the extra excited state for the generation of QHC.

  16. Amorphous nickel boride membrane on a platinum-nickel alloy surface for enhanced oxygen reduction reaction

    NASA Astrophysics Data System (ADS)

    He, Daping; Zhang, Libo; He, Dongsheng; Zhou, Gang; Lin, Yue; Deng, Zhaoxiang; Hong, Xun; Wu, Yuen; Chen, Chen; Li, Yadong

    2016-08-01

    The low activity of the oxygen reduction reaction in polymer electrolyte membrane fuel cells is a major barrier for electrocatalysis, and hence needs to be optimized. Tuning the surface electronic structure of platinum-based bimetallic alloys, a promising oxygen reduction reaction catalyst, plays a key role in controlling its interaction with reactants, and thus affects the efficiency. Here we report that a dealloying process can be utilized to experimentally fabricate the interface between dealloyed platinum-nickel alloy and amorphous nickel boride membrane. The coating membrane works as an electron acceptor to tune the surface electronic structure of the platinum-nickel catalyst, and this composite catalyst composed of crystalline platinum-nickel covered by amorphous nickel boride achieves a 27-times enhancement in mass activity relative to commercial platinum/carbon at 0.9 V for the oxygen reduction reaction performance. Moreover, this interactional effect between a crystalline surface and amorphous membrane can be readily generalized to facilitate the 3-times higher catalytic activity of commercial platinum/carbon.

  17. Amorphous nickel boride membrane on a platinum–nickel alloy surface for enhanced oxygen reduction reaction

    PubMed Central

    He, Daping; Zhang, Libo; He, Dongsheng; Zhou, Gang; Lin, Yue; Deng, Zhaoxiang; Hong, Xun; Wu, Yuen; Chen, Chen; Li, Yadong

    2016-01-01

    The low activity of the oxygen reduction reaction in polymer electrolyte membrane fuel cells is a major barrier for electrocatalysis, and hence needs to be optimized. Tuning the surface electronic structure of platinum-based bimetallic alloys, a promising oxygen reduction reaction catalyst, plays a key role in controlling its interaction with reactants, and thus affects the efficiency. Here we report that a dealloying process can be utilized to experimentally fabricate the interface between dealloyed platinum–nickel alloy and amorphous nickel boride membrane. The coating membrane works as an electron acceptor to tune the surface electronic structure of the platinum–nickel catalyst, and this composite catalyst composed of crystalline platinum–nickel covered by amorphous nickel boride achieves a 27-times enhancement in mass activity relative to commercial platinum/carbon at 0.9 V for the oxygen reduction reaction performance. Moreover, this interactional effect between a crystalline surface and amorphous membrane can be readily generalized to facilitate the 3-times higher catalytic activity of commercial platinum/carbon. PMID:27503412

  18. Immunomodulation by mucosal gene transfer using TGF-beta DNA.

    PubMed Central

    Kuklin, N A; Daheshia, M; Chun, S; Rouse, B T

    1998-01-01

    This report evaluates the efficacy of DNA encoding TGF-beta administered mucosally to suppress immunity and modulate the immunoinflammatory response to herpes simplex virus (HSV) infection. A single intranasal administration of an eukaryotic expression vector encoding TGF-beta1 led to expression in the lung and lymphoid tissue. T cell-mediated immune responses to HSV infection were suppressed with this effect persisting as measured by the delayed-type hypersensitivity reaction for at least 7 wk. Treated animals were more susceptible to systemic infection with HSV. Multiple prophylactic mucosal administrations of TGF-beta DNA also suppressed the severity of ocular lesions caused by HSV infection, although no effects on this immunoinflammatory response were evident after therapeutic treatment with TGF-beta DNA. Our results demonstrate that the direct mucosal gene transfer of immunomodulatory cytokines provides a convenient means of modulating immunity and influencing the expression of inflammatory disorders. PMID:9664086

  19. Intervertebral reaction force prediction using an enhanced assembly of OpenSim models.

    PubMed

    Senteler, Marco; Weisse, Bernhard; Rothenfluh, Dominique A; Snedeker, Jess G

    2016-01-01

    OpenSim offers a valuable approach to investigating otherwise difficult to assess yet important biomechanical parameters such as joint reaction forces. Although the range of available models in the public repository is continually increasing, there currently exists no OpenSim model for the computation of intervertebral joint reactions during flexion and lifting tasks. The current work combines and improves elements of existing models to develop an enhanced model of the upper body and lumbar spine. Models of the upper body with extremities, neck and head were combined with an improved version of a lumbar spine from the model repository. Translational motion was enabled for each lumbar vertebrae with six controllable degrees of freedom. Motion segment stiffness was implemented at lumbar levels and mass properties were assigned throughout the model. Moreover, body coordinate frames of the spine were modified to allow straightforward variation of sagittal alignment and to simplify interpretation of results. Evaluation of model predictions for level L1-L2, L3-L4 and L4-L5 in various postures of forward flexion and moderate lifting (8 kg) revealed an agreement within 10% to experimental studies and model-based computational analyses. However, in an extended posture or during lifting of heavier loads (20 kg), computed joint reactions differed substantially from reported in vivo measures using instrumented implants. We conclude that agreement between the model and available experimental data was good in view of limitations of both the model and the validation datasets. The presented model is useful in that it permits computation of realistic lumbar spine joint reaction forces during flexion and moderate lifting tasks. The model and corresponding documentation are now available in the online OpenSim repository.

  20. Enhancement of oxygen reduction reaction activities by Pt nanoclusters decorated on ordered mesoporous porphyrinic carbons

    SciTech Connect

    Sun-Mi Hwang; Choi, YongMan; Kim, Min Gyu; Sohn, Young-Jun; Cheon, Jae Yeong; Joo, Sang Hoon; Yim, Sung-Dae; Kuttiyiel, Kurian A.; Sasaki, Kotaro; Adzic, Radoslav R.; Park, Gu-Gon

    2016-03-08

    The high cost of Pt-based membrane electrode assemblies (MEAs) is a critical hurdle for the commercialization of polymer electrolyte fuel cells (PEFCs). Recently, non-precious metal-based catalysts (NPMCs) have demonstrated much enhanced activity but their oxygen reduction reaction (ORR) activity is still inferior to that of Pt-based catalysts resulting in a much thicker electrode in the MEA. For the reduction of mass transport and ohmic overpotential we adopted a new concept of catalyst that combines an ultra-low amount of Pt nanoclusters with metal–nitrogen (M–Nx) doped ordered mesoporous porphyrinic carbon (FeCo–OMPC(L)). The 5 wt% Pt/FeCo–OMPC(L) showed a 2-fold enhancement in activities compared to a higher loading of Pt. Our experimental results supported by first-principles calculations indicate that a trace amount of Pt nanoclusters on FeCo–OMPC(L) significantly enhances the ORR activity due to their electronic effect as well as geometric effect from the reduced active sites. Finally, in terms of fuel cell commercialization, this class of catalysts is a promising candidate due to the limited use of Pt in the MEA.

  1. Enhancement of oxygen reduction reaction activities by Pt nanoclusters decorated on ordered mesoporous porphyrinic carbons

    DOE PAGES

    Sun-Mi Hwang; Choi, YongMan; Kim, Min Gyu; ...

    2016-03-08

    The high cost of Pt-based membrane electrode assemblies (MEAs) is a critical hurdle for the commercialization of polymer electrolyte fuel cells (PEFCs). Recently, non-precious metal-based catalysts (NPMCs) have demonstrated much enhanced activity but their oxygen reduction reaction (ORR) activity is still inferior to that of Pt-based catalysts resulting in a much thicker electrode in the MEA. For the reduction of mass transport and ohmic overpotential we adopted a new concept of catalyst that combines an ultra-low amount of Pt nanoclusters with metal–nitrogen (M–Nx) doped ordered mesoporous porphyrinic carbon (FeCo–OMPC(L)). The 5 wt% Pt/FeCo–OMPC(L) showed a 2-fold enhancement in activities comparedmore » to a higher loading of Pt. Our experimental results supported by first-principles calculations indicate that a trace amount of Pt nanoclusters on FeCo–OMPC(L) significantly enhances the ORR activity due to their electronic effect as well as geometric effect from the reduced active sites. Finally, in terms of fuel cell commercialization, this class of catalysts is a promising candidate due to the limited use of Pt in the MEA.« less

  2. Exploration of the Role of Heat Activation in Enhancing Serpentine Carbon Sequestration Reactions

    SciTech Connect

    McKelvy, M.J.; Chizmeshya, A.V.G.; Diefenbacher, J.; Bearat, H.; Wolf, G.

    2005-03-29

    As compared with other candidate carbon sequestration technologies, mineral carbonation offers the unique advantage of permanent disposal via geologically stable and environmentally benign carbonates. The primary challenge is the development of an economically viable process. Enhancing feedstock carbonation reactivity is key. Heat activation dramatically enhances aqueous serpentine carbonation reactivity. Although the present process is too expensive to implement, the materials characteristics and mechanisms that enhance carbonation are of keen interest for further reducing cost. Simultaneous thermogravimetric and differential thermal analysis (TGA/DTA) of the serpentine mineral lizardite was used to isolate a series of heat-activated materials as a function of residual hydroxide content at progressively higher temperatures. Their structure and composition are evaluated via TGA/DTA, X-ray powder diffraction (including phase analysis), and infrared analysis. The meta-serpentine materials that were observed to form ranged from those with longer range ordering, consistent with diffuse stage-2 like interlamellar order, to an amorphous component that preferentially forms at higher temperatures. The aqueous carbonation reaction process was investigated for representative materials via in situ synchrotron X-ray diffraction. Magnesite was observed to form directly at 15 MPa CO{sub 2} and at temperatures ranging from 100 to 125 C. Carbonation reactivity is generally correlated with the extent of meta-serpentine formation and structural disorder.

  3. Reaction enhancement in an unsteady obstacle wake: Implications for broadcast spawning and other mixing-limited processes in marine environments

    NASA Astrophysics Data System (ADS)

    Crimaldi, J. P.; Kawakami, T. R.

    2015-03-01

    Structured wakes behind flow obstacles are shown to be regions that enhance mixing and reactions between initially distant scalars, with implications for a wide range of mixing-limited biogeochemical processes in marine systems (e.g., broadcast spawning, phytoplankton-nutrient interactions). Reaction of initially distant reactive scalars in the structured laminar wake of a round obstacle is quantified using direct numerical simulations of the 2D Navier-Stokes and reactive transport equations with Reynolds number of 100 and Schmidt number of 1. Scalars are released upstream of the obstacle, initially separated by ambient fluid that acts as a barrier to mixing and reaction. Reaction is computed using second-order kinetics in the low-Damkholer limit. Reaction enhancement is quantified by comparing the obstacle-wake reactions to those in a similar flow but without the obstacle. Integrated reaction rates are shown to be orders of magnitude larger in the obstacle wake for cases with significant initial separation between the scalars. The role of unsteady processes in the reaction enhancement is also investigated by quantifying the scalar covariance in different regions of the wake.

  4. Complex dynamics and enhanced photosensitivity in a modified Belousov-Zhabotinsky reaction

    NASA Astrophysics Data System (ADS)

    Li, Nan; Zhao, Jinpei; Wang, Jichang

    2008-06-01

    This study presents an experimental investigation of nonlinear dynamics in a modified Belousov-Zhabotinsky (BZ) reaction, in which the addition of 1,4-benzoquinone induced various complex behaviors such as mixed-mode oscillations and consecutive period-adding bifurcations. In addition, the presence of 1,4-benzoquinone significantly enhanced the photosensitivity of the ferroin-catalyzed BZ system, in which light-induced transitions between simple and complex oscillations have been achieved. Mechanistic study suggests that the influence of benzoquinone may arise from its interactions with the metal catalyst ferroin/ferriin, where cyclic voltammograms illustrate that the presence of benzoquinone causes an increase in the redox potential of ferroin/ferriin couple, which may consequently alternate the oxidation and reduction paths of the catalyst.

  5. Enhanced Specificity of Multiplex Polymerase Chain Reaction via CdTe Quantum Dots

    NASA Astrophysics Data System (ADS)

    Liang, Gaofeng; Ma, Chao; Zhu, Yanliang; Li, Shuchun; Shao, Youhua; Wang, Yong; Xiao, Zhongdang

    2011-12-01

    Nanoparticles were recently reported to be able to improve both efficiency and specificity in polymerase chain reaction (PCR). Here, CdTe QDs were introduced into multi-PCR systems. It was found that an appropriate concentration of CdTe QDs could enhance the performance of multi-PCR by reducing the formation of nonspecific products in the complex system, but an excessive amount of CdTe QDs could suppress the PCR. The effects of QDs on PCR can be reversed by increasing the polymerase concentration or by adding bovine serum albumin (BSA). The mechanisms underlying these effects were also discussed. The results indicated that CdTe QDs could be used to optimize the amplification products of the PCR, especially in the multi-PCR system with different primers annealing temperatures, which is of great significance for molecular diagnosis.

  6. Enhanced hydrogen evolution reaction on hybrids of cobalt phosphide and molybdenum phosphide

    PubMed Central

    Fang, Si-Ling; Chou, Tsu-Chin; Samireddi, Satyanarayana; Chen, Kuei-Hsien; Chen, Li-Chyong

    2017-01-01

    Production of hydrogen from water electrolysis has stimulated the search of sustainable electrocatalysts as possible alternatives. Recently, cobalt phosphide (CoP) and molybdenum phosphide (MoP) received great attention owing to their superior catalytic activity and stability towards the hydrogen evolution reaction (HER) which rivals platinum catalysts. In this study, we synthesize and study a series of catalysts based on hybrids of CoP and MoP with different Co/Mo ratio. The HER activity shows a volcano shape and reaches a maximum for Co/Mo = 1. Tafel analysis indicates a change in the dominating step of Volmer–Hyrovský mechanism. Interestingly, X-ray diffraction patterns confirmed a major ternary interstitial hexagonal CoMoP2 crystal phase is formed which enhances the electrochemical activity.

  7. Use of touch-down polymerase chain reaction to enhance the sensitivity of Mycobacterium bovis detection.

    PubMed

    Zumárraga, Martín J; Meikle, Virginia; Bernardelli, Amelia; Abdala, Alejandro; Tarabla, Hector; Romano, María I; Cataldi, Angel

    2005-05-01

    The confirmatory diagnosis of Mycobacterium bovis (M. bovis) in animal samples is carried out by culture in Stonebrink media. However, culture is very slow because of the extremely long duplication time of the bacillus and difficult because of the scarcity of bacilli in diagnostic samples. This study describes the development of a single-tube touch-down polymerase chain reaction (PCR) protocol for the detection of M. bovis using primers that target the IS6110 element. Spiked water and milk as well as routine diagnostic samples (milk and nasal swabs) from M. bovis-positive cattle were tested. This protocol allows the rapid and sensitive detection of M. bovis in bovine samples by enhancing the sensitivity of standard PCR amplification.

  8. Physiology and immunology of mucosal barriers in catfish (Ictalurus spp.)

    PubMed Central

    Peatman, Eric; Lange, Miles; Zhao, Honggang; Beck, Benjamin H

    2015-01-01

    The mucosal barriers of catfish (Ictalurus spp) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient adsorption, osmoregulation, waste excretion, and environmental sensing. Catfish depend more heavily on mucosal barriers than their terrestrial counterparts as they are continuously interacting with the aquatic microbiota. Our understanding of these barriers, while growing, is still limited relative to that of mammalian model systems. Nevertheless, a combination of molecular and cellular studies in catfish over the last few decades, and particularly within the last few years, has helped to elucidate many of the primary actors and pathways critical to their mucosal health. Here we describe aspects of innate and adaptive immune responses in the primary mucosal tissues (skin, gill, and intestine) of catfish, focusing on mucus-driven responses, pathogen recognition, soluble mediators, and immunoglobulin and T-cell derived immunity. Modulation of mucosal barriers will be critical moving forward for crafting better diets, improving vaccine delivery, enhancing water quality, and ensuring sustainable production practices in catfish. PMID:26716071

  9. Enhanced methanol electro-oxidation reaction on Pt-CoOx/MWCNTs hybrid electro-catalyst

    NASA Astrophysics Data System (ADS)

    Nouralishahi, Amideddin; Rashidi, Ali Morad; Mortazavi, Yadollah; Khodadadi, Abbas Ali; Choolaei, Mohammadmehdi

    2015-04-01

    The electro-catalytic behavior of Pt-CoOx/MWCNTs in methanol electro-oxidation reaction (MOR) is investigated and compared to that of Pt/MWCNTs. The electro-catalysts were synthesized by an impregnation method using NaBH4 as the reducing agent. The morphological and physical characteristics of samples are examined by XRD, TEM, ICP and EDS techniques. In the presence of CoOx, Pt nanoparticles were highly distributed on the support with an average particle size of 2 nm, an obvious decrease from 5.1 nm for Pt/MWCNTs. Cyclic voltammetry, CO-stripping, Chronoamperometry, and electrochemical impedance spectroscopy (EIS) measurements are used to study the electrochemical behavior of the electro-catalysts. The results revealed a considerable enhancement in the oxidation kinetics of COads on Pt active sites by the participation of CoOx. Compared to Pt/MWCNTs, Pt-CoOx/MWCNTs sample has a larger electrochemical active surface area (ECSA) and higher electro-catalytic activity and stability toward methanol electro-oxidation. According to the results of cyclic voltammetry, the forward anodic peak current density enhances more than 89% at the optimum atomic ratio of Pt:Co = 2:1. Furthermore, inclusion of cobalt oxide species causes the onset potential of methanol electro-oxidation reaction to shift 84 mV to negative values compared to that on Pt/MWCNTs. Based on EIS data, dehydrogenation of methanol is the rate-determining step of MOR on both Pt/MWCNTs and Pt-CoOx/MWCNTs, at small overpotentials. However, at higher overpotentials, the oxidation of adsorbed oxygen-containing groups controls the total rate of MOR process.

  10. Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction Reaction

    SciTech Connect

    Loukrakpam, Rameshwori; Shan, Shiyao; Petkov, Valeri; Yang, Lefu; Luo, Jin; Zhong, Chuan-Jian

    2013-10-01

    For oxygen reduction reaction (ORR) over alloy electrocatalysts, the understanding of how the atomic arrangement of the metal species in the nanocatalysts is responsible for the catalytic enhancement is challenging for achieving better design and tailoring of nanoalloy catalysts. This paper reports results of an investigation of the atomic structures and the electrocatalytic activities of ternary and binary nanoalloys, aiming at revealing a fundamental insight into the unique atomic-scale structure-electrocatalytic activity relationship. PtIrCo catalyst and its binary counterparts (PtCo and PtIr) are chosen as a model system for this study. The effect of thermochemical treatment temperature on the atomic-scale structure of the catalysts was examined as a useful probe to the structure-activity correlation. The structural characterization of the binary and ternary nanoalloy catalysts was performed by combining surface sensitive techniques such as XPS and 3D atomic ordering sensitive techniques such as high-energy X-ray diffraction (HE-XRD) coupled to atomic pair distribution function (PDF) analysis (HE-XRD/PDFs) and computer simulations. The results show that the thermal treatment temperature tunes the nanoalloy’s atomic and chemical ordering in a different way depending on the chemical composition, leading to differences in the nanoalloy’s mass and specific activities. A unique structural tunability of the atomic ordering in a platinum-iridium-cobalt nanoalloy has been revealed for enhancing greatly the electrocatalytic activity toward oxygen reduction reaction, which has significant implication for rational design and nanoengineering of advanced catalysts for electrochemical energy conversion and storage.

  11. Sorption enhanced reaction process for production of hydrogen. Phase 1 final report

    SciTech Connect

    Mayorga, S.G.; Hufton, J.R.; Sircar, S.; Gaffney, T.R.

    1997-07-01

    Hydrogen is one of the most suitable energy sources from both technological and environmental perspectives for the next century, especially in the context of a sustainable global energy economy. The most common industrial process to produce high-purity (99.99+ mol%) hydrogen is to reform natural gas by a catalytic reaction with steam at a high temperature. Conventional steam-methane reforming (SMR) contributed to approximately 2.4 billion standard cubic feet per day (SCFD) of hydrogen production in the US. By 1998, the growth of SMR-produced hydrogen in the US is expected to reach 3.4 billion SCFD, with the increased demand attributed to hydrogen`s use in reformulated gasolines required by the Clean Air Act. The goal of this work is to develop an even more efficient process for reforming steam and methane to hydrogen product than the conventional SMR process. The application of Sorption Enhanced Reaction (SER) technology to SMR has the potential to markedly reduce the cost of hydrogen through lower capital and energy requirements. The development of a more cost-effective route to hydrogen production based on natural gas as the primary energy source will accelerate the transition to a more hydrogen-based economy in the future. The paper describes the process, which includes a sorbent for CO{sub 2} removal, and the various tasks involved in its development.

  12. Surface plasmon field-enhanced fluorescence spectroscopy studies of primer extension reactions.

    PubMed

    Stengel, Gudrun; Knoll, Wolfgang

    2005-04-22

    Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) utilizes the evanescent electromagnetic field of a surface plasmon to excite chromophors in close proximity to the surface. While conventional surface plasmon resonance spectroscopy allows the observation of surface reactions by means of refractive index changes, SPFS additionally provides a channel for the read-out of fluorescence changes. Thus, the detection limit for low mass compounds, whose adsorption is only accompanied by small refractive index changes, can be substantially improved by fluorescent labeling. In this study, we present the first example that utilizes SPFS to follow the dynamics of an enzymatic reaction. The elongation of surface-tethered DNA has been observed by the incorporation of Cy5-labeled nucleotides into the nascent strand by the action of DNA polymerase I (Klenow fragment). The technique offers a rapid way to determine the binding constant and the catalytic activity of a DNA processing enzyme, here exemplified by the Klenow fragment. Furthermore, the effect of mispaired bases in the primer/template duplex and the influence of different label densities have been studied. The resulting sensitivity for nucleotide incorporation, being in the femtomolar regime, combined with the specificity of the enzyme for fully complementary DNA duplexes suggest the application of this assay as a powerful tool for DNA detection.

  13. Enhancement of Au Dissolution by Microorganisms Using an Accelerating Cathode Reaction

    NASA Astrophysics Data System (ADS)

    Kita, Yoshito; Nishikawa, Hiroshi; Ike, Michihiko; Takemoto, Tadashi

    2009-02-01

    A Chromobacterium violaceum ( C. violaceum) strain that produces cyanide was used to dissolve Au. In this bacterial Au dissolution process, decreased dissolved oxygen concentration in the bacterial medium significantly inhibits Au dissolution. Although aeration is effective in increasing the level of dissolved oxygen in the bacterial medium, it is not effective in increasing Au dissolution during the growth phase of the bacteria because of the latter’s high respiratory consumption of oxygen. The present study investigated the utility of H2O2, rather than aeration, for increasing dissolved oxygen concentrations in bacterial growth medium. It was anticipated that the stronger oxidation reagent would increase Au dissolution by accelerating the cathode reaction during the bacterial growth phase. In fact, the addition of H2O2 to the bacterial culture increased dissolved oxygen concentrations in the growth phase and also drastically increased the dissolution rate of Au. Electrochemical measurements indicated that H2O2 addition to the bacterial medium accelerated the cathode reaction and thus enhanced Au dissolution by this biological process.

  14. Aldimine Formation Reaction, the First Step of the Maillard Early-phase Reaction, Might be Enhanced in Variant Hemoglobin, Hb Himeji.

    PubMed

    Koga, Masafumi; Inada, Shinya; Shimizu, Sayoko; Hatazaki, Masahiro; Umayahara, Yutaka; Nishihara, Eijun

    2015-01-01

    Hb Himeji (β140Ala→Asp) is known as a variant hemoglobin in which glycation is enhanced and HbA1c measured by immunoassay shows a high value. The phenomenon of enhanced glycation in Hb Himeji is based on the fact that the glycation product of variant hemoglobin (HbX1c) shows a higher value than HbA1c. In this study, we investigated whether aldimine formation reaction, the first step of the Maillard early-phase reaction, is enhanced in Hb Himeji in vitro. Three non-diabetic subjects with Hb Himeji and four non-diabetic subjects without variant hemoglobin were enrolled. In order to examine aldimine formation reaction, whole blood cells were incubated with 500 mg/dl of glucose at 37°C for 1 hour and were analyzed by high-performance liquid chromatography. Both HbA1c and HbX1c were not increased in this condition. After incubation with glucose, labile HbA1c (LA1c) fraction increased in the controls (1.1±0.3%). In subjects with Hb Himeji increases in the labile HbX1c (LX1c) fraction as well as the LA1c fraction were observed, and the degree of increase in the LX1c fraction was significantly higher than that of the LA1c fraction (1.8±0.1% vs. 0.5±0.2%, P<0.01). We have shown for the first time that aldimine (LX1c) formation reaction might be enhanced in Hb Himeji in vitro. The 140th amino acid in β chain of hemoglobin is suggested to be involved in aldimine formation reaction.

  15. Iron medication-induced gastric mucosal injury.

    PubMed

    Zhang, Xuchen; Ouyang, Jie; Wieczorek, Rosemary; DeSoto, Fidelina

    2009-01-01

    Severe gastrointestinal erosion, ulcer, necrosis and strictures after an acute iron overdose are well described. However, gastric mucosal injury in patients receiving therapeutic iron has received only scant recognition despite its wide use. We report a case of iron medication-induced gastric mucosal injury in a 76-year-old male who presented with iron deficiency anemia and had been taking ferrous sulfate tablet for 4 years. Esophagogastroduodenoscopy (EGD) revealed a pale, villous appearing flat lesion along the lesser curvature of gastric body. Histopathologic examination of EGD biopsies of the flat lesion showed brown crystalline materials deposited in the lamina propria of gastric mucosa, which was accompanied with fibrosis, chronic inflammation, and foreign body reaction. The crystalline materials were covered and admixed with gastric epithelium. Prussian blue iron stain confirmed that the brown crystalline materials were iron. The iron and hemosiderin accumulation was also seen in cytoplasm of epithelial cells and lumen of fundic gastric glands. The recognition and reporting by pathologists of iron-induced changes in EGD biopsies will alert clinicians to this underrecognized but easily correctable complication by alternative forms of iron therapy, such as liquid preparation.

  16. Enhancing oxygen reduction reaction activity of Pt-shelled catalysts via subsurface alloying.

    PubMed

    Cheng, Daojian; Qiu, Xiangguo; Yu, Haiyan

    2014-10-14

    Despite remarkable efforts have been put into the field of Pt-shelled catalysts containing an atomically thin Pt surface layer for the oxygen reduction reaction (ORR) in the last decade, further development of new Pt-shelled catalysts is still necessary. Here, a new set of Pt-shelled catalysts by subsurface alloying with early transition metals such as Mn and Fe is predicted to be a good candidate for the ORR by using density functional theory (DFT) calculations. Trends in oxygen reduction activity of Pt-alloy catalysts are determined with calculations of oxygen binding by using the slab and cluster models. It is found that the subsurface alloys by the incorporation of submonolayer M (M = Mn and Fe) into Pt(111) in the slab model result in the enhancement of ORR activity, compared with the well-known Pt(111)-skin-M, pure Pt, and Pt3M alloy catalysts. For the cluster model, the Pt12Mn and Pt12Fe clusters are also found to be the optimal catalysts for the ORR. It is expected that this work can open up new opportunities for enhancing the ORR activity of Pt-alloy catalysts by subsurface alloying.

  17. Dispersion quality of amine functionalized multiwall carbon nanotubes plays critical roles in polymerase chain reaction enhancement

    NASA Astrophysics Data System (ADS)

    Yuce, Meral; Budak, Hikmet

    2014-12-01

    Impact of dispersion quality of NH2-MWCNTs (13-18 nm in diameter with a length between 1 and 12 µm, >99 % purity) in the amplification efficiency of a random DNA oligonucleotide library (96 bp) was investigated. Amplification yield in the presence of non-filtered NH2-MWCNT dispersion, filtered NH2-MWCNT dispersion and surface-attached NH2-MWCNTs was explored, and physical interactions between NH2-MWCNTs and major PCR reagents including DNA template, wild type Taq DNA polymerase enzyme and primers were determined using high resolution polyacrylamide gel electrophoresis, dynamic light scattering, UV-Vis-NIR spectroscopy and scanning electron microscopy techniques. The results revealed that presence of NH2-MWCNT dispersion which was sonicated, centrifuged and filtered, enhanced the total PCR efficiency up to 70 % while the presence of NH2-MWCNT only centrifuged after sonication, inhibited the reaction significantly at similar concentrations. Furthermore, the NH2-MWCNTs coupled covalently onto magnetic microspheres, contributed for the specificity enhancement whilst decreasing the amplification efficiency by 30 % at the maximum concentration, which suggests a removable enhancement system for sensitive applications. On the other hand, the relative hydrodynamic size distribution measurements displayed a clear difference between the filtered NH2 and non-filtered NH2-MWCNT water dispersions, which justifies the inhibition of the amplification by the non-filtered NH2-MWCNTs containing big agglomerates and bundles. Finally, we demonstrated that major PCR components adsorb onto the NH2-MWCNTs with diverse affinities, and maintain their functions after adsorption, which provides a good framework to further develop tunable NH2-MWCNT-carriers to be utilized in various nanobiotechnology and material science applications.

  18. Synthetic polyacrylate polymers as particulate intranasal vaccine delivery systems for the induction of mucosal immune response.

    PubMed

    Zaman, Mehfuz; Simerska, Pavla; Toth, Istvan

    2010-04-01

    The nasal route as a site of vaccine delivery for both local and systemic effect is currently of considerable interest. The administration of vaccines to mucosal surfaces such as the nasopharynx associated lymphoid tissues confers many advantages since the nasal mucosa is a primary site through which most inhaled antigens are encountered. However, the success of intranasally delivered mucosal vaccines is limited by lack of effective vaccine formulations or delivery systems suitable for use in humans. This review provides a brief overview of the mucosal immune system at the nasal surface, enhancement techniques for induction of mucosal immune response after intranasal administration of particulate systems and an explanation of the inherent properties of polyacrylate polymer-based particulate systems that may facilitate mucosal immune responses.

  19. PPS nanoparticles as versatile delivery system to induce systemic and broad mucosal immunity after intranasal administration.

    PubMed

    Stano, Armando; van der Vlies, André J; Martino, Mikael M; Swartz, Melody A; Hubbell, Jeffrey A; Simeoni, Eleonora

    2011-01-17

    Degradable polymer nanoparticles (NPs, 50 nm) based on polypropylene sulfide (PPS) were conjugated to thiolated antigen and adjuvant proteins by reversible disulfide bonds and evaluated in mucosal vaccination. Ovalbumin was used as a model antigen, and antigen-conjugated NPs were administered intranasally in the mouse. We show penetration of nasal mucosae, transit via M cells, and uptake by antigen-presenting cells in the nasal-associated lymphoid tissue. Ovalbumin-conjugated NPs induced cytotoxic T lymphocytic responses in lung and spleen tissues, as well as humoral response in mucosal airways. Co-conjugation of the TLR5 ligand flagellin further enhanced humoral responses in the airways as well as in the distant vaginal and rectal mucosal compartments and induced cellular immune responses with a Th1 bias, in contrast with free flagellin. The PPS NP platform thus appears interesting as a platform for intranasally-administered mucosal vaccination for inducing broad mucosal immunity.

  20. An investigation of the role of water on retrograde/condensation reactions and enhanced liquefaction yields

    SciTech Connect

    Miknis, F.P.

    1992-07-01

    The overall objectives of this work are to conduct research that will provide the basis for an improved liquefaction process, and to facilitate our understanding of those processes that occur when coals are initially dissolved. Changes in coal structure that occur during coal drying and steam pretreatments will be measured in order to determine what effect water has on retrograde/condensation reactions, and to determine the mechanism by which water enhances coal reactivity toward liquefaction. Different methods for coal drying will be investigated to determine if drying can be accomplished without destroying coal reactivity toward liquefaction, thereby making coal drying a relatively economical and efficient method for coal pretreatment. Coal drying methods will include conventional thermal drying, microwave drying, and chemical drying at low temperature. State-of-the-art solid-state nuclear magnetic resonance (NMR) techniques using combined rotation and multiple pulse spectroscopy (CRAMPS) and cross polarization with magic-angle spinning (CP/MAS) will be employed: (1) to measures changes in coal structure brought about by the different methods of drying and by low temperature oxidation, and (2) to obtain direct measurements of changes in the aromatic hydrogen-to-carbon ratio of the solid/semi-solid material formed or remaining during pretreatment and the initial stages of liquefaction. The aromatic hydrogen-to-carbon ratios are difficult, if not impossible, to measure without the use of solid-state NMR, and as a result this ratio will be used to monitor the retrograde/condensation reactions that take place during coal liquefaction in the presence and absence of steam and various inert gases.

  1. Why Chitosan? From properties to perspective of mucosal drug delivery.

    PubMed

    Kumar, Ashwini; Vimal, Archana; Kumar, Awanish

    2016-10-01

    Non-parenteral drug delivery routes primarily remove the local pain at the injection site. The drugs administered through the oral route encounter the process of hepatic first pass metabolism. Among the alternative delivery routes, mucosal route is being investigated as the most preferred route. Different mucosal routes include the gastrointestinal tract (oral), vagina, buccal cavity and nasal cavity. Novel formulations are being developed using natural and synthetic polymers that could increase the residence time of the drug at mucosal surface in order to facilitate permeation and reduce (or bypass) the first pass metabolism. For recombinant drugs, the formulations are accompanied by enzyme inhibitors and penetration enhancers. Buccal cavity (buccal and sublingual mucosa) has smaller surface area than the gastrointestinal tract but the drugs can easily escape the first pass metabolism. Chitosan is the most applied natural polymer while synthetic polymers include Carbopol and Eudragit. Chitosan has inherent properties of mucoadhesion and penetration enhancement apart from biodegradability and efflux pump inhibition. This review hoards the important research purview of chitosan as a compatible drug carrier macromolecule for mucosal delivery on single platform.

  2. Primary mucosal melanomas: a comprehensive review

    PubMed Central

    Mihajlovic, Marija; Vlajkovic, Slobodan; Jovanovic, Predrag; Stefanovic, Vladisav

    2012-01-01

    Primary mucosal melanomas arise from melanocytes located in mucosal membranes lining respiratory, gastrointestinal and urogenital tract. Although a majority of mucosal melanomas originate from the mucosa of the nasal cavity and accessory sinuses, oral cavity, anorectum, vulva and vagina, they can arise in almost any part of mucosal membranes. Most of mucosal melanomas occur in occult sites, which together with the lack of early and specific signs contribute to late diagnosis, and poor prognosis. Because of their rareness the knowledge about their pathogenesis and risk factors is insufficient, and also there are not well established protocols for staging and treatment of mucosal melanomas. Surgery is the mainstay of treatment, with trends toward more conservative treatment since radical surgery did not show an advantage for survival. Radiotherapy can provide better local control in some locations, but did not show improvement in survival. There is no effective systemic therapy for these aggressive tumors. Compared with cutaneous and ocular melanoma, mucosal melanomas have lowest percent of five-year survival. Recently revealed molecular changes underlying mucosal melanomas offer new hope for development of more effective systemic therapy for mucosal melanomas. Herein we presented a comprehensive review of various locations of primary melanoma along mucosal membranes, their epidemiological and clinical features, and treatment options. We also gave a short comparison of some characteristics of cutaneous and mucosal melanomas. PMID:23071856

  3. The Mucosal Immune System of Teleost Fish

    PubMed Central

    Salinas, Irene

    2015-01-01

    Teleost fish possess an adaptive immune system associated with each of their mucosal body surfaces. Evidence obtained from mucosal vaccination and mucosal infection studies reveal that adaptive immune responses take place at the different mucosal surfaces of teleost. The main mucosa-associated lymphoid tissues (MALT) of teleosts are the gut-associated lymphoid tissue (GALT), skin-associated lymphoid tissue (SALT), the gill-associated lymphoid tissue (GIALT) and the recently discovered nasopharynx-associated lymphoid tissue (NALT). Teleost MALT includes diffuse B cells and T cells with specific phenotypes different from their systemic counterparts that have co-evolved to defend the microbe-rich mucosal environment. Both B and T cells respond to mucosal infection or vaccination. Specific antibody responses can be measured in the gills, gut and skin mucosal secretions of teleost fish following mucosal infection or vaccination. Rainbow trout studies have shown that IgT antibodies and IgT+ B cells are the predominant B cell subset in all MALT and respond in a compartmentalized manner to mucosal infection. Our current knowledge on adaptive immunity in teleosts is limited compared to the mammalian literature. New research tools and in vivo models are currently being developed in order to help reveal the great intricacy of teleost mucosal adaptive immunity and help improve mucosal vaccination protocols for use in aquaculture. PMID:26274978

  4. Comprehensive evaluation of molecular enhancers of the isothermal exponential amplification reaction

    PubMed Central

    Mok, Ellie; Wee, Eugene; Wang, Yuling; Trau, Matt

    2016-01-01

    The exponential amplification reaction (EXPAR) is an emerging isothermal nucleic acid amplification method with high potential for molecular diagnostics due to its isothermal nature and high amplification efficiency. However, the use of EXPAR is limited by the high levels of non-specific amplification. Hence, methods that can improve the specificity of EXPAR are desired to facilitate its widespread adoption in practice. Herein, we proposed a strategy to improve EXPAR performance by using molecular enhancers. Eight small molecules were investigated, including ethylene glycol, propylene glycol, betaine, dimethyl sulfoxide (DMSO), trehalose, tetramethylammonium chloride (TMAC), bovine serum albumin (BSA) and single-stranded binding (SSB) proteins. A combination of kinetic and end-point analysis was adopted to investigate how these molecules affected EXPAR performance. Trehalose, TMAC, BSA and SSB proteins were found to have positive effects on EXPAR with trehalose being able to increase the efficiency of EXPAR. In contrast, TMAC, BSA and SSB proteins were shown to increase the specificity of EXPAR. We applied our findings to demonstrate the combination of trehalose and TMAC could simultaneously improve both the efficiency and specificity of an EXPAR-based miRNA detection method. The information provided in this study may serve as a reference to benefit the wider isothermal amplification community. PMID:27910874

  5. Sintering Behavior of Metal Powders Involving Microwave-Enhanced Chemical Reaction

    NASA Astrophysics Data System (ADS)

    Takayama, Sadatsugu; Saito, Yasushi; Sato, Motoyasu; Nagasaka, Takuya; Muroga, Takeo; Ninomiya, Yoshihiko

    2006-03-01

    Copper powder compacts were sintered by microwave radiation in air. In this procedure, the samples were sintered by microwave in air without using any special atmosphere, only by protecting them in a container filled with ceramic powder. The enhancement of the deoxidation reaction by the microwave was observed. The samples were analyzed by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. The samples were deoxidized on the surface and were well sintered to the edge from the inside throughout the entire cross section. The tensile strength of the copper samples sintered by the microwave in air was higher than that found in conventional sintering in N2 gas. No other differences were noticed between the samples sintered by the microwave under the air-rich conditions and in the conventional furnace in H2+N2 gas. The microwave-sintered copper samples were of good quality; for example, the tensile strength measured throughout the cross section was the same as that for the samples sintered in H2+N2 gas by the conventional method.

  6. Enhancing pyridinic nitrogen level in graphene to promote electrocatalytic activity for oxygen reduction reaction

    NASA Astrophysics Data System (ADS)

    Sun, Jiaguang; Wang, Lan; Song, Ranran; Yanga, Shubin

    2016-02-01

    We develop an efficient approach to fabricate nitrogen-doped graphene with tunable pyridinic nitrogen levels (from 1.1 to 1.8 at.%), abundant in-plane holes and high surface areas (623 m2 g-1) via a hydrothermal treatment of graphene oxide with hydrogen peroxide and subsequent annealing under ammonia gas. It is found that the chemical etching is beneficial to the formation of pyridinic nitrogen in graphene during the nitrogen-doping process, which is crucial to enhancing the electrocatalytic properties of graphene for oxygen reduction reaction (ORR). Hence, the optimized NG exhibits good electrocatalytic activity, more positive onset potential than Pt-C (-0.08 V versus -0.09 V), good durability, and high selectivity when it is employed as a metal-free catalyst for ORR. This approach may uncover a mechanism in escalation of pyridinic N atoms doped on the graphene basal edge and provide an efficient platform for the synthesis of a series of heteroatom-doped graphene with tunable heteroatom content for broad applications.

  7. Nystatin and lidocaine pastilles for the local treatment of oral mucositis.

    PubMed

    Silva, Filipa Cosme; Marto, Joana M; Salgado, Ana; Machado, Paula; Silva, Alexandra N; Almeida, António J

    2017-03-01

    Oral mucositis (OM) is a common adverse reaction to radiotherapy and chemotherapy in oncology. Its treatment requires oral formulations that enhance therapy compliance, improve administration and ensure drug effectiveness. Solid dosage forms that act by slow dissolution, such as pastilles, are an effective alternative to mouthwashes, for their versatility, ease of administration and extended residence time in the oral cavity. The present work describes the development and stability studies of an innovative formulation of nystatin and lidocaine pastilles for the treatment of oral mucositis. Full pharmaceutical quality testing was carried out, including disintegration and dissolution testing, texture profile analysis, grittiness and an antifungal activity testing. A soft pastille formulation containing 0.25% lidocaine and 78,000 IU nystatin was obtained, presenting suitable pharmaceutical characteristics, as a disintegration time of 17 ± 2 min, dissolution rate and microbiological and physicochemical for 30 days when stored at 2-8 °C under light protection. Palatability was also evaluated, being well accepted by a panel of 38 healthy volunteers. This formulation allows an accurate drug dosing by the prescriber, while enabling the patients to control the retention time of the drugs in the oral cavity and consequently manage their pain treatment.

  8. Observing Metal-Catalyzed Chemical Reactions in Situ Using Surface-Enhanced Raman Spectroscopy on Pd–Au Nanoshells

    PubMed Central

    Heck, Kimberly N.; Janesko, Benjamin G.; Scuseria, Gustavo E.

    2016-01-01

    Insight into the nature of transient reaction intermediates and mechanistic pathways involved in heterogeneously catalyzed chemical reactions is obtainable from a number of surface spectroscopic techniques. Carrying out these investigations under actual reaction conditions is preferred but remains challenging, especially for catalytic reactions that occur in water. Here, we report the direct spectroscopic study of the catalytic hydrodechlorination of 1,1-dichloroethene in H2O using surface-enhanced Raman spectroscopy (SERS). With Pd islands grown on Au nanoshell films, this reaction can be followed in situ using SERS, exploiting the high enhancements and large active area of Au nanoshell SERS substrates, the transparency of Raman spectroscopy to aqueous solvents, and the catalytic activity enhancement of Pd by the underlying Au metal. The formation and subsequent transformation of several adsorbate species was observed. These results provide the first direct evidence of the room-temperature catalytic hydrodechlorination of a chlorinated solvent, a potentially important pathway for groundwater cleanup, as a sequence of dechlorination and hydrogenation steps. More broadly, the results highlight the exciting prospects of studying catalytic processes in water in situ, like those involved in biomass conversion and proton-exchange membrane fuel cells. PMID:19554693

  9. Microwave-Enhanced Organic Syntheses for the Undergraduate Laboratory: Diels-Alder Cycloaddition, Wittig Reaction, and Williamson Ether Synthesis

    ERIC Educational Resources Information Center

    Baar, Marsha R.; Falcone, Danielle; Gordon, Christopher

    2010-01-01

    Microwave heating enhanced the rate of three reactions typically performed in our undergraduate organic chemistry laboratory: a Diels-Alder cycloaddition, a Wittig salt formation, and a Williamson ether synthesis. Ninety-minute refluxes were shortened to 10 min using a laboratory-grade microwave oven. In addition, yields improved for the Wittig…

  10. Mucosal drug delivery: membranes, methodologies, and applications.

    PubMed

    Song, Yifan; Wang, Yiping; Thakur, Rashmi; Meidan, Victor M; Michniak, Bozena

    2004-01-01

    In recent years, extensive research into novel forms of drug delivery has suggested that mucosal approaches offer a promising therapeutic alternative, especially for systemically acting drugs. Transmucosal drug delivery offers many benefits, including noninvasive administration, convenience, rapid onset, as well as elimination of hepatic first-pass metabolism. The investigated absorptive surfaces consist of the nasal, buccal, ocular, vaginal, and rectal mucosae. Among these, the nasal and buccal routes have proved the most promising to date. The bioavailability achieved mainly depends upon the pathophysiological state of the mucosa and the properties of both the drug and delivery systems. Various agents can increase the efficacy of transmucosal drug delivery. These include cyclodextrins, bile salts, surfactants, fusidic acid derivatives, microspheres, liposomes, and bioadhesive agents. The mechanisms of action, effectiveness, and toxicity profiles of these enhancers have been investigated extensively in both animal and human models.

  11. Mucosal immunology of food allergy.

    PubMed

    Berin, M Cecilia; Sampson, Hugh A

    2013-05-06

    Food allergies are increasing in prevalence at a higher rate than can be explained by genetic factors, suggesting a role for as yet unidentified environmental factors. In this review, we summarize the state of knowledge about the healthy immune response to antigens in the diet and the basis of immune deviation that results in immunoglobulin E (IgE) sensitization and allergic reactivity to foods. The intestinal epithelium forms the interface between the external environment and the mucosal immune system, and emerging data suggest that the interaction between intestinal epithelial cells and mucosal dendritic cells is of particular importance in determining the outcome of immune responses to dietary antigens. Exposure to food allergens through non-oral routes, in particular through the skin, is increasingly recognized as a potentially important factor in the increasing rate of food allergy. There are many open questions on the role of environmental factors, such as dietary factors and microbiota, in the development of food allergy, but data suggest that both have an important modulatory effect on the mucosal immune system. Finally, we discuss recent developments in our understanding of immune mechanisms of clinical manifestations of food allergy. New experimental tools, particularly in the field of genomics and the microbiome, are likely to shed light on factors responsible for the growing clinical problem of food allergy.

  12. Cryopreservation of Human Mucosal Leukocytes

    PubMed Central

    Shu, Zhiquan; Levy, Claire N.; Ferre, April L.; Hartig, Heather; Fang, Cifeng; Lentz, Gretchen; Fialkow, Michael; Kirby, Anna C.; Adams Waldorf, Kristina M.; Veazey, Ronald S.; Germann, Anja; von Briesen, Hagen; McElrath, M. Juliana; Dezzutti, Charlene S.; Sinclair, Elizabeth; Baker, Chris A. R.; Shacklett, Barbara L.; Gao, Dayong; Hladik, Florian

    2016-01-01

    Background Understanding how leukocytes in the cervicovaginal and colorectal mucosae respond to pathogens, and how medical interventions affect these responses, is important for developing better tools to prevent HIV and other sexually transmitted infections. An effective cryopreservation protocol for these cells following their isolation will make studying them more feasible. Methods and Findings To find an optimal cryopreservation protocol for mucosal mononuclear leukocytes, we compared cryopreservation media and procedures using human vaginal leukocytes and confirmed our results with endocervical and colorectal leukocytes. Specifically, we measured the recovery of viable vaginal T cells and macrophages after cryopreservation with different cryopreservation media and handling procedures. We found several cryopreservation media that led to recoveries above 75%. Limiting the number and volume of washes increased the fraction of cells recovered by 10–15%, possibly due to the small cell numbers in mucosal samples. We confirmed that our cryopreservation protocol also works well for both endocervical and colorectal leukocytes. Cryopreserved leukocytes had slightly increased cytokine responses to antigenic stimulation relative to the same cells tested fresh. Additionally, we tested whether it is better to cryopreserve endocervical cells on the cytobrush or in suspension. Conclusions Leukocytes from cervicovaginal and colorectal tissues can be cryopreserved with good recovery of functional, viable cells using several different cryopreservation media. The number and volume of washes has an experimentally meaningful effect on the percentage of cells recovered. We provide a detailed, step-by-step protocol with best practices for cryopreservation of mucosal leukocytes. PMID:27232996

  13. The Therapeutic Effect of PLAG against Oral Mucositis in Hamster and Mouse Model

    PubMed Central

    Lee, Ha-Reum; Yoo, Nina; Kim, Joo Heon; Sohn, Ki-Young; Kim, Heung-Jae; Kim, Myung-Hwan; Han, Mi Young; Yoon, Sun Young; Kim, Jae Wha

    2016-01-01

    Chemotherapy-induced mucositis can limit the effectiveness of cancer therapy and increase the risk of infections. However, no specific therapy for protection against mucositis is currently available. In this study, we investigated the therapeutic effect of PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol, acetylated diglyceride) in 5-fluorouracil (5-FU)-induced oral mucositis animal models. Hamsters were administered 5-FU (80 mg/kg) intraperitoneally on days 0, 6, and 9. The animals’ cheek pouches were then scratched equally with the tip of an 18-gage needle on days 1, 2, and 7. PLAG was administered daily at 250 mg/kg/day. PLAG administration significantly reduced 5-FU/scratching-induced mucositis. Dramatic reversal of weight loss in PLAG-treated hamsters with mucositis was observed. Histochemical staining data also revealed newly differentiated epidermis and blood vessels in the cheek pouches of PLAG-treated hamsters, indicative of recovery. Whole blood analyses indicated that PLAG prevents 5-FU-induced excessive neutrophil transmigration to the infection site and eventually stabilizes the number of circulating neutrophils. In a mouse mucositis model, mice with 5-FU-induced disease treated with PLAG exhibited resistance to body-weight loss compared with mice that received 5-FU or 5-FU/scratching alone. PLAG also dramatically reversed mucositis-associated weight loss and inhibited mucositis-induced inflammatory responses in the tongue and serum. These data suggest that PLAG enhances recovery from 5-FU-induced oral mucositis and may therefore be a useful therapeutic agent for treating side effects of chemotherapy, such as mucositis and cachexia. PMID:27800302

  14. Pharmacological Protection From Radiation {+-} Cisplatin-Induced Oral Mucositis

    SciTech Connect

    Cotrim, Ana P.; Yoshikawa, Masanobu; Sunshine, Abraham N.; Zheng Changyu; Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B.; Baum, Bruce J.

    2012-07-15

    Purpose: To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice after exposure to ionizing radiation {+-} cisplatin. Methods and Materials: Female C3H mice, {approx}8 weeks old, were irradiated with five fractionated doses {+-} cisplatin to induce oral mucositis (lingual ulcers). Just before irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal [ip] injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed and tongues were harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results: Significant lingual ulcers resulted from 5 Multiplication-Sign 8 Gy radiation fractions, which were enhanced with cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions: Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head-and-neck cancer therapy.

  15. Elite Control, Gut CD4 T Cell Sparing, and Enhanced Mucosal T Cell Responses in Macaca nemestrina Infected by a Simian Immunodeficiency Virus Lacking a gp41 Trafficking Motif

    PubMed Central

    Breed, Matthew W.; Elser, Samra E.; Torben, Workineh; Jordan, Andrea P. O.; Aye, Pyone P.; Midkiff, Cecily; Schiro, Faith; Sugimoto, Chie; Alvarez-Hernandez, Xavier; Blair, Robert V.; Somasunderam, Anoma; Utay, Netanya S.; Kuroda, Marcelo J.; Pahar, Bapi; Wiseman, Roger W.; O'Connor, David H.; LaBranche, Celia C.; Montefiori, David C.; Marsh, Mark; Li, Yuan; Piatak, Michael; Lifson, Jeffrey D.; Keele, Brandon F.; Fultz, Patricia N.; Lackner, Andrew A.

    2015-01-01

    ABSTRACT Deletion of Gly-720 and Tyr-721 from a highly conserved GYxxØ trafficking signal in the SIVmac239 envelope glycoprotein cytoplasmic domain, producing a virus termed ΔGY, leads to a striking perturbation in pathogenesis in rhesus macaques (Macaca mulatta). Infected macaques develop immune activation and progress to AIDS, but with only limited and transient infection of intestinal CD4+ T cells and an absence of microbial translocation. Here we evaluated ΔGY in pig-tailed macaques (Macaca nemestrina), a species in which SIVmac239 infection typically leads to increased immune activation and more rapid progression to AIDS than in rhesus macaques. In pig-tailed macaques, ΔGY also replicated acutely to high peak plasma RNA levels identical to those for SIVmac239 and caused only transient infection of CD4+ T cells in the gut lamina propria and no microbial translocation. However, in marked contrast to rhesus macaques, 19 of 21 pig-tailed macaques controlled ΔGY replication with plasma viral loads of <15 to 50 RNA copies/ml. CD4+ T cells were preserved in blood and gut for up to 100 weeks with no immune activation or disease progression. Robust antiviral CD4+ T cell responses were seen, particularly in the gut. Anti-CD8 antibody depletion demonstrated CD8+ cellular control of viral replication. Two pig-tailed macaques progressed to disease with persisting viremia and possible compensatory mutations in the cytoplasmic tail. These studies demonstrate a marked perturbation in pathogenesis caused by ΔGY's ablation of the GYxxØ trafficking motif and reveal, paradoxically, that viral control is enhanced in a macaque species typically predisposed to more pathogenic manifestations of simian immunodeficiency virus (SIV) infection. IMPORTANCE The pathogenesis of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) reflects a balance between viral replication, host innate and adaptive antiviral immune responses, and sustained immune activation

  16. Clinical assessment of oral mucositis and candidiasis compare to chemotherapic nadir in transplanted patients.

    PubMed

    Patussi, Cleverson; Sassi, Laurindo Moacir; Munhoz, Eduardo Ciliao; Zanicotti, Roberta Targa Stramandinoli; Schussel, Juliana Lucena

    2014-01-01

    Oral mucositis is a chief complication in patients undergoing hematopoietic stem cell transplantation (HSCT). It is considered a toxic inflammatory reaction that interferes with the patient's recuperation and quality of life. Oral candidiasis is a common fungal infection observed in dental practice, particularly in immunocompromised patients. The aim of this study was to evaluate the presence of oral mucositis and oral candidiasis in patients who underwent HSCT and their correlation with the chemotherapeutic nadir (lowest possible outcome). We evaluated patients with different diagnoses who underwent HSCT at the Hospital Erasto Gaertner. No chemotherapeutic nadir curves could be associated with mucositis, and patients had different presentations of mucositis. No patient developed oral candidiasis during hospitalization. Together with cell counts, we collected demographic data including age, oral hygiene, habits harmful to health, and the use of oral prostheses. It was observed that patients who smoked cigarettes before hospitalization showed less mucositis, resulting in no feeding problems or other comorbid conditions due to the effect of mucositis. However, the nadir of the chemotherapy curve, in isolation, is not a predictive tool for the appearance (or no appearance) of oral mucositis.

  17. [Dental materials can cause oral allergic reactions].

    PubMed

    Røn Larsen, Kristine; Johansen, Jeanne Duus; Arenholt-Bindslev, Dorthe; Reibel, Jesper; Pedersen, Anne Marie Lynge

    2013-06-17

    A large number of materials used in the diagnosis, treatment and prevention of dental, periodontal and oral mucosal diseases may induce acute or chronic reactions in the oral cavity including allergic reactions. Clinically, it may be difficult to discriminate oral mucosal changes caused by dental materials from changes related to oral mucosal diseases. Diagnosis and management of allergic reactions in the oral mucosa may therefore be a major challenge. The purpose of this paper is to draw attention to commonly used dental materials, which can trigger typical, but also atypical, symptoms and clinical signs of an allergic reaction.

  18. Enhancement of water-gas shift reaction efficiency: catalysts and the catalyst bed arrangement

    NASA Astrophysics Data System (ADS)

    Baronskaya, Natal'ya A.; Minyukova, Tat'yana P.; Khassin, Aleksandr A.; Yurieva, Tamara M.; Parmon, Valentin N.

    2010-12-01

    The results of studies devoted to the search for catalysts of water-gas shift (WGS) reaction that are highly active in a wide temperature interval are generalized. New compositions based on traditional and alternative, as regards the chemical composition, catalysts of high- and low-temperature WGS reaction are considered in detail. The single-stage arrangement of WGS reaction ensuring small temperature gradients in the radial direction of the catalyst bed are discussed.

  19. Quantitative rate determination by dynamic nuclear polarization enhanced NMR of a Diels-Alder reaction.

    PubMed

    Zeng, Haifeng; Lee, Youngbok; Hilty, Christian

    2010-11-01

    Emerging techniques for hyperpolarization of nuclear spins, foremost dynamic nuclear polarization (DNP), lend unprecedented sensitivity to nuclear magnetic resonance spectroscopy. Sufficient signal can be obtained from a single scan, and reactions even far from equilibrium can be studied in real-time. When following the progress of a reaction by nuclear magnetic resonance, however, spin relaxation occurs concomitantly with the reaction to alter resonance line intensities. Here, we present a model for accounting for spin-relaxation in such reactions studied by hyperpolarized NMR. The model takes into account auto- and cross-relaxation in dipole-dipole coupled spin systems and is therefore applicable to NMR of hyperpolarized protons, the most abundant NMR-active nuclei. Applied to the Diels-Alder reaction of 1,4-dipheneylbutadiene (DPBD) with 4-phenyl-1,2,4-triazole-3,5-dione (PTD), reaction rates could be obtained accurately and reproducibly. Additional parameters available from the same experiment include relaxation rates of the reaction product, which may yield further information about the molecular properties of the product. The method presented is also compatible with an experiment where a single spin in the reactant is labeled in its spin-state by a selective radio frequency pulse for subsequent tracking through the reaction, allowing the unambiguous identification of its position in the product molecule. In this case, the chemical shift specificity of high-resolution NMR can allow for the simultaneous determination of reaction rates and mechanistic information in one experiment.

  20. Isoniazid Induced Lupus Presenting as Oral Mucosal Ulcers with Pancytopenia

    PubMed Central

    Ankale, Padmaraj; Sinha, Kanishk; Iyer, Aparna; Jayalakshmi, T.K

    2016-01-01

    Drug Induced Lupus Erythematous (DILE) is a rare adverse reaction to a large variety of drugs including Isoniazid (INH), with features resembling idiopathic Systemic Lupus Erythematosus (SLE). Diagnosis require identification of a temporal relationship between drug administered and symptom. It is an idiosyncratic reaction, with no pre-existing lupus. Our case highlights a rare presentation of isoniazid induced lupus with profound pancytopenia and mucosal ulcers, thus posing a diagnostic challenge. The patient was on multidrug treatment for pulmonary and knee joint tuberculosis. DILE was diagnosed on basis of strongly positive Anti Nuclear Antibodies (ANA), anti ds DNA and antihistone antibodies with clinical response to cessation of INH. PMID:27891378

  1. Mucosal disease series. Number IV. Erythema multiforme.

    PubMed

    Farthing, P; Bagan, J-V; Scully, C

    2005-09-01

    Erythema multiforme (EM) is an acute mucocutaneous hypersensitivity reaction characterised by a skin eruption, with or without oral or other mucous membrane lesions. Occasionally EM may involve the mouth alone. EM has been classified into a number of different variants based on the degree of mucosal involvement and the nature and distribution of the skin lesions. EM minor typically affects no more than one mucosa, is the most common form and may be associated with symmetrical target lesions on the extremities. EM major is more severe, typically involving two or more mucous membranes with more variable skin involvement - which is used to distinguish it from Stevens-Johnson syndrome (SJS), where there is extensive skin involvement and significant morbidity and a mortality rate of 5-15%. Both EM major and SJS can involve internal organs and typically are associated with systemic symptoms. Toxic epidermal necrolysis (TEN) may be a severe manifestation of EM, but some experts regard it as a discrete disease. EM can be triggered by a number of factors, but the best documented is preceding infection with herpes simplex virus (HSV), the lesions resulting from a cell mediated immune reaction triggered by HSV-DNA. SJS and TEN are usually initiated by drugs, and the tissue damage is mediated by soluble factors including Fas and FasL.

  2. The Development of an AIDS Mucosal Vaccine

    PubMed Central

    Tang, Xian; Chen, Zhiwei

    2010-01-01

    It is well known that mucosal tissues contain the largest surface area of the human body and are the front line of natural host defense against various pathogens. In fact, more than 80% of infectious disease pathogens probably gain entry into the susceptible human hosts through open mucosal surfaces. Human immunodeficiency virus type one (HIV-1), a mainly sexually transmitted virus, also primarily targets the vaginal and gastrointestinal mucosa as entry sites for viral transmission, seeding, replication and amplification. Since HIV-1 establishes its early replication in vaginal or rectal mucosal tissues, the induction of sufficient mucosal immunity at the initial site of HIV-1 transmission becomes essential for a protective vaccine. However, despite the fact that current conventional vaccine strategies have remained unsuccessful in preventing HIV-1 infection, sufficient financial support and resources have yet to be given to develop a vaccine able to elicit protective mucosal immunity against sexual transmissions. Interestingly, Chinese ancestors invented variolation through intranasal administration about one thousand years ago, which led to the discovery of a successful smallpox vaccine and the final eradication of the disease. It is the hope for all mankind that the development of a mucosal AIDS vaccine will ultimately help control the AIDS pandemic. In order to discover an effective mucosal AIDS vaccine, it is necessary to have a deep understanding of mucosal immunology and to test various mucosal vaccination strategies. PMID:21994611

  3. Topical therapy for mucosal yeast infections.

    PubMed

    Summers, Paul R

    2011-01-01

    Mucosal yeast infection is best understood as a consequence of compromised mucosal cell-mediated and innate immunity. Defense against oral candidiasis is dominantly cell mediated. The innate immune system may play the main role in regulating vulvovaginal yeast infection. Conditions that compromise cell-mediated immunity such as leukemia, severe illness and HIV infection must be considered as predisposing factors for recurrent oral candidiasis. Compromise of vaginal innate immunity due to mucosal allergy or due to a genetic defect such as mannose-binding lectin deficiency contributes to chronic vulvovaginal yeast infection. Treatment of cofactors must be considered in order to achieve control in recurrent mucosal yeast infection.

  4. Directed surfaces structures and interfaces for enhanced electrocatalyst activity, selectivity, and stability for energy conversion reactions

    SciTech Connect

    Jaramillo, Thomas F.

    2016-04-20

    In this project, we have employed a systematic approach to develop active, selective, and stable catalyst materials for important electrochemical reactions involving energy conversion. In particular, we have focused our attention on developing active catalyst materials for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). HER: We have synthesized and investigated several highly active and acid stable non-precious metal HER catalysts, including: [Mo3S13]2- nanoclusters (Nature Chemistry, 2014) and molybdenum phosphosulfide (MoP|S) (Angewandte Chemie, 2014). We have also aimed to engineer these catalyst formulations in a membrane electrode assembly (MEA) for fundamental studies of water electrolysis at high current densities, approximately 1 A/cm2 (ChemSusChem, 2015). We furthermore investigated transition metal phosphide (TMP) catalysts for HER by a combined experimental–theoretical approach (Energy & Environmental Science, 2015). By synthesizing different TMPs and comparing experimentally determined HER activities with the hydrogen adsorption free energies, ΔGH, calculated by density functional theory, we showed that the TMPs follow a volcano relationship for the HER. Using our combined experimental–theoretical model, we predicted that the mixed metal TMP, Fe0.5Co0.5P, should have a near-optimal ΔGH. We synthesized several mixtures of Co and Fe phosphides alloys and confirmed that Fe0.5Co0.5P exhibits the highest HER activity of the investigated TMPs (Energy & Environmental Science, 2015). The understanding gained as to how to improve catalytic activity for the HER, particularly for non-precious metal materials, is important to DOE targets for sustainable H2 production. OER: We have developed a SrIrO3/IrOx catalyst for acidic conditions (submitted, 2016). The Sr

  5. Mucosal Vaccination Overcomes the Barrier to Recombinant Vaccinia Immunization Caused by Preexisting Poxvirus Immunity

    NASA Astrophysics Data System (ADS)

    Belyakov, Igor M.; Moss, Bernard; Strober, Warren; Berzofsky, Jay A.

    1999-04-01

    Overcoming preexisting immunity to vaccinia virus in the adult population is a key requirement for development of otherwise potent recombinant vaccinia vaccines. Based on our observation that s.c. immunization with vaccinia induces cellular and antibody immunity to vaccinia only in systemic lymphoid tissue and not in mucosal sites, we hypothesized that the mucosal immune system remains naive to vaccinia and therefore amenable to immunization with recombinant vaccinia vectors despite earlier vaccinia exposure. We show that mucosal immunization of vaccinia-immune BALB/c mice with recombinant vaccinia expressing HIV gp160 induced specific serum antibody and strong HIV-specific cytotoxic T lymphocyte responses. These responses occurred not only in mucosal but also in systemic lymphoid tissue, whereas systemic immunization was ineffective under these circumstances. In this context, intrarectal immunization was more effective than intranasal immunization. Boosting with a second dose of recombinant vaccinia was also more effective via the mucosal route. The systemic HIV-specific cytotoxic T lymphocyte response was enhanced by coadministration of IL-12 at the mucosal site. These results also demonstrate the independent compartmentalization of the mucosal versus systemic immune systems and the asymmetric trafficking of lymphocytes between them. This approach to circumvent previous vaccinia immunity may be useful for induction of protective immunity against infectious diseases and cancer in the sizable populations with preexisting immunity to vaccinia from smallpox vaccination.

  6. Developments in the production of mucosal antibodies in plants.

    PubMed

    Vasilev, Nikolay; Smales, C Mark; Schillberg, Stefan; Fischer, Rainer; Schiermeyer, Andreas

    2016-01-01

    Recombinant mucosal antibodies represent attractive target molecules for the development of next generation biopharmaceuticals for passive immunization against various infectious diseases and treatment of patients suffering from mucosal antibody deficiencies. As these polymeric antibodies require complex post-translational modifications and correct subunit assembly, they are considered as difficult-to-produce recombinant proteins. Beside the traditional, mammalian-based production platforms, plants are emerging as alternative expression hosts for this type of complex macromolecule. Plant cells are able to produce high-quality mucosal antibodies as shown by the successful expression of the secretory immunoglobulins A (IgA) and M (IgM) in various antibody formats in different plant species including tobacco and its close relative Nicotiana benthamiana, maize, tomato and Arabidopsis thaliana. Importantly for biotherapeutic application, transgenic plants are capable of synthesizing functional IgA and IgM molecules with biological activity and safety profiles comparable with their native mammalian counterparts. This article reviews the structure and function of mucosal IgA and IgM antibodies and summarizes the current knowledge of their production and processing in plant host systems. Specific emphasis is given to consideration of intracellular transport processes as these affect assembly of the mature immunoglobulins, their secretion rates, proteolysis/degradation and glycosylation patterns. Furthermore, this review provides an outline of glycoengineering efforts that have been undertaken so far to produce antibodies with homogenous human-like glycan decoration. We believe that the continued development of our understanding of the plant cellular machinery related to the heterologous expression of immunoglobulins will further improve the production levels, quality and control of post-translational modifications that are 'human-like' from plant systems and enhance the

  7. Voice Disorders in Mucosal Leishmaniasis

    PubMed Central

    Ruas, Ana Cristina Nunes; Lucena, Márcia Mendonça; da Costa, Ananda Dutra; Vieira, Jéssica Rafael; de Araújo-Melo, Maria Helena; Terceiro, Benivaldo Ramos Ferreira; de Sousa Torraca, Tania Salgado; de Oliveira Schubach, Armando; Valete-Rosalino, Claudia Maria

    2014-01-01

    Introduction Leishmaniasis is considered as one of the six most important infectious diseases because of its high detection coefficient and ability to produce deformities. In most cases, mucosal leishmaniasis (ML) occurs as a consequence of cutaneous leishmaniasis. If left untreated, mucosal lesions can leave sequelae, interfering in the swallowing, breathing, voice and speech processes and requiring rehabilitation. Objective To describe the anatomical characteristics and voice quality of ML patients. Materials and Methods A descriptive transversal study was conducted in a cohort of ML patients treated at the Laboratory for Leishmaniasis Surveillance of the Evandro Chagas National Institute of Infectious Diseases - Fiocruz, between 2010 and 2013. The patients were submitted to otorhinolaryngologic clinical examination by endoscopy of the upper airways and digestive tract and to speech-language assessment through directed anamnesis, auditory perception, phonation times and vocal acoustic analysis. The variables of interest were epidemiologic (sex and age) and clinic (lesion location, associated symptoms and voice quality. Results 26 patients under ML treatment and monitored by speech therapists were studied. 21 (81%) were male and five (19%) female, with ages ranging from 15 to 78 years (54.5+15.0 years). The lesions were distributed in the following structures 88.5% nasal, 38.5% oral, 34.6% pharyngeal and 19.2% laryngeal, with some patients presenting lesions in more than one anatomic site. The main complaint was nasal obstruction (73.1%), followed by dysphonia (38.5%), odynophagia (30.8%) and dysphagia (26.9%). 23 patients (84.6%) presented voice quality perturbations. Dysphonia was significantly associated to lesions in the larynx, pharynx and oral cavity. Conclusion We observed that vocal quality perturbations are frequent in patients with mucosal leishmaniasis, even without laryngeal lesions; they are probably associated to disorders of some resonance

  8. Determination of hydrogen peroxide concentrations by flow injection analysis based on the enhanced chemiluminescent reaction using peroxidase

    SciTech Connect

    Eremin, S.A.; Vlasenko, S.B.; Osipov, A.P.; Eremina, I.D.; Egerov, A.M. )

    1989-01-01

    The technique of flow injection analysis was employed in the determination of hydrogen peroxide. The method was based on the chemiluminescence reaction of luminol with H{sub 2}O{sub 2} which is catalyzed by horseradish peroxidase and enhanced by p-iodophenol. Hydrogen peroxide was linearly detected in the range 10{sup {minus}6}M-10{sup {minus}4}M by measuring the maximum intensity of light emitted. The detection limit is about 1 10{sup {minus}6}M hydrogen peroxide. Transition metal cations at millimolar concentrations do not have any interference on the determination of hydrogen peroxide by FIA based on the enhanced chemiluminescent reaction. This technique is relatively rapid and simple, and permits measurement of up to 80 samples/hr using generally available equipment.

  9. Reaction enhanced channelised fluid-flux along mid- crustal shear zone: An example from Mesoproterozoic Phulad Shear Zone, Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Chatterjee, Sadhana M.; Choudhury, Manideepa Roy; Das, Subhrajyoti

    2016-10-01

    Fluid infiltration at great depth during regional metamorphism plays a major role in mass transport and is responsible for significant rheological changes in the rock. Calc-silicate rocks of the Kajalbas area of Delhi Fold Belt, Rajasthan, are characterised by foliation parallel alternate bands of amphibole-rich and clinopyroxene-plagioclase feldspar-rich layers of varying thicknesses (mm to decimetre thick). Textural relation suggests that the amphibole grains formed from clinopyroxene and plagioclase in the late phase of regional deformation. Algebraic analysis of the reaction textures and mineral compositions was performed with the computer program C-Space to obtain the balanced chemical reactions that led to the formation of amphibole-rich bands. The computed balanced reaction is 70.74 Clinopyroxene + 27.23 Plagioclase + 22.018 H2O + 5.51 K++ 1.00 Mg2++ 27.15 Fe2+ = 22.02 Amphibole + 67.86 SiO2 aqueous + 36.42 Ca2++ 8.98 Na+. The constructed reaction suggests that aqueous fluid permeated the calc-silicate rock along mm to decimetre thick channels, metasomatized the clinopyroxene-plagioclase bearing rocks to form the amphibole-rich layers. The regional deformation presumably created the fluid channels thereby allowing the metasomatic fluid to enter the rock system. The above reaction has large negative volume change for solid phases indicating reaction-induced permeability. Thermodynamic calculations suggest that the fluid-rock interaction occurred at 665 ±05∘C and 6.6 ±0.25 kbar (corresponding to ˜20 km depth). Textural modeling integrating the textural features and balanced chemical reaction of the calc-silicate rocks of Mesoproterozoic Phulad Shear Zone thus indicate that extremely channelled fluid flow was reaction enhanced and caused major change in the rock rheology.

  10. A model SN2 reaction ‘on water’ does not show rate enhancement

    NASA Astrophysics Data System (ADS)

    Nelson, Katherine V.; Benjamin, Ilan

    2011-05-01

    Molecular dynamics calculations of the benchmark nucleophilic substitution reaction (SN2) Cl- + CH3Cl are carried out at the water liquid/vapor interface. The reaction free energy profile and the activation free energy are determined as a function of the reactants' location normal to the surface. The activation free energy remains almost constant relative to that in bulk water, despite the fact that the barrier is expected to significantly decrease as the reaction is carried out near the vapor phase. We show that this is due to the combined effects of a clustering of water molecules around the nucleophile and a relatively weak hydration of the transition state.

  11. Low degree metabolites explain essential reactions and enhance modularity in biological networks

    PubMed Central

    Samal, Areejit; Singh, Shalini; Giri, Varun; Krishna, Sandeep; Raghuram, Nandula; Jain, Sanjay

    2006-01-01

    Background Recently there has been a lot of interest in identifying modules at the level of genetic and metabolic networks of organisms, as well as in identifying single genes and reactions that are essential for the organism. A goal of computational and systems biology is to go beyond identification towards an explanation of specific modules and essential genes and reactions in terms of specific structural or evolutionary constraints. Results In the metabolic networks of Escherichia coli, Saccharomyces cerevisiae and Staphylococcus aureus, we identified metabolites with a low degree of connectivity, particularly those that are produced and/or consumed in just a single reaction. Using flux balance analysis (FBA) we also determined reactions essential for growth in these metabolic networks. We find that most reactions identified as essential in these networks turn out to be those involving the production or consumption of low degree metabolites. Applying graph theoretic methods to these metabolic networks, we identified connected clusters of these low degree metabolites. The genes involved in several operons in E. coli are correctly predicted as those of enzymes catalyzing the reactions of these clusters. Furthermore, we find that larger sized clusters are over-represented in the real network and are analogous to a 'network motif. Using FBA for the above mentioned three organisms we independently identified clusters of reactions whose fluxes are perfectly correlated. We find that the composition of the latter 'functional clusters' is also largely explained in terms of clusters of low degree metabolites in each of these organisms. Conclusion Our findings mean that most metabolic reactions that are essential can be tagged by one or more low degree metabolites. Those reactions are essential because they are the only ways of producing or consuming their respective tagged metabolites. Furthermore, reactions whose fluxes are strongly correlated can be thought of as 'glued

  12. Mucosal immunity and probiotics in fish.

    PubMed

    Lazado, Carlo C; Caipang, Christopher Marlowe A

    2014-07-01

    Teleost mucosal immunity has become the subject of unprecedented research studies in recent years because of its diversity and defining characteristics. Its immune repertoire is governed by the mucosa-associated lymphoid tissues (MALT) which are divided into gut-associated lymphoid tissues (GALT), skin-associated lymphoid tissues (SALT), and gill-associated lymphoid tissues (GIALT). The direct contact with its immediate environment makes the mucosal surfaces of fish susceptible to a wide variety of pathogens. The inherent immunocompetent cells and factors in the mucosal surfaces together with the commensal microbiota have pivotal role against pathogens. Immunomodulation is a popular prophylactic strategy in teleost and probiotics possess this beneficial feature. Most of the studies on the immunomodulatory properties of probiotics in fish mainly discussed their impacts on systemic immunity. In contrast, few of these studies discussed the immunomodulatory features of probiotics in mucosal surfaces and are concentrated on the influences in the gut. Significant attention should be devoted in understanding the relationship of mucosal immunity and probiotics as the present knowledge is limited and are mostly based on extrapolations of studies in humans and terrestrial vertebrates. In the course of the advancement of mucosal immunity and probiotics, new perspectives in probiotics research, e.g., probiogenomics have emerged. This review affirms the relevance of probiotics in the mucosal immunity of fish by revisiting and bridging the current knowledge on teleost mucosal immunity, mucosal microbiota and immunomodulation of mucosal surfaces by probiotics. Expanding the knowledge of immunomodulatory properties of probiotics especially on mucosal immunity is essential in advancing the use of probiotics as a sustainable and viable strategy for successful fish husbandry.

  13. Cage-bell Pt-Pd nanostructures with enhanced catalytic properties and superior methanol tolerance for oxygen reduction reaction

    PubMed Central

    Chen, Dong; Ye, Feng; Liu, Hui; Yang, Jun

    2016-01-01

    Precisely tailoring the structure and fully making use of the components of nanoparticles are effective to enhance their catalytic performance for a given reaction. We herein demonstrate the design of cage-bell structured Pt-Pd nanoparticles, where a Pd shell is deliberately selected to enhance the catalytic property and methanol tolerance of Pt for oxygen reduction reaction. This strategy starts with the synthesis of core-shell Pt@Ag nanoparticles, followed by galvanic replacement reaction between the Ag shell and Pd2+ ions to form core-shell-shell Pt@Ag@Ag-Pd nanoparticles with a Pt core and double shells composed of Ag at inner and alloy Ag-Pd at outer, respectively. Then, the core-shell-shell templates are agitated with saturated NaCl solution to eliminate the Ag component from the double shells, leading to the formation of bimetallic Pt-Pd nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a porous Pd shell, which show enhanced catalytic activity for oxygen reduction compared with that of the Pt seeds due to the additional catalysis from Pd shell. In addition, owing to the different diffusion behavior of methanol and oxygen molecules in the porous Pd shell, the Pt-Pd cage-bell nanostructures also exhibit superior methanol tolerant property in catalyzing the oxygen reduction. PMID:27079897

  14. Cage-bell Pt-Pd nanostructures with enhanced catalytic properties and superior methanol tolerance for oxygen reduction reaction

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Ye, Feng; Liu, Hui; Yang, Jun

    2016-04-01

    Precisely tailoring the structure and fully making use of the components of nanoparticles are effective to enhance their catalytic performance for a given reaction. We herein demonstrate the design of cage-bell structured Pt-Pd nanoparticles, where a Pd shell is deliberately selected to enhance the catalytic property and methanol tolerance of Pt for oxygen reduction reaction. This strategy starts with the synthesis of core-shell Pt@Ag nanoparticles, followed by galvanic replacement reaction between the Ag shell and Pd2+ ions to form core-shell-shell Pt@Ag@Ag-Pd nanoparticles with a Pt core and double shells composed of Ag at inner and alloy Ag-Pd at outer, respectively. Then, the core-shell-shell templates are agitated with saturated NaCl solution to eliminate the Ag component from the double shells, leading to the formation of bimetallic Pt-Pd nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a porous Pd shell, which show enhanced catalytic activity for oxygen reduction compared with that of the Pt seeds due to the additional catalysis from Pd shell. In addition, owing to the different diffusion behavior of methanol and oxygen molecules in the porous Pd shell, the Pt-Pd cage-bell nanostructures also exhibit superior methanol tolerant property in catalyzing the oxygen reduction.

  15. Plasmon-Enhanced Enzymatic Reactions: A Study of Nanoparticle-Enzyme Distance- and Nanoparticle Loading-Dependent Enzymatic Activity

    PubMed Central

    Abel, Biebele; Akinsule, Alice; Andrews, Canisha; Aslan, Kadir

    2011-01-01

    A detailed investigation of the dependence of the efficiency of plasmon-enhanced enzymatic reactions on the distance between silver island films (SIFs) and horse radish peroxidase (HRP) enzyme and on the loading of SIFs on glass surfaces is presented. Three different extent of loading of SIFs on glass slides were used: 1) low, 2) medium and 3) high, which was characterized by using optical absorption spectroscopy and scanning electron microscopy. Streptavidin-linked HRP enzyme was deposited onto SIFs and glass slides by using three different strategies: strategy 1: biotin-avidin protein assay (distance between SIFs and HRP = 4–8 nm), strategy 2: self assembled monolayers (SAMs) (1–5 nm), strategy 3: polymer layer (1–5 nm). The efficiency of enzymatic conversion of O-phenylenediamine dihydrochloride (OPD) to a colored product by HRP on SIFs and glass surfaces was assessed by optical absorption spectroscopy. The distance between SIFs and HRP and the extent of loading of SIFs on the glass surfaces were shown to have significant effect on the efficiency of plasmon-enhanced enzymatic reactions. In this regard, up to an %250 increase in enzymatic conversion of OPD was observed from SIFs with high loading using strategy 1. In addition, we have studied the potential of repeated use of SIFs in plasmon-enhanced enzymatic reactions. PMID:21949594

  16. Plasmon-Enhanced Enzymatic Reactions: A Study of Nanoparticle-Enzyme Distance- and Nanoparticle Loading-Dependent Enzymatic Activity.

    PubMed

    Abel, Biebele; Akinsule, Alice; Andrews, Canisha; Aslan, Kadir

    2011-01-01

    A detailed investigation of the dependence of the efficiency of plasmon-enhanced enzymatic reactions on the distance between silver island films (SIFs) and horse radish peroxidase (HRP) enzyme and on the loading of SIFs on glass surfaces is presented. Three different extent of loading of SIFs on glass slides were used: 1) low, 2) medium and 3) high, which was characterized by using optical absorption spectroscopy and scanning electron microscopy. Streptavidin-linked HRP enzyme was deposited onto SIFs and glass slides by using three different strategies: strategy 1: biotin-avidin protein assay (distance between SIFs and HRP = 4-8 nm), strategy 2: self assembled monolayers (SAMs) (1-5 nm), strategy 3: polymer layer (1-5 nm). The efficiency of enzymatic conversion of O-phenylenediamine dihydrochloride (OPD) to a colored product by HRP on SIFs and glass surfaces was assessed by optical absorption spectroscopy. The distance between SIFs and HRP and the extent of loading of SIFs on the glass surfaces were shown to have significant effect on the efficiency of plasmon-enhanced enzymatic reactions. In this regard, up to an %250 increase in enzymatic conversion of OPD was observed from SIFs with high loading using strategy 1. In addition, we have studied the potential of repeated use of SIFs in plasmon-enhanced enzymatic reactions.

  17. Enhanced electrocatalysis of the oxygen reduction reaction based on pattering of platinum surfaces with cyanide.

    SciTech Connect

    Strmcnik, D.; Escudero-Escribano, M.; Kodama, K.; Stamenkovic, V. R.; Cuesta, A.; Markovic, N. M.; Materials Science Division; Inst. de Quimica Fisica; Toyota Central R&D Labs., Inc.

    2010-08-15

    The slow rate of the oxygen reduction reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the oxygen reduction reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the oxygen reduction reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the oxygen reduction reaction.

  18. Enhanced electrocatalysis of the oxygen reduction reaction based on patterning of platinum surfaces with cyanide

    SciTech Connect

    Strmcnik, D.; Escudero, M.; Kodama, K.; Stamenkovic, V. R.; Cuesta, A.; Markovic, N. M.

    2010-10-01

    The slow rate of the oxygen reduction reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the oxygen reduction reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the oxygen reduction reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the oxygen reduction reaction.

  19. Choice and Design of Adjuvants for Parenteral and Mucosal Vaccines.

    PubMed

    Savelkoul, Huub F J; Ferro, Valerie A; Strioga, Marius M; Schijns, Virgil E J C

    2015-03-05

    The existence of pathogens that escape recognition by specific vaccines, the need to improve existing vaccines and the increased availability of therapeutic (non-infectious disease) vaccines necessitate the rational development of novel vaccine concepts based on the induction of protective cell-mediated immune responses. For naive T-cell activation, several signals resulting from innate and adaptive interactions need to be integrated, and adjuvants may interfere with some or all of these signals. Adjuvants, for example, are used to promote the immunogenicity of antigens in vaccines, by inducing a pro-inflammatory environment that enables the recruitment and promotion of the infiltration of phagocytic cells, particularly antigen-presenting cells (APC), to the injection site. Adjuvants can enhance antigen presentation, induce cytokine expression, activate APC and modulate more downstream adaptive immune reactions (vaccine delivery systems, facilitating immune Signal 1). In addition, adjuvants can act as immunopotentiators (facilitating Signals 2 and 3) exhibiting immune stimulatory effects during antigen presentation by inducing the expression of co-stimulatory molecules on APC. Together, these signals determine the strength of activation of specific T-cells, thereby also influencing the quality of the downstream T helper cytokine profiles and the differentiation of antigen-specific T helper populations (Signal 3). New adjuvants should also target specific (innate) immune cells in order to facilitate proper activation of downstream adaptive immune responses and homing (Signal 4). It is desirable that these adjuvants should be able to exert such responses in the context of mucosal administered vaccines. This review focuses on the understanding of the potential working mechanisms of the most well-known classes of adjuvants to be used effectively in vaccines.

  20. Modulation of gut mucosal biofilms.

    PubMed

    Kleessen, Brigitta; Blaut, Michael

    2005-04-01

    Non-digestible inulin-type fructans, such as oligofructose and high-molecular-weight inulin, have been shown to have the ability to alter the intestinal microbiota composition in such a way that members of the microbial community, generally considered as health-promoting, are stimulated. Bifidobacteria and lactobacilli are the most frequently targeted organisms. Less information exists on effects of inulin-type fructans on the composition, metabolism and health-related significance of bacteria at or near the mucosa surface or in the mucus layer forming mucosa-associated biofilms. Using rats inoculated with a human faecal flora as an experimental model we have found that inulin-type fructans in the diet modulated the gut microbiota by stimulation of mucosa-associated bifidobacteria as well as by partial reduction of pathogenic Salmonella enterica subsp. enterica serovar Typhimurium and thereby benefit health. In addition to changes in mucosal biofilms, inulin-type fructans also induced changes in the colonic mucosa stimulating proliferation in the crypts, increasing the release of mucins, and altering the profile of mucin components in the goblet cells and epithelial mucus layer. These results indicate that inulin-type fructans may stabilise the gut mucosal barrier. Dietary supplementation with these prebiotics could offer a new approach to supporting the barrier function of the mucosa.

  1. Prophylactic and therapeutic modulation of innate and adaptive immunity against mucosal infection of herpes simplex virus.

    PubMed

    Uyangaa, Erdenebileg; Patil, Ajit Mahadev; Eo, Seong Kug

    2014-08-01

    Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are the most common cause of genital ulceration in humans worldwide. Typically, HSV-1 and 2 infections via mucosal route result in a lifelong latent infection after peripheral replication in mucosal tissues, thereby providing potential transmission to neighbor hosts in response to reactivation. To break the transmission cycle, immunoprophylactics and therapeutic strategies must be focused on prevention of infection or reduction of infectivity at mucosal sites. Currently, our understanding of the immune responses against mucosal infection of HSV remains intricate and involves a balance between innate signaling pathways and the adaptive immune responses. Numerous studies have demonstrated that HSV mucosal infection induces type I interferons (IFN) via recognition of Toll-like receptors (TLRs) and activates multiple immune cell populations, including NK cells, conventional dendritic cells (DCs), and plasmacytoid DCs. This innate immune response is required not only for the early control of viral replication at mucosal sites, but also for establishing adaptive immune responses against HSV antigens. Although the contribution of humoral immune response is controversial, CD4(+) Th1 T cells producing IFN-γ are believed to play an important role in eradicating virus from the hosts. In addition, the recent experimental successes of immunoprophylactic and therapeutic compounds that enhance resistance and/or reduce viral burden at mucosal sites have accumulated. This review focuses on attempts to modulate innate and adaptive immunity against HSV mucosal infection for the development of prophylactic and therapeutic strategies. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses. Thus, we summarized the current evidence of various immune mediators in response to mucosal HSV infection, focusing on the importance of innate immune responses.

  2. Antimicrobials, mucosal coating agents, anesthetics, analgesics, and nutritional supplements for alimentary tract mucositis.

    PubMed

    Barasch, Andrei; Elad, Sharon; Altman, Arnold; Damato, Kathryn; Epstein, Joel

    2006-06-01

    This review focuses on the value of several groups of agents for the prevention and treatment of mucositis. The review refers to alimentary mucositis as a generalized term that includes oral mucositis and gastrointestinal mucositis. This paper is part of the systematic review made by the mucositis study group which operates in the Multinational Association of Supportive Care in Cancer (MASCC)/International Society of Oral Oncology (ISOO). Several new guidelines are suggested in this review as an update to the primary systematic review that was published by the same group in 2004.

  3. Localized Pemphigus Vegetans without Mucosal Involvement.

    PubMed

    Jain, Vk; Jindal, N; Imchen, S

    2014-03-01

    Pemphigus vegetans is a rare variant of pemphigus vulgaris. A 62-year-old woman presented with erythematous moist vegetative plaque on the left breast and left groin. There was no mucosal involvement. Histopathological and direct immunofluorescence findings were suggestive of pemphigus vegetans. She showed excellent response to oral steroids. Literature is scarcely available on the limited involvement with pemphigus vegetans without mucosal involvement.

  4. Biology and Mucosal Immunity to Myxozoans

    PubMed Central

    Gómez, Daniela; Bartholomew, Jerri; Sunyer, J. Oriol

    2014-01-01

    Myxozoans are among the most abundant parasites in nature. Their life cycles involve two hosts: an invertebrate, usually an annelid, and a vertebrate, usually a fish. They affect fish species in their natural habitats but also constitute a menace for fish aquaculture. Using different strategies they are able to parasitize and cause damage in multiple organs, including mucosal tissues, which they use also as portals of entry. In fish, the main mucosal sites include the intestine, skin and gills. Recently the finding of a specific mucosal immunoglobulin in teleost (IgT), analogous to mammalian IgA, and the capacity of fish to develop a specific mucosal immune response against different pathogens, has highlighted the importance of studying immune responses at mucosal sites. In this review, we describe the major biological characteristics of myxozoan parasites and present the data available regarding immune responses for species that infect mucosal sites. As models for mucosal immunity we review the responses to Enteromyxum spp. and Ceratomyxa shasta, both of which parasitize the intestine. The immune response at the skin and gills is also described, as these mucosal tissues are used by myxozoans as attaching surfaces and portal of entry, and some species also parasitize these sites. Finally, the development of immunoprophylactic strategies is discussed. PMID:23994774

  5. Mucosal Wave Measurement and Visualization Techniques

    PubMed Central

    Krausert, Christopher R.; Olszewski, Aleksandra E.; Taylor, Lindsay N.; McMurray, James S.; Dailey, Seth H.; Jiang, Jack J.

    2010-01-01

    Organized vibration of the vocal folds is critical to high quality voice production. When the vocal folds oscillate, the superficial tissue of the vocal fold is displaced in a wave-like fashion, creating the so called “mucosal wave”. Because the mucosal wave is dependent on vocal fold structure, physical alterations of that structure cause mucosal wave abnormalities. Visualization and quantification of mucosal wave properties have become useful parameters in diagnosing and managing vocal fold pathology. Mucosal wave measurement provides information about vocal fold characteristics that cannot be determined with other assessment techniques. Here, we discuss the benefits, disadvantages, and clinical applicability of the different mucosal wave measurement techniques, such as electroglottography (EGG), photoglottography (PGG), and ultrasound and visualization techniques that include videokymography (VKG), stroboscopy, and high-speed digital imaging (HSDI). The various techniques and their specific uses are reviewed with the intention of helping researchers and clinicians choose a method for a given situation and understand its limitations as well as its potential applications. Recent applications of these techniques for quantitative assessment demonstrate that additional research must be conducted to realize the full potential of these tools. Evaluations of existing research and recommendations for future research are given to promote both the quantitative study of the mucosal wave through accurate and standardized measurement of mucosal wave parameters and the development of reliable methods with which physicians can diagnose vocal disorders. PMID:20471798

  6. Vaccination Strategies for Mucosal Immune Responses

    PubMed Central

    Ogra, Pearay L.; Faden, Howard; Welliver, Robert C.

    2001-01-01

    Mucosal administration of vaccines is an important approach to the induction of appropriate immune responses to microbial and other environmental antigens in systemic sites and peripheral blood as well as in most external mucosal surfaces. The development of specific antibody- or T-cell-mediated immunologic responses and the induction of mucosally induced systemic immunologic hyporesponsiveness (oral or mucosal tolerance) depend on complex sets of immunologic events, including the nature of the antigenic stimulation of specialized lymphoid structures in the host, antigen-induced activation of different populations of regulatory T cells (Th1 versus Th2), and the expression of proinflammatory and immunoregulatory cytokines. Availability of mucosal vaccines will provide a painless approach to deliver large numbers of vaccine antigens for human immunization. Currently, an average infant will receive 20 to 25 percutaneous injections for vaccination against different childhood infections by 18 months of age. It should be possible to develop for human use effective, nonliving, recombinant, replicating, transgenic, and microbial vector- or plant-based mucosal vaccines to prevent infections. Based on the experience with many dietary antigens, it is also possible to manipulate the mucosal immune system to induce systemic tolerance against environmental, dietary, and possibly other autoantigens associated with allergic and autoimmune disorders. Mucosal immunity offers new strategies to induce protective immune responses against a variety of infectious agents. Such immunization may also provide new prophylactic or therapeutic avenues in the control of autoimmune diseases in humans. PMID:11292646

  7. Mucosal Immunosenescence In The Gastrointestinal Tract

    PubMed Central

    Sato, Shintaro; Kiyono, Hiroshi; Fujihashi, Kohtaro

    2014-01-01

    It has been shown that pathogen-specific secretory IgA (SIgA) antibody (Ab) is the major player at mucosal surfaces for host defense. However, alterations in the mucosal immune system occur in advanced aging which results in a failure of induction of SIgA Abs for protection from infectious diseases. Signs of mucosal senescence first appear in the gut immune system. Further, changes in the intestinal microbiota most likely influence mucosal immunity. To overcome the immunological aging decline in mucosal immunity, several adjuvant systems including mucosal dendritic cell (DC) targeting have been shown to be attractive and effective immunological strategies. Similarly, antigen (Ag) uptake-M cells are ideal targets for facilitating Ag-specific mucosal immune responses. However, the numbers of M cells are reduced in aged mice. In this regard, Spi-B, an essential transcription factor for the functional and structural differentiation of M cells could be a potent strategy for the induction of effective mucosal immunity in aging. PMID:25531743

  8. Mucosal vaccines: a paradigm shift in the development of mucosal adjuvants and delivery vehicles.

    PubMed

    Srivastava, Atul; Gowda, Devegowda Vishakante; Madhunapantula, SubbaRao V; Shinde, Chetan G; Iyer, Meenakshi

    2015-04-01

    Mucosal immune responses are the first-line defensive mechanisms against a variety of infections. Therefore, immunizations of mucosal surfaces from which majority of infectious agents make their entry, helps to protect the body against infections. Hence, vaccinization of mucosal surfaces by using mucosal vaccines provides the basis for generating protective immunity both in the mucosal and systemic immune compartments. Mucosal vaccines offer several advantages over parenteral immunization. For example, (i) ease of administration; (ii) non-invasiveness; (iii) high-patient compliance; and (iv) suitability for mass vaccination. Despite these benefits, to date, only very few mucosal vaccines have been developed using whole microorganisms and approved for use in humans. This is due to various challenges associated with the development of an effective mucosal vaccine that can work against a variety of infections, and various problems concerned with the safe delivery of developed vaccine. For instance, protein antigen alone is not just sufficient enough for the optimal delivery of antigen(s) mucosally. Hence, efforts have been made to develop better prophylactic and therapeutic vaccines for improved mucosal Th1 and Th2 immune responses using an efficient and safe immunostimulatory molecule and novel delivery carriers. Therefore, in this review, we have made an attempt to cover the recent advancements in the development of adjuvants and delivery carriers for safe and effective mucosal vaccine production.

  9. Interfacial engineering of MoS2/TiO2 hybrids for enhanced electrocatalytic hydrogen evolution reaction

    NASA Astrophysics Data System (ADS)

    Song, Xiaolin; Chen, Guifeng; Guan, Lixiu; Zhang, Hui; Tao, Junguang

    2016-09-01

    Herein, we show that the synergistic effect between MoS2 and TiO2 enhances the hydrogen evolution reaction (HER) performance of their hybrids, which is tunable via interface engineering. Among several interfaces, MoS2/TiO2-H complexes exhibit the best HER activity. The observed Tafel slope of 66.9 mV/dec is well in range of previous literature reports, suggesting a Volmer-Heyrovsky mechanism. Enhanced activities were attributed to abundant active sites at the interfaces, as well as improved charge transfer efficiency. Our results emphasize the roles that interfaces play in enhancing the HER activities of MoS2-based heterogeneous catalysts.

  10. Mucosal vaccines: novel strategies and applications for the control of pathogens and tumors at mucosal sites.

    PubMed

    Nizard, Mevyn; Diniz, Mariana O; Roussel, Helene; Tran, Thi; Ferreira, Luis Cs; Badoual, Cecile; Tartour, Eric

    2014-01-01

    The mucosal immune system displays several adaptations reflecting the exposure to the external environment. The efficient induction of mucosal immune responses also requires specific approaches, such as the use of appropriate administration routes and specific adjuvants and/or delivery systems. In contrast to vaccines delivered via parenteral routes, experimental, and clinical evidences demonstrated that mucosal vaccines can efficiently induce local immune responses to pathogens or tumors located at mucosal sites as well as systemic response. At least in part, such features can be explained by the compartmentalization of mucosal B and T cell populations that play important roles in the modulation of local immune responses. In the present review, we discuss molecular and cellular features of the mucosal immune system as well as novel immunization approaches that may lead to the development of innovative and efficient vaccines targeting pathogens and tumors at different mucosal sites.

  11. Alteration of the Redox State with Reactive Oxygen Species for 5-Fluorouracil-Induced Oral Mucositis in Hamsters

    PubMed Central

    Wada-Takahashi, Satoko; Takahashi, Shun-suke; Lee, Masaichi Chang-il

    2013-01-01

    Oral mucositis is often induced in patients receiving cancer chemotherapy treatment. It has been reported that oral mucositis can reduce quality of life, as well as increasing the incidence of mortality. The participation of reactive oxygen species (ROS) in the pathogenesis of oral mucositis is well known, but no report has actually demonstrated the presence of ROS. Thus, the purpose of this study was thus to demonstrate the involvement of ROS and the alteration of the redox state in oral mucositis using an in vivo L-band electron spin resonance (ESR) technique. An oral mucositis animal model induced by treatment of 5-fluorouracil with 10% acetic acid in hamster cheek pouch was used. Lipid peroxidation was measured as the level of malondialdehyde determined by the thiobarbituric acid reaction. The rate constants of the signal decay of nitroxyl compounds using in vivo L-band ESR were calculated from the signal decay curves. Firstly, we established the oral mucositis animal model induced by treatment of 5-fluorouracil with acetic acid in hamster cheek pouch. An increased level of lipid peroxidation in oral mucositis was found by measuring malondialdehyde using isolated hamster cheek pouch ulcer. In addition, as a result of in vivo L-band ESR measurements using our model animals, the decay rate constants of carbamoyl-PROXYL, which is a reagent for detecting the redox balance in tissue, were decreased. These results suggest that a redox imbalance might occur by excessive generation of ROS at an early stage of oral mucositis and the consumption of large quantities of antioxidants including glutathione in the locality of oral mucositis. These findings support the presence of ROS involved in the pathogenesis of oral mucositis with anti-cancer therapy, and is useful for the development of novel therapies drugs for oral mucositis. PMID:24376587

  12. Mucositis management in patients with cancer.

    PubMed

    Keefe, Dorothy M K

    2006-04-01

    Mucositis is an important toxicity to be aware of in anticancer therapy. It contributes to a reduction in cure rates from cancer. Until recently, it has been poorly understood and therefore has not been well managed. It causes patient distress, delays in treatment administration, and reductions in dose intensity, and it costs the health-care system a large amount of money. Mucositis has traditionally been associated more with hematologic malignancies than with solid tumors, because the incidence of severe mucositis has been much higher with the high-dose chemotherapy regimens used in hematologic malignancies. However, the chemotherapy used in solid tumors also causes mucositis and deserves further study. The separation between oral and gastrointestinal mucositis is potentially false and is being removed, with much research now investigating the entire alimentary canal. There are similarities and differences between radiation therapy- and chemotherapy-induced mucositis, and these have implications for treatment and prevention scheduling and type. Risk prediction is another area that requires more work, but there is real hope that, in the future, we might be able to predict who will suffer from mucositis and in which parts of the alimentary canal, thus enabling us to appropriately target the newer antimucotoxic therapies. The Mucositis Study Goup of the Multinational Association for Supportive Care in Cancer has recently published management guidelines for oral and gastrointestinal mucositis and is in the process of updating them. The guidelines serve as an excellent starting place for future mucositis research because they not only review the available treatments but also discuss mechanisms and epidemiology.

  13. Plasma-enhanced microwave solid-state synthesis of cadmium sulfide: reaction mechanism and optical properties.

    PubMed

    Du, Ke-zhao; Chaturvedi, Apoorva; Wang, Xing-zhi; Zhao, Yi; Zhang, Ke-ke; Iqbal Bakti Utama, M; Hu, Peng; Jiang, Hui; Xiong, Qi-hua; Kloc, Christian

    2015-08-14

    CdS synthesis by plasma-enhanced microwave physical vapor transport (PMPVT) has been developed in this work. The photoluminescence (PL), absorbance, Raman spectra and the mechanism of CdS crystal growth have been investigated. Furthermore, plasma-enhanced microwave chemical vapour transport (PMCVT) synthesis of CdS with additional chemical transport agents has been explored. In addition, other II-VI chalcogenides were also synthesized by PMPVT.

  14. Low-energy enhancement of nuclear γ strength and its impact on astrophysical reaction rates

    NASA Astrophysics Data System (ADS)

    Larsen, A. C.; Blasi, N.; Bracco, A.; Bürger, A.; Camera, F.; Eriksen, T. K.; Giacoppo, F.; Goriely, S.; Guttormsen, M.; Görgen, A.; Hagen, T. W.; Harissopulos, S.; Koehler, P. E.; Leoni, S.; Million, B.; Nyhus, H. T.; Renstrøm, T. T.; Rose, S.; Ruud, I. E.; Schiller, A.; Siem, S.; Tornyi, T.; Tveten, G. M.; Voinov, A. V.; Wiedeking, M.

    2014-03-01

    An unexpected enhancement in the low-energy part of the γ-strength function for light and medium-mass nuclei has been discovered at the Oslo Cyclotron Laboratory. This enhancement could lead to an increase in the neutron-capture rates up to two orders of magnitude for very exotic, neutron-rich nuclei. However, it is still an open question whether this structure persists when approaching the neutron drip line.

  15. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    PubMed Central

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-01-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells. PMID:26578100

  16. Surface-Enhanced Raman Spectroscopy Assisted by Radical Capturer for Tracking of Plasmon-Driven Redox Reaction

    PubMed Central

    Yan, Xuefeng; Wang, Lingzhi; Tan, Xianjun; Tian, Baozhu; Zhang, Jinlong

    2016-01-01

    The deep understanding about the photocatalytic reaction induced by the surface plasmon resonance (SPR) effect is desirable but remains a considerable challenge due to the ultrafast relaxation of hole-electron exciton from SPR process and a lack of an efficient monitoring system. Here, using the p-aminothiophenol (PATP) oxidation SPR-catalyzed by Ag nanoparticle as a model reaction, a radical-capturer-assisted surface-enhanced Raman spectroscopy (SERS) has been used as an in-situ tracking technique to explore the primary active species determining the reaction path. Hole is revealed to be directly responsible for the oxidation of PATP to p, p′-dimercaptoazobenzene (4, 4′-DMAB) and O2 functions as an electron capturer to form isolated hole. The oxidation degree of PATP can be further enhanced through a joint utilization of electron capturers of AgNO3 and atmospheric O2, producing p-nitrothiophenol (PNTP) within 10 s due to the improved hole-electron separation efficiency. PMID:27444268

  17. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    NASA Astrophysics Data System (ADS)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  18. Human papillomavirus DNA in oral mucosal lesions.

    PubMed

    Giovannelli, Lucia; Campisi, Giuseppina; Lama, Anna; Giambalvo, Ornella; Osborn, John; Margiotta, Valerio; Ammatuna, Pietro

    2002-03-15

    This study determined the presence of human papillomavirus (HPV) DNA in oral mucosa cells from 121 patients with different types of oral mucosal lesions (13 squamous cell carcinomas, 59 potentially malignant lesions, 49 benign erosive ulcerative lesions) and from 90 control subjects. HPV DNA was detected by nested polymerase chain reaction, and genotype was determined by DNA sequencing. HPV prevalence was 61.5% in carcinomas, 27.1% in potentially malignant lesions, 26.5% in erosive ulcerative lesions, and 5.5% in control subjects. The risk of malignant or potentially malignant lesions was associated with HPV and was statistically significant. HPV-18 was found in 86.5% of HPV-positive lesions but was not associated with a particular type of lesion and was found in 80% of the HPV-positive control subjects. HPV infection was related to older age but not to sex, smoking, or alcohol use; the presence of lesions in the oral cavity increased the risk of HPV infection.

  19. Idiopathic mucosal penile squamous papillomas in dogs.

    PubMed

    Cornegliani, Luisa; Vercelli, Antonella; Abramo, Francesca

    2007-12-01

    A new papillomatous clinical entity is described affecting the penile mucosa of dogs. The animals, 11 male dogs of different breeds, ageing from 6 to 13 years, were presented for genital mass and occasional haematuria. Surgical incision of the prepuce skin of the anaesthetized dogs showed the presence of single pedunculated, soft, pink-red, cauliflower-like masses arising from the penile mucosa, with diameter ranging from 2 to 8 cm. In all cases, histopathological examination of the excised masses showed normal epithelial differentiation with digitiform expansion of all the layers and elongated rete ridges slanted towards the periphery of the lesion. Evidence of ballooning degeneration or basophilic intranuclear inclusion bodies was not found. Both immunohistochemistry and polymerase chain reaction techniques failed to reveal papillomavirus. According to the histological World Health Organization classification of papillomatous lesions and due to the lack of evidence of a viral origin the masses were identified as idiopathic mucosal penile squamous papillomas. Urinary problems resolved after surgical excision, haematuria was therefore considered secondary to ulceration of the papillated masses.

  20. ENHANCING THE STABILITY OF POROUS CATALYSTS WITH SUPERCRITICAL REACTION MEDIA. (R826034)

    EPA Science Inventory

    Adsorption/desorption and pore-transport are key parameters influencing the activity and product selectivity in porous catalysts. With conventional reaction media (gas or liquid phase), one of these parameters is generally favorable while the other is not. For instance, while ...

  1. Method and apparatus for obtaining enhanced production rate of thermal chemical reactions

    DOEpatents

    Tonkovich, Anna Lee Y.; Wang, Yong; Wegeng, Robert S.; Gao, Yufei

    2003-09-09

    Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

  2. Method and apparatus for obtaining enhanced production rate of thermal chemical reactions

    DOEpatents

    Tonkovich, Anna Lee Y.; Wang, Yong; Wegeng, Robert S.; Gao, Yufei

    2006-05-16

    Reactors and processes are disclosed that can utilize high heat fluxes to obtain fast, steady-state reaction rates. Porous catalysts used in conjunction with microchannel reactors to obtain high rates of heat transfer are also disclosed. Reactors and processes that utilize short contact times, high heat flux and low pressure drop are described. Improved methods of steam reforming are also provided.

  3. Emphasizing Multiple Levels of Representation to Enhance Students' Understandings of the Changes Occurring during Chemical Reactions

    ERIC Educational Resources Information Center

    Chandrasegaran, A. L.; Treagust, David F.; Mocerino, Mauro

    2009-01-01

    An alternative program of instruction was implemented with 33 high-achieving Grade 9 students (15-16 years old) in Singapore that overtly focused on the use of macroscopic, submicroscopic, and symbolic representations to describe and explain the changes that occurred during the burning of metals, reactions of dilute acids, ionic precipitations,…

  4. Intestinal mucosal atrophy and adaptation.

    PubMed

    Shaw, Darcy; Gohil, Kartik; Basson, Marc D

    2012-11-28

    Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes.

  5. Intestinal mucosal atrophy and adaptation

    PubMed Central

    Shaw, Darcy; Gohil, Kartik; Basson, Marc D

    2012-01-01

    Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes. PMID:23197881

  6. Baicalin inhibits the fenton reaction by enhancing electron transfer from Fe (2+) to dissolved oxygen.

    PubMed

    Nishizaki, Daisuke; Iwahashi, Hideo

    2015-01-01

    Sho-saiko-to is an herbal medicine that is known to have diverse pharmacological activities and has been used for the treatment of various infectious diseases. Here, we examined the effects of baicalin, a compound isolated from Sho-saiko-to, and the effects of the iron chelator quinolinic acid on the Fenton reaction. The control reaction mixture contained 0.1 M 5,5-dimethyl-1-pyrroline N-oxide (DMPO), 0.2 mM H 2 O 2, 0.2 mM FeSO 4( NH 4)2 SO 4, and 40 mM sodium phosphate buffer (pH 7.4). Upon the addition of 0.6 mM baicalin or quinolinic acid to the control reaction mixture, the ESR peak heights of DMPO/OH radical adducts were measured as 32% ± 1% (baicalin) and 166% ± 27% (quinolinic acid) of that of the control mixture. In order to clarify why baicalin and quinolinic acid exerted opposite effects on the formation of hydroxyl radicals, we measured oxygen consumption in the presence of either compound. Upon the addition of 0.6 mM baicalin (or quinolinic acid) to the control reaction mixture without DMPO and H 2 O 2, the relative oxygen consumption rates were found to be 449% ± 40% (baicalin) and 18% ± 9% (quinolinic acid) of that of the control mixture without DMPO and H 2 O 2, indicating that baicalin facilitated the transfer of electrons from Fe (2+) to dissolved oxygen. Thus, the great majority of Fe (2+) turned into Fe (3+), and the formation of hydroxyl radicals was subsequently inhibited in this reaction.

  7. Enhanced Reactivity in Nucleophilic Acyl Substitution Ion/Ion Reactions Using Triazole-Ester Reagents

    NASA Astrophysics Data System (ADS)

    Bu, Jiexun; Peng, Zhou; Zhao, Feifei; McLuckey, Scott A.

    2017-02-01

    The acyl substitution reactions between 1-hydroxy-7-aza-benzotriazole (HOAt)/1-hydroxy-benzotriazole (HOBt) ester reagents and nucleophilic side chains on peptides have been demonstrated in the gas phase via ion/ion reactions. The HOAt/HOBt ester reagents were synthesized in solution and ionized via negative nano-electrospray ionization. The anionic reagents were then reacted with doubly protonated model peptides containing amines, guanidines, and imidazoles in the gas phase. The complexes formed in the reaction cell were further probed with ion trap collision induced dissociation (CID) yielding either a covalently modified analyte ion or a proton transfer product ion. The covalent reaction yield of HOAt/HOBt ester reagents was demonstrated to be higher than the yield with N-hydroxysuccinimide (NHS) ester reagents over a range of equivalent conditions. Density functional theory (DFT) calculations were performed with a primary amine model system for both triazole-ester and NHS-ester reactants, which indicated a lower transition state barrier for the former reagent, consistent with experiments. The work herein demonstrates that the triazole-ester reagents are more reactive, and therefore less selective, than the analogous NHS-ester reagent. As a consequence, the triazole-ester reagents are the first to show efficient reactivity with unprotonated histidine residues in the gas phase. For all nucleophilic sites and all reagents, covalent reactions are favored under long time, low amplitude activation conditions. This work presents a novel class of reagents capable of gas-phase conjugation to nucleophilic sites in analyte ions via ion/ion chemistry.

  8. Lansoprazole induces mucosal protection through gastrin receptor-dependent up-regulation of cyclooxygenase-2 in rats.

    PubMed

    Tsuji, Shingo; Sun, Wei-Hao; Tsujii, Masahiko; Kawai, Naoki; Kimura, Arata; Kakiuchi, Yoshimi; Yasumaru, Shoichi; Komori, Masato; Murata, Hiroaki; Sasaki, Yutaka; Kawano, Sunao; Hori, Masatsugu

    2002-12-01

    Proton pump inhibitors (PPIs) are antiulcer agents that have both gastric antisecretory and mucosal protective actions. The mechanisms of PPI-induced gastric mucosal protection are not known. The present study was designed to examine the mechanism for lansoprazole-induced gastric mucosal protection in rats. Rats were given 0.5, 5, and 50 mg/kg/day lansoprazole alone or both lansoprazole (50 mg/kg/day) and a specific gastrin receptor antagonist 3R-1-(2,2-diethoxyethyl)-((4-methylphenyl)amino-carbonyl methyl)-3-((4-methylphenyl)ureidoindoline-2- one) (AG-041R) (3, 10, and 30 mg/kg/day) for 14 days. Serum gastrin concentrations were measured. The expression of cyclooxygenases (COX-1 and COX-2) in the gastric mucosa was analyzed using Western blotting and immunohistochemical staining. Another series of rats was used to examine the 1) levels of prostaglandin (PG) E2 in gastric mucosa, 2) influences of the drugs on gastric damage caused by absolute ethanol, and 3) effects of a COX-2-specific inhibitor on PGE2 in the gastric mucosa and the mucosal protection afforded by lansoprazole. Lansoprazole dose dependently increased the serum gastrin concentration and enhanced the mucosal expression of COX-2 but not that of COX-1. Lansoprazole increased gastric mucosal PGE2 and reduced gastric damage caused by ethanol. Concomitant administration of AG-041R abolished the lansoprazole-induced COX-2 expression, and increased mucosal PGE2 and mucosal protection. A specific COX-2 inhibitor blocked the lansoprazole-induced increase in mucosal PGE2 and mucosal protection. Activation of gastrin receptors by endogenous gastrin has a pivotal role in the effects of lansoprazole on COX-2 up-regulation and mucosal protection in the rat stomach.

  9. Enhanced Colloidal Stability of CeO2 Nanoparticles by Ferrous Ions: Adsorption, Redox Reaction, and Surface Precipitation.

    PubMed

    Liu, Xuyang; Ray, Jessica R; Neil, Chelsea W; Li, Qingyun; Jun, Young-Shin

    2015-05-05

    Due to the toxicity of cerium oxide (CeO2) nanoparticles (NPs), a better understanding of the redox reaction-induced surface property changes of CeO2 NPs and their transport in natural and engineered aqueous systems is needed. This study investigates the impact of redox reactions with ferrous ions (Fe2+) on the colloidal stability of CeO2 NPs. We demonstrated that under anaerobic conditions, suspended CeO2 NPs in a 3 mM FeCl2 solution at pH 4.8 were much more stable against sedimentation than those in the absence of Fe2+. Redox reactions between CeO2 NPs and Fe2+ lead to the formation of 6-line ferrihydrite on the CeO2 surfaces, which enhanced the colloidal stability by increasing the zeta potential and hydrophilicity of CeO2 NPs. These redox reactions can affect the toxicity of CeO2 NPs by increasing cerium dissolution, and by creating new Fe(III) (hydr)oxide reactive surface layers. Thus, these findings have significant implications for elucidating the phase transformation and transport of redox reactive NPs in the environment.

  10. Enhanced Reaction Kinetics and Structure Integrity of Ni/SnO2 Nanocluster toward High-Performance Lithium Storage.

    PubMed

    Jiang, Yinzhu; Li, Yong; Zhou, Peng; Yu, Shenglan; Sun, Wenping; Dou, Shixue

    2015-12-09

    SnO2 is regarded as one of the most promising anodes via conversion-alloying mechanism for advanced lithium ion batteries. However, the sluggish conversion reaction severely degrades the reversible capacity, Coulombic efficiency and rate capability. In this paper, through constructing porous Ni/SnO2 composite electrode composed of homogeneously distributed SnO2 and Ni nanoparticles, the reaction kinetics of SnO2 is greatly enhanced, leading to full conversion reaction, superior cycling stability and improved rate capability. The uniformly distributed Ni nanoparticles provide a fast charge transport pathway for electrochemical reactions, and restrict the direct contact and aggregation of SnO2 nanoparticles during cycling. In the meantime, the void space among the nanoclusters increases the contact area between the electrolyte and active materials, and accommodates the huge volume change during cycling as well. The Ni/SnO2 composite electrode possesses a high reversible capacity of 820.5 mAh g(-1) at 1 A g(-1) up to 100 cycles. More impressively, large capacity of 841.9, 806.6, and 770.7 mAh g(-1) can still be maintained at high current densities of 2, 5, and 10 A g(-1) respectively. The results demonstrate that Ni/SnO2 is a high-performance anode for advanced lithium-ion batteries with high specific capacity, excellent rate capability, and cycling stability.

  11. Mucosal acid causes gastric mucosal microcirculatory disturbance in nonsteroidal anti-inflammatory drug-treated rats.

    PubMed

    Funatsu, Toshiyuki; Chono, Koji; Hirata, Takuya; Keto, Yoshihiro; Kimoto, Aishi; Sasamata, Masao

    2007-01-05

    The mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDs) suppress gastric mucosal blood flow is not fully understood, although the depletion of mucosal prostaglandin E2 has been proposed as one possible explanation. We investigated the role of gastric acid on gastric mucosal blood flow in NSAID-treated rats. A rat stomach was mounted in an ex vivo chamber, and gastric mucosal blood flow was measured sequentially in a 5-mm2 area of the gastric corpus using a scanning laser Doppler perfusion image system. Results showed that diclofenac (5 mg/kg s.c.) and indomethacin (10 mg/kg s.c.) did not affect gastric mucosal blood flow, although both strongly decreased mucosal prostaglandin E2 when saline was instilled into the gastric chamber. On replacement of the saline in the chamber with 100 mM hydrochloric acid, these drugs caused a decrease in gastric mucosal blood flow levels within 30 min. The specific cyclooxygenase (COX)-2 inhibitors celecoxib (50 mg/kg s.c.) and rofecoxib (25 mg/kg s.c.) did not affect mucosal prostaglandin E2 level, nor did they decrease gastric mucosal blood flow, even when hydrochloric acid was added to the chamber. Furthermore, measurement of vasoconstrictive factors present in the mucosa showed that endothelin-1 levels increased after administration of diclofenac s.c. in the presence of intragastric hydrochloric acid. This indicates that the presence of mucosal hydrochloric acid plays an important role in the NSAID-induced decrease in gastric mucosal blood flow, while the COX-1-derived basal prostaglandin E2, which is unlikely to control gastric mucosal blood flow itself, protects microcirculatory systems from mucosal hydrochloric acid.

  12. Mucosal Vaccine Development Based on Liposome Technology

    PubMed Central

    Norling, Karin; Bally, Marta; Höök, Fredrik

    2016-01-01

    Immune protection against infectious diseases is most effective if located at the portal of entry of the pathogen. Hence, there is an increasing demand for vaccine formulations that can induce strong protective immunity following oral, respiratory, or genital tract administration. At present, only few mucosal vaccines are found on the market, but recent technological advancements and a better understanding of the principles that govern priming of mucosal immune responses have contributed to a more optimistic view on the future of mucosal vaccines. Compared to live attenuated vaccines, subcomponent vaccines, most often protein-based, are considered safer, more stable, and less complicated to manufacture, but they require the addition of nontoxic and clinically safe adjuvants to be effective. In addition, another limiting factor is the large antigen dose that usually is required for mucosal vaccines. Therefore, the combination of mucosal adjuvants with the recent progress in nanoparticle technology provides an attractive solution to these problems. In particular, the liposome technology is ideal for combining protein antigen and adjuvant into an effective mucosal vaccine. Here, we describe and discuss recent progress in nanoparticle formulations using various types of liposomes that convey strong promise for the successful development of the next generation of mucosal vaccines. PMID:28127567

  13. Treatment of oral mucositis due to chemotherapy

    PubMed Central

    Bagán-Sebastián, José V

    2016-01-01

    Introduction The management of oral mucositis is a challenge, due to its complex biological nature. Over the last 10 years, different strategies have been developed for the management of oral mucositis caused by chemotherapy in cancer patients. Material and Methods An exhaustive search was made of the PubMed-Medline, Cochrane Library and Scopus databases, crossing the key words “oral mucositis”, “prevention” and “treatment” with the terms “chemotherapy” and “radiotherapy” by means of the boolean operators “AND” and “NOT”. A total of 268 articles were obtained, of which 96 met the inclusion criteria. Results Several interventions for the prevention of oral mucositis, such as oral hygiene protocols, amifostine, benzidamine, calcium phosphate, cryotherapy and iseganan, among others, were found to yield only limited benefits. Other studies have reported a decrease in the appearance and severity of mucositis with the use of cytoprotectors (sucralfate, oral glutamine, hyaluronic acid), growth factors, topical polyvinylpyrrolidone, and low power laser irradiation. Conclusions Very few interventions of confirmed efficacy are available for the management of oral mucositis due to chemotherapy. However, according to the reviewed literature, the use of palifermin, cryotherapy and low power laser offers benefits, reducing the incidence and severity of oral mucositis – though further studies are needed to confirm the results obtained. Key words:Chemotherapy-Induced Oral Mucositis Treatment. PMID:27034762

  14. Hypersensitivity to acid is associated with impaired esophageal mucosal integrity in patients with gastroesophageal reflux disease with and without esophagitis.

    PubMed

    Weijenborg, Pim W; Smout, André J P M; Verseijden, Caroline; van Veen, Henk A; Verheij, Joanne; de Jonge, Wouter J; Bredenoord, Albert J

    2014-08-01

    Increased esophageal sensitivity and impaired mucosal integrity have both been described in patients with gastroesophageal reflux disease, but the relationship between hypersensitivity and mucosal integrity is unclear. The aim of the present study was to investigate acid sensitivity in patients with erosive and nonerosive reflux disease and control subjects to determine the relation with functional esophageal mucosal integrity changes as well as to investigate cellular mechanisms of impaired mucosal integrity in these patients. In this prospective experimental study, 12 patients with nonerosive reflux disease, 12 patients with esophagitis grade A or B, and 11 healthy control subjects underwent an acid perfusion test and upper endoscopy. Mucosal integrity was measured during endoscopy by electrical tissue impedance spectroscopy and biopsy specimens were analyzed in Ussing chambers for transepithelial electrical resistance, transepithelial permeability and gene expression of tight junction proteins and filaggrin. Patients with nonerosive reflux disease and esophagitis were more sensitive to acid perfusion compared with control subjects, having a shorter time to perception of heartburn and higher perceived intensity of heartburn. In reflux patients, enhanced acid sensitivity was associated with impairment of in vivo and vitro esophageal mucosal integrity. Mucosal integrity was significantly impaired in patients with esophagitis, displaying higher transepithelial permeability and lower extracellular impedance. Although no significant differences in the expression of tight junction proteins were found in biopsies among patient groups, mucosal integrity parameters in reflux patients correlated negatively with the expression of filaggrin. In conclusion, sensitivity to acid is enhanced in patients with gastroesophageal reflux disease, irrespective of the presence of erosions, and is associated with impaired esophageal mucosal integrity. Mucosal integrity of the esophagus

  15. Covalent grafting of carbon nanotubes with a biomimetic heme model compound to enhance oxygen reduction reactions.

    PubMed

    Wei, Ping-Jie; Yu, Guo-Qiang; Naruta, Yoshinori; Liu, Jin-Gang

    2014-06-23

    The oxygen reduction reaction (ORR) is one of the most important reactions in both life processes and energy conversion systems. The replacement of noble-metal Pt-based ORR electrocatalysts by nonprecious-metal catalysts is crucial for the large-scale commercialization of automotive fuel cells. Inspired by the mechanisms of dioxygen activation by metalloenzymes, herein we report a structurally well-defined, bio-inspired ORR catalyst that consists of a biomimetic model compound-an axial imidazole-coordinated porphyrin-covalently attached to multiwalled carbon nanotubes. Without pyrolysis, this bio-inspired electrocatalyst demonstrates superior ORR activity and stability compared to those of the state-of-the-art Pt/C catalyst in both acidic and alkaline solutions, thus making it a promising alternative as an ORR electrocatalyst for application in fuel-cell technology.

  16. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    DOE PAGES

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fsmore » of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.« less

  17. Prediction of enhanced solvent-induced enantioselectivity for a ring opening with a bifurcating reaction path

    SciTech Connect

    Carpenter, Barry K.; Harvey, Jeremy N.; Glowacki, David R.

    2014-12-11

    Classical molecular dynamics simulations are reported for the deazetisation and ring opening of meso-2,3-difluoro-2,3-dimethyldiazocyclopropane in three solvents: CHCl3, CHFClBr and CH3CH(OH)CF3 (TFIPA). In this study, the achiral reactant leads to enantiomeric allene products, and the question addressed in the study is whether either of the chiral, enantiomerically pure solvents can induce significant enantiomeric excess in the products. The direct dynamics calculations use an empirical valence bond potential for the solute, with empirical parameters optimised against M06-2X/cc-pVTZ density functional results. The results reveal that the exothermic N2 loss and ring opening promote transient strong solvent–solute interactions within the first ~100 fs of the reaction. Because of the bifurcating reaction path, these interactions occur at time when the “decision” about which enantiomer of the product to form has yet to be made (at least for many of the trajectories). Hence, it is possible in principle that the solvent could exert a larger-than-normal influence on the course of the reaction. In fact, the results reveal no such effect for CHFClBr but do predict that TFIPA should induce 15.2 ± 2.1% enantiomeric excess. This is roughly an order of magnitude larger than solvent-induced enantiomeric excesses found experimentally in reactions where the conversion of reactant(s) to enantiomeric products occur over separate transition states.

  18. Reaction/separation process for enhanced methane conversion. Final report, January 1990-December 1994

    SciTech Connect

    Gokhale, Y.V.; Falconer, J.L.; Noble, R.D.

    1995-06-01

    The conventional process for methanol production from natural gas (CH4) is a two-step, energy intensive process. In constrat, direct partial oxidation is a single-step, energy efficient process, but methanol yield is limited due to its thermal instability. The authors proposed a membrane reactor system that could potentially increase the methanol yield. A non-isothermal membrane reactor with a tubular membrane, and a cooling tube located coaxially inside the membrane was built. A pre-heating and a post-membrane sections maintained a constant reactor-wall-temperature in the membrane section. The membrane did not selectively remove methanol from the reaction zone, but it effectively distributed the reaction mixture over the cooling tube which quenched the reaction mixture, and thereby increased the methanol yield. The maximum methanol yield of 3.3% was obtained at 3.5 MPa with 8% O2 in CH4 as feed; the reactor wall temperature was 800 K. Zeolite membranes of silicalite-1 were prepared, and used in a pervaporation apparatus. The membrane increased the methanol concentration from 46 vol% in the feed (as obtained in our membrane reactor study) to 92 vol% in the permeate. Temperature profiles in the reactor were computed by solving momentum and thermal energy balances. The profiles indicated that the postmembrane section could be detrimental to products that are unstable above 420 K.

  19. Animal models of mucositis: implications for therapy.

    PubMed

    Bowen, Joanne M; Gibson, Rachel J; Keefe, Dorothy M K

    2011-01-01

    Alimentary mucositis is a major acute complication in the clinical setting, occurring in a large percentage of patients undergoing cytotoxic therapy. One of the major problems with alimentary mucositis is that the underlying mechanisms behind its development are not entirely understood, which makes it extremely difficult to develop effective interventions. Animal models provide a critical source of knowledge when sampling from patients is unavailable or interventions are yet to be fully tested. This review focuses on the animal models used to increase our understanding of the mechanisms of mucositis and translate new antimucotoxic agents into clinical trials.

  20. ALTERATIONS IN MUCOSAL IMMUNITY IDENTIFIED IN THE COLON OF PATIENTS WITH IRRITABLE BOWEL SYNDROME

    PubMed Central

    Aerssens, Jeroen; Camilleri, Michael; Talloen, Willem; Thielemans, Leen; Göhlmann, Hinrich W. H.; Wyngaert, Ilse Van den; Thielemans, Theo; de Hoogt, Ronald; Andrews, Christopher N.; Bharucha, Adil E.; Carlson, Paula J.; Busciglio, Irene; Burton, Duane D.; Smyrk, Thomas; Urrutia, Raul; Coulie, Bernard

    2008-01-01

    BACKGROUND & AIMS Irritable bowel syndrome (IBS) has been associated with mucosal dysfunction,, mild inflammation, and altered colonic bacteria. We used microarray expression profiling of sigmoid colon mucosa to assess whether there are stably expressed sets of genes that suggest there are objective molecular biomarkers associated with IBS. METHODS Gene expression profiling was performed using Affymetrix GeneChips with RNA from sigmoid colon mucosal biopsies from 36 IBS patients and 25 healthy control subjects. RTQ-PCR was used to confirm the data in 12 genes of interest. Statistical methods for microarray data were applied to search for differentially expressed genes, and to assess the stability of molecular signatures in IBS patients. RESULTS Mucosal gene expression profiles were consistent across different sites within the sigmoid colon and were stable on repeat biopsy over ~3 months. Differentially expressed genes suggest functional alterations of several components of the host mucosal immune response to microbial pathogens. The most strikingly increased expression involved a yet uncharacterized gene, DKFZP564O0823. Identified specific genes suggest the hypothesis that molecular signatures may enable distinction of a subset of IBS patients from healthy controls. Using 75% of the biopsies as a validation set to develop a gene profile, the test set (25%) was correctly predicted with ~70% accuracy. CONCLUSIONS Mucosal gene expression analysis shows there are relatively stable alterations in colonic mucosal immunity in IBS. These molecular alterations provide the basis to test the hypothesis that objective biomarkers may be identified in IBS and enhance understanding of the disease. PMID:18237869

  1. Enhancement of the Chemiluminescence Response of Enzymatic Reactions by Plasmonic Surfaces for Biosensing Applications.

    PubMed

    Abel, Biebele; Odukoya, Babatunde; Mohammed, Muzaffer; Aslan, Kadir

    We report the enhancement of chemiluminescence response of horseradish peroxidase (HRP) in bioassays by plasmonic surfaces, which are comprised of (i) silver island films (SIFs) and (ii) metal thin films (silver, gold, copper, and nickel, 1 nm thick) deposited onto glass slides. A model bioassay, based on the interactions of avidin-modified HRP with a monolayer of biotinylated poly(ethylene-glycol)-amine, was employed to evaluate the ability of plasmonic surfaces to enhance chemiluminescence response of HRP. Chemiluminescence response of HRP in model bioassays were increased up to ~3.7-fold as compared to the control samples (i.e. glass slides without plasmonic nanoparticles), where the largest enhancement of the chemiluminescence response was observed on SIFs with high loading. These findings allowed us to demonstrate the use of SIFs (high loading) for the detection of a biologically relevant target protein (glial fibrillary acidic protein or GFAP), where the chemiluminescence response of the standard bioassay for GFAP was enhanced up to ~50% as compared to bioassay on glass slides.

  2. The enhancement activities of histidyl-histidine in some prebiotic reactions

    NASA Technical Reports Server (NTRS)

    Shen, C.; Lazcano, A.; Oro, J.

    1990-01-01

    The prebiotic synthesis of His and its dimer has led us to study the possible catalytic properties of His-His. The enhancing effect of His-His has been tested in the dephosphorylation of dAMP, the hydrolysis of oligo(A)12, and the oligomerization of 2'3'-cAMP.

  3. Targeting Mucosal Healing in Crohn's Disease

    PubMed Central

    Kakkar, Aarti; Wasan, Sharmeel K.

    2011-01-01

    The goal of medical treatment for Crohn's disease includes improving patients' quality of life while reducing the need for hospitalization and surgery. The current medical armamentarium includes 5-aminosalicylates, corticosteroids, immunomodulators, and biologic agents. In the past, response to treatment was measured by clinical improvement in symptoms; however, with the advent of disease-modifying medications, mucosal healing has emerged as an increasingly important goal of therapy. Mucosal healing, or endoscopic remission, is associated with increased rates of clinical remission, fewer hospitalizations, and fewer abdominal surgeries. Both the immunomodulator and biologic classes of medications are effective at inducing mucosal healing. Despite several limitations, mucosal healing has become a desirable and valid measure of disease activity. PMID:21869869

  4. Microbiota and mucosal immunity in amphibians.

    PubMed

    Colombo, Bruno M; Scalvenzi, Thibault; Benlamara, Sarah; Pollet, Nicolas

    2015-01-01

    We know that animals live in a world dominated by bacteria. In the last 20 years, we have learned that microbes are essential regulators of mucosal immunity. Bacteria, archeas, and viruses influence different aspects of mucosal development and function. Yet, the literature mainly covers findings obtained in mammals. In this review, we focus on two major themes that emerge from the comparative analysis of mammals and amphibians. These themes concern: (i) the structure and functions of lymphoid organs and immune cells in amphibians, with a focus on the gut mucosal immune system; and (ii) the characteristics of the amphibian microbiota and its influence on mucosal immunity. Lastly, we propose to use Xenopus tadpoles as an alternative small-animal model to improve the fundamental knowledge on immunological functions of gut microbiota.

  5. A regenerative approach towards mucosal fenestration closure.

    PubMed

    Gandi, Padma; Anumala, Naveen; Reddy, Amarender; Chandra, Rampalli Viswa

    2013-06-06

    Mucosal fenestration is an opening or an interstice through the oral mucosa. A lesion which occurs with greater frequency than generally realised, its occurrence is attributed to a myriad of causes. Mucogingival procedures including connective tissue grafts, free gingival grafts and lateral pedicle grafts are generally considered to be the treatment of choice in the closure of a mucosal fenestration. More often, these procedures are performed in conjunction with other procedures such as periradicular surgery and with bone grafts. However, the concomitant use of gingival grafts and bone grafts in mucosal fenestrations secondary to infections in sites exhibiting severe bone loss is highly debatable. In this article, we report two cases of mucosal fenestrations secondary to trauma and their management by regenerative periodontal surgery with the placement of guided tissue regeneration membrane and bone graft. The final outcome was a complete closure of the fenestration in both the cases.

  6. Microbiota and Mucosal Immunity in Amphibians

    PubMed Central

    Colombo, Bruno M.; Scalvenzi, Thibault; Benlamara, Sarah; Pollet, Nicolas

    2015-01-01

    We know that animals live in a world dominated by bacteria. In the last 20 years, we have learned that microbes are essential regulators of mucosal immunity. Bacteria, archeas, and viruses influence different aspects of mucosal development and function. Yet, the literature mainly covers findings obtained in mammals. In this review, we focus on two major themes that emerge from the comparative analysis of mammals and amphibians. These themes concern: (i) the structure and functions of lymphoid organs and immune cells in amphibians, with a focus on the gut mucosal immune system; and (ii) the characteristics of the amphibian microbiota and its influence on mucosal immunity. Lastly, we propose to use Xenopus tadpoles as an alternative small-animal model to improve the fundamental knowledge on immunological functions of gut microbiota. PMID:25821449

  7. Mucosal Vaccination against Tuberculosis Using Inert Bioparticles

    PubMed Central

    Reljic, Rajko; Sibley, Laura; Huang, Jen-Min; Pepponi, Ilaria; Hoppe, Andreas; Hong, Huynh A.

    2013-01-01

    Needle-free, mucosal immunization is a highly desirable strategy for vaccination against many pathogens, especially those entering through the respiratory mucosa, such as Mycobacterium tuberculosis. Unfortunately, mucosal vaccination against tuberculosis (TB) is impeded by a lack of suitable adjuvants and/or delivery platforms that could induce a protective immune response in humans. Here, we report on a novel biotechnological approach for mucosal vaccination against TB that overcomes some of the current limitations. This is achieved by coating protective TB antigens onto the surface of inert bacterial spores, which are then delivered to the respiratory tract. Our data showed that mice immunized nasally with coated spores developed humoral and cellular immune responses and multifunctional T cells and, most importantly, presented significantly reduced bacterial loads in their lungs and spleens following pathogenic challenge. We conclude that this new vaccine delivery platform merits further development as a mucosal vaccine for TB and possibly also other respiratory pathogens. PMID:23959722

  8. ENHANCEMENT OF EQUILIBRIUMSHIFT IN DEHYDROGENATION REACTIONS USING A NOVEL MEMBRANE REACTOR

    SciTech Connect

    Shamsuddin Ilias, Ph.d., P.E.; Franklin G. King, D.Sc.

    2001-02-13

    With the advances in new inorganic materials and processing techniques, there has been renewed interest in exploiting the benefits of membranes in many industrial applications. Inorganic and composite membranes are being considered as potential candidates for use in membrane-reactor configuration for effectively increasing reaction rate, selectivity and yield of equilibrium limited reactions. To investigate the usefulness of a palladium-ceramic composite membrane in a membrane reactor-separator configuration, we investigated the dehydrogenation of cyclohexane by equilibrium shift. A two-dimensional pseudo-homogeneous reactor model was developed to study the dehydrogenation of cyclohexane by equilibrium shift in a tubular membrane reactor. Radial diffusion was considered to account for the concentration gradient in the radial direction due to permeation through the membrane. For a dehydrogenation reaction, the feed stream to the reaction side contained cyclohexane and argon, while the separation side used argon as the sweep gas. Equilibrium conversion for dehydrogenation of cyclohexane is 18.7%. The present study showed that 100% conversion could be achieved by equilibrium shift using Pd-ceramic membrane reactor. For a feed containing cyclohexane and argon of 1.64 x 10{sup -6} and 1.0 x 10{sup -3} mol/s, over 98% conversion could be readily achieved. The dehydrogenation of cyclohexane was also experimentally investigated in a palladium-ceramic membrane reactor. The Pd-ceramic membrane was fabricated by electroless deposition of palladium on ceramic substrate. The performance of Pd-ceramic membrane was compared with a commercially available hydrogen-selective ceramic membrane. From limited experimental data it was observed that by appropriate choice of feed flow rate and sweep gas rate, the conversion of cyclohexane to benzene and hydrogen can increased to 56% at atmospheric pressure and 200 C in a Pd-ceramic membrane reactor. In the commercial ceramic membrane

  9. Enhanced osteogenic differentiation of MC3T3-E1 on rhBMP-2-immobilized titanium via click reaction.

    PubMed

    Kim, Eun-Cheol; Kim, Tae-Hee; Jung, Jae-Hoon; Hong, Sung Ok; Lee, Deok-Won

    2014-03-15

    In the present study, we report about the efficacy of titanium surface-immobilized with bone morphogenetic protein-2 (BMP-2) via click reaction on enhanced osteogenic differentiation of MC3T3-E1 cells. The surface was characterized by static contact angles and XPS measurements, which indicated that pristine titanium (Ti-1) was successfully surface-modified via click chemistry (aminated titanium, Ti-4). By quantitative analysis of heparin immobilized on aminated titanium (Ti-4), we found that the Ti-4 can be used as a good candidate to immobilize biomolecules such as heparin. BMP-2 from titanium immobilized with BMP-2 (Ti-6) was released for a period of 28 days in a sustained manner. The highest proliferation rate of MC3T3-E1 cells was observed on Ti-6. Through in vitro tests including alkaline phosphatase (ALP) activity, calcium deposition and real-time polymerase chain reaction (real-time PCR), we found that Ti-6 can be used as a good implant to enhance the osteogenic differentiation of MC3T3-E1 cells.

  10. Design Paradigm Utilizing Reversible Diels-Alder Reactions to Enhance the Mechanical Properties of 3D Printed Materials.

    PubMed

    Davidson, Joshua R; Appuhamillage, Gayan A; Thompson, Christina M; Voit, Walter; Smaldone, Ronald A

    2016-07-06

    A design paradigm is demonstrated that enables new functional 3D printed materials made by fused filament fabrication (FFF) utilizing a thermally reversible dynamic covalent Diels-Alder reaction to dramatically improve both strength and toughness via self-healing mechanisms. To achieve this, we used as a mending agent a partially cross-linked terpolymer consisting of furan-maleimide Diels-Alder (fmDA) adducts that exhibit reversibility at temperatures typically used for FFF printing. When this mending agent is blended with commercially available polylactic acid (PLA) and printed, the resulting materials demonstrate an increase in the interfilament adhesion strength along the z-axis of up to 130%, with ultimate tensile strength increasing from 10 MPa in neat PLA to 24 MPa in fmDA-enhanced PLA. Toughness in the z-axis aligned prints increases by up to 460% from 0.05 MJ/m(3) for unmodified PLA to 0.28 MJ/m(3) for the remendable PLA. Importantly, it is demonstrated that a thermally reversible cross-linking paradigm based on the furan-maleimide Diels-Alder (fmDA) reaction can be more broadly applied to engineer property enhancements and remending abilities to a host of other 3D printable materials with superior mechanical properties.

  11. Polyamines and Gut Mucosal Homeostasis

    PubMed Central

    Timmons, Jennifer; Chang, Elizabeth T.; Wang, Jian-Ying; Rao, Jaladanki N.

    2012-01-01

    The epithelium of gastrointestinal (GI) mucosa has the most rapid turnover rate of any tissue in the body and its integrity is preserved through the dynamic balance between cell migration, proliferation, growth arrest and apoptosis. To maintain tissue homeostasis of the GI mucosa, the rates of epithelial cell division and apoptosis must be highly regulated by various extracellular and intracellular factors including cellular polyamines. Natural polyamines spermidine, spermine and their precursor putrescine, are organic cations in eukaryotic cells and are implicated in the control of multiple signaling pathways and distinct cellular functions. Normal intestinal epithelial growth depends on the available supply of polyamines to the dividing cells in the crypts, and polyamines also regulate intestinal epithelial cell (IEC) apoptosis. Although the specific molecular processes controlled by polyamines remains to be fully defined, increasing evidence indicates that polyamines regulate intestinal epithelial integrity by modulating the expression of various growth-related genes. In this review, we will extrapolate the current state of scientific knowledge regarding the roles of polyamines in gut mucosal homeostasis and highlight progress in cellular and molecular mechanisms of polyamines and their potential clinical applications. PMID:25237589

  12. Effects of iron type in Fenton reaction on mineralization and biodegradability enhancement of hazardous organic compounds.

    PubMed

    Khan, Eakalak; Wirojanagud, Wanpen; Sermsai, Nawarat

    2009-01-30

    The mineralization and biodegradability increase and their combination of two traditional and two relatively new organic contaminants by Fenton reagents with three different types of iron, Fe(2+), Fe(3+), and Fe(0) were investigated. The traditional contaminants examined were trichloroethene (TCE) and 2,4-dichlorophenol (2,4-DCP) while 1,4-dioxane (1,4-D) and 1,2,3-trichloropropane (TCP) were studied for the relatively new contaminants. The mineralization and biodegradability were represented by dissolved organic carbon (DOC) reduction and the ratio of biodegradable dissolved organic carbon and DOC, respectively. For all four contaminants, Fenton reagent using Fe(2+) was more effective in the DOC reduction than Fenton reagents using Fe(3+) and Fe(0) in most cases. The types of Fe that provided maximum biodegradability increase were not the same for all four compounds, Fe(3+) for TCE, Fe(0) for 2,4-DCP, Fe(2+) for 1,4-D, and Fe(3+) for TCP. When the combination of DOC elimination and biodegradability increase (least refractory fraction) was considered, Fe(2+) was the best choice except for 2,4-DCP which was susceptible to Fe(0) catalyzed Fenton reagent the most. The least refractory fractions remaining after 120 min of reaction were 20-25% for TCE, 2,4-DCP, and TCP and 30-40% for 1,4-D. The iron type in Fenton reaction also affected the type of mineralization kinetics of TCE, 2,4-DCP, and TCP as well as the types of degradation by-products of these contaminants. Some of the by-products found, such as isopropanol and propionic aldehyde, which were produced from Fe(0) catalyzed Fenton degradation of TCP, have not been previously reported.

  13. Elderly Fallers Enhance Dynamic Stability Through Anticipatory Postural Adjustments during a Choice Stepping Reaction Time

    PubMed Central

    Tisserand, Romain; Robert, Thomas; Chabaud, Pascal; Bonnefoy, Marc; Chèze, Laurence

    2016-01-01

    In the case of disequilibrium, the capacity to step quickly is critical to avoid falling in elderly. This capacity can be simply assessed through the choice stepping reaction time test (CSRT), where elderly fallers (F) take longer to step than elderly non-fallers (NF). However, the reasons why elderly F elongate their stepping time remain unclear. The purpose of this study is to assess the characteristics of anticipated postural adjustments (APA) that elderly F develop in a stepping context and their consequences on the dynamic stability. Forty-four community-dwelling elderly subjects (20 F and 24 NF) performed a CSRT where kinematics and ground reaction forces were collected. Variables were analyzed using two-way repeated measures ANOVAs. Results for F compared to NF showed that stepping time is elongated, due to a longer APA phase. During APA, they seem to use two distinct balance strategies, depending on the axis: in the anteroposterior direction, we measured a smaller backward movement and slower peak velocity of the center of pressure (CoP); in the mediolateral direction, the CoP movement was similar in amplitude and peak velocity between groups but lasted longer. The biomechanical consequence of both strategies was an increased margin of stability (MoS) at foot-off, in the respective direction. By elongating their APA, elderly F use a safer balance strategy that prioritizes dynamic stability conditions instead of the objective of the task. Such a choice in balance strategy probably comes from muscular limitations and/or a higher fear of falling and paradoxically indicates an increased risk of fall. PMID:27965561

  14. Anionic surfactants enhance click reaction-mediated protein conjugation with ubiquitin.

    PubMed

    Schneider, Daniel; Schneider, Tatjana; Aschenbrenner, Joos; Mortensen, Franziska; Scheffner, Martin; Marx, Andreas

    2016-03-01

    The Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) has become increasingly important in the conjugation chemistry of biomolecules. For example, it is an efficient and convenient method to generate defined ubiquitin-protein conjugates. Here, we investigate the effect of surfactants on the efficiency of CuAAC for chemical protein ubiquitylation. We found that anionic surfactants enhance conjugate formation by up to 10-fold resulting in high yields even at low (i.e., micromolar) concentrations of the reactants. Notably, the herein investigated conjugates are functional and thus properly folded.

  15. Enhancing the specificity and efficiency of polymerase chain reaction using polyethyleneimine-based derivatives and hybrid nanocomposites

    PubMed Central

    Tong, Weiwei; Cao, Xueyan; Wen, Shihui; Guo, Rui; Shen, Mingwu; Wang, Jianhua; Shi, Xiangyang

    2012-01-01

    There is a general necessity to improve the specificity and efficiency of the polymerase chain reaction (PCR), and exploring the PCR-enhancing mechanism still remains a great challenge. In this paper we report the use of branched polyethyleneimine (PEI)-based derivatives and hybrid nanocomposites as a novel class of enhancers to improve the specificity and efficiency of a nonspecific PCR system. We show that the surface-charge polarity of PEI and PEI derivatives plays a major role in their effectiveness to enhance the PCR. Positively charged amine-terminated pristine PEI, partially (50%) acetylated PEI (PEI-Ac50), and completely acetylated PEI (PEI-Ac) are able to improve PCR efficiency and specificity with an optimum concentration order of PEI < PEI-Ac50 < PEI-Ac, whereas negatively charged carboxyl-terminated PEI (PEI-SAH; SAH denotes succinamic acid groups) and neutralized PEI modified with both polyethylene glycol (PEG) and acetyl (Ac) groups (PEI-PEG-Ac) are unable to improve PCR specificity and efficiency even at concentrations three orders of magnitude higher than that of PEI. Our data clearly suggests that the PCR-enhancing effect is primarily based on the interaction between the PCR components and the PEI derivatives, where electrostatic interaction plays a major role in concentrating the PCR components locally on the backbones of the branched PEI. In addition, multiwalled carbon nanotubes modified with PEI and PEI-stabilized gold nanoparticles are also able to improve the PCR specificity and efficiency with an optimum PEI concentration less than that of the PEI alone, indicating that the inorganic component of the nanocomposites may help improve the interaction between PEI and the PCR components. The developed PEI-based derivatives or nanocomposites may be used as efficient additives to enhance other PCR systems for different biomedical applications. PMID:22393296

  16. Enhancement of selective decomposition. Adsorption and reaction of methanethiol on carbon-covered W(001)

    SciTech Connect

    Mullins, D.R.; Lyman, P.F.

    1995-04-13

    Selective decomposition of methanethiol (CH{sub 3}SH) on carbon-covered W(001) to produce methane is enhanced by 75% compared to the clean surface. The maximum enhancement requires only 0.25 monolayers (ML) of preadsorbed C. On a surface percovered with 0.8 ML of C, the methane desorbs in peaks at 460 and 550 K compared to 360 K on the clean surface, suggesting a greater stability in the C-S and C-H bonds. Increased intramolecular bond stability is confirmed by the temperature dependence of the S 2p and C 1s soft X-ray photoemission. Methyl thiolate, CH{sub 3}S, forms upon adsorption at 100 K. Chemisorbed methanethiol, which is not stable on the clean surface, is also observed between 100 and 300 K. The chemisorbed thiol decomposes to form additional thiolate. The thiolate reacts along three competing pathways. It undergoes rehydrogenation and desorbs as methanethiol, it selectively decomposes to form desorbed methane and adsorbed S, or it totally decomposes to form S, C, and desorbed H{sub 2}. 23 refs., 11 figs., 1 tab.

  17. Increased Mucosal CD4+ T Cell Activation in Rhesus Macaques following Vaccination with an Adenoviral Vector

    PubMed Central

    Bukh, Irene; Calcedo, Roberto; Roy, Soumitra; Carnathan, Diane G.; Grant, Rebecca; Qin, Qiuyue; Boyd, Surina; Ratcliffe, Sarah J.; Veeder, Christin L.; Bellamy, Scarlett L.; Betts, Michael R.

    2014-01-01

    ABSTRACT The possibility that vaccination with adenovirus (AdV) vectors increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of HIV acquisition within the Step trial. Modeling this within rhesus macaques is complicated because human adenoviruses, including human adenovirus type 5 (HAdV-5), are not endogenous to macaques. Here, we tested whether vaccination with a rhesus macaque-derived adenoviral vector (simian adenovirus 7 [SAdV-7]) enhances mucosal T cell activation within rhesus macaques. Following intramuscular SAdV-7 vaccination, we observed a pronounced increase in SAdV-7-specific CD4+ T cell responses in peripheral blood and, more dramatically, in rectal mucosa tissue. Vaccination also induced a significant increase in the frequency of activated memory CD4+ T cells in SAdV-7- and HAdV-5-vaccinated animals in the rectal mucosa but not in peripheral blood. These fluctuations within the rectal mucosa were also associated with a pronounced decrease in the relative frequency of naive resting CD4+ T cells. Together, these results indicate that peripheral vaccination with an AdV vector can increase the activation of mucosal CD4+ T cells, potentially providing an experimental model to further evaluate the role of host-vector interactions in increased HIV acquisition after AdV vector vaccination. IMPORTANCE The possibility that vaccination with a human adenovirus 5 vector increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of human immunodeficiency virus (HIV) acquisition within the Step trial. In this study, we tested whether vaccination with a rhesus macaque-derived adenoviral vector in rhesus macaques enhances mucosal CD4+ T cell activation, the main cell target of simian immunodeficiency virus (SIV)/HIV. The results showed that vaccination with an adenoviral vector indeed increases activation of mucosal CD4+ T cells and potentially increases susceptibility to SIV

  18. Enhanced sensitivity of laterl flow strip biosensors based on enyzmatic reaction and nanomaterials

    NASA Astrophysics Data System (ADS)

    Xu, Hui

    Ultrasensitive detection for trace amount of proteins plays pivotal role in the diagnosis of specific diseases in clinical application, basic discovery research and the improvement of proteomics. Recently, lateral flow strip biosensor (LFSB) has gained considerable attention for protein analysis. Compared with the traditional immunoassays, LFSB has several advantages: user-friendly format, short assay time (generally several minutes), less interference due to chromatographic separation, a relatively low cost, and no requirements for skilled technicians. This ideal technique is suitable for on-site testing by people who are untrained. Traditional gold nanoparticles (GNPs) based LFSB have been used for qualitative and semiquantitative analysis, the application of GNP-based LFSB is limited by its low sensitivity. In this dissertation, different nanomaterials and advanced detection technologies have been used to enhance the LFSB sensitivities. An ultrasensitive LFSB based on horseradish peroxidase (HRP)/GNP dual labels was developed for qualitative (Yes/No) and quantitative detection of protein. The LFSB signal was enhanced dramatically by introducing the second tracer (enzyme) on the GNP surface. The detection limit of LFSB was 100 times lower than that of GNP-based LFSB. A fluorescent LFSB based on enzyme tracers was developed for sensitive detection of proteins. Alkaline Phosphatase (ALP) was selected as a label to prepare the LFSB. The signal was from the fluorescent emission of the ELF-97 alcohol precipitate which was the product of ALP catalyzed dephosphorylation of ELF-97 phosphate. ALP-conjugated antibody (ALP-Ab) functionalized gold nanoparticles (GNPs) were used as labels for the development of a chemiluminescence-based quantitative LFSB. The use of chemiluminescence detection and GNPs as enzyme carriers allowed accurate and sensitive analyte detection. GNP-decorated silica nanorods (GNP-SiNRs) were synthesized and employed as the labels for ultrasensitive

  19. Enhancement of the Hydrogen Evolution Reaction from Ni-MoS2 Hybrid Nanoclusters

    PubMed Central

    2016-01-01

    This report focuses on a novel strategy for the preparation of transition metal–MoS2 hybrid nanoclusters based on a one-step, dual-target magnetron sputtering, and gas condensation process demonstrated for Ni-MoS2. Aberration-corrected STEM images coupled with EDX analysis confirms the presence of Ni and MoS2 in the hybrid nanoclusters (average diameter = 5.0 nm, Mo:S ratio = 1:1.8 ± 0.1). The Ni-MoS2 nanoclusters display a 100 mV shift in the hydrogen evolution reaction (HER) onset potential and an almost 3-fold increase in exchange current density compared with the undoped MoS2 nanoclusters, the latter effect in agreement with reported DFT calculations. This activity is only reached after air exposure of the Ni-MoS2 hybrid nanoclusters, suggested by XPS measurements to originate from a Ni dopant atoms oxidation state conversion from metallic to 2+ characteristic of the NiO species active to the HER. Anodic stripping voltammetry (ASV) experiments on the Ni-MoS2 hybrid nanoclusters confirm the presence of Ni-doped edge sites and reveal distinctive electrochemical features associated with both doped Mo-edge and doped S-edge sites which correlate with both their thermodynamic stability and relative abundance. PMID:27818842

  20. Biostability enhancement of oil core - polysaccharide multilayer shell via photoinitiator free thiol-ene 'click' reaction.

    PubMed

    Calcagno, Vincenzo; Vecchione, Raffaele; Sagliano, Angela; Carella, Antonio; Guarnieri, Daniela; Belli, Valentina; Raiola, Luca; Roviello, Antonio; Netti, Paolo A

    2016-06-01

    Layer-by-layer of polyelectrolytes has emerged as one of the easiest and most controlled techniques to deposit ultrathin polymer layers mainly driven by electrostatic interactions. However, this kind of interaction results to be weak and easily breakable in physiological environment. Here we report on the preparation of nanocapsules completely made of natural biomaterials: a lipophilic core (soybean oil and egg lecithin as surfactant) as nanometric template and a polysaccharide-based multilayer shell (glycol chitosan and heparin) covalently cross-linked. We first modified glycol chitosan with a thiol moiety and heparin with an alkene moiety, respectively, and then we built a polymer multilayer film with a covalent cross-linkage among layers, exploiting the light initiated thiol-ene reaction, known as click chemistry. We showed the possibility to perform the covalent cross-linkage without any photoinitiator or metal catalyst, thus avoiding cytotoxic effects and further purification steps. The so realized nanocapsules resulted to be stable and completely biocompatible and, therefore, of interest for the biotechnology fields, mainly for drug delivery.

  1. Three-dimensional ordered mesoporous Co3O4 enhanced by Pd for oxygen evolution reaction

    NASA Astrophysics Data System (ADS)

    Qu, Qing; Zhang, Jian-Hua; Wang, Jing; Li, Qing-Yu; Xu, Chang-Wei; Lu, Xihong

    2017-01-01

    Considerable efforts have been devoted recently to design and fabrication of high performance and low cost electrocatalysts for oxygen evolution reaction (OER). However, catalytic activity of current electrocatalysts is usually restricted by high onset potential and limited active sites. Herein, we fabricated three-dimensional (3D) highly ordered mesoporous Pd-Co3O4 composite materials as excellent electrocatalysts for OER in alkaline solution with high activity and stability. Three-dimensional highly ordered mesoporous Co3O4 material was firstly synthesized using mesoporous silica KIT-6 as hard template. Then, Pd-Co3O4 nanomaterials were prepared by a simple reduction method. The as-prepared 3D mesoporous Pd-Co3O4 catalysts have ordered mesoporous structure with a high surface area of 81.0 m2 g‑1. Three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen. Moreover, the catalysts can also keep catalyst particles in a well dispersed condition with more catalytic active sites. Electrochemical measurements reveal that the 3D mesoporous Pd-Co3O4 catalysts exhibit superior performance in alkaline solution with low onset potential (0.415 V vs. SCE) and excellent long-duration cycling stability.

  2. α-1 Antitrypsin Enhances Islet Engraftment by Suppression of Instant Blood-Mediated Inflammatory Reaction.

    PubMed

    Wang, Jingjing; Sun, Zhen; Gou, Wenyu; Adams, David B; Cui, Wanxing; Morgan, Katherine A; Strange, Charlie; Wang, Hongjun

    2017-04-01

    Islet cell transplantation has limited effectiveness because of an instant blood-mediated inflammatory reaction (IBMIR) that occurs immediately after cell infusion and leads to dramatic β-cell death. In intraportal islet transplantation models using mouse and human islets, we demonstrated that α-1 antitrypsin (AAT; Prolastin-C), a serine protease inhibitor used for the treatment of AAT deficiency, inhibits IBMIR and cytokine-induced inflammation in islets. In mice, more diabetic recipients reached normoglycemia after intraportal islet transplantation when they were treated with AAT compared with mice treated with saline. AAT suppressed blood-mediated coagulation pathways by diminishing tissue factor production, reducing plasma thrombin-antithrombin complex levels and fibrinogen deposition on islet grafts, which correlated with less graft damage and apoptosis. AAT-treated mice showed reduced serum tumor necrosis factor-α levels, decreased lymphocytic infiltration, and decreased nuclear factor (NF)-κB activation compared with controls. The potent anti-inflammatory effect of AAT is possibly mediated by suppression of c-Jun N-terminal kinase (JNK) phosphorylation. Blocking JNK activation failed to further reduce cytokine-induced apoptosis in β-cells. Taken together, AAT significantly improves islet graft survival after intraportal islet transplantation by mitigation of coagulation in IBMIR and suppression of cytokine-induced JNK and NF-κB activation. AAT-based therapy has the potential to improve graft survival in human islet transplantation and other cellular therapies on the horizon.

  3. Three-dimensional ordered mesoporous Co3O4 enhanced by Pd for oxygen evolution reaction

    PubMed Central

    Qu, Qing; Zhang, Jian-Hua; Wang, Jing; Li, Qing-Yu; Xu, Chang-Wei; Lu, Xihong

    2017-01-01

    Considerable efforts have been devoted recently to design and fabrication of high performance and low cost electrocatalysts for oxygen evolution reaction (OER). However, catalytic activity of current electrocatalysts is usually restricted by high onset potential and limited active sites. Herein, we fabricated three-dimensional (3D) highly ordered mesoporous Pd-Co3O4 composite materials as excellent electrocatalysts for OER in alkaline solution with high activity and stability. Three-dimensional highly ordered mesoporous Co3O4 material was firstly synthesized using mesoporous silica KIT-6 as hard template. Then, Pd-Co3O4 nanomaterials were prepared by a simple reduction method. The as-prepared 3D mesoporous Pd-Co3O4 catalysts have ordered mesoporous structure with a high surface area of 81.0 m2 g−1. Three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen. Moreover, the catalysts can also keep catalyst particles in a well dispersed condition with more catalytic active sites. Electrochemical measurements reveal that the 3D mesoporous Pd-Co3O4 catalysts exhibit superior performance in alkaline solution with low onset potential (0.415 V vs. SCE) and excellent long-duration cycling stability. PMID:28134348

  4. Unilateral balance training enhances neuromuscular reactions to perturbations in the trained and contralateral limb.

    PubMed

    Oliveira, Anderson Souza Castelo; Brito Silva, Priscila; Farina, Dario; Kersting, Uwe Gustav

    2013-09-01

    The aim of this study was to investigate the effect of unilateral balance training on the reactive recovery of balance for both trained and untrained limbs. Twenty-three subjects were randomly assigned to either a control group (CG) or a training group (TG). The latter performed six weeks of balance training for the right leg. The pre- and post-training measurements were based on single leg standing posture on a moveable force platform which moved 6 cm anteriorly. TG subjects were tested on the trained (TR) and untrained leg (UTR), whereas CG subjects were tested on the right leg (CTR). The center of pressure trajectory length (CPLEN) and average speed (CPSPD) as well as onsets of muscular activation and time to peak (EMGTP) from lower limb muscles were calculated and compared by a 2-way ANOVA (three legs×two training status). Muscular onsets were reduced after training for TR (∼19 ms, p<0.05) and UTR (∼17 ms, p<0.05) with no significant changes for CTR. No effects of training for CPLEN and medial-lateral CPSPD were found. Furthermore, the EMGTP of UTR was predominantly greater before training (∼17 ms, p<0.05). However, after training the EMGTP was similar among limbs. These results suggest that concomitant with improved balance recovery and neuromuscular reactions in TR, there is also a cross-education effect in UTR, which might be predominantly related to supraspinal adaptations shared between interconnected structures in the brain.

  5. Triggering comprehensive enhancement in oxygen evolution reaction by using newly created solvent

    PubMed Central

    Chen, Hsiao-Chien; Mai, Fu-Der; Yang, Kuang-Hsuan; Chen, Liang-Yih; Yang, Chih-Ping; Liu, Yu-Chuan

    2016-01-01

    Theoretical calculations indicate that the properties of confined liquid water, or liquid water at surfaces, are dramatically different from those of liquid bulk water. Here we present an experimentally innovative strategy on comprehensively efficient oxygen evolution reaction (OER) utilizing plasmon-induced activated water, creating from hot electron decay at resonantly illuminated Au nanoparticles (NPs). Compared to conventional deionized (DI) water, the created water owns intrinsically reduced hydrogen-bonded structure and a higher chemical potential. The created water takes an advantage in OER because the corresponding activation energy can be effectively reduced by itself. Compared to DI water-based solutions, the OER efficiencies at Pt electrodes increased by 69.3%, 21.1% and 14.5% in created water-based acidic, neutral and alkaline electrolyte solutions, respectively. The created water was also effective for OERs in photoelectrochemically catalytic and in inert systems. In addition, the efficiency of OER increased by 47.5% in created water-based alkaline electrolyte solution prepared in situ on a roughened Au electrode. These results suggest that the created water has emerged as an innovative activator in comprehensively effective OERs. PMID:27328821

  6. Electric Field-Enhanced Catalytic Conversion of Methane: AN Experimental Study on the Effects of Corona Discharge on Methane Reactions

    NASA Astrophysics Data System (ADS)

    Marafee, Abdulathim M. J.

    The oxidative coupling of methane (OCM) is currently being actively studied for the production of higher hydrocarbons from natural gas. The present study concentrates on the oxidative conversion of methane in a high-pressure (one atmosphere), nonthermal plasma formed by corona discharge. Here, methyl radicals are formed by the reaction of methane with negatively-charged oxygen species created in the corona discharge. The results of methane conversion in the presence of both AC and DC corona discharges revealed that ethane and ethylene product selectivity is affected by electrode polarity, frequency, and oxygen partial pressure in the feed. Higher C_2 yields were obtained with the AC corona. All of the AC corona discharges specified here were initiated at room temperature (i.e., no oven or other heat source used), with temperature increases from 300 to 500^circC due to the exothermic gas discharge and exothermic reaction. A reaction mechanism is presented to explain the observed phenomena. The results suggest that AC and/or DC gas discharge techniques should be further studied for improved economics of methane conversion. The oxidative dehydrogenation of ethane in DC corona discharges was investigated. The atomic oxygen radicals initiated by corona discharges are thought to be active for the OXD of ethane. The selectivity to ethylene is affected by the reaction temperature, the DC applied voltage, voltage polarity, and the C_2H _6/O_2 ratio. The results of this study suggest the corona discharge process to be very efficient and selective in the oxidative dehydrogenation of ethane. The effects of DC corona discharge were examined in the presence of a typical OCM catalyst, Sr/La _2O_3. Experimental investigations have correspondingly been conducted, in which all reactive gases passed through a catalyst bed situated within the corona-induced plasma zone. The methane conversion and C_2 yield increased (with O_2 partial pressure) during the corona-enhanced catalytic

  7. Enhancing the specificity of the enterokinase cleavage reaction to promote efficient cleavage of a fusion tag.

    PubMed

    Shahravan, S Hesam; Qu, Xuanlu; Chan, I-San; Shin, Jumi A

    2008-06-01

    In our work with designed minimalist proteins based on the bZIP motif, we have found our His-tagged proteins to be prone to inclusion body formation and aggregation; we suspect this problem is largely due to the His tag, known to promote aggregation. Using AhR6-C/EBP, a hybrid of the AhR basic region and C/EBP leucine zipper, as representative of our bZIP-like protein family, we attempted removal of the His tag with enterokinase (EK) but obtained the desired cleavage product in very small yield. EK is known for proteolysis at noncanonical sites, and most cleavage occurred at unintended sites. We manipulated experimental conditions to improve specificity of proteolysis and analyzed the cleavage products; no effect was observed after changing pH, temperature, or the amount of EK. We then suspected the accessibility of the EK site was impeded due to protein aggregation. We found that the easily implemented strategy of addition of urea (1-4 M) greatly improved EK cleavage specificity at the canonical site and reduced adventitious cleavage. We believe that this enhancement in specificity is due to a more "open" protein structure, in which the now accessible canonical target can compete effectively with adventitious cleavage sites of related sequence.

  8. Enhanced formic acid electro-oxidation reaction on ternary Pd-Ir-Cu/C catalyst

    NASA Astrophysics Data System (ADS)

    Chen, Jinwei; Zhang, Jie; Jiang, Yiwu; Yang, Liu; Zhong, Jing; Wang, Gang; Wang, Ruilin

    2015-12-01

    Aim to further reduce the cost of Pd-Ir for formic acid electro-oxidation (FAEO), the Cu was used to construct a ternary metallic alloy catalyst. The prepared catalysts are characterized using XRD, TGA, EDX, TEM, XPS, CO-stripping, cyclic voltammetry and chronoamperometry. It is found that the Pd18Ir1Cu6 nanoparticles with a mean size of 3.3 nm are highly dispersed on carbon support. Componential distributions on catalyst are consistent with initial contents. Electrochemical measurements show that the PdIrCu/C catalyst exhibits the highest activity for FAEO. The mass activity of Pd in Pd18Ir1Cu6/C at 0.16 V (vs. SCE) is about 1.47, 1.62 and 2.08 times as high as that of Pd18Cu6/C, Pd18Ir1/C and Pd/C, respectively. The activity enhancement of PdIrCu/C should be attributed to the weakened CO adsorption strength and the removal of adsorbed intermediates at lower potential with the addition of Cu and Ir.

  9. Differences in microbial signatures between rectal mucosal biopsies and rectal swabs.

    PubMed

    Araújo-Pérez, Félix; McCoy, Amber N; Okechukwu, Charles; Carroll, Ian M; Smith, Kevin M; Jeremiah, Kim; Sandler, Robert S; Asher, Gary N; Keku, Temitope O

    2012-01-01

    There is growing evidence the microbiota of the large bowel may influence the risk of developing colorectal cancer as well as other diseases including type-1 diabetes, inflammatory bowel diseases and irritable bowel syndrome. Current sampling methods to obtain microbial specimens, such as feces and mucosal biopsies, are inconvenient and unappealing to patients. Obtaining samples through rectal swabs could prove to be a quicker and relatively easier method, but it is unclear if swabs are an adequate substitute. We compared bacterial diversity and composition from rectal swabs and rectal mucosal biopsies in order to examine the viability of rectal swabs as an alternative to biopsies. Paired rectal swabs and mucosal biopsy samples were collected in un-prepped participants (n = 11) and microbial diversity was characterized by Terminal Restriction Fragment Length polymorphism (T-RFLP) analysis and quantitative polymerase chain reaction (qPCR) of the 16S rRNA gene. Microbial community composition from swab samples was different from rectal mucosal biopsies (p = 0.001). Overall the bacterial diversity was higher in swab samples than in biopsies as assessed by diversity indexes such as: richness (p = 0.01), evenness (p = 0.06) and Shannon's diversity (p = 0.04). Analysis of specific bacterial groups by qPCR showed higher copy number of Lactobacillus (p < 0.0001) and Eubacteria (p = 0.0003) in swab samples compared with biopsies. Our findings suggest that rectal swabs and rectal mucosal samples provide different views of the microbiota in the large intestine.

  10. Pore-scale mechanisms for the enhancement of mixing in unsaturated porous media and implications for chemical reactions

    NASA Astrophysics Data System (ADS)

    Jiménez-Martínez, Joaquín.; Anna, Pietro de; Tabuteau, Hervé; Turuban, Régis; Borgne, Tanguy Le; Méheust, Yves

    2015-07-01

    Porous media in which different fluid phases coexist are common in nature (e.g., vadose zone and gas-oil reservoirs). In partially saturated porous media, the intricate spatial distributions of the wetting and nonwetting phases causes their flow to be focused onto preferential paths. Using a novel 2-D experimental setup allowing pore-scale measurement of concentration fields in a controlled unsaturated flow, we highlight mechanisms by which mixing of an invading fluid with the resident fluid is significantly enhanced when decreasing saturation. The mean scalar dissipation rate is observed to decrease slowly in time, while under saturated conditions it decays rapidly. This slow decrease is due to sustained longitudinal solute fingering, which causes concentration gradients to remain predominantly transverse to the average flow. Consequently, the effective reactivity is found to be much larger than under saturated conditions. These results provide new insights into the role that multiphase flows play on mixing/reaction in porous media.

  11. Palladium networks decorated by cuprous oxide for remarkably enhanced electrocatalytic activity of methanol oxidation reaction with high CO-tolerance

    NASA Astrophysics Data System (ADS)

    Ji, Yuanyuan; Ying, Ye; Pan, Yuxia; Li, Mengzhu; Guo, Xiaoyu; Wu, Yiping; Wen, Ying; Yang, Haifeng

    2016-10-01

    The CuO nanorods (NRs) are prepared with the help of inositol hexakisphosphate which serves as a binding agent and stabilizer. We have successfully fabricated Cu2O-decorated palladium networks (Cu2O/Pd Networks) by using such CuO NRs as reaction beds. Transmission electron microscopy images show that Cu2O/Pd network is composed of small and irregular fused nanoparticles with an average size of about 10 nm. Electrochemical results depict that the as-synthesized catalyst exhibits 2-fold higher activity for methanol oxidation than the commercially available 20% Pd/C catalyst and Pd black catalyst. Furthermore, CO-tolerance is also remarkably enhanced due to the presence of Cu2O. Such highly active, low-cost, and superiorly CO-tolerant catalysts of Cu2O/Pd Networks will open up a new avenue for direct methanol fuel cells.

  12. Electrochemical fabrication of platinum nanoflakes on fulleropyrrolidine nanosheets and their enhanced electrocatalytic activity and stability for methanol oxidation reaction

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Ma, Li-Xia

    2015-07-01

    Pyridine-functionalized fulleropyrrolidine nanosheets are prepared by a fast reprecipitation method under ultrasonication, and used as a novel nanostructured support materials to fabricate Pt catalyst nanoflakes by a simple electrodeposition approach. The as-prepared novel Pt-fullerene hybrid catalyst (Pt/PyC60) exhibits much enhanced electrocatalytic activity and stability for methanol oxidation reaction compared to the unsupported Pt nanoflakes and commercial Pt/C. The introduction of nanostructured fulleropyrrolidine as new support materials not only increases the electrochemically active surface area of catalyst, but also significantly improves the long-term stability. This will contribute to developing functionalized fullerenes as new nanostructured support materials for advanced electrocatalysts in fuel cells.

  13. Ultrathin Coating of Confined Pt Nanocatalysts by Atomic Layer Deposition for Enhanced Catalytic Performance in Hydrogenation Reactions.

    PubMed

    Wang, Meihua; Gao, Zhe; Zhang, Bin; Yang, Huimin; Qiao, Yan; Chen, Shuai; Ge, Huibin; Zhang, Jiankang; Qin, Yong

    2016-06-13

    Metal-support interfaces play a prominent role in heterogeneous catalysis. However, tailoring the metal-support interfaces to realize full utilization remains a major challenge. In this work, we propose a graceful strategy to maximize the metal-oxide interfaces by coating confined nanoparticles with an ultrathin oxide layer. This is achieved by sequential deposition of ultrathin Al2 O3 coats, Pt, and a thick Al2 O3 layer on carbon nanocoils templates by atomic layer deposition (ALD), followed by removal of the templates. Compared with the Pt catalysts confined in Al2 O3 nanotubes without the ultrathin coats, the ultrathin coated samples have larger Pt-Al2 O3 interfaces. The maximized interfaces significantly improve the activity and the protecting Al2 O3 nanotubes retain the stability for hydrogenation reactions of 4-nitrophenol. We believe that applying ALD ultrathin coats on confined catalysts is a promising way to achieve enhanced performance for other catalysts.

  14. Novel molybdenum disulfide nanosheets-decorated polyaniline: Preparation, characterization and enhanced electrocatalytic activity for hydrogen evolution reaction

    NASA Astrophysics Data System (ADS)

    Ding, Shuangshuang; He, Ping; Feng, Wanru; Li, Lian; Zhang, Guangli; Chen, Jingchao; Dong, Faqin; He, Huichao

    2016-04-01

    Novel molybdenum disulfide nanosheets-decorated polyaniline (MoS2/PANI) was synthesized and investigated as an efficient catalyst for hydrogen evolution reaction (HER). Compared with MoS2, MoS2/PANI nanocomposites exhibited higher catalytic activity and lower Tafel slope for HER in H2SO4 solution. The amount of 19 wt% PANI for coupling with MoS2 resulted in a high current density of 80 mA cm-2 at 400 mV (vs. RHE). In addition, the optimal MoS2/PANI nanocomposite showed impressive long-term stability even after 500 cycles. The enhanced catalytic activity of MoS2/PANI nanocomposites was primarily ascribed to the effective electron transport channels of PANI and the increase of electrochemically accessible surface area in composite materials, which was advantageous to facilitate the charge transfer at catalyst/electrolyte interface.

  15. Anti-ulcerogenic effect of banana powder (Musa sapientum var. paradisiaca) and its effect on mucosal resistance.

    PubMed

    Goel, R K; Gupta, S; Shankar, R; Sanyal, A K

    1986-10-01

    Orally administered banana pulp powder (Musa sapientum var. paradisiaca) was shown to have significant anti-ulcerogenic activity in rats subjected to aspirin, indomethacin, phenylbutazone, prednisolone and cysteamine and in guinea-pigs subjected to histamine. Banana powder not only increased mucosal thickness but also significantly increased [3H]thymidine incorporation into mucosal DNA. Relative to untreated control sections, histological studies showed that banana treatment increased staining by alcian blue in the apical cells with staining noted in the deeper layers of the mucosal glands. Banana-treated and control sections were also stained for DNA by the Feulgen reaction. The banana-treated sections showed a greater aggregation and intensity of pink spots when compared to controls. The present study suggests that banana powder treatment not only strengthens mucosal resistance against ulcerogens but also promotes healing by inducing cellular proliferation.

  16. On the reaction of D-amino acid oxidase with dioxygen: O2 diffusion pathways and enhancement of reactivity.

    PubMed

    Rosini, Elena; Molla, Gianluca; Ghisla, Sandro; Pollegioni, Loredano

    2011-02-01

    Evidence is accumulating that oxygen access in proteins is guided and controlled. We also have recently described channels that might allow access of oxygen to pockets at the active site of the flavoprotein D-amino acid oxidase (DAAO) that have a high affinity for dioxygen and are in close proximity to the flavin. With the goal of enhancing the reactivity of DAAO with oxygen, we have performed site-saturation mutagenesis at three positions that flank the putative oxygen channels and high-affinity sites. The most interesting variants at positions 50, 201 and 225 were identified by a screening procedure at low oxygen concentration. The biochemical properties of these variants have been studied and compared with those of wild-type DAAO, with emphasis on the reactivity of the reduced enzyme species with dioxygen. The substitutions at positions 50 and 225 do not enhance this reaction, but mainly affect the protein conformation and stability. However, the T201L variant shows an up to a threefold increase in the rate constant for reaction of O(2) with reduced flavin, together with a fivefold decrease in the K(m) for dioxygen. This effect was not observed when a valine is located at position 201, and is thus attributed to a specific alteration in the micro-environment of one high-affinity site for dioxygen (site B) close to the flavin that plays an important role in the storage of oxygen. The increase in O(2) reactivity observed for T201L DAAO is of great interest for designing new flavoenzymes for biotechnological applications.

  17. An NK Cell Perforin Response Elicited via IL-18 Controls Mucosal Inflammation Kinetics during Salmonella Gut Infection.

    PubMed

    Müller, Anna A; Dolowschiak, Tamas; Sellin, Mikael E; Felmy, Boas; Verbree, Carolin; Gadient, Sandra; Westermann, Alexander J; Vogel, Jörg; LeibundGut-Landmann, Salome; Hardt, Wolf-Dietrich

    2016-06-01

    Salmonella Typhimurium (S.Tm) is a common cause of self-limiting diarrhea. The mucosal inflammation is thought to arise from a standoff between the pathogen's virulence factors and the host's mucosal innate immune defenses, particularly the mucosal NAIP/NLRC4 inflammasome. However, it had remained unclear how this switches the gut from homeostasis to inflammation. This was studied using the streptomycin mouse model. S.Tm infections in knockout mice, cytokine inhibition and -injection experiments revealed that caspase-1 (not -11) dependent IL-18 is pivotal for inducing acute inflammation. IL-18 boosted NK cell chemoattractants and enhanced the NK cells' migratory capacity, thus promoting mucosal accumulation of mature, activated NK cells. NK cell depletion and Prf-/- ablation (but not granulocyte-depletion or T-cell deficiency) delayed tissue inflammation. Our data suggest an NK cell perforin response as one limiting factor in mounting gut mucosal inflammation. Thus, IL-18-elicited NK cell perforin responses seem to be critical for coordinating mucosal inflammation during early infection, when S.Tm strongly relies on virulence factors detectable by the inflammasome. This may have broad relevance for mucosal defense against microbial pathogens.

  18. An NK Cell Perforin Response Elicited via IL-18 Controls Mucosal Inflammation Kinetics during Salmonella Gut Infection

    PubMed Central

    Müller, Anna A.; Dolowschiak, Tamas; Sellin, Mikael E.; Felmy, Boas; Verbree, Carolin; Gadient, Sandra; Westermann, Alexander J.; Vogel, Jörg; LeibundGut-Landmann, Salome; Hardt, Wolf-Dietrich

    2016-01-01

    Salmonella Typhimurium (S.Tm) is a common cause of self-limiting diarrhea. The mucosal inflammation is thought to arise from a standoff between the pathogen's virulence factors and the host's mucosal innate immune defenses, particularly the mucosal NAIP/NLRC4 inflammasome. However, it had remained unclear how this switches the gut from homeostasis to inflammation. This was studied using the streptomycin mouse model. S.Tm infections in knockout mice, cytokine inhibition and –injection experiments revealed that caspase-1 (not -11) dependent IL-18 is pivotal for inducing acute inflammation. IL-18 boosted NK cell chemoattractants and enhanced the NK cells' migratory capacity, thus promoting mucosal accumulation of mature, activated NK cells. NK cell depletion and Prf-/- ablation (but not granulocyte-depletion or T-cell deficiency) delayed tissue inflammation. Our data suggest an NK cell perforin response as one limiting factor in mounting gut mucosal inflammation. Thus, IL-18-elicited NK cell perforin responses seem to be critical for coordinating mucosal inflammation during early infection, when S.Tm strongly relies on virulence factors detectable by the inflammasome. This may have broad relevance for mucosal defense against microbial pathogens. PMID:27341123

  19. Understanding the role of gold nanoparticles in enhancing the catalytic activity of manganese oxides in water oxidation reactions.

    PubMed

    Kuo, Chung-Hao; Li, Weikun; Pahalagedara, Lakshitha; El-Sawy, Abdelhamid M; Kriz, David; Genz, Nina; Guild, Curtis; Ressler, Thorsten; Suib, Steven L; He, Jie

    2015-02-16

    The Earth-abundant and inexpensive manganese oxides (MnOx) have emerged as an intriguing type of catalysts for the water oxidation reaction. However, the overall turnover frequencies of MnOx catalysts are still much lower than that of nanostructured IrO2 and RuO2 catalysts. Herein, we demonstrate that doping MnOx polymorphs with gold nanoparticles (AuNPs) can result in a strong enhancement of catalytic activity for the water oxidation reaction. It is observed that, for the first time, the catalytic activity of MnOx/AuNPs catalysts correlates strongly with the initial valence of the Mn centers. By promoting the formation of Mn(3+) species, a small amount of AuNPs (<5%) in α-MnO2/AuNP catalysts significantly improved the catalytic activity up to 8.2 times in the photochemical and 6 times in the electrochemical system, compared with the activity of pure α-MnO2.

  20. Enhanced autotrophic astaxanthin production from Haematococcus pluvialis under high temperature via heat stress-driven Haber-Weiss reaction.

    PubMed

    Hong, Min-Eui; Hwang, Sung Kwan; Chang, Won Seok; Kim, Byung Woo; Lee, Jeewon; Sim, Sang Jun

    2015-06-01

    High temperatures (30-36 °C) inhibited astaxanthin accumulation in Haematococcus pluvialis under photoautotrophic conditions. The depression of carotenogenesis was primarily attributed to excess intracellular less reactive oxygen species (LROS; O2 (-) and H2O2) levels generated under high temperature conditions. Here, we show that the heat stress-driven inefficient astaxanthin production was improved by accelerating the iron-catalyzed Haber-Weiss reaction to convert LROS into more reactive oxygen species (MROS; O2 and OH·), thereby facilitating lipid peroxidation. As a result, during 18 days of photoautotrophic induction, the astaxanthin concentration of cells cultured in high temperatures in the presence of iron (450 μM) was dramatically increased by 75 % (30 °C) and 133 % (36 °C) compared to that of cells exposed to heat stress alone. The heat stress-driven Haber-Weiss reaction will be useful for economically producing astaxanthin by reducing energy cost and enhancing photoautotrophic astaxanthin production, particularly outdoors utilizing natural solar radiation including heat and light for photo-induction of H. pluvialis.

  1. Humin as an electron donor for enhancement of multiple microbial reduction reactions with different redox potentials in a consortium.

    PubMed

    Zhang, Dongdong; Zhang, Chunfang; Xiao, Zhixing; Suzuki, Daisuke; Katayama, Arata

    2015-02-01

    A solid-phase humin, acting as an electron donor, was able to enhance multiple reductive biotransformations, including dechlorination of pentachlorophenol (PCP), dissimilatory reduction of amorphous Fe (III) oxide (FeOOH), and reduction of nitrate, in a consortium. Humin that was chemically reduced by NaBH4 served as an electron donor for these microbial reducing reactions, with electron donating capacities of 0.013 mmol e(-)/g for PCP dechlorination, 0.15 mmol e(-)/g for iron reduction, and 0.30 mmol e(-)/g for nitrate reduction. Two pairs of oxidation and reduction peaks within the humin were detected by cyclic voltammetry analysis. 16S rRNA gene sequencing-based microbial community analysis of the consortium incubated with different terminal electron acceptors, suggested that Dehalobacter sp., Bacteroides sp., and Sulfurospirillum sp. were involved in the PCP dechlorination, dissimilatory iron reduction, and nitrate reduction, respectively. These findings suggested that humin functioned as a versatile redox mediator, donating electrons for multiple respiration reactions with different redox potentials.

  2. Monitoring the inorganic chemical reaction by surface-enhanced Raman spectroscopy: A case of Fe³⁺ to Fe²⁺ conversion.

    PubMed

    Qin, Suhua; Meng, Juan; Tang, Xianghu; Yang, Liangbao

    2016-01-01

    Monitoring the process of organic chemical reactions to study the kinetics by surface-enhanced Raman spectroscopy (SERS) is currently of immense interest. However, monitoring the inorganic chemical reaction is still an extremely difficulty for researchers. This study exactly focused on the monitor of inorganic chemical reaction. Capillary coated with silver nanoparticles was introduced, which was an efficient platform for monitoring reactions with SERS due to the advantages of sensitivity and excellent reproducibility. The photoreduction of [Fe(phen)3](3+) to [Fe(phen)3](2+) was used as model reaction to demonstrated the feasibility of SERS monitoring inorganic chemical reaction by involving in metal-organic complexes. Moreover, the preliminary implementation demonstrated that the kinetics of photoreduction can be real-time monitored by in situ using the SERS technique on a single constructed capillary, which may be useful for the practical application of SERS technique.

  3. Prospective Evaluation to Establish a Dose Response for Clinical Oral Mucositis in Patients Undergoing Head-and-Neck Conformal Radiotherapy

    SciTech Connect

    Narayan, Samir Lehmann, Joerg; Coleman, Matthew A.; Vaughan, Andrew; Yang, Claus Chunli; Enepekides, Danny; Farwell, Gregory; Purdy, James A.; Laredo, Grace; Nolan, Kerry A.S.; Pearson, Francesca S.; Vijayakumar, Srinivasan

    2008-11-01

    Purpose: We conducted a clinical study to correlate oral cavity dose with clinical mucositis, perform in vivo dosimetry, and determine the feasibility of obtaining buccal mucosal cell samples in patients undergoing head-and-neck radiation therapy. The main objective is to establish a quantitative dose response for clinical oral mucositis. Methods and Materials: Twelve patients undergoing radiation therapy for head-and-neck cancer were prospectively studied. Four points were chosen in separate quadrants of the oral cavity. Calculated dose distributions were generated by using AcQPlan and Eclipse treatment planning systems. MOSFET dosimeters were used to measure dose at each sampled point. Each patient underwent buccal sampling for future RNA analysis before and after the first radiation treatment at the four selected points. Clinical and functional mucositis were assessed weekly according to National Cancer Institute Common Toxicity Criteria, Version 3. Results: Maximum and average doses for sampled sites ranged from 7.4-62.3 and 3.0-54.3 Gy, respectively. A cumulative point dose of 39.1 Gy resulted in mucositis for 3 weeks or longer. Mild severity (Grade {<=} 1) and short duration ({<=}1 week) of mucositis were found at cumulative point doses less than 32 Gy. Polymerase chain reaction consistently was able to detect basal levels of two known radiation responsive genes. Conclusions: In our sample, cumulative doses to the oral cavity of less than 32 Gy were associated with minimal acute mucositis. A dose greater than 39 Gy was associated with longer duration of mucositis. Our technique for sampling buccal mucosa yielded sufficient cells for RNA analysis using polymerase chain reaction.

  4. NanoPCR observation: different levels of DNA replication fidelity in nanoparticle-enhanced polymerase chain reactions

    NASA Astrophysics Data System (ADS)

    Shen, Cenchao; Yang, Wenjuan; Ji, Qiaoli; Maki, Hisaji; Dong, Anjie; Zhang, Zhizhou

    2009-11-01

    Nanoparticle-assisted PCR (polymerase chain reaction) technology is getting more and more attention recently. It is believed that some of the DNA recombinant technologies will be upgraded by nanotechnology in the near future, among which DNA replication is one of the core manipulation techniques. So whether or not the DNA replication fidelity is compromised in nanoparticle-assisted PCR is a question. In this study, a total of 16 different metallic and non-metallic nanoparticles (NPs) were tested for their effects on DNA replication fidelity in vitro and in vivo. Sixteen types of nanomaterials were distinctly different in enhancing the PCR efficiency, and their relative capacity to retain DNA replication fidelity was largely different from each other based on rpsL gene mutation assay. Generally speaking, metallic nanoparticles induced larger error rates in DNA replication fidelity than non-metallic nanoparticles, and non-metallic nanomaterials such as carbon nanopowder or nanotubes were still safe as PCR enhancers because they did not compromise the DNA replication fidelity in the Taq DNA polymerase-based PCR system.

  5. NanoPCR observation: different levels of DNA replication fidelity in nanoparticle-enhanced polymerase chain reactions.

    PubMed

    Shen, Cenchao; Yang, Wenjuan; Ji, Qiaoli; Maki, Hisaji; Dong, Anjie; Zhang, Zhizhou

    2009-11-11

    Nanoparticle-assisted PCR (polymerase chain reaction) technology is getting more and more attention recently. It is believed that some of the DNA recombinant technologies will be upgraded by nanotechnology in the near future, among which DNA replication is one of the core manipulation techniques. So whether or not the DNA replication fidelity is compromised in nanoparticle-assisted PCR is a question. In this study, a total of 16 different metallic and non-metallic nanoparticles (NPs) were tested for their effects on DNA replication fidelity in vitro and in vivo. Sixteen types of nanomaterials were distinctly different in enhancing the PCR efficiency, and their relative capacity to retain DNA replication fidelity was largely different from each other based on rpsL gene mutation assay. Generally speaking, metallic nanoparticles induced larger error rates in DNA replication fidelity than non-metallic nanoparticles, and non-metallic nanomaterials such as carbon nanopowder or nanotubes were still safe as PCR enhancers because they did not compromise the DNA replication fidelity in the Taq DNA polymerase-based PCR system.

  6. Mucosal Immunity and Candida albicans Infection

    PubMed Central

    Moyes, David L.; Naglik, Julian R.

    2011-01-01

    Interactions between mucosal surfaces and microbial microbiota are key to host defense, health, and disease. These surfaces are exposed to high numbers of microbes and must be capable of distinguishing between those that are beneficial or avirulent and those that will invade and cause disease. Our understanding of the mechanisms involved in these discriminatory processes has recently begun to expand as new studies bring to light the importance of epithelial cells and novel immune cell subsets such as Th17 T cells in these processes. Elucidating how these mechanisms function will improve our understanding of many diverse diseases and improve our ability to treat patients suffering from these conditions. In our voyage to discover these mechanisms, mucosal interactions with opportunistic commensal organisms such as the fungus Candida albicans provide insights that are invaluable. Here, we review current knowledge of the interactions between C. albicans and epithelial surfaces and how this may shape our understanding of microbial-mucosal interactions. PMID:21776285

  7. C. albicans Colonization of Human Mucosal Surfaces

    PubMed Central

    Southern, Peter; Horbul, Julie; Maher, Diane; Davis, Dana A.

    2008-01-01

    Background Candida albicans is a low level commensal organism in normal human populations with the continuous potential to expand and cause a spectrum of clinical conditions. Methodology/Principal Findings Using ex vivo human organ cultures and populations of primary human cells, we have developed several related experimental systems to examine early-stage interactions between C. albicans and mucosal surfaces. Experiments have been conducted both with exogenously added C. albicans and with overtly normal human mucosal surfaces supporting pre-existing infections with natural isolates of Candida. Under different culture conditions, we have demonstrated the formation of C. albicans colonies on human target cells and filament formation, equivalent to tissue invasion. Conclusions/Significance These organ culture systems provide a valuable new resource to examine the molecular and cellular basis for Candida colonization of human mucosal surfaces. PMID:18446191

  8. Induction of mucosal and systemic antibody and T-cell responses following prime–boost immunization with novel adjuvanted human immunodeficiency virus-1-vaccine formulations

    PubMed Central

    Cristillo, Anthony D.; Ferrari, Maria Grazia; Hudacik, Lauren; Lewis, Brad; Galmin, Lindsey; Bowen, Britany; Thompson, DeVon; Petrovsky, Nikolai; Markham, Phillip; Pal, Ranajit

    2011-01-01

    As sexual transmission of human immunodeficiency virus-1 (HIV-1) occurs via the mucosa, an ideal HIV-1 vaccine should induce both mucosal and systemic immunity. We therefore sought to evaluate the induction of mucosal responses using a DNA env prime–gp120 protein boost approach in which sequential nasal and parenteral protein administration was performed with two novel carbohydrate-based adjuvants. These adjuvants, Advax-M and Advax-P, were specifically designed for mucosal and systemic immune enhancement, respectively. Murine intranasal immunization with gp120/Advax-M adjuvant elicited gp120-specific IgA in serum and mucosal secretions that was markedly enhanced by DNA priming. Boosting of DNA-primed mice with gp120/Advax-M and gp120/Advax-P by sequential intranasal and intramuscular immunization, or vice versa, elicited persistent mucosal gp120-specific IgA, systemic IgG and memory T- and B-cell responses. Induction of homologous, but not heterologous, neutralizing activity was noted in the sera of all immunized groups. While confirmation of efficacy is required in challenge studies using non-human primates, these results suggest that the combination of DNA priming with sequential nasal and parenteral protein boosting, with appropriate mucosal and systemic adjuvants, could generate strong mucosal and systemic immunity and may block HIV-1 mucosal transmission and infection. PMID:21169215

  9. Oral mucosal diseases: evaluation and management.

    PubMed

    Stoopler, Eric T; Sollecito, Thomas P

    2014-11-01

    Oral mucosal diseases encompass several common conditions that affect the general population. Some of these disorders present with signs and symptoms that are pathognomonic for the condition, whereas others present with similar features that can make clinical diagnosis difficult to achieve. It is important for physicians to have a clear understanding of these disorders to provide appropriate care to patients. This article reviews clinical aspects of common oral mucosal disorders, including candidiasis, herpes simplex viral infections, aphthous stomatitis, lichen planus, pemphigus vulgaris, and mucous membrane pemphigoid.

  10. Suppression of gastric mucosal inflammatory responses to Helicobacter pylori lipopolysaccharide by sulglycotide.

    PubMed

    Slomiany, B L; Piotrowski, J; Slomiany, A

    1999-02-01

    The effect of the antiulcer agent sulglycotide on gastric epithelial cell apoptosis and the expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) during Helicobacter pylori lipopolysaccharide-induced acute gastritis was investigated. Rats, pretreated twice daily for 3 consecutive days with sulglycotide at 200 mg/kg or vehicle, were subjected to surface epithelial application of H. pylori lipopolysaccharide (50 microg/animal), and, after 4 additional days on the drug or vehicle regimen, their mucosal tissue was used for histologic assessment, quantitation of TNF-alpha and IL-4, and the assay of epithelial cell apoptosis. In the absence of sulglycotide, H. pylori lipopolysaccharide caused acute mucosal responses manifested by the inflammatory infiltration of the lamina propria with lymphocytes and plasma cells, edema, hyperemia, and epithelial hemorrhage. These responses were accompanied by an 11-fold increase in epithelial cell apoptosis and a 9-fold enhancement of the mucosal expression of proinflammatory cytokine TNF-alpha. However, the mucosal expression of regulatory cytokine IL-4 decreased by 15%. Treatment with sulglycotide produced significant (56.6%) reduction in the extent of acute mucosal inflammatory changes caused by H. pylori lipopolysaccharide. Moreover, the effect of sulglycotide was manifested in an 88.3% reduction in the epithelial cell apoptosis and a 69.1% decrease in the mucosal expression of TNF-alpha, whereas the expression of IL-4 showed only marginal (6%) enhancement. The results suggest that the cytoprotective agent sulglycotide suppresses the inflammatory and apoptotic events elicited in gastric mucosa by H. pylori lipopolysaccharide through stimulation of TNF-alpha expression.

  11. Enteric glia promote intestinal mucosal healing via activation of focal adhesion kinase and release of proEGF

    PubMed Central

    Van Landeghem, Laurianne; Chevalier, Julien; Mahé, Maxime M.; Wedel, Thilo; Urvil, Petri; Derkinderen, Pascal; Savidge, Tor

    2011-01-01

    Wound healing of the gastrointestinal mucosa is essential for the maintenance of gut homeostasis and integrity. Enteric glial cells play a major role in regulating intestinal barrier function, but their role in mucosal barrier repair remains unknown. The impact of conditional ablation of enteric glia on dextran sodium sulfate (DSS)-induced mucosal damage and on healing of diclofenac-induced mucosal ulcerations was evaluated in vivo in GFAP-HSVtk transgenic mice. A mechanically induced model of intestinal wound healing was developed to study glial-induced epithelial restitution. Glial-epithelial signaling mechanisms were analyzed by using pharmacological inhibitors, neutralizing antibodies, and genetically engineered intestinal epithelial cells. Enteric glial cells were shown to be abundant in the gut mucosa, where they associate closely with intestinal epithelial cells as a distinct cell population from myofibroblasts. Conditional ablation of enteric glia worsened mucosal damage after DSS treatment and significantly delayed mucosal wound healing following diclofenac-induced small intestinal enteropathy in transgenic mice. Enteric glial cells enhanced epithelial restitution and cell spreading in vitro. These enhanced repair processes were reproduced by use of glial-conditioned media, and soluble proEGF was identified as a secreted glial mediator leading to consecutive activation of epidermal growth factor receptor and focal adhesion kinase signaling pathways in intestinal epithelial cells. Our study shows that enteric glia represent a functionally important cellular component of the intestinal epithelial barrier microenvironment and that the disruption of this cellular network attenuates the mucosal healing process. PMID:21350188

  12. Enhanced electrocatalytic activity of MoS(x) on TCNQ-treated electrode for hydrogen evolution reaction.

    PubMed

    Chang, Yung-Huang; Nikam, Revannath D; Lin, Cheng-Te; Huang, Jing-Kai; Tseng, Chien-Chih; Hsu, Chang-Lung; Cheng, Chia-Chin; Su, Ching-Yuan; Li, Lain-Jong; Chua, Daniel H C

    2014-10-22

    Molybdenum sulfide has recently attracted much attention because of its low cost and excellent catalytical effects in the application of hydrogen evolution reaction (HER). To improve the HER efficiency, many researchers have extensively explored various avenues such as material modification, forming hybrid structures or modifying geometric morphology. In this work, we reported a significant enhancement in the electrocatalytic activity of the MoSx via growing on Tetracyanoquinodimethane (TCNQ) treated carbon cloth, where the MoSx was synthesized by thermolysis from the ammonium tetrathiomolybdate ((NH4)2MoS4) precursor at 170 °C. The pyridinic N- and graphitic N-like species on the surface of carbon cloth arising from the TCNQ treatment facilitate the formation of Mo(5+) and S2(2-) species in the MoSx, especially with S2(2-) serving as an active site for HER. In addition, the smaller particle size of the MoSx grown on TCNQ-treated carbon cloth reveals a high ratio of edge sites relative to basal plane sites, indicating the richer effective reaction sites and superior electrocatalytic characteristics. Hence, we reported a high hydrogen evolution rate for MoSx on TCNQ-treated carbon cloth of 6408 mL g(-1) cm(-2) h(-1) (286 mmol g(-1) cm(-2) h(-1)) at an overpotential of V = 0.2 V. This study provides the fundamental concepts useful in the design and preparation of transition metal dichalcogenide catalysts, beneficial in the development in clean energy.

  13. Detection of deoxyribonucleic acid (DNA) targets using polymerase chain reaction (PCR) and paper surface-enhanced Raman spectroscopy (SERS) chromatography.

    PubMed

    Hoppmann, Eric P; Yu, Wei W; White, Ian M

    2014-01-01

    Surface-enhanced Raman spectroscopy (SERS) enables multiplex detection of analytes using simple, portable equipment consisting of a single excitation source and detector. Thus, in theory, SERS is ideally suited to replace fluorescence in assays that screen for numerous deoxyribonucleic acid (DNA) targets, but in practice, SERS-based assays have suffered from complexity and elaborate processing steps. Here, we report an assay in which a simple inkjet-fabricated plasmonic paper device enables SERS-based detection of multiple DNA targets within a single polymerase chain reaction (PCR). In prior work, we demonstrated the principles of chromatographic separation and SERS-based detection on inkjet-fabricated plasmonic paper. The present work extends that capability for post-PCR gene sequence detection. In this design, hydrolysis DNA probes with 5' Raman labels are utilized; if the target is present, the probe is hydrolyzed during PCR, freeing the reporter. After applying the PCR sample to a paper SERS device, an on-device chromatographic separation and concentration is conducted to discriminate between hydrolyzed and intact probes. SERS is then used to detect the reporter released by the hydrolyzed probes. This simple separation and detection on paper eliminates the need for complex sample processing steps. In this work, we simultaneously detect the methicillin-resistant Staphylococcus aureus genes mecA and femB to illustrate the concept. We envision that this approach could contribute to the development of multiplex DNA diagnostic tests enabling screening for several target sequences within a single reaction, which is necessary for cases in which sample volume and resources are limited.

  14. Bifunctional Ag@SiO 2 /Au Nanoparticles for Probing Sequential Catalytic Reactions by Surface-Enhanced Raman Spectroscopy

    DOE PAGES

    Wu, Yiren; Su, Dong; Qin, Dong

    2017-02-22

    Here, we report the synthesis of bifunctional Ag@SiO2/Au nanoparticles with an “islands in the sea” configuration by titrating HAuCl4 solution into an aqueous suspension of Ag@SiO2 core–shell nanocubes in the presence of NaOH, ascorbic acid, and poly(vinyl pyrrolidone) at pH 11.9. The NaOH plays an essential role in generating small pores in the SiO2 shell in situ, followed by the epitaxial deposition of Au from the Ag surface through the pores, leading to the formation of Au islands (6–12 nm in size) immersed in a SiO2 sea. Furthermore, by controlling the amount of HAuCl4 titrated into the reaction system, themore » Au islands can be made to pass through and protrude from the SiO2 shell, embracing catalytic activity toward the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. And while the Ag in the core provides a strong surface-enhanced Raman scattering activity, the SiO2 sea helps maintain the Au component as compact, isolated, and stabilized islands. The Ag@SiO2/Au nanoparticles can serve as a bifunctional probe to monitor the stepwise Au-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by NaBH4 and Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4'-dimercaptoazobenzene by the O2 from air in the same reaction system.« less

  15. Rice seed for delivery of vaccines to gut mucosal immune tissues.

    PubMed

    Takaiwa, Fumio; Wakasa, Yuhya; Takagi, Hidenori; Hiroi, Takachika

    2015-10-01

    Gut-associated lymphoid tissue (GALT) is the biggest lymphoid organ in the body. It plays a role in robust immune responses against invading pathogens while maintaining immune tolerance against nonpathogenic antigens such as foods. Oral vaccination can induce mucosal and systemic antigen-specific immune reactions and has several advantages including ease of administration, no requirement for purification and ease of scale-up of antigen. Thus far, taking advantage of these properties, various plant-based oral vaccines have been developed. Seeds provide a superior production platform over other plant tissues for oral vaccines; they offer a suitable delivery vehicle to GALT due to their high stability at room temperature, ample and stable deposition space, high expression level, and protection from digestive enzymes in gut. A rice seed production system for oral vaccines was established by combining stable deposition in protein bodies or protein storage vacuoles and enhanced endosperm-specific expression. Various types of rice-based oral vaccines for infectious and allergic diseases were generated. Efficacy of these rice-based vaccines was evaluated in animal models.

  16. Pulsed Laser-Assisted Focused Electron-Beam-Induced Etching of Titanium with XeF 2 : Enhanced Reaction Rate and Precursor Transport

    SciTech Connect

    Noh, J. H.; Fowlkes, J. D.; Timilsina, R.; Stanford, M. G.; Lewis, B. B.; Rack, P. D.

    2015-01-28

    We introduce a laser-assisted focused electron-beam-induced etching (LA-FEBIE) process which is a versatile, direct write nanofabrication method that allows nanoscale patterning and editing; we do this in order to enhance the etch rate of electron-beam-induced etching. The results demonstrate that the titanium electron stimulated etch rate via the XeF2 precursor can be enhanced up to a factor of 6 times with an intermittent pulsed laser assist. Moreover, the evolution of the etching process is correlated to in situ stage current measurements and scanning electron micrographs as a function of time. Finally, the increased etch rate is attributed to photothermally enhanced Ti–F reaction and TiF4 desorption and in some regimes enhanced XeF2 surface diffusion to the reaction zone.

  17. Pulsed laser-assisted focused electron-beam-induced etching of titanium with XeF2: enhanced reaction rate and precursor transport.

    PubMed

    Noh, J H; Fowlkes, J D; Timilsina, R; Stanford, M G; Lewis, B B; Rack, P D

    2015-02-25

    In order to enhance the etch rate of electron-beam-induced etching, we introduce a laser-assisted focused electron-beam-induced etching (LA-FEBIE) process which is a versatile, direct write nanofabrication method that allows nanoscale patterning and editing. The results demonstrate that the titanium electron stimulated etch rate via the XeF2 precursor can be enhanced up to a factor of 6 times with an intermittent pulsed laser assist. The evolution of the etching process is correlated to in situ stage current measurements and scanning electron micrographs as a function of time. The increased etch rate is attributed to photothermally enhanced Ti-F reaction and TiF4 desorption and in some regimes enhanced XeF2 surface diffusion to the reaction zone.

  18. Origin of Enhanced Reactivity of a Microsolvated Nucleophile in Ion Pair SN2 Reactions: The Cases of Sodium p-Nitrophenoxide with Halomethanes in Acetone.

    PubMed

    Li, Qiang-Gen; Xu, Ke; Ren, Yi

    2015-04-30

    In a kinetic experiment on the SN2 reaction of sodium p-nitrophenoxide with iodomethane in acetone-water mixed solvent, Humeres et al. (J. Org. Chem. 2001, 66, 1163) found that the reaction depends strongly on the medium, and the fastest rate constant was observed in pure acetone. The present work tries to explore why acetone can enhance the reactivity of the title reactions. Accordingly, we make a mechanistic study on the reactions of sodium p-nitrophenoxide with halomethanes (CH3X, X = Cl, Br, I) in acetone by using a supramolecular/continuum model at the PCM-MP2/6-311+G(d,p)//B3LYP/6-311+G(d,p) level, in which the ion pair nucleophile is microsolvated by one to three acetone molecules. We compared the reactivity of the microsolvated ion pair nucleophiles with solvent-free ion pair and anionic ones. Our results clearly reveal that the microsolvated ion pair nucleophile is favorable for the SN2 reactions; meanwhile, the origin of the enhanced reactivity induced by microsolvation of the nucleophile is discussed in terms of the geometries of transition state (TS) structures and activation strain model, suggesting that lower deformation energies and stronger interaction energies between the deformed reactants in the TS lead to the lower overall reaction barriers for the SN2 reaction of microsolvated sodium p-nitrophenoxide toward halomethanes in acetone.

  19. Concomitant early mucosal and cutaneous leishmaniasis in Brazil.

    PubMed

    Boaventura, Viviane S; Cafe, Virginia; Costa, Jackson; Oliveira, Fabiano; Bafica, Andre; Rosato, Andrea; de Freitas, Luiz A R; Brodskyn, Claudia; Barral-Netto, Manoel; Barral, Aldina

    2006-08-01

    Mucosal leishmaniasis (ML) is often clinically silent until reaching a highly advanced state. In this prospective study, 6 of 220 patients with early cutaneous leishmaniasis were diagnosed with mucosal involvement by otorhinolaryngological examination (a rate similar to the reported rate of late ML). Detection of early ML may represent an important strategy in preventing severe mucosal destruction in human leishmaniasis.

  20. Mucosal melanoma of the head and neck.

    PubMed

    Ascierto, Paolo Antonio; Accorona, Remo; Botti, Gerardo; Farina, Davide; Fossati, Piero; Gatta, Gemma; Gogas, Helen; Lombardi, Davide; Maroldi, Roberto; Nicolai, Piero; Ravanelli, Marco; Vanella, Vito

    2017-04-01

    Mucosal melanoma of the head and neck is a very rare and aggressive malignancy with a very poor prognosis. The nasal cavity, paranasal sinuses, and oral cavity are the most common locations. One-, 3- and 5-year survival rates between 2000 and 2007 were 63%, 30% and 20%, respectively. Cigarette smoking seems to be a risk factor even though the evidence for this is very low. Clinical signs and symptoms are usually nonspecific. While surgery is considered the mainstay of treatment for most mucosal melanomas of the head and neck region, radiotherapy has a role in local control of the disease after surgery. Many new treatment options in the last years, in particular targeted therapies (i.e. inhibitors of c-KIT, NRAS/MEK or BRAF) and immunotherapies (anti CTLA-4 and anti PD-1/PD-L1 antibodies), have changed the history of cutaneous melanoma. Despite the different biology, mucosal melanoma is currently treated in the same way as cutaneous melanoma; however, patients with mucosal melanoma were excluded from the majority of recent clinical trials. Recent molecular findings offer new hope for the development of more effective systemic therapy.

  1. Characterization of Mucosal Candida albicans Biofilms

    PubMed Central

    Dongari-Bagtzoglou, Anna; Kashleva, Helena; Dwivedi, Prabhat; Diaz, Patricia; Vasilakos, John

    2009-01-01

    C. albicans triggers recurrent infections of the alimentary tract mucosa that result from biofilm growth. Although the ability of C. albicans to form a biofilm on abiotic surfaces has been well documented in recent years, no information exists on biofilms that form directly on mucosal surfaces. The objectives of this study were to characterize the structure and composition of Candida biofilms forming on the oral mucosa. We found that oral Candida biofilms consist of yeast, hyphae, and commensal bacteria, with keratin dispersed in the intercellular spaces. Neutrophils migrate through the oral mucosa and form nests within the biofilm mass. The cell wall polysaccharide β-glucan is exposed during mucosal biofilm growth and is more uniformly present on the surface of biofilm organisms invading the oral mucosa. We conclude that C. albicans forms complex mucosal biofilms consisting of both commensal bacterial flora and host components. These discoveries are important since they can prompt a shift of focus for current research in investigating the role of Candida-bacterial interactions in the pathogenesis of mucosal infections as well as the role of β-glucan mediated signaling in the host response. PMID:19956771

  2. RT3D Reaction Modules for Natural and Enhanced Attenuation of Chloroethanes, Chloroethenes, Chloromethanes, and Daughter Products

    SciTech Connect

    Johnson, Christian D.; Truex, Michael J.

    2006-07-25

    This document describes a suite of MNA/EA reaction modules that were developed for addressing complex chlorinated solvent reactions using RT3D. As an introduction, an overview of these MNA/EA reaction modules is presented, including discussions of similarities between reaction modules, the purpose of key reaction parameters, and important considerations for using the reaction modules. Subsequent sections provide the details of the reaction kinetics (conceptual model and equations), data input requirements, and example (batch reactor) results for each reaction module. This document does not discuss reaction module implementation or validation; such information will accompany the software in the form of release notes or a supplement to the RT3D manual.

  3. Cyclic GMP-AMP Displays Mucosal Adjuvant Activity in Mice

    PubMed Central

    Škrnjug, Ivana

    2014-01-01

    The recently discovered mammalian enzyme cyclic GMP-AMP synthase produces cyclic GMP-AMP (cGAMP) after being activated by pathogen-derived cytosolic double stranded DNA. The product can stimulate STING-dependent interferon type I signaling. Here, we explore the efficacy of cGAMP as a mucosal adjuvant in mice. We show that cGAMP can enhance the adaptive immune response to the model antigen ovalbumin. It promotes antigen specific IgG and a balanced Th1/Th2 lymphocyte response in immunized mice. A characteristic of the cGAMP-induced immune response is the slightly reduced induction of interleukin-17 as a hallmark of Th17 activity – a distinct feature that is not observed with other cyclic di-nucleotide adjuvants. We further characterize the innate immune stimulation activity in vitro on murine bone marrow-derived dendritic cells and human dendritic cells. The observed results suggest the consideration of cGAMP as a candidate mucosal adjuvant for human vaccines. PMID:25295996

  4. Augmenting light coverage for photosynthesis through YFP-enhanced charge separation at the Rhodobacter sphaeroides reaction centre

    DOE PAGES

    Grayson, Katie J.; Faries, Kaitlyn M.; Huang, Xia; ...

    2017-01-05

    Photosynthesis uses a limited range of the solar spectrum, so enhancing spectral coverage could improve the efficiency of light capture. Here, we show that a hybrid reaction centre (RC)/yellow fluorescent protein (YFP) complex accelerates photosynthetic growth in the bacterium Rhodobacter sphaeroides. The structure of the RC/YFP-light-harvesting 1 (LH1) complex shows the position of YFP attachment to the RC-H subunit, on the cytoplasmic side of the RC complex. Fluorescence lifetime microscopy of whole cells and ultrafast transient absorption spectroscopy of purified RC/YFP complexes show that the YFP–RC intermolecular distance and spectral overlap between the emission of YFP and the visible-region (QX)more » absorption bands of the RC allow energy transfer via a Fo¨rster mechanism, with an efficiency of 40±10%. Finally, this proof-of-principle study demonstrates the feasibility of increasing spectral coverage for harvesting light using non-native genetically-encoded light-absorbers, thereby augmenting energy transfer and trapping in photosynthesis.« less

  5. Sensitive electrochemical immunoassay with signal enhancement based on nanogold-encapsulated poly(amidoamine) dendrimer-stimulated hydrogen evolution reaction.

    PubMed

    Sun, Ai-Li

    2015-12-07

    A new electrochemical immunosensor with signal enhancement was designed for sensitive detection of disease-related protein (human carbohydrate antigen 19-9, CA 19-9 used in this case). The assay was carried out on a capture antibody-modified screen-printed carbon electrode with a sandwich-type mode by using detection antibody-functionalized nanogold-encapsulated poly(amidoamine) dendrimer (AuNP-PAAD). The AuNP-PAAD was first synthesized through the in situ reduction method and functionalized with the polyclonal rabbit anti-human CA 19-9 antibody. Upon target CA 19-9 introduction, a sandwiched immunocomplex could be formed between the capture antibody and detection antibody. Accompanying the AuNP-PAAD, the electrocatalytic activity of the carried gold nanoparticles toward the hydrogen evolution reaction (HER) allowed the rapid quantification of the target analyte on the electrode. The amplified electrochemical signal mainly derived from AuNP-catalyzed HER in an acidic medium. Under optimal conditions, the immuno-HER assay displayed a wide dynamic concentration range from 0.01 to 300 U mL(-1) toward target CA 19-9 with a detection limit (LOD) of 6.3 mU mL(-1). The reproducibility, precision, specificity and stability of our strategy were acceptable. Additionally, the system was further validated by assaying 13 human serum specimens, giving well matched results obtained from the commercialized enzyme-linked immunosorbent assay (ELISA) method.

  6. Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

    DOE PAGES

    Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; ...

    2015-06-24

    The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ionmore » injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.« less

  7. Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

    SciTech Connect

    Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; Moore, Ronald J.; Ibrahim, Yehia M.; Smith, Richard D.

    2015-06-24

    The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ion injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.

  8. Non-histone chromosomal proteins HMG1 and 2 enhance ligation reaction of DNA double-strand breaks.

    PubMed

    Nagaki, S; Yamamoto, M; Yumoto, Y; Shirakawa, H; Yoshida, M; Teraoka, H

    1998-05-08

    DNA ligase IV in a complex with XRCC4 is responsible for DNA end-joining in repair of DNA double-strand breaks (DSB) and V(D)J recombination. We found that non-histone chromosomal high mobility group (HMG) proteins 1 and 2 enhanced the ligation of linearized pUC119 DNA with DNA ligase IV from rat liver nuclear extract. Intra-molecular and inter-molecular ligations of cohesive-ended and blunt-ended DNA were markedly stimulated by HMG1 and 2. Recombinant HMG2-domain A, B, and (A + B) polypeptides were similarly, but non-identically, effective for the stimulation of DSB ligation reaction. Ligation of single-strand breaks (nicks) was only slightly activated by the HMG proteins. The DNA end-binding Ku protein singly or in combination with the catalytic component of DNA-dependent protein kinase (DNA-PK) as the DNA-PK holoenzyme was ineffective for the ligation of linearized pUC119 DNA. Although the stimulatory effect of HMG1 and 2 on ligation of DSB in vitro was not specific to DNA ligase IV, these results suggest that HMG1 and 2 are involved in the final ligation step in DNA end-joining processes of DSB repair and V(D)J recombination.

  9. A simple synthesis method for nanostructured Co-WC/carbon composites with enhanced oxygen reduction reaction activity

    PubMed Central

    Kang, Jun; Kim, Hye-min; Saito, Nagahiro; Lee, Myeong-Hoon

    2016-01-01

    Abstract Co nanoparticles (Co NPs) and nanoscale tungsten carbide (WC) are successfully synthesized simultaneously with mesoporous structured carbon black (C) using an innovative simple method, which is known as solution plasma processing (SPP), and NPs are also loaded onto carbon black at the same time by SPP. The introduction of Co NPs led to not only superior oxygen reduction reaction (ORR) activity in terms of onset potential and peak potential, but also to a more efficient electron transfer process compared to that of pure WC. Co-WC/C also showed durability for long-term operation better than that of commercial Pt/C. These results clearly demonstrate that the presence of Co NPs significantly enhanced the ORR and charge transfer number of neighboring WC NPs in ORR activities. In addition, it was proved that SPP is a simple method (from synthesis of NPs and carbon black to loading on carbon black) for the large-scale synthesis of NP-carbon composite. Therefore, SPP holds great potential as a candidate for next-generation synthetic methods for the production of NP-carbon composites. PMID:27877856

  10. Augmenting light coverage for photosynthesis through YFP-enhanced charge separation at the Rhodobacter sphaeroides reaction centre

    NASA Astrophysics Data System (ADS)

    Grayson, Katie J.; Faries, Kaitlyn M.; Huang, Xia; Qian, Pu; Dilbeck, Preston; Martin, Elizabeth C.; Hitchcock, Andrew; Vasilev, Cvetelin; Yuen, Jonathan M.; Niedzwiedzki, Dariusz M.; Leggett, Graham J.; Holten, Dewey; Kirmaier, Christine; Neil Hunter, C.

    2017-01-01

    Photosynthesis uses a limited range of the solar spectrum, so enhancing spectral coverage could improve the efficiency of light capture. Here, we show that a hybrid reaction centre (RC)/yellow fluorescent protein (YFP) complex accelerates photosynthetic growth in the bacterium Rhodobacter sphaeroides. The structure of the RC/YFP-light-harvesting 1 (LH1) complex shows the position of YFP attachment to the RC-H subunit, on the cytoplasmic side of the RC complex. Fluorescence lifetime microscopy of whole cells and ultrafast transient absorption spectroscopy of purified RC/YFP complexes show that the YFP-RC intermolecular distance and spectral overlap between the emission of YFP and the visible-region (QX) absorption bands of the RC allow energy transfer via a Förster mechanism, with an efficiency of 40+/-10%. This proof-of-principle study demonstrates the feasibility of increasing spectral coverage for harvesting light using non-native genetically-encoded light-absorbers, thereby augmenting energy transfer and trapping in photosynthesis.

  11. Synergistic enhancement of nitrogen and sulfur co-doped graphene with carbon nanospheres insertion for electrocatalytic oxygen reduction reaction

    SciTech Connect

    Wu, Min; Xin, Huolin L.; Wang, Jie; Wu, Zexing; Wang, Deli

    2015-03-13

    A nitrogen and sulfur co-doped graphene/carbon black (NSGCB) nanocomposite for the oxygen reduction reaction (ORR) was synthesized through a one-pot annealing of a precursor mixture containing graphene oxide, thiourea, and acidized carbon black (CB). The NSGCB showed excellent performance for the ORR with the onset and half-way potentials at 0.96 V and 0.81 V (vs. RHE), respectively. It is significantly improved over that of the catalysts derived from only graphene (0.90 V and 0.76 V) or carbon nanosphere (0.82 V and 0.74 V). The enhanced catalytic activity on the NSGCB electrode could be attributed to the synergistic effect of N/S co-doping and the enlarged interlayer space resulted from the insertion of carbon nanosphere into the graphene sheets. The four-electron selectivity and the limiting current density of the NSGCB nanocomposite are comparable to that of the commercially Pt/C catalyst. Furthermore, the NSGCB nanocomposite was superior to Pt/C in terms of long-term durability and tolerance to methanol poisoning.

  12. Sequestration of Antimonite by Zerovalent Iron: Using Weak Magnetic Field Effects to Enhance Performance and Characterize Reaction Mechanisms.

    PubMed

    Xu, Chunhua; Zhang, Bingliang; Zhu, Liujia; Lin, Sheng; Sun, Xueping; Jiang, Zheng; Tratnyek, Paul G

    2016-02-02

    Many oxyanion-forming metals (As, Sb, Se, Tc, etc.) can be removed from water by adsorption and/or redox reactions involving iron oxides, including the oxides associated with zerovalent iron (ZVI). The rate of antimonite (Sb(III) hydrolysis species) removal by ZVI was determined in open, well-mixed batch reactors as a function of experimental factors, including aging of the ZVI, addition of Fe(II), Sb dose, mixing rate, pH, initial concentrations of Sb(III), etc. However, the largest effect observed was the roughly 6-8 fold increase in Sb(III) removal rate due to the application of a weak magnetic field (WMF) during the experiments. The WMF effect on Sb removal arises from stimulated corrosion and delayed passivation of the ZVI, as evidenced by time series correlation analysis of "geochemical" properties (DO, Fetot, Eh, and pH) measured synchronously in each experiment. The removal of Sb under the conditions of this study was mainly due to oxidation of Sb(III) to Sb(V) and adsorption and coprecipitation onto the iron oxides formed from accelerated corrosion of ZVI, as evidenced by Sb K-edge XANES, EXAFS, and XPS. The degree of the WMF enhancement for Sb(III) was found to be similar to the WMF effect reported previously for Sb(V), As(III), As(V), and Se(VI).

  13. Synergistic enhancement of nitrogen and sulfur co-doped graphene with carbon nanospheres insertion for electrocatalytic oxygen reduction reaction

    DOE PAGES

    Wu, Min; Xin, Huolin L.; Wang, Jie; ...

    2015-03-13

    A nitrogen and sulfur co-doped graphene/carbon black (NSGCB) nanocomposite for the oxygen reduction reaction (ORR) was synthesized through a one-pot annealing of a precursor mixture containing graphene oxide, thiourea, and acidized carbon black (CB). The NSGCB showed excellent performance for the ORR with the onset and half-way potentials at 0.96 V and 0.81 V (vs. RHE), respectively. It is significantly improved over that of the catalysts derived from only graphene (0.90 V and 0.76 V) or carbon nanosphere (0.82 V and 0.74 V). The enhanced catalytic activity on the NSGCB electrode could be attributed to the synergistic effect of N/Smore » co-doping and the enlarged interlayer space resulted from the insertion of carbon nanosphere into the graphene sheets. The four-electron selectivity and the limiting current density of the NSGCB nanocomposite are comparable to that of the commercially Pt/C catalyst. Furthermore, the NSGCB nanocomposite was superior to Pt/C in terms of long-term durability and tolerance to methanol poisoning.« less

  14. The origin of the large bending enhancement of the reaction of C(2)H(2)(+) with methane: the effects of bending momentum, ruling out the precursor mechanism, and steps toward "Polanyi rules" for polyatomic reactions.

    PubMed

    Liu, Jianbo; Anderson, Scott L

    2009-10-21

    Quasi-classical trajectories for the hydrogen abstraction (HA) reaction C(2)H(2)(+)+ CH(4)--> C(2)H(3)(+)+ CH(3), were analyzed to probe the mechanistic origins of the large, mode-specific reactivity enhancement observed experimentally following excitation of the C(2)H(2)(+)cis-bending mode. The trajectories show the correct trend in reactivity vs. CC stretch and bending excitations, and also reproduce the experimental recoil velocity map. Analysis of the trajectories shows that at collision energy of 0.5 eV hydrogen abstraction is dominated by a direct mechanism, but approximately 15% of the reaction is mediated by a precursor complex. The vibrational enhancement mostly comes from direct collisions. The bending vibration enhances the reactivity in two ways. Collisions in bent geometries (of C(2)H(2)(+)) are more reactive; however, the dominant vibrational effect is a consequence of the momentum associated with the bending vibration. Enhancement by vibrational momentum is reminiscent of the behavior seen by Polanyi and co-workers for late barrier A + BC reactions, and indeed, the atom transfer event in the C(2)H(2)(+)+ CH(4) system does occur late in the collision. We, therefore, explore the possibilities for interpreting polyatomic vibrational dynamics in a "Polanyi Rule" context, using trajectories to guide the construction of a reduced dimensionality surface.

  15. Implementation of 5E Inquiry Incorporated with Analogy Learning Approach to Enhance Conceptual Understanding of Chemical Reaction Rate for Grade 11 Students

    ERIC Educational Resources Information Center

    Supasorn, Saksri; Promarak, Vinich

    2015-01-01

    The main purpose of this study was to enhance student understanding of the scientific concepts of chemical reaction rate. Forty-four grade 11 students were the target group. The treatment tools were seven learning plans of 5E inquiry incorporated with an analogy learning approach during 15 hours of class time. In each learning plan, the students…

  16. Modification of 1,2,4,5-tetrazine with cationic rhenium(I) polypyridine units to afford phosphorogenic bioorthogonal probes with enhanced reaction kinetics.

    PubMed

    Choi, Alex Wing-Tat; Tso, Karson Ka-Shun; Yim, Vicki Man-Wai; Liu, Hua-Wei; Lo, Kenneth Kam-Wing

    2015-02-25

    New phosphorogenic bioorthogonal probes derived from mononuclear and binuclear rhenium(I) polypyridine complexes containing a 1,2,4,5-tetrazine moiety were designed; these complexes displayed substantial dienophile-induced emission enhancement, and accelerated reaction kinetics and could target a protein conjugate in living cells.

  17. Management of Mucositis During Chemotherapy: From Pathophysiology to Pragmatic Therapeutics.

    PubMed

    Van Sebille, Ysabella Z A; Stansborough, Romany; Wardill, Hannah R; Bateman, Emma; Gibson, Rachel J; Keefe, Dorothy M

    2015-11-01

    Chemotherapy-induced mucositis is a common condition caused by the breakdown of the mucosal barrier. Symptoms can include pain, vomiting and diarrhoea, which can often necessitate chemotherapy treatment breaks or dose reductions, thus compromising survival outcomes. Despite the significant impact of mucositis, there are currently limited clinically effective pharmacological therapies for the pathology. New emerging areas of research have been proposed to play key roles in the development of mucositis, providing rationale for potential new therapeutics for the prevention, treatment or management of chemotherapy-induced mucositis. This review aims to address these new areas of research and to comment on the therapeutics arising from them.

  18. Sublingual vaccination with sonicated Salmonella proteins and mucosal adjuvant induces mucosal and systemic immunity and protects mice from lethal enteritis.

    PubMed

    Huang, Ching-Feng; Wu, Tzee-Chung; Wu, Chia-Chao; Lee, Chin-Cheng; Lo, Wen-Tsung; Hwang, Kwei-Shuai; Hsu, Mu-Ling; Peng, Ho-Jen

    2011-07-01

    Salmonella enteritidis is one of the most common pathogens of enteritis. Most experimental vaccines against Salmonella infection have been applied through injections. This is a new trial to explore the effect of sublingual administration of Salmonella vaccines on systemic and mucosal immunity. Adult BALB/c mice were sublingually vaccinated with sonicated Salmonella proteins (SSP) alone, or plus adjuvant CpG DNA (CpG) or cholera toxin (CT). They were boosted 2 weeks later. Saliva specific secretory IgA (SIgA) antibody responses were significantly stimulated in the mice vaccinated with SSP only or together with CpG or CT. Whereas the mice sublingually vaccinated with SSP and CpG had higher spleen cell IFN-γ production and serum specific IgG2a antibody responses, those receiving SSP and CT showed enhanced spleen cell IL-4, IL-5 and IL-6 production, and serum specific IgG1 antibody responses. After oral challenge with live S. enteritidis, the same strain of the source of SSP, immune protection in those sublingually vaccinated with SSP and CpG or CT was found to prevent intestinal necrosis and to render a higher survival rate. In conclusion, sublingual vaccination together with mucosal adjuvant CpG or CT is a simple but effective way against enteric bacterial pathogens.

  19. Facile nucleophilic fluorination reactions using tert-alcohols as a reaction medium: significantly enhanced reactivity of alkali metal fluorides and improved selectivity.

    PubMed

    Kim, Dong Wook; Jeong, Hwan-Jeong; Lim, Seok Tae; Sohn, Myung-Hee; Katzenellenbogen, John A; Chi, Dae Yoon

    2008-02-01

    Although protic solvents are generally not preferred for nucleophilic displacement reactions because of their partial positive charge and hydrogen-bonding capacity that solvate the nucleophile and reduce its reactivity, we recently reported a remarkably beneficial effect of using tertiary alcohols as a reaction media for nucleophilic fluorination with alkali metal fluorides, as well as fluorine-18 radiolabeling with [18F]fluoride ion for the preparation of PET radiopharmaceuticals. In this work, we investigate further the influence of the tert-alcohol reaction medium for nucleophilic fluorination with alkali metal fluorides by studying various interactions among tert-alcohols, the alkali metal fluoride (CsF), and the sulfonyloxy substrate. Factors such as hydrogen bonding between CsF and the tert-alcohol solvent, the formation of a tert-alcohol solvated fluoride, and hydrogen bonding between the sulfonate leaving group and the tert-alcohol appear to contribute to the dramatic increase in the rate of the nucleophilic fluorination reaction in the absence of any kind of catalyst. We found that fluorination of 1-(2-mesyloxyethyl)naphthalene (5) and N-5-bromopentanoyl-3,4-dimethoxyaniline (8) with Bu(4)N(+)F(-) in a tert-alcohol afforded the corresponding fluoro products in much higher yield than obtained by the conventional methods using dipolar aprotic solvents. The protic medium also suppresses formation of byproducts, such as alkenes, ethers, and cyclic adducts.

  20. New generation of oral mucosal vaccines targeting dendritic cells

    PubMed Central

    Owen, Jennifer L.; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-01-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including B. anthracis in experimental models of disease. PMID:23835515

  1. New generation of oral mucosal vaccines targeting dendritic cells.

    PubMed

    Owen, Jennifer L; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-12-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including Bacillus anthracis in experimental models of disease.

  2. Pulsed Laser-Assisted Focused Electron-Beam-Induced Etching of Titanium with XeF 2 : Enhanced Reaction Rate and Precursor Transport

    DOE PAGES

    Noh, J. H.; Fowlkes, J. D.; Timilsina, R.; ...

    2015-01-28

    We introduce a laser-assisted focused electron-beam-induced etching (LA-FEBIE) process which is a versatile, direct write nanofabrication method that allows nanoscale patterning and editing; we do this in order to enhance the etch rate of electron-beam-induced etching. The results demonstrate that the titanium electron stimulated etch rate via the XeF2 precursor can be enhanced up to a factor of 6 times with an intermittent pulsed laser assist. Moreover, the evolution of the etching process is correlated to in situ stage current measurements and scanning electron micrographs as a function of time. Finally, the increased etch rate is attributed to photothermally enhancedmore » Ti–F reaction and TiF4 desorption and in some regimes enhanced XeF2 surface diffusion to the reaction zone.« less

  3. One-Pot Fabrication of Mesoporous Core-Shell Au@PtNi Ternary Metallic Nanoparticles and Their Enhanced Efficiency for Oxygen Reduction Reaction.

    PubMed

    Shi, Qiurong; Zhu, Chengzhou; Fu, Shaofang; Du, Dan; Lin, Yuehe

    2016-02-01

    Currently, Pt-based nanomaterials with tailorable shapes, structures, and morphologies are the most popular electrocatalysts for oxygen reduction reaction, which is a significant cathode reaction in fuel cells for renewable energy applications. We have successfully synthesized mesoporous core-shell Au@PtNi ternary metallic nanoparticles through a one-pot reduction method for cathodic materials used as oxygen reduction reaction catalysts. The as-synthesized nanoparticles exhibited superior catalytic activities and long-term stabilities compared with mesoporous core-shell Au@Pt nanoparticles and commercial Pt/C. The unique mesoporous core-shell structures as well as the alloy shells enable the enhanced electrochemical oxygen reduction reaction performances of the Pt-based materials via the electronic effect and geometric effect, holding great promise in fuel cell application.

  4. Enhanced reaction kinetics and reactive mixing scale dynamics in mixing fronts under shear flow for arbitrary Damköhler numbers

    NASA Astrophysics Data System (ADS)

    Bandopadhyay, Aditya; Le Borgne, Tanguy; Méheust, Yves; Dentz, Marco

    2017-02-01

    Mixing fronts, where fluids of different chemical compositions mix with each other, are known to represent hotspots of chemical reaction in hydrological systems. These fronts are typically subjected to velocity gradients, ranging from the pore scale due to no slip boundary conditions at fluid solid interfaces, to the catchment scale due to permeability variations and complex geometry of the Darcy velocity streamlines. A common trait of these processes is that the mixing interface is strained by shear. Depending on the Péclet number Pe , which represents the ratio of the characteristic diffusion time to the characteristic shear time, and the Damköhler number Da , which represents the ratio of the characteristic diffusion time to the characteristic reaction time, the local reaction rates can be strongly impacted by the dynamics of the mixing interface. So far, this impact has been characterized mostly either in kinetics-limited or in mixing-limited conditions, that is, for either low or high Da. Here the coupling of shear flow and chemical reactivity is investigated for arbitrary Damköhler numbers, for a bimolecular reaction and an initial interface with separated reactants. Approximate analytical expressions for the global production rate and reactive mixing scale are derived based on a reactive lamella approach that allows for a general coupling between stretching enhanced mixing and chemical reactions. While for Pe < Da , reaction kinetics and stretching effects are decoupled, a scenario which we name "weak stretching", for Pe > Da , we uncover a "strong stretching" scenario where new scaling laws emerge from the interplay between reaction kinetics, diffusion, and stretching. The analytical results are validated against numerical simulations. These findings shed light on the effect of flow heterogeneity on the enhancement of chemical reaction and the creation of spatially localized hotspots of reactivity for a broad range of systems ranging from kinetic limited

  5. On the influence of provenance to soil quality enhanced stress reaction of young beech trees to summer drought.

    PubMed

    Buhk, Constanze; Kämmer, Marcel; Beierkuhnlein, Carl; Jentsch, Anke; Kreyling, Jürgen; Jungkunst, Hermann F

    2016-11-01

    Climate projections propose that drought stress will become challenging for establishing trees. The magnitude of stress is dependent on tree species, provenance, and most likely also highly influenced by soil quality. European Beech (Fagus sylvatica) is of major ecological and economical importance in Central European forests. The species has an especially wide physiological and ecological amplitude enabling growth under various soil conditions within its distribution area in Central Europe. We studied the effects of extreme drought on beech saplings (second year) of four climatically distinct provenances growing on different soils (sandy loam and loamy sand) in a full factorial pot experiment. Foliar δ(13)C, δ(15)N, C, and N as well as above- and belowground growth parameters served as measures for stress level and plant growth. Low-quality soil enhanced the effect of drought compared with qualitatively better soil for the above- and belowground growth parameters, but foliar δ(13)C values revealed that plant stress was still remarkable in loamy soil. For beeches of one provenance, negative sandy soil effects were clearly smaller than for the others, whereas for another provenance drought effects in sandy soil were sometimes fatal. Foliar δ(15)N was correlated with plant size during the experiment. Plasticity of beech provenances in their reaction to drought versus control conditions varied clearly. Although a general trend of declining growth under control or drought conditions in sandy soil was found compared to loamy soil, the magnitude of the effect of soil quality was highly provenance specific. Provenances seemed to show adaptations not only to drought but also to soil quality. Accordingly, scientists should integrate information about climatic pre-adaptation and soil quality within the home range of populations for species distribution modeling and foresters should evaluate soil quality and climatic parameters when choosing donor populations for

  6. Platelet-activating factor in Iberian pig spermatozoa: receptor expression and role as enhancer of the calcium-induced acrosome reaction.

    PubMed

    Bragado, M J; Gil, M C; Garcia-Marin, L J

    2011-12-01

    Platelet-activating factor (PAF) is a phospholipid involved in reproductive physiology. PAF receptor is expressed in some mammalian spermatozoa species where it plays a role in these germ-cell-specific processes. The aim of this study is to identify PAF receptor in Iberian pig spermatozoa and to evaluate PAF's effects on motility, viability and acrosome reaction. Semen samples from Iberian boars were used. PAF receptor identification was performed by Western blotting. Spermatozoa motility was analysed by computer-assisted sperm analysis system, whereas spermatozoa viability and acrosome reaction were evaluated by flow cytometry. Different PAF concentrations added to non-capacitating medium during 60 min have no effect on any spermatozoa motility parameter measured. Acrosome reaction was rapid and potently induced by 1 μm calcium ionophore A23187 showing an effect at 60 min and maximum at 240 min. PAF added to a capacitating medium is not able to induce spermatozoa acrosome reaction at any time studied. However, PAF, in the presence of A23187, significantly accelerates and enhances the calcium-induced acrosome reaction in a concentration-dependent manner in Iberian boar spermatozoa. Exogenous PAF does not affect at all spermatozoa viability, whereas slightly exacerbated the A23187-induced loss in viability. This work demonstrates that PAF receptor is expressed in Iberian pig spermatozoa and that its stimulation by PAF regulates the calcium-induced acrosome reaction. This work contributes to further elucidate the physiological regulation of the most relevant spermatozoa functions for successful fertilization: acrosome reaction.

  7. Candidalysin is a fungal peptide toxin critical for mucosal infection

    PubMed Central

    Moyes, David L.; Wilson, Duncan; Richardson, Jonathan P.; Mogavero, Selene; Tang, Shirley X.; Wernecke, Julia; Höfs, Sarah; Gratacap, Remi L.; Robbins, Jon; Runglall, Manohursingh; Murciano, Celia; Blagojevic, Mariana; Thavaraj, Selvam; Förster, Toni M.; Hebecker, Betty; Kasper, Lydia; Vizcay, Gema; Iancu, Simona I.; Kichik, Nessim; Häder, Antje; Kurzai, Oliver; Luo, Ting; Krüger, Thomas; Kniemeyer, Olaf; Cota, Ernesto; Bader, Oliver; Wheeler, Robert T.; Gutsmann, Thomas; Hube, Bernhard; Naglik, Julian R.

    2016-01-01

    Cytolytic proteins and peptide toxins are classical virulence factors of several bacterial pathogens which disrupt epithelial barrier function, damage cells and activate or modulate host immune responses. Until now human pathogenic fungi were not known to possess such toxins. Here we identify the first fungal cytolytic peptide toxin in the opportunistic pathogen Candida albicans. This secreted toxin directly damages epithelial membranes, triggers a danger response signaling pathway and activates epithelial immunity. Toxin-mediated membrane permeabilization is enhanced by a positively charged C-terminus and triggers an inward current concomitant with calcium influx. C. albicans strains lacking this toxin do not activate or damage epithelial cells and are avirulent in animal models of mucosal infection. We propose the name ‘Candidalysin’ for this cytolytic peptide toxin; a newly identified, critical molecular determinant of epithelial damage and host recognition of the clinically important fungus, C. albicans. PMID:27027296

  8. Probiotics as Antifungals in Mucosal Candidiasis.

    PubMed

    Matsubara, Victor H; Bandara, H M H N; Mayer, Marcia P A; Samaranayake, Lakshman P

    2016-05-01

    Candidais an opportunistic pathogen that causes mucosal and deep systemic candidiasis. The emergence of drug resistance and the side effects of currently available antifungals have restricted their use as long-term prophylactic agents for candidal infections. Given this scenario, probiotics have been suggested as a useful alternative for the management of candidiasis. We analyzed the available data on the efficacy of probiotics in candidal colonization of host surfaces. A number of well-controlled studies indicate that probiotics, particularly lactobacilli, suppressCandidagrowth and biofilm development in vitro.A few clinical trials have also shown the beneficial effects of probiotics in reducing oral, vaginal, and enteric colonization byCandida; alleviation of clinical signs and symptoms; and, in some cases, reducing the incidence of invasive fungal infection in critically ill patients. Probiotics may serve in the future as a worthy ally in the battle against chronic mucosal candidal infections.

  9. A more robust model of the biodiesel reaction, allowing identification of process conditions for significantly enhanced rate and water tolerance.

    PubMed

    Eze, Valentine C; Phan, Anh N; Harvey, Adam P

    2014-03-01

    A more robust kinetic model of base-catalysed transesterification than the conventional reaction scheme has been developed. All the relevant reactions in the base-catalysed transesterification of rapeseed oil (RSO) to fatty acid methyl ester (FAME) were investigated experimentally, and validated numerically in a model implemented using MATLAB. It was found that including the saponification of RSO and FAME side reactions and hydroxide-methoxide equilibrium data explained various effects that are not captured by simpler conventional models. Both the experiment and modelling showed that the "biodiesel reaction" can reach the desired level of conversion (>95%) in less than 2min. Given the right set of conditions, the transesterification can reach over 95% conversion, before the saponification losses become significant. This means that the reaction must be performed in a reactor exhibiting good mixing and good control of residence time, and the reaction mixture must be quenched rapidly as it leaves the reactor.

  10. CpG oligodeoxynucleotides as mucosal adjuvants

    PubMed Central

    Iho, Sumiko; Maeyama, Jun-ichi; Suzuki, Fumiko

    2015-01-01

    Bacterial DNA comprising palindromic sequences and containing unmethylated CpG is recognized by toll-like receptor 9 of plasmacytoid dendritic cells (pDCs) and induces the production of interferon-α and chemokines, leading to the activation of a Th1 immune response. Therefore, synthetic equivalents of bacterial DNA (CpG oligodeoxynucleotides) have been developed for clinical applications. They are usually phosphorothioated for in vivo use; this approach also leads to adverse effects as reported in mouse models.Mucosal vaccines that induce both mucosal and systemic immunity received substantial attention in recent years. For their development, phosphodiester-linked oligodeoxynucleotides, including the sequence of a palindromic CpG DNA may be advantageous as adjuvants because their target pDCs are present right there, in the mucosa of the vaccination site. In addition, the probability of adverse effects is believed to be low. Here, we review the discovery of such CpG oligodeoxynucleotides and their possible use as mucosal adjuvants. PMID:25751765

  11. Hitting the mucosal road in tolerance induction.

    PubMed

    Wiedermann, Ursula

    2009-01-01

    Within the last decades a dramatic increase in allergic diseases has been recognized in the Westernized societies, leading to the fact that meanwhile 25-30% of the population is afflicted by allergic disorders. Besides a hereditary disposition, other factors, including a reduced microbial contact early in life or changes in nutrition, might also have influenced this epidemiological development. So far the only causative treatment against type-I allergies is specific immunotherapy. In young and monosensitized patients this treatment is highly efficacious, while there are clear limitations in older or multisensitized patients. Allergy research therefore aims at establishing new and more efficacious treatment strategies in prophylactic as well as therapeutic settings. Our research programs focus on the development of novel allergy vaccines based on the induction of mucosal tolerance. In different mouse models of respiratory allergy mucosal treatment with genetically engineered allergen constructs proved to prevent the development of allergic mono- and multisensitivities. The additional use of mucosal adjuvants seems particularly important to improve therapeutic treatment approaches. Recent studies on the inverse relation of certain parasite infections and the development of allergy prompted us to search for selected parasitic molecules with immunosuppressive properties as potential adjuvant systems for novel allergy vaccines. An overview of our recent studies will be given.

  12. Dermoscopic appearance of an amelanotic mucosal melanoma

    PubMed Central

    Blum, Andreas; Beck-Zoul, Ulrike; Held, Laura; Haase, Sylvie

    2016-01-01

    Background Hypomelanotic or amelanotic melanomas are challenging to identify, especially at mucosal sites. The dermoscopic clues to the diagnosis of mucosal melanomas have been reported to be structureless zones with the presence of blue, gray, or white colors. Case A female in her seventies noted a new lesion on the inside of her right labia that first appeared two months prior. Her past medical history was significant for rheumatoid arthritis requiring ongoing treatment with methotrexate for 20 years and adalimumab for 10 years. After no response to two weeks of local treatment for suspected herpes simplex infection, her gynecologist performed a skin biopsy. Based on the histopathological diagnosis of an amelanotic melanoma (Breslow thickness of 1.3 mm) the patient was referred to dermatology for further assessment. Polarized dermoscopy revealed a distinct asymmetric, sharply demarcated homogenous white papule (4 × 5 mm) as well as polymorphous vessels. Conclusion Dermoscopy may aid in the diagnosis of amelanotic mucosal melanomas. Our case revealed a structureless white area and polymorphous vessels. Additional clues to the diagnosis were the advanced age of the patient and the clinical presentation of a new lesion. PMID:27867742

  13. Oral mucosal manifestations of autoimmune skin diseases.

    PubMed

    Mustafa, Mayson B; Porter, Stephen R; Smoller, Bruce R; Sitaru, Cassian

    2015-10-01

    A group of autoimmune diseases is characterised by autoantibodies against epithelial adhesion structures and/or tissue-tropic lymphocytes driving inflammatory processes resulting in specific pathology at the mucosal surfaces and the skin. The most frequent site of mucosal involvement in autoimmune diseases is the oral cavity. Broadly, these diseases include conditions affecting the cell-cell adhesion causing intra-epithelial blistering and those where autoantibodies or infiltration lymphocytes cause a loss of cell-matrix adhesion or interface inflammation. Clinically, patients present with blistering, erosions and ulcers that may affect the skin as well as further mucosal surfaces of the eyes, nose and genitalia. While the autoimmune disease may be suspected based on clinical manifestations, demonstration of tissue-bound and circulating autoantibodies, or lymphocytic infiltrates, by various methods including histological examination, direct and indirect immunofluorescence microscopy, immunoblotting and quantitative immunoassay is a prerequisite for definitive diagnosis. Given the frequency of oral involvement and the fact that oral mucosa is the initially affected site in many cases, the informed practitioner should be well acquainted with diagnostic and therapeutic aspects of autoimmune dermatosis with oral involvement. This paper reviews the pathogenesis and clinical presentation of these conditions in the oral cavity with a specific emphasis on their differential diagnosis and current management approaches.

  14. Age, gender, dentures and oral mucosal disorders.

    PubMed

    MacEntee, M I; Glick, N; Stolar, E

    1998-03-01

    The numbers of participants over 75 years of age in previous studies of oral health have not been sufficient to permit a full investigation of the influence of age on the mouth. In this study a disproportionate stratified random sample of 255 independent elders was selected from a list of urban voters to provide similar numbers of men and women in three age groups. The subjects were interviewed and examined, and nearly half of them had mucosal disorders. There was a significant (P < 0.05) association between mucosal lesions and the use of dentures and tobacco, whereas stomatitis, denture-related hyperplasia and angular cheilitis in particular were associated significantly with men and with the use of defective dentures. Logistic regression revealed that neither age alone nor the quality of dentures predispose to mucosal lesions, but that the odds of finding stomatitis, denture-related hyperplasia and angular cheilitis in particular increased about three-fold in denture-users, and almost doubled in men.

  15. Mucosal perforators from the facial artery.

    PubMed

    Coronel-Banda, Mauricio E; Serra-Renom, Jose M; Lorente, Marian; Larrea-Terán, Wendy P

    2014-07-01

    The cutaneous perforators of the facial artery have been well described, but to our knowledge the oral mucosal perforators have not. We studied 10 facial arteries from 10 hemifaces in 5 cadavers. The arteries were injected with latex, and we studied all perforators that extended from the facial artery and headed directly to the oral mucosa. The diameter and length of the facial artery and its mucosal perforators were measured and compared. We found 52 oral mucosal perforators in the 10 facial arteries injected with latex. Their mean (SD) diameter was 0.5 (0.2) mm and the mean (SD) number/facial artery was 5.2 (1.1). Their mean (SD) length was 16.4 (5.3) mm. Most of those to the cheek were localised between the branching-off points of the inferior and superior labial arteries. The facial artery has perforators to the oral mucosa of the cheek, most of them between the points at which the labial arteries emerge.

  16. Effect of Pakistani medicinal plants on IgE/antigen- and ionophore-induced mucosal mast cells degranulation.

    PubMed

    Zaidi, Syed Faisal; Kim, Ji-Hyun; Tomoe, Yashiro; Usmanghani, Khan; Kadowaki, Makoto

    2014-07-01

    Cumulative evidence has now demonstrated the stimulation of mucosal mast cells by both allergic and non-allergic triggers and their inhibition as a potential therapeutic target in many diseases like food allergy and ulcerative colitis. Hence, we screened medicinal plants from Pakistan against antigen- and ionophore-induced degranulation of mucosal mast cells. Aqueous ethanol extracts were screened. IgE/antigen- and A23187-induced degranulation of mucosal-type murine bone marrow derived mast cells (mBMMCs) were screening assays and β-hexosaminidase released from degranulated mBMMCs was measured. Real time-polymerase chain reaction was employed to examine the expression of TNF-α and IL-4 mRNA. Acetoxychavicol acetate, was examined by degranulation assays and real time-PCR. Among the ten plants screened against IgE/antigen stimulated degranulation, five plants; Alpinia galangal, Mentha arvensis, Myrtus communis, Polygonum bistorta and Syzygium aromaticum demonstrated significant (p<0.01) suppression of the degranulation at 100 μg/ml. Of them, Alpinia galangal showed significant (p<0.01) inhibition at 32 mg/ml. In A23187-induced degranulation, all plants showed significant (p<0.01) inhibition at 100 μg/ml except Tamarix dioica. Again Alpinia galangal exhibited significant (p<0.01) suppression at 32 μg/ml. In a concentration dependent assay, Alpinia galangal revealed significant suppression at 10 μg/ml against A23187-stimulated degranulation. Acetoxychavicol acetate demonstrated significant (p<0.01) inhibition at 3.2 μM in IgE/antigen-treated cells and at 10 μM in A23187-treated cells. Furthermore, both Alpinia galangal and acetoxychavicol acetate suppressed the IgE/antigen- and A23187-enhanced mRNA expression of inflammatory cytokines, TNF-a and IL-4, in mBMMCs. Our findings revealed the suppressive effect of Alpinia galangal and acetoxychavicol acetate on degranulation of mBMMCs by allergic and non-allergic stimuli, which can be utilized for future drug

  17. Role of sulfhydryls in mucosal injury caused by ethanol: relation to microvascular permeability, gastric motility and cytoprotection

    SciTech Connect

    Takeuchi, K.; Okada, M.; Niida, H.; Okabe, S.

    1989-02-01

    The relationship between gastric mucosal glutathione (GSH) levels, vascular permeability, gastric motility and mucosal injury caused by ethanol was investigated in rats. Oral administration of 50% ethanol (1 ml) produced elongated reddish bands of lesions in the mucosa with a significant reduction of GSH levels and increase of microvascular permeability. These lesions were significantly inhibited by pretreatment with s.c. administered diethylmaleate (DEM: 1 ml/kg), cysteamine (100 mg/kg) and 16, 16-dimethyl prostaglandin E2 (dmPGE2, 10 micrograms/kg) but worsened markedly by N-ethylmaleimide (NEM: 10 mg/kg). Irrespective of whether the animals were treated with 50% ethanol or not, the mucosal GSH levels were significantly decreased or increased, respectively, by DEM or cysteamine, and were not affected by both NEM and dmPGE2. NEM significantly enhanced the vascular permeability in the absence or presence of ethanol (greater than 10%), whereas other agents significantly inhibited only the increased vascular permeability caused by ethanol. On the other hand, gastric motility was potently and persistently inhibited by either DEM, cysteamine or dmPGE2 at the doses which prevented ethanol-induced mucosal injury, whereas NEM had no effect on the motility. These results suggest that 1) the mucosal GSH levels do not relate directly to either development or prevention of ethanol-induced gastric injury, 2) potentiation by NEM of the mucosal injury may be accounted for by its enhancement of the vascular permeability and 3) inhibition of gastric motility may be associated with prevention of mucosal lesions.

  18. Gut permeability and mucosal inflammation: bad, good or context dependent.

    PubMed

    Ahmad, R; Sorrell, M F; Batra, S K; Dhawan, P; Singh, A B

    2017-03-01

    Inflammatory bowel disease (IBD) is a multifactorial disease. A breach in the mucosal barrier, otherwise known as "leaky gut," is alleged to promote mucosal inflammation by intensifying immune activation. However, interaction between the luminal antigen and mucosal immune system is necessary to maintain mucosal homeostasis. Furthermore, manipulations leading to deregulated gut permeability have resulted in susceptibility in mice to colitis as well as to creating adaptive immunity. These findings implicate a complex but dynamic association between mucosal permeability and immune homeostasis; however, they also emphasize that compromised gut permeability alone may not be sufficient to induce colitis. Emerging evidence further supports the role(s) of proteins associated with the mucosal barrier in epithelial injury and repair: manipulations of associated proteins also modified epithelial differentiation, proliferation, and apoptosis. Taken together, the role of gut permeability and proteins associated in regulating mucosal inflammatory diseases appears to be more complex than previously thought. Herein, we review outcomes from recent mouse models where gut permeability was altered by direct and indirect effects of manipulating mucosal barrier-associated proteins, to highlight the significance of mucosal permeability and the non-barrier-related roles of these proteins in regulating chronic mucosal inflammatory conditions.

  19. Mucosal and systemic anti-HIV immunity controlled by A20 in mouse dendritic cells.

    PubMed

    Hong, Bangxing; Song, Xiao-Tong; Rollins, Lisa; Berry, Lindsey; Huang, Xue F; Chen, Si-Yi

    2011-02-01

    Both mucosal and systemic immune responses are required for preventing or containing HIV transmission and chronic infection. However, currently described vaccination approaches are largely ineffective in inducing both mucosal and systemic responses. In this study, we found that the ubiquitin-editing enzyme A20--an inducible feedback inhibitor of the TNFR, RIG-I, and TLR signaling pathways that broadly controls the maturation, cytokine production, and immunostimulatory potency of DCs--restricted systemically immunized DCs to induce both robust mucosal and systemic HIV-specific cellular and humoral responses. Mechanistic studies revealed that A20 regulated DC production of retinoic acid and proinflammatory cytokines, inhibiting the expression of gut-homing receptors on T and B cells. Furthermore, A20-silenced, hyperactivated DCs exhibited an enhanced homing capacity to draining and gut-associated lymphoid tissues (GALTs) after systemic administration. Thus, this study provides insights into the role of A20 in innate immunity. This work may allow the development of an efficient HIV vaccination strategy that is capable of inducing both robust systemic and mucosal anti-HIV cellular and humoral responses.

  20. Mucosal and systemic anti-HIV immunity controlled by A20 in mouse dendritic cells

    PubMed Central

    Hong, Bangxing; Song, Xiao-Tong; Rollins, Lisa; Berry, Lindsey; Huang, Xue F.; Chen, Si-Yi

    2011-01-01

    Both mucosal and systemic immune responses are required for preventing or containing HIV transmission and chronic infection. However, currently described vaccination approaches are largely ineffective in inducing both mucosal and systemic responses. In this study, we found that the ubiquitin-editing enzyme A20 — an inducible feedback inhibitor of the TNFR, RIG-I, and TLR signaling pathways that broadly controls the maturation, cytokine production, and immunostimulatory potency of DCs — restricted systemically immunized DCs to induce both robust mucosal and systemic HIV-specific cellular and humoral responses. Mechanistic studies revealed that A20 regulated DC production of retinoic acid and proinflammatory cytokines, inhibiting the expression of gut-homing receptors on T and B cells. Furthermore, A20-silenced, hyperactivated DCs exhibited an enhanced homing capacity to draining and gut-associated lymphoid tissues (GALTs) after systemic administration. Thus, this study provides insights into the role of A20 in innate immunity. This work may allow the development of an efficient HIV vaccination strategy that is capable of inducing both robust systemic and mucosal anti-HIV cellular and humoral responses. PMID:21206085

  1. The matricellular protein CCN1 promotes mucosal healing in murine colitis through IL-6.

    PubMed

    Choi, J S; Kim, K-H; Lau, L F

    2015-11-01

    The matricellular protein CCN1 (CYR61) is known to function in wound healing and is upregulated in colons of patients with Crohn's disease and ulcerative colitis, yet its specific role in colitis is unknown. Here we have used Ccn1(dm/dm) knockin mice expressing a CCN1 mutant unable to bind integrins α6β1 and αMβ2 as a model to probe CCN1 function in dextran sodium sulfate (DSS)-induced colitis. Ccn1(dm/dm) mice exhibited high mortality, impaired mucosal healing, and diminished interleukin-6 (IL-6) expression during the repair phase of DSS-induced colitis compared with wild-type mice, despite having comparable severity of initial inflammation and tissue injury. CCN1-induced IL-6 expression in macrophages through integrin αMβ2 and in fibroblasts through α6β1, and IL-6 promoted intestinal epithelial cell (IEC) proliferation. Administration of purified CCN1 protein fully rescued Ccn1(dm/dm) mice from DSS-induced mortality, restored IEC proliferation and enhanced mucosal healing, whereas delivery of IL-6 partially rectified these defects. CCN1 therapy accelerated mucosal healing and recovery from DSS-induced colitis even in wild-type mice. These findings reveal a critical role for CCN1 in restoring mucosal homeostasis after intestinal injury in part through integrin-mediated induction of IL-6 expression, and suggest a therapeutic potential for activating the CCN1/IL-6 axis for treating inflammatory bowel disease.

  2. Probiotic Bacillus pumilus SE5 shapes the intestinal microbiota and mucosal immunity in grouper Epinephelus coioides.

    PubMed

    Yang, Hong-Ling; Xia, Han-Qin; Ye, Yi-Dan; Zou, Wen-Chao; Sun, Yun-Zhang

    2014-09-30

    The health benefits of probiotics are thought to occur, at least in part, through an improved intestinal microbial balance in fish, although the molecular mechanisms whereby probiotics modulate the intestinal microbiota by means of activation of mucosal immunity are rarely explored. In this study, the effects of viable and heat-inactivated probiotic Bacillus pumilus SE5 on the intestinal dominant microbial community and mucosal immune gene expression were evaluated. The fish were fed for 60 d with 3 different diets: control (without probiotic), and diets T1 and T2 supplemented with 1.0 × 10⁸ cells g⁻¹ viable and heat-inactivated B. pumilus SE5, respectively. Upregulated expression of TLR1, TLR2 and IL-8, but not MyD88 was observed in fish fed the viable probiotic, while elevated expression of TLR2, IL-8 and TGF-β1, but not MyD88 was observed in fish fed the heat-inactivated B. pumilus SE5. The induced activation of intestinal mucosal immunity, especially the enhanced expression of antibacterial epinecidin-1, was consistent with the microbial data showing that several potentially pathogenic bacterial species such as Psychroserpens burtonensis and Pantoea agglomerans were suppressed by both the viable and heat-inactivated probiotic B. pumilus SE5. These results lay the foundation for future studies on the molecular interactions between probiotics, intestinal microbiota and mucosal immunity in fish.

  3. Novel ISCOMs from Quillaja brasiliensis saponins induce mucosal and systemic antibody production, T-cell responses and improved antigen uptake.

    PubMed

    Cibulski, Samuel Paulo; Mourglia-Ettlin, Gustavo; Teixeira, Thais Fumaco; Quirici, Lenora; Roehe, Paulo Michel; Ferreira, Fernando; Silveira, Fernando

    2016-02-24

    In the last decades, significant efforts have been dedicated to the search for novel vaccine adjuvants. In this regard, saponins and its formulations as "immunostimulating complexes" (ISCOMs) have shown to be capable of stimulating potent humoral and cellular immune responses, enhanced cytokine production and activation of cytotoxic T cells. The immunological activity of ISCOMs formulated with a saponin fraction extracted from Quillaja brasiliensis (QB-90 fraction) as an alternative to classical ISCOMs based on Quil A(®) (IQA) is presented here. The ISCOMs prepared with QB-90, named IQB-90, typically consist of 40-50 nm, spherical, cage-like particles, built up by QB-90, cholesterol, phospholipids and antigen (ovalbumin, OVA). These nanoparticles were efficiently uptaken in vitro by murine bone marrow-derived dendritic cells. Subcutaneously inoculated IQB-90 induced strong serum antibody responses encompassing specific IgG1 and IgG2a, robust DTH reactions, significant T cell proliferation and increases in Th1 (IFN-γ and IL-2) cytokine responses. Intranasally delivered IQB-90 elicited serum IgG and IgG1, and mucosal IgA responses at distal systemic sites (nasal passages, large intestine and vaginal lumen). These results indicate that IQB-90 is a promising alternative to classic ISCOMs as vaccine adjuvants, capable of enhancing humoral and cellular immunity to levels comparable to those induced by ISCOMs manufactured with Quillaja saponaria saponins.

  4. Starter Feeding Supplementation Alters Colonic Mucosal Bacterial Communities and Modulates Mucosal Immune Homeostasis in Newborn Lambs

    PubMed Central

    Liu, Junhua; Bian, Gaorui; Sun, Daming; Zhu, Weiyun; Mao, Shengyong

    2017-01-01

    This study aims to investigate the effect of starter feeding supplementation on colonic mucosal bacterial communities and on mucosal immune homeostasis in pre-weaned lambs. We selected eight pairs of 10-day-old lamb twins. One twin was fed breast milk (M, n = 8), while the other was fed breast milk plus starter (M+S, n = 8). The lambs were sacrificed at 56 days age. Colonic content was collected to determine the pH and the concentrations of volatile fatty acids (VFA) and lactate. The colonic mucosa was harvested to characterize the bacterial communities using Illumina MiSeq sequencing and to determine mRNA expression levels of cytokines and toll-like receptors (TLR) using quantitative real-time PCR. The results show that starter feeding decreased luminal pH and increased the concentrations of acetate, propionate, butyrate, total VFA, and lactate in the colon. The principal coordinate analysis (PCA) and analysis of molecular variance show that starter feeding supplementation significantly affected the colonic mucosal bacterial communities with a higher relative abundance of the dominant taxa unclassified S24-7, Oscillibacter, Prevotella, Parabacteroides, Bifidobacterium, Ruminobacter, and Succinivibrio, and a lower proportion of unclassified Ruminococcaceae, RC9_gut_group, Blautia, Phocaeicola, Phascolarctobacterium, unclassified BS11_gut_group, unclassified family_XIII, and Campylobacter in lambs. Meanwhile, starter feeding decreased mRNA expression of TLR4 and cytokines TNF-α and IFN-γ in colonic tissue. Furthermore, the changes in the colonic mucosal mRNA expression of TLR and cytokines were associated with changes in mucosal bacterial composition. These findings may provide new insights into colonic mucosal bacteria and immune homeostasis in developing lambs. PMID:28382025

  5. A Novel Peptide to Treat Oral Mucositis Blocks Endothelial and Epithelial Cell Apoptosis

    SciTech Connect

    Wu Xiaoyan; Chen Peili; Sonis, Stephen T.; Lingen, Mark W.; Berger, Ann; Toback, F. Gary

    2012-07-01

    Purpose: No effective agents currently exist to treat oral mucositis (OM) in patients receiving chemoradiation for the treatment of head-and-neck cancer. We identified a novel 21-amino acid peptide derived from antrum mucosal protein-18 that is cytoprotective, mitogenic, and motogenic in tissue culture and animal models of gastrointestinal epithelial cell injury. We examined whether administration of antrum mucosal protein peptide (AMP-p) could protect against and/or speed recovery from OM. Methods and Materials: OM was induced in established hamster models by a single dose of radiation, fractionated radiation, or fractionated radiation together with cisplatin to simulate conventional treatments of head-and-neck cancer. Results: Daily subcutaneous administration of AMP-p reduced the occurrence of ulceration and accelerated mucosal recovery in all three models. A delay in the onset of erythema after irradiation was observed, suggesting that a protective effect exists even before injury to mucosal epithelial cells occurs. To test this hypothesis, the effects of AMP-p on tumor necrosis factor-{alpha}-induced apoptosis were studied in an endothelial cell line (human dermal microvascular endothelial cells) as well as an epithelial cell line (human adult low-calcium, high-temperature keratinocytes; HaCaT) used to model the oral mucosa. AMP-p treatment, either before or after cell monolayers were exposed to tumor necrosis factor-{alpha}, protected against development of apoptosis in both cell types when assessed by annexin V and propidium iodide staining followed by flow cytometry or ligase-mediated polymerase chain reaction. Conclusions: These observations suggest that the ability of AMP-p to attenuate radiation-induced OM could be attributable, at least in part, to its antiapoptotic activity.

  6. Buccal mucosal graft in reconstructive urology: uses beyond urethral stricture.

    PubMed

    Pandey, Abhishek; Dican, Razvan; Beier, Jörn; Keller, Hansjörg

    2014-07-01

    The use of buccal mucosal grafts for the reconstruction of urethral strictures is an established procedure. Because of its robustness, the buccal mucosal graft could also potentially provide an alternative for other indications in reconstructive urology. We report here six consecutive patients who received a buccal mucosal graft for ureteral strictures, glans reconstruction and stoma stenosis. The follow up for all patients ranged from 26 to 50 months. The buccal mucosal graft showed excellent functional results for the ureteral strictures and stenosis from ureterocutaneostomy. For glans reconstructions, the buccal mucosal grafts delivered excellent cosmetic and functional results without causing meatal stenosis. We conclude the buccal mucosal graft can be used in reconstructive surgery beyond the reconstruction of urethral strictures.

  7. Natural compounds containing a catechol group enhance the formation of Nε-(carboxymethyl)lysine of the Maillard reaction.

    PubMed

    Fujiwara, Yukio; Kiyota, Naoko; Tsurushima, Keiichiro; Yoshitomi, Makiko; Mera, Katsumi; Sakashita, Naomi; Takeya, Motohiro; Ikeda, Tsuyoshi; Araki, Tomohiro; Nohara, Toshihiro; Nagai, Ryoji

    2011-04-01

    Inhibition of advanced glycation end-product (AGE) formation is a potential strategy for the prevention of clinical diabetes complications. Screening for new AGE inhibitors revealed several natural compounds that inhibited the formation of N(ε)-(carboxymethyl)lysine (CML), a major antigenic AGE structure, whereas natural compounds containing a catechol group, such as gallic acid and epicatechin, significantly enhanced CML formation. A similar enhancing effect was also observed by culturing THP-1 macrophages in the presence of catechol compounds. Although 4-methylcatechol significantly enhanced CML formation from glycated HSA (gHSA), a model for Amadori proteins, analogues of catechol such as 5-methylresorcinol and methylhydroquinone showed no enhancing effect. Even though 1mM 4-methylcatechol, epicatechin, and gallic acid significantly enhanced CML formation from gHSA, it was significantly inhibited by decreasing their concentration. The enhancing effect of 1mM catechol compounds was inhibited in the presence of the glutathione peroxidase system, thus demonstrating that hydrogen peroxide generated from catechol compounds plays an important role in the enhancement of CML formation. Furthermore, administration of 500mg/kg/day epicatechin to STZ-induced diabetic mice for 45days enhanced CML accumulation at the surface area of gastric epithelial cells in the stomach. This study provides the first evidence that high amounts of catechol-containing structures enhance oxidative stress, thus leading to enhanced CML formation, and this phenomenon may explain the paradoxical effect that some flavonoids have on redox status.

  8. Evidence for a common mucosal immune system in the pig.

    PubMed

    Wilson, Heather L; Obradovic, Milan R

    2015-07-01

    The majority of lymphocytes activated at mucosal sites receive instructions to home back to the local mucosa, but a portion also seed distal mucosa sites. By seeding distal sites with antigen-specific effector or memory lymphocytes, the foundation is laid for the animal's mucosal immune system to respond with a secondary response should to this antigen be encountered at this site in the future. The common mucosal immune system has been studied quite extensively in rodent models but less so in large animal models such as the pig. Reasons for this paucity of reported induction of the common mucosal immune system in this species may be that distal mucosal sites were examined but no induction was observed and therefore it was not reported. However, we suspect that the majority of investigators simply did not sample distal mucosal sites and therefore there is little evidence of immune response induction in the literature. It is our hope that more pig immunologists and infectious disease experts who perform mucosal immunizations or inoculations on pigs will sample distal mucosal sites and report their findings, whether results are positive or negative. In this review, we highlight papers that show that immunization/inoculation using one route triggers mucosal immune system induction locally, systemically, and within at least one distal mucosal site. Only by understanding whether immunizations at one site triggers immunity throughout the common mucosal immune system can we rationally develop vaccines for the pig, and through these works we can gather evidence about the mucosal immune system that may be extrapolated to other livestock species or humans.

  9. Stimulating effect of Japanese herbal (kampo) medicine, hochuekkito on upper respiratory mucosal immune system.

    PubMed

    Kiyohara, H; Nagai, T; Munakata, K; Nonaka, K; Hanawa, T; Kim, S J; Yamada, H

    2006-12-01

    Japanese herbal (Kampo) medicine, Hochuekkito (Bu-Zhong-Yi-Qi-Tang in Chinese, TJ-41) and Juzentaihoto (Shi-Quan-Da-Bu-Tang in Chinese, TJ-48) are well-known Kampo formulas used as tonic. Although these medicines have separately been applied to the patients clinically depending on their symptoms, the differences of the pharmacological activities for these medicines have not been fully understood. TJ-48 and TJ-41 were compared for their effects on antibody response in upper respiratory mucosal immune system in vivo. Oral administration of TJ-41 (100 mg kg(-1) per day) to early aged BALB/c mice, which were nasally sensitized with influenza hemagglutinin vaccine, significantly enhanced influenza virus-specific IgA and IgG antibody titers in nasal cavity and sera, respectively. However, oral administration of TJ-48 (100 mg kg(-1) per day) failed to show the enhancing activity. TJ-41 increased not only influenza virus-specific IgA antibody titer but also total IgA antibody titer in nasal cavity. The stimulating activity of TJ-41 disappeared after treatment with methotrexate. The present study strongly suggests that TJ-41 can stimulate the mucosal immune system of upper respiratory tract, and results in enhancement of antigen-specific antibody response in upper respiratory mucosal and systemic immune systems.

  10. Stimulating Effect of Japanese Herbal (Kampo) Medicine, Hochuekkito on Upper Respiratory Mucosal Immune System

    PubMed Central

    Kiyohara, H.; Nagai, T.; Munakata, K.; Nonaka, K.; Hanawa, T.; Kim, S. J.; Yamada, H.

    2006-01-01

    Japanese herbal (Kampo) medicine, Hochuekkito (Bu-Zhong-Yi-Qi-Tang in Chinese, TJ-41) and Juzentaihoto (Shi-Quan-Da-Bu-Tang in Chinese, TJ-48) are well-known Kampo formulas used as tonic. Although these medicines have separately been applied to the patients clinically depending on their symptoms, the differences of the pharmacological activities for these medicines have not been fully understood. TJ-48 and TJ-41 were compared for their effects on antibody response in upper respiratory mucosal immune system in vivo. Oral administration of TJ-41 (100 mg kg−1 per day) to early aged BALB/c mice, which were nasally sensitized with influenza hemagglutinin vaccine, significantly enhanced influenza virus-specific IgA and IgG antibody titers in nasal cavity and sera, respectively. However, oral administration of TJ-48 (100 mg kg−1 per day) failed to show the enhancing activity. TJ-41 increased not only influenza virus-specific IgA antibody titer but also total IgA antibody titer in nasal cavity. The stimulating activity of TJ-41 disappeared after treatment with methotrexate. The present study strongly suggests that TJ-41 can stimulate the mucosal immune system of upper respiratory tract, and results in enhancement of antigen-specific antibody response in upper respiratory mucosal and systemic immune systems. PMID:17173109

  11. Defensins as anti-inflammatory compounds and mucosal adjuvants

    PubMed Central

    Kohlgraf, Karl G; Pingel, Lindsey C; Dietrich, Deborah E; Brogden, Kim A

    2010-01-01

    Human neutrophil peptide α-defensins and human β-defensins are small, well-characterized peptides with broad antimicrobial activities. In mixtures with microbial antigens, defensins attenuate proinflammatory cytokine responses by dendritic cells in culture, attenuate proinflammatory cytokine responses in the nasal fluids of exposed mice and enhance antibody responses in the serum of vaccinated mice. Although the exact mechanisms are unknown, defensins first start by binding to microbial antigens and adhesins, often attenuating toxic or inflammatory-inducing capacities. Binding is not generic; it appears to be both defensin-specific and antigen-specific with high affinities. Binding of defensins to antigens may, in turn, alter the interaction of antigens with epithelial cells and antigen-presenting cells attenuating the production of proinflammatory cytokines. The binding of defensins to antigens may also facilitate the delivery of bound antigen to antigen-presenting cells in some cases via specific receptors. These interactions enhance the immunogenicity of the bound antigen in an adjuvant-like fashion. Future research will determine the extent to which defensins can suppress early events in inflammation and enhance systemic antibody responses, a very recent and exciting concept that could be exploited to develop therapeutics to prevent or treat a variety of oral mucosal infections, particularly where inflammation plays a role in the pathogenesis of disease and its long-term sequelae. PMID:20020832

  12. Mucosal and systemic adjuvant activity of alphavirus replicon particles

    NASA Astrophysics Data System (ADS)

    Thompson, Joseph M.; Whitmore, Alan C.; Konopka, Jennifer L.; Collier, Martha L.; Richmond, Erin M. B.; Davis, Nancy L.; Staats, Herman F.; Johnston, Robert E.

    2006-03-01

    Vaccination represents the most effective control measure in the fight against infectious diseases. Local mucosal immune responses are critical for protection from, and resolution of, infection by numerous mucosal pathogens. Antigen processing across mucosal surfaces is the natural route by which mucosal immunity is generated, as peripheral antigen delivery typically fails to induce mucosal immune responses. However, we demonstrate in this article that mucosal immune responses are evident at multiple mucosal surfaces after parenteral delivery of Venezuelan equine encephalitis virus replicon particles (VRP). Moreover, coinoculation of null VRP (not expressing any transgene) with inactivated influenza virions, or ovalbumin, resulted in a significant increase in antigen-specific systemic IgG and fecal IgA antibodies, compared with antigen alone. Pretreatment of VRP with UV light largely abrogated this adjuvant effect. These results demonstrate that alphavirus replicon particles possess intrinsic systemic and mucosal adjuvant activity and suggest that VRP RNA replication is the trigger for this activity. We feel that these observations and the continued experimentation they stimulate will ultimately define the specific components of an alternative pathway for the induction of mucosal immunity, and if the activity is evident in humans, will enable new possibilities for safe and inexpensive subunit and inactivated vaccines. vaccine vector | Venezuelan equine encephalitis virus | viral immunology | RNA virus

  13. Role of B Cells in Mucosal Vaccine-Induced Protective CD8+ T Cell Immunity against Pulmonary Tuberculosis.

    PubMed

    Khera, Amandeep K; Afkhami, Sam; Lai, Rocky; Jeyanathan, Mangalakumari; Zganiacz, Anna; Mandur, Talveer; Hammill, Joni; Damjanovic, Daniela; Xing, Zhou

    2015-09-15

    Emerging evidence suggests a role of B cells in host defense against primary pulmonary tuberculosis (TB). However, the role of B cells in TB vaccine-induced protective T cell immunity still remains unknown. Using a viral-vectored model TB vaccine and a number of experimental approaches, we have investigated the role of B cells in respiratory mucosal vaccine-induced T cell responses and protection against pulmonary TB. We found that respiratory mucosal vaccination activated Ag-specific B cell responses. Whereas respiratory mucosal vaccination elicited Ag-specific T cell responses in the airway and lung interstitium of genetic B cell-deficient (Jh(-/-) knockout [KO]) mice, the levels of airway T cell responses were lower than in wild-type hosts, which were associated with suboptimal protection against pulmonary Mycobacterium tuberculosis challenge. However, mucosal vaccination induced T cell responses in the airway and lung interstitium and protection in B cell-depleted wild-type mice to a similar extent as in B cell-competent hosts. Furthermore, by using an adoptive cell transfer approach, reconstitution of B cells in vaccinated Jh(-/-) KO mice did not enhance anti-TB protection. Moreover, respiratory mucosal vaccine-activated T cells alone were able to enhance anti-TB protection in SCID mice, and the transfer of vaccine-primed B cells alongside T cells did not further enhance such protection. Alternatively, adoptively transferring vaccine-primed T cells from Jh(-/-) KO mice into SCID mice only provided suboptimal protection. These data together suggest that B cells play a minimal role, and highlight a central role by T cells, in respiratory mucosal vaccine-induced protective immunity against M. tuberculosis.

  14. A Lipopolysaccharide from Pantoea Agglomerans Is a Promising Adjuvant for Sublingual Vaccines to Induce Systemic and Mucosal Immune Responses in Mice via TLR4 Pathway

    PubMed Central

    Kiyotoh, Eiji; Okazaki, Arimichi; Gomi, Yasuyuki; Tanimoto, Takeshi; Takeuchi, Osamu; Akira, Shizuo; Hori, Mitsuhiko

    2015-01-01

    A lipopolysaccharide from Pantoea agglomerans (LPSpa) has been applied to various fields for human use as a Toll-like receptor 4 ligand and its safety has been confirmed. Here, we showed for the first time the application of LPSpa as an effective mucosal adjuvant for activating vaccine-induced antigen specific immune responses. Mice sublingually immunized with influenza vaccine (HA split vaccine) with LPSpa induced both HA-specific IgG (systemic) and IgA (mucosal) antibody responses, which led to a significant increase in survival rate against lethal influenza virus challenge compared with subcutaneous vaccination. After sublingual administration of ovalbumin with LPSpa, ovalbumin-specific mucosal IgA responses were induced at both mucosal surfaces close to the immunized site and at remote mucosal surfaces. Sublingual administration of LPSpa evoked local antigen-uptake by dendritic cells in cervical lymph nodes. LPSpa induced cytokine production and the maturation and proliferation of innate immune cells via Toll-like receptor 4 in dendritic cells. Collectively, these results suggest that LPSpa can be used as an effective mucosal adjuvant to stimulate and activate local innate immune cells to improve and enhance mucosal vaccine potency against various pathogens. PMID:25978818

  15. Role of oxygen radicals and neutrophils in hemorrhagic shock-induced gastric mucosal injury

    SciTech Connect

    Smith, S.M.

    1987-01-01

    The role of oxygen radicals and neutrophils was examined in ischemia-reperfusion injury to the gastric mucosa in male Sprague-Dawley rats. Gastric mucosal clearance of /sup 51/Cr-labelled red blood cells was measured during a 30 minute control period, 30 minute ischemic period, and a 60 minute reperfusion period. In untreated rats, a dramatic rise in the leakage of /sup 51/Cr-labeled red blood cells into the gastric lumen was observed only during the reperfusion period. Ischemia-reperfusion was also associated with the formation of both grossly visible and histologically demonstrable mucosal lesions. Pretreatment with dimethylsulfoxide or deferoxamine largely prevented gastric bleeding and gross lesion formation, indicating that the hydroxyl radical, generated by the iron-catalyzed Haber-Weiss reaction, is the primary cytotoxic oxygen species involved in ischemia-reperfusion injury.

  16. Gut mucosal immunostimulation by lactic acid bacteria.

    PubMed

    Vitiñi, E; Alvarez, S; Medina, M; Medici, M; de Budeguer, M V; Perdigón, G

    2000-12-01

    The beneficial properties of lactic acid bacteria (LAB) on human health have been frequently demonstrated. The interaction of LAB with the lymphoid cells associated to the gut to activate the mucosal immune system and the mechanisms by which they can exert an adjuvant effect is still unclear, as well as if this property is common for all the LAB. We studied the influence of the oral administration of different geneous of LAB such as Lactobacillus casei, L. acidophilus, L. rhamnosus, L. delbrueckii subsp. bulgaricus, L. plantarum, Lactococcus lactis and Streptococcus thermophilus. We determined if the LAB assayed were able to stimulate the specific, the non-specific immune response (inflammatory response), or both. We demonstrated that all the bacteria assayed were able to increase the number of IgA producing cells associated to the lamina propria of small intestine. This effect was dose dependent. The increase in IgA+ producing cells was not always correlated with an increase in the CD4+ T cell number, indicating that some LAB assayed only induced clonal expansion of B cells triggered to produce IgA. Most of them, induced an increase in the number of cells involved in the inflammatory immune response. CD8+ T cell were diminished or not affected, with exception of L. plantarum that induced an increase at low dose. This fact would mean that LAB are unable to induce cytotoxicity mechanisms. We demonstrated the importance in the selection of LAB to be used as gut mucosal adjuvant. The different behaviours observed among them on the gut mucosal immune response, specially those that induce inflammatory immune response, show that not all the LAB can be used as oral adjuvant and that the beneficial effect of them can not generalized to genous or specie. The immunoadjuvant capacity would be a property of the strain assayed.

  17. Glycerol monolaurate prevents mucosal SIV transmission

    PubMed Central

    Li, Qingsheng; Estes, Jacob D.; Schlievert, Patrick M.; Duan, Lijie; Brosnahan, Amanda J.; Southern, Peter J.; Reilly, Cavan S.; Peterson, Marnie L.; Schultz-Darken, Nancy; Brunner, Kevin G.; Nephew, Karla R.; Pambuccian, Stefan; Lifson, Jeffrey D.; Carlis, John V.; Haase, Ashley T.

    2009-01-01

    While there has been great progress in treating HIV-1 infection1, preventing transmission has thus far proven an elusive goal. Indeed, recent trials of a candidate vaccine and microbicide have been disappointing, both for want of efficacy and concerns about increased rates of transmission2–4. Nonetheless, studies of vaginal transmission in the SIV-rhesus macaque model point to opportunities in the earliest stages of infection where a vaccine or microbicide might be protective, by limiting the expansion of infected founder populations at the portal of entry5, 6. Here we show in this SIV-macaque model, that an outside-in endocervical mucosal signalling system, involving MIP-3α, plasmacytoid dendritic cells and CCR5+cell-attracting chemokines produced by these cells, in combination with the innate immune and inflammatory responses to infection in both cervix and vagina, recruit CD4+T cells to fuel this obligate expansion. We then show that glycerol monolaurate, a widely used antimicrobial compound 7 with inhibitory activity against production of MIP-3α and other proinflammatory cytokines8, can inhibit mucosal signalling and the innate and inflammatory response to HIV-1 and SIV in vitro, and in vivo can protect rhesus macaques from acute infection despite repeated intra-vaginal exposure to high doses of SIV. This novel approach, plausibly linked to interfering with innate host responses that recruit the target cells necessary to establish systemic infection, opens a promising new avenue for development of effective interventions to block HIV-1 mucosal transmission. PMID:19262509

  18. Multiscale modeling of mucosal immune responses

    PubMed Central

    2015-01-01

    Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut

  19. Glycerol monolaurate prevents mucosal SIV transmission.

    PubMed

    Li, Qingsheng; Estes, Jacob D; Schlievert, Patrick M; Duan, Lijie; Brosnahan, Amanda J; Southern, Peter J; Reilly, Cavan S; Peterson, Marnie L; Schultz-Darken, Nancy; Brunner, Kevin G; Nephew, Karla R; Pambuccian, Stefan; Lifson, Jeffrey D; Carlis, John V; Haase, Ashley T

    2009-04-23

    Although there has been great progress in treating human immunodeficiency virus 1 (HIV-1) infection, preventing transmission has thus far proven an elusive goal. Indeed, recent trials of a candidate vaccine and microbicide have been disappointing, both for want of efficacy and concerns about increased rates of transmission. Nonetheless, studies of vaginal transmission in the simian immunodeficiency virus (SIV)-rhesus macaque (Macacca mulatta) model point to opportunities at the earliest stages of infection in which a vaccine or microbicide might be protective, by limiting the expansion of infected founder populations at the portal of entry. Here we show in this SIV-macaque model, that an outside-in endocervical mucosal signalling system, involving MIP-3alpha (also known as CCL20), plasmacytoid dendritic cells and CCR5(+ )cell-attracting chemokines produced by these cells, in combination with the innate immune and inflammatory responses to infection in both cervix and vagina, recruits CD4(+) T cells to fuel this obligate expansion. We then show that glycerol monolaurate-a widely used antimicrobial compound with inhibitory activity against the production of MIP-3alpha and other proinflammatory cytokines-can inhibit mucosal signalling and the innate and inflammatory response to HIV-1 and SIV in vitro, and in vivo it can protect rhesus macaques from acute infection despite repeated intra-vaginal exposure to high doses of SIV. This new approach, plausibly linked to interfering with innate host responses that recruit the target cells necessary to establish systemic infection, opens a promising new avenue for the development of effective interventions to block HIV-1 mucosal transmission.

  20. Vitamin D and mucosal immune function

    PubMed Central

    Sun, Jun

    2010-01-01

    Purpose of review Significant advances have been made in the characterization of Vitamin D and the Vitamin D receptor (VDR) in immune function. The studies of signaling pathways involved in the response to infection and inflammation have led to a more detailed understanding of the cellular response to Vitamin D through VDR. This review summarizes recent progress in understanding how Vitamin D contributes to mucosal immune function, particularly in relation to the molecular mechanisms by which Vitamin D and VDR influence mucosal immunity, bacterial infection, and inflammation. Recent findings Recently, it was shown that Vitamin D modulates the T cell antigen receptor, further demonstrating that Vitamin D has a nonclassical role in immunoregulation. The anti-inflammation and anti-infection functions for Vitamin D are newly identified and highly significant activities. Vitamin D/VDR have multiple critical functions in regulating the response to intestinal homeostasis, tight junctions, pathogen invasion, commensal bacterial colonization, antimicrobe peptide secretion, and mucosal defense. Interestingly, microorganisms modulate the VDR signaling pathway. Summary Vitamin D is known as a key player in calcium homeostasis and electrolyte and blood pressure regulation. Recently, important progress has been made in understanding how the noncanonical activities of Vitamin D influence the pathogenesis and prevention of human disease. Vitamin D and VDR are directly involved in T cell antigen receptor signaling. The involvement of Vitamin D/VDR in anti-inflammation and anti-infection represents a newly identified and highly significant activity for VDR. Studies have indicated that the dysregulation of VDR may lead to exaggerated inflammatory responses, raising the possibility that defects in Vitamin D and VDR signaling transduction may be linked to bacterial infection and chronic inflammation. Further characterization of Vitamin D/VDR will help elucidate the pathogenesis of

  1. Induction of mucosal immunity against herpes simplex virus by plasmid DNA immunization.

    PubMed Central

    Kuklin, N; Daheshia, M; Karem, K; Manickan, E; Rouse, B T

    1997-01-01

    The ability of mucosally delivered plasmid DNA encoding glycoprotein B (gB) of herpes simplex virus type 1 (HSV-1) to generate systemic as well as distal mucosal immunity was evaluated. BALB/c mice were immunized intranasally (i.n.) with gB DNA or DNA expressing beta-galactosidase (beta-Gal). Two days following immunization, gB and beta-Gal gene expression was detected by reverse transcription (RT)-PCR in lungs and cervical lymph nodes (CLN). Histological analysis showed that beta-Gal protein was expressed in vivo in the lungs and the CLN of animals immunized with i.n. administered beta-Gal DNA. The immune responses generated by i.n. administration of gB DNA with or without cholera toxin (CT) were compared to those generated by intramuscular (i.m.) gB DNA and i.n. live HSV administration. Three i.n. doses of gB DNA over a 3-week period resulted in a distal mucosal immunoglobulin A (IgA) response. In addition, the mucosal IgA response was enhanced by coadministration of CT with gB DNA. The i.m. route of immunization induced a strong IgG response in the serum and vagina but was inefficient in generating a mucosal IgA response. Antigen-specific cytokine ELISPOT analyses as well as the serum IgG1/IgG2a ratio indicated induction of stronger Th2 responses following the additional i.n. administration of CT compared to i.n. or i.m. gB DNA or i.n. live HSV immunization. In addition, mucosal immunization with gB DNA induced anti-HSV cell-mediated immunity in vivo as measured by delayed-type hypersensitivity. Although i.n. DNA immunization was an effective means of inducing mucosal antibody, it was inferior to i.m. DNA delivery in providing protection against lethal HSV challenge via the vaginal route. In addition, both i.m. and i.n. plasmid immunizations failed to generate an immune barrier to viral invasion of the mucosa. PMID:9060677

  2. Peptic activity and gastroduodenal mucosal damage.

    PubMed Central

    Raufman, J. P.

    1996-01-01

    This contribution reviews briefly the history of the discovery and characterization of peptic activity; secretory models and current concepts regarding the regulation of pepsinogen secretion; and evidence that pepsin is a necessary co-factor for gastroduodenal mucosal injury. Several animal studies indicate that peptic activity is required for acid- and nonsteroidal anti-inflammatory drug-induced gastroduodenal ulceration. A more vigorous approach to the development of anti-peptic drugs for the treatment of peptic ulcer disease is encouraged. Images Figure 1 PMID:9041694

  3. Effect of pd and dd reactions enhancement in deuterides TiD2, ZrD2 and Ta2D in the astrophysical energy range

    NASA Astrophysics Data System (ADS)

    Bystritskii, V. M.; Dudkin, G. N.; Filipowicz, M.; Huran, J.; Krylov, A. R.; Nechayev, B. A.; Padalko, V. N.; Pen'kov, F. M.; Philippov, A. V.; Tuleushev, Yu. Zh.

    2016-01-01

    Investigation of the pd-and dd-reactions in the ultralow energy (~keV) range is of great interest in the aspect of nuclear physics and astrophysics for developing of correct models of burning and evolution of stars. This report presents compendium of experimental results obtained at the pulsed plasma Hall accelerator (TPU, Tomsk). Most of those results are new, such as • temperature dependence of the neutron yield in the D( d, n)3He reaction in the ZrD2, Ta2D, TiD2 • potentials of electron screening and respective dependence of astrophysical S-factors in the dd-reaction for the deuteron collision energy in the range of 3-6 keV, with ZrD2, Ta2D temperature in the range of 20-200°C [1] • characteristics of the reaction d( p, γ)3He in the ultralow collision proton-deuterons energy range of 4-13 keV [2, 3] in ZrD2, Ta2D and TiD2 • observation of the neutron yield enhancement in the reaction D( d, n)3He at the ultralow deuteron collision energy due to channeling of deuterons in microscopic TiD2 with a face-centered cubic lattice type TiD1.73, oriented in the [100] direction [4]. The report includes discussion and comparison of the collected experimental results with the global data and calculations.

  4. Rhubarb extract partially improves mucosal integrity in chemotherapy-induced intestinal mucositis

    PubMed Central

    Bajic, Juliana E; Eden, Georgina L; Lampton, Lorrinne S; Cheah, Ker Y; Lymn, Kerry A; Pei, Jinxin V; Yool, Andrea J; Howarth, Gordon S

    2016-01-01

    AIM To investigate the effects of orally gavaged aqueous rhubarb extract (RE) on 5-fluorouracil (5-FU)-induced intestinal mucositis in rats. METHODS Female Dark Agouti rats (n = 8/group) were gavaged daily (1 mL) with water, high-dose RE (HDR; 200 mg/kg) or low-dose RE (LDR; 20mg/kg) for eight days. Intestinal mucositis was induced (day 5) with 5-FU (150 mg/kg) via intraperitoneal injection. Intestinal tissue samples were collected for myeloperoxidase (MPO) activity and histological examination. Xenopus oocytes expressing aquaporin 4 water channels were prepared to examine the effect of aqueous RE on cell volume, indicating a potential mechanism responsible for modulating net fluid absorption and secretion in the gastrointestinal tract. Statistical significance was assumed at P < 0.05 by one-way ANOVA. RESULTS Bodyweight was significantly reduced in rats administered 5-FU compared to healthy controls (P < 0.01). Rats administered 5-FU significantly increased intestinal MPO levels (≥ 307%; P < 0.001), compared to healthy controls. However, LDR attenuated this effect in 5-FU treated rats, significantly decreasing ileal MPO activity (by 45%; P < 0.05), as compared to 5-FU controls. 5-FU significantly reduced intestinal mucosal thickness (by ≥ 29% P < 0.001) as compared to healthy controls. LDR significantly increased ileal mucosal thickness in 5-FU treated rats (19%; P < 0.05) relative to 5-FU controls. In xenopus oocytes expressing AQP4 water channels, RE selectively blocked water influx into the cell, induced by a decrease in external osmotic pressure. As water efflux was unaltered by the presence of extracellular RE, the directional flow of water across the epithelial barrier, in the presence of extracellular RE, indicated that RE may alleviate water loss across the epithelial barrier and promote intestinal health in chemotherapy-induced intestinal mucositis. CONCLUSION In summary, low dose RE improves selected parameters of mucosal integrity and reduces ileal

  5. The development of mucosal vaccines for both mucosal and systemic immune induction and the roles played by adjuvants

    PubMed Central

    2017-01-01

    Vaccination is the most successful immunological practice that improves the quality of human life and health. Vaccine materials include antigens of pathogens and adjuvants potentiating the effectiveness of vaccination. Vaccines are categorized using various criteria, including the vaccination material used and the method of administration. Traditionally, vaccines have been injected via needles. However, given that most pathogens first infect mucosal surfaces, there is increasing interest in the establishment of protective mucosal immunity, achieved by vaccination via mucosal routes. This review summarizes recent developments in mucosal vaccines and their associated adjuvants. PMID:28168169

  6. Visible to near-infrared plasmon-enhanced catalytic activity of Pd hexagonal nanoplates for the Suzuki coupling reaction

    NASA Astrophysics Data System (ADS)

    Trinh, T. Thuy; Sato, Ryota; Sakamoto, Masanori; Fujiyoshi, Yoshifumi; Haruta, Mitsutaka; Kurata, Hiroki; Teranishi, Toshiharu

    2015-07-01

    Photocatalytic conversion of solar energy to chemical energy is an efficient process in green chemistry because it facilitates room temperature chemical transformations by generating electronically excited states in photocatalysts. We report here on the robust synthesis, detailed structural characterization, and especially photocatalytic properties of plasmonic Pd hexagonal nanoplates for chemical reactions. The Pd hexagonal nanoplates are twin crystals, and composed of the top and bottom faces enclosed by the {111} planes with stacking faults and the side surfaces bound by mixed six {111} and six {100} planes. The Pd hexagonal nanoplates with well-defined and tunable longitudinal localized surface plasmon resonance (LSPR) have enabled the direct harvesting of visible to near-infrared light for catalytic cross coupling reactions. Upon plasmon excitation, the catalytic Suzuki coupling reactions of iodobenzene and phenylboronic acid accelerate by a plasmonic photocatalytic effect of plasmon induced hot electrons. The turnover frequency (TOF) of the Pd hexagonal nanoplates in a reaction illuminated with a λ = 300-1000 nm Xenon lamp at 176 mW cm-2 was 2.5 and 2.7 times higher than that of non-plasmonic {111}-enclosed Pd nanooctahedra and {100}-enclosed Pd nanocubes, respectively, and 1.7 times higher than the TOF obtained when the reaction was thermally heated to the same temperature.Photocatalytic conversion of solar energy to chemical energy is an efficient process in green chemistry because it facilitates room temperature chemical transformations by generating electronically excited states in photocatalysts. We report here on the robust synthesis, detailed structural characterization, and especially photocatalytic properties of plasmonic Pd hexagonal nanoplates for chemical reactions. The Pd hexagonal nanoplates are twin crystals, and composed of the top and bottom faces enclosed by the {111} planes with stacking faults and the side surfaces bound by mixed six {111

  7. Enhancement of a solar photo-Fenton reaction with ferric-organic ligands for the treatment of acrylic-textile dyeing wastewater.

    PubMed

    Soares, Petrick A; Batalha, Mauro; Souza, Selene M A Guelli U; Boaventura, Rui A R; Vilar, Vítor J P

    2015-04-01

    Literature describes a kinetic mineralization profile for most of acrylic-textile dyeing wastewaters using a photo-Fenton reaction characterized by a slow degradation process and high reactants consumption. This work tries to elucidate that the slow decay on DOC concentration is associated with the formation of stable complexes between Fe(3+) and textile auxiliary products, limiting the photoreduction of Fe(3+). This work also evaluates the enhancement of a solar photo-Fenton reaction through the use of different ferric-organic ligands applied to the treatment of a simulated acrylic-textile dyeing wastewater, as a pre-oxidation step to enhance its biodegradability. The photo-Fenton reaction was negatively affected by two dyeing auxiliary products: i) Sera(®) Tard A-AS, a surfactant mainly composed of alkyl dimethyl benzyl ammonium chloride and ii) Sera(®) Sperse M-IW, a dispersing agent composed of polyglycol solvents. The catalytic activity of the organic ligands toward the ferrous-catalysed system followed this order: Fe(III)-Oxalate > Fe(III)-Citrate > Fe(III)-EDDS, and all were better than the traditional photo-Fenton reaction. Different design parameters such as iron concentration, pH, temperature, flow conditions, UV irradiance and H2O2 addition strategy and dose were evaluated. The ferrioxalate induced photo-Fenton process presented the best results, achieving 87% mineralization after 9.3 kJUV L(-1) and allowing to work until near neutral pH values. As expected, the biodegradability of the textile wastewater was significantly enhanced during the photo-Fenton treatment, achieving a value of 73%, consuming 32.4 mM of H2O2 and 5.7 kJUV L(-1).

  8. On-the-fly detection of changes on and below the surface in epithelium mucosal tissue architecture from scattered light.

    PubMed

    Cohen, Fernand S; Taslidere, Ezgi; Murthy, Sreekant

    2011-04-01

    In this paper we present a technique to raise a flag on the fly when a transition occurs between different mucosal architectures on or below the surface. The segmentation is based on a novel difference metric for detecting an abrupt change in the parameters extracted from a Stochastic Decomposition Method (SDM) that models the scattered light reflected from the mucosal tissue structure over an area (2-D scan) illuminated by an optical sensor (fiber) emitting light at either one wavelength or with white light. This work has the potential to enhance the endoscopist's ability to locate and identify abnormal mucosal architectures in particular when the disease is developing below the surface and hence becoming hidden during colonoscopy or endoscopic examination. It also has also potential in helping deciding as to when and where to take biopsies; steps that should lead to improvement in the diagnostic yield.

  9. Dexmedetomidine decreases the oral mucosal blood flow.

    PubMed

    Kawaai, Hiroyoshi; Yoshida, Kenji; Tanaka, Eri; Togami, Kohei; Tada, Hitoshi; Ganzberg, Steven; Yamazaki, Shinya

    2013-12-01

    There is an abundance of blood vessels in the oral cavity, and intraoperative bleeding can disrupt operations. There have been some interesting reports about constriction of vessels in the oral cavity, one of which reported that gingival blood flow in cats is controlled by sympathetic α-adrenergic fibres that are involved with vasoconstriction. Dexmedetomidine is a sedative and analgesic agent that acts through the α-2 adrenoceptor, and is expected to have a vasoconstrictive action in the oral cavity. We have focused on the relation between the effects of α-adrenoceptors by dexmedetomidine and vasoconstriction in oral tissues, and assessed the oral mucosal blood flow during sedation with dexmedetomidine. The subjects comprised 13 healthy male volunteers, sedated with dexmedetomidine in a loading dose of 6 μg/kg/h for 10 min and a continuous infusion of 0.7 μg/kg/h for 32 min. The mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), stroke volume (SV), systemic vascular resistance (SVR), and palatal mucosal blood flow (PMBF) were measured at 0, 5, 10, 12, 22, and 32 min after the start of the infusion. The HR, CO, and PBMF decreased significantly during the infusion even though there were no differences in the SV. The SVR increased significantly but the PMBF decreased significantly. In conclusion, PMBF was reduced by the mediating effect of dexmedetomidine on α-2 adrenoceptors.

  10. Th17 cells and Mucosal Host Defense

    PubMed Central

    Aujla, Shean J.; Dubin, Patricia J.; Kolls, Jay K.

    2008-01-01

    Th17 cells are a new lineage of T-cells that are controlled by the transcription factor RORγt and develop independent of GATA-3, T-bet, Stat 4 and Stat 6. Novel effector molecules produced by these cells include IL-17A, IL-17F, IL-22, and IL-26. IL-17RA binds IL-17A and IL-17F and is critical for host defense against extracellular planktonic bacteria by regulating chemokine gradients for neutrophil emigration into infected tissue sites as well as host granulopoiesis. Moreover IL-17 and IL-22 regulate the production of antimicrobial proteins in mucosal epithelium. Although TGF-β1 and IL-6 have been shown to be critical for development of Th17 cells from naïve precursors, IL-23 is also important in regulating IL-17 release in mucosal tissues in response to infectious stimuli. Compared to Th1 cells, IL-23 and IL-17 show limited roles in controlling host defense against primary infections with intracellular bacteria such as Mycobacterium tuberculosis suggesting a predominate role of the Th17 lineage in host defense against extracellular pathogens. However in the setting of chronic biofilm infections, as that occurs with Cystic Fibrosis or bronchetctasis, Th17 cells may be key contributors of tissue injury. PMID:18054248

  11. Significant mucosal sIgA production after a single oral or parenteral administration using in vivo CD40 targeting in the chicken.

    PubMed

    Chou, Wen-Ko; Chen, Chang-Hsin; Vuong, Christine N; Abi-Ghanem, Daad; Waghela, Suryakant D; Mwangi, Waithaka; Bielke, Lisa R; Hargis, Billy M; Berghman, Luc R

    2016-10-01

    Many pathogens enter the host through mucosal surfaces and spread rapidly via the circulation. The most effective way to prevent disease is to establish mucosal and systemic immunity against the pathogen. However, current vaccination programs in poultry industry require repeated administrations of live-attenuated virus or large amounts (10 to 100μg) of antigen together with adjuvant to induce specific secretory IgA immune responses at the mucosal effector sites. In the present study, we show that a single administration of 0.4μg of oligopeptide complexed with an agonistic anti-chicken CD40 (chCD40) monoclonal antibody (Mab) effectively targets antigen-presenting cells of the bird's mucosa-associated lymphoid tissue in vivo, and induces peptide-specific secretory IgA (sIgA) in the trachea 7days post administration. Anti-chCD40 Mab-peptide complex was administered once to four-week old male Leghorns via various mucosal routes (orally, via cloacal drinking, or oculo-nasally) or via subcutaneous (s.c.) immunization. Immunization through any of the three mucosal induction routes induced significant peptide-specific mucosal sIgA responses 7 and 14days after immunization. Interestingly, s.c. injection of the complex also induced mucosal sIgA. Our data suggest in vivo targeting of CD40 as a potential adjuvant platform, particularly for the purpose of enhancing and speeding up mucosal vaccine responses in chickens, and potentially other food animals. This is the first study able to elicit specific sIgA immune responses in remote mucosal sites with a single administration of only 0.4μg of antigen.

  12. Characterization of a Rhodobacter capsulatus reaction center mutant that enhances the distinction between spectral forms of the initial electron donor.

    PubMed

    Eastman, J E; Taguchi, A K; Lin, S; Jackson, J A; Woodbury, N W

    2000-12-05

    A large scale mutation of the Rhodobacter capsulatus reaction center M-subunit gene, sym2-1, has been constructed in which amino acid residues M205-M210 have been changed to the corresponding L subunit amino acids. Two interconvertable spectral forms of the initial electron donor are observed in isolated reaction centers from this mutant. Which conformation dominates depends on ionic strength, the nature of the detergent used, and the temperature. Reaction centers from this mutant have a ground-state absorbance spectrum that is very similar to wild-type when measured immediately after purification in the presence of high salt. However, upon subsequent dialysis against a low ionic strength buffer or the addition of positively charged detergents, the near-infrared spectral band of P (the initial electron donor) in sym2-1 reaction centers is shifted by over 30 nm to the blue, from 852 to 820 nm. Systematically varying either the ionic strength or the amount of charged detergent reveals an isobestic point in the absorbance spectrum at 845 nm. The wild-type spectrum also shifts with ionic strength or detergent with an isobestic point at 860 nm. The large spectral separation between the two dominant conformational forms of the sym2-1 reaction center makes detailed measurements of each state possible. Both of the spectral forms of P bleach in the presence of light. Electrochemical measurements of the P/P+ midpoint potential of sym2-1 reaction centers show an increase of about 30 mV upon conversion from the long-wavelength form to the short-wavelength form of the mutant. The rate constant of initial electron transfer in both forms of the mutant reaction centers is essentially the same, suggesting that the spectral characteristics of P are not critical for charge separation. The short-wavelength form of P in this mutant also converts to the long-wavelength form as a function of temperature between room temperature and 130 K, again giving rise to an isobestic point, in this

  13. Minimally invasive treatment of oral ranula with a mucosal tunnel.

    PubMed

    Jia, T; Xing, L; Zhu, F; Jin, X; Liu, L; Tao, J; Chen, Y; Gao, Z; Zhang, H

    2015-02-01

    We have developed a new method for minimally-invasive treatment of uncomplicated oral ranulas using a mucosal tunnel, and we report the clinical outcome. We constructed a mucosal tunnel for each of 35 patients who presented with an oral ranula, by making 2 parallel incisions across the top of the protruding ranula 2-3mm apart, and dissected the soft tissue along the incisions to its wall. The fluid was removed and the cavity irrigated with normal saline. The wall of the ranula was not treated. The first mucosal tunnel was made by suturing the base of the mucosal strip to the deepest part of the wall of the ranula. The mucosal base of the tunnel and the deepest part of the base of the ranula were fixed with absorbable sutures. The two external edges of the incisions were sutured together to form the second mucosal tunnel, and apposing sutures were inserted between the two parallel incisions to form two natural mucosal tunnels. The duration of follow-up ranged from 1 to 5 years. One patient was lost to follow-up and 34 patients were cured. Outcomes were satisfactory without relapse during the follow-up period and the patients were satisfied with the outcome. The mucosal tunnel is a safe, effective, simple, and minimally-invasive treatment for oral ranula.

  14. Induction of mucosal immunity through systemic immunization: Phantom or reality?

    PubMed Central

    Su, Fei; Patel, Girishchandra B.; Hu, Songhua; Chen, Wangxue

    2016-01-01

    ABSTRACT Generation of protective immunity at mucosal surfaces can greatly assist the host defense against pathogens which either cause disease at the mucosal epithelial barriers or enter the host through these surfaces. Although mucosal routes of immunization, such as intranasal and oral, are being intensely explored and appear promising for eliciting protective mucosal immunity in mammals, their application in clinical practice has been limited due to technical and safety related challenges. Most of the currently approved human vaccines are administered via systemic (such as intramuscular and subcutaneous) routes. Whereas these routes are acknowledged as being capable to elicit antigen-specific systemic humoral and cell-mediated immune responses, they are generally perceived as incapable of generating IgA responses or protective mucosal immunity. Nevertheless, currently licensed systemic vaccines do provide effective protection against mucosal pathogens such as influenza viruses and Streptococcus pneumoniae. However, whether systemic immunization induces protective mucosal immunity remains a controversial topic. Here we reviewed the current literature and discussed the potential of systemic routes of immunization for the induction of mucosal immunity. PMID:26752023

  15. OCT visualization of acute radiation mucositis: pilot study

    NASA Astrophysics Data System (ADS)

    Gladkova, Natalia; Maslennikova, Anna; Terentieva, Anna; Fomina, Yulia; Khomutinnikova, Nina; Balalaeva, Irina; Vyseltseva, Yulia; Larin, Roman; Kornoukhova, Natalia; Shakhov, Andrey; Shakhova, Natalia; Gelikonov, Grigory; Kamensky, Vladislav; Feldchtein, Felix

    2005-08-01

    We present pilot results in optical coherence tomography (OCT) visualization of normal mucosa radiation damage. 15 patients undergoing radiation treatment of head and neck cancer were enrolled. OCT was used to monitor the mucositis development during and after treatment. OCT can see stages of radiation mucositis development, including hidden ones, before any clinical manifestations.

  16. Heat enhanced by an exothermic reaction on a fully developed MHD mixed convection flow in a vertical channel

    NASA Astrophysics Data System (ADS)

    Jayabalan, C.; Sivagnana Prabhu, K. K.; Kandasamy, R.

    2016-09-01

    The problem of a fully developed MHD mixed convection flow in a vertical channel with the first-order chemical reaction is analyzed. The dimensionless governing ordinary differential equations are solved numerically by using the Maple 18 software. It is observed that dual solutions exist for both velocity and temperature.

  17. Enhancing Treatment for School-Age Children Who Stutter I. Reducing Negative Reactions through Desensitization and Cognitive Restructuring

    ERIC Educational Resources Information Center

    Murphy, William P.; Yaruss, J. Scott; Quesal, Robert W.

    2007-01-01

    This paper describes several treatment strategies that clinicians can use to address negative affective, behavioral, and cognitive reactions that school-age children who stutter may experience as part of their disorder. Specific strategies include desensitization to stuttering, cognitive restructuring, self-acceptance, purposeful self-disclosure,…

  18. Recent progress in HIV vaccines inducing mucosal immune responses.

    PubMed

    Pavot, Vincent; Rochereau, Nicolas; Lawrence, Philip; Girard, Marc P; Genin, Christian; Verrier, Bernard; Paul, Stéphane

    2014-07-31

    In spite of several attempts over many years at developing a HIV vaccine based on classical strategies, none has convincingly succeeded to date. As HIV is transmitted primarily by the mucosal route, particularly through sexual intercourse, understanding antiviral immunity at mucosal sites is of major importance. An ideal vaccine should elicit HIV-specific antibodies and mucosal CD8⁺ cytotoxic T-lymphocyte (CTL) as a first line of defense at a very early stage of HIV infection, before the virus can disseminate into the secondary lymphoid organs in mucosal and systemic tissues. A primary focus of HIV preventive vaccine research is therefore the induction of protective immune responses in these crucial early stages of HIV infection. Numerous approaches are being studied in the field, including building upon the recent RV144 clinical trial. In this article, we will review current strategies and briefly discuss the use of adjuvants in designing HIV vaccines that induce mucosal immune responses.

  19. HIV and mucosal barrier interactions: consequences for transmission and pathogenesis.

    PubMed

    Burgener, Adam; McGowan, Ian; Klatt, Nichole R

    2015-10-01

    The mucosal barrier plays an integral function in human health as it is the primary defense against pathogens, and provides a critical transition between the external environment and the human internal body. In the context of HIV infection, the most relevant mucosal surfaces include those of the gastrointestinal (GI) and genital tract compartments. Several components help maintain the effectiveness of this mucosal surface, including the physical anatomy of the barrier, cellular immunity, soluble factors, and interactions between the epithelial barrier and the local microenvironment, including mucus and host microbiota. Any defects in barrier integrity or function can rapidly lead to an increase in acquisition risk, or with established infection may result in increased pathogenesis, morbidities, or mortality. Indeed, a key feature to all aspects of HIV infection from transmission to pathogenesis is disruption and/or dysfunction of mucosal barriers. Herein, we will detail the host-pathogen relationship of HIV and mucosal barriers in both of these scenarios.

  20. Enhancing the specificity of polymerase chain reaction by graphene oxide through surface modification: zwitterionic polymer is superior to other polymers with different charges.

    PubMed

    Zhong, Yong; Huang, Lihong; Zhang, Zhisen; Xiong, Yunjing; Sun, Liping; Weng, Jian

    Graphene oxides (GOs) with different surface characteristics, such as size, reduction degree and charge, are prepared, and their effects on the specificity of polymerase chain reaction (PCR) are investigated. In this study, we demonstrate that GO with a large size and high reduction degree is superior to small and nonreduced GO in enhancing the specificity of PCR. Negatively charged polyacrylic acid (PAA), positively charged polyacrylamide (PAM), neutral polyethylene glycol (PEG) and zwitterionic polymer poly(sulfobetaine) (pSB) are used to modify GO. The PCR specificity-enhancing ability increases in the following order: GO-PAA < GO-PAM < GO-PEG < GO-pSB. Thus, zwitterionic polymer-modified GO is superior to other GO derivatives with different charges in enhancing the specificity of PCR. GO derivatives are also successfully used to enhance the specificity of PCR for the amplification of human mitochondrial DNA using blood genomic DNA as template. Molecular dynamics simulations and molecular docking are performed to elucidate the interaction between the polymers and Pfu DNA polymerase. Our data demonstrate that the size, reduction degree and surface charge of GO affect the specificity of PCR. Based on our results, zwitterionic polymer-modified GO may be used as an efficient additive for enhancing the specificity of PCR.

  1. Enhancing the specificity of polymerase chain reaction by graphene oxide through surface modification: zwitterionic polymer is superior to other polymers with different charges

    PubMed Central

    Zhong, Yong; Huang, Lihong; Zhang, Zhisen; Xiong, Yunjing; Sun, Liping; Weng, Jian

    2016-01-01

    Graphene oxides (GOs) with different surface characteristics, such as size, reduction degree and charge, are prepared, and their effects on the specificity of polymerase chain reaction (PCR) are investigated. In this study, we demonstrate that GO with a large size and high reduction degree is superior to small and nonreduced GO in enhancing the specificity of PCR. Negatively charged polyacrylic acid (PAA), positively charged polyacrylamide (PAM), neutral polyethylene glycol (PEG) and zwitterionic polymer poly(sulfobetaine) (pSB) are used to modify GO. The PCR specificity-enhancing ability increases in the following order: GO-PAA < GO-PAM < GO-PEG < GO-pSB. Thus, zwitterionic polymer-modified GO is superior to other GO derivatives with different charges in enhancing the specificity of PCR. GO derivatives are also successfully used to enhance the specificity of PCR for the amplification of human mitochondrial DNA using blood genomic DNA as template. Molecular dynamics simulations and molecular docking are performed to elucidate the interaction between the polymers and Pfu DNA polymerase. Our data demonstrate that the size, reduction degree and surface charge of GO affect the specificity of PCR. Based on our results, zwitterionic polymer-modified GO may be used as an efficient additive for enhancing the specificity of PCR. PMID:27956830

  2. Enhanced organic pollutants degradation and electricity production simultaneously via strengthening the radicals reaction in a novel Fenton-photocatalytic fuel cell system.

    PubMed

    Zhao, Kai; Zeng, Qingyi; Bai, Jing; Li, Jinhua; Xia, Ligang; Chen, Shuai; Zhou, Baoxue

    2017-01-01

    An enhanced result in organic pollutants degradation and simultaneous electricity production has been achieved by establishing a novel Fenton-photocatalytic fuel cell (Fenton-PFC) system in which TiO2 nanotube arrays (TNA) was designed as a photoanode and ferrous ions were added. The proposed Fenton-PFC system can expand the radical reaction for organic pollutants degradation from the surface of electrodes to the whole solution system due to a continuous photoelectric Fenton reaction without continually adding any external voltage and ferrous ions. The cyclic reactions between ferrous ions (Fe(2+)/Fe(3+)) and radicals and related species (HO, HO2, O2(-) and H2O2 etc.) can be achieved at electrodes surface via a self-bias voltage yielded by the PFC. More importantly, the proposed Fenton-PFC system has hardly any sludge due to an effective radical reaction using a small amount of ferrous ions. The degradation rate of refractory organics, such as methyl orange, methylene blue, congo red and tetracycline, increased from 34.99%, 43.75%, 40.58% and 34.40% (the traditional PFC without Fe(2+)) to 97.34%, 95.36%, 93.23% and 73.80% (the Fenton-PFC within Fe(2+)) respectively after 60 min operation. Meanwhile, the electricity generation is up to 1.21-2.04 times larger than the traditional PFC. The proposed Fenton-PFC system provides a more economical and efficient way for energy recovery and wastewater treatment.

  3. Enhanced methanol electro-oxidation and oxygen reduction reaction performance of ultrafine nanoporous platinum-copper alloy: Experiment and density functional theory calculation

    NASA Astrophysics Data System (ADS)

    Sun, Junzhe; Shi, Jun; Xu, Junling; Chen, Xiaoting; Zhang, Zhonghua; Peng, Zhangquan

    2015-04-01

    Novel ultrafine nanoporous Pt-Cu alloy with a Pt:Cu stoichiometric ratio of 3:1 (np-Pt3Cu) has been prepared by mechanical alloying and subsequent two-step chemical dealloying. The obtained np-Pt3Cu has uniform and bicontinuous ligament(metal)-channel(void) structure with the ligament size of 3.3 ± 0.7 nm. To explore its potential application in energy conversion reactions, the np-Pt3Cu alloy has been examined as electrocatalyst for the operating reactions in direct methanol fuel cells (DMFCs). Compared with the commercial JM Pt/C, a benchmark catalyst extensively used in fuel cell research, the np-Pt3Cu alloy demonstrates better performance in both the methanol electro-oxidation and oxygen reduction reactions in acidic medium. Theoretical calculations reveal that the electronic structure of Pt has been modified with the shift of Pt d-band center due to alloying with Cu, which can decrease CO poisoning and enhance the methanol oxidation and oxygen reduction reaction activities.

  4. Pt-Decorated PdCo@Pd/C Core-Shell Nanoparticles with Enhanced Stability and Electrocatalytic Activity for the Oxygen Reduction Reaction

    SciTech Connect

    Wang, Deli; Xin, Huolin L.; Yu, Yingchao; Wang, Hongsen; Rus, Eric; Muller, David A.; Abruña, Héctor D.

    2010-11-24

    A simple method for the preparation of PdCo@Pd core-shell nanoparticles supported on carbon based on an adsorbate-induced surface segregation effect has been developed. The stability of these PdCo@Pd nanoparticles and their electrocatalytic activity for the oxygen reduction reaction (ORR) were enhanced by decoration with a small amount of Pt deposited via a spontaneous displacement reaction. The facile method described herein is suitable for large-scale, lower-cost production and significantly lowers the Pt loading and thus the cost. The as-prepared PdCo@Pd and Pd-decorated PdCo@Pd nanocatalysts have a higher methanol tolerance than Pt/C in the ORR and are promising cathode catalysts for fuel cell applications.

  5. Autologous Transplantation of Oral Mucosal Epithelial Cell Sheets Cultured on an Amniotic Membrane Substrate for Intraoral Mucosal Defects

    PubMed Central

    Amemiya, Takeshi; Nakamura, Takahiro; Yamamoto, Toshiro; Kinoshita, Shigeru; Kanamura, Narisato

    2015-01-01

    The human amniotic membrane (AM) is a thin intrauterine placental membrane that is highly biocompatible and possesses anti-inflammatory and anti-scarring properties. Using AM, we developed a novel method for cultivating oral mucosal epithelial cell sheets. We investigated the autologous transplantation of oral mucosal epithelial cells cultured on AM in patients undergoing oral surgeries. We obtained specimens of AM from women undergoing cesarean sections. This study included five patients without any history of a medical disorder who underwent autologous cultured oral epithelial transplantation following oral surgical procedures. Using oral mucosal biopsy specimens obtained from these patients, we cultured oral epithelial cells on an AM carrier. We transplanted the resultant cell sheets onto the oral mucosal defects. Patients were followed-up for at least 12 months after transplantation. After 2–3 weeks of being cultured on AM, epithelial cells were well differentiated and had stratified into five to seven layers. Immunohistochemistry revealed that the cultured cells expressed highly specific mucosal epithelial cell markers and basement membrane proteins. After the surgical procedures, no infection, bleeding, rejection, or sheet detachment occurred at the reconstructed sites, at which new oral mucous membranes were evident. No recurrence was observed in the long-term follow-up, and the postoperative course was excellent. Our results suggest that AM-cultured oral mucosal epithelial cell sheets represent a useful biomaterial and feasible method for oral mucosal reconstruction. However, our primary clinical study only evaluated their effects on a limited number of small oral mucosal defects. PMID:25915046

  6. Mechanisms of Enhanced Electrocatalytic Activity for Oxygen Reduction Reaction on High-Index Platinum n(111)-(111) Surfaces.

    PubMed

    Yue, Jeffrey; Du, Zheng; Shao, Minhua

    2015-09-03

    Oxygen reduction reactions (ORRs) on high-index planes of Pt n(111)-(111) were studied by density functional theory (DFT). The stepped surfaces, where n = 2, 3, and 4, showed that O2, O, and OH exhibited higher binding energies along the step compared to the terrace plane. The Pt atoms along the step can become distorted through the binding of the O and OH, where the shift in position of the Pt atoms is the largest along the stepped sites, hence forming stronger bonds with O atoms. One of the two O atoms produced from the bond dissociation of O2 will push the other one down a step with lower binding energies, consequently reducing the energy required for the protonation reaction (O + H(+) → OH, and OH + H(+) → H2O). The quicker recovery back to the clean Pt surface would therefore improve the catalytic properties of Pt nanoparticles, especially those with exposure to high-indexed facets.

  7. Carboxyl functionalization of carbon fibers via aryl diazonium reaction in molten urea to enhance interfacial shear strength

    NASA Astrophysics Data System (ADS)

    Wang, Yuwei; Meng, Linghui; Fan, Liquan; Wu, Guangshun; Ma, Lichun; Zhao, Min; Huang, Yudong

    2016-01-01

    Using molten urea as the solvent, carbon fibers were functionalized with carboxylic acid groups via aryl diazonium reaction in 15 min to improve their interfacial bonding with epoxy resin. The surface functionalization was quantified by X-ray photoelectron spectroscopy, which showed that the relative surface coverage of carboxylic acid groups increased from an initial percentage of 3.17-10.41%. Mechanical property test results indicated that the aryl diazonium reaction in this paper could improve the interfacial shear strength by 66%. Meanwhile, the technique did not adopt any pre-oxidation step to produce functional groups prior to grafting and was shown to maintain the tensile strength of the fibers. This methodology provided a rapid, facile and economically viable route to produce covalently functionalized carbon fibers in large quantities with an eco-friendly method.

  8. Minimization of steam requirements and enhancement of water-gas shift reaction with warm gas temperature CO2 removal

    DOEpatents

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

    The disclosure utilizes a hydroxide sorbent for humidification and CO.sub.2 removal from a gaseous stream comprised of CO and CO.sub.2 prior to entry into a water-gas-shift reactor, in order to decrease CO.sub.2 concentration and increase H.sub.2O concentration and shift the water-gas shift reaction toward the forward reaction products CO.sub.2 and H.sub.2. The hydroxide sorbent may be utilized for absorbtion of CO.sub.2 exiting the water-gas shift reactor, producing an enriched H.sub.2 stream. The disclosure further provides for regeneration of the hydroxide sorbent at temperature approximating water-gas shift conditions, and for utilizing H.sub.2O product liberated as a result of the CO.sub.2 absorption.

  9. Mutations in the TP53 gene in human malignant melanomas derived from sun-exposed skin and unexposed mucosal membranes.

    PubMed

    Ragnarsson-Olding, B K; Karsberg, S; Platz, A; Ringborg, U K

    2002-10-01

    Mutations in the p53 tumour suppressor gene ( ) have been linked to several types of cancer. We therefore investigated whether such mutations occur in malignant melanomas and, if so, whether they are linked to ultraviolet (sun) light exposure. For the first time, mutations in mucosal membranes and adjacent tissues shielded from sunlight were compared with those in cutaneous melanomas from sun-exposed skin. Archival tissues were obtained from 35 patients with a primary melanoma taken from unexposed mucosal areas and from 34 patients with a primary melanoma located in chronically sun-exposed head and neck skin. was characterized by means of polymerase chain reaction amplification and single-strand conformation polymorphism assay followed by nucleotide sequencing. The results showed that 17.6% of the primary cutaneous and 28.6% of the primary mucosal melanomas had point mutations in. Among the cutaneous melanomas, one showed three mutations in exon 7, and one had two mutations in exon 5; the mutation was in the same allele in both cases. One mucosal melanoma had two mutations in exon 7, both in the same allele, and another had two mutations, one in exon 7 and one in intron 6, both in the same allele. C<--T mutations at dipyrimidine sites, considered fingerprints for ultraviolet light-induced mutations, were about equally distributed among patients with melanomas from chronically sun-exposed areas (six out of nine; 67%) and those with melanomas from unexposed mucosal areas and adjacent skin (eight out of 14; 57%). Our data, demonstrating the presence of such mutations even in melanomas from mucosal membranes, clearly suggest that factors other than, or additional to, ultraviolet radiation are operational in the induction of mutations in melanomas.

  10. PMN-mediated immune reactions against Eimeria bovis.

    PubMed

    Behrendt, Jan Hillern; Hermosilla, Carlos; Hardt, Martin; Failing, Klaus; Zahner, Horst; Taubert, Anja

    2008-02-14

    For successful in vivo infection, Eimeria bovis sporozoites have to traverse the mucosal layer of the ileum to infect lymphatic endothelial cells and may, thereby, be exposed to the interstitial fluid and to the lymph representing potential targets for leukocytes. To mimic this situation in vitro, we exposed E. bovis sporozoites to bovine PMN and found enhanced elimination of the parasites. Addition of immune serum clearly increased these reactions, whereas neonatal calf serum had no effect, thus proposing a PMN-derived antibody-dependent cytotoxicity. Scanning and transmission electron microscopy showed PMN engulfing sporozoites or extending filopodia towards them and occasionally incorporating the parasites. PMN reacted with enhanced transcription of IL-6, MCP-1, GROalpha, TNF-alpha, and iNOS genes after exposure to sporozoites while stimulation with merozoite-antigen, in addition, upregulated IL-8, IP-10 and IL-12 gene transcription. Furthermore, enhanced in vitro oxidative burst and phagocytic activities were observed after contact of PMN with viable sporozoites. To verify the potential role of PMN in the in vivo situation, we analysed the general phagocytic and oxidative burst activities of PMN obtained ex vivo from E. bovis experimentally infected calves. Enhanced levels of both activities were found early p.i. (1-5 days) and towards the end of the first schizogony (days 13-22 p.i.) underlining the in vitro data. Our results suggest that PMN-mediated, innate immune reactions play an important role in the early immune response to E. bovis infections in calves.

  11. Surface-Limited Synthesis of Pt Nanocluster Decorated Pd Hierarchical Structures with Enhanced Electrocatalytic Activity toward Oxygen Reduction Reaction.

    PubMed

    Yang, Tao; Cao, Guojian; Huang, Qingli; Ma, Yanxia; Wan, Sheng; Zhao, Hong; Li, Na; Sun, Xia; Yin, Fujun

    2015-08-12

    Exploring superior catalysts with high catalytic activity and durability is of significant for the development of an electrochemical device involving the oxygen reduction reaction. This work describes the synthesis of Pt-on-Pd bimetallic heterogeneous nanostructures, and their high electrocatalytic activity toward the oxygen reduction reaction (ORR). Pt nanoclusters with a size of 1-2 nm were generated on Pd nanorods (NRs) through a modified Cu underpotential deposition (UPD) process free of potential control and a subsequent surface-limited redox reaction. The Pt nanocluster decorated Pd nanostructure with a ultralow Pt content of 1.5 wt % exhibited a mass activity of 105.3 mA mg(-1) (Pt-Pd) toward ORR, comparable to that of the commercial Pt/C catalyst but 4 times higher than that of carbon supported Pd NRs. More importantly, the carbon supported Pt-on-Pd catalyst displays relatively small losses of 16% in electrochemical surface area (ECSA) and 32% in mass activity after 10 000 potential sweeps, in contrast to respective losses of 46 and 64% for the commercial Pt/C catalyst counterpart. The results demonstrated that Pt decoration might be an efficient way to improve the electrocatalytic activity of Pd and in turn allow Pd to be a promising substitution for commercial Pt catalyst.

  12. Enhanced fluorescence and structural characteristics of carboxymethyl cellulose/Eu(III) nano-complex: Influence of reaction time.

    PubMed

    Ye, Jun; Wang, Ben; Xiong, Jian; Sun, Runcang

    2016-01-01

    CMC/Eu(III) nano-complexes were synthesized by reacting Eu(3+) with carboxymethyl cellulose (CMC). The SEM and EDS showed that particle size was less than 100nm and evenly distributed. FTIR and XPS indicated that the oxygen atoms in COO (-), OH, and COC were involved in the complexation with Eu(3+), yet, the O atoms were involved in different positions on anhydroglucose rings depending on reaction time. It was found that there were good energy matches between energy levels on ground state of CMC and (5)D0 Eu(III). Moreover, the intensities of (5)D0→(7)F2 of the nano-complexes were stronger than that of (5)D0→(7)F1, which indicated that the Eu(III) was not in the center of symmetry. The optimized reaction time was 35min, at this reaction time the smallest particle size and uniform distribution was obtained, the coordination structure was advantageous for the energy absorption transfer and emission.

  13. Optimization of Maillard reaction with ribose for enhancing anti-allergy effect of fish protein hydrolysates using response surface methodology.

    PubMed

    Yang, Sung-Yong; Kim, Se-Wook; Kim, Yoonsook; Lee, Sang-Hoon; Jeon, Hyeonjin; Lee, Kwang-Won

    2015-06-01

    Halibut is served on sushi and as sliced raw fish fillets. We investigated the optimal conditions of the Maillard reaction (MR) with ribose using response surface methodology to reduce the allergenicity of its protein. A 3-factored and 5-leveled central composite design was used, where the independent variables were substrate (ribose) concentration (X1, %), reaction time (X2, min), and pH (X3), while the dependent variables were browning index (Y1, absorbance at 420nm), DPPH scavenging (Y2, EC50 mg/mL), FRAP (Y3, mM FeSO4/mg extract) and β-hexosaminidase release (Y4, %). The optimal conditions were obtained as follows: X1, 28.36%; X2, 38.09min; X3, 8.26. Maillard reaction products of fish protein hydrolysate (MFPH) reduced the amount of nitric oxide synthesis compared to the untreated FPH, and had a significant anti-allergy effect on β-hexosaminidase and histamine release, compared with that of the FPH control. We concluded that MFPH, which had better antioxidant and anti-allergy activities than untreated FPH, can be used as an improved dietary source.

  14. Mucosal Antibodies to the C Terminus of Toxin A Prevent Colonization of Clostridium difficile.

    PubMed

    Hong, Huynh A; Hitri, Krisztina; Hosseini, Siamand; Kotowicz, Natalia; Bryan, Donna; Mawas, Fatme; Wilkinson, Anthony J; van Broekhoven, Annie; Kearsey, Jonathan; Cutting, Simon M

    2017-04-01

    Mucosal immunity is considered important for protection against Clostridium difficile infection (CDI). We show that in hamsters immunized with Bacillus subtilis spores expressing a carboxy-terminal segment (TcdA26-39) of C. difficile toxin A, no colonization occurs in protected animals when challenged with C. difficile strain 630. In contrast, animals immunized with toxoids showed no protection and remained fully colonized. Along with neutralizing toxins, antibodies to TcdA26-39 (but not to toxoids), whether raised to the recombinant protein or to TcdA26-39 expressed on the B. subtilis spore surface, cross-react with a number of seemingly unrelated proteins expressed on the vegetative cell surface or spore coat of C. difficile These include two dehydrogenases, AdhE1 and LdhA, as well as the CdeC protein that is present on the spore. Anti-TcdA26-39 mucosal antibodies obtained following immunization with recombinant B. subtilis spores were able to reduce the adhesion of C. difficile to mucus-producing intestinal cells. This cross-reaction is intriguing yet important since it illustrates the importance of mucosal immunity for complete protection against CDI.

  15. Synthesis of unsymmetric bipyridine-Pt(II) -alkynyl complexes through post-click reaction with emission enhancement characteristics and their applications as phosphorescent organic light-emitting diodes.

    PubMed

    Li, Yongguang; Tsang, Daniel Ping-Kuen; Chan, Carmen Ka-Man; Wong, Keith Man-Chung; Chan, Mei-Yee; Yam, Vivian Wing-Wah

    2014-10-13

    Two unsymmetric bipyridine-platinum(II)-alkynyl complexes have been synthesised by a post-click reaction. These metal complexes are found to exhibit emission enhancement properties. The photoluminescence quantum yield can be significantly increased from 0.03 in solution to 0.72 in solid-state thin films. Efficient solution-processable organic light-emitting diodes have been fabricated by utilizing these complexes as phosphorescent dopants. A high external quantum efficiency of up to 5.8% has been achieved.

  16. NRAS and BRAF mutation frequency in primary oral mucosal melanoma.

    PubMed

    Buery, Rosario Rivera; Siar, Chong Huat; Katase, Naoki; Gunduz, Mehmet; Lefeuvre, Mathieu; Fujii, Masae; Inoue, Masahisa; Setsu, Kojun; Nagatsuka, Hitoshi

    2011-10-01

    Oral mucosal melanoma (OMM) is a fatal sarcoma of unknown etiology. Histological morphology and genetic events are distinct from those of its cutaneous counterpart. Mutation and up-regulation of c-kit has been identified in OMM which may activate downstream molecules such as RAS and RAF. These molecules are involved in the mitogen-activated protein kinase (MAPK) pathway leading to tremendous cell proliferation and survival. NRAS and BRAF mutation and protein expression have been studied in other melanoma subtypes. The purpose of this study was to determine RAS protein expression and NRAS and BRAF mutation in 18 primary OMM cases using immunohistochemistry and mutation analysis. Results showed that RAS is intensely expressed in both in situ and invasive OMMs. However, NRAS mutation was only observed in 2/15 polymerase chain reaction (PCR) amplified cases both of which were silent mutations. On the other hand, BRAF missense mutations were observed only in 1/15 cases with PCR amplification. NRAS and BRAF mutations were independent from previously reported c-kit mutations. The classical V600E BRAF mutation was not found; instead a novel V600L was observed suggesting that the oncogenic event in OMM is different from that in skin melanoma. The low frequency of NRAS and BRAF mutations indicate that these genes are not common, but probable events in OMM pathogenesis, most likely independent of c-kit mutation.

  17. Cyclosporin metabolism by human gastrointestinal mucosal microsomes.

    PubMed Central

    Webber, I R; Peters, W H; Back, D J

    1992-01-01

    The in vitro metabolism of the immunosuppressant cyclosporin (CsA) by human gastrointestinal mucosal microsomes has been studied. Macroscopically normal intestinal (n = 4) and liver (n = 2) tissue was obtained from kidney transplant donors, and microsomes prepared. Intestinal metabolism was most extensive with duodenal protein (15% conversion to metabolites M1/M17 after 2 h incubation at 37 degrees C; metabolite measurement by h.p.l.c). Western blotting confirmed the presence of P-4503A (enzyme subfamily responsible for CsA metabolism) in duodenum and ileum tissue, but not in colon tissue. The results of this study indicate that the gut wall may play a role in the first-pass metabolism of CsA, and could therefore be a contributory factor to the highly variable oral bioavailability of CsA. PMID:1389941

  18. Mucosal cytokine network in inflammatory bowel disease

    PubMed Central

    Andoh, Akira; Yagi, Yuhki; Shioya, Makoto; Nishida, Atsushi; Tsujikawa, Tomoyuki; Fujiyama, Yoshihide

    2008-01-01

    Inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohn’s disease (CD) are characterized by ongoing mucosal inflammation in which dysfunction of the host immunologic response against dietary factors and commensal bacteria is involved. The chronic inflammatory process leads to disruption of the epithelial barrier, and the formation of epithelial ulceration. This permits easy access for the luminal microbiota and dietary antigens to cells resident in the lamina propria, and stimulates further pathological immune cell responses. Cytokines are essential mediators of the interactions between activated immune cells and non-immune cells, including epithelial and mesenchymal cells. The clinical efficacy of targeting TNF-α clearly indicates that cytokines are the therapeutic targets in IBD patients. In this manuscript, we focus on the biological activities of recently-reported cytokines [Interleukin (IL)-17 cytokine family, IL-31 and IL-32], which might play a role through interaction with TNF-α in the pathophysiology of IBD. PMID:18777592

  19. LETTER TO THE EDITOR: Polarization enhancement in &vec{d}(\\vec{p},\\vec{n})^{2};He reaction: nuclear teleportation

    NASA Astrophysics Data System (ADS)

    Hamieh, S.

    2004-02-01

    I show that an experimental technique used in nuclear physics may be successfully applied to quantum teleportation (QT) of spin states of massive matter. A new non-local physical effect, the 'quantum-teleportation effect', is discovered for the nuclear polarization measurement. Enhancement of the neutron polarization is expected in the proposed experiment for QT that discriminates only one of the Bell states.

  20. Enhanced Peroxide Resistance of In Vitro Mutagenized Fluorideresistant Klebsiella pneumoniae Ureases for Catalytic Buffering of Agent Decontamination Reactions

    DTIC Science & Technology

    2004-11-17

    1 ENHANCED PEROXIDE RESISTANCE OF IN VITRO MUTAGENIZED FLUORIDE- RESISTANT Klebsiella pneumoniae UREASES FOR CATALYTIC BUFFERING OF...oxidative surety agent decontamination technologies. Ammonia production from urea by urease neutralizes the production of O- alkylphosphonic acids...resulting from the hydrolysis of Nerve agents such as Sarin and VX. Fluoride production from Sarin hydrolysis inhibits native urease at low mM

  1. Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations.

    PubMed

    Sato, T; Ramirez-Cuesta, A J; Daemen, L; Cheng, Y-Q; Tomiyasu, K; Takagi, S; Orimo, S

    2016-09-27

    Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4](-) was investigated using inelastic neutron scattering viewed from vibrational dynamics. The hydrogen release followed the softening of translational and [AlH4](-) librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

  2. ROLE OF REDUCTANTS IN THE ENHANCED DESORPTION AND TRANSFORMATION OF CHOROALIPHATIC COMPOUNDS BY MODIFIED FENTON'S REACTIONS. (R826163)

    EPA Science Inventory

    The mechanism for enhanced desorption of chloroaliphatic compounds from a
    silty loam soil by modified Fenton's reagent was investigated using a series of
    probe compounds of varying hydrophobicities. Hexachloroethane, which has
    negligible reactivity with hydroxyl ra...

  3. Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations

    DOE PAGES

    Sato, T.; Ramirez-Cuesta, Anibal J.; Daemen, Luke L.; ...

    2016-08-31

    Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4]– was investigated using inelastic neutron scattering viewed from vibrational dynamics. Here, the hydrogen release followed the softening of translational and [AlH4]– librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

  4. Microbes and mucosal immune responses in asthma.

    PubMed

    Hansel, Trevor T; Johnston, Sebastian L; Openshaw, Peter J

    2013-03-09

    The substantial increase in the worldwide prevalence of asthma and atopy has been attributed to lifestyle changes that reduce exposure to bacteria. A recent insight is that the largely bacterial microbiome maintains a state of basal immune homoeostasis, which modulates immune responses to microbial pathogens. However, some respiratory viral infections cause bronchiolitis of infancy and childhood wheeze, and can exacerbate established asthma; whereas allergens can partly mimic infectious agents. New insights into the host’s innate sensing systems, combined with recently developed methods that characterise commensal and pathogenic microbial exposure, now allow a unified theory for how microbes cause mucosal inflammation in asthma. The respiratory mucosa provides a key microbial interface where epithelial and dendritic cells interact with a range of functionally distinct lymphocytes. Lymphoid cells then control a range of pathways, both innate and specific, which organise the host mucosal immune response. Fundamental to innate immune responses to microbes are the interactions between pathogen-associated molecular patterns and pattern recognition receptors, which are associated with production of type I interferons, proinflammatory cytokines, and the T-helper-2 cell pathway in predisposed people. These coordinated, dynamic immune responses underlie the differing asthma phenotypes, which we delineate in terms of Seven Ages of Asthma. An understanding of the role of microbes in the atopic march towards asthma, and in causing exacerbations of established asthma, provides the rationale for new specific treatments that can be assessed in clinical trials. On the basis of these new ideas, specific host biomarkers might then allow personalised treatment to become a reality for patients with asthma.

  5. The oral mucosal surface and blood vessels

    PubMed Central

    2013-01-01

    Introduction Detailed information about the size of the oral mucosa is scarce in the literature, and those studies that do exist do not take into account the size of the tongue or the enlargement of the surface by the papillae. Because of the various functions of the oral mucosa in the maintenance of oral health, knowledge of its true size may provide a better understanding of the physiology of the oral cavity and some oral diseases and direct future therapeutic strategies. The aim of this study was to determine the total size of the oral mucosa. Methods Five human adult cadaver heads were cut in the median sagittal plane, and the total area of the oral surface was determined using silicon casts. The surface of the tongue was measured with quantitative profilometry. Photographs of oral blood vessels were taken in different areas of the oral mucosa of adult test subjects using intravital microscopy, and the pictures were compared with vessel casts of the oral mucosal capillaries of a maccaca fasciculrais monkey, which was studied using a scanning electron microscope. Results The results showed that the dorsal side of the tongue comprises a large proportion of the total oral mucosal surface. The surface area of the epithelium increases moving from anterior to posterior on the tongue, and the number of underlying blood vessels increases proportionally. Conclusions It can be concluded that the back of the tongue plays an important role in the oral resorption of drugs. Clinical relevance: The results may be of relevance for the delivery and development of oral drug application. PMID:23497446

  6. Natural Outbreak of BVDV-1d-Induced Mucosal Disease Lacking Intestinal Lesions.

    PubMed

    Bianchi, M V; Konradt, G; de Souza, S O; Bassuino, D M; Silveira, S; Mósena, A C S; Canal, C W; Pavarini, S P; Driemeier, D

    2017-03-01

    Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus, which is further divided into subgenotypes (1a-1u and 2a-c). When persistent infection occurs, the calf will be immunotolerant to BVDV and possibly develop mucosal disease. This study describes an outbreak of BVDV-1d-induced mucosal disease lacking intestinal lesions. Eleven calves presented with anorexia, sialorrhea, lameness, recumbency, and death. Three calves were necropsied, showing ulceration of the interdigital skin and the oral and nasal mucosa; linear ulcers in the tongue, esophagus, and rumen; and rounded ulcers in the abomasum. Microscopically, mucosa and skin had superficial necrosis, with single-cell necrosis and vacuolation in epithelial cells, and severe parakeratosis. Immunohistochemistry (IHC) showed BVDV antigen in the cytoplasm of epithelial cells in skin and mucosa. All 11 dead calves were positive upon reverse transcription-polymerase chain reaction (RT-PCR) for the detection of Pestivirus along with another 11 live calves from the herd, which were positive again by RT-PCR and IHC after a 4-week interval. Sequencing of the 5' untranslated region and N-terminal protease showed that viruses from these 22 calves were homologous and of subgenotype BVDV-1d. Cytopathic BVDV was isolated from 8 of 11 dead calves, but only noncytopathic BVDV was isolated from the 11 live animals. The findings indicate that this was an outbreak of mucosal disease caused by BVDV-1d, with high morbidity, and lesions restricted to the upper alimentary system and skin and absent from intestine. Thus, the epidemiological and pathological features in this form of mucosal disease may be similar to vesicular diseases, including foot and mouth disease.

  7. Lactococci and lactobacilli as mucosal delivery vectors for therapeutic proteins and DNA vaccines

    PubMed Central

    2011-01-01

    Food-grade Lactic Acid Bacteria (LAB) have been safely consumed for centuries by humans in fermented foods. Thus, they are good candidates to develop novel oral vectors, constituting attractive alternatives to attenuated pathogens, for mucosal delivery strategies. Herein, this review summarizes our research, up until now, on the use of LAB as mucosal delivery vectors for therapeutic proteins and DNA vaccines. Most of our work has been based on the model LAB Lactococcus lactis, for which we have developed efficient genetic tools, including expression signals and host strains, for the heterologous expression of therapeutic proteins such as antigens, cytokines and enzymes. Resulting recombinant lactococci strains have been tested successfully for their prophylactic and therapeutic effects in different animal models: i) against human papillomavirus type 16 (HPV-16)-induced tumors in mice, ii) to partially prevent a bovine β-lactoglobulin (BLG)-allergic reaction in mice and iii) to regulate body weight and food consumption in obese mice. Strikingly, all of these tools have been successfully transposed to the Lactobacillus genus, in recent years, within our laboratory. Notably, anti-oxidative Lactobacillus casei strains were constructed and tested in two chemically-induced colitis models. In parallel, we also developed a strategy based on the use of L. lactis to deliver DNA at the mucosal level, and were able to show that L. lactis is able to modulate the host response through DNA delivery. Today, we consider that all of our consistent data, together with those obtained by other groups, demonstrate and reinforce the interest of using LAB, particularly lactococci and lactobacilli strains, to develop novel therapeutic protein mucosal delivery vectors which should be tested now in human clinical trials. PMID:21995317

  8. Methylglyoxal modification enhances the stability of hemoglobin and lowers its iron-mediated oxidation reactions: An in vitro study.

    PubMed

    Banerjee, Sauradipta; Chakraborti, Abhay Sankar

    2017-02-01

    Post-translational modification of proteins by Maillard reaction, known as glycation, is thought to be the root cause of different complications, particularly in diabetes mellitus and age-related disorders. Methylglyoxal (MG), a reactive α-oxoaldehyde, increases in diabetic condition and reacts with proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. In the present study, we have investigated the in vitro effect of methylglyoxal (200, 300μm) on the heme protein hemoglobin (HbA0) (100μm) after incubation for one week at 25°C. Compared to HbA0, MG-treated HbA0 exhibited decreased absorbance around 280nm, reduced intrinsic fluorescence and lower surface hydrophobicity. MG treatment was not found to significantly affect the secondary structure of HbA0. The stability of MG-treated HbA0 was found to be higher compared to HbA0. Moreover, H2O2-mediated iron release and subsequent iron-mediated oxidation (Fenton) reactions were found to be lower in presence of MG-treated HbA0 compared to HbA0. As shown by mass spectrometric studies, MG modified Arg-92α, Arg-104β, Arg-31α and Arg-40β of HbA0 to hydroimidazolone adducts. The modifications thus appear to be associated with the observed structural alterations of the heme protein. Considering the increased level of MG in diabetes mellitus as well as its high reactivity, AGEs might be associated with structural and functional modifications of the protein including physiological significance.

  9. Plasmon-Enhanced Enzymatic Reactions 2:Optimization of Enzyme Activity by Surface Modification of Silver Island Films with Biotin-Poly (Ethylene-glycol)-Amine.

    PubMed

    Abel, Biebele; Aslan, Kadir

    2012-01-01

    Surface modification of silver island films (SIFs) was carried out with Biotin-Poly (Ethylene-glycol)-Amine (BEA), which acts as a cross-linker between the silver surface and horse radish peroxidase (HRP) enzyme for optimum plasmon-enhanced enzymatic activity. SIFs-deposited blank glass slides and SIFs-deposited 3-Aminopropyltriethoxysilane(APTES)-coated glass slides were used as our plasmonic surfaces.In this regard, three different extent of loading of SIFs were also prepared (low, medium and high) on APTES-coated glass slides. Streptavidin-linked HRP enzyme was attached to SIFs-deposited blank glass slides and SIFs-deposited APTES-coated glass slides through the well-known biotin-streptavidin interactions. The characterization of these surfaces was done using optical absorption spectroscopy. The loading of SIFs on glass slides was observed to have significant effect on the efficiency of plasmon-enhanced enzymatic activity, where an enhancement of 200% in the enzymatic activity was observed when compared to our previously used strategies for enzyme immobilization in our preceding work[1]. In addition, SIFs-deposited on APTES-coated glass slides were found to be re-usable for plasmon-enhanced enzymatic reactions unlike SIFs deposited on to blank glass slides.

  10. Dietary fucoidan of Acaudina molpadioides and its enzymatically degraded fragments could prevent intestinal mucositis induced by chemotherapy in mice.

    PubMed

    Zuo, Tao; Li, Xuemin; Chang, Yaoguang; Duan, Gaofei; Yu, Long; Zheng, Rong; Xue, Changhu; Tang, Qingjuan

    2015-02-01

    Mucositis is a common problem that results from cancer chemotherapy and is a cause of significant morbidity and occasional mortality. Its prevention and successful treatment can significantly enhance the quality of life of patients and improve their survival. Sea cucumber is a traditional aquatic food that has both nutritional and medicinal value. The polysaccharide fucoidan from the sea cucumber (SC-FUC) has various bioactivities. We examined the protective effect of different molecular weights (MWs 50 kDa-500 kDa) of fucoidan from the sea cucumber, Acaudina molpadioides, in a mouse model of cyclophosphamide (Cy)-induced intestinal mucositis. Results showed that the oral administration of SC-FUC markedly reversed Cy-induced damage in the mice. The sea cucumber fucoidan notably increased the ratio of the length of the intestinal villus to the crypt depth and ameliorated the IFN-γ/IL-4 ratio that signifies Th1/Th2 immune balance. Moreover, all the fucoidans in this study enhanced the expression of IgA by accelerating the expression of IL-6 that is probably combined with IL-10. The differing effects of the varied molecular weights of fucoidan may be due to the difference in the efficiency of absorption. This is a novel study on the potential preventive effects of SC-FUC on intestinal mucositis that may be related to the efficiency of its absorption during digestion. Sea cucumber fucoidan (SC-FUC) may be used as a potential food supplement to prevent chemotherapeutic mucositis.

  11. Mucositis and non-invasive markers of small intestinal function.

    PubMed

    Tooley, Katie L; Howarth, Gordon S; Butler, Ross N

    2009-05-01

    Mucositis is a common and debilitating side effect of chemotherapy that manifests due to the inability of chemotherapy agents to discriminate between normal and neoplastic cells. This results in ulcerating lesions lining the gastrointestinal tract. Moreover, the development of efficacious treatments for small intestinal mucositis has been hindered as the pathobiology of mucositis is still not fully understood. The small intestine is an extensive organ which is largely inaccessible by conventional means. Non-invasive biomarkers such as small intestinal permeability, H(2) breath tests, serum citrulline tests and the (13)C-sucrose breath test (SBT) have emerged as potential markers of small intestinal function. The SBT is emerging as the more appropriate biomarker to assess chemotherapy-induced mucositis in cancer patients and animal models, where it measures the decrease in sucrase activity associated with villus blunting and crypt disruption. The SBT has been successfully applied to detect mucositis induced by different classes of chemotherapy agents and has been used successfully to monitor small intestinal function with a range of candidate anti-mucositis treatments. We propose the SBT a superior biomarker of small intestinal function that could be successfully applied in clinical practice for monitoring the development of mucositis in cancer patients undergoing chemotherapy.

  12. Mucosal adenosine stimulates chloride secretion in canine tracheal epithelium

    SciTech Connect

    Pratt, A.D.; Clancy, G.; Welsh, M.J.

    1986-08-01

    Adenosine is a local regulator of a variety of physiological functions in many tissues and has been observed to stimulate secretion in several Cl-secreting epithelia. In canine tracheal epithelium the authors found that adenosine stimulates Cl secretion from both the mucosal and submucosal surfaces. Addition of adenosine, or its analogue 2-chloroadenosine, to the mucosal surface potently stimulated Cl secretion with no effect on the rate of Na absorption. Stimulation resulted from an interaction of adenosine with adenosine receptors, because it was blocked by the adenosine receptor blocker, 8-phenyltheophylline. The adenosine receptor was a stimulatory receptor as judged by the rank-order potency of adenosine and its analogues and by the increase in cellular adenosine 3',5'-cyclic monophosphate levels produced by 2-chloroadenosine. Adenosine also stimulated Cl secretion when it was added to the submucosal surface, although the maximal increase in secretion was less and it was much less potent. The observation that mucosal 8-phenyletheophylline blocked the effect of submucosal 2-chloroadenosine, whereas submucosal 8-phenyltheophylline did not prevent a response to mucosal or submucosal 2-chloroadenosine, suggests that adenosine receptors are located on the mucosal surface. Thus submucosal adenosine may stimulate secretion by crossing the epithelium and interacting with receptors located on the mucosal surface. Because adenosine can be released from mast cells located in the airway lumen in response to inhaled material, and because adenosine stimulated secretion from the mucosal surface, it may be in a unique position to control the epithelium on a regional level.

  13. The mucosal immune system: From dentistry to vaccine development.

    PubMed

    Kiyono, Hiroshi; Azegami, Tatsuhiko

    2015-01-01

    The oral cavity is the beginning of the aero-digestive tract, which is covered by mucosal epithelium continuously under the threat of invasion of pathogens, it is thus protected by the mucosal immune system. In the early phase of our scientific efforts for the demonstration of mucosal immune system, dental science was one of major driving forces due to their foreseeability to use oral immunity for the control of oral diseases. The mucosal immune system is divided functionally into, but interconnected inductive and effector sites. Intestinal Peyer's patches (PPs) are an inductive site containing antigen-sampling M cells and immunocompetent cells required to initiate antigen-specific immune responses. At effector sites, PP-originated antigen-specific IgA B cells become plasma cells to produce polymeric IgA and form secretory IgA by binding to poly-Ig receptor expressed on epithelial cells for protective immunity. The development of new-generation mucosal vaccines, including the rice-based oral vaccine MucoRice, on the basis of the coordinated mucosal immune system is a promising strategy for the control of mucosal infectious diseases.

  14. The mucosal immune system: From dentistry to vaccine development

    PubMed Central

    KIYONO, Hiroshi; AZEGAMI, Tatsuhiko

    2015-01-01

    The oral cavity is the beginning of the aero-digestive tract, which is covered by mucosal epithelium continuously under the threat of invasion of pathogens, it is thus protected by the mucosal immune system. In the early phase of our scientific efforts for the demonstration of mucosal immune system, dental science was one of major driving forces due to their foreseeability to use oral immunity for the control of oral diseases. The mucosal immune system is divided functionally into, but interconnected inductive and effector sites. Intestinal Peyer’s patches (PPs) are an inductive site containing antigen-sampling M cells and immunocompetent cells required to initiate antigen-specific immune responses. At effector sites, PP-originated antigen-specific IgA B cells become plasma cells to produce polymeric IgA and form secretory IgA by binding to poly-Ig receptor expressed on epithelial cells for protective immunity. The development of new-generation mucosal vaccines, including the rice-based oral vaccine MucoRice, on the basis of the coordinated mucosal immune system is a promising strategy for the control of mucosal infectious diseases. PMID:26460320

  15. Oral Mucosal Lesions in Indians From Northeast Brazil

    PubMed Central

    Cury, Patricia Ramos; Porto, Lia Pontes Arruda; dos Santos, Jean Nunes; e Ribeiro, Livia Silva Figueiredo; de Aquino Xavier, Flavia Caló; Figueiredo, Andreia Leal; Ramalho, Luciana Maria Pedreira

    2014-01-01

    Abstract The aim of this cross-sectional study was to evaluate the prevalence of oral mucosal lesions, and their risk indicators in adult Kiriri Indians from Northeast Brazil. Clinical oral examination was performed on a representative sample of 223 Indians (age ≥19 years). A systematic evaluation of lips, labial mucosa and sulcus, commissures, buccal mucosa and sulcus, gingiva and alveolar ridge, tongue, floor of the mouth, and soft and hard palate was performed. Bivariate analysis was conducted to assess associations between mucosal conditions and age, gender, income, educational level, diabetic status, and smoking status. Mucosal lesions were found in 50 participants (22.4%). The most prevalent lesions were fistulae (6.2%) and traumatic ulcers (4.48%). Oral mucosal was associated with higher age (≥35 years; odds ratio [OR] = 1.99, 95% confidence interval [CI]: 1.05–3.76, P = 0.03) and lower education level (<9 years; OR = 2.13, 95% CI: 0.96–4.71, P = 0.06). Mucosal conditions are prevalent in Kiriri Indians and the presence of mucosal lesions is associated with advanced age and lower education. A public health program aimed at preventing and treating mucosal lesions and targeted toward the high-risk group is vital to improve the oral health status of this population. PMID:25501053

  16. Granulomatous reaction to liquid injectable silicone for gluteal enhancement: review of management options and success of doxycycline.

    PubMed

    Paul, Suchismita; Goyal, Amrita; Duncan, Lyn M; Smith, Gideon P

    2015-01-01

    Liquid injectable silicone (LIS) for cosmetic purposes has been widely available and commonly used for almost half a century. An increase in buttock augmentation procedures because of patients wanting to emulate the look of some celebrities has recently highlighted cases in the media of unsafe administration of liquid silicone injections. Severe complications including death have been reported. In this article, we report a case in which liquid silicone was injected in the patient's gluteal tissue resulting in granulomatous reactions in the surrounding tissues. The patient responded well to doxycycline, presumably because of both its antimicrobial properties and immunomodulatory effects.

  17. Observation of low-lying resonances in the quasicontinuum of 195,196Pt and enhanced astrophysical reaction rates

    DOE PAGES

    Giacoppo, F.; Bello Garrote, F. L.; Eriksen, T. K.; ...

    2015-05-28

    An excess of strength on the low-energy tail of the giant dipole resonance recently has been observed in the γ-decay from the quasicontinuum of 195,196Pt. The nature of this phenomenon is not yet fully investigated. If this feature is present also in the γ-ray strength of the neutron-rich isotopes, it can affect the neutron-capture reactions involved in the formation of heavy-elements in stellar nucleosynthesis. The experimental level density and γ-ray strength function of 195,196Pt are presented together with preliminary calculations of the corresponding neutron-capture cross sections.

  18. Enhanced photoelectrochemical detection of bioaffinity reactions by vertically oriented au nanobranches complexed with a biotinylated polythiophene derivative.

    PubMed

    Zhou, Huiqiong; Tang, Yanli; Zhai, Jin; Wang, Shu; Tang, Zhiyong; Jiang, Lei

    2009-01-01

    Four nanostructured Au electrodes were prepared by a simple and templateless electrochemical deposition technique. After complexing with a biotinylated polythiophene derivative (PTBL), photocurrent generation and performance of PTBL/Au-nanostructured electrodes as photoelectrochemical biosensors were investigated. Among these four nanostructured Au electrodes, vertically oriented nanobranches on the electrode significantly improved the photoelectric conversion, because the vertically oriented nanostructures not only benefit light harvesting but also the transfer of the photogenerated charge carriers. Owing to this advantaged nanostructure, the PTBL/Au-nanobranch electrode showed higher sensitivity and faster response times in the photoelectrochemical detection of a streptavidin-biotin affinity reaction compared to a PTBL/Au-nanoparticle electrode.

  19. Adjuvant effect of Japanese herbal medicines on the mucosal type 1 immune responses to human papillomavirus (HPV) E7 in mice immunized orally with Lactobacillus-based therapeutic HPV vaccine in a synergistic manner.

    PubMed

    Taguchi, Ayumi; Kawana, Kei; Yokoyama, Terufumi; Adachi, Katsuyuki; Yamashita, Aki; Tomio, Kensuke; Kojima, Satoko; Oda, Katsutoshi; Fujii, Tomoyuki; Kozuma, Shiro

    2012-08-03

    The Japanese herbal medicines, Juzen-taiho-to (JTT) and Hochu-ekki-to (HET), have been shown to enhance humoral immune responses to vaccine antigen when used as adjuvants for prophylactic vaccines. However, their adjuvant effect on mucosal cellular immune responses remains unstudied. The precursor lesion of cervical cancer, high-grade CIN that expresses HPV E7 oncoprotein ubiquitously is a target for HPV therapeutic vaccines that elicit mucosal E7-specific type 1 T cell responses. We have demonstrated that oral immunization with recombinant Lactobacillus casei expressing HPV16 E7 (LacE7) is more effective in eliciting mucosal E7-specific IFNγ-producing cells than subcutaneous or intramuscular antigen delivery. Here we report the synergistic effect of an oral Lactobacillus-based vaccine and Japanese herbal medicines on mucosal immune responses. Oral immunization of mice with LacE7 plus either a Japanese herbal medicine (JTT or HET) or a mucosal adjuvant, heated-labile enterotoxin T subunit (LTB), promotes systemic E7-specific type 1 T cell responses but not mucosal responses. Administration of LacE7 plus either Japanese herbal medicine and LTB enhanced mucosal E7-specific type 1 T cell response to levels approximately 3-fold higher than those after administration of LacE7 alone. Furthermore, secretion of IFNγ and IL-2 into the intestinal lumen was observed after oral administration of LacE7 and was enhanced considerably by the addition of Japanese herbal medicines and LTB. Our data indicated that Japanese herbal medicines, in synergy with Lactobacillus and LTB, enhance the mucosal type 1 immune responses to orally immunized antigen. Japanese herbal medicines may be excellent adjuvants for oral Lactobacillus-based vaccines and oral immunization of LacE7, HET and LTB may have the potential to elicit extremely high E7-specific mucosal cytotoxic immune response to HPV-associated neoplastic lesions.

  20. Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations

    SciTech Connect

    Sato, T.; Ramirez-Cuesta, Anibal J.; Daemen, Luke L.; Cheng, Yong -Qiang; Tomiyasu, Keisuke; Takagi, Shigeyuki; Orimo, Shin-ichi

    2016-08-31

    Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4] was investigated using inelastic neutron scattering viewed from vibrational dynamics. Here, the hydrogen release followed the softening of translational and [AlH4] librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

  1. Enhancement of Colorimetric Response of Enzymatic Reactions by Thermally Evaporated Plasmonic Thin Films: Application to Glial Fibrillary Acidic Protein.

    PubMed

    Abel, Biebele; Kabir, Tabassum S; Odukoya, Babatunde; Mohammed, Muzaffer; Aslan, Kadir

    2015-02-07

    We report the enhancement of the colorimetric response of horseradish peroxidase (HRP) and alkaline phosphatase (AP) in bioassays by thermally evaporated silver, gold, copper and nickel thin films. In this regard, a model bioassay based on biotin-avidin interactions was employed. Biotin groups and enzymes were introduced to all surfaces using a biotinylated linker molecule and avidin, respectively. The colorimetric response of HRP in the model bioassay carried out on the plasmonic thin films were up to 4.4-fold larger as compared to control samples (i.e., no plasmonic thin films), where the largest enhancement of colorimetric response was observed on silver thin films. The colorimetric response of AP on plasmonic thin films was found to be similar to those observed on control samples, which was attributed to the loss of enzymes from the surface during the bioassay steps. The extent of enzymes immobilized on to plasmonic thin films was found to affect the colorimetric response of the model bioassay. These findings allowed us to demonstrate the use of silver thin films for the detection of glial fibrillary acidic protein (GFAP), where the colorimetric response of the standard bioassays for GFAP was enhanced up to 67% as compared to bioassays on glass slides.

  2. Enhancement of Colorimetric Response of Enzymatic Reactions by Thermally Evaporated Plasmonic Thin Films: Application to Glial Fibrillary Acidic Protein

    PubMed Central

    Abel, Biebele; Kabir, Tabassum S.; Odukoya, Babatunde; Mohammed, Muzaffer; Aslan, Kadir

    2015-01-01

    We report the enhancement of the colorimetric response of horseradish peroxidase (HRP) and alkaline phosphatase (AP) in bioassays by thermally evaporated silver, gold, copper and nickel thin films. In this regard, a model bioassay based on biotin-avidin interactions was employed. Biotin groups and enzymes were introduced to all surfaces using a biotinylated linker molecule and avidin, respectively. The colorimetric response of HRP in the model bioassay carried out on the plasmonic thin films were up to 4.4-fold larger as compared to control samples (i.e., no plasmonic thin films), where the largest enhancement of colorimetric response was observed on silver thin films. The colorimetric response of AP on plasmonic thin films was found to be similar to those observed on control samples, which was attributed to the loss of enzymes from the surface during the bioassay steps. The extent of enzymes immobilized on to plasmonic thin films was found to affect the colorimetric response of the model bioassay. These findings allowed us to demonstrate the use of silver thin films for the detection of glial fibrillary acidic protein (GFAP), where the colorimetric response of the standard bioassays for GFAP was enhanced up to 67% as compared to bioassays on glass slides. PMID:25663850

  3. Chemical characteristics and enhanced hepatoprotective activities of Maillard reaction products derived from milk protein-sugar system.

    PubMed

    Oh, Nam Su; Young Lee, Ji; Lee, Hyun Ah; Joung, Jae Yeon; Shin, Yong Kook; Kim, Sae Hun; Kim, Younghoon; Lee, Kwang Won

    2016-02-01

    The objective of this study was to investigate the characteristics, antioxidative properties, and hepatoprotective effects of Maillard reaction products (MRP) from milk protein reacted with sugars. The MRP were obtained from milk protein, whey protein concentrates and sodium caseinate, using 2 types of sugars, lactose and glucose, by heating the mixture at 55°C for 7d in a sodium phosphate buffer (pH 7.4). Changes in the chemical modification of the milk protein were monitored by measuring the protein-bound carbonyls and PAGE protein profiles. The results showed that the amount of protein-bound carbonyls increased after Maillard reaction (MR). In addition, sodium dodecyl sulfate-PAGE analysis indicated a formation of high-molecular weight complexes through MR. The modification sites induced by MR of milk protein were monitored by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of tryptic-digested gel spots of MRP. As a result, modification and their localization in AA sequence of MRP was identified. Also, the MRP showed higher antioxidant activities than the intact milk protein, and they reduced intracellular reactive oxygen species production and inhibited the depletion of the reduced glutathione concentrations in the HepG2 cells. In particular, glucose-sodium caseinate MRP showed the highest biological activities among all MRP. Therefore, these results suggest that the MRP from milk protein reacting with sugars possess effective antioxidant activity and have a protective ability against oxidative damage.

  4. Bismuth as a modifier of Au Pd catalyst: Enhancing selectivity in alcohol oxidation by suppressing parallel reaction

    SciTech Connect

    Villa, Alberto; Wang, Di; Veith, Gabriel M; Prati, Laura

    2012-01-01

    Bi has been widely employed as a modifier for Pd and Pt based catalyst mainly in order to improve selectivity. We found that when Bi was added to the bimetallic system AuPd, the effect on activity in alcohol oxidation mainly depends on the amount of Bi regardless its position, being negligible when Bi was 0.1 wt% and detectably negative when the amount was increased to 3 wt%. However, the selectivity of the reactions notably varied only when Bi was deposited on the surface of metal nanoparticles suppressing parallel reaction in both benzyl alcohol and glycerol oxidation. After a careful characterization of all the catalysts and additional catalytic tests, we concluded that the Bi influence on the activity of the catalysts could be ascribed to electronic effect whereas the one on selectivity mainly to a geometric modification. Moreover, the Bi-modified AuPd/AC catalyst showed possible application in the production of tartronic acid, a useful intermediate, from glycerol.

  5. Enhancement of thermal shock resistance of reaction sintered mullite–zirconia composites in the presence of lanthanum oxide

    SciTech Connect

    Kumar, P.; Nath, M.; Ghosh, A.; Tripathi, H.S.

    2015-03-15

    Mullite–zirconia composites containing 20 wt.% zirconia were prepared by reaction sintering of zircon flour, sillimanite beach sand and calcined alumina. 0 to 8 mol% of La{sub 2}O{sub 3} with respect to zirconia was used as sintering aid. The effect of additive on the various physical, microstructures, mechanical and thermo-mechanical properties was studied. Quantitative phase analysis shows the change in tetragonal zirconia content with incorporation of lanthanum oxide. La{sub 2}O{sub 3} addition has significantly improved the thermal shock resistance of the samples. Samples without additive retained only 20% of initial flexural strength after 5 cycles, whereas samples containing 5 mol% La{sub 2}O{sub 3} retained almost 78% of its initial flexural strength even after 15 thermal shock cycles. - Highlights: • Mullite–zirconia composites were prepared by reaction sintering route utilizing zircon and sillimanite beach sand. • Lanthanum oxide was used as sintering aid. • The presence of lanthanum oxide decreased the densification temperature. • Lanthanum oxide significantly improved the thermal shock resistance of the composites.

  6. Measurement of large spiral and target waves in chemical reaction-diffusion-advection systems: turbulent diffusion enhances pattern formation.

    PubMed

    von Kameke, A; Huhn, F; Muñuzuri, A P; Pérez-Muñuzuri, V

    2013-02-22

    In the absence of advection, reaction-diffusion systems are able to organize into spatiotemporal patterns, in particular spiral and target waves. Whenever advection is present that can be parametrized in terms of effective or turbulent diffusion D(*), these patterns should be attainable on a much greater, boosted length scale. However, so far, experimental evidence of these boosted patterns in a turbulent flow was lacking. Here, we report the first experimental observation of boosted target and spiral patterns in an excitable chemical reaction in a quasi-two-dimensional turbulent flow. The wave patterns observed are ~50 times larger than in the case of molecular diffusion only. We vary the turbulent diffusion coefficient D(*) of the flow and find that the fundamental Fisher-Kolmogorov-Petrovsky-Piskunov equation, v(f) proportional sqrt[D(*)], for the asymptotic speed of a reactive wave remains valid. However, not all measures of the boosted wave scale with D(*) as expected from molecular diffusion, since the wave fronts turn out to be highly filamentous.

  7. Enhanced photo-H2 production of R. faecalis RLD-53 by separation of CO2 from reaction system.

    PubMed

    Liu, Bing-Feng; Ren, Nan-Qi; Ding, Jie; Xie, Guo-Jun; Cao, Guang-Li

    2009-02-01

    The effect of different gases, CO(2) concentration, and separation of CO(2) from reaction system on photo-fermentation H(2) production was investigated by batch culture in this study. Experimental results showed that different gases (Ar,N(2),CO(2), and air) as gas phase have obviously affected on photo-H(2) production and a high concentration of CO(2) can inhibit the growth and H(2) evolution of Rhodopseudomonas faecalis RLD-53. When CO(2) concentration at 5%, cell increased most rapidly the specific growth rate of 0.489 g/l/h and the specific growth rate fell to be 0.265 g/l/h when CO(2) concentration at 40%. However, the growth of RLD-53 at CO(2) concentration of 60-100% was almost completely inhibited. At CO(2) concentrations of 5% and 10%, the maximum H(2) yield was 2.54 and 2.59 mol-H(2)/mol acetate, respectively, and it was similar with the control (2.61 mol-H(2)/mol acetate). H(2) not produced when CO(2) concentration at 60-100%. In conclusion, separation of CO(2) from reaction system can stimulate H(2) production in the entire photo-H(2) production process and H(2) yield increased about 12.8-18.85% than the control.

  8. Nod2-mediated recognition of the microbiota is critical for mucosal adjuvant activity of cholera toxin

    PubMed Central

    Kim, Donghyun; Kim, Yun-Gi; Seo, Sang-Uk; Kim, Dong-Jae; Kamada, Nobuhiko; Prescott, Dave; Philpott, Dana J.; Rosenstiel, Philip; Inohara, Naohiro; Núñez, Gabriel

    2016-01-01

    Cholera toxin (CT) is a potent adjuvant for inducing mucosal immune responses. However, the mechanism by which CT induces adjuvant activity remains unclear. Here we show that the microbiota is critical for inducing antigen-specific IgG production after intranasal immunization. After mucosal vaccination with CT, both antibiotic-treated mice and germ-free (GF) had reduced antigen-specific IgG, recall-stimulated cytokine responses, an impaired follicular helper T (TFH) response and reduced plasma cells. Recognition of symbiotic bacteria via Nod2 in CD11c+ cells was required for the adjuvanticity of CT. Reconstitution of GF mice with a Nod2 agonist or Staphylococcus sciuri having high Nod2-stimulatory activity was sufficient to promote robust CT adjuvant activity whereas bacteria with low Nod2-stimulatory activity did not. Mechanistically, CT enhanced Nod2-mediated cytokine production in DCs via intracellular cAMP. These results show an important role for the microbiota and the intracellular receptor Nod2 in promoting the mucosal adjuvant activity of CT. PMID:27064448

  9. A role for IL-22 in the relationship between intestinal helminths, gut microbiota and mucosal immunity.

    PubMed

    Leung, Jacqueline M; Loke, P'ng

    2013-03-01

    The intestinal tract is home to nematodes as well as commensal bacteria (microbiota), which have coevolved with the mammalian host. The mucosal immune system must balance between an appropriate response to dangerous pathogens and an inappropriate response to commensal microbiota that may breach the epithelial barrier, in order to maintain intestinal homeostasis. IL-22 has been shown to play a critical role in maintaining barrier homeostasis against intestinal pathogens and commensal bacteria. Here we review the advances in our understanding of the role of IL-22 in helminth infections, as well as in response to commensal and pathogenic bacteria of the intestinal tract. We then consider the relationship between intestinal helminths and gut microbiota and hypothesize that this relationship may explain how helminths may improve symptoms of inflammatory bowel diseases. We propose that by inducing an immune response that includes IL-22, intestinal helminths may enhance the mucosal barrier function of the intestinal epithelium. This may restore the mucosal microbiota populations from dysbiosis associated with colitis and improve intestinal homeostasis.

  10. Oral administration of a recombinant cholera toxin B subunit promotes mucosal healing in the colon.

    PubMed

    Baldauf, K J; Royal, J M; Kouokam, J C; Haribabu, B; Jala, V R; Yaddanapudi, K; Hamorsky, K T; Dryden, G W; Matoba, N

    2016-11-02

    Cholera toxin B subunit (CTB) is a component of a licensed oral cholera vaccine. However, CTB has pleiotropic immunomodulatory effects whose impacts on the gut are not fully understood. Here, we found that oral administration in mice of a plant-made recombinant CTB (CTBp) significantly increased several immune cell populations in the colon lamina propria. Global gene expression analysis revealed that CTBp had more pronounced impacts on the colon than the small intestine, with significant activation of TGFβ-mediated pathways in the colon epithelium. The clinical relevance of CTBp-induced impacts on colonic mucosa was examined. In a human colon epithelial model using Caco2 cells, CTBp, but not the non-GM1-binding mutant G33D-CTBp, induced TGFβ-mediated wound healing. In a dextran sodium sulfate (DSS) acute colitis mouse model, oral administration of CTBp protected against colon mucosal damage as manifested by mitigated body weight loss, decreased histopathological scores, and blunted escalation of inflammatory cytokine levels while inducing wound healing-related genes. Furthermore, biweekly oral administration of CTBp significantly reduced disease severity and tumorigenesis in the azoxymethane/DSS model of ulcerative colitis and colon cancer. Altogether, these results demonstrate CTBp's ability to enhance mucosal healing in the colon, highlighting its potential application in ulcerative colitis therapy besides cholera vaccination.Mucosal Immunology advance online publication 2 November 2016. doi:10.1038/mi.2016.95.

  11. Quantitative evaluation of mucosal vascular contrast in narrow band imaging using Monte Carlo modeling

    NASA Astrophysics Data System (ADS)

    Le, Du; Wang, Quanzeng; Ramella-Roman, Jessica; Pfefer, Joshua

    2012-06-01

    Narrow-band imaging (NBI) is a spectrally-selective reflectance imaging technique for enhanced visualization of superficial vasculature. Prior clinical studies have indicated NBI's potential for detection of vasculature abnormalities associated with gastrointestinal mucosal neoplasia. While the basic mechanisms behind the increased vessel contrast - hemoglobin absorption and tissue scattering - are known, a quantitative understanding of the effect of tissue and device parameters has not been achieved. In this investigation, we developed and implemented a numerical model of light propagation that simulates NBI reflectance distributions. This was accomplished by incorporating mucosal tissue layers and vessel-like structures in a voxel-based Monte Carlo algorithm. Epithelial and mucosal layers as well as blood vessels were defined using wavelength-specific optical properties. The model was implemented to calculate reflectance distributions and vessel contrast values as a function of vessel depth (0.05 to 0.50 mm) and diameter (0.01 to 0.10 mm). These relationships were determined for NBI wavelengths of 410 nm and 540 nm, as well as broadband illumination common to standard endoscopic imaging. The effects of illumination bandwidth on vessel contrast were also simulated. Our results provide a quantitative analysis of the effect of absorption and scattering on vessel contrast. Additional insights and potential approaches for improving NBI system contrast are discussed.

  12. Lactic acid bacteria--20 years exploring their potential as live vectors for mucosal vaccination.

    PubMed

    Wyszyńska, Agnieszka; Kobierecka, Patrycja; Bardowski, Jacek; Jagusztyn-Krynicka, Elżbieta Katarzyna

    2015-04-01

    Lactic acid bacteria (LAB) are a diverse group of Gram-positive, nonsporulating, low G + C content bacteria. Many of them have been given generally regarded as safe status. Over the past two decades, intensive genetic and molecular research carried out on LAB, mainly Lactococcus lactis and some species of the Lactobacillus genus, has revealed new, potential biomedical LAB applications, including the use of LAB as adjuvants, immunostimulators, or therapeutic drug delivery systems, or as factories to produce therapeutic molecules. LAB enable immunization via the mucosal route, which increases effectiveness against pathogens that use the mucosa as the major route of entry into the human body. In this review, we concentrate on the encouraging application of Lactococcus and Lactobacillus genera for the development of live mucosal vaccines. First, we present the progress that has recently been made in the field of developing tools for LAB genetic manipulations, which has resulted in the successful expression of many bacterial, parasitic, and viral antigens in LAB strains. Next, we discuss the factors influencing the efficacy of the constructed vaccine prototypes that have been tested in various animal models. Apart from the research focused on an application of live LABs as carriers of foreign antigens, a lot of work has been recently done on the potential usage of nonliving, nonrecombinant L. lactis designated as Gram-positive enhancer matrix (GEM), as a delivery system for mucosal vaccination. The advantages and disadvantages of both strategies are also presented.

  13. Effect of BML-111 on the intestinal mucosal barrier in sepsis and its mechanism of action.

    PubMed

    Liu, Huaizheng; Liu, Zuoliang; Zhao, Shangping; Sun, Chuanzheng; Yang, Mingshi

    2015-08-01

    5(S),6(R)-7-trihydroxymethyl heptanoate (BML-111) is an lipoxin A4 receptor agonist, which modulates the immune response and attenuates hemorrhagic shock-induced acute lung injury. However, the role of BML-111 in sepsis and in the intestinal mucosal barrier are not well understood. Therefore, the present study was designed to investigate the effect of BML-111 on the intestinal mucosal barrier in a rat model of sepsis. Furthermore, the molecular mechanism of action of BML-111 was evaluated. The cecal ligation and puncture-induced rat model of sepsis was constructed, and BML-111 was administered at three different doses. The results revealed that BML-111 suppressed the elevation of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6, while enhancing the elevation of the anti-inflammatory cytokine transforming growth factor-β in the intestine. In addition, BML-111 significantly upregulated rat defensin-5 mRNA expression levels and downregulated the induction of cell apoptosis as well as caspase-3 activity in the intestine. All these results demonstrated that BML-111 exerted protective effects on the intestinal mucosal barrier in sepsis. Further, it was indicated that alterations in the expression of toll-like receptor (TLR)2 and TLR4 may be one of the molecular mechanisms underlying the protective effect of BML-111. The present study therefore suggested that BML-111 may be a novel therapeutic agent for sepsis.

  14. Enhancement of Compound Selectivity Using a Radio Frequency Ion-Funnel Proton Transfer Reaction Mass Spectrometer: Improved Specificity for Explosive Compounds.

    PubMed

    González-Méndez, Ramón; Watts, Peter; Olivenza-León, David; Reich, D Fraser; Mullock, Stephen J; Corlett, Clive A; Cairns, Stuart; Hickey, Peter; Brookes, Matthew; Mayhew, Chris A

    2016-11-01

    A key issue with any analytical system based on mass spectrometry with no initial separation of compounds is to have a high level of confidence in chemical assignment. This is particularly true for areas of security, such as airports, and recent terrorist attacks have highlighted the need for reliable analytical instrumentation. Proton transfer reaction mass spectrometry is a useful technology for these purposes because the chances of false positives are small owing to the use of a mass spectrometric analysis. However, the detection of an ion at a given m/z for an explosive does not guarantee that that explosive is present. There is still some ambiguity associated with any chemical assignment owing to the presence of isobaric compounds and, depending on mass resolution, ions with the same nominal m/z. In this article we describe how for the first time the use of a radio frequency ion-funnel (RFIF) in the reaction region (drift tube) of a proton transfer reaction-time-of-flight-mass spectrometer (PTR-ToF-MS) can be used to enhance specificity by manipulating the ion-molecule chemistry through collisional induced processes. Results for trinitrotoluene, dinitrotoluenes, and nitrotoluenes are presented to demonstrate the advantages of this new RFIF-PTR-ToF-MS for analytical chemical purposes.

  15. Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

    NASA Astrophysics Data System (ADS)

    Ahmed, Nesreen S.; Menzel, Robert; Wang, Yifan; Garcia-Gallastegui, Ainara; Bawaked, Salem M.; Obaid, Abdullah Y.; Basahel, Sulaiman N.; Mokhtar, Mohamed

    2017-02-01

    Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

  16. Diazotization-coupling reaction-based selective determination of nitrite in complex samples using shell-isolated nanoparticle-enhanced Raman spectroscopy.

    PubMed

    Zhang, Kaige; Hu, Yuling; Li, Gongke

    2013-11-15

    A simple, rapid and selective method based on diazotization-coupling reaction for determination of nitrite ion in complex samples using shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) was developed. Based on diazotization-coupling reaction, nitrite was transformed into azo dye, which has strong SHINERS activity. Subsequently the concentration of nitrite ion can be determined indirectly from the SHINERS of azo dye. The SHINERS active substrate was composed of gold nanoparticle as core with an ultrathin silica shell having pinhole on the surface. Various factors that influence reaction and SHINERS intensity were investigated. Under the optimal conditions, the linearity was observed in the range of 0.5-6.0 mg L(-1) with good correlation coefficient (r(2)>0.9793). The relative standard deviations (RSDs) for five replicate measurements were less than 14.5%. The limit of detections of the method (S/N=3) were 0.07, 0.08 and 0.10 mg L(-1) at 1137, 1395 and 1432 cm(-1), respectively, without sample preconcentration. The selectivity of the proposed method was also tested. The performance of SHINERS to determine the concentration of nitrite in food, biological and environmental samples was evaluated. The results indicate that SHINERS shows great potential as a useful analytical tool for trace analysis of nitrite in real samples. This proposed method provides a practical protocol for determination of compounds with weak Raman response, and can be expanded for the indirect detection of iodate ion, phenols and aromatic amines.

  17. Protective effect of histamine microinjected into cerebellar fastigial nucleus on stress gastric mucosal damage in rats.

    PubMed

    Qiao, Xiao; Yang, Jun; Fei, Su-Juan; Zhu, Jin-Zhou; Zhu, Sheng-Ping; Liu, Zhang-Bo; Li, Ting-Ting; Zhang, Jian-Fu

    2015-12-10

    In the study, we investigated the effect of histamine microinjected into cerebellar fastigial nucleus (FN) on stress gastric mucosal damage (SGMD), and its mechanisms in rats. The model of SGMD was established by restraining and water (21±1°C)-immersion for 3h. The gastric mucosal damage index (GMDI) indicated the severity of gastric mucosal damage. Histamine or receptor antagonist was microinjected into the FN. The decussation of superior cerebellar peduncle (DSCP) and the lateral hypothalamic area (LHA) were destroyed, respectively. The pathological changes of gastric mucosa were evaluated using biological signal acquisition system, Laser-Doppler flowmeter, and western blotting. We found that the microinjection of histamine (0.05, 0.5, and 5μg) into FN significantly attenuated the SGMD, in a dose-dependent manner, whereas, the microinjection of histamine H2 receptor antagonist, ranitidine, and glutamic acid decarboxylase antagonist, 3-mercaptopropionic acid (3-MPA) exacerbated the SGMD. The protective effect of histamine on SGMD was abolished by electrical lesion of DSCP or chemical ablation of LHA. The microinjection of histamine decreased the discharge frequency of the greater splanchnic nerve, and the gastric mucosal blood flow was increased. In addition, the cellular proliferation was enhanced, but the cellular apoptosis was reduced in the gastric mucosa. Also the pro-apoptosis protein, Bax, and caspase-3 were down-regulated, and the anti-apoptosis protein, Bcl-2 was up-regulated following microinjection of histamine. In conclusion, the FN participated in the regulation of SGMD after histamine microinjected into FN, and cerebellar-hypothalamic circuits (include: DSCP, LHA) contribute to the process, which may provide a new therapeutic strategy for SGMD.

  18. Synthetic Antenna Functioning As Light Harvester in the Whole Visible Region for Enhanced Hybrid Photosynthetic Reaction Centers.

    PubMed

    Hassan Omar, Omar; la Gatta, Simona; Tangorra, Rocco Roberto; Milano, Francesco; Ragni, Roberta; Operamolla, Alessandra; Argazzi, Roberto; Chiorboli, Claudio; Agostiano, Angela; Trotta, Massimo; Farinola, Gianluca M

    2016-07-20

    The photosynthetic reaction center (RC) from the Rhodobacter sphaeroides bacterium has been covalently bioconjugated with a NIR-emitting fluorophore (AE800) whose synthesis was specifically tailored to act as artificial antenna harvesting light in the entire visible region. AE800 has a broad absorption spectrum with peaks centered in the absorption gaps of the RC and its emission overlaps the most intense RC absorption bands, ensuring a consistent increase of the protein optical cross section. The covalent hybrid AE800-RC is stable and fully functional. The energy collected by the artificial antenna is transferred to the protein via FRET mechanism, and the hybrid system outperforms by a noteworthy 30% the overall photochemical activity of the native protein under the entire range of visible light. This improvement in the optical characteristic of the photoenzyme demonstrates the effectiveness of the bioconjugation approach as a suitable route to new biohybrid materials for energy conversion, photocatalysis, and biosensing.

  19. Observation of enhanced rate coefficients in the H2 + + H 2 → H3 + + H reaction at low collision energies

    NASA Astrophysics Data System (ADS)

    Allmendinger, Pitt; Deiglmayr, Johannes; Höveler, Katharina; Schullian, Otto; Merkt, Frédéric

    2016-12-01

    The energy dependence of the rate coefficient of the H2 + + H 2 → H3 + + H reaction has been measured in the range of collision energies between k B ṡ 10 K and k B ṡ 300 mK . A clear deviation of the rate coefficient from the value expected on the basis of the classical Langevin-capture behavior has been observed at collision energies below k B ṡ 1 K , which is attributed to the joint effects of the ion-quadrupole and Coriolis interactions in collisions involving ortho-H2 molecules in the j = 1 rotational level, which make up 75% of the population of the neutral H2 molecules in the experiments. The experimental results are compared to very recent predictions by Dashevskaya et al. [J. Chem. Phys. 145, 244315 (2016)], with which they are in agreement.

  20. Highly uniform distribution of Pt nanoparticles on N-doped hollow carbon spheres with enhanced durability for oxygen reduction reaction

    SciTech Connect

    Shi, Qiurong; Zhu, Chengzhou; Engelhard, Mark H.; Du, Dan; Lin, Yuehe

    2017-01-01

    Carbon-supported Pt nanostructures currently exhibited great potential in polymer electrolyte membrane fuel cells. Nitrogen-doped hollow carbon spheres (NHCSs) with extra low density and high specific surface area are promising carbon support for loading Pt NPs. The doped heteroatom of nitrogen could not only contribute to the active activity for the oxygen reduction reaction (ORR), but also shows a strong interaction with Pt NPs for entrapping them from dissolution/migration. This synergetic effect/interaction resulted in the uniform dispersion and strong combination of the Pt NPs on the carbon support and thus play a significant role in hindering the degradation of the catalytic activities of Pt NPs. As expected, the as-obtained Pt/NHCSs displayed improved catalytic activity and superior durability toward ORR.

  1. Ultradispersed Cobalt Ferrite Nanoparticles Assembled in Graphene Aerogel for Continuous Photo-Fenton Reaction and Enhanced Lithium Storage Performance

    NASA Astrophysics Data System (ADS)

    Qiu, Bocheng; Deng, Yuanxin; Du, Mengmeng; Xing, Mingyang; Zhang, Jinlong

    2016-07-01

    The Photo-Fenton reaction is an advanced technology to eliminate organic pollutants in environmental chemistry. Moreover, the conversion rate of Fe3+/Fe2+ and utilization rate of H2O2 are significant factors in Photo-Fenton reaction. In this work, we reported three dimensional (3D) hierarchical cobalt ferrite/graphene aerogels (CoFe2O4/GAs) composites by the in situ growing CoFe2O4 crystal seeds on the graphene oxide (GO) followed by the hydrothermal process. The resulting CoFe2O4/GAs composites demonstrated 3D hierarchical pore structure with mesopores (14~18 nm), macropores (50~125 nm), and a remarkable surface area (177.8 m2 g‑1). These properties endowed this hybrid with the high and recyclable Photo-Fenton activity for methyl orange pollutant degradation. More importantly, the CoFe2O4/GAs composites can keep high Photo-Fenton activity in a wide pH. Besides, the CoFe2O4/GAs composites also exhibited excellent cyclic performance and good rate capability. The 3D framework can not only effectively prevent the volume expansion and aggregation of CoFe2O4 nanoparticles during the charge/discharge processes for Lithium-ion batteries (LIBs), but also shorten lithium ions and electron diffusion length in 3D pathways. These results indicated a broaden application prospect of 3D-graphene based hybrids in wastewater treatment and energy storage.

  2. Ultradispersed Cobalt Ferrite Nanoparticles Assembled in Graphene Aerogel for Continuous Photo-Fenton Reaction and Enhanced Lithium Storage Performance

    PubMed Central

    Qiu, Bocheng; Deng, Yuanxin; Du, Mengmeng; Xing, Mingyang; Zhang, Jinlong

    2016-01-01

    The Photo-Fenton reaction is an advanced technology to eliminate organic pollutants in environmental chemistry. Moreover, the conversion rate of Fe3+/Fe2+ and utilization rate of H2O2 are significant factors in Photo-Fenton reaction. In this work, we reported three dimensional (3D) hierarchical cobalt ferrite/graphene aerogels (CoFe2O4/GAs) composites by the in situ growing CoFe2O4 crystal seeds on the graphene oxide (GO) followed by the hydrothermal process. The resulting CoFe2O4/GAs composites demonstrated 3D hierarchical pore structure with mesopores (14~18 nm), macropores (50~125 nm), and a remarkable surface area (177.8 m2 g−1). These properties endowed this hybrid with the high and recyclable Photo-Fenton activity for methyl orange pollutant degradation. More importantly, the CoFe2O4/GAs composites can keep high Photo-Fenton activity in a wide pH. Besides, the CoFe2O4/GAs composites also exhibited excellent cyclic performance and good rate capability. The 3D framework can not only effectively prevent the volume expansion and aggregation of CoFe2O4 nanoparticles during the charge/discharge processes for Lithium-ion batteries (LIBs), but also shorten lithium ions and electron diffusion length in 3D pathways. These results indicated a broaden application prospect of 3D-graphene based hybrids in wastewater treatment and energy storage. PMID:27373343

  3. Site-specific growth of Au-Pd alloy horns on Au nanorods: a platform for highly sensitive monitoring of catalytic reactions by surface enhancement Raman spectroscopy.

    PubMed

    Huang, Jianfeng; Zhu, Yihan; Lin, Ming; Wang, Qingxiao; Zhao, Lan; Yang, Yang; Yao, Ke Xin; Han, Yu

    2013-06-12

    Surface-enhanced Raman scattering (SERS) is a highly sensitive probe for molecular detection. The aim of this study was to develop an efficient platform for investigating the kinetics of catalytic reactions with SERS. To achieve this, we synthesized a novel Au-Pd bimetallic nanostructure (HIF-AuNR@AuPd) through site-specific epitaxial growth of Au-Pd alloy horns as catalytic sites at the ends of Au nanorods. Using high-resolution electron microscopy and tomography, we successfully reconstructed the complex three-dimensional morphology of HIF-AuNR@AuPd and identified that the horns are bound with high-index {11l} (0.25 < l < 0.43) facets. With an electron beam probe, we visualized the distribution of surface plasmon over the HIF-AuNR@AuPd nanorods, finding that strong longitudinal surface plasmon resonance concentrated at the rod ends. This unique crystal morphology led to the coupling of high catalytic activity with a strong SERS effect at the rod ends, making HIF-AuNR@AuPd an excellent bifunctional platform for in situ monitoring of surface catalytic reactions. Using the hydrogenation of 4-nitrothiophenol as a model reaction, we demonstrated that its first-order reaction kinetics could be accurately determined from this platform. Moreover, we clearly identified the superior catalytic activity of the rod ends relative to that of the rod bodies, owing to the different SERS activities at the two positions. In comparison with other reported Au-Pd bimetallic nanostructures, HIF-AuNR@AuPd offered both higher catalytic activity and greater detection sensitivity.

  4. Gastrointestinal mucositis: the role of MMP-tight junction interactions in tissue injury.

    PubMed

    Al-Dasooqi, Noor; Wardill, Hannah R; Gibson, Rachel J

    2014-07-01

    Chemotherapy for cancer causes significant gut toxicity known as mucositis. The pathogenesis of mucositis is ill defined. Recent clinical research guidelines have highlighted epithelial junctional complexes as emerging targets within mucositis research. Given the robust biological evidence linking tight junctions and matrix metalloproteinases, key mediators of mucositis, tight junction proteins have received significant attention. Despite this, the link between tight junctions, matrix metalloproteinases and mucositis development is yet to be established. This critical review therefore aims to describe the role of matrix metalloproteinases in mucositis, and how matrix metalloproteinase-dependent tight junction disruption may contribute to the pathobiology of mucositis.

  5. Accelerated on-column lysine derivatization and cysteine methylation by imidazole reaction in a deuterated environment for enhanced product ion analysis.

    PubMed

    Cindrić, Mario; Cepo, Tina; Skrlin, Ana; Vuletić, Marko; Bindila, Laura

    2006-01-01

    -column reaction could be obtained when using D2O, as compared to water-based reaction. Methylation of cysteine residues was enhanced when beta-mercaptoethanol was added in the reactant solution.

  6. Physiology and immunology of mucosal barriers in catfish (Ictalurus spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mucosal barriers of catfish (Ictalurus spp.) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient adsorption, osmoregulation, waste excretion, and environmental sensing. Catf...

  7. Gene, environment, microbiome and mucosal immune tolerance in rheumatoid arthritis

    PubMed Central

    Deane, Kevin D.; Scher, Jose U.

    2016-01-01

    RA is a complex multifactorial chronic disease that transitions through several stages. Multiple studies now support that there is a prolonged phase in early RA development during which there is serum elevation of RA-related autoantibodies including RF and ACPAs in the absence of clinically evident synovitis. This suggests that RA pathogenesis might originate in an extra-articular location, which we hypothesize is a mucosal site. In discussing this hypothesis, we will present herein the current understanding of mucosal immunology, including a discussion about the generation of autoimmune responses at these surfaces. We will also examine how other factors such as genes, microbes and other environmental toxins (including tobacco smoke) could influence the triggering of autoimmunity at mucosal sites and eventually systemic organ disease. We will also propose a research agenda to improve our understanding of the role of mucosal inflammation in the development of RA. PMID:25539828

  8. Prevention of acute gastric mucosal lesions by Solcoseryl.

    PubMed

    Brzozowski, T; Radecki, T; Sendur, R; Gustaw, P; Konturek, S J

    1987-04-01

    Solcoseryl, a deproteinized extract from calf blood containing various biologically active substances, has been reported to promote the healing of skin wounds and gastric ulceration In this study, the gastroprotective effects of Solcoseryl vis-a-vis acute gastric mucosal damage were examined in rats. Solcoseryl significantly reduced the formation of acute lesions induced by intragastric application of absolute ethanol or acidified taurocholate and by water immersion and restraint stress, but failed to affect those caused by acidified aspirin. Since Solcoseryl did not offer protection in the absence of mucosal prostaglandins (PG) e.g. in aspirin-induced gastric damage, it is likely that PG may be involved in the observed gastroprotective activity of the drug. Solcoseryl failed to affect gastric acid or pepsin secretion, but increased mucosal blood flow. Thus PG generated by Solcoseryl might contribute to the maintenance of the observed mucosal microcirculation and the prevention of lesion formation by corrosive substances and stress conditions.

  9. A Chemical-Adsorption Strategy to Enhance the Reaction Kinetics of Lithium-Rich Layered Cathodes via Double-Shell Surface Modification.

    PubMed

    Guo, Lichao; Li, Jiajun; Cao, Tingting; Wang, Huayu; Zhao, Naiqin; He, Fang; Shi, Chunsheng; He, Chunnian; Liu, Enzuo

    2016-09-21

    Sluggish surface reaction kinetics hinders the power density of Li-ion battery. Thus, various surface modification techniques have been applied to enhance the electronic/ionic transfer kinetics. However, it is challenging to obtain a continuous and uniform surface modification layer on the prime particles with structure integration at the interface. Instead of classic physical-adsorption/deposition techniques, we propose a novel chemical-adsorption strategy to synthesize double-shell modified lithium-rich layered cathodes with enhanced mass transfer kinetics. On the basis of experimental measurement and first-principles calculation, MoO2S2 ions are proved to joint the layered phase via chemical bonding. Specifically, the Mo-O or Mo-S bonds can flexibly rotate to bond with the cations in the layered phase, leading to the good compatibility between the thiomolybdate adsorption layer and layered cathode. Followed by annealing treatment, the lithium-excess-spinel inner shell forms under the thiomolybdate adsorption layer and functions as favorable pathways for lithium and electron. Meanwhile, the nanothick MoO3-x(SO4)x outer shell protects the transition metal from dissolution and restrains electrolyte decomposition. The double-shell modified sample delivers an enhanced discharge capacity almost twice as much as that of the unmodified one at 1 A g(-1) after 100 cycles, demonstrating the superiority of the surface modification based on chemical adsorption.

  10. Bifunctional enhancement of oxygen reduction reaction activity on Ag catalysts due to water activation on LaMnO3 supports in alkaline media

    PubMed Central

    Park, Shin-Ae; Lee, Eun-Kyung; Song, Hannah; Kim, Yong-Tae

    2015-01-01

    Ag is considered to be one of the best candidates for oxygen reduction reaction electrocatalysts in alkaline media for application in various electrochemical energy devices. In this study, we demonstrate that water activation is a key factor in enhancing the ORR activity in alkaline media, unlike in acid environments. Ag supported on LaMnO3 having a high oxophilicity showed a markedly higher ORR activity than that on carbon with inert surfaces. Through various electrochemical tests, it was revealed that the origin of the enhanced ORR activity of Ag/LaMnO3 is the bifunctional effect mainly due to the water activation at the interface between Ag and LaMnO3. Furthermore, the ligand effect due to the charge transfer from Mn to Ag leads to the enhancement of both oxygen activation on Ag and water activation on Mn sites, and hence, an improvement in the ORR activity of Ag/LaMnO3. On the other hand, the strain effect based on the fine structure variation in the lattice was negligible. We therefore suggest that the employment of a co-catalyst or support with highly oxophilic nature and the maximization of the interface between catalyst and support should be considered in the design of electrocatalysts for the ORR in alkaline media. PMID:26310526

  11. Optimization of reaction conditions to fabricate nano-silver using Couroupita guianensis Aubl. (leaf & fruit) and its enhanced larvicidal effect

    NASA Astrophysics Data System (ADS)

    Vimala, R. T. V.; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal

    2015-01-01

    Currently bioactive principles of plants and their nanoproducts have been extensively studied in agriculture and medicine. In this study Couroupita guianensis Aubl. leaf and fruit extracts were selected for rapid and cost-effective synthesis of silver nanoparticles (leaf-LAgNPs and fruit-FAgNPs). Various physiological conditions such as temperature, pH, concentration of metal ions, stoichiometric proportion of reaction mixture and reaction time showed influence on the size, dispersity and synthesis rate of AgNPs. Generation of AgNPs was initially confirmed with the surface plasmon vibrations at 420 nm in UV-visible spectrophotometer. The results recorded from X-ray diffractometer (XRD) and Transmission electron microscope (TEM) supports the biosynthesis of cubic crystalline LAgNPs & FAgNPs with the size ranges between 10-45 nm and 5-15 nm respectively. Surface chemistry of synthesized AgNPs was studied with Fourier transform infrared spectroscopy (FTIR), it reveals that water soluble phenolic compounds present in the extracts act as reducing and stabilizing agent. Leaf, fruit extracts and synthesized AgNPs were evaluated against IV instar larvae of Aedes aegypti (Diptera; Culicidae). Furthermore, different extracts and synthesized AgNPs showed dose dependent larvicidal effect against A. aegypti after 24 h of treatment. Compare to all extracts such as ethyl acetate (leaf; LC50 - 44.55 ppm and LC90 - 318.39 ppm & fruit; LC50 - 49.96 ppm and LC90 - 568.84 ppm respectively) and Methanol (leaf; LC50 - 85.75 ppm and LC90 - 598.63 ppm & fruit; LC50 - 67.78 ppm and LC90 - 714.45 ppm respectively) synthesized AgNPs showed extensive mortality rate (LAgNPs; LC50 - 2.1 ppm and LC90 - 5.59 ppm & FAgNPs; LC50 - 2.09 ppm and LC90 - 5.7 ppm). Hence, this study proves that C. guianensis is a potential bioresource for stable, reproducible nanoparticle synthesis (AgNPs) and also can be used as an efficient mosquito control agent.

  12. Optimization of reaction conditions to fabricate nano-silver using Couroupita guianensis Aubl. (leaf & fruit) and its enhanced larvicidal effect.

    PubMed

    Vimala, R T V; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal

    2015-01-25

    Currently bioactive principles of plants and their nanoproducts have been extensively studied in agriculture and medicine. In this study Couroupita guianensis Aubl. leaf and fruit extracts were selected for rapid and cost-effective synthesis of silver nanoparticles (leaf-LAgNPs and fruit-FAgNPs). Various physiological conditions such as temperature, pH, concentration of metal ions, stoichiometric proportion of reaction mixture and reaction time showed influence on the size, dispersity and synthesis rate of AgNPs. Generation of AgNPs was initially confirmed with the surface plasmon vibrations at 420 nm in UV-visible spectrophotometer. The results recorded from X-ray diffractometer (XRD) and Transmission electron microscope (TEM) supports the biosynthesis of cubic crystalline LAgNPs & FAgNPs with the size ranges between 10-45 nm and 5-15 nm respectively. Surface chemistry of synthesized AgNPs was studied with Fourier transform infrared spectroscopy (FTIR), it reveals that water soluble phenolic compounds present in the extracts act as reducing and stabilizing agent. Leaf, fruit extracts and synthesized AgNPs were evaluated against IV instar larvae of Aedes aegypti (Diptera; Culicidae). Furthermore, different extracts and synthesized AgNPs showed dose dependent larvicidal effect against A. aegypti after 24h of treatment. Compare to all extracts such as ethyl acetate (leaf; LC50 - 44.55 ppm and LC90 - 318.39 ppm & fruit; LC50 - 49.96 ppm and LC90 - 568.84 ppm respectively) and Methanol (leaf; LC50 - 85.75 ppm and LC90 - 598.63 ppm & fruit; LC50 - 67.78 ppm and LC90 - 714.45 ppm respectively) synthesized AgNPs showed extensive mortality rate (LAgNPs; LC50 - 2.1 ppm and LC90 - 5.59 ppm & FAgNPs; LC50 - 2.09 ppm and LC90 - 5.7 ppm). Hence, this study proves that C. guianensis is a potential bioresource for stable, reproducible nanoparticle synthesis (AgNPs) and also can be used as an efficient mosquito control agent.

  13. Dominating Role of Ni(0) on the Interface of Ni/NiO for Enhanced Hydrogen Evolution Reaction.

    PubMed

    Wang, Jing; Mao, Shanjun; Liu, Zeyan; Wei, Zhongzhe; Wang, Haiyan; Chen, Yiqing; Wang, Yong

    2017-03-01

    The research of a robust catalytic system based on single NiOx electrocatalyst for hydrogen evolution reaction (HER) remains a huge challenge. Particularly, the factors that dominate the catalytic properties of NiOx-based hybrids for HER have not been clearly demonstrated. Herein, a convenient protocol for the fabrication of NiOx@bamboo-like carbon nanotube hybrids (NiOx@BCNTs) is designed. The hybrids exhibit superb catalytic ability and considerable durability in alkaline solution. A benchmark HER current density of 10 mA cm(-2) has been achieved at an overpotential of ∼79 mV. In combination with the experimental results and density functional theory (DFT) calculations, this for the first time definitely validates that the inherent high Ni(0) ratio and the Ni(0) on the interface of Ni/NiO play a vital role in the outstanding catalytic performance. Especially, the Ni(0) on the interface of Ni/NiO performs superior activity for water splitting compared with that of bulk Ni(0). These conclusions provide guidance for the rational design of the future non-noble metallic catalysts.

  14. Synergistic effect of Nitrogen-doped hierarchical porous carbon/graphene with enhanced catalytic performance for oxygen reduction reaction

    NASA Astrophysics Data System (ADS)

    Kong, Dewang; Yuan, Wenjing; Li, Cun; Song, Jiming; Xie, Anjian; Shen, Yuhua

    2017-01-01

    Developing efficient and economical catalysts for the oxygen reduction reaction (ORR) is important to promote the commercialization of fuel cells. Here, we report a simple and environmentally friendly method to prepare nitrogen (N) -doped hierarchical porous carbon (HPC)/reduced graphene oxide (RGO) composites by reusing waste biomass (pomelo peel) coupled with graphene oxide (GO). This method is green, low-cost and without using any acid or alkali activator. The typical sample (N-HPC/RGO-1) contains 5.96 at.% nitrogen and larger BET surface area (1194 m2/g). Electrochemical measurements show that N-HPC/RGO-1 exhibits not only a relatively positive onset potential and high current density, but also considerable methanol tolerance and long-term durability in alkaline media as well as in acidic media. The electron transfer number is close to 4, which means that it is mostly via a four-electron pathway toward ORR. The excellent catalytic performance of N-HPC/RGO-1 is due to the synergistic effect of the inherent interwoven network structure of HPC, the good electrical conductivity of RGO, and the heteroatom doping for the composite. More importantly, this work demonstrates a good example for turning discarded rubbish into valuable functional products and addresses the disposal issue of waste biomass simultaneously for environment clean.

  15. Overwhelming reaction enhanced by ultrasonics during brazing of alumina to copper in air by Zn-14Al hypereutectic filler.

    PubMed

    Ji, Hongjun; Chen, Hao; Li, Mingyu

    2017-03-01

    The ultrasonic-assisted brazing of α-alumina to copper was achieved in air without flux using Zn-14wt%Al hypereutectic filler at 753K within tens of seconds. The effects of ultrasonic time on the microstructures and mechanical properties of joints were investigated. In the joint interlayer, large amounts of intermetallic phases consisted of binary CuZn5 embedded by many ternary Al4.2Cu3.2Zn0.7 particles were formed. At the ceramic interface, newly formed crystalline Al2O3 aggregated. At the Cu interface, acoustic corrosion on the copper resulted in depriving the surface oxides and forming many pits on its surface, which provided saturated Cu in the melted filler alloys during the brazing. The ultrasonic vibrations had distinct effects on the metallurgical reactions of the joints, resulting in intermetallic-phase-filled composite joints with shear strength of 66MPa. The overgrowth of intermetallic compounds, the newly formed crystalline alumina, and the acoustic pits was probably ascribed to the ultrasonic effects.

  16. Microstructural Healing with Interfacial Reaction Layers on the Adhesive Strength Enhancement of Plasma-Sprayed Hydroxyapatite Coatings

    NASA Astrophysics Data System (ADS)

    Yang, Chung-Wei; Lui, Truan-Sheng

    The effect of hydrothermal crystallization and adding reinforced intermediate layers on improving the tensile adhesion of plasma-sprayed HA coatings (HAC) was investigated. The experimental results show that the index of crystallinity (IOC) and phase purity of hydrothermally-treated HAC (HT-HAC) are increased by the low-temperature hydrothermal treatment. The microstructural healing effect with nano-size HA crystallites is significant to diminish the defects and prevent mechanical strength degradation for the HT-HAC. XPS analysis demonstrates that hydrothermal crystallization helps to promote the interfacial Ti-OH chemical reaction. HA composite coatings with CP-Ti and ZrO2 intermediate layers provide another strengthening effect compared with the hydrothermal-heating method. The inter-diffusion of Ca results in a chemical bonding at the HA/ZrO2 interface, which results in the increase of the adhesive strength of composite coatings. The fracture behavior is different between the crystallization-induced HAC and the composite coatings. The HT-HAC remains on the substrate with an evident cohesive failure. The adhesive failure occurred at HA/intermediate layers for composite coatings. Failures with less percentage area of interfacial fracture are indicative of a higher strength of a coating.

  17. Enhanced performance of PbS-sensitized solar cells via controlled successive ionic-layer adsorption and reaction.

    PubMed

    Abbas, Muhammad A; Basit, Muhammad A; Park, Tae Joo; Bang, Jin Ho

    2015-04-21

    Despite the potential of PbS quantum dots (QDs) as sensitizers for quantum-dot-sensitized solar cells (QDSSCs), achieving a high photocurrent density over 30 mA cm(-2) remains a challenging task in PbS-sensitized solar cells. In contrast to previous attempts, where Hg(2+)-doping or multi-step post-treatment is necessary, we are capable of achieving a high photocurrent exceeding 30 mA cm(-2) simply by manipulating the successive ionic layer adsorption and reaction (SILAR) method. We show that controlling temperature at which SILAR is performed is critical to obtain a higher and more uniform coverage of PbS QDs over a mesoporous TiO2 film. The deposition of a CdS inter-layer between TiO2 and PbS is found to be an effective means of ensuring high photocurrent and stability. Not only does this modification improve the light absorption capability of the photoanode, but it also has a significant effect on charge recombination and electron injection efficiency at the PbS/TiO2 interface according to our in-depth study using electrochemical impedance spectroscopy (EIS). The implication of subtle changes in the interfacial events via modified SILAR conditions for PbS-sensitized solar cells is discussed.

  18. Ab initio molecular dynamics with enhanced sampling for surface reaction kinetics at finite temperatures: CH2⇌ CH + H on Ni(111) as a case study.

    PubMed

    Sun, Geng; Jiang, Hong

    2015-12-21

    A comprehensive understanding of surface thermodynamics and kinetics based on first-principles approaches is crucial for rational design of novel heterogeneous catalysts, and requires combining accurate electronic structure theory and statistical mechanics modeling. In this work, ab initio molecular dynamics (AIMD) combined with the integrated tempering sampling (ITS) method has been explored to study thermodynamic and kinetic properties of elementary processes on surfaces, using a simple reaction CH2⇌CH+H on the Ni(111) surface as an example. By a careful comparison between the results from ITS-AIMD simulation and those evaluated in terms of the harmonic oscillator (HO) approximation, it is found that the reaction free energy and entropy from the HO approximation are qualitatively consistent with the results from ITS-AIMD simulation, but there are also quantitatively significant discrepancies. In particular, the HO model misses the entropy effects related to the existence of multiple adsorption configurations arising from the frustrated translation and rotation motion of adsorbed species, which are different in the reactant and product states. The rate constants are evaluated from two ITS-enhanced approaches, one using the transition state theory (TST) formulated in terms of the potential of mean force (PMF) and the other one combining ITS with the transition path sampling (TPS) technique, and are further compared to those based on harmonic TST. It is found that the rate constants from the PMF-based TST are significantly smaller than those from the harmonic TST, and that the results from PMF-TST and ITS-TPS are in a surprisingly good agreement. These findings indicate that the basic assumptions of transition state theory are valid in such elementary surface reactions, but the consideration of statistical averaging of all important adsorption configurations and reaction pathways, which are missing in the harmonic TST, are critical for accurate description of

  19. Cystic fibrosis: a mucosal immunodeficiency syndrome

    PubMed Central

    Cohen, Taylor Sitarik; Prince, Alice

    2013-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) functions as a channel that regulates the transport of ions and the movement of water across the epithelial barrier. Mutations in CFTR, which form the basis for the clinical manifestations of cystic fibrosis, affect the epithelial innate immune function in the lung, resulting in exaggerated and ineffective airway inflammation that fails to eradicate pulmonary pathogens. Compounding the effects of excessive neutrophil recruitment, the mutant CFTR channel does not transport antioxidants to counteract neutrophil-associated oxidative stress. Whereas mutant CFTR expression in leukocytes outside of the lung does not markedly impair their function, the expected regulation of inflammation in the airways is clearly deficient in cystic fibrosis. The resulting bacterial infections, which are caused by organisms that have substantial genetic and metabolic flexibility, can resist multiple classes of antibiotics and evade phagocytic clearance. The development of animal models that approximate the human pulmonary phenotypes—airway inflammation and spontaneous infection—may provide the much-needed tools to establish how CFTR regulates mucosal immunity and to test directly the effect of pharmacologic potentiation and correction of mutant CFTR function on bacterial clearance. PMID:22481418

  20. Mucosal immune responses following intestinal nematode infection

    PubMed Central

    Zaph, C; Cooper, P J; Harris, N L

    2014-01-01

    In most natural environments, the large majority of mammals harbour parasitic helminths that often live as adults within the intestine for prolonged periods (1–2 years) 1. Although these organisms have been eradicated to a large extent within westernized human populations, those living within rural areas of developing countries continue to suffer from high infection rates. Indeed, recent estimates indicate that approximately 2·5 billion people worldwide, mainly children, currently suffer from infection with intestinal helminths (also known as geohelminths and soil-transmitted helminths) 2. Paradoxically, the eradication of helminths is thought to contribute to the increased incidence of autoimmune diseases and allergy observed in developed countries. In this review, we will summarize our current understanding of host–helminth interactions at the mucosal surface that result in parasite expulsion or permit the establishment of chronic infections with luminal dwelling adult worms. We will also provide insight into the adaptive immune mechanisms that provide immune protection against re-infection with helminth larvae, a process that is likely to be key to the future development of successful vaccination strategies. Lastly, the contribution of helminths to immune modulation and particularly to the treatment of allergy and inflammatory bowel disease will be discussed. PMID:25201407

  1. Berberine Reduces Uremia-Associated Intestinal Mucosal Barrier Damage.

    PubMed

    Yu, Chao; Tan, Shanjun; Zhou, Chunyu; Zhu, Cuilin; Kang, Xin; Liu, Shuai; Zhao, Shuang; Fan, Shulin; Yu, Zhen; Peng, Ai; Wang, Zhen

    2016-11-01

    Berberine is one of the main active constituents of Rhizoma coptidis, a traditional Chinese medicine, and has long been used for the treatment of gastrointestinal disorders. The present study was designed to investigate the effects of berberine on the intestinal mucosal barrier damage in a rat uremia model induced by the 5/6 kidney resection. Beginning at postoperative week 4, the uremia rats were treated with daily 150 mg/kg berberine by oral gavage for 6 weeks. To assess the intestinal mucosal barrier changes, blood samples were collected for measuring the serum D-lactate level, and terminal ileum tissue samples were used for analyses of intestinal permeability, myeloperoxidase activity, histopathology, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity. Berberine treatment resulted in significant decreases in the serum D-lactate level, intestinal permeability, intestinal myeloperoxidase activity, and intestinal mucosal and submucosal edema and inflammation, and the Chiu's scores assessed for intestinal mucosal injury. The intestinal MDA level was reduced and the intestinal SOD activity was increased following berberine treatment. In conclusion, berberine reduces intestinal mucosal barrier damage induced by uremia, which is most likely due to its anti-oxidative activity. It may be developed as a potential treatment for preserving intestinal mucosal barrier function in patients with uremia.

  2. Sodium alginate inhibits methotrexate-induced gastrointestinal mucositis in rats.

    PubMed

    Yamamoto, Atsuki; Itoh, Tomokazu; Nasu, Reishi; Kajiwara, Eiji; Nishida, Ryuichi

    2013-01-01

    Gastrointestinal mucositis is one of the most prevalent side effects of chemotherapy. Methotrexate is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukemia and other malignancies. Through its effects on normal tissues with high rates of proliferation, methotrexate treatment leads to gastrointestinal mucositis. In rats, methotrexate-induced gastrointestinal mucositis is histologically characterized by crypt loss, callus fusion and atrophy, capillary dilatation, and infiltration of mixed inflammatory cells. The water-soluble dietary fiber sodium alginate (AL-Na) is derived from seaweed and has demonstrated muco-protective and hemostatic effects on upper gastrointestinal ulcers. In the present study, we evaluated the effects of AL-Na on methotrexate-induced small intestinal mucositis in rats. Animals were subcutaneously administered methotrexate at a dosage of 2.5 mg/kg once daily for 3 d. Rats were treated with single oral doses of AL-Na 30 min before and 6 h after methotrexate administration. On the 4th day, small intestines were removed and weighed. Subsequently, tissues were stained with hematoxylin-eosin and bromodeoxyuridine. AL-Na significantly prevented methotrexate-induced small intestinal mucositis. Moreover, AL-Na prevented decreases in red blood cell numbers, hemoglobin levels, and hematocrit levels. These results suggest the potential of AL-Na as a therapy for methotrexate-induced small intestinal mucositis.

  3. Nocifensive Behaviors in Mice with Radiation-Induced Oral Mucositis.

    PubMed

    Nolan, Michael W; Long, C Tyler; Marcus, Karen L; Sarmadi, Shayan; Roback, Donald M; Fukuyama, Tomoki; Baeumer, Wolfgang; Lascelles, B Duncan X

    2017-02-10

    Oral mucositis can result in significant dysphagia, and is the most common dose-limiting acute toxicity in head and neck cancer patients receiving chemoradiotherapy. There is a critical need to determine the cellular and molecular mechanisms that underlie radiotherapy-associated discomfort in patients with mucositis. The objective was to induce oral mucositis in mice, using a clinical linear accelerator, and to quantify resultant discomfort, and characterize peripheral sensitization. A clinical linear accelerator was used to deliver ionizing radiation to the oral cavity of mice. Mucositis severity scoring, and various behavioral assays were performed to quantify bouts of orofacial wiping and scratching, bite force, gnawing behavior and burrowing activity. Calcium imaging was performed on neurons of the trigeminal ganglia. Glossitis was induced with a single fraction of at least 27 Gy. Body weight decreased and subsequently returned to baseline, in concert with development and resolution of mucositis, which was worst at day 10 and 11 postirradiation, however was resolved within another 10 days. Neither bite force, nor gnawing behavior were measurably affected. However, burrowing activity was decreased, and both facial wiping and scratching were increased while mice had visible mucositis lesions. Sensory nerves of irradiated mice were more responsive to histamine, tumor necrosis factor alpha and capsaicin. Radiation-induced glossitis is associated with hyper-reactivity of sensory neurons in the trigeminal ganglia of mice, and is accompanied by several behaviors indicative of both itch and pain. These data validate an appropriate model for cancer treatment related discomfort in humans.

  4. [New routes of administration: epidermal, transcutaneous mucosal ways of vaccination].

    PubMed

    Denis, François; Alain, Sophie; Ploy, Marie-Cécile

    2007-04-01

    A successful vaccine triggers the interaction of various cells of the immune system as does a regular immune response. It is thus necessary to introduce the vaccine antigens into an anatomic site where they will contact immune cells. The route of administration is thus critical for the outcome of vaccination. Intramuscular or subcutaneous injections are the most popular. Antigens injected intramuscularly can form persistent precipitates that are dissolved and re-absorbed relatively slowly. If injecting antigens is a quick, easy and reproducible way to vaccination, it requires trained personnel. Alternatives exist, through non-invasive formulations which allow administration by the patient or a third party with no particular expertise. The skin, especially its epidermal layer, is an accessible and competent immune environment and an attractive target for vaccine delivery, through transcutaneous delivery or immunostimulant patches. Mucosal immunization is another strategy: its major rationale is that organisms invade the body via mucosal surfaces. Therefore, local protection at mucosal surface as well as systemic defense is beneficial. Various formulations of mucosal vaccines have been developed, such as the Sabin oral polio vaccine (OPV), rotavirus vaccines, cold-adapted influenza vaccines or vaccine against typhoid fever. Thus we are entering in an era where mucosal and transcutaneous immunisation will play an important role in disease management. However, it has not been so easy to obtain regulatory approval for mucosal or transcutaneous formulations and needle-based vaccines continue to dominate the market.

  5. Oral mucositis in children suffering from acute lymphoblastic leukaemia

    PubMed Central

    2012-01-01

    Aim of the study Oral mucositis is the most commonly reported side effect observed in neoplastic patients treated with chemotherapy and radiotherapy of the head and neck region as well as in patients who have received a haematopoietic stem cell transplant. The aim of the study was to assess the oral mucosa status in children with acute lymphoblastic leukaemia (ALL) during antineoplastic therapy. Material and methods The clinical examination included 78 children aged 2-18 with ALL. The clinical examination was conducted using the dental preset tray. The condition of the oral mucosa was determined using the WHO scale for oral mucositis. Results In the first period of antineoplastic therapy the pathological lesions of the oral mucosa of the mucositis type were observed among the examined patients. The lesions had various levels of intensity. Pain was found to be the primary symptom of oral mucositis. In this study the following were observed: local erythema of the oral mucosa in 35%, white pseudomembranous lesions in 18%, erosions in 40% and oral ulcerative lesions in 4% of patients who underwent the antineoplastic therapy. Oral mucositis was observed in 3.17% of children after 6 months of chemotherapy. Conclusion Local treatment of oral mucositis with polyantibiotic-antifungal mixture, supporting antifungal systemic treatment, and improving the overall peripheral blood conditions in children suffering from acute lymphoblastic leukaemia improve the condition of the oral mucosa. PMID:23788849

  6. Using Light to Treat Mucositis and Help Wounds Heal

    NASA Technical Reports Server (NTRS)

    Ignatius, Robert W.; Martin, Todd S.; Kirk, Charles

    2008-01-01

    A continuing program of research and development is focusing on the use of controlled illumination by light-emitting diodes (LEDs) to treat mucositis and to accelerate healing of wounds. The basic idea is to illuminate the affected area of a patient with light of an intensity, duration, and wavelength (or combination of wavelengths) chosen to produce a therapeutic effect while generating only a minimal amount of heat. This method of treatment was originally intended for treating the mucositis that is a common complication of chemotherapy and radiation therapy for cancer. It is now also under consideration as a means to accelerate the healing of wounds and possibly also to treat exposure to chemical and radioactive warfare agents. Radiation therapy and many chemotherapeutic drugs often damage the mucosal linings of the mouth and gastrointestinal tract, leading to mouth ulcers (oral mucositis), nausea, and diarrhea. Hyperbaric-oxygen therapy is currently the standard of care for ischemic, hypoxic, infected, and otherwise slowlyhealing problem wounds, including those of oral mucositis. Hyperbaric-oxygen therapy increases such cellular activities as collagen production and angiogenesis, leading to an increased rate of healing. Biostimulation by use of laser light has also been found to be effective in treating mucositis. For hyperbaricoxygen treatment, a patient must remain inside a hyperbaric chamber for an extended time. Laser treatment is limited by laser-wavelength capabilities and by narrowness of laser beams, and usually entails the generation of significant amounts of heat.

  7. Enhanced late gas generation potential of petroleum source rocks via recombination reactions: Evidence from the Norwegian North Sea

    NASA Astrophysics Data System (ADS)

    Erdmann, Michael; Horsfield, Brian

    2006-08-01

    Gas generation in the deep reaches of sedimentary basins is usually considered to take place via the primary cracking of short alkyl groups from overmature kerogen or the secondary cracking of petroleum. Here, we show that recombination reactions ultimately play the dominant role in controlling the timing of late gas generation in source rocks which contain mixtures of terrigeneous and marine organic matter. These reactions, taking place at low levels of maturation, result in the formation of a thermally stable bitumen, which is the major source of methane at very high maturities. The inferences come from pyrolysis experiments performed on samples of the Draupne Formation (liptinitic Type II kerogen) and Heather Formation (mixed marine-terrigeneous Type III kerogen), both Upper Jurassic source rocks stemming from the Norwegian northern North Sea Viking Graben system. Non-isothermal closed system micro scale sealed vessel (MSSV) pyrolysis, non-isothermal open system pyrolysis and Rock Eval type pyrolysis were performed on the solvent extracted, concentrated kerogens of the two immature samples. The decrease of C 6+ products in the closed system MSSV pyrolysis provided the basis for the calculation of secondary gas (C 1-5) formation. Subtraction of the calculated secondary gas from the total observed gas yields a "remaining" gas. In the case of the Draupne Formation this is equivalent to primary gas cracked directly from the kerogen, as detected by a comparison with multistep open pyrolysis data. For the Heather Formation the calculated remaining gas formation profile is initially attributable to primary gas but there is a second major gas pulse at very high temperature (>550 °C at 5.0 K min -1) that is not primary. This has been explained by a recondensation process where first formed high molecular weight compounds in the closed system yield a macromolecular material that undergoes secondary cracking at elevated temperatures. The experiments provided the input for

  8. Investigation on enhanced chemiluminescence reaction systems with bis(hydrogenperiodato) argentate(III) complex anion for fluoroquinolones synthetic antibiotics.

    PubMed

    Sun, Hanwen; Chen, Peiyun; Wang, Fei; Wen, Haifang

    2009-07-15

    A novel chemiluminescence (CL) reaction system with bis(hydrogenperiodato) argentate(III) complex anion (Ag(III) complex, [Ag(HIO(6))(2)](5-)), for the first time, is developed for the determination of lomefloxacin (LMFX), enrofloxacin (ENLX) and pefloxacin (PFLX). The possible CL emission mechanism was discussed by comparing the fluorescence emission with CL spectra. The CL conditions of [Ag(HIO(6))(2)](5-)-H(2)SO(4)-LMFX/ENLX/PFLX systems were investigated and optimized. Under the optimized experimental conditions, the CL intensity is proportional to the concentration of the drugs in the range 0.2994-36.80x10(-7)g mL(-1) for LMFX, 4.00-30.0x10(-7)g mL(-1) for ENLX and 1.54-27.64x10(-7)g mL(-1) for PFLX. The limit of detection (s/n=3) was 9.1x10(-9)g mL(-1) for LMFX, 3.1x10(-9)g mL(-1) for ENLX and 4.4x10(-9)g mL(-1) for PFLX. The recovery of LMFX, ENLX and PELX from the spiked pharmaceutical preparations was in the range of 92.3-105% with the RSDs of 0.5-2.7%. For urine, serum and milk samples the recoveries of the three drugs were in the range of 85.1-107% for LMFX with the RSDs of 2.3-3.4%. 80.2-112% for ENLX with the RSDs of 1.4-2.8%, and 87.8-114% for PFLX with the RSDs of 1.6-2.7%. The proposed method was applied successfully to the determination of these compounds in real samples.

  9. Overcoming RNA inhibition in the fluorescent polymerase chain reaction assay to enhance detection of bovine DNA in cattle feeds.

    PubMed

    Sawyer, Mary; Rensen, Gabriel; Smith, Wayne; Yee, Melanie; Wong, Alice; Osburn, Bennie; Cullor, James

    2004-01-01

    The practice of incorporating mammalian protein in ruminant feeds was banned in the United States in 1997 as a measure to avoid transmission of bovine spongiform encephalopathy (BSE). A sensitive means of identifying the banned additives in feeds would be by detection of species-specific DNA using the polymerase chain reaction (PCR). However, problems may arise in the PCR due to the presence of inhibitory substances. Using human DNA as an internal PCR control, inhibitory substances were evident in the DNA extraction products of cattle feeds. The results of heating experiments excluded enzymes as a cause of inhibition, and spectrophotometric calculations suggested the possibility of RNA contamination. Co-electrophoresis of untreated and RNAse digested extracts confirmed the presence of RNA in the undigested product. Seven cattle feeds were spiked with predetermined amounts of bovine meat and bone meal (BMBM). The DNA extracted products were treated with RNAse and the bovine specific mitochondrial DNA (B-mtDNA) was amplified by PCR. The minimum level of detection of B-mtDNA was influenced by RNAse treatment and feed composition. RNAse treatment decreased false-negative results overall by 75%. False-negative results were decreased 100% in the higher BMBM concentrations and 50% in the lower BMBM concentrations. Also, each cattle feed was spiked to attain a 2% wt/wt concentration with each swine, fish, sheep, or poultry product, or cattle dried blood. Amplification of B-mtDNA occurred only with the cattle dried blood and only in three feeds in which B-mtDNA was detected at the only level tested (2%). A commercial immunochromotographic assay (Neogen) detected the spiked BMBM in only one of the seven feeds and only at the upper concentration (1%).

  10. An investigation of the role of water on retrograde/condensation reactions and enhanced liquefaction yields. Final report

    SciTech Connect

    Miknis, F.P.; Netzel, D.A.; Wallace, J.C. Jr.; Butcher, C.H.; Mitzel, J.M.; Turner, T.F.

    1995-02-01

    While great strides have been made in developing the technology of coal liquefaction processes in recent years, many unsolved problems still remain before a viable and economical process can be achieved. The technological problems that still exist can be solved through a more fundamental understanding of the chemistry associated with each stage of the coal liquefaction process, starting with any pretreatment steps that may be carried out on the coal itself. Western Research Institute, under the a contract from the US Department of Energy, has conducted a study of different methods of coal drying as pretreatment steps before liquefaction. The results of that study are the subject of this report. Coals that were dried or partially dried thermally and with microwaves had lower liquefaction conversions than coals containing equilibrium moisture contents. However, chemically dried coals had conversions equal to or greater than the premoisturized coals. The conversion behavior is consistent with changes in the physical structure and cross linking reactions because of drying. Thermal and microwave drying appear to cause a collapse in the pore structure, thus preventing donor solvents such as tetralin from contacting reactive sites inside the coals. Chemical dehydration does not appear to collapse the pore structure. From the study of the kinetics of the chemical dehydration of coals, it was possible to quantify the amount of water on the surface, the amount readily accessible in pores, and the amount more strongly bonded in the internal structure of the coals. The results indicate that high-rank coals have proportionally less surface and easily accessible water than the lower rank coals.

  11. Methotrexate-induced mucositis in acute leukemia patients is not associated with the MTHFR 677T allele in Mexico.

    PubMed

    Ruiz-Argüelles, Guillermo J; Coconi-Linares, Lucia Nancy; Garcés-Eisele, Javier; Reyes-Núñez, Virginia

    2007-10-01

    Methylenetetrahydrofolate reductase (MTHFR) has two common variants with reduced activity due to polymorphisms at nucleotides 677 and 1298. Both affect folate metabolism and thus remethylation of homocysteine, but are also thought to affect nucleotide synthesis and DNA methylation. Methotrexate (MTX), which interrupts folate metabolism, is used in the treatment of a variety of diseases including acute lymphoblastic leukemia (ALL), but exerts in some patients toxic effects on fast dividing tissues such as mucosal epithelia. The enhanced toxicity may be due to cooperative effects between MTX and MTHFR variants. Accordingly, it has been reported that carrying the 677T allele of the MTHFR is a risk factor for MTX-associated mucositis. As in the Mexican population, which is characterized by a high prevalence of the 677T MTHFR variant, several of its commonly associated defects have not been observed, we investigated the relationship between MTX toxicity and the 677T allele. Out of 28 patients with ALL (CC: 2, CT: 10, TT: 16), 16 had episodes of MTX-associated mucositis (CC: 0, CT: 6, TT: 10). Neither at the gene level nor at the genotype level was a significant association with mucositis found. It may be postulated that the risk of higher MTX toxicity in patients with decreased MTHFR activity could be neutralized by the normally folate rich diet in Mexico.

  12. A novel non-toxic combined CTA1-DD and ISCOMS adjuvant vector for effective mucosal immunization against influenza virus.

    PubMed

    Eliasson, Dubravka Grdic; Helgeby, Anja; Schön, Karin; Nygren, Caroline; El-Bakkouri, Karim; Fiers, Walter; Saelens, Xavier; Lövgren, Karin Bengtsson; Nyström, Ida; Lycke, Nils Y

    2011-05-23

    Here we demonstrate that by using non-toxic fractions of saponin combined with CTA1-DD we can achieve a safe and above all highly efficacious mucosal adjuvant vector. We optimized the construction, tested the requirements for function and evaluated proof-of-concept in an influenza A virus challenge model. We demonstrated that the CTA1-3M2e-DD/ISCOMS vector provided 100% protection against mortality and greatly reduced morbidity in the mouse model. The immunogenicity of the vector was superior to other vaccine formulations using the ISCOM or CTA1-DD adjuvants alone. The versatility of the vector was best exemplified by the many options to insert, incorporate or admix vaccine antigens with the vector. Furthermore, the CTA1-3M2e-DD/ISCOMS could be kept 1 year at 4°C or as a freeze-dried powder without affecting immunogenicity or adjuvanticity of the vector. Strong serum IgG and mucosal IgA responses were elicited and CD4 T cell responses were greatly enhanced after intranasal administration of the combined vector. Together these findings hold promise for the combined vector as a mucosal vaccine against influenza virus infections including pandemic influenza. The CTA1-DD/ISCOMS technology represents a breakthrough in mucosal vaccine vector design which successfully combines immunomodulation and targeting in a safe and stable particulate formation.

  13. Effect of age and maternal antibodies on the systemic and mucosal immune response after neonatal immunization in a porcine model

    PubMed Central

    Guzman-Bautista, Edgar R; Garcia-Ruiz, Carlos E; Gama-Espinosa, Alicia L; Ramirez-Estudillo, Carmen; Rojas-Gomez, Oscar I; Vega-Lopez, Marco A

    2014-01-01

    Newborn mammals are highly susceptible to respiratory infections. Although maternal antibodies (MatAb) offer them some protection, they may also interfere with their systemic immune response to vaccination. However, the impact of MatAb on the neonatal mucosal immune response remains incompletely described. This study was performed to determine the effect of ovalbumin (OVA)-specific MatAb on the anti-OVA antibody response in sera, nasal secretions and saliva from specific pathogen-free Vietnamese miniature piglets immunized at 7 or 14 days of age. Our results demonstrated that MatAb increased antigen-specific IgA and IgG responses in sera, and transiently enhanced an early secretory IgA response in nasal secretions of piglets immunized at 7 days of age. In contrast, we detected a lower mucosal (nasal secretion and saliva) anti-OVA IgG response in piglets with MatAb immunized at 14 days of age, compared with piglets with no MatAb, suggesting a modulatory effect of antigen-specific maternal factors on the isotype transfer to the mucosal immune exclusion system. In our porcine model, we demonstrated that passive maternal immunity positively modulated the systemic and nasal immune responses of animals immunized early in life. Our results, therefore, open the possibility of inducing systemic and respiratory mucosal immunity in the presence of MatAb through early vaccination. PMID:24754050

  14. Acute Toxicity and Gastroprotective Role of M. pruriens in Ethanol-Induced Gastric Mucosal Injuries in Rats

    PubMed Central

    Hassandarvish, Pouya; Abdul Majid, Nazia; Hadi, A. Hamid A.; Nordin, Noraziah; Abdulla, Mahmood A.

    2013-01-01

    The investigation was to evaluate gastroprotective effects of ethanolic extract of M. pruriens leaves on ethanol-induced gastric mucosal injuries in rats. Forty-eight rats were divided into 8 groups: negative control, extract control, ulcer control, reference control, and four experimental groups. As a pretreatment, the negative control and the ulcer control groups were orally administered carboxymethylcellulose (CMC). The reference control was administered omeprazole orally (20 mg/kg). The ethanolic extract of M. pruriens leaves was given orally to the extract control group (500 mg/kg) and the experimental groups (62.5, 125, 250, and 500 mg/kg). After 1 h, CMC was given orally to the negative and the extract control groups. The other groups received absolute ethanol. The rats were sacrificed after 1 h. The ulcer control group exhibited significant mucosal injuries with decreased gastric wall mucus and severe damage to the gastric mucosa. The extract caused upregulation of Hsp70 protein, downregulation of Bax protein, and intense periodic acid schiff uptake of glandular portion of stomach. Gastric mucosal homogenate showed significant antioxidant properties with increase in synthesis of PGE2, while MDA was significantly decreased. The ethanolic extract of M. pruriens leaves was nontoxic (<5 g/kg) and could enhance defensive mechanisms against hemorrhagic mucosal lesions. PMID:23781513

  15. ZnWO{sub 4}–Cu system with enhanced photocatalytic activity by photo-Fenton-like synergistic reaction

    SciTech Connect

    Song, Jimei; Wang, Hong; Hu, Gang; Zhao, Shaojuan; Hu, Haiqin; Jin, Baokang

    2012-11-15

    Highlights: ► A novel coupled system of ZnWO{sub 4}–Cu exhibited much higher catalytic activity than pure ZnWO{sub 4} with H{sub 2}O{sub 2} under UV-light irradiation. ► The enhanced catalytic activity of ZnWO{sub 4}–Cu system was due to the synergistic effect of photocatalysis and Fenton-like process. ► The possible mechanism of the synergistic effect was proposed. -- Abstract: A novel coupled system of ZnWO{sub 4}–Cu, combining two different advanced oxidation processes of photocatalysis and Fenton-like for the degradation of organic dyes, was successfully synthesized. The as-synthesized samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS). The nanosized ZnWO{sub 4}–Cu samples exhibited much higher catalytic activity than pure ZnWO{sub 4}. In the presence of the ZC-0.2, the MB solution was completely degraded (the degradation ratio reached 97.79%); while for the ZC-0, the degradation ratio was only 72.29%. The effects of the amount of Cu on the photocatalytic performance of ZnWO{sub 4}–Cu were investigated in detail. The result showed that the synergistic effect between Cu and ZnWO{sub 4} played a key role. The possible mechanism of the synergistic system was proposed.

  16. A solid-state nuclear magnetic resonance study of post-plasma reactions in organosilicone microwave plasma-enhanced chemical vapor deposition (PECVD) coatings.

    PubMed

    Hall, Colin J; Ponnusamy, Thirunavukkarasu; Murphy, Peter J; Lindberg, Mats; Antzutkin, Oleg N; Griesser, Hans J

    2014-06-11

    Plasma-polymerized organosilicone coatings can be used to impart abrasion resistance and barrier properties to plastic substrates such as polycarbonate. Coating rates suitable for industrial-scale deposition, up to 100 nm/s, can be achieved through the use of microwave plasma-enhanced chemical vapor deposition (PECVD), with optimal process vapors such as tetramethyldisiloxane (TMDSO) and oxygen. However, it has been found that under certain deposition conditions, such coatings are subject to post-plasma changes; crazing or cracking can occur anytime from days to months after deposition. To understand the cause of the crazing and its dependence on processing plasma parameters, the effects of post-plasma reactions on the chemical bonding structure of coatings deposited with varying TMDSO-to-O2 ratios was studied with (29)Si and (13)C solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) using both single-pulse and cross-polarization techniques. The coatings showed complex chemical compositions significantly altered from the parent monomer. (29)Si MAS NMR spectra revealed four main groups of resonance lines, which correspond to four siloxane moieties (i.e., mono (M), di (D), tri (T), and quatern