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Sample records for microsphere induced gastrointestinal

  1. Cefoperazone Induced Gastrointestinal Bleeding.

    PubMed

    Katukuri, Goutham Reddy; Maddala, Raja Naga Mahesh; Ramamoorthi, Kusugodlu; Hande, Manjunatha

    2016-08-01

    Cefoperazone is a beta-lactam antibiotic which is frequently used in treating a variety of gram positive and gram negative infections. The chemical structure of cefoperazone contains a side chain of N-methylthiotetrazole which can inhibit vitamin K metabolism resulting in hypoprothombinemia. We report a case of cefoperazone induced coagulopathy manifesting as gastrointestinal bleeding. A Naranjo assessment score of 5 was obtained, indicating a probable relationship between the patient's coagulation function disorder and her use of the suspect drug. PMID:27656491

  2. Laser-Induced Spallation of Microsphere Monolayers.

    PubMed

    Hiraiwa, Morgan; Stossel, Melicent; Khanolkar, Amey; Wang, Junlan; Boechler, Nicholas

    2016-08-01

    The detachment of a semiordered monolayer of polystyrene microspheres adhered to an aluminum-coated glass substrate is studied using a laser-induced spallation technique. The microsphere-substrate adhesion force is estimated from substrate surface displacement measurements obtained using optical interferometry, and a rigid-body model that accounts for the inertia of the microspheres. The estimated adhesion force is compared with estimates obtained using an adhesive contact model together with interferometric measurements of the out-of-plane microsphere contact resonance, and with estimated work of adhesion values for the polystyrene-aluminum interface. Scanning electron microscope images of detached monolayer regions reveal a unique morphology, namely, partially detached monolayer flakes composed of single hexagonal close packed crystalline domains. This work contributes to the fields of microsphere adhesion and contact dynamics, and demonstrates a unique monolayer delamination morphology. PMID:27409715

  3. In vitro and in vivo evaluation of mucoadhesive microspheres prepared for the gastrointestinal tract using polyglycerol esters of fatty acids and a poly(acrylic acid) derivative.

    PubMed

    Akiyama, Y; Nagahara, N; Kashihara, T; Hirai, S; Toguchi, H

    1995-03-01

    Two types of polyglycerol ester of fatty acid (PGEF)-based microspheres were prepared: Carbopol 934P (CP)-coated microspheres (CPC-microspheres) and CP-dispersion microspheres (CPD-microspheres). Comparative studies on mucoadhesion were done with these microspheres and PGEF-based microspheres without CP (PGEF-microspheres). In an in vitro adhesion test, the CPD-microspheres adhered strongly to mucosa prepared from rat stomach and small intestine because each CP particle in the CPD-microsphere was hydrated and swelled with part of it remaining within the microsphere and part extending to the surface serving to anchor the microsphere to the mucus layer. The gastrointestinal transit patterns after administration of the CPD-microspheres and PGEF-microspheres to fasted rats were fitted to a model in which the microspheres are emptied from the stomach monoexponentially with a lag time and then transit through the small intestine at zero-order. Parameters obtained by curve fitting confirmed that the gastrointestinal transit time of the CPD-microspheres was prolonged compared with that of the PGEF-microspheres. MRT in the gastrointestinal tract was also prolonged after administration of the CPD-microspheres compared with that following the administration of the PGEF-microspheres.

  4. Bioadhesive fluorescent microspheres as visible carriers for local delivery of drugs. II: Uptake of insulin-loaded PCEFB/PLGA microspheres by the gastrointestinal tract.

    PubMed

    Li, Y; Jiang, H L; Jin, J F; Zhu, K J

    2004-01-01

    Uptake of novel inherently fluorescent microspheres composed of a luminescent polyanhydride, poly[p-(carboxyethylformamido)-benzoic anhydride] (PCEFB), and poly(lactide-co-glycolide) (PLGA) (2:1, weight ratio) by the gastrointestinal tract was evaluated by fluorescent microscopy. Oral efficiency of the incorporated insulin also was determined by measuring reduction of plasma glucose levels after feeding diabetic rats with a single dose of the microspheres. We found that PCEFB/PLGA microspheres could adhere to the intestinal epithelium and traverse the absorptive cells. A large number of the spheres were observed in spleen, whereas few were detected in liver within the evaluated period of time. Apparent reduction of the plasma glucose levels was observed over a span of 6 h postfeeding. The unique properties of the delivery system such as biodegradability, bioadhesivity, and inherently luminescent characteristics render it an ideal "visible" tracer for monitoring oral fate of polymeric microspheres. PMID:15736827

  5. Lanthanum-Induced Gastrointestinal Histiocytosis

    PubMed Central

    Araya, Hiwot; Longacre, Teri A.; Pasricha, Pankaj J.

    2015-01-01

    A patient with end-stage renal disease (ESRD) on hemodialysis presented with fever, anorexia, and nausea shortly after starting oral lanthanum carbonate for phosphate control. Gastric and duodenal biopsies demonstrated diffuse histiocytosis with intracellular aggregates of basophilic foreign material. Transmission electron microscopy, an underutilized diagnostic test, revealed the nature of the aggregates as heavy metal particles, consistent with lanthanum. Symptoms and histiocytosis improved after discontinuation of lanthanum. Lanthanum may be an underdiagnosed cause of gastrointestinal histiocytosis. PMID:26157959

  6. Microspheres

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Vital information on a person's physical condition can be obtained by identifying and counting the population of T-cells and B-cells, lymphocytes of the same shape and size that help the immune system protect the body from the invasion of disease. The late Dr. Alan Rembaum developed a method for identifying the cells. The method involved tagging the T-cells and B-cells with microspheres of different fluorescent color. Microspheres, which have fluorescent dye embedded in them, are chemically treated so that they can link with antibodies. With the help of a complex antibody/antigen reaction, the microspheres bind themselves to specific 'targets,' in this case the T-cells or B-cells. Each group of cells can then be analyzed by a photoelectronic instrument at different wavelengths emitted by the fluorescent dyes. Same concept was applied to the separation of cancer cells from normal cells. Microspheres were also used to conduct many other research projects. Under a patent license Magsphere, Inc. is producing a wide spectrum of microspheres on a large scale and selling them worldwide for various applications.

  7. Cytokine-induced alterations of gastrointestinal motility in gastrointestinal disorders

    PubMed Central

    Akiho, Hirotada; Ihara, Eikichi; Motomura, Yasuaki; Nakamura, Kazuhiko

    2011-01-01

    Inflammation and immune activation in the gut are usually accompanied by alteration of gastrointestinal (GI) motility. In infection, changes in motor function have been linked to host defense by enhancing the expulsion of the infectious agents. In this review, we describe the evidence for inflammation and immune activation in GI infection, inflammatory bowel disease, ileus, achalasia, eosinophilic esophagitis, microscopic colitis, celiac disease, pseudo-obstruction and functional GI disorders. We also describe the possible mechanisms by which inflammation and immune activation in the gut affect GI motility. GI motility disorder is a broad spectrum disturbance of GI physiology. Although several systems including central nerves, enteric nerves, interstitial cells of Cajal and smooth muscles contribute to a coordinated regulation of GI motility, smooth muscle probably plays the most important role. Thus, we focus on the relationship between activation of cytokines induced by adaptive immune response and alteration of GI smooth muscle contractility. Accumulated evidence has shown that Th1 and Th2 cytokines cause hypocontractility and hypercontractility of inflamed intestinal smooth muscle. Th1 cytokines downregulate CPI-17 and L-type Ca2+ channels and upregulate regulators of G protein signaling 4, which contributes to hypocontractility of inflamed intestinal smooth muscle. Conversely, Th2 cytokines cause hypercontractilty via signal transducer and activator of transcription 6 or mitogen-activated protein kinase signaling pathways. Th1 and Th2 cytokines have opposing effects on intestinal smooth muscle contraction via 5-hydroxytryptamine signaling. Understanding the immunological basis of altered GI motor function could lead to new therapeutic strategies for GI functional and inflammatory disorders. PMID:22013552

  8. Piperine containing floating microspheres: an approach for drug targeting to the upper gastrointestinal tract.

    PubMed

    Khatri, Smriti; Awasthi, Rajendra

    2016-06-01

    The purpose of this investigation was to prepare and characterize acyclovir loaded floating microspheres by emulsification solvent evaporation method. Piperine was added to investigate its effect on acyclovir bioavailability. The microspheres were characterized for size, shape, entrapment efficiency, in vitro drug release, and in vivo pharmacokinetic parameters. The morphological characterization of microspheres was done using a scanning electron microscope. The microspheres were spherical and had particle size in the range of 400 to 525 μm. The percent drug entrapment efficiency varied between 56.12 ± 1.32 % to 87.32 ± 5.28 %. The drug release was decreased at higher polymer concentrations. Nearly two times higher AUC0-24 value of acyclovir-loaded piperine containing microspheres (15614.13 ± 6953.13 ng h ml(-1)) was observed as compared to the drug solution (7552.33 ± 3219.09 ng h ml(-1)). Under the accelerated storage conditions, the best selected formulation was found to be stable for 90 days. The preliminary results of this study suggest that the developed microspheres containing acyclovir could enhance drug entrapment efficiency, reduce initial burst release, and prolong the drug release with enhanced bioavailability. PMID:26902907

  9. Asbestos-Induced Gastrointestinal Cancer: An Update

    PubMed Central

    Kim, Seok Jo; Williams, David; Cheresh, Paul; Kamp, David W

    2016-01-01

    Asbestos-related diseases, such as malignancies and asbestosis, remain a significant occupational and public health concern. Asbestos is still widely used in many developing countries despite being a recognized carcinogen that has been banned over 50 countries. The prevalence and mortality from asbestos-related diseases continue to pose challenges worldwide. Many countries are now experiencing an epidemic of asbestos-related disease that is the legacy of occupational exposure during the 20th century because of the long latency period (up to 40 years) between initial asbestos exposure and exhibition of disease. However, the gastrointestinal (GI) cancers resulting from asbestos exposure are not as clearly defined. In this review, we summarize some of the recent epidemiology of asbestos-related diseases and then focus on the evidence implicating asbestos in causing GI malignancies. We also briefly review the important new pathogenic information that has emerged over the past several years that may account for asbestos-related gastrointestinal cancers. All types of asbestos fibers have been implicated in the mortality and morbidity from GI malignancies but the collective evidence to date is mixed. Although the molecular basis of GI cancers arising from asbestos exposure is unclear, there have been significant advances in our understanding of mesothelioma and asbestosis that may contribute to the pathophysiology underlying asbestos-induced GI cancers. The emerging new evidence into the pathogenesis of asbestos toxicity is providing insights into the molecular basis for developing novel therapeutic strategies for asbestos-related diseases in future management. PMID:27158561

  10. Protective effects of alginate–chitosan microspheres loaded with alkaloids from Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. (Zuojin Pill) against ethanol-induced acute gastric mucosal injury in rats

    PubMed Central

    Wang, Qiang-Song; Zhu, Xiao-Ning; Jiang, Heng-Li; Wang, Gui-Fang; Cui, Yuan-Lu

    2015-01-01

    Zuojin Pill (ZJP), a traditional Chinese medicine formula, consists of Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in a ratio of 6:1 (w/w) and was first recorded in “Danxi’s experiential therapy” for treating gastrointestinal disorders in the 15th century. However, the poor solubility of alkaloids from ZJP restricted the protective effect in treating gastritis and gastric ulcer. The aim of the study was to investigate the protective mechanism of mucoadhesive microspheres loaded with alkaloids from C. chinensis Franch. and E. rutaecarpa (Juss.) Benth. on ethanol-induced acute gastric mucosal injury in rats. Surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug release, mucoadhesiveness, and fluorescent imaging of the microspheres in gastrointestinal tract were studied. The results showed that the mucoadhesive microspheres loaded with alkaloids could sustain the release of drugs beyond 12 hours and had gastric mucoadhesive property with 82.63% retention rate in vitro. The fluorescence tracer indicated high retention of mucoadhesive microspheres within 12 hours in vivo. The mucoadhesive microspheres loaded with alkaloids could reduce the gastric injury by decreasing the mucosal lesion index, increasing the percentage of inhibition and increasing the amount of mucus in the gastric mucosa in an ethanol-induced gastric mucosal injury rat model. Moreover, the mucoadhesive microspheres loaded with alkaloids reduce the inflammatory response by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), downregulating the mRNA expression of inducible nitric oxide synthase, TNF-α, and IL-1β in gastric mucosa. All the results indicate that mucoadhesive microspheres loaded with alkaloids could not only increase the residence time of alkaloids in rat stomach, but also exert gastroprotective effects through reducing the inflammatory response on ethanol-induced gastric mucosal damage. Thus

  11. Protective effects of alginate-chitosan microspheres loaded with alkaloids from Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. (Zuojin Pill) against ethanol-induced acute gastric mucosal injury in rats.

    PubMed

    Wang, Qiang-Song; Zhu, Xiao-Ning; Jiang, Heng-Li; Wang, Gui-Fang; Cui, Yuan-Lu

    2015-01-01

    Zuojin Pill (ZJP), a traditional Chinese medicine formula, consists of Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in a ratio of 6:1 (w/w) and was first recorded in "Danxi's experiential therapy" for treating gastrointestinal disorders in the 15th century. However, the poor solubility of alkaloids from ZJP restricted the protective effect in treating gastritis and gastric ulcer. The aim of the study was to investigate the protective mechanism of mucoadhesive microspheres loaded with alkaloids from C. chinensis Franch. and E. rutaecarpa (Juss.) Benth. on ethanol-induced acute gastric mucosal injury in rats. Surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug release, mucoadhesiveness, and fluorescent imaging of the microspheres in gastrointestinal tract were studied. The results showed that the mucoadhesive microspheres loaded with alkaloids could sustain the release of drugs beyond 12 hours and had gastric mucoadhesive property with 82.63% retention rate in vitro. The fluorescence tracer indicated high retention of mucoadhesive microspheres within 12 hours in vivo. The mucoadhesive microspheres loaded with alkaloids could reduce the gastric injury by decreasing the mucosal lesion index, increasing the percentage of inhibition and increasing the amount of mucus in the gastric mucosa in an ethanol-induced gastric mucosal injury rat model. Moreover, the mucoadhesive microspheres loaded with alkaloids reduce the inflammatory response by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), downregulating the mRNA expression of inducible nitric oxide synthase, TNF-α, and IL-1β in gastric mucosa. All the results indicate that mucoadhesive microspheres loaded with alkaloids could not only increase the residence time of alkaloids in rat stomach, but also exert gastroprotective effects through reducing the inflammatory response on ethanol-induced gastric mucosal damage. Thus, these

  12. Uniform and amorphous rifampicin microspheres obtained by freezing induced LLPS during lyophilization.

    PubMed

    Liu, Chun; Kong, Chao; Wu, Guoliang; Zhu, Junhao; Javid, Babak; Qian, Feng

    2015-11-10

    By lyophilization of rifampicin (RIF) solution in TBA/water with various solvent compositions, uniform and amorphous rifampicin (RIF) microspheres were produced. Using 55% TBA solution, the obtained RIF microspheres have a mono-dispersive size distribution with diameters range from 1 to 3 μm. The RIF microspheres are found to be amorphous by X-ray diffraction, and are expected to dissolve much faster than the crystalline RIF upon inhalation. Mechanistic investigation revealed that the amorphous RIF microspheres were formed due to liquid-liquid phase separation (LLPS) occurred during the freezing of the TBA/water solution. We also observed that the RIF microspheres can be readily phagocytized by activated THP-1 cells within 15 min. The suitable size distribution, high solubility, and readiness for phagocytosis by macrophages, all suggest that the lyophilized amorphous RIF microspheres could be potentially used as an anti-tuberculosis inhalation therapy. In addition, similar process was used to lyophilize TBA/water solutions of several other drugs, including rifaximin, rifapentine, paclitaxel, and isoniazid. We found that for drugs with appropriate physiochemical properties, such as paclitaxel and rifaximin, mono-dispersive microspheres could be obtained as well, which demonstrated that freezing induced LLPS could be utilized as a novel particle engineering methodology to produce drug microspheres by lyophilization.

  13. Biodegradable polylactide microspheres enhance specific immune response induced by Hepatitis B surface antigen.

    PubMed

    Qiu, Shaohui; Wei, Qiang; Liang, Zhenglun; Ma, Guanghui; Wang, Lianyan; An, Wenqi; Ma, Xiaowei; Fang, Xin; He, Peng; Li, Hemin; Hu, Zhongyu

    2014-01-01

    Hepatitis B (HB) infection caused by Hepatitis B virus (HBV) is the most common liver disease in the world. HB vaccine, when administered in conjunction with alum adjuvants, induces Th2 immunity that confers protection against HBV. However, currently available vaccine formulations and adjuvants do not elicit adequate Th1 and CTL responses that are important for prevention of maternal transmission of the virus. Microspheres synthesized from poly (D, L-lactide-co-glycolide) (PLGA) or poly (D, L-lactide) (PLA) polymers have been considered as promising tools for in vivo delivery of antigens and drugs. Here we describe PLA microspheres synthesized by premix membrane emulsification method and their application in formulating a new microsphere based HB vaccine. To evaluate the immunogenicity of this microsphere vaccine, BALB/c mice were immunized with microsphere vaccine and a series of immunological assays were conducted. Results of Enzyme-linked ImmunoSpot (ELISPOT) assays revealed that the number of interferon-gamma (IFN-γ)-producing splenocytes and CD8(+) T cells increased significantly in the microsphere vaccine group. Microsphere vaccine group showed enhanced specific cell lysis when compared with HB surface antigen (HBsAg) only group in (51)Cr cytotoxicity assays. Moreover, microsphere vaccine elicited a comparable level of antibody production as that of HB vaccine administered with alum adjuvant. We show that phagocytosis of HBsAg by dendritic cells is more pronounced in microsphere vaccine group when compared with other control groups. These results clearly demonstrate the potential of using PLA microspheres as effective HB vaccine adjuvants for an enhanced Th1 immune response.

  14. Biodegradable polylactide microspheres enhance specific immune response induced by Hepatitis B surface antigen

    PubMed Central

    Qiu, Shaohui; Wei, Qiang; Liang, Zhenglun; Ma, Guanghui; Wang, Lianyan; An, Wenqi; Ma, Xiaowei; Fang, Xin; He, Peng; Li, Hemin; Hu, Zhongyu

    2014-01-01

    Hepatitis B (HB) infection caused by Hepatitis B virus (HBV) is the most common liver disease in the world. HB vaccine, when administered in conjunction with alum adjuvants, induces Th2 immunity that confers protection against HBV. However, currently available vaccine formulations and adjuvants do not elicit adequate Th1 and CTL responses that are important for prevention of maternal transmission of the virus. Microspheres synthesized from poly (D, L-lactide-co-glycolide) (PLGA) or poly (D, L-lactide) (PLA) polymers have been considered as promising tools for in vivo delivery of antigens and drugs. Here we describe PLA microspheres synthesized by premix membrane emulsification method and their application in formulating a new microsphere based HB vaccine. To evaluate the immunogenicity of this microsphere vaccine, BALB/c mice were immunized with microsphere vaccine and a series of immunological assays were conducted. Results of Enzyme-linked ImmunoSpot (ELISPOT) assays revealed that the number of interferon-gamma (IFN-γ)-producing splenocytes and CD8+ T cells increased significantly in the microsphere vaccine group. Microsphere vaccine group showed enhanced specific cell lysis when compared with HB surface antigen (HBsAg) only group in 51Cr cytotoxicity assays. Moreover, microsphere vaccine elicited a comparable level of antibody production as that of HB vaccine administered with alum adjuvant. We show that phagocytosis of HBsAg by dendritic cells is more pronounced in microsphere vaccine group when compared with other control groups. These results clearly demonstrate the potential of using PLA microspheres as effective HB vaccine adjuvants for an enhanced Th1 immune response. PMID:25424942

  15. Preparation of porous microsphere-scaffolds by electrohydrodynamic forming and thermally induced phase separation.

    PubMed

    Ghanbar, Hanif; Luo, C J; Bakhshi, Poonam; Day, Richard; Edirisinghe, Mohan

    2013-07-01

    The availability of forming technologies able to mass produce porous polymeric microspheres with diameters ranging from 150 to 300 μm is significant for some biomedical applications where tissue augmentation is required. Moreover, appropriate assembly of microspheres into scaffolds is an important challenge to enable direct usage of the as-formed structures in treatments. This work reports the production of poly (glycolic-co-lactic acid) and poly (ε-caprolactone) microspheres under ambient conditions using one-step electrohydrodynamic jetting (traditionally known as atomisation) and thermally induced phase separation (TIPS). To ensure robust production for practical uses, this work presents 12 comprehensive parametric mode mappings of the diameter distribution profiles of the microspheres obtained over a broad range of key processing parameters and correlating of this with the material parameters of 5 different polymer solutions of various concentrations. Poly (glycolic-co-lactic acid) (PLGA) in Dimethyl carbonate (DMC), a low toxicity solvent with moderate conductivity and low dielectric constant, generated microspheres within the targeted diameter range of 150-300 μm. The fabrication of the microspheres suitable for formation of the scaffold structure is achieved by changing the collection method from distilled water to liquid nitrogen and lyophilisation in a freeze dryer. PMID:23623059

  16. Imaging of Drug-induced Complications in the Gastrointestinal System.

    PubMed

    McGettigan, Melissa J; Menias, Christine O; Gao, Zhenqiang J; Mellnick, Vincent M; Hara, Amy K

    2016-01-01

    Drug-induced injury commonly affects the gastrointestinal and hepatobiliary systems because of the mechanisms of absorption and metabolism. In pill esophagitis, injury is frequently related to direct contact with the esophageal mucosa, resulting in small superficial ulcers in the mid esophagus. Nonsteroidal anti-inflammatory drugs can lead to gastrointestinal tract ulcers and small bowel mucosal diaphragms (thin weblike strictures). Injury to the pancreatic and hepatobiliary systems can manifest as pancreatitis, acute or chronic hepatitis, cholestasis, or steatosis and steatohepatitis (which may progress to cirrhosis). Various drugs may also insult the hepatic vasculature, resulting in Budd-Chiari and sinusoidal obstructive syndromes. Focal lesions such as hepatic adenomas may develop after use of oral contraceptives or anabolic steroids. Ultrasonography, computed tomography, and magnetic resonance imaging can aid in diagnosis of drug-induced injuries and often are necessary to exclude other causes. PMID:26761532

  17. Experimental glaucoma induced by ocular injection of magnetic microspheres.

    PubMed

    Bunker, Shannon; Holeniewska, Joanna; Vijay, Sauparnika; Dahlmann-Noor, Annegret; Khaw, Peng; Ng, Yin-Shan; Shima, David; Foxton, Richard

    2015-01-01

    Progress in understanding the pathophysiology, and providing novel treatments for glaucoma is dependent on good animal models of the disease. We present here a protocol for elevating intraocular pressure (IOP) in the rat, by injecting magnetic microspheres into the anterior chamber of the eye. The use of magnetic particles allows the user to manipulate the beads into the iridocorneal angle, thus providing a very effective blockade of fluid outflow from the trabecular meshwork. This leads to long-lasting IOP rises, and eventually neuronal death in the ganglion cell layer (GCL) as well as optic nerve pathology, as seen in patients with the disease. This method is simple to perform, as it does not require machinery, specialist surgical skills, or many hours of practice to perfect. Furthermore, the pressure elevations are very robust, and reinjection of the magnetic microspheres is not usually required unlike in some other models using plastic beads. Additionally, we believe this method is suitable for adaptation for the mouse eye.

  18. A novel, smart microsphere with K(+)-induced shrinking and aggregating properties based on a responsive host-guest system.

    PubMed

    Jiang, Ming-Yue; Ju, Xiao-Jie; Fang, Lu; Liu, Zhuang; Yu, Hai-Rong; Jiang, Lu; Wang, Wei; Xie, Rui; Chen, Qianming; Chu, Liang-Yin

    2014-01-01

    A novel type of smart microspheres with K(+)-induced shrinking and aggregating properties is designed and developed on the basis of a K(+)-recognition host-guest system. The microspheres are composed of cross-linked poly(N-isopropylacrylamide-co-acryloylamidobenzo-15-crown-5) (P(NIPAM-co-AAB15C5)) networks. Due to the formation of stable 2:1 "sandwich-type" host-guest complexes between 15-crown-5 units and K(+) ions, the P(NIPAM-co-AAB15C5) microspheres significantly exhibit isothermally and synchronously K(+)-induced shrinking and aggregating properties at a low K(+) concentration, while other cations (e.g., Na(+), H(+), NH4(+), Mg(2+), or Ca(2+)) cannot trigger such response behaviors. Effects of chemical compositions of microspheres on the K(+)-induced shrinking and aggregating behaviors are investigated systematically. The K(+)-induced aggregating sensitivity of the P(NIPAM-co-AAB15C5) microspheres can be enhanced by increasing the content of crown ether units in the polymeric networks; however, it is nearly not influenced by varying the monomer and cross-linker concentrations in the microsphere preparation. State diagrams of the dispersed-to-aggregated transformation of P(NIPAM-co-AAB15C5) microspheres in aqueous solutions as a function of temperature and K(+) concentration are constructed, which provide valuable information for tuning the dispersed/aggregated states of microspheres by varying environmental K(+) concentration and temperature. The microspheres with synchronously K(+)-induced shrinking and aggregating properties proposed in this study provide a brand-new model for designing novel targeted drug delivery systems.

  19. Microwave-induced fast crystallization of amorphous hierarchical anatase microspheres

    PubMed Central

    2014-01-01

    The fabrication of hierarchical anatase microspheres with potential photocatalytic properties eventually comprises a consolidation step in which a high degree of crystalline order is typically achieved through conventional electric heating treatments. This however entails a substantial reduction in the specific surface area and porosity of the powders, with the consequent deterioration in their photocatalytic response. Here, we have tested the employ of microwave heating as an alternative energy-saving sintering method to promote fast crystallization. The results obtained suggest that under the microwave radiation, the TiO2 hierarchical structures can effectively crystallize in a drastically reduced heating time, allowing the specific surface area and the porosity to be kept in the high values required for an improved photocatalytic performance. PMID:24948894

  20. Metal ion-induced alginate-locust bean gum IPN microspheres for sustained oral delivery of aceclofenac.

    PubMed

    Jana, Sougata; Gandhi, Arijit; Sheet, Subrata; Sen, Kalyan Kumar

    2015-01-01

    The alginate microspheres represent a useful tool for sustained oral delivery of drugs but exhibit several problems associated with the stability and rapid release of drugs at higher pH values. To overcome these drawbacks, alginate-locust bean gum (LBG) interpenetrating microspheres were prepared by calcium ion (Ca(+2)) induced ionotropic gelation technique for prolonged release of aceclofenac. The drug entrapment efficiency of these microspheres was found to be 59-93%. The microspheres lied in the size range of 406-684μm. Scanning electron microscopy revealed spherical shape of the microspheres. No drug-polymer interaction was evident after infrared spectroscopy analysis. The microspheres provided sustained release of aceclofenac in phosphate buffer solution (pH 6.8) over a period of 8h. The drug release data were fitted into the Korsmeyer-Peppas model and the drug release was found to follow anomalous (non-Fickian) diffusion mechanism. Pharmacodynamic study of the microspheres showed a prolonged anti-inflammatory activity in carrageenan-induced rat paw model following oral administration.

  1. Metal ion-induced alginate-locust bean gum IPN microspheres for sustained oral delivery of aceclofenac.

    PubMed

    Jana, Sougata; Gandhi, Arijit; Sheet, Subrata; Sen, Kalyan Kumar

    2015-01-01

    The alginate microspheres represent a useful tool for sustained oral delivery of drugs but exhibit several problems associated with the stability and rapid release of drugs at higher pH values. To overcome these drawbacks, alginate-locust bean gum (LBG) interpenetrating microspheres were prepared by calcium ion (Ca(+2)) induced ionotropic gelation technique for prolonged release of aceclofenac. The drug entrapment efficiency of these microspheres was found to be 59-93%. The microspheres lied in the size range of 406-684μm. Scanning electron microscopy revealed spherical shape of the microspheres. No drug-polymer interaction was evident after infrared spectroscopy analysis. The microspheres provided sustained release of aceclofenac in phosphate buffer solution (pH 6.8) over a period of 8h. The drug release data were fitted into the Korsmeyer-Peppas model and the drug release was found to follow anomalous (non-Fickian) diffusion mechanism. Pharmacodynamic study of the microspheres showed a prolonged anti-inflammatory activity in carrageenan-induced rat paw model following oral administration. PMID:25111495

  2. Homogeneous and organized differentiation within embryoid bodies induced by microsphere-mediated delivery of small molecules

    PubMed Central

    Carpenedo, Richard L.; Bratt-Leal, Andrés M.; Marklein, Ross A.; Seaman, Scott A.; Bowen, Nathan J.; McDonald, John F.; McDevitt, Todd C.

    2010-01-01

    Cell specification and tissue formation during embryonic development are precisely controlled by the local concentration and temporal presentation of morphogenic factors. Similarly, pluripotent embryonic stem cells can be induced to differentiate in vitro into specific phenotypes in response to morphogen treatment. Embryonic stem cells (ESCs) are commonly differentiated as 3D spheroids referred to as embryoid bodies (EBs); however, differentiation of cells within EBs is typically heterogeneous and disordered. In this study, we demonstrate that in contrast to soluble morphogen treatment, delivery of morphogenic factors directly within EB microenvironments in a spatiotemporally controlled manner using polymer microspheres yields homogeneous, synchronous and organized ESC differentiation. Degradable PLGA microspheres releasing retinoic acid were incorporated directly within EBs and induced the formation of cystic spheroids uniquely resembling the phenotype and structure of early streak mouse embryos (E6.75), with an exterior of FOXA2+ visceral endoderm enveloping an epiblast-like layer of OCT4+ cells. These results demonstrate that controlled morphogen presentation to stem cells using degradable microspheres more efficiently directs cell differentiation and tissue formation than simple soluble delivery methods and presents a unique route to study the spatiotemporal effects of morphogenic factors on embryonic developmental processes in vitro. PMID:19162317

  3. Polymeric microspheres

    DOEpatents

    Walt, David R.; Mandal, Tarun K.; Fleming, Michael S.

    2004-04-13

    The invention features core-shell microsphere compositions, hollow polymeric microspheres, and methods for making the microspheres. The microspheres are characterized as having a polymeric shell with consistent shell thickness.

  4. Heparin as a pharmacologic intervention to induce positive scintiscan in occult gastrointestinal bleeding

    SciTech Connect

    Chaudhuri, T.K.; Brantly, M.

    1984-04-01

    The value of using heparin as a pharmacologic intervention to induce a positive scintiscan was studied in a patient with chronic occult gastrointestinal bleeding. When all standard diagnostic tests (upper and lower gastrointestinal series, upper and lower endoscopy, and conventional noninterventional Tc-99m RBC imaging) fail to detect and localize gastrointestinal bleeding in a patient who has definite clinical evidence (guaiac positive stool and dropping hemoglobin, hematocrit) of chronic occult gastrointestinal oozing, heparin may be used (with proper precaution) as a last resort to aid in the scintigraphic detection and localization of chronic occult gastrointestinal bleeding.

  5. Upper gastrointestinal bleeding: gallstone-induced auto-sphincterotomy

    PubMed Central

    Kalipershad, Sujala; Chung, Kin Tong; Jehangir, Ernest

    2012-01-01

    A 67-year-old gentleman with no significant medical history of note presented with sudden onset of epigastric pain, coffee ground vomiting and passing black tarry stool. A series of investigations including blood tests, ultrasound scan, CT abdomen and pelvis with contrast and endoscopy failed to reveal any site of active bleeding. The mystery remained and the patient continued to have upper gastrointestinal bleeding. A second CT abdomen and pelvis with contrast was carried out and showed evidence of contrast extravasation into the duodenum (figure 3). An exploratory laparotomy showed no obvious site of haemorrhage and a loop jejunostomy was performed. The diagnosis of gallstone-induced auto-sphincterotomy was only made, using gastroscope via jejunostomy, when a big gallstone was found in the third part of the duodenum and the papilla was ruptured (figure 5). PMID:22914239

  6. Uniform alumina microspheres from temperature induced forming in a microfluidic T-junction

    NASA Astrophysics Data System (ADS)

    Wilson, James; Wehking, Jonathan D.; Kumar, Ranganathan

    2013-11-01

    This Letter explores a method for the manufacture of solid microspheres of 30 μm, from liquid droplets with nanosuspensions of 20 nm alumina in a microfluidic T-junction. These droplets are heated downstream where solidification takes place due to Temperature Induced Forming (TIF). TIF occurs as temperature sensitive alumina solubility leads to weakening electrostatic double-layer dispersing forces resulting in the formation of a solid structure. Manipulation of the flow characteristics and material properties of the continuous and dispersed fluids provides control of droplet production over a range of conditions and allows for a robust manufacturing facility capable of producing particles of various sizes.

  7. Radiation-induced grafting of carbon nanotubes on HPLC silica microspheres: theoretical and practical aspects.

    PubMed

    Speltini, Andrea; Merli, Daniele; Dondi, Daniele; Milanese, Chiara; Galinetto, Pietro; Bozzetti, Carlo; Profumo, Antonella

    2013-07-01

    Multi-walled carbon nanotubes (MWCNTs) were grafted for the first time by γ-radiation onto silica microspheres in the presence of polybutadiene (PB) as the linking agent, obtaining a novel hybrid material with chromatographic properties, with an alternative approach to the existing procedures. The synthesis involves the one-pot γ-radiation-induced grafting of MWCNTs onto silica microspheres in the presence of PB as a linking agent. PB also serves as a coating layer of the silica particles, to which MWCNTs are anchored through stable chemical bonds formed via radical chain reaction with the polymer. The product (MWCNT-PB-modified silica) resulted in MWCNT bundles interlaying the silica particles which acted as a support and as a spacer. This new material highlights the unquestionable properties of CNTs also when grafted in a composite, thus allowing the disposition of a more robust material whose properties are still related to the nanotube structure. The grafting was confirmed by Raman spectroscopy. The surface area, determined by BET isotherms, resulted in 132 m(2) g(-1), about 34% lower than that of pure silica, pointing to the cross-linking effect of PB in the silica matrix. The evaluation of MWCNT-PB-modified silica as a LC stationary phase was performed by separation of aromatics, with satisfactory resolution and reproducibility, while structural selectivity was proved by isomer separation. A good resolution was obtained also for acid/basic compounds as barbiturates. A comparison with a commercial C18 sorbent highlighted the advantage in using the CNT column for separating aromatic hydrocarbons. Control experiments on the PB-coated silica column proved the key role of MWCNTs in the chromatographic performance. PMID:23678482

  8. Effects of naftidrofuryl oxalate on microsphere embolism-induced decrease in regional blood flow of rat brain.

    PubMed Central

    Miyake, K.; Takagi, N.; Takeo, S.

    1994-01-01

    1. The purpose of the present study was to determine whether naftidrofuryl oxalate (naftidrofuryl), a vasodilator, is capable of improving brain regional blood flow of animals in sustained ischaemia. 2. Cerebral ischaemia was induced by injecting 900 microspheres (48 microns in diameter) into the right internal carotid artery of rats. Cerebral blood flow of brain regions was measured by a hydrogen clearance method on the 3rd, 7th and 28th days after the onset of ischaemia. Ischaemic animals were treated with naftidrofuryl, 15 mg kg-1 day-1 i.p., from the first to 28th day. 3. Microsphere-embolism caused a sustained decrease in cortical and striatal blood flow over a period of 28 days, whereas hippocampal blood flow was decreased on the 3rd day but not on the 7th or 28th day. On the 3rd day, the striatal and hippocampal but not cortical blood flow of naftidrofuryl-treated, microsphere-embolized rats was higher than untreated rats. On the 7th and 28th days, the cortical and striatal blood flow of the treated and untreated animals did not differ. 4. Brain slices from microsphere-embolized rats contained areas, which were not stained with triphenyltetrazolium chloride (TTC), to a similar degree on the 3rd, 7th and 28th days, indicating the genesis of cerebral infarction. TTC-unstained areas of microsphere-embolized rats that had received naftidrofuryl treatment were smaller than those of untreated rats on the 3rd and 7th days, but not on the 28th day.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8032646

  9. Changes in the lactate threshold during treadmill exercise after microsphere-induced infarction in rats.

    PubMed

    Takahashi, Hisashi; Himi, Naoyuki; Kuniyasu, Katsushi; Koga, Tomoshige

    2012-11-01

    The aim of this study was to clarify changes in the lactate threshold (LT) in the acute period after cerebral infarction. Cerebral infarction was induced by the injection of microspheres (MS) into the right internal carotid artery. To estimate the degree of neurologic deficit caused by surgery, the behaviors of all rats were evaluated in terms of typical symptoms of stroke in rats. The rotarod test was used to evaluate equilibrium function. Rats were forced to perform stepwise treadmill exercises, and serial changes in blood lactate concentration were measured for determination of the LT. The average treadmill speed at the LT and the rotarod test performance in MS rats was significantly lower than those in sham-operated rats on postsurgery day 2. However, although neurologic deficits disappeared on postsurgery day 7 in MS rats, LT level and rotarod test performance were significantly lower than in sham-operated rats. These results suggest that the decrease in LT in the acute period after cerebral infarction might be induced by impaired equilibrium function. Other possibilities are discussed as well.

  10. Carbohydrate-dependent, exercise-induced gastrointestinal distress.

    PubMed

    de Oliveira, Erick Prado; Burini, Roberto C

    2014-10-01

    Gastrointestinal (GI) problems are a common concern of athletes during intense exercise. Ultimately, these symptoms can impair performance and possibly prevent athletes from winning or even finishing a race. The main causes of GI problems during exercise are mechanical, ischemic and nutritional factors. Among the nutritional factors, a high intake of carbohydrate and hyperosmolar solutions increases GI problems. A number of nutritional manipulations have been proposed to minimize gastrointestinal symptoms, including the use of multiple transportable carbohydrates. This type of CHO intake increases the oxidation rates and can prevent the accumulation of carbohydrate in the intestine. Glucose (6%) or glucose plus fructose (8%-10%) beverages are recommended in order to increase CHO intake while avoiding the gastric emptying delay. Training the gut with high intake of CHO may increase absorption capacity and probably prevent GI distress. CHO mouth rinse may be a good strategy to enhance performance without using GI tract in exercises lasting less than an hour. Future strategies should be investigated comparing different CHO types, doses, and concentration in exercises with the same characteristics. PMID:25314645

  11. Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress

    PubMed Central

    de Oliveira, Erick Prado; Burini, Roberto C.

    2014-01-01

    Gastrointestinal (GI) problems are a common concern of athletes during intense exercise. Ultimately, these symptoms can impair performance and possibly prevent athletes from winning or even finishing a race. The main causes of GI problems during exercise are mechanical, ischemic and nutritional factors. Among the nutritional factors, a high intake of carbohydrate and hyperosmolar solutions increases GI problems. A number of nutritional manipulations have been proposed to minimize gastrointestinal symptoms, including the use of multiple transportable carbohydrates. This type of CHO intake increases the oxidation rates and can prevent the accumulation of carbohydrate in the intestine. Glucose (6%) or glucose plus fructose (8%–10%) beverages are recommended in order to increase CHO intake while avoiding the gastric emptying delay. Training the gut with high intake of CHO may increase absorption capacity and probably prevent GI distress. CHO mouth rinse may be a good strategy to enhance performance without using GI tract in exercises lasting less than an hour. Future strategies should be investigated comparing different CHO types, doses, and concentration in exercises with the same characteristics. PMID:25314645

  12. Coupling Light from a High-Q Microsphere Resonator Using a UV-induced Surface Grating

    NASA Technical Reports Server (NTRS)

    Ilchenko, V. S.; Starodubov, D. S.; Gorodetsky, M. L.; Maleki, L.; Feinberg, J.

    2000-01-01

    High-Q microspheres with whispering-gallery modes have very narrow resonances that can be used for fiber-optic filters, ultra-compact narrow-linewidth lasers and optical/microwave oscillators. Whispering-gallery modes were previously excited in microspheres using evanescent optical fields. The necessary phase synchronism was obtained by adjusting the incident angle of input light beam (prism coupler) or adjustment of the waveguide propagation constant (fiber taper coupler). For many applications, however, bulky near-field couplers are undesirable. They compromise the symmetry and generate stray fields. Also, the control of coupling is crucial for the performance of microsphere resonators: in analogy with radio frequency circuits, the loading Q-factor should be less than the intrinsic Q-factor, Q(sub L) less than or equal to Q(sub O). Ideally one should combine a stable coupling element and a resonator into a single microsphere component.

  13. An erythromycin derivative, EM-523, induces motilin-like gastrointestinal motility in dogs.

    PubMed

    Inatomi, N; Satoh, H; Maki, Y; Hashimoto, N; Itoh, Z; Omura, S

    1989-11-01

    The effect of an erythromycin derivative, EM-523, on gastrointestinal motility was investigated in conscious dogs and compared with that of motilin cisapride, trimebutine and metoclopramide. In the fasting state, EM-523 given i.v. or i.d. at 3 micrograms/kg or more induced contractions in the stomach that migrated along the small intestine. The pattern of the contractions was very similar to that induced by motilin. In the digestive state, EM-523 increased the amplitude of gastric contractions. Cisapride and metoclopramide increased gastrointestinal motility both in the fasting and digestive states; however, their contractile pattern was different from that of EM-523. Trimebutine did not induce gastric motility in the fasting state but rather decreased gastric motility in the digestive state. The contractions induced by EM-523 and motilin were inhibited by atropine but were not affected by naloxone, suggesting that the cholinergic pathway is important in the exertion of their action. These results indicate that EM-523 mimics motilin in stimulating gastrointestinal motility and that this agent may be useful treat gastrointestinal disorders such as gastric stasis, gastroesophageal reflux, and postoperative ileus, and so forth. PMID:2810120

  14. Food-dependent, exercise-induced gastrointestinal distress.

    PubMed

    de Oliveira, Erick Prado; Burini, Roberto Carlos

    2011-01-01

    Among athletes strenuous exercise, dehydration and gastric emptying (GE) delay are the main causes of gastrointestinal (GI) complaints, whereas gut ischemia is the main cause of their nausea, vomiting, abdominal pain and (blood) diarrhea. Additionally any factor that limits sweat evaporation, such as a hot and humid environment and/or body dehydration, has profound effects on muscle glycogen depletion and risk for heat illness. A serious underperfusion of the gut often leads to mucosal damage and enhanced permeability so as to hide blood loss, microbiota invasion (or endotoxemia) and food-born allergen absorption (with anaphylaxis). The goal of exercise rehydration is to intake more fluid orally than what is being lost in sweat. Sports drinks provide the addition of sodium and carbohydrates to assist with intestinal absorption of water and muscle-glycogen replenishment, respectively. However GE is proportionally slowed by carbohydrate-rich (hyperosmolar) solutions. On the other hand, in order to prevent hyponatremia, avoiding overhydration is recommended. Caregiver's responsibility would be to inform athletes about potential dangers of drinking too much water and also advise them to refrain from using hypertonic fluid replacements.

  15. Child and parent perceived food-induced gastrointestinal symptoms and quality of life in children with functional gastrointestinal disorders.

    PubMed

    Carlson, Michelle J; Moore, Carolyn E; Tsai, Cynthia M; Shulman, Robert J; Chumpitazi, Bruno P

    2014-03-01

    It is unknown whether children with functional gastrointestinal (GI) disorders identify specific foods that exacerbate their GI symptoms. The objectives of this study were to determine the perceived role of food on GI symptoms and to determine the impact of food-induced symptoms on quality of life (QOL) in children with functional GI disorders. Between August and November 2010, 25 children ages 11 to 17 years old with functional GI disorders and a parent completed a food symptom association questionnaire and validated questionnaires assessing FGID symptoms and QOL. In addition, children completed a 24-hour food recall, participated in focus groups to identify problematic foods and any coping strategies, and discussed how their QOL was affected. Statistical analyses were conducted using χ2, t test, Mann-Whitney U test, Wilcoxon signed rank, and Spearman's ρ. Children identified a median of 11 (range=2 to 25) foods as exacerbating a GI symptom, with the most commonly identified foods being spicy foods, cow's milk, and pizza. Several coping strategies were identified, including consuming smaller portions, modifying foods, and avoiding a median of 8 (range=1 to 20) foods. Children reported that food-induced symptoms interfered with school performance, sports, and social activities. Although the parent's assessment of their child's QOL negatively correlated with the number of perceived symptom-inducing foods in their child, this relationship was not found in the children. Findings suggest that specific foods are perceived to exacerbate GI symptoms in children with functional GI disorders. In addition, despite use of several coping strategies, food-induced symptoms can adversely impact children's QOL in several important areas.

  16. Human cytomegalovirus induced pseudotumor of upper gastrointestinal tract mucosa: effects of long-term chronic disease?

    PubMed

    Reggiani Bonetti, Luca; Barresi, Valeria; Bertani, Angela; Maccio, Livia; Palmiere, Cristian

    2015-06-01

    Human cytomegalovirus-induced lesions resembling malignancies have been described in the gastrointestinal tract and include ulcerated or exophytic large masses. The aim of this study was to review the cases registered in the databases of two academic hospitals and formulate a hypothesis concerning the pathogenic mechanisms responsible for cytomegalovirus-induced pseudotumor development. All the diagnoses of human cytomegalovirus infections of the upper gastrointestinal tract recorded from 1991 to 2013 were reviewed. Cases of mucosal alterations misdiagnosed endoscopically as malignancies were selected. Large ulcers occurring in the stomach (three cases) and an irregular exophytic mass at the gastro-jejunal anastomosis were misdiagnosed endoscopically as malignancies (4 cases out of 53). Histologically, all lesions reflected hyperplastic mucosal changes with a prevalence of epithelial and stroma infected cells, without signs of cell atypia. The hypothesis presented is that the development of human cytomegalovirus-induced pseudotumors may be the morphological expression of chronic mucosa damage underlying long-term infection.

  17. Pathways involved in mild gastrointestinal inflammation induced by a low level exposure to a food contaminant.

    PubMed

    Anton, Pauline M; Theodorou, Vassilia; Roy, Sabine; Fioramonti, Jean; Bueno, Lionel

    2002-06-01

    Chronic gut inflammation is associated with radical oxygen species (ROS) genesis. ROS may activate certain transcription factors such as nuclear factor kappa beta (NF-kappaB), which regulates cyclooxygenase-2 (COX-2). Diquat, a food contaminant, is responsible for oxidative stress. This work aimed to establish the involvement of ROS and prostanoids on diquat-induced gastrointestinal inflammation and mast cell hyperplasia. Diquat increased gastrointestinal MPO activity and mast cell number. Its effect on gastric MPO activity was reversed by PD 138,387 (a COX-2 selective inhibitor) and PDTC (an inhibitor of NF-kappaB activation) but not by DMSO (a hydroxyl radical scavenger) and allopurinol (a xanthine oxidase inhibitor). In contrast, increased jejunal MPO activity was blocked by both DMSO, PD 138,387, and PDTC, while allopurinol enhanced it. PD 138,387 and PDTC reduced gastrointestinal mast cell number while DMSO and allopurinol did not Diquat-induced inflammation involves a gastrointestinal NF-kappaB activation and COX-2 dependent proinflammatory prostanoid synthesis. Furthermore, the hydroxyl radical is involved in intestinal but not gastric inflammation.

  18. Overexpression of GRF encapsulated in PLGA microspheres in animal skeletal muscle induces body weight gain.

    PubMed

    Zhang, Yong-liang; Ren, Xiao-hui; Liu, Song-cai; Dai, Jian-wei; Hao, Lin-lin; Jiang, Qing-yan

    2007-01-01

    Biodegradable nanospheres or microspheres have been widely used as a sustained release system for the delivery of bioagents. In the present study, injectable sustained-release growth hormone-releasing factor (GRF) (1-32) microspheres were prepared by a double emulsion-in liquid evaporation process using biodegradable polylactic-co-glycolic acid (PLGA) as the carrier. The entrapment efficiency was 89.79% and the mean particle size was 4.41 mum. The microspheres were injected into mouse tibialis muscle. After 30 days, mice injected with GRF (1-32) microspheres (group I) gained significantly more weight than any other treatment group, including mice injected with the naked plasmid (group II) (10.26 +/- 0.13 vs. 9.09 +/- 0.56; P < 0.05), a mixture of microspheres and plasmid (group III) (10.26 +/- 0.13 vs. 8.57 +/- 0.02; P < 0.05), or saline (IV) (10.26 +/- 0.13 vs. 6.47 +/- 0.26; P < 0.05). In addition, mice treated with the GRF (1-32) microspheres exhibited the highest expression levels of GRF as detected by PCR, RT-PCR, and ELISA (mean 2.56 +/- 0.40, P < 0.05, overall comparison of treatment with groups II, III, and IV). Additionally, rabbits were injected in the tibialis muscle with the same treatments described above. After 30 days, the group treated with GRF (1-32) microspheres gained the most weight. At day 30 postinjection, weight gain in group I was 63.93% higher than group II (plasmid) (877.10 +/- 24.42 vs. 535.05 +/- 26.38; P < 0.05), 108.59% higher than group III (blank MS) (877.10 +/- 24.42 vs. 420.50 +/- 19.39; P < 0.05), and 93.94% higher than group IV (saline) (877.10 +/- 24.42 vs. 452.25 +/- 27.38; P < 0.05). Furthermore, IGF-1 levels in the serum from GRF microsphere-treated group were elevated relative to all other groups. The present results suggest that encapsulation of GRF with PLGA increases GRF gene expression in muscle after local plasmid delivery, and stimulates significantly more weight gain than delivery of the naked plasmid alone.

  19. Ibuprofen-loaded porous microspheres suppressed the progression of monosodium iodoacetate-induced osteoarthritis in a rat model.

    PubMed

    Park, Jang Won; Yun, Young-Pil; Park, Kyeongsoon; Lee, Jae Yong; Kim, Hak-Jun; Kim, Sung Eun; Song, Hae-Ryong

    2016-11-01

    The objectives of this study were (1) to fabricate ibuprofen-loaded porous microspheres (IBU/PMSs), (2) to evaluate the in vitro anti-inflammatory effects of the microspheres using LPS-induced inflammation in cultured synoviocytes, and (3) to evaluate the in vivo effect of the IBU/PMSs on the progression of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in a rat model. A dose-dependent in vitro anti-inflammatory effect on pro-inflammatory cytokine markers (matrix metallopeptidase-3 (MMP-3), matrix metallopeptidase-13 (MMP-13), cyclooxygenase-2 (COX-2), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5)), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) was observed by confirming with real-time PCR analyses. In vivo, treatment with IBU/PMSs reduced MIA-stimulated mRNA expression of MMP-3, MMP-13, COX-2, ADAMTS-5, IL-6, and TNF-α in rat synoviocytes. In addition, we demonstrated that intra-articular IBU/PMSs suppressed the progression of MIA-induced OA in the rat model via anti-inflammatory mechanisms. In conclusion, IBU/PMSs are a promising therapeutic material to control the pain and progression of OA.

  20. Defect induced nickel, nitrogen-codoped mesoporous TiO2 microspheres with enhanced visible light photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Zou, Mingming; Feng, Lu; Ganeshraja, Ayyakannu Sundaram; Xiong, Fengqiang; Yang, Minghui

    2016-10-01

    Nickel, nitrogen-codoped mesoporous TiO2 microspheres (Ni-N-TiO2) with high surface area, and an effective direct band gap energy of ∼2.58 eV. Nickel sulfate used as the Ni source and ammonia gas as the N source here. The efficiency of the as-prepared samples was investigated by monitoring the degradation of Rhodamine B under visible light irradiation. The experimental results indicate that Ni-doped mesoporous TiO2 microspheres show higher photocatalytic activity than mesoporous TiO2 microspheres under visible light irradiation. It mainly due to that the electron trap level (Ni2+/Ni+) promoting the separation of charge carriers and the oxygen vacancies inducing the visible light absorption. In addition, Ni-N-TiO2 shows enhanced activity compared with Ni-TiO2. Codopants and dopants are found to be uniformly distributed in TiO2 matrix. Among the all samples the 0.5% molar quantity of Ni dopant and 500 °C 2 h nitriding condition gives the highest photocatalytic activity. The treatment of ammonia gas on Ni-TiO2 sample induced oxygen vancancies, substitutional and interstitial N. A suitable treatment by ammonia gas also promote separation of charge carriers and the absorption of visible light. The active species generated in the photocatalytic system were also investigated. The strategy presented here gives a promising route towards the development of a metal and non-metal codoped semiconductor materials for applied photocatalysis and related applications.

  1. External compression-induced fracture patterning on the surface of poly(dimethylsiloxane) cubes and microspheres

    PubMed Central

    Uchida, Tomoyuki; Mills, K.L.; Kuo, Chuan-Hsien; Roh, Whijae; Tung, Yi-Chung; Garner, Amanda L.; Koide, Kazunori; Thouless, M.D.; Takayama, Shuichi

    2009-01-01

    This paper describes a method for creating sub-micron surface patterns on cubes and microspheres. In this method, PDMS cubes and microspheres are exposed to oxygen plasma, which creates a very thin, hard, surface-modified layer on a compliant substrate. These are then compressed, causing the layer to crack in patterns dictated by the distribution of tensile stresses in the surface layer. Cracks with sub-micron widths were generated on 1 cm3 cubes and 800 µm-diameter microspheres, and the resulting crack patterns were observed. Finite-element simulations of the tensile stress distributions reveal that the fracture patterns arise from different mechanisms in the cubes and spheres. In particular, pattern formation is associated with frictional contact in the cubes; but not in the microspheres where geometrical effects associated with changes in the cross-sectional area along the axis lead to generation of tensile stress. These observations and analyses provide a foundation on which to predict and guide crack pattern formation on a wide variety of small 3D objects. In anticipation of future applications in materials science and biology, we demonstrate selective deposition of compounds into the cracks to make them functionally differentiable from the rest of the surface. PMID:19437776

  2. PLGA microsphere-mediated growth hormone release hormone expression induces intergenerational growth.

    PubMed

    Ren, Xiao-Hui; Zhang, Yong-Liang; Luo, Hu-Ying; Li, Hong-Yi; Liu, Song-Cai; Zhang, Ming-Jun; Ouyang, Song-Ying; Xi, Qian-Yun; Jiang, Qing-Yan

    2009-01-01

    To improve animal growth, growth hormone-releasing hormone (GHRH) expression vectors that maintain constant GHRH expression can be directly injected into muscles. To deliver the GHRH expression vectors, biodegradable microspheres have been used as a sustained release system. Although administering GHRH through microspheres is a common practice, the intergenerational effects of this delivery system are unknown. To investigate the intergenerational effects of polylactic-co-glycolic acid (PLGA) encapsulated plasmid-mediated GHRH supplements, pCMV-Rep-GHRH microspheres were injected into pregnant mice. Growth and expression of GHRH were measured in the offspring. RT-PCR and immunohistochemistry reveal GHRH expression 3-21 days post-injection. The proportion of GH-positive cells in the GHRH treated offspring was 48.2% higher than in the control group (P < 0.01). The GHRH treated offspring were 6.15% (P < 0.05) larger than the control offspring. At day 49 post-injection, IGF-I serum levels were significantly higher in the treatment group than in the control group. This study confirms that intramuscular expression of GHRH mediated by PLGA microspheres significantly enhances intergenerational growth.

  3. Qing Dai attenuates nonsteroidal anti-inflammatory drug-induced mitochondrial reactive oxygen species in gastrointestinal epithelial cells

    PubMed Central

    Saito, Rie; Tamura, Masato; Matsui, Hirofumi; Nagano, Yumiko; Suzuki, Hideo; Kaneko, Tsuyoshi; Mizokami, Yuji; Hyodo, Ichinosuke

    2015-01-01

    Treatments with nonsteroidal anti-inflammatory drugs (NSAIDs) have increased the number of patients with gastrointestinal complications. Qing Dai has been traditionally used in Chinese herbal medicine for various inflammatory diseases such as ulcerative colitis. We previously reported that Qing Dai suppressed inflammations by scavenging reactive oxygen species (ROS) in ulcerative colitis patients. Thus, Qing Dai can attenuate the production of ROS, which play an important role in NSAID-induced gastrointestinal injuries. In this study, we aimed to elucidate whether Qing Dai decreased mitochondrial ROS production in NSAID-treated gastrointestinal cells by examining cellular injury, mitochondrial membrane potentials, and ROS production with specific fluorescent indicators. We also performed electron paramagnetic resonance measurement in isolated mitochondria with a spin-trapping reagent (CYPMPO or DMPO). Treatments with indomethacin and aspirin induced cellular injury and mitochondrial impairment in the gastrointestinal cells. Under these conditions, mitochondrial alterations were observed on electron microscopy. Qing Dai prevented these complications by suppressing ROS production in gastrointestinal cells. These results indicate that Qing Dai attenuated the ROS production from the NSAID-induced mitochondrial alteration in the gastrointestinal epithelial cells. Qing Dai treatment may be considered effective for the prevention NSAID-induced gastrointestinal injury. PMID:25678747

  4. Manifestations of food protein induced gastrointestinal allergies presenting to a single tertiary paediatric gastroenterology unit

    PubMed Central

    2013-01-01

    Background Food protein induced gastrointestinal allergies are difficult to characterise due to the delayed nature of this allergy and absence of simple diagnostic tests. Diagnosis is based on an allergy focused history which can be challenging and often yields ambiguous results. We therefore set out to describe a group of children with this delayed type allergy, to provide an overview on typical profile, symptoms and management strategies. Methods This retrospective analysis was performed at Great Ormond Street Children’s Hospital. Medical notes were included from 2002 – 2009 where a documented medical diagnosis of food protein induced gastrointestinal allergies was confirmed by an elimination diet with resolution of symptoms, followed by reintroduction with reoccurrence of symptoms. Age of onset of symptoms, diagnosis, current elimination diets and food elimination at time of diagnosis and co-morbidities were collected and parents were phoned again at the time of data collection to ascertain current allergy status. Results Data from 437 children were analysis. The majority (67.7%) of children had an atopic family history and 41.5% had atopic dermatitis at an early age. The most common diagnosis included, non-IgE mediated gastrointestinal food allergy (n = 189) and allergic enterocolitis (n = 154) with symptoms of: vomiting (57.8%), back-arching and screaming (50%), constipation (44.6%), diarrhoea (81%), abdominal pain (89.9%), abdominal bloating (73.9%) and rectal bleeding (38.5%). The majority of patients were initially managed with a milk, soy, egg and wheat free diet (41.7%). At a median age of 8 years, 24.7% of children still required to eliminate some of the food allergens. Conclusions This large retrospective study on children with food induced gastrointestinal allergies highlights the variety of symptoms and treatment modalities used in these children. However, further prospective studies are required in this area of food allergy. PMID:23919257

  5. Microspheres containing neutralizing antibodies to tumor necrosis factor-alpha and interleukin-1 beta protect rats from Staphylococcus aureus-induced peritonitis.

    PubMed

    D'Souza, M; Oettinger, C W; Milton, G V

    2000-10-01

    Previous studies using microencapsulated neutralizing antibodies (NA) to tumor necrosis factor (TNF) and interleukin-1 (IL-1) in combination with gentamicin have demonstrated improved survival in a peritonitis model of gram-negative septic shock. Microencapsulation has been shown to improve the effectiveness of NA by delivering them intracellularly, taking advantage of the natural phagocytic activity of the macrophage. It is the purpose of this study to see if microencapsulated NA to TNF and IL-1 in combination with vancomycin can improve survival compared with NA in solution in Staphlococcus aureus-induced septic shock. Groups of 10 rats received the following treatments: (1) S. aureus plus no treatment, (2) S. aureus plus blank microspheres, (3) S. aureus plus vancomycin, (4) S. aureus plus a microsphere form of NA and vancomycin, (5) S. aureus plus a solution form of NA and vancomycin, (6) S. aureus plus a microsphere form of NA, and (7) S. aureus plus a solution form of NA. Survival was monitored for 5 days, and plasma TNF and IL-1 levels were measured for 48 h after S. aureus administration. All (100%) animals that received the microsphere form of NA plus vancomycin, 20%-70% of the animals that received the microsphere form of NA alone, and 20% of the animals that received antibiotics alone survived for 5 days or more. None of the animals in the no treatment group or blank microsphere treatment group and only 10% of the animals in the solution form of NA plus or minus vancomycin group survived for more than 5 days. Plasma TNF and IL-1 levels were significantly increased after S. aureus treatment. Simultaneous and delayed treatment with the microsphere form of NA plus or minus vancomycin significantly reduced TNF and IL-1 levels, and the solution form of NA significantly reduced only TNF levels after immediate treatment. The survival rate was higher in animals with lower TNF levels and IL-1 levels. The results demonstrate that the microsphere form of cytokine

  6. Facile synthesis of porous magnetite microspheres and solvent-induced phase transition

    NASA Astrophysics Data System (ADS)

    Gan, Zibao; Zhao, Aiwu

    2013-08-01

    Uniform porous magnetite microspheres have been synthesized in a large scale by a dodecyltrimethylammonium bromide (DTAB)-assisted solvothermal route. The as-obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analyzer, Brunauer-Emmett-Teller gas sorptometry and vibrating sample magnetometer. The factors influencing the phase and morphology of the products were investigated. It demonstrates that the ratio of water and ethylene glycol (EG) plays a crucial role for the phase structure and morphology of the products. When the ratio of water and EG does not exceed 1:3, the as-obtained products belong to magnetite phase. Nevertheless, the as-obtained products begin to convert to hematite phase with the ratio increase to 3:5. The reason could be ascribed by the increased water volume, which effectively weakens the reductive activity of EG. Followed by the change of the ratio of water and EG, the morphologies of as-obtained products undergo a series of evolution, such as from flower-like magnetite microspheres to polyhedral hematite nanoplates. On the basis of experimental investigation and analysis, a possible formation mechanism was proposed. The magnetic study demonstrated the porous magnetite microspheres with high saturation magnetization (Ms) and the decreased Ms caused by the phase transition.

  7. Melatonin Attenuates Noise Stress-induced Gastrointestinal Motility Disorder and Gastric Stress Ulcer: Role of Gastrointestinal Hormones and Oxidative Stress in Rats

    PubMed Central

    Zhang, Lei; Gong, Ji T; Zhang, Hu Q; Song, Quan H; Xu, Guang H; Cai, Lei; Tang, Xiao D; Zhang, Hai F; Liu, Fang-E; Jia, Zhan S; Zhang, Hong W

    2015-01-01

    Background/Aims There are increasing evidences for gastrointestinal motility disorder (GIMD) and gastric stress ulcer induced by noise stress. The present study was to investigate the reversed effect of melatonin on GIMD and gastric stress ulcer induced by noise stress and potential mechanism. Methods Noise stress was induced on rats, and melatonin (15 mg/kg) was administered to rats by intraperitoneal injection. Differences were assessed in gastric residual rate (GRR), small intestine propulsion rate (SPR), Guth injury score, cortisol, gastrointestinal hormones (calcitonin-gene-related peptide and motilin) and oxidative stress markers (superoxide dismutase and malondialde hyde) in blood plasma as well as gastric mucosa homogenate with or without melatonin. The pathological examination of gastric mucosa was also performed. Results The GRR and SPR were improved by noise stress compared with control (P < 0.05). The pathological examination and Guth injury score revealed gastric stress ulcer. Moreover, the levels of cortisol, motilin and malondialdehyde in blood plasma and malondialdehyde in gastric mucosa homogenate were increased by noise stress (P < 0.05). CGRP and superoxide dismutase activity in both of blood plasma and gastric mucosa homogenate were significantly decreased (P< 0.05). Furthermore, melatonin reversed changes in GRR, SPR, pathological examination, Guth injury score, cortisol, motilin, CGRP, superoxide dismutase activity and malondialdehyde (P < 0.05). Conclusions Melatonin is effective in reversing the GIMD and gastric stress ulcer induced by noise stress. The underlying mechanism may be involved in oxidative stress and gastrointestinal hormones. PMID:25537679

  8. Polyacrolein microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1987-01-01

    Microspheres of acrolein homopolymers and copolymer with hydrophillic comonomers such as methacrylic acid and/or hydroxyethylmethacrylate are prepared by cobalt gamma irradiation of dilute aqueous solutions of the monomers in presence of suspending agents, especially alkyl sulfates such as sodium dodecyl sulfate. Amine or hydroxyl modification is achieved by forming adducts with diamines or alkanol amines. Carboxyl modification is effected by oxidation with peroxides. Pharmaceuticals or other aldehyde reactive materials can be coupled to the microspheres. The microspheres directly form antibody adducts without agglomeration.

  9. Polyacrolein microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1986-01-01

    Microspheres of acrolein homopolymers and copolymer with hydrophillic comonomers such as methacrylic acid and/or hydroxyethylmethacrylate are prepared by cobalt gamma irradiation of dilute aqueous solutions of the monomers in presence of suspending agents, especially alkyl sulfates such as sodium dodecyl sulfate. Amine or hydroxyl modification is achieved by forming adducts with diamines or alkanol amines. Carboxyl modification is effected by oxidation with peroxides. Pharmaceuticals or other aldehyde reactive materials can be coupled to the microspheres. The microspheres directly form antibody adducts without agglomeration.

  10. Polyacrolein microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1983-01-01

    Microspheres of acrolein homopolymers and co-polymer with hydrophillic comonomers such as methacrylic acid and/or hydroxyethylmethacrylate are prepared by cobalt gamma irradiation of dilute aqueous solutions of the monomers in presence of suspending agents, especially alkyl sulfates such as sodium dodecyl sulfate. Amine or hydroxyl modification is achieved by forming adducts with diamines or alkanol amines. Carboxyl modification is effected by oxidation with peroxides. Pharmaceuticals or other aldehyde reactive materials can be coupled to the microspheres. The microspheres directly form antibody adducts without agglomeration.

  11. Mass-Transfer-Induced Multistep Phase Separation in Emulsion Droplets: Toward Self-Assembly Multilayered Emulsions and Onionlike Microspheres.

    PubMed

    Liang, Shuaishuai; Li, Jiang; Man, Jia; Chen, Haosheng

    2016-08-01

    Mass-transfer-induced multistep phase separation was found in emulsion droplets. The agent system consists of a monomer (ethoxylated trimethylolpropane triacrylate, ETPTA), an oligomer (polyethylene glycol diacrylate, PEGDA 700), and water. The PEGDA in the separated layers offered partial miscibility of all the components throughout the multistep phase-separation procedure, which was terminated by the depletion of PEGDA in the outermost layer. The number of separated portions was determined by the initial PEGDA content, and the initial droplet size influenced the mass-transfer process and consequently determined the sizes of the separated layers. The resultant multilayered emulsions were demonstrated to offer an orderly temperature-responsive release of the inner cores. Moreover, the emulsion droplets can be readily solidified into onionlike microspheres by ultraviolet light curing, providing a new strategy in designing particle structures.

  12. Mass-Transfer-Induced Multistep Phase Separation in Emulsion Droplets: Toward Self-Assembly Multilayered Emulsions and Onionlike Microspheres.

    PubMed

    Liang, Shuaishuai; Li, Jiang; Man, Jia; Chen, Haosheng

    2016-08-01

    Mass-transfer-induced multistep phase separation was found in emulsion droplets. The agent system consists of a monomer (ethoxylated trimethylolpropane triacrylate, ETPTA), an oligomer (polyethylene glycol diacrylate, PEGDA 700), and water. The PEGDA in the separated layers offered partial miscibility of all the components throughout the multistep phase-separation procedure, which was terminated by the depletion of PEGDA in the outermost layer. The number of separated portions was determined by the initial PEGDA content, and the initial droplet size influenced the mass-transfer process and consequently determined the sizes of the separated layers. The resultant multilayered emulsions were demonstrated to offer an orderly temperature-responsive release of the inner cores. Moreover, the emulsion droplets can be readily solidified into onionlike microspheres by ultraviolet light curing, providing a new strategy in designing particle structures. PMID:27427849

  13. Prevention of acrylonitrile-induced gastrointestinal bleeding by sulfhydryl compounds, atropine and cimetidine

    SciTech Connect

    Ghanayem, B.I.; Ahmed, A.E.

    1986-07-01

    We have recently demonstrated that acrylonitrile (VCN) causes acute gastric hemorrhage and mucosal erosions. The current studies were undertaken to investigate the effects of the sulfhydryl-containing compounds, cysteine and cysteamine, the cholinergic blocking agent atropine and the histamine H2 receptor antagonist, cimetidine on the VCN-induced gastrointestinal (GI) bleeding in rats. Our data shows that pretreatment with L-cysteine, cysteamine, atropine or cimetidine has significantly protected rats against the VCN-induced GI bleeding. A possible mechanism of the VCN-induced GI bleeding may involve the interaction of VCN with critical sulfhydryl groups that, in turn, causes alteration of acetylcholine muscarinic receptors to lead to gastric hemorrhagic lesions and bleeding.

  14. Antiobese effects of capsaicin-chitosan microsphere (CCMS) in obese rats induced by high fat diet.

    PubMed

    Tan, Sirong; Gao, Bing; Tao, Yi; Guo, Jiao; Su, Zheng-quan

    2014-02-26

    Chitosan (CTS) and capsaicin (CAP) are two kinds of effective ingredients for antiobesity, which are extracted from crab shells and Capsicum annuum. However, the strong taste of CAP makes it difficult to consume, and the antiobesity ability of CTS is limited. In this study, we prepared capsaicin-chitosan microspheres (CCMSs) by ion-cross-linking and spray drying and examined the antiobesity ability of CCMSs in obese rats. The effects of CCMSs on body weight, Lee's index, body fat, and serum lipids were investigated. The mRNA expression of PPARα, PPARγ, leptin, UCP2, GPR120, FTO, and adiponectin in the liver was determined by quantitative real-time PCR, and the protein expression of adiponectin, leptin, PPARα, UCP2, and hepatic lipase in serum was evaluated by enzyme-linked immunosorbent assay. CCMSs were prepared with 85.17% entrapment efficiency and 8.87% mean drug loading. Compared with chitosan microspheres, CAP, and Orlistat, the CCMSs showed better ability to control body weight, body mass index, organ index, body fat, proportion of fat to body weight, and serum lipids. The CCMSs upregulated the expressions of PPARα, PPARγ, UCP2, and adiponectin and downregulated the expression of leptin. CCMSs may thus be considered novel, safe, effective, and natural weight loss substances, and there is an additive effect between CTMS and capsaicin.

  15. Molecular cloning of motilin and mechanism of motilin-induced gastrointestinal motility in Japanese quail.

    PubMed

    Apu, Auvijit Saha; Mondal, Anupom; Kitazawa, Takio; Takemi, Shota; Sakai, Takafumi; Sakata, Ichiro

    2016-07-01

    Motilin, a peptide hormone produced in the upper intestinal mucosa, plays an important role in the regulation of gastrointestinal (GI) motility. In the present study, we first determined the cDNA and amino acid sequences of motilin in the Japanese quail and studied the distribution of motilin-producing cells in the gastrointestinal tract. We also examined the motilin-induced contractile properties of quail GI tracts using an in vitro organ bath, and then elucidated the mechanisms of motilin-induced contraction in the proventriculus and duodenum of the quail. Mature quail motilin was composed of 22 amino acid residues, which showed high homology with chicken (95.4%), human (72.7%), and dog (72.7%) motilin. Immunohistochemical analysis showed that motilin-immunopositive cells were present in the mucosal layer of the duodenum (23.4±4.6cells/mm(2)), jejunum (15.2±0.8cells/mm(2)), and ileum (2.5±0.7cells/mm(2)), but were not observed in the crop, proventriculus, and colon. In the organ bath study, chicken motilin induced dose-dependent contraction in the proventriculus and small intestine. On the other hand, chicken ghrelin had no effect on contraction in the GI tract. Motilin-induced contraction in the duodenum was not inhibited by atropine, hexamethonium, ritanserin, ondansetron, or tetrodotoxin. However, motilin-induced contractions in the proventriculus were significantly inhibited by atropine and tetrodotoxin. These results suggest that motilin is the major stimulant of GI contraction in quail, as it is in mammals and the site of action of motilin is different between small intestine and proventriculus. PMID:27179882

  16. Molecular cloning of motilin and mechanism of motilin-induced gastrointestinal motility in Japanese quail.

    PubMed

    Apu, Auvijit Saha; Mondal, Anupom; Kitazawa, Takio; Takemi, Shota; Sakai, Takafumi; Sakata, Ichiro

    2016-07-01

    Motilin, a peptide hormone produced in the upper intestinal mucosa, plays an important role in the regulation of gastrointestinal (GI) motility. In the present study, we first determined the cDNA and amino acid sequences of motilin in the Japanese quail and studied the distribution of motilin-producing cells in the gastrointestinal tract. We also examined the motilin-induced contractile properties of quail GI tracts using an in vitro organ bath, and then elucidated the mechanisms of motilin-induced contraction in the proventriculus and duodenum of the quail. Mature quail motilin was composed of 22 amino acid residues, which showed high homology with chicken (95.4%), human (72.7%), and dog (72.7%) motilin. Immunohistochemical analysis showed that motilin-immunopositive cells were present in the mucosal layer of the duodenum (23.4±4.6cells/mm(2)), jejunum (15.2±0.8cells/mm(2)), and ileum (2.5±0.7cells/mm(2)), but were not observed in the crop, proventriculus, and colon. In the organ bath study, chicken motilin induced dose-dependent contraction in the proventriculus and small intestine. On the other hand, chicken ghrelin had no effect on contraction in the GI tract. Motilin-induced contraction in the duodenum was not inhibited by atropine, hexamethonium, ritanserin, ondansetron, or tetrodotoxin. However, motilin-induced contractions in the proventriculus were significantly inhibited by atropine and tetrodotoxin. These results suggest that motilin is the major stimulant of GI contraction in quail, as it is in mammals and the site of action of motilin is different between small intestine and proventriculus.

  17. [Low-dose aspirin (LDA)/nonsteroidal anti-inflammatory drugs(NSAIDs)-induced gastrointestinal injury in Japan].

    PubMed

    Sugano, Kentaro

    2011-06-01

    Low-dose aspirin (LDA) and nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed in Japan mostly due to increasing elderly population. Since LDA/NSAIDs cause gastrointestinal injury, serious side effects such as bleeding accompanied with their usage have been frequently reported. Awareness of such problems prompted clinical trials to facilitate a more effective approach to prevent LDA/NSAIDs-induced gastrointestinal ulcer. Two drugs recently approved for health insurance reimbursement, celecoxib, a cyclooxygenase (COX)-2 specific inhibitor and low-dose lansoprazole for prevention of recurrent peptic ulcer due to LDA/NSAIDs will be instrumental in mitigating the gastrointestinal injuries. However, continuous, intensive educational programs will be required to the change in the prescription behaviors of the general physicians. Furthermore, we need to search for effective measures to detect and prevent mid and lower gastrointestinal injury caused by LDA/NSAIDs which account for about 30% of all GI bleedings.

  18. Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

    SciTech Connect

    Li, Jun; Sun, Kang; Ni, Lijuan; Wang, Xufang; Wang, Dongxu; Zhang, Jinsong

    2012-02-01

    Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

  19. Mucoadhesive Microspheres Containing Amoxicillin for Clearance of Helicobacter pylori

    PubMed Central

    Nagahara, Naoki; Akiyama, Yohko; Nakao, Masafumi; Tada, Mayumi; Kitano, Megumi; Ogawa, Yasuyuki

    1998-01-01

    In an effort to augment the anti-Helicobacter pylori effect of amoxicillin, mucoadhesive microspheres, which have the ability to reside in the gastrointestinal tract for an extended period, were prepared. The microspheres contained the antimicrobial agent and an adhesive polymer (carboxyvinyl polymer) powder dispersed in waxy hydrogenated castor oil. The percentage of amoxicillin remaining in the stomach both 2 and 4 h after oral administration of the mucoadhesive microspheres to Mongolian gerbils under fed conditions was about three times higher than that after administration in the form of a 0.5% methylcellulose suspension. The in vivo clearance of H. pylori following oral administration of the mucoadhesive microspheres and the 0.5% methylcellulose suspension to infected Mongolian gerbils was examined under fed conditions. The mucoadhesive microspheres and the 0.5% methylcellulose suspension both showed anti-H. pylori effects in this experimental model of infection, but the required dose of amoxicillin was effectively reduced by a factor of 10 when the mucoadhesive microspheres were used. In conclusion, the mucoadhesive microspheres more effectively cleared H. pylori from the gastrointestinal tract than the 0.5% methylcellulose suspension due to the prolonged gastrointestinal residence time resulting from mucoadhesion. A dosage form consisting of mucoadhesive microspheres containing an appropriate antimicrobial agent should be useful for the eradication of H. pylori. PMID:9756746

  20. Acute Pancreatitis and Gastroduodenal Intussusception Induced by an Underlying Gastric Gastrointestinal Stromal Tumor: A Case Report

    PubMed Central

    Doğan, Ahmet; Koparan, Ibrahim Halil; Adin, Mehmet Emin

    2016-01-01

    Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal system and comprise only 1% to 3% of all gastrointestinal tract tumors, with the majority of them arising in the stomach. In this report, we present the unique findings of a case of gastroduodenal intussusception caused by an underlying gastric GIST and complicated with severe acute pancreatitis. PMID:27104028

  1. Multiple Resonances Induced by Plasmonic Coupling between Gold Nanoparticle Trimers and Hexagonal Assembly of Gold-Coated Polystyrene Microspheres.

    PubMed

    Uchida, Takako; Yoshikawa, Takayasu; Tamura, Mamoru; Iida, Takuya; Imura, Kohei

    2016-09-15

    Optical properties of a gold nanoparticle trimer assembly coupled with gold-coated hexagonally close-packed polystyrene microspheres were investigated by linear and nonlinear spectroscopy. The observed reflection spectrum shows multiple peaks from the visible to near-infrared spectral regions. The spectroscopic properties were also examined by a finite-difference time-domain simulation. We found that the optical response of plasmons excited in the gold nanoparticle trimers was significantly modulated by strong coupling of the plasmons and the photonic mode induced in the gold-coated polystyrene assembly. Two-photon induced photoluminescence and Raman scattering from the sample were investigated, and both signals were significantly enhanced at the gold nanoparticle assembly. The simulations reveal that the electric fields can be enhanced site-selectively, not only at the interstitial sites in the nanoparticle assembly but also at the gaps between the particle and the gold film due to plasmonic interactions, by tuning the wavelength and are responsible for the strong optical responses.

  2. Multiple Resonances Induced by Plasmonic Coupling between Gold Nanoparticle Trimers and Hexagonal Assembly of Gold-Coated Polystyrene Microspheres.

    PubMed

    Uchida, Takako; Yoshikawa, Takayasu; Tamura, Mamoru; Iida, Takuya; Imura, Kohei

    2016-09-15

    Optical properties of a gold nanoparticle trimer assembly coupled with gold-coated hexagonally close-packed polystyrene microspheres were investigated by linear and nonlinear spectroscopy. The observed reflection spectrum shows multiple peaks from the visible to near-infrared spectral regions. The spectroscopic properties were also examined by a finite-difference time-domain simulation. We found that the optical response of plasmons excited in the gold nanoparticle trimers was significantly modulated by strong coupling of the plasmons and the photonic mode induced in the gold-coated polystyrene assembly. Two-photon induced photoluminescence and Raman scattering from the sample were investigated, and both signals were significantly enhanced at the gold nanoparticle assembly. The simulations reveal that the electric fields can be enhanced site-selectively, not only at the interstitial sites in the nanoparticle assembly but also at the gaps between the particle and the gold film due to plasmonic interactions, by tuning the wavelength and are responsible for the strong optical responses. PMID:27596630

  3. Blockade of TLR3 protects mice from lethal radiation-induced gastrointestinal syndrome

    PubMed Central

    Takemura, Naoki; Kawasaki, Takumi; Kunisawa, Jun; Sato, Shintaro; Lamichhane, Aayam; Kobiyama, Kouji; Aoshi, Taiki; Ito, Junichi; Mizuguchi, Kenji; Karuppuchamy, Thangaraj; Matsunaga, Kouta; Miyatake, Shoichiro; Mori, Nobuko; Tsujimura, Tohru; Satoh, Takashi; Kumagai, Yutaro; Kawai, Taro; Standley, Daron M.; Ishii, Ken J.; Kiyono, Hiroshi; Akira, Shizuo; Uematsu, Satoshi

    2014-01-01

    High-dose ionizing radiation induces severe DNA damage in the epithelial stem cells in small intestinal crypts and causes gastrointestinal syndrome (GIS). Although the tumour suppressor p53 is a primary factor inducing death of crypt cells with DNA damage, its essential role in maintaining genome stability means inhibiting p53 to prevent GIS is not a viable strategy. Here we show that the innate immune receptor Toll-like receptor 3 (TLR3) is critical for the pathogenesis of GIS. Tlr3−/− mice show substantial resistance to GIS owing to significantly reduced radiation-induced crypt cell death. Despite showing reduced crypt cell death, p53-dependent crypt cell death is not impaired in Tlr3−/− mice. p53-dependent crypt cell death causes leakage of cellular RNA, which induces extensive cell death via TLR3. An inhibitor of TLR3–RNA binding ameliorates GIS by reducing crypt cell death. Thus, we propose blocking TLR3 activation as a novel approach to treat GIS. PMID:24637670

  4. Changes of gastrointestinal argyrophil endocrine cells in the osteoporotic SD rats induced by ovariectomy.

    PubMed

    Ku, Sae Kwang; Lee, Hyeung Sik; Lee, Jae Hyun

    2004-09-01

    The regional distributions and frequencies of argyrophil endocrine cells in gastrointestinal (GI) tract of osteoporotic Sprague-Dawley rat induced by ovariectomy were studied using Grimelius silver stain. The experimental animals were divided into two groups, one is non-ovariectomized group (Sham) and the other is ovariectomized group (OVX). Samples were collected from each part of GI tract (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) at 10th week after ovariectomy or sham operation. In this study, argyrophil cells were detected throughout the entire GI tract with various frequencies regardless of ovariectomy. Most of these argyrophil cells in the mucosa of GI tract were generally spherical or spindle in shape (open type cell) while cells showing round in shape (close type cell) were found occasionally in gastric and/or intestinal gland regions. The regional distributions of GI argyrophil endocrine cells in OVX were similar to those of Sham. However, significant decreases of argyrophil cells were detected in OVX compared to those of Sham except for the pylorus, jejunum and cecum. In pylorus and jejunum, argyrophil cells in OVX dramatically decreased compared to those of Sham but significances were not recorded. In addition, argyrophil cells in cecum of OVX showed similar frequency compared to that of Sham. The endocrine cells are the anatomical units responsible for the production of gut hormones that regulate gut motility and digestion including absorption, and a change in their density would reflect the change in the capacity of producing these hormones and regulating gut motility and digestion. Ovariectomy induced severe quantitative changes of GI argyrophil endocrine cell density, and the abnormality in density of GI endocrine cells may contribute to the development of gastrointestinal symptoms in osteoporosis such as impairments of calcium and some lipids, frequently encountered in patients with postmenopausal osteoporosis. PMID

  5. Gastrointestinal Symptoms and Altered Intestinal Permeability Induced by Combat Training Are Associated with Distinct Metabotypic Changes.

    PubMed

    Phua, Lee Cheng; Wilder-Smith, Clive H; Tan, Yee Min; Gopalakrishnan, Theebarina; Wong, Reuben K; Li, Xinhua; Kan, Mary E; Lu, Jia; Keshavarzian, Ali; Chan, Eric Chun Yong

    2015-11-01

    Physical and psychological stress have been shown to modulate multiple aspects of gastrointestinal (GI) physiology, but its molecular basis remains elusive. We therefore characterized the stress-induced metabolic phenotype (metabotype) in soldiers during high-intensity combat training and correlated the metabotype with changes in GI symptoms and permeability. In a prospective, longitudinal study, urinary metabotyping was conducted on 38 male healthy soldiers during combat training and a rest period using gas chromatography-mass spectrometry. The urinary metabotype during combat training was clearly distinct from the rest period (partial least-squares discriminant analysis (PLSDA) Q(2) = 0.581), confirming the presence of a unique stress-induced metabotype. Differential metabolites related to combat stress were further uncovered, including elevated pyroglutamate and fructose, and reduced gut microbial metabolites, namely, hippurate and m-hydroxyphenylacetate (p < 0.05). The extent of pyroglutamate upregulation exhibited a positive correlation with an increase in IBS-SSS in soldiers during combat training (r = 0.5, p < 0.05). Additionally, the rise in fructose levels was positively correlated with an increase in intestinal permeability (r = 0.6, p < 0.005). In summary, protracted and mixed psychological and physical combat-training stress yielded unique metabolic changes that corresponded with the incidence and severity of GI symptoms and alteration in intestinal permeability. Our study provided novel molecular insights into stress-induced GI perturbations, which could be exploited for future biomarker research or development of therapeutic strategies. PMID:26506213

  6. Glass microspheres

    SciTech Connect

    Day, D.E.; Ehrhardt, G.J.

    1988-12-06

    This patent describes a glass microsphere having a diameter of about 54 micrometers or less and adapted for radiation therapy of a mammal. The glass consists of essentially an yttrium oxide-aluminosilicate glass composition lying substantially within a quadrilateral region of the ternary composition diagram of the yttria-alumina-silica system, the quadrilateral region being defined by its four corners having the following combination of weight proportions of the components: 20% silica, 10% alumina, 70% yttria; 70% silica, 10% alumina, 20% yttria; 70% silica, 20% alumina, 10% yttria; and 20% silica, 45% alumina, 35% yttria, the glass having a chemical durability such that subsequent to irradiation and administration of the microsphere to the mammal, the mircosphere will not release a significant amount of yttrium-90 into the mammal's system.

  7. Lung dendritic cells induce migration of protective T cells to the gastrointestinal tract

    PubMed Central

    Ruane, Darren; Brane, Lucas; Reis, Bernardo Sgarbi; Cheong, Cheolho; Poles, Jordan; Do, Yoonkyung; Zhu, Hongfa; Velinzon, Klara; Choi, Jae-Hoon; Studt, Natalie; Mayer, Lloyd; Lavelle, Ed C.; Steinman, Ralph M.; Mucida, Daniel

    2013-01-01

    Developing efficacious vaccines against enteric diseases is a global challenge that requires a better understanding of cellular recruitment dynamics at the mucosal surfaces. The current paradigm of T cell homing to the gastrointestinal (GI) tract involves the induction of α4β7 and CCR9 by Peyer’s patch and mesenteric lymph node (MLN) dendritic cells (DCs) in a retinoic acid–dependent manner. This paradigm, however, cannot be reconciled with reports of GI T cell responses after intranasal (i.n.) delivery of antigens that do not directly target the GI lymphoid tissue. To explore alternative pathways of cellular migration, we have investigated the ability of DCs from mucosal and nonmucosal tissues to recruit lymphocytes to the GI tract. Unexpectedly, we found that lung DCs, like CD103+ MLN DCs, up-regulate the gut-homing integrin α4β7 in vitro and in vivo, and induce T cell migration to the GI tract in vivo. Consistent with a role for this pathway in generating mucosal immune responses, lung DC targeting by i.n. immunization induced protective immunity against enteric challenge with a highly pathogenic strain of Salmonella. The present report demonstrates novel functional evidence of mucosal cross talk mediated by DCs, which has the potential to inform the design of novel vaccines against mucosal pathogens. PMID:23960190

  8. Effects of acute and chronic STZ-induced diabetes on clock gene expression and feeding in the gastrointestinal tract.

    PubMed

    Bostwick, Jonathon; Nguyen, Diane; Cornélissen, Germaine; Halberg, Franz; Hoogerwerf, Willemijntje A

    2010-05-01

    Diabetes may shift clock gene expression within peripheral organs. However, little is known about the effect of diabetes on the gastrointestinal molecular clock. We therefore investigated the effect of diabetes on gastrointestinal clock gene expression. As peripheral clock gene expression is strongly driven by food intake, we also determined the effect of STZ-induced diabetes on patterns of food intake. The effects of acute (1 week) and chronic (12 weeks) STZ-induced diabetes on period (per) genes in the stomach body, proximal and distal colon, liver, kidney, and lung of C57BL/6J mice were assessed using real-time polymerase chain reaction. Food intake studies were completed using automated feeding equipment. Rhythmicity in expression of per2 and per3 persisted in all organs. However, per2 and per3 expression of STZ-injected mice was generally phase delayed within the gastrointestinal tract but not within the kidney or lung as compared with vehicle-injected mice. The phase delay was most pronounced for per2 in the proximal colon at 12 weeks. Food intake was rhythmic with larger circadian amplitude for diabetic mice than for control mice. Thus, STZ-induced diabetes differentially alters peripheral per expression. STZ-induced diabetes does not alter the circadian phase of food intake. Alterations in clock gene expression in a mouse model of diabetes are most pronounced in those organs that are intimately associated with food processing and metabolism. PMID:20091094

  9. Microradiographic microsphere manipulator

    DOEpatents

    Singleton, R.M.

    A method and apparatus is disclosed for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres.

  10. Microradiographic microsphere manipulator

    DOEpatents

    Singleton, Russell M.

    1980-01-01

    A method and apparatus for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated to relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres.

  11. Protective effect of dimethylsulphoxide in stress- and indometacin-induced gastrointestinal ulceration in rats.

    PubMed

    Ali, B H

    1989-01-01

    The protective effect of dimethylsulphoxide (DMSO) against stress- and indometacin-induced gastrointestinal ulcers was assessed in rats. It was found that stress (restraint at 4 degrees C for 3 h) produced mucosal lesions in the stomach antrum and corpus, and the small intestine. DMSO given in the drinking water at concentrations of 1, 2, 4 or 6% (v/v) 7 days before the application of stress produced dose-dependent decreases in both the number of ulcers and the ulcer index (UI). These decreases were significant at doses of 4 and 6% (v/v). Indometacin was effective in producing ulcers in the gastric antrum and small intestine, but not in the corpus of the stomach, when it was given to rats fasted for 24 h and fed for 1 h before drug administration. Again, pretreatment with DMSO, at doses of 4 and 6% (v/v) for 7 days was effective in reducing significantly the number of ulcers and the UI in the indometacin-treated rats. At all doses of DMSO there were no significant changes in the haemogram or in the histological (light microscopic) picture of the organs examined. A small reduction (6%) in the body weight was observed in rats on the higher dose of DMSO, probably due to decreased feed intake (10%) in this group. Further pharmacological and toxicological studies on DMSO seem warranted.

  12. Con-A conjugated mucoadhesive microspheres for the colonic delivery of diloxanide furoate.

    PubMed

    Anande, Nalini M; Jain, Sunil K; Jain, Narendra K

    2008-07-01

    The aim of the research work was to develop cyst-targeted novel concanavalin-A (Con-A) conjugated mucoadhesive microspheres of diloxanide furoate (DF) for the effective treatment of amoebiasis. Eudragit microspheres of DF were prepared using emulsification-solvent evaporation method. Formulations were characterized for particle size and size distribution, % drug entrapment, surface morphology and in vitro drug release in simulated gastrointestinal (GI) fluids. Eudragit microspheres of DF were conjugated with Con-A. IR spectroscopy and DSC were used to confirm successful conjugation of Con-A to Eudragit microspheres while Con-A conjugated microspheres were further characterized using the parameters of zeta potential, mucoadhesiveness to colonic mucosa and Con-A conjugation efficiency with microspheres. IR studies confirmed the attachment of Con-A with Eudragit microspheres. All the microsphere formulations showed good % drug entrapment (78+/-5%). Zeta potential of Eudragit microspheres and Con-A conjugated Eudragit microspheres were found to be 3.12+/-0.7mV and 16.12+/-0.5mV, respectively. Attachment of lectin to the Eudragit microspheres significantly increases the mucoadhesiveness and also controls the release of DF in simulated GI fluids. Gamma scintigraphy study suggested that Eudragit S100 coated gelatin capsule retarded the release of Con-A conjugated microspheres at low pH and released microspheres slowly at pH 7.4 in the colon.

  13. Hybrid microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Richard C. K. (Inventor)

    1985-01-01

    Substrates, particularly inert synthetic organic resin beads (10) or sheet (12) such as polystyrene are coated with a covalently bound layer (24) of polyacrolein by irradiation a solution (14) of acrolein or other aldehyde with high intensity radiation. Individual microspheres (22) are formed which attach to the surface to form the aldehyde containing layer (24). The aldehyde groups can be converted to other functional groups by reaction with materials such as hydroxylamine. Adducts of proteins such as antibodies or enzymes can be formed by direct reaction with the surface aldehyde groups.

  14. Balancing opioid-induced gastrointestinal side effects with pain management: Insights from the online community.

    PubMed

    Whitman, Cynthia B; Reid, Mark W; Arnold, Corey; Patel, Haridarshan; Ursos, Lyann; Sa'adon, Roee; Pourmorady, Jonathan; Spiegel, Brennan M R

    2015-01-01

    Opioids cause gastrointestinal (GI) symptoms such as nausea, vomiting, pain, and (in 40 percent) constipation that diminish patients' quality of life. Outside traditional surveys, little is known about the opioid-induced constipation (OIC) patient experience and its impact on pain management. The purpose of this study was to use data from social media platforms to qualitatively examine patient beliefs about OIC and other prominent GI side effects, their impact on effective pain management and doctor-patient interaction. The authors collected Tweets from March 25 to July 31, 2014, and e-forum posts from health-related social networking sites regardless of timestamp. The authors identified specific keywords related to opioids and GI side effects to locate relevant content in the dataset, which was then manually coded using ATLAS.ti software. The authors examined 2,519,868 Tweets and more than 1.8 billion e-forum posts, of which, 88,586 Tweets and 9,767 posts satisfied the search criteria. Three thousand three individuals experienced opioidinduced GI side effects, mostly related to phenanthrenes (n = 1,589), and 1,274 (42.4 percent) individuals described constipation. Over-the-counter medications and nonevidence-based natural approaches were most commonly used to alleviate constipation. Many individuals questioned, rotated, reduced, or stopped their opioid treatments as a result of their GI side effects. Investigation of social media reveals a struggle to balance pain management with opioid-induced GI side effects, especially constipation. Individuals are often unprepared to treat OIC, to modify opioid regiments without medical advice, and to resort to using natural remedies and treatments lacking scientific evidence of effectiveness. These results identify opportunities to improve physician-patient communication and explore effective treatment alternatives. PMID:26535966

  15. Lactose maldigestion during methotrexate-induced gastrointestinal mucositis in a rat model.

    PubMed

    Fijlstra, M; Rings, E H H M; Verkade, H J; van Dijk, T H; Kamps, W A; Tissing, W J E

    2011-02-01

    Patients with chemotherapy-induced gastrointestinal mucositis suffer from anorexia, diarrhea, and stomach pain, often causing weight loss and malnutrition. When the intestinal function during mucositis would be known, a rational feeding strategy might improve the nutritional state, accelerate recuperation, and increase survival of mucositis patients. We developed a methotrexate (MTX)-induced mucositis rat model to study nutrient digestion and absorption. To determine lactose digestion and absorption of its derivative glucose during mucositis, we injected Wistar rats intravenously with MTX (60 mg/kg) or 0.9% NaCl (controls). Four days later, we orally administered trace amounts of [1-(13)C]lactose and [U-(13)C]glucose and quantified the appearance of labeled glucose in the blood for 3 h. Finally, we determined plasma citrulline level and harvested the small intestine to assess histology, myeloperoxidase level, glycohydrolase activity, immunohistochemical protein, and mRNA expression. MTX-treated rats showed profound villus atrophy and epithelial damage. During the experimental period, the absorption of lactose-derived [1-(13)C]glucose was 4.2-fold decreased in MTX-treated rats compared with controls (P < 0.01). Lactose-derived [1-(13)C]glucose absorption correlated strongly with villus length (rho = 0.86, P < 0.001) and with plasma citrulline level (rho = 0.81, P < 0.001). MTX treatment decreased jejunal lactase activity (19.5-fold, P < 0.01) and immunohistochemical protein and mRNA expression (39.7-fold, P < 0.01) compared with controls. Interestingly, MTX treatment did not affect the absorption of [U-(13)C]glucose during the experimental period. We conclude that lactose digestion is severely decreased during mucositis while glucose absorption is still intact, when supplied in trace amounts. Plasma citrulline level might be a useful objective, noninvasive marker for lactose maldigestion during mucositis in clinic.

  16. Microstructured microspheres of hydroxyapatite bioceramic.

    PubMed

    Sunny, M C; Ramesh, P; Varma, H K

    2002-07-01

    Hydroxyapatite (HAP) particles having spherical geometry and 125-1000 microm in size range were prepared using a solid-in-water-in-oil (S/W/O) emulsion, cross-linking technique. An aqueous solution of chitosan containing different loading of HAP was dispersed as droplet in liquid paraffin using a stabilizing agent. Cross-linking of chitosan was induced by adding appropriate amount of glutaraldehyde saturated toluene. Chitosan microspheres containing HAP were sintered at 1150 degrees C to obtain pure HAP microspheres. The spheres thus produced were examined by scanning electron microscopy. The percentage yield and size distributions of the spheres were also determined.

  17. The Role of Oxidative Stress in Gastrointestinal Tract Tissues Induced by Arsenic Toxicity in Cocks.

    PubMed

    Guo, Ying; Zhao, Panpan; Guo, Guangyang; Hu, Zhibo; Tian, Li; Zhang, Kexin; Zhang, Wen; Xing, Mingwei

    2015-12-01

    Arsenic (As) is a widely distributed trace element which is known to be associated with numerous adverse effects on human beings and animals. Arsenic trioxide (As2O3) is an inorganic arsenical-containing toxic compound. The effect of excessive amounts of As2O3 exposure on gastrointestinal tract tissue damage in cocks is still unknown. This study was conducted to investigate the effect of As2O3 exposure on gastrointestinal tract tissue damage in cocks. In total, 72 1-day-old male Hyline cocks were randomly divided into four groups and fed either a commercial diet or an As2O3 supplement diet containing 7.5, 15, and 30 mg/kg As2O3. The experiment lasted for 90 days and gastrointestinal tract tissue samples (gizzard, glandular stomach, duodenum, jejunum, ileum, cecum, and rectum) were collected at 30, 60, and 90 days. Catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px) activities; malondialdehyde (MDA) contents; and hydroxyl radical (OH·)-mediated inhibition were examined. Furthermore, the results demonstrated that MDA content in the gastrointestinal tract was increased, while the activities of CAT, GSH, and GSH-Px and the ability to resist OH· was decreased in the As2O3 treatment groups. Extensive damage was observed in the gastrointestinal tract. These findings indicated that As2O3 exposure caused oxidative damage in the gastrointestinal tract of cocks due to alterations in antioxidant enzyme activities and elevation of free radicals.

  18. Kinetics of piroxicam release from low-methylated pectin/zein hydrogel microspheres

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The kinetics of a model drug (piroxicam) release from pectin/zein hydrogel microspheres was studied under conditions simulating the gastrointestinal tract. It is established that the rate-limiting step in the release mechanism is drug diffusion out of the microspheres rather than its dissolution. ...

  19. Ex vivo optical coherence tomography and laser induced fluorescence spectroscopy imaging of murine gastrointestinal tract

    NASA Astrophysics Data System (ADS)

    Hariri, Lida; Tumlinson, Alexandre R.; Wade, Norman; Besselsen, David; Utzinger, Urs; Gerner, Eugene; Barton, Jennifer

    2005-04-01

    Optical Coherence Tomography (OCT) and Laser Induced Fluorescence Spectroscopy (LIF) have separately been found to have clinical potential in identifying human gastrointestinal (GI) pathologies, yet their diagnostic capability in mouse models of human disease is unknown. We combine the two modalities to survey the GI tract of a variety of mouse strains and sample dysplasias and inflammatory bowel disease (IBD) of the small and large intestine. Segments of duodenum and lower colon 2.5 cm in length and the entire esophagus from 10 mice each of two colon cancer models (ApcMin and AOM treated A/J) and two IBD models (Il-2 and Il-10) and 5 mice each of their respective controls were excised. OCT images and LIF spectra were obtained simultaneously from each tissue sample within 1 hour of extraction. Histology was used to classify tissue regions as normal, Peyer"s patch, dysplasia, adenoma, or IBD. Features in corresponding regions of OCT images were analyzed. Spectra from each of these categories were averaged and compared via the student's t-test. Features in OCT images correlated to histology in both normal and diseased tissue samples. In the diseased samples, OCT was able to identify early stages of mild colitis and dysplasia. In the sample of IBD, the LIF spectra displayed unique peaks at 635nm and 670nm, which were attributed to increased porphyrin production in the proliferating bacteria of the disease. These peaks have the potential to act as a diagnostic for IBD. OCT and LIF appear to be useful and complementary modalities for imaging mouse models.

  20. Detection of Treatment-Induced Changes in Signaling Pathways in Gastrointestinal Stromal Tumors using Transcriptomic Data

    PubMed Central

    Ochs, Michael F.; Rink, Lori; Tarn, Chi; Mburu, Sarah; Taguchi, Takahiro; Eisenberg, Burton; Godwin, Andrew K.

    2009-01-01

    Cell signaling plays a central role in the etiology of cancer. Numerous therapeutics in use or under development target signaling proteins, however off-target effects often limit assignment of positive clinical response to the intended target. As direct measurements of signaling protein activity are not generally feasible during treatment, there is a need for more powerful methods to determine if therapeutics inhibit their targets and when off-target effects occur. We have used the Bayesian Decomposition algorithm and data on transcriptional regulation to create a novel methodology, DESIDE (Differential Expression for SIgnaling DEtermination), for inferring signaling activity from microarray measurements. We applied DESIDE to deduce signaling activity in gastrointestinal stromal tumor cell lines treated with the targeted therapeutic imatinib mesylate (Gleevec). We detected the expected reduced activity in the KIT pathway, as well as unexpected changes in the P53 pathway. Pursuing these findings, we have determined that imatinib-induced DNA damage is responsible for the increased activity of P53, identifying a novel off-target activity for this drug. We then used DESIDE on data from resected, post-imatinib treatment tumor samples and identified a pattern in these tumors similar to that at late time points in the cell lines, and this pattern correlated with initial clinical response. The pattern showed increased activity of ELK1 and STAT3 transcription factors, which are associated with the growth of side population cells. DESIDE infers the global reprogramming of signaling networks during treatment, permitting treatment modification that leverages ongoing drug development efforts, which is crucial for personalized medicine. PMID:19903850

  1. Taurine ameliorates water avoidance stress-induced degenerations of gastrointestinal tract and liver.

    PubMed

    Zeybek, Ali; Ercan, Feriha; Cetinel, Sule; Cikler, Esra; Sağlam, Beyhan; Sener, Göksel

    2006-10-01

    We investigated the role of taurine, is a potent free radical scavenger, on water avoidance stress (WAS)-induced degeneration of the gastric, ileal, and colonic mucosa and liver parenchyma. Wistar albino rats were exposed to chronic WAS (WAS group) 2 hr daily for 5 days. After exposing animals to chronic WAS (WAS + taurine group), 50 mg/kg taurine was injected IP for 3 days. Control animals received vehicle solution only. The stomach, ileum, colon, and liver samples were investigated under light microscope for histopathologic changes. To demonstrate the topography of the luminal mucosa of the stomach, ileum, and colon, scanning electron microscope was used and for hepatocyte ultastructure transmission electron microscope was used. Malondialdehyde (MDA, a biomarker of oxidative damage) and glutathione (GSH, a biomarker of protective oxidative injury) levels were also determined in all tissues. In the WAS group, the stomach epithelium showed ulceration in some areas, dilatations of the gastric glands, and degeneration of gastric glandular cells; prominent congestion of the capillaries was apparent. In the WAS group, severe vascular congestion was observed along with degeneration of ileal and colonic epithelium. Prominent vascular congestion and dilated sinusoids, activated Kupffer cells, dilated granular endoplasmic reticulum membranes, and focal pyknotic nuclei were observed in liver parenchyma. MDA levels (stomach, P < 0.01; ileum, colon, and liver P < 0.05) were increased and GSH levels (P < 0.01) were decreased in all tissues in the WAS group compared with the control group. The morphology of gastric, ileal, and colonic mucosa and liver parenchyma in the WAS + taurine group (stomach and ileum, P < 0.05; colon and liver, P < 0.01) showed a significant amelioration when compared to the WAS group. Increased MDA and decreased GSH levels in the WAS group were ameliorated with taurine treatment. Based on the results, taurine supplementation effectively attenuates the

  2. A sulfated-polysaccharide fraction from seaweed Gracilaria birdiae prevents naproxen-induced gastrointestinal damage in rats.

    PubMed

    Silva, Renan O; Santana, Ana Paula M; Carvalho, Nathalia S; Bezerra, Talita S; Oliveira, Camila B; Damasceno, Samara R B; Chaves, Luciano S; Freitas, Ana Lúcia P; Soares, Pedro M G; Souza, Marcellus H L P; Barbosa, André Luiz R; Medeiros, Jand-Venes R

    2012-12-01

    Red seaweeds synthesize a great variety of sulfated galactans. Sulfated polysaccharides (PLSs) from seaweed are comprised of substances with pharmaceutical and biomedical potential. The aim of the present study was to evaluate the protective effect of the PLS fraction extracted from the seaweed Gracilaria birdiae in rats with naproxen-induced gastrointestinal damage. Male Wistar rats were pretreated with 0.5% carboxymethylcellulose (control group-vehicle) or PLS (10, 30, and 90 mg/kg, p.o.) twice daily (at 09:00 and 21:00) for 2 days. After 1 h, naproxen (80 mg/kg, p.o.) was administered. The rats were killed on day two, 4 h after naproxen treatment. The stomachs were promptly excised, opened along the greater curvature, and measured using digital calipers. Furthermore, the guts of the animals were removed, and a 5-cm portion of the small intestine (jejunum and ileum) was used for the evaluation of macroscopic scores. Samples of the stomach and the small intestine were used for histological evaluation, morphometric analysis and in assays for glutathione (GSH) levels, malonyldialdehyde (MDA) concentration, and myeloperoxidase (MPO) activity. PLS treatment reduced the macroscopic and microscopic naproxen-induced gastrointestinal damage in a dose-dependent manner. Our results suggest that the PLS fraction has a protective effect against gastrointestinal damage through mechanisms that involve the inhibition of inflammatory cell infiltration and lipid peroxidation.

  3. Hepatitis C virus E2 protein encapsulation into poly d, l-lactic-co-glycolide microspheres could induce mice cytotoxic T-cell response

    PubMed Central

    Roopngam, Piyachat; Liu, Kewei; Mei, Lin; Zheng, Yi; Zhu, Xianbing; Tsai, Hsiang-I; Huang, Laiqiang

    2016-01-01

    Hepatitis C virus (HCV) is known to cause hepatitis and hepatocellular carcinoma. E2 envelope glycoprotein of HCV type (HCV-E2) has been reported to bind human host cells and is a major target for developing anti-HCV vaccines. However, the therapeutic vaccine for infected patients still needs further development. The vaccine aims to provide cytotoxic T-cells to eliminate infected cells and hepatocellular carcinoma. Currently, there is no effective HCV therapeutic vaccine because most chronically infected patients rarely generate cytotoxic T-cells, even though they have high levels of neutralizing antibodies. Therefore, the adjuvant must be applied to enhance the efficacy of the therapeutic vaccine. In this study, we constructed HCV1b-E2 recombinant protein, a truncated form of peptide, to combine with an effective vaccine adjuvant and delivery system by using poly d,l-lactic-co-glycolide (PLGA) microspheres. HCV1b-E2 protein was effectively encapsulated into PLGA microspheres (HCV1b-E2-PLGA) as a strategy to deliver an insoluble form of HCV1b-E2 protein. The size and shape of PLGA microspheres were generated properly to carry an insoluble form of viral peptide in vivo. The encapsulated viral protein was slowly and continuously released from PLGA microspheres, which indicated the property of the adjuvant. HCV1b-E2-PLGA can trigger a cell-mediated immune response by inducing an expression of mice CD8+ T-cells. Our results demonstrated that HCV1b-E2-PLGA-immunized mice have a significantly increased CD8+ T-cell number, whereas HCV1b-E2-immunized mice have a lower number of CD8+ T-cells. Moreover, HCV1b-E2-PLGA could induce a specific antibody to viral protein, and the immune cells could secrete IFN-γ, which is a significant cytokine for viral response. Thus, HCV1b-E2-PLGA is shown to have adjuvant property and efficacy in the murine model, which is a good strategy to develop HCV prophylactic and therapeutic vaccines. PMID:27789948

  4. Chronic ingestion of a potential food contaminant induces gastrointestinal inflammation in rats: role of nitric oxide and mast cells.

    PubMed

    Anton, P M; Theodorou, V; Bertrand, V; Eutamene, H; Aussenac, T; Feyt, N; Fioramonti, J; Bueno, L

    2000-09-01

    Chronic ingestion of xenobiotics could be pathogenic in the gastrointestinal tract. Recently, we showed that acute low administration of a food contaminant (diquat) induced intestinal secretion involving mast cells and nitric oxide. This work aimed to determine in rats: (1) the influence of a low level (0.1 mg/kg/day per os) chronic ingestion of diquat on gastrointestinal immune cells, and (2) the participation of nitric oxide synthases (NOS) in these effects. Diquat increased both gastric and jejunal myeloperoxidase activities, tissue histamine in vitro release after stimulation by 48/80, and mast cell numbers. Diquat did not alter gastric NOS but increased intestinal inducible NOS (iNOS) activity. L-NAME prevented diquat-induced gastric and intestinal mastocytosis and gastric but not intestinal inflammation. L-NAME reduced gastric constitutive NOS (cNOS) activity and reestablished control iNOS activity. Chronic low level ingestion of diquat induces a low-grade gastric and intestinal inflammation with mastocytosis and enhancement of intestinal iNOS activity.

  5. Optimization of sustained release aceclofenac microspheres using response surface methodology.

    PubMed

    Deshmukh, Rameshwar K; Naik, Jitendra B

    2015-03-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14±0.015% to 85.34±0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12h. The optimized microspheres formulation showed E.E. of 84.87±0.005 with small error value (1.39). The low magnitudes of error and the significant value of R(2) in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects.

  6. Lithium-induced activation of Akt and CaM kinase II contributes to its neuroprotective action in a rat microsphere embolism model.

    PubMed

    Sasaki, Takuya; Han, Feng; Shioda, Norifumi; Moriguchi, Shigeki; Kasahara, Jiro; Ishiguro, Koichi; Fukunaga, Kohji

    2006-09-01

    Lithium used in bipolar mood disorder therapy protects neurons from brain ischemic cell death. Here, we documented that lithium administration under microsphere-embolism (ME)-induced brain ischemia restored decreased protein kinase B (Akt) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activities 24 h after ischemia in rat brain. Akt activation was associated with increased phosphorylation of its potential targets forkhead transcription factor (FKHR) and glycogen synthase kinase-3beta (GSK-3beta). In parallel with decreased CaMKII autophosphorylation, we also found marked dephosphorylation of tau proteins 24-72 h after ME. Increased protein phosphatase 2A (PP2A) activity was found 24 h after ME. Inhibition of increased PP2A activity by lithium treatment apparently mediated restored tau phosphorylation. Taken together, activation of Akt and CaMKII by lithium was associated with neuroprotective activity in ME-induced neuronal injury.

  7. Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement.

    PubMed

    Du, Zheren; Chen, Lianwei; Kao, Tsung-Sheng; Wu, Mengxue; Hong, Minghui

    2015-01-01

    For practical application, optical limiting materials must exhibit a fast response and a low threshold in order to be used for the protection of the human eye and electro-optical sensors against intense light. Many nanomaterials have been found to exhibit optical limiting properties. Laser ablation offers the possibility of fabricating nanoparticles from a wide range of target materials. For practical use of these materials, their optical limiting performance, including optical limiting threshold and the ability to efficiently attenuate high intensity light, needs to be improved. In this paper, we fabricate nanoparticles of different metals by laser ablation in liquid. We study the optical nonlinear properties of the laser-generated nanoparticle dispersion. Silica microspheres are used to enhance the optical limiting performance of the nanoparticle dispersion. The change in the optical nonlinear properties of the laser-generated nanoparticle dispersion caused by silica microspheres is studied. It is found that the incident laser beam is locally focused by the microspheres, leading to an increased optical nonlinearity of the nanoparticle dispersion.

  8. Efficacy of oral afoxolaner plus milbemycin oxime chewables against induced gastrointestinal nematode infections in dogs.

    PubMed

    Fankhauser, Rebecca; Hamel, Dietmar; Dorr, Paul; Reinemeyer, Craig R; Crafford, Dionne; Bowman, Dwight D; Ulrich, Michael; Yoon, Stephen; Larsen, Diane L

    2016-07-30

    The efficacy of oral afoxolaner plus milbemycin oxime combination chewables against induced gastrointestinal nematode infections in dogs was evaluated in six separate studies. Two studies were performed to evaluate the efficacy of the product against Toxocara canis, two studies evaluated the efficacy against Toxascaris leonina, one study evaluated the efficacy against Ancylostoma braziliense, and one study evaluated the efficacy against Ancylostoma caninum. In the A. caninum study, the efficacy of milbemycin oxime alone and afoxolaner alone was also evaluated. Dogs in all studies were inoculated with infective eggs or larvae and confirmed to have patent infections based on a fecal examination prior to allocation to study group and treatment. Each study utilized a randomized block design with blocks based on pre-treatment body weight. All dogs were assigned to blocks based on body weight, and then each dog within a block was randomly assigned to treatment group. There were two groups of 10 dogs each in the T. canis, T. leonina, and A. braziliense studies: 1) an untreated (control) group and 2) a group treated with afoxolaner plus milbemycin oxime chewables (NexGard Spectra(®), Merial). This group was treated at a dose as close as possible to the minimum effective dose of afoxolaner and milbemycin oxime (2.5mg+0.5mg per kg body weight, respectively) once on Day 0 using whole chews. There were four groups of 10 dogs each in the A. caninum study: 1) untreated (control), 2) NexGard Spectra(®) as described above, 3) milbemycin oxime alone (dose of at least 0.5mg per kg of body weight) and 4) afoxalaner alone (dose of at least 2.5mg per kg body weight). For parasite recovery and counts, dogs were euthanized humanely and necropsied seven days after treatment. The efficacy of the afoxolaner plus milbemycin oxime combination was ≥98% against T. canis, ≥95.8% against T. leonina, and 90.2% against A. braziliense. Efficacy of the combination against A. caninum was 99

  9. A Novel Method for Differentiation of Human Mesenchymal Stem Cells into Smooth Muscle-Like Cells on Clinically Deliverable Thermally Induced Phase Separation Microspheres

    PubMed Central

    Parmar, Nina; Ahmadi, Raheleh

    2015-01-01

    Muscle degeneration is a prevalent disease, particularly in aging societies where it has a huge impact on quality of life and incurs colossal health costs. Suitable donor sources of smooth muscle cells are limited and minimally invasive therapeutic approaches are sought that will augment muscle volume by delivering cells to damaged or degenerated areas of muscle. For the first time, we report the use of highly porous microcarriers produced using thermally induced phase separation (TIPS) to expand and differentiate adipose-derived mesenchymal stem cells (AdMSCs) into smooth muscle-like cells in a format that requires minimal manipulation before clinical delivery. AdMSCs readily attached to the surface of TIPS microcarriers and proliferated while maintained in suspension culture for 12 days. Switching the incubation medium to a differentiation medium containing 2 ng/mL transforming growth factor beta-1 resulted in a significant increase in both the mRNA and protein expression of cell contractile apparatus components caldesmon, calponin, and myosin heavy chains, indicative of a smooth muscle cell-like phenotype. Growth of smooth muscle cells on the surface of the microcarriers caused no change to the integrity of the polymer microspheres making them suitable for a cell-delivery vehicle. Our results indicate that TIPS microspheres provide an ideal substrate for the expansion and differentiation of AdMSCs into smooth muscle-like cells as well as a microcarrier delivery vehicle for the attached cells ready for therapeutic applications. PMID:25205072

  10. microsphere assemblies

    NASA Astrophysics Data System (ADS)

    Peña-Flores, Jesús I.; Palomec-Garfias, Abraham F.; Márquez-Beltrán, César; Sánchez-Mora, Enrique; Gómez-Barojas, Estela; Pérez-Rodríguez, Felipe

    2014-09-01

    The effect of Fe ion concentration on the morphological, structural, and optical properties of TiO2 films supported on silica (SiO2) opals has been studied. TiO2:Fe2O3 films were prepared by the sol-gel method in combination with a vertical dip coating procedure; precursor solutions of Ti and Fe were deposited on a monolayer of SiO2 opals previously deposited on a glass substrate by the same procedure. After the dip coating process has been carried out, the samples were thermally treated to obtain the TiO2:Fe2O3/SiO2 composites at the Fe ion concentrations of 1, 3, and 5 wt%. Scanning electron microscopy (SEM) micrographs show the formation of colloidal silica microspheres of about 50 nm diameter autoensembled in a hexagonal close-packed fashion. Although the X-ray diffractograms show no significant effect of Fe ion concentration on the crystal structure of TiO2, the μ-Raman and reflectance spectra do show that the intensity of a phonon vibration mode and the energy bandgap of TiO2 decrease as the Fe+3 ion concentration increases.

  11. Protective effect of wild raspberry (Rubus hirsutus Thunb.) extract against acrylamide-induced oxidative damage is potentiated after simulated gastrointestinal digestion.

    PubMed

    Chen, Wei; Su, Hongming; Xu, Yang; Bao, Tao; Zheng, Xiaodong

    2016-04-01

    Raspberry is well known as rich source of antioxidants, such as polyphenols and flavonoids. However, after consumption, the antioxidants are subjected to digestive conditions within the gastrointestinal tract that may result in structural and functional alterations. Our previous study indicated that acrylamide (AA)-induced cytotoxicity was associated with oxidative stress. However, the protective effect of wild raspberry extract produced before and after in vitro gastrointestinal digestion against AA-induced oxidative damage is unclear. In the present study, we found that wild raspberry extract produced after digestion (RD) had a pronounced protective effect against AA-induced cytotoxicity compared with that produced before digestion (RE). Further investigation indicated that RD significantly inhibited AA-induced intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) collapse and glutathione (GSH) depletion. Moreover, LC-MS analysis revealed that wild raspberry underwent gastrointestinal digestion significantly increased the contents of esculin, kaempferol hexoside and pelargonidin hexoside.

  12. Protective effect of wild raspberry (Rubus hirsutus Thunb.) extract against acrylamide-induced oxidative damage is potentiated after simulated gastrointestinal digestion.

    PubMed

    Chen, Wei; Su, Hongming; Xu, Yang; Bao, Tao; Zheng, Xiaodong

    2016-04-01

    Raspberry is well known as rich source of antioxidants, such as polyphenols and flavonoids. However, after consumption, the antioxidants are subjected to digestive conditions within the gastrointestinal tract that may result in structural and functional alterations. Our previous study indicated that acrylamide (AA)-induced cytotoxicity was associated with oxidative stress. However, the protective effect of wild raspberry extract produced before and after in vitro gastrointestinal digestion against AA-induced oxidative damage is unclear. In the present study, we found that wild raspberry extract produced after digestion (RD) had a pronounced protective effect against AA-induced cytotoxicity compared with that produced before digestion (RE). Further investigation indicated that RD significantly inhibited AA-induced intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) collapse and glutathione (GSH) depletion. Moreover, LC-MS analysis revealed that wild raspberry underwent gastrointestinal digestion significantly increased the contents of esculin, kaempferol hexoside and pelargonidin hexoside. PMID:26593576

  13. Laser-assisted fabrication of highly viscous alginate microsphere

    NASA Astrophysics Data System (ADS)

    Lin, Yafu; Huang, Yong

    2011-04-01

    Encapsulated microspheres have been widely used in various biomedical applications. However, fabrication of encapsulated microspheres from highly viscous materials has always been a manufacturing challenge. The objective of this study is to explore a novel metallic foil-assisted laser-induced forward transfer (LIFT), a laser-assisted fabrication technique, to make encapsulated microspheres using high sodium alginate concentration solutions. The proposed four-layer approach includes a quartz disk, a sacrificial and adhesive layer, a metallic foil, and a transferred suspension layer. It is found that the proposed four-layer modified LIFT approach provides a promising fabrication technology for making of bead-encapsulated microspheres from highly viscous solutions. During the process, the microsphere only can be formed if the direct-writing height is larger than the critical direct-writing height; otherwise, tail structured droplets are formed; and the encapsulated microsphere diameter linearly increases with the laser fluence and decreases with the sodium alginate concentration.

  14. Patterning of silica microsphere monolayers with focused femtosecond laser pulses

    SciTech Connect

    Cai Wenjian; Piestun, Rafael

    2006-03-13

    We demonstrate the patterning of monolayer silica microsphere lattices with tightly focused femtosecond laser pulses. We selectively removed microspheres from a lattice and characterized the effect on the lattice and the substrate. The proposed physical mechanism for the patterning process is laser-induced breakdown followed by ablation of material. We show that a microsphere focuses radiation in its interior and in the near field. This effect plays an important role in the patterning process by enhancing resolution and accuracy and by reducing the pulse energy threshold for damage. Microsphere patterning could create controlled defects within self-assembled opal photonic crystals.

  15. Beneficial effects of Camellia Oil (Camellia oleifera Abel.) on ketoprofen-induced gastrointestinal mucosal damage through upregulation of HO-1 and VEGF.

    PubMed

    Cheng, Yu-Ting; Wu, Shu-Li; Ho, Cheng-Ying; Huang, Shang-Ming; Cheng, Chun-Lung; Yen, Gow-Chin

    2014-01-22

    Nonsteroidal anti-inflammatory drugs, such as ketoprofen, are generally used to treat pain and inflammation and as pyretic agents in clinical medicine. However, the usage of these drugs may lead to oxidative injury to the gastrointestinal mucosa. Camellia oil ( Camellia oleifera Abel.) is commonly used in Taiwan and China as cooking oil. Traditional remedies containing this oil exert beneficial health effects on the bowel, stomach, liver, and lungs. However, the effects of camellia oil on ketoprofen-induced oxidative gastrointestinal mucosal lesions remain unknown. The objective of this study was to evaluate the effect of camellia oil on ketoprofen-induced acute gastrointestinal ulcers. The results showed that treatment of Int-407 cells with camellia oil (50-75 μg/mL) not only increased the levels of heme oxygenase-1 (HO-1), glutathione peroxidase (GPx), and superoxide dismutase (SOD) mRNA expression but also increased vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2) protein secretion, which served as a mucosal barrier against gastrointestinal oxidative injury. Moreover, Sprague-Dawley (SD) rats treated with camellia oil (2 mL/kg/day) prior to the administration of ketoprofen (50 mg/kg/day) successfully inhibited COX-2 protein expression, inhibited the production of interleukin-6 (IL-6) and nitrite oxide (NO), reversed the impairment of the antioxidant system, and decreased oxidative damage in the gastrointestinal mucosa. More importantly, pretreatment of SD rats with camellia oil strongly inhibited gastrointestinal mucosal injury induced by ketoprofen, which was proved by the histopathological staining of gastrointestinal tissues. Our data suggest that camellia oil exerts potent antiulcer effects against oxidative damage in the stomach and intestine induced by ketoprofen.

  16. Interference induced periodic oscillation of convolutional-surface-plasmon resonance for a metal nanoparticle encapsulated by a dielectric microsphere

    NASA Astrophysics Data System (ADS)

    Sun, Song; Liu, Huizhe; Wu, Lin; Eng Png, Ching; Bai, Ping

    2016-07-01

    A theoretical study is performed on the plasmonic properties of a metal nanoparticle encapsulated by a large microsphere, where the microsphere’s diameter is comparable with or larger than the incident wavelength. Due to interaction between the reflected and refracted waves, we show that a unique optical interference (or whisper-gallery-mode-like) pattern is generated inside the microsphere. Such an interference pattern further interacts with the metal nanoparticle embedded inside, which modifies the spectral response of the metal NP and creates a convolutional-surface-plasmon resonance (cSPR). The peak of resultant cSPR oscillates periodically with respect to the microsphere’s diameter due to the repeated occurrence of the constructive and destructive interferences. Our results also show that the periodicity of oscillation is mainly determined by the microsphere’s refractive index, but is less independent on the metal nanoparticle’s size. These findings might be potentially utilized in designing multi-scale plasmon structures in various applications such as sensors, drug delivery and photocatalysis.

  17. Mineralization, biodegradation, and drug release behavior of gelatin/apatite composite microspheres for bone regeneration.

    PubMed

    Leeuwenburgh, Sander C G; Jo, Junichiro; Wang, Huanan; Yamamoto, Masaya; Jansen, John A; Tabata, Yasuhiko

    2010-10-11

    Gelatin microspheres are well-known for their capacity to release growth factors in a controlled manner, but gelatin microspheres do not calcify in the absence of so-called bioactive substances that induce deposition of calcium phosphate (CaP) bone mineral. This study has investigated if CaP nanocrystals can be incorporated into gelatin microspheres to render these inert microspheres bioactive without compromising the drug releasing properties of gelatin microspheres. Incorporation of CaP nanocrystals into gelatin microspheres resulted into reduced biodegradation and drug release rates, whereas their calcifying capacity increased strongly compared to inert gelatin microspheres. The reduced drug release rate was correlated to the reduced degradation rate as caused by a physical cross-linking effect of CaP nanocrystals dispersed in the gelatin matrix. Consequently, these composite microspheres combine beneficial drug-releasing properties of organic gelatin with the calcifying capacity of a dispersed CaP phase. PMID:20804200

  18. Effect of trimebutine maleate on bethanechol-induced contractions of gastrointestinal tract in conscious and anaesthetized dogs.

    PubMed

    Yamada, K; Iizuka, M; Takaiti, O

    1983-04-01

    The effect of trimebutine maleate (TM-906) on bethanechol-induced contractions of the gastrointestinal tract in dogs was studied by means of chronically implanted force transducers, and it was compared with that of metoclopramide and atropine. During the period of motor quiescence in the fasted state of conscious dog, a bolus i.v. injection of 10 to 50 micrograms/kg bethanechol caused rhythmic contractions in the stomach and small intestine, in which an increase in basal tone was often accompanied in the distal ileum. The stomach responded to a less extent than the small intestine. Intravenous infusion of TM-906 at 3.0 mg/kg-hr for 20 to 60 min reduced the gastric contractions induced by 20 to 30 micrograms/kg bethanechol in five out of six conscious animals examined. The drug, however, enhanced the contractions of the duodenum and jejunum in a majority of the animals. Metoclopramide (1.8 mg/kg-hr) showed a tendency to potentiate the bethanechol-induced contractions in the stomach and small intestine, and atropine (0.06 mg/kg-hr) diminished them. In pentobarbital-Na anaesthetized dogs, effects of TM-906 on bethanechol-induced contractions resembled those in conscious dogs, inhibition in the stomach and potentiation in the small intestine. PMID:6136618

  19. Gastrointestinal bleeding secondary to trimethoprim-sulfamethoxazole-induced vitamin K deficiency.

    PubMed

    Fotouhie, Azadeh; Desai, Hem; King, Skye; Parsa, Nour Alhoda

    2016-06-06

    There is a well-known association between vitamin K deficiency and haemorrhagic events including gastrointestinal bleeding. There is also a well-known association between both poor dietary intake of vitamin K and chronic antibiotic use and the development of vitamin K deficiency. Although the medical literature notes that cephalosporin antibiotics have a propensity to cause vitamin K deficiency due to the molecular structure of the medications and their ability to suppress the synthesis of clotting factors, there are other antibiotics that have also been implicated in the development of vitamin K deficiency. There are very few reports of trimethoprim/sulfamethoxazole causing vitamin K deficiency and further leading to bleeding episodes. We present such a case and discuss the risk factors leading to such complications.

  20. Evaluation of antimotility effect of Lantana camara L. var. acuelata constituents on neostigmine induced gastrointestinal transit in mice

    PubMed Central

    Sagar, Lenika; Sehgal, Rajesh; Ojha, Sudarshan

    2005-01-01

    Background Lantana camara L. (Verbenaceae), a widely growing shrub which is toxic to some animal species, has been used in the traditional medicine for treating many ailments. The purpose of the present study was to evaluate the antimotility effects of Lantana camara leaf constituents in mice intestine. Methods Evaluation of antimotility activity was done in intestine of mice treated with Lantana camara leaf powder, Lantana camara methanolic extract (LCME), lantadene A, neostigmine and neostigmine + LCME. Neostigmine was used as a promotility agent. Intestinal motility was assessed by charcoal meal test and gastrointestinal transit rate was expressed as the percentage of the distance traversed by the charcoal divided by the total length of the small intestine. The antidiarrheal effect of LCME was studied against castor oil induced diarrhea model in mice. Results The intestinal transit with LCME at a dose of 500 mg/kg was 26.46% whereas the higher dose (1 g/kg) completely inhibited the transit of charcoal in normal mice. The % intestinal transit in the neostigmine pretreated groups was 24 and 11 at the same doses respectively. When the plant extracts at 125 and 250 mg/kg doses were administered intraperitonealy, there was significant reduction in fecal output compared with castor oil treated mice. At higher doses (500 and 1000 mg/kg), the fecal output was almost completely stopped. Conclusion The remarkable antimotility effect of Lantana camara methanolic extract against neostigmine as promotility agent points towards an anticholinergic effect due to Lantana camara constituents and attests to its possible utility in secretory and functional diarrheas and other gastrointestinal disorders. This effect was further confirmed by significant inhibition of castor oil induced diarrhea in mice by various doses of LCME. PMID:16168064

  1. Novel Regenerative Peptide TP508 Mitigates Radiation-Induced Gastrointestinal Damage By Activating Stem Cells and Preserving Crypt Integrity

    PubMed Central

    Kantara, Carla; Moya, Stephanie M.; Houchen, Courtney W.; Umar, Shahid; Ullrich, Robert L.; Singh, Pomila; Carney, Darrell H.

    2015-01-01

    In recent years, increasing threats of radiation exposure and nuclear disasters have become a significant concern for the United States and countries worldwide. Exposure to high doses of radiation triggers a number of potentially lethal effects. Among the most severe is the gastrointestinal (GI) toxicity syndrome caused by the destruction of the intestinal barrier, resulting in bacterial translocation, systemic bacteremia, sepsis and death. The lack of effective radioprotective agents capable of mitigating radiation-induced damage has prompted a search for novel countermeasures that can mitigate the effects of radiation post-exposure, accelerate tissue repair in radiation-exposed individuals, and prevent mortality. We report that a single injection of regenerative peptide TP508 (rusalatide acetate, Chrysalin®) 24h after lethal radiation exposure (9Gy, LD100/15) appears to significantly increase survival and delay mortality by mitigating radiation-induced intestinal and colonic toxicity. TP508 treatment post-exposure prevents the disintegration of gastrointestinal crypts, stimulates the expression of adherens junction protein E-cadherin, activates crypt cell proliferation, and decreases apoptosis. TP508 post-exposure treatment also up-regulates the expression of DCLK1 and LGR5 markers of stem cells that have been shown to be responsible for maintaining and regenerating intestinal crypts. Thus, TP508 appears to mitigate the effects of GI toxicity by activating radioresistant stem cells and increasing the stemness potential of crypts to maintain and restore intestinal integrity. These results suggest that TP508 may be an effective emergency nuclear countermeasure that could be delivered within 24h post-exposure to increase survival and delay mortality, giving victims time to reach clinical sites for advanced medical treatment. PMID:26280221

  2. Production of hollow aerogel microspheres

    DOEpatents

    Upadhye, Ravindra S.; Henning, Sten A.

    1993-01-01

    A method is described for making hollow aerogel microspheres of 800-1200 .mu. diameter and 100-300 .mu. wall thickness by forming hollow alcogel microspheres during the sol/gel process in a catalytic atmosphere and capturing them on a foam surface containing catalyst. Supercritical drying of the formed hollow alcogel microspheres yields hollow aerogel microspheres which are suitable for ICF targets.

  3. Production of hollow aerogel microspheres

    SciTech Connect

    Upadhye, R.S.; Henning, S.A.

    1990-12-31

    A method is described for making hollow aerogel microspheres of 800--1200{mu} diameter and 100--300{mu} wall thickness by forming hollow alcogel microspheres during the sol/gel process in a catalytic atmosphere and capturing them on a foam surface containing catalyst. Supercritical drying of the formed hollow alcogel microspheres yields hollow aerogel microspheres which are suitable for ICF targets.

  4. Metabolism of proteinoid microspheres

    NASA Technical Reports Server (NTRS)

    Nakashima, T.; Fox, S. W. (Principal Investigator)

    1987-01-01

    The literature of metabolism in proteinoids and proteinoid microspheres is reviewed and criticized from a biochemical and experimental point of view. Closely related literature is also reviewed in order to understand the function of proteinoids and proteinoid microspheres. Proteinoids or proteinoid microspheres have many activities. Esterolysis, decarboxylation, amination, deamination, and oxidoreduction are catabolic enzyme activities. The formation of ATP, peptides or oligonucleotides is synthetic enzyme activities. Additional activities are hormonal and inhibitory. Selective formation of peptides is an activity of nucleoproteinoid microspheres; these are a model for ribosomes. Mechanisms of peptide and oligonucleotide syntheses from amino acids and nucleotide triphosphate by proteinoid microspheres are tentatively proposed as an integrative consequence of reviewing the literature.

  5. Metabolism of proteinoid microspheres

    NASA Technical Reports Server (NTRS)

    Nakashima, T.; Fox, S. W. (Principal Investigator)

    1987-01-01

    The literature of metabolism in proteinoids and proteinoid microspheres is reviewed and criticized from a biochemical and experimental point of view. Closely related literature is also reviewed in order to understand the function of proteinoids and proteinoid microspheres. Proteinoids or proteinoid microspheres have many activities. Esterolyis, decarboxylation, amination, deamination, and oxidoreduction are catabolic enzyme activities. The formation of ATP, peptides or oligonucleotides is synthetic enzyme activities. Additional activities are hormonal and inhibitory. Selective formation of peptides is an activity of nucleoproteinoid microspheres; these are a model for ribosomes. Mechanisms of peptide and oligonucleotide syntheses from amino acids and nucleotide triphosphate by proteinoid microspheres are tentatively proposed as an integrative consequence of reviewing the literature.

  6. Computational dynamics of acoustically driven microsphere systems.

    PubMed

    Glosser, Connor; Piermarocchi, Carlo; Li, Jie; Dault, Dan; Shanker, B

    2016-01-01

    We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the interparticle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of nondissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation of the system, though we also observe both expansion and contraction of the cloud determined by the initial system geometry. PMID:26871188

  7. Computational dynamics of acoustically driven microsphere systems.

    PubMed

    Glosser, Connor; Piermarocchi, Carlo; Li, Jie; Dault, Dan; Shanker, B

    2016-01-01

    We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the interparticle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of nondissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation of the system, though we also observe both expansion and contraction of the cloud determined by the initial system geometry.

  8. Mycobacterium hsp65 DNA entrapped into TDM-loaded PLGA microspheres induces protection in mice against Leishmania (Leishmania) major infection.

    PubMed

    Coelho, Eduardo Antonio Ferraz; Tavares, Carlos Alberto Pereira; Lima, Karla de Melo; Silva, Célio Lopes; Rodrigues, José Maciel; Fernandes, Ana Paula

    2006-05-01

    Heat shock proteins (HSPs) are highly conserved among different organisms. A mycobacterial HSP65 DNA vaccine was previously shown to have prophylactic and immunotherapeutic effects against Mycobacterium tuberculosis infection in mice. Here, BALB/c mice were immunized with mycobacterial DNA-hsp65 or with DNA-hsp65 and trehalose dymicolate (TDM), both carried by biodegradable microspheres (MHSP/TDM), and challenged with Leishmania (Leishmania) major. MHSP/TDM conferred protection against L. major infection, as indicated by a significant reduction of edema and parasite loads in infected tissues. Although high levels of interferon-gamma and low levels of interleukin (IL)-4 and IL-10 were detected in mice immunized with DNA-hsp65 or MHSP/TDM, only animals immunized with MHSP/TDM displayed a consistent Th1 immune response, i.e., significantly higher levels of anti-soluble Leishmania antigen (SLA) immunoglobulin G (IgG)2a and low anti-SLA IgG1 antibodies. These findings indicate that encapsulated MHSP/TDM is more immunogenic than naked hsp65 DNA, and has great potential to improve vaccine effectiveness against leishmaniasis and tuberculosis. PMID:16432754

  9. An oral DNA vaccine against infectious haematopoietic necrosis virus (IHNV) encapsulated in alginate microspheres induces dose-dependent immune responses and significant protection in rainbow trout (Oncorrhynchus mykiss).

    PubMed

    Ballesteros, Natalia A; Alonso, Marta; Saint-Jean, Sylvia Rodríguez; Perez-Prieto, Sara I

    2015-08-01

    Administered by intramuscular injection, a DNA vaccine (pIRF1A-G) containing the promoter regions upstream of the rainbow trout interferon regulatory factor 1A gene (IRF1A) driven the expression of the infectious hematopoietic necrosis virus (IHNV) glycoprotein (G) elicited protective immune responses in rainbow trout (Oncorhynchus mykiss). However, less laborious and cost-effective routes of DNA vaccine delivery are required to vaccinate large numbers of susceptible farmed fish. In this study, the pIRF1A-G vaccine was encapsulated into alginate microspheres and orally administered to rainbow trout. At 1, 3, 5, and 7 d post-vaccination, IHNV G transcripts were detected by quantitative real-time PCR in gills, spleen, kidney and intestinal tissues of vaccinated fish. This result suggested that the encapsulation of pIRF1A-G in alginate microparticles protected the DNA vaccine from degradation in the fish stomach and ensured vaccine early delivery to the hindgut, vaccine passage through the intestinal mucosa and its distribution thought internal and external organs of vaccinated fish. We also observed that the oral route required approximately 20-fold more plasmid DNA than the injection route to induce the expression of significant levels of IHNV G transcripts in kidney and spleen of vaccinated fish. Despite this limitation, increased IFN-1, TLR-7 and IgM gene expression was detected by qRT-PCR in kidney of vaccinated fish when a 10 μg dose of the oral pIRF1A-G vaccine was administered. In contrast, significant Mx-1, Vig-1, Vig-2, TLR-3 and TLR-8 gene expression was only detected when higher doses of pIRF1A-G (50 and 100 μg) were orally administered. The pIRF1A-G vaccine also induced the expression of several markers of the adaptive immune response (CD4, CD8, IgM and IgT) in kidney and spleen of immunized fish in a dose-dependent manner. When vaccinated fish were challenged by immersion with live IHNV, evidence of a dose-response effect of the oral vaccine could also

  10. In situ growth of copper nanocrystals from carbonaceous microspheres with electrochemical glucose sensing properties

    SciTech Connect

    Zhou, Xiaoliang; Yan, Zhengguang Han, Xiaodong

    2014-02-01

    Graphical abstract: In situ growth of copper nanoparticles from hydrothermal copper-containing carbonaceous microspheres was induced by annealing or electron beam irradiation. Obtained micro-nano carbon/copper composite microspheres show electrochemical glucose sensing properties. - Highlights: • We synthesized carbonaceous microspheres containing non-nanoparicle copper species through a hydrothermal route. • By annealing or electron beam irradiation, copper nanoparticles would form from the carbonaceous microspheres in situ. • By controlling the annealing temperature, particle size of copper could be controlled in the range of 50–500 nm. • The annealed carbon/copper hierarchical composite microspheres were used to fabricate an electrochemical glucose sensor. - Abstract: In situ growth of copper nanocrystals from carbon/copper microspheres was observed in a well-controlled annealing or an electron beam irradiation process. Carbonaceous microspheres containing copper species with a smooth appearance were yielded by a hydrothermal synthesis using copper nitrate and ascorbic acid as reactants. When annealing the carbonaceous microspheres under inert atmosphere, copper nanoparticles were formed on carbon microspheres and the copper particle sizes can be increased to a range of 50–500 nm by altering the heating temperature. Similarly, in situ formation of copper nanocrystals from these carbonaceous microspheres was observed on the hydrothermal product carbonaceous microspheres with electron beam irradiation in a vacuum transmission electron microscopy chamber. The carbon/copper composite microspheres obtained through annealing were used to modify a glassy carbon electrode and tested as an electrochemical glucose sensor.

  11. Effect of adding non-volatile oil as a core material for the floating microspheres prepared by emulsion solvent diffusion method.

    PubMed

    Lee, J H; Park, T G; Lee, Y B; Shin, S C; Choi, H K

    2001-01-01

    Eudragit microspheres, to float in the gastrointestinal tract, were prepared to prolong a gastrointestinal transit time. To enhance their buoyancy, non-volatile oil was added to the dispersed phase. When an oil component was not miscible with water, over 90% was entrapped within the microspheres and prolonged the floating time of the microspheres. Depending on the solvent ratio, the morphologies of the microspheres were different and the best result was obtained when the ratio of dichloromethane:ethanol:isopropanol was 5:6:4. As the isopropanol portion increased, the time to form microspheres was delayed and the amount of fibre-like substance produced was decreased, due to the slow diffusion rate of the solvent. Compared with microspheres prepared without non-volatile oil, the release rate of the drug from microspheres was faster in all cases tested, except the microspheres containing mineral oil. The solubility of the drug in the non-volatile oil affected the release profiles of the drugs. The non-volatile oil tends to decrease the glass transition temperature of prepared microspheres and change the release profile. The internal morphology of the microspheres was slightly different depending on the entrapped oil phase used. Tiny spherical objects were present at the inner surface of microspheres and the inside of the shell.

  12. Efficacy of thiolated eudragit microspheres as an oral vaccine delivery system to induce mucosal immunity against enterotoxigenic Escherichia coli in mice.

    PubMed

    Lee, Won-Jung; Cha, Seungbin; Shin, Minkyoung; Jung, Myunghwan; Islam, Mohammad Ariful; Cho, Chong-su; Yoo, Han Sang

    2012-05-01

    A vaccine delivery system based on thiolated eudragit microsphere (TEMS) was studied in vivo for its ability to elicit mucosal immunity against enterotoxigenic Escherichia coli (ETEC). Groups of mice were orally immunized with F4 or F18 fimbriae of ETEC and F4 or F18 loaded in TEMS. Mice that were orally administered with F4 or F18 loaded TEMS showed higher antigen-specific IgG antibody responses in serum and antigen-specific IgA in saliva and feces than mice that were immunized with antigens only. In addition, oral vaccination of F4 or F18 loaded TEMS resulted in higher numbers of IgG and IgA antigen-specific antibody secreting cells in the spleen, lamina propria, and Peyer's patches of immunized mice than other groups. Moreover, TEMS administration loaded with F4 or F18 induced mixed Th1 and Th2 type responses based on similarly increased levels of IgG1 and IgG2a. These results suggest that F4 or F18 loaded TEMS may be a promising candidate for an oral vaccine delivery system to elicit systemic and mucosal immunity against ETEC. PMID:22306699

  13. Surface Wrinkling on Polydimethylsiloxane Microspheres via Wet Surface Chemical Oxidation

    PubMed Central

    Yin, Jian; Han, Xue; Cao, Yanping; Lu, Conghua

    2014-01-01

    Here we introduce a simple low-cost yet robust method to realize spontaneously wrinkled morphologies on spherical surfaces. It is based on surface chemical oxidation of aqueous-phase-synthesized polydimethylsiloxane (PDMS) microspheres in the mixed H2SO4/HNO3/H2O solution. Consequently, curvature and overstress-sensitive wrinkles including dimples and labyrinth patterns are successfully induced on the resulting oxidized PDMS microspheres. A power-law dependence of the wrinkling wavelength on the microsphere radius exists. The effects of experimental parameters on these tunable spherical wrinkles have been systematically investigated, when the microspheres are pre-deposited on a substrate. These parameters include the radius and modulus of microspheres, the mixed acid solution composition, the oxidation duration, and the water washing post-treatment. Meanwhile, the complicated chemical oxidation process has also been well studied by in-situ optical observation via the microsphere system, which represents an intractable issue in a planar system. Furthermore, we realize surface wrinkled topographies on the whole microspheres at a large scale, when microspheres are directly dispersed in the mixed acid solution for surface oxidation. These results indicate that the introduced wet surface chemical oxidation has the great potential to apply to other complicated curved surfaces for large-scale generation of well-defined wrinkling patterns, which endow the solids with desired physical properties. PMID:25028198

  14. Surface Wrinkling on Polydimethylsiloxane Microspheres via Wet Surface Chemical Oxidation

    NASA Astrophysics Data System (ADS)

    Yin, Jian; Han, Xue; Cao, Yanping; Lu, Conghua

    2014-07-01

    Here we introduce a simple low-cost yet robust method to realize spontaneously wrinkled morphologies on spherical surfaces. It is based on surface chemical oxidation of aqueous-phase-synthesized polydimethylsiloxane (PDMS) microspheres in the mixed H2SO4/HNO3/H2O solution. Consequently, curvature and overstress-sensitive wrinkles including dimples and labyrinth patterns are successfully induced on the resulting oxidized PDMS microspheres. A power-law dependence of the wrinkling wavelength on the microsphere radius exists. The effects of experimental parameters on these tunable spherical wrinkles have been systematically investigated, when the microspheres are pre-deposited on a substrate. These parameters include the radius and modulus of microspheres, the mixed acid solution composition, the oxidation duration, and the water washing post-treatment. Meanwhile, the complicated chemical oxidation process has also been well studied by in-situ optical observation via the microsphere system, which represents an intractable issue in a planar system. Furthermore, we realize surface wrinkled topographies on the whole microspheres at a large scale, when microspheres are directly dispersed in the mixed acid solution for surface oxidation. These results indicate that the introduced wet surface chemical oxidation has the great potential to apply to other complicated curved surfaces for large-scale generation of well-defined wrinkling patterns, which endow the solids with desired physical properties.

  15. Elaboration and characterization of soy/zein protein microspheres for controlled nutraceutical delivery.

    PubMed

    Chen, Lingyun; Subirade, Muriel

    2009-12-14

    Microspheres (15-25 microm) of soy protein isolate (SPI), zein, and SPI/zein blends were prepared using a cold gelation method as possible delivery systems for nutraceutical products. Microsphere matrix crystalline structure, swelling behavior, and nutrient load release kinetics in simulated gastrointestinal fluids were investigated. SPI microspheres showed early burst release of the model nutrient, whereas zein microspheres showed very slow release in both simulated gastric and intestinal fluids. Blending of SPI and zein provides a convenient method of adjusting the hydrophobicity and crystallinity of the protein matrix and hence its swelling behavior and in vivo nutrient release kinetics. Diffusion plays a major role in regulating nutrient release. SPI/zein microspheres blended at ratios of 5:5 and 3:7 showed near zero-order release kinetics over the test period in simulated intestinal buffer and thus have potential as delivery vehicles for nutraceutical products in functional foods.

  16. Biologically erodable microspheres as potential oral drug delivery systems

    NASA Astrophysics Data System (ADS)

    Mathiowitz, Edith; Jacob, Jules S.; Jong, Yong S.; Carino, Gerardo P.; Chickering, Donald E.; Chaturvedi, Pravin; Santos, Camilla A.; Vijayaraghavan, Kavita; Montgomery, Sean; Bassett, Michael; Morrell, Craig

    1997-03-01

    Biologically adhesive delivery systems offer important advantages1-5 over conventional drug delivery systems6. Here we show that engineered polymer microspheres made of biologically erodable polymers, which display strong adhesive interactions with gastrointestinal mucus and cellular linings, can traverse both the mucosal absorptive epithelium and the follicle-associated epithelium covering the lymphoid tissue of Peyer's patches. The polymers maintain contact with intestinal epithelium for extended periods of time and actually penetrate it, through and between cells. Thus, once loaded with compounds of pharmacological interest, the microspheres could be developed as delivery systems to transfer biologically active molecules to the circulation. We show that these microspheres increase the absorption of three model substances of widely different molecular size: dicumarol, insulin and plasmid DNA.

  17. Organic aerogel microspheres

    DOEpatents

    Mayer, S.T.; Kong, F.M.; Pekala, R.W.; Kaschmitter, J.L.

    1999-06-01

    Organic aerogel microspheres are disclosed which can be used in capacitors, batteries, thermal insulation, adsorption/filtration media, and chromatographic packings, having diameters ranging from about 1 micron to about 3 mm. The microspheres can be pyrolyzed to form carbon aerogel microspheres. This method involves stirring the aqueous organic phase in mineral oil at elevated temperature until the dispersed organic phase polymerizes and forms nonstick gel spheres. The size of the microspheres depends on the collision rate of the liquid droplets and the reaction rate of the monomers from which the aqueous solution is formed. The collision rate is governed by the volume ratio of the aqueous solution to the mineral oil and the shear rate, while the reaction rate is governed by the chemical formulation and the curing temperature.

  18. Organic aerogel microspheres

    DOEpatents

    Mayer, Steven T.; Kong, Fung-Ming; Pekala, Richard W.; Kaschmitter, James L.

    1999-01-01

    Organic aerogel microspheres which can be used in capacitors, batteries, thermal insulation, adsorption/filtration media, and chromatographic packings, having diameters ranging from about 1 micron to about 3 mm. The microspheres can be pyrolyzed to form carbon aerogel microspheres. This method involves stirring the aqueous organic phase in mineral oil at elevated temperature until the dispersed organic phase polymerizes and forms nonsticky gel spheres. The size of the microspheres depends on the collision rate of the liquid droplets and the reaction rate of the monomers from which the aqueous solution is formed. The collision rate is governed by the volume ratio of the aqueous solution to the mineral oil and the shear rate, while the reaction rate is governed by the chemical formulation and the curing temperature.

  19. Gastrointestinal Infections.

    PubMed

    Alby, Kevin; Nachamkin, Irving

    2016-06-01

    Gastrointestinal infections in the immunocompromised host are caused by the common bacterial, viral, fungal, and parasitic agents that also cause infections in the immunocompetent host. Of special consideration is that immunocompromised patients may be at increased risk for infection or disease severity and by pathogens not seen in the competent host. This chapter reviews the various agents, risk factors, and diagnostic approaches to detect gastrointestinal infections in this patient population. PMID:27337464

  20. Gastrointestinal and systemic toxicity of fecal extracts from hamsters with clindamycin-induced colitis.

    PubMed

    Rifkin, G D; Silva, J; Fekety, R

    1978-01-01

    The production of toxic substances by intestinal bacteria is one pathogenic mechanism proposed for antibiotic-associated colitis. We demonstrated the presence of a toxic substance(s) in the feces of hamsters developing clindamycin-induced enterocolitis. Suspensions derived from cecal contents of clindamycin-treated animals induced a hemorrhagic ileocecitis and death within 2 to 4 days after being given orogastrically to hamsters. Intraperitoneal injection of sterile filtrates of these suspensions produced an exudative peritonitis, intraabdominal hemorrhages, and death of 80 to 100% of hamsters within 1 day. These effects were not seen with intraperitoneal injection of clindamycin or endotoxin, only small amounts of which were present in the filtrate. Incubation of the filtrate in vitro with polyvalent clostridial antitoxin neuralized its toxicity. In vitro incubation of the filtrate with normal equine serum did not reduce its in vivo toxicity. The toxic substance(s) contained in the filtrate was heat-labile and produced morphological changes in Y-1 adrenal cell cultures characteristic of heat-labile enterotoxins. Cecal filtrates obtained from saline-treated animals produced none of these effects. These preliminary studies suggest that enterotoxin-like substances, possibly produced by clostridia, may play an important role in the pathogenesis of clindamycin-induced colitis in the hamster.

  1. Irinotecan-Induced Gastrointestinal Dysfunction and Pain Are Mediated by Common TLR4-Dependent Mechanisms.

    PubMed

    Wardill, Hannah R; Gibson, Rachel J; Van Sebille, Ysabella Z A; Secombe, Kate R; Coller, Janet K; White, Imogen A; Manavis, Jim; Hutchinson, Mark R; Staikopoulos, Vasiliki; Logan, Richard M; Bowen, Joanne M

    2016-06-01

    Strong epidemiological data indicate that chemotherapy-induced gut toxicity and pain occur in parallel, indicating common underlying mechanisms. We have recently outlined evidence suggesting that TLR4 signaling may contribute to both side effects. We therefore aimed to determine if genetic deletion of TLR4 improves chemotherapy-induced gut toxicity and pain. Forty-two female wild-type (WT) and 42 Tlr4 null (-/-) BALB/c mice weighing between 18 and 25 g (10-13 weeks) received a single 270 mg/kg (i.p.) dose of irinotecan hydrochloride or vehicle control and were killed at 6, 24, 48, 72, and 96 hours. Bacterial sequencing was conducted on cecal samples of control animals to determine the gut microbiome profile. Gut toxicity was assessed using validated clinical and histopathologic markers, permeability assays, and inflammatory markers. Chemotherapy-induced pain was assessed using the validated rodent facial grimace criteria, as well as immunologic markers of glial activation in the lumbar spinal cord. TLR4 deletion attenuated irinotecan-induced gut toxicity, with improvements in weight loss (P = 0.0003) and diarrhea (P < 0.0001). Crypt apoptosis was significantly decreased in BALB/c-Tlr4(-/-billy) mice (P < 0.0001), correlating with lower mucosal injury scores (P < 0.005). Intestinal permeability to FITC-dextran (4 kDa) and LPS translocation was greater in WT mice than in BALB/c-Tlr4(-/-billy) (P = 0.01 and P < 0.0001, respectively). GFAP staining in the lumbar spinal cord, indicative of astrocytic activation, was increased at 6 and 72 hours in WT mice compared with BALB/c-Tlr4(-/-billy) mice (P = 0.008, P = 0.01). These data indicate that TLR4 is uniquely positioned to mediate irinotecan-induced gut toxicity and pain, highlighting the possibility of a targetable gut/CNS axis for improved toxicity outcomes. Mol Cancer Ther; 15(6); 1376-86. ©2016 AACR. PMID:27197307

  2. POROUS WALL, HOLLOW GLASS MICROSPHERES

    SciTech Connect

    Sexton, W.

    2012-06-30

    magnitude, which can result in unique properties in areas such as hydrogen storage, gas transport, gas separations and purifications, sensors, global warming applications, new drug delivery systems and so on. One of the most interesting porous glass products that SRNL has developed and patented is Porous Wall, Hollow Glass Microspheres (PW-HGMs) that are being studied for many different applications. The European Patent Office (EPO) just recently notified SRS that the continuation-in-part patent application for the PW-HGMs has been accepted. The original patent, which was granted by the EPO on June 2, 2010, was validated in France, Germany and the United Kingdom. The microspheres produced are generally in the range of 2 to 100 microns, with a 1 to 2 micron wall. What makes the SRNL microspheres unique from all others is that the team in Figure 1 has found a way to induce and control porosity through the thin walls on a scale of 100 to 3000 {angstrom}. This is what makes the SRNL HW-HGMs one-of-a-kind, and is responsible for many of their unique properties and potential for various applications, including those in tritium storage, gas separations, H-storage for vehicles, and even a variety of new medical applications in the areas of drug delivery and MRI contrast agents. SRNL Hollow Glass Microspheres, and subsequent, Porous Wall, Hollow Glass Microspheres are fabricated using a flame former apparatus. Figure 2 is a schematic of the apparatus.

  3. A role of CB1R in inducing θ-rhythm coordination between the gustatory and gastrointestinal insula.

    PubMed

    Kang, Youngnam; Sato, Hajime; Saito, Mitsuru; Yin, Dong Xu; Park, Sook Kyung; Oh, Seog Bae; Bae, Yong Chul; Toyoda, Hiroki

    2016-01-01

    Anandamide (AEA) and N-oleoylethanolamine (OEA) are produced in the intestine and brain during fasting and satiety, respectively. Subsequently, AEA facilitates food intake via activation of cannabinoid type-1 receptors (CB1Rs) while OEA decreases food intake via activation of peroxisome proliferator-activated receptor-α (PPARα) and/or G-protein-coupled receptor 119 (GPR119). Neuronal activity in the gastrointestinal region of the autonomic insula (GI-Au-I) that rostrally adjoins the gustatory insula (Gu-I) increases during fasting, enhancing appetite while umami and sweet taste sensations in Gu-I enhances appetite in GI-Au-I, strongly suggesting the presence of a neural interaction between the Gu-I and GI-Au-I which changes depending on the concentrations of AEA and OEA. However, this possibility has never been investigated. In rat slice preparations, we demonstrate with voltage-sensitive dye imaging that activation of CB1Rs by AEA induces θ-rhythm oscillatory synchronization in the Gu-I which propagates into the GI-Au-I but stops at its caudal end, displaying an oscillatory coordination. The AEA-induced oscillation was abolished by a CB1R antagonist or OEA through activation of GPR119. Our results demonstrate that the neural coordination between the Gu-I and GI-Au-I is generated or suppressed by the opposing activities between CB1R and GPR119. This mechanism may be involved in the feeding behavior based on taste recognition. PMID:27581068

  4. A role of CB1R in inducing θ-rhythm coordination between the gustatory and gastrointestinal insula

    PubMed Central

    Kang, Youngnam; Sato, Hajime; Saito, Mitsuru; Yin, Dong Xu; Park, Sook Kyung; Oh, Seog Bae; Bae, Yong Chul; Toyoda, Hiroki

    2016-01-01

    Anandamide (AEA) and N-oleoylethanolamine (OEA) are produced in the intestine and brain during fasting and satiety, respectively. Subsequently, AEA facilitates food intake via activation of cannabinoid type-1 receptors (CB1Rs) while OEA decreases food intake via activation of peroxisome proliferator-activated receptor-α (PPARα) and/or G-protein-coupled receptor 119 (GPR119). Neuronal activity in the gastrointestinal region of the autonomic insula (GI-Au-I) that rostrally adjoins the gustatory insula (Gu-I) increases during fasting, enhancing appetite while umami and sweet taste sensations in Gu-I enhances appetite in GI-Au-I, strongly suggesting the presence of a neural interaction between the Gu-I and GI-Au-I which changes depending on the concentrations of AEA and OEA. However, this possibility has never been investigated. In rat slice preparations, we demonstrate with voltage-sensitive dye imaging that activation of CB1Rs by AEA induces θ-rhythm oscillatory synchronization in the Gu-I which propagates into the GI-Au-I but stops at its caudal end, displaying an oscillatory coordination. The AEA-induced oscillation was abolished by a CB1R antagonist or OEA through activation of GPR119. Our results demonstrate that the neural coordination between the Gu-I and GI-Au-I is generated or suppressed by the opposing activities between CB1R and GPR119. This mechanism may be involved in the feeding behavior based on taste recognition. PMID:27581068

  5. Effect of proanthocyanidin, arginine and glutamine supplementation on methotrexate-induced gastrointestinal toxicity in rats.

    PubMed

    Gulgun, M; Karaoglu, A; Kesik, V; Kurt, B; Erdem, O; Tok, D; Kismet, E; Koseoglu, V; Ozcan, O

    2010-11-01

    Methotrexate is a folate antagonist that is commonly used as an antitumor and antiarthritic drug. The aim of this study was to investigate the possible roles of exogenous glutamine (Glu), arginine (Arg) and proanthocyanidin (PA) on gut protection from methotrexate-induced intestinal damage in rats. Experimental rats were separated into eight groups. The first (sham) group received a 0.9% NaCl solution alone. The second group received intraperitoneal injections of methotrexate (20 mg/kg/day) administered on day 4 of the experiment and continued for 5 days. Rats in the other six groups were administered PA, Glu, Arg, Glu+PA, Arg+PA or Glu+Arg orally by gavage together with methotrexate and animals were sacrificed on day 8 of the experiment. All animals were sacrificed 4 days after methotrexate injection for histopathological analysis, tissue glutathione peroxidase, malondialdehyde and superoxide dismutase assays. Proanthocyanidin and Glu decreased the severity of intestinal injury and oxidant injury as evident by histopathology and changes in malondialdehyde levels. Histological analysis confirmed that PA and to a lesser extent Glu supplementation were more favorable than Arg for the protection of the small intestine from methotrexate-induced injury.

  6. Radiotherapy combined with TLR7/8 activation induces strong immune responses against gastrointestinal tumors.

    PubMed

    Schölch, Sebastian; Rauber, Conrad; Tietz, Alexandra; Rahbari, Nuh N; Bork, Ulrich; Schmidt, Thomas; Kahlert, Christoph; Haberkorn, Uwe; Tomai, Mark A; Lipson, Kenneth E; Carretero, Rafael; Weitz, Jürgen; Koch, Moritz; Huber, Peter E

    2015-03-10

    In addition to local cytotoxic activity, radiotherapy may also elicit local and systemic antitumor immunity, which may be augmented by immunotherapeutic agents including Toll-like receptor (TLR) 7/8 agonists. Here, we investigated the ability of 3M-011 (854A), a TLR7/8 agonist, to boost the antigen-presenting activity of dendritic cells (DC) as an adjuvant to radiotherapy. The combined treatment induced marked local and systemic responses in subcutaneous and orthotopic mouse models of colorectal and pancreatic cancer. In vitro cytotoxicity assays as well as in vivo depletion experiments with monoclonal antibodies identified NK and CD8 T cells as the cell populations mediating the cytotoxic effects of the treatment, while in vivo depletion of CD11c+ dendritic cells (DC) in CD11c-DTR transgenic mice revealed DC as the pivotal immune hub in this setting. The specificity of the immune reaction was confirmed by ELISPOT assays. TLR7/8 agonists therefore seem to be potent adjuvants to radiotherapy, inducing strong local and profound systemic immune responses to tumor antigens released by conventional therapy.

  7. Radiotherapy combined with TLR7/8 activation induces strong immune responses against gastrointestinal tumors

    PubMed Central

    Tietz, Alexandra; Rahbari, Nuh N.; Bork, Ulrich; Schmidt, Thomas; Kahlert, Christoph; Haberkorn, Uwe; Tomai, Mark A.; Lipson, Kenneth E.; Carretero, Rafael; Weitz, Jürgen; Koch, Moritz; Huber, Peter E.

    2015-01-01

    In addition to local cytotoxic activity, radiotherapy may also elicit local and systemic antitumor immunity, which may be augmented by immunotherapeutic agents including Toll-like receptor (TLR) 7/8 agonists. Here, we investigated the ability of 3M-011 (854A), a TLR7/8 agonist, to boost the antigen-presenting activity of dendritic cells (DC) as an adjuvant to radiotherapy. The combined treatment induced marked local and systemic responses in subcutaneous and orthotopic mouse models of colorectal and pancreatic cancer. In vitro cytotoxicity assays as well as in vivo depletion experiments with monoclonal antibodies identified NK and CD8 T cells as the cell populations mediating the cytotoxic effects of the treatment, while in vivo depletion of CD11c+ dendritic cells (DC) in CD11c-DTR transgenic mice revealed DC as the pivotal immune hub in this setting. The specificity of the immune reaction was confirmed by ELISPOT assays. TLR7/8 agonists therefore seem to be potent adjuvants to radiotherapy, inducing strong local and profound systemic immune responses to tumor antigens released by conventional therapy. PMID:25609199

  8. Effects of oral glutamine supplementation on exercise-induced gastrointestinal permeability and tight junction protein expression.

    PubMed

    Zuhl, Micah N; Lanphere, Kathryn R; Kravitz, Len; Mermier, Christine M; Schneider, Suzanne; Dokladny, Karol; Moseley, Pope L

    2014-01-15

    The objectives of this study are threefold: 1) to assess whether 7 days of oral glutamine (GLN) supplementation reduces exercise-induced intestinal permeability; 2) whether supplementation prevents the proinflammatory response; and 3) whether these changes are associated with upregulation of the heat shock response. On separate occasions, eight human subjects participated in baseline testing and in GLN and placebo (PLA) supplementation trials, followed by a 60-min treadmill run. Intestinal permeability was higher in the PLA trial compared with baseline and GLN trials (0.0604 ± 0.047 vs. 0.0218 ± 0.008 and 0.0272 ± 0.007, respectively; P < 0.05). IκBα expression in peripheral blood mononuclear cells was higher 240 min after exercise in the GLN trial compared with the PLA trial (1.411 ± 0.523 vs. 0.9839 ± 0.343, respectively; P < 0.05). In vitro using the intestinal epithelial cell line Caco-2, we measured effects of GLN supplementation (0, 4, and 6 mM) on heat-induced (37° or 41.8°C) heat shock protein 70 (HSP70), heat shock factor-1 (HSF-1), and occludin expression. HSF-1 and HSP70 levels increased in 6 mM supplementation at 41°C compared with 0 mM at 41°C (1.785 ± 0.495 vs. 0.6681 ± 0.290, and 1.973 ± 0.325 vs. 1.133 ± 0.129, respectively; P < 0.05). Occludin levels increased after 4 mM supplementation at 41°C and 6 mM at 41°C compared with 0 mM at 41°C (1.236 ± 0.219 and 1.849 ± 0.564 vs. 0.7434 ± 0.027, respectively; P < 0.001). GLN supplementation prevented exercise-induced permeability, possibly through HSF-1 activation. PMID:24285149

  9. Method for sizing hollow microspheres

    DOEpatents

    Farnum, E.H.; Fries, R.J.

    1975-10-29

    Hollow Microspheres may be effectively sized by placing them beneath a screen stack completely immersed in an ultrasonic bath containing a liquid having a density at which the microspheres float and ultrasonically agitating the bath.

  10. Endogenous porphyrin distribution induced by 5-aminolaevulinic acid in the tissue layers of the gastrointestinal tract.

    PubMed

    Loh, C S; Vernon, D; MacRobert, A J; Bedwell, J; Bown, S G; Brown, S B

    1993-09-01

    The accumulation of endogenous porphyrins in rats following systemic administration of 5-aminolaevulinic acid (ALA) has been examined to assess the photosensitization characteristics of this technique for photodynamic therapy (PDT) and chemical extraction assays with fluorescence and absorbance detection of the porphyrin content have been carried out. We compared the results obtained using quantitative microfluorimetry on normal gastric and colonic tissues in rats at 0.5, 1, 2, 4 and 6 h and chemically induced duodenal tumours 2 and 4.5 h after intravenous administration of ALA at a dose of 200 mg kg-1. With chemical extraction followed by high performance liquid chromatography analysis, protoporphyrin IX (PpIX) was found to be the predominant porphyrin present, reaching peak levels of several microgrammes per gramme at 2-4 h in each type of tissue; a small amount of coproporphyrin was detected at 0.5 and 2 h in normal gastric mucosa and duodenal tumour respectively. Both the extraction assay and quantitative microfluorimetry showed that the porphyrin fluorescence builds up rapidly in the mucosal layers of the colon and stomach, reaching a maximum at 2 h, whereas lower fluorescence levels were found with a slower rate of accumulation in the corresponding muscularis layers. A significant PpIX content was found in the duodenal tumour, with a maximum of 7.1 micrograms g-1 4.5 h after ALA administration. We conclude that systemic administration of ALA can induce effective tissue sensitization with protoporphyrin IX and appears to be a promising technique for PDT.

  11. The inhibitory effects of alpha(2)-adrenoceptor agonists on gastrointestinal transit during croton oil-induced intestinal inflammation.

    PubMed Central

    Pol, O.; Valle, L.; Ferrer, I.; Puig, M. M.

    1996-01-01

    1. The peripheral effects of alpha(2)-adrenoceptor agonists were investigated in a model of intestinal inflammation induced by intragastric administration of croton oil (CO). Our hypothesis was that inflammation would 'sensitize' adrenoceptors in peripheral and/or central terminals of myenteric and submucous plexus neurones, and enhance systemic effects of alpha(2)-adrenoceptor agonists. 2. Male swiss CD-1 mice, received intragastrically CO (0.05 ml), castor oil (CA, 0.1 ml) or saline (SS) 3 h before the study: gastrointestinal transit (GIT) was evaluated 20 min afterwards with a charcoal meal. The presence of inflammation was assessed by electron microscopy. 3. The intragastric administration of CA or CO caused an increase in GIT and weight loss, but only CO induced an inflammatory response. Both clonidine (imidazoline1/alpha(2)-agonist) and UK-14304 (alpha(2)-agonist) produced dose-related inhibitions of GIT in all groups. During inflammatory diarrhoea (CO), potencies of systemic (s.c.) clonidine and UK-14304 were significantly increased 3.5 and 2.1 times, respectively, while potencies remained unaltered in the presence of diarrhoea without inflammation (CA). The effects were reversed by administration (s.c.) of receptor-specific adrenoceptor antagonists, but not by naloxone. 4. Clonidine was 8.3 (SS) and 2.8 (CO) times more potent when administered intracerebroventricularly (i.c.v.), than when administered s.c. Inflammation of the gut did not alter the potency of i.c.v. clonidine, demonstrating that enhanced effects of s.c. clonidine are mediated by peripheral receptors. During inflammation, i.c.v. efaroxan did not antagonize low doses of s.c. clonidine (ED20 and ED50S), but partially reversed ED80S, further supporting the peripheral effects of the agonists in CO treated animals. 5. The results demonstrate that inflammation of the gut enhances the potency of alpha(2)-adrenoceptor agonists by a peripheral mechanism. The results also suggest that the inflammatory

  12. Insulin delivery through nasal route using thiolated microspheres.

    PubMed

    Nema, Tarang; Jain, Ashish; Jain, Aviral; Shilpi, Satish; Gulbake, Arvind; Hurkat, Pooja; Jain, Sanjay K

    2013-01-01

    The aim of the present study was to investigate the potential of developed thiolated microspheres for insulin delivery through nasal route. In the present study, cysteine was immobilized on carbopol using EDAC. A total of 269.93 µmol free thiol groups per gram polymer were determined. The prepared nonthiolated and thiolated microspheres were studied for particle shape, size, drug content, swellability, mucoadhesion and in vitro insulin release. The thiolated microspheres exhibited higher mucoadhesion due to formation of covalent bonds via disulfide bridges with the mucus gel layer. Drug permeation through goat nasal mucosa of nonthiolated and thiolated microspheres were found as 52.62 ± 2.4% and 78.85 ± 3.1% in 6 h, respectively. Thiolated microspheres bearing insulin showed better reduction in blood glucose level (BGL) in comparison to nonthiolated microspheres as 31.23 ± 2.12% and 75.25 ± 0.93% blood glucose of initial BGL were observed at 6 h after nasal delivery of thiolated and nonthiolated microspheres in streptozotocin-induced diabetic rabbits.

  13. Leukotriene D4 receptor antagonist montelukast alleviates water avoidance stress-induced degeneration of the gastrointestinal mucosa.

    PubMed

    Ersoy, Yasemin; Cikler, Esra; Cetinel, Sule; Sener, Göksel; Ercan, Feriha

    2008-03-01

    We investigated the role of montelukast (ML), a cysteinyl leukotriene-1 receptor antagonist, on the water avoidance stress (WAS)-induced degeneration of the rat gastric, ileal and colonic mucosa. One group of Wistar albino rats were exposed to chronic WAS (WAS group) 2h daily for 5 days. Another group was administered ML (10mg/kg; i.p.; WAS+ML group) following every WAS exposure for 5 days. Control rats were injected with the vehicle solution only. The stomach, ileum and colon were dissected and investigated for histopathological changes with a light microscope as well as for topographical changes with a scanning electron microscope. The levels of malondialdehyde (MDA, a biomarker of oxidative damage) and glutathione (GSH, a biomarker of protective oxidative injury) were also determined in all dissected tissues. In the WAS group, the stomach epithelium showed ulceration in some areas, dilatations of the gastric glands, degeneration of gastric glandular cells, and prominent congestion of the capillaries. In a similar fashion, degenerated epithelium and severe vascular congestions were observed in the ileum and colon. In all the tissues dense inflammatory cell infiltration and mast cell degranulation in mucosa were observed. The levels of MDA were significantly increased whereas those of GSH were significantly decreased in all test tissues in the WAS group compared to the control group. The morphology of gastric, ileal and colonic mucosa in WAS+ML group showed a significant amelioration showing a reduction in inflammatory cell infiltration and mast cell degranulation. Increased MDA and decreased GSH levels in the WAS group were also ameliorated with ML treatment. Based on the results, ML supplement seems attenuated inflammatory effects of WAS induction in gastrointestinal mucosa.

  14. Method for preparing hollow metal oxide microsphere

    DOEpatents

    Schmitt, C.R.

    1974-02-12

    Hollow refractory metal oxide microspheres are prepared by impregnating resinous microspheres with a metallic compound, drying the impregnated microspheres, heating the microspheres slowly to carbonize the resin, and igniting the microspheres to remove the carbon and to produce the metal oxide. Zirconium oxide is given as an example. (Official Gazette)

  15. Mechanistic evaluation of the glucose-induced reduction in initial burst release of octreotide acetate from poly(D,L-lactide-co-glycolide) microspheres.

    PubMed

    Wang, Juan; Wang, Barbara M; Schwendeman, Steven P

    2004-05-01

    One major obstacle for development of injectable biodegradable microspheres for controlled peptide and protein delivery is the high initial burst of drug release occurring over the first day of incubation. We describe here the significant reduction in initial burst release of a highly water-soluble model peptide, octreotide acetate, from poly(D,L-lactide-co-glycolide) microspheres by the co-encapsulation of a small amount of glucose (e.g., 0.2%w/w), i.e., from 30+/-20% burst - glucose to 8+/-3% + glucose (mean+/-SD, n=4). This reduction is unexpected since hydrophilic additives are known to increase porosity of microspheres, causing an increase in permeability to mass transport and a higher burst. Using the double emulsion-solvent evaporation method of encapsulation, the effect of glucose on initial burst in an acetate buffer pH 4 was found to depend on polymer concentration, discontinuous phase/continuous phase ratio, and glucose content. Extensive characterization studies were performed on two microsphere batches, +/-0.2% glucose, to elucidate the mechanism of this effect. However, no significant difference was observed with respect to specific surface area, porosity, internal and external morphology and drug distribution. Continuous monitoring of the first 24-h release of octreotide acetate from these two batches disclosed that even though their starting release rates were close, the microspheres + glucose exhibited a much lower release rate between 0.2 and 24h compared to those - glucose. The microspheres + glucose showed a denser periphery and a reduced water uptake at the end of 24-h release, indicating decreased permeability. However, this effect at times was offset as glucose content was further increased to 1%, causing an increase in surface area and porosity. In summary, we conclude that the effect of glucose on initial burst are determined by two factors: (1) increased initial burst due to increased osmotic pressure during encapsulation and drug release

  16. SRNL POROUS WALL GLASS MICROSPHERES

    SciTech Connect

    Wicks, G; Leung Heung, L; Ray Schumacher, R

    2008-04-15

    The Savannah River National Laboratory (SRNL) has developed a new medium for storage of hydrogen and other gases. This involves fabrication of thin, Porous Walled, Hollow Glass Microspheres (PW-HGMs), with diameters generally in the range of 1 to several hundred microns. What is unique about the glass microballons is that porosity has been induced and controlled within the thin, one micron thick walls, on the scale of 10 to several thousand Angstroms. This porosity results in interesting properties including the ability to use these channels to fill the microballons with special absorbents and other materials, thus providing a contained environment even for reactive species. Gases can now enter the microspheres and be retained on the absorbents, resulting in solid-state and contained storage of even reactive species. Also, the porosity can be altered and controlled in various ways, and even used to filter mixed gas streams within a system. SRNL is involved in about a half dozen different programs involving these PW-HGMs and an overview of some of these activities and results emerging are presented.

  17. Uvangoletin induces mitochondria-mediated apoptosis in HL-60 cells in vitro and in vivo without adverse reactions of myelosuppression, leucopenia and gastrointestinal tract disturbances.

    PubMed

    Zheng, Zhuanzhen; Qiao, Zhenhua; Gong, Rong; Wang, Yalin; Zhang, Yiqun; Ma, Yanping; Zhang, Li; Lu, Yujin; Jiang, Bo; Li, Guoxia; Dong, Chunxia; Chen, Wenliang

    2016-02-01

    This study investigated the cytotoxic effect of uvangoletin on HL-60 cells, and the effects of uvangoletin on myelosuppression, leucopenia, gastrointestinal tract disturbances and the possible cytotoxic mechanisms by using CCK-8, flow cytometry, western blot, xenograft, cyclophosphamide-induced leucopenia, copper sulfate-induced emesis and ethanol-induced gastric mucosal lesions assays. The results of CCK-8, flow cytometry and western blot assays indicated that uvangoletin showed the cytotoxic effect on HL-60 cells and induced the apoptosis of HL-60 cells by downregulating the expression levels of anti-apoptotic proteins (Survivin, Bcl-xl and Bcl-2), upregulating the expression levels of pro-apoptotic proteins (Smac, Bax, Bad, c-caspase-3 and c-caspase-9), and promoting the release of cytochrome c from mitochondria to cytoplasm. Further, the results of xenograft assay suggested that uvangoletin inhibited the HL-60-induced tumor growth without adverse effect on body weight of nude mice in vivo by regulating the expression levels of above apoptotic proteins. The results indicated that the reductions of WBCs count and thighbone marrow granulocytes percentage in cyclophosphamide-induced leucopenia assay, the incubation period and number of emesis in copper sulfate-induced emesis assay and the gastric mucosal lesions in ethanol-induced gastric mucosal lesions assay were not exacerbated or reversed by uvangoletin. In conclusion, the research preliminarily indicated that uvangoletin induced apoptosis of HL-60 cells in vitro and in vivo without adverse reactions of myelosuppression, leucopenia and gastrointestinal tract disturbances, and the pro-apoptotic mechanisms may be related to mitochondria-mediated apoptotic pathway. PMID:26717974

  18. Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells.

    PubMed

    Chen, Wei; Xu, Yang; Zhang, Lingxia; Li, Ya; Zheng, Xiaodong

    2016-01-01

    Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells.

  19. Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells.

    PubMed

    Chen, Wei; Xu, Yang; Zhang, Lingxia; Li, Ya; Zheng, Xiaodong

    2016-01-01

    Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells. PMID:26788245

  20. Wild Raspberry Subjected to Simulated Gastrointestinal Digestion Improves the Protective Capacity against Ethyl Carbamate-Induced Oxidative Damage in Caco-2 Cells

    PubMed Central

    Chen, Wei; Xu, Yang; Zhang, Lingxia; Li, Ya; Zheng, Xiaodong

    2016-01-01

    Ethyl carbamate (EC), a probable human carcinogen, occurs widely in many fermented foods. Previous studies indicated that EC-induced cytotoxicity was associated with oxidative stress. Wild raspberries are rich in polyphenolic compounds, which possess potent antioxidant activity. This study was conducted to investigate the protective effect of wild raspberry extracts produced before (RE) and after in vitro simulated gastrointestinal digestion (RD) on EC-induced oxidative damage in Caco-2 cells. Our primary data showed that ethyl carbamate could result in cytotoxicity and genotoxicity in Caco-2 cells and raspberry extract after digestion (RD) may be more effective than that before digestion (RE) in attenuating toxicity caused by ethyl carbamate. Further investigation by fluorescence microscope revealed that RD may significantly ameliorate EC-induced oxidative damage by scavenging the overproduction of intracellular reactive oxygen species (ROS), maintaining mitochondrial function and preventing glutathione (GSH) depletion. In addition, HPLC-ESI-MS results showed that the contents of identified polyphenolic compounds (esculin, kaempferol O-hexoside, and pelargonidin O-hexoside) were remarkably increased after digestion, which might be related to the better protective effect of RD. Overall, our results demonstrated that raspberry extract undergoing simulated gastrointestinal digestion may improve the protective effect against EC-induced oxidative damage in Caco-2 cells. PMID:26788245

  1. Polyvinyl pyridine microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Gupta, Amitava (Inventor); Volksen, Willi (Inventor)

    1980-01-01

    Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.

  2. Polyvinyl pyridine microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Gupta, Amitava (Inventor); Volksen, Willi (Inventor)

    1979-01-01

    Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.

  3. Doped zinc oxide microspheres

    DOEpatents

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  4. Doped zinc oxide microspheres

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-12-14

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  5. Microsphere insulation systems

    NASA Technical Reports Server (NTRS)

    Allen, Mark S. (Inventor); Willen, Gary S. (Inventor); Mohling, Robert A. (Inventor)

    2005-01-01

    A new insulation system is provided that contains microspheres. This insulation system can be used to provide insulated panels and clamshells, and to insulate annular spaces around objects used to transfer, store, or transport cryogens and other temperature-sensitive materials. This insulation system provides better performance with reduced maintenance than current insulation systems.

  6. Fusion microsphere targets

    SciTech Connect

    Koo, J.C.

    1980-07-28

    It was shown that a microsphere within the structure limitations is hydrodynamically stable. To insure its perfect formation, the initial chemical compositions must have a blowing capability, more important, the resultant liquid compositions must also have sufficient surface tension and low viscosity.

  7. NSAID-induced gastrointestinal damage. Epidemiology, risk and prevention, with an evaluation of the role of misoprostol. An Asia-Pacific perspective and consensus.

    PubMed

    Champion, G D; Feng, P H; Azuma, T; Caughey, D E; Chan, K H; Kashiwazaki, S; Liu, H C; Nasution, A R; Nobunaga, M; Prichanond, S; Torralba, T P; Udom, V; Utis, D; Wang, S R; Wong, W S; Yang, D J; Yoo, M C

    1997-01-01

    The problem of nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal toxicity was reviewed by members of the Asia Pacific League of Associations for Rheumatology (APLAR) in a consensus conference in September 1992. This paper by the participants presents the consensus conclusions incorporating knowledge from recent publications. There had been a high level of concern that much of the toxicity had resulted from extensive and indiscriminate prescribing of NSAIDs. The implementation of evidence-based guidelines was considered likely to be able to effect a substantial reduction in toxicity without significant loss of overall therapeutic benefit. The evidence from which such guidelines could be developed is critically appraised.

  8. Porous microsphere and its applications

    PubMed Central

    Cai, Yunpeng; Chen, Yinghui; Hong, Xiaoyun; Liu, Zhenguo; Yuan, Weien

    2013-01-01

    Porous microspheres have drawn great attention in the last two decades for their potential applications in many fields, such as carriers for drugs, absorption and desorption of substances, pulmonary drug delivery, and tissue regeneration. The application of porous microspheres has become a feasible way to address existing problems. In this essay, we give a brief introduction of the porous microsphere, its characteristics, preparation methods, applications, and a brief summary of existing problems and research tendencies. PMID:23515359

  9. Corneal Confocal Microscopy Detects Small Fibre Neuropathy in Patients with Upper Gastrointestinal Cancer and Nerve Regeneration in Chemotherapy Induced Peripheral Neuropathy.

    PubMed

    Ferdousi, Maryam; Azmi, Shazli; Petropoulos, Ioannis Nikolaos; Fadavi, Hassan; Ponirakis, Georgios; Marshall, Andrew; Tavakoli, Mitra; Malik, Imaan; Mansoor, Wasat; Malik, Rayaz Ahmed

    2015-01-01

    There are multiple neurological complications of cancer and its treatment. This study assessed the utility of the novel non-invasive ophthalmic technique of corneal confocal microscopy in identifying neuropathy in patients with upper gastrointestinal cancer before and after platinum based chemotherapy. In this study, 21 subjects with upper gastrointestinal (oesophageal or gastric) cancer and 21 healthy control subjects underwent assessment of neuropathy using the neuropathy disability score, quantitative sensory testing for vibration perception threshold, warm and cold sensation thresholds, cold and heat induced pain thresholds, nerve conduction studies and corneal confocal microscopy. Patients with gastro-oesophageal cancer had higher heat induced pain (P = 0.04) and warm sensation (P = 0.03) thresholds with a significantly reduced sural sensory (P<0.01) and peroneal motor (P<0.01) nerve conduction velocity, corneal nerve fibre density (CNFD), nerve branch density (CNBD) and nerve fibre length (CNFL) (P<0.0001). Furthermore, CNFD correlated significantly with the time from presentation with symptoms to commencing chemotherapy (r = -0.54, P = 0.02), and CNFL (r = -0.8, P<0.0001) and CNBD (r = 0.63, P = 0.003) were related to the severity of lymph node involvement. After the 3rd cycle of chemotherapy, there was no change in any measure of neuropathy, except for a significant increase in CNFL (P = 0.003). Corneal confocal microscopy detects a small fibre neuropathy in this cohort of patients with upper gastrointestinal cancer, which was related to disease severity. Furthermore, the increase in CNFL after the chemotherapy may indicate nerve regeneration.

  10. Corneal Confocal Microscopy Detects Small Fibre Neuropathy in Patients with Upper Gastrointestinal Cancer and Nerve Regeneration in Chemotherapy Induced Peripheral Neuropathy

    PubMed Central

    Ferdousi, Maryam; Azmi, Shazli; Petropoulos, Ioannis Nikolaos; Fadavi, Hassan; Ponirakis, Georgios; Marshall, Andrew; Tavakoli, Mitra; Malik, Imaan; Mansoor, Wasat; Malik, Rayaz Ahmed

    2015-01-01

    There are multiple neurological complications of cancer and its treatment. This study assessed the utility of the novel non-invasive ophthalmic technique of corneal confocal microscopy in identifying neuropathy in patients with upper gastrointestinal cancer before and after platinum based chemotherapy. In this study, 21 subjects with upper gastrointestinal (oesophageal or gastric) cancer and 21 healthy control subjects underwent assessment of neuropathy using the neuropathy disability score, quantitative sensory testing for vibration perception threshold, warm and cold sensation thresholds, cold and heat induced pain thresholds, nerve conduction studies and corneal confocal microscopy. Patients with gastro-oesophageal cancer had higher heat induced pain (P = 0.04) and warm sensation (P = 0.03) thresholds with a significantly reduced sural sensory (P<0.01) and peroneal motor (P<0.01) nerve conduction velocity, corneal nerve fibre density (CNFD), nerve branch density (CNBD) and nerve fibre length (CNFL) (P<0.0001). Furthermore, CNFD correlated significantly with the time from presentation with symptoms to commencing chemotherapy (r = -0.54, P = 0.02), and CNFL (r = -0.8, P<0.0001) and CNBD (r = 0.63, P = 0.003) were related to the severity of lymph node involvement. After the 3rd cycle of chemotherapy, there was no change in any measure of neuropathy, except for a significant increase in CNFL (P = 0.003). Corneal confocal microscopy detects a small fibre neuropathy in this cohort of patients with upper gastrointestinal cancer, which was related to disease severity. Furthermore, the increase in CNFL after the chemotherapy may indicate nerve regeneration. PMID:26430773

  11. Functional magnetic microspheres

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Landel, Robert F. (Inventor)

    1981-01-01

    Functional magnetic particles are formed by dissolving a mucopolysaccharide such as chitosan in acidified aqueous solution containing a mixture of ferrous chloride and ferric chloride. As the pH of the solution is raised magnetite is formed in situ in the solution by raising the pH. The dissolved chitosan is a polyelectrolyte and forms micelles surrounding the granules at pH of 8-9. The chitosan precipitates on the granules to form microspheres containing the magnetic granules. On addition of the microspheres to waste aqueous streams containing dissolved ions, the hydroxyl and amine functionality of the chitosan forms chelates binding heavy metal cations such as lead, copper, and mercury and the chelates in turn bind anions such as nitrate, fluoride, phosphate and borate.

  12. Trading polymeric microspheres: exchanging DNA molecules via microsphere interaction.

    PubMed

    Morimoto, Nobuyuki; Muramatsu, Kanna; Nomura, Shin-ichiro M; Suzuki, Makoto

    2015-04-01

    A new class of artificial molecular transport system is constructed by polymeric microspheres. The microspheres are prepared by self-assembly of poly(ethylene glycol)-block-poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate), PEG-b-PDMAPS, by intermolecular dipole-dipole interaction of sulfobetaine side chains in water. Below the upper critical solution temperature (UCST) of PEG-b-PDMAPS, the microspheres (∼1μm) interact with other microspheres by partial and transit fusion. In order to apply the interaction between microspheres, a 3'-TAMRA-labeled single-stranded DNA oligomer (ssDNA) is encapsulated into a PEG-b-PDMAPS microsphere by thermal treatment. The exchange of ssDNA between microspheres is confirmed by fluorescence resonance energy transfer (FRET) quenching derived from double-stranded formation with complementary 5'-BHQ-2-labeled ssDNA encapsulated in PEG-b-PDMAPS microspheres. The exchange rate of ssDNA is controllable by tuning the composition of the polymer. The contact-dependent transport of molecules can be applied in the areas of microreactors, sensor devices, etc. PMID:25731098

  13. Trading polymeric microspheres: exchanging DNA molecules via microsphere interaction.

    PubMed

    Morimoto, Nobuyuki; Muramatsu, Kanna; Nomura, Shin-ichiro M; Suzuki, Makoto

    2015-04-01

    A new class of artificial molecular transport system is constructed by polymeric microspheres. The microspheres are prepared by self-assembly of poly(ethylene glycol)-block-poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate), PEG-b-PDMAPS, by intermolecular dipole-dipole interaction of sulfobetaine side chains in water. Below the upper critical solution temperature (UCST) of PEG-b-PDMAPS, the microspheres (∼1μm) interact with other microspheres by partial and transit fusion. In order to apply the interaction between microspheres, a 3'-TAMRA-labeled single-stranded DNA oligomer (ssDNA) is encapsulated into a PEG-b-PDMAPS microsphere by thermal treatment. The exchange of ssDNA between microspheres is confirmed by fluorescence resonance energy transfer (FRET) quenching derived from double-stranded formation with complementary 5'-BHQ-2-labeled ssDNA encapsulated in PEG-b-PDMAPS microspheres. The exchange rate of ssDNA is controllable by tuning the composition of the polymer. The contact-dependent transport of molecules can be applied in the areas of microreactors, sensor devices, etc.

  14. Pentadecapeptide BPC 157 positively affects both non-steroidal anti-inflammatory agent-induced gastrointestinal lesions and adjuvant arthritis in rats.

    PubMed

    Sikiric, P; Seiwerth, S; Grabarevic, Z; Rucman, R; Petek, M; Jagic, V; Turkovic, B; Rotkvic, I; Mise, S; Zoricic, I; Konjevoda, P; Perovic, D; Simicevic, V; Separovic, J; Hanzevacki, M; Ljubanovic, D; Artukovic, B; Bratulic, M; Tisljar, M; Rekic, B; Gjurasin, M; Miklic, P; Buljat, G

    1997-01-01

    Besides a superior protection of the pentadecapeptide BPC 157 (an essential fragment of an organoprotective gastric juice peptide BPC) against different gastrointestinal and liver lesions, an acute anti-inflammatory and analgetic activity was also noted. Consequently, its effect on chronic inflammation lesions, such as adjuvant arthritis, and non-steroidal anti-inflammatory agents (NSAIAs)-induced gastrointestinal lesions was simultaneously studied in rats. In gastrointestinal lesions (indomethacin (30 mg/kg s.c.), aspirin (400 mg/kg i.g.) and diclofenac (125 mg/kg i.p.) studies, BPC 157 (10 micrograms or 10 ng/kg i.p.) was regularly given simultaneously and/or 1 h prior to drug application (indomethacin). In the adjuvant arthritis (tail-application of 0.2 mL of Freund's adjuvant) studies (14 days, 30 days, 1 year) BPC 157 (10 micrograms or 10 ng/kg i.p.), it was given as a single application (at 1 h either before or following the application of Freund's adjuvant) or in a once daily regimen (0-14th day, 14-30th day, 14th day-1 year). Given with the investigated NSAIAs, BPC 157 consistently reduced the otherwise prominent lesions in the stomach of the control rats, as well as the lesions in the small intestine in the indomethacin groups. In the adjuvant arthritis studies, the lesion's development seems to be considerably reduced after single pentadecapeptide medication, and even more attenuated in rats daily treated with BPC 157. As a therapy of already established adjuvant arthritis, its salutary effect consistently appeared already after 2 weeks of medication and it could be clearly seen also after 1 year of application. Taking together all these results, the data likely point to a special anti-inflammatory and mucosal integrity protective effect. PMID:9403784

  15. Protocol for a randomised control trial of methylnaltrexone for the treatment of opioid-induced constipation and gastrointestinal stasis in intensive care patients (MOTION)

    PubMed Central

    Patel, Parind B; Brett, Stephen J; O'Callaghan, David; Anjum, Aisha; Cross, Mary; Warwick, Jane; Gordon, Anthony C

    2016-01-01

    Introduction Gastrointestinal dysmotility and constipation are common problems in intensive care patients. The majority of critical care patients are sedated with opioids to facilitate tolerance of endotracheal tubes and mechanical ventilation, which inhibit gastrointestinal motility and lead to adverse outcomes. Methylnaltrexone is a peripheral opioid antagonist that does not cross the blood–brain barrier and can reverse the peripheral side effects of opioids without affecting the desired central properties. This trial will investigate whether methylnaltrexone can reverse opioid-induced constipation and gastrointestinal dysmotility. Methods This is a single-centre, multisite, double-blind, randomised, placebo-controlled trial. 84 patients will be recruited from 4 intensive care units (ICUs) within Imperial College Healthcare NHS Trust. Patients will receive intravenous methylnaltrexone or placebo on a daily basis if they are receiving opioid infusion to facilitate mechanical ventilation and have not opened their bowels for 48 hours. All patients will receive standard laxatives as per the clinical ICU bowel protocol prior to randomisation. The primary outcome of the trial will be time to significant rescue-free laxation following randomisation. Secondary outcomes will include tolerance of enteral feed, gastric residual volumes, incidence of pneumonia, blood stream and Clostridium difficile infection, and any reversal of central opioid effects. Ethics and dissemination The trial protocol, the patient/legal representative information sheets and consent forms have been reviewed and approved by the Harrow Research Ethics Committee (REC Reference 14/LO/2004). An independent Trial Steering Committee and Data Monitoring Committee are in place, with patient representation. On completion, the trial results will be published in peer-reviewed journals and presented at national and international scientific meetings. Trial registration number 2014-004687-37; Pre

  16. Is gastrointestinal dysfunction induced by gastric cancer peritoneal metastasis relevant to impairment of interstitial cells of Cajal?

    PubMed

    Zheng, Hongqun; He, Yan; Tong, Jinxue; Sun, Lingyu; Yang, Dongdong; Li, Huaming; Ao, Ning; Jin, Xiaoming; Zhang, Qifan

    2011-03-01

    Although impaired gastrointestinal motility from gastric cancer peritoneal metastasis (GCPM) causes extraordinary pain, its cause is unclear. Interstitial cells of Cajal (ICC) are apparently pacemaker cells, and their loss could cause motor dysfunction. In this study, we developed a mouse model for GCPM, and investigated electrophysiological changes in the small intestine and attendant changes in ICC. We found decreased ICC and disrupted electrical rhythm in the model. Pathologic ICC changes were well described. Cancer peritoneal metastasis may impair intestinal myoelectrical activity by damaging ICC and ICC networks. Interstitial cells of Cajal will be a target of palliative treatment and merit further study. PMID:21207119

  17. Metal containing polymeric functional microspheres

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Molday, Robert S. (Inventor)

    1979-01-01

    Polymeric functional microspheres containing metal or metal compounds are formed by addition polymerization of a covalently bondable olefinic monomer such as hydroxyethylmethacrylate in the presence of finely divided metal or metal oxide particles, such as iron, gold, platinum or magnetite, which are embedded in the resulting microspheres. The microspheres can be covalently bonded to chemotherapeutic agents, antibodies, or other proteins providing a means for labeling or separating labeled cells. Labeled cells or microspheres can be concentrated at a specific body location such as in the vicinity of a malignant tumor by applying a magnetic field to the location and then introducing the magnetically attractable microspheres or cells into the circulatory system of the subject. Labeled cells can be separated from a cell mixture by applying a predetermined magnetic field to a tube in which the mixture is flowing. After collection of the labeled cells, the magnetic field is discontinued and the labeled sub-cell population recovered.

  18. Immunofluorescence detection methods using microspheres

    NASA Astrophysics Data System (ADS)

    Szurdoki, Ferenc; Michael, Karri L.; Agrawal, Divya; Taylor, Laura C.; Schultz, Sandra L.; Walt, David R.

    1999-01-01

    Microsphere-based immunoassays were devised for compounds of agricultural and biomedical interest (e.g., digoxin, theophylline, and zearalenone). Commercially available microspheres with surface functional groups for chemical derivatization were used as solid carriers. After immobilizing the target substances, the surface of the haptenized microspheres was blocked by a protein to reduce aspecific binding. Competitive immunoassays were performed using the functionalized microspheres and antibodies labeled with horseradish peroxidase. Immunofluorescence signal amplification was achieved by enzyme-catalyzed reporter deposition (CARD). An epifluorescence microscope, a CCD camera interfaced with a computer, and microscopy image analysis software were employed for quantitative detection of fluorescent light emitted from individual microspheres. Integration of several such immunoassays and application of an optical encoding method enabled multianalyte determination. These immunoassays can also be utilized in an immunosensor array format. This immunoarray format could facilitate miniaturization and automation of multianalyte immunoassays.

  19. Surface characterization by atomic force microscopy of sterilized PLGA microspheres.

    PubMed

    Dorati, Rossella; Patrini, Maddalena; Perugini, Paola; Pavanetto, Franca; Stella, Angiolino; Modena, Tiziana; Genta, Ida; Conti, Bice

    2006-03-01

    Atomic force microscopy (AFM) is recognized a suitable and powerful technique for surface and morphological analysis. Even if until now this technique has not been frequently used in the pharmaceutical field, it can contribute to an accurate morphologic characterization of microspheres and nanospheres. In this work, atomic force microscopy has been used to perform the surface characterization of sterilized microspheres. The aim is to investigate the morphologic modifications induced by gamma irradiation on poly(lactide-co-glycolide) microspheres loaded with ovalbumin and to compare the results obtained by AFM to those obtained by scanning electron microscopy (SEM). The results obtained show that, with respect to SEM, AFM can give some additional information regarding the modifications induced by gamma-irradiation on microspheres surface morphology. The significant changes in surface roughness after irradiation are indicative of damage due to gamma-irradiation. The unchanged surface roughness values calculated for microspheres containing PEG in their matrix, suggest that this polymer exerts a protective effect towards gamma-irradiation. PMID:16754370

  20. Mitigation of indomethacin-induced gastrointestinal damages in fat-1 transgenic mice via gate-keeper action of ω-3-polyunsaturated fatty acids

    PubMed Central

    Han, Young-Min; Park, Jong-Min; Kang, Jing X.; Cha, Ji-Young; Lee, Ho-Jae; Jeong, Migeyong; Go, Eun-Jin; Hahm, Ki Baik

    2016-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) damage the gastrointestinal (GI) epithelial cell membranes by inducing several signals through lipid raft organization after membrane incorporation, whereas ω-3 polyunsaturated fatty acids (PUFAs) relieve inflammation, reduce oxidative stress, and provide cytoprotection, consequent to lipid raft disorganization. Therefore, we hypothesized that ω-3 PUFAs can protect the GI from NSAID-induced damages by initiating the gatekeeper action of cell membranes, subsequent to anti-inflammatory and anti-oxidative actions. Administration of indomethacin (IND) leads to the formation of lipid rafts and activation of caveolin-1; however, no such observations were made upon co-administration of eicosapentaenoic acid (EPA) and IND. In addition, the EPA-induced lipid raft disorganization, caveolin-1 inactivation, and cellular cytotoxicity were inhibited when target cells were knocked-out using G-protein coupled receptor 120 (GPR 120). EPA significantly attenuated IND-induced oxidative damage and apoptosis. IND administration induced significant ulceration, bleeding, and oedema in the stomach or small intestine of wild-type (WT) mice; however, such severe damages to the GI significantly decreased in fat-1 transgenic (TG) mice (P < 0.001), which exhibited decreased cyclooxygenase-2 expression and apoptosis, decreased interleukin-1β and FAS concentrations, and increased heme oxygenase-1 concentration. Our study indicates that the gatekeeper function of ω-3 PUFAs improves GI safety when administered with NSAID. PMID:27658533

  1. In situ fabrication of a perfect Pd/ZnO@ZIF-8 core-shell microsphere as an efficient catalyst by a ZnO support-induced ZIF-8 growth strategy

    NASA Astrophysics Data System (ADS)

    Lin, Lu; Zhang, Tong; Liu, Haiou; Qiu, Jieshan; Zhang, Xiongfu

    2015-04-01

    Controllable encapsulation of nanoparticles with metal organic frameworks (MOFs) has been an efficient way to impart the unique chemical and physical properties of the nanoparticles to metal organic frameworks and create new types of multifunctional MOF core-shell materials with enhanced properties. Here, a novel ZnO support-induced encapsulation strategy is reported to efficiently fabricate a Pd/ZnO@ZIF-8 core-shell catalyst, with Pd/ZnO as the core and ZIF-8 as the shell. The novel synthesis procedure involves first loading Pd nanoparticles onto the surface of the ZnO microsphere to form a Pd/ZnO core and then coating the core with a layer of defect-free ZIF-8 shell via ZnO-induced in situ ZIF-8 growth to obtain the Pd/ZnO@ZIF-8 core-shell catalyst. It was crucial that the ZIF-8 was in situ formed from the ZnO core in an ethanol solution only containing 2-methylimidazole under mild conditions. This strategy allowed for the growth of ZIF-8 right on the surface of Pd/ZnO via the reaction between ZnO and the 2-methylimidazole ligands, and thus avoided the random deposition of ZIF-8 crystals on the Pd/ZnO core as in the case of the conventional ZIF-8 synthesis solution. Furthermore, use of ethanol as the solvent also favored achievement of the well-defined Pd/ZnO@ZIF-8 structure, since the ethanol solution of 2-methylimidazole was able to keep the balance between ZnO dissolution and ZIF-8 formation. The as-prepared Pd/ZnO@ZIF-8 core-shell microsphere as an efficient catalyst displayed excellent performance in terms of size-selectivity, stability and anti-poisoning in the liquid hydrogenations of alkenes.

  2. In situ fabrication of a perfect Pd/ZnO@ZIF-8 core-shell microsphere as an efficient catalyst by a ZnO support-induced ZIF-8 growth strategy.

    PubMed

    Lin, Lu; Zhang, Tong; Liu, Haiou; Qiu, Jieshan; Zhang, Xiongfu

    2015-05-01

    Controllable encapsulation of nanoparticles with metal organic frameworks (MOFs) has been an efficient way to impart the unique chemical and physical properties of the nanoparticles to metal organic frameworks and create new types of multifunctional MOF core-shell materials with enhanced properties. Here, a novel ZnO support-induced encapsulation strategy is reported to efficiently fabricate a Pd/ZnO@ZIF-8 core-shell catalyst, with Pd/ZnO as the core and ZIF-8 as the shell. The novel synthesis procedure involves first loading Pd nanoparticles onto the surface of the ZnO microsphere to form a Pd/ZnO core and then coating the core with a layer of defect-free ZIF-8 shell via ZnO-induced in situ ZIF-8 growth to obtain the Pd/ZnO@ZIF-8 core-shell catalyst. It was crucial that the ZIF-8 was in situ formed from the ZnO core in an ethanol solution only containing 2-methylimidazole under mild conditions. This strategy allowed for the growth of ZIF-8 right on the surface of Pd/ZnO via the reaction between ZnO and the 2-methylimidazole ligands, and thus avoided the random deposition of ZIF-8 crystals on the Pd/ZnO core as in the case of the conventional ZIF-8 synthesis solution. Furthermore, use of ethanol as the solvent also favored achievement of the well-defined Pd/ZnO@ZIF-8 structure, since the ethanol solution of 2-methylimidazole was able to keep the balance between ZnO dissolution and ZIF-8 formation. The as-prepared Pd/ZnO@ZIF-8 core-shell microsphere as an efficient catalyst displayed excellent performance in terms of size-selectivity, stability and anti-poisoning in the liquid hydrogenations of alkenes.

  3. Enteropathogenic Escherichia coli protein secretion is induced in response to conditions similar to those in the gastrointestinal tract.

    PubMed Central

    Kenny, B; Abe, A; Stein, M; Finlay, B B

    1997-01-01

    The pathogenicity of enteropathogenic Escherichia coli (EPEC) is associated with the expression and secretion of specific bacterial factors. EspB is one such secreted protein which is required to trigger host signaling pathways resulting in effacement of microvilli and cytoskeletal rearrangements. These events presumably contribute to the ensuing diarrhea associated with EPEC infections. EPEC encounters several environmental changes and stimuli during its passage from the external environment into the host gastrointestinal tract. In this paper we show that the secretion of EspB is subject to environmental regulation, and maximal secretion occurs under conditions reminiscent of those in the gastrointestinal tract. Thus, secretion is maximal at 37 degrees C, pH 7, and physiological osmolarity. In addition, maximal secretion requires the presence of sodium bicarbonate and calcium and is stimulated by millimolar concentrations of Fe(NO3)3. The secretion of the four other EPEC-secreted proteins appears to be modulated in a manner similar to that of EspB. Our results also show that secretion is not dependent on CO2, as originally reported by Haigh et al. (FEMS Microbiol. Lett. 129: 63-67, 1995), but that CO2 more likely acts as a component of the medium buffering system, since CO2 dependence was abolished by the use of alternative buffers. PMID:9199427

  4. Effects of early enteral nutrition on the gastrointestinal motility and intestinal mucosal barrier of patients with burn-induced invasive fungal infection

    PubMed Central

    Zhang, Yu; Gu, Fang; Wang, Fengxian; Zhang, Yuanda

    2016-01-01

    Objective: To evaluate the effects of early enteral nutrition on the gastrointestinal motility and intestinal mucosal barrier of patients with burn-induced invasive fungal infection. Methods: A total of 120 patients with burn-induced invasive fungal infection were randomly divided into an early enteral nutrition (EN) group and a parenteral nutrition (PN) group (n=60). The patients were given nutritional support intervention for 14 days, and the expression levels of serum transferrin, albumin, total protein, endotoxin, D-lactic acid and inflammatory cytokines were detected on the 1st, 7th and 14th days respectively. Results: As the treatment progressed, the levels of serum transferrin, albumin and total protein of the EN group were significantly higher than those of the PN group (P<0.05), while the levels of serum endotoxin and D-lactic acid of the form group were significantly lower (P<0.05). After treatment, the expression levels of IL-6 and TNF-α were decreased in the EN group, which were significantly different from those of the PN group (P<0.05). During treatment, the incidence rates of complications such as abdominal distension, diarrhea, sepsis, nausea, vomiting and gastric retention were similar. The mean healing time of wound surface was 9.34±0.78 days in the EN group and 12.46±2.19 days in the PN group, i.e. such time of the former was significantly shorter than that of the latter (P<0.05). Conclusion: Treating patients having burn-induced invasive fungal infection by early enteral nutrition support with arginine can safely alleviate malnutrition and stress reaction, strengthen cellular immune function and promote wound healing, thereby facilitating the recovery of gastrointestinal motility and the function of intestinal mucosal barrier. PMID:27375697

  5. Gastrointestinal food allergies.

    PubMed

    Heine, Ralf G

    2015-01-01

    Gastrointestinal food allergies present during early childhood with a diverse range of symptoms. Cow's milk, soy and wheat are the three most common gastrointestinal food allergens. Several clinical syndromes have been described, including food protein-induced enteropathy, proctocolitis and enterocolitis. In contrast with immediate, IgE-mediated food allergies, the onset of gastrointestinal symptoms is delayed for at least 1-2 hours after ingestion in non-IgE-mediated allergic disorders. The pathophysiology of these non-IgE-mediated allergic disorders is poorly understood, and useful in vitro markers are lacking. The results of the skin prick test or measurement of the food-specific serum IgE level is generally negative, although low-positive results may occur. Diagnosis therefore relies on the recognition of a particular clinical phenotype as well as the demonstration of clear clinical improvement after food allergen elimination and the re-emergence of symptoms upon challenge. There is a significant clinical overlap between non-IgE-mediated food allergy and several common paediatric gastroenterological conditions, which may lead to diagnostic confusion. The treatment of gastrointestinal food allergies requires the strict elimination of offending food allergens until tolerance has developed. In breast-fed infants, a maternal elimination diet is often sufficient to control symptoms. In formula-fed infants, treatment usually involves the use an extensively hydrolysed or amino acid-based formula. Apart from the use of hypoallergenic formulae, the solid diets of these children also need to be kept free of specific food allergens, as clinically indicated. The nutritional progress of infants and young children should be carefully monitored, and they should undergo ongoing, regular food protein elimination reassessments by cautious food challenges to monitor for possible tolerance development.

  6. Covalent TiO(2)/pectin microspheres with Fe(3)O(4) nanoparticles for magnetic field-modulated drug delivery.

    PubMed

    da Silva, Elisangela P; Sitta, Danielly L A; Fragal, Vanessa H; Cellet, Thelma S P; Mauricio, Marcos R; Garcia, Francielle P; Nakamura, Celso V; Guilherme, Marcos R; Rubira, Adley F; Kunita, Marcos H

    2014-06-01

    Covalent TiO(2)-co-pectin microspheres containing Fe(3)O(4) nanoparticles were developed through an ultrasound-induced crosslinking/polymerization reaction between the glycidyl methacrylate from vinyl groups in TiO(2) and in pectin. ζ-potentials became less negative in the nanostructured microspheres, caused by the presence of both inorganic particles in the negatively charged pectin. The nanostructured pectin microspheres showed an amoxicillin release rate slower than that of pure pectin microspheres. The proposed microspheres were found to be a sustained release system of amoxicillin in the acid medium. Furthermore, the antibiotic release may be modulated by exposition of the microspheres to a remote magnetic field. In practical terms, the nanostructured microspheres could deliver a larger proportion of their initial load to specific site of action. The cytotoxic concentrations for 50% of VERO cells (CC(50)), calculated as the concentration required to reduce cell viability by 50% after 72h of incubation, for pectin-only microspheres and nanostructured pectin microspheres were 217.7±6.5 and 121.5±4.9μgmL(-1), respectively. The obtained CC(50) values indicated acceptable cytotoxic levels for an incubation period of 72h, showing that the pectin microspheres have a great pharmacological potential for uses in biological environments, even after the introduction of both Fe(3)O(4) and TiO(2). PMID:24565898

  7. Covalent TiO(2)/pectin microspheres with Fe(3)O(4) nanoparticles for magnetic field-modulated drug delivery.

    PubMed

    da Silva, Elisangela P; Sitta, Danielly L A; Fragal, Vanessa H; Cellet, Thelma S P; Mauricio, Marcos R; Garcia, Francielle P; Nakamura, Celso V; Guilherme, Marcos R; Rubira, Adley F; Kunita, Marcos H

    2014-06-01

    Covalent TiO(2)-co-pectin microspheres containing Fe(3)O(4) nanoparticles were developed through an ultrasound-induced crosslinking/polymerization reaction between the glycidyl methacrylate from vinyl groups in TiO(2) and in pectin. ζ-potentials became less negative in the nanostructured microspheres, caused by the presence of both inorganic particles in the negatively charged pectin. The nanostructured pectin microspheres showed an amoxicillin release rate slower than that of pure pectin microspheres. The proposed microspheres were found to be a sustained release system of amoxicillin in the acid medium. Furthermore, the antibiotic release may be modulated by exposition of the microspheres to a remote magnetic field. In practical terms, the nanostructured microspheres could deliver a larger proportion of their initial load to specific site of action. The cytotoxic concentrations for 50% of VERO cells (CC(50)), calculated as the concentration required to reduce cell viability by 50% after 72h of incubation, for pectin-only microspheres and nanostructured pectin microspheres were 217.7±6.5 and 121.5±4.9μgmL(-1), respectively. The obtained CC(50) values indicated acceptable cytotoxic levels for an incubation period of 72h, showing that the pectin microspheres have a great pharmacological potential for uses in biological environments, even after the introduction of both Fe(3)O(4) and TiO(2).

  8. Microvascular injury in persistent gastric ulcers after yttrium-90 microsphere radioembolization for liver malignancies.

    PubMed

    Sun, Belinda; Lapetino, Shawn R; Diffalha, Sameer A L; Yong, Sherri; Gaba, Ron C; Bui, James T; Koppe, Sean; Garzon, Steven; Guzman, Grace

    2016-04-01

    Yttrium-90 microsphere radioembolization ((90)Y MRE) is a therapy for liver malignancies by permanently implanting (90)Y-containing microspheres into tumors via hepatic artery. The etiology of persistent gastric ulcerations in patients presenting months after treatment remains unclear. Three patients who presented with gastric ulceration 4 to 13 months after (90)Y MRE were examined by esophagogastroduodenoscopy and biopsies. Pathological examinations showed multiple (90)Y microspheres scattered within the lamina propria and submucosa. Most of the microspheres were distributed in a linear fashion, consistent with an intravascular location; however, the vascular lumen and endothelial cells were not present. The microspheres were surrounded by fibrotic tissue infiltrated by chronic inflammatory cells and rare neutrophils. Epithelial granulation without pititis and miniaturized glands with intervening fibrosis were noted, compatible with chronic ischemic changes. These findings suggest that the persistent gastric ulceration is a result of localized ischemic injury in response to (90)Y MRE-induced vascular damage.

  9. Gastrointestinal system

    PubMed Central

    Cheng, Leo K.; O’Grady, Gregory; Du, Peng; Egbuji, John U.; Windsor, John A.; Pullan, Andrew J.

    2014-01-01

    The functions of the gastrointestinal (GI) tract include digestion, absorption, excretion, and protection. In this review, we focus on the electrical activity of the stomach and small intestine, which underlies the motility of these organs, and where the most detailed systems descriptions and computational models have been based to date. Much of this discussion is also applicable to the rest of the GI tract. This review covers four major spatial scales: cell, tissue, organ, and torso, and discusses the methods of investigation and the challenges associated with each. We begin by describing the origin of the electrical activity in the interstitial cells of Cajal, and its spread to smooth muscle cells. The spread of electrical activity through the stomach and small intestine is then described, followed by the resultant electrical and magnetic activity that may be recorded on the body surface. A number of common and highly symptomatic GI conditions involve abnormal electrical and/or motor activity, which are often termed functional disorders. In the last section of this review we address approaches being used to characterize and diagnose abnormalities in the electrical activity and how these might be applied in the clinical setting. The understanding of electrophysiology and motility of the GI system remains a challenging field, and the review discusses how biophysically based mathematical models can help to bridge gaps in our current knowledge, through integration of otherwise separate concepts. PMID:20836011

  10. Hierarchical Nanofibrous Microspheres with Controlled Growth Factor Delivery for Bone Regeneration.

    PubMed

    Ma, Chi; Jing, Yan; Sun, Hongchen; Liu, Xiaohua

    2015-12-01

    The integration of controlled growth factor delivery and biomimetic architecture into a microsphere is a challenging but attractive strategy for developing new injectable biomaterials. In this work, a unique hierarchical nanosphere-encapsulated-in-microsphere scaffolding system is developed. First, heparin-conjugated gelatin (HG) is synthesized, which provides binding domains for bone morphogenetic protein 2 (BMP2) to stabilize this growth factor, protect it from denaturation and proteolytic degradation, and subsequently prolong its sustained release. Next, a unique approach is developed which includes a water-in-oil-in-oil double emulsion process and a thermally induced phase separation to encapsulate BMP2-binding HG nanospheres into nanofibrous microspheres. The nanofibrous microsphere is self-assembled from synthetic nanofibers, and has superior surface area, high porosity, low density, and is an excellent carrier to support cell adhesion and tissue in-growth. BMP2 in the hierarchical microsphere is released in a multiple-controlled manner by the binding with heparin and encapsulation of the nanosphere and microsphere. An in vivo calvarial defect model confirms that this microsphere is an excellent osteoinductive scaffold for enhanced bone regeneration. By choosing different growth factors, this hierarchical microsphere system can easily be applied to other types of tissue regeneration. The work expands the ability to develop new injectable biomaterials for advanced regenerative therapies.

  11. Towards Monodispersed Polymer Microspheres

    NASA Astrophysics Data System (ADS)

    Senuma, Yoshinori; Hilborn, Jons

    1998-03-01

    Uniform polymer microspheres prepared by Spinning Disk Atomization Our spinning disk atomization (SDA) can, relative to other existing techniques, produce micron-sized particles of very narrow size distribution. Around the edge of the disk, small teeth channel the flow into identical droplets that are flung off over the disk rim. These solidify during flight to form spherical particles. Applications for spheres produced by SDA can be found in areas such as adhesives, powder coatings, food, biomedical use, drug delivery systems, etc. We have atomized polyethyleneglycol into very narrowly dispersed microspheres ranging from 50 to 500 =B5m. The aim of this work is to model the droplet formation occurring at the rim of the spinning disk in order to better understand the experimental results. The viscosity contribution in the fluid breakup is qualitatively analyzed and is adapted to the theoretical model to show how it affects the droplet size. We have used the pendant drop model (Ramesh Babu, S. Journal of Colloid and Interface Science 116, 350-372 (1987).) for spinning disk atomization to describe the drop-shape evolution during growth.

  12. Convective microsphere monolayer deposition

    NASA Astrophysics Data System (ADS)

    Gilchrist, James

    2011-03-01

    There is perhaps no simpler way of modifying surface chemistry and morphology than surface deposition of particles. Micron-sized microspheres were deposited into thin films via rapid convective deposition, similar to the `coffee ring effect' using a similar method to that studied by Prevo and Velev, Langmuir, 2003. By varying deposition rate and blade angle, the optimal operating ranges in which 2D close-packed arrays of microspheres existed were obtained. Self-assembly of colloidal particles through a balance of electrostatic and capillary forces during solvent evaporation was revealed. These interactions were explored through a model comparing the residence time of a particle in the thin film and the characteristic time of capillary-driven crystallization to describe the morphology and microstructure of deposited particles. Co-deposition of binary suspensions of micron and nanoscale particles was tailored to generate higher-quality surface coatings and a simple theory describes the immergence of instabilities that result in formation of stripes. Optical and biomedical applications that utilize the described nanoscale control over surface morphology will also be discussed.

  13. Microsphere based saliva diagnostics

    NASA Astrophysics Data System (ADS)

    Rissin, David M.; DiCesare, Christopher; Hayman, Ryan B.; Blicharz, Timothy M.; Walt, David R.

    2005-11-01

    Saliva presents a minimally invasive alternative medium to blood for performing diagnostics1. Microsphere sensors for ions, small organic molecules, and proteins are currently being developed and optical microarrays containing thousands of these sensors will be used for simultaneous multi-analyte analysis. The fiber bundle platform in use is 1mm in diameter and contains approximately 50,000 individually addressable 3.1μm fibers, each with an etched well capable of housing a single 3.1μm microsphere sensor. Micron-sized bead-based chemistries are produced in house, followed by deposition onto a fiber-optic bundle platform, allowing for multiplexed analysis. The ultimate goal is to develop a universal diagnostic system using saliva as the diagnostic medium. This platform will permit multiplexed analysis of a sample by integrating microfluidics with the optical arrays loaded with sensors capable of detecting relevant biomarkers associated with a wide range of disease states. Disease states that are currently under investigation include end stage renal disease (ESRD) and Sjoegrens Syndrome (SS).

  14. Electromigration of microspheres in ferroelectric smectic liquid crystals

    NASA Astrophysics Data System (ADS)

    Dierking, I.; Cass, P.; Syres, K.; Cresswell, R.; Morton, S.

    2007-08-01

    When an electric field is applied to microspheres which are dispersed in a ferroelectric smectic liquid crystal, particle translation along the smectic layer plane, i.e., in a direction nearly perpendicular to that of the director, can be observed. Under certain electric field conditions the translation is shown to be linear in time. We have determined the stability regime of linear particle displacement in the parameter space of amplitude and frequency for various applied wave forms. This regime enlarges for increasing electric field amplitude and frequency, with a threshold behavior observed for small parameters. The upper stability boundary is related to the reciprocal ferroelectric switching time. The microspheres translational velocity is independent of the applied electric field amplitude, but increases linearly with applied frequency. The microsphere velocity also increases with increasing temperature, which is indicative of the respective decrease in liquid crystal viscosity. Possible mechanisms of electric-field-induced particle motion are discussed.

  15. DJ-1 plays an important role in caffeic acid-mediated protection of the gastrointestinal mucosa against ketoprofen-induced oxidative damage.

    PubMed

    Cheng, Yu-Ting; Ho, Cheng-Ying; Jhang, Jhih-Jia; Lu, Chi-Cheng; Yen, Gow-Chin

    2014-10-01

    Ketoprofen is widely used to alleviate pain and inflammation in clinical medicine; however, this drug may cause oxidative stress and lead to gastrointestinal (GI) ulcers. We previously reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in protecting cells against reactive oxygen species, and it facilitates the prevention of ketoprofen-induced GI mucosal ulcers. Recent reports suggested that Nrf2 becomes unstable in the absence of DJ-1/PARK7, attenuating the activity of Nrf2-regulated downstream antioxidant enzymes. Thus, increasing Nrf2 translocation by DJ-1 may represent a novel means for GI protection. In vitro, caffeic acid increases the nuclear/cytosolic Nrf2 ratio and the mRNA expression of the downstream antioxidant enzymes, ϒ-glutamyl cysteine synthetase, glutathione peroxidase, glutathione reductase, and heme oxygenase-1, by activating the JNK/p38 pathway in Int-407 cells. Moreover, knockdown of DJ-1 also reversed caffeic acid-induced nuclear Nrf2 protein expression in a JNK/p38-dependent manner. Our results also indicated that treatment of Sprague-Dawley rats with caffeic acid prior to the administration of ketoprofen inhibited oxidative damage and reversed the inhibitory effects of ketoprofen on the antioxidant system and DJ-1 protein expression in the GI mucosa. Our observations suggest that DJ-1 plays an important role in caffeic acid-mediated protection against ketoprofen-induced oxidative damage in the GI mucosa.

  16. A facile one-pot sonochemical synthesis of surface-coated mannosyl protein microspheres for detection and killing of bacteria.

    PubMed

    Skirtenko, Natalia; Richman, Michal; Nitzan, Yeshayahu; Gedanken, Aharon; Rahimipour, Shai

    2011-12-01

    We report a remarkably facile one-pot sonochemical approach to prepare protein microspheres whose shells are covalently decorated with a mannosyl derivative to target Escherichia coli (E. coli), while their cores are encapsulated with tetracycline. Conjugated microspheres induced the agglutination of E. coli and increased the anti-bacterial activity of the encapsulated tetracycline by five fold.

  17. Glass microsphere lubrication

    NASA Technical Reports Server (NTRS)

    Geiger, Michelle; Goode, Henry; Ohanlon, Sean; Pieloch, Stuart; Sorrells, Cindy; Willette, Chris

    1991-01-01

    The harsh lunar environment eliminated the consideration of most lubricants used on earth. Considering that the majority of the surface of the moon consists of sand, the elements that make up this mixture were analyzed. According to previous space missions, a large portion of the moon's surface is made up of fine grained crystalline rock, about 0.02 to 0.05 mm in size. These fine grained particles can be divided into four groups: lunar rock fragments, glasses, agglutinates (rock particles, crystals, or glasses), and fragments of meteorite material (rare). Analysis of the soil obtained from the missions has given chemical compositions of its materials. It is about 53 to 63 percent oxygen, 16 to 22 percent silicon, 10 to 16 percent sulfur, 5 to 9 percent aluminum, and has lesser amounts of magnesium, carbon, and sodium. To be self-supporting, the lubricant must utilize one or more of the above elements. Considering that the element must be easy to extract and readily manipulated, silicon or glass was the most logical choice. Being a ceramic, glass has a high strength and excellent resistance to temperature. The glass would also not contaminate the environment as it comes directly from it. If sand entered a bearing lubricated with grease, the lubricant would eventually fail and the shaft would bind, causing damage to the system. In a bearing lubricated with a solid glass lubricant, sand would be ground up and have little effect on the system. The next issue was what shape to form the glass in. Solid glass spheres was the only logical choice. The strength of the glass and its endurance would be optimal in this form. To behave as an effective lubricant, the diameter of the spheres would have to be very small, on the order of hundreds of microns or less. This would allow smaller clearances between the bearing and the shaft, and less material would be needed. The production of glass microspheres was divided into two parts, production and sorting. Production includes the

  18. Effects of Dietary Honey andArdehCombination on Chemotherapy- Induced Gastrointestinal and Infectious Complications in Patients with Acute Myeloid Leukemia: A Double-Blind Randomized Clinical Trial.

    PubMed

    Ebrahimi, Mahmoud; Allahyari, Abolghasem; Ebrahimi, Mohsen; Hesam, Hesam; Hosseini, Golkoo; Karimi, Mohammad; Rezaiean, Amin; Kazemi, Mohammad Reza

    2016-01-01

    We aimed to investigate the effects of dietary combination of honey and Ardeh on chemotherapy-induced complications in patients with acute myeloid leukemia (AML). A total of 107 AML patients who underwent chemotherapy for at least 30 consecutive dayswere recruited to this double-blind randomized placebo-controlled clinical-trial which was conducted in the Imam Reza and Ghaem teaching hospitals (Mashhad, Iran). They weredivided into two age and sex-matched groups: 58 treated and 49 untreated patients. A combination of 50 grams of honey and 150 grams of Ardehwas added to the treated group's diet for 30consecutive days, three times each day; while the untreated group received their regular diet.Both groups received their standard medication for AML as well. After one month, they were all examined and lab tests were done on them by an internist and laboratory technicians who were blinded to the subject allocations. Mean value of WBC count in treated group was significantly lower than that of untreated group. Duration of fever and admission in the hospital due to fever were both significantly lower in the treated group (P=0.014, P=0.032 respectively). Total gastrointestinal complications were significantly less in the treated group one month after therapy with the special honey and Ardeh compound.No unusual or unexpected side effects were observed. Honey and Ardehare easily accessible materials that can be helpfully administered in AML patientsreceiving chemotherapy, since their useful effects in ameliorating gastrointestinal complications and reducingfever and neutropenia in AML patients have been shown. PMID:27642340

  19. Effects of Dietary Honey andArdehCombination on Chemotherapy- Induced Gastrointestinal and Infectious Complications in Patients with Acute Myeloid Leukemia: A Double-Blind Randomized Clinical Trial

    PubMed Central

    Ebrahimi, Mahmoud; Allahyari, Abolghasem; Ebrahimi, Mohsen; Hesam, Hesam; Hosseini, Golkoo; Karimi, Mohammad; Rezaiean, Amin; Kazemi, Mohammad Reza

    2016-01-01

    We aimed to investigate the effects of dietary combination of honey and Ardeh on chemotherapy-induced complications in patients with acute myeloid leukemia (AML). A total of 107 AML patients who underwent chemotherapy for at least 30 consecutive dayswere recruited to this double-blind randomized placebo-controlled clinical-trial which was conducted in the Imam Reza and Ghaem teaching hospitals (Mashhad, Iran). They weredivided into two age and sex-matched groups: 58 treated and 49 untreated patients. A combination of 50 grams of honey and 150 grams of Ardehwas added to the treated group’s diet for 30consecutive days, three times each day; while the untreated group received their regular diet.Both groups received their standard medication for AML as well. After one month, they were all examined and lab tests were done on them by an internist and laboratory technicians who were blinded to the subject allocations. Mean value of WBC count in treated group was significantly lower than that of untreated group. Duration of fever and admission in the hospital due to fever were both significantly lower in the treated group (P=0.014, P=0.032 respectively). Total gastrointestinal complications were significantly less in the treated group one month after therapy with the special honey and Ardeh compound.No unusual or unexpected side effects were observed. Honey and Ardehare easily accessible materials that can be helpfully administered in AML patientsreceiving chemotherapy, since their useful effects in ameliorating gastrointestinal complications and reducingfever and neutropenia in AML patients have been shown. PMID:27642340

  20. Enhanced dielectric polarization and electro-responsive characteristic of graphene oxide-wrapped titania microspheres

    NASA Astrophysics Data System (ADS)

    Yin, Jianbo; Shui, Yongjun; Dong, Yuezhen; Zhao, Xiaopeng

    2014-01-01

    Electric field-induced particle polarization is essential to the electro-responsive electrorheological (ER) effect of particle suspensions. In this work, we use graphene oxide (GO) as a soft and polar coating shell to prepare GO-wrapped titania dielectric microspheres for use as the dispersal phase of an ER suspension. Under a DC electric field, the ER characteristic of GO-wrapped titania microspheres dispersed in silicone oil is investigated by rheological tests, and then compared with that of a suspension of bare titania microspheres. The results show that the suspension of GO-wrapped titania microspheres possesses an enhanced ER characteristic. Its field-induced shear yield stress and storage modulus are much higher than those of the suspension of bare titania microspheres. The soft and polar GO shell is regarded as the origin of the ER enhancement. Dielectric analysis indicates that wrapping GO can enhance the interfacial polarization and thus improve the ER characteristics of titania microspheres. Wrapping GO onto the surface of titania microspheres can also reduce the particle sedimentation velocity of the suspension.

  1. Fabrication of glass microspheres with conducting surfaces

    DOEpatents

    Elsholz, William E.

    1984-01-01

    A method for making hollow glass microspheres with conducting surfaces by adding a conducting vapor to a region of the glass fabrication furnace. As droplets or particles of glass forming material pass through multiple zones of different temperature in a glass fabrication furnace, and are transformed into hollow glass microspheres, the microspheres pass through a region of conducting vapor, forming a conducting coating on the surface of the microspheres.

  2. Fabrication of glass microspheres with conducting surfaces

    DOEpatents

    Elsholz, W.E.

    1982-09-30

    A method for making hollow glass microspheres with conducting surfaces by adding a conducting vapor to a region of the glass fabrication furnace. As droplets or particles of glass forming material pass through multiple zones of different temperature in a glass fabrication furnace, and are transformed into hollow glass microspheres, the microspheres pass through a region of conducting vapor, forming a conducting coating on the surface of the microspheres.

  3. Osteoporosis in Gastrointestinal Diseases.

    PubMed

    Krela-Kaźmierczak, Iwona; Szymczak, Aleksandra; Łykowska-Szuber, Liliana; Eder, Piotr; Linke, Krzysztof

    2016-01-01

    Secondary osteoporosis occurs as an isolated pathology or co-exists with types I and II osteoporosis. The gastroenterologist may come across osteoporosis or osteopenia in a patient with a gastrointestinal disease. This is often a young patient in whom investigations should be carried out and appropriate treatment initiated, aimed at preventing bone fractures and the formation of the best peak bone mass. Osteoporosis occurs in patients with the following conditions: Crohn's disease, ulcerative colitis, celiac disease, post gastrectomy patients, patients with short bowel syndrome, chronic hepatitis and cirrhosis, treated with steroids (steroid-induced osteoporosis) and patients using proton pump inhibitors chronically (state of achlorhydria). It is therefore necessary to approve a list of risk factors of secondary osteoporosis, the presence of which would be an indication for screening for osteoporosis, including a DXA study and the development of a separate algorithm for the therapeutic management of secondary osteoporosis accompanying gastrointestinal diseases, especially in premenopausal young women and young men, because there are currently no registered drugs with proven antifracture activity for this group of patients. PMID:26935513

  4. Inflammation-induced drug release by using a pH-responsive gas-generating hollow-microsphere system for the treatment of osteomyelitis.

    PubMed

    Chung, Ming-Fan; Chia, Wei-Tso; Liu, Hung-Yi; Hsiao, Chun-Wen; Hsiao, Hsu-Chan; Yang, Chih-Man; Sung, Hsing-Wen

    2014-11-01

    In the conventional treatment of osteomyelitis, the penetration of antibiotics into the infected bone is commonly poor. To ensure that the local antibiotic concentration is adequate, this work develops an injectable calcium phosphate (CP) cement in which is embedded pH-responsive hollow microspheres (HMs) that can control the release of a drug according to the local pH. The HMs are fabricated using a microfluidic device, with a shell of poly(D,L-lactic-co-glycolic acid) (PLGA) and an aqueous core that contains vancomycin (Van) and NaHCO3. At neutral pH, the CP/HM cement elutes a negligible concentration of the drug. In an acidic environment, the NaHCO3 that is encapsulated in the HMs reacts with the acid rapidly to generate CO2 bubbles, disrupting the PLGA shells and thereby releasing Van locally in excess of a therapeutic threshold. The feasibility of using this CP/HM cement to treat osteomyelitis is studied using a rabbit model. Analytical results reveal that the CP/HM cement provides highly effective local antibacterial activity. Histological examination further verifies the efficacy of the treatment by the CP/HM cement. The above findings suggest that the CP/HM cement is a highly efficient system for the local delivery of antibiotics in the treatment of osteomyelitis.

  5. Interaction Induced High Catalytic Activities of CoO Nanoparticles Grown on Nitrogen-Doped Hollow Graphene Microspheres for Oxygen Reduction and Evolution Reactions

    NASA Astrophysics Data System (ADS)

    Jiang, Zhong-Jie; Jiang, Zhongqing

    2016-06-01

    Nitrogen doped graphene hollow microspheres (NGHSs) have been used as the supports for the growth of the CoO nanoparticles. The nitrogen doped structure favors the nucleation and growth of the CoO nanoparticles and the CoO nanoparticles are mostly anchored on the quaternary nitrogen doped sites of the NGHSs with good monodispersity since the higher electron density of the quaternary nitrogen favors the nucleation and growth of the CoO nanoparticles through its coordination and electrostatic interactions with the Co2+ ions. The resulting NGHSs supported CoO nanoparticles (CoO/NGHSs) are highly active for the oxygen reduction reaction (ORR) with activity and stability higher than the Pt/C and for the oxygen evolution reaction (OER) with activity and stability comparable to the most efficient catalysts reported to date. This indicates that the CoO/NGHSs could be used as efficient bi-functional catalysts for ORR and OER. Systematic analysis shows that the superior catalytic activities of the CoO/NGHSs for ORR and OER mainly originate from the nitrogen doped structure of the NGHSs, the small size of the CoO nanoparticles, the higher specific and electroactive surface area of the CoO/NGHSs, the good electric conductivity of the CoO/NGHSs, the strong interaction between the CoO nanoparticles and the NGHSs, etc.

  6. Interaction Induced High Catalytic Activities of CoO Nanoparticles Grown on Nitrogen-Doped Hollow Graphene Microspheres for Oxygen Reduction and Evolution Reactions

    PubMed Central

    Jiang, Zhong-Jie; Jiang, Zhongqing

    2016-01-01

    Nitrogen doped graphene hollow microspheres (NGHSs) have been used as the supports for the growth of the CoO nanoparticles. The nitrogen doped structure favors the nucleation and growth of the CoO nanoparticles and the CoO nanoparticles are mostly anchored on the quaternary nitrogen doped sites of the NGHSs with good monodispersity since the higher electron density of the quaternary nitrogen favors the nucleation and growth of the CoO nanoparticles through its coordination and electrostatic interactions with the Co2+ ions. The resulting NGHSs supported CoO nanoparticles (CoO/NGHSs) are highly active for the oxygen reduction reaction (ORR) with activity and stability higher than the Pt/C and for the oxygen evolution reaction (OER) with activity and stability comparable to the most efficient catalysts reported to date. This indicates that the CoO/NGHSs could be used as efficient bi-functional catalysts for ORR and OER. Systematic analysis shows that the superior catalytic activities of the CoO/NGHSs for ORR and OER mainly originate from the nitrogen doped structure of the NGHSs, the small size of the CoO nanoparticles, the higher specific and electroactive surface area of the CoO/NGHSs, the good electric conductivity of the CoO/NGHSs, the strong interaction between the CoO nanoparticles and the NGHSs, etc. PMID:27255562

  7. Inflammation-induced drug release by using a pH-responsive gas-generating hollow-microsphere system for the treatment of osteomyelitis.

    PubMed

    Chung, Ming-Fan; Chia, Wei-Tso; Liu, Hung-Yi; Hsiao, Chun-Wen; Hsiao, Hsu-Chan; Yang, Chih-Man; Sung, Hsing-Wen

    2014-11-01

    In the conventional treatment of osteomyelitis, the penetration of antibiotics into the infected bone is commonly poor. To ensure that the local antibiotic concentration is adequate, this work develops an injectable calcium phosphate (CP) cement in which is embedded pH-responsive hollow microspheres (HMs) that can control the release of a drug according to the local pH. The HMs are fabricated using a microfluidic device, with a shell of poly(D,L-lactic-co-glycolic acid) (PLGA) and an aqueous core that contains vancomycin (Van) and NaHCO3. At neutral pH, the CP/HM cement elutes a negligible concentration of the drug. In an acidic environment, the NaHCO3 that is encapsulated in the HMs reacts with the acid rapidly to generate CO2 bubbles, disrupting the PLGA shells and thereby releasing Van locally in excess of a therapeutic threshold. The feasibility of using this CP/HM cement to treat osteomyelitis is studied using a rabbit model. Analytical results reveal that the CP/HM cement provides highly effective local antibacterial activity. Histological examination further verifies the efficacy of the treatment by the CP/HM cement. The above findings suggest that the CP/HM cement is a highly efficient system for the local delivery of antibiotics in the treatment of osteomyelitis. PMID:24789379

  8. A Diet Containing Beta-Hydroxy-Beta-Methylbutyrate, L-Glutamine and L-Arginine Ameliorates Chemoradiation-Induced Gastrointestinal Injury in Rats.

    PubMed

    Alsan Cetin, Ilknur; Atasoy, Beste M; Cilaker, Serap; Alicikus, Lutfiye Zumre Arican; Karaman, Meral; Ersoy, Nevin; Demiral, Ayse Nur; Yilmaz, Osman

    2015-10-01

    The aim of this study was to investigate the effects of a specific diet, containing beta-hydroxy-beta-methylbutyrate, L-glutamine and L-arginine (HMB/Glu/Arg), on chemoradiation-induced injuries of the rat gastrointestinal mucosa. Wistar albino rats were divided into 4 groups: control (n = 5); radiation (n = 14); 5-fluorouracil treatment (5-FU; n = 14); and radiation and 5-FU treatment (n = 14). Rats were fed either a standard diet or a specific diet (SpD) containing HMB/Glu/Arg supplementation for 7 days prior to radiation exposure and/or 5-FU treatment. The irradiated groups were exposed to an 1 Gy dose of 6 MV x rays delivered to the who-abdominal. The animals receiving 5-FU treatment were given a 100 mg/kg dose of the drug. In the radiation and 5-FU treatment group, the 5-FU was administered 30 min prior to irradiation. After irradiation and/or 5-FU treatment, feeding with either the standard rat diet or specific diet continued as before. All animals were sacrificed on day 4 after irradiation and 5-FU treatment. Data collected included microbiological, histological and immunohistochemical end points. We found that bacterial colony counts in the ceca and mesenteric lymph nodes of irradiated rats treated with 5-FU were significantly lower in the specific diet (SpD) group than in the standard diet group (P = 0.002-0.05). Morphometrically, gastric, duodenal and colonic mucosal injuries were less severe in the irradiated animals fed the specific diet, as well as the 5-FU-treated animals fed the specific diet, compared to the similarly treated standard diet groups. Apoptosis, measured by TUNEL, revealed significantly lower numbers of TUNEL positive cells in irradiated animals fed the specific diet, and irradiated animals treated with 5-FU and fed the specific diet compared to irradiated animals fed the standard diet, and irradiated animals treated with 5-FU and fed the standard diet. In the 5-Fu-treated and SpD group, the extent of apoptosis was significantly lower

  9. New strategy of tacrolimus administration in animal model based on tacrolimus-loaded microspheres.

    PubMed

    Zamorano-Leon, Jose J; Hernandez-Fisac, Ines; Guerrero, Sandra; Tamarit-Rodriguez, Jorge; Santos-Sancho, Juana M; Sopeña, Bernardo; Escolar, Ginés; López-Vilchez, Irene; Duarte, Juan; Barrientos, Alberto; López-Farré, Antonio J

    2016-05-01

    New strategies for tacrolimus administration that conserve its immunosuppressive effect but avoiding fluctuations in tacrolimus circulating levels are needed. The aim was to analyze if subcutaneous biodegradable tacrolimus-loaded microspheres injection promoted a significant immunosuppressive response in rats. Rats received two subcutaneous tacrolimus-loaded microspheres injections at different days, the first injection was done at day 0 and the second injection was done 12 days after. Plasma circulating levels of tacrolimus, interleukin-2 (IL-2) and calcineurin phosphatase (PP2B) activity in mononuclear cells were measured. Tacrolimus plasma levels were significantly increased from the day after tacrolimus-loaded microspheres injection and remained increased during 10days. Compared to control, plasma IL-2 levels and PP2B activity in mononuclear cells were significantly decreased during ten days. At day 12, a new subcutaneous injection of tacrolimus-loaded microspheres was performed and two days after injection, tacrolimus plasma levels were again increased and both IL-2 plasma levels and PP2B activity decreased. A single subcutaneous tacrolimus-loaded microspheres injection was enough to reduce tacrolimus-related immunosuppressive parameters. These results open the possibility of new therapeutic strategies to administrate calcineurin inhibitors reducing the variability of their circulating levels related to gastrointestinal drug absorption/metabolism modifications.

  10. Zinc and gastrointestinal disease

    PubMed Central

    Skrovanek, Sonja; DiGuilio, Katherine; Bailey, Robert; Huntington, William; Urbas, Ryan; Mayilvaganan, Barani; Mercogliano, Giancarlo; Mullin, James M

    2014-01-01

    This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases. PMID:25400994

  11. Triggered drug release from dynamic microspheres via a protein conformational change.

    PubMed

    King, William J; Pytel, Nicholas J; Ng, Kelvin; Murphy, William L

    2010-06-11

    In this study we formed and characterized dynamic hydrogel microspheres in which a protein conformational change was used to control microsphere volume changes and the release of an encapsulated drug. In particular, a specific biochemical ligand, trifluoperazine, induced calmodulin's nanometer scale conformation change, which translated to a 48.7% microsphere volume decrease. This specific, ligand-induced volume change triggered the release of a model drug, vascular endothelial growth factor (VEGF), at pre-determined times. After release from the microspheres, 85.6 +/- 10.5% of VEGF was in its native conformation. Taken together, these results suggest that protein conformational change could serve as a useful mechanism to control drug release from dynamic hydrogels.

  12. Microspheres and their methods of preparation

    DOEpatents

    Bose, Anima B; Yang, Junbing

    2015-03-24

    Carbon microspheres are doped with boron to enhance the electrical and physical properties of the microspheres. The boron-doped carbon microspheres are formed by a CVD process in which a catalyst, carbon source and boron source are evaporated, heated and deposited onto an inert substrate.

  13. Multilayered polymer microspheres by thermal imprinting during microsphere growth.

    PubMed

    Takekoh, Ryu; Li, Wen-Hui; Burke, Nicholas A D; Stöver, Harald D H

    2006-01-11

    Modulation of the polymerization temperature in precipitation polymerizations was used to form onion-type polymer microspheres consisting of multiple nested layers. Specifically, the copolymerization of chloromethylstyrene and divinylbenzene-55 in acetonitrile, at temperatures ramping between 65 and 75 degrees C, led to monodisperse, cross-linked microspheres of about 10 mum diameter that have radial density profiles closely reflecting the thermal profiles used. This thermal imprinting is attributed to the copolymer formed being close to its theta point during the polymerization. As the microspheres grow by continuously capturing oligomers from solution, the resulting transient surface gel layer expands and contracts with temperature, and thus records the reaction temperature profile in the form of a corresponding density profile, even as it cross-links.

  14. Multilayered polymer microspheres by thermal imprinting during microsphere growth.

    PubMed

    Takekoh, Ryu; Li, Wen-Hui; Burke, Nicholas A D; Stöver, Harald D H

    2006-01-11

    Modulation of the polymerization temperature in precipitation polymerizations was used to form onion-type polymer microspheres consisting of multiple nested layers. Specifically, the copolymerization of chloromethylstyrene and divinylbenzene-55 in acetonitrile, at temperatures ramping between 65 and 75 degrees C, led to monodisperse, cross-linked microspheres of about 10 mum diameter that have radial density profiles closely reflecting the thermal profiles used. This thermal imprinting is attributed to the copolymer formed being close to its theta point during the polymerization. As the microspheres grow by continuously capturing oligomers from solution, the resulting transient surface gel layer expands and contracts with temperature, and thus records the reaction temperature profile in the form of a corresponding density profile, even as it cross-links. PMID:16390152

  15. Optical trapping of coated microspheres.

    PubMed

    Bormuth, Volker; Jannasch, Anita; Ander, Marcel; van Kats, Carlos M; van Blaaderen, Alfons; Howard, Jonathon; Schäffer, Erik

    2008-09-01

    In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm--the trapping laser wavelength in water--and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays.

  16. Advances in Microsphere Insulation Systems

    NASA Astrophysics Data System (ADS)

    Allen, M. S.; Baumgartner, R. G.; Fesmire, J. E.; Augustynowicz, S. D.

    2004-06-01

    Microsphere insulation, typically consisting of hollow glass bubbles, combines in a single material the desirable properties that other insulations only have individually. The material has high crush strength, low density, is noncombustible, and performs well in soft vacuum. Microspheres provide robust, low-maintenance insulation systems for cryogenic transfer lines and dewars. They also do not suffer from compaction problems typical of perlite that result in the necessity to reinsulate dewars because of degraded thermal performance and potential damage to its support system. Since microspheres are load bearing, autonomous insulation panels enveloped with lightweight vacuum-barrier materials can be created. Comprehensive testing performed at the Cryogenics Test Laboratory located at the NASA Kennedy Space Center demonstrated competitive thermal performance with other bulk materials. Test conditions were representative of actual-use conditions and included cold vacuum pressure ranging from high vacuum to no vacuum and compression loads from 0 to 20 psi. While microspheres have been recognized as a legitimate insulation material for decades, actual implementation has not been pursued. Innovative microsphere insulation system configurations and applications are evaluated.

  17. Mesenchymal stem cell-encapsulated collagen microspheres for bone tissue engineering.

    PubMed

    Chan, Barbara Pui; Hui, Ting Yan; Wong, Mei Yi; Yip, Kevin Hak Kong; Chan, Godfrey Chi Fung

    2010-04-01

    There is a demonstrated clinical need for alternatives of autologous fresh bone graft with excellent biological performance in osteoconductivity, osteoinductivity, and osteogenicity. We previously developed a collagen microencapsulation technology entrapping bone marrow-derived mesenchymal stem cells (MSCs) in a biomimetic collagen fiber meshwork and produced injectable collagen-MSC microspheres. In this study, we hypothesize that injectable microspheres with osteoconductivity, osteogenicity, and osteoinductivity can be fabricated by differentiating the encapsulated MSCs, from either human or mouse sources, toward osteogenic lineages in these three-dimensional microspheres. The osteogenicity, osteoconductivity, and osteoinductivity of the microspheres were evaluated in vitro. Osteogenic markers of the differentiating MSCs including alkaline phosphatase and calcium deposition showed positive staining. Osteoconductivity of the collagen meshwork in the microsphere was demonstrated by the presence of calcium phosphate deposits among the collagen fibers and by the significantly increased calcium content extracted from the microspheres. Moreover, osteoinductivity of the MSC-encapsulated microspheres was demonstrated by the ability to induce osteogenic differentiation of undifferentiated MSCs in both contact and noncontact coculture. This study contributes toward the future development of injectable alternatives for fresh bone grafts using autologous MSCs.

  18. Preparation, evaluation and bioavailability studies of indomethacin-bees wax microspheres.

    PubMed

    Gowda, D V; Ravi, Valluru; Shivakumar, H G; Hatna, Siddaramaiah

    2009-07-01

    The present study envisages the preparation of microspheres containing indomethacin (IM) as model drug and bees wax as carrier, and to compare the in vitro release and pharmacokinetics of prepared IM formulation with commercially available oral formulation MicrocidSR. The microsphere formulations were prepared by meltable emulsified dispersion and cooling induced solidification. Surface morphology of microspheres has been evaluated using scanning electron microscopy (SEM). The SEM images revealed the spherical shape of microspheres and more than 98.0% of the isolated microspheres were in the size range 115-855 mum. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy studies indicated that the drug after encapsulation with bees wax was stable and compatible. A single dose randomized complete cross over study of IM (75 mg) microspheres was carried out on 8 healthy Albino sheeps. Plasma IM concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The T (max), C (max), AUC(O-24) and T (1/2) values of MicrocidSR and optimized formulation were 3.0 h, 2038 +/- 51.31 ng/ml, 9528 +/- 129.65 ng/ml h(-1), and 2.59 +/- 0.02 h(-1); and 3.2 h, 1940 +/- 22.61 ng/ml, 8751 +/- 41.32 ng/ml h(-1), and 2.68 +/- 0.02 h(-1), respectively. Beeswax microspheres showed controlled release and it can be concluded that both the prepared formulation and MicrocidSR are bioequivalent.

  19. Angiogenic microspheres promote neural regeneration and motor function recovery after spinal cord injury in rats

    PubMed Central

    Yu, Shukui; Yao, Shenglian; Wen, Yujun; Wang, Ying; Wang, Hao; Xu, Qunyuan

    2016-01-01

    This study examined sustained co-delivery of vascular endothelial growth factor (VEGF), angiopoietin-1 and basic fibroblast growth factor (bFGF) encapsulated in angiogenic microspheres. These spheres were delivered to sites of spinal cord contusion injury in rats, and their ability to induce vessel formation, neural regeneration and improve hindlimb motor function was assessed. At 2–8 weeks after spinal cord injury, ELISA-determined levels of VEGF, angiopoietin-1, and bFGF were significantly higher in spinal cord tissues in rats that received angiogenic microspheres than in those that received empty microspheres. Sites of injury in animals that received angiogenic microspheres also contained greater numbers of isolectin B4-binding vessels and cells positive for nestin or β III-tubulin (P < 0.01), significantly more NF-positive and serotonergic fibers, and more MBP-positive mature oligodendrocytes. Animals receiving angiogenic microspheres also suffered significantly less loss of white matter volume. At 10 weeks after injury, open field tests showed that animals that received angiogenic microspheres scored significantly higher on the Basso-Beattie-Bresnahan scale than control animals (P < 0.01). Our results suggest that biodegradable, biocompatible PLGA microspheres can release angiogenic factors in a sustained fashion into sites of spinal cord injury and markedly stimulate angiogenesis and neurogenesis, accelerating recovery of neurologic function. PMID:27641997

  20. Angiogenic microspheres promote neural regeneration and motor function recovery after spinal cord injury in rats.

    PubMed

    Yu, Shukui; Yao, Shenglian; Wen, Yujun; Wang, Ying; Wang, Hao; Xu, Qunyuan

    2016-01-01

    This study examined sustained co-delivery of vascular endothelial growth factor (VEGF), angiopoietin-1 and basic fibroblast growth factor (bFGF) encapsulated in angiogenic microspheres. These spheres were delivered to sites of spinal cord contusion injury in rats, and their ability to induce vessel formation, neural regeneration and improve hindlimb motor function was assessed. At 2-8 weeks after spinal cord injury, ELISA-determined levels of VEGF, angiopoietin-1, and bFGF were significantly higher in spinal cord tissues in rats that received angiogenic microspheres than in those that received empty microspheres. Sites of injury in animals that received angiogenic microspheres also contained greater numbers of isolectin B4-binding vessels and cells positive for nestin or β III-tubulin (P < 0.01), significantly more NF-positive and serotonergic fibers, and more MBP-positive mature oligodendrocytes. Animals receiving angiogenic microspheres also suffered significantly less loss of white matter volume. At 10 weeks after injury, open field tests showed that animals that received angiogenic microspheres scored significantly higher on the Basso-Beattie-Bresnahan scale than control animals (P < 0.01). Our results suggest that biodegradable, biocompatible PLGA microspheres can release angiogenic factors in a sustained fashion into sites of spinal cord injury and markedly stimulate angiogenesis and neurogenesis, accelerating recovery of neurologic function. PMID:27641997

  1. Polarization Dependent Whispering Gallery Modes in Microspheres

    NASA Technical Reports Server (NTRS)

    Adamovsky, Grigory (Inventor); Wrbanek, Susan Y. (Inventor)

    2016-01-01

    A tunable resonant system is provided and includes a microsphere that receives an incident portion of a light beam generated via a light source, the light beam having a fundamental mode, a waveguide medium that transmits the light beam from the light source to the microsphere, and a polarizer disposed in a path of the waveguide between the light source and the microsphere. The incident portion of the light beam creates a fundamental resonance inside the microsphere. A change in a normalized frequency of the wavelength creates a secondary mode in the waveguide and the secondary mode creates a secondary resonance inside the microsphere.

  2. Agonists of the TRAIL Death Receptor DR5 Sensitize Intestinal Stem Cells to Chemotherapy-Induced Cell Death and Trigger Gastrointestinal Toxicity.

    PubMed

    Finnberg, Niklas K; Gokare, Prashanth; Navaraj, Arunasalam; Lang Kuhs, Krystle A; Cerniglia, George; Yagita, Hideo; Takeda, Kazuyoshi; Motoyama, Noboru; El-Deiry, Wafik S

    2016-02-01

    The combination of TRAIL death receptor agonists and radiochemotherapy to treat advanced cancers continues to be investigated in clinical trials. We previously showed that normal cells with a functional DNA damage response (DDR) upregulate the expression of death-inducing receptor DR5/TRAILR2/TNFRSF10B in a p53-dependent manner that sensitizes them to treatment with DR5 agonists. However, it is unclear if targeting DR5 selectively sensitizes cancer cells to agonist treatment following exposure to DNA-damaging chemotherapy, and to what extent normal tissues are targeted. Here, we show that the combined administration of the DR5 agonistic monoclonal antibody (mAb) and chemotherapy to wild-type mice triggered synergistic gastrointestinal toxicities (GIT) that were associated with the death of Lgr5(+) crypt base columnar stem cells in a p53- and DR5-dependent manner. Furthermore, we confirmed that normal human epithelial cells treated with the human DR5-agonistic mAb and chemotherapeutic agents were also greatly sensitized to cell death. Interestingly, our data also indicated that genetic or pharmacologic targeting of Chk2 may counteract GIT without negatively affecting the antitumor responses of combined DR5 agonist/chemotherapy treatment, further linking the DDR to TRAIL death receptor signaling in normal cells. In conclusion, the combination of DR5-targeting agonistic mAbs with DNA damaging chemotherapy may pose a risk of developing toxicity-induced conditions, and the effects of mAb-based strategies on the dose-limiting toxicity of chemotherapy must be considered when establishing new combination therapies.

  3. Production of monodisperse, polymeric microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Rhim, Won-Kyu (Inventor); Hyson, Michael T. (Inventor); Chang, Manchium (Inventor)

    1990-01-01

    Very small, individual polymeric microspheres with very precise size and a wide variation in monomer type and properties are produced by deploying a precisely formed liquid monomer droplet, suitably an acrylic compound such as hydroxyethyl methacrylate into a containerless environment. The droplet which assumes a spheroid shape is subjected to polymerizing radiation such as ultraviolet or gamma radiation as it travels through the environment. Polymeric microspheres having precise diameters varying no more than plus or minus 5 percent from an average size are recovered. Many types of fillers including magnetic fillers may be dispersed in the liquid droplet.

  4. Highly Sensitive and Reproducible SERS Performance from Uniform Film Assembled by Magnetic Noble Metal Composite Microspheres.

    PubMed

    Niu, Chunyu; Zou, Bingfang; Wang, Yongqiang; Cheng, Lin; Zheng, Haihong; Zhou, Shaomin

    2016-01-26

    To realize highly sensitive and reproducible SERS performance, a new route was put forward to construct uniform SERS film by using magnetic composite microspheres. In the experiment, monodisperse Fe3O4@SiO2@Ag microspheres with hierarchical surface were developed and used as building block of SERS substrate, which not only realized fast capturing analyte through dispersion and collection under external magnet but also could be built into uniform film through magnetically induced self-assembly. By using R6G as probe molecule, the as-obtained uniform film exhibited great improvement on SERS performance in both sensitivity and reproducibility when compared with nonuniform film, demonstrating the perfect integration of high sensitivity of hierarchal noble metal microspheres and high reproducibility of ordered microspheres array. Furthermore, the as-obtained product was used to detect pesticide thiram and also exhibited excellent SERS performance for trace detection.

  5. Porosity-Tuned Chitosan-Polyacrylamide Hydrogel Microspheres for Improved Protein Conjugation.

    PubMed

    Jung, Sukwon; Abel, John H; Starger, Jesse L; Yi, Hyunmin

    2016-07-11

    We report a robust method to manufacture polyacrylamide-based functional hydrogel microspheres with readily tunable macroporous structures by utilizing a simple micromolding-based technique. Specifically, surface tension-induced droplet formation of aqueous solutions of chitosan and acrylamide in 2D-shaped micromolds followed by photoinduced polymerization leads to monodisperse microspheres. Pore sizes of the microspheres can be readily tuned by simple addition of inert long-chain poly(ethylene glycol) porogen at low content in the prepolymer solution. The as-prepared chitosan-polyacrylamide microspheres exhibit chemical functionality through chitosan's primary amines, rapid protein conjugation with selective tetrazine-trans-cyclooctene reaction, and nonfouling property. Combined with the potential to create anisotropic network structures, we envision that our simple fabrication-conjugation method would offer a potent route to manufacture a variety of biofunctionalized hydrogel microentities.

  6. Mesoporous Au/TiO2 nanocomposite microspheres for visible-light photocatalysis.

    PubMed

    Wang, Guannan; Wang, Xiaofei; Liu, Junfeng; Sun, Xiaoming

    2012-04-23

    Mesoporous Au/TiO(2) nanocomposite microspheres have been synthesized by using a microemulsion-based bottom-up self-assembly (EBS) process starting from monodisperse gold and titania nanocrystals as building blocks. The microspheres had large surface areas (above 270 m(2) g(-1)) and open mesopores (about 5 nm), which led to the adsorption-driven concentration of organic molecules in the vicinity of the microspheres. Au nanoparticles, which were stably confined within the microspheres, enhanced the absorption over the broad UV/Vis/NIR spectroscopic range, owing to their strong surface plasmon resonance (SPR); as a result, the Au nanoparticles promoted the visible-light photo-induced degradation of organic compounds.

  7. Thrombin receptor agonist Peptide immobilized in microspheres stimulates reparative processes in rats with gastric ulcer.

    PubMed

    Rusanova, A V; Makarova, A M; Strukova, S M; Markvicheva, E A; Gorbachyova, L R; Stashevskaya, K S; Vasil'eva, T V; Sidorova, E I; Bespalova, Zh D; Grandfils, Ch

    2006-07-01

    The effect of synthetic thrombin receptor (PAR1) agonist peptide encapsulated in microspheres made of lactic and glycolic acid copolymer on tissue reparation was studied in rats with acetate-induced ulcer. PAR1 agonist peptide was immobilized in biodegraded lactic and glycolic acid microspheres by double emulgation, the kinetics of peptide release was analyzed, and the dynamics of ulcer healing was studied in experimental (administration of microspheres with the peptide into the stomach) and two control groups (administration of saline or spheres without peptide). Thrombin receptor agonist peptide gradually released from lactic and glycolic acid microspheres into the stomach shortened the inflammation phase and shifted the proliferation phase to the earlier period, thus accelerating healing of experimental ulcers in rats. PMID:17369897

  8. Porosity-Tuned Chitosan-Polyacrylamide Hydrogel Microspheres for Improved Protein Conjugation.

    PubMed

    Jung, Sukwon; Abel, John H; Starger, Jesse L; Yi, Hyunmin

    2016-07-11

    We report a robust method to manufacture polyacrylamide-based functional hydrogel microspheres with readily tunable macroporous structures by utilizing a simple micromolding-based technique. Specifically, surface tension-induced droplet formation of aqueous solutions of chitosan and acrylamide in 2D-shaped micromolds followed by photoinduced polymerization leads to monodisperse microspheres. Pore sizes of the microspheres can be readily tuned by simple addition of inert long-chain poly(ethylene glycol) porogen at low content in the prepolymer solution. The as-prepared chitosan-polyacrylamide microspheres exhibit chemical functionality through chitosan's primary amines, rapid protein conjugation with selective tetrazine-trans-cyclooctene reaction, and nonfouling property. Combined with the potential to create anisotropic network structures, we envision that our simple fabrication-conjugation method would offer a potent route to manufacture a variety of biofunctionalized hydrogel microentities. PMID:27351270

  9. Conferring Natural-Derived Porous Microspheres with Surface Multifunctionality through Facile Coordination-Enabled Self-Assembly Process.

    PubMed

    Han, Pingping; Shi, Jiafu; Nie, Teng; Zhang, Shaohua; Wang, Xueyan; Yang, Pengfei; Wu, Hong; Jiang, Zhongyi

    2016-03-01

    In this study, multifunctional chitin microspheres are synthesized and utilized as a platform for multiple potential applications in enzyme immobilization, catalytic reduction and adsorption. Porous chitin microspheres with an average diameter of 111.5 μm and a porous architecture are fabricated through a thermally induced phase separation method. Then, the porous chitin microspheres are conferred with surface multifunctionality through facile coordination-enabled self-assembly of tannic acid (TA) and titanium (Ti(IV)) bis(ammonium lactate)dihydroxide (Ti-BALDH). The multipoint hydrogen bonds between TA and chitin microspheres confer the TA-Ti(IV) coating with high adhesion capability to adhere firmly to the surface of the chitin microspheres. In view of the biocompatibility, porosity and surface activity, the multifunctional chitin microspheres are used as carriers for enzyme immobilization. The enzyme-conjugated multifunctional porous microspheres exhibit high catalytic performance (102.8 U·mg(-1) yeast alcohol dehydrogenase). Besides, the multifunctional chitin microspheres also find potential applications in the catalytic reduction (e.g., reduction of silver ions to silver nanoparticles) and efficient adsorption of heavy metal ions (e.g., Pb(2+)) taking advantages of their porosity, reducing capability and chelation property.

  10. Gastrointestinal Morbidity in Obesity

    PubMed Central

    Acosta, Andres; Camilleri, Michael

    2014-01-01

    Obesity is a complex disease that results from increased energy intake and decreased energy expenditure. The gastrointestinal system plays a key role in the pathogenesis of obesity and facilitates caloric imbalance. Changes in gastrointestinal hormones and the inhibition of mechanisms that curtail caloric intake result in weight gain. It is not clear if the gastrointestinal role in obesity is a cause or an effect of this disease. Obesity is often associated with type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). Obesity is also associated with gastrointestinal disorders, which are more frequent and present earlier than T2DM and CVD. Diseases such as gastro-esophageal reflux disease, cholelithiasis or non-alcoholic steatohepatitis are directly related to body weight and abdominal adiposity. Our objective is to assess the role of each gastrointestinal organ in obesity and the gastrointestinal morbidity resulting in those organs from effects of obesity. PMID:24602085

  11. Development of Risperidone PLGA Microspheres

    PubMed Central

    D'Souza, Susan; Faraj, Jabar A.; Giovagnoli, Stefano; DeLuca, Patrick P.

    2014-01-01

    The aim of this study was to design and evaluate biodegradable PLGA microspheres for sustained delivery of Risperidone, with an eventual goal of avoiding combination therapy for the treatment of schizophrenia. Two PLGA copolymers (50 : 50 and 75 : 25) were used to prepare four microsphere formulations of Risperidone. The microspheres were characterized by several in vitro techniques. In vivo studies in male Sprague-Dawley rats at 20 and 40 mg/kg doses revealed that all formulations exhibited an initial burst followed by sustained release of the active moiety. Additionally, formulations prepared with 50 : 50 PLGA had a shorter duration of action and lower cumulative AUC levels than the 75 : 25 PLGA microspheres. A simulation of multiple dosing at weekly or 15-day regimen revealed pulsatile behavior for all formulations with steady state being achieved by the second dose. Overall, the clinical use of Formulations A, B, C, or D will eliminate the need for combination oral therapy and reduce time to achieve steady state, with a smaller washout period upon cessation of therapy. Results of this study prove the suitability of using PLGA copolymers of varying composition and molecular weight to develop sustained release formulations that can tailor in vivo behavior and enhance pharmacological effectiveness of the drug. PMID:24616812

  12. Microspheres and nanoparticles from ultrasound

    NASA Astrophysics Data System (ADS)

    Suh, Won Hyuk

    Improved preparations of various examples of monodispersed, porous, hollow, and core-shell metal and semiconductor nanoparticles or nanowires have been developed. Now titania microspheres and nanoparticles and silica microspheres can be synthesized using an inexpensive high frequency (1.7 MHz) ultrasonic generator (household humidifier; ultrasonic spray pyrolysis; USP). Morphology and pore size of titania microspheres were controlled by the silica to Ti(IV) ratio and silica particle size. Fine tuning the precursor ratio affords sub-50 nm titania nanoparticles as well. In terms of silica microspheres, morphology was controlled by the silica to organic monomer ratio. In liquids irradiated with high intensity ultrasound (20 kHz; HIUS), acoustic cavitation produces high energy chemistry through intense local heating inside the gas phase of collapsing bubbles in the liquid. HIUS and USP confine the chemical reactions to isolated sub-micron reaction zones, but sonochemistry does so in a heated gas phase within a liquid, while USP uses a hot liquid droplet carried by a gas flow. Thus, USP can be viewed as a method of phase-separated synthesis using submicron-sized droplets as isolated chemical reactors for nanomaterial synthesis. While USP has been used to create both titania and silica spheres separately, there are no prior reports of titania-silica composites. Such nanocomposites of metal oxides have been produced, and by further manipulation, various porous structures with fascinating morphologies were generated. Briefly, a precursor solution was nebulized using a commercially available household ultrasonic humidifier (1.7 MHz ultrasound generator), and the resulting mist was carried in a gas stream of air through a quartz glass tube in a hot furnace. After exiting the hot zone, these microspheres are porous or hollow and in certain cases magnetically responsive. In the case of titania microspheres, they are rapidly taken up into the cytoplasm of mammalian cells and

  13. Silver Clear Nylon Dressing is Effective in Preventing Radiation-Induced Dermatitis in Patients With Lower Gastrointestinal Cancer: Results From a Phase III Study

    SciTech Connect

    Niazi, Tamim M.; Vuong, Te; Azoulay, Laurant; Marijnen, Corrie; Bujko, Kryzstof; Nasr, Elie; Lambert, Christine; Duclos, Marie; Faria, Sergio; David, Marc; Cummings, Bernard

    2012-11-01

    Purpose: For patients with anal canal and advanced rectal cancer, chemoradiation therapy is a curative modality or an important adjunct to surgery. Nearly all patients treated with chemoradiation experience some degree of radiation-induced dermatitis (RID). Prevention and effective treatment of RID, therefore, is of considerable clinical relevance. The present phase III randomized trial compared the efficacy of silver clear nylon dressing (SCND) with that of standard skin care for these patients. Methods and Materials: A total of 42 rectal or anal canal cancer patients were randomized to either a SCND or standard skin care group. SCND was applied from Day 1 of radiation therapy (RT) until 2 weeks after treatment completion. In the control arm, sulfadiazine cream was applied at the time of skin dermatitis. Printed digital photographs taken 2 weeks prior to, on the last day, and two weeks after the treatment completion were scored by 10 blinded readers, who used the common toxicity scoring system for skin dermatitis. Results: The radiation dose ranged from 50.4 to 59.4 Gy, and there were no differences between the 2 groups. On the last day of RT, when the most severe RID occurs, the mean dermatitis score was 2.53 (standard deviation [SD], 1.17) for the standard and 1.67 (SD, 1.2; P=.01) for the SCND arm. At 2 weeks after RT, the difference was 0.39 points in favor of SCND (P=.39). There was considerable intraclass correlation among the 10 observers. Conclusions: Silver clear nylon dressing is effective in reducing RID in patients with lower gastrointestinal cancer treated with combined chemotherapy and radiation treatment.

  14. Natural history of pancreatitis-induced splenic vein thrombosis: a systematic review and meta-analysis of its incidence and rate of gastrointestinal bleeding

    PubMed Central

    Butler, James R; Eckert, George J; Zyromski, Nicholas J; Leonardi, Michael J; Lillemoe, Keith D; Howard, Thomas J

    2011-01-01

    Background Pancreatitis-induced splenic vein thrombosis (PISVT) is an acquired anatomic abnormality that impacts decision making in pancreatic surgery. Despite this influence, its incidence and the rate of associated gastrointestinal (GI) bleeding are imprecisely known. Methods The MEDLINE, EMBASE, Cochrane Central Register of Clinical Trials and Cochrane Database of Systematic Reviews databases were searched from their inception to June 2010 for abstracts documenting PISVT in acute (AP) or chronic pancreatitis (CP). Two reviewers independently graded abstracts for inclusion in this review. Heterogeneity in combining data was assumed prior to pooling. Random-effects meta-analyses were performed to estimate percentages and 95% confidence intervals. Results After review of 241 abstracts, 47 studies and 52 case reports were graded as relevant. These represent a cohort of 805 patients with PISVT reported in the literature. A meta-analysis of studies meeting inclusion criteria shows mean incidences of PISVT of 14.1% in all patients, 22.6% in patients with AP and 12.4% in patients with CP. The incidence of associated splenomegaly was only 51.9% in these patients. Varices were identified in 53.0% of patients and were gastric in 77.3% of cases. The overall rate of GI bleeding was 12.3%. Conclusions Although reported incidences of PISVT vary widely across studies, an overall incidence of 14.1% is reported. Splenomegaly is an unreliable sign of PISVT. Although the true natural history of PISVT remains unknown, the collective reported rate of associated GI bleeding is 12.3%. PMID:22081918

  15. Cross-Sectional Study for Prevalence of Non-Steroidal Anti-Inflammatory Drug-Induced Gastrointestinal, Cardiac and Renal Complications in India: Interim Report

    PubMed Central

    Chatterjee, Suparna; Dureja, Gur Prasad; Kadhe, Ganesh; Mane, Amey; Phansalkar, Abhay A.; Sawant, Sandesh; Kapatkar, Vaibhavi

    2015-01-01

    Background Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common therapeutic products used for the management of inflammation and pain. However, their use is associated with gastrointestinal (GI), cardiovascular and renal complications. Although prevalence data regarding NSAID-induced complications are available worldwide, but none of the study has assessed the prevalence of GI, cardiac and renal complications in India. This study aimed to assess the point prevalence of GI, cardiac and renal complications associated with the use of NSAIDs in India. The study also aimed to evaluate the association between the risk factors and GI, renal and cardiac complications in patients using NSAIDs. Methods This prospective, cross-sectional, multi-centric study was conducted in eight medical colleges across India (North, East, West, South and Central India). Data related to GI complications including gastric, duodenal and gastroduodenal erosions/ulcers/gastritis, renal complications including acute and chronic renal failure or cardiac complications including acute coronary syndrome (ACS), acute myocardial infarction (AMI) and cardiac failure, were collected from patients. Results The cut-off date for interim data analysis was July 7, 2014. A total of 2,140 patients out of 3,600 were enrolled from eight centers at the time of interim analysis. The NSAID-associated point prevalence of GI complications was 30.08%; cardiac complication was 42.77%; and renal complication was 27.88%. Conclusions Results of the present interim analysis show that the prevalence of GI, cardiac and renal complications among patients is high due to exaggerated usage; however, the final analysis would provide the overall prevalence of these complications.

  16. Gastrointestinal disorders - resources

    MedlinePlus

    Digestive disease - resources; Resources - gastrointestinal disorders ... org American Liver Foundation -- www.liverfoundation.org National Digestive Diseases Information Clearinghouse -- digestive.niddk.nih.gov

  17. The Gastrointestinal Microbiome

    PubMed Central

    Engen, Phillip A.; Green, Stefan J.; Voigt, Robin M.; Forsyth, Christopher B.; Keshavarzian, Ali

    2015-01-01

    The excessive use of alcohol is a global problem causing many adverse pathological health effects and a significant financial health care burden. This review addresses the effect of alcohol consumption on the microbiota in the gastrointestinal tract (GIT). Although data are limited in humans, studies highlight the importance of changes in the intestinal microbiota in alcohol-related disorders. Alcohol-induced changes in the GIT microbiota composition and metabolic function may contribute to the well-established link between alcohol-induced oxidative stress, intestinal hyperpermeability to luminal bacterial products, and the subsequent development of alcoholic liver disease (ALD), as well as other diseases. In addition, clinical and preclinical data suggest that alcohol-related disorders are associated with quantitative and qualitative dysbiotic changes in the intestinal microbiota and may be associated with increased GIT inflammation, intestinal hyperpermeability resulting in endotoxemia, systemic inflammation, and tissue damage/organ pathologies including ALD. Thus, gut-directed interventions, such as probiotic and synbiotic modulation of the intestinal microbiota, should be considered and evaluated for prevention and treatment of alcohol-associated pathologies. PMID:26695747

  18. Paraneoplastic thrombocytosis in gastrointestinal cancer.

    PubMed

    Baranyai, Zsolt; Jósa, Valéria; Tóth, Ambrus; Szilasi, Zsuzsanna; Tihanyi, Balazs; Zaránd, Attila; Harsanyi, Laszlo; Szállási, Zoltán

    2016-06-01

    It has been demonstrated recently in several solid tumors that thrombocytosis at diagnosis may correlate with tumor invasion, metastatic progression and worse outcome. Several details of the pathomechanism of the relationship of thrombocytosis and cancer have been elucidated; however, the complete process is not clearly understood. Several hypotheses have been proposed. Recently, it was suggested that in ovarian cancer elevated IL-6 production by the tumor may induce increased megakaryopoiesis via hepatic thrombopoietin production leading to thrombocytosis. The importance of the prognostic power of elevated platelet count is still debated in gastrointestinal cancer. The aims of this review were to evaluate the prognostic significance of thrombocytosis in gastrointestinal tumors, to see whether clinical practice confirmed the hypotheses and to reveal the causes of the inconsistent findings. PMID:27136385

  19. Gastrointestinal manifestations of food allergies.

    PubMed

    Wolfe, Jaime Liou; Aceves, Seema S

    2011-04-01

    The rates of eosinophilic gastrointestinal disorders appear to be increasing. The most common of these is eosinophilic esophagitis (EoE) which is a clinicopathologic condition consisting of characteristic symptoms and endoscopic features accompanied by a pan-esophageal, acid resistant epithelial eosinophilia of greater than equal to 15 per high power field. Typical symptoms include dysphagia and abdominal pain. Typical endoscopic features include pallor, plaques, furrows, concentric rings. Complications include food impactions and strictures. EoE resolution with food elimination diets provides evidence that EoE is a food-antigen driven process. In vitro and microarray studies have identified specific immunologic factors underlying EoE pathogenesis. Other gastrointestinal manifestations of food intolerances/allergy include food protein induced enterocolitis syndrome.

  20. Gastrointestinal malignancy and the microbiome.

    PubMed

    Abreu, Maria T; Peek, Richard M

    2014-05-01

    Microbial species participate in the genesis of a substantial number of malignancies-in conservative estimates, at least 15% of all cancer cases are attributable to infectious agents. Little is known about the contribution of the gastrointestinal microbiome to the development of malignancies. Resident microbes can promote carcinogenesis by inducing inflammation, increasing cell proliferation, altering stem cell dynamics, and producing metabolites such as butyrate, which affect DNA integrity and immune regulation. Studies in human beings and rodent models of cancer have identified effector species and relationships among members of the microbial community in the stomach and colon that increase the risk for malignancy. Strategies to manipulate the microbiome, or the immune response to such bacteria, could be developed to prevent or treat certain gastrointestinal cancers. PMID:24406471

  1. Paraneoplastic thrombocytosis in gastrointestinal cancer.

    PubMed

    Baranyai, Zsolt; Jósa, Valéria; Tóth, Ambrus; Szilasi, Zsuzsanna; Tihanyi, Balazs; Zaránd, Attila; Harsanyi, Laszlo; Szállási, Zoltán

    2016-06-01

    It has been demonstrated recently in several solid tumors that thrombocytosis at diagnosis may correlate with tumor invasion, metastatic progression and worse outcome. Several details of the pathomechanism of the relationship of thrombocytosis and cancer have been elucidated; however, the complete process is not clearly understood. Several hypotheses have been proposed. Recently, it was suggested that in ovarian cancer elevated IL-6 production by the tumor may induce increased megakaryopoiesis via hepatic thrombopoietin production leading to thrombocytosis. The importance of the prognostic power of elevated platelet count is still debated in gastrointestinal cancer. The aims of this review were to evaluate the prognostic significance of thrombocytosis in gastrointestinal tumors, to see whether clinical practice confirmed the hypotheses and to reveal the causes of the inconsistent findings.

  2. The Effect of Ergotamine on Tissue Blood Flow and the Arteriovenous Shunting of Radioactive Microspheres in the Head

    PubMed Central

    Johnston, Barbara M.; Saxena, P.R.

    1978-01-01

    1 The radioactive microsphere method was used to study the effects of ergotamine (5, 10 and 20 μg/kg, i.v.) on systemic and regional haemodynamic variables in chloralose-urethane anaesthetized cats. The influence of the drug was also studied on the number of 15 μm microspheres escaping entrapment in the head to emerge in the left external jugular vein. 2 Ergotamine decreased the heart rate and cardiac output. Since arterial blood pressure remained unchanged, calculated total peripheral resistance increased. 3 The regional distribution of cardiac output obtained with 15 μm microspheres agreed well with previous studies in cats where 25 μm spheres were used. The most pronounced difference was that in the present investigation more microspheres, apparently escaping through arteriovenous anastomoses (AVAs), were detected in the lungs than when larger spheres had been used. 4 Coronary blood flow decreased, while uterine blood flow was increased by the drug. The microsphere content of the lungs, which receive the spheres not only via bronchial arteries but also via AVAs, was greatly reduced by all doses of ergotamine. Ergotamine did not influence tissue blood flow to other major organs such as the brain, kidneys, skin, liver, skeletal muscle or the gastrointestinal tract. 5 In the 16 experiments, 0.46 ± 0.05 (s.e. mean)% of the total microspheres injected (equivalent to 11.7 ± 1.4% of microspheres detected in the left-side of the head) appeared within 2 min of microsphere injection into the left external jugular vein. The highest dose of ergotamine significantly reduced the shunting of the microspheres in the head. 6 Since 15 μm microspheres are only likely to reach the lungs by passing into the venous circulation through large glomus-type AVAs, we conclude that ergotamine reduces the fraction of microspheres appearing in the lungs by causing strong vasoconstriction in the AVAs in the head. 7 In conformity with the closure of head AVAs is the finding that

  3. Filling Porous Microspheres With Magnetic Material

    NASA Technical Reports Server (NTRS)

    Chang, Manchium; Colvin, Michael S.

    1990-01-01

    New process produces magnetic microspheres with controllable sizes, compositions, and properties for use in medical diagnostic tests, biological research, and chemical processes. Paramagnetic microspheres also made with process. Porous plastic microspheres prepared by polymerization of monomer in diluent by cross-linking agent. When diluent removed, it leaves tiny pores throughout polymerized spheres. Size and distribution of pores determined by amount and type of diluent and cross-linking agent.

  4. Microsphere coated substrate containing reactive aldehyde groups

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Richard C. K. (Inventor)

    1984-01-01

    A synthetic organic resin is coated with a continuous layer of contiguous, tangential, individual microspheres having a uniform diameter preferably between 100 Angstroms and 2000 Angstroms. The microspheres are an addition polymerized polymer of an unsaturated aldehyde containing 4 to 20 carbon atoms and are covalently bonded to the substrate by means of high energy radiation grafting. The microspheres contain reactive aldehyde groups and can form conjugates with proteins such as enzymes or other aldehyde reactive materials.

  5. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects.

    PubMed

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m(2)/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration.

  6. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects

    PubMed Central

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m2/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration. PMID:25609957

  7. Microvascular hemodynamics in experimental arthritis: disparity between the distribution of microspheres and plasma flow in bone.

    PubMed

    Hansen, E S; Søballe, K; Kjølseth, D; Henriksen, T B; He, S Z

    1990-09-01

    The microcirculation in normal and arthritic juxtaarticular bone was studied in 16 young dogs with carragheenan-induced arthritis of one knee. The regional blood flow was determined by the tissue uptake of intracardially injected 15-microns 141Ce-labeled microspheres, and the microvascular plasma volume was determined by the distribution space of circulating 125I-fibrinogen. Disparities between the distribution of plasma flow and microspheres, introduced by plasma skimming or nonentrapment of spheres in the intraosseous circulation, were estimated by 59Fe-transferrin, a third intravascular tracer, injected as a bolus intracardially and trapped peripherally after 15 sec by prompt circulatory arrest. The tissue uptake of the plasma flow tracer was compared to that of microspheres by the ratio between observed and expected activity of 59Fe-transferrin, the expected activity being calculated from the microsphere distribution. The transferrin and microsphere uptake agreed well in patella, marginal epiphyseal bone, and cortical bone, whereas observed activity of transferrin was twice the expected in central epiphyseal bone, three times higher in marrow, and up to eightfold higher in metaphyses adjacent to growth plates. This discrepancy was significantly greater in arthritic bone when the metaphyses were examined in toto. The microsphere method thus appears to underestimate blood flow to cancellous bone and marrow due to uneven distribution of plasma and formed elements from profound plasma skimming and perhaps also by AV shunting. PMID:2250600

  8. Investigation on efficient adsorption of cationic dyes on porous magnetic polyacrylamide microspheres.

    PubMed

    Yao, Tong; Guo, Song; Zeng, Changfeng; Wang, Chongqing; Zhang, Lixiong

    2015-07-15

    We report here the preparation of porous magnetic polyacrylamide microspheres for efficient removal of cationic dyes by a simple polymerization-induced phase separation method. Characterizations by various techniques indicate that the microspheres show porous structures and magnetic properties. They can adsorb methylene blue with high efficiency, with adsorption capacity increasing from 263 to 1977 mg/g as the initial concentration increases from 5 to 300 mg/L. Complete removal of methylene blue can be obtained even at very low concentrations. The equilibrium data is well described by the Langmuir isotherm models, exhibiting a maximum adsorption capacity of 1990 mg/g. The adsorption capacity increases with increasing initial pH and reaches a maximum at pH 8, revealing an electrostatic interaction between the microspheres and the methylene blue molecules. The microspheres also show high adsorption capacities for neutral red and gentian violet of 1937 and 1850 mg/g, respectively, as well as high efficiency in adsorption of mixed-dye solutions. The dye-adsorbed magnetic polyacrylamide microspheres can be easily desorbed, and can be repeatedly used for at least 6 cycles without losing the adsorption capacity. The adsorption capacity and efficiency of the microspheres are much higher than those of reported adsorbents, which exhibits potential practical application in removing cationic dyes.

  9. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects.

    PubMed

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m(2)/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration. PMID:25609957

  10. Glucagon-like peptide-2-loaded microspheres as treatment for ulcerative colitis in the murine model.

    PubMed

    Wu, Jie; Qi, Keke; Xu, Ziwei; Wan, Jin

    2015-01-01

    Glucagon-like peptide-2 (GLP-2) is an intestinal hormone that promotes intestinal growth, but the rapid degradation by dipeptidyl peptidase-IV limits its applications. PLGA microsphere is a well-developed drug delivery system, while seldom been studied as a solution for prolonging in vivo effects of GLP-2. In this study, we encapsulated porcine GLP-2 (pGLP-2) into microspheres and investigated its therapeutic effects in dextran sulfate sodium (DSS)-treated mice. pGLP-2 microspheres showed 20.36% in initial burst and constant release for at least 9 d. In the DSS-treated mice, a single injection of GLP-2 microspheres significantly increased the body weight, colonic length, small intestinal weight and mRNA expression of Occludin, decreased the colonic damage score, mRNA expression of IL-6, IL-10, TNF-α and IFN-γ. In conclusion, pGLP-2 microspheres were resistant to degradation and decreased the severity of DSS-induced ulcerative colitis which suggested that GLP-2-loaded microspheres could be a proper candidate for the treatment of ulcerative colitis.

  11. Patient Selection and Activity Planning Guide for Selective Internal Radiotherapy With Yttrium-90 Resin Microspheres

    SciTech Connect

    Lau, Wan-Yee; Kennedy, Andrew S.; Kim, Yun Hwan; Lai, Hee Kit; Lee, Rheun-Chuan; Leung, Thomas W.T.; Liu, Ching-Sheng; Salem, Riad; Sangro, Bruno; Shuter, Borys; Wang, Shih-Chang

    2012-01-01

    Purpose: Selective internal radiotherapy (SIRT) with yttrium-90 ({sup 90}Y) resin microspheres can improve the clinical outcomes for selected patients with inoperable liver cancer. This technique involves intra-arterial delivery of {beta}-emitting microspheres into hepatocellular carcinomas or liver metastases while sparing uninvolved structures. Its unique mode of action, including both {sup 90}Y brachytherapy and embolization of neoplastic microvasculature, necessitates activity planning methods specific to SIRT. Methods and Materials: A panel of clinicians experienced in {sup 90}Y resin microsphere SIRT was convened to integrate clinical experience with the published data to propose an activity planning pathway for radioembolization. Results: Accurate planning is essential to minimize potentially fatal sequelae such as radiation-induced liver disease while delivering tumoricidal {sup 90}Y activity. Planning methods have included empiric dosing according to degree of tumor involvement, empiric dosing adjusted for the body surface area, and partition model calculations using Medical Internal Radiation Dose principles. It has been recommended that at least two of these methods be compared when calculating the microsphere activity for each patient. Conclusions: Many factors inform {sup 90}Y resin microsphere SIRT activity planning, including the therapeutic intent, tissue and vasculature imaging, tumor and uninvolved liver characteristics, previous therapies, and localization of the microsphere infusion. The influence of each of these factors has been discussed.

  12. Dose-rate distribution of {sup 32}P-glass microspheres for intra-arterial brachytherapy

    SciTech Connect

    Guimaraes, Carla C.; Moralles, Mauricio; Sene, Frank F.; Martinelli, Jose R.

    2010-02-15

    Purpose: The intra-arterial administration of radioactive glass microspheres is an alternative therapy option for treating primary hepatocellular carcinoma, the main cause of liver cancer death, and metastatic liver cancer, another important kind of cancer induced in the liver. The technique involves the administration of radioactive microspheres in the hepatic artery, which are trapped preferentially in the tumor. Methods: In this work the GEANT4 toolkit was used to calculate the radial dose-rate distributions in water from {sup 32}P-loaded glass microspheres and also from {sup 90}Y-loaded glass microspheres. To validate the toolkit for this application, the authors compared the dose-rate distribution of {sup 32}P and {sup 90}Y point sources in water with data from the International Commission on Radiation Units and Measurements report 72. Results: Tables of radial dose-rate distributions are provided for practical use in brachytherapy planning with these microspheres. Conclusions: The simulations with the microspheres show that the shape of the beta ray energy spectra with respect to the {sup 32}P and {sup 90}Y sources is significantly modified by the glass matrix.

  13. Electrospray synthesis and properties of hierarchically structured PLGA TIPS microspheres for use as controlled release technologies.

    PubMed

    Malik, Salman A; Ng, Wing H; Bowen, James; Tang, Justin; Gomez, Alessandro; Kenyon, Anthony J; Day, Richard M

    2016-04-01

    Microsphere-based controlled release technologies have been utilized for the long-term delivery of proteins, peptides and antibiotics, although their synthesis poses substantial challenges owing to formulation complexities, lack of scalability, and cost. To address these shortcomings, we used the electrospray process as a reproducible, synthesis technique to manufacture highly porous (>94%) microspheres while maintaining control over particle structure and size. Here we report a successful formulation recipe used to generate spherical poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray (ES) coupled with a novel thermally induced phase separation (TIPS) process with a tailored Liquid Nitrogen (LN2) collection scheme. We show how size, shape and porosity of resulting microspheres can be controlled by judiciously varying electrospray processing parameters and we demonstrate examples in which the particle size (and porosity) affect release kinetics. The effect of electrospray treatment on the particles and their physicochemical properties are characterized by scanning electron microscopy, confocal Raman microscopy, thermogravimetric analysis and mercury intrusion porosimetry. The microspheres manufactured here have successfully demonstrated long-term delivery (i.e. 1week) of an active agent, enabling sustained release of a dye with minimal physical degradation and have verified the potential of scalable electrospray technologies for an innovative TIPS-based microsphere production protocol. PMID:26803601

  14. Preparation, drug releasing property and pharmacodynamics of soy isoflavone-loaded chitosan microspheres.

    PubMed

    Du, Zhongyan; Dou, Xiaobing; Huang, Chenyun; Gao, Jia; Hu, Linfeng; Zhu, Jiazhen; Qian, Ying; Dou, Minhua; Fan, Chunlei

    2013-01-01

    Soybean isoflavone (SIF) has anti-aging properties and many other biological functions; however, SIF is difficult to reach higher blood concentration due to its rapid metabolism. Therefore, it is of great value to design and produce a sustained-release formulation that is able to maintain a stable level of plasma concentrations. In this paper, soybean isoflavone sustained-release microsphere from chitosan and sodium alginate was prepared successfully. The important factors that determined the quality of the microspheres were the sodium alginate concentration in solution B, the ratio of soybean isoflavone to chitosan and the mixing speed. The relative yield, encapsulation efficiency and drug loading capability of SIF were much higher than the existing commercial formulations. In real gastrointestinal conditions, compared with the non-sustained release group, the release rate of SIF slowed down and the reaction time was prolonged. Animal experiments showed that sustained-release microspheres intensified the anti-aging potentials of SIF. Compared with the Non-sustained release (NSR) group mice, oral SIF/CHI microsphere treated mice were better in the Morris Water Maze Test (MWMT), the MDA level in the both plasma and brain of the sustained release (SR) group mice decreased, and SOD content was remarkably improved.

  15. Oral Delivery of Exenatide via Microspheres Prepared by Cross-Linking of Alginate and Hyaluronate

    PubMed Central

    Zhang, Baojie; He, Dongyang; Fan, Yu; Liu, Nan; Chen, Yijun

    2014-01-01

    Exenatide is an FDA-approved glucose-lowering peptide drug for the treatment of type 2 diabetes by subcutaneous injection. To address the issues on the inconvenience for patient use and the difficulty of oral administration of peptide drugs, chemical cross-linking of two pH-responsive biomaterials, alginate and hyaluronate, was carried out to prepare a new material for the encapsulation of exenatide as a form of microspheres. The exenatide-loaded microspheres exhibited spherical structures with excellent loading and release behaviors in the simulated gastrointestinal tract environments. After oral administration of the microspheres in db/db mice, maximum plasma concentration of exenatide appeared at 4 hours, and blood glucose was effectively reduced to a normal level within 2 hours and maintained for another 4 hours. The bioavailability of the exenatide-loaded microspheres, relative to subcutaneous injection of exenatide, reached 10.2%. Collectively, the present study demonstrated the feasibility of orally delivering exenatide with the new cross-linked biomaterial and formulation, and showed therapeutic potential for clinical applications. PMID:24465870

  16. Glass microspheres for medical applications

    NASA Astrophysics Data System (ADS)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in <1 week, without causing any detectable joint damage. The combination of dysprosium lithium borate glass microspheres and EDTA chelation therapy provides an unique "tool" for the medical community, which can deliver a large dose (>100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass

  17. Coupling system to a microsphere cavity

    NASA Technical Reports Server (NTRS)

    Iltchenko, Vladimir (Inventor); Maleki, Lute (Inventor); Yao, Steve (Inventor); Wu, Chi (Inventor)

    2002-01-01

    A system of coupling optical energy in a waveguide mode, into a resonator that operates in a whispering gallery mode. A first part of the operation uses a fiber in its waveguide mode to couple information into a resonator e.g. a microsphere. The fiber is cleaved at an angle .PHI. which causes total internal reflection within the fiber. The energy in the fiber then forms an evanescent field and a microsphere is placed in the area of the evanescent field. If the microsphere resonance is resonant with energy in the fiber, then the information in the fiber is effectively transferred to the microsphere.

  18. Compression molding of aerogel microspheres

    DOEpatents

    Pekala, Richard W.; Hrubesh, Lawrence W.

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

  19. Compression molding of aerogel microspheres

    DOEpatents

    Pekala, R.W.; Hrubesh, L.W.

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

  20. The design of pH-sensitive chitosan-based formulations for gastrointestinal delivery.

    PubMed

    Du, Hongliang; Liu, Mengrui; Yang, Xiaoye; Zhai, Guangxi

    2015-08-01

    Chitosan, a nontoxic and biocompatible polysaccharide, has been widely explored for the gastrointestinal delivery of drugs, proteins, peptides and genes for different therapeutic purposes. Because a pH gradient exists in the gastrointestinal tract, chitosan-based formulations in response to specific pH conditions, such as the low pH in the stomach and a high pH in the intestine, have been developed as a general strategy for disease diagnosis and therapy. Tailored pH-responsive drug release in the gastrointestinal tract can be achieved with various chitosan-based formulations such as nanoparticles, microspheres, hydrogels and nanocomposites. This review focuses on the most recent development of chitosan-based pH-sensitive formulations for gastrointestinal delivery, covering various types of chitosan-based formulations, their pH-responsive mechanisms and biomedical applications.

  1. Nonaggregating Microspheres Containing Aldehyde Groups

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan

    1989-01-01

    Cobalt gamma irradiation of hydrophilic monomers in presence of acrolein yields exceptionally-stable, nonaggregating microspheres. Mixtures of 2-hydroxyethyl methacrylate (HEMA) and acrolein form homogeneous solutions in distilled water containing 0.4 percent polyethylene oxide (PEO). After deaeration with nitrogen, mixtures irradiated at room temperature with gamma rays from cobalt source; total exposure time 4 hours, at rate of 0.2 milliroentgen per hour. Reaction product centrifuged three times for purification and kept in distilled water.

  2. Microspheres in Plasma Display Panels

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Filling small bubbles of molten glass with gases is just as difficult as it sounds, but the technical staff at NASA is not known to shy away from a difficult task. When Microsphere Systems, Inc. (MSI), of Ypsilanti, Michigan, and Imaging Systems Technology, Inc. (IST), of Toledo, Ohio, were trying to push the limits of plasma displays but were having difficulty with the designs, NASA s Glenn Garrett Morgan Commercialization Initiative (GMCI) assembled key personnel at Glenn Research Center and Ohio State University for a brainstorming session to come up with a solution for the companies. They needed a system that could produce hollow, glass micro-sized spheres (microspheres) that could be filled with a variety of gasses. But the extremely high temperature required to force the micro-sized glass bubbles to form at the tip of a metal nozzle resulted in severe discoloration of the microspheres. After countless experiments on various glass-metal combinations, they had turned to the GMCI for help. NASA experts in advanced metals, ceramics, and glass concluded that a new design approach was necessary. The team determined that what was needed was a phosphate glass composition that would remain transparent, and they went to work on a solution. Six weeks later, using the design tips from the NASA team, Tim Henderson, president of MSI, had designed a new system in which all surfaces in contact with the molten glass would be ceramic instead of metal. Meanwhile, IST was able to complete a Phase I Small Business Innovation Research (SBIR) grant supported by the National Science Foundation (NSF) and supply a potential customer with samples of the microspheres for evaluation as filler materials for high-performance insulations.

  3. [Functional gastrointestinal disorders].

    PubMed

    Vogt, W

    2007-11-21

    Functional gastrointestinal disorders particularly dyspepsia an irritable bowel syndrome are frequent problems for the general practitioner and also for the specialist. Both are diseases and not only a kind of discomfort. The high frequency of dispepsia and irritable bowel syndrome induces very high direct and indirect charges. Both diseases depend on a number of factors or causes, for whom the evidence is not good. But there are good experimental data for the visceral hypersensitivity as one of the main factors. Gastroscopy is the most important examination in the diagnosis of dyspepsia. Endoscopy has to be done in all patients with alarm symptoms an in all patients older than 45 years. The therapy of dyspepsia is an empirical one. The eradication of Helicobacter pylori is a therapeutical option, but only 8% of the patients will have benefit for a long time. Other therapeutical options are the use of proton-pump inhibitors, prokinetics or phytotherapeutics. The therapy of the irritable bowel syndrome depends on the subtype of the disease (diarrhea, constipation, abdominal pain, bloating). First of all a good doctor-patient relationship is mandatory. Furthermore the use of dietary fibre, antidiarrhoeics, laxatives and muscle relaxants may be beneficial. And phytotherapeutics can be an additional therapeutic approach.

  4. Polymethyl methacrylate microspheres in collagen.

    PubMed

    Haneke, Eckart

    2004-12-01

    Artecoll was developed about 20 years ago and underwent a number of production changes until it recently became FDA approved under the new name of Artefill. This product contains 20% polymethyl methacrylate (PMMA) microspheres with a diameter of 30 to 40 microm, which are suspended in a 3.5% atelo-collagen solution. The PMMA microspheres are now purified and no longer have an electrostatic charge, which in part was the cause for the early granulomatous reactions. Further, PMMA has long been known as bone cement and has been used in cosmetic surgery with a very good safety record. PMMA microspheres are biologically inert and nondegradable. The treatment results are therefore permanent and technical errors as well as incorrect injections will last. Due to the early record of granuloma formation, there is still a debate as to whether this product-as well as all other permanent fillers-should be injected for cosmetic reasons or not. With proper indications, excellent injection techniques, and realistic expectations as to what can be expected, this product has now proved to be one of the superior permanent filler substances.

  5. Classification of eosinophilic gastrointestinal diseases.

    PubMed

    Mueller, Susanna

    2008-01-01

    Diagnosis of eosinophilic gastrointestinal diseases is based on morphological evaluation with regard to localization and density of eosinophil infiltration of the mucosa and/or deeper parts of the oesophagus, stomach, and bowel in biopsy or resection specimens. As with eosinophils in any tissue, in the majority of diseases they are probably a sequel of acute inflammation and do not indicate any specific disease. Eosinophil morphology includes intact cells with bilobated nuclei and eosinophil granules in the cytoplasm and extracellular tissue following activation/degranulation. There is no fixed number of eosinophils that can be used as a cut-off criterion to define disease. Associated histopathological features observed in eosinophilic gastrointestinal disease depend on the site of manifestation and primary disease. Eosinophils are typically increased in allergy-associated colitis in adults and allergic proctocolitis in infants, eosinophilic gastroenteritis and eosinophilic oesophagitis. Their presence can also suggest a drug-induced eosinophilia or the presence of a parasitic infection. In general, eosinophils are increased in inflammatory bowel disease (IBD). They are seen in reflux oesophagitis, coeliac disease, and microscopic and infectious colitis. Eosinophils may be a feature of polyarteriitis nodosa and Churg-Strauss syndrome, and can accompany connective-tissue disease as well as malignant lymphomas and adenocarcinomas of gastrointestinal mucosa. PMID:18492564

  6. A pilot-scale study of Cryptosporidium-sized microsphere removals from swimming pools via sand filtration.

    PubMed

    Lu, Ping; Amburgey, James E

    2016-02-01

    Cryptosporidium species are the most common cause of gastrointestinal illness in treated recreational water venues. In order to protect public health during swimming, Cryptosporidium-sized microsphere removals by high-rate sand filtration with six coagulants were evaluated with a 5.5 m(3) pilot-scale swimming pool. A sand filter without coagulation removed 20-63% of Cryptosporidium-sized microspheres. Cryptosporidium-sized microsphere removals exceeded 98% by sand filtration with five of the six tested coagulants. Continuously feeding coagulants A, B, and F (i.e., organic polymers) led to coagulant accumulation in the system and decreased removals over time (<2 days). Coagulant E (polyaluminum chloride) consistently removed more than 90% of microspheres at 30 m/h while the removals dropped to approximately 50% at a filtration rate of 37 m/h. Coagulant C was a chitosan-based product that removed fewer microspheres compared with other products, <75%, under the studied conditions. Results indicated aluminum-based coagulants (coagulants D and E) had an overall performance advantage over the organic polymer based coagulants primarily in terms of their tendency not to accumulate in the water and cease to be effective at improving filter efficiency.

  7. A pilot-scale study of Cryptosporidium-sized microsphere removals from swimming pools via sand filtration.

    PubMed

    Lu, Ping; Amburgey, James E

    2016-02-01

    Cryptosporidium species are the most common cause of gastrointestinal illness in treated recreational water venues. In order to protect public health during swimming, Cryptosporidium-sized microsphere removals by high-rate sand filtration with six coagulants were evaluated with a 5.5 m(3) pilot-scale swimming pool. A sand filter without coagulation removed 20-63% of Cryptosporidium-sized microspheres. Cryptosporidium-sized microsphere removals exceeded 98% by sand filtration with five of the six tested coagulants. Continuously feeding coagulants A, B, and F (i.e., organic polymers) led to coagulant accumulation in the system and decreased removals over time (<2 days). Coagulant E (polyaluminum chloride) consistently removed more than 90% of microspheres at 30 m/h while the removals dropped to approximately 50% at a filtration rate of 37 m/h. Coagulant C was a chitosan-based product that removed fewer microspheres compared with other products, <75%, under the studied conditions. Results indicated aluminum-based coagulants (coagulants D and E) had an overall performance advantage over the organic polymer based coagulants primarily in terms of their tendency not to accumulate in the water and cease to be effective at improving filter efficiency. PMID:26837835

  8. Optical microdiscus resonators by flattening microspheres

    NASA Astrophysics Data System (ADS)

    Senthil Murugan, Ganapathy; Wilkinson, James S.; Zervas, Michalis N.

    2012-08-01

    A "soften-and-squash" fabrication technique has been demonstrated to controllably deform optical microspheres and form microdiscus resonators with improved surface quality. The characteristic shape of the microdiscus results in superior mode control, and the annealing involved in the fabrication process leads to quality factors (Q) exceeding 105, which is about two orders of magnitude higher than the initial microspheres.

  9. Magnetically separable and recyclable Fe3O4-polydopamine hybrid hollow microsphere for highly efficient peroxidase mimetic catalysts.

    PubMed

    Liu, Shujun; Fu, Jianwei; Wang, Minghuan; Yan, Ya; Xin, Qianqian; Cai, Lu; Xu, Qun

    2016-05-01

    Magnetic Fe3O4-polydopamine (PDA) hybrid hollow microspheres, in which Fe3O4 nanoparticles were firmly incorporated in the cross-linked PDA shell, have been prepared through the formation of core/shell PS/Fe3O4-PDA composites based on template-induced covalent assembly method, followed by core removal in a tetrahydrofuran solution. The morphology, composition, thermal property and magnetic property of the magnetic hybrid hollow microspheres were characterized by SEM, TEM, FT-IR, XRD, TGA, and vibrating sample magnetometer, respectively. Results revealed that the magnetic hybrid hollow microspheres had about 380 nm of inner diameter and about 30 nm of shell thickness, and 13.6 emu g(-1) of magnetization saturation. More importantly, the Fe3O4-PDA hybrid hollow microspheres exhibited intrinsic peroxidase-like activity, as they could quickly catalyze the oxidation of typical substrates 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. Compared with PDA/Fe3O4 composites where Fe3O4 nanoparticles were loaded on the surface of PDA microspheres, the stability of Fe3O4-PDA hybrid hollow microspheres was greatly improved. As-prepared magnetic hollow microspheres might open up a new application field in biodetection, biocatalysis, and environmental monitoring.

  10. MRI traceability of superparamagnetic iron oxide nanoparticle-embedded chitosan microspheres as an embolic material in rabbit uterus

    PubMed Central

    Choi, Sun Young; Kwak, Byung Kook; Shim, Hyung Jin; Lee, Jaehwi; Hong, Soon Uk; Kim, Kyung Ah

    2015-01-01

    PURPOSE We aimed to compare polyvinyl alcohol (PVA) particles with calibrated superparamagnetic iron oxide (SPIO) nanoparticle-loaded chitosan microspheres in a rabbit model, specifically regarding the relative distribution of embolic agents within the uterus based on magnetic resonance imaging (MRI) and pathological evaluation. METHODS Twelve New Zealand white rabbits underwent uterine artery embolization using either standard PVA particles (45–150 µm or 350–500 µm) or calibrated SPIO-embedded chitosan microspheres (45–150 µm or 300–500 µm). MRI and histopathological findings were compared one week after embolization. RESULTS Calibrated SPIO-loaded chitosan microspheres 45–150 µm in size were detected on T2-weighted images. On histological analysis, calibrated SPIO-embedded chitosan microspheres were found in both myometrium and endometrium, whereas PVA particles were found only in the perimyometrium or extrauterine fat pads. A proportional relationship was noted between the calibrated SPIO-embedded chitosan microsphere size and the size of the occluded artery. CONCLUSION Calibrated SPIO-embedded chitosan microspheres induced greater segmental arterial occlusion than PVA particles and showed great potential as a new embolic material. SPIO-embedded chitosan microspheres can be used to follow distribution of embolic particles through MRI studies. PMID:25333216

  11. Budesonide-loaded guar gum microspheres for colon delivery: preparation, characterization and in vitro/in vivo evaluation.

    PubMed

    Liu, Ye; Zhou, Hong

    2015-01-26

    A novel budesonide (BUD) colon delivery release system was developed by using a natural polysaccharide, guar gum. The rigidity of the microspheres was induced by a chemical cross-linking method utilizing glutaraldehyde as the cross-linker. The mean particle size of the microspheres prepared was found to be 15.21 ± 1.32 µm. The drug loading and entrapment efficiency of the formulation were 17.78% ± 2.31% and 81.6% ± 5.42%, respectively. The microspheres were spherical in shape with a smooth surface, and the size was uniform. The in vitro release profiles indicated that the release of BUD from the microspheres exhibited a sustained release behavior. The model that fitted best for BUD released from the microspheres was the Higuchi kinetic model with a correlation coefficient r = 0.9993. A similar phenomenon was also observed in a pharmacokinetic study. The prolongation of the half-life (t1/2), enhanced residence time (mean residence time, MRT) and decreased total clearance (CL) indicated that BUD microspheres could prolong the acting time of BUD in vivo. In addition, BUD guar gum microspheres are thought to have the potential to maintain BUD concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. None of the severe signs, like the appearance of epithelial necrosis and the sloughing of epithelial cells, were detected.

  12. Preparation of floating microspheres for fish farming.

    PubMed

    Nepal, Pushp R; Chun, Myung-Kwan; Choi, Hoo-Kyun

    2007-08-16

    The aim of this study was to develop floating microspheres with practical applications to fish farming. Each microsphere with a central hollow cavity was prepared using a solvent diffusion and evaporation method with Eudragit E100. Various manufacturing parameters were investigated by single factor method. The macrolide antibiotic josamycin was selected as a model drug. The loading efficiency of the drug in the microspheres was 64.7%. In the release study, virtually none of the drug was released into the fresh water whereas the entire drug was released from the josamycin-loaded microspheres into the simulated gastric fluid of rainbow trout (pH 2.7). The buoyancy was excellent with approximately 90% of the microspheres still floating after 24h.

  13. Multiplexed Microsphere Suspension Array-Based Immunoassays.

    PubMed

    Lin, Andrew; Salvador, Alexandra; Carter, J Mark

    2015-01-01

    ELISA is an extremely powerful tool to detect analytes because of its sensitivity, selectivity, reproducibility and ease of use. Here we describe sandwich immunoassays performed in suspension on spectrally unique microspheres developed by Luminex. Luminex assays offer the benefit of multiplex analysis of large numbers of analytes in a single reaction. Because the microspheres are spectrally unique, many microspheres, each attached to various antibodies, can be added to a single sample. Luminex instruments can distinguish each microsphere and detect the intensity of a reporter signal for each microsphere. Results are reported in Median Fluorescent Intensities for each analyte. Luminex assays can be used to detect up to 500 analytes in a high-throughput format. Luminex refers to this technology as xMAP(®). Here we describe a routine protocol for a Luminex immunoassay. Other Luminex assays would have to be optimized for specific conditions according to their use. PMID:26160569

  14. Gastrointestinal motility and functional gastrointestinal diseases.

    PubMed

    Kusano, Motoyasu; Hosaka, Hiroko; Kawada, Akiyo; Kuribayashi, Shiko; Shimoyama, Yasuyuki; Zai, Hiroaki; Kawamura, Osamu; Yamada, Masanobu

    2014-01-01

    Digestive tract motility patterns are closely related to the pathophysiology of functional gastrointestinal diseases (FGID), and these patterns differ markedly between the interdigestive period and the postprandial period. The characteristic motility pattern in the interdigestive period is so-called interdigestive migrating contraction (IMC). IMCs have a housekeeping role in the intestinal tract, and could also be related to FGID. IMCs arising from the stomach are called gastrointestinal IMCs (GI-IMC), while IMCs arising from the duodenum without associated gastric contractions are called intestinal IMCs (I-IMC). It is thought that I-IMCs are abnormal in FGID. Transport of food residue to the duodenum via gastric emptying is one of the most important postprandial functions of the stomach. In patients with functional dyspepsia (FD), abnormal gastric emptying is a possible mechanism of gastric dysfunction. Accordingly, delayed gastric emptying has attracted attention, with prokinetic agents and herbal medicines often being administered in Japan to accelerate gastric emptying in patients who have anorexia associated with dyspepsia. Recently, we found that addition of monosodium L-glutamate (MSG) to a high-calorie liquid diet rich in casein promoted gastric emptying in healthy men. Therefore, another potential method of improving delayed gastric emptying could be activation of chemosensors that stimulate the autonomic nervous system of the gastrointestinal tract, suggesting a role for MSG in the management of delayed gastric emptying in patients with FD.

  15. Microsphere-based scaffolds encapsulating chondroitin sulfate or decellularized cartilage.

    PubMed

    Gupta, Vineet; Tenny, Kevin M; Barragan, Marilyn; Berkland, Cory J; Detamore, Michael S

    2016-09-01

    Extracellular matrix materials such as decellularized cartilage (DCC) and chondroitin sulfate (CS) may be attractive chondrogenic materials for cartilage regeneration. The goal of the current study was to investigate the effects of encapsulation of DCC and CS in homogeneous microsphere-based scaffolds, and to test the hypothesis that encapsulation of these extracellular matrix materials would induce chondrogenesis of rat bone marrow stromal cells. Four different types of homogeneous scaffolds were fabricated from microspheres of poly(D,L-lactic-co-glycolic acid): Blank (poly(D,L-lactic-co-glycolic acid) only; negative control), transforming growth factor-β3 encapsulated (positive control), DCC encapsulated, and CS encapsulated. These scaffolds were then seeded with rat bone marrow stromal cells and cultured for 6 weeks. The DCC and CS encapsulation altered the morphological features of the microspheres, resulting in higher porosities in these groups. Moreover, the mechanical properties of the scaffolds were impacted due to differences in the degree of sintering, with the CS group exhibiting the highest compressive modulus. Biochemical evidence suggested a mitogenic effect of DCC and CS encapsulation on rat bone marrow stromal cells with the matrix synthesis boosted primarily by the inherently present extracellular matrix components. An important finding was that the cell seeded CS and DCC groups at week 6 had up to an order of magnitude higher glycosaminoglycan contents than their acellular counterparts. Gene expression results indicated a suppressive effect of DCC and CS encapsulation on rat bone marrow stromal cell chondrogenesis with differences in gene expression patterns existing between the DCC and CS groups. Overall, DCC and CS were easily included in microsphere-based scaffolds; however, there is a requirement to further refine their concentrations to achieve the differentiation profiles we seek in vitro. PMID:27358376

  16. Multiple gastrointestinal atresias in two consecutive siblings.

    PubMed

    Gahukamble, D B; Gahukamble, L D

    2002-03-01

    Two consecutive female siblings with multiple gastrointestinal atresias are described. The history of consanguinity in the parents and the presence of extensive typical pathological lesions suggest a genetically-induced developmental fault in the alimentary tract during the early embryonic period.

  17. In vitro evaluation and intra-articular administration of biodegradable microspheres containing naproxen sodium.

    PubMed

    Bozdağ, S; Caliş, S; Kaş, H S; Ercan, M T; Peksoy, I; Hincal, A A

    2001-01-01

    The dispersion of non-steroidal antiinflammatory drugs (NSAIDs) into biodegradable polymeric matrices have been accepted as a good approach for obtaining a therapeutic effect in a predetermined period of time meanwhile minimizing the side effects of NSAIDs. In the present study, it was aimed to prepare Naproxen Sodium (NS), (a NSAID) loaded microsphere formulation using natural Bovine Serum Albumin (BSA) and synthetic biodegradable polymers such as poly(lactide-co-glycolic acid) (PLGA) (50:50 MW 34,000 and 88,000 Da) for intra-articular administration, and to study the retention of the drug at the site of injection in the knee joint. NS incorporated microspheres were evaluated in vitro for particle size (the mean particle size; for BSA microspheres, 10.0 +/- 0.3 microm, for PLGA microspheres, 9.0 +/- 0.2 and 5.0 +/- 0.1 microm for MW 34,000 and 88,000 Da, respectively), yield value, drug loading, surface morphology and drug release. For in vivo studies, monoarticular arthritis was induced in the left knee joints of rabbits by using ovalbumin and Freund's Complete Adjuvant as antigen and adjuvant. A certain time (4 days) is allowed for the formation of arthritis in the knee joints, then the NS loaded microspheres were injected directly into the articular cavity. At specific time points, gamma scintigrams were obtained to determine the residence time of the microspheres in knee joints, in order to determine the most suitable formulation. This study indicated that PLGA, a synthetic polymer, is more promising than the natural type BSA microspheres for an effective cure of mono-articular arthritis in rabbits.

  18. Solid evacuated microspheres of hydrogen

    DOEpatents

    Turnbull, Robert J.; Foster, Christopher A.; Hendricks, Charles D.

    1982-01-01

    A method is provided for producing solid, evacuated microspheres comprised of hydrogen. The spheres are produced by forming a jet of liquid hydrogen and exciting mechanical waves on the jet of appropriate frequency so that the jet breaks up into drops with a bubble formed in each drop by cavitation. The drops are exposed to a pressure less than the vapor pressure of the liquid hydrogen so that the bubble which is formed within each drop expands. The drops which contain bubbles are exposed to an environment having a pressure just below the triple point of liquid hydrogen and they thereby freeze giving solid, evacuated spheres of hydrogen.

  19. Injectable calcium hydroxylapatite microspheres (Radiesse).

    PubMed

    Ridenour, Brock; Kontis, Theda C

    2009-05-01

    Injectable calcium hydroxylapatite (Radiesse) received FDA approval in 2006 for the correction of facial lipoatrophy and moderate to severe facial wrinkles. This product consists of microspheres of a synthetic bone suspended in a methylcellulose gel matrix. Because the product is thicker than the hyaluronic acids, it is used for the correction of moderate to severe wrinkles, such as deep nasolabial folds. It is also used "off-label" to treat multiple areas of the face, nose, and hands. Radiesse is injected into the subdermal plane, and correction lasts approximately 1 year after injection.

  20. Nuclear fuel microsphere gamma analyzer

    DOEpatents

    Valentine, Kenneth H.; Long, Jr., Ernest L.; Willey, Melvin G.

    1977-01-01

    A gamma analyzer system is provided for the analysis of nuclear fuel microspheres and other radioactive particles. The system consists of an analysis turntable with means for loading, in sequence, a plurality of stations within the turntable; a gamma ray detector for determining the spectrum of a sample in one section; means for analyzing the spectrum; and a receiver turntable to collect the analyzed material in stations according to the spectrum analysis. Accordingly, particles may be sorted according to their quality; e.g., fuel particles with fractured coatings may be separated from those that are not fractured, or according to other properties.

  1. Anti-hypertensive effect of oral controlled-release microspheres containing an ACE inhibitor (delapril hydrochloride) in rats.

    PubMed

    Akiyama, Y; Yoshioka, M; Horibe, H; Inada, Y; Hirai, S; Kitamori, N; Toguchi, H

    1994-08-01

    An oral controlled-release drug delivery system based on microspheres of polyglycerol esters of fatty acids (PGEFs), was applied to an anti-hypertensive, delapril hydrochloride. The in-vitro release profile was controlled by selecting a PGEF with an appropriate hydrophilic-lipophilic balance value for the matrix. The microspheres from which 80% of the drug was released in 6 h were orally administered to rats. The plasma concentration of the active metabolite was sustained after administration of the microspheres in comparison with administration of a solution. The in-vivo release profile was in good agreement with the in-vitro release profile. When the microspheres were administered, the pharmacological effect of delapril hydrochloride on the angiotensin I-induced pressor response was also sustained showing consistency with the plasma concentration-time curve.

  2. Bisphosphonate release profiles from magnetite microspheres.

    PubMed

    Miyazaki, Toshiki; Inoue, Tatsuya; Shirosaki, Yuki; Kawashita, Masakazu; Matsubara, Takao; Matsumine, Akihiko

    2014-10-01

    Hyperthermia has been suggested as a novel, minimally invasive cancer treatment method. After implantation of magnetic nano- or microparticles around a tumour through blood vessels, irradiation with alternating magnetic fields facilitates the efficient in situ hyperthermia even for deep-seated tumours. On the basis of this idea, if the microspheres are capable of delivering drugs, they could be promising multifunctional biomaterials effective for chemotherapy as well as hyperthermia. In the present study, magnetite microspheres were prepared by aggregation of the iron oxide colloid in water-in-oil (W/O) emulsion. The release behaviour of alendronate, a typical bisphosphonate, from the microspheres was examined in vitro as a model of the bone tumour prevention and treatment system. The alendronate was successfully incorporated onto the porous magnetite microspheres in vacuum conditions. The drug-loaded microspheres maintained their original spherical shapes even after shaking in ultrapure water for 3 days, suggesting that they have sufficient mechanical integrity for clinical use. It was attributed to high aggregation capability of the magnetite nanoparticles through van der Waals and weak magnetic attractions. The microspheres showed slow release of the alendronate in vitro, resulting from tight covalent or ionic interaction between the magnetite and the alendronate. The release rate was diffusion-controlled type and well controlled by the alendronate concentration in drug incorporation to the microspheres.

  3. Bisphosphonate release profiles from magnetite microspheres.

    PubMed

    Miyazaki, Toshiki; Inoue, Tatsuya; Shirosaki, Yuki; Kawashita, Masakazu; Matsubara, Takao; Matsumine, Akihiko

    2014-10-01

    Hyperthermia has been suggested as a novel, minimally invasive cancer treatment method. After implantation of magnetic nano- or microparticles around a tumour through blood vessels, irradiation with alternating magnetic fields facilitates the efficient in situ hyperthermia even for deep-seated tumours. On the basis of this idea, if the microspheres are capable of delivering drugs, they could be promising multifunctional biomaterials effective for chemotherapy as well as hyperthermia. In the present study, magnetite microspheres were prepared by aggregation of the iron oxide colloid in water-in-oil (W/O) emulsion. The release behaviour of alendronate, a typical bisphosphonate, from the microspheres was examined in vitro as a model of the bone tumour prevention and treatment system. The alendronate was successfully incorporated onto the porous magnetite microspheres in vacuum conditions. The drug-loaded microspheres maintained their original spherical shapes even after shaking in ultrapure water for 3 days, suggesting that they have sufficient mechanical integrity for clinical use. It was attributed to high aggregation capability of the magnetite nanoparticles through van der Waals and weak magnetic attractions. The microspheres showed slow release of the alendronate in vitro, resulting from tight covalent or ionic interaction between the magnetite and the alendronate. The release rate was diffusion-controlled type and well controlled by the alendronate concentration in drug incorporation to the microspheres. PMID:24854985

  4. Seeing is believing, PLGA microsphere degradation revealed in PLGA microsphere/PVA hydrogel composites.

    PubMed

    Gu, Bing; Sun, Xuanhao; Papadimitrakopoulos, Fotios; Burgess, Diane J

    2016-04-28

    The aim of this study was to understand the polymer degradation and drug release mechanism from PLGA microspheres embedded in a PVA hydrogel. Two types of microspheres were prepared with different molecular weight PLGA polymers (approximately 25 and 7 kDa) to achieve different drug release profiles, with a 9-day lag phase and without a lag phase, respectively. The kinetics of water uptake into the microspheres coincided with the drug release profiles for both formulations. For the 25 kDa microspheres, minimal water uptake was observed in the early part of the lag phase followed by substantial water uptake at the later stages and in the drug release phase. For the 7 kDa microspheres, water uptake occurred simultaneously with drug release. Water uptake was approximately 2-3 times that of the initial microsphere weight for both formulations. The internal structure of the PLGA microspheres was evaluated using low temperature scanning electron microscopy (cryo-SEM). Burst drug release occurred followed by pore forming from the exterior to the core of both microspheres. A well-defined hydrogel/microsphere interface was observed. For the 25 kDa microspheres, internal pore formation and swelling occurred before the second drug release phase. The surface layer of the microspheres remained intact whereas swelling, and degradation of the core continued throughout the drug release period. In addition, microsphere swelling reduced glucose transport through the coatings in PBS media and this was considered to be a as a consequence of the increased thickness of the coatings. The combination of the swelling and microdialysis results provides a fresh understanding on the competing processes affecting molecular transport of bioanalytes (i.e. glucose) through these composite coatings during prolonged exposure in PBS. PMID:26965956

  5. Aceclofenac microspheres: quality by design approach.

    PubMed

    Deshmukh, Rameshwar K; Naik, Jitendra B

    2014-03-01

    The purpose of this study was to prepare polymeric microspheres containing aceclofenac by single emulsion [oil-in-water (o/w)] solvent evaporation method. Two biocompatible polymers, ethylcellulose, and Eudragit® RS100 were used in combination. Seven processing factors were investigated by Plackett-Burman design (PBD) in order to enhance the encapsulation efficiency of the microspheres. A Plackett-Burman design was employed by using the Design-Expert® software (Version-8.0.7.1). The resultant microspheres were characterized for their size, morphology, encapsulation efficiency, and drug release. Imaging of particles was performed by field emission scanning electron microscopy. Interaction between the drug and polymers were investigated by Fourier transform infrared (FTIR) spectroscopy, and X-ray powder diffractometry (XRPD). Graphical and mathematical analyses of the design showed that Eudragit® RS100, and polyvinyl alcohol (PVA) were significant negative effect on the encapsulation efficiency and identified as the significant factor determining the encapsulation efficiency of the microspheres. The low magnitudes of error and the significant values of R(2) in the present investigation prove the high prognostic ability of the design. The microspheres showed high encapsulation efficiency (70.15% to 83.82%). The microspheres were found to be discrete, oval with smooth surface. The FTIR analysis confirmed the compatibility of aceclofenac with the polymers. The XRPD revealed the dispersion of drug within microspheres formulation. Perfect prolonged drug release profile over 12h was achieved by a combination of ethylcellulose, and Eudragit® RS100 polymers. In conclusion, polymeric microspheres containing aceclofenac can be successfully prepared using the technique of experimental design, and these results helped in finding the optimum formulation variables for encapsulation efficiency of microspheres. PMID:24433918

  6. Enhanced humoral and cell-mediated immune responses generated by cationic polymer-coated PLA microspheres with adsorbed HBsAg.

    PubMed

    Chen, Xiaoming; Liu, Yuying; Wang, Lianyan; Liu, Yuan; Zhang, Weifeng; Fan, Bei; Ma, Xiaowei; Yuan, Qipeng; Ma, Guanghui; Su, Zhiguo

    2014-06-01

    Surface-engineered particulate delivery systems for vaccine administration have been widely investigated in experimental and clinical studies. However, little is known about charge-coated microspheres as potential recombinant subunit protein antigen delivery systems in terms of adsorption and related immune responses. In the present study, cationic polymers, including chitosan (CS), chitosan chloride (CSC), and polyethylenimine (PEI), were used to coat PLA microspheres to build positively charged surfaces. Antigen adsorption capacity was enhanced with increased surface charge of coated microspheres. In macrophages, HBsAg adsorbed on the surface of cationic microspheres specifically enhanced antigen uptake and augmented CD86, MHC I, and MHC II expression and IL-1β, IL-6, TNF-α, and IL-12 release. Antigens were more likely to localize independent of lysosomes after phagocytosis in antigen-attached cationic microsphere formulations. After intraperitoneal immunization, cationic microsphere-based vaccine formulations generated a rapid and efficient humoral immune response and cytokine release as compared with aluminum-adsorbed vaccine and free antigens in vivo. Moreover, microspheres coated with cationic polymers with relatively high positive charges and higher antigen adsorption exhibited strong stimulation of the Th1 response. In conclusion, PLA microspheres coated with cationic polymers may be a potential recombinant antigen delivery system to induce strong cell and humoral immune responses.

  7. Chemical composition of plasma treated polyimide microspheres

    NASA Astrophysics Data System (ADS)

    Gawdzik, Barbara; Sobiesiak, Magdalena

    2003-05-01

    Synthetic carbon microspheres for chromatography were obtained from porous copolymer of 4,4'-bis(maleimidodiphenyl)methane (BM) and divinylbenzene (DVB) using arc discharge argon plasma treatment. Chemical structure of the obtained material was determined by elemental analysis, scanning electron microscopy with X-ray detector, acid and base titrations, and atomic absorption spectroscopy. The results suggest that the carbon microspheres contain copper coming from the plasma reactor electrodes. To remove it two complexion agents were used: EDTA and 20% HNO 3. Copper can be removed from the surface using these methods. The other amount was permanently built into internal structure of the microspheres.

  8. Rutin-loaded chitosan microspheres: Characterization and evaluation of the anti-inflammatory activity.

    PubMed

    Cosco, Donato; Failla, Paola; Costa, Nicola; Pullano, Salvatore; Fiorillo, Antonino; Mollace, Vincenzo; Fresta, Massimo; Paolino, Donatella

    2016-11-01

    Rutin was microencapsulated in a chitosan matrix using the spray-drying technique and the resulting system was investigated. High amounts of rutin were efficiently entrapped within polymeric microspheres, and these microparticles were characterized by a smooth surface and afforded a controlled release of the active compound. The anti-inflammatory activity of rutin-loaded microspheres was investigated in in vitro models of NCTC 2544 and C-28 cells treated with LPS by determining the levels of IL-1β and IL-6. The rutin-loaded microspheres showed an increase of in vitro anti-inflammatory activity with respect to the free active compound. Confocal laser scanning microscopy demonstrated that massive intracellular uptake of the chitosan microspheres took place after a few hours of incubation and that the drug was localized in the cytosol compartment of the treated cells. The improved anti-inflammatory activity of the rutin-loaded microspheres was further confirmed by an in vivo model of carrageenan-induced paw edema. PMID:27516307

  9. Effect of embolic microspheres in the treatment of primary hepatic carcinoma.

    PubMed

    Wang, K B; Sui, H; Li, W; Cui, L M; Bai, B

    2016-01-01

    The purpose of this study was to evaluate the clinical effect of embolic microspheres in the treatment of primary hepatic carcinoma. Fifty-eight patients who were confirmed with primary hepatic carcinoma by imaging were retrospectively analyzed. They were firstly perfused with 50 mg of oxaliplatin and 40 mg of epirubicin. Embolic microspheres were then injected into the distal end of targeted blood vessels. After this procedure, dynamic observation was carried out until tumor stain disappeared. Liver function and blood indexes were reexamined on days 5, 6, 7 and 28 after treatment, and moreover, the liver was examined with Magnetic Resonance Imaging (MRI) or computed tomography (CT). Compared to traditional lipiodol embolization, embolic microspheres did not aggregate the damage on liver function and the imaging examination suggested necrosis of some tumor tissues. Embolic microspheres proved to be effective in treating primary hepatic carcinoma. It produces no damage on liver function and can lead to significant shrinkage of hepatic carcinoma and necrosis of some tumor tissues. Embolic microspheres, which merely block distal branches of tumor-feeding artery, can avoid collateral circulation induced by permanent blocking, thus achieve a good treatment effect.

  10. Design of phosphated cross-linked microspheres of bael fruit gum as a biodegradable carrier.

    PubMed

    Mahammed, Nawaz; Gowda, D V; Deshpande, Rohan D; Thirumaleshwar, Shailesh

    2015-01-01

    Present work was aimed at designing of phosphated cross-linked microspheres of bael fruit gum (BFG) by emulsification method using sodium-tri-meta phosphate as a cross-linking agent for treatment of colon cancer using 5-fluorouracil as model drug. Stirring speed was found to be 1,000 rpm for about 5 h to be optimal to obtain reproducible microspheres. It was found that there is an increase in particle size as polymer concentration is increased whereas a reduction in particle size was observed as there is increase in stirring speed. Cross-linked BFG microspheres were successfully prepared by emulsification method. Optimum surfactant concentration was found to be 2 % w/w. Scanning electron microscopy studies showed that the drug-loaded microspheres were non-aggregated and in spherical shape. Differential scanning calorimetry and Fourier transform infrared-spectroscopy studies showed that drug and excipients are compatible. Release studies showed that drug release was more profound in cecal medium induced with enzymes causing degradation of the cross linked BFG than that of the release showed in simulated intestinal fluid. Stability studies showed that there were no significant changes in the drug content and physical appearance of microspheres.

  11. Pharmacokinetics, in vitro and in vivo correlation, and efficacy of exenatide microspheres in diabetic rats.

    PubMed

    Li, Xingang; Zhao, Zhigang; Li, Liang; Zhou, Tianyan; Lu, Wei

    2015-01-01

    Modeling and simulation are aimed at achieving information about the behaviors of the drugs without the actual measurements and determination. The purpose of this study was to characterize the in vivo behavior of exenatide microspheres using model-based methods. Exenatide is a glucagon-like peptide-1 agonist medication, belonging to the group of incretin mimetics, approved for the treatment of diabetes mellitus type 2. An oil-in-water solvent evaporation method was used to prepare the exenatide microspheres and their physicochemical features were investigated. After subcutaneous injection of exenatide microspheres to streptozotocin-induced diabetic rats, the exenatide concentrations increased and kept increasing and the blood glucose decreased in all diabetic rats. The in vivo release behavior of exenatide from microspheres was described by a transit compartment model. Based on the transit compartment model, the simulation method was proposed for the description of in vivo release. The in vitro and in vivo correlation (IVIVC) was established by the model-based simulation (R(2) = 0.903) and deconvolution (R(2) = 0.922) methods successfully. Using a transit compartment model to characterize the in vivo exenatide release from microspheres is an acceptable approach, and the IVIVC can be estimated reliably with the model-based simulation method.

  12. Design of phosphated cross-linked microspheres of bael fruit gum as a biodegradable carrier.

    PubMed

    Mahammed, Nawaz; Gowda, D V; Deshpande, Rohan D; Thirumaleshwar, Shailesh

    2015-01-01

    Present work was aimed at designing of phosphated cross-linked microspheres of bael fruit gum (BFG) by emulsification method using sodium-tri-meta phosphate as a cross-linking agent for treatment of colon cancer using 5-fluorouracil as model drug. Stirring speed was found to be 1,000 rpm for about 5 h to be optimal to obtain reproducible microspheres. It was found that there is an increase in particle size as polymer concentration is increased whereas a reduction in particle size was observed as there is increase in stirring speed. Cross-linked BFG microspheres were successfully prepared by emulsification method. Optimum surfactant concentration was found to be 2 % w/w. Scanning electron microscopy studies showed that the drug-loaded microspheres were non-aggregated and in spherical shape. Differential scanning calorimetry and Fourier transform infrared-spectroscopy studies showed that drug and excipients are compatible. Release studies showed that drug release was more profound in cecal medium induced with enzymes causing degradation of the cross linked BFG than that of the release showed in simulated intestinal fluid. Stability studies showed that there were no significant changes in the drug content and physical appearance of microspheres. PMID:24668152

  13. Electrorotation of titanium microspheres.

    PubMed

    Arcenegui, Juan J; Ramos, Antonio; García-Sánchez, Pablo; Morgan, Hywel

    2013-04-01

    Electrorotation (ROT) data for solid titanium micrometer-sized spheres in an electrolyte are presented for three different ionic conductivities, over the frequency range of 10 Hz to 100 kHz. The direction of rotation was found to be opposite to the direction of rotation of the electric field vector (counterfield electrorotation), with a single rotation peak. The maximum rotation rate occurs at a frequency of the order of the reciprocal RC time constant for charging the particle double layer capacitance through the resistor of the electrolyte bulk. A model for the electrical torque acting on a metallic sphere is presented, using a constant phase element impedance to describe the metal/electrolyte interface. The titanium spheres are much denser than the electrolyte and rest on the bottom substrate. Therefore, the electrical and viscous torques near a wall are considered in the analysis. Good agreement is found between the predicted and measured rotational speed as a function of frequency. Theory shows that there is no effect of induced charge electroosmotic flow on the ROT, as observed experimentally.

  14. Heritable Gastrointestinal Cancer Syndromes.

    PubMed

    Stoffel, Elena M

    2016-09-01

    Although almost all gastrointestinal cancers develop from sporadic genomic events, approximately 5% arise from germline mutations in genes associated with cancer predisposition. The number of these genes continues to increase. Tumor phenotypes and family history provide the framework for identifying at-risk individuals. The diagnosis of a hereditary cancer syndrome has implications for management of patients and their families. Systematic approaches that integrate family history and molecular characterization of tumors and polyps facilitate identification of individuals with this genetic predisposition. This article summarizes diagnosis and management of hereditary cancer syndromes associated with gastrointestinal cancers. PMID:27546846

  15. Microsphere-chain waveguides: Focusing and transport properties

    SciTech Connect

    Allen, Kenneth W. Astratov, Vasily N.; Darafsheh, Arash; Abolmaali, Farzaneh; Mojaverian, Neda; Limberopoulos, Nicholaos I.; Lupu, Anatole

    2014-07-14

    It is shown that the focusing properties of polystyrene microsphere-chain waveguides (MCWs) formed by sufficiently large spheres (D ≥ 20λ, where D is the sphere diameter and λ is the wavelength of light) scale with the sphere diameter as predicted by geometrical optics. However, this scaling behavior does not hold for mesoscale MCWs with D ≤ 10λ resulting in a periodical focusing with gradually reducing beam waists and in extremely small propagation losses. The observed effects are related to properties of nanojet-induced and periodically focused modes in such structures. The results can be used for developing focusing microprobes, laser scalpels, and polarization filters.

  16. Synthesis of sodium caseinate-calcium carbonate microspheres and their mineralization to bone-like apatite

    NASA Astrophysics Data System (ADS)

    Xu, Zhewu; Liang, Guobin; Jin, Lin; Wang, Zhenling; Xing, Chao; Jiange, Qing; Zhang, Zhiguang

    2014-06-01

    Phosphoproteins can induce and stabilize calcium carbonate (CaCO3) vaterite, which has desirable features for high reactivity. The purpose of this study was to synthesize bioactive CaCO3 microspheres for bone regeneration. Sodium caseinate (NaCas)-containing CaCO3 microspheres, with the crystal phase of vaterite, were synthesized by fast precipitation in an aqueous solution of CaCl2, Na2CO3, and 2 mg/mL of NaCas. The uniform microspheres exhibited rougher surfaces and lower negative charges than CaCO3 particles without NaCas addition. Fourier-transform infrared spectroscopy (FT-IR) of the microspheres showed characteristic peaks or bands corresponding to phosphate and hydroxyl groups. Thermogravimetric analysis (TGA) curves exhibited approximately 5% weight loss below 600 °C due to the decomposition of NaCas. Scanning electron microscope (SEM) images showed lath-like hydroxyapatite (HAp) on the surface after soaking in simulated body fluid (SBF) at 37 °C for 5 and 10 days. Energy dispersive X-ray spectrometry (EDS) revealed that the agglomerates were composed of Ca, C, O, P, Na, and Mg elements, and the Ca/P ratios ranged from 1.53 to 1.56. X-ray diffraction (XRD) patterns exhibited peaks characteristic of hydroxyapatite. The results of this study demonstrated that the addition of NaCas induced the formation of vaterite microspheres which possesses an enhanced apatite formation after soaking in SBF at 37 °C for 5 and 10 days. These NaCas-CaCO3 microspheres may be a potential biomaterial for bone regeneration.

  17. Holmium-lipiodol-alginate microspheres for fluoroscopy-guided embolotherapy and multimodality imaging.

    PubMed

    Oerlemans, Chris; Seevinck, Peter R; Smits, Maarten L; Hennink, Wim E; Bakker, Chris J G; van den Bosch, Maurice A A J; Nijsen, J Frank W

    2015-03-30

    Embolotherapy is a minimally invasive transcatheter technique aiming at reduction or complete obstruction of the blood flow by infusion of micro-sized particles in order to induce tumor regression. A major drawback of the current commercially available and clinically used microspheres is that they cannot be detected in vivo with medical imaging techniques, impeding intra- and post-procedural feedback. It can be expected that real-time monitoring of microsphere infusion and post-procedural imaging will result in better predictability and higher efficacy of the treatment. In this study, a novel microsphere formulation has been developed that can be visualized with fluoroscopy, X-ray computed tomography (CT) and magnetic resonance imaging (MRI). The microspheres were prepared with the JetCutter technique and consist of alginate (matrix-forming polymer), holmium (cross-linking and MRI contrast agent), lipiodol (radiopaque contrast agent) and Pluronic F-68 (surfactant). The mean size (±SEM) of the hydrated holmium-lipiodol-alginate microspheres (Ho-lip-ams) was 570±12 μm with a holmium content of 0.38±0.01% (w/w). Stability studies showed that the microspheres remained intact during incubation for two weeks in fetal calf serum (FCS) at 37 °C. The inclusion of lipiodol in the microspheres rendered excellent visualization capabilities for fluoroscopy and CT, whereas the holmium ions, which keep the alginate network together, also allow MR imaging. In this study it was shown that single sphere detection was possible by fluoroscopy, CT and MRI. The Ho-lip-ams were visualized in real-time, during infusion in a porcine kidney using fluoroscopy, and post-procedural, the deposition of the microspheres was examined with fluoroscopy, (cone beam rotational) CT and MRI. The different imaging modalities showed similar deposition patterns of the microspheres within the organ. The combination of intra-procedural visualization, multimodality imaging for patient follow-up and the

  18. Organic aerogel microspheres and fabrication method therefor

    DOEpatents

    Mayer, S.T.; Kong, F.M.; Pekala, R.W.; Kaschmitter, J.L.

    1996-04-16

    Organic aerogel microspheres which can be used in capacitors, batteries, thermal insulation, adsorption/filtration media, and chromatographic packings, having diameters ranging from about 1 micron to about 3 mm. The microspheres can be pyrolyzed to form carbon aerogel microspheres. This method involves stirring the aqueous organic phase in mineral oil at elevated temperature until the dispersed organic phase polymerizes and forms nonsticky gel spheres. The size of the microspheres depends on the collision rate of the liquid droplets and the reaction rate of the monomers from which the aqueous solution is formed. The collision rate is governed by the volume ratio of the aqueous solution to the mineral oil and the shear rate, while the reaction rate is governed by the chemical formulation and the curing temperature.

  19. Organic aerogel microspheres and fabrication method therefor

    DOEpatents

    Mayer, Steven T.; Kong, Fung-Ming; Pekala, Richard W.; Kaschmitter, James L.

    1996-01-01

    Organic aerogel microspheres which can be used in capacitors, batteries, thermal insulation, adsorption/filtration media, and chromatographic packings, having diameters ranging from about 1 micron to about 3 mm. The microspheres can be pyrolyzed to form carbon aerogel microspheres. This method involves stirring the aqueous organic phase in mineral oil at elevated temperature until the dispersed organic phase polymerizes and forms nonsticky gel spheres. The size of the microspheres depends on the collision rate of the liquid droplets and the reaction rate of the monomers from which the aqueous solution is formed. The collision rate is governed by the volume ratio of the aqueous solution to the mineral oil and the shear rate, while the reaction rate is governed by the chemical formulation and the curing temperature.

  20. What Are Gastrointestinal Stromal Tumors?

    MedlinePlus

    ... the digestive system. The gastrointestinal system The gastrointestinal (GI) system (or digestive system) processes food for energy ... bloodstream. This is the longest section of the GI tract, measuring more than 20 feet. The small ...

  1. Carboxymethyl starch/alginate microspheres containing diamine oxidase for intestinal targeting

    PubMed Central

    Blemur, Lindsay; Le, Tien Canh; Marcocci, Lucia; Pietrangeli, Paola

    2015-01-01

    Abstract The association of carboxymethyl starch (CMS) and alginate is proposed as a novel matrix for the entrapment of bioactive agents in microspheres affording their protection against gastrointestinal degradation. In this study, the enzyme diamine oxidase (DAO) from white pea (Lathyrus sativus) was immobilized by inclusion in microspheres formed by ionotropic gelation of CMS/alginate by complexation with Ca2+. The association of CMS to alginate generated a more compact structure presenting a lesser porosity, thus decreasing the access of gastric fluid inside the microspheres and preventing the loss of entrapped enzyme. Moreover, the immobilized enzyme remained active and was able to oxidize the polyamine substrates even in the presence of degrading proteases of pancreatin. The inclusion yield in terms of entrapped protein was of about 82%–95%. The DAO entrapped in calcium CMS/alginate beads retained up to 70% of its initial activity in simulated gastric fluid (pH 2.0). In simulated intestinal fluid (pH 7.2) with pancreatin, an overall retention of 65% of activity for the immobilized DAO was observed over 24 H, whereas in similar conditions the free enzyme was totally inactivated. Our project proposes the vegetal DAO as an antihistaminic agent orally administered to treat food histaminosis and colon inflammation. PMID:25779356

  2. Method for introduction of gases into microspheres

    DOEpatents

    Hendricks, Charles D.; Koo, Jackson C.; Rosencwaig, Allan

    1981-01-01

    A method for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500.mu. with both thin walls (0.5 to 4.mu.) and thick walls (5 to 20.mu.) that contain various fill gases, such as Ar, Kr, Xe, Br, DT, H.sub.2, D.sub.2, He, N.sub.2, Ne, CO.sub.2, etc. in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace. Almost any gas can be introduced into the inner cavity of a glass microsphere by this method during the formation of the microsphere provided that the gas is diffused into the gel membrane or microsphere prior to its transformation into glass. The process of this invention provides a significant savings of time and related expense of filling glass microspheres with various gases. For example, the time for filling a glass microballoon with 1 atmosphere of DT is reduced from about two hours to a few seconds.

  3. Hydrogen transport and storage in engineered microspheres

    SciTech Connect

    Rambach, G.; Hendricks, C.

    1996-10-01

    This project is a collaboration between Lawrence Livermore National Laboratory (LLNL) and W.J. Schafer Associates (WJSA). The authors plan to experimentally verify the performance characteristics of engineered glass microspheres that are relevant to the storage and transport of hydrogen for energy applications. They will identify the specific advantages of hydrogen transport by microspheres, analyze the infrastructure implications and requirements, and experimentally measure their performance characteristics in realistic, bulk storage situations.

  4. Pediatric functional gastrointestinal disorders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional gastrointestinal disorders continue to be a prevalent set of conditions faced by the healthcare team and have a significant emotional and economic impact. In this review, the authors highlight some of the common functional disorders seen in pediatric patients (functional dyspepsia, irrita...

  5. Gastrointestinal Bleeding in Athletes.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1989-01-01

    Describes the scope and importance of gastrointestinal bleeding in runners and other athletes, discussing causes, sites, and implications of exercise-related bleeding. Practical tips to mitigate the problem, potentially more troublesome in women because of lower iron stores, are presented (e.g., gradual conditioning and avoidance of prerace…

  6. Gastrointestinal endoscopy in pregnancy.

    PubMed

    Savas, Nurten

    2014-11-01

    Gastrointestinal endoscopy has a major diagnostic and therapeutic role in most gastrointestinal disorders; however, limited information is available about clinical efficacy and safety in pregnant patients. The major risks of endoscopy during pregnancy include potential harm to the fetus because of hypoxia, premature labor, trauma and teratogenesis. In some cases, endoscopic procedures may be postponed until after delivery. When emergency or urgent indications are present, endoscopic procedures may be considered with some precautions. United States Food and Drug Administration category B drugs may be used in low doses. Endoscopic procedures during pregnancy may include upper gastrointestinal endoscopy, percutaneous endoscopic gastrostomy, sigmoidoscopy, colonoscopy, enteroscopy of the small bowel or video capsule endoscopy, endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography. All gastrointestinal endoscopic procedures in pregnant patients should be performed in hospitals by expert endoscopists and an obstetrician should be informed about all endoscopic procedures. The endoscopy and flexible sigmoidoscopy may be safe for the fetus and pregnant patient, and may be performed during pregnancy when strong indications are present. Colonoscopy for pregnant patients may be considered for strong indications during the second trimester. Although therapeutic endoscopic retrograde cholangiopancreatography may be considered during pregnancy, this procedure should be performed only for strong indications and attempts should be made to minimize radiation exposure.

  7. [Gastrointestinal and hepatic diseases].

    PubMed

    Moctezuma-Velázquez, Carlos; Aguirre-Valadez, Jonathan

    2016-09-01

    Diet is considered an important triggering factor for gastrointestinal symptoms whose physiopathology includes not only measurable, inflammatory reactions, but also functional disorders, where no organic effects may be measured or demonstrated. Moreover, the prevalence of the perceived intolerance to certain foods ranges from 20-25% (within the general population) to 50-70% in diseases like irritable bowel syndrome. This intolerance has been observed particularly after the consumption of milk and dairy products, which are frequently considered as causative of gastrointestinal symptoms, thus limiting their ingestion. However, this behavior reduces the dietary sources of calcium and consequently may lead to malnutrition and bone decalcification, amongst other complications. The true dairy intolerance (intestinal lactase deficiency) explains most of the symptoms ensuing their consumption, but the frequency of such alteration on the different gastrointestinal diseases has not been determined. This review focuses on the most frequent gastrointestinal diseases and the existing evidence regarding the alterations and symptoms related to the consumption of milk or dairy products. PMID:27603892

  8. Apollo gastrointestinal analysis

    NASA Technical Reports Server (NTRS)

    Nichols, B. L.; Huang, C. T. L.

    1975-01-01

    Fecal bile acid patterns for the Apollo 17 flight were studied to determine the cause of diarrhea on the mission. The fecal sterol analysis gave no indication of an infectious diarrhea, or specific, or nonspecific etiology occurring during the entire flight. It is assumed that the gastrointestinal problems encountered are the consequences of altered physiology, perhaps secondary to physical or emotional stress of flight.

  9. Gastrointestinal endoscopy in pregnancy

    PubMed Central

    Savas, Nurten

    2014-01-01

    Gastrointestinal endoscopy has a major diagnostic and therapeutic role in most gastrointestinal disorders; however, limited information is available about clinical efficacy and safety in pregnant patients. The major risks of endoscopy during pregnancy include potential harm to the fetus because of hypoxia, premature labor, trauma and teratogenesis. In some cases, endoscopic procedures may be postponed until after delivery. When emergency or urgent indications are present, endoscopic procedures may be considered with some precautions. United States Food and Drug Administration category B drugs may be used in low doses. Endoscopic procedures during pregnancy may include upper gastrointestinal endoscopy, percutaneous endoscopic gastrostomy, sigmoidoscopy, colonoscopy, enteroscopy of the small bowel or video capsule endoscopy, endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography. All gastrointestinal endoscopic procedures in pregnant patients should be performed in hospitals by expert endoscopists and an obstetrician should be informed about all endoscopic procedures. The endoscopy and flexible sigmoidoscopy may be safe for the fetus and pregnant patient, and may be performed during pregnancy when strong indications are present. Colonoscopy for pregnant patients may be considered for strong indications during the second trimester. Although therapeutic endoscopic retrograde cholangiopancreatography may be considered during pregnancy, this procedure should be performed only for strong indications and attempts should be made to minimize radiation exposure. PMID:25386072

  10. Coacervate microspheres as carriers of recombinant adenoviruses.

    PubMed

    Kalyanasundaram, S; Feinstein, S; Nicholson, J P; Leong, K W; Garver, R I

    1999-01-01

    The therapeutic utility of recombinant adenoviruses (rAds) is limited in part by difficulties in directing the viruses to specific sites and by the requirement for bolus administration, both of which limit the efficiency of target tissue infection. As a first step toward overcoming these limitations, rAds were encapsulated in coacervate microspheres comprised of gelatin and alginate followed by stabilization with calcium ions. Ultrastructural evaluation showed that the microspheres formed in this manner were 0.8-10 microM in diameter, with viruses evenly distributed. The microspheres achieved a sustained release of adenovirus with a nominal loss of bioactivity. The pattern of release and the total amount of virus released was modified by changes in microsphere formulation. Administration of the adenovirus-containing microspheres to human tumor nodules engrafted in mice showed that the viral transgene was transferred to the tumor cells. It is concluded that coacervate microspheres can be used to encapsulate bioactive rAd and release it in a time-dependent manner.

  11. Demonstration of Microsphere Insulation in Cryogenic Vessels

    NASA Astrophysics Data System (ADS)

    Baumgartner, R. G.; Myers, E. A.; Fesmire, J. E.; Morris, D. L.; Sokalski, E. R.

    2006-04-01

    While microspheres have been recognized as a legitimate insulation material for decades, actual use in full-scale cryogenic storage tanks has not been demonstrated until now. The performance and life-cycle-cost advantages previously predicted have now been proven. Most bulk cryogenic storage tanks are insulated with either multilayer insulation (MLI) or perlite. Microsphere insulation, consisting of hollow glass bubbles, combines in a single material the desirable properties that other insulations only have individually. The material has high crush strength, low density, is noncombustible, and performs well in soft vacuum. These properties were proven during recent field testing of two 22,700-L (6,000-gallon) liquid nitrogen tanks, one insulated with microsphere insulation and the other with perlite. Normal evaporation rates (NER) for both tanks were monitored with precision test equipment and insulation levels within the tanks were observed through view ports as an indication of insulation compaction. Specific industrial applications were evaluated based on the test results and beneficial properties of microsphere insulation. Over-the-road trailers previously insulated with perlite will benefit not only from the reduced heat leak, but also the reduced mass of microsphere insulation. Economic assessments for microsphere-insulated cryogenic vessels including life-cycle cost are also presented.

  12. Simultaneous nano- and micro-scale control of nanofibrous microspheres self-assembled from star-shaped polymers

    PubMed Central

    Zhang, Zhanpeng; Marson, Ryan L.; Ge, Zhishen; Glotzer, Sharon C.; Ma, Peter X.

    2015-01-01

    The mechanism underlying the multi-scale self-assembly of star-shaped polymers into non-hollow, hollow, and spongy nanofibrous microspheres is reported. Star-shaped poly(L-lactic acid) polymers with varying arm-numbers and arm-lengths are synthesized, dissolved in tetrahydrofuran, emulsified in glycerol, and thermally-induced to phase separate, resulting in microspheres that are either smooth or fibrous on the nano-scale, and either non-hollow, hollow, or spongy on the micro-scale. Molecular architecture and the hydroxyl density are shown to control assembly and morphology at both nano- and micro-scales. Nanofibers form only when the arm length is sufficiently long, while an increase in hydroxyl density causes the microspheres to change from non-hollow to hollow to spongy. We demonstrate via both experiments of capping or doubling the hydroxyl end groups and dissipative particle dynamics simulations that the affinity of hydroxyl to glycerol is critical to stabilizing the micro-scale structure. A “phase diagram” was constructed for the six types of microspheres in relation to the molecular structures of the star-shaped polymers. The proposed mechanism explains how star-shaped polymers self-assemble into various microspheres, and guides us to simultaneously control both nano- and micro-features of the microspheres. PMID:26009995

  13. Haemochromatosis and gastrointestinal cancer.

    PubMed

    Lagergren, Katarina; Wahlin, Karl; Mattsson, Fredrik; Alderson, Derek; Lagergren, Jesper

    2016-10-15

    Iron overload in patients with haemochromatosis is a strong risk factor for liver cancer, but its influence on other gastrointestinal cancer risk is unclear. The aim was to assess the relative risk of luminal gastrointestinal cancer among patients diagnosed with haemochromatosis. This population-based, nationwide Swedish cohort study included patients with haemochromatosis in Sweden in 1965-2013. The incidence of gastrointestinal cancers was assessed through the Swedish Cancer Registry. The measure of relative risk was the standardised incidence ratio (SIR) with 95% confidence interval (CI), that is, the ratio of the observed number of gastrointestinal cancers in the haemochromatosis cohort divided by the expected number of such cancers, calculated from the entire corresponding background population of Sweden. Among 6,849 patients in the haemochromatosis cohort with up to 48 years of follow-up, the SIRs were 3-fold increased for oesophageal squamous cell carcinoma (SIR = 3.2, 95% CI 1.3-6.6; n = 7) and 40% increased for colon adenocarcinoma (SIR = 1.4, 95% CI 1.1-1.9; n = 54). No associations were found between haemochromatosis and the risk of adenocarcinoma of the oesophagus (SIR = 0.5, 95% CI 0.0-2.5; n = 1), stomach (SIR = 0.7, 95% CI 0.3-1.4; n = 8), small bowel (SIR = 1.2, 95% CI 0.0-6.7; n = 1) or rectum (SIR = 1.0, 95% CI 0.6-1.6; n = 21). These findings indicate that haemochromatosis increases the risk of oesophageal squamous cell carcinoma and colon adenocarcinoma, but might not influence the risk of other types of luminal gastrointestinal cancer. These findings should encourage further research examining the role of iron overload in cancer aetiology.

  14. Sustained-release G-CSF microspheres using a novel solid-in-oil-in-oil-in-water emulsion method

    PubMed Central

    Liu, Guang; Hong, Xiaoyun; Jiang, Mier; Yuan, Weien

    2012-01-01

    Background The main treatments for cancers are still chemotherapy and radiotherapy for intermediate-stage cancer and terminal cancer. However, the therapeutic methods often result in a decreased neutrophilic granulocyte count and other side effects. In this study, in order to improve the neutrophilic granulocyte levels in the blood after radiotherapy and chemotherapy, we developed a sustained-release granulocyte colony–stimulating factor (G-CSF) microsphere formulation using a novel solid-in-oil-in-oil-in-water (S/O/O/W) emulsification method. Methods G-CSF was loaded into dextran nanoparticles by freezing-induced phase separation, and then the G-CSF–loaded nanoparticles were encapsulated into sustained-release poly(lactic-co- glycolic acid) microspheres using S/O/O/W emulsification. The control microspheres were also prepared through W/O/W emulsification. The performance of the two microsphere formulations was investigated both in vitro and in vivo. Results The microspheres for the controlled release of G-CSF in a zero-order or near-zero-order pattern were provided for 2 weeks. The in vitro cumulative G-CSF release kept over 90% of its bioactivity, which was proved by a NFS-60 cell line growth assay. The microspheres of the control group fabricated by W/O/W emulsification maintained less then half of its bioactivity. The in vivo efficacy of microspheres made using the S/O/O/W method was higher than those using the W/O/W method. Conclusion These results suggested that the microspheres prepared by the S/O/O/W method had increased neutrophil activity compared to those prepared by W/O/W. PMID:22923993

  15. Curvature capillary migration of microspheres.

    PubMed

    Sharifi-Mood, Nima; Liu, Iris B; Stebe, Kathleen J

    2015-09-14

    We address the question: how does capillarity propel microspheres along curvature gradients? For a particle on a fluid interface, there are two conditions that can apply at the three phase contact line: either the contact line adopts an equilibrium contact angle, or it can be pinned by kinetic trapping, e.g. at chemical heterogeneities, asperities, or other pinning sites on the particle surface. We formulate the curvature capillary energy for both scenarios for particles smaller than the capillary length and far from any pinning boundaries. The scale and range of the distortion made by the particle are set by the particle radius; we use singular perturbation methods to find the distortions and to rigorously evaluate the associated capillary energies. For particles with equilibrium contact angles, contrary to the literature, we find that the capillary energy is negligible, with the first contribution bounded to fourth order in the product of the particle radius and the deviatoric curvature of the host interface. For pinned contact lines, we find curvature capillary energies that are finite, with a functional form investigated previously by us for disks and microcylinders on curved interfaces. In experiments, we show microspheres migrate along deterministic trajectories toward regions of maximum deviatoric curvature with curvature capillary energies ranging from 6 × 10(3)-5 × 10(4)kBT. These data agree with the curvature capillary energy for the case of pinned contact lines. The underlying physics of this migration is a coupling of the interface deviatoric curvature with the quadrupolar mode of nanometric disturbances in the interface owing to the particle's contact line undulations. This work is an example of the major implications of nanometric roughness and contact line pinning for colloidal dynamics.

  16. Pulmonary-impedance power spectral analysis: A facile means of detecting radiation-induced gastrointestinal distress and performance decrement in man

    NASA Technical Reports Server (NTRS)

    Rick, R. C.; Lushbaugh, C. C.; Mcdow, E.; Frome, E.

    1972-01-01

    Changes in respiratory variance revealed by power spectral analysis of the pulmonary impedance pneumogram can be used to detect and measure stresses directly or indirectly affecting human respiratory function. When gastrointestinal distress occurred during a series of 5 total-body exposures of 30 R at a rate of 1.5 R/min, it was accompanied by typical shifts in pulmonary impedance power spectra. These changes did not occur after protracted exposure of 250 R (30 R daily) at 1.5 R/hr that failed to cause radiation sickness. This system for quantitating respiratory effort can also be used to detect alterations in one's ability to perform under controlled exercise conditions.

  17. Gastrointestinal Degradation of Fumonisin B₁ by Carboxylesterase FumD Prevents Fumonisin Induced Alteration of Sphingolipid Metabolism in Turkey and Swine.

    PubMed

    Masching, Sabine; Naehrer, Karin; Schwartz-Zimmermann, Heidi-Elisabeth; Sărăndan, Mihai; Schaumberger, Simone; Dohnal, Ilse; Nagl, Veronika; Schatzmayr, Dian

    2016-03-21

    The mycotoxin fumonisin B₁ (FB₁) is a frequent contaminant of feed and causes various adverse health effects in domestic animals. Hence, effective strategies are needed to prevent the impact of fumonisins on livestock productivity. Here we evaluated the capability of the fumonisin carboxylesterase FumD to degrade FB₁ to its less toxic metabolite hydrolyzed FB₁ (HFB₁) in the gastrointestinal tract of turkeys and pigs. First, an ex vivo pig model was used to examine the activity of FumD under digestive conditions. Within 2 h of incubation with FumD, FB₁ was completely degraded to HFB₁ in the duodenum and jejunum, respectively. To test the efficacy of the commercial application of FumD (FUMzyme) in vivo, female turkeys (n = 5) received either basal feed (CON), fumonisin-contaminated feed (15 mg/kg FB₁+FB₂; FB) or fumonisin-contaminated feed supplemented with FUMzyme (15 U/kg; FB+FUMzyme) for 14 days ad libitum. Addition of FUMzyme resulted in significantly decreased levels of FB₁ in excreta, whereas HFB₁ concentrations were significantly increased. Compared to the FB group (0.24 ± 0.02), the mean serum sphinganine-to-sphingosine (Sa/So) ratio was significantly reduced in the FB+FUMzyme group (0.19 ± 0.02), thus resembling values of the CON group (0.16 ± 0.02). Similarly, exposure of piglets (n = 10) to 2 mg/kg FB₁+FB₂ for 42 days caused significantly elevated serum Sa/So ratios (0.39 ± 0.15) compared to the CON group (0.14 ± 0.01). Supplementation with FUMzyme (60 U/kg) resulted in gastrointestinal degradation of FB₁ and unaffected Sa/So ratios (0.16 ± 0.02). Thus, the carboxylesterase FumD represents an effective strategy to detoxify FB₁ in the digestive tract of turkeys and pigs.

  18. Microsphere size, precipitation kinetics and drug distribution control drug release from biodegradable polyanhydride microspheres.

    PubMed

    Berkland, Cory; Kipper, Matt J; Narasimhan, Balaji; Kim, Kyekyoon Kevin; Pack, Daniel W

    2004-01-01

    A thorough understanding of the factors affecting drug release mechanisms from surface-erodible polymer devices is critical to the design of optimal delivery systems. Poly(sebacic anhydride) (PSA) microspheres were loaded with three model drug compounds (rhodamine B, p-nitroaniline and piroxicam) with a range of polarities (water solubilities). The drug release profiles from monodisperse particles of three different sizes were compared to release from polydisperse microspheres. Each of the model drugs exhibited different release mechanisms. Drug distribution within the polymer was investigated by laser scanning confocal microscopy and scanning electron microscopy. Rhodamine, the most hydrophilic compound investigated, was localized strongly toward the microsphere surface, while the much more hydrophobic compound, piroxicam, distributed more evenly. Furthermore, all three compounds were most uniformly distributed in the smallest microspheres, most likely due to the competing effects of drug diffusion out of the nascent polymer droplets and the precipitation of polymer upon solvent extraction, which effectively "traps" the drug in the polymer matrix. The differing drug distributions were manifested in the drug release profiles. Rhodamine was released very quickly independent of microsphere size. Thus, extended release profiles may not be obtainable if the drug strongly redistributes in the microspheres. The release of p-nitroaniline was more prolonged, but still showed little dependence on microsphere size. Hence, when water-soluble drugs are encapsulated with hydrophobic polymers, it may be difficult to tailor release profiles by controlling microsphere size. The piroxicam-loaded microspheres exhibit the most interesting release profiles, showing that release duration can be increased by decreasing microsphere size, resulting in a more uniform drug distribution. PMID:14684277

  19. [Zinc and gastrointestinal disorders].

    PubMed

    Higashimura, Yasuki; Takagi, Tomohisa; Naito, Yuji

    2016-07-01

    Zinc, an essential trace element, affects immune responses, skin metabolism, hormone composition, and some sensory function, so that the deficiency presents various symptoms such as immunodeficiency and taste obstacle. Further, the zinc deficiency also considers as a risk of various diseases. Recent reports demonstrated that -20% of the Japanese population was marginally zinc deficiency, and over 25% of the global population is at high risk of zinc deficiency. In gastrointestinal disorders, zinc plays an important role in the healing of mucosal and epithelial damage. In fact, polaprezinc, a chelate compound of zinc and L-carnosine, has been used for the treatment of gastric ulcer and gastritis. We describe here the therapeutic effect of zinc on gastrointestinal disorders. PMID:27455800

  20. [Microbiota and gastrointestinal diseases].

    PubMed

    Polanco Allué, I

    2015-12-01

    The bacterial colonisation is established immediately after birth, through direct contact with maternal microbiota, and may be influenced during lactation. There is emerging evidence indicating that quantitative and qualitative changes on gut microbiota contribute to alterations in the mucosal activation of the immune system, leading to intra- or extra-intestinal diseases. A balance between pathogenic and beneficial microbiota throughout childhood and adolescence is important to gastrointestinal health, including protection against pathogens, inhibition of pathogens, nutrient processing (synthesis of vitamin K), stimulation of angiogenesis, and regulation of host fat storage. Probiotics can promote an intentional modulation of intestinal microbiota favouring the health of the host. A review is presented on the modulation of intestinal microbiota on prevention, and adjuvant treatment of some paediatric gastrointestinal diseases. PMID:26534880

  1. Gastrointestinal stromal tumor

    PubMed Central

    Yue, Changjun

    2012-01-01

    Gastrointestinal stromal tumor has received a lot of attention over the last 10 years due to its unique biologic behavior, clinicopathological features, molecular mechanisms, and treatment implications. GIST is the most common mesenchymal neoplasm in the gastrointestinal tract and has emerged from a poorly understood and treatment resistant neoplasm to a well-defined tumor entity since the discovery of particular molecular abnormalities, KIT and PDGFRA gene mutations. The understanding of GIST biology at the molecular level promised the development of novel treatment modalities. Diagnosis of GIST depends on the integrity of histology, immunohistochemistry and molecular analysis. The risk assessment of the tumor behavior relies heavily on pathological evaluation and significantly impacts clinical management. In this review, historic review, epidemiology, pathogenesis and genetics, diagnosis, role of molecular analysis, prognostic factor and treatment strategies have been discussed. PMID:22943011

  2. NSAIDS and gastrointestinal cancer.

    PubMed

    Piazuelo, Elena; Lanas, Angel

    2015-07-01

    A large body of evidence from epidemiological and preclinical studies have shown that nonsteroideal anti-inflammatory drugs (NSAIDs) have a chemopreventive effect on gastrointestinal cancers and, more specifically, in colorectal cancer. This review highlights recent advances in our understanding of the role of NSAIDs in colorectal cancer prevention and adjuvant treatment. Moreover, we have focused on randomized controlled studies assessing their efficacy to prevent adenoma recurrence and reduction of colorectal cancer incidence and mortality but also their gastrointestinal and cardiovascular side effects. Among NSAIDs, almost the unique agent with potential use as chemopreventive agent is aspirin at low dose since it has both no cardiovascular and low gastrointestinal risk. Furthermore, since aspirin has shown efficacy in secondary prevention of cardiovascular diseases, this drug carries a particular attractive intervention for selected populations. Nevertheless, before it can be prescribed, further studies are necessary to define some important questions, specially the most appropriate dose and time of aspirin use and the population who may benefit from it. PMID:26093284

  3. Gastrointestinal Degradation of Fumonisin B1 by Carboxylesterase FumD Prevents Fumonisin Induced Alteration of Sphingolipid Metabolism in Turkey and Swine

    PubMed Central

    Masching, Sabine; Naehrer, Karin; Schwartz-Zimmermann, Heidi-Elisabeth; Sărăndan, Mihai; Schaumberger, Simone; Dohnal, Ilse; Nagl, Veronika; Schatzmayr, Dian

    2016-01-01

    The mycotoxin fumonisin B1 (FB1) is a frequent contaminant of feed and causes various adverse health effects in domestic animals. Hence, effective strategies are needed to prevent the impact of fumonisins on livestock productivity. Here we evaluated the capability of the fumonisin carboxylesterase FumD to degrade FB1 to its less toxic metabolite hydrolyzed FB1 (HFB1) in the gastrointestinal tract of turkeys and pigs. First, an ex vivo pig model was used to examine the activity of FumD under digestive conditions. Within 2 h of incubation with FumD, FB1 was completely degraded to HFB1 in the duodenum and jejunum, respectively. To test the efficacy of the commercial application of FumD (FUMzyme) in vivo, female turkeys (n = 5) received either basal feed (CON), fumonisin-contaminated feed (15 mg/kg FB1+FB2; FB) or fumonisin-contaminated feed supplemented with FUMzyme (15 U/kg; FB+FUMzyme) for 14 days ad libitum. Addition of FUMzyme resulted in significantly decreased levels of FB1 in excreta, whereas HFB1 concentrations were significantly increased. Compared to the FB group (0.24 ± 0.02), the mean serum sphinganine-to-sphingosine (Sa/So) ratio was significantly reduced in the FB+FUMzyme group (0.19 ± 0.02), thus resembling values of the CON group (0.16 ± 0.02). Similarly, exposure of piglets (n = 10) to 2 mg/kg FB1+FB2 for 42 days caused significantly elevated serum Sa/So ratios (0.39 ± 0.15) compared to the CON group (0.14 ± 0.01). Supplementation with FUMzyme (60 U/kg) resulted in gastrointestinal degradation of FB1 and unaffected Sa/So ratios (0.16 ± 0.02). Thus, the carboxylesterase FumD represents an effective strategy to detoxify FB1 in the digestive tract of turkeys and pigs. PMID:27007395

  4. Dosimetry of in situ activated dysprosium microspheres.

    PubMed

    Adnani, N

    2004-03-01

    This paper presents the results of a study aimed at investigating the dosimetry of stable dysprosium microspheres activated, in situ, by a linac generated photon beam. In phantom measurements of the neutron flux within an 18 MV photon beam were performed using CR-39 detectors and gold activation. The results were used in conjunction with a Monte Carlo computer simulation to investigate the dose distribution resulting from the activation of dysprosium (Dy) microspheres using an 18 MV photon beam. Different depths, lesion volumes and volume concentrations of microspheres are investigated. The linac lower collimator jaws are assumed completely closed to shield the tumour volume from the photon dose. Using a single AP field with 0 x 0 cm2 field size (closed jaws), a photon dose rate of 600 MU min(-1) and 80 cm SSD for 10 min, an average dose exceeding 1 Gy can be delivered to spherical lesions of 0.5 cm and higher diameter. The variation of the average dose with the size of the lesion reaches saturation for tumour volumes exceeding 1 cm in diameter. This report shows that the photon beam of a high-energy linac can be used to activate Dy microspheres in situ and, as a result, deliver a significant dose of beta radiation. Non-radioactive Dy microspheres do not have the toxicity and imaging problems associated with commercially available yttrium-90 based products. PMID:15070199

  5. A facile synthesis of luminescent YVO4:Eu3+ hollow microspheres in virtue of template function of the SDS-PEG soft clusters

    NASA Astrophysics Data System (ADS)

    Wang, Juan; Yan, Yinglin; Hojamberdiev, Mirabbos; Ruan, Xiaoguang; Cai, Anjiang; Xu, Yunhua

    2012-08-01

    Hollow europium-doped yttrium orthovanadate (YVO4:Eu3+) microspheres were fabricated via a sodium dodecyl sulfate (SDS)-polyethylene glycol (PEG)-assisted hydrothermal technique. The as-synthesized hollow YVO4:Eu3+ microspheres were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). The obtained results showed that the morphology and size of the hollow microspheres have a strong dependence on the hydrothermal reaction time of the YVO4:Eu3+ powders. It is believed that the SDS-PEG clusters perform a function of dual soft-template that results in a unique template-induced secondary assembly in the one-pot synthesis of hollow YVO4:Eu3+ microspheres. The photoluminescence measurement revealed that the YVO4:Eu3+ powders with a spherical hollow shape have better red luminescence compared to the YVO4:Eu3+ solid microspheres. As a result, the controlled synthesis of hollow YVO4:Eu3+ microspheres not only has a great theoretical significance in studying the three-dimensional control and selective synthesis of inorganic materials but also benefits the potential applications based on hollow YVO4:Eu3+ microspheres owing to reducing the usage of expensive rare-earth elements.

  6. Characterization and evaluation of triamcinolone, raloxifene, and their dual-loaded microspheres as prospective local treatment system in rheumatic rat joints.

    PubMed

    Ocal, Yigit; Kurum, Baris; Karahan, Siyami; Tezcaner, Aysen; Ozen, Seza; Keskin, Dilek

    2014-08-01

    In this study, injectable microspheres were developed for the local treatment of joint degeneration in rheumatoid arthritis (RA). Microspheres loaded with triamcinolone (TA), a corticosteroid drug, and/or raloxifene (Ral), a cartilage regenerative drug, were prepared with a biodegradable and biocompatible polymer, polycaprolactone (PCL). Microspheres were optimized for particle size, structural properties, drug release, and loading properties. In vitro release of Ral was very slow because of the low solubility of the drug and hydrophobic nature of PCL. However, when coloaded with TA, both drugs were released at higher amounts compared with their single forms. Smallest particle sizes were obtained in dual drug-loaded microspheres. In vitro cytotoxicity tests showed biocompatibility of microspheres. In vivo bioefficacy of these microspheres was also examined in adjuvant-induced arthritis model in rats. In vivo histological studies of control groups showed development of RA with high median lesion score (5.0). Compared with control and intra-articular free drug injections, microsphere treatment groups showed lower lesion scores and better healing outcomes in histological evaluations. Results suggest that a controlled delivery system of TA and RAL by a single injection in inflamed joints holds promise for healing and suppressing inflammation.

  7. Food-associated stimuli enhance barrier properties of gastrointestinal mucus.

    PubMed

    Yildiz, Hasan M; Speciner, Lauren; Ozdemir, Cafer; Cohen, David E; Carrier, Rebecca L

    2015-06-01

    Orally delivered drugs and nutrients must diffuse through mucus to enter the circulatory system, but the barrier properties of mucus and their modulation by physiological factors are generally poorly characterized. The main objective of this study was to examine the impact of physicochemical changes occurring upon food ingestion on gastrointestinal (GI) mucus barrier properties. Lipids representative of postprandial intestinal contents enhanced mucus barriers, as indicated by a 10-142-fold reduction in the transport rate of 200 nm microspheres through mucus, depending on surface chemistry. Physiologically relevant increases in [Ca(2+)] resulted in a 2-4-fold reduction of transport rates, likely due to enhanced cross-linking of the mucus gel network. Reduction of pH from 6.5 to 3.5 also affected mucus viscoelasticity, reducing particle transport rates approximately 5-10-fold. Macroscopic visual observation and micro-scale lectin staining revealed mucus gel structural changes, including clumping into regions into which particles did not penetrate. Histological examination indicated food ingestion can prevent microsphere contact with and endocytosis by intestinal epithelium. Taken together, these results demonstrate that GI mucus barriers are significantly altered by stimuli associated with eating and potentially dosing of lipid-based delivery systems; these stimuli represent broadly relevant variables to consider upon designing oral therapies. PMID:25907034

  8. Imatinib-induced hyperbilirubinemia with UGT1A1 (*28) promoter polymorphism: first case series in patients with gastrointestinal stromal tumor

    PubMed Central

    Saif, Muhammad Wasif; Smith, Melissa Hennessey; Maloney, Antonia; Diasio, Robert B.

    2016-01-01

    Imatinib, an orally administered protein-tyrosine kinase inhibitor (TKI) is indicated for the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumor (GIST). Severe hepatotoxicity associated with imatinib is rare, and relationship to polymorphism of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) expression and related frequency of hyperbilirubinemia or toxicity are not well known. We present a case series patients who developed hyperbilirubinemia while on oral administration imatinib for treatment of GIST. Genetic testing for polymorphism of UGT1A1 showed the first patient to be homozygous for the UGT1A1 TA7 (*28) polymorphism and the second patient heterozygous for the UGT1A1 TA1 (*28) polymorphism. The first patient had to stop imatinib due to severe and persistent hyperbilirubenemia peaking >3 despite reducing imatininb to only 100 mg every other day while the second patient improved at this dose. Our case series represent the first data associating UGT1A1 polymorphism and imatinib in patients being treated for GIST. Given the prevalence of Gilbert’s syndrome and the increasing use of imatinib, we encourage physicians to be aware of this possible toxicity as hepatotoxicity can be fatal if not managed in a timely fashion. This association is also timely due to recent FDA requirement for testing UGT1A1 polymorphism for nilotinib, another TKI.

  9. Carboxymethyl starch mucoadhesive microspheres as gastroretentive dosage form.

    PubMed

    Lemieux, Marc; Gosselin, Patrick; Mateescu, Mircea Alexandru

    2015-12-30

    Carboxymethyl starch microspheres (CMS-MS) were produced from carboxymethyl starch powder (CMS-P) with a degree of substitution (DS) from 0.1 to 1.5 in order to investigate the influence of DS on physicochemical, drug release and mucoadhesion properties as well as interactions with gastrointestinal tract (GIT) epithelial barrier models. Placebo and furosemide loaded CMS-MS were obtained by emulsion-crosslinking with sodium trimetaphosphate (STMP). DS had an impact on increasing equilibrium water uptake and modulating drug release properties of the CMS-MS according to the surrounding pH. The transepithelial electrical resistance (TEER) of NCI-N87 gastric cell monolayers was not influenced in presence of CMS-MS, whereas that of Caco-2 intestinal cell monolayers decreased with increasing DS but recovered initial values at about 15h post-treatment. CMS-MS with increasing DS also enhanced furosemide permeability across both NCI-N87 and Caco-2 monolayers at pH gradients from 3.0 to 7.4. Mucoadhesion of CMS-MS on gastric mucosa (acidic condition) increased with the DS up to 55% for a DS of 1.0 but decreased on neutral intestinal mucosa to less than 10% with DS of 0.1. The drug release, permeability enhancement and mucoadhesive properties of the CMS-MS suggest CMS-MS with DS between 0.6 and 1.0 as suitable excipient for gastroretentive oral delivery dosage forms.

  10. Poly(2-hydroxyethyl methacrylate) microspheres/liquid poly(dimethylsiloxane) composition for correction of small defects in face: histological evaluation in animal experiment.

    PubMed

    Horák, D; Adamyan, A; Golubeva, O; Skuba, N; Vinokurova, T

    2006-02-01

    Two kinds of composition based on commercial liquid poly(dimethylsiloxane) and laboratory-made poly(2-hydroxyethyl methacrylate) (PHEMA) microspheres of different size fractions (30-40 or 125-180 microm) were prepared. Tissue reaction on injection of the compositions, optimum microsphere size and morphology were investigated in the experiments on rats. The microspheres induced foreign body reaction characterized by an increased content of fibroblasts and mild infiltration of injection field by inflammatory cells. The 125-180 microm microspheres seemed to be well covered with poly(dimethylsiloxane) and more uniformly distributed in the tissue than the 30-40 microm ones. As a result, the extent of foreign body reaction induced by the former microspheres was somewhat lower than that induced by the latter. Moreover, time-dependent degradation of 30-40 microm PHEMA microspheres was more pronounced than that of 125-180 microm ones, which can affect duration of the aesthetic effect after prospective facioplasty. Results of histological investigations demonstrate a good prospect of the proposed composition for contour and bulk facioplasty of small soft tissue defects and skin wrinkles.

  11. Localized drugs delivery hydroxyapatite microspheres for osteoporosis therapy

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Ko, I. H.; Jeon, S.-H.; Chae, J. H.; Lee, E. J.; Chang, J. H.

    2011-10-01

    This study describes the preparation of hydroxyapatite microspheres for local drugs delivery. The formation of the hydroxyapatite microspheres was initiated by enzymatic decomposition of urea and accomplished by emulsification process (water-in-oil). The microspheres obtained were sintered at 500°C. Scanning electron microscope (SEM) indicated that the microspheres have various porous with random size, which maximizes the surface area. Cytotoxicity was not observed after sintering. Osteoporosis drugs, alendronate and BMP-2, were loaded into HAp microspheres and the releases of both molecules showed sustained releasing profiles.

  12. Acrolein Microspheres Are Bonded To Large-Area Substrates

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan; Yen, Richard C. K.

    1988-01-01

    Reactive cross-linked microspheres produced under influence of ionizing radiation in aqueous solutions of unsaturated aldehydes, such as acrolein, with sodium dodecyl sulfate. Diameters of spheres depend on concentrations of ingredients. If polystyrene, polymethylmethacrylate, or polypropylene object immersed in solution during irradiation, microspheres become attached to surface. Resulting modified surface has grainy coating with reactivity similar to free microspheres. Aldehyde-substituted-functional microspheres react under mild conditions with number of organic reagents and with most proteins. Microsphere-coated macrospheres or films used to immobilize high concentrations of proteins, enzymes, hormones, viruses, cells, and large number of organic compounds. Applications include separation techniques, clinical diagnostic tests, catalytic processes, and battery separators.

  13. Biosensing by WGM Microspherical Resonators

    PubMed Central

    Righini, Giancarlo C.; Soria, Silvia

    2016-01-01

    Whispering gallery mode (WGM) microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed. PMID:27322282

  14. Biosensing by WGM Microspherical Resonators.

    PubMed

    Righini, Giancarlo C; Soria, Silvia

    2016-01-01

    Whispering gallery mode (WGM) microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 10⁸-10⁸ lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed. PMID:27322282

  15. Biosensing by WGM Microspherical Resonators.

    PubMed

    Righini, Giancarlo C; Soria, Silvia

    2016-06-17

    Whispering gallery mode (WGM) microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 10⁸-10⁸ lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed.

  16. Sonochemical proteinaceous microspheres for wound healing.

    PubMed

    Silva, Raquel; Ferreira, Helena; Vasconcelos, Andreia; Gomes, Andreia C; Cavaco-Paulo, Artur

    2012-01-01

    In this work, we report a novel approach using proteinaceous microspheres of bovine serum albumin (BSA), human serum albumin (HSA) and silk fibroin (SF) containing different organic solvents, namely n-dodecane, mineral oil and vegetable oil, to reduce the activity of human neutrophil elastase (HNE) found in high levels on chronic wounds. The ability of these devices to inhibit HNE was evaluated using porcine pancreatic elastase (PPE) solution as a model of wound exudates. The results obtained indicated that the level of PPE activity can be tuned by changing the organic solvent present on different protein microspheres, thus showing an innovative way of controlling the elastase-antielastase imbalance found in chronic wounds. Furthermore, these proteinaceous microspheres were shown to be important carriers of elastase inhibitors causing no cytotoxicity in human skin fibroblasts in vitro, making them suitable for biomedical applications, such as chronic wounds.

  17. Alternating current electrokinetic properties of gold-coated microspheres.

    PubMed

    García-Sánchez, Pablo; Ren, Yukun; Arcenegui, Juan J; Morgan, Hywel; Ramos, Antonio

    2012-10-01

    We present dielectrophoresis (DEP) and electrorotation (ROT) measurements of gold-coated polystyrene microspheres as a function of frequency and for several electrolyte conductivities. Particle rotation was counterfield with a maximum rotation rate observed at a single characteristic frequency. Negative DEP was observed for frequencies lower than this characteristic frequency and positive DEP for signal frequencies higher than this. These experimental observations are in agreement with predictions for the force and torque on the induced dipole of a perfectly polarizable metal sphere. We present a theoretical model for this case, and good agreement is found for both ROT and DEP measurements if we take into account the viscous friction for a spherical particle near a wall. From the characteristic frequency for rotation, we obtain the capacitance of the electrical double layer at the electrolyte-particle interface. Remarkably, no effect of induced charge electroosmosis around the particles can be inferred from DEP measurements.

  18. Redox-responsive alginate microsphere containing cystamine.

    PubMed

    Kwon, Kyeongnan; Kim, Jin-Chul

    2016-10-01

    Redox-responsive microspheres were prepared by solidifying the alginate- and cystamine-containing water droplets of O/W emulsion using calcium ion. Emulsions were prepared using alginate/cystamine mixture solution whose the carboxylic group/the amino group molar ratio was 1:1, 1:2, and 1:3, and whose the total concentration was kept to 2% (w/v). The microspheres on Scanning electron microscopy photographs were almost spherical and they were less than 1 μm in diameter. According to the energy-dispersive X-ray spectroscopy, the sulfur content of the microspheres was found to be 6.1, 11.4, and 14.8% (w/w), respectively, not markedly different from the calculated content. The release degree of blue dextran loaded in the microspheres was higher as the cystamine content was higher. Microspheres released almost the same amount of dye regardless of dithiothreitol (DTT, a reducing agent) concentration when the cystamine content was relatively low (e.g. 14.5% (w/w)), whereas they released dye in DTT concentration-dependent manner when the cystamine content was relatively high (e.g. 27.0 and 35.1% (w/w)). The light scattering intensity of alginate/cystamine mixture solution was stronger at a larger amount of cystamine, indicating that cystamine could cross-link alginate chains. The light scattering intensity decreased with increasing DTT concentration, possibly because of the breakdown of the disulfide bond of cystamine. The breakdown of the disulfide bond could account for why the DTT concentration-dependent release of dye loaded in the microspheres was observed. PMID:27484719

  19. Facile Formation of Dynamic Hydrogel Microspheres for Triggered Growth Factor Delivery

    PubMed Central

    King, William J.; Toepke, Michael W.; Murphy, William L.

    2010-01-01

    Dynamic hydrogels have emerged as an important class of biomaterials for temporal control over growth factor delivery. In this study we formed dynamic hydrogel microspheres from protein-polymer conjugates using an aqueous two phase suspension polymerization process. The aqueous two phase suspension polymerization process enabled rapid microsphere formation without the use of an organic phase, surfactants, mechanical strain, or toxic radical initiators. The microspheres’ size distribution was modulated by varying the protein-polymer conformation in the pre-polymer solution. Notably, the protein’s ligand-induced, nanometer scale conformational change translated to maximum hydrogel volume changes of 76±10%. The magnitude of the microspheres’ volume change was tuned by varying the crosslinking time and ligand identity. After characterizing the microspheres’ dynamic properties, we encapsulated two important therapeutic proteins, vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2), in the hydrogel microspheres and characterized how the microspheres’ dynamic properties controlled their release. Significantly, the aqueous two phase suspension polymerization process enabled high encapsulation efficiencies (65.8±4.8% and 79.5±3.0% for VEGF and BMP-2, respectively). Also, the microspheres’ ligand-induced volume change triggered VEGF and BMP-2 release at specific, predetermined times. There are hundreds of proteins that undergo well characterized conformational changes that could be processed into hydrogel microspheres via aqueous two phase suspension polymerizations. Therefore, this approach could be used to form dynamic, growth factor-releasing hydrogel microspheres that respond to a broad range of specific biochemical ligands. PMID:21029793

  20. Gastrointestinal Motility Disorders and Acupuncture

    PubMed Central

    Yin, Jieyun; Chen, Jiande D Z

    2010-01-01

    During the last decades, numerous studies have been performed to investigate the effects and mechanisms of acupuncture or electroacupuncture (EA) on gastrointestinal motility and patients with functional gastrointestinal diseases. A PubMed search was performed on this topic and all available studies published in English have been reviewed and evaluated. This review is organized based on the gastrointestinal organ (from the esophagus to the colon), components of gastrointestinal motility and the functional diseases related to specific motility disorders. It was found that the effects of acupuncture or EA on gastrointestinal motility were fairly consistent and the major acupuncture points used in these studies were ST36 and PC6. Gastric motility has been mostly studied, whereas much less information is available on the effect of EA on small and large intestinal motility or related disorders. A number of clinical studies have been published, investigating the therapeutic effects of EA on a number of functional gastrointestinal diseases, such as gastroesophageal reflux, functional dyspepsia and irritable bowel syndrome. However, the findings of these clinical studies were inconclusive. In summary, acupuncture or EA is able to alter gastrointestinal motility functions and improve gastrointestinal motility disorders. However, more studies are needed to establish the therapeutic roles of EA in treating functional gastrointestinal diseases. PMID:20363196

  1. Cell specific, variable density, polymer microspheres

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Molday, Robert S. (Inventor)

    1977-01-01

    Biocompatible polymeric microspheres having an average diameter below about 3 microns and having density at least 15% greater or lesser than organic cells and having covalent binding sites are provided in accordance with this invention. The microspheres are obtained by copolymerizing a hydroxy or amine substituted acrylic monomer such as hydroxyethylmethacrylate with a light or dense comonomer such as a fluoromonomer. A lectin or antibody is bound to the hydroxy or amine site of the bead to provide cell specificity. When added to a cell suspension the marked bead will specifically label the cell membrane by binding to specific receptor sites thereon. The labelled membrane can then be separated by density gradient centrifugation.

  2. Quantum Magnetomechanics with Levitating Superconducting Microspheres

    NASA Astrophysics Data System (ADS)

    Romero-Isart, O.; Clemente, L.; Navau, C.; Sanchez, A.; Cirac, J. I.

    2012-10-01

    We show that by magnetically trapping a superconducting microsphere close to a quantum circuit, it is possible to perform ground-state cooling and prepare quantum superpositions of the center-of-mass motion of the microsphere. Due to the absence of clamping losses and time-dependent electromagnetic fields, the mechanical motion of micrometer-sized metallic spheres in the Meissner state is predicted to be very well isolated from the environment. Hence, we propose to combine the technology of magnetic microtraps and superconducting qubits to bring relatively large objects to the quantum regime.

  3. Unusual imaging properties of superresolution microspheres.

    PubMed

    Li, Pin-Yi; Tsao, Yang; Liu, Yun-Ju; Lou, Zong-Xing; Lee, Wei-Li; Chu, Shi-Wei; Chang, Chih-Wei

    2016-07-25

    We employ a self-assembly method to fabricate dielectric microsphere arrays that can be transferred to any desired positions. The arrays not only enable far-field, broad-band, high-speed, large-area, and wide-angle field of views but also achieve superresolution reaching λ/6.4. We also find that many proposed theories are insufficient to explain the imaging properties; including the achieved superresolution, effects of immersion, and unusual size-dependent magnification. The half-immersed microspheres certainly do not behave like any ordinary solid immersion lenses and new mechanisms must be incorporated to explain their unusual imaging properties. PMID:27464101

  4. Laser velocimetry with fluorescent dye-doped polystyrene microspheres.

    PubMed

    Lowe, K Todd; Maisto, Pietro; Byun, Gwibo; Simpson, Roger L; Verkamp, Max; Danehy, Paul M; Tiemsin, Pacita I; Wohl, Christopher J

    2013-04-15

    Simultaneous Mie scattering and laser-induced fluorescence (LIF) signals are obtained from individual polystyrene latex microspheres dispersed in an air flow. Microspheres less than 1 μm mean diameter were doped with two organic fluorescent dyes, Rhodamine B (RhB) and dichlorofluorescein (DCF), intended either to provide improved particle-based flow velocimetry in the vicinity of surfaces or to provide scalar flow information (e.g., marking one of two fluid streams). Both dyes exhibit measureable fluorescence signals that are on the order of 10(-3) to 10(-4) times weaker than the simultaneously measured Mie signals. It is determined that at the conditions measured, 95.5% of RhB LIF signals and 32.2% of DCF signals provide valid laser-Doppler velocimetry measurements compared with the Mie scattering validation rate with 6.5 W of 532 nm excitation, while RhB excited with 1.0 W incident laser power still exhibits 95.4% valid velocimetry signals from the LIF channel. The results suggest that the method is applicable to wind tunnel measurements near walls where laser flare can be a limiting factor and monodisperse particles are essential.

  5. Laser velocimetry with fluorescent dye-doped polystyrene microspheres.

    PubMed

    Lowe, K Todd; Maisto, Pietro; Byun, Gwibo; Simpson, Roger L; Verkamp, Max; Danehy, Paul M; Tiemsin, Pacita I; Wohl, Christopher J

    2013-04-15

    Simultaneous Mie scattering and laser-induced fluorescence (LIF) signals are obtained from individual polystyrene latex microspheres dispersed in an air flow. Microspheres less than 1 μm mean diameter were doped with two organic fluorescent dyes, Rhodamine B (RhB) and dichlorofluorescein (DCF), intended either to provide improved particle-based flow velocimetry in the vicinity of surfaces or to provide scalar flow information (e.g., marking one of two fluid streams). Both dyes exhibit measureable fluorescence signals that are on the order of 10(-3) to 10(-4) times weaker than the simultaneously measured Mie signals. It is determined that at the conditions measured, 95.5% of RhB LIF signals and 32.2% of DCF signals provide valid laser-Doppler velocimetry measurements compared with the Mie scattering validation rate with 6.5 W of 532 nm excitation, while RhB excited with 1.0 W incident laser power still exhibits 95.4% valid velocimetry signals from the LIF channel. The results suggest that the method is applicable to wind tunnel measurements near walls where laser flare can be a limiting factor and monodisperse particles are essential. PMID:23595429

  6. Management of gastrointestinal haemorrhage

    PubMed Central

    Ghosh, S; Watts, D; Kinnear, M

    2002-01-01

    A variety of endoscopic haemostatic techniques have enabled major advances in the management of not only bleeding peptic ulcers and bleeding varices, but also in a variety of bleeding lesions in the small intestine and in the colon. Indeed, the development and widespread implementation of endoscopic haemostasis has been one of the most important developments in clinical gastroenterology in the past two decades. An increasingly ageing cohort of patients with multiple co-morbidity are being treated and therefore improving the outcome of gastrointestinal bleeding continues to pose major challenges. PMID:11796865

  7. Wound-healing evaluation of entrapped active agents into protein microspheres over cellulosic gauzes.

    PubMed

    Silva, Raquel; Ferreira, Helena; Matamá, Teresa; Gomes, Andreia C; Cavaco-Paulo, Artur

    2012-11-01

    The use of active ingredients in wound management have evolved alongside the pharmaceutical agents and dressings used to deliver them. However, the development of gauzes, dressings with specific properties, still remains a challenge for several medical applications. A new methodology for the controlled release of active components for the healing of burn wounds is proposed herein. Cotton and non-woven bandages have been cationised to promote the attachment of protein microspheres. The active agents, piroxicam and vegetable oil, were entrapped into the microspheres using ultrasound energy. Active agents were released from the microspheres by a change in pH. Wound healing was assessed through the use of standardised burn wounds induced by a cautery in human full-thickness skin equivalents (EpidermFT). The best re-epithelialisation and fastest wound closure was observed in wounds treated with proteinaceous microspheres attached to gauzes, after six days of healing, in comparison with commercial collagen dressing and other controls. Furthermore, the ability of these materials to reduce the inflammation process, together with healing improvement, makes these biomaterials suitable for wound-dressing applications.

  8. Nanofibrous spongy microspheres enhance odontogenic differentiation of human dental pulp stem cells.

    PubMed

    Kuang, Rong; Zhang, Zhanpeng; Jin, Xiaobing; Hu, Jiang; Gupte, Melanie J; Ni, Longxing; Ma, Peter X

    2015-09-16

    Dentin regeneration is challenging due to its complicated anatomical structure and the shortage of odontoblasts. In this study, a novel injectable cell carrier, nanofibrous spongy microspheres (NF-SMS), is developed for dentin regeneration. Biodegradable and biocompatible poly(l-lactic acid)-block-poly(l-lysine) are synthesized and fabricated into NF-SMS using self-assembly and thermally induced phase separation techniques. It is hypothesized that NF-SMS with interconnected pores and nanofibers can enhance the proliferation and odontogenic differentiation of human dental pulp stem cells (hDPSCs), compared to nanofibrous microspheres (NF-MS) without pore structure and conventional solid microspheres (S-MS) with neither nanofibers nor pore structure. During the first 9 d in culture, hDPSCs proliferate significantly faster on NF-SMS than on NF-MS or S-MS (p < 0.05). Following in vitro odontogenic induction, all the examined odontogenic genes (alkaline phosphatase content, osteocalcin, bone sialoprotein, collagen 1, dentin sialophosphoprotein (DSPP)), calcium content, and DSPP protein content are found significantly higher in the NF-SMS group than in the control groups. Furthermore, 6 weeks after subcutaneous injection of hDPSCs and microspheres into nude mice, histological analysis shows that NF-SMS support superior dentin-like tissue formation compared to NF-MS or S-MS. Taken together, NF-SMS have great potential as an injectable cell carrier for dentin regeneration.

  9. Nanofibrous spongy microspheres enhance odontogenic differentiation of human dental pulp stem cells.

    PubMed

    Kuang, Rong; Zhang, Zhanpeng; Jin, Xiaobing; Hu, Jiang; Gupte, Melanie J; Ni, Longxing; Ma, Peter X

    2015-09-16

    Dentin regeneration is challenging due to its complicated anatomical structure and the shortage of odontoblasts. In this study, a novel injectable cell carrier, nanofibrous spongy microspheres (NF-SMS), is developed for dentin regeneration. Biodegradable and biocompatible poly(l-lactic acid)-block-poly(l-lysine) are synthesized and fabricated into NF-SMS using self-assembly and thermally induced phase separation techniques. It is hypothesized that NF-SMS with interconnected pores and nanofibers can enhance the proliferation and odontogenic differentiation of human dental pulp stem cells (hDPSCs), compared to nanofibrous microspheres (NF-MS) without pore structure and conventional solid microspheres (S-MS) with neither nanofibers nor pore structure. During the first 9 d in culture, hDPSCs proliferate significantly faster on NF-SMS than on NF-MS or S-MS (p < 0.05). Following in vitro odontogenic induction, all the examined odontogenic genes (alkaline phosphatase content, osteocalcin, bone sialoprotein, collagen 1, dentin sialophosphoprotein (DSPP)), calcium content, and DSPP protein content are found significantly higher in the NF-SMS group than in the control groups. Furthermore, 6 weeks after subcutaneous injection of hDPSCs and microspheres into nude mice, histological analysis shows that NF-SMS support superior dentin-like tissue formation compared to NF-MS or S-MS. Taken together, NF-SMS have great potential as an injectable cell carrier for dentin regeneration. PMID:26138254

  10. Immunization Against Cutaneous Leishmaniasis by Alginate Microspheres Loaded With Autoclaved Leishmania Major (ALM) and Quillaja Saponins.

    PubMed

    Tafaghodi, Mohsen; Eskandari, Maryam; Khamesipour, Ali; Jaafari, Mahmoud Reza

    2016-01-01

    Leishmania antigens are weak immunogens and need to be potentiated by various adjuvants and delivery systems. Alginate microspheres as antigen delivery system and Quillaja saponins (QS) as immunoadjuvant have been used to enhance the immune response against Autoclaved Leishmania major (ALM). Microspheres were prepared by an emulsification technique and characterized for size, encapsulation efficiency and release profile of encapsulates. BALB/c mice were immunized three times in 3-weeks intervals using ALM plus QS loaded microspheres [(ALM+QS)ALG], ALM encapsulated with alginate microspheres [(ALM)ALG], (ALM)ALG + QS, ALM + QS, ALM alone or PBS. The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, were observed in mice immunized with (ALM)ALG+QS. The (ALM+QS)ALG, ALM and PBS groups showed the least protection and highest swelling, while the (ALM)ALG and ALM+QS showed an intermediate protection with no significant difference. The mice immunized with (ALM+QS)ALG showed the highest IgG2a/IgG1 ratio (P<0.05). The highest IFN-γ and IL-4 production was seen in ALM+QS (P<0.01). It is concluded that QS adjuvant has a mixed Th1/Th2 effect and has increased both humoral and cellular immune responses. PMID:27642328

  11. Effect of Eu, Tb codoping on the luminescent properties of Y2O3 hollow microspheres

    NASA Astrophysics Data System (ADS)

    Jiu, Hongfang; Fu, Yuehua; Zhang, Lixin; Sun, Yixin; Wang, Yuanzhong

    2012-12-01

    Y2O3:Eu3+, Tb3+ hollow microspheres are prepared with different doping concentration of Eu3+ and Tb3+ ions and synthesizing temperatures from 700 to 1000 °C via a urea-based homogeneous precipitation technique with colloidal melamine formaldehyde (MF) microspheres as templates followed by a subsequent calcination process. The resulted hollow microspheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The results of XRD indicate that the crystallinity of the synthesized samples increases with enhancing the calcination temperature. The photoluminescence spectra indicate the Eu3+ and Tb3+ co-doped Y2O3 microspheres show five main emission peaks: three at 591, 609 and 629 nm originate from Eu3+ and two at 482 and 541 nm originate from Tb3+, under excitation of 250-340 nm irradiation. The luminescence color could be changed by varying the excitation wavelength. Different concentrations of Eu3+ and Tb3+ ions were induced into the Y2O3 lattice and the energy transfer from Tb3+ to Eu3+ ions in these phosphors was found.

  12. Binary breath figures for straightforward and controllable self-assembly of microspherical caps.

    PubMed

    Gong, Jianliang; Xu, Bingang; Tao, Xiaoming; Li, Lei

    2016-05-11

    The intense interest surrounding asymmetrical microparticles originates from their unique anisotropic properties and promising applications. In this work, direct self-assembly of polymeric microspherical caps without the assistance of any additives has been achieved by using low-surface-tension methanol (MeOH) and high-surface-tension water as binary breath figures (BFs). With the evaporation of polystyrene (PS) solution containing low-boiling-point solvent in the binary vapors, the formed MeOH BFs could quickly diffuse into solution, while water BFs tended to remain at the solution surface. This led to the formation of a gradient nonsolvent layer at the vapor/solution interface, which induced the formation of nuclei and guided further asymmetrical growth of polymer particles. After the spontaneous removal of MeOH, water and residual solvent by evaporation, polymeric microspherical caps were left on the substrate. Through controlling the proportion of water introduced by adjusting the ratios of MeOH and water, polymeric microspherical caps with a range of controllable shapes (divided at different positions of a sphere) were successfully obtained. The formation mechanism was explained based on the difference of vapor pressure, surface tension and miscibility between the employed solvents and nonsolvents. A solvent possessing a high vapor pressure, low surface tension and good miscibility with MeOH contributed to the formation of microspherical caps. This flexible, green and straightforward technique is a nondestructive strategy, and avoids complicated work on design, preparation and removal of hard templates and additives. PMID:27139817

  13. Formulation, optimization and evaluation of spray-dried mucoadhesive microspheres as intranasal carriers for Valsartan.

    PubMed

    Pardeshi, Chandrakant V; Rajput, Pravin V; Belgamwar, Veena S; Tekade, Avinash R

    2012-01-01

    This investigation deals with the intranasal delivery of Valsartan, encapsulated in HPMC-based spray-dried mucoadhesive microspheres, with an aim to provide rapid absorption and quick onset of action for treating hypertension. A 2³-factorial design has been employed for the assessment of influence of three independent variables, namely inlet temperature, feed-flow rate and drug-polymer ratio on production yield, particle size and in vitro drug diffusion of the prepared microspheres. Microspheres were evaluated for particle size, entrapment efficiency, swelling property, in vitro mucoadhesion, in vitro drug diffusion, ex vivo drug permeation, histopathological examination and stability studies. The results of differential scanning calorimetry, X-ray diffraction and scanning electron microscopy revealed molecular dispersion of Valsartan into microspheres with spherical shape and smooth surface. Optimized formulation indicated good mucoadhesion with no severe sign of damage on nasal mucosa. Results of the non-invasive animal studies in dexamethasone-induced hypertensive rat model suggested the suitability of investigated drug delivery system for intranasal administration.

  14. pH-Sensitive oral insulin delivery systems using Eudragit microspheres.

    PubMed

    Mundargi, Raghavendra C; Rangaswamy, Vidhya; Aminabhavi, Tejraj M

    2011-08-01

    In this paper, we present in vitro and in vivo release data on pH-sensitive microspheres of Eudragit L100, Eudragit RS100 and their blend systems prepared by double emulsion-solvent evaporation technique for oral delivery of insulin. Of the three systems developed, Eudragit L100 was chosen for preclinical studies. Insulin was encapsulated and in vitro experiments performed on insulin-loaded microspheres in pH 1.2 media did not release insulin during the first 2 h, but maximum insulin was released in pH 7.4 buffer media from 4 to 6 h. The microspheres were characterized by scanning electron microscopy to understand particle size, shape and surface morphology. The size of microspheres ranged between 1 and 40 μm. Circular dichroism spectra indicated the structural integrity of insulin during encapsulation as well as after its release in pH 7.4 buffer media. The in vivo release studies on diabetic-induced rat models exhibited maximum inhibition of up to 86%, suggesting absorption of insulin in the intestine.

  15. PLGA microspheres for the delivery of a novel subunit TB vaccine.

    PubMed

    Kirby, Daniel J; Rosenkrands, Ida; Agger, Else M; Andersen, Peter; Coombes, Allan G A; Perrie, Yvonne

    2008-05-01

    Biodegradable poly(dl-lactide-co-glycolide) microspheres were prepared using a modified double emulsion solvent evaporation method for the delivery of the subunit tuberculosis vaccine (Ag85B-ESAT-6), a fusion protein of the immunodominant antigens 6-kDa early secretory antigenic target (ESAT-6) and antigen 85B (Ag85B). Addition of the cationic lipid dimethyl dioctadecylammonium bromide (DDA) and the immunostimulatory trehalose 6,6'-dibehenate (TDB), either separately or in combination, was investigated for the effect on particle size and distribution, antigen entrapment efficiency, in vitro release profiles and in vivo performance. Optimised formulation parameters yielded microspheres within the desired sub-10 microm range (1.50 +/- 0.13 microm), whilst exhibiting a high antigen entrapment efficiency (95 +/- 1.2%) and prolonged release profiles. Although the microsphere formulations induced a cell-mediated immune response and raised specific antibodies after immunisation, this was inferior to the levels achieved with liposomes composed of the same adjuvants (DDA-TDB), demonstrating that liposomes are more effective vaccine delivery systems compared with microspheres.

  16. Immunization Against Cutaneous Leishmaniasis by Alginate Microspheres Loaded With Autoclaved Leishmania Major (ALM) and Quillaja Saponins

    PubMed Central

    Tafaghodi, Mohsen; Eskandari, Maryam; Khamesipour, Ali; Jaafari, Mahmoud Reza

    2016-01-01

    Leishmania antigens are weak immunogens and need to be potentiated by various adjuvants and delivery systems. Alginate microspheres as antigen delivery system and Quillaja saponins (QS) as immunoadjuvant have been used to enhance the immune response against Autoclaved Leishmania major (ALM). Microspheres were prepared by an emulsification technique and characterized for size, encapsulation efficiency and release profile of encapsulates. BALB/c mice were immunized three times in 3-weeks intervals using ALM plus QS loaded microspheres [(ALM+QS)ALG], ALM encapsulated with alginate microspheres [(ALM)ALG], (ALM)ALG + QS, ALM + QS, ALM alone or PBS. The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, were observed in mice immunized with (ALM)ALG+QS. The (ALM+QS)ALG, ALM and PBS groups showed the least protection and highest swelling, while the (ALM)ALG and ALM+QS showed an intermediate protection with no significant difference. The mice immunized with (ALM+QS)ALG showed the highest IgG2a/IgG1 ratio (P<0.05). The highest IFN-γ and IL-4 production was seen in ALM+QS (P<0.01). It is concluded that QS adjuvant has a mixed Th1/Th2 effect and has increased both humoral and cellular immune responses. PMID:27642328

  17. Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery: in vitro-in vivo evaluation.

    PubMed

    Pal, Dilipkumar; Nayak, Amit Kumar

    2012-04-01

    Novel tamarind seed polysaccharide (TSP)-alginate mucoadhesive microspheres were prepared using TSP and alginate as blend in different ratios with different calcium chloride (CaCl(2)) concentration as a cross linker by ionotropic gelation. The prepared microspheres were of spherical shape having rough surfaces, and average particle sizes within the range of 752.12 ± 6.42 to 948.49 ± 20.92 µm. The drug entrapment efficiency of these microspheres were within the range between 58.12 ± 2.42 to 82.78 ± 3.43% w/w. Fourier transform infrared (FTIR) studies indicated that there were no reactions between gliclazide, and polymers (TSP, and sodium alginate) used. Different formulations of gliclazide loaded TSP-alginate microspheres showed prolonged in vitro release profiles of gliclazide over 12 hours in both stomach pH (pH 1.2), and intestinal pH (pH 7.4). It was found that the gliclazide release in gastric pH was comparatively slow and sustained than intestinal pH. These TSP-alginate microspheres also exhibited good mucoadhesivity. The in vivo studies on alloxan-induced diabetic rats (Animal Ethical Committee registration number: IFTM/837ac/0160) demonstrated the significant hypoglycemic effect of selected formulation of TSP-alginate mucoadhesive microspheres containing gliclazide on oral administration. This developed gliclazide loaded new TSP-alginate mucoadhesive microspheres may be very much useful for prolonged systemic absorption of gliclazide for proper maintaining blood glucose level and advanced patient compliance.

  18. Influence of magnesium stearate on the physicochemical and pharmacodynamic characteristics of insulin-loaded Eudragit entrapped mucoadhesive microspheres.

    PubMed

    Momoh, Mumuni A; Kenechukwu, Franklin C; Nnamani, Petra O; Umetiti, Jennifer C

    2015-01-01

    Effective oral insulin delivery has remained a challenge to the pharmaceutical industry. This study was designed to evaluate the effect of magnesium stearate on the properties of insulin-loaded Eudragit® RL 100 entrapped mucoadhesive microspheres. Microspheres containing Eudragit® RL 100, insulin, and varying concentrations of magnesium stearate (agglomeration-preventing agent) were prepared by emulsification-coacervation method and characterized with respect to differential scanning calorimetry (DSC), morphology, particle size, loading efficiency, mucoadhesive and micromeritics properties. The in vitro release of insulin from the microspheres was performed in simulated intestinal fluid (SIF, pH 7.2) while the in vivo hypoglycemic effect was investigated by monitoring the plasma glucose level of the alloxan-induced diabetic rats after oral administration. Stable, spherical, brownish, mucoadhesive, discrete and free flowing insulin-loaded microspheres were formed. While the average particle size and mucoadhesiveness of the microspheres increased with an increase in the proportion of magnesium stearate, loading efficiency generally decreased. After 12 h, microspheres prepared with Eudragit® RL 100: magnesium stearate ratios of 15:1, 15:2, 15:3 and 15:4 released 68.20 ± 1.57, 79.40 ± 1.52, 76.60 ± 1.93 and 70.00 ± 1.00 (%) of insulin, respectively. Reduction in the blood glucose level for the subcutaneously (sc) administered insulin was significantly (p ≤ 0.05) higher than for most of the formulations. However, the blood glucose reduction effect produced by the orally administered insulin-loaded microspheres prepared with four parts of magnesium stearate and fifteen parts of Eudragit® RL 100 after 12 h was equal to that produced by subcutaneously administered insulin solution. The results of this study can suggest that this carrier system could be an alternative for the delivery of insulin.

  19. Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery: in vitro-in vivo evaluation.

    PubMed

    Pal, Dilipkumar; Nayak, Amit Kumar

    2012-04-01

    Novel tamarind seed polysaccharide (TSP)-alginate mucoadhesive microspheres were prepared using TSP and alginate as blend in different ratios with different calcium chloride (CaCl(2)) concentration as a cross linker by ionotropic gelation. The prepared microspheres were of spherical shape having rough surfaces, and average particle sizes within the range of 752.12 ± 6.42 to 948.49 ± 20.92 µm. The drug entrapment efficiency of these microspheres were within the range between 58.12 ± 2.42 to 82.78 ± 3.43% w/w. Fourier transform infrared (FTIR) studies indicated that there were no reactions between gliclazide, and polymers (TSP, and sodium alginate) used. Different formulations of gliclazide loaded TSP-alginate microspheres showed prolonged in vitro release profiles of gliclazide over 12 hours in both stomach pH (pH 1.2), and intestinal pH (pH 7.4). It was found that the gliclazide release in gastric pH was comparatively slow and sustained than intestinal pH. These TSP-alginate microspheres also exhibited good mucoadhesivity. The in vivo studies on alloxan-induced diabetic rats (Animal Ethical Committee registration number: IFTM/837ac/0160) demonstrated the significant hypoglycemic effect of selected formulation of TSP-alginate mucoadhesive microspheres containing gliclazide on oral administration. This developed gliclazide loaded new TSP-alginate mucoadhesive microspheres may be very much useful for prolonged systemic absorption of gliclazide for proper maintaining blood glucose level and advanced patient compliance. PMID:22352984

  20. Microbiota regulate the ability of lung dendritic cells to induce IgA class-switch recombination and generate protective gastrointestinal immune responses

    PubMed Central

    Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G.; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea

    2016-01-01

    Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103+ and CD24+CD11b+ DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell–dependent or –independent pathways. Compared with lung DCs (LDC), lung CD64+ macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid–dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT–specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs. PMID:26712806

  1. Microbiota regulate the ability of lung dendritic cells to induce IgA class-switch recombination and generate protective gastrointestinal immune responses.

    PubMed

    Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea; Mehandru, Saurabh

    2016-01-11

    Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103(+) and CD24(+)CD11b(+) DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell-dependent or -independent pathways. Compared with lung DCs (LDC), lung CD64(+) macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid-dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT-specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs.

  2. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE ACTH ANDCORTICOSTERONE RELEASE AND CAUSE CONDITIONED TASTE AVERSION.

    EPA Science Inventory

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a LOEL of 12.5mg/kg. The mechanism for these effects is unk...

  3. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE HPA-AXIS ACTIVATION AND CAUSE CONDITIONED TASTE AVERSION.

    EPA Science Inventory

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a NOEL equal to 5mg/kg. The mechanism for these effects ...

  4. Gastrointestinal Headache; a Narrative Review

    PubMed Central

    T Noghani, Majid; Rezaeizadeh, Hossein; Fazljoo, Sayed Mohammad Baqer; Keshavarz, Mansoor

    2016-01-01

    There are studies reporting primary headaches to be associated with gastrointestinal disorders, and some report resolution of headache following the treatment of the associated gastrointestinal disorder. Headache disorders are classified by The International Headache Society as primary or secondary; however, among the secondary headaches, those attributed to gastrointestinal disorders are not appreciated. Therefore, we aimed to review the literature to provide evidence for headaches, which originate from the gastrointestinal system. Gastrointestinal disorders that are reported to be associated with primary headaches include dyspepsia, gastro esophageal reflux disease (GERD), constipation, functional abdominal pain, inflammatory bowel syndrome (IBS), inflammatory bowel disorders (IBD), celiac disease, and helicobacter pylori (H. Pylori) infection. Some studies have demonstrated remission or improvement of headache following the treatment of the accompanying gastrointestinal disorders. Hypotheses explaining this association are considered to be central sensitization and parasympathetic referred pain, serotonin pathways, autonomic nervous system dysfunction, systemic vasculopathy, and food allergy. Traditional Persian physicians, namely Ebn-e-Sina (Avicenna) and Râzi (Rhazes) believed in a type of headache originating from disorders of the stomach and named it as an individual entity, the "Participatory Headache of Gastric Origin". We suggest providing a unique diagnostic entity for headaches coexisting with any gastrointestinal abnormality that are improved or cured along with the treatment of the gastrointestinal disorder. PMID:27800536

  5. Shell-in-Shell TiO2 hollow microspheres and optimized application in light-trapping perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Sun, Hongxia; Ruan, Peng; Bao, Zhongqiu; Chen, Lei; Zhou, Xingfu

    2015-02-01

    The shell-in-shell structured TiO2 hollow microspheres with enhanced light scattering ability were synthesized via a facile one step hydrothermal process. The diameter of the microsphere is about 1.5 μm, the core of the unique shell-in-shell structure is composed of TiO2 nanoparticles with a diameter of about 15 nm, while the shell is constructed with ∼50 nm TiO2 nanocubes. The hollow space between the outer shell and the inner shell is about 230 nm. The formation mechanism of the unique shell-in-shell structure is interpreted. The design and the optimized application of shell-in-shell structured TiO2 hollow microspheres in the light-trapping perovskite solar cells are also investigated. Owing to the light scattering properties of the shell-in-shell structure of the hollow microsphere, the optimized photoelectrode exhibits an enhanced photoelectric conversion efficiency of 4.29% using perovskite CH3NH3PbI3 as the sensitizer. The shell-in-shell hollow TiO2 microsphere shows a 21.2% increase in conversion efficiency when compared with P25 nanoparticels photoanode. The conversion efficiency enhancement is mainly attributed to the increase of short-current density induced by the light scattering effect.

  6. Design and evaluation of surface and adjuvant modified PLGA microspheres for uptake by dendritic cells to improve vaccine responses.

    PubMed

    Salvador, Aiala; Sandgren, Kerrie J; Liang, Frank; Thompson, Elizabeth A; Koup, Richard A; Pedraz, José Luis; Hernandez, Rosa Maria; Loré, Karin; Igartua, Manoli

    2015-12-30

    Designing strategies for targeting antigens to dendritic cells is a major goal in vaccinology. Here, PLGA (poly lactic-co-glycolic acid) microspheres and with several surface modifications that affect to their uptake by human blood primary dendritic cells and monocytes have been evaluated. Higher uptake was found by all the cell types when cationic microspheres (PLGA modified with polyethylene imine) were used. These cationic particles were in vivo evaluated in mice. In addition, MPLA(1) or poly(I:C)(2) and α-GalCer(3) were also encapsulated to address their adjuvant effect. All the microspheres were able to produce humoral immune responses, albeit they were higher for cationic microspheres. Moreover, surface charge seemed to have a role on biasing the immune response; cationic microspheres induced higher IFN-γ levels, indicative of Th1 activation, while unmodified ones mainly triggered IL4 and IL17A release, showing Th2 activation. Thus, we have shown here the potential and versatility of these MS, which may be tailored to needs.

  7. Method for introduction of gases into microspheres

    DOEpatents

    Hendricks, C.D.; Koo, J.C.; Rosencwaig, A.

    A method is described for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500..mu.. with both thin walls (0.5 to 4/sub ..mu../) and thick walls (5 to 20/sub ..mu../) that contain various fill gases, such as Ar, Kr, Xe, Br, D, H/sub 2/, DT, He, N/sub 2/, Ne, CO/sub 2/, etc., in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-form-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace.

  8. Preparation of small bio-compatible microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor); Yen, Shiao-Ping S. (Inventor); Dreyer, William J. (Inventor)

    1979-01-01

    Small, round, bio-compatible microspheres capable of covalently bonding proteins and having a uniform diameter below about 3500 A are prepared by substantially instantaneously initiating polymerization of an aqueous emulsion containing no more than 35% total monomer including an acrylic monomer substituted with a covalently bondable group such a hydroxyl, amino or carboxyl and a minor amount of a cross-linking agent.

  9. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    NASA Technical Reports Server (NTRS)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  10. 21 CFR 870.1360 - Trace microsphere.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... within or to an organ. (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or notice of completion of a PDP is required to be filed with the Food... other trace microsphere shall have an approved PMA or a declared completed PDP in effect before...

  11. 21 CFR 870.1360 - Trace microsphere.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... within or to an organ. (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or notice of completion of a PDP is required to be filed with the Food... other trace microsphere shall have an approved PMA or a declared completed PDP in effect before...

  12. PLGA/alginate composite microspheres for hydrophilic protein delivery.

    PubMed

    Zhai, Peng; Chen, X B; Schreyer, David J

    2015-11-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate.

  13. Highly biocompatible nanofibrous microspheres self-assembled from chitin in NaOH/urea aqueous solution as cell carriers.

    PubMed

    Duan, Bo; Zheng, Xing; Xia, Zhixiong; Fan, Xiaoli; Guo, Lin; Liu, Jianfeng; Wang, Yanfeng; Ye, Qifa; Zhang, Lina

    2015-04-20

    In this work, chitin microspheres (NCM) having a nanofibrous architecture were constructed using a "bottom-up" fabrication pathway. The chitin chains rapidly self-assembled into nanofibers in NaOH/urea aqueous solution by a thermally induced method and subsequently formed weaved microspheres. The diameter of the chitin nanofibers and the size of the NCM were tunable by controlling the temperature and the processing parameters to be in the range from 26 to 55 nm and 3 to 130 μm, respectively. As a result of the nanofibrous surface and the inherent biocompatibility of chitin, cells could adhere to the chitin microspheres and showed a high attachment efficiency, indicating the great potential of the NCM for 3D cell microcarriers.

  14. Active self-healing encapsulation of vaccine antigens in PLGA microspheres

    PubMed Central

    Desai, Kashappa-Goud H.; Schwendeman, Steven P.

    2013-01-01

    Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer

  15. The Structural Basis for the Prevention of Nonsteroidal Antiinflammatory Drug-Induced Gastrointestinal Tract Damage by the C-Lobe of Bovine Colostrum Lactoferrin

    PubMed Central

    Mir, Rafia; Singh, Nagendra; Vikram, Gopalakrishnapillai; Kumar, Ramasamy Prem; Sinha, Mau; Bhushan, Asha; Kaur, Punit; Srinivasan, Alagiri; Sharma, Sujata; Singh, Tej P.

    2009-01-01

    Abstract Nonsteroidal antiinflammatory drugs (NSAIDs), due to their good efficacy in the treatment of pain, inflammation, and fever, are among the most prescribed class of medicines in the world. The main drawback of NSAIDs is that they induce gastric complications such as peptic ulceration and injury to the intestine. Four NSAIDs, indomethacin, diclofenac, aspirin, and ibuprofen were selected to induce gastropathy in mouse models. It was found that the addition of C-terminal half of bovine lactoferrin (C-lobe) reversed the NSAID-induced injuries to the extent of 47–70% whereas the coadministration of C-lobe prevented it significantly. The C-lobe was prepared proteolytically using serine proteases. The binding studies of C-lobe with NSAIDs showed that these compounds bind to C-lobe with affinities ranging from 2.6 to 4.8 × 10−4 M. The complexes of C-lobe were prepared with the above four NSAIDs. All four complexes were crystallized and their detailed three-dimensional structures were determined using x-ray crystallographic method. The structures showed that all the four NSAID molecules bound to C-lobe at the newly identified ligand binding site in C-lobe that is formed involving two α-helices, α10 and α11. The ligand binding site is separated from the well known iron binding site by the longest and the most stable β-strand, βj, in the structure. Similar results were also obtained with the full length lactoferrin molecule. This novel, to our knowledge, binding site in C-lobe of lactoferrin shows a good complementarity for the acidic and lipophilic compounds such as NSAIDs. We believe this indicates that C-lobe of lactoferrin can be exploited for the prevention of NSAID-induced gastropathy. PMID:20006955

  16. Effect of long-term olanzapine treatment on meal-induced insulin sensitization and on gastrointestinal peptides in female Sprague-Dawley rats.

    PubMed

    Hegedűs, Csaba; Kovács, Diána; Kiss, Rita; Sári, Réka; Németh, József; Szilvássy, Zoltán; Peitl, Barna

    2015-12-01

    Meal-induced insulin sensitization (MIS), an endogenous adaptive mechanism is activated post-prandially. Reduced MIS leads to diabetes, but its activation improves insulin sensitivity. MIS is preserved to single olanzapine administration, therefore we aimed to investigate the chronic effect of olanzapine on fasted-state insulin sensitivity and on MIS in female Sprague-Dawley rats. Daily food and water intake, stool and urine production and body weight were determined. The MIS was characterized by a rapid insulin sensitivity test. Fasting hepatic and peripheral insulin sensitivity were determined by a hyperinsulinaemic euglycaemic glucose clamping supplemented with radiotracer technique. Fasted and post-prandial blood samples were obtained for plasma insulin, leptin, ghrelin, amylin, GLP-1, GIP, PYY and PP determination. Adiposity was characterized by weighing intra-abdominal and inguinal fat pads. Olanzapine caused hepatic insulin resistance and a reduced metabolic clearance rate of insulin, but the MIS retained its function. Body weight and adiposity were enhanced, but olanzapine failed to increase food intake. Fasting insulin and leptin were elevated and the post-prandial reduction in ghrelin level was inhibited by olanzapine.The MIS remained functionally intact after long-term olanzapine treatment. Altered insulin, leptin and ghrelin levels indicate olanzapine-induced metabolic derangements. Pharmacological activation of MIS could potentially be exploited to treat or prevent olanzapine-induced insulin resistance. PMID:26349558

  17. Effect of dopamine-related drugs on duodenal ulcer induced by cysteamine or propionitrile: prevention and aggravation may not be mediated by gastrointestinal secretory changes in the rat

    SciTech Connect

    Gallagher, G.; Brown, A.; Szabo, S.

    1987-03-01

    Dose- and time-response studies have been performed with dopamine agonists and antagonists using the cysteamine and propionitrile duodenal ulcer models in the rat. The experiments demonstrate that the chemically induced duodenal ulcer is prevented by bromocriptine, lergotrile and reduced by apomorphine or L-dopa. Aggravation of cysteamine-induced duodenal ulcer was seen especially after (-)-butaclamol, (-)-sulpiride, haloperidol and, less effectively, after other dopaminergic antagonists. The duodenal antiulcerogenic action of dopamine agonists was more prominent after chronic administration than after a single dose, whereas the opposite was found concerning the proulcerogenic effect of dopamine antagonists. In the chronic gastric fistula rat, both the antiulcerogens bromocriptine or lergotrile and the proulcerogens haloperidol, pimozide or (-)-N-(2-chlorethyl)-norapomorphine decreased the cysteamine- or propionitrile-induced gastric secretion. No correlation was apparent between the influence of these drugs on duodenal ulcer development and gastric and duodenal (pancreatic/biliary) secretions. In the chronic duodenal fistula rat, decreased acid content was measured in the proximal duodenum after haloperidol, and diminished duodenal pepsin exposure was recorded after bromocriptine. Furthermore, the aggravation by dopamine antagonists of experimental duodenal ulcer probably involves a peripheral component. The site of dopamine receptors and physiologic effects which modulate experimental duodenal ulcer remain to be identified, but their elucidation may prove to be an important element in the pathogenesis and treatment of duodenal ulcer.

  18. [Obesity and gastrointestinal motility].

    PubMed

    Lee, Joon Seong

    2006-08-01

    Gastrointestinal (GI) motility has a crucial role in the food consumption, digestion and absorption, and also controls the appetite and satiety. In obese patients, various alterations of GI motility have been investigated. The prevalence of GERD and esophageal motor disorders in obese patients are higher than those of general population. Gastric emptying of solid food is generally accelerated and fasting gastric volume especially in distal stomach is larger in obese patients without change in accommodation. Contractile activity of small intestine in fasting period is more prominent, but orocecal transit is delayed. Autonomic dysfunction is frequently demonstrated in obese patients. These findings correspond with increased appetite and delayed satiety in obese patients, but causes or results have not been confirmed. Therapeutic interventions of these altered GI motility have been developed using botulinum toxin, gastric electrical stimulation in obese patients. Novel agents targeted for GI hormone modulation (such as ghrelin and leptin) need to be developed in the near future. PMID:16929152

  19. Approaches to gastrointestinal cytoprotection: from isolated cells, via animal experiments to healthy human subjects and patients with different gastrointestinal disorders.

    PubMed

    Mózsik, Gyula; Szabó, Imre L; Czimmer, József

    2011-01-01

    Our clinical observations proved that the the duodenal ulcer in patients healed without any inhibition of gastric acid secretion (1965), and the healing rates of atropine vs cimetidine vs Carbenoxolone were equal and superior to that of placebo in randomized, prospective and multiclinical study of DU patients (1978). The phenomenon of gastric cytoprotection was defined by André Robert in rats (1979). The essential point of this phenomenon is that the prostaglandins prevent the chemical-induced gastric mucosal damage without affecting gastric acid secretion, this being originally suggested as a reaction specific to prostaglandins. Since then gastrointestinal cytoprotection has been shown with various agents (anticholinergic agents, H(2)RA, growth factors, body protecting compound, BPC) and retinoids in animals; the latter differing from the actions of vitamin A. In examining the various components of gastrointestinal cytoprotection , different studies have performed in isolated cells, stable cell lines, animal experiments, healthy human subjects, in patients chronic gastric and duodenal ulcers, and with different gastrointestinal disorders. Our attention has focused on the effects of cytoprotective agents on cellular viability, mitochondrial and DNA damage, oxygen free radicals, natural antioxidant systems, mucosal biochemistry, vascular events, gastrointestinal mucosal protection as well as in their prevention of different human diseases. This paper gives an overview on the different approaches for the exploring gastrointestinal cytoprotection (at the level of isolated cells, animal experiments, healthy human beings and patients with different gastrointestinal disorders). It has been indicated that the gastric cytoprotection exists in animals, human healthy subjects, patients with different gastrointestinal disorders. The our human observation in patients with duodenal ulcer healed without any changes of gastric acid secretion, there were no significant

  20. Disorders of gastrointestinal hypomotility

    PubMed Central

    Bielefeldt, Klaus; Tuteja, Ashok; Nusrat, Salman

    2016-01-01

    Ingestion and digestion of food as well as expulsion of residual material from our gastrointestinal tract requires normal propulsive, i.e. motor, function. Hypomotility refers to inherited or acquired changes that come with decreased contractile forces or slower transit. It not only often causes symptoms but also may compromise nutritional status or lead to other complications. While severe forms, such as pseudo-obstruction or ileus, may have a tremendous functional impact, the less severe forms of hypomotility may well be more relevant, as they contribute to common disorders, such as functional dyspepsia, gastroparesis, chronic constipation, and irritable bowel syndrome (IBS). Clinical testing can identify changes in contractile activity, defined by lower amplitudes or abnormal patterns, and the related effects on transit. However, such biomarkers show a limited correlation with overall symptom severity as experienced by patients. Similarly, targeting hypomotility with pharmacological interventions often alters gut motor function but does not consistently improve symptoms. Novel diagnostic approaches may change this apparent paradox and enable us to obtain more comprehensive information by integrating data on electrical activity, mechanical forces, patterns, wall stiffness, and motions with information of the flow of luminal contents. New drugs with more selective effects or more specific delivery may improve benefits and limit adverse effects. Lastly, the complex regulation of gastrointestinal motility involves the brain-gut axis as a reciprocal pathway for afferent and efferent signaling. Considering the role of visceral input in emotion and the effects of emotion on visceral activity, understanding and managing hypomotility disorders requires an integrative approach based on the mind-body continuum or biopsychosocial model of diseases. PMID:27583135

  1. Disorders of gastrointestinal hypomotility.

    PubMed

    Bielefeldt, Klaus; Tuteja, Ashok; Nusrat, Salman

    2016-01-01

    Ingestion and digestion of food as well as expulsion of residual material from our gastrointestinal tract requires normal propulsive, i.e. motor, function. Hypomotility refers to inherited or acquired changes that come with decreased contractile forces or slower transit. It not only often causes symptoms but also may compromise nutritional status or lead to other complications. While severe forms, such as pseudo-obstruction or ileus, may have a tremendous functional impact, the less severe forms of hypomotility may well be more relevant, as they contribute to common disorders, such as functional dyspepsia, gastroparesis, chronic constipation, and irritable bowel syndrome (IBS). Clinical testing can identify changes in contractile activity, defined by lower amplitudes or abnormal patterns, and the related effects on transit. However, such biomarkers show a limited correlation with overall symptom severity as experienced by patients. Similarly, targeting hypomotility with pharmacological interventions often alters gut motor function but does not consistently improve symptoms. Novel diagnostic approaches may change this apparent paradox and enable us to obtain more comprehensive information by integrating data on electrical activity, mechanical forces, patterns, wall stiffness, and motions with information of the flow of luminal contents. New drugs with more selective effects or more specific delivery may improve benefits and limit adverse effects. Lastly, the complex regulation of gastrointestinal motility involves the brain-gut axis as a reciprocal pathway for afferent and efferent signaling. Considering the role of visceral input in emotion and the effects of emotion on visceral activity, understanding and managing hypomotility disorders requires an integrative approach based on the mind-body continuum or biopsychosocial model of diseases. PMID:27583135

  2. Casimir microsphere diclusters and three-body effects in fluids

    SciTech Connect

    Varela, Jaime; McCauley, Alexander P.; Rodriguez, Alejandro W.; Johnson, Steven G.

    2011-04-15

    Our previous paper [Phys. Rev. Lett. 104, 060401 (2010)] predicted that Casimir forces induced by the material-dispersion properties of certain dielectrics can give rise to stable configurations of objects. This phenomenon was illustrated via a dicluster configuration of nontouching objects consisting of two spheres immersed in a fluid and suspended against gravity above a plate. Here, we examine these predictions from the perspective of a practical experiment and consider the influence of nonadditive, three-body, and nonzero-temperature effects on the stability of the two spheres. We conclude that the presence of Brownian motion reduces the set of experimentally realizable silicon-teflon spherical diclusters to those consisting of layered microspheres, such as the hollow core (spherical shells) considered here.

  3. Preparation and evaluation of sustained release loxoprofen loaded microspheres

    PubMed Central

    Venkatesan, P.; Manavalan, R.; Valliappan, K.

    2011-01-01

    The aim of present study was to formulate and evaluate the loxoprofen loaded Sustained release microspheres by emulsion solvent evaporation technique. Ethylcellulose, a biocompatible polymer is used as the retardant material. The effects of process conditions such as drug loading, polymer type and solvent type on the characteristics of microspheres were investigated. The prepared microspheres were characterized for their particle size and drug loading and drug release. The in-vitro release studies were carried out in phosphate buffer at pH 7.4. The prepared microspheres were white, free flowing and spherical in shape. The drug-loaded microspheres showed 71.2% of entrapment and the in-vitro release studies showed that Loxoprofen microspheres of 1:3 ratios showed better sustained effect over a period of 8 hours PMID:24826017

  4. Method of detecting luminescent target ions with modified magnetic microspheres

    DOEpatents

    Shkrob, Ilya A; Kaminski, Michael D

    2014-05-13

    This invention provides methods of using modified magnetic microspheres to extract target ions from a sample in order to detect their presence in a microfluidic environment. In one or more embodiments, the microspheres are modified with molecules on the surface that allow the target ions in the sample to form complexes with specific ligand molecules on the microsphere surface. In one or more embodiments, the microspheres are modified with molecules that sequester the target ions from the sample, but specific ligand molecules in solution subsequently re-extract the target ions from the microspheres into the solution, where the complexes form independent of the microsphere surface. Once the complexes form, they are exposed to an excitation wavelength light source suitable for exciting the target ion to emit a luminescent signal pattern. Detection of the luminescent signal pattern allows for determination of the presence of the target ions in the sample.

  5. Optically Levitated Microspheres as a Probe for New Interactions

    NASA Astrophysics Data System (ADS)

    Rider, Alexander; Moore, David; Blakemore, Charles; Lu, Marie; Gratta, Giorgio

    2016-03-01

    We are developing novel techniques to probe new interactions at micron distances using optically levitated dielectric microspheres. Levitated microspheres are an ideal probe for short-range interactions because they are suspended using the radiation pressure at the focus of a laser beam, which means that the microspheres can be precisely manipulated and isolated from the surrounding environment at high vacuum. We have performed a search for unknown charged particles bound within the bulk of the microspheres. Currently, we are searching for the presence of a Chameleon field postulated to explain the presence of dark energy in the universe. In the future we plan to use optically levitated microspheres to search for micron length-scale gravity like interactions that could couple between a microsphere and another mass. We will present resent results from these experiments and plans for future searches for new interactions.

  6. Multiple-dose therapy with bovine colostrum confers significant protection against diarrhea in a mouse model of human rotavirus-induced gastrointestinal disease.

    PubMed

    Inagaki, M; Yamamoto, M; Cairangzhuoma; Xijier; Yabe, T; Uchida, K; Kawasaki, M; Nakagomi, T; Nakagomi, O; Minamoto, N; Kanamaru, Y

    2013-02-01

    Rotavirus is the most important etiologic agent of severe gastroenteritis. Previously, we reported that skimmed and concentrated bovine late colostrum (SCBLC) obtained from normal unimmunized cows at 6 to 7d after parturition effectively prevented against human rotavirus (HRV)-induced severe gastroenteritis in vivo, when administered as a single dose 60 min before viral inoculation. In the present study, we examined the efficacy of multiple administrations of SCBLC at smaller dosages after viral inoculation in vivo. We demonstrate that multiple administrations within 24h after virus inoculation resulted in earlier recovery from diarrheal symptoms, in an administration frequency-dependent manner. Furthermore, we investigated whether isolated IgG anti-HRV activity in SCBLC was equivalent to that of IgG isolated from bovine mature milk as measured by in vitro activity assays. We found that IgG-containing fractions from SCBLC and mature milk exhibited approximately the same level of anti-HRV activity. We concluded that the SCBLC contains a high level of IgG against HRV-induced severe gastroenteritis, which will be possible to use in protective effects in immunocompromised hosts, such as children and the elderly. Multiple doses of SCBLC during the early stages of infection or lower dosage of SCBLC given as a single dose both resulted in relief of diarrheal symptoms. PMID:23200479

  7. Microencapsulation of bacteriophage felix O1 into chitosan-alginate microspheres for oral delivery.

    PubMed

    Ma, Yongsheng; Pacan, Jennifer C; Wang, Qi; Xu, Yongping; Huang, Xiaoqing; Korenevsky, Anton; Sabour, Parviz M

    2008-08-01

    This paper reports the development of microencapsulated bacteriophage Felix O1 for oral delivery using a chitosan-alginate-CaCl(2) system. In vitro studies were used to determine the effects of simulated gastric fluid (SGF) and bile salts on the viability of free and encapsulated phage. Free phage Felix O1 was found to be extremely sensitive to acidic environments and was not detectable after a 5-min exposure to pHs below 3.7. In contrast, the number of microencapsulated phage decreased by 0.67 log units only, even at pH 2.4, for the same period of incubation. The viable count of microencapsulated phage decreased only 2.58 log units during a 1-h exposure to SGF with pepsin at pH 2.4. After 3 h of incubation in 1 and 2% bile solutions, the free phage count decreased by 1.29 and 1.67 log units, respectively, while the viability of encapsulated phage was fully maintained. Encapsulated phage was completely released from the microspheres upon exposure to simulated intestinal fluid (pH 6.8) within 6 h. The encapsulated phage in wet microspheres retained full viability when stored at 4 degrees C for the duration of the testing period (6 weeks). With the use of trehalose as a stabilizing agent, the microencapsulated phage in dried form had a 12.6% survival rate after storage for 6 weeks. The current encapsulation technique enables a large proportion of bacteriophage Felix O1 to remain bioactive in a simulated gastrointestinal tract environment, which indicates that these microspheres may facilitate delivery of therapeutic phage to the gut. PMID:18515488

  8. Beat frequency ultrasonic microsphere contrast agent detection system

    NASA Technical Reports Server (NTRS)

    Pretlow, III, Robert A. (Inventor); Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    1997-01-01

    A system for and method of detecting and measuring concentrations of an ultrasonically-reflective microsphere contrast agent involving detecting non-linear sum and difference beat frequencies produced by the microspheres when two impinging signals with non-identical frequencies are combined by mixing. These beat frequencies can be used for a variety of applications such as detecting the presence of and measuring the flow rates of biological fluids and industrial liquids, including determining the concentration level of microspheres in the myocardium.

  9. (D, L) polylactide microspheres as embolic agent. A preliminary study.

    PubMed

    Flandroy, P; Grandfils, C; Collignon, J; Thibaut, A; Nihant, N; Barbette, S; Jerome, R; Teyssie, P

    1990-01-01

    Owing to their shape, accurately calibrated microspheres appear to be very suitable material for distal embolization. Moreover, the biocompatible (D, L) polyactide (PLA) microspheres possess two other valuable advantages: easy adjustment of their biodegradation rate, and incorporation of chemotherapeutic agents during their production. The authors describe the preparation of these (D, L) PLA microspheres and their clinical applications as a preliminary step to arterial chemoembolization. PMID:2234391

  10. A Radically New Method for Hydrogen Storage in Hollow Glass Microspheres

    SciTech Connect

    James E. Shelby; Matthew M. Hall; Fabienne C. Raszewski

    2007-08-31

    Photo-induced hydrogen diffusion has been applied to the problem of storage of high pressure hydrogen in hollow glass microspheres. Results of this study indicate that this phenomenon can be used to provide a high mass efficiency, safe, cheap, non-toxic method for storage of high pressure hydrogen. The photo-induced response is immediate upon exposure to infrared light for hollow glass microspheres doped with iron, nickel, or cobalt oxide, which is consistent with previous results for transition metal oxide-doped bulk glass samples. This effect is not observed for HGMS which do not contain these transition metal oxide, where the slight release of hydrogen observed occurs only by heating from absorption of the light. The initial rate of hydrogen release increases with increasing concentration of the metal oxide and with increasing hydrogen fill pressure within the microspheres. To date, hydrogen storage efficiencies of 2.2 wt% have been obtained, but results suggest that storage values can be increased to at least 6 wt%. Hydrogen losses over a 5 week period are minimal at room temperature in all compositions, with somewhat greater, but acceptable, losses at 50 C. Hollow glass microspheres have been produced from an alkali alkaline earth borosilicate glass containing either 1 or 5 wt% of the oxides of iron, nickel, and cobalt. Photo-driven gas diffusion has been demonstrated for these HGMS. Demonstration of photo-induced diffusion in these samples provides the first proof-of-concept for eventual applications of HGMS for large scale hydrogen storage.

  11. Low threshold lasing of bubble-containing glass microspheres by non-whispering gallery mode excitation over a wide wavelength range

    SciTech Connect

    Kumagai, Tsutaru Kishi, Tetsuo; Yano, Tetsuji

    2015-03-21

    Bubble-containing Nd{sup 3+}-doped tellurite glass microspheres were fabricated by localized laser heating technique to investigate their optical properties for use as microresonators. Fluorescence and excitation spectra measurements were performed by pumping with a tunable CW-Ti:Sapphire laser. The excitation spectra manifested several sharp peaks due to the conventional whispering gallery mode (WGM) when the pumping laser was irradiated to the edge part of the microsphere. However, when the excitation light was irradiated on the bubble position inside the microsphere, “non-WGM excitation” was induced, giving rise to numerous peaks at a broad wavelength range in the excitation spectra. Thus, efficient excitation was achieved over a wide wavelength range. Lasing threshold excited at the bubble position was much lower than that for the excitation at the edges of the microsphere. The lowest value of the laser threshold was 34 μW for a 4 μm sphere containing a 0.5 μm bubble. Efficiency of the excitation at the bubble position with broadband light was calculated to be 5 times higher than that for the edge of the microsphere. The bubble-containing microsphere enables efficient utilization of broadband light excitation from light-emitting diodes and solar light.

  12. A new approach for the one-step synthesis of bioactive PS vs. PMMA silica hybrid microspheres as potential drug delivery systems.

    PubMed

    Angelopoulou, A; Efthimiadou, E K; Boukos, N; Kordas, G

    2014-05-01

    In this work, hybrid microspheres were prepared in a two-step process combining the emulsifier free-emulsion polymerization and the sol-gel coating method. In the first step, polystyrene (St) and poly(methyl methacrylate) (PMMA) microspheres were prepared as sacrificial template and in the second step a silanol shell was fabricated. The functionalized surface of the hybrid microspheres by silane analogs (APTES, TEOS) resulted in enhanced effects. The hollow microspheres were resulted either in an additional step by template dissolution and/or during the coating process. The microspheres' surface interactions and the size distribution were optimized by treatment in simulated body fluids, which resulted in the in vitro prediction of bioactivity. The bioassay test indicated that the induced hydroxyapatite resembled in structure to naturally occurring bone apatite. The drug doxorubicin (DOX) was used as a model entity for the evaluation of drug loading and release. The drug release study was performed in two different pH conditions, at acidic (pH=4.5) close to cancer cell environment and at slightly basic pH (pH=7.4) resembling the orthopedic environment. The results of the present study indicated promising hybrid microspheres for the potential application as drug delivery vehicles, for dual orthopedic functionalities in bone defects, bone inflammation, bone cancer and bone repair.

  13. Preparation of uniform magnetic recoverable catalyst microspheres with hierarchically mesoporous structure by using porous polymer microsphere template

    PubMed Central

    2014-01-01

    Merging nanoparticles with different functions into a single microsphere can exhibit profound impact on various applications. However, retaining the unique properties of each component after integration has proven to be a significant challenge. Our previous research demonstrated a facile method to incorporate magnetic nanoparticles into porous silica microspheres. Here, we report the fabrication of porous silica microspheres embedded with magnetic and gold nanoparticles as magnetic recoverable catalysts. The as-prepared multifunctional composite microspheres exhibit excellent magnetic and catalytic properties and a well-defined structure such as uniform size, high surface area, and large pore volume. As a result, the very little composite microspheres show high performance in catalytic reduction of 4-nitrophenol, special convenient magnetic separability, long life, and good reusability. The unique nanostructure makes the microspheres a novel stable and highly efficient catalyst system for various catalytic industry processes. PMID:24708885

  14. Preparation of porous zirconia microspheres by internal gelation method

    SciTech Connect

    Pathak, Sachin S.; Pius, I.C. Bhanushali, R.D.; Rao, T.V. Vittal; Mukerjee, S.K.

    2008-11-03

    A modified internal gelation process for the preparation of porous zirconia microspheres has been developed. The conventional method has been modified by adding a surfactant in the feed broth. The effects of variation of surfactant concentration, washing techniques and temperature of calcination on the pore volume and the surface area of the microspheres have been studied. The conditions were optimized to obtain porous stable microspheres suitable for various applications. The microspheres were characterized by surface area analysis, pore volume analysis, thermogravimetric analysis and X-ray diffraction. The ion exchange behavior was studied using pH titration.

  15. Fluorescent Microspheres as Point Sources: A Localization Study.

    PubMed

    Chao, Jerry; Lee, Taiyoon; Ward, E Sally; Ober, Raimund J

    2015-01-01

    The localization of fluorescent microspheres is often employed for drift correction and image registration in single molecule microscopy, and is commonly carried out by fitting a point spread function to the image of the given microsphere. The mismatch between the point spread function and the image of the microsphere, however, calls into question the suitability of this localization approach. To investigate this issue, we subject both simulated and experimental microsphere image data to a maximum likelihood estimator that localizes a microsphere by fitting an Airy pattern to its image, and assess the suitability of the approach by evaluating the ability of the estimator to recover the true location of the microsphere with the best possible accuracy as determined based on the Cramér-Rao lower bound. Assessing against criteria based on the standard errors of the mean and the variance for an ideal estimator of the microsphere's location, we find that microspheres up to 100 nm in diameter can in general be localized using a fixed width Airy pattern, and that microspheres as large as 1 μm in diameter can in general be localized using a floated width Airy pattern. PMID:26218251

  16. Chitosan microspheres as a delivery system for nasal insufflation.

    PubMed

    Patil, Sanjay B; Sawant, Krutika K

    2011-06-01

    The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres for nasal delivery. The microspheres were prepared by emulsification-crosslinking method and evaluated for morphology, particle size, swelling index, in vitro mucoadhesion and delivery properties from Miat(®) nasal insufflator. The results showed that the microspheres were spherical in shape with smooth surfaces. The particle size of microspheres was found to be dependent on the concentration of the chitosan. The mean particle size was significantly increased when high concentration of chitosan was used. Aqueous to oil phase ratio, stirring rate and dioctyl sodium sulfosuccinate (DOSS) concentration also influenced the particle size distribution of the microspheres. It was found that, as stirring rate was increased, the size of the microspheres was decreased. The volume of glutaraldehyde and crosslinking time had very slight effect on particle size distribution. The % equilibrium water uptake of the microspheres was ranged from 124% to 232% and the mucoadhesive strength from 70.64±2.14 to 86.32±3.96%. The results of powder delivery from the device showed that, almost entire amount was delivered after three puffs. The images of the delivery sequences of microsphere powder clouds demonstrated that microspheres were delivered forming an elongated puff. The core of the clouds was homogeneous which can be expected to provide effective distribution pattern.

  17. The xanthene dyes doped PMMA microspheres for optical sensor applications

    NASA Astrophysics Data System (ADS)

    Miluski, Piotr; Dorosz, Dominik; Kochanowicz, Marcin; Zmojda, Jacek; Dorosz, Jan

    2015-12-01

    The numerous applications of luminescent glass and polymeric microspheres are well known. The polymeric structures are popular as they assure good processability (solid and porous structures) and high doping level. The article presents the suspension polymerization process of polymeric (PMMA) microspheres doped by xanthene dyes: Fluorescein (Fl) and Rhodamine B (RhB). The bright luminescence at wavelengths 510nm 595nm respectively was recorded. The shape and dimension distributions of fabricated microspheres were optically determined. The article presents also potential applications of fabricated luminescent microspheres.

  18. Fiber optic chemical microsensors employing optically active silica microspheres

    NASA Astrophysics Data System (ADS)

    Pope, Edward J. A.

    1995-05-01

    Dye-doped porous silica microspheres can be prepared from liquid solution at temperatures near ambient. Microsphere diameter can be controlled between approximately 5.0 microns to in excess of a millimeter. The resulting microspheres can be attached to the distal end of an optical fiber in which the proximal end is attached to a spectrophotometer. Depending upon the organic species doped into the microsphere, a wide variety of sensing functions are possible. In this paper, the use of microsensors for measuring pH, temperature, and solvent content of aqueous solutions is demonstrated. Potential utility of this type of sensor to heavy metals detection and biomedical diagnostics is also discussed.

  19. Properties of poly(styrene/alpha-tert-butoxy-omega-vinylbenzyl-polyglycidol) microspheres suspended in water. Effect of sodium chloride and temperature on particle diameters and electrophoretic mobility.

    PubMed

    Basinska, Teresa; Slomkowski, Stanislaw; Kazmierski, Slawomir; Chehimi, Mohamed M

    2008-08-19

    Hydrodynamic and electrophoretic properties of core-shell poly(styrene/alpha- tert-butoxy-omega-vinylbenzyl-polyglycidol) (P(S/PGL)) microspheres suspended in water are described. The microspheres were obtained by surfactant-free emulsion copolymerization of styrene and alpha- tert-butoxy-omega-vinylbenzyl-polyglycidol macromonomer ( M n = 2800, M w/ M n = 1.05). The process yielded microspheres with number average diameter D n = 270 nm and with low diameter dispersity index D w/ D n = 1.01. Shells of P(S/PGL) microspheres were enriched in polyglycidol. Molar fraction of polyglycidol monomeric units in the shells (determined by X-ray photoelectron spectroscopy) was equal to 0.34, which is much higher than the average molar fraction of polyglycidol monomeric units in whole particles of 0.048. Influences of NaCl concentration and temperature on P(S/PGL) microsphere diameters and on their electrophoretic mobility were investigated. It was found that hydrodynamic diameter of P(S/PGL) microspheres, determined by photon correlation spectroscopy, decreased significantly when temperature did exceed a certain value (transition temperature, T t). It has been found that the decrease is more pronounced for higher concentrations of NaCl in the medium. For microspheres suspended in 10 (-1) M NaCl, the hydrodynamic diameter decreased by 8% whereas for the same particles in pure water the diameter decreased by 5.2%. The process of shrinkage was fully reversible. Values of T t for P(S/PGL) microspheres were lower for higher concentrations of NaCl. Adjustment of salt concentration allowed controlling T t in a range from 44.4 to 49.9 degrees C. 13C NMR relaxation time measurements (T 1) for carbon atoms in polyglycidol macromonomer revealed that T 1 did increase with increasing temperature (in temperature range from 25 to 75 degrees C) indicating higher motion of chains at higher temperature. Addition of NaCl did not induce a substantial change of T 1 in the mentioned temperature

  20. The effects of acute oral glutamine supplementation on exercise-induced gastrointestinal permeability and heat shock protein expression in peripheral blood mononuclear cells.

    PubMed

    Zuhl, Micah; Dokladny, Karol; Mermier, Christine; Schneider, Suzanne; Salgado, Roy; Moseley, Pope

    2015-01-01

    Chronic glutamine supplementation reduces exercise-induced intestinal permeability and inhibits the NF-κB pro-inflammatory pathway in human peripheral blood mononuclear cells. These effects were correlated with activation of HSP70. The purpose of this paper is to test if an acute dose of oral glutamine prior to exercise reduces intestinal permeability along with activation of the heat shock response leading to inhibition of pro-inflammatory markers. Physically active subjects (N = 7) completed baseline and exercise intestinal permeability tests, determined by the percent ratio of urinary lactulose (5 g) to rhamnose (2 g). Exercise included two 60-min treadmill runs at 70 % of VO2max at 30 °C after ingestion of glutamine (Gln) or placebo (Pla). Plasma levels of endotoxin and TNF-α, along with peripheral blood mononuclear cell (PBMC) protein expression of HSP70 and IκBα, were measured pre- and post-exercise and 2 and 4 h post-exercise. Permeability increased in the Pla trial compared to that at rest (0.06 ± 0.01 vs. 0.02 ± 0.018) and did not increase in the Gln trial. Plasma endotoxin was lower at the 4-h time point in the Gln vs. 4 h in the Pla (6.715 ± 0.046 pg/ml vs. 7.952 ± 1.11 pg/ml). TNF-α was lower 4 h post-exercise in the Gln vs. Pla (1.64 ± 0.09 pg/ml vs. 1.87 ± 0.12 pg/ml). PBMC expression of IkBα was higher 4 h post-exercise in the Gln vs. 4 h in the Pla (1.29 ± 0.43 vs. 0.8892 ± 0.040). HSP70 was higher pre-exercise and 2 h post-exercise in the Gln vs. Pla (1.35 ± 0.21 vs. 1.000 ± 0.000 and 1.65 ± 0.21 vs. 1.27 ± 0.40). Acute oral glutamine supplementation prevents an exercise-induced rise in intestinal permeability and suppresses NF-κB activation in peripheral blood mononuclear cells. PMID:25062931

  1. The effects of acute oral glutamine supplementation on exercise-induced gastrointestinal permeability and heat shock protein expression in peripheral blood mononuclear cells.

    PubMed

    Zuhl, Micah; Dokladny, Karol; Mermier, Christine; Schneider, Suzanne; Salgado, Roy; Moseley, Pope

    2015-01-01

    Chronic glutamine supplementation reduces exercise-induced intestinal permeability and inhibits the NF-κB pro-inflammatory pathway in human peripheral blood mononuclear cells. These effects were correlated with activation of HSP70. The purpose of this paper is to test if an acute dose of oral glutamine prior to exercise reduces intestinal permeability along with activation of the heat shock response leading to inhibition of pro-inflammatory markers. Physically active subjects (N = 7) completed baseline and exercise intestinal permeability tests, determined by the percent ratio of urinary lactulose (5 g) to rhamnose (2 g). Exercise included two 60-min treadmill runs at 70 % of VO2max at 30 °C after ingestion of glutamine (Gln) or placebo (Pla). Plasma levels of endotoxin and TNF-α, along with peripheral blood mononuclear cell (PBMC) protein expression of HSP70 and IκBα, were measured pre- and post-exercise and 2 and 4 h post-exercise. Permeability increased in the Pla trial compared to that at rest (0.06 ± 0.01 vs. 0.02 ± 0.018) and did not increase in the Gln trial. Plasma endotoxin was lower at the 4-h time point in the Gln vs. 4 h in the Pla (6.715 ± 0.046 pg/ml vs. 7.952 ± 1.11 pg/ml). TNF-α was lower 4 h post-exercise in the Gln vs. Pla (1.64 ± 0.09 pg/ml vs. 1.87 ± 0.12 pg/ml). PBMC expression of IkBα was higher 4 h post-exercise in the Gln vs. 4 h in the Pla (1.29 ± 0.43 vs. 0.8892 ± 0.040). HSP70 was higher pre-exercise and 2 h post-exercise in the Gln vs. Pla (1.35 ± 0.21 vs. 1.000 ± 0.000 and 1.65 ± 0.21 vs. 1.27 ± 0.40). Acute oral glutamine supplementation prevents an exercise-induced rise in intestinal permeability and suppresses NF-κB activation in peripheral blood mononuclear cells.

  2. Sleep Dysfunction and Gastrointestinal Diseases.

    PubMed

    Khanijow, Vikesh; Prakash, Pia; Emsellem, Helene A; Borum, Marie L; Doman, David B

    2015-12-01

    Sleep deprivation and impaired sleep quality have been associated with poor health outcomes. Many patients experience sleep disturbances, which can increase the risk of medical conditions such as hypertension, obesity, stroke, and heart disease as well as increase overall mortality. Recent studies have suggested that there is a strong association between sleep disturbances and gastrointestinal diseases. Proinflammatory cytokines, such as tumor necrosis factor, interleukin-1, and interleukin-6, have been associated with sleep dysfunction. Alterations in these cytokines have been seen in certain gastrointestinal diseases, such as gastroesophageal reflux disease, inflammatory bowel disease, liver disorders, and colorectal cancer. It is important for gastroenterologists to be aware of the relationship between sleep disorders and gastrointestinal illnesses to ensure good care for patients. This article reviews the current research on the interplay between sleep disorders, immune function, and gastrointestinal diseases. PMID:27134599

  3. Gastrointestinal Motility Disorders in Children

    PubMed Central

    Ambartsumyan, Lusine

    2014-01-01

    The most common and challenging gastrointestinal motility disorders in children include gastroesophageal reflux disease (GERD), esophageal achalasia, gastroparesis, chronic intestinal pseudo-obstruction, and constipation. GERD is the most common gastrointestinal motility disorder affecting children and is diagnosed clinically and treated primarily with acid secretion blockade. Esophageal achalasia, a less common disorder in the pediatric patient population, is characterized by dysphagia and treated with pneumatic balloon dilation and/or esophagomyotomy. Gastroparesis and chronic intestinal pseudo-obstruction are poorly characterized in children and are associated with significant morbidity. Constipation is among the most common complaints in children and is associated with significant morbidity as well as poor quality of life. Data on epidemiology and outcomes, clinical trials, and evaluation of new diagnostic techniques are needed to better diagnose and treat gastrointestinal motility disorders in children. We present a review of the conditions and challenges related to these common gastrointestinal motility disorders in children. PMID:24799835

  4. Sleep Dysfunction and Gastrointestinal Diseases

    PubMed Central

    Khanijow, Vikesh; Prakash, Pia; Emsellem, Helene A.; Borum, Marie L.

    2015-01-01

    Sleep deprivation and impaired sleep quality have been associated with poor health outcomes. Many patients experience sleep disturbances, which can increase the risk of medical conditions such as hypertension, obesity, stroke, and heart disease as well as increase overall mortality. Recent studies have suggested that there is a strong association between sleep disturbances and gastrointestinal diseases. Proinflammatory cytokines, such as tumor necrosis factor, interleukin-1, and interleukin-6, have been associated with sleep dysfunction. Alterations in these cytokines have been seen in certain gastrointestinal diseases, such as gastroesophageal reflux disease, inflammatory bowel disease, liver disorders, and colorectal cancer. It is important for gastroenterologists to be aware of the relationship between sleep disorders and gastrointestinal illnesses to ensure good care for patients. This article reviews the current research on the interplay between sleep disorders, immune function, and gastrointestinal diseases. PMID:27134599

  5. Implication of combined PD-L1/PD-1 blockade with cytokine-induced killer cells as a synergistic immunotherapy for gastrointestinal cancer.

    PubMed

    Dai, Congqi; Lin, Fengjuan; Geng, Ruixuan; Ge, Xiaoxiao; Tang, Wenbo; Chang, Jinjia; Wu, Zheng; Liu, Xinyang; Lin, Ying; Zhang, Zhe; Li, Jin

    2016-03-01

    Cytokine-induced killer (CIK) cells represent a realistic approach in cancer immunotherapy with confirmed survival benefits in the context of metastatic solid tumors. However, therapeutic effects are limited to a fraction of patients. In this study, immune-resistance elements and ideal combination therapies were explored. Initially, phenotypic analysis was performed to document CD3, CD56, NKG2D, DNAM-1, PD-L1, PD-1, CTLA-4, TIM-3, 2B4, and LAG-3 on CIK cells. Upon engagement of CIK cells with the tumor cells, expression of PD-1 on CIK cells and PD-L1 on both cells were up-regulated. Over-expression of PD-L1 levels on tumor cells via lentiviral transduction inhibited tumoricidal activity of CIK cells, and neutralizing of PD-L1/PD-1 signaling axis could enhance their tumor-killing effect. Conversely, blockade of NKG2D, a major activating receptor of CIK cells, largely caused dysfunction of CIK cells. Functional study showed an increase of NKG2D levels along with PD-L1/PD-1 blockade in the presence of other immune effector molecule secretion. Additionally, combined therapy of CIK infusion and PD-L1/PD-1 blockade caused a delay of in vivo tumor growth and exhibited a survival advantage over untreated mice. These results provide a preclinical proof-of-concept for simultaneous PD-L1/PD-1 pathways blockade along with CIK infusion as a novel immunotherapy for unresectable cancers.

  6. The chicken gastrointestinal microbiome.

    PubMed

    Oakley, Brian B; Lillehoj, Hyun S; Kogut, Michael H; Kim, Woo K; Maurer, John J; Pedroso, Adriana; Lee, Margie D; Collett, Stephen R; Johnson, Timothy J; Cox, Nelson A

    2014-11-01

    The domestic chicken is a common model organism for human biological research and of course also forms the basis of a global protein industry. Recent methodological advances have spurred the recognition of microbiomes as complex communities with important influences on the health and disease status of the host. In this minireview, we provide an overview of the current state of knowledge of the chicken gastrointestinal microbiome focusing on spatial and temporal variability, the presence and importance of human pathogens, the influence of the microbiota on the immune system, and the importance of the microbiome for poultry nutrition. Review and meta-analysis of public data showed cecal communities dominated by Firmicutes and Bacteroides at the phylum level, while at finer levels of taxonomic resolution, a phylogenetically diverse assemblage of microorganisms appears to have similar metabolic functions that provide important benefits to the host as inferred from metagenomic data. This observation of functional redundancy may have important implications for management of the microbiome. We foresee advances in strategies to improve gut health in commercial operations through management of the intestinal microbiota as an alternative to in-feed subtherapeutic antibiotics, improvements in pre- and probiotics, improved management of polymicrobial poultry diseases, and better control of human pathogens via colonization reduction or competitive exclusion strategies. PMID:25263745

  7. Thalidomide in gastrointestinal disorders.

    PubMed

    Bousvaros, A; Mueller, B

    2001-01-01

    Thalidomide was originally marketed as a sedative, but was removed from the market in 1961 after it was associated with an epidemic of severe birth defects. Subsequently, it has been shown to have therapeutic efficacy in a number of the gastrointestinal tract conditions characterised by immune dysregulation. The exact mechanism of the immunosuppressive effects of thalidomide is unknown; proposed mechanisms include inhibition of tumour necrosis factor alpha release and inhibition of angiogenesis. In chronic graft versus host disease, use of high dose thalidomide (1200 mg/day) may bring about a response in 20% of patients with refractory disease. Thalidomide 200 mg/day helps eradicate ulcers in 50% of patients with HIV-associated oral aphthous ulceration. In Behçet's disease, thalidomide 100 to 300 mg/day can decrease the number of mucocutaneous ulcers, although full remission occurs in less than 20% of patients. In Crohn's disease, thalidomide 50 to 300 mg/day may decrease the severity of mucosal disease and prompt closure of fistulae. Patients to be placed on thalidomide therapy must practice either abstinence or strict birth control; women must undergo regular pregnancy testing and utilise 2 forms of contraception. Other adverse effects include sedation (present in nearly all patients), symptomatic neuropathy (present in approximately 20%), and skin rashes. Given the potential toxicity, thalidomide use should generally be limited to clinical protocols with institutional review board oversight.

  8. Feline gastrointestinal microbiota.

    PubMed

    Minamoto, Yasushi; Hooda, Seema; Swanson, Kelly S; Suchodolski, Jan S

    2012-06-01

    The close relationship between gastrointestinal (GI) microbiota and its host has an impact on the health status of an animal that reaches beyond the GI tract. A balanced microbiome stimulates the immune system, aids in the competitive exclusion of transient pathogens and provides nutritional benefits to the host. With recent rapid advances in high-throughput sequencing technology, molecular approaches have become the routinely used tools for ecological studies of the feline microbiome, and have revealed a highly diverse and complex intestinal ecosystem in the feline GI tract. The major bacterial groups are similar to those found in other mammals, with Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria constituting more than 99% of intestinal microbiota. Several nutritional studies have demonstrated that the feline microbiota can be modulated by the amount of soluble fibers (i.e., prebiotics) and macronutrients (i.e., protein content) in the diet. Initial clinical studies have suggested the presence of a dysbiosis in feline inflammatory bowel disease (IBD). Recently, metagenomic approaches have attempted to characterize the microbial gene pool. However, more studies are needed to describe the phylogenetic and functional changes in the intestinal microbiome in disease states and in response to environmental and dietary modulations. This paper reviews recent studies cataloging the microbial phylotypes in the GI tract of cats.

  9. The chicken gastrointestinal microbiome.

    PubMed

    Oakley, Brian B; Lillehoj, Hyun S; Kogut, Michael H; Kim, Woo K; Maurer, John J; Pedroso, Adriana; Lee, Margie D; Collett, Stephen R; Johnson, Timothy J; Cox, Nelson A

    2014-11-01

    The domestic chicken is a common model organism for human biological research and of course also forms the basis of a global protein industry. Recent methodological advances have spurred the recognition of microbiomes as complex communities with important influences on the health and disease status of the host. In this minireview, we provide an overview of the current state of knowledge of the chicken gastrointestinal microbiome focusing on spatial and temporal variability, the presence and importance of human pathogens, the influence of the microbiota on the immune system, and the importance of the microbiome for poultry nutrition. Review and meta-analysis of public data showed cecal communities dominated by Firmicutes and Bacteroides at the phylum level, while at finer levels of taxonomic resolution, a phylogenetically diverse assemblage of microorganisms appears to have similar metabolic functions that provide important benefits to the host as inferred from metagenomic data. This observation of functional redundancy may have important implications for management of the microbiome. We foresee advances in strategies to improve gut health in commercial operations through management of the intestinal microbiota as an alternative to in-feed subtherapeutic antibiotics, improvements in pre- and probiotics, improved management of polymicrobial poultry diseases, and better control of human pathogens via colonization reduction or competitive exclusion strategies.

  10. Porous PLGA microspheres tailored for dual delivery of biomolecules via layer-by-layer assembly.

    PubMed

    Go, Dewi P; Palmer, Jason A; Mitchell, Geraldine M; Gras, Sally L; O'Connor, Andrea J

    2015-05-01

    Tissue engineering is a complex and dynamic process that requires varied biomolecular cues to promote optimal tissue growth. Consequently, the development of delivery systems capable of sequestering more than one biomolecule with controllable release profiles is a key step in the advancement of this field. This study develops multilayered polyelectrolyte films incorporating alpha-melanocyte stimulating hormone (α-MSH), an anti-inflammatory molecule, and basic fibroblast growth factor (bFGF). The layers were successfully formed on macroporous poly lactic-co-glycolic acid microspheres produced using a combined inkjet and thermally induced phase separation technique. Release profiles could be varied by altering layer properties including the number of layers and concentrations of layering molecules. α-MSH and bFGF were released in a sustained manner and the bioactivity of α-MSH was shown to be preserved using an activated macrophage cell assay in vitro. The system performance was also tested in vivo subcutaneously in rats. The multilayered microspheres reduced the inflammatory response induced by a carrageenan stimulus 6 weeks after implantation compared to the non-layered microspheres without the anti-inflammatory and growth factors, demonstrating the potential of such multilayered constructs for the controlled delivery of bioactive molecules.

  11. Tuning of whispering gallery modes of polymeric micro-spheres and shells using external electric field

    NASA Astrophysics Data System (ADS)

    Ioppolo, Tindaro; Ayaz, Ulas; Ötügen, M. Volkan

    2010-02-01

    The electrostriction effect on the whispering gallery modes (WGM) of polymeric micro-spheres is investigated analytically and experimentally. Electrostriction is the elastic deformation (mechanical strain) of a dielectric material due the force exerted by an electric field. The elastic deformation also leads to mechanical stress which perturbs the refractive index of the sphere. Both if these effects (strain and stress) induce a shift in the WGM of the dielectric microsphere. We develop analytical expressions for the WGM shift due to electrostriction for solid and thin-walled micro-shells. The analytical results show that detection of electric fields < 1000 V/m is possible using water filled PDMS microshells. The electric field sensitivities for solid spheres, on the other hand, are significantly smaller. Results of experiments carried out using solid polydimethylsiloxane (PDMS) spheres agree well with the analytical prediction. These results are encouraging for future development of WGM-based optical switches/filters as well as electric field sensors.

  12. Cell specific, variable density, polymer microspheres

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Molday, Robert S. (Inventor)

    1978-01-01

    Biocompatible polymeric microspheres having an average diameter below about 3 microns and having a density at least 15% greater or lesser than organic cells and having covalent binding sites are provided in accordance with this invention. The microspheres are obtained by copolymerizing a hydroxy or amine substituted acrylic monomer such as hydroxyethylmethacrylate with a light or dense comonomer such as a fluoromonomer. A lectin or antibody is bound to the hydroxy or amine site of the bead to provide cell specificity. When added to a cell suspension the marked bead will specifically label the cell membrane by binding to specific receptor sites thereon. The labelled membrane can then be separated by density gradient centrifugation.

  13. Fluorescence dynamics of microsphere-adsorbed sunscreens

    NASA Astrophysics Data System (ADS)

    Krishnan, R.

    2005-03-01

    Sunscreens are generally oily substances which are prepared in organic solvents, emulsions or dispersions with micro- or nanoparticles. These molecules adsorb to and integrate into skin cells. In order to understand the photophysical properties of the sunscreen, we compare steady-state and time-resolved fluorescence in organic solvent of varying dielectric constant ɛ and adsorbed to polystyrene microspheres and dispersed in water. Steady-state fluorescence is highest and average fluorescence lifetime longest in toluene, the solvent of lowest ɛ. However, there is no uniform dependence on ɛ. Sunscreens PABA and padimate-O show complex emission spectra. Microsphere-adsorbed sunscreens exhibit highly non-exponential decay, illustrative of multiple environments of the adsorbed molecule. The heterogeneous fluorescence dynamics likely characterizes sunscreen adsorbed to cells.

  14. Neutron transmission measurements on hydrogen filled microspheres

    NASA Astrophysics Data System (ADS)

    Dyrnjaja, Eva; Hummel, Stefan; Keding, Marcus; Smolle, Marie-Theres; Gerger, Joachim; Zawisky, Michael

    2014-01-01

    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d≈15μm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed.

  15. Delivering Mesenchymal Stem Cells in Collagen Microsphere Carriers to Rabbit Degenerative Disc: Reduced Risk of Osteophyte Formation

    PubMed Central

    Li, Yuk Yin; Diao, Hua Jia; Chik, Tze Kit; Chow, Cin Ting; An, Xiao Meng; Leung, Victor; Cheung, Kenneth Man Chi

    2014-01-01

    Mesenchymal stem cells (MSCs) have the potential to treat early intervertebral disc (IVD) degeneration. However, during intradiscal injection, the vast majority of cells leaked out even in the presence of hydrogel carrier. Recent evidence suggests that annulus puncture is associated with cell leakage and contributes to osteophyte formation, an undesirable side effect. This suggests the significance of developing appropriate carriers for intradiscal delivery of MSCs. We previously developed a collagen microencapsulation platform, which entraps MSCs in a solid microsphere consisting of collagen nanofiber meshwork. These solid yet porous microspheres support MSC attachment, survival, proliferation, migration, differentiation, and matrix remodeling. Here we hypothesize that intradiscal injection of MSCs in collagen microspheres will outperform that of MSCs in saline in terms of better functional outcomes and reduced side effects. Specifically, we induced disc degeneration in rabbits and then intradiscally injected autologous MSCs, either packaged within collagen microspheres or directly suspended in saline, into different disc levels. Functional outcomes including hydration index and disc height were monitored regularly until 6 months. Upon sacrifice, the involved discs were harvested for histological, biochemical, and biomechanical evaluations. MSCs in collagen microspheres showed advantage over MSCs in saline in better maintaining the dynamic mechanical behavior but similar performance in hydration and disc height maintenance and matrix composition. More importantly, upon examination of gross appearance, radiograph, and histology of IVD, delivering MSCs in collagen microspheres significantly reduced the risk of osteophyte formation as compared to that in saline. This work demonstrates the significance of using cell carriers during intradiscal injection of MSCs in treating disc degeneration. PMID:24372278

  16. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  17. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, Arthur T.; Hosford, Charles D.

    1981-01-01

    Microspheres are substantially uniformly coated with metals or nonmetals by simultaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure 12 comprising a parallel array of upwardly projecting individual gas outlets 16 is machined out to form a dimple 11. Glass microballoons, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  18. Pulmonary toxicity of Expancel microspheres in the rat.

    PubMed

    Porter, Dale W; Hubbs, Ann F; Baron, Paul A; Millecchia, Lyndell L; Wolfarth, Michael G; Battelli, Lori A; Schwegler-Berry, Diane E; Beighley, Christopher M; Andrew, Michael E; Castranova, Vincent

    2007-08-01

    Expancel microspheres are thermoplastic microspheres enclosing hydrocarbon. These microspheres expand when heated, producing many applications. Because they have unknown biological persistence and toxicity, we investigated the toxicity of two unexpanded (11.1 and 15.4 micro m mean diameter) and two expanded (3.1 and 5.5 micro m mass median aerodynamic diameter) Expancel microspheres in intratracheally-instilled, male, Sprague-Dawley rats. Pulmonary histopathology was evaluated at 28 days postexposure. Bronchoalveolar lavage fluid was evaluated at days 1, 7, 14, and 28 days postexposure. Crystalline silica was the positive control. By histopathology, both unexpanded and expanded microspheres caused granulomatous bronchopneumonia characterized by macrophages and giants cells, suggesting a persistent foreign body response. Expanded, but not unexpanded microspheres, also caused eosinophilic bronchitis and bronchiolitis, mucous metaplasia of airways and organized granulomatous inflammation with associated fibrosis and frequent airway obstruction. In contrast, alveolar macrophage activation, polymorphonuclear leukocytes, LDH and albumin in bronchoalveolar laveage fluid were initially elevated but returned to near control levels at 28 days, and did not reflect the persistent granulomatous bronchopneumonia caused by Expancel microspheres. These findings emphasize the importance of histopathology for evaluating pulmonary toxicity, suggest that Expancel microspheres are a potential occupational hazard, and indicate a need for additional studies on their potential pulmonary toxicity. [Supplementary materials are available for this article. Go to the publisher's online edition of Toxicology Pathology for the following free supplemental resources: motion within unexpected microspheres in H&E-stained lung (supplementary Figure 1); broncholar epithelium 28 days following exposure to 551 DE 20 microspheres (supplementary Figure 2); membrane ruffling and some instances of

  19. Bridging and caging in mixed suspensions of microsphere and adsorptive microgel.

    PubMed

    Zhao, Chuanzhuang; Yuan, Guangcui; Han, Charles C

    2014-11-28

    Gelation and glass transition in a mixed suspension of polystyrene (PS) microsphere and poly(N-isopropylacrylamide) (PNIPAM) microgel were studied as a function of the total colloid volume fraction and mixing ratio of these two components. The PNIPAM microgel, which is adsorbable on the PS microsphere surface, can induce bridging or stabilizing effect between microspheres depending on whether the volume fraction of microgel (ΦMG) is smaller or larger than the saturated adsorption concentration (Φ*MG) for a given volume fraction of the microsphere (ΦMS). Φ*MG is in a linear relationship with ΦMS, and the value of ΦMG/Φ*MG can be taken as an approximate measure of surface coverage. A state diagram of gelation and glass transition is constructed with the short-ranged attractive interaction, resulting from the well-defined bridging bonding. Keeping ΦMG/Φ*MG = 0.20 and increasing ΦMS from 0.25 to 0.55, the mixed suspension transforms from a bridging gel into an attractive glass; moreover, while keeping ΦMS = 0.45 and increasing ΦMG/Φ*MG from 0.20 to 1.2, the mixed suspension changes from a bridging gel into an attractive glass, and then to a repulsive glass. The bridging effect and the cage effect can be distinguished by the yielding behaviors in rheological measurements. In the nonlinear dynamic rheological experiments, one-step yielding, corresponding to the disconnecting of bridge network, is observed in the bridging gel, and one-step yielding, corresponding to the breaking of cage, is observed in the repulsive glass. However, a two-step yielding behavior is found in the bridging-induced attractive glass, which is attributed to the bridging effect of microgels and the caging effect of the dense environment. PMID:25280208

  20. Primary gastrointestinal lymphomas.

    PubMed

    Cooper, D L; Doria, R; Salloum, E

    1996-03-01

    Recent evidence suggests that a significant proportion of primary gastrointestinal lymphomas are driven by exogenous agents/antigens. In the stomach, Helicobacter pylori appears to be responsible for most cases of low-grade lymphomas (MALToma), whereas an infectious etiology is suspected in immunoproliferative small intestine disease (IPSID). Similarly, enteropathy-associated T-cell lymphomas appear to result from a disordered response to gluten, although this profile remains controversial. Accordingly, although traditional antineoplastic treatments, such as surgery and radiation, are still important for the treatment of primary GI lymphomas, antibiotics may be the first line of therapy for low-grade gastric MALToma, and they are often used alone or in combination with chemotherapy for IPSID. In patients with celiac sprue, a gluten-free diet appears to markedly reduce the risk for lymphoma. An important caveat for the treatment of gastric lymphomas is that only low-grade gastric MALTomas have consistently responded to antibiotics. Treatment of high-grade gastric lymphoma is evolving. Although surgery was once considered central to diagnosis, staging, and treatment of gastric lymphoma, most patients can now have a diagnosis established by endoscopic biopsy and are candidates for chemotherapy and adjuvant radiation. The risks of fatal hemorrhage and perforation have probably been vastly overestimated and appear to be equal or less than the mortality associated with surgery. In addition, the long-term effects of gastric resection on quality of life have been almost completely ignored. Systemic lymphomas involve the GI tract far more often than is clinically apparent. In most cases, treatment should not be affected.

  1. Surveillance for gastrointestinal malignancies

    PubMed Central

    Tiwari, Ashish K; Laird-Fick, Heather S; Wali, Ramesh K; Roy, Hemant K

    2012-01-01

    Gastrointestinal (GI) malignancies are notorious for frequently progressing to advanced stages even in the absence of serious symptoms, thus leading to delayed diagnoses and dismal prognoses. Secondary prevention of GI malignancies through early detection and treatment of cancer-precursor/premalignant lesions, therefore, is recognized as an effective cancer prevention strategy. In order to efficiently detect these lesions, systemic application of screening tests (surveillance) is needed. However, most of the currently used non-invasive screening tests for GI malignancies (for example, serum markers such as alpha-fetoprotein for hepatocellular carcinoma, and fecal occult blood test, for colon cancer) are only modestly effective necessitating the use of highly invasive endoscopy-based procedures, such as esophagogastroduodenoscopy and colonoscopy for screening purposes. Even for hepatocellular carcinoma where non-invasive imaging (ultrasonography) has become a standard screening tool, the need for repeated liver biopsies of suspicious liver nodules for histopathological confirmation can’t be avoided. The invasive nature and high-cost associated with these screening tools hinders implementation of GI cancer screening programs. Moreover, only a small fraction of general population is truly predisposed to developing GI malignancies, and indeed needs surveillance. To spare the average-risk individuals from superfluous invasive procedures and achieve an economically viable model of cancer prevention, it’s important to identify cohorts in general population that are at substantially high risk of developing GI malignancies (risk-stratification), and select suitable screening tests for surveillance in these cohorts. We herein provide a brief overview of such high-risk cohorts for different GI malignancies, and the screening strategies that have commonly been employed for surveillance purpose in them. PMID:22969223

  2. Coacervate droplets, proteinoid microspheres, and the genetic apparatus

    NASA Technical Reports Server (NTRS)

    Fox, S. W.

    1974-01-01

    Differences between typical coacervate droplets and typical proteinoid microspheres are examined. It is pointed out that coacervate droplets are produced from polymers obtained from contemporary organisms. The microspheres considered are aggregates of proteinoid formed from monomeric amino acids under geologically relevant conditions. Aspects regarding the primordial sequence are discussed along with the origin of the genetic apparatus and the genetic code.

  3. Porous-wall hollow glass microspheres as carriers for biomolecules

    DOEpatents

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven

    2013-09-17

    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  4. Characterization of carbon cryogel microspheres as adsorbents for VOC.

    PubMed

    Yamamoto, Takuji; Kataoka, Sho; Ohmori, Takao

    2010-05-15

    Adsorption characteristics of carbon cryogel microspheres (CC microspheres) with controlled porous structure composed of mesopores (2 nmmicrospheres could be changed by varying either the size of the mesopores or the volume of the micropores. The peak temperature of the temperature-programmed desorption profiles of toluene from the CC microspheres was higher than that from granular activated carbon (GAC) with numerous micropores, indicating that toluene is adsorbed more strongly on CC microspheres than on GAC. To permit the practical use of CC microspheres, the adsorption characteristic of moisture on CC microspheres and GAC were evaluated. The effect of adsorption of moisture on the gas permeation property of an adsorption module prepared from the CC microspheres was also examined. PMID:20042276

  5. Fluorescent Microspheres as Point Sources: A Localization Study

    PubMed Central

    Chao, Jerry; Lee, Taiyoon; Ward, E. Sally; Ober, Raimund J.

    2015-01-01

    The localization of fluorescent microspheres is often employed for drift correction and image registration in single molecule microscopy, and is commonly carried out by fitting a point spread function to the image of the given microsphere. The mismatch between the point spread function and the image of the microsphere, however, calls into question the suitability of this localization approach. To investigate this issue, we subject both simulated and experimental microsphere image data to a maximum likelihood estimator that localizes a microsphere by fitting an Airy pattern to its image, and assess the suitability of the approach by evaluating the ability of the estimator to recover the true location of the microsphere with the best possible accuracy as determined based on the Cramér-Rao lower bound. Assessing against criteria based on the standard errors of the mean and the variance for an ideal estimator of the microsphere’s location, we find that microspheres up to 100 nm in diameter can in general be localized using a fixed width Airy pattern, and that microspheres as large as 1 μm in diameter can in general be localized using a floated width Airy pattern. PMID:26218251

  6. Pectin/zein microspheres as a sustained drug delivery system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of microspheres were prepared from pectins and corn proteins from various sources in the presence of the divalent ions calcium or zinc. The results showed that the yield of microsphere and the efficiency of drug incorporation were dependent on the type and ratio of biopolymers, the size of ...

  7. Surface molecularly imprinted magnetic microspheres for the recognition of albumin.

    PubMed

    Kartal, Fatma; Denizli, Adil

    2014-08-01

    A new approach, combining metal coordination with the molecular imprinting technique, was developed to prepare affinity materials. Magnetic poly(glycidyl methacrylate) microspheres in monosize form were used for specific recognition toward the target protein. The magnetic poly(glycidyl methacrylate) microspheres were prepared by dispersion polymerization in the presence of magnetite nanopowder. Surface imprinted magnetic poly(glycidyl methacrylate) microspheres based on metal coordination were prepared and used for the selective recognition of human serum albumin. Iminodiacetic acid was used as the metal coordinating agent and human serum albumin was anchored by Cu(2+) ions on the surface of magnetic poly(glycidyl methacrylate) microspheres by metal coordination. The magnetic poly(glycidyl methacrylate) microspheres were coated with a polymer formed by condensation of tetraethyl orthosilicate and 3-aminopropyltrimethoxysilane. The human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres were characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy and particle size analysis. The maximum adsorption capacity of human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres was 37.7 mg/g polymer at pH 6.0. The selectivity experiments of human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres prepared with different concentrations in the presence of lysozyme, bovine serum albumin and cytochrome C were performed in order to determine the relative selectivity coefficients.

  8. Rapid biomimetic mineralization of hydroxyapatite-g-PDLLA hybrid microspheres.

    PubMed

    Du, Ke; Shi, Xudong; Gan, Zhihua

    2013-12-10

    Hydroxyapatite-graft-poly(D,L-lactide) (HA-g-PDLLA) nanoparticles were synthesized here to fabricate hybrid microspheres with diameter in the range of 150-200 μm by emulsion solvent evaporation techniques. The as-obtained microspheres were treated with alkaline solution in order to selectively degrade the PDLLA layer which covered on the surface of hybrid microspheres and instead to generate a dense coating of HA nanoparticles. The hybrid microspheres with enriched HA nanoparticles on the surface were further immersed in simulated body fluid (SBF) solution to evaluate the bone-forming ability of the bioactive hybrid microspheres via the in vitro biomimetic mineralization process. The resultant microspheres were analyzed by using X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to understand the nucleation and growth of bioactive calcium phosphate (Ca-P) crystals as a function of surface treatment. Results in this work clearly demonstrated that the existing HA nanoparticles on the surface of hybrid microspheres after alkaline treatment greatly affect the growth of the bone-like Ca-P crystals in SBF solutions. The biomimetic hybrid microspheres were found to be excellent candidates for use as injectable scaffolds for bone tissue engineering.

  9. Resolution enhancement phase-contrast imaging by microsphere digital holography

    NASA Astrophysics Data System (ADS)

    Wang, Yunxin; Guo, Sha; Wang, Dayong; Lin, Qiaowen; Rong, Lu; Zhao, Jie

    2016-05-01

    Microsphere has shown the superiority of super-resolution imaging in the traditional 2D intensity microscope. Here a microsphere digital holography approach is presented to realize the resolution enhancement phase-contrast imaging. The system is designed by combining the microsphere with the image-plane digital holography. A microsphere very close to the object can increase the resolution by transforming the object wave from the higher frequency to the lower one. The resolution enhancement amplitude and phase images can be retrieved from a single hologram. The experiments are carried on the 1D and 2D gratings, and the results demonstrate that the observed resolution has been improved, meanwhile, the phase-contrast image is obtained. The proposed method can improve the transverse resolution in all directions based on a single exposure. Furthermore, this system has extended the application of the microsphere from the conventional 2D microscopic imaging to 3D phase-contrast microscopic imaging.

  10. Hollow porous-wall glass microspheres for hydrogen storage

    DOEpatents

    Heung, Leung K.; Schumacher, Ray F.; Wicks, George G.

    2010-02-23

    A porous wall hollow glass microsphere is provided having a diameter range of between 1 to 200 microns, a density of between 1.0 to 2.0 gm/cc, a porous-wall structure having wall openings defining an average pore size of between 10 to 1000 angstroms, and which contains therein a hydrogen storage material. The porous-wall structure facilitates the introduction of a hydrogen storage material into the interior of the porous wall hollow glass microsphere. In this manner, the resulting hollow glass microsphere can provide a membrane for the selective transport of hydrogen through the porous walls of the microsphere, the small pore size preventing gaseous or liquid contaminants from entering the interior of the hollow glass microsphere.

  11. Optical cavity modes of a single crystalline zinc oxide microsphere.

    PubMed

    Moirangthem, Rakesh Singh; Cheng, Pi-Ju; Chien, Paul Ching-Hang; Ngo, Buu Trong Huynh; Chang, Shu-Wei; Tien, Chung-Hao; Chang, Yia-Chung

    2013-02-11

    A detailed study on the optical cavity modes of zinc oxide microspheres under the optical excitation is presented. The zinc oxide microspheres with diameters ranging from 1.5 to 3.0 µm are prepared using hydrothermal growth technique. The photoluminescence measurement of a single microsphere shows prominent resonances of whispering gallery modes at room temperature. The experimentally observed whispering gallery modes in the photoluminescence spectrum are compared with theoretical calculations using analytical and finite element methods in order to clarify resonance properties of these modes. The comparison between theoretical analysis and experiment suggests that the dielectric constant of the ZnO microsphere is somewhat different from that for bulk ZnO. The sharp resonances of whispering gallery modes in zinc oxide microspheres cover the entire visible window. They may be utilized in realizations of optical resonators, light emitting devices, and lasers for future chip integrations with micro/nano optoelectronic circuits, and developments of optical biosensors. PMID:23481759

  12. Textiles with gallic acid microspheres: in vitro release characteristics.

    PubMed

    Martí, Meritxell; Martínez, Vanessa; Carreras, Núria; Alonso, Cristina; Lis, Manuel José; Parra, José Luis; Coderch, Luisa

    2014-01-01

    Abstract The aim of this study was to demonstrate the skin penetration of an antioxidant, gallic acid (GA), encapsulated in poly-ε-caprolactone (PCL) microspheres and applied onto textile fabrics, by a specific in vitro percutaneous absorption methodology. Two techniques (particle size distribution and FTIR) were used to characterise the microspheres obtained. The amount of GA-loaded microspheres present in the biofunctional textiles was established before their use as a textile drug delivery system. More absorption and desorption of microspheres with GA for the polyamide fabric were found in comparison with cotton fabric. The percutaneous absorption results indicated that the skin penetration of GA released from PCL-microspheres that were applied directly to the skin was higher than when GA was embedded within biofunctional textiles, in conclusion, an interesting reservoir effect may be promoted when biofunctional textiles were used.

  13. Novel sustained release microspheres for pulmonary drug delivery.

    PubMed

    Cook, Robert O; Pannu, Rupi K; Kellaway, Ian W

    2005-05-01

    A novel process for generating sustained release (SR) particles for pulmonary drug delivery is described. High purity nanoparticles of a hydrophilic, ionised drug are entrapped within hydrophobic microspheres using a spray-drying approach. Sustained release of the model drug, terbutaline sulphate (TS), from the microspheres was found to be proportional to drug loading and phospholipid content. Microspheres with a 33% drug loading exhibited sustained release of 32.7% over 180 min in phosphate buffer. Release was not significantly different in simulated lung fluids. No significant burst release was observed which suggested that nanoparticles were coated effectively during spray-drying. The absence of nanoparticles at the microsphere surface was confirmed with confocal microscopy. The sustained release microspheres were formulated as a carrier-free dry powder for inhalation, and exhibited a favourable Fine Particle Fraction (FPF) of 46.5+/-1.8% and Mass Median Aerodynamic Diameter (MMAD) of 3.93+/-0.12 microm. PMID:15866336

  14. Synthesis and characterization of magnetic poly(glycidyl methacrylate) microspheres

    NASA Astrophysics Data System (ADS)

    Horák, Daniel; Petrovský, Eduard; Kapička, Aleš; Frederichs, Theodor

    2007-04-01

    Magnetic nanoparticles encapsulated in poly(glycidyl methacrylate) microspheres were prepared and their detailed structural and magnetic characteristics given. Iron oxide nanoparticles were obtained by chemical coprecipitation of Fe(II) and Fe(III) salts and stabilized with dextran, (carboxymethyl)dextran or tetramethylammonium hydroxide. The microspheres were prepared by emulsion or dispersion polymerization of glycidyl methacrylate in the presence of ferrofluid. The microspheres were uniform both in shape and usually also in size; their size distribution was narrow. All the magnetic parameters confirm superparamagnetic nature of the microspheres. Blocking temperature was not observed, suggesting the absence of magnetic interactions at low temperatures. This is most probably caused by complete encapsulation and the absence of agglomeration. Such microspheres can be used in biomedical applications.

  15. Primary Gastrointestinal Lymphoma

    PubMed Central

    Chen, Yinting; Chen, Yanzhu; Chen, Shaojie; Wu, Lili; Xu, Lishu; Lian, Guoda; Yang, Kege; Li, Yaqing; Zeng, Linjuan; Huang, Kaihong

    2015-01-01

    Abstract Primary gastrointestinal lymphoma (PGIL) is a rare malignant tumor without standard diagnosis and treatment methods. This study is aimed to systematically analyze its clinical characteristics and draw out an appropriate flow chart of diagnosis and treatment process for PGIL in China. This study retrospectively analyzed the clinicopathological characteristics, diagnostic approaches, prognostic factors, and therapeutic modalities in 415 cases of PGIL in Chinese province of Guangdong. A systematic review was conducted in 118 studies containing 5075 patients to further identify clinical manifestations and mortalities of therapeutic modalities. The most common clinical presentations were abdominal pain and bloody stools. Endoscopic biopsy was an important diagnostic means, and usually more than once to make a definite diagnosis. Retrospective multicenter clinical study showed that younger onset age (<60 years), female, one region involved, one lesion, early stage, International Prognostic Index (IPI ≤1), normal lactate dehydrogenase (LDH), normal albumin, and nonemergency operation were significant prognostic factors for B-cell lymphoma; non-B symptom, tumor restricted to gastric or ileocecal region, one lesion, performance status (PS ≤1), normal LDH, and nonsurgery alone were significant prognostic factors for T-cell lymphoma. Site of origin and IPI were independent prognostic factors for B-cell lymphoma; PS was the independent prognostic factor for T-cell lymphoma. And T-cell lymphoma had worse overall survival (OS) and progression-free survival (PFS) than B-cell lymphoma. Among different therapeutic modalities, chemotherapy alone or combined with surgery showed better OS and PFS than surgery alone for diffuse large B-cell lymphoma (DLBCL) of stage I/II E and T-cell lymphoma. For DLBCL of stage III E/IV and mucosa-associated lymphoid tissue lymphoma, OS and PFS did not differ among different therapeutic groups. In meta-analysis, surgery plus chemotherapy

  16. Gastrointestinal Amyloidosis Presenting with Multiple Episodes of Gastrointestinal Bleeding

    SciTech Connect

    Kim, Sang Hyeon Kang, Eun Ju; Park, Jee Won; Jo, Jung Hyun; Kim, Soo Jin; Cho, Jin Han; Kang, Myong Jin; Park, Byeong Ho

    2009-05-15

    Amyloidosis is characterized by the extracellular deposition of amyloid protein in various organs. Gastrointestinal involvement in amyloidosis is common, but a diagnosis of amyloidosis is often delayed. Severe gastrointestinal hemorrhage in amyloidosis is rare but can be fatal in some cases. We experienced a case of a 49-year-old man who presented with recurrent massive hematochezia. Although embolization was performed eight times for bleeding from different sites of the small intestine, hematochezia did not cease. We report the case, with a review of the literature.

  17. The behaviour of selected yttrium containing bioactive glass microspheres in simulated body environments.

    PubMed

    Cacaina, D; Ylänen, H; Simon, S; Hupa, M

    2008-03-01

    The study aims at the manufacture and investigation of biodegradable glass microspheres incorporated with yttrium potentially useful for radionuclide therapy of cancer. The glass microspheres in the SiO2-Na2O-P2O5-CaO-K2O-MgO system containing yttrium were prepared by conventional melting and flame spheroidization. The behaviour of the yttrium silicate glass microspheres was investigated under in vitro conditions using simulated body fluid (SBF) and Tris buffer solution (TBS), for different periods of time, according to half-life time of the Y-90. The local structure of the glasses and the effect of yttrium on the biodegradability process were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy and Back Scattered Electron Imaging of Scanning Electron Microscopy (BEI-SEM) equipped with Energy Dispersive X-ray (EDX) analysis. UV-VIS spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for analyzing the release behaviour of silica and yttrium in the two used solutions. The results indicate that the addition of yttrium to a bioactive glass increases its structural stability which therefore, induced a different behaviour of the glasses in simulated body environments.

  18. Microsphere-Incorporated Hybrid Thermogel for Neuronal Differentiation of Tonsil Derived Mesenchymal Stem Cells.

    PubMed

    Patel, Madhumita; Moon, Hyo Jung; Jung, Bo Kyung; Jeong, Byeongmoon

    2015-07-15

    Neuronal differentiation of tonsil-derived mesenchymal stem cells (TMSCs) is investigated in a 3D hybrid system. The hybrid system is prepared by increasing the temperature of poly(ethylene glycol)-poly(l-alanine) aqueous solution to 37 °C through the heat-induced sol-to-gel transition, in which TMSCs and growth factor releasing microspheres are suspended. The in situ formed gel exhibits a modulus of 800 Pa at 37 °C, similar to that of brain tissue, and it is robust enough to hold the microspheres and cells during the 3D culture of TMSCs. The neuronal growth factors are released over 12-18 d, and the TMSCs in a spherical shape initially undergo multipolar elongation during the 3D culture. Significantly higher expressions of the neuronal biomarkers such as nuclear receptor related protein (Nurr-1), neuron specific enolase, microtubule associated protein-2, neurofilament-M, and glial fibrillary acidic protein are observed in both mRNA level and protein level in the hybrid systems than in the control experiments. This study proves the significance of a controlled drug delivery concept in tissue engineering or regenerative medicine, and a 3D hybrid system with controlled release of growth factors from microspheres in a thermogel can be a very promising tool. PMID:26033880

  19. Microsphere-Incorporated Hybrid Thermogel for Neuronal Differentiation of Tonsil Derived Mesenchymal Stem Cells.

    PubMed

    Patel, Madhumita; Moon, Hyo Jung; Jung, Bo Kyung; Jeong, Byeongmoon

    2015-07-15

    Neuronal differentiation of tonsil-derived mesenchymal stem cells (TMSCs) is investigated in a 3D hybrid system. The hybrid system is prepared by increasing the temperature of poly(ethylene glycol)-poly(l-alanine) aqueous solution to 37 °C through the heat-induced sol-to-gel transition, in which TMSCs and growth factor releasing microspheres are suspended. The in situ formed gel exhibits a modulus of 800 Pa at 37 °C, similar to that of brain tissue, and it is robust enough to hold the microspheres and cells during the 3D culture of TMSCs. The neuronal growth factors are released over 12-18 d, and the TMSCs in a spherical shape initially undergo multipolar elongation during the 3D culture. Significantly higher expressions of the neuronal biomarkers such as nuclear receptor related protein (Nurr-1), neuron specific enolase, microtubule associated protein-2, neurofilament-M, and glial fibrillary acidic protein are observed in both mRNA level and protein level in the hybrid systems than in the control experiments. This study proves the significance of a controlled drug delivery concept in tissue engineering or regenerative medicine, and a 3D hybrid system with controlled release of growth factors from microspheres in a thermogel can be a very promising tool.

  20. Novel smart yolk/shell polymer microspheres as a multiply responsive cargo delivery system.

    PubMed

    Du, Pengcheng; Liu, Peng

    2014-03-25

    An effective strategy was developed to fabricate the novel dually thermo- and pH-responsive yolk/shell polymer microspheres as a drug delivery system (DDS) for the controlled release of anticancer drugs via two-stage distillation precipitation polymerization and seed precipitation polymerization. Their pH-induced thermally responsive polymer shells act as a smart "valve" to adjust the diffusion of the loaded drugs in/out of the polymer containers according to the body environments, while the movable P(MAA-co-EGDMA) cores enhance the drug loading capacity for the anticancer drug doxorubicin hydrochloride (DOX). The yolk/shell polymer microspheres show a low leakage at high pH values but significantly enhanced release at lower pH values equivalent to the tumor body fluid environments at human body temperature, exhibiting the apparent tumor-environment-responsive controlled "on-off" drug release characteristics. Meanwhile, the yolk/shell microspheres expressed very low in vitro cytotoxicity on HepG2 cells. Consequently, their precise tumor-environment-responsive drug delivery performance and high drug loading capacity offer promise for tumor therapy.

  1. Camptothecine encapsulated composite drug delivery system for colorectal peritoneal carcinomatosis therapy: biodegradable microsphere in thermosensitive hydrogel.

    PubMed

    Liu, Lei; Wu, Qinjie; Ma, Xuelei; Xiong, Dake; Gong, Changyang; Qian, Zhiyong; Zhao, Xia; Wei, Yuquan

    2013-06-01

    In this work, we developed a biodegradable and injectable composite drug delivery system (DDS), camptothecine (CPT) loaded polymeric microsphere in thermosensitive hydrogel, for colorectal peritoneal carcinomatosis (CRPC) therapy. In our previous studies, we found that poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, PCEC) copolymers with different molecular weight and PEG/PCL ratio could be administrated to form microsphere or thermosensitive hydrogel, respectively. Therefore, the composite DDS was composed of CPT loaded microsphere (CPT-MS) and thermosensitive hydrogel. CPT-MS was prepared by CPT and PCEC copolymer (Mn=31,600) using an oil-in-water emulsion solvent evaporation method. Besides, biodegradable and injectable thermosensitive PCEC hydrogel (Mn=3150) with lower sol-gel transition temperature at around body temperature was also prepared. The CPT-MS in thermosensitive hydrogel (CPT-MS/hydrogel) composite is a free-flowing sol at ambient temperature and instantly converts into a non-flowing gel at body temperature. Furthermore, cytotoxicity assay indicated that both microsphere and hydrogel were biocompatible with very low cytotoxicity. In vitro release profile demonstrated a significant difference between rapid release of free CPT and much slower and sustained release of CPT-MS/hydrogel. In addition, intraperitoneal administration of CPT-MS/hydrogel could effectively suppress growth and metastasis of CT26 peritoneal carcinomatosis in vivo, and prolonged the survival of tumor bearing mice. Compared with CPT-MS or free CPT, CPT-MS/hydrogel induced a stronger anti-tumor effect by increasing apoptosis of tumor cells and inhibiting microvessel density of tumor tissue. Besides, side effects of CPT were also alleviated in CPT-MS/hydrogel-treated mice. Thus, our results suggested that CPT-MS/hydrogel may have great potential applications in clinic.

  2. PCL-PDMS-PCL copolymer-based microspheres mediate cardiovascular differentiation from embryonic stem cells

    NASA Astrophysics Data System (ADS)

    Song, Liqing

    Poly-epsilon-caprolactone (PCL) based copolymers have received much attention as drug or growth factor delivery carriers and tissue engineering scaffolds due to their biocompatibility, biodegradability, and tunable biophysical properties. Copolymers of PCL and polydimethylsiloxane (PDMS) also have shape memory behaviors and can be made into thermoresponsive shape memory polymers for various biomedical applications such as smart sutures and vascular stents. However, the influence of biophysical properties of PCL-PDMS-PCL copolymers on stem cell lineage commitment is not well understood. In this study, PDMS was used as soft segments of varying length to tailor the biophysical properties of PCL-based co-polymers. While low elastic modulus (<10 kPa) of the tri-block copolymer PCL-PDMS-PCL affected cardiovascular differentiation of embryonic stem cells, the range of 60-100 MPa PCL-PDMS-PCL showed little influence on the differentiation. Then different size (30-140 mum) of microspheres were fabricated from PCL-PDMS-PCL copolymers and incorporated within embryoid bodies (EBs). Mesoderm differentiation was induced using bone morphogenetic protein (BMP)-4 for cardiovascular differentiation. Differential expressions of mesoderm progenitor marker KDR and vascular markers CD31 and VE-cadherin were observed for the cells differentiated from EBs incorporated with microspheres of different size, while little difference was observed for cardiac marker alpha-actinin expression. Small size of microspheres (30 mum) resulted in higher expression of KDR while medium size of microspheres (94 mum) resulted in higher CD31 and VE-cadherin expression. This study indicated that the biophysical properties of PCL-based copolymers impacted stem cell lineage commitment, which should be considered for drug delivery and tissue engineering applications.

  3. Preprocedural considerations in gastrointestinal endoscopy.

    PubMed

    Gorospe, Emmanuel C; Oxentenko, Amy S

    2013-09-01

    The current practice of open-access endoscopy allows primary care and other non-gastroenterology physicians to directly refer patients for routine gastrointestinal endoscopic procedures. Open-access endoscopy is considered to be more cost-effective and time efficient than the traditional practice of referring patients for preprocedural consultation with a gastrointestinal endoscopist. Several studies have evaluated the performance of endoscopic procedures in an open-access environment and the utility of structured referral mechanisms to ensure safe and appropriately indicated procedures. This review focuses on 4 common preprocedural issues in gastrointestinal endoscopy encountered by primary care physicians: management of anticoagulation and antiplatelet therapy, indication for prophylactic antibiotic drug therapy, need for anesthesia-assisted sedation, and management of poor bowel preparation. We summarize the current guidelines that address these 4 common preprocedural issues to facilitate safe and clinically appropriate procedures in open-access endoscopy.

  4. Nutritional support and gastrointestinal disease.

    PubMed

    Hennessy, K

    1989-06-01

    The use of nutritional support in patients with acute gastrointestinal disease requires a thorough knowledge of the pathophysiology and nutritional alterations that are caused by the disease process. Although nutritional therapy of a patient with gastrointestinal disease is not curative of the underlying disease, it does provide essential support to the patient, which improves response to, and eventual recovery from, illness. Special considerations need to be made to avoid complicating the patient's condition by inappropriate use of nutritional support solutions, which can lead to abnormal liver function. PMID:2498848

  5. Blood thinners and gastrointestinal endoscopy

    PubMed Central

    Ahmed, Monjur

    2016-01-01

    As the number of diagnostic and therapeutic gastrointestinal endoscopies is increasing, and there is an increase in number of patients taking blood thinners, we are seeing more and more patients on blood thinners prior to endoscopic procedures. Gastrointestinal bleeding or thromboembolism can occur in this category of patients in the periendoscopic period. To better manage these patients, endoscopists should have a clear concept about the various blood thinners in the market. Patients’ risk of thromboembolism off anticoagulation, and the risk of bleeding from endoscopic procedures should be assessed prior to endoscopy. The endoscopic procedure should be done when it is safe to do it. PMID:27668068

  6. Blood thinners and gastrointestinal endoscopy

    PubMed Central

    Ahmed, Monjur

    2016-01-01

    As the number of diagnostic and therapeutic gastrointestinal endoscopies is increasing, and there is an increase in number of patients taking blood thinners, we are seeing more and more patients on blood thinners prior to endoscopic procedures. Gastrointestinal bleeding or thromboembolism can occur in this category of patients in the periendoscopic period. To better manage these patients, endoscopists should have a clear concept about the various blood thinners in the market. Patients’ risk of thromboembolism off anticoagulation, and the risk of bleeding from endoscopic procedures should be assessed prior to endoscopy. The endoscopic procedure should be done when it is safe to do it.

  7. Blood thinners and gastrointestinal endoscopy.

    PubMed

    Ahmed, Monjur

    2016-09-16

    As the number of diagnostic and therapeutic gastrointestinal endoscopies is increasing, and there is an increase in number of patients taking blood thinners, we are seeing more and more patients on blood thinners prior to endoscopic procedures. Gastrointestinal bleeding or thromboembolism can occur in this category of patients in the periendoscopic period. To better manage these patients, endoscopists should have a clear concept about the various blood thinners in the market. Patients' risk of thromboembolism off anticoagulation, and the risk of bleeding from endoscopic procedures should be assessed prior to endoscopy. The endoscopic procedure should be done when it is safe to do it. PMID:27668068

  8. Ultrafast microsphere near-field nanostructuring

    NASA Astrophysics Data System (ADS)

    Leitz, K.-H.; Quentin, U.; Hornung, B.; Otto, A.; Alexeev, I.; Schmidt, M.

    2011-03-01

    Due to the steadily advancing miniaturization in all fields of technology nanostructuring becomes increasingly important. Whereas the classical lithographic nanostructuring suffers from both high costs and low flexibility, for many applications in biomedicine and technology laser based nanostructuring approaches, where near-field effects allow a sub-diffraction limited laser focusing, are on the rise. In combination with ultrashort pulsed laser sources, that allow the utilization of non-linear multi-photon absorption effects, a flexible, low-cost laser based nanostructuring with sub-wavelength resolution becomes possible. Among various near-field nanostructuring approaches the microsphere based techniques, which use small microbead particles of the size of the wavelength for a sub-diffraction limited focusing of pulsed laser radiation, are the most promising. Compared to the tip or aperture based techniques this approach is very robust and can be applied both for a large-scale production of periodic arrays of nanostructures and in combination with optical trapping also for a direct-write. Size and shape of the features produced by microsphere near-field nanostructuring strongly depend on the respective processing parameters. In this contribution a basic study of the influence of processing parameters on the microsphere near-field nanostructuring with nano-, pico- and femtosecond laser pulses will be presented. The experimental and numerical results with dielectric and metal nanoparticles on semiconductor and dielectric substrates show the influence of particle size and material, substrate material, pulse duration, laser fluence, number of contributing laser pulses and polarization on the structuring process.

  9. Eosinophilic gastroenteritis with refractory ulcer disease and gastrointestinal bleeding as a rare manifestation of seronegative gastrointestinal food allergy.

    PubMed

    Raithel, Martin; Hahn, Markus; Donhuijsen, Konrad; Hagel, Alexander F; Nägel, Andreas; Rieker, Ralf J; Neurath, Markus F; Reinshagen, Max

    2014-09-17

    Gastrointestinal bleeding and iron deficiency anaemia may cause severe symptoms and may require extensive diagnostics and substantial amounts of health resources.This case report focuses on the clinical presentation of a 22 year old patient with recurrent gastrointestinal bleeding from multilocular non-healing ulcers of the stomach, duodenum and jejunum over a period of four years. Extensive gastroenterological and allergological standard diagnostic procedures showed benign ulcerative lesions with tissue eosinophilia, but no conclusive diagnosis. Multiple diagnostic procedures were performed, until finally, endoscopically guided segmental gut lavage identified locally produced, intestinal IgE antibodies by fluoro-enzyme-immunoassay.IgE antibody concentrations at the intestinal level were found to be more-fold increased for total IgE and food-specific IgE against nuts, rye flour, wheat flour, pork, beef and egg yolk compared with healthy controls.Thus, a diet eliminating these allergens was introduced along with antihistamines and administration of a hypoallergenic formula, which resulted in complete healing of the multilocular ulcers with resolution of gastrointestinal bleeding. All gastrointestinal lesions disappeared and total serum IgE levels dropped to normal within 9 months. The patient has been in remission now for more than two years.Eosinophilic gastroenteritis (EG) is well known to induce refractory ulcer disease. In this case, the mechanisms for intestinal damage and gastrointestinal bleeding were identified as local gastrointestinal type I allergy. Therefore, future diagnostics in EG should also be focused on the intestinal level as identification of causative food-specific IgE antibodies proved to be effective to induce remission in this patient.

  10. Measurements of extrinsic fluorescence in Intralipid and polystyrene microspheres

    PubMed Central

    Du Le, Vinh Nguyen; Nie, Zhaojun; Hayward, Joseph E.; Farrell, Thomas J.; Fang, Qiyin

    2014-01-01

    The fluorescence of Intralipid and polystyrene microspheres with sphere diameter of 1 µm at a representative lipid and microsphere concentration for simulation of mucosal tissue scattering has not been a subject of extensive experimental study. In order to elucidate the quantitative relationship between lipid and microsphere concentration and the respective fluorescent intensity, the extrinsic fluorescence spectra between 360 nm and 650 nm (step size of 5 nm) were measured at different lipid concentrations (from 0.25% to 5%) and different microsphere concentrations (0.00364, 0.0073, 0.0131 spheres per cubic micrometer) using laser excitation at 355 nm with pulse energy of 2.8 µJ. Current findings indicated that Intralipid has a broadband emission between 360 and 650 nm with a primary peak at 500 nm and a secondary peak at 450 nm while polystyrene microspheres have a single peak at 500 nm. In addition, for similar scattering properties the fluorescence of Intralipid solutions is approximately three-fold stronger than that of the microsphere solutions. Furthermore, Intralipid phantoms with lipid concentrations ~2% (simulating the bottom layer of mucosa) produce up to seven times stronger fluorescent emission than phantoms with lipid concentration ~0.25% (simulating the top layer of mucosa). The fluoresence decays of Intralipid and microsphere solutions were also recorded for estimation of fluorescence lifetime. PMID:25136497

  11. Measurement of thermal diffusivity of depleted uranium metal microspheres

    NASA Astrophysics Data System (ADS)

    Humrickhouse-Helmreich, Carissa J.; Corbin, Rob; McDeavitt, Sean M.

    2014-03-01

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time-temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

  12. Magnetic poly(glycidyl methacrylate) microspheres for protein capture.

    PubMed

    Koubková, Jana; Müller, Petr; Hlídková, Helena; Plichta, Zdeněk; Proks, Vladimír; Vojtěšek, Bořivoj; Horák, Daniel

    2014-09-25

    The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis.

  13. Ultra-sensitive force measurement using optically levitated microspheres

    NASA Astrophysics Data System (ADS)

    Rider, Alexander; Moore, David; Gratta, Giorgio

    2015-04-01

    We have demonstrated a novel technique for measuring microscopic forces acting on optically levitated dielectric microspheres. The radiation field at the focus of a laser beam is used to levitate a microsphere in a harmonic trap where its displacement can be determined by the pattern of scattered light. Optical levitation isolates the microsphere from the surrounding environment at high vacuum, making thermal noise negligible. We have demonstrated a preliminary sensitivity of 5 ×10-17NHz - 1 / 2 for forces acting on 5 μm microspheres and expect to be able to improve this by several orders of magnitude once non-fundamental sources of noise are eliminated. The electric charge of a microsphere can be determined by applying an electric field and measuring the resulting force. We have demonstrated the ability to discharge the microspheres with single electron precision, which eliminates the most significant electrostatic backgrounds from force measurements. As a demonstration of this technique we have searched for the presence of unknown charged particles with charge > 5 ×10-5 e bound in our microspheres. Here we discuss the apparatus, the charged particle search, and outline our plans for future measurements including gravity at μm length scales.

  14. Bacteria as trigger for chronic gastrointestinal disorders.

    PubMed

    Marteau, Philippe; Chaput, Ulriikka

    2011-01-01

    Apart from acute infections, microorganisms may also induce or perpetuate chronic inflammatory diseases and reversible or irreversible proliferation of various cells in the gastrointestinal tract (the extreme being adenocarcinoma and lymphoma). Helicobacter pylori is not only involved in the pathogenesis of lymphoma and gastric adenocarcinoma. The steps and mechanisms of the carcinogenic process involve host predisposition, environmental factors, and strain virulence. The steps of lymphoma genesis include chronic inflammation, acquisition of mucosa-associated lymphoid tissue in the stomach, proliferation of the B lymphocytes in an inflammatory context, acquisition of genetic anomalies and dysregulation of the NF-κB pathway. The role of Campylobacter jejuni in immunoproliferative small bowel disease has also been shown and eradication of this bacterium can cure the lymphoma at its early stage. The evidence for the role of some bacteria in colon cancer development is discussed. Opportunistic pathogens are detected in the stools or mucosa of a proportion of subjects with Crohn's disease. They include Mycobacterium avium paratuberculosis, adherent invasive Escherichia coli, and Clostridium difficile. A dysbiosis has been repeatedly observed in patients with inflammatory bowel disease. Instability of the dominant microbiota and decreased biodiversity (especially in the firmicutes phylum) are major characteristics. The decrease of Faecalibacterium prausnitzii seems to have a prognostic value to predict relapse of Crohn's disease after surgery. Finally, important perspectives are opened by new tools such as metagenomics and metabolomics of the gastrointestinal ecosystems. Major tracks concern irritable bowel syndrome, colon cancer and obesity. PMID:21734380

  15. Hippo pathway regulation of gastrointestinal tissues.

    PubMed

    Yu, Fa-Xing; Meng, Zhipeng; Plouffe, Steven W; Guan, Kun-Liang

    2015-01-01

    The Hippo pathway plays a crucial role in regulating tissue homeostasis and organ size, and its deregulation is frequently observed in human cancer. Yap is the major effector of and is inhibited by the Hippo pathway. In mouse model studies, inducible Yap expression in multiple tissues results in organ overgrowth. In the liver, knockout of upstream Hippo pathway components or transgenic expression of Yap leads to liver enlargement and hepatocellular carcinoma. In the small intestine or colon, deletion of upstream Hippo pathway components also results in expansion of intestinal progenitor cells and eventual development of adenomas. Genetic deletion of Yap in the intestine does not change the intestinal structure, but Yap is essential for intestinal repair upon certain types of tissue injury. The function of the Hippo pathway has also been studied in other gastrointestinal tissues, including the pancreas and stomach. Here we provide a brief overview of the Hippo pathway and discuss the physiological and pathological functions of this tumor suppressor pathway in gastrointestinal tissues.

  16. Upper gastrointestinal bleeding in dengue fever.

    PubMed

    Tsai, C J; Kuo, C H; Chen, P C; Changcheng, C S

    1991-01-01

    Twenty-six virologically and serologically confirmed Dengue patients with signs of upper gastrointestinal tract bleeding (13.1%) were studied during the 1987 outbreak in southern Taiwan. Within a 1-yr period from 1987 to 1988 in Kaohsiung Chang Gung Memorial Hospital, there were 198 patients with Dengue fever confirmed. Viral isolation and serological studies indicated that type I Dengue was the cause. There was no evidence of sequential secondary infection among them. The 26 patients were evaluated gastroduodenoscopically. Most of the Dengue patients who developed upper gastrointestinal bleeding had gastric ulcers or duodenal ulcers; superficial and hemorrhagic gastritis are the other relevant endoscopic findings. Thirteen patients (50%) had a past history of peptic ulcer symptoms, whereas the other 13 did not. Dengue infection is a precipitating factor in inducing peptic ulcer bleeding because of hemostatic derangements. Supportive therapy and blood transfusions alone were adequate treatment, except for one patient who required surgery due to massive bleeding of a duodenal ulcer. No mortality was observed in this study.

  17. Protocell-like Microspheres from Thermal Polyaspartic Acid

    NASA Astrophysics Data System (ADS)

    Bahn, Peter R.; Pappelis, Aristotel; Bozzola, John

    2006-12-01

    One of the most prominent amino acids to appear in monomer-generating origin-of-life experiments is aspartic acid. Hugo Schiff found in 1897 that aspartic acid polymerizes when heated to form polyaspartylimide which hydrolyzes in basic aqueous solution to form thermal polyaspartic acid which is a branched polypeptide. We recently reported at the ISSOL 2005 Conference that commercially made thermal polyaspartic acid forms microspheres when heated in boiling water and allowed to cool. In a new experiment we heated aspartic acid at 180°C for up to 100 h to form thermal polyaspartylimide which when heated in boiling water without addition of base hydrolyzed to form thermal polyaspartic acid which upon cooling formed microspheres. Thermal polyaspartic acid microspheres appear protocell-like in the sense of being prebiotically plausible lattices or containers that could eventually have been filled with just the right additions of primordial proteins, nucleic acids, lipids, and metabolites so as to constitute protocells capable of undergoing further chemical and biological evolution. Thermal polyaspartic acid microspheres are extremely simple models of protocells that are more amenable to precise quantitative experimental investigation than the proteinoid microspheres of Sidney W. Fox. We present here scanning electron microscope images of such thermal polyaspartic acid microspheres. Figure 1 shows thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×. Figure 2 shows thermal polyaspartic acid microspheres from the same sample at a magnification of 7,000×. The thermal polyaspartic acid microspheres have a diameter of approximately 1 μm These images were viewed with a Hitachi S2460N scanning electron microscope at 20 kV acceleration voltage. [Figure not available: see fulltext.][Figure not available: see fulltext.

  18. The affinity of magnetic microspheres for Schistosoma eggs.

    PubMed

    Candido, Renata R F; Favero, Vivian; Duke, Mary; Karl, Stephan; Gutiérrez, Lucía; Woodward, Robert C; Graeff-Teixeira, Carlos; Jones, Malcolm K; St Pierre, Timothy G

    2015-01-01

    Schistosomiasis is a chronic parasitic disease of humans, with two species primarily causing the intestinal infection: Schistosoma mansoni and Schistosoma japonicum. Traditionally, diagnosis of schistosomiasis is achieved through direct visualisation of eggs in faeces using techniques that lack the sensitivity required to detect all infections, especially in areas of low endemicity. A recently developed method termed Helmintex™ is a very sensitive technique for detection of Schistosoma eggs and exhibits 100% sensitivity at 1.3 eggs per gram of faeces, enough to detect even low-level infections. The Helminthex™ method is based on the interaction of magnetic microspheres and schistosome eggs. Further understanding the underlying egg-microsphere interactions would enable a targeted optimisation of egg-particle binding and may thus enable a significant improvement of the Helmintex™ method and diagnostic sensitivity in areas with low infection rates. We investigated the magnetic properties of S. mansoni and S. japonicum eggs and their interactions with microspheres with different magnetic properties and surface functionalization. Eggs of both species exhibited higher binding affinity to the magnetic microspheres than the non-magnetic microspheres. Binding efficiency was further enhanced if the particles were coated with streptavidin. Schistosoma japonicum eggs bound more microspheres compared with S. mansoni. However, distinct differences within eggs of each species were also observed when the distribution of the number of microspheres bound per egg was modelled with double Poisson distributions. Using this approach, both S. japonicum and S. mansoni eggs fell into two groups, one having greater affinity for magnetic microspheres than the other, indicating that not all eggs of a species exhibit the same binding affinity. Our observations suggest that interaction between the microspheres and eggs is more likely to be related to surface charge-based electrostatic

  19. The affinity of magnetic microspheres for Schistosoma eggs.

    PubMed

    Candido, Renata R F; Favero, Vivian; Duke, Mary; Karl, Stephan; Gutiérrez, Lucía; Woodward, Robert C; Graeff-Teixeira, Carlos; Jones, Malcolm K; St Pierre, Timothy G

    2015-01-01

    Schistosomiasis is a chronic parasitic disease of humans, with two species primarily causing the intestinal infection: Schistosoma mansoni and Schistosoma japonicum. Traditionally, diagnosis of schistosomiasis is achieved through direct visualisation of eggs in faeces using techniques that lack the sensitivity required to detect all infections, especially in areas of low endemicity. A recently developed method termed Helmintex™ is a very sensitive technique for detection of Schistosoma eggs and exhibits 100% sensitivity at 1.3 eggs per gram of faeces, enough to detect even low-level infections. The Helminthex™ method is based on the interaction of magnetic microspheres and schistosome eggs. Further understanding the underlying egg-microsphere interactions would enable a targeted optimisation of egg-particle binding and may thus enable a significant improvement of the Helmintex™ method and diagnostic sensitivity in areas with low infection rates. We investigated the magnetic properties of S. mansoni and S. japonicum eggs and their interactions with microspheres with different magnetic properties and surface functionalization. Eggs of both species exhibited higher binding affinity to the magnetic microspheres than the non-magnetic microspheres. Binding efficiency was further enhanced if the particles were coated with streptavidin. Schistosoma japonicum eggs bound more microspheres compared with S. mansoni. However, distinct differences within eggs of each species were also observed when the distribution of the number of microspheres bound per egg was modelled with double Poisson distributions. Using this approach, both S. japonicum and S. mansoni eggs fell into two groups, one having greater affinity for magnetic microspheres than the other, indicating that not all eggs of a species exhibit the same binding affinity. Our observations suggest that interaction between the microspheres and eggs is more likely to be related to surface charge-based electrostatic

  20. Gastrointestinal epithelial neoplasia: Vienna revisited.

    PubMed

    Dixon, M F

    2002-07-01

    International consensus meetings in Padova and Vienna have attempted to rationalise the grading and classification of gastrointestinal epithelial neoplasia (GEN). With its minor adjustments, the Vienna classification of GEN seeks to be more closely in tune with patient management and it is hoped that it is not seen as fiddling around with terms but as a genuine contribution to patient care.

  1. [Motility and functional gastrointestinal disorders].

    PubMed

    Mearin, Fermín; Rey, Enrique; Balboa, Agustín

    2014-09-01

    This article discusses the studies on functional and motor gastrointestinal disorders presented at the 2014 Digestive Diseases Week conference that are of greatest interest to us. New data have been provided on the clinical importance of functional gastrointestinal disorders, with recent prevalence data for irritable bowel syndrome and fecal incontinence. We know more about the pathophysiological mechanisms of the various functional disorders, especially irritable bowel syndrome, which has had the largest number of studies. Thus, we have gained new data on microinflammation, genetics, microbiota, psychological aspects, etc. Symptoms such as abdominal distension have gained interest in the scientific community, both in terms of patients with irritable bowel syndrome and those with constipation. From the diagnostic point of view, the search continues for a biomarker for functional gastrointestinal disorders, especially for irritable bowel syndrome. In the therapeutic area, the importance of diet for these patients (FODMAP, fructans, etc.) is once again confirmed, and data is provided that backs the efficacy of already marketed drugs such as linaclotide, which rule out the use of other drugs such as mesalazine for patients with irritable bowel syndrome. This year, new forms of drug administration have been presented, including metoclopramide nasal sprays and granisetron transdermal patches for patients with gastroparesis. Lastly, a curiosity that caught our attention was the use of a vibrating capsule to stimulate gastrointestinal transit in patients with constipation.

  2. Gastrointestinal disease and its management.

    PubMed

    Jergens, A E

    1997-11-01

    Gastrointestinal (GI) diseases involving the alimentary tract and hepatobiliary system are common in geriatric dogs and cats. Inflammatory disorders predominate, but motility disturbances and degenerative lesions may also cause GI signs in affected animals. Treatment is directed at correction of the underlying cause and often requires tissue biopsy. The prognosis is good in many diseases with appropriate drug nutritional, and/or surgical therapy.

  3. Development of packaged silica microspheres coupled with tapered optical microfibres

    NASA Astrophysics Data System (ADS)

    Wang, Pengfei; Madugani, Ramgopal; Zhao, Haoyu; Ward, Jonathan; Yang, Yong; Farrell, Gerald; Brambilla, Gilberto; Nic Chormaic, Síle

    2016-03-01

    In this research, we present a packaged add-drop filter composed of a silica microsphere resonator and a strongly coupled optical microfiber coupler. A one-step fabrication process using UV curable epoxy is shown to stabilize the microsphere resonator coupled to the microfiber coupler, which is used as add and drop ports. A high Q-factor of 3×107 is obtained at around 780 nm from the packaged microspheres coupled with the microfiber coupler in the add-drop configuration.

  4. Observation of whispering gallery modes in microtube-microspheres system

    NASA Astrophysics Data System (ADS)

    Li, Hanyang; Hao, Sue; Qiang, Liangsheng; Li, Jin; Zhang, Yundong

    2013-06-01

    We proposed that a fluorescent microsphere with diameter of 6 μm was manipulated into a microtube with inner diameter of 6.2 μm. The whispering gallery modes (WGMs) of fluorescence resonance were observed by 532 nm laser pumping the microspheres-mircotube system. Another microsphere with the same diameter was manipulated into the microtube and mode splitting in the system of two spheres in contact in the mircotube was demonstrated. We also discussed relationship between WGMs peak intensity and the excitation power. The scheme will bring more insight into the applications of WGMs for biomedical diagnostics and microfluidics.

  5. Development of prilling process for biodegradable microspheres through experimental designs.

    PubMed

    Fabien, Violet; Minh-Quan, Le; Michelle, Sergent; Guillaume, Bastiat; Van-Thanh, Tran; Marie-Claire, Venier-Julienne

    2016-02-10

    The prilling process proposes a microparticle formulation easily transferable to the pharmaceutical production, leading to monodispersed and highly controllable microspheres. PLGA microspheres were used for carrying an encapsulated protein and adhered stem cells on its surface, proposing a tool for regeneration therapy against injured tissue. This work focused on the development of the production of PLGA microspheres by the prilling process without toxic solvent. The required production quality needed a complete optimization of the process. Seventeen parameters were studied through experimental designs and led to an acceptable production. The key parameters and mechanisms of formation were highlighted. PMID:26656302

  6. Packaged chalcogenide microsphere resonator with high Q-factor

    NASA Astrophysics Data System (ADS)

    Wang, Pengfei; Ding, Ming; Lee, Timothy; Senthil Murugan, Ganapathy; Bo, Lin; Semenova, Yuliya; Wu, Qiang; Hewak, Dan; Brambilla, Gilberto; Farrell, Gerald

    2013-04-01

    The fabrication and characterization of a packaged As2S3 microsphere resonator coupled to a tapered fiber using a low refractive index UV-curable polymer are reported. Embedding provides an efficient means to remove the highest order whispering gallery modes in the microsphere resonator, thus cleaning the resonator spectrum. At wavelengths near 1549.5 nm, high-Q modes up to 1.8 × 105 can be efficiently excited in a 110 μm diameter chalcogenide microsphere via evanescent coupling from a 2 μm diameter tapered silica fiber. The device photosensitivity, useful for tuning, is still present and useable after the packaging process.

  7. Effect of size of silica microspheres on photonic band gap

    SciTech Connect

    Dhiman, N. Sharma, A. Gathania, A. K.; Singh, B. P.

    2014-04-24

    In present work photonic crystals of different size of silica microspheres have been fabricated. The optical properties of these developed photonic crystals have been studied using UV-visible spectroscopy. UV-visible spectroscopy shows that they have photonic band gap that can be tuned in visible and infrared regime by changing the size of silica microspheres. The photonic band gap structures of these photonic crystals have been calculated using MIT photonic band gap package. It also reveals that with the increase in size of silica microspheres the photonic band gap shifts to lower energy region.

  8. Protein specific fluorescent microspheres for labelling a protein

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan (Inventor)

    1982-01-01

    Highly fluorescent, stable and biocompatible microspheres are obtained by copolymerizing an acrylic monomer containing a covalent bonding group such as hydroxyl, amine or carboxyl, for example, hydroxyethylmethacrylate, with an addition polymerizable fluorescent comonomer such as dansyl allyl amine. A lectin or antibody is bound to the covalent site to provide cell specificity. When the microspheres are added to a cell suspension the marked microspheres will specifically label a cell membrane by binding to a specific receptor site thereon. The labeled membrane can then be detected by fluorescence of the fluorescent monomer.

  9. In-vitro and in-vivo evaluation of repaglinide loaded floating microspheres prepared from different viscosity grades of HPMC polymer

    PubMed Central

    Sharma, Megha; Kohli, Seema; Dinda, Agnimitra

    2015-01-01

    During the study repaglinide encapsulated floating microspheres were formulated and characterized for enhancing residence time of drug in git and thereby increasing its bioavailability. Floating microspheres of ethylcellulose (EC) and hydroxypropyl methyl cellulose (HPMC) (5 and 100 cps) were prepared by emulsion solvent diffusion technique. During process optimization various parameters were studied such as: drug: polymer ratio, polymer ratio, concentration of emulsifier and stirring speed. Selected optimized formulations were studied for SEM, entrapment, floating behavior, drug release and kinetics. In-vivo floating ability (X-ray) study and in-vivo antidiabetic activity were performed on alloxan induced diabetic rats. Microspheres prepared with different viscosity grade HPMC were spherical shaped with smooth surface. Size of microspheres was in the range of 181.1–248 μm. Good entrapment and buoyancy were observed for 12 h. X-ray image showed that optimized formulation remained buoyant for more than 6 h. Optimized formulation treated group shows significant (p < 0.01) reduction in blood glucose level as compared to pure drug treated group. Repaglinide loaded floating microspheres expected to give new choice for safe, economical and increased bioavailable formulation for effective management of NIDDM. PMID:26702263

  10. In-vitro and in-vivo evaluation of repaglinide loaded floating microspheres prepared from different viscosity grades of HPMC polymer.

    PubMed

    Sharma, Megha; Kohli, Seema; Dinda, Agnimitra

    2015-11-01

    During the study repaglinide encapsulated floating microspheres were formulated and characterized for enhancing residence time of drug in git and thereby increasing its bioavailability. Floating microspheres of ethylcellulose (EC) and hydroxypropyl methyl cellulose (HPMC) (5 and 100 cps) were prepared by emulsion solvent diffusion technique. During process optimization various parameters were studied such as: drug: polymer ratio, polymer ratio, concentration of emulsifier and stirring speed. Selected optimized formulations were studied for SEM, entrapment, floating behavior, drug release and kinetics. In-vivo floating ability (X-ray) study and in-vivo antidiabetic activity were performed on alloxan induced diabetic rats. Microspheres prepared with different viscosity grade HPMC were spherical shaped with smooth surface. Size of microspheres was in the range of 181.1-248 μm. Good entrapment and buoyancy were observed for 12 h. X-ray image showed that optimized formulation remained buoyant for more than 6 h. Optimized formulation treated group shows significant (p < 0.01) reduction in blood glucose level as compared to pure drug treated group. Repaglinide loaded floating microspheres expected to give new choice for safe, economical and increased bioavailable formulation for effective management of NIDDM. PMID:26702263

  11. Preparation and properties of polyvinyl alcohol microspheres

    SciTech Connect

    Campbell, J.H.; Grens, J.Z.; Poco, J.F.; Ives, B.H.

    1986-06-01

    Polyvinyl alcohol (PVA) microspheres, having a size range of approx.150- to 250-..mu..m diameter with 1- to 5-..mu..m wall thickness, have been fabricated using a solution droplet technique. The spheres were developed for possible use on the Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion (ICF) Program. PVA, a polymer chosen based on earlier survey work carried out at KMS Fusion, Inc., has good strength, low hydrogen permeability, is optically transparent, and water soluble. The latter property makes it safe and easy to use in our droplet generator system. A unique dual-orifice droplet generator was used to prepare the spheres. The droplet generator operating conditions and the column processing parameters were chosen using results from our 1-D model calculations as a guide. The polymer microsphere model is an extension of the model we developed to support the glass sphere production. After preparation, the spheres were physically characterized for surface quality, sphericity, wall thickness (and uniformity), and size. We also determined the buckling pressure for both uncoated and CH-coated spheres. Radiation stability to beta decay (from tritium) was evaluated by exposing the spheres to a 7-keV electron beam. The results from these and other physical property measurements are presented in this report.

  12. Effect of explosive noise on gastrointestinal transit and plasma levels of polypeptide hormones

    PubMed Central

    Mu, Zhen-Bin; Huang, Yu-Xin; Zhao, Bao-Min; Liu, Zhen-Xiong; Zhang, Bing-Hua; Wang, Qing-Li

    2006-01-01

    AIM: To investigate the effect of firing noise on gastrointestinal transit and probe its mechanism by measuring the levels of plasma polypeptide hormones. METHODS: A total of 64 SD rats were randomly divided into a control group and three stimulating groups. Firing noise of different intensity by sub-machine guns was used as inflicting factor. The effect of firing noise on liquid substance gastrointestinal transit and solid substance gastrointestinal transit was observed by measuring the ratio of carbon powder suspension transmitting and barium sticks transmitting respectively. Plasma levels of polypeptide hormones were measured by radio-immunoassay. RESULTS: The noise accelerated gastrointestinal transit of solid food by more than 80 db;and accelerated gastrointestinal transit of liquid food significantly by more than 120 db. Meantime, plasma levels of plasma motilin (MTL)(157.47±16.08; 151.90±17.08), somatostatin (SS)(513.97±88.77; 458.25±104.30), substance P (SP)(115.52±20.70; 110.28±19.96) and vasoactive intestinal peptide (VIP) (214.21±63.17; 251.76±97.24) remarkably changed also. CONCLUSION: Within a certain intensity range, the firing noise changes the levels of rat plasma gastrointestinal hormones, but the gastrointestinal transit is still normal. Beyond the range, the noise induces plasma hormone levels disturbance and gastrointestinal transit disorder. PMID:16610038

  13. An Improvement of the Efficacy of Moxifloxacin HCl for the Treatment of Bacterial Keratitis by the Formulation of Ocular Mucoadhesive Microspheres

    PubMed Central

    Dandagi, Panchaxari Mallappa; Belekar, Amit Manohar; Mastiholimath, Vinayak Shivamurthy; Gadad, Anand Panchakshari; Sontake, Vivek Wamanrao; Salian, Prashant Sanjivrao

    2013-01-01

    The aim of this study was to prepare novel ocular mucoadhesive microspheres of Moxifloxacin HCl to increase its residence time on the ocular surface and to enhance its therapeutic efficacy in ocular bacterial keratitis. Microspheres were fabricated with different grades of Methocel and Sodium CMC as polymers. Microspheres were evaluated for their particle size, morphology, encapsulation efficiency, mucoadhesion, antimicrobial efficacy, and in vitro drug release studies. In vivo studies were carried out for the promising formulation on eyes of albino rabbits by inducing bacterial keratitis. A sterile microspheres suspension in light mineral oil was applied to infected eyes twice a day. A marketed conventional eye drop was used as a positive control. Eyes were examined daily for improvement of clinical signs of bacterial keratitis by an ophthalmologist. The average particle size of microspheres was found to be less than 80 μm. Methocel microspheres were found to have a smoother surface than Sodium CMC. Entrapment efficiency was enhanced with an increased polymer concentration and viscosity. The formulation containing Methocel K100M with a drug: polymer ratio of 1:2 exerted longer corneal and conjunctival mucoadhesion time of 8.45±0.15 h and 9.40±0.53 h respectively. In vitro release of Moxifloxacin HCl from microspheres was retarded with increased viscosity and concentration of polymers, and was controlled by diffusion as well as polymer relaxation. All formulations showed comparable antimicrobial activity in comparison with conventional marketed eye drops. The formulation containing Methocel K100M with a drug: polymer ratio of 1:2 was found to be a promising formulation and was used for the in vivo studies. The in vivo studies revealed that microspheres demonstrated significantly lower clinical scores and reduced the total duration of therapy than the marketed Moxifloxacin HCl eye drops. In vitro and in vivo studies showed that ocular mucoadhesive microspheres of

  14. Polycrystalline metasurface perfect absorbers fabricated using microsphere photolithography.

    PubMed

    Qu, Chuang; Kinzel, Edward C

    2016-08-01

    Microsphere photolithography (MPL) is a practical, cost-effective nanofabrication technique. It uses self-assembled microspheres in contact with the photoresist as microlenses. The microspheres focus incident light to a sub-diffraction limited array of photonic jets in the photoresist. This Letter explores the MPL technique to pattern metal-insulator-metal metasurfaces with near-perfect absorption at mid-wave infrared (MWIR) frequencies. Experimental results are compared to electromagnetic simulations of both the exposure process and the metasurface response. The microsphere self-assembly technique results in a polycrystalline metasurface; however, the metal-insulator-metal structure is shown to be defect tolerant. While the MPL approach imposes geometric constraints on the metasurface design, once understood, the technique can be used to create functional devices. In particular, the ability to tune the resonant wavelength with the exposure dose raises the potential of hierarchical structures.

  15. Super-focusing of center-covered engineered microsphere.

    PubMed

    Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

    2016-01-01

    Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere. PMID:27528093

  16. Super-focusing of center-covered engineered microsphere.

    PubMed

    Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

    2016-01-01

    Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere.

  17. Super-focusing of center-covered engineered microsphere

    NASA Astrophysics Data System (ADS)

    Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

    2016-08-01

    Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere.

  18. Super-focusing of center-covered engineered microsphere

    PubMed Central

    Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

    2016-01-01

    Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere. PMID:27528093

  19. Polycrystalline metasurface perfect absorbers fabricated using microsphere photolithography.

    PubMed

    Qu, Chuang; Kinzel, Edward C

    2016-08-01

    Microsphere photolithography (MPL) is a practical, cost-effective nanofabrication technique. It uses self-assembled microspheres in contact with the photoresist as microlenses. The microspheres focus incident light to a sub-diffraction limited array of photonic jets in the photoresist. This Letter explores the MPL technique to pattern metal-insulator-metal metasurfaces with near-perfect absorption at mid-wave infrared (MWIR) frequencies. Experimental results are compared to electromagnetic simulations of both the exposure process and the metasurface response. The microsphere self-assembly technique results in a polycrystalline metasurface; however, the metal-insulator-metal structure is shown to be defect tolerant. While the MPL approach imposes geometric constraints on the metasurface design, once understood, the technique can be used to create functional devices. In particular, the ability to tune the resonant wavelength with the exposure dose raises the potential of hierarchical structures. PMID:27472578

  20. Preparation of microspheres by an emulsification-complexation method.

    PubMed

    Kim, Jin-Chul; Song, Myeong-Eun; Lee, Eun-Joo; Park, Seung-Kyu; Rang, Moon-Jeong; Ahn, Ho-Jeong

    2002-04-01

    Microspheres were prepared by complexation of a cationic polymer, polyquaternium-24, and an anionic surfactant, sodium lauryl sulfate (SLS). The cationic polymer solution was emulsified in dimethylsiloxane to give water in silicone emulsion (W/Si), and it was used as a template for the formation of microspheres. The emulsion was dispersed into the SLS solution. In this process, two kinds of droplets, silicone dropletes and microspheres composed of the cationic polymer and SLS, were formed, evidenced by X-ray energy dispersive spectra. The mean diameter of the microspheres was reduced from 105.7 to 64.8 mum as the stirring rate for W/Si preparation increased from 300 to 1000 rpm. It is believed that water droplets in W/Si emulsion, when exposed to SLS solution, could be solidified by the complexation of the cationic polymer and the anionic surfactant.

  1. Super-Resolution Real Imaging in Microsphere-Assisted Microscopy

    PubMed Central

    Wang, Feifei; Li, Yi; Jia, Boliang; Liu, Lianqing; Li, Wen Jung

    2016-01-01

    Microsphere-assisted microscopy has received a lot of attention recently due to its simplicity and its capability to surpass the diffraction limit. However, to date, sub-diffraction-limit features have only been observed in virtual images formed through the microspheres. We show that it is possible to form real, super-resolution images using high-refractive index microspheres. Also, we report on how changes to a microsphere’s refractive index and size affect image formation and planes. The relationship between the focus position and the additional magnification factor is also investigated using experimental and theoretical methods. We demonstrate that such a real imaging mode, combined with the use of larger microspheres, can enlarge sub-diffraction-limit features up to 10 times that of wide-field microscopy’s magnification with a field-of-view diameter of up to 9 μm. PMID:27768774

  2. Preparation of microspheres by an emulsification-complexation method.

    PubMed

    Kim, Jin-Chul; Song, Myeong-Eun; Lee, Eun-Joo; Park, Seung-Kyu; Rang, Moon-Jeong; Ahn, Ho-Jeong

    2002-04-01

    Microspheres were prepared by complexation of a cationic polymer, polyquaternium-24, and an anionic surfactant, sodium lauryl sulfate (SLS). The cationic polymer solution was emulsified in dimethylsiloxane to give water in silicone emulsion (W/Si), and it was used as a template for the formation of microspheres. The emulsion was dispersed into the SLS solution. In this process, two kinds of droplets, silicone dropletes and microspheres composed of the cationic polymer and SLS, were formed, evidenced by X-ray energy dispersive spectra. The mean diameter of the microspheres was reduced from 105.7 to 64.8 mum as the stirring rate for W/Si preparation increased from 300 to 1000 rpm. It is believed that water droplets in W/Si emulsion, when exposed to SLS solution, could be solidified by the complexation of the cationic polymer and the anionic surfactant. PMID:16290495

  3. BIOCOMPATIBLE FLUORESCENT MICROSPHERES: SAFE PARTICLES FOR MATERIAL PENETRATION STUDIES

    SciTech Connect

    Farquar, G; Leif, R

    2009-07-15

    Biocompatible polymers with hydrolyzable chemical bonds have been used to produce safe, non-toxic fluorescent microspheres for material penetration studies. The selection of polymeric materials depends on both biocompatibility and processability, with tailored fluorescent properties depending on specific applications. Microspheres are composed of USFDA-approved biodegradable polymers and non-toxic fluorophores and are therefore suitable for tests where human exposure is possible. Micropheres were produced which contain unique fluorophores to enable discrimination from background aerosol particles. Characteristics that affect dispersion and adhesion can be modified depending on use. Several different microsphere preparation methods are possible, including the use of a vibrating orifice aerosol generator (VOAG), a Sono-Tek atomizer, an emulsion technique, and inkjet printhead. Applications for the fluorescent microspheres include challenges for biodefense system testing, calibrants for biofluorescence sensors, and particles for air dispersion model validation studies.

  4. X- And y-axis driver for rotating microspheres

    DOEpatents

    Weinstein, Berthold W.

    1979-01-01

    Apparatus for precise control of the motion and position of microspheres for examination of their interior and/or exterior. The apparatus includes an x- and y-axis driver mechanism controlled, for example, by a minicomputer for selectively rotating microspheres retained between a pair of manipulator arms having flat, smooth end surfaces. The driver mechanism includes an apertured plate and ball arrangement which provided for coupled equal and opposite movement of the manipulator arms in two perpendicular directions.

  5. ENCAPSULATION OF PALLADIUM IN POROUS WALL HOLLOW GLASS MICROSPHERES

    SciTech Connect

    Heung, L; George Wicks, G; Ray Schumacher, R

    2008-04-09

    A new encapsulation method was investigated in an attempt to develop an improved palladium packing material for hydrogen isotope separation. Porous wall hollow glass microspheres (PWHGMs) were produced by using a flame former, heat treating and acid leaching. The PWHGMs were then filled with palladium salt using a soak-and-dry process. The palladium salt was reduced at high temperature to leave palladium inside the microspheres.

  6. Characterization of Fluorescent Polystyrene Microspheres for Advanced Flow Diagnostics

    NASA Technical Reports Server (NTRS)

    Maisto, Pietro M. F.; Lowe, K. Todd; Byun, Guibo; Simpson, Roger; Vercamp, Max; Danley, Jason E.; Koh, Brian; Tiemsin, Pacita; Danehy, Paul M.; Wohl, Christopher J.

    2013-01-01

    Fluorescent dye-doped polystyrene latex microspheres (PSLs) are being developed for velocimetry and scalar measurements in variable property flows. Two organic dyes, Rhodamine B (RhB) and dichlorofluorescence (DCF), are examined to assess laser-induced fluorescence (LIF) properties for flow imaging applications and single-shot temperature measurements. A major interest in the current research is the application of safe dyes, thus DCF is of particular interest, while RhB is used as a benchmark. Success is demonstrated for single-point laser Doppler velocimetry (LDV) and also imaging fluorescence, excited via a continuous wave 2 W laser beam, for exposures down to 10 ms. In contrast, when exciting with a pulsed Nd:YAG laser at 200 mJ/pulse, no fluorescence was detected, even when integrating tens of pulses. We show that this is due to saturation of the LIF signal at relatively low excitation intensities, 4-5 orders of magnitude lower than the pulsed laser intensity. A two-band LIF technique is applied in a heated jet, indicating that the technique effectively removes interfering inputs such as particle diameter variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about +/-12.5 C precision, while future improvements in dye temperature sensitivity and signal quality may enable single-shot temperature measurements with sub-degree precision.

  7. Collective interaction of microscale matters in natural analogy: human cancer cells vs. microspheres

    NASA Astrophysics Data System (ADS)

    Ahn, Sungsook; Lee, Sang Joon; Postech Team

    2014-11-01

    Collective behaviors have been considered both in living and lifeless things as a natural phenomenon. During the ordering process, a sudden and spontaneous transition is typically generated between an order and a disorder according to the population density of interacting elements. In a cellular level collective behavior, the cells are distributed in the characteristic patterns according to the population density and the mutual interaction of the individual cells undergo density-dependent diffusive motion. On the other hand, density-controlled surface-modified hollow microsphere suspension induces an overpopulation via buoyancy which provides a driving force to induce an assembly. The collective behaviors of the cells and microspheres in a designed liquid medium are explained in terms of the deviation from the interparticle distance distribution and the induced strength to organize the particle position in a specific distance range. as a result, microscale particulate matters exhibit high resemblance in their pair correlation and dynamical heterogeneity in the intermediate range between a single individual and an agglomerate. Therefore, it is suggested that biological systems are analogically explained to be dominated by physically interactive aspects.

  8. Quality control in gastrointestinal surgery.

    PubMed

    Ramírez-Barba, Ector Jaime; Arenas-Moya, Diego; Vázquez-Guerrero, Arturo

    2011-01-01

    We analyzed the Mexican legal framework, identifying the vectors that characterize quality and control in gastrointestinal surgery. Quality is contemplated in the health protection rights determined according to the Mexican Constitution, established in the general health law and included as a specific goal in the actual National Development Plan and Health Sector Plan. Quality control implies planning, verification and application of corrective measures. Mexico has implemented several quality strategies such as certification of hospitals and regulatory agreements by the General Salubrity Council, creation of the National Health Quality Committee, generation of Clinical Practice Guidelines and the Certification of Medical Specialties, among others. Quality control in gastrointestinal surgery must begin at the time of medical education and continue during professional activities of surgeons, encouraging multidisciplinary teamwork, knowledge, abilities, attitudes, values and skills that promote homogeneous, safe and quality health services for the Mexican population. PMID:22169378

  9. Advances in upper gastrointestinal endoscopy

    PubMed Central

    Graham, David G.; Banks, Matthew R.

    2015-01-01

    The rapidly moving technological advances in gastrointestinal endoscopy have enhanced an endoscopist’s ability to diagnose and treat lesions within the gastrointestinal tract. The improvement in image quality created by the advent of high-definition and magnification endoscopy, alongside image enhancement, produces images of superb quality and detail that empower the endoscopist to identify important lesions that have previously been undetectable. Additionally, we are now seeing technologies emerge, such as optical coherence tomography and confocal laser endomicroscopy, that allow the endoscopist to visualize individual cells on a microscopic level and provide a real time, in vivo histological assessment. Within this article we discuss these technologies, as well as some of the results from their early use in clinical studies. PMID:26918137

  10. Development and characterization of fast responding pressure sensitive microspheres.

    PubMed

    Kimura, Fletcher; Rodriguez, Miguel; McCann, Jesse; Carlson, Brenden; Dabiri, Dana; Khalil, Gamal E; Callis, James B; Xia, Younan; Gouterman, Martin

    2008-07-01

    The response times of pressure sensitive paint (PSP) and pressure sensitive microspheres to passing shockwaves were measured to investigate their ability to accurately determine pressure changes in unsteady flows. The PSPs tested used platinum tetra(pentafluorophenyl)porphine (PtTFPP), platinum octaethylporphine (PtOEP), and a novel set of osmium-based organometallic complexes as pressure sensitive luminophors incorporated into polymer matrices of dimethylsiloxane bisphenol A-polycarbonate block copolymer or polystyrene. Two types of pressure sensitive microspheres were used, the first being PtOEP-doped polystyrene microspheres (PSBeads) and the second being porous silicon dioxide microspheres containing the novel, pressure sensitive osmium complexes. Response times for the platinum-based PSPs ranged from 47.2 to 53.0 micros, while the osmium-based PSPs ranged between 37.6 and 58.9 micros. For the microspheres, 2.5 microm diameter PSBeads showed a response time of 3.15 ms, while the osmium-based silicon dioxide microspheres showed a response time ranging between 13.6 and 18.9 micros.

  11. Drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy.

    PubMed

    Floyd, J Alaina; Galperin, Anna; Ratner, Buddy D

    2016-02-01

    The grim prognosis for patients diagnosed with malignant gliomas necessitates the development of new therapeutic strategies for localized and sustained drug delivery to combat tumor drug resistance and regrowth. Here we introduce drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy (DREAM BIG therapy). DREAM BIG therapy is envisioned to deliver three chemotherapeutics, temporally staged over one year, via a bioadhesive, biodegradable spray directly to the brain surgical site after tumor excision. In this proof-of-principle article exploring key components of the DREAM BIG therapy prototype, rhodamine B (RB) encapsulated poly(lactic-co-glycolic acid) and immunoglobulin G (IgG) encapsulated poly(lactic acid) microspheres were formulated and characterized. The encapsulation efficiency of RB and IgG and the release kinetics of the model drugs from the microspheres were elucidated in addition to the release kinetics of RB from poly(lactic-co-glycolic acid) microspheres formulated in a degradable poly(N-isopropylacrylamide) solution. The successful aerosolized application onto brain tissue ex-vivo demonstrated the conformal adhesion of the RB encapsulated poly(lactic-co-glycolic acid) microspheres to the convoluted brain surface mediated by the thermoresponsive carrier, poly(N-isopropylacrylamide). These preliminary results suggest the potential of the DREAM BIG therapy for future use with multiple chemotherapeutics and microsphere types to combat gliomas at a localized site. PMID:26238392

  12. Fractionating Polymer Microspheres as Highly Accurate Density Standards.

    PubMed

    Bloxham, William H; Hennek, Jonathan W; Kumar, Ashok A; Whitesides, George M

    2015-07-21

    This paper describes a method of isolating small, highly accurate density-standard beads and characterizing their densities using accurate and experimentally traceable techniques. Density standards have a variety of applications, including the characterization of density gradients, which are used to separate objects in a variety of fields. Glass density-standard beads can be very accurate (±0.0001 g cm(-3)) but are too large (3-7 mm in diameter) for many applications. When smaller density standards are needed, commercial polymer microspheres are often used. These microspheres have standard deviations in density ranging from 0.006 to 0.021 g cm(-3); these distributions in density make these microspheres impractical for applications demanding small steps in density. In this paper, commercial microspheres are fractionated using aqueous multiphase systems (AMPS), aqueous mixture of polymers and salts that spontaneously separate into phases having molecularly sharp steps in density, to isolate microspheres having much narrower distributions in density (standard deviations from 0.0003 to 0.0008 g cm(-3)) than the original microspheres. By reducing the heterogeneity in densities, this method reduces the uncertainty in the density of any specific bead and, therefore, improves the accuracy within the limits of the calibration standards used to characterize the distributions in density.

  13. In vitro and in vivo characterization of biodegradable enoxacin microspheres.

    PubMed

    Abazinge, M; Jackson, T; Yang, Q; Owusu-Ababio, G

    2000-03-01

    The in vitro release and plasma concentration profiles of sustained release enoxacin microspheres intended for the treatment of bone and systemic infections due to sensitive strains of bacteria were investigated. Microspheres of enoxacin were prepared by using poly(glycolic acid-co-DL-lactic acid) (PLGA) by the emulsion solvent evaporation technique and characterized by in vitro release in an incubator, and in vivo release in the rat subcutaneous model. The microspheres were spherical in nature, and particle size range had a significant influence on the in vitro release. The enoxacin plasma concentration 2 h after the administration of treatments was two-fold higher in animals who received the free drug compared with those who received microspheres of size range 125-250 microm. The plasma of animals who received the free drug was depleted of enoxacin by the end of the first day. However, the plasma concentration of enoxacin in the animals who received microspheres was sustained above 0.5 microg/ml for about 8 days. The results show that biodegradable microspheres of enoxacin can be prepared which release the antibiotic in vivo for days following a subcutaneous administration. This should provide a means for the sustained treatment of infections due to sensitive strains of bacteria.

  14. Abiogenic Photophosphorylation of ADP to ATP Sensitized by Flavoproteinoid Microspheres

    NASA Astrophysics Data System (ADS)

    Kolesnikov, Michael P.; Telegina, Taisiya A.; Lyudnikova, Tamara A.; Kritsky, Mikhail S.

    2008-06-01

    A model for abiogenic photophosphorylation of ADP by orthophosphate to yield ATP was studied. The model is based on the photochemical activity of flavoproteinoid microspheres that are formed by aggregation in an aqueous medium of products of thermal condensation of a glutamic acid, glycine and lysine mixture (8:3:1) and contain, along with amino acid polymers (proteinoids), abiogenic isoalloxazine (flavin) pigments. Irradiation of aqueous suspensions of microspheres with blue visible light or ultraviolet in the presence of ADP and orthophosphate resulted in ATP formation. The yield of ATP in aerated suspensions was 10 20% per one mol of starting ADP. Deaeration reduced the photophosphorylating activity of microspheres five to 10 times. Treatment of aerated microsphere suspensions with superoxide dismutase during irradiation partially suppressed ATP formation. Deaerated microspheres restored completely their photophosphorylating activity after addition of hydrogen peroxide to the suspension. The photophosphorylating activity of deaerated suspensions of flavoproteinoid microspheres was also recovered by introduction of Fe3+-cytochrome c, an electron acceptor alternative to oxygen. On the basis of the results obtained, a chemical mechanism of phosphorylation is proposed in which the free radical form of reduced flavin sensitizer left( {{text{FlH}}^ bullet } right) and ADP are involved.

  15. Gastrointestinal endoscopy: infection and disinfection.

    PubMed Central

    O'Connor, H J; Axon, A T

    1983-01-01

    The past decade has seen the development of an array of complex flexible fibreoptic instruments for gastrointestinal (GI) endoscopy, and an increasing use of these for diagnostic and therapeutic purposes. It has been recognised more recently that the use of contaminated endoscopic equipment can lead to serious and occasionally fatal infections. Infection with a wide variety of micro-organisms has been reported following oesophago-gastroduodenoscopy (OGD) and endoscopic retrograde cholangio-pancreatography (ERCP). PMID:6414894

  16. Erlotinib and gefitinib treatments of the lung cancer in an elderly patient result in gastrointestinal bleeding

    PubMed Central

    Bai, Hongmei; Liu, Qing; Shi, Maowei; Zhang, Jing

    2013-01-01

    Lung cancer is currently one of the leading causes of the cancer-related deaths in the world. Erlotinib and Gefitinib are inhibitors of human epidermal growth factor receptor-1 and the epidermal growth factor receptor tyrosine kinase. The most common adverse events for erlotinib and gefitinib were mild to moderate skin toxicity (rash, itching, and dry skin), gastrointestinal reactions (diarrhea and nausea), and fatigue. Erlotinib induced gastrointestinal bleeding is rare, and dose-related. We are reporting a lung cancer patient who received erlotinib and gefitinib. The patient was sensitive to drug and tumor growth was inhibited. However, adverse reactions appeared as drug treatment continued, including gastrointestinal bleeding. PMID:24353736

  17. Gastrointestinal Diseases in Pregnancy: Nausea, Vomiting, Hyperemesis Gravidarum, Gastroesophageal Reflux Disease, Constipation, and Diarrhea.

    PubMed

    Body, Cameron; Christie, Jennifer A

    2016-06-01

    Many disorders of the gastrointestinal tract are common in pregnancy. Elevated levels of progesterone may lead to alterations in gastrointestinal motility which could contribute to nausea, vomiting, and/or GERD. Pregnancy-induced diarrhea may be due to elevated levels prostaglandins. This article reviews the normal physiologic and structural changes associated with pregnancy that could contribute to many of the common gastrointestinal complaints in pregnant patients. Additionally, the appropriate clinical and laboratory evaluations, other pathologic conditions that should be included in the differential, as well as the nonpharmacologic and pharmacologic therapies for each of these conditions is discussed. PMID:27261898

  18. TIPS to manipulate myogenesis: retention of myoblast differentiation capacity using microsphere culture.

    PubMed

    Parmar, N; Day, R M

    2015-01-01

    Cell therapy is an emerging option for regenerating skeletal muscle. Improved delivery methods for anchorage-dependent myoblasts are likely to improve integration and function of transplanted muscle cells. Highly porous microspheres, produced using thermally induced phase separation (TIPS), have features ideally suited for minimally invasive cell delivery. The purpose of this study was to investigate, for the first time, the use of TIPS microspheres as highly porous microcarriers for manipulation of human skeletal muscle myoblasts (HSMM) under defined culture conditions. HSMM cells readily attached to the surface of poly (DL-lactide-co-glycolide) (PLGA) TIPS microcarriers, where they were induced to continue proliferating or to be driven towards differentiation whilst under static-dynamic culture conditions for 7 days. Switching from proliferation medium to differentiation medium for 7 days, resulted in increased protein expression of skeletal muscle cell contractile apparatus components, MyoD and skeletal muscle myosin heavy chain, compared with cells cultured on conventional culture plasticware for the same duration (p < 0.001). Growth of myoblasts on the surface of the microcarriers and their migration following simulated delivery, caused no change to the proliferative capacity of cells over 7 days. Results from this study demonstrate that TIPS microspheres provide an ideal vehicle for the expansion and delivery of myoblasts for therapeutic applications. Transplantation of myoblasts anchored to a substrate, rather than in suspension, will reduce the amount of ex vivo manipulation required during preparation of the product and allows cells to be delivered in a more natural state. This will improve the ability to control cell dosage and increase the likelihood of efficacy.

  19. Diet and upper gastrointestinal malignancies.

    PubMed

    Abnet, Christian C; Corley, Douglas A; Freedman, Neal D; Kamangar, Farin

    2015-05-01

    Diet is believed to modulate cancer risk and this relationship has been widely studied in the gastrointestinal tract. Observational epidemiologic studies have provided most of the evidence about the effects of diet on cancer risk because clinical trials to determine nutritional exposures are often impossible, impractical, or unaffordable. Although a few foods or nutrients are thought to protect against specific types of cancer, it seems clear that the strength and even direction of dietary associations (increasing or decreasing risk) is organ-site- and even histology-specific, along the gastrointestinal tract. Although some hypotheses are supported by a substantial body of observational data (drinking hot maté [an infusion of the herb Ilex Paraguarensis] contributes to esophageal cancer), there are not much data to support others. We discuss some highly touted hypotheses and draw interim conclusions about what is known and what could be done to improve the level of evidence. The complex nature of diet and its associations can be productively investigated with disease-specific studies. However, public health recommendations for normal-risk individuals regarding diet and gastrointestinal cancer should probably emphasize the importance of eating for overall health rather than eating specific foods to reduce risk for specific cancers. PMID:25680671

  20. Diet and Upper Gastrointestinal Malignancies

    PubMed Central

    Abnet, Christian C.; Corley, Douglas A.; Freedman, Neal D.; Kamangar, Farin

    2015-01-01

    Diet is believed to modulate cancer risk and this relationship has been widely studied in the gastrointestinal tract. Observational epidemiologic studies have provided most of the evidence for the effects of diet on cancer risk, because clinical trials to determine nutritional exposures are often impossible, impractical, or unaffordable. Although a few foods or nutrients are thought to protect against specific types of cancer, it seems clear that the strength and even direction of dietary associations (increasing or decreasing risk) is organ site- and even histology-specific, along the gastrointestinal tract. Although some hypotheses are supported by a substantial body of observational data (drinking hot maté contributes to esophageal cancer), there is not much data to support others. We discuss some highly touted hypotheses and draw interim conclusions about what is known, and what could be done to improve the level of evidence. The complex nature of diet and its associations can be productively investigated with disease-specific studies. However, public health recommendations for normal-risk individuals regarding diet and gastrointestinal cancer should probably emphasize the importance of eating for overall health, rather than eating specific foods to reduce risk for specific cancers. PMID:25680671

  1. Microspheres and Nanotechnology for Drug Delivery.

    PubMed

    Jóhannesson, Gauti; Stefánsson, Einar; Loftsson, Thorsteinn

    2016-01-01

    Ocular drug delivery to the posterior segment of the eye can be accomplished by invasive drug injections into different tissues of the eye and noninvasive topical treatment. Invasive treatment involves the risks of surgical trauma and infection, and conventional topical treatments are ineffective in delivering drugs to the posterior segment of the eye. In recent years, nanotechnology has become an ever-increasing part of ocular drug delivery. In the following, we briefly review microspheres and nanotechnology for drug delivery to the eye, including different forms of nanotechnology such as nanoparticles, microparticles, liposomes, microemulsions and micromachines. The permeation barriers and anatomical considerations linked to ocular drug delivery are discussed and a theoretical overview on drug delivery through biological membranes is given. Finally, in vitro, in vivo and human studies of x03B3;-cyclodextrin nanoparticle eyedrop suspensions are discussed as an example of nanotechnology used for drug delivery to the eye. PMID:26501994

  2. Microspheres and Nanotechnology for Drug Delivery.

    PubMed

    Jóhannesson, Gauti; Stefánsson, Einar; Loftsson, Thorsteinn

    2016-01-01

    Ocular drug delivery to the posterior segment of the eye can be accomplished by invasive drug injections into different tissues of the eye and noninvasive topical treatment. Invasive treatment involves the risks of surgical trauma and infection, and conventional topical treatments are ineffective in delivering drugs to the posterior segment of the eye. In recent years, nanotechnology has become an ever-increasing part of ocular drug delivery. In the following, we briefly review microspheres and nanotechnology for drug delivery to the eye, including different forms of nanotechnology such as nanoparticles, microparticles, liposomes, microemulsions and micromachines. The permeation barriers and anatomical considerations linked to ocular drug delivery are discussed and a theoretical overview on drug delivery through biological membranes is given. Finally, in vitro, in vivo and human studies of x03B3;-cyclodextrin nanoparticle eyedrop suspensions are discussed as an example of nanotechnology used for drug delivery to the eye.

  3. Chitosan Microspheres in Novel Drug Delivery Systems

    PubMed Central

    Mitra, Analava; Dey, Baishakhi

    2011-01-01

    The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

  4. Microsphere size influences the foreign body reaction.

    PubMed

    Zandstra, J; Hiemstra, C; Petersen, A H; Zuidema, J; van Beuge, M M; Rodriguez, S; Lathuile, A A; Veldhuis, G J; Steendam, R; Bank, R A; Popa, E R

    2014-01-01

    Biodegradable poly-(DL-lactide-co-glycolide) (PLGA) microspheres (MSP) are attractive candidate vehicles for site-specific or systemic sustained release of therapeutic compounds. This release may be altered by the host's foreign body reaction (FBR), which is dependent on the characteristics of the implant, e.g. chemistry, shape or size. In this study, we focused on the characterisation of the influence of MSP size on the FBR. To this end we injected monodisperse MSP of defined size (small 5.8 µm, coefficient of variance (CV) 14 % and large 29.8 µm, CV 4 %) and polydisperse MSP (average diameter 34.1 µm, CV 51 %) under the skin of rats. MSP implants were retrieved at day 7, 14 and 28 after transplantation. The FBR was studied in terms of macrophage infiltration, implant encapsulation, vascularisation and extracellular matrix deposition. Although PLGA MSP of all different sizes demonstrated excellent in vitro and in vivo biocompatibility, significant differences were found in the characteristics of the FBR. Small MSP were phagocytosed, while large MSP were not. Large MSP occasionally elicited giant cell formation, which was not observed after implantation of small MSP. Cellular and macrophage influx and collagen deposition were increased in small MSP implants compared to large MSP. We conclude that the MSP size influences the FBR and thus might influence clinical outcome when using MSP as a drug delivery device. We propose that a rational choice of MSP size can aid in optimising the therapeutic efficacy of microsphere-based therapies in vivo. PMID:25350249

  5. Histamine H4 receptors in the gastrointestinal tract

    PubMed Central

    Deiteren, A; De Man, J G; Pelckmans, P A; De Winter, B Y

    2015-01-01

    Histamine is a well-established mediator involved in a variety of physiological and pathophysiological mechanisms and exerts its effect through activation of four histamine receptors (H1–H4). The histamine H4 receptor is the newest member of this histamine receptor family, and is expressed throughout the gastrointestinal tract as well as in the liver, pancreas and bile ducts. Functional studies using a combination of selective and non-selective H4 receptor ligands have rapidly increased our knowledge of H4 receptor involvement in gastrointestinal processes both under physiological conditions and in models of disease. Strong evidence points towards a role for H4 receptors in the modulation of immune-mediated responses in gut inflammation such as in colitis, ischaemia/reperfusion injury, radiation-induced enteropathy and allergic gut reactions. In addition, data have emerged implicating H4 receptors in gastrointestinal cancerogenesis, sensory signalling, and visceral pain as well as in gastric ulceration. These studies highlight the potential of H4 receptor targeted therapy in the treatment of various gastrointestinal disorders such as inflammatory bowel disease, irritable bowel syndrome and cancer. PMID:25363289

  6. Interpretability of the PedsQL gastrointestinal symptoms scales and gastrointestinal worry scales in pediatric patients with functional and organic gastrointestinal diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study investigates the clinical interpretability of the Pediatric Quality of Life Inventor (PedsQL) Gastrointestinal Symptoms Scales and Worry Scales in pediatric patients with functional gastrointestinal disorders or organic gastrointestinal diseases in comparison with healthy controls....

  7. Effect of surface roughness of chitosan-based microspheres on cell adhesion

    NASA Astrophysics Data System (ADS)

    Zan, Qingfeng; Wang, Chen; Dong, Limin; Cheng, Peng; Tian, Jiemo

    2008-11-01

    Microspheres are novel candidate materials for microcarriers and tissue-engineering scaffolds. Chitosan microspheres were selected as the base materials because of their excellent properties for biomedical applications. But their smooth surfaces were not adapted for cell attachment. Hence, in order to improve the roughness of chitosan microspheres, β-TCP/chitosan composite microspheres were developed. From SEM photographs, the coarse surfaces of composite microspheres were observed, there were some ceramic particles standing out of the chitosan matrix. And their roughness measured by profilometers was about 2.0 μm. Mouse MC3T3-E1 osteoblasts were seeded on the microspheres for evaluating the attachment interaction between cells and materials. According to the ESEM photographs and MTT assay, the adherence and proliferation of osteoblasts on the surfaces of modified microspheres were better than those on the chitosan microspheres, which were mainly attributed to the improved roughness of surface.

  8. Preparation of polysulfone hollow microspheres encapsulating DNA and their functional utilization.

    PubMed

    Zhao, C; Liu, X D; Nomizu, M; Nishi, N

    2004-05-01

    Polysulfone hollow microspheres encapsulating DNA were prepared using a liquid-liquid phase separation technique. The microspheres were then used to absorb a DNA-binding intercalating material--ethidium bromide. The amount of DNA encapsulated in the microspheres depended on the concentration of the DNA solution used to prepare the microspheres, and the microsphere morphology depended on both the polymer concentration and the preparation conditions. The amount of ethidium bromide in the microspheres depended mainly on the amount of encapsulated DNA, and the microsphere morphology also affected the removal of the ethidium bromide. The new method of DNA encapsulation is proposed, and the microspheres encapsulating the DNA have the potential to be used in environmental applications.

  9. Encapsulation of catalase in polyelectrolyte microspheres composed of melamine formaldehyde, dextran sulfate, and protamine.

    PubMed

    Balabushevich, N G; Zimina, E P; Larionova, N I

    2004-07-01

    Immobilization of catalase (molecular weight 240,000 daltons) in polyelectrolyte microspheres was studied. The microspheres were obtained by alternating adsorption of dextran sulfate and protamine on commercially available melamine formaldehyde cores followed by the core hydrolysis at pH 1.7. As the interior of the microspheres was filled with homogeneous matrix, the catalase distribution inside the microspheres was uniform. The quantity of entrapped catalase was dependent on the initial concentration of the enzyme and pH of solution, and the peak value was 10(8)-10(9) molecules per microsphere. It was demonstrated that catalase was entrapped in the microspheres via electrostatic and hydrophobic interactions. The catalase activity inside the microspheres increased as the quantity of enzyme decreased, which was due to the switch between diffusion and kinetic regimes of the enzymatic reaction. The microspheres could be applied for separation and concentration of high molecular weight proteins.

  10. Apparatus for washing particulate material. [Removal of silicone oil from microspheres by trichloroethylene

    DOEpatents

    Rivera, A.L.; Fowler, V.L.; Justice, G.V.

    1983-12-29

    Transport of nuclear fuel microspheres through a wash liquid is facilitated by feeding a slurry containing the microspheres into the wash liquid via a column having a vibrating tubular screen located under its lower end.

  11. Membranes for specific adsorption: immobilizing molecularly imprinted polymer microspheres using electrospun nanofibers.

    PubMed

    Büttiker, Roman; Ebert, Jürgen; Hinderling, Christian; Adlhart, Christian

    2011-01-01

    Molecularly imprinted polymer microspheres were immobilized within a polymer nanofiber membrane by electrospinning. Such membranes simplify the handling of functional microspheres and provide specific recognition capabilities for solid-phase extraction and filtration applications. In this study, microspheres were prepared by precipitation polymerization of methacrylic acid and divinylbenzene as a cross-linker with the target molecule (-)-cinchonidine and then, they were electrospun into a non-woven polyacrylonitrile nanofiber membrane. The composite membrane showed specific affinity for (-)-cinchonidine which was attributed to the functional microspheres as confirmed by Raman microscopy. The target molecule capturing capacity of the composite membrane was 5 mg/g or 25 mg/g immobilized functional microsphere. No difference in target affinity was observed between the immobilized microspheres and the free microspheres. These results reveal that electrospun composite membranes are a feasible approach to immobilizing functional microspheres.

  12. Membranes for specific adsorption: immobilizing molecularly imprinted polymer microspheres using electrospun nanofibers.

    PubMed

    Büttiker, Roman; Ebert, Jürgen; Hinderling, Christian; Adlhart, Christian

    2011-01-01

    Molecularly imprinted polymer microspheres were immobilized within a polymer nanofiber membrane by electrospinning. Such membranes simplify the handling of functional microspheres and provide specific recognition capabilities for solid-phase extraction and filtration applications. In this study, microspheres were prepared by precipitation polymerization of methacrylic acid and divinylbenzene as a cross-linker with the target molecule (-)-cinchonidine and then, they were electrospun into a non-woven polyacrylonitrile nanofiber membrane. The composite membrane showed specific affinity for (-)-cinchonidine which was attributed to the functional microspheres as confirmed by Raman microscopy. The target molecule capturing capacity of the composite membrane was 5 mg/g or 25 mg/g immobilized functional microsphere. No difference in target affinity was observed between the immobilized microspheres and the free microspheres. These results reveal that electrospun composite membranes are a feasible approach to immobilizing functional microspheres. PMID:21528654

  13. Mesoporous carbon-carbon nanotube-sulfur composite microspheres for high-areal-capacity lithium-sulfur battery cathodes.

    PubMed

    Xu, Terrence; Song, Jiangxuan; Gordin, Mikhail L; Sohn, Hiesang; Yu, Zhaoxin; Chen, Shuru; Wang, Donghai

    2013-11-13

    Lithium-sulfur (Li-S) batteries offer theoretical energy density much higher than that of lithium-ion batteries, but their development faces significant challenges. Mesoporous carbon-sulfur composite microspheres are successfully synthesized by combining emulsion polymerization and the evaporation-induced self-assembly (EISA) process. Such materials not only exhibit high sulfur-specific capacity and excellent retention as Li-S cathodes but also afford much improved tap density, sulfur content, and areal capacity necessary for practical development of high-energy-density Li-S batteries. In addition, when incorporated with carbon nanotubes (CNTs) to form mesoporous carbon-CNT-sulfur composite microspheres, the material demonstrated superb battery performance even at a high current density of 2.8 mA/cm(2), with a reversible capacity over 700 mAh/g after 200 cycles.

  14. A Radically New Method for Hydrogen Storage in Hollow Glass Microspheres

    SciTech Connect

    James E. Shelby; Matthew M. Hall; Michael J. Snyder; Peter B. Wachtel

    2009-07-13

    The primary goal of this project is to demonstrate that hydrogen gas can be rapidly extracted from hollow glass microspheres (HGMS) using a photo-induced heating effect. The results of the project demonstrate that diffusion of hydrogen is readily induced by exposure to light from an IR lamp in transition metal-doped HGMS filled to as much as 5,000 psi with hydrogen gas, which contain approximately 2.2 wt% hydrogen. Doped HGMS in conjunction with optically induced outgassing provide a solution to the traditional limitation of HGMS – i.e., the slow release of hydrogen from HGMS that are heated using a furnace. This information will also be invaluable in designing process changes for future production of HGMS able to hold higher pressures of hydrogen.

  15. Notch signaling in gastrointestinal tract (review).

    PubMed

    Katoh, Masuko; Katoh, Masaru

    2007-01-01

    Notch signaling is one of key pathways constituting the stem cell signaling network. DLL1, DLL3, DLL4, JAG1 and JAG2 with DSL domain are typical Notch ligands, while DNER, F3/Contactin and NB-3 without DSL domain are atypical Notch ligands. Notch-ligand binding to NOTCH1, NOTCH2, NOTCH3 or NOTCH4 receptor induces the receptor proteolysis by metalloprotease and gamma-secretase to release Notch intracellular domain (NICD). Typical Notch ligands transduce signals to the CSL-NICD-Mastermind complex for the maintenance of stem or progenitor (transit-amplifying) cells through transcriptional activation of HES1, HES5, HES7, HEY1, HEY2 and HEYL genes, and also to the NF-kappaB-NICD complex for the augmentation of NF-kappaB signaling. Atypical Notch ligands transduce signals to the CSL-NICD-Deltex complex for the differentiation of progenitor cells through MAG transcriptional activation. Notch signals are transduced to the canonical pathway (CSL-NICD-Mastermind signaling cascade) or the non-canonical pathway (NF-kappaB-NICD and CSL-NICD-Deltex signaling cascades) based on the expression profile of Notch ligands, Notch receptors, and Notch signaling modifiers. Canonical Notch signaling is activated in the stem or progenitor domain of gastrointestinal epithelium, such as basal layer in esophagus and lower part of the crypt in colon. Notch signaling to inhibit secretory cell differentiation is oncogenic in gastric cancer and colorectal cancer, while Notch signaling to promote keratinocyte differentiation is anti-oncogenic in esophageal squamous cell carcinoma (SCC). Single nucleotide polymorphism (SNP), epigenetic change, and genetic alteration of genes encoding Notch signaling-associated molecules will be utilized as biomarkers for gastrointestinal cancer. gamma-Secretase inhibitors, functioning as Notch signaling inhibitors, will be applied as anti-cancer drugs for gastric cancer and colorectal cancer.

  16. Three dimensional confocal microscopy of fluorescent microspheres: imaging and size determination

    NASA Astrophysics Data System (ADS)

    Rakovich, Y. P.; Yang, L.; Taylor, C. M.; Dunbar, L. A.; Mac Raighne, Aaron; Donegan, J. F.; McCabe, Eithne M.

    2005-06-01

    In this paper, we experimentally studied both the bright-field and fluorescence images of microspheres by conventional and confocal scanning polarization microscopes. A qualitative analysis have been given to show a physical picture on the imaging of the microspheres. Emission spectra from melamine formaldehyde microspheres stained with Ethidium Bromide or covered by thin shell of CdTe nanocrystals have been experimentally studied. We adopted analytical expressions describing the resonance spacing in order to determine the size of the microspheres.

  17. Formulation and in vitro evaluation of rifampicin loaded porous microspheres.

    PubMed

    Bhise, Satish Balakrishna; More, Avinash Bhanudas; Malayandi, Rajkumar

    2010-01-01

    Rifampicin (RIF) is a major component in fixed dose combination therapy for the treatment of tuberculosis. RIF has low solubility and high permeability with high dose and hence it is classified as class II drug in Biopharmaceutical Classification System (BCS). RIF has poor and variable bioavailability because of its poor solubility, acid decomposition and, drug and food interaction. The present investigation was aimed to develop RIF loaded porous microspheres as a controlled release dosage form. Eudragit based porous microspheres of RIF were prepared by emulsion solvent diffusion method. Prepared porous microspheres were evaluated for its entrapment efficacy, morphology, thermal behavior, crystalline nature, in-vitro drug release and stability in simulated gastric fluid. The entrapment efficacy of drug loaded microspheres was found to be in the range of 19.04â74.57%. Surface morphology revealed the porous and spherical structure of microspheres. Differential scanning calorimetric studies confirmed that formulation process altered the crystalline nature of RIF. In vitro drug release studies indicated that drug to polymer ratio of 2:1 showed more than 85% drug release over the period of 3 h. Stability studies in simulated gastric fluid (SGF) indicated that low relative decomposition of 18.5% was achieved with high drug to low polymer ratio of 1:4. The results obtained from the present investigation concluded that RIF loaded porous microspheres are suitable for developing oral controlled release dosage form of RIF that can prevent acid decomposition and provide better biopharmaceutical properties. Further more the microspheres can be evaluated for preventing the interaction with isoniazid, other drugs and foodstuffs.

  18. Synthesis of novel aminated cellulose microsphere adsorbent for efficient Cr(VI) removal

    NASA Astrophysics Data System (ADS)

    Yu, Tianlin; Liu, Siqi; Xu, Min; Peng, Jing; Li, Jiuqiang; Zhai, Maolin

    2016-08-01

    A novel aminated cellulose microsphere adsorbent (CVN) was successfully prepared by radiation-induced graft polymerization of vinylbenzyl chloride (VBC) onto cellulose microsphere (CMS), followed by amination. Micro-FTIR, XPS and SEM confirmed the structure of CVN. The adsorption behavior of Cr(VI) onto CVN from solution was well fitted by the pseudo-second order kinetic model. The isothermal adsorption of Cr(VI) was observed at pH 4.68 with adsorption capacity of 129 mg/g in accordance with Langmuir thermal model, and the removal of Cr(VI) from solution could be 91% at a low amount (20 mg) of adsorbent. The best pH for adsorption of Cr(VI) was nearly 3.08, and with the increasing of temperature, the adsorption capacity of Cr(VI) increased. XPS analysis confirmed the adsorption mechanism of Cr(VI) was ion-exchange mechanism, while common co-ions such as Na+, Mg2+, Cu2+, Ca2+, Zn2+, Ni2+, Cl-, NO3- has no significant effect on the adsorption capacity of Cr(VI), and the Cr(VI) removal of 80% still could be obtained compared with that of fresh CVN adsorbent. Finally, spent CVN could be regenerated under 2 mol/L NaCl. The work indicated that aminated cellulose adsorbent could be prepared successfully by radiation-induced grafting and amination and CVN is a promising bio-adsorbent in the removing Cr(VI) from waste water.

  19. Shape changes in isolated outer hair cells: measurements with attached microspheres.

    PubMed

    Zajic, G; Schacht, J

    1991-04-01

    Shape changes can be induced in isolated outer hair cells by various stimuli and quantified from digitized video-images. While overall changes in length between base and apex are easily measured, changes in defined segments of the cell require fixed landmarks on the cell body. The problem of locating such landmarks makes it difficult to assess if a change in length is uniform or largely confined to a particular segment of the cell. This information is important in identifying the location of a contractile apparatus and the elucidation of mechanisms of motility. We demonstrate here that microspheres can serve as reference points for such measurements. By attaching microspheres to cells we determined that, when outer hair cells increased their volume upon K(+)-depolarization, their middle segment shortened more significantly (14 +/- 6%) than either the basal (10 +/- 5%) or apical section (7 +/- 6%; P less than 0.01). In contrast, when cortical contractions were induced by elevating intracellular Ca2+, the elongation of the cells was more pronounced in their basal (8 +/- 2%) than their apical (6 +/- 2%; P = 0.06) or middle region (6 +/- 3%). This study provides further insight into the mechanisms of shape changes in isolated outer hair cells and illustrates a method to analyze localized changes in the absence of internal landmarks.

  20. Hypoxic radioprotection by temporary intestinal ischemia: degradable starch microsphere embolization in the cat

    SciTech Connect

    Lote, K.

    1981-11-01

    Temporary small intestinal ischemia was induced by mesenteric arteriolar embolization of degradable starch microspheres in cats. During ischemia, the small intestine received a surface dose of 7 Gy 200 kV x-ray irradiation. One group of animals also had received 7 Gy to the intact abdomen 72 hr earlier. The risk of thrombosis in small intestinal vessels during or after starch microsphere-induced ischemia combined with irradiation was evaluated by monitoring superior mesenteric arterial blood flow, by determination of blood platelets, fibrinogen, and factor VIII consumed across the mesenteric vascular bed, and by histologic examination of small intestinal vessels. Vascular integrity was inferred from intact response to isoproterenol and vasopressin after the combined trauma of ischemia and irradiation. No signs of thrombosis were detected in small intestinal vessels after temporary ischemia and irradiation. Hypoxic radioprotection of the small intestine in the cat can thus be achieved by mesenteric arterial microembolization of degradable starch spheres without evidence of thrombotic complications or significant vascular damage.