Relevant bibliographies by topics / In vitro gastrointestinal assay

Academic literature on the topic 'In vitro gastrointestinal assay'

Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

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Journal articles on the topic "In vitro gastrointestinal assay"

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Amano, Yuto, Hiroshi Honda, Yuko Nukada, Naohiro Ikeda, Masayuki Yamane, Koji Nakano, Akiyo Kameyama, and Osamu Morita. "Safety Pharmacological Evaluation of the Coffee Component, Caffeoylquinic Acid, and Its Metabolites, Using Ex Vivo and In Vitro Profiling Assays." Pharmaceuticals 12, no. 3 (July 17, 2019): 110. http://dx.doi.org/10.3390/ph12030110.

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Although coffee components have gained interest for use as pharmaceuticals, little is known about their safety pharmacological effects. Hence, we aimed to evaluate the safety pharmacological effects of a chlorogenic acid (CGA)-related compound contained in coffee, 5-O-caffeoylquinic acid (5-CQA), and its metabolites, 5-O-feruloylquinic acid (5-FQA), caffeic acid (CA), and ferulic acid (FA). Langendorff perfused heart assay, electrophysiological assay of acute rat hippocampal slices, and in vitro Magnus assay of gastrointestinal tracts were conducted at 1–100 µM. Moreover, in vitro profiling assays against 38 major targets were conducted. In the Langendorff assay, no significant adverse effects were observed. In the electrophysiological assay, although epileptiform discharge rates were increased at 10 µM CA with 4-aminopyridine, and area under the curve (AUC) and number of population spike were increased at 10 µM FA with bicuculline, dose dependency was not confirmed, and no significant changes were observed at 1 µM and by CGAs alone. In the Magnus assay, a slight increase in contraction activity was observed at >1 µM FA in the stomach fundi and 100 µM 5-CQA in the ileum, suggesting enterokinesis promotion. No significant interactions were observed in the in vitro profiling assays. Therefore, CGAs could have a fundamental function as safe pharmaceuticals.
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Podsędek, Anna, Małgorzata Redzynia, Elżbieta Klewicka, and Maria Koziołkiewicz. "Matrix Effects on the Stability and Antioxidant Activity of Red Cabbage Anthocyanins under Simulated Gastrointestinal Digestion." BioMed Research International 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/365738.

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Red cabbage is, among different vegetables, one of the major sources of anthocyanins. In the present study an in vitro digestion method has been used to assay the influence of the physiological conditions in the stomach and small intestine, as well as faecal microflora on anthocyanins stability in red cabbage and anthocyanin-rich extract. The recovery of anthocyanins during in vitro gastrointestinal digestion was strongly influenced by food matrix. The results showed that other constituents present in cabbage enhanced the stability of anthocyanins during the digestion. The amount of anthocyanins (HPLC method) and antioxidant capacity (ABTS and FRAP assays) strongly decreased after pancreatic-bile digestion in both matrices but total phenolics content (Folin-Ciocalteu assay) in these digestions was higher than in initial samples. Incubation with human faecal microflora caused further decline in anthocyanins content. The results obtained suggest that intact anthocyanins in gastric and products of their decomposition in small and large intestine may be mainly responsible for the antioxidant activity and other physiological effects after consumption of red cabbage.
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Jovanović, Miloš, Zorica Drinić, Dubravka Bigović, Ana Alimpić-Aradski, Sonja Duletić-Laušević, and Katarina Šavikin. "In vitro antineurodegenerative activity and in silico predictions of blood-brain barrier penetration of Helichrysum plicatum flower extract." Lekovite sirovine, no. 40 (2020): 45–51. http://dx.doi.org/10.5937/leksir2040045j.

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This study aimed to assess the antineurodegenerative and antioxidant activity of Helichrysum plicatum flower extract, as well as to identify extract ingredients with acceptable pharmacokinetic parameters such as gastrointestinal absorption, blood-brain barrier permeation, and P-glycoprotein-mediated effusion for optimal therapeutic brain exposure. Antioxidant activity was evaluated by ABTS, FRAP, and b-carotene bleaching assays, while antineurodegenerative activity was tested using acetylcholinesterase (AChE) and tyrosinase (TYR) inhibitory activity assays. In the ABTS test, the dry extract at the highest applied concentration (500 µg/mL) showed better or similar antioxidant activity compared to the standards. In the b-carotene assay, all applied concentrations of the extract showed significantly higher activity than vitamin C. No concentration-dependent activity was observed in the AChE assay, while in the TYR assay the lowest extract concentration (100 µg/mL) showed the highest percentage of inhibition (27.92 %). Pharmacokinetic parameters of compounds were predicted by in silico SwissADME online tool in accordance by the rules of drug-likeness. According to the pharmacokinetic properties, we concluded that pentoxymethoxylated flavones may represent CNS drug candidates for further studies.
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Miret, Silvia, Leo Abrahamse, and Els M. de Groene. "Comparison of in Vitro Models for the Prediction of Compound Absorption across the Human Intestinal Mucosa." Journal of Biomolecular Screening 9, no. 7 (October 2004): 598–606. http://dx.doi.org/10.1177/1087057104267162.

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Several in vitro assays have been developed to evaluate the gastrointestinal absorption of compounds. Our aim was to compare 3 of these methods: 1) the bio-mimetic artificial membrane permeability assay (BAMPA) method, which offers a high-throughput, noncellular approach to the measurement of passive transport; 2) the traditional Caco-2 cell assay, the use of which as a high-throughput tool is limited by the long cell differentiation time (21 days); and 3) The BioCoat™ high-throughput screening Caco-2 Assay System, which reduces Caco-2 cell differentiation to 3 days. The transport of known compounds (such as cephalexin, propranolol, or chlorothiazide) was studied at pH 7.4 and 6.5 in BAMPA and both Caco-2 cell models. Permeability data obtained was correlated to known values of human absorption. Best correlations ( r = 0.9) were obtained at pH 6.5 for BAMPA and at pH 7.4 for the Caco-2 cells grown for 21 days. The Caco-2 BioCoat™ HTS Caco-2 Assay System does not seem to be adequate for the prediction of absorption. The overall results indicate that BAMPA and the 21-day Caco-2 system can be complementary for an accurate prediction of human intestinal absorption.
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Nolasco, Emerson, Mike Naldrett, Sophie Alvarez, Philip E. Johnson, and Kaustav Majumder. "Bioactivity of Cooked Standard and Enriched Whole Eggs from White Leghorn and Rhode Island Red in Exhibiting In-Vitro Antioxidant and ACE-Inhibitory Effects." Nutrients 13, no. 12 (November 25, 2021): 4232. http://dx.doi.org/10.3390/nu13124232.

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Hen breed, diet enrichment, cooking methods, and gastrointestinal (GI) digestion modulates the bioaccessibility of the bioactive compounds in eggs, but their synergistic role in modulating bioactivity is still unclear. The present study evaluates the effect of hen breed, diet enrichment, and GI digestion on the cooked whole egg-derived peptides in-vitro antioxidant and antihypertensive activities. Standard and enriched whole eggs from White Leghorn (WLH) and Rhode Island Red (RIR) hens were boiled or fried and subjected to GI digestion. Antioxidant activity was measured through oxygen radical absorbance capacity (ORAC) and gastrointestinal epithelial cell-based assays, and the antihypertensive capacity by in-vitro Angiotensin-I Converting Enzyme (ACE) inhibition assay. WLH fried standard egg hydrolysate showed a high ORAC antioxidant activity but failed to show any significant antioxidant effect in the cell-based assay. No significant differences were observed in the antihypertensive activity, although enriched samples tended to have a higher ACE-inhibitory capacity. The peptide profile explained the antioxidant capacities based on antioxidant structural requirements from different peptide fractions, while previously reported antihypertensive peptides were found in all samples. The study validates the importance of physiologically relevant models and requires future studies to confirm mechanisms that yield bioactive compounds in whole egg hydrolysates.
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Rosa, S. S. Santa, F. O. Santos, H. G. Lima, I. M. A. Reis, D. S. A. Cassiano, I. J. C. Vieira, R. Braz-Filho, et al. "In vitro anthelmintic and cytotoxic activities of extracts of Persea willdenovii Kosterm (Lauraceae)." Journal of Helminthology 92, no. 6 (October 25, 2017): 674–80. http://dx.doi.org/10.1017/s0022149x17000979.

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AbstractThis study describes the effects of extracts and fractions of Persea willdenovii leaves against goat gastrointestinal nematodes and their cytotoxicity on Vero cells. The in vitro ovicidal and larvicidal activities of the crude ethanolic, hexane, ethyl acetate (EAE), butanolic and residual hydroethanolic extracts were assessed through the inhibition of egg hatching and larval motility assays. The most active extract (EAE) was then fractionated by chromatography in an open column containing silica gel, to furnish six fractions (Fr1–Fr6), which were also tested. The cytotoxicity of active extracts and fractions was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. The EAE and two fractions (Fr1 and Fr2) showed inhibitory activity in the egg hatching of gastrointestinal nematodes of goats in a concentration-dependent manner. The effective concentrations for 50% inhibition (EC50) of egg hatching were 2.3, 0.12 and 2.94 mg/ml for EAE, Fr1 and Fr2, respectively. All extracts and fractions were not effective in inhibiting 50% of motility of infective larvae. EAE and Fr2 had IC50 values (50% inhibitory concentration) of 4.95 and 2.66 mg/ml, respectively. Fr1 showed a slight cytotoxic effect (cellular inviability <30%) only after 48 h of treatment (MTT test). Gas chromatography–mass spectrometry (GC–MS) analysis showed the presence of six fatty acid ethyl esters, a fatty acid methyl ester and a long-chain ketone in the most active fraction. These constituents identified in P. willdenovii can be related to the high ovicidal activity and relatively non-toxic effect of the extracts.
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Yu, Shengwu, Anika Singh, Huiying Zhang, and David D. Kitts. "An in vitro Method to Determine Intestinal Bioavailability of Glucosamine Salt Mixture." Journal of Nutritional Health & Food Science 9, no. 1 (February 10, 2021): 1–6. http://dx.doi.org/10.15226/jnhfs.2021.001180.

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Glucosamine is an amino sugar commonly used to improve joint health. It is often available for consumers as specialized supplements, the matrixes of which are formulated with components that facilitate enhancing functionality of the bioactive glucosamine. The primary objective of this study was to determine the in vitro bioaccessibility and bioavailability of a commercial glucosamine sulphate supplement, formulated with a mineral clay mixture. We used a modified a 3-step in vitro digestion procedure that included oral, gastric, and gastrointestinal digestions to assess bioaccessibility. Bioavailability followed using a Caco2 cell permeability test. Glucosamine bioaccessibility was not affected by gastric digestion and only marginally affected by gastrointestinal digestion (e.g., > 90% recovery). Bioavailability was dramatically lower, averaging approximately 15%, but similar for both the glucosamine reference standard and clay mineral mix glucosamine formulated product. Our in vitro bioavailability measurement of glucosamine, corrected for bioaccessibility, agree with values from in vitro rodent models. We conclude that the in vitro 3-step digestion of glucosamine, used to mimic gastrointestinal digestion, followed by the Caco2 permeability assay represents an alternative method to assess digestibility and bioavailability of formulated glucosamine products. Keywords: Glucosamine; Clay Mineral Mix; Bioaccessibility; Bioavailability
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Tariq, K. A., M. Z. Chishti, F. Ahmad, A. S. Shawl, and M. A. Tantray. "Evaluation of anthelmintic activity of Iris hookeriana against gastrointestinal nematodes of sheep." Journal of Helminthology 82, no. 2 (June 2008): 135–41. http://dx.doi.org/10.1017/s0022149x08912360.

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AbstractThe objective of this study was to evaluate the anthelmintic efficacy of Iris hookeriana Linn. rhizome against gastrointestinal nematodes of sheep. A worm motility inhibition assay was used for in vitro study and a faecal egg count reduction assay was used for an in vivo study. The in vitro study revealed anthelmintic effects of crude aqueous extracts and crude ethanolic extracts on live Trichuris ovis worms (P ≤ 0.05) as evident from their paralysis and/or death at 8 h after exposure. The aqueous extracts of I. hookeriana resulted in a mean worm motility inhibition of 54.0%, while ethanolic extracts resulted in a mean worm motility inhibition of 84.6%. The mean mortality index of aqueous extracts was 0.55, while for ethanolic extracts it was 0.85. The lethal concentration 50 for aqueous extracts was 0.45 mg ml− 1 and for ethanolic extracts it was 0.15 mg ml− 1. The in vivo anthelmintic activity of aqueous and ethanolic extracts of I. hookeriana in sheep naturally infected with mixed species of gastrointestinal nematodes demonstrated a maximum (45.62%) egg count reduction in sheep treated with ethanolic extracts at 2 g kg− 1 body weight on day 10 after treatment, closely followed by ethanolic extracts at 1 g kg− 1 body weight on day 10 after treatment (43.54% egg count reduction). The aqueous extracts resulted in a maximum of 31.53% reduction in faecal egg counts on day 10 after treatment with 1 g kg− 1 body weight. Thus ethanolic extracts exhibited greater anthelmintic activity under both in vitro and in vivo conditions; this could be due to the presence of alcohol-soluble active ingredients in I. hookeriana. From the present study it can be suggested that I. hookeriana rhizome exhibited significant anthelmintic activity against gastrointestinal nematodes of sheep and has the potential to contribute to the control of gastrointestinal nematode parasites of small ruminants.
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Tomar, R. S., and S. Preet. "Evaluation of anthelmintic activity of biologically synthesized silver nanoparticles against the gastrointestinal nematode, Haemonchus contortus." Journal of Helminthology 91, no. 4 (July 4, 2016): 454–61. http://dx.doi.org/10.1017/s0022149x16000444.

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AbstractThe present study focuses on the in vitro anthelmintic activity of silver nanoparticles (AgNPs) synthesized using the aqueous extract of Azadirachta indica against Haemonchus contortus. The synthesized AgNPs were characterized by ultraviolet–visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) studies. The UV-Vis spectrum exhibited a sharp peak at 420 nm, which was validated by electron microscopy, indicating the preparation of spherical nanoparticles measuring 15–25 nm in size. The in vitro study was based on an egg hatch assay (EHA) and adult motility inhibition assays. Six concentrations of AgNPs were used for EHA, ranging from 0.00001 to 1.0 μg/ml, and a range of 1–25 μg/ml was used for adult worms. The highest concentration induced 85 ± 2.89% egg hatch inhibition. The IC50 value for EHA was 0.001 μg/ml, whereas in vitro adult H. contortus motility inhibition was produced at 7.89 μg/ml (LC50). The effectiveness of A. indica leaf extract (aqueous) was also evaluated, which showed an IC50 value for EHA of 115.67 μg/ml, while the LC50 against adult H. contortus was 588.54 μg/ml. The overall findings of the present study show that the experimental plant extract contains reducing properties for the synthesis of AgNPs which, in turn, showed potent anthelmintic properties. This is the first report where AgNPs have been tested for their anthelmintic properties in an in vitro model.
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Duque-Soto, Carmen, Alejandra Quintriqueo-Cid, Ascensión Rueda-Robles, Paz Robert, Isabel Borrás-Linares, and Jesús Lozano-Sánchez. "Evaluation of Different Advanced Approaches to Simulation of Dynamic In Vitro Digestion of Polyphenols from Different Food Matrices–A Systematic Review." Antioxidants 12, no. 1 (December 31, 2022): 101. http://dx.doi.org/10.3390/antiox12010101.

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Phenolic compounds have become interesting bioactive antioxidant compounds with implications for obesity, cancer and inflammatory gastrointestinal pathologies. As the influence of digestion and gut microbiota on antioxidant behavior is yet to be completely elucidated, and due to limitations associated to in vivo studies, dynamic in vitro gastrointestinal models have been promoted. A systematic review was conducted of different databases (PubMed, Web of Science and Scopus) following PRISMA guidelines to assess different dynamic digestion models and assay protocols used for phenolic compound research regarding bioaccesibility and interaction with colonic microbiota. Of 284 records identified, those including dynamic multicompartmental digestion models for the study of phenolic compound bioaccesibility, bioactivity and the effects of microbiota were included, with 57 studies meeting the inclusion criteria. Different conditions and experimental configurations as well as administered doses, sample treatments and microbiological assays of dynamic digestion studies on polyphenols were recorded and compared to establish their relevance for the dynamic in vitro digestion of phenolic compounds. While similarities were observed in certain experimental areas, a high variability was found in others, such as administered doses. A description of considerations on the study of the digestion of phenolic compounds is proposed to enhance comparability in research.
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Dissertations / Theses on the topic "In vitro gastrointestinal assay"

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Schneider, Naira Fernanda Zanchett. "Padronização do ensaio pampa (Parallel Artificial Membrane Permeation Assay) e avaliação in vitro da permeabilidade intestinal e cutânea de compostos de origem natural e sintética." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/94809.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2011
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O ensaio PAMPA tem demonstrado sua versatilidade desde 1998, sendo utilizado para avaliar a permeabilidade passiva transcellular de fármacos/compostos, e tem ganhado espaço por ser de baixo custo, muito rápido e por auxiliar, particularmente, na elucidação dos mecanismos de transporte, em conjunto com os ensaios que utilizam células Caco-2. Para padronizar este ensaio no Laboratório de Virologia Aplicada da UFSC, dois modelos: o PAMPA TGI, variante Double-Sink e o PAMPA Pele foram selecionados por mimetizar, respectivamente, a absorção de fármacos/compostos através do trato gastrointestinal e da pele,sendo que estas duas vias foram escolhidas pela fácil adesão do paciente aos tratamentos por via oral e tópica. Inicialmente, para demonstrar a funcionalidade dos modelos em estudo, foram selecionados fármacos de alta e baixa permeabilidade, classificados segundo o Sistema de Classificação Biofarmacêutica. Além dos fármacos utilizados para a padronização, alguns cardenolídeos e o composto galato de pentila foram selecionados para testar os modelos padronizados. Para a quantificação das amostras nos compartimentos aceptores e doadores das placas usadas nos experimentos, foram desenvolvidos e validados métodos analíticos por espectrofotometria no UV, segundo critérios preconizados pela ANVISA e ICH. Os resultados obtidos na validação analítica demonstraram que tais métodos foram suficientemente específicos, lineares, precisos e exatos para quantificar as amostras. A partir dos resultados obtidos nos modelos PAMPA TGI, variante Double-Sink e PAMPA Pele, foram calculados os coeficientes de permeabilidade efetiva (Log Pe) para os fármacos/compostos testados, que permearam através das membranas lipídicas usadas e, desta forma, foi possível correlacioná-los com dados da literatura, quando existentes. O galato de pentila apresentou alta permeabilidade nos dois modelos avaliados; já os cardenolídeos apresentaram baixa permeabilidade nos dois modelos, exceto a digitoxigenina, que permeou através da membrana usada no ensaio PAMPA TGI, variante Double-Sink. A integridade das membranas lipídicas usadas nos dois modelos foi avaliada com corantes marcadores de baixa permeabilidade, Azul de Cresil Brilhante (ACB) e Lucifer Yellow (LY), e foi possível demonstrar a integridade e a uniformidade destas membranas, pela baixa passagem do ACB e pela rejeição do LY.
PAMPA assay has demonstrated its versatility since 1998, and it has been used to assess the passive transcellular permeability of drug/compounds, and has gained importance because of its low cost, fast making profile, and also for its particularly help on the elucidation of transport mechanisms together with the assays that make use of caco-2 cells. In order to standardize this assay in the Laboratorio de Virologia Aplicada UFSC, two models: variant Double-Sink PAMPA-GIT and Skin PAMPA were selected by its mimetizing effect on drugs absorption through the gastrointestinal tract and skin, respectively. These two routes were chosen because of easy patient adherence to topical and oral treatment. Initially, to demonstrate the studying models functionality, drugs with high and low permeability were selected, as classified by the Biopharmaceutics Classification System. In addition to the drugs used for standardization, some cardenolide compounds and pentyl gallate were selected to test the standard models. To quantify the samples in compartment acceptors and donors of the plates used in the experiments were developed and analytical methods were validated by UV spectrophotometry, according to the criteria recommended by ICH and ANVISA. The results obtained in the analytical validation showed that these methods were sufficiently specific, linear, precise and accurate to quantify the samples. From the results obtained in PAMPA GIT model, variant Double-Sink PAMPA and skin, the effective permeability coefficients were calculated (log pe) for the drugs / compounds tested that permeated through the lipid membranes used and thus could correlate them with the literature data. The pentyl gallate showed high permeability in the two models evaluated, the cardenolide already had low permeability in the two models, except the digitoxigenin, that permeated through the membrane used in the PAMPA assay TGI, variant Double-Sink. The integrity of the lipid membranes used in both models was assessed with colored markers of low permeability, brilliant cresyl blue (ACB) and Lucifer Yellow (LY), and it was possible to demonstrate the integrity and uniformity of these membranes, the low pass and the ACB rejection of LY.
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Harrison, Olivia Jane. "Integrated platform to assay melanoblast development in vitro." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31164.

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Melanoblasts are the embryonic precursors of melanocytes, the pigment producing cells of the skin and hair. Melanoblasts are of key interest to developmental biologists for numerous reasons, including their ability to migrate throughout the body from a single origin in the neural crest (NC). Current methods for the study of the melanocyte lineage are limited by the heavy reliance on animal models. To challenge this, a platform of in vitro tools were designed to replace and complement current studies. A major obstacle is the transition from 2D cultures, which provide only limited behavioural information, to 3D models which are able to recapitulate the environmental conditions. 3D cultures are regularly created using tissue samples and synthetic matrices for attachment, but building a model from cell lines only has not been achieved. A co-culture model using immortalised keratinocyte (COCA) and melanoblast cell lines proved unsuitable for observing developmental processes, due to lack of movement at high cell densities, but may be practical in pigmentation research. Other methods were explored to examine melanoblast behaviour, including the use of cell derived matrices (CDMs) integrated with melanoblast cell lines, and aggregates formed by hanging drop (HD) culture. CDMs were successfully generated from the COCA line, as well as NIH3T3 fibroblasts which has been shown previously. These structures are denuded of cells to leave the deposited extracellular matrix (ECM) components intact, representative of the dermal (fibroblast) and epidermal (keratinocyte) layers of the skin. HDs were prepared from cultured melanoblast cell lines, and form tight aggregates which disseminate when plated, in a manner similar to the dissemination of cells from the NC in explant cultures. The receptor tyrosine kinase KIT and its ligand (KITL), are vital for melanoblast development. Previous study of this signalling complex has often focussed on the haematopoietic lineage and spermatogenesis, where they perform essential roles. KITL is expressed in a membrane localised form found on the surface of keratinocytes thought to promote melanoblast/melanocyte survival, and a soluble isoform found sequestered in the ECM which promotes cell migration. Cell lines expressing fluorescently tagged KIT and KITL were created to visualise their interactions using live-cell confocal imaging. Firstly, cell lines were generated to perform co-culture experiments with KIT and KITL, and we showed that these constructs are able to interact by uptake of KITL into KIT cells. Secondly, tandem fluorescent protein timers of KIT and KITL were generated which were used to observe protein kinetics. We showed that these protein timers can be manipulated using cycloheximide to block protein production, or by increasing ligand availability. These protein timers reveal that soluble KITL (sKITL) has a faster turnover than membrane bound KITL (mKITL), and that in all three proteins, there is distinct change in spatial localisation as the proteins age. Using a novel melanoblast reporter mouse, Pmel-CMN, primary mouse melanoblasts between E12.5 and E14.5 were isolated for RNA sequencing. This time period is the earliest reported for melanoblast isolation for use in gene expression analysis. We show that within this time course, there are significant changes in the RNA expression profiles, including decreasing expression of other NC cell markers, and huge increasing expression of pigmentation genes. To assess the biological relevance of using in vitro assays, cells of the immortalised melanoblast cell line, melb-a, were cultured under different conditions and examined via RNA sequencing. Results reveal differences in several areas between primary cells and those in culture, including loss of melanocyte specificity. The different tools described in this thesis provide a platform on which to study various aspects of cell behaviour, including migration, morphology and cell adhesion at both the individual cell and population levels.
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Wu, Wing-kei Ricky. "Development of an in vitro assay for MMP cleavage /." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31494183.

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Wu, Wing-kei Ricky, and 胡永基. "Development of an in vitro assay for MMP cleavage." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B4501050X.

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Reader, S. J. "Evaluation of in vitro assay for metabolism-mediated toxicology." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384371.

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Sun, Yuxi. "Development of in vitro Chylomicron Assay Using Caco-2 Cells." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etd/1781.

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Dietary fats are mainly transported by the intestine in lipoproteins: chylomicrons (CMs) and very low density lipoproteins (VLDLs). Unfortunately, studies of the intestinal absorption of dietary fat have been hampered by the lack of an adequate in vitro model system. As an in vitro model Caco-2 cells are able to secrete lipoproteins. We investigated the possible factors that may affect the secretion of CMs through the ultracentrifugation technique. The dose-dependent effects of oleic acid, mono-olein, egg lecithin, collagen matrix, and the effect of cell differentiation on CM secretion were then tested. We found that oleic acid, lecithin, and cell differentiation are critical for CM secretion by Caco-2 cells. To further confirm that our optimal condition is, in fact, favorable for efficient CM production, we compared it with control groups. We observed that our condition led to more efficient CM secretion as determined by the TGs, ApoB, and TEM analysis.
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Schmid, Oliver. "Untersuchungen zur Genotoxizität von Formaldehyd in vitro und in vivo." [S.l. : s.n.], 2009. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-66943.

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Reese, George Edward. "Terahertz Pulsed Imaging of lower gastrointestinal mucosa : an in vitro study." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/26989.

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Medical imaging using Terahertz frequency radiation is in its infancy. Optical adjuncts to enhance the diagnostic precision of white light endoscopy are not new and almost all wavelengths of the electromagnetic spectrum have, at some point, been investigated to this end. The ultimate aim of an endoscopic technique is to identify 100% of mucosal lesions and to classify them with 100% specificity. Methods: This thesis examined the sensitivity and specificity of current technology to accurately identify colonic pathology using a diagnostic precision analysis of published data. The effect of biomaterials such as blood, mucus and faeces on Terahertz radiation was assessed using human tissue samples from health volunteers. The ability to discriminate pathological from normal colonic mucosa was assessed using terahertz radiation to interrogate excised samples of human colon. The physical nature of variation between pathological and normal colonic mucosa was assessed using histological markers in an attempt to identify the cause of terahertz radiation contrast. Results: Current technology has a sensitivity of 95% and a specificity of 78% in a non- inflamed colon. Terahertz pulsed imaging is a sensitive and specific technique for in vitro classification of colonic mucosal pathology. TPI may be a useful adjunct in the presence of inflamed mucosal tissue. Although there were too few data from the present study to quantify any potential benefit. The effects of blood, stool and mucus on TPI are similar but less pronounced than water. Immunohistochemical analysis has demonstrated an association between vascular and lymphatic density with neoplasia. This may be a mechanism for TPI discrimination of colonic pathology. TPI could in the future contribute to a minimally invasive method of in vivo diagnosis of colonic dysplasia or malignancy. Larger scale and in vivo trials of the technology are necessary to further investigate the potential clinical benefit.
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Davies, Catherine Sarah. "In vitro assay of hydroxynaphthoquinones against the liver stages of 'Plasmodium'." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47401.

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Aziza, M. A. E. "In vitro studies on drug diffusion through skin membranes and gastrointestinal tract." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372139.

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Books on the topic "In vitro gastrointestinal assay"

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Aziza, Mohsen A. E. In vitro studies on drug diffusion through skin membranes and gastrointestinal tract. Salford: Universityof Salford, 1986.

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Test No. 479: Genetic Toxicology: In vitro Sister Chromatid Exchange Assay in Mammalian Cells. OECD, 1986. http://dx.doi.org/10.1787/9789264071384-en.

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Harley, Ross. The detection of in vitro DNA damage in primary rat hepatocytes using the alkaline comet assay. 1995.

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Yadav, Kalpana, ed. Studies on Fusarium oxysporum f.sp. radicis cucumerinum Causing Root and Stem rot of Cucumber and in vitro Assay for management. AkiNik Publications, 2022. http://dx.doi.org/10.22271/ed.book.1864.

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Mackie, Alan, Paul Cotter, Kitty Verhoeckx, Iván López-Expósito, Charlotte Kleiveland, Tor Lea, Teresa Requena, Dominika Swiatecka, and Harry Wichers. The Impact of Food Bioactives on Health: In vitro and ex vivo models. Springer, 2015.

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Mackie, Alan, Paul Cotter, Kitty Verhoeckx, Iván López-Expósito, Charlotte Kleiveland, Tor Lea, Teresa Requena, Dominika Swiatecka, and Harry Wichers. The Impact of Food Bioactives on Health: In vitro and ex vivo models. Springer, 2016.

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Schwarz-Faulkner, Susanne *. The development and application of an "in vitro" assay to quantitate the adherence of "Bacteroides gingivalis" to "Actinomyces viscosus" and saliva-coated hydroxyapatite. 1988.

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Wójcik-Gładysz, Anna. Ghrelin – hormone with many faces. Central regulation and therapy. The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 2020. http://dx.doi.org/10.22358/mono_awg_2020.

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Discovered in 1999, ghrelin, is one of the peptides co-creating the hypothalamicgastrointestinal axis, otherwise known as the brain-gut axis. Ghrelin participates in many physiological processes and spectrum of its activity is still being discovered. This 28 amino acid peptide ‒ a product of the ghrl gene, was found in all vertebrates and is synthesized and secreted mainly from enteroendocrine X/A cells located in the gastric mucosa of the stomach. Expression of the ghrelin receptor has been found in many nuclei of the hypothalamus involved in appetite regulation. Therefore it’s presumed that ghrelin is one of the crucial hormones deciphering the energy status required for the maintenance of organism homeostasis. Ghrelin acts as a signal of starvation or energy insufficiency and its level in plasma is reduced after the meal. Neuropeptide Y (NPY) and agouti-related peptide (AgRP; NPY/AgRP) neurons located in the arcuate nucleus (ARC) area are the main target of ghrelin in the hypothalamus. This subpopulation of neurons is indispensable for inducing orexigenic action of ghrelin. Moreover ghrelin acting as a neurohormone, mainly in the hypothalamus area, plays an important role in the regulation of growth and reproduction processes. Indeed, ghrelin action on reproductive processes has been observed in the systemic effects exerted at both hypothalamus-pituitary and gonadal levels. Similarly the GH-releasing ghrelin action was observed both on the hypothalamus level and directly on the somatotrophic cells in the pituitary and this dose-related GH releasing activity was found in in vitro as well as in in vivo experiments. In recent years, numerous studies revealed that ghrelin potentially takes part in the treatment of diseases associated with serious disturbances in the organism energy balance and/or functioning of the gastrointestinal tract. It was underlined that ghrelin may be a hormone with a broad spectrum of therapeutic effect on obesity and anorexia nervosa, as well as may also have protective effect on neurodegenerative diseases, inflammatory disorders or functional changes in the body caused by cancers. In overall, ghrelin treatment has been tested in over 100 preclinical studies with healthy volunteers as well as patients with various types of cancer, eating disorders such as anorexia nervosa and bulimia nervosa. It was observed that ghrelin has an excellent clinical safety profile and emerging side effects occurred only in 3–10% of patients and did not constitute a sufficient premise to discontinue the therapy. In general, it can be concluded that ghrelin may be sufficiently used as a prescription drug.
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Book chapters on the topic "In vitro gastrointestinal assay"

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Thangaraj, Parimelazhagan. "In Vitro Anthelmintic Assay." In Progress in Drug Research, 79–80. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26811-8_12.

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Braegger, C. P., and T. T. Macdonald. "In vitro enteropathy." In Immunology of Gastrointestinal Disease, 137–50. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2978-7_8.

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Davies, Wendy J., and Stuart J. Freeman. "Frog Embryo Teratogenesis Assay." In In Vitro Toxicity Testing Protocols, 311–16. Totowa, NJ: Humana Press, 1995. http://dx.doi.org/10.1385/0-89603-282-5:311.

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Davies, Wendy J., and Stuart J. Freeman. "The Drosophila melanogaster Assay." In In Vitro Toxicity Testing Protocols, 317–20. Totowa, NJ: Humana Press, 1995. http://dx.doi.org/10.1385/0-89603-282-5:317.

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Davies, Wendy J., and Stuart J. Freeman. "The Hydra attentuata Assay." In In Vitro Toxicity Testing Protocols, 321–26. Totowa, NJ: Humana Press, 1995. http://dx.doi.org/10.1385/0-89603-282-5:321.

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Wang, Hui, Anna M. Paczulla, Martina Konantz, and Claudia Lengerke. "In Vitro Tumorigenic Assay: The Tumor Spheres Assay." In Methods in Molecular Biology, 77–87. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-7401-6_7.

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Stoehr, Julia, and Gunter Meister. "In Vitro RISC Cleavage Assay." In Methods in Molecular Biology, 77–90. Totowa, NJ: Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-046-1_6.

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Lyck, Ruth, and Britta Engelhardt. "In Vitro Transendothelial Migration Assay." In Leukocyte Trafficking, 424–36. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/352760779x.ch19.

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Hamczyk, Magda R., Ricardo Villa-Bellosta, and Vicente Andrés. "In Vitro Macrophage Phagocytosis Assay." In Methods in Molecular Biology, 235–46. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2929-0_16.

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Doherty, Ann T. "The In Vitro Micronucleus Assay." In Methods in Molecular Biology, 121–41. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-61779-421-6_7.

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Conference papers on the topic "In vitro gastrointestinal assay"

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Sakavitsi, ME, A. Breynaert, A. Angelis, L. Pieters, N. Hermans, S. Mitakou, and M. Halabalaki. "Simulating human gastrointestinal and colonic biotranformation pathways through an in vitro assay reveals insight on hydroxytyrosol and oleuropein metabolism." In 67th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA) in cooperation with the French Society of Pharmacognosy AFERP. © Georg Thieme Verlag KG, 2019. http://dx.doi.org/10.1055/s-0039-3399660.

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Kos, M., K. Geibler, K. Ratheiser, I. Pabinger, Ch Korninger, and K. Lechner. "ACQUIRED FACTOR X DEFICIENCY IN MULTIPLE MYELOMA:A COMPLETE RESPONSE TO CHEMOTHERAPY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643292.

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A 64 year old women without any previous history of bleeding diathesis presented with bone pain and gastrointestinal bleeding. An isolated severe factor X deficiency (factor X activity 0.5%, factor X antigen less than 12.5%) was found. No inhibitor that inactivated factor X in vitro or interfered with factor X assay could be demonstrated. Substitution therapy with a prothrombin complex preparation containing factor X (PPSB Biotest) was given. Factor X recovery in the first 2 days was lower than expected (below 20%) and half life of factor X was shortened (150 minutes). Subsequently, a diagnosis of multiple myeloma (light chain myeloma, type kappa) was made. Amyloidosis was excluded by electronmicroscopic examination of rectum biopsies. Chemotherapy according to the M2 protocol (Case et al) was initiated. Factor X recovery improved dramatically within 2 weeks and there was a continuous increase of factor X activity and antigen during chemotherapy. After 6 courses a complete haematological remission (less than 5% plasma cells in the bone marrow, disappearance of light chains) was obtained and factor X activity and antigen returned to normal.Isolated factor X deficiency is a wellknown complication of amyloidosis. To our knowledge, this is the first case of factor X deficiency in multiple myeloma without amyloidosis. The complete normalization of factor X after successful chemotherapy indicates that plasma cell proliferation may have been the cause of the factor X deficiency. Binding of factor X to plasma cells containing light chains could be a possible explanation, and we are currently examining this hypothesis.
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Tuenter, E., L. Peeters, and L. Pieters. "In vitro gastrointestinal biotransformation of a Devilʼs claw (Harpagophytum procumbens) extract." In GA – 70th Annual Meeting 2022. Georg Thieme Verlag KG, 2022. http://dx.doi.org/10.1055/s-0042-1759159.

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Ivic-Haymes, Snezana D., Mark Boetel, Larry G. Campbell, Robert Dregsetb, and Ann C. Smigocki. "An in vitro sugar beet root maggot (Tetanops myopaeformis) feeding assay." In 33rd Biennial Meeting of American Society of Sugarbeet Technologist. ASSBT, 2005. http://dx.doi.org/10.5274/assbt.2005.59.

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Ocampo, Romina, Gabriela Montiel Shneider, Andrea Costantino, Sandra Mandolesi, and Liliana Koll. "IN VITRO QUALITATIVE ASSAY OF BENZYLTIN DERIVATES AS BACTERIAL GROWTH INHIBITORS." In The 17th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2013. http://dx.doi.org/10.3390/ecsoc-17-b014.

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Yu, Yingxin, Shuyuan Han, Junling Li, Dongping Zhang, Minghong Wu, Guoying Sheng, and Jiamo Fu. "Digestion Mechanism of Polychlorinated Biphenyls in Gastrointestinal Tract Using In Vitro Test." In 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5162641.

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Martineau-Côté, Delphine, Lamia L'Hocine, Janitha Wanasundara, Allaoua Achouri, and Salwa Karboune. "Health Beneficial Bioactivities of Faba Bean Flour after In vitro Gastrointestinal Digestion." In Virtual 2021 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2021. http://dx.doi.org/10.21748/am21.597.

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Srećković, N., D. Mišić, U. Gašić, and V. Mihailović. "Bioaccessibility of Salvia pratensis L. phenolic compounds during in vitro gastrointestinal digestion." In GA – 70th Annual Meeting 2022. Georg Thieme Verlag KG, 2022. http://dx.doi.org/10.1055/s-0042-1759174.

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Hald, Eric S., Zaw Win, Marianne R. Scheitel, and Patrick W. Alford. "High-Throughput Microtissue Contractility Assay for In Vitro Analysis of Vascular Mechanics." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14604.

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Vascular smooth muscle (VSM) plays a key role in regulation of vascular mechanics through modulation of contractile tone. Studies suggest that mechanical or biochemical perturbation can lead to dysfunctional VSM behavior [1, 2]. This aberrant contractility may play a role in vascular dysfunction ranging from cerebral vasospasm to aneurysm genesis.
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Roberts, Steven, and Nitin Agrawal. "An in vitro single cell assay for transendothelial migration of cancer cells." In 2015 41st Annual Northeast Biomedical Engineering Conference (NEBEC). IEEE, 2015. http://dx.doi.org/10.1109/nebec.2015.7117072.

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Reports on the topic "In vitro gastrointestinal assay"

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Moore, Michael J. A Functional High-Throughput Assay of Myelination in Vitro. Fort Belvoir, VA: Defense Technical Information Center, July 2014. http://dx.doi.org/10.21236/ada608901.

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Moore, Michael J. A Functional High-Throughput Assay of Myelination in Vitro. Fort Belvoir, VA: Defense Technical Information Center, July 2013. http://dx.doi.org/10.21236/ada583762.

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Langland, Gregory T. Establishment of an 'In Vitro Cell-Based System' to Assay Radiation Sensitivity in Breast Cancer. Fort Belvoir, VA: Defense Technical Information Center, May 2007. http://dx.doi.org/10.21236/ada472420.

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Gross, Clark L., Juanita J. Guzman, Charlene M. Corun, Marian R. Nelson, and William J. Smith. Measurement of Protease Release by a Fluorogenic Casein Assay in Human Cells Exposed In Vitro to Sulfur Mustard. Fort Belvoir, VA: Defense Technical Information Center, October 2000. http://dx.doi.org/10.21236/ada390636.

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Brown, George B. Development and Testing of an In Vitro Assay for Screening of Potential Therapeutic Agents Active against Na Channel Neurotoxins. Fort Belvoir, VA: Defense Technical Information Center, April 1991. http://dx.doi.org/10.21236/ada237159.

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Ellis, James L., and Margaret G. Filbert. Development of an In Vitro Model Assay System for the Evaluation of the Effects of Toxic Chemicals on Human Airways. Fort Belvoir, VA: Defense Technical Information Center, March 1994. http://dx.doi.org/10.21236/ada285074.

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Semaan, Dima, and Linda Scobie. Feasibility study for in vitro analysis of infectious foodborne HEV. Food Standards Agency, September 2022. http://dx.doi.org/10.46756/sci.fsa.wfa626.

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Hepatitis E virus (HEV) is a member of the Hepeviridae family capable of infecting humans producing a range of symptoms from mild disease to kidney failure. Epidemiological evidence suggests that hepatitis E genotype III and IV cases may be associated with the consumption of undercooked pork meat, offal and processed products such as sausages [1]. A study carried out by the Animal Health and Veterinary Laboratories Agency (AHVLA), found hepatitis E virus contamination in the UK pork production chain and that 10% of a small sample of retail pork sausages were contaminated with the virus [2]. Furthermore, studies have confirmed the presence of HEV in the food chain and the foodborne transmission of Hepatitis E virus to humans [reviewed in 5]. Likewise, Scottish shellfish at retail [6] have also been found positive for HEV viral nucleic acid and some preliminary studies indicate that the virus is also detectable in soft fruits (L Scobie; unpublished data). There are current misunderstandings in what this data represents, and these studies have raised further questions concerning the infectivity of the virus, the processing of these foods by industry and the cooking and/or preparation by caterers and consumers. There are significant gaps in the knowledge around viral infectivity, in particular the nature of the preparation of food matrices to isolate the virus, and also with respect to a consistent and suitable assay for confirming infectivity [1,3]. Currently, there is no suitable test for infectivity, and, in addition, we have no knowledge if specific food items would be detrimental to cells when assessing the presence of infectious virus in vitro. The FSA finalised a comprehensive critical review on the approaches to assess the infectivity of the HEV virus which is published [3] recommending that a cell culture based method should be developed for use with food. In order to proceed with the development of an infectivity culture method, there is a requirement to assess if food matrices are detrimental to cell culture cell survival. Other issues that may have affected the ability to develop a consistent method are the length of time the virally contaminated sample is exposed to the cells and the concentration of the virus present. In most cases, the sample is only exposed to the cells for around 1 hour and it has been shown that if the concentration is less that 1x103 copies then infection is not established [3,5,10,11].
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Hackett, Wesley, Michael Raviv, Anath Das, Oded Reuveni, and Arie Gutman. Detecting Activity of Juvenile Phase-Specific Translocatable Substances that Influence Rooting Potential Using In Vitro Rooting Assays and Expression of a Specific Gene. United States Department of Agriculture, April 1998. http://dx.doi.org/10.32747/1998.7613038.bard.

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The objectives of the project for which substantial effort was put forth were to: 1) Verify the relationship between expression of a cDNA clone (HW103) and the rooting potential of reciprocally grafted cuttings of juvenile and mature lamina and petioles of Hedera helix L. 2) Detect rooting promoter fractions in exudates from the juvenile leaves of H. Helix by assaying for rooting with leaf petioles of juvenile and mature plants. 3) Isolate, purify and identify compounds which show activity in assays for rooting potential. Some objectives or aspects of the objectives of the original proposal were not pursued for the reasons put forth in the body of the report. The most significant findings of the project are: 1) The MS medium is a better medium than Romberg medium for performing the leaf petiole rooting assay. 2) HW103 gene expression is cell-type specific with higher levels of expression in mature than juvenile phase H. Helix petioles as evidenced by in situ hybridization which suggests a negative relationship between HW103 expression in specific cells involved in root initiation and the lack of rooting potential in mature petioles 3) HW103 gene expression may be lower in mature petioles which had been grafter to a juvenile H. Helix lamina than mature petioles that had been grafted to a mature lamina and this putative lower expression is related to formation of a higher number of roots. 4) HW103 gene expression is not related to auxin induced ethylene production. 5) Two distinct compounds that possess root initiation promoting activity can be detected mainly in diffusate of juvenile H. Helix leaves using mung bean hypocotyls and H. Helix leaf petioles in vitro. 6) H. Helix diffusate active fractions do not insistenlty promote rooting in avocado mini-cuttings. 7) Chemical identification of the active rooting compounds was not accomplished because of the death of Prof. Becker, one of the collaborators, and the resultant loss of his data. These results indicate that these may be a molecular basis for reduced rooting potential in mature H. Helix petioles and that there are diffusible (translocatable) compounds in juvenile H. Helix leaves which promote rooting in juvenile and mature H. Helix petioles and mung bean hypocotyls.
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Boisclair, Yves R., Alan W. Bell, and Avi Shamay. Regulation and Action of Leptin in Pregnant and Lactating Dairy Cows. United States Department of Agriculture, July 2000. http://dx.doi.org/10.32747/2000.7586465.bard.

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The original project had four specific objectives: (1) To complete the development of a radioimmunoassay for bovine leptin; (2) To characterize the leptin system in lactating dairy cows during the transition from pregnancy to lactation; (3) To identify endocrine factors regulating the production of leptin by bovine adipose tissue; (4) To study the actions of leptin on bovine adipose and mammary tissues in vitro. However, BARD funded only the development of the bovine leptin RIA (Objective 1) for a single year. This report describes our work in completing this objective. Leptin, a protein hormone secreted predominantly by white adipose tissue, plays a critical role in the regulation of energy metabolism. In rodents and humans, leptin informs the central nervous system of the size of the energy reserves, coordinates adaptations to periods of nutrient insufficiency, and regulates the metabolism of key tissues involved in the storage and dissipation of energy. However, almost nothing is known on the biology of leptin in cattle, in part because of the absence of a valid assay to measure bovine leptin. To remediate this situation, we have developed a radioimmunoassay capable of measuring bovine leptin with a high degree of sensitivity, accuracy and precision. First, we produced recombinant bovine leptin and used it to immunize rabbits, and to prepare bovine leptin trace and standards. A single antiserum with sufficient affinity and titer was identified. Using this antiserum, binding of 125I bovine leptin was displaced in a dose dependent manner by the addition of bovine or ovine leptin. Serial dilution of bovine and ovine plasma gave displacement curves that were parallel to that of bovine or ovine leptin. Recoveries of external addition of bovine leptin in ewe and cow plasma ranged between 94 and 104%. Plasma leptin concentration measured by this assay was increased by the plane of nutrition in growing calves and lambs. Finally, plasma leptin concentration was linearly related to the fat content of the empty carcass in growing cattle. We conclude that circulating leptin in sheep and cattle is increased by fatness and plane of nutrition, consistent with results in humans and rodents. This assay provides an important tool to investigate mechanisms that regulate plasma leptin in cattle and sheep.
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Reisch, Bruce, Avichai Perl, Julie Kikkert, Ruth Ben-Arie, and Rachel Gollop. Use of Anti-Fungal Gene Synergisms for Improved Foliar and Fruit Disease Tolerance in Transgenic Grapes. United States Department of Agriculture, August 2002. http://dx.doi.org/10.32747/2002.7575292.bard.

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Original objectives . 1. Test anti-fungal gene products for activity against Uncinula necator, Aspergillus niger, Rhizopus stolonifer and Botrytis cinerea. 2. For Agrobacterium transformation, design appropriate vectors with gene combinations. 3. Use biolistic bombardment and Agrobacterium for transformation of important cultivars. 4. Characterize gene expression in transformants, as well as level of powdery mildew and Botrytis resistance in foliage of transformed plants. Background The production of new grape cultivars by conventional breeding is a complex and time-consuming process. Transferring individual traits via single genes into elite cultivars was proposed as a viable strategy, especially for vegetatively propagated crops such as grapevines. The availability of effective genetic transformation procedures, the existence of genes able to reduce pathogen stress, and improved in vitro culture methods for grapes, were combined to serve the objective of this proposal. Effective deployment of resistance genes would reduce production costs and increase crop quality, and several such genes and combinations were used in this project. Progress The efficacy of two-way combinations of Trichoderma endochitinase (CHIT42), synthetic peptide ESF12 and resveratrol upon the control of growth of Botrytis cinerea and Penicillium digitatum were evaluated in vitro. All pairwise interactions were additive but not synergistic. Per objective 2, suitable vectors with important gene combinations for Agrobacterium transformation were designed. In addition, multiple gene co-transformation by particle bombardment was also tested successfully. In New York, transformation work focused on cultivars Chardonnay and Merlot, while the technology in Israel was extended to 41B, R. 110, Prime, Italia, Gamay, Chardonnay and Velika. Transgenic plant production is summarized in the appendix. Among plants developed in Israel, endochitinase expression was assayed via the MuchT assay using material just 1-5 days after co-cultivation. Plants of cv. Sugraone carrying the gene coding for ESF12, a short anti-fungal lytic peptide under the control of the double 358 promoter, were produced. Leaf extracts of two plants showed inhibition zones that developed within 48 h indicating the inhibitory effect of the leaf extracts on the six species of bacteria. X fastidiosa, the causal organism of Pierce's disease, was very sensitive to leaf extracts from ESF12 transformed plants. Further work is needed to verify the agricultural utility of ESF12 transformants. In New York, some transformants were resistant to powdery mildew and Botrytis fruit rot. Major conclusions, solutions, achievements and implications The following scientific achievements resulted from this cooperative BARD project: 1. Development and improvement of embryogenesis and tissue culture manipulation in grape, while extending these procedures to several agriculturally important cultivars both in Israel and USA. 2. Development and improvement of novel transformation procedures while developing transformation techniques for grape and other recalcitrant species. 3. Production of transgenic grapevines, characterization of transformed vines while studying the expression patterns of a marker gene under the control of different promoter as the 35S CaMV in different part of the plants including flowers and fruits. 4. Expression of anti-fungal genes in grape: establishment of transgenic plants and evaluation of gene expression. Development of techniques to insert multiple genes. 5. Isolation of novel grape specific promoter to control the expression of future antimicrobial genes. It is of great importance to report that significant progress was made in not only the development of transgenic grapevines, but also in the evaluation of their potential for increased resistance to disease as compared with the non engineered cultivar. In several cases, increased disease resistance was observed. More research and development is still needed before a product can be commercialized, yet our project lays a framework for further investigations.
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