268 research outputs found

    Microbiota of Tayohounta, a fermented baobab flavour food of Benin

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    The present work provides data on the microbial composition of Tayohounta, a product of natural fermentation of baobab seed kernels. Samples were collected from 3 different small scale producers from Benin at the end of the fermentation process. Microorganisms were enumerated and identified using phenotypic and molecular approaches. Tayohounta was also investigated using culture independent techniques, direct DNA extraction, polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE) and cloning. Isolated microorganisms were tested for their functionality in baobab seed kernels fermentation. Total viable counts were around 9 log cfu/g representing mainly Bacillus spp., whereas lactic acid bacteria (LAB) (8 log cfu/g), yeasts and moulds represent a smaller part of the total flora in all Tayohounta samples. Sequencing of clones of polymerase chain reaction (PCR) products of bacterial DNA directly extracted from Tayohounta revealed large differences between the products made by different producers. In all products, Bacillus licheniformis, B. pumilus, B. subtilis, B. thermoamylovorans and Lactobacillus fermentum were present. Other microorganisms (B. thuringiensis, Brevibacterium borstelensis, Enterococcus casseliflavus, E. durans, Lb. agilis, Pediococcus pentosaceus, Streptococcus equinus and Weissella confusa) were present occasionally. In experimental pure culture fermentations, B. subtilis showed little effect on pH, but degraded protein and caused a typical pungent smell typical of Tayohounta

    A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH

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    A comparative study of vitamin B6 group and related compounds in buffered solutions using electrochemical techniques has been performed at neutral pH. Irreversible bi- or tetra-electronic processes are observed for these substances, and the electron transfer coefficient (αn) calculated. It was concluded that either the first or second electron transfer were the rate determining step of the electrode process. The diffusion coefficient of these substances was calculated and the values given follow an inverse tendency to the molecular size. For aldehydes the values obtained were corrected of the hydration reaction. It is important to remark that catalytic waves were reported for the first time for these compounds. Using a model involving the nitrogen of the basic structure the kinetic constants were calculated for most of them

    Amine functionalization of cholecyst-derived extracellular matrix with generation 1 PAMAM dendrimer

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    This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Biomacromolecules, copyright © American Chemical Society after peer review. To access the final edited and published work, see http://pubs.acs.org/doi/pdf/10.1021/bm701055k.A method to functionalize cholecyst-derived extracellular matrix (CEM) with free amine groups was established in an attempt to improve its potential for tethering of bioactive molecules. CEM was incorporated with Generation-1 polyamidoamine (G1 PAMAM) dendrimer by using N-(3-dimethylaminopropyl)-Nâ€Č-ethylcarbodiimide and N-hydroxysuccinimide cross-linking system. The nature of incorporation of PAMAM dendrimer was evaluated using shrink temperature measurements, Fourier transform infrared (FTIR) assessment, ninhydrin assay, and swellability. The effects of PAMAM incorporation on mechanical and degradation properties of CEM were evaluated using a uniaxial mechanical test and collagenase degradation assay, respectively. Ninhydrin assay and FTIR assessment confirmed the presence of increasing free amine groups with increasing quantity of PAMAM in dendrimer-incorporated CEM (DENCEM) scaffolds. The amount of dendrimer used was found to be critical in controlling scaffold degradation, shrink temperature, and free amine content. Cell culture studies showed that fibroblasts seeded on DENCEM maintained their metabolic activity and ability to proliferate in vitro. In addition, fluorescence cell staining and scanning electron microscopy analysis of cell-seeded DENCEM showed preservation of normal fibroblast morphology and phenotype

    Letter from the Citizens of Ommen to the Governor of Overijssel

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    Sixteen citizens of Ommen sent a communication to the Governor of the Province that they saw no need for him to send a military detachment to Ommen now that the disturbances had ended. Besides, a relatively few people were the troublemakers. The billeting of military people will be a great burden to the citizens of Ommen.https://digitalcommons.hope.edu/vrp_1830s/1048/thumbnail.jp

    Membrane chemical stability and seed longevity

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    Here, we investigate the relationships between the chemical stability of the membrane surface and seed longevity. Dry embryos of long-lived tomato and short-lived onion seeds were labeled with 5-doxyl-stearic acid (5-DS). Temperature-induced loss of the electron spin resonance signal caused by chemical conversion of 5-DS to nonparamagnetic species was used to characterize the membrane surface chemical stability. No difference was found between temperature plots of 5-DS signal intensity in dry onion and tomato below 345 K. Above this temperature, the 5-DS signal remained unchanged in tomato embryos and irreversibly disappeared in onion seeds. The role of the physical state and chemical status of the membrane environment in the chemical stability of membrane surfaces was estimated for model systems containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) dried alone or in the presence of trehalose or glucose. Fourier transform infrared spectroscopy was used to follow temperature-induced structural changes in dry POPC. Spin-label technique was used to relate the chemical stability of 5-DS with the dynamic properties of the bilayer and 5-DS motion behavior. In all the models, the decrease in 5-DS signal intensity was always observed above Tm for the membrane surface. The 5-DS signal was irreversibly lost at high temperature when dry POPC was embedded in a glucose matrix. The loss of 5-DS signal was moderate when POPC was dried alone or in the presence of trehalose. Comparison of model and in vivo data shows that the differences in longevity between onion and tomato seeds are caused by differences in the chemical status of the membrane surface rather than the degree of its immobilization

    T cells expanded from renal cell carcinoma display tumor-specific CD137 expression but lack significant IFN-gamma, TNF-alpha or IL-2 production

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    Metastatic renal cell carcinoma (RCC) has a poor prognosis. Recent advances have shown beneficial responses to immune checkpoint inhibitors, such as anti-PD-1/PD-L1 antibodies. As only a subset of RCC patients respond, alternative strategies should be explored. Patients refractory to anti-PD-1 therapy may benefit from autologous tumor-infiltrating lymphocyte (TIL) therapy. Even though efficient TIL expansion was reported from RCC lesions, it is not well established how many RCC TIL products are tumor-reactive, how well they produce pro-inflammatory cytokines in response to autologous tumors, and whether their response correlates with the presence of specific immune cells in the tumor lesions. We here compared the immune infiltrate composition of RCC lesions with that of autologous kidney tissue of 18 RCC patients. Tcell infiltrates were increased in the tumor lesions, and CD8(+) Tcell infiltrates were primarily of effector memory phenotype. Nine out of 16 (56%) tested TIL products we generated were tumor-reactive, as defined by CD137 upregulation after exposure to autologous tumor digest. Tumor reactivity was found in particular in TIL products originating from tumors with ahigh percentage of infiltrated Tcells compared to autologous kidney, and increased CD25 expression on CD8(+) Tcells. Importantly, although TIL products had the capacity to produce the key effector cytokines IFN-gamma, TNF-alpha or IL-2, they failed to produce significant amounts in response to autologous tumor digests. In conclusion, TIL products from RCC lesions contain tumor-reactive Tcells. Their restricted tumor-specific cytokine production requires further investigation of immunosuppressive factors in RCC and subsequent optimization of RCC-derived TIL culture conditions.Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease

    Adrenergic ÎČ2 receptor activation stimulates anti-inflammatory properties of dendritic cells in vitro

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    Vagal nerve efferent activation has been shown to ameliorate the course of many inflammatory disease states. This neuromodulatory effect has been suggested to rest on acetylcholine receptor (AChR) activation on tissue macrophages or dendritic cells (DCs). In more recent studies, vagal anti-inflammatory activity was shown involve adrenergic, splenic, pathways. Here we provide evidence that the adrenergic, rather than cholinergic, receptor activation on bone marrow derived DCs results in enhanced endocytosis uptake, enhanced IL-10 production but a decreased IL-6, IL-12p70 and IL-23 production. In antigen specific T cell stimulation assays, adrenergic ÎČ2 receptor activation on bone marrow DCs led to an enhanced potential to induce Foxp3 positive suppressive Treg cells. These effects were independent of IL10-R activation, TGFÎČ release, or retinoic acid (RA) secretion. Hence, adrenergic receptor ÎČ2 activation modulates DC function resulting in skewing towards anti-inflammatory T cell phenotypes

    The FAT10- and ubiquitin-dependent degradation machineries exhibit common and distinct requirements for MHC class I antigen presentation

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    Like ubiquitin (Ub), the ubiquitin-like protein FAT10 can serve as a signal for proteasome-dependent protein degradation. Here, we investigated the contribution of FAT10 substrate modification to MHC class I antigen presentation. We show that N-terminal modification of the human cytomegalovirus-derived pp65 antigen to FAT10 facilitates direct presentation and dendritic cell-mediated cross-presentation of the HLA-A2 restricted pp65495–503 epitope. Interestingly, our data indicate that the pp65 presentation initiated by either FAT10 or Ub partially relied on the 19S proteasome subunit Rpn10 (S5a). However, FAT10 distinguished itself from Ub in that it promoted a pp65 response which was not influenced by immunoproteasomes or PA28. Further divergence occurred at the level of Ub-binding proteins with NUB1 supporting the pp65 presentation arising from FAT10, while it exerted no effect on that initiated by Ub. Collectively, our data establish FAT10 modification as a distinct and alternative signal for facilitated MHC class I antigen presentation

    Freeze-Dried Somatic Cells Direct Embryonic Development after Nuclear Transfer

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    The natural capacity of simple organisms to survive in a dehydrated state has long been exploited by man, with lyophylization the method of choice for the long term storage of bacterial and yeast cells. More recently, attempts have been made to apply this procedure to the long term storage of blood cells. However, despite significant progress, practical application in a clinical setting is still some way off. Conversely, to date there are no reports of attempts to lyophilize nucleated somatic cells for possible downstream applications. Here we demonstrate that lyophilised somatic cells stored for 3 years at room temperature are able to direct embryonic development following injection into enucleated oocytes. These remarkable results demonstrate that alternative systems for the long-term storage of cell lines are now possible, and open unprecedented opportunities in the fields of biomedicine and for conservation strategies

    High-Throughput Identification of Potential Minor Histocompatibility Antigens by MHC Tetramer-Based Screening: Feasibility and Limitations

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    T-cell recognition of minor histocompatibility antigens (MiHA) plays an important role in the graft-versus-tumor (GVT) effect of allogeneic stem cell transplantation (allo-SCT). However, the number of MiHA identified to date remains limited, making clinical application of MiHA reactive T-cell infusion difficult. This study represents the first attempt of genome-wide prediction of MiHA, coupled to the isolation of T-cell populations that react with these antigens. In this unbiased high-throughput MiHA screen, both the possibilities and pitfalls of this approach were investigated. First, 973 polymorphic peptides expressed by hematopoietic stem cells were predicted and screened for HLA-A2 binding. Subsequently a set of 333 high affinity HLA-A2 ligands was identified and post transplantation samples from allo-SCT patients were screened for T-cell reactivity by a combination of pMHC-tetramer-based enrichment and multi-color flow cytometry. Using this approach, 71 peptide-reactive T-cell populations were generated. The isolation of a T-cell line specifically recognizing target cells expressing the MAP4K1IMA antigen demonstrates that identification of MiHA through this approach is in principle feasible. However, with the exception of the known MiHA HMHA1, none of the other T-cell populations that were generated demonstrated recognition of endogenously MiHA expressing target cells, even though recognition of peptide-loaded targets was often apparent
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