scholarly journals Recent advances in transport of water-soluble vitamins in organs of the digestive system: a focus on the colon and the pancreas

2013 ◽  
Vol 305 (9) ◽  
pp. G601-G610 ◽  
Author(s):  
Hamid M. Said
Keyword(s):  
Large Intestine ◽  
Digestive System ◽  
Cell Function ◽  
Strong Support ◽  
Alcohol Exposure ◽  
Cell Types ◽  
Water Soluble ◽  
Recent Advances ◽  
Efficient Uptake ◽  
Metabolic Activities

This review focuses on recent advances in our understanding of the mechanisms and regulation of water-soluble vitamin (WSV) transport in the large intestine and pancreas, two important organs of the digestive system that have only recently received their fair share of attention. WSV, a group of structurally unrelated compounds, are essential for normal cell function and development and, thus, for overall health and survival of the organism. Humans cannot synthesize WSV endogenously; rather, WSV are obtained from exogenous sources via intestinal absorption. The intestine is exposed to two sources of WSV: a dietary source and a bacterial source (i.e., WSV generated by the large intestinal microbiota). Contribution of the latter source to human nutrition/health has been a subject of debate and doubt, mostly based on the absence of specialized systems for efficient uptake of WSV in the large intestine. However, recent studies utilizing a variety of human and animal colon preparations clearly demonstrate that such systems do exist in the large intestine. This has provided strong support for the idea that the microbiota-generated WSV are of nutritional value to the host, and especially to the nutritional needs of the local colonocytes and their health. In the pancreas, WSV are essential for normal metabolic activities of all its cell types and for its exocrine and endocrine functions. Significant progress has also been made in understanding the mechanisms involved in the uptake of WSV and the effect of chronic alcohol exposure on the uptake processes.

Freeze-substitution of rye grass and ragweed pollen grains

1990 ◽  
Vol 48 (3) ◽  
pp. 686-687
Author(s):  
Liza B. Martinez ◽  
Susan M. Wick
Keyword(s):  
Cell Function ◽  
Pollen Grains ◽  
Freeze Substitution ◽  
Cell Types ◽  
Rapid Freezing ◽  
Rye Grass ◽  
Acrylic Resins ◽  
Allergenic Proteins ◽  
Cold Embedding ◽  
Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

scholarly journals Multiple Roles for Cholinergic Signaling from the Perspective of Stem Cell Function

2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Embryonic Stem ◽  
Cholinergic Neurons ◽  
Cell Types ◽  
Proliferative Potential ◽  
True Nature ◽  
Cholinergic Signaling

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.

scholarly journals Alcohol Exposure Impairs Myeloid Dendritic Cell Function in Rhesus Macaques

2009 ◽  
Vol 33 (9) ◽  
pp. 1524-1531 ◽  
Author(s):  
Robert W. Siggins ◽  
Gregory J. Bagby ◽  
Patricia Molina ◽  
Jason Dufour ◽  
Steve Nelson ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Cell Function ◽  
Rhesus Macaques ◽  
Alcohol Exposure ◽  
Myeloid Dendritic Cell ◽  
Dendritic Cell Function

Micropatterned array to assess the interaction of single platelets with platelet factor 4-heparin-IgG complexes

2014 ◽  
Vol 111 (05) ◽  
pp. 862-872 ◽  
Author(s):  
Krystin Krauel ◽  
Nikolay Medvedev ◽  
Raghavendra Palankar ◽  
Andreas Greinacher ◽  
Mihaela Delcea
Keyword(s):  
Calcium Imaging ◽  
Cell Function ◽  
Platelet Factor 4 ◽  
Water Soluble ◽  
Cell Level ◽  
Platelet Factor ◽  
Ligand Density ◽  
Heparin Complexes ◽  
Novel Method ◽  
Platelet Aggregates

SummaryWe report a strategy to generate by electron beam lithography high fidelity micropatterned arrays to assess the interaction of single platelets with immobilised ligands. As a proof-of-principle we functionalised the microarrays with platelet factor 4 (PF4)-heparin-IgG complexes. We embedded biotinylated water-soluble quantum dots into polyethylene glycol (PEG)-coated micropatterned arrays and functionalised them via streptavidin to bind biotinylated ligands, here biotinylated-PF4/heparin complexes. The integrity of the PF4/heparin-complexes was shown by binding of anti-PF4/heparin antibodies. Ligand density was quantified by immunofluorescence and immunogold antibody labelling. Real-time calcium imaging was employed for read-out of single platelets activated on micropatterned surfaces functionalised with PF4/heparin-IgG complexes. With the smallest micropatterns (0.5x0.5 µm) we show that single platelets become strongly activated by binding to surface-immobilised PF4/heparin-IgG, while on larger micropatterns (10x10 µm), platelet aggregates formed. These findings that HIT antibodies can cause platelet activation on microarrays illustrate how this novel method opens new avenues to study platelet function at single cell level. Generating functionalized microarray surfaces to which highly complex ligands can be bound and quantified has the potential for platelet and other cell function assays integrated into high-throughput microfluidic microdevices.

scholarly journals Recent Advances in Herbal Medicines for Digestive System Malignancies

2018 ◽  
Vol 9 ◽  
Author(s):  
Jiyao Sheng ◽  
Xiaohan Zou ◽  
Ziqian Cheng ◽  
Yien Xiang ◽  
Wei Yang ◽  
...  
Keyword(s):  
Digestive System ◽  
Herbal Medicines ◽  
Recent Advances

Description of the gastrointestinal tract and associated organs of the kultarr (Antechinomys laniger)

2013 ◽  
Vol 35 (1) ◽  
pp. 39 ◽  
Author(s):  
Hayley J. Stannard ◽  
Julie M. Old
Keyword(s):  
Gastrointestinal Tract ◽  
Digestive Tract ◽  
Large Intestine ◽  
Cell Types ◽  
Post Mortem ◽  
Microscopic Description ◽  
Future Studies ◽  
New Information ◽  
Small And Large Intestine

This paper provides a macro- and microscopic description of the digestive tract of the kultarr (Antechinomys laniger), a small dasyurid marsupial. The digestive tract was simple, with no external differentiation between the small and large intestine, and lacked a caecum. Mean gross length of the kultarr digestive tract was 165.2 ± 32.1 mm. Microscopically, the tissues had cell types similar to those of other mammals. The new information will aid future post-mortem investigations of captive kultarrs and future studies of nutrition.

Abstract 1440: Endothelial And Cardiomyocyte Toxicity Of Endogenously Produced Nucleoside: 4-pyridone-3-carboxamide-1-β-d-riboside

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ewa M Slominska ◽  
Czeslawa Orlewska ◽  
Cesare M Terracciano ◽  
Ada H Yuen ◽  
Urszula Siedlecka ◽  
...  
Keyword(s):  
Renal Failure ◽  
Endothelial Cells ◽  
Chronic Renal Failure ◽  
Cell Line ◽  
Cell Function ◽  
Cell Types ◽  
Human Erythrocytes ◽  
Rat Hearts ◽  
Prolongation Of Action Potential ◽  
Ribonucleoside Triphosphate

Our recent studies identified hitherto unknown, naturally occurring nucleotide: 4-pyridone-3-carboxamide-1-β-D-ribonucleoside triphosphate (4PYTP). This nucleotide was found to accumulate in the erythrocytes of patients with chronic renal failure, a condition that precipitates heart failure and atherosclerosis. We found also increase in plasma concentration of nucleoside precursor of 4PYTP: 4-pyridone-3-carboxamide-1-β-D-ribonucleoside (4PYR) in patients with renal failure. This study was aimed to evaluate metabolism and potential toxic effect of this nucleoside in cardiomyocytes and endothelial cells. We used human erythrocytes isolated from peripheral blood, human endothelial cell line HMEC-1 cell line and cardiomyocytes isolated from rat hearts. Cells were incubated with chemically synthesized 4PYR. Metabolic assessments were performed with HPLC or liquid chromatography/mass spectrometry. We demonstrated formation of 4PYTP in human erythrocytes during incubation with 4PYR. We noted however, preferential accumulation of monophosphate of 4PYR (4PYMP) over 4PYTP. Concentration of 4PYMP increased in the erythrocytes from below 5 μM to 76.9±7.1, 254.7±13.9 and 674.3±34.3 μM after 6h incubation with 0.1, 0.3 and 1 mM 4PYR. 4PYMP progressively accumulated in the cultured endothelial cells during incubation with 4PYR up to 72 h. Cardiomyocytes were also shown to accumulate 4PYMP. In all cell types formation of 4PYR nucleotides was accompanied by decrease in cellular ATP concentration. Furthermore, treatment with 4PYR and formation of its nucleotides in endothelial cells reduced NO synthase pathway while in cardiac myocytes resulted in prolongation of action potential. We conclude that endogenously formed 4PYR is effectively metabolized to nucleotide derivatives in the erythrocytes, cardiomyocytes and endothelium. Depletion of ATP in these cells accompanying 4PYR metabolism and deleterious effects on cell function suggests that accumulation of 4PYR and its enhanced metabolism to nucleotides in endothelium and cardiomyocyted may contribute to cardiovascular pathology observed in chronic renal failure.

scholarly journals Administration of cardiac mesenchymal cells modulates innate immunity in the acute phase of myocardial infarction in mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Kang ◽  
Marjan Nasr ◽  
Yiru Guo ◽  
Shizuka Uchida ◽  
Tyler Weirick ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Innate Immunity ◽  
Mechanism Of Action ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Mesenchymal Cell ◽  
Cell Types

Abstract Although cardiac mesenchymal cell (CMC) therapy mitigates post-infarct cardiac dysfunction, the underlying mechanisms remain unidentified. It is acknowledged that donor cells are neither appreciably retained nor meaningfully contribute to tissue regeneration—suggesting a paracrine-mediated mechanism of action. As the immune system is inextricably linked to wound healing/remodeling in the ischemically injured heart, the reparative actions of CMCs may be attributed to their immunoregulatory properties. The current study evaluated the consequences of CMC administration on post myocardial infarction (MI) immune responses in vivo and paracrine-mediated immune cell function in vitro. CMC administration preferentially elicited the recruitment of cell types associated with innate immunity (e.g., monocytes/macrophages and neutrophils). CMC paracrine signaling assays revealed enhancement in innate immune cell chemoattraction, survival, and phagocytosis, and diminished pro-inflammatory immune cell activation; data that identifies and catalogues fundamental immunomodulatory properties of CMCs, which have broad implications regarding the mechanism of action of CMCs in cardiac repair.

scholarly journals RNA regulons are essential in intestinal homeostasis

2019 ◽  
Vol 316 (1) ◽  
pp. G197-G204 ◽  
Author(s):  
Louis R. Parham ◽  
Patrick A. Williams ◽  
Priya Chatterji ◽  
Kelly A. Whelan ◽  
Kathryn E. Hamilton
Keyword(s):  
Epithelial Cells ◽  
Rna Binding ◽  
Environmental Changes ◽  
Cell Function ◽  
Rna Binding Proteins ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Cell Dynamics ◽  
Functional Roles ◽  
Proliferating Cell

Intestinal epithelial cells are among the most rapidly proliferating cell types in the human body. There are several different subtypes of epithelial cells, each with unique functional roles in responding to the ever-changing environment. The epithelium’s ability for rapid and customized responses to environmental changes requires multitiered levels of gene regulation. An emerging paradigm in gastrointestinal epithelial cells is the regulation of functionally related mRNA families, or regulons, via RNA-binding proteins (RBPs). RBPs represent a rapid and efficient mechanism to regulate gene expression and cell function. In this review, we will provide an overview of intestinal epithelial RBPs and how they contribute specifically to intestinal epithelial stem cell dynamics. In addition, we will highlight key gaps in knowledge in the global understanding of RBPs in gastrointestinal physiology as an opportunity for future studies.

Water-soluble metal nanoclusters: recent advances in molecular-level exploration and biomedical applications

2019 ◽  
Vol 48 (28) ◽  
pp. 10385-10392 ◽  
Author(s):  
Xinyue Dou ◽  
Xiaoyu Chen ◽  
Haiguang Zhu ◽  
Yong Liu ◽  
Dongyun Chen ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Molecular Level ◽  
Water Soluble ◽  
Metal Nanoclusters ◽  
Growth Processes ◽  
Recent Advances ◽  
Ligand Shell

Recent advances of water-soluble metal nanoclusters (MNCs) in designing highly luminescent MNCs, ligand shell engineering, tracking MNC's growth processes, and biomedical applications are highlighted.

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