Exploring the breakdown of dairy protein gels during in vitro gastric digestion using time-lapse synchrotron deep-UV fluorescence microscopy

2018 ◽  
Vol 239 ◽  
pp. 898-910 ◽  
Author(s):  
Juliane Floury ◽  
Tiago Bianchi ◽  
Jonathan Thévenot ◽  
Didier Dupont ◽  
Frédéric Jamme ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Time Lapse ◽  
Gastric Digestion ◽  
Uv Fluorescence ◽  
Protein Gels ◽  
Deep Uv ◽  
Dairy Protein

Gastric digestion of milk protein gels as assessed by time-lapse Synchrotron UV-microscopy

2016 ◽  
pp. 312-312
Author(s):  
Jonathan Thévenot ◽  
Juliane Floury ◽  
Frédéric Jamme ◽  
Maud Panouillé ◽  
Evelyne Lutton ◽  
...  
Keyword(s):  
Milk Protein ◽  
Time Lapse ◽  
Gastric Digestion ◽  
Protein Gels

scholarly journals Direct Visualization of Amlodipine Intervention into Living Cells by Means of Fluorescence Microscopy

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2997
Author(s):  
Christine Quentin ◽  
Rūta Gerasimaitė ◽  
Alexandra Freidzon ◽  
Levon S. Atabekyan ◽  
Gražvydas Lukinavičius ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Aqueous Solutions ◽  
Time Lapse ◽  
Drug Uptake ◽  
Live Cells ◽  
Direct Visualization ◽  
Cellular Environment ◽  
Time Lapse Imaging ◽  
The Impact

Amlodipine, a unique long-lasting calcium channel antagonist and antihypertensive drug, has weak fluorescence in aqueous solutions. In the current paper, we show that direct visualization of amlodipine in live cells is possible due to the enhanced emission in cellular environment. We examined the impact of pH, polarity and viscosity of the environment as well as protein binding on the spectral properties of amlodipine in vitro, and used quantum chemical calculations for assessing the mechanism of fluorescence quenching in aqueous solutions. The confocal fluorescence microscopy shows that the drug readily penetrates the plasma membrane and accumulates in the intracellular vesicles. Visible emission and photostability of amlodipine allow confocal time-lapse imaging and the drug uptake monitoring.

scholarly journals The lighthouse at the end of the chromosome*

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1427 ◽  
Author(s):  
Yahya Benslimane ◽  
Lea Harrington
Keyword(s):  
Fluorescence Microscopy ◽  
Single Molecule ◽  
Spatial Organization ◽  
Three Dimensional ◽  
Time Lapse ◽  
Living Cells ◽  
Telomere Elongation ◽  
Cellular Processes ◽  
Time Lapse Microscopy

Fluorescence microscopy can be used to assess the dynamic localization and intensity of single entities in vitro or in living cells. It has been applied with aplomb to many different cellular processes and has significantly enlightened our understanding of the heterogeneity and complexity of biological systems. Recently, high-resolution fluorescence microscopy has been brought to bear on telomeres, leading to new insights into telomere spatial organization and accessibility, and into the mechanistic nuances of telomere elongation. We provide a snapshot of some of these recent advances with a focus on mammalian systems, and show how three-dimensional, time-lapse microscopy and single-molecule fluorescence shine a new light on the end of the chromosome.

The importance of swelling for in vitro gastric digestion of whey protein gels

2020 ◽  
Vol 330 ◽  
pp. 127182 ◽  
Author(s):  
Ruoxuan Deng ◽  
Monica Mars ◽  
Ruud G.M. Van Der Sman ◽  
Paul A.M. Smeets ◽  
Anja E.M. Janssen
Keyword(s):  
Whey Protein ◽  
Gastric Digestion ◽  
Protein Gels

Breakdown mechanisms of whey protein gels during dynamic in vitro gastric digestion

2021 ◽  
Author(s):  
Yamile A. Mennah-Govela ◽  
Gail M. Bornhorst
Keyword(s):  
Whey Protein ◽  
Protein Hydrolysis ◽  
Gastric Digestion ◽  
Pepsin Activity ◽  
Protein Gels ◽  
Hydrolysis Of ◽  
Particle Geometry

Particle geometry influenced the breakdown mechanisms impacting the pH, pepsin activity, and protein hydrolysis of whey protein gels during dynamic in vitro gastric digestion.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

scholarly journals Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 321
Author(s):  
Camila Mella ◽  
Michelle Quilaqueo ◽  
Rommy N. Zúñiga ◽  
Elizabeth Troncoso
Keyword(s):  
Heat Treatment ◽  
Protein Isolate ◽  
Gastric Digestion ◽  
Human Gastrointestinal Tract ◽  
Gel Structure ◽  
Intestinal Digestion ◽  
Food Digestion ◽  
The Impact ◽  
Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

In vitro dynamic gastric digestion of soya protein/milk protein blended beverages: influence of protein composition and co-processing

2021 ◽  
Vol 12 (6) ◽  
pp. 2605-2616
Author(s):  
Teresa Francis Wegrzyn ◽  
Alejandra Acevedo-Fani ◽  
Simon M. Loveday ◽  
Harjinder Singh
Keyword(s):  
Whey Protein ◽  
Milk Protein ◽  
Protein Composition ◽  
Soya Protein ◽  
Gastric Digestion ◽  
Heat Treated ◽  
Protein Milk

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.

scholarly journals Cytotoxic effects and tolerability of gemcitabine and axitinib in a xenograft model for c-myc amplified medulloblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefanie Schwinn ◽  
Zeinab Mokhtari ◽  
Sina Thusek ◽  
Theresa Schneider ◽  
Anna-Leena Sirén ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Tumor Growth ◽  
Intensive Therapy ◽  
Xenograft Model ◽  
Light Sheet ◽  
Tumor Control ◽  
Orthotopic Model ◽  
Group 3 ◽  
Light Sheet Fluorescence Microscopy

AbstractMedulloblastoma is the most common high-grade brain tumor in childhood. Medulloblastomas with c-myc amplification, classified as group 3, are the most aggressive among the four disease subtypes resulting in a 5-year overall survival of just above 50%. Despite current intensive therapy regimens, patients suffering from group 3 medulloblastoma urgently require new therapeutic options. Using a recently established c-myc amplified human medulloblastoma cell line, we performed an in-vitro-drug screen with single and combinatorial drugs that are either already clinically approved or agents in the advanced stage of clinical development. Candidate drugs were identified in vitro and then evaluated in vivo. Tumor growth was closely monitored by BLI. Vessel development was assessed by 3D light-sheet-fluorescence-microscopy. We identified the combination of gemcitabine and axitinib to be highly cytotoxic, requiring only low picomolar concentrations when used in combination. In the orthotopic model, gemcitabine and axitinib showed efficacy in terms of tumor control and survival. In both models, gemcitabine and axitinib were better tolerated than the standard regimen comprising of cisplatin and etoposide phosphate. 3D light-sheet-fluorescence-microscopy of intact tumors revealed thinning and rarefication of tumor vessels, providing one explanation for reduced tumor growth. Thus, the combination of the two drugs gemcitabine and axitinib has favorable effects on preventing tumor progression in an orthotopic group 3 medulloblastoma xenograft model while exhibiting a favorable toxicity profile. The combination merits further exploration as a new approach to treat high-risk group 3 medulloblastoma.

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