Faculty Opinions recommendation of Cell-sized spherical confinement induces the spontaneous formation of contractile actomyosin rings in vitro.

2015 ◽  
Author(s):  
Ronen Zaidel-Bar
Keyword(s):  
Spontaneous Formation

In Vitro Conversion of Desoxycortisol to Cortisol by Adrenal Tissues in Ascorbic Acid Deficiency

1957 ◽  
Vol 188 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Habeeb Bacchus
Keyword(s):  
Ascorbic Acid ◽  
Ascorbic Acid Deficiency ◽  
Spontaneous Formation ◽  
Adrenal Tissue ◽  
Acid Deficiency

The influence of ascorbic acid nutrition on the ability of adrenal tissue to convert 11-desoxycortisol (compound S) to cortisol was studied. It was shown that this process of 11-beta-hydroxylation of desoxycortisol was decreased in ascorbic acid deficiency. Addition of ascorbate to preparations of normal adrenals with desoxycortisol enhanced the conversion. Ascorbate addition corrected the decreased 11-beta-hydroxylation ability of the adrenals of animals on the deficient fare for 13–25 days, but failed to affect the ability of the adrenals of animals on the fare for 35 days. Ascorbate decreased ( P < 0.01) the spontaneous formation of 17-OH,20,21-ketol corticosteroids by normal adrenals. The decreased spontaneous formation of these substances by the ascorbic acid deficient adrenal is corrected by ascorbate.

Cell-sized spherical confinement induces the spontaneous formation of contractile actomyosin rings in vitro

2015 ◽  
Vol 17 (4) ◽  
pp. 480-489 ◽  
Author(s):  
Makito Miyazaki ◽  
Masataka Chiba ◽  
Hiroki Eguchi ◽  
Takashi Ohki ◽  
Shin’ichi Ishiwata
Keyword(s):  
Spontaneous Formation

scholarly journals Spontaneous Formation of Melanin from Dopamine in the Presence of Iron

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1285
Author(s):  
David M. Hedges ◽  
Jordan T. Yorgason ◽  
Andrew W. Perez ◽  
Nathan D. Schilaty ◽  
Benjamin M. Williams ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Brain Slices ◽  
Fast Scan Cyclic Voltammetry ◽  
Spontaneous Formation ◽  
Ir Spectrophotometry ◽  
Da Release

Parkinson’s disease is associated with degeneration of neuromelanin (NM)-containing substantia nigra dopamine (DA) neurons and subsequent decreases in striatal DA transmission. Dopamine spontaneously forms a melanin through a process called melanogenesis. The present study examines conditions that promote/prevent DA melanogenesis. The kinetics, intermediates, and products of DA conversion to melanin in vitro, and DA melanogenesis under varying levels of Fe3+, pro-oxidants, and antioxidants were examined. The rate of melanogenesis for DA was substantially greater than related catecholamines norepinephrine and epinephrine and their precursor amino acids tyrosine and l-Dopa as measured by UV-IR spectrophotometry. Dopamine melanogenesis was concentration dependent on the pro-oxidant species and Fe3+. Melanogenesis was enhanced by the pro-oxidant hydrogen peroxide (EC50 = 500 μM) and decreased by the antioxidants ascorbate (IC50 = 10 μM) and glutathione (GSH; IC50 = 5 μM). Spectrophotometric results were corroborated by tuning a fast-scan cyclic voltammetry system to monitor DA melanogenesis. Evoked DA release in striatal brain slices resulted in NM formation that was prevented by GSH. These findings suggest that DA melanogenesis occurs spontaneously under physiologically-relevant conditions of oxidative stress and that NM may act as a marker of past exposure to oxidative stress.

Geometric effect of the hydrogel grid structure on in vitro formation of homogeneous MIN6 cell clusters

Lab on a Chip ◽  
2014 ◽  
Vol 14 (13) ◽  
pp. 2183-2190 ◽  
Author(s):  
Chae Yun Bae ◽  
Mun-kyeong Min ◽  
Hail Kim ◽  
Je-Kyun Park
Keyword(s):  
Insulin Secretion ◽  
Cell Membrane ◽  
Grid Structure ◽  
Hexagonal Grid ◽  
Geometric Effect ◽  
Cell Clusters ◽  
Spontaneous Formation ◽  
Cell Clustering ◽  
Min6 Cell

Floating hydrogel–cell membrane constructs with a hexagonal grid structure were exploited for spontaneous formation of homogeneous MIN6 cell clustering, which can be used as pancreatic pseudo-islets enhancing insulin secretion.

scholarly journals Morphological and Molecular Analysis of In Vitro Tubular Structures from Bovine Yolk Sac-Derived MSCs

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Celina A. F. Mançanares ◽  
Vanessa Cristina de Oliveira ◽  
Lilian J. Oliveira ◽  
Maria A. Miglino ◽  
Flávio Vieira Meirelles ◽  
...  
Keyword(s):  
Age Groups ◽  
Mesenchymal Cells ◽  
Yolk Sac ◽  
Tubular Structures ◽  
Vegf Gene ◽  
Ventral Region ◽  
Blood Capillaries ◽  
Spontaneous Formation ◽  
Transmission Electron

The yolk sac is an extraembryonic membrane, of saccular form, connected to the ventral region of the embryo. It is the main source of nutrition for the embryo during the period when the placenta is not fully formed. The aim of this study was to generate tubular structures using mesenchymal stem cells from the bovine yolk sac (bYS-MSCs) and determine if these structures can be a model for in vitro vasculogenesis. The evaluation of this tissue by histochemistry revealed a strong marking of collagen fibers and PAS technique negativity. In transmission electron microscopy, cytoplasmic organelles with large nuclei were observed. The vessel formation assay on a Matrigel substrate showed that the mesenchymal cells of the yolk sac without growth factors (VEGF) are capable of forming branches, sprouting cells, and tubular structures similar to capillary blood. These tubular structures were xenotransplanted subcutaneously into the mesentery of BALB/c/nude mice; after 45 days, vascularized tissue and extensions of blood vessels around the tubular structures could be observed. Real-time PCR (qPCR) demonstrated an expression of the VEGF gene in different gestational age groups. No difference in distribution or expression was detected among groups. Our results suggest that the spontaneous formation of tubules from the yolk sac can be an experimental model to elucidate initial organogenesis and the possible formation of blood capillaries from in vitro mesenchymal cells and possible route of organoid production.

scholarly journals Preliminary evaluation of the use of bacteria isolated from the digestive tract of shrimp Litopenaeus vannamei as a source to accelerate the process of formation and development of bioflocs

2021 ◽  
Vol 43 ◽  
pp. e52219
Author(s):  
Danyela Carla Elias Soares ◽  
Jade Oliveira Abreu ◽  
Jéssica Lucinda Saldanha da Silva ◽  
Oscarina Viana de Sousa
Keyword(s):  
Bacillus Thuringiensis ◽  
Microbial Communities ◽  
Sedimentation Rate ◽  
Litopenaeus Vannamei ◽  
Bacterial Consortium ◽  
Preliminary Evaluation ◽  
Bacillus Sp ◽  
Spontaneous Formation ◽  
Staphylococcus Cohnii

This study aims at investigating to follow the formation and development of biofloc aggregates in a system with the introduction of an in vitro selected bacterial consortium (Bacillus thuringiensis, Bacillus sp., Staphylococcus cohnii) in order to induce fast formation of biofloc and to compare it to the development of spontaneous formation biofloc. Two experimental groups were evaluated for biofloc formation, SFT and IFT. The first refers to spontaneous (conventional) formation of the flocs and the second to induced formation (IFT), achieved through the consortium of potentially inducing bacteria. Both treatments presented a constant increase of bioflocs, however, in the IFT treatment, the microbial aggregates were larger and more uniform. By the end of the experiment, we verified that the aggregates formed in the IFT showed higher volume and lower sedimentation rate in comparison to the spontaneously formed ones. The results show that domestication in microbial communities is efficient as related to bioflocs, reducing instability during its formation and development.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

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