Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

Automated sequencing batch bioreactor under extreme peaks of 4-chlorophenol

2003 ◽  
Vol 47 (10) ◽  
pp. 175-181 ◽  
Author(s):  
G. Buitrón ◽  
M.-E. Schoeb ◽  
J. Moreno
Keyword(s):  
Dissolved Oxygen ◽  
Metabolic Activity ◽  
Automated System ◽  
Stable Operation ◽  
High Concentration ◽  
Batch Bioreactor ◽  
On Line ◽  
The Moment ◽  
And Control ◽  
System Operating

The operation of a sequencing batch bioreactor is evaluated when high concentration peaks of a toxic compound (4-chlorophenol, 4CP) are introduced into the reactor. A control strategy based on the dissolved oxygen concentration, measured on line, is utilized. To detect the end of the reaction period, the automated system search for the moment when the dissolved oxygen has passed by a minimum, as a consequence of the metabolic activity of the microorganisms and right after to a maximum due to the saturation of the water (similar to the self-cycling fermentation, SCF, strategy). The dissolved oxygen signal was sent to a personal computer via data acquisition and control using MATLAB and the SIMULINK package. The system operating under the automated strategy presented a stable operation when the acclimated microorganisms (to an initial concentration of 350 mg 4CP/L), were exposed to a punctual concentration peaks of 600 mg 4CP/L. The 4CP concentrations peaks superior or equals to 1,050 mg/L only disturbed the system from a short to a medium term (one month). The 1,400 mg/L peak caused a shutdown in the metabolic activity of the microorganisms that led to the reactor failure. The biomass acclimated with the SCF strategy can partially support the variations of the toxic influent since, at the moment in which the influent become inhibitory, there is a failure of the system.

Hydra regeneration from recombined ectodermal and endodermal tissue. I. Epibolic ectodermal spreading is driven by cell intercalation

1996 ◽  
Vol 109 (4) ◽  
pp. 763-772 ◽  
Author(s):  
Y. Kishimoto ◽  
M. Murate ◽  
T. Sugiyama
Keyword(s):  
Contact Surface ◽  
Single Cells ◽  
Cell Interaction ◽  
Inhibitory Effect ◽  
Cell Aggregates ◽  
Signaling Mechanism ◽  
Initial Adhesion ◽  
Radial Cell ◽  
Epithelial Sheet ◽  
Cell Intercalation

Cell-cell interaction and cell rearrangement were examined in the process of epithelial sheet formation during regeneration from hydra cell aggregates. The ectodermal and endodermal epithelial cell layers of Hydra magnipapillata were separated by procaine treatment. Each of the separated layers was then dissociated into single cells and reaggregated to produce ectodermal or endodermal cell aggregates. When the two aggregate types were recombined, a firm adhesion was quickly established between them. This was followed by a vigorous spreading of the ectodermal epithelial cells as a thin layer over the endoderm in a manner similar to the ‘epiboly’ in some developing embryos. Cell movement in this spreading process was examined using fluorescent dyestaining. It revealed that cells initially located in the inside of the aggregate migrated to intercalate themselves among the cells originally present in the contact surface. This radial cell intercalation took place continuously in the contact surface of both the ectodermal and endodermal aggregates, and produced a rapid growth of the contact surface, eventually leading to complete envelopment of the entire endoderm by the ectoderm. The resulting structure was a small sphere having a two-layered epithelial organization as in normal hydra. This sphere regenerated into a complete hydra a few days later. A tryptic extract of hydra membrane fraction specifically inhibited the ectodermal spreading over the endoderm, but not the initial adhesion or the later regeneration processes. These observations suggest that radial cell intercalation at the contact surface plays a crucial role in producing ectodermal spreading and establishing epithelial sheet organization in the recombined aggregates. The intercalation is presumably activated by a signal exchange through the contact surface. The inhibitory effect of the membrane extract suggests that it contains a factor that is involved in some way in this signaling mechanism.

The Use of Fluorometry in Monitoring and Control of Cell Cultures

1989 ◽  
pp. 309-320 ◽  
Author(s):  
Arthur E. Humphrey ◽  
Kendall Brown ◽  
John Horvath ◽  
Hratch Semerjian
Keyword(s):  
Cell Cultures ◽  
Monitoring And Control ◽  
And Control

Normal incorporation rates for precursors of collagen and mucopolysaccharide during expression of micromelia induced by 6-aminonicotinamide

Development ◽  
1974 ◽  
Vol 31 (2) ◽  
pp. 305-312
Author(s):  
Robert E. Seegmiller ◽  
Meredith N. Runner
Keyword(s):  
Core Protein ◽  
Limb Bud ◽  
Matrix Proteins ◽  
Synthesis Rate ◽  
Control Groups ◽  
In Ovo ◽  
Limb Buds ◽  
Radioactive Precursor ◽  
Hind Limbs ◽  
And Control

Further delineation of mechanisms by which 6-aminonicotinamide (6-AN) induces micromelia in the chick embryo was investigated by studies on rates of incorporation of thymidine, proline, glucosamine and sulfate as precursors to DNA, collagen and mucopolysaccharide, respectively. Twenty-four hours after in ovo administration of the vitamin antagonist, 6-AN, to day-4 chick embryos, hind limbs from experimental and control groups were excised and incubated for 1 h in medium containing 3 × 10−6m radioactive precursor. Molar incorporation of precursors into the TCA-precipitable fraction showed, in isolated limb buds, (a) that 6-AN enhanced incorporation of thymidine, (b) that 6-AN inhibited utilization of sulfate, and (c) that 6-AN did not significantly alter utilization of glucosamine and proline. Rates of incorporation of thymidine, glucosamine and proline indicate that 6-AN is not cytotoxic to the isolated limb bud. Enhanced incorporation of thymidine suggests expression of compensatory change 24 h after initial effects of 6-AN on DNA synthesis. Rate of incorporation of proline suggests that, under the influence of 6-AN, tropocollagen was synthesized in normal quantities by limb cells. Similarly, rate of incorporation of glucosamine suggests that under the influence of 6-AN normal amounts of hexosamine sugars were being attached to the nascent core-protein of chondroitin. Inhibition of sulfation and failure to complete the chondroitin sulfate molecule seem to account for 6-AN-induced micromelia. This suggests that sulfation depends upon specific NAD-dependent dehydrogenase reactions. As far as can be established by rates of incorporation of labeled precursors, 5-day limb buds, at 24 h after exposure to teratogenic levels of 6-AN, synthesize matrix proteins and hexosamine polysaccharides at normal rates.

scholarly journals Single-nuclei RNA-seq on human retinal tissue provides improved transcriptome profiling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Qingnan Liang ◽  
Rachayata Dharmat ◽  
Leah Owen ◽  
Akbar Shakoor ◽  
Yumei Li ◽  
...  
Keyword(s):  
Single Cell ◽  
Transcriptome Profiling ◽  
Cell Types ◽  
Retinal Cell ◽  
Peripheral Retina ◽  
Marker Genes ◽  
Rna Seq ◽  
Cell Type ◽  
Retinal Tissue ◽  
The Individual

AbstractSingle-cell RNA-seq is a powerful tool in decoding the heterogeneity in complex tissues by generating transcriptomic profiles of the individual cell. Here, we report a single-nuclei RNA-seq (snRNA-seq) transcriptomic study on human retinal tissue, which is composed of multiple cell types with distinct functions. Six samples from three healthy donors are profiled and high-quality RNA-seq data is obtained for 5873 single nuclei. All major retinal cell types are observed and marker genes for each cell type are identified. The gene expression of the macular and peripheral retina is compared to each other at cell-type level. Furthermore, our dataset shows an improved power for prioritizing genes associated with human retinal diseases compared to both mouse single-cell RNA-seq and human bulk RNA-seq results. In conclusion, we demonstrate that obtaining single cell transcriptomes from human frozen tissues can provide insight missed by either human bulk RNA-seq or animal models.

Induction of apoptosis in rat retinal cell cultures by partially fluorinated alkanes

2005 ◽  
Vol 139 (4) ◽  
pp. 737-739 ◽  
Author(s):  
Fiorella Malchiodi-Albedi ◽  
Andrea Matteucci ◽  
Giuseppe Formisano ◽  
Silvia Paradisi ◽  
Giovanna Carnovale-Scalzo ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Retinal Cell ◽  
Induction Of Apoptosis

Mitochondrial Inhibition in Rat Retinal Cell Cultures as a Model of Metabolic Compromise: Mechanisms of Injury and Neuroprotection

2012 ◽  
Vol 53 (8) ◽  
pp. 4897 ◽  
Author(s):  
John P. M. Wood ◽  
Teresa Mammone ◽  
Glyn Chidlow ◽  
Tim Greenwell ◽  
Robert J. Casson
Keyword(s):  
Cell Cultures ◽  
Retinal Cell

scholarly journals Colony formation of clone-sorted human hematopoietic progenitors

Blood ◽  
1990 ◽  
Vol 75 (10) ◽  
pp. 1941-1946 ◽  
Author(s):  
H Ema ◽  
T Suda ◽  
Y Miura ◽  
H Nakauchi
Keyword(s):  
Single Cell ◽  
Cell Cultures ◽  
Mononuclear Cells ◽  
Direct Action ◽  
Single Cells ◽  
Accurate Estimation ◽  
Hematopoietic Progenitors ◽  
Gm Csf ◽  
Cd34 Cells ◽  
Sorting System

Abstract To characterize human hematopoietic progenitors, we performed methylcellulose cultures of single cells isolated from a population of CD34+ cells by fluorescence-activated cell-sorting (FACS) clone-sorting system. CD34+ cells were detected in bone marrow (BM) and peripheral blood (PB) cells at incidences of 1.0% and 0.01% of total mononuclear cells, respectively. Single cell cultures revealed that approximately 37% of BM CD34+ cells formed colonies in the presence of phytohemagglutinin-leukocyte conditioned medium and erythropoietin. Erythroid bursts-, granulocyte-macrophage (GM) colony-, and pure macrophage (Mac) colony-forming cells were 10% each in CD34+ cells. Approximately 15% of PB CD34+ cells formed colonies in which erythroid bursts were predominant. CD34+ cells were heterogeneous and fractionated by several antibodies in FACS multicolor analysis. In these fractionated cells, CD34+, CD33+ cells formed GM and Mac colonies 7 to 10 times as often as CD34+, CD33- cells. Most of the erythroid bursts and colonies were observed in the fraction of CD34+, CD13- cells or CD34+, CD33- cells. The expression of HLA-DR on CD34+ cells was not related to the incidence, size, or type of colonies. There was no difference in the phenotypical heterogeneity of CD34+ cells between BM and PB. About 10% of CD34+ cells were able to form G colonies in response to granulocyte colony-stimulating factor (G-CSF) and to form Mac colonies in GM-CSF or interleukin-3 (IL-3). Progenitors capable of generating colonies by stimulation of G-CSF were more enriched in CD34+, CD33+ fraction than in CD34+, CD33- fraction. Thus, single cell cultures using the FACS clone-sorting system provide an accurate estimation of hematopoietic progenitors and an assay system for direct action of colony-stimulating factors.

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