An experimental study of eye development in the cephalopod Loligo vulgaris: determination and regulation during formation of the primary optic vesicle

Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 347-361
Author(s):  
H.-J. Marthy
Keyword(s):  
Experimental Study ◽  
Outer Layer ◽  
Optic Vesicle ◽  
Experimental Conditions ◽  
Differentiation Capacity ◽  
Nutritional Conditions ◽  
Transplantation Experiments ◽  
Eye Formation

By a series of explantation, transplantation (yolk syncytium left intact) and incision experiments done with the eye rudiment during the stages VI–IX (Naef, 1923) it is concluded that the yolk syncytium does not induce the differentiation of ‘the outer layer of cells’ from stage VI on as suggested by Arnold (1965 b). From the explantation and transplantation experiments the author draws the conclusion that there exists, from stage VI on, in the ‘outer layer of cells’ on each side of the embryo, an area which contains all factors necessary for eye formation and which manifests itself, under experimental conditions, in regulation. The explanted eye rudiment shows in vitro autonomous differentiation capacity only if nutritional conditions are sufficient. The incision experiments elucidate the role of ‘contractile elements’ in organo-genesis. Arnold's results are discussed.

Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

Role of nutrient HCO3(-) in protection of amphibian gastric mucosa

1980 ◽  
Vol 239 (6) ◽  
pp. G536-G542
Author(s):  
R. Schiessel ◽  
A. Merhav ◽  
J. B. Matthews ◽  
L. A. Fleischer ◽  
A. Barzilai ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Experimental Conditions ◽  
Slow Decline ◽  
Alkaline Tide ◽  
Artificial Gastric Juice ◽  
Rapid Drop

In in vitro bullfrog fundic mucosa inhibited with 10(-3) M metiamide and exposed to a luminal pH of 2 a progressive slow decline in potential difference (PD) and short-circuit current (Isc) and a rise in resistance (R) were observed when the nutrient solution (N) contained 18 mM HCO3(-), but these changes were restored by an N containing 50 mM HCO3(-). Substitution of PO4(3-) or N-tris(hydroxymethyl)-methyl-2-aminoethanesulfonic acid for NHO3(-) in N caused a rapid drop in PD and Isc in inhibited tissues, changes that could be prevented by 10(-4) M histamine. Ulceration occurred more frequently in metiamide-inhibited gastric sacs exposed to artificial gastric juice with an N of 18 mMHCO3(-) than with 50 mM HCO3(-), but histamine prevented ulceration in the 18 mM HCO3(-) solution. JnetCl approximated Isc under most experimental conditions in inhibited mucosa and was reduced dramatically as were both Jn leads to sCl and Js leads to nCl when HCO3(-) was removed from N. In histamine-stimulated tissues, removal of nutrient HCO3(-) did not influence Cl- transport. Our results are consistent with the proposal that HCO3(-) in N supports normal Cl- flux and that the alkaline tide of actively secreting oxyntic cells can do the same in the absence of ambient HCO3(-).

Anionic and cationic exchange mechanisms in the skin of anurans, with special reference to Leptodactylidae in vivo

1971 ◽  
Vol 262 (842) ◽  
pp. 163-174 ◽  
Keyword(s):  
Transport Mechanism ◽  
Selective Inhibition ◽  
The Other ◽  
Sodium Absorption ◽  
Experimental Conditions ◽  
Net Flux ◽  
Cationic Exchange

In several species of anurans, the in vivo skin has been shown to absorb Na + and Cl - independently from dilute external solutions. That the mechanism for sodium absorption is different from that of chloride absroption is born out by the following: (1) Either of these ions is absorbed without an accompanying ion when this latter is impermeant. (2) From NaCl solutions there can be an unequal absorption of sodium and chloride. (3) A selective inhibition of the absorption of one of the ions can be produced experimentally, while the net flux of the other remains unchanged. In all these situations, the absorbed ion has to be exchanged against an endogenous ion of the same charge. In Calyptocephalella gayi , H + and HCO - 3 are exchanged against sodium and chloride respectively. A comparison of the relationships between H + excretion and Na + absorption in vivo skins and shortcircuited in vitro skins shows that in the latter no H + excretion occurs, only the Na + transport being maintained under these experimental conditions. From this, one must conclude that the active Na + transport is the motive factor of the transport mechanism. H + excretion by the in vivo skin plays the role of physiologically short-circuiting the Na + transport.

scholarly journals RELATIONSHIP BETWEEN THE GENOME PACKING IN THE BACTERIOPHAGE CAPSID AND THE KINETICS OF DNA EJECTION

2014 ◽  
Vol 09 (01) ◽  
pp. 81-104 ◽  
Author(s):  
M. DE FRUTOS ◽  
A. LEFORESTIER ◽  
F. LIVOLANT
Keyword(s):  
Dna Structure ◽  
General Survey ◽  
Experimental Conditions ◽  
Dna Ejection ◽  
Ejection Process ◽  
Dna Organization ◽  
Kinetics Of

We present a general survey of experimental and theoretical observations of DNA structure and in vitro ejection kinetics for different bacteriophage species. In some species, like T5, the ejection may present pauses and arrests that have not been detected in others species like Lambda. We propose hypotheses to explain such differences and we discuss how the experimental conditions may be important for their detection. Our work highlights the role of DNA organization inside the bacteriophage capsid on the stochastic and out of equilibrium nature of the ejection process.

scholarly journals The Role of F11R in Pancreatic Cancer Malignancy and Its Clinical Implication as a Therapeutic Target

2019 ◽  
Author(s):  
Haidi zhang ◽  
Chunyan Zhao ◽  
Xianhua Hu ◽  
Shuai He ◽  
Jinchuan Yu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Therapeutic Target ◽  
Immunoglobulin Superfamily ◽  
Experimental Conditions ◽  
Cycle Arrest ◽  
Pancreatic Cancer Cells ◽  
Promising Therapeutic Target ◽  
Cell Invasiveness

Abstract Abstract Background The F11 receptor belongs to the immunoglobulin superfamily and is expressed in epithelial and endothelial cells. F11R mediates the formation of tight junctions between the epithelium and endothelium, and participates in the invasion and metastasis of tumor cells. We have previously shown that the F11R gene is closely related to KRas (P= 0.76), a known therapeutic target for pancreatic cancer (PCa). In recent years, it has been found that F11R is expressed in different tumors and has biological effects.However, according to different tumor cases, different cell lines and experimental conditions, the regulatory results and mechanisms of F11R on tumor are different, even contradictory,and the expression, clinical significance and biological mechanism of F11R in tumor tissues have not been reported in detail. Results To investigate the role of F11R in carcinogenesis of PCa and the potential of F11R as a therapies target for PCa, we silenced F11R (-/-) in the PCa cell line PANC-1 (known to express high levels of KRas) using lentiviral approaches.We found that F11R silencing led to decreased cell proliferation, a loss of cell invasiveness, reduced colony forming ability, cell cycle arrest in G1 phase, cells apoptosis enhanced, and ros enhanced. In vitro data showed that inhibition of F11R decreased proliferation and invasiveness of cancer cells.The present results suggest that F11R may be a promising therapeutic target for PCa. Conclusions This study used bioinformatics combined with gene chip data to find the gene F11R, which is closely related to KRAS gene, and we used lentivirus to package shRNA plasmid to interfere with the gene F11R in pancreatic cancer panc-1 cells. A series of biobehavioral studies indicated the biobehavioral function and malignancy of panc-1 in pancreatic cancer cells with negative regulation of F11R gene.Based on this, we need to continue to clarify the expression of F11R gene in clinical case samples to determine whether F11R gene can be a new therapeutic target for pancreatic cancer.

scholarly journals Role of the Thrombin-PAR-1 Pathway in Coxsackievirus Induced Hepatitis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1470-1470
Author(s):  
Kohei Tatsumi ◽  
Silvio Antoniak ◽  
Nigel Mackman
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Primary Mouse Hepatocytes ◽  
Primary Mouse ◽  
Mouse Hepatocytes ◽  
Transplantation Experiments

Abstract Objective: Coxsackievirus B3 (CVB3) can infect different tissues including the heart and liver. Recently, we found that activation of the coagulation cascade and protease-activated receptor 1 (PAR-1) enhances toll-like receptor-3 (TLR3) mediated interferon-β (IFN-β) expression and protects mice from CVB3-induced myocarditis. Here, we investigated the role of PAR-1 in early anti-viral responses in mice and isolated hepatocytes. Methods: Wild-type (WT) and PAR-1 deficient (PAR-1-/-) mice were infected with CVB3 intraperitoneally. The innate immune response, viral load, liver enzyme plasma levels, and inflammation levels were analyzed. Bone-marrow transplantation experiments with the combination of WT mice PAR-1-/- mice were performed to identify the cellular source of PAR-1 contributing to the innate immune response to CVB3. We also analyzed the effect of the direct thrombin inhibition with dabigatran etexilate on CVB3 hepatitis. In addition, we analyzed the effect of PAR-1 activation on TLR3-dependent interferon (IFN)-β expression in primary mouse hepatocytes and the human hepatocyte cell line PH5CH8 in vitro. Results: PAR-1-/- mice exhibited a reduced early innate immune response in the liver at day 4 after infection, which was associated at later times (day 8) to higher viral titers in the liver, increased alanine transaminase plasma levels and more remarkable inflammation compared to control WT mice. Bone marrow transplantation experiments demonstrated that PAR-1 on non-hematopoietic played the major role in the innate immune response of CVB3 hepatitis. Stimulation of PAR-1 with either thrombin or agonist peptide on primary mouse hepatocytes and human PH5CH8 cells in vitro enhanced the antiviral response to dsRNA by increasing IFN-β and C-X-C motif chemokine 10 (CXCL10) expressions, supporting the results of in vivo experiments. Conclusion: Our results suggest that activation of PAR-1 on hepatocytes enhances the innate immune response to CVB3 in the liver. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Role of GRASP55 in Golgi Fragmentation and Entry of Cells into Mitosis

2008 ◽  
Vol 19 (6) ◽  
pp. 2579-2587 ◽  
Author(s):  
Juan Manuel Duran ◽  
Matt Kinseth ◽  
Carine Bossard ◽  
David W. Rose ◽  
Roman Polishchuk ◽  
...  
Keyword(s):  
Peptide Mapping ◽  
Full Length ◽  
Wild Type ◽  
Experimental Conditions ◽  
Golgi Membranes ◽  
Golgi Fragmentation ◽  
Per Se ◽  
Golgi Organization

GRASP55 is a Golgi-associated protein, but its function at the Golgi remains unclear. Addition of full-length GRASP55, GRASP55-specific peptides, or an anti-GRASP55 antibody inhibited Golgi fragmentation by mitotic extracts in vitro, and entry of cells into mitosis. Phospho-peptide mapping of full-length GRASP55 revealed that threonine 225 and 249 were mitotically phosphorylated. Wild-type peptides containing T225 and T249 inhibited Golgi fragmentation and entry of cells into mitosis. Mutant peptides containing T225E and T249E, in contrast, did not affect Golgi fragmentation and entry into mitosis. These findings reveal a role of GRASP55 in events leading to Golgi fragmentation and the subsequent entry of cell into mitosis. Surprisingly, however, under our experimental conditions, >85% knockdown of GRASP55 did not affect the overall organization of Golgi organization in terms of cisternal stacking and lateral connections between stacks. Based on our findings we suggest that phosphorylation of GRASP55 at T225/T249 releases a bound component, which is phosphorylated and necessary for Golgi fragmentation. Thus, GRASP55 has no role in the organization of Golgi membranes per se, but it controls their fragmentation by regulating the release of a partner, which requires a G2-specific phosphorylation at T225/T249.

scholarly journals Does the Apoptosis Value of Cumulus Cells Play a Role in Rescue Oocyte in Vitro Maturation?

2020 ◽  
pp. 1
Author(s):  
Tulay Irez ◽  
Sinem Ercan Dogan ◽  
Enver Ciraci ◽  
Saadet Busra Aksoyer ◽  
Muhammet Sait Toprak ◽  
...  
Keyword(s):  
Experimental Study ◽  
Luteinizing Hormone ◽  
Embryo Development ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Immature Oocytes ◽  
Maturation Rate

<p><strong>OBJECTIVE:</strong> In this study, we aimed to investigate the role of the cumulus cell’s apoptosis parameter in the maturation of immature rescue oocytes. </p><p><strong>STUDY DESIGN:</strong> In this experimental study, donated immature germinal vesicle oocytes were cultured for, in vitro maturation, embryo development in matured germinal vesicle oocytes were compared with apoptotic properties of cumulus cells. </p><p><strong>RESULTS:</strong> In all of the immature oocytes after oocyte in vitro maturation, the maturation rate has been observed as 56.1% and 2PN rate as 63.0%. Afterin vitro maturation of germinal vesicle oocytes, there was no difference in apoptosis rates of the cumulus cells between mature and immature oocytes (p&gt; 0.05). The ratio of 2PN in matured germinal vesicle oocytes showing embryo development was 35.4%. A positive correlation was found between luteinizing hormone values on day 3 and E2 values during HCG days during oocyte maturation and embryo development (p=0.021, p=0.020). In addition, it has been observed that the germinal vesicle oocytes, which have completed their maturation and developed into embryos, have high E2 values during HCG days (p=0.020).</p><p><strong>CONCLUSION:</strong> In our study, it has been demonstrated that in vitro maturation in rescue oocytes from stimulated cycles, embryo development potential could not be explained by the apoptosis parameter.</p>

Reinvestigation of the role of the optic vesicle in embryonic lens induction

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 517-526 ◽  
Author(s):  
R.M. Grainger ◽  
J.J. Herry ◽  
R.A. Henderson
Keyword(s):  
Xenopus Laevis ◽  
Optic Vesicle ◽  
Multistep Process ◽  
Optic Vesicles ◽  
Original Report ◽  
Lens Formation ◽  
Embryonic Ectoderm ◽  
Transplantation Experiments ◽  
Xenopus Laevis Embryos

The induction of the lens by the optic vesicle in amphibians is often cited as support for the view that a single inductive event can lead to determination in a multipotent tissue. This conclusion is based on transplantation experiments whose results indicate that many regions of embryonic ectoderm which would normally form epidermis can form a lens if brought into contact with the optic vesicle. Although additional evidence argues that during normal development other tissues, acting before the optic vesicle, also contribute to lens induction, it is still widely held, on the basis of these transplantation experiments, that the optic vesicle alone can elicit lens formation in ectoderm. While testing this conclusion by transplanting optic vesicles beneath ventral ectoderm in Xenopus laevis embryos, it became apparent that contamination of optic vesicles by presumptive lens ectoderm cells can generate lenses in these experiments, illustrating the need for adequate host and donor marking procedures. Since previous studies rarely used host and donor marking, it was not clear whether they actually demonstrated that the optic vesicle can induce lenses. Using careful host and donor marking procedures with horseradish peroxidase as a lineage tracer, we show that the optic vesicle cannot stimulate lens formation in neurula- or gastrula-stage ectoderm of Xenopus laevis. Since the general conclusion that the optic vesicle is sufficient for lens induction rests on studies in many organisms, we felt it was important to begin to test this conclusion in other amphibians as well. Similar experiments were therefore performed with Rana Palustris embryos, since it was in this organism that optic vesicle transplant studies had originally argued that this tissue alone can cause lens induction. Under conditions similar to those used in the original report, but with careful controls to assess the origin of lenses in transplants, we found that the optic vesicle alone cannot elicit lens formation. Our data lead us to propose that the optic vesicle in amphibians is not generally sufficient for lens induction. Instead, we argue that lens induction occurs by a multistep process in which an essential phase in lens determination occurs as a result of inductive interactions preceding contact of ectoderm with the optic vesicle.

Interaction of Measles Virus Vectors with Auger Electron Emitting Radioisotopes.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5525-5525
Author(s):  
David Dingli ◽  
Kah-Whye Peng ◽  
Mary E. Harvey ◽  
Sompong Vongpunsawad ◽  
Elizabeth R. Bergert ◽  
...  
Keyword(s):  
Measles Virus ◽  
Auger Electron ◽  
Viral Vectors ◽  
Soluble Form ◽  
Sodium Iodide Symporter ◽  
Experimental Conditions ◽  
Oncolytic Activity

Abstract Background: Viral vectors based on the Edmonston strain of measles virus (MV-Edm) selectively destroy all tumor cell lines tested in vitro. The oncolytic activity of the virus is enhanced by expression of the thyroidal sodium iodide symporter (MV-NIS) that allows selective 131I uptake by infected tumor cells and eliminates myeloma tumor xenografts that are resistant to the parent virus. MV-NIS is being considered for therapy of patients with relapsed or refractory multiple myeloma. Advanced myeloma is associated with significant immunosuppression with the potential risk of uncontrolled virus proliferation. The number of agents with activity against MV is limited. Low energy (Auger) electrons have a short path length and selectively damage cells in which the isotope decays. Thus, we hypothesized that the Auger electron emitting isotope 125I, selectively taken up by cells expressing NIS, can be used to control viral proliferation. Methods: A replication competent MV that expressed both a soluble form of carcinoembryonic antigen (CEA) and NIS (MV-NICE) was rescued and characterized. Cells were infected with MV-NICE or control vectors and exposed to 125I with appropriate controls. CEA expression and viral titers were determined at different time points. The role of free radical generation on virus replication was explored. In vivo control of MV-NICE replication with 125I was attempted. Results: MV-NICE replication in vitro is inhibited by the selective uptake of 125I by cells expressing NIS. Extracellular decay of the isotope has no effect on virus proliferation. Auger electron damage is in part mediated by free radicals and abrogated by glutathione. In myeloma xenografts, control of MV-NICE with 125I was not possible under the conditions of the experiment. Conclusion: MV-NICE does not replicate faster in the presence of radiation under our experimental conditions. Auger electron emitting isotopes effectively stop propagation of MV vectors expressing NIS in vitro. Additional work is necessary to translate these observations in vivo.

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