Factors affecting the time of formation of the mouse blastocoele

Development ◽  
1977 ◽  
Vol 41 (1) ◽  
pp. 79-92
Author(s):  
Rosita Smith ◽  
Anne McLaren
Keyword(s):  
Cytochalasin B ◽  
Critical Factor ◽  
Cell Number ◽  
Experimental Manipulation ◽  
Factors Affecting ◽  
Elapsed Time ◽  
Developmental Age ◽  
Culture Formation

In normal mouse embryos developing in vivo, the first appearance of the blastocyst cavity was found to be associated more closely with developmental age, judged by cell number, than with chronological age, i.e. elapsed time since ovulation. When development was slowed by in vitro culture, formation of the blastocoele was delayed. However, cell number itself was not a critical factor, since the number of cells per embryo could be doubled or tripled or halved by experimental manipulation without substantially affecting the timing of blastocoele formation. Experiments in which one cell division was suppressed with cytochalasin-B, leading to tetraploidy, showed that the number of cell divisions since fertilization was also not critical. A possible role is suggested either for nucleocytoplasmic ratio, or for the number of nuclear or chromosomal divisions or DNA replications since fertilization, all of which increase during cleavage.

Superfine open pulled straws vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation

2010 ◽  
Vol 22 (5) ◽  
pp. 808 ◽  
Author(s):  
C. Cuello ◽  
J. Sanchez-Osorio ◽  
C. Almiñana ◽  
M. A. Gil ◽  
I. Parrilla ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochalasin B ◽  
Cell Number ◽  
Total Cell Number ◽  
Grade Ii ◽  
Vitro Development ◽  
Cytoskeletal Disruption ◽  
Hatching Rates

The present study investigated the in vitro development of and cytoskeletal disruption suffered by in vivo-derived porcine blastocysts subjected to superfine open pulled straws (SOPS) vitrification. Blastocysts were either untreated prior to SOPS vitrification or were subjected to one of the following three pretreatment protocols: (1) centrifugation (12 min, 13 000g); (2) 25 min equilibration with 7.5 μg mL–1 cytochalasin B; or (3) equilibration with cytochalasin B followed by centrifugation. After 24 h culture, fresh (n = 32) and vitrified–warmed (n = 188) blastocysts were evaluated by stereomicroscopy, with survival and hatching rates recorded. Some blastocysts were stained with 4′,6′-diamidino-2-phenylindole and processed for cytoskeletal evaluation. Three cytoskeletal patterns were identified: Grade I, intact cytoskeleton; Grade II, gross maintenance of integrity, but with some clumps of actin within the cytoplasm; and Grade III, a highly disrupted cytoskeleton. There were no differences in the survival, hatching and cell death rats, total cell number or cytoskeletal integrity between the different vitrification groups. Cell death was greater for vitrified blastocysts than for fresh blastocysts (3.6 ± 0.4% v. 0.4 ± 0.7%, respectively; P < 0.05) and the percentage of blastocysts with a Grade I cytoskeletal pattern was lower for vitrified compared with fresh blastocysts (60.8% v. 92%, respectively; P < 0.05). The vitrified–warmed blastocysts that hatched during culture exhibited a Grade I cytoskeletal pattern. In conclusion, successful SOPS vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation.

Induction of triploidy in the mouse by cytochalasin B

Development ◽  
1975 ◽  
Vol 34 (2) ◽  
pp. 279-289
Author(s):  
Anna Niemierko
Keyword(s):  
Culture Medium ◽  
Cytochalasin B ◽  
Sex Chromosome ◽  
Polar Body ◽  
Cell Number ◽  
Second Polar Body ◽  
And Control ◽  
Mouse Eggs

Mouse eggs fertilized in vivo were treated with cytochalasin B in vitro (5 μg/ml of culture medium) at he moment of extrusion of the second polar body (2·5, 3·0, 3·5 h after copulation). Cytochalasin B inhibits cytokinesis of the second maturation division, so that triploid digynic eggs are formed in over 50% of treated eggs. Triploid eggs were transplanted to the oviducts of recipients. On the 4th and 5th day of development 41·7% of transplanted eggs were recovered. All embryos recovered on the 4th day were morulae, while on the 5th day blastocysts predominated. Recovered embryos were studied for cell number and ploidy. Twenty-three of 27 embryos with analysable metaphase plates were triploid and four were diploid (the latter were found in females into which both triploid and control diploid eggs were transplanted). Sex chromosome constitution was determined in seven cases: four triploids were XXY and three were XXX.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

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.

Maturation, iron deficiency, and ligands in enteric radioiron transport in vitro

1963 ◽  
Vol 204 (1) ◽  
pp. 171-175 ◽  
Author(s):  
W. S. Ruliffson ◽  
J. M. Hopping
Keyword(s):  
Ascorbic Acid ◽  
Iron Deficiency ◽  
Iron Absorption ◽  
Deficiency Anemia ◽  
Anaerobic Incubation ◽  
Reverse Effect ◽  
Factors Affecting ◽  
Everted Gut Sac

The effects in rats, of age, iron-deficiency anemia, and ascorbic acid, citrate, fluoride, and ethylenediaminetetraacetate (EDTA) on enteric radioiron transport were studied in vitro by an everted gut-sac technique. Sacs from young animals transported more than those from older ones. Proximal jejunal sacs from anemic animals transported more than similar sacs from nonanemic rats, but the reverse effect appeared in sacs formed from proximal duodenum. When added to media containing ascorbic acid or citrate, fluoride depressed transport as did anaerobic incubation in the presence of ascorbic acid. Anaerobic incubation in the presence of EDTA appeared to permit elevated transport. Ascorbic acid, citrate, and EDTA all enhanced the level of Fe59 appearing in serosal media. These results appear to agree with previously established in vivo phenomena and tend to validate the in vitro method as one of promise for further studies of factors affecting iron absorption and of the mechanism of iron absorption.

The preimplantation pig embryo: cell number and allocation to trophectoderm and inner cell mass of the blastocyst in vivo and in vitro

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 793-803 ◽  
Author(s):  
V.E. Papaioannou ◽  
K.M. Ebert
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Staining Technique ◽  
Cell Number ◽  
Total Cell ◽  
Differential Staining ◽  
Morphological Development ◽  
Total Cell Number

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from different females. Inner cells could be detected in some but not all embryos of 12–16 cells. The proportion of inner cells was low in morulae but increased during differentiation of ICM and trophectoderm in early blastocysts. The proportion of ICM cells then decreased as blastocysts expanded and hatched. Some embryos were cultured in vitro and others were transferred to the oviducts of immature mice as a surrogate in vivo environment and assessed for morphology and cell number after several days. Although total cell number did not reach in vivo levels, morphological development and cell number increase was sustained better in the immature mice than in vitro. The proportion of ICM cells in blastocysts formed in vitro was in the normal range.

The mechanism of mouse egg-cylinder morphogenesis in vitro

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 277-287
Author(s):  
A. J. Copp
Keyword(s):  
Giant Cell ◽  
Cell Formation ◽  
Cell Movement ◽  
Giant Cells ◽  
Cell Number ◽  
Dependent Change ◽  
Morphogenesis In Vitro ◽  
Trophoblast Giant Cells

The number of trophoblast giant cells in outgrowths of mouse blastocysts was determined before, during and after egg-cylinder formation in vitro. Giant-cell numbers rose initially but reached a plateau 12 h before the egg cylinder appeared. A secondary increase began 24 h after egg-cylinder formation. Blastocysts whose mural trophectoderm cells were removed before or shortly after attachment in vitro formed egg cylinders at the same time as intact blastocysts but their trophoblast outgrowths contained fewer giant cells at this time. The results support the idea that egg-cylinder formation in vitro is accompanied by a redirection of the polar to mural trophectoderm cell movement which characterizes blastocysts before implantation. The resumption of giant-cell number increase in trophoblast outgrowths after egg-cylinder formation may correspond to secondary giant-cell formation in vivo. It is suggested that a time-dependent change in the strength of trophoblast cell adhesion to the substratum occurs after blastocyst attachment in vitro which restricts the further entry of polar cells into the outgrowth and therefore results in egg-cylinder formation.

scholarly journals Bioinformatic and experimental findings to indicate anti-cancer targets and mechanisms of calycosin against nasopharyngeal carcinoma

2020 ◽  
Author(s):  
Fangxian Liu ◽  
Qijin Pan ◽  
Liangliang Wang ◽  
Shijiang Yi ◽  
Peng Liu ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Cell Number ◽  
Network Pharmacology ◽  
Tunel Staining ◽  
Pharmacological Targets ◽  
Experimental Findings

Abstract Background: Calycosin is a naturally-occurring phytoestrogen that reportedly exerts anti- nasopharyngeal carcinoma (NPC) effects. Nevertheless, the molecular mechanisms for anti-NPC using calycosin remain unrevealed. Methods: Thus, a network pharmacology was used to uncover anti-NPC pharmacological targets and mechanisms of calycosin. Additionally, validated experiments were conducted to validate the bioinformatic findings of calycosin for treating NPC. Results: As results, bioinformatic assays showed that the predictive pharmacological targets of calycosin against NPC were TP53, MAPK14, CASP8, MAPK3, CASP3, RIPK1, JUN, ESR1, respectively. And the top 20 biological processes and pharmacological mechanisms of calycosin against NPC were identified accordingly. In clinical data, NPC samples showed positive expression of MAPK14, reduced TP53, CASP8 expressions. In studies in vitro and in vivo, calycosin-dosed NPC cells resulted in reduced cell proliferation, promoted cell apoptosis. In TUNEL staining, calycosin exhibited elevated apoptotic cell number. And immunostaining assays resulted in increased TP53, CASP8 positive cells, and reduced MAPK14 expressions in calycosin-dosed NPC cells and tumor-bearing nude mice. Conclusion: Altogether, these bioinformatic findings reveal optimal pharmacological targets and mechanisms of calycosin against NPC, following with representative identification of human and preclinical experiments. Notably, some of original biotargets may be potentially used to treat NPC.

scholarly journals Granulocyte aggregometry: a sensitive technique for the detection of C5a and complement activation

Blood ◽  
1980 ◽  
Vol 55 (6) ◽  
pp. 898-902 ◽  
Author(s):  
DE Hammerschmidt ◽  
TK Bowers ◽  
CJ Lammi-Keefe ◽  
HS Jacob ◽  
PR Craddock
Keyword(s):  
Lupus Erythematosus ◽  
Cytochalasin B ◽  
Normal Subjects ◽  
Standard Methods ◽  
Sensitive Technique ◽  
Fresh Serum ◽  
Induced Aggregation ◽  
Transfusion Reactions

Abstract We have previously shown that complement (C) activated plasma causes granulocyte (PMN) aggregation in vitro and that C5a is responsible. The C-induced aggregation of PMNs treated with cytochalasin-B (CB) is markedly enhanced and irreversible, and the magnitude of the response is proportional to the log (concentration of activated plasma), allowing use of this technique to detect C5a and hence C-activation. To compare the sensitivity of granulocyte aggregometry to that of more standard methods of detecting C-activation, we produced graded C- activation in vitro by treating fresh serum with varying amounts of zymosan. Aggregometry was the most sensitive index of C-activation, detecting C-activation, produced by 0.02 mg zymosan/ml of serum--1/10 that required to produce C-activation detectable by C3 immunoelectrophoresis (the next most sensitive technique). Granulocyte aggregometry may also be used to detect in vivo C-activation. We have found aggregating activity in plasmas from patients with systemic lupus erythematosus, immune vasculitis, transfusion reactions, and other conditions associated with in vivo C-activation, but not in the plasmas of normal subjects.

Sign in / Sign up

Export Citation Format

Share Document