Action of heart and liver RNA on the differentiation of segments of chick blastoderms

Development ◽  
1965 ◽  
Vol 13 (1) ◽  
pp. 119-128
Author(s):  
Joseph Butros
Keyword(s):  
Chick Embryo ◽  
Present Author ◽  
Posterior Segment ◽  
Nodal Explants ◽  
Neural Tubes ◽  
The Subject

The posterior segment isolated from definitive streak or head process blastoderms by a transverse cut 0·5–0·2 mm. posterior to Hensen's node seems to be a suitable experimental object for the study of differentiation. Its limited prospective significance and potency in chorioallantoic transplantation or in vitro compared with the versatile node has been the subject of several studies (Hunt, 1931; Willier & Rawles, 1931; Rawles, 1936; Rudnick, 1938a, b; Waddington 1933; Spratt, 1952). The present author has shown that rooster testis DNA and 5-day chick embryo DNA (0·25–0·50 mg./ml.) induce neural tubes and somitelike aggregations of the mesoderm in post-nodal explants cultured on albuminagar (Butros, 1960). When axial structures were grafted on the explants, the latter were induced to develop nephrotomes, ducts, neural folds and notochords (Butros, 1962). Improved procedures for culturing post-nodal explants, which circumvent the tendency of these pieces to form hollow vesicles, were reported recently (Butros, 1963a).

Reconstitutive ability of axial tissue in early rat embryos after operations and culture in vitro

Development ◽  
1975 ◽  
Vol 33 (1) ◽  
pp. 217-226
Author(s):  
E. M. Deuchar
Keyword(s):  
Close Contact ◽  
Axial Rotation ◽  
Rat Embryos ◽  
Histological Studies ◽  
Avian Embryos ◽  
Neural Tubes ◽  
The Subject ◽  
Neurula Stage ◽  
Made In

Longitudinal incisions have been made in the axis of 10-day-old rat embryos (post-neurula stage with 5–10 pairs of somites) at mid-trunk levels, dividing the axis into right and left halves. The embryos have then been cultured in vitro by New's method and their ability to reconstitute tissues in each half has been studied. After 20 h culture at 37 °C, there was no longer any external sign of the division of the axis. Histological studies showed that in nearly all cases, however, the neural tube was duplicated in the operated region. The two neural tubes lay in close contact in the midline, and ventral to them the gut was single. Apart from four cases in which the gut roof was slightly broadened and forked, all other tissues were normal. The reconstitutive ability of the neural and gut tissue has been compared with that of amphibian and avian embryos, as observed in ‘twinning’ experiments by other workers. The apparent delay in axial rotation in the operated rat embryos, as compared with controls, is attributed to the inability of the two separated halves of the somite series to co-ordinate their contractions. Further details of the rotation process in operated embryos will be the subject of a future study.

Relationship between ambient temperature and acetylating capacity of human blood

1963 ◽  
Vol 18 (5) ◽  
pp. 955-958 ◽  
Author(s):  
S. H. Blondheim ◽  
Gabriel Neumann ◽  
Edna Kott ◽  
Zena Ben-Ishai
Keyword(s):  
Ambient Temperature ◽  
Human Blood ◽  
Aromatic Amines ◽  
September 11 ◽  
Aminobenzoic Acid ◽  
Heat Acclimatization ◽  
The Subject

The ability of human blood to acetylate p-aminobenzoic acid, determined in vitro, varied directly with the ambient temperature to which the subject was exposed before the blood was drawn. This was demonstrated by 135 determinations of the acetylating ability of the blood of 49 subjects performed over a period of 3 years, and also in acute experiments in which subjects were exposed to 6 and 37 C for up to 2 hr. Variations in the acetylating ability of blood may reflect the activity of metabolic mechanisms involved in thermal homeostasis. aromatic amines; p-aminobenzoic acid; cold; heat acclimatization; (blood) enzymes; weather; environment Submitted on September 11, 1962

scholarly journals In vitro dissolution testing models of ocular implants for posterior segment drug delivery

2021 ◽  
Author(s):  
Muhammad Faris Adrianto ◽  
Febri Annuryanti ◽  
Clive G. Wilson ◽  
Ravi Sheshala ◽  
Raghu Raj Singh Thakur
Keyword(s):  
Drug Release ◽  
Posterior Segment ◽  
In Vitro Dissolution ◽  
Prolonged Treatment ◽  
Term Therapy ◽  
In Vitro Test ◽  
Dissolution Testing ◽  
Vitro Test ◽  
Ocular Implants

AbstractThe delivery of drugs to the posterior segment of the eye remains a tremendously difficult task. Prolonged treatment in conventional intravitreal therapy requires injections that are administered frequently due to the rapid clearance of the drug molecules. As an alternative, intraocular implants can offer drug release for long-term therapy. However, one of the several challenges in developing intraocular implants is selecting an appropriate in vitro dissolution testing model. In order to determine the efficacy of ocular implants in drug release, multiple in vitro test models were emerging. While these in vitro models may be used to analyse drug release profiles, the findings may not predict in vivo retinal drug exposure as this is influenced by metabolic and physiological factors. This review considers various types of in vitro test methods used to test drug release of ocular implants. Importantly, it discusses the challenges and factors that must be considered in the development and testing of the implants in an in vitro setup. Graphical abstract

scholarly journals Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1024
Author(s):  
Sebastien Dupont ◽  
Paul Fleurat-Lessard ◽  
Richtier Gonçalves Cruz ◽  
Céline Lafarge ◽  
Cédric Grangeteau ◽  
...  
Keyword(s):  
Computational Study ◽  
Antioxidant Properties ◽  
Beneficial Effects ◽  
Tert Butyl Hydroperoxide ◽  
Resistance To Oxidation ◽  
Specific Accumulation ◽  
The Subject

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.

A STUDY OF THE INHIBITORY EFFECTS OF CHICK WHOLE EYE EXTRACT ON THE DEVELOPMENT OF THE LENS OF THE CHICK EMBRYO IN VITRO

1966 ◽  
Vol 44 (4) ◽  
pp. 661-676 ◽  
Author(s):  
Robert P. Thompson
Keyword(s):  
Chick Embryo ◽  
Nutrient Medium ◽  
Inhibitory Effect ◽  
Reactive System ◽  
Vesicle Formation ◽  
Inhibitory Effects ◽  
Muscle Extract ◽  
Lens Vesicle ◽  
And Control

To demonstrate the phenomenon of homologous inhibition by clearly interpretable results in a readily reactive system, experiments were carried out to study the effect of chick whole eye extract on the development of the vesicular lens of the chick embryo in vitro. The heads of embryos of 11 through 13 somites were explanted onto nutrient medium diluted with varying amounts of the extract, and cultured for 30 hours. A total of 35 embryos exposed to concentrations of 1:1, 1:2, and 1:4 (extract to medium) showed complete inhibition of lens vesicle formation. Of a total of 53 embryos on concentrations of 1:8, 1:16, 1:32, and 1:64, more than 50% showed inhibition of vesicle formation. The inhibitory effect disappeared at a concentration of 1:128. Control material exposed to some equivalent concentrations of nutrient medium – saline mixtures showed inhibition of vesicle formation in only 15% of 33 embryos. Of a total of 27 control embryos exposed to ventricular muscle extract, approximately one-third showed inhibition of vesicle formation at concentrations of 1:8 and 1:16, with the inhibitory effect disappearing at 1:32. The implications of this result are discussed. Other factors and control experiments are described and their value is assessed.

A Culture Technique Using Marine Fish Kidney to Obtain Chromosomes

1979 ◽  
Vol 36 (4) ◽  
pp. 458-461 ◽  
Author(s):  
Eun Ho Park ◽  
Sang Dai Park
Keyword(s):  
Chick Embryo ◽  
Marine Fish ◽  
Culture Technique ◽  
Kidney Cells ◽  
High Concentration ◽  
Embryo Extract ◽  
Key Words Kidney ◽  
Chick Embryo Extract ◽  
Conger Eel

A relatively simple and reliable in vitro method for marine fish chromosome study was developed. The addition of 10% chick embryo extract to serum-supplemented Eagle's minimum essential medium with high concentration of NaCl resulted in marked growth of kidney cells in the marine conger eel (Astroconger myriaster) after activation by phytohemagglutinin (PHA). Culture medium without chick embryo extract or PHA and/or with normal concentration of NaCl did not induce substantial growth. In contrast to reports by others, humidified culture was not required for excellent cell growth of these teleost kidney cells. Numerous metaphases unmarred by overlapping chromosomes were recovered and excellent karyograms were available for detailed karyotype analysis. Key words: kidney, culture, marine fish, chromosome

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