The Differential Growth Response of Embryonic Chick Limb-bone Rudiments to Triiodothyronine in vitro

Development ◽  
1961 ◽  
Vol 9 (1) ◽  
pp. 42-51
Author(s):  
Kirstie Lawson
Keyword(s):  
Vitamin A ◽  
Thyroid Hormones ◽  
Growth Response ◽  
Nutritional Deficiencies ◽  
Embryonic Chick ◽  
Differential Growth ◽  
Relative Growth ◽  
Limb Bone ◽  
Leg Bones

The proportionate development of the embryonic chick skeleton can be influenced experimentally by a variety of factors such as nutritional deficiencies (Byerly, Titus, Ellis, & Landauer, 1935; Landauer, 1936; Romanoff & Bauernfeind, 1942; Couch, Cravens, Elvehjem, & Halpin, 1948), teratogens (Ancel & Lallemand, 1942; Zwilling & de Bell, 1950; Landauer, 1952, 1953a, 1954) and excess hormones (Willier, 1924; Landauer & Bliss, 1946; Duraiswami, 1950). The leg bones are generally more severely affected than the wing bones, but a comparison of the action of several teratogens on the character of the malformations and on the relative growth of the leg bones indicated that the response of individual bones varies with the different agents (Landauer & Rhodes, 1952; Landauer, 1953 a, b, 1954). Cartilaginous limb-bone rudiments also respond differentially when they are isolated from the embryo and exposed in culture to various compounds, such as insulin (Chen, 1954), vitamin A, and the thyroid hormones (Fell & Mellanby, 1955, 1956).

The Differential Growth-response of Embryonic Chick Limb-bone Rudiments to Triiodothyronine in vitro

Development ◽  
1961 ◽  
Vol 9 (3) ◽  
pp. 534-555
Author(s):  
Kirstie Lawson
Keyword(s):  
Tissue Culture ◽  
Growth Response ◽  
Differential Response ◽  
Long Bone ◽  
Long Bones ◽  
Embryonic Chick ◽  
Differential Growth ◽  
Limb Bone ◽  
Stage Of Development

The maturation of the cartilage of embryonic chick long-bone rudiments growing in tissue culture is accelerated by addition of the thyroid hormones, thyroxine and triiodothyronine, but the growth in length of different long bones is not uniformly affected (Fell & Mellanby, 1955, 1956). Thus the growth of the hormone-treated tibia is less than that of a normal tibia, while the effect of thyroid hormone on the radius is to increase its growth. This differential response is not determined either by the stage of development at which the limb-bone rudiments are exposed to hormone, or by the size of the explant (Lawson, 1961). Investigations to determine whether the differential response of limb-bone rudiments to triiodothyronine (T3) is due to differences in the growth rates of different bones are described in this paper. The work was divided into three parts.

The Differential Growth-Response of Embryonic Chick Limb-Bone Rudiments to Triiodothyronine in vitro. III. Hormone Concentration.

Development ◽  
1963 ◽  
Vol 11 (2) ◽  
pp. 383-398
Author(s):  
Kirstie Lawson
Keyword(s):  
Growth Rate ◽  
Growth Response ◽  
Specific Growth ◽  
Differential Growth ◽  
Limb Bone ◽  
Limb Bones ◽  
High Specific Growth Rate ◽  
Specific Growth Rates

Rudiments of each of the limb bones from the same chick embryo differ in their growth response to thyroid hormones in vitro (Fell & Mellanby, 1955, 1956). These variations in response to triiodothyronine (T3) are not determined by differences in maturity or size of the rudiments (Lawson, 1961a), but are associated with differences in their normal specific growth rates in vivo; T3 retards the growth of rudiments which normally have a high specific growth rate and stimulates the growth of those which grow slowly in vivo. However, when the growth rate of the limb-bone rudiments is altered in vitro by varying the composition of the medium or the temperature, the characteristic responses of different rudiments to T3 are not greatly altered (Lawson, 1961b). For example, the effect of T3 on the radius, a slowly growing rudiment, is to stimulate growth, whereas the same amount of T3 retards the growth rate of the third metatarsus which is normally a fast growing bone.

scholarly journals Induction of biotransformation enzymes by polyhalogenated aromatic hydrocarbons (PHAHs):potential impact on animal physiology and health

1999 ◽  
pp. 209-221
Author(s):  
Abraham Brouwer
Keyword(s):  
Thyroid Hormone ◽  
Vitamin A ◽  
Thyroid Hormones ◽  
Aromatic Hydrocarbons ◽  
Recent Observation ◽  
Biological Activities ◽  
Phenolic Metabolites ◽  
Biotransformation Enzymes ◽  
Polyhalogenated Aromatic Hydrocarbons

Biotransformation and its role in the elimination of polyhalogenated aromatic hydrocarbons (PHAHs) has been the subject of many studies from the late seventies onwards. The notion of specific, high affinity interactions of phenolic PHAH metabolites with the plasma transport proteins of thyroid hormone and vitamin A, both in vitro and in vivo, stimulated further research into the possible role of biotransformation in the toxicity of certain PHAHs such as PCBs. Currently, phenolic metabolites of PCBs and related compounds have been identified as major metabolites in blood plasma of e.g. grey seals (Halichoerus grypus) and humans with background environmental exposure to these chemicals. The concentrations of the hydroxy-PCBs were in the same range as the most persistent parent congeners, such as PCB 153, 138 and 180. These phenolic metabolites were found to possess a specific range of biological activities, which differed from the parent compounds. Another potential adverse effect associated with persistent induction of biotransformation enzymes, like UDP-glucuronyl transferases (UGTs) by PHAHs, is a long-term enhanced elimination of several important endogenous ligands such as vitamin A and thyroid hormones. Reduced levels of vitamin A and thyroid hormones have been reported in most experimental animal and wildlife species exposed to PHAHs. The recent observation of the accumulation of high levels of phenolic PCB metabolites in blood and brain of late gestational rat foetuses, in parallel with reductions in both vitamin A and thyroid hormone levels, suggests that these metabolites may play an important role in the observed developmental toxicity of PHAHs

scholarly journals How the embryonic chick brain twists

2016 ◽  
Vol 13 (124) ◽  
pp. 20160395 ◽  
Author(s):  
Zi Chen ◽  
Qiaohang Guo ◽  
Eric Dai ◽  
Nickolas Forsch ◽  
Larry A. Taber
Keyword(s):  
Surface Tension ◽  
Theoretical Analysis ◽  
Vitelline Membrane ◽  
Necessary Condition ◽  
Embryonic Brain ◽  
Embryonic Chick ◽  
Chick Brain ◽  
Differential Growth ◽  
Left Right Asymmetry

During early development, the tubular embryonic chick brain undergoes a combination of progressive ventral bending and rightward torsion, one of the earliest organ-level left–right asymmetry events in development. Existing evidence suggests that bending is caused by differential growth, but the mechanism for the predominantly rightward torsion of the embryonic brain tube remains poorly understood. Here, we show through a combination of in vitro experiments, a physical model of the embryonic morphology and mechanics analysis that the vitelline membrane (VM) exerts an external load on the brain that drives torsion. Our theoretical analysis showed that the force is of the order of 10 micronewtons. We also designed an experiment to use fluid surface tension to replace the mechanical role of the VM, and the estimated magnitude of the force owing to surface tension was shown to be consistent with the above theoretical analysis. We further discovered that the asymmetry of the looping heart determines the chirality of the twisted brain via physical mechanisms, demonstrating the mechanical transfer of left–right asymmetry between organs. Our experiments also implied that brain flexure is a necessary condition for torsion. Our work clarifies the mechanical origin of torsion and the development of left–right asymmetry in the early embryonic brain.

In vitro studies of limb regeneration in adult Diemictylus viridescens: Neural dependence of blastema cells for growth and differentiation

Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 813-829
Author(s):  
Morton Globus ◽  
Richard A. Liversage
Keyword(s):  
Growth Response ◽  
Close Association ◽  
Limb Regeneration ◽  
Normal Growth ◽  
Spinal Ganglia ◽  
Chemical Factor ◽  
Differential Growth ◽  
Physical Presence ◽  
Active Proliferation

Explants of 99 adult newt forelimb blastemata (21- to 24-day regenerates) were cultured, with and without implanted dorsal root ganglia, in modified Parker's medium (CMRL-1415) for periods of 72–144 h. Growth and differentiation of the cultured blastemata were compared with ganglionated and non-ganglionated controls fixed at the start of the culture period. The results of these experiments establish that implanted spinal ganglia are able to sustain growth and differentiation of forelimb blastemata in vitro: active proliferation amongst the blastema cells was found to be correlated with the presence of an implanted ganglion. In addition, the blastema cells exhibited a differential growth response which was most pronounced when the ganglion was eccentrically implanted 2–3 days before explantation of the limb regenerate. These results suggest that a causal relationship exists between the position of the implanted ganglion and the localization of growth within the blastema. The nerve influence, believed to be mediated by a chemical factor(s), was localized in the region of the implanted neurons, indicating that a close association between the nerves and the responding blastema cells is essential for normal growth. The importance of the physical presence of nerves for the cultivation of blastemata in vitro is emphasized.

Growth Response of Wheat (Triticum aestivum) Callus to Imazapyr and in Vitro Selection for Resistance

Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 174-179 ◽  
Author(s):  
David C. Heering ◽  
Arron C. Guenzi ◽  
Thomas F. Peeper ◽  
P. L. Claypool
Keyword(s):  
Growth Response ◽  
In Vitro Selection ◽  
Prediction Interval ◽  
Isoleucine Leucine ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Selection For ◽  
Wheat Callus ◽  
Percent Growth Inhibition

Intact wheat plants and wheat calli responded similarly to varying concentrations of imazapyr. Fifty percent growth inhibition of wheat callus occurred with 0.05 μM imazapyr after 70 d. As imazapyr concentration increased from 0 to 10 μM, the free isoleucine, leucine, and valine decreased from 160 to 35, 260 to 49, and 310 to 59 pmol mg−1, respectively. Resistant calli, which had relative growth rates exceeding a calculated upper prediction interval, were obtained by in vitro selection at 2 and 5 μM imazapyr. Resistant calli growing on 2 μM imazapyr had free isoleucine, leucine, and valine concentrations intermediate to the control and susceptible callus.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

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