scholarly journals Histochemical and radiographic investigations of Malathion-induced malformations in embryonic chick limbs

1972 ◽  
Vol 50 (3) ◽  
pp. 349-351 ◽  
Author(s):  
G. R. Gill ◽  
Q. N. LaHam
Keyword(s):  
Toluidine Blue ◽  
Ground Substance ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Chondroitin Sulfates

The organophosphate Malathion produces malformations in the limbs of chick embryos. Staining with buffered toluidine blue reveals abnormal areas in the cartilage characterized by hypertrophy of the chondroblasts, lack of ground substance, and weak (gamma) γ metachromasia. Radioautography with S35 shows little incorporation into the chondroitin sulfates of the cartilage ground substance.

Dexamethasone Effect on Embryonic Chick Respiratory Epithelium

1982 ◽  
Vol 40 ◽  
pp. 248-249
Author(s):  
M.R. Richter ◽  
R.V. Blystone
Keyword(s):  
Lung Development ◽  
Critical Role ◽  
Respiratory Epithelium ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
White Leghorn ◽  
Lung Maturation ◽  
Synthetic Analogs ◽  
Lung Physiology ◽  
Avian Lung

Dexamethasone and other synthetic analogs of corticosteroids have been employed clinically as enhancers of lung development. The mechanism(s) by which this steroid induction of later lung maturation operates is not clear. This study reports the effect on lung epithelia of dexamethasone administered at different intervals during development. White Leghorn chick embryos were used so as to remove possible maternal and placental influences on the exogenously applied steroid. Avian lung architecture does vary from mammals; however, respiratory surfactant produced by the lung epithelia serves an equally critical role in avian lung physiology.

scholarly journals Loss of potassium from embryonic chick hearts in potassium-free media with and without calcium

1938 ◽  
Vol 124 (837) ◽  
pp. 446-450
Keyword(s):  
Phosphate Buffer ◽  
Direct Evidence ◽  
Watch Glass ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Intercellular Spaces ◽  
Experimental Solution ◽  
Free Media ◽  
And Control ◽  
Day By Day

Experiments already described (Murray 1938) led to the inference that the cells of the chick embryonic heart lose potassium in potassium-free media. The experiments here described provide direct evidence of this. The hearts were dissected out of 2 ½-3 day chick embryos and placed in the solution PC (Table I) until they had started to beat. They were then thoroughly washed, and were allowed to lie for 5 min. (2 min. in Exp. 1) in the last wash. This last wash is called control A. The solutions used for washing were from the same flasks as the experimental solution. After their passage through control A the hearts were transferred to 2 c.c. of the experimental solution in a Jena watch-glass. After various times in this the hearts were discarded and both the experimental solution and control A were collected. If the experiment extended over more than 1 day the experimental solution and control A were used over again day by day until all the hearts in the experiment had passed through them. The use of control A was necessary for two reasons: ( a ) to show that potassium was not still being washed out of the intercellular spaces at the end of washing ( b ) in experiments lasting over several days the washing solution was fresh each day, but the experimental solution was of course not changed. Hence any small amount of potassium being carried over from the last wash would accumulate in the experimental solution because of the daily increment and might seriously affect the result; but by leaving the hearts for several minutes in the last wash (control A) and by not changing it for fresh on successive days, any such increase would be detected in that solution. In addition to control A, a daily sample (control B) was taken from the same flasks as the solutions used for washing. Details of the solutions are given in Table I ; a phosphate buffer was always used.

EVIDENCE FOR THE EXISTENCE OF FOUR TYPES OF RIBONUCLEOPROTEIN IN THE NERVE CELLS OF THE CEREBELLUM IN THE ADULT CAT

1965 ◽  
Vol 43 (2) ◽  
pp. 357-367 ◽  
Author(s):  
L. A. Chouinard
Keyword(s):  
Purkinje Cells ◽  
Toluidine Blue ◽  
Ganglion Cells ◽  
Observational Evidence ◽  
Fastigial Nucleus ◽  
Staining Procedure ◽  
Ground Substance ◽  
Ribonucleic Acids ◽  
Nucleolar Apparatus ◽  
Adult Cat

In Helly-fixed cerebella, the toluidine blue – molybdate staining procedure reveals the existence of four distinct types of ribonucleoprotein in both the Purkinje cells of the vermian zone and the multipolar ganglion cells of the fastigial nucleus. These four types of ribonucleoprotein are found in, respectively, the ground substance (nucleolar matrix) of the nucleolus, the intranucleolar vacuoles (nucleolini), the intranuclear paranucleolar masses, and the cytoplasmic Nissl bodies. The relevant observational evidence suggests that the two organelles of the nucleolar apparatus, that is, the nucleolus and paranucleolar masses together with their associated chromocenters, are concerned with distinct synthetic activities with regard to the elaboration of neuronal ribonucleic acids or ribonucleoproteins. The significance of the above findings is discussed in the light of current concepts pertaining to cellular ribonucleoprotein metabolism.

The genesis of membrane bone in the embryonic chick maxilla: epithelial-mesenchymal tissue recombination studies

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 269-281
Author(s):  
Mary S. Tyler ◽  
David P. McCobb
Keyword(s):  
Bone Formation ◽  
Hind Limb ◽  
Bone Grafts ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Limb Buds ◽  
Mesenchymal Tissue ◽  
Membrane Bone ◽  
Tissue Recombination

In the present study, the question of whether a relatively non-specific epithelial requirement exists for membrane bone formation within the maxillary mesenchyme was investigated. Organ rudiments from embryonic chicks of three to five days of incubation (HH 18–25) were enzymatically separated into the epithelial and mesenchymal components. Maxillarymesenchyme (from embryos HH 18–19) which in the absence of epithelium will not form bone was recombined with epithelium from maxillae of similarly aged embryos (homotypichomochronic recombination) and of older embryos (HH 25) (homotypic-heterochronicrecombination). Heterotypic recombinations were made between maxillary mesenchyme (HH 18–19) and the epithelium from wing and hind-limb buds (HH 19–22). Recombinants were grown as grafts on thechorioallantoic membranes of host chick embryos. Grafts of intact maxillae, isolated maxillary mesenchyme, and isolated epithelia from the maxilla, wing-, and hind-limb buds weregrown as controls. The histodifferentiation of grafted intact maxillae was similar to that in vivo; both cartilage and membrane bone differentiated within the mesenchyme. Grafts of maxillary mesenchyme (from embryos HH 18–19) grown in the absence of epithelium formed cartilage but did not form membrane bone. Grafts of maxillary mesenchyme (from embryos HH 18–19) recombined with epithelium in homotypichomochronic, homotypic-heterochronic, and heterotypic tissue combinations formed membrane bone in addition to cartilage. These results indicate that maxillary mesenchyme requires the presence of epithelium to promote osteogenesis and that this epithelial requirement is relatively non-specific in terms of type and age of epithelium.

scholarly journals THE FINE STRUCTURE OF EMBRYONIC CHICK SKELETAL MUSCLE CELLS DIFFERENTIATED IN VITRO

1967 ◽  
Vol 35 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Y. Shimada ◽  
D. A. Fischman ◽  
A. A. Moscona
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Fine Structure ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Developing Muscle

Dissociated myoblasts from 12-day chick embryos were cultured in monolayer, and the differentiation of skeletal muscle cells was studied by electron microscopy. The results have revealed a striking ultrastructural similarity between the in vivo and the in vitro developing muscle, particularly with respect to the myofibrils and sarcoplasmic reticulum. This study demonstrates that all the characteristic organelles of mature skeletal muscle can develop in vitro in the absence of nerves.

Temperature and Heart Rate in Chick Embryos

1930 ◽  
Vol 7 (2) ◽  
pp. 143-153
Author(s):  
E. R. PARPART ◽  
OTTO GLASER
Keyword(s):  
Heart Rate ◽  
Critical Points ◽  
Heart Rhythm ◽  
Chemical Mechanism ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Temperature Characteristics ◽  
Physical Chemical ◽  
Chick Heart ◽  
Embryonic Chick Heart

In accordance with expectation, the embryonic chick heart exposes recurrently temperature characteristics of the orders 8,200, 14,200, 16,400, 18,300, 20,500 and 25,200. These are found in both myogenic and neurogenic hearts but not with the same frequencies. These two periods of development also differ in the localisation of critical points. So far µ = 8,200, 14,200 and 18,300 have been exposed in embryos only by Fundulus; the remaining three orders however are recurrent also in the embryogeny of Limulus. Two orders not included in this hst (5,000 and 11,000) are rare, yet, even so, not restricted to any one of the three forms. These facts, together with their implications, suggest for heart rhythm in Limulus, Fundulus and the Chick, an underlying physical-chemical mechanism in structure identical for all three types of heart at all stages of development, and differing in neurogenic stages only by a revision of the myogenic time relations.

The ubiquitous occurrence of chondroitin sulfates in chick embryos

1975 ◽  
Vol 194 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Paulo A. Abrahamsohn ◽  
James W. Lash ◽  
Robert A. Kosher ◽  
Ronald R. Minor
Keyword(s):  
Chick Embryos ◽  
Chondroitin Sulfates

scholarly journals SECRETION OF α-AMYLASE BY THE EMBRYONIC CHICK PANCREAS IN VITRO

1966 ◽  
Vol 29 (2) ◽  
pp. 287-292 ◽  
Author(s):  
R. G. Kulka ◽  
U. Yalovsky
Keyword(s):  
Digestive Enzymes ◽  
Morphological Changes ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Cholinergic Drugs ◽  
Developmental Age

Pancreases taken from chick embryos secrete amylase in vitro when stimulated by cholinergic drugs. Rates of secretion increase with developmental age. The pancreas isolated together with the duodenal loop from the 8 day embryo is already capable of secretion in vitro. It is therefore concluded that the pancreas acquires the ability to secrete digestive enzymes more than 10 days before the beginning of the prominent biochemical and morphological changes associated with the maturation of the gland.

Experimental Neoplastic Formation in Embryonic Chick Brains

Development ◽  
1960 ◽  
Vol 8 (1) ◽  
pp. 20-23
Author(s):  
Bengt Källén
Keyword(s):  
Cell Differentiation ◽  
Thin Layer ◽  
Neural Tube ◽  
Present Author ◽  
Chick Embryos ◽  
Post Mortem ◽  
Embryonic Chick ◽  
The Brain ◽  
Excessive Proliferation ◽  
Rostral Part

In mammalian teratology, a malformation consisting of ‘overgrowth’ of the neural tube has been described by, among others, Patten (1952, 1957) and Ariëns Kappers (1956, 1957). Sjodin (1957) thought it to be a post-mortem effect and not a true malformation. The present author (1955) demonstrated that a similar malformation could be produced in the rostral part of the brain of chick embryos by operations at somite stages on the rostral end of the rhombencephalon which damaged underlying notochordal structures. Bergquist (1959 a, b) has discussed this problem further. The overgrowth is made up of an excessive proliferation in the neural epithelium with a reduced cell differentiation, giving rise to only a thin layer of migrated cells but to a marked development of neural epithelium in 4- to 5-day embryos. The vesicles of the hemispheres and mesencephalon are strongly folded, and Bergquist (1959c) has produced evidence that the folding is due to the accumulation of mitoses along the ventricular lining of the vesicles.

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