Chemical Embryology

Needham, Joseph

doi:10.1146/annurev.bi.01.070132.002451

Cited by 33 publications

(41 citation statements)

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“…Since there is no sudden change at any one point, the gradual effect of maturing tissue may account for this, rather than other physiological changes which take place more suddenly in the embryo (16).…”

Section: Effect Of Age Of Embryomentioning

confidence: 99%

The Course of Experimental Infection of the Chick Embryo With the Virus of Equine Encephalomyelitis

Bang¹

1943

Journal of Experimental Medicine

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The titration curve for the virus of Eastern equine encephalomyelitis inoculated into the 10 day old chick embryo shows that the maximum increase in virus content continues until shortly before the generalized destruction of the embryo is apparent. This is followed by a stationary phase. Histological studies of infected embryos fail to demonstrate selective tissue destruction, and titrations show the virus to be distributed throughout the egg, although concentrated in the embryo. The chorioallantoic membrane gradually becomes increasingly resistant with age to both the Eastern and Western viruses. Increased resistance with age is also apparent in the hatched chick. These findings are based on the use of the chick embryo itself as the test animal to determine the 50 per cent mortality end-point. The limits of accuracy of this method are defined.

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Section: Effect Of Age Of Embryomentioning

confidence: 99%

The Course of Experimental Infection of the Chick Embryo With the Virus of Equine Encephalomyelitis

Bang¹

1943

Journal of Experimental Medicine

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“…These results and those with mud extracts may be linked with the need of the developing echinoderm egg and larva to absorb substances from the surrounding medium (Needham, 1931) and it may be necessary for some of these substances to be absorbed very soon after fertilization. The experiments do not indicate that there is anything in filtrates (which contained some natural sea water) from diatom or flagellate cultures, or from culture medium itself, which can supply those needs.…”

Section: Discussionmentioning

confidence: 96%

Biological Differences Between Sea Waters: Experiments in 1954 and 1955

Wilson

Armstrong

1958

J. Mar. Biol. Ass.

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331The experiments described and discussed below were made during the 1954 and 1955 breedings seasons of Echinus esculentus. They were a continuation of those made in previous years (Wilson, 1951;Wilson & Armstrong, 1952, 1954 and were designed to obtain more information concerning the factors responsible for biological differences between sea waters. In spite of the indefiniteness of many results it is considered desirable to publish them now because it does not seem likely that they can be supplemented in the near future, and because they do contain information which may influence further work in this field.We should again like to express our thanks to the Marine Station at Millport, especially to Mr E. Latham, for co-operating with us in the collection of water samples. THE EXPERIMENTSMethods did not differ in any material respect from those already described in our earlier papers, with the exception of the sea water extracts used in Expt. 8. In making these sea water was passed slowly through a Berkefeld candle and then through a column of active carbon (copper-free). The carbon was then washed with a little distilled water, dried at room temperature, and extracted with successive small portions of cold pyridine until no further coloured material was removed. The extracts were combined and evaporated in vacuo at room temperature; waxy brown solids were obtained which dispersed readily in water. A 'blank' extract was also made from the untreated carbon. 18'01. of E I water gave 0'0547 g of material which was dispersed in 18 mI. water. 18'51. of Clyde water gave 0'°441 g, which was dispersed in 18'5 m1. water. The blank extract was dispersed in 18 m1. water. For the experiments 8'0 mI. of these concentrates were added to 2 1. of artificial sea water.

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“…One definite conclusion certainly emerges, namely, that the early chick embryo possesses the machinery for protein breakdown, and its normal (and almost exclusive) use of carbohydrate is not due to the lack of this machinery. This is exactly the opposite of the state of affairs during the second week of development, when although ample stores of carbohydrate are still available in the egg (and may be artificially increased by injection) the increase of protein katabolism follows a regular and invariable course (Needham, 1926, a). It would seem that some as yet obscure necessity governs the succession of energy-sources, something other than the lack of the required machinery; something other than the availability of the raw materials.…”

Section: Discussionmentioning

confidence: 97%

“…Cases of this have been found by Dickens (1932), e.g., a fasting liver, which gave a respiratory quotient of 0 · 6 and from which keto-bodies were obtained when the contents of the manometer cups was subsequently distilled. It is unlikely to be due to a participation of fat katabolism, since it has been shown (Needham 1931(Needham , p. 1171) that desaturation can only take place at a much later stage of development. One definite conclusion certainly emerges, namely, that the early chick embryo possesses the machinery for protein breakdown, and its normal (and almost exclusive) use of carbohydrate is not due to the lack of this machinery.…”

Section: Discussionmentioning

confidence: 99%

A manometric analysis of the metabolism in avian ontogenesis―II. The effects of fluoride, Iodoacetate, and other reagents on the respiration of blastoderm, embryo, and yolk-sac

Needham

1932

Proc. R. Soc. Lond. B.

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The study of cell-respiration by means of agents with a known action upon some one part of the cellular mechanisms has in recent years been much pursued, and it has to some extent been possible to make a differential attack upon the various co-operating processes which are so efficiently integrated in the intact cell. These methods suffer, it is true, from the disadvantage that the addition of an ion such as fluoride to the cell-interior may not merely inhibit a certain reaction which normally goes on there, but may also bring into being a number of distinctively pathological reactions which have no place in the normal cell. It is not surprising, therefore, that the results of experiments on cell-respiration are difficult to interpret. But difficulties of interpretation are no ground for failing to make use of any methods. which are available, and the possibility of complicated secondary effects is, after all, common to all biological methods in which the normal course of events within the organism is interfered with. Up to the present time, the study of the effect of agents such as fluoride, cyanide, iodoacetic acid, triphenylmethane dyes, sulphides, pyrophosphates, etc., has been confined to the cells of adult tissues ( cf . Dixon, 1929; wurmser, 1930) or to bacteria ( e. g ., Haldane, Cook and Mapson, 1931). But it would obviously be of much interest to observe their effects upon cells of early embryonic stages for we might hope in this way to discover something of the way in which the chemical machinery of the cell is laid down. To what extent, for instance, do the cells of a somite in a two-day old chick embryo resemble adult muscle cells in their reactions to the glycolysis-inhibiting action of iodoacetic acid ? Moreover, a good deal of evidence exists that embryos in the earlier stages of development combust carbohydrate molecules exclusively, and that later on the combustion of protein and fat sets in. What will happen then, to the metabolism of embryonic cells in the carbohydrate stage if their glycolysing power is artificially inhibited? Is the power of deaminating and combusting amino-acids already present and not used, or has it not yet developed ? In the former case the respiratory quotient should betray a change over to protein combustion; in the latter case the cells should cease to respire altogether. It was to answer questions such as these that the work described in the present paper was undertaken.

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Chemical Embryology

Cited by 33 publications

References 0 publications

The Course of Experimental Infection of the Chick Embryo With the Virus of Equine Encephalomyelitis

The Course of Experimental Infection of the Chick Embryo With the Virus of Equine Encephalomyelitis

Biological Differences Between Sea Waters: Experiments in 1954 and 1955

A manometric analysis of the metabolism in avian ontogenesis―II. The effects of fluoride, Iodoacetate, and other reagents on the respiration of blastoderm, embryo, and yolk-sac

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