NEW ORAL LINGUIFORM PROJECTIONS AND THEIR ASSOCIATED NEURONS IN THE THIRD-STAGE INFECTIVE LARVA OF THE PARASITIC NEMATODE OESOPHAGOSTOMUM DENTATUM

2005 ◽  
Vol 91 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Fredrik Hoholm ◽  
Xiaodong Zhu ◽  
Francis T. Ashton ◽  
Andrea S. Freeman ◽  
Yuri Veklich ◽  
...  
Keyword(s):  
Parasitic Nematode ◽  
Infective Larva ◽  
The Third ◽  
Oesophagostomum Dentatum ◽  
Third Stage

The effect of catecholamines and catecholamine antagonists on the third larval moult of Dirofilaria immitis in vitro

1992 ◽  
Vol 66 (4) ◽  
pp. 273-278 ◽  
Author(s):  
E. V. Warbrick ◽  
S. A. Ward
Keyword(s):  
Dirofilaria Immitis ◽  
Parasitic Nematode ◽  
The Third ◽  
Adrenergic Antagonist ◽  
Third Stage ◽  
Larval Moult

ABSTRACTVarious catecholamines and catecholamine antagonists have been examined for their effects on the third larval moult of the parasitic nematode, Dirofilaria immitis, cultured in vitro. The non-selective α and β agonist, noradrenaline, and the β agonist, isoprenaline, had no effect on the timing of the third stage moult when used at a concentration of 10−5M. The α-adrenergic antagonist. phentolamine, resulted in worm mortality at 10−5M. At 10−7M, both phentolamine and the β-antagonist, propranolol caused a significant reduction in the numbers of larvae capable of completing the third stage moult. Idazoxan, an a2-antagonist, at 10−5M did not affect worm mortality but did completely prevent ecdysis. The potential of these compounds as possible filaricides is discussed.

Studies on the life-history of Bunostomum phlebotomum (Railliet, 1900), a hookworm parasite of cattle

Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent
Keyword(s):  
Infective Larva ◽  
Stage Larva ◽  
Fourth Stage ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
History Of ◽  
Time Required ◽  
Cutaneous Blood ◽  
Fourth Stage Larva

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.

scholarly journals Peculiarities of Embryonic and Post-Embryonic Development of Оesophagostomum dentatum (Nematoda, Strongylidae) Larvae Cultured in Vitro

2017 ◽  
Vol 51 (1) ◽  
pp. 67-72
Author(s):  
V. А. Yevstafieva ◽  
I. I. Panikar ◽  
V. V. Melnychuk ◽  
L. N. Korchan ◽  
N. A. Perederii
Keyword(s):  
Embryonic Development ◽  
Sus Scrofa ◽  
Infective Larva ◽  
Infective Stage ◽  
Optimum Temperature ◽  
Domestic Pig ◽  
The Third ◽  
Third Stage ◽  
Sus Scrofa Domesticus

Abstract Morphometric peculiarities of the development of Оesophagostomum dentatum Rudolphi, 1803 from egg to infective larva were studied under laboratory conditions at various temperatures. The determined optimum temperature for embryonic and post-embryonic development of О. dentatum larvae from domestic pig (Sus scrofa domesticus Linnaeus, 1758) is 22 °С. At this temperature, 81 % of larvae develop to the third stage (L3) on the 10th day. Temperatures of 24 °С and 20 °С are less favorable for the development of the nematode, at those temperatures only 67 and 63 % of larvae, respectively, reached infective stage by the 10th day of cultivation. Embryonic development of О. dentatum eggs is characterized by their lengthening (by 8.87-9.50 %, р < 0.01) and widening (by 6.77-9.35 %, р < 0.05-0.01), and post-embryonic larval development is associated with lengthening (by 4.59-17.33 %, р < 0.01-0.001).

The Occurrence of Haemonchus similis Travassos, 1914 in Cattle in Fiji

1963 ◽  
Vol 37 (3) ◽  
pp. 179-184 ◽  
Author(s):  
A. D. Donald
Keyword(s):  
Infective Larva ◽  
The Third ◽  
Third Stage ◽  
First Time

Haemonchus similis Travassos, 1914 is recorded from Fiji for the first time. The third stage infective larva of H. similis is briefly described. Attention is drawn to the similarity of this larva to that of H. contortus of sheep and some of the implications are discussed.

Penetration of mammalian skin by the infective larva ofNippostrongylus brasiliensis

Parasitology ◽  
1972 ◽  
Vol 65 (3) ◽  
pp. 499-505 ◽  
Author(s):  
D. L. Lee
Keyword(s):  
Thin Films ◽  
Infective Larva ◽  
Ionic Composition ◽  
Three Dimensional ◽  
Nippostrongylus Brasiliensis ◽  
Two Dimensional ◽  
Bathing Medium ◽  
The Third ◽  
Third Stage ◽  
Mammalian Skin

The behaviour of the third-stage larvae ofNippostrongylus brasiliensishas been studied on rat, mouse and human skin. Locomotion in thin films of moisture is by two-dimensional, undulatory propulsion on skin, and by three-dimensional, undulatory propulsion on hairs. In drops of water or in thick films of moisture locomotion is less efficient than in thin films. It is suggested that the thin film of moisture around larvae on the skin may become coated with a thin monolayer of lipid which could reduce evaporation from the surface of the nematode and from the film of moisture, thus extending the period before desiccation begins. Studies with the electron microscope have shown that the larvae move horizontally into the stratum corneum and later penetrate the epidermis and dermis by separating the constituent cells of these tissues. In the dermis there is dissolution of collagen around the larvae. It is suggested that this separation of cells and dissolution of collagen need not be brought about by enzyme action, as similar effects can be brought about by changes in pH or ionic composition of the bathing medium.

scholarly journals Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum

2008 ◽  
Vol 2 (6) ◽  
pp. e246 ◽  
Author(s):  
Cui-Qin Huang ◽  
Robin B. Gasser ◽  
Cinzia Cantacessi ◽  
Alasdair J. Nisbet ◽  
Weiwei Zhong ◽  
...  
Keyword(s):  
Parasitic Nematode ◽  
Ascaris Suum ◽  
Bioinformatic Analysis ◽  
Stage Larva ◽  
The Third ◽  
Third Stage

The Coherence of Mary Barton: Romance, Realism, and Utopia

2015 ◽  
Vol 5 (3) ◽  
pp. 185-200
Author(s):  
Robert Z. Birdwell
Keyword(s):  
Thomas Carlyle ◽  
The Novel ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Three Stages ◽  
Mode Of Production

Critics have argued that Elizabeth Gaskell's first novel, Mary Barton (1848), is split by a conflict between the modes of realism and romance. But the conflict does not render the novel incoherent, because Gaskell surpasses both modes through a utopian narrative that breaks with the conflict of form and gives coherence to the whole novel. Gaskell not only depicts what Thomas Carlyle called the ‘Condition of England’ in her work but also develops, through three stages, the utopia that will redeem this condition. The first stage is romantic nostalgia, a backward glance at Eden from the countryside surrounding Manchester. The second stage occurs in Manchester, as Gaskell mixes romance with a realistic mode, tracing a utopian drive toward death. The third stage is the utopian break with romantic and realistic accounts of the Condition of England and with the inadequate preceding conceptions of utopia. This third stage transforms narrative modes and figures a new mode of production.

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