Structure and composition of the metacercarial cyst wall of Sphaeridiotrema globulus (Trematoda)

1986 ◽  
Vol 16 (6) ◽  
pp. 647-653 ◽  
Author(s):  
Jane E. Huffman
Keyword(s):  
Cyst Wall ◽  
Metacercarial Cyst

Histochemical characteristics of the metacercarial cyst wall of Gynaecotyla adunca

1995 ◽  
Vol 69 (3) ◽  
pp. 223-228
Author(s):  
J. Lee ◽  
M.A. Medlin ◽  
S.T. Dunn
Keyword(s):  
Outer Layer ◽  
Cyst Wall ◽  
Light Microscope ◽  
Structural Modification ◽  
Microscope Level ◽  
Histochemical Analysis ◽  
Light Microscope Level ◽  
Metacercarial Cyst

AbstractThe cyst wall of the metacercaria of Gynaecotyla adunca (Microphallidae: Digenea) was subjected to comprehensive histochemical analysis. At the light microscope level, a uniformly thick, bipartite cyst wall, probably wholly of parasite origin, was evident. Structural modification of the cyst wall to provide an escape aperture was not apparent. The thicker, inner layer was comprised of phospholipid and glyco- and/or mucoproteins, possibly similar in structure to collagen. The outer layer was highly proteinaceous and contained additional amounts of acidic and neutral mucosubstances. The results are discussed in the context of previous observations regarding the excystment requirements of this microphallid species.

Evidence for the presence of quinone methide isomerase in the metacercarial cyst of Microphallus sp. (Trematoda: Microphallidae)

Parasitology ◽  
1991 ◽  
Vol 103 (2) ◽  
pp. 299-303
Author(s):  
K. Nellaiappan ◽  
R. Ramakrishnan ◽  
M. Jameela Banu
Keyword(s):  
Cyst Wall ◽  
Quinone Methide ◽  
Metacercarial Cyst ◽  
White Colour

The white colour of the cyst wall of the metacercaria of Microphallus sp., even in the presence of dihydroxy phenol and phenoloxidase, is due to proteins generated through a possible quinone methide interaction. The quinone methide isomerase converts the phenoloxidase mediated quinone into β-hydroxy catechol. Formation of catechol from quinone by cyst extracts was observed spectrophotometrically and chromatographically. This enzyme is involved in detoxification of excess quinone and β-sclerotization of the cyst wall.

Fine Structure of Posthodiplostomum Minimum Metacercarial Cyst Wall

1973 ◽  
Vol 31 ◽  
pp. 490-491
Author(s):  
C. W. Mitchell
Keyword(s):  
Cyst Wall ◽  
Outer Wall ◽  
Digenetic Trematode ◽  
Ultrastructural Organization ◽  
Fresh Water Fish ◽  
Intermediate Hosts ◽  
Metacercarial Cyst ◽  
Posthodiplostomum Minimum ◽  
Water Fish ◽  
Host Origin

The metacercaria of the digenetic trematode Posthodiplostomum minimum inhabit the major visceral organs, e.g. liver, kidney or heart, of numerous species of fresh-water fish as second intermediate hosts. These larval trematodes establish a thin cyst wall which is composed of a cellular, outer wall of host origin and an inner, acellular layer of parasitic origin. This report describes some preliminary observations on the ultrastructural organization of the metacercarial cyst wall found within naturally infected sunfish liver.These observations represent the first strigeid cyst studied by electron microscopy. However, cyst structure resembled others encysted within tissues of an intermediate host. A primary wall, apparently secreted by the parasite, prevents host destruction of the metacercaria.

Fine structure and permeability of the metacercarial cyst wall of Clinostomum marginatum (Digenea)

1988 ◽  
Vol 74 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Omer R. Larson ◽  
Gary L. Uglem ◽  
Kook J. Lee
Keyword(s):  
Fine Structure ◽  
Cyst Wall ◽  
Metacercarial Cyst

The formation, structure, and histochemistry of the metacercarial cyst of Philophthalmus gralli Mathis & Léger

Parasitology ◽  
1968 ◽  
Vol 58 (3) ◽  
pp. 605-618 ◽  
Author(s):  
Amar S. Thakur ◽  
Thomas C. Cheng
Keyword(s):  
Amino Acid ◽  
Chemical Composition ◽  
Cyst Wall ◽  
Outer Wall ◽  
Cyst Formation ◽  
American Cancer Society ◽  
Cancer Society ◽  
Gland Cells ◽  
Metacercarial Cyst ◽  
Amino Acid Contents

The presence of three types of cystogenous gland cells, designated as protein, mucopolysaccharide, and mucoprotein cells, in P. gralli cercariae has been demonstrated.The protein cells are PAS-negative but positive for tyrosine-, histidine-, and arginine-containing proteins. No tryptophane is detectable in this type of cell. The mucopolysaccharide cells are positive for acid mucopolysaccharides and are gamma-metachromatic. The mucoprotein cells are PAS-positive and diastaseresistant.The mechanism of metacercarial cyst formation is described. The fully formed cyst consists of three walls designated inner, middle and outer walls. The outer wall is subdivided into a basal and a peripheral layer.Histochemical studies on the cyst walls have shown that the outer and middle walls are PAS-negative but the inner wall is PAS-positive and diastase-resistant. All the walls include proteins but differ in their amino acid contents.By comparing the chemical composition of the cyst walls with that of the three types of cystogenous gland cells, it is evident that each cyst wall is formed from the secretions of two or more types of cells. The outer and middle walls appear to be formed from the secretions of both protein and mucopolysaccharide cells, and the inner wall from protein, mucopolysaccharide, and mucoprotein cells.This research was supported in part by a grant from the American Cancer Society.

Functional morphology of the metacercarial cyst of Bucephaloides gracilescens (Trematoda: Bucephalidae)

Parasitology ◽  
1982 ◽  
Vol 85 (1) ◽  
pp. 45-52 ◽  
Author(s):  
D. W. Halton ◽  
B. R. Johnston
Keyword(s):  
Functional Morphology ◽  
Cyst Wall ◽  
Intercellular Space ◽  
Granular Layer ◽  
Host Cells ◽  
Cranial Cavity ◽  
Collagen Fibres ◽  
Pepsin Digestion ◽  
Metacercarial Cyst

SUMMARYThe metacercarial cyst wall of Bucephaloides gracilescens is bilayered. It comprises an inner granular layer of pepsin-resistant carbohydrate and protein material secreted by the parasite, and an outer fibrous and cellular capsule susceptible to pepsin digestion and elaborated by the host. The capsule of cysts from the orbits and nasal regions of the whiting host are substantially thicker than those from the cranial cavity. Cells in the outer portion of the capsule resemble fibrocytes engaged in the synthesis and secretion of collagen; collagen fibres form a loose meshwork in the intercellular space. The cells incorporated [3H]proline in vitro, but not [3H]tyrosine. The cells of the inner portion of the capsule are closely packed and possess pyknotic nuclei; desmosomes and cytofilaments are numerous and probably impart strength and elasticity, respectively, to the cyst wall. Host cells are necrotic at the interface with the inner cyst wall, possibly due to compression or isolation from oxygen and nutrients. Differences in the levels of incorporation of trace-labelled substrates by encysted metacercariae were related to the site of infection and to the thickness and permeability of the cyst wall.

An in vitro study of the forcible ejection of the metacercaria of the strigeid digenean Apatemon (Australapatemon) minor Yamaguti, 1933 by rapid inward expansion of the cyst wall

1989 ◽  
Vol 63 (1) ◽  
pp. 63-71 ◽  
Author(s):  
G. C. Kearn ◽  
G. Cleveland ◽  
S. Wilkins
Keyword(s):  
Definitive Host ◽  
Cyst Wall ◽  
Bile Salts ◽  
In Vitro Study ◽  
Vitro Study ◽  
Metacercarial Cyst ◽  
A Minor

ABSTRACTIt has been established that the wall of the metacercarial cyst of the strigeid digenean Apatemon (Australapatemon) minor from the leech Erpobdella octoculata shares with Apatemon (Apatemon) gracilis the remarkable ability to expel the metacercaria forcibly from the cyst, an event which presumably occurs when the cysts are eaten by the bird definitive host. When cysts of A. minor are treated in vitro with a solution containing a mixture of bile salts and trypsin following pretreatment with acid pepsin, the metacercaria is expelled in an explosive manner through a canal at the narrow end of the pear-shaped cyst. This expulsion is produced by a sudden and substantial inward expansion of the birefringent wall, as a consequence of which the cyst lumen is virtually eliminated. Expulsion of the metacercaria in this explosive manner also occurs when similarly pretreated cysts are exposed to either bile salts alone or to trypsin, but cysts treated with the latter take longer to respond. When the cyst wall is perforated with a needle, inward expansion of the wall occurs and the metacercaria is forcibly ejected through the perforation. A variety of other pretreatments and treatments was tested but pepsin appears to be the most effective “primer”, apparently producing localized changes which permit the exit of the metacercaria. These observations are discussed in relation to the mechanism of expulsion.

The Structure and Histochemistry of some Trematode Metacercarial Cysts

1973 ◽  
Vol 47 (4) ◽  
pp. 353-368 ◽  
Author(s):  
M. F. Asanji ◽  
M. O. Williams
Keyword(s):  
Cyst Wall ◽  
Metacercarial Cyst ◽  
Parorchis Acanthus ◽  
Ecological Habitats

The nature and histochemistry of the metacercarial cyst wall of five species of trematodes of different ecological habitats was investigated. Both structurally and chemically, the cysts of Posthodiplostomum sp. and Posthodiplostomoides leoncnsis are similar. They differ from the metacercarial cysts of Parorchis acanthus, Posthodiplostomum nanum and Clinostomum tilapiae

Recurrence of Rathke’s Cleft Cysts Based on Gross Total Resection of Cyst Wall: A Meta-analysis

2020 ◽  
Author(s):  
Victor Lu ◽  
Avital Perry ◽  
Christopher Graffeo ◽  
Krishnan Ravindran ◽  
Jamie Van Gompel
Keyword(s):  
Cyst Wall ◽  
Meta Analysis ◽  
Gross Total Resection ◽  
Total Resection ◽  
Rathke's Cleft Cysts ◽  
Rathke's Cleft
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