Electron Microscope Studies of the Gland Cells and Host-Parasite Interface of the Adhesive Organ of Cyathocotyle bushiensis Khan, 1962

1965 ◽  
Vol 51 (5) ◽  
pp. 761 ◽  
Author(s):  
David A. Erasmus ◽  
Christina Ohman
Keyword(s):  
Electron Microscope ◽  
Gland Cells ◽  
Adhesive Organ ◽  
Host Parasite ◽  
Cyathocotyle Bushiensis

The host-parasite interface of Cyathocotyle bushiensis Khan, 1962 (Trematoda: Strigeoidea)

Parasitology ◽  
1968 ◽  
Vol 58 (2) ◽  
pp. 371-375 ◽  
Author(s):  
David A. Erasmus
Keyword(s):  
Electron Microscope ◽  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Plasma Membranes ◽  
Science Research ◽  
Strong Acid ◽  
Gland Cells ◽  
Adhesive Organ ◽  
Cyathocotyle Bushiensis

A combination of histochemical and electron microscope techniques have demonstrated, in Cyathocotyle bushiensis, alkaline phosphatase activity in the matrix of the tegument, in the distal and basal plasma membranes of the tegument, in the wall of the ducts extending from the adhesive organ gland cells and in the wall of the adhesive organ microvilli. Acid phosphatase activity was much stronger and was present in the tegument matrix and in the granular component of the secretion from the adhesive organ gland cells. Strong acid phosphatase activity was also present in the cisternae of the endoplasmic reticulum of the adhesive organ gland cells.I am greatly indebted to Professor Brough for the excellent facilities available within this department. I also wish to thank Professor J. Sinclair (Department of Mining) for electron microscope facilities extended to me in the early stages of this investigation, and to Mr W. Henderson, Mr T. Davies and Miss M. Williams for their invaluable assistance. The purchase of the Huxley ultramicrotome, coating unit and an AEI EM 6 electron microscope was made possible by a grant from the Science Research Council.

The structure and function of the adhesive organ in strigeid trematodes

Parasitology ◽  
1966 ◽  
Vol 56 (3) ◽  
pp. 481-491 ◽  
Author(s):  
Christina Öhman
Keyword(s):  
Leucine Aminopeptidase ◽  
Gland Cells ◽  
Adhesive Organ ◽  
Diplostomum Spathaceum ◽  
Secretory Products ◽  
And Function ◽  
The University ◽  
Cyathocotyle Bushiensis

The biology and life-cycle of Holostephanus lühei is briefly described. The similarities in morphology between the adhesive organ gland cells of H. lühei and Cyathocotyle bushiensis are stressed. Alkaline and acid phosphatases were demonstrated in the adhesive organ gland cells and cuticle. Acid phosphatase also occurs in the caecal cells. Non-specific esterase, sensitive to E600 10−5M and Mipafox 10−3M, is present in the gland cells. The caeca contain a non-specific esterase sensitive to AgNO3 10−2M and PCMB 10−4M. Leucine aminopeptidase is present in the gland cells. The in vitro studies confirmed that the secretory products pass to the exterior of the parasite and have a histolytic action.The four strigeids studied, Cyathocotyle bushiensis, Holostephanus lühei, Diplostomum spathaceum and Apatemon gracilis minor, are compared and the biological role of the secreted enzymes are discussed.My sincere thanks are due to Dr D. A. Erasmus for suggesting this line of investigation and for his encouragement during the study. I am also grateful for his performing, on my behalf, the infection experiments and criticizing the manuscript. I wish to thank Professor J. Brough for his interest in the progress of the work, and the University College, Cardiff, for a grant from William E. Morgan's Bequest.

Studies on the host–parasite interface of strigeoid trematodes

Parasitology ◽  
1969 ◽  
Vol 59 (1) ◽  
pp. 245-256 ◽  
Author(s):  
David A. Erasmus
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
The Body ◽  
Placental Function ◽  
Adhesive Organ ◽  
Basement Layer ◽  
Host Parasite ◽  
Surface Specialization ◽  
Research Grant

The adhesive organ of Apatemon gracilis minor Yamaguti, 1933, consists of two lobes lying in a cup-shaped fore-body. The cytoplasmic tegument covering the apposing faces of the lobes is different from that covering their outer surfaces. The covering of the outer surface corresponds to the general tegument present on the rest of the body, whereas that on the inner surfaces is finely pitted and in certain regions is elevated to form a coarse reticulum. This specialized surface is covered externally by a plasma membrane and is in continuity with nucleated cell bodies lying below the basement layer. The cell bodies contain large quantities of granular endoplasmic reticulum as well as several Golgi complexes and numerous mitochondria. Masses of secretion bodies are present and these also occur in the extensions to the external tegument as well as within the external tegument of the lobes. When the parasite is attached the inner faces of the lobes come into contact with the vascular lamina propria of the host. The possible biological role of this specialized host–parasite interface is discussed and it is suggested that this surface specialization may form a morphological basis for the ‘placental’ function suggested for the adhesive organ by earlier workers.The author wishes to acknowledge the research grant provided by the S.R.C. for the purchase of a vacuum coating unit and an AEI EM 6 electron microscope. The progress of this study was greatly facilitated by the excellent assistance of Mr T. Davies and Miss C. Green. The Stereoscan micrographs are published by permission of the Cambridge Instrument Company.

The host-parasite interface of strigeoid trematodes

Parasitology ◽  
1970 ◽  
Vol 61 (1) ◽  
pp. 35-41 ◽  
Author(s):  
David A. Erasmus
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
The Body ◽  
Sense Organs ◽  
Adhesive Organ ◽  
Transmission Electron ◽  
Transmission Studies ◽  
Host Parasite ◽  
Surface Specialization

A detailed study of the structure of the tegument of D. phoxini has been carried out using probe and transmission electron microscope. The distribution of spines and sense organs on the forebody has been described, as well as the nature of the lappets in the everted and retracted state. The adhesive organ exhibits two different surfaces which also differ from the surface of the rest of the body. The use of the ‘Stereoscan’ has confirmed and extended the concept of surface specialization based on transmission studies.

Studies on the host–parasite interface of strigeoid trematodes

Parasitology ◽  
1969 ◽  
Vol 59 (1) ◽  
pp. 193-201 ◽  
Author(s):  
David A. Erasmus
Keyword(s):  
Electron Microscope ◽  
Granular Material ◽  
Host Tissue ◽  
Gland Cells ◽  
Host Parasite ◽  
Fine Granular Material ◽  
Research Grant

The ultrastructure of the lappets of Apatemon gracilis minor Yamaguti, 1933, has been described. The tegument covering the lappets is characterized by the presence of long seta-like structures and unicellular gland cells which exhibit a holocrine type of secretion. The setae contain extensions of the tegument cytoplasm and are supported by a bundle of fibrils. The unicellular gland cells are pear-shaped with the tapering neck supported by a ring of 50–60 microtubules. The secretion consists of relatively large, membrane bounded bodies containing a fine granular material.The lappets are regarded as representing a specialized host–parasite interface in which adaptation exists for attachment to the host tissue and the discharge of secretion from the parasite at this region. The concept of the specialized host–parasite interface is discussed and extended to include Apatemon gracilis minor.The author wishes to acknowledge the research grant provided by the S.R.C. for the purchase of a vacuum coating unit and an AEI EM 6 electron microscope. The progress of this study was greatly facilitated by the excellent assistance of Mr T. Davies and Miss C. Green. The stereoscan micrograph (P1. 1, fig. 2) is published by permission of the Cambridge Instrument Company.

scholarly journals Secretion of a cytoplasmic lectin from Xenopus laevis skin.

1986 ◽  
Vol 102 (2) ◽  
pp. 492-499 ◽  
Author(s):  
N C Bols ◽  
M M Roberson ◽  
P L Haywood-Reid ◽  
R F Cerra ◽  
S H Barondes
Keyword(s):  
Electron Microscope ◽  
Xenopus Laevis ◽  
Mucous Gland ◽  
Gland Cells ◽  
Binding Lectin

The skin of Xenopus laevis contains a soluble beta-galactoside-binding lectin with a approximately 16,000-mol-wt subunit. It resembles similar lectins purified from a variety of tissues from other vertebrates, and differs from two other soluble X. laevis lectins from oocytes and serum that bind alpha-galactosides. The skin lectin is concentrated in the cytoplasm of granular gland and mucous gland cells, as demonstrated by immunohistochemistry with the electron microscope. Upon injection with epinephrine, there is massive secretion of the cytoplasmic lectin from the granular gland cells.

Observations on the Structure of Hydra as seen with the Electron and Light Microscopes

1957 ◽  
Vol s3-98 (43) ◽  
pp. 315-326
Author(s):  
ARTHUR HESS ◽  
A. I. COHEN ◽  
ELAINE A. ROBSON
Keyword(s):  
Electron Microscope ◽  
Longitudinal Muscle ◽  
Homogeneous Layer ◽  
Muscle Fibres ◽  
Digestive Cells ◽  
Characteristic Appearance ◽  
Dense Granules ◽  
Gland Cells ◽  
Cytoplasmic Continuity ◽  
Transverse Muscle

Sections of hydra studied with the electron microscope show various structures which have been identified by referring to control histological sections and to previous descriptions. Certain features have also been examined in frozen-dried sections under the light microscope. In the ectoderm, epithelio-muscular cells contain various organelles, and also smooth longitudinal muscle-fibres with which mitochondria may be associated. The so-called ‘supporting fibres’ appear to be thin bundles of muscle-fibres. Although points of contact exist between muscle-fibres, there appears to be no cytoplasmic continuity. The muscle-fibres insert on the mesogloea, and appear to be separated from it by two membranes, one belonging to the cytoplasm surrounding the musclefibreand the other to the mesogloea. The mesogloea is extracellular and quite distinct from the intracellular muscle-fibres. It appears granular and sometimes presents an indistinct fibrous background. In frozen-dried material the mesogloea stains blue with Mallory's method, while the muscle-fibres stain red. Two main types of cells are found in the endoderm. Among these, some of the digestive cells contain transverse muscle-fibres, but they are less distinct than the longitudinal ectodermal fibres. Otherwise the digestive cells vary much in structure, but generally they contain vacuoles and their free surface is thrown into villi covered with small granules. The ‘foamy gland cells’ are filled with much larger vacuoles containing granular material. The vacuoles are discharged together with portions of cytoplasm, and at this stage lamellated double membranes and mitochrondria appear between the vacuoles. Both types of cell possess two flagella, which show a typical ultrastructure and are surrounded by a thick membrane. Various other cells of the ectoderm are distinguished by their characteristic appearance. Cnidoblasts, for instance, have been found to contain an extensive system of intercommunicating vacuoles bounded by membranes, and do not resemble the interstitial cells. In unexploded penetrant nematocysts the tube is preformed and the butt nd stylets can also be seen. The special gland-cells of the pedal disk show large, lectron-dense granules which are extruded from the cell without any cytoplasm. A relatively thick homogeneous layer on the surface of the pedal disk is distinguished by the electron microscope.

The structure and function of the adhesive organ in strigeid trematodes

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 481-502 ◽  
Author(s):  
Christina Öhman
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Aminopeptidase Activity ◽  
Short Account ◽  
Gland Cells ◽  
Adhesive Organ ◽  
Diplostomum Spathaceum ◽  
And Function ◽  
Host Tissues

A short account of the biology and life-cycle of Diplostomum spathaceum is given.The morphology of the forebody is described in some detail. The lappets are well developed and function as organs of attachment as well as being reservoirs for the secretion from the forebody gland cells. The adhesive organ is variable in form and the muscles facilitating the movements are described in detail. Pressure changes in the excretory system are thought to assist in evaginating the adhesive organ.The histochemical tests gave the following results. The phosphatases present in the adhesive organ and the forebody gland cells are of the acid variety, the alkaline phosphatase is only present in the cuticle, traces of it occur in the lappets and forebody gland cells. No leucine aminopeptidase activity was observed. The esterase present is either a pseudocholinesterase or a non-specific B-esterase. The presence of RNA is confined to areas of enzyme formation.The in vitro studies confirmed the absence of alkaline phosphatase and the presence of acid phosphatase and esterase in the forebody. They also showed a secretion of acid phosphatase and esterase to the exterior of the parasite.Diplostomum spathaceum has very little effect on the host mucosa, but some lysis of the host tissues in contact with the forebody and especially the lappets, is observed. The response of the host to the parasite is likewise very small.The source of nutrients for D. spathaceum is believed to be the contents of the host alimentary tract, host mucus secretions and to a small extent disintegrated host tissues.I am very grateful to Dr D. A. Erasmus for advice and encouragement during this study and to Professor J. Brough for his interest and for provision of excellent working facilities. The work was conducted during the tenure of a Rotary Foundation Scholarship for International Understanding and a grant from Nylands Nation (Helsingfors, Finland).

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