Ultrastructure of the tegument of the trematode Ganeo tigrinum parasitizing the intestine of indian frogs

AbstractThe surface tegument of G. tigrinum generally resembles that described for other digeneans. It contains surface tubercles and is covered with a glycocalyx. In the anterior region the tegument bears spines while tubular-like canals and occasional deep invaginations are present on the anteroventral surface. Two types of secretory body are present in the tegumental syncytium and produced in separate tegumental cells. Mitochondria are present in the surface syncytium, suggesting active transport occurs across the tegument in non-hibernating frogs.

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Ultrastructural changes to the tegumental system and gastrodermal cells of adult Fasciola hepatica following treatment in vivo with a commercial preparation of myrrh (Mirazid)

Journal of Helminthology ◽

10.1017/s0022149x16000705 ◽

2016 ◽

Vol 91 (6) ◽

pp. 672-685 ◽

Cited By ~ 3

Author(s):

M.M.O. Abdelaal ◽

G.P. Brennan ◽

A. Abdel-Aziz ◽

I. Fairweather

Keyword(s):

Fasciola Hepatica ◽

Ultrastructural Changes ◽

Muscle Fibres ◽

Somatic Muscle ◽

Secretory Body ◽

Commercial Preparation ◽

Transmission Electron ◽

Body Production ◽

Tegumental Syncytium

AbstractAn in vivo study in the laboratory rat model has been carried out to monitor changes to the tegument and gut of adult Fasciola hepatica following treatment with myrrh (‘Mirazid’). Rats infected with the triclabendazole-resistant Dutch isolate were dosed orally with Mirazid at a concentration of 250 mg/kg and flukes recovered 2, 3 and 7 days post-treatment (pt). The flukes were processed for examination by scanning and transmission electron microscopy. A variety of changes to the external surface were observed, culminating in the sloughing of the tegumental syncytium. Internal changes to the syncytium and tegumental cell bodies were more severe and were evident from 2 days pt onwards. Swelling of the basal infolds (leading to flooding of the surface layer) and a decline in secretory body production were the major changes seen. The gastrodermal cells were less severely affected than the tegument, pointing to a trans-tegumental route of uptake for Mirazid by the fluke. Some loss of muscle fibres in the main somatic muscle layers was observed, which may be correlated with the decline in movement of flukes seen at recovery.

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Ultrastructural observations on the redial tegument of Paramphistomum epiclitum from the planorbid snail, Indoplanorbis exustus

Journal of Helminthology ◽

10.1017/s0022149x00014516 ◽

1992 ◽

Vol 66 (3) ◽

pp. 167-176 ◽

Cited By ~ 3

Author(s):

T. S. Dunn ◽

P. H. Dang ◽

G. Mattison ◽

R. E. B. Hanna ◽

W. A. Nizami

Keyword(s):

Outer Surface ◽

Apical Membrane ◽

Single Type ◽

Sensory Receptors ◽

Secretory Body ◽

Indoplanorbis Exustus ◽

Paramphistomum Epiclitum ◽

Single Nucleus ◽

Uptake Of Nutrients ◽

Tegumental Syncytium

ABSTRACTThe morphology of the tegument in the redia of Paramphistomum epiclitum (Digenea: Paramphistomidae) resembles that shown by most larval and adult digeneans; an outer surface syncytium is in continuity with the cytoplasm of in-sunken, nucleated cytons. Although tegumental cytons usually contain a single nucleus, some display up to six nuclei. The tegumental syncytium lining the pharynx of P. epiclitum rediae lack underlying cytons. The apical membrane of the tegument is elaborated by folds and microvilli, which presumably facilitate uptake of nutrients and/or exchange of ions involved in osmoregulation. A single type of secretory body, resulting from the fusion of smaller vesicles produced at Golgi complexes in the cytons, occurs throughout the tegument. Uniciliate sensory receptors occur in the surface syncytium particularly around the oral opening.

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Ultrastructure and histochemistry of the tegument of juvenile paramphistomes during migration in Indian ruminants

Journal of Helminthology ◽

10.1017/s0022149x00014371 ◽

1994 ◽

Vol 68 (3) ◽

pp. 211-221 ◽

Cited By ~ 6

Author(s):

R.G. Mattison ◽

R.E.B. Hanna ◽

W.A. Nizami

Keyword(s):

Apical Membrane ◽

Secretory Body ◽

Paramphistomum Epiclitum ◽

T1 And T2 ◽

Tegumental Syncytium

AbstractThe tegument of juvenile Paramphistomum epiclitum and Fischoederius elongatus (Paramphistomidae: Digenea) resembles those of other digeneans. Seven types of papillae were observed, mostly on the oral and acetabular surfaces, and increase in number during migration. Also evident are two types of secretory body (T1 and T2) which are synthesized separately in tegumental cytons underlying the syncytium. Exocytosis of T2 bodies occurs at the apical membrane and appears to contribute to a fibrous glycocalyx. The tegumental syncytium lining the pharynx and acetabulum is thinner and has a higher capacity for vacuolation than the general tegument. These may represent important sites for osmoregulation. The absence of mitochondria from the tegument in migrating juveniles suggests limited involvement in energy demanding processes. Pigmentation of the subtegument is first evident in mature cercariae and is progressively eliminated during migration.

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Ultrastructure of the tegument of the metacercaria ofTimoniella imbutiforme

Journal of Helminthology ◽

10.1017/s0022149x00000081 ◽

2000 ◽

Vol 74 (1) ◽

pp. 57-66 ◽

Cited By ~ 3

Author(s):

H.E.M. El-Darsh ◽

P.J. Whitfield

Keyword(s):

Basal Lamina ◽

Larval Stage ◽

The Body ◽

Secretory Body ◽

Gland Cells ◽

Normal Configuration ◽

Secretory Gland ◽

Tegumental Syncytium ◽

Somatic Muscles ◽

Sensory Endings

AbstractThe spinous body tegument of the metacercaria ofTimoniella imbutiforme(Molin, 1859) is described in detail and found to comprise an outer tegumental syncytium connected to subjacently situated subtegumentary ‘cells’. There are four types of secretory bodies in the outer syncytial layer as well as serrated overlapping spines and mitochondria. The subtegumentary ‘cells’ are characterized by the presence of four secretory body types as well as giant bodies which may be involved in the elaboration of the secretory bodies or spine material. The normal configuration of the somatic muscles ofT. imbutiformeshow that the muscular machinery necessary for activity once the larval stage becomes excysted is already in place. The sensory endings are found to be of the uniciliate type occurring in groups of up to eight in raised domes distributed over the body. Secretory gland cells are numerous and possess long ducts connected to the basal lamina of the outer syncytial layer via septate desmosomes.

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On the structural organization of biological pumps and channels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110878 ◽

1984 ◽

Vol 42 ◽

pp. 138-141

Author(s):

G. Zampighi ◽

M. Kreman

Keyword(s):

Active Transport ◽

Transport System ◽

Plasma Membranes ◽

Transport Proteins ◽

Molecular Organization ◽

Passive Transport ◽

Concentration Gradients ◽

Cell Functions ◽

Natural Concentration ◽

Active Transport System

The plasma membranes of most animal cells contain transport proteins which function to provide passageways for the transported species across essentially impermeable lipid bilayers. The channel is a passive transport system which allows the movement of ions and low molecular weight molecules along their concentration gradients. The pump is an active transport system and can translocate cations against their natural concentration gradients. The actions and interplay of these two kinds of transport proteins control crucial cell functions such as active transport, excitability and cell communication. In this paper, we will describe and compare several features of the molecular organization of pumps and channels. As an example of an active transport system, we will discuss the structure of the sodium and potassium ion-activated triphosphatase [(Na+ +K+)-ATPase] and as an example of a passive transport system, the communicating channel of gap junctions and lens junctions.

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