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

1992 ◽  
Vol 66 (3) ◽  
pp. 167-176 ◽  
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.

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

1994 ◽  
Vol 68 (3) ◽  
pp. 211-221 ◽  
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.

Regional specializations of the tegument of the metacercaria ofTimoniella imbutiforme

2000 ◽  
Vol 74 (1) ◽  
pp. 67-72 ◽  
Author(s):  
H.E.M. El-Darsh ◽  
P.J. Whitfield
Keyword(s):  
Oral Sucker ◽  
Outer Surface ◽  
Single Type ◽  
Apical Surface ◽  
Secretory Body ◽  
First Time

AbstractThe ultrastructure of the spinous body tegument of the metacercaria ofTimoniella imbutiforme(Molin, 1859) has recently been described. Other regions of the metacercarial tegument, including those of the oral sucker, pharynx, and nephridiopore, demonstrate considerable specializations. The oral sucker tegument had an aspinous outer syncytial layer that possessed a pimpled apical surface as well as enclosing two types of secretory bodies. The pharyngeal tegument likewise lacked spines, but possessed only one type of secretory body, and a smooth but folded outer surface. The nephridiopore tegument, however, showed the greatest degree of specialization possessing a single type of secretory body specific only to this region of the tegument. Also associated with the syncytium here was a prominent long filamentous glycocalyx, and microtubules which were observed for the first time in this region of the tegument.

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

2016 ◽  
Vol 91 (6) ◽  
pp. 672-685 ◽  
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.

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

1996 ◽  
Vol 70 (2) ◽  
pp. 137-142 ◽  
Author(s):  
P.N. Sharma ◽  
N. Rai ◽  
G.P. Brennan
Keyword(s):  
Active Transport ◽  
Anterior Region ◽  
Secretory Body ◽  
Tegumental Syncytium

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.

Isolation of a chloride channel-enriched membrane fraction from tracheal and renal epithelia

1992 ◽  
Vol 263 (4) ◽  
pp. C879-C887 ◽  
Author(s):  
C. L. Preston ◽  
M. A. Calenzo ◽  
W. P. Dubinsky
Keyword(s):  
Lipid Bilayers ◽  
Membrane Fraction ◽  
Plasma Membranes ◽  
Apical Membrane ◽  
Anion Channel ◽  
Single Type ◽  
Disulfonic Acid ◽  
Enzyme Analysis ◽  
Marker Enzyme ◽  
Cl Channels

A membrane fraction, enriched in Cl- channels, has been isolated from bovine tracheal epithelia and renal cortex homogenates by hydrophobic chromatography. The fraction (MPS) shows a 37-fold enrichment of Cl- channels over crude tracheal homogenates by net Cl- flux measurements. Alkaline phosphatase and Na(+)-K(+)-ATPase are not found in these membranes, suggesting that they are not apical or basolateral plasma membranes. Marker enzyme analysis for major subcellular membranes also proved negative. The MPS fraction exhibits a protein profile unlike that of other membrane fractions, with major proteins of 200 and 42 kDa, proteins of 30-35 kDa, and lesser amounts of other proteins. Reconstitution of MPS fractions from both trachea and kidney into planar lipid bilayers demonstrates the presence of a single type of anion channel. The current-voltage relationship of this channel is identical to that of the predominant anion channel observed in tracheal apical membranes under similar conditions (H. H. Valdivia, W. P. Dubinsky, and R. Coronado. Science Wash. DC 242: 1441-1444, 1988). In addition, the voltage dependence, selectivity sequence of Cl- > Br- > or = I-, and inhibition by low concentrations of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid correspond to those of the predominant apical membrane channel. Thus, although the MPS appear to be of subcellular origin, they may be functionally related to an apical membrane Cl- permeability.

Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus

1992 ◽  
Vol 66 (4) ◽  
pp. 243-254 ◽  
Author(s):  
T. S. Dunn ◽  
P. H. Dang ◽  
R. E. B. Hanna ◽  
W. A. Nizami
Keyword(s):  
Nurse Cell ◽  
Somatic Cells ◽  
Body Cavity ◽  
Mechanical Support ◽  
Nurse Cells ◽  
Embryological Development ◽  
Indoplanorbis Exustus ◽  
Paramphistomum Epiclitum ◽  
Cell Layers ◽  
Germinal Cells

ABSTRACTCercariae develop from individual germinal cells occurring freely within the posterior body cavity of rediae. Individual germinal cells give rise to a germinal ball which becomes enveloped by increasing numbers of cytoplasmic extensions originating from specialized parenchyma-like cells, termed nursc cells. Up to eight cytoplasmic layers of nurse cells invest larger germinal balls. These layers may provide mechanical support for developing embryos and/or play a role in the provision of nutrients to them. The cercarial tegument develops from superficially located somatic cells in the germinal ball. Cytoplasmic extensions of presumptive tegumental cells fuse laterally to form a syncytial layer beneath the encapsulating nurse cell layers. As the cercarial tegument differentiates further, the cytoplasm of the nurse cell layers becomes vacuolated and ultimately these layers degenerate. The surface tegumental syncytia of intra-redial cercariae and newly released extra-redial cercariae are nucleated. Separate subtegumental perikarya develop with further differentiation of extra-redial cercariae.

Sensory and other superficial structures in living marine Crustacea

1985 ◽  
Vol 76 (2-3) ◽  
pp. 123-136 ◽  
Author(s):  
M. S. Laverack ◽  
Y. Barrientos
Keyword(s):  
Outer Surface ◽  
Chemical Sensors ◽  
Gland Cell ◽  
The Body ◽  
Sensory Receptors ◽  
Environmental Signals ◽  
Different Types ◽  
Cell Opening ◽  
Decapod Larvae

ABSTRACTLiving Crustacea possess many types of sensory receptors that detect environmental signals. These structures allow the speculation that similar organs existed in fossil arthropods and were involved in similar ways in the fossil forms when they were extant.Posture, for example, is difficult to reconstruct in fossils without the understanding that internal proprioceptors monitoring position and movement are crucial in determining the placement of limbs, and the position of the abdomen and other jointed portions of the body. These receptors are associated also with autotomy reflexes through soft cuticle detectors that respond to strain not associated with joints.Many receptors are placed on the outer surface of the animal, the eyes being the most obvious. The eyes receive no attention in this paper, but descriptions are given of a number of different types of setae, serving both mechanical and chemical sensors. The possession of a pore at the apex (or sub-apex) of a seta or setule probably indicates a chemoreceptor function, but its absence does not necessarily indicate a lack of such sensitivity. A range of forms is illustrated.The dorsal organ is a recently discovered structure in decapod larvae. It is composed of a central single gland cell opening via an aperture in the midline just behind the rostrum. It is bounded by four depressions each containing a central ‘nipple’. These prove to be sensors, with ciliated endings (bifid) that end in a highly modified cuticle at the depression nipple. The function is unknown, but it is proposed that it represents an unusual chemoreceptor.

Ultrastructure of the tegument of the metacercaria ofTimoniella imbutiforme

2000 ◽  
Vol 74 (1) ◽  
pp. 57-66 ◽  
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.

Hope, exploration, and equilibrated action schemes

2019 ◽  
Vol 42 ◽  
Author(s):  
Davood G. Gozli ◽  
Ci Jun Gao
Keyword(s):  
Single Type ◽  
Reward Seeking ◽  
Stable Scheme

AbstractThe concepts want, hope, and exploration cannot be organized in relation to a single type of motive (e.g., motive for food). They require, in addition, the motive for acquiring and maintaining a stable scheme that enables reward-directed activity. Facing unpredictability, the animal has to seek not only reward, but also a new equilibrated state within which reward seeking is possible.

A scanning electron microscopic study on dissolving process of cholesterol gallstones by chenodeoxycholic acid (CDCA)

1978 ◽  
Vol 36 (2) ◽  
pp. 522-523
Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara
Keyword(s):  
Electron Microscope ◽  
Chenodeoxycholic Acid ◽  
Outer Surface ◽  
Electron Microscopic ◽  
Cholesterol Gallstones ◽  
The Core ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Acceleration Voltage ◽  
Scanning Electron

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.

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