Fasciola hepatica: a technique for the study of gut penetration by juvenile flukes

Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 249-252 ◽  
Author(s):  
D. J. Burden ◽  
A. P. Bland ◽  
D. L. Hughes ◽  
N. C. Hammet
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Fasciola Hepatica ◽  
Body Cavity ◽  
The Body ◽  
Ultrathin Sections ◽  
Resistance To Infection ◽  
Electron Microscopes

SUMMARYA method using light and electron microscopes is described which is suitable for the examination of gut penetration by juvenile Fasciola hepatica. It involved the ligation of small sections of the small intestine of rats and the introduction of artificially excysted flukes into these gut loops. By restricting the area of infection in this way it was possible to either recover flukes from the gut lumen or to prepare ultrathin sections for electron microscopy of flukes penetrating the gut wall. In addition, flukes were recovered from the body cavity at various times after preparation of loops in resistant and naive rats. It was found that more flukes reached the body cavity in naive rats than in resistant rats, demonstrating a resistance to infection in the gut loops of sensitized rats.

Studies on the excystment of trematode metacercariae in vivo

1974 ◽  
Vol 48 (1) ◽  
pp. 85-91 ◽  
Author(s):  
M. F. A. Asanji ◽  
M. O. Williams
Keyword(s):  
Small Intestine ◽  
Definitive Host ◽  
Fasciola Hepatica ◽  
Clonorchis Sinensis ◽  
Body Cavity ◽  
The Body ◽  
Parorchis Acanthus ◽  
Migratory Route ◽  
Ph Range

AbstractMetacercariae of two species of trematode (Clinostomum tilapiae, Postodiplostomum nanum) excysted in the stomach of birds, while those of three species (Parorchis acanthus, Posthodiplostomum sp., Postliodiplostomoides leonensis) excysted in the duodenum. Differences were related to the structure of the cyst wall. All could excyst in birds which were not the definitive host and the speed of excystment depended on the speed of movement of food in the gut. All, except P. acanthus, also excysted in the body cavity of the mouse.There have been few previous reports on the site of excystment of metacercarial cysts in vivo and most indicate that the duodenum is the site for most species studied, e.g. Clonorchis sinensis (Faust and Khaw, 1927), Parorchis avitus (Stunkard and Cable, 1932), Cryptocotyle lingua (Smyth, 1962) and Fasciola hepatica (Smyth, 1966). In their study of the migratory route of Paragonimus westermani in rats, cats and guinea-pigs Yokogawa et al. (1962) found that excystment occurred in the small intestine where the pH range was 5.0–6.0. Also, although the site of excystment has been established for some species, very little quantitative work has been reported about the percentage excystment in vivo and results of work on these lines is reported in this paper.

scholarly journals The development of Psychodiella sergenti (Apicomplexa: Eugregarinorida) in Phlebotomus sergenti (Diptera: Psychodidae)

Parasitology ◽  
2012 ◽  
Vol 139 (6) ◽  
pp. 726-734 ◽  
Author(s):  
LUCIE LANTOVA ◽  
PETR VOLF
Keyword(s):  
Electron Microscopy ◽  
Developmental Stages ◽  
Periodic Acid ◽  
Body Cavity ◽  
The Body ◽  
Sand Fly ◽  
Intestinal Lumen ◽  
Periodic Acid Schiff ◽  
Phlebotomus Sergenti ◽  
Schiff Reaction

SUMMARYPsychodiella sergenti is a recently described specific pathogen of the sand fly Phlebotomus sergenti, the main vector of Leishmania tropica. The aim of this study was to examine the life cycle of Ps. sergenti in various developmental stages of the sand fly host. The microscopical methods used include scanning electron microscopy, transmission electron microscopy and light microscopy of native preparations and histological sections stained with periodic acid-Schiff reaction. Psychodiella sergenti oocysts were observed on the chorion of sand fly eggs. In 1st instar larvae, sporozoites were located in the ectoperitrophic space of the intestine. No intracellular stages were found. In 4th instar larvae, Ps. sergenti was mostly located in the ectoperitrophic space of the intestine of the larvae before defecation and in the intestinal lumen of the larvae after defecation. In adults, the parasite was recorded in the body cavity, where the sexual development was triggered by a bloodmeal intake. Psychodiella sergenti has several unique features. It develops sexually exclusively in sand fly females that took a bloodmeal, and its sporozoites bear a distinctive conoid (about 700 nm long), which is more than 4 times longer than conoids of the mosquito gregarines.

A microscopic study ofPasteurella tularensisin the human body louse

Parasitology ◽  
1957 ◽  
Vol 47 (3-4) ◽  
pp. 435-446 ◽  
Author(s):  
Roger D. Price
Keyword(s):  
Life Span ◽  
Human Body ◽  
Body Cavity ◽  
The Body ◽  
Susceptibility To Infection ◽  
Complete Resistance ◽  
Resistance To Infection ◽  
Normal Life Span ◽  
Midgut Lumen ◽  
Human Body Louse

1.P. tularensismay be abundant in the midgut lumen, the epithelial cells of the anterior third of the midgut, and the haemolymph of the louse. Multiplication is extracellular in the lumen and the haemolymph and intracytoplasmic in the gut cells.2. The multiplication of the tularemia organisms in the midgut epithelium eventually leads to the disruption of these cells and the break-through of the organisms into the body cavity. The growth of these organisms in the haemocoele results in the death of the louse in 4–7 days.3. Lice vary greatly in their susceptibility to infection. Some lice show complete resistance to infection; others are capable of retaining the infection essentially for their normal life span, i.e. 35 days; still others apparently succumb to a rapid increase of the organisms in a relatively brief time after infection.4. The behaviour ofP. tularensiswithin the louse presents interesting similarities to infection of lice with the rickettsiae pathogenic to humans.

Fasciola hepatica: surfaces involved in movement of miracidia and cercariae

2001 ◽  
Vol 75 (1) ◽  
pp. 1-5 ◽  
Author(s):  
C.E. Bennett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fasciola Hepatica ◽  
Time Lapse ◽  
Ventral Surface ◽  
The Body ◽  
Power Stroke ◽  
Free Swimming ◽  
Lateral Plane ◽  
Scanning Electron

Rapid freezing and substitution with fixative prior to scanning electron microscopy was used to demonstrate the pattern of beat and recovery of the cilia of free swimming miracidia ofFasciola hepatica. There were stages of dexioplectic metachronal co-ordination and the power stroke was approximately 15° anticlockwise from the anterior–posterior axis. Around the circumference of the body of the miracidia there were approximately 12 metachronal waves of power and recovery. Free-swimming cercariae were recorded by time-lapse photography and, after conventional fixation, by scanning electron microscopy. Cercarial tail-beats were to the posterior of the body in the lateral plane at a rate of 8 Hz. The tail has paired lateral ridges positioned to act as leading edges. There is an array of 32 sensory papillae on the mid-ventral surface of the tail. The tegument of the most distal part of the tail is described: it is free of sensory endings and the surface shows a spiral pattern.

scholarly journals Choledocystus elegans (Digenea: Plagiorchiidae) of Leptodactylus paraensis (Amphibia: Leptodactylidae) from the Brazilian Amazon

2017 ◽  
Vol 26 (4) ◽  
pp. 511-515 ◽  
Author(s):  
Tássia Fernanda Furo Gomes ◽  
Francisco Tiago de Vasconcelos Melo ◽  
Elane Guerreiro Giese ◽  
Adriano Penha Furtado ◽  
Jeannie Nascimento dos Santos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Small Intestine ◽  
Brazilian Amazon ◽  
The Body ◽  
Pore Region ◽  
C Elegans ◽  
Morphological Aspects ◽  
First Time ◽  
Scanning Electron

Abstract The trematodes are parasites of the several vertebrates including amphibians, however the knowledge about of the taxonomy these parasites is still confuse. The trematode Choledocystus elegans was found in the small intestine of the Leptodactylus paraensis in eastern Amazon and presents the following characteristics: several pointed tegumentary spines, papillae on the outer and inner edges of the oral and ventral suckers, a round, well-developed cirrus sac, a well-developed cirrus, oblique testicles, a ovary right side, uterine loops extending between the testicles, follicular vitellaria distributed throughout the body, starting at the genital pore region and caeca close the end of the body. For the first time, this study identified C. elegans parasitizing L. paraensis and describes morphological aspects never characterized using light and scanning electron microscopy.

Tem Studies of Hen's Perivitelline Membrane Hydrolysis by Cock Sperm in Vitro

1976 ◽  
Vol 34 ◽  
pp. 364-365
Author(s):  
M. R. Bakst
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ringer Solution ◽  
Body Cavity ◽  
The Body ◽  
Ground Substance ◽  
Transmission Electron ◽  
Membrane Hydrolysis ◽  
Perivitelline Membrane

In a manner analogous to the way in which the zona pellucida envelops the mammalian ovum, a single acellular investment, the perivitelline membrane (PM), uniformly covers the hen's ovum at the time of ovulation. It consists of a fiberous latticework 2-4μm in width with interstices occupied by a porous ground substance (Figs. 1,2). The PM overlying the blastodisc is preferentially hydrolyzed in vitro by cock sperm (1) or by partially purified cock sperm acrosin (2). With either agent the PM overlying the remainder of the ovum requires longer incubation times for hydrolysis.Transmission electron microscopy of blastodisc and non-blastodisc regions of ova removed from the body cavity immediately after ovulation and incubated with sperm in modified Krebs-Ringer solution for 10-15 min. clearly demonstrates this breakdown.

scholarly journals ELECTRON MICROSCOPY OF ENTOMOPATHOGENIC FUNGAL INVASION ON THE CABBAGE-HEART CATERPILLAR CROCIDOLOMIA BINOTALIS ZELLER (LEPIDOPTERA: PYRALIDAE)

2017 ◽  
Vol 19 (2) ◽  
pp. 111-125
Author(s):  
N. Hashim ◽  
Y.B. Ibrahim ◽  
Y.H. Tan
Keyword(s):  
Electron Microscopy ◽  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Body Cavity ◽  
The Body ◽  
Paecilomyces Fumosoroseus ◽  
Infected Larva ◽  
Crocidolomia Binotalis ◽  
Lepidoptera Pyralidae

The infection on Crocidolomia binotalis Zeller by the entomopathogenic fungi Paecilomyces fumosoroseus (Wise) Brown and Smith, Beauveria bassiana (Bals.) Vuill, and Metarhizium anisopliae var. majus (Metsch.) Sorokin was studied histopathologically using electron microscopy. Conidia which landed on the cuticle germinated within four to six hours. In the case of B. basiana, shortly after landing, an appresorium was formed that attached itself fast onto the cuticle at the point of fungal entry. The infected larva then entered the moribund state 12 to 24 hours after inoculation. Death of the larva followed 24 to 48 hours later. By then the body cavity as well as the trachea were clogged with mycelia, and compacted masses conidiophores producing white conidia were found all over the larval cadaver one to two days later. P. fumosoroseus sporulated more abundantly on the surface of the cadaver compared to B. bassiana or M. anisopliae.

scholarly journals BMP signaling controls buckling forces to modulate looping morphogenesis of the gut

2017 ◽  
Vol 114 (9) ◽  
pp. 2277-2282 ◽  
Author(s):  
Nandan L. Nerurkar ◽  
L. Mahadevan ◽  
Clifford J. Tabin
Keyword(s):  
Small Intestine ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Tissue Level ◽  
Body Cavity ◽  
Bmp Signaling ◽  
The Body ◽  
Differential Growth ◽  
Bmp Pathway ◽  
Dorsal Mesentery

Looping of the initially straight embryonic gut tube is an essential aspect of intestinal morphogenesis, permitting proper placement of the lengthy small intestine within the confines of the body cavity. The formation of intestinal loops is highly stereotyped within a given species and results from differential-growth–driven mechanical buckling of the gut tube as it elongates against the constraint of a thin, elastic membranous tissue, the dorsal mesentery. Although the physics of this process has been studied, the underlying biology has not. Here, we show that BMP signaling plays a critical role in looping morphogenesis of the avian small intestine. We first exploited differences between chicken and zebra finch gut morphology to identify the BMP pathway as a promising candidate to regulate differential growth in the gut. Next, focusing on the developing chick small intestine, we determined that Bmp2 expressed in the dorsal mesentery establishes differential elongation rates between the gut tube and mesentery, thereby regulating the compressive forces that buckle the gut tube into loops. Consequently, the number and tightness of loops in the chick small intestine can be increased or decreased directly by modulation of BMP activity in the small intestine. In addition to providing insight into the molecular mechanisms underlying intestinal development, our findings provide an example of how biochemical signals act on tissue-level mechanics to drive organogenesis, and suggest a possible mechanism by which they can be modulated to achieve distinct morphologies through evolution.

Philometrid nematodes (Philometridae) of marine teleosts from Balinese waters, Indonesia, including the description of Philometra damriyasai sp. nov. 

Zootaxa ◽  
2017 ◽  
Vol 4341 (4) ◽  
pp. 577 ◽  
Author(s):  
KARTIKA DEWI ◽  
HARRY W. PALM
Keyword(s):  
Electron Microscopy ◽  
New Species ◽  
Body Cavity ◽  
Marine Fishes ◽  
The Body ◽  
Nemipterus Japonicus ◽  
Otolithes Ruber ◽  
First Time ◽  
One New Species ◽  
Scanning Electron

Based on light and scanning electron microscopy, one new species of philometrid nematodes, Philometra damriyasai sp. nov. (Nematoda: Dracunculoidea: Philometridae) from the body cavity of Tylerius spinosissimus (Regan, 1908) (Tetraodontiformes, Tetraodontidae), and five known species are reported in different marine teleosts from South Bali, Indonesia. The new species can be distinguished from the most closely related P. javensis Moravec, Walter & Juniar, 2012 by the absence of sclerotized denticles on the cuticle of the anterior oesophageal lobes of the mouth and smaller larvae. Philometra nemipteri Luo, 2001 of Nemipterus japonicus (Bloch, 1791), P. otolithi Moravec & Manoharan, 2013 of Otolithes ruber (Bloch & Schneider, 1801) (both from gonads) and Philometroides marinus Moravec & Buron, 2009 from the body cavity of Rachycentron canadum (Linnaeus, 1766) are reported for the first time from Indonesian waters, thus extending their range of distribution into the tropical Indo-Pacific Ocean. Philometra lobotidis Moravec, Walter & Yuniar, 2012 from the body cavity of Lobotes surinamensis (Bloch, 1790) and P. ocularis Moravec, Ogawa, Suzuki, Miyaki & Donai, 2002 from the eye cavity of Variola louti (Forsskål, 1775) represent new geographical records, and Philometra sp. was recorded for the first time from Cephalopholis sexmaculata (Rüppell, 1830). A total of 14 philometrids have been so far identified from marine fishes in Indonesia. 

scholarly journals Scanning electron microscopy of newly excysted juvenile and adult Cyclocoelum mutabile (Digenea)

1999 ◽  
Vol 77 (7) ◽  
pp. 1111-1116 ◽  
Author(s):  
D D Tajrine ◽  
N N Kapoor ◽  
J D McLaughlin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Adult Stage ◽  
Body Cavity ◽  
The Body ◽  
Surface Structures ◽  
Entire Body ◽  
Mouth Region ◽  
Air Sacs ◽  
Scanning Electron

In this study, changes were examined in surface structures and tegumental morphology of newly excysted, migrating, and adult Cyclocoelum mutabile obtained from experimentally infected coots (Fulica americana). Newly excysted juveniles were spinous and had two large depressions situated at the anterior tip of the body and a large acetabulum. Small papillae were scattered around the mouth region and also formed a row that encircled the anterior end of the fluke. Four groups of larger papillae, two ventrolateral and two lateral, originated from points slightly posterior to the mouth region. The two ventrolateral bands of papillae terminated slightly posterior to the acetabulum; the two lateral rows of papillae terminated about three-quarters of the length along the specimen. Six large multilobed papillae were associated with the acetabulum. Juveniles migrating through the liver lost the spines and papillae by day 6, but the anterior depressions persisted into the adult stage. The tegument of 6- and 12-day-old flukes was smooth with a varying number of transverse folds. The tegument of 15-day-old specimens from the body cavity ranged in appearance from folded and pitted to reticulate. The reticulations were more prominent in adults and the entire body was covered with a reticulate pattern of loculus-like structures that are believed to aid in the movement of the flukes within the air sacs of the coot host.

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