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J Riley - One of the best experts on this subject based on the ideXlab platform.
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proteins and proteinases in the in vitro released products ivrp of the tissue invasive and lung dwelling larvae of the pentastomid Porocephalus crotali
Parasitology, 2002Co-Authors: A C Buckle, D P Knox, J RileyAbstract:Pentastomids are arthropod-like parasites which inhabit the respiratory tract of tetrapods and, despite being haematophagous, cause little or no visible pathology. Nymphs (or larvae), belonging to the advanced genus Porocephalus, encyst in the tissues of rodent intermediate hosts and migrate from this site to the lung following ingestion of the intermediate host. During migration, several moults occur and instars encounter a variety of tissue barriers and environmental cues. It was therefore relevant to define the proteins and proteinases released by the different instars during this migration as they are likely to be essential for tissue penetration, feeding and immune evasion. In vitro released proteins (IVRP), commonly termed ES, were defined on the basis of molecular size and immune recognition by naturally infected rodent intermediate hosts. In addition, proteinases present in IVRP were characterized using gelatin-substrate gels and protein degradation assays. These studies showed that the protein profile is subtly different when IVRP from different instars is compared. In addition, IVRP from each instar contained metallo-proteinases with proteolysis at 48 kDa dominating in all stages. However, other higher molecular weight activities were, to an extent, released in a stage-specific manner. These proteinases degraded haemoglobin and fibrinogen as well as structural proteins such as collagen and fibronectin, suggesting roles in bloodmeal digestion and tissue penetration. Immunoglobulin digestion was not demonstrated.
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Pentastomids and the tetrapod lung.
Parasitology, 1999Co-Authors: J Riley, R J HendersonAbstract:Pentastomids comprise a highly specialized taxon of arthropod-like parasites that probably became adapted to the lungs of amphibians and reptiles early in their long evolutionary history. Few other macroparasites exploit this particular niche. Pentastomids are often large, long-lived and yet they cause little observable pathology in lungs, despite being haematophagous. The lungs of all tetrapods are lined with pulmonary surfactant, a remarkable biological material consisting of a complex mixture of phospholipids, neutral lipids and proteins that has the unique ability to disperse over the air-liquid lining of the lung. In the lower tetrapods it acts as an anti-glue preventing adhesion of respiratory surfaces when lungs collapse during swallowing prey or upon expiration. In mammals, pulmonary surfactant also plays a critical role regulating the activity of alveolar macrophages, the predominant phagocytes of the lower airways and alveoli. This review outlines the evidence suggesting that lung-dwelling pentastomids, and also nymphs encysted in the tissues of mammalian intermediate hosts, evade immune surveillance and reduce inflammation by coating the chitinous cuticle with a their own stage-specific surfactant. The lipid composition of surfactant derived from lung instars of the pentastomid Porocephalus crotali cultured in vitro is very similar to that recovered from the lung of its snake host. Pentastomid surfactant, visualised as lamellate droplets within sub-parietal cells, is delivered to the cuticle via chitin-lined efferent ducts that erupt at a surface density of < 400 mm -2 The fidelity of the system, which ensures that every part of the cuticle surface is membrane-coated, testifies to its strategic importance. Two other extensive glands discharge membrane-associated (hydrophobic?) proteins onto the hooks and head; some have been purified and partly characterized but their role in minimising inflammatory responses is, as yet, undetermined.
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the in vitro development of the pentastomid Porocephalus crotali from the infective instar to the adult stage
Parasitology, 1997Co-Authors: A C Buckle, J Riley, G F HillAbstract:The in vitro development of the pentastomid Porocephalus crotali from the infective, seventh (VII) instar, dissected from the tissues of rat intermediate hosts, to the adult male (X) and female (XI) instars, normally resident in the lung of rattlesnake definitive hosts, is described. The culture medium comprised washed human blood cells, resuspended in bovine serum (50[ratio ]50, v/v), with 20% minimum essential medium and antibiotics. Two batches of approximately 100 pentastomids, maintained at a density of 2 worms/ml, were cultured in 500 ml bottles in an atmosphere of 5% CO 2 in air at 28°C. Culture bottles were rotated slowly on a Rollacell system and the medium was replenished every 2–3 days. Growth was monitored at various intervals by weighing worms, measuring cast cuticles with attached moulted hooks recovered from the medium, and by dissecting worms for measurements of various organ systems. Three moults separated the infective and adult male instar, whereas 4 moults were necessary in the case of females. In both cultures natural mortality was about 10% over a 160-day period, by which time 33–51% of females and 62–70% of males had reached the terminal instar. Some males attained full sexual maturity with seminal vesicles loaded with viable sperm: such males were indistinguishable from males recovered from naturally infected rattlesnakes. However, females never achieved full size, even after 200 days, and although copulation did not occur in vitro , some females became patent.
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The in vitro development of the pentastomid Porocephalus crotali from the infective instar to the adult stage.
Parasitology, 1997Co-Authors: A C Buckle, J Riley, G F HillAbstract:The in vitro development of the pentastomid Porocephalus crotali from the infective, seventh (VII) instar, dissected from the tissues of rat intermediate hosts, to the adult male (X) and female (XI) instars, normally resident in the lung of rattlesnake definitive hosts, is described. The culture medium comprised washed human blood cells, resuspended in bovine serum (50:50, v/v), with 20% minimum essential medium and antibiotics. Two batches of approximately 100 pentastomids, maintained at a density of 2 worms/ml, were cultured in 500 ml bottles in an atmosphere of 5% CO2 in air at 28 degrees C. Culture bottles were rotated slowly on a Rollacell system and the medium was replenished every 2-3 days. Growth was monitored at various intervals by weighing worms, measuring cast cuticles with attached moulted hooks recovered from the medium, and by dissecting worms for measurements of various organ systems. Three moults separated the infective and adult male instar, whereas 4 moults were necessary in the case of females. In both cultures natural mortality was about 10% over a 160-day period, by which time 33-51% of females and 62-70% of males had reached the terminal instar. Some males attained full sexual maturity with seminal vesicles loaded with viable sperm: such males were indistinguishable from males recovered from naturally infected rattlesnakes. However, females never achieved full size, even after 200 days, and although copulation did not occur in vitro, some females became patent.
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The recruitment of mast cells, exclusively of the mucosal phenotype, into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali: recruitment is irrespective of site.
Parasitology, 1993Co-Authors: P Mchardy, J Riley, J F HuntleyAbstract:Adults of the porocephalid pentastomid Porocephalus crotali infect the lung of rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early stage in infections, granulomas become increasingly infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype. Mucosal mast cells are concentrated along the dorsal region of the parasite and in a plug of tissue containing degenerating cuticles within independent granulomas, which is located between its head and tail. ELISAs against the rat mast cell proteases I and II (RMCP I and II), extracted from abdominal fat, lung, spleen, liver and kidney granulomas at various intervals post-infection, reveal a substantially elevated concentration of RMCP II in all lesions. In fat, concentrations increase up to about 100 days post-infection, at which time moulting ceases and inflammatory responses subside. RMCP II was scarcely detectable in matched control tissues. Unlike infections with certain nematode parasites, where enteric mucosal mast cells secrete RMCP II systemically, concentrations of RMCP II in the serum of infected rats were significantly reduced when compared with age-matched uninfected controls. These results confirm that P. crotali can selectively recruit mucosal mast cells to a variety of tissue sites, most of which are non-mucosal. Possible mechanisms are discussed.
J F Huntley - One of the best experts on this subject based on the ideXlab platform.
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The recruitment of mast cells, exclusively of the mucosal phenotype, into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali: recruitment is irrespective of site.
Parasitology, 1993Co-Authors: P Mchardy, J Riley, J F HuntleyAbstract:Adults of the porocephalid pentastomid Porocephalus crotali infect the lung of rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early stage in infections, granulomas become increasingly infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype. Mucosal mast cells are concentrated along the dorsal region of the parasite and in a plug of tissue containing degenerating cuticles within independent granulomas, which is located between its head and tail. ELISAs against the rat mast cell proteases I and II (RMCP I and II), extracted from abdominal fat, lung, spleen, liver and kidney granulomas at various intervals post-infection, reveal a substantially elevated concentration of RMCP II in all lesions. In fat, concentrations increase up to about 100 days post-infection, at which time moulting ceases and inflammatory responses subside. RMCP II was scarcely detectable in matched control tissues. Unlike infections with certain nematode parasites, where enteric mucosal mast cells secrete RMCP II systemically, concentrations of RMCP II in the serum of infected rats were significantly reduced when compared with age-matched uninfected controls. These results confirm that P. crotali can selectively recruit mucosal mast cells to a variety of tissue sites, most of which are non-mucosal. Possible mechanisms are discussed.
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the recruitment of mast cells exclusively of the mucosal phenotype into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali recruitment is irrespective of site
Parasitology, 1993Co-Authors: P Mchardy, J Riley, J F HuntleyAbstract:Adults of the porocephalid pentastomid Porocephalus crotali infect the lungof rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early- stage in infections, granulomas become increasingly' infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype
Armando Yarleque Ch - One of the best experts on this subject based on the ideXlab platform.
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identificacion de Porocephalus stilessi pentastomida en la serpiente peruana lachesis muta
Revista de Investigaciones Veterinarias del Perú, 2012Co-Authors: Ines Garate C, Asucena I Naupay, Beatriz Suyo L, Hugo Colquichagua A, Edith Rodriguez Q, Armando Yarleque ChAbstract:Se realizo la necropsia a una serpiente venenosa Lachesis muta (Familia Vipiridae), procedente de Satipo, Junin, de 1.95 cm de longitud y 9 anos, que se encontraba cautiva en el serpentario de la Universidad Nacional Mayor de San Marcos, Lima. Se encontro cuatro pentastomidos en la cavidad corporal y en la serosa pulmonar. Los parasitos fueron fijados en formol al 10% y diafanizados con lactofenol. El estudio morfologico determino que tres de ellos eran hembras, pues tenian el gonoporo en el extremo posterior y el cuerpo cilindrico semejante al de un anelido, en tanto que el cuarto parasito era macho, ya que presentaba la parte anterior dilatada y el poro genital en la region anterior, cerca de la boca. La presencia de 4 ganchos, donde los situados en la zona mas externa tenian un apendice poco esclerotizado y fragil, revelaba que eran adultos. Las hembras presentaban 47 anillos y median 8.3, 7.5 y 6.9 cm de longitud, y el macho media 3.7 cm y tenia 39 anillos. Estas caracteristicas corresponden a individuos de la especie Porocephalus stilessi, considerandose el primer reporte de esta especie en serpientes del Peru.
P Mchardy - One of the best experts on this subject based on the ideXlab platform.
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The recruitment of mast cells, exclusively of the mucosal phenotype, into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali: recruitment is irrespective of site.
Parasitology, 1993Co-Authors: P Mchardy, J Riley, J F HuntleyAbstract:Adults of the porocephalid pentastomid Porocephalus crotali infect the lung of rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early stage in infections, granulomas become increasingly infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype. Mucosal mast cells are concentrated along the dorsal region of the parasite and in a plug of tissue containing degenerating cuticles within independent granulomas, which is located between its head and tail. ELISAs against the rat mast cell proteases I and II (RMCP I and II), extracted from abdominal fat, lung, spleen, liver and kidney granulomas at various intervals post-infection, reveal a substantially elevated concentration of RMCP II in all lesions. In fat, concentrations increase up to about 100 days post-infection, at which time moulting ceases and inflammatory responses subside. RMCP II was scarcely detectable in matched control tissues. Unlike infections with certain nematode parasites, where enteric mucosal mast cells secrete RMCP II systemically, concentrations of RMCP II in the serum of infected rats were significantly reduced when compared with age-matched uninfected controls. These results confirm that P. crotali can selectively recruit mucosal mast cells to a variety of tissue sites, most of which are non-mucosal. Possible mechanisms are discussed.
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the recruitment of mast cells exclusively of the mucosal phenotype into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali recruitment is irrespective of site
Parasitology, 1993Co-Authors: P Mchardy, J Riley, J F HuntleyAbstract:Adults of the porocephalid pentastomid Porocephalus crotali infect the lungof rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early- stage in infections, granulomas become increasingly' infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype
Volker Storch - One of the best experts on this subject based on the ideXlab platform.
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Further spermatological evidence for including the pentastomida (tongue worms) in the Crustacea
International Journal for Parasitology, 1992Co-Authors: Volker Storch, Barrie G. M. JamiesonAbstract:Abstract The ultrastructure of the spermatozoa of three species of the Pentastomida is investigated: the cephalobaenids Raillietiella sp. and Cephalobaena tetrapoda, and the porocephalid Porocephalus crotali. Phylogenetic relationships of pentastomids with their putative maxillopodan and remipedian relatives have been deduced from sperm ultrastructure intuitively and by parsimony analysis using the PAUP program of Swofford (1990, Version 3.01, Illinois Natural History Survey, Champaign, IL). A remarkable degree of homogeneity in the ultrastructure of the spermatozoa of cephalobaenids and porocephalids is demonstrated and a sister-group relationship of pentastomids and Branchiura, first proposed by Wingstrand (1972, Kongelige Danske Videnskab Selskab Biologiske Skrifter19: 1–72), is confirmed. Spermatozoal synapomorphies of the Pentastomida and the branchiuran Argulus include: absence of an acrosome vesicle and filament in the mature spermatozoon; presence of a pseudoacrosome, about 30 μm long, divisible into a dorsal and a ventral component (the dorsal and ventral rod), and derived from pericentriolar structures; continuation of the dorsal rod with the dorsal ribbon of an axonemal sheath and with material embedding the centriolar doublets 1, 2 and 9; continuation of the ventral rod with material embedding the more ventrally situated doublets; presence of the axonemal sheath; presence of a connective from the dorsal ribbon to axonemal doublet 1; presence in the spermatid of nine dense fibres peripheral to the doublets; great elongation of the three mitochondria parallel to the nucleus; and total incorporation of the axoneme in the spermatozoon so that a free flagellum is absent. The sperm of the pentastome-branchiuran assemblage appear to be the most highly evolved of the flagellate crustacean sperm.
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microscopic anatomy and ultrastructure of the male genital system in Porocephalus crotali and p stilesi pentastomida porocephalida
Parasitology Research, 1990Co-Authors: Volker Storch, Wolfgang Böckeler, J RileyAbstract:The male genital systemPorocephalus crotali andP. stilesi consists of an unpaired testis, Y-shaped or paired seminal vesicles, paired ejaculatory bulbs (ducts), vasa deferentia, cirri, cirrus sacs, and dilators. Cirri and dilators can travel into the genital atrium. An ultrastructural analysis of each of these components is presented, including sperm development, which has been traced through some important stages. The main differences between the male genital systems of the two subgroups of Pentastomida (Cephalobaenida and Porocephalida) concern the anatomy of the seminal vesicle, the shape and ultrastructure of the ejaculatory bulbs (ducts), the existence of cirrus sacs, the length of the coiled cirrus within the sacs, and the structure of the dilators. However, ultrastructural features reveal homologies between the various components of the male genital systems of cephalobaenids and porocephalids.
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Microscopic anatomy and ultrastructure of the male genital system inPorocephalus crotali andP. stilesi (Pentastomida: Porocephalida)
Parasitology Research, 1990Co-Authors: Volker Storch, Wolfgang Böckeler, John RileyAbstract:The male genital system Porocephalus crotali and P. stilesi consists of an unpaired testis, Y-shaped or paired seminal vesicles, paired ejaculatory bulbs (ducts), vasa deferentia, cirri, cirrus sacs, and dilators. Cirri and dilators can travel into the genital atrium. An ultrastructural analysis of each of these components is presented, including sperm development, which has been traced through some important stages. The main differences between the male genital systems of the two subgroups of Pentastomida (Cephalobaenida and Porocephalida) concern the anatomy of the seminal vesicle, the shape and ultrastructure of the ejaculatory bulbs (ducts), the existence of cirrus sacs, the length of the coiled cirrus within the sacs, and the structure of the dilators. However, ultrastructural features reveal homologies between the various components of the male genital systems of cephalobaenids and porocephalids.