Phosphorus kinetics in calves experimentally submitted to a trickle infection with Cooperia punctata

Ten male Holstein calves (74.3 +/- 3.2 kg LW) were used for a trial with trickle infection with Cooperia punctata to evaluate phosphorus (P) kinetics. Five calves were inoculated with 10,000 L(3) stage larvae per week during 35 days, while the other group of five calves was kept as a control. On the 29th day each calf was intravenously injected with 29.6 MBq of a (32)p solution. Blood samples were taken at 24 h periods for 7 days, after which all calves were slaughtered and worms burdens. Faeces, urine and tissue samples were taken for analysis using isotopic dilution and modeling techniques. The number of eggs per gram of faeces (EPG)was 1920 +/- 168 on 28th day and the total number of worms burdens was 11,131 +/- 1500. Infected calves showed lower feed intake and live weight gain, as well as lower P intake, absorption and retention than control calves. The P flows between body compartments were lower for blood to gastrointestinal tract (TGI), TGI to blood, blood to soft tissues, bone balance and soft tissue balance in infected calves when compared to the control. The trickle infection of C punctata affected P metabolism due to the decrease in P retained and live weight due to fall in feed intake. (C) 2009 Elsevier B.V. All rights reserved.

A comparison of anterior adhesive areas and secretions in Troglocephalus rhinobatidis and Neoheterocotyle rhinobatidis (Monogenea : Monocotylidae) from the gills of the shovelnose ray, Rhinobatos typus (Rhinobatidae)

This study continues the collection of data on the anterior adhesive areas and secretions of monopisthocotylean monogenean (flatworm) parasites and begins an investigation of their phylogenetic usefulness. Here, two species of parasitic worms from an elasmobranch, Troglocephalus rhinobatidis (Monocotylidae: Dasybatotreminae) and Neoheterocotyle rhinobatidis (Monocotylidae: Heterocotylinae), are compared and contrasted. It has been suggested in recent literature that these two taxa are more closely related than is currently recognised. Our data support this view. Both species have multiple apertures on the ventral anterior margin through which adhesive is secreted. Two types of secretion exit from multiple adjacent duct endings terminating in each aperture: rod-shaped (S1) and spherical-shaped (S2) bodies. S1 bodies of both species show nano-banding of similar size and are membrane bound. Ultrastructure of the glands, ducts, duct endings and secreted adhesive is similar for both species, but aperture shape differs. Away from the adhesive areas, tegumental inclusions are found to differ between the two species and another, apparently non-adhesive, secretion is found in N. rhinobatidis.

A description of Lecithocladium invasor n.sp (Digenea : Hemiuridae) and the pathology associated with two species of Hemiuridae in acanthurid fish

Lecithocladium invasor n.sp. is described from the oesophagus of Naso annulatus, N. tuberosus and N. vlamingii on the Great Barrier Reef, Australia. The worms penetrate the oesophageal mucosa and induce chronic transmural nodular granulomas, which expand the full thickness of the oesophageal wall and protrude both into the oesophageal lumen and from the serosal surface. We observed two major types of lesions: large ulcerated, active granulomas, consisting of a central cavity containing a single or multiple live worms; and many smaller chronic fibrous submucosal nodules. Small, identifiable but attenuated, worms and degenerate worm fragments were identified within some chronic nodules. Co-infection of the posterior oesophagus of the same Naso species with Lecithocladium chingi was common. L. chingi is redescribed from N. annulatus, N. brevirostris, N. tuberosus and A vlamingii. Unlike L. invasor n.sp., L. chingi was not associated with significant lesions. The different pathenogenicity of the two species in acanthurid fish is discussed.

Occurrence and histopathogenesis of a didymozoid trematode (Gonapodasmius epinepheli) in pond-reared orange-spotted grouper, Epinephelus coioides

A didymozoid trematode encapsulated in the gills of orange-spotted grouper, Epinephelus coioides Hamilton, was observed in October 1997 and September 1999 among pond-reared fish in the Philippines. Capsule prevalence was 33% and 18% and mean intensity 2 and 1, respectively. The opaque-white and yellowish capsules were found only on the first gill arch and were attached lengthwise along the posterior surface of the primary gill filaments. When the capsules were opened, long thread-like worms were revealed, which were identified as Gonapodasmius epinepheli Abdul-Salam, Sreelatha and Farah. The parasites were encapsulated between the basement membrane of the epithelium and the efferent artery of the gill filament. The response of the host included mild hyperplasia of the interlamellar epithelium and an increase in the number of mucous cells. (C) 2001 Elsevier Science B.V. All rights reserved.

A technique for preserving pigmentation in some capsalid monogeneans for taxonomic purposes

A technique is described to preserve the pigment found in the bodies and the intestine of some brightly coloured and darkly pigmented benedeniine capsalid monogeneans. Previous studies of these pigmented capsalids have proven difficult because the pigmentation usually disappears when the worms are fixed using preservatives containing concentrations of formalin over 5% and/or ethanol, acetic acid, chromic acid, picric acid and mercuric chloride. The technique developed here uses a fixative comprising glycerol, acetone and formalin (GAF). After fixation under light coverslip compression for three minutes, specimens are transferred to absolute acetone for three minutes and cleared in a mixture of nine parts cedar wood oil and one part absolute acetone before mounting in Canada balsam. Processing must be carried out quickly, as these chemicals will cause the pigments to fade if the specimens are exposed to them for too long. Pigmented benedeniines processed using this technique retain the distribution, intensity and colour observed in live worms. The colour and distribution of pigmentation in monogeneans may be of taxonomic importance and this technique aids preparation of whole-mounts suitable for registration as type-material.

Immune responses in hookworm infections

Hookworms infect perhaps one-fifth of the entire human population, yet little is known about their interaction with our immune system. The two major species are Necator americanus, which is adapted to tropical conditions, and Ancylostoma duodenale, which predominates in more temperate zones. While having many common features, they also differ in several key aspects of their biology. Host immune responses are triggered by larval invasion of the skin, larval migration through the circulation and lungs, and worm establishment in the intestine, where adult worms feed on blood and mucosa while injecting various molecules that facilitate feeding and modulate host protective responses. Despite repeated exposure, protective immunity does not seem to develop in humans, so that infections occur in all age groups (depending on exposure patterns) and tend to be prolonged. Responses to both larval and adult worms have a characteristic T-helper type 2 profile, with activated mast cells in the gut mucosa, elevated levels of circulating immunoglobulin E, and eosinoophilia in the peripheral blood and local tissues, features also characteristic of type I hypersensitivity reactions. The longevity of adult hookworms is determined probably more by parasite genetics than by host immunity. However, many of the proteins released by the parasites seem to have immunomodulatory activity, presumably for self-protection. Advances in molecular biotechnology enable the identification and characterization of increasing numbers of these parasite molecules and should enhance our detailed understanding of the protective and pathogenetic mechanisms in hookworm infections.

The Antarctic nemertean Parborlasia corrugatus: an example of an extreme oxyconformer

The Antarctic nemertean worm, Parborlasia corrugatus, exhibits gigantism, reaching at least 100 g, yet lacks any specialised respiratory organs. The diffusion of oxygen into this worm occurs cutaneously. We examined the metabolic rate of P. corrugatus at -1degreesC in response to decreasing ambient PO2. As the PO2 of the water decreased. so did the metabolic rate of P. corrugatus, indicating that this nemertean worm is an extreme example of an oxyconformer. When the water PO2 decreased below about 120 mmHg, the normally short, round worms became elongated and extremely flattened. This behavioural mechanism would allow for an increase in surface area of the skin, thereby facilitating the diffusion of oxygen.

Cleavage of hemoglobin by hookworm cathespin D aspartic proteases and its potential contribution to host specificity

Hookworms routinely reach the gut of nonpermissive hosts but fail to successfully feed, develop, and reproduce. To investigate the effects of host-parasite coevolution on the ability of hookworms to feed in nonpermissive hosts, we cloned and expressed aspartic proteases from canine and human hookworms. We show here that a cathepsin D-like protease from the canine hookworm Ancylosotoma caninum (Ac-APR-1) and the orthologous protease from the human hookworm Necator americanus (Na-APR-1) are expressed in the gut and probably exert their proteolytic activity extracellularly. Both proteases were detected immunologically and enzymatically in somatic extracts of adult worms. The two proteases were expressed in baculovirus, and both cleaved human and dog hemoglobin (Hb) in vitro. Each protease digested Hb from its permissive host between twofold (whole molecule) and sixfold (synthetic peptides) more efficiently than Hb from the nonpermissive host, despite the two proteases' having identical residues lining their active site clefts. Furthermore, both proteases cleaved Hb at numerous distinct sites and showed different substrate preferences. The findings suggest that the paradigm of matching the molecular structure of the food source within a host to the molecular structure of the catabolic proteases of the parasite is an important contributing factor for host-parasite compatibility and host species range.

Neuro-angiostrongylosis in wild Black and Grey-headed flying foxes (Pteropus spp)

Objective To identify nematodes seen in histological sections of brains of flying foxes (fruit bats) and describe the associated clinical disease and pathology. Proceedures Gross and histological examination of brains from 86 free-living flying foxes with neurological disease was done as part of an ongoing surveillance program for Australian bat lyssavirus. Worms were recovered, or if seen in histological sections, extracted by maceration of half the brain and identified by microscopic examination. Histological archives were also reviewed. Results There was histological evidence of angiostrongylosis in 16 of 86 recently submitted flying foxes with neurological disease and in one archival case from 1992. In 10 flying foxes, worms were definitively identified as Angiostrongylus cantonensis fifth-stage larvae. A worm fragment and third stage larvae were identified as Angiostrongylus sp, presumably A cantonensis, in a further three cases. The clinical picture was dominated by paresis, particularly of the hind-limbs, and depression, with flying foxes surviving up to 22 days in the care of wildlife volunteers. Brains containing fifth-stage larvae showed a moderate to severe eosinophilic and granulomatous meningoencephalitis (n = 14), whereas there was virtually no inflammation of the brains of bats which died when infected with only smaller, third-stage larvae (n = 3). There was no histological evidence of pulmonary involvement. Conclusion This is the first report of the recovery and identification of A cantonensis from free-living Australian wildlife. While anglostrongylosis is a common cause of paresis in flying foxes, the initial clinical course cannot be differentiated from Australian bat lyssavirus infection, and wildlife carers should be urged not to attempt to rehabilitate flying foxes with neurological disease.

The spread of Angiostrongylus cantonensis in Australia

Until the recent establishment of Angiostrongylus cantonensis in North America. Australia was the only developed region endemic for this parasite. Almost 50 years ago the life cycle was elucidated there, in the city of Brisbane, and the first human infections probably occurred in 1959. From the 1970s, increasing numbers of autochthonous infections have been reported along the central east coast of the continent (southeast Queensland and northern New South Wales), involving humans, rats, dogs, horses, flying foxes and marsupials. Ten years ago, the parasite was discovered in Sydney, almost 1,000 km to the south, in dogs. In that city, it has since been diagnosed as a cause of neurological disease in increasing numbers of dogs, flying foxes, marsupials and zoo primates. Presumably, these infections resulted from the ingestion of snails or slugs, and it seems that virtually all species of native and exotic terrestrial molluscs can serve as intermediate hosts. It is not known how the parasite was introduced to this continent, or how it has spread over such an extensive territory, although eventually its range could encompass the entire east coast, and potentially other regions. It is also not known if the almost identical, native species, A. mackerrasae, is able to infect people (or other non-rodent hosts). All worms recovered to date, from one fatal human case, and from many animal infections, have been confirmed as A. cantonensis.

Current concepts - Schistosomiasis

In 1851, Theodor Bilharz described a parasitic infection (bilharzia) that would later be termed schistosomiasis. Currently, 200 million people in 74 countries have this disease; 120 million of them have symptoms, and 20 million have severe illness.1 Schistosomiasis is caused by parasitic trematode worms (schistosomes) that reside in the abdominal veins of their vertebrate definitive hosts. The life cycle of the schistosome is depicted in Figure 1. Schistosomiasis is 1 of the 10 tropical diseases especially targeted for control by the Special Program for Research and Training in Tropical Diseases of the United Nations Development Program, the World Bank, . . . [Full Text of this Article]

Dactylomyza gibsoni n.g., n. sp (Digenea: Opecoelidae) from Schuettea woodwardi (Waite) (Monodactylidae) from off Western Australia

An opecoelid digenean, Dactylomyza gibsoni n. g., n. sp. is described and figured from Schuettea woodwardi (Waite), a monodactylid from off the coast of Western Australia. The new genus conforms to the concept of the opecoelid subfamily Opecoelinae. The resemblance of the new genus to three other opecoelid genera, Pseudopecoeloides Yamaguti, 1940, Opecoeloides Odhner, 1928 and Poracanthium Dollfus, 1948, is discussed. Dactylomyza n. g. is distinguished from these morphologically similar worms on the basis of its median genital pore, ventral sucker appendages, uroproct and the absence of an accessory sucker. Pseudopecoeloides equesi Manter, 1947 is transferred to the new genus as Dactylomyza equesi (Manter, 1947) n. comb.

Experimental human infection with the dog hookworm, Ancylostoma caninum

Objective: To investigate possible routes for human infection by the dog hookworm (Ancylostoma caninum). Design, setting and participant. Relatively small numbers of infective larvae were administered orally and percutaneously to an informed healthy volunteer (J K L) under medical supervision, at intervals between May 1998 and May 1999. Main outcome measures: Symptoms; weekly blood eosinophil counts; faecal microscopy. Results: A marked blood eosinophilia followed a single oral exposure to 100 infective larvae, while faecal examination remained negative. Eosinophil counts then declined gradually, although a rapid, spontaneous rise several months later, at the beginning of spring, possibly indicated reactivation of dormant larvae. Blood eosinophil numbers did not rise significantly after percutaneous infection with 200 larvae. A subsequent, smaller, oral inoculum of 20 larvae provoked an eosinophil response similar to that of the first experiment. Conclusions: Our findings suggest that, following ingestion, some infective larvae of A. caninum develop directly into adult worms in the human gut (as they do in dogs). While the percutaneous route might be the most common means of human exposure to canine hookworm larvae, leading generally to subclinical infection, oral infection may be more likely to provoke symptomatic eosinophilic enteritis.

Biodegradation and ecotoxicity evaluation of a bionolle and starch blend and its degradation products in compost

A polymer based on a blend of starch and Bionolle(TM) has been prepared and tested for biodegradation in compost. The polymer was completely mineralised to carbon dioxide in 45 days. The potential toxicity of the polymer was tested against the earthworm Eisenia fetida using a modification of the American Standard for Testing Materials E1976-97. The earthworms were exposed to 30 g of the polymer for 28 days and changes in weight recorded. In addition, the polymer was firstly degraded by the compost and the worms exposed to the breakdown products for 28 days. Differences in weight were also recorded. In each case the production of juveniles was noted and all earthworms were examined for pathology. The results obtained were processed statistically using a t-test. The number of juveniles, produced from the breakdown products, was highly significant (P < 0.001) when compared to the earthworms added to the intact polymer. There was a definitely significant difference (P < 0.01, t = 3.25) in change in weight between the earthworms that were exposed to the polymer directly and those that were exposed to the breakdown products. There was no indication of any pathology of any earthworms. The polymer is considered safe for this species. (C) 2002 Elsevier Science Ltd. All rights reserved.

Active Assistance for Senior Healthcare: A Wearable System for Fall Detection

Elders lose independence and wellbeing, accompanied by decreased functions in terms of hearing, vision, strength and coordination abilities. These factors contribute to balance difficulties that eventually lead to falls. The injuries due to falls, at this age, are risky, since most of the times may cause a significant – and permanent – decrease of quality of life or, in extreme cases, death. In this context, a fall detection system can bring an added value to assist elderly people.This paper describes a system consisting of a wearable sensor unit, a smartphone and a website. When the sensor detects a fall it sends an alert using the smartphone via Bluetooth 4.0, to notify the family members or stakeholders. The sensor device includes an inertial unit, a barometer, and a temperature and humidity sensor. The website displays the log of previous falls and enables the configuration of emergency contact numbers. The proposed fall detection system is one of multiple components within a larger project under development that offers a holistic perspective on falls; the complete wearable solution will also feature, among others, physical protection (minimizing the impact of falls that occur).