bluuebunny/crossref_metadata_2025 huggingface dataset:
Large ranches as conservation tools in the Venezuelan llanos
Authors: Hoogesteijn Rafael , Chapman Colin A.
Published: November 2003

Traditionally, wildlife conservation efforts have concentrated on the establishment of national parks and reserves. Additional strategies are needed if we are to conserve more than a small proportion of the world's natural habitats and their wildlife. One such strategy is the application of wildlife conservation regulations by private land owners on their properties. This paper uses examples of ranches in the seasonally flooded llanos of Venezuela to evaluate if effective wildlife conservation can coexist with sustainable wildlife use and cattle production. Income estimates derived from cattle production data varied among ranches from $US7.1 to $US26.4 per ha, while estimates of potential additional income through regulated capybara Hydrochaeris hydrochaeris and caiman Caiman crocodilus exploitation ranged up to $US7.7 per ha. The economic benefits of capybara and caiman harvests can be realized only by protecting wildlife habitat. Thus, it is suggested that large ranches in the llanos can play a major role in wildlife conservation as well as provide economic gains for those involved. Common denominators for success are: personal involvement of owners, effective patrolling systems, co-operation of neighbouring ranchers in patrolling activities, and ranches being located far from densely populated areas. For the programmes to succeed in the long term, government and conservation agencies will need to give more support to landowners.
Argali Ovis ammon surveys in Mongolia's South Gobi
Authors: Reading Richard P. , Amgalanbaatar Sukhiin , Mix Henry , Lhagvasuren Badamjaviin
Published: November 2003

The argali, Ovis ammon, a species of wild sheep, is threatened in Mongolia, suffering from poaching and competition with domestic livestock. The authors conducted ground and aerial surveys of argali in Dundgobi, Omnogobi and Dornogobi aimags (or provinces) of the South Gobi region of Mongolia. Ground surveys were conducted by vehicle and on foot, while aerial surveys were conducted using two Soviet AN-2 aircraft flying 40-km parallel transects. The interactive computer programme Distance was used to estimate population size and density. The authors observed a total of 423 argali in 85 groups (mean group size = 5.0 ± 0.6 SE), including 300 individuals in 61 groups on the ground survey (mean size = 4.9 ± 0.8 SE) and 123 animals in 24 groups during the aerial survey (mean size = 5.1 ± 1.2 SE). Population structure of the groups observed during the ground survey was 14.3 per cent males, 53.3 per cent females, 19.7 per cent lambs, and 12.7 per cent animals of undetermined sex (means = 0.7 ± 0.2 SE males, 2.6 ± 0.6 SE females, 1.0 ± 0.2 SE lambs, and 0.6 ± 0.4 SE undetermined). We estimated a population size of 3900 ± 1132 SE argali in the study area for a population density of 0.0187 ± 0.0054 SE animals/sq km. More rigorous and comprehensive surveys for argali, preferably for each distinct population, should be conducted for more accurate estimates. Argali require more active conservation and management, especially with respect to poaching and competition with domestic livestock. If sport hunting is to continue, a large portion of all money
Conservation of the Okapi Wildlife Reserve, Zaïre
Authors: Stephenson Peter J. , Newby John E.
Published: November 2003

The Okapi Wildlife Reserve was created in May 1992 to conserve a representative area of the Ituri rainforest in north-eastern Zaïre. This article examines the threats facing this large protected area and summarizes the management actions proposed to address these problems within the next 10 years. Emphasis is placed on the need to integrate the local population into reserve management and to empower people as much as possible to manage their own resources. The long-term future of the reserve in the context of national economic and political instability is discussed.
The illegal market in tiger parts in northern Sumatra, Indonesia
Authors: Plowden Campbell , Bowles David
Published: November 2003

The Sumatran tiger is the only one of three original subspecies of tigers that survives in Indonesia today. Its wild population, estimated to be 400–650 animals, has progressively diminished because of habitat destruction, poaching and the removal of tigers involved in conflicts with local farmers. This paper presents previously undocumented information on the market in tiger products. It shows that, while no documentation of intentional tiger poaching to meet an international demand for tiger bones was recorded, the domestic demand for tiger bones, teeth and claws is still a potential threat to the future survival of this subspecies. In addition to continuing work to protect the integrity of tiger habitat in Sumatra, enforcement actions are required to prevent the domestic market for tiger parts increasing the threats to this subspecies and to ensure its conservation.
Distribution, status and conservation of primates in Monte Alen National Park, Equatorial Guinea
Authors: Garcia Juan E. , Mba Jesus
Published: November 2003

Equatorial Guinea has a new network of protected areas, but only Monte Alen National Park has any effective protection. As a contribution to the knowledge of this area, a survey of primate populations was carried out during a 7-month period in 1994. The results showed that there is a high primate diversity (15–16 distinct species) in Monte Alen. The three most commonly sighted monkey species were Cercopithecus nictitans (35.9–40.8 per cent of sightings), Cercopithecus cephus (28.9–43.5 per cent) and Cercopithecus pogonias (17.4–22.4 per cent). Mean distance covered to find any group of these guenons varied from 1.1km in open primary forest to 2.7 km in dense primary forest. Gorilla nests were more abundant in secondary forest near villages (5.15 nests/km), while chimpanzee nests were mostly found in primary forest (5.35 nests/km). Hunting pressure appears to be low but shifting agriculture has a significant impact on the conservation of the area. The degree of threat varies between species. Alternatives for better management of the area, such as educational programmes and sustainable use of natural resources, are suggested.
The status and management of the Mongolian gazelle Procapra gutturosa population
Authors: Lhagvasuren Badamjavin , Milner-Gulland E. J.
Published: November 2003

This article presents data on the ecology, exploitation and management of the Mongolian gazelle over the last few decades. The species has suffered a massive decline in its range area, coinciding with the construction of the Ulaanbaatar—Beijing railway in the 1950s. It is heavily hunted, both legally and illegally. Threats to the species are outlined and recommendations made about the conservation measures required to secure its future.
Preliminary observations on the Sumatran rhino in Way Kambas National Park, Indonesia
Authors: Reilly Joanne , Spedding Guy Hills , Apriawan
Published: November 2003

The Sumatran rhinoDicerorhinus sumatrensisis regarded as critically endangered with a world population of approximately 400. In 1991 it was recorded in Way Kambas National Park, Sumatra, Indonesia, 30 years after the park's last rhino was believed to have been shot. A Sumatran Rhino Population and Habitat Viability Analysis (PHVA) workshop in 1993 recommended an immediate survey be carried out to assess the rhino population in the park. The Way Kambas Project recorded observations of rhino sign between 1993 and 1995. Sign was most frequently observed along trails in mature secondary forest. Data from the areas surveyed suggest the presence of at least four rhinos.
The status of the Sumatran rhinoceros in north-eastern India
Authors: Choudhury Anwaruddin
Published: November 2003

The historical distribution of the Sumatran rhinocerosDicerorhinus sumatrensisstretched from the foothills of the eastern Himalaya in Bhutan and north-eastern India, through Myanmar and Indo-China to Borneo and Sumatra. However, because of poaching and habitat loss the species is now struggling for survival in a few pockets of Myanmar, Thailand, the Malay peninsula, Sumatra and Borneo (Khan, 1989).
The African elephant: conservation and CITES
Authors: Sharp Robin
Published: November 2003

Human beings have been making (and almost certainly trading in) ivory artefacts for some 10,000 years. Yet it is only 8 years since the Parties to the Convention on International Trade in Endangered Species (CITES) placed a complete ban on international trade in elephant products by listing the African elephant Loxodonta africana on Appendix I at Lausanne in 1989. Nevertheless, at the 10th Conference of the Parties to CITES in Harare this coming June, the listing will be challenged again by three of the Southern African countries who originally opposed it. This article describes what has happened on the ground since 1989, the political developments, examines the downlisting proposals, and looks at possible ways forward in the short- and medium-term. The views expressed are personal to the author.
Wildlife snaring – an indicator of community response to a community-based conservation project
Authors: Lewis Dale M. , Phiri Andrew
Published: November 2003

The use of wire snares for catching wildlife to support household needs was treated as an indicator to evaluate community support and understanding for a community-based resource management project. Data were based on snare counts in areas surrounding the targeted community as well as from interviews with individuals purported to have had a history of snaring. The high use of snares conflicted with expected behaviour for a community benefiting from the project. Snaring levels were high enough to threaten the viability of the safari industry and the derived revenues that were meant to be shared with the community. These contradictions suggested flaws in the project: an overdependence on external donor-supported management and lack of real community involvement and leadership in management of the resource. This study underscores the critical importance for monitoring land-use behaviour as an indicator of the success of community-based management projects.
A faunal survey of the Dieng Mountains, Central Java, Indonesia: distribution and conservation of endemic primate taxa
Authors: Nijman Vincent , van Balen S. (Bas)
Published: November 2003

A faunal survey was conducted in May–September 1994 and June–July 1995 in the Dieng Mountains, one of the last remaining larger patches of forest in CentralJava province, Indonesia. All three primate species endemic to the Javan faunal region – Javan gibbon Hylobates moloch, grizzled leaf monkey Presbytis comata and ebony leaf monkey Trachypithecus auratus – were found to be present. Hylobates moloch occurs only in the lowland and hill forests in the western part of the study area, while the other two species were found throughout the area from lowland to montane forests. Although more research needs to be done onhabitat preferences and densities at which the primates occur, the available data suggestthat the Dieng Mountains may harbour the second largest populations of both H. moloch and P. comata in the same location. In order to safeguard these two endangered primates itis suggested that the reserve system in Java be expanded to include the Dieng Mountains.
Surveys on Propithecus verreauxi deckeni, a melanistic variant, and P. v. coronatus in north-west Madagascar
Authors: Curtis Deborah J. , Velo Arsène , Raheliarisoa Evelyne-Odette , Zaramody Alphonse , Müller Pie
Published: November 2003

Propithecus verreauxi is currently divided into three or four subspecies. Decken's sifaka, P. v. deckeni, and the crowned sifaka, P. v. coronatus, are believed to be synonymous by some authors, while others regard them as separate subspecies. The results of a survey on an isolated melanistic population of Decken's sifaka, known from museum specimens collected in Ambararatabe, as well as the results of additional surveys carried out within the ranges of P. v. deckeni and P. v. coronatus are presented. A detailed description and photographs of the melanistic variant are provided. The data are employed to argue the case for recognition of the subspecific status of the endangered P. v. coronatus. The consistency of sightings of P. v. coronatus to the east of the river Mahavavy and to the west of the river Betsiboka, and sightings of P. v. deckeni to the west of the Mahavavy indicate clear separation of the two subspecies in the lower reaches of two rivers. Clarification of the status of the enigmatic museum specimens from Ambararatabe, representing a melanisticform rather than hybridization of P. v. deckeni and P. v. coronatus, lends further support to this argument.
The distribution, abundance and population trends of gentoo, rockhopper and king penguins in the Falkland Islands
Authors: Bingham M.
Published: November 2003

The Falkland Islands are a globally important breeding location for seabirds, including penguins. The total breeding populations of three of the four main penguin species present in the Falklands were censused in the austral summer of 1995/96. The results for gentoo and rockhopper penguins suggest declines of about 43 and 90 per cent, respectively, since a similar census in 1932/33. Recent monitoring studies suggest that these declines are still continuing; research to investigate causes (which is likely to reflect changes in the marine, rather than terrestrial environment) is a high priority. In contrast, king penguin populations, currently c. 400 pairs, have increased steadily, by 700 per cent since 1980/81, in line with world-wide trends for this species.
Translocation and introduction of the Zanzibar red colobus monkey: success and failure with an endangered island endemic
Authors: Struhsaker Thomas T. , Siex Kirstin S.
Published: November 2003

The Zanzibar red colobus Procolobus kirkii is one of Africa's most endangered primates, with only c. 1500–2000 individuals remaining in the wild. The authors made preliminary surveys of three areas where this monkey was translocated or introduced in the 1970s and 1980s. It appears that only one of these releases was successful. A total of 67 animals were caught and translocated or introduced (including four that died during the process). Thirteen to 20 years later, 62–70 red colobus were located at the three sites; i. e. there had been no net gain in colobus numbers as a result of the translocations and introduction. One attempt apparently failed because of insufficient habitat, and another perhaps because of insufficient numbers ofcolobus or an imbalance in the age and sex composition of animals released. The one successful translocation involved moving a fairly large number of monkeys (36) into a forest with a relatively high diversity of tree species. In light of these findings, the authors recommend that far more attention be given to protecting the monkeys and their habitat where they currently exist, rather than spend time and money on translocations that are as likely to fail as to succeed.
Hornbill abundance in unlogged forest, selectively logged forest and a forest plantation in Arunachal Pradesh, India
Authors: Datta Aparajita
Published: November 2003

The responses of hornbills to selective logging were determined by comparing their diversity and abundance in five habitats classified according to logging history. Relative abundance of three hornbill species was compared along trails in recently logged forest, 20–25-year-old logged forest, unlogged primary forest, a relatively disturbed primary forest and a plantation in Pakhui Wildlife Sanctuary and adjoining reserve forests in western Arunachal Pradesh. The species recorded were the Oriental pied hornbill Anthracoceros albirostris, wreathed hornbill Aceros undulatus and great hornbill Buceros bicornis. The great hornbill was the most common species overall and its abundance varied across habitats, being highest in unlogged forest. The Oriental pied hornbill, which was recorded in only two habitats, seemed to show a distinct habitat preference for secondary growth, rivermargin forests. Wreathed hornbill abundance did not differ between habitats. Differences in species abundance probably reflect aspects of their ecology, such as degree of territoriality, diet and movement patterns, and differential vulnerability to hunting and disturbance. Great hornbill abundance was correlated with large tree density (GBH ≥ 150 cm) and basal area characteristic of unlogged primary forests, while Oriental pied hornbill abundance was negatively correlated with tall forest, indicating its greater numbers in low-stature river-margin forest. Wreathed hornbill abundance was not correlated with any vegetation variable, which is probably related to its reported nomadic movements in search of fruit patches. Hornbill abundance was not correlated with densities of potential food and nest tree species. Although hornbill abundance was not correlated with fig tree density, this was probably because areas where relative fig tree densities were lower often contained a few large fruiting figs. Because hornbills are large mobile birds, they can find resources such as fruiting figs even in otherwise unsuitable habitat.
Use and conservation of Cracidae (Aves: Galliformes) in the Peruvian Amazon
Authors: Begazo Alfredo J. , Bodmer Richard E.
Published: November 2003

Four species of the avian family Cracidae were studied in the Pacaya-Samiria National Reserve in north-eastern Peru. These large-bodied birds are an important source of protein for local communities on the periphery of the reserve. An estimated 425 kg of Cracidae biomass were harvested over a 1-year period by three communities. Pipile cumanensis was the most frequently hunted bird, both in terms of individuals hunted and biomass extracted. Mitu tuberosa and Penelope jaquacu also made up a substantial amount of the biomass extracted, but were hunted less frequently. Densities of all species of Cracidae within 5 km of the villages were substantially lower than in the interior of the reserve. Our results suggest that M. tuberosa and P. cumanensis are overharvested and P. jaquacu and Ortalis guttata are harvested within the maximum estimated sustainable levels. In this study hunting grounds were along waterways and adjacent to protected populations, which created a source-sink arrangement. If sink areas are overhunted, the unhunted populations inland of the waterways could be acting as source populations that replenish overhunted areas.
Circumstantial evidence for the presence of monk seals in the West Indies
Authors: Boyd I. L. , Stanfield M. P.
Published: November 2003

Based on interviews with 93 fishermen in northern Haiti and Jamaica during 1997 an assessment was made of the likelihood that monk seals survive in this region of the West Indies. Fishermen were asked to select marine species known to them from randomly arranged pictures: 22.6 per cent (n = 21) selected monk seals. This number was significantly (P < 0.001) greater than the number who selected control species (walrus, harbour seal, and sea-lion) that they were unlikely to have observed. However, it was not significantly different (n = 19, P > 0.1) from the number who selected manatees, which are known to occur in the region in small numbers. More than 95 per cent of respondents also identified species that are known to occur commonly in the region. Further questioning of the 21 respondents who selected monk seals suggested that 16 (78 per cent) of them had seen at least one in the past 1–2 years. Those fishermen that were able to provide further descriptions gave information about size and colour that was consistent with many of these seals being monk seals. It is possible that the Caribbean monk seal is not extinct.
Ivory in Kathmandu
Authors: Martin Esmond Bradley
Published: November 2003

Elephant ivory is still on sale in Kathmandu, in Nepal, despite the fact that this transgresses the country's legislation. In a recent survey of 184 shops frequented by tourists 1454 ivory items were found for sale. Trade in ivory is at a vey low level, but dealers are still importing ivory. The Forest officers and police need to be motivated to confiscate the ivory and take the offenders to court. Without fully implementing Nepal's 25-year-old National Parks and Wildlife Conservation Act, the authorities are indirectly encouraging people to flout the restrictions.
Characterization of a secreted antigen of Onchocerca volvulus with host‐protective potential
Authors: JENKINS R.E. , TAYLOR M.J. , GILVARY N. , BIANCO A.E.
Published: November 2003

A cDNA designated MOv2 was isolated from an Onchocerca volvulus library on the basis of its product's recognition by an antiserum raised against the infective stage. Immunogold electron microscopy revealed a high density of antigenic sites associated with the annulae of the L3 cuticle and with the uterine wall of the adult female: a general, low density of labell ing occurred in all developmental forms. Western blotting confirmed the presence of the antigen throughout the life cycle and the existence of an immunologically cross‐reactive homologue in the related filaria, Acanthocheilonema viteae. The antigen was shown to be secreted by infective larvae and adult females of A. viteae. Sequence comparisons revealed two homologues of MOv2 (Ov‐20, Ov‐9) which had been selected independently by other laboratories on the basis of their specific recognition by human onchocerciasis infection sera. The IgG antibody response against MOv2 in cattle experimentally infected with O. lienalis revealed the induction of a response during the prepatent period that was strongly boosted at the onset of patency. However, only a proportion of infected cattle responded with a detectable level of anti‐MOv2 antibodies. The appearance of MOv2 in larval cuticle and secretions prompted us to evaluate it as a candidate molecule for prophylactic immunization. Trials performed in the A. viteae/Mongolian jird model of filariasis revealed that recombinant MOv2 induced a host‐protective response, reducing worm recoveries by 36–55% following a challenge infection.
Reactive oxygen intermediates from eosinophils in mice infected with Hymenolepis nana
Authors: Niwa Atsuko , Miyazato Takashi
Published: November 2003

A large number of eosinophils were recruited to the intestinal villi after infection with Hymenolepis nana. Eosinophil numbers were increased more rapidly in challenged mice than in primary infected mice. Local intestinal eosinophils from challenged mice showed more extracellular oxygen radical release, as assessed by histochemical mothods using nitro blue tetrazolium, accompanied with tissue injury and larval degradation. Intestinal eosinophils isolated from the lamina propria induced specific oxygen radical generation in response to H. nana oncosphere extract as measured by luminol‐dependent chemiluminescence. This response was stronger in challenged mice than in primary infected mice. Radical generation from uninfected mice was negligible. Lipid peroxidation in the small intestine, as measured by formation of malondialdehyde, was increased during H. nana challenge infection, the peak activity coinciding with the elimination of challenge larvae. Continuous administration of a NADPH oxidase inhibitor to sensitized mice interfered with the degeneration of challenge larvae. These results suggest that intestinal eosinophils may be the major contributor to oxygen radical production in response to H. nana and that reactive oxygen species may play a part of effector molecule in the resistance to reinfection with H. nana
Workshop on a detailed characterization of Trichinella spiralis antigens: a platform for future studies on antigens and antibodies to this parasite
Authors: ORTEGA‐PIERRES M.G. , YEPEZ‐MULIA L. , HOMAN W. , .GAMBLE H.R , LIM P.L. , TAKAHASHI Y. , WASSOM D.L. , APPLETON J.A.
Published: November 2003

In order to characterize immunodominant components of T. spiralis a workshop was organized. In this the reactivity of monoclonal and polyclonal antibodies, provided by different research groups, towards total extracts from adult, new born larvae and muscle larvae as well as to excretory/secretory components of muscle larvae were tested by ELISA, Western blot and immunoprecipitation assays. As a result of this workshop T. spiralis ML antigens have been classified into eight groups (TSL‐1–TSL‐8) according to their recognition by monoclonal and polyclonal antibodies. Among them, TSL‐1 antigens have been the most extensively characterized both biochemically and immunologically. These antigens are stage specific, originate in the muscle stichosome and are abundant in both E/S and on the larval cuticular surface. The TSL‐1 antigens share an immunodominant carbohydrate epitope (tyvelose), which is unique for Trichinella and is not associated with phosphorylcholine. The data collected in this workshop has allowed both the unification of the nomenclature for T. spiralis antigens and their biochemical characterization. It also has provided a platform for further studies on the characterization of other T. spiralis antigens and indeed for other Trichinella species.
A role for Tumour Necrosis Factor‐α in acute lymphatic filariasis
Authors: Das Bidyut K. , Sahoo Prakash K. , Ravindran B.
Published: November 2003

A spectrum of clinical manifestations is a feature of human lymphatic filariasis. The acute disease is characterized by periodic and self limiting episodes of adenolymphangitis, fever and associated constitutional symptoms, while the chronic disease includes long lasting manifestations such as lymphoedema and/or hydrocoele. The microfilariae carriers are generally free of clinical symptoms. In the present study circulating Tumour Necrosis Factor (TNF‐α) was measured in human bancroftian filariasis with different clinical manifestations. Significantly elevated levels were observed only in patients with acute disease and not in microfilariae carriers or in patients with chronic manifestations. A detailed analysis of the acute cases indicated an absence of correlation between TNF‐α levels and duration of the episodes. However, a significant positive correlation was observed between the severity of the disease and the TNF‐α levels. About 85% of the acute cases with severe manifestations showed raised levels of TNF‐α while only 6.5% of mild cases showed such levels. Manifestation of fever was also significantly associated with higher levels of TNF‐α—while 80% of acute cases with fever had significant levels only 24% of acute cases without fever had high levels of TNF‐α. Based on these observations we propose a mediatory role for TNF‐α in acute filariasis and the possible use of TNF‐α inhibitors for clinical management of the disease.
Experimental model for human intestinal microsporidiosis in interferon gamma receptor knockout mice infected by Encephalitozoon intestinalis
Authors: OMBROUCK Abderrahim , GNERAGBE Tieminé , CHARLOTTE Frédérick , RÉNIA Laurent , DESPORTES‐LIVAGE Isabelle , MAZIER Dominique
Published: November 2003

Interferon gamma receptor knockout mice developed a chronic infection when inoculated with spores of Encephalitozoon intestinalis which is a cause of intestinal microsporidiosis in AIDS patients. The infection was evaluated by enumeration of the spores of the parasite shed in the stools, histological examination and follow up over a period of six months. A dose‐response was demonstrated since higher numbers of spores were excreted and more infection sites were found in mice which were given an increased quantity of parasites. In infected wild type mice, the number of excreted spores decreased until day 16 post‐inoculation, then spores were detected sporadically in low numbers. These data confirmed the role of IFN‐γ in the control of E. intestinalis infection. The infection was not lethal suggesting that other factors are involved in regulation of the parasite infection. This model, with the long survival time of the animals together with the measurable quantity of spores shed in the stools will be useful for testing potential therapeutical agents.
Nitric oxide synthase activity in malaria‐infected mice
Authors: JONES I.W. , THOMSEN L.L. , KNOWLES R. , GUTTERIDGE W.E. , BUTCHER G.A. , SINDEN R.E.
Published: November 2003

Nitric oxide (NO) is implicated in a variety of major cellular functions including defence from invasion by microbical pathogens. Evidence has been presented suggesting that it is an important mediator of protection in the early non‐specific responses to malaria in mice infected with Plasmodium chabaudi(Taylor‐Robinson et al. 1993). Other data from in vitro studies on the asexual stages of human parasite Plasmodium falciparum indicated that while nitric oxide itself may not be inhibitory to parasite development, its downstream products do have some anti‐plasmodial activity (Rockett et al. 1991) and these could be generated by macrophages (Gyan et al. 1994 ). Similarly, the sexual phases of both rodent (Motard et al. 1993) and human malaria (Naotunne et al. 1993) are reportedly susceptible to the toxic effects mediated by nitric oxide generated by blood leucocytes in the course of transmission to the mosquito vector.
Influence of parasite presence on the immunologic profile of peripheral blood mononuclear cells from chagasic patients after specific drug therapy
Authors: DUTRA WALDEREZ O. , PROFETA da LUZ ZÉLIA MARIA , CANÇADO JOAQUIM ROMEU , PEREIRA MARIA ELIZABETH , BRÍGIDO‐NUNES ROSA MARIA , GALVÃO LÚCIA M. C. , COLLEY DANIEL G. , BRENER ZIGMAN , GAZZINELLI GIOVANNI , CARVALHO‐PARRA JUÇARA F.
Published: November 2003

The aim of this study is to evaluate the effects of parasite clearance on the immunological profile of peripheral blood mononuclear cells (PBMC) from chagasic patients submitted to specific drug therapy. PBMC were examined by flow cytometry and proliferative responsiveness to Trypanosoma cruzi‐related stimuli. Three groups of patients were studied: not treated (NT), treated not cured (TNC) and cured (C). All data were compared to values from uninfected individuals (NI). NT displayed a lower percentage of CD3+ cells as compared to NI, while TNC and C had mean values that were between those from NI and NT. Infected patients had double the percent of CD3+ HLA‐DR+ cells, independent of the efficacy of the treatment. Thus, absence of circulating parasites did not reduce T cell activation in Chagas' disease. NT displayed a higher percentage of CD5+ B cells as compared to NI, while TNC and C had mean values between those from NI and NT. In contrast to the phenotypic data, the in vitro mean proliferative responses to parasite‐related stimuli of PBMC from C were reduced to the low mean levels observed in NI. These striking differences were statistically different from the high responses seen in NT and TNC. Our data suggest that proliferative responses of PBMC from C reflect immunological changes due elimination of parasite. However, successful treatment did not alter the levels of peripheral T cell activation.
Stage‐specific expression of surface molecules by the larval stages of Haemonchus contortus
Authors: RALEIGH JEANETTE M. , BRANDON MAL R. , MEEUSEN ELS
Published: November 2003

Three monoclonal antibodies, Hc2, Hc22 and Hc6, were produced against a surface extract of L3 Haemonchus contortus and screened against both free living and parasitic stages of the parasite. Hc2 and Hc22 were of IgG2c isotype and their target epitopes were insensitive to periodate treatment. Hc6 was of IgM isotype and its reactivity was sensitive to periodate treatment of the antigen, suggesting that Hc6 is specific for a carbohydrate epitope. Western blotting of larval extracts and staining of live worms demonstrated that Hc2 was specific for the surface of second stage larvae and that the epitope was still present on the protective sheath of third stage larvae but absent from the L3 cuticle itself. Hc22 was found to be specific for a 70–90 kDa antigen on the surface of third stage infective larvae and cross reacted with a higher molecular weight species present on the surface of third stage Teladorsagia circumcincta. Hc6 showed strong binding to three high molecular weight proteins on immunoblots of third stage larvae only, but in contrast to Hc2 and Hc22, showed no binding to the surface of live larvae. These studies demonstrate unique expression patterns of stage specific antigens on the surface of free living and parasitic H. contortus larvae.
Is the induction of apoptosis the mechanism of the protective effects of TNFα in helminth infection?
Authors: GARSIDE PAUL , SANDS WILIAM A. , KUSEL JOHN R. , HAGAN PAUL
Published: November 2003

Tumour necrosis factorα has been implicated in protective immune responses to a number of parasitic helminths. However, the final effector mechanisms resulting in death or expulsion of the parasite are unclear. Here we suggest that, by employing phylogenetically conserved mechanisms, the mammalian immune system is able to interfere with helminth development directly and that the protective effects of TNFα in helminth infections may operate via the induction of parasite apoptosis.
Age‐related antibody profiles in Schistosoma haematobium infections in a rural community in Zimbabwe
Authors: NDHLOVU P. , CADMAN H. , VENNERVALD B.J. , CHRISTENSEN N.Ø. , CHIDIMU M. , CHANDIWANA S.K.
Published: November 2003

Antibody responses to soluble Schistosoma haematobium egg (SEA) and worm (SWA) antigens in a rural Zimbabwean study population were examined by ELISA. One hundred and sixteen S. haematobium infected and 124 non‐infected individuals representing individuals greater than five years old, were included. Non‐endemic control sera were obtained from a schistosomiasis non‐endemic part of Zimbabwe and from Norwegian blood donors. A possible association between IgE antibody responses and resistance to S. haematobium infection was indicated by a negative correlation between IgE anti‐SEA levels and intensity of S. haematobium infection, and by a positive correlation between IgE responses to SEA and SWA and age. Similarly, an association between IgA and anti‐SWA and resistance to S. haematobium was suggested by a negative correlation to intensity of infection and a positive correlation with age. A probably association between IgM and IgG4 with susceptibility to S. haematobium infection was described; intensity of S. haematobium infection correlated positively with IgG, IgG4 and IgM responses to SEA and with IgG4 and IgM responses to SWA, also age correlated negatively with IgG4 and IgM responses to SEA and with IgG4 responses to SWA. These findings support the concept of IgG4 and IgM as blocking antibodies. Significant positive correlations between antibody responses to SEA and SWA suggests cross‐reactivity between eggs and adult worms. In addition, the recognition by IgE and IgG4 of the same schistosomulum antigens in immunoblotting suggests competition for the same antigens.
Recombinant mouse IL‐6 boosts specific serum anti‐plasmodial IgG subtype titres and suppresses parasitaemia in Plasmodium chabaudi chabaudi infection
Authors: AKANMORI BARTHOLOMEW DICKY , KAWAI SATORU , SUZUKI MAMORU
Published: November 2003

C57BL/6 mice which were treated with recombinant mouse interleukin‐6 (rmIL‐6), 75 ng in 0.2 ml saline, i.p., 24 h before inoculation with Plasmodium chabaudi chabaudi and on days one, two and three could not control the primary acute parasitaemia but were able to suppress secondary parasitaemia significantly, peak of 3% and to reduce parasitaemia to subpatent levels within three weeks. Control C57BL/6 mice, which received saline injections only, developed two identical peaks of parasitaemia of at least 21% each, typical of a primary P. chabaudi chabaudi infection and cleared parasitaemia by day 28 post‐inoculation. Serum levels of IL‐6 measured in the first week by enzyme‐linked immunosorbent assay were significantly higher (two‐fold) in recipients compared to control mice. Anti‐plasmodial IgG1, 2a and 2b titres were four to 16 times higher in rmIL‐6 recipients than in the control mice. Reduction of parasitaemia to subpatency during the secondary phase of P. chabaudi chabaudi infection in C57BL/6 mice is primarily antibody‐mediated and rmIL‐6 accelerates this process by boosting the levels of the required specific anti‐plasmodial IgG subclasses of antibodies.
Comparative studies on immune responses to infection in susceptible B10.BR mice infected with different strains of the murine nematode parasite Trichuris muris
Authors: KOYAMA KOICHI , ITO YOICHI
Published: November 2003

A comparison of immune responses to infection between groups of B10.BR mice infected with different strains of T. muris, S strain (isolated in Sobreda, Portugal), E strain (isolated in Edinburgh), and E‐J strain (originally E strain, which has been maintained in our laboratory, Japan), was performed. In mice infected with E and E‐J strains, most of the worms were expelled by day 32 after infection, though the expulsion was faster in E‐J strain‐infected mice. In contrast, no expulsion was observed in S strain‐infected mice by day 32 and egg production occurred on day 32. IL‐4 production occurred in concanavalin A (Con‐A)‐stimulated mesenteric lymph node cells (MLNC) from B10.BR mice infected with E and E‐J strains, whereas no IL‐4 production was observed in S strain‐infected mice. IL‐4 production did not occur in normal mice. In comparison with normal mice, high levels of IFN‐γ production by Con A‐stimulated MLNC were detected in mice infected with every strain of T. muris. IFN‐γ production in S strain‐infected mice was greater, occurred earlier and was more persistent than in mice infected with E and E‐J strains. IgG1 and IgG2a antibodies to T. muris excretory/secretory antigens were observed in B10.BR mice infected with every strain of T. muris. Antibody production showed similar kinetics. These differences in the expulsion kinetics and IL‐4 production in B10.BR mice infected with S, E, and E‐J strains suggest the involvement of IL‐4 in protection against T. muris infection, and confirm the previous conclusion by Else et al. (1994).
In situ characterization of leucocyte subpopulations after infection with Eimeria tenella in chickens
Authors: VERVELDE LONNEKE , VERMEULEN ARNO N. , JEURISSEN SUZAN H.M.
Published: November 2003

We characterized the leucocyte subpopulations after infection with Eimeria tenella in both naive and immune chickens. Immunocytochemical staining was used to characterize the cells in situ, so that the interaction between host and parasite could be studied. More leucocytes were detected in the lamina propria of immune chickens, and leucocytes infiltrated the ceca more rapidly than in naive chickens, but the infiltration was less pronounced than in naive chickens. In naive chickens, most infiltrated leucocytes were macrophages and T cells. Two days after inoculation the number of CD4+ cells had increased greatly. In immune chickens, mainly T cells (CD4+ and CD8+) infiltrated the lamina propria, and in contrast to naive chickens, the number of CD8+ cells exceeded the number of CD4+ cells. Furthermore, we characterized which cells contained a parasite and which cells were detected next to the parasites, because these cells are probably involved in the arrested development of the parasites. In naive chickens, sporozoites were significantly more often located within or next to macrophages than in immune chickens. In immune chickens, sporozoites were significantly more often located within or next to CD3+, CD8+, and TCR2+ cells. In conclusion, the marked increase of CD4+ cells after primary infection suggests that these cells are involved in the induction of the immune response, whereas the increase of CD8+ cells after challenge infection suggests that these cells act as effector cells.
IL‐12 eliminates the Th‐2 dependent protective immune response of mice to larval Strongyloides stercoralis
Authors: ROTMAN H.L. , SCHNYDER‐CANDRIAN S. , SCOTT P. , NOLAN T.J. , SCHAD G.A. , ABRAHAM D.
Published: November 2003

The goal of the present study was to determine if immune‐mediated killing of S. stercoralis L3 in mice could be modulated by shifting from a Th‐2 to a Th‐1 type immune response. L3 killing in immunized mice was ablated in CD4+ T cell‐depleted animals, but not in CD8+ T cell‐depleted or β2‐microglobulin‐deficient mice. Treatment of immunized mice with IL‐4 or IL‐5 neutralizing MoAb significantly reduced the protective effects of vaccination against S. stercoralis, while protective immunity was unimpaired in IFN‐γ knockout mice. Recombinant IL‐12 was administered to infected mice to switch the immune response from a Th‐2 to a Th‐1 type response. Protective immunity was ablated in immunized mice that received IL‐12 therapy. Eosinophil numbers, eosinophil peroxidase levels, and parasite‐specific IgG1 levels were lowered in IL‐12 treated immunized animals, and parasite‐specific IgG2a levels were increased in these animals. The data indicate that eosinophils are important as mediators of larval killing, and that the establishment of Th‐2 type immunity results in killing of infective S. stercoralis L3, while a shift to Th‐1 type immunity abrogates protective responses.
Evaluation of recombinant protein r140, a polypeptide segment of tegumental glycoprotein Sm25, as a defined antigen vaccine against Schistosoma mansoni
Authors: SURI PARMJEET K. , GOLDBERG MIRIAM , MADIKIZELA MZWANDILE , PETZKE MARY M. , BUNGIRO RICHARD D. , DAVIES STEPHEN J. , CHAKRABORTY BHASKAR , NGUYEN KHUONG B. , McCRAY JOSEPH W. , KNOPF PAUL M.
Published: November 2003

To investigate the role of tegumental glycoprotein Sm25 in protective immunity against schistosomiasis, codons 43‐182 of its gene (GP22) were amplified by PCR and cloned in the pET 15b bacterial expression system. Recombinant protein r140 was inducibly expressed in the presence of rifampicin and purified by Ni‐affinity chromatography. In different vaccination trials, Balb/c mice and Fischer rats repeatedly immunized with r140 in combination with one of several adjuvants (alum, cholera toxin or complexed into proteosomes) produced high titre anti‐r140 responses. These antibodies detected an N‐glycanase sensitive, 25 kDa antigen in a detergent solubilized worm fraction using Western immunoblotting. The choice of adjuvant affected the isotype distribution of the specific anti‐r140 antibodies. Despite the presence of high antibody titres and isotypes which have been shown to correlate with protective immunity, protection against subsequent cercarial challenge was not observed. In addition, no appreciable effects on worm sex ratios or liver egg yields were detected in mice. Studies involving biotin labelling of membrane proteins in live worms showed that the majority of anti‐r140 reactive molecules present in adult schistosomes are biotinylated after permeabilization of the parasite surface. Several possibilities to account for the lack of protective immunity are analysed.
Analysis of cytokine and specific antibody profiles in hydatid patients with primary infection and relapse of disease
Authors: HERNÁNDEZ‐POMI ANA , BORRAS‐SALVADOR RAFAEL , MIR‐GISBERT AMPARO
Published: November 2003

We studied in vitro cytokine production by peripheral blood mononuclear cells (PBMC) from patients with primary and recurrent hydatid disease when cells were incubated with mitogen (PHA) and antigen from hydatid cyst fluid (HCFAg); levels of specific IgE, IgG4 and eosinophil counts were also measured in sera. When specifically stimulated, PBMC from patients produced higher levels of IL‐2 (P < 0.02), IFN‐γ (P < 0.0028) and IL‐5 (P < 0.01) than those from uninfected donors, whereas IL‐10 levels were comparable. Notably, IL‐5 was also produced in higher levels (P < 0.01) by PBMC from patients when incubated with PHA. The IL‐5:IFN‐γ ratio was significantly greater (P < 0.02) when measured in response to specific stimulation than it was for PHA‐stimulated cultures. These cytokine data suggest a bias towards a Th2‐response which is in agreement with the high levels of IgG4 and IgE observed. The polarized response appears to be related to clinical status, as differences between patients with primary infection and those with relapse of disease were demonstrated, with significantly higher levels of IgE (P < 0.003), IgG4 (P < 0.04) titres and eosinophil counts (P < 0.04) in the latter; in addition a tendency to an increased production of IL‐5 buy lower IFN‐γ was also observed in this group. These results merit further study as they are suggestive of a putative role of Th2‐like responses in susceptibility to reinfection by E. granulosus.
Characterization of phenotype related responsiveness of peripheral blood lymphocytes from Eimeria tenella infected chickens
Authors: BREED DOMINIQUE G.J. , SCHETTERS THEO P.M. , VERHOEVEN NICOLE A.P. , VERMEULEN ARNO N.
Published: November 2003

We have previously shown that the proportion of CD8‐expressing T cells (CD8bright+ and CD4+ CD8dim+ cells) in the peripheral blood of chickens increases around 8 days after a primary infection with Eimeria tenella oocysts. The increase in the CD8+ eight cells coincides with enhanced responses after in vitro stimulation with parasite antigen. In the study described here, the responsiveness of these day 8 PBL was further characterized by determining their capacity to proliferate and to produce cytokine (IFN‐γ) upon stimulation with E. tenella sporozoite antigen, or non‐specific stimuli like T cell growth factor (TCGF) and anti‐CD3 monoclonal antibody (MoAb). Comparing the responsiveness of infected responder (day 8) and control chickens, non‐specific triggering induced cytokine production in cells from infected animals and proliferation in cells from control animals. When triggered with E. tenella sporozoite antigen, lymphocytes from infected chickens responded with proliferation and cytokine production, in contrast to lymphocytes from control animals that did not respond. The phenotype of the lymphocytes involved in the parasite‐specific proliferation and cytokine production, was characterized in a blocking assay using MoAb directed against the CD4 or CD8 molecule. The results suggest that CD8bright+ as well as CD4+ (CD4+ CD8dim+ and possible CD4+, single positive) lymphocytes are responsible for the IFN‐γ production measured after stimulation with parasite antigen, whereas the specific proliferative response appears to be caused by CD4+ (CD4+ CD8dim+ and possibly CD4+, single positive) lymphocytes. We speculate that the CD8bright+ cells, present in the circulation around 8 days after a primary E. tenella infection, act as effector cells in protective immune responses, whereas CD4+ cells play an important helper function in these responses.
Circulating Tumour Necrosis Factor α is not involved in the development of cerebral malaria in Plasmodium berghei‐infected C57Bl mice
Authors: HERMSEN C.C. , CROMMERT J.V.D. , FREDRIX H. , SAUERWEIN R.W. , ELING W.M.C.
Published: November 2003

Administation of neutralizing anti‐TNFα antibodies did not prevent Plasmodium berghei induced cerebral malaria (CM) in C57Bl/6 mice, when given at different dosages and time intervals. Elevated concentrations of immunoreactive TNFα were found in the circulation but no bioactive TNFα could be detected in mice developing CM. Furthermore, elevated TNFα receptor concentrations were measured in the plasma of mice developing CM. Plasma of these mice neutralized bioactive recombinant‐mouse TNFα indicating that a part of the plasma TNFα‐receptors were not complexed with TNFα. The apparent absence of free TNFα probably explains why treatment with antibodies against TNFα failed to prevent development of CM.