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Wrestling with issues of racism and colonization in the classroom requires significant nuance from dominantly positioned educators. In this article, we weave together a narrative unpacking of an uncomfortable experience in a graduate level class with an exploration of relevant theoretical literature. Our reflection on practice takes up the possibilities for anti-oppressive education to engage with the partial knowledge of educators and students. Ultimately, engaging in a pedagogy of discomfort is necessary to unsettle dominantly positioned educators and students and enable a move towards bearing witness to the unequal realities of Canadian society. In order to begin to enter more deeply into relationships of accountability between non-Indigenous and Indigenous peoples, teaching moments such as these are inevitable, if not required. Keywords: anti-oppressive education, discomfort, colonialism, partial knowledge, Indigenous futurity

The global health community has targeted the elimination of neglected tropical diseases (NTDs) including soil-transmitted helminthiasis by 2030. The elimination strategy has not changed from that of control using regular mass drug administration (MDA) with albendazole, WASH and education. Already doubts have been expressed about this achievement, principally because drugs do not interrupt transmission. We report here the findings of a cohort study aimed to identify host modifiable and environmental factors associated with hookworm infection and reinfection in rural communities in Kintampo North Municipality, Ghana. Faecal samples of 564 consented participants were screened for intestinal parasites at baseline, 9 months and 24 months using the Kato-Katz method. At each time point, positive cases were treated with a single dose of albendazole (400 mg) and their samples were again screened 10-14 days post-treatment to record treatment failures. The hookworm prevalence at the three-time points was 16.7%, 9.22% and 5.3% respectively, whilst treatment failure rates were 17.25%, 29.03% and 40.9% respectively. The intensities of hookworm infection (in eggs per gram) at the time points were 138.3, 40.5 and 135, which showed a likely association with wet and dry seasons. We posit that the very low intensity of hookworm infections in humans during the dry season offers a window of opportunity for any intervention that could drastically reduce the community worm burden before the rainy season.

Microbes play an important role in human gut homeostasis, metabolic, immunologic and physiopathology of the body. A longitudinal study conducted during 2018–2021 in the Kintampo North Municipality in Ghana demonstrated low hookworm infection cure rates following treatment with a single dose of 400 mg albendazole in some communities. To investigate associations between hookworm infection and the gut microbiome, we examined faecal samples from consented participants who were either cured or remained infected after treatment. At each time point, fecal samples were collected prior to and 10–14 days after albendazole treatment of those who were infected. We used 16S rRNA amplicon sequencing of DNA extracted from stool samples to investigate the composition and biodiversity of the gut microbiota and to identify potential microbial biomarkers associated with treatment outcomes. Results of the study showed an association between hookworm infection and increased species richness. It also demonstrated a significant variation in microbiota composition at 10–14 days following single-dose albendazole treatment. Individuals cured of hookworm infection after treatment showed a significant reduction in microbiota composition when compared to their pre-treatment state (ANOSIM; p = 0.02), whilst individuals who failed to clear the infection showed no significant change in microbiota composition (ANOSIM; p = 0.35). Both uninfected individuals and individuals who were successfully treated were similar in terms of microbial composition and structure. We also found that the abundance of Clostridia spp. was increased in positive individuals before treatment as well as in those who were not cured. Predictive functional profiling revealed the enrichment of two pyruvate ferredoxin oxidoreductase subunit pathways in individuals who remained infected after treatment (p Clostridia spp. This study suggests a relationship between human gut microbiome dysbiosis and albendazole therapy outcomes of hookworm infection. Future studies will further characterize specific biomarkers identified within this study to establish their potential for assessment of pharmacological responses to anthelminthic therapies, as well as explore the possibility of using probiotic supplementation as an adjunct treatment to increase albendazole effectiveness against hookworm.

Community Health Workers (CHWs) in low and middle income countries (LMICs) provide invaluable health resources to their community members. Best practices for developing and sustaining CHW training programs in LMICs have yet to be defined using rigorous standards and measures of effectiveness. With the expansion of digital health to LMICs, few studies have evaluated the role of participatory methodologies combined with the use of mobile health (mHealth) for CHW training program development. We completed a three-year prospective observational study aligned with the development of a community-based participatory CHW training program in Northern Uganda. Twenty-five CHWs were initially trained using a community participatory training methodology combined with mHealth and a train-the-trainer model. Medical skill competency exams were evaluated after the initial training and annually thereafter to assess retention with use of mHealth. After three years, CHWs who advanced to trainer status redeveloped all program materials using a mHealth application and trained a new cohort of 25 CHWs. Implementation of this methodology coupled with longitudinal mHealth training demonstrated an improvement in medical skills over three years among the original cohort of CHWs. Further, we found that the train-the-trainer model with mHealth was highly effective, as the new cohort of 25 CHWs trained by the original CHWs exhibited higher scores when tested on medical skill competencies. The combination of mHealth and participatory methodologies can facilitate the sustainability of CHW training programs in LMIC. Further investigations should focus on comparing specific mHealth modalities for training and clinical outcomes using similar combined methodologies.

A Review of Silencing Ivan Illich: A Foucauldian Analysis of Educational Exclusion by David Gabbard

Hookworm infection (Necator americanus and Ancylostoma spp) causes significant morbidity in resource-limited countries. Dog and pig ownership is associated with human infection, although the mechanism through which animals increase risk remains unknown. We first confirmed this association in Kintampo North, Ghana, using a retrospective analysis and serology, followed by a prospective molecular study of animal faeces. As a proxy of exposure to dog faeces, we analysed immunoreactivity of human serum to the zoonotic nematode Toxocara canis. Anti-Toxocara antibodies were present in 62% of samples (n = 89), and reactivity was associated with dog ownership. A subsequent prospective study revealed that 43% of dog and 56% of pig faecal samples contained hookworm eggs by microscopy. PCR analysis confirmed the presence of N. americanus DNA in 47% of samples from dogs and 56% pig samples. Nematode larvae were successfully cultured from samples collected from 36 dogs and seven pigs. These results demonstrate that dogs and pigs have a likely role in the transmission of N. americanus in endemic communities.

Hookworm infection causes anemia, malnutrition, and growth delay, especially in children living in sub-Saharan Africa. The World Health Organization recommends periodic mass drug administration (MDA) of anthelminthics to school-age children (SAC) as a means of reducing morbidity. Recently, questions have been raised about the effectiveness of MDA as a global control strategy for hookworms and other soil-transmitted helminths (STHs). Genomic DNA was extracted from Necator americanus hookworm eggs isolated from SAC enrolled in a cross-sectional study of STH epidemiology and deworming response in Kintampo North Municipality, Ghana. A polymerase chain reaction (PCR) assay was then used to identify single-nucleotide polymorphisms (SNPs) associated with benzimidazole resistance within the N. americanus β-tubulin gene. Both F167Y and F200Y resistance-associated SNPs were detected in hookworm samples from infected study subjects. Furthermore, the ratios of resistant to wild-type SNP at these two loci were increased in posttreatment samples from subjects who were not cured by albendazole, suggesting that deworming drug exposure may enrich resistance-associated mutations. A previously unreported association between F200Y and a third resistance-associated SNP, E198A, was identified by sequencing of F200Y amplicons. These data confirm that markers of benzimidazole resistance are circulating among hookworms in central Ghana, with unknown potential to impact the effectiveness and sustainability of chemotherapeutic approaches to disease transmission and control.

Individuals with acute malaria infection generated high levels of antibodies that cross-react with the SARS-CoV-2 Spike protein. Cross-reactive antibodies specifically recognized the sialic acid moiety on N-linked glycans of the Spike protein and do not neutralize in vitro SARS-CoV-2. Sero-surveillance is critical for monitoring and projecting disease burden and risk during the pandemic; however, routine use of Spike protein-based assays may overestimate SARS-CoV-2 exposure and population-level immunity in malaria-endemic countries.

An estimated 4.7 billion people live in regions exposed to soil-transmitted helminths, intestinal parasites that have significant impacts on the health of women smallholder farmers. The goal of this trial was to determine whether treatment with albendazole impacts the work capacity of these farmers. This is a prospective double-blind, randomized effectiveness trial. Participants (N = 250) were randomly selected from safe motherhood groups in the Democratic Republic of Congo. Prevalence/intensity of hookworm infection, hemoglobin, and demographics was obtained. At study (Time = 0), participants were randomized into treatment (albendazole 400 mg) and placebo (similar placebo tablet) groups. A step test was administered as a proxy metric for work capacity. Work capacity was defined as ∆heart rate before and after 3 minutes of step testing, in beats per minute. At study (time = 7 months), the step test was repeated and work capacity remeasured. The ∆work capacity (time = 0 minus time = 7 months) was the primary outcome. Investigators/field assistants were blinded to who was enrolled in groups, hookworm status, and step test results. Regression showed highly significant interactive effects of hookworm status and treatment group relative to ∆work capacity after controlling for resting pulse rate and age (P < 0.002). Estimated marginal means for work capacity (WC) for each of four groups (hookworm positive plus placebo, hookworm positive plus treatment, hookworm negative plus placebo, and hookworm negative plus treatment) showed women who were hookworm positive and received treatment decreased heart rate by 9.744 (95% confidence interval [CI]: 6.42, 13.07) beats per minute (increased WC), whereas women who were hookworm positive and received placebo saw a nonsignificant decrease of 0.034 (95% CI: −3.16, 3.84) beats per minute. Treatment with albendazole was associated with improved aerobic work capacity posttreatment. Given modest costs of drug distributions, risk benefits of periodic deworming warrants further study in larger controlled trials.

AIM The aim of the study was to define social determinants, causes and trends in child mortality from 1990 to 2013 in Pakistan. Understanding social determinants, causes and temporal trends in child mortality can inform strategies aimed at improving child health in low and middle income countries. METHODS We characterised temporal trends and social determinants of child mortality in Pakistan using national demographic health survey data (1990-1991, 2006-2007 and 2012-2013). We analysed national data to generate regional estimates of health programme effectiveness. RESULTS The annual rates of reduction for child mortality between 1990 and 2013 were estimated as follows: neonatal (-0.33% per annum), post-neonatal (3.13% per annum), infant (0.9% per annum), child (2.47% per annum) and under 5 (1.19% per annum). Bivariate analyses of 2013 data showed that living in Punjab or Balochistan province, belonging to lowest wealth quintile, lack of maternal education, previous birth interval

Hookworm infection causes anemia, malnutrition, and growth delay, especially in children living in sub-Saharan Africa. The World Health Organization recommends periodic mass drug administration (MDA) of anthelminthics to school-age children (SAC) as a means of reducing morbidity. Recently, questions have been raised about the effectiveness of MDA as a global control strategy for hookworms and other soil-transmitted helminths (STHs). Genomic DNA was extracted from Necator americanus hookworm eggs isolated from SAC enrolled in a cross-sectional study of STH epidemiology and deworming response in Kintampo North Municipality, Ghana. A polymerase chain reaction (PCR) assay was then used to identify single-nucleotide polymorphisms (SNPs) associated with benzimidazole resistance within the N. americanus β-tubulin gene. Both F167Y and F200Y resistance–associated SNPs were detected in hookworm samples from infected study subjects. Furthermore, the ratios of resistant to wild-type SNP at these two loci were increased in posttreatment samples from subjects who were not cured by albendazole, suggesting that deworming drug exposure may enrich resistance-associated mutations. A previously unreported association between F200Y and a third resistance-associated SNP, E198A, was identified by sequencing of F200Y amplicons. These data confirm that markers of benzimidazole resistance are circulating among hookworms in central Ghana, with unknown potential to impact the effectiveness and sustainability of chemotherapeutic approaches to disease transmission and control.

Hookworms are intestinal nematodes that infect up to 740 million people, mostly in tropical and subtropical regions. Adult worms suck blood from damaged vessels in the gut mucosa, digesting hemoglobin using aspartic-, cysteine- and metalloproteases. Targeting aspartic hemoglobinases using drugs or vaccines is therefore a promising approach to ancylostomiasis control. Based on homology to metalloproteases from other hookworm species, we cloned the Ancylostoma ceylanicum metalloprotease 7 cDNA (Ace-mep-7). The corresponding Ace-MEP-7 protein has a predicted molecular mass of 98.8 kDa. The homology to metallopeptidases from other hookworm species and its predicted transmembrane region support the hypothesis that Ace-MEP-7 may be involved in hemoglobin digestion in the hookworm gastrointestinal tract, especially that our analyses show expression of Ace-mep-7 in the adult stage of the parasite. Immunization of Syrian golden hamsters with Ace-mep-7 cDNA resulted in 50% (p < 0.01) intestinal worm burden reduction. Additionally 78% (p < 0.05) egg count reduction in both sexes was observed. These results suggest that immunization with Ace-mep-7 may contribute to reduction in egg count released into the environment during the A. ceylanicum infection.

Highlights • Co-infection of hookworm with P. falciparum modulates blood parasitemia levels. • Cytokine levels were higher in the parasite infected individuals. • Serum eotaxin level correlate negatively with hookworm intensity. • Deworming drug treatment alters cytokine profiles in hookworm infected subjects., Background Necator americanus (hookworm) and Plasmodium falciparum co-infections are common in endemic communities in rural Ghana. Human immune responses to P. falciparum and hookworm are complex, and the dynamics of cytokine levels and effector mediators are poorly understood. This study aimed to determine the effect of hookworm and P. falciparum co-infection on parasite intensities and cytokine profiles in individuals before and after deworming drug treatment. Methods In this cross-sectional study conducted in the Kintampo North Municipality of Ghana blood and stool samples were analyzed from 984 participants (aged 4–88 years). Stool samples were collected at baseline from all participants and examined for the presence of hookworm using the Kato-Katz method. Blood and stool samples were analysed again two weeks after albendazole treatment of hookworm infected individuals. Malaria parasitaemia was estimated by light microscopy and P. falciparum-specific 18S rRNA gene PCR method used for species identification. Serum levels of circulating cytokines interleukins -5, -10 (IL-5, IL-10), tumor necrosis factor [TNF]-α, and eotaxin [CCL11] were determined using ELISA based methods. Results Malaria parasitaemia was significantly reduced in hookworm and P. falciparum co-infected individuals (p = 0.0018) while hookworm intensity was similar between groups. IL-10 level was significantly higher in the co-infected individuals (39.9 ± 12.2 pg/ml) compared to the single infected or the uninfected group (10.7 ± 7.6 mg/ml). IL-5 level was higher in the hookworm only infected individual. TNF-α levels were higher in all infected groups compared to the uninfected controls. CCL11 levels were significantly higher in subjects infected with hookworm only or co-infected with hookworm and P. falciparum. There was a significantly negative correlation (rs = −0.39, p = 0.021) between hookworm eggs per gram of stool and CCL11 levels in the group mono-infected with hookworm which was not affected by treatment. Treatment with albendazole led to a significant reduction of TNF-α (p = 0.041), IL-5 (p = 0.01) and IL-10 (p = 0.001) levels. Conclusion This study shows that in the absence of other helminths, co-infection of hookworm with P. falciparum may modulate blood parasitemia levels and cytokine responses. Data also show that deworming drug treatment alters these cytokine profiles in hookworm infected subjects. Future studies to elucidate the potential mechanisms underlying these observations should include an assessment of parasite specific cellular responses.

Mass drug administration (MDA) targeting school-age children is recommended by the World Health Organization for the global control of soil-transmitted helminth (STH) infections. Although considered safe and cost-effective to deliver, benzimidazole anthelminthics are variably effective against the three most common STHs, and widespread use has raised concern about the potential for emerging resistance. To identify factors mediating response to albendazole, we conducted a cross-sectional study of hookworm infection in the Kintampo North Municipality of Ghana in 2011. Among 140 school-age children residing in five contiguous communities, the hookworm prevalence was 59% (82/140). The overall cure rate following administration of single-dose albendazole (400 mg) was 35% (27/76), with a community-wide fecal egg reduction rate (ERR) of 61% (95% confidence interval: 51.8-71.1). Significant disparities were observed in albendazole effectiveness by community, with a cure rate as low as 0% (N = 24) in Jato Akuraa and ERRs ranging from 53% to 95% across the five study sites. Individual host factors associated with response to deworming treatment included time since last meal, pretreatment blood hemoglobin level, and mid-upper arm circumference. These data demonstrate significant community-level variation in the effectiveness of albendazole, even among populations living in close proximity. Identification of host factors that influence response to albendazole, most notably the timing of drug administration and nutritional factors, creates an opportunity to enhance the effectiveness of deworming through targeted interventions. These findings also demonstrate the importance of measuring anthelminthic response as part of the monitoring and evaluation of community-based deworming programs.

Nematodes are unable to synthesize fatty acids de novo and must acquire them from the environment or host. It is hypothesized that two unique classes of fatty acid and retinol binding proteins that nematodes produce (fatty acid and retinol binding (FAR) and nematode polyprotein antigen/allergen (NPA)) are used to meet this need. A partial cDNA has been cloned corresponding to four subunits of a putative Ancylostoma ceylanicum NPA (AceNPA). The translated amino acid sequence of AceNPA shares sequence identity with similar proteins from Dictyocaulus viviparus, Ascaris suum, and Ostertagia ostertagi. Immunoblot experiments using a polyclonal anti-AceNPA IgG revealed proteins corresponding to the expected sizes of single, as well as two or three un-cleaved NPA subunits in adult excretory/secretory proteins and soluble adult worm extracts. Immunohistochemistry experiments localize AceNPA to the cuticle, pseudocoelomic space and testes suggesting a role in hookworm biology that is distinct from what has previously been defined for other hookworm lipid binding proteins. A single recombinant subunit of AceNPA (rAceNPAb) demonstrated binding in vitro to fluorescent fatty acids DAUDA, cis-parinaric acid, as well as retinol, at equilibrium dissociation constants in the low micromolar range. Further, in vitro data reveal that rAceNPAb binds fatty acids with chain lengths of C12-C22, with the greatest affinities for arachidonic, linoleic (C18), and eicosapentaenoic (C20) acids.

We examined faecal egg count reduction tests (FECRTs) conducted with hookworm-infected humans in Ghana in 2007 (study 1) and 2010 (study 2) in order to explore aspects of the test analysis. Some subjects showed increased FEC following drug treatment. This occurred mostly in

A panel of 80 compounds was screened for anthelmintic activity against a laboratory strain of Ancylostoma ceylanicum and field isolates of hookworm obtained from school children in the Kintampo North District of the Brong Ahafo Region of Ghana. Although the laboratory strain of A. ceylanicum was more susceptible to the compounds tested than the field isolates of hookworm, a twofold increase in compound concentration resulted in comparable egg hatch percent inhibition for select compounds. These data provide evidence that the efficacy of anthelmintic compounds may be species-dependent and that field and laboratory strains of hookworm differ in their sensitivities to the anthelmintics tested. These data also suggest that both compound concentration and hookworm species must be considered when screening to identify novel anthelmintic compounds.

Hookworms are bloodfeeding intestinal nematodes that are a major cause of anemia in resource-limited countries. Despite repeated exposure beginning in early childhood, humans retain lifelong susceptibility to infection without evidence of sterilizing immunity. In contrast, experimental infection of laboratory animals is typically characterized by varying degrees of resistance following primary infection, although the mechanisms underlying this phenomenon remain unknown. In this study, hamsters subjected to a single drug-terminated infection with 100 third stage hookworm larvae were confirmed to be resistant to pathological effects following a subsequent challenge. In a second experiment, hamsters infected twice-weekly with 10 third stage larvae (low inoculum) exhibited clinical and parasitological evidence of continued susceptibility, while those given 100 L3 (high inoculum) developed apparent resistance within 3 days following the initial exposure. The kinetics of parasite-specific IgA, IgM, and IgG antibody production varied by group, which suggests that the humoral immune response to hookworm infection is stimulated by the nature (frequency and intensity) of larval exposure. These results suggest that intermittent low-inoculum larval exposure, which is characterized by prolonged susceptibility to infection, may serve as a more representative model of human hookworm disease for studies of pathogenesis, as well as drug and vaccine development.

Citizenship education is of central importance in curriculum and schooling, as evidenced by the proliferation of research and writing in the area over the last 20 years. Building on existing citizenship literature, this paper discusses one aspect of a larger project exploring the ways in which citizenship is discursively produced in officially mandated school curriculum and the ways in which students themselves understand and take up narratives of ‘good’ citizenship in light of their diverse experiences and social locations. Using an image-based approach to research, students visually represented and then discussed with researchers their perceptions of good citizenship. What became apparent through the analysis of images and focus group transcripts was the ease with which students, regardless of their social locations, reproduced commonsense narratives of ‘good’ citizenship, including socially sanctioned concern for the environment, a sense of nationalism and national pride, respect for relationships and ...

Summary The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new pharmacophores. Hookworms are blood-feeding, intestinal nematode parasites that infect up to 600 million people worldwide. Vaccination with recombinant Ancylostoma ceylanicum macrophage migration inhibitory factor (rAceMIF) provided partial protection from disease, thus establishing a "proof-of-concept" for targeting AceMIF to prevent or treat infection. A high-throughput screen (HTS) against rAceMIF identified six AceMIF-specific inhibitors. A nonsteroidal anti-inflammatory drug (NSAID), sodium meclofenamate, could be tested in an animal model to assess the therapeutic efficacy in treating hookworm disease. Furosemide, an FDA-approved diuretic, exhibited submicromolar inhibition of rAceMIF tautomerase activity. Structure-activity relationships of a pharmacophore based on furosemide included one analog that binds similarly to the active site, yet does not inhibit the Na-K-Cl symporter (NKCC1) responsible for diuretic activity.

Hookworms are bloodsucking nematodes that afflict up to 740 million persons in tropical and subtropical regions, with Asia and sub-Saharan Africa exhibiting particularly high infection rates. Prevalence, intensity, and pathology often vary considerably at both the regional and local level, and may be influenced by coinfection with other parasitic infections such as malaria. Immunoepidemiological studies suggest that hookworms manipulate the host immune response and may provide some protection from allergy and asthma. There has been substantial progress in elucidating the molecular pathogenesis of hookworm disease, with anticoagulants, protease inhibitors, digestive proteases, and novel excretory/secretory proteins being of particular interest. Mass chemotherapy remains a mainstay of hookworm control strategies, although continued use of drugs may lead to reduced efficacy and treatment failures have been observed. Consequently, a need exists for innovative approaches, such as vaccination; recent studies have identified and/or evaluated candidate vaccine antigens in human and animal models.

Hookworms are human parasites that have devastating effects on global health, particularly in underdeveloped countries. Ancylostoma ceylanicum infects humans and animals, making it a useful model organism to study disease pathogenesis. A. ceylanicum excretory–secretory protein 2 (AceES-2), a highly immunoreactive molecule secreted by adult worms at the site of intestinal attachment, is partially protective when administered as a mucosal vaccine against hookworm anemia. The crystal structure of AceES-2 determined at 1.75 A resolution shows that it adopts a netrin-like fold similar to that found in tissue inhibitors of matrix metalloproteases (TIMPs) and in complement factors C3 and C5. However, recombinant AceES-2 does not significantly inhibit the 10 most abundant human matrix metalloproteases or complement-mediated cell lysis. The presence of a highly acidic surface on AceES-2 suggests that it may function as a cytokine decoy receptor. Several small nematode proteins that have been annotated as TIMPs or netrin-domain-containing proteins display sequence homology in structurally important regions of AceES-2′s netrin-like fold. Together, our results suggest that AceES-2 defines a novel family of nematode netrin-like proteins, which may function to modulate the host immune response to hookworm and other parasites.

In a three-year study, the authors explore students' understandings and experiences of citizenship at two high school sites in Regina, Saskatchewan. Specifically, the authors consider the possibility that social location mediates the extent to which the official social studies curriculum is able to produce students as 'good' citizens. The analysis of student survey responses and focus group conversations suggests the continuing salience of social class in students' understandings of and relationships to the officially sanctioned discourse of ‘good’ citizenship.

SUMMARY Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation ⁄ processing, and relative reductions in CD4 + T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4 + for up to 9 days following intraperitoneal injection (200 lg) of a murine antimouse CD4 monoclonal IgG (clone GK1AE5). CD4 + T-cell

This article examines the importance of treaty education for students living in a province entirely ceded through treaty. Specifically, we ask and attempt to answer the questions “Why teach treaties?” and “What is the effect of teaching treaties?” We build on research that explores teachers’ use of a treaty resource kit, commissioned by the Office of the Treaty Commissioner in Saskatchewan. Working with six classrooms representing a mix of rural, urban and First Nations settings, the research attempts to make sense of what students understand, know and feel about treaties, about First Nations peoples and about the relationships between First Nations and non–First Nations peoples in Saskatchewan. It is revealing that initially students are unable to make sense of their province through the lens of treaty given the commonsense story of settlement they learn through mandated curricula. We offer a critique of the curricular approach in Saskatchewan which separates social studies, history and native st...

Parasitic organisms have evolved specialized strategies to evade immune defense mechanisms. We describe herein an ortholog of the cytokine, macrophage migration inhibitory factor (MIF), which is produced by the obligate intracellular parasite, Leishmania major. The Leishmania MIF protein, Lm1740MIF, shows significant structural homology with human MIF as revealed by a high-resolution x-ray crystal structure (1.03 Å). Differences between the two proteins in the N-terminal tautomerization site are evident, and we provide evidence for the selective, species-specific inhibition of MIF by small-molecule antagonists that target this site. Lm1740MIF shows significant binding interaction with the MIF receptor, CD74 (Kd = 2.9 × 10−8 M). Like its mammalian counterpart, Lm1740MIF induces ERK1/2 MAP kinase activation in a CD74-dependent manner and inhibits the activation-induced apoptosis of macrophages. The ability of Lm1740MIF to inhibit apoptosis may facilitate the persistence of Leishmania within the macrophage and contribute to its evasion from immune destruction.

Hookworm infection is a major cause of anemia and malnutrition in resource-poor countries. Human and animal studies suggest that infection with these intestinal nematodes is associated with impaired cellular immunity, characterized by reduced lymphocyte proliferation in response to both parasite and heterologous antigens. We report here data from studies aimed at defining mechanisms through which hookworms modulate the host cellular immune response. Splenocytes and mesenteric lymph node (MLN) cells from hamsters infected withAncylostoma ceylanicumshowed minimal proliferation in response to mitogen at days 20 and 30 postinfection (p.i.), with partial recovery noted at day 70 p.i. The proliferative capacity of enriched splenocyte T-cell preparations from infected animals following stimulation with hookworm antigens was partially restored in the presence of antigen-presenting cells from uninfected hamsters. Analysis by fluorescence-activated cell sorting revealed that hookworm infection is associated with reduced percentages of both CD4+and surface immunoglobulin G-positive lymphocytes in the spleen and MLN cells. Splenocytes from infected hamsters also secreted more nitric oxide (NO) in culture than did those from naïve animals. Inhibition of NO secretion was associated with partial restoration of the proliferative capacity of splenocytes from infected animals in response to concanavalin A, suggesting a role for NO in mediating this effect. Together, these data demonstrate that hookworm infection is associated with impaired function of antigen-presenting cells and depletion of important lymphocyte subpopulations and also suggests a role for NO in parasite-induced immunosuppression.

SUMMARY Hookworms are bloodfeeding nematodes that reside in the intestinal mucosa. These parasites secrete proteins that induce robust systemic immune responses in humans and experimental animals. By contrast, mucosal immune responses in and around the site of attachment are not described as well. This paper presents data from studies aimed at examining hookworm-specific mucosal antibody responses in a hamster model of Ancylostoma ceylanicum infection. Intestinal flush prepared from infected hamsters was analysed by ELISA and shown to be enriched in IgA-specific for A. ceylanicum excretory–secretory (ES) products. Evaluation of mucosal IgA responses by immunoblot demonstrated that infected hamsters recognized a broad range of ES proteins. Hamsters repeatedly exposed to drug-terminated infections were shown to have enhanced serum IgG and mucosal IgA responses, as well as a high level of protection from challenge infection. Parasite-specific IgA was also detected in the faeces of hamsters undergoing a primary infection, and increasing faecal IgA responses were coincident with significant reductions in intestinal worm burdens and faecal ES output over time. Together these results suggest that secretory IgA may act in concert with other components of the mucosal and systemic immune response to promote protective immunity against hookworm infection and/or disease.

Hookworms, parasitic nematodes that infect nearly one billion people worldwide, are a major cause of anemia and malnutrition. We hypothesize that hookworms actively manipulate the host immune response through the production of specific molecules designed to facilitate infection by larval stages and adult worm survival within the intestine. A full-length cDNA encoding a secreted orthologue of the human cytokine, Macro-phage Migration Inhibitory Factor (MIF) has been cloned from the hookworm Ancylostoma ceylanicum. Elucidation of the three-dimensional crystal structure of recombinant AceMIF (rAceMIF) revealed an overall structural homology with significant differences in the tautomerase sites of the human and hookworm proteins. The relative bioactivities of human and hookworm MIF proteins were compared using in vitro assays of tautomerase activity, macrophage migration, and binding to MIF receptor CD74. The activity of rAceMIF was not inhibited by the ligand ISO-1, which was previously determined to be an inhibitor of the catalytic site of human MIF. These data define unique immunological, structural, and functional characteristics of AceMIF, thereby establishing the potential for selectively inhibiting the hookworm cytokine as a means of reducing parasite survival and disease pathogenesis.

Lectins comprise a family of related proteins that mediate essential cell functions through binding to carbohydrates. Within this protein family, C-type lectins are defined by the requirement of calcium for optimal biologic activity. Using reverse transcription PCR, a cDNA corresponding to a putative C-type lectin has been amplified from the hookworm parasite Ancylostoma ceylanicum. The 550 nucleotide open reading frame of the Ancylostoma ceylanicum C-type Lectin-1 (AceCTL-1) cDNA corresponds to a 167 amino acid mature protein (18706 Da) preceded by a 17 amino acid secretory signal sequence. The recombinant protein (rAceCTL-1) was expressed in Drosophila S2 cells and purified using a combination of affinity chromatography and reverse phase HPLC. Using in vitro carbohydrate binding studies, it was determined that rAceCTL-1 binds N-acetyl-D-glucosamine, a common component of eukaryotic egg cell membranes. Using a polyclonal IgG raised against the recombinant protein, the native AceCTL-1 was identified in sperm and soluble protein extracts of adult male A. ceylanicum by immunoblot. Probing of adult hookworm sections with the polyclonal IgG demonstrated localization to the testes in males, as well as the spermatheca and developing embryos in females, consistent with its role as a sperm protein. Together, these data strongly suggest that AceCTL-1 is a male gender-specific C-type lectin with a function in hookworm reproductive physiology.

Crystal (Cry) proteins produced by the soil bacterium Bacillus thuringiensis (Bt) are harmless to vertebrates, but they are highly toxic to insects and nematodes. Their value in controlling insects that destroy crops and transmit human diseases is well established. Although it has recently been demonstrated that a few individual Bt Cry proteins, such as Cry5B, are toxic to a wide range of free-living nematodes, the potential activity of purified Cry proteins against parasitic nematodes remains largely unknown. We report here studies aimed at characterizing in vitro and in vivo anthelminthic activities of purified recombinant Cry5B against the hookworm parasite Ancylostoma ceylanicum , a bloodfeeding gastrointestinal nematode for which humans are permissive hosts. By using in vitro larval development assays, Cry5B was found to be highly toxic to early stage hookworm larvae. Exposure of adult A. ceylanicum to Cry5B was also associated with significant toxicity, including a substantial reduction in egg excretion by adult female worms. To demonstrate therapeutic efficacy in vivo , hamsters infected with A. ceylanicum were treated with three daily oral doses of purified Cry5B, the benzimidazole anthelminthic mebendazole, or buffer. Compared with control (buffer-treated) animals, infected hamsters that received Cry5B showed statistically significant improvements in growth and blood hemoglobin levels as well as reduced worm burdens that were comparable to the mebendazole-treated animals. These data demonstrate that Cry5B is highly active in vitro and in vivo against a globally significant nematode parasite and that Cry5B warrants further clinical development for human and veterinary use.

Hookworm infection is associated with growth delay and iron deficiency anemia in developing countries. A series of experiments were designed in order to test the hypothesis that host dietary iron restriction mediates susceptibility to hookworm infection using the hamster model of Ancylostoma ceylanicum . Animals were maintained on diets containing either 10 ppm iron (iron restricted) or 200 ppm iron (standard/high iron), followed by infection with A. ceylanicum third-stage larvae. Infected animals fed the standard diet exhibited statistically significant growth delay and reduced blood hemoglobin levels compared to uninfected controls on day 20 postinfection. In contrast, no statistically significant differences in weight or hemoglobin concentration were observed between infected and uninfected animals fed the iron-restricted diet. Moreover, iron-restricted animals were observed to have reduced intestinal worm burdens on day 10 and day 20 postinfection compared to those of animals maintained on the standard/high-iron diet. In a subsequent study, animals equilibrated on diets containing a range of iron levels (10 ppm, 40 ppm, 100 ppm, or 200 ppm) were infected with A. ceylanicum and followed for evidence of hookworm disease. Infected animals from the intermediate-dietary iron (40- and 100-ppm) groups exhibited greater weight loss and anemia than those in the low (10-ppm)- or high (200-ppm)-iron diet groups. Mortality was also significantly higher in the intermediate-dietary-iron groups. These data suggest that severe dietary iron restriction impairs hookworm development in vivo but that moderate iron restriction enhances host susceptibility to severe disease.

This report describes the detection of hookworm excretory/secretory (ES) antigens in soluble hamster fecal extracts by an enzyme-linked immunosorbent assay (ELISA). A rabbit polyclonal IgG antibody against Ancylostoma ceylanicum ES was used to capture hookworm coproantigens that were then detected using pooled, high-titer, infected hamster serum. The ELISA was capable of detecting ES proteins over a range of 10 ng/mL to 10 mug/mL when the antigens were diluted in buffer or uninfected fecal extract, and ES could be detected in infected hamster feces at dilutions up to 1:256. Examination of the kinetics of coproantigen production demonstrated that detectable amounts of ES were produced as early as four days after A. ceylanicum infection, whereas fecal eggs were not observed until day 17. Moreover, fecal ES levels correlated well with intestinal worm burden and could be detected in wet or dry stool samples stored for 14 days over a temperature range of -80 degrees C to 37 degrees C. The fecal ELISA was then adapted to analyze the excretion of AceES-2, a novel immunogenic ES protein recently cloned from A. ceylanicum cDNA. AceES-2 was found to be excreted in feces with kinetics similar to that of whole ES. Examination of individual hookworm antigens by this method will provide new insights into the molecular host-parasite interaction and may form the basis for future diagnostic methods.