144 research outputs found
Integrated analysis of innate, Th1, Th2, Th17, and regulatory cytokines identifies changes in immune polarisation following treatment of human schistosomiasis.
No full textBACKGROUND: Schistosomiasis elicits cross-regulatory immune responses, but it is unclear how antihelminthic treatment affects this balance. This study integrates data on 13 cytokines elicited by 3 schistosome to examine how praziquantel treatment alters immune polarization and whether post-treatment cytokine profiles influence reinfection status. METHODS: Venous blood from 72 Schistosoma haematobium-exposed participants was cultured with schistosome egg, adult worm, and cercaria antigens pre- and 6 weeks post-praziquantel treatment. Innate inflammatory (tumor necrosis factor α [TNF-α], interleukin(IL-)-6, IL-8), Th1 (interferon γ [IFN-γ], IL-2, IL-12p70), Th2 (IL-4, IL-5, IL-13), Th17 (IL-17A, IL-21, IL-23p19), and regulatory (IL-10) cytokines were quantified via enzyme-linked immunosorbent assay. Cytokine data was integrated using nonmetric multidimensional scaling and factor analysis. RESULTS: Egg-specific cytokine phenotypes became more proinflammatory post-treatment due to increased TNF-α, IL-6, IL-8, IFN-γ, IL-12p70, and IL-23 levels. Post-treatment cercariae-specific responses were also more proinflammatory reflecting elevated IL-8. In contrast, post-treatment adult worm-specific responses were less inflammatory, reflecting lower post-treatment IL-6. A combination of egg-induced IL-6, IL-12p70, IL-21, and IL-23 and adult worm-induced IL-5 and IL-21 post-treatment was associated with reduced reinfection risk 18 months later. CONCLUSIONS: Praziquantel treatment markedly alters polarization of schistosome-specific cytokine responses, and these changes, particularly in response to egg-stage parasites, may promote resistance to reinfection
Cytokine responses to <it>Schistosoma haematobium </it>in a Zimbabwean population: contrasting profiles for IFN-γ, IL-4, IL-5 and IL-10 with age
No full textAbstract Background The rate of development of parasite-specific immune responses can be studied by following their age profiles in exposed and infected hosts. This study determined the cytokine-age profiles of Zimbabweans resident in a Schistosoma haematobium endemic area and further investigated the relationship between the cytokine responses and infection intensity. Methods Schistosome adult worm antigen-specific IFN-γ, IL-4, IL-5 and IL-10 cytokine responses elicited from whole blood cultures were studied in 190 Zimbabweans exposed to S. haematobium infection (aged 6 to 40 years old). The cytokines were measured using capture ELISAs and the data thus obtained together with S. haematobium egg count data from urine assays were analysed using a combination of parametric and nonparametric statistical approaches. Results Age profiles of schistosome infection in the study population showed that infection rose to peak in childhood (11–12 years) followed by a sharp decline in infection intensity while prevalence fell more gradually. Mean infection intensity was 37 eggs/10 ml urine (SE 6.19 eggs/10 ml urine) while infection prevalence was 54.7%. Measurements of parasite-specific cytokine responses showed that IL-4, IL-5 and IL-10 but not IFN-γ followed distinct age-profiles. Parasite-specific IL-10 production developed early, peaking in the youngest age group and declining thereafter; while IL-4 and IL-5 responses were slower to develop with a later peak. High IL-10 producers were likely to be egg positive with IL-10 production increasing with increasing infection intensity. Furthermore people producing high levels of IL-10 produced little or no IL-5, suggesting that IL-10 may be involved in the regulation of IL-5 levels. IL-4 and IFN-γ did not show a significant relationship with infection status or intensity and were positively associated with each other. Conclusion Taken together, these results show that the IL-10 responses develop early compared to the IL-5 response and may be down-modulating immunopathological responses that occur during the early phase of infection. The results further support current suggestions that the Th1/Th2 dichotomy does not sufficiently explain susceptibility or resistance to schistosome infection.</p
Differential recognition patterns of Schistosoma haematobium adult worm antigens by the human antibodies IgA, IgE, IgG1 and IgG4
No full textAbstract Schistosoma haematobium antigen recognition profiles of the human isotypes IgA, IgE, IgG1 and IgG4 were compared by image analysis of western blots. Adult worm antigens separated by 2-dimensional gel electrophoresis were probed with pooled sera from Zimbabweans resident in a S. haematobium endemic area, followed by identification of individual antigenic parasite proteins using mass spectrometry. Overall, IgG1 reacted with the largest number of antigens, followed by IgE and IgA which detected the same number, while IgG4 detected the fewest antigens. IgE recognised all the antigens reactive with IgG4 as well as an additional four antigens; an isoform of 28kDaGST, phosphoglycerate kinase, actin 1 and calreticulin. IgG1 additionally recognised fatty acid binding protein, triose-phosphate isomerase, and heat shock protein 70, which were not recognised by IgA. Recognition patterns varied between some isoforms e.g. the 2 fructose 1-6-bis-phosphate aldolase isoforms differentially recognised by IgA and IgG1. Although the majority of S. haematobium adult worm antigens are recognised by all the four isotypes there are clear restrictions in antibody recognition for some antigens. This may partly explain differences observed in isotype dynamics at a population level. Differential recognition patterns for some isoforms indicated in the study have potential importance for vaccine developmen
Association between Micronutrients (Vitamin A, D, Iron) and Schistosome-Specific Cytokine Responses in Zimbabweans Exposed to Schistosoma haematobium
No full textMicronutrients play an important role in the development of effective immune responses. This study characterised a populations exposed to schistosome infections in terms of the relationship between micronutrients and immune responses. Levels of retinol binding protein (RBP; vitamin A marker), vitamin D, ferritin and soluble transferrin receptor (sTfR), and C reactive protein (CRP) were related to levels of schistosome specific cytokines (IFN-γ, IL-4/5/10) in 40 Zimbabweans (7–54 years) exposed to Schistosoma haematobium infection. 67.2% of the participants were deficient in vitamin D. RBP levels were within normal ranges but declined with age. The two indicators of iron levels suggested that although levels of stored iron were within normal levels (normal ferritin levels), levels of functional iron (sTfR levels) were reduced in 28.6% of the population. Schistosome infection alone was not associated with levels of any of the micronutrients, but altered the relationship between parasite-specific IL-4 and IL-5 and levels of ferritin and sTfR
Theology, innovation and Society: Towards developing Dialogical Theology for African society
No full textTheology and society are inseparable due to the fact that they are both composed of that
which makes for both human and universal well-being. Indeed the two have through the ages
inspired each other in the pursuit of a better world. This paper aims to explore three
religions; African Indigenous Religion (AIR) Islam and Christianity as practised in
developing countries such as Kenya, with the intention of deducing whether or not believers
of these religions (can engage) engage in dialogue with each other for the purpose of
providing sustainable solutions for community well-being and wholeness. Theology of
dialogue is a methodology used by the author, as a means for innovation; towards creating
harmony and equilibrium in a plural and multi-religious Kenyan society and Africa in
general. Of significance for this timely theological concept in Africa are the dreams that need
achievement; the Millennium Development Goals and state visions such as the Kenya 2030
vision. In approaching the subject, the author shall endeavor to outline pre-colonial, colonial
and post-colonial religious histories in Africa. The author shall use the Midzi-Chenda
(written Mijiknda) community of Coastal Kenya as a case study population. This choice is
due to their diverse and long-lived inter-cultural and inter-religious experiences, particularly
with the Arab, Portuguese and British conquests along the East Coast of Africa. The triple
conquest experiences influenced the Midzi-Chenda community negatively and positively in all
spheres of their life-system; economic, political and religious, compelling them to embrace
foreign culture, religion and politics, all of which gradually shaped their theological
parameters. This latter experience and the contemporary post-colonial religious wave
significantly situate the theology of dialogue as a benchmark for innovation in African
society
Seismic hazard assessment in Eastern and Southern Africa.
No full textSeismic hazard assessment for the Eastern and Southern Africa region was done using the probabilistic approach.
Seismic hazard maps for 10% exceedance in 50 years, 10% exceedance in 100 years, as well as for 50 and 100
years return periods were prepared using the FRISK88M software. The area involved covers a wide region bounded
by latitudes 400 S-25?N and longitudes 100E and 55?E. Input parameters for the computations were obtained using
the recent earthquake catalogue compiled by Turyomurugyendo. The catalogue which covers the time period
627-1994, contains earthquakes within the area bounded by 400 S-25?N and 100 E-55?E, with homogeneous
magnitudes (M). Since a Poisson model of earthquake occurrence is assumed, dependent events were cleaned
from the catalogue. Attenuation relations for the Eastern and Southern Africa region based on the strong motion
data are virtually non-existent. However, attempts have been made recently by Jonathan 'and Twesigomwe to
establish an average attenuation relation for the region. These relations were used in the computations. Possible
uncertainties in the attenuation relations were accounted for using the logic-tree formalism. The results are presented
in seismic hazard maps in terms of Peak Ground Acceleration (PGA) for the mean and the 85th percentile. The
distribution ofPGA values indicate relatively high hazard along the EastAfrican rift system. In the northern segments
of the rift system, they exceed 250 gals for 10% probability of exceedence in 50 years.,International Lithosphere Program (ILP) through the Global Seismic Hazard Assessment Program (GSHAP).
UNESCO and lASPE for contributing some funding at various workshops related to the preliminary work on seismic hazard
An intensity database for earthquakes in South Africa from 1912 to 2011
No full textA database of intensity observations from instrumentally-recorded earthquakes in South Africa has been compiled as a contribution to the characterisation of seismic hazard. The database contains about 1,000 intensity data points (IDPs) that have been assigned from macroseismic observations retrieved from newspaper reports and questionnaires, and also digitised from previously published isoseismal maps. The database includes IDPs from 57 earthquakes with magnitudes in the range of Mw 2.2 to 6.4, for epicentral distances up to 1,000 km. Sixteen events have 20 or more IDPs, with half of these events having more than 80 IDPs. The database is dominated by relatively low intensity values, mostly determined from human perception of shaking rather than structural damage. However, 19 IDPs correspond to intensity values greater than VI MMI-56. Using geological maps of South Africa, the sites of 60% the IDPs were geologically classified as either ‘rock’ or ‘soil’, the uncertainty in locations precluding such a classification for the remaining data points. A few of the IDPs identified as being from soil sites appear to be strongly influenced by site effects and these were removed from the trimmed database created for exploring ground-motion levels. The trimmed database included 15 earthquakes which have a minimum of five useful IDPs, excluding those with intensity MMI=I and those based on a single observation. After removing such points, and those identified as clear ‘outliers’, a total of 436 useful IDPs were selected.Published1183-12053T. Pericolosità sismica e contributo alla definizione del rischioJCR Journalreserve
Elimination of STH morbidity in Zimbabwe : Results of 6 years of deworming intervention for school-age children
No full textThis paper reports the prevalence and intensity of soil-transmitted helminth (STH) infections measured in Zimbabwe before and after a control intervention based on annual deworming of school-age children (SAC) conducted from 2012 to 2018. In 2010, epidemiological data were collected from 13 195 SAC in 255 randomly selected schools in all districts nationwide using, as diagnostic methods, the Kato–Katz and the formal ether stool concentration technique. At follow up, conducted in 2017, only Kato–Katz was performed; specimens were collected from 13 352 children in 336 schools. The data were evaluated using a geospatial approach. The national prevalence of STH infection in SAC was estimated at 5.8% at baseline, with 0.8% of infections of moderate and heavy intensity. Preventive chemotherapy (PC) targeted all 2.5 million children of school age enrolled in Zimbabwe, with coverage ranging from 49% to 85%. At follow up, national prevalence of STH in SAC was estimated at 0.8%; infections of moderate and heavy intensity almost disappeared (0.1% prevalence). As a result, Zimbabwe can suspend deworming activities in 54 districts and reduce the frequency of PC in the remaining six districts. The total amount of albendazole tablets needed will be approximately 100 000 a year. © 2020 Midzi et al
Knowledge attitudes and practices of grade three primary school children in relation to schistosomiasis, soil transmitted helminthiasis and malaria in Zimbabwe
No full textHelminth infection rates in grade three children are used as proxy indicators of community infection status and to guide treatment strategies in endemic areas. However knowledge, attitudes and practices (KAP) of this target age group (8-10 years) in relation to schistosomiasis, soil transmitted helminthiasis (STHs) and malaria is not known at a time when integrated plasmodium - helminth control strategies are being advocated. This study sought to assess KAP of grade 3 children in relation to schistosomiasis, STHs and malaria in order to establish an effective school based health education for disease transmission control. Grade 3 children (n = 172) attending four randomly selected primary schools (one in rural and 3 in the commercial farming areas) in Zimbabwe were interviewed using a pre-tested interviewer administered questionnaire. The urine filtration technique was used to determine S. haematobium infection status. Infection with S. mansoni and STHs was determined using a combination of results from the Kato Katz and formol ether concentration techniques. P. falciparum was diagnosed by examination of Giemsa stained thick blood smears. It was observed that 32.0%, 19.2% and 4.1% of the respondents had correct knowledge about the causes of schistosomiasis, malaria and STHs, respectively, whilst 22.1%, 19.2% and 5.8% knew correct measures to control schistosomiasis, malaria and STHs. Sixty-two percent and 44.8% did not use soap to wash hands after toilet and before eating food respectively, whilst 33.1% never wore shoes. There were no functional water points and soap for hand washing after toilet at all schools. There was a high prevalence distribution of all parasites investigated in this study at Msapa primary school - S. haematobium (77.8%), S. mansoni (33.3%) hookworms (29.6%) and P.falciparum (48.1%). Reports that participant had suffered from schistosomiasis and malaria before were significantpredictors of these diseases (p = 0.001 and p = 0.042, respectively). Report that participant had blood in urine on the day of examination was a significant predictor of schistosomiasis (p = 0.045). There is a critical need for targeting health messages through schools in order to reach the most susceptible schoolchildren. This will empower the schoolchildren with the basic knowledge and skills ultimatel
The feminisation of poverty and victimhood in Dangarembga's print oeuvre: Cyclical evocations of nervous conditions, survival, and agency
No full textA dissertation submitted in partial fulfilment of the requirements for the degree of
Doctor of Philosophy (Education)Feminisation of poverty is a term that was coined by Diana Pearce in 1976 after observing an increased concentration of income poverty among women in America (Peterson, 1987). This term was applied in the analysis of Tsitsi Dangarembga’s oeuvre, mainly focusing on the victimhood, cyclical evocations of nervous conditions, survival strategies and agency that Zimbabwean women experienced and are still experiencing. This dissertation employed a qualitative desktop literary in the examination of four novels, Nervous Conditions (1988), The Book of Not (2006), This Mournable Body (2018) – which make up a trilogy spanning up to 30 years; and She No Longer Weeps (1987). The researcher employed Africana Womanism, STIWANISM, and Nego-feminism literary theories to underpin this study, from examining the complex position that African women face in the light of detrimental effects of colonisation and its impact and legacy as it integrates with traditional patriarchal structures as articulated in Dangarembga’s novels. Africana Womanism as a concept was used so as to accommodate the characteristics of the African society which are unique and different because of its cultural, political, historical and social backgrounds, as other feminisms are peculiar to their place of origin. STIWANISM understands the female struggle from the perspective of African feminism which is entirely dependent on the commitment from both sexes, and not a woman affair as emphasised by other feminisms. Nego-feminism places both genders side by side as men and women to try and negotiate their places in life and establish a harmonious co- existence, with the negative patriarchal structures melting away. The study analysed how the author used the novels to expose issues related to post- colonial conditions, gender inequalities, cultural limitations, female self- definition and struggle for survival. The study found that the women in the Shona society are presented diversely depending on the socio- cultural background. Dangarembga strategically captured a world before and after independent Zimbabwe (1980s), where her main theme were her two protagonists’ struggles to reshape women’s heterosexuality and femininity in a religiously conservative society adopted in a colonial era. The shared themes of womanhood that are depicted in all the texts are the need for a shift of women from the margins of the society to becoming priorities economically, socially, and culturally. This is the recurring theme whether the setting is in the 1980s or the 2000s, rural or urban; Shona women are still victims of the nervous conditions surrounding them
- …
