| 1. |
- Farouk, Salah E., et al.
(författare)
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Different antibody and cytokine-mediated responses to Plasmodium falciparum parasite in two sympatric ethnic tribes living in Mali
- 2005
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Ingår i: Microbes and infection. - : Elsevier SAS. - 1286-4579 .- 1769-714X. ; 7:1, s. 110-117
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Tidskriftsartikel (refereegranskat)abstract
- The Fulani are known to be less susceptible to Plasmodium falciparum malaria infections and to have lower parasitaemia despite living under similar malaria transmission intensity compared with other ethnic tribes. The aim of the present study was to examine whether the Fulani were more polarised towards Th2 as reflected by higher numbers of malaria-specific IL-4- and IL-10-producing cells and lower numbers of IFN-γ- and IL-12-producing cells as compared to their neighbour ethnic tribe, the Dogon of Mali. Total IgE and both anti-malaria IgE and IgG antibodies were measured by ELISA and the numbers of IL-4-, IFN-γ-, IL-10- and IL-12-producing cells were enumerated using enzyme-linked ImmunoSpot assay (ELISPOT). Numbers of parasite clones were detected by polymerase chain reaction (PCR). The study was performed outside the transmission period and all individuals included were asymptomatic. The results revealed that the Fulani were less parasitised, had fewer circulating parasite clones in their blood, had significantly higher anti-malaria IgG and IgE antibodies and higher proportions of malaria-specific IL-4- and IFN-γ-producing cells compared to the Dogon. The higher antigen-specific production of IL-4 among the Fulani was statistically significant both before and after adjustment for level of spontaneous cytokine production, while greater IFN-γ production only attained statistical significance after adjustment for spontaneous levels. Taken together, the association of higher anti-malarial IgE and IgG antibodies and increased numbers of specific IL-4- and IFN-γ-producing cells compared to the ethnic sympatric tribe, the Dogon, may assist in explaining the lower susceptibility to malaria observed in the Fulani.
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| 2. |
- Ryu, Tsuguru, et al.
(författare)
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HIGH-CONTRAST IMAGING OF INTERMEDIATE-MASS GIANTS WITH LONG-TERM RADIAL VELOCITY TRENDS
- 2016
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 825:2
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Tidskriftsartikel (refereegranskat)abstract
- A radial velocity (RV) survey for intermediate-mass giants has been in operation for over a decade at Okayama Astrophysical Observatory (OAO). The OAO survey has revealed that some giants show long-term linear RV accelerations (RV trends), indicating the presence of outer companions. Direct-imaging observations can help clarify what objects generate these RV trends. We present the results of high-contrast imaging observations of six intermediate-mass giants with long-term RV trends using the Subaru Telescope and HiCIAO camera. We detected co-moving companions to gamma Hya B (0.61(-0.14)(+0.12)M(circle dot)), HD 5608 B (0.10 +/- 0.01M(circle dot)), and HD 109272 B (0.28 +/- 0.06M(circle dot)). For the remaining targets (iota Dra, 18 Del, and HD 14067), we exclude companions more massive than 30-60 M-Jup at projected separations of 1 ''-7 ''. We examine whether these directly imaged companions or unidentified long-period companions can account for the RV trends observed around the six giants. We find that the Kozai mechanism can explain the high eccentricity of the inner planets iota Dra b, HD 5608 b, and HD 14067 b.
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| 3. |
- Tangteerawatana, Piyatida, et al.
(författare)
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IL4 gene polymorphism and previous malaria experiences manipulate anti-Plasmodium falciparum antibody isotype profiles in complicated and uncomplicated malaria.
- 2009
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Ingår i: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875 .- 1475-2875. ; 8:1, s. 286-
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: The IL4-590 gene polymorphism has been shown to be associated with elevated levels of anti-Plasmodium falciparum IgG antibodies and parasite intensity in the malaria protected Fulani of West Africa. This study aimed to investigate the possible impact of IL4-590C/T polymorphism on anti-P. falciparum IgG subclasses and IgE antibodies levels and the alteration of malaria severity in complicated and uncomplicated malaria patients with or without previous malaria experiences. METHODS: Anti-P.falciparum IgG subclasses and IgE antibodies in plasma of complicated and uncomplicated malaria patients with or without previous malaria experiences were analysed using ELISA. IL4-590 polymorphisms were genotyped using RFLP-PCR. Statistical analyses of the IgG subclasses and IgE levels were done by Oneway ANOVA. Genotype differences were tested by Chi-squared test. RESULTS: The IL4-590T allele was significantly associated with anti-P. falciparum IgG3 antibody levels in patients with complicated (P=0.031), but not with uncomplicated malaria (P=0.622). Complicated malaria patients with previous malaria experiences carrying IL4-590TT genotype had significantly lower levels of anti-P. falciparum IgG3 (P=0.0156), while uncomplicated malaria patients with previous malaria experiences carrying the same genotype had significantly higher levels (P=0.0206) compared to their IL4-590 counterparts. The different anti-P. falciparum IgG1 and IgG3 levels among IL4-590 genotypes were observed. Complicated malaria patients with previous malaria experiences tended to have lower IgG3 levels in individuals carrying TT when compared to CT genotypes (P=0.075). In contrast, complicated malaria patients without previous malaria experiences carrying CC genotype had significantly higher anti-P. falciparum IgG1 than those carrying either CT or TT genotypes (P=0.004, P=0.002, respectively). CONCLUSIONS: The results suggest that IL4-590C or T alleles participated differently in the regulation of anti-malarial antibody isotype profiles in primary and secondary malaria infection and, therefore, could play an important role in alteration of malaria severity.
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| 4. |
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| 5. |
- Vafa, Manijeh, et al.
(författare)
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Associations between the IL-4 -590 T allele and Plasmodium falciparum infection prevalence in asymptomatic Fulani of Mali
- 2007
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Ingår i: Microbes and infection. - : Elsevier BV. - 1286-4579 .- 1769-714X. ; 9:9, s. 1043-1048
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we compared the genotype and allele frequencies of the IL-10 -1087 A/G and IL-4 -590 C/T single nucleotide polymorphisms in asymptomatic subjects of two sympatric ethnic tribes differing in susceptibility to malaria, the Fulani and the Dogon in Mali. The genotype data was correlated with ethnicity and malariometric indexes. A statistically significant inter-ethnic difference in allele and genotype frequency for both loci was noted (P < 0.0001). Within the Fulani, the prevalence of Plasmodium falciparum infection, as detected by both microscopy and PCR, was associated with the IL-4 -590 T allele (P = 0.005 and P = 0.0005, respectively), whereas, no such associations were seen in the Dogon. Inter-ethnic differences in spleen rates, higher in the Fulani than the Dogon, were seen between T carriers (TT and CT) of both groups (P < 0.0001). Parasite densities and number of concurrent clones did not vary between IL-4 genotypes within any of the studied groups. These results suggest an association between the IL-4 -590 T allele and P. falciparum prevalence within the Fulani but not the Dogon. No associations between IL-10 genotypes and studied malariometric indexes were observed in any of the two communities.
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