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Evolutionary Biology of Parasitism
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
In another possible form of sympatric speciation, allochronic speciation, sympatric populations of the parasite remain separate by virtue of having different periods of transmission. Strains of Schistosoma mansoni specialized to infect either humans or rats have been found in both Guadeloupe and Oman. In the case of strains adapted to humans, infected snails release cercariae at midday when people are likely to be in the water and in contact with cercariae. Strains adapted to rodents, by contrast, release their cercariae from snails in the evening such they are present when nocturnally active rodents are in the water. However, the strains involved have by no means proceeded to reproductive isolation and the barriers to gene flow are likely not absolute: some cercariae shed at midday may persist until the evening hours and infect rodents, or vice versa. Some of the Haemoproteus lineages recovered from blackcaps may also circulate in birds at different times of the year and thus exemplify allochronic speciation.
The Blue Nile Health Project — Objectives, Methods, and Budget
Published in Max J. Miller, E. J. Love, Parasitic Diseases: Treatment and Control, 2020
Sudan’s economy has, for many years, depended largely on irrigation in the agricultural sector, but past growth in production was achieved more through expansion of the scheme than by any increase in yield per hectare. This was particularly relevant in the Gezira/Managil scheme where little modernization or improvement was undertaken. Inadequate canal maintenance with silting, excessive weed growth, and inappropriate water management resulted in insufficient water. Associated with, and aggravating these problems, were malaria, diarrheal diseases, and an increasingly high prevalence of Schistosoma mansoni with severe morbidity in an area in which the infection was initially of no public health importance.
Macrophages and Their Potential Role in Hyperreactive Airways Disease
Published in Devendra K. Agrawal, Robert G. Townley, Inflammatory Cells and Mediators in Bronchial Asthma, 2020
The concept that macrophages might have some active role in allergic forms of asthma arose from the initial observation by Capron and co-workers5 that macrophages possess IgE receptors. These investigators incubated parasitic antigen (Schistosoma mansoni larvae) with sera from rats immune to S. mansoni. Subsequently, they added these larvae to peritoneal macrophages from normal rats and found that these cells both adhered to and became cytotoxic for the schistosomules. Subsequent experiments revealed that serum immune complexes composed of specific antischistosomule IgE and parasite antigen induced these effects.6 They also made another important observation — namely, that the activation of rat macrophage antischistosomule cytotoxicity occurred through the interaction of IgE immune complexes with an IgE receptor on the macrophages.6,7
Prognostic and survival impact of BCL9 and RPS6KB1 copy number variation detected from circulating free DNA in hepatocellular carcinoma
Published in Expert Review of Molecular Diagnostics, 2023
Samar Samir Youssef, Rady Eid El-Araby, Eman Abd El-Razek Abbas, Mohamed Hassany, Tamer Elbaz
Similarly, the current study was able to detect gain in the CN of the RPS6KB1 gene in 24% of the studied HCV-related HCC patients from cfDNA. This result agrees with Shibata T et al. [11], who documented the gain in CN of RPS6KB1gene as one of the recurrently amplified genes in HCC and also to Katoh Et al. [14]. Similar to BCL9, gain in CN of RPS6KB1 significantly correlated with higher BMI in our study. Additionally, this study recorded a higher risk of HCC development in patients with RPS6KB1 gain or a combined gain of RPS6KB1 with BCL9 and evidence of previous Schistosomiasis. A recent Egyptian observational paper focused on the role of Schistosoma mansoni in hepato-carcinogenesis. Previous Schistosoma mansoni infection was associated with HCC (OR 1.59) and significantly affected the overall survival [29].
DC-SIGN mediated internalisation of glycosylated extracellular vesicles from Schistosoma mansoni increases activation of monocyte-derived dendritic cells
Published in Journal of Extracellular Vesicles, 2020
Marije E. Kuipers, Esther N.M. Nolte-‘t Hoen, Alwin J. van der Ham, Arifa Ozir-Fazalalikhan, D. Linh Nguyen, Clarize M. de Korne, Roman I. Koning, John J. Tomes, Karl F. Hoffmann, Hermelijn H. Smits, Cornelis H. Hokke
Schistosoma mansoni is one of the major helminth parasites of humans with over 200 million people infected [1,2]. In the initial phase of infection, schistosome larvae (cercariae) penetrate the skin of the host and transform into schistosomula. These schistosomula larvae will migrate to the circulatory system, develop into adult worms that mate and lay eggs [3]. S. mansoni can live up to 10 years in its host because it has developed successful mechanisms to evade immune responses. To establish this immune evasion, the parasite releases excretory/secretory (E/S) products that act on the host immune system [4]. Among these E/S products are extracellular vesicles (EVs) and evidence is accumulating that parasite-derived EVs contribute to parasite-host interaction [5].The molecular composition of EVs from S. mansoni larvae and adult worms life stages has been partially characterized [6–8], but the interaction of their EVs with host cells remains unexplored.
Supplementation with micronutrients and schistosomiasis: systematic review and meta-analysis
Published in Pathogens and Global Health, 2019
María Morales-Suarez-Varela, Isabel Peraita-Costa, Agustin Llopis-Morales, Agustin Llopis-Gonzalez
As explained, the previous statistical analysis takes into account the infestation with Schistosoma spp. The population may be infested with Schistosoma mansoni, Schistosoma haematobium or both. In this second statistical analysis, the hypothesis is raised whether multimicronutrient supplementation has more effect in the population infected with Schistosoma mansoni alone or in the infestation only with Schistosoma haematobium or if there is no difference between them. Two subgroup analysis were carried out; in one of them the relationship between multimicronutrient supplementation and infestation only with Schistosoma mansoni was studied, and in the other, the relationship between multimicronutrient supplementation and infestation only with Schistosoma haematobium was studied (Figure 5).