The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Charles H King - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH Open Access Modelling control of Schistosoma haematobium infection: predictions of the long-term impact of mass drug administration in Africa
2016Co-Authors: David Gurarie, Nara Yoon, Martial Ndeffo-mbah, David Durham, Anna E. Phillips, Osvaldo H. Aurelio, Josefo Ferro, Alison P. Galvani, Charles H KingAbstract:Background: Effective control of Schistosomiasis remains a challenging problem for endemic areas of the world. Given knowledge of the biology of transmission and past experience with mass drug administration (MDA) programs, it is important to critically evaluate the likelihood that MDA programs will achieve substantial reductions in Schistosoma prevalence. In implementing the World Health Organization Roadmap for Neglected Tropical Diseases it would useful for policymaking to model projections of the status of Schistosoma control in MDA-treated areas in the next 5–10 years. Methods: Calibrated mathematical models were used to project the effects of different frequency and coverage of MDA for Schistosomiasis Haematobia control in present-day endemic communities, taking into account uncertainties of parasite biology and input data. The modeling approach in this analysis was the Stratified Worm Burden model developed in our earlier works, calibrated using data from longitudinal S. haematobium control trials in Kenya. Results: Model-based simulations of MDA control in typical low-risk and higher-risk communities indicated that infection prevalence can be substantially reduced within 10 years only when there is a high degree of community participation (>70 %) with at least annual MDA. Significant risk for re-emergence of infection remains if MDA is suspended
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modelling control of schistosoma haematobium infection predictions of the long term impact of mass drug administration in africa
Parasites & Vectors, 2015Co-Authors: David Gurarie, Charles H King, Nara Yoon, Anna E. Phillips, Osvaldo H. Aurelio, Josefo Ferro, Alison P. Galvani, Martial L Ndeffombah, David P DurhamAbstract:Effective control of Schistosomiasis remains a challenging problem for endemic areas of the world. Given knowledge of the biology of transmission and past experience with mass drug administration (MDA) programs, it is important to critically evaluate the likelihood that MDA programs will achieve substantial reductions in Schistosoma prevalence. In implementing the World Health Organization Roadmap for Neglected Tropical Diseases it would useful for policymaking to model projections of the status of Schistosoma control in MDA-treated areas in the next 5–10 years. Calibrated mathematical models were used to project the effects of different frequency and coverage of MDA for Schistosomiasis Haematobia control in present-day endemic communities, taking into account uncertainties of parasite biology and input data. The modeling approach in this analysis was the Stratified Worm Burden model developed in our earlier works, calibrated using data from longitudinal S. haematobium control trials in Kenya. Model-based simulations of MDA control in typical low-risk and higher-risk communities indicated that infection prevalence can be substantially reduced within 10 years only when there is a high degree of community participation (>70 %) with at least annual MDA. Significant risk for re-emergence of infection remains if MDA is suspended. In a stable (stationary) ecosystem, Schistosoma reproduction and transmission are sufficiently robust that the process of human infection continues, even under pressure from aggressive MDA. MDA alone is unlikely to interrupt transmission, and once mass treatment is suspended, the prevalence of human infection is likely to rebound to pre-control levels over a period of 25–30 years. MDA success in achieving very low levels of infection prevalence is highly dependent on treatment coverage and frequency within the local human population, and requires that both adults and children be included in drug delivery coverage. Ultimately, supplemental snail control and significant improvements in sanitation will be required to achieve full control of Schistosomiasis by elimination of ongoing Schistosoma transmission.
Monica C Botelho - One of the best experts on this subject based on the ideXlab platform.
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halting schistosoma haematobium associated bladder cancer
International Journal of Cancer Management, 2017Co-Authors: Helena Alves, Monica C Botelho, Joachim RichterAbstract:Background At present Schistosomiasis is endemic in 78 countries affecting more than 260 million people. Schistosomiasis Haematobia alone affects more than 112 millions. Material and methods We performed a computerized search of Pubmed database with keywords: bladder cancer cost and Schistosomiasis mass treatment. Results Bladder cancer is an important sequelae of this infection. In low-resource countries, where this disease is endemic, individuals inflicted with bladder cancer have very limited access to treatment and death is most probably certain. Conclusion Mass treatment with praziquantel is an easy, safe and inexpensive treatment that could save the lives of thousands and reduce the morbidity of millions.
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tumour like phenotypes in urothelial cells after exposure to antigens from eggs of schistosoma haematobium an oestrogen dna adducts mediated pathway
International Journal for Parasitology, 2013Co-Authors: Monica C Botelho, Nuno Vale, Paula Gomes, Gabriel Rinaldi, Julio Santos, Maria Joao Gouveia, Lucio Lara Santos, Paul J Brindley, Jose Manuel Correia Da CostaAbstract:Chronic infection with the blood fluke, Schistosoma haematobium, is associated with squamous cell carcinoma of the bladder. Previously, it has been shown that soluble extracts of mixed sex adult S. haematobium worms (SWAP) are tumourigenic, both in vitro and in vivo. In addition, oestrogen-related molecules in SWAP of S. haematobium down-regulate oestrogen receptors (ERs) alpha and beta in oestrogen responsive cells. Moreover, schistosome oestrogens occur in sera of persons with Schistosomiasis Haematobia and repress transcription of ERs in urothelial cells. Given that eggs of S. haematobium are the developmental stage directly responsible for urogenital disease during Schistosomiasis Haematobia, we suspected that soluble antigens from S. haematobium eggs exhibit similar or more potent tumorigenic capacity. Here we investigated the tumorigenic potential of soluble egg antigens (Sh-SEA) of S. haematobium and the endocrine system in favouring parasitism by schistosomes. The findings confirmed that 6.25μg/ml of Sh-SEA was enough to stimulate cell proliferation, reduce apoptosis and increase oxidative stress of Sh-SEA-exposed urothelial cells. In addition, genotoxic effects of Sh-SEA on these cells were determined by using alkaline single-cell gel electrophoresis (Comet). Furthermore, Liquid Chromatography Diode Array Detection Electron Spray Ionisation Mass Spectrometry indicated the presence of catechol-oestrogens in S. haematobium SEA. A prospective oestrogen-DNA adduct mediated pathway in S. haematobium egg induced bladder cancer is also discussed.
Joachim Richter - One of the best experts on this subject based on the ideXlab platform.
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Halting Schistosoma haematobium - Associated Bladder Cancer
'Kowsar Medical Institute', 2017Co-Authors: Botelho, Monica C., Alves Helena, Joachim RichterAbstract:Background: At present Schistosomiasis is endemic in 78 countries, affecting more than 260 million people. Schistosomiasis Haematobia alone affects more than 112 millions. Evidence Acquisition: We performed a computerized search of in PubMed database with keywords: Bladder Cancer Cost and Schistosomiasis Mass Treatment. Results: Bladder cancer is an important sequelae of this infection. In low-resource countries, where this disease is endemic, individuals inflicted with bladder cancer have very limited access to treatment and death is most probably certain. Conclusions: Mass treatment with praziquantel is an easy, safe, and inexpensive treatment that could save the lives of thousands and reduce the morbidity of millions.info:eu-repo/semantics/publishedVersio
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halting schistosoma haematobium associated bladder cancer
International Journal of Cancer Management, 2017Co-Authors: Helena Alves, Monica C Botelho, Joachim RichterAbstract:Background At present Schistosomiasis is endemic in 78 countries affecting more than 260 million people. Schistosomiasis Haematobia alone affects more than 112 millions. Material and methods We performed a computerized search of Pubmed database with keywords: bladder cancer cost and Schistosomiasis mass treatment. Results Bladder cancer is an important sequelae of this infection. In low-resource countries, where this disease is endemic, individuals inflicted with bladder cancer have very limited access to treatment and death is most probably certain. Conclusion Mass treatment with praziquantel is an easy, safe and inexpensive treatment that could save the lives of thousands and reduce the morbidity of millions.
Yoshiki Aoki - One of the best experts on this subject based on the ideXlab platform.
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cercarial density in the river of an endemic area of Schistosomiasis Haematobia in kenya
American Journal of Tropical Medicine and Hygiene, 1997Co-Authors: Ngethe D. Muhoho, Tatsuya Katsumata, Eisaku Kimura, David K Migwi, W R Mutua, F M Kiliku, Shigehisa Habe, Yoshiki AokiAbstract:The cercarial density in natural water and number of infected Bulinus globosus were monitored over a one-year period to identify the transmission foci in an endemic area of Schistosomiasis Haematobia in Kenya. Overall prevalence and intensity of infection of the study community were 59.2% and 10.9 eggs/10 ml of urine. Cercariometry was carried out on 456 occasions at 20 study sites while snail sampling was done on 465 occasions at the same sites over a one-year period. Cercariometry was exclusively done at flowing water habitats. The results showed the focality and seasonality of transmission. Cercariae were detected on 44 occasions at 11 sites. The detections were made on seven occasions at two study sites, six occasions at one site, four occasions at four sites, three occasions at one site, two occasions at two sites, and one occasion at one site. Densities of 1-4 cercariae/100 liters of water were found on 31 occasions. Five to nine cercariae/100 liters of water were found on seven occasions, 10-19 cercariae/100 liters of water were found on two occasions, and high cercarial densities greater than 20 cercariae/100 liters of water were found on four occasions. The highest count was 52 cercariae/100 liters of water. The presence of cercariae in natural water was shown to depend on the water temperature, but the intensity and duration of sunlight did not affect the presence of cercariae in water. The monthly variability of cercarial density was proportional to the number of infected snails. Cercarial density was highest in March and April, in the middle of the rainy season, whereas no cercariae were detected in cool dry season. The snail population peaked late in March, the beginning of the long rainy season, remained high for two months, and decreased rapidly late in May when heavy rain occurred. The overall infection rate of snails was 7.3% and the majority of infected snails were collected from March to May. There was no definite correlation between the presence or absence of cercariae and infected snails. Cercariae were frequently found where infected snails were absent and cercariae were sometimes absent where infected snails were present. Cercariometry and snail sampling remain quite complementary in identifying the transmission foci of Schistosomiasis.
Botelho M.c - One of the best experts on this subject based on the ideXlab platform.
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Could Estradiol be used as a biomarker of infection in Schistosoma haematobium infected patients?
2017Co-Authors: Botelho M.c, Alves H., Cardoso R., Bordalo A., Richter J.Abstract:Urogenital Schistosomiasis is a chronic infection caused by the human blood fluke Schistosoma haematobium. Schistosomiasis Haematobia is a known risk factor for cancer leading to squamous cell carcinoma of the urinary bladder (SCC). This is a neglected tropical disease endemic in many countries of Africa and the Middle East. Schistosome eggs produce catechol-estrogens. These estrogenic molecules are metabolized to active quinones that cause alterations in DNA (leading in other contexts to breast or thyroid cancer). Our group has shown that schistosome egg associated catechol estrogens induce tumor-like phenotypes in urothelial cells, originated from parasite estrogen-host cell chromosomal DNA adducts and mutations. Also we have demonstrated that these molecules are detected as Estradiol in sera of infected patients.N/
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CYP2D6 and IL-6 c-174G variants in Schistosomiasis Haematobia
2016Co-Authors: Cordeiro R., Alves H., Richter J., Bordalo A., Botelho M.cAbstract:AIM: To study the polymorphic variants in CYP2D6 and the C-174G promoter polymorphism of the IL-6 gene on S. haematobium infected patients from an endemic area of Guinea Bissau. BACKGROUND: - Our group has shown that schistosome egg associated catechol estrogens induce tumor-like phenotypes in urothelial cells. These estrogen metabolites might also be the cause of Schistosomiasis associated infertility; - The cytochrome P450 (CYP) genes are oxygenases involved in estrogen biosynthesis and metabolism, generation of DNA damaging procarcinogens, and response to anti-estrogen therapies; - IL6 Interleukin-6 (IL-6) is a pleiotropic cytokine expressed in many tissues. These cytokine is largely expressed in female urogenital tract as well as reproduction organs. Very high or very low levels of IL-6 are associated with estrogen metabolism imbalance.N/
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CYP2D6 and IL-6 C-174G variants in Schistosomiasis Haematobia
2016Co-Authors: Cardoso R., Alves H., Richter J., Bordalo A., Botelho M.cAbstract:Aim: Study polymorphic variants in CYP2D6 and the C-174G promoter polymorphism of the IL-6 gene on S. haematobium infected patients from and endemic area of Guinea Bissau. Background: - Schistosome egg associated catechol estrogens induce tumor-like phenotypes in urothelial cells and might cause Schistosomiasis associated infertility (Botelho et al, Trends in Parasitol, 2015); - The cytochrome P450 (CYP) genes are involved in estrogen biosynthesis and metabolism and generation of DNA damaging procarcinogens (Blackburn et al, Cancer Causes and Control, 2015); - Very high or very low levels of IL-6 are associated with estrogen metabolism imbalance.N/
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The role of estrogens and estrogen receptor signaling pathways in cancer and infertility: the case of schistosomes
'Elsevier BV', 2015Co-Authors: Botelho M.c, Alves H., Barros A.m., Rinaldi G., Brindley P.j., Sousa M.Abstract:Schistosoma haematobium, a parasitic flatworm that infects more than 100 million people, mostly in the developing world, is the causative agent of urogenital Schistosomiasis, and is associated with a high incidence of squamous cell carcinoma (SCC) of the bladder. Schistosomiasis Haematobia also appears to negatively influence fertility, and is particularly associated with female infertility. Given that estrogens and estrogen receptors are key players in human reproduction, we speculate that schistosome estrogen-like molecules may contribute to infertility through hormonal imbalances. Here, we review recent findings on the role of estrogens and estrogen receptors on both carcinogenesis and infertility associated with urogenital Schistosomiasis and discuss the basic hormonal mechanisms that might be common in cancer and infertility
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Bladder cancer and urinary Schistosomiasis in Angola
'ACT Publishing Group', 2015Co-Authors: Botelho M.c, Figueiredo J., Alves H.Abstract:J Nephrol Res. Author manuscript; available in PMC 2015 Jul 9. Disponível em: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4497783/Schistosomiasis Haematobia is among the most prevalent parasitosis in Angola. The pathology is characterized by serious and irreversible lesions in the urogenital tract induced by chronic infection with the parasite that can eventually lead to squamous cell carcinoma of the bladder. Considering the frequency and severe morbidity observed, even in younger ages, the purpose of this study was to assess the prevalence and morbidity of S. haematobium infection in Angola. A baseline survey was conducted between November 2007 and February 2008. A randomly sample of 300 inhabitants aged 15 to 75 years old participated in this study. Prevalence of S. haematobium infection was 71.7 % (215/300). Infection was higher in females (56.3 %) but no significant difference was found in prevalence and intensity between gender and age groups. The predominant selfreported symptoms were dysuria (91.2 %), hypogastralgia (88.7 %) and haematuria (87.1%) and these symptoms were strongly associated with S. haematobium infection (p
