The role of estradiol metabolism in urogenital schistosomiasis-induced bladder cancer.

Urogenital schistosomiasis is a neglected tropical disease that can lead to bladder cancer. How urogenital schistosomiasis induces carcinogenesis remains unclear, although there is evidence that the human blood fluke Schistosoma haematobium, the infectious agent of urogenital schistosomiasis, releases estradiol-like metabolites. These kind of compounds have been implicated in other cancers. Aiming for enhanced understanding of the pathogenesis of the urogenital schistosomiasis-induced bladder cancer, here we review, interpret, and discuss findings of estradiol-like metabolites detected in both the parasite and in the human urine during urogenital schistosomiasis. Moreover, we predict pathways and enzymes that are involved in the production of these metabolites emphasizing their potential effects on the dysregulation of the tumor suppressor gene p53 expression during urogenital schistosomiasis. Enhanced understanding of these potential carcinogens may not only shed light on urogenital schistosomiasis-induced neoplasia of the bladder, but would also facilitate development of interventions and biomarkers for this and other infection-associated cancers at large.

Mobile-Based Analysis of Malaria-Infected Thin Blood Smears: Automated Species and Life Cycle Stage Determination.

Microscopy examination has been the pillar of malaria diagnosis, being the recommended procedure when its quality can be maintained. However, the need for trained personnel and adequate equipment limits its availability and accessibility in malaria-endemic areas. Rapid, accurate, accessible diagnostic tools are increasingly required, as malaria control programs extend parasite-based diagnosis and the prevalence decreases. This paper presents an image processing and analysis methodology using supervised classification to assess the presence of malaria parasites and determine the species and life cycle stage in Giemsa-stained thin blood smears. The main differentiation factor is the usage of microscopic images exclusively acquired with low cost and accessible tools such as smartphones, a dataset of 566 images manually annotated by an experienced parasilogist being used. Eight different species-stage combinations were considered in this work, with an automatic detection performance ranging from 73.9% to 96.2% in terms of sensitivity and from 92.6% to 99.3% in terms of specificity. These promising results attest to the potential of using this approach as a valid alternative to conventional microscopy examination, with comparable detection performances and acceptable computational times.

Insight into the molecular basis of Schistosoma haematobium-induced bladder cancer through urine proteomics.

Infection due to Schistosoma haematobium is carcinogenic. However, the cellular and molecular mechanisms underlying urogenital schistosomiasis (UGS)-induced carcinogenesis have not been well defined. Conceptually, early molecular detection of this phenomenon, through non-invasive procedures, seems feasible and is desirable. Previous analysis of urine collected during UGS suggests that estrogen metabolites, including depurinating adducts, may be useful for this purpose. Here, a new direction was pursued: the identification of molecular pathways and potential biomarkers in S. haematobium-induced bladder cancer by analyzing the proteome profiling of urine samples from UGS patients. GeLC-MS/MS followed by protein-protein interaction analysis indicated oxidative stress and immune defense systems responsible for microbicide activity are the most representative clusters in UGS patients. Proteins involved in immunity, negative regulation of endopeptidase activity, and inflammation were more prevalent in UGS patients with bladder cancer, whereas proteins with roles in renal system process, sensory perception, and gas and oxygen transport were more abundant in subjects with urothelial carcinoma not associated with UGS. These findings highlighted a Th2-type immune response induced by S. haematobium, which seems to be further modulated by tumorigenesis, resulting in high-grade bladder cancer characterized by an inflammatory response and complement activation alternative pathway. These findings established a starting point for the development of multimarker strategies for the early detection of UGS-induced bladder cancer.

Differential responses of epithelial cells from urinary and biliary tract to eggs of Schistosoma haematobium and S. mansoni.

Chronic urogenital schistosomiasis can lead to squamous cell carcinoma of the bladder. The International Agency for Research on Cancer classifies the infection with S. haematobium as a group 1 carcinogen, a definitive cause of cancer. By contrast, hepatointestinal schistosomiasis due to the chronic infection with S. mansoni or S. japonicum associated with liver periportal fibrosis, does not apparently lead to malignancy. The effects of culturing human epithelial cells, HCV29, established from normal urothelium, and H69, established from cholangiocytes, in the presence of S. haematobium or S. mansoni eggs were investigated. Cell growth of cells co-cultured with schistosome eggs was monitored in real time, and gene expression analysis of oncogenesis, epithelial to mesenchymal transition and apoptosis pathways was undertaken. Schistosome eggs promoted proliferation of the urothelial cells but inhibited growth of cholangiocytes. In addition, the tumor suppressor P53 pathway was significantly downregulated when exposed to schistosome eggs, and downregulation of estrogen receptor was predicted in urothelial cells exposed only to S. haematobium eggs. Overall, cell proliferative responses were influenced by both the tissue origin of the epithelial cells and the schistosome species.

Latent schistosomiasis in Portuguese soldiers.

Schistosomiasis was diagnosed in two Portuguese soldiers who had been deployed to Portuguese colonies in Africa. The first veteran was diagnosed as having schistosomiasis 34 years after returning from Angola, and the second veteran was found with Schistosoma haematobium infection 40 years after returning from Mozambique. The patient with Schistosoma mansoni had an active infection, because eggs were recovered with living miracidia. The second patient had developed urothelial cancer, but eggs recovered were calcified.

Why does infection with some helminths cause cancer?

Infections with Opisthorchis viverrini, Clonorchis sinensis and Schistosoma haematobium are classified as Group 1 biological carcinogens: definitive causes of cancer. These worms are metazoan eukaryotes, unlike the other Group 1 carcinogens including human papilloma virus, hepatitis C virus, and Helicobacter pylori. By contrast, infections with phylogenetic relatives of these helminths, also trematodes of the phylum Platyhelminthes and major human pathogens, are not carcinogenic. These inconsistencies prompt several questions, including how might these infections cause cancer? And why is infection with only a few helminth species carcinogenic? Here we present an interpretation of mechanisms contributing to the carcinogenicity of these helminth infections, including roles for catechol estrogen- and oxysterol-metabolites of parasite origin as initiators of carcinogenesis.

Evaluation of a simple sedimentation method (modified McMaster) for diagnosis of bovine fascioliosis.

A coprological sedimentation method is evaluated for quantification of egg shedding in bovine faeces. Through the inclusion of different number of Fasciola hepatica eggs in negative faeces, egg recovery rate and the sensitivity of the method were determined. The mean egg recovery rate of the technique was 76.72+/-15.42%. The sensitivity of the method was 33.3% whenever eggs/g of faeces (EPG) are less than 1.5 and 100% for higher values. To improve the diagnostic accuracy with this technique, it is advisable to increase the sample from 10 to 30g of faeces when manipulating low egg shedding, which allowed for a sensitivity of 83.3%. Regression equations were calculated to quantify the relationship between the number of recovered and incorporated eggs.

Urinary estrogen metabolites and self-reported infertility in women infected with Schistosoma haematobium.

BACKGROUND: Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional study was undertaken of female residents of a region in Bengo province, Angola, endemic for schistosomiasis haematobia. Ninety-three women and girls, aged from two (parents interviewed) to 94 years were interviewed on present and previous urinary, urogenital and gynecological symptoms and complaints. Urine was collected from the participants for egg-based parasitological assessment of schistosome infection, and for liquid chromatography diode array detection electron spray ionization mass spectrometry (LC/UV-DAD/ESI-MSn) to investigate estrogen metabolites in the urine. Novel estrogen-like metabolites, potentially of schistosome origin, were detected in the urine of participants who were positive for eggs of S. haematobium, but not detected in urines negative for S. haematobium eggs. The catechol-estrogens/ DNA adducts were significantly associated with schistosomiasis (OR 3.35; 95% CI 2.32-4.84; P≤0.001). In addition, presence of these metabolites was positively associated with infertility (OR 4.33; 95% CI 1.13-16.70; P≤0.05). CONCLUSIONS/SIGNIFICANCE: Estrogen metabolites occur widely in diverse metabolic pathways. In view of the statistically significant association between catechol-estrogens/ DNA adducts and self-reported infertility, we propose that an estrogen-DNA adduct mediated pathway in S. haematobium-induced ovarian hormonal deregulation could be involved. In addition, the catechol-estrogens/ DNA adducts described here represent potential biomarkers for schistosomiasis haematobia.

Carcinogenic ability of Schistosoma haematobium possibly through oncogenic mutation of KRAS gene.

Schistosoma haematobium is a parasitic flatworm that infects millions of people, mostly in the developing world, and is associated with high incidence of bladder cancer, although why is not clear. Previously, we have used CD-1 mice to show that Schistosoma haematobium total antigen (Sh) has a carcinogenic ability. Sh intravesically instillation induced the development of several urothelial lesions, namely nodular hyperplasia and dysplasia (LGIUN-Low Grade Intra-Urothelial Neoplasia) after 40 weeks of treatment. These results suggested that Sh induce urothelium malignization. Bladder carcinoma frequently harbours gene mutations that constitutively activate the receptor tyrosine kinase-Ras pathway for this reason we studied activating mutations in KRAS gene. Twenty percent of the bladders with dysplasia presented a KRAS mutation in codon 12 of exon 2. We concluded from these results that the parasite extract of S. haematobium has carcinogenic ability possibly through oncogenic mutation of KRAS gene.

Granulomatous-like immune reaction and hepatic fibrosis induced by Schistosoma haematobium immature worms.

Golden hamsters were inoculated with Schistosoma haematobium cercariae to examine histological lesions at different time points over an 18 month period of infection. Hamsters were sacrificed 26 weeks and 82 weeks after inoculation. The parasite was found in the blood and in the liver of infected animals as was expected, but we found exclusively male worms, no female worms nor eggs. Interestingly we observed unexpected hepatic lesions induced by S. haematobium adult male worms alone in the golden hamster, characteristic of schistosome eggs. Samples from liver, kidneys, lungs, bladder and gastrointestinal tract were collected during necropsy to evaluate injuries induced by S. haematobium. Notably we observed hepatitis in the liver of infected hamsters, no lesions were found in other organs. We also found liver fibrosis in infected hamsters. This study provides further experimental evidence for the role that schistosome worms, and their derived antigens, may play in the pathology of the infection and modulation of liver chronic inflammation in the murine model of schistosomiasis.