Development of new lateral-flow immunochromatographic strip using colloidal gold and mesoporous silica nanoparticles for rapid diagnosis of active schistosomiasis

Objective: To develop a new sandwich based lateral flow immunochromatographic strip for rapid detection of circulating Schistosoma mansoni antigen in serum and urine samples of patients with active schistosomiasis. Methods: This lateral flow immunochromatographic strip was prepared by using anti-Schistosoma mansoni soluble egg antigen monoclonal antibody conjugated gold nanoparticles (MAb-AuNPs) as antigen-detecting antibody, while crystalline material (MCM)-41-MAb bioconjugate was immobilized at the test line as antigen-capturing antibody. Both antigen capturing and detecting antibodies formed sandwich complexes with circulating Schistosoma mansoni antigen in the positive samples. Sandwich complexes immobilized at the test line gave distinct red color. The assay reliability was examined by using urine and serum samples of 60 Schistosoma mansoni infected patients, 20 patients infected with parasites other than Schistosoma, and 20 healthy individuals as negative controls. Results were compared with those obtained via sandwich enzyme linked immunosorbent assay (ELISA). Results: The detection limit of circulating Schistosoma mansoni antigen by lateral flow immunochromatographic strip was lower (3 ng/mL) than the detection limit by ELISA (30 ng/mL). The sensitivity and specificity of lateral flow immunochromatographic strip in urine samples were 98.3% and 97.5%, respectively compared to 93.5% and 90.0% by ELISA. In serum samples, they were 100.0% and 97.5%, respectively compared to 97.0% and 95.0% by ELISA. The strip test took approximately 10 min to complete. Conclusions: This new lateral flow immunochromatographic strip offers a sensitive, rapid, and field applicable technique for diagnosis of active schistosomiasis.

Acute upper gastrointestinal bleeding in Kasr El-Aini gastrointestinal endoscopy unit, Cairo, Egypt from the years 1991 to 2000

Acute upper gastrointestinal bleeding [UGIB] is a common and potentially serious problem in Egypt and worldwide. It remains a common cause for hospital admission with constant mortality despite advances in therapy and patient care. Endoscopy is the primary tool for diagnosis of UGIB. The present study aimed at investigating the etiology of UGIB in Egypt and whether any change has occurred in the period from 1991 to 2000. Files of patients undergoing upper GI endoscopy in one of the largest endoscopy units in Egypt [Kasr-El-Aini hospital, Cairo University, Cairo] during this period have been reviewed and analyzed. From 11567 patients who underwent upper GI endoscopy, 1763 [15.2%] had active or recent UGIB, mostly in the form of hematemesis and melena. Most of these patients were males [64.5%] with no age predilection. The commonest finding in bleeding cases was esophagogastric varices [53.3%]. The risk of bleeding increased with the grade of varices and was highest [odds ratio= 11] in the presence of gastric extension of varices. Varices was the commonest finding in all age groups in both males and females although significantly commoner in males [60% vs. 41 %]. Erosive and non-erosive gastritis were the second common finding followed by duodenal ulcer and esophageal erosions [15.8%, 21.1 %, 13.6% and 11.1 %, respectively]. Esophageal varices were associated with one or more other lesions in 31 % of cases and were the only finding in 650 cases with UGIB. Compared to cases presenting with hematemesis, patients with melena alone [n = 195] had significantly lower prevalence of varices and higher prevalence of gastritis and duodenal ulcer. Analysis of findings in 1991 and 2000 revealed a similar pattern of endoscopic findings in cases with UGIB indicating that no significant change has occurred in the underlying medical diseases predisposing to UGIB. Results were discussed in comparison with previous Egyptian and foreign studies

Implication of genetic make-up on immunopathological responses in murine schistosomiasis mansoni

This work was designed to assess the effect of natural infection with S. mansoni cercariae or sensitization to soluble egg antigen [SEA] prior to infection on two strains of mice with different genetic make up [C57BL/6 and BALB/c]. The hepatic pathological and functional changes were evaluated. Splenic cytokine profiles and serum anti-SEA IgG were measured. In response to infection, the granuloma diameter was larger, the eosinophil counts were higher, serum anti SEA-lgG was greater, serum splenic cytokines [IL-2, IFN-gamma, IL-4 and IL-10] were higher in C57BL/6 than BALB/c. In response to SEA-sensitization, greater reduction in granuloma diameter, higher percentage of degenerated ova, normalization of liver function, and elevation of anti-SEA IgG were more obvious in C57BL/6 than BALB/c mice. The reduction of IL-4 relative to the parallel infected group was remarkable in C57BL/6 compared to BALB/c. Other cytokines levels were comparable in both mice strains. It is evident that the immuno-pathological responses in schistosomiasis are different according to the genetic make up of the host