789 research outputs found
Receptor for Fc on the surfaces of schistosomes
Schistosoma mansoni masks its surface with adsorbed host proteins including erythrocyte antigens, immunoglobulins, major histocompatibility complex class I, and beta (2)-microglobulin (beta (2)m), presumably as a means of avoiding host immune responses, How this is accomplished has not been explained. To identify surface receptors for host proteins, we biotinylated the tegument of live S, mansoni adults and mechanically transformed schistosomula and then removed the parasite surface with detergent, Incubation of biotinylated schistosome surface extracts witt l human immunoglobulin G (IgG) Fc-Sepharose resulted in purification of a 97-kDa protein that was subsequently identified as paramyosin (Pmy), using antiserum specific for recombinant Pmy, Fc also bound recombinant S. mansoni Pmy and native S. japonicum Pmy, Antiserum to Pmy decreased the binding of Pmy to Fc-Sepharose, and no proteins bound after removal of Pmy from extracts. Fluoresceinated human Fe bound to the surface, vestigial penetration glands, and nascent oral cavity of mechanically transformed schistosomula, and rabbit anti-Pmy Fab fragments ablated the binding of Fc to the schistosome surface, Pmy coprecipitated with host IgG from parasite surface extracts, indicating that complexes formed on the parasite surface as well as in vitro. Binding of Pmy to Fe was not inhibited by soluble protein A, suggesting that Pmy does not bind to the region between the CH2 and CH3 domains used by many other Fc-binding proteins. beta (2)m did not bind to the schistosome Fc receptor (Pmy), a finding that contradicts reports from earlier workers but did bind to a heteromultimer of labeled schistosomula surface proteins, This is the first report of the molecular identity of a schistosome Fc receptor; moreover it demonstrates an additional aspect of the unusual and multifunctional properties of Pmy from schistosomes and other parasitic flatworms
Echinococcus granulosus Infection and Options for Control of Cystic Echinococcosis in Tibetan Communities of Western Sichuan Province, China
Human cystic echinococcosis (CE) is highly endemic in Tibetan regions of Sichuan. As part of a control program for CE in Datangma district, Ganzi County, necropsy of strays and coproantigen-ELISA of all dogs was carried out prior to and post-drug treatment to determine the efficacy of the treatment for control. Examination of sheep/goats and yaks was undertaken to determine the baseline transmission pressure to dogs. The necropsy results indicated no apparent significant change in the overall prevalence of E. granulosus in unwanted dogs after 5 years of 6-month treatment. In contrast, there was a highly significant decrease in Echinococcus prevalence in domestic/stray dogs after the 5-year treatment program shown by coproantigen-ELISA. This indicated a decreasing but continuing risk for re-infection of dogs resulting from high infection pressure from the numerous infected domestic animals. DNA genotyping indicated the presence only of the sheep strain (G1) of E. granulosus in the study area. A combination of livestock vaccination with the highly effective Eg95 vaccine and dog drug treatment, targeting two critical points of the parasite life-cycle, would avoid the conflicts of religion or local culture and achieve the goal of hydatid control in the long term in the area
Diagnosis and management of schistosomiasis
The authorsā studies on schistosomiasis have received financial support from various sources including: the UNICEF/UNDP/World Bank/WHO Special Program for Research and Training in Tropical Diseases; the National Health and Medical Research Council of Australia; the Wellcome Trust (UK); the Sandler Foundation (USA); the Dana Foundation (USA); and the National Institute of Allergy and Infectious Diseases
Oriental schistosomiasis with neurological complications: case report
We describe a case of cerebral schistosomiasis, caused by Asian (oriental) Schistosoma japonicum trematode blood flukes, in a young Chinese patient and its management. We also provide a brief update for physicians on the clinical features, diagnosis and treatment of schistosomiasis, with particular emphasis on neuroschistosomiasis, the most severe clinical outcome associated with this parasitic infection
Preparation of polymeric diacetylene thin films for nonlinear optical applications
A method for producing polymeric diacetylene thin films having desirable nonlinear optical characteristics has been achieved by producing amorphous diacetylene polymeric films by simultaneous polymerization of diacetylene monomers in solution and deposition of polymerized diacetylenes on to the surface of a transparent substrate through which ultraviolet light has been transmitted. These amorphous polydiacetylene films produced by photo-deposition from solution possess very high optical quality and exhibit large third order nonlinear optical susceptibilities, such properties being suitable for nonlinear optical devices such as waveguides and integrated optics
Case studies emphasising the difficulties in the diagnosis and management of alveolar echinococcosis in rural China
<p>Abstract</p> <p>Background</p> <p>Human alveolar echinococcosis (AE) is caused by the accidental ingestion of the eggs of the fox tapeworm <it>Echinococcus multilocularis</it>. AE occurs frequently in rural western China due to the poor levels of hygiene, the close contact of people with dogs, and the lack of appropriate facilities for the correct and rapid diagnosis of the disease.</p> <p>Findings</p> <p>We describe a case of a patient with hepatic AE, and AE metastases of the brain. She was mistakenly diagnosed with suspected undifferentiated metastatic cancer of the liver and brain, and with a pulmonary bacterial infection, but was subsequently correctly diagnosed during a follow-up field survey for echinococcosis. The diagnosis of brain AE was confirmed by pathological examination of tissue biopsies removed during neurosurgery. We also briefly describe other symptomatic and asymptomatic AE cases, identified by chance, likely due to the inadequate facilities available in rural communities in China for AE diagnosis and management, since the rapid and accurate diagnosis of metastatic AE requires a high level of expertise in the appropriate diagnostic procedures.</p> <p>Conclusions</p> <p>This report highlights the necessity for an upgrade in the diagnosis, treatment, prevention and control of AE in rural China.</p
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