Possible associations of rectal carcinoma with Schistosoma japonicum infection and membranous nephropathy: a case report with a review.
(9/272)
We report the first case of rectal carcinoma associated with S. japonicum and membranous nephropathy. A 57-year-old Japanese man noticed narrowing of his feces. He had lived in Yamanashi prefecture, an endemic area of S. japonicum. He had suffered from nephrotic syndrome for about 1 year. Barium enema study showed a severe stricture in the upper rectum and biopsy specimens from the tumor demonstrated well differentiated adenocarcinoma and many ova of S. japonicum. Sonography of the liver showed a network pattern and a linear high echoic area. Low anterior resection with incisional biopsy of the liver and the right kidney was performed. Histopathological findings showed well differentiated adenocarcinoma and schistosomal ova. The total number of ova in the resected colon amounted to 15,133, consisting of 2243 inside and 12,890 outside the carcinoma. The nearer to the carcinoma the area was, the higher was the density of ova. The findings of light microscopy and electron microscopy of the biopsy specimen from the kidney were compatible with membranous nephropathy (stage II). This case suggests that schistosomal ova have some effect on carcinogenesis and nephrotic syndrome. In patients with nephrotic syndrome of unknown cause, especially in inhabitants of endemic areas of S. japonicum, gastrointestinal malignancy should be ruled out as an etiological factor. Sigmoidoscopy would be useful for colorectal carcinoma surveillance in S. japonicum patients. (+info)
Tissue responses in experimental schistosomiasis japonica in the pig: a histopathologic study of different stages of single low- or high-dose infections.
(10/272)
The tissue responses of pigs exposed to either 100 or 2,000 Schistosoma japonicum cercariae were examined at 4, 11, 17, and 24 weeks postinfection (PI) to explore the pig as an animal model for pathologic aspects of human schistosomiasis japonica. Egg granulomas were present in the liver, intestine, and occasionally in the lungs from 11 weeks PI. There were also many free eggs and early exudative reactions to eggs in the intestine. At 11 weeks PI, pigs in the higher dose group showed marked periportal and septal fibrosis with minimal parenchymal destruction. Thereafter, lesions regressed spontaneously as the pigs underwent a self-cure. The lower dose group showed only mild lesions throughout the study. The degree of hepatic fibrosis was correlated with the density of eggs and granulomas in liver tissue. The results indicate that the pig would be particularly useful for studies of the development and resolution of schistosomal hepatic fibrosis, and also for investigations of the mechanisms behind the self-cure phenomenon. (+info)
Upper genital schistosomiasis mimicking an ovarian tumour.
(11/272)
Schistosomiasis is a widely prevalent disease in the world and usually involves the gastro-intestinal and urinary tract. The involvement of the female genital tract has been well-established in S. haematobium infections and is rare with S. japonicum infections. This case involves a Filipino female who was admitted to the University Hospital Kuala Lumpur for right iliac fossa pain and was diagnosed initially as acute appendicitis. Ultrasound showed a multi-septated pelvic cyst leading to a provisional diagnosis of ovarian torsion. Intraoperatively a right parovarian cyst was detected and removed. Histology revealed a congested cyst wall with areas of haemorrhage with several viable and calcified eggs of S. japonicum measuring 85 microns x 62 microns. Within the cystic cavity blood admixed with eggs were seen. Confirmation was carried out by using the indirect haemagglutination (IHA) test. This is a first report of upper genital schistosomiasis mimicking an ovarian tumour. (+info)
Schistosomiasis in the People's Republic of China: prospects and challenges for the 21st century.
(12/272)
Schistosomiasis japonica is a serious communicable disease and a major disease risk for more than 30 million people living in the tropical and subtropical zones of China. Infection remains a major public health concern despite 45 years of intensive control efforts. It is estimated that 865,000 people and 100,250 bovines are today infected in the provinces where the disease is endemic, and its transmission continues. Unlike the other schistosome species known to infect humans, the oriental schistosome, Schistosoma japonicum, is a true zoonotic organism, with a range of mammalian reservoirs, making control efforts extremely difficult. Clinical features of schistosomiasis range from fever, headache, and lethargy to severe fibro-obstructive pathology leading to portal hypertension, ascites, and hepatosplenomegaly, which can cause premature death. Infected children are stunted and have cognitive defects impairing memory and learning ability. Current control programs are heavily based on community chemotherapy with a single dose of the drug praziquantel, but vaccines (for use in bovines and humans) in combination with other control strategies are needed to make elimination of the disease possible. In this article, we provide an overview of the biology, epidemiology, clinical features, and prospects for control of oriental schistosomiasis in the People's Republic of China. (+info)
Susceptibility of Schistosoma japonicum to praziquantel in China.
(13/272)
To look for possible evidence of the development of resistance in Schistosoma japonicum to praziquantel, we conducted a field study in China. During the non-transmission period of schistosomiasis a random sample of 2860 individuals from six villages in three provinces of China were examined using a parasitological stool examination. Of the 372 stool-positive subjects, 363 subjects were treated with a single oral dose of 40 mg/kg of praziquantel. Six to Seven weeks after treatment, of 334 subjects examined using the same stool examination, stool-negative results were found in 319 patients which represents a 95.5% parasitologic cure rate. Fifteen subjects still excreting eggs were treated a second time with the same dose of praziquantel. All stool samples, including those from participants re-treated with praziquantel, were re-examined 12 weeks after the first treatment and no stool-positive subjects were found. The results indicate that there was no evidence for reduced susceptibility of S. japonicum to praziquantel despite its extensive use in the main endemic areas of China for more than 10 years. The in vitro responses to praziquantel of cercariae, miracidia and eggs of S. japonicum compared with S. mansoni demonstrate that the cercariae, miracidia and eggs of S. japonicum are more sensitive to praziquantel than those of S. mansoni. More sensitive worms would be less likely to develop resistance and this could explain why no evidence for resistance was found in S. japonicum in China. (+info)
A rapid one-step method of EIA for detection of circulating antigen of Schistosoma japonicum.
(14/272)
OBJECTIVE: To establish a highly sensitive serologic method for detecting the circulating antigen of Schistosoma japonicum for the diagnosis of this disease and the evaluation of drug therapy effect. METHODS: A set of complex support made of polyvinyl-chloride (PVC) film slide, adsorbed with specific antibody, was used to test serum samples collected from cases with schistosomiasis japonica, by adding specific enzyme conjugate and substrate tetra-methyl benzidine (TMB) with 3% H2O2 in 10:0.1, developed or prepared in our laboratory. Tests were carried out with the set on cases with malaria, paragonimiasis, clonorchiasis, visceral leishmaniasis and cysticercosis as well as normal individuals as control. Serum sample of 50 microliters was used in each test and reacted with reagents at room temperature for 30 minutes. The color of positive reaction was blue while negative reaction was colorless. RESULTS: Positive rate among cases with schistosomiasis japonica was 100% (45/45) in acute stage, 94.8% (530/559) in early chronic stage and 52.4% (66/126) in late stage. False positive reaction was found neither among all normal individuals (0/513), nor among cases of 155 with malaria, 120 with clonorchiasis, 24 with visceral leishmaniasis and 110 with cysticercosis, except one among 29 cases with paragonimiasis (1/29). CONCLUSIONS: The rapid one-step enzyme immunoassay (EIA) to detect circulating schistosome antigen (CSA) has been well established in our laboratory with high sensitivity and good specificity as well as reproducibility. The reaction result can be read easily even in field conditions without power supply. Moreover, the assay is time-saving, simple to handle and suitable for the diagnosis of schistosomiasis japonica and evaluation of drug therapeutic effect in practice in the control program of the disease. (+info)
Immunological characteristics of natural resistance in Microtus fortis to infection with Schistosoma japonicum.
(15/272)
OBJECTIVE: To explore the immunological characteristics of natural resistance to Schistosoma japonicum infection in Microtus fortis (MF) living in the Dongting Lake area. METHODS: Passive transfer of sera from uninfected laboratory bred MF (BMF) to albinao mice (AM) was performed to observe the acquired protection. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunoblotting (ELIB) methods were used to recognize 4 different life-cycle stage antigens of S. japonicum by sera from wild MF (WMF), BMF, BMF13 and BMF19. Tests were also performed on in vitro killing effect of sera and/or lymphocytes from BMF and WMF to schistosomulae; quantitative determination of C3 and C4 by immunoturbidometry, and interleukin-4 (IL-4) and antibodies to the 4 stage antigens in sera from WMF, BMF and infected BMF by ELISA. RESULTS: Compared with the control group, stool eggs per gram (EPG) of AM in the test group was significantly reduced by 81.54%, miracidium hatching rate, by 50.67%, liver egg counts, by 72.07%, the diameter of hepatic egg granuloma, by 70.39 microns. Western blotting probed with the 4 MF sera all revealed 7 specific bands for SSA, 3 for AWA and SEA, but none for CA antigens. The sera and/or lymphocytes from WMF and BMF gave obvious killing effects on schistosomulae with an adjusted death rate of 64.12%-78.83%. The levels of "natural antibodies" produced by MF to S. japonicum were in the following order: anti-SSA > anti-AWA > anti-SEA > anti-CA, all of which increased significantly after the infection. Serum levels of C3, C4 and IL-4 in uninfected BMF were significantly higher than those in AM. After infection, levels of C3 and C4 were further increased respectively by 72.83% and 295.49% in the 4th week and IL-4 by 303.83% in the 9th day. CONCLUSIONS: Immunological characteristics of innate resistance in M. fortis to S. japonicum infection were existed with no significant difference between WMF and BMF. (+info)
DNA vaccine pCD-Sj32 and its efficacy of protective immunity against infection of Schistosoma japonicum.
(16/272)
OBJECTIVE: To study protective immunity afforded by murine immunization with DNA vaccine of Schistosoma japonicum (S. japonicum) as measured by reduction in worm burden and host antibody, cytokines. METHODS: DNA vaccine pCD-Sj32 was constructed, identified and expressed. pCD-Sj32 could induce substantial protective immunity against infection of S. japonicum in BALB/c mice. The best efficacy can be produced with one injection of 100 micrograms DNA into the quadriceps muscle, combined with challenge for 8 weeks after immunization. T lymphocyte subsets of CD8+, IL-2. TNF and IFN-gamma of experimental animal could play important roles in regulating immune functions of schistosomiasis. RESULTS: High titre of specific antibody IgG could be induced by vaccinated with pCD-Sj32, and antibody can mediate macrophage to produce ADCC effects in vitro. CONCLUSION: pCD-Sj32 may represent a new approach to developing subunit vaccine. (+info)