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Abstract Background Praziquantel has been used as first-line drug for chemotherapy of schistosomiasis since 1984. Besides praziquantel, artemether and artesunate have also been used for the control of this infectious disease since late 1990s. In this article, we conducted a systematic review and meta-analysis to evaluate the antischistosomal efficacy of different medication strategies including monotherapy or combination therapies of these drugs. Results A number of 52 trials from 38 articles published in peer-reviewed journals before July 2011 were selected for analysis after searching the following literature databases: the Cochrane Library, PubMed/Medline, ISI Web of Science, Chinese Biomedicine Literature Database, and China National Knowledge Infrastructure. Our meta-analyses showed that a dosage of 30-60 mg/kg praziquantel compared with placebo produced a protection rate of about 76% (95% CI: 67%-83%) for treating human schistosomiasis, which varied from 70% to 76% with no significant differences among the subspecies S. haematobium, S. japonicum or S. mansoni. Protection rates were higher when praziquantel doses were elevated, as concluded from the nRCTs results: the protection rate of praziquantel at 40 mg/kg was 52% (95% CI: 49%-55%), and it increased to 91% (95% CI: 88%-92%) when the dosages were elevated to 60/80/100 mg/kg divided two or more doses. Multiple doses of artemether or artesunate over 1- or 2-week intervals resulted in protection rates of 65% to 97% for preventing schistosomiasis, and increased doses and shorter medication intervals improved their efficacies. Praziquantel and artemisinin derivatives (artemether or artesunate) in combination resulted in a higher protection rate of 84% (95% CI: 64%-91%) than praziquantel monotherapy for treatment. praziquantel and artesunate in combination had a great protection rate of 96% (95% CI: 78%-99%) for preventing schistosomes infection. Conclusions According to the results, praziquantel remains effective in schistosomiasis treatment, and multiple doses would improve its efficacy; meanwhile, praziquantel is also a good drug for preventing acute schistosomiasis morbidity. It's better to use multiple doses of artemether or artesunate with 1- or 2-week intervals for prevention against schistosome infection. Praziquantel and artemether or artesunate in combination perform better in treatment than praziquantel monotherapy, and they are especially suitable for treating the patients with repeated exposure to infected water.

Highlights: [•] Anti-CTLA-4 mAb favors the host to clear S. japonicum. [•] Anti-CTLA-4 mAb may bias and enhance Th1-type host immune responses. [•] Egg granuloma sizes in anti-CTLA-4 mAb-treated animals were significantly larger. [•] Tregs and CTLA-4 may exert synergistic effect on the immune evasion of S. japonicum. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of lipopolysaccharide (LPS)-induced B cell activation on the development of Schistosoma japonicum., Methods: Eighteen BALB/c nude mice deficient in T cells and 23 BALB/c SCID mice deficient in T and B cells were used in this study. Each was infected with 30 ± 1 S. japonicum cercariae. The nude (n=9, NL group) and SCID (n=12, SL group) mice then received 2-3 (every two weeks) intraperitoneal injections with LPS (100 μg/mL, 0.2 mL for each mouse). The remaining nude(n=9, N group) and SCID (n=11, S group) mice received PBS injection as control. The mice were sacrificed on days 28 and 36 after infection (n=4/5, 4/5, 5/6, 6/6 for N, NL, S and SL groups, respectively), and adult worms were collected by hepatic portal vein perfusion. The collecting rate of the adult worms was calculated, the body-length measured, and pairs of worms recorded. The liver tissue was collected and digested with 5% KOH, and the number of eggs per gram of liver tissue was calculated. The levels of TGF-β, IFN-γ and IL-10 in peripheral blood were evaluated. Spleen cell suspension was prepared for detecting the proportion of regulatory B cells (Bregs) in splenic lymphocytes., Results: On day 28 after infection, the body-lengths of male worms in NL and N groups were (7.65±2.85) mm and (5.28±1.64) mm (P<0.01), and those of female worms were (9.64±1.99) mm and (7.49±1.63) mm (P<0.01), respectively. On day 36 after infection, the number of eggs per gram of liver tissue was significantly higher in the NL group than in the N group (1 088±297 vs 715±404, P<0.05), and significantly lower in the SL group than in the S group (217±33 vs 573±160, P<0.01). The proportions of CD(hi)CD5(+)CD19(+) Bregs in N group on days 28 and 36 after infection were (12.73±0.96)% and (37.15±3.04)% (P<0.05), respectively, with no significant difference with that of NL group. The serum levels of TGF-β and IFN-y on day 28 after infection were significantly different between N and NL groups (TGF-β, 101.75±46.72 vs 260.90±45.34 pg/mL; IFN-y, 7.91±1.62 vs 14.11±3.72 pg/mL, both P<0.01). Similarly, significant difference was found for the plasma level of IL-10 on day 36 after infection between the S and N groups (41.85±3.14 vs 66.25±4.16 pg/mL, P<0.01), and between the SL and NL groups (44.48±3.87 vs 72.22±17.76 pg/mL, P<0.01), but not between the LPS groups and the control groups., Conclusion: LPS can induce the release of cytokines (e.g. TGF-β) from B cells of mice infected with S. japonium, to facilitate the early development of adult female and male worms.

Recent studies found that B cell subsets and their factors have double effects on anti- and aiding schistosome infection. This article summarizes the research progress of positive and negative immunoregulation of schistosome infection involving B lymphocytes, antibody and regulatory B cells (Bregs) relating cytokines (IL-10, IL-7 and TGF-β).

With the social and technological development, new understandings have been emerged for the research development of the control of parasitic diseases. The present review argues that: the traditional point of view for the control of parasitic diseases, eliminating parasites/media, should be updated. For the long-term interests of science and human perspective, biological diversity, including the parasite biodiversity, and ecological environment should be paid much more attention during the control of parasitic diseases. The leading role of society, economy and culture should be fully developed in the control of parasitic diseases with the progress of scientific and technology, to find a final way of sustainable development in the control of parasitic diseases.

The specific molecular targets of schistosomula have been investigated for being new vaccine candidates. The mechanism of the growth and development of the skin-stage, lung-stage and hepatic schistosomula may be related to the immune regulation, signal transduction, sex-differentiation and apoptosis. Actin et al are important molecules which related to the growth and development of schistosomula.

To clone partial ORF of SjBMP and to construct the recombinant SjBMP-pET-28a(+) plasmids, and then to transform them into the competent cells E. coli BL21 (DE3), finally a positive clone was used to be induced by IPTG. The bacterial aggregates with target protein expressed as inclusion bodies were purified by the methods of Ni(2+)-NTA affinity purification under denaturation condition and SDS-PAGE gel extraction. The purified protein was used to immune rabbits and make antiserum against the SjBMP, and the antiserum were then used to identify the rSjBMP by Western blotting. The target protein obtained by Ni(2+)-NTA Agarose affinity purification was not pure with unspecific proteins, but the protein further purified by SDS-PAGE gel extraction and the dialysis bag horizontal electrophoresis was quite pure, and the recovery rate was more than 11.0%. Meanwhile, Western blotting was used to identify the recombinant SjBMP protein by antiserum, only a specific single strip appeared, which suggested the protein purified by this method kept its antigenicity, and could be used for common immunological studies. Therefore, the SDS-PAGE gel extraction combining with electroosmosis and dialysis recycling are good and easy to purify the inclusion body proteins.

Objective: To study the effects of male worm extraction on the proliferation and metabolic activity of cultured vitelline cells from Schistosoma japonicum., Methods: The 28-day S. japonicum worms were harvested by perfusion. The male and female of them were isolated after asepsis separately. The vitelline glands of female worms were isolated, and the vitelline cells were harvested by the cold digestion, then they were inoculated with the moist system method on the walls of culture flasks. The cultured vitelline cells were randomly divided into test and control groups. The cells in the control group were cultured in routine media and those in the test group were cultured in routine media containing male worm extraction of the concentration of 100 microg/ml. When cultured for 7 days, the cells in both groups were prepared for observation under a transmission electron microscope., Results: In the test group, the numbers of mature vitelline cells were more than those in the control group; the cytoplasm and nucleus of mature vitelline cells were homogeneous stain. The nucleolus and rough-surfaced endoplasm reticula were clear, the intervals of vitelline globules were clear and their numbers could be counted. The number of mitochondria was small and the electron density was low; abundant rough-surfaced endoplasm reticula were found in the immature vitelline cells. There were more immature vitelline cells in the control group. The cytoplasm of the cultured vitelline cells took changes of balloon, especially in mature vitelline cells, vitelline globules fused each other, no mitochondria were found; in immature vitelline cells, the space between vitelline globules and the membrane surrounding them broadened gradually and vitelline globules were released and uncovered; rough-surfaced endoplasmic reticula enlarged, space vacuolated and the ribosomes dropped; and the number of lipid increased., Conclusion: The S. japonicum male worm extraction can stimulate the development and survival of the cultured vitelline cells.

Objective: To study in vitro the effect of 5-hydroxytryptamine (5-HT) on the motility and length of primary sporocysts of Schistosoma japonicum and select the optimal concentration and time of 5-HT., Methods: Eggs of S. japonicum were harvested from livers of the infected mice 6-8 weeks after infection, which were then incubated with water. The miracidia were axenically cultured in 1/2 RPMI 1640 containing 10% calf serum and a moderate amount of antibiotics (100 U/ml penicillin G and 100 microg/ml streptomycin) for 48 hours. They became mother sporocysts and were divided into two groups. Parasites in the first group were treated by 5-HT under concentrations of 0, 0.1, 1, 10, 100 and 1000 micromol/L for 48 hours, respectively. Those parasites in the second group were treated by 5-HT of 10 micromol/L for 0.16, 6, 24 and 48 hours, respectively. The motility, length and succinic dehydrogenase (SDH) activity of the parasites were measured under Olympus microscope., Results: Along with the increase of 5-HT concentration, the motility and length of the mother sporocysts all increased gradually. With the 5-HT concentration of 10 micromol/L, both of them reached a maximum value, being (65.6 +/- 1.5)% and (131.4 +/- 9.2) microm respectively. Meanwhile, along with the prolongation of treatment time, the motility and length also increased gradually. The motility reached a maximal value at 24 hours post-treatment. So did the length and SDH activity of the parasites at 48 hours post-treatment., Conclusion: 5-HT shows a significant effect on the motility and length of mother sporocysts of S. japonicum and its optimal concentration is 10 micromol/L under in vitro conditions.

Reactive oxygen species (ROS), generated in the metabolism process of aerobic organisms, can induce oxidative damages in the body. These organisms are all equipped with an excellent defense system to protect themselves and antioxidant enzymes play an important role in the system. Parasitic trematodes have to eliminate ROS not only from themselves but also from the immune system of their hosts. To better understand the structures and specialties of the antioxidant enzymes in trematodes is conducive to the study on reproductive physiology of trematode and on drug and vaccine development. This paper summarizes the research progress on the family of antioxidant enzymes in trematodes including glutathione peroxidase (GPx), superoxide dismutase (SOD) and peroxiredoxin (PRx) in the past decades.

Objective: To develop a method for primary culture of cells from Oncomelania hupensis liver, and to observe the distribution of succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) in the cultured cells., Methods: O. hupensis was anatomized to separate the liver. Livers were soaked in 0.2% benzalkonium bromide and washed by physiological saline containing antibiotics in turns. Cells from the liver were harvested by mechanical mulling and filtering. The isolated cells were then incubated with methods of the combination culture and standing suspension culture, respectively. The culture medium for the cells was a mixture of Medium 199 (50 ml), 0.3% lactoalbumin hydrolysate dissolved in a balanced salt solution (BBS, 30 ml), and fetal calf serum (FCS, 20 ml) containing a moderate amount of antibiotics (100 IU/ml penicillin, 100 microg/ml streptomycin and 50 microg/ml kanamycin) at pH 7.2-7.4 under the temperature of 26.5 degrees C. The cells were stained by using Giemsa and Pearson methods (for SDH and LDH respectively) to observe the shape of cultured cells and enzyme distribution in cells. The living and stained cells were microscopically observed., Results: Under microscope, the attached cells incubated with method of the combination culture showed round, elliptic, triangular and irregular shapes, with more round and elliptic cells. The size was approximately (4-16) microm x (6-20) microm in average. The clustered cells with an unclear nucleus and abundant and lucid cytoplasm were smaller than diffused cells with a large, obvious nuclei and less cytoplasm. Degeneration was observed after culturing for 5-7 days. The cultured cells could be divided into two types based on the color shown after Giemsa staining. The first type cells showed blue cytoplasm and mauve nuclei while the second type cells were opposite. There were blue granules in different sizes and shade in the cytoplasm after SDH and LDH staining. It was difficult for the cells to attach the wall of the culture flask using method of the standing suspension culture. The shape of the cultured cells were almost round with unclear nuclei, and the size was about (4-6) microm x (6-8) microm in average. The cells incubated with the standing suspension method were found to be contaminated after culturing for 3 days., Conclusion: The combination culture method is suitable for primary culture of the cells from O. hupensis liver and the cells show activities of both SDH and LDH in cytoplasm.

Proteomics is an important high throughout method in modern life science. In this paper, the definition, background and methods used in proteomics were introduced, and the last part was focused on its application in parasitology.

Objective: To investigate the effect of chronic infection of Toxoplasma gondii on the spatial learning and memory capability in mice., Methods: Toxoplasma tachyzoites (RH strain) were reanimated at 37 degrees C after 15 days' storage at -20 degrees C, and injected intraperitoneally to mice of the experimental group each with 7.7 x 10(5). Normal saline was given to the control group, 0.5 ml per mouse. Two months later, all mice were tested in the Morris Water Maze. Smears of the mice brain homogenate and pathological sections were examined., Results: (1) The density of cysts in the brain homogenate was 15/HP, and there was no evident pathological change in the hippocampus and adjacent areas of mice in the brain in the experimental mice. (2) Latency to platform, cumulative distance to the platform, total distance traveled in both experimental and control groups decreased significantly with the increase of training days (P < 0.01). The latency and cumulative distance in experimental group were significantly longer than that of the control group (P < 0.01). (3) The searching strategy of mice in the experimental group was significantly different from that of the control group., Conclusion: Toxoplasma tachyzoites can induce chronic infection in mice and the infection can damage at some extent the spatial learning and memory capability of mice.

Objective: To investigate the change of biological features of macrophages after transfected by Toxoplasma gondii GRA-1 genes (P24)., Methods: The transfected cells Cyto-P24-RAW264.7, Nuc-P24-RAW264.7, Mito-P24-RAW264.7 and ER-P24-RAW264.7 were studied by RT-PCR to determine the P24-mRNA expression. Growth features of the cells were examined with microscopy and the cell growth curve was developed., Results: In four cell lines, expression of ER-P24-RAW 264.7 was found to be higher than the other three, and there was no P24-mRNA expression in either of the cells without P24 insert. The attachment and the proliferation of ER-P24-RAW264.7 were more rapid than normal RAW264.7., Conclusion: Transfection of mouse macrophages ER-RAW264. 7 strain with T. gondii P24 gene leads to a prominent change of biological features in the studied cell line.