Phytoremediation of heavy metals under an oil crop rotation and treatment of biochar from contaminated biomass for safe use.

The disposal of contaminated plants limits the use of phytoremediation. Therefore, the disposal of contaminated sunflower was investigated after determining the phytoremediation of heavy metals under an oil crop rotation of sunflower (Helianthus annuus L)-sesame (Sesamum indicum L.). In the field experiment, the extraction efficiency of sunflower-sesame rotation was 0.07% for lead (Pb); 1.37% for zinc (Zn); 1.10% for copper (Cu); and 6.12% for cadmium (Cd). Contaminated sunflower stems were pyrolyzed at different temperature. The biochar produced at 300 °C was extracted in a two-step process (acid-extraction from biochar and metals precipitation in alkaline condition). At pH = 1, 65.67% of the Cd and much potassium (K) were extracted. After acid-extraction, adjust the pH of filtrate to 10, metals were precipitated and then separated from the K-enriched solution. Therefore, pyrolysis can process contaminated residues, and the biochar extracts can be reutilized as fertilizer to off-site crop production. Thus, an oil crop-rotation system, in addition to creating economic benefits, can be used by local farmers in contaminated soils.

Recycling EDTA solutions used to remediate metal-polluted soils.

The objective of this research was to investigate the recycling of ethylenediamine-tetraacetic acid (EDTA) used for the removal of trace metals from contaminated soils. We successfully used Na2S combined with Ca(OH)2 to precipitate the trace metals allowing us to recycle the EDTA. The results of batch and column leaching experiments show that both Ca-EDTA and Na-EDTA are powerful chelating agents with a similar soil remediation potential. The major advantage of Ca-EDTA is the preservation of soil organic matter. We found that Na2S was capable of separating the metals Cd, Cu and Pb from EDTA; however, the precipitation of Zn required the addition of Ca(OH)2. After reusing the reclaimed EDTA seven times, over a 14-day period, EDTA reagent losses ranged from 19.5% to 23.5%. Successive washing cycles enhanced the removal of trace metals from contaminated soils. The metal sulfide precipitates contain high concentrations of metals and could potentially be recycled.

Epidemiological and morbidity assessment of Schistosoma japonicum infection in a migrant fisherman community, the Dongting Lake region, China.

We assessed the epidemiology and morbidity related to Schistosoma japonicum infection by both parasitological (Kato-Katz method and miracidium hatching test) and ultrasound examination in a migrant fisherman community (n = 106) from the Dongting Lake region in China in 2001. A prevalence of 69.8% and a mean infection intensity of 66.5 eggs per gram (epg) were recorded for this group. Males had a higher level of infection (77%) and intensity (92.2 epg) compared with females (58% and 28.6 epg, respectively). Subjects aged 11-20 years had the highest prevalence of infection (91%) and the heaviest infection intensity (85.3 epg) among all age groups. Twenty-six percent of the subjects had not been treated previously for schistosomiasis. Parenchymal fibrosis (> or = stage II) detected by ultrasound and spleen enlargement (or splenectomy) occurred in 37% and 9% of subjects, respectively. Portal vein dilation was detected in 18% subjects, and 58% (11/19) of those patients with portal vein enlargement were shown to have parenchymal fibrosis (> or = stage II). These results indicate that S. japonicum infection and related morbidity in mobile fisherman is still unacceptably high despite the fact that China has implemented a Schistosomiasis Control Project financed by a World Bank Loan for a period of 8 years since 1992. Clearly, new approaches for schistosomiasis control, especially in communities like these mobile fishermen, should be explored.

[Cloning and characterization of three novel genes encoding transmembrane proteins of Schistosoma japonicum].

OBJECTIVE: To clone and analyze novel antigen molecules of Schistosoma japonicum (Sj), and to provide effective vaccine candidate antigens against schistosomiasis japonica. METHODS: Sj adult cDNA library was screened using sera of mice infected with Trichinella spiralis (Ts) and the inserts of positive clones were specifically amplified by PCR. The positive clones were sequenced and the sequence data were analyzed using Nucleotide BLAST software of NCBI and Expert Protein Analysis System of Swiss Institute of Bioinformatics. RESULTS: Nine positive clones were obtained after three rounds of immunoscreening. The size of these inserts ranged from 0.6 kb to 2.1 kb. Among five novel genes, Sj-Ts1, Sj-Ts3 and Sj-Ts5 (GenBank accession number: AY005816, AF299080 and AY024352, respectively) encode trans-membrane proteins with 83, 83 and 233 amino acids, respectively. Sj-Ts1 protein predicted contains one possible trans-membrance helix, one N-myristoylation site, two phosphorylation sites for protein kinase C and one for tyrosine kinase, Sj-Ts3 protein contains two possible transmembrance helices and one casein kinase II phosphorylation site, whereas Sj-Ts5 protein has five possible transmembrance helices, one N-glycosylation site, one N-myristoylation site, two phosphorylation sites for cAMP- and cGMP-dependent protein kinase and four for protein kinase C and one for casein kinase II. CONCLUSION: Three novel genes encoding three transmembrane proteins might be developed as new vaccine candidates against Sj infection.

[Comparative study on the efficacy of KLH-IDT and SEA-IDT in diagnosing schistosomiasis japonica].

Thirty-three egg-positive subjects and 32 egg-negative subjects were tested synchronously by KLH-IDT and SEA-IDT in endemic area of schistosomiasis. Compared with stool examination, the positive coincidence rate of KLH-IDT and SEA-IDT were 90% and 100%, respectively, which showed no statistical significance(P > 0.05), and the negative coincidence rate of KLH-IDT and SEA-IDT were 71.9% and 25%, respectively, which showed statistical significance(P < 0.01). Of the 31 egg-negative subjects, 9 subjects showed positive by both SEA-IDT and KLH-IDT, and 15 subjects showed positive by SEA-IDT but negative by KLH-IDT. Both double positive subjects and single positive subjects were examined further by miracidium hatching test, there were 2 subjects showing positive among the 9 double positive subjects. In addition, of 27 subjects that had been treated one year before, only 6 subjects showed positive by KLH-IDT, the reversion rate was 77.8%; whereas, the reversion rate was 22.2% (6/21) by SEA-IDT. The results suggest that KLH-IDT has high value in diagnosing schistosomiasis, particularly shows a potential in assessing therapeutic efficacy of schistosomiasis.

[Evaluation of Schistosoma japonicum tegumental membrane antigen (SjMAg) in immunodiagnosis and efficacy assessment].

OBJECTIVE: To evaluate the specificity and sensitivity of SjMAg in detecting specific antibodies in sera of patients with schistosomiasis japonica and in assessing therapeutic efficacy. METHODS: SjMAg-ELISA was used to determine the specific IgG and IgG4 in sera of patients with schistosomiasis japonica at different time points after chemotherapy. RESULTS: SjMAg-ELISA was as sensitive and specific as SEA-ELISA. The negative conversion rate of IgG detected by SjMAg-ELISA 12 months after treatment was 80.0%, being significantly higher than 43.3% by SEA-ELISA. The negative conversion rate of IgG4 detected by SjMAg-ELISA 12 months after treatment was 93.3%, being significantly higher than 60.0% by SEA-ELISA. The negative conversion rates of IgG and IgG4 2 yr after treatment were 92.9% and 97.6% respectively. CONCLUSION: SjMAg-ELISA is comparable to SEA-ELISA in diagnosing schistosomiasis japonica and is more effective in assessing therapeutic efficacy.

[Effects of thyroxine and methimazolum on monamine transmitters in preoptic/anterior hypothalamic area and peripheral serum in rats].

The contents of monamine transmitters in preoptic/anterior hypothalamic (PO/AH) area and in the serum of rats injected with thyroxine (T4, 1 mg/100 g body wt/d, for 10 d, hypodermic i.) and fed with methimazolum (10 mg/100 g body wt/d, for 15 d) were assayed by high pressure liquid chromatography with electrochemical detector (HPLC-ECD). It was found that the content of dopamine and homovanillic acid in PO/AH area showed significant increase (P less than 0.01) associated with a slight rise (P greater than 0.05) of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), and with no change of norepinephrine in the thyroxine group. After fed with methimazolum, the content of norepinephrine decreased significantly (P less than 0.05), but no obvious changes occurred in dopamine, homovanillic acid, 5-HT and 5-HIAA. By synchronous analysing of monamine transmitters in peripheral serum, it was showed that there was no significant linear relationship between the changes of monamine transmitters in the brain and in the serum. The correlation between thyroxine and methimazolum on the content of monamine transmitters and on the change of body temperature was also discussed.

[Common antigenic components in soluble antigens shared by Schistosoma japonicum eggs and Paragonimus westermani adult worms].

Using enzyme-linked immunoblot technique (ELIB), the antigenic protein components of water-soluble and urea-soluble antigens of Schistosoma japonicum eggs (JSEA, JEAU) and Paragonimus westermani adult worms (PAA, PAA-U) were analysed. The results showed that in both JSEA and JEA-U, 8 and 3 bands of polypeptides could be recognized by sera from patients with schistosomiasis japonica (Sj). In both PAA and PAA-U, there were 9 and 2 bands of polypeptides respectively, which could be recognized by sera from patients with pagumogonimiasis skrjabini (Ps). The components of 36/37kDa in PAA and 20/21 kDa in JSEA were identified to be shared antigenic fractions existing between the two species of trematodes, which gave positive reaction against patient's sera from both S.j. and P.s., while PAA-U caused the reaction only with sera from patients with acute schistosomiasis. PAA-U might be useful to avoid cross reaction in the majority of schistosomiasis patients in the fields.

[Serological cross reaction between schistosomiasis japonica and pagumogonimiasis skrjabini].

The sera from 25 patients with acute, 36 patients with chronic schistosomiasis japonica and 68 patients with pagumogonimiasis skrjabini were tested against SEA, schistosome egg, Paragonimus adult antigen (PAA) and Paragonimus metacercaria using different tests including biotin-avidin system (BAS), ELISA, circumoval precipitate reaction (COPT) and metacercaria membrane reaction (MCMR). Results showed: 1. The specific reactions using PAS and ELISA were (1) both 100% in acute schistosomiasis patients (ASP), (2) 100% and 97.2% respectively in chronic schistosomiasis patients (CSP) and (3) both were 98.5% in paragonimiasis patients (PP). 2. The cross reactions using BAS, ELISA and MCMR were (1) 76%, 72% and 20% respectively in ASP, (2) 27.8%, 22.2% and 19.4% respectively in CSP. 3. The cross reactions using BAS, ELISA and COPT were 26.5%, 30.9% and 8.8% respectively in PP. 4. The frequency of cross reaction was related to the sensitivity of the test used. 5. The frequency of cross reaction in ASP was remarkably lower with MCMR than with BAS or ELISA. 6. The frequency of cross reaction in CSP was related to the intensity of infection. 7. We suggest that more than one test should be carried out in patients who showed cross reaction to a single test, then the frequency of cross reaction would decline.