[Adsorption of Phosphate on Mg/Fe Layered Double Hydroxides (Mg/Fe-LDH) and Use of Mg/Fe-LDH as an Amendment for Controlling Phosphorus Release from Sediments].

We determine the efficiency and mechanism of Mg/Fe layered double hydroxides (Mg/Fe-LDH) addition for the control of phosphorus (P) release from sediments by studying the adsorption behavior and mechanism of phosphate from an aqueous solution on Mg/Fe-LDH. The impact of Mg/Fe-LDH addition on the mobilization of P in sediments as well as the adsorptive removal of phosphate by sediments is investigated, and the stabilization of P bound by Mg/Fe-LDH is also evaluated. Results showed that the kinetics data of phosphate adsorption onto Mg/Fe-LDH fitted better with the Elovich kinetics model than with the pseudo-first-order and pseudo-second-order kinetics models, and that the Freundlich and Dubinin-Radushkevich models were more suitable for describing the adsorption isotherm behavior of phosphate on Mg/Fe-LDH than the Langmuir model. Phosphate adsorption possessed a wide effective pH range of 4-10. Coexisting Ca2+ and Mg2+ enhanced phosphate adsorption onto Mg/Fe-LDH, while coexisting Na+, K+, and Cl- had negligible impacts on the phosphate adsorption. The presence of SO42- and HCO3- in aqueous solution inhibited the adsorption of phosphate on Mg/Fe-LDH. The phosphate adsorption mechanisms were deduced to be anion exchange, electrostatic attraction, ligand exchange and inner-sphere complex formation. The addition of Mg/Fe-LDH into sediments not only greatly reduced the concentration of reactive soluble P (SRP) in the overlying water, but also significantly decreased the level of SRP in the pore water. In addition, Mg/Fe-LDH addition also increased the adsorption capacity for the sediments, and the phosphate adsorption ability for the Mg/Fe-LDH-amended sediments increased with increased amendment dosage. Almost half of the phosphate bound by Mg/Fe-LDH existed in the form of relatively stable P, i.e., metal oxide-bound P (NaOH-rP), which was difficult to release back into the water column under normal pH and anoxic conditions. Nearly half of the phosphate bound by Mg/Fe-LDH existed in the form of easily released P, i.e., NH4Cl extractable P (NH4Cl-P) and redox-sensitive P (BD-P), which had a high risk of re-releasing into the water column. We conclude that it is very necessary for Mg/Fe-LDH to be recycled from the sediments after the application of Mg/Fe-LDH as an amendment to control sedimentary P liberation.

Hepatitis C virus infection of human cytotrophoblasts cultured in vitro.

Hepatitis C virus (HCV) infection in the uterus is a significant path of vertical HCV transmission. Some studies consider vertical HCV transmission in the uterus as the result of maternal blood leakage into infant blood, whereas others theorize that HCV is transmitted by the mother to the infant through cells constituting the placenta barrier. Although trophoblasts play an important role in the placenta barrier, no definitive evidence has been presented to prove that cytotrophoblasts can be infected with HCV. The current study investigated whether or not these can be infected with HCV by conducting an experiment, in which cultured human cytotrophoblasts were infected with HCV in vitro. The results were analyzed using reverse transcription polymerase chain reaction (RT-PCR), ultrastructural characteristic changes under an electron microscope, and immunoelectron microscopy. HCV RNA in the supernatant of the cultured medium of the infected group was intermittently detected during the 16-day incubation period using RT-PCR. Under an electron microscope, the ultrastructures of infected human cytotrophoblasts were markedly different from normal cells, demonstrating lysosomal hyperplasia, rough endoplasmic reticulum, decreased lipid droplets, presence of vacuoles, and the appearance of HCV-like particles. Using immunoelectron microscopy, HCV-like particles conjoined with golden granules were also observed. Based on the data, the current study concludes that HCV infects a human cytotrophoblast cultured in vitro; moreover, its ultrastructure changes dramatically upon infection.

Altered expression profiles of microRNAs in a stable hepatitis B virus-expressing cell line.

BACKGROUND: MicroRNAs (miRNAs) are highly conserved small non-coding RNAs of 18 - 25 nucleotides (nt) that mediate post-transcriptional gene regulation. Hepatitis B virus (HBV) can cause either acute or chronic hepatitis B, and is a high risk factor for liver cirrhosis and hepatocellular carcinoma. Some mammalian viruses have been shown to modulate the expression of host cellular miRNAs. However, interactions between the HBV and the host cellular miRNAs are largely unknown. METHODS: miRNA microarray and Northern blotting analysis were used to compare the expression profile of cellular miRNAs of a stable HBV-expressing cell line HepG2.2.15 and its parent cell line HepG2. mRNA microarray assay and the miRanda program were used to predict the miRNA targets. A flow cytometric assay was further used to investigate the expression of human leukocyte antigen (HLA)-A. RESULTS: Eighteen miRNAs were differentially expressed between the two cell lines. Among them, eleven were up-regulated and seven were down-regulated in HepG2.2.15 cells. Northern blotting analysis confirmed that the expression of miR-181a, miR-181b, miR-200b and miR-146a were up-regulated and the expression of miR-15a was down-regulated, which was in consistent with the results of the microarray analysis. Furthermore, some putative miRNA targets were predicted and verified to be linked with mRNA expression. The 3'-UTR of HLA-A gene had one partially complementary site for miR-181a and miR-181a might down-regulate the expression of HLA-A. CONCLUSION: HBV replication modulates the expression of host cellular miRNAs, which may play a role in the pathogenesis of HBV-related liver diseases.

[Screening and identification of proteins interacting with HCV NS4A via yeast double hybridization in leukocytes and gene cloning of the interacting protein].

OBJECTIVE: To screen proteins interacting with HCV NS4A protein in leukocytes by yeast-double hybridization. METHODS: The bait plasmid pGBKT7-NS4A was transformed into yeast AH109 was transformed, and the expressing of the fusion protein was identified by SDS-page. The transformed yeast was mated with yeast Y187 containing leukocytes cDNA library plasmid in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for selecting two times and screening. After extracting and sequencing of plasmid from blue colonies, analysis was conducted by bioinformatics. And, the gene encoding the interesting protein was cloned, and back-cross was performed. RESULTS: Forty-five colonies were sequenced, among them, 29 colonies were human calcium modulating cyclophilin ligand (CAML). The gene encoding CAML was cloned, and the interaction between NS4A and CAML was ensured. CONCLUSION: Seven kinds of proteins interacting with NS4A in leukocytes were successfully screened and the results brought some new clues for studying the pathogenesis of HCV.

[IFN or oxymatrine in combination with lamivudine in patients with lamivudine-resistant chronic hepatitis B].

OBJECTIVE: To observe the therapeutic efficacy of IFN or oxymatrine in combination with lamivudine in patients with lamivudine-resistant chronic hepatitis B. METHODS: Forty patients ongoing treatment with lamivudine were randomized to three groups: group A, 14 patients with addition of IFN alpha-2b 3MU to ongoing lamivudine, daily, one month, followed by the same dose given every other day, five months; group B, 15 patients with addition of injectable oxymatrine 60 mg daily, three months, followed by oral oxymatrine every day, three months, and group C, 11 patients ongoing treatment with lamivudine alone. The HBV DNA level in serum, HBeAg seroconversion, and ALT level were detected at the end of the treatment. RESULTS: After 6 months of treatment, HBV DNA became negative in 35.73% patients treated with combination with IFN, and in 13.3% patients treated with combination with oxymatrine. ALT level was normal in 85.71% or 86.66% of patients, respectively. In none of the patients under ongoing treatment with lamivudine alone HBV DNA or HBeAg became negative, and ALT level was normal in 36.36% of patients. CONCLUSION: These data indicated that IFN or oxymatrine in combination with ongoing lamivudine therapy provided effective antiviral therapy in patients with lamivudine-resistant HBV. The addition of IFN or oxymatrine to ongoing lamivudine therapy in lamivudine-resistant patients led to significant inhibition of viral replication and improvement in liver function after 6 months of therapy.

[Analysis on factors related to X-ray outcomes in 93 SARS patients].

OBJECTIVE: To study the related factors of the X-ray outcomes in recovered SARS patients. METHODS: The X-ray results of 93 patients with SARS were studied retrospectively. The possible related factors analyzed were age, sex, body temperature at onset, range of the lesion, glucocorticoid administration time. The data were analyzed by chi square test. RESULTS: Among all the patients with abnormal X-ray result, 19 were male (54.29%), 16 (45.71%) were female, P > 0.01; 7 (58.33%) were above the age of 45; 28 (34.57%) were below the age of 45, P > 0.01; hyperpyrexia (>/= 39), 26 (50.00%), below 39, 9 (21.95%); multiple-lesion, 22 (52.38%), mono-lesion, 13 (25.49%), P < 0.01; glucocorticoid administration time within 5 days, 22 (38.60%) after 5 days, 12 (33.33%), P > 0.01; within 7 days, 21 (30.00%), after 7 days, 14 (60.87%), P < 0.01. CONCLUSION: The X-ray results of SARS were closely related to the severity of the disease (hyperpyrexia and bilateral lung field lesion). There was no significant correlation between X-ray result and the age or sex of the patients. Early use of glucocorticoid (within 5 days after onset), had no remarkable influence on the X-ray result. It was noted, however, the incidence of residual lesion in lung obviously increased if glucocorticoid was administered after 7 days of onset.

Methodologic research on TIMP-1, TIMP-2 detection as a new diagnostic index for hepatic fibrosis and its significance.

AIM: To set up a new method to detect tissue inhibitors of metalloproteinase-1 and -2(TIMP-1 and TIMP-2) in sera of patients with hepatic cirrhosis, and to investigate the expression and location of TIMP-1 and TIMP-2 in liver tissue of patients with hepatic cirrhosis, and the correlation between TIMPs in liver and those in sera so as to discuss whether TIMPs can be used as a diagnosis index of hepatic fibrosis. METHODS: The monoclonal antibodies (McAbs) of TIMP-1 and TIMP-2 were used to sensitize erythrocytes, and solid-phase absorption to sensitized erythrocytes (SPASE) was used to detect TIMP-1 and TIMP-2 in the sera of patients with hepatic cirrhosis. Meanwhile, with the method of in situ hybridization and immunohistochemistry, we studied the mRNA expression and antigen location of TIMP-1 and TIMP-2 in the livers of 40 hepatic cirrhosis patients with pathologic diagnosis. RESULTS: With SPASE, they were 16.4% higher in the acute hepatitis group, 33.3% higher in the chronic hepatitis group, and the positive rates were 73.6% and 61.2% respectively in sera of hepatic cirrhosis patients, which were remarkably higher than those in chronic hepatitis and acute hepatitis group (P<0.001). In 40 samples of hepatic cirrhosis tissues, all of them showed positive expression of TIMP-1 and TIMP-2 mRNA detected with immunohistochemistry or in situ hybridization (positive rate was 100%). Expression of TIMPs in different degrees could be found in liver tissue with cirrhosis. TIMPs were located in cytoplasm of liver cells of patients with hepatic cirrhosis. There was a significant correlation between serum TIMPs level and liver TIMPs level. CONCLUSION: SPASE is a useful method to detect the TIMP-1 and TIMP-2 in sera of patients with hepatic cirrhosis, and TIMP-1 and TIMP-2 can be considered as a useful diagnostic index of hepatic fibrosis, especially TIMP-1.