Temporal and Spatial Variation of Toxic Metal Concentrations in Cultivated Soil in Jiaxing, Zhejiang Province, China: Characteristics and Mechanisms.

The toxic metal (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) pollution in 250 agricultural soil samples representing the urban area of Jiaxing was studied to investigate the temporal and spatial variations. Compared to the early 1990s, the pollution level has increased. Industry and urbanization were the main factors causing toxic metal pollution on temporal variation, especially the use of feed containing toxic metals. The soil types and crop cultivation methods are the main factors causing toxic metal pollution on spatial variation. Although the single-factor pollution indices of all the toxic metals were within the safe limits, as per the National Soil Environmental Quality Standard (risk screening value), if the background values of soil elements in Jiaxing City are used as the standard, the pollution index of all the elements surveyed exceeds 1.0, reaching a level of mild pollution. The soil samples investigated were heavily contaminated with toxic metal compounds, and their levels increased over time. This situation poses potential ecological and health risks.

Assessing Pb-Cr Pollution Thresholds for Ecological Risk and Potential Health Risk in Selected Several Kinds of Rice.

The expected typical gley moist paddy soil was collected in Zhejiang Province, China, and conventional (XS 134 and JH 218) and varieties of hybrid (YY 538 and CY 84) rices were used for a pot experiment. The effects of exogenous heavy metals lead (Pb) and chromium (Cr) on rice growth and the accumulation of heavy metals in the grains were studied. The results show that heavy metal concentrations in soil and rice grains have significant correlations, and Pb and Cr significantly (p < 0.05) inhibited the rice growth (plant height and panicle weight). The potential ecological hazard index (RI) of heavy metals in the soil was 4.88−6.76, which belongs to the grade of "slight ecological hazard", and Pb provides a larger potential ecological hazard than Cr in the studied region. The thresholds for potential health risks and ecological risks for Pb and Cr were lower than the "Control Standards for Soil Pollution Risk of Agricultural Land (Trial)" (GB15618-2018, China). This work provides the basis for soil pollution control for Pb and Cr and the selection of rice cultivars from Pb and Cr accumulated soils.

Association of IL-10 and IL-10RA single nucleotide polymorphisms with the responsiveness to HBV vaccination in Chinese infants of HBsAg(+)/HBeAg(-) mothers: a nested case-control study.

OBJECTIVES: To investigate the association of interleukin (IL)-10 and IL-10 receptor A (IL-10RA) single nucleotide polymorphisms with the responsiveness to hepatitis B virus (HBV) vaccination in newborns whose mothers were hepatitis B surface antigen (HBsAg)(+)/hepatitis B e antigen (HBeAg)(-). DESIGN: Nested case-control study. SETTING: Changchun, China. PARTICIPANTS: 713 infants from a Han Chinese population whose mothers were HBsAg(+)/HBeAg(-) and participated in the prevention of mother-to-child transmission of HBV at the First Hospital of Jilin University from July 2012 to July 2015 were included. Infants were excluded for HBsAg-positive; unstandardised vaccination process; inadequate blood samples; not Han Chinese and failed genotyping. RESULTS: Infants with artificial feeding pattern were correlated with low responsiveness to HBV vaccination (p=0.009). The GG genotype of IL-10 rs3021094 was correlated with a higher risk of low responsiveness to HBV vaccination (OR 2.80, 95% CI 1.35 to 5.83). No haplotype was found to be correlated with responsiveness to HBV vaccination. No gene-gene interaction was found between IL-10 and IL-10RA. CONCLUSIONS: Our study found that IL-10 gene variants were significantly associated with the immune response to the HBV vaccine. Identifying these high-risk infants who born to HBsAg(+)/HBeAg(-) mothers and low responses to hepatitis B vaccination will provide evidence for individualised prevention strategies.

20 µg hepatitis B vaccination reduced the risk of low responsiveness in infants with HLA-II risk genotype of HBsAg positive mothers.

Infants born to HBV carrier mothers are persistently at a higher risk for HBV infection. We investigated the association between HLA SNPs and low responsiveness to HBV vaccination, and the differences of immune response in carriers of risk genotypes who received different doses of the vaccination. 1040 infants from the prevention of mother-to-infant transmission of HBV cohort were included. Infants born to HBsAg (+) and HBeAg (-)/HBeAg (+) mothers received 10 µg/20 µg hepatitis B vaccine, respectively. Rs2857127, rs3135338, rs477515, rs9277554 and rs9286790 in HLA regions were well genotyped. A lower rate of low-responsiveness was observed in the 20 µg group. Rs3135338 GG and rs9277554 TT genotype showed stronger associations with low responsiveness (P < 0.05). The combination of 10 µg vaccine with the risk genotypes was independently associated with remarkably increased risk of low-responsiveness to hepatitis B vaccines (P < 0.05). HLA SNPs were associated with low-responsiveness to hepatitis B vaccine. For infants with risk genotypes, a 20 µg dose vaccine reduced the risk of low responsiveness.

Rolling-circle replication initiation protein of haloarchaeal sphaerolipovirus SNJ1 is homologous to bacterial transposases of the IS91 family insertion sequences.

For most archaeal viruses, the mechanisms of genome replication are poorly understood, while the nature and provenance of their replication proteins are usually unknown. Here we show that replication of the circular double-stranded DNA genome of the halophilic Natrinema virus SNJ1, a member of the family Sphaerolipoviridae, is associated with the accumulation of single-stranded replicative intermediates, which is typical of rolling-circle replication. The homologues of RepA, the only enzyme that is indispensable for SNJ1 genome replication, are widespread in archaea and are most closely related to bacterial transposases of the IS91 and ISCR family insertion sequences, as opposed to other viral rolling-circle replication initiation proteins. Our results provide insights into the replication mechanism of archaeal viruses and emphasize the evolutionary connection between viruses and other types of mobile genetic elements.

Construction of Expression Shuttle Vectors for the Haloarchaeon Natrinema sp. J7 Based on Its Chromosomal Origins of Replication.

Haloarchaeon Natrinema sp. J7, the first reported archaeon harboring both plasmid and chromosome-based temperate viruses, is a useful model for investigating archaeal virus-host and virus-virus interactions. However, the lack of genetic tools has limited such studies. On the basis of the automatically replicating sequences of the J7 chromosome and the pyrF marker, we constructed seven vectors, six of which were confirmed to possess replication ability in a pyrF-deletion derivative of J7 (J7-F). Among these vectors, pFJ1, pFJ4, and pFJ6 could be transformed into the host strain with relatively high efficiency (approximately 103 colony-forming units/µg DNA) and were present at about one copy per chromosome. These three vectors could be stably maintained in J7-F without selection and were used for heterologous protein expression. Only pFJ6 was found to be present in the transformed cells in an exclusively episomal, nonintegrated state (one copy per chromosome). In contrast, some pFJ1 and pFJ4 DNA was probably integrated into the J7-F chromosome. In addition, pFJ6 was found to be compatible with pYCJ in J7 cells, suggesting that these two vectors could be used for further studies of virus-virus and virus-host interactions.