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One of the requirements for increasing the economic profitability on the large-scale production of second-generation ethanol and other bio-chemicals using lignocellulose biomass as raw materials is efficient hexose and pentose utilization. Saccharomyces cerevisiae, the traditional ethanol producer, is an attractive chassis cell due to its robustness towards harsh environmental conditions and inherent advantages. But S. cerevisiae cannot utilize pentose. The precision construction of suitable strains for second-generation bio-ethanol production has been taken for more than three decades based on the principle of metabolic engineering and synthetic biology. The resulting strains have improved significantly co-fermentation of glucose and xylose. Recently, much attentions have been focused on sugar transport, which is one of the limiting but formerly ignored step for ethanol production from both glucose and xylose, to get the desired state that different sugars could efficiently delivered by their individual specific transporters. In this paper, the progress on sugar transporters of S. cerevisiae was reviewed, and the research status of xylose and/or L-arabinose metabolic engineering in S. cerevisiae were also presented.
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OBJECTIVE: To observe the effects of maternal low-level decabromodiphenyl( BDE209) exposure on nervous system and secretion of thyroid hormones in offspring mice. METHODS: Sixty-four specific pathogen free female,aged 4 weeks Kunming mice were used. These mice were randomly divided into control group and low,medium and high exposure groups after successful mating was confirmed. The rats of control group were fed with 0. 01 L/kg body mass of peanut oil.The maternal mice in the experimental groups were given BDE209 at doses of 50,100 and 300 μg/kg body mass by oral gavage once per day. Continuous exposure was given until 21 days after birth of offspring,the exposure model from gestation to lactation was established. At the end of the exposure,10 mice of each group including half female and half male were randomly selected and the body mass and growth development status were observed. Morris water maze was used to examine the learning and memory ability in offspring mice. The serum levels of total triiodothyronine( TT3),free triiodothyronine( FT3), total tetraiodothyronine( TT4) and free tetraiodothyronine( FT4) were measured by chemiluminescence immunoassay. The levels of glutathione transferase( GST), superoxide dismutase( SOD) and malondialdehyde( MDA) level in hippocampus were measured by colorimetry. RESULTS: The escape latency of the medium exposure group was longer than that of the control group( P < 0. 05). The escape latency of high exposure group was longer than that of control group,low exposure group and medium exposure group( P < 0. 05). The time of quadrant movement and number of crossing the platform in offspring rats in high exposure group were less than that of the control group and the low and medium exposure groups( P < 0. 05). The serum levels of TT3,FT3,TT4 and FT4 increased,the activities of GST and SOD in hippocampus tissue decreased,the MDA level increased with the increasing exposure dose( P < 0. 05).CONCLUSION: Maternal low-level BDE209 exposure can result in decrease the learning and memory ability of offspring mice. It also can increase the serum thyroid hormone level and induce oxidative stress injury in hippocampus in a dose dependent manner in offspring mice.
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Objective To investigate the effect of low dose of BDE209 on thyroid hormone and thyroid hormone metabolism enzyme-iodothyroninedeiodinases Ⅱ(D2) in off spring mice after pregnancy exposure .Methods Total 64 adult SPF female Kun-ming mice were randomly divided into 4 groups ,which treated with oral gavage of 0 ,50 ,100 ,300 μg · kg -1 · d-1 dose of BDE209 after successful pregnancy ,the exposure continue to 21 days after delivery .10 mice was randomly selected in each offspring group and get the peripheral blood and brain sample ,the serum thyroid hormones level ,oxidative damage and the expression of D2 mRNA in brain were detected .Results Compared with the control group(0μg · kg -1 · d-1 dose of BDE209) ,the TT4 ,TT3 ,FT4 and FT3 levels of offspring mice increased significantly in every exposure group (P< 0 .05);antioxidant enzyme glutathione-S transferees (GST) ,superoxide dismutase (SOD) activity decreased with the BDE209 dose increase (P<0 .05) ,and malondialdehyde (MDA) level increased (P<0 .05);the D2 mRNA relative expression of brain in middle(100μg · kg -1 · d-1 dose of BDE209) and high(300μg · kg -1 · d-1 dose of BDE209) dose group decreased when compared with control group (P< 0 .05) .Conclusion Low level of BDE209 exposure in pregnancy resulted in the increasing of thyroid hormone levels in offspring mice ,which may cause oxidative damage and decrease expression of D2 mRNA in the brain .
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Objective To explore the correlation between HIF-1α expression and RANKL/OPG pathway activation of fibroblast-like synoviocytes(FLSs)induced by Ti particles in aseptic loosening interfacial membrane. Method FLSs were extracted from the synovial tissue collected in surgeries and then co-cultured with Ti particles. QRT-PCR and Western blotting were conducted to measure the mRNA and protein expression of RANKL ,OPG and HIF-1αin FLSs at different concentration and time. Results Genes and protein expression levels of RANKL/OPG and HIF-1α were up-regulated with the increase of concentration of Ti particles. Expression of HIF-1α gene and protein increased time-dependently;the mRNA and protein expression of RANKL/OPG increased firstly and then declined alongside the increase of HIF-1αexpression. Conclusions Ti particles induce the up-regulation of HIF-1α expression and activate RANKL/OPG pathway. Up-regulation of HIF-1α may suppress the activation of RANKL/OPG pathway in FLSs of the interfacial membrane induced by Ti particles.
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BACKGROUND:There are numerous laboratory reports concerning β-tricalcium phosphate (β-TCP) bioceramics;however, its application in the treatment of osteonecrosis of the femoral head (ONFH) is rarely reported. OBJECTIVE:To analyze the short-term efficacy of core decompression combined with β-TCP bioceramics in the treatment of ARCO Ⅰ/Ⅱ/ⅢA non-traumatic ONFH. METHODS:Twelve patients (16 hips) suffered from ARCO Ⅰ/Ⅱ/ⅢA non-traumatic ONFH were treated by core decompression combined with β-TCP implantation. The Harris hip scores (HHS) and radiological observation were performed before and after treatment. The HHS at the last follow-up or the HHS prior to the radiographs showing deterioration or severe complication occurrence was recorded. RESULTS AND CONCLUSION:Al patients were followed up for 19 months averagely (11-30 months) and no fracture, infection and other complications occurred. The HHS significantly increased from (73.61±3.70) to (84.88±7.11) points after treatment (P<0.001). The postoperative outcome was excellent in five cases with five hips, good in five cases with nine hips, mild in one case with one hip, poor in one case with one hip, and the excel ent and good rate was 87.5%(14/16). The radiographs of only one case of ARCO ⅡC and one case of ARCO ⅢA showed deterioration, and the latter was given the total hip arthroplasty. These results indicate that the core decompression combined with β-TCP implantation achieve short-term efficacy for ARCO Ⅰ/Ⅱ/ⅢA non-traumatic ONFH.
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Objective To evaluate the association between SNP 399 in X‐ray cross‐complementing group 1 (XRCC1) and na‐sopharyngeal carcinoma susceptibility .Methods The case‐control studies on the association between SNP 399 in XRCC1 (X‐ray cross‐complementing group 1) and nasopharyngeal carcinoma susceptibility were collected by CBM disc and Pubmed .Various re‐search and statistical analysis were used by Stata12 .0 and Review Manager 5 .0 software .Taking the fixed effects model or random effects model to merge OR values and corresponding 95% confidence intervals to assess Arg399Gln polymorphism and genetic sus‐ceptibility to nasopharyngeal .Results Compared 399Gln with 399Arg allele ,combined OR and 95% CI were 1 .14 (1 .04 - 1 .26) respectively ,and the results of heterogeneity test was I2 = 32% ,PHet = 0 .18 .Under the recessive and co‐dominant models ,combined OR and 95% CI were 1 .30(1 .04 - 1 .63) and 1 .37(1 .09 - 1 .72) respectively ,and with no significant heterogeneity was observed (I2 = 0 ,PHet = 1 .00) and (I2 = 0 ,PHet = 0 .96) .Conclusion XRCC1 gene Arg399Gln polymorphism is closely related to the genetic susceptibility of NPC ,399Gln allele may be a risk of genetic factors in NPC incidence in asians .