ABSTRACT
A survey involving 6103 participants from five Chinese provinces was conducted to evaluate the threshold value of urinary cadmium (UCd) for renal dysfunction as benchmark dose low (BMDL). The urinary N-acetyl-β-D-glucosaminidase (UNAG) was chosen as an effect biomarker. The UCd BMDLs for UNAG ranged from 2.18 μg/g creatinine (cr) to 4.26 μg/g cr in the populations of different provinces. The selection of the sample population and area affect the evaluation of the BMDL. The reference level of UCd for renal effects was further evaluated based on the data of all 6103 subjects. With benchmark responses (BMR) of 10%/5%, the overall UCd BMDLs for males in the total population were 3.73/2.08 μg/g cr. The BMD was slightly lower in females, thereby indicating that females may be relatively more sensitive to Cd exposure than are males.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cadmium , Toxicity , Urine , China , Epidemiology , Creatinine , Urine , Dose-Response Relationship, Drug , Environmental Pollutants , Toxicity , Urine , Kidney Diseases , Population SurveillanceABSTRACT
<p><b>OBJECTIVE</b>Respiratory syncytial virus (RSV) is the most common cause of lower respiratory infection in infants. It is very important to quantitative assay of RSV titer in the study on RSV pathogenesis, candidate vaccine and antiviral treatment. Therefore, we develop Real-time Quantitative PCR (Q-PCR) assay and enzyme immunospots (EIS) for titrating RSV and compare them with traditional 50% tissue culture infectious doses (TCID50).</p><p><b>METHODS</b>Q-PCR, based upon the RSV-L genes, and EIS were utilized to titrate samples from RSV culture supernatants and RSV infected mouse lungs. Then, the results were compared with TCID50.</p><p><b>RESULTS</b>For the samples from RSV culture supernatants, the ratio of Q-PCR and EIS (plaque forming unit, pfu) was 10:1 and the ratio of EIS and TCID50 was 10:1 when TCID50 was converted as pfu. For the samples from RSV infected mouse lungs, the ratio of Q-PCR and EIS was 1000:1 and the ratio of EIS and TCID50 was 5:1.</p><p><b>CONCLUSION</b>We have successfully established Q-PCR and EIS to titrate RSV and compared them with TCID50. We concluded EIS is a cost-effective method to titrate RSV.</p>
Subject(s)
Humans , Cell Line , Immunoenzyme Techniques , Polymerase Chain Reaction , Respiratory Syncytial Viruses , Genetics , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>To study the expression and purification of a secreted form of fusion glycoprotein (sF) of human respiratory syncytial virus (RSV) encoded by recombinant baculovirus.</p><p><b>METHODS</b>According the ORF of F protein, a pair of specific primers was designed and PCR technique was exploited to amplify the gene of sF in which the gene sequence of the transmembrane and cytoplasmic tail domains were replaced by a C-terminal six-histidine tag. Then, a recombinant baculovirus encoding sF-His was constructed, and transfected into sf9 insect cells by Lipofectamine cellfectine reagent. Finally, the expressed sF was purified by Ni2+ -affinity chromatograph.</p><p><b>RESULTS</b>The gene encoding sF-His was obtained. The resulting construct of recombinant baculovirus is capable of expressing sF protein. The concentration of Ni2+ -affinity chromatograph purified sF is 1.084 mg/ml with the purity of no less than 90%.</p><p><b>CONCLUSION</b>Baculovirus expression system is a good method for large scale of preparation of sF. The purified F paves the way for the development of potential RSV vaccine and diagnostic kit, etc.</p>
Subject(s)
Animals , Humans , Baculoviridae , Genetics , Metabolism , Cell Line , Gene Expression , Genetic Vectors , Genetics , Metabolism , Protein Transport , Recombinant Fusion Proteins , Genetics , Metabolism , Respiratory Syncytial Virus, Human , Genetics , Metabolism , Spodoptera , Viral Fusion Proteins , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>A strain of replication deficient recombinant adenvirus encoding fusion glycoprotein (F) of subgroup A human respiratory syncytial virus (RSV) was constructed and the expression of F was identified.</p><p><b>METHODS</b>The F gene was obtained from pGEM3zf-F with Xho I and Hind III, cloned into adenoviruse shuttle vector pShuttle-CMV,and then the resulting pShuttle-CMV/F was transformed into E. coli BJ5183/p with pAdeasy-1 to produce pre-adenoviral plasmid encoding F by homologous recombination. This resultant plasmid was linearized by digestion with Pac I and transfected into 293 packaging cells to generate FGAd-F. Finally, the expression of F protein was identified by Western Blot analysis.</p><p><b>RESULTS</b>FGAd/F was successfully constructed, and the expression of RSV F protein was identified by Western Blot.</p><p><b>CONCLUSION</b>We have obtained a strain of replication-defective adenovirus FGAd/F encoding RSV F protein, which can be used further to investigate its protective efficacy against RSV infection in vivo.</p>