In recent years, researches on cells, animals, and human beings have found that the carcinogenic mechanism of environmental carcinogen benzo (a) pyrene〔B(a)P〕can reduce methyla?tion of the whole genes, increase the tumor suppressor gene methylation and reduce the gene methyla?tion of proto-oncogene, in addition to the genetic toxicity. It can also cause changes in small RNA expression, the increase of long-chain non-coded RNA expression and imbalance in histone phosphor?ylation expressions. These changes can cause abnormalities in gene expression and chromosome structure and instability, directly leading to cancer. These changes can also cause the corresponding changes of genetic toxicity, such as gene mutation, abnormal genetic damage repair, increas of cell apoptosis and cell cycle arrest. All these are considered to be potential epigenetic mechanisms of B(a)P. Existing researches have provided the scientific basis for the mechanism of and prevention counter?measures for environment-related diseases and vocational diseases caused by B(a)P.

Virophages have crucial roles in ecosystems and are the transport vectors of genetic materials. To shed light on regulation and control mechanisms in virophage--host systems as well as evolution between virophages and their hosts, the promoter motifs of virophages were predicted on the upstream regions of start codons using an analytical tool for prediction of promoter motifs: Multiple EM for Motif Elicitation. Seventeen potential promoter motifs were identified based on the E-value, location, number and length of promoters in genomes. Sputnik and zamilon motif 2 with AT-rich regions were distributed widely on genomes, suggesting that these motifs may be associated with regulation of the expression of various genes. Motifs containing the TCTA box were predicted to be late promoter motif in mavirus; motifs containing the ATCT box were the potential late promoter motif in the Ace Lake mavirus . AT-rich regions were identified on motif 2 in the Organic Lake virophage, motif 3 in Yellowstone Lake virophage (YSLV)1 and 2, motif 1 in YSLV3, and motif 1 and 2 in YSLV4, respectively. AT-rich regions were distributed widely on the genomes of virophages. All of these motifs may be promoter motifs of virophages. Our results provide insights into further exploration of temporal expression of genes in virophages as well as associations between virophages and giant viruses.
Base Sequence ; Evolution, Molecular ; Genome, Viral ; genetics ; Genomics ; Nucleotide Motifs ; genetics ; Promoter Regions, Genetic ; genetics ; Satellite Viruses ; genetics

Objective To explore the clinical significance of interventional treatment of iliac vein compression syndrome(IVCS). Methods Percutaneous transluminal angioplasty(PTA) was performed in 40 cases. Thirty three cases underwent endovascular stent implantation and 27 cases underwent second stage left saphenous vein ligation and stripping and the valves of left femoral veins narrowing. Thirty one cases were followed up postoperatively and the duration was 6～66 months (mean 28 months). Results The dilation of iliac veins was successful in 36 cases and there were good efficacy in all patients when they discharged from hospital. Followed up during post operation, all the limbs ulcers were cured and varicose veins disappeared. The skin pigmentation disappeared in 17 of 19 cases and markedly relieved in 2 cases. Left lower limb swelling disappeared in 15 of 17 cases and relieved in 2cases. Conclusion There is good efficacy in the interventional treatment of left iliac vein lesions, but second stage procedures should be performed in secondary lesions of saphenous veins and valves of femoral veins.

Objective To evaluate the role of temporary arteriovenous fistula(AVF) in the treatment of acute deep venous thrombosis(DVT) with Amplatz thrombectomy device(ATD). Method Seventy-six cases of acute DVT underwent mechanical thrombolysis with ATD, in which 50 cases received a temporary AVF after interventional therapy. Result One case died of pulmonary embolism. Ipsilateral limbs swelling subsided and pain alleviated in the remaining 72 cases since first post-operative day. Secondary contralateral DVT developed in 2 cases on the 7th post-operative day. The patency of temporary AVF was 86%(43/50). Sixty-eight cases (90.7%) were followed-up for 10~42 months post-operatively with limbs swelling completely subsided in 59 cases and ameliorated in 6 cases. Secondary inferior vena cava thrombosis developed in one case and 2 cases died of unrelated diseases. Conclusion Temporary AVF increases blood flow volume and blood velocity in the thrombectomized vein segment to improve the vein patency, hence is a valuable auxiliary means of ATD.

Objective To explore the appropriate method for mechanical thrombectomy, selection of vena cava filter and its duration in place. Method Fifty-five cases of severe acute deep vein thrombosis of the lower limbs were enrolled. Vena cava filter was first placed, then thrombectomy was performed with Amplatz thrombectomy device (ATD). The iliac vein lesions were dilated by balloon followed by temporary arterivenous fistula construction. Result Procedures were all successful in 52 cases, iliac vein stenosis was found in 47 cases and dilated by balloon. Permanent vena cava filters were placed in 20 cases while temporary in 32 cases. Fifty cases were followed-up for 3～30 monthes. Tumefaction disappeared in 46 cases leaving no after thrombosis syndrome. Conclusion This comprehensive modality is effective, less traumatic and of quick recovery. During the procedure, possible residual thrombi should always be under close attention and stenosis in iliac veins be confirmed by repeated venography. In most cases, placing a temporary vena cava filter was the best choice.

Objective To evaluate the effects of Amplatz thrombectomy device (ATD), thrombolysis (TL), and surgical thrombectomy (TX) on venous wall morphology complicated with acute femoral vein thrombosis in dogs. Methods The femoral venous thrombosis model was induced in 36 adult mongrel dogs. The thrombosed veins were treated with ATD ( n =12), TL ( n =12), and TX ( n =12), respectively. Results Clearance of thrombus was successful in all cases. One week after treatment, the rate of venous patency in ATD, TL, and TX group was 75%, 33%, and 25%, respectively ( P