Impact of chronic outward force on arterial responses of proximal and distal of long superficial femoral artery stent.

BACKGROUND: Self-expanding nitinol stent (SENS) implantation is commonly oversized in the superficial femoral artery (SFA), and leads to chronic outward force (COF) and in-stent restenosis (ISR). This study aimed to investigate the impact of COF of oversizing SENS on ISR of SFA. METHODS: In patients with implanted SENS in SFA, intimal hyperplasia especially between proximal segment and distal segment was evaluated by quantitative angiography, and the impact of COF on mid-term angiographic outcomes was investigated. In addition, porcine model with implanted SENS was used to evaluate the impact of COF on angiographic and histopathologic outcomes at 1 month. Excised stented arteries were evaluated by histopathologic analysis. RESULTS: We analyzed 65 SENS in 61 patients with follow-up angiography at 6 months to 1 year. The baseline diameter was 6.8 ± 0.71 mm and length were 97.0 ± 33.8 mm for the SENS. The ratio of the diameter of the stent to the reference vessel was 1.3 ± 0.24 at the proximal portion and 1.53 ± 0.27 at the distal portion (P < 0.001). In the long SFA stent, stent-to-vessel ratio was significantly higher in the distal stent than in the proximal stent (1.3 ± 0.2 vs. 1.55 ± 0.25, P = 0.001). ISR incidence was higher at the distal stent (37.3% vs 52.6%, P = 0.029). All 11 pigs survived for 4 weeks after SENS implantation. The vessel diameter was 4.04 ± 0.40 mm (control group) vs 4.45 ± 0.63 mm (oversized group), and the implanted stent diameter was 5.27 ± 0.46 mm vs. 7.18 ± 0.4 mm (P = 0.001). The stent-to-vessel diameter ratio was 1.31 ± 0.12 versus 1.63 ± 0.20 (P < 0.001). After 4 weeks, restenosis % was 29.5 ± 12.9% versus 46.8 ± 21.5% (P = 0.016). The neointimal area was 5.37 ± 1.15 mm2 vs. 8.53 ± 5.18 mm2 (P = 0.05). The restenosis % was 39.34 ± 8.53% versus 63.97 ± 17.1% (P = 0.001). CONCLUSIONS: COF is an important cause of restenosis in the distal portion of the SFA stent. Optimal sizing of the SFA stent is important to reduce the incidence of restenosis. Therefore, COF was an important factor of restenosis following distal SFA stenting.

Morphological and Molecular Characterization of Paragonimus Species Isolated from Freshwater Crabs in Southern Yunnan, China.

Paragonimus species are highly prevalent in various regions of China. The study's objective is to isolate and identify Paragonimus from natural habitats and compare the phylogenetic diversity of Paragonimus in southern Yunnan province, China. Metacercariae of Paragonimus was isolated from crabs, and morphologic identification was performed by microscopy. Metacercariae were injected into experimental Paragonimus free Sprague Dawley rats. After 114 days, adult worms and eggs were isolated from multiple organs. Morphologic identification confirmed the initial identification. DNA was extracted from 5 adult worms, and molecular characterization was performed by amplification and sequencing of CO1 and ITS2 regions, followed by phylogenetic analysis. Out of 447 crabs captured, 186 crabs were found to be infected. A total of 4 species of Paragonimus was observed from naturally infected crabs. Paragonimus microrchis (2), Paragonimus heterotremus (1), Paragonimus proliferus (1), and Paragonimus skrjabini (1) were isolated and identified. A total of 32 sequences were downloaded from the National Center for Biotechnology Information, and 5 sequences generated in the study were used for phylogenetic analysis. In the phylogenetic tree of the CO1 gene, Paragonimus proliferus, Paragonimus heterotremus, and Paragonimus skrjabini were clustered with the same species, and the confidence values of their branches were >95%. A congruent phylogenetic relationship was observed with the ITS2 phylogenetic tree. In the phylogenetic tree constructed with the combined dataset of CO1 and ITS2 datasets, Paragonimus proliferus, Paragonimus heterotremus, and Paragonimus skrjabini clustered with the same species, and their branch confidence values were >94%. Paragonimus microrchis clustered with Paragonimus bangkokensis in both datasets. Phylogenetic analysis revealed robustness of the double loci method as against the single-locus method with either CO1 or ITS2 alone. Paragonimus species isolated from the southern Yunnan province, China, was phylogenetically diverse, and the analysis revealed the clustering of multiple species of Paragonimus isolated from different geographic locations.

Construction and characterization of HIV type 1 CRF07_BC infectious molecular clone from men who have sex with men.

This study aimed to investigate the biological characterization of HIV type 1 (HIV-1) CRF07_BC infection among men who have sex with men (MSM). From November 2011 to November 2013, a total of 66 blood samples were collected from MSM with acute HIV-1 infection with CRF07_BC subgroup strains. Deletion in the gag p6 region was detected by sequence alignment and comparative analysis. Peripheral blood mononuclear cells (PBMCs) of HNXX1301-1307 samples were separated by density gradient centrifugation. Nested polymerase chain reaction (nPCR) was used to amplify the viral DNA. The near full-length HIV-1 DNA products were ligated to the long terminal repeat (LTR) vector plasmid (07BCLTR) to construct a full-length HIV clone. The molecular clone was transfected into HEK-293T cells, TZM-b1 cells and patients' PBMCs. The pregenome of an infectious molecular clone of HIV-1 (pNL4-3) was amplified, and a subclone with CRF07_BC was developed to construct the full-length chimeric molecular clone pNL4-3/07BCLTR. Detection of p24 antigen and luciferase activity was used to measure the in vitro infectivity of pNL4-3/07BCLTR. Among the 66 MSM patients infected with CRF07_BC strains, deletion mutations of the Gag P6 proteins were found in 7 of 18CRF07_BC strains; deletion mutations of 2-13 amino acids in different regions were discovered in 6 strains; and the remaining 42 strains did not show deletions. Seven strains with amino acids deficiency in the P6 protein accounted for 27% of all strains and 75% of all deletion genotype strains. A total of 186 full-length molecular clones of CRF07_BC were constructed. There were 5, 9, 10 and 11 clones of HNXX1302, HNXX1304, HNXX1305 and HNXX1306 that resulted in p24-positive supernatant when transfected into HEK-293T cells. Full-length clones of HNXX1302, HNXX1304, HNXX1305 and HNXX1306 showed slight infection in the transfected TZM-b1 cells, as judged by the fluorescence values of TZM-b1 cells 48h post-transfection. However, we were unable to transfect the patients' PMBCs with the above four clones. The phylogenetic tree of the C2V3 segment of the Env gene showed that a significant gene cluster was formed by all of the chimeric full-length HNXX1306 clones, and the bootstrap value for this cluster was 97.5%. Patients' PBMCs could be infected by 1306N6, 1306N13 and 1306N22 chimeric full-length clones. The CRF07_BC subtype (6889-7407 nucleotide residues of HXB2) is one of the most prevalent epidemic HIV-1 virus strains among the MSM population. The full-length chimeric molecular clone pNL4-3/07BCLTR may significantly improve the in vitro infectivity of the CRF07_BC strain.