[Molecular mechanisms of antithrombin deficiency caused by novel double heterozygous mutations].

OBJECTIVE: To explore the molecular mechanisms of antithrombin (AT) deficiency caused by novel double heterozygous mutations. METHODS: Wild-type and mutant AT cDNA expression plasmids (ATwt, AT-c.134G > A, AT-c.342T > G, AT-c.134G > A and AT-c.342T > G) were transfected into HEK293T cells. Western blot was used to detect the AT:Ag in cell lysates. Homology was used to reestablish 3-D spatial structure of AT. Laser confocal assay was utilized to analyze the distribution of AT in endoplasmic reticulum (ER). RESULTS: Compared to the wild-types, the AT expression of HEK293T cells sharply increased when they were transfected by AT-c.342T > G or AT-c.134G > A and c.342T > G. Homology modeling showed that the mutation (AT-c.342T > G) caused a decreased distance between Arg and surrounding bases as Arg's side chain was significantly longer than Ser's. The mutation of 13th base pair decreases the distance between AT and heparin. Laser confocal assay showed that the AT protein concreted in HEK293T cells when they were transfected by mutant plasmids (AT-c.134G > A and c.342T > G) and aggregated in ER. CONCLUSIONS: The main molecular mechanism of AT deficiency in this pedigree is the disturbed AT secretion as a result of the mutation of AT-c.342T > G.

[Subintimal arterial flossing with antegrade-retrograde intervention technique to treat long-segment occlusion of peripheral artery].

OBJECTIVE: To discuss the technique details of subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) to improve technical success in the treatment of chronic total occlusions (CTO) diseases in lower extremity when there is failure to reenter the distal true lumen. METHODS: Between May 2009 and Aug 2010, 15 patients underwent endovascular recanalization with SAFARI technique. There were 8 male and 7 female patients with a mean age of 74.9 years. There were 3 patients with severe claudication (Rutherford category 3) and 12 patients with critical limb ischemia (Rutherford category 4 to 6). The clinical and follow-up data of these patients were analyzed retrospectively. RESULTS: Fourteen patients were treated with SAFARI technique successfully. The technique success rates were 93.3%. The mean ankle brachial index increased from 0.39 to 0.83.Symptoms were relieved in 86.6% patients, Ulcer were healed in 93.3%patients. CONCLUSIONS: SAFARI technique is a safe and effective method in treating CTO diseases, when it is failure to renter the distal true lumen with subintimal angioplasty technique.

Drug packaging and delivery using perfluorocarbon nanoparticles for targeted inhibition of vascular smooth muscle cells.

AIM: To investigate the in vitro release profile of drugs encapsulated within perfluorocarbon (PFC) nanoparticles (NPs) and their ability to inhibit the activity of vascular smooth muscle cells (SMCs). METHODS: Dexamethasone phosphate (DxP) or dexamethasone acetate (DxA) was encapsulated into PFC nanoparticles using a high-pressure homogenous method. The morphology and size of the NPs were examined using scanning electron microscopy (SEM) and a laser particle size analyzer. Drug loading and in vitro release were assessed by high-performance liquid chromatography (HPLC). The impact of NP capsules on SMC proliferation, migration and apoptosis in vitro was assessed using cell counting kit-8, transwell cell migration and flow cytometry assays. RESULTS: The sizes of DxP-NPs and DxA-NPs were 224+/-6 nm and 236+/-9 nm, respectively. The encapsulation efficiency (EE) of DxP-NPs was 66.4%+/-1.0%, with an initial release rate of 77.2%, whereas the EE of DxA-NPs was 95.3%+/-1.3%, with an initial release rate of 23.6%. Both of the NP-coated drugs could be released over 7 d. Human umbilical artery SMCs were harvested and cultured for four to six passages. Compared to free DxP, SMCs treated with tissue factor (TF)-directed DxP-NPs showed significant differences in the inhibition of proliferation, migration and apoptosis (P<0.05). CONCLUSION: The results collectively suggest that PFC nanoparticles will be beneficial for targeted drug delivery because of the sustained drug release and effective inhibition of SMC proliferation and migration.