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D Benjamin Christie

Publications and source records attributed to D Benjamin Christie.

7 recordsLinked to original sources
PubMed2006

Accelerated migration and proliferation of smooth muscle cells cultured from neointima induced by a vena cava filter.

Formation of a neointima is associated with grafted artery or vein, angioplasty, and stent and inferior vena cava filter (IVCF) implantation. Contributing to the neointima is a population of vascular smooth muscle cells (SMC) that migrates from media and subsequently proliferates within intima. The purpose of this present study was to culture SMC from normal vessel wall and from neointima and to compare migration and growth of these cells. Neointima was stimulated in the vena cava of pigs by placement of an IVCF for 30 days. Tissue was taken from the thickened wall between the struts and from a normal segment of the IVCF. After removal of the endothelium and adventitia, explants were placed in culture dishes and were observed for the migration of cells. Immunoassay for smooth muscle alpha-actin was used to identify cell origin. Proliferation was determined by cell counting. The cell cycle regulator cyclin D1 was detected by Western blot analysis. SMC phenotype was confirmed by positive immunostaining for smooth muscle alpha-actin. Cells migrated from the neointimal explants (NI-SMC) more rapidly than cells from explants of normal media (NM-SMC). Proliferation of NI-SMC was also more rapid than NM-SMC with or without exogenous mitogens. NI-SMC expressed more cyclin D1 than NM-SMC. Injury to the vena cava triggered neointima formation characterized by the expansion of a population of SMC with increased migration and replication compared with SMC from normal regions of the vessel.

Animals↗
PubMed2005

The results of superficial femoral, popliteal, and tibial artery stenting for peripheral vascular occlusive disease.

The purpose of this study was to evaluate the patentcy rates and physiological effectiveness of angioplasty and stenting as a primary therapy for superficial femoral (SFA), popliteal (POP), and tibial (TIB) arterial occlusive disease. Seventy-eight patients had stents placed in the infra-inguinal vessels between January 1, 2001, and July 31, 2004. We collected data on patient demographics, symptoms, as well as pre- and postprocedure ankle-brachial index (ABI) and angiographic findings. Patency rates at 6 months, 12 months, and 24 months were analyzed by life table methods. Thirty-one men and 47 women had a mean age of 68 years (range 36-94 years). Risk factors included diabetes in 50 per cent, hypertension in 79 per cent, smoking in 41 per cent, and end-stage renal disease in 10 per cent. The indications for intervention were claudication in 52 per cent and limb salvage in 48 per cent of patients. Stents were placed in the SFA in 54 patients (69%), in the POP in 15 patients (18%), and in the TIB artery in 6 patients (8%). Average follow-up was 11.2 months. The mean postprocedural increase in ABI was 0.29. The 6-month, 1-year, and 2-year primary patency rates were 83 per cent, 58 per cent, and 47 per cent, respectively. Limb salvage was achieved in 66 per cent of patients treated for limb-threatening ischemia. There was one major and three minor complications. Stenting of the infra-inguinal vessels has a low morbidity, high success rate, and acceptable patency and limb-salvage rates.

Adult↗
PubMed2004

l-Galactose replaces l-fucose in the pectic polysaccharide rhamnogalacturonan II synthesized by the l-fucose-deficient mur1 Arabidopsis mutant.

Arabidopsis thaliana mur1 is a dwarf mutant with altered cell-wall properties, in which l-fucose is partially replaced by l-galactose in the xyloglucan and glycoproteins. We found that the mur1 mutation also affects the primary structure of the pectic polysaccharide rhamnogalacturonan II (RG-II). In mur1 RG-II a non-reducing terminal 2- O-methyl l-galactosyl residue and a 3,4-linked l-galactosyl residue replace the non-reducing terminal 2- O-methyl l-fucosyl residue and the 3,4-linked l-fucosyl residue, respectively, that are present in wild-type RG-II. Furthermore, we found that a terminal non-reducing l-galactosyl residue, rather than the previously reported d-galactosyl residue, is present on the 2- O-methyl xylose-containing side chain of RG-II in both wild type and mur1 plants. Approximately 95% of the RG-II from wild type and mur1 plants is solubilized as a high-molecular-weight (>100 kDa) complex, by treating walls with aqueous potassium phosphate. The molecular mass of RG-II in this complex was reduced to 5-10 kDa by treatment with endopolygalacturonase, providing additional evidence that RG-II is covalently linked to homogalacturonan. The results of this study provide additional information on the structure of RG-II and the role of this pectic polysaccharide in the plant cell wall.

Arabidopsis↗