Showing papers by "Joseph H. Rapp published in 2003"
TL;DR: Hundreds of thousands of microemboli can be shed during carotid angioplasty, andFragments from calcified plaques cause greater levels of infarction than fragments from fibrous plaques, although ischemia is common with both fragment types.
Abstract: Background and Purpose— To determine the importance of emboli not trapped by carotid angioplasty filtration devices, we examined fragments <100 μm released with ex vivo angioplasty and asked if fragment composition and size correlated with brain injury. Methods— Human carotid plaques (21) were excised en bloc, and ex vivo carotid angioplasty was performed. Eight plaques were selected as either highly calcified (4) or highly fibrotic (4) by high-resolution MRI (200 μm3). Fragments were counted by a Coulter counter. Before injection into male Sprague-Dawley rats, fragments from calcified and fibrotic plaques were sized with 60-, 100-, and 200-μm filters. Brain ischemia and infarction were assessed by MRI scans (7-T small-bore magnet) and by immunohistologic staining for HSP70 and NueN. Results— All 5 animals injected with 100- to 200-μm calcified fragments had infarctions. One was lethal. After injection of 60- to 100-μm calcified fragments, 7 of 12 animals had cerebral infarctions, whereas only 1 of 11 had...
91 citations
TL;DR: In this paper, a meal containing 400 mg cholestan-5alpha,6 alpha-epoxy-3beta-ol (alpha-epsoxy cholesterol) was fed to six controls and three subjects with Type III hyperlipoproteinemia.
79 citations
TL;DR: Barriers to AV fistula placement can exist at the levels of the surgeon and surgical center, respectively, and future strategies to improve AV Fistula placement rates should target surgeons and surgical centers in addition to patients, nephrologists, and primary care providers.
69 citations
TL;DR: The carotid phantom experiments showed that the imaging parameters of CE-MRA, particularly the plane on which frequency encoding gradients were applied, reduced signal acquisition at the area of stenosis, and demonstrated that CE- MRA parameters must be retooled if the method is to be considered reliable for determination of severity of carotids artery stenosis.
54 citations
TL;DR: Fourier transform infrared spectroscopy using attenuated total reflectance (FTIR-ATR) was used to assess and analyze the biochemical properties of human atherosclerotic plaques and demonstrated the evolution of lipid peaks, fibrous tissue peaks, and the phosphate calcification band within the plaques.
Abstract: The behavior of vulnerable atherosclerotic plaques is believed to be closely related to plaque composition. There is a need for an effective in vivo technique for examining plaque constituent properties. In this study, Fourier transform infrared spectroscopy using attenuated total reflectance (FTIR-ATR) was used to assess and analyze the biochemical properties of human atherosclerotic plaques. FTIR spectra clearly revealed prominent spectral features corresponding to plaque constituents of interest: the 2930 cm−1 and 2850 cm−1 peaks (indicating the presence of lipids), the 1730 cm−1 peak (lipid esters), the 1550 cm−1 and 1650 cm−1 peaks (fibrous tissues), and the 1100–1000 cm−1 broad phosphate peak (calcification). Spectral data examined on a qualitative basis correlated well with both gross tissue anatomy and histologic features. Gross spatial mappings of tissue sections of both lipidic and calcified plaques were performed. Spectra from various regions of the plaques demonstrated the evolution of lipid peaks, fibrous tissue peaks, and the phosphate calcification band within the plaques. Histologic analysis corroborated the spectral findings in this study. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 197–206, 2003
24 citations
TL;DR: Improvements in this modality will result in continued improvement in the authors' ability to define the vascular lumenal edge and give the added advantage of in vivo plaque imaging.
9 citations
TL;DR: During retrospective review of the preoperative imaging studies, the second internal carotid artery lumen was identified in 3 patients and was correctly identified in only 1 patient preoperatively.
3 citations