Biomedical subjects

B Marsan

Publications and source records attributed to B Marsan.

4 recordsLinked to original sources

PubMed2000

Slimgraft: a percutaneous endovascular graft system.

PURPOSE: To describe an in vitro feasibility trial of a new percutaneous endograft delivery technique. METHODS AND RESULTS: A water flow model of 9-mm (inner diameter) transparent plastic tubing was used to test the feasibility of sequentially delivering the components of an endograft through a 7-F sheath for assembly in situ. The tubular endovascular graft was fabricated from a 10-mm x 68-mm Wallstent and 50-microm-thick Dacron graft. The graft material was formed into a tube, attached with a suture to a guidewire, and delivered into the plastic tubing. The Wallstent was then delivered through the tubular graft and deployed, affixing the graft to the plastic tube wall. In 4 trials, only 1 attempt was not successful. CONCLUSIONS: These concepts and techniques may have implications in the development of percutaneously deliverable endovascular grafts.

Blood Vessel Prosthesis↗

PubMed1996

Nicotine and cotinine stimulate secretion of basic fibroblast growth factor and affect expression of matrix metalloproteinases in cultured human smooth muscle cells.

PURPOSE: We have recently shown that nicotine and its metabolite cotinine are mitogenic for smooth muscle cells in vitro. In the present study, we examined the effect of nicotine and cotinine on the production of growth factors and the expression of matrix metallo-proteinases in smooth muscle cells. METHODS: Smooth muscle cells were harvested from human arteries and grown in culture. Subconfluent cultures were incubated for 24 hours in M199 containing 0.1% fetal bovine serum with or without nicotine or cotinine at concentrations ranging from 10(-9) mol/L to 10(-6) mol/L. The supernatants and cell lysates were assayed by enzyme-linked immunosorbent assay for basic fibroblast growth factor (bFGF), tumor necrosis factor alpha (TNF-alpha), platelet-derived growth factor AB (PDGF-AB), and transforming growth factor beta (TGF-beta). Matrix metalloproteinase expression was determined in subconfluent cultures incubated in albumin with or without nicotine or cotinine at 10(-8) mol/L and 10(-7) mol/L for 6, 12, 18, 24 and 36 hours. Northern blot analyses were performed with human cDNA probes for collagenase-1, stromelysin-1, gelatinase A, gelatinase B, and triose phosphate isomerase. Blots were quantified by phosphor-imaging techniques. RESULTS: Both nicotine and cotinine stimulated the production and secretion of bFGF in a dose-dependent manner. PDGF, TNF-alpha, and TGF-beta secretions were not significantly affected by nicotine or cotinine. Collagenase was up-regulated by nicotine at 18 and 24 hours (4.5-fold to 5.8-fold) and by cotinine at 18 hours (from 5.0-fold to 29-fold). Stromelysin-1 was up-regulated by nicotine and cotinine at 12 and 18 hours (1.5-fold to 7.0-fold). Gelatinase A generally peaked at 12 hours and was up-regulated by both agents (2.0-fold to 6.5-fold). CONCLUSION: Nicotine and cotinine enhanced the production of bFGF, a major mitogen for smooth muscle cells, and up-regulated the expression of several matrix metalloproteinases that are critical in cell migration. These data demonstrate mechanisms by which smoking may contribute to the development of intimal hyperplasia, atherosclerosis, and aneurysms.

Animals↗

PubMed1994

Esophageal carcinoma. The unusual variants.

The clinical behavior and response to therapy of rare histologic variants of esophageal carcinoma are unclear. To evaluate the results of therapy in this group the records of 29 patients treated between 1949 and 1991 with primary rare histologic variants of esophageal carcinoma were retrospectively reviewed. This group represented 1.2% of 2454 cases of esophageal carcinoma treated between 1949 and 1991 and included mucoepidermoid (n = 14), small-cell (n = 12), adenoid cystic (n = 2), and carcinosarcoma (n = 1) carcinomas. Treatment for localized disease consisted of esophagectomy in five of seven patients with mucoepidermoid carcinoma, two of six patients with small-cell carcinoma, two of two patients with adenoid cystic carcinoma, and one of one patient with carcinosarcoma. Patients with stage IV mucoepidermoid carcinoma were treated predominately with radiation therapy (5/7). The majority of small cell carcinomas were treated with multiagent chemotherapy (10/12). The 1- and 3-year disease-specific survivals were 54% and 9% for mucoepidermoid carcinoma (median survival, 5 months) and 16% and 0% for small-cell carcinoma (median survival, 7 months), respectively. Patients with stage III mucoepidermoid carcinoma (median survival, 20.5 months) compared with those with stage III small-cell carcinoma (median survival, 6.2 months) had a significantly longer duration of survival (p < 0.05). Distant disease was present in 86% of patients in whom recurrence developed after esophagectomy Esophagectomy is standard therapy for localized carcinomas of the esophagus. Small-cell carcinoma appears to be a more aggressive variant of carcinoma and is most commonly treated with chemotherapy.

Adult↗

PubMedDate not supplied

A safety net to prevent embolization during interventional procedures: work in progress.

PURPOSE: In vitro evaluation of three prototype devices designed to trap emboli that are generated by intravascular procedures. MATERIALS AND METHODS: Three prototypes of the safety net were tested in a water flow model. Angioplasty of human endarterectomy specimens was performed upstream of the device (n = 8). In other tests, polyvinyl alcohol particles were injected into the water flow model upstream of the device (n = 15). The safety nets and the effluent that passed through them were examined for embolic particles. A third prototype was tested (n = 5) to evaluate whether the device could be deployed and retrieved as designed. RESULTS: The safety net was able to trap debris released by angioplasty of endarterectomy specimens in every case. Most, but not all, polyvinyl alcohol particles were trapped by the safety net. Four of five devices tested were deployed and retrieved as designed. One became caught in the introducing valve, which prevented deployment. CONCLUSION: The vascular safety net is effective in trapping small volumes of emboli. It can be deployed and retrieved as designed.

Angioplasty↗