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At least 163 records · Page 9Linked to original sources
PubMed1998

Cryodamage of the vessel wall accelerates the development of atherosclerotic lesions in arterial vessels of Watanabe hyperlipidemic rabbits.

In the present study we developed an experimental model, resembling human atherosclerosis, by removing the endothelial layer in Watanabe heritable hyperlipidemic (WHHL) rabbits (10 months old) by application of cryodamage on the external surface of arterial vessels. In age-matched New Zealand white (NZW) rabbits, used as control, after two months following cryodamage, carotid artery and infrarenal segments of abdominal aorta did not show any particular change in the ultrastructure of vessel wall. In WHHL rabbits, two months after cryodamage, atherosclerotic lesions (fatty streaks and fibrous plaques) were observed in both arteries. Many lipid-laden endothelial cells, subendothelial foam cells and smooth muscle cells were found in cryodamaged areas. In some areas, the cap of plaques appeared to be thinned and ruptured. Increased number of collagen and elastic fibrils was also observed in atherosclerotic regions. We conclude that this simple technique on WHHL rabbits provides a model of atherosclerosis with a high degree of morphological similarity between the artificially-induced plaque and human atherosclerotic plaque.

Animals↗
PubMed1983

Differences in blood vessels between species: relation to differences in blood vessels of varying type within the same species.

1. Major differences in physiological and pharmacological responsiveness may be observed between blood vessels that differ either in anatomical type or in that they serve different organs or tissues. 2. The intrinsic properties of the vascular smooth muscle appears to differ little between species. No important differences in noradrenergic innervation have been observed, but major differences may exist in neural dilator systems. A few differences have been demonstrated that can be attributed to variations in the receptor population. No clear differences in local humoral mechanisms are known. There is, however, an insufficient number of strictly comparable studies in different species and it is likely that more differences will be found as our knowledge of vascular responsiveness is extended.

Animals↗
PubMed1993

Recipient vessels in head and neck microsurgery: radiation effect and vessel access.

Historical cohort analysis compared free-flap survival rates in 226 irradiated and 108 nonirradiated head and neck reconstructions. The failure rate for the irradiated flaps (3.5 percent) did not differ significantly from that for the nonirradiated group (2.9 percent). A case-control study of the failed irradiated flaps revealed infection and lag time between radiotherapy and surgery as the only factors significantly associated with free flap failure. Salvage techniques (vein grafting, cephalic transposition, and Corlett looping) for recruiting recipient vessels into radically ablated head and neck beds are reviewed.

Adult↗
PubMedDate not supplied

Influence of matrix size, vessel shape, vascular diameter, flow velocity, course of vessels on MR angiography.

Basic experiments were done to examine the influence of the extent of curve, direction of flow, vascular diameter, velocity of flow, and course of vessels on MR angiography. In the first experiment, two phantoms were constructed of vinyl tubing, a hairpin type and one with tubes bent to varying degrees. These phantoms were imaged in two matrices, different FOV, and of various velocities with a 1.5 Tesla system. Images of a normal volunteer were also obtained. In studies of the hairpin phantoms, a low intensity artifact appeared at the curve position, and the edge became fuzzy when the flow was perpendicular to the phase encoding direction. These phenomena were more apparent with a smaller matrix, smaller FOV, more gentle angle, larger diameter, and faster flow; in other words the component along the direction was dominant. In the phantom that used bent tubes, another low intensity artifact appeared on the medial side of the outflow portion. The results obtained from the volunteer corresponded well to those from the basic experiments. It was thought that the profile of flow was not well demonstrated due to the coarse matrix. In the second experiment, water flowed at various speeds through three-dimensional phantoms that were made of vinyl tubes of various diameters and directions. The phantoms were imaged with two- and three-dimensional time of flight and phase contrast angiography. The lower limits of detection of the phase contrast method were almost the same. In the coronal plane, the lower limit decreased to 2.5 mm for arteries and 9.5 mm for veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1979

[Histochemical and ultrastructural studies of the innervation of the lymph-vessel and blood-vessel wall. II. Cholinergic innervation].

Using the Acetylcholinesterase (AChE) tecnique applied to light and electron microscopy, was observed that the lymph vascular wall shows very few and inconstant AChE-positive fibers. The cholinergic fibers run prevalently longitudinal in the perivascular connective tissue, only brief segments show a loose network. The results are discussed and compared with blood vessels innervation.

Animals↗
PubMed1981

[Early results of percutaneous transluminal coronary vessel dilatation in single vessel disease. Comparison with drug treated or surgically treated patients, retrospective for dilatation suited patients].

The shortterm results (mean follow-up 0.9 years) in 61 patients with single vessel disease (1-VD) who had undergone percutaneous transluminal coronary angioplasty (PTCA) were compared with those in 33 patients with 1-VD treated medically and in 36 patients with 1-VD treated by bypass surgery. All medically and surgically treated patients had coronary artery stenoses which were classified in a retrospective analysis as suitable for PTCA. Initially there were no significant differences between the three groups with respect to functional impairment (NYHA class), incidence of prior myocardial infarction, left ventricular ejection fraction and localization of the coronary stenoses. Comparison of follow-up results at the end of the first year showed (1) that the NYHA class was reduced to a similar extent both in patients treated surgically and in those treated by PTCA, (2) that the NYHA class in the medically treated group was significantly greater than in the other two groups, and (3), that there was no difference among the three groups with respect to infarct and mortality rate.

Coronary Artery Bypass↗
PubMed1996

Blood vessel and lymphatic vessel invasion in resected nonsmall cell lung carcinoma. Correlation with TNM stage and disease free and overall survival.

BACKGROUND: The objective of this prospective study was to assess in 96 patients with resected nonsmall cell lung carcinoma (NSCLC) the prevalence of both blood and lymphatic vessel invasion (BVI and LVI) according to stage, as well as their prognostic value for disease free and overall survival. METHODS: BVI and LVI were evaluated by hematoxylin and eosin stains on surgical specimens after resection. Associations among variables were tested by Fisher's exact test or the chi-square test; prognostic values on time-failure data were analyzed by the log rank test and the multivariate Cox model. RESULTS: BVI was present in 52% of NSCLC cases and LVI in 59%. Venous but not arterial vascular invasion correlated with the T factor and pTNM, whereas LVI correlated with the N factor and pTNM. In univariate analysis, LVI but not BVI was associated with a short disease free interval (P = 0.0007) and poor survival (P = 0.0001). The estimated relative risk of death in patients with LVI was 3.2 compared with patients without LVI. In multivariate analysis, LVI and pTNM were additional predictors for poor disease free and overall survival. In this series, BVI had no prognostic value. CONCLUSIONS: The prevalence of BVI and LVI appeared high in patients with NSCLC, especially those with advanced pTNM stages. LVI was predictive of poor outcome, both time to recurrence and death.

Adenocarcinoma↗
PubMed2005

Inhibition of p53 during physiological angiogenesis in the hamster ovary does not affect extent of new vessel formation but delays vessel maturation.

Transcription factor p53 regulates the cell cycle and apoptosis and may impair angiogenesis by the deregulation of pro-angiogenic factors and the activation of anti-angiogenic factors. Our aim has been to elucidate further the role of p53 in physiological angiogenesis. By treating hamsters with the wildtype p53 inhibitor pifithrin-alpha (PFT) versus equivalent volumes of the vehicle dimethylsulfoxide, we showed a reduced p53 tissue protein level, a reduction of poly(ADP-ribose) polymerase and cleaved caspase-3 products, and a slightly increased proliferation of cell nuclear antigen and cyclin D1 by Western blot protein analysis of ovarian tissue. PFT further increased platelet-derived growth factor and did not influence vascular endothelial growth factor in female reproductive tissue. Despite these differences in tissue levels of proteins potentially involved in angiogenesis, in vivo fluorescence-microscopic analysis of freely transplanted ovarian follicles revealed comparable kinetics and an extent of revascularization with almost identical densities of network microvessels in both groups. However, follicles of PFT-treated animals exhibited enlarged diameters and higher volumetric blood flow within the newly formed microvessels. Less-dense basement membranes with unclear laminar structure and only a loose contact of pericytes to endothelial cells were also occasionally found, providing evidence of delayed maturation and impaired diameter control of microvessels. Thus, inhibition of wildtype p53 during physiological angiogenesis does not affect the extent of new vessel formation but may delay the maturation of newly formed microvessels.

Animals↗
PubMed1992

Long-term efficacy of triple-vessel angioplasty in patients with severe three-vessel coronary artery disease.

Between May 1982 and December 1988, a total of 103 patients underwent angioplasty of all three major coronary arteries at a single institution. Angiographic success was achieved in 334 of 352 vessels (95%) and in 441 of 460 lesions (96%). No patients required urgent bypass surgery, and none died during the procedure; six had non-Q wave infarctions. The mean length of follow-up time was 49 +/- 15 months (range 28 to 107 months). There have been 11 deaths, and one patient has undergone cardiac transplantation. Thirty-six patients had a clinical recurrence; 30 had repeat angioplasty and five had bypass surgery. Another nine patients eventually had bypass surgery after the clinical recurrence. At 48 months actuarial event-free rates are myocardial infarction, 98%; bypass surgery, 88%; and death, 89%. Of 86 current survivors, 58 are in functional class O to I, 21 are in class II, and seven are in class III.

Adult↗
PubMed1978

Small vessel vasculitis caused by hepatitis B virus immune complexes. Small vessel vasculitis and HBsAG.

In a comprehensive study of 80 patients with vasculitis, 4 had concurrent hepatitis B virus (HBV) infection. Polyarteritis nodosa was present in 2 and in the other 2, cutaneous vasculitis, presenting clinically as palpable or Henoch-Schönlein purpura. In one of these patients skin biopsies demonstrated granular deposits of IgM, C3, C4, and the hepatitis B surface antigen (HBsAg) and electron-dense deposits of aggregated 20-nm particles resembling HBsAg in postcapillary venules. Evidence for circulating HBsAg-immune complexes included increased serum Clq binding activity, decreased serum complement, and a cryoprecipitate containing both HBsAg and IgM anti-HBs. Aggregated 20-nm particles resembling intact HBsAg were also seen by negative staining electron microscopy of the serum cryoprecipitate. This patient fulfills all the criteria for a specific immune complex vasculitis caused by his immune response to a chronic HBV infection. These findings emphasize that HBV infection may be associated with small vessel vasculitis as well as polyarteritis nodosa, mixed cryoglobulinemia, and glomerulonephritis. A similar immune response to other viral infections may be expressed as palpable (Henoch-Schönlein) purpura also.

Adult↗
PubMed1998

Sex steroidal regulation of vessel permeability associated with vessel endothelial cadherin (V-cadherin).

In an attempt to understand the roles of cadherins in the placenta, mRNA expression and biological function of cadherins in 3A(tPA-30-1) cells (derived from human term placenta and transformed by SV40), and in HUV-EC-C cells (derived from the endothelial cells in human umbilical cord) were studied under the influence of sex steroids. Estradiol transiently decreased the endothelial cell barrier properties (ECBP) of HUV-EC-C cells, and progesterone reversed the changes induced by estradiol. However, neither estradiol nor progesterone demonstrated any effect on cell aggregation of either 3A(tPA-30-1) or HUV-EC-C cells. Estradiol transiently decreased the level of V-cadherin and its mRNA in HUV-EC-C cells, and progesterone reversed the level decreased by estradiol. However, neither estradiol nor progesterone demonstrated any effect on the level of E-cadherin mRNA in 3A(tPA-30-1) cells. Therefore, a sex steroidal role for placental development and function related to cadherins seems to focus on the endothelial cells, plausibly via vessel permeability for the utilization of placental products.

Antigens, CD↗
PubMed2002

Tumor hypoxia and blood vessel detection: an image analysis technique for simultaneous tumor hypoxia grading and blood vessel detection in tissue sections.

We have developed a multistage image analysis technique for the simultaneous segmentation of blood vessels and hypoxic regions in dual-stained tumor tissue sections. The algorithm, which is integrated in a task-oriented image analysis system developed on-site, initially uses the K-nearest neighbor classification rule in order to label the image pixels. Classification is based on a training set selected from manually drawn regions corresponding to the areas of interest. If the output image contains a significant number of misclassified pixels, the user has the option to apply a series of specific problem-designed routines (texture analysis, fuzzy c-means clustering, and edge detection) in order to improve the final segmentation result. Validation experiments indicate that the algorithm can robustly detect these biological features, even in tissue sections with a very low quality of staining. This approach has also been combined with other image analysis based procedures in order to objectively obtain quantitative measurements of potential clinical interest.

Algorithms↗
PubMed2006

An integrated automated analysis method for quantifying vessel stenosis and plaque burden from carotid MRI images: combined postprocessing of MRA and vessel wall MR.

BACKGROUND AND PURPOSE: We report the evaluation of a semiautomated method for in vivo assessment of the severity of carotid atherosclerosis with minimal user interaction that combines 3-dimensional contrast-enhanced magnetic resonance angiography (CE-MRA) and vessel wall magnetic resonance imaging (MRI). METHODS: Lumen and outer-wall contours were automatically detected, and stenosis and plaque burden were estimated. The method was tested on 22 subjects (352 postcontrast, T1-weighted cross sections and 3-dimensional CE-MRA). RESULTS: We observed good correlation with expert contours: lumen and outer-wall area (r=0.96) and the degree of stenosis (r=0.97). CONCLUSIONS: The fusion of MRA and MRI reduces user interaction and improves contour detection, providing reproducible parameters to assess the severity of atherosclerosis.

Aged↗
PubMed1992

Dimensions of the heart and great vessels in normal children. A postmortem study of cardiac ventricles, valves and great vessels.

Knowledge of normal heart dimensions is often needed in the planning of cardiac surgery in children. Attempts to define 'normal' have so far given varied and somewhat controversial results. The purpose of this study was to determine normal values for all heart measurements of clinical importance in children. Special interest was focused on the relationship between the diameters of the right and the left pulmonary artery (RPA abd LPA) and the descending thoracic aorta (DTA), defined as RPA/DTA+LPA/DTA, which is widely used in evaluating the feasibility of certain pediatric cardiac operations. The normal curve of this ratio during growth has not previously been presented in the literature. The observed data provide reliable normal values for the diameters of the great vessels and valves and the ventricular volumes of the heart.

Adolescent↗
PubMed1992

A comparison of vessel sensitivity and vessel constant in oxygen uptake determination with pure oxygen and air as gaseous media.

Air proved to be a superior gaseous medium to pure oxygen used for oxygen uptake study in the Warburg apparatus Recording of volume change (vessel sensitivity method) was the only correct method of recording the oxygen uptake. It is concluded that the volume change method should be followed for recording oxygen uptake by Warburg apparatus and pure oxygen should not be used as a gaseous medium.

Air↗
PubMed1988

Small vessel leg angiography for distal vessel bypass grafts.

To improve visualization of the small vessels for distal bypass grafting, arteriograms of the lower extremity were obtained in 187 patients by use of active warming of the extremities, selective distal positioning of the catheter for contrast agent injections, and intraarterial administration of tolazoline. With these techniques, satisfactory visualization was obtained for planning of operation, and in only one patient was an intraoperative arteriogram necessary before bypass grafts were placed.

Angiography↗
PubMed1987

[Possible participation of vessel wall kinins in regulating blood vessel tonus].

Extracts of mammalian arterial walls revealed a kinin-like biological activity resistant against proteolytic inactivation with trypsin but not chymotrypsin. Bradykinin was chromatographically determined as kinin existing in extracts from the rat aorta. Kallidin was found as well as bradykinin in human vessels. Metabolism of vasoactive kinins in the vascular wall seems to take part in control of circulation and blood pressure.

Animals↗