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At least 379 records · Page 21Linked to original sources
PubMedDate not supplied

Idiopathic dilation of the ductus venosus: an unusual anomaly of the fetal blood vessels.

The ductus venosus (DV) is a blood vessel unique to the fetal circulation. It functions as a shunt between the umbilical vein and inferior vena cava by passing the hepatic microcirculation and shunting highly oxygenated blood to the brain and myocardium. The DV has received less attention than the ductus arteriosus; however, with modern ultrasonographic imaging, the DV is easily identified and is becoming a valuable diagnostic tool in the areas of maternal-fetal medicine. We report a rare case of idiopathic dilation of the DV that was diagnosed during routine ultrasounds. The presence of blood flow turbulence within the dilated area and the concern that blood vessels might rupture resulted in elective cesarean section at 34 weeks gestation. The infant was discharged after 14 days. Dilation of the DV, its size as well as the presence of turbulence in the dilated area might be important factors in determining the time of delivery and could contribute to a better outcome.

Dilatation↗
PubMed2006

[Effect of histamine on intracortical blood vessels of rats].

OBJECTIVE: To investigate histamine-induced changes of the intracortical vessels in the cortical slice of rat brain. METHODS: Immunohistochemistry was employed to detect the expression of H1 and H2 receptors in the intracortical blood vessels of rats. Histamine-induced constriction of the intracortical blood vessels of the brain slices was observed with differential interference contrast microscope. Measurements of the luminal diameter were made on-line during the course of the experiment and confirmed off-line from the stored images. In order to observe whether histamine H1 and H2 receptors affected histamine-induced constriction, the intracortical blood vessels in the brain slices were pre-treated with H1 receptor antagonist diphenhydramine and H2 receptor antagonist cimetidine. RESULTS: Expression of H1 and H2 receptors was detected in the intracortical blood vessels of the rat brain. Histamine (1-100 micromol/L) induced a concentration-dependent constriction from (1.48-/+0.67)% to (32.91-/+7.91)%. The reactions to each histamine concentration were significantly (P<0.01) different from each other, with the exception of the highest histamine concentrations (30 and 100 micromol/L) when maximal constriction due to histamine were observed (P>0.05). With pre-treatment of the slice with 10 micromol/L diphenhydramine, application of histamine did not elicit constriction. Pre-treatment of the slice with 10 micromol/L cimetidine did not completely inhibit but somehow significantly weakened vascular constriction in response to histamine treatment at 10 and 30 micromol/L (P<0.05). CONCLUSION: Histamine can induce constriction of the intracortical blood vessels, which is mediated by H1 receptor.

Animals↗
PubMedDate not supplied

X-ray images of small blood vessels in angiography: question of isoplanatism.

The basic theory of x-ray image formation of blood vessels, which is related to isoplanatism, is discussed. The x-ray intensity distributions of the blood vessel images are derived first for the actual case, which gives "correct" x-ray images obtained by the ray-tracing method. Secondly, as an approximation of the actual case, the image distributions are derived by the convolution method, which corresponds to an isoplanatic case. It is concluded that, under practical conditions, x-ray images of blood vessels are given approximately by a convolution integral of the object distribution, that is, the input x-ray pattern of the vessel exposed with a parallel x-ray beam, with the line spread function of geometric unsharpness. Therefore, this theory provides support for the experimental procedure commonly used in obtaining blood vessel images, and for the validity of applying in angiography the concept of the line spread function and the modulation transfer function of geometric unsharpness.

Angiography↗
PubMed2005

[Study of human smooth muscle cells seeding in biologic blood vessel matrix].

To explore the human smooth muscle cells seeding in blood vessel of minor pig after trypsin treatment and provide data for xenotransplantation and for using pig vessel in tissue engineering. HE and silver stain were used for checking the smooth muscle cells seeding in acellular blood vessel. The results showed that the smooth muscle cells seeding succeeded and the smooth muscle cells were in normal morphological distribution. These demonstrate that the pig aorta can be used for smooth muscle cells seeding, and hence for constructing new vascular grafts.

Animals↗
PubMed2003

[Experimental study of tissue engineered blood vessel with vascular endothelial cell and vascular smooth muscle cell].

OBJECTIVE: To investigate the feasibility to seed vascular endothelial cell(VEC) and vascular smooth muscle cell (VSMC) into tissue engineered blood vessel scaffold material. METHODS: 1. A blood vessel scaffold with a combined polymer was designed, which mainly is composed of rabbit VSMC and collagen with reinforcement by a non-spinning fabric mesh made of polyglycolic acid (PGA). 2. VEC were isolated from rabbit thoracic aorta by enzyme digestion methods and subcultured and purified. Then the cells were seeded into scaffold material. The morphological characteristics of tissue engineered blood vessel was analyzed by scanning electron microscopy. RESULTS: VEC could adhere well to the inner surface of the tissue engineered tubular scaffold material with a tenacity and elasticity. VSMC could sustain bioactivity of cell. CONCLUSION: Non-spinning PGA porous biodegradable materials coated with collagen is benefit for cells to adhere and grow. It will lay a foundation of a laminated structure of tissue engineered blood vessel.

Animals↗
PubMed1995

Expression of endothelin-1 gene in blood vessels of adult spontaneously hypertensive rats.

Endothelins are potent vasoconstrictor peptides produced by the endothelium of blood vessels and other tissues, which could play a potentially important pathogenic role in hypertension. In some hypertensive models, endothelin production in blood vessels is enhanced. We have therefore investigated endothelin-1 gene expression in arteries of 17-week old spontaneously hypertensive rats (SHR) with established hypertension and Wistar-Kyoto control rats (WKY). The abundance of endothelin-1 mRNA in aorta and mesenteric arteries was evaluated by Northern blot analysis. Endothelin-1 mRNA expression was found to be reduced in the aorta of SHR in comparison to the age-matched WKY, whereas it was similar in mesenteric arteries in both strains. These results agree with the vascular content of immunoreactive endothelin-1 which we previously reported, and indicate that reduced or normal vascular endothelin-1 content in SHR is not the result of rapid turnover of the peptide in SHR blood vessels. Together with normal plasma immunoreactive endothelin-1 and normal or reduced responsiveness of blood vessels of SHR to endothelin-1, this indicates that vascular endothelin-1 does not appear to play an important role in the pathogenesis of the elevation of blood pressure in this model of genetic hypertension.

Animals↗
PubMed2006

Increased angiogenesis and blood vessel maturation in acellular collagen-heparin scaffolds containing both FGF2 and VEGF.

An important issue in tissue engineering is the vascularisation of the implanted construct, which often takes several weeks. In vivo, the growth factors VEGF and FGF2 show a combined effect on both angiogenesis and maturation of blood vessels. Therefore, we hypothesise that the addition of these growth factors to an acellular construct increases blood vessel formation and maturation. To systematically evaluate the contribution of each scaffold component with respect to tissue response and in particular to blood vessel formation, five porous scaffolds were prepared and characterised, viz.: collagen, collagen with heparin, and collagen with heparin plus one or two growth factors (rrFGF2 and rrVEGF). Scaffolds were subcutaneously implanted in 3 months old Wistar rats. Of all scaffolds tested, the one with a combination of growth factors displayed the highest density of blood vessels (type IV collagen) and most mature blood vessels (smooth muscle actin). In addition, no hypoxic cells were found in this scaffold at day 7 and 21 (hypoxia inducible factor 1-alpha). These results indicate that the addition of both FGF2 and VEGF to an acellular construct enhances an early mature vasculature. This opens prospects for (acellular) tissue-engineered constructs in conditions as ischaemic heart disease or diabetic ulcers.

Animals↗
PubMed1992

Mechanical properties of fibrin adhesives for blood vessel anastomosis.

Various methods have been used for anastomosing, or attaching, two ends of a severed blood vessel together. The most common method, suturing, is tedious, can be time-consuming, and requires special training in microvascular surgery. Other methods, such as mechanical devices and lasers, have some problems as well. The use of fibrin adhesives for blood vessel anastomosis might eliminate some of the current problems by allowing a quicker, simpler, and more reliable method of attachment. Although mechanical studies have been conducted to determine fibrin glue properties in shear, tensile, and burst tests; most of these studies have used skin or intestinal tissue. Therefore, to evaluate the feasibility of using fibrin glue as an adhesive for blood vessel anastomosis, the mechanical properties of blood vessels joined with fibrin glue were examined using tensile and burst tests. High and low fibrinogen concentrations were tested after 5- or 45-min time periods. In addition, three clinical methods of attachment were compared: end-to-end anastomosis, vessel overlapping, and suturing. In this study, because the adhesive strength was not found to increase significantly after 5 min, setting times for fibrin glue may be short enough to make it a clinical option when compared to suturing. In addition, the higher fibrinogen concentration did not result in a significantly higher adhesive strength, indicating that the lower concentration fibrin adhesives may be of comparable strength to the higher concentrations for clinical applications.

Anastomosis, Surgical↗
PubMed1990

Permeability of intracranial blood vessels to endogenous serum albumin.

The blood-brain barrier to endogenous serum albumin labeled with Evans blue was studied by standard fluorescence microscopic techniques in cats. Systematic studies confirm that, except in certain well-known loci (hypothalamic median eminence, subfornical organ, area postrema, etc.), blood vessels within brain tissue are impermeable to endogenous albumin. But studies also demonstrate that in virtually all arteries at the base and over the surface of the brain and brain stem, labeled albumin passes readily through endothelium and the vascular wall to the adventitia. These observations are discussed in the context of current concepts of intracranial vascular permeability and, in terms of general biology, the possible consequences of the permeability to serum albumin of intracranial, extraparenchymal blood vessels on the composition and physiology of cerebrospinal fluid and in the pharmacokinetics of antibiotics, anticonvulsants, and antineoplastic and vasoactive agents.

Animals↗
PubMed1996

Blood vessel invasion is a major prognostic factor in resected non-small cell lung cancer.

BACKGROUND: We examined the prognostic value of histologic indices in non-small cell lung cancer with particular interest in major blood vessel invasion. METHODS: We studied 593 patients who had curative resection between November 1983 and December 1988. We determined the histology, T and N status, peritumoral lung tissue invasion, tumor stroma, necrosis, mitotic rate, and blood vessel invasion. RESULTS: The median patient survival of the whole series was 3.2 years, with a 5-year survival of 38.9%. In univariate analysis, a high T stage, a high percentage of necrosis, blood vessel invasion, and N stage significantly worsened the survival. In multivariate analysis, only blood vessel invasion and, less significantly, T stage and lymph node metastasis remained independent prognostic factors. CONCLUSIONS: These results highlight the negative prognostic value of blood vessel invasion in non-small cell lung cancer and suggest that blood vessel invasion, T stage, and node metastasis are three unrelated and distinctive characteristics of resected non-small cell lung cancer.

Analysis of Variance↗
PubMed1983

Pattern of glycosaminoglycan distribution in tissue and blood vessels of human placenta.

The composition of separate crude glycosaminoglycan preparations from placental tissue and corresponding villous blood vessels was investigated in normal human placentas at various stages of maturation and in placentas from diabetic, toxemic and insufficient pregnancies. The crude preparations were separated into individual glycosaminoglycans and identified by means of electrophoresis on cellulose acetate prior or after specific enzymatic or chemical treatments. Relative amounts of individual glycosaminoglycans were estimated by densitometric scanning of the alcian blue-reactive electrophoretic bands. Irrespective of the nature of placenta, the contents of uronic acid and neutral sugar were higher in the preparations derived from blood vessels, as compared to placental tissue. Hyaluronic acid, chondroitin sulfates, heparan sulfate and dermatan sulfate were found in both preparations. The proportion of dermatan sulfate was higher while that of heparan sulfate was lower in the blood vessel preparations, compared to placental tissue. It is suggested that both heparan sulfate and dermatan sulfate may function as anticoagulants in their specific locations, namely, the maternal sinuses and the villous fetal blood vessels. The type of the glycosaminoglycan present may also influence the permeability of the tissue.

Blood Vessels↗
PubMed1986

Three dimensional observation of the nerve fibers along the cerebral blood vessels.

Three dimensional observation of the nerve fibers along the cerebral blood vessels was investigated by scanning electron microscopy. Electron probe X-ray microanalysis was also performed in the cerebral blood vessels treated with peroxidase-antiperoxidase immunohistochemistry intensified by nickel ammonium sulfate. Nerve fibers (2-8 microns in diameter) formed a plexus on the outer surface of the adventitia. After branching, the nerve fibers penetrated the blood vessel adventitia. Substance P-immunoreactive nerve fibers showed a meshwork pattern in the outer layer of the adventitia, and vasoactive intestinal polypeptide (VIP)-immunoreactive nerve fibers revealed a spiral running pattern in the inner layer of the adventitia. Taken together with previous studies, these findings suggest that substance P nerve fibers in the cerebral arteries may not be related to arterial dilatation or constriction, but VIP nerve fibers may be vasodilative.

Animals↗
PubMed1998

Spatial distribution of diffuse, primitive, and classic amyloid-beta deposits and blood vessels in the upper laminae of the frontal cortex in Alzheimer disease.

The spatial distribution of the diffuse, primitive, and classic amyloid-beta deposits was studied in the upper laminae of the superior frontal gyrus in cases of sporadic Alzheimer disease (AD). Amyloid-beta-stained tissue was counterstained with collagen IV to determine whether the spatial distribution of the amyloid-beta deposits along the cortex was related to blood vessels. In all patients, amyloid-beta deposits and blood vessels were aggregated into distinct clusters and in many patients, the clusters were distributed with a regular periodicity along the cortex. The clusters of diffuse and primitive deposits did not coincide with the clusters of blood vessels in most patients. However, the clusters of classic amyloid-beta deposits coincided with those of the large diameter (>10 microm) blood vessels in all patients and with clusters of small-diameter (< 10 microm) blood vessels in four patients. The data suggest that, of the amyloid-beta subtypes, the clusters of classic amyloid-beta deposits appear to be the most closely related to blood vessels and especially to the larger-diameter, vertically penetrating arterioles in the upper cortical laminae.

Aged↗
PubMed1995

The relationship of granulomas to blood vessels in intestinal Crohn's disease.

It has been suggested that granulomatous vasculitis is a primary mechanism in the production of pathologic changes seen in Crohn's disease. We set out to investigate the relationship of granulomas to blood vessels and to confirm or refute previous reports of granulomatous vasculitis in Crohn's disease. Thirty paraffin embedded tissues from 11 patients with Crohn's disease were selected after examination of H&E stained sections for the presence of granulomas. Using an immunohistochemical method, various monoclonal antibodies were applied to sequential sections from each tissue to demonstrate vascular structures and granulomas. In three patients none of the granulomas occurred in association with blood vessels, in five a small proportion of the granulomas affected blood vessels, and in three granulomatous vasculitis appeared occlusive and significant. A total of 232 granulomas were identified, 22% of which were closely associated with blood vessels, which included both arteries and veins; 16% were perivascular, while 6% were intravascular. Perivascular granulomas did not surround blood vessels or invade the medial layers. They were asymmetric, suggesting that they originated by encroachment of nearby lymphatic or connective tissue granulomas. These results indicate that the granulomas of Crohn's disease are usually not associated with blood vessels; however, there is a minority of patients in whom vascular granulomatous inflammation may be important, although probably as a secondary phenomenon.

Adult↗
PubMed2000

Calcium phosphate precipitates augment adenovirus-mediated gene transfer to blood vessels in vitro and in vivo.

Adenovirus (Ad)-mediated gene transfer to blood vessels is relatively inefficient, probably because binding of adenovirus to the endothelium and adventitia seems to be limited. Association of calcium phosphate (CaPi) precipitates with adenovirus improves efficiency of gene transfer to some cells in culture and to mouse lung in vivo. In this study, we tested the hypothesis that CaPi is useful for adenovirus-mediated gene transfer to blood vessels. In fibroblast and endothelial cells in culture, Ad:CaPi coprecipitates greatly increased transgene expression. Ad:CaPi also enhanced transgene expression in both adventitia and endothelium of carotid arteries and aortae from rabbits studied ex vivo. After injection of Ad:CaPi into the cisterna magna of rabbits in vivo, the transgene product was markedly increased in leptomeninges of the ventral brain stem, including the adventitia of the basilar artery. We also examined mechanisms of enhanced gene transfer. Binding of adenovirus to fibroblast and endothelial cells in culture, and to the basilar artery in vivo, as determined using Southern blot analysis, was augmented by CaPi. Antibody to adenoviral fiber knob did not inhibit augmented transgene expression by Ad:CaPi. The finding suggests that improved adenoviral binding occurs primarily via a fiber-independent pathway. Thus, CaPi precipitates are useful for improvement of adenovirus-mediated gene transfer to blood vessels in vitro and in vivo.

3T3 Cells↗
PubMed1989

An improved immunofluorescence technique for the histological examination of blood vessel tissue.

Autofluorescence of elastic fibres in blood vessel samples is a common interference with the specific fluorescence of FITC-conjugated antibodies. Counterstaining with eriochrome black T changed the yellow-green colour of elastic fibres to dark red, thus turning a disturbing feature into a useful reference background. A second counterstain, p-phenylenediamine, visualized cell nuclei as an amber colour. To demonstrate the improvement of this staining technique, cryosections from blood vessel samples, derived from control veins, arteries and experimental aneurysms of different ages (15 to 99 month old) in 5 sheep, were stained with antibodies against procollagen III, collagen type IV, laminin, and nidogen. The specific distribution of these connective tissue components could now be related to the location of the elastic fibres and the cells (cell nuclei).

Aneurysm↗
PubMed1991

Mediation by adenosine of the trophic effects exerted by the sympathetic innervation of blood vessels.

Chemical or surgical sympathetic denervation of blood vessels causes marked changes of the effector cells. Since postganglionic sympathetic cotransmission by noradrenaline and adenosine 5'-triphosphate is well established, the role of these transmitters as putative trophic factors was investigated. Whereas noradrenaline was ineffective in preventing morphological changes due to denervation, both adenosine and N-ethylcarboxamido-adenosine totally prevented them. In conscious rats, the adenosine receptor antagonist dipropylsulphophenylxantine (DPSPX) caused alterations of the blood vessel wall similar to those described for denervation. These results strongly suggest that adenosine is the trophic factor of sympathetic innervation.

Adenosine↗
PubMedDate not supplied

Ultrastructural observations of small blood vessels in leprosy patients.

In lepromatous leprosy, blood vessels revealed the luminal protrusions of endothelial cells containing M. leprae and thickening of the basement membrane of endothelial and smooth cells. Endothelial projections with increased pinocytotic vesicles were more often encountered in lepromatous leprosy than in the other types of leprosy. On the other hand, in tuberculoid leprosy, the extensive rough endoplasmic reticulum suggesting protein synthesis was observed in the endothelial cells compared with the other types of leprosy and non-specific lesions. It seems that the blood vessels associated with hyperfunction and proliferation in the endothelium could aggravate the degenerative changes in peripheral nerve fibers including the Schwann cells.

Endothelium, Vascular↗