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At least 37 records · Page 2Linked to original sources
PubMed1990

Blood vessel invasion in gastric carcinoma.

In an effort to identify factors in primary tumors that would predict liver metastases, we retrospectively reviewed 102 patients with gastric cancer, and their tissue blocks were restained. New staining methods for elastin and endothelium were used to identify intratumoral vessels. Blood vessel invasion, thus detected, was analyzed quantitatively, as well as qualitatively, according to the location of invasion, the size of the involved vessel, and the mode of invasion. The invasion was then compared with the presence of liver metastasis by the chi 2 test, the Mann-Whitney U test, and the Student t test. Discrimination analysis of factors significantly correlated with liver metastasis was performed with linear discrimination function to identify a predictive model for liver metastasis. Significant differences in qualitative frequency of blood vessel invasion (p less than 0.01), the number of lymph node metastases (p less than 0.05), and the depth of tumor invasion (p less than 0.05) were found in those patients in whom liver metastasis developed, as compared with 5-year disease-free survivors. Quantitative analysis of blood vessel invasion revealed eight other factors correlated with liver metastasis; frequency of blood vessel invasion in the 0.01 to 0.1 mm and 0.1 to 1 mm diameter vessels, in the forms of complete, partial tumor thrombi, and vessel wall invasion, in the submucosa and the subserosa, and the number of anatomic stomach layers involved. Application of the discrimination coefficient to these factors allows prediction of liver metastasis with 81.8% sensitivity, 85.3% specificity, and 83.6% accuracy. Liver metastasis can be predicted from the qualitative and quantitative examination of blood vessel invasion within the primary tumor by the use of an elastic fiber stain.

Capillaries↗
PubMed2000

Mg(2+)-induced endothelium-dependent relaxation of blood vessels and blood pressure lowering: role of NO.

In vitro extracellular Mg(2+) concentration ([Mg(2+)](0)) produces endothelium-dependent and endothelium-independent relaxations in rat aorta in a concentration-dependent manner. These relaxant effects of Mg(2+) on intact rat aortic rings, but not denuded rat aortic rings, were suppressed by either N(G)-monomethyl-L-arginine (L-NMMA), N(omega)-nitro-L-arginine methyl ester (L-NAME), or methylene blue. The inhibitory effects of L-NMMA and L-NAME could be reversed partly by L-arginine. [Mg(2+)](0)-induced dilatation in vivo in rat mesenteric arterioles and venules was almost completely inhibited by N(G)-nitro-L-arginine and L-NMMA. Removal of extracellular Ca(2+) concentration ([Ca(2+)](0)) or buffering intracellular Ca(2+) concentration in endothelial cells, with 10 microM 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM, markedly attenuated the relaxant effects of Mg(2+). Mg(2+) produced nitric oxide (NO) release from the intact aortic rings in a concentration-dependent manner. Removal of [Ca(2+)](0) diminished the increased NO release induced by elevated levels of [Mg(2+)](0). In vivo infusion of increasing doses (1-30 microM/min) of MgSO(4), directly into the femoral veins of anesthetized rats, elicited significant concentration-dependent sustained increases in serum total Mg and concomitant decreases in arterial blood pressure. Before and after employment of various doses of MgSO(4), intravenous administration of either L-NMMA (10 mg/kg) or L-NAME (10 mg/kg) increased (i.e., reversed) the MgSO(4)-lowered blood pressure markedly, and intravenous injection of L-arginine restored partially the increased blood pressure effects of both L-NMMA and L-NAME. Our results suggest that 1) small blood vessels are very dependent on NO release for Mg(2+) dilatations and 2) the endothelium-dependent relaxation induced by extracellular Mg(2+) is mediated by release of endothelium-derived relaxing factor-NO from the endothelium, and requires Ca(2+) and formation of guanosine 3',5'-cyclic monophosphate.

Animals↗
PubMed1997

Interactions between glial progenitors and blood vessels during early postnatal corticogenesis: blood vessel contact represents an early stage of astrocyte differentiation.

The post-neurogenic period in the mammalian neocortex is characterized by the growth of astrocyte and oligodendrocyte populations and their incorporation into the network of the developing central nervous system (CNS). Many of these glial cells originate as progenitors in the subventricular zone (SVZ) and then migrate into white and gray matter before differentiating. What determines the specific cellular fate of progenitors in vivo is not known, however. In examining the early stages of gliogenesis from progenitors in the SVZ, we noted that interactions with cortical blood vessels took place at what appeared to be an early stage of glial differentiation. We have examined in more detail the interactions of progenitors with blood vessels in the early postnatal rat neocortex after labeling progenitors in vivo with a LacZ-encoding retrovirus. These early interactions are accompanied by an increase in intermediate filament expression, consistent with astrocytic differentiation. Because astrocytes interact with blood vessels and pia, we suggest that such contact represents an early stage in astrocytic differentiation. Furthermore, since angiogenesis and astrogenesis occur over a similar period, the growth of blood vessels may even play a role in the selection of astrocytic fate by a progenitor. As vessel growth slows, fewer progenitors may be directed toward an astrocyte fate, allowing more to differentiate into oligodendrocytes, perhaps explaining the shift from astrocyte genesis to oligodendrocyte genesis during early postnatal cortical development.

Animals↗
PubMed1984

The nerves to blood vessels supplying blood to nerves: the innervation of vasa nervorum.

Noradrenergic, serotoninergic and peptidergic nerves have been demonstrated in perivascular plexuses of vasa nervorum of sympathetic, parasympathetic and somatic nerve trunks. 5-Hydroxytryptamine-, vasoactive intestinal polypeptide- and substance P-containing fibers were found by immunohistochemistry to variable extents in whole mounts of the epineurium of sciatic, vagus and paravertebral sympathetic chains of rabbits. Innervation increased with age. This suggests an hitherto unsuspected role for these vasoactive substances in normal blood flow to nerves and in the genesis of experimental and human neuropathies.

Age Factors↗
PubMed2006

The effect of VEGF on blood vessels and blood cells during Xenopus development.

Vascular endothelial growth factor (VEGF) is known to play an essential role in vascular development. We have overexpressed VEGF122 or VEGF170, which are equivalent to mouse VEGF120 and VEGF164, in developing Xenopus embryos. Overexpression of VEGF170 but not VEGF122 demonstrated an absence of expression of hematopoietic markers alpha-globin and GATA-1 but only in the posterior portion of the blood island. Interestingly, strong signals of endothelial markers, msr, fli-1, and tie-2, were detectable in those regions, instead of hematopoietic markers. These results suggested both that injection of VEGF170 resulted in disturbance of vasculogenesis in the posterior portion of the blood island, with excessive production of endothelial cells at the expense of blood cells, and that the anterior and posterior portions of the VBI may have distinct characteristics.

Animals↗
PubMed1998

Blood vessels and red blood cells preserved in dinosaur bones.

Dinosaur bones, 80 million years old, were studied in the scanning electron microscope, and subjected to X-ray microanalysis. Samples for the investigations were prepared according to specially elaborated, and simultaneously described methods. Analysed were (a) the morphological structure of the blood vessels and (b) the remains of their contents. The walls of the blood vessels were found to be morphologically identical with those in present-day reptiles. Bodies were found at several places inside the vessels which strongly remind one of erythrocytes in modern bones. X-ray microanalysis of places where these bodies were accumulated revealed much higher levels of iron, than at any other regions of the blood-vessel wall. Further analysis of the "dinosaur erythrocyte" iron content could be a starting point for the possible determination of oxygen in the earth's atmosphere, 80 million years ago.

Animals↗
PubMedDate not supplied

An ultrastructural study of blood vessels in peripheral nerves of leprosy patients: blood vessels in peripheral nerves.

Ultrathin sections of nerves of tuberculoid and lepromatous leprosy were examined in an electron microscope for changes in endoneural blood vessels. In the tuberculoid nerves, hypertrophy of endothelial cells was the most prominent feature. This was to such an extent that the lumen of blood vessel was often closed. Endoneural blood vessels showed multilayers separated by collagen and ground substances. In contrast, in the lepromatous nerves, there was no hypertrophy of endothelial cells in the blood vessels and the lumen of the vessels was open. M. leprae were seen within the endothelial cells and these organisms were intact and probably viable. These observations suggest a possible involvement of endoneural blood vessels which may contribute to nerve damage in leprosy.

Endothelium, Vascular↗
PubMed1989

[The effect of neodymium yttrium aluminum garment laser on the cerebral blood vessel and blood brain barrier].

The effect of the laser energy to the cerebral vascular reactivity and the blood brain barrier. A Nd:YAG laser with 20 watt impacts of 0.5, 1.0, 2.5 and 5.0 seconds duration time were irradiated through the cranial window made at the parietal regions of anesthetized adult cats. The disruption of the blood brain barrier was examined by checking the degree of the extravasation of Evans blue dye administrated in the vein. The cortical vessel reactivity was observed through the cranial window and evaluated using an intravital microscope and a videoangiometer. The extravasation of Evans blue dye was seen uniformly extending from the histologically changed area into the surrounding tissue in all experiments. The extent of the extravasation of dye was 1 to 1.5 mm larger than the extent of the histologically changed area produced by laser irradiation. Pial arteries in the area with histological changes dilated markedly and some of them lost their blood stream. Pial arteries in the area of Evans blue extravasation, but outside it histological changes also dilated markedly. Furthermore, pial arteries within a distance of 200 to 400 microns from the edge of the Evans blue extravasation area also dilated moderately. A statistical estimation showed that the degree of dilatation of arteries in the area outside the histological change improved significantly in the time course of five minutes.

Animals↗
PubMed1998

Color Doppler sonography of normal breasts: detectability of arterial blood vessels and typical flow patterns.

In a prospective study, 200 healthy female breasts were examined using color Doppler sonography to study the detectability and the resistive indices (RIs) of arterial vessels. In each breast, we attempted to detect two to three vessels and recorded the frequency spectrum with RI of each vessel. Blood vessels (n = 522) could be demonstrated in 196 (98%) breasts. Continuous diastolic flow (RI < 1) was found in 520 (99.6%) vessels. The mean RI of premenopausal women was 0.64; that of postmenopausal women was 0.70. This difference is highly statistically significant (p < 0.0001), but there is a marked overlap between the RIs of both groups. The variation in RI values of all women (up to 0.45), as well as in the breasts of the same woman (up to 0.31), was considerable. We conclude that modern color Doppler devices permit the detection of blood flow in the breast with regularity. Continuous diastolic flow (RI < 1) is a typical flow pattern. The variations of RI between women, and even for the same woman, are remarkable. The mean RI of premenopausal women is lower than the value for postmenopausal women.

Arteries↗
PubMed1992

Amine oxidase enzymes of sheep blood vessels and blood plasma: a comparison of their properties.

1. A comparison between the biochemical properties of semicarbazide-sensitive amine oxidase (SSAO) activities has been made in sheep blood plasma and arterial wall. 2. The metabolism of benzylamine (BZ) by blood plasma was resolved into high affinity (Km 2.76 +/- 0.24 microM) and low affinity (Km 743 +/- 49 microM) activities. Spermidine metabolism was by a single component (Km 174 +/- 22 microM) and this amine reduced the metabolism of high concentrations of BZ. 3. A single component metabolised BZ in arterial homogenates (Km 11.3 +/- 1.3 microM) and which metabolised spermidine at a very slow rate. 4. Dopamine was deaminated by plasma SSAO and competed with both low and high concentrations of BZ. Dopamine also interfered with arterial metabolism of BZ. 5. These results suggest that there are two SSAO enzymes in sheep blood plasma, with one having similar properties to SSAO in the arterial wall.

Animals↗
PubMed2005

Profile of differentially expressed genes in blood vessels and blood cells of hyperlipidemia rats using suppression subtractive hybridization.

Platelets, macrophages, endothelial cells, and smooth muscle cells can all contribute to atherosclerosis. To investigate the molecular events leading to atherosclerosis involving platelets, macrophages, endothelial cells, and smooth muscle cells, we carried out suppression subtractive hybridization (SSH) to generate a profile of genes overexpressed in the aorta and blood cells in high fat diet rats. From 85 random SSH-cDNA clones, we have screened 23 clones by Northern blotting, which were scored as overexpressed in the aorta and blood cells in high fat diet rats compared to normal diet rats. Sequencing showed that the gene corresponded to the known gene in the public databases, previously shown to be overexpressed in atherosclerosis, heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF), and local production was seen in vascular smooth muscle and endothelial cells by RT-PCR and Western blotting. These results show that SSH provides a very efficient means to produce a profile of differentially expressed genes in atherosclerosis. The identified gene may provide novel points of therapeutic intervention and pathophysiological mechanisms in atherosclerosis.

Animals↗