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At least 523 records · Page 29Linked to original sources
PubMed1985

Calcitonin gene-related peptide is present in mammalian cerebrovascular nerve fibres and dilates pial and peripheral arteries.

Calcitonin gene-related peptide (CGRP) is a novel 37-amino acid peptide occurring in neurones within sensory ganglia, in brain stem, as well as in the walls of blood vessels of peripheral organs. Pial arteries of cat showed a well-developed supply of CGRP-positive nerve fibres. The peptide was found to be a potent dilator of both pial and peripheral vessels of rabbit and cat, and of pial vessels from man. The dilatory effect was independent of the vascular endothelium and was not mediated through adrenergic, cholinergic or histaminergic smooth muscle receptors. The neurogenic vasoconstriction induced by electrical field stimulation was temporarily inhibited by CGRP, as studied in central ear arteries from rabbits. The results suggest that CGRP is a transmitter or modulator playing a role in the regulation of vascular tone.

Animals↗
PubMed1990

[Treatment of hypertension using angiotensin-converting enzyme inhibitors].

Angiotensin conversion enzyme inhibitors (ACE inhibitors) comprise a relatively new group of potent antihypertensives. They are today among the most used preparations for reducing blood pressure. ACE inhibitors may be used for treatment of almost all forms and degrees of hypertension. By reason of the reduction of the resistance in the peripheral vessels the blood pressure drops by 12-20 per cent, both at rest and during muscular effort, without diminution of the heart's pump function. The autonomic reflexes are unchanged and the circulation in the kidneys and the brain is retained. ACE inhibition does not result in fluid retention. In adequate doses the drugs are tolerated and give few side-effects provided that the patient is not dehydrated.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Distribution of vitronectin mRNA during murine development.

Vitronectin (Vn) is not only a major adhesive glycoprotein in plasma but also regulates cell-mediated proteolytic enzyme cascades, including the complement, coagulation, and fibrinolytic systems. This broad functional activity suggests that Vn may also play a critical role in development. To begin to investigate this possibility, we studied Vn gene expression during murine embryogenesis. In situ hybridization analysis of embryonic tissues revealed Vn mRNA primarily in the liver and the central nervous system (CNS). In the liver, Vn mRNA was detected by day 10, the level increasing at later developmental stages. In the CNS, Vn mRNA was also detected as early as day 10 and was confined to the floor plate. However, as development proceeded, high levels of Vn transcripts became prominent in the meninges of the cortex and spinal cord, and in close proximity to brain capillaries. The perikarya of most neurons lacked Vn mRNA. Unexpectedly, high levels of Vn mRNA were associated with capillaries of the CNS, but not with blood vessels of peripheral organs. These results indicate that Vn is expressed in a spatially and temporally distinct pattern during murine embryogenesis, and suggest that the Vn transcript may be a CNS-specific vascular marker.

Animals↗
PubMed1995

Localization of blood vessels and qualitative assessment of blood flow in ovarian tumors.

OBJECTIVE: To study the localization of blood vessels within a tumor and the shape of the flow curve as a method of assessing ovarian neoplasms. METHODS: We studied 39 patients with malignant tumors and 63 patients with benign ovarian tumors by means of vaginal color Doppler ultrasound, noting the localization of blood vessels in the tumors, the shape of the flow curve, and peripheral resistance. RESULTS: Blood vessels could be visualized in 95% of the malignant tumors and in 70% of the benign tumors. Blood vessels tended to be localized centrally (65 versus 5%) in malignant tumors and peripherally in benign tumors (65 versus 0%). A diastolic notch was seen in 89% of the benign tumors, but in none of the malignant tumors. The mean resistance index (RI) +/- standard deviation was 0.48 +/- 0.19 in malignant and 0.69 +/- 0.09 in benign tumors (P < .05). The corresponding values for the pulsatility index (PI) were 0.56 +/- 0.13 and 1.06 +/- 0.07, respectively (P < .01). CONCLUSIONS: Low RI and PI values are general indicators of tumor growth. The localization of blood vessels within an ovarian tumor and the presence or absence of a diastolic notch are the most useful variables in the evaluation of ovarian tumors.

Adult↗
PubMed2003

Piezoelectric sensor determination of arterial pulse wave velocity.

Arterial pulse wave velocity (APWV) is a measure of the elasticity (or stiffness) of peripheral arterial blood vessels. The pulse referred to here will be the pressure pulse as opposed to the flow pulse measured by ultrasound Doppler. The pressure pulse velocity varies over the range from about 12 m s(-1) to 15 m s(-1) in stiff peripheral arteries, whereas in normal arteries it has a velocity in the range of 7 to 9 m s(-1). The aim of this project was the development of a fast and easy to use system for the determination of peripheral arterial pulse wave velocity. The principle of the PWV measurement is based on simultaneous measurement of two pulse waves at two different positions, such as the radial artery at the wrist and the brachial artery just above the elbow. By determining the pulse transit time between these points and the distance measured between the two locations, pulse wave velocity may then be calculated. The pressure pulse detection is done by using two piezoelectric sensors which generate a measurable voltage at the output contacts if they are mechanically deformed. The deformation produced voltage is first amplified and filtered and then digitalized with a data acquisition card. The analysis of the data obtained from the sensors includes a filtering process, the calculation of the PWV with three different methods--foot-to-foot, cross-correlation and peak-to-peak-and the determination of the arterial pulse rate. Extensive measurements with human test subjects were carried out to optimize the techniques of data acquisition and analysis. For example, it was found that the best procedure was to hold the sensors in place using elastic straps alone. The data analysis was upgraded with an additional software module, which deletes, in effect, outriders or invalid measurements. With the optimized system, a series involving eight test subjects ranging in age from 22 to 32 years was completed (all normotensive). The arterial pulse wave velocities determined covered a range from 6 m s(-1) to 12 m s(-1), with an average standard deviation of less than 2.5 m s(-1) for individual results. These are slightly higher, but close to published APWV data. The results showed that reproducible results can be obtained with the existing PWV acquirement and analysis system.

Arteries↗
PubMed2006

Endothelial adhesion molecule expression is unaltered in the peripheral nerve from patients with AIDS and distal sensory polyneuropathy.

Some evidence suggests that endothelial dysfunction, including altered expression of cell adhesion molecules contributes to pathophysiology of nervous system disorders in the course of HIV infection. In this immunohistochemical study we investigated and compared the expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1) in peripheral nerve blood vessels from patients with distal sensory polyneuropathy (DSP) and control patients with other axonal neuropathies. Similar quantitative pattern of immunoreactivity was found in patients with DSP and controls. E-selectin and PECAM-1 immunostained vessels tended to increase in number only in patients with major CD4 cell depletion. The vascular endothelium of the peripheral nerve in HIV-infected subjects with DSP shows no changes facilitating the migration of infected or activated monocytes/macrophages into the nerve. These phenomena probably do not play a critical role in the development of axonal damage in DSP.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The ultrastructure of photochemically induced thrombi with embolization in a rat model.

BACKGROUND AND PURPOSE: Photochemical techniques, currently used in stroke and cancer research, produce endothelial damage and thrombosis. To further characterize these thrombi and to determine whether they embolize, we studied the ultrastructure of photochemically damaged carotid arteries and small vessels distal to the irradiated carotid. METHODS: The right carotid artery of 9 Wistar rats was irradiated with a laser (632 nm, 200 mW/cm2, 15 minutes) after the injection of the photosensitizing dye Photofrin II, 12.5 mg/kg. There were 6 additional control rats: laser only, 2 rats; dye only, 2; carrier only (5% dextrose), 1; and normal, 1. The carotid artery and cerebral arterioles were studied using scanning and transmission electron microscopy. RESULTS: Endothelial damage was present in all irradiated carotid arteries, and consisted of exposure of the subendothelium and the formation of a nonocclusive thrombus. Although most cerebral arterioles were normal, 32 of these vessels contained peripheral blood elements, with platelet or red blood cell aggregates present in 15. The endothelium adjacent to the aggregates was intact. A few scattered endothelial cells had been lost in the carotid artery of control animals (compatible with normal cell turnover), with a few platelets adhering to the exposed subendothelium. CONCLUSIONS: Aggregates of blood cells and platelets in cerebral vessels in the absence of endothelial denudation verifies embolism as the mechanism for cerebral vascular occlusion in this experimental model. The possibility of embolization distal to the site of photochemical irradiation has implications for potential applications of photochemistry for cancer treatment and the ablation of vascular malformations and/or aneurysms.

Animals↗