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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The morphology of endothelial cells during the induction of atherosclerosis in the descending aortic arch of the hypercholesterol rabbit was studied in situ by scanning electron microscopy (SEM) following silver staining, fixation at physiological pressure, and air-drying of specimens- The earliest deviations from normal endothelial morphology were observed 3 weeks after starting to feed a semi-synthetic diet containing 20% beef fat and 0.2% cholesterol. These were (1) the occurrence of brightly silver stained (argyrophilic) cells, (2) areas of irregularly shaped cells which were often larger and more weakly stained than normal cells and (3) increased incidence of stigmata and stomata associated with the irregular cells. After 6 weeks of hypercholesterolaemia, similar changes were present in the endothelium, but were often also associated with sub-endothelial swelling. These represented the first atherosclerotic lesions. Following 12, 20 and 24 weeks of hypercholesterolaemia, larger raised macroscopic lesions were observed which were always endothelialized. Endothelial morphology and lesion topography suggested that early fatty streaks were composed of numerous focal swellings. In addition to the abnormal endothelial morphology noted at 6 weeks, endothelial cells overlying more advanced lesions became rounded in outline.
Atherosclerosis 1977 Jun
PMID:Aortic endothelial cell morphology observed in situ by scanning electron microscopy during atherogenesis in the rabbit. 7 Nov 55

A single injection of endotoxin P45 Poly Serratia marcescens was used to induce endothelial injury in rabbits. The aortic endothelium was examined by Scanning Electron Microscopy (SEM), at various times after administration of endotoxin, using the technique of silver staining and pressure fixation. Within one hour after injection, some endothelial cells were curled-up and spindle-shaped in appearance. Areas of aorta devoid of endothelial cover were occasionally observed and platelets were sometimes found adhering to these sites. Two and four weeks after initial injury no spindle-shaped cells were found. Instead, some endothelial cells were heavily stained with silver. Small denuded zones were still found and these were surrounded by brightly silver-stained cells. This study confirms that endotoxin rapidly causes endothelial injury and suggests that regenerating endothelial cells which were formed following injury are avidly stained by silver salts and appear as bright cells by SEM.
Atherosclerosis 1977 Mar
PMID:Scanning electron microscopy: morphology of aortic endothelium following injury by endotoxin and during subsequent repair. 32 78

Vascular casts of the rat aorta were made using modified Batson's No. 17 anatomical corrosion compound. The outline of the silver-stained endothelial cell boundaries were clearly visible on the cast when examined using both scanning electron and light microscopy. The physical properties of the injectate were determined. The exothermic nature of the polymerization of the injectate did not grossly damage the endothelial cells. A method was developed for recovery, without damage, of the arterial tissue surrounding the cast. The technique of vascular casting appears to be a powerful tool for the study of the arterial endothelium which avoids shrinkage artifacts and maintains 3-dimensional geometry.
Atherosclerosis 1979 Dec
PMID:Vascular casting. A new method for the study of the arterial endothelium. 51 48

Vascular casts were made of rabbit aortas by infusing Batson's No. 17 anatomical corrosion compound into the artery at physiological pressure. The arterial tissue was then digested with sodium hydroxide and the cast viewed by scanning electron microscopy (SEM). Outlines of the endothelial cells and their silver stained boundaries were clearly visible. Cell nuclei and fine surface detail were also discernible. In EDTA damaged arteries, injured endothelial cells and platelets could also be observed in the vascular casts.
Atherosclerosis 1977 Dec
PMID:A scanning electron microscopic study of arterial endothelial cells using vascular casts. 59 54

Five young male New Zealand White rabbits were fed a semi-synthetic diet containing 0.2% cholesterol for 2 weeks and a control group of 5 animals was fed a normal stock diet. All animals were then injected intravenously with a single dose of endotoxin from Serratia marcescens (200 microgram/kg body weight) and continued on their respective diets for a further 4 weeks. The aortas were then stained with silver nitrate and fixed under pressure for Scanning Electron Microscopy (SEM). Argyrophilic endothelial cells were present in both groups of animals 4 weeks after endotoxin injections. In the cholesterol-fed animals, however, these cells were often covered with pits and craters. These findings suggest that the hypercholesterolaemia may affect the regeneration of arterial endothelial cells.
Atherosclerosis 1978 Apr
PMID:Distortion of endothelial repair. The effect of hypercholesterolaemia on regeneration of aortic endothelium following injury by endotoxin. A scanning electron microscope study. 66 89

The luminal surface of fatty lesions of atherosclerosis was viewed by scanning electron microscopy (SEM). Endothelial cells were outlined by staining intercellular junctions with silver and the aortas were fixed in situ at physiological pressure. When aortas were dehydrated by passage through organic solvents followed by critical point drying from liquid CO2, there was considerable disruption of the luminal surface and it was not possible to correctly interpret the morphological integrity of the endothelium. In contrast, simple air-drying of aortas, without solvent dehydration after fixation, allowed the integrity of the cell layer overlying the lesion to be evaluated. The success of this technique was attributed to the retention of arterial lipids during dehydration of the tissue.
Atherosclerosis 1976 Oct
PMID:Scanning electron microscopy in the evaluation of endothelial integrity of the fatty lesion in atherosclerosis. 79 Dec 98

The luminal surface of normal rabbit aorta was examined by scanning electron microscopy (SEM) after outlining endothelial cells by staining intercellular junctions with silver. When aortas were fixed in situ at physiological pressure before processing for SEM, a reliable assessment of the morphological integrity of the endothelium was possible. In contrast, when aortas were excised and placed in fixative, contraction of the sub-endothelial structures made interpretation of endothelial integrity difficult.
Atherosclerosis
PMID:Scanning electron microscopy: arterial endothelial integrity after fixation at physiological pressure. 114 38

The en face organization of human aortic endothelium in zones of low (LP) and high (HP) probability of sudanophilia was examined in preparation impregnated with silver nitrate. It is found that the heterogeneity of endothelial cells (EC) by area is "random" or "clusterized". In the latter case the major part of small and medium-sized EC (less than 800 microns 2) is associated in distinct groups ("clusters") and form foci with high monolayer density. The luminal surface outside the clusters was formed by preferentially large and giant EC. Clusterized endothelium was found with statistically significant higher frequency in HP zones of both "normal" and "atherosclerotic" vessels. The maximum clusterization of EC was revealed on the shoulder region and on the periphery of atherosclerotic plaques which was speculated to be a growth zone of the lesion. It is suggested that the appearance of clusterized endothelium is associated with the active development of atherosclerosis.
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PMID:[The morphological and functional characteristics of the human aortic endothelium. I. 2 variants of the organization of the endothelial monolayer in atherosclerosis]. 172 7

The thickened subendothelium of brain arteries that is characteristic of atherosclerosis was assessed for the directional organization of the two main birefringent components, smooth muscle cells and collagen. Thirty-three arteries from 16 autopsy cases were pressure fixed at 30, 60, 110, and 200 mm Hg, sectioned at a thickness of 7 microns , and stained with silver impregnation to enhance tissue birefringence. The intended focus of the study was on muscle organization, but it also included the collagen among the cells because of the coalignment of the two tissues and their similar staining properties for polarized-light microscopy. The birefringent medial fabric at all pressures was circumferentially oriented, with a mean deviation of the 33 sections of 1.4 degrees from circumferential with an average circular standard deviation of 3.5 degrees, thereby showing remarkable coherence. In contrast, the subendothelium showed great variability both in thickness and in organization. Many arteries had no measurable subendothelium, and others had as much as 100%, with some atherosclerotic lesions as much as 300% of the medial width. Measurements from the subendothelium revealed a helical arrangement of tissue, often divided into separate regions, with a balance of left- and right-handed helical components and generally with lower pitch angles in the layers adjacent to the lumen. The average circular standard deviation within individual subendothelial layers was 14.5 degrees.
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PMID:Fabric organization of the subendothelium of the human brain artery by polarized-light microscopy. 202 6

Management of epistaxis is directly related to the site of the bleeding. Anterior nosebleeds are the least dangerous and the most common, especially among children. Sinus disease, colds, allergies, abrupt temperature changes and dry heat produce fragile and hyperemic nasal mucosa that bleeds easily with nose blowing or mild abrasion. Anterior epistaxis can be reached easily and stopped by pinching the nostrils, applying silver nitrate cautery or lightly packing the anterior nose. Posterior epistaxis may be severe and may be more difficult to locate and control. Occurring more often in the elderly, posterior nosebleeds are frequently associated with hypertension, atherosclerosis and conditions that decrease platelets and clotting function. Visualization of the bleeding site is enhanced by proper positioning of the patient, use of topical vasoconstricting anesthesia and suctioning. Anterior and posterior nasal packing, hospitalization, antibiotics and close follow-up may be required to control posterior nosebleeds.
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PMID:Management of anterior and posterior epistaxis. 204 44


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