Publications by authors named "Keeley F"

Adaptive responses of rabbit common carotid arteries were examined after 70-80% reductions in blood flow produced by ipsilateral external carotid artery ligation. These flow reductions elicited growth inhibition of arterial wall tissue in immature rabbits. Specifically, experimental carotid arteries exhibited DNA levels significantly lower, by 35%, than contralateral control arteries 1 mo after external carotid ligation.

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The hyperextensible, fragile skin of two related horses was compared with the skin of eight normal horses. Skin sections were examined by light microscopy and transmission electron microscopy. The deep dermal layer of the dorsal abdomen was much thinner in the affected horses, and contained bundles of collagen fibers which were more loosely packed.

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An autogenous graft of tibial periosteum was sutured (with its cambium layer facing into the joint) to the base of a five by ten-millimeter full-thickness defect in the patellar groove of each of forty-five adolescent rabbits. The rabbits were randomly treated postoperatively by either four weeks of immobilization in a cast, intermittent active motion in a cage, or two weeks of continuous passive motion. One year postoperatively, the regenerated tissue from each rabbit was analyzed macroscopically, histologically, histochemically, and biochemically.

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Changes in elastin and collagen synthesis in the pulmonary artery wall, assessed both biochemically and ultrastructurally, were related to the development of progressive pulmonary hypertension induced by the toxin monocrotaline. Male Sprague-Dawley rats (200 to 225 gm) were injected subcutaneously in the hind flank with either monocrotaline (60 mg/kg) or an equivalent volume of saline and studied 8, 16 and 28 days later. At each time point, the right ventricle and left ventricle with septum were separated and weighed to follow the development of right ventricular hypertrophy.

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Glucocorticoids have been shown by others to increase the synthesis of elastin both in aortic tissue of embryo chicks and in cells derived from fetal ligamentum nuchae. This report describes the effects of hydrocortisone on the production of elastin in aortic tissue of developing chick embryos and chicks. While the effect of hydrocortisone on elastin synthesis is stimulatory in the 14 day chick embryo and the day-old chick, the same dose of this glucocorticoid has no effect on elastin production in the 7 day old chick and significantly inhibits synthesis of elastin in the 14 day old chick.

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A rectangular graft of autogenous tibial periosteum was sutured (with its cambium layer facing into the joint) onto the base of a five by ten-millimeter full-thickness defect in the patellar groove of each of 143 adolescent and adult rabbits. The rabbits were managed postoperatively by either immobilization, intermittent active motion, continuous passive motion for two weeks, or continuous passive motion for four weeks. When the animals were killed four weeks postoperatively, the contour of the patellar groove had been restored in all of the rabbits in the group that had had four weeks of continuous passive motion, and the newly formed tissue in all of the defects in this group had the gross, histological, and histochemical appearance of smooth, intact hyaline articular cartilage.

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This report describes an investigation of the effects of developing hypertension on the synthesis and accumulation of insoluble elastin in the thoracic aorta of young rats. Uninephrectomized male rats were made hypertensive by administration of deoxycorticosterone acetate and addition of 1% NaCl to their drinking water. Divergence of systolic blood pressures between treated and control animals and hypertrophy of the vessel began after about 2 weeks of treatment.

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alpha 2-HS-glycoprotein (HSGP) is a minor constituent of plasma with negative acute-phase reactant properties. HSGP has been shown previously to accumulate in the mineralized matrix of bone and dentin to concentrations substantially higher than those present in plasma. In addition, HSGP has also been found in experimentally induced dermal calcifications in animals.

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Currently available methods for quantitative analysis of type II collagen in studies of articular cartilage repair either require much larger samples than are available or are inaccurate and unreliable. A method of determining the percentage of type II collagen in small samples of articular cartilage (100 to 200 micrograms) by measuring the spectrophotometric densities of specific cyanogen bromide peptide bands from mixtures of types I and II collagen on sodium dodecyl sulfate-polyacrylamide gels has been developed and found to be accurate and very reliable. The ratio of the area under the alpha 1(II)CB10 peak to the area under the alpha 1(I)CB7,8 + alpha 1(II)CB11 peak was function of the proportion of type II collagen in the sample.

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Atherosclerosis was induced in growing chickens by the administration of a diet containing elevated levels of cholesterol and vitamin D3. The effect of this diet on the accumulation of insoluble elastin and the synthesis of soluble and insoluble elastin in the thoracic aortas of these animals was measured. Although the diet resulted in significant increases in levels of cholesterol, 25-OH vitamin D3 and calcium in plasma, increased levels of cholesterol and calcium in aortic tissue, and histological evidence of aortic lipid deposition, there were no detectable differences between experimental and control animals in either the rate or the time course of accumulation of total insoluble elastin in the thoracic aorta, or in the rate and time course of synthesis of soluble and insoluble elastin.

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Human scleral tissue contains approximately 50% collagen by weight, consisting predominantly of type I collagen. There is little or no evidence for the presence of substantial quantities of type II, type III or other collagen types. There appears to be no difference in either collagen content or genetic type in sclera between adult and juvenile tissues or between anterior and posterior segments of the sclera, although, with increased age there is a marked increase both in the extent of glycosylation of the collagen and its resistance to solubilization by treatment with pepsin.

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Light and electron microscopic observations and biochemical analysis of the lingual cartilages from the Atlantic hagfish, Myxine glutinosa, reveal two different types of cartilage, designated types 1 and 2, respectively. The anterior and medial lingual are type 1, while the posterior lingual cartilage is type 2. Chondrocytes in type 1 cartilage are similar to those found in other vertebrate cartilages.

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A sensitive, selective, and rapid high-performance liquid chromatographic procedure was developed for the determination of isoxicam in human plasma and urine. Acidified plasma or urine were extracted with toluene. Portions of the organic extract were evaporated to dryness, the residue dissolved in tetrahydrofuran (plasma) or acetonitrile (urine) and chromatographed on a mu Bondapak C18 column preceded by a 4-5 cm X 2 mm I.

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A high-performance liquid chromatographic method has been developed for the analysis of plasma and urine concentrations of a new cardiotonic agent, MDL 19,205 (I). This procedure was utilized to study the pharmacokinetics of I in beagle dogs. The results of the dog study show that the compound is completely and rapidly absorbed.

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Ten healthy male volunteers received single oral doses of 100 mg of medroxalol administered as a solution, a preliminary tablet formulation and a single dose of 100 mg administered intravenously in a randomized three-way crossover study. Mean terminal half-lives of 12.4, 13.

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The rate of in vitro synthesis of soluble and insoluble elastin by thoracic aorta of 2-day-old chicks has been measured in absolute terms. In the absence of beta-aminopropionitrile (beta APN), the steady state level of soluble elastin was 120 pmol/100 mg of aortic tissue or 3.7 micrograms/whole aorta segment.

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The nature of proteins occluded in the mineralized matrix of calcified areas of atherosclerotic human aortic tissue has been investigated. In spite of their reported presence in atherosclerotic lesions, neither plasma lipoproteins, immunoglobulin G or fibrinogen could be detected among the proteins specifically trapped in the mineralized matrix and released by decalcification. However, human serum albumin was present in the decalcifying extract in a persistent complex with a more acidic protein component.

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Antibodies raised in rabbits to tropoelastin isolated from lathyritic chick aorta were conjugated with ferritin and used to identify and locate elastin-containing elements in sections of aortic tissue from developing chicks. The ferritin-antibody conjugate was associated with a network of fine filaments with a diameter of 3-5 nm which, in the 8-10 day old chick embryo aorta, was distributed between and around small but recognizable elastic fibers. In older aortic tissue this ferritin-labelled material was seen principally in loose association with the periphery of developing elastic fibers.

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Histologic observations of elastic in periosteum have never been confirmed biochemically. Elastins were isolated, quantitated and characterized from human periosteal and pericranial tissues. Periosteum contains approximately 2.

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The automated amino acid analyzer has been used to provide a simple, rapid and accurate means of assaying the glycosaminoglycan (GAG) and collagen content, and collagen type of connective tissues. The analysis of rabbit articular cartilage using this method is reported. Cartilage slices taken from the tibial plateaus of rabbits were dried and weighed.

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A competitive protein binding assay for norethindrone was developed to measure plasma levels in human subjects. The plasma levels were considerably higher in women than in men, especially at low dose levels. The plasma levels were directly related to the dose in men; but greater variations in the plasma levels were observed in women.

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