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Biomedical subjects

M G Bond

Publications and source records attributed to M G Bond.

99 records · Page 6Linked to original sources
PubMed1978

Aortic pulse wave velocity, elasticity, and composition in a nonhuman primate model of atherosclerosis.

Aortic pulse wave velocity was determined in Macaca fascicularis monkeys fed either atherogenic or control diets for 36 months. The foot-to-foot velocity and apparent phase velocities of the second through seventh Fourier harmonics at a given diastolic pressure in the atherosclerotic monkeys were 1.5 to 2.0 times the values for the control animals. More than 80% of the aortic intimal surface of the atherosclerotic monkeys was covered with fibrous or fatty plaque, which approximately doubled wall thickness and wall thickness to radius ratio. Angiochemical evaluations showed no difference in collagen or elastin concentration (as a fraction of lipid and mineral-free dried aorta), but the atherosclerotic aortas were 1.5 to 2.0 times that of control in collagen and elastin content (defined as the absolute quantity beneath a square centimeter of intimal surface). Total cholesterol and calcium concentrations in the atherosclerotic aortas were more than 10 times the values for the control aortas. The static circumferential distensibility of the excised atherosclerotic aortas was significantly less than control, but there was no difference in incremental (Young's) modulus of elasticity. The in vitro pressure-strain elastic modulus of the atherosclerotic aortas was more than twice that of control, which was predicted from the enhanced wave velocity. The significantly increased stiffness of the atherosclerotic arteries appeared to be due mainly to the increased wall thickness caused by the atherosclerotic plaques rather than to material changes described by Young's modulus. Extensive medial damage, however, also was present and could have had a major influence on stiffness. Atherosclerosis therefore can result in increased aortic stiffening, detectable by pulse wave velocity, even if there is no change in the overall Young's modulus of elasticity.

Animals↗
PubMed1978

Bacterial endocarditis with obstruction of the right atrioventricular orifice and the pulmonary outflow trace in an African monkey (Cercopithecus aethiops).

A 7 to 8-year-old male African green monkey (Cercopithecus aethiops) was found moribund in his cage. Fluid and antibiotic therapy were administered, but the monkey dies 2 hours later. At necropsy, large septic mural thrombi obstructed the right atrioventricular orifice and the pulmonary outflow tract, and smaller septic thrombi were attached to the leaflets of the pulmonary and mitral valves. Staphylococci were isolated from the large thrombus occluding the atrioventricular orifice. Large abscesses were present in the upper and lower lobes of the right lung, and small, wedge shaped infarcts were present in the lungs and kidneys. The clinical and pathologic findings were consistent with a rapidly progressive form of bacterial endocarditis. This was the only case of vegetative bacterial endocarditis seen at this instituion in 700 necropsies of nonhuman primates.

Animals↗
PubMed1977

A Müllerian duct remnant in an aged male talapoin monkey.

A pelvic mass in an aged, male talapoin monkey, believed to be of Müllerian duct origin, is described. Histologically, the mass was composed of smooth muscle cells and glandular epithelium, although the typical uterine organization of these tissues was not observed. The remainder of the genital system was that of a normal male primate.

Animals↗
PubMed1977

Cholelithiasis in a male rhesus monkey (Macaca mulatta) fed a cholesterol-containing diet.

In this report we describe the development of cholelithiasis in a male rhesus monkey fed a cholesterol-containing diet for 24 months. This represents the only case of cholelithiasis in this species of nonhuman primate that we have observed out of a population of over 500 rhesus monkeys fed similar cholesterol-containing diets. Associated with the appearance of gallstones was the production of bile saturated with cholesterol, and the excretion of bile with an abnormal bile acid composition.

Animals↗
PubMed1976

Intimal changes in arteriovenous bypass grafts. Effects of varying the angle of implantation at the proximal anastomosis and of producing stenosis in the distal runoff artery.

Autologous arteriovenous bypass grafts were constructed between external iliac arteries in 20 mongrel dogs to determine the development of intimal fibromuscular hyperplasia. Animals received grafts at 55, 90 or 120 degree angles relative to the proximal anastomosis. Five animals with 90 degree angle grafts were also subjected to 80% stenosis in the runoff artery. All grafts showed the development of a fibromuscular tunica intima. Qualitative or quantitative intimal differences were not observed among grafts placed at 90 degree angles, 90 degree angles with runoff artery stenosis, or 120 degree angles. Grafts placed at 55 degree angles relative to the proximal anastomosis developed a consistently thicker fibromuscular layer in the tunica intima when compared to the other groups. These changes which were segmental in nature, occurred in the proximal and distal grafts and over the distal anastomosis.

Animals↗
PubMedDate not supplied

Circulating oxidized low-density lipoprotein and common carotid artery intima-media thickness in a random sample of middle-aged men.

Circulating oxidized low-density lipoprotein (oxLDL) has been suggested to play an important role in atherosclerosis development. According to previous observations, oxLDL correlates with clinically manifest coronary and carotid artery disease. We investigated the association between the oxLDL concentration measured directly in plasma and common carotid artery intima-media thickness (IMT) in a population-based, case-control study in middle-aged men from Southern Finland. oxLDL was determined in 214 men by a commercially available sandwich ELISA test (Mercodia). Carotid artery IMT was measured at 12 standardized segments by B-mode ultrasonography (at the near and far wall of the left and right common carotid arteries, bifurcations and internal carotid arteries), and the overall mean maximum IMT (MMaxIMT) was calculated. The MMaxIMT of the carotid arteries was significantly associated with circulating oxLDL (r(s) = 0.16, p = 0.018). In a stepwise multiple regression model with MMaxIMT as dependent variable and systolic blood pressure, smoking, oxLDL, HDL cholesterol and apolipoprotein B as covariates, systolic blood pressure (beta = 0.22, p < 0.001), oxLDL (beta = 0.15, p = 0.022) and smoking (beta = 0.17, p = 0.014) showed an independent association with IMT (R(2) = 0.10, p < 0.001). Our results show that oxLDL measured directly from plasma is independently associated with subclinical carotid artery atherosclerosis in middle-aged men.

Carotid Arteries↗
PubMedDate not supplied

Dietary ethanol-induced modifications in hyperlipoproteinemia and atherosclerosis in nonhuman primates (Macaca nemestrina).

Male Macaca nemestrina were studied in an experiment with a 2 x 2 factorial design. Diets contained low vs high cholesterol levels (0.3 vs 1.0 mg/Kcal) and no ethanol or ethanol, as 36% of the calories substituted isocalorically for carbohydrate. After receiving their diets for 18 months, the monkeys had blood samples drawn for lipoprotein analyses, and then were killed for evaluation of the extent of atherosclerosis. Ethanol-fed groups had significantly increased concentrations of serum cholesterol, triglycerides, low density lipoprotein, and high density lipoprotein. The molecular weight of the low density lipoprotein particles was lower in ethanol-fed animals and the cholesterol esters of low density lipoprotein and high density lipoprotein contained relatively more cholesteryl linoleate and less cholesteryl oleate. Dietary cholesterol had the effect of increasing the concentration of low density lipoprotein (primarily via increasing the low density lipoprotein molecular weight) and decreasing the concentration of high density lipoprotein. Significant interactions were found between the effects of ethanol and cholesterol on high density lipoprotein and low density lipoprotein. Ethanol significantly decreased the cholesterol-induced atherosclerosis found in the aorta and coronary arteries. Highly significant correlations between coronary artery atherosclerosis and low density lipoprotein cholesterol ester pattern were found. In contrast, low density lipoprotein molar concentration (number of low density lipoprotein particles per liter of plasma) was not significantly correlated with coronary artery atherosclerosis. Different relationships with aortic atherosclerosis were found; low density lipoprotein molecular weight and cholesterol ester pattern were highly correlated, while high density lipoprotein concentration was not. The high correlations found between lipoprotein characteristics and atherosclerosis severity have been mediated through its effects on the plasma lipoproteins.

Animals↗
PubMedDate not supplied

Measurement variability of carotid atherosclerosis: real-time (B-mode) ultrasonography and angiography.

To quantify the within- and between-reader agreement of carotid B-mode ultrasonography and angiography interpretation, images from 117 patients examined by both modalities were read multiple times. Angiographic measurements were more reproducible than those of B-mode scans for all parameters except lesion width, but variations for B-mode scan measurements were similar to those for angiographic measurements. Within-reader agreement on the presence of ulceration was substantial for both modalities, whereas between-reader agreement was poor for B-mode scan and only moderate for angiography.

Carotid Artery Diseases↗