bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection and characterization of the heterozygote state for lipoprotein lipase deficiency.
Authors: Babirak S P , Iverius P H , Fujimoto W Y , Brunzell J D
Published: June 2011

Because there are no characteristic clinical or biochemical manifestations, the heterozygote state for lipoprotein lipase (LPL) deficiency has been difficult to detect. Measurements of postheparin plasma LPL activity and of LPL mass were performed in six families of probands with LPL deficiency to characterize the heterozygote state. LPL mass was measured in a sandwich enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (5D2) that had been produced against bovine milk LPL. Thirteen obligate heterozygotes from these families had reduced LPL activity and mass below the 95th percent confidence limits of 34 normal controls, while one obligate heterozygote had LPL activity and mass between the 90th and 95th percent confidence limits. Potential heterozygotes in these families were identified as normal (n = 8) or heterozygotes (n = 6) by comparison to the 95th percent confidence limits of the controls. Some relatives in four of the six families exhibited mild hyperlipidemia, similar to the pattern seen in familial combined hyperlipidemia (FCHL). The hyperlipidemia segregated with the heterozygote state for LPL deficiency in these families (p less than 0.03). High density lipoprotein (HDL) cholesterol was significantly reduced in the heterozygotes for LPL deficiency (p less than 0.01). The measurement of LPL activity and mass allows identification of the heterozygote state for LPL deficiency, which is characterized by variable expressions of hyperlipidemia and reduced HDL cholesterol. These results suggest that the heterozygote state for LPL deficiency may form one subset of FCHL.
Heterogeneity of low density lipoprotein responses to fish-oil supplementation in hypertriglyceridemic subjects.
Authors: Schectman G , Kaul S , Kissebah A H
Published: June 2011

Previous studies have demonstrated a variable effect of fish oil on low density lipoprotein (LDL) cholesterol and apolipoprotein (apo) B levels, particularly in hypertriglyceridemic subjects. Since heterogeneity of LDL composition and metabolism in hypertriglyceridemic subjects is well described, the present study was undertaken to determine if the response of LDL to dietary fish-oil supplementation is dependent upon pretreatment differences in LDL composition. A single-blind, cross-over design was used with 18 hypertriglyceridemic subjects, who were given supplements of a safflower-oil placebo or a fish-oil concentrate (4.0 g omega-3 fatty acids; [F4 dose]) for 1 month. Sixteen subjects then received an additional month of fish-oil supplementation at a higher dose (7.5 g omega-3 fatty acids [F7.5 dose]). The initial LDL cholesterol/apo B ratio, an index of LDL composition, was correlated positively with changes in LDL apo B levels (F4.0 dose: r = 0.41, p = 0.06; F7.5 dose: r = 0.51, p = 0.03) and negatively with changes in LDL cholesterol concentrations (F4.0 dose: r = -0.51, p = 0.01; F7.5 dose: r = -0.50, p = 0.02). Twelve subjects with LDL cholesterol/apo B ratios above 1.4 had large increases in LDL apo B (51% at both doses, p less than 0.05) but much smaller changes in LDL cholesterol levels during fish-oil treatment. Six subjects with LDL cholesterol/apo B ratios below 1.4 showed a trend toward increased LDL cholesterol (12% increase from baseline at F4 dose, 10% increase from baseline at F7.5 dose, p greater than 0.05) but not in LDL apo B levels during fish-oil therapy. These data suggest that LDL responses to fish oil may be linked to underlying differences in LDL composition and, presumably, to differences in LDL metabolic behavior.
Cholesterol homeostasis in mononuclear leukocytes from patients with familial hypercholesterolemia treated with lovastatin.
Authors: Hagemenas F C , Illingworth D R
Published: June 2011

We evaluated the effects of different doses of lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA reductase) and the rate-limiting enzyme in cholesterol biosynthesis, on parameters of cholesterol homeostasis in freshly isolated mononuclear leukocytes from 19 patients with heterozygous familial hypercholesterolemia. Patients were treated with sequentially increasing doses of lovastatin (10 to 80 mg/day in a twice-daily regimen). The in vitro activity of HMG CoA reductase and cholesterol synthesis from 2-14C-acetate was determined in mononuclear cells obtained under steady-state conditions after patients had spent 6 weeks on doses of 20, 40, or 80 mg/day. The total and high affinity degradation of 125I-low density lipoprotein (LDL) was determined at baseline and on lovastatin at a dose of 80 mg/day. LDL cholesterol levels fell progressively on lovastatin (38% reduction on 80 mg daily, p less than 0.005). These changes were paralleled by a 121% increase in the activity of HMG CoA reductase (p less than 0.05) and a 39% increase in cholesterol synthesis from 2-14C-acetate (p less than 0.005). Total and high affinity degradation of 125I-LDL increased from 27 +/- 3.3 and 12.1 +/- 1.6 ng/4 x 10(6) cells/4 hours on the diet only to 69.7 +/- 7.2 and 32.9 +/- 3.6 ng/4 x 10(6) cells/4 hours, respectively, (mean +/- SEM) in mononuclear cells isolated from patients on 80 mg of lovastatin daily (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Cytodifferentiation and expression of alpha-smooth muscle actin mRNA and protein during primary culture of aortic smooth muscle cells. Correlation with cell density and proliferative state.
Authors: Campbell J H , Kocher O , Skalli O , Gabbiani G , Campbell G R
Published: June 2011

To investigate a possible correlation between cytodifferentiation, proliferation, and actin expression, smooth muscle cells from the 9-week-old rabbit aortic media were enzyme-dispersed into single cells and were plated in primary culture at different initial seeding densities. The volume fraction of myofilaments (Vv myo) in cells seeded moderately densely fell from 39.5% +/- 1.2% in the intact aortic media to 11.5% +/- 1.6% on Day 5, one day before the onset of logarithmic growth. The Vv myo remained low over the next 3 days, then began to rise as the density of cells increased, returning almost to the original levels after confluency and 1.84 cumulative population doublings (CPD). The expression of alpha-smooth muscle actin mRNA followed a similar time course of change, falling from 84.7% +/- 1.2% of total actin mRNA in freshly isolated cells to 54.0% +/- 6.5% on Day 5, returning to 87.5% +/- 0.5% after confluency. In these cultures, the alpha-smooth muscle actin protein content was 93.7% +/- 2.9% of total actin in freshly isolated cells, 68.7% +/- 3.1% on Day 5, and 73.3% +/- 2.5% 3 days after confluency. In densely seeded cultures, the Vv myo and expression of alpha-smooth muscle actin mRNA fell only slightly on Day 5 and rose to original levels upon confluency after 0.33 CPD. However, at the protein level, alpha-smooth muscle actin decreased on Day 5 and remained low on Day 12. The Vv myo, alpha-smooth muscle actin mRNA, and actin protein of sparsely seeded cells fell on Day 5 and then remained low throughout the culture period, including 5 days after confluency (Day 24), when the cells had undergone 5.37 CPD. Cells that were maintained subconfluent but quiescent on Day 7 in culture had the same low Vv myo, low alpha-actin mRNA expression, and low alpha-actin protein content as actively proliferating cells. The results show that Vv myo and alpha-smooth muscle actin mRNA undergo parallel changes during primary culture according to seeding density, but not to replication, and that alpha-smooth muscle actin protein decreases in culture then remains low irrespective of culture conditions.
Distribution of lipoproteins and apolipoproteins in young adults The CARDIA Study.
Authors: Donahue R P , Jacobs D R , Sidney S , Wagenknecht L E , Albers J J , Hulley S B
Published: June 2011

While there are many studies of the distribution of coronary heart disease risk factors in children, adolescents, and middle-aged adults, little information is available on this topic in young adults. The Coronary Artery Risk Development in Young Adults Study (CARDIA) examined 4858 men and women who fasted 10 or more hours, were ages 18 to 30, and were representative of black and white residents of four U.S. communities. Compared with white men, black men had higher age-adjusted mean levels of high density lipoprotein cholesterol (HDL-C) (6.7 mg/dl, p less than 0.001) and apolipoprotein A-l (apo A-l) (9.1 mg/dl, p less than 0.001) and lower concentrations of triglycerides (-19.7 mg/dl, p less than 0.001) and apolipoprotein B (apo B) (-3.3 mg/dl, p less than 0.001). Compared with white women, black women displayed higher concentrations of low density lipoprotein cholesterol (LDL-C) (5.7 mg/dl, p less than 0.001), apo A-l (2.6 mg/dl, p = 0.001), and apo B (3.0 mg/dl, p less than 0.001), but lower triglycerides (-5.8 mg/dl, p=0.001). Gender differences were more pronounced among whites: white men displayed lower mean levels of HDL-C and apo A-l (-9.2 and -7.3 mg/dl, p less than 0.001) and higher concentrations of LDL-C, triglycerides, and apo B (5.2 20.3, and 5.3 mg/dl, p less than 0.001) than white women. Attained level of education was significantly associated with a favorable lipoprotein/apolipoprotein profile, particularly among white women. These data indicate substantial variation in the distribution of lipoproteins and apolipoproteins in young adults, which may be important determinants of future coronary disease risk.
Complement receptors and regulatory proteins in human atherosclerotic lesions.
Authors: Seifert P S , Hansson G K
Published: June 2011

Complement activation in human atherosclerotic lesions is indicated by the presence of C5b-9 terminal complexes. By using monoclonal antibodies to the complement C3b receptor (CR1) and the iC3b receptor (CR3), it was observed that approximately 20% of the cells in complicated human carotid lesions express CR1 and CR3 antigens. One to five percent of complement receptor-positive cells stained for smooth muscle cell-specific myosin, and the remainder were determined to be predominantly macrophages, based on their reactivity to anti-LeuM3 (CD14) monoclonal antibody. No C3dg receptor (CR2)-positive cells were observed in any of the eight lesions examined. The complement regulatory glycoprotein decay accelerating factor (DAF) was widely distributed extracellularly, in addition to being present on 20% to 60% of the total cell population. Factor H, a plasma protein that regulates alternative pathway C3 convertase formation, was observed extracellularly in 70% of the lesions examined. C1 inhibitor was present in a few plaque specimens, was relatively sparse, and appeared largely cell associated. Terminal C5b-9 complement complexes were pervasive in all lesions. Both the complement regulatory proteins and the activation products were limited to the area of lesion involvement and were absent from normal arterial wall. The results demonstrate that molecules involved in complement regulation and complement ligand binding are present in atherosclerotic lesions, where they may function to modulate the activities of complement.
Effects of eicosapentaenoic and docosahexaenoic acids on apoprotein B mRNA and secretion of very low density lipoprotein in HepG2 cells.
Authors: Wong S H , Fisher E A , Marsh J B
Published: June 2011

Oleic acid (18:1n-9, OA), docosahexaenoic acid (22:6n-3, DHA), or eicosapentaenoic acid (20:5n-3, EPA) was added to HepG2 cells at a concentration of 1 mM in a 5:1 or 2:1 molar complex with bovine serum albumin (BSA), and this was incubated for 3 hours. The incorporation of 3H-glycerol into cellular and medium triglyceride (TG), and the mass of TG were measured. The effects of these fatty acids on the secretion of very low density lipoprotein (VLDL) apolipoprotein B (apo B) were estimated from the incorporation of 3H-leucine into the medium apo B in comparison to cells incubated with fatty acid-poor albumin. The secretion of human albumin by the cells was also estimated by immunochemical precipitation of the labeled albumin. In addition, the intracellular levels of apo B messenger ribonucleic acid (mRNA) were measured by the dot-blot hybridization technique. Relative to control cells incubated with BSA, OA (complexed to BSA at a 5:1 molar ratio) stimulated TG synthesis and secretion sevenfold. Compared to OA, EPA was 24% less effective for both processes, whereas DHA inhibited only the secretion of TG (-43%). The secretion of VLDL apo B was not affected by OA, but was decreased 31% by EPA and 54% by DHA. When the molar ratio of fatty acid complexed to albumin was changed to 2:1, similar results were obtained with respect to TG production. The levels of apo B mRNA relative to actin mRNA were not significantly altered by any of the fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)
Prednisone increases low density lipoprotein in cynomolgus monkeys fed saturated fat and cholesterol.
Authors: Ettinger W H , Dysko R C , Clarkson T B
Published: June 2011

Cynomolgus monkeys were given prednisone to determine its effects on lipoprotein metabolism and other risk factors for atherosclerotic cardiovascular disease. After 1 month of oral prednisone, the mean total plasma cholesterol (TPC) concentration increased from 240 +/- 36 to 476 +/- 78 mg/dl (p less than 0.01) in animals fed a diet containing 36% of calories as fat (polyunsaturated/monounsaturated/saturated, 1.0:3.9:4.1) and cholesterol (0.39 mg/kcal). The increase in TPC was due to higher concentrations of the apolipoprotein B (apo B)-containing lipoproteins, particularly low density lipoprotein (LDL). LDL cholesterol concentrations also increased in animals fed a diet containing saturated fat and 0.25 mg/kcal of cholesterol, as well as in animals fed monkey chow. Kinetic studies of LDL indicated both an increased flux of apo B into LDL and a decrease in the fractional catabolic rate of LDL. Mean high density lipoprotein cholesterol (HDL-C) concentration decreased from 48 +/- 8.2 to 14 +/- 4 mg/dl, p less than 0.001, in animals fed fat and cholesterol, but there was no significant change in HDL-C in animals fed monkey chow. Blood pressure, fasting serum glucose, and anthropometric measures did not change after 7 months of prednisone therapy. Prednisone increases LDL concentration in the cynomolgus monkey. This animal may be a good model for studying corticosteroid dyslipoproteinemia, and possibly atherosclerosis, in an immunosuppressed host.
Initiation of atherosclerotic lesions in cholesterol-fed rabbits. I. Focal increases in arterial LDL concentration precede development of fatty streak lesions.
Authors: Schwenke D C , Carew T E
Published: June 2011

We have reported that arterial low density lipoprotein (LDL) concentrations and degradation rates in normal rabbits are elevated in those aortic sites most susceptible to early atheromatous lesions resulting from cholesterol feeding. Here we asked whether the focal differences in LDL metabolism observed in normolipidemic rabbits are accentuated during the first 16 days of feeding 2% cholesterol and whether such changes occur before accumulation of significant numbers of macrophage foam cells. No lesions were grossly visible after 16 days of cholesterol feeding. Histology indicated that macrophage foam cells were sparse during this interval and were found only in lesion-prone sites at longer feeding times. We used LDL labeled both with 131I (to trace undegraded LDL), and with the intracellularly trapped ligand 125I-tyramine cellobiose (to trace degraded plus undegraded LDL). The most profound change was a marked and focal increase in the concentration of intact LDL within the arterial wall of lesion-prone sites. After 16 days of cholesterol feeding when the plasma LDL cholesterol concentration had increased 7.6-fold, the concentration of intact LDL in lesion-prone branch sites of the abdominal aorta was increased by 22-fold (from 2.5 to 54 micrograms LDL cholesterol/g). These concentrations were two and 5.7 times, respectively, as great as in the lesion-resistant, nonbranch areas of the abdominal aorta of the same animals. Similar, but less striking, results were found when the lesion-prone aortic arch and intercostal orifices of the thoracic aorta were compared with adjacent lesion-resistant sites. Arterial LDL degradation rates expressed in terms of LDL mass also increased with time of cholesterol feeding, and were greater in the aortic arch and in branch sites of the abdominal aorta than in adjacent lesion-resistant sites. However, fractional rates of degradation of arterial LDL were decreased in all sites by cholesterol feeding, and were lower in susceptible than in resistant sites. This was probably due in large part to saturation and down-regulation of LDL receptors. The timing, focal nature, and site-specificity of these changes suggest that an increased concentration of LDL in the arterial wall may be an early indication of lesion formation and, in fact, may be a necessary first step in the pathogenesis of the fatty streak lesion in cholesterol-fed rabbits.
Demonstration of lateral and epicardial border zone salvage by flurbiprofen using an in vivo method for assessing myocardium at risk.
Authors: Darsee J R , Kloner R A , Braunwald E
Published: June 2011

The purposes of this investigation were (1) to develop an in vivo method of determining the myocardium at risk after experimental coronary occlusion; (2) to define the spatial geometry of the salvageable ischemic border zone; an (3) to assess the ability of flurbiprofen, an antiinflammatory agent, to protect ischemic myocardium from necrosis. Twenty-two open-chest dogs underwent left anterior descending coronary artery occlusion and were randomized to treated (flurbiprofen 1 mg/kg i.v. at 30 minutes and 4 hours after occlusion; n = 11) or control (saline; n = 11) groups. Six hours after occlusion, methylene blue, 3 ml/lg, was injected into the left atrium, and immediately thereafter the hearts were removed and sliced transversely. Areas not perfused by methylene blue (area at risk [Ar]) were traced, planimetered, and compared to the area of necrosis (An) after incubation in triphenyltetrazolium chloride. The Ar for the two groups were similar (control 28.2 +/- 2.6%; treated 25.2 +/- 2.3% of total left ventricle; NS). In control dogs, An/Ar was 96.2 +/- 0.7%, with similar values for the epicardium and endocardium. In treated dogs, An/Ar was 66.9 +/- 8.9% (p < 0.001), with greater epicardial than endocardial salvage. Topographic superimposition of the An on the Ar showed that salvage occurred both on the epicardial and lateral aspects of the infarct. We conclude that (1) the in vivo methylene blue method of assessing myocardium at risk is useful in standardizing experimental infarct size; (2) flurbiprofen, administered 30 minutes and 4 hours after occlusion, is a potent agent for reducing infarct size; and (3) salvage of myocardium occurs both at the lateral and epicardial borders of the infarct in dogs treated with flurbiprofen.
Vascular ring due to left aortic arch and right descending aorta.
Authors: Berman W , Yabek S M , Dillon T , Neal J F , Akl B , Burstein J
Published: June 2011

Two children presented with symptoms suggestive of a vascular ring. Barium esophagrams in each case showed a posterior impression caused by a retroesophageal aortic arch. Angiographic studies defined a rare form of vascular ring resulting from an ascending left-sided aorta, a descending right-sided aorta and a right-sided ligamentum arteriosum. At surgery, the diagnosis was confirmed and the anomaly was corrected in each patient. Left pulmonary anomalies were present in each patient.
Oral prostaglandin E2 in ductus-dependent pulmonary circulation.
Authors: Silove E D , Coe J Y , Shiu M F , Brunt J D , Page A J , Singh S P , Mitchell M D
Published: June 2011

Prostaglandin E2 (PGE2) was administered orally, in doses of 12-65 microgram/kg at intervals of 1-4 hours, to 12 neonates in whom the pulmonary circulation depended on patency of the ductus arteriosus. After an oral dose, both oxygen saturation (SaO2) and plasma PGE2 concentration increased consistently within 15-30 minutes, reaching values comparable to those during i.v. infusions. Treatment continued for 5 days to 4 months. In eight infants, PGE2 withdrawal resulted in a decrease of SaO2, from a mean of 75 +/- 7% to 57 +/- 10% (+/- SD). The ductus remained responsive for long periods--in four infants, for over 3 months. Consequently, surgery could be delayed until the infants and their pulmonary arteries had grown. Side effects during oral therapy were similar to those during i.v. infusion but were less severe in this series. The effectiveness and simplicity of oral PGE2 administration have advantages over i.v. administration, especially for long-term treatment.
Significance of coronary arterial thrombus in transmural acute myocardial infarction. A study of 54 necropsy patients.
Authors: Brosius F C , Roberts W C
Published: June 2011

In 54 necropsy patients with transmural acute myocardial infarction (AMI) and coronary arterial thrombi, histologic sections of coronary arteries that contained the thrombi were examined by video-planimetry to determine if the amount of luminal narrowing caused by thrombi was comparable to that produced by underlying atherosclerotic plaques, and to determine the amount of luminal narrowing by plaques immediately proximal and distal to the thrombi. The 54 coronary arteries in the 54 patients were narrowed 33-98% (mean 81%) by atherosclerotic plaque alone in cross-sectional area at the site of the thrombus (occlusive in 47 and nonocclusive in seven), from 26-98% (mean 75%) within the 2-cm segment proximal to the thrombus, and from 43-98% (mean 79%) within the 2-cm segment distal to the thrombus. Of the 54 arteries, 52 (96%) were narrowed 76-98% in cross-sectional area by atherosclerotic plaque alone at or immediately proximal or distal to the thrombus and 26 (48%) were narrowed 91-98% by plaque alone. The thrombi were 0.1--6.0 mm2 (mean 1.4 mm2) in cross-sectional area and the underlying atherosclerotic plaques were 3.0-21.0 mm2 (mean 8.7 mm2). Thus, among necropsy patients with transmural AMI, coronary thrombi occur at sites already severely narrowed by atherosclerotic plaques.
Detection of intracranial arteriovenous fistula by two-dimensional ultrasonography.
Authors: Snider A R , Soifer S J , Silverman N H
Published: June 2011

Three newborn infants who had severe congestive heart failure caused by an arteriovenous malformation of the vein of Galen were evaluated by two-dimensional ultrasonography. Examination of the heart from standard echocardiographic planes showed right atrial and right ventricular dilatation. The superior vena cava, ascending aorta and the vessels to the head and neck were enlarged. Contrast two-dimensional echocardiography from a peripheral vein showed right-to-left atrial shunting and early superior vena cava recirculation. With the transducer positioned in the anterior fontanel or against the temporal bone, two-dimensional sector scans of the brain were obtained in the coronal, sagittal and transverse planes. A large echo-free space that represented an aneurysm of the vein of Galen was seen within the brain. During contrast injection into a peripheral vein, microcavitations that passed from right to left at the atrial level were seen filling the vein of Galen aneurysm. In two infants in whom beryllium wire was placed in the fistula to induce thrombosis, postoperative ultrasonography showed a dense mass of echoes arising from the wire and persistent left-to-right shunting through the fistula. In infants presenting in the first week of life with congestive heart failure and cyanosis of unknown etiology, two-dimensional ultrasonography provides a rapid, safe method for detecting intracranial arteriovenous malformation.
Relation between right ventricular mass and cavity size: an analysis of 1500 human hearts.
Authors: Horan L G , Flowers N C , Havelda C J
Published: June 2011

We examined data on the mass, area and myocardial abnormality (scar or infarction) of the right ventricular free wall (RVFW) from 1500 consecutive dissections of hearts that came to autopsy. There were 447 hearts with associated coronary and ischemic heart disease (CAD) and 826 without CAD. RVFW mass was used as an index of hypertrophy (RVH) and RVFW area was used as an index of dilatation (RVD). In both groups of hearts, RVH and RVD were strongly correlated and can be properly referred to as one entity: right ventricular enlargement (RVE). Right ventricular infarction occurred both with and without RVE but rarely without CAD. Right ventricular infarction usually assumed an apical or basal pattern of distribution parallel to that of the adjacent left ventricular lesion.
Two-dimensional echocardiographic identification of surgically correctable complications of acute myocardial infarction.
Authors: Mintz G S , Victor M F , Kotler M N , Parry W R , Segal B L
Published: June 2011

The appearance of a new, loud systolic murmur in a patient with congestive heart failure after an acute myocardial infarction suggests a surgically correctable cause of the heart failure. Using two-dimensional echocardiography, we studied 14 patients who presented in this manner. Four patients had rupture of a papillary muscle with a flail mitral valve. All four had surgery; three survived. Five patients had fibrosis of the posteromedial papillary muscle. All five had surgery; three survived. Five patients had a ventricular septal defect. Three of the five had surgery; one survived. Two-dimensional echocardiography is useful in studying patients with a new systolic murmur and congestive heart failure after acute myocardial infarction to detect surgically correctable structural defects.
Magnitude of dilatation of large and small coronary arteries of nitroglycerin.
Authors: Feldman R L , Pepine C J , Conti C R
Published: June 2011

Vasodilatory responses of segments of large epicardial left coronary artery (CA), small intramyocardial CAs (0.3-1.0 mm), coronary stenoses and CAs filled by collaterals were determined in 34 patients. Measurements were made before and after nitroglycerin (0.4 mg, sublingual) by means of quantitative magnification coronary angiography using photospot film and a calibrated 6-power viewing device. The left main CA, proximal, middle and distal anterior descending and circumflex segments, and small CAs showed dilatation that varied in magnitude. When magnitude of dilatation was compared with control diameter of the vessel and its location, control diameter proved to be the significant independent variable. CAs with the smallest control diameter showed the greatest magnitude of vasodilatation. CA branches filled by collaterals had vasodilatation similar in magnitude to that of CAs of comparable control diameter. Although coronary stenoses dilated, the magnitude of dilatation was less than that observed in nonstenosed arterial segments of similar control diameter. When areas of stenosis were excluded, however, results were similar regardless of whether the patient had CA disease. These data indicate that a principal determinant of the CA vasodilatory response to nitroglycerin is the size of the artery before nitroglycerin.
Atrial septal defect in patients ages 60 years or older: operative results and long-term postoperative follow-up.
Authors: John Sutton M G , Tajik A J , McGoon D C
Published: June 2011

Between 1955 and 1977, 66 patients ages 60 years or older underwent operative closure of secundum atrial septal defect. Of these, 56 (85%) were catheterized preoperatively. The 56 patients were divided into three groups to assess the effects of pulmonary hypertension on operative mortality, symptoms and longevity. The 17 group 1 patients had peak systolic pulmonary artery pressures (PAPs) of less than 40 mm Hg; the 21 group 2 patients had PAPs of 40-60 mm Hg; and the 18 group 3 patients had PAPs of more than 60 mm Hg. Among the three groups, there was no significant difference in Qp/Qs, right or left atrial pressures, right or left ventricular end-diastolic pressures and Qs, although pulmonary vascular resistance was significantly higher (p less than 0.01) in group 3 than in group 1. Four patients died, yielding an operative mortality of 6%. All four patients had undergone additional operative procedures. Operative mortality was unrelated to preoperative symptom class, PAP or pulmonary vascular resistance. Forty-seven patients were followed up for 2-20 years (mean 6.6 years), and of these, 41 (87%) improved by at least one functional class. Symptomatic benefit occurred in all groups, regardless of preoperative PAP, pulmonary vascular resistance or functional class. Actuarial survival curves showed that longevity at 5 and 10 years postoperatively was significantly increased (p less than 0.01) for patient with atrial septal defect treated surgically compared with that predicted for age-matched patients treated medically.
Accuracy of an ultrasound Doppler servo method for noninvasive determination of instantaneous and mean arterial blood pressure.
Authors: Aaslid R , Brubakk A O
Published: June 2011

A new noninvasive method for determining arterial blood pressure is presented. Using a fast servo system, the pressure in the arm cuff is controlled so that the flow is maintained at a low value. Transcutaneous ultrasound Doppler techniques are used to detect flow to the artery. Comparison with invasive pressure measurements demonstrated that the servo method reproduced beat-to-beat variations in arterial blood pressure faithfully. Mean arterial blood pressure was determined from the noninvasive recordings using the same mathematically valid procedure as was used for the invasive recordings. The deviation between the invasive and the noninvasive determinations of this measurement was -0.6 +/- 2.2 mm Hg (mean +/- SD) in 23 subjects.
The relationship of cardiac output and arterial pressure control.
Authors: Guyton A C
Published: June 2011

Many basic concepts of cardiac output and arterial pressure control have changed considerably in the past few years. In general, each tissue controls its own local resistance and blood flow regardless of the level of arterial pressure; the sum of the local flows then determines the venous return and cardiac output. However, the arterial pressure is normally controlled by separate mechanisms that do not significantly alter the cardiac output. During acute circulatory stresses, such as exercise, the arterial pressure is controlled almost entirely by nervous reflex mechanisms; but over long periods, there reflex mechanisms fade away because they adapt. The arterial pressure is then controlled mainly by a renal-volume-endocrine pressure control system, in which the blood volume and total peripheral resistance are manipulated slowly to adjust the pressure.
Association of asynchronous protodiastolic segmental wall motion with impaired left ventricular relaxation.
Authors: Ludbrook P A , Byrne J D , Tiefenbrunn A J
Published: June 2011

To determine if asynchronous segmental relaxation is associated with altered left ventricular (LV) diastolic function, we examined systolic and diastolic wall motion and function indexes in 16 patients without and 16 with asynchronous relaxation (groups 1 and 2, respectively). The segment with asynchronous relaxation was observed most frequently in the free anterior LV wall and was not consistently related geographically to coronary stenosis, nor to systolic asynergy in the same region, but was frequently accompanied by simultaneous segmental inward motion elsewhere in the ventricle. LV chamber volume stiffness during diastolic filling and at end-diastole was statistically similar in each group. Conversely, both T (58.3 +/- 2.3 msec vs 41.0 +/- 3.6 msec) and the isovolumic relaxation period (140.9 +/- 7.5 msec vs 116 +/- 6 msec) were significantly more prolonged, peak negative dP/dt was lower (1314 +/- 57 mm Hg/sec vs 1604 +/- 114 mm Hg/sec), and the y-axis intercept of the diastolic pressure-volume curve was higher in group 2 patients (7.96 +/- 0.98 mm Hg vs 4.88 +/- 0.93 mm Hg) (p less than 0.05 for each), indicating impaired relaxation and altered diastolic tone. With improved systolic function and relaxation properties after nitroglycerin, both the asynchronous outward relaxation and the inferior segment of simultaneous inward motion were ameliorated. Conversely, with increased ventricular preload and afterload induced by isometric exercise, both the asynchronous segmental outward motion anteriorly and the inward motion inferiorly with exaggerated. Asynchronous segmental relaxation may represent a compensatory mechanism in areas of normal contraction that offsets abnormal inward motion elsewhere, tending to maintain isovolumic status of the ventricle.
Evaluation of combined valvular prolapse syndrome by two-dimensional echocardiography.
Authors: Ogawa S , Hayashi J , Sasaki H , Tani M , Akaishi M , Mitamura H , Sano M , Hoshino T , Handa S , Nakamura Y
Published: June 2011

The patterns of aortic and tricuspid valve motion in 50 patients with mitral valve prolapse were analyzed by wide-angle, phased-array, two-dimensional echocardiography. Twelve patients (24%) had redundant aortic leaflets bulging into the left ventricular outflow tract during diastole. Eight of 12 patients had aortic regurgitation and seven of 12 had M-mode echocardiographic evidence of aortic valve prolapse. One patient underwent mitral and aortic valve replacement, and the excised valves revealed marked myxomatous degeneration. Eight of 15 patients undergoing contrast echocardiography had tricuspid regurgitation (systolic reflux of contrast material into the inferior vena cava persisting for more than 10 beats), and prolapse in the septal leaflet of the anterior leaflet or both. A similar tricuspid valve pattern was noted in three of seven patients without tricuspid regurgitation. Tricuspid valve prolapse was identified in 20 patients (40%). Nine patients (18%) had combined prolapse of the mitral, aortic and tricuspid valves. In five patients with middiastolic high-pitched murmurs recorded along the left sternal border, tricuspid valve prolapse was demonstrated. In one of these patients, the presence of pulmonary regurgitation was confirmed by intracardiac phonocardiography. We conclude that two-dimensional echocardiography is useful for evaluating patients with combined valvular prolapse syndrome.
Process versus outcome in hypertension: a positive result.
Authors: Haynes R B , Gibson E S , Taylor D W , Bernholz C D , Sackett D L
Published: June 2011

We studied the association between the outcome of antihypertensive care and three items of that care among 230 hypertensive steelworkers who were referred to 83 physicians. The first item was the decision to treat some patients but not others: 63% of the patients were prescribed antihypertensive drugs and the mean decrease in their diastolic blood pressure (DBP) was greater than that among untreated patients (12.2 +/- 0.84 vs 7.8 +/- 0.83 mm Hg [+/- SEM], p less than 0.001). The second item was the vigor of prescribed medication: Patients prescribed more vigorous treatments had lower DBP (p less than 0.005). Third, patient compliance was related to achieving a goal DBP of less than 90 mm Hg (p less than 0.05) and the product of prescribed vigor and compliance was highly associated with DBP response (p less than 0.0001). These results stand in contrast to those of previous studies that failed to detect associations between various other items of the care process and the outcome of antihypertensive care.
Determinants of myocardial hemorrhage after coronary reperfusion in the anesthetized dog.
Authors: Higginson L A , White F , Heggtveit H A , Sanders T M , Bloor C M , Covell J W
Published: June 2011

Intramyocardial hemorrhage often occurs with reperfusion in experimental acute myocardial infarction and is thought to be associated with extension of necrosis. To determine if hemorrhage was associated with extension of necrosis, 20 anesthetized dogs were reperfused after 6 hours of circumflex coronary artery occlusion and 10 others had control occlusion with no reperfusion. Fifteen of the 20 reperfused dogs had gross hemorrhage and none of the control dogs did. In 12 reperfused and 10 control dogs, radioactive microspheres were injected after coronary occlusion to quantitate collateral flow and in the reperfusion group microspheres were injected to quantitative reflow. Complete flow data were available in eight reperfused and 10 control dogs. Twenty-four hours after coronary occlusion, 1-g segments of infarct and control regions were analyzed for hemorrhage, collateral flow and creatine kinase activity. Serial microscopic examination was performed in eight additional dogs reperfused after 6 hours to determine if hemorrhage occurs into otherwise microscopically normal myocardium. Pathologic examination indicated that hemorrhage did not occur into otherwise microscopically normal myocardium. In dogs with hemorrhage, the extent of hemorrhage was inversely related to myocardial creatine kinase concentration and collateral flow. Mean collateral flow in 47 hemorrhagic segments was 4.5 ml/100 g (4.2% of control). Mean creatine kinase in 36 hemorrhagic segments was 233 mIU/g (21% of control). No hemorrhage was found in areas with collateral flow more than 21% of control or creatine kinase more than 37% of control. Mean reflow in hemorrhagic segments was 78.5% of control flow. These studies indicate that hemorrhage on reperfusion is associated with severe myocardial necrosis and markedly depressed flow before reperfusion and thus occurs only into myocardium already markedly compromised at the time of reperfusion. There is no evidence for hemorrhage into areas that had normal or even moderately depressed flows before reperfusion.
Determinants of arrhythmic death due to coronary spasm: effect of preexisting coronary artery stenosis on the incidence of reperfusion arrhythmia.
Authors: Sheehan F H , Epstein S E
Published: June 2011

Coronary spasm can occur in the presence or absence of coronary artery disease. We therefore determined the effect of preexisting coronary stenosis on the incidence of ventricular fibrillation during reperfusion after circumflex artery (CFX) occlusion. Twenty dogs underwent a 30-minute open-chest CFX occlusion. During reperfusion, CFX blood flow was restricted by a partial occluder. In dogs that survived reperfusion, peak CFX flow was 91 +/- 44% of baseline (mean +/- SD) compared with 163 +/- 68% in dogs that died of ventricular fibrillation (p less than 0.02). In another 17 dogs, the left anterior descending coronary artery was gradually occluded by an ameroid constrictor. After 17-39 days, the CFX was acutely occluded for 30 minutes and then reperfused. Collateral flow to the CFX, measured by microspheres, was 27.6 +/- 28.3 ml/min . 100 g-1 in dogs that died of reperfusion ventricular fibrillation, compared with 64.4 +/- 27.2 ml/min . 100 g-1 in surviving dogs (p less than 0.02). Thus, the risk of reperfusion ventricular fibrillation is greater in dogs with normal coronary arteries than in dogs with a flow-limiting partial stenosis of the artery undergoing transient occlusion, or chronic stenosis of a second coronary artery inducing collateralization to the artery subsequently undergoing transient occlusion. These results suggest that the risk of ventricular fibrillation during release of coronary spasm may be greater in patients without than in those with coronary artery disease.
Exacerbation of vasotonic angina pectoris by propranolol.
Authors: Robertson R M , Wood A J , Vaughn W K , Robertson D
Published: June 2011

Using a double-blind protocol, we investigated the use of propranolol in patients with coronary artery spasm as assessed by subjective and objective variables. Both low-dose (40 mg every 6 hours) and high-dose (160 mg every 6 hours) propranolol were administered. At both doses, the duration of angina attacks was significantly prolonged but the frequency was not. We conclude that propranolol at doses up to 160 mg every 6 hours as single therapy is frequently detrimental in angina pectoris due to coronary artery spasm and should not be used as the sole treatment of this disorder.
Relationship of blood pressure in 20-39-year-old men to subsequent blood pressure and incidence of hypertension over a 30-year observation period.
Authors: Rabkin S W , Mathewson F A , Tate R B
Published: June 2011

The objective of this investigation was to determine the relationship of blood pressure (BP) in young men, ages 20-39 years, to their subsequent BP from the perspective of BP tracking, position in BP distribution and later evidence of hypertensive BP values. Since 1948, the Manitoba Study group has followed 3983 men, 90% of whom were 20-39 years old at entry. BP in persons not prescribed antihypertensive medications was examined at 5-year intervals during the 30-year observation period to 1978. To adjust for age, BP was examined within 5-year age groups at entry. The correlations between entry and subsequent BP at the same length of follow-up were greater for systolic than diastolic BP and increased with older ages. The correlation decreased wtih every 5-year examination after entry for all ages. Men whose BP was below the mean at entry were less likely to have a BP greater than 1 standard deviation (SD) above the mean at any of the examinations. Men with an entry BP greater than 1 SD above the mean were more likely to have BP greater than 1 SD above the mean later, but the relationship decreased considerably after 20 years, especially in 20-24-year age group. The results were similar for the probability of hypertension values (systolic BP greater than or equal to 140 or 150 mm Hg, diastolic BP greater than or equal to 90 or 95 mm Hg) at later examinations. Thus, BP in later life can be predicted from BP at ages 20-39 years and can identify groups at high or low risk for hypertension.
Noninvasive visualization of the dilated main coronary arteries in coronary artery fistulas by cross-sectional echocardiography.
Authors: Yoshikawa J , Katao H , Yanagihara K , Takagi Y , Okumachi F , Yoshida K , Tomita Y , Fukaya T , Baba K
Published: June 2011

Real-time cross-sectional echocardiographic studies of the main coronary arteries were performed in 20 normal subjects, 12 patients with patent ductus arteriosus and 14 patients with coronary artery fistula in whom the diagnosis was established by angiography. In 12 patients, the coronary artery that formed the fistula was dilated: The right coronary artery was involved in eight and the left coronary artery in four. The dilated coronary artery appeared as two dominant parallel echoes of wide lumen originating from the aorta in the region of the involved artery. Th echo diameter of the coronary artery correlated well with the angiographically estimated diameter of the artery. In the normal subjects and the patients with patent ductus arteriosus, we found no echocardiographic findings of coronary artery dilatation. This study demonstrates that cross-sectional echocardiography is useful in identifying the dilated coronary artery in coronary artery fistula and distinguishing this entity from patent ductus arteriosus.
Lasting improvement of renovascular hypertension by transluminal dilatation of atherosclerotic and nonatherosclerotic renal artery stenoses. A follow-up study.
Authors: Mahler F , Probst P , Haertel M , Weidmann P , Krneta A
Published: June 2011

Sixteen consecutive patients with renovascular hypertension were treated by transluminal dilatation and observed during 6 - 39 months (mean 21.8 months). Poststenotic renal artery pressure increased (p less than 0.001) and the renal arteries were patent on angiograms taken immediately after dilatation. In 13 patients, angiography was repeated 2 - 9 months later; at that time the selective renal vein renin ratio had decreased (p less than 0.001). At the end of the follow-up, blood pressure was improved or normal in 14 cases. One of the eight patients with atherosclerosis was normotensive without treatment, compared with five of six patients with fibromuscular dysplasia (p less than 0.05). The results in two cases with vasculitis are uncertain. The four patients with relapses, one after intimal catheter dissection, were treated successfully by redilatation. Thus, renovascular hypertension can be improved by transluminal dilatation in patients with atherosclerosis and in patients with fibromuscular dysplasia with lasting success and a low morbidity rate.
Effect of hydralazine on aortic rupture induced by B-aminopropionitrile in turkeys.
Authors: Simpson C F , Taylor W J
Published: June 2011

The effects of hydralazine on aortic rupture, hemodynamics and aortic ultrastructure were studied in turkeys fed B-aminopropionitrile (BAPN). A mortality rate of 24% due to hemopericardium and internal hemorrhage in turkeys fed only BAPN increased to 91% when turkeys were fed both BAPN and hydralazine, despite a significant reduction in blood pressure after both drugs. Death rates among turkeys fed BAPN and hydralazine were lowered by adding either dietary propranolol (53%), which lowered blood pressure and dP/dt max, or reserpine (67%), which reduced blood pressure and increased dP/dt max. Striking ultrastructural alterations of collagenous and elastic fibers of the aortic media, which were additive to the effects of BAPN alone, were induced by BAPN and hydralazine. This study demonstrates that a 6-week feeding of high levels of BAPN and hydralazine, which accumulates in vessel walls, can produce vascular injury and increase mortality from hemorrhage in lathyritic turkeys.
Pathophysiology of chest pain in patients with cardiomyopathies and normal coronary arteries.
Authors: Pasternac A , Noble J , Streulens Y , Elie R , Henschke C , Bourassa M G
Published: June 2011

To clarify the pathogenesis of chest pain in patients with cardiomyopathies, we compared coronary blood flow and other indicators of ischemia at rest and during pacing-induced tachycardia in nine patients with cardiomyopathy (four hypertrophic and five congestive) and in five control subjects. Coronary blood flow was reduced at rest and during pacing in cardiomyopathy patients compared with controls. In patients with hypertrophic cardiomyopathy, pacing induced chest pain in all, increased ST-segment depression in three patients and increased coronary venous lactate concentration. With pacing, two of five patients with congestive cardiomyopathy had chest discomfort and three had increased ST-segment depression, but coronary venous lactate concentration did not change significantly. In both groups of cardiomyopathies, the ratio of the systolic and diastolic pressure-time indexes tended to decrease more than in controls during pacing. Thus, myocardial perfusion is decreased in patients with cardiomyopathy, both at rest and during pacing. The changes detected during pacing point to subendocardial ischemia as the likely mechanism for angina in hypertrophic and possibly also in congestive cardiomyopathy.
Pulmonary atresia with intact ventricular septum and ventriculocoronary communications: surgical significance.
Authors: O'Connor W N , Cottrill C M , Johnson G L , Noonan J A , Todd E P
Published: June 2011

The first stage of a repair of pulmonary atresia with intact ventricular septum (type I) was attempted in a 2-day-old infant. At surgery, decompression of the hypertensive small right ventricle was followed by a sudden loss of myocardial contractility and death. Postmortem examination revealed a fistula with a large orifice in the right ventricular infundibulum that communicated directly with the left main coronary artery. Severe hypertensive changes indicative of abnormally high perfusion pressure were noted in the distal left coronary artery branches. The clinical course suggests that the effect of relieving right ventricular outflow obstruction was a reduction of left main coronary artery blood flow, resulting in fatal intraoperative myocardial ischemia. This unusual case draws attention to the anomalous ventriculocoronary communications often present in pulmonary atresia and their potential for limiting a successful surgical repair.