Dealloying and electroformation in high-Pd dental alloys

OBJECTIVE

The corrosion of high-Pd dental alloys, depending on their composition, is postulated to be associated with dealloying and electroformation. The aim of this study was to obtain additional information to support these postulations.

METHODS

The corrosion characteristics of two commercial high-Pd alloys, Naturelle (79Pd-10Cu-2Au-9Ga wt%) and Rx 91 (54Pd-37Ag-9Sn), and their elemental components were evaluated in a phosphated buffer saline (PBS) solution. Indium, a common element in high-Pd alloys, was also included. The corrosion characteristics measured for each material were the 24 h open circuit potential (OCP) and the potentiodynamic anodic polarization curve. Additionally, the surface composition of the two alloys, before and after immersion corrosion in PBS for 2 months, was analyzed by X-ray photo electron spectroscopy (XPS).

RESULTS

Of the pure metals, Ga had the most electroactive OCP followed in order by In, Sn, Cu, Ag, Au, and Pd. The anodic polarization data showed all base metals to be unstable in PBS. The electroformation of AgCl was evidenced in the polarization curve of pure Ag. Both electrochemical characteristics of the PdCu-based alloy were very similar to that of pure Pd. The PdAg-based alloy displayed corrosion behavior resembling that of Ag. XPS data showed that the corrosion of the PdCu-based alloy was associated with a decrease in surface content of Cu and Ga but an increase in Pd and Au. The PdAg-based alloy surface during corrosion showed a decrease in Sn, an increase in Ag, and an unaltered Pd content. The behavior of the PdCu-based alloy is attributed to the operation of a galvanic interaction that causes dissolution of base metals and surface enrichment with primarily Pd. Dealloying, Ag-enrichment, and AgCl formation are thought to have contributed to the observed behavior of the PdAg-based alloy. These mechanisms are consistent with data from published ion release studies.

SIGNIFICANCE

The allergenic potential of any Pd alloy is dependent on its propensity to develop a Pd-rich surface and thus release Pd+2 ions. The present study, though limited, has shown that electrochemical characteristics, namely OCP and polarization curves, can be used to identify such alloys. Further studies are warranted to evaluate the widespread applicability of these characteristics in distinguishing between Pd alloys that are biologically safe and those that are not.

Retinopathy progression and visual outcomes after phacoemulsification in patients with diabetes mellitus

OBJECTIVES

To determine the rate of progression of diabetic retinopathy after phacoemulsification surgery, and whether surgeon experience and/or surgical duration adversely affect visual outcome.

METHODS

A retrospective review of 150 eyes of 119 diabetic patients who underwent phacoemulsification surgery during a 5-year period was performed. Data collected included patient age, sex, type and duration of diabetes, diabetic control, associated systemic health factors, preoperative visual acuity and retinopathy grade, duration of surgery, intraoperative complications, and postoperative course. The effect of these factors on visual outcome and rate of retinopathy progression was studied by means of univariate and stepwise multivariate logistic regression analyses. Resident and private cases were compared.

RESULTS

Visual acuity improved by 2 or more lines in 117 eyes (78%); 93 eyes (62%) had a final visual acuity of at least 20/40. Retinopathy progression was seen in 37 eyes (25%) with 6 to 10 months of follow-up. Preoperative nonproliferative diabetic retinopathy, proliferative diabetic retinopathy, and limited surgical experience were statistically associated with retinopathy progression and poor visual outcome.

CONCLUSIONS

The visual results and rate of retinopathy progression after phacoemulsification surgery in our series did not differ significantly from those reported that used other techniques. Nonproliferative and proliferative diabetic retinopathy and surgical inexperience resulted in an increased rate of retinopathy progression. Arch Ophthalmol. 2000;118:912-917

Insertion-deletion polymorphism of the ACE gene modulates reversibility of endothelial dysfunction with ACE inhibition

BACKGROUND

The aim of this study was to examine whether angiotensin-converting enzyme (ACE) inhibition improves coronary endothelial dysfunction in patients with atherosclerosis and its risk factors and whether this was related to the ACE insertion-deletion (I/D) polymorphism.

METHODS AND RESULTS

In 56 patients with atherosclerosis or its risk factors, we studied endothelium-dependent responses with acetylcholine and endothelium-independent function with sodium nitroprusside, before and after ACE inhibition with enalaprilat. Enalaprilat did not alter either resting coronary tone or vasodilation with sodium nitroprusside. However, it potentiated the coronary microvascular and epicardial responses with acetylcholine; coronary blood flow increased from 82+/-7 to 90+/-8 mL/min (P=0.05) after enalaprilat. Patients with depressed endothelial function (P<0.001) and those with ACE DD or ID genotypes (P=0.002) but not those homozygous for the I allele had the greatest improvement by multivariate analysis. Similarly, acetylcholine-mediated epicardial vasomotion improved in segments that initially constricted (endothelial dysfunction): from -10.1+/-1% to -1.4+/-2% (P<0.001) after enalaprilat. No augmentation was observed in segments that dilated (normal endothelial dysfunction) with acetylcholine. Patients with the D allele, hypercholesterolemia, and smokers (all P<0.05) had greater improvement.

CONCLUSIONS

Acute ACE inhibition improves coronary epicardial and microvascular endothelium-dependent vasomotion in patients with atherosclerosis or its risk factors who have endothelial dysfunction and presence of the D allele.

Sclerosing hemangioma of the lung

An extremely rare case of sclerosing hemangioma lung is described in a patient who presented as right sided pleural effusion with recurrence.

Embryonic striatal neurons from niemann-pick type C mice exhibit defects in cholesterol metabolism and neurotrophin responsiveness

Niemann-Pick type C (NP-C) disease is a progressive and fatal neuropathological disorder previously characterized by abnormal cholesterol metabolism in peripheral tissues. Although a defective gene has been identified in both humans and the npc(nih) mouse model of NP-C disease, how this leads to abnormal neuronal function is unclear. Here we show that whereas embryonic striatal neurons from npc(nih) mice can take up low density lipoprotein-derived cholesterol, its subsequent hydrolysis and esterification are significantly reduced. Given the importance of cholesterol to a variety of signal transduction mechanisms, we assessed the effect of this abnormality on the ability of these neurons to respond to brain-derived neurotrophic factor (BDNF). In contrast to its effects on wild type neurons, BDNF failed to induce autophosphorylation of the TrkB receptor and to increase neurite outgrowth in npc(nih) neurons, despite expression of TrkB on the cell surface. The results suggest that abnormal cholesterol metabolism occurs in neurons in the brain during NP-C disease, even at embryonic stages of development prior to the onset of phenotypic symptoms. Moreover, this defect is associated with a lack of TrkB function and BDNF responsiveness, which may contribute to the loss of neuronal function observed in NP-C disease.

Acute and chronic angiotensin-1 receptor antagonism reverses endothelial dysfunction in atherosclerosis

BACKGROUND

The renin-angiotensin system may contribute to atherogenesis through the promotion of endothelial dysfunction. The present study was performed to determine whether angiotensin-1 (AT(1)) receptor inhibition improves endothelial dysfunction.

METHODS AND RESULTS

In the femoral circulation of 19 patients with atherosclerosis and of 9 control subjects, we studied microvascular responses to reactive hyperemia, angiotensin II, acetylcholine, and sodium nitroprusside before and after the administration of intra-arterial losartan (10 mg). Femoral artery flow velocity was measured with a Doppler flow wire, and the femoral vascular resistance index (FVRI) was calculated as mean arterial pressure divided by flow velocity. Losartan induced a minor (5.9+/-2%, P=0. 02) reduction in FVRI and inhibited angiotensin II-mediated vasoconstriction in both patient groups (P<0.01). After the administration of losartan, acetylcholine-mediated vasodilation was augmented in patients (44+/-5% to 58+/-4% reduction in FVRI with infusion at a rate of 150 microgram/min, P<0.001) but not control subjects. Vasodilation during reactive hyperemia was also greater after AT(1) receptor inhibition (P=0.03) in patients, but the response to sodium nitroprusside remained unchanged. In a separate group of 31 patients with atherosclerosis, we investigated the effect of 8 weeks of oral losartan therapy on brachial artery flow-mediated vasodilation with the use of high-resolution ultrasound. Oral losartan therapy improved flow-mediated brachial artery dilation (1.4+/-0.9% to 3.2+/-0.8%, P=0.03) but had no effect on the nitroglycerin response. Serum nitrogen oxide levels increased from 21.6+/-1.7 to 26.7+/-2.4 micromol/L (P=0.008).

CONCLUSIONS

The results of the present study indicate that inhibition of the AT(1) receptor in patients with atherosclerosis reverses endothelial dysfunction by improving NO availability and therefore may have long-term therapeutic benefits.

Assessment of different methods for staining Helicobacter pylori in endoscopic gastric biopsies

The recent implication of Helicobacter pylori in the pathogenesis of gastritis-peptic ulcer syndrome and its relevance for the development of upper gastrointestinal malignancy warrant efficient methods for the detection and demonstration of the organism in biopsy specimens. We have compared 5 staining methods, namely, haematoxylin and eosin (H & E), immunohistochemistry (IHC), the silver staining HpSS, the alcian yellow-toluidine blue (Leung) method (A-Y) and Genta staining, for the demonstration of the organism in gastric biopsies taken from antrum, body and fundus of 118 patients who presented to our hospital with upper gastrointestinal symptoms. We found no significant differences in the efficacy of H & E, IHC, HpSS and A-Y in the demonstration of H. pylori in all 3 gastric sites. The least reproducible stain in our hands was the Genta stain. We conclude that H & E is adequate for the initial assessment of gastric biopsies in symptomatic upper gastrointestinal patients. This is because it is a well-tested, cheap and easy staining method, requiring a relatively short period of time to perform, with highly reproducible results. It has an added advantage of enabling simultaneous assessment of morphological changes accompanying H. pylori infection. When the density of the organism is expected to be low, we recommend addition of HpSS staining because of its high sensitivity and low cost. The disadvantages of the other staining methods (IHC, A-Y and Genta) are discussed.

Intermittency transitions to strange nonchaotic attractors in a quasiperiodically driven duffing oscillator

Different mechanisms for the creation of strange nonchaotic attractors (SNAs) are studied in a two-frequency parametrically driven Duffing oscillator. We focus on intermittency transitions in particular, and show that SNAs in this system are created through quasiperiodic saddle-node bifurcations (type-I intermittency) as well as through a quasiperiodic subharmonic bifurcation (type-III intermittency). The intermittent attractors are characterized via a number of Lyapunov measures including the behavior of the largest nontrivial Lyapunov exponent and its variance, as well as through distributions of finite-time Lyapunov exponents. These attractors are ubiquitous in quasiperiodically driven systems; the regions of occurrence of various SNAs are identified in a phase diagram of the Duffing system.

Modern adjunctive pharmacotherapy of myocardial infarction

During acute myocardial infarction (MI), aspirin, beta-adrenergic antagonists and oral angiotensin converting enzyme (ACE) inhibitors should be used as an adjunct to reperfusion therapy. Medications upon discharge from the hospital should include aspirin and a beta-blocker. An ACE inhibitor should also be prescribed unless the ejection fraction is > 45%. Particular indications for an ACE inhibitor are an anterior MI, congestive heart failure, ejection fraction < 45% and mitral regurgitation. beta-blockers, when given to patients treated with ACE inhibitors, appear to produce an additional benefit compared with an ACE inhibitor alone. Based on the Scandinavian Simvastatin Survival Study (4S), Cholesterol and Recurrent Events (CARE) and Long-Term Intervention with Pravastatin in Ischemic Disease (LIPID) trials, a statin should also be given to subjects with low density lipoprotein (LDL)-cholesterol levels above 125 mg/dl, independent of total cholesterol levels. Therapy should be administered in an attempt to reduce the LDL-cholesterol level to 90-100 mg/dl (2.3-2.6 mM/l). In patients with normal or low levels on initial evaluation, screening for lipid abnormalities should be deferred for 2 months since acute phase responses and passive hepatic congestion can cause spuriously normal levels. Calcium channel blockers, nitrates, lidocaine, anti-arrhythmic drugs and i.v. magnesium should not be administered routinely after acute MI and their use should be restricted to selected settings.

Chest physiotherapy compared to no chest physiotherapy for cystic fibrosis

BACKGROUND

Chest physiotherapy is widely used in patients with cystic fibrosis in order to clear mucus from the airways.

OBJECTIVES

To determine the effectiveness and acceptability of chest physiotherapy compared to no treatment or spontaneous cough alone to improve mucus clearance in cystic fibrosis.

SEARCH STRATEGY

Relevant trials are identified in the Cochrane Cystic Fibrosis and Genetic Disorders Group Specialised Register of Controlled Trials. This register was compiled by conducting computerised searches of Medline from 1966 to present and from Embase from 1974 to 1995. The register of randomised controlled trials is updated every three months. Unpublished work has been identified by searching through the abstract books of the three major cystic fibrosis conferences; the International Cystic Fibrosis Conference: the European Cystic Fibrosis Conference and the North American Cystic Fibrosis Conference. Date of the most recent search of the Group's specialised register: November 1999.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials in which a form of chest physiotherapy (airway clearance technique) were taken for consideration in patients with cystic fibrosis compared with either no physiotherapy treatment or spontaneous cough alone.

DATA COLLECTION AND ANALYSIS

There were no randomised controlled trials or cross over trials eligible for inclusion in the review.

MAIN RESULTS

There were no randomised controlled trials or cross over trials eligible for inclusion in the review.

REVIEWER'S CONCLUSIONS

Short-term crossover trials, which had to be excluded from this review, suggest that airway clearance regimens could have beneficial effects in patients with cystic fibrosis. However based on this review there is currently no robust scientific evidence to support the hypothesis that chest physiotherapy for the purpose of clearing airway secretions has a beneficial effect in patients with cystic fibrosis.

Dehydroepiandrosterone-mediated decrease in caloric intake by obese Zucker rats is not due to changes in serum entrostatin-like immunoreactivity

To understand the mechanism(s) of appetite modulation by DHEA, we have undertaken a series of studies to examine the effects of DHEA on neurotransmitters and neuropeptides known to affect appetitive behavior. Here, we report the effect of DHEA on serum enterostatin-VPDPR or E, a pentapeptide known to cause selective diminution in fat intake. Four-week-old lean (fa/+) and obese (fa/fa) Zucker rats were divided into control and treatment groups. DHEA-treated groups received powdered chow containing 0.6% DHEA ad lib for 16 weeks. Another group of obese rats was pair fed to match the intake of the obese DHEA-treated rats. At the end of this period, trunk blood was collected from fasted rats for assay of E-like immunoreactivity (E-LI) by ELISA. DHEA treatment caused a significant diminution in circulating E-LI in both lean (control: 2030 +/- 226; treated: 752 +/- 145 ng/mL; n = 10, p < 0.0001) and obese (control: 2489 +/- 391, n = 6; treated: 1123 +/- 185 ng/mL, n = 7; p = 0.0003) rats. Because DHEA treatment decreases caloric intake and body weight, we examined the effect of caloric intake and body weight on E-LI levels. Serum ELI levels were lower in the obese DHEA-treated group compared to that of obese pair fed (pair fed: 1589 +/- 313, n = 6; DHEA: 1123 +/- 185 ng/mL, n = 7), but the differences were statistically insignificant (p = 0.185). Also, both weight-matched lean and obese control rats had significantly (p < 0.008) higher E-LI than their DHEA-treated counterparts. To examine whether the decrease in serum E-LI following DHEA treatment could be due to increased peptide metabolism, the rate of disappearance of endogenous E-LI from serum (obese control and DHEA-treated) at 37 degrees C was evaluated. The results show an attenuation of peptide metabolism in serum from DHEA-treated rats, a finding contrary to our expectations. In summary, DHEA treatment lowers serum E-LI levels both in lean and obese Zucker rats. This decrement in peptide level is not secondary to changes in body weight or caloric intake due to DHEA, or due to altered serum peptide metabolism. Although DHEA appears to be a potent modulator of E-LI levels, the relationship between DHEA and E-LI in relation to appetitive behavior remains to be clarified.

Heparin-induced thrombocytopenia and thrombosis

Heparin remains the most commonly used parenteral medication in hospitalized patients. Heparin induced thrombocytopenia (HIT) and heparin induced thrombocytopenia with thrombosis syndrome or the white clot syndrome are important complications of heparin use. This article provides an in-depth review of the etiopathogenesis, clinical manifestations, diagnosis, and management options in patients with HIT. Clinical problems associated with HIT such as antiphospholipid antibody syndrome and venous gangrene are described. The management options of HIT patients during cardiac interventional procedures and coronary surgery as well as recent advances in therapeutic options are summarized.

Pili bigeminy induced by low fluence therapy with hair removal alexandrite and ruby lasers

BACKGROUND

Lasers are being widely used for the hair removal. Several complications including hyperpigmentation, erythma, hypopigmentation, and burns have been reported.

OBJECTIVE

To study laser hair removal complications.

METHODS

Pubic hairs were treated with alexandrite and ruby lasers.

RESULTS

Pili Bigeminy can be induced by low fluence therapy with hair removal Alexandrite and Ruby lasers as a complication.

CONCLUSION

To our knowledge, this is the first report of pili bigminy as a complication of laser-assisted hair removal.

Induction of Purkinje fiber differentiation by coronary arterialization

A synchronized heart beat is controlled by pacemaking impulses conducted through Purkinje fibers. In chicks, these impulse-conducting cells are recruited during embryogenesis from myocytes in direct association with developing coronary arteries. In culture, the vascular cytokine endothelin converts embryonic myocytes to Purkinje cells, implying that selection of conduction phenotype may be mediated by an instructive cue from arteries. To investigate this hypothesis, coronary arterial development in the chicken embryo was either inhibited by neural crest ablation or activated by ectopic expression of fibroblast growth factor (FGF). Ablation of cardiac neural crest resulted in approximately 70% reductions (P < 0.01) in the density of intramural coronary arteries and associated Purkinje fibers. Activation of coronary arterial branching was induced by retrovirus-mediated overexpression of FGF. At sites of FGF-induced hypervascularization, ectopic Purkinje fibers differentiated adjacent to newly induced coronary arteries. Our data indicate the necessity and sufficiency of developing arterial bed for converting a juxtaposed myocyte into a Purkinje fiber cell and provide evidence for an inductive function for arteriogenesis in heart development distinct from its role in establishing coronary blood circulation.

Cardiac allograft valvulopathy: a case of donor-anorexigen-induced valvular disease

We report on the transplantation of a cardiac allograft from a donor with prolonged exposure to anorexigens. This event allowed us to not only examine the early pathological alterations that characterize anorexigen-induced valvular damage, but to also study the posttransplantation outcome after the donor heart had been removed from the offending milieu. A donor history of anorexigen use should be sought, and if detected, careful evaluation for underlying valvular disease should be entertained. Early valvulopathy may appear clinically mild yet pathologically significant. Our single-case experience also suggests that anorexigen-induced valvulopathy may be a progressive disorder despite removal of the heart from the causative environment.

Overdiagnosis and overtreatment of Lyme neuroborreliosis are preventable

The problems of diagnosis and treatment of Lyme neuroborreliosis can be minimised by strictly following the clinical diagnostic criteria, and understanding the pitfalls of laboratory tests. The diagnosis is based solely on objective clinical findings, with serologic test results used only to confirm the diagnosis. It must be underscored that serologic testing, when ordered without regard for clinical presentation (i.e., used as a screen), may be misleading due to its extremely low positive predictive value. Enzyme-linked immunosorbent assay should always be confirmed by Western blot. The cerebrospinal fluid Borrelia burgdorferi antibody index is more meaningful than simple titres of specific antibody. Polymerase chain reaction is still a research tool and should not be utilised without clinical correlation. All serologic tests and polymerase chain reaction may remain positive long after successful treatment. Overdiagnosis and overtreatment can be minimised by following these guidelines.

Relationship of the C242T p22phox gene polymorphism to angiographic coronary artery disease and endothelial function

Patients with coronary artery disease (CAD) have impaired endothelial function in part due to an increase in vascular oxidant stress. p22phox, an essential component of the NADPH oxidase, is thought to play a critical role in the generation of superoxide anions in the vessel wall. The C242T polymorphism, located in the potential heme-binding site of the p22phox gene, has recently been reported to confer a protective effect on CAD risk in a Japanese study population. In a U.S. population of 252 patients (83% Caucasian) undergoing angiography for diagnosis of CAD, we investigated whether the C242T polymorphism was associated with the presence of CAD. In a subset of 142 patients, we studied whether the polymorphism manifests its potential protective effects through alteration of vascular endothelial function by measuring coronary epicardial and microvascular responses to intracoronary acetylcholine and sodium nitroprusside. Prevalence of the C242T allele was not different in 149 patients with CAD compared to 103 patients with angiographically normal coronary arteries (65.1% vs. 54.4%, P = 0.11). The C242T allele frequency in our population was nearly fourfold higher than reported previously in a Japanese population. There were also no significant differences in coronary epicardial or microvascular responses to acetylcholine or sodium nitroprusside between groups of patients with or without the C242T allele. In a U.S. population, the C242T polymorphism does not appear to confer protection from endothelial dysfunction or CAD. Am. J. Med. Genet. 86:57-61, 1999. Published 1999 Wiley-Liss, Inc.

Characteristic distributions of finite-time Lyapunov exponents

We study the probability densities of finite-time or local Lyapunov exponents in low-dimensional chaotic systems. While the multifractal formalism describes how these densities behave in the asymptotic or long-time limit, there are significant finite-size corrections, which are coordinate dependent. Depending on the nature of the dynamical state, the distribution of local Lyapunov exponents has a characteristic shape. For intermittent dynamics, and at crises, dynamical correlations lead to distributions with stretched exponential tails, while for fully developed chaos the probability density has a cusp. Exact results are presented for the logistic map, x-->4x(1-x). At intermittency the density is markedly asymmetric, while for "typical" chaos, it is known that the central limit theorem obtains and a Gaussian density results. Local analysis provides information on the variation of predictability on dynamical attractors. These densities, which are used to characterize the nonuniform spatial organization on chaotic attractors, are robust to noise and can, therefore, be measured from experimental data.

Glutathione reverses endothelial dysfunction and improves nitric oxide bioavailability

OBJECTIVES

We investigated whether glutathione (GSH), a reduced thiol that modulates redox state and forms adducts of nitric oxide (NO), improves endothelium-dependent vasomotion and NO activity in atherosclerosis.

BACKGROUND

Endothelial dysfunction and reduced NO activity are associated with atherosclerosis and its clinical manifestations such as unstable angina.

METHODS

In the femoral circulation of 17 patients with atherosclerosis or its risk factors, endothelium-dependent vasodilation with acetylcholine (ACH), and endothelium-independent vasodilation with nitroglycerin and sodium nitroprusside were studied before and after GSH. In 10 patients, femoral vein plasma cyclic guanylate monophosphate (cGMP) levels were measured during an infusion of ACH before and after GSH. Femoral artery flow velocity was measured using a Doppler flow wire and the resistance index (FVRI) calculated as mean arterial pressure divided by flow velocity.

RESULTS

Glutathione strongly potentiated ACH-mediated vasodilation; at the two doses, FVRI decreased by 47% and 56% before, and by 61% and 67% after GSH (p = 0.003). Glutathione also elevated cGMP levels in the femoral vein during ACH infusion from 17.6 +/- 3 to 23.3 +/- 3 pmol/ml (p = 0.006). Augmentation of ACH responses was only observed in patients with depressed endothelial function. Glutathione did not influence endothelium-independent vasodilation with either NO donor.

CONCLUSIONS

Thiol supplementation with GSH selectively improves human endothelial dysfunction by enhancing NO activity.

Effect of enalaprilat on nitric oxide activity in coronary artery disease

Atherosclerosis is associated with vascular endothelial dysfunction and reduced nitric oxide (NO) activity. Enhancement of NO activity may have an antiatherogenic action. This study was performed to determine whether angiotensin-converting enzyme (ACE) inhibition improves peripheral vascular NO activity in patients with atherosclerosis. In the femoral circulation of 43 patients with atherosclerosis and 10 controls, we studied endothelium-dependent vasodilation with bradykinin and acetylcholine, and endothelium-independent vasodilation with sodium nitroprusside before and after enalaprilat. In 22 patients, we repeated these infusions in the presence of L-N(G) monomethyl arginine (L-NMMA). Doppler-femoral artery flow velocity was measured. Before ACE inhibition, acetylcholine responses were depressed in patients with atherosclerosis compared with controls (p = 0.03). Enalaprilat did not alter femoral vascular tone at rest or vasodilation with sodium nitroprusside, but potentiated bradykinin-mediated vasodilation in patients (p<0.001) and controls (p = 0.02). Acetylcholine-mediated vasodilation was augmented only in patients (p<0.001), but not in control subjects. L-NMMA inhibited the potentiation by enalaprilat of acetylcholine and bradykinin responses. This study demonstrates that ACE inhibition selectively improves endothelial dysfunction in human atherosclerosis by enhancing NO activity. The antithrombotic and antiproliferative effects of NO may reduce adverse manifestations related to atherosclerosis during long-term therapy.