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Parenteral and enteral nutrition support are key components of care for various medical and physiological conditions in infants, children, and adults. Nutrition support practices have advanced over time, driven by the goals of safe and sufficient delivery of needed nutrients and improved patient outcomes. These advances have been, and continue to be, dependent on research and development studies. Such studies address aspects of enteral and parenteral nutrition support: formulations, delivery devices, health outcomes, cost-effectiveness, and related metabolism. The studies are supported by public funding from the government and by private funding from foundations and from the nutrition support industry. To build public trust in nutrition support research findings, it is important to underscore ethical research conduct and reporting of results for all studies, including those with industry sponsors. In 2019, American Society for Parenteral and Enteral Nutrition's (ASPEN's) Board of Directors established a task force to ensure integrity in nutrition support research that is done as collaborative partnerships between the public (government and individuals) and private groups (foundations, academia, and industry). In this ASPEN Position Paper, the Task Force presents principles of ethical research to guide administrators, researchers, and funders. The Task Force identifies ways to curtail bias and to minimize actual or perceived conflict of interests, as related to funding sources and research conduct. Notably, this paper includes a Position Statement to describe the Task Force's guidance on Public-Private Partnerships for research and funding. This paper has been approved by the ASPEN Board of Directors.

Context: Metatarsal stress fractures are common in cleated-sport athletes. Previous authors have shown that plantar loading varies with footwear, sex, and the athletic task. Objective: To examine the effects of shoe type and sex on plantar loading in the medial midfoot (MMF), lateral midfoot (LMF), medial forefoot (MFF), middle forefoot (MidFF), and lateral forefoot (LFF) during a jump-landing task. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty-seven recreational athletes (14 men, 13 women) with no history of lower extremity injury in the last 6 months and no history of foot or ankle surgery. Main Outcome Measure(s): The athletes completed 7 jumping trials while wearing bladed-cleat, turf-cleat, and running shoes. Maximum force, contact area, contact time, and the force-time integral were analyzed in each foot region. We calculated 2 × 3 analyses of variance (α = .05) to identify shoe-condition and sex differences. Results: We found no shoe × sex interactions, but the MMF, LMF, MFF, and LFF force-time integrals were greater in men (P < .03). The MMF maximum force was less with the bladed-cleat shoes (P = .02). Total foot and MidFF maximum force was less with the running shoes (P < .01). The MFF and LFF maximum forces were different among all shoe conditions (P < .01). Total foot contact area was less in the bladed-cleat shoes (P = .01). The MMF contact area was greatest in the running shoes (P < .01). The LFF contact area was less in the running shoes (P = .03). The MFF and LFF force-time integrals were greater with the bladed-cleat shoes (P < .01). The MidFF force-time integral was less in the running shoes (P < .01). Conclusions: Independent of shoe, men and women loaded the foot differently during a jump landing. The bladed cleat increased forefoot loading, which may increase the risk for forefoot injury. The type of shoe should be considered when choosing footwear for athletes returning to activity after metatarsal stress fractures.

Background— Early clinical studies demonstrated the feasibility of local paclitaxel delivery in reducing restenosis after treatment of de novo coronary lesions in small patient populations. Methods and Results— We conducted a randomized, double-blind trial of 536 patients at 38 medical centers evaluating slow-release (SR) and moderate-release (MR) formulations of a polymer-based paclitaxel-eluting stent (TAXUS) for revascularization of single, primary lesions in native coronary arteries. Cohort I compared TAXUS-SR with control stents, and Cohort II compared TAXUS-MR with a second control group. The primary end point was 6-month percent in-stent net volume obstruction measured by intravascular ultrasound. Secondary end points were 6-month angiographic restenosis and 6- and 12-month incidence of major adverse cardiac events, a composite of cardiac death, myocardial infarction, and repeat revascularization. At 6 months, percent net volume obstruction within the stent was significantly lower for TAXUS stents (7.9% SR and 7.8% MR) than for respective controls (23.2% and 20.5%; P P P =0.0002). The incidence of major adverse cardiac events at 12 months was significantly lower ( P =0.0192) in the TAXUS-SR (10.9%) and TAXUS-MR (9.9%) groups than in controls (22.0% and 21.4%, respectively), predominantly because of a significant reduction in repeat revascularization of the target lesion in TAXUS-treated patients. Conclusions— Compared with a bare metal stent, paclitaxel-eluting stents reduced in-stent neointimal formation and restenosis and improved 12-month clinical outcome of patients with single de novo coronary lesions.

Lower-extremity injury is common in soccer. A number of studies have begun to assess why specific lower-extremity injuries occur. However, currently few studies have examined how footwear affects lower-extremity mechanics. In order to address this question, 14 male (age: 22.1 ± 3.9 years, height: 1.77 ± 0.06 m, and mass: 73.3 ± 11.5 kg) and 14 female (age: 22.8 ± 3.1 years, height: 1.68 ± 0.07 m and mass: 64.4 ± 9.2 kg) competitive soccer players underwent a motion analysis assessment while performing a jump heading task. Each subject performed the task in three different footwear conditions (running shoe, bladed cleat, and turf shoe). Two-way analyses of variance were used to examine statistical differences in landing mechanics between the footwear conditions while controlling for gender differences. These comparisons were made during two different parts (prior to and following) of a soccer-specific jump heading task. A statistically significant interaction for the peak dorsiflexion angle (P = 0.02) and peak knee flexion angle (P = 0.05) was observed. Male soccer players exhibited a degree increase in dorsiflexion in the bladed cleat while female soccer players exhibited a three-degree reduction in peak knee flexion in the bladed cleat condition. Other main effects for gender and footwear were also observed. The results suggest that landing mechanics differ based upon gender, footwear, and the type of landing. Therefore, training interventions aimed at reducing lower-extremity injury should consider utilizing sport-specific footwear when assessing movement patterns.

Aims: Defining vessel diameters and angles that comprise coronary side-branch intersections could assist in tailoring treatments to match anatomy, improve haemodynamic flow, and minimise mechanical trauma. We sought to characterise intersections of main vessels and side-branches by measuring actual diameters, angles, and shapes at the ostia in human coronary arteries. Methods and results: Polymer casts were created using coronary trees from 23 adult cadaver hearts. Seventy-five arterial intersections between main vessels and side-branches were captured using the combination of a microscope (Smartscope MVP100) and computer program (Gage-X metrology software) specifically calibrated for video-based inspection and measurement (34-fold magnification). The intersection between main vessels and side-branches was a multifaceted, curvilinear transition rather than a bisecting angle. The shape of the ostia was typically elliptical rather than circular. Mean diameters were 2.88 mm in proximal main vessels, 2.34 mm in ostia, and 2.00 mm in side-branches (first-level branches). Obtuse proximal (150 degrees) and distal (111 degrees) angles with accentuated side-branch taper create a "barn door" effect with wider curvature at the bottom. Conclusions: Matching treatments to these various forms of asymmetry at the main vessel-to-side-branch intersection may minimise injury and optimise scaffolding, and haemodynamic flow.

Objectives: The multicenter, single-arm BEACH (Boston Scientific EPI: A Carotid Stenting Trial for High-Risk Surgical Patients) evaluated outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EX/EZ Emboli Protection System (Boston Scientific, Natick, Massachusetts). Background: Carotid artery stent (CAS) placement offers a less invasive alternative for high-risk surgical carotid endarterectomy (CEA) patients. Methods: The trial enrolled 480 pivotal patients who were candidates for carotid revascularization but considered high surgical risk due to pre-specified anatomic criteria and/or medical comorbidities. The primary end point (all stroke, death, or Q-wave myocardial infarction [MI] through 30 days; non-Q-wave MI through 24 h; and ipsilateral stroke or neurologic death through 1 year) was compared with a proportionally weighted objective performance criterion (OPC) of 12.6% for published surgical endarterectomy results in similar patients, plus a pre-specified noninferiority margin of 4%. Results: Among pivotal patients, 41.2% were at high surgical risk due to comorbid risk factors, and 58.8% due to anatomic risk factors; 76.7% were asymptomatic with flow-limiting carotid stenosis >80%. At 1 year, the composite primary end point occurred in 8.9% (40 of 447), with a repeat revascularization rate of 4.7%. With an upper 95% confidence limit of 11.5% for the primary composite end point, the BEACH trial results met the pre-specified criteria for noninferiority relative to the calculated OPC plus noninferiority margin (16.6%) for historical surgical CEA outcomes in similar patients (p < 0.0001 for noninferiority). Conclusions: The BEACH trial results demonstrate that CAS with the WALLSTENT plus FilterWire embolic protection is non-inferior (equivalent or better than) to CEA at 1-year in high-surgical-risk patients (Boston Scientific Embolic Protection, Inc. [EPI]: A Carotid Stenting Trial for High-Risk Surgical Patients [BEACH]; http://clinicaltrials.gov/ct2/show/NCT00316108?term=NCT00316108r NCT00316108).

Late loss has been used as a reliable surrogate end point for evaluation and differentiation of short-term performance of drug-eluting stents. This study investigated the consistency between angiographic and intravascular ultrasound (IVUS) outcomes of late lumen loss (late loss) and neointimal growth to measure restenotic plaque load in TAXUS and bare metal stents. The randomized TAXUS II trial evaluates the polymer-based paclitaxel-eluting TAXUS stent in slow- and moderate-release formulations. Serial angiographic and IVUS analyses were available in 155 event-free patients (bare metal stent, 74; TAXUS stent, 81) after the procedure, at 6 months, and at 2 years. For this subanalysis, quantitative coronary angiographic (QCA) and IVUS measurements were used to derive late loss and neointimal volume. From after the procedure to 6 months, quantitative coronary angiography and IVUS showed matching results for the 2 groups with significant decreases in late loss and neointimal volume in the TAXUS versus the control group. From 6 months to 2 years, QCA and IVUS measurements also showed results similar to those in the control group, demonstrating neointimal compaction over time. However, in the TAXUS group, QCA late loss showed a nonsignificant decrease from 6 months to 2 years, whereas IVUS neointimal volume increased. In conclusion, although QCA and IVUS results were similar over the first 6 months, long-term assessment of changes in restenotic plaque load showed discrepant findings for the TAXUS. These findings suggest the need for critical reevaluation of current end points and the use of more precise techniques to detect lumen and stent boundaries.

The use of a medical device outside of its approved label is commonly referred to as “off-label use.” Off-label use arises when physicians see the opportunity to leverage an approved therapy for an unmet patient need. This practice typically occurs on a case by case basis without clear documentation of indication, frequency, or outcomes. Sponsors have a responsibility to consider formal indication expansion depending on the actual use, how well the therapy fits the unmet need, product iteration cycles, adoption speed, resource demands, and the clinical risk to benefit ratio. This responsibility is particularly relevant for breakthrough technologies where adoption patterns can span a variety of uses. For Boston Scientific's drug-eluting stent program, a surveillance program was developed in collaboration with the FDA to compile information on practice patterns and safety outcomes for the TAXUS® Express2™ Paclitaxel-Eluting Coronary Stent System. The ARRIVE program has used a Web-based format to collect real-time data on TAXUS stent use. This >7,000 patient registry documents both on-label and off-label use and key safety measures for the TAXUS stent. This real-world registry has successfully provided a data-driven approach to BSC's product development strategy, including the initiation of formal label expansion programs. For complex or combination products, more innovative ways of capturing risk to benefit data are needed to define off-label use and to maximize the potential therapeutic utility as supported by safety data.

Objectives This study sought to compare aggregate medical care costs for patients undergoing percutaneous coronary intervention with paclitaxel-eluting stents (PES) and bare-metal stents (BMS) and to formally evaluate the incremental cost effectiveness of PES for patients undergoing single-vessel percutaneous coronary intervention. Background Although the cost effectiveness of SES has been studied in both clinical trials and decision-analytic models, few data exist on the cost effectiveness of alternative drug-eluting stent (DES) designs. In addition, no clinical trials have specifically examined the cost effectiveness of DES among patients managed without mandatory angiographic follow-up. Methods We performed a prospective economic evaluation among 1,314 patients undergoing percutaneous coronary revascularization randomized to either PES (N = 662) or BMS (N = 652) in the TAXUS-IV trial. Clinical outcomes, resource use, and costs (from a societal perspective) were assessed prospectively for all patients over a 1-year follow-up period. Cost effectiveness was defined as the incremental cost per target vessel revascularization (TVR) event avoided and was analyzed separately among cohorts assigned to mandatory angiographic follow-up (n = 732) or clinical follow-up alone (n = 582). Results The PES reduced TVR by 12.2 events per 100 patients treated, resulting in a 1-year cost difference of $572 per patient with incremental cost-effectiveness ratios of $4,678 per TVR avoided and $47,798/quality-adjusted life year (QALY) gained. Among patients assigned to clinical follow-up alone, the net 1-year cost difference was $97 per patient with cost-effectiveness ratios of $760 per TVR event avoided and $5,105/QALY gained. Conclusions In the TAXUS-IV trial, treatment with PES led to substantial reductions in the need for repeat revascularization while increasing 1-year costs only modestly. The cost-effectiveness ratio for PES in the study population compares reasonably with that for other treatments that reduce coronary restenosis, including alternative drug-eluting stent platforms.

Objectives The objectives of the study were to evaluate the effect of angiographic follow-up on revascularization rates in the TAXUS-IV trial and to determine whether the relative benefit of paclitaxel-eluting stent implantation compared with bare metal stent implantation was modified by angiographic follow-up. Background Although several clinical trials have demonstrated that drug-eluting stents (DES) reduce restenosis compared with bare-metal stents (BMS), virtually all of these studies have incorporated angiographic follow-up. Methods In the TAXUS-IV trial, 1,314 percutaneous coronary intervention patients were randomized to receive paclitaxel-eluting stents (PES) (n = 662) or identical-appearing BMS (n = 652). Clinical outcomes were compared, stratified by assignment to angiographic follow-up or clinical follow-up alone. Results Compared with clinical follow-up alone, angiographic follow-up patients had a significantly higher rate of target vessel revascularization (TVR) at 1 year (adjusted hazard ratio [HR] 1.46; p = 0.04), with similar relative increases in PES and BMS patients. Because PES reduced TVR by ∼60% regardless of type of follow-up, assignment to angiographic follow-up tended to overestimate the absolute benefit of PES relative to clinical follow-up alone. In contrast, assessment of end points immediately before the time of follow-up angiography led to substantial underestimation of the absolute benefit of PES implantation. Conclusions Performance of mandatory angiographic follow-up increases rates of TVR among patients receiving both BMS and PES and overestimates the absolute clinical benefits of PES relative to clinical follow-up alone. Nonetheless, PES substantially reduces TVR regardless of assignment to mandatory angiographic follow-up or not. Future studies designed to determine the true clinical benefits of DES should either forgo routine angiographic follow-up or separate the time of repeat angiography from the primary clinical end point by as long as possible.

OBJECTIVES To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions. BACKGROUND Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm. METHODS The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis

Background: The BEACH trial evaluated the outcomes of carotid artery stent placement with distal emboli protection, using the Carotid Wallstent® and the FilterWire EX®/EZTM, in patients at high surgical risk for carotid endarterectomy (CEA). Methods: We enrolled 747 patients at high surgical risk for CEA due to prespecified anatomical criteria and/or medical comorbidities. The trial included both symptomatic (>50% carotid artery stenosis) as well as asymptomatic (>80% carotid artery stenosis) high surgical risk patients. Three groups of patients were included in the trial. The Roll-in (R) group (n = 189/747, [25%]) included up to nine patients per site for familiarization of the device and protocol; the Pivotal (P) group (n = 480/747, [65%]) was intended for presentation to the FDA for consideration of device approval; and a Bilateral (B) registry group (n = 78/747, [10%]) was included because of the need to treat patients with bilateral carotid artery disease. In the 480 Pivotal patients, anatomic criteria represented the most frequent high-risk surgical category for enrollment (58.8%), followed by prior CEA (34.2%), multivessel (≥2) coronary artery disease (21.7%), and contralateral carotid occlusion (18.1%). Results: The technical success rate for stent deployment and FilterWire EX/EZ deployment and retrieval was 98.2%. The mean postprocedure angiographic diameter stenosis in the Pivotal group was reduced to 10.8%, while the overall procedure success rate (

Background— Intracoronary polymer-based stent delivery of paclitaxel has been shown to be effective in reducing restenosis in simple coronary lesions, but the evidence base for contemporary use in longer, more complex coronary stenoses is lacking. Methods and Results— TAXUS VI is a prospective, multicenter, double-blind, randomized trial assessing clinical and angiographic outcomes of the TAXUS Moderate Release paclitaxel-eluting stent in the treatment of long, complex coronary artery lesions. Four hundred forty-eight patients at 44 sites were randomized (1:1) between a drug-eluting TAXUS Express 2 and an uncoated Express 2 control stent. Per protocol, the 9-month follow-up included an angiographic reevaluation in all patients. The primary end point was the rate of target-vessel revascularization 9 months after the study procedure; secondary end points included the rate of target-lesion revascularization and binary restenosis at follow-up. Mean lesion length in the study was 20.6 mm, with a mean stent-covered length of 33.4 mm. Of all lesions, 55.6% were classified as complex lesions (type C of the AHA/ACC classification). At 9 months, target-vessel revascularization was 9.1% in the TAXUS group and 19.4% in the control group ( P =0.0027; relative reduction, 53%). Target-lesion revascularization was reduced from 18.9% to 6.8%, respectively ( P =0.0001). The incidence of major adverse cardiac events was similar in the 2 groups, 16.4% and 22.5% in TAXUS and control, respectively ( P =0.12), including comparable rates for acute myocardial infarction. Binary restenosis in the stented area was reduced from 32.9% in the control group to 9.1% in the TAXUS patients ( P Conclusions— The finding that the TAXUS Moderate Release stent system is safe and effective in the treatment of long, complex coronary artery lesions provides the evidence base for the more widespread use of drug-eluting stents in contemporary clinical practice.

The enzyme dipeptidyl peptidase-IV (DPP-4) inactivates the incretin hormone glucagon-like peptide-1 (GLP-1). Because GLP-1 has therapeutic effects in patients with type 2 diabetes, but its potential is limited by a short half-life, DPP-4 inhibition is a promising approach to diabetes treatment. This study examined acute (single dose) and chronic (once-a-day dosing for 21 days) effects of the DPP-4 inhibitor vildagliptin (0.03-10 mg/kg) on plasma DPP-4 activity, intact GLP-1, glucose, and insulin after an oral glucose load in insulin-resistant Zucker fatty rats and acute effects in mildly insulin-resistant high-fat-fed normal rats. A single oral dose of vildagliptin in Zucker rats produced a rapid and dose-related inhibition of DPP-4: the minimum effective dose (MED) was 0.3 mg/kg. Glucose-induced increases of intact GLP-1 were greatly but similarly enhanced by vildagliptin at doses > or =0.3 mg/kg. Postload glucose excursions decreased, and the insulinogenic index (Deltainsulin/Deltaglucose at 10 min) increased, with an MED of 0.3 mg/kg and a maximally effective dose of 3 mg/kg. The effects of vildagliptin after chronic treatment were nearly identical to those of acute administration, and vildagliptin had no effect on body weight. In fat-fed normal rats, vildagliptin (3 mg/kg) also decreased postload glucose excursions and increased the insulinogenic index, but these effects were smaller than those in Zucker rats. Thus, vildagliptin is an orally effective incretin enhancer with antihyperglycemic activity in insulin-resistant rats and exhibits no tachyphylaxis. GLP-1-mediated augmentation of glucose-induced insulin release seems to make the major contribution to the antidiabetic properties of vildagliptin.

Objectives We sought to examine the efficacy of paclitaxel-eluting stent implantation in the left anterior descending coronary artery (LAD). Background Restenosis and recurrent cardiac events after percutaneous intervention are more common for lesions in the LAD than other native coronary arteries, and often necessitate bypass surgery. Drug-eluting stents may improve the long-term prognosis of this high-risk group. Methods In the TAXUS-IV trial, 1,314 patients with single de novo coronary lesions were assigned to implantation of the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or an identical bare-metal stent; 536 (41%) randomized patients had LAD lesions. Results Baseline characteristics of patients with LAD lesions were well-matched between the randomized groups. Late lumen loss at nine months after paclitaxel-eluting and control stent implantation were 0.28 ± 0.51 mm and 0.54 ± 0.57 mm, respectively (p = 0.0004), and binary restenosis rates were 11.3% and 26.9%, respectively (p = 0.004). At one year, major adverse cardiac events (MACE) occurred in 13.5% of TAXUS-treated patients versus 21.2% treated with the control stent (p = 0.01). The need for bypass surgery at one year was reduced among patients randomized to the TAXUS stent (2.6% vs. 6.3%, p = 0.02). In the proximal LAD subgroup (n = 126), the one-year target vessel revascularization rate was 7.9% with the TAXUS stent and 18.6% with the bare-metal stent (p = 0.009). Conclusions Compared to bare-metal stents, implantation of polymer-based, paclitaxel-eluting stents in LAD lesions is safe, and reduces angiographic restenosis and MACE one year. Notably, the need for bypass graft surgery due to restenosis is reduced after TAXUS stent implantation in LAD lesions.

Objectives We sought to determine the safety and efficacy of polymer-regulated site-specific delivery of paclitaxel in patients with diabetes mellitus undergoing stent implantation. Background Percutaneous coronary intervention in patients with diabetes is associated with high rates of restenosis and repeat revascularization due to excessive neointimal proliferation, a process that may be blunted with the site-specific delivery of paclitaxel. Methods In the TAXUS-IV trial, 1,314 patients were prospectively randomized to the slow rate-release polymer-based paclitaxel-eluting TAXUS stent or the bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). Medically treated diabetes was present in 318 patients (24%), 105 of whom required insulin. Results Among patients with diabetes, the TAXUS stent, compared to the bare-metal stent, reduced the rate of 9-month binary angiographic restenosis by 81% (6.4% vs. 34.5%, p Conclusions The site-specific delivery of paclitaxel after coronary stent implantation is highly effective in reducing clinical and angiographic restenosis in patients with diabetes mellitus.

Objectives The aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effects of polymer-based, paclitaxel-eluting stents on in-stent neointima formation and late incomplete stent apposition. Background The TAXUS-IV trial demonstrated that the slow-release, polymer-based, paclitaxel-eluting stent reduces angiographic restenosis and the need for repeat revascularization procedures. Serial IVUS studies reveal details of the pattern of vascular responses provoked by stent implantation that provide insight into device safety and efficacy. Methods In the TAXUS-IV trial, patients were randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). As part of a formal substudy, complete volumetric IVUS data were available in 170 patients, including 88 TAXUS patients and 82 controls, at implantation and at nine-month follow-up. Results No baseline differences were present in the clinical characteristics or IVUS parameters between the control and TAXUS groups. At nine-month follow-up, IVUS lumen volumes were larger in the TAXUS group (123 ± 43 mm3vs. 104 ± 44 mm3, p = 0.005), due to a reduction in neointimal volume (18 ± 18 mm3vs. 41 ± 23 mm3, p Conclusions Polymer-based, paclitaxel-eluting TAXUS stents are effective in inhibiting neointimal tissue proliferation, and do not result in late incomplete stent apposition.

Objectives We sought to investigate the outcomes of paclitaxel-eluting stent implantation in patients with unstable angina or non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention (PCI). Background Whether the paclitaxel-eluting stent is safe and effective in patients with acute coronary syndromes (ACS) is unknown. Methods In the TAXUS-IV trial, 1,314 patients with stable or unstable ischemic syndromes undergoing PCI were randomized to treatment with either the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). The results were stratified by the acuity of the presenting clinical syndrome. Results Acute coronary syndromes were present in 450 patients (34.2%), 237 of whom were assigned to paclitaxel-eluting stents and 213 to bare-metal stents. The baseline and procedural characteristics were well matched between the groups. Clinical outcomes at 30 days were similar with both stents. At one-year follow-up, patients with ACS assigned to the paclitaxel-eluting stent compared to the control stent had strikingly lower rates of target lesion revascularization (TLR) (3.9% vs. 16.0%, p Conclusions The use of the paclitaxel-eluting TAXUS stent was safe in patients with unstable ischemic syndromes, and was associated with marked reduction of ischemia-driven TLR and adverse cardiac events at one year.

The effect of obesity on repeat coronary revascularization and restenosis in patients who undergo stent implantation has not been reported. We therefore examined the database from the multicenter randomized TAXUS-IV trial to determine the effect of body mass index (BMI) on outcomes after bare-metal and drug-eluting stent implantation. In TAXUS-IV, patients were randomized to receive a slow-release, polymer-based, paclitaxel-eluting stent or a bare-metal stent. Outcomes were stratified by baseline BMI. Of the 1,307 randomized patients who had documented BMI, 233 (17.8%) had normal weight (BMI25 kg/m2), 531 (40.6%) were overweight (BMIor =25 to 30 kg/m2), and 543 (41.5%) were obese (BMIor =30 kg/m2). Patients who had been assigned to receive bare-metal stents and were overweight and obese compared with those who had normal weight had higher rates of 9-month binary restenosis (29.2% and 30.5% vs 9.3%, respectively; p = 0.01) and 1-year major adverse cardiac events (20.8% and 23.2% vs 11.1%, respectively; p = 0.02), whereas rates of these events did not differ significantly among those who received a paclitaxel-eluting stent (7.6% and 9.3% vs 4.9%, respectively for binary restenosis; p = 0.65; 11.3% and 10.4% vs 10.1%, respectively; p = 0.82 for major adverse cardiac events). By multivariate analysis, BMIor =30.0 kg/m2 independently predicted binary restenosis (hazard ratio 4.26, p = 0.005), 1-year target vessel revascularization (hazard ratio 1.95, p = 0.04), and major adverse cardiac events (hazard ratio 1.95, p = 0.004) in patients who received bare-metal stents but not paclitaxel-eluting stents. In conclusion, obesity is an important risk factor for clinical and angiographic restenosis and for composite major adverse cardiac events in patients who receive bare-metal stents. Paclitaxel-eluting stents attenuate the increased risk associated with obesity, such that the intermediate-term prognosis after percutaneous coronary intervention is independent of weight.

Background— The purpose of this study was to evaluate long-term vascular responses as long as 2 years after implantation of polymer-based, paclitaxel-eluting stents in contrast to uncoated stents. Methods and Results— TAXUS II is a randomized, double-blind trial comparing slow-release (SR) and moderate-release (MR) TAXUS stents with bare-metal control stents (BMSs). One hundred sixty-one event-free patients (SR, 43; MR, 41; and BMS, 77) underwent serial intravascular ultrasound (IVUS) analysis after the procedure and at 6 months and 2 years. At 2 years, neointimal responses continued to be significantly suppressed in the SR and MR groups when compared with the BMS group (BMS, 1.49±1.12 mm 2 ; SR, 0.94±0.76 mm 2 [ P =0.004]; and MR, 1.06±0.90 mm 2 [ P =0.02]). Between 6 months and 2 years, the BMS group showed compaction of the neointima (Δ, −0.22±1.05 mm 2 [ P =0.08]). In contrast, both the SR and MR groups exhibited an increase (Δ SR, 0.30±0.76 mm 2 ( P =0.01); MR, 0.41±0.94 mm 2 [ P =0.009]). Between 6 months and 2 years, the initial increase in plaque outside the stent regressed in the BMS and SR groups to levels comparable to those after the procedure, whereas expansive remodeling partially regressed in the MR group (Δ between after the procedure and 2 years BMS, −0.34±1.28 mm 2 [ P =0.05]; SR, −0.02±1.40 mm 2 [ P =0.93]; MR, 0.32±1.56 mm 2 [ P =0.27]). Conclusions— The 2-year follow-up demonstrates that neointimal suppression was dose independent and that this effect was still sustained at 2 years. However, the increase in area outside the stent seen at 6 months regressed to different extents in a dose-dependent manner at 2 years.

Background— The clinical impact of late incomplete stent apposition (ISA) for drug-eluting stents is unknown. We sought to prospectively investigate the incidence and extent of ISA after the procedure and at 6-month follow-up of paclitaxel-eluting stents in comparison with bare metal stents (BMS) and survey the clinical significance of ISA over a period of 12 months. Methods and Results— TAXUS II was a randomized, double-blind study with 536 patients in 2 consecutive cohorts comparing slow-release (SR; 131 patients) and moderate-release (MR; 135 patients) paclitaxel-eluting stents with BMS (270 patients). This intravascular ultrasound (IVUS) substudy included patients who underwent serial IVUS examination after the procedure and at 6 months (BMS, 240 patients; SR, 113; MR, 116). The qualitative and quantitative analyses of ISA were performed by an independent, blinded core laboratory. More than half of the instances of ISA observed after the procedure resolved at 6 months in all groups. No difference in the incidence of late-acquired ISA was observed among the 3 groups (BMS, 5.4%; SR, 8.0%; MR, 9.5%; P =0.306), with a similar ISA volume (BMS, 11.4 mm 3 ; SR, 21.7 mm 3 ; MR, 8.5 mm 3 ; P =0.18). Late-acquired ISA was the result of an increase of vessel area without change in plaque behind the stent. Predictive factors of late-acquired ISA were lesion length, unstable angina, and absence of diabetes. No stent thrombosis occurred in the patients diagnosed with ISA over a period of 12 months. Conclusions— The incidence and extent of late-acquired ISA are comparable in paclitaxel-eluting stents and BMS. ISA is a pure IVUS finding without clinical repercussions.

Objectives The Study to COmpare REstenosis Rate between QueST and QuaDDS-QP2 (SCORE) trial was a multicenter, randomized, open-label trial comparing the safety and performance of 13- and 17-mm QuaDDS stents (n = 126) (Quanam Medical Corp., Santa Clara, California/Boston Scientific Corp., Natick, Massachusetts) versus uncoated control stents (n = 140) in focal, de novo coronary lesions. Background The pioneering drug-delivery QuaDDS stent used four to six acrylate polymer sleeves, each loaded with 800 μg of the paclitaxel derivative 7-hexanoyltaxol. Methods Clinical end points were assessed at 1, 6, and 12 months post procedure. Quantitative coronary angiography and intravascular ultrasound were performed post procedure and at six-month follow-up. Results In the QuaDDS group, early stent thrombosis and myocardial infarction (MI) rates were significantly higher, leading to premature cessation of enrollment. For the QuaDDS group, the stent thrombosis rate increased from 3.2% to 10.3% between 1 and 12 months, associated with increased non–Q-wave MI and death rates. The angiographic restenosis rate at six months was reduced from 32.7% (control) to 7.4% (p Conclusions Despite angiographic indications of potential anti-restenotic benefit, increased rates of stent thrombosis, MI, and cardiac death associated with the QuaDDS stent show an unacceptable safety profile.

Background— The safety and efficacy of the slow-release, polymer-based, paclitaxel-eluting stent after implantation in a broad cross section of de novo coronary lesions at 1 year are unknown. Methods and Results— In the TAXUS-IV trial, 1314 patients with single de novo coronary lesions 10 to 28 mm in length, with reference-vessel diameter 2.5 to 3.75 mm, coverable by a single study stent, were prospectively randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or an identical-appearing bare-metal EXPRESS stent. By actuarial analysis, the TAXUS stent compared with the bare-metal stent reduced the 12-month rates of target-lesion revascularization by 73% (4.4% versus 15.1%, P P P P P =0.007), target-vessel revascularizations (2.4% versus 5.8%, P =0.002), and major adverse cardiac events (2.4% versus 6.3%, P =0.0009) in the paclitaxel-eluting stent than in the control stent group, respectively. Conclusions— The relative efficacy reported at 9 months for the polymer-based, paclitaxel-eluting TAXUS stent compared with the EXPRESS stent is preserved and continues to increase at 1 year, with no safety concerns apparent.

Background— On the basis of brachytherapy experience, edge stenosis has been raised as a potential limitation for drug-eluting stents. We used serial intravascular ultrasound (IVUS) to prospectively analyze vessel responses in adjacent reference segments after implantation of polymer-controlled paclitaxel-eluting stents. Methods and Results— TAXUS II was a randomized, double-blind trial with 2 consecutive patient cohorts that compared slow-release (SR) and moderate-release (MR) paclitaxel-eluting stents with control bare metal stents (BMS). By protocol, all patients had postprocedure and 6-month follow-up IVUS. Quantitative IVUS analysis was performed by an independent core laboratory, blinded to treatment allocation, in 5-mm vessel segments immediately proximal and distal to the stent. Serial IVUS was available for 106 SR, 107 MR, and 214 BMS patients. For all 3 groups, a significant decrease in proximal-edge lumen area was observed at 6 months. The decrease was comparable (by ANOVA, P =0.194) for patients in the SR (−0.54±2.1 mm 2 ) and MR (−0.88±1.9 mm 2 ) groups compared with the BMS (−1.02±1.9 mm 2 ) group. For the distal edge, a significant decrease in lumen area was only observed with BMS (−0.91±2.0 mm 2 , P 2 ) and MR (−0.19±1.7 mm 2 ) stents ( P 2 , P =0.011) but not the distal edges of BMS and at neither edge of SR or MR stents. Conclusions— The marked reduction in in-stent restenosis with SR or MR stents is not associated with increased edge stenosis at 6-month follow-up IVUS. In fact, compared with BMS, there is instead a significant reduction in late lumen loss at the distal edge with TAXUS stents.

Restenosis after coronary stenting necessitates repeated percutaneous or surgical revascularization procedures. The delivery of paclitaxel to the site of vascular injury may reduce the incidence of neointimal hyperplasia and restenosis.At 73 U.S. centers, we enrolled 1314 patients who were receiving a stent in a single, previously untreated coronary-artery stenosis (vessel diameter, 2.5 to 3.75 mm; lesion length, 10 to 28 mm) in a prospective, randomized, double-blind study. A total of 652 patients were randomly assigned to receive a bare-metal stent, and 662 to receive an identical-appearing, slow-release, polymer-based, paclitaxel-eluting stent. Angiographic follow-up was prespecified at nine months in 732 patients.In terms of base-line characteristics, the two groups were well matched. Diabetes mellitus was present in 24.2 percent of patients; the mean reference-vessel diameter was 2.75 mm, and the mean lesion length was 13.4 mm. A mean of 1.08 stents (length, 21.8 mm) were implanted per patient. The rate of ischemia-driven target-vessel revascularization at nine months was reduced from 12.0 percent with the implantation of a bare-metal stent to 4.7 percent with the implantation of a paclitaxel-eluting stent (relative risk, 0.39; 95 percent confidence interval, 0.26 to 0.59; P0.001). Target-lesion revascularization was required in 3.0 percent of the group that received a paclitaxel-eluting stent, as compared with 11.3 percent of the group that received a bare-metal stent (relative risk, 0.27; 95 percent confidence interval, 0.16 to 0.43; P0.001). The rate of angiographic restenosis was reduced from 26.6 percent to 7.9 percent with the paclitaxel-eluting stent (relative risk, 0.30; 95 percent confidence interval, 0.19 to 0.46; P0.001). The nine-month composite rates of death from cardiac causes or myocardial infarction (4.7 percent and 4.3 percent, respectively) and stent thrombosis (0.6 percent and 0.8 percent, respectively) were similar in the group that received a paclitaxel-eluting stent and the group that received a bare-metal stent.As compared with bare-metal stents, the slow-release, polymer-based, paclitaxel-eluting stent is safe and markedly reduces the rates of clinical and angiographic restenosis at nine months.

Background— The TAXUS NIRx stent (Boston Scientific Corp) provides local delivery of paclitaxel via a slow-release polymer coating. The TAXUS I trial was the first in-human experience evaluating safety and feasibility of the TAXUS NIRx stent system compared with bare NIR stents (control) (Boston Scientific Corp) for treatment of coronary lesions. Methods and Results— The TAXUS I trial was a prospective, double-blind, three-center study randomizing 61 patients with de novo or restenotic lesions (≤12 mm) to receive a TAXUS (n=31) versus control (n=30) stent (diameter 3.0 or 3.5 mm). Demographics, lesion characteristics, clinical outcomes were comparable between the groups. The 30-day major adverse cardiac event (MACE) rate was 0% in both groups ( P =NS). No stent thromboses were reported at 1, 6, 9, or 12 months. At 12 months, the MACE rate was 3% (1 event) in the TAXUS group and 10% (4 events in 3 patients) in the control group ( P =NS). Six-month angiographic restenosis rates were 0% for TAXUS versus 10% for control ( P =NS) patients. There were significant improvements in minimal lumen diameter (2.60±0.49 versus 2.19±0.65 mm), diameter stenosis (13.56±11.77 versus 27.23±16.69), and late lumen loss (0.36±0.48 versus 0.71±0.48 mm) in the TAXUS group (all P 3 ) group compared with the control group (21.6 mm 3 ) ( P Conclusions— In this feasibility trial, the TAXUS slow-release stent was well tolerated and showed promise for treatment of coronary lesions, with significant reductions in angiographic and intravascular ultrasound measures of restenosis.

Dipeptidyl peptidase IV (DPP-IV) inhibition has the potential to become a valuable therapy for type 2 diabetes. We report the first use of solid-phase synthesis in the discovery of a new DPP-IV inhibitor class and a solution-phase synthesis that is practical up to the multikilogram scale. One compound, NVP-DPP728 (2), is profiled as a potent, selective, and short-acting DPP-IV inhibitor that has excellent oral bioavailability and potent antihyperglycemic activity.

Provision of adequate T cell costimulation is critical for the development of acute and chronic allograft rejection. We have previously reported that early blockade of CD28-B7 T cell costimulation prevents the development of graft arteriosclerosis, in the LEW into F344 rat cardiac transplant model. In this study, we used the same model to examine the requirement for CD28-B7-mediated T cell costimulation in the progression of established chronic rejection and examined the individual roles of B7-1 (CD80) and B7-2 (CD86) costimulatory molecules. Late blockade of CD28-B7 T cell costimulation by the fusion protein CTLA4Ig, which binds both CD80 and CD86, attenuated the development of transplant arteriosclerosis, mononuclear cell infiltration, and parenchymal fibrosis in this model. Selective blockade of CD80 using the mutant fusion protein Y100F was as effective as CTLA4Ig in this regard. In contrast to CTLA4Ig, blockade of CD80 alone by Y100F was ineffective at preventing early graft loss and prolonging graft survival when given early after transplantation. This study is the first to demonstrate that late blockade of CD28-B7 T cell costimulation interrupts chronic cardiac allograft rejection, and it indicates the importance of continued T cell activation in this process. This study further defines functional differences between CD80 and CD86 costimulatory molecules in vivo.

Structure–activity relationship within a series of 1-aminoalkylisoquinoline-4-carboxylates as inhibitors of DPP-IV is described. A primary aminomethyl group is required to maintain biological activity. Substitution of the isoquinoline at the 6- and 8-positions with methoxy groups increases potency to 53 times that of the lead compound SDZ 029-576.

Background —To study transcription factor signaling pathways that mediate cardiac allograft vasculopathy, we used mice with targeted gene deletion of signal transducer and activator of transcription (STAT)4 and STAT6 as recipients in our mouse cardiac transplant model of chronic rejection. Methods and Results —At day 55 after transplantation, cardiac grafts placed into STAT4 −/− (n=10) had reduced frequency (24±2%) and severity (9±4%) of vascular occlusion compared with wild-type controls (n=7, frequency 70±12% [ P P 32 P RT-PCR and immunohistochemistry) of the Th1 signature cytokines interferon-γ ( P P + mononuclear cells (99±27 cells/mm 3 compared with 551±168 cells/mm 3 in wild-type controls [ P P P Conclusions —Hence, we show that immune responses mediated by STAT4, but not STAT6, contribute to the development of cardiac allograft vasculopathy. We speculate that when present, STAT4-mediated signaling pathways may promote cardiac allograft vasculopathy by directing Th1-specific lymphocyte recruitment, activation, and effector functions.

Inhibition of dipeptidyl peptidase IV (DPP-IV) has been proposed recently as a therapeutic approach to the treatment of type 2 diabetes. N-Substituted-glycyl-2-cyanopyrrolidide compounds, typified by NVP-DPP728 (1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S )-p yrrolidine), inhibit degradation of glucagon-like peptide-1 (GLP-1) and thereby potentiate insulin release in response to glucose-containing meals. In the present study NVP-DPP728 was found to inhibit human DPP-IV amidolytic activity with a K(i) of 11 nM, a k(on) value of 1.3 x 10(5) M(-)(1) s(-)(1), and a k(off) of 1.3 x 10(-)(3) s(-)(1). Purified bovine kidney DPP-IV bound 1 mol/mol [(14)C]-NVP-DPP728 with high affinity (12 nM K(d)). The dissociation constant, k(off), was 1.0 x 10(-)(3) and 1.6 x 10(-)(3) s(-)(1) in the presence of 0 and 200 microM H-Gly-Pro-AMC, respectively (dissociation t(1/2) approximately 10 min). Through kinetic evaluation of DPP-IV inhibition by the D-antipode, des-cyano, and amide analogues of NVP-DPP728, it was determined that the nitrile functionality at the 2-pyrrolidine position is required, in the L-configuration, for maximal activity (K(i) of 11 nM vs K(i) values of 5.6 to300 microM for the other analogues tested). Surprisingly, it was found that the D-antipode, despite being approximately 500-fold less potent than NVP-DPP728, displayed identical dissociation kinetics (k(off) of 1.5 x 10(-)(3) s(-)(1)). NVP-DPP728 inhibited DPP-IV in a manner consistent with a two-step inhibition mechanism. Taken together, these data suggest that NVP-DPP728 inhibits DPP-IV through formation of a novel, reversible, nitrile-dependent complex with transition state characteristics.

Background: Mice with target gene deletions were used in an immunosuppressed, heterotopic mouse cardiac transplant model to investigate the effects of simultaneous deficiencies of ICAM-1 and P-selectin on late cardiac rejection. Methods To determine the contribution of donor sources of ICAM-1 and P-selectin, ICAM-1/P-selectin gene deficient (I/P −/−) ( n = 7) or wild type ( n = 6) donor hearts were placed into CBA recipients. To study recipient sources of ICAM-1 and P-selectin, wild type donor hearts were placed into I/P −/− ( n = 7) or wild type ( n = 13) recipients. Recipients received a 30-day course of anti-CD4/8 mAb. Results I/P −/− donor allografts had prolonged survival (52–57 days) compared with wild type allografts (49–51 days). I/P −/− donor allografts underwent parenchymal rejection with mononuclear cell infiltration and developed α-smooth muscle actin positive vascular thickening (30 ± 7% luminal occlusion, n = 78 vessels). Wild type allografts had parenchymal rejection with vascular medial necrosis and an absence of arteriosclerotic thickening (10 ± 8%, n = 75, p = 0.008). Using the reverse combination, allografts from I/P −/− or wild type recipients had similar graft survival (50–57 days), comparable but variable degrees of parenchymal rejection, and comparable vascular occlusion (22 ± 15% vs 28 ± 19%, p = 0.442). Conclusion We have shown that donor and recipient sources of ICAM-1 and P-selectin may have independent roles in leukocyte trafficking to the graft. Simultaneous interruption of donor ICAM-1 and P-selectin delays onset of parenchymal rejection. However, donor I/P deficiency permits arteriosclerotic development, perhaps by attenuating the alloimmune injury. In contrast, recipient deficiency alone does not altergraft outcomes suggesting that the donor is the critical site of ICAM-1 and P-selectin.

It has been reported previously that one-third of protocol renal biopsies in asymptomatic, biochemically stable renal transplant recipients in the first 6 mo show unsuspected subclinical graft rejection (both infiltrate and tubulitis) and that subclinical rejection is a risk factor for chronic renal dysfunction. This study was performed to determine whether differences in phenotype or activation status of graft-infiltrating cells underlie these different manifestations of acute rejection. Biopsies with normal histology (n = 10), subclinical rejection (n = 13), and clinical rejection (n = 9) were studied using immunohistochemistry and computerized image analysis. Subclinical and clinical rejections had similar histologic Banff scores. Univariate analysis showed a trend for a higher infiltration with CD8+ (P = 0.053) and CD68+(P = 0.06) cells in clinical rejection. Of the activation markers studied (CD25, perforin, tumor necrosis factor-alpha), only allograft inflammatory factor-1+-activated macrophages were significantly (P = 0.014) increased in the infiltrate of clinical rejection biopsies. These data suggest that activated macrophages or their products are responsible for acute renal dysfunction associated with clinical rejection episodes.

This article reviews macrophage biology in general, macrophage activation in the transplanted organ, and potential roles of the macrophage in chronic rejection and arteriosclerosis.

The cutaneous growth of Leishmania mexicana was measured in STAT6-deficient mice (STAT6−/−) and compared with that in similarly infected wild-type (STAT6+/+) mice. Following s.c. inoculation with 5 × 106 amastigotes of L. mexicana into the shaven rump, STAT6+/+ mice developed large, nonhealing cutaneous lesions, while STAT6−/− mice failed to develop detectable lesions during most of the course of study. As infection progressed, STAT6+/+ mice infected with L. mexicana displayed significantly higher titers of Leishmania-specific IgG1 and IgE compared with STAT6−/− mice, which conversely produced significantly higher titers of Leishmania-specific IgG2a, indicating development of a Th1-like response in the latter group. At 12 wk postinfection, Leishmania Ag-stimulated lymph node cells from STAT6−/− mice produced significantly higher amounts of IL-12 and IFN-γ than those from STAT6+/+ mice as measured by ELISA. However, there was no significant difference in IL-4 production between the two groups. Semiquantitative RT-PCR of transcript levels in intact draining lymph nodes and skin from inoculation sites confirmed a similar pattern of cytokines in vivo as that observed in stimulated lymph node cells in vitro. These results indicate that STAT6-mediated IL-4 signaling is critical for progression of L. mexicana infection in genetically susceptible mice and demonstrate that in the absence of STAT6, susceptible mice default toward a Th1-like response and control cutaneous L. mexicana infection.

BACKGROUND To evaluate cardiac allografts from recipients that had achieved peripheral tolerance after transient CD4+ T cell depletion, we analyzed cellular infiltrate, cytokine expression, and vascular thickening. Long-surviving cardiac allografts from tolerant recipients were compared with acutely rejecting allografts and isografts. METHODS AND RESULTS In CBA mice treated with anti-CD4 (GK1.5, 0.5 mg intraperitoneally on days 1-28), BALB/c cardiac allografts survived >100 days. These recipients were tested for tolerance at >70 days, by challenge with donor and third-party (C57BL/6) skin grafts. BALB/c skin grafts survived >30 days, although C57BL/6 skin was rejected in

To investigate the role of interleukin (IL)-10 in late graft outcomes, we compared BALB/c donor hearts transplanted into immunosuppressed wild-type or IL-10 gene-deficient (−/−) C57BL recipients (n = 49) at 50 ± 5 days. There was prominent leukocyte infiltration and parenchymal destruction with more severe vascular occlusion in grafts from IL-10 −/− recipients. An occlusive CD45+ arteritis with medial necrosis occurred with IL-10 deficiency instead of the α-smooth muscle actin-rich arteriosclerosis seen in wild-type recipients. Increased interferon (IFN)-γ as well as Mac-1, inducible nitric oxide synthase, and allograft inflammatory factor-1 (but not CD3 and IL-4) transcript levels were seen in allografts from IL-10 −/− recipients as assessed by 32P reverse transcription polymerase chain reaction. We then evaluated the contribution of IFN-γ-mediated responses by neutralizing IFN-γ. Anti-IFN-γ monoclonal antibody (MAb) treatment of IL-10 −/− recipients did not improve graft survival, parenchymal rejection, or occlusive arteritis, indicating that these processes are IFN-γ independent. However, medial smooth muscle cell loss in IL-10 −/− recipients was attenuated by anti-IFN-γ MAb. Hence, in this transplant model, IL-10 suppresses T cell and macrophage responses in the parenchyma and vasculature and confers a protective effect against late rejection.

To compare regulatory effects of NOS2 in acute and chronic cardiac allograft rejection, we used NOS2 knockout mice as recipients in a cardiac transplant model. To study acute and chronic rejection separately but within the same genetic strain combination, we compared allografts placed into recipients without or with immunosuppression (anti-CD4/8 for 28 days). NOS2 mRNA and protein expression were compared using 32 P-RT-PCR and immunohistochemistry. In our acute rejection model, NOS2 was predominately localized to graft-infiltrating immune cells. At day 7, grafts in NOS2-deficient recipients ( n = 7) showed reduced inflammatory infiltrates and myocyte damage resulting in significantly lower rejection scores (1.6 ± 0.4) compared to wild-type controls ( n = 18; 2.8 ± 0.2, P = 0.002). In contrast, in our chronic rejection model, additional NOS2 expression was localized to graft-parenchymal cells. At day 55, grafts in NOS2-deficient recipients ( n = 12) showed more parenchymal infiltration and parenchymal destruction (rejection score 3.8 ± 0.1) than wild-type controls ( n = 15; 1.6 ± 0.2, P P

Background —Inducible NO synthase (NOS2, or iNOS) is upregulated in grafts with transplant arteriosclerosis. However, the functional role of NOS2 in the pathogenesis of transplant arteriosclerosis remains unclear. NOS2 may regulate lesion development by modulating the early alloimmune response and/or late myointimal thickening. Methods and Results —To determine whether NOS2-mediated pathways protect against or promote transplant arteriosclerosis, we used NOS2-deficient mice as recipients in our vascularized chronic cardiac rejection model. The severity of vascular thickening in 55-day grafts placed into NOS2 −/− recipients (n=13) was compared with that in wild-type recipients (n=15). Computer-assisted analysis of all elastin-stained vessels (n=283) showed significantly increased luminal occlusion (77.1±9.4% versus 40.8±13.6%, P P =.0002). To elucidate potential mechanisms, we studied NOS2 effects on T-cell differentiation (Th 1 /Th 2 ) and neointimal smooth muscle cell accumulation. Normalized mRNA levels for Th 1 - (signal transducer and activator of transcription [STAT] 4, interleukin [IL]-2, interferon-γ) and Th 2 - (STAT 6, IL-4, and IL-5) associated factors were comparable in both groups. In contrast, quantitative analysis of the α-actin–positive area showed a significant increase in the contribution of smooth muscle cells within the neointima in allografts from NOS2 −/− recipients (28.2±2.0%) compared with wild-type controls (13.2±2.3%; P Conclusions —NOS2 plays a protective role in the development of transplant arteriosclerosis, suppressing neointimal smooth muscle cell accumulation.

To study the role of cytokines in long-term cardiac allografts we have used recipient mice with targeted gene deletions (-/-) in IFN-gamma, IL-4, or IL-10. In wild-type and IL-4 -/- recipients immunosuppressed with a 30-d course of anti-CD4 and anti-CD8, graft survival was > 87 d. This time was significantly reduced in IFN-gamma -/- (62 +/- 19 d, P < 0.05) and IL-10 -/- recipients (55 +/- 4 d, P < 0.0001). Histology showed mononuclear cell infiltration, patchy necrosis, fibrosis, and vascular thickening in all groups. Intragraft transcript levels measured by 32P-reverse transcriptase PCR showed different inflammatory patterns. IFN-gamma -/- recipients had higher IL-2 transcripts and selective alteration in macrophage activation that may have contributed to decreased graft survival. Decreased graft survival in IL-10 -/- recipients was associated with increases in iNOS and IFN-gamma-driven responses. Finally, in grafts from IL-4 -/- recipients, there were increases in CD3 transcripts concurrent with TNF-alpha levels. This increase suggests that IL-4 may regulate T cell infiltration through TNF-alpha-mediated inflammatory cell recruitment. Concurrent evaluation of these three isolated cytokine deletions has shown that the recipient environment caused distinct graft modifications.

Abstract We evaluated inflammatory activation and vascular thickening in a heterotopic murine heart transplant model. C57BL/6J recipient mice received anti-CD4 therapy (days 1 to 4 after transplantation) or sustained, combined anti-CD4/CD8 therapy (days 1 to 4, weekly thereafter). Morphometric analysis of grafts (>95 days) found the mean percentage of vessel occlusion to be 51.7% in allografts treated with anti-CD4, 8.3% in allografts treated with sustained anti-CD4/CD8, and 6.7% in isografts. Mean transcript levels of the adhesion molecules P-selectin, intercellular adhesion molecule 1 (ICAM-1), and leukocyte function-associated antigen 1 (LFA-1) and the cytokines interleukin 4 (IL-4), interferon-γ (IFN-γ), inducible nitric oxide synthase (iNOS), allograft inflammatory factor 1 (AIF-1), and monocyte chemoattractant protein 1 (MCP-1) were measured with reverse transcription–polymerase chain reaction [RT-PCR] assays using deoxycytidine triphosphate radiolabeled with phosphorus 32 [ 32 P-dCTP]. The assays were normalized against glyceraldehyde-3-phosphate dehydrogenase [G3PDH] Levels were found to be significantly higher in the anti-CD4 group than in the anti-CD4/CD8 group. A strong correlation was also found between the percentage of luminal occlusion and the expression of these markers of inflammation ( r =.92-.99, P

Background If complement (C) activation is prevented or the host is C depleted, discordant vascularized xenografts undergo delayed xenograft rejection (DXR), characterized by graft infiltration by macrophages (MO) and natural killer (NK) cells, endothelial cell activation, and widespread fibrin deposition. Given a lack of effect of T cell-directed therapies on development of DXR, we evaluated two novel agents, 15-deoxyspergualin (DSG) and leflunomide (LEF), with reported anti-B-cell and/or anti-MO actions. Methods. DSG and LEF were administered to C-depleted, splenectomized rat recipients of guinea pig cardiac xenografts, and their effects on graft survival and production of anti-guinea pig antibodies were determined. Serial intragraft events were studied by immunohistology using monoclonal antibodies to rat leukocytes, cytokines, and novel proteins, including rat MO lectin, which in other systems is important to MO binding, activation, and target cell killing. Results. Median graft survival was 62 hr in cobra venom factor (CVF)-treated controls versus 108 hr (DSG), 129 hr (LEF), and 120 hr (DSG and LEF; all groups P

Chronic rejection is a T cell-dependent process and blockade of the CD28-B7 T-cell costimulatory activation pathway by the fusion protein CTLA4Ig has been shown to prevent the development of accelerated graft arteriosclerosis in a rat model of chronic cardiac allograft rejection. The effectiveness of T-cell costimulatory blockade at preventing chronic allograft rejection in a clinically relevant model in combination with cyclosporine therapy has not been investigated. Using the well-established LEW into F334 heterotopic cardiac allograft model, we show that when cyclosporine is administered in combination with CTLA4Ig, it abrogates the previously demonstrated protective effect of CTLA4Ig in preventing chronic allograft rejection. Long-term surviving allografts from animals treated with a combination of cyclosporine and CTLA4Ig had a mean vascular luminal occlusion of 42.2%, affecting more than 90% of graft vessels due to accelerated arteriosclerosis. This was associated with up-regulation of intragraft expression of mRNA for CD4, the costimulatory molecule B7, the T-cell cytokine interferon-gamma, monocyte chemoattractant protein-1, and the fibrogenic growth factor transforming growth factor-beta; all have been previously shown to be associated with development of chronic rejection in this model. In comparison, the addition of donor splenocytes to the combination of CTLA4Ig and cyclosporine therapy protocol significantly reduced the amount of arteriosclerosis; mean vascular luminal occlusion was 11.3%, affecting approximately 50% of vessels. This was associated with decreased intragraft expression of CD4, B7, interferon-gamma, monocyte chemoattractant protein-1, and transforming growth factor-beta. These data indicate that the mechanism of action of CTLA4Ig in attenuating chronic rejection is cyclosporine sensitive, and that strategies implying combination of CTLA4Ig and cyclosporine may not be clinically desirable. Administration of donor antigen may be necessary if CTLA4Ig and cyclosporine are to be combined, to prevent the process of chronic rejection.

Blocking CD28-B7 T-cell costimulation by CTLA4Ig induces tolerance to rat renal allografts and inhibits Th1, but spares Th2, cytokines. We now report on the mechanisms of CD28-B7 blockade in this model. Lymphocytes from CTLA4Ig-treated animals showed significant reduction of mixed lymphocyte response, as well as antidonor cytotoxic T-cell effector function, as compared with rejecting controls. Flow cytometry studies on sera of renal allograft recipients showed complete inhibition of antidonor humoral responses by CTLA4Ig. Analysis by reverse transcriptase-polymerase chain reaction and immunohistology showed that intragraft macrophage products, monocyte chemoattractant protein-1 and inducible nitric oxide synthase, were reduced by CTLA4Ig therapy. Immunohistologic studies also showed reduced intragraft macrophage infiltration and decreased staining for the fibrogenic and mitogenic growth factor, transforming growth factor-beta. These results indicate that CD28-B7 blockade inhibits cell-mediated and humoral immune responses, and suggest that strategies targeting T-cell costimulation may provide a novel approach to prevent chronic allograft rejection.

Recent animal studies suggest that indirect T-cell recognition of alloantigen plays an important role in allograft rejection and tolerance. In this study, we generated T cell clones from Lewis (LEW, RT1(l)) rat lymph node cells that had been primed in vivo by immunization with immunogenic class II MHC allopeptide RT1.D(u)beta2, representing residues 20-44 of the polymorphic beta chain of RT1.Dbeta(u) (Wistar Furth [WF]). Using reverse transcriptase polymerase chain reaction transcript analysis with specific rat T cell receptor Vbeta primers, we show that six out of nine T cell clones specifically proliferated to RT1.D(u)beta2 and expressed Vbeta 9. One of these clones, clone 2F4, which specifically proliferated to RT1.D(u)beta2 in a dose-response fashion and produced interferon-gamma in response to restimulation by RT1.D(u)beta2, was selected for further studies. The beta-chains of RT1.D(l) and RT1.D(u) residues 20-44 differ by two amino acids at positions 30 and 38. We synthesized two peptides, each containing a single polymorphic site: RT1.D(u)beta 20-33 and RT1.D(u)beta 31-44. Both these peptides were immunogenic by LEW responders, since lymph node cells primed by immunization proliferated equally to the peptides in vitro. Interestingly, in vitro dose-response studies with clone 2F4 showed better proliferative response to peptide RT1.D(u)beta 20-33 than to peptide RT1.D(u)beta 31-44, indicating that this T cell clone preferentially recognizes a single amino acid difference on residue 30. Finally, it has been suggested that indirect allorecognition by CD4+ T cells mediate graft rejection by delayed-type hypersensitivity responses, although definitive studies are lacking. Systemic injection of the 2F4 clone to naive LEW rats elicited an antigen-specific delayed-type hypersensitivity response against RT1.D(u)beta2 peptide and WF splenocytes, confirming indirect presentation in vivo. These data demonstrate that Th1 cell clones generated by in vivo priming via the indirect pathway utilize specific T cell receptor Vbeta and recognize single amino acid differences in the allopeptide. More importantly,these Th1 clones are capable of mediating a specific immune response in vivo. These studies with MHC allopeptide-specific T cell clones further delineate the cellular mechanisms of indirect allorecognition and provide a potential strategy to study its role in acute and chronic rejection, and tolerance.

A series of phosphorus-containing analogs of cholesteryl ester have been synthesized as potential inhibitors of cholesteryl ester transfer protein (CETP). The most potent inhibitor, phosphonate 7 , represents a novel inhibitor of CETP.

CTLA4Ig, a fusion protein that blocks CD28-B7 costimulation, was studied in a LEW to F344 rat model of chronic cardiac rejection. In rats treated with a single dose of CTLA4Ig (0.5 mg intraperitoneally) 2 d after transplantation, allografts survived significantly longer ( > 70 d in 64%) than in untreated controls or rats treated with control Ig (all rejected within 25 d). Only 25% of grafts from rats treated with a single, high dose of cyclosporine A (25 mg/kg, 2 d after transplantation) survived longer than 70 d. Reverse transcriptase PCR and immunostaining analyses of tissue from 75-d, CTLA4Ig-treated allografts showed reduced expression of the T cell factor IFN-gamma and macrophage activation factors monocyte chemoattractant protein-1, inducible nitric oxide synthase, and galactose/N-acetylgalactosamine macrophage lectin, as well as TGF-beta. Grafts from longterm survivors ( > 120 d) treated with CTLA4Ig showed significant reductions in the frequency and severity of arteriosclerosis in comparison with cyclosporine A-treated rats. Thus, T cell activation is a proximal event in the cascade that culminates in the arteriosclerosis of chronic rejection. Strategies for blocking T cell costimulation may help prevent chronic rejection in clinical transplantation.