Striatal insights: a cellular and molecular perspective on repetitive behaviors in pathology.

Animals often behave repetitively and predictably. These repetitive behaviors can have a component that is learned and ingrained as habits, which can be evolutionarily advantageous as they reduce cognitive load and the expenditure of attentional resources. Repetitive behaviors can also be conscious and deliberate, and may occur in the absence of habit formation, typically when they are a feature of normal development in children, or neuropsychiatric disorders. They can be considered pathological when they interfere with social relationships and daily activities. For instance, people affected by obsessive-compulsive disorder, autism spectrum disorder, Huntington's disease and Gilles de la Tourette syndrome can display a wide range of symptoms like compulsive, stereotyped and ritualistic behaviors. The striatum nucleus of the basal ganglia is proposed to act as a master regulator of these repetitive behaviors through its circuit connections with sensorimotor, associative, and limbic areas of the cortex. However, the precise mechanisms within the striatum, detailing its compartmental organization, cellular specificity, and the intricacies of its downstream connections, remain an area of active research. In this review, we summarize evidence across multiple scales, including circuit-level, cellular, and molecular dimensions, to elucidate the striatal mechanisms underpinning repetitive behaviors and offer perspectives on the implicated disorders. We consider the close relationship between behavioral output and transcriptional changes, and thereby structural and circuit alterations, including those occurring through epigenetic processes.

Evaluating the impact of a Risk Evaluation and Mitigation Strategy with tolvaptan to monitor liver safety in patients with autosomal dominant polycystic kidney disease.

Background: On approval of JYNARQUE (tolvaptan) for use in patients with autosomal dominant polycystic kidney disease (ADPKD) at risk for rapid progression, the US Food and Drug Administration required a Risk Evaluation and Mitigation Strategy (REMS) from the sponsor, which includes collection of post marketing liver safety data. Methods: This is a retrospective interim analysis of the ongoing REMS. The period evaluated was from REMS implementation (14 May 2018) at tolvaptan commercialization to the analysis cutoff date (23 February 2021). Patients were previously tolvaptan-naïve and initiated tolvaptan in the post marketing setting. Reports of possible severe drug-induced liver injury (DILI) were evaluated for severity based on the evidence obtained (e.g. liver enzyme levels, symptoms, diagnostic tests and event outcomes). The incidence of DILI was compared between the REMS and tolvaptan clinical trials in ADPKD. Results: Among 6711 REMS patients, 60 (0.9%) cases of possible severe DILI were reported, 4 of which were confirmed as serious and potentially fatal by the sponsor. One of these four patients met Hy's law criteria. In all four patients, liver enzymes normalized after tolvaptan discontinuation. The duration of tolvaptan exposure in the REMS is currently shorter than in completed clinical trials, but within this limitation, the incidence of possible severe DILI was lower in the REMS than in clinical trials (incidence rate ratio 0.587; P = .000411). Conclusions: In interim data on >6000 tolvaptan REMS patients, <1% experienced possible severe DILI. Monthly monitoring, as described in the tolvaptan prescribing information, enables the prompt detection of liver enzyme abnormalities and appropriate drug discontinuation.

Low-density neutrophils in chronic graft versus host disease (cGVHD) are primarily immature CD10- and enhance T cell activation.

Chronic graft-versus-host disease (cGVHD) is a frequent complication of allogeneic haematopoietic stem cell transplantation. Low density neutrophils (LDNs) in autoimmunity, which shares disease features with cGVHD, are proinflammatory, whereas those in cancer and sepsis suppress T cell immunity. Mature LDNs can be distinguished from immature LDNs on the basis of expression of CD10 and suppressive neutrophils can be identified using lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) expression. The functionality of LDNs in cGVHD has not been specifically investigated. Here, we have determined the relative contribution of immature and mature neutrophils to LDNs in cGVHD and assessed whether these were suppressive or potentially proinflammatory. Peripheral blood LDNs and normal density neutrophils (NDNs) from 30 cGVHD patients and NDNs from 10 healthy controls (HCs) were immunophenotyped by flow cytometry. The ability of LDNs and NDNs to influence T cell proliferation and cytokine production in co-cultures was quantified. To further characterize LDNs, their propensity to undergo constitutive apoptosis and differentiate ex vivo was assessed. LDNs were elevated in cGVHD versus HCs, heterogeneous in phenotype, with a predominance of immature CD10- cells in most patients, but some mature CD10+ LOX-1+ LDNs were also detected. LDNs enhanced autologous T cell proliferation, interleukin (IL)-6 and interferon (IFN)-γ production. LDN, but not NDN, CD10 expression was inversely correlated with LOX-1, which correlated with IL-6 production. LDNs resisted apoptosis and differentiated into antigen-presenting/neutrophil-hybrid-like cells, which co-expressed major histocompatibility complex (MHC) class II HLA-DR and immuno-inhibitory programmed cell death ligand 1 (PD-L1), but did not suppress T cell proliferation. These data suggest LDNs in cGVHD are predominantly immature, proinflammatory and may have pathogenic potential.

Monitoring lung function in patients with chronic graft versus host disease: a pilot study.

Bronchiolitis obliterans syndrome (BOS) following allogenic haematopoietic stem cell transplant is considered the manifestation of chronic graft versus host disease (cGvHD) in the lung, and affects about 14% of patients with cGvHD, mainly in the first 2 years after transplant. Despite advances in assessment, diagnosis and treatment, the clinical prognosis remains poor for patients with pulmonary manifestations of cGvHD. A pilot study of 50 patients was devised to establish whether a relationship exists between forced expiratory volume in 1 second (FEV1) via pulmonary function test (PFT) and the equivalent peak expiratory flow (PEF) via peak flow handheld spirometry in cGvHD patients receiving extracorporeal photopheresis (ECP). Only PEF observed within 2 days of PFT could be compared with data at month 3, 6, 9 and 12. This pilot study illustrated that monitoring via handheld peak flow readings has the potential to become an acceptable method of monitoring lung function longitudinally in cGvHD patients.

Antithrombotic Therapy in Patients With Atrial Fibrillation and Acute Coronary Syndrome Treated Medically or With Percutaneous Coronary Intervention or Undergoing Elective Percutaneous Coronary Intervention: Insights From the AUGUSTUS Trial.

BACKGROUND: The safety and efficacy of antithrombotic regimens may differ between patients with atrial fibrillation who have acute coronary syndromes (ACS), treated medically or with percutaneous coronary intervention (PCI), and those undergoing elective PCI. METHODS: Using a 2×2 factorial design, we compared apixaban with vitamin K antagonists and aspirin with placebo in patients with atrial fibrillation who had ACS or were undergoing PCI and were receiving a P2Y12 inhibitor. We explored bleeding, death and hospitalization, as well as death and ischemic events, by antithrombotic strategy in 3 prespecified subgroups: patients with ACS treated medically, patients with ACS treated with PCI, and those undergoing elective PCI. RESULTS: Of 4614 patients enrolled, 1097 (23.9%) had ACS treated medically, 1714 (37.3%) had ACS treated with PCI, and 1784 (38.8%) had elective PCI. Apixaban compared with vitamin K antagonist reduced International Society on Thrombosis and Haemostasis major or clinically relevant nonmajor bleeding in patients with ACS treated medically (hazard ratio [HR], 0.44 [95% CI, 0.28-0.68]), patients with ACS treated with PCI (HR, 0.68 [95% CI, 0.52-0.89]), and patients undergoing elective PCI (HR, 0.82 [95% CI, 0.64-1.04]; Pinteraction=0.052) and reduced death or hospitalization in the ACS treated medically (HR, 0.71 [95% CI, 0.54-0.92]), ACS treated with PCI (HR, 0.88 [95% CI, 0.74-1.06]), and elective PCI (HR, 0.87 [95% CI, 0.72-1.04]; Pinteraction=0.345) groups. Compared with vitamin K antagonists, apixaban resulted in a similar effect on death and ischemic events in the ACS treated medically, ACS treated with PCI, and elective PCI groups (Pinteraction=0.356). Aspirin had a higher rate of bleeding than did placebo in patients with ACS treated medically (HR, 1.49 [95% CI, 0.98-2.26]), those with ACS treated with PCI (HR, 2.02 [95% CI, 1.53-2.67]), and those undergoing elective PCI (HR, 1.91 [95% CI, 1.48-2.47]; Pinteraction=0.479). For the same comparison, there was no difference in outcomes among the 3 groups for the composite of death or hospitalization (Pinteraction=0.787) and death and ischemic events (Pinteraction=0.710). CONCLUSIONS: An antithrombotic regimen consisting of apixaban and a P2Y12 inhibitor without aspirin provides superior safety and similar efficacy in patients with atrial fibrillation who have ACS, whether managed medically or with PCI, and those undergoing elective PCI compared with regimens that include vitamin K antagonists, aspirin, or both. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02415400.

Pellino-1 Regulates Immune Responses to Haemophilus influenzae in Models of Inflammatory Lung Disease.

Non-typeable Haemophilus influenzae (NTHi) is a frequent cause of lower respiratory tract infection in people with chronic obstructive pulmonary disease (COPD). Pellino proteins are a family of E3 ubiquitin ligases that are critical regulators of TLR signaling and inflammation. The aim of this study was to identify a role for Pellino-1 in airway defense against NTHi in the context of COPD. Pellino-1 is rapidly upregulated by LPS and NTHi in monocyte-derived macrophages (MDMs) isolated from individuals with COPD and healthy control subjects, in a TLR4 dependent manner. C57BL/6 Peli1-/- and wild-type (WT) mice were subjected to acute (single LPS challenge) or chronic (repeated LPS and elastase challenge) airway inflammation followed by NTHi infection. Both WT and Peli1-/- mice develop airway inflammation in acute and chronic airway inflammation models. Peli1-/- animals recruit significantly more neutrophils to the airway following NTHi infection which is associated with an increase in the neutrophil chemokine, KC, in bronchoalveolar lavage fluid as well as enhanced clearance of NTHi from the lung. These data suggest that therapeutic inhibition of Pellino-1 may augment immune responses in the airway and enhance bacterial clearance in individuals with COPD.

Safety and Efficacy Outcomes 3 Years After Switching to Belatacept From a Calcineurin Inhibitor in Kidney Transplant Recipients: Results From a Phase 2 Randomized Trial.

BACKGROUND: In a phase 2 study, kidney transplant recipients of low immunologic risk who switched from a calcineurin inhibitor (CNI) to belatacept had improved kidney function at 12 months postconversion versus those continuing CNI therapy, with a low rate of acute rejection and no transplant loss. STUDY DESIGN: 36-month follow-up of the intention-to-treat population. SETTING & PARTICIPANTS: CNI-treated adult kidney transplant recipients with stable transplant function (estimated glomerular filtration rate [eGFR], 35-75mL/min/1.73m2). INTERVENTIONS: At 6 to 36 months posttransplantation, patients were randomly assigned to switch to belatacept-based immunosuppression (n=84) or continue CNI-based therapy (n=89). OUTCOMES: Safety was the primary outcome. eGFR, acute rejection, transplant loss, and death were also assessed. MEASUREMENTS: Treatment exposure-adjusted incidence rates for safety, repeated-measures modeling for eGFR, Kaplan-Meier analyses for efficacy. RESULTS: Serious adverse events occurred in 33 (39%) belatacept-treated patients and 36 (40%) patients in the CNI group. Treatment exposure-adjusted incidence rates for serious infections (belatacept vs CNI, 10.21 vs 9.31 per 100 person-years) and malignancies (3.01 vs 3.41 per 100 person-years) were similar. More patients in the belatacept versus CNI group had any-grade viral infections (14.60 vs 11.00 per 100 person-years). No posttransplantation lymphoproliferative disorder was reported. Belatacept-treated patients had a significantly greater estimated gain in mean eGFR (1.90 vs 0.07mL/min/1.73m2 per year; P for time-by-treatment interaction effect = 0.01). The probability of acute rejection was not significantly different for belatacept (8.38% vs 3.60%; HR, 2.50 [95% CI, 0.65-9.65; P=0.2). HR for the comparison of belatacept to the CNI group for time to death or transplant loss was 1.00 (95% CI, 0.14-7.07; P=0.9). LIMITATIONS: Exploratory post hoc analysis with a small sample size. CONCLUSIONS: Switching patients from a CNI to belatacept may represent a safe approach to immunosuppression and is being further explored in an ongoing phase 3b trial.

Nicotinic acid and DP1 blockade: studies in mouse models of atherosclerosis.

The use of nicotinic acid to treat dyslipidemia is limited by induction of a "flushing" response, mediated in part by the interaction of prostaglandin D(2) (PGD(2)) with its G-protein coupled receptor, DP1 (Ptgdr). The impact of DP1 blockade (genetic or pharmacologic) was assessed in experimental murine models of atherosclerosis. In Ptgdr(-/-)ApoE(-/-) mice versus ApoE(-/-) mice, both fed a high-fat diet, aortic cholesterol content was modestly higher (1.3- to 1.5-fold, P < 0.05) in Ptgdr(-/-)ApoE(-/-) mice at 16 and 24 weeks of age, but not at 32 weeks. In multiple ApoE(-/-) mouse studies, a DP1-specific antagonist, L-655, generally had a neutral to beneficial effect on aortic lipids in the presence or absence of nicotinic acid treatment. In a separate study, a modest increase in some atherosclerotic measures was observed with L-655 treatment in Ldlr(-/-) mice fed a high-fat diet for 8 weeks; however, this effect was not sustained for 16 or 24 weeks. In the same study, treatment with nicotinic acid alone generally decreased plasma and/or aortic lipids, and addition of L-655 did not negate those beneficial effects. These studies demonstrate that inhibition of DP1, with or without nicotinic acid treatment, does not lead to consistent or sustained effects on plaque burden in mouse atherosclerotic models.

Safety and efficacy of ezetimibe added on to rosuvastatin 5 or 10 mg versus up-titration of rosuvastatin in patients with hypercholesterolemia (the ACTE Study).

The present multicenter, 6-week, randomized, double-blind, parallel-group, clinical trial evaluated the safety and efficacy of ezetimibe (10 mg) added to stable rosuvastatin therapy versus up-titration of rosuvastatin from 5 to 10 mg or from 10 to 20 mg. The study population included 440 subjects at moderately high/high risk of coronary heart disease with low-density lipoprotein (LDL) cholesterol levels higher than the National Cholesterol Education Program Adult Treatment Panel III recommendations (<100 mg/dl for moderately high/high-risk subjects without atherosclerotic vascular disease or <70 mg/dl for high-risk subjects with atherosclerotic vascular disease). Pooled data demonstrated that ezetimibe added to stable rosuvastatin 5 mg or 10 mg reduced LDL cholesterol by 21%. In contrast, doubling rosuvastatin to 10 mg or 20 mg reduced LDL cholesterol by 5.7% (between-group difference of 15.2%, p <0.001). Individually, ezetimibe plus rosuvastatin 5 mg reduced LDL cholesterol more than did rosuvastatin 10 mg (12.3% difference, p <0.001), and ezetimibe plus rosuvastatin 10 mg reduced LDL cholesterol more than did rosuvastatin 20 mg (17.5% difference, p <0.001). Compared to rosuvastatin up-titration, ezetimibe add-on achieved significantly greater attainment of LDL cholesterol levels of <70 or <100 mg/dl (59.4% vs 30.9%, p <0.001), and <70 mg/dl in all subjects (43.8% vs 17.5%, p <0.001); produced significantly greater reductions in total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B (p <0.001); and resulted in similar effects on other lipid parameters. Adverse experiences were generally comparable among the groups. In conclusion, compared to up-titration doubling of the rosuvastatin dose, ezetimibe 10 mg added to stable rosuvastatin 5 mg or 10 mg produced greater improvements in many lipid parameters and achieved greater attainment of the National Cholesterol Education Program Adult Treatment Panel III recommended LDL cholesterol targets in subjects with elevated LDL cholesterol and at moderately high/high coronary heart disease risk.

The comparative efficacy of ezetimibe added to atorvastatin 10 mg versus uptitration to atorvastatin 40 mg in subgroups of patients aged 65 to 74 years or greater than or equal to 75 years.

BACKGROUND: Coronary heart disease (CHD) risk increases with age; yet lipid-lowering therapies are significantly under-utilized in patients > 65 years. The objective was to evaluate the safety and efficacy of lipid-lowering therapies in older patients treated with atorvastatin 10 mg + ezetimibe 10 mg (EZ/Atorva) vs. increasing the atorvastatin dose to 40 mg. METHODS: Patients ≥ 65 years with atherosclerotic vascular disease (LDL-C ≥ 1.81 mmol/L) or at high risk for coronary heart disease (LDL-C ≥ 2.59 mmol/L) were randomized to EZ/Atorva for 12 wk vs. uptitration to atorvastatin 20 mg for 6 wk followed by atorvastatin 40 mg for 6 wk. The percent change in LDL-C and other lipid parameters and percent patients achieving prespecified LDL-C levels were assessed after 12 wk. RESULTS: EZ/Atorva produced greater reductions in most lipid parameters vs. uptitration of atorvastatin in patients ≥ 75 years (n = 228), generally consistent with patients 65-74 years (n = 812). More patients achieved LDL-C targets with combination therapy vs. monotherapy in both age groups at 6 wk and in patients ≥ 75 years at 12 wk. At 12 wk, more patients ≥ 75 years achieved LDL-C targets with monotherapy vs. combination therapy. EZ/Atorva produced more favorable improvements in most lipids vs. doubling or quadrupling the atorvastatin dose in patients ≥ 75 years, generally consistent with the findings in patients 65-74 years. CONCLUSIONS: Our results extended previous findings demonstrating that ezetimibe added to a statin provided a generally well-tolerated therapeutic option for improving the lipid profile in patients 65 to 74 years and ≥ 75 years of age.

ApoA-I mimetic peptides promote pre-ß HDL formation in vivo causing remodeling of HDL and triglyceride accumulation at higher dose.

Reverse cholesterol transport promoted by HDL-apoA-I is an important mechanism of protection against atherosclerosis. We have previously identified apoA-I mimetic peptides by synthesizing analogs of the 22 amino acid apoA-I consensus sequence (apoA-I(cons)) containing non-natural aliphatic amino acids. Here we examined the effect of different aliphatic non-natural amino acids on the structure-activity relationship (SAR) of apoA-I mimetic peptides. These novel apoA-I mimetics, with long hydrocarbon chain (C(5-8)) amino acids incorporated in the amphipathic α helix of the apoA-I(cons), have the following properties: (i) they stimulate in vitro cholesterol efflux from macrophages via ABCA1; (ii) they associate with HDL and cause formation of pre-ß HDL particles when incubated with human and mouse plasma; (iii) they associate with HDL and induce pre-ß HDL formation in vivo, with a corresponding increase in ABCA1-dependent cholesterol efflux capacity ex vivo; (iv) at high dose they associate with VLDL and induce hypertriglyceridemia in mice. These results suggest our peptide design confers activities that are potentially anti-atherogenic. However a dosing regimen which maximizes their therapeutic properties while minimizing adverse effects needs to be established.

Lipid lowering for secondary prevention of cardiovascular disease in older adults.

A perceived lack of evidence for benefit and safety concerns may lead to underprescription of HMG-CoA reductase inhibitors (statins) in older adults. This article reviews clinical data regarding the effect of lipid-lowering therapies on cardiovascular outcomes in older adults with a focus on secondary prevention and safety considerations in this population. A literature search of the PubMed database (January 1984 to April 2009) was performed using search terms that included: 'aged' (MeSH heading), 'elderly', 'anticholesteremic agents', 'antilipemic agents', 'hydroxymethylglutaryl-CoA reductase inhibitors', 'cardiovascular diseases', 'randomized controlled trial', 'meta-analysis' and 'drug safety'. Results from large, randomized, controlled trials show that statin therapy lowers both all-cause and coronary heart disease mortality and reduces myocardial infarction, stroke and the need for revascularization in individuals aged ≥65 years who have a history of coronary heart disease. Given the high rate of recurrent cardiovascular events in older adults, there is substantial potential for statin treatment to provide benefits in this population. When older patients are prescribed statins, attention should be given to potential drug interactions, age-related changes in drug pharmacokinetics, adverse effects such as myopathy and risks arising from co-morbid conditions. Additional studies on the benefits and risks of lipid-lowering therapy in individuals aged ≥70 years who have no history of cardiovascular disease, and particularly in those aged ≥80 years, are needed. Other available lipid-modifying drugs - bile acid sequestrants (bile acid binding protein modulators), ezetimibe, niacin and fibrates (fibric acid derivatives) - may be required in patients who are statin-intolerant or have mixed dyslipidaemia, or in whom standard doses of statins may not be sufficient to achieve low-density lipoprotein cholesterol goals.

Safety and efficacy of ezetimibe/simvastatin combination versus atorvastatin alone in adults ≥65 years of age with hypercholesterolemia and with or at moderately high/high risk for coronary heart disease (the VYTELD study).

Higher than 80% of coronary heart disease-related mortality occurs in patients ≥65 years of age. Guidelines recommend low-density lipoprotein (LDL) cholesterol targets for these at-risk patients; however, few clinical studies have evaluated lipid-lowering strategies specifically in older adults. This multicenter, 12-week, randomized, double-blind, parallel-group trial evaluated the efficacy and safety of the usual starting dose of ezetimibe/simvastatin (10/20 mg) versus atorvastatin 10 or 20 mg and the next higher dose of ezetimibe/simvastatin (10/40 mg) versus atorvastatin 40 mg in 1,289 hypercholesterolemic patients ≥65 years of age with or without cardiovascular disease. Patients randomized to ezetimibe/simvastatin had greater percent decreases in LDL cholesterol (-54.2% for 10/20 mg vs -39.5% and -46.6% for atorvastatin 10 and 20 mg, respectively; -59.1% for 10/40 mg vs -50.8% for atorvastatin 40 mg; p <0.001 for all comparisons) and the number attaining LDL cholesterol <70 mg/dl (51.3% for 10/20 mg, 68.2% for 10/40 mg) and <100 mg/dl (83.6% for 10/20 mg; 90.3% for 10/40 mg) was significantly larger compared to those receiving atorvastatin for all prespecified dose comparisons (p <0.05 to <0.001). A significantly larger percentage of high-risk patients achieved LDL cholesterol <70 mg/dl on ezetimibe/simvastatin 10/20 mg (54.3%) versus atorvastatin 10 mg (10.9%, p <0.001) or 20 mg (28.9%, p <0.001) and ezetimibe/simvastatin 10/40 mg (69.2%) versus atorvastatin 40 mg (38.2%, p <0.001), and a significantly larger percentage of intermediate-risk patients achieved LDL cholesterol <100 mg/dl on ezetimibe/simvastatin 10/20 mg (82.1%) versus atorvastatin 10 mg (59.3%, p <0.05). Improvements in non-high-density lipoprotein cholesterol, total cholesterol, apolipoprotein B, and lipoprotein ratios were significantly greater with ezetimibe/simvastatin than atorvastatin for all comparisons (p <0.01 to <0.001). High-density lipoprotein cholesterol and triglyceride results were variable. All treatments were generally well tolerated. In conclusion, ezetimibe/simvastatin provided significantly greater improvements in key lipid parameters and higher attainment of LDL cholesterol targets than atorvastatin, with comparable tolerability.

The effects of adenosine A(1) receptor antagonism in patients with acute decompensated heart failure and worsening renal function: the REACH UP study.

BACKGROUND: Worsening renal function (WRF) portends a poor prognosis, and recent deterioration in creatinine might identify patients with elevated intrarenal adenosine in whom adenosine A(1) antagonism may improve renal hemodynamics and function. The purpose of this pilot study was to assess whether rolofylline, an adenosine A(1) antagonist (A(1)RA), would facilitate diuresis while maintaining renal function in patients with acutely decompensated heart failure (ADHF) and recent WRF. METHODS AND RESULTS: Seventy-six patients with ADHF, volume overload, and recent renal deterioration received rolofylline (30 mg, n = 36) or placebo (n = 40) for 3 days. Rolofylline did not demonstrate a beneficial effect on the primary end points of worsening heart failure or renal function after admission or death or readmission within 30 days. Similar proportions of patients receiving rolofylline (33%) and placebo (30%) were treatment failures within 30 days. However, persistent renal impairment (through Day 14) tended to be less common with rolofylline (6%) than placebo (18%). At Day 14, 11 patients receiving placebo and 13 patients receiving rolofylline had a decrease in creatinine > or = 0.3 mg/dL. There were fewer heart failure readmissions with rolofylline (n = 2) than with placebo (n = 7) through Day 60. CONCLUSIONS: The Placebo-Controlled Study of the Effects of KW-3902 Injectable Emulsion on Heart Failure Signs and Symptoms, Diuresis, Renal Function, and Clinical Outcomes in Subjects Hospitalized with Worsening Renal Function and Heart Failure Requiring Intravenous Therapy (ie, REACH UP) study did not demonstrate any clear benefit of rolofylline in patients with ADHF and worsening renal function. However, beneficial trends raise the possibility that A(1)RAs might prevent renal dysfunction in these high risk patients. To test this hypothesis, further larger studies need to evaluate the effects of adenosine A(1) antagonists in patients with progressive renal dysfunction in the face of active heart failure therapy.

Effects of the renin inhibitor MK-8141 (ACT-077825) in patients with hypertension.

The renin inhibitor MK-8141 (ACT-077825) demonstrates substantial immunoreactive active renin (ir-AR) increase (sevenfold) without a persistent plasma renin activity (PRA) decrease. The present study assessed the antihypertensive efficacy of MK-8141 in hypertensive patients. In this double-blind, placebo- and active comparator-controlled study, 195 patients with hypertension (trough sitting diastolic blood pressure ≥92 to <105 mm Hg, trough sitting systolic blood pressure <170 mm Hg, and 24-hour mean diastolic blood pressure [DBP] ≥80 mm Hg) were randomized to one of four treatments (stratified by race, black versus others): MK-8141 250 mg, MK-8141 500 mg, enalapril 20 mg, or placebo. Blood pressure was measured at trough and as 24-hour ambulatory blood pressure monitoring. The primary end point was change from baseline in 24-hour mean ambulatory DBP measured after 4 weeks. At week 4, the change from baseline in 24-hour mean (95% CI) ambulatory DBP compared with placebo was -1.6 mm Hg (-4.2, 1.1), -1.1 mm Hg (-3.9, 1.6), and -4.9 (-7.5, -2.2) for MK-8141 250 mg, MK-8141 500 mg, and enalapril 20 mg, respectively. Only mean ambulatory DBP-lowering with enalapril 20 mg was statistically significant. Enalapril, but not MK-8141, also significantly lowered 24-hour mean ambulatory systolic blood pressure (SBP) compared with placebo (-6.7 mm Hg [-10.5, -2.8]). Neither enalapril nor MK-8141 significantly lowered trough DBP and SBP compared with placebo. MK-8141 was generally well tolerated. In patients with hypertension, MK-8141 (ACT-077825) did not produce significant blood pressure-lowering efficacy despite a demonstrated effect of the drug on ir-AR, in the absence of durable PRA suppression.

Safety and efficacy of ezetimibe added to atorvastatin versus up titration of atorvastatin to 40 mg in Patients > or = 65 years of age (from the ZETia in the ELDerly [ZETELD] study).

Few clinical studies have focused on the efficacy of lipid-lowering therapies in patients > or = 65 years of age. The percentage of change from baseline in low-density lipoprotein (LDL) cholesterol and the percentage of patients achieving prespecified LDL cholesterol levels after 12 weeks of ezetimibe 10 mg plus atorvastatin versus up titration of atorvastatin were assessed in subjects > or = 65 years old with hyperlipidemia and at high risk of coronary heart disease. After stabilization of atorvastatin 10-mg therapy, 1,053 patients, > or = 65 years old, at high risk of coronary heart disease, with and without atherosclerotic vascular disease and a LDL cholesterol level that was not <70 or <100 mg/dl, respectively, were randomized to receive ezetimibe added to atorvastatin 10 mg for 12 weeks versus up titration to atorvastatin 20 mg for 6 weeks followed by up titration to atorvastatin 40 mg for an additional 6 weeks. Ezetimibe added to atorvastatin 10 mg resulted in significantly greater changes at week 6 in LDL cholesterol (p <0.001), significantly more patients with atherosclerotic vascular disease achieving a LDL cholesterol level of <70 mg/dl (p <0.001), and significantly more patients without atherosclerotic vascular disease achieving a LDL cholesterol level of <100 mg/dl (p <0.001) at weeks 6 and 12 compared to atorvastatin 20 mg or atorvastatin 40 mg. In addition, ezetimibe plus atorvastatin 10 mg resulted in significantly greater changes at week 6 in total cholesterol, triglycerides, non-high-density lipoprotein (HDL) cholesterol, apolipoprotein B (all p <0.001), and HDL cholesterol (p = 0.021) compared with atorvastatin 20 mg and significantly greater changes at week 12 in LDL cholesterol, non-HDL cholesterol, apolipoprotein A-I (p = 0.001), total cholesterol, apolipoprotein B (p <0.030), and HDL cholesterol (p <0.001) compared with atorvastatin 40 mg. Both treatments were generally well tolerated, with comparable safety profiles. In conclusion, adding ezetimibe to atorvastatin 10 mg produced significantly greater favorable changes in most lipids at 6 and 12 weeks and significantly greater attainment of prespecified LDL cholesterol levels than doubling or quadrupling the atorvastatin dose in patients > or =65 years old at high risk for coronary heart disease.

Novel potent apoA-I peptide mimetics that stimulate cholesterol efflux and pre-beta particle formation in vitro.

Reverse cholesterol transport (RCT) is believed to be the primary mechanism by which HDL and its major protein apoA-I protect against atherosclerosis. Starting from the inactive 22-amino acid peptide representing the consensus sequence of the class A amphipathic helical repeats of apoA-I, we designed novel peptides able to mobilize cholesterol from macrophages in vitro, and to stimulate the formation of 'nascent HDL' particles, with potency comparable to the entire apoA-I protein.

An apoA-I mimetic peptide facilitates off-loading cholesterol from HDL to liver cells through scavenger receptor BI.

Apolipoprotein A-I (apoA-I) mimetic peptides have been pursued as new therapeutic agents for the treatment of atherosclerosis, yet their precise mechanism responsible for atheroprotection remains unclear. Like apoA-I itself, most of these peptides are capable of stimulating cholesterol efflux from macrophages or foam cells, and some of them stimulate lecithin cholesterol acyltransferase (LCAT) activity in the reverse cholesterol transport (RCT) pathway. However, the ability of mimetic peptides to deliver cholesterol into hepatocytes (off-loading), the last step of the RCT pathway, has not been demonstrated. In this study, we compared a mimetic peptide D-4F to purified apoA-I, to address the role that mimetics play during the off-loading process. Both D-4F and apoA-I formed spherical nano-particles when reconstituted with cholesteryl ester and phospholipids. Compared to apoA-I, D-4F particles were 20 times more efficient in off-loading cholesterol to HepG2 hepatocytes with an apparent K(t) (transport) of 0.74 mug/mL. Furthermore, D-4F also facilitated cholesteryl ester offloading from HDL particles into HepG2 cells when it was pre-incubated with these HDL particles. Using an inducible HEK293 cell line, we demonstrated that these nano-particles were able to be taken up through SR-BI, a HDL selective receptor. Cholesterol uptake by HepG2 cells was completely blocked by a neutralizing monoclonal antibody against SR-BI, demonstrating that D-4F particles, similar to HDL, specifically off-loaded cholesterol through SR-BI. Overall our data provides evidence that D-4F is capable of mimicking apoA-I to form HDL-like particles, and off-loads cholesterol for catabolism and excretion, thus completing RCT.

An apoA-I mimetic peptide increases LCAT activity in mice through increasing HDL concentration.

Lecithin cholesterol acyltransferase (LCAT) plays a key role in the reverse cholesterol transport (RCT) process by converting cholesterol to cholesteryl ester to form mature HDL particles, which in turn deliver cholesterol back to the liver for excretion and catabolism. HDL levels in human plasma are negatively correlated with cardiovascular risk and HDL functions are believed to be more important in atheroprotection. This study investigates whether and how D-4F, an apolipoprotein A-I (apoA-I) mimetic peptide, influences LCAT activity in the completion of the RCT process. We demonstrated that the apparent rate constant value of the LCAT enzyme reaction gives a measure of LCAT activity and determined the effects of free metals and a reducing agent on LCAT activity, showing an inhibition hierarchy of Zn(2+)>Mg(2+)>Ca(2+) and no inhibition with beta-mercaptoethanol up to 10 mM. We reconstituted nano-disc particles using apoA-I or D-4F with phospholipids. These particles elicited good activity in vitro in the stimulation of cholesterol efflux from macrophages through the ATP-binding cassette transporter A1 (ABCA1). With these particles we studied the LCAT activity and demonstrated that D-4F did not activate LCAT in vitro. Furthermore, we have done in vivo experiments with apoE-null mice and demonstrated that D-4F (20 mg/kg body weight, once daily subcutaneously) increased LCAT activity and HDL level as well as apoA-I concentration at 72 hours post initial dosing. Finally, we have established a correlation between HDL concentration and LCAT activity in the D-4F treated mice.

Racial/ethnic disparity in kidney transplantation outcomes: influence of donor and recipient characteristics.

OBJECTIVE: The purpose of this study was to evaluate the basis for the racial/ethnic disparity in kidney allograft survival. METHODS: We conducted a retrospective study of 2130 patients who underwent kidney transplantation between January 1995 and December 2003. Patient and graft survivals were compared using Kaplan-Meier analysis. RESULTS: Black recipients were more likely than white recipients to have hepatitis C infection (24.6% vs 7.1%), current tobacco use (21.2% vs 13.1%), previous alcohol use (22.6% vs 9.7%), and past illicit drug use (13.6% vs 3.9%). Current employment was less common among blacks. Additionally, black recipients were more likely to have a prior kidney transplant (16.7% vs 11.0%) and to have a cadaver kidney donor (74% vs 56.5%). The 5-year allograft survival rate was 72% for whites and 59% for blacks (p < .01). Previous kidney transplantation, cadaveric donor, donor age, recipient employment status, and recipient tobacco use were associated with allograft survival in a Cox proportional hazard model. CONCLUSIONS: Graft survival rate in black kidney transplant recipients is significantly lower than whites, and this disparity can be partially explained by the low rate of live donors and a higher previous transplantation rate in blacks.