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1.
Clin Infect Dis ; 77(Suppl 4): S288-S294, 2023 10 16.
Article in English | MEDLINE | ID: mdl-37843120

ABSTRACT

Developing and implementing the scientific agenda of the Antibacterial Resistance Leadership Group (ARLG) by soliciting input and proposals, transforming concepts into clinical trials, conducting those trials, and translating trial data analyses into actionable information for infectious disease clinical practice is the collective role of the Scientific Leadership Center, Clinical Operations Center, Statistical and Data Management Center, and Laboratory Center of the ARLG. These activities include shepherding concept proposal applications through peer review; identifying, qualifying, training, and overseeing clinical trials sites; recommending, developing, performing, and evaluating laboratory assays in support of clinical trials; and designing and performing data collection and statistical analyses. This article describes key components involved in realizing the ARLG scientific agenda through the activities of the ARLG centers.


Subject(s)
Data Management , Leadership , Humans , Data Collection , Drug Resistance, Bacterial , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use
2.
Clin Infect Dis ; 77(Suppl 4): S321-S330, 2023 10 16.
Article in English | MEDLINE | ID: mdl-37843122

ABSTRACT

Clinical research networks conduct important studies that would not otherwise be performed by other entities. In the case of the Antibacterial Resistance Leadership Group (ARLG), such studies include diagnostic studies using master protocols, controlled phage intervention trials, and studies that evaluate treatment strategies or dynamic interventions, such as sequences of empiric and definitive therapies. However, the value of a clinical research network lies not only in the results from these important studies but in the creation of new approaches derived from collaborative thinking, carefully examining and defining the most important research questions for clinical practice, recognizing and addressing common but suboptimal approaches, and anticipating that the standard approaches of today may be insufficient for tomorrow. This results in the development and implementation of new methodologies and tools for the design, conduct, analyses, and reporting of research studies. These new methodologies directly impact the studies conducted within the network and have a broad and long-lasting impact on the field, enhancing the scientific value and efficiency of generations of research studies. This article describes innovations from the ARLG in diagnostic studies, observational studies, and clinical trials evaluating interventions for the prevention and treatment of antibiotic-resistant bacterial infections.


Subject(s)
Anti-Bacterial Agents , Leadership , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Research Design
3.
Clin Infect Dis ; 77(Suppl 4): S279-S287, 2023 10 16.
Article in English | MEDLINE | ID: mdl-37843121

ABSTRACT

In this overview, we describe important contributions from the Antibacterial Resistance Leadership Group (ARLG) to patient care, clinical trials design, and mentorship while outlining future priorities. The ARLG research agenda is focused on 3 key areas: gram-positive infections, gram-negative infections, and diagnostics. The ARLG has developed an innovative approach to clinical trials design, the desirability of outcome ranking (DOOR), which uses an ordinal measure of global outcome to assess both benefits and harms. DOOR was initially applied to observational studies to determine optimal dosing of vancomycin for methicillin-resistant Staphylcococcus aureus bacteremia and the efficacy of ceftazidime-avibactam versus colistin for the treatment of carbapenem-resistant Enterobacterales infection. DOOR is being successfully applied to the analysis of interventional trials and, in collaboration with the US Food and Drug Administration (FDA), for use in registrational trials. In the area of diagnostics, the ARLG developed Master Protocol for Evaluating Multiple Infection Diagnostics (MASTERMIND), an innovative design that allows simultaneous testing of multiple diagnostic platforms in a single study. This approach will be used to compare molecular assays for the identification of fluoroquinolone-resistant Neisseria gonorrhoeae (MASTER GC) and to compare rapid diagnostic tests for bloodstream infections. The ARLG has initiated a first-in-kind randomized, double-blind, placebo-controlled trial in participants with cystic fibrosis who are chronically colonized with Pseudomonas aeruginosa to assess the pharmacokinetics and antimicrobial activity of bacteriophage therapy. Finally, an engaged and highly trained workforce is critical for continued and future success against antimicrobial drug resistance. Thus, the ARLG has developed a robust mentoring program targeted to each stage of research training to attract and retain investigators in the field of antimicrobial resistance research.


Subject(s)
Anti-Bacterial Agents , Leadership , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Carbapenems , Ceftazidime , Colistin , Drug Resistance, Bacterial , Microbial Sensitivity Tests
4.
Clin Infect Dis ; 73(4): 730-739, 2021 08 16.
Article in English | MEDLINE | ID: mdl-33588438

ABSTRACT

In December 2019, the Antibacterial Resistance Leadership Group (ARLG) was awarded funding for another 7-year cycle to support a clinical research network on antibacterial resistance. ARLG 2.0 has 3 overarching research priorities: infections caused by antibiotic-resistant (AR) gram-negative bacteria, infections caused by AR gram-positive bacteria, and diagnostic tests to optimize use of antibiotics. To support the next generation of AR researchers, the ARLG offers 3 mentoring opportunities: the ARLG Fellowship, Early Stage Investigator seed grants, and the Trialists in Training Program. The purpose of this article is to update the scientific community on the progress made in the original funding period and to encourage submission of clinical research that addresses 1 or more of the research priority areas of ARLG 2.0.


Subject(s)
Drug Resistance, Bacterial , Leadership , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Gram-Negative Bacteria , Gram-Positive Bacteria
5.
J Nurses Prof Dev ; 33(2): 102-104, 2017.
Article in English | MEDLINE | ID: mdl-28252494

ABSTRACT

Peer review for publication is fundamental to science-based fields, and nursing is no exception. Peer review provides benefits to the reviewer and the author(s) of the reviewed work. The purpose of this article is to provide readers with an explanation of how the peer review process works, what the responsibilities of a peer reviewer are, how to get involved in peer review, and the benefits of the review process.


Subject(s)
Judgment , Nursing Research , Peer Review/methods , Publishing/standards , Staff Development , Humans , Manuscripts, Medical as Topic , Research Design
6.
Clin Infect Dis ; 64(suppl_1): S3-S7, 2017 Mar 15.
Article in English | MEDLINE | ID: mdl-28350896

ABSTRACT

The Antibacterial Resistance Leadership Group (ARLG), with funding from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health, was created in June 2013. Its mission is to develop, prioritize, and implement a clinical research agenda that addresses the public health threat of antibacterial resistance. This article reports on the progress that the ARLG has made to date in fulfilling its mission. Since inception, the ARLG has received and reviewed >70 study proposals, initiated >30 studies, executed >300 agreements, included data from >7000 subjects, published >45 manuscripts, and provided opportunities for 26 mentees. Despite this substantial progress, there remains significant work to be accomplished. This article also describes the considerable challenges that lie ahead.


Subject(s)
Anti-Bacterial Agents , Biomedical Research/organization & administration , Drug Resistance, Bacterial , Voluntary Health Agencies , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Humans , Leadership , Research Report
7.
Clin Infect Dis ; 64(suppl_1): S8-S12, 2017 Mar 15.
Article in English | MEDLINE | ID: mdl-28350897

ABSTRACT

The Leadership and Operations Center (LOC) is responsible for facilitating, coordinating, and implementing the Antibacterial Resistance Leadership Group (ARLG) scientific agenda by engaging thought leaders; soliciting research proposals; and developing the processes, tools, and infrastructure required to operationalize studies and create and sustain the ARLG network. These efforts are ongoing as new projects are developed and the network expands and grows to address the ever-changing priorities in antibacterial resistance. This article describes the innovations, accomplishments, and opportunities of the LOC since the inception of the ARLG in 2013.


Subject(s)
Biomedical Research/organization & administration , Clinical Trials as Topic , Clinical Trials as Topic/organization & administration , Clinical Trials as Topic/standards , Communicable Disease Control/organization & administration , Drug Resistance, Bacterial , Humans , Leadership , Program Development , Research Personnel , Workforce
8.
Pediatr Infect Dis J ; 34(11): 1175-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26222060

ABSTRACT

BACKGROUND: The impact of early adequate empirical antibiotic therapy on outcomes of infants in the neonatal intensive care unit (NICU) who develop Staphylococcus aureus bloodstream infections (BSI) is unknown. METHODS: Infants with S. aureus BSI discharged in 1997-2012 from 348 NICUs managed by the Pediatrix Medical Group were identified. Early adequate empirical antibiotic therapy was defined as exposure to ≥1 antibiotic with anti-staphylococcal activity on the day the first positive blood culture was obtained. All other cases were defined as inadequate empirical antibiotic therapy. We evaluated the association between inadequate empirical antibiotic therapy on outcomes controlling for gestational age, small for gestational age status, gender, discharge year, mechanical ventilation, inotropic support and use of supplemental oxygen. The primary outcome was 30-day mortality. Secondary outcomes were 7-day mortality, death before hospital discharge and length of bacteremia. RESULTS: Of the 3339 infants with S. aureus BSI, 2492 (75%) had methicillin-susceptible S. aureus (MSSA) BSI and 847 (25%) had methicillin-resistant S. aureus (MRSA) BSI. Inadequate empirical antibiotic therapy was administered in 725 (22%) cases. Inadequate empirical antibiotic therapy was associated with increased 30-day mortality (odds ratio: 2.03; 95% confidence interval: 1.08-3.82) among infants with MRSA BSI. Inadequate empirical antibiotic therapy was not associated with increases in mortality among infants with MSSA BSI. CONCLUSIONS: After controlling for confounders, inadequate empirical antibiotic therapy was associated with a modestly increased mortality at 30 days for infants with MRSA BSI.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/mortality , Staphylococcal Infections/drug therapy , Staphylococcal Infections/mortality , Staphylococcus aureus , Empirical Research , Humans , Infant , Retrospective Studies , Treatment Outcome
9.
Pediatr Infect Dis J ; 34(9): 933-6, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26065862

ABSTRACT

BACKGROUND: Escherichia coli is a common cause of bloodstream infections (BSIs) in infants and is associated with high mortality and morbidity among survivors. The clinical significance of antibiotic resistance and timing of appropriate antimicrobial therapy in this population is poorly understood. METHODS: We identified all infants with E. coli BSIs discharged from 77 neonatal intensive care units managed by the Pediatrix Medical Group in 2012. We used multivariable logistic regression to evaluate the association between 30-day mortality and ampicillin-resistant E. coli BSI, as well as the number of active empiric antimicrobial agents administered, controlling for gestational age, small-for-gestational age status, early-onset versus late-onset BSI, oxygen requirement, ventilator support and inotropic support on the day of the first positive blood culture. RESULTS: We identified 258 episodes of E. coli BSI, including 123 (48%) ampicillin-resistant isolates. Unadjusted 30-day mortality did not significantly differ between infants with ampicillin-resistant versus ampicillin-susceptible E. coli BSI [11 of 123 (9%) vs. 7 of 135 (5%); P = 0.33; adjusted odds ratio = 1.37 (95% confidence interval: 0.39, 4.77)]. Among ampicillin-resistant E. coli BSIs, 30-day mortality was not significantly lower for infants treated with at least one empiric antimicrobial active against ampicillin-resistant E. coli versus infants receiving no active empiric agent [adjusted odds ratio = 1.50 (0.07, 33.6)]. CONCLUSIONS: In this population of infants with E. coli BSI, ampicillin resistance was not associated with significantly increased mortality. Among the subset of infants with ampicillin-resistant E. coli, appropriate empirical antibiotic therapy was not associated with lower mortality.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/epidemiology , Drug Resistance, Bacterial , Escherichia coli Infections/drug therapy , Escherichia coli Infections/epidemiology , Escherichia coli/drug effects , Anti-Bacterial Agents/pharmacology , Bacteremia/microbiology , Bacteremia/mortality , Escherichia coli Infections/microbiology , Escherichia coli Infections/mortality , Female , Humans , Infant , Infant, Newborn , Male , Survival Analysis , Treatment Outcome
10.
Pediatr Infect Dis J ; 34(4): 371-5, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25760564

ABSTRACT

BACKGROUND: Coagulase-negative Staphylococcus (CoNS) is the most common cause of bloodstream infections (BSI) in hospitalized infants. CoNS BSI is most reliably treated with vancomycin; however, concerns about side effects and promoting resistance often delay empirical vancomycin therapy until culture results become available. METHODS: All infants with CoNS BSI discharged from 348 neonatal intensive care units managed by the Pediatrix Medical Group from 1997 to 2012 were identified. Empirical vancomycin therapy was defined as vancomycin exposure on the day of the first positive blood culture. Delayed vancomycin therapy was defined as vancomycin exposure 1-3 days after the first positive blood culture. We used multivariable logistic regression with random effects for site to evaluate the association between the use of empirical vancomycin therapy versus delayed vancomycin therapy and 30-day mortality, controlling for gestational age, small-for-gestational age status, postnatal age on the day of the first positive culture, oxygen requirement, ventilator support and inotropic support on the day the first positive culture was obtained. RESULTS: A total of 4364 infants with CoNS BSI were identified; 2848 (65%) were treated with empirical vancomycin. The median postnatal age at first positive culture was 14 days (interquartile range: 9, 21). Unadjusted 30-day mortality was similar for infants treated with empirical vancomycin and infants treated with delayed vancomycin therapy [166/2848 (6%) vs. 69/1516 (4%); P = 0.08]. There was no significant difference in 30-day mortality on multivariable analysis [odds ratio: 1.14 (0.84, 1.56)]. The median duration of bacteremia was 1 day longer for infants with delayed vancomycin therapy [4 days (interquartile range: 2, 6) vs. 3 days (2, 5); P < 0.0001]. CONCLUSIONS: The median duration of bacteremia was 1 day longer in infants with CoNS BSI who received delayed vancomycin therapy. Despite this finding, empirical vancomycin therapy for CoNS BSI was not associated with improved mortality.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/mortality , Staphylococcal Infections/drug therapy , Staphylococcal Infections/mortality , Staphylococcus/isolation & purification , Vancomycin/administration & dosage , Bacteremia/microbiology , Coagulase/analysis , Female , Humans , Infant , Infant, Newborn , Intensive Care Units, Neonatal , Male , Secondary Prevention , Staphylococcal Infections/microbiology , Staphylococcus/drug effects , Staphylococcus/enzymology , Survival Analysis , Time Factors , Treatment Outcome
11.
J Nurses Prof Dev ; 31(1): 15-20, 2015.
Article in English | MEDLINE | ID: mdl-25608092

ABSTRACT

The purpose of this project was to describe the benefits and components of successful nurse residency programs, as well as gain insight into the perceptions of staff nurses, nurse educators, and nurse leaders regarding value, feasibility, and barriers to implementing nurse residency programs in acute care settings. This study has important implications for implementing an effective residency program.


Subject(s)
Attitude of Health Personnel , Education, Nursing, Graduate , Internship, Nonmedical/methods , Nursing Staff, Hospital , Female , Humans , Nursing Administration Research , Nursing Staff, Hospital/psychology , Personnel Turnover , United States
12.
Clin Infect Dis ; 58(11): 1571-6, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24610430

ABSTRACT

Funded by the National Institute of Allergy and Infectious Diseases, the Antibacterial Resistance Leadership Group (ARLG) is tasked with developing a clinical research agenda and conducting clinical studies to address the growing public health threat of antibacterial resistance. The ARLG has identified 4 high-priority areas of research: infections caused by gram-negative bacteria, infections caused by gram-positive bacteria, antimicrobial stewardship and infection prevention, and diagnostics. The ARLG will be accepting proposals from the scientific community for clinical research that addresses 1 or more of these high-priority areas. These studies should have the potential to transform medical practice and be unlikely to occur without ARLG support. The purpose of this article is to make interested parties aware of clinical research opportunities made available by ARLG and to encourage submission of clinical research proposals that address the problem of antibacterial resistance.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Bacterial Infections/microbiology , Biomedical Research/trends , Capital Financing , Drug Resistance, Bacterial , Drug Utilization/standards , Anti-Bacterial Agents/pharmacology , Humans , Leadership , National Institute of Allergy and Infectious Diseases (U.S.) , United States
13.
J Forensic Sci ; 58(1): 130-3, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23033883

ABSTRACT

Luminol, Bluestar(®), and Hemascein(®) were tested to compare detection sensitivities to latent blood. Untreated, EDTA-treated human blood, and a catalytically similar blood substitute were diluted (neat to 1:1,000,000) and pipetted onto a variety of substrates. Luminol and Bluestar(®) performed similarly on all surfaces and fabrics. Hemascein(®) yielded poor results on wood surfaces, but performed well in the detection of latent blood on fabrics. Results from untreated, EDTA-treated, and synthetic blood results indicate that EDTA-treated blood is similar or slightly less sensitive than untreated blood at all dilutions and on all substrates, and the synthetic blood is less sensitive than real blood, but consistent in detection threshold and thus is useful as a training aid. Additionally, some foods and household chemicals that have previously been shown to cross-react were tested with Bluestar(®), Hemascein(®), and luminol. Hemascein(®) cross-reacted with many substances, while both luminol reagents were more discriminating.


Subject(s)
Blood Stains , Indicators and Reagents , Anticoagulants , Edetic Acid , Forensic Medicine , Humans , Luminol , Specimen Handling , Surface Properties , Textiles
14.
J Parasitol ; 98(1): 93-102, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21790366

ABSTRACT

Prothonotary warbler (Protonotaria citrea) has shown a long-term decline in abundance in the United States. As a long-range migrant, these warblers are exposed to parasites in both tropical and temperate regions. The focus of this study was to use molecular techniques to examine the temporal prevalence patterns of heamosopridian parasites Plasmodium and Haemoproteus in breeding prothonotary warblers. The prevalence (presence or absence) of Plasmodium and Haemoproteus species was assayed using primer sets for the cytochrome b gene of the mitochondrial DNA. Blood samples were obtained from 187 adult prothonotary warblers collected at 3 central Virginia, U.S.A., breeding sites. The relationship between haemosporidian parasite infections and reproductive success also was examined. We found that 71% of captured prothonotary warblers were infected with haemosporidian parasites, specifically, with 36% prevalence for Haemoproteus spp. and 44% prevalence for Plasmodium spp., during the 2008 breeding season; for both parasites, prevalence increased throughout the season. We found significant variation in haemosporidian parasite prevalence across the breeding season that was strongly site specific. Conversely, we found no significant effects of haemosporidian parasite infections on the reproductive success of prothonotary warblers. This is in sharp contrast to recent reports suggesting considerable effects of these parasites on the reproductive success of wild birds.


Subject(s)
Haemosporida/isolation & purification , Malaria, Avian/epidemiology , Plasmodium/isolation & purification , Protozoan Infections, Animal/epidemiology , Songbirds/parasitology , Analysis of Variance , Animals , Bird Diseases/epidemiology , Bird Diseases/parasitology , Clutch Size , Female , Linear Models , Logistic Models , Malaria, Avian/parasitology , Male , Odds Ratio , Prevalence , Protozoan Infections, Animal/parasitology , Songbirds/anatomy & histology , Songbirds/physiology
16.
Am J Physiol Heart Circ Physiol ; 284(2): H683-90, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12388218

ABSTRACT

Recent studies suggest a role for phospholamban phosphorylation during ischemia and reperfusion. The role of phospholamban in ischemia was studied by subjecting hearts from male and female wild-type (MWT/FWT) and phospholamban-knockout (MKO/FKO) mice to 20 min of ischemia-40 min of reperfusion while (31)P NMR spectra were acquired. ATP and pH values fell lower during ischemia, and postischemic contractility was less, in MKO and FKO versus WT hearts. After shorter ischemia (15 min), recoveries of contraction, ATP, and pH were greater in FKO than MKO hearts. To examine the role of nitric oxide (NO) synthases (NOS) in the protection in FKO versus MKO hearts, we utilized 1 microM l-NAME, a NOS inhibitor, or 100 microM S-nitroso-N-acetylpenicillamine (SNAP), an NO donor. Recoveries of function, ATP, and pH were less in l-NAME-treated FKO than untreated FKO hearts and greater in SNAP-treated MKO than untreated MKO hearts. In conclusion, phospholamban ablation increased ischemic injury in both males and females; however, female hearts were less susceptible than male hearts. Protection in females was decreased by a NOS inhibitor and mimicked in males by an NO donor, implying that protection was NOS mediated.


Subject(s)
Calcium-Binding Proteins/metabolism , Cardiotonic Agents/metabolism , Myocardial Ischemia/physiopathology , Nitric Oxide/metabolism , Sex Characteristics , Animals , Calcium-Binding Proteins/genetics , Enzyme Inhibitors/pharmacology , Female , Hydrogen-Ion Concentration , Intracellular Membranes/metabolism , Male , Mice , Mice, Knockout/genetics , Myocardial Contraction/drug effects , Myocardial Contraction/physiology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Phosphates/metabolism , Reference Values , S-Nitroso-N-Acetylpenicillamine/pharmacology
17.
Ann N Y Acad Sci ; 976: 421-30, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12502591

ABSTRACT

Cytosolic calcium increases to approximately 3 micro M after 15 min of global ischemia. Manipulations that attenuate this increase in cytosolic Ca(2+) reduce myocyte death and dysfunction. The increase in cytosolic Ca(2+) during ischemia is dependent on an increase in intracellular Na(+), suggesting a role for Na/Ca exchange. Typical ischemic values for ionized intra- and extracellular Na(+), Ca(2+), and membrane potential are consistent with the Na/Ca exchanger operating near equilibrium during ischemia. Studies were undertaken using hearts from mice that overexpress the Na/Ca exchanger to determine if Na/Ca exchanger overexpression enhances or reduces ischemic injury. These studies suggest that overexpression of the Na/Ca exchanger enhances injury in males, but females are protected by a gender-related mechanism.


Subject(s)
Calcium/metabolism , Ischemia/physiopathology , Reperfusion Injury/physiopathology , Reperfusion , Sodium-Calcium Exchanger/physiology , Sodium/metabolism , Animals , Biological Transport , Humans , Kinetics , Membrane Potentials
18.
Am J Physiol Heart Circ Physiol ; 283(4): H1562-8, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12234810

ABSTRACT

To determine whether A(3) adenosine receptor (A(3)AR) signaling modulates myocardial function, energetics, and cardioprotection, hearts from wild-type and A(3)AR-overexpressor mice were subjected to 20-min ischemia and 40-min reperfusion while (31)P NMR spectra were acquired. Basal heart rate and left ventricular developed pressure (LVDP) were lower in A(3)AR-overexpressor hearts than wild-type hearts. Ischemic ATP depletion was delayed and postischemic recoveries of contractile function, ATP, and phosphocreatine were greater in A(3)AR-hearts. To determine the role of depressed heart rate and to confirm A(3)AR-specific signaling, hearts were paced at 480 beats/min with or without 60 nmol/l MRS-1220 (A(3)AR-specific inhibitor) and then subjected to ischemia-reperfusion. LVDP was similar in paced A(3)AR-overexpressor and paced wild-type hearts. Differences in ischemic ATP depletion and postischemic contractile and energetic dysfunction remained in paced A(3)AR-overexpressor hearts versus paced wild-type hearts but were abolished by MRS-1220. In summary, A(3)AR overexpression decreased basal heart rate and contractility, preserved ischemic ATP, and decreased postischemic dysfunction. Pacing abolished the decreased contractility but not the ATP preservation or cardioprotection. Therefore, A(3)AR overexpression results in cardioprotection via a specific A(3)AR effect, possibly involving preservation of ATP during ischemia.


Subject(s)
Energy Metabolism/physiology , Heart Rate/physiology , Myocardial Ischemia/physiopathology , Receptors, Purinergic P1/genetics , Receptors, Purinergic P1/metabolism , Adenosine Triphosphate/metabolism , Animals , Gene Expression/physiology , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy , Mice , Mice, Transgenic , Myocardial Contraction/physiology , Myocardial Ischemia/metabolism , Myocardium/metabolism , Phosphocreatine/metabolism , Receptor, Adenosine A3 , Recovery of Function/physiology
19.
Am J Physiol Heart Circ Physiol ; 283(2): H481-9, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12124192

ABSTRACT

To compare ischemia-reperfusion injury in males versus females under hypercontractile conditions, perfused hearts from 129J mice pretreated with 3 mmol/l Ca(2+) or 10(-8) mol/l isoproterenol +/- 10(-6) mol/l N(omega)-nitro-L-arginine methyl ester (L-NAME) were subjected to 20 min of ischemia and 40 min of reperfusion while (31)P NMR spectra were acquired. Basal contractility increased equivalently in female versus male hearts with isoproterenol- or Ca(2+) treatment. Injury was equivalent in untreated male versus female hearts but was greater in isoproterenol or Ca(2+)-treated male than female hearts, as indicated by lower postischemic contractile function, ATP, and PCr. Endothelial nitric oxide (NO) synthase (eNOS) expression was higher in female than male hearts, neuronal NOS (nNOS) did not differ, and inducible NOS (iNOS) was undetectable. Ischemic NO production was higher in female than male hearts, and L-NAME increased injury in female isoproterenol-treated hearts. In summary, isoproterenol or high Ca(2+) pretreatment increased ischemia-reperfusion injury in males more than females. eNOS expression and NO production were higher in female than male hearts, and L-NAME blocked female protection. Females were therefore protected from the detrimental effects of adrenergic stimulation and Ca(2+) loading via a NOS-mediated mechanism.


Subject(s)
Adrenergic beta-Agonists/pharmacology , Calcium/metabolism , Isoproterenol/pharmacology , Myocardial Ischemia/etiology , Myocardial Reperfusion Injury/etiology , Sex Characteristics , Adrenergic beta-Agonists/administration & dosage , Animals , Calcium/administration & dosage , Calcium/pharmacology , Disease Susceptibility , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Female , Hydrogen-Ion Concentration , In Vitro Techniques , Intracellular Fluid/metabolism , Isoproterenol/administration & dosage , Male , Mice , Mice, Inbred Strains , Myocardial Contraction/drug effects , Myocardial Ischemia/physiopathology , Myocardial Reperfusion Injury/physiopathology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/metabolism , Phosphates/metabolism
20.
J Mol Cell Cardiol ; 34(3): 361-7, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11945027

ABSTRACT

PKC epsilon is a PKC isoform that translocates during preconditioning and may mediate cardioprotection. To investigate whether PKC epsilon activation is cardioprotective, Langendorff-perfused hearts from wild-type (WT) mice and from mice expressing constitutively active mutant PKC epsilon were subjected to 20 min ischemia and 40 min reperfusion while(31)P NMR spectra were acquired. Pre-ischemic glycogen levels were similar in WT and PKC epsilon hearts. During ischemia, ATP fell less in PKC epsilon than in WT hearts. Ischemic intracellular pH, however, was similar in WT and PKC epsilon hearts. During reperfusion, recovery of contractile function and ATP were greater in PKC epsilon than WT hearts. In conclusion, expression of activated PKC epsilon protected hearts from post-ischemic energetic and contractile dysfunction, consistent with the proposed cardioprotective role of PKC epsilon. Protection occurred in the PKC epsilon hearts without attenuation of ischemic H(+) production, implying that, at least in this ischemic model, reduced acidification during ischemia is not necessary for cardioprotection.


Subject(s)
Isoenzymes/metabolism , Myocardial Ischemia/metabolism , Protein Kinase C/metabolism , Protons , Adenosine Triphosphate/metabolism , Animals , Enzyme Activation , Glycogen/metabolism , Heart Rate , Hydrogen-Ion Concentration , Isoenzymes/genetics , Mice , Mice, Transgenic , Myocardial Contraction , Myocardial Ischemia/enzymology , Myocardial Ischemia/genetics , Myocardial Ischemia/pathology , Nuclear Magnetic Resonance, Biomolecular , Phosphates/metabolism , Protein Kinase C/genetics , Protein Kinase C-epsilon , Time Factors
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