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Levin S, Aronsky D, Hemphill R, Han J, Slagle J, France DJ. Shifting Toward Balance: Measuring the Distribution of Workload Among Emergency Physician Teams. Ann Emerg Med 2007; 50:419-23. [PMID: 17559969 DOI: 10.1016/j.annemergmed.2007.04.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 03/14/2007] [Accepted: 04/06/2007] [Indexed: 11/28/2022]
Abstract
STUDY OBJECTIVE The objective of this investigation is to determine time-dependent workload patterns for emergency department (ED) physician teams across work shifts. A secondary aim was to demonstrate how ED demand patterns and the timing of shift changes influence the balance of workload among a physician team. METHODS Operational measurements of an adult ED were collected from a clinical information system to characterize physician workload patterns during all current work shifts. Plots of patient load versus time were developed for each physician shift, in which patient load was defined as the number of patients a physician simultaneously managed at a point in time. Patient-load curves for each shift were superimposed during 24 hours to display how patient load was distributed among a team of physicians. RESULTS Resident shift changes during daily peak occupancy periods caused patient load imbalances so that residents on a particular shift consistently managed a disproportionate number of patients (mean 9.4 patients; 95% confidence interval [CI] 6.7 to 12.1 patients) compared with other residents on duty (mean 3.4 patients; 95% CI 2.1 to 4.7 patients). CONCLUSION Physician patient load patterns and ED demand patterns should be taken into consideration when physician shift times are scheduled so that patient load may be balanced among a team. Real-time monitoring of physician patient load may reduce stress and prevent physicians from exceeding their safe capacity for workload.
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France DJ, Levin S. System complexity as a measure of safe capacity for the emergency department. Acad Emerg Med 2006; 13:1212-9. [PMID: 16807398 DOI: 10.1197/j.aem.2006.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVES System complexity is introduced as a new measure of system state for the emergency department (ED). In its original form, the measure quantifies the uncertainty of demands on system resources. For application in the ED, the measure is being modified to quantify both workload and uncertainty to produce a single integrated measure of system state. METHODS Complexity is quantified using an information-theoretic or entropic approach developed in manufacturing and operations research. In its original form, complexity is calculated on the basis of four system parameters: 1) the number of resources (clinicians and processing entities such as radiology and laboratory systems), 2) the number of possible work states for each resource, 3) the probability that a resource is in a particular work state, and 4) the probability of queue changes (i.e., where a queue is defined by the number of patients or patient orders being managed by a resource) during a specified time period. RESULTS An example is presented to demonstrate how complexity is calculated and interpreted for a simple system composed of three resources (i.e., emergency physicians) managing varying patient loads. The example shows that variation in physician work states and patient queues produces different scores of complexity for each physician. It also illustrates how complexity and workload differ. CONCLUSIONS System complexity is a viable and technically feasible measurement for monitoring and managing surge capacity in the ED.
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Erdmann D, Levin S. Delayed Reverse Sural Flap for Staged Reconstruction of the Foot and Lower Leg. Plast Reconstr Surg 2006; 118:571-2. [PMID: 16874261 DOI: 10.1097/01.prs.0000229191.50484.06] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
Therapy related alterations to the thyroid gland are associated with more or less specific morphological changes. The therapy (thyrostatic drugs, radio-iodine) may be administered for the treatment of thyroid dysfunction (hyperthyroidism), or the thyroid gland is involved during or after the treatment (irradiation, various drugs) of primarily non-thyroid related diseases. The present review summarizes the most important morphological changes related to therapy.
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Levin S, France DJ, Hemphill R, Jones I, Chen KY, Rickard D, Makowski R, Aronsky D. Tracking workload in the emergency department. HUMAN FACTORS 2006; 48:526-39. [PMID: 17063967 DOI: 10.1518/001872006778606903] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
OBJECTIVE The primary objective of this study was to create a methodology for measuring transient levels of physician workload in a live emergency department (ED) environment. BACKGROUND Characterizing, defining, and measuring aspects of this interrupt-driven work environment represent the preliminary steps in addressing impending issues concerning ED overcrowding, efficiency, and patient and provider safety. METHODS A time-motion task analysis was conducted. Twenty emergency medicine (EM) physicians were observed for 180-min intervals in an ED of an academic medical center. Near continuous workload measures were developed and used to track changing workload levels in time. These measures were taken from subjective, objective, and physiological perspectives. The NASA-Task Load Index was administered to each physician after observational sessions to measure subjective workload. Physiological measurements were taken throughout the duration of the observation to measure stress response. Additional information concerning physicians' patient quantity and patient complexity was extracted from the ED information system. RESULTS Graphical workload profiles were created by combining observational and subjective data with system state data. Methodologies behind the creation of workload profiles are discussed, the workload profiles are compared, and quantitative and qualitative analyses are conducted. CONCLUSION Using human factors methods to measure workload in a setting such as the ED proves to be challenging but has relevant application in improving the efficiency and safety of EM. APPLICATION Techniques implemented in this research are applicable in managing ED staff and real-time monitoring of physician workload.
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Levin S, France D, Mayberry RS, Stonemetz S, Jones I, Aronsky D. The effects of computerized triage on nurse work behavior. AMIA ... ANNUAL SYMPOSIUM PROCEEDINGS. AMIA SYMPOSIUM 2006; 2006:1005. [PMID: 17238624 PMCID: PMC1839482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The complex work processes and communication patterns exhibited in Emergency Medicine may be effectively managed through the use of information technology. These tools must be evaluated within the work environment to understand their effects on work flow, information flow, and patient safety. In this study the efficiency of the Emergency Department triage process was evaluated pre- and post- implementation of a computerized triage system. Time-and-motion analyses revealed no changes in triage documentation time; however, the duration of interruptions and the number of tasks decreased significantly.
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France DJ, Levin S, Hemphill R, Chen K, Rickard D, Makowski R, Jones I, Aronsky D. Emergency physicians’ behaviors and workload in the presence of an electronic whiteboard. Int J Med Inform 2005; 74:827-37. [PMID: 16043391 DOI: 10.1016/j.ijmedinf.2005.03.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 03/22/2005] [Indexed: 11/29/2022]
Abstract
BACKGROUND As the demands on the emergency medicine (EM) system continue to increase, improvements in the organization of work and the access to timely clinical and system information will be required for providers to manage their workload in a safe and efficient manner. Information technology (IT) solutions are beginning to find their place in the emergency department (ED) and it is time to begin understanding how these systems are effecting physician behavior, communication and workload. METHODS The study used a time-in-motion, primary task analyses to study faculty and resident physician behavior in the presence of an electronic whiteboard. The NASA-Task Load Index (TLX) was used to measure subjective workload and the underlying dimensions of workload at the end of each physician observation. Work, communication and workload were characterized using descriptive statistics and compared using Mann-Whitney U-tests. RESULTS Physicians in our study performed more tasks and were interrupted less than physicians studied previously in conventional EDs. Interruptions interrupted direct patient care tasks less than other clinical activities. Temporary interruptions appear to be a major source of inefficiency in the ED, and likely a major threat to patient safety. Face-to-face interruptions persist even in the presence of advanced IT systems, such as the electronic whiteboard. Faculty physicians exhibited lower workload scores than resident physicians. Frustration was a significant contributing factor to workload in resident physicians. All physicians ranked temporal demands and mental demands as major contributing factors to workload. CONCLUSION The results indicate that the electronic whiteboard improves the efficiency of work and communication in the ED. IT solutions may have great utility in improving provider situational awareness and distributing workload among ED providers. The results also demonstrate that IT solutions alone will not solve all problems in the ED. IT solutions will probably be most effective in improving efficiency and safety outcomes when paired with human-based interventions, such as crew resource management. Future studies must investigate team interaction, workload and situational awareness, and the association of these factors to patient and provider outcomes.
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Klein JD, Levin S. Prevalence and Fluconazole Susceptibility of CandidaSpecies Recovered From the Oropharynx of Healthcare Workers (HCWs) and Non-HCWs. Infect Control Hosp Epidemiol 2004; 25:352-4. [PMID: 15108737 DOI: 10.1086/502406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractWe compared oropharyngeal cultures and fluconazole susceptibility forCandidain 100 healthcare workers (HCWs) and 100 non-HCWs. Isolates were identified using standard microbiological methods. Susceptibility was determined by Etest and microliter method. There was no significant difference in prevalence or species of oropharyngealCandidabetween HCWs and non-HCWs. Fluconazole resistance was infrequent.
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Volovitz B, Friedman N, Levin S, Kertes J, Iny-Cordova S, Nussinovitch M, Meytes D, Kokia E. Increasing asthma awareness among physicians: impact on patient management and satisfaction. J Asthma 2004; 40:901-8. [PMID: 14736090 DOI: 10.1081/jas-120023582] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Our objective was to investigate the impact of increased asthma awareness among primary care physicians on the asthma control and satisfaction of their patients. Physicians attended an asthma education session with emphasis on patient-physician partnership followed by 4 month monitored follow-up of patients aged 5-44 years with mild to moderate asthma. Findings were compared with a group of patients whose physician attended the session but did not participate in the follow-up and two other control groups. The study included pediatricians and general practitioners of Maccabi Healthcare Services and their patients. Asthma symptoms were rated by patients and physicians. Data on drug prescription and use were derived from the Maccabi central database. Patient response and satisfaction and physician satisfaction were evaluated by telephone interviews. Mean asthma symptom score improved from 2.0 to 1.1 in the study group of patients (p < 0.001). The use of reliever drugs decreased concomitantly with a rise in controller drugs in all patients. An improvement in asthma status was reported by 64% of the study patients and 39% of non-participating patients (p = 0.007). Fifty-eight percent of the patients rated their competence to deal with asthma as high before the intervention compared to 62% of the participating and 55% of the non-participating patients after the intervention (p = 0.002). Most physicians claimed that simply increasing their awareness on asthma led to beneficial results in their patients. Physician education followed by monitored follow-up enhanced asthma control and patient satisfaction. Nevertheless, physician education alone appears to have a significant isolated impact on asthma control.
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Pons J, Rocon E, Ceres R, Reynaerts D, Saro B, Levin S, Van Moorleghem W. The MANUS-HAND Dextrous Robotics Upper Limb Prosthesis: Mechanical and Manipulation Aspects. Auton Robots 2004. [DOI: 10.1023/b:auro.0000016862.38337.f1] [Citation(s) in RCA: 211] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Fowler VG, Kaye KS, Simel DL, Cabell CH, McClachlan D, Smith PK, Levin S, Sexton DJ, Reller LB, Corey GR, Oddone EZ. Staphylococcus aureus bacteremia after median sternotomy: clinical utility of blood culture results in the identification of postoperative mediastinitis. Circulation 2003; 108:73-8. [PMID: 12821547 DOI: 10.1161/01.cir.0000079105.65762.db] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Mediastinitis is a complication of coronary artery bypass graft surgery (CABG) that can be difficult to diagnose. This study evaluated the utility of blood culture results in identifying patients with mediastinitis. METHODS AND RESULTS All unique patients undergoing CABG at our institution over a 60-month study period (n=5500) and all blood cultures performed on these patients <or=90 days after CABG were identified. Mediastinitis was identified by prospective active infection control surveillance. Eight hundred fifty-five (15.5%) patients had >or=1 blood culture drawn within 90 days of CABG. Mediastinitis occurred in 46 of 60 (76.7%) patients with blood cultures positive for Staphylococcus aureus, 15 of 126 (11.9%) patients with blood cultures positive for other pathogens, 37 of 669 (5.5%) patients with blood cultures with no growth, and 44 of 4645 (0.9%) patients with no blood cultures obtained. The isolation of S aureus from even 1 blood culture drawn after <or=90 days of CABG was strongly associated with mediastinitis (likelihood ratio [LR], 25; 95% CI, 14.7 to 44.4). Bacteremia attributable to other organisms did not alter pretest suspicion for mediastinitis (LR, 1.0; 95% CI, 0.6 to 1.7). Patients with negative blood cultures were less likely to have mediastinitis (LR, 0.45; 95% CI, 0.35 to 0.58). The association between S aureus bacteremia and mediastinitis remained highly significant when all unique patients undergoing CABG were analyzed in a logistic regression model and when a case-control analysis was used to evaluate patients with >or=1 blood culture obtained after CABG. CONCLUSIONS Among patients with blood cultures drawn after CABG, S aureus bacteremia strongly suggests the presence of mediastinitis.
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Cook CS, Zhang L, Ames GB, Fischer J, Zhang J, Levin S. Single- and repeated-dose pharmacokinetics of eplerenone, a selective aldosterone receptor blocker, in rats. Xenobiotica 2003; 33:305-21. [PMID: 12637247 DOI: 10.1080/0049825021000049277] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The pharmacokinetics of eplerenone (EP) were examined in rats following single or repeated dosing with (14)C-labelled or unlabelled EP to characterize absorption, metabolism and excretion. Rates of EP metabolism and cytochrome P450 activities were determined in vitro after repeated dose administration of EP. 2. Following a single i.v. dose (15 mg kg(-1)), the elimination half-life of EP was 0.80 and 1.14 h in male and female rats, respectively. Plasma clearances (CL) of EP were 1.62 and 1.20 l kg(-1) h(-1) in males and females, respectively. Following a single oral dose (15 mg kg(-1)), C(max) and T(max) of EP were 1.71 micro g ml(-1) and 0.5 h in male rats. The corresponding values in female rats were 3.54 micro g ml(-1) and 1.0 h. The systemic availability of EP was 25.6% in male rats and 66.4% in female rats, demonstrating sex differences in the pharmacokinetics of EP. 3. In the 8-day study, the AUC(0-24h)'s of total EP (closed lactone ring form plus open form) following 100 and 200 mg kg(-1) oral doses were approximately half those on day 1 in male rats. After repeated dosing for 13 weeks, the pharmacokinetics of total EP did not change with study duration at the 20 mg kg(-1) dose in both males and females. However, at the 100 mg kg(-1) dose, AUC(0-24h)'s were notably reduced on day 24 but progressively increased on subsequent days to approximate day 1 levels by day 86 in both sexes. At the 500 mg kg(-1) dose, the AUCs on day 86 remained lower than those on day 1. Reductions in AUCs on days 8 and 24 appeared to be the result of metabolism induction. 4. EP was extensively metabolized in male rats and most faecal and urinary radioactivity was in the form of metabolites. In female rats, the vast majority of urine and faecal radioactivity was associated with total EP. Thus, the sex difference in the pharmakokinetics of EP was due to more extensive metabolism in male rats. 5. The major metabolite in the rat was 6beta-OH EP. EP 6beta-hydroxylase activity was well correlated with testosterone 6beta-hydroxylase activity, indicating that EP metabolism to 6beta-OH EP was mediated primarily by CYP3A in the rat. 6. After repeated dose administration, EP increased 6beta-hydroxylase activities of testosterone and EP itself in a dose-dependent manner in both male and female rats, indicating that EP was a CYP3A inducer in the rat. There appeared to be no effects on activities of CYP1A1, 2B and 2E1.
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Martin MW, Levin S, McKenzie TL, DeLouise AC. DYNAMOTION. Med Sci Sports Exerc 2002. [DOI: 10.1097/00005768-200205001-01558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Godukhin O, Savin A, Kalemenev S, Levin S. Neuronal hyperexcitability induced by repeated brief episodes of hypoxia in rat hippocampal slices: involvement of ionotropic glutamate receptors and L-type Ca(2+) channels. Neuropharmacology 2002; 42:459-66. [PMID: 11955517 DOI: 10.1016/s0028-3908(02)00005-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Repeated exposures of rat hippocampal slices to short episodes of hypoxia induce a sustained decrease in the threshold of the development of stimulus-evoked epileptiform discharges in CA1 pyramidal neurons. We have previously demonstrated that the K(+)(o)-induced hyperexcitability required functional L-type voltage-dependent Ca(2+) channels and NMDA-receptors, but was independent of AMPA/kainate-receptor activation. As hypoxia/ischaemia can lead to increased K(+)(o), the epileptiform activity observed after exposure to these challenges could also result from high K(+)(o). The purpose of this study was: (i) to determine whether ionotropic glutamate receptors and L-type Ca(2+) channels are involved in the development of epileptiform activity induced by repeated exposures of hippocampal slices to hypoxia; and (ii) to compare the properties of hypoxia- and high K(+)(o)-induced hyperexcitability. Population spike of presynaptic fibres with field excitatory postsynaptic potential from the stratum radiatum, and population spike of CA1 pyramidal neurons from the stratum pyramidale, were recorded simultaneously in the CA1 area of rat hippocampal slices in response to electrical stimulation of the Schaffer collateral/commissural fibres. Repeated, brief hypoxic episodes induced a sustained decrease in the threshold for development of evoked epileptiform discharges that was associated with long-term potentiation of the CA3-CA1 synapses, but without EPSP-spike potentiation (i.e. in contrast to high K(+)(o)-induced hyperexcitability). The selective antagonist of NMDA receptors, D-APV (25 microM), and the selective blocker of L-type Ca(2+) channels, nifedipine (10 microM) depressed the development of hypoxia-induced hyperexcitability. However, in contrast to high K(+)(o)-induced hyperexcitability, hypoxia-induced hyperexcitability was also blocked by the AMPA/kainite-receptor antagonist, CNQX (5 microM). The present findings confirm that repeated, brief episodes of hypoxia, like exposure to high extracellular K(+), can induce a pro-epileptic state in the CA1 neuronal network, but that the mechanisms leading to hyperexcitability are different for the two stimuli.
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Bolton SJ, Janssen M, Thorne R, Levin S, Klein M, Gulkis S, Bastian T, Sault R, Elachi C, Hofstadter M, Bunker A, Dulk G, Gudim E, Hamilton G, Johnson WTK, Leblanc Y, Liepack O, McLeod R, Roller J, Roth L, West R. Ultra-relativistic electrons in Jupiter's radiation belts. Nature 2002; 415:987-91. [PMID: 11875557 DOI: 10.1038/415987a] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.
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Levin S, Welch VLL, Bell RA, Casper ML. Geographic variation in cardiovascular disease risk factors among American Indians and comparisons with the corresponding state populations. ETHNICITY & HEALTH 2002; 7:57-67. [PMID: 12119066 DOI: 10.1080/13557850220146993] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVES (1) To compare the prevalence of self-reported CVD, diabetes, hypertension, fair/poor perceived health status, and current tobacco use from three surveys of American Indians - two in the Southeast (Catawba Diabetes and Health Survey [CDHS] and Lumbee Diabetes and Health Survey [LDHS]) and one in the upper Midwest (Inter-Tribal Heart Project [ITHP]). (2) To compare the prevalence estimates from the CDHS, LDHS, ITHP with those for the corresponding state populations (South Carolina, North Carolina, Minnesota and Wisconsin, respectively) derived from the Behavioral Risk Factor Surveillance System (BRFSS). METHODS Pearson's Chi-square analyses were used to detect statistically significant differences in the age-adjusted prevalence estimates across the study populations. RESULTS Among these three populations of American Indians, the ITHP participants had the highest prevalence estimates of diabetes (20.1%) and current cigarette smoking (62.8%). The CDHS participants had the highest prevalence estimate of fair/poor perceived health status (32.0%). The LDHS participants had the highest prevalence estimate of chewing tobacco use (14.0%), and the lowest prevalence of CVD. The prevalence estimates of self-reported diabetes were dramatically higher among American Indian participants in the ITHP (20.1%) and CDHS (14.9%) than among participants in the corresponding state BRFSS (5.8% MN and WI and 6.6% SC), as were the estimates for hypertension. CONCLUSION The substantial variations in prevalence of CVD and its risk factors among Tribal Nations suggests that distinct cultural norms, historic conditions, and important health issues of each American Indian community must be recognized and incorporated into all health promotion programs and policies.
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Delyani JA, Rocha R, Cook CS, Tobert DS, Levin S, Roniker B, Workman DL, Sing YL, Whelihan B. Eplerenone: a selective aldosterone receptor antagonist (SARA). CARDIOVASCULAR DRUG REVIEWS 2002; 19:185-200. [PMID: 11607037 DOI: 10.1111/j.1527-3466.2001.tb00064.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aldosterone, the final product of the renin-angiotensin-aldosterone system (RAAS), is a mineralocorticoid hormone that classically acts, via the mineralocorticoid (aldosterone) receptor, on epithelia of the kidneys, colon, and sweat glands to maintain electrolyte homeostasis. Aldosterone has also been shown to act at nonepithelial sites where it can contribute to cardiovascular disease such as hypertension, stroke, malignant nephrosclerosis, cardiac fibrosis, ventricular hypertrophy, and myocardial necrosis. Although angiotensin-converting enzyme (ACE) inhibitors and angiotensin type 1 (AT(1)) receptor antagonists act to suppress the RAAS, these agents do not adequately control plasma aldosterone levels--a phenomenon termed "aldosterone synthesis escape." Spironolactone, a nonselective aldosterone receptor antagonist, is an effective agent to suppress the actions of aldosterone; its use is, however, associated with progestational and antiandrogenic side effects due to its promiscuous binding to other steroid receptors. For these reasons, eplerenone--the first agent of a new class of drugs known as the selective aldosterone receptor antagonists (SARAs)--is under development. In rodent models, eplerenone provides marked protection against vascular injury in the kidney and heart. In phase II clinical trials, eplerenone demonstrates 24-h control of blood pressure with once or twice daily dosing, and is safe and well tolerated in patients with heart failure when given with standard of care agents. Pharmacokinetic studies reveal that eplerenone has good bioavailability with low protein binding, good plasma exposure, and is highly metabolized to inactive metabolites and excreted principally in the bile. Eplerenone is well tolerated in acute and chronic safety pharmacology studies. Ongoing phase III trials of eplerenone in the treatment of hypertension and heart failure are underway. These studies will extend our understanding of selective aldosterone receptor antagonism in the treatment of chronic cardiovascular disease.
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Levin S, Mayer-Davis EJ, Ainsworth BE, Addy CL, Wheeler FC. Behavioral and demographic correlates of diabetes, hypertension and overweight among the Catawba Indian Nation. Ethn Dis 2002; 11:241-50. [PMID: 11455999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
OBJECTIVE In 1998, the Catawba Diabetes and Health Survey (CDHS) was conducted among adult members of the Catawba Indian Nation living in the Carolinas to determine the prevalence of diabetes and other health conditions, and to assess the population's health-related behaviors. DESIGN A population-based sample of adult members of the Catawba Indian Nation (N = 633) were surveyed by telephone or in person regarding health status and health-related behaviors. Logistic regression was used to determine demographic and behavioral correlates of diabetes, hypertension, and overweight among the Catawba. RESULTS Age-adjusted prevalence rates of self-reported diabetes, hypertension and overweight were 12.3%, 29.1%, and 63.8%, respectively. Older age was related to diabetes, hypertension, and overweight (P<.0001 each), and heavier weight status was related to diabetes (P = .026) and hypertension (P<.0001). Nearly 40% of the Catawba are physically inactive (29.5% men, 46.5% women). Physical inactivity was related to diabetes and hypertension among men only, and related to overweight among women only (P<.05 each). Current smoking was inversely related to overweight among men and women (P = .002). Dietary behavior was not associated with the health outcomes. CONCLUSION Given the high rates of overweight and physical inactivity, reducing the rates of both may be very important for the health of the Catawba, considering their association with diabetes and hypertension.
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Levin S. Giants and dwarfs in the Bible. ADLER MUSEUM BULLETIN 2001; 27:14-15. [PMID: 20306605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Levin S. Hebrew medical amulets. ADLER MUSEUM BULLETIN 2001; 7:8-12. [PMID: 11611426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Abstract
BACKGROUND A novel synthetic compound, SU5416, inhibits subcutaneous tumor growth of cells. Because angiogenesis in tumor growth and wound healing involves similar mechanisms, we examined whether SU5416 inhibits wound-induced angiogenesis. METHODS Sixteen female BALB/c mice were randomized to receive either SU5416 (n = 8) or vehicle alone (n = 8) on day -2. On day 0, transparent window chambers were implanted into the dorsal skin flap. Treatment was stopped on day 7. On days 1, 7, and 14, micrographs of the windows were taken and microvessel density was estimated. RESULTS On day 1, no statistically significant difference was noted between the microvessel density in controls and treatments. After the mice underwent treatment from day -2 to day 7 and microvessel densities were analyzed on day 7, angiogenesis was significantly inhibited in the SU5416 group (P <.001). Seven days after cessation of treatment, however, the SU5416 group showed complete recovery in angiogenesis. The increase in microvessel density in the SU5416 group on day 14 from day 7 was not significantly different from that of the control group (P >.05). CONCLUSIONS We observed that SU5416, a known inhibitor of tumor-induced angiogenesis, also inhibited wound-induced angiogenesis in our murine wound model. This inhibitory effect is significant while the mice are undergoing treatment.
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Levin S, Mayer-Davis EJ, Ainsworth BE, Addy CL, Wheeler FC. Racial/ethnic health disparities in South Carolina and the role of rural locality and educational attainment. South Med J 2001; 94:711-8. [PMID: 11531179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
BACKGROUND The prevalence of selected health indicators were compared among the Catawba Indians, African Americans, and whites in South Carolina, considering the possible role of rural locality and education. METHODS Catawba members were respondents of a 1998 survey (N = 808). Other South Carolina residents were respondents of the 1995-1997 Behavioral Risk Factor Survey (4,150 whites and 1,413 African Americans). Prevalence of cardiovascular disease, diabetes, hypertension, overweight, poor health, smoking, physical inactivity, and poor diet were compared among the racial/ethnic groups. Logistic regression analyses were conducted within strata of urban/rural locality and education to determine whether these factors were associated with the adverse health indicators. RESULTS Both Catawba and African Americans had higher prevalence of diabetes, hypertension, overweight, poor health, physical inactivity, and poor diet than whites. In addition, prevalence of diabetes, poor health, smoking, and poor diet were higher among the Catawba than among African Americans. Restricting the analyses to comparisons within urban/rural locality had little effect, whereas restricting the analyses to comparisons by education level eliminated many of the disparities among those with low education. CONCLUSIONS Prevalence of chronic disease and adverse health behavior are higher among the Catawba than among other residents of South Carolina, especially compared with white residents.
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Abstract
The rate of infectious complications in SOT recipients has declined dramatically. As improvements in immunosuppressive therapy, surgical techniques, and diagnostics and antimicrobial treatment continue, further declines in infectious complications are expected. Refinements to preemptive therapy for high-risk patients are likely to contribute further to this decrease. Further investigation is required to define what role various infectious agents play in chronic allograft injury and rejection.
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Mayer-Davis EJ, Levin S, Bergman RN, D'Agostino RB, Karter AJ, Saad MF. Insulin secretion, obesity, and potential behavioral influences: results from the Insulin Resistance Atherosclerosis Study (IRAS). Diabetes Metab Res Rev 2001; 17:137-45. [PMID: 11307179 DOI: 10.1002/dmrr.185] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND This work was conducted to evaluate associations of insulin secretion with overall and central obesity, dietary fats, physical activity, and alcohol. METHODS A frequently sampled intravenous glucose tolerance test (FSIGT) was used to assess acute insulin response to glucose (AIR) and insulin sensitivity (S(I)) among adult participants (n=675 with normal, NGT; n=332 with impaired glucose tolerance, IGT) in the Insulin Resistance Atherosclerosis Study (IRAS). Disposition index (DI) was calculated as the sum of the log-transformed AIR and S(I) to reflect pancreatic compensation for insulin resistance. Obesity was measured as body mass index (kg/m(2), BMI) and central fat distribution by waist circumference (cm). Dietary fat intake (total, saturated, polyunsaturated, oleic acid), physical activity, and alcohol intake were assessed by standardized interview. RESULTS In unadjusted analyses, BMI and waist were each positively correlated with AIR among NGTs (r=0.26 and 0.23, respectively; p<0.0001) but correlations were weaker among the IGTs (r=0.10, NS; r=0.13, p<0.05 for BMI and waist, respectively). BMI and waist were inversely correlated with DI among NGTs (r=-0.13 and -0.20, respectively; p<0.0001) and among IGTs (r=-0.20 and -0.19, respectively, p<0.0001). Dietary fat variables were positively related, and alcohol was inversely related, to AIR among NGTs (p<0.01) but not among IGTs. With all factors considered simultaneously in a pooled analysis of IGTs and NGTs, waist, but not BMI, was positively associated with AIR (p<0.001) and inversely associated with DI (p<0.01). None of the behavioral variables were independently related to either outcome. CONCLUSION Among non-diabetic patients, central obesity appears to be related to higher insulin secretion, but to lower capacity of the pancreas to respond to the ambient insulin resistance.
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Manzarbeitia C, Reich DJ, Rothstein KD, Braitman LE, Levin S, Munoz SJ. Tacrolimus conversion improves hyperlipidemic states in stable liver transplant recipients. Liver Transpl 2001; 7:93-9. [PMID: 11172391 DOI: 10.1053/jlts.2001.21289] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
With improvements in surgical technique and the advent of new and more effective immunosuppressive agents, survival rates in liver transplant recipients have dramatically improved. However, hyperlipidemia frequently develops in patients administered cyclosporine-based immunosuppression long-term, although it appears to occur less often with newer, tacrolimus-based regimens. We sought to determine whether an isolated change in the baseline immunosuppressive regimen (cyclosporine to tacrolimus) would improve hyperlipidemic states in these patients. Twenty-one long-term stable liver transplant recipients with hyperlipidemia, manifested by elevated cholesterol and/or triglyceride levels, were offered conversion to tacrolimus from cyclosporine A therapy. Lipid profiles were monitored at baseline (while on cyclosporine therapy) and at 1 and 3 months after conversion to tacrolimus therapy. There were no other medication manipulations. After conversion to tacrolimus therapy, mean cholesterol levels decreased from 251 to 202 mg/dL at 1 month (P <.001) and 194 mg/dL at 3 months (P <.001). Similarly, triglyceride levels decreased from 300 to 207 mg/dL by 1 month (P =.011) and 203 mg/dL by 3 months (P <.001). There was also a statistically significant decrease for very low-density lipoprotein levels at 3 months (P =.005) and low-density lipoprotein levels at 1 and 3 months (P =.013 and P =.014, respectively). High-density lipoprotein levels did not significantly change after conversion to tacrolimus therapy. Conversion was not accompanied by adverse side effects, and patients tolerated the change well. In conclusion, simple conversion from cyclosporine to tacrolimus-based immunosuppression therapy is safe and improves posttransplantation hyperlipidemia in a subgroup of liver transplant recipients.
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