bluuebunny/crossref_metadata_2025 huggingface dataset:
Biology by design: reduction and synthesis of cellular components and behaviour
Authors: Marguet Philippe , Balagadde Frederick , Tan Cheemeng , You Lingchong
Published: January 2007

Biological research is experiencing an increasing focus on the application of knowledge rather than on its generation. Thanks to the increased understanding of cellular systems and technological advances, biologists are more frequently asking not only ‘how can I understand the structure and behaviour of this biological system?’, but also ‘how can I apply that knowledge to generate novel functions in different biological systems or in other contexts?’ Active pursuit of the latter has nurtured the emergence of synthetic biology. Here, we discuss the motivation behind, and foundational technologies enabling, the development of this nascent field. We examine some early successes and applications while highlighting the challenges involved. Finally, we consider future directions and mention non-scientific considerations that can influence the field's growth.
Empirical assessment of a threshold model for sylvatic plague
Authors: Davis S , Leirs H , Viljugrein H , Stenseth N.Chr , De Bruyn L , Klassovskiy N , Ageyev V , Begon M
Published: January 2007

Plague surveillance programmes established in Kazakhstan, Central Asia, during the previous century, have generated large plague archives that have been used to parameterize an abundance threshold model for sylvatic plague in great gerbil (Rhombomys opimus) populations. Here, we assess the model using additional data from the same archives. Throughout the focus, population levels above the threshold were a necessary condition for an epizootic to occur. However, there were large numbers of occasions when an epizootic was not observed even though great gerbils were, and had been, abundant. We examine six hypotheses that could explain the resulting false positive predictions, namely (i) including end-of-outbreak data erroneously lowers the estimated threshold, (ii) too few gerbils were tested, (iii) plague becomes locally extinct, (iv) the abundance of fleas was too low, (v) the climate was unfavourable, and (vi) a high proportion of gerbils were resistant. Of these, separate thresholds, fleas and climate received some support but accounted for few false positives and can be disregarded as serious omissions from the model. Small sample size and local extinction received strong support and can account for most of the false positives. Host resistance received no support here but should be subject to more direct experimental testing.
Towards optimization of patterned superhydrophobic surfaces
Authors: Bhushan Bharat , Nosonovsky Michael , Chae Jung Yong
Published: January 2007

Experimental and theoretical study of wetting properties of patterned Si surfaces with cylindrical flat-top pillars of various sizes and pitch distances is presented. The values of the contact angle (CA), contact angle hysteresis (CAH) and tilt angle (TA) are measured and compared with the theoretical values. Transition from the composite solid–liquid–air to the homogeneous solid–liquid interface is investigated. It is found that the wetting behaviour of a patterned hydrophobic surface depends upon a simple non-dimensional parameter, the spacing factor, equal to the pillar diameter divided by the pitch. The spacing factor controls the CA, CAH and TA in the composite interface regime, as well as destabilization and transition to the homogeneous interface. We show that the assumption that the CAH is a consequence of the adhesion hysteresis and surface roughness leads to the theoretical values of the CAH that are in a reasonably good agreement with the experimental values. By decreasing the spacing factor, the values of CA=170°, CAH=5° and TA=3° are achieved. However, with further decreasing of the spacing factor, the composite interface destabilizes.
An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake
Thamnophis elegans
Authors: Sparkman Amanda M , Arnold Stevan J , Bronikowski Anne M
Published: January 2007

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake,
Thamnophis elegans
. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence.
Roots in space: a spatially explicit model for below-ground competition in plants
Authors: O'Brien Erin E , Brown Joel S , Moll Jason D
Published: January 2007

Game theory provides an untapped framework for predicting how below-ground competition will influence root proliferation in a spatially explicit environment. We model root competition for space as an evolutionary game. In response to nutrient competition between plants, an individual's optimal strategy (the spatial distribution of root proliferation) depends on the rooting strategies of neighbouring plants. The model defines and predicts the fundamental (in the absence of competition) and realized (in the presence of competition) root space of an individual plant. Overlapping fundamental root spaces guarantee smaller, yet still overlapping, realized root spaces as individuals concede some but not all space to a neighbour's roots. Root overlap becomes an intentional consequence of the neighbouring plants playing a nutrient foraging game. Root proliferation and regions of root overlap should increase with soil fertility, decline with the distance cost of root production (e.g. soil compactness) and shift with competitive asymmetries. Seemingly erratic patterns of root proliferation and root overlap become the expected outcome of nutrient foraging games played in soils with small-scale heterogeneities in nutrient availability.
Immunosenescence in some but not all immune components in a free-living vertebrate, the tree swallow
Authors: Palacios Maria G , Cunnick Joan E , Winkler David W , Vleck Carol M
Published: January 2007

A wide diversity of free-living organisms show increases in mortality rates and/or decreases in reproductive success with advancing age. However, the physiological mechanisms underlying these demographic patterns of senescence are poorly understood. Immunosenescence, the age-related deterioration of immune function, is well documented in humans and laboratory models, and often leads to increased morbidity and mortality due to disease. However, we know very little about immunosenescence in free-living organisms. Here, we studied immunosenescence in a free-living population of tree swallows,
Tachycineta bicolor
, assessing three components of the immune system and using both
in vivo
and
in vitro
immunological tests. Immune function in tree swallow females showed a complex pattern with age; acquired T-cell mediated immunity declined with age, but neither acquired nor innate humoral immunity did.
In vitro
lymphocyte proliferation stimulated by T-cell mitogens decreased with age, suggesting that reduced T-cell function might be one mechanism underlying the immunosenescence pattern of
in vivo
cell-mediated response recently described for this same population. Our results provide the most thorough description of immunosenescence patterns and mechanisms in a free-living vertebrate population to date. Future research should focus on the ecological implications of immunosenescence and the potential causes of variation in patterns among species.
Impacts of the live reef fish trade on populations of coral reef fish off northern Borneo
Authors: Scales Helen , Balmford Andrew , Manica Andrea
Published: January 2007

The live reef fish trade (LRFT) is one of the greatest but least-quantified sources of fishing pressure for several species of large coral reef fish across the Indo-Pacific. For the first time we quantify the localized impact of the LRFT. We collected data from three LRFT traders in northern Borneo, which yielded information on daily fishing effort and the species and mass of all fishes sold every day by individual fishers or vessels over 2, 3 and 8 years. Total monthly catch and relative abundance (catch-per-unit-effort) declined significantly in several species, including the most valuable species the Napoleon wrasse (
Cheilinus undulatus
, estimated changes of −98 and −78% over 8 years in catch and relative abundance, respectively) and lower-value bluelined groupers (
Plectropomus oligocanthus
: −99 and −81%) and
Epinephelus
groupers (−89 and −32%). These severe declines were rapid, species-specific and occurred in the first 2–4 years of the dataset and are, we believe, directly attributable to the LRFT. This has crucial implications for future data collection and monitoring if population collapses in other parts of the LRFT and similar wildlife trades are to be successfully detected.
The evolution of animal ‘cultures’ and social intelligence
Authors: Whiten Andrew , van Schaik Carel P
Published: January 2007

Decades-long field research has flowered into integrative studies that, together with experimental evidence for the requisite social learning capacities, have indicated a reliance on multiple traditions (‘cultures’) in a small number of species. It is increasingly evident that there is great variation in manifestations of social learning, tradition and culture among species, offering much scope for evolutionary analysis. Social learning has been identified in a range of vertebrate and invertebrate species, yet sustained traditions appear rarer, and the multiple traditions we call cultures are rarer still. Here, we examine relationships between this variation and both social intelligence—sophisticated information processing adapted to the social domain—and encephalization. First, we consider whether culture offers one particular confirmation of the social (‘Machiavellian’) intelligence hypothesis that certain kinds of social life (here, culture) select for intelligence: ‘you need to be smart to sustain culture’. Phylogenetic comparisons, particularly focusing on our own study animals, the great apes, support this, but we also highlight some paradoxes in a broader taxonomic survey. Second, we use intraspecific variation to address the converse hypothesis that ‘culture makes you smart’, concluding that recent evidence for both chimpanzees and orang-utans support this proposition.
The society of selves
Authors: Humphrey Nicholas
Published: January 2007

Human beings are not only the most sociable animals on Earth, but also the only animals that have to ponder the separateness that comes with having a conscious self. The philosophical problem of ‘other minds’ nags away at people's sense of who—and why—they are. But the privacy of consciousness has an evolutionary history—and maybe even an evolutionary function. While recognizing the importance to humans of mind-reading and psychic transparency, we should consider the consequences and possible benefits of being—ultimately—psychically opaque.
Spatial mapping of protein abundances in the mouse brain by voxelation integrated with high-throughput liquid chromatography–mass spectrometry
Authors: Petyuk Vladislav A. , Qian Wei-Jun , Chin Mark H. , Wang Haixing , Livesay Eric A. , Monroe Matthew E. , Adkins Joshua N. , Jaitly Navdeep , Anderson David J. , Camp David G. , Smith Desmond J. , Smith Richard D.
Published: January 2007

Temporally and spatially resolved mapping of protein abundance patterns within the mammalian brain is of significant interest for understanding brain function and molecular etiologies of neurodegenerative diseases; however, such imaging efforts have been greatly challenged by complexity of the proteome, throughput and sensitivity of applied analytical methodologies, and accurate quantitation of protein abundances across the brain. Here, we describe a methodology for comprehensive spatial proteome mapping that addresses these challenges by employing voxelation integrated with automated microscale sample processing, high-throughput liquid chromatography (LC) system coupled with high-resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer, and a “universal” stable isotope labeled reference sample approach for robust quantitation. We applied this methodology as a proof-of-concept trial for the analysis of protein distribution within a single coronal slice of a C57BL/6J mouse brain. For relative quantitation of the protein abundances across the slice, an 18O-isotopically labeled reference sample, derived from a whole control coronal slice from another mouse, was spiked into each voxel sample, and stable isotopic intensity ratios were used to obtain measures of relative protein abundances. In total, we generated maps of protein abundance patterns for 1028 proteins. The significant agreement of the protein distributions with previously reported data supports the validity of this methodology, which opens new opportunities for studying the spatial brain proteome and its dynamics during the course of disease progression and other important biological and associated health aspects in a discovery-driven fashion.
The Epidemiology of Atrial Fibrillation in Elderly Persons: The Tip of the Iceberg
Authors: Go Alan S.
Published: January 2007

Atrial fibrillation is the most common clinically relevant arrhythmia and preferentially afflicts elderly persons, especially persons aged ≥75 years, with associated complications of ischemic stroke and other adverse outcomes. More than 2.2 million Americans currently have atrial fibrillation, and this number is expected to increase by at least 2.5‐fold over the next 50 years. With the aging of the US and international populations, as well as the rising prevalence of clinical risk factors, the incidence and prevalence of atrial fibrillation are rising rapidly. While improved adherence to existing risk‐based therapies can reduce thromboembolic complications in elderly persons, additional research is needed to determine novel approaches to prevent the initial development of atrial fibrillation in order to decrease the individual and public health burden of this condition.
Pharmacologic Therapies for Atrial Fibrillation
Authors: Ross Heather M. , Kocovic Dusan Z. , Kowey Peter R.
Published: January 2007

Pharmacologic therapy for atrial fibrillation may be used for acute cardioversion or ventricular rate control or for long‐term therapy to maintain sinus rhythm or control ventricular rates in atrial fibrillation. Therapies must be tailored to elderly patients, with particular attention to structural heart disease, bradycardia, hypotension, and other comorbidities, including renal or hepatic insufficiency. Such considerations may dictate the use or avoidance of certain agents. Other important considerations for elderly patients include challenges associated with anticoagulation and maintaining therapeutic international normalized levels without risk of bleeding. When considering pharmacologic agents for elderly patients, it is also valuable to take into account socioeconomic issues, such as access to medications, adherence to complicated dosing schedules, and availability of appropriate clinical follow‐up to assess therapeutic efficacy and adverse reactions to various agents. A carefully constructed therapeutic regimen can provide effective symptom control and atrial fibrillation management for elderly patients.
Rate Control vs. Rhythm Control in the Management of Atrial Fibrillation in Elderly Persons
Authors: Vidaillet Humberto J.
Published: January 2007

Antiarrhythmic medications used to maintain sinus rhythm have long been the treatment of choice in atrial fibrillation. The results of five prospective randomized trials comparing the efficacy and safety of rhythm‐control to rate‐control strategies are now available. Reflecting the epidemiology of atrial fibrillation in the real world, most subjects enrolled in these investigations were elderly persons at increased risk of stroke or death. All of these trials have had similar results; these studies have failed to demonstrate a clear advantage of one treatment strategy over the other. A prespecified subgroup analysis among 3091 elderly patients in the Atrial Fibrillation Follow‐up Investigation of Rhythm Management (AFFIRM) study revealed that rhythm control was associated with a higher risk of death than rate control. This review examines developments leading to and the implications and limitations of these trials and discusses recently issued practice guidelines and the justification for ongoing efforts to develop nonpharmacologic approaches to rhythm management in atrial fibrillation.
Anticoagulation for Atrial Fibrillation in the Elderly
Authors: Halperin Jonathan L.
Published: January 2007

Atrial fibrillation is a risk factor for stroke, particularly among elderly patients. Multiple trials have established that antithrombotic therapy decreases stroke risk. Aspirin is associated with a relative risk reduction of about 21% and adjusted‐dose warfarin (international normalized ratio 2.0–3.0) is associated with a relative risk reduction of about 68%. Warfarin is more effective than aspirin but is used less often than indicated because of hemorrhagic risk and the inconvenience of coagulation monitoring. The oral direct thrombin ximelagatran has been investigated for stroke prevention in patients with atrial fibrillation in two large clinical trials. The results suggest efficacy in a fixed dose compared with well controlled warfarin. Although anticoagulation intensity was not monitored or regulated during treatment with ximelagatran, it was associated with less bleeding than warfarin. Other antithrombotic agents are under development as alternatives to warfarin, but sufficient data are not yet available to justify their clinical use in patients with atrial fibrillation.
Management of Atrial Fibrillation in Patients With Congestive Heart Failure
Authors: Stürmer Marcio Lerch , Talajic Mario , Thibault Bernard , Guerra Peter G. , Dubuc Marc , Novak Paul , Roy Denis
Published: January 2007

An increase in the prevalence of both atrial fibrillation and congestive heart failure is occurring in part because of the demographic shift toward an aging population. These two clinical entities often coexist in the same patient, resulting in the worsening of symptoms and prognosis, rendering their management even more challenging. A large clinical trial is currently examining whether a rhythm‐control strategy is superior to a rate‐control strategy in patients with congestive heart failure. New nonpharmacologic therapies such as pulmonary vein isolation are undergoing clinical investigation and may also alter the management of these patients. At present, therapy for atrial fibrillation in patients with congestive heart failure should aim first at controlling heart rate to provide symptomatic relief; then sinus rhythm should be restored if symptoms persist or if congestive heart failure worsens. For a more definitive approach in managing these patients, the authors await further clinical trial data.
Atrial Fibrillation: Management for the Geriatric Patient
Authors: Krishnan Kousik
Published: January 2007

Atrial fibrillation is one of the most common rhythm disorders encountered in the geriatric population. The diagnosis is well established, but the treatment has undergone many changes. Many long‐held notions have been challenged and new treatment options, both medical and procedural, have offered new hope in the management of this disease in the elderly. This review will describe atrial fibrillation from its diagnosis to the common and more cutting‐edge treatment modalities with special focus on the elderly population.
Endovascular Therapies for Noncoronary Atherosclerosis in the Elderly: Aortoiliac and Femorotibial Lesions
Authors: Rigatelli Gianluca , Zanchetta Mario
Published: January 2007

Many interventional cardiologists are becoming interested in the interventional treatment of noncoronary atherosclerotic disease. The elderly may be especially benefited by the application of many new techniques for the treatment of lower limb atherosclerosis, such as protection and thromboaspiration devices, new atherectomy devices, and cryoplasty. In this review the authors offer geriatric cardiologists an overview and an update of the most recent advances in techniques and results in the field of interventional treatment of aortoiliac and femorotibial artery atherosclerosis in the elderly.
Ablation Therapy of Supraventricular Tachycardia in Elderly Persons
Authors: Dreifus Leonard S. , Pollak Scott J.
Published: January 2007

Ablation of supraventricular tachycardia in elderly persons presents a challenging problem to electrophysiologists. Friable cardiac structures, prone to catheter perforation, comorbid cardiovascular disease, and the propensity to develop atrial fibrillation and thromboembolic complications, place these patients at high risk. Newer techniques for cardiac mapping and ablation, the establishment of precise ablation lines, and safer approaches to the ablation mechanism (particularly for atrial fibrillation) are presented in this review. In addition, a novel rapid ablation method to permanently cure atrial ventricular nodal re‐entry tachycardia is demonstrated.
Rate Control vs. Pulmonary Vein Isolation
Authors: Gonzalez Mario D.
Published: January 2007

Atrial fibrillation (AF) is a frequent arrhythmia encountered in clinical practice. It can be asymptomatic in some patients but incapacitating in others. Regardless of symptoms, patients at increased risk of embolism need chronic anticoagulation. In patients with AF and a rapid ventricular response that cannot be controlled with drugs, interventional procedures are required. Radiofrequency catheter ablation of the atrioventricular junction with pacemaker implantation is an effective therapeutic approach that relieves the symptoms associated with a rapid and irregular rhythm. This approach can also improve left ventricular function in patients with tachycardia‐induced cardiomyopathy. Due to the irreversible nature of this approach, it is more suitable for older patients and those with advanced left ventricular dysfunction. Many patients with a structurally normal heart have symptomatic paroxysmal AF refractory to antiarrhythmic agents. This form of AF is frequently initiated by premature atrial beats arising from the pulmonary veins. A catheter ablation technique is available to electrically isolate the pulmonary veins. This procedure can eliminate AF in many patients but can result in complications, including embolic events, pulmonary veins stenosis, and cardiac perforation.
Cardiac Resynchronization Therapy: A New Therapy for Advanced Congestive Heart Failure
Authors: Ott Peter
Published: January 2007

Despite medical therapy, many patients with advanced systolic dysfunction remain highly symptomatic. In these patients the presence of a left bundle branch block on electrocardiogram indicates significant dyssynchrony of ventricular contraction. Cardiac resynchronization, by means of biventricular pacing, results in important clinical benefits. Due to the risk for malignant ventricular arrhythmias, this technology is best combined with an implantable cardioverter defibrillator.
Antiarrhythmic Therapy in Elderly Persons: A Device‐Based Approach
Authors: Ferrick Kevin J.
Published: January 2007

The management of ventricular arrhythmias in elderly persons has undergone a dramatic evolution over the past 10 years. Although life‐threatening arrhythmias in elderly persons have been traditionally managed with a variety of pharmacologic agents, this population presents special challenges from pharmacokinetic and pharmacodynamic perspectives. Drug absorption, distribution, metabolism, and efficacy are often altered in elderly patients, resulting in a substantially narrowed therapeutic window. Nonpharmacologic therapy for ventricular arrhythmias has the advantage of not being subject to changes in metabolism, and due to recent technological advances in transvenous lead design as well as improved programming flexibility and reduction in device size, device‐based therapy for malignant ventricular arrhythmias has become more attractive for use in elderly patients. Several recent studies have suggested that device‐based therapy provides superior protection from malignant arrhythmias for both primary and secondary prevention indications. The majority of these studies suggest that the benefits of device‐based therapy are conferred to patients independent of age. In addition, the complication rate of such therapy appears to be independent of age.
Role of Electrophysiologic Studies, Signal‐Averaged Electrocardiography, Heart Rate Variability, T‐Wave Alternans, and Loop Recorders for Risk Stratification of Ventricular Arrhythmias
Authors: Iravanian Shahriar , Arshad Aysha , Steinberg Jonathan S.
Published: January 2007

Ventricular tachycardia and fibrillation are major causes of morbidity and mortality after myocardial infarction. Frequently, sudden cardiac death is the first manifestation of such malignant rhythms. Optimal risk stratification strategies in this population are of utmost importance. In this review the authors discuss the background and clinical use of invasive tests, such as electrophysiologic study and implantable loop recorders, and noninvasive tests, such as signal‐averaged electrocardiography, heart rate variability, and T‐wave alternans. The utility, indications, and limitations of each test in clinical practice are discussed, especially for the purpose of postmyocardial infarction risk stratification in the elderly population.
Assessment of Age‐Related Changes in Left Ventricular Structure and Function by Freehand Three‐Dimensional Echocardiography
Authors: Khouri Michel G. , Maurer Mathew S. , Rumbarger Lyna El‐Khoury , King Donald L.
Published: January 2007

To determine age‐related changes in left ventricular (LV) structure and function, the authors used freehand three‐dimensional echocardiography, a previously validated tomographic technique, to measure LV mass, volumes, and derived parameters in 94 sedentary, but ambulatory and clinically healthy, adult male and female volunteers aged 20–94. LV volumes and mass were significantly greater in men than in women(p<0.001) and remained greater after adjustment for body surface area and height (p<0.05). Declines in end‐diastolic and stroke volumes with age were reduced or absent after accounting for body size. By multivariate analysis, age accounted for only about 6%–11% of the variance among LV volumes and mass, in comparison with body surface area and gender, which accounted jointly for about 46%–77% of the variance. In conclusion, changes occur in LV structure and function with normal aging, but these changes are relatively minor when body size and gender are taken into account.
Bystanders of Out‐of‐Hospital Sudden Heart Attack: Knowledge and Behaviors Among Older African Americans
Authors: Demirovic Jasenka , Li Yen‐Peng
Published: January 2007

A community‐based study of 425 older African Americans assessed whether their knowledge and behaviors were consistent with current recommendations regarding out‐of‐hospital sudden heart attack. More than 90% of the study participants were able to recognize major symptoms of sudden heart attack such as chest pain, shortness of breath, weakness, fatigue, fainting, and sweating, and, to a lesser extent, atypical pain, nausea, lightheadedness, and unexplained anxiety. When asked what they would do first in case they witness sudden heart attack, 97% responded that they would call emergency medical services. In contrast, of the participants who actually witnessed sudden heart attack, 80% called emergency medical services, whereas 20% waited to see if the symptoms would go away; called a neighbor, relative, or a friend before contacting emergency medical services; or took the victim to the hospital. These findings show that reported behavioral intentions were satisfactory, but actual bystanders' actions were not always consistent with current recommendations regarding sudden heart attack.
Systolic Hypertension in Older Persons: Complexities in Clinical Decision Making
Authors: Foody JoAnne Micale , Chaudhry Sarwat I. , Krumholz Harlan M.
Published: January 2007

While the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) challenges clinicians to aggressively manage systolic hypertension, few data are available to guide clinicians in treating older persons with this condition. In older persons, hypertension treatment decisions must often rely on extrapolations and fall into a gray area where optimal choice for an individual patient may be unclear. In these instances, patients must understand the probable outcomes of options, consider the personal value they place on benefits vs. risks, and participate with their practitioners in deciding on treatment. Shared decision making is the process by which the health care provider and patient share all stages of the decision‐making process and both discuss treatment preferences and agree on a final management plan. Our challenge as clinicians is to ensure that all older patients have the opportunity to be treated in a way that is evidence‐based and patient‐centered. As with most health care decisions in older persons, those regarding blood pressure control should promote evidence‐based care that is complementary with individualized risk, benefit ratios, patient preferences, and treatment goals.
Experience With Providing Drugs for Seniors in Canada
Authors: Gray Jean
Published: January 2007

The provincial and territorial governments in Canada are responsible for the provision of health care to all Canadians and, as part of this mandate, they provide drug coverage to all hospitalized patients regardless of age, and to seniors and patients with certain diagnoses, dependent on some forms of means testing. The federal government is responsible for regulation and setting standards for health care. It provides financial subsidies to the provincial programs as well as direct funding for specific groups of individuals. This article reviews the roles of each level of government in the provision of pharmaceuticals to seniors in Canada.
The Medicare Part D Drug Benefit: Lessons From the Experience With Drug Discount Cards
Authors: Doering Paul L.
Published: January 2007

The Medicare Modernization Act of 2003 provides federal assistance to eligible beneficiaries by paying for their prescription medications. While the full program will be implemented in January 2006, a transitional drug discount card program has been ongoing since mid‐2004. This paper reviews some of the operational details of that program and the hurdles created by the complexity of the program. By carefully looking back on these hurdles, perhaps one can anticipate some of the problems that will likely be encountered when the full program is implemented and assist patients in realizing its maximum benefits.
Medicare Part D: An Overview of Its Practical and Clinical Impact
Authors: Usdin Steve
Published: January 2007

The Medicare Part D outpatient prescription drug benefit will transform American health care delivery. In addition to increasing access to medicines, it will have a profound impact on physicians and drug developers. Senior citizens and other Medicare recipients will be forced to come to terms with a complex benefit structure and to make difficult choices. Physicians will have to help their patients navigate the new benefit as well as adjust their practices to deal with multiple formularies with different coverage policies. Medicare is creating a framework for collecting evidence, both from studies of comparative efficacy of drugs and from automated tracking of outcomes.
United States Pharmacopeia Development of the Medicare Model Formulary Guidelines
Authors: Bielory Leonard
Published: January 2007

Prescription drug formularies are a key element in prescription drug benefit management. The use of formularies can both increase the quality of prescribing and reduce the costs of prescription drug therapy. The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 specified that an external agency, the United States Pharmacopeial Convention, Inc. (USP) through the Secretary of the United States Department of Health and Human Services develop model formulary guidelines for prescription drug plans. The model formulary guidelines are to assist individual drug plans in developing formularies that would qualify for participation in the Medicare Part D prescription program. The guidelines were developed through a Model Guidelines Expert Committee assisted by USP staff and following input from patient advocate groups, health care organizations, and pharmaceutical organizations over a period of 8 months (April 2004 to December 2004). The USP Model Formulary Guidelines organize prescription medications into 41 therapeutic categories (32 with associated pharmacologic classes and nine with no associated pharmacologic classes), 137 pharmacologic classes, and 146 unique therapeutic categories and pharmacologic classes.
Effects of Aging on the Diagnostic Assessment of Valvular Heart Disease
Authors: Strom Joel A. , VanAuker Michael D. , Carabello Blase A.
Published: January 2007

The diagnostic assessment of the severity of valvular heart disease in the older population is impacted by the anatomic and physiologic changes that accompany normal aging and by the interposition of diseases prevalent in the elderly. In this paper, the impact of those changes on the assessment of valvular heart disease will be reviewed. Special attention will be paid to the effects of age and disease on the measurement of the pressure drop and orifice area.
Treatment of Non—ST‐Elevation Acute Coronary Syndrome in the Elderly: Current Practice and Future Opportunities
Authors: Alexander Karen P. , Peterson Eric D.
Published: January 2007

The care of elderly patients with non—ST‐elevation acute coronary syndrome is challenging, given the wide variability in physiologic condition and preferences among this patient group. Due to a higher burden of comorbidity, the elderly face high risks for death and complications from non—ST‐elevation acute coronary syndrome relative to younger patients. Accordingly, they also have greater potential benefits from effective therapies. Antithrombotic therapy, invasive cardiac care, lipid lowering, and prevention advice, however, are all used less often in the elderly, even when no contraindications exist. Attention to individualized dosing and safety monitoring is also important for elderly patients. Increased awareness of the beneficial impact of therapies on outcomes in the elderly, along with vigilance for adverse events, should enable care to move from the state of uncertainty to opportunity in this high‐risk population.
Dyslipidemia in Older Adults
Authors: Jones Peter H.
Published: January 2007

3‐Hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins) have been shown in many large, randomized clinical trials to be safe and highly effective for decreasing low‐density lipoprotein cholesterol, thus preventing cardiovascular events and decreasing mortality in patients both with and without prior cardiovascular disease. Statins are also appropriate agents for older adults, although they remain underutilized in this population. This article uses three typical case history presentations to review the most recent clinical trial data and guidelines on statin therapy to provide practical guidance on clinical decision making for lipid‐lowering therapy in the geriatric population.
Arterial Stiffness, Isolated Systolic Hypertension, and Cardiovascular Risk in the Elderly
Authors: Safar Hélène , Chahwakilian Anne , Boudali Yasmina , Debray‐Meignan Sylvie , Safar Michel , Blacher Jacques
Published: January 2007

Isolated systolic hypertension is an important cardiovascular risk factor in the elderly. In addition to systolic blood pressure, pulse pressure, pulse wave velocity, and carotid wave reflections are also strong cardiovascular risk factors in the elderly, as a consequence of the two main determinants of systolic hypertension: increased arterial stiffness and early wave reflections. Taken together, all these findings should help to optimize drug treatment, which has been shown to produce important but thus far insufficient beneficial effects on cardiovascular morbidity and mortality.
B‐Type Natriuretic Peptide Predicts Postdischarge Prognosis in Elderly Patients Admitted Due to Cardiogenic Pulmonary Edema
Authors: Valle Roberto , Prevaldi Carolina , D'Eri Alessandra , Fontebasso Alessandra , Giovinazzo Prospero , Noventa Federica , Barro Sabrina , Carbonieri Emanuele , Milani Loredano , Aspromonte Nadia
Published: January 2007

To examine the prognostic role of predischarge B‐type natriuretic peptide (BNP) levels in elderly patients admitted to the hospital due to cardiogenic pulmonary edema, 203 patients consecutively admitted to the Heart Failure Unit of the Cardiology Department were retrospectively evaluated. The primary clinical end point selected was a combination of: 1) deaths; plus 2) readmissions to the hospital for heart failure in the 6 months after discharge. Thirty‐one deaths (15.3%) and 44 readmissions for heart failure (21.7%) were recorded. Cox multivariate regression analysis confirmed that BNP cutoff values (identified on receiver‐operated curve analysis) are the most accurate predictor of events. Hazard ratios (Hrs) increased from the lowest, for BNP ≤200 pg/mL (HR=1), through BNP 201–499 pg/mL (HR=2.3200; p=0.0174), to the highest, for BNP ≥500 pg/mL (HR=3.6233; p=0.0009). This study demonstrates that BNP is useful in predischarge risk stratification of elderly patients with cardiogenic pulmonary edema.
Efficacy of Combination Therapy With Amlodipine Besylate/Benazepril Hydrochloride for Lowering Systolic Blood Pressure in Stage 2 Hypertension
Authors: Neutel Joel M. , Smith David H.G. , Weber Michael A. , Schofield Lesley , Purkayastha Das , Gatlin Marjorie
Published: January 2007

The Systolic Evaluation of Lotrel Efficacy and Comparative Therapies (SELECT) study compared daily treatment with combination amlodipine besylate/benazepril hydrochloride 5/20 mg, amlodipine besylate 5 mg, and benazepril hydrochloride 20 mg in 505 patients aged 55 years of age or older with stage 2 hypertension (systolic blood pressure [BP] ≥160 and ≤200 mm Hg and diastolic BP ≥60 and ≥100 mm Hg). BP and pulse pressure were assessed by conventional office BP measurements and 24‐hour ambulatory BP monitoring. In this analysis, combination therapy was associated with significantly greater reductions in mean 24‐hour BP, pulse pressure, and mean ambulatory BP during various time intervals compared with either monotherapy in the intent‐to‐treat population, in those with isolated and predominantly systolic hypertension, and in dippers and nondippers. Adverse event rates were low and similar in all treatment groups. This study demonstrated that combination therapy is superior to monotherapy in older patients with stage 2 systolic hypertension and is well tolerated.
Percutaneous Treatment of Valvular Heart Disease: Catheter‐Based Aortic Valve Replacement and Mitral Valve Repair Therapies
Authors: Feldman Ted , Herrmann Howard C. , Goar Fred St.
Published: January 2007

Until recently, percutaneous catheter therapy for valvular heart disease was limited to catheter balloon valvuloplasty for aortic, mitral, or pulmonic stenosis. A number of new approaches to percutaneous valve therapy are now developing rapidly, including methods for catheter‐based valve replacement and repair. Stent‐mounted valve prostheses have been successfully implanted in the pulmonic and aortic positions. These devices have been constructed using pericardial valve leaflets mounted inside balloon‐expandable or self‐expanding stents and have been used in patients who are high risk for valve replacement surgery. Percutaneous valve repair is also being developed for mitral regurgitation. Direct leaflet repair and percutaneous annuloplasty are being employed in clinical trials. All the percutaneous approaches are based on existing surgical techniques and offer less invasive alternatives. The era of percutaneous valve therapy has clearly arrived, and ongoing trials will define the clinical role for these new therapies.
Effects of Long‐Term and Ongoing Cardiac Rehabilitation in Elderly Patients With Coronary Heart Disease
Authors: Mathieu Gayda , Juneau Martin , Levesque Sylvie , Guertin Marie Claude , Nigam Anil
Published: January 2007

The authors assessed the effect of very long‐term cardiac rehabilitation (over 1 year) on exercise tolerance and coronary heart disease risk factors in patients older than 80 years with coronary heart disease relative to an elderly cohort without coronary heart disease. Included in this retrospective analysis were patients older than 80 at the time of their last evaluation who had completed at least 1 year of a cardiac prevention and exercise training program. A total of 43 coronary heart disease patients and 15 age‐matched healthy subjects were included in this study. Long‐term cardiac rehabilitation in very elderly coronary heart disease patients was shown to be feasible and effective in improving functional capacity (+5.4% after 1 year; P <.05) and risk factor control, and slowing the decline in exercise tolerance that occurs with normal aging.
Preoperative Exercise Echocardiography and Perioperative Cardiovascular Outcomes in Elderly Patients Undergoing Cancer Surgery
Authors: Shoyeb Abu , Weinstein Howard , Roistacher Nancy , Spaltro Barbara , Bates Andrew , Yusim Galina , Steingart Richard
Published: January 2007

Limited information is available on the value of exercise echocardiography (EE) for identifying operative risk in elderly patients undergoing noncardiac surgery. The authors investigated the outcome in 221 consecutive patients 75 years and older who had EE before intermediate‐ or high‐risk cancer surgery. Baseline clinical data, postoperative adverse cardiovascular events (PACE), and 30‐day mortality were collected from the medical records and the Social Security Death Index. The mean age ± SD of the group was 78.9±3.5 years; 57% were men. Significant cardiovascular abnormalities (by echocardiography) were present in 71.5%. Mean metabolic equivalents ± SD achieved during exercise was 4.9±1.9. EE identified 50 (22.6%) patients with ischemia and/or infarction. Perioperative β‐blockers were used in 80% of patients with coronary artery disease vs 48.5% without coronary artery disease (P<.0001). There were 31 PACE in 26 (11.8%) patients. Atrial fibrillation was the most common PACE, seen in 18 (8.1%) patients, followed by congestive heart failure in 8 (3.6%), acute coronary syndrome in 2 (0.9%), and cardiac arrest in 1 (0.5%). Thirty‐day mortality was only 0.9%. Hospital lengths of stay for patients with and without PACE were 16.8±14.9 and 8.5±4.8 days (P<.0001), respectively. An abnormal EE predicted PACE (22% vs 8.8%; P<.025). Perioperative β‐blockers reduced the incidence of postoperative atrial fibrillation (4.9% vs 12.2%; P=.052). In conclusion, EE is feasible in very elderly patients. There is a high prevalence of cardiac abnormalities in the elderly. An abnormal EE predicts PACE, which, in turn, is associated with increased length of stay.
Epidemiology, Clinical Features, and Prognosis of Acute Myocardial Infarction in the Elderly
Authors: Rich Michael W.
Published: January 2007

The incidence and prevalence of acute myocardial infarction (MI) increase progressively with age. In the United States, over 60% of acute MIs occur in patients 65 years of age or older, and approximately one third occur in persons over age 75. In addition, mortality rates following acute MI increase exponentially with age, such that approximately 60% of all MI deaths in the United States occur in the 6% of the population 75 years of age or older. The clinical features of acute MI vary by age. In particular, very elderly patients are less likely than younger patients to report chest pain. Conversely, confusion or altered mental status may be the presenting manifestation of acute MI in up to 20% of patients over 85 years of age. Older patients are also more likely to have “silent” or unrecognized MIs, as well as MIs without ST‐segment elevation, compared with younger patients. Elderly patients with acute MI are more likely than younger patients to experience heart failure, atrial fibrillation, cardiac rupture, and shock, all of which are associated with increased mortality. Other factors contributing to the poor prognosis following acute MI in elderly individuals include a marked decline in cardiovascular reserve in the elderly, increased prevalence of comorbid conditions, underutilization of evidence‐based therapies, and increased risk of iatrogenic complications.
Does Heart Rate Predict Mortality in Older, Low‐Level Care Residents?
Authors: Fisher Alexander A. , Davis Michael W. , Srikusalanukul Wichat , Budge Marc M.
Published: January 2007

To determine whether abnormalities in heart rate (HR) were associated with long‐term mortality in older, low‐level care residents, 179 randomly selected persons aged 65 and older (mean, 83.2+7.0 [SD] years; 80% women) were prospectively assessed. At baseline, duplicate measurements of HR and blood pressure were recorded in the supine position and after standing. During the 5‐year follow‐up period, 97 (54%) participants died. Cox survival analysis revealed no association with total mortality when resting HR was analyzed as a continuous or categoric variable (<60, 61–89, and ≥90 bpm). However, HR ≥90 bpm was associated with increased risk of dying in residents who used a walking aid (relative risk, 3.48; 95% confidence interval, 1.07–11.30; p=0.038). Postural HR change was not associated with mortality risk. The authors concluded that resting HR and postural change in HR are not significant predictors of 5‐year mortality in older, low‐level care residents, except in persons using a walking aid.