A-dip of the aortic valve by M-mode echocardiography

We present a case with the previously unreported finding of an a-dip in the M-mode tracing of the aortic valve. An a-dip is commonly seen in the M-mode tracing of the pulmonic valve motion, and represents near equalization of pulmonary artery and right ventricular end- -diastolic pressures during atrial contraction. M-mode echocardiography has become an ancillary study to the basic two-dimensional examination, but can often convey important features of cardiac hemodynamics quite elegantly, as the present case demonstrates

EVects of an invasive forest pathogen on abundance of ticks and their vertebrate hosts in a California Lyme disease focus

Abstract Invasive species, including pathogens, can have important eVects on local ecosystems, including indirect consequences on native species. This study focuses on the eVects of an invasive plant pathogen on a vertebrate community and Ixodes paciWcus, the vector of the Lyme disease pathogen (Borrelia burgdorferi) in California. Phytophthora ramorum, the causative agent of sudden oak death, is a nonnative pathogen killing trees in California and Oregon. We conducted a multi-year study using a gradient of SODcaused disturbance to assess the impact on the dusky-footed woodrat (Neotoma fuscipes) and the deer mouse (Peromyscus maniculatus), two reservoir hosts of B. burgdorferi, as well as the impact on the Columbian black-tailed deer (Odocoileus hemionus columbianus) and the western fence lizard (Sceloporus occidentalis), both of which are important hosts for I. paciWcus but are not pathogen reservoirs. Abundances of P. maniculatus and S. occidentalis were positively correlated with greater SOD disturbance, whereas N. fuscipes abundance was negatively correlated. We did not Wnd a change in space use by O. hemionus. Our data show that SOD has a positive impact on the density of nymphal ticks, which is expected to increase the risk of human exposure to Lyme disease all else being equal. A positive correlation between SOD disturbance and the density of nymphal ticks was expected given increased abundances of two important hosts: deer mice and western fence lizards. However, further research is needed to integrate the direct eVects of SOD on ticks, for example via altered abiotic conditions with host-mediated indirect eVects

Sacred Cows and Sympathetic Squirrels: The Importance of Biological Diversity to Human Health

Dobson and colleagues describe how some host species act to reduce the risk of transmission of virulent zoonotic pathogens to humans

Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests

Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008–2010) in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming

Quantifying dilution and amplification in a community of hosts for tick-borne pathogens

Recent controversy over whether biodiversity reduces disease risk (dilution effect) has focused on the ecology of Lyme disease, a tick-borne zoonosis. A criticism of the dilution effect is that increasing host species richness might amplify disease risk, assuming that total host abundance, and therefore feeding opportunities for ticks, increase with species richness. In contrast, a dilution effect is expected when poor quality hosts for ticks and pathogens (dilution hosts) divert tick blood meals away from competent hosts. Even if host densities are additive, the relationship between host density and tick encounters can be nonlinear if the number of ticks that encounter a host is a saturating function of host density, which occurs if ticks aggregate on the remaining hosts rather than failing to find a host before death. Both dilution and amplification are theoretical possibilities, and assessing which is more prevalent required detailed analyses of empirical systems. We used field data to explore the degree of tick redistribution onto fewer individuals with variation in intraspecific host density and novel data-driven models for tick dynamics to determine how changes in vertebrate community composition influence the density of nymphs infected with the Lyme bacterium. To be conservative, we allowed total host density to increase additively with species richness. Our long-term field studies found that larval and nymphal ticks redistribute onto fewer individuals as host densities decline, that a large proportion of nymphs and adults find hosts, and that mice and chipmunks feed a large proportion of nymphs. White-footed mice, eastern chipmunks, short-tailed shrews, and masked shrews were important amplification hosts that greatly increased the density of infected nymphs. Gray squirrels and Virginia opossums were important dilution hosts. Removing these two species increased the maximum number of larvae attached to amplification hosts by 57%. Raccoons and birds were minor dilution hosts under some conditions. Even under the assumption of additive community assembly, some species are likely to reduce the density of infected nymphs as diversity increases. If the assumption of additivity is relaxed, then species that reduce the density of small mammals through predation or competition might substantially reduce disease risk.This is the publisher’s final pdf. The article is copyrighted by the Ecological Society of America and published by John Wiley & Sons, Inc. It can be found at: http://esajournals.onlinelibrary.wiley.com/hub/journal/10.1002/%28ISSN%291939-5582/Keywords: community ecology, Ixodes scapularis, ecosystem services, biodiversity, Lyme diseas

Closing the gaps in care of dyslipidemia: Revolutionizing management with digital health and innovative care models

Although great progress has been made in the diagnostic and treatment options for dyslipidemias, unawareness, underdiagnosis and undertreatment of these disorders remain a significant global health concern. Growth in digital applications and newer models of care provide novel tools to improve the management of chronic conditions such as dyslipidemia. In this review, we discuss the evolving landscape of lipid management in the 21st century, current treatment gaps and possible solutions through digital health and new models of care. Our discussion begins with the history and development of value-based care and the national establishment of quality metrics for various chronic conditions. These concepts on the level of healthcare policy not only inform reimbursements but also define the standard of care. Next, we consider the advances in atherosclerotic cardiovascular disease risk score calculators as well as evolving imaging modalities. The impact and growth of digital health, ranging from telehealth visits to online platforms and mobile applications, will also be explored. We then evaluate the ways in which machine learning and artificial intelligence-driven algorithms are being utilized to address gaps in lipid management. From an organizational perspective, we trace the redesign of medical practices to incorporate a multidisciplinary team model of care, recognizing that atherosclerotic cardiovascular disease risk is multifaceted and requires a comprehensive approach. Finally, we anticipate the future of dyslipidemia management, assessing the many ways in which atherosclerotic cardiovascular disease burden can be reduced on a population-wide scale

Cuban Americans have the highest rates of peripheral arterial disease in diverse Hispanic/Latino communities

Since Hispanic ethnicity in the United States is heterogeneous, the purpose of this study was to determine the epidemiology of peripheral arterial disease (PAD) within US Hispanic/Latino groups defined by national background

Statin and Aspirin Use Among Hispanic and Latino Adults at High Cardiovascular Risk: Findings From the Hispanic Community Health Study/Study of Latinos

BACKGROUND: Despite variations in the prevalence of cardiovascular disease and related risk factors among US Hispanic/Latino adults of diverse backgrounds, there is little information on whether disparities exist in the use of medications for the primary and secondary prevention of cardiovascular disease. We examined the prevalence of statin and aspirin use among diverse US Hispanic/Latino adults at high cardiovascular risk. METHODS AND RESULTS: A multicenter population-based study, the Hispanic Community Health Study/Study Of Latinos, included a total of 16 415 participants of Mexican, Puerto Rican, Cuban, Dominican, South American, and Central American backgrounds who were aged 18 to 74 years and enrolled between March 2008 and June 2011. Our analyses were limited to 4139 participants considered to be at high cardiovascular risk. Age-adjusted prevalence of statin and aspirin use was 25% and 44%, respectively, overall but varied by Hispanic/Latino background among those at high cardiovascular risk; statin use was significantly higher (P<0.001) among adults of Puerto Rican (33%) and Dominican (28%) backgrounds compared with adults of other backgrounds (Mexican, 24%; Cuban, 22%; Central American, 20%; South American, 22%). There was no difference in aspirin use. After adjusting for health insurance coverage, the difference in prevalence of statin use was substantially reduced among participants with a Puerto Rican background, from an odds ratio of 1.73 (95% CI 1.30-2.31) to 1.30 (95% CI 0.97-1.75), and with a Dominican background, from an odds ratio of 1.45 (95% CI 1.04-2.02) to 1.07 (95% CI 0.75-1.52), in comparison to their counterparts. CONCLUSIONS: Among Hispanic/Latino adults of diverse backgrounds, statin use was more prevalent among adults with Puerto Rican and Dominican backgrounds at high cardiovascular risk. These differences in statin use were explained, in part, by differences in insurance coverage. These findings have important implications for the prevention of disparities in cardiovascular outcomes within the growing US Hispanic/Latino population

The Association of Blood Urea Nitrogen Levels and Coronary Artery Disease

Renal dysfunction has been associated with adverse cardiovascular outcomes. Estimates of renal function routinely utilize creatinine-based measures. Serum blood urea nitrogen (BUN) levels, however, may provide supplemental information in regard to renal function as renal proximal tubule cells may increase BUN reabsorption in the setting of increased neurohormonal activation. We performed a retrospective chart review on 156 consecutive adult patients presenting to the Montefiore Medical Center Emergency Department with symptoms of unstable angina and no known prior history of coronary artery disease (CAD) who underwent cardiac catheterization as part of their index hospitalization. On multivariate analysis, admission serum BUN was associated with an increased burden of CAD on cardiac catheterization and was not associated with ruling in for myocardial infarction (MI).