Perioperative β-blocker therapy in vascular surgery: Clinical update

Patients undergoing vascular surgery comprise a group at elevated risk of fatal and nonfatal perioperative cardiovascular events. In four recent longitudinal studies, the 30-day incidence of death in such patients was 3% to 6%, and the incidence of myocardial infarction was 5% to 14%. Growing evidence suggests that β-adrenergic receptor antagonists prevent cardiovascular morbidity and mortality in high-risk patients undergoing noncardiac surgery, including those undergoing vascular surgery. This article reviews the available evidence concerning β-blockers and provides guidance for their use in the perioperative setting

Treating arteries instead of risk factors: A paradigm change in management of atherosclerosis

Background and Purpose: Until recently, atherosclerosis was thought to be inexorably progressive. Beginning in 2001 and implemented in our vascular prevention clinics by 2003, we have been treating arteries rather than risk factors. We studied the proportion of patients with plaque progression vs regression before and after this change in paradigm. Methods: Carotid total plaque area was measured by ultrasound at baseline and during follow-up. Before 2003, patients were treated according to consensus guidelines. After 2003, patients with plaque progression were treated more intensively, with the explicit goal of halting plaque progression or achieving regression. RESULTS: Four thousand three-hundred seventy-eight patients had serial plaque measurements in a given year between 1997 and 2007; 47% were female. Mean age at time of referral was 60 (SD, 15); this increased steeply (from age 50 to 62 years over the first 5 years) as we focused on stroke prevention. The annual rate of plaque progression increased steeply as the clinic populations aged but then abruptly decreased after implementation of the new approach to therapy. Before 2003, approximately half the patients had plaque progression and ≈25% had regression; by 2005, this had reversed. Changes in plasma lipids show that the differences were attributable to plaque measurement, not simply more intensive therapy for all patients. By 2007, patients with progression had lower levels of low-density lipoprotein than those with regression. Conclusions: Treating arteries without measuring plaque would be like treating hypertension without measuring blood pressure. A clinical trial to test this approach is being designed. © 2010 American Heart Association, Inc

Decline in the severity of carotid atherosclerosis and associated risk factors from 2002 to 2014

Background and Purpose-Several recent studies suggest declining rates of carotid revascularization for patients with carotid stenosis. We investigated whether carotid atherosclerosis severity has declined in recent years. Methods-We used carotid ultrasound to evaluate stenosis and plaque area in 6039 patients presenting to vascular medicine clinics in 3 eras: 2002 to 2005, 2006 to 2009, and 2010 to 2014. Results-The total plaque area at the time of referral to the clinics declined by 24% between 2002 and 2014; the percentage of patients presenting with carotid stenosis \u3c60% declined by 29.9%, and the number presenting with \u3c80% stenosis declined by 36.4%. There were significant reductions in plasma lipids and blood pressure during the same interval. Conclusions-Atherosclerosis severity seems to be declining over time. Better treatment of risk factors in the community may be responsible

What level of plasma homocyst(e)ine should be treated? Effects of vitamin therapy on progression of carotid atherosclerosis in patients with homocyst(e)ine levels above and below 14 μmol/L

High levels of plasma homocyst(e)ine (H[e]) are associated with increased vascular risk. Treatment is being contemplated, but the level at which patients should be treated is not known. We compared the response of carotid plaque to vitamin therapy in patients with H(e) above and below 14 μmol/L, a level commonly regarded as high enough to warrant treatment. Two-dimensional B-mode ultrasound measurement of carotid plaque was used to assess the response to vitamin therapy with folic acid 2.5 mg, pyridoxine 25 mg, and cyanocobalamin 250 μg daily, in 101 patients with vascular disease (51 with initial plasma levels above, and 50 below 14 μmol/L). Among patients with plasma H(e) \u3e14 μmol/L, the rate of progression of plaque area was 0.21 ± 0.41 cm2/year before vitamin therapy, and -0.049 ± 0.24 cm2/year after vitamin therapy (P2 = .0001; paired t test). Among patients with levels \u3c14 μmol/L, the rate of progression of plaque was 0.13 ± 0.24 cm2/ year before vitamin therapy and -0.024 ± 0.29 cm2/year after vitamin therapy (P2 = .022, paired t test). The change in rate of progression was -0.15 ± .44 cm2/year below 14 μmol/L, and -0.265 ± 0.46 cm2/year above 14 μmol/L (P = 0.20). Vitamin therapy regresses carotid plaque in patients with H(e) levels both above and below 14 μmol/L. These observations support a causal relationship between homocyst(e)ine and atherosclerosis and, taken with epidemiologic evidence, suggest that in patients with vascular disease, the level to treat may be \u3c9 μmol/L. © 2000 American Journal of Hypertension, Ltd

Microarray resources for genetic and genomic studies in chicken: a review

Advent of microarray technologies revolutionized the nature and scope of genetic and genomic research in human and other species by allowing massively parallel analysis of thousands of genomic sites. They have been used for diverse purposes such as for transcriptome analysis, CNV detection, SNP and CNV genotyping, studying DNA-protein interaction, and detection of genome methylation. Microarrays have also made invaluable contributions to research in chicken which is an important model organism for studying embryology, immunology, oncology, virology, evolution, genetics, and genomics and also for other avian species. Despite their huge contributions in life science research, the future of microarrays is now being questioned with the advent of massively parallel next generation sequencing (NGS) technologies, which promise to overcome some of the limitations of microarray platforms. In this article we review the various microarray resources developed for chicken and their past and potential future applications. We also discuss about the future of microarrays in the NGS era particularly in the context of livestock genetics. We argue that even though NGS promises some major advantages-in particular, offers the opportunity to discover novel elements in the genome-microarrays will continue to be major tools for research and practice in the field of livestock genetics/genomics due to their affordability, high throughput nature, mature established technologies and ease of application. Moreover, with advent of new microarray technologies like capture arrays, the NGS and microarrays are expected to complement each other in future research in life science

Using a continuum model to predict closure time of gaps in intestinal epithelial cell layers

A two-dimensional continuum model of collective cell migration is used to predict the closure of gaps in intestinal epithelial cell layers. The model assumes that cell migration is governed by lamellipodia formation, cell-cell adhesion, and cell-substrate adhesion. Model predictions of the gap edge position and complete gap closure time are compared with experimental measures from cell layer scratch assays (also called scratch wound assays). The goal of the study is to combine experimental observations with mathematical descriptions of cell motion to identify effects of gap shape and area on closure time and to propose a method that uses a simple measure (e.g., area) to predict overall gap closure time early in the closure process. Gap closure time is shown to increase linearly with increasing gap area; however, gaps of equal areas but different aspect ratios differ greatly in healing time. Previous methods that calculate overall healing time according to the absolute or percent change in gap area assume that the gap area changes at a constant rate and typically underestimate gap closure time. In this study, data from scratch assays suggest that the rate of change of area is proportional to the first power or square root power of area