Autoxidation of fatty acid monolayers adsorbed on silica gel: III. Effects of saturated fatty acids and cholesterol

Autoxidation of fatty acid monolayers on silica consisting of multiple components to simulate biomembranes has been studied by the rate of fatty acid disappearance and the products formed. When palmitic acid was incorporated into linoleic acid monolayers, the decrease in rate was proportional to the amounts of plamitic acid present. The protective effect of the saturated fatty acid diminished rapidly as the chain length of the saturated fatty acid decreased below C12. With acids of medium chain length, C12 was more effective than C16. In pure linoleic acid monolayers, when the surface coverage was reduced to only 5% of the available adsorption sites, and in the case of palmitic acid-linoleic acid monolayers, the rate dropped drastically and the major identified product formed was hydroxyepoxyoctadecenoic acid. On the contrary, the major product formed in the case of saturated monolayers of pure linoleic acid was a mixture of unsubstituted epoxy acids. The inclusion of cholesterol in linoleic acid monolayers increased the rate of disappearance of linoleic acid slightly, whereas cholesteryl acetate decreased the rate. The protective effect exerted by cholesteryl acetate appeared to be similar to that of palmitic acid.

What is Ebola?

On 23 March 2014, the World Health Organization first announced a new Ebola virus outbreak that started in December 2013 in the eastern part of the Republic of Guinea. Human infections shortly emerged in Liberia, Sierra Leone, and Nigeria. On 30 September 2014, the Centers for Disease Control and Prevention confirmed through laboratory testing the first Ebola virus infection diagnosed in the USA, in a patient who travelled from West Africa to Texas. On 6 October 2014, the first human infection occurring outside of Africa was reported, in a Spanish nurse who treated two priests, both of whom died, and on 23 October 2014, the first human infection was reported in New York City. To date, the 2014 Ebola virus outbreak is the longest, largest, and most persistent one since 1976, when the virus was first identified in humans, and the number of human cases exceeded, as of mid-September 2014, the cumulative number of infections from all the previous outbreaks. The early clinical presentation overlaps with other infectious diseases, opening differential diagnosis difficulties. Understanding the transmission routes and identifying the natural reservoir of the virus are additional challenges in studying Ebola hemorrhagic fever outbreaks. Ebola virus is as much a public health challenge for developing countries as it is for the developed world, and previous outbreaks underscored that the relative contribution of the risk factors may differ among outbreaks. The implementation of effective preparedness plans is contingent on integrating teachings from previous Ebola virus outbreaks with those from the current outbreak and with lessons provided by other infectious diseases, along with developing a multifaceted inter-disciplinary and cross-disciplinary framework that should be established and shaped by biomedical as well as sociopolitical sciences.

Political will and international collaborative frameworks in infectious diseases

The last few decades have been marked by a rapid expansion in the world?s population, along with an increasingly dynamic mobility of individuals. This accelerated global inter-connectedness enabled microorganisms to reach virtually any location worldwide more rapidly and efficiently than ever before, reshaping the global dynamics of pathogens. As a result, a local infectious disease outbreak anywhere in the world may almost instantaneously assume global dimensions, and should therefore be considered a global priority. The history of several infectious diseases illustrates that in addition to prophylactic and therapeutic medical interventions, the interplay of social, economic, and political factors makes a fundamental contribution to the outcome of infectious disease outbreaks. Furthermore, this multi- and cross-disciplinary interconnectedness is a key determinant of the outcome of efforts to eradicate vaccine-preventable infectious diseases. A combined framework that incorporates teachings provided by previous outbreaks, and integrates medical and biomedical interventions with contributions made by social, economic, and political factors, emerges as vital requirement of successful global public health initiatives.

Epigenetic therapies - a new direction in clinical medicine

A major biomedical advance from recent years was the finding that gene expression and phenotypic traits may be shaped by potentially reversible and heritable modifications that occur without altering the sequence of the nucleotides, and became known as epigenetic changes. The term 'epigenetics' dates back to the 1940s, when it was first used in context of cellular differentiation decisions that are made during development. Since then, our understanding of epigenetic modifications that govern development and disease expanded considerably. The contribution of epigenetic changes to shaping phenotypes brings at least two major clinically relevant benefits. One of these, stemming from the reversibility of epigenetic changes, involves the possibility to therapeutically revert epigenetic marks to re-establish prior gene expression patterns. The strength and the potential of this strategy are illustrated by the first four epigenetic drugs that were approved in recent years and by the additional candidates that are at various stages in preclinical studies and clinical trials. The second particularity is the finding that epigenetic changes precede the appearance of histopathological modifications. This has the potential to facilitate the emergence of epigenetic biomarkers, some of which already entered the clinical arena, catalysing a major shift in prophylactic and therapeutic strategies, and promising to fill a decades-old gap in preventive medicine.

Streptococcus infantarius and carcinogenesis: a new chapter in colorectal pathology

As mirrored by several topics throughout history, the causal link between infectious diseases and cancer was initially viewed with disbelief and subsequently forgotten, only to be rediscovered decades later, when it started flourishing into a vibrant multidisciplinary field . Just a few years ago, it was estimated that over 20% of all cancers are causally linked to infectious diseases, most frequently caused by bacteria, viruses, and parasites .

H7N9 influenza: something old, something new …

In February 2013, two patients living in Shanghai were admitted to the Shanghai Fifth Hospital with fever, cough and respiratory tract infection, followed by severe pneumonia, respiratory distress and multiorgan dysfunction(1). While the first patient, an 87-year-old man, did not present a history of exposure to live birds during the preceding 2 weeks, the second patient, a 27-year-old man,was a butcher at a market selling live birds. A 35-year-old female from the Anhui Province of China, the third patient who became infected, visited a chicken market a week before her symptoms started (2,3). All three patients died, and their infections did not appear to be epidemiologically linked (4).

The course of D-dimer, high-sensitivity C-reactive protein and pro-B-type natriuretic peptide in patients with non-ST-elevation myocardial infarction

BACKGROUND

Elevated levels of high-sensitivity C-reactive protein (hs-CRP), B-type natriuretic peptide (BNP), and D-dimer each are associated with higher rates of death and recurrent ischemic events in patients with acute myocardial infarction (AMI). The aim of this study was to examine the dynamic course of D-dimer, hs-CRP, and pro-BNP in patients with Non-ST-Elevation Myocardial Infarction (NSTEMI).

METHODS

The study group consisted of 82 patients presenting with symptoms suggestive of acute coronary syndrome (ACS). 40 of the patients were diagnosed as NSTEMI and for the rest AMI was ruled out. Blood was drawn at the time of admission, 6 and 12 hours after that. The samples were tested for hs-CRP, pro-BNP and fibrin D-dimer by a quantitative, point-of-care instrument system (Stratus CS).

RESULTS

D-dimer and pro-BNP did not change between admission and 6 and 12 hours after admission in patients with acute NSTEMI, whereas hs-CRP went down 12 hours after admission compared to the admission value (14.9 +/- 19.4 (mg/mL) v 10.1 +/- 13.5 (mg/mL), p = 0.04).

CONCLUSIONS

There was no dynamic change of D-dimer or pro-BNP during the first 12 hours after admission in patients with acute NSTEMI, whereas hs-CRP decreased 12 hours after admission in these patients.

Ceftobiprole: a new beta-lactam antibiotic

The increasing threat of antimicrobial resistance in general, and that of methicillin-resistant Staphylococcus aureus (MRSA) in particular, is raising significant medical, economical and public health challenges worldwide, both within hospitals and throughout the community. These considerations, along with the extensive time and costs associated with the development and approval of new therapeutic agents, represent some of the major reasons why understanding the advantages and limitations of new antibiotics, ensuring their judicious use and maximising their active shelf life should become global priorities. On March 18, 2008, the Food and Drug Administration issued an approvable letter for ceftobiprole, a broad-spectrum beta-lactam antibiotic active against MRSA and other clinically relevant Gram-positive and Gram-negative pathogens. Ceftobiprole is currently available only for parenteral administration, and besides its remarkable antimicrobial spectrum, this antibiotic possesses additional desirable characteristics, such as low propensity to select for resistance, efficacy in animal models of disease and good safety profile. Furthermore, in recently completed clinical trials, ceftobiprole demonstrated non-inferiority to comparator compounds such as vancomycin, and emerged as a promising clinical option of monotherapy for the treatment of complicated skin and skin structure infections and community-acquired pneumonia. Here, we discuss some of the most important clinically relevant findings on ceftobiprole obtained from in vitro studies, animal models of disease and recently completed phase III clinical trials.

Estrogen-related receptor alpha as a therapeutic target in cancer

The orphan receptor estrogen-related receptor alpha (ERR alpha) is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. This protein is structurally most related to the canonical estrogen receptor and has been shown to modulate estrogen signaling in some contexts. These observations have heightened interest in ERR alpha as a therapeutic target in both breast and ovarian cancer and in other estrogenopathies. This review details our present understanding of ERR alpha action with a view to highlight specific aspects of its signal-transduction pathway in breast cancer that may be amenable to pharmaceutical manipulation.

Cardiovascular exercise and wellness. Exercise training for cardiac rehabilitation patients: meeting the challenges of the millennium

Exercise training for cardiac rehabilitation has evolved over the past decades in response to a growing knowledge base in exercise physiology, an expanding understanding to the knowledge base of coronary disease, and a change in the patients presenting for cardiac rehabilitation. The patient population has changed from a post myocardial infarction patient group, to patients who have had coronary artery revascularization (coronary artery bypass surgery or percutaneous transluminal coronary angioplasty) with the implantation of intraarterial stents. Program goals have evolved from enhancing endurance fitness in deconditioned patients to initiating the long-term adoption of an active exercising lifestyle with the use of strength training to complement endurance training. An increased understanding of behavioral issues in the adoption of an active lifestyle will influence the evolution of cardiac rehabilitation exercise training. During the next several years, it is anticipated that the patient population will change to include patients with significant left ventricular systolic dysfunction and congestive heart failure. The exercise training programs will then further evolve to reflect the successful exercise training formats utilized in the multicenter trials of exercise training for patients with congestive heart failure. (c) 2000 by CHF, Inc.

Cryptogenic ischemic stroke and paradoxical embolism: should a patent foramen ovale be closed? Case report and literature review

Paradoxical embolism is a well-recognized cause of stroke. While the diagnosis in the majority of the cases with a patent foramen ovale is presumptive, numerous treatment strategies have been described. However, there is no single approach that has been overwhelmingly recommended for these patients. A patient is described who presented with ischemic stroke. Transesophageal echocardiography revealed a thrombus that straddled a patent foramen ovale. Anticoagulation with intravenous heparin resulted in resolution of thrombus and neurologic deficit. The literature regarding diagnosis and treatment of paradoxical embolism in the presence of patent foramen ovale is reviewed.

Exercise update 2001

Recent studies addressing the role of exercise in the detection, prevention, and treatment of coronary heart disease have significantly expanded our knowledge base in this area. This therapeutic review is focused on physiologic parameters in exercise, electrocardiogram testing, and the preventive impact of low-intensity regular exercise and the role of exercise training in selected patient populations.

Multi-morphology wide QRS tachycardias in a patient without structural heart disease: an unusual presentation of ventricular tachycardia

Ventricular tachycardia occurs infrequently in patients without structural heart disease. These tachycardias commonly originate from the right ventricular outflow tract. However, the presence of more than one arrhythmogenic substrate in a patient without structural heart disease is rare. We report such a 48-year old patient with no structural heart disease who presented with three morphology wide QRS tachycardia. A brief review of the pathophysiology and management is discussed.

Real-time kinetics of ligand/cell surface receptor interactions in living cells: binding of epidermal growth factor to the epidermal growth factor receptor

We describe a system for extending stopped-flow analysis to the kinetics of ligand capture and release by cell surface receptors in living cells. While most mammalian cell lines cannot survive the shear forces associated with turbulent stopped-flow mixing, we determined that a murine hematopoietic precursor cell line, 32D, is capable of surviving rapid mixing using flow rates as great as 4.0 mL/s, allowing rapid processes to be quantitated with dead times as short as 10 ms. 32D cells do not express any endogenous epidermal growth factor (EGF) receptor or other ErbB family members and were used to establish monoclonal cell lines stably expressing the EGF receptor. Association of fluorescein-labeled H22Y-murine EGF (F-EGF) to receptor-expressing 32D cells was observed by measuring time-dependent changes in fluorescence anisotropy following rapid mixing. Dissociation of F-EGF from EGF-receptor-expressing 32D cells was measured both by chase experiments using unlabeled mEGF and by experiments in which equilibrium was perturbed by dilution. Comparison of these dissociation experiments showed that little, if any, ligand-induced dissociation occurs in the chase dissociation experiments. Data from a series of association and dissociation experiments, performed at various concentrations of F-EGF in the nanomolar range and at multiple cell densities, were simultaneously analyzed using global analysis techniques and fit to a two independent receptor-class model. Our analysis is consistent with the presence of two distinct receptor populations having association rate constants of k(on1) = 8.6 x 10(6) M(-1) s(-1) and k(on2) = 2.4 x 10(6) M(-1) s(-1) and dissociation rate constants of k(off1) = 0.17 x 10(-2) s(-1) and k(off2) = 0.21 x 10(-2) s(-1). The magnitudes of these parameters suggest that under physiological conditions, in which cells are transiently exposed to nanomolar concentrations of ligand, ligand capture and release may function as the first line of regulation of the EGF receptor-induced signal transduction cascade.

Dipyridamole-induced ST-segment elevation indicative of transmural myocardial ischemia--a case report

Dipyridamole nuclear myocardial perfusion test is a safe and effective alternative to exercise nuclear perfusion testing for detecting myocardial ischemia. It is the procedure of choice in selected patients who are unable to exercise adequately. Intravenous dipyridamole causes coronary vasodilation with resultant maldistribution and heterogeneity of coronary flow in the presence of significant coronary artery disease. True ischemia, causing symptoms or ST-segment depression, is uncommon, in part because there is no increase in myocardial oxygen demand. A patient in whom myocardial ischemia developed, manifested by ST-segment elevation, during dipyridamole stress testing is described. Scintigraphic images illustrated a myocardial perfusion defect, which was consistent with coronary angiographic findings. This case report addresses the importance of dipyridamole-induced ST-segment elevation, its correlation with angiographic findings, and the need for continued hemodynamic and electrocardiographic monitoring in patients following dipyridamole infusion.

Cardiovascular risks of sexual activity

The risks associated with sexual activity relate in part to the pathophysiology of the cardiovascular response to sexual activity. This review addresses this subject and reviews studies that directly address the cardiovascular risk associated with sexual activity.

Anterior mitral valve aneurysm: a subaortic complication of aortic valve endocarditis: a case report and review of literature

Mitral valve aneurysm is a rare cause of mitral regurgitation, and is usually associated with aortic valve endocarditis. Prompt diagnosis and early surgical treatment can prevent complications such as embolization and rupture of the aneurysm. The authors report a case of aortic valve endocarditis and mitral valve aneurysm in a patient who initially presented with urinary tract infection.

Adverse effects of herbal treatment of cardiovascular disease: what the physician must know

The increasing use of herbal products by patients with cardiovascular disease represents a clinical challenge to physicians. The use of herbal products is increasing in our society, and less than 50% of patients using herbal products report this information to their physicians. In addition, physicians often lack the knowledge base for herbal medications to effectively counsel patients regarding adverse effects and potential herb-drug interactions. This article reviews Western and traditional Chinese herbs that are commonly used by patients with cardiovascular diseases, herbs noted to have adverse cardiovascular effects, and herbs that may potentially interact with commonly prescribed cardiovascular medications.

An Analytical Approach to the Measurement of Equilibrium Binding Constants: Application to EGF Binding to EGF Receptors in Intact Cells Measured by Flow Cytometry

In ligand binding studies, ligand depletion often limits the accuracy of the results obtained. This problem is approached by employing the simple observation that as the concentration of receptor in the assay is reduced, ligand depletion is also reduced. Measuring apparent K(D)'s of a ligand at multiple concentrations of receptor with extrapolation to infinitely low receptor concentration takes ligand depletion into account and, depending on the binding model employed, yields a K(D) within the defined limits of accuracy. We apply this analysis to the binding of epidermal growth factor (EGF) to the EGF receptor expressed in intact 32D cells, using a homogeneous fluorescein-labeled preparation of EGF and measuring binding by flow cytometry. Binding isotherms were carried out at varying cell densities with each isotherm fit to the generally applied model with two independent binding sites. Examination of the variation in the K(D)'s versus cell density yields a high-affinity site that accounts for 18% of the sites and a lower affinity site that accounts for the remainder. However, further examination of these data suggests that while consistent with each individual isotherm, the simple model of two independent binding sites that is generally applied to EGF binding to the EGF receptor is inconsistent with the changes in the apparent K(D)'s seen across varying cell densities.

Use of intracoronary electrocardiography for detecting ST-T, QTc, and U wave changes during coronary balloon angioplasty

Intracoronary electrocardiography (IC-ECG) is a more sensitive method than surface ECG to detect electrical changes during percutaneous transluminal coronary angioplasty (PTCA). It also provides direct monitoring of ST-T segment, QTc intervals, and U-wave genesis during balloon inflation. These changes are reflective of myocardial ischemia. The authors studied the effect of transient myocardial ischemia on ST-T segment, QTc intervals, and U-wave appearance by comparing standard and perfusion balloon angioplasty. PTCA of left anterior descending artery was performed in 14 patients using the standard balloons and in 11 patients using the perfusion balloons. Patients with perfusion balloon angioplasty had less ST-T elevation (0.15 +/- 0.05 mV versus 1.04 +/- 0.19 mV, P < 0.001), less QTc-shortening intervals (0.01 +/- 0.02 seconds versus -0.05 +/- 0.04 seconds, P < 0.001), and less positive U waves (two versus nine). The authors concluded that balloon angioplasty with perfusion balloons is associated with less ischemia as reflected by ST-T, QTc-shortening intervals, and U-wave changes. There was more positive U-wave appearance with the standard balloon angioplasty, which implies more ischemia. In addition, QTc-shortening intervals are associated with the development of U waves during standard balloon angioplasty. These findings suggest that IC-ECG is a sensitive tool in detecting myocardial ischemia. IC-ECG may also help to clarify the nature of chest pain during PTCA in some patients. Like QT dispersion (QTd), QTc-shortening intervals and new U waves can have prognostic implications and additional studies are needed to define this role.