The cardiovascular implications of omega-3 fatty acids

Nutrition is an important factor in the primary and secondary prevention of cardiovascular disease. Cardiovascular disease is the leading cause of death in North America and the world. Observational studies have generally favoured a beneficial role of n-3 fatty acids in the prevention of heart disease, especially in the prevention of sudden cardiac death. The results of more recent randomised controlled studies, however, have made conclusions regarding the benefit more controversial, with the suggestion of possible harm with fish oil supplementation to those with diagnosed cardiovascular disease. We provide an overview of the results of studies to date and introduce the controversial topics of the omega-6/omega-3 ratio, the public’s concerns regarding ingestion of mercury from marine n-3 sources and the potential role of highly bioactive n-3 metabolites in the process of atherosclerosis. We also provide some general guidelines for the ingestion of n-3 fatty acids that may help clinicians and patients make informed decisions

Novel therapeutic targets for preserving a healthy endothelium: Strategies for reducing the risk of vascular and cardiovascular disease

The endothelium lies in a strategic anatomical position between the circulating blood and the vascular smooth-muscle cells. It is a source of vasodilators such as nitric oxide, prostacyclin, and hyperpolarizing factor as well as heparin-like substances and other molecules with antiproliferative properties. These effects of endothelial cells may explain why platelets and monocytes usually do not adhere at the blood vessel wall. However, under pathological conditions, endothelial dysfunction occurs and significantly contributes to the increase of platelet- -vessel wall interaction, vasoconstriction, pro-inflammation, and proliferation. Under these conditions, endothelium-dependent vasodilation is reduced, and endothelium-dependent constrictor responses are augmented. Upon vessel wall injury, the platelets rapidly adhere to the exposed sub-endothelial matrix, which is mediated by several cellular receptors present on platelets or endothelial cells and various adhesive proteins. Subsequent platelet activation results in the recruitment of additional platelets and the generation of platelet aggregates, so forming a stable platelet plug. Therapeutic strategies aimed at improving or preserving endothelial function therefore may be promising in terms of preventing and treating coronary artery disease. Diagnostic modalities for assessing endothelial function should allow for the early detection of vascular endothelial dysfunction before the manifestation of serious adverse vascular disorders. (Cardiol J 2011; 18, 4: 352–363

The Building of Galactic Disks: Insights from the Triangulum Spiral Galaxy Messier 33

The Triangulum Spiral Galaxy Messier 33 offers unique insights into the building of a galactic disk. We identify spectacular arcs of intermediate age (0.6 Gyr - 2 Gyr) stars in the low-metallicity outer disk. The northern arc spans approx. 120 degrees in azimuth and up to 5 arcmin in width. The arcs are located 2-3 disk scale lengths from the galaxy centre (where 1 disk scale length is equivalent to 0.1 degrees in the V-band) and lie precisely where there is a warp in the HI profile of M33. Warps and infall are inextricably linked (Binney, 1992). We present spectroscopy of candidate stars in the outer northern arc, secured using the Keck I telescope in Hawaii. The target stars have estimated visual magnitudes as faint as V ~ 25m. Absorption bands of CN are seen in all spectra reported in this review talk, confirming their carbon star status. Also presented are PAH emissivity radial profiles generated from IRAC observations of M33 using the Spitzer Space Telescope. A dramatic change of phase in the m=2 Fourier component is detected at the domain of the arcs. M33 serves as an excellent example how the disks of spiral galaxies in our Universe are built: as dynamically open systems, growing from the inward, outward.Comment: Invited review paper presented at IAU Simposium 235, Galaxy Evolution Across the Hubble Time, Prague. To be published by Cambridge University Press, eds. F. Combes & J. Palou

Wpływ kwasów tłuszczowych omega-3 na układ sercowo-naczyniowy

Sposób odżywiania jest ważnym czynnikiem w pierwotnej i wtórnej prewencji chorób sercowo-naczyniowych, które stanowią główny powód zgonów w Ameryce Północnej i na świecie. W badaniach obserwacyjnych dotyczących roli kwasów tłuszczowych omega-3 w prewencji tych schorzeń wykazano ogólnie korzystny wpływ kwasów omega-3, szczególnie w przypadku prewencji nagłej śmierci sercowej. Jednak w późniejszych randomizowanych badaniach korzystne wyniki okazały się bardziej kontrowersyjne, z sugestią możliwych niekorzystnych skutków suplementacji olejów rybnych u osób z rozpoznaną chorobą sercowo-naczyniową. W niniejszej pracy przedstawiono przegląd wyników dotychczasowych badań oraz zaprezentowano kontrowersyjne zagadnienia, takie jak wskaźnik omega-6/omega-3, obawy dotyczące spożywania rtęci z pochodzących z morza źródeł kwasów n-3 oraz potencjalna rola biologicznie wysoko aktywnych metabolitów n-3 w procesie miażdżycy naczyń. Przedstawiono także ogólne zalecenia dotyczące spożycia kwasów tłuszczowych n-3 mogące pomóc klinicystom i pacjentom w podejmowaniu właściwych decyzji

UV-Optical Pixel Maps of Face-On Spiral Galaxies -- Clues for Dynamics and Star Formation Histories

UV and optical images of the face-on spiral galaxies NGC 6753 and NGC 6782 reveal regions of strong on-going star formation that are associated with structures traced by the old stellar populations. We make NUV--(NUV-I) pixel color-magnitude diagrams (pCMDs) that reveal plumes of pixels with strongly varying NUV surface brightness and nearly constant I surface brightness. The plumes correspond to sharply bounded radial ranges, with (NUV-I) at a given NUV surface brightness being bluer at larger radii. The plumes are parallel to the reddening vector and simple model mixtures of young and old populations, thus neither reddening nor the fraction of the young population can produce the observed separation between the plumes. The images, radial surface-brightness, and color plots indicate that the separate plumes are caused by sharp declines in the surface densities of the old populations at radii corresponding to disk resonances. The maximum surface brightness of the NUV light remains nearly constant with radius, while the maximum I surface brightness declines sharply with radius. An MUV image of NGC 6782 shows emission from the nuclear ring. The distribution of points in an (MUV-NUV) vs. (NUV-I) pixel color-color diagram is broadly consistent with the simple mixture model, but shows a residual trend that the bluest pixels in (MUV-NUV) are the reddest pixels in (NUV-I). This may be due to a combination of red continuum from late-type supergiants and [SIII] emission lines associated with HII regions in active star-forming regions. We have shown that pixel mapping is a powerful tool for studying the distribution and strength of on-going star formation in galaxies. Deep, multi-color imaging can extend this to studies of extinction, and the ages and metallicities of composite stellar populations in nearby galaxies.Comment: LaTeX with AASTeX style file, 29 pages with 12 figures (some color, some multi-part). Accepted for publication in The Astrophysical Journa

Impact of varying degrees of renal dysfunction on transcatheter and surgical aortic valve replacement

BackgroundRenal impairment portends adverse outcomes in patients undergoing valvular heart surgery. The relationship between renal dysfunction in patients undergoing transcatheter aortic valve replacement (TAVR) is incompletely understood.MethodsA retrospective review of 1336 patients undergoing surgical aortic valve replacement (SAVR; 2002-2012) and 321 patients undergoing TAVR (2007-2012) was performed. Patients were divided into 3 glomerular filtration rate (GFR) groups: GFR greater than 60 mL/min, GFR 31 to 60 mL/min, and GFR 30 mL/min or less. Logistic and linear regression analysis was performed to estimate the TAVR effect on outcomes. Risk adjustments were made using the Society for Thoracic Surgeons (STS) predicted risk of mortality (PROM).ResultsTAVR patients were older (82 vs 65 years; P < .001), had a poorer ejection fraction (48% vs 53%; P < .001), were more likely female (45% vs 41%; P = .23), and had a higher STS PROM (11.9% vs 4.6%; P < .001). In-hospital mortality rates for TAVR and SAVR were 3.5% and 4.1%, respectively (P = .60), a result that marginally favors TAVR after risk adjustment (adjusted odds ratio = .52, P = .06). In SAVR patients, worsening preoperative renal failure was associated with increased in-hospital mortality (P = .004) and hospital (P < .001) and intensive care unit (ICU) (P < .001) lengths of stay. In contrast, worsening renal function did not influence in-hospital mortality (P = .78) and hospital (P < .23) and ICU (P = .88) lengths of stay in TAVR patients.ConclusionsWorsening renal function was associated with increased in-hospital mortality, hospital length of stay, and ICU length of stay in SAVR patients, but not in TAVR patients. This unexpected finding may have important clinical implications in patients with aortic stenosis and preoperative renal dysfunction