Interaction between natural killer cells and regulatory T cells: perspectives for immunotherapy

Regulatory T (Treg) cells and natural killer (NK) cells are key players in the immune system. The interaction between these two cell types has been reported to be beneficial in healthy conditions such as pregnancy. However, in the case of certain pathologies such as autoimmune diseases and cancer this interaction can become detrimental, as Treg cells have been described to suppress NK cells and in particular to impair NK cell effector functions. This review aims to discuss the recent information on the interaction between Treg cells and NK cells under healthy and pathologic conditions, to describe the specific conditions in which this interaction takes place, the effect of Treg cells on hematopoietic stem cell differentiation and the consequences of this interaction on the optimization of immunotherapeutic protocols.     

Successful Percutaneous Closure of a Ruptured Saphenous Vein Graft Aneurysm

A 68-year-old man with previous coronary artery bypass surgery presented with acute onset chest pain. After ruling out an acute coronary syndrome, a computed tomography scan demonstrated a giant aneurysm (10 cm × 8 cm) of the right coronary artery saphenous vein graft (SVG) with signs of rupture into the mediastinum. An Amplatzer Vascular Plug II was successfully deployed at the proximal anastomosis of the SVG, achieving complete exclusion. At 6-month follow-up the patient remained asymptomatic and a computed tomography scan confirmed adequate position of the device. Amplatzer Vascular Plug II is a reasonable alternative for SVG aneurysm closure, providing the vein graft supplies nonviable myocardium.     

Sample size: how many participants do I need in my research?

The importance of estimating sample sizes is rarely understood by researchers, when planning a study. This paper aims to highlight the centrality of sample size estimations in health research. Examples that help in understanding the basic concepts involved in their calculation are presented. The scenarios covered are based more on the epidemiological reasoning and less on mathematical formulae. Proper calculation of the number of participants in a study diminishes the likelihood of errors, which are often associated with adverse consequences in terms of economic, ethical and health aspects.     

Cellular senescence determines endothelial cell damage induced by uremia

Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells.     

Narrow-diameter implants: Are they a predictable treatment option? A literature review

Objective: To evaluate the predictability of narrow-diameter implants as a treatment option in routine clinical practice. A literature review was performed of studies reporting clinical results obtained with these implants. Survival rates, peri-implant bone loss and related complications were evaluated. The working hypothesis was that narrow-diameter implants offer clinical results similar to those obtained with implants of greater diameter. Material and Methods: A Medline-PubMed search covering the period between 2002 and 2012 was carried out. Studies published in English and with a follow-up period of at least 12 months were considered for inclusion. A manual search was also conducted in different journals with an important impact factor. Results: Twenty-one studies meeting the screening criteria were included in the literature review. A total of 2980 narrow-diameter implants placed in 1607 patients were analyzed. Conclusions: The results obtained from the literature indicate that narrow-diameter implants are a predictable treatment option, since they afford clinical results comparable to those obtained with implants of greater diameter. Key words:Narrow implant, survival rate, peri-implant bone loss, related complications.