Eliminating the effects of motion during radiofrequency lesion delivery using a novel contact-force controller.

INTRODUCTION: Catheter-tissue contact force is a determinant of radiofrequency (RF) ablation lesion effectiveness. However, ablation on a beating heart is subject to force variability, making it difficult to optimally deliver consistently durable and transmural lesions. This work evaluates improvements in contact force stability and lesion reproducibility by using a catheter contact-force controller (CFC) during lesion delivery in vitro and in vivo. METHODS AND RESULTS: Using a sheath and force-sensing catheter, an experienced operator attempted to maintain a constant force of 20 g at targets within the atria and left ventricle of a pig manually and using the CFC; the average force and contact-force variation (CFV) achieved using each approach were compared. Ablation lesions (20 W, 30 seconds, 17 mL/min irrigation) were created in bovine tissue samples mounted on a platform programmed to reproduce clinically relevant motion. CFC-assisted lesions were delivered to stationary and moving tissue with forces of 5 to 35  g. Mimicking manual intervention, lesions were also delivered to moving tissue while the CFC was disabled. Resultant lesion volumes were compared using two-way analysis of variance. When using the CFC, the average force was within 1 g of the set level, with a CFV less than 5 g, during both in vitro and in vivo experiments. Reproducible and statistically identical (P = .82) lesion volumes proportional to the set force were achieved in both stationary and moving tissue when the CFC was used. CONCLUSIONS: CFC assistance maintains constant force in vivo and removes effect of motion on lesion volume during RF lesion delivery

Elucidating the Mechanisms of Influenza Virus Recognition by Ncr1

Natural killer (NK) cells are innate cytotoxic lymphocytes that specialize in the defense against viral infection and oncogenic transformation. Their action is tightly regulated by signals derived from inhibitory and activating receptors; the later include proteins such as the Natural Cytotoxicity Receptors (NCRs: NKp46, NKp44 and NKp30). Among the NCRs, NKp46 is the only receptor that has a mouse orthologue named Ncr1. NKp46/Ncr1 is also a unique marker expressed on NK and on Lymphoid tissue inducer (LTI) cells and it was implicated in the control of various viral infections, cancer and diabetes. We have previously shown that human NKp46 recognizes viral hemagglutinin (HA) in a sialic acid-dependent manner and that the O-glycosylation is essential for the NKp46 binding to viral HA. Here we studied the molecular interactions between Ncr1 and influenza viruses. We show that Ncr1 recognizes influenza virus in a sialic acid dependent manner and that N-glycosylation is important for this binding. Surprisingly we demonstrate that none of the predicted N-glycosilated residues of Ncr1 are essential for its binding to influenza virus and we thus conclude that other, yet unidentified N-glycosilated residues are responsible for its recognition. We have demonstrated that N glycosylation play little role in the recognition of mouse tumor cell lines and also showed the in-vivo importance of Ncr1 in the control of influenza virus infection by infecting C57BL/6 and BALB/c mice knockout for Ncr1 with influenza

The Natural Cytotoxicity Receptors in Health and Disease

The Natural Cytotoxicity Receptors (NCRs), NKp46, NKp44, and NKp30, were some of the first human activating Natural Killer (NK) cell receptors involved in the non-MHC-restricted recognition of tumor cells to be cloned over 20 years ago. Since this time many host- and pathogen-encoded ligands have been proposed to bind the NCRs and regulate the cytotoxic and cytokine-secreting functions of tissue NK cells. This diverse set of NCR ligands can manifest on the surface of tumor or virus-infected cells or can be secreted extracellularly, suggesting a remarkable NCR polyfunctionality that regulates the activity of NK cells in different tissue compartments during steady state or inflammation. Moreover, the NCRs can also be expressed by other innate and adaptive immune cell subsets under certain tissue conditions potentially conferring NK recognition programs to these cells. Here we review NCR biology in health and disease with particular reference to how this important class of receptors regulates the functions of tissue NK cells as well as confer NK cell recognition patterns to other innate and adaptive lymphocyte subsets. Finally, we highlight how NCR biology is being harnessed for novel therapeutic interventions particularly for enhanced tumor surveillance

Encounters in the Looking-glass of Time: Longitudinal Contribution of a Life Story Workshop to the Dialogue between Jewish and Arab Young adults in Israel

The field of encounter groups between Jews and Arabs in Israel is commonly discussed in academia; nevertheless, despite the multitude of studies that deal with encounter groups, longitudinal research in this area is very limited in the literature. The purpose of this article is to pinpoint, the contributions of an encounter group that was researched over a long period of time. The article describes the results of a four year longitudinal, qualitative study of a group of Jewish and Arab university students. Initially all of the students took part in a year-long encounter group workshop that was based on the “life story model”. We recognized that our students went through a process during the seminar and the next few years that followed it. Based on the analyses of interviews with the participants we have created a four stage model that we would like to suggest as a means for examining participants processes in the looking glass of time. We discuss the contributions as well as problematic aspects of the life story” method and suggest recommendations and implication for future experience with this method in different contexts and groups

Within-Group Variance as a Facilitator of Dialogue : A Jewish-Arab Israeli Encounter Group Focused on Family Stories

Since October 2000, there has been a great increase in tension between Arabs and Jews in Israel. Recent surveys show that approximately forty percent of Jews in Israel support the prospect of removal of Arabs by their government from the State of Israel. It is clear that the media contributes to a negative and polarized presentation of Arabs and Jews in Israel through its coverage of the Israeli-Palestinian conflict. The present article shows that when a suitable context is created, this polarized negativity still exists but is not the sole model of discourse between Jewish and Arab citizens of Israel. The article describes patterns of dialogue developed in a group of eight Jewish and nine Arab students who met together for a year for a workshop entitled, “Life Stories as a Means Toward Co-Existence," led by the first and third authors. Each student interviewed two family members, one from his or her parents' generation, and one from his/her grandparents' generation. The discussions in the seminar fluctuated between mutual inclusion and political confrontations. Both withinand between-group variance emerged among Jewish and Arab participants while listening to the stories. Two basic types of stories were created, those that were “good enough" to be accepted by most of the other group's participants, and those that were “bad enough" and thus rejected by the other side. The article describes the stories told in the group and analyzes the components of “good" and “bad" enough stories. It then examines the contribution of life stories and the attendant model to creation of intra-group dialogue, in marked contrast to the threatening and violent external context

Beliefs Predicting Peace, Beliefs Predicting War: Jewish Americans and the Israeli-Palestinian Conflict

Jewish Americans' opinions on the Israeli-Palestinian conflict influence both the Israeli and the U.S. governments. Consequently, the Jewish American diaspora can act to promote or inhibit the peace process between Israelis and Palestinians. Several different sociopsychological beliefs have been postulated to lead individuals to support the perpetuation of conflict. Among these beliefs are a sense of collective victimhood, dehumanization and delegitimization of the other side, a zero-sum view on the conflict, and a monolithic narrative about the conflict. In this exploratory study we examined the role of these beliefs in predicting Jewish Americans' rejection or support of compromise solutions to the Israeli-Palestinian conflict. A survey study of 176 Jewish Americans shows that a monolithic view on the conflict, dehumanizing and delegitimizing of the other side, and a zero-sum view on the conflict played an important role in predicting opposition to compromise solutions for the Palestinian-Israeli conflict. Beliefs about collective victimhood did not predict support for compromise solutions. Findings are discussed in terms of the centrality of narrative misrecognition in preventing agreement to concessions toward the other side. © 2013 The Society for the Psychological Study of Social Issues