Summary:Purpose: Intractable epilepsy is the focus of much research; however, this concept is defined in no single way. Individual studies use different definitions, creating difficulties for comparisons of results across studies. A head-to-head comparison of definitions could highlight these differences and motivate the development of consensus guidelines.Methods: Within a single prospective study of 613 children in Connecticut with newly diagnosed epilepsy (1993)(1994)(1995)(1996)(1997), six different published definitions or indicators for intractability were applied and compared. All definitions were assessed at various times within the first 5 years after diagnosis, with the exact timing reflecting how they were used in their initial reports. Observed and chance-adjusted agreement (kappa) were computed. The associations of each definition with remission status 7-10 years after diagnosis were quantified with a relative risk.Results: Depending on the specific definition, the epilepsy of 9-24% of children was considered intractable. Observed agreements among the definitions ranged from a low of 0.83 to a high of 0.96. Kappas ranged from low of 0.45 to 0.79. More similar definitions had higher levels of agreement. All definitions were strongly associated with remission status as of last follow-up.Conclusions: Agreement among the different definitions is strong but imperfect. All definitions were significantly associated with longer-term outcome. No single preferred definition of intractable epilepsy exists. Some discussion within the field of epilepsy and a consensus process should be considered as a future step for enhancing comparability of research efforts and clinical guidelines. Consideration should be given to whether a single definition will suit all purposes or whether different types of definitions are needed for different purposes. Key Words: Epilepsy-Intractable-Definition.Although most epilepsy in the population is well controlled, and much of it ultimately remits, intractable or medically refractory epilepsy affects a substantial minority of patients and accounts for a disproportionate amount of resources devoted to care of people with epilepsy. Studying refractory epilepsy requires being able to define and sufficiently make operational the concept for application in a research setting. There is no consensus on how this concept should be made operational for research or clinical purposes. Several investigators have proposed and used various definitions (1-6). Four of these studies were performed in exclusively pediatric cohorts (1-3,5), and two were done in cohorts of mixed ages but focused predominantly on adults (4,6). These definitions have been implemented in studies, most of which examined the risk of refractory epilepsy developing in a variety of settings including population-based, community-based, and clinicbased. Comparison of results from these different studies is hampered, however, by the use of differing definitions.We present a head-on comparison of six different definitions used in t...

Mitochondria have the capacity to integrate environmental signals and, in animals with active stem cell populations, trigger responses in terms of growth and growth form. Colonial hydroids, which consists of feeding polyps connected by tube-like stolons, were treated with avicis, triterpenoid electrophiles whose anti-cancer properties in human cells are mediated in part by mitochondria. In treated hydroids, both oxygen uptake and mitochondrial reactive oxygen species were diminished relative to controls, similar to that observed in human cells exposed to avicins. While untreated colonies exhibit more stolon branches and connections in the centre of the colony than at the periphery, treated colonies exhibit the opposite: fewer stolon branches in the centre of the colony than at the periphery. The resulting growth form suggest an inversion of the normal pattern of colony development mediated by mitochondrial and redox-related perturbations. An as-yet-uncharacterized gradient within the colony may determine the ultimate phenotypic effects of avicin perturbation.

Olividae are marine gastropods living as predators or scavengers on soft sediments. The complex prey handling behaviour of large predatory species includes the storage of food in a pouch formed temporarily by bending and contraction of the posterior foot. Such metapodial pouches had been observed only in Olividae that lack an operculum, prompting the hypothesis that the folding of the metapodium into a pouch biomechanically required the absence of the operculum. Here we report metapodial pouch formation in an operculate olivid, Callianax biplicata (formerly Olivella biplicata). Since the operculum is too small to close the shell aperture in mature C. biplicata, a protective function seems unlikely. The operculum may rather serve as an exoskeletal point for muscle attachment, but may also represent a ‘vestigial organ’ in the process of evolutionary reduction, or an ontogenetic remnant functional at early life stages but not at maturity. Consequently, our observations refute the notion that only inoperculate olivids can form pouches, but not necessarily the idea that the ability to form a metapodial pouch evolved in parallel with operculum reduction

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Building from the works of Jacques Derrida, this article explores health anxiety’s aporetic relationship with medicine through a deconstructive approach. I argue that attention to Derrida’s writings (and in particular, his readings of pharmakon and autoimmunity) may prove useful in explaining the cyclical character of health anxiety and its ambivalent response to medical reassurance. What’s more, I demonstrate how structuralist interpretations of health anxiety as a signifier without referent prove insufficient within a Derridean account. Such a reading emphasizes the need for interdisciplinary medical humanities as well as critical reflections on the possible limitations of Western medical semiotics.