A molecular analysis of desiccation tolerance mechanisms in the anhydrobiotic nematode Panagrolaimus superbus using expressed sequenced tags

<p>Abstract</p> <p>Background</p> <p>Some organisms can survive extreme desiccation by entering into a state of suspended animation known as anhydrobiosis. <it>Panagrolaimus superbus </it>is a free-living anhydrobiotic nematode that can survive rapid environmental desiccation. The mechanisms that <it>P. superbus </it>uses to combat the potentially lethal effects of cellular dehydration may include the constitutive and inducible expression of protective molecules, along with behavioural and/or morphological adaptations that slow the rate of cellular water loss. In addition, inducible repair and revival programmes may also be required for successful rehydration and recovery from anhydrobiosis.</p> <p>Results</p> <p>To identify constitutively expressed candidate anhydrobiotic genes we obtained 9,216 ESTs from an unstressed mixed stage population of <it>P. superbus</it>. We derived 4,009 unigenes from these ESTs. These unigene annotations and sequences can be accessed at <url>http://www.nematodes.org/nembase4/species_info.php?species=PSC</url>. We manually annotated a set of 187 constitutively expressed candidate anhydrobiotic genes from <it>P. superbus</it>. Notable among those is a putative lineage expansion of the <it>lea </it>(late embryogenesis abundant) gene family. The most abundantly expressed sequence was a member of the nematode specific <it>sxp/ral-2 </it>family that is highly expressed in parasitic nematodes and secreted onto the surface of the nematodes' cuticles. There were 2,059 novel unigenes (51.7% of the total), 149 of which are predicted to encode intrinsically disordered proteins lacking a fixed tertiary structure. One unigene may encode an exo-β-1,3-glucanase (GHF5 family), most similar to a sequence from <it>Phytophthora infestans</it>. GHF5 enzymes have been reported from several species of plant parasitic nematodes, with horizontal gene transfer (HGT) from bacteria proposed to explain their evolutionary origin. This <it>P. superbus </it>sequence represents another possible HGT event within the Nematoda. The expression of five of the 19 putative stress response genes tested was upregulated in response to desiccation. These were the antioxidants <it>glutathione peroxidase, dj-1 </it>and <it>1-Cys peroxiredoxin</it>, an <it>shsp </it>sequence and an <it>lea </it>gene.</p> <p>Conclusions</p> <p><it>P. superbus </it>appears to utilise a strategy of combined constitutive and inducible gene expression in preparation for entry into anhydrobiosis. The apparent lineage expansion of <it>lea </it>genes, together with their constitutive and inducible expression, suggests that LEA3 proteins are important components of the anhydrobiotic protection repertoire of <it>P. superbus</it>.</p

A randomized controlled trial of a group acceptance-based intervention for cancer survivors experiencing anxiety at re-entry (‘Valued Living’): study protocol

Abstract Background Anxiety is a common concern of cancer survivors during the transition from active cancer treatment to cancer survivorship (the re-entry phase). This paper presents the study protocol for a novel group-based behavioral intervention to improve mental health, well-being, and medical use outcomes among anxious cancer survivors at re-entry. Methods/Design This two-armed, prospective randomized controlled trial will randomize a minimum of 100 re-entry-phase cancer survivors with moderate to high anxiety to the intervention or a usual care control condition. The intervention is delivered in a group format over 7 weeks; content is based on Acceptance and Commitment Therapy (ACT), an acceptance, mindfulness, and values-based intervention. Participants will be recruited from community cancer care centers and the intervention will be led by the onsite clinical social workers. Participants will be assessed at baseline, mid-intervention, post-intervention, and 3- and 6-month follow-up. ACT participants will complete process measures before the beginning of group sessions 2, 4, and 6; all participants will complete the process measures during the regular assessments. The primary outcome is anxiety symptoms; secondary outcomes include anxiety disorder severity, fear of recurrence, depressive symptoms, cancer-related trauma symptoms, sense of life meaning, vitality/fatigue, and medical utilization. Discussion This clinical trial will provide valuable evidence regarding the efficacy of the group ACT intervention in community oncology settings. Trial registration Clinicaltrials.gov NCT02550925