A Pilot Study of Self-Management-based Nutrition and Physical Activity Intervention in Cancer Survivors.

Exercise and a healthy diet are beneficial after cancer, but are not uniformly adopted by cancer survivors. This study reports on the feasibility, acceptability, and effectiveness of a self-management-based nutrition and exercise intervention for Australian cancer survivors. Adult survivors (n  =  25) during curative chemotherapy (stratum 1[S1]; n  =  11) or post-treatment (stratum 2 [S2]; n  =  14) were recruited prospectively from a single center. The Flinders Living Well Self-Management Program™ (FLW Program) was utilized to establish patient-led nutrition and exercise goals and develop a tailored 12-wk intervention plan. Fortnightly reviews occurred with assessments at baseline, 6 and 12 wk. A recruitment and retention rate of 38% and 84% were observed. Both strata maintained total skeletal muscle mass. Small reductions in body mass index, hip circumference, and percentage body fat, and small increases in hand grip strength and exercise capacity among subjects in both strata were observed. No significant differences were observed between strata; however, significant increases in exercise capacity and global health status for S2 were observed from baseline to 12 wk. FLW Program is a feasible mode of delivering nutrition and exercise intervention to cancer survivors and it appears that there are no barriers to implementing this program early during chemotherapy. Hence, the additive effect of gains achieved over a longer duration is promising and this should be explored in randomized controlled trials adequately powered to observe clinically and statistically significant improvements in relevant outcomes.

Is self-management feasible and acceptable for addressing nutrition and physical activity needs of cancer survivors?

BACKGROUND: Self-management is recommended for patients with chronic conditions, but its use with cancer survivors is underexplored. Optimal strategies for achieving lifestyle changes in cancer survivors are not known. OBJECTIVE: We aimed to determine feasibility, acceptability and preliminary efficacy of self-management-based nutrition and physical activity interventions for cancer survivors. DESIGN, SETTING AND PARTICIPANTS: Adult survivors (n = 25) during (Group 1 , n = 11) or post (Group 2, n = 14)-curative chemotherapy for solid tumours, most (n = 20, 80%) with breast cancer, were recruited prospectively from a single clinical centre. INTERVENTION: The Flinders Living Well Self-Management Program, a generic self-management care planning programme, was utilized to establish patient-led nutrition and exercise goals within a tailored 12-week intervention. Fortnightly progress reviews occurred with assessments at baseline, 6 and 12 weeks. RESULTS: Most participants (84%) found the intervention acceptable/very acceptable. Both groups showed a trend towards significant improvement in the self-management capability 'knowledge about changing risk factors' (P = 0.047); Group 2 showed a trend towards significantly improved 'psychological impacts' (P = 0.007). Goal ratings improved for both groups (P = 0.001). Quality of life improved for both groups for emotional functioning (P = 0.03). Physical functioning improved for Group 2 (P = 0.05); however, most symptom domains worsened for Group 1, as expected given their treatment stage. DISCUSSION AND CONCLUSIONS: Self-management interventions are feasible for this population. In particular, building self-management capacity during the active phase of patients' cancer treatment provides health and psychosocial benefits. Larger randomized controlled trials are required to further determine efficacy. Further translational research is also needed to determine acceptability,feasibility, enablers and barriers for clinicians embedding this approach into routine cancer survivorship care.

Epigonal conditioned media from bonnethead shark, Sphyrna tiburo, induces apoptosis in a T-cell leukemia cell line, Jurkat E6-1.

Representatives of Subclass Elasmobranchii are cartilaginous fish whose members include sharks, skates, and rays. Because of their unique phylogenetic position of being the most primitive group of vertebrates to possess all the components necessary for an adaptive immune system, the immune regulatory compounds they possess may represent the earliest evolutionary forms of novel compounds with the potential for innovative therapeutic applications. Conditioned medium, generated from short term culture of cells from the epigonal organ of bonnethead sharks (Sphyrna tiburo), has been shown to have potent reproducible cytotoxic activity against a variety of human tumor cell lines in vitro. Existing data suggest that epigonal conditioned medium (ECM) exerts this cytotoxic activity through induction of apoptosis in target cells. This manuscript describes apoptosis induction in a representative tumor cell line, Jurkat E6-1, in response to treatment with ECM at concentrations of 1 and 2 mg/mL. Data indicate that ECM exposure initiates the mitochondrial pathway of apoptosis through activation of caspase enzymes. Future purification of ECM components may result in the isolation of an immune-regulatory compound with potential therapeutic benefit for treatment of human cancer.

Cellular metabolism of brevetoxin (PbTx-2) by a monocyte cell line (U-937).

Blooms of Karenia brevis produce brevetoxins which cause neurotoxic shellfish poisoning and respiratory symptoms in humans as well as harmful effects on sea life. To investigate potential effects of brevetoxins on immune system components, a monocyte cell line (U-937) was exposed in vitro to PbTx-2. U-937 cells metabolized PbTx-2 through cellular detoxification mechanisms, as evidenced by depletion of intracellular glutathione and formation of glutathione and cysteine conjugates. Total intracellular glutathione was significantly decreased in toxin-treated cells compared to control cells, as measured using an enzymatic recycling method. LC/MS was used to detect the following brevetoxin metabolites: a cysteine-PbTx-2 conjugate (m/z 1018) and two putative glutathione-PbTx-2 conjugates (m/z 1204 and 1222). During 3h incubation, glutathione conjugates were detectable as early as 1h and increased in concentration after 2 and 3h. A cysteine-PbTx-2 conjugate appeared after 2h and increased in concentration after 3h. Detectable levels of brevetoxin conjugates were present in response to toxin concentrations of 1muM. Depletion of intracellular glutathione and formation of brevetoxin metabolites, with changes in concentrations over time, suggest immune cells (U-937) have important cellular detoxification pathways for PbTx-2.

Effects of in vitro brevetoxin exposure on apoptosis and cellular metabolism in a leukemic T cell line (Jurkat).

Harmful algal blooms (HABs) of the toxic dinoflagellate, Karenia brevis, produce red tide toxins, or brevetoxins. Significant health effects associated with red tide toxin exposure have been reported in sea life and in humans, with brevetoxins documented within immune cells from many species. The objective of this research was to investigate potential immunotoxic effects of brevetoxins using a leukemic T cell line (Jurkat) as an in vitro model system. Viability, cell proliferation, and apoptosis assays were conducted using brevetoxin congeners PbTx-2, PbTx-3, and PbTx-6. The effects of in vitro brevetoxin exposure on cell viability and cellular metabolism or proliferation were determined using trypan blue and MTT (1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan), respectively. Using MTT, cellular metabolic activity was decreased in Jurkat cells exposed to 5 - 10 microg/ml PbTx-2 or PbTx-6. After 3 h, no significant effects on cell viability were observed with any toxin congener in concentrations up to 10 microg/ml. Viability decreased dramatically after 24 h in cells treated with PbTx-2 or -6. Apoptosis, as measured by caspase-3 activity, was significantly increased in cells exposed to PbTx-2 or PbTx-6. In summary, brevetoxin congeners varied in effects on Jurkat cells, with PbTx-2 and PbTx-6 eliciting greater cellular effects compared to PbTx-3.

Effects of brevetoxin exposure on the immune system of loggerhead sea turtles.

Blooms of the toxic dinoflagellate, Karenia brevis, occur almost annually off the Florida coast. These blooms, commonly called "red tides", produce a group of neurotoxins collectively termed brevetoxins. Many species of sealife, including sea turtles, are severely impacted by brevetoxin exposure. Effects of brevetoxins on immune cells were investigated in rescued loggerhead sea turtles, Caretta caretta, as well as through in vitro experiments using peripheral blood leukocytes (PBL) collected from captive sea turtles. In rescued animals, plasma brevetoxin concentrations were measured using a competitive ELISA. Plasma lysozyme activity was measured using a turbidity assay. Lysozyme activity correlated positively with plasma brevetoxin concentrations. Differential expression of genes affected by brevetoxin exposure was determined using two separate suppression subtractive hybridization experiments. In one experiment, genes from PBL collected from sea turtles rescued from red tide toxin exposure were compared to genes from PBL collected from healthy captive loggerhead sea turtles. In the second experiment, PBL from healthy captive loggerhead sea turtles were exposed to brevetoxin (500 ng PbTx-2/ml) in vitro for 18 h and compared to unexposed PBL. Results from the subtraction hybridization experiment conducted with red tide rescued sea turtle PBL indicated that genes involved in oxidative stress or xenobiotic metabolism were up-regulated. Using quantitative real-time PCR, a greater than 2-fold increase in superoxide dismutase and thioredoxin and greater than 10-fold increase in expression of thiopurine S-methyltransferase were observed. Results from the in vitro subtraction hybridization experiment indicated that genes coding for cytochrome c oxidases were the major up-regulated genes. Using quantitative real-time PCR, a greater than 8-fold increase in expression of beta-tubulin and greater than 3-fold increase in expression of ubiquinol were observed. Brevetoxin exposure may have significant implications for immune function in loggerhead sea turtles.

The EF-G-like GTPase Snu114p regulates spliceosome dynamics mediated by Brr2p, a DExD/H box ATPase.

Binding of a pre-mRNA substrate triggers spliceosome activation, whereas the release of the mRNA product triggers spliceosome disassembly. The mechanisms that underlie the regulation of these rearrangements remain unclear. We find evidence that the GTPase Snu114p mediates the regulation of spliceosome activation and disassembly. Specifically, both unwinding of U4/U6, required for spliceosome activation, and disassembly of the postsplicing U2/U6.U5.intron complex are repressed by Snu114p bound to GDP and derepressed by Snu114p bound to GTP or nonhydrolyzable GTP analogs. Further, similar to U4/U6 unwinding, spliceosome disassembly requires the DExD/H box ATPase Brr2p. Together, our data define a common mechanism for regulating and executing spliceosome activation and disassembly. Although sequence similarity with EF-G suggests Snu114p functions as a molecular motor, our findings indicate that Snu114p functions as a classic regulatory G protein. We propose that Snu114p serves as a signal-dependent switch that transduces signals to Brr2p to control spliceosome dynamics.