A systematic review of the impact of postoperative aerobic exercise training in patients undergoing surgery for intra-abdominal cancers

INTRODUCTION

Enhanced recovery after surgery (ERAS) programmes which advocate early mobility after surgery have improved immediate clinical outcomes for patients undergoing abdominal cancer resections with curative intent. However, the impact of continued physical activity on patient-related outcomes and functional recovery is not well defined. The aim of this review was to assess the impact of postoperative aerobic exercise training, either alone or in conjunction with another exercise modality, on patients who have had surgery for intra-abdominal cancer.

METHODS

A literature search was performed of electronic journal databases. Eligible papers needed to report an outcome of aerobic capacity in patients older than 18 years of age, who underwent cancer surgery with curative intent and participated in an exercise programme (not solely ERAS) that included an aerobic exercise component starting at any point in the postoperative pathway up to 12 weeks.

RESULTS

Eleven studies were deemed eligible for inclusion consisting of two inpatient, one mixed inpatient/outpatient and eight outpatient studies. Meta-analysis of four outpatient studies, each reporting change in 6-min walk test (6MWT), showed a significant improvement in 6MWT with exercise (MD 74.92 m, 95% CI 48.52-101.31 m). The impact on health-related quality of life was variable across studies.

CONCLUSION

Postoperative exercise confers benefits in improving aerobic function post surgery and can be safely delivered in various formats (home-based or group/supervised).

Optimal numbers of matings: the conditional balance between benefits and costs of mating for females of a nuptial gift-giving spider

In species where females gain a nutritious nuptial gift during mating, the balance between benefits and costs of mating may depend on access to food. This means that there is not one optimal number of matings for the female but a range of optimal mating numbers. With increasing food availability, the optimal number of matings for a female should vary from the number necessary only for fertilization of her eggs to the number needed also for producing these eggs. In three experimental series, the average number of matings for females of the nuptial gift-giving spider Pisaura mirabilis before egg sac construction varied from 2 to 16 with food-limited females generally accepting more matings than well-fed females. Minimal level of optimal mating number for females at satiation feeding conditions was predicted to be 2-3; in an experimental test, the median number was 2 (range 0-4). Multiple mating gave benefits in terms of increased fecundity and increased egg hatching success up to the third mating, and it had costs in terms of reduced fecundity, reduced egg hatching success after the third mating, and lower offspring size. The level of polyandry seems to vary with the female optimum, regulated by a satiation-dependent resistance to mating, potentially leaving satiated females in lifelong virginity.

Identification of a sex pheromone from a spider

The compounds (R)-3-hydroxybutyric acid and its dimer, (R)-3-[(R)-3-hydroxybutyryloxy]-butyric acid, have been identified as sex pheromones of a spider. These compounds elicit web reduction behavior by males of Linyphia triangularis (Clerck) on the webs of unmated adult females.

Activities of Glutathione S-Transferase and Glutathione Peroxidases Related to Diet Quality in an Aphid Predator, the Seven-spot Ladybird, Coccinella septempunctata L. (Coleoptera: Coccinellidae(

Larvae of Coccinella septempunctata were reared on three aphid diets, consisting of pure Rhopalosiphum padi, pure Metopolophium dirhodum, and an equal mix of these aphid species. In the pupal stage, the activities of three detoxifying enzyme systems - glutathione S-transferase (GST) with 1-chloro-2,4-dinitrobenzene as substrate, glutathione peroxidase with hydrogen peroxide as substrate (GSH-Px[H2O2]), and glutathione peroxidase with tert-butyl hydroperoxide as substrate (GSH-Px[TBH]) - were assayed. Growth rate, measured as the total protein content of the pupae, was significantly higher in the mixed-diet group than in the R. padi group, whereas that of the M. dirhodum group was intermediate. GST showed lower activity in larvae on a pure R. padi diet and a mixed aphid diet than on a pure M. dirhodum diet, whereas the variation in GSH-Px[TBH] was independent of diet. GSH-Px(H2O2) showed a significantly higher activity in the R. padi group than in the M. dirhodum group, whereas that of the mixed-diet group was intermediate. Thus, feeding on the low-quality aphid, R. padi, inhibited GST and activated GSH-Px(H2O2). The induction of GSH-Px[H2O2] indicated elevated oxidative stress. This may have been caused by toxic compounds in the R. padi.

Self-injection of a dipteran parasitoid into a spider

A host invasion strategy hitherto unknown from other insect parasitoids was observed in the dipteran Acrocera orbicula (Fabricius) (Diptera: Acroceridae) parasitizing the wolf spider, Pardosa prativaga (L. Koch) (Araneida: Lycosidae). In laboratory experiments the free-living first instar acrocerid larvae attached themselves firmly to the spiders' integument by the mouthparts, cutting a tiny hole through the integument. No first instar larvae invaded the host. A week later the parasitoids molted, and a small, flexible, and glabrous second instar larva left each of the attached first instar exuviae and invaded the host through the attachment hole of the first instar larva. The novel host invasion pattern observed may reduce physical damage to the host in the initial phase of endoparasitism, enhancing parasitoid survival.