Comparative three-dimensional jaw muscle anatomy of marsupial carnivores (Dasyurus spp.) and the termite-eating numbat (Myrmecobius fasciatus).

Among marsupials, the endangered numbat (Myrmecobius fasciatus) is the only obligate myrmecophage with a diet comprised strictly of termites. Like many other specialised myrmecophagous mammals, numbats have a gracile and highly specialised skull morphology with an elongated rostrum and small braincase. Myrmecobiidae is one of four taxonomic families within the Australasian marsupial order Dasyuromorphia, and to date, the muscular anatomy of any member of this group is relatively poorly known. We utilised microdissection and contrast-enhanced microcomputed tomography scanning to provide the first comprehensive qualitative and quantitative descriptions of jaw muscle anatomy in numbats and quolls (Dasuyrus species). The arrangement of the jaw muscles across these species was conservative, both in gross anatomy and muscle proportions, corresponding to a 'generalised' mammalian pattern. In contrast to Dasyurus, the jaw muscles of the numbat were greatly reduced. Many aspects of the muscle anatomy of the numbat were similar to patterns reported in other myrmecophagous species, particularly a greatly reduced temporalis muscle. Unusually, the digastric muscle in the numbat was comprised of a single, large anterior belly while the posterior belly was absent. We propose that the enlarged anterior belly of the digastric may be linked to jaw stabilisation and coordination of tongue movements during feeding. The lateral insertion and fascial connection of the digastric to the tongue in numbats may also aid in distributing stress evenly across the jaw and minimise muscle fatigue. The muscle descriptions and three-dimensional models provided in this study will facilitate further analysis of musculoskeletal adaptation and evolution within the Dasyuromorphia.

Aerobic exercise during chemotherapy infusion for cancer treatment: a novel randomised crossover safety and feasibility trial.

PURPOSE: Exercise is a powerful adjunct therapy for patients diagnosed with cancer which can alleviate treatment side-effects and improve a range of outcomes including fatigue and health-related quality of life. Recently, preclinical evidence has suggested that if exercise is performed during chemotherapy infusion, there is enhanced perfusion that may improve drug delivery and attenuate the hypoxic microenvironment. This study aimed to determine the safety and feasibility of delivering an aerobic exercise intervention to cancer patients during chemotherapy infusion. METHODS: A randomised crossover trial was conducted for adults (18-60) undergoing chemotherapy treatment with non-vesicant agents for cancer. In randomised order, during two consecutive chemotherapy infusions, participants either received usual care or performed 20 min of supervised low-intensity cycling. RESULTS: Sixty-five percent of patients approached agreed to participate, and exercise was safely delivered with neither adverse events nor interference to treatment reported for all participants with a mixed cancer diagnosis (N = 10, 90% female, 51.2 ± 7.4 years). There were no significant differences between exercise and usual care in participant-reported difficulty or comfort levels, but exercise significantly reduced boredom (p = 0.01). No significant differences were detected in the symptoms experienced following either intervention. CONCLUSIONS: Exercise during chemotherapy infusion appears to be safe and feasible. Further research is required with a larger sample size to evaluate the impact on tumour perfusion, symptom experience, and opportunity for physical activity increase.