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This study investigated the effect of various histotripsy dosages on tumor cell kill and associated bleeding in two murine brain tumor models (glioma [Gl261] and lung metastasis [LL/2-Luc2]). GL261 or LL/2-Luc2 cells were cultured and implanted into the brains of C57BL/6 mice. Histotripsy (1-cycle pulses, 5 Hz PRF, 30 MPa-P) was performed using a 1 MHz transducer for five different dosages for each cell line: 5, 20 or 200 pulses per location (PPL) at a single treatment point, or 5 or 10–20 PPL at multiple treatment points. MRI, bioluminescence imaging and histology were used to assess tumor ablation and treatment effects within 4–6 h post-treatment. All treatment groups resulted in a reduction of BLI intensity for the LL/2-Luc2 tumors, with significant signal reductions for the multi-point groups. The average pre-/post-treatment BLI flux (photons/s, ×108) for the different treatment groups were: 4.39/2.19 (5 PPL single-point), 5.49/1.80 (20 PPL single-point), 3.86/1.73 (200 PPL single-point), 2.44/1.11 (5 PPL multi-point) and 5.85/0.80 (10 PPL multi-point). MRI and H&E staining showed increased tumor damage and hemorrhagic effects with increasing histotripsy dose for both GL261 and LL/2-Luc2 tumors, but the increase in tumor damage was diminished beyond 10–20 PPL for single-point treatments and outweighed by increased hemorrhage. In general, hemorrhage was confined to be within 1 mm of the treatment boundary for all groups. Our results suggest that a lower number of histotripsy pulses at fewer focal locations can achieve substantial tumor kill while minimizing hemorrhage. [ABSTRACT FROM AUTHOR]

Strand-feeding is a unique foraging technique used by Atlantic bottlenose dolphins (Tursiops truncatus (Montagu, 1821)) in salt marshes of the southeastern USA wherein a group of dolphins rushes a creek bank, temporarily stranding themselves to capture fish that have been pushed ashore by their bow wave. Wading birds are attracted to these events to forage on stranded fish. We hypothesized that birds foraging in association with dolphins experience greater foraging efficiency than birds foraging away from dolphins and that some birds are able to meet their entire daily metabolic needs by foraging at strand-feeding events. The species composition, abundance, and foraging success of birds at 569 strand- feeding events were compared with the same parameters from marsh surveys of birds not associated with dolphins. Only Great Egrets (Ardea alba L., 1758) were proportionately more common at strand-feeding events than in the marsh overall (p < 0.001). During peak strand-feeding hours, energy intake per hour was higher for Great Egrets foraging with strand- feeding dolphins than for birds foraging away from dolphins (p = 0.04). Bioenergetic models indicated that prey intake by Great Egrets at strand-feeding events was sufficient to meet their existence and likely their active metabolic requirements. Key words: strand-feeding, bottlenose dolphin, Tursiops truncatus, Great Egret, Ardea alba, Great Blue Heron, Ardea herodias, foraging, energetics, commensalism. La chasse par echouage est une technique d'alimentation particuliere aux grands dauphins (Tursiops truncatus (Montagu, 1821)) dans les marais sales du sud-est des Etats-Unis, selon laquelle un groupe de dauphins se rue vers les berges d'une crique pour s'y echouer provisoirement afin d'y capturer les poissons pousses vers la rive par leur vague d'avant. Les echassiers sont attires vers les lieux de telles activites pour s'y nourrir de poissons echoues. Nous avons postule que la quete de nourriture des oiseaux qui se nourrissent en association avec les dauphins est plus efficace que celle d'oiseaux qui se nourrissent a distance des dauphins et que certains oiseaux peuvent satisfaire tous leurs besoins metaboliques quotidiens en se nourrissant dans des sites de chasse par echouage. La composition specifique, l' abondance d'oiseaux et le succes de la quete de nourriture d'oiseaux dans 569 sites de chasse par echouage ont ete compares a ces memes parametres obtenus de releves d'oiseaux de marais non associes a des dauphins. Seules les grandes aigrettes (Ardea alba L., 1758) se sont averees proportionnellement plus abondantes dans les sites de chasse par echouage que dans les marais en general (p < 0,001). Durant les heures de pointe de chasse par echouage, l'apport energetique horaire etait plus eleve pour les grandes aigrettes se nourrissant dans des sites de chasse par echouage que pour les oiseaux se nourrissant a distance des dauphins (p = 0,04). Des modeles bioenergetiques indiquent que la consommation de proies par les grandes aigrettes aux sites de chasse par echouage est suffisante pour assurer leur subsistance et, vraisemblablement, maintenir un metabolisme actif. Mots-cles : chasse par echouage, grand dauphin, Tursiops truncatus, grande aigrette, Ardea alba, grand heron, Ardea herodias, quete de nourriture, energetique, commensalisme. [Traduit par la Redaction], Introduction Atlantic bottlenose dolphins (Tursiops truncatus (Montagu, 1821)) in mesotidal salt marshes of South Carolina and Georgia, USA, employ a unique foraging tactic called strand-feeding, in which a coordinated group [...]