Photothermal effects on murine mammary tumors using indocyanine green and an 808-nm diode laser: an in vivo efficacy study.

Murine mammary tumors were treated using indocyanine green and an 808 nm diode laser, and the in vivo chromophore-enhanced photothermal effects on the tumor burden and on tumor rat survival were investigated. The power of the laser was selected in the range of 5-10 W, and irradiation duration 3-5 min. One percent aqueous indocyanine green solution in a volume of 100-200 microliters was administered in situ, either acutely or 24 h prior to the treatment. The photothermal interaction was apparent under all our treatment conditions with a well-defined spatial containment in this study and the tumor growth was slowed after treatment. The post-treatment observation showed tumor recurrence and metastasis; no long-term survival was achieved with the single application of laser in conjunction with indocyanine green. Our results pose a question on the efficacy of the photothermal interaction even though tumor cell destruction can be achieved in a large and controlled scale. However, this highly selective photothermal impact on the tumor tissue did suggest that this method be applied repeatedly to be more effective and be used as the precursor of other modalities, such as chemotherapy, radiation therapy, immunotherapy, and surgery.

Peralkaline volcanicity on the Eurasia Basin margin.

The Kap Washington Group of post-Palaeozoic explosive volcanic rocks was discovered in 1969 on the north coast of Greenland. Although there have been uncertainties regarding their age and chemical character, they have featured prominently in geotectonic reconstructions of the Arctic regions-in recent interpretations as products of the Yermak hot spot, generated on the Nansen spreading axis during the opening of the Eurasia Basin. We present here new evidence which confirms the volcanicity as end-Cretaceous in age and of peralkaline type. We show that a direct connection with the Yermak hot spot is improbable and infer that the volcanic rocks were generated in a continental extensional rift environment before the break-up of the Laurasian plate in the Arctic. Their age helps to constrain the timing of this poorly understood event.