Autologous Transfusion of Blood Aspirated during Suction Decompression in Clipping of Large or Giant Cerebral Aneurysm.

The suction decompression (SD) method, which proactively aspirates the blood flowing into the aneurysm and reduces the internal pressure of the aneurysm, is useful for clipping surgery of large and giant cerebral aneurysm. However, there has been little discussion on re-utilization of blood aspirated during SD. This study aimed to examine the safety, convenience, and usefulness of autologous transfusion of aspirated blood using a transfusion bag. At the time of craniotomy, the cervical carotid artery is fully exposed. An angiocatheter sheath was inserted into the carotid artery and placed in the internal carotid artery. In SD, blood was aspirated from the sheath at a constant speed and quickly stored in a blood transfusion storage bag. Blood aspiration was repeated with a new syringe; once the transfusion bag was full, the blood was re-administered to the patient. Changes in vital sign and hemoglobin/hematocrit values before and after SD were examined in five cases performed in this procedure. The aspirated blood volumes of five cases ranged from 130 to 400 mL, and all aspirated blood was successfully re-transfused. There was no critical change in vital sign, and no significant decrease in the hemoglobin/hematocrit value. No findings suggestive of complications of thrombus formation, infection, and hemolysis were noted. Re-transfusion of aspirated blood during SD using a transfusion bag is a simple and safe method, which can minimize potential risk of re-utilizing aspirated blood, and enables the safe and easy execution of SD regardless of aspirated blood volume.

Spatial prisoner's dilemma games with zealous cooperators.

The existence of a zealot who stays a cooperator irrespective of the result of an interaction has been reported to add "social viscosity" to a population and thereby helps increase the cooperation level in prisoner's dilemma games, which premises the so-called well-mixed situation of a population. We found that this is not always true when a spatial structure, i.e., connecting agent, is introduced. Deploying zealots is counterproductive, especially when the underlying topology is homogenous, similar to that of a lattice. Our simulation reveals how the existence of never-converting cooperators destroys rather than boosts cooperation. We explain detailed mechanisms behind this interesting finding by referring to our previously presented concepts with respect to evolutionary dynamic processes for spatial games under the names enduring and expanding periods.

Changes in backscatter of liver tissue due to thermal coagulation induced by focused ultrasound.

Ultrasonic imaging has advantages in its self-consistency in guiding and monitoring ultrasonic treatment such as high-intensity focused ultrasound (HIFU) treatment. Changes in ultrasonic backscatter of tissues due to HIFU treatment have been observed, but their mechanism is still under discussion. In this paper, ultrasonic backscatter of excised and degassed porcine liver tissue was observed before and after HIFU exposure using a diagnostic scanner, and its acoustic impedance was mapped using an ultrasonic microscope. The histology of its pathological specimen was also observed using an optical microscope. The observed decrease in backscatter intensity due to HIFU exposure was consistent with a spatial Fourier analysis of the histology, which also showed changes due to the exposure. The observed increase in acoustic impedance due to the exposure was also consistent with the histological change assuming that the increase was primarily caused by the increase in the concentration of hepatic cells.