Feasibility of Organ Transportation by a Drone: An Experimental Study Using a Rat Model.

BACKGROUND: Recently, the successful delivery of organs for transplantation using drones was reported. We investigated the influence of transportation by drones on the quality of liver grafts using a rat model. METHODS: Livers of 12 rats (8 and 32 weeks old) were divided into 2 groups of six. Livers were split into 2 parts and allocated to the drone or control groups (both n = 12). The drone experiment was conducted between islands in Nagasaki Prefecture, Japan. The distance between the islands was 12 km. Livers of the drone group were transported by a multicopter at a speed of 30 km-40 km/h over 60 m above sea level. Transported liver quality was analyzed by histology, and biochemistry data were compared between groups. RESULTS: Cold ischemia time did not differ between groups (902 min and 909 min, respectively). There were no differences in macroscopic findings regarding coloration and damage between groups. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in preservation fluid were graft weight-corrected and compared, and no significant differences were found between groups: AST/g (4.61 vs 4.81 IU/L), ALT/g (2.78 vs 2.92 IU/L), and ALP/g (39.1 vs 37.0 IU/L). Immunochemical staining showed no significant difference between groups for terminal deoxynucleotidyl transferase dUTP nick and labeling staining (141 vs 113 cells), CD163 (818 vs 870 cells), and TNF-α (1.25 vs 1.41 scores). CONCLUSIONS: The simulation experiment of organ transport for transplantation by drones was successfully conducted. There were no differences in the quality of livers transported by drones or other means. Further studies including large-animal experiments could lead to future clinical applications.

The volition, the mode of movement selection and the readiness potential.

A growing body of evidence suggests that the mode of movement selection is relevant for the readiness potential, namely, internal (or free) selection of movements is associated with increased readiness potential amplitudes compared to predetermined or externally guided selection. It is little acknowledged, however, that this finding may be ascribed to the different expression of volition (i.e., conscious experience of choice) rather than to the mode of movement selection per se. To probe this issue, we conducted two experiments: in Experiment 1, a mental task was employed to distract sixteen volunteers from the selection and performance of incidental movements, which consisted of pressing one of two buttons according to either free or externally guided modes of movement selection; in Experiment 2, another sixteen individuals performed the same motor task, however, they were encouraged to attend to their intention to act. As result, the increased readiness potential amplitude before freely selected movements was found exclusively in Experiment 2. More detailed analysis suggested that the attention to the initiation of movements was associated with greater readiness potential in its medial and late portion, while the attention to the movement selection, with more global increase of the component. The study suggests that much of the higher demands on motor preparatory activities ascribed to the internal selection of movements in previous studies actually depends on individual's attention and, thus, probably corresponds to volitional processes.

Disruption of volitional control in obsessive-compulsive disorder: Evidence from the Bereitschaftspotential.

In the context of controversies involving possible abnormalities in the volition and action control in obsessive-compulsive disorder (OCD), the current study examined electroencephalographic correlates of automatic and volitional brain processes involved in the genesis of spontaneous movements in individuals diagnosed with OCD. For this, the amplitudes of early and late Bereitschaftspotential (early BP and late BP) from 12 patients and 12 controls were obtained while they performed spontaneous button presses under different levels of volitional experience. In the first condition, participants were distracted from their motor actions by a mental task (automatic condition) and in the second condition they were instructed to attending to their own intention to move (willed condition). The results corroborate previous report that the attention to (and, presumably, the awareness of) intention to act accounts for the expression of significant portion of the late BP in healthy individuals. More relevantly, the increased late BP in willed condition in relation to automatic condition was not present in the OCD group. Neither groups nor conditions affected the early BP. In sum, the current findings suggest the existence of abnormalities in the brain activities associated with the establishment of volitional control in OCD patients.

The effect of conscious intention to act on the Bereitschaftspotential.

The current study investigated the effect of conscious intention to act on the Bereitschaftspotential. Situations in which the awareness of acting is minimally expressed were generated by asking 16 participants to press a button after performing a mental imagery task based on animal pictures (automatic condition). The affective responses induced by the pictures were controlled by selecting the animals according to different valences, threatening and neutral. The Bereitschaftspotential associated with the button presses was compared to the observed when similar movements were performed under the basic instructions of the self-paced movement paradigm (willed condition). Enhanced Bereitschaftspotential amplitudes were observed in the willed condition with respect to the automatic condition. This effect was manifested as a negative slope at medial frontocentral sites during the last 500 ms before movement onset. The valence of the pictures did not affect the motor preparatory potentials. The results suggest that significant part of the NS' subcomponent of the readiness potential is associated with the attention to-and, presumably, awareness of-intention to move, possibly reflecting cortical activation from supplementary motor areas. Secondarily, our findings supports that the feeling of threat does not influence the Bereitschaftspotential associated with automatic movements. Regarding methodological issues, the behavioural model of spontaneous voluntary movements proposed in automatic condition can benefit investigations on purely motor (or non-cognitive) subcomponents of the Bereitschaftspotential.

The dipole moments of membrane proteins: potassium channel proteins. II. T1 assembly. Search for the voltage sensor.

The dipole moments of potassium channel protein (Kcsa) and beta-subunits were discussed in the previous paper of this series [Takashima, Biophys. Chem. 94 (2001) 209-218]. While the dipole moment of beta-subunits was found to be very large, the dipole moment of Kcsa turned out to be somewhat smaller than beta-subunits. As the continuation of this work, the discussion of the present paper is focussed on the dipole moment of T1 assembly, another component of the K-channel. As discussed later, the calculation using the X-ray crystallographic data by MacKinnon et al., revealed an astoundingly large dipole moment for T1 assembly. The dipole moment of T1 assembly combined with the likewise large dipole moment of beta-subunits amounts to a sufficient value to play an essential role as a voltage sensor of potassium channel.