Niigata University

About: Niigata University is a education organization based out in Niigata, Japan. It is known for research contribution in the topics: Population & Transplantation. The organization has 18847 authors who have published 35135 publications receiving 819766 citations. The organization is also known as: Niigata daigaku.

Mitochondrial division occurs concurrently with autophagosome formation but independently of Drp1 during mitophagy

Abstract: Mitophagy is thought to play an important role in mitochondrial quality control. Mitochondrial division is believed to occur first, and autophagosome formation subsequently occurs to enwrap mitochondria as a process of mitophagy. However, there has not been any temporal analysis of mitochondrial division and autophagosome formation in mitophagy. Therefore, the relationships among these processes remain unclear. We show that the mitochondrial division factor Dnm1 in yeast or Drp1 in mammalian cells is dispensable for mitophagy. Autophagosome formation factors, such as FIP200, ATG14, and WIPIs, were essential for the mitochondrial division for mitophagy. Live-cell imaging showed that isolation membranes formed on the mitochondria. A small portion of the mitochondria then divided from parental mitochondria simultaneously with the extension of isolation membranes and autophagosome formation. These findings suggest the presence of a mitophagy process in which mitochondrial division for mitophagy is accomplished together with autophagosome formation.

Preemptive analgesia by intravenous low-dose ketamine and epidural morphine in gastrectomy: a randomized double-blind study.

Abstract: Background Morphine and ketamine may prevent central sensitization during surgery and result in preemptive analgesia. The reliability of preemptive analgesia, however, is controversial. Methods Gastrectomy patients were given preemptive analgesia consisting of epidural morphine, intravenous low-dose ketamine, and combinations of these in a randomized, double-blind manner. Postsurgical pain intensity was rated by a visual analog scale, a categoric pain evaluation, and cumulative morphine consumption. Results Preemptive analgesia by epidural morphine and by intravenous low-dose ketamine were significantly effective but not definitive. With epidural morphine, a significant reduction in visual analog scale scores at rest was observed at 24 and 48 h, and morphine consumption was significantly lower at 6 and 12 h, compared with control values. With intravenous ketamine, visual analog scale scores at rest and morphine consumption were significantly lower at 6, 12, 24, and 48 h than those in control subjects. The combination of epidural morphine and intravenous ketamine provided definitive preemptive analgesia: Visual analog scale scores at rest and morphine consumption were significantly the lowest at 6, 12, 24, and 48 h, and the visual analog scale score during movement and the categoric pain score also were significantly the lowest among the groups. Conclusion The results suggest that for definitive preemptive analgesia, blockade of opioid and N-methyl-d-aspartate receptors is necessary for upper abdominal surgery such as gastrectomy; singly, either treatment provided significant, but not definitive, postsurgical pain relief. Epidural morphine may affect the spinal cord segmentally, whereas intravenous ketamine may block brain stem sensitization via the vagus nerve during upper abdominal surgery.

Four-Component Scattering Power Decomposition With Extended Volume Scattering Model

Abstract: In the three- or four-component decompositions, polarimetric scattering properties and corresponding physical scattering models play essential roles for power decomposition. This letter proposes an improved four-component scattering power decomposition method that employs a suitable volume scattering model for single- or double-bounce scattering in the polarimetric synthetic aperture radar image analysis. The cross-polarized HV component is created by both single-bounce object (such as vegetation) and double-bounce structures (such as oriented building blocks). It has been difficult to discriminate these two objects (vegetation against oriented buildings) in the decomposed images since the HV component is assigned to the volume scattering due to vegetation only. We propose to extend the volume scattering model suited for two physical scattering models. It is shown that a vegetation area and an oriented urban building area are well discriminated compared to those resulting from the implementation of the existing four-component scattering power decomposition.