Daiki Ousaka

Dr. Daiki Ousaka

Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 December 2020 in Cells
Verified
Journal Article
Open access
PDF file
MNMasahiro Nishibori
Masahiro Nishibori
DWDengli Wang
Dengli Wang
DODaiki Ousaka
Daiki Ousaka
HWHidenori Wake
Hidenori Wake
Increasing evidence suggests that inflammatory responses are involved in the progression of brain injuries induced by a diverse range of insults, including ischemia, hemorrhage, trauma, epilepsy, and degenerative diseases. During the processes of inflammation, disruption of the blood–brain barrier (BBB) may play a critical role in the enhancement of inflammatory responses and may initiate brain damage because the BBB constitutes an interface between the brain parenchyma and the bloodstream containing blood cells and plasma. The BBB has a distinct structure compared with those in peripheral tissues: it is composed of vascular endothelial cells with tight junctions, numerous pericytes surrounding endothelial cells, astrocytic endfeet, and a basement membrane structure. Under physiological conditions, the BBB should function as an important element in the neurovascular unit (NVU). High mobility group box-1 (HMGB1), a nonhistone nuclear protein, is ubiquitously expressed in almost all kinds of cells. HMGB1 plays important roles in the maintenance of chromatin structure, the regulation of transcription activity, and DNA repair in nuclei. On the other hand, HMGB1 is considered to be a representative damage-associated molecular pattern (DAMP) because it is translocated and released extracellularly from different types of brain cells, including neurons and glia, contributing to the pathophysiology of many diseases in the central nervous system (CNS). The regulation of HMGB1 release or the neutralization of extracellular HMGB1 produces beneficial effects on brain injuries induced by ischemia, hemorrhage, trauma, epilepsy, and Alzheimer’s amyloidpathy in animal models and is associated with improvement of the neurological symptoms. In the present review, we focus on the dynamics of HMGB1 translocation in different disease conditions in the CNS and discuss the functional roles of extracellular HMGB1 in BBB disruption and brain inflammation. There might be common as well as distinct inflammatory processes for each CNS disease. This review will provide novel insights toward an improved understanding of a common pathophysiological process of CNS diseases, namely, BBB disruption mediated by HMGB1. It is proposed that HMGB1 might be an excellent target for the treatment of CNS diseases with BBB disruption.

11 December 2022 in Cureus
Verified
Journal Article
Open access
KHKenta Hirai
Kenta Hirai
DODaiki Ousaka
Daiki Ousaka
YKYosuke Kuroko
Yosuke Kuroko
SKShingo Kasahara
Shingo Kasahara
Sudden cardiac events in young athletes are a major concern in the field of sports cardiology. Although coronary artery anomalies remain a major cause of cardiac events in young athletes, only a few cases have been diagnosed prior to critical events. Here, we present the case of a previously asymptomatic young male runner who experienced sudden cardiac arrest at the end of a marathon. The patient immediately received cardiopulmonary resuscitation from a bystander and was transported to an emergency hospital. As his electrocardiogram showed ventricular fibrillation, he was treated with electric shock, and his rhythm was successfully converted to a normal sinus rhythm. Following successful resuscitation, the patient was diagnosed with an anomalous origin of the right coronary artery from the left sinus of Valsalva with an intramural course. The patient underwent coronary artery bypass using the right internal thoracic artery. Fifteen years later, the coronary bypass was found to be blocked, but the patient was asymptomatic. However, an exercise electrocardiogram revealed ST-segment elevation in the inferior leads. The patient then underwent an unroofing procedure. He has remained asymptomatic without complications for two years after the second surgery.