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Dive into the research topics where Risa Kudo is active.

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Featured researches published by Risa Kudo.


Free Radical Biology and Medicine | 2001

Lipid peroxidation in the rat brain after CO inhalation is temperature dependent.

Risa Kudo; Junko Adachi; Koichi Uemura; Tsuyoshi Maekawa; Yasuhiro Ueno; Kenichi Yoshida

We reported previously that 7-hydroperoxycholesterols, 7 alpha- and 7 beta-hydroperoxycholest-5-en-3 beta-ol (7 alpha-OOH and 7 beta-OOH), indicated lipid peroxidation. In the present study, we measured not only 7-hydroperoxycholesterols but also oxysterols (7 alpha- and 7 beta-hydroxycholesterol, 7 alpha-OH, and 7 beta-OH) and 3 beta-hydroxycholest-5-en-7-one (7-keto) in the brains of rats that underwent either a sham operation (control), hypoxia, or CO inhalation (1005 ppm) at 37 degrees C for 90 min followed by 48 h of recovery. The levels of 7-hydroperoxycholesterols, 7 beta-OH, and 7-keto were low in the hypoxia group, while the levels were unaltered in the CO group compared with the controls. Among the three groups of CO inhalation, these levels were high in the hyperthermia group (39 degrees C), and the 7-hydroperoxycholesterols were low in the hypothermia group (32 degrees C), compared with the control group. The blood O(2) saturation was almost normal in the hypothermia group, while it was similarly low in the hyperthermia and normothermia groups. The temperature-dependent lipid peroxidation in the brain after CO inhalation and recovery can not be explained by hypoxia due to CO-hemoglobin formation, but may contribute to the delayed neuronal death following CO inhalation. Hypothermia may be applicable to treat patients after CO inhalation.


Legal Medicine | 2013

Respiratory complications of Ehlers-Danlos syndrome type IV.

Katsuhiko Hatake; Yoshifumi Morimura; Risa Kudo; Wataru Kawashima; Shogo Kasuda; Hiroki Kuniyasu

We describe a case of Ehlers-Danlos syndrome (EDS) type IV in a male in early half in his twenties, who experienced recurrent and eventually fatal pulmonary hemorrhage. EDS type IV is a rare disorder of type III collagen synthesis that is characterized by unusual facies, thin translucent skin with a venous vascular pattern, easy bruising, and hypermobility of the small joints. Autopsy findings showed hypermobility of the joints and distensibility of the skin. Microscopically, the abdominal skin showed substantially decreased dermal thickness. Moreover, the reticular dermis showed fine collagen bundles and large interstitial spaces compared with the skin from a normal control that showed large collagen bundles. Individual elastic fibers were also thicker than those observed in the skin of a normal control. The thoracic aorta showed thin adventitia and a relative increase in elastic fibers. The parenchyma of both the lungs showed markedly diffuse hemorrhage with hemosiderin-laden alveolar macrophages or old thrombi and organized thrombi in the small bronchi. Furthermore, both sections of the lung showed multiple fibrous nodules containing benign metaplastic bone. Vascular wall disruption and tearing of the vessel walls in the lung parenchyma were also observed. We concluded that EDS type IV led to the patients death because of pulmonary hemorrhage. Because this syndrome resulted in the patients death from arterial and bowel rupture, it is important to consider EDS as a potential cause of sudden death.


Journal of Forensic Research | 2014

Estimating the Time after Death on the Basis of Corneal Opacity

Wataru Kawashima; Katsuhiko Hatake; Risa Kudo; Mari Nakanishi; Shigehiro Tamaki; Shogo Kasuda; Katsuya Yuui; Akiko Ishitani

Estimation of the time after death (TAD) is an important aspect of forensic science. The cornea becomes increasingly opaque with an increase in TAD and corneal opacity is used for TAD estimation. However, previous methods are subjective, and there is a risk of human error. To establish an objective method, we propose a new method for TAD estimation. We applied RGB image analysis to the corneal color of cadavers. We then examined if there was a correlation between these color parameters and actual TAD, age, position at death, and environmental temperature. We found that corneal opacity was affected only by TAD. The method described here is objective and easy to use, and TAD can be estimated within a very short period of time, making this method particularly useful. To further increase the accuracy of TAD estimation, other quantifiable parameters could also be evaluated.


Forensic Science International | 2013

Asphyxial death related to postextraction hematoma in an elderly man

Wataru Kawashima; Katsuhiko Hatake; Yoshifumi Morimura; Risa Kudo; Mari Nakanishi; Shigehiro Tamaki; Shogo Kasuda; Katsuya Yuui; Akiko Ishitani

We here report an autopsy case of a man in his seventies who died from asphyxia due to compression of the trachea caused by postextraction bleeding after extraction of his left mandibular third molar by a dentist in private practice. On the morning after the tooth extraction, he had complained of dyspnea and became unconscious at home. Although he was brought to the emergency room by ambulance, he died 7 days later without regaining consciousness. Autopsy examination revealed that the lingual side of the alveolar bone was fractured at the extraction socket. Moreover, subcutaneous bleeding that extended from the extraction socket to the thyrohyoid ligament in the cervical region and deviation of the epiglottis due to the bleeding were observed. Histological findings revealed liver cirrhosis; there were no significant findings in other organs. On the basis of these findings, we concluded that alveolar bone fracture occurred during the extraction and that the bleeding spread to the cervical region. Thus, the patient had died from asphyxia resulting from airway obstruction caused by cervical subcutaneous bleeding derived from postextraction bleeding. We emphasize that tooth extraction may cause fatal complications in patients with bleeding tendencies, particularly in the elderly.


Legal Medicine | 2016

An autopsy case of complete adipocere formation

Shogo Kasuda; Risa Kudo; Katsuya Yuui; Hiroko Imai; Masatoshi Nakata; Katsuhiko Hatake

A car containing a male corpse with complete adipocere formation was found at the bottom of a lake. The deceased had presumably driven into the lake 7 years earlier. The surface of the deceased was unusually hard and firm like a gypsum board, and the entire internal viscera had turned into adipocere. Since the time required for adipocerous changes depends largely on environmental conditions, we considered the key conditions, namely, water temperature, pH, and oxygen content. In our case, cold, acidic water may have delayed adipocere formation, thus necessitating a long period of time for completeness. On the other hand, anoxic conditions and the peculiar environment of a lake bottom presumably contributed to complete adipocere formation.


Addiction Biology | 2003

Fatty acid profile in skeletal muscle of the rat in response to acute (2.5 hours) and prolonged (6 weeks) ethanol-dosage.

Junko Adachi; Risa Kudo; Hideyuki Nushida; Yasuhiro Ueno; Michael Koll; Victor R. Preedy

We tested the hypothesis that phospholipids are altered in skeletal muscles of rats exposed to ethanol for either acute (2.5 hours) or prolonged (6 weeks) periods. In acute studies, rats were dosed with saline (0.15 mmol/l; controls) or ethanol (75 mmol/kg body weight; treated). There were four groups: (A) saline (control); (B) cyanamide (an aldehyde dehydrogenase inhibitor); (C) ethanol; and (D) cyanamide+ethanol. In prolonged studies, two groups of rats were fed liquid diets containing 35% of total dietary energy as either glucose [group (E)] or ethanol [group (F)]. At the end of the treatments, membrane phospholipids were measured in soleus (Type I fibre‐predominant) and plantaris (Type II fibre‐predominant) muscle. In acute studies, ethanol alone [(A) vs. (C)] and cyanamide+ethanol [(A) vs. (D)] significantly increased 18:2 in plantaris (p <0.05), whereas in soleus none of the treatments had any effect on the phospholipids. In prolonged studies [(E) vs. (F)], there were decreases in 16:0 (p <0.05) and 18:1 (p <0.01) and increases in 18:2 (p<0.001) in plantaris. In soleus, decreases in 18:1 (p<0.05) and increases in 18:2 (p <0.01) occurred. In conclusion, alterations in the proportions of 16:0, 18:1 and 18:2 provide evidence of an altered membrane domain which may contribute to the pathogenesis of alcohol‐induced muscle disease. Changes due to prolonged exposure are more profound than those in acute exposure and the preferential effects in Type II plantaris may reflect the greater susceptibility of this muscle to alcohol.


Journal of Forensic Research | 2015

Two Autopsy Cases of Water Intoxication

Wataru Kawashima; Katsuhiko Hatake; Risa Kudo; Mari Nakanishi; Shigehiro Tamaki; Shogo Kasuda; Katsuya Yuui; Akiko Ishitani

We here report two autopsy cases of men with an intellectual disability who died from water intoxication. (Case 1) A 22-year-old man was found dead in a prone position in his room. Autopsy and histological findings revealed the edema of brain and lung. The serum Na value was 108 mEq/L. (Case 2) A 23-year-old man suddenly fell and was found unconscious. Autopsy and histological findings revealed the edema of brain and lung. In lung tissue, deposition of fibrin around the vessels, was found. The serum Na value was <100 mEq/L. On the basis of these findings, we concluded that they were died from water intoxication and hyponatremia as a result of massive drinking. We also discuss new autopsy findings that support the diagnosis of water intoxication and we investigate the serum Na value of autopsy cases (N=17) in order to analyses the postmortem change of serum Na value.


Journal of Thrombosis and Thrombolysis | 2018

Experimental hypercoagulable state induced by tissue factor expression in monocyte-derived dendritic cells and its modulation by C1 inhibitor

Shogo Kasuda; Yoshihiko Sakurai; Kohei Tatsumi; Tomohiro Takeda; Risa Kudo; Katsuya Yuui; Katsuhiko Hatake

The crosstalk between immune and coagulation systems plays pivotal roles in host defense, which may involve monocyte-derived dendritic cells (moDCs). Our objectives were to elucidate the role of moDCs in coagulation under inflammatory conditions and the involvement of the complement system. We assessed the effects of lipopolysaccharide (LPS)-stimulated moDCs on coagulation using whole blood thromboelastometry in the presence of complement inhibitors. The sum of clotting time and clot formation time (CT plus CFT) in whole blood thromboelastometry was significantly more reduced in the presence of moDCs than in the absence of monocytes or moDCs and in the presence of monocytes, indicating a more potent coagulability of moDCs. The mRNA expression of coagulation-related proteins in moDCs was analyzed by quantitative PCR, which showed an increase only in the mRNA levels of tissue factor (TF). TF protein expression was assessed by western blot analysis and an activity assay, revealing higher TF expression in moDCs than that in monocytes. The in vitro moDC-associated hypercoagulable state was suppressed by a TF-neutralizing antibody, whereas LPS enhanced the in vitro hypercoagulation further. C1 inhibitor suppressed the in vitro LPS-enhanced whole blood hypercoagulability in the presence of moDCs and the increased TF expression in moDCs. These results suggest a significant role of moDCs and the complement system through TF expression in a hypercoagulable state under inflammatory conditions and demonstrate the suppressive effects of C1 inhibitor on moDC-associated hypercoagulation.


Bulletin of Experimental Biology and Medicine | 2018

Induced Pluripotent Stem Cell-Derived Hematopoietic Embryoid Bodies Secrete Sphingosine-1-Phosphate and Revert Endothelial Injury

Shogo Kasuda; Risa Kudo; Katsuya Yuui; Y. Sakurai; Katsuhiko Hatake

The possibility of sphingosine-1-phosphate production by induced pluripotent stem cells is examined to assess their potential in treatment of sepsis. The hematopoietic embryoid bodies were derived from the culture of 6-day-old differentiated induced pluripotent stem cells. These embryoid bodies secreted sphingosine-1-phosphate, an important bioactive lipid that regulates integrity of the pulmonary endothelial barrier, prevents elevation of its permeability, and impedes the formation of stress fibers in human endotheliocytes derived from umbilical vein. The data attest to potentiality of induced pluripotent stem cells in treatment of sepsis.


Legal Medicine | 2017

Relevance of hemolysis-induced tissue factor expression on monocytes in soft clot formation in alcohol-containing blood

Masatoshi Nakata; Shogo Kasuda; Katsuya Yuui; Risa Kudo; Katsuhiko Hatake

The fluidity of cadaveric blood is an important characteristic in the post-mortem examination of cases of asphyxial death. Although it is empirically known that soft blood clots are present in cadaveric blood containing alcohol, the relationship between such clots and blood alcohol is unclear. We addressed this issue through in vitro studies using blood collected from healthy volunteers. Assessment of global hemostasis by rotational thromboelastometry revealed that ethanol treatment enhanced the procoagulant activity of whole blood. However, ethanol inhibited epinephrine-induced platelet aggregation, whereas plasma levels of von Willebrand factor and the activity of coagulation factors VIII and IX were unaffected. In contrast, tissue factor (TF) activity was higher in plasma obtained from ethanol-treated whole blood than that in plasma from untreated blood. Ethanol induced hemolysis of red blood cells, and the consequent hemoglobin (Hb) release promoted de novo synthesis of TF in isolated monocytes, as determined by real-time reverse transcription PCR, western blotting, and flow cytometry. However, ethanol itself did not induce TF expression in monocytes. Given that TF activates the extrinsic coagulation pathway and amplifies hemostatic reactions, Hb-induced TF expression in monocytes might contribute to soft blood clot formation.

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Shogo Kasuda

Nara Medical University

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Katsuya Yuui

Nara Medical University

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