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Featured researches published by Toshiaki Nagai.


Medicine Science and The Law | 2004

2. An Autopsy Case of Fatal Anaphylactic Shock Following Fluorescein Angiography

Masahito Hitosugi; Kazunobu Omura; Tomoko Yokoyama; Hitoshi Kawato; Yasuki Motozawa; Toshiaki Nagai; Shogo Tokudome

We present a rare autopsy case of fatal anaphylactic shock following fluorescein angiography. A 71-year-old Japanese woman undergoing retinal angiography to evaluate diabetic retinopathy died immediately after an injection of sodium fluorescein. Forensic autopsy and post-mortem biochemical analyses revealed an elevated serum level of tryptase which, in the absence of morphologic changes suggesting injury or disease, confirmed the diagnosis of fatal anaphylactic shock. Although serious adverse effects are rare after fluorescein angiography, patients should be observed, with appropriate resuscitation equipment available, for several hours after the administration of fluorescein.


Medicine Science and The Law | 2004

Changes in Blood Viscosity with Heavy and Light Exercise

Masahito Hitosugi; Hitoshi Kawato; Toshiaki Nagai; Yoshinori Ogawa; Munehiro Niwa; Naoko Iida; Tetsuo Yufu; Shogo Tokudome

To clarify the relationship of the intensity of acute exercise to sudden cardiac death, we examined the effects of short-term heavy and light exercise on whole blood viscosity. Nine healthy sedentary male volunteers performed ten minutes of heavy (more than 95% of maximum oxygen consumption) or light (60% to 65% of maximum oxygen consumption) exercise. Blood samples were obtained before, immediately after, and one hour after exercise. The whole blood viscosity was immediately examined with an oscillation-type viscometer and was found to increase significantly after exercise and subsequently return to baseline levels within one hour after exercise. The whole blood viscosity increased by a similar degree after heavy or light exercise. Therefore, our results suggest that there is a similar risk of sudden cardiac death, due to increased whole blood viscosity, after short-term heavy or light exercise.


Neuroscience Letters | 2003

Facilitatory action of halothane at subanesthetic concentrations on glutamatergic excitatory synaptic transmission in the CA1 area of adult rat hippocampus.

Toshiki Otsubo; Yoshitaka Nakamura; Toshiaki Nagai; Yuuichi Hori

Whole-cell recordings were made from pyramidal cells visually identified in the CA1 field of adult rat hippocampal slices, and the effects of subanesthetic concentrations of halothane on excitatory postsynaptic currents mediated by non-N-methyl-D-aspartate subtype glutamate receptors were investigated. Halothane concentrations were measured by gas chromatography. At concentrations of 0.2 mM and 0.6 mM, halothane reversibly decreased the amplitude of excitatory postsynaptic currents (EPSCs) evoked by electrical stimulation of Schaffer collateral fibers, and the decrease was accompanied by enhanced paired-pulse facilitation, consistent with the previously reported presynaptic site of halothanes inhibitory action. By contrast, at lower concentrations (0.02 mM and 0.05 mM), halothane increased the amplitude of EPSCs without any appreciable changes in paired-pulse facilitation. Moreover, the frequency of miniature EPSCs arising spontaneously in the presence of tetrodotoxin (mEPSCs) was increased by subanesthetic halothane, but the amplitude of the mEPSCs did not change significantly. These observations suggest that at subanesthetic concentrations halothane postsynaptically enhances glutamatergic excitatory synaptic transmission. This may provide a vital clue to elucidation of the neural mechanisms of the nociceptive reflex enhancement and excitatory state that occur at light levels of anesthesia.


The Lancet | 2003

Risk of death due to alcohol-impaired driving in Japan

Masahito Hitosugi; Yoshihide Sorimachi; Akira Kurosu; Toshiaki Nagai; Shogo Tokudome

It is noted that after WWII, the number of motor vehicles increased rapidly in Japan. This increase was accompanied by a rise in the number of road traffic accidents (RTAs) and of alcohol-related traffic violations. In 1970, the Government of Japan introduced a law setting the maximum breath alcohol concentration at 0725 mg/L. The law was revised in 1978 to increase penalties for drivers violating this law. The authors briefly discuss findings of their determinations of the relative risks of fatal RTAs due to alcohol-impaired driving in Japan.


Journal of Analytical Toxicology | 2000

Interpretation and Enantiomer Analysis of Methamphetamine Abusers' Urine and Illegally Brewed Methamphetamine Crystals

Toshiaki Nagai; Kazumi Matsushima; Tatsuo Nagai; Yuko Yanagisawa; Akihiko Fujita; Akira Kurosu; Shogo Tokudome


Journal of Analytical Toxicology | 1991

Simultaneous HPLC Analysis of Optical Isomers of Methamphetamine and Its Metabolites, and Stereoselective Metabolism of Racemic Methamphetamine in Rat Urine

Toshiaki Nagai; Shigetaro Kamiyama


Journal of Chromatography B: Biomedical Sciences and Applications | 1990

Assay of the optical isomers of methamphetamine and amphetamine in rat urine using high-performance liquid chromatography with chiral cellulose-based columns

Toshiaki Nagai; Shigetaro Kamiyama


Journal of Analytical Toxicology | 1998

Optical isomer analysis of 3,4-methylene-dioxyamphetamine analogues and their stereoselective disposition in rats

Kazumi Matsushima; Toshiaki Nagai; Shigetaro Kamiyama


Journal of Analytical Toxicology | 1997

Time-lapse changes of d- and l-enantiomers of racemic (dl)-ethylamphetamine in human urine

Toshiaki Nagai; Hideaki Kanaya; Kazumi Matsushima; Shigetaro Kamiyama


Journal of Analytical Toxicology | 1995

Analysis of Time-Lapse Changes of d- and l-Enantiomers of Racemic Ethylamphetamine and Stereoselective Metabolism in Rat Urine by HPLC Determination

Toshiaki Nagai; Shigetaro Kamiyama; Kazumi Matsushima

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Shogo Tokudome

Dokkyo Medical University

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Akira Kurosu

Dokkyo Medical University

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Munehiro Niwa

Chiba University of Commerce

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