Mitsuyo Maeda

Differentiation between dysmyelination and demyelination using magnetic resonance diffusional anisotropy

Using magnetic resonance (MR) diffusion-weighted method, we examined the optic and the trigeminal nerves of jimpy and twitcher mice, considered to be animal models of Pelizaeus-Merzbacher disease, hypomyelination disorder, and Krabbe disease, demyelination disorder, respectively. In jimpy mice, diffusional anisotropy of optic nerve did not show a significant difference compared to age-matched control mice, suggesting that diffusional anisotropy does exist in absence of multiple layers of myelin sheath. In twitcher mice, diffusional anisotropy was attenuated remarkably in the optic and trigeminal nerves. Loss of axonal straightness on longitudinal section confirmed by electron microscopy appeared to be the principal explanation for it. It is further suggested that this MR diffusion-weighted imaging method enables us to differentiate hypomyelination from demyelination in vivo.

Immunocytochemical localization of manganese superoxide dismutase (Mn-SOD) in the hippocampus of the rat

The immunocytochemical distribution of manganese superoxide dismutase (Mn-SOD) was determined in the rat hippocampus. The enzyme was localized in the mitochondria. CA1 pyramidal cells were weakly immunostained, whereas CA3 pyramidal cells were strongly reactive. These differences in the intensity of the Mn-SOD immunostaining reactions may relate to variations in the sensitivity of subfields of the hippocampus to ischemia.

The synaptic relationship between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and their axon terminals in the rat small intestine: light and electron microscopic study

The present study demonstrates synaptic contacts between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and immunoreactive axon terminals in the submucous and myenteric plexuses of the rat small intestine. Our observations suggest that VIP afferents directly affect the VIP neurons in the small intestine via synapses.

A case in which cytodiagnosis was useful for evaluation of aspergillus.

脾カンジダ症を伴った気管支肺アスペルギルス症の1剖検例を報告し, それを用いて, 内臓真菌症の中でも原因菌属としてカンジダに次いで最も多いアスペルギルスの同定を, 菌糸のみの形態的特徴から試みた.症例は43歳, 女性. 急性前骨髄球性白血病の再燃例で右肺中・下葉および左上葉にアスペルギルスによる肺炎をきたし, 右中・下葉の一部は横隔膜に癒着し, 右出血性胸膜炎を呈していた.左上葉では空洞を形成していた. 脾には結節状のカンジダ感染が認められた. 剖検時に右肺・横隔膜癒着部および左上葉空洞内の壊死物の塗抹標本を作製したところ, アスペルギルスの菌糸の特徴すなわち, Y字状に2分岐しながら一方向へ向かって増殖するようすがきわめて明瞭に見い出され, 組織標本で観察できた菌糸形態よりも真菌の同定に役立つと考えられた.