Biomedical subjects

Akira Tanaka

Publications and source records attributed to Akira Tanaka.

114 records · Page 7Linked to original sources

PubMedDate not supplied

Inhibition of very-long-chain fatty acid formation by indanofan, 2-[2-(3-chlorophenyl)oxiran-2-ylmethyl]-2-ethylindan-1,3-dione, and its relatives.

Indanofan and its analogs inhibited the elongation of stearoyl- or arachidoyl-CoA by [2-14C]-malonyl-CoA in leek microsomes from Allium porrum. Although the precise mode of interaction of indanofan at the molecular level is not completely clarified by the present study, it is concluded that indanofan and analogs act as inhibitor of the elongase enzyme involved in de novo biosynthesis of fatty acids with an alkyl chain longer than C18, called very-long-chain fatty acids (VLCFAs). For a strong inhibition of VLCFA formation chloro substituents at the benzene ring and the oxirane group were necessary. Furthermore, the greenhouse test showed strong activity for indanofan and its analogs, and the scores coincided with cell-free elongation inhibition. The cell-free assay, however, failed to indicate any activity for an analog having a methylene instead of the oxirane group, while both Digitaria ciliaris and Echinochloa oryzicola were killed with 1 kg a.i./ha. This finding cannot be discussed because the applied use rate of 1 kg a.i./ha is too high to allow for a score differentiation. For high concentrations of this compound additional unknown inhibitory effects may be involved besides fatty acid elongation.

Acyl Coenzyme A↗

PubMedDate not supplied

Spontaneous thrombosis of a giant intracavernous internal carotid artery aneurysm and ipsilateral internal carotid artery occlusion.

A 75-year-old man who had suffered from right visual disturbance for 10 years suddenly experienced right cavernous sinus syndrome. Magnetic resonance imaging revealed a giant thrombosed aneurysm in the right cavernous sinus extending to the right middle cranial fossa. Digital subtraction angiography disclosed occlusion of the right internal carotid artery at the petrous portion and good cross filling in the right-sided circulation through the anterior communicating artery. There was no filling of the aneurysm. In this case, the mechanism of parent artery occlusion is unclear, but direct compression and stretching of the parent artery by the aneurysm may be involved.

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PubMedDate not supplied

Duplication of distal part of the basilar artery.

We report a case of duplication or fenestration of the distal part of the basilar artery with Shy-Drager syndrome. Duplication and fenestration of the basilar artery are discussed, and a review of embryologic development is presented.

Angiography, Digital Subtraction↗

PubMedDate not supplied

Endovascular treatment of anterior cerebral artery aneurysms using Guglielmi detachable coils: mid-term clinical evaluation.

PURPOSE: Clinical and angiographic evaluations were performed in 19 consecutive patients with anterior communicating artery (ACoA) aneurysms treated by Guglielmi detachable coil (GDC) embolization between March 1997 and April 1999. METHODS: The angiographic criteria for endovascular treatment were 1) small (< 15 mm) aneurysm with a neck smaller than the fundus and 2) distinguishable aneurysm neck and relationship to the parent artery. Initially, we also included patients with anticipated surgical difficulties. These criteria were later expanded to include patients with conditions amenable to surgical clipping. Eleven patients presented with subarachnoid hemorrhage (SAH), and eight patients were asymptomatic. The most recent clinical follow-up was obtained by telephone interview with the patients and with their close relatives, to examine post-treatment personality changes. RESULTS: Complete obliteration (68%) or near-complete obliteration (neck remnant) (32%) of the ACoA aneurysm was achieved in all patients. Six-month follow-up angiography performed in 15 patients demonstrated no recurrence of aneurysms. The clinical outcome was good recovery in 15 (80%), moderately disabled in one (5%), vegetative survival in one (5%), and death in two (10%). The patients who had good recovery did not demonstarate significant personality or behavioral change. No late rebleeding had occurred at the time of writing, a minimum of 33 months postoperatively. CONCLUSION: The outcome of endovascular treatment of ACoA aneurysms was satisfactory, especially in post-treatment psychosocial sequelae.

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PubMedDate not supplied

Internal carotid aneurysms presenting with mass effect symptoms of cranial nerve dysfunction: efficacy and imitations of endosaccular embolization with GDC.

OBJECTIVE: The authors report a retrospective analysis of their experience in the endosaccular embolization of internal carotid aneurysms which caused mass effect symptoms of cranial nerves (CN) and review the efficacy and limitations of this technique. METHODS: Between April 1997 and August 2002, 12 internal carotid aneurysms that caused mass effect symptoms of CN were treated by endosaccular GDC embolization with parent artery preservation. The locations were the cavernous internal carotid artery (CV) in six patients, carotid-ophthalmic artery (CO) in two patients, and posterior communicating artery (PCo) in four patients. The angiographical size of the aneurysms ranged from 6 to 20 mm, with a mean of 13.3 mm. Duration of symptoms ranged from 0.5 to 120 months, with a mean of 13.7 months. All aneurysms were treated by endosaccular guglielmi detachable coil (GDC) embolization with preservation of the internal carotid artery. RESULTS: Five patients (42%) had complete resolution of symptoms, four (33%) had significant improvement of symptoms, and three (25%) were unchanged. Immediate posttreatment angiographic studies revealed neck remnant (NR) in nine patients and dome filling (DF) in three patients. In one patient (case 10), the resolved symptoms became worse 29 months later. Follow-up angiograms were obtained in 10 patients, and recanalization was observed in four of them (40%). Transient thrombotic complication occurred in only one patient. The group with resolution or improvement of symptoms demonstrated a shorter duration of symptoms before GDC treatment (< or = 12 months). CONCLUSION: Even subtotal endosaccular embolization of aneurysms may reduce mass effect symptoms of cranial nerves. However, careful follow-up is needed because subtotal occlusion carries a future risk of growth.

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PubMedDate not supplied

Dural AVFs of the cavernous sinus: transvenous embolization using a direct superficial temporal vein approach.

We present an alternative endovascular approach to treat dural anterio-venous fistulas (AVFs) of the cavernous sinus that drain only into the superior ophthalmic vein. Two cases of dural AVFs of the cavernous sinus producing increased intraocular pressure and diminishing visual acuity are reported. The cavernous sinus was accessed via the direct superficial temporal vein approach through the superior ophthalmic vein. Successful embolization was documented radiographically and clinically.

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