Naoya Fujimoto
Chiba University
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Featured researches published by Naoya Fujimoto.
Neuroreport | 2002
Toshiyuki Oshitari; Naoya Fujimoto; Emiko Adachi-Usami
Some clinical reports indicate that exogenous CDP-choline (citicoline) may have a therapeutic effect in patients with glaucoma. However, the precise effect of citicoline on damaged retinal ganglion cells (RGCs) remains to be explained. We performed tissue culture of mouse retinal explants and investigated the effect of citicoline on damaged RGCs by the quantitative analysis of TdT-dUTP terminal nick-end labeling (TUNEL) staining and the assessment of the number of regenerating neurites. The TUNEL-positive ratio in 0.1–10 μmol/l citicoline-treated retina was very low, and the number of regenerating neurites increased more than in control retina. Our findings suggest that citicoline has a protective effect on damaged RGCs in tissue culture of retina.
Eye | 2002
Naoya Fujimoto; N Saeki; Osamu Miyauchi; Emiko Adachi-Usami
Purpose To determine new criteria for early detection of temporal hemianopia in patients with asymptomatic pituitary tumor.Methods Fifteen patients without visual symptoms had pituitary tumor and subtle defects or normal visual fields by Goldmann perimetry. Twelve patients with visual symptoms had pituitary adenoma and visual field defects detected by Goldmann perimetry. All were examined by automated perimetry. The relationship between the tumor and the optic chiasm was graded by magnetic resonance imaging (MRI) on a scale of 0–4. Grade number increased with extent of compression. Temporal hemianopia observed by automated perimetry was estimated from normal data (52 normal fields). Vertical step was determined from the number of adjacent pairs along the midline; sensitivity was lower in the temporal field than in the nasal field. Temporal depression was calculated by the quadrant sum of sensitivity.Results All patients with symptomatic pituitary adenoma had vertical step and temporal depression in the upper field. Nine of 15 patients without visual symptoms had vertical step or temporal depression. Of nine patients with temporal hemianopia, two of four patients had grade 1 compression, three of five had grade 2, and four of four had grade 3.Conclusion New criteria by automated perimetry could detect temporal hemianopia in patients with asymptomatic pituitary tumor.
Clinical Neurology and Neurosurgery | 2003
Naokatsu Saeki; Naoya Fujimoto; Motoo Kubota; Akira Yamaura
Two rare cases with a partial lesion of the lateral geniculate body (LGB) presumably due to ischemia are demonstrated on high resolution MR imaging. A 62-year-old woman (case 1) presented with left homonymous superior quadrantanopia on Goldmann perimetry. Heavily T2 weighted MR images showed a localized lesion at the lateral portion of the LGB. The visual field defect was macular and horizontal meridian sparing and persisted for 9 years. A 49-year-old woman (case 2) presented with a sudden onset of left homonymous horizontal sectoranopia on Humphrey automated perimetry and heavily T2 weighted images demonstrated a lesion localized at the more medial part of the right LGB. Axons originating from inferior, central and superior retina are essentially located laterally, centrally and medially, respectively, in the LGB, based on the electrophysiological studies of animal experiments and this observation has been applied to humans. This study radiologically shows that a discrete lateral lesion of the LGB produced homonymous upper quadrantanopia in case 1, whereas a more medially located lesion produced homonymous sectoranopia in case 2, and reveals that the axons originating from inferior retina are located more laterally than those from central retina in the human LGB.
Acta Neurochirurgica | 2002
N. Saeki; Hisayuki Murai; Motoo Kubota; Naoya Fujimoto; Toshihiko Iuchi; Akira Yamaura; Kenro Sunami
Summary Objective. Location of anterior optic pathways in sellar and parasellar tumours was preoperatively evaluated, by use of heavily T2 weighted MR images. Methods. Heavily T2 and conventional T1 weighted images were studied in 20 patients with sellar and parasellar tumours who underwent craniotomy. Pathology revealed pituitary adenoma in 5 patients, craniopharyngioma in 8 and parasellar meningioma in 7. Maximum sizes ranged from 15 mm to 58 mm. Sequence parameters of TR/TE for heavily T2 weighted and T1 weighted images were 5800/220 msec and 600/20 msec, respectively, and slice thickness was 3 mm for both. Results. The anterior optic pathway was detected in 95% on heavily T2 weighted images and 50% on T1 weighted images. All preoperative heavily T2 weighted images were compatible with operative findings. The optic chiasms were most commonly supero-posterior in pituitary adenomas, anterior (prefixed) in craniopharyngiomas and posterior in meningiomas. The optic nerves were commonly located superior or lateral to the tumours. However, parasellar meningiomas, off the midline, revealed the optic nerves in various locations, depending on the tumour origin. In such tumours, heavily T2 weighted images provided surgical information on the width of the working space through prechiasmal and/or optico-carotid spaces in the pterional approach. Spatial relation of the tumours to the lamina terminalis, anterior commissure and anterior communicating artery complex was clearly shown in craniopharyngioma patients, who underwent the anterior interhemispheric approach. Conclusion. Heavily T2 weighted MR images are useful in determining the location of optic pathways and surgical approach and in individual prediction of the anatomy for even large sellar and parasellar tumours.
British Journal of Neurosurgery | 2002
M. Eda; N. Saeki; Naoya Fujimoto; K. Sunami
The objective of the investigation was to understand preoperatively the detailed anatomical relationship of large pituitary adenomas to surrounding structures, using the heavily T2-weighted reversed (T2R) MR images. This study consisted of 28 patients with pituitary adenoma, presenting with visual disturbance. The MRI scanner used was a Gyroscan ACSNT 1.5T and the slice thickness of the image was 3 mm with 0.5 mm interslice gap. The relation of pituitary adenoma to optic pathway and to the degree of visual field defect was assessed. Relations of the optic chiasm to adenoma were classified into three types: anterior, superior and posterior. The optic chiasm was directly visualized and identifiable in all patients studied. It was located anterior in four cases, superior in 22 and posterior in two in relation to the adenoma. Its location was further confirmed by the anatomical delineation of surrounding structures such as anterior commissure and lamina terminalis. Optic nerve or tract was unidentifiable in one case, for each category. Detectability of each optic component was higher on T2R images than on conventional T1-weighted images. The adenoma extended into and in front of the third ventricle in anterior and posterior types, respectively. The anterior communicating artery complex and the optic pathway were relocated together in anterior and superior types, and were separated in the posterior type. In a case of the posterior type, the complex was sectioned to obtain a wider surgical field during anterior interhemispheric approach. While degrees of visual field defect were proportional to tumour size in the superior type, they were unrelated in the anterior and posterior types. On choosing a transcranial approach, the transcallosal route is unsuitable for an adenoma of posterior type, which extends in front of the third ventricle. This preoperative MRI information makes it possible to visualize directly the optic pathway even in huge adenomas, and is useful in predicting surgical anatomy and selecting a proper surgical approach.
International Ophthalmology | 2007
Tsuyoshi Kimura; Atsushi Mizota; Naoya Fujimoto; Yoshihiko Tsuyama
AbstractPurposeTo correlate the ophthalmoscopic and histological findings on human retinal blood vessels of patients with sclerosis and hypertension, respectively.MethodsOphthalmoscopy, light microscopy, and transmission and scanning electron microscopy with histochemical staining were performed on eyes obtained from patients with a malignant orbital tumor, with absolute glaucoma, or with hypertensive retinopathy.ResultsThe retinal arteries in aged patients with ophthalmoscopic sclerotic blood vessels had walls in which the smooth muscle cells had been replaced by collagen fibers, proteoglycan filaments, and ruthenium red-positive materials. The venous blood columns were hidden by numerous swollen nerve fibers and extending Müller cell processes. In a patient with accelerated hypertensive retinopathy, some of the muscle cells in the arteriolar walls were edematous. Focal and generalized narrowing of the retinal arteries appeared to be caused by a true functional constriction of the smooth muscle cells in the walls.ConclusionsThe ophthalmoscopic signs, such as reflection of the retinal arterial blood column and crossing phenomena, were supported by sclerotic manifestations clearly visible upon histological examination. There were some organic changes in the retinal arteries in a patient with accelerated hypertensive retinopathy, but the ophthalmoscopic narrowings appeared to result from a functional constriction of the smooth muscle cells in these vessels.
British Journal of Neurosurgery | 2001
N. Saeki; Hisayuki Murai; Motoo Kubota; Naoya Fujimoto
The MRI finding of oedema along the optic tract has been reported in patients with craniopharyngioma, as a useful diagnostic sign among common pituitary tumours. We report two patients with pituitary metastasis with this MRI finding. A 59-year-old woman and a 54-year-old man had diabetes insipidus and extraocular impairment due to a pituitary metastasis from adenocarcinoma of lung and colon, respectively. Several months later, they noticed rapidly deteriorating visual field and acuity impairment. MRI revealed enlarged pituitary mass accompanied by marked oedema along the bilateral optic tracts. To our knowledge, this is the first MRI report of oedema along the optic pathway due to pituitary metastasis. Our cases and review of literature indicate that this MRI sign is non-specific. Appearance of the oedema well corresponded to the initiation of visual complaint, which make a good contrast to reported clinical presentations of craniopharyngioma. Clinical significance and pathomechanism of this MRI sign are discussed.
Acta Ophthalmologica | 2009
Naoya Fujimoto; Emiko Adachi-Usami
Abstract. Sensitivity variation in normal subjects was studied, by changing the number of test locations and the size of test fields on automated perimetry. Using the Sargon program, four different programs that differed in the number of test points or in the size of test field were made. Mean sensitivity and short‐term fluctuation were calculated from the same test points of each program. The program with the fewest points and the smallest size produced the greatest sensitivity and the least fluctuation. Our results showed that the number of test points and the size of test field affected the sensitivity and its reproducibility in automated perimetry.
Japanese Journal of Ophthalmology | 2003
Yoshinori Igarashi; Eiju Sato; Akira Ito; Osamu Miyauchi; Mitsuya Ikejiri; Tadao Hanawa; Yoshihiko Tsuyama; Atsushi Mizota; Naoya Fujimoto; Emiko Adachi-Usami
PURPOSE To determine the psychological state and personality traits of patients with retinitis pigmentosa (RP) or glaucoma so that a closer and better relationship can be developed with the patients. METHODS The Yatabe-Guilford personality test was administered to 75 RP patients and 42 glaucoma patients. The latter group included 29 cases of primary open-angle glaucoma, 6 of primary angle-closure glaucoma, and 7 of normal-tension glaucoma. The patients were being treated at the Department of Ophthalmology, Chiba University Hospital. As controls, 47 age-matched volunteers were tested. RESULTS A comparison of these three groups showed that the proportions of patients with cyclic tendency, rhathymia, and lack of cooperativeness traits were significantly higher in the RP group than in the glaucoma group. The lack of cooperativeness value was especially higher in the RP than in the glaucoma group and the control group (Fisher exact test, P <.05). On the other hand, the nervousness value was significantly higher in the glaucoma group than in the RP group and than in controls (Fisher exact test, P <.05). Factors of sex, age, type of disease, corrected visual acuity, and central visual fields did not influence the profiles of the RP and glaucoma groups. CONCLUSION RP patients had relatively well-stabilized personalities and were optimistic, while glaucoma patients tended toward nervousness in comparison with RP patients and controls.
British Journal of Neurosurgery | 2001
N. Saeki; Hisayuki Murai; Motoo Kubota; Naoya Fujimoto; Akira Yamaura
Long-term posttreatment Karnofsky Performance Status (KPS) and neurological status of 16 patients with neurohypophyseal (NH) germinomas were retrospectively analysed, in order to deduce the best treatment modality to achieve a good outcome. The average age at treatment was 15.5 years (rouge 6‘26) and they were followed up for 107.3 months (26‘209). The KPS averaged 81.5 (0‘100). Three patients were below 60 in the KPS. The first one had hemiparesis due to a delayed cerebrovascular accident (CVA), and the second became indifferent and inactive with recent memory loss. The third died from marginal recurrence of tumour and subsequent systemic metastasis. The low scores were all more or less attributable to complications related to irradiation: delayed CVA, diffuse cortical atrophy and inappropriate selection of irradiation field, respectively. The second case had the tumour origin at the hypothalamus, which indicates intraparenchymal tumour location as another factor to worsen the quality of life (QOL). Visual field and acuity, and EOM impairment were observed in eight and five patients, respectively. It improved in all patients but one. The visual and EOM dysfunction recovered satisfactorily and was not a disabling factor. The intraparenchymal lesion resulting in hemiparesis and higher cortical dysfunction due to either irradiation-related complications or tumour invasion is a major determining factor of lower KPS. Irradiation related complications are considered to be avoidable by reducing radiation dosage with appropriate chemotherapy and/or proper selection of irradiation field. Patients with smaller tumour size of less than 20 mm had higher KPS. Accordingly, repeated studies of tumour markers and neuroimages are required in patients with idiopathic diabetes insipidis, in order to detect the tumour, if present, at the small-sized and early stage.