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Biomedical subjects

M Kiyosawa

Publications and source records attributed to M Kiyosawa.

69 records · Page 4Linked to original sources
PubMed1985

Gyrate atrophy of choroid and retina complicated by vitreous hemorrhage.

We describe two patients with gyrate atrophy of the choroid and retina who suffered from vitreous hemorrhages in adolescence. The diagnosis of gyrate atrophy was confirmed biochemically and clinically; hyperornithinemia and a deficiency of ornithine ketoacid transaminase were confirmed biochemically. Typical fundus changes of scalloped chorioretinal atrophies with sharp margins, deteriorated dark adaptation, non-recordable electroretinogram, flat electrooculogram, and constricted visual fields were noted. We believe that the vitreous hemorrhage is an ocular complication in this disorder.

Adult↗
PubMed1984

Ciliary and retinal changes in myotonic dystrophy.

We examined 15 patients with myotonic dystrophy by cycloscopy, ophthalmoscopy, and fluorescein angiography. In six cases, we found depigmentation in the relatively short ciliary processes, which may account for ocular hypotony in this disorder. Eight of the patients had retinal lesions, three with butterfly-shaped dystrophy, two with reticular dystrophy, and three with peripheral yellow flecks. These lesions were biomicroscopically at the level of the retinal pigment epithelium or in the deep retinal layer and did not substantially alter visual functions. Psychophysical and electrophysiologic test results were normal or only slightly affected. The butterfly-shaped and reticular dystrophies in myotonic dystrophy may be variant forms of patterned dystrophy of the retinal pigment epithelium. The peripheral yellow flecks in a stone-wall configuration noted in this disorder are particularly unique and, to our knowledge, have not been documented previously.

Adolescent↗
PubMed1983

[Administration of mannitol for severe superior sagittal sinus thrombosis].

A cured case of superior sagittal sinus thrombosis is reported. The patient, a 26-year-old man, also displayed severe complications such as hemorrhagic infarction and status epilepticus. Although his prognosis was considered to be extremely poor, conservative treatment, with mannitol, steroid, anticonvulsants, etc. was effective, and he was discharged without any neurological deficit. This report discusses the clinical course, CT findings, angiographical findings and regional cerebral blood flow (rCBF). At first, CT showed no abnormal findings, but hemorrhagic infarction was detected on the 3rd day after the onset. Follow-up CT showed subcortical low density area, hemorrhagic infarction with perifocal brain edema, midline shift etc; the focus of hemorrhagic infarction was almost absorbed 2.5 months after the onset. Cerebral angiogram showed not only the obstruction of the superior sagittal sinus but also that of cortical veins of cerebral convexity at first. Follow-up angiogram showed the development of collateral circulations such as deep cerebral, ophthalmic and emissary veins. On CBF study, low rCBF at the bilateral parasagittal region was observed, but marked increase of rCBF was measured in the parasagittal region, especially at the site of hemorrhagic infarction after the administration of 20% mannitol. We, therefore, consider mannitol as an effective agent for the treatment of cerebral sino-venous thrombosis.

Adult↗
PubMedDate not supplied

Neuroreceptor bindings and synaptic activity in visual system of monocularly enucleated rat.

PURPOSE: To study the changes in the distribution of postsynaptic benzodiazepine (BDZ) and presynaptic adenosine A(1) (AA(1)) receptors in the superior colliculus (SC) and visual cortex (VC) of rats following monocular enucleation. METHODS: The right eyes of 6-week-old Long-Evans rats were enucleated and ex vivo autoradiography was performed on the SC and VC obtained at different times up to 8 weeks after the enucleation. [14C]deoxyglucose was used to detect glucose metabolism, and [11C]flumazenil and [1-methyl-(11)C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine ([11C]MPDX) were used to map BDZ and AA(1) receptors, respectively. The receptor-specific binding for 11C was determined, and 11C and 14C activities were evaluated separately in the same tissue by a double tracing method. RESULTS: The uptake of [14C]deoxyglucose in the SC was depressed immediately after enucleation and gradually recovered. The binding of [11C]flumazenil to BDZ receptors in the contralateral SC was increased at week 2, and then returned to the pre-enucleation levels. The uptake of [11C]MPDX by the AA(1) receptors in the contralateral SC decreased by about 67% on day 5 after enucleation and remained low thereafter. In the contralateral VC, the uptake of [14C]deoxyglucose decreased immediately after the enucleation followed by a gradual recovery, whereas the uptake of [11C]flumazenil and [11C]MPDX was not altered. CONCLUSIONS: The axon degeneration related decrease of the AA(1) receptor density resulted in a transient up-regulation of postsynaptic BDZ receptor density in monocularly enucleated adult rats. These results suggest that these radioligands can be used to study the distribution of the postsynaptic BDZ and presynaptic AA(1) receptors in the visual system and can probably be applied to the human visual system for positron emission tomography.

Animals↗
PubMedDate not supplied

Cortical blindness following aortic arch surgery.

PURPOSE: To report a patient with Marfan's syndrome in whom cortical blindness occurred after planned circulatory arrest during aortic arch surgery. CASE: A 31-year-old man underwent aortic arch surgery because of an acute aortic dissection due to Marfan's syndrome. He noticed poor vision after surgery, although his pupillary reflexes and fundi appeared normal. Magnetic resonance imaging (MRI) and positron emission tomography (PET) were performed 2 years and 9 months after his operation. RESULTS: The MRI revealed cortical atrophy in the occipital cortex, and PET scans with fluorodeoxy glucose revealed extreme glucose hypometabolism in the occipital cortex. The atrophy reflected cortical laminar necrosis that presumably occurred during the planned circulatory arrest to the brain during the surgery. CONCLUSION: It is occasionally difficult to diagnose cortical blindness with MRI, especially at the acute stage. We could find significant hypometabolism of the occipital cortex using PET.

Adult↗
PubMedDate not supplied

Clinicopathological report of retinitis pigmentosa with vitamin E deficiency caused by mutation of the alpha-tocopherol transfer protein gene.

PURPOSE: To discuss the clinicopathological findings in a patient with retinitis pigmentosa (RP) accompanied by a vitamin E deficiency caused by an H101Q mutation in the alpha-tocopherol transfer protein (alpha-TTP) gene. CASE: The clinical course of this patient was followed by conventional ophthalmological examinations over a 3-year period. After the patient died from pancreatic cancer, the eyes were obtained, and examined by light and electron microscopy. OBSERVATIONS: The patient complained of night blindness subsequent to adult-onset ataxia, although the ataxia was very mild. His visual acuity was 0.6 OU, and ophthalmoscopy revealed RP sine pigmento. Ring scotomas were detected, and the electroretinography, electro-oculography, and dark-adaptation were altered. Fluorescein angiography showed granular hyperfluorescence around the macula. No progression of the visual and neurological symptoms was observed during the 10 years he was taking oral vitamin E. Histopathological examination revealed the loss of the outer and inner segments of the photoreceptors in the area corresponding to the ring scotoma, as well as a disorganization and shortening of the outer segments in the peripheral retina. CONCLUSIONS: We conclude that the clinical and pathological findings in the eyes of this patient having RP with vitamin E deficiency caused by an H101Q mutation are similar to those of common autosomal recessive RP. However, special attention is required in making a diagnosis of RP with vitamin E deficiency because RP with vitamin E deficiency is medically treatable. The mild Friedreich-type ataxia accompanying the RP may be helpful in identifying this disease.

Carrier Proteins↗
PubMedDate not supplied

Multicenter clinical trial for evaluating methylprednisolone pulse treatment of idiopathic optic neuritis in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG).

BACKGROUND: A randomized, controlled clinical trial was conducted in 1991 to compare an intravenous megadose of methylprednisolone with a control drug (mecobalamin) for treating acute idiopathic optic neuritis. CASES: Sixty-six cases from 22 clinical centers throughout Japan were examined to evaluate the treatment on visual function parameters, such as visual acuity, visual field, color vision, contrast sensitivity, and critical flicker frequency. OBSERVATIONS: The methylprednisolone pulse treatment group showed faster recovery of visual function, particularly the visual acuity at 1 week (P<.05), Humphrey field analyzer mean deviation at 3 weeks (P<.05), and color vision at 1 week (P<.05). Recovery of contrast sensitivity at several different spatial frequencies was significant in the pulse treatment group at 1 (P<.01), 2 (P<.05), and 4 weeks (P<.05) after the start of treatment. Visual function test results at 12 weeks and 1 year were essentially the same in the two treatment groups. Side effects appeared more frequently in the pulse treatment group than in the control (P<.05). CONCLUSIONS: Pulse treatment does not appear effective for idiopathic optic neuritis even though visual function in the pulse treatment group of this trial recovered more quickly during the initial phase compared to the controls. More effective and specific treatment should be established for optic neuritis.

Adolescent↗
PubMedDate not supplied

Baseline features of idiopathic optic neuritis as determined by a multicenter treatment trial in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG).

BACKGROUND: An optic neuritis treatment trial was conducted at 30 clinical centers in Japan using the same protocol. Patient participation was based on: age range of 14-55 years; acute symptoms indicative of unilateral optic neuritis of unknown or demyelinating origin; visual symptoms of 14-day duration or less; relative afferent pupillary defect in affected eye; and normal or swollen optic disc of affected eye. CASES: Initially, 102 patients qualified for participation; baseline data were obtained for analysis from 70 of these patients. Demographic characteristics of Japanese patients with optic neuritis were clarified and compared with those in a US study. OBSERVATIONS: The incidence of ocular or periocular pain and the presence of periventricular plaques were noted to be lower, and the incidence of disc swelling higher, in the Japanese patients, suggesting racial differences in the characteristics of the disease. Such differences may possibly be related to the lower incidence of multiple sclerosis in Japanese patients. The results of visual function tests were virtually the same in both studies. The nonaffected eyes of more than half the patients showed abnormal mean deviation in Humphrey field analysis, as also noted in the US study. CONCLUSIONS: The baseline clinical features of optic neuritis in the Japanese patients have been defined. Some racial differences in the characteristics of the disease may exist.

Adolescent↗
PubMedDate not supplied

Importance of fluorescein angiographic study in evaluating early retinal changes in Takayasu disease.

PURPOSE: To determine the usefulness of fluorescein angiography in studying Takayasu disease. METHODS: We examined 31 eyes in 16 patients with Takayasu disease using indirect ophthalmoscopy, color photography, and fluorescein angiography. Ophthalmoscopic and fluorescein angiographic findings were compared. RESULTS: Fluorescein angiography revealed no additional retinal changes in 10 eyes that had no retinal vein dilatation as seen by indirect ophthalmoscopy. Seven (33%) of 21 eyes that had dilated retinal veins also had additional abnormal findings, such as microaneurysms, arteriovenous shunts, retinal neovascularization, and avascular areas. Some differences in grading the stages of retinopathy were noted with these newly found retinal changes, as compared with the classifications determined by ophthalmoscopy alone. CONCLUSIONS: In Takayasu disease, studying the fundus of patients with fluorescein angiography is particularly important in correctly classifying the stages of retinopathy when the retinal vein appears dilated in ophthalmoscopic observation.

Adult↗