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Biomedical subjects

Kenji Ohtsuka

Publications and source records attributed to Kenji Ohtsuka.

At least 37 records · Page 2Linked to original sources
PubMed2003

Macular hole formation following ruptured retinal arterial macroaneurysm.

PURPOSE: To report four cases of macular hole formation following ruptured retinal arterial macroaneurysm. DESIGN: Case-control study. METHODS: Review of clinical records of 75 consecutive eyes (73 patients) with macroaneurysm. Macroaneurysms were confirmed using either fluorescein angiography or indocyanine green angiography or both that indicated a telangiectatic retinal vascular change. Clinical data of patients with macroaneurysm with and without macular hole (MH) formation were compared retrospectively. RESULTS: Of 75 eyes, four (5.3%; four patients) with macroaneurysm had a macular hole. In one of the four eyes, a macular hole was detected 2 days after the rupture. The distance from the macroaneurysm to the center of the fovea was significantly closer in the four eyes with a macular hole (MH group, 1.1 +/- 0.4 (mean +/- standard deviation [SD]) disk diameter) than in the 71 eyes without a macular hole (non-MH group, 1.9 +/- 0.9 disk diameter) (P =.0196). The incidence of subretinal hemorrhage in the macula was significantly greater in the MH group (100%) than in the non-MH group (35.2%) (P =.0195). CONCLUSIONS: Macular hole formation associated with ruptured macroaneurysm is not as uncommon as previously thought. We suggest that there might be early onset of macular hole formation following ruptured macroaneurysm. Macroaneurysms with early-onset macular hole are present near the center of the macula and are accompanied by subretinal hemorrhage in the macula.

Aged↗
PubMed2003

Rhegmatogenous retinal detachment after rupture of retinal arterial macroaneurysm.

PURPOSE: To report two cases of rhegmatogenous retinal detachment following rupture of retinal arterial macroaneurysm. DESIGN: Observational case report. METHODS: Review of clinical records of 75 consecutive eyes (73 patients) with macroaneurysm. RESULTS: Ruptured macroaneurysm was present in 68 of the 75 eyes, and rhegmatogenous retinal detachment developed spontaneously in 2 (2.9%) of the 68 eyes. In the 2 eyes with retinal detachment, there were no predisposing lesions to retinal detachment and the detachment occurred either 2 weeks or 1 month after the rupture of a macroaneurysm. Retinal detachment and posterior vitreous detachment developed simultaneously after bleeding from the macroaneurysm spread into the vitreous in 1 eye. CONCLUSIONS: We report the occurrence of retinal detachment after macroaneurysmal rupture. Detailed fun-dus examination is required to detect retinal detachment in the follow-up of patients with ruptured macroaneurysm.

Aged↗
PubMed2003

Invasive thymoma with paraneoplastic retinopathy.

A 60-year-old man was admitted for progressive visual loss in both eyes. He was diagnosed with retinopathy and chest computed tomography revealed an invasive thymoma. In western blot analysis, serum autoantibodies against recoverin, photoreceptor-specific calcium-binding protein, and heat shock cognate protein 70 which were identified as the cause of cancer-associated retinopathy (CAR). Immunofluorescence staining showed that thymoma cells also expressed recoverin. These observations strongly suggested that similar pathogenesis of CAR was involved in the presented case.

Biomarkers, Tumor↗
PubMed2003

[Epidemic nosocomial keratoconjunctivitis caused by adenovirus type 4].

PURPOSE: To evaluate the clinical features of nosocomial epidemic keratoconjunctivitis(EKC) occurring in the ophthalmology ward of Sapporo Medical University Hospital and to devise preventive measures for it. MATERIALS AND METHODS: We studied the symptoms and clinical course of 2 patients who had EKC and 16 patients who had EKC caused by nosocomial infections in our hospital. We attempted to detect adenovirus antigen and viral DNA from conjunctival swabs and also to isolate the virus. RESULTS: The clinical symptoms of EKC were conjunctival hyperemia in 18 patients(100%), conjunctival follicles in 11 patients (61.1%), discharge in 8 patients(44.4%), superficial punctate keratopathy in 7 patients(38.9%), swelling of the eyelids in 3 patients(16.7%), and fever in 3 patients(16.7%). 72% were positive for Adeno-check. Adenovirus type 4 was isolated from the conjunctival swabs. We considered that the route of hospital infection was infection from the doctor's hands, from eye drops, and from contact lenses. We disclosed that nosocomical EKC had occurred in our hospital. The hospital infection was eliminated by closing the ophthalmology ward and sterilizing instruments and washing hands. CONCLUSIONS: The delay of proper measures increased the risk of nosocomical infection. We recognized the importance of careful observation of patients and immediate preventive efforts in nosocomical infection.

Adenovirus Infections, Human↗
PubMed2002

Accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus.

PURPOSE: To report a patient who developed accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus. DESIGN: Observational case report. METHODS: A 30-year-old right-handed man experienced sudden onset of diplopia and blurred vision at near vision. RESULTS: The patient showed accommodation and convergence palsy. Magnetic resonance imaging revealed lesions located in the bilateral rostral superior colliculus. CONCLUSION: These findings suggest that the rostral superior colliculus is involved in the control of accommodation and vergence eye movements.

Accommodation, Ocular↗
PubMed2002

Anatomy of the tonsillar bed: topographical relationship between the palatine tonsil and the lingual branch of the glossopharyngeal nerve.

Taste disturbance may result from injury to the lingual branch of the glossopharyngeal nerve (LBGN) during tonsillectomy. Because an understanding of the anatomy of this nerve is required in order to avoid injuring it, a gross, histologic anatomic study was undertaken of the topographical relationship between the LBGN and the muscle layer of the palatine tonsillar bed. Evaluation of 107 sides of 83 Japanese adult cadavers (aged 27-88 years) confirmed that the muscular composition and lamination of the tonsillar bed do not change with age or pathological conditions such as inflammation. In about a quarter (23.4%) of cases, the LBGN traveled inferior to the styloglossus muscle and lateral to the superior constrictor pharyngeal muscle over its whole course to the base of the tongue, so that the palatine tonsil was clearly separated from the LBGN. In 55.1% of cases, however, the muscle lining of the tonsillar bed was discontinuous and thin muscle bundles, derived from the stylopharyngeus, palatopharyngeus or superior constrictor pharyngeal muscle, partially covered the tonsillar capsule externally. Moreover, in 21.5% of cases the LBGN was firmly adherent to the tonsillar capsule, due to the complete absence of muscles lining the tonsillar bed. In these cases, and also probably in a similar percentage of patients undergoing tonsillectomy, taste disturbance may occur on removal of the hypertrophic tonsillar capsule. Therefore, minimal disturbance of the tonsillar bed is recommended in all cases of tonsillectomy.

Adult↗
PubMed2002

Neurotrophic factor receptors in epiretinal membranes after human diabetic retinopathy.

OBJECTIVE: Formation of epiretinal membranes (ERMs) in the posterior fundus results in progressive deterioration of vision. ERMs have been associated with numerous clinical conditions, including proliferative diabetic retinopathy (PDR), but its pathogenic mechanisms are still unknown. This study was conducted to determine whether neurotrophic factor receptors (tyrosine kinase receptors trkA, trkB, and trkC; low-affinity neurotrophin [NT] receptor p75 [p75(NTR)]; glial cell line-derived neurotrophic factor receptor-alpha1 [GFR alpha 1] and GFR alpha 2; and Ret) are involved in the formation of ERMs after PDR. RESEARCH DESIGN AND METHODS: ERM samples were obtained by vitrectomy from 19 subjects with PDR aged 57 +/- 8 years with 17 +/- 8 years of diabetes and 15 subjects with idiopathic ERM. They were processed for RT-PCR analysis. In addition, 11 ERM samples from PDR patients aged 47 +/- 18 years with 13 +/- 4 years of diabetes were processed for immunohistochemical analysis. RESULTS: Expressions of trkA, trkB, trkC, p75(NTR), and Ret mRNAs were similar in both groups. In contrast, GFR alpha 2 expression levels were significantly higher (17 of 19 vs. 2 of 15 subjects in idiopathic ERM, P < 0.0001) in PDR subjects. Accordingly, immunohistochemical analysis revealed expression of GFR alpha 2 protein in all of the 11 ERMs derived from PDR patients, and that region was double-labeled with glial cell-specific markers. On the other hand, GFR alpha 1 expression was lower (8 of 19 vs. 12 of 15 subjects with idiopathic ERM, P = 0.0258) in PDR subjects. CONCLUSIONS: These results suggest a possibility that glial cell line-derived neurotrophic factor receptor (GDNF) subtypes are differently involved in the formation of ERMs.

Adult↗
PubMedDate not supplied

N-acetylaspartate concentration in the chiasm measured by in vivo proton magnetic resonance spectroscopy.

PURPOSE: To measure the concentration of N-acetylaspartate (NAA) in the chiasm of both normal controls and patients with chiasmal optic neuritis by in vivo proton magnetic resonance spectroscopy (1H-MRS). METHODS: Ten normal subjects (age range, 22 to 40 years; mean, 31 years; seven men and three women) and two patients with chiasmal optic neuritis were examined at the Sapporo Medical University Hospital. Localized 1H-MRS spectra of the chiasm were obtained using a whole-body 1.5-T magnetic resonance system. RESULTS: 1H-MRS spectra of the chiasm were obtained in all subjects. The level of NAA concentration in the optic chiasm was 15.73 +/- 1.43 mM (mean +/- SD) in normal subjects. In contrast, the NAA levels in the two patients with chiasmal optic neuritis were significantly lower (P < 0.001). The level of NAA in the two patients was significantly increased after improvement of visual acuity and visual fields following corticosteroid pulse therapy. CONCLUSIONS: These results suggest that 1H-MRS enables us to estimate the concentration of NAA in the chiasm. The NAA concentration in the optic nerve measured by 1H-MRS may be a new clinical parameter to monitor the axonal damage following optic neuritis.

Adult↗
PubMedDate not supplied

A review of 244 orbital tumors in Japanese patients during a 21-year period: origins and locations.

PURPOSE: To review 244 cases of orbital tumors to determine the distribution of patient age, pathology, and tumor origin and location. METHODS: We reviewed cases of histopathologically or radiologically verified orbital tumors at our institution from 1981 through 2002, and studied the distribution of patient age, pathology, origin of tumors, and tumor location in the orbit in 244 consecutive patients (aged from 0 to 90 years, mean, 48.7 years; 114 men, 130 women). RESULTS: Among the 244 cases, 213 (89%) were primary orbital tumors, 23 (9%) were secondary tumors originating in contiguous spaces, and 8 (2%) were metastatic tumors. Regarding the location in the orbit, 122 tumors (50%) were extraconal, 36 (15%) were intraconal, and 86 (35%) were in the lacrimal gland area. The common tumors were reactive lymphoid hyperplasia (22%) and malignant lymphoma (20%) in the extraconal area; cavernous hemangioma (25%), optic nerve glioma (14%), and optic nerve sheath meningioma (14%) in the intraconal area; and malignant lymphoma (40%) and pleomorphic adenoma (24%) in the lacrimal gland area. The age distribution of the 244 patients exhibited two peaks, at 0 to 9 years and 60 to 69 years. In the 0- to 9-year-old patients, the most common tumors were dermoid cyst (26%), optic nerve glioma (11%), capillary hemangioma (11%), and hemorrhagic lymphangioma (11%). On the other hand, in patients over 40 years of age, the common tumors were malignant lymphoma (31%), orbital pseudotumor (24%), pleomorphic adenoma (10%), and cavernous hemangioma (9%). CONCLUSIONS: The pathologic profiles of orbital tumors were characterized according to patient age and the location of the tumor in the orbit. The age of onset, tumor location, and radiological findings provide us with important information for the diagnosis of a tumor prior to biopsy or tumor resection and for the determination of the treatment strategy.

Adolescent↗
PubMedDate not supplied

Transition from upbeat to downbeat nystagmus observed in a patient with Wernicke's encephalopathy.

BACKGROUND: We report an unusual case of Wernicke's encephalopathy presenting with transient upbeat nystagmus that changed to a persistent downbeat nystagmus. CASE: A 27-year-old man presented with upbeat nystagmus. Three months earlier, he had been diagnosed with Wernicke's encephalopathy after fasting for a month. OBSERVATIONS: This diagnosis was supported by his symptoms (ataxia, a confused state). Clinical recovery followed thiamine therapy. His upbeat nystagmus had linear slow phases with average amplitude and frequency (+/-SD) during fixation straight ahead of 2.8 +/- 0.7 degrees and 4.6 +/- 2.2 Hz, respectively. Two months later, the primary position upbeat nystagmus had diminished and downbeat nystagmus (0.9 +/- 0.5 degrees and 3.2 +/- 0.7 Hz on average) for a 20 degrees downward gaze had developed. Then, 8 months later, he showed only downbeat nystagmus, which obeyed Alexander's law. His primary position downbeat nystagmus was completely suppressed by clonazepam, a gamma-aminobutyric acid (GABA) agonist. CONCLUSIONS: Owing to an underlying central vestibular imbalance, even after the recovery of acute neurological symptoms, Wernicke's encephalopathy can be complicated by persistent downbeat nystagmus, which can be treated by a GABA agonist.

Adult↗