Biomedical subjects

Fumihiko Mabuchi

Publications and source records attributed to Fumihiko Mabuchi.

9 recordsLinked to original sources

PubMed2006

The OPA1 gene polymorphism is associated with normal tension and high tension glaucoma.

PURPOSE: To assess whether genetic polymorphisms of optic atrophy 1 (OPA1) are associated with primary open-angle glaucoma (POAG). DESIGN: Prospective case control association study. METHODS: Japanese patients with normal tension glaucoma (NTG, n = 194), and high tension glaucoma (HTG, n = 191), and 185 control subjects were analyzed for the OPA1 intervening sequence (IVS) 8+4 cystosine thymine (C/T) and IVS 8+32 thymine cystosine (T/C) polymorphisms using pyrosequencing technique. RESULTS: There was a significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the NTG patients and control subjects (P = .0074), and the frequency of the cystosine (C) allele was significantly higher in the NTG patients compared with the control subjects (19.3% vs 11.6%, P = .0036). Adjusted for age, gender, refractive error, and intraocular pressure, an almost two-fold increased risk of NTG (P = .004, odds ratio 2.27, 95% confidence interval 1.30 to 3.97) was found with the OPA1 IVS 8 +32 C allele. Although there was no significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the HTG patients and control subjects (P = .24), the age at the time of diagnosis (53 +/- 11.0 years, median value +/- median absolute deviation) in the HTG patients with the OPA1 IVS 8 +32 C allele was significantly younger than that (57 +/- 12.0 years) in the HTG patients without C allele (P = .048). CONCLUSIONS: The OPA1 IVS 8 +32 T/C polymorphism is associated with NTG, and may be used as a marker for this disease association. This polymorphism also influences the phenotypic feature in patients with HTG and should be considered to be a genetic risk factor not only for NTG, but also for HTG.

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PubMed2006

Methylenetetrahydrofolate reductase gene polymorphisms c.677C/T and c.1298A/C are not associated with open angle glaucoma.

PURPOSE: To assess whether or not the c.677C/T and c.1298A/C genetic polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene are associated with open angle glaucoma (OAG). METHODS: Genomic DNA was examined in a cohort of 131 Japanese patients with normal tension glaucoma (NTG), 133 patients with primary open angle glaucoma (POAG), and 106 control subjects. The mean age at the time of blood sampling was 62.8+/-13.3 years (mean+/-SD) in the patients with NTG, 61.8+/-15.4 years in the patients with POAG, and 65.0+/-10.5 years in the control subjects. MTHFR c.677C/T and c.1298A/C genotype and allele frequencies were determined using pyrosequencing analysis, and the findings were compared between the OAG patients and control subjects. The frequencies of compound MTHFR c.677C/T and c.1298A/C genotypes were also compared between OAG patients and control subjects. RESULTS: No significant differences were observed (p>0.05, chi2 test or Fisher's exact test) regarding the MTHFR c.677C/T genotype (TT: 14.5%, CT: 44.3%, CC: 41.2% for patients with NTG; TT: 20.3%, CT: 41.4%, CC: 38.3% for patients with POAG; TT: 17.9%, CT: 36.8%, CC: 45.3% for control subjects) and c.1298A/C (CC: 0%, AC: 38.9%, AA: 61.1% for patients with NTG; CC: 2.3%, AC: 32.3%, AA: 65.4% for patients with POAG; CC: 0.9%, AC: 41.5%, AA: 57.6% for control subjects). There were no allele frequencies between the NTG or POAG patients and the control subjects. In addition, no significant differences (p>0.05, chi2 test) were found in the frequencies of the compound MTHFR c.677C/T and c.1298A/C genotypes between the NTG or POAG patients and the control subjects. CONCLUSIONS: The MTHFR c.677C/T and c.1298A/C polymorphisms were not found to be associated with NTG and POAG. Further studies in the different ethnic populations should be performed to elucidate the relationship between MTHFR and OAG.

Adenine↗

PubMed2005

The apolipoprotein E gene polymorphism is associated with open angle glaucoma in the Japanese population.

PURPOSE: To assess whether genetic polymorphisms of the apolipoprotein E (APOE) gene are associated with open angle glaucoma (OAG) in the Japanese population. METHODS: Genomic DNA was examined in a cohort of 310 Japanese patients with OAG and 179 control subjects. The average age was 63.5+/-14.4 years (mean+/-SD) for the OAG patients and 65.5+/-11.6 years for the control subjects. The presence or absence of OAG in patients and controls was based on clinical examination and/or ophthalmic records. The APOE allele frequency (epsilon2, epsilon3, and epsilon4 alleles) was studied by restriction fragment length polymorphism, and compared between OAG patients and control subjects. The association between the intraocular pressure (IOP) and the APOE alleles was also evaluated. RESULTS: There was a significant difference in the APOE genotype frequencies between these groups (p=0.0006 chi2 test). The frequencies of the epsilon2 and epsilon4 alleles were significantly lower in the OAG patients (epsilon2: 2.6%; epsilon4: 6.0%) compared to the control subjects (epsilon2: 5.0%, p=0.048; epsilon4: 10.6%, p=0.012; Fisher's exact test). The frequency of the epsilon3 allele was significantly higher in the OAG patients (91.4%) compared to the control subjects (84.4%, p=0.0010; Fisher's exact test). Adjusted for age, gender, and IOP, an appropriate three fold reduction in OAG risk (odds ratio [OR] 0.29, 95% confidence interval [CI] 0.10 to 0.80; p=0.018) was found with the epsilon2 allele and a two fold increased risk of OAG (OR 1.97, 95% CI 1.06 to 3.67; p=0.033) was found with the epsilon3 allele. The maximum IOP (18.3+/-6.0 mm Hg) in patients with the epsilon4 allele was significantly lower than that (21.3+/-9.1 mm Hg) in patients without the epsilon4 allele (p=0.006, Student's t-test). CONCLUSIONS: The APOE gene polymorphism is associated with OAG in the Japanese population. Further studies in the other ethnic populations should be performed to elucidate the relationship between APOE and OAG.

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PubMed2004

Mutations in the optineurin gene in Japanese patients with primary open-angle glaucoma and normal tension glaucoma.

The optineurin gene (OPTN) was identified as a gene that causes primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). To investigate the frequency of sequence changes in OPTN in Japanese glaucoma patients, single-strand conformation polymorphism analysis and subsequent sequence analysis were performed for genotyping OPTN in 165 unrelated Japanese patients with POAG and 148 patients with NTG, with 196 control subjects without glaucoma as reference subjects. Out of four mutations reported to be associated with risk and to cause disease in Caucasian patients, sequence alterations in 458G > A and 691_692insAG were not detected in any investigated Japanese patients with glaucoma, and alterations in 1944G > A and 603T > A, were present in similar frequencies in glaucoma patients and control subjects. The current results suggest that there may be certain racial differences between Japanese and Caucasians with respect to OPTN genotypes.

Adult↗

PubMed2004

Optic nerve damage in mice with a targeted type I collagen mutation.

PURPOSE: Transgenic (Col1a1(r/r)) mice gradually develop elevated intraocular pressure (IOP) with open angles. The present study was undertaken to evaluate optic nerve axonal loss with time in these mice. METHODS: The IOP of transgenic (Col1a1(r/r)) mice and control wild-type (Col1a1(+/+)) mice was measured at 7, 12, 16, 24, 36, and 54 weeks of age using a microneedle method. Transgenic Col1a1(r/r) and control Col1a1(+/+) mice at 24 and 54 weeks of age were randomly selected and their optic nerves were processed conventionally for electron microscopy. Optic nerve cross-sections were collected 300 micro m posterior to the globe. Low (200X) and high (10,000X) magnification images were collected systematically and were masked before analysis. For each nerve, cross-sectional area was measured in low magnification images, and axonal number was counted in high magnification images. RESULTS: Mean IOP of the transgenic Col1a1(r/r) mice was significantly higher than that of the control Col1a1(+/+) mice at 16, 24, 36, and 54 weeks by 21%, 42%, 41%, and 33% respectively (P < 0.05). The mean axonal density and total axonal number in the transgenic Col1a1(r/r) mice at 54 weeks of age (n = 10) was significantly less than those in the control Col1a1(+/+) mice at 24 weeks (n = 5) and 54 weeks (n = 5; P = 0.0081 and P = 0.020, respectively, analysis of variance, P < 0.05 for pair-wise comparisons). The mean axonal density and total axonal number in the transgenic Col1a1(r/r) mice at 54 weeks also were significantly less than in the transgenic Col1a1(r/r) mice at 24 weeks (n = 10). Mean axonal loss between 24 and 54 weeks of age in the transgenic Col1a1(r/r) mice was 28.7%. CONCLUSIONS: Transgenic Col1a1(r/r) mice develop sustained elevation of IOP and progressive optic nerve axon loss. This suggests that these mice may be useful as a mouse model of primary open angle glaucoma as well as for assessing the relationship between collagen type I metabolism and optic nerve axon loss.

Animals↗

PubMed2004

Regional optic nerve damage in experimental mouse glaucoma.

PURPOSE: To assess the relationship between regional variation of axon loss and optic nerve head anatomy in laser-induced experimental glaucoma in the mouse. METHODS: Experimental glaucoma was induced unilaterally in eight NIH Swiss black mice. Intraocular pressure (IOP) was measured for 12 weeks, and the mice were killed. The eyes were enucleated, and both optic nerves were dissected and processed conventionally for electron microscopy. Low- and high-magnification images of the optic nerve cross sections 300 microm posterior to the globe were collected systematically and masked before analysis. For each nerve, cross-sectional area was measured in low-magnification micrographs. Axon number and density were determined in the high-magnification micrographs. Loss of axonal density was compared between the superior and inferior and nasal and temporal areas of the optic nerve cross section. Additional cross-section micrographs were collected at 10- or 20-microm intervals throughout the optic nerve head. RESULTS: In the treated (glaucoma) eyes, mean IOP was 44% higher than that in the control eyes. The optic nerve cross-sectional area, mean axonal density, and total axonal number were significantly less than those in the control eyes (P < 0.01 for each). Axon loss in the superior optic nerve was greater than in the inferior optic nerve in each glaucomatous eye (P = 0.012). The ratio of axonal density in the superior and inferior optic nerve (superior-to-inferior [S/I] ratio) in all treated eyes was <1.0 and significantly lower than that in the control eyes (P = 0.012). The central retinal vessels occupied approximately 20% of the central optic nerve head cross-sectional area, gradually shifted position ventrally as they progressed toward the scleral foramen (the mouse does not have a lamina cribrosa), and exited the inferior retrobulbar optic nerve adjacent to the posterior of the globe. CONCLUSIONS: Ocular hypertension in the mouse eye sufficient to cause optic nerve damage induces preferential loss of superior optic nerve axons. Optic nerve axon loss appeared less among the axons that were near the major optic nerve blood vessels at the scleral foramen. Topographic differences in optic nerve axon loss should be considered when evaluating optic nerve damage in experimental laser-induced glaucoma in the mouse.

Animals↗

PubMed2003

The association between Japanese primary open-angle glaucoma and normal tension glaucoma patients and the optineurin gene.

Glaucoma represents one of the most common eye diseases and is characterized by progressive loss of visual fields. In the more advanced stages bilateral blindness may result, due to optic nerve atrophy and an excavated optic nerve head. Open-angle glaucoma is one of the main disease subsets, which may be further divided into high tension primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). Recently, the optineurin ( OPTN) gene was identified as a causative factor for NTG. Alterations in this gene were found in Caucasian families with NTG. In particular, c.458G>A, c.691-692insAG and c.1944G>A were shown to be risk factors. Since NTG is reported to be the most common form of glaucoma in Japan, and to identify if the OPTN gene plays a role in POAG, the DNAs from 148 unrelated Japanese patients with NTG, 165 patients with POAG and 196 unrelated controls who were not suffering glaucoma were investigated by appropriate genotyping techniques. No glaucoma-specific mutations were found in the OPTN gene in Japanese glaucoma patients. However, some novel single-nucleotide polymorphisms (SNPs) in the exons and introns are reported in this paper for the first time.

Adult↗

PubMed2003

Optic nerve damage in experimental mouse ocular hypertension.

PURPOSE: To evaluate optic nerve damage in mice after laser-induced ocular hypertension. METHODS: Ocular hypertension was induced unilaterally in 13 NIH Black Swiss mice by laser photocoagulation of the limbus. Over the following 12 weeks, intraocular pressure (IOP) was measured at regular intervals by the microneedle method. The optic nerves of these mice and of seven normal untreated mice were then processed conventionally for electron microscopy, and cross sections of the nerve 300 micro m posterior to the globe were collected. Low- and high-magnification images were collected systematically and masked before analysis. For each nerve, cross-sectional area was measured in low-magnification micrographs, and axon and glia numbers were counted in high-magnification micrographs. RESULTS: In normal untreated mice, the average number of axons was 59,597 +/- 3,112 (mean +/- SD). Variation among these measurements was 5.7% +/- 3.9%. After laser treatment, the duration of high IOP ranged from 2 to 12 weeks (6.2 +/- 3.6 weeks, mean +/- SD). The mean IOP in the treated eyes was 1.3 times greater than the mean IOP in the control eyes (P = 0.0012). The maximum IOP in the treated eyes was 1.6 times greater than that observed in the control eyes (P < 0.0001). The optic nerve cross-sectional area, mean axon density, and total number of axons in the treated eyes were significantly less than in the control eyes (28.5% +/- 23.4%, 57.8% +/- 37.8%, and 63.1% +/- 38.1%, respectively; P < 0.005 for each). The decrease in optic nerve cross-sectional area and the positive integral of elevated IOP and duration of IOP elevation correlated significantly with total axon loss (r(2) = 0.79, P < 0.0001 and r(2) = 0.36, P = 0.040, respectively). The number of astrocytes per cross section of optic nerve was significantly greater in the treated eyes than in the control eyes (P = 0.014). CONCLUSIONS: Laser-induced ocular hypertension in mouse eyes can induce optic nerve axon loss that correlates with the magnitude and duration of elevated IOP.

Animals↗

PubMedDate not supplied

Personality assessment based on the five-factor model of personality structure in patients with primary open-angle glaucoma.

PURPOSE: Several characteristic personality types have been reported for glaucoma patients in previous studies. However, none of the previous studies used a common structural theory of personality. In this study, we conducted a multicenter cross-sectional case-control study using the recently established five-factor model of personality structure. METHODS: Personality was evaluated using the Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI), which is a questionnaire specifically designed to test the five-factor model of personality: neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C). Eligible questionnaires were obtained from 196 patients with primary open-angle glaucoma (POAG) (99 men, 97 women) and 223 reference subjects with no ocular disease except cataract (87 men, 136 women). The mean score of each NEO-FFI factor for POAG patients was compared to the scores for the reference subjects. RESULTS: Compared with the reference subjects, the mean N score was significantly higher (P = 0.013), the mean scores for A and C were significantly lower (P = 0.007 and P = 0.001, respectively), and the mean E score tended to be lower (P = 0.055) in male POAG patients. The mean E score was significantly lower (P = 0.023) in female POAG patients. CONCLUSIONS: Characteristic personality traits were noted in POAG patients, and a more significant relationship was found between personality and glaucoma in men than in women.

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