Total plasma homocysteine is not increased in Japanese patients with gout.
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Chromatography, High Pressure Liquid↗
Biomedical subjects
Tetsuya Yamamoto
Publications and source records attributed to Tetsuya Yamamoto.
A simple method of selecting gout patients for treatment with uricosuric agents, using spot urine and blood samples.
OBJECTIVE: To develop a simple means of selecting gout patients for treatment with uricosuric agents. METHODS: In 124 gout patients, spot urine and blood were sampled before breakfast and after overnight fast (except water) on the day of 24 h urine collection. Spot urine uric acid/creatinine ratio (Ua/Cr mmol/mmol) and serum creatinine x Ua/Cr (Scr*Ua/Cr micromol/l) were calculated together with 24 h urinary uric acid excretion/body surface (24 Ua/S). The patients were then classified either below or above 2.84 mmol/m2/day for 24 Ua/S. RESULTS: Classifications based on spot urine Ua/Cr (cut off value set at 0.34), spot urine Scr*Ua/Cr (cut off value set at 28.1), and a combination of spot urine Ua/Cr and Scr*Ua/Cr were found to be not significantly different in diagnostic accuracy for the detection of patients with 24 Ua/S below 2.84 mmol/m2 (77%, 81%, and 81%, respectively) and sensitivity (80%, 83%, and 76%, respectively). However, specificity by a combination of spot urine Ua/Cr, and spot urine Scr*Ua/Cr was higher than by spot urine Ua/Cr alone (91% vs 74%, P < 0.05), although the specificity was not significantly different between a combination and spot urine Scr*Ua/Cr alone (91% vs 78%) or between spot urine Ua/Cr and spot urine Scr*Ua/Cr (74% vs 78%). CONCLUSION: A combination of spot urine Ua/Cr and spot urine Scr*Ua/Cr may be clinically useful in selecting gout patients with 24 Ua/S below 2.84 mmol/m2 for treatment with uricosuric agents without adverse effects.
Adult↗
Superior segmental optic hypoplasia found in Tajimi Eye Health Care Project participants.
PURPOSE: To investigate the prevalence and characteristics of superior segmental optic hypoplasia in Japanese. METHODS: We studied 14 779 subjects, aged 40 years or older, who underwent IMAGEnet fundus photography as part of a large-scale eye disease screening project conducted in Tajimi, Japan. A single researcher reviewed all of the photographs for the presence of ocular abnormality in the optic nerve head and retina, paying special attention to the presence of superior segmental optic hypoplasia. RESULTS: Fundus photographs of 14 431 cases (28,396 eyes) were successfully reviewed. We found superior segmental optic hypoplasia in 37 cases (54 eyes; 0.3% of the cases and 0.2% of the eyes). Of the 37 cases, 23 (62%) showed the corresponding visual field defect in at least one eye. CONCLUSION: The prevalence of superior segmental optic hypoplasia is about 0.3% in the Japanese population.
Adult↗
Agreement between peripheral anterior chamber depth evaluation using the van Herick technique and angle width evaluation using the Shaffer system in Japanese.
PURPOSE: To examine the correlation between the van Herick system and the Shaffer system in a large-scale epidemiological survey conducted on healthy Japanese subjects. METHODS: The van Herick technique was performed on 14,779 subjects aged 40 years and over who participated in an ophthalmic epidemiological survey conducted in Tajimi City, Gifu Prefecture. Eyes classified as grade 1 or 2 according to the van Herick technique were diagnosed as narrow angle eyes, and those eyes were subjected to secondary examination using a gonioscope. In the secondary examination, glaucoma specialists evaluated angle width based on the Shaffer system. RESULTS: Nine hundred and twenty-three eyes of 505 subjects (108 men and 397 women) were determined to be narrow-angle eyes among the 14 779 subjects surveyed. There were 78 grade 1 eyes and 845 grade 2 eyes. Three hundred and eighty-three subjects (75.8%) underwent gonioscopic examination, and 426 eyes (65.9%) had an angle as narrow as or narrower than Shaffer grade 2. Among the 51 eyes evaluated as van Herick grade 1, 44 (86.3%) had an angle an narrow as or narrower than Shaffer grade 2, while among the 595 eyes evaluated as van Herick grade 2,382 (64.2%) had an angle as narrow as or narrower than Shaffer grade 2. CONCLUSIONS: The van Herick technique closely coincided with the Shaffer system and was found to have a potential for use as a simple method for evaluating narrow-angle eyes in Japanese.
Adult↗
Topographic characteristics of the optic nerve head measured with scanning laser tomography in normal Japanese subjects.
PURPOSE: Few studies have been performed regarding the topographic information obtained with the Heidelberg retina tomograph (HRT) in normal Japanese. In this study, we examined the factors influencing optic disc parameters and hemisphere symmetry obtained with the HRT in normal Japanese subjects. METHODS: Mean values and the standard deviation range for the main HRT parameters were evaluated in 223 eyes of 223 normal Japanese subjects. The influence of age, sex, and disc size on HRT topographic data was analyzed. The superior and inferior hemisphere topographic parameters were compared. RESULTS: Disc area showed a significant difference by sex (P = 0.0493). Rim volume (r = -0.208, P = 0.019), height variation contour (r = -0.275, P = 0.001), and mean retinal nerve fiber layer (RNFL) thickness (r = -0.366, P = 0.001) declined with age. All parameters except height variation contour and mean RNFL thickness showed a clinically significant correlation with disc size (-0.159 < r < 0.719, P < 0.01). Cup parameters in the superior hemisphere were significantly greater than those in the inferior hemisphere. In contrast, rim parameters in the superior hemisphere were significantly smaller than those in the inferior hemisphere. CONCLUSIONS: Some factors, namely, sex, age, and disc size, affected the optic disc parameters in the HRT measurements. Possible parameter asymmetry between the two hemispheres should be considered in normal eyes.
Adolescent↗
Correlation between individual differences in intraocular pressure reduction and outflow facility due to latanoprost in normal-tension glaucoma patients.
PURPOSE: The amount of intraocular pressure (IOP) reduction achieved by the use of latanoprost eyedrops varies among patients, and there are even nonresponders. This report examines whether there is any correlation between the amount of individual variability in IOP reduction and the uveoscleral outflow facility after latanoprost eyedrop instillation in normal-tension glaucoma patients. METHODS: Sixteen normal-tension glaucoma patients (mean age, 56.4 years) were enrolled in the study to investigate the relationship between the amount of IOP reduction and outflow facility. Before treatment, subjects underwent circadian IOP measurement and then tonography, and the outflow facility was calculated. Subsequently, patients began treatment once daily with latanoprost instillation in one eye. After 4 weeks of daily latanoprost treatment, circadian IOP was measured again. RESULTS: Mean pretreatment outflow facility was 0.23 +/- 0.05 microl/min per mmHg. On average, latanoprost instillation decreased IOP by 2.8 mmHg, but the reduction varied among individuals from -0.3 mmHg to 5.8 mmHg. No significant correlation was noted between the outflow facility and the IOP decline associated with latanoprost. CONCLUSION: Because there was no significant correlation between individual IOP reduction by latanoprost and outflow facility, the differences in substantial change in uveoscleral outflow after latanoprost administration may be one explanation for the individual variation in IOP reduction after treatment with this drug.
Adult↗
Diurnal variation of intraocular pressure in suspected normal-tension glaucoma.
PURPOSE: To assess diurnal variations of intraocular pressure (IOP) in suspected normal-tension glaucoma (NTG) patients with subsequent long-term observation to detect changes that may lead to a new diagnosis. METHODS: Diurnal variation of IOP was measured in a sitting position at 2-h intervals for 24 h in a total of 569 subjects with suspected NTG. RESULTS: Thirty of the 569 subjects (5.3%) showed IOP values exceeding 20 mmHg during the 24-h monitoring and were diagnosed as having primary open-angle glaucoma (POAG). In subjects in whom NTG was definitely diagnosed based on the results of the 24-h monitoring, the average maximum, minimum, and mean IOP was 16.1, 11.7, and 13.9 mmHg, respectively, and the mean diurnal variation in IOP was 4.4 mmHg. The peak time was observed outside clinic hours (1800-0800) in 41.4% of patients, and the trough time was observed during clinic hours (1000-1600) in 15.9%. In 2.9% of NTG subjects, the diagnosis was eventually changed to POAG during follow-up. CONCLUSION: Assessment of diurnal variations of IOP in suspected NTG patients is useful for the differential diagnosis of POAG from NTG and for establishment of a baseline, which may affect the management plan.
Adolescent↗
Ultrasound biomicroscopic classification of zonules in exfoliation syndrome.
PURPOSE: Exfoliation changes in the zonules or ciliary processes may be the earliest clinical sign of the exfoliation syndrome (XFS). In the present study we investigated the usefulness of ultrasound biomicroscopy (UBM) for detecting the early changes of XFS in zonules. METHODS: Both eyes of 11 patients with unilateral XFS and the unilateral eyes of 11 subjects without evidence of XFS were examined using UBM. The incidence of zonular changes was compared among the XFS-positive eyes of the patients, their contralateral XFS-negative eyes, and the healthy eyes of the subjects without XFS. RESULTS: Using UBM, we could successfully describe the zonules in all UBM images of all subjects. In the four quadrants, the incidence of granular-type zonules was statistically different among the three groups: it was higher in XFP-positive eyes than in XFS-negative eyes, and it was higher in XFS-negative eyes than in healthy eyes. CONCLUSIONS: UBM can detect the zonular changes that may occur early in XFS. A granular-type change in the zonules may be the most typical finding in the presence of exfoliation material. Diagnostic criteria are proposed for the early detection of XFS, based on the changes found in the zonules by UBM.
Aged↗
Neuroprotective effects of R(-)-1-(benzo[b]thiophen-5-yl)-2- [2-(N,N-diethylamino)ethoxy]ethanol hydrochloride (T-588) against retinal ganglion cell death induced by elevated intraocular pressure in rat.
PURPOSE: We investigated whether T-588 can attenuate retinal ganglion cell (RGC) death induced by elevated intraocular pressure (IOP). METHODS: IOP elevation was induced unilaterally by argon laser irradiation of the rat trabecular meshwork 4 days after an intracameral injection of India ink. We orally administered either the vehicle, or 10, 30, or 100 mg/kg body weight (BW) of T-588 24 hours before the laser application. Five days after the laser application, 1.5 microL of 3% Fast Blue was injected into the superior colliculi bilaterally. Three days after the Fast Blue injection, the eye was enucleated and the retinal whole flatmount was prepared. Labeled ganglion cells were counted by fluorescence microscope with an ultraviolet filter. RESULTS: Laser treatment significantly increased the IOP. The percentages of labeled RGCs in the lasered eyes as compared with the nonlasered contralateral eyes were 78.0 +/- 11.6% in the control group, 78.7 +/- 12.9% in the 10 mg/kg BW group, 79.1 +/- 13.0% in the 30 mg/kg BW group, and 91.0 +/- 9.0% in the 100 mg/kg BW T-588-treated group. The survival rate of RGCs was significantly higher in the 100 mg/kg BW T-588-treated group than in the control group. CONCLUSION: T-588 appears to have a neuroprotective effect on retinal ganglion cells in this ocular hypertensive model.
Administration, Oral↗
Quantification of retinal nerve fiber defects in glaucoma: three-dimensional analysis by Heidelberg retina tomograph.
PURPOSE: To describe a new method of quantifying retinal nerve fiber layer defects (NFLD) in glaucomatous eyes using the Heidelberg Retina Tomograph (HRT). METHODS: Mean tomographic images including the optic disc and peripapillary area were constructed using HRT. An image field of 15 degrees x 15 degrees or 20 degrees x 20 degrees was used for the NFLD analysis. Data on the nerve fiber layer thickness was collected and further analyzed circumferentially across the NFLD at a position 500 microm away from the optic disc margin. We studied 31 patients with early to moderate open-angle glaucoma, ie, with visual field defects appearing earlier than stage 3 of the modified Aulhorn-Greve classification. We determined the width (W), maximum depth (D), and cross-sectional area of the NFLD (A), and we identified correlations between these parameters and the visual field indices from Humphrey Visual Field tests, mean deviation (MD) and corrected pattern standard deviation (CPSD). RESULTS: NFLD parameters could be obtained from 20 of 31 eyes (65%). There was a statistically significant correlation between the D and A parameters, and between these parameters and the maximum depression threshold in the corresponding visual field. No significant correlation was found between the NFLD parameters, the global visual field indices (MD, CPSD) and the mean value of the total deviation (TD) in the corresponding hemifield visual field. CONCLUSIONS: A cross-sectional NFLD image can be obtained using HRT. Among the three NFLD parameters, maximum depth (D), and area under the surface (A) correlated well with the visual field threshold.
Diagnostic Techniques, Ophthalmological↗
In vivo gadolinium neutron capture therapy using a potentially effective compound (Gd-BOPTA).
BACKGROUND: In a previous study, we found that Gadobenate dimeglumine (Gd-BOPTA) resulted in a significantly greater Gd uptake by brain tumor tissue than Gadopentate dimeglumine (Gd-DTPA). Therefore, we investigated whether Gd-BOPTA is an efficient agent for neutron capture therapy (NCT). MATERIALS AND METHODS: Four groups of Fisher344 rats (control, neutron (n), n+ Gd-DTPA, n+ Gd-BOPTA) were subcutaneously injected 9L gliosarcoma cells in both hind legs. Gd-BOPTA and Gd-DTPA (0.05 mmol/g tumor weight) were injected directly into the tumor. At the peak of Gd uptake, thermal neutron irradiation was applied. RESULTS: Two Gd+ groups showed pronounced tumor growth delay as compared with the control and neutron groups (p = 0.0053, 0.0064, respectively). Furthermore, the BOPTA group showed significantly prolonged delay of tumor growth as compared to the DTPA group (p = 0.033). CONCLUSION: This is the first report of Gd-NCT to demonstrate that Gd-BOPTA serve as an effective compound for NCT. Better cytocidal effects of Gd-BOPTA warrant further investigation of subcellular Gd distribution.
Animals↗
Prediction of boron concentrations in blood from patients on boron neutron capture therapy.
BACKGROUND: In boron neutron capture therapy, blood boron concentration is the key factor to calculate radiation dose, however, blood sampling is difficult during neutron irradiation. MATERIALS AND METHODS: The prediction of blood boron concentrations for BNCT treatment planning has been prospectively investigated using patient data obtained at first craniotomy after the infusion of a low dose of sodium undecahydroclosododecaborate. RESULTS: The boron biodistribution data showed a biexponential pharmacokinetic profile. If the final boron concentration at 6 or 9 hours after the end of the infusion is within the 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%. CONCLUSION: Actual boron concentrations during BNCT were reasonably and accurately predictable from the test data.
Adult↗
Protective effects of EGCG on salivary gland cells treated with gamma-radiation or cis-platinum(II)diammine dichloride.
Dysfunction of salivary glands is often associated with aging and cancer therapy. Green tea polyphenols were previously found to protect normal epithelial cells from reactive oxygen species, and to induce apoptosis in tumor cells. The current study investigated whether -(-) epigallocatechin-3-gallate (EGCG), the major green tea polyphenol, protects normal salivary gland cells from the effects of gamma-irradiation and the chemotherapy drug cis-platinum(II)diammine dichloride (CDDP). Human immortalized salivary acinar and ductal cells, and oral squamous cell carcinoma cells were irradiated with gamma-rays or treated with CDDP, with or without pretreatment with EGCG, followed by MTT and BrdU incorporation assays. The results demonstrated that EGCG protected the normal salivary gland cells from chemical or irradiation-induced damage. However, protection of oral cancer cells by EGCG was also observed if EGCG was at physiologically achievable salivary concentrations but not at higher concentrations, suggesting that the combination of green tea consumption with cancer therapy requires further evaluation.
Carcinoma, Squamous Cell↗