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Biomedical subjects

N Osaka

Publications and source records attributed to N Osaka.

At least 37 records · Page 2Linked to original sources

Low calcium (1.25 mmol/L) dialysate can normalize relative hypoparathyroidism in CAPD patients with low bone turnover.

Recently, several reports have suggested that there is a higher incidence of low turnover bone in the absence of aluminium exposure in peritoneal dialysis patients than in hemodialysis patients. Relative hypoparathyroidism with mild hypercalcemia, induced by a positive calcium balance, is considered to be one of the major causes of this disorder. Thus, we recruited 9 continuous ambulatory peritoneal dialysis (CAPD) patients with relative hypoparathyroidism and low bone turnover [intact parathyroid hormone (iPTH) < 50 pg/mL, intact osteocalcin < 10.0 ng/mL] who had been prescribed 1.75 mmol/L calcium (Ca) dialysate for 5.0 +/- 0.3 years. They were then treated by low Ca (1.25 mmol/L) dialysate for nine months without vitamin D and aluminum administration. Intact PTH and bone metabolic markers [intact osteocalcin, alkaline phosphatase (ALP)] were measured every three months. Intact PTH levels increased from 21.1 +/- 3.8 to 159.2 +/- 32.8 pg/mL after the first three months; thereafter, those levels were maintained at around 150 pg/mL. On the other hand, intact osteocalcin levels rose consecutively from 6.7 +/- 1.2 to reach 22.0 +/- 3.8 ng/mL after nine months. Interestingly, the pattern of time course changes between PTH and intact osteocalcin was different. ALP activity did not change during the nine-month period. Corrected serum calcium was significantly decreased (p < 0.001) to approximately 0.25 mmol/L within one month, and the level remained almost the same thereafter. The serum phosphate level did not change without adjusting the original dose of calcium carbonate as a phosphate binder. We concluded that low Ca dialysate (1.25 mmol/L) is effective for the treatment of CAPD-related hypoparathyroidism with low bone turnover.

Aged↗

[Evaluation of nutritional status of patients on continuous ambulatory peritoneal dialysis (CAPD) by dual photon energy X-ray absorptiometry (DEXA)].

Malnutrition is a serious complication in patients on long-term CAPD treatment. Accordingly, quantitative evaluation of nutritional status is a critical issue. This study aimed to assess nutritional status by dual photon energy x-ray absorptiometry (DEXA) in CAPD patients. Total lean body mass (D-TBM), right arm lean mass (D-RAM) and body fat percent (D-% FAT) measured by DEXA were compared with mid-arm muscle circumference (MAMC) and body fat percent (AP-% FAT) measured by anthropometrics (AP) in 51 CAPD patients. The subjects were stratified into groups by gender, age, duration on CAPD, and diabetes mellitus or non-diabetes. There was significant correlation between D-TBM, D-RAM and MAMC (r = 0.519, p = 0.001, r = 0.545, p = 0.001) or D-% FAT and AP-% FAT (r = 0.763, p = 0.0001). However, in the groups of females with over 50 years and over 48 months of dialysis duration, there was no correlation between D-TBM, D-RAM and MAMC. The DEXA method is useful in the quantitative evaluation of nutritional status of dialysis patients serially.

Absorptiometry, Photon↗

Motion aftereffect with flickering test stimuli depends on adapting velocity.

Temporal tuning property of motion aftereffect (MAE) with flickering test stimuli (flicker MAE) was examined. Using sinusoidal gratings of several spatial frequencies (SF), MAE strength was measured for various adapting temporal frequencies (TF). Unlike the traditional MAE with static test field, the results indicated that flicker MAE did not depend on TF. Rather, when plotted as a function of velocity, the peaks had approximately the same adapting velocity of 5-8 deg/sec for all SF conditions tested, suggesting velocity dependence. This is further support of the idea that the two kinds of MAE are of different origin and suggests a higher origin of flicker MAE, perhaps in the area MT or MST.

Adaptation, Ocular↗

Difference of spatial frequency selectivity between static and flicker motion aftereffects.

The strength of motion aftereffect (MAE) was measured with the use of sinusoidal gratings of several spatial frequencies, to examine the spatial frequency selectivity of two types of MAE. With ordinary static grating as a test stimulus, to measure 'static MAE', the maximum aftereffect for each adapting spatial frequency was obtained at the testing stimuli of the same spatial frequency, showing spatial frequency selectivity. However, in the case when the sinusoidally flickering grating was used as a test stimulus, to measure 'flicker MAE', no spatial frequency selectivity was observed. The two types of MAE were considered to be based on different mechanisms. Static MAE is thought to depend on the spatiotemporal channel mechanism in the early processing stages, whereas flicker MAE might reflect higher-level processes which might occur at the extrastriate regions.

Fixation, Ocular↗

[Working memory capacity related to reading: measurement with the Japanese version of reading span test].

The efficiency of working memory capacity was measured with the Japanese reading span test (Japanese RST), which was developed based on the Carnegie-Mellon RST (Daneman & Carpenter, 1980). The correlation between the Japanese and the CMU RST was found to be highly significant. The present Japanese RST seems to predict reading efficiency in the same way as does the CMU RST. The Japanese RST was found to be correlated not only with memory span but with reading comprehension. However, it was not correlated with existing verbal intelligence tests.

Adult↗

Size of saccade and fixation duration of eye movements during reading: psychophysics of Japanese text processing.

The size of saccadic eye movements and eye fixations during Japanese text reading (written in both hirakana phonograms and kanji ideograms) were analyzed. Hirakana is sound based, i.e., it consists of symbols for syllables, but such text was processed differently from English text in terms of saccadic eye movements and fixations. In experiment 1 the reader was asked to read three types of text (hirakana only, kanji-hirakana mixed, and English) in a natural reading manner. The results show that kanji-hirakana-mixed text, which has picturelike symbols, requires shorter eye fixations and longer saccades than those required by hirakana text. The findings show that kanji and hirakana are processed differently. Logographlike kanji text greatly facilitated text processing and understanding during reading. In experiment 2 we found that kanji-based text had a wider perceptual span of reading than did hirakana text. The wider span is consistent with the longer saccade length for kanji-based text found in experiment 1. In experiment 3 we studied the convenient viewing position, i.e., the position within a word where the eye should fixate first for the isolated word to be recognized most quickly. A convenient viewing position was confirmed to exist both for hirakana- and kanji-based words, but for hirakana words the position changed as word length changed, as was expected from the results of experiment 2. In experiment 4 we measured lexical access time for hirakana- and kanji-based words and found that the reaction time to kanji-based words was faster than the reaction time to words written with hirakana.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Long-term prognosis of esophageal variceal cases treated with injection sclerotherapy.

One hundred fifty-two patients with esophageal varices underwent a total of 485 injection sclerotherapy procedures (mean, 3.2 times per each case). During 5 years of observation, 20 cases (13.2%) died following injection sclerotherapy. The 3-year survival rates, based on the Kaplan-Meier method, were 42% for emergency cases, 75% for elective cases and 90% for prophylactic cases. Significant differences (P less than 0.05) by the generalized Wilcoxon test were observed in the survival rates between emergency cases and prophylactic cases, and also between elective cases and prophylactic cases. Two cases (8.6%) of failure to control acute hemostasis were experienced. Twenty cases of bleeding after sclerotherapy were experienced, and 8 died of bleeding. The three-year bleeding rate according to the Kaplan-Meier method was 59% for emergency cases, 25% for elective cases and 7% for prophylactic cases. A significant difference (P less than 0.05) by the generalized Wilcoxon test was observed in the bleeding rate between elective cases and prophylactic cases. Non-bleeding rate (100%-bleeding rate) after sclerotherapy showed almost the same values as the survival rate. These results indicate that upper digestive tract hemorrhage influences the prognosis of patients after sclerotherapy.

Adult↗

[Studies on the position of the mandibular foramen].

Accurate investigation of the position of the mandibular foramen is important in anatomical and clinical studies, and there are a number of reports about such measurements. In this study, 140 Indian dry skulls, whose dental stages ranged from the stage before deciduous occlusion to the later phase of third molar eruption, were reproduced and the position of the mandibular foramen was measured using laser beams and three-direction photography. The position of the mandibular foramen was defined by the tip of the lingula mandibulae. 1. The angle of the lingula mandibulae was 45 degrees in children and it decreased with ageing. 2. At the later phase of the deciduous occlusion stage, the distance from the occlusal plane to the tip of the lingula mandibulae was high. 3. Each distance increased with the increasing age, height and width of the ramus mandibulae, the front and rear of the lingula mandibulae, and height of the lingula mandibulae. 4. There was little change with age in the ratio of the height of the ramus mandibulae to the height of the lingula mandibulae, and the ratio of the width of the ramus mandibulae to the distance of rear the lingula mandibulae. 5. The method for producing anesthesia in the mandibular foramen of children is as follows. The injection is aimed at the lingula mandibulae, which is 1/2 of the height and 1/2 of the width of the ramus mandibulae, from between the deciduous canine and the first molar on the opposite side, at a 10 angle to occlusal plane and at a 45 angle to the median line. In this manner it is possible to inject into the pterygomandibular space safely and expect certain anesthesia. In this study, the position of the mandibular foramen of children was accurately determined, as well as a safe clinical method for producing anesthesia to the mandibular foramen.

Child↗

Variation of saccadic suppression with target eccentricity.

Two LEDs separated by 24 degrees from each other were employed as saccadic fixation sources located on a circle about the centre of the saccade path. Either horizontal, vertical or oblique saccade paths were used and a brief test flash was presented at one of five retinal eccentricities during each saccade. The percentage of detected flashes was measured as a function of the location of the test stimulus and of its time delay with respect to the onset of the saccade. The results suggest that saccadic suppression is maximal at the fovea and is significantly decreased as retinal eccentricity increases.

Adolescent↗

Chromatographic separation and identification of naturally occurring chlorogenic acids by 1H nuclear magnetic resonance spectroscopy and mass spectrometry.

The high-performance liquid chromatographic separation and identification of the phenolic compounds in extracts from coffee bean are described. The system consists of Fine SIL C18-5 analytical and preparative columns and gradient elution (solvent A, 10 mM H3PO4; solvent B, methanol). The seven chlorogenic acids isolated were identified by mass spectrometry and nuclear magnetic resonance spectroscopy. The isolated and identified compounds are 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid and 3-O-feruloylquinic acid.

Chlorogenic Acid↗