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Biomedical subjects

A Okada

Publications and source records attributed to A Okada.

At least 271 records · Page 15Linked to original sources
PubMed1994

[Responses of electroencephalogram to different odors].

The responses of electroencephalogram (EEG) to different odors and their densities were studied on four men and two women at rest while sitting. The odors examined were citrus, floral and lavender, and their densities were 100 ppb and 200 ppb. The odors were released for ten minutes from a duct to fill the room completely. The subjective estimation indicated that citrus had a tendency to be the most comfortable odor in this study, but it was not significant. To evaluate changes of EEG, the power spectra of frequency-fluctuation of alpha wave (Fz) and the rate of alpha, beta, and beta/alpha wave (Oz, Fz) were calculated. The rate of alpha wave (Oz) in the period of giving out the citrus at 100 ppb was significantly (p < 0.05) higher than that of the lavender. The rate of beta wave (Oz) in the period of giving out the floral at 200 ppb was significantly (p < 0.05) higher than that of the lavender. The regression coefficient of the power spectra of frequency-fluctuation of alpha wave in the period of giving out the lavender at 100 ppb was significantly higher than those in the other periods of the experiment. The regression coefficient of the power spectra of frequency-fluctuation of alpha wave for lavender given out at 200 ppb was significantly (p < 0.01) higher than those for the other odors given out. It seems that the regression coefficient of the power spectra of frequency-fluctuation of alpha wave can be used for the evaluation of psychophysiological responses.

Adult↗
PubMed1994

Anthropometrical data of middle-aged Japanese women for industrial design applications.

Despite the growing importance of human interface design, and despite the growing number of working women, no considerations have been given to women's working spaces and tools. Their designs are based on men's anthropometrical data, and this does not assure safety and amenity of women's working environments. Moreover, few data on women's body measurements are available. The Research Institute of Human Engineering for Quality Life is carrying out an ergonomic anthropometrical study on a large number of Japanese people to create a database for industrial use. The fee for the use of these data is, however, making it very difficult to profit from their acquisition. Therefore, we conducted an anthropometrical study for industrial design use on middle-aged female subjects, who are in the most difficult age group to access. This report should be useful in designing working spaces and tools for women as laborers as well as users.

Adult↗
PubMed1994

[Property and clinical availability of the noncontact autofocus specular microscope].

Reproducibility of results and possible clinical use of a newly developed noncontact autofocus specular microscope were studied. Morphological parameters of corneal endothelium were analyzed on images taken with the noncontact autofocus specular microscope and the ordinary contact specular microscope simultaneously in 10 eyes of 10 normal subjects. Intraphotographic and interphotographic study by autoanalysis of 5 images each of 10 eyes taken by the noncontact instrument showed small coefficient variation of mean cell area and cell density (less than 5%, individually). These morphological parameters showed about 7% difference between autoanalysis and manual analysis of the images taken by the noncontact instrument. In comparison with the images taken by the contact instrument, the images taken by the noncontact instrument showed about 7% difference in mean cell area and cell density (p < 0.001, individually). In respect of reproducibility, this newly developed noncontact autofocus specular microscope is clinically useful. The differences of morphological parameters between the new and ordinary instruments might be caused the differences in corneal shapes.

Adult↗
PubMed1994

A study of the complications induced by conventional and disposable contact lenses.

We reviewed the charts of 23,068 patients (45,580 eyes) who were prescribed contact lenses in order to investigate the incidence of corneal complications in Japan. This population of patients included wearers of various types of conventional contact lenses as well as disposable extended wear lenses and daily disposable lenses. The rate of corneal complications and 95% confidence interval for each lens group were: polymethylmethacrylate (PMMA) lenses, 15.8% (358 of 2,267 eyes, 14.3-17.3%); rigid gas permeable lenses, 10.5% (3,191 of 30,459 eyes, 10.2-10.8%); acrylelastomer lenses, 7.2% (nine of 124 eyes, 2.7-11.7%); HEMA lenses 8.5% (534 of 6,261 eyes, 7.8-9.2%); high water content lenses, 4.0% (103 of 2,591 eyes, 3.6-4.4%); weekly disposable lenses, 4.9% (146 of 2,985 eyes, 4.1-5.7%); and daily disposable lenses, 2.5% (22 of 893 eyes, 1.5-3.5%). PMMA lenses had a significantly higher rate of corneal complications compared with other lenses, whereas the daily disposable lens had a significantly lower rate for the same. The majority of corneal complications for all types of lenses consisted of superficial punctate keratopathy, and there were no cases of corneal ulcers.

Adolescent↗
PubMed1993

Lack of N regions in antigen receptor variable region genes of TdT-deficient lymphocytes.

During the assembly of immunoglobulin and T cell receptor variable region genes from variable (V), diversity (D), and joining (J) segments, the germline-encoded repertoire is further diversified by processes that include the template-independent addition of nucleotides (N regions) at gene segment junctions. Terminal deoxynucleotidyl transferase (TdT)-deficient lymphocytes had no N regions in their variable region genes, which shows that TdT is responsible for N region addition. In addition, certain variable region genes appeared at increased frequency in TdT-deficient thymocytes, which indicates that N region addition also influences repertoire development by alleviating sequence-specific constraints imposed on the joining of particular V, D, and J segments.

Animals↗
PubMed1993

Spontaneous cortical granule release and alteration of zona pellucida properties during and after meiotic maturation of mouse oocytes.

Exocytosis of cortical granules (CGs) and the concomitant electron density changes of the zona pellucida (ZP) in the absence of sperm penetration were investigated in mouse oocytes processed with tannic acid containing fixation at various stages during and after maturation. After fusion of the CG membrane with the plasma membrane, the CG contents became very electron-dense, due to tannic acid. CG material is seen to be made up of coarse granular structures which gradually change to fine amorphous structures, which accumulate within the developing perivitelline space (PVS). When the coarse CG material attaches to the ZP, small domains exhibiting higher electron density appeared, and the number of these domains gradually increased. Release of CG was observed from metaphase I through metaphase II. In metaphase I to immediately after ovulation, the higher electron density of ZP and CG release was restricted to the cortical area overlying the meiotic spindle. Finally, the CG-free domain formed itself overlying the meiotic spindle as a result of CG release. However, in oviductal ova, CG release additionally occurred in the hemisphere opposite the spindle. At this stage the entire PVS was well developed and contained numerous fine electron-dense materials. Moreover, the inner half of the ZP increased in electron density as well. This change in electron density of the ZP might be associated with released CG material. These results suggest that the "partial cortical reaction" may play an important role in conditioning the ZP prior to ZP reaction.

Animals↗
PubMed1993

Studies on production of anticollagen antibodies in silicosis.

Silicosis is characterized by pulmonary fibrotic changes which consist primarily of an increase in collagen. In this study, anticollagen antibodies in the serum of 134 silicosis patients versus 40 normal subjects were examined and their relationship with immunoglobulin, autoantibodies, and procollagen III peptide (PIIIP) was investigated by enzyme-linked immunosorbent assay (ELISA). The mean levels of anti-human type I collagen (HI) and anti-human type III collagen (HIII) antibodies were significantly higher in the silicosis patients versus the normal subjects (P < 0.001). However, no differences were observed in the mean levels of anti-human type IV collagen (HIV) antibodies in the silicosis patients versus the normal subjects. Anticollagen antibodies in the sera of silicosis patients appear to be formed at an early stage of the disease. We observed a correlation between anticollagen antibodies and immunoglobulin. There was a tendency toward high values of anticollagen antibodies in the sera of patients positive for antinuclear antibodies (ANA) and rheumatoid factor (RF), both of which are autoantibodies. However, no correlation was observed between serum PIIIP and anticollagen antibodies. These observations suggest that, in silicosis, there is a relationship between anticollagen antibodies and immunoglobulins, as well as between anticollagen antibodies and autoantibodies. Measurement of anticollagen antibodies in the sera of silicosis patients offers a useful index for evaluating the prognosis of pulmonary fibrosis and autoimmune abnormality in silicosis.

Aged↗
PubMed1993

Vitamin A status in biliary atresia: intestinal absorption and liver storage of retinol.

The vitamin A status of 19 patients with corrected biliary atresia was examined. They had been receiving 5,000 IU of oral vitamin A daily postoperatively. Plasma vitamin A levels in the nonjaundiced group were almost within normal range, whereas those in the jaundiced group were significantly low compared with the controls. In the oral vitamin A tolerance test, plasma vitamin A levels increased from 33.1 +/- 11.8 to 215.4 +/- 100.7 micrograms/dL in the nonjaundiced group, and from 23.1 +/- 10.3 to 209.8 +/- 154.2 micrograms/dL in the slightly jaundiced group, at 4 hours after the administration of vitamin A, showing no difference between both group and control. In the severely jaundiced group, plasma vitamin A levels increased from 13.5 +/- 3.5 to 30.0 +/- 14.6 micrograms/dL, a significantly smaller increase compared with controls. However, liver vitamin A levels were greater than 20 micrograms/g liver in all patients, irrespective of the presence of jaundice. This study suggested that nutritional support to facilitate the synthesis of retinol-binding protein may be an important factor in addition to vitamin A supplementation.

Administration, Oral↗
PubMed1993

Anterior sagittal anorectoplasty as a redo operation for imperforate anus.

Based on the idea of transsphincteric approach by Peña, we applied anterior sagittal anorectoplasty (ASARP) as a redo operation in 10 patients, who present moderate to severe fecal incontinence postoperatively. Those patients exhibited anal opening located anteriorly to the center of contraction of external sphincter muscles. Operation is begun with making a circumferential skin incision in the mucocutaneous junction around the anal opening, extending posteriorly along the median line to the center of the external sphincter muscles. Upon confirming the vertical muscle and the external sphincter muscles, the rectal tube, being dissected free, is mobilized backward to be placed at the center of the vertical muscles and enclosed by the muscle. After the operation, an improvement was noted in either clinical symptoms or scores, being particularly marked for incontinence and staining scores. Anorectal manometry and barium enema studies also showed a significant improvement. These results provide ample justification of ASARP as a redo operation for imperforate anus being worthwhile trying in properly selected patients with poor anorectal function following the primary operation.

Anus, Imperforate↗
PubMed1993

Morphometric development of the human auditory system: ventral cochlear nucleus.

The development of the human cochlear nucleus was studied in serial sections of the brain of 12 fetuses at 12-40 weeks of gestation, an infant at 2 months of age and an adult of 63 years using an electronic planimeter with a computer. Morphometric analysis of the development of the ventral cochlear nucleus showed that its development accelerates after 18 weeks of gestation in terms of columnar volume, columnar length, neuronal number and neuronal size.

Auditory Pathways↗
PubMed1993

Clinical effect of WEB 1881 (nebracetam fumarate) on patients with dementia of the Alzheimer type and study of its clinical pharmacology.

We administrated WEB 1881, 800 mg/day (400 mg twice a day), nine patients with dementia of the Alzheimer type for 8 weeks, and undertook an open study to investigate the clinical effects of the distribution into the cerebrospinal fluid (CSF) as well as the influence on the neurotransmitter-related substances in the CSF. These were outpatients living at home with caregivers. Significant clinical improvement was shown by means of the Gottfries, Bråne, and Steen Scale and by Hasegawa's dementia scale. Unchanged WEB 1881 was identified in the CSF. The mean concentration of which was 198.7 ng/ml, this corresponded to 19.0% of the plasma concentration. Of several neurotransmitter-related substances measured in the CSF, a marked rise of AChE activity was observed. Adverse effects consisted of a slight skin eruption in one case and alterations in a clinical laboratory test in another case. These were, however, not significant from a clinical viewpoint. It is suggested that the mechanisms of action of WEB 1881 are based on its transit into the CSF as well as the activation of intracerebral acetylcholinergic systems.

Aged↗
PubMed1993

Indocyanine green test is a reliable indicator of postoperative liver function in biliary atresia.

In order to evaluate liver function in postoperative biliary atresia (BA) patients, the indocyanine green (ICG) clearance test was performed. Nineteen patients, ranging in age from 2 to 9 years, were classified into three groups. Group I were those who had no jaundice throughout the postoperative period (n = 9), Group II were those who had recurrent or intermittent jaundice (n = 7), and Group III were those who had persistent jaundice after hepatic portojejunostomy (n = 3). Forty-four volunteers of comparative age and sex served as controls to establish a normal range of ICG-K values in infants and children. The normal minimal ICG-K value in those 2-9 years of age was defined as 0.19. ICG-K values in BA patients were 0.262 +/- 0.073 (Group I), 0.150 +/- 0.060 (Group II), and 0.054 +/- 0.011 (Group III). All nine patients with ICG-K below the normal level had esophageal varices, and seven of nine had a history of gastrointestinal hemorrhage. Two patients with ICG-K values within the normal range had esophageal varices, and none had a history of gastrointestinal hemorrhage. Five of nine patients with ICG-K values below normal had low serum albumin levels, and all had low prealbumin levels. Of those with ICG-K within the normal range, none had low serum albumin or prealbumin levels. On the other hand, serum bilirubin and other liver function tests did not accurately reflect clinical findings. In conclusion, the ICG test using the ICG-K value was confirmed to be a reliable indicator of postoperative liver function in BA patients.

Biliary Atresia↗
PubMed1993

Age-related changes in proteoglycans of human ligamentum flavum.

Age-related changes in proteoglycans of human ligamentum flavum were studied using specimens obtained from patients divided into four age groups. The proteoglycans were purified by ion-exchange and gel-filtration chromatography. A low-molecular-weight proteoglycan with the same molecular size was present in all each age groups. Conversely, high-molecular-weight proteoglycan increased with advancing age. Properties of the sugar chains, glycosaminoglycans, in these proteoglycans were studied using cellulose acetate membrane electrophoresis and chondroitinase digestion. It was found that the high-molecular-weight proteoglycan consisted mainly of chondroitin 6-sulfate, whereas the low-molecular-weight proteoglycan consisted mainly of dermatan sulfate, although the ratio of chondroitin 6-sulfate increased with age. These results indicate that proteoglycans of human ligamentum flavum show changes in amount and composition with age.

Adolescent↗