Search PubMed⌕ Search

Biomedical subjects

T Usui

Publications and source records attributed to T Usui.

At least 289 records · Page 16Linked to original sources
PubMed1993

Contrast sensitivity for the stationary and drifting vertical stripe patterns in patients with optic nerve disorders.

Subjective contrast sensitivity for the stationary and horizontally drifting vertical stripe patterns was measured in normal subjects and in patients with glaucoma, optic neuritis and optic atrophy. Contrast sensitivity was also determined objectively using an eye movement reflex (optokinetic nystagmus) recorded by means of electro-oculography. The contrast sensitivity for the drifting stripe patterns in normal subjects was characterized by a depression of sensitivity at the high spatial frequency and an increased contrast sensitivity at the low spatial frequency in comparison with the results of stationary stripe patterns. The measurement of contrast sensitivity for the horizontally drifting vertical stripe patterns was found to be more sensitive for detection of minor damage to the optic nerve than that for the stationary patterns. The results of the subjective contrast sensitivity and the objective one determined using an eye movement reflex showed a good correlation.

Adolescent↗
PubMed1993

Effects of soft X-ray irradiation on ocular development in Sprague-Dawley rats.

Pregnant rats were irradiated with soft x-rays at a dose of 1.6, 3.2, 6.3 or 12.6 Gy on Day 9 of gestation, and the eyes of F1 offspring were examined using indirect ophthalmoscopy and biomicroscopy during Postnatal Week 5. Ophthalmoscopic examination revealed iris and choroidal coloboma, microphthalmia and anophthalmia in the 3.2, 6.3 and 12.6 Gy groups. In addition to those anomalies, lens luxation and associated anterior displacement of the vitreous face, and retinal vascular anomalies were observed in the 12.6 Gy group. Histological examination revealed agenesis of retinal vessels. Ophthalmoscopic examination using biomicroscopy and indirect ophthalmoscopy detected choroidal coloboma, lens and vitreous luxation and defect in retinal vessels which could not be detected by external observation, demonstrating the usefulness of this technique in the postnatal stage of teratology studies.

Animals↗
PubMed1993

Spontaneous development of anti-collagen type II antibodies with NTA, and anti-DNA antibodies in senescence-accelerated mice.

We previously reported that circulating natural thymocytotoxic autoantibody (NTA) and IgG-anti-DNA antibodies were the major serological characteristics of a substrain of SAM, SAM-P/1. We present here a study of ageing in which we further measured and compared various kinds of circulating IgG antibodies including anti-collagen type II, rheumatoid factor (RF), and anti-2,4,-dinitrophenol (DNP), between SAM-P/1 and control SAM-R/1 mice. The results showed that age-associated increases in anti-collagen type II antibodies in SAM-P/1 were distinctively higher than those in SAM-R/1 when the mice were over 4 months of age, and the increases were significantly correlated with increases in NTA, anti-DNA antibodies, RF activities and anti-DNP antibodies. Anti-collagen type II antibody activity was not significantly inhibited by preincubating the antibodies with DNA, IgG-Fc and DNP-BSA samples. These findings suggest that antibodies specifically directed against collagen type II can be produced in a background of polyclonal B cell activation, and that these antibodies in association with NTA and anti-DNA antibodies may play a pathogenic role in the development of accelerated senescence in SAM-P/1 mice.

Aging↗
PubMed1993

[An analysis of prognostic factors in patients with prostatic cancer after hormone therapy and radiotherapy].

To investigate prognostic factors for prostatic cancer, 110 patients who had received hormonal treatment (HT) and 43 patients who had received radiotherapy (RT) were studied. Age of the patients ranged from 49 to 92 years old (median 71 years old) and follow-up period ranged from 3 to 164 months (median 50 months). Survival rate was calculated by Kaplan-Meier method with statistical analysis based upon Cox's proportional hazards regression model. This analysis identified performance status as the most important factor for al patients, followed by histological grade for patients HAVING received HT, and lymph node metastasis for patients received having RT. The result suggests that routine clinical data provide a good indicator as to the prognosis of prostatic cancer.

Aged↗
PubMed1993

Amphotericin B-induced resistance to Pseudomonas aeruginosa infection in mice.

We evaluated the effects of amphotericin B (AmB) against Pseudomonas aeruginosa (P. aeruginosa) infection in mice. Pretreatment with 2 mg/kg of AmB 24 hours before infection significantly increased the survival rates of mice intraperitoneally infected with either P. aeruginosa or Escherichia coli. To evaluate the mechanism of this AmB-induced resistance to infection, we conducted a number of experiments. Peritoneal macrophages exposed in vitro to AmB showed superior bactericidal activity compared to that of control macrophages. Interleukin-1 production by peritoneal macrophages from mice pretreated with 2 mg/kg of AmB was significantly higher than that in control mice. Serum tumor necrosis factor level after intravenous injection of P. aeruginosa was also higher in mice pretreated with 2 mg/kg of AmB than in control mice. These data indicate that AmB induces resistance to P. aeruginosa in mice. Furthermore AmB-induced activation of peritoneal macrophages and their production of interleukin-1 and tumor necrosis factor appeared to play important roles in this phenomenon.

Amphotericin B↗
PubMed1993

[Control survey data analysis with smoothed distribution curve].

Assay data and normal range collected in quality control surveys were analyzed with a smoothed distribution curve, in order to perform appropriate analysis of the data. In the control survey, the committee set a relative allowable limit for each test. A variable was changed continuously through the data range, and the data within the allowable limit were counted. In the computer program, the variable was changed step wise in logarithmic scale. These data were plotted on a graph with log-scale on X-axis and per cent of relative data in Y-axis. The graph thus obtained shows smoother curve than the histogram of the data, and Y-axis scale shows actual data within the allowable data at the variable scale. Normal ranges and assay data of several chemistry assays were analyzed with this method. Distribution of normal range of enzyme assays showed plural peaks in each test. Especially, in choline esterase assay, more than ten different units were used in laboratories in Japan with the same unit name, IU/1. In, amylase assay, nevertheless the normal range was separated in three peaks, the data of sample assay did not separate in peaks correspond to the normal range peaks. Thus, the smoothed distributions curve is useful for data analysis in quality control survey.

Amylases↗
PubMed1993

Spinal epidural involvement in pleural lymphomas developing from long-standing tuberculous pyothorax or pleuritis.

Spinal epidural involvement was noted in 3 patients with pleural lymphoma developing from long-standing pyothorax or pleuritis. Two patients presented with cord compression syndrome and pleural tumor. The other patient showed rapidly progressive signs of cord compression 8 months after the diagnosis of pleural lymphoma. Biopsy and autopsy findings revealed that both the epidural masses and the pleural tumors had the pathological features of malignant lymphoma. Several reports have described pleural lymphomas complicated with chronic tuberculous pyothorax. However, as far as we know, there is no previous report associating spinal epidural compression with pyothorax-related pleural lymphoma. Spinal involvement should be included as a noteworthy complication of pleural lymphoma developing from long-standing tuberculous pyothorax.

Empyema, Tuberculous↗
PubMed1993

Interaction of testosterone-oestradiol binding globulin (TeBG) and albumin with human prostatic carcinoma in vitro.

During a period of incubation, the accumulation of testosterone-oestradiol binding globulin (TeBG) and albumin were noted in the cells of human prostatic carcinoma in vitro. These accumulations were inhibited by addition of rabbit anti-human TeBG antibody. However, the accumulation of human chorionic gonadotropin was not prominent. These observations suggest that TeBG and albumin are incorporated into the cells of human prostatic carcinoma.

Antibodies, Neoplasm↗
PubMed1993

Spontaneous cure of acute bronchitis caused by Chlamydia pneumoniae in a 15-year-old boy.

Chlamydia pneumoniae was isolated from the pharyngeal swab of a 15-year-old patient with acute bronchitis. The serum IgM antibody against C.pneumoniae was elevated up to 160-fold in the acute phase and decreased to 20-fold in the convalescent phase using the microimmunofluorescence (MIF) test. IgG antibody titers in the acute phase and the convalescent phase were 40-fold and 160-fold respectively using the MIF test. The patient recovered from the bronchitis without any effective treatment, indicating spontaneous cure of the disease.

Acute Disease↗
PubMed1993

[Fluorescein angiographic findings regarding the optic disc in cases of low-tension glaucoma and the chronic stage of anterior ischemic optic neuropathy].

The optic disc was studied by stereofluorescein angiography in 7 cases of the chronic stage of anterior ischemic optic neuropathy (AION) and 20 cases of low-tension glaucoma (LTG), to clarify the difference in vasculature. In the LTG patients, a selective and well-defined decrease of laminar and prelaminar capillaries in the upper and (or) lower temporal area of the optic disc was found in 38 (95%) of 40 eyes in the 20 cases. In the AION patients, a decrease of laminar and prelaminar capillaries was also found in 3 (43%) of 7 eyes in the 7 unilateral cases, but the specific area and form of vascular reduction were not found. These results show that the angiographic picture of the optic disc in LTG is clearly different from that in AION.

Adult↗
PubMed1993

Electroretinogram and visual evoked potential in two siblings with adult form galactosialidosis.

We recorded flash electroretinograms (ERGs), flash visual evoked potentials (VEPs), pattern ERGs and pattern VEPs in two siblings with adult form galactosialidosis. The amplitude of b-wave was decreased in flash ERGs. The peak latency of flash VEPs was within normal range. The pattern ERGs and VEPs were nonrecordable. These results suggested the damage of retinal ganglion cell and inner nuclear layer in these cases.

Adult↗
PubMed1993

Spatial modulation transfer function of vision by pattern visual-evoked potentials in patients with early glaucoma.

We applied subjective and psychophysical methods and pattern visual-evoked potential (VEP) P100peak latency as an objective index to measure spatial modulation transfer function (MTF) in normal subjects and patients with early primary open-angle glaucoma (POAG) in an effort to detect impairment of the spatial MTF of vision. To estimate spatial MTF objectively, the peak latency of the P100 component of pattern VEP was investigated. The mean contrast sensitivity in normal subjects derived from the pattern VEP peak latency was found to be maximum at the check size of 14.4 minutes of arc (i.e., 2.08 cycles per degree of spatial frequency), and the objective spatial MTF curve coincided well with that of the subjective one at all spatial frequencies examined. A statistically significant positive correlation was found between the objective (VEP) contrast threshold and the subjective one. Deterioration of the objective contrast sensitivity derived from the VEP peak latency was found to be much prominent that of the subjective one in patients with early glaucoma.

Adolescent↗
PubMed1993

[An approach to evaluation methods for laboratory work].

Evaluation methods were proposed for quality control, normal range calculation and laboratory diagnosis. As a quality control method, the Xbar-R control chart should be evaluated with an error detection chart or with operating characteristic functions. Normal range calculation was evaluated by three parameters, accuracy, precision and robustness which represents stability against abnormal data contamination. Prior to evaluating the laboratory diagnosis, patient data were plotted on a three dimensional chart, a star map, to determine whether apparent clusters were formed. Laboratory diagnosis is a process of reduction of multivariate medical information, and it develops new parameters related to the pathological state of the patient. The method was evaluated using entropy calculation or average count of abnormal parameters.

Clinical Laboratory Techniques↗
PubMed1993

[Prognostic factors in patients with hepatocellular carcinoma treated by transcatheter arterial embolization (TAE)--significance of repetitive therapies and responses to them within 6 months after the first intervention].

We retrospectively analyzed the prognostic factors associated with survival in HCC patients (113 cases, male 95, female 18, mean age 62.1 +/- 8.2yr.) treated only by TAE. Univariate analysis revealed that following factors significantly correlated with survival, such as T.Bil, tumor type, Vp factor, the response to the first TAE and the best response to TAE attained within 6 months after the first therapy. Also, multivariate analysis proved that T.Bil, ICGR15' and the best response to TAE during the initial 6 months were significant. Even if the first response to TAE was "no-change (NC)", the cumulative survival rate of patients would be improved when the responses to the second or the third therapy became "partial response (PR)" within 6 months after the first one. There were no significant differences between patients with which the best response to TAE within the initial 6 months were PR and those with NC in clinical backgrounds, dose of anti-cancer drugs, and dose of lipiodol used in the therapies. However, the mean interval between the first and the second TAE performed within 6 months 70 days. These results implied the importance of getting "PR" state no later than 6 months after the first intervention for the long survival in HCC patients. To accomplish this, repetitive treatments between short periods were recommended.

Adult↗
PubMed1993

Pro-opiomelanocortin messenger RNA levels in anterior pituitaries of female Wistar fatty rats.

We have studied pro-opiomelanocortin (POMC) gene expression by quantifying the POMC mRNA contents in anterior pituitaries of female Wistar fatty rats, a strain obtained by transfer of the fa gene in Zucker rat to Wistar Kyoto rat, in an attempt to understand the role of ACTH synthesis in altered ACTH and corticosterone secretion in these rats. Five- and 12-week-old female Wistar fatty rats and their lean littermates were examined. Plasma ACTH levels were significantly higher in fatty rats than in lean rats (5 weeks: 114.5 +/- 17.5 pg/ml vs. 54.3 +/- 12.4 pg/ml; 12 weeks: 83.8 +/- 12.3 pg/ml vs. 51.7 +/- 6.8 pg/ml; P < 0.01). There was no significant difference between 5-week-old fatty rats and lean rats in POMC mRNA contents nor in POMC/beta-actin ratios in anterior pituitaries. Twelve-week-old fatty rats, however, had significantly higher POMC mRNA contents and also higher POMC/beta-actin ratios in anterior pituitaries than those in lean littermates (P < 0.01, approximately three-fold difference between lean and obese rats). These data suggest that the difference in POMC mRNA contents between lean and obese rats becomes apparent as they grow and develop obesity and the elevated POMC mRNA levels are at least partly responsible for the increased ACTH secretion in 12-week-old fatty rats.

Adrenocorticotropic Hormone↗