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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 343 records · Page 19Linked to original sources
PubMed1992

Mathematical modeling of fetal splenic growth: use of the Rossavik growth model.

Growth of the fetal spleen has been monitored by measurements of the maximal length (SL), profile circumference (SC), and profile area (SA) of the spleen, from 20 weeks to 41 weeks, menstrual age. Growth curves for these parameters have been determined using a specially developed growth curve model [P = c(t)k + s (t)]. R2 values of 94.3%, 94.9%, and 96.3% were obtained for SL, SC, and SA, respectively. Variability analysis indicated some progressive increase in variability with menstrual age for these three parameters. Variability data were used with the growth curve models to determine standard curves for SL, SC, and SA. These standard curves provide a superior means for evaluating the normal splenic growth in the fetus and for identifying splenic abnormalities in utero.

Embryonic and Fetal Development↗
PubMed1992

Adult T-cell leukemia/lymphoma (lymphoma type) with remarkable gastric lesions: a case report.

We report a case of a 53-year-old woman with adult T-cell leukemia/lymphoma (ATL) (lymphoma type) with multiple gastric lesions, admitted to our hospital because of systemic lymphadenopathy and epigastralgia. Gastroscopy showed a variety of gastric lesions including thickened folds, ulcerations and polypoid lesions. Biopsy specimens obtained from the stomach and lymph nodes revealed diffuse infiltration of pleomorphic mononuclear cells and the integration of HTLV-1 proviral DNA. We demonstrated through the investigation of 30 previously reported cases of ATL that this is a rare case of the lymphoma type of ATL presenting remarkable gastric lesions.

Blotting, Southern↗
PubMed1992

Inhibitory effects of beta-alanine on the vagal efferent and afferent excitatory responses of the stomach to stimulation of vagal trunk in cats.

The effects of beta-alanine on the electrically evoked vagal efferent (hexamethonium-sensitive initial excitatory response) and afferent (hexamethonium-resistant delayed excitatory response) responses of the cat stomach were studied. beta-alanine (30 to 300 micrograms/kg, i.v.) dose-dependently inhibited both the efferent and afferent response. The IC50 values of beta-alanine on the efferent and afferent response were 296 +/- 65 micrograms/kg and 128 +/- 35 microgram/kg, respectively. Maximal inhibitory effects of beta-alanine (300 micrograms/kg, i.v.) appeared about 1 hr after the injection. Glycine and taurine (100 to 10,000 micrograms/kg) did not affect these responses. Treatment with hexamethonium (10 mg/kg, i.v.) prevented the efferent response, but augmented the afferent response. The treatment with hexamethonium abolished the inhibitory effect of beta-alanine on the afferent response. Both picrotoxin (100 and 500 micrograms/kg, i.v.) and bicuculline (2000 micrograms/kg, i.v.) antagonized the inhibitory effects of beta-alanine on the vagal efferent and afferent responses of the stomach. The present experiments clearly demonstrated that beta-alanine inhibited both the vagal efferent and afferent excitatory responses of stomach to electrical stimulation of vagal trunk in cats.

Animals↗
PubMed1992

A precedence effect in the perception of inter-aural cross correlation.

Does the precedence effect, well known in the field of sound localization or lateralization, also apply to other percepts based on binaural processing? We have compared, with one and the same experimental paradigm, a manifestation of the traditional precedence effect in lateralization with a possible similar effect in the perception of diffuseness or compactness of a sound image. With dichotic headphone stimulation, lateralization was controlled by the inter-aural time delay (IATD), and diffuseness/compactness by the inter-aural cross correlation (IACC). The experimental paradigm rests on the principle of estimating the over-all sensation of a 20-ms noise burst, which was subdivided in two parts, with the relevant dichotic information (IATD or IACC) in the leading part being opposite to that in the trailing part. When each part is 10 ms, it is found that the overall sensation is slightly dominated by the information in the leading part, both for lateralization and for compactness/diffuseness. This dominance of the leading part can be compensated by a certain decrease of its duration and/or amplitude relative to that of the trailing part. It is found that this quantitative measure for the 'strength' of the precedence effect for the present stimulus is essentially the same for IATD and IACC, suggesting that the precedence effect does not apply exclusively to sound localization or lateralization, but to at least one other percept based on binaural processing as well, namely the processing of inter-aural cross correlation.

Acoustic Stimulation↗
PubMed1992

Primary malignant lymphoma of the central nervous system by Ga-67 and TI-201 brain SPECT.

Two patients with primary lymphoma of the central nervous system underwent both Ga-67 and TI-201 brain SPECT. Ga-67 scans showed remarkable accumulation of radiotracer corresponding to tumors detected by CT and MRI. More avid uptake was noted on the Ga-67 scans than on the TI-201 scans. In one patient, the intense tracer uptake had disappeared in the Ga-67 study performed after irradiation with 50 Gy. We are convinced that Ga-67 SPECT is useful for detecting and following the progress of primary lymphoma of the central nervous system.

Aged↗
PubMed1992

Enhancing effects of fluorescein on beta-lactam rash. I: High incidence of cefclidin rashes in an ophthalmological volunteer trial.

Disseminated maculopapular eruptions were frequently observed in a volunteer trial of cefclidin's use in ophthalmological and neurological examinations (8/12; 67%) It appeared at 8-12 days (mean +/- SD, 9.6 +/- 1.1 days) from the initiation of the trial and subsided within 1-2 days (mean +/- SD, 1.8 +/- 0.4 days). Patch testing with cefclidin produced a +/- reaction in 1 of 8 cases, and the drug-induced lymphocyte stimulation test (DLST) elicited a positive response (SI: 2.8) in 1 of 8 and a weakly positive response (1.8 < or = SI < 2) in 2 of 8. From these findings, it seems likely that the eruptions may be partially mediated by delayed type hypersensitivity (DTH) reactions to cefclidin. No such eruption was observed in the phase II trial of cefclidin where only 2.8% of 1.122 volunteers developed the eruption. The volunteers were given both fluorescein and oxybuprocain in their eyes to measure ocular tension on days -1, 0, 1, 3, 5, 7, 9, 11, 13 and weeks 3, 5, 7 after the initiation of cefclidin. Fluorescein and/or oxybuprocain may affect cefclidin to induce these abnormal reactions in the volunteers.

Adult↗
PubMed1992

Circulating intercellular adhesion molecule-1 (ICAM-1) antigen in sera of patients with idiopathic pulmonary fibrosis.

Intercellular adhesion molecule-1 (ICAM-1), a member of immunoglobulin supergene family with a five-domain structure, is known to play an important role in inflammatory diseases. An ELISA was developed using two MoAbs against human ICAM-1 in order to detect the soluble shedding ICAM-1 antigen in sera. We measured levels of circulating ICAM-1 antigen in sera of patients with idiopathic pulmonary fibrosis (IPF), pulmonary sarcoidosis, hypersensitive pneumonitis, bacterial and mycoplasmal pneumonia, and inflammatory diseases of other organs. The results clearly demonstrated that IPF had significantly high levels of circulating ICAM-1 in sera as compared with other disorders or normal controls. Moreover, immunohistochemical analysis with MoAb against human ICAM-1 disclosed that in IPF, the expression of ICAM-1 was intensively enhanced on alveolar epithelial cells. These results suggest that ICAM-1 may contribute to the pathogenesis of IPF.

Adult↗
PubMed1992

Validity of electrode placement at Fpz to detect alpha wave.

The possibility on placing electrodes at Fpz-A2 instead of C3-A2 was investigated to obtain a more stable configuration avoiding obstruction by the hair. Our original system of alpha wave detection by a microcomputer was used, and a total of 22 all-night hypnograms of five healthy young students was recorded. Pearson's moment correlation coefficients of alpha wave % between the two positions were 0.780-0.948. Except for one subject, alpha wave % taken at Fpz-A2 tended to be 3-5% lower than that at C3-A2. The above analysis indicates that using EEG electrode position of Fpz-A2 is valid and useful as a stable electrode configuration for a long-time monitoring.

Adult↗
PubMed1992

Effects of neonatal asphyxia on the serotonin neuron system in the developing brain studied by immunohistochemistry.

The effects of neonatal asphyxia on the serotonin neuron system were examined using the immunoperoxidase method. Male mice, 2 days of age, were exposed to total asphyxia (100% CO2) for 30 min. Mice that spontaneously survived were perfused transcardially with a fixative at 15, 30 and 60 days of age. Quantitative immunohistochemical analysis at 60 days of age demonstrated a significant decrease in the numbers of serotonin-immunoreactive cell bodies in the nucleus raphe dorsalis, the nucleus raphe pontis, the subpyramidal region, the total raphe system and the whole brain, while no significant reduction in the number of serotonin-immunoreactive cell bodies was observed in the caudal raphe system. Presumably degenerative changes in serotonin-immunoreactive fibers were observed in various parts of the brain of mice subjected to total asphyxia at 15 days of age, and the numbers of degenerated fibers decreased in almost all parts of the brain, the exception being the caudal portion of the brainstem, at 30 and 60 days of age. These results suggested that neonatal asphyxia induced permanent changes in the serotonin neuron system, with regional differences.

Animals↗
PubMed1992

Effect of the continuity and sampling rate of polygraphy data on sleep stage by a computerized scoring system--a reliability study.

The percentage of each sleep stage determined by visual judgment was compared with computerized judgment using continuous and three intermittent sampling data. Comparison of stage agreements of four types of computerized judgments with visual judgment were also conducted. Hypnograms of six healthy young male students were recorded on each of five nights. Data of each subject were compiled individually, and the six data were analyzed. Agreement rate of the sleep stage by computerized judgment using continuous (method A), one-third (method B), one-ninth (method C), and one-fifteenth (method D) data with that of visual judgment were compared. The agreement rate of visual and computerized judgment using method A showed no difference from that between visual and computerized judgment using method B. There was a significant loss of agreement between visual and computerized judgment using method C or D compared with that between visual and computerized judgment using method A. Paired t-tests were conducted for each stage percentage against total sleep time of visual judgment and those of computerized judgments using method A, B, C, or D. There were no significant changes in any sleep stage percentages between visual judgment and computerized judgments using method A, B, C, or D. From sleep stage agreement and the degree of difference from visual judgment, the acceptable limitation of the sampling period was concluded to be one-third of continuous data.

Adult↗
PubMed1992

[Instantaneous changes in sleep stage due to the sound of a passing truck].

The instantaneous effect of the sound of a passing truck on sleep of five male students, 23 to 25 years of age, was assessed. The peak levels of noise were adjusted to 55, 60, and 65 dB (A) with intervals of 18 and 13 minutes, and a frequency of one per hour. Background noise in the experimental room was Leq 42 dB (A). The sleep stage of each epoch was visually judged based on the criteria of Rechtschaffen & Kales. Data for pre-exposure epochs of sleep stage 2 and rapid eye movement (REM) were collected and 18 epochs, including two under noise exposure, were evaluated. Three sets of polygraphic data were sampled as controls from 10 minutes after 65 dB (A) exposure to the next exposure. Compared with the control, the percentage of stage 2 to shallower stages (stage 1, waking, or movement time (MT)) was significantly increased by exposure to 55, 60, and 65 dB (A). The change lasted for one minute with exposure to 55 dB (A), and 2 to 3 minutes with 60 and 65 dB (A). A decrease in the percentage of stage 2 to deeper stages was observed at 2 to 4 minutes after exposure to 60 and 65 dB (A). The percentage of stage 2 to MT increased at 60 and 65 dB (A). The percentage of stage REM to other stages increased with the exposure to 60 or 65 dB (A) within 4 minutes. The threshold of instantaneous change of stage 2 to shallower stages due to the sound of a passing truck was at the peak level at less than 55 dB (A), and that of stage REM to other stages at 55 to 60 dB (A).

Adult↗
PubMed1992

Surgery of hepatic cysts in a cat.

A 2-year-old female Japanese domestic cat weighing 3.6 kg was presented due to marked abdominal distention and was diagnosed as hepatic cyst. The bile acid concentration of the hepatic cyst was as low as the serum bile acid concentration. The membrane of the cysts was excised from the edge of the compressed hepatic tissue and no other surgical manipulation was performed. This surgical procedure is simple and quick compared to hepatic lobectomy, however, it is necessary to evaluate the fluid of the cyst before performing this procedure.

Animals↗
PubMed1992

Effects of naloxone and naltrexone on receptive and proceptive behaviors in female rats.

The sexual receptive and proceptive behaviors induced by opiate antagonists, naloxone and naltrexone in estrogen-primed ovariectomized rats were observed under the presence of sexually active males. The females were treated intraperitoneally with naloxone or naltrexone at doses ranging from 0.5 to 4.0 mg/kg and the sexual behavior of females was tested before and after the injection of drug. The results obtained suggest that the opiate antagonists play a role in the regulation of lordosis behavior, but not proceptive behavior in female rats.

Animals↗
PubMed1992

[Improvement of pituitary homograft under the kidney capsule in mice].

The model of hyperprolactinemia induced by pituitary homografts under the kidney capsule has been used mainly in the field of reproductive physiology. The authors report an improved method for pituitary grafting in mice. The procedure was as follows: 1. The male pituitary glands with normal saline were aspirated into a polyethylene tube. 2. Two incisions were made in the kidney capsule. 3. The polyethylene tube with pituitary glands was inserted via a large incision. 4. Blowing air into the tube, the pituitary glands were left under the kidney capsule and normal saline streamed out of a small incision. Using this method, all pituitary grafted mice became pseudopregnant.

Animals↗