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Biomedical subjects

N Furuya

Publications and source records attributed to N Furuya.

At least 109 records · Page 6Linked to original sources
PubMed1991

Computer analysis of optokinetic pattern test for patients with localized lesions of unilateral frontal eye fields.

Four patients with localized lesions of the left frontal eye field as demonstrated at autopsy or MRI were studied. Their electronystagmography (ENG) recordings, which were induced by optokinetic stimulus, were analyzed by computer. Four factors were calculated by the ENG analyzing program. We conclude that the asymmetry of OKP in patients with localized lesions of the unilateral frontal eye fields is primarily caused by impaired S-VEL and F-VEL of the contralateral OKN compared with the side of the frontal eye field lesion.

Adult↗
PubMed1991

Slow and fast phase velocities of optokinetic nystagmus induced by the optokinetic pattern test in infratentorial lesions.

Optokinetic pattern (OKP) abnormalities in 36 patients with infratentorial lesions confirmed by CT or MRI were analyzed by microcomputer. The computer analysis system enabled the OKP data to be changed to digital data consisting of the slow phase velocity (S-VEL) and the fast phase velocity (F-VEL) in optikinetic nystagmus. In 16 patients with acoustic tumors. S-VELs were normal or borderline when the tumors were less than 2 cm in diameter, but when the tumors were more than 2 cm. S-VELs were severely impaired. F-VEL abnormalities were not seen in our study except in one patient. In 20 patients with brain stem and/or cerebellar lesions, S-VELs were abnormal in all the patients with the exception of 3. There was no significant difference in S-VEL between the group with brain stem lesions and that with cerebellar lesions. F-VEL abnormalities were seen in only 4 patients with brain stem lesions, especially pontine lesions. These findings suggest that S-VEL is a sensitive indicator for infratentorial lesions and F-VEL an important indicator for pontine lesions.

Adolescent↗
PubMed1991

Breathing patterns during sleep in stable asthmatic children.

Breathing patterns during sleep at night were studied in 15 asymptomatic asthmatic children and 11 nonasthmatic controls using impedance pneumography. Inspiratory time (TI), expiratory time (TE) and expiratory time/inspiratory time ratio (TE/TI) were used as the indices of breathing patterns. In the daytime, TI, TE and TE/TI, showed no significant differences between asthmatics and controls. During nocturnal sleep, TE and TE/TI increased significantly in the asthmatics compared with the value during daytime, while these values showed only a small variation overnight in the controls. TI showed no significant changes through the night in either the asthmatics and the controls. The results of this study indicate that the stable asthmatic children had abnormal breathing patterns during nocturnal sleep.

Adolescent↗
PubMed1991

[Application of fuzzy theory for optokinetic pattern test].

The optokinetic pattern test for optokinetic nystagmus is performed to diagnose equilibrium disorders on clinical examination. We constructed computer assisted instruction (CAI) algorithm based on knowledge of expert for optokinetic pattern (OKP) diagnosis theoretically based Fuzzy reasoning derived from Fuzzy theory to ascertain the possible application of CAI to OKP and to develop a useful diagnostic tool. The algorithm was constructed by rules of fuzzy reasoning using analysed data of diagnostic modes of one expert, consisting of six variables, and of 30 normal and 22 abnormal patterns of optokinetic nystagmus which were diagnosed by the expert. The results derived from the fuzzy reasoning and those obtained by expert agreed with 96% in this test battery. In addition, a consistency of 87.3% was obtained after comparison with another 251 OKP patterns which diagnosed by the same expert and estimated by this algorithm. This algorithm incorporating fuzzy theory is concluded to be useful in obtaining results of the same as those of an expert for diagnosing the equilibrium disorders. Furthermore, CAI using Fuzzy theory is confirmed to have good potential as a diagnostic tools.

Algorithms↗
PubMed1990

Frequency analysis of the first heart sound for patients on chronic hemodialysis.

According to Adolph et al., valuable information on the nature of myocardium can be obtained through frequency analysis of first heart sounds (S1) during the isometric contraction phase (ICP). We compared dominant frequencies (DF), which were defined as the frequency of maximum sound voltage, of S1 among 37 outpatients undergoing chronic hemodialysis (HD group) and 28 outpatients with neurosis (control group). Heart sounds, which were obtained at apex by a sound microphone and polygraph, were analyzed into frequency spectra by the maximum entropy method through a computer. Left ventricular dimensions and wall thickness were measured by echocardiography. Histories of hemodialysis ranged from 4 to 164 months, with an average of 54 months. Age and body weight of patients before each hemodialysis were comparable with control subjects. Although systolic blood pressure, left ventricular mass (LVM), and combined left ventricular mass (CLVM), which means LVM and the blood it contains, showed higher values in the HD group, the ratio of LVM and CLVM and ejection fraction were almost equal in both groups. Therefore, if elastic tissue of myocardium of HD patients is less, lower DF is expected. However, DFs were 22.6 +/- 7.8 Hz in the HD group and 22.6 +/- 9.6 Hz in the control group. It was concluded that (1) hypertension and overhydration were not primary causes of uremic cardiomyopathy, and (2) myocardium of HD patients received no significant damage if cardiac function remained intact, even through left ventricular hypertrophy and dilatation were induced.

Adult↗
PubMed1990

[Investigation on the etiology of sepsis by using experimental mouse model with leukocytopenia. 3. The role of Kupffer cells in the etiology of bacteremia].

In the previous report, we showed that the reticuloendothelial system (RES), especially the liver, played an important role in the etiology of bacteremia or sepsis as the major protective system. In this study, to investigate the role of Kupffer cells in the etiology of bacteremia, we isolated and cultured murine Kupffer cells using a technique involving perfusion with collagenase and DNase. We compared the adherence and phagocytosis rate of two groups of isolated bacteria from bacteremic mice by these cells. One group was bacteria causing systemic bacteremia consisted of P. aeruginosa and M. morganii, and the other was bacteria causing portal bacteremia consisted of E. coli, E. cloacae, K. pneumoniae and Enterococci. As a consequence, the following facts were revealed. 1. The bacterial phagocytosis and adherence rate by Kupffer cells were significantly higher in bacteria causing portal bacteremia than in bacteria causing systemic bacteremia. These data were correlated to each blood clearance rate from mice. 2. Blood clearance rate reflected mainly adherence of Kupffer cells to bacteria, and it was suggested that these adherence were one of the most important factor to protect the hosts from the advance of bacteremia from the portal to the systemic. 3. In the case of using peritoneal macrophage, we couldn't find the same correlation, so the possibility was suggested that the above phenomenon was specific to Kupffer cells.

Animals↗
PubMed1990

[Studies on defence effects of recombinant human granulocyte colony-stimulating factor (G-CSF) to infections. III. Protective effect on pulmonary and systemic infections of P. aeruginosa in neutropenic mice].

In the prior two reports, we demonstrated that G-CSF induced the polarization of neutrophils by itself, and also enhanced superoxide production from neutrophils stimulated by the chemotactic peptides. In this study, we have examined the protective effect of G-CSF in vivo on Pseudomonas pneumonia and septicemia in mice. Cyclophosphamide (CY) induced severe reduction of the number of peripheral leukocytes and weakened resistance for Psuedomonas aeruguinosa infection of mice. However, in mice receiving recombinant human G-CSF four daily subcutaneous injection, the number of leukocytes, particulary neutrophils, increased more rapidly than in controls receiving saline. Moreover G-CSF enhanced a protective effect to pulmonary and systemic pseudomonas infections. When G-CSF was administered together with antibiotics, significant synergism in the protection against pulmonary infection of Pseudomonas was observed. Carrageenan treatment decreased the protective effect of G-CSF. These results suggested that the protective effect of G-CSF against P. aeruginosa infection depends not only on PMN but also another complexed host defence mechanism.

Animals↗
PubMed1990

Breathing patterns in asthmatic children during attack.

Breathing patterns in asthmatic children during attack were studied using multielectrode impedance pneumography. A great number of respiration patterns were analyzed by a personal computer. During severe attacks, a pattern of prolonged expiratory time was noted. Inspiratory time, however, did not change, regardless of the severity of the asthmatic attack. No remarkable changes in breathing patterns were recognized during mild attacks. It was, therefore, considered that breathing patterns remained essentially unchanged except in cases of severe asthmatic attacks.

Adolescent↗
PubMed1989

[A case report of meningitis and sepsis due to Enterococcus faecium complicated with strongyloidiasis].

A 80 year-old male was transferred to our department on 18th Aug. 1988, for high fever and clouding of the consciousness. He had been treated with steroid hormone (betamethasone 3.0 mg/day for 15 days) for his uveitis. Enterococcus faecium was isolated from both blood and spinal fluid, and then Strongyloides sterocoralis was revealed both in the sputum and stool. Anti-Human T-cell leukemia virus 1 (HTLV-1) antibody was also positive serologically. At first, beta-lactam antibiotics were used for the treatment of purulent meningitis and sepsis, but after performing sensitivity tests for E. faecium, the antibiotics were changed to rifampicin (RFP), fosfomycin (FOM) and ofloxacin (OFLX) for their excellent activity against the organism. After the clinical symptoms, subsided, thiabendazole was used for disseminated strongyloidiasis in daily doses of 2,500 mg for six days initially. The drug was used three times with two week intervals. Both bacterial and parasite infections subsided and no recurrence has been noticed until now. This is the first case of meningitis caused by E. facium complicated with strongyloidiasis.

Aged↗
PubMed1989

Neurotransmitter effects on inhibitory burst neurons in the cat.

The present experiment was designed to determine which neurotransmitter influences the burst pattern in the firing of the inhibitory burst neurons (IBN) during vestibular nystagmus. Cats were anesthetized with ether and mounted in a stereotaxic apparatus on a turntable, implanted stimulation electrodes, removed occipital bone and aspirated the vermal part of cerebellum. After the operation ether was discontinued. The recordings took place with the cats in an alert condition created by upper cervical cord transsection, artificial respiration and local anesthesia by infiltrating 0.5% lidocaine into the semilunar ganglions every two hours. We also employed iontophoretic application of the various drugs: GABA, muscimol, glycine, serotonin (5-HT) and bicuculline through seven-barrelled glass micropipettes. GABA or muscimol did not influence nystagmus rhythm, but both chemicals caused strong suppression of burst activities in IBN. Since this inhibitory effect of GABA was suppressed by the simultaneous application of bicuculline, IBNs appear to be controlled by GABAA receptor. Glycine and 5-HT did not change the firing pattern of IBN. Application of bicuculline itself caused an increase of tonic discharges of IBN. These findings suggest that IBN receive inhibitory impulses from the higher GABAergic neurons.

Animals↗
PubMed1989

Analysis of optokinetic nystagmus in patients with localized lesions of unilateral visual cortices.

Optokinetic nystagmus (OKN) asymmetry in 4 patients with localized lesions of the unilateral visual cortices (2 in the right hemisphere and 2 in the left hemisphere), confirmed at autopsy or by CAT scan, was detected by computer analysis. The ENG recordings showed typical asymmetry of OKP: lower amplitude in the contralateral optokinetic pattern (OKP) than on the side with the visual cortex lesion. Analysis of this asymmetry revealed lower amplitude, remarkably impaired slow-phase velocity, and mildly impaired fast-phase velocity, with a slight difference in number of OKN. The findings suggested that asymmetry of OKP in patients with localized lesions of the unilateral visual cortices is primarily caused by the impaired slow-phase velocity of the contralateral OKN because of a slight change in number of OKN.

Adolescent↗
PubMed1989

[Aging and reference values of the parameters in optokinetic nystagmus].

Changes in optokinetic nystagmus by age were assessed, and preparation of reference values by age was made by the use of the data from 834 reference subjects. As a result, changes by age were observed at the test on optokinetic nystagmus. The reference values by these changes can be approximated with the quadratic and was considered, therefore, to be useful clinically. Four parameters were set for the test items for optokinetic nystagmus as the total number of nystagmus (NYS); the mean of eye velocity during the fast phase of nystagmus (FM); the algebraic summations of eye velocity (VEL) and amplitude (AMP) during the slow phase of nystagmus. As the process for statistical analysis, variables were divided into 7 groups, and after removing outlier (any extraneous data) in each group, changes in variables by age were assessed by the one-way analysis of variance and the method of multiple comparison (Ryan's method). As a result: 1) the age group of each variable seemed to develop into normal distribution; 2) it was presumed that change in NYS by age is less; 3-1) regarding FM, VEL and AMP, no change was observed in the variable by ages on 30s and 40s; and 3-2) however, decrease in the measured value was observed in ages on 60s along with aging. From these, the ages on 50s are the generation when the measured values of optokinetic nystagmus change. On the other hand, the reference values calculated, taking age into consideration, could be approximated with the quadratic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Latent defect in monocular optokinetic nystagmus after neonatal removal of the lateral suprasylvian area in the cat.

Three kittens underwent unilateral removal of the lateral suprasylvian area of cortex at the age of 1 month. After normal rearing for two years, their monocular optokinetic nystagmus was studied. During the experiment one eye was 'seeing' the optokinetic stimulus, but the other eye was 'covered'; by implanting scleral coils on both eyes, we measured movements not only in the 'seeing' eye, but also in the 'covered' eye. The stimulus was moved at a velocity between 1 and 40 degrees/s. Additionally, movements of the both eyes were simultaneously recorded in a normal cat. The previous results on movements of both eyes in normal cats which had been derived from the recordings by one coil (Vision Res., 26: 1311-1314, 1986) were confirmed by this experiment and were compared with the results of the lesioned cats. The gains (slow phase velocity/stimulus velocity) of the 'seeing' eye were not significantly different from the normal values. However, the gains of the 'covered' eye were significantly higher than the normal values when the stimulus was presented in the temporonasal direction, at the velocities between 1 and 40 degrees/s to the eye ipsilateral to the lesion and at the velocity of 40 degrees/s to the eye contralateral to the lesion; in the other conditions of stimulation the gains were not significantly different from the normal values.

Animals↗