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Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 109 records · Page 6Linked to original sources
PubMed1992

Seasonal change in the locomotor activity rhythm of the medaka, Oryzias latipes.

A group of the medaka, Oryzias latipes (Cyprinodontidae, orange-red variety, 25 males and 25 females), was kept in an aquarium, which was placed outdoors under natural conditions from December 1984 to January 1986. Locomotor activity at three layers (upper, middle, and lower layers) was recorded with a phototransistor system in each season. In summer, the fish showed typical diurnal activity at all three layers and the activity was greater than in other seasons. However, in autumn and winter, the fish became less active and showed relatively high activity at night at the upper or middle layer and diurnal activity at the lower layer. Nocturnal activity seemed to appear when the water temperature was decreased and the photoperiod was shortened. A free-running activity rhythm was also recorded under continuous darkness (DD) in each season; however, the fish showed clear free-running activity rhythms under DD only in summer.

Animals↗
PubMed1992

Preservation of quail blastoderm cells in liquid nitrogen.

1. Quail blastoderm cells isolated from the yolk were preserved in liquid nitrogen. 2. Frozen-thawed blastoderm cells of the quail were viable and survived in vitro. By injecting the frozen-thawed cells into chick embryos, quail-chick chimaeras were produced.

Animals↗
PubMed1992

Photoreceptor cell types in the retina of various vertebrate species: immunocytochemistry with antibodies against rhodopsin and iodopsin.

Types of photoreceptor cells in the retinas of 36 species of vertebrates (5 classes, 14 orders) were investigated immunocytochemically with monoclonal antibodies against chicken iodopsin (Io-mAb) and antiserum against bovine rhodopsin (Rh-As). In mammals, Rh-As labeled the outer segments of some photoreceptor cells in striped squirrels (a diurnal mammal) and those of most photoreceptor cells in mice (a nocturnal mammal), while Io-mAb labeled any photoreceptor cells in either of them. In all species of birds studied, Io-mAb labeled the principal and accessory members of double cones and single cones with a red oil droplet. Rh-As labeled single cones with a yellow or clear oil droplet in addition to rods. In turtles, both Rh-As and Io-mAb labeled single cones with a red or clear oil droplet and the principal (with a yellow oil droplet) and accessory members of double cones. This suggests that the visual pigments in these cones of turtles have common epitopes with bovine rhodopsin and chicken iodopsin. In Japanese grass lizards, single cones with a yellow oil droplet and double cones were immunoreactive to both Rh-As and Io-mAb. In snakes, rods and cones could not be distinguished but both positively and negatively stained cells were observed by the use of each antibody. In geckos, however, all photoreceptor cells were immunonegative to Io-mAb. In all species studied in amphibians, Rh-As labeled rods but not cones. Neither rods nor cones reacted with Io-mAb. In fishes, almost all species studied had well developed cones, and some of these cones were labeled by Rh-As. However, Io-mAb labeled the outer segments of some cones only in loaches. Rh-As labeled photoreceptor cells in all species of fishes studied. Thus, Rh-As recognized the outer segments of rods in all species studied from fishes to mammals, whereas the epitope recognized by Io-mAb is conserved in some species of fishes, most species of reptiles and all species of birds studied.

Animals↗
PubMed1992

[Quantitative evaluation of tongue atrophy on midsagittal magnetic resonance images (MRIs)].

This study was undertaken mainly to establish the quantitative parameter to evaluate the tongue atrophy on midsagittal MRIs and to show the clinical usefulness of such quantitative evaluation. Midsagittal MRIs of the tongue of consecutive 103 patients were analyzed. They were classified into 67 patients showing normal size (group without atrophy), 11 patients showing atrophy (group with atrophy) and 25 patients showing unsatisfactory MRIs with artefacts based on the routine evaluation. The patients in the group without atrophy did not show any pathologic processes to produce tongue atrophy on clinical findings. The area and perimeter of tongue and oral cavity, and the ratio of tongue area to oral cavity area and the ratio of tongue perimeter to oral cavity perimeter on midsagittal MRIs were obtained in each patient of groups with and without atrophy by using quantitative image analysis system. In the group without atrophy, regression analysis of the data on age was made and the 95% confidence interval of the data for age was obtained. No evidence that the tongue becomes atrophic with aging was obtained in the group without atrophy. Patients in the group with atrophy were best separated from those in the group without atrophy statistically when the ratio of tongue area to oral cavity area was regressed on age. Among 11 patients in the group with atrophy, 6 patients were not regarded as having tongue atrophy on clinical neurological examinations. Therefore, the evaluation of midsagittal MRIs is clinically useful.

Adolescent↗
PubMed1991

Effects of castration and testosterone treatment on the development and involution of the bursa of fabricius and the thymus in the Japanese quail.

We investigated the effects of castration on the development of lymphoid organs (bursa of Fabricius, thymus, and spleen) in the Japanese quail during 4-8 weeks of age under a long photoperiod (16L:8D) and the effect of testosterone implantation on the involution of the lymphoid organs under long (16L:8D) and short (8L:16D) photoperiods. Under 16L:8D, the bursa of Fabricius and thymus in intact quail grew rapidly and reached a peak at 6 weeks of age and regressed thereafter. In contrast, development of the lymphoid organs in castrated quail was well correlated with the body growth. Testosterone treatment induced a significant reduction in relative bursal weight to body weight at 6 weeks of age under 16L:8D and 8 weeks of age under 16L:8D and 8L:16D, in relative thymus weight at 6 weeks of age under 16L:8D and 8L:16D, and in relative spleen weight at 6 weeks of age under 8L:16D. Thus, we conclude that gonadal hormones play an important role in the development and involution of lymphoid organs.

Aging↗
PubMed1991

Production of quail-chick chimaeras by blastoderm cell transfer.

1. Quail-chick chimaeras were produced by injecting dissociated quail blastoderm cells into chick embryos. 2. Quail blastoderms were removed from the yolk and the cells were dispersed by trypsin treatment or pipetting. The cell suspension (1 to 5 microliters) was injected into the subgerminal cavity of unincubated chick embryos. The chick embryos were then cultured in recipient eggshells. 3. Quail blastoderm cells injected into the chick embryos adhered to the chick embryonic cells. The rates of hatching were 8.6% (38 chicks from 441 eggs) and 40.3% (48 chicks from 119 eggs) when the volumes of the cell suspension injected were 3 to 5 microliters and 1 microliter, respectively. 4. Seven out of 86 hatched birds were clearly identified as being chimaeric because part of the feather colouring was of quail specificity. In addition to these chimaeric birds, there were 8 chimaeric embryos which died before hatching. The distribution patterns of the quail feathers were varied among the chimaeric birds and embryos. 5. This technique provides a basis for the investigation of chick embryo cryopreservation, genetic transformation and analysis of cell lineage of chickens.

Animals↗
PubMed1991

Behavioral deficits induced by local injection of bicuculline and muscimol into the primate motor and premotor cortex.

1. The role of intracortical GABAergic inhibition in the performance of hand movements was studied in macaque monkeys while they performed two behavioral tasks: a raisin pick-up test and a visual reaction-time task. A gamma-aminobutyric acid (GABA) agonist, muscimol (MUS; 1-5 microgram), and an antagonist, bicuculline methiodide (BMI, 1-10 micrograms), were injected at various sites in the precentral motor cortex (MC), at which single-unit activity was related to the manual aspects of the performance of the reaction-time task. 2. Manual dexterity in the raisin pick-up task was severely disturbed by injections of either MUS or BMI into the hand MC. The effect was less severe after injections into the postarcuate premotor cortex (PM). 3. Performance of the reaction-time task was unstable after injection of BMI. The instability was caused by increased electromyogram (EMG) activity and by cocontractions of agonistic and antagonistic muscles of the arm during the pressing or release of the lever. 4. Reaction time was increased by injection of MUS, although the effect was temporary and decayed within 60 min. These deficits were consistent with the time course of the decrease in the total amount of EMG activity of hand muscles related to the task. As in the case of the raisin pick-up task, performance deficits were greater when MUS and BMI were injected into the hand MC and smaller when they were injected into the PM. 5. After injection of BMI, the animals gradually began to display muscle activity in response to a green warning signal that did not require a behavioral response. The muscle activity accelerated to spontaneous muscle twitches without any external stimulus, and the animals were unable to continue the task. These BMI-induced twitches were eliminated by injection of barbiturate. 6. Appropriate levels of GABAergic inhibition in the MC appear, therefore, to be important for the regulation of spatiotemporally organized ensembles of muscle activity, in particular for reciprocal contraction at the task-related joints.

Animals↗
PubMed1991

[A case of adult T cell leukemia/lymphoma with motor and sensory polyneuropathy].

A 62-year-old man was admitted to our hospital because of two months continuing paresthesia and muscle weakness of distal portions of the four limbs. On general physical examination, skin lesions, lymphadenopathy and hepatosplenomegaly were not found. Neurological examination revealed moderate weakness in the bilateral distal muscles of the lower limbs and left distal muscles of the upper limbs, and slight weakness in the right distal muscles of the upper limbs and the bilateral proximal muscles of the four limbs. Hand grasping powers were 24 kg and 2 kg on the right and left, respectively. The biceps, triceps and radial reflexes were decreased on the right, but normal on the left. The Achilles tendon reflex was decreased on the right and absent on the left. Paresthesia and superficial sensory disturbance were observed with glove and stocking distribution, which was more severe on the left side. The vibration and position senses were slightly decreased in the distal part of the lower limbs. On the laboratory examinations, serum anti-HTLV-I antibody was positive and no abnormal lymphocytes were observed in peripheral blood. Cerebrospinal fluid findings were normal, and anti-HTLV-I antibody was negative. Motor and sensory conduction velocities were normal or slightly decreased in all of the limb nerves examined, but the amplitudes of the compound muscle action potentials and the sensory nerve action potentials were asymmetrically decreased. Needle EMG showed fibrillation potentials and giant spikes with a reduction in number of motor unit potentials. The histological examination of the biopsied sural nerve revealed severe axonal degeneration without evidence of vasculitis or infiltration of abnormal lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4-CD8 Ratio↗
PubMed1991

[The respiratory function in children with collagen disease].

Respiratory function tests were performed on 60 children with collagen disease. Twenty-seven cases (45%) showed abnormalities in the respiratory function. These abnormalities were restrictive in 14 cases (52%), obstructive in 6 cases (22%), and mixed type in 7 cases (26%). Eight out of 14 SLE patients (57%) showed abnormalities of various types. Abnormalities were seen in 9 out of 25 JRA patients (36%) including 6 cases (67%) with restrictive type changes. Four out of 6 MCTD (67%) and 3 out of 9 DM (33%) patient showed functional abnormalities. Most of patients with these two types of collagen disease showed restrictive changes. Investigations performed by a research group of the Ministry of Health and Welfare showed the incidence of restrictive type changes (% VC less than 80) in adult patients of collagen disease to be in the following descending order: PM/DM greater than PSS greater than MCTD greater than SLE. Though small in number, our investigation revealed that a considerable proportion of MCTD and SLE patients showed restrictive changes in respiratory function. In evaluating the clinical course of the disease, it was thus considered to be important to follow up the progress of respiratory functions in children with collagen disease.

Adolescent↗
PubMed1991

A sporadic case of bulbospinal muscular atrophy of late onset.

We describe a 72-year-old male with bulbospinal muscular atrophy (BSMA) who was being treated for diabetes mellitus and congestive heart failure due to an old myocardial infarction. Although BSMA is a rare form of X-linked spinal and bulbar muscular atrophy of late onset, this case is a sporadic case. We emphasize the importance of recognizing a sporadic case of BSMA.

Age Factors↗
PubMed1991

Estimation of optically active methamphetamine and amphetamine using alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride.

A simple analytical method for determination of optically active amphetamine and methamphetamine using (+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride (MTPA-Cl) was developed. The method was found to be useful for determining the absolute configuration and optical purity. The results obtained using the capillary GC method agreed well with those of the NMR method. The absolute configuration for illegally used methamphetamine was the (S) form and its optical purity was greater than 99% enantiomeric excess. Racemic amphetamine was found to be resolved into optically active (S)-methamphetamine by barley roots.

Amphetamine↗
PubMed1990

1-Methyl-4-phenylpyridinium (MPP+) induces NADH-dependent superoxide formation and enhances NADH-dependent lipid peroxidation in bovine heart submitochondrial particles.

We studied the effects of 1-methyl-4-phenylpyridinium (MPP+), a metabolite of a parkinsonism-inducing drug, on the superoxide formation and the lipid peroxidation in bovine heart submitochondrial particles. The NADH-supported formation of superoxide radicals was induced by MPP+ at the concentration which is considered to exist in mitochondria of dopamine neurons. The formation increased as the NADH-ubiquinone reductase activity was inhibited by MPP+. The NADH-supported lipid peroxidation by the particles in the presence of ADP-Fe3+ chelate was also enhanced by MPP+ at similar concentrations. The formation was inhibited by succinate and the reduction of endogenous ubiquinone seems to be related to the inhibition. A possibility was discussed that the formation of superoxide anions and the lipid peroxidation may contribute in the cytotoxicity of the drug.

1-Methyl-4-phenylpyridinium↗
PubMed1990

Development in culture of the chick embryo from fertilized ovum to hatching.

An experiment was carried out to investigate whether thick albumen is essential for the normal development of the chick embryo. Fertilized ova recovered from the oviducts of hens were cultured in vitro and transferred to recipient eggshells with (method A) or without (method B) replacement of the thick albumen by thin albumen. Embryos from freshly laid eggs were transferred to recipient eggshells with (method C) or without (method E) replacement of the thick albumen by thin albumen or with replacement of the thick albumen by thin albumen diluted with solution of salts (method D). Embryos were then incubated until hatching. The rates of hatching of the cultured embryos were 34.4%, 16.2%, 50.0%, 6.9-26.7%, and 47.5% for methods A, B, C, D, and E, respectively. Thus the rate of hatching of cultured fertilized ova was increased by replacement of the thick albumen by thin albumen at the blastoderm stage. Chicks obtained by method A reached maturity and produced viable offspring, and this technique provides an improved method for the culture of fertilized ova to hatching.

Albumins↗
PubMed1990

Disinhibition in the monkey prefrontal cortex, by injecting bicuculline, induces forelimb movements learned in a GO/NO-GO task.

Local injection of a GABA (gamma-aminobutyric acid) antagonist, bicuculline, into Brodmann's area 8 (Walker's areas 8A and 45) of the monkey prefrontal cortex induced movements of the contralateral forelimb in 4 monkeys that were well-trained to perform a two-choice visual discrimination GO/NO-GO task by appropriate release of the hand from a lever. But the same procedures of injection in two naive monkeys did not. These results indicate that, during learning of the task, a new structure responsible for learned movement of the forelimb was made in area 8 and was disinhibited by bicuculline and, furthermore, they suggest that inhibitory GABA neurons suppress tonically efferent neurons associated with the initiation of movement.

Animals↗
PubMed1990

Duration of egg formation in hens selected for increased rate of lay under 23 h and 24 h light-dark cycles.

1. The intervals from oviposition to the next ovulation and the times spent by the ovum in various parts of the oviduct were examined, in hens selected for increased rate of lay over 5 generations under a 23 h light-dark cycle (23HS line) and kept in a 22 h light-dark cycle, and in hens selected under a 24 h light-dark cycle (24HS line) and kept in a 24 h light-dark environment. 2. The intervals from oviposition to the next ovulation were 13 min and 25 min in the 23HS and 24HS lines respectively. Times from ovulation to entry of the ovum into the uterus were 4 h 44 min and 4 h 43 min in the 23HS and 24HS lines respectively, and times spent by the ovum in the uterus were 19 h and 19 h 24 min in the 23HS and 24HS lines respectively. 3. It is concluded that the reduced oviposition interval in the 23HS line compared to the 24HS line was caused by the reduction in the interval from oviposition to the next ovulation and the time spent by the ovum in the uterus.

Animals↗