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Biomedical subjects

K Otani

Publications and source records attributed to K Otani.

At least 217 records · Page 12Linked to original sources
PubMed1989

[Cockayne syndrome: siblings with different ultraviolet sensitivity and early onset of manifestations].

Siblings of Cockayne syndrome were reported. Both of them had characteristic manifestation of Cockayne syndrome. A 4-year-old boy had been noted to have irritability and nystagmus from the 6th day of his life, and his elder sister, 8 years old, had been diagnosed as cerebral palsy at the age of 6 months. The elder sister lacked photosensitivity clinically. The proband was more severely affected than his elder sister on both cerebral CT-scan and electrophysiological studies. Reduced colony forming ability after ultraviolet exposure is currently considered to be the primary abnormality in Cockayne syndrome. The cells originating from the boy had moderately reduced colony forming ability after ultraviolet irradiation, whereas the cells from his elder sister showed mildly reduced colony forming ability. There may be some relationship between the severity of the symptoms and the colony forming ability. There is a broad spectrum of clinical manifestations in Cockayne syndrome. Further investigations are necessary to clarify the relationship between the cytological abnormalities of Cockayne syndrome and its neurological manifestations.

Child↗
PubMed1988

Physiological and morphological characteristics of cat masticatory motoneurons--intracellular injection of HRP.

The physiology and morphology of masticatory motoneurons of adult cats were examined by the methods of intracellular recording and intracellular injection of horseradish peroxidase. Masseter and jaw-opening motoneurons were identified by intracellular recordings of the antidromic response following stimulation of the masseter and mylohyoid nerves, respectively. An excitatory postsynaptic potential (EPSP) was recorded from masseter neurons by stimulation of the masseter nerve with stimulus intensity below threshold for antidromic response. In contrast, the EPSP was not recorded from jaw-opening motoneurons by stimulation of the mylohyoid nerve with stimulus intensity below threshold for antidromic response. Patterns of postsynaptic potentials (PSPs) in the masseter motoneurons following stimulation of the tooth pulp or periodontal afferents were classified into 4 types: hyperpolarization (n = 40), depolarization-hyperpolarization (n = 9), hyperpolarization-depolarization (n = 5), and depolarization with spike potentials (n = 10). On the other hand, patterns of the PSPs in the jaw-opening motoneurons following stimulation of the same afferents were classified into two types: depolarization with spike potentials (n = 19), and hyperpolarization (n = 5). Twenty-five masseter and 7 jaw-opening motoneurons and an intranuclear neuron were reconstructed from serial sections in the transverse plane. On the basis of dendritic morphology, the masseter motoneurons could be classified into two major groups, type I (n = 15) and type II (n = 9), whereas two neurons were found to constitute a separate category of the masseter motoneuron. The dendritic distributions of all the jaw-opening motoneurons examined were generally similar and there was no indication of the existence of subtypes, whereas there were 2 or 3 subgroups in type I and type II masseter motoneurons. Type I masseter neurons had primary dendrites which extended radially in all directions, and the whole profile of their dendritic trees presented a spherical and an egg-shaped appearance. In type II masseter neurons, the origin of primary dendrites was bipolar or tripolar, and the whole profile of their dendritic trees presented a hemispherical and mirror-imaged, funnel-shaped appearance. The other two masseter motoneurons had a particular dendritic tree which was much simpler in configuration, with less tapering or branching than those of other neurons examined. In contrast, the dendritic profiles of all the jaw-opening motoneurons were similarly organized and showed vertically oriented dendritic trees which were more developed in the dorsomedial than in the ventrolateral direction.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1988

Little or no induction of hyperglycemia by 2-deoxy-D-glucose in hereditary blind microphthalmic rats.

Studies were made on whether hereditary microphthalmic rats (1), which are congenitally blind, showed a hyperglycemic response to intracerebroventricular injection of 2-deoxy-D-glucose (2DG) in their subjective light period. In contrast to previous findings in normal rats in which 2DG injection caused light-cycle dependent hyperglycemia (2) and bilateral lesion of the suprachiasmatic nucleus (SCN) completely abolished this hyperglycemia (3), 2DG injection caused no and only slight hyperglycemia in male and female rats with hereditary microphthalmia, respectively. Gross and histological examinations indicated that these rats had no optic nerve or retinohypothalamic tract and that their SCN had an abnormal structure. Locomotive activity recordings showed that all the blind rats had a free-running circadian activity rhythm. These findings suggest that the projection sites of the retinohypothalamic tract to the SCN are involved in the mechanism of the hyperglycemic response to 2DG, but that neural cells, which may be responsible for the generation of circadian rhythms, are not. We have reported that when adult rats were blinded by orbital enucleation, their hyperglycemic response to 2DG was suppressed temporarily 3-5 weeks after the operation, but that their plasma insulin level was basically higher and increased further after 2DG injection during this period (4). In congenitally blind rats, however, the basal plasma insulin level was not higher and the level did not change after 2DG treatment. This difference is discussed from the view point of the role of the premature SCN in regulation of the plasma insulin concentration.

Animals↗
PubMed1988

Synthesis and in vitro activity of various derivatives of a novel thromboxane receptor antagonist, (+/-)-(5Z)-7-[3-endo-[(phenylsulfonyl)amino]bicyclo[2.2.1] hept-2-exo-yl]heptenoic acid.

Several sulfonyl derivatives (13a-t) of (+/-)-(5Z)-7-(3-endo-aminobicyclo[2.2.1]hept-2-exo-yl)heptenoic acid (VI) were synthesized via its methyl ester 10. Sulfonylation of 10 with 11a-t followed by saponification yielded 13a-t. Inhibitory concentrations (IC50) of the corresponding sodium salts 14a-t for platelet aggregation were measured with rat washed platelets (WP) and rabbit platelet-rich plasma (PRP). IC50 values of some derivatives for contraction of the rat aorta were also measured. The IC50 values for rat WP increased from 2.9 to 26 nM in the order of 14a, 14c, 14d, and 14b for derivatives with an arylsulfonyl residue, depending on the number of of intervening methylene groups. Methyl derivative 14e exhibited a higher IC50 value than n-hexyl derivative 14f. Substitution with a p-methyl, p-fluoro-, or p-chloro group in 14a retained or slightly reduced its IC50 value, while a p-n-pentyl or p-oxycarbonyl group augmented it significantly. The representative 14a suppressed (15S)-15-hydroxy-11,9-(epoxymethano)prosta-5(Z),13(E)-dienoic acid (U-46619) induced aggregation of human WP with an IC50 value of 7.7 nM, which corresponds well to the IC50 value of 3 nM obtained for each displacement by 14a of [3H]-U-46619 or (5Z,15 xi)-9 alpha, 11 alpha-(dimethylmethano)-15-hydroxy-16-(3-[125I]iodo- 4-hydroxyphenyl)-17,18,19,20-tetranor-13-aza-11a-carbathrombo-5-en oic acid [( 125I]-PTA-OH) bound to human WP. Synthesis of thromboxane A2 (TxA2) in human WP stimulated by thrombin was not inhibited by 14a at a concentration up to 10 microM. From these observations, the corresponding acid 13a (S-145) was concluded to be a potent TxA2 receptor antagonist.

Animals↗
PubMed1988

Alprazolam does not inhibit the metabolism of nortriptyline in depressed patients or inhibit the metabolism of desipramine in human liver microsomes.

In 10 patients treated with nortriptyline, the steady-state plasma concentrations of the parent drug and the active 10-hydroxy metabolite were very similar before and during concomitant treatment with alprazolam (0.5 mg orally t.i.d.). In human liver microsomes the 2-hydroxylation of desipramine was not inhibited by alprazolam. The absence of an inhibition by alprazolam on the hydroxylations of nortriptyline in vivo and of desipramine in vitro indicates that alprazolam is not metabolized by the debrisoquine hydroxylase.

Adult↗
PubMed1988

Genetic differences in preferences for morphine and codeine in Lewis and Fischer 344 inbred rat strains.

Preferences for morphine and codeine in two inbred strains of rats, Lewis and Fischer 344 (F344), were systematically investigated using the drug-admixed food (DAF) procedure. Rats were allowed access to food only between 10:00 a.m.-4:00 p.m., but allowed free access to water. The rats were allowed to choose either DAF (0.5 mg/g) or normal food on the first day and then were allowed access only to DAF on the second and third days. After this schedule was repeated 10 times, they were again allowed to choose either DAF or normal food for a successive 8 days. In both strains, preferences for morphine and codeine rapidly increased; the preferences in Lewis rats were significantly higher than those in F344 rats during the daily choice trials. In the range of 0.25 to 1 mg/g for the DAF concentration, there was a negative correlation between the preference and concentration in Lewis and F344 rats, except in the codeine group of F344 rats. When a test dose (60 mg/kg and 30 mg/kg, s.c., in Lewis and F344 rats, respectively) of morphine or codeine was given at 30 min before the beginning of the choice trial, Lewis rats, but not F344 rats, showed a significantly lower preference for the respective drug. The above results indicate that genotype is an important determinant of the degree of preferences for morphine and codeine.

Animals↗
PubMed1988

Participation of autonomic nerve in tonsillar focal infection.

Participation of the autonomic nerve in tonsillar focal infection was investigated by measuring neurotransmitters, receptors and microvibration. In focal infection patients, the volume of norepinephrine in the tonsil increased significantly and the number of a-adrenergic receptors decreased. These findings suggest that the focally infected tonsil exhibits a high degree of sympathetic nerve activity. The ratio of N-type in microvibration decreased systematically, which indicates some imbalance or immaturity of the autonomic nervous system in focal infection patients. Based on this data, the production mechanism of tonsillar focal infection was speculated from the point of view of the autonomic nerve.

Autonomic Nervous System↗
PubMed1988

[[Determinants of the decline in the total marital fertility rate in the early 1970s]].

The author examines "the relationship between the total marital fertility rate and the cohort marital fertility pattern in Japan since the late 1960s. We calculated parity-duration-year-specific marital fertility rates and conducted comparisons among them cohort by cohort and period by period. In addition, we carried out a decomposition of the change in total marital fertility rates into the tempo and quantum components on two different assumptions about future completed fertility. By calculating the first-birth, second-birth and third-birth timing indices, we could specify the effect due to a change of birth timing for each parity on the variation of the total marital fertility rate." It is found that "given that the drop in the total fertility rate in the early 1970s is largely attributable to a decrease in the total marital fertility rate, most of the drop in the total fertility rate in this period is also attributable to the change in second-birth timing over marriage cohorts since the middle 1960s and the temporal disturbance in second-birth timing in marriage cohorts of the early 1970s." (SUMMARY IN ENG)

Asia↗
PubMed1988

Thoracic disc herniation. Surgical treatment in 23 patients.

The authors' surgical procedure for the treatment of symptomatic thoracic disc herniation has consisted of total discectomy of the involved intervertebral disc, followed by intervertebral body fusion using autogenous iliac bone through an anterior approach. The authors prefer the extrapleural approach to the thoracic vertebrae because of simplified postoperative care with minimum surgical interference with respiratory function. During the past 16 years, 23 patients with symptomatic thoracic disc herniation have been treated by this procedure. Preoperatively all 23 patients presented with some measure of paraplegia, with difficulty in walking. Their clinical presentation was analyzed and diagnostic aids to the thoracic disc herniation by radiographic examinations were assessed. The radiographic abnormality of ossification of the yellow ligament (OYL) coinciding with the involved thoracic disc level was noted. The results in all 23 patients with this procedure were favorable. Based on the results of this series, this procedure is recommended for the treatment of symptomatic thoracic disc herniation.

Adult↗
PubMed1987

Morphology of masticatory motoneurons stained intracellularly with horseradish peroxidase.

Masticatory motoneurons were identified electrophysiologically and stained with horseradish peroxidase (HRP). The masseter motoneurons could be divided into 3 groups on the basis of their dendritic morphology. In contrast, the digastric or mylohyoid motoneurons showed a similar dendritic configuration. These neurons had much developed dendritic trees in the dorsomedial than ventrolateral direction. The first group of the masseter motoneurons had their dendritic trees which extended radially in all directions with a slight preference to project rostrally. These somata were located in the center of the subdivision containing the masseter motoneurons. In the second group, their dendritic arbores had a polarity extending hemispherically. These neuronal somata were located in the medial, ventral, and lateral regions of the subdivision. For the masseter motoneurons in the two groups and jaw-opening motoneurons, the dendritic swellings were frequently observed in the distal branches. The third group had their dendritic trees which were much simpler in configurations with less tapering or branching than those of other neurons examined. Furthermore, a wide variety of dendritic spines and appendages, and no dendritic swellings, observed in the third group were distinct from other neurons stained. The dendritic trees of the jaw-closing and -opening motoneurons were confined to the individual subdivisions. There were no instances in which axon collaterals were observed for well-stained 16 axons.

Action Potentials↗
PubMed1987

Extraocular muscles in the microphthalmic rat.

The extraocular muscles in a mutant microphthalmic strain of rat were studied. The eyeball of this strain of rat is reduced to about a third in diameter of that of the normal rat. Nevertheless, in the orbit of the mutant rat, every one of the extraocular muscles was identified; their origins and courses were the same as in the normal rat, but differences existed in the insertions. These insertions could be classified into three groups: Group A (retractor bulbi): like normal insertion into the eyeball. Group B (superior rectus and superior oblique): attachment of tendonlike insertions to each other; these muscles come from opposite directions and form a loop. Group C (lateral, medial, and inferior rectus and inferior oblique): insertion into connective tissue surrounding the reduced eyeball. The volume of each muscle of the mutant rat was smaller than that of the normal rat; moreover, significant differences existed in the degree of reduction in the volume of each muscle group classified according to the change of insertion. In the group A muscle the volume was only 33% of the normal volume, whereas group B was 74% and group C was about half of normal.

Animals↗
PubMed1987

Quantitative analysis of the oculomotor nuclei in the mutant microphthalmic rat.

A quantitative analysis of the oculomotor, trochlear, and abducens nuclei was carried out in the mutant microphthalmic rat. In this strain of rat, the eyeball is reduced to about one-third in diameter, and there is no optic nerve. Nevertheless, this strain possesses all the types of extraocular muscles; however, the volume of these muscles is reduced from 33 to 74% of the normal values. The oculomotor, trochlear, and abducens nuclei in this mutant rat were found in the same location as in the normal ones. Moreover, the neurons in these nuclei in the microphthalmic rat did not appear to be any different from those in the controls. The neuronal population of these nuclei was reduced by 63% (oculomotor), 50% (trochlear), and 61% (abducens) of normal values, respectively. The long axis of all neurons of these nuclei in the microphthalmic and normal rats was measured. In all three nuclei of both strains, the size histograms showed a unimodal distribution ranging from 10 to 35 micron, with peaks at 20 to 25 micron. There was no significant difference between the normal and mutant strains. Consequently, the only influence of the shrinkage of the muscles which they supply was seen in the reduction of the cell populations of these nuclei.

Abducens Nerve↗