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Biomedical subjects

K Otani

Publications and source records attributed to K Otani.

At least 199 records · Page 11Linked to original sources
PubMed1990

Histo-chemical studies on the anti-ulcer effect of bamboo grass in rats.

Oral administration of a hot-water extract (Folin) of bamboo grass (Sasa albomarginata Makino & Shibata) significantly reduced the incidence of water-immersion and restraint stress-, ethanol-induced and indomethacin-induced gastric ulcers in rats. Histological examination of the Folin-treated gastric mucosa showed that microscopic blood clots overlaid the superficial epithelium, maintaining the cellular integrity of gastric mucosa, especially against stress ulcer. In addition, Folin suppressed the incidence of hyperaemia and a decline of acid mucopolysaccharides in the ethanol-induced ulcer. Folin suppressed a release of histamine from rat mast cells, and stabilized erythrocytes and accelerated their agglutination under acid conditions. These results suggest that a microscopic haemostatic effect of Folin reinforced by a membrane-stabilizing effect might be responsible for the prevention of the gastric lesions.

Administration, Oral↗
PubMed1990

[Perinatal brain injuries and subsequent epilepsy: a study on intraventricular hemorrhage in preterm infants and hypoxic-ischemic encephalopathy in full-term infants].

The clinical course of symptomatic epilepsy caused by intraventricular hemorrhage (IVH) in 7 preterm infants and hypoxic-ischemic encephalopathy (HIE) in 9 full-term infants were followed up for more than 2 years and 6 months. West syndrome was the first manifestation of epilepsy in 10 cases (IVH: 4, HIE: 6), and all 16 patients had severe neuropsychiatric deficits. Comparing with children without epilepsy, IVH grades III and IV, mechanical ventilation for more than 6 days and neonatal convulsions in the patients with IVH, and mechanical ventilation and neonatal convulsions in the patients with HIE, were significantly related to the risk of subsequent epilepsy. These findings suggest that the degree of brain injuries may be predictive of the development of epilepsy during infancy and early childhood in the patients with IVH or HIE.

Brain Ischemia↗
PubMed1990

[Chronological change of EEG findings in a case of pyridoxine dependency seizures].

A patient of pyridoxine dependent seizures was reported. He was born at 34 weeks' gestation and weighted 2,760 g. Apgar scores were 6 and 9 at 1 and 5 minutes, respectively. He showed the first seizure 2 hours after his birth. Phenobarbital, phenytoin, sodium valproate, diazepam and clonazepam were not effective. Pyridoxal phosphate (50 mg) was given intravenously, resulting in suppression of convulsions. However, muscle tonus was severely depressed. In EEG, a discontinuous pattern was found in quiet and indeterminate sleep on the 2nd day of life. At 5th week multifocal spikes were found, and the discontinuous pattern persisted. Ictal discharges at 13th week showed generalized, continuous, irregular and high voltage slow waves with multifocal spikes. At 27th week of life, high voltage slow waves disappeared and multifocal spike discharges decreased. At 2 years and 10 months of age, the patient was suffering from athetotic cerebral palsy and severe mental retardation. Pyridoxal phosphate at the doses of 35-40 mg/kg/day had been administered. Irritability sometimes occurred and additional 50 mg of pyridoxal phosphate controlled this irritability effectively.

Administration, Oral↗
PubMed1990

[Radiation-induced malignant skin tumors in the hands of five doctors].

Radiation-induced malignant skin tumors in the hands in 3 surgeons, one physician, and one dentist are reported. The latent period of the irradiation ranged between 16 years and 34 years. Clinically, small keratotic lesions were seen in 4 doctors and a large tumor the remaining doctor. On histological examination, one of the tumors was a squamous cell carcinoma, 3 were carcinomas in situ, and the fifth was a basal cell carcinoma with a squamous cell carcinoma. While the occupational hazard of developing malignant skin tumors following irradiation have decreased recently, this paper emphasizes precautions should be taken when diagnosing and caring for cancer patients.

Adult↗
PubMed1989

Physiological and morphological characteristics of periodontal mesencephalic trigeminal neurons in the cat--intra-axonal staining with HRP.

Intra-axonal recording and horseradish peroxidase (HRP) injection techniques were employed to define the response properties of periodontal mechanoreceptive afferents originating from the trigeminal mesencephalic nucleus (Vmes) and their morphological characteristics. The periodontal Vmes neurons were classified into two types: slowly adapting (SA) and fast adapting (FA) types. The central terminals of 7 SA and 4 FA afferents were recovered for detailed analyses. The whole profile of SA and FA neurons were unipolar in shape and their cell bodies were located in the dorsomedial parts of the Vmes. The united (U) fiber traveled caudally from the soma to the dorsolateral aspect of the trigeminal motor nucleus (Vmo), where it split into the peripheral (P) and C fibers with a T- or Y-shaped appearance. The P fiber joined the trigeminal sensory or motor tract. The C fiber descended caudally within Probst's tract. All 3 stem fibers issued main collaterals. The main collaterals of all neurons examined formed terminal arbors in the supratrigeminal nucleus (Vsup) and all but two SA neurons projected to the intertrigeminal region (Vint), while the projections to other nuclei of the trigeminal motor nucleus (Vmo), juxtatrigeminal region (Vjux), main sensory nucleus (Vp) and oral nucleus (Vo.r) differed between SA and FA afferents and between neurons of the same type. The SA and FA neurons were classified into three and two subgroups, respectively. The major differences in central projections between the two types were that all the FA neurons projected to the Vp or Vo.r but none of SA type and this relation was reversed in the projection to the Vjux, and that more than half of SA neurons projected to Vmo but only one FA neuron to the Vmo. The Vmes neurons which sent their collaterals into the Vmo had the P fiber passing through the tract of the trigeminal motor nerve. The average size of somata and mean diameters of U fibers and main collaterals from C fiber were significantly larger in SA neurons than FA neurons. The average size of fiber varicosities became smaller in the following nuclei, Vmo, Vsup, Vp, Vint and Vo.r, but not significant between the two functional types. The functional role of the periodontal Vmes afferents to jaw reflexes was discussed particularly with respect to their central projection sites in the brainstem nuclei.

Action Potentials↗
PubMed1989

Central terminations of periodontal mechanoreceptive and tooth pulp afferents in the trigeminal principal and oral nuclei of the cat.

Intra-axonal recording and horseradish peroxidase (HRP) injection techniques were employed to define the response properties of low-threshold mechanoreceptive periodontal afferents and of the tooth pulp afferents and the morphological characteristics of their axon arbors in the nucleus principalis (Vp) and rostrodorsomedial (Vo.r) and dorsomedial parts (Vo.dm) of the nucleus oralis (Vo). The central terminals of 3 fast adapting (FA) and 4 slowly adapting (SA) periodontal afferents and 4 tooth pulp (TP) afferents were recovered for detailed analyses. Stained axons in the trigeminal sensory tract ascended and descended (bifurcating fibers), or descended without bifurcation (descending non-bifurcating fibers). The ratio of the bifurcating fibers to the descending non-bifurcating fibers was about three to one for each type of afferents. The main collaterals given off from the ascending branches terminated in the Vp. Most collaterals given off from the descending branches terminated in the Vo with the exception of few instances. In case of the FA afferents, the ascending branches gave off all main collaterals into the Vp with rostrocaudal and dorsoventral continuities in their arbors, whereas the descending branches gave off all main collaterals, except two collaterals, into the Vo with rostrocaudal discontinuities. The projections from the FA afferents to the Vo.dm was predominant in terms of the number of boutons and the length of preterminal and terminal branches. In case of the SA afferents, the collaterals from the ascending and descending branches formed rostrocaudally and dorsoventrally discontinuous terminal arbors. In terms of the density of boutons the SA afferents were divided into two subtypes. One had a preferential projection into the Vp or Vo, whereas others lacked a selective projection. In case of the TP afferents, the main collaterals of the ascending branches formed partially overlapping terminal arbors, but the terminal arbors formed by the collateral of the descending branches did not overlap. The frequency of collaterals of the TP afferents was less than that of the other types of afferents. The terminal arbors including the density of boutons of the pulpal afferents were less extensive than those of the other types of afferents. The average size of varicosities became smaller in the following subdivisions. Vp, Vo.r and Vo.dm for SA and TP afferents. The size of varicosities of the TP afferents was smaller and that of the FA afferents was larger than that of the SA afferents.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1989

The intersegmental anastomoses between spinal nerve roots.

Frequency and morphological characteristics of the intersegmental anastomoses between the spinal roots were investigated in 100 adult spinal cords from the cervical to lumbar segments. The frequencies of dorsal root anastomoses were 61, 7, and 22% of the cervical, thoracic, and lumbar cords, respectively. On the other hand, the incidence of anastomosis between the ventral roots was significantly low in both the cervical (10%) and lumbar (5%) cords as compared with that between the dorsal roots in these regions (P less than .01). No anastomotic connections were found in the thoracic ventral roots. The anastomoses were classified into four types: types A and B; the borders between the spinal segments were cranially and caudally shifted, respectively; type C, anastomosis attached to the spinal cord at the border between the segments; and type D, anastomosis bridged between the adjacent rootlets and coursing parallel to the cord. The proportions of the four types at each spinal level disclosed that type A was most commonly observed compared with the other three types in the dorsal roots (P less than .01). In the lumbar cord, the proportion of type C anastomosis between the dorsal roots increases noticeably toward the sacral level, while a complementary decrease occurred in type A. In the cervical ventral roots, types C and D predominated over the other two types (P less than .01). The lumbar ventral roots contained types B and/or C. Type D anastomosis occurred exclusively in the cervical segments.

Humans↗
PubMed1989

Projections from the superior colliculus to the ventral lateral geniculate nucleus in the hereditarily microphthalmic rat.

Projections from the superior colliculus (SC) to the ventral lateral geniculate nucleus (LGNv) were studied in hereditarily microphthalmic and normal rats by means of wheatgerm agglutinin conjugated with horseradish peroxidase (WGA-HRP). Unilateral injection of a tracer into the LGNv in normal rats revealed WGA-HRP positive neurons on both sides of the SC. In the ipsilateral SC, most of the labeled neurons were distributed in the upper part of the stratum opticum (SO) and the lower part of the stratum griseum superficiale (SGS). A few labeled neurons were also found in the same layers of the contralateral SC. After unilateral injections of the tracer into the LGNv of microphthalmic rats, labeled neurons appeared in similar layers of the SC on both sides. However, the number of labeled neurons in the ipsilateral SC decreased to 30% of normal, whereas on the contralateral side these neurons were apparently more numerous than those in normal rats. The soma size of the labeled SC neurons in microphthalmia was not significantly different from normal. These results indicate fundamentally that tecto-LGNv projecting neurons exist in microphthalmic rats despite the fact that they lack optic nerve afferents. Furthermore, the present results, taken together with our previous results, indicate that the diminution in the number of tecto-LGNd neurons was severest (3%), the tecto-LGNv neurons less severe (30%) and the tecto-LP neurons least severe (50% of that of normal).

Animals↗
PubMed1989

Induction of physical dependence on pentobarbital by new infusion method in the rat.

1. A new intermittent intravenous infusion method was developed for the induction of tolerance to and physical dependence on pentobarbital in rats. 2. Female and male rats were injected with pentobarbital (20 mg/kg/injection) through an implanted intravenous cannula. 3. The rats were allowed to receive an injection after the completion of a fixed amount of behavioral activity counted from the preceding injection, and therefore, the sedative and hypnotic effects of pentobarbital were used as an index in the determination of the injection intervals. 4. During pentobarbital treatment, the number of pentobarbital injections per day rapidly increased and stabilized (approximately 40: male, approximately 30: female) on the third to fifth day. 5. Upon withdrawal, the female and male rats who were maintained on pentobarbital administration of more than 30 and 40 injections/day for approximately 10 days manifested withdrawal signs which included spontaneous convulsion. 6. These results suggest that a new infusion method exists to produce a high degree of physical dependence in rats on a short-acting barbiturates, pentobarbital.

Animals↗
PubMed1989

Clinical and electroencephalographical follow-up study of early myoclonic encephalopathy.

We report a clinico-electroencephalographical follow-up study on a male patient with early myoclonic encephalopathy. Frequent massive and fragmentary myoclonic seizures, and myoclonic-clonic seizures were the initial symptoms at the age of 3 days. EEG revealed a suppression-burst pattern at the onset in which burst phases often coincided with myoclonic seizures. Subsequently, non-epileptic erratic myoclonus, various partial seizures and flexor spasms were observed. The partial seizures ceased at around 4 months of age, while the non-epileptic myoclonus and flexor spasms have persisted beyond the age of 6 months. The EEG pattern evolved into atypical hypsarhythmia at two months of age. No specific biochemical or neuroradiological findings were disclosed. His neuropsychiatric development was arrested from the onset. These observations suggest that early myoclonic encephalopathy is an independent epileptic syndrome and that it might be different from early-infantile epileptic encephalopathy described by Ohtahara.

Anticonvulsants↗
PubMed1989

Involuntary movements associated with mianserin treatment. A case report.

A case showing various involuntary movements during mianserin treatment and after a withdrawal of mianserin is described. This is the first case report of mianserin-induced involuntary movements. The report suggests that these symptoms can occur with a therapeutic dose of mianserin in certain susceptible patients.

Adult↗
PubMed1989

[Pharmacological actions of S-145, a novel thromboxane A2 antagonist, in various smooth muscles].

Antagonistic actions of S-145 ((+-)-5(Z)-7-[3-endo[(phenylsulfonyl)amino]bicyclo[2.2.1] hept-2-exo-yl]heptenoic acid) against U-46619, a thromboxane A2 mimic, were studied using isolated thoracic aorta of the rat and the trachea, lung parenchyma and ileum of the guinea pig. S-145 as well as SQ-29548 and ONO-3708 inhibited the contraction of aorta induced by U-46619 in a concentration-dependent manner. The IC50 value of each compound was 1.4, 14.5 and 52.6 nM. S-145 also inhibited contractions of the aorta induced by high concentrations of PGE1, PGE2 and PGF2 alpha, but failed to affect the responses to K+, Ca2+, NE, 5-HT, and angiotensin II. Contractions of trachea and lung parenchyma of the guinea pig induced by U-46619 were concentration-dependently inhibited by S-145, but those induced by histamine and leukotriene D4 were not affected. Ileac contractions by PGE2 and PGF2 alpha were not inhibited by S-145. The (+)-isomer of S-145 was more potent and the (-)-isomer was less potent than S-145 for antagonistic action against U-46619. These results suggest that S-145 is a potent and specific antagonist to the thromboxane A2 receptor; and in the aorta, the thromboxane A2 receptor may respond to high concentrations of PGs.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1989

[[Proportional hazards model analysis of women's reproductive career in present-day Japan]].

The 1st section of this paper, using a method to decompose a change in the total marital fertility rate into the quantum and tempo effects, confirmed the major effect of birth timing on the 1970s trends in the total marital fertility rate based on the pooled data of the 8th and 9th Japanese National Fertility Surveys of 1982 and 1987, respectively. In the next section, proportional hazards model analyses of the 1st, 2nd, and 3rd birth functions for the pooled data made it clear that the 1st and 2nd birth intervals among the marriage cohorts since the end of the 1960s were shorter than those in the early 1960s even after having controlled for other variables. Given that 1 conception or more can occur during a birth interval, proportional hazards model analyses were again utilized to examine the effects of various variables on the time elapsed since marriage and the 1st conception, the time between the end of the 1st pregnancy and the 2nd conception, and the time between the end of the 2nd pregnancy and the 3rd conception. The authors found that the 1st-conception probability of the marriage cohorts since the late 1960s was smaller than that of predecessors, while the 2nd-conception probability was not affected by marriage cohort. In the last section, a logistic regression analysis of the probability of induced abortion showed that the probability of aborting a 2nd pregnancy decreased in the 1970s compared with that in the early 1960s. When a proportional hazards model analysis of the 2nd birth function was applied after omitting those cases where the 1st pregnancy did not result in birth and/or the 2nd pregnancy was aborted, the strong effect of marriage cohort on the 2nd birth probability was substantially diluted. These facts suggest that the shortened 2nd birth interval in the 1970s was partly caused by the shrinking probability of aborting a 2nd pregnancy in this period.

Abortion, Induced↗