Biomedical subjects

Y Sano

Publications and source records attributed to Y Sano.

At least 271 records · Page 15Linked to original sources

PubMed1989

Immunohistochemical studies on the development of tyrosine hydroxylase- and serotonin-immunoreactive neurons in fetal dorsal raphe tissue transplanted into the anterior eye chamber of adult rats.

Pieces of tissue containing dorsal raphe nuclei of fetal rat brains were transplanted into the anterior eye chambers of adult rats. The differences between the developmental patterns of catecholaminergic and serotonergic neurons--especially the extension of their axonal processes--in the grafts were immunohistochemically examined using tyrosine hydroxylase (TH) and serotonin antisera. At an early stage after transplantation (3 days), TH-positive neurons appeared in grafts that had and had not been pretreated with a monoamine oxidase inhibitor (MAOI, Nialamide), while serotonin-positive neurons were demonstrated only in the grafts that had undergone MAOI pretreatment. Morphological differences in the growth pattern in the experimental milieu between the TH and serotonin neurons were also demonstrated: at this early stage, the somata of the TH neurons were multipolar and stellate shaped and possessed several distinct processes, while the serotonin neurons were ovoid shaped and lacked such processes. One week to 1 month after transplantation, the number of TH-positive fibers gradually increased, but their distribution was restricted to the area surrounding the cell bodies of the TH neurons in the graft. However, the processes of the serotonin neurons formed a dense plexus in the graft, and a small number of these fibers extended into the host iris 1 week after transplantation. By one month after the operation, the density of the serotonin fibers had gradually increased throughout the graft, and protruding serotonin fibers formed a network of varicose fibers in the host uveal tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Morphological aspects of neurons as secretory cells.

The concept of a neurosecretory system consisting of a secretory center (production of bioactive substances in neuronal soma), a transport pathway (transport by axonal flow) and a neurohemal organ (storage and release at nerve endings) has been established through a series of histological studies on the hypothalamic magnocellular nuclei by two pioneers, Scharrer and Bargmann, together with their co-workers. In the early stages of the investigation, these actively secreting neurons were considered as exceptional neurons, separated from ordinary ones. However, since the application of modern techniques, such as electron microscopy, immunohistochemistry, and in situ hybridization, have made progress in tracing the cytological course from the gene expression to the release of bioactive product, it has become obvious that the classical definition of neurosecretion must be extended to include a variety of neuroepithelial derivatives, such as aminergic and peptidergic neurons and also paraneurons. At present, all neurotransmitters and neuro-modulators can be regarded as secretory substances produced in neurons. Newly developed precise techniques, e.g., a tracing method with a computer graphic system for the demonstration of axonal arborizations, have led to a dramatic change in our understanding of the fine details of cytological features, offering much more complicated structures than images presented by the classical impregnation technique. Immunohistochemically demonstrated serotoninergic neurons in the brain have revealed enormous reticular extensions and anastomoses of beaded processes which were previously unknown. Neurons composing the nervous system show greatly varied shapes and structures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[Studies on the retentive force of clasps. 1. An effect of the material and technician].

Wire clasps and cast clasps are the most common retainers for removable partial dentures. The purpose of this study was to investigate the differences in the material and the variation among individual technicians in the retentive force of both clasps. The clasps were made in accord with the clinical method for experimental metallic model of the left mandibular second premolar and the retentive force of each clasp was measured by a pull-out test. The results were as follows: 1. Both types of clasp showed a large variation in the retentive force among the technicians, but no particular tendency was observed in the differences between wire and cast clasps. 2. There was no significant difference between the two types of clasp in the retentive force. 3. Due to the differences in individual technical skills, it seems to be difficult to make wire clasps with a standardized retentive force.

Denture Design↗

PubMed1989

Natural course of unoperated intracranial arteriovenous malformations: study of 50 cases.

The clinical course of 50 patients with conservatively treated intracranial arteriovenous malformations (AVM's) was followed, most of them for more than 5 years. The average follow-up period was 13.4 years. The initial symptom was intracranial bleeding in 29 patients (58%) and seizure in 15 patients (30%). Small and deep-seated AVM's were associated with a high incidence of bleeding; however, repeated hemorrhages were not necessarily indicative of a poor prognosis. Children younger than 15 years had a better prognosis than adults. There was no correlation between pregnancy and bleeding. In the hemorrhage group, the incidence of rebleeding was 6.9% in the 1st year after initial rupture, 1.91% per year after 5 years, and 0.92% per year after 15 years. The overall incidence of rebleeding was 34.5% in the hemorrhage group. Of the 50 patients, 37 (74%) had a good clinical outcome, four (8%) had a fair outcome, and four (8%) had a poor outcome; five patients died.

Adolescent↗

PubMed1989

[Influence of surface properties on the bending strength of OPTEC porcelain].

Influence of properties on bending strength of OPTEC porcelain, an experiment on four-point bending test was studied using four kinds of specimens (5 X 3 X 20) made of OPTEC porcelain (INCISAL) each of which was surface-treated; (1) glaze firing (no treatment) (2) polishing by emery paper #150 (3) polishing by alumina powder (0.3 microns) (4) glaze firing after polishing by emery paper #150 The test specimens were immersed in distilled water maintained at 37 +/- 1 degrees C broken into four-point bending at 1.0 mm/min, and their bending jig had on inner and outer span of 5 mm and 15 mm. The specimens graze fired after polishing had the highest bending strength, of 914 kg/km2, those polished with alumina powder, 831 kg/cm2, those graze 763 kg/cm2, and those polished with emery paper 705 kg/cm2. In conclusion, the bending strength of the porcelain was decreased by the surface roughness.

Dental Porcelain↗

PubMed1989

[Airway responsiveness measured by body plethysmograph connecting a circuit of an inhalation system of serially concentrated bronchoconstrictant].

We developed a new methodology to examine the bronchial response to the bronchoconstrictants, acetylcholine and methacholine. An inhalation device was connected to the body plethysmograph circuit so that a minute inhalation of serially concentrated bronchoconstrictant could be quickly switched to the circuit of the measurement of the airway resistance. The following were calculated: airway responsiveness in terms of sensitivity, provocative dose to increase the airway resistance up to 35% from the baseline. PC35 or PD35 and the reactivity, the slope of the declining specific airway conductance and %delta SGaw. The airway responsiveness was examined in asthmatics, COPD outgrew -childhood asthma patients and normal subjects. These three groups were categorised differently from each other in both sensitivity and reactivity.

Acetylcholine↗

PubMed1989

The fine surface architecture of the primate ciliary body with special regard to the pars plana.

The fine surface architecture of the pars plana of the ciliary body was studied by scanning electron microscopy (SEM) in young and adult primate eyes following the removal of zonular fibers by hydrolysis with hydrochloric acid. In the young eye, the internal surface of the pars plana was characterized by a series of meridional ridges and grooves and, in the posterior region, by conspicuous surface invaginations on the ridges. In the adult eye, the meridional ridges in the anterior pars plana were smaller than in the young eyes and in a varying configuration, and the meridional grooves among the ridges were wide. In the mid-pars plana, spine-like architectures were observed leaning parallel to each other toward the lens, along the course of the zonular fibers. In the posterior pars plana, the internal surface exhibited a reticularly multilayered appearance with interstices of various sizes. In incompletely digested specimens, the zonular bundles were found to dissociate into fan-shaped off-shoots, and were observed entering the meridional grooves and the surface invaginations on the ridges. The procedure used in the present study was considered to be highly useful for SEM observation of the surface morphology of the ciliary body.

Age Factors↗

PubMed1989

[Study on the clinical significance of pharmacia rast RIA in animal allergy].

To study the usefulness of Pharmacia animal allergen discs, the specific IgE antibodies in the sera of patients with allergy to pet or laboratory animals were measured with the use of those discs. The coincidental ratio between skin test to cat hair and RAST to cat epithelium was 73.3%, however between skin test to dog hair and RAST to dog epithelium or dog dander it was 66.7% or 60.0%, respectively. The rate of RAST positive do dog dander was higher than to dog epithelium, and so it seems to be the optimum allergen for screening. The correlation between RAST value to dog epithelium and dog dander was good, but there was no relationship between cat and dog epithelium, it seems that cross-antigenicity is low. In laboratory animals, the rate of RAST positive was in decreasing order: guinea pig, mouse, rabbit, rat, hamster. The rate of RAST positive to serum proteins of rat and mouse was lower than to epithelium and urine proteins. It seems not to be useful.

Adolescent↗

PubMed1989

Peritoneal fluid cytology and prognosis in patients with endometrial carcinoma.

Cytologic examination was performed on peritoneal fluid collected from a total of 235 consecutive patients with endometrial carcinoma who underwent laparotomy as the initial treatment at the Cancer Institute Hospital from 1971-1985. The rate of cases positive for cancer cells in the peritoneal cytologic examination was 18.7% for all stages (44 of 235 cases). In stage I endometrial carcinoma, the 5-year and 10-year cumulative survival rates with positive peritoneal cytologic findings were 91.6 and 90.0%, respectively; those in cases with negative cytologic findings were 90.2 and 90.2%, respectively, with no significant difference. The recurrence rate in the same stage was 12.0% for cytologically positive cases versus 9.5% for negative cases. In stages II and III, no significant difference was noted in the survival rate between nine cases with positive peritoneal cytologic findings without macroscopic peritoneal metastasis and 47 comparable cases with negative cytologic findings. Therefore, in endometrial carcinoma, the presence of malignant cells in peritoneal fluid is not a useful prognostic factor.

Female↗

PubMed1988

Temperature dependence of the structure of aggregates of tobacco mosaic virus protein at pH 7.2. Static synchrotron small-angle X-ray scattering.

The small-angle X-ray scattering (SAXS) method using a synchrotron radiation source was applied to the study of the self-aggregation process of tobacco mosaic virus protein (TMVP) at a concentration of 5.0 or 12.0 mg ml-1 in 50 mM or 100 mM-phosphate buffer (ionic strengths approx. 0.1 and 0.2, respectively) at pH 7.2 in the temperature region of 4.8 to 25.0 degrees C. This paper presents the results of static measurements of SAXS. Sedimentation velocity experiments were performed simultaneously under the same conditions. These results are qualitatively parallel to those of the SAXS measurements, although the size of stacked disks derived from the SAXS measurements is larger than that derived from the sedimentation experiments, suggesting a change in the equilibrium conditions in the centrifugal field. Qualitative analysis of the SAXS data with model simulation calculations implies that the aggregation of TMVP consists of two steps: (1) the aggregation of A-protein comprising a few subunits to form double-layered disks; and (2) the random polymerization of double-layered disks by disk-stacking. Increase in temperature, ionic strength or protein concentration induced TMVP to polymerize to form a double-layered disk or a quadruple-layered short rod with consumption of A-proteins, accompanied by a small number of multi-layered short rods. The SAXS results indicate that the A-protein and the multilayered short rods are polydisperse with respect to size and shape, i.e. the mixture of A-protein, double-layered disks and multi-layered short rods coexists in the equilibrium state without pressure-induced partial dissociation of TMPV as observed during normal ultracentrifugation, and even under solution conditions in which the formation of double-layered disks or higher-order aggregates is favored.

Capsid Proteins↗

PubMed1988

Positive inotropic effects and receptors of calcitonin gene-related peptide (CGRP) in porcine ventricular muscles.

Calcitonin gene-related peptide (CGRP) in porcine ventricular muscles. positive inotropic effects in the isolated, electrically driven false tendon of the porcine heart. Specific CGRP-binding sites were present in solubilized membrane fractions; the dissociation constant (Kd) and the maximum binding (Bmax) were 50.4 pM and 180 fmol/mg protein, respectively. SDS-PAGE analysis of CGRP-binding sites revealed the molecular mass of 70 K and 120 K. Few CGRP-like immunoreactive nerves were present in the ventricular muscle layer. These results indicate that CGRP activates specific receptor sites on the ventricular muscles and causes positive inotropic responses. CGRP receptors in ventricles are likely to be activated by circulating CGRP.

Animals↗

PubMed1988

Immunohistochemical evaluation of the neurotoxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on dopaminergic nigrostriatal neurons of young adult mice using dopamine and tyrosine hydroxylase antibodies.

The recovery of dopamine (DA) neurons in young adult mice from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) damage was analyzed at various times after MPTP treatment with DA and tyrosine hydroxylase (TH) immunohistochemistry and also by chemical DA assay. A remarkable discrepancy in the recovery rate of DA and TH reactivities of the nigral neurons was observed: the TH immunoreactivities of both cell bodies in the substantia nigra and terminals in the neostriatum were markedly reduced 4 days after MPTP. However, these reactivities progressively improved and almost fully recovered after 25 days, while the DA immunoreactivities were maximally depleted 10 days after, and the depletion continued even through the 25th day. The alteration of DA levels was correlated with that of DA immunoreactivity. These findings suggest that a major effect of MPTP on the DA neurons of young adult mice is a transient neurotoxicity, and that the TH content improves more promptly than that of DA.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1988

Reinnervation of serotonin fibers in the denervated rat subcommissural organ by fetal raphe transplants. An immunohistochemical study.

The ability of axonal outgrowth of serotonin neurons in the implanted brain tissue of subcommissural organ (SCO) was immunohistochemically studied. The serotonin neuron system of the experimental rats was completely destroyed by the intraventricular injection of 5,6-dihydroxytryptamine. The raphe region of normal fetal rats was implanted into the caudal part of the third ventricle of the neurotoxic drug pretreated rats. The host brain was examined 3 months after transplantation. The numerous serotonin fibers were distributed in the SCO and periventricular region of the third ventricle of the host brain. The outgrowing serotonin fibers from the raphe transplant seemed to innervate the SCO with the target specificity.

Animals↗

PubMed1988

Studies on steroids. CCXXXIII. Separation and characterization of bile acid disulphates in human urine by high-performance liquid chromatography.

The separation of disulphates of cholate, chenodeoxycholate, deoxycholate and ursodeoxycholate and their glyco and tauro conjugates has been carried out by high-performance liquid chromatography (HPLC) on a reversed-phase column. The chromatographic behaviour of bile acid disulphates was dependent on the position of the sulphate and hydroxy groups and the structure of the side-chain. The method has been applied to the separation and characterization of disulphates in biological fluids without prior deconjugation. The disulphate fraction was obtained from a urine specimen by passing it through a Sep-Pak C18 cartridge, followed by group separation by ion-exchange chromatography on a lipophilic gel, piperidinohydroxypropyl-Sephadex LH-20. Subsequent resolution into individual disulphates was attained by HPLC on Radial-Pak A and Cosmosil 5C18 columns. Taurochenodeoxycholate 3,7-disulphate and taurodeoxycholate 3,12-disulphate in human urine were unequivocally identified on the basis of their behavior in HPLC using mobile phases of different pH.

Bile Acids and Salts↗

PubMed1988

Immunohistochemical localization of atrial natriuretic polypeptide (ANP) in human atrial and ventricular myocardiocytes.

To date, there have been few immunohistochemical investigations of atrial natriuretic polypeptide (ANP) in human cardiac tissue, especially the ventricles. In this study, myocardial tissue was obtained from two sources: the bilateral atria and ventricles at autopsy; and biopsy tissues from the right auricle and left ventricle of a patient with myocardial infarction undergoing surgery. These tissues were examined by the avidin-biotin immunoperoxidase technique using three kinds of primary ANP-antibodies. ANP-immunoreactivity was observed in the perinuclear region of myocytes of all tissues examined. The intensity of the reaction was stronger in atrial tissue, weaker in ventricular tissue. In the later tissue, the positive-staining myocytes were not part of the pulse-conducting system. Although the tissues we studied were not obtained from normal hearts, our data demonstrates that ANP-reactivity can be detected in ventricular myocytes outside the pulse-conducting system.

Atrial Natriuretic Factor↗

PubMed1988

Characteristic structures of serotonin neuron system. An immunohistochemical study.

Since 1982, the authors have carried out intensive immunohistochemical studies on the distribution of serotonin neurons in the central nervous system and have reported the distinctive structures of these nerve cells. In the present study, two characteristic findings are described with special regard to the histophysiological significance: (1) direct innervation of the cerebral arteries by central serotonin neurons and (2) the perineuronal ivylike serotonin plexus.

Animals↗

PubMed1988

Histochemical and electron microscopical demonstration of the sympathetic nerve fibers joining to the fourth and the sixth cranial nerves in rats.

The localization of sympathetic fibers on the floor of the cranium was studied in rats using amine fluorescence histochemistry, neuropeptide-Y (NPY) immunohistochemistry, and electron microscopy. The vast majority of amine fluorescent fibers joined the abducent nerve and were localized in the peripheral zone under the perineurium. After advancing along this nerve for some distance, the fibers diverged into many bundles that converged to form the cavernous plexus at a rostral end of the trigeminal ganglion. On the dorsal surface of the trigeminal ganglion, one or two medium-calibered fluorescent bundles ran inside or in close proximity to the trochlear nerve, while many small-calibered, brightly fluorescent bundles also extended longitudinally in the epidural connective tissue. In rats that had undergone nerve severance, NPY-immunoreactive fibers were detected at the cut ends of the abducent and trochlear nerve. The differing amounts of NPY accumulated at the rostral and the caudal stumps indicated the direction of the NPY-bearing fibers. Electron microscopy confirmed the presence of unmyelinated fibers in both the abducent and trochlear nerves.

Adrenergic Fibers↗

PubMed1988

Brain renin-angiotensin system and the hypothalamic, digitalis-like Na+, K+-ATPase inhibitor in rats.

Since angiotensin (ang) II blockers attenuate the centrally-induced pressor responses to a Na+, K+-ATPase inhibitor, ouabain, a brain renin-ang system is assumed to be involved in this pressor mechanism. Centrally-induced pressor responses to hypertonic saline were also blocked with ang II blockers. Thereby, the increase in the plasma level of digoxin-like immunoreactivity was abolished with simultaneous infusions of an ang II analogue or atrial natriuretic polypeptide (ANP). These results indicate that the pressor responses to sodium salts are mediated via inhibition of the brain Na+, K+-ATPase, and that the brain renin-ang system is involved in this mechanism. We noted the existence of a digoxin-like immunoreactive substance (DLI) containing neurons in the hypothalamus (PVN, SON) with the fibers densely distributed in the AV3V area including OVLT, SFO and the median eminence, an area where receptors for ang II are also distributed (1,2). Since pressor responses to intracerebroventricular (ICV) infusions of hypertonic NaCl are abolished with ICV pretreatment with ang II blockers, a brain renin-ang system may be involved in this mechanism. We then searched for a possible relationship between the central effects of NaCl, a brain renin-ang system and an endogenous Na+, K+-ATPase inhibitor in the hypothalamus.

Animals↗