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Biomedical subjects

Y Sano

Publications and source records attributed to Y Sano.

At least 451 records · Page 25Linked to original sources
PubMed1979

The location of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence. Experimental immunohistochemistry and radioimmunoassay.

The location of the perikarya of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence were studied by immunohistochemistry and radioimmunoassay after placing stereotaxic electrolytic lesions in several parts of the hypothalamus. The principal location of the cell somata was found to be in the ventral part of the medial preoptic area; their pathways were classified into a main baso-lateral pathway and an accessory descending pathway branching off from the former. The main pathway was found to cross in the vicinity of the corresponding neuronal perikarya. The central median eminence and the dorsal and ventral walls of the tubero-infundibular sulcus of the caudal part of the median eminence are innervated mainly by the baso-lateral pathway. On the other hand, the rostral and most caudal protions of the median eminence are innervated principally by the descending pathway and have a subsidiary dual innervation. The projection of LH-RH neurons to the OVLT is believed to originate from perikarya adjacent to this circumventricular organ.

Animals↗
PubMed1979

Detection of catecholamine and luteinizing hormone-releasing hormone (LH-RH) containing nerve endings in the median eminence and the organon vasculosum laminae terminalis by fluorescence histochemistry and immunohistochemistry on the same microscopic sections.

Distribution of catecholamine (CA) and LH-RH nerve endings in the median eminence (ME) and the organon vasculosum laminae terminalis (OVLT) of the rat was investigated by application of fluorescence histochemistry and immunohistochemistry on the same sections of the tissue. In the ME, those two kinds of endings coexisted in the lateral portion of the middle part of ME, and in the wall of tuberoinfundibular sulcus, where they might be considered to have functional correlation. In the OVLT they were also distributed in fairly near distance, but they were not so closely associated as observed in the ME.

Animals↗
PubMed1979

Suppressor mutation in Pseudomonas aeruginosa.

Suppressor mutations were identified in Pseudomonas aeruginosa, and a comparison was made with Escherichia coli suppressor systems. A suppressor-sensitive (sus) derivative of a plasmid, RP4 trp, and several Sus mutants of IncP1 plasmid-specific phages, were isolated by using E. coli. Plasmid RP4 trp (sus) was transferred to P. aeruginosa strains carrying trp markers which did not complement RP4 trp(sus), and Trp+ variants were selected. Some, but not all such revertants, could propagate PRD1 Sus phages, and these mutants were found to be supressor positive. Plating efficiencies of various Sus phages on these strains were compared with on E. coli strains carrying known suppressor genes. The results suggested that the Pseudomonas suppressors were probably amber suppressors. In iddition, some Sus phages (PRD1sus-55, PRD1sus-56) were obtained which, although apparently of the amber type for E. coli, were able to propagate equally well on sup+ or sup strains of P. aeruginosa. On the other hand, several mutants of phage PRR1 which were suppressed in E. coli were not suppressed by the P. aeruginosa suppressor. Suppressor-sensitive mutants were also isolated with P. aeruginosa bacteriophages E79 and D3.

Bacteriophages↗
PubMed1979

Histological and cytological studies on the liquor contacting peptidergic neurons in the preoptic nucleus of the Japanese eel (Anguilla japonica).

Liquor contacting peptidergic neurons (LCPNs) in the preoptic nucleus of the Japanese eel (Anguilla japonica), are investigated submacroscopically, light microscopically, electron microscopically (transmission and scanning) and histochemically. LCPNs appear in 8--13 per cent of all neurons constituting the preoptic nucleus and their cytoplasm contains many secretory granules stained by aldehyde-thionin or chrome hematoxylin. LCPNs have an epithelial cell-like polarity and their cytoplasmic organella shift to the supranuclear region. LCPNs are classified into three types (A, B, C) according to the liquor contacting portion of the cell: Granular type A neuron (40--50 x 40--50 microns 2), the cell of which is in contact with the cerebrospinal fluid (CSF), is the most common type and distributed in the ventral portion of the preoptic nucleus; this neuron is not connected with the neighboring ependymal cells by tight junctions. Bipolar type B neuron (60 x 30 micron 2), contacts the CSF with the tip of it cell process and is scattered throughout the preoptic nucleus; the cell is connected with the surrounding ependymal cells by tight junction. Bipolar type C neuron (60 x 30 micron 2) possesses a cell process protruded into the third ventricle and is distributed in the dorsal portion of the preoptic nucleus; this also is connected with the adjacent ependymal cells by tight junction. Regardless of type, all LCPNs exhibit a positive acetylcholinesterase and a negative ATPase reaction. Numerous fluorescent varicosities of monoaminergic nerve terminals are closely associated with the cell bodies of the LCPN. LCPNs are likely regulated by monoaminergic fibers.

Acetylcholinesterase↗
PubMed1979

LH-RH neuron system of the newt by immunohistochemical study.

The location of LH-RH producing neurons, the pathways and terminal distributions of their fibers in the newt, Cynops pyrrhogaster were studied immunohistochemically. The LH-RH positive perikarya are located in the nucleus of the diagonal band of Broca and the medial septal nucleus. No LH-RH immunoreactive neuronal perikarya could be detected in the diencephalon. The pathways of fibers originating from the LH-RH reactive neurons were classified into three groups: the first project to the median eminence, the second to the olfactory bulb and the third to the habenular nucleus. The latter two pathways are extrahypothalamic, similar to those in mammals. These observations are briefly discussed and compared with those in other amphibian and mammalian species.

Animals↗
PubMed1978

Distribution of LH-RH nerve endings in the median eminence of proestrus female rats: fluorescence and peroxidase anti-peroxidase (PAP) immunohistochemistry.

The morphological distribution of the nerve terminals containing LH-RH in the hypothalamus especially in the median eminence of the proestrus female rat was demonstrated by immunohistochemistry, using FITC and peroxidase antibody. The terminals containing LH-RH were classified into four groups on the topographic relationship. LH-RH nerve processes terminated mainly in the infurdibular radix within an elliptical zone surrounding the bases of the infundibular recessus. The heaviest concentration of LH-RH terminals immunohistochemically demonstrated lay on each side of the region extending from the dorsal part of tuberoinfundibular sulcus to the lateral part of the external layer of the superior labium of the infundibulum. We were unable to detect any neuronal soma with the immunoreactivity to LH-RH in the hypothalamic gray matter. The distributional patterns of LH-RH, GH-RIH and monoamine in the median eminence as well as their relationships were briefly discussed.

Animals↗
PubMed1978

A radioimmunoassay of serum 16alpha-hydroxypregnenolone with specific antiserum.

A radioimmunoassay for plasma 16alpha-hydroxypregnenolone has been developed using anti-16alpha-hydroxypregnenolone antiserum produced in rabbits immunized with 16 alpha-hydroxypregnenolone-3-succinate-bovine serum albumin. Radioimmunoassay data were processed and analysed for its validity using a four parameter logistic curve fitting routine with use of the IBM call system. The assay system was satisfactory for a routine use. The 16alpha-hydroxypregnenolone concentrations in the umbilical cord blood at term ranged from 223 to 324 ng/ml. Gas liquid chromatographic analysis revealed a similar result, and also the presence of this steroid in the adrenal gland of the human fetus at midtrimester was confirmed. It is speculated that this steroid is secreted from fetal adrenals.

17-alpha-Hydroxypregnenolone↗
PubMed1978

Biosynthetic pathways for corticoids and androgen formation in human fetal adrenal tissue in vitro.

Eleven incubations of minced human fetal adrenal tissue from two fetuses at midtrimester of pregnancy terminated for socio-economic reasons, were performed for different periods of time with labelled pregnenolone, progesterone, 17alpha-hydroxyprogesterone and deoxycorticosterone (DOC). The order of magnitudes of enzyme activity when progesterone was used as a substrate and incubated with midterm fetal adrenals was 17alpha-hydroxylase, 21-hydroxylase and 16alpha-hydroxylase. The activity of 3beta-hydroxysteroid dehydrogenase and delta5-4 isomerase was almost negligible as compared to other enzymic activities as mentioned above. Similar biosynthetic pathways for adrenal corticoids formation were observed in human fetal adrenals as reported in human adults and animals; once progesterone was converted into DOC, further 17alpha-hydroxylation did not take place.

Adrenal Cortex Hormones↗
PubMed1978

Inhibition of fetal adrenal 21-hydroxylase by naturally occurring steroids.

Inhibitory effects of naturally occurring steroids on 21-hydroxylase activity were determined by measuring the initial conversion rate of 17-hydroxyprogesterone (17alpha-hydroxy-4-pregnene-3, 20-dione) to 11-deoxycortisol (17alpha, 21-dihydroxy-4-pregnene-3, 20-dione) in incubation experiments with the microsomal fraction (10,000--105,000 X g percipitate) of the human fetal adrenal gland. The apparent Michaelis constant (Km) for conversion of 17-hydroxyprogesterone was 13.3 X 10(-6)M. Human fetal adrenal 21-hydroxylase was inhibited by some of the steroids produced in the feto-placental unit. The following steroids acted as competitive inhibitors of the reaction; progesterone (Ki = 20.0 X 10(-6)M), 11-deoxycortisol (Ki = 87.5 X 10(-6)M) and estradiol-17beta (Ki = 87.5 X 10(-6)M). The most potent inhibitor among the estrogens was estradiol-17beta.

Adrenal Glands↗
PubMed1978

Abnormal serum immunoglobulin levels in Down's syndrome patients.

Serum immunoglobulin levels were measured in 20 patients with Down's syndrome and 16 mentally retarded cerebral palsy control patients. Significant elevation of IgG and IgD levels were found in the Down's syndrome as compared with the control patients. Serum IgD level in Down's syndrome individuals significantly decreased with increasing age. Serum IgA level was significantly elevated in older Down's syndrome patients but showed no change in younger Down's syndrome patients. Serum IgM and IgE levels were slightly elevated in Down's syndrome patients, but these differences were not significant. The elevated immunoglobulin levels in Down's syndrome individuals seem to be a response to increased frequency of infection.

Adolescent↗