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Biomedical subjects

N Ohno

Publications and source records attributed to N Ohno.

At least 271 records · Page 15Linked to original sources
PubMed1984

Requirement of anionic groups for the mitogenicity of a fungal mitogen, vesiculogen.

Active site(s) of a B-cell mitogen, vesiculogen, was investigated by means of chemical and enzymic modifications. Vesiculogen is a non-dialyzable fraction of a hot water extract from a fungus, Peziza vesiculosa (Yadomae et al, Microbiol. Immunol. 23, 997 (1979], and was composed of protein (approximately 60%), carbohydrate (approximately 30%), and a small amount of amino sugar, uronic acid, phosphate, and lipid. The mitogenicity was not affected by periodate oxidation, N-acylation, defatting treatment, destruction of the three dimensional structure, protease digestion, nuclease digestion, N-bromosuccinimide treatment, and beta-mercaptoethanol treatment. However, the mitogenicity was decreased by a modification of carboxyl groups, such as 1-ethyl-3(3-dimethylamino propyl)-carbodiimide or dicyclohexylcarbodiimide treatment. Vesiculogen contains a large amount of acidic amino acids. These results suggest that the mitogenicity of vesiculogen is due to the presence of anionic groups, such as aspartic acid and glutamic acid, and that the mitogenic substance is a novel, heat stable polyanionic B-cell activator obtained from Ascomycotina.

Animals↗
PubMed1984

Antitumor activity of a polysaccharide fraction extracted from cultured fruiting bodies of Grifola frondosa.

Antitumor activity of a polysaccharide fraction (GF-1) extracted from cultured fruiting bodies of a fungus, Grifola frondosa, was examined on allogeneic and syngeneic tumors in mice. GF-1 had a marked inhibitory activity against the growth of subcutaneously (s.c.) inoculated Sarcoma 180 by the intraperitoneally (i.p.) injection at 0.5-5.0 mg/mouse for 10 successive days. A significant antitumor activity was also observed when GF-1 at 4.0 mg/mouse was i.p. injected successively on days +1-+5, +7-+11, +14-+18 or +21-+25 if the tumor cells were inoculated s.c. on day 0. Similar results were obtained by a single i.p. injection of GF-1 at 2.0 mg/mouse on day +1, +7, +14 or +21. When GF-1 was injected i.p., intravenously (i.v.) or intratumorally (i.t.), all of them showed an equivalent level of higher inhibitory activity (inhibition ratio; over 90%). However, the oral (p.o.) administration was not effective. The pretreatment of mice with GF-1 at 2.0 or 4.0 mg/mouse for 5 times before tumor inoculation did not show a significant antitumor activity. In addition, GF-1 administered i.p. at varying times before and/or after the tumor inoculation showed no antitumor activity against ascites form of Sarcoma 180. In the syngeneic systems, GF-1 exhibited an antitumor activity against solid form of Meth A fibrosarcoma in BALB/c mice and MM46 carcinoma in C3H/He mice.

Animals↗
PubMed1983

Isolation of laminin from human placental basement membranes: amnion, chorion and chorionic microvessels.

Laminin components were solubilized from basement membranes of amnion, chorion and chorionic microvessels of human placenta without prior protease digestion. These structures, after isolation, were initially processed in a sonicator bath containing a solution of Triton X-100, EDTA and 2M NaCl and the laminins extracted sequentially with 0.5M NaCl, 8 M urea, and 8 M urea + 2% 2-mercaptoethanol + 2% SDS. A high molecular weight (appr. 1 x 10(6)) complex containing laminins was purified by gel filtration on a Sepharose CL-2B column. This complex migrated as a single band on gel electrophoresis before reduction but resolved, after reduction, into four major laminin components, laminin A (350,000 M.W.), laminin M (240,000 M.W.) and laminins B1 and B2 (195,000 and 185,000 M.W.). Laminin M is a new molecular species of this protein.

Amino Acids↗
PubMed1983

A specific radioimmunoassay for corticotropin releasing factor (CRF) using synthetic ovine CRF.

This newly developed specific radioimmunoassay for corticotropin releasing factor (CRF) had a sensitivity range of 25 pg/tube to 4 ng/tube. Intra and interassay coefficient of variation were 4.6% and 9.8%, respectively. Rat median eminence extracts showed a parallel dose response curve with synthetic ovine CRF and a significant cross reaction was not evident with other tested neuropeptides. The highest mean levels of CRF were found in the median eminence (6.61 ng/mg protein). Considerable amounts of CRF were found in the arcuate nucleus, paraventricular nucleus, dorsomedial nucleus, suprachiasmatic nucleus and ventromedial nucleus. The immunoreactive CRF of the rat medial basal hypothalamus coeluted with bioassayable CRF and with iodinated CRF on Sephadex G-75 chromatography. The results indicate that rat hypothalamus contains a CRF similar to ovine CRF.

Animals↗
PubMed1983

Characterization of rat hypothalamic corticotropin-releasing factor by reversed-phase, high-performance liquid chromatography with synthetic ovine corticotropin-releasing factor as a marker.

Reversed-phase, high-performance liquid chromatography (HPLC) was carried out to characterize rat hypothalamic corticotropin-releasing factor (CRF) using synthetic ovine CRF as a marker. Samples were injected onto a stainless steel column (4 X 250 mm) packed with Hitachi gel 3053. The column was eluted using a gradient elution of increasing acetonitrile concentration, in a mixture of NaCl-HCl at a flow rate of 1.0 ml/min, monitoring the column effluent at 220 nm with an UV detector. Fractions eluted every 1-2 min were collected and lyophilized for subsequent CRF bioassay and radioimmunoassay. When various neuropeptide mixtures including synthetic ovine CRF were injected onto the column, synthetic ovine CRF was separated from the other neuropeptides with a gradient of 0-60% acetonitrile in 0.1 M NaCl-0.01 N HCl or 0-08% acetonitrile in 0.05 M NaCl-0.01 N HCl. The median eminence extracts showed two main peaks of CRF bioactivity on HPLC. One (small CRF) coeluted with arginine vasopressin and oxytocin markers, and the other (big CRF) appeared near the position of synthetic CRF and was divided into two peaks. One coeluted with synthetic ovine CRF and the second eluted after synthetic CRF, showing high CRF activity. Three or four peaks of CRF immunoreactivity appeared on HPLC and the main peak appeared after synthetic ovine CRF marker. Our results suggest that rat CRF is different from ovine CRF, and the total lipophilicity of amino acid residues of rat CRF may be higher than that of ovine CRF.

Animals↗
PubMed1983

Biochemical and physicochemical characterization of a mitogen obtained from an oriental crude drug, Tohki (Angelica actiloba Kitagawa).

Chemical composition and physicochemical properties of an immunomodulator, which is a non-dialyzable and acetone precipitable material(s) extracted with hot water from Angelica actiloba KITAGAWA (Yamato Tohki) (AIP), were investigated. AIP was composed of about 90% sugar and 10% protein. The major polysaccharide was identified as pectic substance(s) because its main component sugars were found to be arabinose, glucose, and galacturonic acid by gas liquid chromatographic analysis. The pectic substance(s) was not concerned with the mitogenicity of AIP since the activity was similar before and after pectinase(endo-polygalacturonase) treatment. More than half of the mitogenicity was destroyed by acid or alkali treatment. With pronase treatment, the activity was not affected, but the molecular weight of the mitogen was lowered. In addition, the mitogenic substance was partially purified from AIP by pectinase treatment and Westphal's phenol/water fractionation. The partially purified mitogenic substance(s) was rich in protein. These facts suggest that the mitogenicity of AIP was carried by a heat stable and protease resistant protein.

Amino Acids↗
PubMed1982

[The separation of neuropeptides by high performance liquid chromatography and its application to the analysis of peptides in the rat pituitary neurointermediate lobe (author's transl)].

High performance liquid chromatography (HPLC) was used for the separation of many neuropeptides. Chromatography was carried out using a Hitachi Model 638 high performance liquid chromatograph. Peptides and samples from tissue dissolved in an aqueous buffer were injected into a stainless-steel column (4 X 250mm) packed with Hitachi #3053 (octadecylsilane). The aqueous buffer consisted of NaH2PO4 and H3PO4. After a loading phase (0% organic solvent) of 1 min, the peptides were sequentially eluted at room temperature using a gradient of organic solvent (acetonitrile or methanol, 0-60%). The eluted polypeptides were detected by UV absorbance at 220nm, and then they were collected for subsequent bio and radioimmunoassay using a fraction collector. The gradient of methanol or acetonitrile in 0.02M NaH2PO4, 0.1% H2PO4 was useful for separating small molecular peptides. The gradient of acetonitrile in 0.05-0.1M NaH2PO4, 0.1% H2PO4 was useful for separating many neuropeptides including ACTH related peptides. Retention times of chromatographed polypeptides showed good reproducibility. Good reproducibility was also found in peak areas of these peptides. A linear relationship was observed between the doses of peptides and their peak areas. The extracts of rat pituitary neurointermediate lobe showed several peaks of UV absorbance on PHLC; some of them coincided with AVP, oxytocin, alph-MSH, CLIP and beta-endorphin but others were unidentified. AVP immunoreactivity showed one peak which coincided with the AVP peak of UV absorbance, but ACTH immunoreactivity showed 5-6 peaks. Thus, many polypeptides were well separated using HPLC by changing the eluting condition. The simplicity, speed, good reproducibility and good quality of the separations render this technique suitable for purification and quantitative analysis of neuropeptides, and the combination of HPLC, radioimmunoassay and bioassay gives very fine analysis of neuropeptides.

Animals↗
PubMed1982

Familial Bartter's syndrome and the effect of indomethacin in one family member.

A Japanese family in which a father, daughter and son had hypokalemia and hyperreninemia was investigated. Both father and daughter had reduced vascular sensitivity to angiotensin II; in addition, the daughter had juxtaglomerular cell hyperplasia and dwarf glomeruli. These features are consistent with Bartter's syndrome occurring in 2 successive generations in 1 family. The 12-year-old girl had growth retardation in spite of normal growth hormone secretion. No chromosomal abnormalities were found. Indomethacin administration to this patient in doses sufficient to reduce urinary prostaglandin excretion resulted in a marked improvement of polydipsia and polyuria, and an increase in serum sodium, potassium and chloride concentrations. Even though plasma aldosterone concentrations were reduced to within the normal range, serum potassium concentrations remained low, and plasma renin activity (PRA) remained elevated. Thus it is not likely that hypokalemia is induced only by aldosteronism. These results suggest that prostaglandins are the major determinant of polydipsia, polyuria and high plasma aldosterone levels and contribute to the hypokalemia observed in this patient. However, the failure of complete correction of the hypokalemia and the persistence of the raised PRA with a significant reduction of the prostaglandins suggest the possibility that additional factors are involved in the pathogenesis of Bartter's syndrome.

Adult↗
PubMed1982

Distribution and characterization of corticotropin-releasing factor and arginine vasopressin in rat hypothalamic nuclei.

Corticotropin-releasing factor (CFR) was bioassayed and arginine vasopressin (AVP) radioimmunoassayed from punched-out hypothalamic nuclei. The highest concentration of CFR was found in the median eminence (ME), followed by the paraventricular nucleus (PVN), supraoptic nucleus (SON), suprachiasmatic nucleus (SCN), arcuate nucleus (ARC), dorsomedial nucleus (DMN) and ventromedial nucleus (VMN). The AVP concentration was in the order of ME, SON, PVN, SCN, ARC, VMN and DMN. Sephadex G-25 gel filtration of the ME extracts showed one peak for AVP and two peaks for CRF. One CRF peak appeared on the void volume (big CRF) and the other (small CRF) was coeluted with AVP. Gel filtration of the PVN and SON extracts showed one peak for AVP but three or four peaks for CRF. The addition of anti-AVP serum (AVP-AS) to pituitary cell cultures reduced the CRF activities of AVP and ME extracts by approximately 80 and 40%, respectively. When the small CRF fraction of ME extracts was treated with AVP-AS on affinity chromatography, the unbound fraction (AVP-free) still showed significant CRF activity. Re-examination of CRF concentration using AVP-AS showed that it was still highest in ME, but was significantly higher in PVN than in SON, SCN and ARC. These results suggest that the PVN is an important nucleus for producing corticotropin-releasing hormone.

Animals↗
PubMed1982

The effect of serotonin agonist 1-(trifluoromethylphenyl)-piperazine on corticotropin releasing factor and arginine vasopressin in rat hypothalamic nuclei.

Effects of 1-(m-trifluoromethylphenyl)-piperazine, a serotonin agonist, were examined on rat plasma levels of adrenocorticotropin (ACTH) and arginine vasopressin (AVP), and on hypothalamic contents of corticotropin releasing factor (CRF) and AVP, to investigate the role of brain serotonin in ACTH regulation. Both plasma ACTH and AVP levels increased markedly 30 min after injection of the compound and were still elevated at 80 min. CRF and AVP contents in the median eminence decreased 30 min after injection but returned to the basal levels by 80 min. The AVP content in the supraoptic nucleus was elevated 80 min after injection. The CRF and aVP content did not significantly change in the paraventricular, suprachiasmatic and arcuate nuclei. Serotonin or 1-(m-trifluoromethylphenyl)-piperazine did not stimulate the release of ACTH in pituitary cell cultures. These results suggest that both CRF and AVP were secreted into the portal vessels by 1-(m-trifluoromethylphenyl)-piperazine to release ACTH from the anterior pituitary and that both the ACTH and AVP release were stimulated via the brain serotonergic mechanism.

Adrenocorticotropic Hormone↗