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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 325 records · Page 18Linked 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

Two stages of excitability change of pontine pause neurons in the cat.

Spikes of single pontine pause neurons (PNs) in the cat were recorded extracellularly and identified by observing cessation of tonic discharges before and during the fast phase of vestibular nystagmus. PNs were antidromically activated from the excitatory burst neuron area. Antidromic spikes were abolished or their peak latencies were prolonged during particular periods within a nystagmic cycle. The excitability change in PNs indicated by alteration of the antidromic responses occurred with two stages; i.e. a moderate decrease in excitability before the onset of the fast phase and an abrupt, intense decrease starting form the beginning of the fast phase.

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↗
PubMed1983

Characterization of the vasodilator action of antihypertensive drug budralazine.

Intravenous injection of 1-[2-(1,3-dimethyl-2-butenylidene)hydrazino]phthalazine (budralazine) to anesthetized dogs resulted in an increase in cardiac output and regional blood flow in various vascular beds, and a fall in mean blood pressure with a decreased total and regional vascular resistance. Budralazine produced a dose-related increase in femoral blood flow in anesthetized dogs when injected into the femoral artery. The vasodilator drug relaxed either KCl(K+)- or noradrenaline (NA)-induced contractions of isolated rabbit aorta in a concentration-dependent manner. In the K+-depolarized aorta, it also produced a concentration-related inhibition of contractile response to cumulative addition of Ca2+. Intra-arterial injection of budralazine dilated dose-dependently the isolated perfused vascular bed of rabbit ear constricted by either K+ or NA. Budralazine, at effective antihypertensive oral dose, was without significant effect on cyclic nucleotide levels in the aorta of spontaneously hypertensive rats (SHR). These results indicate that budralazine, like hydralazine, produces vasodilation through a direct effect on vascular smooth muscle which may result at least in part from its inhibitory effect on vascular Ca2+ fluxes.

Anesthesia↗
PubMed1983

[Effect of BCG (Bacillus Calmette Guérin) sensitization on the generation of tumor specific killer T cells].

Effector cells of augmented resistance against a syngeneic MC-1 tumor in C57BL/6 mice sensitized with BCG were determined by Winn test, and the following results were obtained: Sensitization of mice with BCG (1.0 mg/mouse) augmented resistance against primary and secondary inoculation of MC-1 tumor. Peritoneal exudate cells of tumor-bearing mice showed a growth-inhibitory activity against MC-1 tumor in Winn test. Sensitization with BCG augmented such an activity of PEC. Augmented resistance was ascribed to a plastic dish-nonadherent, nylon wool column-nonadherent and Thy 1.2-positive cells.

Animals↗