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Biomedical subjects

K Yoshimura

Publications and source records attributed to K Yoshimura.

At least 505 records · Page 28Linked to original sources

[Pharmacological studies of a new sleep-inducer, 1H-1,2,4-triazolyl benzophenone derivatives (450191-S) (I). Behavioral analysis].

The behavioral effects of 450191-S and its metabolites were investigated in mice, rats, cats and rhesus monkeys, and they were compared with those of related benzodiazepines (BDZ) such as diazepam and nitrazepam. Oral administration of 450191-S consistently caused sedation without excitability in mice and rats, and it was only 1/2 to 1/266 as potent as the BDZ in producing motor incoordination as assessed by traction, rotarod performance and inclined screen tests in mice, induced much less ataxia in cats and monkeys, and inhibited respiration in anesthetized cats. The locomotor activities of mice and rats measured by Animex and the open field test were not affected by 450191-S, but rearing and preening decreased with 450191-S as with the BDZ. 450191-S was equipotent with nitrazepam and 2 to 6 times more potent than diazepam and estazolam in potentiating chlorprothixene-induced hypnosis and thiopental-Na-induced anesthesia. These effects were not different with successive 14-day administration of 450191-S. Anti-pentylenetetrazol, picrotoxin and bicuculline convulsions of 450191-S had the same potency as nitrazepam, but caused much less anti-electroshock convulsion than the BDZ. 450191-S had potent antianxiety activity as observed by anti-aggressive and anti-conflict activities and had almost the same effect as diazepam on operant behavior. The metabolites M-1, M-2, M-A and M-3 showed approximately the same potency as 450191-S in inducing anesthetic potentiation and antianxiety activity, but they were much more potent in causing disturbance of the somatic functions. These results indicate that 450191-S possesses inhibitory effects on the central nervous system, including a potent sleep-inducing effect, and is characterized by markedly weak muscle relaxant activity and motor incoordination.

Aggression↗

[Pharmacology of a new sleep inducer, 1H-1,2,4-triazolyl benzophenone derivative, 450191-S (II). Sleep-inducing activity and effect on the motor system].

The sleep-inducing activity and effect on the motor system of the 1H-1,2,4-triazolyl benzophenone derivative 450191-S were examined behaviorally, electroencephalographically and electro-physiologically with various species of animals and were compared with those of diazepam, nitrazepam, estazolam and triazolam. In the rhesus monkey, rabbit and rat with chronically indwelling brain electrodes, 0.6 to 3 mg/kg, p.o. of 450191-S caused a shorter latency of sleep onset, an increase of and a stable continuity of slow wave deep sleep (SWDS) with higher amplitude, and the appearance of clear spindle bursts in the slow wave light sleeping (SWLS) state with little muscle relaxation. Animals treated with nitrazepam and/or estazolam showed a smaller increase in SWDS and its unstable continuity with remarkable disturbance of gait. The doses needed to induce sleep in the rhesus monkey were 0.6 to 1 mg/kg p.o. for 450191-S, 3 mg/kg for nitrazepam, 1 mg/kg for estazolam and 0.3 mg/kg for triazolam. The cat treated with 450191-S showed the phenomena caused by benzodiazepines (BDZ), i.e., behavioral excitation and decrease of frequencies in the hippocampal theta waves. The suppressive effects of 450191-S on the EEG arousal reaction and/or blood pressure elevation induced by hypothalamic stimulation in the rabbit suggested that the inhibitory effects acted on the posterior hypothalamus to the limbic system. The inhibitory effect of 450191-S on the amygdaloid kindling in the rat was as potent as those of diazepam and nitrazepam. Successive daily oral administration of both 3 mg/kg of 450191-S and/or 3 to 6 mg/kg of nitrazepam for 15 days in the rabbit caused slight decrease of SWDS and increase of fast wave (REM) sleep (FWS). During the withdrawal period of both compounds, a slight but insignificant increase in the waking state was noticed for 1 to 2 days, but not a rebound increase of FWS. Intravenously administered 450191-S showed the same action as BDZ on the spinal reflex and the dorsal root potential of the rat; it particularly acted on the crossed extensor reflex in the same manner as the commercial BDZ sleep inducers.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

[Clinical study on tissue polypeptide antigen (TPA) as a tumor marker].

We evaluated whether assay of tissue polypeptide antigen (TPA) in sera is valuable for the determination of cancer stages compared to other tumor markers such as CEA, AFP, beta2-microglobulin, ferritin, and elastase-1. The study population consisted of cancer patients (33 gastric cancers, 7 colo-rectal cancers and 15 hepatomas), 169 patients with benign gastro-enteric diseases and 72 healthy volunteers. The percentage of positive cases for TPA (higher than 200 u/l) was 61% in gastric cancer, 71% in colo-rectal cancer and 87% in hepatoma. In certain non-cancerous conditions, such as gastric ulcer (active stage), acute hepatitis and chronic hepatitis, the TPA levels were increased over the level of healthy volunteers. There was no significant correlation between TPA and the other tumor markers. Our study suggests that TPA may be useful in the identification and evaluation of cancer patients.

Adolescent↗

[Pharmacological studies on drug dependence. (III): Intravenous self-administration of some CNS-affecting drugs and a new sleep-inducer, 1H-1, 2, 4-triazolyl benzophenone derivative (450191-S), in rats].

The present study examined comparative self-administration of some typical CNS-affecting drugs with a new sleep-inducer, 450191-S, in rats, Most animals self-administered both methamphetamine and cocaine in an extremely stable and invariable fashion with cycles of alternating responding and non-responding periods during the day and at night. Response frequency increased in proportion to a fixed-ratio value. An initial increase in response rate followed by cessation of the responding was observed during extinction. Sixty-five percent of the rats tested self-administered morphine in a relatively variable and less stable fashion. Total daily morphine intake was directly related to the unit dose. Eighty-three percent of the rats self-administered pentazocine. Fifty and sixty-four percent of the rats maintained self-administration of phenobarbital and diazepam, respectively, with higher intake at night than during the day. Responding persisted at a low rate for several days during extinction. Abrupt withdrawal of 450191-S caused the same slight weight loss and moderate decrease in food intake as those seen with diazepam and nitrazepam, and cross-physical dependence between 450191-S and diazepam was found. Self-administration of 450191-S at 0.5-2.5 mg/kg/infusion was observed with 2 out of 11 rats, which was much less than that found with diazepam. These results suggest that 450191-S possesses little, if any, drug dependence liability of the tranquilizer type.

Animals↗

A new immunoglobulin marker.

In an examination of 16 human immunoglobulin lambda-light chains, one was found to have amino acid substitutions which have not previously been reported for the constant region of the lambda-chains. It involved in two positions: an arginine instead of lysine at position 130, and a leucine for glutamine at position 195 (Sh numbering (1) ). The structural variation is tentatively designated as "Is" marker.

Amino Acid Sequence↗

Analysis of deposits on high water content contact lenses.

Deposits on soft contact lenses of high water content were investigated morphologically and chemically and compared with those on conventional soft contact lenses of poly (2-hydroxyethyl methacrylate). The material of the lenses examined in this investigation was the crosslinked copolymer of methyl methacrylate and N-vinylpyrrolidone with a water content higher than 70%. Morphologically, the deposits on the lenses with high water content were found to have no characteristics distinguishable from those on conventional lenses. By the electron microscopic observation of the cross section of a lens that had become opaque, it was confirmed that the deposit was on the lens surface and that no deposit was within the lens. Some spots on the lenses were recognized as colonies of microorganisms, but the majority of the spots had no involvement by microorganisms. Surface analysis with Fourier transform infrared spectrometer (FT-IR) confirmed that the main component of the filmy deposit was protein. Protein was detected in most of the deposits. The amino acid compositions of the proteins were found to be close to that of lysozyme. From the elemental analysis of several spots, silicon, aluminum, iron, and some other elements were detected. The structural analysis of some spots by a laser Raman microprobe (MOLE) revealed the existence of lipids. In several cases, the deposits were found to have grown around a defect of the lens surface. A mechanism for the formation of deposits is suggested.

Amino Acids↗

Construction of a Bacillus subtilis cloning vehicle with heterologous DNA sequence.

A cloning vehicle, pFTB91, for the Bacillus subtilis host was constructed with DNA fragments heterologous to the host chromosome. It consists of three DNA fragments: (i) chromosomal DNA of Bacillus amyloliquefaciens which complements the leuA and ilvC mutations in B. subtilis; (ii) a B. amyloliquefaciens plasmid DNA that supplies an autonomously replicating function; and (iii) a HindIII fragment of Staphylococcus aureus plasmid pTP5 that carries gene tetr, conferring the TetR phenotype. It has sufficiently low DNA homology to prevent its integration into the host chromosome in recombination-competent cells of B. subtilis. It is 9.3 kb, and approx. 10 copies are present per chromosome. The SalI and KpnI sites in the ilvC+ and tetr genes, respectively, could be used for selection of recombinant plasmids by insertional inactivation. The plasmid has unique sites for EcoRI, PstI, and XbaI.

Bacillus↗

Pharmacological characterization of the inhibitory effects of neurotensin on the rabbit ileum myenteric plexus preparation.

Neurotensin in picomolar concentrations caused a concentration-related inhibition of the spontaneous contractile activity of the longitudinal muscle from the rabbit isolated ileum. Neurotensin was approximately 100 times more potent than adrenaline and about 10000 times as active as adenosine triphosphate (ATP) in producing similar relaxations. The neurotensin-induced inhibitory effect did not follow activation of adrenoceptors or P1-purinoceptors since the effect of the neuropeptide was not antagonized by a combination of phentolamine plus (-)-propranolol, nor by pretreatment with theophylline. Tetrodotoxin did not reduce the potency of neurotensin in relaxing the rabbit ileum, suggesting that the neurotensin-induced inhibition is not neuronally mediated. The inhibitory responses of neurotensin were blocked non-competitively by apamin. The inhibitory effect of neurotensin was short-lived with the subsequent development of tachyphylaxis, which was not crossed to the inhibitory action of adrenaline or ATP. Similarly, when tachyphylaxis to adrenaline or to ATP was established, the inhibitory action of neurotensin was unaffected. Desensitization was characterized by a gradual shift of the neuropeptide concentration-response curve to the right and downwards. Preincubation of rabbit ileum strips with 10 nM dynorphin (1-13) significantly increased the inhibitory action of neurotensin.

Adenosine Triphosphate↗

Distribution of heterogeneous and homologous plasmids in Bacillus spp.

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 microgram/ml), sodium dodecyl sulfate (0.2 micrograms/ml), or novobiocin (1 microgram/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.

Anti-Bacterial Agents↗