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Biomedical subjects

Y Tani

Publications and source records attributed to Y Tani.

At least 217 records · Page 12Linked to original sources
PubMed1988

Class switching from gamma 3 to gamma 2b in a murine pre-B cell line.

Class switching from gamma 3 to gamma 2b production at pre-B cell stage was observed in an Abelson virus-transformed murine immature cell line that is able to perform VH to DJH recombinations followed by class switch recombinations. A series of Southern blotting experiments indicates that the class switching from gamma 3 to gamma 2b was mediated by the deletion mechanism of the intervening CH genes on the expressed chromosome and that the break points in the switch recombinations might be different from each other among six independent switching events from gamma 3 to gamma 2b. This in vitro switching system should provide us with much information on the mechanisms of class switch recombination.

Abelson murine leukemia virus↗
PubMed1988

Production of Formaldehyde by Detergent-Treated Cells of a Methanol Yeast, Candida boidinii S2 Mutant Strain AOU-1.

Treatment of cells of a methanol yeast, Candida boidinii, with the cationic detergent cetyldimethylbenzyl-ammonium chloride (Cation M2) improved the production of formaldehyde. Formaldehyde production was improved twofold with respect to the initial amount of formaldehyde and 1.61-fold with respect to the final amount of formaldehyde after a 12-h reaction under optimized detergent treatment conditions. The treatment caused formaldehyde and formate dehydrogenases to leak out of the cells more rapidly than catalase, but there was no leakage of alcohol oxidase. The improvement in formaldehyde production was considered to be due to the increased permeability of yeast cell membranes and to lower activities of formaldehyde and formate dehydrogenases in Cation M2-treated cells than in intact cells. Changes in the ultrastructure of the cells were observed upon Cation M2 treatment. Several developed peroxisomes were observed in intact cells. After Cation M2 treatment, the cells were obviously damaged, and several peroxisomes seemed to have fused with each other.

Journal Article↗
PubMed1988

[Behavioral effects of quinupramine, a new tricyclic antidepressant].

The effects of a new tricyclic antidepressant quinupramine (5-(3-quinuclidinyl)-10,11-dihydro-5H-dibenz [b, f] azepine) on various animal behaviors were examined in mice and rats and compared with those of imipramine, amitriptyline and maprotiline. Quinupramine antagonized haloperidol-induced catalepsy and tetrabenazine-induced ptosis and potentiated methamphetamine- and apomorphine-induced stereotyped behavior. These effects were almost the same as or even more potent than those of imipramine and amitriptyline. Quinupramine decreased locomotor activity in mice, but potentiated methamphetamine-induced hyperactivity to a greater degree than imipramine and amitriptyline. On the other hand, quinupramine inhibited muricide in accumbens-lesioned rats, but did not prominently inhibit muricide in olfactory-bulbectomized and raphe-lesioned rats. Quinupramine decreased the duration of immobility in low doses without affecting locomotor activity, and this effect was almost the same as that of imipramine and amitriptyline and more potent than that of maprotiline. Quinupramine antagonized physostigmine lethality and oxotremorine-induced tremor, suggesting that quinupramine has a central anticholinergic action. Quinupramine, like imipramine and amitriptyline, has no effect on conditioned avoidance behavior. In conclusion, quinupramine generally has the same behavioral profile as typical tricyclic antidepressants, but it has somewhat different effects from imipramine and amitriptyline since quinupramine has a potent central anticholinergic and a weak antimuricide effect.

Animals↗
PubMed1988

[A phase II study of carboplatin in small cell lung cancer].

A phase II clinical trial of carboplatin for small cell lung cancer was conducted in 20 institutions of the National Chest Hospital lung cancer cooperative study group. Carboplatin was administered by three dosing schedule of 300 mg/m2, 400 mg/m2 and 450 mg/m2. Out of 30 patients registered in this trial, 29 patients were evaluable for response and toxicity. Seven patients achieved PR with the response rate of 24.1%. The response rates for 300 mg/m2, for 400 mg/m2 and for 450 mg/m2 were 25.0%, 8.3% and 44.4%, respectively. Thrombocytopenia (less than 7 x 10(4)/mm3) and leukopenia (less than 3,000/mm3) were observed at 25.9% and 17.2% of cases, respectively. Nausea/vomiting was also observed at an incidence of 55.2% with mild degree. No renal and ototoxic damage was observed.

Adult↗
PubMed1988

Electroencephalographic effects of the new antidepressant paroxetine in the rabbit.

The electroencephalographic (EEG) effect of (-)-trans-4-(4'-fluorophenyl)-3-(3',4'-methylene-dioxyphenoxy-met hyl)piperidine hydrochloride (paroxetine, BRL 29060A) a new antidepressant, was investigated in conscious rabbits with chronic electrode implants and was compared with those of imipramine and amitriptyline. Paroxetine induced an arousal pattern of the spontaneous EEG consisting of low voltage fast waves in the cortex and synchronization of hippocampal theta waves with decreased amplitude, while imipramine and amitriptyline elicited drowsy patterns of the spontaneous EEG. Paroxetine failed to suppress the EEG arousal responses induced not only by auditory stimulation but also by electrical stimulation of the mesencephalic reticular formation, centromedian thalamus and posterior hypothalamus, whereas imipramine and amitriptyline markedly inhibited these responses. The EEG arousal response induced by i.v. injection of physostigmine 0.2 mg/kg was slightly enhanced by paroxetine, while the response was significantly suppressed by imipramine and amitriptyline. Paroxetine, imipramine and amitriptyline showed no significant effect on the photic driving response and recruiting response. Paroxetine did not show any effects on the limbic afterdischarges elicited by either hippocampal or amygdaloid stimulation, while imipramine and amitriptyline caused an initial suppression followed by slight enhancement of these afterdischarges. These results indicate paroxetine to be an antidepressant of a new type which induces a sustained arousal pattern of the spontaneous EEG and has no central anticholinergic action.

Amitriptyline↗
PubMed1987

Selective use of the VHQ52 family in functional VH to DJH rearrangements in a B precursor cell line.

AT11-2, an Abelson virus-transformed cell line has DJH complexes on both chromosomes and is able to form functional variable region genes by the joins of VH genes to the DJH complexes during culture. Therefore we examined which VH gene family was used in functional VH to DJH recombinations in AT11-2. Surprisingly, of 32 independent functional VH to DJH recombinational events in AT11-2, 31 events used the VH segments of the VHQ52 family, and the remaining one used the VH segment of the VH7183 family. Thus, we describe here the first B precursor cell line that almost selectively uses the VHQ52 family in functional VH to DJH rearrangements. The selective use of the VHQ52 family in this B precursor cell line strongly indicates nonrandom use of VH gene families, and the existence of a stage at which the VHQ52 family is preferentially used during the normal development of early pre-B cells and has important implications for understanding the ontogeny of VH repertoire development. Furthermore, this cell line should prove extremely valuable in further studies of this kind.

Animals↗
PubMed1987

Loss of the activity of human coagulation factor XII by a chymotrypsin-like protease activated in rat mast cells during degranulation with compound 48/80.

Mediator release from mast cells is an initial step in the immediate-type hypersensitivity. Thus, the interaction of neutral proteases released from mast cells with plasma kallikrein-kinin system was investigated. Two proteases, chymotrypsin-like (CHY) and trypsin-like (TRY) proteases, were activated in purified rat mast cells after degranulation with compound 48/80. Three fourths of the CHY activity remained in the cell residue, and the activity was inhibited by chymostatin, whereas most of the TRY activity was released in the medium and was inhibited by leupeptin. The incubation of rat or human plasma with degranulated mast cell (DMC) suspension did not cause the activation of plasma prekallikrein, but did cause a loss in the activity of coagulation factor XII, as ascertained by the lack of activation of prekallikrein in either the DMC-treated plasma by glass powder or in the incubation of DMC-treated human plasma with factor XII deficient plasma activated by kaolin. The prekallikrein and high-molecular-weight kininogen levels were sufficient for activation of factor XII.

Animals↗
PubMed1987

Start of mu-chain production by the further two-step rearrangements of immunoglobulin heavy chain genes on one chromosome from a DJH/DJH configuration in an Abelson virus-transformed cell line: evidence of secondary DJH complex formation.

A variant was selected from an Abelson virus-transformed cell line with identifiable and distinguishable DJH rearrangements on both chromosomes. Southern blotting experiments suggested that this variant resulted from a secondary DJH complex formation accompanied with the deletion of one of the DJH rearrangements on the same chromosome. Furthermore, this variant started making mu-chains by the further functional join of a VH gene to the secondarily formed DJH complex. Thus, we describe here the first evidence of a secondary DJH complex formation.

Abelson murine leukemia virus↗
PubMed1987

Differentiation of an Abelson virus-transformed immature B precursor cell line under the expression of tyrosine kinase activity of v-abl oncogene product.

The expression of v-abl oncogene during the in vitro differentiation of an Abelson-virus-transformed immature B precursor cell line from immunoglobulin-null to intracytoplasmic mu-positive cells and further to intracytoplasmic gamma 2b-positive cells was examined. The results showed no significant alteration in the amounts and tyrosine kinase activity of v-abl oncogene product during differentiation, indicating that B cell differentiation processes are independent of v-abl functions.

Abelson murine leukemia virus↗
PubMed1987

Changes of brain monoamine contents in three models of experimentally induced muricide in rats.

Monoamine levels were measured by high performance liquid chromatography with electrochemical detection in seven brain regions of three models of experimentally-induced muricide (mouse-killing behavior) in rats (bilateral olfactory bulbectomized rats: OB rats, midbrain raphe nuclei lesioned rats: Raphe rats and nucleus accumbens lesioned rats: Acc rats). Noradrenaline (NA) levels in the lateral hypothalamus (LH) and ventromedial hypothalamus (VMH), 3,4-dihydroxyphenylacetic acid (DOPAC) levels in LH and homovanillic acid (HVA) levels in the frontal cortex (FC) were increased in all three muricide models. In LH, serotonin (5-HT) levels increased in Acc rats and the 5-hydroxyindoleacetic acid (5-HIAA)/5-HT ratio was reduced in OB rats. But in VMH an increase in NA level was not accompanied by any changes of other amines in three muricide models except for 5-HT and 5-HIAA in Raphe rats. In the mamillary body (MB), NA level was increased and 5-HIAA/5-HT ratio was decreased in both OB and Acc rats. Monoamine changes in the amygdaloid nuclei were different in three muricide models, suggesting that the role of monoamines in various nuclei of the amygdala may be different in each muricide model. The present findings suggest that both noradrenergic (LH and VMH) and serotonergic function (LH and MB) may play an important role in exhibiting muricide of OB, Raphe and Acc rats, while dopaminergic function (LH and FC) may be related rather to hyperirritability elicited in these three muricide models.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Porcine high molecular weight kininogen: its purification and properties as a thiol proteinase inhibitor as compared to human high molecular weight kininogen.

1. High mol. wt kininogen (HMW kininogen) was purified to a homogeneous state from porcine plasma. 2. The protein exhibited a strong inhibitory activity for thiol proteinases such as ficin, papain and calpain I, whereas it did not inhibit serine proteinases, trypsin and chymotrypsin. 3. The mol. wt, isoelectric point, amino acid and carbohydrate compositions, stabilities to temperature and pH, kinetic constants, and immunological properties of the porcine HMW kininogen were determined and compared with those of human HMW kininogen.

Amino Acids↗
PubMed1987

Isolation and Characterization of a Catabolite Repression-Insensitive Mutant of a Methanol Yeast, Candida boidinii A5, Producing Alcohol Oxidase in Glucose-Containing Medium.

Mutants exhibiting alcohol oxidase (EC 1.1.3.13) activity when grown on glucose in the presence of methanol were found among 2-deoxyglucose-resistant mutants derived from a methanol yeast, Candida boidinii A5. One of these mutants, strain ADU-15, showed the highest alcohol oxidase activity in glucose-containing medium. The growth characteristics and also the induction and degradation of alcohol oxidase were compared with the parent strain and mutant strain ADU-15. In the parent strain, initiation of alcohol oxidase synthesis was delayed by the addition of 0.5% glucose to the methanol medium, whereas it was not delayed in mutant strain ADU-15. This showed that alcohol oxidase underwent repression by glucose. On the other hand, degradation of alcohol oxidase after transfer of the cells from methanol to glucose medium (catabolite inactivation) was observed to proceed at similar rates in parent and mutant strains. The results of immunochemical titration experiments suggest that catabolite inactivation of alcohol oxidase is coupled with a quantitative change in the enzyme. Mutant strain ADU-15 was proved to be a catabolite repression-insensitive mutant and to produce alcohol oxidase in the presence of glucose. However, it was not an overproducer of alcohol oxidase and, in both the parent and mutant strains, alcohol oxidase was completely repressed by ethanol.

Journal Article↗