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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 1,279 records · Page 71Linked to original sources
PubMed1983

Affinities for alpha- and beta-adrenoceptor subtypes of YM-09538, a new combined alpha- and beta-adrenoceptor antagonist, by radioligand binding assay.

The binding properties of YM-09538 and some known adrenoceptor agonists and antagonists to alpha- and beta-adrenoceptors were studied by radioligand binding assays using [3H]-prazosin, [3H]-clonidine and (-)-[3H]-dihydroalprenolol ([3H]-DHA). The relative order of potencies of YM-09538 and 5 alpha-adrenergic agents for inhibition of [3H]-prazosin binding to rat brain membranes was as follows: prazosin greater than YM-09538 = phentolamine greater than labetalol greater than yohimbine greater than clonidine. In contrast, the order of potencies of these agents for [3H]-clonidine sites was as follows: clonidine greater than phentolamine greater than yohimbine greater than prazosin greater than YM-09538 greater than labetalol. The rank order of potencies of YM-09538 and 4 beta-adrenergic agents in inhibiting the binding of [3H]-DHA to guinea-pig heart membranes was the same as that to guinea-pig lung membranes: pindolol greater than propranolol greater than labetalol greater than YM-09538 greater than atenolol. Based on Ki values, YM-09538 displayed a 1,380-fold alpha 1-selectivity at alpha-adrenoceptors and no selectivity at beta-adrenoceptors. The biochemical potencies of YM-09538 observed in the present study correlated well with its pharmacological potencies obtained from previously reported literature.

Adrenergic alpha-Antagonists↗
PubMed1983

Digital ulcers/gangrene and immunoglobulin classes/complement fixation of anti-dsDNA in systemic lupus erythematosus patients.

The immunoglobulin classes/complement fixation of anti-dsDNA were studied in sera obtained from 17 systemic lupus erythematosus (SLE) patients with digital ulcers and/or gangrene (Group A); 13 SLE patients with leg ulcer, peripheral neuropathy or livedo (Group B); 24 SLE patients with Raynaud's phenomenon (Group C); and 18 SLE patients with active lupus nephritis (Group D). Antibodies to dsDNA of IgG and IgA classes were commonly present (often in high titers) in Groups A and D. However, complement fixation of anti-dsDNA was more common in Group D than in any of the other 3 groups.

Antibodies, Antinuclear↗
PubMed1983

[Case of immunoblastic sarcoma (IBS)].

A patient with immunoblastic lymphadenopaty which evolved into immunoblastic sarcoma is reported. A 48-year-old female was admitted to our department because of cough and fever. A diagnosis of immunoblastic lymphadenopathy had been made two years before the present admission. Physical examination revealed generalized lymphadenopathy. Chest radiograms showed a left hilar mass. The pulmonary tumor and enlarged lymphnodes were treated by irradiation. Although there was marked improvement at first, she experienced several relapses. One year after the admission, chest radiograms showed multiple pulmonary lesions. She developed pancytopenia and bone metastases. At autopsy, the lymphnodes showed histological evidence of immunoblastic sarcoma; a pulmonary lesion showed immunoblastic lymphadenopathy.

Anemia, Hemolytic, Autoimmune↗
PubMed1982

Chronic myringitis and chronic suppurative otitis media.

Thirty-four chronic myringitis cases were examined by otoscopy, pure tone audiometry, tympanometry, skull X-rays, and bacteriologic study of otorrhea. Five atypical cases are presented in detail. Three of these five cases had a perforation of the tympanic membrane preceding the appearance of typical chronic myringitis. The remaining two cases showed a transient small tympanic membrane perforation during the long course of chronic myringitis. These cases suggest that chronic myringitis could occur in some chronic suppurative otitis media and that myringitis could cause tympanic membrane perforation.

Adult↗
PubMed1982

Enhancement of avoidance-suppressing effect after repeated administration of haloperidol and serum haloperidol in rats.

Adult male rats of the Wistar strain, which were trained under a discriminated lever-press avoidance schedule (intertrial interval; 25 sec. presentation of conditioned stimuli; 5 sec), were given SC 0.025-0.05 mg/kg of haloperidol at fixed intervals of 1, 3-4 and 7 days. The avoidance-suppressing effect of haloperidol was enhanced in parallel to the number of drug administrations until it attained a maximum level. The intensity of the maximum effect tended to be stronger, and the number of administrations necessary to attain it was smaller, when a higher dose was given. When the administration interval exceeded one day, the enhanced effect remained irreversible one month after withdrawal of drug administration. The enhancement of the effect was produced after repeated administrations in an experimental chamber, but not in a home cage. Temporal changes in serum haloperidol concentration were determined 30-90 min after 0.035 mg/kg given SC to the haloperidol-pretreated and saline-pretreated groups. No significant difference in the pharmacokinetic change was detected between the two groups. These results suggest that learning during the drug effect under repeated exposure to a fixed experimental situation influences the enhancing effect.

Animals↗
PubMed1982

The properties of two sea-squirt antigens.

The accuracy of radioimmunoassay (RIA) has been much improved for sea-squirt antigen Gi-x, which is considered to be of higher molecular weight than antigen Ei-M, by using radiolabeled Gi-x as a tracer. Gel chromatography monitored by the improved RIA revealed a wide distribution of molecular weight of Gi-x type antigens, in contrast to Ei-M. However, since a considerable portion of the anti-genic activity gave a single peak in gel chromatography with Sepharose 6B, the substance in the peak fractions was isolated as a fairly homogeneous preparation and referred to as Gi-rep. Gi-rep showed distinct characteristics of Gi-x type antigens and was clearly discriminated from Ei-M by radioimmunometry in vitro. The in vitro observation also suggested that Gi-rep and Ei-M carried a common antigenic determinant (type alpha), but that Ei-M also carried a specific determinant (type beta). The weight-average molecular weights were 1.1 x 10(5) for Gi-rep and 2.3 x 10(4) for Ei-M. Both preparations consisted of acidic glycoproteins with considerable amounts of sulfate and phosphate.

Animals↗
PubMed1982

Recombination between two IS/s flanking the r-determinant of R100-1: involvement of dor and recA gene functions in Salmonella typhimurium.

Drug resistance genes of the r-determinant component of a composite R plasmid R100-1 were frequently lost in Salmonella typhimurium. Various deletion mutants were analyzed by restriction endonuclease cleavage, Southern blotting, and hybridization techniques. The loss of the r-determinant was found to be the result of a reciprocal recombination between the two IS/s flanking the r-determinant. This recombination depended upon both dor and recA gene functions.

Base Sequence↗
PubMed1982

Cointegrate formation between homologous plasmids in Escherichia coli.

Conjugation experiments were performed in which the donor was Escherichia coli K-12 strain KP245 containing either R plasmid NR1 plus an ampicillin-resistant derivative of ColE1 (*ColE1::Tn3, called RSF2124) or NR1 plus RSF2124 carrying a cloned EcoRI fragment of NR1. The recipient was the polA amber mutant JG112, in which RSF2124 cannot replicate. Ampicillin-resistant transconjugants can arise only when the genes for ampicillin resistance are linked to NR1 or are transposed to the host chromosome. When EcoRI fragment A of NR1 (20.5 kilobases) was cloned to RSF2124, the frequency of cotransfer of ampicillin resistance with tetracycline resistance was 25 to 60%. Plasmid DNA from these ampicillin-resistant transconjugant cells was analyzed by gel electrophoresis and was shown to be a cointegrate of NR1 and the RSF2124 derivative. Analysis of plasmid DNA isolated from donor cultures showed that the cointegrates were present before conjugation, which indicates that the mating does not stimulate cointegrate formation. When the cloned fragment was EcoRI fragment H of NR1 (4.8 kilobases), the frequency of cotransfer of ampicillin resistance with tetracycline resistance was about 4%, and the majority of the ampicillin-resistant transconjugants were found to contain cointegrate plasmids. When the donor contained NR1 and RSF2124, the frequency of cotransfer of ampicillin resistance was less than 0.1%, and analysis of plasmid DNA from the ampicillin-resistant transconjugants showed that Tn3 had been transposed onto NR1. These data suggest that plasmids which share homology may exist in cointegrate form to a high degree within a host cell.

Ampicillin↗
PubMed1982

Influence of hypothyroid status on dopamine-induced positive chronotropic and inotropic effects on isolated rat atria.

The involvement of alpha- and beta-adrenoceptors in dopamine (DA)-induced positive chronotropic and inotropic effects was investigated in isolated atria from euthyroid and hypothyroid rats. Propranolol at 3 x 10(-7) M remarkably inhibited the positive chronotropic effect of DA in both euthyroid and hypothyroid rats, and 1 x 10(-6) M phentolamine inhibited the effects of DA in the presence of propranolol in hypothyroid rats. Propranolol remarkably inhibited the positive inotropic effect of DA in both euthyroid and hypothyroid rats, while phentolamine was effective only in hypothyroid rats. In atria from reserpinized rats, the pD2-values for DA in both chronotropic and inotropic effects were reduced, but effectiveness of propranolol or phentolamine on DA-induced positive chronotropic and inotropic effects in euthyroid and hypothyroid rats was similar to that in non-reserpinized rats. In hypothyroid rats, DA increased the maximal rate of tension development, which was inhibited by both phentolamine and propranolol. DA shortened the duration of contraction. DA in the presence of phentolamine significantly shortened the duration of contraction but did not in the presence of propranolol. In conclusion the DA-induced positive chronotropic effect is mainly produced by beta-adrenoceptor stimulation in both euthyroid and hypothyroid rats, and also by a alpha-adrenoceptors to some extent in hypothyroid rats. The DA-induced positive inotropic effect is produced by alpha- as well as beta-adrenoceptor stimulation in both groups. However, alpha-adrenoceptors were involved to a greater extent in hypothyroid rats than in euthyroid rats. The stimulation of alpha-adrenoceptors by DA causes an increase in the maximal rate of tension development without a significant change in the duration of contraction, and the stimulation of beta-adrenoceptors by DA causes an increase in the maximal rate of tension development and shortening of the duration of contraction.

Animals↗