Search PubMed⌕ Search

Biomedical subjects

K Tanimoto

Publications and source records attributed to K Tanimoto.

At least 289 records · Page 16Linked to original sources

Inhibition by lithium of dopamine receptors in rat prolactin release.

We investigated the effect of lithium on prolactin (PRL) secretion in both urethane-anesthetized rats and right atrial catheter-bearing conscious rats. Basal plasma PRL levels were not significantly altered for 4 h after lithium administration. However, lithium treatment apparently potentiated PRL release by haloperidol in both conscious and urethane-anesthetized rats. In addition, the inhibition by apomorphine of PRL secretion was significantly antagonized by lithium in conscious rats. Lithium had no effect on the enhancement of PRL secretion by either 5-hydroxytryptophan or beta-endorphin in conscious rats. These observations indicate that lithium affects PRL secretion when dopaminergic neural activity is altered. Therefore, it is possible to postulate that the decrease of dopamine receptor sensitivity by lithium may be related to the therapeutic action of the drug on affective disorders.

5-Hydroxytryptophan↗

Natural cell-mediated cytotoxicity in Sjögren's syndrome and rheumatoid arthritis.

Natural cell-mediated cytotoxicity (NCMC) was measured in 7 patients with Sjögren's syndrome without complication of connective tissue disease, 5 patients with Sjögren's syndrome associated with connective tissue disease other than rheumatoid arthritis (RA), 13 patients with Sjögren's associated with RA, and 29 patients with RA without Sjögren's. All 25 patients with Sjögren's syndrome showed a significantly suppressed NCMC. In the patients with RA but without Sjögren's, the NCMC for 21 female patients was rather enhanced when compared with controls, while 8 male patients did not differ from controls. The reduced NCMC in the Sjögren's patients did not seem to correlate with the presence of antilymphocyte antibody. A more accelerated rate of NCMC was demonstrated in the patients with RA who were receiving gold therapy.

Adult↗

Effect of lithium on prolactin responses to thyrotropin releasing hormone in patients with manic state.

The plasma thyrotropin (TSH) and prolactin (PRL) responses to thyrotropin releasing hormone (TRH) were studied before and during lithium treatment for 3-4 weeks in 6 patients with manic states and 8 control subjects. The plasma TSH responses to TRH were not different between the two groups before lithium treatment. Lithium administration did not alter non-stimulated secretion of TSH in any groups, but resulted in exaggerated responses of plasma TSH to TRH in both groups. No difference between two groups was observed in plasma TSH responses to TRH. The basal plasma PRL concentration did not differ between the two groups and was not affected by lithium administration to either group. The plasma PRL responses to TRH in female subjects were greater than those in male subjects. In females, the plasma PRL responses to TRH in manic patients were significantly higher than those in control subjects before the treatment. Lithium administration caused enhanced responses to TRH in patients when compared to pretreatment levels, but not in control subjects. Although the small number of male subjects limits conclusions, pretreatment plasma PRL responses to TRH in male manic patients were apparently greater than those in control subjects. However, lithium administration appeared not to affect the responses of plasma PRL to TRH in manic patients when compared to pretreatment levels. The augmented responses of plasma PRL to TRH in patients with manic states suggest the existence of some abnormality in the hypothalamo-pituitary axis. Thus, the effect of the anti-manic agent on PRL secretion in manic patients may suggest the mechanism by which the drug affects manic symptoms.

Adult↗

Characterization and possible mechanisms of mitogen-induced cell-mediated cytotoxicity.

Mitogen-induced cell-mediated cytotoxicity (MICC) of human peripheral blood granulocytes (PMN) and lymphocytes (PBL) was studied by using chicken erythrocytes as targets. The possible mechanisms were elicited bidirectionally by means of the MICC inhibition test and by functional analysis of lectin. In our preliminary data it was noted that PMN-mediated cytotoxicity was more potent than that of PBL. In addition, erythrophagocytosis or lysosomal enzymes released from PMN offered little contribution to cytotoxic activity of PMN. From the inhibition study it was realized that intact cytoskeletal structures, functionally preserved membrane lectin receptors, active DNA synthesis, and environmental divalent cations were mandatory for the full expression of MICC activity by both effectors. We also identified the cytotoxic activity of PHA-P as having a unique character that is thermostable and independent of the other biological activities.

Animals↗

Family analysis of Werner's syndrome: a survey of 42 Japanese families with a review of the literature.

Forty-two Japanese families, including 80 individuals with Werner's syndrome were studied, confirming that this syndrome is inherited as an autosomal recessive trait. The incidence of malignancy was relatively high in these families and individuals with Werner's syndrome, although the incidence was not so high as was reported previously. HLA typing revealed no significant linkage with Werner's syndrome. The frequency of Werner's syndrome in Japan was estimated using two methods which indicated approximately 300 cases among 100 million people.

Adolescent↗

A simple rapid autoradiography for 3H-thymidine labeling index and its application to therapy of adult acute leukemia.

Our simple rapid autoradiography for 3H-thymidine (3H-TdR) labeling index (LI) of leukemic cells was introduced. Thirty-nine adult patients with acute nonlymphocytic leukemia were treated under a new protocol using 3H-TdR LI as a parameter and inserting a trial of partial synchronization by Ara-C. The success rate of synchronization by Ara-C (rise of the LI up to 10%) was 62.5% out of 32 courses. By our regimen the complete remission (CR) rate of 71.4% in 35 first treated cases, that of 44.0% in 25 courses of recurrent cases, and a median survival of 12 months were achieved. A survey of literature revealed that our results were favorably compared with others. Our new protocol is advantageous in permitting one to precisely know the proper time for chemotherapy and thus avoiding unnecessary side effects.

Acute Disease↗

Natural cell mediated cytotoxicity in systemic lupus erythematosus: suppression by antilymphocyte antibody.

The significantly reduced natural killer (NK) cell activity was demonstrated in the peripheral blood lymphocytes (PBL) from 20 female patients with systemic lupus erythematosus (SLE) when compared with NK activity in the age- and sex-matched controls. The reduced NK activity did not correlate with clinical parameters including daily prednisolone doses, serum CH50, antinuclear antibody titers, and antiDNA activities, circulating immune complex levels, and cytotoxic activities of antilymphocyte antibodies (ALA). The effects of prednisolone and aggregated human IgG on NK activity were only slightly suppressive in the in vitro studies. When normal PBL were pretreated with rabbit complement and SLE sera containing ALA, the NK activity of the surviving cells was markedly decreased. The decrease was specific and did not seem to be due to the physical hindrance of the dead cells. Other heterologous ALA of rabbit origin did not exert a suppressive effect on NK activity. These results suggest that the suppressed NK activity in SLE can be ascribed to an antiNK cell specific antibody in lupus sera, although the participation of circulating immune complexes was not completely excluded.

Adult↗

Met-form hemoglobins in long-term stored ACD blood.

On passing ACD blood stored for a year at 4 degrees C through a column of Sephadex G-75, the surviving erythrocytes were separated from hemolyzed cells and plasma. About 18% of stored erythrocytes survived a year of storage, and were spherocytic. The concentration of total ferric hemoglobins in the surviving erythrocytes was about 75% of that in the supernatant. The met-form hemoglobins in the erythrocytes and hemolytic solutions were further analyzed by isoelectric focusing electrophoresis, and (alpha 2+ beta 3+)2 and (alpha 3+ beta 2+)2 valency hybrids were found in addition to methemoglobin. Since the activity of NADH cytochrome b5 reductase was extremely low in the surviving erkythrocytes, the difference in proportion of ferric hemoglobins (valency hjybrids + methemoglobin) in these two fractions might be due simply to the difference in pH between intracellular and extracellular fluids, which is largely reflected in the oxidation rate of hemoglobin. The course of hemoglobin oxidation seems to be through hemoglobins such as (alpha 2+ beta 3+)2 and (alpha 3+ beta 2+)2 to methemoglobin.

Blood Specimen Collection↗