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Biomedical subjects

R Okamoto

Publications and source records attributed to R Okamoto.

314 records · Page 18Linked to original sources

Effects of a Chinese herbal medicine, keishi-bukuryo-gan, on the gonadal system of rats.

Keishi-bukuryo-gan (TJ-25) is a traditional Chinese herbal remedy containing five components: bark of Cinnamomum cassia, root of Paeonia lactiflora, seed of Prunus persica or P. persiba var. davidiana, carpophores of Poria cocos and root bark of Paeonia suffruticosa. This preparation has been used in the treatment of gynecological disorders such as hypermenorrhea, dysmenorrhea and infertility. In the present study, the effects of TJ-25 on plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E2), and on uterine wet weight and thymidine kinase (TK) activity were documented in immature rats. Long-term daily oral administration of TJ-25 (300 mg/kg) for 14 days decreased plasma levels of LH, FSH and E2 by 94%, 67% and 50%, respectively, compared to controls. Uterine wet weight and TK activity were reduced to 65% and 64% that of controls, respectively. Short-term effects of TJ-25 on E2 were also examined. Thirty hours after administration of E2 (1.0 micrograms/kg) alone, uterine wet weight and TK activity were elevated 2.4- and 21-fold, respectively, over controls. However, simultaneous administration of TJ-25 (three consecutive doses, every 12 h) with E2 reduced E2-induced increases in uterine wet weight and TK activity by 29% and 39%, respectively. Treatment with TJ-25 also enhanced LH-RH-induced increases in plasma LH and FSH levels 1.2- and 2.5-fold, respectively, as compared with controls. The results obtained in the present study indicate that TJ-25 may act as a LH-RH antagonist and/or as a weak anti-estrogen.

Administration, Oral↗

Detection of doxorubicin cardiotoxicity by using iodine-123 BMIPP early dynamic SPECT: quantitative evaluation of early abnormality of fatty acid metabolism with the Rutland method.

BACKGROUND: To evaluate the possibility of predicting the development of doxorubicin-induced cardiomyopathy, we performed quantitative assessment of the early kinetics of iodine-123 beta-methyl-iodophenyl-pentadecanoic acid (I-123 BMIPP) by means of dynamic myocardial SPECT. METHODS: Thirty-six patients with various malignancies were examined. I-123 BMIPP dynamic myocardial SPECT was performed before chemotherapy, after chemotherapy, or both. Immediately after the injection of I-123 BMIPP (111 MBq), 30-second dynamic SPECT data were acquired successively for 15 minutes. The left ventricular (LV) myocardium was divided into 8 segments in short-axial and vertical slices. By using the time-activity curve (TAC) of each myocardial segment [Mo(t)] as an output function and the TAC of the LV cavity [B(t)] as an input function, the Rutland equation, Mo(t)/B(t)= F + K Integral of(B(t)dt/B(t)), was used as a means of assessing all segments. RESULTS: Mo(t)/B(t) showed a good linear correlation with Integral of(B(t)dt/B(t)) from 30 seconds to 4 minutes in all 456 segments. The mean K value of 8 LV segments was significantly lower after chemotherapy than before chemotherapy (0.071+/-0.019 [n = 21] vs. 0.095+/-0.025 [n = 36], P<.001). In 21 patients in whom dynamic SPECT was performed both before and after chemotherapy, the mean K values of left ventricle showed a significant decrease, from 0.101+/-0.024 to 0.071 +/-0.019 (P<.0001). The fractional change in the value of K after chemotherapy showed a significant linear correlation with the administered dose of doxorubicin (r = 0.648, P<.002). CONCLUSION: I-123 BMIPP dynamic myocardial SPECT may be clinically useful, because it permits the early detection of doxorubicin-induced cardiomyopathy.

Adult↗

Extramedullary plasmacytoma of the sinonasal cavities: CT evaluation.

Computed tomography was performed in four patients with solitary extramedullary plasmacytoma of the nasal cavity and paranasal sinuses. Two tumors originated in the nasal cavity, one in the maxillary sinus, and one in the frontal sinus. Soft tissue mass(es) was seen in all patients. Bone destruction was apparent in only two patients. It seems possible to rule out carcinomas in such patients with no or subtle bony destruction. Computed tomography was also helpful for planning radiation therapy.

Adult↗