Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

293 records · Page 17Linked to original sources

PubMedDate not supplied

Modified ovoid applicator for intracavitary radiation therapy with a Selectron-MDR or microSelectron-HDR.

A modified ovoid applicator for intracavitary radiotherapy was developed for Japanese and other Asian women. It has more variations of smaller sized ovoids than the original rigid standard applicator of the Selectron-MDR and microSelectron-HDR. In addition, application of the ovoid pair and tandem flange is easy due to the flat surface of the inner aspect of the ovoid pairs, which prevents slippage of the ovoids and flange. The applicator is described together with source loading and dose distribution.

Asia↗

PubMedDate not supplied

Pharmacokinetic analysis of enterohepatic circulation of buprenorphine and its active metabolite, norbuprenorphine, in rats.

The pharmacokinetic characteristics of buprenorphine (BN) and its active metabolite, norbuprenorphine (NBN), was investigated using rats. The elimination half-life (t1/2), total body clearance (CLtot), and steady-state volume of distribution (Vdss) of BN (0.6 mg/kg iv dose) in the intact rat were 2.8 hr, 23.3 ml/min/kg, and 4.2 liters/kg, respectively, and those of NBN (0.6 mg/kg iv dose) were 0.9 hr, 35.0 ml/min/kg, and 2.0 liters/kg. Within 24 hr after administration of BN (0.6 mg/kg dose) to the bile-fistula rat, 74.1% of dose was excreted in the bile as BN glucuronide (BN-Glu) and 18.5% as NBN glucuronide (NBN-Glu), and in urine < 3.2% as BN-Glu. After administration of NBN to the bile-fistula rat, 85.1% and 9.1% of the dose were excreted as NGN-Glu in bile and urine, respectively. The existence of the enterohepatic circulation (EHC) of BN and NBN was confirmed by using paired rats: the donor and recipient rats. Within 24 hr after administration of BN (0.6 mg/kg dose) to the donor rat, 58.8% of the dose was reexcreted as NBN-Glu in bile of the recipient and 25.1% as BN-Glu. Based on the results of in vitro metabolism, it was suggested that this increase in the proportion of NBN-Glu in bile observed after one enterohepatic cycling of BN may be due to the first-pass metabolism in the liver. BN was detected in the plasma of the recipient rat after administration of BN, to the donor rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

High-dose rate intracavitary therapy for cervical cancer with a microSelectron: a preliminary report.

Our early experience using microSelectron HDR to treat cervical cancer patients at Osaka University Hospital is presented. From June 1991 through December 1992, a total of 20 patients (stage Ib, 6; stage IIa, 2; stage IIb, 5; stage IIIb, 6 and stage IVa, 1) with previously untreated invasive uterine cervical cancer and intact uterus were treated with high-dose rate intracavitary therapy administered with a microSelectron. For the treatment, a standard rigid applicator made of stainless steel for a microSelectron was used. Twenty to 30 Gy of external irradiation was administered to the whole pelvic field and 30 to 20 Gy to the central shielded field (total 50 Gy/5-6 weeks) for patients in stage II-IVa. For stage Ib, 40 Gy was delivered to the central shielded field. The 192Ir source had an activity of 370 GBq as of the measuring time. Source loading corresponded to the Manchester System for cervical cancer. Thirty-two or 30 Gy was administered at point A in four fractions over four weeks of intracavitary irradiation. Early primary tumor responses for all patients were complete. There have been two local recurrences in stage IIb and IIIb patients. Three patients in stages Ib, IIb, and IIIb developed para-aortic lymph node metastases, and two of them died from generalized metastasis. No acute radiation injury has been observed. One patient in stage IIb developed subileus five months after irradiation. From our early experience, it is concluded that microSelectron HDR can be used for cervical cancer patients as safely and effectively as our previously used high-dose rate machine.

Brachytherapy↗

PubMedDate not supplied

Mid-dose rate intracavitary therapy for cervical cancer with a Selectron: a preliminary report.

Our early experience with Selectron MDR in treating cervical cancer patients at Osaka University Hospital is presented. From May 1991 through December 1992, a total of 22 patients (stage Ia, 1; stage Ib, 3; stage IIa, 1; stage IIb, 2; stage IIIb, 13 and stage IVa, 2) with previously untreated uterine cervical cancer and intact uterus were treated with mid-dose rate intracavitary therapy administered with a Selectron. A rigid applicator made of stainless steel for the Selectron was used for the treatment. The 137Cs source had an activity of 1.48 GBq as of reference time. Source loading corresponded to the Manchester System. Early tumor responses for all patients were complete. No acute radiation injury has been observed. There have been two local recurrences in stage IIIb patients. One of them developed para-aortic lymph node metastasis and died from distant metastasis. Another patient in stage IIIb had para-aortic and left supraclavicular lymph node metastasis and died from distant metastasis. Four patients developed rectal bleeding (grade 1, 3; grade 3, 1). One of them had been treated for aplastic anemia with steroid. The cause of grade 3 rectal bleeding was considered to be technical failure in intracavitary application. The remaining two patients recovered without treatment. From our early experience, it is concluded that Selectron MDR can be used for cervical cancer patients as safely and effectively as our previously used high-dose rate machine.

Brachytherapy↗

PubMedDate not supplied

Symptomatic relief for patients with osseous metastasis treated with radiation and methylprednisolone: a prospective randomized study.

A multi-institutional prospective study to evaluate the relief of symptoms for patients with osseous metastasis treated with irradiation and methylpredonisolone was performed. A total of 38 patients with osseous metastasis, treated between January 1991 and December 1992, were included in this study. Patients were randomly allocated to one of two treatments: radiation alone (RT alone) (n = 18) or radiation combined with methylpredonisolone (RT + MP) (n = 20). Symptoms were scored by patients themselves using original Quality of Life (QOL) scores. Stratification by urinary hydroxyproline/creatinine ratios (Hypro/Cr) showed no significant differences in QOL scores between RT and RT + MP in the group with good prognosis, which showed a lower Hypro/Cr (< 3.6 mg/g) during treatment. Following treatment, the score for both groups improved. On the other hand, in the group with poor prognosis, with a higher Hypro/Cr (> or = 3.6 mg/g), a significantly greater improvement in QOL scores was observed for the RT + MP group than for the RT alone group (p < 0.05). There was also a marked difference in the RTOG pain scores, evaluated by physicians before treatment and at the end of treatment, between the two treatment groups and the prognostic groups divided according to Hypro/Cr. No correlation was seen at initial presentation between urinary Hypro/Cr and serum tartrate-resistant acid phosphatase (TrACP). In conclusion, the treatment regimen of RT + MP is recommended for patients with osseous metastasis with poor prognosis who show relatively high Hypro/Cr values. Radiotherapy was equally effective in terms of RTOG pain score for both the poor and good prognostic groups. Serum TrACP was not useful for determining the prognosis of our patient groups.

Adult↗