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H Maezawa

Publications and source records attributed to H Maezawa.

At least 73 records · Page 4Linked to original sources
PubMed1989

[The evaluation of simple estimation method of prostate size by transabdominal ultrasound].

We evaluated 107 patients who were diagnosed as benign prostatic hypertrophy preoperatively and underwent transurethral resection of the prostate. We obtained the maximum cross section of the adenoma by transabdominal scanning using a real-time large-sized convex scanner and a 3.5 MNz. transducer. Regarding the adenoma as an ellipsoid with revolution around its transverse axis, 2 diameters (breadth and height) were measured with transverse scan (a and b, respectively). We then calculated the values of the estimated size of the adenoma according to the formula for a spheroid. V = (pi/6) ab2. Thus the calculated weight were correlated with the resected weight of the specimen after a complete transurethral resection of the prostate. As a result, the sonographic estimation provided a high correlation coefficient: r = 0.956. The result suggested that our method of transabdominal ultrasonography in the preoperative evaluation of the prostatic size was rapid, simple and noninvasive, was well adapted for screening sufferers from prostatic diseases, and gave preoperative information for transurethral resection of the prostate and other surgical operation.

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PubMed1988

Effects of monoenergetic X-rays with resonance energy of bromine K-absorption edge on bromouracil-labelled E. coli cells.

In order to examine enhanced killing that might be induced by Auger cascades in the incorporated atoms in cells, bromouracil(BrU)-labelled E. coli cells were irradiated with monoenergetic X-rays at 13.49 and 12.40keV, just above and below the K-absorption edge of bromine. In both cases BrU-labelled cells were more sensitive for killing than were normal cells. However, when the degree of BrU-sensitization was compared between the two energies of X-rays, the enhanced killing at 13.49 keV was only small, 2 +/- 8 per cent based on the D0 value in saline. By the addition of DMSO, which is believed to suppress radical-mediated effects, killing of BrU-labelled cells was enhanced at 13.49 keV by 8 +/- 4 per cent as compared with 12.40 keV, based on D0. These results have been examined in terms of absorbed energy in BrU-labelled cells and in terms of the number of induced Auger events.

Bromouracil↗
PubMed1987

2-Arylidene-4-cyclopentene-1,3-diones designed as non-nitro radiosensitizers and hypoxic cytotoxins.

The radiosensitizing effects and hypoxic cytotoxicity of 2-(4'-hydroxybenzylidene)-cyclopentene-1,3-dione (KIH-200) and its 3'-methoxy and 3',5'-dimethoxy derivatives (KIH-201 and KIH-202) were investigated in vitro. These synthetic compounds were newly designed as non-nitro electron-affinic radiosensitizers and hypoxic cytotoxins on the basis of their high electron affinities and electrostatic potentials which were estimated by semiempirical molecular orbital calculation using the CNDO/2 program. The compounds were shown to have weak but apparent hypoxic cytotoxicity to FM3A cells from C3H mice. On irradiation in the presence of KIH-201 or KIH-202, hypoxic cells were more sensitive than aerobic cells at very low drug concentrations (below 10 microM), whereas KIH-200 was less effective.

Animals↗
PubMed1987

Relationship between primary tumor volume and lung metastasis in Lewis lung carcinoma (1). Assay for time course of development of metastasis.

Relationship between primary tumor volume and development of lung metastases was investigated in Lewis lung carcinoma in male C57BL/6 mice. Tumor cells (1-3 X 10(5] were injected into the muscle of the right hind legs and growth curves of primary tumors were obtained. The time course of development of metastases was determined from the size of lung colonies at autopsy by using growth rate of lung colonies. The first development of metastasis was 4 to 7 days after injection. The incidence of metastases increased as a function of time and was presented by Gompertz function as in primary tumor volume. Therefore, a linear relationship was found to exist between the incidence of metastases and the primary tumor volume. This assay is considered to be useful to understand the time course of development of metastases without resection of the primary tumors.

Animals↗
PubMed1987

Relationship between primary tumor volume and lung metastasis in Lewis lung carcinoma (II). Tumor bed effect.

The incidence of lung metastases from tumors which had the tumor bed effect (TBE) was investigated in Lewis lung carcinoma in male C57BL/6 mice. Tumor cells (1-3 x 10(5] were injected into the muscle of the right hind legs which had been locally irradiated with 15 Gy of gamma rays 1 hr or 1, 4, 7, 10, or 14 days previously. The latent periods for tumor appearance were almost the same as in the controls. Compared to the controls, growth delays were observed from about 7 days after tumor cell injection. For metastasis from tumors which had the TBE, although the first development of metastasis was not different from the controls, the total number of metastases was reduced. The incidence of metastases varied according to growth of the primary tumor. The correlation between the primary tumor volume and the incidence of metastases also showed a linear relation, as in the controls. These results indicate that metastasis from tumors growing in pre-irradiated sites depended on the TBE of the primary tumors.

Animals↗
PubMed1987

Local control rate of split-course irradiation combined with chemotherapy for head and neck cancer.

Between 1976 and 1984, 99 patients were treated with radical external irradiation (RT) for squamous cell carcinoma of the head and neck excluding the glottis and paranasal cavity. Twenty-six out of 55 patients (47%) on chemotherapy (CT) were treated by split-course (split) RT, mainly because of acute mucositis. Only 8 out of 44 patients (18%) not on CT were treated by split RT. Although the group given split RT alone rested for 14 days and received 35 Gy, the split RT + CT group rested for 16 days and received a lower dose (30.5 Gy). The mean total doses for each treatment modality were 64 Gy in the continuous course (contin.) of RT alone, 63 Gy in contin. RT + CT, 67 Gy in split RT, and 62 Gy in split RT + CT. The observed/predicted (by a Radiation Therapy Oncology Group) control ratios of primary lesions at 2 yrs were 61/80 (0.76), 72/83 (0.87), 75/73 (1.03), and 69/71 (0.97), respectively. Among patients with a predicted rate of over 80%, the observed rates were almost identical (72%, 74%, 4/4, and 75%, respectively). However, for patients with predicted rates of 50-80%, the observed rate was 71% (12/17) in the group given combined therapy against 50% (5/10) in RT alone group. Among patients with predicted rates under 50%, the observed rate was 57% (4/7) in split RT + CR and only 25% (1/4) in contin. RT; there were no cases in contin. RT + CT. Split RT + CT is considered to be favorable for patients with poor prognostic factors.

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